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61.
Crone EE  Schultz CB 《Ecology》2008,89(7):2061-2067
Understanding movement in heterogeneous environments is central to predicting how landscape changes affect animal populations. Several recent studies point out an intriguing and distinctive looping behavior by butterflies at habitat patch edges and hypothesize that this behavior requires a new framework for analyzing animal movement. We show that this looping behavior could be caused by a longstanding movement model, biased correlated random walk, with bias toward habitat patches. The ability of this longstanding model to explain recent observations reinforces the point that butterflies respond to habitat heterogeneity and do not move randomly through heterogeneous environments. We discuss the implications of different movement models for predicting butterfly responses to landscape change, and our rationale for retaining longstanding movement models, rather than developing new modeling frameworks for looping behavior at patch edges.  相似文献   
62.
The objective of this work was to provide updated information on the development of the potential impact of heavy metal containing batteries on municipal waste and battery recycling processes following transposition of the new EU Batteries Directive 2006/66/EC. A representative sample of 146 different types of commercially available dry and button cells as well as lithium-ion accumulators for mobile phones were analysed for their mercury (Hg)-, cadmium (Cd)- and lead (Pb)-contents. The methods used for preparing the cells and analysing the heavy metals Hg, Cd, and Pb were either developed during a former study or newly developed. Several batteries contained higher mass fractions of mercury or cadmium than the EU limits. Only half of the batteries with mercury and/or lead fractions above the marking thresholds were labelled. Alkaline–manganese mono-cells and Li-ion accumulators, on average, contained the lowest heavy metal concentrations, while zinc–carbon batteries, on average, contained the highest levels.  相似文献   
63.
64.

This study was conducted to evaluate the microbiological quality of a mangrove estuary in the Vitória Bay region, Espírito Santo, Brazil. We analyzed the presence and concentration of enteric viruses and thermotolerant coliforms in water, mussels (Mytella charruana and Mytella guyanensis), and oysters (Crassostrea rhizophorae), collected over a 13-month period. Human adenovirus, rotavirus A (RVA), and norovirus genogroup II were analyzed by quantitative PCR. The highest viral load was found in RVA-positive samples with a concentration of 3.0 × 104 genome copies (GC) L−1 in water samples and 1.3 × 105 GC g−1 in bivalves. RVA was the most prevalent virus in all matrices. Thermotolerant coliforms were quantified as colony-forming units (CFU) by the membrane filtration method. The concentration of these bacteria in water was in accordance with the Brazilian standard for recreational waters (< 250 CFU 100 mL−1) during most of the monitoring period (12 out of 13 months). However, thermotolerant coliform concentrations of 3.0, 3.1, and 2.6 log CFU 100 g−1 were detected in M. charruana, M. guyanensis, and C. rhizophorae, respectively. The presence of human-specific viruses in water and bivalves reflects the strong anthropogenic impact on the mangrove and serves as an early warning of waterborne and foodborne disease outbreaks resulting from the consumption of shellfish and the practice of water recreational activities in the region.

  相似文献   
65.
The production of polyhydroxyalkanoates(PHA) from wastewaters using microbial mixed cultures(MMC) has been attracting increased interest because of PHA's biodegradability characteristics. Production of PHA by an MMC enriched with PHA-accumulating bacteria was compared using anaerobically treated and acidified brewery wastewaters under various feeding strategies, namely pulse and batch feed addition. To obtain an enriched MMC, a sequencing batch reactor was inoculated with activated sludge fed with acetate and subjected to aerobic dynamic feeding. The enriched MMC was able to accumulate PHA up to 72.6% of cell dry weight(CDW) with pulse addition of acetate controlled by the dissolved oxygen(DO) concentration in the reactor. In a batch accumulation experiment with acetate,the PHA content achieved(28.5% CDW) was less than that of the pulse feeding strategy with the same amount of acetate(~2000 mg C/L). Using anaerobically treated and acidified brewery wastewater fed in pulses, the maximum PHA accumulated by the enriched MMC was similar for both wastewaters(45% CDW), in spite of the higher volatile fatty acid concentration in acidified brewery wastewater. The pulse feed addition controlled by the DO concentration was difficult to implement for wastewater as compared to acetate because the difference in DO concentration between substrate availability and depletion was low. For the batch addition of acidified wastewater, a slightly lower PHA content(39%CDW) was obtained. These results show that both brewery wastewaters can be utilized for PHA production with a similar maximum PHA storage capacity.  相似文献   
66.
