**4. PN as a general system representation framework**

As pointed in the beginning of this work, Petri Nets has developed for the last fifty years to become a general schema for systems modeling.

**Figure 7.** Time diagram for the web user latency.

*V* = *vi* is a finite set of state values;

following.

of the gas station, the total time interval spent to serve one or nine users is the summation of

Timed Petri Nets 373

Thus, the complete process would be to elicit the requirements using UML diagrams including time diagrams - synthesize a Timed Petri Net from this model, and them perform the requirement analysis and final synthesis of a model for the problem. In fact, the final

Formally, the timelines are drawn according the behavior of *state variables*, defined in the

A timeline is the tracking of all changes in state value in a interval [0, *τ*) where *τ* is the observed time horizon. A timeline is said to be completely closed if the union of its not superposed values is exactly *τ*. In that case the transitions occur in deterministic time.

the not superposed time intervals required for each dependent action.

results for the example of the gas station were obtained following this approach.

Definition 15.[State Variables] A state variable is a triple (*V*, *T*, *D*) where:

*T* : *V* → *V* specify each atomic transition or change in value. *D* : *V* → **N** × **N** is the time duration for each state value.

In the previous section, we showed that a modeling discipline should be followed to achieve good results with Petri Nets formal representation, specially when time is an important variable to consider, either by deterministic time or using continuous dense time intervals. However, in the example above time does not appear explicitly at the beginning, since we started with the class diagram where there was no reference to duration time of the processes (supplying or payment). The problem them begins with a demand to a proper representation of time duration in UML that could later be transformed in a timed net.

To fit this demand UML 2.0 specification inserted an interaction diagram derived from the sequence diagram where time intervals or time duration are very important issues. Thus, once identified the actors and sub-systems in the model, their interaction could be viewed and modeled taking in account that it occurs during a running time where specific events can cause a change in the status of that interaction. Thus, the full relation can be described in what is called a state lifetime where several timelines show the evolution of the interacting components.

OMG (www.omg.org) shows a very appealing example of time diagram to model

In Figure 7 we can see a hierarchical superposition of levels and the action derived from the interaction between a user and a web system. Sub-systems invoked by this action and the time they spent to provide a proper action are explicitly depicted. As in the previous problem

**Figure 7.** Time diagram for the web user latency.

14 Will-be-set-by-IN-TECH

The introduction of deterministic time (transition) would add more detail about the process, with the characteristic time for processing the payment or to fill a car. An organized queue would fail (even if works quite fine in the model) since this time can be modified depending of the user or to unpredictable events during the payment or during the supply process. However if specific (and deterministic)intervals such as 3 min for the payment and 5 min for the filling of gas are stablished, the system could handle 9 drivers in 25 min with a waiting

More convincing examples can be found in business, manufacturing or computer networks. More challenge problems emerged in the spatial applications or satellite control, but what is important is that even deterministic time approach can be used to solve a diversified set of problems. However, it could be stressed that the timed approach should be supported for tools and environments that rely in a sound and complementary approach to Timed Nets including Time Petri Nets. The approach shown here, inserted in the GHENeSys environment is exactly one of this cases. Besides, GHENeSys is an implementation of a unified net, that

In the next section we go further in the discussion of using Petri Nets and specifically Timed Petri Nets to fit requirements that come in the new version of UML, which includes time

As pointed in the beginning of this work, Petri Nets has developed for the last fifty years to

In the previous section, we showed that a modeling discipline should be followed to achieve good results with Petri Nets formal representation, specially when time is an important variable to consider, either by deterministic time or using continuous dense time intervals. However, in the example above time does not appear explicitly at the beginning, since we started with the class diagram where there was no reference to duration time of the processes (supplying or payment). The problem them begins with a demand to a proper representation

To fit this demand UML 2.0 specification inserted an interaction diagram derived from the sequence diagram where time intervals or time duration are very important issues. Thus, once identified the actors and sub-systems in the model, their interaction could be viewed and modeled taking in account that it occurs during a running time where specific events can cause a change in the status of that interaction. Thus, the full relation can be described in what is called a state lifetime where several timelines show the evolution of the interacting

In Figure 7 we can see a hierarchical superposition of levels and the action derived from the interaction between a user and a web system. Sub-systems invoked by this action and the time they spent to provide a proper action are explicitly depicted. As in the previous problem

OMG (www.omg.org) shows a very appealing example of time diagram to model

time of at most 2 min for some drivers.

diagrams and timelines.

components.

follows the specifications in ISO/IEC 15909 standard.

become a general schema for systems modeling.

**4. PN as a general system representation framework**

of time duration in UML that could later be transformed in a timed net.

of the gas station, the total time interval spent to serve one or nine users is the summation of the not superposed time intervals required for each dependent action.

Thus, the complete process would be to elicit the requirements using UML diagrams including time diagrams - synthesize a Timed Petri Net from this model, and them perform the requirement analysis and final synthesis of a model for the problem. In fact, the final results for the example of the gas station were obtained following this approach.

Formally, the timelines are drawn according the behavior of *state variables*, defined in the following.

Definition 15.[State Variables] A state variable is a triple (*V*, *T*, *D*) where:

*V* = *vi* is a finite set of state values;

*T* : *V* → *V* specify each atomic transition or change in value.

*D* : *V* → **N** × **N** is the time duration for each state value.

A timeline is the tracking of all changes in state value in a interval [0, *τ*) where *τ* is the observed time horizon. A timeline is said to be completely closed if the union of its not superposed values is exactly *τ*. In that case the transitions occur in deterministic time.

If the transitions occur in a time interval [*tmin*, *tmax*] the timeline is said to be flexible. In this case we can represent the transition in a Timed Petri Net by an interval, as proposed in the first section. If we want to deal with deterministic time transition it is enough to make *tmin* = *tmax* and the same net framework could be used.

Timeline models can be very useful in some critical problem applications such as intelligent planning and scheduling. Some of those applications could be used in spatial projects [14]5. In other applications Petri Nets were used to perform requirements analysis including deterministic time, as in the one proposed by Vaquero et al.[40][41]. In that case the idea of solving real life planning problems starts with the elicitation and specification of requirements using UML, goes through the analysis of this requirements using Timed Petri Nets, synthesizes a model also in Petri Nets and finally uses a specific language, PDDL, to transfer the model to software planners which will provide the final result. Also, a modeling design environment were developed to perform this process[41][40].

**Figure 9.** Time diagram in the itSIMPLE system.

In conclusion it is important to remark that the evolution of Petri Nets towards a formal representation, capable to treat complex systems should be based in two basis: the extension to model timed systems; and the development of a unified net that includes all extensions besides the timed approach - hierarchy, gates, not controled elements, always respecting the recent published ISO/IEC standard and its next release to appear in 2013. This is the fundamental concepts to have new environments that could support a complementary treatment of timed systems, that is, that could deal with deterministic timed net as well as

Timed Petri Nets 375

Besides, it would be advisable that the same environment could deal, also in a complementary way, with classic P/T nets as well as with high level (HLPN) nets or even with simetric nets, which is also part of the ISO/IEC standard. The novelty would be to use a unified net system as a platform to reach the further challenge which would be the introduction of abstract nets. In what concerns the unified net to treat time intervals and dense time, we achieve a good point with the system GHENeSys where the present work focus most in the first part. However, in [17] a more detailed description of the state class algorithm is given and the basic concepts that lead to a modeling and simulation approach to dense time nets. Therefore the unification with timed PN is a promising result in the near future. Also the system GHENeSys

with time PN in the same environment. That is the focus of the present work.

