bluuebunny/crossref_metadata_2025 huggingface dataset:
Resources Discovered
Authors: Gordon Robert B.
Published: November 2020

The adventurers who entered Connecticut’s Western Lands in 1730 I began ironmaking more than a hundred years after colonists first exploited the ore and fuel resources of British North America. The early colonists who set about making iron for export met with ill fortune: in 1621 Indians massacred the artisans who had just completed a furnace and forge at Falling Creek, Virginia. Scarce capital, inadequate skills, and poor transatlantic communication bankrupted the proprietors of the Saugus, Massachusetts, and New Haven, Connecticut, ironworks by 1675. When King George I got Parliament to restrain trade between England and Sweden in 1717, British manufacturers, cut off from their supplies of Scandinavian iron, began investing in American forges and furnaces. Conclusion of the seventeenth-century Indian wars had left large areas rich in timber and ore along the east coast safe for industry. New immigrants, primarily from Britain and Germany, brought their metallurgical skills to America, and colonists supported by British investors built ironworks first in Maryland and then in Pennsylvania, Virginia, and New Jersey, to produce metal for the export market. Americans in the Middle Atlantic colonies made enough iron by 1750 to provoke British regulation of their trade. The colonists made themselves the world’s third-largest iron producers by 1775 and, despite the predominance of agriculture, had firmly established industry in British North America. New Englanders lagged behind the Middle Atlantic colonists in ironmaking. Artisans from the failed Saugus works in Massachusetts slowly reestablished smelting on a small scale and by 1730 were building new works in the southeastern part of their colony. In New York, Robert Livingston had by 1685 gained control of an enormous manor adjacent to northwestern Connecticut. In 1730 he wanted to add iron to his manor’s products so that he could ship metal down the Hudson River to colonial and overseas customers. However, neither Livingston nor the Massachusetts ironmakers had anything like the high-grade ore resources discovered by the adventurers in Connecticut’s Western Lands. Fifty-two years after English colonists established themselves in Connecticut, James II sent Edmund Andros to British North America to set up a unified government over the New England colonies.
Electronic Structures
Authors: Enoki Toshiaki , Endo Morinobu , Suzuki Masatsugu
Published: November 2020

In the structure of graphite, graphene hexagon sheets are stacked in an AB stacking mode as shown in Figure 1.3. Such as mode is characterized by strong in-plane C-C bonds and weak interlayer interaction. This structural feature imparts two-dimensionality to its electronic structure. In the in-plane hexagon carbon network, the combination of sp2 σ- and π-bonds is the origin of the strong intralayer interaction, while the overlap of π-bonds between adjacent graphene sheets contributes to the weak interlayer interaction. In discussing the electronic properties around the Fermi energy, which is particularly important for the electronic structure of GICs, the π-electron orbitals play an essential role, giving graphite its unique properties. On the other hand, σ-bands, which have larger energy than π-bands, are located far from the Fermi energy. Thus they do not contribute to any serious change in the electronic properties when intercalates are introduced in the graphitic galleries. Here, we start with the electronic structure of graphite on the basis of the tight binding model. The discussion is first devoted to a graphene sheet, which is considered to be an infinite 2D hexagonal conjugated π-electron system (Wallace, 1947). Figure 5.la presents a unit cell of graphene sheet comprising two kinds of carbon atoms, α and β, where τ2 is the vector connecting the two atoms. The corresponding Brillouin zone in the reciprocal lattice is shown in Figure 5.1b.
Magnetic Properties
Authors: Enoki Toshiaki , Endo Morinobu , Suzuki Masatsugu
Published: November 2020

Two-dimensional (2D) magnetic phase transition has been one of the major topics of condensed matter physics. There are many materials in which the magnetic ions are arranged in planes so that there is strong coupling between the spins within a plane, but only a weak coupling between spins in different planes. In materials such as transition metal chlorides (FeCl2, CoCl2, and NiCl2) there is a strong ferromagnetic coupling within the planes and a coupling between planes which is weaker by a factor of 10 or so and antiferromagnetic. In more complicated ferromagnetic layer compounds such as (CH3 NH3)2 CuCl4, the interlayer coupling is down by a factor of more than a thousand. There are also many materials, such as Rb2MnF4, Rb2CoF4, and K2CoF4, in which the coupling within the plane is antiferromagnetic. This can result in a very much reduced coupling between the planes, since one spin may have four spins in the next plane which are at an equal distance, and their effects cancel out. As a result, the coupling between layers in this material is down by a factor of 106. In these layered compounds the magnetic behavior is only 2D-like at a certain distance away from the critical temperature. Close to the critical temperature, there is a long-range correlation of the spins within the layer and such a correlated region will interact between one layer and the next even if the coupling between individual spins is weak, since many spins can contribute coherently. Thus the spin order near the critical temperature is essentially three-dimensional (3D). What condition should be required for the occurrence of a real 2D spin order in layered magnetic systems? We consider a system consisting of only two magnetic layers separated by a distance. The effective interplanar exchange interaction J'eff is given by J'(ξa)2, but not by J', where ξa is the in-plane spin correlation length and J' is the interplanar exchange interaction. If ξa diverges on approaching a critical temperature, the effective interplanar exchange interaction J'eff becomes comparable with the intraplanar exchange interaction J.
Case Histories
Authors: Tammemagi Hans
Published: November 2020

