Showing papers by "Stony Brook 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.

Logical foundations of object-oriented and frame-based languages

Abstract: We propose a novel formalism, called Frame Logic (abbr., F-logic), that accounts in a clean and declarative fashion for most of the structural aspects of object-oriented and frame-based languages. These features include object identity, complex objects, inheritance, polymorphic types, query methods, encapsulation, and others. In a sense, F-logic stands in the same relationship to the object-oriented paradigm as classical predicate calculus stands to relational programming. F-logic has a model-theoretic semantics and a sound and complete resolution-based proof theory. A small number of fundamental concepts that come from object-oriented programming have direct representation in F-logic; other, secondary aspects of this paradigm are easily modeled as well. The paper also discusses semantic issues pertaining to programming with a deductive object-oriented language based on a subset of F-logic.

Inducing Features of Random Fields

Abstract: We present a technique for constructing random fields from a set of training samples. The learning paradigm builds increasingly complex fields by allowing potential functions, or features, that are supported by increasingly large subgraphs. Each feature has a weight that is trained by minimizing the Kullback-Leibler divergence between the model and the empirical distribution of the training data. A greedy algorithm determines how features are incrementally added to the field and an iterative scaling algorithm is used to estimate the optimal values of the weights. The statistical modeling techniques introduced in this paper differ from those common to much of the natural language processing literature since there is no probabilistic finite state or push-down automaton on which the model is built. Our approach also differs from the techniques common to the computer vision literature in that the underlying random fields are non-Markovian and have a large number of parameters that must be estimated. Relations to other learning approaches including decision trees and Boltzmann machines are given. As a demonstration of the method, we describe its application to the problem of automatic word classification in natural language processing. Key words: random field, Kullback-Leibler divergence, iterative scaling, divergence geometry, maximum entropy, EM algorithm, statistical learning, clustering, word morphology, natural language processing

Citizens, Politics and Social Communication: Information and Influence in an Election Campaign

Abstract: Acknowledgments Part I. Democratic Politics and Social Communication: 1. The multiple levels of democratic politics 2. A research strategy for studying electoral politics Part II. Electoral Dynamics and Social Communication: 3. The social dynamics of political preference 4. Durability, volatility and social influence 5. Social dynamics in an election campaign Part III. Networks, Political Discussants, and Social Communication: 6. Political discussion in an election campaign 7. Networks in context: The social flow of political information 8. Choice, social structure, and the informational coercion of minorities 9. Discussant effects on vote choice: Intimacy, structure, and interdependence 10. Gender effects on political discussion: The political networks of men and women Part IV. The Organizational Locus of Social Communication: 11. One-party politics and the voter revisited: strategic and behavioral bases of partisanship 12. Political parties and electoral mobilization: political structure, social structure, and the party canvass 13. Alternative contexts of political preference 14. Political consequences of interdependent citizens Bibliography Index.

Bipolar disorders in a community sample of older adolescents : prevalence, phenomenology, comorbidity, and course

Abstract: Objective The purpose of this study was to examine the prevalence, clinical characteristics, and mental health treatment services utilization of adolescents with bipolar disorders and manic symptoms. Method Structured diagnostic interviews were administered to a representative community sample of 1,709 older adolescents (aged 14 through 18 years). Results The lifetime prevalence of bipolar disorders (primarily bipolar II disorder and cyclothymia) was approximately 1%. An additional 5.7% of the sample reported having experienced a distinct period of abnormally and persistently elevated, expansive, or irritable mood even though they never met criteria for bipolar disorder ("core positive" subjects). The rate of manic symptoms in these subjects was similar to that reported in clinical samples, and the course of bipolar disorder was relatively chronic. Compared with adolescents with a history of major depression ( n = 316) and a "never mentally ill" group ( n = 845), the bipolar and core positive subjects both exhibited significant functional impairment and high rates of comorbidity (particularly with anxiety and disruptive behavior disorders), suicide attempts, and mental health services utilization. Conclusions These data highlight the clinical and public health significance of even the milder and subthreshold cases of bipolar disorder in adolescence.

Risk factors for open-angle glaucoma. The Barbados Eye Study.

