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151.
Infanticide is widespread among mammals, is particularly common in primates, and has been shown to be an adaptive male strategy under certain conditions. Although no infanticides in wild orangutans have been reported to date, several authors have suggested that infanticide has been an important selection pressure influencing orangutan behavior and the evolution of orangutan social systems. In this paper, we critically assess this suggestion. We begin by investigating whether wild orangutans have been studied for a sufficiently long period that we might reasonably expect to have detected infanticide if it occurs. We consider whether orangutan females exhibit counterstrategies typically employed by other mammalian females. We also assess the hypothesis that orangutan females form special bonds with particular “protector males” to guard against infanticide. Lastly, we discuss socioecological reasons why orangutan males may not benefit from infanticide. We conclude that there is limited evidence for female counterstrategies and little support for the protector male hypothesis. Aspects of orangutan paternity certainty, lactational amenorrhea, and ranging behavior may explain why infanticide is not a strategy regularly employed by orangutan males on Sumatra or Borneo.  相似文献   
152.
Neighborhood attachment relates to one’s emotional connection to physical and social environments. Such bonds are critical for shaping how people interact with their local environments, connect with others and may be vital for fostering sustainable health behavior change related to nutrition and physical activity. Using data from a population-based survey of neighborhood environments and health in Denver, Colorado (n = 410 respondents; n = 45 block-groups) and hierarchical linear modeling techniques, we examined the relationship between objective and perceived neighborhood conditions (e.g., crime, physical incivilities, sense of safety), social processes (e.g., collective efficacy) and recreational gardening and neighborhood attachment. Results indicate length of residency, collective efficacy, and home and community garden participation are associated with neighborhood attachment. Further research is warranted to consider neighborhood attachment as an intervening mechanism through which gardens and other outdoor everyday places may influence health behavior change.  相似文献   
153.
Soil washing is a treatment process that can be used to remediate both organic and inorganic pollutants from contaminated soils, sludges, and sediments. A soil washing procedure was evaluated utilizing about 100 g samples of soil that had been field-contaminated with arsenic, chromium, copper, pentachlorophenol (PCP), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The highest level of mobilization/detoxification was achieved in three soil washes with a mixture of 0.1M [S,S]-ethyelnediaminedisuccinate ([S,S]-EDDS) and 2% Brij 98 at pH 9 with 20 min of ultrasonication treatment at room temperature. This combination mobilized 70% of arsenic, 75% of chromium, 80% of copper, 90% of PCP, and 79% of PCDDs and PCDFs, so that the decontaminated soil met the maximum acceptable concentrations of the generic C-level criteria regulated by the Ministère du Développement Durable, de l’Environnement et des Parcs for the Province of Québec, Canada.The organic pollutants were back-extracted from the aqueous suspension with hexane. Heavy metals were virtually completely precipitated from the aqueous washing suspension with Mg0 particles at room temperature. The PCP was detoxified by catalytic hydrodechlorination with a stream of 5% (v/v) H2-supercritical CO2 that transported the organosoluble fraction through a reaction chamber containing 2% Pd/γ-Al2O3.In toto, this soil washing procedure demonstrates that persistent organic pollutants and selected heavy metals can be co-extracted efficiently from a field-contaminated soil with three successive washes with the same soil washing solution containing [S,S]-EDDS and a non-ionic surfactant (Brij 98) in admixture. An industrial-scale ex situ soil washing procedure with a combination of a non-ionic surfactant and a complexing reagent seems to be a plausible remediation technique for this former wooden utility pole storage facility.  相似文献   
154.
In this paper we examine the optimal management of a renewable resource that is at risk from alien species invasion. The objective of this paper is to derive implications for optimal management of a resource when options exist for both preventing the arrival of an invasive species and mitigating the impact of that arrival. Uncertainty about the timing and nature of an invasion can have important implications for the choice of management strategy, and a key feature of this analysis is an explicit treatment of that uncertainty.  相似文献   
155.