Theory is fine, but practical experience is the heart of real learning. This chapter provides—as much as a book can—some real-life experience through seven case histories of how wastes are managed. The case histories describe a state-of-the-art materials recycling facility, five waste disposal facilities in three different countries (the United States, Canada, and Sweden), and a large mass-burn incinerator. Choosing which of the many thousands of landfills in existence to include was a difficult task. Three municipal solid waste landfills are described. The first, Fresh Kills landfill in New York City, was constructed in 1948 and represents older landfill technology. The second, a new landfill in East Carbon County, Utah, was built in 1992 and incorporates the latest engineered barriers and features of a modern landfill. The third is being developed in a large, abandoned open-pit mine in California. In addition, we discuss a landfill and treatment center for hazardous waste, located in Swan Hills, Alberta. A unique Swedish facility for disposing radioactive wastes rounds out the suite of landfill case histories; this facility takes a very innovative approach to waste disposal and is included to provide a different perspective on this topic. Materials recovery facilities (MRFs) are the vital heart of modern integrated municipal waste management systems. Without MRFs, recycling on any practical scale would not be possible; it is here that recyclable materials are collected and made ready for sale to secondary markets. One of the most innovative recycle centers in North America has recently been constructed in the city of Guelph in southern Ontario (Guelph, n,d.). It offers good insight into what can be achieved through recycling, and the equipment that is involved. The city of Guelph, with a population of 95,000, is situated about 60 kilometers west of Toronto. In the mid-1980s, the city began studying ways to reduce the amount of waste being placed in its landfill. These studies received a major impetus in 1991, when the province of Ontario developed a waste reduction plan that required municipalities to reduce the amount of garbage being placed in landfills by 50% by the year 2000. A number of pilot studies were conducted before the present approach was selected.
Establishing the Classroom Environment, Conducting Critiques, and Assigning Grades
Authors: Rockman Deborah A.
Published: November 2020

The kind of environment you wish to establish in your classroom is an individual decision that is in part determined by your particular personality and what makes you feel most comfortable. Some teachers prefer a very relaxed environment while others prefer a more controlled environment. Regardless of which approach most appeals to you, you must consider what will be most effective in helping the majority of students to be attentive and productive during class time. In a studio class in which most students are college freshmen right out of high school, you may find it beneficial to keep a tighter rein on things since there seems to be a tendency for the atmosphere to escalate to noisy and chaotic if boundaries are not clearly established and adhered to. In a studio class in which the majority of students are older or more experienced, it will generally not be necessary to monitor things quite so closely. This reflects the simple fact that older students tend to be more mature and often take their studies more seriously. Of course this is a generalization that does not apply to all students, regardless of age or experience. You must gauge the situation and conduct yourself accordingly. Experience indicates that if the atmosphere is too unstructured, with a lot of noise and chatter unrelated to the work being pursued, it is difficult for students to concentrate and to maximize their learning experience. It is therefore a good idea to make it very clear when it is okay to be a bit more relaxed or playful and interactive with fellow students, and when it is time to buckle down and get to some serious work and maintain an atmosphere conducive to this. When working with a model in a life drawing course, certain guidelines should be followed to insure a mutually comfortable and respectful atmosphere for the students and the model. These guidelines are discussed in chapter two under “Classroom Etiquette for Working with a Nude Model.”
Characterization of Inorganic Polymers
Authors: Mark James E. , Allcock Harry R. , West Robert
Published: November 2020

