bluuebunny/crossref_metadata_2025 huggingface dataset:
Population and the Stages of Growth
Authors: Rostow W. W.
Published: November 2020

Hamish McRae's The World in 2020 begins its discussion of population with this blunt sentence: "Of all the forces that will change the world over the next generation, demography is probably the most important." 1 agree. After all, men, women, and children determine the demand for things; men and women determine the size of the workforce; and if the supply of goods and services they produce and export is not adequate, people go hungry, lack medical services, and all too often perish too young. The rhythm of human life is such that those who are born now will, by and large, live through the middle of the next century. We owe them some things. However, as this chapter argues, the future is complicated by more than simply the rate of increase of the population. There are those who do not trace the beginning of modern economics to David Hume, Adam Smith, and their colleagues in the Scottish Enlightenment of the 18th century. They prefer the "Political Arithmeticians"— the statisticians—of the late 17th century, the greatest of whom was William Petty. Petty ranged widely over the field of economics including some wise and subtle reflections on the role of minorities in international trade. In 1695, Gregory King estimated the national accounts of England and Wales as of 1688. He used, essentially, a modern balance-sheet method, demonstrating the relationships between output and expenditure for five sectors of the economy. But it was John Gaunt as early as 1662 who cast the longest shadow on the future with his estimates of death rates in London based on the bills of mortality. His work is the beginning of modem demography. What stirred these late-17th-century inquiries? It was not a precocious academic interest in measuring population and national income; it was a sense that the nations of Europe were emerging from the feudal past and its internal struggles for power into an international arena of hostility and combat. In the following century, Britain and France, for example, were at war for more than 43 years.
Conclusions
Authors: Rostow W. W.
Published: November 2020

I have tried in this book to summarize where the world economy has come from in the past three centuries and to set out the core of the agenda that lies before us as we face the century ahead. This century, for the first time since the mid-18th century, will come to be dominated by stagnant or falling populations. The conclusions at which I have arrived can usefully be divided in two parts: one relates to what can be called the political economy of the 21st century; the other relates to the links between the problem of the United States playing steadily the role of critical margin on the world scene and moving at home toward a solution to the multiple facets of the urban problem. As for the political economy of the 21st century, the following points relate both to U.S. domestic policy and U.S. policy within the OECD, APEC, OAS, and other relevant international organizations. There is a good chance that the economic rise of China and Asia as well as Latin America, plus the convergence of economic stagnation and population increase in Africa, will raise for a time the relative prices of food and industrial materials, as well as lead to an increase in expen ditures in support of the environment. This should occur in the early part of the next century, If corrective action is taken in the private markets and the political process, these strains on the supply side should diminish with the passage of time, the advance of science and innovation, and the progressively reduced rate of population increase. The government, the universities, the private sector, and the professions might soon place on their common agenda the delicate balance of maintaining full employment with stagnant or falling populations. The existing literature, which largely stems from the 1930s, is quite illuminating but inadequate. And the experience with stagnant or falling population in the the world economy during post-Industrial Revolution times is extremely limited. This is a subject best approached in the United States on a bipartisan basis, abroad as an international problem. It is much too serious to be dealt with, as it is at present, as a domestic political football.
Hydrology and Hydrochemistry
Authors: Williams Mark W. , Caine Nel
Published: November 2020

Seasonally snow-covered areas of Earth’s mountain ranges are important components of the global hydrologic cycle. Although their area is limited, the snowpacks of these areas are a major source of the water supply for runoff and ground water recharge over wide areas of the mid-latitudes. They are also sensitive indicators of climatic change. The release of ions from the snowpack is an important component in the biogeochemistry of alpine areas and may also function as a sensitive indicator of changes in atmospheric chemistry. The demand for water in the semiarid areas of the western United States is reflected in extensive systems of reservoirs, canals, and flow diversions that have been constructed over the past century. Most of the water resources tapped by these systems derives from the mountain environments of the Rocky Mountains, where contributions of the alpine have long been recognized (Martinelli 1975). In Colorado, 9000 km2 of alpine terrain, less than 4% of the state’s area, provide more than 20% of the state’s streamflow and is especially important in maintaining late-summer flows (Martinelli 1975). Lakes in the Rocky Mountains are relatively uncontaminated compared with many other high-elevation lakes in the world, with the median value of NO-3 concentrations less than 1 μeq L-1 (Psenner 1989). However, in comparison with downstream ecosystems, these high-elevation ecosystems are relatively sensitive to changes in the flux of energy, chemicals, and water because of extensive areas of exposed and unreactive bedrock, rapid hydrologic flushing rates during snowmelt, limited extent of vegetation and soils, and short growing seasons (Williams 1993). Hence, even small changes in atmospheric deposition have the potential to result in large changes in ecosystem dynamics and water quality (Williams et al. 1996a). Furthermore, these ecosystem changes may occur in alpine areas before they occur in downstream ecosystems (Williams et al. 1996b). Apart from its use in municipal supply, agriculture, recreation, and power generation, this water also mediates transfers of geomorphic and biological materials. For this reason, the drainage basin, or catchment, has long been recognized as a basic geomorphic unit in environmental research (e.g., Chorley 1967; Bormann and Likens 1969).
The Vegetation: Hierarchical Species-Environment Relationships
Authors: Walker Marilyn D. , Walker Donald A.
Published: November 2020

