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Southern United States (southern + united_states)
Selected AbstractsAggression in imported fire ants: an explanation for shifts in their spatial distributions in Southern United States?ECOLOGICAL ENTOMOLOGY, Issue 4 2009HENRY Y. FADAMIRO Abstract 1.,The imported fire ants, Solenopsis invicta Buren (red), S. richteri Forel (black), and their hybrids (S. invicta × S. richteri) are sympatric congeners with overlapping but shifting spatial distributions in northern Alabama and Mississippi, United States. 2.,The abilities of workers of the three ant forms (or species) to recognise non-nestmate conspecifics and heterospecifics were compared in separate aggression bioassays using three group sizes of competitor numbers (battles): 1-1, 5-1, and 5-5 resident,intruder battles. 3.,Workers of all three forms showed significant aggression toward non-nestmate conspecifics and heterospecifics. The results of the intra-specific aggression bioassays showed that S. invicta had the lowest aggression threshold, whereas S. richteri was the least aggressive. Survival rates 1 day after intra-specific encounters were higher for S. richteri than for S. invicta or hybrids, consistent with its lower aggressiveness. 4.,In inter-specific interactions, S. invicta workers showed the greatest aggression and were more aggressive towards S. richteri than to hybrids. Furthermore, survival 1 day after inter-specific encounters was highest for S. invicta workers, whether they were the intruders or residents. The hybrid form was intermediate between both parental forms in aggression and post-aggression survival. 5.,The live 1-1 and 5-5 battles produced similar and consistent results, but differences were amplified in the 5-5 battles, suggesting an effect of group size on aggression. These results may explain the observed shifts in the spatial distributions of the three forms and range restriction of S. richteri in southern United States. [source] Effects of oleoresins and monoterpenes on in vitro growth of fungi associated with pine decline in the Southern United StatesFOREST PATHOLOGY, Issue 3 2009L. G. Eckhardt Summary As a means of exploring pine resistance to root disease and declines, the effects of host plant secondary metabolites on the growth of root colonizing fungi associated with three diseases/declines of southern pines , loblolly pine decline, littleleaf disease and annosum root rot were tested. The associated fungi ,Leptographium huntii, L. serpens, L. terebrantis, L. procerum, Heterobasidion annosum and Phytophthora cinnamomi, were grown in saturated atmospheres or in direct contact with, pure monoterpenes and crude oleoresin collected from the four southern pines (Pinus taeda, P. eschinata, P. palustris and P. elliotti) for 7 day. Fungal growth was measured at 3, 5 and 7 day. Root-infecting fungi differed significantly in sensitivity to crude oleoresin and pure monoterpenes. All fungi tested were inhibited, to some extent, by the resins tested. H. annosum and P. cinnamomi were strongly inhibited by all the monoterpenes tested. The ophiostomatoid fungi were significantly less affected by the compounds tested. L. huntii and L. serpens were less inhibited by monoterpenes than either L. terebrantis or L. procerum. These fungal growth studies show that the kind and amount of secondary metabolite produced by the host plant have a profound effect on tree pathogens. Alterations of tree physiology may have implications for defenses against tree pathogens as well as to the ecology and management of forest ecosystems. Difference in incidence of root disease observed in the field may be explained by the ability of the fungus to tolerate these host defense mechanisms. [source] Aggression in imported fire ants: an explanation for shifts in their spatial distributions in Southern United States?ECOLOGICAL ENTOMOLOGY, Issue 4 2009HENRY Y. FADAMIRO Abstract 1.,The imported fire ants, Solenopsis invicta Buren (red), S. richteri Forel (black), and their hybrids (S. invicta × S. richteri) are sympatric congeners with overlapping but shifting spatial distributions in northern Alabama and Mississippi, United States. 2.,The abilities of workers of the three ant forms (or species) to recognise non-nestmate conspecifics and heterospecifics were compared in separate aggression bioassays using three group sizes of competitor numbers (battles): 1-1, 5-1, and 5-5 resident,intruder battles. 3.,Workers of all three forms showed significant aggression toward non-nestmate conspecifics and heterospecifics. The results of the intra-specific aggression bioassays showed that S. invicta had the lowest aggression threshold, whereas S. richteri was the least aggressive. Survival rates 1 day after intra-specific encounters were higher for S. richteri than for S. invicta or hybrids, consistent with its lower aggressiveness. 4.,In inter-specific interactions, S. invicta workers showed the greatest aggression and were more aggressive towards S. richteri than to hybrids. Furthermore, survival 1 day after inter-specific encounters was highest for S. invicta workers, whether they were the intruders or residents. The hybrid form was intermediate between both parental forms in aggression and post-aggression survival. 