A wide variety of properties are of interest for the general characterization of polymers, as demonstrated in numerous textbooks and in more specialized books dealing specifically with characterization methods. In addition to the information of this type appearing in this chapter, there is related information in numerous other parts of this book, in particular in Chapters 4 and 8. From any of these sources of information, it becomes immediately obvious that one of the most important properties of a polymer molecule is its molecular weight. This is the characteristic that underlies all the properties that distinguish a polymer from its low-molecular-weight analogues. Thus, one of the most important goals in the preparation of a polymer is to control its molecular weight by a suitable choice of polymerization conditions. Many properties of a polymeric material are improved when the polymer chains are sufficiently long. For example, properties such as the tensile strength of a fiber, the tear strength of a film, or the hardness of a molded object may increase asymptotically with increases in molecular weight, as is shown schematically in Figure 2.1. If the molecular weight is too low, say below a lower limit Ml, then the physical property could be unacceptably low. It might also be unacceptable to let the molecular weight become too high. Above an upper limit Mu, the viscosity of the bulk (undiluted) polymer might be too high for it to be processed easily. Thus, a goal in polymer synthetics is to prepare a polymer so that its molecular weight falls within the “window” demarcated by Ml and Mu. This is frequently accomplished by a choice of reaction time, temperature, nature and amount of catalyst, the nature and amount of solvent, the addition of reactants that can terminate the growth of the polymer chains sooner than would otherwise be the case, addition of complexing agents such as crown ethers, or by the presence of an external physical field, such as ultrasound. The termination of the growth of a particular chain molecule is a statistical process. If termination happens soon after the chain starts to grow then, obviously, the completed chain will be short.
Polysilanes and Related Polymers
Authors: Mark James E. , Allcock Harry R. , West Robert
Published: November 2020

In polysilane polymers, the polymer backbone is made up entirely of silicon atoms. Therefore these materials differ from other important inorganic polymers, the siloxanes and phosphazenes, in which the polymer chain is heteroatomic. Structurally, they are more closely related to homoatomic organic polymers such as the polyolefins. However, because the units in the main chain are all silicon atoms, the polysilanes exhibit quite unusual properties. The cumulated silicon-silicon bonds in the polymer chain allow extensive electron delocalization to take place, and this delocalization of the sigma electrons in the Si-Si bonds gives the polysilanes unique optical and electronic properties. Many of the potential technical uses, as well as the remarkable properties, of polysilanes result from this unusual mobility of the sigma electrons. The polysilanes can be regarded as one-dimensional analogs to elemental silicon, on which, of course, nearly all of modern electronics is based. The photophysical behavior of polysilanes is not approached by any other materials, save for the less stable and more costly polygermanes and polystannanes. The remarkable properties of polysilanes have led to intense interest, and to numerous proposed high-tech applications. But the great promise of polysilanes as materials has yet to be realized. Their only commercial use at present is as precursors to silicon carbide ceramics, an application which takes no advantage of their optical or electronic properties. Linear polysilane polymers, properly called poly(silylene)s, can be obtained as homopolymers or copolymers. Continuation of the polysilane chain consumes two of the four valences of each silicon atom; the other two are taken up by pendent groups, which may be the same or different. Copolymers, which contain two or more kinds of silicon atoms, can be made up from units. A typical example is the copolymer of Me2Si and PhMeSi units, poly(dimethylsilylene-co-phenylmethylsilylene), which bears the popular name “polysilastyrene.” The pendent groups are typically organic units and can include alkyl, aryl, substituted aryl, hydrogen, Me3Si, ferrocenyl, and so on. An unlimited number of different polymers are possible, and several hundred compositions have been described in the literature.
Inorganic-Organic Hybrid Composites
Authors: Mark James E. , Allcock Harry R. , West Robert
Published: November 2020

A relatively new area that involves silicon-containing materials is the synthesis of “ultrastructure” materials, that is materials in which structure can be controlled at the level of around 100 Å. An example of such a synthesis is the “sol-gel” hydrolysis of alkoxysilanes (organosilicates) to give silica, SiO2. The reaction is complicated, involving polymerization and branching, but a typical overall reaction may be written . . . Si(OR)4 + 2H2O → SiO2 + 4ROH (1) . . . where the Si(OR)4 organometallic species is typically tetraethoxysilane (tetraethylorthosilicate) (TEOS, with R being C2H5). In this application, the precursor compound is hydrolyzed and then condensed to polymeric chains, the chains become more and more branched, and finally a continuous highly swollen gel is formed. It is first dried at moderately low temperatures to remove volatile species, and then is fired into a porous ceramic object. It can then be densified, if desired, and machined into a final ceramic part. Not surprisingly, the production of ceramics by this novel route has generated a great deal of interest. Its advantages, over the usual “heat-and-beat” (e.g., sintering) approach to ceramics, is (i) the higher purity of the starting materials, (ii) the relatively low temperatures required, (iii) the possibility of controlling the ultrastructure of the ceramic (to reduce the number of microscopic flaws that lead to brittleness), (iv) the ease with which ceramic coatings can be formed, and (v) the ease with which ceramic alloys can be prepared (for example, by hydrolyzing solutions of both silicates and titanates). This approach has been used to form ceramic-like phases in a wide variety of polymers. The one which has been studied the most in this regard is poly(dimethylsiloxane) (PDMS), the semi-inorganic polymer featured extensively in Chapter 4. This is due to PDMS being in the class of relatively weak elastomers most in need of reinforcement, and being capable of easily absorbing the precursor materials generally used in the sol-gel process. The same hydrolyses can be carried out within a polymeric matrix to generate particles of the ceramic material, typically with an average diameter of a few hundred angstroms. The polymer typically has end groups, such as hydroxyls, that can participate in the hydrolysis-condensation reactions.
Inbreeding and Outbreeding
Authors: Waser Nickolas M. , Williams Charles F.
Published: November 2020

