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Proximity Effects (proximity + effects)
Selected AbstractsNO COMMUNITY IS AN ISLAND: THE EFFECTS OF RESOURCE DEPRIVATION ON URBAN VIOLENCE IN SPATIALLY AND SOCIALLY PROXIMATE COMMUNITIES,CRIMINOLOGY, Issue 3 2006DANIEL P. MEARS The link between resource deprivation and urban violence has long been explored in criminological research. Studies, however, have largely ignored the potential for resource deprivation in particular communities to affect rates of violence in others. The relative inattention is notable because of the strong theoretical grounds to anticipate influences that extend both to geographically contiguous areas and to those that, though not contiguous, share similar social characteristics. We argue that such influences,what we term spatial and social proximity effects, respectively,constitute a central feature of community dynamics. To support this argument, we develop and test theoretically derived hypotheses about spatial and social proximity effects of resource deprivation on aggregated and disaggregated homicide counts. Our analyses indicate that local area resource deprivation contributes to violence in socially proximate communities, an effect that, in the case of instrumental homicides, is stronger when such communities are spatially proximate. We conclude by discussing the implications of our findings for theories focused on community-level social processes and violence, and for policies aimed at reducing crime in disadvantaged areas. [source] Steric and Electronic Effects on an Antibody-Catalyzed Diels,Alder ReactionHELVETICA CHIMICA ACTA, Issue 12 2002Yael Gozin A series of substituted thiophene dioxides was tested as diene substrates for the antibody 1E9, which was elicited with a hexachloronorbornene derivative and normally catalyzes the inverse electron-demand Diels,Alder reaction between 2,3,4,5-tetrachlorothiophene dioxide (TCTD) and N -ethylmaleimide (NEM). Previous structural and computational studies had suggested that the catalytic efficiency of this system derives in part from a very snug fit between the apolar active site and the transition state of this reaction. Nevertheless, replacing all the Cl-atoms in the hapten with Br-atoms leads to no loss in affinity (Kd=0.1,nM), indicating substantial conformational flexibility in the residues that line the binding pocket. Consistent with this observation, the 2,3,4,5-tetrabromothiophene dioxide is a good substrate for the antibody (kcat=1.8,min,1, KNEM=14,,M), despite being considerably larger than TCTD. In contrast, normal electron-demand Diels,Alder reactions between NEM and unsubstituted thiophene dioxide or 2,3,4,5-tetramethylthiophene dioxide, which are much smaller or nearly isosteric with TCTD, respectively, are not detectably accelerated. These results show that the electronic properties of the 1E9 active site are optimized to a remarkable degree for the inverse electron-demand Diels,Alder reaction for which it was designed. Indeed, they appear to play a more important role in catalysis than simple proximity effects. [source] Diagnostic osteology and analysis of the Mid- to Late Holocene dynamics of shags and cormorants in Tierra del FuegoINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 2 2007D. Causey Abstract We present here illustrated characteristics and anatomical descriptions of features that can be used to discriminate between four common skeletal elements (i.e. humerus, coracoid, femur, tarsometatarsus) of the five species of shags and cormorants known to occur in southern South America. We also present a detailed study of their distribution and abundance from about 6000 years before present to historical times as revealed by identification of faunal material excavated earlier and by re-analysis of material published previously. Our results present a high-resolution examination of the avian resource base used by early human hunters, and provide a foundation for future studies on the palaeoavifauna of Tierra del Fuego during the Mid- to Late Holocene. On the broadest scales, species diversity of the Phalacrocoracidae is qualitatively stable over space and time, a pattern that is also reflected in the larger marine bird community. On a finer scale, however, our results indicate that the abundance and distribution of cormorants and shags in Mid- and Late Holocene zooarchaeological deposits varied in a complex manner through time. These patterns do not appear to be related to proximity effects of hunters to colonies, but to other factors possibly associated with environmental change. Copyright © 2006 John Wiley & Sons, Ltd. [source] Ring current and steric effects on 1H chemical shifts of Ru coordinated 2,2, -bipyridylsMAGNETIC RESONANCE IN CHEMISTRY, Issue 12 2003Sydney Brownstein Abstract Ring current and proximity effects may be responsible for both low- and high-frequency shifts of the aromatic protons of Ru coordinated bipyridyls according to the different geometries depending on whether two or three bipyridyls are coordinated. Copyright © 2003 Crown in the right of Canada. Published by John Wiley & Sons, Ltd. [source] | ||||||||||