Antler asymmetry and immunity in reindeer

Fluctuating asymmetry (FA) measures an individual's ability to undergo identical development in bilaterally symmetrical characters and may indicate sensitivity to environmental stress. FA in ornamental characters is often positively related to parasite intensities, which are important environmental stressors. Parasites affect and are affected by several parts of the immune system, and the ability to resist parasites may be signalled via FA in ornaments. In this study we examined reindeer antlers, which show FA, demonstrated to be caused by parasite infections. We measured antler FA, immune parameters (i.e. densities of different classes of leukocytes, IgG levels and abomasal lymph node numbers) and intensity of abomasal nematodes in free-ranging 1.5-year-old male reindeer slaughtered in the early part of their rutting period. We found a relationship between parasite intensity and immune parameters suggesting that our measures of immune activity reflect density of current parasite infections. More important, these immune parameters were associated with FA in both the main beam length and numbers of antler tines. The immune parameters were, however, only weakly correlated to antler size. This indicates that FA, but not size, of antlers grown during exposure to a multitude of environmental stressors may reveal information about individual immunity that can be important for host-parasite interactions. Antler FA may therefore communicate an individual's quality during the rut in reindeer. Received: 30 March 1998 / Accepted after revision: 15 August 1998     

斜坡区和隆起区断裂密集带差异性及其对油气分布的控制作用

此文以霸县凹陷文安斜坡和饶阳凹陷留楚构造为研究对象,对比了斜坡区和隆起区断裂密集带的特征及其对不同构造部位油气分布的控制作用。在三维地震资料、钻井资料和已发现油气藏特征的基础上,利用断裂密集带识别方法和分类方案,识别出文安斜坡和留楚构造的断裂密集带,并对其进行了分类。对比两种构造部位断裂密集带发育的差异性及对油气分布的控制作用,认为隆起区(留楚构造)相对于斜坡区(文安斜坡)断裂密集带发育数量较少,规模大,斜坡区断裂密集带主要以顺向背形断裂密集带为主,而隆起区主要以屋脊背形断裂密集带为主,隆起区油气主要分布在顺向背形断裂密集带内,斜坡区主要分布在屋脊背形断裂密集带内部及靠近生烃中心的边部。     

Institutional responses to development pressures: Resilience of social-ecological systems in Himachal Pradesh,India

In the Kullu District, Himachal Pradesh, India, economic and urban growth, and diversification have increased pressure on forests and forest-based social-ecological systems. As in many Himalayan regions, livelihood sustainability is linked to forest resources, products and services. Recent development in the region, to which these systems may be vulnerable, brings into question environmental and livelihood sustainability. This paper examines the resilience of integrated systems of people and nature, or social-ecological systems, in the face of development pressures by evaluating a number of local and state-level institutional responses. Resilience, which describes the ability of the social-ecological systems to adapt to change by buffering shocks, improving self-organization and increasing capacity for learning, is an essential quality for sustainable development. Institutional responses which positively contribute to resilience and sustainability include the work of mahila mandals in forest management, adoption of Joint Forest Management (JFM) policies and practices, upholding rules, strengthening local institutions, establishing firewood depots and adopting alternative energy sources. Institutional failures brought about by the lack of rule enforcement and corruption erode resilience. The analysis of institutional responses helps to identify areas where capacity exists and areas in which capacity building is needed to produce resilient social-ecological systems and therefore, sustainable development.     

HIV Infection in Pregnant Women: A 2020 Update

Acquired immunodeficiency syndrome (AIDS) was first described in 1981, and continues to be one of the worst global health pandemics in recorded history. Concerted international efforts have helped to increase awareness of human immunodeficiency (HIV) status, improve access to treatment and continuation of therapy to achieve viral suppression with a goal of ending the AIDS epidemic by 2030. The clinical outcomes for patients living with HIV on combined antiretroviral therapy are considerably improved with prolonged life expectancy and superior quality of life. Further, perinatal transmission rates have dramatically decreased with elimination of mother to child transmission of HIV in a growing number of countries worldwide. However, there have been significant reductions in the pace of progress in treatment expansion for pregnant women with failure to meet global targets in 2018. In this review, we will highlight recent advances and challenges ahead in 2020 for three areas of perinatal care for women with HIV in developed countries: (a) pregnancy planning considerations, (b) impact of antiviral medications on perinatal outcomes, and (c) infant feeding practices. The promise of a HIV-free generation is on the horizon and continued international efforts in preventing perinatal transmission are an important component of this achievement.     

