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861.
Behavioral Ecology and Sociobiology - Social complexity has been one of the recent emerging topics in the study of animal and human societies, but the concept remains both poorly defined and...  相似文献   
862.
Environmental Science and Pollution Research - Free ferulic acid (FA) is a natural compound with antioxidant properties which mitigates the negative effects of cold stress in sheep; however, its...  相似文献   
863.
The construction sector is responsible for around 28% of the total waste volume generated in Europe, which exceeds the amount of household waste. This has led to an increase of different research studies focusing on construction waste quantification. However, within the research studies made, packaging waste has been analyzed to a limited extent. This article focuses on the packaging waste stream generated in the construction sector. To this purpose current on-site waste packaging management has been assessed by monitoring ten Mediterranean residential building works. The findings of the experimental data collection revealed that the incentive measures implemented by the construction company to improve on-site waste sorting failed to achieve the intended purpose, showing low segregation ratios. Subsequently, through an analytical study the generation patterns for packaging waste are established, leading to the identification of the prevailing kinds of packaging and the products responsible for their generation. Results indicate that plastic waste generation maintains a constant trend throughout the whole construction process, while cardboard becomes predominant towards the end of the construction works with switches and sockets from the electricity stage. Understanding the production patterns of packaging waste will be beneficial for adapting waste management strategies to the identified patterns for the specific nature of packaging waste within the context of construction worksites.  相似文献   
864.
We have studied the effect of goat grazing on the shrub understory of a pine forest situated in a protected area (Doñana Natural Park). Along three years we have studied the changes in phytovolume, flammability, species richness and diversity in a grazed shrubland and in a control area not grazed by the goats. We studied also food preferences of the goats and the ability of the goats to disperse the seeds of the plants they eat. Goat grazing significantly reduced shrub biomass and flammability, decreasing the risk of forest fire. Goats selected the species they eat, changing the pattern of selection throughout the year. Grazing reduced shrub diversity, but did not affected species richness. The goats can also potentially disperse the seeds of some of the species they eat, since the seeds were able to pass through the goat’s gut and germinated afterwards. Goat grazing on scrub vegetation can be used as an effective tool for the control of shrubs in protected forest areas, without losing biodiversity.  相似文献   
865.
Lab-scale experiments were conducted to assess the impact of thermobarical treatment of cattle waste on anaerobic digestion. Treatment was at temperatures of 140–220 °C in 20 K steps for a 5-min duration. Methane yields could be increased by up to 58% at a treatment temperature of 180 °C. At 220 °C the abundance of inhibitors and other non-digestible substances led to lower methane yields than those obtained from untreated material. In an extended analysis it could be demonstrated that there is a functional correlation between the methane yields after 30 days and the formation rate and methane yield in the acceleration phase. It could be proved in a regression of these correlation values that the optimum treatment temperature is 164 °C and that the minimum treatment temperature should be above 115 °C.  相似文献   
866.
867.
Liver is very sensitive to environmental contaminants such as pesticides, it being the first target of toxicity of a substance. The objective of this study was to investigate the possible effects of the insecticide imidacloprid (IMI) on the liver of Oreochromis niloticus according concentrations used for growing sugarcane. A semi-quantitative analysis of histopathological alterations of IMI on liver was performed by light microscopy and cellular labeling of heat shock proteins (HSP70) by immunohistochemistry. The most common changes in liver at all concentrations of IMI were hydropic degeneration, pyknotic nuclei, and loss of cell limits. Steatosis and increased levels of HSP70 were detected in hepatocytes with the highest concentration of IMI. In conclusion, the tested concentrations of IMI induced histopathological changes in the liver of O. niloticus and active defence mechanisms to maintain the morphophysiological integrity of the liver. This insecticide has a toxicity potential for these fish, which is a non-target organism of its action.  相似文献   
868.
Behavioral Ecology and Sociobiology - Pre-copulatory sexual cannibalism (Pre-SC), where females attack and consume courting males, is considered an extreme case of sexual conflict. Different...  相似文献   
869.
870.
In this paper, we compare the populations of the Lusitanian toadfish Halobatrachus didactylus along the Portuguese shore, using a putative fragment of the mitochondrial control region and the first intron of the S7 ribosomal protein gene. This demersal species ranges from the tropical West African coast to the Iberian Peninsula and the Mediterranean, having its northern limit in the Tagus River. For the putative control region, a single haplotype occurs in all fish from Tagus and Sado (the location immediately to the south) with a clear increase in diversity to the South, peaking at Algarve (south Portugal). The data seem to point to a very recent Holocenic colonization of Tagus and Sado from the South (possibly Algarve). We suggest that even small oscillations in sea surface temperature (SST) may cause local extinctions and subsequent recolonizations in populations of thermophilic fish that are at the cold limit of their distributions.  相似文献   
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