**5. Conclusions**

**Figure 8.** Language structure in itSIMPLE 3.1

A specific state lifetime were developed to model and analyze the timelines for the agents and objects that would compose the plan, as shown in Figure 8.

Based on this time diagram Petri Nets could be synthesized to make the proper validation of the model. It is important to notice that there are a large number of approaches and tools that claim to perform a good analysis of models directly associated to a planer software with good results. However, most of this systems address only model problems which are well behaved and/or have a limited size and complexity. When the challenge is to model a large system, such as the space project mentioned before or a port to get and deliver petroleum, the challenge could be too big to be faced by these proposals.

Therefore the combination UML/Timed Petri Nets could be successful in the modeling of large and complex problems also in the planning area, with the possibility to be applied in practice to real systems.

5 See also the Mexar 2 Project and the use of intelligent software application in the link mexar.istc.cnr.it/mexar2.

**Figure 9.** Time diagram in the itSIMPLE system.


FRDM–K64F ARM Mbed Board

FRDM–K64F ARM mbed board (ARM mbed, Cambridge, UK) is an ultra-low-cost development platform designed by NXP in collaboration with ARM mbed [34]. FRDM–K64F ARM mbed board will be the base device of LoRa Node along with SX1272MB2xAS LoRa shield and temperature, humidity, light intensity and soil moisture sensors. The sensors are physically attached on it. The specification of a FRDM–K64F ARM mbed board is in Table 2.


**1. Introduction**

Our immune system has developed to fight against invaders. Pathogenic invaders are microorganisms including virus, bacteria, fungus and amoeba.

In species development, innate immune system appeared first, then after jowed fish acquired immune system developed. Once microorganisms infects in organs, cells belonging to innate immune system such as neutrophils and macrophages move to the site of infection. Microor‐ ganisms are sensed by pattern‐recognition receptors (PRRs) of the innate immune system including dendritic cells (DC).These cells phagocytize infectious agents and produce cytokines and chemokines, which induce tissue inflammation. In phagolysozome of DC, the proteins, which constitute the microorganisms, are degraded. These DC migrates to lymph node and present the microorganisms antigens to T cells, which are central of adaptive immune responses.

Similar to the eradication of pathogens, the inflammatory response is also crucial for tissue and wound repair and called sterile inflammation. Host‐derived non‐microbial stimuli are released following tissue injury or cell death. These endogenous molecules have been termed damage‐associated molecular patterns (DAMPs). DAMPs are normally present intracellular and are therefore hidden from recognition by the immune system. Once tissues are injured these molecules are released into the extracellular environment by dying cells and trigger inflammation under sterile conditions [1] (Figure 1).

© 2013 Isobe et al.; licensee InTech. This is an open access article 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. © 2013 Isobe et al.; licensee InTech. This is a paper 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.

> adhesion and recruitment. Within 30 min. neutrophils migrate to the site of wound, which phagocytize dead cells and cellular debris and clear tissue. Then neutrophils are themselves phagocytized by tissue macrophages.  Then M2 macrophages migrate from blood vessel to repair tissue. Neutrophils have specific cell surface antigens called, Gr‐1. In murine model of wound repair (Figure 2), we depleted neutrophils by anti‐GR‐1 antibody. Although in young mice the kinetics of wound healing was not different by the depletion of neutrophils, the depletion of neutrophils by anti‐Gr‐1 antibody dramatically delayed wound healing in aged mice [4]. Bone marrow has both matured neutrophils and macrophages. First, we found that in splenectom‐ ized mice, bone marrow, spleen and thymus injection accerated wound healing (Figure 3). We transplanted bone marrow cells from GFP mice (C57BL/6 background) to C57BL/6 mice. We found that bone marrow cells injection accelerated wound healing and GFP positive neutro‐ phils and macrophages migrated to the wound tissue. Because wound healing of aged mice is relatively inefficient, we transplanted young bone marrow cells to aged mice. We found that young bone marrow cells enhanced wound healing of aged mice [5, 6]. In case of microorgan‐ isms acquired immunity help to phagocytize invader. By microorganism's infections, immu‐ noglobulin specific for the microorganisms bind to the surface and induce phagocytosis mediated by Fc receptors.We examined whether B cells, which produce antibodies to damaged tissues, might be engaged in the process of wound healing. We found that wound healing in splenectomized nude mice was delayed and the transfer of B cells accelerated wound healing in splenectomized mice. Further we detected several autoantibodies binding to wounded tissues [7] (Fig.4). Advancing age gradually decreased the strength of IgG1 autoantibodies, which bind to wounded tissues, although the strength of IgM autoantibodies was relatively

Tissue Damage and Repair Caused by Immune System and Personalized Therapy of Failed Organs by Stem Cells 209

As a mucosal wound repair model we used dextran sulfate sodium (DSS). Colitis may result from DSS toxicity to colonic epithelial cells. DSS is commonly used in rodent models to chemically induce acute intestinal inflammation, and the DSS‐induced colitis is characterized by weight loss, bloody diarrhea, epithelial cell damage, and immune cell infiltration, as well as an increased production of inflammatory mediators including TNF‐α, IL‐6, IL‐12, and interferons. Colitis was induced by oral administration of DSS to two months old C57BL/6 mice at 2 % (w/v)in drinking water ad libitum forfive days followed by normal drinking water. By this schedule, mice almost completely recovered. Interestingly at recovery phase of DSS‐ induced colitis, we observed strong up‐regulation of innate immune cells having Gr1+

cell surface maker in spleen and bone marrow. Transplantation of splenic DSS‐derived

CD11b+ cells into DSS‐treated mice improved colitis and promoted efficient colonic mucosal healing [8] (Figure 5). Anti‐Gr‐1 antibody treatment worsened the DSS‐ administered colitis. These results indicate that Gr1+CD11b+ cells induced by DSS worked to repair colon

CD11b

stable by advancing age [5, 6].

wound healing and repair colitis [9].

**2.2. DSS‐induced colitis**

+

Gr1+

**Figure 1.** Damaged cells by various stimuli produce DAMPs, which activate tissue resident macrophages and dendritic cells. Activated innate cells produce pro-inflammatory cytokines.


**1. Introduction**

Damage caused by excessive, long-term sun exposure contributes to signs of ageing and is most readily recognizable on our external surface, the skin. The damaging effects of the sun are mainly caused by ultraviolet radiation (UVR) which, on earth, consists of UVA (320 to 400 nm) and UVB (280 to 320 nm). The third type of UV radiation, UVC, also called short‐ wave or ionizing radiation, is absorbed by gasses in our atmosphere, does not reach the earth's surface and does not normally contribute to photodamage of skin. Ozone is one of the gases that absorbs UVC – fortunately, since UVC's ionizing effects can significantly alter cellular structures and molecules. Although UVB and UVA radiation does not have enough energy to ionize atoms, it can alter chemical bonds in molecules, thus altering their structure and functions. Skin cells are particularly susceptible to alterations mediated principally by the creation of free radicals and oxidative stress and changes in DNA structure can result in constitutive expression of protocongenes and ultimately the development of cancerous skin lesions.

