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Black molds feed by secreting enzymes that dissolve complex molecules, like cellulose, as their filamentous hyphae insinuate themselves in their food sources. Many of the molds that grow in buildings represent single phases in complex microbial life cycles. The diversity of mold species is astonishing, but relatively few species are prevalent in homes. Molds have a variety of effects upon human health. Many provoke allergies, some are implicated in fungal sinusitis, and a small subset can cause life-threatening infections. Evidence of the ubiquity of black molds is found in the fact that their growth on the exterior of office buildings in cities is usually mistaken for the effects of pollution.

This chapter provides a case history of Aracruz Celulose, a Brazilian company established to implement an innovative project – the creation of planted forestry, using fast‐growing eucalyptus, for the manufacture of pulp for the world's paper industry. This chapter discusses issues of sustainable development, social benefits, environmental management, and challenges.

An altruistic act is one in which an individual incurs a cost that results in a benefit to others. Giving money or time to those less fortunate than ourselves is one example, as is giving up one’s seat on a bus. At first, one might consider such behaviour hopelessly naive in a world in which natural selection seemingly rewards selfishness in the competitive struggle for existence. As the saying goes, ‘nice guys finish last’. Yet examples of apparent altruism are commonplace. Meerkats will spend hours in the baking sun keeping lookout for predators that might attack their colony mates. Vampire bats will regurgitate blood to feed their starving roost fellows, while baboons will take the time and effort to groom other baboons. Some individuals, such as honeybee workers, forego their own reproduction to help their queen and will even die in her defence. The common gut bacterium Escherichia coli commits suicide when it is infected by a bacteriophage, thereby protecting its clones from being infected. If helping incurs a cost, then surely an individual that accepts a cooperative act yet gives nothing in return would do better than cooperators? What, then, allows these cases of apparent altruism to persist? In his last presidential address to the Royal Society of London in November 2005, Robert M. May argued, ‘The most important unanswered question in evolutionary biology, and more generally in the social sciences, is how cooperative behaviour evolved and can be maintained’. In this chapter, we document a number of examples of cooperation in the natural world and ask how it is maintained despite the obvious evolutionary pressure to ‘cheat’. We will see that, while it is tempting to see societies as some form of higher organism, to fully understand cooperation, it helps to take a more reductionist view of the world, frequently a gene-centred perspective. Indeed, thinking about altruism has led to one of the greatest triumphs of the ‘selfish gene’ approach, namely the theory of kin selection. Ultimately, as the quote from Mandeville indicates, we will see that cooperation frequently arises simply out of pure self-interest—it just so happens that individuals (or, more precisely, genes) in the business of helping themselves sometimes help others.

Among the components of bio-nanocomposites, the nanometer sized biofillers from biomass show unique advantages over traditional inorganic nanoparticles by virtue of their biodegradability and biocompatibility. Currently, biomass-based nanofillers include the rod-like whiskers of cellulose and chitin, the platelet-like nanocrystals of starch, the self-organized nanophase of supramolecular lignin complexes, and many artificial nanofillers derived from biomass. Biofillers that do not have a cellulose origin are defined as noncellulosic biofillers. Besides the inherent biodegradability and biocompatibility of biomass-based polymers, these nanometer sized noncellulosic biofillers have the following predominant advantages over inorganic nanoparticles: (1) Biofiller materials are abundant, renewable, and easily available; (2) Application of the biofiller can improve the bioeconomy; (3) The as-prepared biofillers are low density, and thus can not severely increase, and may even decrease, the specific gravity of nanocomposites; (4) Biofillers have high specific strength and modulus, i.e. high rigidity, that contribute a reinforcing function; (5) Biofillers have comparatively easy processability due to their nonabrasive nature, which allows high fill levels and hence a significant cost savings; (6) The relatively reactive surface of biofillers, covered with many hydroxyl groups, provides a great opportunity for chemical modification and grafting; (7) Recycling by combustion of noncellulosic biofiller-filled composites is easier in comparison with inorganic filler systems; (8) The self-organized arrangement of biofillers in nanocomposites may regulate electronic, optical, magnetic, and superconductive properties. As a result, the possibility of using noncellulosic biofillers in bio-nanocomposites has received considerable interest.

