**6. Discussion**

*Plant Communities and Their Environment*

**% EPI coverage in an area)**

Field: HEA pipe with cap and herbaceous plants

Field: HEA and

Forest: HEA and herbaceous plants

Forest: hydrocarbon seep and herbaceous plants

trees

Forest: hydrocarbon seep and trees

EPI

Forest: hydrocarbon seep and EPI

Forest: HEA and

Forest: HEA and

EPI

Field: groundwater seep and EPI

**Setting Upslope 5–10 m from HEA**

No response with diverse plant community (<5%)

EPI absent or rare (<5%)

EPI absent or rare (<5%)

No response with diverse community (<5%)

No response with diverse community (<5%)

No response with diverse community (<5%)

No response with diverse community (>5%)

EPI absent or rare (<5%)

EPI absent or rare (<5%)

*attributable to brine that contains elevated concentrations of a suite of elements.*

Information on the herbaceous and woody plant communities along with the distribution of EPI observed within forests and fields at sites A to L at WUT allowed for the resolution of the spatial responses of plants to the presence of HEAs, natural hydrocarbon seep, and groundwater seep (**Table 5**). Species that show growth morphology via rhizome or vine seem to show an ability to occur within 5 m of HEAs, such as EPI, riverbank grape, and Virginia strawberry. Since these patterns were resolved across

**Response of plants and EPI relative to distance from HEA or natural groundwater seep (as approximate**

**1–5 m from HEA**

A few plant species evident, some EPI with most species absent (>90%)

EPI dominant (>90%)

EPI dominant (>95%)

A few plant specimens with EPI dominant (>95%)

No plants in path of seepage; EPI evident on edge of drainage

Trees dead; other trees stunted with dead branches near HEAs with dominant EPI (>90%)

Sensitive trees absent from path of groundwater. Tree branches dead along path. Other trees stunted in height

EPI dominant (>95%)

EPI dominant (>95%) along edge of path of groundwater; no EPI in path

**0 m from HEA or seep**

No plants

No EPI; no plants

No plants

No plants

No trees

No trees

No EPI and no plants

No EPI

EPI dominant (>95%)

**or seep**

**or seep**

(<5%)

(<5%)

(25–95%)

Diverse plant community (< 5%)

EPI absent or rare

EPI absent or rare

Loss of diversity, shorter plants within drainage path

No plants in drainage path of seepage to Lake Huron

Sensitive trees absent; tree branches on side of HEA dead; other trees stunted in height

EPI dominant, usually >50% of specimens

EPI dominant (>95%) along edge of path of groundwater; no EPI

*Findings from this study demonstrate the plant communities respond to the HEA and seeps based on water drainage,*

in path

*Summary of response patterns for vegetation found in association with hydrocarbon extraction area, groundwater seep in a field, and hydrocarbon seep in a forest setting, represented as approximate % coverage of*

Sensitive trees absent from path of groundwater. Tree branches dead along drainage path. Other trees stunted in height

**126**

**Table 5.**

*EPI in an area.*

Wiikwemkoong Unceded Territory history identifies the community-associated HEAs with disturbed land, and this led to the expulsion of oil men during 1905 [21, 31]. Such identification of disturbance was attributed to the construction of infrastructure like roads as well as clearing of forest in addition to using valuable farmland for HEAs. Community members also described the presence of large barrels used to separate oil from water in fields and forests [21]. The oil men would direct the oil-water slurry through pipes to these barrels. When the decision was made to evict the oil men, the HEAs were burned, and this common disturbance history contributed to the responses of herbaceous and woody plants described in this study. Oral history also identifies that these burned areas were considered scars on Mother Earth that were very slow to recover. However, this recovery of the HEAs was inferred to be slower than expected and resulted in different plants at these sites compared with adjacent areas [21]. Since 109 years passed from the time the HEAs were burned until the initial assessments during 2014, this represents a unique opportunity for learning, to understand how the herbaceous and woody plants responded to this common disturbance history [17]. This understanding arises from un-replicated activity associated with large-scale disturbance of fields and forests at WUT due to the development of HEAs. Such activities represent an opportunity for learning that is consistent to Carpenter's [17] recommendation to consider ecological settings to quantify interactions involving species and document responses of plants and animals to large-scale environmental perturbations. Carpenter [17] recommended that such perturbations, if studied, often provide the chance to document nonrandom change; a reasonable way to interpret such change is with causal inference. In an earlier study [18], a similar idea was expressed about severe perturbations representing a chance to document response of plants and animals but provided the caveat that such events possibly generate unique responses that are difficult to quantify and apply to other settings. Using this documentation of the response of herbaceous and woody plants near HEAs, it pointed to the use of EPI as a bioindicator of the plant community responses to brine as a way to find HEAs. At WUT, it is useful to use EPI as a bioindicator, as it is the only species consistently found within 1 m of HEAs. Other species, such as Virginia strawberry, also show distributions near HEAs, likely attributable to growth morphology via vine. Due to the wide distribution and salinity tolerance of EPI, it is probable this species could be evaluated for use to resolve the response of plants to HEAs beyond WUT.

