bluuebunny/crossref_metadata_2025 huggingface dataset:
What a Wetland Is, and Isn’t
Authors: Lewis William M.
Published: November 2020

Uneven distribution of water causes the landscape to be divided into four parts: lakes, streams, uplands, and wetlands. Lakes are distinguished from the rest by the presence of water standing at considerable depth over long intervals. As a rule of thumb, the water of a lake is deep enough to prevent the growth of rooted vegetation over most of its area. Streams (and rivers, which are simply large streams) are moving waters confined by a channel. Uplands are seldom or never covered with water and are fully saturated to points near the surface only during cold weather or for short intervals during the growing season. Parts of the landscape that remain after the exclusion of lakes, streams, and uplands are wetlands. Wetlands may be inundated constantly, seasonally, or never. If never inundated or inundated seasonally—as are the lands on river floodplains—wetlands can be dry at the surface. Even so, they will be very wet just underneath for all or much of the growing season. Wetlands thus are places where heavy equipment is likely to churn up mud even after the weather has been dry for some time. Water provokes important responses from plants, animals, and microbes that in turn cause uplands, wetlands, lakes, and streams to be fundamentally different from each other. Where water stands for long periods at a depth of several feet, we find organisms with life cycles that presume the constant presence of water, and the sediment lacks the properties of a true soil. Where the land is characteristically dry at and near the surface during the growing season, the assortment of species is different, and typically there is a soil with well-defined structure in the form of layers (horizons). Wetlands are different from either of these in that their resident communities can tolerate water saturation or inundation for long intervals but usually can withstand desiccation of the surface as well. They form soils, but of a class distinct from the soils of uplands. Thus, the uneven distribution of water causes some predictable kinds of variation in living communities and soils, both of which can be used in defining and mapping wetlands.
What Wetlands Do, and How They Do It
Authors: Lewis William M.
Published: November 2020

Those who question the wisdom of wetland regulations sometimes tell a story about a landowner who proposes to build a fine home on a tract of land that is largely wetland. This landowner lives in a region where wetlands are abundant but is denied permission to build on grounds that construction would involve filling a wetland. Because he owns considerable property, the owner moves to higher ground, clears five acres of mature upland timber, and builds his home quite legally in this way. The irony is that the mature upland timber is much scarcer locally than wetland, and the stupidity of the regulation is to have forced someone to destroy the scarcer of two resources. The names, places, and other particulars of this story vary with the teller, but there is little doubt that wetland regulation has sometimes caused an environmental loss greater than the value of the wetland that is preserved. Perhaps the landowner in the story could have been given an exemption had he only been allowed to argue the great value of mature upland forest in his particular region. As a practical matter, however, special pleading can defeat the intent of almost any regulation. Thus, the rigidity in the regulation may be justified by its need to be faithful to the general intent of the underlying law and not by a need to be rational in every case. At any rate, the story may be specious as a generalization in that the Army Corps in most cases would have granted a permit to an individual for a small wetland conversion, or the conversion would have been covered under a general permit for small conversions (chapter 1). Those who question the wisdom of wetland regulations sometimes tell a story about a landowner who proposes to build a fine home on a tract of land that is largely wetland. This landowner lives in a region where wetlands are abundant but is denied permission to build on grounds that construction would involve filling a wetland. Because he owns considerable property, the owner moves to higher ground, clears five acres of mature upland timber, and builds his home quite legally in this way.
Applications of Synthetic Peptides
Authors: Hruby Victor J. , Matsunaga Terry O.
Published: November 2020