Through its changes of molecular structures, UV radiation causes a series of biochemical and structural changes in skin tissues. Some of these effects, such as the induction of vitamin D production, are actually very beneficial to skin health. Niels Ryberg Finsen, a Danish physician and scientist, was one of the first to show that light can be both beneficial and det‐ rimental to human skin and his works *Om Lysets Indvirkninger paa Huden* ("On the effects of light on the skin"), published in 1893 and *Om Anvendelse i Medicinen af koncentrerede kemiske Lysstraaler* ("The use of concentrated chemical light rays in medicine"), published in 1896 cre‐ ated the paradigm on which photoaging and photodamage research was based for the next fifty years. Finsen won the Nobel Prize in Physiology in 1903 for his work on phototherapy in which he showed that certain wavelengths of light (UV in particular) could treat *lupus*

© 2013 Kulka; licensee InTech. This is an open access article 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. © 2013 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.

*vulgaris*, cutaneous tuberculosis. However, UV radiation can also initiate some deleterious effects that fundamentally change the structure and function of the skin and its constituent components. In fact, it has been shown that repeated, excessive sun exposure can initiate and perpetuate an inflammatory response that, given time, causes breakdown of the skin's immunological functions.

This review will focus on the effects of sun exposure on the skin microenvironment – partic‐ ularly the structural proteins and immune cells that are key players in the skin's protective functions. There is sufficient evidence to suggest that photodamage is associated with a low level of chronic inflammation that ultimately breaks down the skin's structure and results in some of the manifestations of skin aging. Consequently, skin treatments that target these processes are primarily focused on rebuilding the skin's architecture and promoting its bio‐ chemical regeneration. While some treatments have been found to have some beneficial ef‐ fects to the underlying cellular immune systems regulating skin inflammation and regeneration, others may, in fact, be deleterious to these processes. In this review, I will dis‐ cuss some naturally-derived bioactive compounds and formulations that have been shown or are suggested to be effective at modulating the pathophysiological changes associated with photodamage and photoaging. Bioactive compounds that can address these immuno‐ logical changes are uniquely poised to not only reduce the damage associated with photo‐ damage but may ultimately improve the resiliency and protective nature of the skin surface.

### **2. Skin is a protective organ**

#### **2.1. The three layers of defense**

Healthy human skin is an important physical barrier to the environment and protects the body from a variety of insults. It is the largest human organ and comprises approximately 15 percent of a person's body weight and covers about 1.5 to 2.0 m2 of our surface area. Skin is mainly composed of water (70%), protein (25%) and lipids (2%) forming an effective barri‐ er to dehydration, pathogens and mechanical insults such as abrasion. In a mechanical sense, the main function of the skin is to serve as a protective barrier to keep good things in (water, nutrients and heat) and keep bad things out (pathogens, UV radiation, toxins).

In order to understand the essential functions of the skin, it is important to review the com‐ plexity of this large organ. The skin is composed of three main layers, the uppermost epider‐ mis, the lower dermis and the hypodermis (Fig. 1). Each of these layers is composed of a specific set of cells that perform an essential function in that layer. The epidermis contains keratinocytes, melanocytes and Langerhans cells which are critical for the structural and functional integrity of the epidermis. Keratinocytes are the major population of cells and originate in the bottom-most stem-cell pool in the stratum spinosum (Fig. 1). The epidermis itself is composed of five layers: stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum basale. The uppermost layer of the skin, the keratinous stra‐ tum corneum, renews itself every 3-5 weeks and is principally composed of dead keratino‐ cytes (see section below on keratinocytes for more detail). Keratinocytes have the capacity to renew themselves every 4 weeks but this process can be increased during injury or inflam‐ mation. The underlying dermis is a vascularized, connective tissue containing nerve end‐ ings, glands and lymphatic vessels and provides structural and nutritional support to the upper epidermal cells. The dermis is, in fact, the a mucopolysaccharide matrix composed of collagen and elastin fibers. In this layer, there is a great variety of cells including mast cells, fibroblasts, macrophages and Langerhans cells all of which contribute to the immune re‐ sponse observed in some skin pathologies such as atopic dermatitis. These cells also main‐ tain and regulate the essential healthy functions of skin such as repairing injury, preventing infection, regulating circulation, preventing dehydration and providing nutrition. Beneath the dermis is the superficial fascia, or hypodermis, which is comprised primarily of fat tis‐ sue.

*vulgaris*, cutaneous tuberculosis. However, UV radiation can also initiate some deleterious effects that fundamentally change the structure and function of the skin and its constituent components. In fact, it has been shown that repeated, excessive sun exposure can initiate and perpetuate an inflammatory response that, given time, causes breakdown of the skin's

256 Using Old Solutions to New Problems - Natural Drug Discovery in the 21st Century

This review will focus on the effects of sun exposure on the skin microenvironment – partic‐ ularly the structural proteins and immune cells that are key players in the skin's protective functions. There is sufficient evidence to suggest that photodamage is associated with a low level of chronic inflammation that ultimately breaks down the skin's structure and results in some of the manifestations of skin aging. Consequently, skin treatments that target these processes are primarily focused on rebuilding the skin's architecture and promoting its bio‐ chemical regeneration. While some treatments have been found to have some beneficial ef‐ fects to the underlying cellular immune systems regulating skin inflammation and regeneration, others may, in fact, be deleterious to these processes. In this review, I will dis‐ cuss some naturally-derived bioactive compounds and formulations that have been shown or are suggested to be effective at modulating the pathophysiological changes associated with photodamage and photoaging. Bioactive compounds that can address these immuno‐ logical changes are uniquely poised to not only reduce the damage associated with photo‐ damage but may ultimately improve the resiliency and protective nature of the skin surface.

Healthy human skin is an important physical barrier to the environment and protects the body from a variety of insults. It is the largest human organ and comprises approximately 15 percent of a person's body weight and covers about 1.5 to 2.0 m2 of our surface area. Skin is mainly composed of water (70%), protein (25%) and lipids (2%) forming an effective barri‐ er to dehydration, pathogens and mechanical insults such as abrasion. In a mechanical sense, the main function of the skin is to serve as a protective barrier to keep good things in (water, nutrients and heat) and keep bad things out (pathogens, UV radiation, toxins).

In order to understand the essential functions of the skin, it is important to review the com‐ plexity of this large organ. The skin is composed of three main layers, the uppermost epider‐ mis, the lower dermis and the hypodermis (Fig. 1). Each of these layers is composed of a specific set of cells that perform an essential function in that layer. The epidermis contains keratinocytes, melanocytes and Langerhans cells which are critical for the structural and functional integrity of the epidermis. Keratinocytes are the major population of cells and originate in the bottom-most stem-cell pool in the stratum spinosum (Fig. 1). The epidermis itself is composed of five layers: stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum basale. The uppermost layer of the skin, the keratinous stra‐ tum corneum, renews itself every 3-5 weeks and is principally composed of dead keratino‐ cytes (see section below on keratinocytes for more detail). Keratinocytes have the capacity to

immunological functions.

**2. Skin is a protective organ**

**2.1. The three layers of defense**

**Figure 1.** Structure of skin. Skin is comprised of three main layers as shown. The epidermis contains keratinocytes, mel‐ anocytes and Langerhans cells which are critical for the structural and functional integrity of the epidermis. The epi‐ dermis itself is composed of five layers: stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum basale. The strata granulosum, spinosum and basale all contain keratinocytes whereas the strata cor‐ neum and lucidum have only dead keratinized cells. The underlying dermis is a vascularized, connective tissue contain‐ ing nerve endings, glands and lymphatic vessels. Beneath the dermis is the superficial fascia, or hypodermis, which is comprised primarily of fat tissue.

