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Regional Analysis (regional + analysis)

Distribution by Scientific Domains

Life Sciences	35%
Humanities and Social Sciences	28%
Medical Sciences	14%

Selected Abstracts

Lottery Expenditures in Canada: Regional Analysis of Probability of Purchase, Amount of Purchase, and Incidence

FAMILY & CONSUMER SCIENCES RESEARCH JOURNAL, Issue 1 2001
Mohamed Abdel-Ghany
This article has two purposes: First, to examine the effect of household characteristics on lottery expenditures in six regions of Canada using a double hurdle model to distinguish between the decision to play and the decision of how much to spend. Second, to estimate the incidence of lottery expenditures. Using the 1996 Canadian Family Expenditure Survey, the results portray the profile of households that have the probability of becoming participants in lottery play as well as the profile of households that spend more on lottery purchases. Lottery expenditures are found to be regressive in all regions. [source]

Regional Analysis of the Ependyma of the Third Ventricle of Rat by Light and Electron Microscopy

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2008
T. C. Mathew
Summary Ependymal lining of cerebral ventricles lies at the interface between the ventricular cavities and the brain parenchyma. Ependymal cells are involved in various functions within the brain and play a major role in the production of the chemical principals of the cerebrospinal fluid. Histological studies on the regional variation of the third ventricular ependyma and the subependyma of adult rats were carried out by light and electron microscopic methods. For light microscopic analysis, methacrylate sections were used. In addition to the routine haematoxylin and eosin (H and E) staining for histological studies, the sections were stained with toluidine blue, cresyl violet and periodic acid Schiff's reagent (PAS). A regional analysis of the ependyma of the third ventricle showed that in most regions the ependyma was monolayered. The sidewalls and floor of the ventral portion of the third ventricle showed a multilayered ependyma. For descriptive purposes at the light microscopic level, the ependymal cells were classified, based on the cell shape (flat, cuboidal or columnar), presence or absence of cilia and the number of cytoplasmic granules present in the cells. Studies of transmission electron microscope have shown that these granules represent the cell organelles of the ependyma. The subependyma also showed a regional morphological variation, and, in most instances, contained glial and neuronal elements. In regions of specific brain nuclei, neurons were the major cell type of the subependyma. PAS staining did not show any positive granules in the ependymal cytosol. Characteristic supraependymal elements were present at the ependymal surface of the third ventricle. [source]

Intellectual abilities and white matter microstructure in development: A diffusion tensor imaging study

HUMAN BRAIN MAPPING, Issue 10 2010
Christian K. Tamnes
Abstract Higher-order cognitive functions are supported by distributed networks of multiple interconnected cortical and subcortical regions. Efficient cognitive processing depends on fast communication between these regions, so the integrity of the connections between them is of great importance. It is known that white matter (WM) development is a slow process, continuing into adulthood. While the significance of cortical maturation for intellectual development is described, less is known about the relationships between cognitive functions and maturation of WM connectivity. In this cross-sectional study, we investigated the associations between intellectual abilities and development of diffusion tensor imaging (DTI) derived measures of WM microstructure in 168 right-handed participants aged 8,30 years. Independently of age and sex, both verbal and performance abilities were positively related to fractional anisotropy (FA) and negatively related to mean diffusivity (MD) and radial diffusivity (RD), predominantly in the left hemisphere. Further, verbal, but not performance abilities, were associated with developmental differences in DTI indices in widespread regions in both hemispheres. Regional analyses showed relations with both FA and RD bilaterally in the anterior thalamic radiation and the cortico-spinal tract and in the right superior longitudinal fasciculus. In these regions, our results suggest that participants with high verbal abilities may show accelerated WM development in late childhood and a subsequent earlier developmental plateau, in contrast to a steadier and prolonged development in participants with average verbal abilities. Longitudinal data are needed to validate these interpretations. The results provide insight into the neurobiological underpinnings of intellectual development. Hum Brain Mapp, 2010. © 2010 Wiley-Liss, Inc. [source]

Regional analysis of bedrock stream long profiles: evaluation of Hack's SL form, and formulation and assessment of an alternative (the DS form)

