Fertility signaling—the proximate mechanism of worker policing in a clonal ant

In eusocial insects, the ability to regulate reproduction relies on cues that signal the presence of fertile individuals. We investigated the variation of cuticular hydrocarbons (CHCs) with reproductive status in Platythyrea punctata, an ant, in which all workers are capable of producing daughters from unfertilized eggs (thelytoky). Who reproduces is determined through dominance and worker policing. New reproductives, which developed their ovaries after separation from an old reproductive for a short period of time, were attacked by nonreproductives upon reintroduction into their colony. In contrast, aggression against new reproductives with fully developed ovaries, which had been separated over a longer period, was initiated by fights between old and new reproductives. CHC profiles varied with ovarian development. New reproductives were only attacked when they expressed a CHC profile similar to old reproductives, but not when it was similar to that of nonreproductives. CHCs appear to signal the fertility of individuals and induce policing behavior towards surplus reproductive workers.     

Factors related to seat belt use among fatally injured teenage drivers

PROBLEM: In the United States, teenage drivers have a higher crash risk and lower observed seat belt use than other age groups. METHOD: Seat belt use was examined for teenage (16-19 years) drivers who were fatally injured in traffic crashes occurring in the United States during the years 1995-2000. Vehicle, driver, and crash factors potentially related to belt use were examined. State differences in belt use rates among fatally injured teenage drivers were related to states' observed belt use rates for all ages and other state-level variables. RESULTS: During 1995-2000, mean belt use was 36% among fatally injured teenage drivers and 23% among fatally injured teenage passengers. One of the strongest predictors of higher belt use for both drivers and passengers was whether the crash occurred in a state with a primary seat belt law. Belt use rates for 1995-2000 for fatally injured teenage drivers ranged from 20% or less in six states to more than 60% in two states. States with the highest use rates were those with strong primary belt use laws and those with high rates of observed belt use for all ages. Lower belt use among fatally injured teenage drivers was associated with increasing age; male drivers; drivers of SUVs, vans, or pickup trucks rather than cars; older vehicles; crashes occurring late at night; crashes occurring on rural roadways; single vehicle crashes; and drivers with BACs of 0.10 or higher. Teenage driver belt use declined as the number of teenage passengers increased, but increased in the presence of at least one passenger 30 years or older. IMPACT ON TRAFFIC SAFETY: It is suggested that to increase teenage belt use, states should enact strong primary belt use laws and mount highly publicized efforts to enforce these laws. Graduated driver licensing systems should incorporate strong provisions that require seat belt use by teenage drivers and passengers.     

剑桥大学校长谈环境教育

■概览具有近８００年历史的剑桥大学绝对不是所谓的“象牙塔”——疯狂的教授们在脱离尘世的地方追求着所谓的“理想世界”。从一开始,剑桥大学就是为实用所建。早在５００年前这所古老大学的目标和任务就被描述如下：用正确的和实用的教育以确保始终都有为社会服务的精英人士。所以说我们在环境科学领域的努力也可以用以下三个词来描述：教育、科研和行动。许多大学都成立了独立的环境科学系,而剑桥却没有,为什么呢？有这样几条原因：首先,当环境研究开始被许多大学关注时,在剑桥早已有许多不同的系别在共同从事环境科学领域的研究;…     

Methane and carbon dioxide dynamics in wetland mesocosms: effects of hydrology and soils.

Methane and carbon dioxide fluxes in created and restored wetlands, and the influence of hydrology and soils on these fluxes, have not been extensively documented. Minimizing methane fluxes while maximizing productivity is a relevant goal for wetland restoration and creation projects. In this study we used replicated wetland mesocosms to investigate relationships between contrasting hydrologic and soil conditions, and methane and carbon dioxide fluxes in emergent marsh systems. Hydrologic treatments consisted of an intermittent flooding regime vs. continuously inundated conditions, and soil treatments utilized hydric vs. non-hydric soils. Diurnal patterns of methane flux were examined to shed light on the relationship between emergent macrophytes and methane emissions for comparison with vegetation-methane relationships reported from natural wetlands. Microbially available organic carbon content was significantly greater in hydric soils than nonhydric soils, despite similar organic matter contents in the contrasting soil types. Mesocosms with hydric soils exhibited the greatest rates of methane flux regardless of hydrology, but intermittent inundation of hydric soils produced significantly lower methane fluxes than continuous inundatation of hydric soils. Methane fluxes were not affected significantly by hydrologic regime in mesocosms containing non-hydric soils. There were no diurnal differences in methane flux, and carbon dioxide and methane fluxes were not significantly correlated. The highest rates of CO2 uptake occurred in the continuously inundated treatment with non-hydric soils, and there were no significant differences in nighttime respiration rates between the treatments. Implications for hydrologic design of created and restored wetlands are discussed.     

Why cumulative impacts assessments of hydrocarbon activities in the Arctic fail to meet their purpose

Regional Environmental Change - The Arctic Region is characterised by vulnerable ecosystems and residing indigenous people, dependent on nature for subsistence fishing and hunting. The Arctic also...     

Usage,definition, and measurement of coexistence,tolerance and acceptance in wildlife conservation research in Africa

The terms ‘coexistence’, ‘tolerance,’ and ‘acceptance’ appear frequently in conservation literature, but lack consistent characterization, making them difficult to apply across intervention frameworks. This review aims to describe the common characterizations of these three terms using Africa-based research as a case study. Through systematic lexical searches, we identified 392 papers containing one or more of the three terms. We assessed their usage, definition, and measurement (or lack thereof) in wildlife conservation. Coexistence was used in 46% of papers, but was defined in only 2% and measured in 4%. Tolerance and acceptance were used in 63% and 61% of the papers in which they appeared, respectively, defined in 4% and 2%, and measured in 19% and 5%. These results confirm the lack of clear understanding of these concepts and evidence the need for a precise lexicon. This would allow conservationists to cohesively describe their work and increase replicability of research across contexts.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01352-6) contains supplementary material, which is available to authorized users.     

Unlikely lead-bearing phases in river and estuary sediments near an ancient mine (Huelgoat,Brittany, France)

Environmental Science and Pollution Research - Anthropocene mineral diversity is the result of the purification of metals naturally combined with other chemical elements in natural environment....     

Feedbacks in Human–Landscape Systems

This article identifies key questions and challenges for geomorphologists in investigating coupled feedbacks in human–landscape systems. While feedbacks occur in the absence of human influences, they are also altered by human activity. Feedbacks are a key element to understanding human-influenced geomorphic systems in ways that extend our traditional approach of considering humans as unidirectional drivers of change. Feedbacks have been increasingly identified in Earth-environmental systems, with studies of coupled human–natural systems emphasizing ecological phenomena in producing emerging concepts for social–ecological systems. Enormous gaps or uncertainties in knowledge remain with respect to understanding impact-feedback loops within geomorphic systems with significant human alterations, where the impacted geomorphic systems in turn affect humans. Geomorphology should play an important role in public policy by identifying the many diffuse and subtle feedbacks of both local- and global-scale processes. This role is urgent, while time may still be available to mitigate the impacts that limit the sustainability of human societies. Challenges for geomorphology include identification of the often weak feedbacks that occur over varied time and space scales ranging from geologic time to single isolated events and very short time periods, the lack of available data linking impact with response, the identification of multiple thresholds that trigger feedback mechanisms, the varied tools and metrics needed to represent both physical and human processes, and the need to collaborate with social scientists with expertise in the human causes of geomorphic change, as well as the human responses to such change.