Showing papers by "University of York published in 1995"

The Wealth and Poverty of Nations: Why Some Are So Rich and Some So Poor

Abstract: Now that the old division of the world into the two power blocs of East and West has subsided, the great gap in wealth and health that separates North and South remains the single greatest problem and danger facing the world of the Third Millennium. The only challenge of comparable scope and difficulty is the threat of the environmental deterioration, and the two are intimately connected, indeed are one. David Landes argues that the North-South division is the great drama of our times, and that drama implies tension, passion, conflict and disappointment as well as happy outcomes. While Landes does not claim to have all the answers, he offers suggestions - although their impact is dependent upon a radical reappraisal of cultural values. Numerous historical examples are drawn together on global history, economics and the future.

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.

Evaluation of comparative protein modeling by MODELLER.

Abstract: We evaluate 3D models of human nucleoside diphosphate kinase, mouse cellular retinoic acid binding protein I, and human eosinophil neurotoxin that were calculated by MODELLER, a program for comparative protein modeling by satisfaction of spatial restraints. The models have good stereochemistry and are at least as similar to the crystallographic structures as the closest template structures. The largest errors occur in the regions that were not aligned correctly or where the template structures are not similar to the correct structure. These regions correspond predominantly to exposed loops, insertions of any length, and non-conserved side chains. When a template structure with more than 40% sequence identity to the target protein is available, the model is likely to have about 90% of the mainchain atoms modeled with an rms deviation from the X-ray structure of approximately 1 A, in large part because the templates are likely to be that similar to the X-ray structure of the target. This rms deviation is comparable to the overall differences between refined NMR and X-ray crystallography structures of the same protein.

Binocular Vision and Stereopsis

Abstract: Introduction 1. Binocular correspondence and the horopter 2. Sensory coding 3. The physiology of binocular vision 4. The limits of stereoscopic vision 5. Matching corresponding images 6. Types of disparity 7. Binocular fusion and rivalry 8. Binocular masking and transfer 9. Vergence eye movements 10. Stereo constancy and depth cue interactions 11. Depth contrrast and cooperative processes 12. Spatiotemporal aspects of stereopsis 13. Vision in the cyclopean domain 14. Development and pathology of binocular vision 15. Binocular and stereoscopic vision in animals References Subject index

On the unintended consequences of publishing performance data in the public sector

Abstract: Most performance indicator schemes in the public sector have been implemented on the assumption that they will yield benefits in terms of efficiency and equity. Less attention has been paid to the potential costs of such schemes. Drawing on experience from a range of sources, this paper identifies eight consequences of publishing performance data that are not necessarily intended, and which are likely to be dysfunctional. The paper gives examples of such phenomena from the UK public sector, and suggests ways in which they can be mitigated. While not challenging the desirability of publishing performance data, the paper concludes that the performance indicator philosophy is based on inadequate models of production and control. Most performance indicator schemes will therefore fail unless serious consideration is given to the deficiencies described in this paper.

Facilitating Emotional Change: The Moment-by-Moment Process

Abstract: I. Introduction 1. Introduction to the Approach 2. A Process Facilitative Approach to Therapy II. Theory: Emotion and Cognition in Change 3. Perspectives on Human Functioning 4. Towards an Experiential Theory of Functioning 5. Dysfunction III. The Manual: Basic Principles and Task-Guided Interventions 1. Treatment Manual: The General Approach 6. Treatment Principles for a Process Experiential Approach 7. What the Therapist Does: Experiential Response Intentions and Modes 2. The Treatment Tasks 8. Systematic Evocative Unfolding at a Marker of a Problematic Reaction Point 9. Experiential Focusing for an Unclear Felt Sense 10. Two Chair Dialogue at a Self-Evaluative Split 11. Two Chair Enactment for Self-Interruption Split 12. Empty-Chair Work and Unfinished Business 13. Empathic Affirmation at a Marker of Intense Vulnerability IV. Conclusion 14. Applying the Process Experiential Approach 15. The Process Experiential Approach: An Overview, Research, Theory, and the Future