The tremendous advances in the development of methods for the design and synthesis of peptides. pseudo-peptides and related compounds, as well as the corresponding advances in our understanding of peptide and protein structure, conformation, topography, and dynamics provides unique opportunities to apply designed synthetic peptides for an enormous variety of problems in chemistry, biology, and medicine. In addition, if these advances can be coupled to the advances in molecular biology and the human genome project, on the one hand, and asymmetric synthesis and catalysis, on the other, it should be possible to provide hitherto unavailable, indeed unthinkable, approaches to diverse areas of drug design, behavioral neuroscience, molecular immunology, chemotherapy, and a wide variety of other uses. Already it is clear that peptide therapy has enormous potential in such diverse areas as growth control, blood pressure management, neurotransmission, hormone action, satiety, addiction, pain, digestion, reproduction, and so forth. Nature has “discovered” that it can control nearly all biological processes by various kinds of molecular recognition, and that peptides and proteins are uniquely suited for this control because of their enormous potential for diversity and their unique physico-chemical properties. This finding may, perhaps, be most readily understood if one recognizes that, considering only the 20 normal eukaryotic amino acids, the number of unique chemical entities for a pentapeptide is 3,200,000 (205), for a hexapeptide it is 64,000,000 (206), and so on. Considered from this perspective, perhaps it is not unexpected that Nature has “discovered” that peptides and proteins can do it all, from providing structure and motion, to catalysis, to information transduction, to growth and maturation, and so on. The ability of the immune system in higher animals, including humans, to recognize literally millions of foreign materials made by Nature as well as humans, and to get rid of them as part of its survival strategy, is just one example that illustrates the potential of peptide-based drugs, therapeutics, and modulators of biological function. Despite the enormous potential of peptides and small proteins for these areas, surprisingly little advantage has been taken of the potential of these molecules as drugs and tools for use in basic and clinical research.
The Role of Disturbances in Shortgrass Steppe Community and Ecosystem Dynamics
Authors: Peters Debra P. C. , Lauenroth William K.
Published: November 2020

The disturbance regime of an ecosystem consists of a number of different types of disturbance agents operating over a range of spatial and temporal scales (Pickett and White, 1985). Each type of disturbance has its own set of characteristics, including size, frequency of occurrence, intensity, and attributes associated with location, including soil texture, topographic position, and grazing intensity by cattle. These characteristics result in different short-term localized effects on ecosystems as well as long-term broad-scale effects as the disturbances accumulate through time. Disturbance effects occur at multiple levels of organization, from individuals to populations, communities, and the ecosystem. Effects of disturbance can also vary for different types of organisms or processes associated with plants, animals, and soils. Understanding interactions among the characteristics of a disturbance and the properties associated with the response variable is key to understanding and predicting recovery patterns through time and space. Although successional studies have been conducted in grasslands for more than a century, our understanding of the roles of different kinds of disturbances in generating and maintaining patterns in vegetation and in determining species dominance in shortgrass ecosystems has developed only since the 1980s. Referred to as gap dynamics, our current view of the role of disturbance is a dynamic one, in which the recovery of vegetation depends upon interactions among disturbance characteristics and the life history traits of plants. This gap dynamics conceptualization provides an alternative view of vegetation dynamics compared with traditional successional models based on Clements (1916, 1928). Much of the recent work on disturbances in the shortgrass steppe focuses on the relationships between disturbance characteristics and plant life history traits to test the different Clementsian-based models. Most successional studies of shortgrass communities prior to the 1980s focused on recovery after large-scale disturbances and, in particular, cultivation and subsequent abandonment of agricultural 1 elds (Costello, 1944; Judd, 1974; Judd and Jackson, 1939; Savage and Runyon, 1937). The earliest studies were based upon a Clementsian model (Clements, 1916, 1928) that formed the t raditional v iew of succession in these communities (Fig. 6.1). This model predicted that shortgrasses would dominate cover within 25 to 50 years after abandonment.
Estimation and Simulation
Authors: Rubin Yoram
Published: November 2020

Two important applications of the SRF concept developed in chapter 2 are point estimation and image simulation. Point estimation considers the SRF Z at an unsampled location, x0, and the goal is to get an estimate for z at x0 which is physically plausible and is optimal in some sense, and to provide a measure of the quality of the estimate. The goal in image simulation is to create an image of Z over the entire domain, one that not only is in agreement with the measurements at their locations, but also captures the correlation pattern of z. We start by considering a family of linear estimators known as kriging. Its appeal is in its simplicity and computational efficiency. We then proceed to discuss Bayesian estimators and will show how to condition estimates on “hard” and “soft” data, and we shall conclude by discussing a couple of simple, easy-to-implement image simulators. One of the simulators presented can be downloaded from the Internet. Linear regression aims at estimating the attribute z at x0: z0 = z(x0), based on a linear combination of n measurements of z: zi = z(xi), i = 1 , . . . ,n. The estimator of z(x0) is z*0, and it is defined by What makes this estimator “linear” is the exclusion of powers and products of measurements. However, nonlinearity may enter the estimation process indirectly, for example, through nonlinear transformation of the attribute. The challenge posed by(3.1) is to determine optimally the n interpolation coefficients λi, and the shift coefficient λ0. The actual estimation error is z*0 - z0; it is unknown, since z0 is unknown, and so no meaningful statement can be made about it. As an alternative, we shall consider the set of all equivalent estimation problems: in this set we maintain the same spatial configuration of measurement locations, but allow for all the possible combinations, or scenarios, of z values at these locations, including x0. We have replaced a single estimation problem with many, but we have improved our situation since now we know the actual z value at x0 and this will allow a systematic approach.
An Overview of Stochastic Tools for Modeling Transport of Tracers in Heterogeneous Media
Authors: Rubin Yoram
Published: November 2020