Abstract: Objective: To evaluate risk factors for open-angle glaucoma among black participants in the Barbados Eye Study. Design: Population-based study of demographic, medical, ocular, familial, and other factors possibly related to open-angle glaucoma. Setting and Participants: The Barbados Eye Study included 4709 Barbados residents identified by a simple random sample of Barbadian-born citizens, 40 to 84 years of age; participation was 84%. This report is based on the 4314 black participants examined at the study site; 302 (7%) met the Barbados Eye Study criteria for open-angle glaucoma. Data Collection: A standardized protocol included applanation tonometry, Humphrey perimetry, fundus photography, blood pressure, anthropometry, and an interview. An ophthalmologic examination was performed for participants who met specific criteria. Main Outcome Measures: Open-angle glaucoma was defined by the presence of both characteristic visual field defects and optic disc damage. Association of open-angle glaucoma with specific factors was evaluated in logistic regression analyses. Results: Age, male gender, high intraocular pressure, and family history of open-angle glaucoma were major risk factors; the latter association was stronger in men than women. Lean body mass and cataract history were the only other factors related to open-angle glaucoma. Although hypertension and diabetes were common in Barbados Eye Study participants, they were unrelated to the prevalence of open-angle glaucoma. However, associations were found with low diastolic blood pressure-intraocular pressure differences and low systolic and diastolic blood pressure/intraocular pressure ratios. Conclusions: In the Barbados Eye Study black population, persons most likely to have open-angle glaucoma were older men and had a family history of open-angle glaucoma, high intraocular pressure, lean body mass, and cataract history. These results suggest the importance of possible genetic or familial factors in open-angle glaucoma. The role of vascular risk factors is consistent with our finding of low blood pressure to intraocular pressure relationships, but the results could be explained by the high intraocular pressure in open-angle glaucoma.

Shape, relative size, and size‐adjustments in morphometrics

Abstract: Many problems in comparative biology and biological anthropology require meaningful definitions of “relative size” and “shape” Here we review the distinguishing features of ratios and residuals and their relationships to other methods of “size-adjustment” for continuous data Eleven statistical techniques are evaluated in reference to one broadly interspecific data set (craniometries of adult Old World monkeys) and one narrowly intraspecific data set (anthropometries of adult Native American males) Three different types of residuals are compared to three versions of shape ratios, and these are contrasted to “cscores,” Penrose shape, and multivariate adjustments based on the first principal component of the logged variance-covariance matrix; all methods are also compared to raw and logged raw data In order to help us identify appropriate; methods for size-adjustment, geometrically similar or “isometric” versions of the male vervet and the Inuit male were created by scalar multiplication of all variables The geometric mean of all variables is used as overall “size” throughout this investigation, but our conclusions would be the same for most other size variables Residual adjustments failed to correctly identify individuals of the same shape in both sampkles Like residuals, cscores are also sample-specific and incorrectly attribute different shape values to individuals known to be identical in shape Multivariate “residuals” (eg, discarding the first principal component and Burnaby's method) are plagued by similar problems If one of the goals of an analysis is to identify individuals (OTUs) of the same shape after accounting for overalll size differences, then none of these methods can be recommended We also reject the assertion that size-adjusted variables should be unciorrelated with size of “size-free”; rather, whether or not shape covaries with size is an important empirical determination in any analysis Without explicit similarity criteria, “lines of subtraction” can be very misleading Only variables in the Mosimann family of shape rations allowed us to identify sized individuals of the same shape (“Iso-OUTs”) Residuals from isometric lines in logarithmic space, projections of logged data to a plane orthogonal to an isometric vector, and Penrose shape distance based on logged data are also part of this shape family Shape defined in this manner can be significantly correlated with size in allometric data sets (eg, guenon craniometrics); ratio shape differences may be largely independent of size in narrowly intraspecific or intrasexual data sets (eg, Native American anthropometrics) Log-transformations of shape variables are not always necessary or desirable We hope our findings enciourage other workers to question the assumptions and utility of residuals as size-adjusted data and to explore shape and relative size within Mosimann's explicitly geometric framework © 1995 Wiley-Liss, Inc

Excitotoxin-induced neuronal degeneration and seizure are mediated by tissue plasminogen activator

Abstract: Neuronal degeneration in the hippocampus, a region of the brain important for acquisition of memory in humans, occurs in various pathological conditions, including Alzheimer's disease, brain ischaemia and epilepsy. When neuronal activity is stimulated in the adult rat and mouse hippocampus, tissue plasminogen activator (tPA), a serine protease that converts inactive plasminogen to the active protease plasmin, is transcriptionally induced. The activity of tPA in neural tissue is correlated with neurite outgrowth, regeneration and migration, suggesting that it might be involved in neuronal plasticity. Here we show that tPA is produced primarily by microglia in the hippocampus. Using excitotoxins to induce neuronal cell loss, we demonstrate that tPA-deficient mice are resistant to neuronal degeneration. These mice are also less susceptible to pharmacologically induced seizures than wild-type mice. These findings identify a role for tPA in neuronal degeneration and seizure.

