bluuebunny/crossref_metadata_2025 huggingface dataset:
Factor Xa Inhibitors
Authors: Becker Richard C. , Spencer Frederick A.
Published: November 2020

The importance of factor Xa in the initiation and propagation of coagulation, as well as its pluripotential cellular properties, has been discussed previously. Considered collectively, the effects exhibited by this particular protease make it an attractive target for pharmacologic inhibition. Factor Xa inhibition can be classified and subcategorized as follows: indirect (antithrombin [AT]-dependent), nonselective (e.g., unfractionated heparin); indirect, semi-selective (e.g., low-molecular-weight heparin); indirect, selective (e.g., fondaparinux); and direct, selective (e.g., DX-9065a [in early stage of development]). Oral factor Xa inhibitors are in phase II testing. Fondaparinux (Arixtra) is a synthetic pentasaccharide that requires AT for selective fXa binding (Petitou et al., 1991). Unlike heparin compounds, fondaparinux does not inhibit thrombin directly nor does it interact with platelets (or platelet-derived proteins). After subcutaneous administration in healthy volunteers, fondaparinux was nearly 100% bioavailable, and absorption was rapid (Cmax within 2 hours) (Donat et al., 2002). Clearance is through renal mechanisms with a terminal halflife of 17 ± 3 hours (slightly longer in elderly volunteers). Overall, drug clearance is 25% lower in patients with mild renal impairment (creatinine clearance [CrCl] 50–80 mL/min), approximately 40% lower in patients with moderate renal impairment (CrCl 30–50 mL/min), and 55% lower in patients with severe renal impairment (CrCl <30 mL/min). OASIS-5, the largest trial performed to date in non-ST segment elevation acute coronary syndromes (ACS), randomized 20,078 patients to fondaparinux (2.5 mg subcuaneous once daily) or enoxaparin (1 mg/kg twice daily) for 2 to 8 days. The primary outcome (composite of death, MI, and refractory ischemia on day 9) was 5.9% and 5.8%, respectively. Major bleeding rates were 2.1% and 4.0%, respectively (hazard ratio 0.53; p<.001). By 6-month follow-up, the endpoints of death, death/MI, stroke, and composite of death/MI/stroke were significantly reduced in those receiving fondaparinux. Catheter thrombosis (during PCI) was 3-fold higher in fondaparinux-treated patients compared to those receiving enoxaparin (1.3% vs. 0.5%, respectively) (European Society of Cardiology presentation, September 2005). The clinical use of fondaparinux for venous thromboembolism prophylaxis will be discussed in Chapter 22.
Contact, Intergroup Relations, and Opportunities for Education
Authors: Hamburg David A. , Hamburg Beatrix A.
Published: November 2020

If groups are strange to each other and therefore fearful or hostile, why not bring them together so they can get to know each other and become friendly? This plausible approach is more complicated than it looks at first glance. Under what conditions will intergroup contact be helpful? Can it sometimes be harmful? A variety of field and laboratory experiments support the hypothesis that intergroup competition tends to strengthen social relations within each group and to disrupt relations between the groups. If the experiments are arranged in a way that deliberately fosters competition between the groups, these effects are heightened. But even in the absence of such direct instruction or arrangement, potent factors favor interpersonal attraction or mutual attachment within a group: frequency of social interaction, proximity to each other, familiarity, and similarity of attitudes and values. Almost any sort of interaction within a group tends to promote in-group favoritism. Actually, it seems rather difficult to avoid this effect even if one tries to do so. Humans are highly susceptible to invidious in-group/out-group distinctions. Extensive experimental work strongly confirms the rich variety of observations from fieldwork in many cultures over extended times and in a variety of societies. This does indeed seem to be a profound and pervasive human characteristic—one of great practical significance throughout history. We will return to this theme and examples throughout the book. Findings of this sort have led some psychologists to formulate a principle of social identity, which emphasizes the powerful effects of social categorization in its own right. Such categorization seems to highlight an important aspect of the individual self-concept (and self-esteem) based on group membership. Such membership has, from the evolutionary and historical record, been an important feature in human survival over the millennia. In contemporary people—at least, in those who participate in psychological experiments—the cognitive delineation into an in-group and out-group, even without invidious attributions, tends to set in motion a process by which there is an accentuation of similarities within groups and differences between groups. It seems very convenient, easy, and somehow natural for people to deal with these via simple schemas or stereotypes.
Information Technology: Its Potential to Educate for Peace
Authors: Hamburg David A. , Hamburg Beatrix A.
Published: November 2020