Spatial variability and the uncertainty in characterizing the flow domain play an important role in the transport of contaminants in porous media: they affect the pathlines followed by solute particles, the spread of solute bodies, the shape of breakthrough curves, the spatial variability of the concentration, and the ability to quantify any of these accurately. This chapter briefly reviews some basic concepts which we shall later employ for the analysis of solute transport in heterogeneous media, and also points out some issues we shall address in the subsequent chapters. Our exposition in chapters 8-10 on contaminant transport is built around the Lagrangian and the Eulerian approaches for analyzing transport. The Eulerian approach is a statement of mass conservation in control volumes of arbitrary dimensions, in the form of the advection-dispersion equation. As such, it is well suited for numerical modeling in complex flow configurations. Its main difficulties, however, are in the assignment of parameters, both hydrogeological and geochemical, to the numerical grid blocks such that the effects of subgrid-scale heterogeneity are accounted for, and in the numerical dispersion that occurs in advection-dominated flow situations. Another difficulty is in the disparity between the scale of the numerical elements and the scale of the samples collected in the field, which makes the interpretation of field data difficult. The Lagrangian approach focuses on the displacements and travel times of solute bodies of arbitrary dimensions, using the displacements of small solute particles along streamlines as its basic building block. Tracking such displacements requires that the solute particles do not transfer across streamlines. Since such mass transfer may only occur due to pore-scale dispersion, Lagrangian approaches are ideally suited for advection-dominated situations. Let us start by considering the displacement of a small solute body, a particle, as a function of time. “Small” here implies that the solute body is much smaller than the characteristic scale of heterogeneity. At the same time, to qualify for a description of its movement using Darcy’s law, the solute body also needs to be larger than a few pores. The small dimension of the solute body ensures that it moves along a single streamline and that it does not disintegrate due to velocity shear.
The Lagrangian Picture, Part I : Fundamentals of the Lagrangian Approach to Solute Transport
Authors: Rubin Yoram
Published: November 2020

This chapter explores the principles of the Lagrangian approach to solute transport, with an emphasis on the dispersive action of the spatial variability of the velocity field. We start by developing the tools for characterizing the displacement of a single, small solute particle that will subsequently be used for characterization of the concentration’s variability and uncertainty, and we continue with a discussion of the stochastic description of solute travel times and fluxes. The principles presented in this chapter will be employed in chapter 10 to derive tools for applications such as macrodispersion coefficients, solute travel time moments, the moments of the solute fluxes and breakthrough curves, and transport of reactive solutes. As has been observed in many field studies and numerical simulations, the motion of solute bodies in geological media is complex, making the geometry of the solute bodies hard to predict. Furthermore, the concentration varies erratically, sometimes by orders of magnitude, over very short distances. The variability of the velocity field plays a significant role in shaping this complex geometry, and makes it impossible to characterize the concentration field deterministically. The alternatives we will pursue include characterizing the concentration through its moments such as the expected value and variance, and other descriptors of transport such as solute fluxes and travel times. This line was pursued in chapter 8 using the Eulerian framework. In this chapter we pursue this line from the Lagrangian perspective. Applications of these concepts are presented in chapter 10. Let us consider the displacement of a marked solute particle over time.
Vadose Zone, Part II : Transport
Authors: Rubin Yoram
Published: November 2020

