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Area Analysis (area + analysis)
Selected AbstractsThe Circumpolar Arctic vegetation mapJOURNAL OF VEGETATION SCIENCE, Issue 3 2005Donald A. Walker Abstract. Question: What are the major vegetation units in the Arctic, what is their composition, and how are they distributed among major bioclimate subzones and countries? Location: The Arctic tundra region, north of the tree line. Methods: A photo-interpretive approach was used to delineate the vegetation onto an Advanced Very High Resolution Radiometer (AVHRR) base image. Mapping experts within nine Arctic regions prepared draft maps using geographic information technology (ArcInfo) of their portion of the Arctic, and these were later synthesized to make the final map. Area analysis of the map was done according to bioclimate subzones, and country. The integrated mapping procedures resulted in other maps of vegetation, topography, soils, landscapes, lake cover, substrate pH, and above-ground biomass. Results: The final map was published at 1:7 500 000 scale map. Within the Arctic (total area = 7.11 × 106 km2), about 5.05 × 106 km2 is vegetated. The remainder is ice covered. The map legend generally portrays the zonal vegetation within each map polygon. About 26% of the vegetated area is erect shrublands, 18% peaty graminoid tundras, 13% mountain complexes, 12% barrens, 11% mineral graminoid tundras, 11% prostrate-shrub tundras, and 7% wetlands. Canada has by far the most terrain in the High Arctic mostly associated with abundant barren types and prostrate dwarf-shrub tundra, whereas Russia has the largest area in the Low Arctic, predominantly low-shrub tundra. Conclusions: The CAVM is the first vegetation map of an entire global biome at a comparable resolution. The consistent treatment of the vegetation across the circumpolar Arctic, abundant ancillary material, and digital database should promote the application to numerous land-use, and climate-change applications and will make updating the map relatively easy. [source] Species,area relationships of red-listed species in old boreal forests: a large-scale data analysisDIVERSITY AND DISTRIBUTIONS, Issue 5 2009Olli-Pekka Tikkanen Abstract Aim, Species,area relationships are often applied, but not generally approved, to guide practical conservation planning. The specific species group analysed may affect their applicability. We asked if species,area curves constructed from extensive databases of various sectors of natural resource administration can provide insights into large-scale conservation of boreal forest biodiversity if the analyses are restricted only to red-listed species. Location, Finland, northern Europe. Methods, Our data included 12,645 records of 219 red-listed Coleoptera and Fungi from the whole of Finland. The forest data also covered the entire country, 202,761 km2. The units of species,area analyses were 224 municipalities where the red-listed forest species have been observed. We performed a hierarchical partitioning analysis to reveal the relative importance of different potential explanatory variables. Based on the results, for all red-listed species, species associated with coniferous trees and for Fungi, the area of economically over-aged forests explained the best the variation in data. For species associated with deciduous trees and Coleoptera, the forest area explained better variation in data than the area of old forests. In the subsequent log,log species,area regression analyses, we used the best variables as the explanatory variable for each species group. Results, There was a strong relationship between the number of all red-listed species and the area of old forests remaining, with a z -value of 0.45. The area explained better the number of species associated with conifer trees and Fungi than the number of species associated with deciduous trees and Coleoptera. Main conclusions, The high z -values of species,area curves indicate that the remaining old-growth patches constitute a real archipelago for the conifer-associated red-listed species, since lower values had been expected if the surrounding habitat matrix were a suitable habitat for the species analysed. [source] Establishing a perimeter position: speciation around the Indian Ocean BasinJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2008G. VOELKER Abstract Historical biological interactions among peripheral landmasses on the periphery of the Indian Ocean Basin (IOB) are generally poorly understood. While interactions based on early Gondwanan vicariance have been used to explain present day lineage distributions, several recent studies have instead inferred dispersal across the IOB. This inference is often advanced because lineages under study have species inhabiting IOB islands. Here we examine the roles of continental vicariance vs. trans-IOB dispersal in the distribution of an avian genus found around the perimeter of the IOB. A molecular phylogeny does reveal evidence of a relationship that would require the inference of trans-IOB dispersal between eastern Africa and Sri Lanka. However, molecular clock