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Theoretical Interest (theoretical + interest)
Selected AbstractsRatio estimators in adaptive cluster samplingENVIRONMETRICS, Issue 6 2007Arthur L. Dryver Abstract In most surveys data are collected on many items rather than just the one variable of primary interest. Making the most use of the information collected is a issue of both practical and theoretical interest. Ratio estimates for the population mean or total are often more efficient. Unfortunately, ratio estimation is straightforward with simple random sampling, but this is often not the case when more complicated sampling designs are used, such as adaptive cluster sampling. A serious concern with ratio estimates introduced with many complicated designs is lack of independence, a necessary assumption. In this article, we propose two new ratio estimators under adaptive cluster sampling, one of which is unbiased for adaptive cluster sampling designs. The efficiencies of the new estimators to existing unbiased estimators, which do not utilize the auxiliary information, for adaptive cluster sampling and the conventional ratio estimation under simple random sampling without replacement are compared in this article. Related result shows the proposed estimators can be considered as a robust alternative of the conventional ratio estimator, especially when the correlation between the variable of interest and the auxiliary variable is not high enough for the conventional ratio estimator to have satisfactory performance. Copyright © 2007 John Wiley & Sons, Ltd. [source] Tuning Specific Biomolecular Interactions Using Electro-Switchable Oligopeptide SurfacesADVANCED FUNCTIONAL MATERIALS, Issue 16 2010Chun L. Yeung Abstract The ability to regulate biomolecular interactions on surfaces driven by an external stimuli is of great theoretical interest and practical impact in the biomedical and biotechnology fields. Herein, a new class of responsive surfaces that rely on electro-switchable peptides to control biomolecular interactions on gold surfaces is presented. This system is based upon the conformational switching of positively charged oligolysine peptides that are tethered to a gold surface, such that bioactive molecular moieties (biotin) incorporated on the oligolysines can be reversibly exposed (bio-active state) or concealed (bio-inactive state) on demand, as a function of surface potential. The dynamics of switching the biological properties is studied by observing the binding events between biotin and fluorescently labeled NeutrAvidin. Fluorescence microscope images and surface plasmon resonance spectral data clearly reveal opposite binding behaviors when +0.3 V or ,0.4 V vs. SCE are applied to the surface. High fluorescence intensities are observed for an applied positive potential, while minimal fluorescence is detected for an applied negative potential. Surface plasmon resonance spectroscopy (SPR) results provided further evidence that NeutrAvidin binding to the surface is controlled by the applied potential. A large SPR response is observed when a positive potential is applied on the surface, while a negative applied potential induces over 90% reduction in NeutrAvidin binding. [source] What do mothers attune to during interactions with their infants?INFANT AND CHILD DEVELOPMENT, Issue 4 2006Carl-Otto Jonsson Abstract There has been considerable theoretical interest in the developmental importance of affect mirroring and attunement, but little empirical attention has been directed toward the topic. The present study systematically explored the sorts of infant behaviour that elicit affect attunement in mothers. Written descriptions of video-recorded sequences of interaction in 27 mother,infant dyads were used to examine 141 instances of affect attunement in samples from Sweden and the former Yugoslavia. Infants were aged between 2 and 12 months. Behaviour that elicited affect attunement from mothers was rated in terms of 10 behavioural themes, which were used to cluster episodes of affect attunement. Cluster analysis suggested that mothers attuned to six distinct forms of infant behaviour: pleasurable motoric behaviour, effect initiation, focusing, loss of balance, uncontrolled behaviour and displeasure. Incidents of affect attunement elicited by categorical affects comprised only 20% of the instances examined. Most importantly, affect attunement was often elicited by infant exploration and play in relation to the non-social world. Affect attunement may function to reinforce and regulate on-going behaviour that is largely explorative in nature. How mothers respond to the infant's interaction with the external, non-social world may be more important for intrapsychic development than previously thought. Copyright © 2006 John Wiley & Sons, Ltd. [source] Large-scale processes in ecology and hydrologyJOURNAL OF APPLIED ECOLOGY, Issue 2000R.W.G. Caldow 1. Several papers published in the 1980s stressed the importance of scaling issues, the inter-relatedness of patterns and processes at different scales of time and space, to our understanding of ecological systems. Scaling issues are of major theoretical interest and increasingly are of considerable applied importance. 2. In recognition of this, the Natural Environment Research Council, in partnership with the Scottish Executive Rural Affairs Department, funded a Thematic Programme entitled ,Large-scale Processes in Ecology and Hydrology'. The principal aim of this Programme was to integrate recent major developments in information resources and technologies with current theory in order to improve understanding of large-scale patterns and processes and their relationship to patterns and processes at smaller scales. 