This study reports the observed responses of herbaceous and woody species to episodic exposure to brine in a setting with a common disturbance history. These observations at WUT identified a pattern of reduced diversity of herbaceous and woody species as well as increased coverage of EPI in proximity to drainage from HEAs and natural seeps in fields, and FOD8-1 and FOC4-3 woodlands. These plant communities demonstrate a spatial response to water that originates from HEAs and natural seeps with rapid transition from diverse plant community to dominance by EPI over short distances despite similar exposure to sunlight and a common disturbance history. The identification of this response pattern involving a reduction of plant diversity and dieback of overstory tree branches was directly attributable to brine found near HEAs and seepage in fields and forests, representing an ecotone

that defines the zone of disturbance. Observations from site C during September 2017 demonstrated that chlorosis will start within a few days of the arrival of brine; at this site, the brine is able to travel an extended distance from the source, due to the topography, causing stress and death to plants all along the drainage path. Site G demonstrated the response of herbaceous and woody species that reflects natural seepage of hydrocarbons and brine with similar patterns of species selection leading to nearly full coverage of the area by EPI. In contrast, the capped well at site I showed evidence of very little disturbance at 5 m and the focal presence of EPI directly around the pipe. Species such as Virginia strawberry and multiflora rose that grow with vines appear alongside EPI. Long-term responses include herbaceous plant communities essentially absent in close proximity to HEAs and natural seeps as well as an overstory tree canopy dominated by species somewhat tolerant to salt with dead branches near the source of brine.

Other observations from HEAs identified additional plant associations within these areas. Specifically, all HEAs include a few very mature common buckthorn (*Rhamnus cathartica* L.) and/or glossy buckthorn (*Rhamnus frangula* Mill.). It is inferred the seeds of these nonindigenous buckthorn were accidentally introduced to WUT during the 1800s via transport on equipment used for HEAs [21]. Inspections always reveal that buckthorn has spread extensively outward, in a radial pattern, from each of the HEAs. Hence, when buckthorn is found at WUT, surveys will follow these nonindigenous trees, to see if they lead to large specimens in proximity to an HEA. Another consistent observation is that one apple tree (often *Malus domestica* Borkh.) was always planted upslope from each of the HEAs. Further, in a field with numerous HEAs represented as metal pipes, one apple tree is located upslope and within 10 m of each pipe [21]. Oral history from WUT revealed the oil men regarded an apple tree as good luck and a source of food during the autumn season. At WUT, the presence of a large (>30 cm DBH) apple tree in close association with buckthorn is now used as preliminary indicators of possible presence of HEAs in an area.

Studies at WUT [21] documented soil at HEAs containing elevated hydrocarbon concentrations, especially for soil in contact with wood from the former facilities, whereas soil concentrations of hydrocarbons rapidly declined with distance from HEAs, attributed to bacterial degradation of the hydrocarbons over time [21]. These low concentrations of soil hydrocarbons downslope from HEAs provide additional evidence that it is brine from the HEAs that plants are responding to in these areas. The response pattern of the plants, including EPI, to brine at WUT forms the framework, as represented in **Table 5**, as a guide to find lost HEAs as well as understand influence of brine from natural seeps on plant communities.