data, ancestral area analyses and paleoclimatic reconstructions suggest that vicariance related to tropical forest expansion and retraction is more likely to have facilitated African,Asian interchange, with an initial colonization of Africa from Asia quickly followed by a recolonization of Asia. Subsequent dispersal from Asia to Sri Lanka and islands east of the Sunda Shelf are inferred; these latter islands were colonized in a stepping-stone fashion that culminated in colonization of the Sunda Shelf, and a recolonization of mainland Asia. We propose that circum-IOB distributions, which post-date early Gondwanan breakup, are most likely the result of continent-based vicariant events, particularly those events related to large-scale habitat alterations, and not trans-IOB dispersals. [source] CONGESTIVE CARDIAC FAILURE: URBAN AND RURAL PERSPECTIVES IN VICTORIAAUSTRALIAN JOURNAL OF RURAL HEALTH, Issue 6 2003Mohammad Z. Ansari ABSTRACT Objective:,Effective and timely care for congestive cardiac failure (CCF) should reduce the risks of hospitalisation. The purpose of this study is to describe variations in rates of hospital admissions for CCF in Victoria as an indicator of the adequacy of primary care services. Detailed analyses identify trends in hospitalisations, urban/rural differentials and variations by the Primary Care Partnerships (PCP). Setting:,Acute care hospitals in Victoria. Design:,Routine analyses of age and sex standardised admission rates of CCF in Victoria using the Victorian Admitted Episodes Dataset from 1993,1994 to 2000,2001. Subjects:,All patients admitted to acute care hospitals in Victoria with the principal diagnosis of CCF between 1993,1994 and 2000,2001. Results:,There were 8359 admissions for CCF in Victoria with an average of 7.37 bed days in 2000,2001. There was a significantly higher admission rate for CCF in rural areas compared to metropolitan in 2000/2001 ,(2.53/1000 (2.44,2.62) and 1.80/1000 (1.75,1.85)) , respectively. Small area analyses identified 17 PCP (14 of which were rural) with significantly higher admission rate ratios of CCF compared to Victoria. Conclusion:,Small area analyses of CCF have identified significant gaps in the management of CCF in the community. This may be a reflection of deficit in primary care availability, accessibility, or appropriateness. Detailed studies may be needed to determine the relative importance of these factors in Victoria for targeting specific interventions at the PCP level. What does this study add?:,Congestive cardiac failure is a major public health problem. In Australia, there is a lack of studies identifying long-term hospitalisation trends of CCF, as well as small area analyses, especially in regard to rural and urban variations. This study has identified significant variations over an eight year period in admission rates of CCF in rural and urban Victoria. Small area analyses (e.g. at the level of primary care partnerships) have identified rural communities with significantly higher admission rates of CCF compared to the Victorian average. For the first time in Australia, this study has provided a new approach for generating evidence on quality of primary care services in rural and urban areas, and offers opportunities for targeting public health and health services interventions that can decrease access barriers, improve the adequacy of primary care, and reduce demand on the hospital system in Victoria. [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 2007Geoff 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] Changes in per capita alcohol sales during the partial privatization of British Columbia's retail alcohol monopoly 2003,2008: a multi-level local area analysisADDICTION, Issue 11 2009Tim Stockwell ABSTRACT Aim To investigate the independent effects on liquor sales of an increase in (a) the density of liquor outlets and (b) the proportion of liquor stores in private rather than government ownership in British Columbia between 2003/4 and 2007/8. Design The British Columbia Liquor Distribution Branch provided data on litres of ethanol sold through different types of outlets in 89 local health areas of the province by beverage type. Multi-level regression models were used to examine the relationship between per capita alcohol sales and outlet densities for different types of liquor outlet after adjusting for potential confounding social, economic and demographic factors as well as spatial and temporal autocorrelation. Setting Liquor outlets in 89 local health areas of British Columbia, Canada. Findings The number of private stores per 10 000 residents was associated significantly and positively with per capita sales of ethanol in beer, coolers, spirits and wine, while the reverse held for government liquor stores. Significant positive effects were also identified for the number of bars and restaurants per head of population. The percentage of liquor stores in private versus government ownership was also associated significantly with per capita alcohol sales when controlling for density of liquor stores and of on-premise outlets (P < 0.01). Conclusion The trend towards