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21.
Wave exposure and habitat complexity have been used to explain variations in the distribution patterns and behavior of many reef fishes. This study analyzed the influence of both factors on density and foraging activity, and the influence of group size on foraging in three species of the genus Halichoeres (Labridae) on tropical rocky shores. It was shown that initial phases (IP) and terminal phases (TP) Halichoeres, were influenced by wave exposure, although foraging in Halichoeres brasiliensis TP was not influenced by wave exposure. The IP in all three species were positively associated with rugosity and algal cover while the TP was positively associated with depth. Habitat complexity also influences foraging in these species. Group size influenced foraging activity, except in H. brasiliensis TP. We also found variations in microhabitat patches used for foraging between species and differences in the stomach contents between species and phases, showing that functional roles change in response to ontogenetic shifts.  相似文献   
22.
Wild polioviruses still remain endemic in three countries (Afghanistan, Pakistan, and Nigeria) and re-emergency of wild polio has been reported in previously polio-free countries. Environmental surveillance has been used as a supplementary tool in monitoring the circulation of wild poliovirus (PVs) and/or vaccine-derived PVs even in the absence of acute flaccid paralysis cases. This study aimed to monitor the presence of polioviruses in wastewater samples collected at one wastewater treatment plant located in the municipality of Rio de Janeiro, Brazil. From December 2011 to June 2012 and from September to December 2012, 31 samples were collected and processed. RD and L20B cell cultures were able to isolate PVs and non-polio enteroviruses in 27/31 samples. Polioviruses were isolated in eight samples (type 1 Sabin = 1, type 2 Sabin = 5, and type 3 Sabin = 2). Vaccine-derived polioviruses were not detected nor evidence of recombination with other PVs or non-polio enterovirus serotypes were observed among the isolates. The Sabin-related serotypes 2 and 3 presented nucleotide substitutions in positions associated with the neurovirulent phenotype at the 5′-UTR. Changes in important Amino acid residues at VP1 were also observed in the serotypes 2 and 3. Environmental surveillance has been used successfully in monitoring the circulation of PVs and non-polio enteroviruses and it is of crucial importance in the final stages of the WHO global polio eradication initiative. Our results show the continuous circulation of Sabin-like PVs and non-polio enteroviruses in the analyzed area during the study period.  相似文献   
23.
As resource conservation is an imperative for sustainable development, it is crucial to achieve a deeper understanding of the factors involved in people's decisions to recycle. This is even more so because the level of environmental concern is usually higher than the level of ecological behaviours. In this paper we take this fact as indicating that decision-making regarding conservation behaviours happens in the context of an internal debate where contradictory ideas are weighed up and the possibility of ambivalence arises. The main aim of this paper is therefore to explore how contradiction and ambivalence impact upon the attitudes, intentions and pro-ecological behaviours of the private sphere. The paper focuses specifically on the separation and deposition of metal cans, and compares the predictive capacity of beliefs, attitudes and intentions for two groups of respondents – one with a high and another with a low level of ambivalence, as assessed with a direct measure. The role of personal identity and the influence of structural constraints are also explored. Results demonstrate a clear moderating effect of experienced ambivalence, and show how beliefs, particularly negative ones, present a higher predictive capacity of the attitude in the high-ambivalence group, and personal identity plays a relevant role in predicting behaviour in both groups. We discuss the importance of pursuing the study of ambivalence when analysing decision-making in the conservation area.  相似文献   
24.
New data on the vapour pressures and aqueous solubility of 1,8-dichlorooctane and 1,8-dibromooctane are reported as a function of temperature between 20 °C and 80 °C and 1 °C and 40 °C, respectively. For the vapour pressures, a static method was used during the measurements which have an estimated uncertainty between 3% and 5%. The aqueous solubilities were determined using a dynamic saturation column method and the values are accurate to within ±10%. 1,8-Dichlorooctane is more volatile than 1,8-dibromooctane in the temperature range covered (psat varies from 3 to 250 Pa and from 0.53 to 62 Pa, respectively) and is also approximately three times more soluble in water (mole fraction solubilities at 25 °C of 5.95 × 10−7 and 1.92 × 10−7, respectively). A combination of the two sets of data allowed the calculation of the Henry’s law constants and the air water partition coefficients. A simple group contribution concept was used to rationalize the data obtained.  相似文献   
25.
R. Rosa  M. Nunes 《Marine Biology》2002,141(6):1001-1009
The objectives of the present study were to characterize the changes in the proximate chemical composition, lipid classes, fatty-acid profiles, glycogen and cholesterol contents of the muscle, ovary and hepatopancreas of Nephrops norvegicus (L.), during the reproduction cycle of this species. The gonadosomatic index increased significantly in May and June and during maturation, suggesting that spawning may start in late spring or summer. The hepatosomatic index also increased throughout the ovarian maturation, suggesting that the hepatopancreatic resources are not depleted. Positive correlations between lipid levels in the ovary and the gonadosomatic index (r=0.51, P<0.05) and the hepatopsomatic index (r=0.27, P<0.05) were found. In fact, ovarian lipid levels increased with maturation, but no concomitant decrease occurred in hepatopancreatic lipids. The muscle showed very low lipid levels (mainly polar lipids), presenting a significant increase during May and June (P<0.05). Higher proportions of neutral lipids, mainly triacylglycerols, were observed in the ovary and the hepatopancreas. Since both ovarian and hepatopancreatic cholesterol increased with maturation, the mobilization of hepatopancreatic cholesterol stores to build up ovarian cholesterol was not clear. On the other hand, protein and glycogen contents in the muscle, ovary and hepatopancreas did not vary as a function of ovary maturity stage. Among the various tissues analysed, the glycogen was mainly stored in the hepatopancreas and to a lesser extent in the muscle. In both ovary and hepatopancreas the major fatty acids were 16:0, 18:1(n-7), 18:1(n-9), 20:5(n-3) and 22:6(n-3), and significant increases (P<0.05) in the levels of monounsaturated and polyunsaturated fatty acids were observed in the ovary during sexual maturation, which indicates these compounds are the major sources of energy during embryonic and early larval development. It was evident that reproduction has profound effects upon the biochemistry of this species, because there are large associated energy costs, owing to the increase in biosynthetic work, which will support the lecithotrophic strategy of the embryos and first larval stages.  相似文献   
26.