As nanocomposites composed of bio-based epoxy resins, bio-based hardeners, and nanofillers, polyglycerol polyglycidyl ether (PGPE) / ε-poly(L-lysine) (PL) / montmorillonite (MMT), glycerol polyglycidyl ether (GPE) / tannic acid (TA) / microfibrillated cellulose (MFC), and sorbitol polyglycidyl ether (SPE) / TA / MFC bio-nanocomposites were prepared by use of thermal curing reactions. Also, new bio-based nanocomposites composed of epoxidized soybean oil (ESO) and self-assembled hydroxystearic acid (HSA) nanofibers were prepared by use of photo-curing reaction. The thermal and mechanical properties and morphologies of the PGPE-PL/MMT, GPE-TA/MFC, SPE-TA/MFC, and ESO/HSA bio-nanocomposites were investigated in detail.

A grassland's plants combine the energy from the sun with water and nutrients from the soil to grow and reproduce. These plants produce the stuff of life and growth for grass eaters. There are carbohydrates for energy and protein for growth and repairing body parts. Digesting anything is a strictly chemical matter of subjecting it to an enzyme that breaks certain molecular bonds. Bison don't secrete an enzyme that digests cellulose either, but they enlist colonies of bacteria. The front part of their stomach is segmented off by a fold (the rumen) in which newly swallowed food is kept for a while. It serves as a place where some very helpful bacteria put their enzymes to work digesting the cellulose. The ruminants have enlisted a powerful ally in their arms race with grass.

In chapter 5 we focused on the informational interface between cells and synthetic components of systems. This interface is concerned with facilitating and manipulating information transport and processing between and within the synthetic and whole-cell components of these hybrid systems. However, there is also a structural interface between these components that is concerned with the physical placement, entrapment, and maintenance of the cells in a manner that enables the informational interface to operate. In this chapter we focus on this structural interface. Successful integration of whole-cell matrices into microscale and nanoscale elements requires a unique environment that fosters continued cell viability while promoting, or at least not blocking, the information transport and communication pathways described in earlier chapters. A century of cell culture has provided a wealth of insight and specific protocols to maintain the viability and (typically) proliferation of virtually every type of organism that can be propagated. More recently, the demands for more efficient bioreactors, more compatible biomedical implants, and the promise of engineered tissues has driven advances in surface-modification sciences, cellular immobilization, and scaffolding that provide structure and control over cell growth, in addition to their basic metabolic requirements. In turn, hybrid biological and electronic systems have emerged, capable of transducing the often highly sensitive and specific responses of cellular matrices for biosensing in environmental, medical, and industrial applications. The demands of these systems have driven advances in cellular immobilization and encapsulation techniques, enabling improved interaction of the biological matrix with its environment while providing nutrient and respiratory requirements for prolonged viability of the living matrices. Predominantly, such devices feature a single interface between the bulk biomatrix and transducer. However, advances in lithography, micromachining, and micro-/nanoscale synthesis provide broader opportunities for interfacing whole-cell matrices with synthetic elements. Advances in engineered, patterned, or directed cell growth are now providing spatial and temporal control over cellular integration within microscale and nanoscale systems. Perhaps the best defined integration of cellular matrices with electronically active substrates has been accomplished with neuronal patterning. Topographical and physicochemical patterning of surfaces promotes the attachment and directed growth of neurites over electrically active substrates that are used to both stimulate and observe excitable cellular activity.

