188 research outputs found
Third Quarterly Report: Mississippi Woman Suffrage Association
Recounts activities of the associationhttps://egrove.olemiss.edu/suffrage/1022/thumbnail.jp
Geographic Variation in Larval Metabolic Rate Between Northern and Southern Populations of the Invasive Gypsy Moth
Thermal regimes can diverge considerably across the geographic range of a species, and accordingly, populations can vary in their response to changing environmental conditions. Both local adaptation and acclimatization are important mechanisms for ectotherms to maintain homeostasis as environments become thermally stressful, which organisms often experience at their geographic range limits. The spatial spread of the gypsy moth (Lymantria dispar L.) (Lepidoptera: Erebidae) after introduction to North America provides an exemplary system for studying population variation in physiological traits given the gradient of climates encompassed by its current invasive range. This study quantifies differences in resting metabolic rate (RMR) across temperature for four populations of gypsy moth, two from the northern and two from southern regions of their introduced range in North America. Gypsy moth larvae were reared at high and low thermal regimes, and then metabolic activity was monitored at four temperatures using stop-flow respirometry to test for an acclimation response. For all populations, there was a significant increase in RMR as respirometry test temperature increased. Contrary to our expectations, we did not find evidence for metabolic adaptation to colder environments based on our comparisons between northern and southern populations. We also found no evidence for an acclimation response of RMR to rearing temperature for three of the four pairwise comparisons examined. Understanding the thermal sensitivity of metabolic rate in gypsy moth, and understanding the potential for changes in physiology at range extremes, is critical for estimating continued spatial spread of this invasive species both under current and potential future climatic constraints
Thermal Physiology and Developmental Plasticity of Pigmentation in the Harlequin Bug (Hemiptera: Pentatomidae)
Traits that promote the maintenance of body temperatures within an optimal range provide advantages to ectothermic species. Pigmentation plasticity is found in many insects and enhances thermoregulatory potential as increased melanization can result in greater heat retention. The thermal melanism hypothesis predicts that species with developmental plasticity will have darker pigmentation in colder environments, which can be an important adaptation for temperate species experiencing seasonal variation in climate. The harlequin bug (Murgantia histrionica, Hemiptera: Pentatomidae, Hahn 1834) is a widespread invasive crop pest with variable patterning where developmental plasticity in melanization could affect performance. To investigate the impact of temperature and photoperiod on melanization and size, nymphs were reared under two temperatures and two photoperiods simulating summer and fall seasons. The size and degree of melanization of adults were quantified using digital imagery. To assess the effect of coloration on the amount of heat absorption, we monitored the temperature of adults in a heating experiment. Overall, our results supported the thermal melanism hypothesis and temperature had a comparatively larger effect on coloration and size than photoperiod. When heated, the body temperature of individuals with darker pigmentation increased more relative to the ambient air temperature than individuals with lighter pigmentation. These results suggest that colder temperatures experienced late in the season can induce developmental plasticity for a phenotype that improves thermoregulation in this species. Our work highlights environmental signals and consequences for individual performance due to thermal melanism in a common invasive species, where capacity to respond to changing environments is likely contributing to its spread
Physiological Responses to Elevated Temperature across the Geographic Range of a Terrestrial Salamander
Widespread species often possess physiological mechanisms for coping with thermal heterogeneity, and uncovering these mechanisms provides insight into species responses to climate change. The emergence of non-invasive corticosterone (CORT) assays allows us to rapidly assess physiological responses to environmental change on a large scale. We lack, however, a basic understanding of how temperature affects CORT, and whether temperature and CORT interactively affect performance. Here, we examine the effects of elevated temperature on CORT and whole-organism performance in a terrestrial salamander, Plethodon cinereus, across a latitudinal gradient. Using water-borne hormone assays, we found that raising ambient temperature from 15 to 25°C increased CORT release at a similar rate for salamanders from all sites. However, CORT release rate was higher overall in the warmest, southernmost site. Elevated temperatures also affected physiological performance, but the effects differed among sites. Ingestion rate increased in salamanders from the warmer sites but remained the same for those from cooler sites. Mass gain was reduced for most individuals, though this reduction was more dramatic in salamanders from the cooler sites. We also found a temperature-dependent relationship between CORT and food conversion efficiency (i.e., the amount of mass gained per unit food ingested). CORT was negatively related to food conversion efficiency at 25°C but was unrelated at 15°C. Thus, the energetic gains of elevated ingestion rates may be counteracted by elevated CORT release rates experienced by salamanders in warmer environments. By integrating multiple physiological metrics, we highlight the complex relationships between temperature and individual responses to warming climates
Evaluation of spatial and temporal changes in groundwater levels using RS and GIS- a case study of Malleboinpalli area, Mahaboob nagar district,A.P. (state).