This study was designed to monitor molinate losses in surface and underground waters during Ordram application in a rice field situated in central Portugal. Water samples were collected from different sites, before, during and about one month and a half after Ordram application. Molinate quantification was based on a solid-phase microextraction (SPME) method followed by gas chromatography with flame photometric detector (GC-FPD) analysis, and led to the conclusion that the herbicide was dissipated in the environment, reaching levels as high as 3.9 microgl(-1) in underground water and 15.8 microgl(-1) in the river receiving tail waters. The feasibility of the application of treatment methodologies based on adsorption or biodegradation as processes to remove molinate from real-world waters was assessed. These methods seem suitable to reduce molinate concentrations to values in the range of the legally recommended limits (<0.5 microgl(-1)).  相似文献   
27.
In this study, several columns of different lengths were filled with composite soils sampled from the field at corresponding depths and then loaded intermittently with influent of a high phosphorus concentration to evaluate phosphorus fate and transport in soil. The results indicate that the height of the mass transfer zone, solvent pore velocity, and soil's life expectancy for phosphorus removal increased with depth, while the retained phosphorus per kilogram of soil and the linear adsorption equilibrium coefficient, R, decreased with depth. An equation was developed to link liquid-phase phosphorus with solvent traveling time and soil depth. The results of X-ray diffraction and washout tests indicate that calcium-phosphorus precipitation and/or crystal growth occurred in the columns. The new protocol is useful for evaluation of phosphorus fate and transport in other subsurface systems, because it allows flexible adjustments in hydraulic loadings, feed solution, and sampling schemes.  相似文献   
28.
This paper attempts to examine whether information from valuation studies can help the design of policies adequate to reverse and halt the generally poor state of marine and coastal ecosystems of the Mediterranean and the Black Sea. Economic implications of managing coastal and marine environments are thus discussed by assessing the results of different valuation studies implemented in the area. Lessons and policy recommendations from existing literature are inferred to guide marine resources management decisions. One of our main findings is that there are extremely few published studies within the Mediterranean and Black Sea region which highlights the potential for future research on coastal and marine ecosystems ability to sustain different goods and services as a result of climate change and anthropogenic drivers in the area. However, results reveal that there are substantial positive economic values attached to marketed and non-marketed services provided by marine and coastal ecosystems that justify their sustainable use and management.  相似文献   
29.
Biological invasions occur worldwide, and have been the object of ecological and socio-economic research for decades. However, the manner in which different stakeholder groups identify the problems associated with invasive species and confront invasive species management under different policies remains poorly understood. In this study, we conducted an econometric analysis of the social factors influencing willingness to pay for invasive alien species management under two different regimes: eradication and prevention in the Doñana Natural Protected Area (SW Spain). Controlling for the participation of local residents, tourists and conservationists, email and face-to-face questionnaires were conducted. Results indicated that respondents were more willing to pay for eradication than prevention; and public support for invasive alien species management was influenced by an individual’s knowledge and perception of invasive alien species, active interest in nature, and socio-demographic attributes. We concluded that invasive alien species management research should confront the challenges to engage stakeholders and accept any tradeoffs necessary to modify different conservation policies to ensure effective management is implemented. Finally, our willingness to pay estimates suggest the Department of Environment of Andalusian Government has suitable social support to meet the budgetary expenditures required for invasive alien species plans and adequate resources to justify an increase in the invasive alien species management budget.  相似文献   
30.
Environmental assessment studies often evaluate the effectiveness of drainage culverts as habitat linkages for species, however, the efficiency of the sampling designs and the survey methods are not known. Our main goal was to estimate the most cost-effective monitoring method for sampling carnivore culvert using track-pads and video-surveillance. We estimated the most efficient (lower costs and high detection success) interval between visits (days) when using track-pads and also determined the advantages of using each method. In 2006, we selected two highways in southern Portugal and sampled 15 culverts over two 10-day sampling periods (spring and summer). Using the track-pad method, 90% of the animal tracks were detected using a 2-day interval between visits. We recorded a higher number of crossings for most species using video-surveillance (n = 129) when compared with the track-pad technique (n = 102); however, the detection ability using the video-surveillance method varied with type of structure and species. More crossings were detected in circular culverts (1 m and 1.5 m diameter) than in box culverts (2 m to 4 m width), likely because video cameras had a reduced vision coverage area. On the other hand, carnivore species with small feet such as the common genet Genetta genetta were detected less often using the track-pad surveying method. The cost-benefit analyzes shows that the track-pad technique is the most appropriate technique, but video-surveillance allows year-round surveys as well as the behavior response analyzes of species using crossing structures.  相似文献   
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