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201.
高通量测序技术极大地方便了深度考察不同种群中宿主相关微生物群的组成和功能。研究表明微生物在动物包括人类的健康和疾病发病中扮演着必要的角色。微生物已成为环境毒理学中新兴的重要研究主题。这是因为微生物在免疫系统中起着重要的交互的作用,同时在化学解毒中也有作用。污染物扰动肠道微生物,引起胃肠组织的病理生理变化,导致一系列系统效应,致使营养摄入变差和肠道发炎。本文检索了关于环境污染物对水生物种微生物影响的文献,重点关注了肠道微生物。我们强调了脊柱动物宿主中的一些已知的肠道上皮细胞的主要蛋白,这些均是化合物破坏的靶标,这些蛋白可以与微生物直接对话。我们提出了一个有害结局路径(adverse outcome pathway)的总体框架,将肠道生态失调作为有害效应终点事件的主要贡献因子。我们展示了两个案例研究,分别是(1)纳米材料;(2)碳氢化合物,我们参考了Deepwater Horizon港口的石油泄漏事件, 生态失调在案例中展示了微生物的考察如何改善有害结局的研究。最后,我们提出了一些策略以建立化合物诱导的肠道生态失调与有害结局的关联。我们通过实验建立了特定微生物与肠道生态失调的关联。对毒物与微生物关系的深入研究将成为改善动物及人类健康的重大突破。
精选自Ondrej Adamovsky, Amanda N. Buerger, Alexis M. Wormington, Naomi Ector, Robert J. Griffitt, Joseph H. Bisesi Jr., Christopher J. Martyniuk. The gut microbiome and aquatic toxicology: An emerging concept for environmental health. Environmental Toxicology and Chemistry,2018,37:2758-2775.
详情请见 https://doi.org/10.1002/etc.4249 相似文献
202.
Temperature and primary production (often linked to nutrient supply) are two of the few factors influencing species diversity and abundances across mesoscale gradients, while at smaller scales the habitat complexity offered by bioengineers is important. Previous studies have illustrated effects of upwelling and biogeography on intertidal bioengineers, but it is not known if these processes influence assemblages associated with those bioengineers in a similar way. We examined the habitat structure offered by two species of mussels and their associated fauna in five regions across 3000 km and three biogeographic provinces of the South African coast, replicating upwelling and non-upwelling areas within each region. Upwelling and region influenced the structure of mussel beds (the density and size of mussels). In contrast, upwelling did not influence mesoscale differences in composition, abundance, and numbers of species of crustaceans, mollusks, or polychaetes in mussel beds. Regardless of trophic level or mode of reproduction, mussel bed fauna were influenced only by region. Regional differences were strongly influenced by biogeography. The associated fauna was, however, also strongly correlated with the structure of the habitats created by mussels. Our results support the importance of upwelling to a critical ecosystem engineer, but show that these effects do not extend directly to the assemblages of associated fauna, which are more influenced by regional-scale effects and biogeography. We suggest that mesoscale patterns in the associated fauna of this bioengineered habitat are driven by the direct effects of biogeography, combined with the influence of biogeography and upwelling on mussel bed structure. 相似文献
203.
Nicole B. Richoux Sébastien Jaquemet Bo T. Bonnevie Yves Cherel Christopher D. McQuaid 《Marine Biology》2010,157(8):1755-1766
During chick-rearing, albatrosses can alternate between long foraging trips that provide the main source of food for the adults
and short foraging trips that they use to feed their young. This flexibility in foraging behaviour can lead to differences
in diet composition between adults and chicks and implies that they may be vulnerable in different ways to food shortages.
The trophic ecology of the Grey-headed albatross Thalassarche chrysostoma was investigated at the sub-Antarctic Prince Edward Islands during the chick-rearing period in April 2006 using a combination
of approaches. Diets of adults and chicks were assessed using stable isotope ratios and fatty acid (FA) profiles of blood
and/or stomach oils, in addition to stomach contents analysis. Fish from the family Macrouridae and cephalopods (particularly
the onychoteuthid Kondakovia longimana) were the primary prey, whereas crustaceans (krill Euphausia superba) represented a smaller proportion of the stomach contents. Stomach oil FA profiles contained more monounsaturated FA than
the profiles of plasma, which were richer in saturated FA and arachidonic acid (20:4n-6). There was also a distinct separation
of adults from chicks, with higher levels of monounsaturates in chick plasma, and higher saturated FA levels (particularly
16:0) in the adult plasma. Stable carbon isotope ratios of whole blood were similar in adults and chicks, whereas stable nitrogen
isotope ratios showed significant enrichment by >1‰ in chicks. The combined FA, stable isotopes and stomach contents analyses
suggest clear differences in diet quality between adults and chicks, with chicks feeding at a higher trophic position through
feeding more on highly nutritious fish and adults keeping much of the less nutritious zooplankton for themselves. 相似文献
204.
