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New Regions (new + regions)
Selected AbstractsA COMPARISON OF MEXICAN MIGRANT REMITTANCES ACROSS U.S. REGIONSCONTEMPORARY ECONOMIC POLICY, Issue 3 2008STEPHEN T. FAIRCHILD Since 1990, the United States has experienced a geographic dispersion of Mexican migrants from traditional gateways to new regions. Using data from the Mexican Migration Project, we find significant differences in both the likelihood of remitting and the amount remitted by Mexican migrants across U.S. regions. Specifically, Mexican migrants living in U.S. regions that have experienced considerable increases in migrant populations since 1990 (the Northeast, Southeast, Mountain, and Midwest regions) remit at higher rates and in larger quantities than migrants living in more traditional migrant destinations (the Pacific and South Central regions), even after controlling for observed differences in migrant populations. (JEL F22, F32, J11, R23) [source] Phylogenetic relatedness and plant invader success across two spatial scalesDIVERSITY AND DISTRIBUTIONS, Issue 3 2009Marc W. Cadotte ABSTRACT Aim, Successful invaders often possess similar ecological traits that contribute to success in new regions, and thus under niche conservatism, invader success should be phylogenetically clustered. We asked if the degree to which non-native plant species are phylogenetically related is a predictor of invasion success at two spatial scales. Location, Australia , the whole continent and Royal National Park (south-eastern Australia). Methods, We used non-native plant species occupancy in Royal National Park, as well as estimated continental occupancy of these species from herbarium records. We then estimated phylogenetic relationships using molecular data from three gene sequences available on GenBank (matK, rbcL and ITS1). We tested for phylogenetic signals in occupancy using Blomberg's K. Results, Whereas most non-native plants were relatively scarce, there was a strong phylogenetic signal for continental occupancy, driven by the clustering of successful species in Asteraceae, Caryophyllaceae, Poaceae and Solanaceae. However, we failed to detect a phylogenetic signal at the park scale. Main Conclusions, Our results reveal that at a large spatial scale, invader success is phylogenetically clustered where ecological traits promoting success appear to be shared among close relatives, indicating that phylogenetic relationships can be useful predictors of invasion success at large spatial scales. At a smaller, landscape scale, there was no evidence of phylogenetic clustering of invasion success, and thus, relatedness plays a much reduced role in determining the relative success of invaders. [source] NeuralEnsembles: a neural network based ensemble forecasting program for habitat and bioclimatic suitability analysisECOGRAPHY, Issue 1 2009Jesse R. O'Hanley NeuralEnsembles is an integrated modeling and assessment tool for predicting areas of species habitat/bioclimatic suitability based on presence/absence data. This free, Windows based program, which comes with a friendly graphical user interface, generates predictions using ensembles of artificial neural networks. Models can quickly and easily be produced for multiple species and subsequently be extrapolated either to new regions or under different future climate scenarios. An array of options is provided for optimizing the construction and training of ensemble models. Main outputs of the program include text files of suitability predictions, maps and various statistical measures of model performance and accuracy. [source] Parasites lost , do invaders miss the boat or drown on arrival?ECOLOGY LETTERS, Issue 4 2010Catriona J. MacLeod Ecology Letters (2010) 13: 516,527 Abstract Host species that colonize new regions often lose parasite species. Using population arrival and establishment data for New Zealand's introduced bird species and their ectoparasitic chewing lice species, we test the relative importance of different processes and mechanisms in causing parasite species loss. Few lice failed to arrive in New Zealand with their hosts due to being missed by chance in the sample of hosts from the original population (missing the boat). Rather, most lice were absent because their hosts or the parasite themselves failed to establish populations in their new environment. Given they arrived and their host established, parasite persistence was more strongly related to factors associated with transmission efficiency (number of host individuals introduced, host body size, host sociality and parasite suborder) than parasite propagule pressure and aggregation. Such insights into parasite success are invaluable to both understanding and managing their impact. [source] Body size and invasion success in marine bivalvesECOLOGY LETTERS, Issue 2 2002Kaustuv Roy The role of body size in marine bivalve invasions has been the subject of debate. Roy et al. found that large-bodied species of