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1.
Through a systems approach indicators are shown to have the nature of variables, adopting different values or states, while other associated terms allude to special meanings assigned to specific values of the indicators. Practical implications are discussed. The concept of situational indicators of sustainability is introduced, representing a non-numerical function of both “pressures” or “driving forces” and “state” variables. A cost-effective multi-tiered approach to situational indicators is proposed. The concept of situational indicators is shown to be a particular case of indicators of systems behavior. A general systems formulation of the problem of sustainability highlights the importance of indicators of systems behavior and the central role of models in their definition.  相似文献   
2.
This paper analyses survey results of the effectiveness of information campaigns to promote energy efficiency among residential consumers in Brazil. The survey found that consumers have a relatively good knowledge of conservation measures to improve electricity usage. Nevertheless, other approaches are needed to promote energy conservation in the household sector.  相似文献   
3.

Purpose  

The aims of this paper were to quantify the heavy metals (HM) in the air of different sites in Rio de Janeiro (RJ) and Salvador (SA) using Tillandsia usneoides (Bromeliaceae) as a biomonitor, and to study the morphology and elemental composition of the air particulate matter (PM) retained on the Tillandsia surface.  相似文献   
4.
This study uses the process simulator ASPEN Plus® and Life Cycle Assessment (LCA) to compare three process design alternatives for biodiesel production from waste vegetable oils that are: the conventional alkali-catalyzed process including a free fatty acids (FFAs) pre-treatment, the acid-catalyzed process, and the supercritical methanol process using propane as co-solvent. Results show that the supercritical methanol process using propane as co-solvent is the most environmentally favorable alternative. Its smaller steam consumption in comparison with the other process design alternatives leads to a lower contribution to the potential environmental impacts (PEI’s). The acid-catalyzed process generally shows the highest PEI’s, in particular due to the high energy requirements associated with methanol recovery operations.  相似文献   
5.
Optimal foraging theory assumes that a forager can adequately assess the quality of its prey and predicts that parents feed their young low-quality foods only when suffering unpredicted reductions in their ability to provision. Wildland Florida scrub-jays feed their young exclusively arthropods, but suburban parents include human-provided foods in the nestling diet, with possible costs in terms of reduced growth and survival. We tested experimentally whether parents feed human-provided foods, given the apparent costs, because: 1) they do not discriminate between food types, 2) they switch to low-quality, abundant foods when natural food availability in the environment is low, or 3) they switch when the time needed to obtain natural food is high. Parents discriminated between natural and human-provided foods by showing a preference for natural foods when rearing young. When the handling time of natural foods was increased experimentally, parents in the suburban and wildland habitats switched to human-provided foods. Supplementation with natural foods increased preference for this food in both habitats. Suburban parents chose more natural foods than wildland parents, suggesting that they have a greater preference for natural foods. Regardless of preferences demonstrated at feeders, parents in both the suburbs and wildlands delivered mostly natural foods to nestlings, independent of natural food availability. Nonetheless, natural foods are likely to be scarcer in the environment than in our experimental tests. Because natural food availability is lower in the suburbs than in the wildland habitat, parents in the suburbs may be forced to switch to human-provided foods when feeding nestlings.  相似文献   
6.
Studies of animal breeding dispersal have often focused on possible causes, whereas its adaptive significance has received less attention. Using an information-theoretic approach, we assessed predictions of four hypotheses relating to causes and consequences of breeding dispersal in a migratory passerine, the red-backed shrike Lanius collurio. As predicted by the reproductive performance hypothesis, probability of breeding dispersal in females (though not in males) decreased with increasing annual average number of fledglings produced in the past year, but there was no association with conspecific reproductive performance in either sex. The site choice hypothesis, stating that individuals disperse to improve breeding site quality, received support in males only, as dispersal probability was positively associated to a measure indicating low territory quality. The social constraints hypothesis, referring to dispersal in relation to intraspecific interactions, received little support in either sex. The predation risk hypothesis was hardly supported either. Consequences of dispersal were marginal in both sexes because neither fledgling production in females, nor territory quality in males improved after dispersal. In addition, males settled on territories closer to the forest edge than those occupied predispersal, which is opposite to the prediction of the predation risk hypothesis. We conclude that own reproductive success was the major factor determining dispersal behavior in females, whereas territory quality and possibly predation risk were most important in males. Overall, breeding dispersal appeared not to be adaptive in this dense population inhabiting an optimal habitat.  相似文献   
7.