Increasing polybrominated diphenyl ether (PBDE) contamination in sediment cores from the inner Clyde Estuary,UK 总被引:1,自引:0,他引:1
Christopher H. Vane Yun-Juan Ma She-Jun Chen Bi-Xian Mai 《Environmental geochemistry and health》2010,32(1):13-21
The concentrations of 16 polybrominated diphenyl ether (PBDE) congeners in six short sediment cores from the Clyde Estuary
were determined by gas-chromatography mass-spectrometry. Total PBDE concentrations ranged from 1 to 2,645 μg/kg and the average
concentration was 287 μg/kg. BDE-209 was the main congener and varied from 1 to 2,337 μg/kg. Elevated total PBDE concentrations
were observed close to the sediment surface in the uppermost 10 cm of four of the six sediment cores. Comparison of the down
core PBDE profiles revealed that the increase was driven by the accumulation of deca-BDE. Although the deca-BDE mix was dominant,
the presence of lower molecular weight congeners BDE-47, BDE-99, BDE-183 and BDE-153 at most sediment intervals suggested
additional sources of penta-BDE and octa-BDE pollution. Changing PBDE source input was the major factor in influencing the
proportion of nona-brominated congeners, although other explanations such as post burial photo-debromination of BDE-209 cannot
be entirely discounted. A clear cascading to lower hepta-, hexa-, and penta-homologues was not found. The increase in total
PBDE concentrations and particularly the deca-BDE may possibly be ascribed to the use and subsequent disposal of electrical
appliances such as televisions and computers. In the Clyde sediments, the proportion of nona-brominated congeners was higher
than that reported for commercial mixtures. This might be due to changing sources of PBDEs or post burial photo-debromination
of BDE-209. 相似文献
205.
Christopher Brandl Alexander Mertens Christopher M. Schlick 《International journal of occupational safety and ergonomics》2013,19(1):110-117
In semi-trailer assembly, workers are exposed to several physical risk factors. Awkward working postures have not yet been investigated in semi-trailer assembly, although they are known to be a major risk factor for musculoskeletal disorders. We therefore conducted a comprehensive ergonomic analysis of working postures using the Ovako working posture analysing system (OWAS), with an individual sampling strategy. The postural load in semi-trailer assembly was assessed on the basis of 20,601 observations of 63 workers executing a representative set of nine work tasks. According to the OWAS, the postural load of various working postures and body part positions may have a harmful effect on the musculoskeletal system. We therefore give examples of corrective measures that could improve awkward working postures. Applying an individual sampling strategy was revealed to have advantages over a collective strategy, so this is recommended for future ergonomic analyses. 相似文献
206.
Eric D. Stein Matthew R. Cover A. Elizabeth Fetscher Clare O'Reilly Roxana Guardado Christopher W. Solek 《Journal of the American Water Resources Association》2013,49(4):780-792
Armoring of streambanks is a common management response to perceived threats to adjacent infrastructure from flooding or erosion. Despite their pervasiveness, effects of reach‐scale bank armoring have received less attention than those of channelization or watershed‐scale hydromodification. In this study, we explored mechanistic ecosystem responses to armoring by comparing conditions upstream, within, and downstream of six stream reaches with bank armoring in Southern California. Assessments were based on four common stream‐channel assessment methods: (1) traditional geomorphic measures, (2) the California Rapid Assessment Method for wetlands, (3) bioassessment with benthic macroinvertebrates, and (4) bioassessment with stream algae. Although physical responses varied among stream types (mountain, transitional, and lowland), armored segments generally had lower slopes, more and deeper pools and fewer riffles, and increased sediment deposition. Several armored segments exhibited channel incision and bank toe failure. All classes of biological indicators showed subtle, mechanistic responses to physical changes. However, extreme heterogeneity among sites, the presence of catchment‐scale disturbances, and low sample size made it difficult to ascribe observed patterns solely to channel armoring. The data suggest that species‐level or functional group‐level metrics may be more sensitive tools than integrative indices of biotic integrity to local‐scale effects. 相似文献
207.
Using Paleo Reconstructions to Improve Streamflow Forecast Lead Time in the Western United States 总被引:2,自引:0,他引:2
Christopher Carrier Ajay Kalra Sajjad Ahmad 《Journal of the American Water Resources Association》2013,49(6):1351-1366
In water stressed regions, water managers are exploring new horizons that would help in long‐range streamflow forecasts. Oceanic‐atmospheric oscillations have been shown to influence streamflow variability. In this study, long‐lead time streamflow forecasts are made using a multiclass kernel‐based data‐driven support vector machine (SVM) model. The extended streamflow records based on tree ring reconstructions were used to provide a longer time series data. Reconstructed data were used from 1658 to 1952 and the instrumental record was used from 1953 to 2007. Reconstructions for oceanic‐atmospheric oscillations included the El Niño‐Southern Oscillation, Pacific Decadal Oscillation, Atlantic Multidecadal Oscillation, and North Atlantic Oscillation. Streamflow forecasts using all four oscillations were made with one‐year to five‐year lead times for 21 gages in the western United States. This is the first study that uses both instrumental and reconstructed data of oscillations in SVM model to improve streamflow forecast lead time. SVM model was able to provide “satisfactory” to “very good” forecasts with one‐ to five‐year lead time for the selected gages. The use of all the oscillation indices helped in achieving better predictability compared to using individual oscillations. The SVM modeling results are better when compared with multiple linear regression model forecasts. The findings are statistical in nature and are expected to be useful for long‐term water resources planning and management. 相似文献
208.