One for All: The Logic of Group Conflict

Abstract: In a book that challenges the most widely held ideas of why individuals engage in collective conflict, Russell Hardin offers an explanation of group action in its most destructive forms. Contrary to those observers who attribute group violence to irrationality, primordial instinct, or complex psychology, Hardin uncovers a systematic exploitation of self-interest in the underpinnings of group identification and collective violence. Using examples from Mafia vendettas to ethnic violence in places such as Bosnia and Rwanda, he describes the social and economic circumstances that set this violence into motion. Hardin explains why hatred alone does not necessarily start wars but how leaders cultivate it to mobilize their people. He also reveals the thinking behind the pre-emptive strikes that contribute to much of the violence between groups, identifies the dangers of "particularist" communitarianism, and argues for government structures to prevent any ethnic or other group from having too much sway. Exploring conflict between groups such as Serbs and Croats, Hutu and Tutsi, Northern Irish Catholics and Protestants, Hardin vividly illustrates the danger that arises when individual and group interests merge. In these examples, groups of people have been governed by movements that managed to reflect their members' personal interests - mainly by striving for political and economic advances at the expense of other groups and by closing themselves off from society at large. The author concludes that we make a better and safer world if we design our social institutions to facilitate individual efforts to achieve personal goals than if we concentrate on the ethnic political makeup of our respective societies.

Movement and force produced by a single myosin head

Abstract: MUSCLE contraction is driven by the cyclical interaction of myosin with actin, coupled to the breakdown of ATP. Studies of the interaction of filamentous myosin1 and of a double-headed proteolytic fragment, heavy meromyosin (HMM)2,3, with actin have demonstrated discrete mechanical events, arising from stochastic interaction of single myosin molecules with actin. Here we show, using an optical-tweezers transducer2,4, that a single myosin subfragment-1 (S1), which is a single myosin head, can act as an independent generator of force and movement. Our analysis accounts for the broad distribution of displacement amplitudes observed, and indicates that the underlying movement (working stroke) produced by a single acto-Sl interaction is ~4 nm, considerably shorter than previous estimates1–3,5 but consistent with structural data6. We measure the average force generated by S1 or HMM to be at least 1.7 pN under isometric conditions.

A protein catalytic framework with an N-terminal nucleophile is capable of self-activation

Abstract: The crystal structures of three amidohydrolases have been determined recently: glutamine PRPP amidotransferase (GAT), penicillin acylase, and the proteasome. These enzymes use the side chain of the amino-terminal residue, incorporated in a beta-sheet, as the nucleophile in the catalytic attack at the carbonyl carbon. The nucleophile is cysteine in GAT, serine in penicillin acylase, and threonine in the proteasome. Here we show that all three enzymes share an unusual fold in which the nucleophile and other catalytic groups occupy equivalent sites. This fold provides both the capacity for nucleophilic attack and the possibility of autocatalytic processing. We suggest the name Ntn (N-terminal nucleophile) hydrolases for this structural superfamily of enzymes which appear to be evolutionarily related but which have diverged beyond any recognizable sequence similarity.

Multi-functionality and biodiversity in arbuscular mycorrhizas

Abstract: Plant roots in natural ecosystems are typically colonized by a wide range of fungi. Some of these are pathogenic, others appear to be opportunistic and have no apparent impact, while mycorrhizal fungi are generally regarded as mutualistic. Of the various types of mycorrhizal fungi, the arbuscular mycorrhizal (AM) association is by far the most abundant and widespread. While the most widely accepted model of AM function depends upon plants benefiting from the facilitation of phosphorus uptake, recent data from field-based studies in temperate ecosystems indicate that only plant species with poorly branched root systems benefit from AM fungi in this way: species with highly branched root systems may benefit in other ways, such as by being protected against root pathogenic fungi. These two responses apparently represent extremes along a continuum of AM benefit determined by root system architecture.

Bringing politics back in: Towards a model of the developmental state

Abstract: The few cases of rapid economic growth in the Third World in the last 30 years have occurred in democratic, quasi‐democratic and non‐democratic polities. They are thus clearly not a function of common regime type. I suggest that they are best explained by the special character of their states, understood ‘as developmental states’. This article outlines some common characteristics of these states. However the forms and features of these states are not simply a function of their administrative structures or principles of governance, but of their politics. The article thus also underlines the importance of political analysis in both development theory and policy, from where it has been extruded for too long.

Like Subjects, Love Objects: Essays on Recognition and Sexual Difference

Abstract: From the perspectives of developmental psychoanalysis, this book makes a case for what the author calls gender heterodoxy, an original view of the similarities and differences between the sexes. In the process, she illuminates aspects of love, sexuality, aggression and pornography.

