Observations of air temperature changes in a steppe marmot burrow were performed from late July to mid-October. Until early September, temperature in the burrow remained relatively constant, but then it began to decrease rapidly. This occurred after air temperature above the ground became equal to the temperature in the burrow. Supposedly, it is in this particular period that marmots begin to plug the entrance to the burrow with earth, thus reducing heat exchange between the increasingly cold aboveground air and the air in the burrow. 相似文献
To assess and plan future risk-analysis research projects, 275 documents describing methods and tools for assessing the risks associated with industrial machines or with other sectors such as the military, and the nuclear and aeronautics industries, etc., were collected. These documents were in the format of published books or papers, standards, technical guides and company procedures collected throughout industry. From the collected documents, 112 documents were selected for analysis; 108 methods applied or potentially applicable for assessing the risks associated with industrial machines were analyzed and classified. This paper presents the main quantitative results of the analysis of the methods and tools. 相似文献
A water regime, estimated based on transpiration rate, water content of shoots, concentration of cell sap, and water consumption per unit area, was studied for black saxaul. The seasonal course of black saxaul transpiration during the growing season increased by the middle of summer (July) and decreased towards autumn. The highest transpiration rate of black saxaul was found in Karnabchul, where ground waters poorly mineralized, located at a depth of 14–20 m in nonsaline soils. The lowest transpiration rate was detected in the Nishan “steppe,” where ground waters were also located at 14–20 m, however they were highly mineralized, and the soil profile was highly salinated. The Southwestern Kyzylkum, characterized by ground waters at a very deep location (more than 100 m) and low soil salinity, occupied an intermediate position in terms of transpiration rate. The maximal water consumption for transpiration during the vegetation period was observed in Karnabchulat 642.5 mm/ha, then in the Nishan “steppe” at 352.5. The minimal value was detected in the Southwestern Kyzylkum at 171.0.
Environmental lead poses a serious threat for public health, particularly, for children. The use of substances with metal-binding properties, such as natural alginates, may be a potentially effective method for elimination of toxic metal ions from human body. In present study, effect of calcium alginate isolated from brown algae on distribution of the lead ions in preschool children was investigated. In the beginning of the study, lead concentration in urine, feces, and hair was determined. Then these children were administered a dietary supplement containing calcium alginate for four weeks. The results showed that all children participated in the study had a high baseline median lead level in urine (1.1 µg/L), feces (4.6 µg/g), and hair (5.0 µg/g). Administration of calcium alginate resulted in twofold increase of the urine lead level within two weeks from the start of the treatment. At the end of alginate administration, significant decrease of lead concentration in hair was registered. These results suggest that calcium alginate can potentially prevent accumulation of the lead ions in the body and may be used as an active agent for elimination of this toxic metal from human body. 相似文献