Economic development, variation in weather patterns and natural disasters focus attention on the management of water resources. This paper reviews the literature on the development of mathematical programming models for water resource management under uncertainty between 2010 and 2017. A systematic search of the academic literature identified 448 journal articles on water resource management for examination. Bibliometric analysis is employed to investigate the methods that researchers are currently using to address this problem and to identify recent trends in research in the area. The research reveals that stochastic dynamic programming and multistage stochastic programming are the methods most commonly applied. Water resource allocation, climate change, water quality and agricultural irrigation are amongst the most frequently discussed topics in the literature. A more detailed examination of the literature on each of these topics is included. The findings suggest that there is a need for mathematical programming models of large-scale water systems that deal with uncertainty and multiobjectives in an effective and computationally efficient way.  相似文献   
156.
There is no certainty that adaptation to climate change is sustainable, and new approaches to assess current climate change adaptation trajectories are sorely needed. In this paper, we review the farmer-focused approaches (typical of vulnerability approaches) and agro-ecosystem-focused approaches (typical of resilience approaches). We propose that a combination of the two may be a better way to conceptualize sustainable adaptation to future climate change within an agro-ecological system. To test our hypothesis, we use the case study of Iran, a land that has shown both tremendous resilience and vulnerability in its agro-ecological system. We explore the changes that have occurred in the Iranian farming system and their implications for farmers’ resilience to climate change through an integrated lens combining vulnerability approaches and resilience approaches. During the previous five decades, we describe how Iranian peasants have become small farmers, the land tenure system has changed from a traditional landlord-sharecropping system to family farms, and the quantity and quality of the agro-ecological resources have changed considerably. Our integrative approach provides important insights for both research and policy. We show that combining the two approaches can have far-reaching implications for farmers’ adaptation to future climate change knowledge, policy, and practice since one approach aims to decrease farmers vulnerability and the other approach aims to build resilient agro-ecosystems.  相似文献   
157.
Dimethyldioctadecylammonium chloride (DODMAC, CAS No. 107-64-2) is the principal active component of Di(hydrogenated tallow alkyl) dimethylammonium chloride (DHTDMAC, CAS No. 61789-80-8), a cationic surfactant formerly used principally in laundry fabric softeners. After discharge to water, DODMAC partitions strongly to sediment, therefore the assessment of the effects of DODMAC to benthic organisms is essential in any risk assessment. Chronic toxicity studies were conducted with Lumbriculus variegatus (Oligochaete), Tubifex tubifex (Oligochaete) and Caenorhabditis elegans (Nematode). NOECs were greater than 5738, 1515 and 1351 mg/kg dw, respectively, even for sub-lethal effects. Measurement of the route of uptake of DODMAC by L. variegatus demonstrated the relative importance of uptake via ingestion (86%) compared with direct contact with the sediment and via pore water (14%). The overall tendency of DODMAC to bioaccumulate, however, was low with measured accumulation factors of 0.22 and 0.78 for L. variegatus and T. tubifex, respectively.  相似文献   
158.