3. The Thematic Programme, which ran from 1995 until 1999, funded six research projects that have generated a large body of published papers. This volume, dedicated to the findings of the Programme, brings together outputs from all six projects with the aim of ensuring a rapid and widespread dissemination of the Programme's findings. A brief résumé of each of the papers is presented. 4. The papers in this volume cover a wide variety of subjects ranging from ions to the flora and fauna of the United Kingdom. Nonetheless, each study has sought in various ways to quantify observed spatio-temporal patterns at a range of scales, to determine whether those patterns are consistent across scales and to identify the interactions between small-scale patterns and processes and those at larger scales. The importance of the spatial and temporal scales at which studies are conducted, the key role played by dispersal in spatial population dynamics, and the diversity of ways in which large-scale patterns and processes relate to those at smaller scales are highlighted in many of the papers. 4. All of the papers presented here have direct relevance to applied issues. These issues are diverse and include the control of invasive alien species, the conservation of declining, threatened or endangered species, the development of survey techniques, strategies for farmland, woodland and forestry management, and the assessment of pollution sensitivity. Thus, the Thematic Programme has addressed issues of considerable theoretical interest and has at the same time generated results and predictive models that are of considerable practical and policy relevance. [source] Spatial patterns of Indian serial burglars with relevance to geographical profilingJOURNAL OF INVESTIGATIVE PSYCHOLOGY AND OFFENDER PROFILING, Issue 2 2006Sudhanshu Sarangi Abstract Earlier studies in Western countries have shown remarkably consistent spatial patterns in serial offenders, mainly for serious crimes notably serial killing and rape, but also (although with less clear patterns) for burglary. The universality of such spatial patterns are of theoretical interest in contributing to our understanding of criminal spatial behaviour and have practical significance for the possibility of using geographic profiling in developing countries. As such, burglars in India provide a particularly interesting test of the generality of the observed spatial consistencies. Information was therefore obtained on the offence location choices of 30 burglars, committing 150 offences in the Rourkela and Keonjhar districts of India. The home to crime distances were compared with those from developed countries, revealing similar but slightly shorter distances. In addition, the domocentricity of criminal spatial activity, reflected in the ,marauder' model (Canter & Gregory 1994) was tested through examination of the Canter Circle hypothesis, the mean interpoint distances (as they related to average distances from home), and the home base ,search costs' using a geographical profiling system (Dragnet). Overall the study found that the spatial patterns of the sample of Indian Burglars were not very different from their counterparts in the UK, North America and Australia, showing that the areas in which an offender is active tend to be shaped by, and, relatedly, close to, where he or she lives, irrespective of the part of the world in which this is. These results suggest that geographical profiling systems such as Dragnet would be productively used on the Indian sub-continent. The results also contribute to our understanding of possible universalities in offender spatial behaviour. Copyright © 2006 John Wiley & Sons, Ltd. [source] Attachment, decay, and social networkJOURNAL OF ORGANIZATIONAL BEHAVIOR, Issue 6 2001Ronald S. Burt To study decay in attachment to an organization, I analyse data on women who obtained an MBA from the University of Chicago's Graduate School of Business (GSB). I measure attachment in terms of network embedding: an alumna is attached to the GSB to the extent that people close to her graduated from the GSB. Behavioral data corroborate the network data in that alumnae measured to be more attached are more likely to have joined an alumni club and made a financial contribution to the school. The hypothesis is that alumnae attachment will decay over time, more slowly when the school is deeply embedded in an alumna's network, more quickly when disruptive events compete for the alumna's time and energy. As expected, attachment declines across the years after graduation (linearly for the first 20 years to about half its initial level), and decay is inhibited when connections with GSB graduates are embedded in stable relations of family, work, or long-term friendship. Decay is remarkably robust to events after graduation (which account for only 2 per cent of explained variance in attachment). In other words, an alumna's attachment today was largely determined while she was in school. The results should be of practical value to people who design programmes to build personal attachment to organizations, and of theoretical interest to scholars who study such connections. Copyright © 2001 John Wiley & Sons, Ltd. [source] Disc degeneration and bone density in monozygotic twins discordant for insulin-dependent diabetes mellitusJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2000T. Videman The effects of insulin-dependent diabetes mellitus on bone density and