Is Methylphenidate Like Cocaine?: Studies on Their Pharmacokinetics and Distribution in the Human Brain

Abstract: Background: The purposes of this study were to investigate the pharmacokinetics of methylphenidate hydrochloride (Ritalin) in the human brain, to compare them with those of cocaine, and to evaluate whether cocaine and methylphenidate compete for the same binding sites. Methods: We used positron emission tomography to measure the temporal and spatial distribution of carbon 11 (11C)-labeled methylphenidate. These results were compared with those obtained previously for [11C]cocaine. Eight healthy male subjects, 20 to 51 years of age, were scanned with [11C]methylphenidate. Three were tested twice to assess test-retest variability, four were tested at baseline and after administration of methylphenidate, and one was tested with [11C]methylphenidate and [11C]cocaine. Two baboons were scanned to evaluate whether there was competition between cocaine and methylphenidate for the same binding sites in the brain. Results: The uptake of [ 11 C] methylphenidate in the brain was high (mean±SD, 7.5%±1.5%), and the maximal concentration occurred in striatum. Pretreatment with methylphenidate decreased binding only in striatum (40%). Although the regional distribution of [ 11 C]methylphenidate was identical to that of [ 11 C] cocaine and they competed with each other for the same binding sites, these two drugs differed markedly in their pharmacokinetics. Clearance of [ 11 C]methlphenidate from striatum (90 minutes) was significantly slower than that of [ 11 C]cocaine (20 minutes). For both drugs, their fast uptake in striatum paralleled the experience of the "high." For methylphenidate, the high decreased very rapidly despite significant binding of the drug in the brain. In contrast, for cocaine, the decline in the high paralleled its fast rate of clearance from the brain. Conclusion: We speculate that because the experience of the high is associated with the fast uptake of cocaine and methylphenidate in the brain, the slow clearance of methylphenidate from the brain may serve as a limiting factor in promoting its frequent self-administration.

Perirhinal and postrhinal cortices of the rat: A review of the neuroanatomical literature and comparison with findings from the monkey brain

Abstract: This review is prompted by recent findings that the perirhinal and parahippocampal cortices in the monkey brain are important components of the medial temporal lobe memory system. Given the potential impor- tance of the comparable regions to memory function in the rat brain, it is surprising that so little is known about their neuroanatomy. In fact, there are no comprehensive studies of the borders, cytoarchitecture, or connec- tions of the cortical regions surrounding the posterior portion of the rhi- nal sulcus in the rat. This review is meant to summarize the current state of our knowledge regarding these regions in the rat brain. Based on exist- ing data and our own observations, a new terminology is introduced that retains the term perirhinal cortex for the rostral portion of the region and renames the caudal portion the postrhinal cortex. Issues of continuing un- certainty are highlighted, and information gleaned from the monkey liter- ature is used to predict what anatomical traits the rat perirhinal region might demonstrate upon further examination. To the extent possible with available data, the similarities and differences of the rat and monkey perirhi- nal, postrhinal, and parahippocampal regions are evaluated.

Can multi-source feedback change perceptions of goal accomplishment, self-evaluations, and performance-related outcomes? theory-based applications and directions for research

Abstract: Multi-source feedback extends traditional performance appraisal by collecting information from subordinates, peers, supervisors, and customers. Ratees often receive the results along with normative data and self-ratings. This paper explores how multi-source feedback goes beyond traditional performance appraisal by providing ratees with comparative information. Focusing on person perception and information processing dynamics, this paper develops a model and associated propositions to explain the effects of multi-source feedback on perceptions of goal accomplishment, re-evaluation of self-image, and changes in outcomes such as goals, development, behavior, and performance. Moderators of relationships between the major components in the model include individual difference variables (self-image, feedback seeking, self-monitoring, task-specific self-efficacy, and impression management) and situational conditions (the content and process of multi-source feedback and organizational performance standards). Issues of research and practice intended to improve understanding and effectiveness of multi-source feedback are discussed.

