*2.4. The Parallel Mediation Model*

A parallel mediation model was used in the study to verify our assumptions. It is a basic mediation model (4) from Hayes PROCESS templates [33]. Our theoretical model (Figure 1) assumes that perceived control over time (X) would indirectly affect fear of COVID-19 (Y) through two mediators: mental health (m1) and vitality (m2). All the individual direct and indirect paths as the total indirect effect were calculated as described in Figure 1.

**Figure 1.** Hypothesized model.


**3.1 Medical applications**

The use of thin films for medical applications arises from the fact that most bulk biomaterials that are currently used as invasive devices were not developed for this specific purpose. In fact, most bulk materials used as biomaterials can be found in our garages because they were developed for different purposes. Examples are light titanium alloys used in cars parts or carbon reinforced composites in bicycles. The experience has proven that the body more or less tolerates these materials and their overall set of properties/characteristics (mechanical, electrical, etc.) is appropriated for a specific use inside the body. However, in the majority of the cases the surface is not optimized for biological environment and, no matter how good and appropriate the bulk material is, if the surface does not present the adequate combination of chemical composition, wettability, surface charge and morphology/topography, the abiotic/biotic interface is never going to reach its full potential. Consequently, the bulk material is often modified by the deposition of a thin film.

The first example of the use of thin films for medical applications concerns work developed in our laboratories, never published before. This study arose from the fact that in most of the recently published literatures concerning the use of Ti6Al4V alloy for medical invasive devices in contact with hard tissue, such as for orthopedic and orthodontic applications, refer the need to substitute vanadium (V) by another element. This fact, from the biochemical point of view, has no sustainability. In fact, V is a key element in some of the metabolic pathways of our organism and is being considered in some pharmaceutical drugs, due to its antidiabetic effect [17]. Moreover, there are no metabolic pathways that use titanium (Ti) or aluminum (Al) and these elements are present in much higher contents than V. Therefore, our study had the goal to access the difference between an unmodified bulk Ti6Al4V femur implant and the sputter modified implant. For the surface modification, two chemical compositions were produced: Ti6Al4V and Ti6Al. With this approach, it would be possible to study the effect of vanadium in the Ti-based thin film and also compare the same chemical composition (Ti6Al4V) in bulk and thin film form.

Both thin films presented a thickness of 750 nm, and from the X-ray diffractograms, it was possible to calculate the crystallite size of the thin films: 17.5 and 20 nm for Ti6Al and Ti6Al4V, respectively. This indicated that, in opposition to the microscopic grain size of the bulk material, the thin films were nanostructured. The hardness of both bulk and thin films was determined by ultra-micro hardness test and, due to the nanometric crystallite size, the hardness of the thin films was higher than the bulk material (**Table 1**). This was expected according to Hall-Petch relation [18]. Nevertheless, the presence of vanadium in the thin film reduced the hardness value in comparison with the Ti6Al thin film.

#### **Table 1.**

*Hardness and adhesion of the bulk and thin films Ti-alloys.*

Another important characterization was the evaluation of the adhesion of the thin films to the Ti6Al4V bulk substrate. In fact, the presence of an interface between the substrate and the thin film is often related with the development of stress that result in the detachment of the thin film when in use. The characterization was performed by a scratch indentation test and the results (**Table 1**) allow to determine both cohesive (Lc1) and adhesive failures (Lc2) values. Due to the perfect chemical compatibility between the Ti6Al4V thin film and bulk material, both cohesive and adhesive failures are higher than 70 N (the maximum value determined by the equipment). For the Ti6Al thin film, despite the similar chemical composition, the adhesive failure (detachment of the thin film from the substrate) occurred at 44 N.

The wettability was accessed by static contact angle measurements between 10 μL of water and the three surfaces (**Figure 1**).

The results showed that the bulk material presented the highest contact angle (78°), followed by Ti6Al thin film (62°) and finally Ti6Al4V thin film which presented a zero-contact angle revealing a completely wettable surface. This fact indicates that the ion exchange between the Ti6Al4V thin film and the biological fluid is enhanced, indicating that the formation of an apatite-like layer on this surface will be easier to occur than on the other two materials and, therefore, a better osseoinductive behavior is expected from Ti6Al4V thin film.

In fact, when the unmodified and sputter modified bulk Ti6Al4V were immersed for 60 days in Hanks' simulated body fluid, at 37°C with 100 rpm, the previous expectations were confirmed (**Figure 2**). The analysis of chemical distribution of calcium on the surface of the materials (**Figure 2**) unequivocally showed a higher surface coverage on the surface of the Ti6Al4V thin film.

Therefore, the surface of this specific thin film demonstrated, by the *in vitro* tests, to be the most promising for the osseointegration of medical invasive devices that contact with hard tissue. The presence of V in the thin film seems to be essential for the better performance of the Ti alloy, when in comparison with the Ti6Al thin film. Also, due to its nanostructured structure, Ti6Al4V thin films outperform the chemical mimetic bulk material.

The second example of applications of thin films for medical applications is also based on work developed in our laboratory and never published before and is

#### **Figure 1.**

*Contact angle between a drop of water and Ti6Al4V bulk material (a), Ti6Al thin film (b) and Ti6Al4V thin film (c).*

*Thin Films for Medical and Environmental Applications DOI: http://dx.doi.org/10.5772/intechopen.80021*

#### **Figure 2.**

*Elemental map distribution of calcium (light blue) on the surface of the modified and unmodified bulk Ti6Al4V bulk implant after 6 and 60 days of immersion in Hanks' solution (bar = 80 μm).*

related with neural implants. Some examples of the use of materials in neurosciences include the monitoring of intracranial pressure, the regeneration of nervous tissue of the medulla region, for controlled drug delivery systems and microelectrodes for the nervous system. In the latter case, the devices may be used to increase or decrease a certain neurological function. Focusing of this type of application, one of the major problems in this field of Biomedicine is the lack of mechanical and biological compatibility between the tissue and the materials used as implants: silicon, tungsten, gold, iridium and stainless steel. In fact, although tests carried out in accordance with ISO 10993 have demonstrated the noncytotoxicity of the abovementioned materials, the results of *in vitro* and *in vivo* experiments show a very different reality. The development of a glia scar around the nervous tissue inhibits, after few weeks, the stimulation and recording of neurons. Several examples are present in the literature of research addressing this problem by modifying the surface of neural electrodes by different strategies [19–22], but mostly with polymeric materials.

Our work addressed this issue by modifying silicon neural implants by sputter depositing hybrid nanostructured thin films of silica, gold and silver (SiO2/Ag/Au) [23]. SiO2 was chosen due to its chemical compatibility with the base material thus preventing the lack of adhesion between substrate and thin film. The nanocomposite system was designed to induce the release of one metal, which has been described as having antimicrobial properties, silver. In order to ensure that silver was oxidized, gold was added.

Several chemical compositions were tested and characterized in order to select the best one for the in vitro tests with prokaryotic and eukaryotic cells. If was confirmed, by transmission electron microscopy (TEM) characterization, the nanocomposite nature of the hybrid deposited thin films (**Figure 3**). They all consisted of an amorphous silica layer with dispersed nanometric size metal grains.

All the films presented a mean surface roughness, determined by atomic force microscopy, lower than 20 nm and hardness values, determined by nanoindentation, of around 2 GPa. The thin film with the chemical composition (in atomic %) of Si = 25.8; O = 53.4; Ag = 9.6 and Au = 11.2, was chosen for the remaining characterizations and the biological tests. This surface presents a static contact angle with water of 26° and a zeta potential value of −70 ± 4 mV.

The first in vitro tests were made with *Pseudomonas aeruginosa* bacteria in order to test the antimicrobial activity of the developed hybrid nanostructured tin film. After 24 h of incubation, the halo inhibition test (**Figure 4**) demonstrated that neither silicon (result not shown), nor SiO2 presented any antimicrobial effect. On the contrary, the SiO2/Ag/Au thin film presented a 4 mm inhibition halo indicating that the Si modified surface was able to inhibit the growth of these strain of bacteria, which is considered one of the most harmful in nosocomial related infections.

The tests with rat embryo cortex cells, within the conditions usually used for this type of tests in neurosciences, and after 15 days of incubation, the cells were prepared for the immunocytochemistry tests. The observation in an optical fluorescent microscope (**Figure 5**), where the neurons nuclei are marked in blue, showed that unmodified silicon presents a very poor cell density, while SiO2/Ag/Au presented

#### **Figure 4.**

*Optical micrographs of the inhibition growth halo tests, with P. aeruginosa, of silicon modified with SiO2 (a) and SiO2/Ag/Au (b) thin films (bar = 10 mm).*

*Thin Films for Medical and Environmental Applications DOI: http://dx.doi.org/10.5772/intechopen.80021*

#### **Figure 5.**

*Optical fluorescent micrographs of rat embryo cortex cells after 14 days of incubation with polylysine (a), silicon (b) and SiO2/Ag/Au (c) surfaces (bar=200 μm).*

a higher cell density, almost similar do the one observed on the "gold standard" of these type of tests, polylysine.

### **3.2 Environmental applications**

Environmental degradation is a very challenging field. Natural resources are being enormously harnessed and their stock is exhausted every day. Moreover, the ecological balance is disturbed and the natural resources are being polluted.

For the removal of contaminants from the environment, several strategies are available. In the past, classic remediation strategies were mainly used. An example of innovation for sustainable development is to use alternative remediation strategies as bioremediation. Although the Romans already used organisms to clean their wastewater in 600 BC, it was only after 1972 that the first official bioremediation strategies were tested.

Microbial responses to metals with potential for bioremediation include chelation, compartmentalization, exclusion and immobilization [24]. The use of these bacterial abilities is an important strategy for the development of the bioremediation tools. Often, their application to the environment requires the immobilization of the cells to obtain an effective bioremediation. Bacterial cells can be immobilized in different supports. Briefly, cells can be immobilized by covalent coupling, affinity immobilization, adsorption, confinement in liquid-liquid emulsion, capture in a semipermeable membrane and entrapment in polymers [25].