The vegetation of Niwot Ridge has a rich history of study, beginning with phytosociological studies directly on the Ridge and in the surrounding mountains and incorporating more experimental and dynamic approaches in later years. This chapter provides an overview of the spatial patterns of Niwot Ridge plants and plant communities relative to the primary controlling environmental gradients at scales from the individual to the landscape. The spatial patterns of vegetation at all scales are dominated by physical forces, particularly the interaction of wind, snow, and topography. The controls of biotic factors on the distribution and abundance of plant species on Niwot Ridge have received considerably less attention than have physical factors, but recent studies have revealed the importance of competition and certain mutualisms in structuring community composition. Community research on Niwot Ridge has been organized around a hierarchy of spatial scales, from the plot to the region. Plot-based studies have focused on physiological and ecological dynamics of specific species and communities, and more spatially extensive studies have provided a hierarchical framework for the plot studies. In this chapter, we first present an overview of the broader patterns in the vegetation, followed by descriptions of the communities, and then the specifics of physical and biotic controls on species and plant growth that drive the community patterns. The landscape-scale patterns in the Niwot vegetation are driven by a complex elevation gradient, which is a combination of temperature and snow regime, with wind modifying and interacting with temperature and snow at all points along the gradient (chapter 2). Certainly the most critical boundary in the system is the upper tree limit, which defines the alpine system and which lies roughly between 3400 and 3600 m elevation on Niwot Ridge. Billings (1988) provided a climatic-floristic-physiographic review of major North American alpine systems that helps to place Niwot Ridge into a larger perspective. Climatically, Niwot is intermediate between the dry Sierras, which have greater precipitation but almost none of it falling during the summer, and the wetter northern Appalachians (Mt. Washington), which have fairly even annual precipitation and no drought.
Uniformitarianism and Unity
Authors: Oreskes Naomi
Published: November 2020

William Bowie settled on a theoretical position that accounted for isostasy and the jigsaw-puzzle fit of the continents but ignored the facts of historical geology. And yet, as we have seen, he interacted and corresponded with historical geologists, particularly with Charles Schuchert (1858–1942). Of all the American geologists who ultimately rejected the theory of drift, Schuchert was perhaps the one who engaged the problem the most seriously. As America’s foremost historical geologist, Schuchert was well placed to argue the case for or against drift, and he grappled with the question of continental connections for at least fifteen years. In the end, however, Schuchert, like Bowie, rejected continental drift. Just as Bowie argued against drift because of beliefs grounded in the exigencies of geodetic practice, Schuchert ultimately argued against drift because of beliefs grounded in the exigencies of geological practice. For Bowie, the practice was Pratt isostasy, for Schuchert, it was Uniformitarianism. Charles Schuchert rejected continental drift because he interpreted it to be incompatible with Uniformitarianism. However, he did not reject it because he could not see drift taking place, as might be supposed. Uniformitarianism has meant many things to many people, and to Charles Schuchert in the late 1920s, it meant—rightly or wrongly—an essentially steady-state earth, whose details were forever changing but whose large-scale patterns and relationships remained the same. And this seemed to him to deny the possibility of major changes in the configuration of the continents. Moreover—and perhaps more importantly—for Schuchert, as for most historical geologists, Uniformitarianism was a form of scientific practice, a means of doing historical geology. It was, in fact, the primary means of doing historical geology. For Schuchert, abandoning Uniformitarianism was nearly tantamount to abandoning historical geology altogether. Not surprisingly, he declined to do this. Like William Bowie, Charles Schuchert settled on a theoretical position that preserved his scientific practice. But whereas Bowie’s theoretical ideas had little staying power, the alternative that Schuchert embraced influenced a generation of geologists to believe that drift was not so much impossible as unnecessary.
Igneous Rocks, Meteorites, and Fluid-Rock Interactions
Authors: Criss Robert E.
Published: November 2020