A lunar occultation and direct imaging survey of multiplicity in the Ophiuchus and Taurus star-forming regions

Abstract: We present an IR lunar occultation and direct imaging search for companions in the Ophiuchus star-forming region and update a similar search of the Taurus region. The search is sensitive to companions in the angular separation range 0.005-10 sec. In Ophiuchus, we surveyed 35 young star targets; this sample contains at least 10 binaries, two triples, and one quadruple. Ten of the companion stars are newly discovered. In Taurus, the survey now includes 47 systems among which there are at least 22 binaries and four triples. Only two companion stars are newly identified because there is strong overlap with prior work. All the triples and quadruple are hierarchical. The observed binary frequency in Ophiuchus, in the 3-1400 AU range of separations, is at least 1.1 +/- 0.3 that of the nearby solar-like stars. This value is a lower bound because we make no corrections for incompleteness. In Taurus, in the same range of separations, the observed binary frequency is at least 1.6 +/- 0.3 that of the nearby solar-like stars. This value extends Ghez et al.'s (1993) and Leinert's et al.'s (1993) determination of an excess binary frequency to 3 AU separation. We used the weak-line T Tauri star/T Tauri star (WT/TT) type and the K-L color index to distinguish between systems with and without inner disks. We find no convincing difference in the binary frequency or distribution of separations of the systems with and without inner disks. The 1.3 mm continuum emission of the single systems exceeds that of the multiples suggesting that their extensive outer disks are more massive. The specific angular momenta of the binaries overlap those of molecular cloud cores measured by Goodman et al. (1993).

Self-control: Beyond commitment

Abstract: Self-control, so important in the theory and practice of psychology, has usually been understood introspectively. This target article adopts a behavioral view of the self (as an abstract class of behavioral actions) and of self-control (as an abstract behavioral pattern dominating a particular act) according to which the development of self-control is a molar/molecular conflict in the development of behavioral patterns. This subsumes the more typical view of self-control as a now/later conflict in which an act of self-control is a choice of a larger but later reinforcer over a smaller but sooner reinforcer. If at some future time the smaller-sooner reinforcer will be more valuable than the larger-later reinforcer, self-control may be achieved through a commitment to the largerlater reinforcer prior to that point. According to some, there is a progressive internalization of commitment in the development of self-control. This presents theoretical and empirical problems. In two experiments – one with pigeons choosing between smallersooner and larger-later reinforcers, the other with adult humans choosing between short-term particular and long-term abstract reinforcers – temporal patterning of choices increased self-control.

Analyzing protein-protein interactions using two-hybrid system.

Abstract: Publisher Summary This chapter presents the analysis of protein–protein interactions using two-hybrid system. Protein-protein interactions play a critical role in most biological processes. The studies defining domains of proteins that are responsible for specific interactions have contributed significantly to unraveling the mechanisms of tumorigenesis. The two-hybrid system is a yeast-based genetic assay for detecting protein– protein interactions in vivo. It can be used to establish interactions between two known proteins or to search genomic or cDNA libraries for proteins that interact with a target protein. For this latter application, the gene encoding the protein that interacts with a target protein is immediately available on a plasmid, which is not the case for many biochemical methods to detect interacting proteins. The two-hybrid system has also been used to define the protein domains that mediate an interaction and to identify specific residues that are involved in a protein–protein interaction. The chapter also discusses the basis for this method and presents the protocols that are necessary to use this system.

ac Josephson Effect in a Single Quantum Channel.

Abstract: We have calculated all the components of the current in a short one-dimensional channel between two superconductors for arbitrary voltages and transparencies $D$ of the channel. We demonstrate that in the ballistic limit ( $D\ensuremath{\simeq}1$) the crossover between the quasistationary evolution of the Josephson phase difference $\ensuremath{\phi}$ at small voltages and transport by multiple Andreev reflections at larger voltages can be described as the Landau-Zener transition induced by finite reflection in the channel. For perfect transmission and vanishing energy relaxation rates the stationary current-phase relation is never recovered, and $I(\ensuremath{\phi}){\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}I}_{c}\ensuremath{\mid}\mathrm{sin}\ensuremath{\phi}/2\ensuremath{\mid}\mathrm{sgn}V$ for arbitrary small voltages.

