Home About us Contact
|
Home About us Contact | ||
|
|
||
Regional Populations (regional + population)
Selected AbstractsPOPULATION AND EMPLOYMENT CHANGES IN REGIONAL AUSTRALIAECONOMIC PAPERS: A JOURNAL OF APPLIED ECONOMICS AND POLICY, Issue 1 2007ANNE M. GARNETT Regional Australia has experienced significant changes in population and employment since the early 1990s. Evidence regarding these changes has often been anecdotal, with references in political and media spheres to a ,Sea Change' or ,Tree Change'. There has also been considerable public discussion about the effect that the structural changes and misfortunes within the agricultural sector have had on localities in rural regions. The purpose of this paper is to provide and analyse data on regional population and employment changes since the early 1990s. It will also examine the role that the agricultural sector may have had in these changes. This will provide a basis for informed debate and analysis of population changes in regional Australia and the causes and implications of these changes. [source] An empirical test of source,sink dynamics induced by huntingJOURNAL OF APPLIED ECOLOGY, Issue 5 2005ANDRÉS J. NOVARO Summary 1Under the source,sink model, persistence of populations in habitat sinks, where deaths outnumber births, depends on dispersal from high-quality habitat sources, where births outnumber deaths. The persistence of the regional population depends on the proportion of sink relative to source habitat. 2Hunting that occurs in some parts of the landscape and not in others can create patches where deaths outnumber births. We tested whether hunting of culpeo foxes Pseudalopex culpaeus, which is patchily distributed in relatively homogeneous habitat in Argentine Patagonia, induces source,sink dynamics. 3On Patagonian sheep ranches, culpeos are hunted for fur and to protect sheep, and on cattle ranches hunting is usually banned. We monitored culpeo densities using scent stations and estimated survival, fecundity and dispersal by radio-tracking 44 culpeos and analysing carcasses collected from hunters on two cattle and four sheep ranches between 1989 and 1997. 4Survival of juvenile culpeos was lower on hunted than unhunted ranches, mainly as a result of hunting mortality. Reproduction could not compensate for high mortality on hunted ranches. Interruption of hunting led to an increase in juvenile survival, indicating that hunting and natural mortality were not compensatory. We concluded that sheep ranches were sinks because of the high mortality and that sink populations may be maintained by dispersal from cattle ranches. 5We used a simulation model to assess implications of changes in the proportion of source and sink areas on population dynamics. The percentage of land on cattle ranches in the study area was 37%. Current hunting pressure on culpeos would not be sustainable if that percentage fell below 30%. 6Synthesis and applications. Source,sink dynamics may occur in landscapes where hunting is intense and spatially heterogeneous. Wildlife management traditionally monitors demographic rates to evaluate the sustainability of hunting, but our results suggest that the size and spatial arrangement of areas with and without hunting should be considered as well. In regions where enforcement and monitoring are limited, securing large and regularly distributed source areas for hunted species may be more effective than trying to regulate harvest size. [source] Climate variability and change over southern Africa: impacts and challengesAFRICAN JOURNAL OF ECOLOGY, Issue 2009Alec Sithole Abstract In this paper, the influence of climate variability and change on the environment was studied over southern Africa using ground-based and remotely sensed data. A time series analysis of rainfall and temperature anomalies indicated that there was a high rainfall and temperature variability in the region. The influence of global teleconnections on rainfall patterns over southern Africa showed that in some areas there was a spatial variation in their strength, increasing from west to east. Maps of NDVI, from 1982 to 2004, showed that changes in vegetation cover were more apparent during the dry season than during the wet season. The study also revealed that climate variability and change are linked to decreasing rainfall and hence, decreasing regional water resources and biodiversity and increasing environmental degradation. With the regional population expected increase, this depletion of resources poses the greatest regional environmental challenge to humankind. [source] A randomised controlled trial to evaluate the effect of self-administered analgesia on women's experience of outpatient treatment at colposcopyBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 12 2005M.E. Cruickshank Objective To evaluate the effect of self-administered isoflurane and desflurane on women's experience of outpatient treatment at colposcopy. Design A prospective double-blinded randomised controlled trial. Setting A colposcopy clinic serving a regional population. Population Three hundred and ninety-six women scheduled for treatment of cervical intraepithelial neoplasia (CIN) by large loop excision of the transformation zone (LLETZ). Methods Self-administration of trial gas during a LLETZ procedure. One hundred and ninety-eight women were randomised to use isoflurane and desflurane and 198 to use placebo. Main outcome measures Patient satisfaction, pain and anxiety. Results The mean pain score for cervical surgery was significantly lower for women using isoflurane and desflurane (22.4) than the placebo arm (29.6) (P= 0.003). There was no significant difference between arms in anxiety levels before or after treatment. More women using isoflurane and desflurane (78%) reported ,total helpfulness' of the trial gas than those using placebo (67%) (P= 0.012). A subgroup analysis of trial participants classified as anxious by Hospital Anxiety and Depression Scale (HADS) score at recruitment showed that using isoflurane and desflurane significantly increased total treatment acceptability, helpfulness of the gas and willingness to undergo a similar procedure at six-month follow up. Conclusion Satisfaction with outpatient treatment at colposcopy is generally high. The main effect of isoflurane and desflurane evaluated in this trial was to reduce pain. It appeared to be effective for women with clinically significant anxiety and could be offered as an alternative to general anaesthesia. [source] Effects of agricultural diversification on the abundance, distribution, and pest control potential of spiders: a reviewENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2000Keith Sunderland Abstract A review of the literature showed that spider abundance was increased by diversification in 63% of studies. A comparison of diversification modes showed that spider abundance in the crop was increased in 33% of studies by ,aggregated diversification' (e.g. intercropping and non-crop strips) and in 80% of studies by ,interspersed diversification' (e.g., undersowing, partial weediness, mulching and reduced tillage). It is suggested that spiders tend to remain in diversified patches and that extending the diversification throughout the whole crop (as in interspersed diversification) offers the best prospects for improving pest control. There is little evidence that spiders walk in significant numbers into fields from uncultivated field edges, but diversification at the landscape level serves to foster large multi-species regional populations of spiders which are valuable as a source of aerial immigrants into newly planted crops. There are very few manipulative field studies where the impact of spiders on pests has been measured in diversified crops compared with undiversified controls. It is encouraging, however, that in those few studies an increased spider density resulted in improved pest control. Future work needs are identified. [source] Using SimBritain to Model the Geographical Impact of National Government PoliciesGEOGRAPHICAL ANALYSIS, Issue 1 2007Dimitris Ballas In this article, we use a dynamic spatial microsimulation model of Britain for the analysis of the geographical impact of policies that have been implemented in Britain in the last 10 years. In particular, we show how spatial microsimulation can be used to estimate the geographical and socio-economic impact of the following policy developments: introduction of the minimum wage, winter fuel payments, working families tax credits, and new child and working credits. This analysis is carried out with the use of the SimBritain model, which is a product of a 3-year research project aimed at dynamically simulating urban and regional populations in Britain. SimBritain projections are based on a method that uses small area data from past Censuses of the British population in order to estimate small-area data for 2001, 2011, and 2021. [source] Inter-ocean dispersal is an important mechanism in the zoogeography of hakes (Pisces: Merluccius spp.)JOURNAL OF BIOGEOGRAPHY, Issue 6 2001W. Stewart Grant Aim To present new genetic data and to review available published genetic data that bear on the phylogeny of hakes in the genus Merluccius. To construct a zoogeographical model from a summary phylogenetic tree with dated nodes. To search for an explanation of antitropical distributions in hakes. To assess peripheral isolate, centrifugal and vicariance models of speciation