In this chapter, we are mainly interested in ways that use of the Internet can promote helpful, legitimate, and practical support to teachers, students, and others interested in education for peace, conflict resolution, and violence prevention. The World Wide Web, a powerful global network, has immense capacity to influence people (especially children) that can be compared to the influence of television. Research that has been done on television viewing shows that it can have positive and negative effects on behavior beginning in early childhood. It does not affect everyone in the same way—variables such as age, socioeconomic status, and identification with television characters all play significant roles in how content affects a child. The Internet and other interactive media are similar to television by way of underlying factors (such as observational learning, attitudes, and arousal) that influence behavior. Over the past several decades, some of the most profound changes in the way we live have come from the revolution in information technology (IT). A wide range of technologies has not only made it easier to communicate but also to send and utilize information. These devices have not stayed in the province of institutions or specialists but have found their way into common use. From cell phones and personal digital assistants to computers (just to touch on some of the most common of these technologies), they have changed the way ordinary people interact and behave. Their effects have been profound, as reflected in the speed with which these technologies have evolved and insinuated themselves into everyday life. Perhaps the most important of these technologies is the personal computer (PC). In itself, the rise of the PC was a dramatic event, allowing more people to apply the capabilities of the computer to small business, personal activity, and schoolwork. But in the past decade, other information technologies that utilize the PC, the most important of which are the World Wide Web and electronic mail (e-mail), have appeared and promise further large-scale uses.
Theory and Quantitative Predictions
Authors: Wei James
Published: November 2020

The purpose of this chapter is to review the theories of molecular structure and property relations, to discuss computational methods for prediction of molecular structure and properties, and to discuss some of the properties that can be predicted by computations. Quantum mechanics is the foundation of molecular structure and properties. The position and energy of the electrons around a molecule are determined by solving the Schrödinger equation for a given set of positions of the nuclei of the atoms. There is a lot of powerful and effective computer software that can be used to calculate many of the properties of an isolated single molecule, especially at zero absolute temperature. The starting point is the construction of the sketch of a molecule by connecting atoms with the appropriate bonds. This qualitative sketch does not need accurate values for the bond lengths and angles. To set up the computation, the investigator specifies one of three computation methods: ab initio, semi-empirical, or molecular mechanics. The first and second methods are based on quantum mechanics about a model of the molecule as a number of negatively charged electrons surrounding a collection of positively charged nuclei. The third option of molecular mechanics is based on classical Newtonian mechanics about a model of the molecule as a number of mechanical bonds linking the atoms together, and these bonds can be stretched and bent according to empirical force fields. When either the Schrödinger equation or the Newtonian equation is solved with the initial spatial distribution of nuclei, in what is called the single-point determination, the binding energy of the molecule is obtained. If we make random perturbations of the positions of the various atoms, and repeat the single-point calculations, we can map the energy levels of the molecule in a neighborhood. The most stable or equilibrium position of the molecule is the one with the lowest energy in the neighborhood, and the search for this equilibrium position of the atoms is called geometry optimization. The most rigorous and accurate method of calculation is the ab initio method, which is also the most demanding in computational time and resources, so that it is most often used for smaller molecules.
Extinction In The Fossil Record
Authors: Newman M. E. J. , Palmer R. G.
Published: November 2020

Of the estimated one to four billion species that have existed on the Earth since life first appeared here (Simpson 1952), less than 50 million are still alive today (May 1990). All the others became extinct, typically within about ten million years (My) of their first appearance. It is clearly a question of some interest what the causes are of this high turnover, and much research has been devoted to the topic (see, for example, Raup (1991a) and Glen (1994) and references therein). Most of this work has focussed on the causes of extinction of individual species, or on the causes of identifiable mass extinction events, such as the end-Cretaceous event. However, a recent body of work has examined instead the statistical features of the history of extinction, using mathematical models of extinction processes and comparing their predictions with global properties of the fossil record. In this book we will study these models, describing their mathematical basis, the extinction mechanisms that they incorporate, and their predictions. Before we start looking at the models however, we need to learn something about the trends in fossil and other data which they attempt to model. This is the topic of this introductory chapter. Those well versed in the large-scale patterns seen in the Phanerozoic fossil record may wish to skip or merely browse this chapter, passing on to chapter 2, where the discussion of the models begins. There are two primary colleges of thought about the causes of extinction. The traditional view, still held by most palaeontologists as well as many in other disciplines, is that extinction is the result of external stresses imposed on the ecosystem by the environment (Benton 1991; Hoffmann and Parsons 1991; Parsons 1993). There are indeed excellent arguments in favor of this viewpoint, since we have good evidence for particular exogenous causes for a number of major extinction events in the Earth's history, such as marine regression (sealevel drop) for the late-Permian event (Jablonski 1985; Hallam 1989), and bolide impact for the end-Cretaceous (Alvarez et al. 1980; Alvarez 1983, 1987).
Summary
Authors: Newman M. E. J. , Palmer R. G.
Published: November 2020