Structure of a 14-3-3 protein and implications for coordination of multiple signalling pathways

Abstract: A BROAD range of organisms and tissues contain 14-3-3 proteins, which have been associated with many diverse functions including critical roles in signal transduction pathways, exocytosis and cell cycle regulation1. We report here the crystal structure of the human T-cell 14-3-3 isoform (τ) dimer at 2.6 A resolution. Each monomer (Mr 28K) is composed of an unusual arrangement of nine antiparallel α-helices organized as two structural domains. The dimer creates a large, negatively charged channel approximately 35 A broad, 35 A wide and 20 A deep. Overall, invariant residues line the interior of this channel whereas the more variable residues are distributed on the outer surface. At the base of this channel is a 16-residue segment of 14-3-3 which has been implicated in the binding of 14-3-3 to protein kinase C.

Simulation and Chaotic Behavior of α-Stable Stochastic Processes

Abstract: Preliminary remarks Brownian motion, poisson process, alpha-stable Levy motion computer simulation of alpha-stable random variables stochastic integration spectral representations of stationary processes computer approximations of continuous time processes examples of alpha-stable stochastic modelling convergence of approximate methods chaotic behaviour of stationary processes hierarchy of chaos for stable and ID stationary processes. Appendix - a guide to simulation.

Understanding and Evaluating Qualitative Research.

Abstract: During the past 6 years (1989-1994), the Journal of Marriage and the Family has published 527 articles. Only 10 or 1.9% were qualitative, either entirely (4) or partly (1), or in a combination of qualitative and quantitative data (5). Four other articles were based on qualitative data, but the results were entirely quantified. These four articles would raise the total of qualitative papers to 15 or 2.8%. These statistics are rather startling, especially when considering that there is a large theoretical literature pertaining to qualitative research, numerous articles and texts on its methods, a rapidly growing body of empirical research with the family field as one of its major beneficiaries (Gilgun, Daly, & Handel, 1992; Rosenblatt & Fischer, 1993), and a well-organized network on qualitative family research, with a newsletter of the same name. JMF, however, is not unique in terms of rarely publishing qualitative articles (see LaRossa & Wolf, 1985; Nye, 1988, on family research). Editorial boards of high-profile journals in family studies, psychology, and sociology are composed of well-published scholars, only a minority of whom are experienced qualitative researchers. The result is that a majority of the qualitative articles submitted have to be evaluated by scholars who have little expertise in qualitative research, or by qualitative researchers who have no expertise in the substantive area of a submitted article or who subscribe to a different epistemology. In contrast, quantitative papers can generally be matched with reviewers who not only understand the methods, but are also knowledgeable in the substantive area covered. It thus becomes important to discuss some of the problems inherent in evaluating qualitative research. Consequently, the focus of this article is practical and not theoretical. We address naturalistic qualitative research in terms of methods. In addition, because qualitative research has become extremely varied, we have limited the purview of this article to epistemologies that involve the observation, interview, or written participation of family members, rather than the analysis or deconstruction of texts, for instance. The statistics presented earlier clearly indicate that JMF is a quantitative journal, with a readership primarily composed of quantitative researchers. We have, therefore, written this article for scholars who are quantitatively oriented: Our vocabulary and material covered reflect this focus. Because several qualitative approaches are included within the vast umbrella of naturalistic fieldwork, we also hope to reach qualitative researchers who are very specialized within one particular epistemology or qualitative approach. In order to retain a certain practical focus, we could not discuss postmodernist approaches. Moreover, because most of us are sociologically trained, the bulk of the literature reviewed falls within this discipline. We use a quantitative/qualitative dichotomy only for heuristic purposes. At a historical juncture where traditional, theoretical, and empirical alignments should at least cohabit and new configurations are appearing (Alexander & Colomy, 1990, p. 56), one can only hope for an improved understanding between advocates of both sets of approaches and a decrease in the either/or dichotomous thinking that devalues the efforts of any one approach to knowledge generation. This hope also extends to adherents of the several distinct qualitative epistemologies. In a first section, we present general information on qualitative research in terms of its goals and procedures. This is followed by a discussion of linkages between epistemologies and methods in qualitative research; our own diverse orientations are outlined at the end of this discussion. In a third section, we broach more specific aspects of the evaluation process. Then we examine frequently encountered problems in the evaluation process, focusing on problems unwittingly created both by reviewers and authors. …

Fixed priority pre-emptive scheduling: an historical perspective

Abstract: From its roots in job-shop scheduling, research into fixed priority pre-emptive scheduling theory has progressed from the artificial constraints and simplistic assumptions used in early work to a sufficient level of maturity that it is being increasingly used in the implementation of real-time systems. It is therefore appropriate that within this special issue we provide an historical perspective on the development of fixed priority pre-emptive scheduling.