#### **2.2. Melanin and melanogenesis — A protective response**

As a result of its optical properties, the stratum corneum scatters photons and reflects UV radiation, providing some degree of protection. However, a portion of UV radiation pene‐ trates this uppermost layer and can potentially damage the delicate structures beneath. Mel‐ anin plays an important role in the skin's function as a protective barrier by absorbing UV radiation and thus protecting the underlying cells from DNA damage. The word melanin comes from the Greek word *melan*, meaning black. Melanin is a polymeric pigment derived from tyrosine and, in humans, it is synthesized in two main forms: the brown/black eumela‐ nin and the cysteine-rich red/brown pheomelanin. The chemical structures of these two types of melanin are different resulting in different properties and functions (Fig. 2). Where‐ as eumelanin is composed of dihydroxyindole carboxylic acids, pheomelanin is a polymer of benxothiazine units. The carboxylic structure may account for pheomelanin's weak shield‐ ing capacity against ultraviolet radiation relative to eumelanin. In fact, pheomelanin has been shown to amplify UVA-induced reactive oxygen species (ROS)[1]. For this reason, pheomelanin is sometimes referred to as a UV-sensitizer and in some instances has been considered to have a weak carcinogenic effect in terms of melanoma formation.

**Figure 2.** Chemical structure of eumelanin and pheomelanin.

Melanogenesis refers to the biochemical process by which melanin is formed. Melanocytes are the principal cell type responsible for the production and distribution of melanin in the skin. Since melanocyte differentiation and proliferation is linked very closely with their abil‐ ity to produce melanin, melanogenesis is sometimes used to describe the process of melano‐ cyte viability and reproduction. Indeed, many cosmetic products on the market that profess to alter or manipulate melanogenesis are actually cytotoxic to melanocyte and by killing healthy melanocytes they indirectly decrease the amount of melanin in the human epider‐ mis. For example, hydroquinone (HQ), which is an U.S. Food and Drug Administration (FDA) -approved product, is used in 2 – 4 percent concentration as a skin-lightening agent but is considered to be cytotoxic to melanocytes[2]. Interestingly, some antibiotics used to treat ear infections, such as amikacin, are cytotoxic to melanocytes as well and one of its principal side-effects is ototoxicity[3].

anin plays an important role in the skin's function as a protective barrier by absorbing UV radiation and thus protecting the underlying cells from DNA damage. The word melanin comes from the Greek word *melan*, meaning black. Melanin is a polymeric pigment derived from tyrosine and, in humans, it is synthesized in two main forms: the brown/black eumela‐ nin and the cysteine-rich red/brown pheomelanin. The chemical structures of these two types of melanin are different resulting in different properties and functions (Fig. 2). Where‐ as eumelanin is composed of dihydroxyindole carboxylic acids, pheomelanin is a polymer of benxothiazine units. The carboxylic structure may account for pheomelanin's weak shield‐ ing capacity against ultraviolet radiation relative to eumelanin. In fact, pheomelanin has been shown to amplify UVA-induced reactive oxygen species (ROS)[1]. For this reason, pheomelanin is sometimes referred to as a UV-sensitizer and in some instances has been

258 Using Old Solutions to New Problems - Natural Drug Discovery in the 21st Century

considered to have a weak carcinogenic effect in terms of melanoma formation.

Melanogenesis refers to the biochemical process by which melanin is formed. Melanocytes are the principal cell type responsible for the production and distribution of melanin in the skin. Since melanocyte differentiation and proliferation is linked very closely with their abil‐ ity to produce melanin, melanogenesis is sometimes used to describe the process of melano‐ cyte viability and reproduction. Indeed, many cosmetic products on the market that profess to alter or manipulate melanogenesis are actually cytotoxic to melanocyte and by killing healthy melanocytes they indirectly decrease the amount of melanin in the human epider‐ mis. For example, hydroquinone (HQ), which is an U.S. Food and Drug Administration (FDA) -approved product, is used in 2 – 4 percent concentration as a skin-lightening agent but is considered to be cytotoxic to melanocytes[2]. Interestingly, some antibiotics used to

**Figure 2.** Chemical structure of eumelanin and pheomelanin.

One of the most obvious and controversial side-effects of exposing our skin to UV radiation is an increase in skin pigmentation. Certainly the issue of tanning and tanning beds has re‐ cently gained a great deal of attention because it has been shown that exposure to prolonged UV radiation (either from tanning beds or outside exposure) can cause melanoma and an effort is underway to limit the amount of time that people, especially children, spend tan‐ ning in any setting. The process of tanning is a protective mechanism and the skin's way of protecting its internal biochemical reactions from UV damage. Increased pigmentation is caused by increased production of melanin which is able to absorb some UV radiation and thus protect more sensitive biological pathways in the cell[4]. Epidemiological studies have shown that people who have high levels of constitutive pigment in their skin and are able to "tan well" are less likely to develop skin cancer[5], [6].

We still do not fully understand the precise mechanisms that initiate the malignancies asso‐ ciated with skin cancer and we certainly have an incomplete understanding of how photo‐ damage and repair functions in people of different skin colors. However, mouse models and human studies have shown that albinos have a lower incidence of melanoma than their fair skinned counterparts[7] suggesting that melanin cannot just function as a protective UV-en‐ ergy absorber. Recently, several groups have shown that melanin, especially pheomelanin (a yellow/red form of melanin), acts as a potent UVB photosensitizer to induce DNA damage and cause apoptosis in mouse skin. These groups believe that pheomelanin contributes to UV-induced DNA damage that is incompletely repaired. They further believe that this DNA damage maps to specific sequences of BRAF and N-RAS genes, both of which are frequently mutated in human melanoma[8], [9].

Some organic and inorganic compounds mimic the effects of melanin by absorbing or scat‐ tering UVR due to their particulate nature – often in the nanoscale. These chemicals are processed and made available as lotions, sprays, gels or other topical applications common‐ ly known as sunscreens. There are 17 different chemicals that have been approved by the U.S. FDA as active ingredients in sunscreens. Oxybenzone (benzopehone-3) is the most widely used sunscreen chemical worldwide but other chemicals include octinoxate, avoben‐ zone, and octyl salicylate. Some of the physical sunscreens are micro or nano-ionized to cre‐ ate particulate formulations capable of forming a protective UV barrier on the skin's surface. Titanium dioxide (TiO2) are often used as a inorganic protective sunscreens in cosmetic products and to adjust their protective factor (SPF), they are often coupled with organic chemicals such as p-amino benzoic acid (PABA) which absorbs UVB but not UVA radiation. Recently, some have suggested that these nanoparticles (NP; around 200 nm) may penetrate the skin and modify the skin's immune-environment. However, several groups have shown that although nanoparticles are unable to penetrate healthy, intact human epidermis[10] they can significantly disturb cell functions through direct contact when the skin barrier is compromised[11], [12]. In fact, NP can reach the epidermal layer via hair follicles in certain circumstances such as laser-treatment[13] or inflammation[14], [15] but most compounds, al‐ though targeting the follicular region, do not permeate past the pilosebaceous region[16].


*4.4. Piston Expanders*

In a piston expander, the working chamber is formed by the inner surface of the cylinder and the surface of the moving piston. The piston reciprocates in the cylinder between top and bottom dead position and is driven by the crank mechanism. Studies on the possible application of piston expanders in micro steam and ORC systems have proceeded for many years.

The results of research on application of a small piston expander in the ORC system utilizing R134a as a working fluid are reported in [178–180]. The tested expander was manufactured by StarEngine company. The expander features a total displacement of 230 cm3 and is hermetically coupled in one casing with a generator. The general view of this expander is presented in Figure 37.

