Showing papers by "Cornell University published in 1995"

The Cognitive Neurosciences

Abstract: Each edition of this classic reference has proved to be a benchmark in the developing field of cognitive neuroscience. The fourth edition of The Cognitive Neurosciences continues to chart new directions in the study of the biologic underpinnings of complex cognition -- the relationship between the structural and physiological mechanisms of the nervous system and the psychological reality of the mind. The material in this edition is entirely new, with all chapters written specifically for it. Since the publication of the third edition, the field of cognitive neuroscience has made rapid and dramatic advances; fundamental stances are changing and new ideas are emerging. This edition reflects the vibrancy of the field, with research in development and evolution that finds a dynamic growth pattern becoming specific and fixed, and research in plasticity that sees the neuronal systems always changing; exciting new empirical evidence on attention that also verifies many central tenets of longstanding theories; work that shows the boundaries of the motor system pushed further into cognition; memory research that, paradoxically, provides insight into how humans imagine future events; pioneering theoretical and methodological work in vision; new findings on how genes and experience shape the language faculty; new ideas about how the emotional brain develops and operates; and research on consciousness that ranges from a novel mechanism for how the brain generates the baseline activity necessary to sustain conscious experience to a bold theoretical attempt to make the problem of qualia more tractable.

Environmental and Economic Costs of Soil Erosion and Conservation Benefits

Abstract: Soil erosion is a major environmental threat to the sustainability and productive capacity of agriculture. During the last 40 years, nearly one-third of the world's arable land has been lost by erosion and continues to be lost at a rate of more than 10 million hectares per year. With the addition of a quarter of a million people each day, the world population's food demand is increasing at a time when per capita food productivity is beginning to decline.

Rigorous QCD analysis of inclusive annihilation and production of heavy quarkonium

Abstract: A rigorous QCD analysis of the inclusive annihilation decay rates of heavy quarkonium states is presented. The effective-field-theory framework of nonrelativistic QCD is used to separate the short-distance scale of annihilation, which is set by the heavy quark mass M, from the longer-distance scales associated with quarkonium structure. The annihilation decay rates are expressed in terms of nonperturbative matrix elements of four-fermion operators in nonrelativistic QCD, with coefficients that can be computed using perturbation theory in the coupling constant ${\mathrm{\ensuremath{\alpha}}}_{\mathit{s}}$(M). The matrix elements are organized into a hierarchy according to their scaling with v, the typical velocity of the heavy quark. An analogous factorization formalism is developed for the production cross sections of heavy quarkonium in processes involving momentum transfers of order M or larger. The factorization formulas are applied to the annihilation decay rates and production cross sections of S-wave states at next-to-leading order in ${\mathit{v}}^{2}$ and P-wave states at leading order in ${\mathit{v}}^{2}$.

Economic growth, carrying capacity, and the environment.

Abstract: National and international economic policy has usually ignored the environment. In areas where the environment is beginning to impinge on policy, as in the General Agreement on Tariffs and Trade (GATT) and the North American Free Trade Agreement (NAFTA), it remains a tangential concern, and the presumption is often made that economic growth and economic liberalization (including the liberalization of international trade) are, in some sense, good for the environment. This notion has meant that economy-wide policy reforms designed to promote growth and liberalization have been encouraged with little regard to their environmental consequences, presumably on the assumption that these consequences would either take care of themselves or could be dealt with separately. In this article, we discuss the relation between economic growth and environmental quality, and the link between economic activity and the carrying capacity and resilience of the environment.

An empirical investigation of the predictors of executive career success

Abstract: This study examined the degree to which demographic, human capital, motivational, organizational, and industrylregion variables predicted executive career success. Career success was assumed to comprise objective (pay, ascendancy) and subjective (job satisfaction, career satisfaction) elements. Results obtained from a sample of 1,388 U.S. executives suggested that demographic, human capital, motivational, and organizational variables explained significant variance in objective career success and in career satisfaction. Particularly interesting were findings that educational level, quality, prestige, and degree type all predicted financial success. In contrast, only the motivational and organizational variables explained significant amounts of variance in job satisfaction. These findings suggest that the variables that lead to objective career success often are quite different from those that lead to subjectively defined success.

Adaptive phenotypic plasticity: consensus and controversy.

