Forest edges enhance mate-finding in the European gypsy moth, Lymantria dispar

Understanding movement capabilities of individuals within a landscape is essential to identifying the effects of habitat boundaries on species abundances, ranges, and spread rates. Movement barriers due to habitat fragmentation may reduce mate-finding ability in some species, particularly in heterogeneous landscapes containing low-density populations. This study focuses on the effects of habitat type and edge on mate-finding in an invasive defoliator, the European gypsy moth. Adult European gypsy moth males locate mates by following pheromones released by flightless females. Reduced mate-finding was expected in fields and near forest edges based on geographic variation in invasion rates and pheromone plume dynamics. A male release-recapture experiment using female-baited traps in fields, at forest edges, and in the forest interior showed that mate-finding was highest at forest edges, reduced in fields, and lowest within the forest interior. This suggests that forest edges and moderate habitat fragmentation enhance mate-finding in the gypsy moth

I can sit but I’d rather stand: Commuter’s experience of crowdedness and fellow passenger behaviour in carriages on Australian metropolitan trains

For many people in Australia, crowding is a major issue and an unavoidable aspect of their daily rail commute. Australian passenger experiences, perceptions of, and their reactions to crowding are not well understood. To gain an understanding of passenger perceptions and tolerance of railway crowding and the impact of passenger behaviour on the crowding experience, qualitative (Stage 1) and quantitative (Stage 2) fieldwork was undertaken between 2009 and 2010 across the five metropolitan railways in Australia. Some results from Stage 1, a two-part qualitative study are given. This involved ethnographic participant observations on trains in five States and 20 focus groups with a total of 179 Australian rail passengers. Focus group participants discussed their reactions to being in close proximity to others in a closed environment and these are examined. This paper will explore the ways in which passengers experience, tolerate and construct perceptions of crowdedness through both avoidance techniques and interactions with fellow passengers

Frustrations, Fights, and Friendships: The Physical, Emotional, and Behavioural Effects of High-Density Crowding on Mumbai’s Suburban Rail Passengers

Crammed together in tight folds of humanity, the suburban rail passengers of Mumbai, India, experience the most densely crowded trains in the world (Basu & Hunt, 2012). Whilst the immediate physical descriptors of crowdedness in Mumbai are well understood (Hirsch, 2016), there is little knowledge of the effect this has on the multitude of passengers. This is an important omission, as the effects of crowding on passengers impact their attitudes, travel behavior, and travel decisions. This paper therefore seeks to discern the physical, emotional, and behavioural effects of rail passenger crowding in Mumbai, India. To achieve this, a qualitative methodology, including 49 face-to-face interviews and 48 hours of ethnographic and autoethnographic observations in Mumbai were conducted. Mumbai is an ideal place to study these effects as it has high-density crowding, the likes of which are not experienced elsewhere. Additionally, there is a limited understanding of the effect of crowding on passengers in non-Western societies. With increasing rail ridership worldwide, the experiences of Mumbai’s passengers within high densities may align with the future experiences of passengers in other Western and non-Western countries. For academics and service providers, understanding the specifics of the crowd, such as the density, passenger perceptions, and culture is important. With that knowledge, strategies to improve the experience of crowding would be more effective

Third Quarterly Report: Mississippi Woman Suffrage Association

Recounts activities of the associationhttps://egrove.olemiss.edu/suffrage/1022/thumbnail.jp

Molecular Mechanisms Protecting Centromeres From Self-Sabotage and Implications for Cancer Therapy

Centromeres play a crucial role in DNA segregation by mediating the cohesion and separation of sister chromatids during cell division. Centromere dysfunction, breakage or compromised centromeric integrity can generate aneuploidies and chromosomal instability, which are cellular features associated with cancer initiation and progression. Maintaining centromere integrity is thus essential for genome stability. However, the centromere itself is prone to DNA breaks, likely due to its intrinsically fragile nature. Centromeres are complex genomic loci that are composed of highly repetitive DNA sequences and secondary structures and require the recruitment and homeostasis of a centromere-associated protein network. The molecular mechanisms engaged to preserve centromere inherent structure and respond to centromeric damage are not fully understood and remain a subject of ongoing research. In this article, we provide a review of the currently known factors that contribute to centromeric dysfunction and the molecular mechanisms that mitigate the impact of centromere damage on genome stability. Finally, we discuss the potential therapeutic strategies that could arise from a deeper understanding of the mechanisms preserving centromere integrity

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

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