This chapter is an extension of our discussion on transport in chapters 7 to 10. Our goal here is to explore a few aspects of the transport problem which are unique to variably saturated soils. The heterogeneity of soils affects transport of solutes in the vadose zone in different ways. It leads to irregular and hard-to-predict spreading of the solutes. The solutes may be channeled through highly conductive flow channels where diffusion plays only a minor role. This may lead to concentrations which are high and travel times which are fast compared to what one may anticipate by assuming that the medium is homogeneous. Evidence for such behavior was found in field experiments (cf. Wierenga et al., 1991; Ellsworth et al., 1991; Ritsema et al., 1998; Sassner et al., 1994) and in large-scale laboratory experiments (Dagan et al., 1991). Hence, the effects of heterogeneity must be recognized and modeled. The effects of heterogeneity can be modeled by employing the stochastic concepts discussed in earlier chapters. The approach for modeling contaminant transport which is the least restrictive in terms of assumptions introduced is the MC simulation. This approach will be reviewed briefly in section 12.1. Modeling of the mean concentration along our discussion in chapter 8 is computationally less demanding compared to MC simulations, yet is less informative since the concentration in the field can hardly be expected to be equal to its expected value. Applications along that line are limited since deriving the macrodispersion coefficients needed for such an undertaking is difficult. Nonetheless, we shall discussed this approach in section 12.2, for the insight into the transport processes it provides. A few simple models are available for gravitational flow through shallow depths. These methods are of course limited in applications, yet they are less demanding in terms of data requirements and the computational efforts involved. Such methods are the focus of the last section in this chapter. The concept of MC simulation was discussed in earlier chapters.
Pre-1860 Responses to Change Views of the Public Good
Authors: Cumbler John T.
Published: November 2020

Timothy and Theodore Dwight saw the coming of the mills and manufacturing as an example of industry and energy among the people of New England. The Dwights looked at the development of industrialization in New England at its early stages. For them, mills and manufacturing signified increased wealth and employment, a belief shared by many New Englanders. Theodore Lyman III believed that without manufacturing, New England would be poor, miserly, and ignorant. Not all New Englanders were as optimistic about manufacturing, but those who were had the support of the courts, and significant influence in the highest offices of the region. Nineteenth-century New Englanders of all stripes realized that a rural agrarian society was giving way to an urban industrial society. They understood that this transformation not only affected the immediate environment of cities and towns but also reached into the surrounding countryside, to the farms along the river valley, up to the forests of the hills and mountains, and into the waters of the rivers, brooks, and streams that flowed awav from the factories, towns, and cities. Dams dotted the late eighteenth-century countryside. But the dams, even the small eighteenth-century ones, also flooded fields and blocked the migrating fish. In the eighteenth century, farmers and fishers whose fields were flooded by the mill dams or whose fishnets were empty because of a dam blocking the migration of anadromous fish often took direct action against the dams. The judges of the Massachusetts Supreme Judicial Court noted that if a dam was seen as a common nuisance, “any individual of their private authority might tear it down at any season.” In 1799, Elijah Boardman and several of his Connecticut River Valley friends climbed onto Joseph Ruggles’s mill dam and ripped out the upper portion, which had raised the dam an additional ten inches and flooded fifty acres of land. Boardman admitted to destroying Ruggles’s dam but claimed the right to do so on the grounds that the dam was a public nuisance. In 1827, Oliver Moseley and twelve of his friends entered Horace White’s mill dam site and tore down the dam across the Agawam River, claiming that the dam was a nuisance.
Childhood Leukemia Near Nuclear Plants
Authors: Goldstein Inge F. , Goldstein Martin
Published: November 2020

In 1983 a television crew was making a documentary film about the health of the employees of a nuclear fuels reprocessing plant in England on the coast of the Irish Sea. This plant had previously been the site of a facility for the production of plutonium for nuclear weapons until it was converted to fuels processing after a fire in the reactor in 1957, during which there had been some release of radioactive material to the environment. The crew, filming in a town called Seascale 3 kilometers from the plant, where a number of the employees lived, was shocked to learn from the townspeople that there had been a surprising number of cases of leukemia among their children. Childhood leukemia is a rare disease, but in this small town there had been five cases in the preceding few years, ten times the number of cases that would have been expected from the average rate elsewhere in Great Britain. The focus of the film was changed from the health of the staff of the nuclear facility to the childhood leukemia in Seascale. Shown on television later that year, it aroused national attention and concern, making its points forcefully with shots of rapidly clicking Geiger counters in the neighborhood of the plant, claims that the coastline there is “the most radioactive environment on earth,” interviews with the anguished parents of sick or deceased children, reports of cows on neighboring farms born with malformations, and scenes of children playing on the beach with the smokestacks of the plant in the immediate background. It also reported that there had been some 300 other accidents at the plant in which radiation had been released, though the amounts were all of lesser magnitude than in the 1957 fire. The process for recovering plutonium from spent fuel from power plants does not recover all the plutonium, and some has to be disposed of as waste, along with other radioactive elements. Those responsible for the design of the plant had made the decision, based on both economic considerations and what was then known about the health hazards of radiation, to discharge much of this radioactive waste into the Irish Sea.
Cell Aggregation and Tissue Equivalents
Authors: Saltzman W. Mark
Published: November 2020

