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991.
The probability of being employed varies depending on several factors. Many of these are related to personal characteristics such as educational level, age, gender, or number and age of children. Nevertheless, other factors may be relevant, in particular the geographical environment. The purpose of this paper is to analyse the relevance of urban size and the position of each territory (in terms of its distance from large metropolises) for the probability of being employed in the Spanish economy. Following the set of economic regions suggested by Polése, Shearmur and Rubiera (2007 ), we try to explain the spatial patterns of employment distribution. Our results show some relevant differences between these alternative economic areas. We find that municipalities with similar sizes and located at a similar distance from a metropolis but belonging to different Autonomous Communities or provinces share similar employability patterns. 相似文献
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993.
994.
气候变化对内蒙古农牧业生态环境的影响 总被引:2,自引:1,他引:2
分析了数十年来气候变暖对内蒙古农牧业生态环境的影响。发现气候变暖使内蒙古地区无霜期延长,积雪、冰雹、雷暴、大风、沙尘暴日数减少,降水量也出现由少转多的变化。事实表明,气候增暖使内蒙古总的生态环境出现向好转化,但是增暖所带来的负面影响是病虫害的增加,加上人为的作用,严重地破坏了内蒙古的生态平衡。 相似文献
995.
SUN Lin-guang YIN Wei SU Xing-wen CHENG Wen-fang JIANG Wei-jian QIU Peng-xin YAN Guang-mei 《园艺学报》2005,21(3):479-483
AIM: To observe the expression of neuronal Aryl hydrocarbon receptor nuclear translocator 2 (ARNT2) involved in neuronal apoptosis evoked by low K+ and to investigate the relationship between ARNT2 and neuronal apoptosis. METHODS: After neuron apoptosis model was established, the changes of mRNA and protein of ARNT2 during apoptosis were investigated by RT-PCR and Western blotting, respectively. Immunofluorescence was analyzed by confocal microscopy to probe the subcellular localization of ARNT2. RESULTS: Induced by low K+, the expression of ARNT2 mRNA was up-regulated obviously at the point of 30 min, and peaks at the point of 1 h. This up-regulated expression lasted for 12 h, and the variation of ARNT2 protein was similar to that of mRNA. The results of immunofluorescence analyzed by confocal microscopy showed that the localization of ARNT2 protein was in the nucleus. CONCLUSION: ARNT2 locate in nuclei of normal cerebellar granule neurons of rat. During the process of apoptosis evoked by low K+, both mRNA and protein of ARNT2 are overexpressed. 相似文献
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997.
AIM: To investigate the influence of predator stress on hypothalamic-pituitary-adrenal (HPA) axis and IL-1β, IL-6 in mice with brain asymmetry. METHODS: By using paw preference test, right-pawed, left-pawed, and ambidextrous-pawed mice model were established. Mice with brain lateralization were exposed to their predator (cat). After acute and chronic predator stress by cats, EIA and ELISA were applied to detect plasma levels of corticosterone (CS), IL-1β and IL-6. RESULTS: (1) The level of plasma CS: in both acute and chronic predator stress group, right-pawed and ambidextrous mice had a higher level than that in their corresponding normal group (P<0.05). Meanwhile, the two groups also showed higher level than left-pawed in acute stress. Compared with the corresponding group under acute stress, left-pawed had much higher level of CS under chronic stress (P<0.05). (2) The level of plasma IL-1β: in normal group, left and right-pawed mice were higher than that in ambidextrous mice (P<0.01), of which left-pawed was the highest. In chronic stress group, the left-pawed exhibited higher level than that in right-pawed mice (P<0.05). (3) The level of IL-6: after chronic predator stress, ambidextrous mice had much higher level than that in other two groups (P<0.05). CONCLUSION: Under predator stress, the HPA axis and plasma proinflammatory cytokines (IL-1β, IL-6) in BALB/C mice were modulated by the brain asymmetrically, and brain lateralization may influence the function of immuno-endocrine network in psychological circumstances. 相似文献
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999.
The insecticidal activities of materials derived from the fruit of fennel, Foeniculum vulgare, against adults of Sitophilus oryzae, Callosobruchus chinensis and Lasioderma serricorne were examined using direct contact application and fumigation methods. The biologically active constituents of the Foeniculum fruits were characterized as the phenylpropenes (E)‐anethole and estragole, and the monoterpene (+)‐fenchone, by spectroscopic analysis. Responses varied with insect species, compound, dose and exposure time. In a filter paper diffusion test, estragole at 0.168 mg cm?2 caused 91% mortality to S oryzae adults within 1 day after treatment (DAT), whereas (+)‐fenchone and (E)‐anethole gave over 90% mortality at 2 and 4 DAT, respectively. Against C chinensis adults, all test compounds revealed potent insecticidal activities at 0.021 mg cm?2 at 2 DAT. Against L serricorne adults at 0.105 mg cm?2, (E)‐anethole gave 100% mortality at 1 DAT, whereas 90 and 60% mortality at 4 DAT was achieved with estragole and (+)‐fenchone, respectively. In a fumigation test, the test compounds were much more effective against adults of S oryzae, C chinensis and L serricorne in closed cups than in open ones, indicating that the insecticidal activity of test compounds was largely attributable to fumigant action. As naturally occurring insect‐control agents, the F vulgare fruit‐derived materials described could be useful for managing field populations of S oryzae, C chinensis and L serricorne. © 2001 Society of Chemical Industry 相似文献
1000.