connective tissue degeneration have theoretical interest and practical relevance. Several experimental studies in animals have demonstrated the harmful effects of insulin deficiency on connective tissues. However, clinical studies in humans have produced somewhat contradictory results, most likely due to difficulties controlling for general degeneration and factors associated with diabetes. In nine pairs of monozygotic twins discordant for insulin-dependent diabetes mellitus, we compared femoral and lumbar bone mineral density (assessed by dualenergy x-ray absorptiometry) and spinal degeneration (assessed by magnetic resonance imaging). The bone densities were, on average, 0.1,0.3% lower (p = 0.87,0.96) in diabetic patients. However, after controlling for smoking, we found that the bone density in the femoral neck was 2.5% (0.025 g/cm2) lower in diabetic individuals than in their twins (p = 0.09). The five magnetic resonance imaging parameters used to evaluate discdegeneration did not differ between diabetic patients and their twins. In conclusion, our results provide no evidence that insulin-dependent diabetes mellitus has any major effect on bone density or disc degeneration. [source] Investigating the interaction between the homeostatic and circadian processes of sleep,wake regulation for the prediction of waking neurobehavioural performanceJOURNAL OF SLEEP RESEARCH, Issue 3 2003Hans P. A. Van Dongen Summary The two-process model of sleep regulation has been applied successfully to describe, predict, and understand sleep,wake regulation in a variety of experimental protocols such as sleep deprivation and forced desynchrony. A non-linear interaction between the homeostatic and circadian processes was reported when the model was applied to describe alertness and performance data obtained during forced desynchrony. This non-linear interaction could also be due to intrinsic non-linearity in the metrics used to measure alertness and performance, however. Distinguishing these possibilities would be of theoretical interest, but could also have important implications for the design and interpretation of experiments placing sleep at different circadian phases or varying the duration of sleep and/or wakefulness. Although to date no resolution to this controversy has been found, here we show that the issue can be addressed with existing data sets. The interaction between the homeostatic and circadian processes of sleep,wake regulation was investigated using neurobehavioural performance data from a laboratory experiment involving total sleep deprivation. The results provided evidence of an actual non-linear interaction between the homeostatic and circadian processes of sleep,wake regulation for the prediction of waking neurobehavioural performance. [source] Smoothed Particle Magnetohydrodynamics , III.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2005Multidimensional tests, ·B= 0 constraint ABSTRACT In two previous papers (Papers I and II), we have described an algorithm for solving the equations of Magnetohydrodynamics (MHD) using the Smoothed Particle Hydrodynamics (SPH) method. The algorithm uses dissipative terms in order to capture shocks and has been tested on a wide range of one-dimensional problems in both adiabatic and isothermal MHD. In this paper, we investigate multidimensional aspects of the algorithm, refining many of the aspects considered in Papers I and II and paying particular attention to the code's ability to maintain the ,·B= 0 constraint associated with the magnetic field. In particular, we implement a hyperbolic divergence cleaning method recently proposed by Dedner et al. in combination with the consistent formulation of the MHD equations in the presence of non-zero magnetic divergence derived in Papers I and II. Various projection methods for maintaining the divergence-free condition are also examined. Finally, the algorithm is tested against a wide range of multidimensional problems used to test recent grid-based MHD codes. A particular finding of these tests is that in Smoothed Particle Magnetohydrodynamics (SPMHD), the magnitude of the divergence error is dependent on the number of neighbours used to calculate a particle's properties and only weakly dependent on the total number of particles. Whilst many improvements could still be made to the algorithm, our results suggest that the method is ripe for application to problems of current theoretical interest, such as that of star formation. [source] A new dawn , the ecological genetics of mycorrhizal fungiNEW PHYTOLOGIST, Issue 2 2000D. LEE TAYLOR Many human activities, such as ore mining and smeltering, sewage sludge treatment and fossil fuel consumption, result in toxic soil concentrations of ,heavy metals' (Al, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Ti, Zn and others) (Gadd, 1993). There are also natural soils, such as serpentine, with levels of heavy metals that inhibit or preclude the growth of many plants and soil micro-organisms. However, certain plants and microorganisms do grow in these metalliferous sites. Understanding the physiology, ecology and evolution of tolerance to elevated soil metal concentrations is important in an applied setting, and is also of interest in theoretical biology. Applied importance relates to the improvement of forest health in areas subject to increasing pollution, rehabilitation of severely polluted sites by phytostabilization of metals, and metal removal using hyperaccumulating plants (Krämer, 2000; Ernst, 2000). Areas of theoretical interest include the evolution of local adaptation (Sork et al., 1993) and