When genetically modified organisms are used, their covalent immobilization is mandatory in order to prevent their release into the environment. However, the covalent immobilization of the cells always requires that the biological entities keep their metabolic abilities, useful for bioremediation. Moreover, immobilization of microorganisms presents several major advantages such as: (1) continuous supply of nutrients without competition with other microorganisms [26]; (2) increase of biomass of specialized microorganisms with specific desired metabolic activity [27, 28]; (3) protection of the cells against the environmental stress, toxic chemicals and UV irradiation [27, 29]; (4) easier control of the bioprocess [29] and (5) easy, cheap and feasible technique to be used since the immobilized microorganisms can be used several times without significant loss of activity [30].

The use of thin films in the design of biotools for environmental application is here illustrated by two case studies. The first describes the development of an arsenic biofilter [31]. The environmental contamination with arsenic is a worldwide problem, and the development of new strategies for arsenic removal is an ever ongoing research. In this study, genetically modified bacteria able to accumulate arsenic were generated by modification of the arsenic resistant strain *Ochrobactrum tritici* SCII24T [32]. The *O. tritici* As5 mutant cells, exhibiting a high percentage of arsenite accumulation, were immobilized on a commercial polyethylene (PE) net after sputtered

#### **Figure 6.**

*SEM micrographs of immobilized cells of O. tritici mutant As5 onto PTFE thin films showing an early stage after inoculation (a) and the development of the biofilm (b).*

modified by the deposition of poly(tetrafluoroethylene) (PTFE) thin films, with approximately 500 nm thick. Different PTFE thin films were tested regarding their ability to immobilize cells in an active form that enabled the microorganisms to form a biofilm and work as a biofilter for arsenic. The surface that exhibited a mild zeta potential value, hydrophobic characteristics, the lowest surface free energy but with a high polar component and the appropriate ratio of chemical reactive groups showed to be the optimal for bacteria development (**Figure 6**). The immobilized cells maintained their ability to accumulate the surrounding arsenite.

The second case study describes the application of thin films for bacterial cells immobilization in the construction of a biofilter for the removal of uranium from contaminated water. The biofilter was constructed by the immobilization of the strain *Rhodanobacter* A261 onto the PTFE thin films. Under batch conditions, low nutrient content, pH 5 and different uranium concentrations, this strain was able to remove approximately 120 μM of U(VI) when grown aerobically in the presence of 500 μM U (**Figure 7**). As described earlier, the strain was inoculated in PTFE thin films deposited with different deposition parameters, which led to surfaces with distinct values of zeta potential, hydrophobic characteristics, surface free energy, polar component and ratio of chemical reactive groups.

After being evaluated for their ability to immobilize uranium, the optimized PTFE thin film was used to modify PE commercial nets and, after bacterial cells immobilization, the filters were applied in a wastewater treatment plant from a uranium closed mine (Urgeiriça, Portugal). The filters were submerged during 3 months in the last tank of the wastewater treatment station. After 1 and 3 months, they were removed, and their ability to be colonized (biomass in the filter) and uranium detection (**Figure 8**) was evaluated.

#### **Figure 7.**

*The backscattered mode SEM micrograph (a) showed the presence of U (brighter spots) and the qualitative energy dispersive spectroscopy (EDS) (b) confirmed uranium detection in PTFE thin film of Rhodanobacter A2-61 microcolonies after being in contact with a 500 μM uranium solution.*

*Thin Films for Medical and Environmental Applications DOI: http://dx.doi.org/10.5772/intechopen.80021*

#### **Figure 8.**

*SEM micrographs of noninoculated (a) and inoculated (b) PTFE thin films with Rhodanobacter A2-61 after 3 months submerged in a mine wastewater passive treatment plant; EDS analysis (c) inoculated surface of the region marked with blue arrow in (b).*

The thin films demonstrated its ability to immobilize the cells and stabilize a thick biofilm which was able to be metabolic active in the remediation of metals. Although after 3 months all filters showed microbial colonization, from native species, a difference in thickness and structure was visible between inoculated and noninoculated biofilters. The presence of the thin film showed to be essential for the immobilization of *Rhodanobacter* A2-61 that, in turn, was mandatory for U accumulation. In fact, only these biofilters showed U immobilization. Besides the uranium, other metals were detected in the biofilm, such as Mn and Fe.

### **4. Conclusions**

In this chapter, the production of thin films by sputtering and their uses in medical and environmental fields were exemplified. The ability of the sputtering technique to produce metastable materials, which are not predicted by the traditional chemistry thermodynamic, allows to produce tailor-made surfaces that present the optimized set of properties for specific applications.

A nanostructured Ti6Al4V thin film showed to have better osseointegration properties than in its bulk form. Also, the presence of vanadium proved to be essential to achieve the best performance.

The modification of silicon, used as neural implant, with a hybrid nanocomposite thin film of SiO2/Au/Ag demonstrated to induce a surface that provides a better adhesion and proliferation of rat embryo cortex cells concomitantly with an antibacterial effect against some of the bacteria responsible for nosocomial infections.

The deposition of PTFE thin films, with optimized surface properties, onto the surface of a commercial PE net allowed to develop biotools for the bioremediation of two elements considered very hazardous both for humans and environment: arsenic and uranium.


**Author details**

**7. Concluding remarks**

14 Organizational Conflict

work before a conflict is likely to arise.

flicts arise in the various ways described above.

social conflict, then they have not really communicated well.

The five-step model I have presented in this chapter can be understood as a resource in managers' conflict resolution practices, to be used individually or in dialog with discussion partners, like other managers in management teams. It is a tool for analyzing conflicts to gain a deeper and more systematic understanding of the situation in question so that it becomes clearer how it can be resolved step by step. The model can be used to understand complex conflicts between employees, or between employees and managers, so that the initial understanding of a conflict is transformed into knowledge of the underlying deep structure. The model can also be used in debriefing after a conflict, to understand why the conflict escalated, so that managers are better prepared to resolve a similar escalating situation the next time it occurs. The principles in the model can, additionally, be used to analyze situations in which conflicts have not arisen even though there is a risk that they will arise, typically in processes of reorganization. Furthermore, if managers have knowledge of the characteristics of conflict types, they are better prepared to resolve destructive conflicts not only between persons they are

managers for but also in their own relations to other people in their organization.

Obviously, the degree to which it is possible for managers to use the resolution model comprehensively will depend on contextual matters. Practical limitations can make it impossible for managers to pursue extensive analyses of conflict situations, but it would be wrong to think that the model is irrelevant in such situations. It does not take much time to explore the six questions above in reactive analysis of a given conflict, during a conflict or in preventive

The resolution model is generally applicable to conflict situations, but it is particularly useful for dealing with social interaction in organizations. The complexity of the model corresponds to the complexity of organizations in which people come together from a variety of perspectives, with different beliefs, values and interests [36, 49]. These differences influence how con-

Theoretically, the aim of overcoming the diversity of perspectives and reaching agreement in organizational work is often associated with the philosopher Gadamer and his idea of a fusion of horizons [49]. For Gadamer, agreement and absence of conflict are connected to successful communication: it is impossible to separate the issue of how we understand each other from how we agree and cooperate. According to Gadamer, this implies that if people are in a

Gadamer's philosophy has been developed outside an organizational context, but it is widely recognized that it is eminently applicable to organization theory. The heterogeneous nature of many organizations makes it challenging to achieve a shared understanding and a shared sense of commitment. It has been extensively documented that knowledge gaps and lack of contact between various organizational levels can lead to destructive conflicts directly through lack of teamwork and indirectly through lack of psychological effect such Halvor Nordby1,2\*

\*Address all correspondence to<EMAIL_ADDRESS>
1 Department of Social Work, Faculty of Health and Social Work, Inland Norway University of Applied Sciences, Norway

2 Faculty of Medicine, Institute of Health and Society, The University of Oslo, Oslo, Norway


*4.1. Chemicals*

5,5'-Dithiobis-(2-nitrobenzoic acid) (DTNB), 1,1,3,3-tetraethoxypropane, purified bovine blood SOD, NADH, glutathione (GSH), glutathione disulfide (GSSG), nicotinamide adenine dinucleotide phosphate (β-NADPH, type 1, tetrasodium salt), and glutathione reductase (GR; Type II from Baker's Yeast), were from Sigma Chemicals Co, St. Louis (USA). All other chemicals were from Merck (Darmstadt, Germany) and of the highest grade available.


**1. Introduction**

Light is, at least to me, mysterious—because on one level, it really defines our reality. It's maybe the most defining characteristic of our reality. Everything we see, how we perceive reality, is based on light bouncing o ff of objects, or bending around objects, or di ffracting around objects, and then being sensed by our eyes, and then sending signals into our brain that create models of the world we see around us. So it really is, almost, the defining characteristic of our reality.  And to a large degree it is not fully understood yet.

> —Excerpt from Sal Khan at Khan Academy

#### *1.1. What Is a Hologram?*

The Grecian etymological root for hologram is 'whole message' or 'whole writing'. Every point-perspective within the hologram contains the entirety of the light information generated within the recorded subject's interaction with laser light. If a true hologram is broken then each piece, when illuminated with laser light, describes the entire original subject from that unique point or angle of view. Holograms create a record of light originating from a monochromatic process. Any subsequent illumination of the hologram with white light di ffracts that white light, revealing an additive color palette present within that white light.

#### *1.2. The Most Famous Hologram That Is Not a Hologram*

The word hologram is misunderstood and misused in contemporary culture. The confusion runs as deep as the di fference between reality and a magician's sleight of hand. An online search of the word hologram results in pages of digital video display systems touting holograms of dead celebrities. These video display systems are based upon a "Pepper's Ghost" illusion and have next to nothing in common with holograms, nor do the majority of other related online listings. Princess Leia of Star Wars' fame is only a cinematic special e ffect. Yet she is probably the most famous hologram that is not a hologram. The misunderstanding and misuse of the word hologram contributes to the devaluing of the hologram, especially as an art medium.

Illusions fool us—we make them up in our minds. An illusion is an act of deception. Some optical illusions are interesting to observe, but an illusion can also point to an erroneous belief or false perception of reality. Even within the field of holography, some professionals refer to the material light forms created by true holograms as illusions. I refute this perception based on a simple example: If you make a true hologram of a lens, that hologram will manipulate and restructure the light in the exact same manner as the originating lens when illuminated with that same laser light. If that hologram of a lens is then illuminated with white light it begins to reveal the character of the illuminating white light. The hologram acts like a prism by separating the white light into spectral colors that reveal the realm of the photon. This phenomenon is the essence of the hologram and demonstrates its inherent character. Holograms exist as an intermediary between our material existence and the mysteries held within light.