Summary. Six sugarcane varieties, N: Co 310, F146, F148, F152, F153 and F156, were Found in a field trial to differ in their tolerance to pre-emergence diuron with units of susceptibility of 100, 1·57, 1·20, 1·60, 11·30 and 8·07, and to pre-emergence atrazine of 0·75, 0·97, 0·59, 1·44, 2·42 and 0·78 respectively. Relative tolerance was assessed by subjecting each variety to seven rates of the herbicides in geometric series and calculating the F values for monthly measurements of the cane plants through the growing seasons of both the autumn-planting and ratoon crops. Units of susceptibility of each variety were obtained by transforming each mean F value into a proportion of the value for the standard variety N: Co 310. Any residual effect of the pre-emergence herbicides even at 20 kg/ha a.i. on cane plants was found to be small and insignificant after ploughing field ridges 5 months from cane-planting. With diuron, increasing the rate up to 10 kg/ha began to cause a significant reduction of sugar yield per hectare of cane, while atrazine gave such a reduction only with 20 kg/ha. Détermination de la résistance variétale de la canne à sucre à l'éigard du diuron et de l'atrazine appliqués en pré-levée Résumé. Six variétés de canne à sucre, N:Co 310, F146, F148, F152, F153 et F156, ont manifesté dans un essai au champ des differences de résistance au diuron en pré-levée, avec des mesures de sensibilité de 1,00, 1,57, 1,20, 1,60, 11,30 et 8,07; pour l'atrazine en pré-levée, 0,75, 0,97, 0,59, 1,44, 2,42 et 0,78 respectivement. Une résistance relative fut établie en soumettant chaque variétéà sept doses des herbicides en progression géométrique et en calculant les valeurs de F pour des mensurations mensuelles des plantes de canne, durant la saison de croissance, à la fois pour les plantations d'automne et les repousses de cannes après recépage. Des unités dc sensibilité pour chaque variété furent obtenues en transformant chaque valeur moyenne de F en une proportion de la valeur pour la variety standard N:Co 310. L'effet résiduel des herbicides appliqués en pré-levée, même à 20 kg/ha (m.a.) sur les piantes de cannes fut faible et non significatif apres labour des billons à 5 mois de la plantation des cannes. Avec le diuron l'aecroissement de la dose jusqu’à 10 kg/ha provoqua un commencement de réduction significative de rendement en sucre par hectare, alors que l'atrazine provoqua une telle reduction seulement avec 20 kg/ha. Bestimmung der unterschiedlichen Toleranz von Zuckerrohrsorten gegenüber Diuron und Atrazin bei Vorauflaufbehandlung Zusammenfassung. Im Feldversuch wurde gefunden, dass die sechs Zuckerrohrsorten N: Co 310, F 146, F 148. F 152, F 153 und F 156 sich bei Vorauflaufbehandlung in ihrer Toleranz gegenüber Diuron und Atrazin unterscheiden. Die Suszeptibilitätseinheiten waren für Diuron 1,00, 1,57, 1,20, 1,60, 11,30 und 8,07, für Atrazin 0,75, 0,97, 0,59, 1,44, 2,42 und 0,78. Die Ermittlung der relativen Toleranz erfolgte, indem jede Sorte mit sieben Aufwandmengen der Herbizide in geometrischer Reihe behandelt wurde und die F-Werte für die monatlichen Messungen der Zuckerrohrpfianzen während der Vegetationsperiode berechnet wurden. Die Messungen erfolgten sowohl an im Herbst gepflanztem Zuckerrohr als auch an Wurzelschossen. Die Einheiten der Suszeptibilität für jede Sorte wurden durch Umformung eines jeden mittleren F-Wertes in einen auf die Standardsorte N: Co 310 bezogenen Relativwert erhalten. Die Wirkung von Rücks-tänden der Vorauflaufherbizide auf die Zuckerrohrpflanzen war selbst bei 20 kg/ha Wirkstoff nach Furchenpflügen 5 Monate nach der Auspflanzung gering und nicht signifikant. Diuron begann eine signifikante Minderung des Zuckerertrages pro Hektar hervorzurufen, wenn die Aufwandmenge bis auf 10 kg/ha gesteigert wurde, wahrend Atrazin erst bei 20 kg/ha eine solche Ertragsminderung verursachte. 相似文献