A new assemblage of basal dichobunoid artiodactyls from the middle-Eocene Shanghuang fissure fillings includes the diacodexeid
Jiangsudon shanghuangensis gen. and sp. nov., a new species of the lantianine dichobunoid Elaschitotherium, Elaschitotherium crepaturus sp. nov., and an indeterminate suoid which is presently the earliest record of this clade. Diacodexeids are also represented
by two forms provisionally referred to cf. Diacodexis sp. and to an indeterminate Diacodexeidae, respectively. The occurrence of diacodexeids in Shanghuang contrasts with the
early and earliest middle-Eocene chronological range of the family in Europe and North America and suggests that the stratigraphic
range of the family in Asia extends up to the middle Eocene. This may reflect particular habitats in coastal China that may
have been relatively stable during the early and middle Eocene, thus preserving forest-dwelling artiodactyls that became extinct
in the other Holarctic regions. Compared to other supposedly coeval North American, European, and Asian faunas, the Shanghuang
mammalian assemblage is most similar to early Uintan faunas of North America but is also remarkable in recording forms close
to taxa that are characteristic of the Wasatchian and Bridgerian North American Land Mammal Ages. The Irdinmanhan age of the
Shanghuang fauna is supported by the mammalian assemblage recovered from the fissure D, but an Arshantan age cannot be completely
ruled out at this point. Although the Shanghuang assemblage is biased towards preservation of small components of the mammalian
fauna, the Shanghuang fauna provide an important and unique window into the Eocene diversity and early evolution of cetartiodactyls
in eastern Asia. 相似文献
209.
This study presents a method for assessing conservation opportunity on private land based on landholders' socio-economic, behavioral, and farm characteristics. These characteristics include age, gender, education, level of off-farm income, farm size, proportion of remnant native vegetation on-farm, and ecological value of native vegetation on-farm. A sample of landholders who own greater than 2 ha of land in the South Australian Murray-Darling Basin region were sent a mail-based survey about their values and preferences for environmental management (N = 659, 52% response). Cross-tabulations and ANOVA statistical analysis techniques were used to compare the socio-economic attributes across three landholder classes: disengaged, moderately engaged, and highly engaged in native vegetation planting. Results indicate that highly engaged landholders were more likely to be female, formally educated, hobby farmers who managed small parcels of land and have high off-farm incomes, whereas disengaged landholders held significantly stronger farming connections (more farming experience, family have lived on the farm for more generations). Spatial analysis revealed area-specific differences in conservation opportunity and conservation priority. In some areas, properties of high ecological value were managed by highly engaged landholders, but nearby properties of high value were managed by moderately engaged or disengaged landholders. Environmental managers therefore cannot assume areas of high conservation priority will be areas of high conservation opportunity. At the regional scale, the potential for revegetation seems most promising within the moderately engaged landholder group considering the vast amount of land managed by this group in areas of high ecological value, particularly within the less represented Mallee and Coorong and Rangelands sub-regions. We suggest that incentive schemes which purchase conservation need to be targeted at disengaged landholders; mentoring schemes led by commercial farmers highly engaged in native vegetation planting should be directed at moderately engaged landholders, and; awards programs which acknowledge conservation successes should be targeted at highly engaged landholders. 相似文献
210.
Benjamin M. Sleeter Tamara S. Wilson Christopher E. Soulard Jinxun Liu 《Environmental monitoring and assessment》2011,173(1-4):251-266
We present the first comprehensive multi-temporal analysis of land-cover change for California across its major ecological regions and primary land-cover types. Recently completed satellite-based estimates of land-cover and land-use change information for large portions of the United States allow for consistent measurement and comparison across heterogeneous landscapes. Landsat data were employed within a pure-panel stratified one-stage cluster sample to estimate and characterize land-cover change for 1973?C2000. Results indicate anthropogenic and natural disturbances, such as forest cutting and fire, were the dominant changes, followed by large fluctuations between agriculture and rangelands. Contrary to common perception, agriculture remained relatively stable over the 27-year period with an estimated loss of 1.0% of agricultural land. The largest net declines occurred in the grasslands/shrubs class at 5,131 km2 and forest class at 4,722 km2. Developed lands increased by 37.6%, composing an estimated 4.2% of the state??s land cover by 2000. 相似文献