Diversity of fungal symbionts in arbuscular mycorrhizas from a natural community

Abstract: summary The arbuscular mycorrhizal (AM) association between fungi in the order Glomales and the roots of a very wide range of vascular plants is of global ecological significance but has proved particularly intractable to study in the field. We have developed a reliable technique to identify the fungal symbionts in roots taken directly from natural communities. Selective Enrichment of Amplified DNA combines the use of recently-developed specific DNA primers with a novel method based on the principle of subtractive hybridization to remove interfering plant-derived DNA after amplification with the polymerase chain reaction. Using this technique we have shown that endomycorrhizas of bluebells (Hyacinthoides non-scripta) sampled directly from a woodland habitat are multispceies communities of varying composition which contain at least three genera of mycorrhizal fungi. The technique works well on a range of plant species and should have wide application to the identification of other symbionts, including pathogens. A spore survey has indicated that two particular AM types are associated with bluebells and this observation corroborates the molecular data. The presence of a Glomus species in bluebell roots was not expected from the spore data.

Release of Ca2+ from Individual Plant Vacuoles by Both InsP3 and Cyclic ADP-Ribose

Abstract: Calcium mobilization from intracellular pools couples many stimuli to responses in plant cells. Cyclic adenosine 5'-diphosphoribose (cADPR), which interacts with a ryanodine receptor in certain animal cells, was shown to elicit calcium release at the vacuolar membrane of beet storage root. The vacuolar calcium release pathway showed similarities to cADPR-gated calcium release in animal cells, including inhibition by ruthenium red, ryanodine activation, and high affinity for cADPR [Michaelis constant (Km) = 24 +/- 7 nanomolar]. Analysis by patch-clamping demonstrated that the cADPR-gated pathway in beet is voltage-dependent over the physiological range, does not spontaneously desensitize, and is colocalized with an inositol 1,4,5-trisphosphate (InsP3)-gated calcium release pathway in individual vacuoles.

Perfectionism traits and perfectionistic self-presentation in eating disorder attitudes, characteristics, and symptoms

Abstract: Objective: The purpose of this study was to assess the association between several dimensions of perfectionism and measures of eating disorder symptoms, body image, and appearance self-esteem in college students. Method: A sample of 81 female university students completed the Multidimensional Perfectionism Scale, the Perfectionistic Self-Presentation Scale, the Eating Attitudes Test, the Bulimia Test, the Body Image Avoidance Questionnaire, and two measures of self-esteem. Results: It was found that whereas self-oriented perfectionism was related only to anorexic symptoms, the social facets of perfectionism, especially socially prescribed perfectionism and the perfectionistic self-presentation dimensions, were related to eating disorder symptoms as well as body image avoidance and self-esteem. Discussion: The findings support the usefulness of differentiating personal and interpersonal dimensions of perfectionism as well as trait versus self-presentational aspects of perfectionism in investigating personality and attitudes and behaviors related to eating disorders. © 1995 by John Wiley & Sons, Inc.

Computer Programs for Qualitative Data Analysis: A Software Sourcebook

Abstract: PART ONE: THE BASICS Introduction How to Choose Software Key Questions Software Types and Functions PART TWO: SOFTWARE REVIEWS Text Retrievers Textbase Managers Code-and-Retrieve Programs Code-Based Theory-Builders Conceptual Network-Builders Program Features A Guide to the Ratings PART THREE: REFLECTIONS AND RESOURCES Reflections and Hopes

Localization of a gene for partial epilepsy to chromosome 10q

Abstract: There is strong evidence for a genetic contribution to epilepsy, but it is commonly assumed that this genetic contribution is limited to 'generalized' epilepsies, and that most forms of 'partial' epilepsy are nongenetic. In a linkage analysis of a single family containing 11 affected individuals, we obtained strong evidence for localization of a gene for partial epilepsy. This susceptibility gene maps to chromosome 10q, with a maximum two-point lod score for D10S192 of 3.99 at theta = 0.0. All affected individuals share a single haplotype for seven tightly linked contiguous markers; the maximum lod score for this haplotype is 4.83 at theta = 0.0. Key recombinants place the susceptibility locus within a 10 centimorgan interval.