A literature review documented a range of responses of herbaceous and woody species to brine from HEAs, but none was found for water arising directly from oil shale formations. The study in Oklahoma, USA, for plants downslope of HEAs attributed responses to the brine from the HEAs [6]. A separate study reported that herbaceous and woody plants recovered initially from a brine leak at an impoundment within 1 year after the leak was stopped with no soil treatments; plant community recovery was attributed to frequent rain washing the brine away [15]. At the site of this brine leak [16], the plant community 4 years later was populated by a diversity of herbaceous and woody species, attributed to the seed bank and live adjacent vegetation [15, 16]. Another study reported treatments for bare soils within 1 m deep former reserve pits used to store drill cuttings, drilling fluid, and brine, as preparation for replanting [12]. This bare earth was disked, mulch added, irrigated, and then seeded with local range grasses as well as planted seedlings. Success of seed germination and seedling survival was higher on mulch-treated soils than untreated soils. Over time, the mulch-treated soils showed declines in the

**129**

30 km2

*Eastern Poison Ivy (*Toxicodendron radicans *L.): A Bioindicator of Natural and Anthropogenic…*

seeded and planted species due to colonization by other local species. This mulch treatment led to the identification that establishment of salt-tolerant plants in the reserve pits following treatment can act as the basis for future plant establishment and reclamation; without treatment, seeding, and/or planting of seedlings, the pits require extended periods before plants naturally establish on these soils. Another study recommended the use of local, native plant species for seeding on land

disturbed by hydrocarbon extraction activities, with emphasis on species adapted to the soils associated with the area that often show elevated tolerance to soil salinity [38]. Such seeding recommendations included the use of local sources, due to likely adaptations to regional climate and soils, as the process of reestablishing vegetation on sites disturbed by HEAs is challenging due to the chemistry as well as other physical factors, such as soil compaction [3, 6, 32]. As a means to address challenges for seeding and planting on high-salinity soils, computer software was recently

Other areas of study are warranted, to resolve the morphological and physiological response of herbaceous and woody species associated with HEAs and natural seeps, based on observations at WUT. For example, anecdotal observations indicated a trend that herbaceous species near HEAs often had fewer and smaller flowers compared with specimens in adjacent areas. Other plants showed differences in height and leaf size in proximity to HEAs. This study did not provide for the opportunity to quantify the range of possible responses of plants to exposure to brine arising from HEAs. If the source of stress on these plants was not known, the differences in flowering, plant height, leaf size, etc. could be documented as a phenological response to regional factors, not local responses to brine exposure. Such opportunities for documentation of response of plants, including separation of cause between stresses in proximity to HEAs, may be useful in the future. The HEAs may also be resulting in genotypic changes to plants, due to long-term episodic exposure to brine. Plants like prairie smoke (*Geum triflorum* Pursh) have been observed periodically at WUT in close proximity to HEAs, whereas the USDA identifies this plant as having no tolerance to soil salinity. It may be interesting to resolve if prairie smoke has developed tolerance to elevated soil salinity at WUT. Responses of aquatic plants to brine exposure represent another understudied topic. At site F, the brine-oil slurry drained downslope to the shoreline of Smith's Bay. In the area of the shoreline, white residue was evident on the rocks on the shoreline and in the water. This area also lacked SAV, while adjacent areas demonstrated SAV among the rocks. These varied themes represent candidate areas for further study, to resolve the range of apparent responses of plants relative to episodic environmental stress from brine arising from HEAs and separate them from phenological responses to

This study resolved the response of plant communities to a common disturbance history as well as the episodic release of brine from HEAs and seeps within about

. The resolution of the response of herbaceous and woody species and EPI to HEAs and natural seeps represents a framework that could be applied elsewhere, to assess the intensity of disturbance as well as to find lost HEAs. The ecotone of disturbance at WUT for HEAs is defined by the brine drainage area within a local area of subsidence where EPI is able to dominate the herbaceous plant community. It is probable EPI is able to achieve dominance in these areas due to growth via rhizome and can ameliorate the extreme chemical concentrations in brine. Another consideration at WUT is the native plant community contains very few species tolerant of elevated soil salinity [25] and led to the opportunity for EPI to dominate areas with HEAs. This study has confirmed the distribution of EPI is useful to represent contemporaneous disturbances to herbaceous and woody species attributable to HEAs and natural seeps in forests and fields and applicable to other areas with HEAs.

*DOI: http://dx.doi.org/10.5772/intechopen.88150*

presented to guide such activities [39].

regional processes like climate.