Oxygen is the most important element in common, rock-forming minerals. Earth’s crust and mantle contain about 44 wt. % oxygen, and even with its dense iron core, the bulk Earth is estimated to be approximately 30% oxygen. Considering the low mass and large size of the oxygen atom, the oxygen content is even higher if expressed in terms of vol. % or mol. %. For the above reason, a central problem of stable isotope geochemistry is to explain the distribution of oxygen isotope ratios in rocks. As shown in this chapter, much of the diversity in the abundance ratios is related to interactions of rocks with Earth’s extensive hydrosphere, which is nearly 89 wt. % oxygen. Even though hydrogen is only a minor element in rocks, some discussion of hydrogen isotopes is included here because they provide powerful complementary relationships to evaluate fluid-rock interactions. It has been suspected for centuries, and has now been proven by oxygen isotope data (see later), that Earth and the Moon have very similar origins. In particular, the δ18O values of large rock reservoirs on the Moon and Earth are practically identical. Diverse lunar lithologies have remarkably uniform values ranging only from +5.4 to +6.8 relative to SMOW, with the subset of lunar igneous rocks showing even less variation at +5.7 ± 0.2 (Epstein and Taylor, 1971; Taylor and Epstein, 1973). The same limited range of values is found for the largest lithologic reservoirs on Earth. For example, mid-ocean ridge (MOR) basalts are the most abundant igneous rock type on Earth, and cover practically the entire ocean floor. The δ18O values of these basalts are practically uniform at +5.7 ± 0.5 (Kyser, 1986). Similarly, other mafic lavas, as well as peridotites, pyroxenites, and practically all other mantle materials with the exception of the ophiolites and eclogites, have δ18O values in the restricted range of +5.0 to +8.0. Moreover, no apparent secular trend over geologic time has been found in the bulk δ18O values of these reservoirs. For these reasons, it is likely that the bulk δ18O values of Earth and the Moon are identical and very close to +5.7 ± 0.2.
Introduction
Authors: Havstad Kris M. , Schlesinger William H.
Published: November 2020

Arid lands throughout the world are often degraded or increasingly at risk of degradation. These lands, including those at the border of arid regions, commonly exhibit accelerated soil erosion, losses of productivity, and impaired economic potential to support human populations. Human history is replete with the collapse of great civilizations of the hot and dry subtropics that suffered severe soil resource depletions in their midst or at their margins. Given that over 1 billion people currently inhabit the arid lands of the world, it is critical that we have the knowledge and resulting technologies to mitigate our impacts and improve environmental conditions of these lands and their resources. This book describes our understanding of basic processes of arid ecosystems resulting from nearly a century of research in one desert locale, the Jornada Basin of southern New Mexico. Much of our understanding comes from both extensive and intensive studies in a landscape that has drastically changed over that time. The loss of ecological, economic, and social capital is called “desertification” (Dregne et al. 1991). The 1992 United Nations Desertification Convention defined desertification as “land degradation in arid, semiarid and dry subhumid areas resulting from various factors, including climatic variations and human activities.” In the future, we can expect that the shifting border between arid and semiarid lands will be one of the most sensitive indicators of global change. Desertification involves human and environmental drivers of change but is a regional symptom that emerges from degradation at finer spatial scales (Reynolds and Stafford Smith 2002). Desertification does not describe cyclic phenomena, as when decadal variations of precipitation lead to periods of drought and to losses of vegetation cover that are fully restored when rains return (Tucker et al. 1994). An updated and revised desertification paradigm has been developed by Reynolds et al. (2003; table 1-1). An important feature of this conceptual model is that both biophysical and socioeconomic factors are jointly involved in desertification. This paradigm clearly recognizes critical points, or thresholds, in system dynamics, yet these points may be manageable for increasing system resilience.
The United Nations Convention on the Law of the Sea
Authors: Levy John-Pierre
Published: November 2020

When the United Nations Convention on the Law of the Sea (the Convention) was adopted in 1982 after nine years of negotiations, it was hailed as "the ultimate constitution for the oceans". For the first time, an international legal instrument acknowledges that "the problems of ocean space are closely interrelated and need to be considered as a whole". Accordingly, in 320 articles and 9 annexes, the treaty provides the international legal framework for exercising the rights and duties of States relating to their uses of ocean space and its resources. After substantially amending the part dealing with the deep seabed area and its resources by the Agreement of 28 July 1994, the Convention entered into force on 16 November 1994 for those States which deposited instruments of ratification. It is now strongly supported by a significant majority of the States of the world, including major maritime powers, developing states, and others. The Convention codifies and develops customary international law as well as creating new rules and institutions. In some respects, the Convention provides specific rules and, in other respects, more general rules, whose precise meaning will evolve through practice. The Convention provides at minimum a framework for all uses of the sea. It envisages other international agreements, bilateral and multilateral, to elaborate its implementation. In spite of the breadth of the subject matter, the practice of States generally conforms to the law of the sea embodied in the Convention. The international community rightly feels proud of its achievement. But international law (and the law of the sea in particular) is a reflection of the needs of States during a certain period in history and their expectations of the future. This Convention does not necessarily contain the answers to all the challenges awaiting humankind in the 21st century, but it provides a sound framework for addressing them. Before examining in depth the issues relating to the delimitation of the outer limit of the continental shelf, a brief review of the major features of the Convention is appropriate. In the aftermath of World War II and soon after the creation of the United Nations in 1945, the new world organization requested its International Law Commission to consider the codification of existing customary international law relating to the oceans.
RNA Structure Analysis: A Multifaceted Approach
Authors: Shapiro Bruce A. , Kasprzak Wojciech
Published: November 2020