Contemplate the descent of a piece of DNA (or RNA in organisms using this as their genetic material). The DNA is copied, and copies are passed to descendants. If the copies were error-free we could rightly think of them as perfect clones that pass down indefinitely through the eons. This logic led Richard Dawkins to speak of immortal coils in his book on selfish genes; here, it instead brings up issues of the common ancestry of genes and of individuals, and of the definition and consequences of inbreeding and outbreeding, the subjects of this chapter. When two individuals share one or more ancestor, they are relatives, both in common parlance and by technical definition in biology. The consequence of their mating is inbreeding, that is, the production of offspring receiving copies of a given gene through both mother and father that can be traced to the common ancestor(s). These gene copies are identical by descent (IBD; not to be confused with an acronym for inbreeding depression, see below), a shorthand for “identical by the fact of descending as copies of the same original piece of DNA”. The probability that two gene copies are IBD in a diploid individual, or its inbreeding coefficient, symbolized by f, is a simple function of the genetic relatedness of its parents and the segregation of genes during meiosis and gametogenesis. Because the probability is one-half that two gametes from the same individual carry identical gene copies, fertilization by self produces f of one-half, a brother-sister mating or parent-offspring mating produces f of one-quarter, a first-cousin mating produces f of one-sixteenth, and so on (see “Measurement of Inbreeding and Outbreeding,” below). In these examples, we assume that neither common ancestor(s) nor parents themselves are inbred; such inbreeding reflects additional common ancestry and so inflates f. From all of this, a definition of outbreeding as “mating of nonrelatives” follows automatically. As just defined, inbreeding and outbreeding rely on an absolute measure of relatedness. An alternative definition that may be of more value in real, finite populations (as opposed to ideal, infinite ones) is that inbreeding is mating with relatives more often than expected by chance, and outbreeding the opposite.
Mating Systems
Authors: Sakai Ann K. , Westneat David F.
Published: November 2020

The study of mating is one of the most active areas in evolutionary ecology. What fuels this research is curiosity about a stunning diversity of ways in which zygotes are formed. Many plants and some animals can reproduce without combining gametes. Many other plants combine gametes but do so within the same individual (selfing). Still other plants and animals require a gamete from another individual to stimulate reproduction but do not incorporate the genetic material contained in that gamete in the offspring. Finally, many organisms combine gametes produced from different individuals in sexual reproduction, but the ways in which these individuals get together to reproduce are also amazingly diverse and have major implications for how selection acts in these populations. Why are there so many different ways to reproduce? Answering this question is a major challenge for evolutionary ecologists. Our approach begins with how a variety of ecological factors affect selection on reproductive traits. Because many reproductive traits show genetic variation, diversity in selective pressures can lead to a diversity of evolutionary changes. Thus, understanding the evolutionary ecology of mating systems can help to interpret the significance of this variation and can provide new insight into related phenomena. For example, costs of female reproduction associated with development of offspring greatly impact other aspects of the life history, and males are often limited by mates (Savalli, this volume). Factors such as levels of selfing, inbreeding depression, and allocation of resources play a part in mating systems of both plants and animals (Waser and Williams, this volume), and sex allocation theory has been used in both plants and animals to explore the evolution of hermaphroditism and unisexuality (Campbell 2000; Orzack, this volume). This chapter explores some of the major forces affecting mating systems. Our treatments of plants and animals differ in emphasis, but our goal is to use the perspective of evolutionary ecology to define more fully the similarities, differences, and diversity in plant and animal mating systems, and to highlight potentially interesting yet currently unanswered questions. Diversity in patterns of zygote production arises in part from ecological factors influencing two issues: selection on the evolution of sexual reproduction itself and differentiation of the sexes.
Cooperation and Altruism
Authors: Sloan Wilson David
Published: November 2020