Passivsammler für die zeitintegrierte chemische und toxikologische Überwachung des Schadstoffgehaltes in Grund- und Oberflächenwasser

The availability of high-quality water plays a pivotal role for the protection of the ecosystem and the quality of human life. An important step in assessing ground and surface water quality is sampling. The time-integrated accumulation of environmental contaminants by passive sampling is an attractive alternative to conventional snap-shot sampling. Thein situ accumulation during passive sampling allows the detection of even lowconcentrated contaminants and reduces cost and time for continuous monitoring. Passive sampling provides information on the whole sampling period and avoids the transport and storage of large sample volumes. Matrix effects are reduced due to the selective enrichment. Various passive samplers have been developed for sampling in aqueous media. Early developments used water filled dialysis tubes for the sampling of trace elements. Later on, solvent filled devices and triolein-filled semipermeable membrane devices (SPMDs) were deployed. More recent developments use a solid rather than a liquid sorbent as the receiving phase. Examples of this are the solid phase microextraction (SPME) and the membrane enclosed sorptive coating (MESCO). In addition to comprising miniature devices, SPMEs as well as MESCO are thermodesorbable and, as such, no longer require solvent extraction. Conventionally the sampled contaminants are removed from the passive sampling devices by solvent extraction or thermodesorption in order to be analyzed chemically. For an in-depth analysis of sampled analytes, however, it would be advantageous to modify passive sampling such that sampled contaminants can also be analyzed biologically. Thus, it is our goal to construct a passive sampling device that serves both as a sampling device as well as an exposure chamber for toxicity testing. The principle underlying this technology is the bioavailability of sorbed contaminants, thereby eliminating the need for solvent extraction.     

Eye movement and reaction time measures of the effectiveness of caution signs

The effectiveness of various forms of caution signs was evaluated using saccadic eye movements and reaction time as the dependent variables. Both dependent measures show that caution signs requiring specific positive actions are processed more slowly and less efficiently than signs requiring avoidance behaviors. Additionally, the data show that changing the order of the “consequences” and “instructions” elements of the caution signs did not influence the number of saccades, the speed, or accuracy of interpretation. The research shows that saccadic eye movement may be an effective method for evaluating the design of caution signs.     

Seaweed richness and herbivory increase rate of community recovery from disturbance

The importance of herbivores and of plant diversity for community succession and recovery from disturbance is well documented. However, few studies have assessed the relative magnitude of, or potential interactions between, these factors. To determine the combined effect of herbivory and surrounding algal species richness on the recovery of a rocky intertidal community, we conducted a 27-month field experiment assessing algal recruitment and succession in cleared patches that mimic naturally forming gaps in the ambient community. We crossed two herbivore treatments, ambient and reduced abundance, with monocultures and polycultures of the four most common algal species in a mid-high rocky intertidal zone of northern California. We found that both the presence of herbivores and high surrounding algal richness increased recovery rates, and the effect of algal richness was twice the magnitude of that of herbivores. The increased recovery rate of patches containing herbivores was due to the consumption of fast-growing, early colonist species that preempt space from perennial, late-successional species. Mechanisms linking algal richness and recovery are more numerous. In polycultures, herbivore abundance and species composition is altered, desiccation rates are lower, and propagule recruitment, survival, and growth are higher compared to monocultures, all of which could contribute the observed effect of surrounding species richness. Herbivory and species richness should jointly accelerate recovery wherever palatable species inhibit late-successional, herbivore-resistant species and recruitment and survival of new colonists is promoted by local species richness. These appear to be common features of rocky-shore seaweed, and perhaps other, communities.