Genomic information (nucleic acid and amino acid sequences) completely determines the characteristics of the nucleic acid and protein molecules that express a living organism’s function. One of the greatest challenges in which computation is playing a role is the prediction of higher order structure from the one-dimensional sequence of genes. Rules for determining macromolecule folding have been continually evolving. Specifically in the case of RNA (ribonucleic acid) there are rules and computer algorithms/systems (see below) that partially predict and can help analyze the secondary and tertiary interactions of distant parts of the polymer chain. These successes are very important for determining the structural and functional characteristics of RNA in disease processes and hi the cell life cycle. It has been shown that molecules with the same function have the potential to fold into similar structures though they might differ in their primary sequences. This fact also illustrates the importance of secondary and tertiary structure in relation to function. Examples of such constancy in secondary structure exist in transfer RNAs (tRNAs), 5s RNAs, 16s RNAs, viroid RNAs, and portions of retroviruses such as HIV. The secondary and tertiary structure of tRNA Phe (Kim et al., 1974), of a hammerhead ribozyme (Pley et al., 1994), and of Tetrahymena (Cate et al., 1996a, 1996b) have been shown by their crystal structure. Currently little is known of tertiary interactions, but studies on tRNA indicate these are weaker than secondary structure interactions (Riesner and Romer, 1973; Crothers and Cole, 1978; Jaeger et al., 1989b). It is very difficult to crystallize and/or get nuclear magnetic resonance spectrum data for large RNA molecules. Therefore, a logical place to start in determining the 3D structure of RNA is computer prediction of the secondary structure. The sequence (primary structure) of an RNA molecule is relatively easy to produce. Because experimental methods for determining RNA secondary and tertiary structure (when the primary sequence folds back on itself and forms base pairs) have not kept pace with the rapid discovery of RNA molecules and their function, use of and methods for computer prediction of secondary and tertiary structures have increasingly been developed.
Religion and the Modern American University, 1910-1928
Authors: Kemeny P. C.
Published: November 2020

Princeton, read a trustees’ report in January 1927, “has always recognized a dual obligation to its undergraduates.” One side of this commitment involved providing “a curriculum which will meet the needs of a modern university” and the other involved creating within students “those spiritual values which make for the building of character.” Wilson had reshaped Princeton into a modern university and had left as his legacy an unyielding commitment to serving national interests. Undergraduate education, graduate training, and a variety of impressive specialized research programs enabled the university to help meet the nation’s need for liberal, civic-minded leaders and the demand for science and practical technology. Wilson and his successors in early-twentieth-century Princeton continued to insist, like their nineteenth-century predecessors, that Protestantism was indispensable to the public good and that civic institutions, such as Princeton, served public interests when they sought to inculcate students with a nonsectarian Protestant faith. In this way, the university, they believed, helped mainline Protestantism play a unifying and integrative role in a nation of increasing cultural and religious diversity. By doing so, they reasoned, Princeton, like other private colleges and universities, would maintain its historic religious mission to advance the Christian character of American society. During the presidency of Wilson’s successor, John G. Hibben, controversies challenged the new configuration of Princeton’s Protestant and civic missions. These controversies, however, helped to strengthen the new ways in which the university attempted to fulfill its religious mission in the twentieth century. In liberal Protestantism, the university found a religion that was compatible with modern science and the public mission of the university. Those traditional evangelical convictions and practices that had survived Wilson’s presidency were disestablished during Hibben’s tenure. Fundamentalists’ criticisms of the university hastened this process in two ways. Sometimes fundamentalist attacks upon the university convinced the administration to adopt policies that guaranteed the displacement of traditional evangelical convictions and practices. This was the case, for example, when fundamentalists’ condemnations of the theological liberalism of the university’s Bible professor accelerated the administration’s approval of a policy of academic freedom.
Parts of a Soil (Soil Constituents) Air, Water, Minerals, and Organic Matter
Authors: Keefer Robert F.
Published: November 2020