I perceive true holograms as one of the most beautiful and elegant discoveries in human history. They transform light—often perceived as non-material in character—into a tactile, multi-dimensional, and ethereal creation of material light. They are not illusions. They are true manifestations of light as material that call out to be experienced.

#### *1.3. Holograms and Their Source Information*

I define holograms as existing within two families: True holograms and illusionary holograms. At their foundation, true holograms are multi-dimensional manifestations of material light. The technique used in this process begins with a field of interfering coherent laser light. This light field then interacts with human-scaled three-dimensional subject matter. This interface translates the 3-dimensional content into a multi-dimensional field of light information. The accumulated laser light information is then recorded onto a glass plate coated with light-sensitive emulsion. The resulting light archive—the hologram—contains the content of the multi-dimensional laser light field. This hologram contains an extraordinary level of detail, quintessential to the realm of the photon. When you view a true hologram you are experiencing it in the present as well as seeing the period of time in which it was originally created. This ability to record time is a function of the light–space–time phenomenon. The light used to illuminate the hologram is restructured by that hologram, duplicating the time of its origination. Holograms are tangible, readable archives of light information that have been rendered directly from the realm of the photon.

Illusionary holograms originate from two-dimensional information bundles, primarily generated using digital information. These holograms use two or more sets of stereographic data to develop a stereoscopic illusion that the mind interprets as three-dimensional space. These stereo-holograms have the ability to display animated imagery—reproducing an illusion of time and depth. This enables the creator to fabricate a stereoscopic view manipulating a purely perceptual reality. This type of hologram is easier to realize as the needed two-dimensional source information for their production can be digitally produced.

The artworks I create are all one-of-a-kind true holograms produced using holographic emulsions developed and individually formulated in my studio. I view these emulsions as having a painterly quality. The varied formulas of emulsions I blend are analogous to an artist's paint and color palette. I work with laser light as if it were my brush. Both of these elements are integral in the methodology of content and process within my finished works. To add another layer of creative manipulation I sometimes paint, drip, and carve the emulsions on the glass substrate used in the finished works. I also integrate textured laser light during the exposure of the emulsions to texturize the material light forms—increasing their material context. Because of the simplicity of the holographic methodology I utilize, my artworks exhibit 180 degrees of parallax viewing. This broad parallax makes possible a metamorphosis of material light forms and color that can be seen from anywhere within visual sight of the artwork. I see this kinetic viewing character infused with multi-dimensionality as important elements in the evolution and appreciation of true holograms as a fine art medium.

#### *1.4. Early History of Holograms as Fine Art and Beyond into Quantum Holography*

In 1968 the American artist Bruce Nauman produced a series of holograms entitled "Making Faces (A-K)" (Nauman 1968). This series were the first holograms created by an artist of prominence. Nauman's holograms were recorded in the infinitesimally small time frame of approximately twelve nano-seconds. In this almost instantaneous exposure of the holographic emulsion, Nauman physically articulated his body and face into distorted facial expressions. He said about these contortions "I guess I was interested in doing a really extreme thing" (Nauman 2003). During the twelve nano-second exposure the laser light entered the surface of his skin, potentially integrating with his DNA, and archived its composition into the laser light via the light–space–time phenomenon. This laser light reflected from his body recorded its light information holographically into the light sensitive emulsion. DNA has a diameter of approximately 2 nanometers (Wikipedia 2019). This is only a factor of 300 times smaller than the wavelength of light used to record the holograms of Nauman. A photon of laser light, being smaller than an electron, is a factor of more than one million times smaller than DNA (Quora 2017). Considering the immense information storage capacity of photons (Emerging Technology 2016) within a field of laser light and combining that with the nature of the true hologram and its ability to record the entirety of the subject from an almost infinite number of point locations across its dimension, I hypothesize that the holograms of Bruce Nauman contain a composite holographic recording of his DNA. Currently I know of no device that would allow this DNA information to be retrieved. I view this series of holograms as one of the most profound artifacts created within the sphere of fine art. The recording of this instantaneous moment combined with the potential to document Nauman's DNA exemplifies the realm of the photon and the true hologram. Between 1966 and 1970 Nauman made several artworks in which he used his body to explore the role of the artist—and explore possibilities within the context of art to investigate psychological states and behavioral codes. Who better than Bruce Nauman to potentially be the first artist to convey the truth of his physical composition infused within the light information recorded in a true hologram?

#### **2. A Discussion of Artworks as Pollinators between the Terrestrial and Photonic Realms**

#### *2.1. Spherical Light Series: 2000 to Present*

The "Spherical Light" series (Figure 1) investigates the multi-dimensional expression of the hologram. These works encompass the realm of the photon interpreted through the true hologram as an expressive, immersive medium. The series began as an exploration into the impossibility of creating a two-dimensional flat hologram. Upon completion of the first piece, the realm of the photon began to reveal itself to me. As I moved around the piece an extraordinary polychromatic palette became evident. I realized that what I was observing was an elongation and layering of multiple color spectrums over one another. This palette of light expanded my vision of how I could use the medium of holography. I realized it could translate light's mysteries into the sphere of human existence. The work of Agnes Martin came to mind. Her work in exploring white and its disassembly into constituent colors—as evident below (cut) in "Untitled #2" (Miranda 2016) inspired an expansion of my insight and strengthened my explorations within the realm of the photon.

Based on my newfound realization of color, I then added dimensional content to the subsequent works in the series. I then genuinely began working in the multi-dimensional real-space of light within the medium of holography.

At first glance, the observed dimensional quality of these works is exceptionally subtle. They appear to be flat fields of color. By moving around the artwork its polychromatic character is realized. This trait is the fingerprint of the full-spectrum composition of white light. Through patient viewing an initially indistinct dimensional form floating within the boundaries of the artwork is discovered. With close examination this nebulous volume possesses a tactile material quality. Subtle textural keys begin to emerge assisting the viewer in spatially defining the multi-dimensional rendering of this tactile field of material light. Continuing to move—broadening the exploration of the artwork—a

transformative morphing character is recognized. What is discovered is a curved form within the hologram. With further observation this form evolves into a fractional section of a large spherical form. This sphere is spatially located deep within the artwork. In my comprehension this spherical form may have a diameter of 30 to 40 feet. Conceptually, this hologram contains the entirety of that dimensional sphere. This exemplifies the definition of the word hologram (whole message). I see this spherical light form as a portal into the realm of the photon that can be perceived with the naked eye.

**Figure 1.** "Apollo" Spherical Light series, 2001. Three views of a single artwork. 54 cm × 54 cm, created by the author.

#### *2.2. Acceleration Series: 2002 to Present*

The "Acceleration" series of artworks (Figure 2) addresses the need to accelerate our perceptual evolution to keep pace with our technological revolution. At the time of initiating this series I was reflecting on the work of Joseph Albers' "Homage to the Square" (Albers 1951). Albers had explored halation, the phenomenon of edge contrast created by color-frequency light-wave interference. The holograms in this series were initially conceived to explore halation. They are compositions of two rectangular forms. In these works one rectangular form occupies a holographic space in front of the glass surface of the hologram while the second rectangular form resides behind the rear surface of the hologram. After the first holograms were made it became apparent that halation did not function within the multi-dimensional context of these works but the use of the rectangle remained a useful tool within my work. What became apparent as the two forms spatially move across each other was their colors and forms cross-pollinated, creating a third polychromatic light field of color and shape. The contours of this light field morph in shape, corresponding to how the two forms spatially overlap. The vivid color these forms present is a result of color mixing as the two rectangles spatially interact. These vibrant colors have their origin within the additive color palette inherent to this process of holography. The dimensional periphery of the light field exhibits a nebulous character, but with contemplation and imagination this subtle dimensional space reveals its multi-dimensional character and form.

Upon close examination and with total visual immersion within the rectangular form residing in the holographic space in front of the glass surface, this initially small rectangle increases in dimension filling the entire physical area of the artwork. The participatory content of total visual immersion within a field of material light can be a perception-altering event eliciting a degree of mystery and wonderment. These works act as portals assisting to increase the understanding of the conceptual territory of the hologram, the realm of the photon, and our tactile physical existence. My intent in these works is to stimulate a degree of physical and intellectual inquiry. The juxtapose states presented by the artworks, material as solid and material as light which possesses a multi-dimensional character, enabling comprehension of physical and non-physical existence to expand, evolve, and to be put into practice.

**Figure 2.** "Acceleration #4" Acceleration series, 2014 Three views of a single artwork. 63 cm × 53 cm, 2014, created by the author.

#### *2.3. Quantum Series: 2004 to Present*

These artworks (Figure 3) are a tendril originating from the Spherical Light series. The "Quantum" series cultivates a visual analogy as well as a potential actual instance of quantum states—a system that allows one single photon to be in two different locations at the same moment (Folger 2005). The series utilizes a system of controlled chaos. During the process of coating the light-sensitive holographic emulsion on the glass plate, centrifugal force combined with serendipitous and intentional aberrations result in holographic emulsions patterned with physical artifacts. These patterned fields of aberrations contain bubbles, have a dimensional surface texture, and are delicate in appearance. These patterns convey an abstracted but system-based motif. In the finished works the emulsion aberrations create a tangible solidity embedded within the piece. The holographic shadows of these aberrations occupy the holographic space in front of the glass surface of the hologram. The entwining of the physical emulsion aberrations with their holographic shadows creates a holographic amalgam. The commingling of the two states of the physical and the holographic, reference quantum states. Coincidently, this amalgam resembles a cosmic nebula. This blending of light as material and physical matter exemplifies the conceptual holographic sphere of perception. I view these works as doorways into an increased understanding of our quantum actuality, both symbolically and theoretically.

**Figure 3.** "Driving Through Smoke" Quantum series, 2014 Three views of a single artwork. 56 cm × 53 cm, created by the (cut) author.

#### **3. Personal History within the Medium of Holography**

After 10 years of sculpting metal as a sculptor/jeweler in the framework of the pictorial, I saw my first hologram in 1982. Four years later I opened my first holographic studio and continued to make holograms with pictorial content. In 1994 I experienced an exhibition of Bruce Nauman's "Clown Torture" (Clown Torture 1987) at the Walker Arts Center in Minneapolis, Minnesota. My initial response to the work was revulsion. I noticed a similar reaction from the others who had entered the gallery, most of whom left the gallery shaking their heads in disgust. At that moment, I realized the power of art to elicit a strong physiological and psychological response. One of the primary properties of holography that interested me is its ability to stimulate imagination and curiosity in the viewer. Experiencing "Clown Torture" has influenced my work ever since.