Abstract: Phenotypic plasticity is an environmentally based change in the phenotype. Understanding the evolution of adaptive phenotypic plasticity has been hampered by dissenting opinions on the merits of different methods of description, on the underlying genetic mechanisms, and on the way that plasticity is affected by natural selection in a heterogeneous environment. During much of this debate, the authors of this article have held opposing views. Here, we attempt to lay out current issues and summarize the areas of consensus and controversy surrounding the evolution of plasticity and the reaction norm (the set of phenotypes produced by a genotype over a range of environments).

Cost of mating in Drosophila melanogaster females is mediated by male accessory gland products

Abstract: Female Drosophila melanogaster with environmentally or genetically elevated rates of mating die younger than controls. This cost of mating is not attributable to receipt of sperm. We demonstrate here that seminal fluid products from the main cells of the male accessory gland are responsible for the cost of mating in females, and that increasing exposure to these products increases female death rate. Main-cell products are also involved in elevating the rate of female egg-laying, in reducing female receptivity to further matings and in removing or destroying sperm of previous mates. The cost of mating to females may therefore represent a side-effect of evolutionary conflict between males.

Regulation of organic nutrient metabolism during transition from late pregnancy to early lactation

Abstract: Conceptus energy and nitrogen de- mands in late pregnancy are mostly met by placental uptake of maternal glucose and amino acids. The resulting 30 to 50% increase in maternal requirements for these nutrients is met partly by increased volun- tary intake and partly by an array of maternal metabolic adaptations. The latter include increased hepatic gluconeogenesis from endogenous substrates, decreased peripheral tissue glucose utilization, in- creased fatty acid mobilization from adipose tissue, and, possibly, increased amino acid mobilization from muscle. Within 4 d of parturition, mammary demands for glucose, amino acids, and fatty acids are several- fold those of the pregnant uterus before term. Even unusual postparturient increases in voluntary intake cannot satisfy this increased nutrient demand. There- fore, rates of hepatic gluconeogenesis and adipose fat mobilization are greatly accelerated. Concomitant changes in amino acid metabolism include increased hepatic protein synthesis and, possibly, decreased amino acid catabolism, and increased peripheral mobilization of amino acids. Insulin resistance in adipose tissue and muscle, developed during late pregnancy, continues postpartum; adipose lipolytic responsiveness and sensitivity to adrenergic agents are increased postpartum beyond their levels during late pregnancy. Before parturition, these homeorhetic adjustments may be coordinated with lactogenesis by increased secretion of estradiol and prolactin. Their amplification and reinforcement at and soon after parturition may be regulated mostly by somatotropin.

Synthesis and barrier properties of poly(ε‐caprolactone)‐layered silicate nanocomposites

Abstract: A new polymer-ceramic nanocomposite has been synthesized consisting of well-dispersed, two-dimensional layers of an organically modified mica-type silicate (MTS) within a degradable poly(e-caprolactone) matrix. A protonated amino acid derivative of MTS was used to promote delamination/dispersion of the host layers and initiate ring-opening polymerization of e-caprolactone monomer, resulting in poly(e-caprolactone) chains that are ionically bound to the silicate layers. The polymer chains can be released from the silicate surface by a reverse ion-exchange reaction and were shown to be spectroscopically similar to pure poly(e-caprolactone). Thick films of the polymer nanocomposite exhibit a significant reduction in water vapor permeability that shows a linear dependence on silicate content. The permeability of nanocomposite containing as low as 4.8% silicate by volume was reduced by nearly an order of magnitude compared to pure poly(e-caprolactone)

Linked regularities in the development and evolution of mammalian brains

Abstract: Analysis of data collected on 131 species of primates, bats, and insectivores showed that the sizes of brain components, from medulla to forebrain, are highly predictable from absolute brain size by a nonlinear function. The order of neurogenesis was found to be highly conserved across a wide range of mammals and to correlate with the relative enlargement of structures as brain size increases, with disproportionately large growth occurring in late-generated structures. Because the order of neurogenesis is conserved, the most likely brain alteration resulting from selection for any behavioral ability may be a coordinated enlargement of the entire nonolfactory brain.

Conversation and Cooperation in Social Dilemmas: A Meta-Analysis of Experiments from 1958 to 1992

Abstract: This article presents an analysis of 35 years of published experiments testing decision making in prisoners' dilemmas. The objective is to begin to reconnect the theory and the evidence of rational behavior by accumulating the experience of the laboratory and examining this record for those factors that consistently altered subjects' choices. It is shown that a model of pure self-interest is usually inconsistent with the results of experimental decision making, predicting either the wrong sign, as in the case of monetary stakes, or ignoring influential variables, such as the content of instructions. This incongruity is widest with respect to the role of language in encouraging cooperation.