Development of an individual from a fertilized egg involves a rich choreography of cell division, cell movement, and cell shape change. Cells replicate, interact with their surroundings, and move individually and in coordination. Development produces a multicellular organism in which cells are organized into cooperative communities. Adult tissues and organs are orderly ensembles of cells—usually the ensemble contains more than one type of cell—in which both ensemble architecture and dynamic interactions between individual cells are critical for proper function. Tissues are collections of cells, united for a common function. Tissues that differ in function also differ in architecture, that is, in the shape and arrangement of cells. Even in the absence of other information, this observation could lead one to speculate on the power of the influence of cell–cell interactions on tissue development and function. It is well known that selective cell adhesion is a fundamental mechanism underlying mammalian development (see Chapter 3). But cell adhesion and cell–cell communication are essential throughout the lifetime of an organism. The previous three chapters described the biophysical processes of division, adhesion, and motility and introduced some of the molecular mechanisms that cells use to interact with, and learn about, their environment. This chapter considers the relationship of cell adhesion to cell aggregation, or the formation and maintenance of cell communities. The role of cell adhesion in circulation and trafficking of cells throughout the body is discussed in Chapter 10. A community is often more effective than the sum of its members. This is abundantly evident in biological systems; swarms of bees and colonies of ants are more effective than their numbers suggest because bees and ants can act in coordination. Synergistic activity in multicomponent biological systems requires information exchange between units and control mechanisms to guide a unit response. Cell aggregates are communities of cells that are organized in a specific three-dimensional architecture. The preferred aggregation pattern within a particular tissue or organ has important consequences with regard to tissue function.
Approaches to Tissue Engineering
Authors: Saltzman W. Mark
Published: November 2020

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.
The Professional Schools
Authors: Keller Morton , Keller Phyllis
Published: November 2020

Meritocracy flourished most luxuriantly in Harvard’s professional schools. The Big Four—the Graduate School of Arts and Sciences and the Schools of Law, Medicine, and Business—threw off the constraints of lack of money and student cutbacks imposed by World War II. The smaller professional schools—Public Health and Dentistry, Education, Divinity, Design—shared in the good times, though their old problems of scarce resources and conflicted missions continued to bedevil them. The major alteration in the Harvard postgraduate scene was the establishment of the Kennedy School of Government. By the time Derek Bok—as well disposed to the Kennedy School as Conant was to Education and Pusey to Divinity—became president in 1971, this new boy on the Harvard professional school block was well situated to capitalize on his good favor. The Graduate School of Arts and Sciences remained, as in the past, rich in renown, poor in fund-raising and administrative autonomy. Between 1952 and 1962, fewer than 5 percent of GSAS alumni donated a total of about $60,000; during the early sixties giving went down to $3,000 a year. Its dean had little or no budgetary or curricular control; its faculty, curriculum, and student admissions were in the hands of the departments. In 1954 Overseer/Judge Charles Wyzanski grandly proposed that admissions to the Graduate School be sharply cut back. The reduction, he thought, would free up the faculty for more creative thought, improve undergraduate education, and upgrade the level of the graduate student body. But the post–Korean War expansion of American higher education led to boom years for the Graduate School. In 1961, 190 male and 60 female Woodrow Wilson Foundation Fellows, more than a quarter of the national total, chose to go to Harvard or Radcliffe; 80 of 172 National Science Foundation grantees wanted to go to Harvard. A 1969 rating of the nation’s graduate programs gave Harvard Chemistry a perfect 5, Mathematics 4.9, Physics, Biochemistry, Molecular Biology, History, and Classics 4.8, Art History and Sociology 4.7, English and Spanish 4.6, Philosophy and Government 4.5. Impressive enough, all in all, to sustain the faculty’s elevated impression of itself. But in the late sixties the Graduate School bubble deflated. Government aid, foundation fellowships, and college jobs declined; student disaffection grew.
Soil Surveys and Archaeology
Authors: Holliday Vance T.
Published: November 2020

