首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Africa was seasonally analyzed by 4 different indices:Effective Temperature, Predicted 4-hr Sweat Rate, Relative Strain and Still-Air Temperature. These classifications were applied to approximately 800 station on the continent, resulting in 9 maps which were reduced from an original scale of 1:15,000,000.Some of the major findings indicate that areas often considered as "tropical" actually indicate lesser climatic stress than those in very hot-dry regions or transition areas between very hot-dry and hot-humid. The northern hemisphere summer is by far the most severe, physiologically, over vast areas of northern Africa. Regions of greatest stress are located along the southern Red Sea, interior southern Somalia and, to a lesser degree, the Djouf Basin and Bodele Depression. The year-round mildest areas occur most frequently in parts of the eastern highlands and Atlantic coast (those influenced by cold currents). Few really oppressive conditions during nighttime could be observed.
Zusammenfassung Afrika wird jahreszeitlich nach 4 verschiedenen Indices analysiert: effektive Temperatur, vorhergesagte 4-stündige Schweissmenge,Relative Belastung und Temperatur bei Windstille. Diese Klassifizierung wurde bei etwa 800 Stationen des Kontinents angewandt. Sie ergab 8 Karten, die vom ursprünglichen Massstab von 1:15 000 000 reduziert wurden. Einige der Hauptergebnisse zeigen, dass Gebiete, die oft als "tropisch" angesehen werden, in Wirklichkeit eine geringere klimatische Belastung aufweisen, als die in sehr warm-trockenen oder in Ubergangsgebieten zwischen sehr heiss-trocken und heiss-feucht. Der Sommer der nördlichen Hemisphäre ist über weiten Gebieten Nordafrikas bei weitem die physiologisch belastendste Jahreszeit.Gebiete mit grösster Belastung liegen längs des südlichen Roten Meeres, im inneren südlichen Somalia, in geringem Ausmass im Djouf-Becken und der Bodele-Mulde. Die im Jahresverlauf mildesten Gebiete liegen am häufigsten in Teilen der östlichen Hochländer und der Atlantikküste, die durch kalte Strömungen beeinflusst wird. Nur wenig wirklich drückende Bedingungen wurden während der Nacht beobachtet.

Resume On analyse par saison le climat de l'Afrique selon quatre critères différents: la température effective, la quantité de sueur prévue pour 4 heures, la tension relative des individus et la température par temps calme.On a appliqué ces critères à environ 800 stations du dit Continent. Il en est résulté 9 cartes qui ont été ensuite réduites à l'échelle de 1:15 000 000.Un des principaux résultats est de démontrer que des régions qui sont souvent considérées comme "tropicales"sont moins éprouvantes pour l'homme que ce n'est le cas dans des climats secs et très chauds ou dans des zones de transition entre les climats très chauds-secs et chauds-humides. L'été de l'hémisphère nord est de loin le plus rude, physiologiquement parlant, et cela surtout dans de vastes régions de l'Afrique du Nord.Les régions offrant le climat le plus éprouvant sont situées sur les côtes sud de la Mer Rouge, à l'intérieur de la Somalie du sud et, mais à un degré moindre,dans le Bassin du Djouf et dans la dépression de Bodele. Les régions les meilleures tout le long de l'année se rencontrent en général dans certaines partie des hauts plateaux de l'est ainsi que sur les côtes de l'Atlantique où l'on rencontre des courants frais. On n'enregistre que peu de conditions vraiment éprouvantes pendant la nuit.


This article is a partial condensation of the Ph.D. dissertation "Physiological Climates of Africa", completed at the University of California, Los Angeles, Department of Geography, 1966. Committee in charge: Profs.R.F.Logan (chairman),R.M. Glendinning (geography), B.E.Thomas (geography), M.Neiburger (meteorology), D.T. Rice (M.D., public health).  相似文献   

3.
Investigations performed in 85 clinically healthy smokers indicated the decrease in the total count of T lymphocytes depending on the smoking time and simultaneous lack of alterations in the B cell count, the count of "non-T, non-B" cells, was increased in smokers. These changes were accompanied by lowered levels of IgA and IgM in the blood serum. The authors discuss the significance of their observations in the light of controversial data from literature.  相似文献   

4.
5.
The important requirement that COST Action 730 demanded of the physiological model to be used for the Universal Thermal Climate Index (UTCI) was its capability of accurate simulation of human thermophysiological responses across a wide range of relevant environmental conditions, such as conditions corresponding to the selection of all habitable climates and their seasonal changes, and transient conditions representing the temporal variation of outdoor conditions. In the first part of this study, available heat budget/two-node models and multi-node thermophysiological models were evaluated by direct comparison over a wide spectrum of climatic conditions. The UTCI-Fiala model predicted most reliably the average human thermal response, as shown by least deviations from physiologically plausible responses when compared to other models. In the second part of the study, this model was subjected to extensive validation using the results of human subject experiments for a range of relevant (steady-state and transient) environmental conditions. The UTCI-Fiala multi-node model proved its ability to predict adequately the human physiological response for a variety of moderate and extreme conditions represented in the COST 730 database. The mean skin and core temperatures were predicted with average root-mean-square deviations of 1.35 ± 1.00°C and 0.32 ± 0.20°C, respectively.  相似文献   