People have always been fascinated by cooperation and altruism in animals, in part to shed light on our own propensity or reluctance to help others. Darwin’s theory added a certain urgency to the subject because the principle of “nature red in tooth and claw” superficially seems to deny the possibility of altruism and cooperation altogether. Some evolutionary biologists have accepted and even reveled in this vision of nature, giving rise to statements such as “the economy of nature is competitive from beginning to end . . . scratch an ‘altruist’ and watch a hypocrite bleed”. Others have gone so far in the opposite direction as to proclaim the entire earth a unit that cooperatively regulates its own atmosphere (Lovelock 1979). The truth is somewhere between these two extremes; cooperation and altruism can evolve but only if special conditions are met. As might be expected from the polarized views outlined above, achieving this middle ground has been a difficult process. Science is often portrayed as a heroic march to the truth, but in this case, it is more like the Three Stooges trying to move a piano. I don’t mean to underestimate the progress that been made—the piano has been moved—but we need to appreciate the twists, turns, and reversals in addition to the final location. To see why cooperation and altruism pose a problem for evolutionary theory, consider the evolution of a nonsocial adaptation, such as cryptic coloration. Imagine a population of moths that vary in the degree to which they match their background. Every generation, the most conspicuous moths are detected and eaten by predators while the most cryptic moths survive and reproduce. If offspring resemble their parents, then the average moth will become more cryptic with every generation. Anyone who has beheld a moth that looks exactly like a leaf, right down to the veins and simulated herbivore damage, cannot fail to be impressed by the power of natural selection to evolve breathtaking adaptations at the individual level. Now consider the same process for a social adaptation, such as members of a group warning each other about approaching predators.
The Geographic Dynamics of Coevolution
Authors: Thompson John N.
Published: November 2020

Coevolution is reciprocal evolutionary change in interacting species driven by natural selection. It is a pervasive evolutionary process that has shaped many of the major events in the history of life, including the origin of the eukaryotic cell, the origin of plants, the evolution of coral reefs, and the formation of lichens, mycorrhizae, and rhizobia, all of which are crucial in the development of terrestrial communities. Just as important, evidence is increasing that Coevolution is an important ongoing ecological process, continually shaping and reshaping interactions among species, sometimes over time spans of only a few decades. This chapter is an evaluation of coevolution as an ongoing process shaped by the geographic structure of interactions among species. It is an analysis of what we have learned recently as we have taken a broader geographic view of how coevolution continually remolds the relationships among taxa. The first mathematical models of geographically structured coevolution were developed only in the past few years, and there are still fewer than a dozen empirical studies that have analyzed any aspects of coevolutionary structure and dynamics across geographic landscapes. Nevertheless, these theoretical and empirical studies have together suggested that coevolution is very likely a much more dynamic process than suggested by the previous several decades of study in evolutionary ecology. Coevolution is a hierarchical process. Local populations of species interact with one another and sometimes coevolve. These local populations are in turn connected through gene flow to populations in other communities, and this geographic structuring adds another level to the coevolutionary process. Local geographic clusters of populations may show metapopulation dynamics, and yet broader geographic groupings of populations may show considerable genetic differentiation in the traits of interacting species. Only a subset of locally or regionally coevolving traits will eventually sweep through all populations. Hence, coevolution as seen in comparisons of interacting phylogenetic lineages will show only a small fraction of the Coevolutionary dynamics found at the population, metapopulation, and broader geographic scales. Within this hierarchical structure of coevolution, many of the dynamics may occur above the level of local populations and below the level of the fixed traits of species for three reasons: Many species are collections of genetically differentiated populations, the outcomes of species interactions commonly differ among communities, and interacting species often do not have identical geographic ranges.
Predicting the Outcome of Biological Control
Authors: Myers Judith H.
Published: November 2020

The movement of humans around the earth has been associated with an amazing redistribution of a variety of organisms to new continents and exotic islands. The natural biodiversity of native communities is threatened by new invasive species, and many of the most serious insect and weed pests are exotics. Classical biological control is one approach to dealing with nonindigenous species. If introduced species that lack natural enemies are competitively superior in exotic habitats, introducing some of their predators (herbivores), diseases, or parasitoids may reduce their population densities. Thus, the introduction of more exotic species may be necessary to reduce the competitive superiority of nonindigenous pests. The intentional introduction of insects as biological control agents provides an experimental arena in which adaptations and interactions among species may be tested. We can use biological control programs to explore such evolutionary questions as: What characteristics make a natural enemy a successful biological control agent? Does coevolution of herbivores and hosts or predators (parasitoids) and prey result in few species of natural enemies having the potential to be successful biological control agents? Do introduced natural enemies make unexpected host range shifts in new environments? Do exotic species lose their defense against specialized natural enemies after living for many generations without them? If coevolution is a common force in nature, we expect biological control interactions to demonstrate a dynamic interplay between hosts and their natural enemies. In this chapter, I consider biological control introductions to be experiments that might yield evidence on how adaptation molds the interactions between species and their natural enemies. I argue that the best biological control agents will be those to which the target hosts have not evolved resistance. Classical biological control is the movement of natural enemies from a native habitat to an exotic habitat where their host has become a pest. This approach to exotic pests has been practiced since the late 1800s, when Albert Koebele explored the native habitat of the cottony cushion scale, Icrya purchasi, in Australia and introduced Vadalia cardinalis beetles (see below) to control the cottony cushion scale on citrus in California. This control has continued to be a success.
Cemetery Organization, Brood Sorting, Data Analysis, and Graph Partitioning
Authors: Bonabeau Eric , Dorigo Marco , Theraulaz Guy
Published: November 2020