The first part of this book has proposed that tissue engineering is a modern realization of a practice with ancient origins. Tissue engineering is different because technologies that are now available permit generation of synthetic materials that mimic biological materials as well as clinically useful quantities of biological components (such as proteins and cells). These technologies have emerged from rapid advances in the biological sciences and engineering over the past few decades. Since tissue engineering is new, however, few examples of successful tissue engineering are available. The reader, upon recognizing this early stage of development, might presume that the prospects for a compelling chapter on “Approaches to Tissue Engineering” are bleak. Instead, I am convinced that this is the most exciting of times to write such a chapter, because the precedents are not yet assembled and the field has not yet been reduced to systematic divisions. But there are many challenges. The challenge begins with organization of information. Written reviews of tissue engineering to date adopt different organizational structures. For example, an early influential review was organized around replacement strategies for different organ or tissue systems. A similar, although more encyclopedic, approach was used in the first two editions of an edited textbook. This is a sensible arrangement, given that tissue engineering is an interdisciplinary area of study that has emerged in response to rather specific clinical needs, such as the shortage of donor livers and the paucity of grafts for skin. But it is a difficult arrangement for the teacher and student, as it does not require reconciliation between approaches used to solve different problems. For example, although regeneration of skin and liver differs in many essential ways, there are important areas of intersection. As a consequence, an organ or tissue-based approach does not easily allow for assimilation of new knowledge that is acquired by successes made on particular problems. What is tissue engineering and how can the basic principles, which are developed in Part 2 of this book, be integrated into a strategy for the engineering of replacement tissues? The previous three chapters describe important, but focused, elements of tissue engineering practice: cell delivery, agent delivery, and cell interactions with synthetic materials.

This chapter addresses the dietary and nutritional information initially reported by Schaller et al. for giant pandas from Wolong. Captive feeding demonstrates that pandas may be capable of more flexibility in food consumption than one might see at a given field site. Moreover, the chapter presents an in-depth analysis of animal and bamboo feeding from data collected in the Qinling Mountains during more than ten years of effort. The selectiveness seen in their feeding behavior reflects in part the adaptation of giant pandas to a bamboo niche. Utilization of special nutrients, such as hemicellulose and cellulose, is considered. A brief report that discusses the cognitive processes used in locating food is then offered. It shows that giant pandas would rank fairly high on any animal intelligence scale, and cites research illustrating that such perceptions strongly influence support for their conservation.

As noted earlier and as anticipated by Charles and Francis Darwin it has been argued that plants sense the direction of gravity (gravitropism) by movement of starch granules found in cells called statocytes that contain compartments (organelles) called statoliths. The synthesis of statoliths appears to occur in the plastid (plant organelle) compartments called amyloplasts (Figure 7.1, 1). It has been suggested that this gravitropic signal then leads to movement of plant hormones such as indole-3-acetic acid (auxin) (Figure 7.2), through the phloem opposite to the pull of gravity to promote stem growth. Chloroplasts (Figure 7.1, 2) are cell compartments (plastids or organelles) in which photosynthesis is carried out. The process of photosynthesis, discussed more fully later, is accompanied by the production of adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and inorganic phosphate (Pi) (Figure 7.3). ATP is consumed and converted to ADP and Pi in living systems. The cycle of production and consumption allows ATP to serve as an “energy currency” to pay for the reactions in living systems. Beyond this generally recognized critical function of chloroplasts, it has recently been pointed out that light/ dark conditions affect alternative splicing of genes which may be necessary for proper plant responses to varying light conditions. The organelles or plastids which contain the pigments for photosynthesis and the amyloplasts that store starch are only two of many kinds of plastids. Other plastids, leucoplasts for example, hold the enzymes for the synthesis of terpenes, and elaioplasts store fatty acids. Apparently, all plastids are derived from proplastids which are present in the pluripotent apical and root meristem cells. The cell wall (Figure 7.1, 3) is the tough, rigid layer that surrounds cells. It is located on the outside of the flexible cell membrane, thus adding fixed structure. A representation of a portion of the cell wall (as made up of cellulose and peptide cross-linking) is shown below in Figure 7.7. The cells will have different sizes as a function of where they are found (e.g., leaf, stalk, root), but in every case, the cell wall limits the size of the membrane that lies within.