6.
mT7 medium performed no better than m-Endo medium in enumerating cells of Escherichia coli and Citrobacter freundii exposed to ozone. Also, there was no difference in the plate count of heterotrophic bacteria in ozonated raw water determined on modified Henrici agar or R2A agar. Statistically significant differences were seen between bacteria and the type of water in which they were suspended during ozonation.  相似文献   

7.
Summary The abilities of the white-rot fungi Chrysosporium lignorum, Trametes versicolor, Phanerochaete chrysosporium and Stereum hirsutum to mineralize 3,4-dichloroaniline, dieldrin and phenanthrene were investigated. S. hirsutum did not mineralize any of the test compounds but the other strains partly mineralized them all to varying degrees. The relative degradation rates per unit biomass were T. versicolor > C. lignorum > P. chrysosporium. Evidence was obtained for the production of water-soluble metabolic intermediates but no attempt was made to characterize these. It was found that mineral salts-glucose medium supplemented with trace mineral nutrients, vitamins and 1.5 mm 3,4-dimethoxybenzyl alcohol (veratryl alcohol) resulted in the highest mineralization rate. At no time in these experiments was there detectable extracellular ligninase (lignin peroxidase) activity. Offprint requests to: P. Morgan  相似文献   

8.
9.
10.
mT7 medium performed no better than m-Endo medium in enumerating cells of Escherichia coli and Citrobacter freundii exposed to ozone. Also, there was no difference in the plate count of heterotrophic bacteria in ozonated raw water determined on modified Henrici agar or R2A agar. Statistically significant differences were seen between bacteria and the type of water in which they were suspended during ozonation.  相似文献   

11.
1. Wistar rats of both sexes daily received an ethanol solution of ammonium metavanadate (AMV) of 0.3 mg V/cm3 5% ethanol concentration as sole drinking liquid, for a period of 4 weeks. 2. The reference groups received for drinking aqueous AMV solution, or 5% ethanol, or water. 3. In animals drinking both water and ethanol AMV solution a decrease in the erythrocyte count and haemoglobin level was noted together with an increase of the percentage of reticulocytes and polychromatophilic erythrocytes in the peripheral blood. 4. A small rise of the percentage of polychromatophilic and orthochromatic erythroblasts was at the same time noted in the bone marrow of animals receiving ethanol AMV solution. 5. In the group of animals drinking 5% ethanol a fall of the erythrocyte count was observed and a rise of the leukocyte count, particularly of lymphocytes. 6. Substitution of water by 5% ethanol solution as solvent for AMV did not have any distinct influence on the toxicity of the tested compound.  相似文献   

12.
Occupational, environmental, or domestic exposure of human beings to extremely low-frequency (50- or 60-Hz) electric and magnetic fields varies continuously over time. In epidemiological studies of possible health effects, exposures over long durations must be aggregated in terms of simple summary indices. However, there are many different, biologically plausible, ways of aggregating the data. While awake, each of 20 electric utility personnel and 16 office workers had provided minute-by-minute measures of incident electric (V/m) and magnetic (muT) fields over a 7-day period via personal dosimeters. Once the measures were aggregated as means, medians, peaks, and other indices, intercorrelations between all index pairs were calculated; correlation matrices are presented for the utility and office workers both by group and when pooled. Product-moment coefficients (r) greater that .80 were found between the time-weighted arithmetic mean (TWA) and indices that explicitly emphasize short but highly intense exposures, such as peak values and time above thresholds. Medians and geometric means were less highly correlated with the TWA. Use of only a few indices, perhaps the TWA alone, may sacrifice but little statistical power in most epidemiological studies of utility workers exposed to ELF fields. However, correlations between electric-field strength and magnetic-field density were generally quite weak, as were correlations of either with high-frequency transients; these findings underscore the need to measure each of these variables in epidemiological studies. Indices of exposure incurred outside the workplace were less strongly correlated, which may indicate the need to use several indices in general-population studies.  相似文献   