Plasma testosterone levels were evaluated, by validating and using a commercially available testosterone enzyme immunoassay (EIA) as an indicator of the sex of immature loggerhead turtles (Caretta caretta) recovered along the western coast of the central Adriatic Sea between November 2011 and February 2012. Testosterone levels were measured in blood samples collected from 28 immature turtles kept in short-term maintenance at the Fondazione Cetacea Rescue Centre (Italy). Overall, plasma testosterone ranged between 229.3 and 2628.6 pg ml?1, suggesting that the EIA procedure is effective for determining androgen titers in immature loggerhead sea turtles. Analysis of the obtained data indicates an unbiased sex ratio supporting previous studies of juvenile loggerhead turtle sex ratios in the Mediterranean Sea. The present work can be considered a starting point for augmenting knowledge on the dynamics of juvenile loggerhead aggregations increasingly found in the northern-central Adriatic Sea and for promoting local management for conservation actions.  相似文献   
8.
This article discusses the current problems and issues associated with the implementation of a National System of Marine Protected Areas in Brazil. MPA managers and higher governmental level authorities were interviewed about their perceptions of the implementation of a national MPA strategy and the recent changes in the institutional arrangement of government marine conservation agencies. Interviewees’ narratives were generally pessimistic and the National System was perceived as weak, with few recognizable marine conservation outcomes on the ground. The following major flaws were identified: poor inter-institutional coordination of coastal and ocean governance; institutional crisis faced by the national government marine conservation agency; poor management within individual MPAs; problems with regional networks of marine protected areas; an overly bureaucratic management and administrative system; financial shortages creating structural problems and a disconnect between MPA policy and its delivery. Furthermore, a lack of professional motivation and a pessimistic atmosphere was encountered during many interviews, a malaise which we believe affects how the entire system is able to respond to crises. Our findings highlight the need for a better understanding of the role of ‘leadership’ in the performance of socio-ecological systems (such as MPA networks), more effective official evaluation mechanisms, more localized audits of (and reforms if necessary to) Brazil’s federal biodiversity conservation agency (ICMBio), and the need for political measures to promote state leadership and support. Continuing to focus on the designation of more MPAs whilst not fully addressing these issues will achieve little beyond fulfilling, on paper, Brazil’s international marine biodiversity commitments.  相似文献   
9.
Factorial design plan was experimented in Perna perna in order to find out the contribution of day exposure, Cd and Cu concentrations in water, and their interactions on metallothioneins (MT), Cd, and Cu (the dependent measured variables) in the gills. The picture obtained is more adequate than by studying the factor effect separately. Compared with the control group, the MT concentration after 22?days exposure period in the mixture of 100?μg/mL Cu and Cd is increased almost two times, showing that P. perna might be used as a biomonitor. Cd showed stronger effect than Cu on MT inducing.  相似文献   
10.
The chemical form of Ag in the livers of five species of marine mammals was examined using X-ray absorption fine structure (XAFS) and X-ray fluorescence (XRF) spectroscopies. The XAFS analysis suggested that Ag(2)Se was present in the livers of the Franciscana dolphin (Pontoporia blainvillei), Dall's porpoise (Phocoenoides dalli), and Baird's beaked whale (Berardius bairdii), whereas Ag(2)S was present in the livers of the striped dolphin (Stenella coeruleoalba) and pygmy killer whale (Feresa attenuata). XRF spectroscopy results revealed that the distribution patterns of Ag and Se in a thin section of the liver of the Franciscana dolphin were the same; this also implied that Ag was associated with Se in the liver. Thus, the interaction of Ag with Se or S may offer significant protection against the toxicity of Ag in marine mammals. The formation of either Ag(2)Se or Ag(2)S might depend on the Hg levels in the liver. Ag(2)Se was observed in liver samples with relatively high Ag/Hg ratio, whereas liver samples with low Ag/Hg ratio contained Ag(2)S.  相似文献   
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