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Oceanography has seen the recent development of many new toolsand techniques. The subfield of pelagic visual ecology in particularhas benefited from the development of more reliable, portable,and economic tools and techniques that can be taken to sea includingspectrometers, microspectrophotometery, electroretinography,and ultraviolet and polarization imaging systems. These advanceshave led to a relative wealth of data on the visual physiologyof pelagic species and on the optical properties of these speciesand their environment. These data, particularly in combinationwith computational methods, have tested long-standing hypothesesin pelagic ecology and led to new hypotheses and research directions.While the ability to study pelagic species still lags far behindwhat is possible in terrestrial and coastal environments, arenaissance may be developing in the study of the integrativebiology of pelagic species.  相似文献   

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Nicotinic acid adenine dinucleotide phosphate (NAADP) is the most potent calcium mobilizing messenger yet discovered. Its action has now been reported in a large number of cell types from a diverse array of organisms, and in some cases linked to the transduction of specific cellular stimuli. However, what is controversial is the nature of its target calcium release channel, as well as the subcellular localization of its receptor. Some have proposed that NAADP activates a novel calcium release channel distinct from the two major classes of channels known, the inositol trisphosphate receptors and ryanodine receptors. However, others have suggested that it acts in a novel way to regulate a known calcium release channel, the ryanodine receptor.  相似文献   

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Resistance to antibiotics and other antimicrobial compounds continues to increase. There are several possibilities for protection against pathogenic microorganisms, for instance, preparation of new vaccines against resistant bacterial strains, use of specific bacteriophages, and searching for new antibiotics. The antibiotic search includes: (1) looking for new antibiotics from nontraditional or less traditional sources, (2) sequencing microbial genomes with the aim of finding genes specifying biosynthesis of antibiotics, (3) analyzing DNA from the environment (metagenomics), (4) reexamining forgotten natural compounds and products of their transformations, and (5) investigating new antibiotic targets in pathogenic bacteria.  相似文献   

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Drones and machine learning‐based automated detection methods are being used by ecologists to conduct wildlife surveys with increasing frequency. When traditional survey methods have been evaluated, a range of factors have been found to influence detection probabilities, including individual differences among conspecific animals, which can thus introduce biases into survey counts. There has been no such evaluation of drone‐based surveys using automated detection in a natural setting. This is important to establish since any biases in counts made using these methods will need to be accounted for, to provide accurate data and improve decision‐making for threatened species. In this study, a rare opportunity to survey a ground‐truthed, individually marked population of 48 koalas in their natural habitat allowed for direct comparison of the factors impacting detection probability in both ground observation and drone surveys with manual and automated detection. We found that sex and host tree preferences impacted detection in ground surveys and in manual analysis of drone imagery with female koalas likely to be under‐represented, and koalas higher in taller trees detected less frequently when present. Tree species composition of a forest stand also impacted on detections. In contrast, none of these factors impacted on automated detection. This suggests that the combination of drone‐captured imagery and machine learning does not suffer from the same biases that affect conventional ground surveys. This provides further evidence that drones and machine learning are promising tools for gathering reliable detection data to better inform the management of threatened populations.  相似文献   

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Many diatom-based methods have been proposed in recent years. Besse-Lototskaya et al. (2011) compare some of those developed for assessing inorganic nutrients. However, they fail to address the two questions of greatest interest to those who wish to use such metrics to inform decision-making. These questions are: what is the role of diatom-based trophic metrics in environmental management in Europe in the twenty-first century and do these indices represent causal relationships with underlying pressure gradients? The present economic climate means that Member States of the European Union will look more critically at all methods for assessing freshwater quality and developers need to ensure that their methods are “fit-for-purpose”.  相似文献   

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Ethical concerns about biotechnology continue to be debated in the scientific and popular press. Ethical considerations have led to the development of frameworks within which biotechnology can be developed in socially acceptable and desirable ways: through legislation, the development of public-private collaborations, and regimes that safeguard consumer choice.  相似文献   