In 1996 I realized that light and the mysteries it holds should be the basis for my creative work. I then began to conceptualize the process of sculpting light and shaping photons into dimensional forms. I continued my studies surrounding light phenomenon and how they manifest in the environment. These included the Aurora Borealis, rainbows, sundogs, and light pillars.

Halo is a term used to describe a ring of light that forms around the sun or moon. I utilized the knowledge of this phenomenon to begin the "Halos" series of holograms in 1996. I used a minimal geometric ring form made of steel as the subject to initiate the conveyance of light's narrative. My intent was to engage the audience in the ideas surrounding light as a material. The reaction was very positive. The experiential content of these works was an added event that I had not fully anticipated. The viewers became tactilely interactive with the golden ring of light that was occupying the holographic space in front of the surface of the hologram. As people attempted to hold the material yet non-material ring of light I sensed expressions of delight. In later conversations about the work, amazement and mystery were common topics. I then realized the importance of integrating the individual human experience when presenting of the story of light through my work. Subsequently my content within the halos series expanded to laminating multiple holograms of the single ring into compositions consisting of multi-dimensional colleagues, utilizing up to three rings, and encouraging a tactile interaction.

This experience confirmed one of the most interesting and unique properties of this medium. True holograms, with their intrinsic content of mystery, have the ability to evoke a physiological and psychological response. I see this response as being similar to what Nauman's "Clown Torture" (Public Delivery 2019) evoked but having the opposite character of curiosity and sense of wonder. Other mediums such as virtual reality, 3D movies, or James Turrell's "Afrum 1" (Turrell 1966) a light projection work, are able to kindle similar responses. These are all illusions created within our minds through visual cues. I view illusion as removing the potential for imagination by generating fantasy—they do not expand our awareness of the world. By using the medium of the true hologram I hope to assist in the acceleration of our perceptual evolution into an inclusive, holistic system.

A significant motivation within my artistic practice is to encourage and develop a deep appreciation and understanding of light. It has created and sustained life for eons. We have delighted in its beauty through the spectrum of its color composition. Light as a photon exists as energy. We now exist in a world in which humans are not in equilibrium with the natural world. This imbalance can be resolved by developing a deeper and more integrated relationship with light and the energy that it transports. Through the creation of my holographic light-based artworks I aspire to bring into reality an evolution of human perception. This profundity of thought could result in an awakening, encompassing and developing a methodology that embraces a holistic understanding of light, its mysteries, attributes, and the appropriate use of the solar energy that is supplied to us on a daily bases.


**3. The ER-stress-induced NRP-mediated cell death response**

NRP-mediated cell death signaling is a distinct, plant-specific branch of the ER stress path‐ way that has been uncovered in soybean and has been shown to integrate the ER and osmot‐ ic stress signals into a full response. This integrative pathway was first identified through genome-wide approaches and expression profiling, which revealed the existence of a mod‐ est overlap of the ER and osmotic stress-induced transcriptomes in soybean seedlings treat‐ ed with PEG (an inducer of osmotic stress) or tunicamycin and AZC (potent inducers of ER stress; Irsigler et al., 2007). The co-regulated genes were first considered to be downstream targets of the integrated pathway based on similar induction kinetics and a synergistic re‐ sponse to the combination of osmotic and ER stress-inducing treatments. Based on these cri‐

teria, the selected downstream components of this ER and osmotic stress responseintegrating pathway encode proteins with diverse roles, such as plant-specific development and cell death (DCD) domain-containing proteins (NRP-A and NRP-B), an ubiquitin-associ‐ ated (UBA) protein homolog and NAC domain-containing proteins (GmNAC6). Among them, NRP-A and NRP-B were the first ones to be characterized and to show to induce a cell death response when ectopically expressed in tobacco leaves or soybean protoplasts (Costa et al., 2008). As a consequence, the ER and osmotic stress response-integrating pathway has been designated as the NRP-mediated cell death response.

An upstream component of the NRP-mediated cell death response, GmERD15 (*Glycine max* Early Responsive to Dehydration 15), has been recently identified using one-hybrid screen‐ ing that targeted the NRP-B promoter in yeast (Alves et al., 2011). GmERD15 is induced by ER and osmotic stress to activate the expression of *NRP* genes (NRP-A and NRP-B). Up-reg‐ ulation of NRP-B leads to the induction of an NAC domain-containing protein, GmNAC6, which is a critical mediator of stress-induced cell death in plants (Faria et al., 2011). These components of the ER stress-induced NRP-mediated cell death signaling pathway, GmERD15, NRPs and GmNAC6, have been further characterized.

## **3.1. GmERD15 is a ssDNA binding transcriptional activator**

The Early Responsive Dehydration (ERD) genes are rapidly induced in response to water deficit and form a family comprised by ERD1 to ERD16 representatives. The ERD encoded proteins exhibit diverse and heterogeneous biochemical functions and fall into different classes of proteins, such as chloroplast ATP-dependent protease (ERD1), cytosolic HSP70 (ERD2), glutationa-S-transferases (ERD9,ERD11, ERD13) among others (Soitano et al., 2008; Kiyosue et al., 1994; Kiyosue et al., 1993). ERD15 was first identified in Arabidopsis as a hy‐ drophilic protein that possesses a PAM2 domain that interacts with polyA-binding proteins (PABP11; Kiyosue et al., 1994; Kariola et al., 2006)., ERD15 has been shown to function as a negative regulator of the abcisic acid (ABA)-mediated response (Kariola et al., 2006). Over‐ expression of ERD15 reduces the ABA sensitivity of Arabidopsis, whereas silencing of ERD15 by RNAi promotes hypersensitivity to the hormone. The negative effect of ERD15 on ABA signaling enhances salicylic acid-dependent defense because overexpression of ERD15 was associated with increased resistance to the bacterial necrotroph Erwiniacarotovora, and the enhanced induction of marker genes for systemic acquired resistance. These results are consistent with the observed antagonistic effect of ABA on salicylic acid-mediated defense and may implicate ERD15 as a shared component of these responses.

The soybean GmERD15 homolog has been described as a new ER stress- and osmotic stress-in‐ duced transcription factor that binds to the promoter and induces the expression of the NRP-B gene. In fact, GmERD15 was isolated by its capacity to associate stably with the promoter of NRP-B in yeast cells using the one-hybrid system (Alves et al., 2011). The GmERD15 binding site in the NRP-B promoter was mapped to a 12-bp palindromic sequence (511 AG‐ CAnnnnTGCT -500) that resembles binding sites for ssDNA binding proteins, such as NF1C and PBF2 that recognize the sequences -TTGGCnnnnnGCCAA-3' and 5- TGACAnnnnTGT‐ CA-3', respectively (Wang and Kiledjian., 2000). Furthermore, GmERD15 is located in the nu‐ cleus, and chromatin immunoprecipitation (ChIP) assays revealed that it binds to the NRP-B promoter in vivo (Alves et al., 2011). The ectopic expression of GmERD15 in soybean cells acti‐ vates the NRP-B promoter and induces NRP-B expression. Collectively, these results indicate that GmERD15 functions as an upstream component of the NRP-mediated cell death signal‐ ing pathway that is induced by ER stress and osmotic stress

### **3.2. NRPs: Molecular and functional characterization**

teria, the selected downstream components of this ER and osmotic stress responseintegrating pathway encode proteins with diverse roles, such as plant-specific development and cell death (DCD) domain-containing proteins (NRP-A and NRP-B), an ubiquitin-associ‐ ated (UBA) protein homolog and NAC domain-containing proteins (GmNAC6). Among them, NRP-A and NRP-B were the first ones to be characterized and to show to induce a cell death response when ectopically expressed in tobacco leaves or soybean protoplasts (Costa et al., 2008). As a consequence, the ER and osmotic stress response-integrating pathway has

A Comprehensive Survey of International Soybean Research - Genetics, Physiology, Agronomy and Nitrogen

An upstream component of the NRP-mediated cell death response, GmERD15 (*Glycine max* Early Responsive to Dehydration 15), has been recently identified using one-hybrid screen‐ ing that targeted the NRP-B promoter in yeast (Alves et al., 2011). GmERD15 is induced by ER and osmotic stress to activate the expression of *NRP* genes (NRP-A and NRP-B). Up-reg‐ ulation of NRP-B leads to the induction of an NAC domain-containing protein, GmNAC6, which is a critical mediator of stress-induced cell death in plants (Faria et al., 2011). These components of the ER stress-induced NRP-mediated cell death signaling pathway,

The Early Responsive Dehydration (ERD) genes are rapidly induced in response to water deficit and form a family comprised by ERD1 to ERD16 representatives. The ERD encoded proteins exhibit diverse and heterogeneous biochemical functions and fall into different classes of proteins, such as chloroplast ATP-dependent protease (ERD1), cytosolic HSP70 (ERD2), glutationa-S-transferases (ERD9,ERD11, ERD13) among others (Soitano et al., 2008; Kiyosue et al., 1994; Kiyosue et al., 1993). ERD15 was first identified in Arabidopsis as a hy‐ drophilic protein that possesses a PAM2 domain that interacts with polyA-binding proteins (PABP11; Kiyosue et al., 1994; Kariola et al., 2006)., ERD15 has been shown to function as a negative regulator of the abcisic acid (ABA)-mediated response (Kariola et al., 2006). Over‐ expression of ERD15 reduces the ABA sensitivity of Arabidopsis, whereas silencing of ERD15 by RNAi promotes hypersensitivity to the hormone. The negative effect of ERD15 on ABA signaling enhances salicylic acid-dependent defense because overexpression of ERD15 was associated with increased resistance to the bacterial necrotroph Erwiniacarotovora, and the enhanced induction of marker genes for systemic acquired resistance. These results are consistent with the observed antagonistic effect of ABA on salicylic acid-mediated defense

The soybean GmERD15 homolog has been described as a new ER stress- and osmotic stress-in‐ duced transcription factor that binds to the promoter and induces the expression of the NRP-B gene. In fact, GmERD15 was isolated by its capacity to associate stably with the promoter of NRP-B in yeast cells using the one-hybrid system (Alves et al., 2011). The GmERD15 binding site in the NRP-B promoter was mapped to a 12-bp palindromic sequence (511 AG‐ CAnnnnTGCT -500) that resembles binding sites for ssDNA binding proteins, such as NF1C and PBF2 that recognize the sequences -TTGGCnnnnnGCCAA-3' and 5- TGACAnnnnTGT‐ CA-3', respectively (Wang and Kiledjian., 2000). Furthermore, GmERD15 is located in the nu‐

been designated as the NRP-mediated cell death response.