The Effect of Breeding Synchrony On Extra-Pair Mating Systems in Songbirds

Abstract: Extra-pair mating systems are now considered to be typical of songbirds because DNA fingerprinting has revealed high rates of extra-pair fertilizations (EPFs) in so many species previously thought to be monogamous. However, there is no general framework to explain the tremendous variability among songbirds in EPF rate. Here, in a comparison of EPF rates and temporal patterns of nesting among songbirds, we show that EPFs are most common in species where females breed synchronously. We argue that for both males and females, a temporal concentration of female fertility (breeding synchrony) increases the net benefits of seeking EPFs. One implication of this finding is that tropical songbirds, most of which breed asynchronously, are predicted to have low levels of extra-pair matings. Testes size is positively correlated with frequency of EPFs, and as predicted, tropical songbirds had small testes size relative to temperate zone species. The few DNA fingerprinting studies that exist for socially monogamous tropical songbirds support the correlation between breeding synchrony and EPFs. We believe that breeding synchrony is the most important factor promoting the evolution of extra-pair mating systems.

Critical exponents, hyperscaling, and universal amplitude ratios for two- and three-dimensional self-avoiding walks

Abstract: We make a high-precision Monte Carlo study of two- and three-dimensional self-avoiding walks (SAWs) of length up to 80,000 steps, using the pivot algorithm and the Karp-Luby algorithm. We study the critical exponentsv and 2Δ 4 −γ as well as several universal amplitude ratios; in particular, we make an extremely sensitive test of the hyperscaling relationdv = 2Δ 4 −γ. In two dimensions, we confirm the predicted exponentv=3/4 and the hyperscaling relation; we estimate the universal ratios /=0.14026±0.00007, /=0.43961±0.00034, and Ψ*=0.66296±0.00043 (68% confidence limits). In three dimensions, we estimatev=0.5877±0.0006 with a correctionto-scaling exponentΔ 1=0.56±0.03 (subjective 68% confidence limits). This value forv agrees excellently with the field-theoretic renormalization-group prediction, but there is some discrepancy forΔ 1. Earlier Monte Carlo estimates ofv, which were ≈0.592, are now seen to be biased by corrections to scaling. We estimate the universal ratios /=0.1599±0.0002 and Ψ*=0.2471±0.0003; since Ψ*>0, hyperscaling holds. The approach to Ψ* is from above, contrary to the prediction of the two-parameter renormalization-group theory. We critically reexamine this theory, and explain where the error lies. In an appendix, we prove rigorously (modulo some standard scaling assumptions) the hyperscaling relationdv = 2Δ 4 −γ for two-dimensional SAWs.

The nature of insight

Abstract: The Greeks had a ready answer for what happens when the mind suddenly finds the answer to a question for which it had been searching: insight was regarded as a gift of the Muses, its origins were ‘divine’. It served to highlight the Greeks' belief that there are some things which are not meant to be scientifically explained. The essence of insight is that it comes from some supernatural source: unpredicted and unfettered. In other words, the origins of insight are unconscious, and hence, unexplainable. Wittgenstein felt that, as long as there continues to be a noun expression like ‘to have a moment of insight’ which functions in the same way as the expression ‘to have a hunger pang’, thereby inducing us to treat ‘moment of insight’ as the name of an experience, then “people will keep stumbling over the same puzzling difficulties and find themselves staring at something which no explanation seems capable of clearing up.” To the founders of AI, this argument reeked of obscurantism. The moment of insight, they felt, is indeed a mystery, but it is one that begs to be explained in causal terms. Indeed, the problem of insight served as one of the leading problems in the evolution of AI. Hence anyone interested in the foundations of AI is compelled to examine the manner in which the early pioneers of the field sought to explain the ‘eureka experience’. In this paper I will look at some of the key conceptual developments which paved the way for Newell and Simon's theory of GPS: the fundamental changes in the notion of the unconscious — the emergence of the ‘cognitive unconscious’ — which took place in the nineteenth- and early twentieth-century. In so doing, I hope to clarify what Wittgenstein may have had in mind in his strictures against mechanist attempts to analyse the nature of insight.