In the previous two chapters, foraging and division of labor were shown to be useful metaphors to design optimization and resource allocation algrithms. In this chapter, we will see that the clustering and sorting behavior of ants has stimulated researchers to design new algorithms for data analysis and graph partitioning. Several species of ants cluster corpses to form a “cemetery,” or sort their larvae into several piles. This behavior is still not fully understood, but a simple model, in which agents move randomly in space and pick up and deposit items on the basis of local information, may account for some of the characteristic features of clustering and sorting in ants. The model can also be applied to data analysis and graph partitioning: objects with different attributes or the nodes of a graph can be considered items to be sorted. Objects placed next to each other by the sorting algorithm have similar attributes, and nodes placed next each other by the sorting algorithm are tightly connected in the graph. The sorting algorithm takes place in a two-dimensional space, thereby offering a low-dimensional representation of the objects or of the graph. Distributed clustering, and more recently sorting, by a swarm of robots have served as benchmarks for swarm-based robotics. In all cases, the robots exhibit extremely simple behavior, act on the basis of purely local information, and communicate indirectly except for collision avoidance. In several species of ants, workers have been reported to form piles of corpses— literally cemeteries—to clean up their nests. Chretien [72] has performed experiments with the ant Lasius niger to study the organization of cemeteries. Other experiments on the ant Pheidole pallidula are also reported in Deneubourg et al. [88], and many species actually organize a cemetery. Figure 4.1 shows the dynamics of cemetery organization in another ant, Messor sancta. If corpses, or, more precisely, sufficiently large parts of corposes are randomly distributed in space at the beginning of the experiment, the workers form cemetery clusters within a few hours.
The Impact of Raiding on Settlement Patterns in the Northern Valley of Oaxaca: An Approach Using Decision Trees
Authors: Reynolds Robert G.
Published: November 2020

A growing body of data indicates that armed conflict played a role in the creation of complex societies such as chiefdoms and states (Wright 1984; Spencer 1998). For example, according to Wright (1977:382), "most ethnographically reported chiefdoms seem to be involved in constant warfare," and large chiefdoms grew by absorbing their weaker neighbors. Marcus and Flannery suggest that warfare was often used to create a state out of rival chiefdoms: . . . We do not believe that a chiefdom simply turns into a state. We believe that states arise when one member of a group of chiefdoms begins to take over its neighbors, eventually turning them into subject provinces of a much larger polity. (Marcus and Flannery 1996:157) . . . As an example of this process, the authors cite Kamehameha's creation of a Hawaiian state out of five to seven rival chiefdoms between 1782 and 1810. They suggest that something similar happened in the Valley of Oaxaca, Mexico, when a chiefdom in the Etla region seized the defensible mountain top of Monte Albán and began systematically subduing rival chiefdoms in the southern and eastern parts of the valley. If this is the case, there should be a point in the sequence when considerations of defense began to influence settlement choice. In this chapter, our goal is to provide a preliminary description of our efforts in testing the suitability of this model to the Oaxacan case, and its potential use as the basis for a more general model of state formation. In order to test this hypothesis we need some way to operationalize it in terms of the archaeological record in the Valley of Oaxaca. The key phases of the model can be expressed as follows: 1. An early period in which raiding was minimal, and variables relevant to successful agriculture predominate in settlement choices. 2. A gradual rise in friction between social groups prior to state formation. This friction can be represented by archaeological evidence for raiding, the principle form of warfare in tribes and chiefdoms.
Americans and Their Weather
Authors: Meyer William B.
Published: November 2020

This revealing book synthesizes research from many fields to offer the first complete history of the roles played by weather and climate in American life from colonial times to the present. Author William B. Meyer characterizes weather events as neutral phenomena that are inherently neither hazards nor resources, but can become either depending on the activities with which they interact. Meyer documents the ways in which different kinds of weather throughout history have represented hazards and resources not only for such exposed outdoor pursuits as agriculture, warfare, transportation, construction, and recreation, but for other realms of life ranging from manufacturing to migration to human health. He points out that while the weather and climate by themselves have never determined the course of human events, their significance as been continuously altered for better and for worse by the evolution of American life.
Antebellum America
Authors: Meyer William B.
Published: November 2020