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 5 2007
Geoff Goldrick
Abstract The equilibrium form of the fluvial long profile has been used to elucidate a wide range of aspects of landscape history including tectonic activity in tectonic collision zones, and in continental margin and other intraplate settings, as well as other base-level changes such as due to sealevel fluctuations. The Hack SL form of the long profile, which describes a straight line on a log,normal plot of elevation (normal) versus distance (logarithmic), is the equilibrium long profile form that has been most widely used in such studies; slope,area analysis has also been used in recent years. We show that the SL form is a special case of a more general form of the equilibrium long profile (here called the DS form) that can be derived from the power relationship between stream discharge and downstream distance, and the dependence of stream incision on stream power. The DS form provides a better fit than the SL form to river long profiles in an intraplate setting in southeastern Australia experiencing low rates of denudation and mild surface uplift. We conclude that, if an a priori form of the long profile is to be used for investigations of regional landscape history, the DS form is preferable. In particular, the DS form in principle enables equilibrium steepening due to an increase in channel substrate lithological resistance (parallel shift in the DS plot) to be distinguished from disequilibrium steepening due to long profile rejuvenation (disordered outliers on the DS plot). Slope,area analysis and the slope,distance (DS) approach outlined here are complementary approaches, reflecting the close relationship between downstream distance and downstream catchment area. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Phylogeography of the world's tallest angiosperm, Eucalyptus regnans: evidence for multiple isolated Quaternary refugia

JOURNAL OF BIOGEOGRAPHY, Issue 1 2010
Paul G. Nevill
Abstract Aim, There is a need for more Southern Hemisphere phylogeography studies, particularly in Australia, where, unlike much of Europe and North America, ice sheet cover was not extensive during the Last Glacial Maximum (LGM). This study examines the phylogeography of the south-east Australian montane tree species Eucalyptus regnans. The work aimed to identify any major evolutionary divergences or disjunctions across the species' range and to examine genetic signatures of past range contraction and expansion events. Location, South-eastern mainland Australia and the large island of Tasmania. Methods, We determined the chloroplast DNA haplotypes of 410 E. regnans individuals (41 locations) based on five chloroplast microsatellites. Genetic structure was examined using analysis of molecular variance (AMOVA), and a statistical parsimony tree was constructed showing the number of nucleotide differences between haplotypes. Geographic structure in population genetic diversity was examined with the calculation of diversity parameters for the mainland and Tasmania, and for 10 regions. Regional analysis was conducted to test hypotheses that some areas within the species' current distribution were refugia during the LGM and that other areas have been recolonized by E. regnans since the LGM. Results, Among the 410 E. regnans individuals analysed, 31 haplotypes were identified. The statistical parsimony tree shows that haplotypes divided into two distinct groups corresponding to mainland Australia and Tasmania. The distribution of haplotypes across the range of E. regnans shows strong geographic patterns, with many populations and even certain regions in which a particular haplotype is fixed. Many locations had unique haplotypes, particularly those in East Gippsland in south-eastern mainland Australia, north-eastern Tasmania and south-eastern Tasmania. Higher haplotype diversity was found in putative refugia, and lower haplotype diversity in areas likely to have been recolonized since the LGM. Main conclusions, The data are consistent with the long-term persistence of E. regnans in many regions and the recent recolonization of other regions, such as the Central Highlands of south-eastern mainland Australia. This suggests that, in spite of the narrow ecological tolerances of the species and the harsh environmental conditions during the LGM, E. regnans was able to persist locally or contracted to many near-coastal refugia, maintaining a diverse genetic structure. [source]

Normal cerebral perfusion measurements using arterial spin labeling: Reproducibility, stability, and age and gender effects

MAGNETIC RESONANCE IN MEDICINE, Issue 4 2004
Laura M. Parkes
Abstract Before meaningful conclusions can be drawn from clinical measures of cerebral blood perfusion, the precision of the measurement must be determined and set in the context of inter- and intrasubject sources of variability. This work establishes the reproducibility of perfusion measurements using the noninvasive MRI technique of continuous arterial spin labeling (CASL). Perfusion was measured in 34 healthy normal subjects. Intersubject variability was assessed, and age and gender contributions were estimated. Intersubject variation was found to be large, with up to 100% perfusion difference for subjects of the same age and gender. Repeated measurements in one subject showed that perfusion remains remarkably stable in the short term when compared with intersubject variation and the large capacity for perfusion change in the brain. A significant decrease in the ratio of gray-matter to white-matter perfusion was found with increasing age (0.79% per year (P < 0.0005)). This appears to be due mainly to a reduction in gray-matter perfusion, which was found to decrease by 0.45% per year (P = 0.04). Regional analysis suggested that the gray-matter age-related changes were predominantly localized in the frontal cortex. Whole-brain perfusion was 13% higher (P = 0.02) in females compared to males. Magn Reson Med 51:736,743, 2004. © 2004 Wiley-Liss, Inc. [source]

Checkpoints and pitfalls in the experimental neuropathology of circulatory disturbance

