Sensitivity of streamflow and microbial water quality to future climate and land use change in the West of Ireland

Regional Environmental Change - This study applied catchment modeling to examine the potential effects of climate change and future land management variations on streamflow and microbial transport...     

高价离子还原菌还原机理及研究进展

高价离子还原菌普遍存在于自然环境中,它们在环境的原位修复中起着非常重要的作用。本文主要介绍了三种典型的高价离子还原菌：异化Fe（III）还原菌（IRB）、硝酸盐还原菌及硫酸盐还原菌（SRB）,分别以Fe3＋、N03-和SO4^2-为电子受体,以有机物作为电子供体,在将高价离子还原的同时,达到对污染环境的修复作用。文章综述了此类细菌的特性、作用机理、影响因素以及在国内外实际中的应用,分析了异化Fe（III）还原菌、硝酸盐还原菌及硫酸盐还原菌的异同点,并对该类细菌在环境污染治理中的发展趋势进行了评述。     

Virological Quality of Irrigation Water in Leafy Green Vegetables and Berry Fruits Production Chains

This study condenses data acquired during investigations of the virological quality of irrigation water used in production of fresh produce. One hundred and eight samples of irrigation water were collected from five berry fruit farms in Finland (1), the Czech Republic (1), Serbia (2), and Poland (1), and sixty-one samples were collected from three leafy green vegetable farms in Poland, Serbia, and Greece. Samples were analyzed for index viruses of human or animal fecal contamination (human and porcine adenoviruses, and bovine polyoma viruses), and human pathogenic viruses (hepatitis A virus, hepatitis E virus, and noroviruses GI/GII). Both index and pathogenic viruses were found in irrigation water samples from the leafy green vegetables production chain. The data on the presence of index viruses indicated that the highest percentage of fecal contamination was of human origin (28.1 %, 18/64), followed by that of porcine (15.4 %, 6/39) and bovine (5.1 %, 2/39) origins. Hepatitis E virus (5 %, 1/20) and noroviruses GII (14.3 %, 4/28) were also detected. Samples from berry fruit production were also positive for both index and pathogenic viruses. The highest percentage of fecal contamination was of human origin (8.3 %, 9/108), followed by that of porcine, 4.5 % (4/89) and bovine, 1.1 % (1/89) origins. Norovirus GII (3.6 %, 2/56) was also detected. These data demonstrate that irrigation water used in primary production is an important vehicle of viral contamination for fresh produce, and thus is a critical control point which should be integrated into food safety management systems for viruses. The recommendations of Codex Alimentarius, as well as regulations on the use of water of appropriate quality for irrigation purposes, should be followed.     

Wild elephant (Loxodonta africana) breeding herds respond to artificially transmitted seismic stimuli

Seismic communication is known to be utilized in insects, amphibians, reptiles, and small mammals, but its use has not yet been documented in large mammals. Elephants produce low-frequency vocalizations, and these vocalizations have seismic components that propagate in the ground, but it has not yet been demonstrated that elephants can detect or interpret these seismic signals. In this study, we played back seismic replicates of elephant alarm vocalizations to herds of wild African elephants in their natural environment and observed significant behavioral changes indicating that they had detected these signals. Seismic communication may provide an important complement to existing communication modes used by elephants. Seismic sensitivity may also provide elephants with an additional modality for sensing important environmental cues such as changes in weather patterns or seismic disturbances.     

Context-dependent genetic benefits of extra-pair mate choice in a socially monogamous passerine

Extra-pair paternity is common in socially monogamous passerines; however, despite considerable research attention, consistent differences in fitness between within-pair offspring (WPO) and extra-pair offspring (EPO) have not been demonstrated. Recent evidence indicates that differences between maternal half-siblings may depend on environmental conditions, but it is unclear whether the influence of paternal genetic contribution should be most apparent under comparatively poor or favourable conditions. We compared phenotypic characteristics of WPO and EPO in 30 mixed-paternity broods of the tree swallow (Tachycineta bicolor) in relation to experimentally increased nest temperature (n = 13 heated nests; 17 control nests) and natural abundance of haematophagous parasites (Protocalliphora spp.). This allowed us to test the hypothesis that genetic benefits of extra-pair mating are environment dependent. EPO grew their ninth primary feathers faster than WPO regardless of nest temperature or parasite load and had significantly longer ninth primary feathers at fledging when parasite abundance was low, and when they were positioned early in the hatching sequence relative to WPO. In contrast, WPO under similar conditions did not differ from EPO in any phenotypic trait measured. These results indicate that the fitness benefits of extra-pair mating are likely to be context dependent, and that genetic effects on some phenotypic traits may be more apparent when conditions are relatively favourable.     

Intra-specific interactions influence egg composition in the lesser black-backed gull (Larus fuscus)

Egg composition, which is under maternal control, can have a profound effect on offspring fitness. The presence of maternal testosterone and carotenoids in avian egg yolk, for example, is thought to enhance the development and competitive ability of the offspring and protect the hatching and growing chick against oxidative stress. Egg quality often differs between females and such variation can be due to differences in maternal social environment, e.g. breeding density. However, this is confounded by the possibility that the quality of individuals breeding in high- or low-density areas may vary. We tested if maternal social environment influences egg composition in a colonial seabird, the lesser black-backed gull (Larus fuscus). To control for confounding effects of female quality, we experimentally manipulated maternal social environment during egg formation. We increased the frequency of intra-specific interactions (i.e. aggressive encounters with conspecifics other than nest mates) in which the females were involved, by placing an elevated platform in their territory. Females that took part in more intra-specific interactions produced a heavier last egg, but the yolk testosterone concentration in eggs laid by control and experimental females did not differ. Differences in yolk testosterone concentration in relation to embryo sex were found neither in the control nor in the experimental group. In contrast, within the control group, eggs with a male embryo contained more carotenoids than eggs with a female embryo. Moreover, experimental females that had been involved in more intra-specific interactions produced female eggs with higher carotenoid levels compared to female eggs of control birds. An experimental increase in carotenoid levels was not observed in eggs containing a male embryo. Our results suggest that intra-specific interactions experienced by female birds during egg formation can influence conditions for embryonic development.Communicated by J. Graves