Dyke PH  Sutton M  Wood D  Marshall J 《Chemosphere》2007,67(7):1275-1286
This paper reports on an intensive study into releases of polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated furans (PCDF) and polychlorinated biphenyls (PCB) from a diesel engine and the analysis of PCDD/F and PCB in crankcase lubricating oil. Experimental conditions were set and carefully controlled in order to maximize the possible impact of, and our ability to measure the effect of, changes in the levels of chlorine in the lubricant. Emissions to air were measured using modified EPA methods following the principles of the European EN 1948 standards. A series of 40 experimental runs were completed using three reference lubricants formulated to have three levels of chlorine present as a residual component (at levels of 12, 131 and 259 mg kg(-1) or ppm). The engine was run with and without the diesel oxidation catalyst. All lubricants were realistic oils and the use of unrealistic additives or doping of components - particularly chlorine - in the fuel and lubricant was carefully avoided. Analysis of fuel and lubricant (before and after testing) samples required strenuous attention to achieve acceptable recoveries and showed non-detectable levels of PCB and PCDD/F at a detection limit of around 1.5 ng I-TEQ kg(-1) (ppt), indistinguishable from the laboratory blank. The testing demonstrated the need for extreme care to be taken in developing measurement methods that are sufficiently sensitive for measuring chlorine content of fluids and PCDD/F in oils, the latter being particularly challenging. Mean emissions of PCDD/F with the diesel oxidation catalyst in place were 23 pg I-TEQ l(-1) of fuel and with the diesel oxidation catalyst removed 97 pg I-TEQ l(-1) of fuel. The results of this testing showed that the emissions of PCDD/F were greatly reduced by the presence of a diesel oxidation catalyst in the exhaust, a finding that has not been explicitly tested in previous work. They also show that emissions from the engine were not controlled by the level of chlorine in the lubricant and that emissions did not change in response to a much greater step change in the total chlorine entering the combustion chamber due to a change in the level of chlorine in the fuel. Emissions when the engine was configured with a diesel oxidation catalyst showed a consistent pattern that appears to be unique in the experience of the authors.  相似文献   
159.
This study evaluated the efficacy of a washing process with cyclodextrin in combination with ethylenediaminetetraacetate (EDTA) for the simultaneous mobilization of heavy metals and PCBs from a field contaminated soil. Ultrasonically aided mixing of the field contaminated soil with a combination of cyclodextrin solution (10%, w/v) and a sparing quantity (2 mmol) of EDTA, simultaneously mobilized appreciable quantities of PCBs and much of the analyte metal (Cd, Cr, Cu, Mn, Ni, Pb, Zn) burdens. Relative to the action of individual reagents, a combination of randomly methylated (RAMEB) or hydroxypropyl beta-cyclodextrin (HPCD) with EDTA did not alter the PCB extraction efficiency nor did the presence of cyclodextrin change the efficiency of mobilization of most heavy metals (Al, Cd, Cr, Fe, Mn, Ni, and Zn) but did increase the recovery of Cu and Pb modestly. Three sonication-washes with the same charge of reagents mobilized appreciable quantities of PCBs (40-76%) and quantitatively extracted the labile fraction of Cd, Cu, Mn, and Pb. RAMEB proved to be more efficient than HPCD for PCB extractions. Three successive extractions with a single charge of cyclodextrin mobilized almost as much PCB (RAMEB, 76%; HPCD, 40%) as did the companion extractions that used fresh reagents each time (RAMEB, 78%; HPCD, 42%). Collectively, these studies demonstrated that PCB compounds and selected heavy metals can be co-extracted efficiently from soil with three successive washes with the same washing suspension containing EDTA and cyclodextrin.  相似文献   
160.
Aguirre JD  Marshall DJ 《Ecology》2012,93(5):1134-1142
Reductions in genetic diversity can have widespread ecological consequences: populations with higher genetic diversity are more stable, productive and resistant to disturbance or disease than populations with lower genetic diversity. These ecological effects of genetic diversity differ from the more familiar evolutionary consequences of depleting genetic diversity, because ecological effects manifest within a single generation. If common, genetic diversity effects have the potential to change the way we view and manage populations, but our understanding of these effects is far from complete, and the role of genetic diversity in sexually reproducing animals remains unclear. Here, we examined the effects of genetic diversity in a sexually reproducing marine invertebrate in the field. We manipulated the genetic diversity of experimental populations and then measured individual survival, growth, and fecundity, as well as the size of offspring produced by individuals in high and low genetic diversity populations. Overall, we found greater genetic diversity increased performance across all metrics, and that complementarity effects drove the increased productivity of our high-diversity populations. Our results show that differences in genetic diversity among populations can have pervasive effects on population productivity within remarkably short periods of time.  相似文献   
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