Soil survey and mapping is one of the most fundamental and best-known applications of pedology. The preparation of soil maps began in the 19th century (Yaalon, 1997), but systematic county-based soil surveys began in the 20th century in the United States (Simonson, 1987, p. 3). The production of soil maps based on systematic soil surveys has been one of the primary driving forces in pedologic research in both academic and governmental settings in the United States and worldwide through much of the 20th century (Simonson, 1987, 1997; Yaalon and Berkowicz, 1997). For example, soil survey and mapping has been a primary function of the USDA since 1899 (Simonson, 1987, p. 3; Soil Survey Division Staff, 1993, p. 11). Soil maps have been prepared for a variety of uses at scales ranging from a few hectares to those of continental and global magnitude. Published soil surveys contain a wealth of data on landscapes as well as soils, but are generally an underused (and likely misunderstood) resource in geoarchaeology, probably because of their agricultural and land-use orientation. This chapter presents a discussion of what soil surveys are (and are not) and potential as well as realized applications in archaeology. Much of the discussion focuses on the county soil surveys published by the USDA because they are so widely available, although applications of other kinds and scales of soil maps that have been applied in archaeology or that have archaeological applications also are discussed. Many countries in the world have national soil surveys whose primary mission is the mapping and inventorying of the nation’s soil resource. In the United States, soil survey is a cooperative venture of federal agencies, state agencies (including the Agricultural Experiment Stations), and local agencies, coordinated by the National Cooperative Soil Survey (Soil Survey Division Staff, 1993, p. 11). The principal federal agency involved in soil survey is the National Resource Conservation Service (NRCS; formerly the Soil Conservation Service, SCS) of the USDA. The mapping of soils by the NRCS/USDA is probably the agency’s best-known activity. Its many published county soil surveys are its most widely known and widely used product.
Hurricane Impacts in New England and Puerto Rico
Authors: Boose Emery R.
Published: November 2020

Hurricanes have a profound effect on many coastal ecosystems. Direct impacts often include wind damage to trees, scouring and flooding of river channels, and salt-water inundation along shorelines (Simpson and Riehl 1981; Diaz and Pulwarty 1997). In some areas, secondary impacts may include landslides triggered by heavy rains (Scatena and Larson 1991) or catastrophic dry-season fires resulting from heavy fuel loading (Whigham in press). This chapter will focus on the longterm impacts of hurricane wind damage at two LTER sites, the Harvard Forest (HFR) in central New England and the Luquillo Experimental Forest (LUQ) in northeastern Puerto Rico. These two sites, both located in the North Atlantic hurricane basin and occasionally subject to the same storms, provide interesting examples of tropical and temperate hurricane disturbance regimes. Wind damage from a single hurricane is often highly variable (Foster 1988). Damage to individual trees can range from loss of leaves and fine branches, which can significantly alter surface nutrient inputs (Lodge et al. 1991), to bole snapping or uprooting, which can significantly alter coarse woody debris and soil microtopography (Carlton and Bazzaz 1998a and b). At the stand level, damage can range from defoliation to individual tree gaps to extensive blowdowns, creating different pathways for regeneration (Lugo 2000). At landscape and regional levels, complex patterns of damage are created by the interaction of meteorological, topographic, and biological factors (Boose et al. 1994). Adding to this spatial complexity is the fact that successive hurricanes are not necessarily independent in terms of their effects. A single storm lasting several hours may have effects that persist for decades (Foster et al. 1998). And forest susceptibility to wind damage is strongly influenced by composition and structure, which in turn are strongly influenced by previous disturbance history (Foster and Boose 1992). Thus, the impacts of a single hurricane may depend in part on the impacts of earlier storms as well as on other previous disturbances and land use. Hurricanes, like other disturbances, both create and respond to spatial heterogeneity (Turner et al. 2003). To understand the long-term ecological role of hurricanes at a given site, we must consider these three sets of questions: (1) What is the hurricane disturbance regime?
Synthesis and Characterization of Polymers: From Polymeric Micelles to Step-Growth Polymerizations
Authors: Young Jennifer L. , DeSimone Joseph M.
Published: November 2020