how it is shaped by the combined influences of natural selection, gene flow and genetic architecture, as well as metal influences on various species interactions (Pollard, 2000). A paper appears on pages 367,379 in this issue by Jan Colpaert and coworkers which adroitly combines the disparate fields of physiology, genetics and ecology to answer several outstanding questions concerning heavy metal tolerance in mycorrhizal fungi. Mycorrhizal fungi, which interact mutualistically with the majority of plant species, are well known for improving the P status of their hosts (Smith & Read, 1997). Some mycorrhizal fungi are also able to mobilize N and P from organic substrates and to provide plants with improved micronutrient and water acquisition, pathogen resistance, and a variety of other benefits (Smith & Read, 1997). One of these additional benefits is the amelioration of toxicity in metalliferous soils. [source] Constant rate allocation in nymphal development in species of HemipteraPHYSIOLOGICAL ENTOMOLOGY, Issue 4 2003Dionyssios CH. Abstract., This study investigated the existence of rate isomorphy (the constant allocation of relative times to different stages of development under different abiotic conditions) in Macrolophus pygmaeus (Hemiptera: Miridae; a phytophagous and predatory insect). Replicated data were used from a range of temperatures regarding (i) the developmental period of each nymphal stage in relation to the total duration of nymph development, when feeding on three host plants either with different prey species or without prey, and (ii) its egg, total nymphal and preoviposition period, on two host plants, with different prey species. The proportion of time required for the development of each nymphal stage of M. pygmaeus is not different among the temperatures or the kind of food available. These proportions ranged among the different host plants, temperatures and prey presence/absence from 17.3,21.8% in the first, 14.5,18.8% in the second, 14.2,18.3% in the third, 16.5,21.0% in the fourth and from 25.4,30.6% in the fifth nymphal stage. Thus, temperature does not significantly affect the proportion of time spent in each nymphal stage and rate isomorphy exists in nymphal development. This phenomenon was also investigated using data from the literature, and it also occurs in several other Hemiptera species. Therefore, there appears to be a constant time allocation in the nymphal development of the higher taxonomic groups of insects. However, for M. pygmaeus, rate isomorphy does not hold when considering egg-to-egg development and the relative duration of times to egg hatch, total nymphal development and preoviposition period. The ecophysiological implications of this rate isomorphy phenomenon are discussed in relation to endocrinological mechanisms. Apart from its theoretical interest, the existence of rate isomorphy simplifies studies on the rate of development and the estimation of thermal constants of an insect, which are essential for the prediction of insect population dynamics. It is also proposed that the term ,rate isomorphy' does not strictly describe the phenomenon, and it is suggested that ,constant rate allocation' would be a more suitable term. [source] What can the Social Sciences Contribute to the Study of Ethics?BIOETHICS, Issue 2 2002Empirical, Substantive Considerations, Theoretical This article seeks to establish that the social sciences have an important contribution to make to the study of ethics. The discussion is framed around three questions: (i) what theoretical work can the social sciences contribute to the understanding of ethics? (ii) what empirical work can the social sciences contribute to the understanding of ethics? And (iii) how does this theoretical and empirical work combine, to enhance the understanding of how ethics, as a field of analysis and debate, is socially constituted and situated? Through these questions the argument goes beyond the now commonly cited objection to the over-simplistic division between normative and descriptive ethics (that assigns the social sciences the ,handmaiden' role of simply providing the ,facts'). In extending this argument, this article seeks to establish, more firmly and in more detail, that: (a) the social sciences have a longstanding theoretical interest analysing the role that a concern with ethics plays in explanations of social change, social organisation and social action; (b) the explanations that are based on the empirical investigations conducted by social scientists exemplify the interplay of epistemological and methodological analyses so that our understanding of particular substantive issues is extended beyond the conventional questions raised by ethicists, and (c) through this combination of theoretical and empirical work, social scientists go beyond the specific ethical questions of particular practices to enquire further into the social processes that lie behind the very designation of certain matters as being ,ethical issues'. [source] Order and disorder: the contradictions of childhoodCHILDREN & SOCIETY, Issue 1 2000Roger Smith This article reviews the question of childhood in the context of conflicting social trends, namely the simultaneous globalisation and atomisation of social life. The experience of childhood is discussed in relation to three distinct ,levels'; children as consumers, children as interpreters, and children as actors. It is suggested that understanding the changing social context in relation to each of these levels helps to explain some of the tensions and disruptions that characterise the lives of some