privatisation of liquor outlets between 2003/04 and 2007/08 in British Columbia has contributed to increased per capita sales of alcohol and hence possibly also to increased alcohol-related harm. [source] Biogeography of the Limacoidea sensu lato (Gastropoda: Stylommatophora): vicariance events and long-distance dispersalJOURNAL OF BIOGEOGRAPHY, Issue 2 2000B. Hausdorf Abstract Aim Reconstruction of the historical biogeography of the Limacoidea sensu lato (including the Staffordiidae, Dyakiidae, Gastrodontoidea, Parmacelloidea, Zonitidae, Helicarionoidea and Limacoidea). Evaluation of the relative importance of dispersal and its consequences. Location World-wide. Methods Weighted ancestral area analysis. Results The ancestral areas of the individual clades have been delimited using weighted ancestral area analysis and a sequence of possible vicariance and dispersal events has been suggested. The results of the ancestral area analysis have tentatively been correlated with Cretaceous and Tertiary palaeogeography. The widely overlapping distribution patterns of several families of the Limacoidea testify to extensive dispersal events. Dispersal capacity of land snails is correlated with body size. The significant negative correlation between body size and distribution area size corroborates the importance of passive dispersal for the evolution of the distribution patterns. Main conclusions The existence of extensive dispersal events of poor active dispersers like land snails diminishes the importance of recent distribution patterns for the reconstruction of palaeogeography. On the other hand, dispersal ensures that biogeographical data reflect the geographical configurations at a given time and renders the use of palaeobiogeographic data for the reconstruction of palaeogeographic configurations of the respective age possible. [source] Genetic analysis of offspring from intra- and interspecific crosses of Carassius auratus gibelio by chromosome and RAPD analysisJOURNAL OF FISH BIOLOGY, Issue 3 2005B. Tóth The ploidy of silver crucian carp Carassius auratus gibelio individuals, originating from nine natural habitats of Hungary, was estimated by erythrocyte nucleus area analysis. On the basis of DNA polymorphism, the genetic homogeneity or heterogeneity and the chromosome number of different offspring derived from the crossing of triploid and diploid populations and of two types of silver crucian carp females with other cyprinid males (Cyprinus carpio, Carassius carassius, Carassius auratus and Barbus conchonius) were determined. The results of chromosome and RAPD analysis demonstrated that diploid females could reproduce sexually with silver crucian carp and other cyprinid males and that the offspring of intra- and interspecific crosses contained the paternal DNA. Triploid females usually reproduced by gynogenesis and their offspring were clones, however, in very rare cases paternal genes were actually transmitted (i.e. paternal leakage) to the offspring and the progeny were triploid interspecific hybrids. RAPD analysis showed that while the paternal DNA appeared in the offspring, the maternal phenotype was strongly expressed. [source] HYDROCARBON SEEPAGE AND CARBONATE MOUND FORMATION: A BASIN MODELLING STUDY FROM THE PORCUPINE BASIN (OFFSHORE IRELAND)JOURNAL OF PETROLEUM GEOLOGY, Issue 2 2005J. Naeth This study assesses whether the growth of deep water carbonate mounds on the continental slope of the north Atlantic may be associated with active hydrocarbon leakage. The carbonate mounds studied occur in two distinct areas of the Porcupine Basin, 200 km offshore Ireland, known as the Hovland-Magellan and the Belgica areas. To evaluate the possible link between hydrocarbon leakage and mound growth, we used two dimensional cross-section and map-based basin modelling. Geological information was derived from interpretation of five seismic lines across the province as well as the Connemara oilfield. Calibration data was available from the northern part of the study area and included vitrinite reflectance, temperature and apatite fission track data. Modelling results indicate that the main Jurassic source rocks are mature to overmature for hydrocarbon generation throughout the basin. Hydrocarbon generation and migration started in the Late Cretaceous. Based on our stratigraphic and lithologic model definitions, hydrocarbon migration is modelled to be mainly vertical, with only Aptian and Tertiary deltaic strata directing hydrocarbon flow laterally out of the basin. Gas chimneys observed in the Connemara field were reproduced using flow modelling and are related to leakage at the apices of rotated Jurassic fault blocks. The model predicts significant focussing of gas migration towards the Belgica mounds, where Cretaceous and Tertiary carrier layers pinch out. In the Hovland-Magellan area, no obvious focus of hydrocarbon flow was modelled from the 2D section, but drainage area analysis of Tertiary maps indicates a link between mound position and shallow Tertiary closures which may focus hydrocarbon flow towards the mounds. [source] The Effect of Preparation Procedures