In this book we have studied a large number of recent quantitative models aimed at explaining a variety of large-scale trends seen in the fossil record. These trends include the occurrence of mass extinctions, the distribution of the sizes of extinction events, the distribution of the lifetimes of taxa, the distribution of the numbers of species per genus, and the apparent decline in the average extinction rate. None of the models presented match all the fossil data perfectly, but all of them offer some suggestion of possible mechanisms which may be important to the processes of extinction and origination. In this chapter we conclude our review by briefly summarizing the properties and predictions of each of the models once more. Much of the interest in these models has focused on their ability (or lack of ability) to predict the observed values of exponents governing distributions of a number of quantities. In Table 7.1 we summarize the values of these exponents for each of the models. Most of the models we have described attempt to provide possible explanations for a few specific observations. (1) The fossil record appears to have a power-law (i.e., scale-free) distribution of the sizes of extinction events, with an exponent close to 2 (section 1.2.2.1). (2) The distribution of the lifetimes of genera also appears to follow a power law, with exponent about 1.7 (section 1.2.2.4). (3) The number of species per genus appears to follow a power law with exponent about 1.5 (section 1.2.3.1). One of the first models to attempt an explanation of these observations was the NK model of Kauffman and co-workers. In this model, extinction is driven by revolutionary avalanches. When tuned to the critical point between chaotic and frozen regimes, the model displays a power-law distribution of avalanche sizes with an exponent of about 1. It has been suggested that this could in turn lead to a power-law distribution of the sizes of extinction events, although the value of 1 for the exponent is not in agreement with the value 2 measured in the fossil extinction record.
Nonextensive Entropies and Sensitivity to Initial Conditions of Complex Systems
Authors: Lyra Marcelo L.
Published: November 2020

Tsallis generalized statistics has been successfully applied to describe some relevant features of several natural systems exhibiting a nonextensive character. It is based on an extended form for the entropy, namely Sq = (1 — ΣqpQq)/(Q —1), where q is a parameter that measures the degre of nonextensivity (q→1 for the traditional Boltzmann-Gibbs statistics). A series of recent works have shown that the power-law sensitivity to initial conditions in a complex state provides a natural link between the g-entropic parameter and the scaling properties of dynamical attractors. These results contribute to the growing set of theoretical and experimental evidences that Tsallis statistics can be a natural frame for studying systems with a fractal-like structure in phase space. Here, the main ideas underlying this relevant aspect are reviewed. The starting point is the weak sensitivity to initial conditions exhibited by low-dimensional dynamical systems at the onset of chaos. It is shown how general scaling arguments can provide a direct relation between the entropic index q and the scaling exponents associated with the multifractal critical attractor. These works shed light in the elusive problem concerning the connection between the g-entropic parameter of Tsallis statistics and the underlying microscopic dynamics of nonextensive systems.... Inspired on the scaling properties of multifractals, Tsallis introduced a generalized entropy with the aim of extending the usual statistical mechanics and thermodynamics [37].
A Dripping Faucet as a Nonextensive System
Authors: Penna T. J. P. , Sartorelli J. C.
Published: November 2020

Here we present our attempt to characterize a time series of drop-to-drop intervals from a dripping faucet as a nonextensive system. We found a long-range anticorrelated behavior as evidence of memory in the dynamics of our system. The hypothesis of faucets dripping at the edge of chaos is reinforced by results of the linear rate of the increase of the nonextensive Tsallis statistics. We also present some similarities between dripping faucets and healthy hearts…. Many systems in Nature exhibit complex or chaotic behaviors. Chaotic behavior is characterized by short-range correlations and strong sensitivity to small changes of the initial conditions. Complex behavior is characterized by the presence of long-range power-law correlations in its dynamics. In the latter, the sensitivity to a perturbation of the initial condition is weaker than in the former. Because the probability densities are frequently described as inverse power laws, the variance and the mean often diverge. Although it is hard to predict the long-term behavior of such systems, it is still possible to get some information from them and even to find similarities between two apparently very distinct systems. Tools from statistical physics are frequently used because the main task here is to deal with diverse macroscopic phenomena and to try to explain them, starting with the microscopic interactions among many individual components. The microscopic interactions are not necessarily complicated, but the collective behavior can determine a rather intricate macroscopic description. Nonextensive statistical mechanics, since its proposal in 1988 [27], has been applied to an impressive collection of systems in which spatial or temporal longrange correlations appear. Hence, it can also become a useful tool to characterize such systems. Here, we present an attempt of using such formalism to try to understand the intriguing behavior of an apparently simple system: a dripping faucet.
The Living State of Matter: Between Noise and Homeorrhetic Constraints
Authors: Buiatti Marcello , Bogani Patrizia
Published: November 2020