The benefits of using CO2 in polymer synthesis are numerous, ranging from environmental responsibility to improved materials properties. Carbon dioxide is an inert, nontoxic, nonflammable, and inexpensive reaction and processing medium that is an environmentally benign alternative to the organic solvents or water typically used today. Although the often toxic, carcinogenic, and environmentally hazardous organic solvents are recycled, some release to the environment is inevitable. Replacement of organic solvents with water still requires the costly purification of the wastewater prior to disposal and/or an energy-intensive drying process to remove the water. On the other hand, CO2 can be easily separated from other chemical components and recycled through depressurization and recompression. Although CO2 is a greenhouse gas, the CO2 used as a solvent does not contribute to the greenhouse gases since it is acquired from natural reservoirs or recovered as a by-product from other industrial chemical processes. The more specific environmental benefits of using liquid or supercritical carbon dioxide as a solvent vary depending on the polymerization being considered. The synthesis of fluoropolymers in CO2 is of particular interest since these polymers have historically been prepared in chlorofluorocarbons (CFCs) and other fluorinated solvents, as well as in water. Due to the association of CFCs with ozone-layer depletion, these solvents have been banned and replacement solvents must be found. Alternative fluorinated solvents are expensive and also have environmental concerns. In heterogeneous polymerizations, many polymer latexes produced by emulsion or dispersion polymerization in water or organic solvents can be produced in CO2. To eliminate volatile organic compound (VOC) emissions, more polymer latexes are being synthesized in water. However, for dry polymer applications, the latexes must undergo energy-intensive drying by vacuum or heat to remove the water. For polymer latexes produced in CO2, there are no VOC emissions and the energy-intensive drying step can be significantly reduced since the CO2 has a much lower heat of vaporization in the liquid state and, in fact, has a zero heat of vaporization in the supercritical state. Additionally, the polymer can be shipped dry at 100% solids, thus saving energy and money in shipping the heavy water latex.
Dry Cleaning with Liquid Carbon Dioxide
Authors: Stewart Gina
Published: November 2020

The process of cleaning one item invariably involves making something else dirty. Whether that something else is an organic or halogenated solvent, soapy water, or a rag, we seldom address the dirtying that accompanies any cleaning process. If we are to achieve environmentally benign cleaning, we must look at the life cycle of solvents employed for cleaning, including the potential for recycling, reuse, or release into the environment. Truly “green” cleaning processes not only minimize the amount of waste generated; but also they prevent the dispersal of that waste into large amounts of solvent, water, soil, or air. Dense-phase carbon dioxide is a great cleaning solvent from a pollution-prevention viewpoint. By-product CO2 generated by other industrial processes can be captured, so it is not necessary to generate CO2 specifically for cleaning. Spills of CO2 will not contaminate groundwater or create a need for soil remediation. Carbon dioxide even has advantages for the work environment, since no chronic, harmful effects are known from repeated inhalation of low concentrations of CO2. The barriers to using CO2 as a cleaning solvent have centered around two issues: the expense of high-pressure equipment and the poor solubility of many contaminants in CO2. Micell Technologies, Inc., based in Raleigh, NC, has addressed the equipment issue by using liquid CO2 just below ambient temperature (∼18–22 °C) and vapor pressure (∼50 bar). The equipment needed to contain this pressure is considerably less expensive than that needed for supercritical CO2 processes. As for the second barrier, Micell has surfactant packages that enhance the ability of CO2 to dissolve many contaminants commonly found on clothes or on metal parts. Micell is in the process of designing and bringing to market integrated CO2 solutions, including equipment and appropriate chemistries, to replace the organic solvents or water traditionally used in garment dry cleaning, metal degreasing, and textile processing. Dry cleaning is a bit of a misnomer, in that clothes are cleaned in a liquid solvent. “Dry” simply means that exposure of a garment, such as a wool suit or silk blouse, to water is minimized to prevent damage to hydrophilic fibers.
Recovery and Reconstruction of A.L. 444-2
Authors: Kimbel William H. , Rak Yoel , Johanson Donald C. , Holloway Ralph L. , Yuan Michael S.
Published: November 2020

The A.L. 444-2 skull was found on 26 February 1992, during a strategic paleontological survey of Kada Hadar Member sediments that are stratigraphically situated between BKT-1 and BKT-2 tephras, on the eastern edge of the Awash River’s Kada Hadar tributary. Yoel Rak discovered two fragments of hominin occipital bone (A.L. 444-1) at the base of a steep hill composed of Kada Hadar Member silts and clays capped by a weathered sandstone remnant. Subsequent examination of the upslope surface revealed additional hominin skull fragments (the temporal bones and maxillae) clustered together and partially exposed in a narrow gully that dissected the face of the hill. During the next seven days, probing and dry sieving of the gully infill and hillside colluvium over a 77 m2 area led to the recovery of fragments representing about 75%–80% of a single hominin skull. It was immediately apparent that the upslope finds duplicated the anatomical parts represented by the two A.L. 444-1 occipital fragments and therefore constituted a second hominin individual, cataloged as A.L. 444-2. In addition, the lambdoidal suture of the A.L. 444-1 occipital is completely unfused, suggesting subadult status, whereas fused cranial sutures and extreme dental occlusal wear indicate an advanced ontogenetic age for A.L. 444-2. In February–March 1993 the A.L. 444 hillside was excavated in an effort to locate missing parts of the A.L. 444-2 skull and to determine its precise stratigraphic provenance. No further remains of the hominin skull were encountered in situ, but a complete viverrid cranium and indeterminate fragments of large mammal bone with preservation and patina (mottled dark gray, white, and yellowish gray) identical to those of the hominin were excavated in an unstratified, cemented carbonate silt that exactly matches the matrix adhering to A.L. 444-2. We are confident that the hominin skull is from this sedimentary horizon. It is approximately 10.5 m stratigraphically below the BKT-2 tephra, which outcrops in the immediate vicinity of A.L. 444 Single-crystal laser fusion (SCLF) 40Ar/39Ar ages for BKT-2 and Kada Hadar Tuff (KHT) bracket the geological age of A.L. 444-2 between 2.94 and 3.18 Myr (Kimbel et al., 1994; Walter, 1994; Semaw et al., 1997).
Education for Peace: The Role of Universities
Authors: Hamburg David A. , Hamburg Beatrix A.
Published: November 2020

