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451.
A geophysical seismic survey was conducted in the summer of 2001 off the northeastern coast of Sakhalin Island, Russia. The
area of seismic exploration was immediately adjacent to the Piltun feeding grounds of the endangered western gray whale (Eschrichtius robustus). This study investigates relative abundance, behavior, and movement patterns of gray whales in relation to occurrence and
proximity to the seismic survey by employing scan sampling, focal follow, and theodolite tracking methodologies. These data
were analyzed in relation to temporal, environmental, and seismic related variables to evaluate potential disturbance reactions
of gray whales to the seismic survey. The relative numbers of whales and pods recorded from five shore-based stations were
not significantly different during periods when seismic surveys were occurring compared to periods when no seismic surveys
were occurring and to the post-seismic period. Univariate analyses indicated no significant statistical correlation between
seismic survey variables and any of the eleven movement and behavior variables. Multiple regression analyses indicated that,
after accounting for temporal and environmental variables, 6 of 11 movement and behavior variables (linearity, acceleration,
mean direction, blows per surfacing, and surface-dive blow rate) were not significantly associated with seismic survey variables,
and 5 of 11 variables (leg speed, reorientation rate, distance-from-shore, blow interval, and dive time) were significantly
associated with seismic survey variables. In summary, after accounting for environmental variables, no correlation was found
between seismic survey variables and the linearity of whale movements, changes in whale swimming speed between theodolite
fixes, mean direction of whale movement, mean number of whale exhalations per minute at the surface, mean time at the surface,
and mean number of exhalations per minute during a whales surface-to-dive cycle. In contrast, at higher received sound energy
exposure levels, whales traveled faster, changed directions of movement less, were recorded further from shore, and stayed
under water longer between respirations. 相似文献
452.
Occurrence and distribution of novel botryococcene hydrocarbons in freshwater wetlands of the Florida Everglades 总被引:1,自引:0,他引:1
A high abundance of isoprenoid hydrocarbons, the botryococcenes, with carbon numbers from 32 to 34 were detected in the Florida Everglades freshwater wetlands. These compounds were present in varying amounts up to 106microg/gdw in periphyton, 278microg/gdw in floc, and 46microg/gdw in soils. Their structures were determined based on comparison to standards, interpretation of their mass spectra and those of their hydrogenation products, and comparison of Kovats indexes to those reported in the literature. A total of 26 cyclic and acyclic botryococcenes with 8 skeletons were identified, including those with fewer degrees of unsaturation, which are proposed as early diagenetic derivatives from the natural products. This is the first report that botryococcenes occur in the Everglades freshwater wetlands. Their potential biogenetic sources from green algae and cyanobacteria were examined, but neither contained botryococcenes. Thus, the source implication of botryococcenes in this ecosystem needs further study. 相似文献
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Schmidt G Pesch R Schröder W Conrad A Kolossa-Gehring M Feigenspan S Dobler L Wiesmüller GA Birke M Utermann J 《Environmental geochemistry and health》2011,33(4):399-408
This study aimed at statistically investigating the association between the internal exposure of children and young adults
to uranium (U) and epidemiologically relevant external determinants of exposure. The investigation was performed with data
from two studies within the framework of the German health-related environmental monitoring program: The German Environmental Survey for Children (GerES IV) conducted by the Federal Environment Agency (Umweltbundesamt) with data on 1,780 children 3–14 years of age and their home environment and the German Environmental Specimen Bank (ESB, section: human specimens) with data on 2,253 students 20–29 years of age. Both studies provided data on the U levels in human urine for all probands.
GerES IV furthermore provided an extensive environmental and demographic database on, e.g., U levels in drinking water. The
data from GerES IV and ESB were linked by GIS to spatially relevant exposure information, including background values of U
in stream sediments and in upper and lower soils, U levels in mosses and particulate matter in the lower atmosphere, precipitation
and elevation as well as forest density. Bivariate correlation analysis and two decision tree models showed moderate but significant
associations between U in human urine and U levels in drinking water, stream sediments and upper and lower soils. Future investigations
considering additional epidemiologically relevant data sets may differentiate the results. Furthermore, the sample design
of future environmental epidemiology studies should take the spatial evaluation of the data into greater account. 相似文献
458.
Müller Irene Althof Nadine Hoffmann Bernd Klaus Christine Schilling-Loeffler Katja Falkenhagen Alexander Johne Reimar 《Food and environmental virology》2023,15(1):32-42
Food and Environmental Virology - Infection with the tick-borne encephalitis virus (TBEV) can cause meningitis, meningoencephalitis and myelitis in humans. TBEV is an enveloped RNA virus of the... 相似文献
459.
The aim of this study was to investigate the effects of the implementation process to new technologies [e.g. drawing board/computer-aided design (CAD), microfiche/electronic data processing] on the employees concerned. Since the emphasis of the study lay in the intrinsic relationship of the implementation process with stress reactions, the parameters were measured at the place of work in a longitudinal design. Employees (n = 279) in seven companies (work fields: CAD, clerical work, telephone information desk) were tested three times — two months prior to, during, and 12 months after implementation. Aspects of strain and satisfaction were taken into account at each measurement phase. A special test-instrument was designed to describe the ’style of implementation‘ (manner in which implementation took place) particular to each company. The level of strain was found to increase during the implementation process. The amount of this increase was found to correlate with the company's style of implementation as well as with the type of the individual's work activity. The highest levels were found among those employees little included in the implementation process and those whose work is described as monotonous. 相似文献
460.