The living state of matter, while obviously obeying physical and chemical laws, does exhibit some peculiar features which, taken altogether, distinguish it from the rest of the natural world. As discussed at length elsewhere [16, 18], these include, among others, hierarchical organization, individuality, invention, and homeostasis. One key category which was introduced by Waddington [94] is homeorrhesis. Homeorrhesis is the dynamical version of homeostasis and it may be defined as the capacity of living systems to maintain their harmonic dynamical networks through continuous change in response to external and internal noise. In the present chapter, we will discuss, in the light of recent interdisciplinary data, the relationship between noise and self-organization. We propose, as a new feature specific to living systems, the capacity to integrate into flexible and versatile networks a portion of noise of internal and external origin (correlated information), and to utilize it to counteract the disrupting effect of the remaining noise. The analysis will be carried out at the levels of DNA and of organized networks, and will also be tackling the problem from the point of view of the relationship between increases in organismal complexity and entropy levels at the evolutionary scale…. Present-day genomes are the results of evolution, and DNA may be considered as an archive of past events. We use as a working hypothesis the almost unanimously accepted concept of interplay between selection as it fixes "useful" sequences, and mutation-genetic drift forces as they generate noise and continuously shuffling of genomes. Studies on structure and function of genomes have been increasing at a very fast rate following the extraordinary progress in sequencing techniques and, consequently, in GenBank whole genome sequences are available of a number of bacteria, Archaea, viruses, and eukaryotes. DNA content per cell has been increasing during evolution, more recent species having, in general, larger genomes than ancestral ones. This, however, is only a rough approximation of reality. A better analysis of the data tells us that while prokaryotes (bacteria and Archaea) have small genomes ranging from 500,000 base pairs (bp) to 5 million bp, an abrupt increase has occurred in eukaryotes. In this large group, a unicellular organism like Saccharomyces cerevisiae has a 12-million-bp genome, while multicellular organisms range from around 100 million to several billion bp.
Theories of Communication Networks
Authors: Monge Peter R. , Contractor Noshir
Published: November 2020

To date, most network research contains one or more of five major problems. First, it tends to be atheoretical, ignoring the various social theories that contain network implications. Second, it explores single levels of analysis rather than the multiple levels out of which most networks are comprised. Third, network analysis has employed very little the insights from contemporary complex systems analysis and computer simulations. Foruth, it typically uses descriptive rather than inferential statistics, thus robbing it of the ability to make claims about the larger universe of networks. Finally, almost all the research is static and cross-sectional rather than dynamic. Theories of Communication Networks presents solutions to all five problems. The authors develop a multitheoretical model that relates different social science theories with different network properties. This model is multilevel, providing a network decomposition that applies the various social theories to all network levels: individuals, dyads, triples, groups, and the entire network. The book then establishes a model from the perspective of complex adaptive systems and demonstrates how to use Blanche, an agent-based network computer simulation environment, to generate and test network theories and hypotheses. It presents recent developments in network statistical analysis, the p* family, which provides a basis for valid multilevel statistical inferences regarding networks. Finally, it shows how to relate communication networks to other networks, thus providing the basis in conjunction with computer simulations to study the emergence of dynamic organizational networks.
Communication and Knowledge Networks as Complex Systems
Authors: Monge Peter R. , Contractor Noshir
Published: November 2020

The concept of a system has a long and distinguished history in the social sciences. In fact, Mattelart and Mattelart (1998) claim that “the idea of society as an organism, that is, a whole composed of organs performing predetermined functions, inspired the earliest conceptions of a ‘science of communication’”. We begin this chapter with a brief historical overview of the major systems perspectives that have been utilized in social theory and research: structural-functionalism, cybernetics, and general systems theory. We then apply recent developments in complex systems theories to organizational networks. In doing so, we look at communication and knowledge networks from the perspective of agent-based modeling and self-organizing systems. Mattelart and Mattelart (1998) trace the early growth of systems thinking in the social sciences. Adam Smith’s (1776) classic work, The Wealth of Nations, postulated that a laissez-faire system, the division of labor, and channels of communication and transportation were crucial aspects of economic prosperity. The key to economic and therefore social success was the unrestricted circulation of messages, materials, and money through secure networks. According to Mattelart and Mattelart (1998), Francois Quesnay, a French physician and economist, published an economic chart (tableau economique) in 1758. “The chart offers a macroscopic vision of an economy of ‘flows’ in the form of a geometrical zigzag figure in which the lines expressing exchange between human beings and the land, as well as among the three classes making up society, cut across each other and become intertwined”. The Mattelarts note that Claude Henri de Saint Simon’s eighteenth-century work also applied systems theory to the concept of networks. Saint-Simons’s theory conceived of society as “an organic system, a bundle or fabric of networks.... He attributed strategic importance to the development of a system of communication routes”. Out of this background Herbert Spencer (1820–1903) developed the first integrated theory of society built on a direct analogy with biological systems.
Biogeochemistry of Estuaries
Authors: Bianchi Thomas S.
Published: November 2020

