The downfall of mating: the effect of mate-carrying and flight muscle ratio on the escape ability of a pierid butterfly

In many species, the ability to evade predators is known to be periodically impaired by increased weight loads due to feeding and reproduction. Not only may extra weight reduce escape speed, but feeding and mating can also make the prey more noticeable to visually hunting predators. A number of butterfly species mate for hours, and if a mating couple is disturbed, one of the butterflies is responsible for flying, whereas its partner remains still. This study investigated the ability of male Pieris napi butterflies to fly while mating, with the prediction that mate carrying impairs flight ability compared to single flying males and that males with relatively high flight muscle ratios (FMR; male thorax mass/male + female body mass) will have better flight performance in copula. Our results clearly show that whereas single males always take off at steep angles and fly upwards, couples invariably have a negative take-off angle and rarely gain height. Moreover, landing height of the couples is positively associated with higher FMR. Hence, male flight ability when in copula is positively associated with a high relative thorax mass. Butterfly pairs may thus be at greater risk of predation as a consequence of their impaired flight ability, especially couples with critically low FMRs (<16%).     

Effective Transboundary Aquifer Areas: An Approach for Transboundary Groundwater Management

The natural complexity, heterogeneity, and extent of transboundary aquifers around the world, have led to controversy over which method or criteria should be used to identify and delineate their boundaries. Currently, there is no standard methodology that aquifer‐sharing countries can use to delineate the area of a transboundary aquifer. In the case of Mexico and Texas, Mexico uses administrative boundaries, whereas Texas uses geological boundaries. This paper proposes a method for delineation and prioritization of aquifers (or aquifer areas) called effective transboundary aquifer areas (ETAAs), which uses a combination of physical criteria (geological boundaries, topography, and hydrography) and the location and density of active water wells in the borderland between Mexico and Texas. This method identifies the area of priority (productivity area) in the aquifer using pumping patterns or hot spots regardless of the aquifer’s surficial geological limits, therefore offering a more effective, local and practical management option at the transboundary level. Different geological features or pumping patterns will have different sizes and locations of ETAAs within the same aquifer. In West Texas, which is dominated by bolsons, the method produces limited options for ETAAs, whereas in South Texas in the easternmost border the identified ETAAs are more significant.     

Herbicides based on 2,4-D: its behavior in agricultural environments and microbial biodegradation aspects. A review

Environmental Science and Pollution Research - One of the main herbicides used in the agricultural environments is 2,4-dichlorophenoxyacetic acid (2,4-D). It is a synthetic plant hormone auxin...     

Matrix effect in case of purification of oily waters by membrane separation combined with pre-ozonation

In the present study, oil in water emulsions (c_oil?=?100 ppm; d_{oil droplets}?<?2 μm) was purified with ozonation followed by microfiltration using polyethersulfone (PES) membrane (d_pore?=?0.2 μm). The effects of pre-ozonation on membrane microfiltration were investigated in detail both in case of ultrapure and model groundwater matrices, applying different durations (0, 5, 10, and 20 min) of pre-ozonation. Simultaneously, the effects of added inorganic water components on the combined method were investigated. Size distribution of oil droplets, zeta potentials, fluxes, and purification efficiencies were measured and fouling mechanisms were described in all cases. It was found that the matrix significantly affected the size distribution and adherence ability of oil droplets onto the membrane surface, therefore fouling mechanisms also were strongly dependent on the matrix. In case of low salt concentration, the total resistance was caused mainly by reversible resistance, which could be significantly reduced (eliminated) by pre-ozonation. In case of model groundwater matrix, nearly twice higher total resistance was measured, and irreversible resistance was dominant, because of the higher adhesion ability of the oil droplets onto the membrane surface. In this case, pre-ozonation resulted in much lower irreversible, but higher reversible resistance. Increased duration of pre-ozonation raised the total resistance and reduced the elimination efficiency (due to fragmented oil droplets and water soluble oxidation by-products) in both cases, therefore short pre-ozonation can be recommended both from economic and performance aspects.     

Perspectives of farmers and tourists on agricultural abandonment in east Lesvos,Greece

Regional Environmental Change - Multi-stakeholder perceptions of landscape changes are increasingly recognized as essential inputs to discussions on future landscape developments, particularly when...     