NEUROPATHOLOGY, Issue 1 2003
Toshihiko Kuroiwa
In neural tissue injury many pathological processes are common to different neurological disorders, including cerebral ischemia. Because ischemia has a fundamentally simple impact on neural tissue, good laboratory modeling can help improve the general understanding of the neuropathological processes involved. Summarized here are some basic principles that should be followed to ensure that cerebral ischemia studies are reproducible and informative: (i) selection of an appropriate model of cerebral ischemia in an appropriate species (although rodents are widely used for genomic studies, the use of larger animals, with brain structures macroscopically similar to those of humans, is appropriate for many studies, e.g. of white matter lesions or the pathophysiology of cerebral edema); (ii) correct maintenance of physiological parameters, including body temperature, systemic blood pressure, and blood gas tensions, under appropriate general anesthesia; (iii) selection of an appropriate method of cerebral blood flow (CBF) monitoring (decisions include whether or not the experiment requires real-time monitoring, in vivo measurement, and CBF mapping); (iv) appropriate timing of drug application in therapeutic studies (many drugs that are effective when given immediately after a short period of ischemi are ineffective in clinical trials, probably because of longer periods of ischemia and delayed drug delivery in clinical settings); and (v) multiparametric evaluation of therapeutic effect (with the recent increase in diagnosis of cases of mild stroke, measurement of mortality and infarct size have proven to be insufficient for the evaluation of therapeutic effect). Use of mild ischemia models and batteries of neurological tests for individual neurological functions, such as motor, somatosensory, and visual function, are becoming important in experimental ischemia research. In histological evaluation, assessment of the extent of both selective neuronal loss and the infarct will become mandatory. Regional analysis of each brain structure and coordination of the results with the apparent neurological dysfunction is a promising approach. [source]

On the use of partial probability weighted moments in the analysis of hydrological extremes

HYDROLOGICAL PROCESSES, Issue 10 2007
Ugo Moisello
Abstract The use of partial probability weighted moments (PPWM) for estimating hydrological extremes is compared to that of probability weighted moments (PWM). Firstly, estimates from at-site data are considered. Two Monte Carlo analyses, conducted using continuous and empirical parent distributions (of peak discharge and daily rainfall annual maxima) and applying four different distributions (Gumbel, Fréchet, GEV and generalized Pareto), show that the estimates obtained from PPWMs are better than those obtained from PWMs if the parent distribution is unknown, as happens in practice. Secondly, the use of partial L-moments (obtained from PPWMs) as diagnostic tools is considered. The theoretical partial L-diagrams are compared with the experimental data. Five different distributions (exponential, Pareto, Gumbel, GEV and generalized Pareto) and 297 samples of peak discharge annual maxima are considered. Finally, the use of PPWMs with regional data is investigated. Three different kinds of regional analyses are considered. The first kind is the regression of quantile estimates on basin area. The study is conducted applying the GEV distribution to peak discharge annual maxima. The regressions obtained with PPWMs are slightly better than those obtained with PWMs. The second kind of regional analysis is the parametric one, of which four different models are considered. The congruence between local and regional estimates is examined, using peak discharge annual maxima. The congruence degree is sometimes higher for PPWMs, sometimes for PWMs. The third kind of regional analysis uses the index flood method. The study, conducted applying the GEV distribution to synthetic data from a lognormal joint distribution, shows that better estimates are obtained sometimes from PPWMs, sometimes from PWMs. All the results seem to indicate that using PPWMs can constitute a valid tool, provided that the influence of ouliers, of course higher with censored samples, is kept under control. Copyright © 2007 John Wiley & Sons, Ltd. [source]

A political ecology of violence and territory in West Kalimantan

ASIA PACIFIC VIEWPOINT, Issue 1 2008
Nancy Lee Peluso
Abstract: This paper uses a political ecology perspective to examine relationships between violence and territory in West Kalimantan, focusing on the violent incidents of 1996,1997 and 1967,1968. Besides a regional account, the paper examines some of the ways residents of one village were drawn into and chose to participate in violence. The author concludes that while regional analyses can identify broad patterns, local analyses enable a greater understanding of both variation and the processes by which ethnic categories are constructed through violence. [source]

Regional and local influence of grazing activity on the diversity of a semi-arid dung beetle community