Biogeochemistry of Estuaries offers a comprehensive and interdisciplinary approach to understanding biogeochemical cycling in estuaries. Designed as a text for intermediate to advanced students, this book utilizes numerous illustrations and an extensive literature base to impart the current state-of-the-art knowledge in this field. While many of the existing books in estuarine science are comprised of edited volumes, typically focused on highly specific topics in estuaries,Biogeochemistry of Estuaries provides, for the first time, a unique foundation in the areas of geomorphology, geochemistry, biochemistry, aqueous chemistry, and ecology, while making strong linkages (trhoughout the text) to ecosystem-based processes in estuarine sciences. Estuaries, located at the interface between land and the coastal ocean are dynamic, highly productive systems that, in many cases, have been historically associated with development of many of the great centers of early human civilization. Consequentially, these systems have and continue to be highly impacted by anthropogenic inputs. This timely book takes the foundational basis of elemental cycling in estuarine and applies it to estuarine management issues. Biogeochemistry of Estuaries will be welcomed by estuarine/marine scientists, ecologists, biogeochemists, and environmentalists around the world.
Origin and Geomorphology
Authors: Bianchi Thomas S.
Published: November 2020

Geologically speaking, estuaries are ephemeral features of the coasts. Upon formation, most begin to fill in with sediments and, in the absence of sea level changes, would have life spans of only a few thousand to tens of thousands of years (Emery and Uchupi, 1972; Schubel, 1972; Schubel and Hirschberg, 1978). Estuaries have been part of the geologic record for at least the past 200 million years (My) BP (before present; Williams, 1960; Clauzon, 1973). However, modern estuaries are recent features that only formed over the past 5000 to 6000 years during the stable interglacial period of the middle to late Holocene epoch (0–10,000 y BP), which followed an extensive rise in sea level at the end of the Pleistocene epoch (1.8 My to 10,000 y BP; Nichols and Biggs, 1985). There is general agreement that four major glaciation to interglacial periods occurred during the Pleistocene. It has been suggested that sea level was reduced from a maximum of about 80 m above sea level during the Aftoninan interglacial to 100 m below sea level during the Wisconsin, some 15,000 to 18,000 y BP (figure 2.1; Fairbridge, 1961). This lowest sea level phase is referred to as low stand and is usually determined by uncovering the oldest drowned shorelines along continental margins (Davis, 1985, 1996); conversely, the highest sea level phase is referred to as high stand. It is generally accepted that low-stand depth is between 130 and 150 m below present sea level and that sea level rose at a fairly constant rate until about 6000 to 7000 y BP (Belknap and Kraft, 1977). A sea level rise of approximately 10 mm y−1 during this period resulted in many coastal plains being inundated with water and a displacement of the shoreline. The phenomenon of rising (transgression) and falling (regression) sea level over time is referred to as eustacy (Suess, 1906). When examining a simplified sea level curve, we find that the rate of change during the Holocene is fairly representative of the Gulf of Mexico and much of the U.S. Atlantic coastline (Curray, 1965).
Physical Properties and Gradients
Authors: Bianchi Thomas S.
Published: November 2020

Before discussing the chemical dynamics of estuarine systems it is important to briefly review some of the basic principles of thermodynamic or equilibrium models and kinetics that are relevant to upcoming discussions in aquatic chemistry. Similarly, the fundamental properties of freshwater and seawater are discussed because of the importance of salinity gradients and their effects on estuarine chemistry. Stumm and Morgan (1996) described how different components of laboratory- and field-based measurements in aquatic chemistry are integrated. Basically, observations from laboratory experiments are made under well-controlled conditions (focused on a natural system of interest), which can then be used to make predictions and models, which are ultimately used to interpret complex patterns in the natural environment. Due to the complexity of natural systems, equilibrium models can tell you something about how chemical constituents (gases, dissolved species, solids) under well-constrained conditions (no change over time, fixed temperature and pressure, and homogeneous distribution of constituents). Equilibrium models will tell you something about the chemistry of the system at equilibrium but will not tell you anything about the kinetics with which the system reached equilibrium state. The laws of thermodynamics are the foundation for chemical systems at equilibrium. The basic objectives in using equilibrium models in estuarine/aquatic chemistry is to calculate equilibrium compositions in natural waters, to determine the amount of energy needed to make certain reactions occur, and to ascertain how far a system may be from equilibrium (Stumm and Morgan, 1996). The first law of thermodynamics states that energy cannot be created or destroyed (i.e., the total energy of a system is always constant). This means that if the internal energy of a reaction increases then there must be a concomitant uptake of energy usually in the form of heat. Enthalpy (H) is a parameter used to describe the energy of a system as heat flows at a constant pressure; it is defined by the following equation: . . . H = E + PV (4.1) . . . where: E = internal energy; P = pressure; and V = volume.
Organic Matter Cycling
Authors: Bianchi Thomas S.
Published: November 2020