**Figure 37.** StarEngine piston expander [178–180].

The experimental research on this expander was carried out for varied heat source and heat sink temperature. Heat source temperature was varied in the range 65–85 ◦C and the temperature of the heat sink was varied in the range 28–27 ◦C. The mass flow rate of the working fluid was varied between 0.05 and 0.14 kg/s, pressure in the evaporator was varied between 11 and 19 bar and pressure in the condenser was varied between 6 and 7 bar. For these experimental parameters, an electric power output of 250–1200 W was achieved while expander rotational speed was ranging between 320 and 1100 rpm. The total efficiency of the expander-generator unit was varying between 38 and 42%. The achieved gross efficiency of ORC system was 4.5% while the achieved net efficiency was 2.2%.

In [181] the results of experimental tests carried out on a prototype oil-free piston expander designed for application in steam distributed generation systems are reported. The electric power output of the tested expander ranges between 740 and 2400 W depending on the parameters of the working medium. During the experiments the thermal parameters of the working fluid at the inlet to the expander were varied in the range 260–340 ◦C and 20–34 bar. The experimentally achieved internal efficiency of the expander was varying between 19 and 40%. This type of steam expander is also promising for application in ORC systems [181]. In [182,183] the results of research on a piston expander featuring a power of 3 kW and applied in the ORC system are presented. The expander is a modified reciprocating compressor with a specially designed control valve.

In [184] the authors presented the results of modeling of the operation of a piston expander designed for application in waste heat recovery system from the passenger car exhaust gases. Modeling results showed the possibility of obtaining an expander power output of 7 kW and an isentropic efficiency between 55 and 70%.

In [185] the results of experimental research on a swash-plate piston expander featuring a displacement of 195 cm3, which was implemented in the ORC system using blowing agent R245fa as a working medium are presented. This type of expander uses a swash-plate to transmit torque from the pistons to the shaft. The cross-section of swash-plate expander is presented in Figure 38.

**Figure 38.** Cross-section of a swash-plate piston expander [185].

The tests of the expander were proceeded for gas inlet pressures ranging between 18 and 30 bar and the rotational speed of the expander ranging between 1000 and 4000 rpm. For these experimental conditions working fluid pressure at the outlet of the expander was ranging between 2.9 and 4.02 bar. The inlet pressure was regulated by changing the mass flow rate of the working fluid by means of a pump. Depending on the operational conditions working fluid was superheated in the range of 4–17 K and working fluid mass flow rate was varied between 29 and 105 g/s. The obtained mechanical power of the expander was ranging between 0.3 and 2 kW while the maximum achieved internal efficiency of the expander was 53%. The mechanical efficiency of the expander was ranging

between 50 and 85%. The results of research on swash-plate expanders were also reported in [186,187].

In addition to the piston expanders discussed above, linear piston expanders are also investigated to be applied in ORC systems. Research results on this type of expansion machines were reported in [188,189]. In a linear piston expander, the linear arrangement of the cylinders is applied. This design is similar to the boxer arrangement of cylinders, but does not use a crankshaft. A linear generator is placed between the cylinders. The piston rods of the opposing pistons are connected to each other by a piston rod of a linear generator. The kinetic energy of the reciprocating movement of the piston rod is converted into electricity in a linear generator. The cross-section of linear piston expander is presented in Figure 39. In [190] the test results and design guidelines for a linear piston expander that can be applied in a micro-power ORC systems used for waste heat recovery from automotive engines were presented.

**Figure 39.** Cross-section of a linear piston expander [190].

It has been reported [190] that incomplete expansion (pressure of the working medium in the cylinder after expansion is higher than the pressure of the working medium in the outlet channel from the expander), heat transfer, flow losses during filling and evacuation of the working fluid from cylinder, friction and leakages are the main phenomena limiting the efficiency of linear piston expanders. It has also been shown that appropriate valve control has a significant impact on the linear piston expander operation and pressure losses occurring on the valves. The results of the tests carried out on the prototype of the linear piston expander showed that for gas inlet pressures ranging between 0.13 and 0.21 MPa, the internal efficiency of the expander varies in the range 66.2–93% and decreases with increasing inlet pressure. The highest power output of 22.7 W was achieved for the gas inlet pressure of 0.2 MPa and internal efficiency of 66.2%.

Compared to the other types of volumetric expanders (such as e.g., lobe, screw and Wankel expanders), piston expanders are characterized by a much simpler design; however, they require lubrication, valve timing, and generate vibrations during operation.


**1. Introduction**

Implementing new tools for bioanalytics is the priority goal for the modern diagnostics and medicine. This task can be efficiently fulfilled only by merging the expertise from various research fields, that is materials and nanoscience, bio- and electrical engineering, chemistry. In this respect, a microfluidic concept that groups the tools and techniques to study and manipulate fluids at a submillimeter length scale, represents an ideal solution for micro- and nanosensors-based platforms. The field of microfluidics has shown the power of downscaling techniques for the manipulation and analysis of fluids [1]. High-throughput characterization of processes in such applications is a key task, particularly in medical diagnostics, food processing and pharmaceutical industries [2]. Although downscaling is in principle compatible with parallelization to increase the throughput, implementing a large number of experiments would require a dramatic scaling-up of the overall platform size. The solution to this issue is found in the droplet microfluidics technology. Here, immiscible phases are used to create discrete volumes of confined solutions, maintaining the small footprint of the employed device [3].

The generated emulsions can be counted even up to thousands per second [4]. With each single droplet being an independent miniaturized laboratory for biochemical experiments, this technology allows highly parallelized and controlled measurements, surpassing the precision of conventional assays. Other advantages benefit the droplet generation systems, such as enhanced mixing and mass transfer efficiency leading to faster reaction times [5] or minimized sample absorption on channel walls [6].

Since the first demonstration in 2001 [7], this novel bioanalytic approach has found a wide range of applications: generation of drug-loaded particles for therapeutic agent delivery [8], fabrication of micromotors [9], confinement of particles [10] creation of synthetic cells [11], microbubbles as ultrasound or photoacoustic contrast agents [12], diagnostics [12], microcapsules for cell culture [12], etc. In particular, the approach has proved itself effective in microbial cell assays for both fundamental microbiology research and clinical studies, *i.e.* to determine the metabolic activity, division rate, and drug resistance [13–15]. Although important contribution have been made, the technology remains a work in progress. Strong efforts are still invested in the development of droplet tracking and analytical techniques. Real-time detection and analysis of the droplets is critical to monitor the dynamics of the ongoing confined events. Additionally, real-time analysis enables a timely response to the needs by tuning the properties or the direction of the generated droplets as needed. A simple photography or video acquisition process could provide access to basic features such as droplet size, morphology, color, or rough monitoring of microscopic objects inside. Here, the processing power may impose a limitation to the amount of droplets per second that can be analyzed. Implementing alternative transduction mechanisms could offer a much simpler setup with faster sampling rate. It could also give access to information on the nature of the droplet content, which cannot be easily obtained from an image.

Here, we provide an overview of the existing approaches for the real-time tracking of droplets in multiphase microfluidic devices. We make a distinction between optical and optics-less techniques, with electrical or electrochemical and magnetic techniques as part of the second group, which can find droplet properties that remain more hidden to the eye. While there are additional techniques already demonstrated such as mass spectrometry [16] or electrospray ionization mass spectrometry [17], we put the focus on the former two groups of techniques as more advantageous ones in terms of miniaturization possibilities in the spirit of the lab-on-a-chip purposes.