*Eastern Poison Ivy (*Toxicodendron radicans *L.): A Bioindicator of Natural and Anthropogenic… DOI: http://dx.doi.org/10.5772/intechopen.88150*

seeded and planted species due to colonization by other local species. This mulch treatment led to the identification that establishment of salt-tolerant plants in the reserve pits following treatment can act as the basis for future plant establishment and reclamation; without treatment, seeding, and/or planting of seedlings, the pits require extended periods before plants naturally establish on these soils. Another study recommended the use of local, native plant species for seeding on land disturbed by hydrocarbon extraction activities, with emphasis on species adapted to the soils associated with the area that often show elevated tolerance to soil salinity [38]. Such seeding recommendations included the use of local sources, due to likely adaptations to regional climate and soils, as the process of reestablishing vegetation on sites disturbed by HEAs is challenging due to the chemistry as well as other physical factors, such as soil compaction [3, 6, 32]. As a means to address challenges for seeding and planting on high-salinity soils, computer software was recently presented to guide such activities [39].

Other areas of study are warranted, to resolve the morphological and physiological response of herbaceous and woody species associated with HEAs and natural seeps, based on observations at WUT. For example, anecdotal observations indicated a trend that herbaceous species near HEAs often had fewer and smaller flowers compared with specimens in adjacent areas. Other plants showed differences in height and leaf size in proximity to HEAs. This study did not provide for the opportunity to quantify the range of possible responses of plants to exposure to brine arising from HEAs. If the source of stress on these plants was not known, the differences in flowering, plant height, leaf size, etc. could be documented as a phenological response to regional factors, not local responses to brine exposure. Such opportunities for documentation of response of plants, including separation of cause between stresses in proximity to HEAs, may be useful in the future. The HEAs may also be resulting in genotypic changes to plants, due to long-term episodic exposure to brine. Plants like prairie smoke (*Geum triflorum* Pursh) have been observed periodically at WUT in close proximity to HEAs, whereas the USDA identifies this plant as having no tolerance to soil salinity. It may be interesting to resolve if prairie smoke has developed tolerance to elevated soil salinity at WUT. Responses of aquatic plants to brine exposure represent another understudied topic. At site F, the brine-oil slurry drained downslope to the shoreline of Smith's Bay. In the area of the shoreline, white residue was evident on the rocks on the shoreline and in the water. This area also lacked SAV, while adjacent areas demonstrated SAV among the rocks. These varied themes represent candidate areas for further study, to resolve the range of apparent responses of plants relative to episodic environmental stress from brine arising from HEAs and separate them from phenological responses to regional processes like climate.

This study resolved the response of plant communities to a common disturbance history as well as the episodic release of brine from HEAs and seeps within about 30 km2 . The resolution of the response of herbaceous and woody species and EPI to HEAs and natural seeps represents a framework that could be applied elsewhere, to assess the intensity of disturbance as well as to find lost HEAs. The ecotone of disturbance at WUT for HEAs is defined by the brine drainage area within a local area of subsidence where EPI is able to dominate the herbaceous plant community. It is probable EPI is able to achieve dominance in these areas due to growth via rhizome and can ameliorate the extreme chemical concentrations in brine. Another consideration at WUT is the native plant community contains very few species tolerant of elevated soil salinity [25] and led to the opportunity for EPI to dominate areas with HEAs. This study has confirmed the distribution of EPI is useful to represent contemporaneous disturbances to herbaceous and woody species attributable to HEAs and natural seeps in forests and fields and applicable to other areas with HEAs.

*Plant Communities and Their Environment*

with dead branches near the source of brine.

that defines the zone of disturbance. Observations from site C during September 2017 demonstrated that chlorosis will start within a few days of the arrival of brine; at this site, the brine is able to travel an extended distance from the source, due to the topography, causing stress and death to plants all along the drainage path. Site G demonstrated the response of herbaceous and woody species that reflects natural seepage of hydrocarbons and brine with similar patterns of species selection leading to nearly full coverage of the area by EPI. In contrast, the capped well at site I showed evidence of very little disturbance at 5 m and the focal presence of EPI directly around the pipe. Species such as Virginia strawberry and multiflora rose that grow with vines appear alongside EPI. Long-term responses include herbaceous plant communities essentially absent in close proximity to HEAs and natural seeps as well as an overstory tree canopy dominated by species somewhat tolerant to salt