DIVERSITY AND DISTRIBUTIONS, Issue 1 2006
Jorge M. Lobo
ABSTRACT This study analyses the effect of resource availability (i.e. sheep dung) on dung beetle communities in an arid region of Central Spain, both at regional and at local scales. A total of 18 sites within 600 km2 were sampled for the regional analysis and 16 sites within the 30 km2 of an Iberian municipality were sampled for the local analysis. Spatial and environmental characteristics of sampling sites were also compiled at both scales, including measures of grazing activity (livestock density at regional scale, and two counts of rabbit and sheep dung at local scale). At a regional scale, any environmental or spatial variable can help to explain the variation in abundance. However, species richness was related to summer precipitation and composition was related to elevation. At local scale, abundance is not significantly related to any of the environmental variables, but species richness was related to the local amount of sheep dung (27% of variance). The amount of dung in a 2-km buffer around the site accounts for 27,32% of variance in abundance and 60,65% of variance in species richness. The presence of the flock with the highest sheep density explains 53% of abundance variability and 73% of species richness variance. A cluster analysis of localities identified two main groups, one characterized by a lower abundance and species richness that can be considered a nested subsample of the species-rich group. The mean and maximum amount of sheep dung in the sites separated by less than 2 km are the only significant explanatory variables able to discriminate both groups. These results suggest that grazing intensity (and the associated increase in the amount of trophic resources) is a key factor in determining local variation in the diversity and composition of dung beetle assemblages. However, dung beetle assemblages are not spatially independent at the analysed resolution, and the amount of dung in the surroundings seems to be more important for locally collected species than the dung effectively found in the site. Although differences in the availability and quantity of trophic resources among nearby sites could be affecting the population dynamics and dispersion of dung beetles within a locality, sites with larger populations, and greater species numbers would not be able to exercise enough influence as to bring about a complete local faunistic homogenization. [source]

Perspectives on Regional Change: A Review Essay on Handbook of Regional Growth and Development Theories

GROWTH AND CHANGE, Issue 1 2010
DEAN M. HANINK
Handbook of Regional Growth and Development Theories, edited by Roberta Capello and Peter Nijkamp, Cheltenham, UK and Northampton MA, USA: Edward Elgar, 2009 (xi and 529 pp., £135, $250). ABSTRACT This paper reviews the contributions in The Handbook of Regional Growth and Development Theories, edited by Roberta Capello and Peter Nijkamp. The book's coverage is comprehensive in a conventional way. It emphasizes the significance of recent developments in theoretical and empirical regional analysis that have occurred in both neoclassical (convergence) and new economic geography (concentration) contexts. The role of knowledge spillovers in regional growth receives special attention. Given the recent advances in the field, and renewed interest in regional issues, it is time to expand the focus of analysis from relatively narrow production and distribution concerns, to broader ones that incorporate the effects of structural/sectoral, demographic, and environmental change on the future prospects of regional economies. Such an expansion would not only contribute to the theoretical richness of regional growth and development analysis, it would also do much to expand its utility in guiding public policy. [source]

On the use of partial probability weighted moments in the analysis of hydrological extremes

Dendritic network structure constrains metacommunity properties in riverine ecosystems

JOURNAL OF ANIMAL ECOLOGY, Issue 3 2010
B. L. Brown
Summary 1.,Increasingly, ecologists conceptualize local communities as connected to a regional species pool rather than as isolated entities. By this paradigm, community structure is determined through the relative strengths of dispersal-driven regional effects and local environmental factors. However, despite explicit incorporation of dispersal, metacommunity models and frameworks often fail to capture the realities of natural systems by not accounting for the configuration of space within which organisms disperse. This shortcoming may be of particular consequence in riverine networks which consist of linearly -arranged, hierarchical, branching habitat elements. Our goal was to understand how constraints of network connectivity in riverine systems change the relative importance of local vs. regional factors in structuring communities. 2.,We hypothesized that communities in more isolated headwaters of riverine networks would be structured by local forces, while mainstem sections would be structured by both local and regional processes. We examined these hypotheses using a spatially explicit regional analysis of riverine macroinvertebrate communities, focusing on change in community similarity with distance between local communities [i.e., distance-decay relationships; (DDRs)], and the change in environmental similarity with distance. Strong DDRs frequently indicate dispersal-driven dynamics. 3.,There was no evidence of a DDR in headwater communities, supporting our hypothesis that dispersal is a weak structuring force. Furthermore, a positive relationship between community similarity and environmental similarity supported dynamics driven by local environmental factors (i.e., species sorting). In mainstem habitats, significant DDRs and community × environment similarity relationships suggested both dispersal-driven and environmental constraints on local community structure (i.e., mass effects). 4.,We used species traits to compare communities characterized by low vs. high dispersal taxa. In headwaters, neither strength nor mode (in-network vs. out of network) of dispersal changed our results. However, outcomes in mainstems changed substantially with both dispersal mode and strength, further supporting the hypothesis that regional forces drive community dynamics in mainstems. 5.,Our findings demonstrate that the balance of local and regional effects changes depending on location within riverine network with local (environmental) factors dictating community structure in headwaters, and regional (dispersal driven) forces dominating in mainstems. [source]