In this chapter the general processes involved in controlling production and transformation of organic matter will be discussed as well as some of the associated stoichiometric changes of a few key biological elements (e.g., C, N, P, S). Stoichiometry is defined as the mass balance of chemical reactions as they relate to the law of definite proportions and conservation of mass (Sterner and Elser, 2002). For example, if we examine the average atomic ratios of C, N, and P in phytoplankton we see a relatively consistent ratio of 106:16:1 in most marine species. This is perhaps the best example of applied stoichiometric principles in natural ecosystems and is derived from the classic work of Alfred C. Redfield (1890–1983) (Redfield, 1958; Redfield et al., 1963). More specifically, Redfield compared the ratios of C, N, and P of dissolved nutrients in marine waters to that of suspended marine particulate matter (seston) (essentially phytoplankton) and found straight lines with equal slopes (figure 8.1; Redfield et al., 1963). This relationship suggested that marine biota were critical in determining the chemistry of the world ocean, clearly one of the most important historical findings linking chemical and biological oceanography (Falkowski, 2000). Moreover, the Redfield ratio has been further validated with recent data using improved analytical techniques (Karl et al., 1993; Hoppema and Goeyens, 1999). Other work has shown that there are predictable deviations from the Redfield ratio across a freshwater to open ocean marine gradient (figure 8.2; Downing, 1997). For example, N-to-P ratios in estuaries have commonly been shown to be lower and/or higher than the predicted Redfield ratio because of denitrification and anthropogenic nutrient enrichment processes, respectively. Inputs of vascular plant organic matter (e.g., mangroves, salt marshes, seagrasses) to estuarine systems presents another problem in causing deviations of C:N:P from the Redfield ratio. Vascular plants have been shown to deviate from this ratio in part because of relatively high amounts of C and N compared to algae due to a higher abundance of structural support molecules (e.g., cellulose, lignin) and defense antiherbivory (secondary) compounds (e.g., tannins), respectively (Vitousek et al., 1988).
Tourists Along the Nile
Authors: Fagan Brian
Published: November 2020

Until 1830, the traveler to India faced a long, and often stormy, passage around the Cape of Good Hope. The advent of the steamship changed everything. Now you could take a steamer from England or Marseilles to Alexandria, then spend a few days or weeks in Cairo waiting for news that the ship for India was approaching Suez. You then took a camel, horse, or wagon across the desert to meet the vessel at what was then a small village. Hotels opened in Suez and Cairo to accommodate transit passengers. The British Hotel in Cairo, soon to be renamed Shepheard’s Hotel after its manager, welcomed its first guests in 1841. This magnificent Victorian institution became world famous, especially after the opening of the Suez Canal in 1869, when it became the hotel of choice for the British Raj on its way to and from India. The hotel also catered to a new breed, the archaeological tourist. Bubonic plague epidemics periodically claimed thousands of lives in Egypt until 1844, when it suddenly and mysteriously disappeared. Cholera arrived from India to take its place, but despite this scourge, Egypt became a recommended destination for travelers wishing to escape damp European winters. By this time, a journey up the Nile to the First Cataract was routine, although one had to endure long quarantines on account of the plague. Nile travel became so popular that the London publisher John Murray commissioned the Egyptologist John Gardner Wilkinson to write a guide, one of a series aimed at a new audience of middle-class tourists.Wilkinson traveled in style, his baggage requiring a small army of porters. The contents of his baggage included an iron bedstead, a sword and other oddities, and “much more,” including a chicken coop, ample biscuits (cookies), and potted meats. He lamented the high cost of living in Egypt and the changes brought by a rising tide of visitors. “The travelers who go up the Nile will I fear soon be like Rhine tourists. & Cheapside will pour out its Legions upon Egypt.” His Handbook for Travellers in Egypt first appeared in 1847, went through multiple editions until 1873, and was still in common use half a century after its first appearance.
Anthropogenic Distribution of Lead
Authors: Powell E. , Gonzales C.
Published: November 2020

In 1980, Clair C. Patterson made an astonishing statement: “Sometime in the near future it probably will be shown that the older urban areas of the United States have been rendered more or less uninhabitable [emphasis added] by the millions of tons of poisonous industrial lead residues that have accumulated in cities during the past century” (NAS 1980). This chapter describes the anthropogenic redistribution of Pb during the twenthieth century from mineral-rich geologic formations to urban locations. It explores the meaning of “more or less uninhabitable” in the context of medical knowledge and presents empirical evidence about the neurotoxic impact of Pb to urban inhabitants, especially children. Of the many lead- (Pb) containing products, Pb-based paint and Pb additives to gasoline contributed the largest quantities of Pb within urban environments. In the U.S., the gross tonnage of white-Pb used as pigment in paint from the late nineteenth century to 1978 was about equal to the amount used in tetra ethyl (and methyl) lead (TEL/TML) additives to gasoline between 1929 and 1986 (Mielke and Reagan 1998).The maximum uses of each of these Pb products occurred in two peaks. The first and lower peak occurred in the 1920s during the use of Pb-based paint when the U.S. economy was about to switch from agrarian to industrial. At that time, rail transportation was the main conveyance for moving goods and providing services, and Pb-based paints were applied to homes in both large and small communities throughout the nation. Pb-based paints remain as thin layers that, when intact, are not bioavailable. However, deterioration or careless removal of Pb-based paint contributes dust that contaminates the local environment with bioavailable Pb (Mielke et al. 2001). The second and higher peak of Pb use occurred with leaded gasoline around 1970 at a time when the U.S. economy was industrial, urban, and relied on automobiles for transportation. In contrast to Pb-based paint coatings, combustion of Pb-gasoline emits particles of dust that are extremely bioavailable. Consequently, the processes that distributed Pb from gasoline are tied to two features of modern cities.
Introduction : Geography of War and Peace
Authors: flint colin
Published: November 2020