**1. Introduction**

340 Holograms – Recording Materials and Applications

Yang H-G.; & Kim E-S. (1996). Practical Image Encryption Sscheme by Real-Valued Data,"

Recently, Italy's National Committee for Cultural Heritage found some microscopic codes in Mona Lisa's pupils by using a magnifying glass (Lorenzi, 2010). Experts have pointed out that the codes may represent several messages, including the initials of Leonardo Da Vinci, "*LV"*. On the other hand, how and why such microscopic messages were embedded in her pupils has not been revealed yet. The most interesting part of this *other Da Vinci code* is that, although techniques for microscopic fabrication and retrieval had not been generally established in the early 16th century, the concept of embedding secret messages in a macro-scale view already existed—or as we now say, "The best place to hide a leaf is in a forest".

Present-day techniques for realizing this concept involve the ideas of *covertness* and *overtness*. The former means not showing something openly, and the latter means the opposite. As Da Vinci showed 500 years ago in Mona Lisa's pupils, microscopic optical techniques are suitable for embedding secret messages in a macro-scale optical observation, because the hierarchical structure inherent between different levels of the optical scale can be implemented simply, and the levels are functionally independent of each other. For instance, confidential information can be hidden in any of the physical attributes of light, such as phase, wavelength, spatial frequency, or polarization, so that one kind of anti-counterfeiting is represented (Javidi et al., 1994; Refregier et al., 1995; Rakuljic et al., 1992).

Holography, which generates natural three-dimensional images consisting of a number of diffracted light beams, is one of the most common anti-counterfeiting optical techniques (Renesse et al., 1998). In the case of a volume hologram, the surface of the hologram is ingeniously designed into a complicated structure that diffracts incident light in specific directions. A number of diffracted light beams can form an arbitrary three-dimensional image. Because these structures are generally recognized as being difficult to duplicate,

\* Makoto Naruse1,2, Takashi Yatsui1, Tadashi Kawazoe1, Morihisa Hoga3, Yasuyuki Ohyagi3,

Yoko Sekine3, Tokuhiro Fukuyama3, Mitsuru Kitamura3 and Motoichi Ohtsu1

*1The University of Tokyo,Japan*

*2National Institute of Information and Communications Technology, Japan*

*3Dai Nippon Printing Co. Ltd., Japan*

Nanophotonic Hierarchical Holograms:

innovations can be achieved.

is mass-producable.

**3.1 Concept**

**2.2 Hierarchy based on nanophotonics**

device in the form of a *nanophotonic hierarchical system* (Fig. 2).

**3. Nanophotonic hierarchical hologram**

Demonstration of Hierarchical Applications Based on Nanophotonics 343

Fig. 1. (a) Generation of optical near-fields, and (b) development of nanophotonics. Because optical near-fields do not involve the optical diffraction limit and they exhibit characteristic features that depend on direct interaction with materials, both *quantitative* and *qualitative*

Hierarchy in optical near-fields is one of the most appealing attributes for making innovative devices and systems based on nanophotonics. Naruse et al. investigated the hierarchy within the scale of optical near-fields, whose distribution is represented by a Yukawa function (Ohtsu et al., 2008), by investigating the size of materials and their associated optical near-fields (Naruse et al., 2005). The optical near-field response at a given scale is the result of interactions between the retrieval probe and the nanometric materials, and it is correlated with the materials involved at that scale. This feature has been exploited in various applications, for example, hierarchical optical memories where shape-engineered nanostructures provide twolayer responses in optical near-fields (Naruse et al., 2008). Moreover, besides the sizes of the materials, the shape, alignment, and composition are also important physical properties for engineering hierarchical systems. By suitable arrangement of such properties, several characteristic distributions of optical near-fields can be revealed (Naruse et al., 2008; Tate et al., APB2009; Tate et al., OptExp2009). These characteristics exert a large influence on the retrieval, and it means that various retrieval layers can be independently implemented in the same

From the point of view of the optical security, each layer is defined as an independent information layer. This enables a security layer structure in which nano-scale layers implement covertness and macro-scale layers implement overtness. The former is technically difficult to access and is non-duplicatable, whereas the latter is easy to access and

We can see the hierarchy of optical near-fields and far-fields because optical near-field interactions are distinguishable with propagating light. This characteristic feature has led to hierarchical optical system designs, such as *nanophotonic hierarchical holograms* (Tate et al., 2008), where independent functions are associated with both optical near- and far-fields in

the same device. Figure 3 shows the basic concept of the hierarchical hologram.

holograms have been widely used in the anti-counterfeiting of bills, credit cards, etc. However, conventional anti-counterfeiting methods based on the physical appearance of holograms are less than 100% secure (McGrew et al., 1990). Although they provide ease of authentication, adding another security feature without causing any deterioration in the appearance is quite difficult.

Many existing optical devices and systems, not just holography, operate based on the phenomena of *propagating* light. Therefore, their performance is generally limited by the diffraction of light (Zhdanov et al., 1998). The critical difficulty in improving the function of conventional holograms is that they are also bounded by the diffraction limit. However, with recent advances in nanophotonics, especially in systems utilizing optical near-field interactions, several optical devices and systems can be designed at densities beyond those conventionally constrained by the diffraction limit (Ohtsu et al., 2008). Because several physical parameters of propagating light are not affected by nanometric structures, the conventional optical responses in the optical far-field are not affected by these structures either. Essentially, this means that another functional layer in the optical near-field regime can be added to conventional optical devices and systems without any effect on their primary quality, such as reflectance, absorptance, refractive index, or diffraction efficiency.

Here, we propose a *nanophotonic hierarchical hologram* as a typical demonstration of this concept. The nanophotonic hierarchical hologram is a functionally improved version of a conventional hologram that works in both the optical far- and near-fields (Tate et al., 2008). Moreover, a *nanophotonic code*, which is physically a subwavelength-scale shape-engineered metal nanostructure, is embedded in the hierarchical hologram to implement a near-mode function (Tate et al., 2010). In this chapter, the basic concept of the nanophotonic hierarchical hologram with embedded nanophotonic codes and the fabrication of a sample device are described. In particular, since the proposed approach involves embedding a nanophotonic code *within* the patterns of the hologram, which is basically composed of one-dimensional grating structures, clear polarization dependence is found compared with the case where it is not embedded within a hologram or an arrayed structure. There are also other benefits with the proposed approach: a major benefit is that the existing industrial facilities and fabrication technologies that have been developed for conventional holograms can be fully utilized, yet allowing novel functionalities to be added to the hologram.


**Tobias Haller 1,\*, Fabian Käser 1 and Mariah Ngutu 2**

Received: 27 May 2020; Accepted: 29 June 2020; Published: 8 July 2020

### **1. Introduction**

This Special Issue contributes to the debate that land grabbing should be discussed as commons grabbing. But it also goes a step further. It poses this question: does commons grabbing also removes local people's capacity for resilience in the Global South, especially in Africa and if so how does that process unfold? The contributions share a focus on how the development of state institutions (formal laws and regulations for agrarian development and compensation) and voluntary corporate social responsibility (CSR) initiatives by investors have enabled the grabbing process of not just removing land but land and land-related common-pool resources formally previously governed by local common property institutions. The papers look at how state institutions (specifically state property of resources and their subsequent privatization) and CSR programs are used for development strategies by state actors and companies to legitimate their investments (Anseeuw et al 2012 [1], Lavers 2012 [2], Schoeneveld and Zoomers 2015 [3]).

