Co-occurrence patterns of some small-bodied freshwater fishes in southwestern France: implications for fish conservation and environmental management

We assessed the influence of environmental variables (elevation, stream order, distance from source, catchment area, slope, stream width, and fish species richness) on the co-occurrence patterns of the minnow, the stone loach, and the gudgeon at the stream system scale. A total of 474 sites were classified according to the seven variables using the Self-Organizing Map (neural network), and three clusters were detected (k-means algorithm). The frequency of the various fish co-occurrence patterns was calculated for each cluster, and general linear modeling was used to specify the conditions that predict the occurrence of each species. Piedmont streams were more likely to support coexisting gudgeon and minnow populations because of higher probabilities of occurrence for both species. The higher co-occurrence frequency for the three species together in headwater streams resulted from lower occurrence frequencies in gudgeon and minnow. Focusing on areas that favor the co-occurrence of species may enhance the effectiveness of conservation projects.     

Home transport and wastage: environmentally relevant household activities in the life cycle of food

In environmental systems analysis of food production systems, the consumer phase (home transport, cooking, storing, and wastage) is an important contributor to the total life-cycle environmental impact. However, households are the least investigated part of the food chain. Information gathering about households involves difficulties; the number of households is large, and food-related activities are embedded in other household activities. In cooperation between researchers from environmental systems analysis and consumer research, Swedish households were surveyed by questionnaire, diary, and interviews. Data on home transport of food and wastage were collected. The average weekly driving distance was 28 to 63 km per household, depending on how trips made in conjunction with other errands are allocated. The wastage of prepared food ranged between 0 and 34% for different food categories, and wastage from storing between 0 and 164% (more food was discarded, e.g. by cleaning out a cupboard, than consumed). In both cases dairy products scored highest.     

Nestling size rank in the little egret (Egretta garzetta) influences subsequent breeding success of offspring

Few studies have investigated the long-term fitness consequences of nestling size hierarchies in altricial birds. In this study, we investigated whether or not the size rank order of siblings influences subsequent breeding success in the little egret, Egretta garzetta. From a marking program allowing individual recognition of wild birds, we obtained data on the breeding success of 56 pairs comprising individuals for which the size rank order was known. The breeding success in these pairs was positively influenced by the age of the marked bird but negatively affected by the laying date of the pair and the size rank order of the marked individual. There was also a significant difference between breeding colonies. We suggest two main hypotheses for a link between size rank order of individuals and their breeding success and we discuss our results in relation to current hypotheses on the adaptive value of hatching asynchrony. Received: 10 August 1998 / Accepted after revision: 13 December 1998     

Genetic mating system and timing of extra-pair fertilizations in the Kentish plover

It is still unclear why females in many bird species pursue extra-pair copulations. Current hypotheses focus mainly on indirect benefits such as obtaining particular good genes for their offspring or maximizing genetic compatibility between themselves and the father of their offspring. Supporting the latter, a recent study of shorebirds suggests that extra-pair matings may function to avoid the negative effects of genetic similarity between mates. Here, we further investigate genetic parentage in the Kentish plover, Charadrius alexandrinus, a shorebird with a highly variable social mating system. DNA fingerprinting revealed that most pairs were genetically monogamous: 7.9% of the broods (7/89) contained extra-pair young, comprising 3.9% of all chicks (9/229). These cases represented, however, three alternative reproductive behaviors: extra-pair paternity, quasi-parasitism (extra-pair maternity) and intraspecific brood parasitism. This is the first study showing the occurrence of all three behaviors in one shorebird species. We also found that extra-pair fertilizations (extra-pair paternity and quasi-parasitism) were more frequent later in the breeding season. There was no consistent relationship between genetic similarity of mates and laying date; the pattern, as well as the degree of genetic similarity, differed among breeding sites within the study population.Communicated by M. Webster     

Comparative study of carbonic anhydrase activity in waters among different geological eco-environments of Yangtze River basin and its ecological significance

This study provides the presence of carbonic anhydrase(CA) activity in waters of the Yangtze River basin, China, as well as the correlation of CA activity with HCO-3 concentration and CO_2 sink flux. Different degrees of CA activity could be detected in almost all of the water samples from different geological eco-environments in all four seasons. The CA activity of water samples from karst areas was significantly higher than from non-karst areas(PP3-concentration(r = 0.672, P2 sink flux(r = 0.602, P = 0.076) in karst areas. This suggests that CA in waters might have a promoting effect on carbon sinks for atmospheric CO_2 in karst river basins. In conditions of similar geological type, higher CA activity was generally detected in water samples taken from areas that exhibited better eco-environments, implying that the CA activity index of waters could be used as an indicator for monitoring ecological environments and protection of river basins. These findings suggest that the role of CA in waters in the karst carbon sink potential of river basins is worthy of further in-depth studies.     

Sulfated Polysaccharides from Tunisian Fish Skins: Antioxidant,DNA Damage Protective Effect and Antihypertensive Activities

Sulfated polysaccharides were isolated from two Tunisian fish skins grey triggerfish (Balistes capriscus) (GTSP) and smooth hound (Mustelus mustelus) (SHSP). Their chemical and physical characteristics were investigated. The Analysis of surface morphology by scanning electron microscopy of both sulfated polysaccharides displayed the same shape with netted structure. The antioxidant activities of GTSP and SHSP were evaluated using various in vitro antioxidant assays: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, reducing power, β-carotene bleaching inhibition assay (IC_{50 GTSP} = 0.5 mg mL^?1 and IC_{50 SHSP} = 0.6 mg mL^?1) and DNA nicking assay. Both sulfated polysaccharides exhibited good antioxidant activities. The sulfated polysaccharides showed strong angiotensin I-converting enzyme inhibitory activities (IC_{50 GTSP} = 0.16 mg mL^?1 and IC_{50 SHSP} = 0.18 mg mL^?1). These results revealed that GTSP and SHSP exhibited significant antihypertensive activities. Overall, the results indicated that grey triggerfish and smooth hound skins can be used to generate high value-added products, thus offering a valuable source of bioactive sulfated polysaccharides for application in wide range of biotechnological applications.     

Method for quantitative assessment of the domino effect in industrial sites

Accidents caused by the domino effect are the most destructive accidents related to industrial sites. The most typical primary incidents for a domino effect sequence are explosions (57%), followed by fires (43%) (Abdolhamidzadeh et al., 2010). These former can generate three escalation vectors (heat load, overpressure, and fragments), and may affect the surrounding equipments and/or facilities. If the affected targets are damaged, they may also explode and generate other threats to other surrounding facilities and so on. These chains of accidents may lead to catastrophic consequences and may affect not only the industrial sites, but also people, environment and economy. This paper presents a methodology for quantitative assessment of domino effects caused by fire and explosion on storage areas. The individual and societal risks are also estimated.