Ureases are nickel-dependent enzymes which catalyze the hydrolysis of urea to ammonia and carbamate. Despite the apparent wealth of data on ureases, many crucial aspects regarding these enzymes are still unknown, or constitute matter for ongoing debates. One of these is most certainly their structural organization: ureases from plants and fungi have a single unit, while bacterial and archaean ones have three-chained structures. However, the primitive state of these proteins — single- or three-chained — is yet unknown, despite many efforts in the field. Through phylogenetic inference using three different datasets and two different algorithms, we were able to observe chain number transitions displayed in a 3-to-1 fashion. Our results imply that the ancestral state for ureases is the three-chained organization, with single-chained ureases deriving from them. The two-chained variants are not evolutionary intermediates. A fusion process, different from those already studied, may explain this structural transition.  相似文献   
67.
Summary The effect of multiple mating on the average genetic relatedness within socially interacting sib groups was studied in the imported willow leaf beetle. Using an electrophoretically determined genetic marker, it was demonstrated that between 49 and 96% of wild caught females produce egg clutches expressing multiple sires. Following theoretical predictions of Wade (1982), this information was used to estimate the harmonic mean number of sires per family and then the average relatedness within families. Average relatedness was estimated to be 0.38. An alternate form of data analysis suggested by Pamilo and Crozier (1982) did not require any knowledge of paternity and resulted in a slightly higher estimate of relatedness, 0.44.  相似文献   
68.
The Algal Growth Potential Test has been an accepted standard test for measuring the bioavailability of nutrients in water bodies. A shortened seven day test has been developed, tested, and shown to have a strong correlation relationship with algal tests grown to maximum dry weight yields. The new test will save time in processing the samples and processing of test data.  相似文献   
69.
Herbicides of the chlorinated phenoxyalkanoic acid group like 2,4-D, 2,4-DP and MCPP, belong to the most commonly used pesticides. This is also true for the Land Brandenburg. Therefore, this substance group was integrated in the current state monitoring programme for ground and surface water quality. Starting in 2001, the analysis was carried out complying with DIN 38407-20 by gas chromatography and mass spectrometric detection after enrichment with solid phase extraction and following derivatization with diazomethane-forming methyl esters. Quantifying 2,4-D considering selected ions in a surface water sample from the river Oder, a remarkable peak pattern was observed. A second peak with identical spectrum was found about 0.7 minutes earlier than the 2,4-D calibrated peak. Its intensity suggested a concentration 10–20 fold higher than the 2,4-D level. This unknown peak was identified as 2,6-D which is a structure isomer of the herbicide 2,4-D. This substance has not been described in literature or chemical substance databases known to us yet. Structure isomers have been found in other samples too. We suppose that the chlorinated phenoxyalkanoic acids chlorinated in the 6-position of the phenyl ring are formed as a technical by-product and show a higher persistance than the commonly known agents.  相似文献   
70.
This paper proposes the concept of cumulative eco-intensity with which environmental or sustainability indicators are related to the added value of economic activities. The intensities are passed on recursively from supplier to supplier and thus make it possible to include upstream and downstream effects along the supply and waste disposal chain. The process is applied to whole companies and (by contrast with LCA) not to individual products. At comparatively low expenditure for the individual companies, it allows vertical comparisons along the value-adding chain and horizontal comparisons among companies or production locations. This provides a decision-making aid for a company seeking to fulfil its ecological or sustainability responsibility in the entire production and supply chains.  相似文献   
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