5.,The live 1-1 and 5-5 battles produced similar and consistent results, but differences were amplified in the 5-5 battles, suggesting an effect of group size on aggression. These results may explain the observed shifts in the spatial distributions of the three forms and range restriction of S. richteri in southern United States. [source] Assessing the potential for fish predation to impact zebra mussels (Dreissena polymorpha): insight from bioenergetics modelsECOLOGY OF FRESHWATER FISH, Issue 2 2004M. A. Eggleton Abstract,,, Rates of annual food consumption and biomass were modeled for several fish species across representative rivers and lakes in eastern North America. Results were combined to assess the relative potential of fish predation to impact zebra mussels (Dreissena polymorpha). Predicted annual food consumption by fishes in southern waters was over 100% greater than that in northern systems because of warmer annual water temperatures and presumed increases in metabolic demand. Although generally increasing with latitude, biomasses of several key zebra mussel fish predators did not change significantly across latitudes. Biomasses of some less abundant fish predators did increase significantly with latitude, but increases were not of the magnitude to offset predicted decreases in food consumption. Our results generally support the premise that fishes in rivers and lakes of the southern United States (U.S.) have inherently greater potential to impact zebra mussels by predation. Our simulations may provide a partial explanation of why zebra mussel invasions have not been as rapid and widespread in southern U.S. waters compared to the Great Lakes region. Resumen 1Modelamos la tasa de consumo anual de alimento y biomasa para varias especies de peces en una muestra representativa de ríos y lagos del este de Norte América. Combinamos los resultados para evaluar el potencial relativo que estas especies de peces pueden ejercer sobre la abundancia del mejillón asiático Dreissena polymorpha. Las predicciones sobre consumo para peces en lagos y ríos del sur fueron más del 100% comparadas con sistemas septentrionales. Esto se puede deber a las temperaturas anuales más altas y aumentos en la demanda metabólica de peces en ríos y lagos del sur de Norte América. 2La biomasa de varias especies claves de peces que consumen D. polymorpha no cambió apreciablemente con latitud. La biomasa de algunos peces que consumen D. polymorpha aumentó significativamente con latitud, pero este aumento no era de una magnitud suficiente para compensar la disminución en el consumo de alimento. 3Nuestros resultados apoyan generalmente la premisa de que los peces en ríos y lagos del sur de los Estados Unidos (EE.UU.) tienen un potencial inherente mayor para poder controlar D. polymorpha. Nuestras simulaciones proporcionan una explicación parcial de por qué las invasiones de D. polymorpha no han sido tan rápidas y ampliamente distribuidas en aguas sureñas comparado con la región de los Grandes Lagos. [source] A dynamic mass budget for toxaphene in North AmericaENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2002Matthew MacLeod Abstract A continental-scale dynamic mass budget for toxaphene in North America is presented, based on available information on physicochemical properties, usage patterns, and reported environmental concentrations and using the Berkeley-Trent North American mass balance contaminant fate model (BETR North America). The model describes contaminant fate in 24 ecological regions of North America, including advective transport between regions in the atmosphere, freshwater, and near-shore coastal water. The dynamic mass budget accounts for environmental partitioning, transport, and degradation of the estimated 534 million kg of toxaphene that were used in North America as an insecticide and piscicide between 1945 and 2000. Satisfactory agreement exists between model results and current and historically reported concentrations of toxaphene in air, water, soil, and sediments throughout North America. An estimated 15 million kg of toxaphene are believed to remain in active circulation in the North American environment in the year 2000, with the majority in soils in the southern United States and Mexico, where historic usage was highest. Approximately 70% of total toxaphene deposition from the atmosphere to the Great Lakes is attributed to sources outside the Great Lakes Basin, and an estimated total of 3.9 million kg of toxaphene have been transported to this region from other parts of the continent. The toxaphene mass budget presented here is believed to be the first reported continental-scalemultimedia mass budget for any contaminant. [source] TEMPORAL PATTERN OF AFRICANIZATION IN A FERAL HONEYBEE POPULATION FROM TEXAS INFERRED FROM MITOCHONDRIAL DNAEVOLUTION, Issue 5 2004M. Alice Pinto Abstract The invasion of Africanized honeybees (Apis mellifera L.) in the Americas provides a window of opportunity to study the dynamics of secondary contact of subspecies of bees that evolved in allopatry in ecologically distinctive habitats of the Old World. We report here the results of an 11-year mitochondrial DNA survey of a feral honeybee population from southern United States (Texas). The mitochondrial haplotype (mitotype) frequencies changed radically during the 11-year study period. Prior to immigration of Africanized honeybees, the resident population was essentially of eastern and western European maternal ancestry. Three years after detection of the first Africanized swarm there was a mitotype turnover in the population from predominantly eastern European to predominantly A. m. scutellata (ancestor of Africanized honeybees). This remarkable change in the mitotype composition coincided with arrival of the parasitic mite Varroa destructor, which was likely