Elemental silicon on which the entire technology is based is typically obtained by reduction of the mineral silica with carbon at high temperatures: . . . SiO2 + 2C → Si 2CO (2.1) . . . The silicon is then converted directly to tetrachlorosilane by the reaction . . . Si + 2Cl2 → SiCl4 (2.2) . . Tetrachlorosilane can be used to form an organosilane by the Grignard Reaction . . . SiCl4 + 2 RMgX → R2SiCl2 + 2 MgClX (2.3). . . This relatively complicatreaction has been replaced by the so-called Direct Process or Rochow Process, which starts from elemental silicon as is illustrated by the reaction . . . Si + 2 RCl → R2SiCl2 (2.4) . . . This process also yields RSiCl3 and R3SiCl, which­­ can be removed by distillation. Compounds of formula R2SiCl2 are extremely important as intermediates to a variety of substances having both organic and inorganic character. Hydrolysis gives dihydroxy structures, which can condense to give the basic [–SiR2O–] repeat unit. The nature of the product obtained depends greatly on the reaction conditions. Basic catalysts and higher temperatures favor higher molecular weight linear polymers. Acidic catalysts tend to produce cyclic small molecules or low molecular weight polymers. The hydrolysis approach to polysiloxane synthesis has been largely replaced by ring-opening polymerization of organosilicon cyclic trimers and tetramers, with ionic initiation. These cyclic monomers are produced by the hydrolysis of dimethyldichlorosilane. Under the right conditions, at least 50 wt % of the products are cyclic oligomers. The desired cyclic species are separated from the mixture for use in ring-opening polymerizations such as those described in the following section. In addition, “click” chemistry has been developed for new synthesis techniques in general, and polymerizations in particular. These approaches have been used to prepare polysiloxane elastomers and polydimethylsiloxane (PDMS) copolymers that can function as thermoplastic elastomers. New synthetic strategies for structured silicones, based on B(C6F5)3 have also been developed. Another new approach involves enzymes, such as the lipase enzymatically catalyzed synthesis of silicone aromatic polyesters and silicone aromatic polyamides.

Gelation is the cross-linking process that leads to the network structures required for rubberlike elasticity. In some cases, gelation can be reversible. There have been numerous studies involving theory and simulations exploring gelation and the mechanical properties of the resulting networks. Cross linking with free radicals is still quite common. Radiation has often been used to carry out the cross linking, as have new techniques known as “click” chemistry. Hydrosilylation is also popular. Networks have even been designed with movable cross links. Finally, reactive groups can be placed at the chain ends or within the chains themselves. Related studies have involved polydimethylsiloxane (PDMS)-based organogelators, web-to-pillar transitions of gels, and silica aerogels. There has also been interest in polysiloxanes in interpenetrating hydrogels with high oxygen permeabilities and viscoelastic magnetic gels. Organic-inorganic hybrids with relatively low melting temperatures also exist, some of which can be made to be self-healing. Gels are also formed in swelling experiments, which are useful for equilibrium experiments to characterize network structures. One of the recent topics in this area involves stimuli-responsive gels, under the descriptive title of “self-walking gels” “wormlike motion of gels,” and “peristaltic motion of gels.” The earliest studies of networks formed in solution were undertaken to investigate some subtle aspects of the elastic free energy expression— whether or not an additional term in the logarithm of the volume was required. Other studies focused on the properties of networks in general. As can be gathered from chapter 4, it is difficult to obtain information on the topology of a network. Some studies have therefore taken an indirect approach. Networks were prepared in a way as to simplify their topologies, and their properties were measured and interpreted in terms of reduced degrees of network-chain entanglement. The two techniques employed involved separating the chains prior to cross linking by either dissolution or stretching. After cross linking, the solvent is removed or the stretching force is relaxed, and the network is studied (unswollen) with regard to its stress-strain properties, typically in elongation.

