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81.
Past studies consistently indicate measurable local associations between alcohol distribution and the incidence of violence. These results, coupled with measurements of spatial correlation, reveal the importance of spatial analysis in the study of the interaction of alcohol and violence. While studies increasingly incorporate spatial correlation among model residuals to improve precision and reduce bias, to date, most analyses assume associations that are constant and independent of location, an assumption coming under increasing scrutiny in the quantitative geography literature. In this paper, we review and contrast two approaches for the estimation of and inference for spatially heterogeneous effects (i.e., associative factors whose impacts on the outcome of interest vary throughout geographic space). Specifically, we provide an in-depth comparison of “geographically weighted regression” models (allowing covariate effects to vary in space but only allowing relatively ad hoc inference) with “variable coefficient” models (allowing varying effects via spatial random fields and providing model-based estimation and inference, but requiring more advanced computational techniques). We compare the approaches with respect to underlying conceptual structures, computational implementation, and inferential output. We apply both approaches to violent crime, illegal drug arrest, and alcohol distribution data from Houston, Texas and compare results in light of the differing methodological structures of the two approaches.  相似文献   
82.
The neighbouring towns of Haparanda and Tornio, separated only by a narrow strip of grass and wetland, are divided by the only inhabited land boundary between Finland and Sweden in the southern part of the Torne River. The population represents four different groups in relation to linguistic and cultural backgrounds. In the daily lives of the inhabitants, the state boundary is probably of less significance than linguistic, social and ‘ethnic’ differences. On the local government level there is a strong will to unite forces to make the total area a viable region in spite of its peripheral location, but state legislation makes co-ordination difficult. This may be seen as a necessity, but in the daily lives of the populations, the state boundary defines an area of unequal access, sometimes working in favour of and sometimes barring contacts and co-operation. The media consumption reflects a clear ‘national’ interest with a strong local bias. In their attitudes, Finnish speakers and bilinguals show a greater appreciation of ‘the other’ than unilingual Swedes. This may reflect the actual possibility space (reach) in the local area. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
83.
A new early Late Triassic paleopole for Adria has been obtained from the Val Sabbia Sandstone in the Southern Alps. As Early Permian and Jurassic-Cretaceous paleomagnetic data from para-autochthonous regions of Adria such as the Southern Alps are consistent with ‘African’ APWPs[1–2], paleomagnetic data from this region can be used to bolster the West Gondwana APWP in the poorly known Late Permian-Triassic time interval. The Southern Alpine paleopoles are integrated with the West Gondwana and Laurussia APWPs of Van der Voo [1] and used to generate a tectonic model for the evolution of Pangea. The Early Permian overall mean paleopole for West Gondwana and Adria, in conjunction with the coeval Laurussia paleopole, support Pangea B of Morel and Irving [3]. The Late Permian/Early Triassic and the Middle/Late Triassic paleopoles from Adria and Laurussia support Pangea A-2 of Van der Voo and French [4]. The phase of transcurrent motion between Laurasia and Gondwana[5] that caused the Pangea B to A-2 transition occurred essentially in the Permian (at the end of Variscan orogeny) with an average relative velocity of approximately 10 cm/yr. Finally, the Late Triassic/Early Jurassic paleopoles from West Gondwana and Laurussia agree with Pangea A-1 of Bullard et al. [6], the widely accepted Pangea configuration at the time of the Jurassic breakup.  相似文献   
84.
85.