Soils physically consist of soil solids and pore space. Soil solids are composed of (a) mineral matter such as sand (coarse particles), silt (fine particles), and clay (very fine particles), and (b) soil organic matter, like decaying plant, animal, and microbial remains, along with microbial synthates. The pore space is occupied by soil air and soil water, each of which has a different makeup than atmospheric air and rainwater. Soil air often has more carbon dioxide and gases of nitrogen and sulfur compounds. Soil water has much more dissolved substances in it than rainwater. Soil solids occupy about 50% of a soil. They are made up of about 45% mineral matter and about 5% organic matter, but these proportions vary greatly. Soil mineral matter consists of very coarse rocks (primary minerals) and the three main soil parts: . . . 1. Coarse—Sand (a primary mineral, silicon dioxide) 2. Fine—Silts (both primary or secondary minerals) 3. Very Fine—Clays (secondary minerals) . . . Soil organic matter consists of plant and animal remains (in various stages of decomposition), microorganisms, and compounds synthesized by microorganisms. Soil pore space occupies about 50% of a soil and consists of the open space occupied by either air or water. The proportions of air and water that are present can greatly influence plant growth. Soil air is necessary for plants to grow, but if this component dominates, drought occurs and plant growth suffers. Soil water is also necessary for plant growth, but if this component dominates, flooding occurs and plant growth also suffers as most plants require a supply of oxygen. Soil consists of natural elements, for example, Si, Al, Fe, Ca, Mg, Na, K, Ti, P, and others. Often the elements are present in oxides, sulfides, silicates, and other combinations. These elements or their combined form are present as rocks (primary minerals), clays (secondary minerals), and available nutrients for plants. Soil contains many life forms.
Introduction
Authors: Chu C. Y. Cyrus
Published: November 2020

The classical model of Malthus ([1783] 1970) can be described as a supply-side, dynamic, macro theory of population. It is a supply-side theory because Malthus did not emphasize the role of individual demand decisions on population-related variables. Individuals in ancient times certainly had their preferences for children and marriage; but Malthus assumed that such preferences would by and large be checked by natural constraints and that only when families had sufficient incomes would their preferences for children and marriage be effectively revealed (Schultz, 1981). In ancient times, when the hygienic environment and medical technology were primitive, and when production technology and administrative capacity changed relatively slowly, the natural checks on human growth and fertility almost always dominated the dynamics of population; the demand-side scenario, which originates from individual preferences, never played a significant role. The Malthusian theory is mainly a dynamic one because it describes why a population would have an equilibrium size that corresponds to the subsistence level of income and why a population would converge to such an equilibrium. Malthus argued that when a population size is larger than the equilibrium size, the per capita income will fall because of diminishing returns. This fall will be followed by an increase in mortality and a reduction in population growth rate, which in turn will drive the population size down to the equilibrium. When a population size is smaller than the equilibrium, the adjustment mechanism works in the opposite way, and the size increases toward the equilibrium. The conventional Malthusian model also largely ignores differences in decisions made by individual families; hence a set of macro variables becomes the only focus, thereby making a simple dynamic analysis possible. As Samuelson (1976) pointed out, although most classical economists, such as Adam Smith, David Ricardo, and John Stuart Mill, considered population analysis part of economics, by the early twentieth century most economists had decided that demographic movements were largely exogenous to the economic system and should be left to sociologists and other noncconomists for discussion. A more active alternative for economists is to modify the conventional Malthusian theory to allow it to be compatible with contemporary population practices and issues.
Deletion
Authors: West-Eberhard Mary Jane
Published: November 2020

Deletion, or trait loss, may seem a step backward rather than a step toward something new. Goldschmidt (1940) emphasized the regressive aspect of deletion by calling it “rudimentation.” But trait deletions create novelties by subtraction, in at least four different ways. First, a complex trait lacking an element may immediately have an altered function. A worker honeybee, for example, is a mature brood-tending female minus the ability to lay eggs, and a queen is a solitary female minus the ability to care for the brood. These reciprocal, complementary deletions, reinforced by kinship, make the two kinds of female into mutually dependent collaborators. Second, the loss of a trait may have correlated developmental effects that force the remaining phenotypic elements into new configurations, as with the virtually deleted forelegs of the two-legged goat (see chapter 3). Third, a deletion, if it is repeatedly produced, makes the resultant phenotype subject to divergent evolution under selection, simply because it is different. Finally, deletion of a phenotypic subunit can release other, genetically and developmentally correlated traits from the evolutionary constraints represented by these correlations, freeing the remaining traits to evolve more rapidly and independently. Deletions can evolve gradually, by change in regulation to reduce the frequency of expression of a trait, as in loss of an alternative phenotype, or by change in form such that elements of the phenotype are gradually lost, as in flight reduction in insects beginning with loss of flight behavior, then wing musculature, then wings (Shaw, 1970; see figure 5.26). Classical gradualism refers to the latter type of change—gradual loss of elements of form— as suggested by the occurrence of mosaic intermediates (e.g., a flightless population that possesses wings). A deletion occurs every time an alternative phenotype evolves to fixation, which means that its former alternative is no longer expressed. Since this is a step in the evolution of many constitutive qualitative trait (see part III), regulatory deletions of alternative phenotypes must be common events. As with other kinds of phenotypic change, deletions occur at different levels of organization, from pieces of genes to elements of behavior and whole life stages of individual development.
Gradualism
Authors: West-Eberhard Mary Jane
Published: November 2020