In 1810, more than four in five Americans lived in one of the original thirteen seaboard states. Half a century later, though those states had grown considerably, they held less than half of the nation's population. The reason lay in the post-1815 rush of settlers beyond the Appalachians into the continental interior, "one of the great immigrations in the history of the western world." Chaotic though this movement was in many ways, it showed at least one orderly pattern. Individually these settlers followed many paths, but the typical ones moved due west, erring to the north or south only when their path was blocked by mountains or water or political boundaries or when they were pulled aside by the easier travel routes along navigable rivers. Most of the inhabitants of every inland state in i860 came from the states to the east within its own latitudes. It was mostly New Englanders and upstate New Yorkers—themselves mostly of New England origin—who occupied the territories and states bordering on British North America. They left the central and southern parts of Ohio and Indiana and Illinois mainly to settlers from the middle states and the Chesapeake. The frontier of the Deep South was colonized from the far southern coastal states much more than from Virginia or North Carolina, states that furnished Kentucky and Tennessee and Missouri with the bulk of their inhabitants. "Ohio Fever" swept the rural Northeast after 1815, followed by "Michigan Fever" in the 1830s, but it was "Alabama Fever" and "Texas Fever" that gripped the southern states. Modern research has documented what many Americans at the time spotted for themselves, what some who could agree on little else agreed was a constant truth of human behavior growing out of a basic law of climate-society relations. "The great law that governs emigration," announced a Massachusetts congressman during an argument against the spread of slavery, "is this: that emigration follows the parallels of latitude." It was "a great law of emigration," "fixed and certain," echoed a Louisiana editor in a defense of the South and its institutions, "that people follow the parallels of latitude." People were presumed to do so in order to avoid the change of climate that traveling north or south would have entailed.
Mother Earth
Authors: Lewis William M.
Published: November 2020

The virtue of soil is one of only a few axioms of American culture. Respect for soil, which can be instilled at an early age without rousing political or religious controversy, is the mark of agrarian origins. Nevertheless, or perhaps for this very reason, the average American knows more about asteroids than about soil. Even scientists, who are responsible for knowing pretty much everything, seem generally less aware of soil than of water, air, or even rock. Thus, this chapter requires a primer on the nature of soil. The USDA, which is the center of gravity for soil science in the United States, has defined soil as “earthy materials . . . on the earth’s surface . . . capable of supporting plants out-of-doors.” To the thoughtful novice, this may seem a woefully unsatisfactory definition. In fact, one might feel downright indignant upon consulting a dictionary only to find that “earthy” means “having properties of soil.” Thus, the USDA seems to be saying that soil is something that is like soil. This could be a simple case of cheating or perhaps a devilishly clever means of suppressing debate about the definition of soil. Further reflection, however, suggests that the reference to plants is more significant than it first appears to be. Plants do not grow on bare rock, shifting sand, or the bottoms of oceans, all of which are non-soil substrates. Thus, the USDA definition may say it all, but is masterfully understated in doing so. Soil science textbooks are also a source of definitions, some of which are gratifyingly descriptive. Birkeland’s (1984) textbook, which gives a geological perspective on soil, specifies that soil is a natural entity; is composed of mineral or organic constituents, or both; differs from the material from which it was originally derived; and reflects the operation of pedogenic processes. Pedogenic processes, in turn, include the addition of organic matter from plants and other substances from the atmosphere; removal of substances by water through erosion or leaching; and a variety of internal transformations and transfers involving organic matter and minerals.
The Physical Environment of Lakes
Authors: Cohen Andrew S.
Published: November 2020