Relationships

264

GmERD15, NRPs and GmNAC6, have been further characterized.

and may implicate ERD15 as a shared component of these responses.

**3.1. GmERD15 is a ssDNA binding transcriptional activator**

The N Rich Protein (NRP) gene was first identified by its rapid induction in response to pathogen incompatible interactions in soybean (Ludwig and Tenhaken, 2001). The NRP des‐ ignation was derived from its high content of asparagine residue, about 25 %. NRP is repre‐ sented in the soybean genome by a small family of three genes: NRP-A, NRP-B and NRP-C. The encoded proteins share a highly conserved development and cell death (DCD) domain at the C-terminal portion in addition to a high content of asparagine residues at their more divergent N termini. The asparagine rich domain is not well characterized but harbors puta‐ tive glycosylation and myristoylation sites that may be relevant for function. The DCD do‐ main is found exclusively in plant proteins and it is composed of about 130 amino acid residues, organized into several conserved motifs: FGLP and LFL in the N-treminal region of the domain, PAQV and PLxE at its C-terminus (Tenhaken et al; 2005). DCD domain-con‐ taining proteins may be subdivided into four groups, according to the localization of the DCD domain in the primary structure. NRPs belong to the the subgroup I of DCD domaincontaining family of proteins, as their domains are located at the C-terminal portion of the protein (Tenhaken et al; 2005).

NRPs are critical mediators of ER and osmotic stress-induced cell death in soybeans (Costa et al., 2008). The cell death response mediated by NRPs resembles a programmed cell death event. The overexpression of NRPs in soybean protoplasts induces caspase-3-like activity and promotes extensive DNA fragmentation. Furthermore, the transient expression of NRPs in plants causes leaf yellowing, chlorophyll loss, malondialdehyde production, ethylene evolu‐ tion and the induction of senescence marker genes, which are hallmarks of leaf senescence.

NRPs are up-regulated by ER or osmotic stress but need both stress signals for full induction (Isrigler et al., 2007). This synergistic interaction of both signals upon NRP induction indi‐ cates that the ER stress and osmotic stress responses converge at the level of gene expression to potentiate a NRP-mediated cell death response (Costa et al., 2008). NRPs are also upregulated by other abiotic and biotic signals, such as salt stress, oxidative stress and patho‐ gens. Because the NRP-mediated cell death signaling pathway represents a shared response to multiple stress signals in plants, it might permit coordinate adaptive cellular responses under a large array of stress conditions

#### **3.3. GmNAC6 as a downstream component of the NRP-mediated cell death response**

NAC domain-containing proteins are plant-specific transcriptional factors that are ex‐ pressed in several tissues and developmental stages. The NAC transfactors are organized in‐ to a general structure that consists of a highly conserved N-terminal domain involved in

DNA binding (called NAC domain) and a C-terminal region highly divergent in sequence and length that functions as the activation domain. The NAC domain was derived from comparison of consensus sequences among NAM from Petunia, ATAF1/2 and CUC2 from Arabidopsis (Souer et al., 1996.). It comprises nearly 160 amino acid residues, divided into five subdomains (A–E) exhibiting a negative net charge and a nuclear localization signal (Xie et al., 1999; Seoet al., 2008). The subdomains A, C and D are conserved among plant species whereas B and E subdomains are variable (Ooka et al., 2003). The C- terminus har‐ bors a protein-protein interaction domain in some NAC-containing proteins while a trans‐ membrane domain is present in other transcriptional factors (Seo et al., 2008). Therefore, the NAC family is comprised by both soluble, nuclear transactivators and membrane proteins.

The members of the NAC gene family are involved in a variety of developmental events and defense responses, such as shoot apical meristem formation and maintenance (SAM; Aida et al., 1997; Souer et al.,1996; Weir et al., 2004), hormone signaling (Fujita et al., 2004; Xie et al., 2000), response to pathogen infection (Ren et al., 2000; Selth et al., 2005; Xie et al., 1999), leaf senescence (John et al., 1997) and response to different abiotic stresses (Hegedus et al., 2003; Tran et al.,2004).

The soybean NAC family is comprised by 180 putative sequences of NAC domain-contain‐ ing proteins, which display different expression profiles in response to distinct environmen‐ tal stress conditions and developmental signals (Mochida et al.,2009; Mochida et al., 2010; Wang et al., 2010). Frequently, the stress-induced expression profile of the soybean NAC genes reflects the functional profile of the encoded protein (Pinheiro et al., 2009). GmNAC6 was identified by its synergistic induction in response to a combined treatment of inducers of osmotic stress (polyethylene glycol) and ER stress (tunicamycin) and was functionally linked to the NRP-mediated cell death response (Faria et al., 2011). Transient expression of GmNAC6 promotes cell death and hypersensitive-like responses *in planta*. GmNAC6 and NRPs also share overlapping responses to biotic signals, but the induction of NRPs peaks before the increased accumulation of GmNAC6 transcripts. Consistent with the delayed ki‐ netics of GmNAC6 induction, increased levels of NRP-A and NRP-B transcripts induce pro‐ moter activation and the expression of the GmNAC6 gene. Therefore, GmNAC6 is biochemical and functionally linked to the ER stress- and osmotic stress-integrating cell death response, in which it acts downstream of the NRPs.

GmNAC6 encodes a 33kDa protein that belongs to the TERN (Tobacco elicitor-responsive gene encoding NAC domain protein) group of the NAC family, which is induced by elici‐ tors of the pathogen response (Ooka et al.,2003). Likewise, GmNAC6 is induced by the pathogenic bacteria *Pseudomonas syringaepatovar tomato* which elicits an incompatible interac‐ tion in soybean and by cell wall-degrading enzymes, which mimic bacterial pathogen attack. Like GmNAC6, the other components of the ER- and osmotic-stress induced cell death sig‐ naling pathway, GmERD15 and NRPs, are also induced by other biotic and abiotic signals, such drought and pathogen incompatible interactions. Therefore, the activation of the NRPmediated senescence-like response is not specific to ER stress or osmotic stress but is, rather, a shared branch of general environmental adaptive pathways.


**1. Introduction**

The adoption of biodiesel as a fossil fuel reduction strategy in Europe has created a demand for vegetable oil as a biodiesel feedstock and a new market for the canola oil grown in the Canadian Prairies. Canola is a variety of rapeseed developed in Canada which contains reduced levels of erucic acid, making its oil palatable for human consumption, and reduced levels of a toxic glucosin, which makes its meal a potential livestock feed. Because of the extracted canola oil being suitable for use as cooking oil, canola is considered to be a new and distinct crop from rape seed in Canada.

The market acceptability of canola oil as a biodiesel feedstock in Europe depends on the Carbon Footprint (CF) of its production being significantly lower than that of conventional diesel fuel [1]. In October 2012, The European Commission amended its directive relating to the quality of petrol and diesel fuel and the promotion of the use of energy from renewable sources. These amendments set mandatory margins for the amount of fossil CO2 required to be offset by biofuels. For biofuel installations in operation on or before 1 July 2014, biofuels must achieve a greenhouse gas emission savings of at least 35% until 31 December 2017 and at least 50% thereafter. If the physical production of biofuels starts after 1 July 2014, the greenhouse gas emission saving from the use of biofuels must be at least 60% of the fossil CO2 emissions of the equivalent petro-fuel energy.

These Directives also proposed a provision to address changes in the indirect land use given that current biofuels are mainly produced from crops grown on existing agricultural land. Therefore, if the demand for canola biodiesel continues to increase, questions arise about where the additional feedstock would be grown. The first goal of this chapter was to assess the impact

© 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

of expanding canola production on beef production in the Prairie Provinces of Canada. The scope of this assessment excludes any substitution of beef with non-ruminant livestock in response to canola expansion. The second goal was to determine the feedback effect from this impact on the Greenhouse Gas (GHG) emission cost of canola biodiesel.


**2. Growth techniques of hydrogenated microcrystalline silicon**

The growth of µc-Si:H material uses silane (SiH4) and hydrogen as source-gas. It is currently admitted that free radical precursors (SiHx)-SiH3 is suspected to favor the µc-Si:H growthand H-enhances crystalline growth by etching of looser a-Si:H tissue-were needed to attain microcrystalline growth. In order to obtain such reactive species, decomposition of the source-gases is necessary. At first, this was obtained by using PE-CVD at high temperatures (600°C). The use of low deposition temperatures of 200-300°C with a plasma present in the

Novel Deposition Technique for Fast Growth

temperature plasma.

Microwave current, (b) Electric field.

(a) Microwave current

of Hydrogenated Microcrystalline Silicon Thin-Film for Thin-Film Silicon Solar Cells 361

is based on an inter-digital filter composed of parallel cylindrical rods (spokes) arranged between parallel-grounded plates. The spokes are resonantly coupled by the stray capacitance between adjacent spokes and the inductance of the spokes themselves. The resonance condition of an introduced angular frequency is given by ω=2π*f*=1/(C×L)1/2, where *f* is the introduced frequency, C is the array capacitance, and L is the antenna inductance. Thus, the antenna operates as a band-pass filter. The spokes are arranged like those in a wheel, and the plasma serves as one of the grounded plates. The electromagnetic wave propagates through the spokes consecutively with a phase difference of 90°, and microwave current flows in every spoke. The current in the spokes couples inductively and capacitively to the plasma ("CM coupling"), and the induction current in the plasma accelerates the electrons to sustain the plasma, as shown in Fig. 2 & 3. The power is supplied from the center of the antenna, and the plasma under the spoke antenna is radially discharged because induction current flows near every spoke. As a result, uniform microwave plasma over an area of diameter greater than 20 cm can be generated efficiently. As well, since no magnetic field is required to generate the high-density microwave plasma, it is possible to design a simple source yielding high-density and low-

Fig. 2. The newly developed spoke antenna for introduction of microwave power (a)

*Power supply*

From a material processing standpoint, large-area microwave plasmas (MWPs) have several advantages in comparison with other types of high-density sources. First, MWPs, being no magnetized sources, are free from such magnetic field induced problems as inhomogeneous density profile and charge-up damage, which is often, experienced in electron cyclotron resonance (ECR) or helicon plasma sources. Second, MWPs can be enlarged to diameters

E E

(b) Electric field

E

E

deposition chamber, the so called Plasma-Enhanced Chemical Vapor Deposition technique (PE-CVD) was developed later on and allowed the low-temperature deposition of µc-Si:H films, and rapid progresses have been achieved. Unfortunately, "state-of-the-art" microcrystalline silicon solar cells consist of intrinsic µc-Si:H layers that are deposited by rf and VHF PE-CVD at deposition rates of only 1-5 Å/s. On the other hand, a µc-Si:H film with a 2-µm- thickness intrinsic absorption layer is required for application to Si thin-film solar cells because of the low optical absorption in the visible region. The µc-Si:H i-layer deposition step is the most time consuming step in the deposition sequence of the solar cell. Therefore, a novel fast deposition technique of µc-Si:H is required.