Furthermore, the contributions in this Special Issue analyze the embedding of these strategies into neoliberal ideology of economic development (Escobar 1995 [4], Haller 2013 [5]). This ideology defines development as an economic progress of individual efforts adapted to the market to eradicate poverty and promote individual development. Such a view negates processes of power asymmetries and calls for remedies that are often externally defined. In addition, these remedies are often based on notions of private property and economic achievements with low level but nevertheless existing state interference (see Fletcher 2010 [6]). Therefore, state actors still profit from these policies, often without involving local actors and groups apart from local elites. State actors and investors also promote ideologies of modernity based on discourses of market-oriented economic development including green development based on the Sustainable Development Goals (SDGs) (see Haller et al 2018 [7], Haller et al 2019 [8]).

In order shed more light on these dynamics, this Special Issue proposes to take a fresh look at James Ferguson's *Anti-Politics Machines* (1994 [9], 2006 [10]) that serves to uncover the hidden power asymmetries of actors and political basis of state-driven development strategies in the age of neoliberalism. The papers therefore analyze development discourses and CSR-policies in agrarian as well as green infrastructure-related investments and how these hide power differences. We argue that the various discourses of development further legitimize the institutional change from common to state and private property of land and land-related common-pool resources (Haller ed 2010 [11]), which is the basis of commons grabbing (Haller 2019 [12], Haller this volume [13]).

Moreover, this collection of papers stresses the fact that investments and neoliberal developments affect not just 'wastelands', but land-related common-pool resources of cultural landscape ecosystems, previously governed by common property institutions. In addition, the authors illustrate the way institutional change leads to legal and institutional pluralism, and how companies and local as well as state elites select from this institutional pluralism (a process labelled as institution shopping, see Toulmin 2008 [14], Haller 2016 [15], 2019 [12]) depending on their bargaining power and for their own interest to enable and legitimate the grabbing processes.

As a general conclusion—and in answering the question posed by the title of the Special Issue—the research presented here suggests that investments using institutional pluralism related to development, not only lead to commons grabbing, but also to "resilience grabbing": CSR programs and compensations in the form of financial payments or employment do not cover local people's loss of common-pool resources for subsistence and cash. In particular, women and minorities are often not able to get access to the few jobs available and to compensations, which are often low and unequally distributed (Marfurt et al 2016 [16], Haller et al 2019 [8]). In the cases where women do get access to jobs, these are badly paid, of short duration and compete with other duties of reproductive work (see Ngutu et al, this volume). This means that access to the commons, which enhanced local resilience in times of crisis in the past, is no longer available, while at the same time the promises of work and access to compensation and development programs are not kept by states and investors. As a consequence, marginal local people are under conditions of commons grabbing more vulnerable to environmental disturbances and less resilient than they were before.

Finally, the contributions of this Special Issue also present local perceptions and related responses of commoners to the grabbing-process, go beyond resistance, acquaintance and incorporation (see Hall et al 2015 [17]). They include further strategies ranging from weapons of the weak (Scott 1987 [18]) to options of mobilization (labelled as politics machines, see Niederberger et al 2016 [19]), containing also institution shopping from below (on customary and human rights laws and regulations, see Marfurt 2019 [20]) and bottom-up institution building processes to reclaim the commons and its new participatory governance (see constitutionality approach by Haller, Acciaioli and Rist 2016 [21], Haller, Belsky and Rist 2018 [22]).

The papers of this Special Issue were written by 22 authors from nine university institutes from five countries (Switzerland, Kenya, Cambodia, New Zealand and Bolivia) covering case studies from Kenya, Tanzania, Morocco, Bolivia, Ecuador, Cambodia. The Special issue is organized in the following way: After the first paper serving as theoretical introductory, the following papers are presented under three main topics such as (a) property transformations and resilience, (b) agricultural neoliberal order and notions of green development and (c) green investments and Anti-Politics Machines:

In the introductory paper [13] theoretical reflections are proposed from a social anthropology perspective that uses a combined New Institutional and Political Ecology approach (NIPE). It looks historically at empirical data from research on African floodplains (Haller ed 2010 [11]). The paper shows that pre-colonial notions of land were embedded into local ontologies and epistemologies, in which land included land-related common-pool resources governed by common property institutions in relation to a non-human and spiritual world. This view also integrated reciprocal access arrangements between different groups that contributed to their resilience. This meaning of land was undermined and defragmented during colonial and post-colonial times, changing, the commons into state and also private property. As a result, this process also contributed to multiple forms of resource regulations for several separated sectors for state administration (agriculture, wildlife, fisheries, water, conservation etc.) of previously inclusively managed cultural landscapes. These new different meanings of land related to institutional pluralism are vital to understand how access to land and related resources is organized in today's neoliberal order following the states debt crisis. Therefore, the paper discusses who has the power to select property rights and resource management institutions and how this selection (institution shopping) can be legitimated by multiple discourses. These include several forms of green economic and sustainable development anti-politics machines used by state elites and investors as well as by local elites to justify investments. Importantly, the paper outlines theoretically how commons grabbing leads to resilience grabbing. Finally, this introduction also proposes that all

local actors should be much more involved in developing coping strategies enhancing resilience based on their knowledge and experience.

These theoretical reflections can be used to help to analyze the institutional issue regarding land and resource management that arise in the other papers in this Special Issue, which are introduced below under three broad topics:

#### **2. Property Transformations and Resilience**

The first three papers provide examples of changes in property rights over time from common to state and private property of the neoliberal order. Furthermore, they describe institutional pluralism and the effect this had on livelihoods and resilience. Because property rights have changed substantially in the past, less powerful local actors find less options to recover from environmental or other stress factors. Such historical processes indicate that the grabbing of the commons during colonial times and the plurality of rights for more powerful external actors has reduced local peoples' resilience historically and pose challenges for coping strategies:

Edwin Ameso et al [23] show in their paper based on anthropological research data how local Maasai groups in Northern Kenya have lost large amounts of common land and related pastures and wetlands during colonial as well as postcolonial times. As a result, their mobility as an important aspect of their resilience capacity is badly affected. Therefore, they have tried to diversify their strategies in order to cope with these changes and in order to sustain pastoralism. Maasai are currently combining property institutions and trying to promote holistic management of pasture and the watersheds, leading to a better co-management of resources. However, they are still facing challenges in order to regain resilience with regard to climate and market changes.

Sochanny Hak, John MacAndrew and Andreas Neef [24] examine land grabs in Cambodia in indigenous people's areas over the last decade. They argue that because of these indigenous people lost their commons in the name of national economic development. They illustrate this process of commons grabbing by using the example of two indigenous communities indicating how the titling processes have failed to provide indigenous villagers with effective legal mechanisms to counteract the grabbing process. In addition, the dependency on cash crops and to the loss of communal forests has contributed to loss of livelihood resilience that is also based on the low bargaining power of local actors.

The issue of asymmetric bargaining power is also the topic of the paper of Jemaiyo Chabeda-Barthe and Tobias Haller [25] who discuss how the minority of the original hunter-gatherer group of the Ogiek in Kenya has lost large tracts of common property of their cultural landscape since colonial times. After independence they have tried to enhance their resilience by focusing on apiculture in an area called Mau Forest. Under the new wave of neoliberal land reform in the country, the Ogiek have handed out land to other allied ethnic groups such as the Kalenjin to prevent encroachment from other powerful ethnic groups such as the immigrant Kikuyu using private property rights of land and powerful state relations. This case also shows how all actors use strategies of institution shopping but that the way to be able to do this relies on historically developed power relations.