Before discussing paleolimnological archives, we need to consider those aspects of limnology that regulate how information is produced, transmitted, and filtered through the water column. Although many limnological processes leave behind sedimentary clues of their existence or intensity and are thus amenable to paleolimnological analysis, others leave little or no detectable trace. Our consideration of limnology here emphasizes the former. Throughout the next three chapters we will examine the properties of lakes, the implications of these properties for paleolimnology, and the types of physical, chemical, and biological information that can be transcribed into sedimentary archives. Physical processes in lakes are of interest because they act as intermediary hydroclimate filters between external forcing events of interest, like climate, and the paleolimnological record. For example, understanding the hydrology of a lake is important because water inputs and outputs, which are often controlled by climate, determine lake levels, which in turn are recorded by ancient shoreline elevations, or indirectly by salinity indicators. Light and heat penetration regulate the distribution of organisms and the mixing of the water column, recorded by the distribution of various fossils, sediment types, and geochemical characteristics of sediments. Also, current and wave activity affect the transport of sedimentary particles and therefore the distribution of sediment types around a lake basin. Understanding these physical processes therefore provides us with a means of linking sedimentological, geochemical, and paleobiological records of lake deposits to the external environment. Water enters and exits lakes through a variety of paths that comprise part of the earth’s hydrological cycle. The lake components of this cycle include a series of inputs and outputs of water, which in combination with the morphometry of the lake basin, collectively determine the lake’s level. Inputs include precipitation, surface runoff from rivers, and groundwater discharge into the lake. Outflows include surface outflow, evaporation, evapotranspiration losses from emergent aquatic plants, groundwater recharge, and hydration reactions with underlying sediments. If water inputs and outputs for a lake are equal over a short time span, the lake surface elevation will remain constant. This is approximately the case in most lakes that are surficially open basins.
Age Determination in Lake Deposits
Authors: Cohen Andrew S.
Published: November 2020

It is almost impossible to overemphasize the importance of good chronological control to paleolimnology. Age control allows us to determine rates of processes and fluxes of materials, and to test hypotheses of linkage between archives and hypothesized external controls of those archives. Geologists differentiate between relative age versus absolute dating methods. Relative age determinations are based on the concepts of superposition (older sediments are on the bottom, in the absence of tectonic disturbance) and lithological correlation. In contrast, absolute dating methods are done without necessary reference to other analyses or locations, to produce an age determination (i.e., 100,000 yr before present). Some methods, such as paleomagnetics, amino acid racemization, and biostratigraphy, lie in a gray area between these two, providing absolute dates or age ranges in certain circumstances and relative age constraints in others. In this book, I will refer to the general study of both relative and absolute age determination as geochronology, and use the term geochronometry to refer to absolute dating. Lithological correlation involves matching similar lithologies between outcrop or core localities, allowing a network of age relationships to be established between various sites. This can be done at any scale, from within a lake to intercontinental, although lithostratigraphical correlations based on core or outcrop observations are most commonly useful only at a local, intrabasinal level. Correlation within basins is often achieved using reflection seismic stratigraphy. Depositional or unconformity surfaces can normally be recognized on seismic lines that extend over the scale of individual sub-basins to entire lakes (Nelson et al., 1994; Lezzar et al., 1996; Van Rensbergen et al., 1998). When dated cores are obtained or outcrops studied along these seismic lines, a correlation network can be established, with probable ages attached to specific seismic horizons. Intrabasinal correlation can also be done by correlating distinctive patterns of change in features such as magnetic intensity, patterns of stable isotopic change in sediments, or biostratigraphical markers, that may be consistent across a lake basin. Sometimes, relative correlations can be made between lakes.
Paleolimnology at the Local to Regional Scale: Records of Changing Watersheds and Industrialization
Authors: Cohen Andrew S.
Published: November 2020

Paleolimnologists have developed an impressive track record documenting the history of human influence on lakes and their surroundings, and using these historical inferences to help policy makers establish lake and ecosystem management goals. Our ability to do this depends on both a comparative analysis of multiple lake records, and a firmly established chronology. The comparative approach to paleolimnology allows us to differentiate local phenomena resulting from peculiarities of study watersheds from regional phenomena. Comparison of records also allows the timing of events to be placed in a regional context, where explanations of processes that affect large areas, like lake acidification, regional patterns of air pollution, or landscape disturbance may be more broadly interpretable. Comparative paleolimnology allows the researcher to study the multiple effects of local to regional-scale phenomena and differentiate them from global phenomena. Closely coupled with our requirement for a comparative approach to paleolimnology is the need to place events in a highly resolved chronology, especially over the past 200 years, the period of greatest interest to understanding major human alternations of the environment. In many parts of the world, including the highly industrialized and relatively well-‘‘monitored’’ environments of North America and Europe, instrumental records of water quality are either spotty or unavailable. Until the 1960s, the number of lakes with regular monitoring programs for even basic limnological parameters was extremely small. And in regions with numerous water bodies, selection criteria for the investigation of lakes often has had more to do with proximity to major research facilities or peculiarities of road access than with the needs of society. Paleolimnological records integrate ecological signals at scales that are relevant to the interests of lake managers, who need to understand the timing and magnitude of human activities. Even when limnological monitoring is available, paleolimnological approaches can answer questions at temporal and spatial scales that are unattainable by the monitoring regime in place. The difficulty of understanding the history of human impacts on ecosystems is particularly acute in underdeveloped regions of the world, where access to monitoring equipment is limited. For lakes in these regions, paleolimnology may provide the only practical and relatively inexpensive means of reconstructing impact histories.