**2. The globalization of the pandemic**

At present, there is evidence that globalization has affected health care in a variety of ways. In this sense, the majority of the most prestigious institutions and organizations in the field of public health have become standard-bearers for the concept of global health. As such, the concept of global health is a consequence of the process of globalization. The definition of global health pursues equity in health matters worldwide; it is a priority objective for the international technocratic agenda [1].

The globalization process, with its multiple dimensions (economic, political, social, ecological, etc.), has had a significant impact on global health. For instance, economic globalization through the internationalization of trade and the communications revolution has resulted in the globalization of risks and of certain diseases [2]. In addition, ecological globalization, alongside the environmental and ecological changes it entails, has also had an effect on health [3]. This can be illustrated by the following: water deprivation due to scarcity implies major health risks; air pollution has caused an increase in respiratory diseases; climatic change with its ensuing extreme temperature variations affect cardiovascular diseases and the depletion of the ozone layer has increased the incidence of skin cancer [4]. On the other hand, the interde‐ pendence generated between governments and transnational problems, characteristic of political globalization, have shifted power away from the State in favour of the creation of international institutions. Thus, the World Health Organisation is today the largest exponent of health, while UNAIDS serves this purpose in the case of HIV.

Consequently, social phenomena such as health tourism, the migration of health professionals to developed countries, the existence of global risks, the resurgence of diseases that had previously been limited (such as tuberculosis) in developed countries and the global emer‐ gence of infectious diseases (avian influenza, HIV, etc.) are greatly related to the globalisation process. Specifically, globalisation has important repercussions for emerging infectious diseases: "Since the 1970s, newly emerging diseases have been identified at the unprecedented rate of one or more per year. There are now at least 40 diseases that were unknown a generation ago" [5].

In general terms, the relationship established between globalization and global health is not a positive one. However, it is worth noting that globalization has also had a positive impact on certain aspects of global health, given that it offers opportunities and provides improvements related to population health. For instance, globally, the total poverty rate has declined from 20% to 5% over the past 25 years [6]. Globalization, to the extent that it produces greater economic growth, generally involves improvements in population health. For instance, globalization has resulted in better health care conditions. This is evidenced by the success achieved in relation to children's nutritional status and mortality among breast-fed babies, as demonstrated by specific indicators, greater opportunities for health care choices (patients whose health problems cannot be treated in their own countries can explore the international health care available and choose the most convenient option), an increase in the external aid of developed countries as evidenced by the MDGs in the case of malaria, tuberculosis and HIV (the containment of the spread of AIDS in many countries through the implementation of prevention programmes) [7], and the fact that new information and communication technol‐ ogies enable health professionals from anywhere in the world to access scientific evidence and improve their clinical decisions [6].

Concerning the objective of this chapter, however, the relationhip established between globalization and HIV is robust. So much so that HIV, along with other diseases such as tuberculosis and malaria, is presently termed a "global disease". To a large extent, this is the result of the movement of goods and people, which has also increased the likelihood of diseases spreading worldwide. Diseases, like goods and people, also commute across oceans and borders. For this reason, one of the main concerns of international public health is the speed, as well as the high rates, of the worldwide spread of highly contagious diseases, as illustrated recently by the alarm triggered concerning Ebola infection.

HIV is a clear exponent of transnationalization and constitutes a global epidemic that now poses one of the major threats to global health. Such has been the scope of the pandemic and the resulting consequences that today, it can be affirmed that HIV represents one of the most severe public health epidemics ever suffered by humanity. Therefore, considering the gravity of the situation, the international organism UNAIDS was created to respond to this issue.

According to an UNAIDS 2013 report, it is estimated that on a global scale, 35.3 million people were living with HIV in 2012, an increase compared to previous years [8]. This is largely due to greater accessibility to treatment. In other words, there are progressively more people in the world receiving antiretroviral therapy, which raises their life expectancy. The distribution according to population group is 31.8 million adults and 3.2 million children [8]; 2.3 million new cases of HIV infection were reported throughout the world in 2013, compared to the 3.4 million cases recorded in 2001 [8]. Consequently, these figures show that there has been a decline of approximately 33%. In the case of new infections HIV in children, 240 000 children worldwide (210 00-280 000) contracted HIV in 2013, compared to 580 000 (530 000-640 000) in 2001, signifying a decrease of 58% [8]. Similarly, the number of deaths from AIDS has also declined: 1.6 million deaths were recorded in 2012, compared to 2.3 million recorded in 2005. Specifically, 1.3 million deaths occurred among adults and 190 000 among children.

Source: UNAIDS, 2013

**2. The globalization of the pandemic**

28 Trends in Basic and Therapeutic Options in HIV Infection - Towards a Functional Cure

of health, while UNAIDS serves this purpose in the case of HIV.

international technocratic agenda [1].

ago" [5].

At present, there is evidence that globalization has affected health care in a variety of ways. In this sense, the majority of the most prestigious institutions and organizations in the field of public health have become standard-bearers for the concept of global health. As such, the concept of global health is a consequence of the process of globalization. The definition of global health pursues equity in health matters worldwide; it is a priority objective for the

The globalization process, with its multiple dimensions (economic, political, social, ecological, etc.), has had a significant impact on global health. For instance, economic globalization through the internationalization of trade and the communications revolution has resulted in the globalization of risks and of certain diseases [2]. In addition, ecological globalization, alongside the environmental and ecological changes it entails, has also had an effect on health [3]. This can be illustrated by the following: water deprivation due to scarcity implies major health risks; air pollution has caused an increase in respiratory diseases; climatic change with its ensuing extreme temperature variations affect cardiovascular diseases and the depletion of the ozone layer has increased the incidence of skin cancer [4]. On the other hand, the interde‐ pendence generated between governments and transnational problems, characteristic of political globalization, have shifted power away from the State in favour of the creation of international institutions. Thus, the World Health Organisation is today the largest exponent

Consequently, social phenomena such as health tourism, the migration of health professionals to developed countries, the existence of global risks, the resurgence of diseases that had previously been limited (such as tuberculosis) in developed countries and the global emer‐ gence of infectious diseases (avian influenza, HIV, etc.) are greatly related to the globalisation process. Specifically, globalisation has important repercussions for emerging infectious diseases: "Since the 1970s, newly emerging diseases have been identified at the unprecedented rate of one or more per year. There are now at least 40 diseases that were unknown a generation

In general terms, the relationship established between globalization and global health is not a positive one. However, it is worth noting that globalization has also had a positive impact on certain aspects of global health, given that it offers opportunities and provides improvements related to population health. For instance, globally, the total poverty rate has declined from 20% to 5% over the past 25 years [6]. Globalization, to the extent that it produces greater economic growth, generally involves improvements in population health. For instance, globalization has resulted in better health care conditions. This is evidenced by the success achieved in relation to children's nutritional status and mortality among breast-fed babies, as demonstrated by specific indicators, greater opportunities for health care choices (patients whose health problems cannot be treated in their own countries can explore the international health care available and choose the most convenient option), an increase in the external aid of developed countries as evidenced by the MDGs in the case of malaria, tuberculosis and HIV (the containment of the spread of AIDS in many countries through the implementation of

**Table 1.** Structural indicators of HIV

Despite the progress that has been made, epidemiological data continues to show alarming figures, as reflected in Table 1. As such, there remain major obstacles in the eradication of the pandemic. According to UNAIDS' most recent report (2013), some of these challenges are [8]:

HIV constitutes a clear example of social inequality in relation to health. In overall terms, the highest prevalence of the pandemic occurs in countries with low human development indicators. This increases social injustice and accentuates existing inequalities in these countries. According a UNAIDS report (2013), some of the countries that present higher prevalence rates with regard to global prevalence are [8]:

Source: UNAID, 2013

1 Table 2 shows the existing discrepancies in the pandemic's global distribution; some countries show a higher HIV prevalence, according to a 2013 sample, while other continental regions show lower levels of prevalence.

**Table 2.** Prevalence rate of HIV infection in adults

Similarly, the overall distribution of AIDS-related deaths shows that the greatest incidence occurs in countries with low and moderate development rates: Nigeria (13%), South Africa (13%), India (8%), Mozambique (5%), United Republic of Tanzania (5%), Zimbabwe (4%), Uganda (4%), Kenya (4%), Malawi (3), Ethiopia (3%), China (2%), Russian Federation (2%), Democratic Republic of the Congo (2%) and Indonesia (2%)[8]. In the aforementioned coun‐ tries, the epidemic represents a major public health issue. Not only is it a medical and health care issue, but it also constitutes one of the major obstacles to economic and social development [9]. For example, the high percentage of adult AIDS-related deaths results in the loss of the youngest and most productive individuals in a society, who are vital to economic develop‐ ment. Economic productivity also decreases, because AIDS sufferers and their caregivers stop working. Additionally, the educational system in these countries is affected by the percentage of teachers who die from AIDS, which means the loss of a significant part of the most educated population. Furthermore, the health care expenditure generated by providing health care services for people living with HIV and AIDS entails budgetary restrictions within the public sector. This constrains investments in other sectors aimed at promoting social and economic development. Finally, the scope of the epidemic in these countries is increasing, deepening poverty and existing social inequalities, and consequently inverting the human development trend. The HIV/AIDS epidemic has therefore become a priority for public policies in these countries. As a result, the response to HIV/AIDS and the fight against poverty has become the same battle [10]. For this reason, the elimination of HIV/AIDS has been established as a Millennium Goal, the sixth MDG [11], specifying the need to: "Halt and begin to reverse the spread of HIV/AIDS by 2015". Thus, the inclusion of HIV as a Millennium Goal evidences the global acknowledgement of the destructive and generalized effects of HIV/AIDS, as well as the belief that it is possible to overcome the situation by means of greater and more intensive national and international action, as well as the active will to do so.

