Home About us Contact
|
Home About us Contact | ||
|
|
||
Spatial Proximity (spatial + proximity)
Selected AbstractsSex and age differences in juvenile social priorities in female philopatric, nondespotic blue monkeysAMERICAN JOURNAL OF PRIMATOLOGY, Issue 3 2010Marina Cords Abstract Juveniles should choose social partners on the basis of both current and future utility. Where one sex is philopatric, one expects members of that sex to develop greater and sex-typical social integration with group-mates over the juvenile period. Where a partner's position in a dominance hierarchy is not associated with services it can provide, one would not expect juveniles to choose partners based on rank, nor sex differences in rank-based preferences. We tested these ideas on 39 wild juvenile (3.2,7.4,years) blue monkeys (Cercopithecus mitis stuhlmanni), cercopithecines with strict female philopatry and muted hierarchies. We made focal animal observations over 6 months, and computed observed:expected amounts of proximity time, approaches and grooming given to various social partners. Overall, our results agree with the hypothesis that juvenile blue monkeys target social partners strategically. Spatial proximity, approaches and active grooming showed similar patterns regarding juvenile social preferences. Females were far more sociable than males, groomed more partners, reciprocated grooming more frequently, and preferred,while males avoided,infants as partners. Older juveniles (5,7 years) spent more time than younger juveniles (3,4,years) near others, and older females were especially attracted to infants. Close kin, especially mothers and less consistently adult sisters, were attractive to both male and female juveniles, regardless of age. Both sexes also preferred same-sex juveniles as social partners while avoiding opposite-sex peers. Juveniles of both sexes and ages generally neither preferred nor avoided nonmaternal adult females, but all juveniles avoided adult males. Partner's rank had no consistent effect on juveniles' preference, as expected for a species in which dominance plays a weak role. Juveniles' social preferences likely reflect both future and current benefits, including having tolerant adult kin to protect them against predators and conspecifics, same-sex play partners, and, for females, infants on which to practice mothering skills. Am. J. Primatol. 72:193,205, 2010. © 2009 Wiley-Liss, Inc. [source] Structural information from quadrupolar nuclei in solid state NMRCONCEPTS IN MAGNETIC RESONANCE, Issue 3 2006Sharon E. Ashbrook Abstract Solid-state NMR has become the method of choice for determining details of molecular-level structure in heterogeneous systems. Though spin-1/2 nuclei still form the core of most such studies, quadrupolar nuclei are increasingly being used. This review assesses what is currently possible, from achieving high-resolution spectra for quadrupolar nuclei (a prerequisite for most structure determination work), to forming correlation spectra which give qualitative details of spatial proximity of nuclei and the determination of internuclear distances, between quadrupolar spins and quadrupolar and spin-1/2 nuclei. Examples are given of each method discussed, and the advantages and disadvantages of the various experiments for different possible applications are assessed. © 2006 Wiley Periodicals, Inc. Concepts Magn Reson Part A 28A: 183,248, 2006. [source] The "End of Geography" in Financial Services?ECONOMIC GEOGRAPHY, Issue 4 2000Local Embeddedness, Territorialization in the Interest Rate Swaps Industry Abstract: This paper provides evidence that the globalization of financial services has not undermined the importance of local embeddedness in world financial centers, among global banks. Using qualitative data from interviews with senior bankers in the interest rate swaps (derivatives) industry in Australia, in this paper I demonstrate the importance of spatial relationships and processes of local embeddedness in the production of swaps. Local embeddedness is attributable to the rapid exchange of financial information in formal dealing networks that serve as central information sources, enabling dealers to formulate a "market feel" that influences their dealing strategies. Information interpretation and decision making in dealing processes and specialist financial labor provide the foundations for the product-based learning orientation of swaps dealing. Dealing networks are underpinned by social relationships, requiring face-to-face interaction that is facilitated by spatial proximity. Although the global swaps industry is dominated by multinational banks, the centrality of these embedded networks impedes globalization in interest rate swaps dealing. The global swaps industry comprises an international network of highly localized but interconnected operations based in world financial centers. [source] Mobile locations: construction of home in a group of mobile transnational professionalsGLOBAL NETWORKS, Issue 1 2007MAGDALENA NOWICKA Abstract How do professionals constitute their homes under conditions of extensive mobility? The study is based on interviews with professionals working for an international organization who are chronically mobile. Despite their high mobility, they describe little difficulty constructing homes. Home can best be understood here not as a fixed location, but as