Other observations from HEAs identified additional plant associations within these areas. Specifically, all HEAs include a few very mature common buckthorn (*Rhamnus cathartica* L.) and/or glossy buckthorn (*Rhamnus frangula* Mill.). It is inferred the seeds of these nonindigenous buckthorn were accidentally introduced to WUT during the 1800s via transport on equipment used for HEAs [21]. Inspections always reveal that buckthorn has spread extensively outward, in a radial pattern, from each of the HEAs. Hence, when buckthorn is found at WUT, surveys will follow these nonindigenous trees, to see if they lead to large specimens in proximity to an HEA. Another consistent observation is that one apple tree (often *Malus domestica* Borkh.) was always planted upslope from each of the HEAs. Further, in a field with numerous HEAs represented as metal pipes, one apple tree is located upslope and within 10 m of each pipe [21]. Oral history from WUT revealed the oil men regarded an apple tree as good luck and a source of food during the autumn season. At WUT, the presence of a large (>30 cm DBH) apple tree in close association with buckthorn is now used as preliminary indicators of possible presence of

Studies at WUT [21] documented soil at HEAs containing elevated hydrocarbon concentrations, especially for soil in contact with wood from the former facilities, whereas soil concentrations of hydrocarbons rapidly declined with distance from HEAs, attributed to bacterial degradation of the hydrocarbons over time [21]. These low concentrations of soil hydrocarbons downslope from HEAs provide additional evidence that it is brine from the HEAs that plants are responding to in these areas. The response pattern of the plants, including EPI, to brine at WUT forms the framework, as represented in **Table 5**, as a guide to find lost HEAs as well as

A literature review documented a range of responses of herbaceous and woody species to brine from HEAs, but none was found for water arising directly from oil shale formations. The study in Oklahoma, USA, for plants downslope of HEAs attributed responses to the brine from the HEAs [6]. A separate study reported that herbaceous and woody plants recovered initially from a brine leak at an impoundment within 1 year after the leak was stopped with no soil treatments; plant community recovery was attributed to frequent rain washing the brine away [15]. At the site of this brine leak [16], the plant community 4 years later was populated by a diversity of herbaceous and woody species, attributed to the seed bank and live adjacent vegetation [15, 16]. Another study reported treatments for bare soils within 1 m deep former reserve pits used to store drill cuttings, drilling fluid, and brine, as preparation for replanting [12]. This bare earth was disked, mulch added, irrigated, and then seeded with local range grasses as well as planted seedlings. Success of seed germination and seedling survival was higher on mulch-treated soils than untreated soils. Over time, the mulch-treated soils showed declines in the

understand influence of brine from natural seeps on plant communities.

**128**

HEAs in an area.


**7. Conclusions**

Understanding the mechanisms leading to aberrant immune response and the severe neuro-inflammation in MS plays a relevant role in the development of new treatments directed to decrease pro-inflammatory cytokine production and to ameliorate the clinical symptoms, slowing the disease outcome and delaying or arresting the onset of the disabilities. In this review we have presented recent data in EAE mice and in MS patients, supporting the role of ACh in MS. The dysregulated ACh homeostasis in MS, suggest how its altered functions might represent an additional pathogenetic mechanism negatively influencing the cytokines production with consequent disease outcome.

Interestingly, using the EAE mice model, it has also been described as the alteration of ACh synthesis or degradation may impact on neuron function, contributing to the motor and cognitive disabilities characteristics of MS patients, also influencing the glia network, the differentiation and survival of the oligodendrocytes, and triggering the neuro-inflammation.

The relevant role played by ACh in this context, is supported by the evidence that modulating the cholinergic system activity or cholinergic receptor functions, the clinical disabilities, at least in mice, are significantly reduced. In fact, the altered balance of ACh also in cholinergic area of the brain or spinal cord of EAE mice (i.e., basal ganglia or spinal motoneuros), suggested that the decreased ACh levels may influence the MS motor disabilities both reducing the levels of the neurotransmitter in the cholinergic neurons and increasing the neuro-inflammation with consequent impact on myelin disruption and axonal conduction [63,76,77].

This aspect appears supported by additional studies performed with conventional drugs used in the treatment of MS, as INFβ or dimethyl fumarate [36,88], that demonstrate a significant amelioration of the cholinergic activity with a possible consequent reduction of the clinical symptoms-MS associated. Therefore, further studies will be necessary to evaluate the impact of different immune modulators on the cholinergic system activity both in the immune system and in the brain.

In conclusion, the data described in this review highlight as ACh and its receptors may be implicated in MS pathogenesis. However, further investigation on the genetic aspects and epigenetic modulation of cholinergic markers gene expression could significantly improve the knowledge about MS onset and progression as well as to contribute to identifying new possible therapeutic strategies.

**Author Contributions:** Conceptualization A.M.T., Original draft preparation, writing—review and editing V.G., G.M., M.R., A.M.T. All authors have read and agreed to the published version of the manuscript.