marine bivalves were more likely to be successful invaders, consistent with patterns seen during Pleistocene climatic change, but Miller et al. argued that such selectivity was largely driven by the inclusion of mariculture species in the analysis and that size-selectivity was absent outside of mariculture introductions. Here we use data on non-mariculture species from the north-eastern Pacific coast and from a global species pool to test the original hypothesis of Roy et al. that range limits of larger bivalves are more fluid than those of smaller species. First, we test the hypothesis that larger bivalve species are more successful than small species in expanding their geographical ranges following introduction into new regions. Second, we compare body sizes of indigenous and non-indigenous species for 299 of the 303 known intertidal and shelf species within the marine bivalve clade that contains the greater number of non-mariculture invaders, the Mytilidae. The results from both tests provide additional support for the view that body size plays an important role in mediating invasion success in marine bivalves, in contrast to Miller et al. Thus range expansions in Recent bivalves are consistent with patterns seen in Pleistocene faunas despite the many differences in the mechanisms. [source] The Expansion of the Finance Industry and Its Impact on the Economy: A Territorial Approach Based on Swiss Pension FundsECONOMIC GEOGRAPHY, Issue 3 2009José Corpataux abstract A new economic geography of finance is emerging, and the current "financialization" of contemporary economies has contributed greatly to the reshaping of the economic landscape. How can these changes be understood and interpreted, especially from a territorial point of view? There are two contradictory economic theories regarding the tangible effects of the rise of the finance industry. According to neoclassical financial theorists, the finance industry's success is based on its positive effects on the real economy through its capacity to allocate financial resources efficiently. An alternative approach, adopted here, posits that finance does not merely mirror the real economy and that the financial economy, far from being a simple instrument for the allocation of capital, has its own autonomy, its own logic of development and expansion. A series of complex, and sometimes contradictory, connections link financial markets and the real economy, and there are some tensions between them, calling into question the coherence of the regional and national economies that follow from them. Moreover, the territorial approach shows how the mobility/liquidity of capital and the changing dimensions of new regions and countries are central to the finance industry's functioning. This article builds an understanding of the financial system through the lens of pension funds and highlights the impact of such a system on the real economy and its geography. [source] The dynamic network subserving the three phases of cognitive procedural learningHUMAN BRAIN MAPPING, Issue 12 2007Valérie Hubert Abstract Cognitive procedural learning is characterized by three phases (cognitive, associative, and autonomous), each involving distinct processes. We performed a behavioral study and a positron emission tomography (PET) activation study using the Tower of Toronto task. The aim of the behavioral study was to determine cognitive predictors for the length of each of the three learning phases, in order to preselect subjects for the PET study. The objective of the second study was to describe the cerebral substrates subtending these three phases. Contrasted with a reference (motor) task, the cognitive phase activated the prefrontal cortex, cerebellum, and parietal regions, all of which became less active as learning progressed. The associative phase was characterized by the activation of the occipital regions, right thalamus, and caudate nucleus. During the autonomous phase, new regions were involved, including the left thalamus and an anterior part of the cerebellum. These results, by employing a direct comparison between phases, provide the first evidence of the involvement and the time course of activation of different regions in each learning phase, in accordance with current models of cognitive procedural learning. The involvement of a frontoparietal network suggests the use of strategies in problem solving during the cognitive phase. The involvement of the occipital regions during the associative and autonomous phase suggests the intervention of mental imagery. Lastly, the activation of the cerebellum during the autonomous phase is consistent with the fact that performance in this phase is determined by psychomotor abilities. Hum Brain Mapp, 2007. © 2007 Wiley-Liss, Inc. [source] Globalized Horticulture: The Formation and Global Integration of Export Grape Production in North East BrazilJOURNAL OF AGRARIAN CHANGE, Issue 4 2010BEN SELWYN In horticulture contemporary globalization is