**1.** Reducing the sexual transmission of HIV in African countries where a decline in the use

**2.** Reducing HIV transmission among people who inject drugs, since data shows this

**3.** Reducing new infections in children, as well as maternal mortality during pregnancy. **4.** Improving the availability of and accessibility to antiretroviral therapy in low and middle-

**6.** Eliminating stigma, discrimination and coercive laws and practices in relation to HIV. **7.** Eliminating gender inequalities, abuse and violence that cause the feminization of HIV.

HIV constitutes a clear example of social inequality in relation to health. In overall terms, the highest prevalence of the pandemic occurs in countries with low human development indicators. This increases social injustice and accentuates existing inequalities in these countries. According a UNAIDS report (2013), some of the countries that present higher

Table 2 shows the existing discrepancies in the pandemic's global distribution; some countries show a higher HIV

Similarly, the overall distribution of AIDS-related deaths shows that the greatest incidence occurs in countries with low and moderate development rates: Nigeria (13%), South Africa

prevalence, according to a 2013 sample, while other continental regions show lower levels of prevalence.

remains highly prevalent, whereas HIV prevention coverage remains low.

**5.** Reducing the number of tuberculosis-related deaths in HIV patients.

of the masculine condom has been detected.

30 Trends in Basic and Therapeutic Options in HIV Infection - Towards a Functional Cure

**8.** The integration of people affected by HIV.

**9.** The overall lack of resources in the fight against AIDS.

prevalence rates with regard to global prevalence are [8]:

**Swaziland** 28.3% **Lesotho** 24.7% **Botswana** 24.4% **South Africa** 18.4% **Zimbabwe** 15.6% **Namibia** 15.2% **Mozambique** 12.9% **Malawi** 11.4% **Equatorial Guinea** 9.7% **North America** 0.8% **Canada** 0.3% **Western and Central Europe** 0.2%

**Country/ Region1 Prevalence of HIV (2012)**

income countries.

Source: UNAID, 2013

**Table 2.** Prevalence rate of HIV infection in adults

1


*3.2. Canopy Cover Estimation Using ITD-Based Method*

To guarantee the independence of the canopy cover estimates from different data sources and to minimize the influences of laser scanning data processing methods, individual tree delineations were manually conducted in the ULS and TLS point clouds separately. Automatic tree detection and modeling methods were not used in this study. Thus, the canopy cover evaluation results revealed the capacities of the applied laser scanning data while excluding the influence of the data processing approach, such as the individual tree detection. Then, each individual tree crown in a plot was accumulated and subtracted from the overlap area to calculate the total crown area. The ITD-based canopy cover was calculated as the percentage of the total crown area to the plot area. The ITD-based canopy cover estimation results from the ULS and TLS data are denoted as ULS\_ITD and TLS\_ITD, respectively, in the following sections.

#### *3.3. Comparison Scheme and Accuracy Assessment*

First, the four canopy cover estimates (ULS\_CHM, TLS\_CHM, ULS\_ITD, and TLS\_ITD) were compared with the reference data. Then, the agreement and disagreement in the canopy cover estimations from ULS and TLS were quantified in detail with respect to the CHM-based and ITD-based methods. Finally, the influence of the pixel size on canopy cover estimation in the CHM-based method from ULS and TLS was analyzed.

In this study, the accuracy of the estimated canopy cover was evaluated using the coefficient of determination (*R*2) and root mean squared error (*RMSE*), which were calculated using the following equations:

$$R^2 = 1 - \frac{\sum\_{i=1}^{n} (x\_i - y\_i)^2}{\sum\_{i=1}^{n} (x\_i - \overline{x})^2} \tag{2}$$

$$RMSE = \sqrt{\frac{\sum\_{i=1}^{n} (x\_i - y\_i)^2}{n}} \tag{3}$$

where *xi* and *yi* are the values from the *i*th reference and estimated canopy cover values, *x* is the mean of the reference canopy cover, and *n* is the number of plots.

#### **4. Results**

#### *4.1. Comparison of LiDAR Estimations and Reference*

A comparison between the canopy cover estimations from the four methods (i.e., ULS\_CHM, ULS\_ITD, TLS\_CHM, and TLS\_ITD) and the reference data are shown in Figure 4 (for all the plots) and Figure 5 (for the GG plots alone). As illustrated in Figure 4, there was an overall moderate to high agreement between the LiDAR-estimated canopy cover and the reference data for all the plots, with *R*2 values of 0.541–0.996, and *RMSE* values of 0.591–6.297%. Among the four methods, the ULS\_CHM method showed the highest accuracy, with an *R*2 of 0.996 and an *RMSE* of 0.591% for canopy cover estimation, while the ULS\_ITD method had the second highest accuracy, with an *R*2 of 0.992 and an *RMSE* of 0.820%, followed by the TLS\_ITD method (*R*2 = 0.846, *RMSE* = 3.642%) and the TLS\_CHM method (*R*2 = 0.541, *RMSE* = 6.297%).

**Figure 4.** Comparison of canopy cover estimations derived from the reference data and LiDAR estimations for all the plots. Scatter plots with *R*2, *RMSE*, and regression equations between reference data (y) and LiDAR-based estimations (x) are indicated for the (**a**) ULS\_CHM, (**b**) ULS\_ITD, (**c**) TLS\_CHM, and (**d**) TLS\_ITD estimations.

**Figure 5.** Comparison of canopy cover estimations derived from the reference data and LiDAR estimations for the GG plots alone. Scatter plots with *R*2, *RMSE*, and regression equations between reference data (y) and LiDAR-based estimations (x) are shown for the (**a**) ULS\_CHM, (**b**) ULS\_ITD, (**c**) TLS\_CHM, and (**d**) TLS\_ITD estimations.

As illustrated in Figure 5, the results from the GG plots alone showed a similar tendency, with the ULS\_CHM method showing the highest accuracy (*R*2 of 0.996, *RMSE* of 0.476%), followed by the ULS\_ITD method (*R*2 = 0.992, *RMSE* = 0.685%) and the TLS\_ITD method (*R*2 = 0.986, *RMSE* = 0.915%). The TLS\_CHM method had the lowest accuracy (*R*2 = 0.737, *RMSE* = 3.959%). For different forest conditions, the GG plots had a better performance (*R*2 = 0.737–0.996, *RMSE* = 0.476–3.959%) than all other plots (*R*2 = 0.541–0.996, *RMSE* = 0.591–6.297%).

The overestimation and underestimation of the four methods against the reference data are summarized in Table 1, which shows the difference between the ULS/TLS estimated canopy cover and the reference data for all the plots, the GG plots only, and the QZ plots only. Overall, the ULS produced smaller deviations than TLS. The mean deviation for the ULS was 2.1% for all the plots and 7.46% for TLS. The ULS\_CHM had the smallest deviations, followed by the ULS\_ITD, TLS\_ITD, and TLS\_CHM. In addition, the ULS canopy cover estimations were more robust across different stand conditions and different methods than the TLS estimations. The ULS produced similar deviations between the GG and QZ plots (2.08% vs. 2.13%), whereas significant differences were observed between the corresponding deviations of TLS (4.93% and 13.03%).

**Table 1.** Canopy cover differences (%) calculated as ULS/TLS estimations minus reference data for all the plots, the GG plots only, and QZ plots only, where |mean| represents the mean of the absolute values of the difference.

#### *4.2. The Agreement and Disagreement in the Estimations from ULS and TLS*

A more detailed comparison was conducted directly between the ULS and TLS estimations with respect to different forest conditions and estimation methods. The *R*2, *RMSE* and differences between the ULS and TLS estimations were summarized. The disagreement between the ULS and TLS estimations increased with increasing complexity of the forest stand with respect to these metrics.

A moderate agreement was observed between the ULS and TLS estimations when the CHM-based method was used. As illustrated in Figure 6a, the *R*2 and *RMSE* between the ULS\_CHM and TLS\_CHM estimations were 0.554 and 6.288% for all the plots. In the case of the ITD method, the *R*2 and *RMSE* between the ULS\_ITD and TLS\_ITD estimations were *R*2 0.859 and 3.600% for all the plots (Figure 6b). For different forest conditions, the GG plots had a higher agreement between the ULS and TLS estimations than all the plots. Figure 6c,d illustrates the comparison on the GG plots, where the ULS and TLS produced an *R*2 of 0.745 and an *RMSE* of 3.913% for the CHM-based method, and *R*2 of 0.985 and an *RMSE* of 0.919% for the ITD method.

Table 2 summarizes the difference between the ULS and TLS estimations for all the plots, the GG plots only, and the QZ plots only. The number of all plots, GG plots, and QZ plots were 16, 11 and 5 respectively. The ULS estimations were larger overall than the TLS estimations for the CHM-based method, with an averaged difference of 11.15% for all the plots. The overestimations in the GG plots were lower than those in the QZ plots. The average overestimation was 8.19% for the GG plots and 17.65% for the QZ plots (Table 2). For the ITD-based method, the TLS estimations tended to be larger in the GG plots and lower in the QZ plots than the ULS estimations (Figure 6b). Only two plots had lower TLS\_ITD estimations than the ULS\_ITD estimations (Figure 6b). In the QZ plots, the average TLS\_ITD estimations were 5.97% lower than ULS\_ITD estimations.

**Table 2.** Canopy cover differences (%) calculated as ULS estimations minus TLS estimations for all the plots, GG plots only, and QZ plots only, where |mean| represents the mean of the absolute values of the difference.

**Figure 6.** Comparisons of canopy cover estimations derived from ULS and TLS: (**a**,**b**) for all the plots, and (**c**,**d**) for only the GG plots.

#### *4.3. Estimation Results of CHM-Based Canopy Cover with Different Pixel Size*

Changes in *R*2 and *RMSE* between the CHM-based estimations using different pixel sizes and the reference data are presented in Figure 7. For the ULS\_CHM method, the *R*2 between the ULS\_CHM estimations and the reference data decreased with an increase in the pixel size (Figure 7a). The *R*2 decreased slowly from 0.996 to 0.959 with an increase in the pixel size range from 0.07 m (raw pixel size) to 1.2 m. The decrease rate of *R*2 was significantly larger after the pixel size exceeded 1.2 m. Conversely, the *RMSE* values increased as the pixel size increased.