**Funding:** Supported by FISM—Fondazione Italiana Sclerosi Multipla (Project number 2009-R-29; 2013-R-25).

**Conflicts of Interest:** The authors declare there are no conflicts of interest.


Preface

This book is intended to provide a concise, yet comprehensive introduction to some common hip and ankle pathologies and their treatment. Newer concepts continue to evolve and to keep abreast with these one should have a sound basic knowledge of the subject.

Every attempt has been made to narrate the concepts in a simplified manner keeping the originality. Wherever possible illustrations have been used to help the reader to understand the subject. The target audience comprises orthopedic surgeons, either in practice or in training, as well as clinicians, radiologists, and physical therapists.

The text is divided into two sections with short chapters providing a broad overview of the anatomy, pathology, and treatment. Selected references are also provided without the claim of being exhaustive and with the aim of stimulating interest and discussion.

We hope that we have succeeded in providing a useful and practical tool for the identification of some hip and ankle pathologies, and we remain open to any suggestions and criticisms for improvement in the future.

> **Carlos Suarez-Ahedo** Hospital Medica Sur, Mexico City

**Anell Olivos-Meza** Instituto Nacional de Rehabilitación, Mexico

> **Arie M. Rijke** University of Virginia, USA

**1**

Section 1

Hip

Section 1 Hip

**3**

**Chapter 1**

**Abstract**

and Biomechanics

using Modified Harris Hip score.

**1. Introduction**

corona mortis, secondary congruence

*Sachin Kumar Sharma and Hemant Mathur*

Surgical Anatomy of Acetabulum

Both column acetabular fractures are challenging articular injuries. Majority of them are treated operatively. The concept of "secondary congruence" was introduced by Letournel. Despite this, biomechanical data on secondary congruence indicate that nonoperative treatment leads to an increase in peak pressures in the supra-acetabular region with the potential risk of developing posttraumatic degenerative osteoarthritis. Operative management is therefore justified. A cohort of 10 patients having both column (anterior and posterior) acetabular fractures managed using bicolumnar plating between Jan 2016 and Dec 2017 were enrolled in the study and were analyzed during follow-up period. Eighty percent of the patients had excellent to good result. Average postoperative score was 85.7. Assessment was done

**Keywords:** anterior and posterior column fracture, modified Harris Hip score,

Hip arthroscopy requires a thorough knowledge of acetabular and pelvic anatomy. Acetabular and pelvic anatomy is complex yet important for any procedure to be done on hip joint. The articular surface of acetabulum can be visualized as being supported between the limbs of an inverted "Y". These two limbs are considered anterior and posterior columns of acetabulum. On radiographic view, anterior column is represented by iliopectineal line and posterior column by ilioischial line. Discontinuity in any of these lines is considered fracture of anterior or posterior column. The external iliac and internal iliac arteries lie in close relation to these columns. An anomalous connection of these two arteries called circle of death or corona mortis should be identified and ligated properly as injury to this artery can lead to catastrophic results. Lumbar plexus and its various nerve roots traverses the lesser and greater sciatic notches and are vulnerable to injury in portal placement and various other hip surgeries. This chapter mainly focuses on various aspects of surgical anatomy of acetabulum and biomechanics relevant to hip arthroscopy in detail.

Treatment of acetabular fractures requires a deep understanding of pelvic anatomy. With advent of various minimally invasive approaches and fixation methods, knowledge of acetabular anatomy plays a pivotal role in treatment of displaced acetabular

**2. Surgical and applied anatomy of the acetabulum**


**7. Conclusions**

In this work, a flexible and low-cost piezoelectric diaphragm was applied for surface quality monitoring in grinding of ceramic materials. The PZT diaphragm was also compared to an AE sensor, which is widely used for monitoring in several machining fields. In addition, a new time-domain ROP metric, based on the short-time Fourier transform, was proposed with the objective of estimating the surface quality of the workpieces. Therefore, the following conclusions can be drawn from this work:

The use of the PZT diaphragm in the monitoring of the surface quality of ground ceramic components, together with time–frequency domain analysis techniques, is new, and there are several possibilities for future applications and studies. Future work can be performed with new signal analysis methods and grinding parameters. The use of neural networks of classification or even estimation can be studied further.