Perceiving Layout and Knowing Distances: The Integration, Relative Potency, and Contextual Use of Different Information about Depth*

Abstract: Publisher Summary This chapter discusses three questions: Why are there so many sources of information about layout? How is it that one perceives layout with near-metric accuracy when none of these sources yields metric information about it? Can one not do better, theoretically, in understanding the perception of layout than simply make a list? The answer to the first question begins with Todd's answer. Perceiving layout is extremely important to human beings, so important that it must be redundantly specified so that the redundancy can guard against the failure of any given source or the failure of any of the assumptions on which a given source is based. However, information redundancy is only part of the answer. Different sources of information about layout metrically reinforce and contrast with each other, providing a powerful network of constraints. The answer to the second proceeds from this idea. Through the analysis of depth-threshold functions for nine different sources of information about layout, one can begin to understand how those sources of information sharing the same-shaped functions across distances can help ramify judgments of layout by serving to correct measurement errors in each. Third, on the basis of the analyses and the pattern of functions, it suggests that list making has misled about space and layout. Psychologists and other vision scientists have generally considered layout, space, and distance as a uniform commodity in which observers carry out their day-to-day activities.

Human resource strategies and firm performance: what do we know and where do we need to go?

Abstract: This research review focuses on the links between human resource strategies and organizational effectiveness. It is likely that bundles of, or configurations of, activities are more important in enhancing labour productivity than any single activity. However, studies are typically limited in theoretical rigour, have quite small samples and are typically non-cumulative. The empirical basis of strategic human resources management is thus circumscribed.

The experience of regret: what, when, and why

Abstract: This article reviews evidence indicating that there is a temporal pattern to the experience of regret. Actions, or errors of commission, generate more regret in the short term; but inactions, or errors of omission, produce more regret in the long run. The authors contend that this temporal pattern is multiply determined, and present a framework to organize the divergent causal mechanisms that are responsible for it. In particular, this article documents the importance of psychological processes that (a) decrease the pain of regrettable action over time, (b) bolster the pain of regrettable inaction over time, and (c) differentially affect the cognitive availability of these two types of regrets. Both the functional and cultural origins of how people think about regret are discussed.

Long-term follow-up results of a randomized drug abuse prevention trial in a white middle-class population

Abstract: Objective. —To evaluate the long-term efficacy of a school-based approach to drug abuse prevention. Design. —Randomized trial involving 56 public schools that received the prevention program with annual provider training workshops and ongoing consultation, the prevention program with videotaped training and no consultation, or "treatment as usual" (ie, controls). Follow-up data were collected 6 years after baseline using school, telephone, and mailed surveys. Participants. —A total of 3597 predominantly white, 12th-grade students who represented 60.41% of the initial seventh-grade sample. Intervention. —Consisted of 15 classes in seventh grade, 10 booster sessions in eighth grade, and five booster sessions in ninth grade, and taught general "life skills" and skills for resisting social influences to use drugs. Measures. —Six tobacco, alcohol, and marijuana use self-report scales were recoded to create nine dichotomous drug use outcome variables and eight polydrug use variables. Results. —Significant reductions in both drug and polydrug use were found for the two groups that received the prevention program relative to controls. The strongest effects were produced for individuals who received a reasonably complete version of the intervention—there were up to 44% fewer drug users and 66% fewer polydrug (tobacco, alcohol, and marijuana) users. Conclusions. —Drug abuse prevention programs conducted during junior high school can produce meaningful and durable reductions in tobacco, alcohol, and marijuana use if they (1) teach a combination of social resistance skills and general life skills, (2) are properly implemented, and (3) include at least 2 years of booster sessions. ( JAMA . 1995;273:1106-1112)