Aerobic biodegradation of vapor-phase petroleum hydrocarbons was evaluated in an intact soil core from the site of an aviation gasoline release. An unsaturated zone soil core was subjected to a flow of nitrogen gas, oxygen, water vapor, and vapor-phase hydrocarbons in a configuration analogous to a biofilter or an in situ bioventing or sparging situation. The vertical profiles of vapor-phase hydrocarbon concentration in the soil core were determined by gas chromatography of vapor samples. Biodegradation reduced low influent hydrocarbon concentrations by 45 to 92 percent over a 0.6-m interval of an intact soil core. The estimated total hydrocarbon concentration was reduced by 75 percent from 26 to 7 parts per million. Steady-state concentrations were input to a simple analytical model balancing advection and first-order biodegradation of hydrocarbons. First-order rate constants for the major hydrocarbon compounds were used to calibrate the model to the concentration profiles. Rate constants for the seven individual hydrocarbon compounds varied by a factor of 4. Compounds with lower molecular weights, fewer methyl groups, and no quaternary carbons tended to have higher rate constants. The first-order rate constants were consistent with kinetic parameters determined from both microcosm and tubing cluster studies at the field site.  相似文献   
86.
We determined tidal, diel (day-night), and diurnal (day to day) patterns of occurrence for the summer zooplankton assemblage in an intertidal salt marsh basin at North Inlet Estuary, South Carolina. In one time series, 153 μm pump and 365 μm net collections were made every 1–2 h during four consecutive tidal cycles. Taxonomic composition remained unchanged throughout most of the 48-h period, but densities and proportionalities of individual taxa were highly variable. Recurring patterns of abundance were observed and taxon-specific relationships with the tidal and diel cycles were indicated. Zooplankton were not uniformly distributed within flooding-ebbing water masses and distributions could not be explained by simple passive advection with the tides. Diel differences in densities of copepods and bivalves resulted from behavioral responses to changing light conditions. Large pulses of crab and shrimp larvae originating from nocturnal hatching events within the intertidal basin exited but did not return during the next flood tide. Higher densities of postlarval decapods on flood tides indicated settlement and recruitment to the shallow basin. In a second time series, replicated collections of the 153 μm and 365 μm assemblages were made during the daytime ebb tide every 1–3 d from May through October 1991 to determine relationships between diurnal changes in depth, salinity, and temperature and zooplankton composition and abundance. Diurnal variations in densities and proportionalities were less than those observed during the 48-h study and patterns were not regular. For most taxa, relationships between depth and abundance were the same in both time series. During periods of reduced salinity, densities of copepods,Uca zoeae, and barnacle nauplii decreased and densities ofUca megalopae andPenaeus postlarvae increased. However, zoeae emerged and postlarvae recruited throughout the 5-mo period, indicating that considerable flexibility in responses and tolerances existed within the populations. The diversity of life-history strategies and behavioral adaptations found among the zooplankton assures continuous occupation of flooded intertidal habitats. We suspect that the evolution and maintenance of temporally staggered recurring patterns of occurrence results in reductions in the competition for resources.  相似文献   
87.
Organic-rich samples derived from a Middle Cambrian Formation in the Georgina Basin, and from the Middle Proterozoic of the McArthur Basin in northern and central Australia, yielded alginite ranging from immature oil shale material to overmature residue. A maturation scale has been developed based on the thermal evolution of alginite as determined from reflectance and fluorescence. The coalification path of alginite is marked by jumps in contrast to the linear path of wood-derived vitrinite. Six zones have been recognised, ranging from undermature (zone I), through the mature (zones II/III), followed by a stable stage of no change (zone IV) to the overmature (zones V and VI). The onset of oil generation in alginite as evident from the present study is at 0.3% Ro Alg. and is expressed in a change of fluorescence from yellow to brown, and a coalification jump from 0.3 to 0.6% Ro of Alg. In many boreholes zone III can be distinguished between 0.6 and 0.8% Ro of Alg. where subsequent oil generation occurs. Zones II and III represent the oil window.A zone of little or no change designated zone IV, at of alginite follows zones II/III. A marked coalification jump characterises zone V, where a pronounced change in reflectance occurs to >1.0% Ro Alg., signifying peak gas generation. The border of oil preservation lies at the transition of zone V and VI, at 1.6% Ro Alg. In zone VI gas generation only occurs.Comparison of reflectance results with experimental and geochemical pyrolysis data supports high activation energies for hydrocarbon generation from alginite, and therefore a later onset of oil generation than other liptinite macerals (i.e. cutinite, exinite, resinite) as well as a narrow oil window.Transmission electron microscopy (TEM) confirms that alginite does not go through a distinct intermediate stage but that the percentage of unreacted organic matter decreases as maturation proceeds. A clear distinction can be made in TEM between immature alginite, alginite after oil generation, and alginite residue following gas generation. Alginite beyond 1.6% Ro acquires very high densities and the appearance of inertinite in TEM.Bitumens/pyrobitumens make a pronounced contribution to the organic matter throughout the basins and have been shown to effect pyrolysis results by suppressing Tmax. The bitumens/pyrobitumens have been divided into four groups, based on their reflectance and morphology, which in turn appears to be an expression of their genetic history. Their significance is in aiding the understanding of the basins' thermal history, and the timing of oil and gas generation.  相似文献   
88.
