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361.
Oettl D Sturm PJ Pretterhofer G Bacher M Rodler J Almbauer RA 《Journal of the Air & Waste Management Association (1995)》2003,53(10):1233-1240
Transit traffic through the Austrian Alps is of major concern in government policy. Pollutant burdens resulting from such traffic are discussed widely in Austrian politics and have already led to measures to restrict traffic on transit routes. In the course of an environmental assessment study, comprehensive measurements were performed. These included air quality observations using passive samplers, a differential optical absorption spectroscopy system, a mobile and a fixed air quality monitoring station, and meteorological observations. As was evident from several previous studies, dispersion modeling in such areas of complex terrain and, moreover, with frequent calm wind conditions, is difficult to handle. Further, in the case presented here, different pollutant sources had to be treated simultaneously (e.g., road networks, exhaust chimneys from road tunnels, and road tunnel portals). No appropriate system for modeling all these factors has so far appeared in the literature. A prognostic wind field model coupled with a Lagrangian dispersion model is thus presented here and is designed to treat all these factors. A comparison of the modeling system with results from passive samplers and from a fixed air quality monitoring station proved the ability of the model to provide reasonable figures for concentration distributions along the A10. 相似文献
362.
363.
By chance, we had the opportunity to make serial sonographic observations of the extrusion of meconium in a case of meconium peritonitis. Inflammation leads to exudative processes and production of fluid (ascites) in the fetal abdomen. Sonography at that stage of the disease may lead to a misdiagnosis such as ‘fetal ascites’ or ‘non-immune hydrops’. After bowel perforation and extrusion of meconium, the latter appears as a solitary mass inside fetal ascites or as disseminated echogenic masses distributed subdiaphragmatically or perihepatically. Within a couple of days, in most cases the echogenicity of the masses increases. Calcifications lead to distinct shadowing. These calcifications are often the only visible signs of a previous meconium peritonitis. Serial sonograms are essential for the management of pregnancies with meconium peritonitis. If the amount of fetal ascites does not increase and no signs of cardiovascular stagnation appear, no invasive intrauterine diagnostic and therapeutic steps are required. In none out of the nine cases was a cause found. 相似文献
364.
Gerhard Bringmann 《Die Naturwissenschaften》1979,66(1):22-27
The formation of tetrahydro-isoquinoline alkaloids in human and animal metabolisms subsequent to alcohol consumption is reported. The spectrum of identified products ranges from simple structures such as salsolinol to the complicated skeleton of protoberberines. These substances, hitherto found exclusively in plants, interfere with the biosynthesis, biodegradation and neurotransmission of the structurally closely related biogenic amines from which they are formed, and thus affect the vegetative nervous system. 相似文献
365.
Mammalian hibernation, which lasts on average for about 6 months, can reduce energy expenditure by >90% in comparison to active
individuals. In contrast, the widely held view is that daily torpor reduces energy expenditure usually by about 30%, is employed
for a few hours every few days, and often occurs only under acute energetic stress. This interpretation is largely based on
laboratory studies, whereas knowledge on daily torpor in the field is scant. We used temperature telemetry to quantify thermal
biology and activity patterns of a small arid-zone marsupial, the stripe-faced dunnart Sminthopsis macroura (16.9 g), in the wild and to test the hypothesis that daily torpor is a crucial survival strategy of this species in winter.
All individuals entered torpor daily with the exception of a single male that remained normothermic for a single day (torpor
on 212 of 213 observation days, 99.5%). Torpor was employed at air temperatures (T
a) ranging from approximately −1°C to 36°C. Dunnarts usually entered torpor during the night and aroused at midday with the
daily increase of T
a. Torpor was on average about twice as long (mean 11.0 ± 4.7 h, n = 8) than in captivity. Animals employed sun basking during rewarming, reduced foraging time significantly, and occasionally
omitted activity for several days in sequence. Consequently, we estimate that daily torpor in this species can reduce daily
energy expenditure by up to 90%. Our study shows that for wild stripe-faced dunnarts daily torpor is an essential mechanism
for overcoming energetic challenges during winter and that torpor data obtained in the laboratory can substantially underestimate
the ecological significance of daily torpor in the wild. 相似文献
366.