According to many, we live in a time of war that was ushered in by the attacks of September 11, 2001. Paradoxically, in the prior three years, between 3.1 and 4.7 million people had been killed in conflict in the Congo alone. Numerous other wars raged across the globe. Clearly, to say that a time of war has emerged only since 9/11 is, on the one hand, ethnocentric and plain wrong. On the other hand, awareness of war among the general population of the Western world emerged after 9/11; perception rather than reality drives commentators to define the current period as one of conflict and not peace. It seems almost certain that the current generation of young adults will grow politically mature in a time when the whole world is aware of war. War has been a prevalent occurrence; in the last few decades one can cite Vietnam, the Falklands, Chechnya, Iran and Iraq, Sierra Leone, Nicaragua, and Kashmir, to name only a few. The attacks of 9/11 were, from a global perspective, just one more horrific instance of human carnage. However, geopolitically, targeting the United States on its own homeland has created significant changes. War, the “hot war” on terrorism rather than the Cold War, is dominating global geopolitical imperatives and the national debates of many countries (the United States, the United Kingdom, Iraq, Iran, North and South Korea, and others). As the sole superpower, the United States has set the agenda. The citizens of the West can no longer ignore and avoid war. Despite its associated horrors, this is also an opportunity: we can become knowledgeable about wars beyond our immediate experiences. Geography is a powerful tool to gain and organize such knowledge. What is war? War takes many forms, from terrorist attacks to interstate conflict. Its form, its scale, its victims, its motives, and its weaponry are varied. But one aspect of war is universal across space and time: war is tyranny. The power of this statement refers to the processes by which people who did not initiate war become cogs in a fighting machine mobilized to defend territory, values, and collective identities from aggression.
Geography and War, Geographers and Peace
Authors: Mamadouh Virginie
Published: November 2020

La géographie, ça sert d’abord à faire la guerre—geography serves, first and foremost, to wage war. Yves Lacoste made this bold statement the title of a pamphlet against French academic geography in the mid-1970s. He not only exposed the historical importance of geographical knowledge in the waging of war and, more generally speaking, the controlling of people and territories, he also attacked academic and school geography for concealing its political and strategic importance. Geography (i.e., the mapping of the world out there) indeed has strong connections to rulers and their attempt to control territories and peoples. On the other hand, geographers have in the past two decades been keen to promote geography as peace studies. This chapter examines the ways in which geographers have dealt with war and peace since the establishment of modern Western academic geography. It addresses both the way in which geographers have conceptualized and studied war and peace processes and the way in which geography has been applied and geographers have been implicated in these very processes. The result is an evaluation of whether geography has been converted from a discipline for war into a discipline for peace, to paraphrase O’Loughlin and Heske. This is done by considering three dimensions for which antagonist positions (war minded versus peace minded) are anticipated: the perception of war (a natural event versus an undesirable collective behavior), the focus of geographical studies that deal with war and peace (functions of war versus causes and consequences of war), and the advocated application of geographical knowledge (to win a war versus to prevent a war and to foster peace). War and peace do not seem to belong to the vocabulary of geography. The terms have no entries in the Dictionary of Human Geography or in the Dictionary of Geopolitics. This is mainly because war and peace are rather vague concepts. In this chapter, a limited conception of war has been chosen: political violence between states, that is, armed conflict. Therefore, the review neglects urban riots, social struggles, and related conflicts.
Geographies of Genocide and Ethnic Cleansing : The Lessons of Bosnia-Herzegovina
Authors: Dahlman Carl
Published: November 2020