13.
14.
15.
Summary Six fast growing ligninolytic white-rot fungi were compared with Phanerochaete chrysosporium. The results showed that the fungi have similar ligninolytic systems, although minor differences exist. Like in P. chrysosporium the ligninolytic system could be induced by veratryl alcohol in Coriolus versicolor and Chrysosporium pruinosum. These three lignin peroxidase producing fungi were the fastest lignin degraders in stationary cultures, whereas in agitated cultures Bjerkandera adusta showed highest lignin degradation rates. Metabolites accumulating during the degradation of veratryl alcohol were analyzed and compared. Peroxidase production seems to be a common feature of all the tested fungi. Polyclonal antibodies against the lignin peroxidase with pl of 4.65 from P. chrysosporium reacted with the extracellular peroxidases of C. pruinosum, C. versicolor and B. adusta, but not with those of Pleurotus ostreatus.Dedicated to Professor Dr. Hans-Jürgen Rehm on the occasion of his 60th birthday  相似文献   

16.
17.
The purpose of this study was to test the applicability of different methods of river habitat assessment and their respective indices in a series of sample sites in Italy. These investigations were carried out within the EU AQEM project with the aim of combining the macroinvertebrate information with that achieved by investigating the hydromorphological characteristics of the river ecosystem as well as the surrounding landscape features. The River Habitat Survey (including the derived indices Habitat Modification Score and Habitat Quality Assessment) from U.K., and three Italian indices (Index of Fluvial Functioning, Buffer Strip Index and Wild State Index) were applied at 33 AQEM sites distributed in three different Italian river types. The obtained results indicate the overall ability of the applied indices to detect the degradation gradient, including river morphology and habitat, in the studied riverine ecosystems. Index of Fluvial Functioning seems useful to promptly describe the ecological quality of rivers as suggested by the good correlation with the AQEM multimetric biotic index. The Buffer Strip Index, showing a clear affinity with the Habitat Quality Assessment, seems suitable to assess richness and quality of the physical structure of a riverine site. The Habitat Modification Score recorded efficiently the morphological impact where present (e.g., North Apennine river sites), while the Italian indices appear to be not appropriate for differentiating this impact type from the general degradation of rivers.  相似文献   

18.
It is shown that the increasing content of lead in blood (6.3 and 3.7 times) and liver (30.1 and 4.6 times) in rats after 14-days per os exposure both to lead acetate (macrodispersed form) and lead nanoparticles (nanoform) in a dose of 7 mg/100 g of body weight leads to the increased of activity of blood enzymes: alanine aminotransferase, aspartate aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, lactate dehydrogenase and a decrease of creatinine level. Lead in nanoform with slight accumulation, due to the greater elimination, expressed higher biological activity and reactivity as compared to macrodispersed form. Thus the exposure to lead in different dispersed form suggests metabolic disorders in rats, and accumulation of lead and biochemical changes are more expressed in the liver.  相似文献   

19.
There are few papers about physiological indices in Callithrix penicillata, an increasing primate model in biomedicine. We investigated levels of plasmatic cortisol, plasmatic glucose, free fatty acids, blood cells, tympanic temperature, rectal temperature in C. penicllata, under a fast restraint. Measures of body and weight were accomplished. Males and females were not different regarding any measurements. Body measurements indicated differences between adults and juveniles. Adults showed higher hematocrit and a tendency for higher free fatty acids than juveniles. Right tympanic temperature was higher in adults than juveniles. This result suggests a higher reaction metabolism in adults than juveniles under a restraint stress. Due to the short-time of collecting the data, plasmatic cortisol did not influence physiological parameters. Therefore, we suggest that present results could be considered referential values of C. penicillata physiology.  相似文献   

20.
In the present study, we investigate the determination accuracy of the Universal Thermal Climate Index (UTCI). We study especially the UTCI uncertainties due to uncertainties in radiation fluxes, whose impacts on UTCI are evaluated via the mean radiant temperature (Tmrt). We assume “normal conditions”, which means that usual meteorological information and data are available but no special additional measurements. First, the uncertainty arising only from the measurement uncertainties of the meteorological data is determined. Here, simulations show that uncertainties between 0.4 and 2 K due to the uncertainty of just one of the meteorological input parameters may be expected. We then analyse the determination accuracy when not all radiation data are available and modelling of the missing data is required. Since radiative transfer models require a lot of information that is usually not available, we concentrate only on the determination accuracy achievable with empirical models. The simulations show that uncertainties in the calculation of the diffuse irradiance may lead to Tmrt uncertainties of up to ±2.9 K. If long-wave radiation is missing, we may expect an uncertainty of ±2 K. If modelling of diffuse radiation and of longwave radiation is used for the calculation of Tmrt, we may then expect a determination uncertainty of ±3 K. If all radiative fluxes are modelled based on synoptic observation, the uncertainty in Tmrt is ±5.9 K. Because Tmrt is only one of the four input data required in the calculation of UTCI, the uncertainty in UTCI due to the uncertainty in radiation fluxes is less than ±2 K. The UTCI uncertainties due to uncertainties of the four meteorological input values are not larger than the 6 K reference intervals of the UTCI scale, which means that UTCI may only be wrong by one UTCI scale. This uncertainty may, however, be critical at the two temperature extremes, i.e. under extreme hot or extreme cold conditions.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号