Like other amino acids, the aromatic amino acids phenylalanine, tyrosine, and tryptophan are vitally important for protein synthesis in all organisms. However, while animals can synthesize tyrosine via oxidation of phenylalanine, they can synthesize neither phenylalanine itself nor tryptophan and so these essential amino acids must be obtained in the diet, usually from plant material. Though many other investigators made significant contributions in this area over the years, it was Bernhard Davis in the early 1950s whose use of mutant stains of Escherichia coli led to a full understanding of the so-called shikimic acid pathway that is used by plants and also by some microorganisms for the biosynthesis of these essential amino acids. The pathway is almost completely devoted to their synthesis for protein production in bacteria, while in plants the pathway extends their use to the construction of a wide array of secondary metabolites, many of which are valuable medicinal agents. These secondary metabolites range from simple and familiar compounds such as vanillin (vanilla flavor and fragrance) and eugenol (oil of clove, a useful dental anesthetic) to more complex structures such as pinoresinol, a common plant biochemical, and podophyllotoxin, a powerful cancer chemotherapy agent. Earlier in Chapter 3, we encountered two important intermediates, erythrose-4-phosphate and phosphoenolpyruvate (PEP), each of which was derived from a different pathway utilized in carbohydrate metabolism. Erythrose-4-P was an intermediate in one of the steps of the pentose phosphate pathway while hydrolysis of PEP to pyruvic acid was the final step in glycolysis. These two simple intermediates provide the seven carbon atoms required for construction of shikimic acid itself. The two are linked to one another via a sequence of enzyme-mediated aldol-type reactions, the first being a bimolecular reaction and the second an intramolecular variant that ultimately leads to a cyclic precursor of shikimic acid known as 3-dehydroquinic acid as shown in Fig. 6.3. Subsequent dehydration of 3-dehydroquinic acid leads to 3-dehydroshikimic acid which then leads directly to shikimic acid via NADPH reduction.

I came to Penland to write. The craft s were dear to me; first textiles, especially bobbin lace, which my wife made and collected, and taught me to look at. Then the Japanese ceramics to which Kenichi Fukui and Fred Baekeland introduced me. Followed by the protochemistry of dyeing with indigo from snail and plant sources, to me still the ideal bridge between science and culture. The tribute is to be seen around my house—my children’s inheritance consumed as much by crafts as “high” art. So it was easy to accept an invitation to come to Penland and write. Who knew what would come—I wanted to write poems, perhaps an essay. For the poems I’ve needed nature—not so much to write about as to shake me loose from the everyday worries of the (exciting) daily life I had in Ithaca. Nature was a path to concentration; I expected to find a different nature in the foothills of the Blue Ridge Mountains. I would watch the crafts process. Maybe someone would even let me try something. Or ask me to tell them of the chemistry of their craft. I, in turn, would craft my poems out of the green hills. But this is not what happened; here’s what happened: I walk into Billie Ruth Sudduth’s basketry class, and there’s the whole group dyeing their canes, steaming pots of synthetic dye. I ask someone what they are doing, and she says, “Well, I’m getting ready for the upsetting,” and then seeing the puzzled look on my face, patiently explains this old, wonderfully direct basketry term for bending the canes forming the base of a basket over themselves, so that they stand up. I walk uphill to the iron shop, clearly more of a macho place, watch an intense young man, lawyer become sculptor as it turns out, hammer out a hand on a swage block. Ben tells me that it’s possible to burn away the carbon in the steel, and the iron would “burn” too, oxidize, in too hot a flame.

This chapter examines the nature of viscose manufacturing and the known or suspected toxic effects of carbon disulfide. It begins with a history of carbon disulfide, which was first synthesized in 1796 by a German mining and metallurgical chemist named Wilhelm August Lampadius. Soon the potent anesthetic effects of carbon disulfide were revealed in various experiments. An outbreak of disease due to carbon disulfide in a prerevolutionary Russian viscose factory was an important early report of worker ill health and only the second one specific to the nascent viscose rayon industry. In 1892 it was discovered that carbon disulfide was uniquely capable of liquefying cellulose without fundamentally changing its structure, which became the basis for producing artificial silk. However, treating cellulose with large quantities of carbon disulfide was a highly dangerous process. This chapter considers the evidence showing that viscose rayon caused worker disease and death in factories.

Chapter 2 describes conversion of cellulose to useful products in the 19th century (rayon, celluloid, guncotton) and the role of glucose in its chemical structure. The preparation of candy floss (cotton candy) is described and how the method is relevant to spinning synthetic fibres. The composition of sugar and the composition of foods is explained. In particular, the distinction among starch, sugar, carbohydrates, monosaccharides, and polysaccharides is made. Conversion of crops to bioethanol is described.