a set of relationships, to both humans and non-humans. There are elements of spatial proximity, but also of distance, and homes may be defined by both objects present and excluded. They may be a focal point, but at the same time part of a heterogeneous network that spans localities as well as binds past and present. Home is therefore territorially defined, but only as an extended network rather than as a bounded location. [source] Ecological correlates of vulnerability to fragmentation in Neotropical batsJOURNAL OF APPLIED ECOLOGY, Issue 1 2008Christoph F. J. Meyer Summary 1In the face of widespread human-induced habitat fragmentation, identification of those ecological characteristics that render some species more vulnerable to fragmentation than others is vital for understanding, predicting and mitigating the effects of habitat alteration on biodiversity. We compare hypotheses on the causes of interspecific differences in fragmentation sensitivity using distribution and abundance data collected on 23 species of Neotropical bats. 2Bats were captured over a 2-year period on 11 land-bridge islands in Gatún Lake, Panama, and on the adjacent mainland. We derived a series of explanatory variables from our capture data and from the literature: (1) natural abundance in continuous forest, (2) body mass, (3) trophic level, (4) dietary specialization, (5) vertical stratification, (6) edge-sensitivity, (7) mobility, (8) wing morphology (aspect ratio and relative wing loading) and (9) ecologically scaled landscape indices (ESLIs). After phylogenetic correction, these variables were used separately and in combination to assess their association with two indices of fragmentation sensitivity, species prevalence (proportion of islands occupied) as well as an index of change in abundance. 3Model selection based on Akaike's information criterion identified edge-sensitivity as the best correlate of vulnerability to fragmentation. Natural abundance and mobility or traits linked to mobility (relative wing loading and ESLI) received limited support as predictors. Vulnerability of gleaning animalivorous bats is probably caused by a combination of these traits. 4Synthesis and applications. Our findings emphasize the importance of a local-scale approach in developing predictive models of species fragmentation sensitivity and indicate that risk assessments of Neotropical bats could be based on species tolerance to habitat edges and mobility-related traits. We suggest that, in order to be effective, management efforts should aim to minimize the amount of edge-habitat and reduce the degree of fragment-matrix contrast. Moreover, if high bat diversity is to be preserved in fragmented Neotropical landscapes, conservation measures regarding reserve design should assure spatial proximity to source populations in larger tracts of continuous forest and a low degree of remnant isolation. [source] Spatially heterogeneous stochasticity and the adaptive diversification of dormancyJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 10 2009E. Rajon Abstract Diversified bet-hedging, a strategy that leads several individuals with the same genotype to express distinct phenotypes in a given generation, is now well established as a common evolutionary response to environmental stochasticity. Life-history traits defined as diversified bet-hedging (e.g. germination or diapause strategies) display marked differences between populations in spatial proximity. In order to find out whether such differences can be explained by local adaptations to spatially heterogeneous environmental stochasticity, we explored the evolution of bet-hedging dormancy strategies in a metapopulation using a two-patch model with patch differences in stochastic juvenile survival. We found that spatial differences in the level of environmental stochasticity, restricted dispersal, increased fragmentation and intermediate survival during dormancy all favour the adaptive diversification of bet-hedging dormancy strategies. Density dependency also plays a major role in the diversification of dormancy strategies because: (i) it may interact locally with environmental stochasticity and amplify its effects; however, (ii) it can also generate chaotic population dynamics that may impede diversification. Our work proposes new hypotheses to explain the spatial patterns of bet-hedging strategies that we hope will encourage new empirical studies of this topic. [source] Chemically selective soft X-ray patterning of polymersJOURNAL OF SYNCHROTRON RADIATION, Issue 2 2007Jian Wang The chemically selective modification of polymer mixtures by monochromated soft X-rays has been explored using the high-brightness fine-focused 50,nm beam of a scanning transmission X-ray microscope. Four different polymer systems were examined: a polymethylmethacrylate (PMMA) polyacrylonitrile (PAN) bilayer film; a PMMA- blend -PAN microphase-separated film; a poly(MMA- co -AN) copolymer film; and a poly(ethyl cyanoacrylate) homopolymer film. A high level of chemically selective modification was achieved for the PMMA/PAN bilayer; in particular, irradiation at 288.45,eV selectively removed the carbonyl group from PMMA while irradiation at 286.80,eV selectively reduced the nitrile group of PAN, even when these irradiations were carried out at the same (x,y) position of the sample. In the last two homogenous polymer