The “Serbian Adolf” figures as one of many parallels between the Nazi aggression of World War II and the more recent wars in Bosnia (1992–1995). Though many recognized and drew attention to the atrocities committed against Bosnian civilians, the stories and images of deportation, mass murder, and concentration camps failed to stir an effective response from the international community of states, which had, fifty years before, promised to defend civilians from such abuses. This occurred despite clear signals that the Serb leadership meant not only to run an expansionist campaign to divide Bosnia with Croatia but also to destroy the Bosnian Muslim population. Instead, there were arguments about whether or not the Serb campaign in Bosnia was genocide, and if it was not genocide, whether it required intervention by other governments, especially by the Western powers. This is to say that although the experiences of World War II produced institutions to limit the excesses of war, especially as it affects civilians, this experience does not seem to have significantly changed the narrow political calculus of most states. In fact, the ideals enshrined in the Charter of the United Nations or the international law that applies to the conduct of modern warfare, such as the Geneva Conventions, are often viewed as outside or antithetical to the “reality” of international politics. It is more productive for the purposes of explanation to recognize that principled institutions, such as the UN or international law, are as much a part of world politics as are the interstate norms of sovereignty or national security. Yet while the institutions that are designed to promote collective security and provide relief from the vagaries of the international state system have gained in the postwar world, they are still beset with the contradictions of those same vagaries, namely, that states must both submit to and enforce the principles that would constrain them. The failure to intervene in Bosnia, at least on behalf of the civilian population if not also for the state of Bosnia itself, is a case in which governments that should have championed principles of international law found it more convenient to demur, despite an international awareness of the war’s excesses.
Territorial Ideology and Interstate Conflict : Comparative Considerations
Authors: Murphy Alexander B.
Published: November 2020

We live in profoundly unsettling times. The daily newspapers are filled with stories about terrorist threats, stockpiles of chemical and biological weapons, and the efforts of ever more states to acquire nuclear weapons. At the same time, longstanding interstate and intrastate conflicts continue to dominate the lives of people in such diverse settings as Israel-Palestine, southern Sudan, the India-Pakistan border, and the interior of Colombia. The issues that underlie these conflicts are as diverse as their geographic settings, but they share one commonality: they are all framed by the territorial logic of the modern state system. The foregoing statement might seem self-evident for intrastate struggles between ethnic groups or for boundary conflicts between states because these conflicts are clearly tied to the territorial reach of the modern state. Yet even the international terrorist activities associated with movements such as al-Qaeda cannot be understood without reference to prevailing international territorial norms. This is because the existing political-geographic order is a fundamental catalyst for such movements and because responses to international terrorism are often channeled in and through states. Consider, for example, the circumstances of the terrorist attacks on the United States of September 11, 2001. Chief among the articulated reasons for the attack was a sense of eroding political and cultural sovereignty in the Islamic world, as symbolized, for example, by the presence of U.S. military bases in Saudi Arabia and by the existence of a number of secular, Westernoriented regimes in the region. On the response side of the equation, a major focus of attention for the U.S. administration in the wake of September 11 was “regime change,” first in Afghanistan and then in Iraq. Against this backdrop, it is clearly important that we seek to understand the territorial logic of the modern state system and its role in different types of conflicts. A great deal of work has been done along these lines in recent decades. Scholars who have focused on the concept of the nation-state have devoted considerable attention to the gap between perception and reality that underlies the concept and have highlighted its pernicious influence in culturally diverse states.
The Geography of Peace Movements
Authors: Herb Guntram H.
Published: November 2020

Geographers have not been prominent in studying peace movements. This is not surprising, given the strong foundations of the discipline in warfare and imperialism. To date, the only general geographic survey of peace movements appears to be Brunn’s 1985 study, a catalog of peace organizations and their activities that covered mainly the United States. Other studies by geographers are few and focus on individual antiwar campaigns or disarmament strategies. However, more recently, geographers have made significant contributions to the analysis of the broader theoretical context of peace movements. These works offer spatial conceptualizations of social movement mobilization. A general appraisal of the geographic dimensions of peace movements is still missing. This chapter represents a tentative step in this direction. The examination is conducted in four steps. The first section deals with general characteristics of peace movements. It discusses problems of definition and presents the intellectual and philosophical foundations of peace activities. The second section approaches the geography of peace movements from a historical perspective. It examines the development of organized peace groups from their origins in the nineteenth century to the present. Different scales of the changing geopolitical and societal contexts will frame the discussion. Such a geohistory will allow us to identify and interpret changing intensities of activism. The third section addresses the geography of contemporary peace movements from a conceptual viewpoint. Armed with theoretical concepts from the recent literature on social movements, it examines the places and spaces of mobilization. The 1980s peace movement against nuclear armaments will serve as a case study to illustrate the insights that can be gained from a geographic approach. Finally, I will present the major implications that stem from the geohistorical and conceptual discussions in the conclusion. Peace is more than the absence of war. Though it is traditionally defined as the opposite of war, peace scholars and activists now embrace a notion of peace that includes the conditions necessary to bring about a nonviolent and just society at all levels of human activity. Contemporary peace movements not only seek to abolish the overt violence of war, but also struggle to transform the social structures responsible for death and human suffering.