Data frame containing information of each trap and their corresponding session, site, and day covariat
Climate-Related Geographical Variation in Performance Traits across the Invasion Front of a Widespread Non-Native Insect
Aim
Invasive species are ideal systems for testing geographical differences in performance traits and measuring evolutionary responses as a species spreads across divergent climates and habitats. The European gypsy moth, Lymantria dispar dispar L. (Lepidoptera: Erebidae), is a generalist forest defoliator introduced to Medford, Massachusetts, USA in 1869. The invasion front extends from Minnesota to North Carolina and the ability of this species to adapt to local climate may contribute to its continuing spread. We evaluated the performance of populations along the climatic gradient of the invasion front to test for a relationship between climate and ecologically important performance traits. Location
Eastern United States of America Taxon
Lymantria dispar dispar L. (Lepidoptera: Erebidae) Methods
Insects from 14 populations across the US invasion front and interior of the invasive range were reared from hatch to adult emergence in six constant temperature treatments. The responses of survival, pupal mass and larval development time were analysed as a function of source climate (annual mean normal temperature), rearing temperature and their interaction using multiple polynomial regression. Results
With the exception of female development time, there were no significant interactions between source climate and rearing temperature, indicating little divergence in the shape of thermal reaction norms among populations. Source population and rearing temperature were significant predictors of survival and pupal mass. Independent of rearing temperature, populations from warmer climates had lower survival than those from colder climates, but attained larger body size despite similar development times. Larval development time was dependent on rearing temperature, but there were not consistent relationships with source climate. Main Conclusions
Thermal adaptation can be an important factor shaping the spread of invasive species, particularly in the context of climate change. Our results suggest that L. d. dispar is highly plastic, but has undergone climate-related adaptation in thermal performance and life-history traits as it spread across North America
Nine Strategies to Guide Efforts to Reduce Youth Gun Violence
Gun violence, including that perpetrated by young people, is a pernicious problem for many communities, particularly those facing historically high levels of concentrated disadvantage and disinvestment. To effectively address youth gun violence and establish and maintain peace, communities need stable safety infrastructures and effective interventions.We developed a research-based practice guide to help local governments, law enforcement agencies, and antiviolence organizations determine how to shape their approaches to reducing gun violence perpetrated by young people ages 10 to 25 in gangs or groups. Here, we summarize the guide's recommendations on how to develop effective interventions and build a broader safety infrastructure that supports the success of different partners working to protect young people and communities from gun violence
A Research-Based Practice Guide to Reduce Youth Gun and Gang/Group Violence
While extensive research exists, the field lacks a current and translational synthesis of what works to reduce youth group and gun violence. In response, the Urban Institute developed a research-based practice guide to inform local government, law enforcement, and community-violence-intervention stakeholders as they implement new antiviolence interventions and refine existing ones. To inform the development of the guide, Urban researchers conducted a comprehensive literature synthesis of research on violence reduction interventions and conducted a scan of interventions representing well-known antiviolence models and other innovative strategies. Drawing on the findings from the literature synthesis and scan of practice, the practice guide presents recommendations around nine practice areas related to building an infrastructure to support a multi-faceted antiviolence strategy and implementing effective violence reduction programs
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