associated with (at least) two connected processes , the concentration, centralization and expanding reach of global retailers and the emergence of numerous new sites of export horticulture specializing in fresh fruit and vegetable production aimed at metropolitan markets. Whilst there have been numerous studies about developmental impacts, conditions of labour, and producers' upgrading strategies within this new context, few studies give much, if any, space to explaining and analyzing the processes through which these new regions have come into being. This article provides a detailed account of the emergence and global integration of one of these new sites , the São Francisco valley grape branch in North East Brazil, within the context of the wider regional fruiticulture sector. It focuses on state activities and incentives, the provenance of grape producers and their organizations, and grape branch composition. [source] East meets west: adaptive evolution of an insect introduced for biological controlJOURNAL OF APPLIED ECOLOGY, Issue 3 2008C. B Phillips Summary 1A possible explanation for low success rates when introducing natural enemies to new regions for biological control of insect pests is that they fail to adapt to their new conditions. Therefore it has been widely recommended that biological control practitioners increase the probability of local adaptation by maximizing the genetic variation released. An alternative recommendation is to use climate matching to identify native populations that may already possess traits suited to the new region. However, support for these recommendations is weak through lack of empirical evidence that local adaptation is important to biological control. 2This study examined how genetic drift and selection influenced the population frequencies of two asexually reproducing, genetically differentiated parasitoid biotypes that were introduced to New Zealand from South America for biological control. Other than by mutation, the biotypes were genetically fixed due to the absence of recombination both within and between biotypes. This meant that adaptive evolution could occur only if selection acted on any traits that varied between the biotypes introduced from South America. 3The two parasitoid biotypes were released simultaneously at 14 sites and their frequencies were monitored for up to 10 years. Changes in biotype frequency were consistent with strong directional selection favouring one of the South American biotypes, thus generating established parasitoid populations that were better adapted to New Zealand conditions than those that had originally been released. This local adaptation of the control agent contributed to greater mortality of the pest. 4Synthesis and applications. This study provides the first clear demonstration of the importance of releasing natural enemy genetic variation in new regions to foster adaptive evolution and improve success rates in classical biological control. However, the benefit to biological control of maximizing the genetic variation released needs to be balanced against possible risks to non-target species. The results do not support the concept of choosing sampling sites for putative biological control agents based solely on climatic similarities between the source location and the intended region of introduction. [source] The feasibility of developing a risk assessment for the impact of climate change on the emergence of Crimean-Congo haemorrhagic fever in livestock in Europe: a ReviewJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2010P. Gale Summary Crimean-Congo haemorrhagic fever virus (CCHFV) is one of the most widespread of all medically important arboviruses with ticks of the Hyalomma spp. serving as the main vectors. Infection of livestock by CCHFV serves as a route of exposure to humans, as a reservoir of disease and as a route of importation. This study discusses the pathways and data requirements for a qualitative risk assessment for the emergence of CCHFV in livestock in Europe. A risk map approach is proposed based on layers that include the potential routes of release (e.g. by migrating birds carrying infected ticks) together with the main components for exposure, namely the distributions of the tick vectors, the small vertebrate host reservoirs and the livestock. A layer on landscape fragmentation serves as a surrogate for proximity of livestock to the tick cycle. Although the impact of climate change on the emergence of CCHF is not clear, comparing the distribution of risk factors in each layer currently with those predicted in the 2080s with climate change can be used to speculate how potential high-risk areas may shift. According to the risk pathway, transstadial and/or transovarial transmission in the tick vector are crucial for CCHFV spread. Vector competence and tick vector switching, however, remain critical factors for CCHFV colonization of new regions in Europe. The species of migratory bird is also an important consideration in the release assessment with greater abundance and biodiversity of ground-dwelling birds in southern Europe than in northern Europe. [source] Release from foliar and floral fungal pathogen species does not explain the geographic spread of naturalized North American plants in EuropeJOURNAL OF ECOLOGY, Issue 3 2009Mark Van Kleunen Summary 1During the last centuries many alien species have established and spread in new regions, where some of them cause large ecological and economic problems. As one of the main explanations of the spread of alien species, the enemy-release hypothesis is widely accepted and frequently serves as justification for biological control. 