Ever since Darwin, there has been a tension between selectionists and developmentalists over the question of gradualism versus saltation and selection versus variation. Does form evolve by a series of small modifications, each one mediated by selection? Or does complex change in form originate suddenly due to a developmental change? Why should there have been such an enduring controversy over these questions? There would seem to be no intrinsic conflict between a belief that development produces variations, some of them discrete and phenotypically complex, and a belief that selection chooses among them. The significance of gradualism for Darwin’s argument regarding natural selection has often been lost from view. The gradualism versus saltation question is not just a debate over whether or not large variants can occur and be selected, although this might seem to be the issue from the dichotomy “gradual versus saltatory.” One may get the impression from Bateson’s (1894) compendium of complex developmental anomalies (figure 24.1), and Goldschmidt’s (1940 [1982]) discussion of hopeful monsters, that Darwin overlooked the evolutionary importance of large developmental variants. In fact, Darwin (1868b [1875b]) extensively reviewed developmental anomalies, including meristic freaks such as those emphasized by Bateson, and considered large qualitative variants likely important in artificial selection producing certain breeds of dogs. In essence, the gradualism-saltation debate is a debate over the causes of adaptive design. Is adaptive design primarily the result of selection, which molds the phenotype step by small step, as Darwin argued? Or is it mainly due to the nature of developmentally mediated variation, with selection playing only a minor, if any, role in the creation of form, as argued by Bateson? Bateson (1894) was among the first to articulate the variationist position: . . . the crude belief that living beings are plastic conglomerates of miscellaneous attributes, and that order of form . . . has been impressed upon this medley by Selection alone; and that by Variation any of these attributes may be subtracted or any other attribute added in indefinite proportion, is a fancy which the Study of Variation does not support. . . .
Oxidoreductases
Authors: Frey Perry A. , Hegeman Adrian D.
Published: November 2020

Oxidoreductases constitute a very large class of enzymes. They are dehydrogenases and reductases that catalyze the removal or addition of the elements of molecular hydrogen to or from substrates. Enzymatic dehydrogenation is sometimes linked to auxiliary functions such as decarboxylation, deamination, or dehydration of the substrate, as in the actions of isocitrate dehydrogenase (decarboxylation), glutamate dehydrogenase (deamination), and ribonucleotide reductase (deoxygenation). The best known oxidoreductases are the NAD-dependent dehydrogenases, and a thorough discussion of the actions of these enzymes could easily fill a volume the size of this book. For this reason, this discussion must focus on the salient aspects of reaction mechanisms that represent the major classes of oxidoreductases. Authoritative reviews on the kinetics and structures of the main dehydrogenases are available (Banaszak et al., 1975; Brändén et al., 1975; Dalziel, 1975; Harris and Waters, 1976; Holbrook et al., 1975; Rossman et al., 1975; Smith et al., 1975; Williams, 1976). In this chapter, we emphasize the diverse oxidoreduction mechanisms and place less emphasis on auxiliary functions such as decarboxylation, the mechanisms of which are similar to the actions of enzymes discussed in earlier chapters of this book. Discussions of several dehydrogenases not included in this chapter can be found in other chapters. These include methanol, glucose, and methylamine dehydrogenases in chapter 3, dimethylsulfoxide reductase in chapter 4, and dihydrofolate reductase and β-hydroxymethylglutaryl CoA reductase in chapter 5. Pyruvate and α-ketoglutarate dehydrogenases are discussed in chapter 18. Enzymatic addition or removal of the elements of hydrogen to or from an organic molecule generally requires the action of a coenzyme. In principle, the process may proceed by any of several mechanisms, including the formal transfer of a hydride and a proton; or the transfer of two electrons and two protons; or the transfer of a hydrogen atom, an electron, and a proton; or any of several other sequences. Proteins alone do not efficiently catalyze these processes; coenzymes and cofactors generally provide the essential chemistry for catalysis by oxidoreductases. Many enzymes catalyze the dehydrogenation of an alcoholic group to a ketone or aldehyde coupled with the reduction of NAD+ to NADH.
An Overview of Travel by Design
Authors: Boarnet Marlon , Crane Randall C.
Published: November 2020