in view of the molecular phylogeny and zoogeography of hakes. Locations Northern and southern Atlantic Ocean, eastern Pacific Ocean, South Pacific Ocean. Methods Electrophoretic analysis of 20 allozyme loci in 10 species of hakes. Phylogenetic tree construction with parsimony and bootstrap methods. Reanalysis of previous genetic data. Analysis of zoogeographical patterns with geographical distributions of molecular genetic markers. Results Phylogenetic analyses of new and previous allozyme data and previous mitochondrial DNA data indicate a deep genetic partition between Old- and New-World hakes with genetic distances corresponding to 10,15 Myr of separation. This time marks a widening rift between Europe and North America and a rapid drop in ocean temperatures that subdivided an ancestral population of North Atlantic hake. Two Old-World clades spanning the equator include pairs of sister taxa separated by tropical waters. Divergence times between these pairs of sister-taxa variously date to the early Pliocene and late Pleistocene. Amongst New-World hakes, pairs of sister taxa are separated by equatorial waters, by the Southern Ocean, and by the Panama Isthmus. These genetic separations reflect isolation by the rise of the Isthmus 3,4 Ma and by Pliocene and Pleistocene dispersals. Pairs of species occurring in sympatry or parapatry in six regions do not reflect sister-species relationships, but appear to reflect allopatric divergence and back dispersals of descendent species. Some geographically isolated regional populations originating within the last few hundreds of thousands of years merit subspecies designations. Conclusions Vicariance from tectonic movement of continental plates or ridge formation cannot account for the disjunct distributions of most hake sister taxa. Molecular genetic divergences place the origin of most hake species diversity in the last 2,3 Myr, a period of negligible tectonic activity. Distributions of many hake species appear to have resulted from dispersals and back dispersals across both warm equatorial waters and cool waters in the Southern Ocean, driven by oscillations in climate and ocean temperatures. Genetic and ecological divergence prevents hybridization and competitive exclusion between sympatric species pairs in six regions. Sister-taxa relationships and estimates of divergence are consistent with the modified peripheral isolate model of speciation in which vicariances, range expansions and contractions, dispersals and founder events lead to isolated populations that subsequently diverge to form new species. [source] Virulence Frequences of Puccinia triticina in Germany and the European Regions of the Russian FederationJOURNAL OF PHYTOPATHOLOGY, Issue 1 2007V. Lind Abstract From 2001 to 2003, leaf rust was collected in different regions of Germany and the Russian Federation to generate single spore isolates and to study the structure of the pathogen populations by analyses of virulence. The virulence of isolates was tested with 38 near-isogenic lines each carrying a different resistance gene. The analyses of variance revealed significant effects for the frequency of virulent isolates, the regions and most interactions with years and regions, but no significance was found for the effects of years. In Germany, an increase of virulence frequencies was detected for Lr1 and Lr2a while a decrease was found for Lr3a, Lr3bg and Lr3ka. Such clear trends did not occur in Russia which may be due to the great agroclimatic differences between regions. The variance of the frequency of virulent isolates was used to estimate adequate sample sizes for the analysis of regional populations of leaf rust. This procedure resulted in more reliable information about the dynamic processes within the pathogen populations. In 2002 and 2003, all pathotypes in Germany had a combined virulence to Lr1, Lr2a, Lr2b, Lr15, Lr17 and Lr20 supplemented by a few other genes. The complexity of virulence was lower in the most frequent pathotypes. In Russia virulence to the alleles at locus Lr3 was very common. Using detached leaf segments in Germany and Russia it turned out that the most virulent pathotypes carry 34 and 32 virulence genes, respectively. Virulence to Lr9, Lr19, Lr24 and Lr38 was rare or even absent. The use of major genes, not overcome by corresponding virulent pathotypes, may contribute to more durable types of resistance in case they are combined with genes having different effects, e.g. adult plant resistance. [source] Spatial aggregation in Fusarium pseudograminearum populations from the Australian grain beltPLANT PATHOLOGY, Issue 1 2009A. R. Bentley Previous studies have evaluated the overall structure of populations of Fusarium pseudograminearum (teleomorph, Gibberella coronicola), causal agent of cereal crown rot, but there is no information available on spatial relationships of genetic variation in field populations. Three 1-m-row sections in crown-rot-affected wheat fields in the Australian grain belt were intensively sampled to estimate population genetic parameters and the spatial aggregation, or clustering, of disease aggregates and genotypes. Estimates of population genetic parameters based on amplified fragment length polymorphisms (AFLPs) indicated that the genetic diversity in isolates from the 1-m-row populations described a significant portion of the diversity recorded for corresponding field and regional populations. In point pattern analysis, there was physical clustering and aggregation of F. pseudograminearum isolates from two of the three sites. Analysis of the spatial distribution of clonal haplotypes (DICE similarity , 97%) indicated significant aggregation of clones in all three 1-m-row populations. Based on matrix comparison tests, both mating types and genetic distances had significant spatial aggregation for at least two of the three 1-m-row populations. This is consistent with the presence of non-random spatial genetic structure due to clonal aggregation. High levels of genetic diversity and spatial structuring of disease and genotypes in at least two of the three 1-m-row populations is consistent with the hypothesis that stubble is a primary inoculum source in no-tillage farming systems, resulting in aggregated patterns of disease and allowing for haplotypes to be maintained in the field over a number of annual cropping cycles. [source] Genetic heterogeneity in regional populations of Quebec,Parental lineages in the Gaspe PeninsulaAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Claudia Moreau Abstract Stable colonization of the Gaspe Peninsula by Europeans started in the middle of the 18th century at the time of the British conquest of New France. The earliest settlers were Acadians, escaping British deportation policies, followed by Loyalists from the US, who preferred to remain under British rule after the Declaration of Independence. In the 19th century, the developing fishing industry attracted French Canadians from the St. Lawrence Valley and newcomers from Europe including Channel Islanders from Jersey and Guernsey. We analyzed parental lineages of the self-declared descendants of these four groups of settlers by mtDNA D-loop sequencing and Y-chromosome genotyping and compared them with French, British, and Irish samples. Their representation in terms of haplotype frequency classes reveals different signatures of founder effects, such as a loss of rare haplotypes, modification of intermediate frequency haplotypes, reduction in genetic diversity (seen in Acadians), but also enrichment by admixture. Parental lineages correlate with group identity. Descendants of early settlers, Acadians and Loyalists, preserved their identity more than those of French Canadian and Channel Islander "latecomers." Although overall genetic diversity among Gaspesians is comparable with their European source populations, FST analysis indicated their greater differentiation. Distinct settlement history, a limited number of founders and relative genetic isolation contributed to the regionalization of the Quebec gene pool that appears less homogenous than usually anticipated. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Genetic Diversity of Populations of Monilinia fructicola (Fungi, Ascomycota, Helotiales) from ChinaTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2010JIN-YAN FAN ABSTRACT. The genetic variation among 128 isolates of Monilinia fructicola (Fungi, Ascomycota, Helotiales) from China was analyzed using Inter-Simple Sequence Repeat (ISSR) markers and compared with those of samples from California, USA and New Zealand. A total of 72 reproducible DNA fragments were scored, of which 87.5% (63/72) were polymorphic. The Nei's gene diversity and Shannon's diversity indices of three Chinese regional populations were very similar to that from California. However, several differences were observed among geographic populations of M. fructicola from both within China and between China and California. The analysis of molecular variance (AMOVA) of isolates from different geographic locations suggested that most of the observed genetic variation was found within populations. Results of this study are inconsistent with the hypothesis that the Chinese populations of M. fructicola were derived from a single or few recent migrants from other countries. Instead, our results suggest that M. fructicola has been in China long before its first official recording in 2003. [source] | |||||||||||||