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
367.
de Paula FR Ferraz SF Gerhard P Vettorazzi CA Ferreira A 《Environmental management》2011,48(4):750-763
Riparian forests are important for the structure and functioning of stream ecosystems, providing structural components such
as large woody debris (LWD). Changes in these forests will cause modifications in the LWD input to streams, affecting their
structure. In order to assess the influence of riparian forests changes in LWD supply, 15 catchments (third and fourth order)
with riparian forests at different conservation levels were selected for sampling. In each catchment we quantified the abundance,
volume and diameter of LWD in stream channels; the number, area and volume of pools formed by LWD and basal area and tree
diameter of riparian forest. We found that riparian forests were at a secondary successional stage with predominantly young
trees (diameter at breast height <10 cm) in all studied streams. Results showed that basal area and diameter of riparian forest
differed between the stream groups (forested and non-forested), but tree density did not differ between groups. Differences
were also observed in LWD abundance, volume, frequency of LWD pools with subunits and area and volume of LWD pools. LWD diameter,
LWD that form pools diameter and frequency of LWD pools without subunits did not differ between stream groups. Regression
analyses showed that LWD abundance and volume, and frequency of LWD pools (with and without subunits) were positively related
with the proportion of riparian forest. LWD diameter was not correlated to riparian tree diameter. The frequency of LWD pools
was correlated to the abundance and volume of LWD, but characteristics of these pools (area and volume) were not correlated
to the diameter of LWD that formed the pools. These results show that alterations in riparian forest cause modifications in
the LWD abundance and volume in the stream channel, affecting mainly the structural complexity of these ecosystems (reduction
in the number and structural characteristics of LWD pools). Our results also demonstrate that riparian forest conservation
actions must consider not only its extension, but also successional stage to guarantee the quantity and quality of LWD necessary
to enable the structuring of stream channels. 相似文献
368.
Kitanovski Zoran Hovorka Jan Kuta Jan Leoni Cecilia Prokeš Roman Sáňka Ondřej Shahpoury Pourya Lammel Gerhard 《Environmental science and pollution research international》2021,28(42):59131-59140
Environmental Science and Pollution Research - Nitrated monoaromatic hydrocarbons (NMAHs) are ubiquitous in the environment and an important part of atmospheric humic-like substances (HULIS) and... 相似文献
369.
Ivančev-Tumbas Ivana Lammel Gerhard 《Environmental science and pollution research international》2021,28(42):59317-59318
Environmental Science and Pollution Research - Recently, nearly 500 study programmes related to environmental disciplines were detected in Europe (Lammel et al, Environ Sci Pollut Res 21:7211-7218... 相似文献
370.
Storch G 《Die Naturwissenschaften》2008,95(10):927-930
Most living mammal orders, including our own, started their career during the first 10 million years of the Cenozoic, the
Age of Mammals. The fossil record documents that early Paleogene adaptive radiations of various clades included tiny species
of the size of living shrews. Remains of particularly diminutive limb bones are described from the late Paleocene site of
Walbeck, Sachsen-Anhalt. Discovered in 1939, it has remained the only known Paleocene mammal-bearing locality from Germany.
The remains are referred to the family Adapisoriculidae, which is considered on the basis of the present postcranial evidence
to represent plesiadapiform primates rather than alleged lipotyphlan insectivores as previously proposed. The Walbeck fossils
compete with the Early Eocene species Toliapina vinealis from Europe and Picromomys petersonorum from North America for the status of the smallest known primate, fossil and living. Their estimated body weights are as small
as 10 g. The limb bones show features related to enhanced flexion at the elbow and hip joint, suggesting arboreal habits and
environments such as terminal branches. The diminutive size and tooth morphology suggest feeding on small insects and other
invertebrates. Postcranials are important to assess early radiations, such tiny specimens as the present ones are extremely
scarce in the fossil record, however. 相似文献