Start with the trips people make from home to work, and then back home again. Each commute reflects choices of where to live, where to work, when to work, when to go home, how to get from home to work, and what side trips to make along the way. Each decision depends on the opportunities available, with those in turn explained by the characteristics, resources, and values of workers, their families, their employers, other travelers, and of course the built environment of sidewalks, streets, bus routes, and rail lines connecting home to work. Nonwork trips, the great majority of trips in modern times, entail even more finely detailed mosaics of people, places, and the variety of things one obtains, or hopes to obtain, by going somewhere. Travel is the outcome of a grand confluence of human and other factors, many systematic and many others not. It will never be fully understood. But because travel poses numerous challenges, and opportunities, it would be good to understand more. Planning strategies to reduce traffic congestion and improve air quality continue to get prominent attention. Several increasingly influential efforts emphasize the potentially mitigating role of the built environment. For example, a good deal has been made in recent years of the fact that people drive less and walk more in downtown San Francisco than in suburbs anywhere. Part of this observed behavior is no doubt attributable to the kinds of people living there, people who prefer and indeed seek out the many benefits—travel and otherwise—of a diverse, high-density, mixed-use environment. But many observers have also asked, quite reasonably, if it would not make sense to design suburbs and other neighborhoods to be more like downtown San Francisco, or more like whatever it is about those places that leads people to drive less. Perhaps then people in suburbs and elsewhere would drive less and walk more. And perhaps that would lead to improvements in traffic congestion, air quality, and other transportation problems associated with the automobile.
The Trouble with Traffic
Authors: Boarnet Marlon , Crane Randall C.
Published: November 2020

What about cars is bad? In turn, what should transportation planners do? In the early years of the automobile era, the transportation planner’s job was to develop street and highway networks. Sometimes the thinking was as simple as drawing lines on a map to connect concentrations of trip origins and trip destinations, and then building highways along the path that most closely corresponded to those lines. Air quality problems were not conclusively linked to automobile travel until the 1950s. Issues such as the displacement of persons from residential neighborhoods and the impact on habitat were secondary concerns at best until the 1960s. The primary, almost exclusive, focus during the first decades of the automobile era was to build a street and highway network that could accommodate a new mode of transportation. This began to change by the late 1960s. Planned highway networks neared completion in many cities. At the same time, the broader social costs of transportation became more apparent. Automobile emissions are a major contributor to urban air pollution. Traffic congestion has been a perpetual problem for several decades in most cities. Neighborhoods severed by highway projects often quickly deteriorated. Scholars and policy analysts now ask whether transportation resources are fairly distributed across different segments of society and how transportation access is linked to labor market success. As all of these issues have moved to the fore, transportation planning has increasingly focused on how to manage the social implications of transportation projects. Modern transportation planning now necessarily focuses as much on managing the social costs of travel as on facilitating travel. Because 87 percent of all trips in the United States in 1990 were by private vehicle (mostly cars and light trucks), the social costs of travel are, first and foremost, the social costs of the automobile. Public concerns regarding air quality, congestion, neighborhood stability, and equity gave rise to new regulatory agencies, technological innovations, and legal frameworks for transportation planning. Yet the demand for cleaner, less congested, more fair transportation systems persists. This is the context for the new urban designs. They seek, in large part, to address the social costs of automobile travel.
Why Children Talk to Themselves
Authors: Berk Laura E.
Published: November 2020

If you could become the shadow of a 2- to 8-year-old, furtively tagging along as the child goes about his or her daily activities, you would notice a curious form of language behavior—remarks in which the child seems to talk to himself or herself or to no one in particular. This speech-to-self occurs frequently. It can surface in virtually any of the child’s pursuits—during fantasy play, drawing and painting, building with blocks, tackling academic tasks, idly passing the time of day, and quieting down before naptime or nightly sleep. Researchers call this spontaneous, self-directed talk private speech. Unlike adults, who self-consciously talk to themselves only in solitary moments, young children freely use private speech in public. So at ease are preschool and primary-school children in speaking to themselves in front of others that on observing this behavior, many adults question its normalcy! “Confused,” “touched,” and “strange” are among the descriptors I have heard them apply to self-talking children, generalizing from “crazy people,” who not only speak aloud to fantasized audiences but also act improperly in a great many ways because they are indifferent to their social surroundings. To be sure, talking to oneself in the midst of a roomful of people is not acceptable in the adult social world. Yet all of us engage in private speech from time to time. And it is ubiquitous in early childhood. When children between the ages of 3 and 10 are observed in classrooms, private speech makes up as much as 20 percent to 60 percent of their language. Why do young children engage in it so frequently? To grasp the significance of private speech in the life of the child, let’s begin by looking at it in ourselves. When are you most likely to talk out loud to yourself? In response to this question, most adults say they engage in audible self-talk when they face cognitive, emotional, or social challenges. Here are some self-reports: • “At the end of a busy day, when I’m tired and distracted, I sometimes find myself looking for an important document, for my keys, or even for where I parked my car.
Learning in Classrooms
Authors: Berk Laura E.
Published: November 2020