Nitric Oxide: Pathophysiological Mechanisms

Abstract: Nitric oxide is a double-edged sword. Produced by mammalian cells at an appropriate magnitude and tempo, it serves as a key signaling molecule in physiological processes as diverse as host-defense, neuronal communication, and vascular regulation (for reviews, see 13 1 , 1 32, 172). On the other hand, excessive and unregulated NO synthesis has been implicated as causal or contributing to pathophysiological conditions induding many lethal and de­ bilitating diseases of humans: vascular shock, stroke, diabetes, neurodegenera­ tion, arthritis, and chronic inflammation. Contrary to conventional biosignaling molecules that act by binding to specific receptor molecules, NO manifests its biological actions via a wide range of chemical reactions. NO is a small, relatively stable, free-radical gas that readily diffuses into cells and cell mem­ branes where it reacts with molecular targets. The precise reactions, which are realized in any biological setting, depend on the concentration of NO achieved and often on subtle variations in the composition of the intraand extracellular milieu. This review summarizes the present knowledge of cellular events that lead to NO overproduction in mammalian systems and discusses reactions of NO that may contribute to cell damage or death. Our primary aim is to interpret rather than exhaustively summarize the large body of accumulated NO litera-

Query by humming: musical information retrieval in an audio database

Abstract: The emergence of audio and video data types in databases will require new information retrieval methods adapted to the specific characteristics and needs of these data types. An effective and natural way of querying a musical audio database is by humming the tune of a song. In this paper, a system for querying an audio database by humming is described along with a scheme for representing the melodic information in a song as relative pitch changes. Relevant difficulties involved with tracking pitch are enumerated, along with the approach we followed, and the performance results of system indicating its effectiveness are presented.

Applying Trained Skills on the Job: The Importance of the Work Environment

Abstract: The influence of the work environment on the transfer of newly trained supervisory skills was examined. Participants were 505 supermarket managers from 52 stores. The work environment was operationalized in terms of transfer of training climate and continuouslearning culture. Climate and culture were hypothesized to have both direct and moderating effects on posttraining behaviors. Accounting for pretraining behaviors and knowledge gained in training, the results from a series of LISREL analyses showed that both climate and culture were directly related to posttraining behaviors. In particular, the social support system appeared to play a central role in the transfer of training. Moderating effects were not found. Implications for enhancing the transfer of training are discussed

An Effective Bandwidth Selector for Local Least Squares Regression

Abstract: Local least squares kernel regression provides an appealing solution to the nonparametric regression, or “scatterplot smoothing,” problem, as demonstrated by Fan, for example. The practical implementation of any scatterplot smoother is greatly enhanced by the availability of a reliable rule for automatic selection of the smoothing parameter. In this article we apply the ideas of plug-in bandwidth selection to develop strategies for choosing the smoothing parameter of local linear squares kernel estimators. Our results are applicable to odd-degree local polynomial fits and can be extended to other settings, such as derivative estimation and multiple nonparametric regression. An implementation in the important case of local linear fits with univariate predictors is shown to perform well in practice. A by-product of our work is the development of a class of nonparametric variance estimators, based on local least squares ideas, and plug-in rules for their implementation.

Microprep protocol for extraction of DNA from tomato and other herbaceous plants

Abstract: T he extraction of DNA from plant tissue is a critical and often very time-consuming step in many plant molecular biology procedures. This is especially true for studies of molecular genetics, QTLs, or molecular-marker-based breeding where hundreds or even thousands of plant samples need to be analyzed in a short period of time. Many protocols are laborious and are limited by the need for large amounts of plant tissue. Based on the methods originally described by Murray et al. (1980), we have developed a procedure in our laboratory that maximizes the number of plant samples one person can extract and that yields sufficient DNA for 50 to 100 PCR reactions or two to four Southern blots. The use of very small, new leaves makes it possible to extract DNA from seedlings only one to three weeks old, reducing the need for large amounts of greenhouse space. The entire procedure can be done in 1.5-mL microcentrifuge tubes, eliminating the need for large centrifuges. Using this procedure, one person can isolate DNA from several hundred plants per day. Materials and Solut ions

U-Net: a user-level network interface for parallel and distributed computing

Abstract: The U-Net communication architecture provides processes with a virtual view of a network interface to enable userlevel access to high-speed communication devices. The architecture, implemented on standard workstations using offthe-shelf ATM communication hardware, removes the kernel from the communication path, while still providing full protection. The model presented by U-Net allows for the construction of protocols at user level whose performance is only limited by the capabilities of network. The architecture is extremely flexible in the sense that traditional protocols like TCP and UDP, as well as novel abstractions like Active Messages can be implemented efficiently. A U-Net prototype on an 8node ATM cluster of standard workstations offers 65 microseconds round-trip latency and 15 Mbytes/sec bandwidth. It achieves TCP performance at maximum network bandwidth and demonstrates performance equivalent to Meiko CS-2 and TMC CM-5 supercomputers on a set of Split-C benchmarks.