2We used a global fungus,plant host distribution data set for 140 North American plant species naturalized in Europe to test whether alien plants are generally released from foliar and floral pathogens, whether they are mainly released from pathogens that are rare in the native range, and whether geographic spread of the North American plant species in Europe is associated with release from fungal pathogens. 3We show that the 140 North American plant species naturalized in Europe were released from 58% of their foliar and floral fungal pathogen species. However, when we also consider fungal pathogens of the native North American host range that in Europe so far have only been reported on other plant species, the estimated release is reduced to 10.3%. Moreover, in Europe North American plants have mainly escaped their rare, pathogens, of which the impact is restricted to few populations. Most importantly and directly opposing the enemy-release hypothesis, geographic spread of the alien plants in Europe was negatively associated with their release from fungal pathogens. 4Synthesis. North American plants may have escaped particular fungal species that control them in their native range, but based on total loads of fungal species, release from foliar and floral fungal pathogens does not explain the geographic spread of North American plant species in Europe. To test whether enemy release is the major driver of plant invasiveness, we urgently require more studies comparing release of invasive and non-invasive alien species from enemies of different guilds, and studies that assess the actual impact of the enemies. [source] Transverse motions in CSOs?ASTRONOMISCHE NACHRICHTEN, Issue 2-3 2009C. Stanghellini Abstract The measurement of proper motions in CSOs is a powerful tool to determine the dynamical evolution of the newly born extragalactic radio sources. We observed 3 CSOs with the VLBA in 2004 and in 2006 to monitor changes in their structure and measure the separation velocity of the hot spots. It is important to increase the size of the samples of CSOs with measured expansion velocity to test the existence of frustrated objects, and put stringent constraints on the current models. We found for all the three objects observed a transverse motion of the hot-spots, and we suggest as the more likely explanation a precession in the jet axis. This behaviour likely inhibits or at least slows down the radio source growth because the head of the hot-spot continuously hits new regions of the ISM. Therefore these radio sources may represent an old population of GPS/CSOs (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Emerging and poorly known viral inflammatory eye diseasesACTA OPHTHALMOLOGICA, Issue 2009M KHAIRALLAH Arthropod vector borne diseases are among the most important emergent infections. They include a wide variety of bacterial, viral, and parasitic diseases that are transmitted to humans by the bite of mosquito, tick, or other arthropod. Most of them are prevalent in tropical and subtropical areas, but they tend to spread into new regions mainly due to increasing temperatures worldwide, movement of people, increasing human population densities, wider dispersal of competent vectors, and transportation of goods and animals. Numerous arthropod vector borne diseases have been associated with uveitis. Among them, specific viral diseases recently emerged as important causes of uveitis in the developing and developed world. They include West Nile virus (WNV) infection, Rift Valley fever (RVF) , dengue fever (DF), and Chikungunya. These viral diseases have been recently associated with an array of ocular manifestations, including anterior uveitis, retinitis, chorioretinitis, retinal vaculitis, and optic nerve involvement. Proper clinical diagnosis of any of these infectious diseases is based on epidemiological data, history, systemic symptoms and signs, and the pattern of uveitis. The diagnosis is usually confirmed by detection of specific antibody in serum. A systematic ocular examination, showing fairly typical findings, can help establish an early clinical diagnosis of a specific systemic viral infection while serologic testing is pending. Prevention remains the mainstay for control of arthropod vector borne viral diseases. [source] | |||||||||||||