A visitor entering Tamara’s combined kindergarten/first-grade classroom is likely to be struck by its atmosphere of calm purposefulness, given that so much is happening at once. On a typical day, twenty-two 5- to 7-year-olds are busy working on diverse activities throughout the room. At ten o’clock one Tuesday, several children were in the writing center—one preparing a thank you note and four others collaborating on making a list of the names of everyone in the class. In the reading center, five children were browsing the shelves or reading books, in pairs and individually. At a table next to shelves filled with math materials, four children worked in pairs on a problem requiring them to choose items from a restaurant menu without exceeding their budget. Yet another pair was immersed in an interactive computer activity about plants as sources of foods. Tamara was seated at a table, reading and discussing a story with a cluster of six children. The children in Tamara’s class come from a variety of ethnic and socioeconomic backgrounds. About three-fourths live in the middle-income neighborhood surrounding the school, located in a midsize Midwestern city. The rest are bussed from a housing project for low-income families several miles away. Two children have reading disabilities, and one has a speech and language delay. Several times a week, a learning disabilities teacher and a speech therapist come to the classroom to assist these children. Tamara’s students present great variations in experiences, knowledge, and academic skills. She uses this diversity to enrich their learning. The classroom is organized into seven clearly defined activity centers. The largest is the reading center, which doubles as a class meeting area. Others are the writing center, the math center, the life science center, the physical science center, the art center, and the imaginative play/extended project center. Computers can be found in the life science and writing centers. All centers are brimming with materials—on shelves and in boxes and baskets, clearly labeled and within children’s easy reach. And each center contains a table to serve as a comfortable workspace for collaborative and individual pursuits.
The Child in Contemporary Culture
Authors: Berk Laura E.
Published: November 2020

In this chapter, I take up dilemmas that today’s parents face in rearing young children. Throughout this book, we have touched on myriad forces that make contemporary parenting highly challenging. These include one-sided, contradictory messages in the parenting-advice literature; career pressures that impinge on parent involvement in children’s lives; abysmally weak American child-care services to assist employed parents in their child-rearing roles; cultural violence and excessive materialism permeating children’s worlds; schools with less than optimal conditions for children’s learning; and impediments to granting children with deficits and disabilities social experiences that maximize their development. Contemporary parents do not just find child rearing more difficult; they feel more uncertainty than their predecessors about whether and how to intervene in their children’s activities and behavior. In the pages that follow, I draw on major themes of this book—the power of adult warmth, appropriate expectations, narrative conversation, make-believe play, and teaching in the “zone”—to show how Vygotsky’s sociocultural approach can serve as a guide for resolving a great many child-rearing concerns. This chapter answers twenty questions drawn from a survey of over four hundred parents of 2- to 8-year-olds living in a Midwestern city with a population of one hundred thousand. In that survey, I asked parents to list any questions about young children’s development and learning that interested or worried them. The questions I answer here address issues that appeared most often in parents’ responses. Each represents a concern that surfaced in three or more parental replies. I intend these answers to parents’ questions to reflect a way of thinking about child rearing, not a set of recipes for dealing with specific events. When parents are familiar with principles that are grounded in contemporary theory and research on children’s development, they can better deal with the quandaries generated by the changing home, school, and community contexts in which today’s children grow up. Although adverse cultural trends have complicated and threatened good child rearing, parents—as agents of change, buffers against stressful life circumstances, and gatekeepers of learning opportunities—can do much to protect, restore, and reshape children’s experiences.
Solute Movement in the Rhizosphere
Authors: Tinker Peter B. , Nye Peter
Published: November 2020

This is a completely revised edition of the previously titled Solute Movement in the Soil-Root System. It describes in detail how plant nutrients and other solutes move in the soil in response to plant uptake, and it provides a basis for understanding processes in the root zone so that they can be modeled realistically in order to predict the effects of variations in natural conditions or our own practices.