systems, similar amounts of damage to the nitrile and carbonyl groups occurred during irradiation at either 286.80 or 288.45,eV. This is attributed to damage transfer between the C[triple-bond]N and C=O groups mediated by primary electrons, secondary electrons or radical/ionic processes, aided by their close spatial proximity. Although the overall thickness of the bilayer sample at 70,nm is smaller than the lateral line spreading of 100,nm, the interface between the layers appears to effectively block the transport of energy, and hence damage, between the two layers. The origins of the line spreading in homogeneous phases and possible origins of the damage blocking effect of the interface are discussed. To demonstrate chemically selective patterning, high-resolution multi-wavelength patterns were created in the PMMA/PAN bilayer system. [source] NMR spectroscopy of citrate in solids: cross-polarization kinetics in weakly coupled systemsMAGNETIC RESONANCE IN CHEMISTRY, Issue 5 2008Jian Feng Abstract Solid-state NMR spectroscopy is a potentially powerful method for obtaining molecular level structural information crucial for understanding the specific relationship between calcite crystals and occluded organic molecules that are important in biomineralization and biomimetic materials. In this work, a method is developed based on cross-polarization/magic angle spinning (CP/MAS) NMR to measure the heteronuclear distances and obtain structural information for large intracrystalline citrate defects in a synthetic calcite/citrate composite. Using compounds with well-characterized crystal structures, Mg(II) citrate and Sr(II) citrate, a correlation is established between TIS, the CP time, and M2IS, the van Vleck heteronuclear dipolar second moment, which contains distance and structural information. This correlation is supported by peak assignments obtained from calculations of the 13C chemical shifts for crystalline Mg(II) citrate. On the basis of TIS,1versusM2IS correlation, measurement of TIS for carbonate ions associated with citrate defects in a calcite(13C-enriched)/citrate coprecipitate yields an estimate for the distance between citrate and the nearest carbonate carbon that indicates close spatial proximity and provides useful constraints for future computational study. The applicability of TIS,1versusM2IS correlations to other weakly coupled spin-1/2 systems is discussed in terms of the effects of 1H homonuclear dipolar coupling, using the CP kinetics of Zn(II) dihydroxybenzoate and kaolinite for comparison. The results suggest a limited range of correlation constants and indicate that quantitative information can be obtained from CP/MAS kinetics obtained under similar experimental conditions. Copyright © 2008 John Wiley & Sons, Ltd. [source] Recurrent nuclear DNA introgression accompanies chloroplast DNA exchange between two eucalypt speciesMOLECULAR ECOLOGY, Issue 7 2010G. E. MCKINNON Abstract Numerous studies within plant genera have found geographically structured sharing of chloroplast (cp) DNA among sympatric species, consistent with introgressive hybridization. Current research is aimed at understanding the extent, direction and significance of nuclear (nr) DNA exchange that accompanies putative cpDNA exchange. Eucalyptus is a complex tree genus for which cpDNA sharing has been established between multiple species. Prior phylogeographic analysis has indicated cpDNA introgression into the widespread forest species Eucalyptus globulus from its rare congener E. cordata. In this study, we use AFLP markers to characterize corresponding nrDNA introgression, on both a broad and fine spatial scale. Using 388 samples we examine (i) the fine-scale spatial structure of cp and nrDNA introgression from E. cordata into E. globulus at a site in natural forest and (ii) broad-scale patterns of AFLP marker introgression at six additional mixed populations. We show that while E. globulus and E. cordata retain strongly differentiated nuclear gene pools overall, leakage of nrDNA occurs at mixed populations, with some AFLP markers being transferred to E. globulus recurrently at different sites. On the fine scale, different AFLP fragments show varying distances of introgression into E. globulus, while introgression of cpDNA is extensive. The frequency of E. cordata markers in E. globulus is correlated with spatial proximity to E. cordata, but departs from expectations based on AFLP marker frequency in E. cordata, indicating that selection may be governing the persistence of introgressed fragments in E. globulus. [source] Generational consciousness and retirement communitiesPOPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 4 2007Kevin E. McHugh Abstract Time and collective historical experience loom large in the formation of generations. I argue that spatial proximity cements generational consciousness among seniors in Arizona retirement communities who identify themselves as members of the Second World War generation. The argument twins Karl Mannheim's social-historical conception of generations and Hannah Arendt's political philosophy which underscores the space of appearance in the public realm in identity formation. It is through congregating, interacting and conversing on a daily basis that seniors in retirement enclaves affirm and reaffirm who they are, both to themselves and outsiders. I draw upon a suite of Arizona case