**Author Contributions:** Conceptualization, M.A.A.V. and P.R.A.; Data curation, P.O.J.; Formal analysis, F.A.A. and W.N.L.; Investigation, M.A.A.V. and P.O.J.; Methodology, F.A.A.; Supervision, P.R.A.; Writing—original draft, M.A.A.V.; Writing—review & editing, P.R.A., E.C.B., R.B.d.S., D.D. and A.A.

**Funding:** This research was funded by the São Paulo Research Foundation—FAPESP, grant number #2018/07292-0 and National Council for Scientific and Technological Development (CNPQ), under grant 306435/2017-9 for supporting this research work.

**Acknowledgments:** The authors are grateful to the São Paulo Research Foundation—FAPESP for the financial support.

**Conflicts of Interest:** The authors declare no conflict of interest.


**3.1 Human Fcγ receptors**

Human Fcγ receptors comprise a family of glycoproteins expressed on the membrane of immune cells [7, 8]. These receptors can bind to the various IgG subclasses with different affinities [7], and induce different cellular responses [6]. FcγR can be classified as activating receptors (FcγRI/CD64, FcγRIIa/CD32a, FcγRIIIa/CD16a, and FcγRIIIb/CD16b), and one inhibitory receptor (FcγRIIb/CD32b) [7, 9, 33, 34] (**Figure 3**).

FcγRI is a high affinity receptor, having three Ig-like extracellular domains. It binds mainly monomeric IgG [9]. In contrast, FcγRII and FcγRIII are low-affinity receptors, having two Ig-like extracellular domains. They bind only multimeric immune complexes [9, 35]. FcγRI is associated with a dimer of the common Fc receptor γ chain, which contains an immunoreceptor tyrosine-based activation motif (ITAM) sequence (**Figure 3**). The ITAM sequence is important for receptor signaling [36].

FcγRIIa contains its own ITAM within its cytoplasmic tail. In contrast, the inhibitory receptor FcγRIIb contains an immunoreceptor tyrosine-based inhibition

#### **Figure 3.**

*Human Fcγ receptors. Schematic illustration of human receptors for IgG. Fcγ receptors are shown relative to the cell membrane (brown line). The IgG-binding chain (α) is expressed together with their respective γ2 signaling subunits. FcγRI is a high affinity receptor, having three Ig-like extracellular domains. FcγRII and FcγRIII are low-affinity receptors, having two Ig-like extracellular domains. FcγRIIIb is expressed exclusively on neutrophils, and it is a glycosylphosphatidylinositol (GPI)-linked receptor missing a cytoplasmic tail. ITAM, immunoreceptor tyrosine-based activation motif with consensus sequence YxxI/Lx (6–12)YxxI/L [36] (green oval); ITIM, immunoreceptor tyrosine-based inhibitory motif with the consensus sequence I/V/L/SxYxxL/V [39] (red oval).*

#### *Neutrophils*

motif (ITIM) within its cytoplasmic tail (**Figure 3**). The FcγRIIb negatively regulates various cell functions including antibody production by the B cell [37], proliferation, degranulation, and phagocytosis in other leukocytes when it is crosslinked with activating FcγRs [38, 39]. Most leukocytes express both activating and inhibitory FcγRs, hence simultaneous cross-linking establishes a threshold for cell activation [40] that maintains a balanced immune response [41, 42].

FcγRIII has two isoforms: FcγRIIIa is a receptor with a transmembrane domain and a cytoplasmic tail, associated with an ITAM-containing homodimer of Fc receptor γ chains (**Figure 3**). It is expressed mainly on macrophages, natural killer (NK) cells, and dendritic cells [7, 8]. In contrast, FcγRIIIb is expressed exclusively on neutrophils and it is a glycosylphosphatidylinositol (GPI)-linked receptor missing a cytoplasmic tail. Also, no other subunits are known to associate with it (**Figure 3**). It is important to mention that human FcγRIIa and FcγRIIIb are exclusive receptors that are not found in other species [33, 43].


**Acknowledgements**

The authors would like to thank the School of Mathematics, University of Nairobi for providing a conducive environment to conduct this research.

**Author details**

**295**

Carolyne Ogutu\*,† and Antony Rono† University of Nairobi, Nairobi, Kenya

† These authors contributed equally.

provided the original work is properly cited.

\*Address all correspondence to<EMAIL_ADDRESS>
*On Modelling Extreme Damages from Natural Disasters in Kenya*

*DOI: http://dx.doi.org/10.5772/intechopen.94578*

© 2021 The Author(s). Licensee IntechOpen. 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,