on the Morphology of Melanin from the Ink Sac of Sepia officinalisPIGMENT CELL & MELANOMA RESEARCH, Issue 1 2003Yan Liu The structure of melanin extracted from the ink sac of the cuttlefish Sepia officinalis was examined for different methods of isolation and purification of the pigment. Scanning electron microscopy (SEM) images of Sepia eumelanin prepared by different procedures establish that multi-,m-sized aggregates reported by previous workers are generated by their sample preparation, and that the dominant constituents of Sepia melanin are ,150 nm spherical granules. Brunauer-Emmett-Teller (BET) measurements reveal that Sepia eumelanin from Sigma (prepared by spray drying the pigment) has a surface area of 14.3 m2/g. Pigment extracted directly from the fresh ink sac and then freeze-dried has a surface area of 21.5 m2/g, while CO2 -supercritically dried has a surface area of 37.5 m2/g. This is consistent with SEM images showing that the process of freeze-drying produces aggregates, but to a lesser extent than spray drying. Supercritical drying of the sample produces suspensions of the individual ,150 nm granule, which is more reflective of the natural pigment. Brunauer-Emmett-Teller surface area analysis and Barrett-Joyner-Halenda (BJH) pore volume analysis indicate that the surface of the granules is not smooth and the interior of the granules is not porous, but rather the aggregates of granules are porous. Ultra-high resolution SEM and atomic force microscopy (AFM) images show the granules are easily deformed and are comprised of smaller constituents. De-aggregation of the granules by sonication and ultra-filtration reveal a range of structures depending on the pore size of the membrane used. The implications of these results on quantifying photochemical properties and kinetic reaction rate constants of melanin are discussed. [source] Home range and movements of male feral cats (Felis catus) in a semiarid woodland environment in central AustraliaAUSTRAL ECOLOGY, Issue 1 2001G. P. EDWARDS Abstract There is a paucity of data on the movement patterns of feral cats in Australia. Such data can be used to refine control strategies and improve track-based methods of monitoring populations of feral cats. In this study the home ranges and movements of male feral cats were examined over 3.5 years in a semiarid woodland environment in central Australia. Two home range estimators were used in the examination: (i) minimum convex polygon (MCP); and (ii) fixed kernel. The most widely used method of estimating home range in feral cats is MCP, while the fixed kernel method can be used to identify core areas within a home range. On the basis of the MCP method, the long-term home ranges of feral cats in central Australia were much larger than those recorded elsewhere (mean, 2210.5 ha). Twenty-four hour home ranges were much smaller (mean, 249.7 ha) and feral cats periodically shifted their 24 h ranges within the bounds of their long-term home ranges. Core area analysis indicated marked heterogeneity of space use by male feral cats. Several instances where feral cats moved large distances (up to 34 km) were recorded. These long distance movements may have been caused by nutritional stress. Using data from the literature, it is shown that prey availability is a primary determinant of long-term home range size in feral cats. The relevance of the results to the design of management strategies for feral cats in central Australia is also discussed. [source] Home range and movements of male feral cats (Felis catus) in a semiarid woodland environment in central AustraliaAUSTRAL ECOLOGY, Issue 1 2001G. P. Edwards Abstract There is a paucity of data on the movement patterns of feral cats in Australia. Such data can be used to refine control strategies and improve track-based methods of monitoring populations of feral cats. In this study the home ranges and movements of male feral cats were examined over 3.5 years in a semiarid woodland environment in central Australia. Two home range estimators were used in the examination: (i) minimum convex polygon (MCP); and (ii) fixed kernel. The most widely used method of estimating home range in feral cats is MCP, while the fixed kernel method can be used to identify core areas within a home range. On the basis of the MCP method, the long-term home ranges of feral cats in central Australia were much larger than those recorded elsewhere (mean, 2210.5 ha). Twenty-four hour home ranges were much smaller (mean, 249.7 ha) and feral cats periodically shifted their 24 h ranges within the bounds of their long-term home ranges. Core area analysis indicated marked heterogeneity of space use by male feral cats. Several instances where feral cats moved large distances (up to 34 km) were recorded. These long distance movements may have been caused by nutritional stress. Using data from the literature, it is shown that prey availability is a primary determinant of long-term home range size in feral cats. The relevance of the results to the design of management strategies for feral cats in central Australia is also discussed. [source] | ||||||||||||||||