children, especially those at the margins. In conclusion, it is argued that this analysis is not only of theoretical interest, but indicates specific requirements for the formulation of coherent social policies to meet the needs of all children. Copyright © 2000 John Wiley & Sons, Ltd. [source] Materialising Oceania: New ethnographies of things in Melanesia and PolynesiaTHE AUSTRALIAN JOURNAL OF ANTHROPOLOGY, Issue 1 2009Joshua A. Bell Oceania occupies an intriguing place within anthropology's genealogy. In the introduction to this collection of essays, we examine the role of the ethnography of Oceania in the development of our anthropological perspectives on materialisation, the dynamic process by which persons and things are inter-related. Building upon the recent resurgence of theoretical interests in things we use the term materialisation (rather than material culture or materiality) to capture the vitality of the lived processes by which ideas of objectivity and subjectivity, persons and things, minds and bodies are entangled. Taking a processual view, we advocate for an Oceanic anthropology that continues to engage with things on the ground; that asks what strategies communities use to materialise their social relations, desires and values; and that recognises how these processes remain important tools for understanding historical and contemporary Oceanic societies. Examining these locally articulated processes and forms contributes to a material (re)turn for anthropology that clarifies how we, as scholars, think about things more widely. [source] The fractal yam: botanical imagery and human agency in the TrobriandsTHE JOURNAL OF THE ROYAL ANTHROPOLOGICAL INSTITUTE, Issue 4 2009Mark S. Mosko Anthropologists have long appreciated that animals are ,good to think'. In this essay I ponder whether plants might be good to think too, and particularly whether there is any sense in asking if plants (along with animals) might also be ,good to act'. The botanical metaphor of ,base', ,body', and ,tip' animates the origin structures of many if not most societies of the Austronesian world. Less attention has been directed at indigenous elaborations in other socio-cultural domains of the region. Based on recent fieldwork, I outline such ramifications in Trobriand culture, drawing upon the notions of fractal recursion and self-similarity from chaos theory wherein emergent ,tips' yield ,fruit' which become the condition or ,base' for further production and transformation. Accordingly, the base-body-tip-fruit metaphor serves as a cultural template or scenario for social action, shedding new interpretative light on many topics of long-standing anthropological interest (e.g. yam propagation, display, and exchange, kula, mortuary celebration, age categories, fame) as well as more recent theoretical interests. Résumé Les anthropologues ont compris il y a longtemps déjà que les animaux sont « bons à penser ». Dans cet essai, l'auteur se demande si les plantes sont elles aussi bonnes à penser, et en particulier s'il vaut la peine de se demander si les plantes (comme les animaux) pourraient être « bonnes à agir ». La métaphore botanique de « base », « corps » et « tête » anime les structures originelles de beaucoup de sociétés du monde austronésien, sinon toutes. On s'est moins intéressé aux élaborations indigènes de la région dans d'autres domaines socioculturels. Sur la base d'un récent travail de terrain, l'auteur retrace ces ramifications dans la culture trobriandaise, utilisant les notions de récursivité fractale et d'autosimilitude de la théorie du chaos, selon lesquelles les « têtes » donnent des « fruits » qui deviennent la condition ou « base » d'une nouvelle production et transformation. En conséquence, la métaphore base-corps-tête-fruit sert de modèle culturel ou de scénario d'action sociale, jetant un nouvel éclairage interprétatif sur de nombreux sujets qui intéressent depuis longtemps les anthropologues (tels que la propagation, la présentation et l'échange des ignames, la kula, les célébrations mortuaires, les classes d'âge, la renommée), mais aussi sur de nouvelles questions théoriques plus récentes. [source] A meta-analysis of the verbal overshadowing effect in face identificationAPPLIED COGNITIVE PSYCHOLOGY, Issue 6 2001Christian A. Meissner Recent studies have demonstrated that requesting individuals to produce a verbal description of a previously seen face can hinder subsequent attempts at identification. This phenomenon, termed ,verbal overshadowing', has been studied rather extensively in the face-identification paradigm; however, studies have not always replicated the general effect. Based upon both practical and theoretical interests in the phenomenon, a meta-analysis of 29 effect size comparisons (N,=,2018) was conducted. Across the sample of studies there was a small, yet significant, negative effect (Fisher's Zr,=,,0.12), indicating some degree of verbal impairment or overshadowing. A fixed-effects analysis of several moderating variables demonstrated a significant effect of post-description delay and type of description instruction. The pattern of means indicated that overshadowing effects were more likely to occur when the identification task immediately followed the description task, and when participants were given an elaborative, as opposed to a standard (free recall), instruction during the description task. Inconsistencies in the literature are discussed, as well as various theoretical and applied issues regarding the verbal overshadowing effect. Copyright © 2001 John Wiley & Sons, Ltd. [source] | ||||||||||||||||