responsible for severe losses experienced by colonies of European ancestry. From 1997 onward the population stabilized with most colonies of A. m. scutellata maternal origin. [source] The Relationship Between Classroom Motivation and Academic Achievement in Elementary-School-Aged ChildrenFAMILY & CONSUMER SCIENCES RESEARCH JOURNAL, Issue 2 2004Sheri Coates Broussard The relationship between motivation and academic success has been better established with older children and adults than with younger children. As part of a larger project, the purpose of this study was to examine the relation-ship between classroom motivation and academic achievement in young elementary-school-aged children. The participants were 122 first-grade and 129 third-grade children from a mid-sized city in the southern United States. The findings from the current study were consistent with previous research in that higher levels of mastery motivation and judgment motivation were found to be related to higher math and reading grades in third graders. However, higher levels of mastery motivation, not judgment motivation, were related to higher math and reading grades in first graders. [source] A study of best practices in training transfer and proposed model of transferHUMAN RESOURCE DEVELOPMENT QUARTERLY, Issue 2 2008Lisa A. Burke Data were gathered from a sample of training professionals of an American Society of Training and Development (ASTD) chapter in the southern United States regarding best practices for supporting training transfer. Content analysis techniques, based on a rigorous methodology proposed by Insch, Moore, & Murphy (1997), were used to analyze the rich data. Findings suggest that interventions for bolstering training transfer are best carried out in the work context and design and delivery phase, take place after training or during, and involve trainers and supervisors. Activities garnering top attention from trainers as best practices include (starting with most frequently reported) supervisory support activities, coaching, opportunities to perform, interactive training activities, transfer measurement, and job-relevant training. Several new transfer variables also emerged from the data, indicating existing transfer models can be further refined. Ultimately, we propose a refined model of transfer to extend human resource development (HRD) theory in the area of transfer. [source] The Health Consequences of Cultural Consonance: Cultural Dimensions of Lifestyle, Social Support, and Arterial Blood Pressure in an African American CommunityAMERICAN ANTHROPOLOGIST, Issue 2 2000William W. Dressler Cultural dimensions of health and behavior have been difficult to study because of limited theoretical and methodological models linking the cultural, the individual, and the biological. We employ a cognitive theory of culture to understand culture and health in an African American community in the southern United States. First, cultural consensus analysis is used to test for shared cultural models of lifestyles and social supports within the community. Then, the theoretical and operational construct of "cultural consonance" is used to assess the degree to which individuals behave in a way consistent with cultural models. Findings indicate that cultural consonance in lifestyle and social support combine synergistically in association with blood pressure. These associations of cultural consonance and health are not altered by taking into account a variety of other variables, indicating an independent association of cultural dimensions of behavior with health status. Implications of these results for culture theory are discussed, [culture theory, culture consensus analysis, cultural consonance, African American community, arterial blood pressure] [source] Declining Antibiotic Prescriptions for Upper Respiratory Infections, 1993,2004ACADEMIC EMERGENCY MEDICINE, Issue 4 2007Stefan G. Vanderweil BA Abstract Objectives: To examine antibiotic prescribing trends for U.S. emergency department (ED) visits with upper respiratory tract infections (URIs) between 1993 and 2004. Methods: Data were compiled from the National Hospital Ambulatory Medical Care Survey (NHAMCS). URI visits were identified by using ICD-9-CM code 465.9, whereas antibiotics were identified using the National Drug Code Directory class Antimicrobials. A multivariate logistic regression model revealed sociodemographic and geographic factors that were independently associated with receipt of an antibiotic prescription for URIs. Results: There were approximately 23.4 million ED visits diagnosed as URIs between 1993 and 2004. Although the proportion of URI diagnoses remained relatively stable (p trend = 0.26), a significant decrease in provision of antibiotic prescriptions for URIs occurred during this 12-year period, from a maximum of 55% in 1993, to a minimum of 35% in 2004. Patients who were prescribed antibiotics were more likely to be white than African American and to have been treated in EDs located in the southern United States. Conclusions: Antibiotic prescribing for URIs continues to decrease, a favorable trend that suggests that national efforts to reduce inappropriate antibiotic usage are having some success. Nevertheless, the frequency of antibiotic treatment for URI in the ED remains high (35%). Future efforts to reduce inappropriate antibiotic prescribing may focus on patients and physicians in southern U.S. EDs. Additional work is needed to address continued evidence of race-related disparities in care. [source] | |||||||||||||