#### **3. Agricultural Neoliberal Order and Notions of Green Development**

The next three papers deal with the neoliberal order of agro-industrial capitalist systems and conservation schemes, which shape institutional contexts and resilience of local actors.

Mariah Ngutu et al [26] discuss in their contribution how the agro-industrial food system in Laikipia, Kenya represented by an UK-export oriented commercial horticultural company is driven by a neoliberal privatization of land and resource policies, feeding the European demand for vegetables. This process shapes the access to short-term livelihoods options by offering women poorly paid jobs and increasing their workload as this adds to their domestic and subsistence duties. Furthermore, the actors of the agro-industrial food system have more bargaining power than local peasants to select and transform institutionalized access to former common-pool resources. This undermines local food systems such as agro-pastoralism and small holder agriculture vital for local livelihoods and food

security. Therefore, the livelihood resilience of local actors is undermined, increasing the potential for conflicts across the different food systems.

Horacio Augstburger, Fabian Käser and Stephan Rist [27] introduce a comparative dimension in their paper, in which they study the similarities and differences between the Laikipia area in Kenya (as the previous paper) and the agro-industrial area in Bolivian Lowlands. They analyse the capacity of several locally occurring food systems to enhance sustainable farm-based agroecosystem services and how they affect the sustainable management of common-pool resources. The authors show that in both countries regional and agro-industrial food systems, embedded in a market oriented neoliberal order, are less socio-ecologically sound than local, indigenous and alternative food systems. The former two have negative impacts on agroecosystems, undermining common property and cultural landscapes. They grab the commons and reduce the resilience capacity of the indigenous and alternative systems. Strengthening local, indigenous and alternative food systems and their common property institutions is proposed as a key strategy to promote sustainable farm-based agroecosystems.

Lisa Alvarado [28] illustrates how strategies to support local common property systems is undermined in the context of neoliberal conservation. She outlines that in the Ecuadorian Amazon region of Ecuador, protected areas have been established as a response to the expansion of the agricultural frontier based on the neoliberal rule in the country since 1979. She focuses on the protected area of the *Reserva de Producción Faunística Cuyabeno*, that was previously managed as commons by local indigenous groups of the Siona. Before the establishment of the conservation area, the arrival of several waves of colonizers had already severely compromised traditional institutions of common property. Resource use limitations by the introduction of the protected areas have been the last of these grabbing attempts. This green grabbing now forces the Siona people to legitimize their existence in the park, if they want to stay in their ancestral territory. They argue against the green grabbing, especially based on the negative impact of tourism in the park and by trying to shop institutions based on their (reconstructed) indigenous identity that is protected by international conventions.

#### **4. Green investments and Anti-Politics Machines**

The issue of green grabbing, however in another forms, is the focus of the last three papers, illustrating the environmental turn used by powerful actors of states and companies. These investments show classic forms of commons and resilience grabbing but are embedded in strategies of social and ecological corporate responsibility schemes (CSRs), masking the grabbing process and the undermining of the resilience of marginal groups and women.

Gargule Achiba's [29] paper shows a classical conflict of an internationally-celebrated green investment in a wind park in Northern Kenya. It explains the way land is grabbed but legitimized by green energy Anti-Politics Machine. He shows how the implementation of the wind energy project employs the corporate strategies of depoliticizing both land claims and development interventions. This process hides how the private sector engagement in large-scale wind energy infrastructure has created a complex development apparatus ideologically empowered by using the SDGs and Kenya's related Vision 2030. Furthermore, the green energy grabbing of pastoral land and related common-pool resources is hidden by CSR strategies through which dispossession is justified and legitimized.

Another case of commons grabbing in the name of green energy is illustrated in the contribution of Sarah Ryser [30]. She explains how the largest solar energy project in the world financed by a public–private partnership removes common property of a Moroccan Amazigh (Berber) clan, who's members thereby lose access to pastures and animal fodder. The Anti-Politics Machine of green energy, including compensation payments and CSR development, hides the fact that a very low land price was fixed by the state, and further legitimated by the discourse that the land is wasteland. Furthermore, payments did not reach the communities who also did not fully profit from CSR-programmes and simultaneously lost access to the commons. Thus, they became less resilient as their losses were not replaced by the development gains promised. Women, in particular, lost more than men.

The issue of gender is a particular focus of the paper by Désirée Gmür [31]. She uses data from her research among the ethnic group of the Wahehe farming communities in Kilolo District, Tanzania, who had a common property system regarding land and land-related resources that included resource co-ownership of clan land by women. The investor in this case first tried to get communal land and then later on so-called private land held by men, who sold it and thereby excluded women form access to land, water and other resources. While more common-pool resources were enclosed and were no longer accessible to women, they also lost most of the valuable agricultural land in the valley bottoms used by them for cash crop production. In addition, the grabbing process by the company also reduced access to veld products and to water, leading to the loss of food and cash providing resources on which women depended for their reproductive work. As the traditional rights of women to land has altered, they are more affected by land and commons grabbing than men and have fewer options in trying to defend their former property. The company on the other hand uses a green development discourse to legitimize the selection on environmental legal state institutions and thus the removal of access to the commons.

#### **5. Conclusions**

These case studies indicate several elements of the links between historical and contemporary commons grabbing processes and how they undermine resilience in food and cash production systems as well as general livelihoods for marginalized, local communities in the Global South. The cases presented in this Special Issue show that "resilience grabbing" is the result of commons grabbing as a process, in which powerful state and corporate actors as well as local elites use institutional and legal pluralism in the age of neoliberalism. This provides them with the option to select, activate and transform rules and regulations and to use always new forms of discourses (conservation, green economy, green investment, CSR-development programs and SDGs) to legitimate their actions. While the promises of development has been criticized by Ferguson almost three decades ago [9], the contemporary examples in this Special Issue show the same mechanisms still exist, albeit sometimes in new forms, but still legitimizing unfavorable outcomes for local actors with less bargaining power. The tragedy of this notion of development is that in this way the capacity to recover from a human or environmentally-induced land and resources crisis is reduced. It is assumed that the COVID-crisis and the related economic and political outcomes on the local level might illustrate this trend.

However, there are cases that show different forms of local reactions and coping strategies that should be studied further. These may range from small actions of resistance to larger legal claims. In addition, local groups may develop new identities that boost their bargaining power and try to use strategies of institution shopping from below or engage in the development of bottom-up institution building (see Haller et al 2016 [16]). We argue that further research, preferably participatory research (see Haller and Zingerli 2020 [32]), should focus on these issues.

We hope to have contributed to an understanding that land grabbing in fact removes the communal rights to own and use not just land but land-related common-pool resources in cultural landscape ecosystems. These are central for local actors to be able to recover from market and climate induced crisis and to enhance biodiversity. Undermining these rights and local institutions will accelerate the global degradation process and further reduce the capacity for local actors to build up resilience in the face of global environmental and development crises. Enhancing common property and the development of institutions from below by all actors might be one solution to this set of problems.

**Funding:** The papers of this Special Issue were funded by different research organizations. The respective funding information is provided in the respective papers.

**Acknowledgments:** We are grateful for administrative and technical support provided by the Institute of Social Anthropology and the Centre for Development and Environment (CDE), both University of Bern, Switzerland

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