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Artificial insemination (AI) has a considerable cultural significance in addition to its economic and technical impact. This study is the first to examine the history of its application to pigs, and uses evidence provided directly by both the scientists involved in its development, and some of the farmers who were among the first to use it, in addition to archival and published sources, to show how the scientific studies of the 1950s evolved into a widely available commercial product by the 1980s. It describes the initial scientific work and quantifies the extent to which the technique was used at various points in time, showing that by 1990 nearly one half of UK pig herds were using AI for more than 25% of all services. It traces changes in the techniques employed and argues that these were the result of a multi-dimensional process of contemporaneous change. The various dimensions are identified firstly as authorities, meaning the people and organisations controlling the perception, administration, control, and so on, of the technique; secondly the discourses employed by the authorities; and thirdly the media by which the discourses were disseminated. Finally, it is suggested that this approach might be used more widely to examine the construction of other technologies.  相似文献   

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《Comptes Rendus Palevol》2007,6(3):231-233
There are two hypotheses to explain the emergence of the technical behaviour: (1) a sudden and fast appearance across the African continent; (2) a long period of emergence and consolidation before it began to spread. We defend this second hypothesis and suggest that the hominid project started around 3 Myr ago, with a ‘biofunctional’ stage. Later than 2.5 Myr, the ‘biomorphotechnical’ stage began (Mode 1), and, at around 1.7 Myr, another stage emerged and developed: the ‘biopotential’ stage (Mode 2). All these stages consist of a two-part process: innovation/emergence, and socialization/generalization of a technical mode.  相似文献   

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Purpose

This paper introduces the new EcoSpold data format for life cycle inventory (LCI).

Methods

A short historical retrospect on data formats in the life cycle assessment (LCA) field is given. The guiding principles for the revision and implementation are explained. Some technical basics of the data format are described, and changes to the previous data format are explained.

Results

The EcoSpold 2 data format caters for new requirements that have arisen in the LCA field in recent years.

Conclusions

The new data format is the basis for the Ecoinvent v3 database, but since it is an open data format, it is expected to be adopted by other LCI databases. Several new concepts used in the new EcoSpold 2 data format open the way for new possibilities for the LCA practitioners and to expand the application of the datasets in other fields beyond LCA (e.g., Material Flow Analysis, Energy Balancing).
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The skeleton: the new controller of male fertility?   总被引:1,自引:0,他引:1  
Smith LB  Saunders PT 《Cell》2011,144(5):642-643
Sex steroids, including testosterone, regulate the development and function of the male skeleton. Oury et al. (2011) identify a surprising new connection between the skeleton and the testis, which has implications for male fertility. They show that testosterone production in the testis is directly influenced by the bone-derived hormone osteocalcin.  相似文献   

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Genomic hybridization on whole genome arrays detects the presence or absence of similar DNA regions in sufficiently related microorganisms, allowing genome-wide comparison of their genetic contents. A whole genome array is based on a sequenced bacterial isolate, and is a collection of DNA probes fixed on a solid support. In a single hybridization experiment, the absence/presence status of all genes of the sequenced microbe in the queried isolate can be examined. The objective of this minireview is to summarize the past usage of DNA microarray technology for microbial strain characterizations, and to estimate its future utilization in epidemiological studies and molecular typing of bacterial pathogens. The studies reviewed here confirm the usefulness of microarray technology for the detection of genetic polymorphisms. However, the construction or purchase of DNA microarrays and the performance of strain to strain hybridization experiments are still prohibitively expensive for routine application. Future use of arrays in epidemiology is likely to depend on the development of more cost-effective protocols, more robust and simplified formats, and the adequate evaluation of their performance (efficacy) and convenience (efficiency) compared with other genotyping methods. It seems more likely that a more focused assay, concentrating on genomic regions of variability previously detected by genome-wide microarrays, will find broad application in routine bacterial epidemiology.  相似文献   

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