Activities to provide energy for an expanding population are increasingly disrupting and changing the concentration of atmospheric gases that increase global temperature. Increased CO2 and temperature have a clear effect on growth and production of rice as they are key factors in photosynthesis. Rice yields could be increased with increased levels of CO2, however, the rise of CO2 may be accompanied by an increase in global temperature. The effect of doubling CO2 levels on rice production was predicted using rice crop models. They showed different effects of climate change in different countries. A simulation of the Southeast Asian region indicated that a doubling of CO2 increases yield, whereas an increase in temperature decreases yield.Enhanced UV-B radiation resulting for stratographic ozone depletion has been demonstrated to significantly reduce plant height, leaf area and dry weight of two rice cultivars under glasshouse conditions. Data are still insufficient, however, for conclusive results on the effect of UV-B radiation on rice growth under field conditions.Rice production itself has a significant effect on global warming and atmospheric chemistry through methane emission from flooded ricefields. Water regime, soil properties and the rice plant are major factors controlling the flux of methane in ricefields. Global and regional estimates of methane emission rates are still highly uncertain and tentative. Integration of mechanistic modeling of methane fluxes with geographic information systems of factors controlling these processes are required to improve estimates and predictions.  相似文献   
89.
90.
Zusammenfassung Oft wird zwischen Klüften und Verschiebungen ein genetischer Zusammenhang gesehen. Neuere Untersuchungen lassen einen grundsätzlichen Unterschied erkennen: Die gemeinen Klüfte entstehen durch spröden Bruch im Anschluß an eine elastische Deformation; Verschiebungen und ihnen zugeordnete Klüfte gehen zumeist aus einer plastischen Deformation hervor. Auch sind Verschiebungen an begrenzte Zonen gebunden und meist gefügefremd, obwohl sie sich bestehenden Kluftsystemen anpassen können. Die Systeme der gemeinen Klüfte sind dagegen fast gleichmäßig auf weite Bereiche verteilt und passen sich dem bestehenden Gesteinsgefüge an. Zur Deutung der Bruchtektonik sollten deshalb klufttektonische Analysen nur mit äußerster Vorsicht herangezogen werden.
Joints and faults are commonly regarded as genetically related. Recent investigations, however, tend to bring out a fundamental genetic distinction: Common joints form by brittle fracture following elastic deformation; faults result from ductile fracture. Moreover, faults and related joints are restricted to narrow zones and rarely conform with preexisting fabric, while common joints are regionally pervasive and are fabric controlled. When evaluating fracture analyses, therefore, the genetic distinction between common joints and faults must be borne in mind.

Résumé On croit souvent devoir mettre en relation génétique joints et failles. Des études récentes permettent d'y voir une distinction. Les joints banaux proviennent d'une rupture cassante, à la suite d'une déformation élastique. Les failles suivent une rupture plastique. En plus, les failles et les joints qui leur sont apparentés sont restreints à des zones plus ou moins étroites et se conforment rarement à la structure interne de la roche, trandis que les joints banaux ont une distribution régionale, et sont liés à la structure interne. L'analyse des ruptures géologiques doit, par conséquent, tenir compte d'une distinction fondamentale entre joints banaux, et joints apparentés aux failles.

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