studies, 1988,2000, in revealing ,voices' for a slice of the Second World War generation. Discussions revolving around family, community and national life reveal beliefs and values coalescing around four themes: (1) splendid isolation; (2) dissolution of values; (3) absence of children; and (4) fraying the social compact. The space of appearance within retirement enclaves engenders a strong sense of collective identity and belonging in ageing and, simultaneously, leads to questions about implications and consequences of intergenerational separation. I conclude with a poignant multigenerational experience as suggestive of the potency of intergenerational contact and exchange. Copyright © 2007 John Wiley & Sons, Ltd. [source] Kinship and social bonds in female chimpanzees (Pan troglodytes)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 10 2009Kevin Langergraber A large body of theoretical and empirical research suggests that kinship influences the development and maintenance of social bonds among group-living female mammals, and that human females may be unusual in the extent to which individuals form differentiated social relationships with nonrelatives. Here we combine behavioral observations of party association, spatial proximity, grooming, and space use with extensive molecular genetic analyses to determine whether female chimpanzees form strong social bonds with unrelated individuals of the same sex. We compare our results with those obtained from male chimpanzees who live in the same community and have been shown to form strong social bonds with each other. We demonstrate that party association is as good a predictor of spatial proximity and grooming in females as it is in males, that the highest party association indices are consistently found between female dyads, that the sexes do not differ in the long-term stability of their party association patterns, and that these results cannot be explained as a by-product of the tendency of females to selectively range in particular areas of the territory. We also show that close kin (i.e. mother,daughter and sibling dyads) are very rare, indicating that the vast majority of female dyads that form strong social bonds are not closely related. Additional analyses reveal that "subgroups" of females, consisting of individuals who frequently associate with one another in similar areas of the territory, do not consist of relatives. This suggests that a passive form of kin-biased dispersal, involving the differential migration of females from neighboring communities into subgroups, was also unlikely to be occurring. These results show that, as in males, kinship plays a limited role in structuring the intrasexual social relationships of female chimpanzees. Am. J. Primatol. 71:840,851, 2009. © 2009 Wiley-Liss, Inc. [source] Exchange, affiliation, and protective interventions in semifree-ranging brown capuchin monkeys (Cebus apella)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 8 2006Renata G. Ferreira Abstract The "social intelligence" hypothesis proposes that intelligence evolved as a consequence of the need for behavioral maneuvering to deal with the complexities of social life. As a result, coalitions have received considerable attention. Here we present the patterns of coalitionary behavior observed in a semifree-ranging group of Cebus apella and explore the effects of kinship, spatial proximity, and rank. In contrast to descriptions of Old World monkeys and to some descriptions of capuchins, kinship did not influence the pattern of coalitionary behavior, although individuals tended to help those that remained in close proximity. Rank had the greatest influence on coalitions: those that interfered in conflicts (often the alpha) were higher ranking than both contestants and supported the most subordinate (younger) interactant. However, rank did not influence the coalitionary support when conflicts involved only adults. We found no evidence that individuals were making use of triadic knowledge, and most of the coalitions can best be described as protective interventions involving immatures. The overall low rate of coalitions may be due to a period of social stability. Am. J. Primatol. 68:765,776, 2006. © 2006 Wiley-Liss, Inc. [source] X-ray and 13C solid-state NMR studies of N -benzoyl-phenylalanineCHEMICAL BIOLOGY & DRUG DESIGN, Issue 4 2000M.J. Potrzebowski Abstract: A crystalline sample of N -benzoyl- dl -phenylalanine 1 and a polycrystalline sample of N -benzoyl- l -phenylalanine 2 were studied using 13C high-resolution solid-state NMR spectroscopy. The X-ray structure of the dl form was established. Sample 1 crystallizes in a monoclinic form with a P21/c space group, a = 11.338(1) Å, b = 9.185(1) Å, c = 14.096(2) Å, ,,= 107.53(3)°, V = 1400(3) Å3, Z = 4 and R = 0.053. The principal elements of the 13C chemical shift tensors ,ii for 1 and 2, selectively 13C (99%) labeled at the carboxyl groups were calculated. On the basis of 13C ,ii analysis the hydrogen bonding pattern for sample 2 was deduced. Enriched samples were used to establish the intermolecular distance between chemically equivalent nuclei for 1 and spatial proximity in heterogeneous domain for 2, employing the ODESSA pulse sequence. The consistence of the complementary approach covering X-ray data, analysis of the 13C ,ii parameters and ODESSA results is revealed. [source] | ||||||||||||||||