This chapter emphasizes the potential leadership functions of universities in this field. They can (1) heighten awareness of the gravity of the problem, especially by international cooperation in sharing data; (2) conduct research with emphasis on interdisciplinary collaboration that gives deeper understanding of causes, nature and scope, amelioration, and prevention of mass violence; (3) upgrade education for peace in the universities and also extend the reach to educate the general public and leaders, including political, religious, ethnic, and military leaders—all of whom have massive responsibility for preventing catastrophes rather than inducing them; and (4) program excellent developmentally-appropriate educational materials for elementary and secondary schools, working in conjunction with teachers at each level. In March 2001, an international group of experts from various fields met to discuss the current status of education for peace and ways to improve it. Scholars from academia, prominent UN officials, and experts from nongovernmental, governmental, and multilateral organizations considered ways in which the University for Peace (UPEACE) might be able to strengthen the field of peace education.More broadly, participants analyzed the current state of peace education internationally. All concurred that the concerns posed by human conflict in the twenty-first century must be more adequately addressed. This initial section outlines important issues raised at the conference as well as its recommendations. In opening this meeting at the United Nations, Kofi Annan, UN Secretary General, made these remarks:… Knowledge, research, and teaching are vital in our new global environment. To achieve effective education for peace, we need to reach out to as many actors as possible to devise new approaches to challenges that are in themselves only beginning to be fully understood. . . . How do we promote the good governance needed to underpin stable and transparent societies? How do we make the unprecedented opportunities offered by science and technology work as a tool for peace? . . . Achieving decent, just, and peaceful relations among diverse human groups is an enterprise that must be constantly renewed—and education for peace is a fundamental part of that enterprise. Yet the world’s record on education for peace has been weak indeed. . . . To address complex causes, we need complex, interdisciplinary solutions.
Generalized Nonadditive Information Theory and Quantum Entanglement
Authors: Abe Sumiyoshi
Published: November 2020

Nonadditive classical information theory is developed in the axiomatic framework and then translated into quantum theory. The nonadditive conditional entropy associated with the Tsallis entropy indexed by q is given in accordance with the formalism of nonextensive statistical mechanics. The theory is applied to the problems of quantum entanglement and separability of the Werner-Popescu-type mixed state of a multipartite system, in order to examine if it has any points superior to the additive theory with the von Neumann entropy realized in the limit q → 1. It is shown that the nonadditive theory can lead to the necessary and sufficient condition for separability of the Werner-Popescu-type state, whereas the von Neumann theory can give only a much weaker condition…. Tsallis' nonextensive generalization of Boltzmann-Gibbs statistical mechanics [3, 15, 16] and its success in describing behaviors of a large class of complex systems naturally lead to the question of whether information theory can also admit an analogous generalization. If the answer is affirmative, then that will be of particular importance in connection with the problem of quantum entanglement and quantum theory of measurement [6, 8], in which necessities of a nonadditive information measure and an information content are suggested. One should also remember that there exists a conceptual similarity between a complex system and an entangled quantum system. In these systems, a "part" is indivisibly connected with the rest. An external operation on any part drastically influences the whole system, in general. Thus, the traditional reductionistic approach to an understanding of the nature of such a system may not work efficiently. In this chapter, we report a recent development in nonadditive quantum information theory based on the Tsallis entropy indexed by q [15] and its associated nonadditive conditional entropy [1]. This theory includes the ordinary additive theory with the von Neumann entropy in a special limiting case: q → To see if it has points superior to the additive theory, we apply it to the problems of separability and quantum entanglement.