Escape take-off strategies in birds: the significance of protective cover

Avian escape strategy is highly dependent on the ability to fly, and the success rate of raptor attacks is reduced if the prey gets fully airborne. Therefore, when escaping from predator attacks, the initial take-off is crucial and a rapid take-off, high velocity, and high angle of ascent maximize the chance of survival. However, due to the laws of gravity, birds face a trade-off between maximizing its linear acceleration and maximizing its rate of climb when taking off. The optimal policy between velocity and angle of ascent when a bird escapes from an attacking predator might depend on the detailed nature of the predator’s attack, the proximity to cover, and the presence of conspecifics. Many small birds rely on a quick dash to protective cover. In this study, we examine how the availability of protective cover affects take-off strategy in birds. Male great tits (Parus major) were subjected to a surprise attack by a model predator either in the presence or absence of protective cover. When attacked by the predator, great tits took off and perched in the cover when it was available. Birds subjected to the predator attack in the absence of cover took off in 10° higher angle of ascent and flew faster in the start of the take-off, compared to birds that took off in the presence of cover. Thus, this study for the first time shows that a bird do trade off speed with angle of ascent in an adaptive way, depending on the presence of protective cover.     

Occupational exposure

Concentrations of polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), hexachlorobenzene and methylsulphonyl metabolites of PCB were determined in blood plasma from potentially exposed workers and controls. Three of the potentially exposed subjects had worked with cable incineration and two were electricians. Extraction of the organochlorine compounds and lipids were performed using the lipophilic gel Lipidex. Different adsorbents and gel permeation chromatography were applied for further purification of the samples and separation of analytes. Determinations of the chlorinated compounds were made by using gas chromatography with electron-capture detection and gas chromatography-mass spectrometry. Only small differences in the concentrations of organochlorine compounds were found in the plasma from the three subject groups. Thus, specific exposure of the workers could not be confirmed.     

Social perceptions of the impacts of Colombo water supply projects

The complexity of development activities, in which the interactions between various forces often mean that outcomes are unpredictable and unanticipated, highlights the importance of objective and comprehensive evaluations. In the specific case of the evaluation of towns east and south of Colombo water supply projects, the findings have major implications for the implementation of the Millennium Development Goals, if the water-related objectives are to be fulfilled. The study found that 30% of the households of these towns that are receiving clean, piped water are not using it for drinking. Instead, they are continuing to drink contaminated well water. Whereas it is considered that the main beneficiaries of water supply projects have been women and people who are sick, elderly, or disabled, the general perception is that the health conditions of the families have not improved with the provision of clean water (in fact, many claim that their health conditions have deteriorated). In spite of the higher cost of the supplied water, people are willing to pay for it as long as the supply is reliable.     

Water management for a megacity: Mexico City Metropolitan Area

The paper presents an overview of the present situation of the Mexico City Metropolitan Area (MCMA). The analysis indicates an urgent need to radically improve the current water supply and wastewater management practices, to become sustainable. The MCMA is one of the most rapidly growing urban centers of the world, with a population of about 21 million people, a very high rate of immigration and numerous illegal settlements. In order to meet the increasing water demand, successive governments have focused almost exclusively on supply management and engineering solutions, which have resulted in investments of hundreds of millions of USD and the construction of major infrastructure projects for interbasin water transfer. Environmental, economic and social policies associated with water management are mostly inadequate and insufficient, which is resulting in increasing deterioration in the environment, health and socioeconomic conditions of a population living in one of the largest urban agglomerations of the world. Surprisingly, however, no long-term strategies on demand-management, reuse, conservation, and improved water-management practices have been developed so far.     

1961～2000年瑞典地区极端降水的空间分析

本文分析了瑞典地区1961～2000年极端日降水量的空间尺度、区域变化和与之相关的天气类型.根据30km滞后距离计算的统计相关图估计年平均降水量、日降水量的99%分位值和平均年最大日雨量变化的空间尺度分别为100km、60～100km和40～70km.采用最大相似因子分析方法确定了82个站点极端降水量的区域相关.并发现有11个因子可以提供给最佳因子解决方案.极端事件发生时的天气类型是根据以逐日海平面气压为基础的客观系统划分的,并经过主观(包括锋面)修正.总体来看,极端降水事件的发生,63%在气旋类天气,32%在锋面类天气,3%在定向类天气,2%在反气旋类天气.然而,极端事件各种天气类型的发生频次不同地区之间有所不同.