Ventral mesodermal patterning in Xenopus embryos: expression patterns and activities of BMP-2 and BMP-4.

Abstract: We provide a comparative analysis of the expression patterns and ventral mesoderm-inducing properties of Xenopus BMP-2 and BMP-4. Transcripts for BMP-2 and BMP-4 are maternally stored in eggs, and zygotic expression of these genes is uniform in the ectoderm and mesoderm in late blastulae. During gastrulation, BMP-2 is expressed at a low level throughout the ectoderm and marginal zone, but at early neurula stages a patch of dorso-anterior cells displays enhanced expression. In contrast, BMP-4 transcripts are restricted to the ventrolateral marginal zone during gastrulation, and in late gastrula and early neurula BMP-4 is expressed in the epidermis but not the neural plate. At post-neurula stages, BMP-2 and BMP-4 transcripts are associated with a variety of mesodermal structures, including the pharyngeal pouches, heart, blood island, and blastopore. At tailbud stages, BMP-2 and BMP-4 are expressed in neural tissues including the neural tube and brain. In mesoderm induction assays, BMP-2 and BMP-4 induce Xhox3, an early ventral-posterior mesoderm marker, and larval βT1 globin, a marker for red blood cells. Induction of red blood cells in response to BMP-4 was demonstrated by staining with a hemoglobin-specific reagent. Little is known about factors that induce hematopoietic lineages in vertebrates, and these results provide evidence linking BMP activity and blood differentiation. Globin induction by BMP-2 and BMP-4 is blocked by co-expression of a dominant-negative activin receptor, suggesting that either endogenous activin signals are required for BMP-mediated induction, or that the trancated activin receptor interferes with signaling by BMP receptors. In assays on marginal zone explants, we demonstrate that BMP-4 respecifies dorsal mesoderm to form ventral mesoderm, consistent with its ability to induce blood and to ventralize embryos. BMP-2, however, does not display such activity. The findings extend and support evidence that BMP-2 and BMP-4 function in ventral mesoderm induction and patterning in Xenopus. Our data furthermore high light the multiple functions these factors fulfill during early vertebrate embryogenesis. © 1995 Wiley-Liss, Inc.

Evidence for a higher pH in the glacial ocean from boron isotopes in foraminifera

Abstract: RECORDS of past changes in the pH of the oceans should provide insights into how the carbonate chemistry of the oceans has changed over time. The latter is related to changes in the atmospheric CO2 content, such as that which occurred during the last glacial-interglacial transition1. Previous studies2,3 have shown that the fractionation of boron isotopes between sea water and precipitated carbonate minerals is pH-dependent. This finding has been used to reconstruct the evolution of ocean pH over the past 20 million years by analyses of boron isotopes in the carbonate shells of foraminifera4. Here we use the same approach to estimate changes in ocean pH between the last glacial and the Holocene period. We estimate that the deep Atlantic and Pacific oceans had a pH 0.3±0.1 units higher during the last glaciation. The accompanying change in carbonate ion concentration is sufficient to account for the decrease in atmospheric pco2 during the glacial period1. These results are consistent with the hypothesis5 that the low CO2 content of the glacial atmosphere was caused by an increased ratio of organic carbon to carbonate in the 'rain' to the sea floor, which led to an increase in carbonate ion concentration (and thus in pH) of deep water without a corresponding increase in the lysocline depth.

The IRAS 1.2 Jy Survey: Redshift Data

Abstract: We present the redshift data for a survey of galaxies selected from the data base of the Infrared Astronomical Satellite (IRAS). This survey extends the 1.936 Jy sample of Strauss et al. (1992) from a flux limit of 1.936 Jy at 60 microns to 1.2 Jy. The survey extension consists of 3920 sources in the flux interval 1.2 - 1.936 Jy, of which 2663 are galaxies with measured redshifts. Fourteen objects (0.52%) do not have redshifts. The survey covers 87.6% of the sky. The data for the complete 1.2 Jy survey (the data presented here in addition to that of Strauss \etal 1992) may be obtained in a machine-readable form from the National Space Science Data Center and from the anonymous ftp site given above.