For the TLS\_CHM method, *R*2 initially increased and then decreased with increasing pixel size (Figure 7b). The *R*2 between the TLS\_CHM estimations and reference data increased from 0.541 to 0.871 when the pixel size range increased from 0.01 m (raw pixel size) to 1.0 m. After the pixel size surpassed 1.0 m, *R*2 rapidly decreased. The *RMSE* values first decreased and then increased as the pixel size increased.

**Figure 7.** Changes in *R*2 and *RMSE* between two CHM-based canopy cover estimations using different pixel sizes and reference data. (**a**) *R*2 and *RMSE* between ULS\_CHM estimations and reference data and (**b**) *R*2 and *RMSE* between TLS\_CHM estimations and reference data.

#### **5. Discussion**

#### *5.1. Differences between LiDAR-Derived Canopy Cover and Reference Data*

In this study, we compared four LiDAR-estimated canopy covers (ULS\_CHM, ULS\_ITD, TLS\_CHM, and TLS\_ITD) with the reference data. The ULS\_CHM produced the highest accuracy, followed by ULS\_ITD, TLS\_ITD, and TLS\_CHM. The results demonstrated that the canopy covers obtained using the ULS\_CHM method were slightly higher than the reference data, and the canopy covers obtained from the other three methods were lower than the reference data. The higher canopy cover estimations obtained from the ULS\_CHM method could be partly attributed to the following aspects: (i) some small between-crown gaps with similar size of within-crown gaps were also filled as canopy pixels, and (ii) the crown boundaries that adjoined the open ground in the horizontal plane tended to expand after the interpolation procedure of the pit-free method.

Since the original CHM method would underestimate the canopy cover owing to the existence of within-crown gaps, we utilized the pit-free method proposed by [38] to fill the within-crown gaps to mitigate the underestimation. Our results showed that the pit-free method could effectively remove the within-crown gaps (c1 and c2 in Figure 8a,b). However, the small between-crown gaps with similar within-crown gap size were also interpolated as canopy pixels (d1 and d2 in Figure 8a,b), and the crown boundaries adjacent to the open ground expanded after the pit-free method was applied (e1 and e2 in Figure 8a,b). It was difficult to distinguish between the within-crown gaps and the between-crown gaps with similar sizes and fill the within-crown gaps while ensuring that the between-crown gaps remained unchanged in the CHM smoothing process. The crown boundaries adjacent to the open ground expanded because there were height jumps between the crown boundaries and the adjoining ground. The pit-free method interpolated the pixel values of the adjoining ground and increased their height to reduce the height difference. Thus, several ground pixels were classified as canopy, and the canopy cover was slightly magnified.

In the TLS\_CHM method, the canopy cover estimation was lower than the reference, which could be attributed to the incomplete tree crown structure generated from the TLS point clouds. Although the multi-scan mode was used in the TLS data collection, the crowns further away remained occluded when the laser beam was interrupted by stems or branches, and the upper crown of the higher trees was incomplete due to the limited field of view in the vertical direction (−40◦–60◦). These situations produced within-crown gaps, and these gaps could not be completely removed by the pit-free method, resulting in the underestimation of the TLS\_CHM method.

**Figure 8.** The pit-free method used in the ULS\_CHM canopy cover estimation, where (**a**,**b**) represent the original CHM and the pit-free CHM, respectively, while (c1) (c2), (d1) (d2), and (e1) (e2) represent the within-crown gaps, between-crown gaps, and crown boundaries adjacent to the open ground in the original CHM and the pit-free CHM.

Both the ULS\_ITD and TLS\_ITD canopy cover estimations were smaller than the reference data, because the reference data were produced from the fused ULS and TLS point clouds. The TLS\_ITD canopy cover estimations were lower when the crown boundaries were incomplete in the TLS point clouds. The slightly lower ULS\_ITD estimations could be partly attributed to the lower point density of the ULS point clouds when compared with the fused point clouds.

#### *5.2. Difference between ULS-Derived and TLS-Derived Canopy Cover Estimations*

In the CHM method, our results demonstrated that the ULS estimations were larger than the TLS estimations for all the plots. The differences between the ULS\_CHM and TLS\_CHM estimations increased with the increased forest complexity. In the ITD method, the ULS estimations were smaller than the TLS estimations in the simple plots with little understory vegetation and low stem density (GG plots), and the ULS estimations were larger than the TLS estimations in the relatively complex plots with abundant understory growth and higher stem density (QZ plots).

Overall, the ULS tree crowns were more comprehensive than the TLS tree crowns, even when the multi-scan mode was used. Similar results were reported by [28], where ALS produced slight overestimation of canopy cover and TLS underestimated the canopy cover. TLS was vulnerable to the radial occlusion due to the side view perspective and produced gaps within the crowns. These gaps were large and difficult to fill by the CHM smooth method (pit-free), resulting in lower TLS estimations in the CHM-based method. This underestimation grew with increased forest complexity due to the increased occlusion. The QZ plots had denser understory vegetation and higher stem density than the GG plots, resulting in more occlusions in TLS than the GG plots. Therefore, the difference between the ULS\_CHM and TLS\_CHM estimations for the GG plots (Figure 9) was smaller than that of the QZ plots (Figure 10).

**Figure 9.** Difference between ULS\_CHM and TLS\_CHM in GG plot: (**a**,**c**) normalized ULS and TLS point clouds, and (**b**,**d**) corresponding pit-free CHMs.

**Figure 10.** Difference between ULS\_CHM and TLS\_CHM in QZ plot: (**a**,**c**) normalized ULS and TLS point clouds and (**b**,**d**) corresponding pit-free CHMs.

In the ITD method, the TLS estimations were larger than the ULS estimations in simple plots, which can be partly attributed to the denser point density of the TLS point clouds and the fact that the incomplete tree crowns could be recovered as long as crown boundaries existed in the ITD method. The crown boundaries in the simple plots with little understory vegetation and low stem density were more likely to be collected than those in the relatively complex plots with abundant understory growth and higher stem density. Moreover, compared with the ULS crowns, the TLS crowns represented more details and larger areas (as illustrated in Figure 11e). The TLS crown boundaries were more compact, and their between-crown gaps were smaller than those of the ULS (Figure 11b,d). Therefore, the TLS\_ITD produced slightly higher estimations than ULS in the simple plots. However, there were two GG plots that produced lower TLS\_ITD estimations because their tree crown boundaries were incomplete and the ITD method could not recover the correct crowns areas.

**Figure 11.** Difference between ULS\_ITD and TLS\_ITD in GG plot: (**a**,**c**) normalized ULS and TLS point clouds, (**b**,**d**) corresponding individual tree crown boundaries, and (**e**) the local detail for the overlapped ULS and TLS crown points.

For the QZ plots, the TLS estimations were lower than the ULS estimations in the ITD method. As illustrated in Figure 12b,d, the QZ plots had denser understory vegetation and higher stem density than the GG plots, which led to more severe occlusion and incomplete tree crowns in the TLS point clouds. The crown boundaries were incomplete and the ITD method cannot recover the correct crowns areas, resulting in the underestimation.

**Figure 12.** Difference between ULS\_ITD and TLS\_ITD in QZ plot: (**a**,**c**) the normalized ULS and TLS point clouds and (**b**,**d**) corresponding individual tree crown boundaries.


**Acknowledgement**

Morris Self-Report Low Back Pain Disability Questionnaire (RMDQ) was 9/24 or 37.5% self-

*Sagittal*: Treatment began with sagittal plane control of pelvis and thorax to improve critical respiratory core muscle control. JP started in hooklying and supine 90–90 postures to begin activities like supine 90–90 with balloon blowing versions (see **Figure 15**). Once postural test-

*Frontal*: For this patient, the left sidelying position was felt to be best to help her begin to control frontal and transverse plane forces particularly in the region of her left lower lumbar spine, which were the most likely source of her debilitating sciatica. As JP gained control of the left abdominal wall in left sidelying and to obtain a ZOA, she began to integrate that control with combined muscular efforts culminating in left acetabular femoral internal rotation as with *Left Sidelying Left Flexed Femoral Acetabular Adduction with Right Lowered Extended Femoral Acetabular Abduction* (see **Figure 17**). JP was severely challenged with kinesthetic awareness of muscle activation and "carry over" to alternative postures. In her case, it was very helpful to have her stand up after a left sidelying activity to try to reproduce the same movement pattern in upright—her most challenging posture. Adding activities like *Standing Supported Left Acetabular Femoral Internal Rotation with Right Femoral Acetabular Abduction* (see **Figure 19**)

*Transverse and alternating, reciprocating movement*: As JP demonstrated further capacity for trunk control with left acetabular femoral internal rotation, we added challenges to coordinate with right trunk rotation as with gait. The use of walking poles was tremendously helpful for this patient to help with her balance, core muscle activation, kinesthetic sense of the ground and weight shifting, as well as to offer additional support for spinal elongation, a critical element in scoliosis treatment. Activities depicted like Four Point Gait with Mediastinal

*Summary*: Over the course of her last few visits (21 visits total), JP was consistently reporting dramatic and steady improvement in her function. She was playing with her grandson more than 2 hours at a time and able to stand through 3-hour choir rehearsals. Her walking progression was up to 34 min. The last RMDQ score was 3/24 or 12.5% self-report disability. All physical therapy goals were met. She was highly compliant and motivated throughout the

The theoretical framework of PRI and its model of innate human asymmetry provides the clinician valuable insight into the development and progression of scoliosis and other spinal dysfunctions. This framework has the potential to redefine how clinicians evaluate and treat

ing indicated adequate sagittal plane control, she moved to a left sidelying program.

were, therefore, quite a good challenge for improved upright control.

course of her care, which no doubt, contributed to her strong outcomes.

Expansion were further developed (see **Figure 20**).

**6. Conclusion**

these conditions.

report disability.

*5.3.2. Treatment progression and clinical reasoning*

162 Innovations in Spinal Deformities and Postural Disorders

We are grateful to Ron Hruska MPA, PT, executive director of the Postural Restoration Institute, who formulated these concepts, developed this framework and continues to share his evolving insights.