Deep, zonal subequatorial currents

Large-scale, westward-extending tongues of warm (Pacific) and cold (Atlantic) water are found between 2000 and 3000 meters both north and south of the equator in the Pacific and Atlantic oceans. They are centered at 5 degrees to 8 degrees north and 10 degrees to 15 degrees south (Pacific) and 5 degrees to 8 degrees north and 15 degrees to 20 degrees south (Atlantic). They are separated in both oceans by a contrasting eastward-extending tongue, centered at about 1 degrees to 2 degrees south, in agreement with previous helium isotope observations (Pacific). Thus, the indicated deep tropical westward flows north and south of the equator and eastward flow near the equator may result from more general forcing than the hydrothermal forcing previously hypothesized.     

Feeding and core temperature in albino rats: changes induced by preoptic heating and cooling

At an ambient temperature of 25 degrees C, selective cooling of the area preoptica medialis to 24 degrees +/- 1 degrees C produced a significant decrease in food intake together with hyperthermia. Heating the same area to 43 degrees +/- 1 degrees C resulted in the opposite effects. At an ambient temperature of 35 degrees C, heating the area preoptica medialis to 43 degrees C resulted in a decrease in food intake despite concomitant hypothermia.     

Ultraviolet damage to bacteria and bacteriophage at low temperatures

The survival of Escherichia coli B/r WP2 (tryptophan-requiring) from ultraviolet irradiation when suspended in 0.067M phosphate buffer (pH 7) has been studied over the temperature range 22 degrees to -269 degrees C. In unfrozen suspensions there was no appreciable change in sensitivity between 22 degrees and -10 degrees C. The sensitivity in the presence of ice progressively increased by a factor of 7 when the temperature was lowered to -79 degrees C. Between -79 degrees and -196 degrees C the sensitivity decreased to less than four times the sensitivity at 22 degrees C and was not appreciably different at -269 degrees C. Evidence from experiments with bacteriophage T1 and E. coli WP2 HCR(-) (a strain unable to excise thymine dimers) indicates that a new, qualitatively different lesion, less amenable to repair, may replace the thymine dimer in E. coli irradiated at -79 degrees C.     

Survival of mouse embryos frozen to -196 degrees and -269 degrees C

Mouse embryos survived freezing to -196 degrees C. Survival required slow cooling (0.3 degrees to 2 degrees C per minute) and slow warming (4 degrees to 25 degrees C per minute). Depending on the specific rates used, 50 to 70 percent of more than 2500 frozen and thawed early embryos developed into blastocysts in culture after storage at -196 degrees C for up to 8 days. When approximately 1000 of the survivors, including some frozen to -269 degrees C (4 degrees K), were transferred into foster mothers, 65 percent of the recipients became pregnant. More than 40 percent of the embryos in these pregnant mice gave rise to normal, living full-term fetuses or newborn mice.     

Forebrain temperature activates behavioral thermoregulatory response in arctic sculpins

Arctic sculpins of the genus Myoxocephalus adapted to water at 5 degrees C escaped from warm water at 20 degrees , 16 degrees , and 12 degrees C when their deep-body temperatures increased from an initial 5 degrees C to about 8 degrees C. Heating parts of the forebrain with water at 25 degrees C circulating through a pair of thermodes astraddle rostral parts of the forebrain shortened the time spent in the warm water and lessened the incease in deep-body temperature before exit from the warm water. Cooling the forebrain to about -1 degrees C caused a large increase in the body temperature and sometimes suppressed the escape from the warm water.     

Regulation of oxygen consumption and body temperature during torpor in a hummingbird, Eulampis jugularis

The West Indian hummingbird, Eulampis jugularis, maintained its body temperature in torpor at 18 degrees to 20 degrees C over an ambient temperature range of 2.5 degrees to 18 degrees C. At ambient below 18 degrees C oxygen consumption during torpor increased linearly with decreasing temperature. Thermal conductances were the same for resting and torpid Eulampis regulating their body temperatures at 40 degrees and 18 degrees C, respectively.     

Radar interferometric observations of venus at 70-centimeter wavelength

A radar interferometer was used to map unambiguously the surface reflectivity of Venus in the polarized mode at a wavelength of 70 centimeters. The observed region extended from 260 degrees to 30 degrees in longitude and from -60 degrees to 50 degrees in latitude with a surface resolution of approximately 3 degrees by 3 degrees . The result agrees well in most respects with earlier maps made elsewhere at shorter wavelengths and, in addition, discloses a number of new "features."     

Phase Transformation at High Temperatures in Hafnia and Zirconia

Phase transformation curves for HfO(2) and ZrO(2) have been made. Transformation hysteresis is discussed. The transformation of monoclinic to tetragonal as temperature increases occurs over the range 1000 degrees to 1200 degrees C in ZrO(2), and 1500 degrees to 1600 degrees C in HfO(2). With decreasing temperature the transition back to monoclinic occurs from 970 degrees to 750 degrees C in ZrO(2) and 1550 degrees to 1450 degrees C in HfO(2). These transformations have been visually observed in ZrO(2), but not in HfO(2).     

Regulation of body temperature in the blue-tongued lizard

Lizards (Tiliqua scincoides) regulated their internal body temperature by moving back and forth between 15 degrees and 45 degrees C environments to maintain colonic and brain temperatures between 30 degrees and 37 degrees C. A pair of thermodes were implanted across the preoptic region of the brain stem, and a reentrant tube for a thermocouple was implanted in the brain stem. Heating the brain stem to 41 degrees C activated the exit response from the hot environment at a colonic temperature 1 degrees to 2 degrees C lower than normal, whereas cooling the brain stem to 25 degrees C delayed the exit from the hot environment until the colonic temperature was 1 degrees to 2 degrees C higher than normal. The behavioral thermoregulatory responses of this ectotherm appear to be activated by a combination of hypothalamic and other body temperatures.     

Temperature Regulation in the Bumblebee Bombus vagans: A Field Study

Bombus vagans forages for nectar at 5 degrees C in shade and at 31 degrees C in sunshine. The production of heat while the bumblebee is on flowers, at ambient temperatures below 24 degrees C, helps to maintain a thoracic temperature that is near the minimum for flight between flowers. However, at ambient temperatures above 24 degrees C the thoracic temperature is no longer regulated at 32 degrees to 33 degrees C and rises.     

Temperature regulation of bacterial activity during the spring bloom in newfoundland coastal waters

While the spring phytoplankton bloom in Newfoundland coastal waters is in progress during April and May, at water temperatures between -1 degrees and +2 degrees C, bacterial growth and respiratory rates remain low. Microbial community respiration is not measurable at -0.2 degrees C. Particulate materials that would be utilized by microorganisms in 2 to 3 days at 20 degrees to 25 degrees C require 11 days at 4 degrees C and 18 days at -0.2 degrees C. Thus, photosynthesis is active but microbial utilization of the products is suppressed. High secondary production in cold water may result from the low rate of microbial decomposition, enabling herbivores to utilize much of the primary production.     

Thermophilic ostracod: aquatic metazoan with the highest known temperature tolerance

The upper lethal temperature for an ostracod of the genus Potamocypris collected from a thermal stream ranged from 49 degrees C for incubation of more than 5 hours to 55.75 degrees C for 1-minute incubations. Field collections were held at 35 degrees C for less than 24 hours before experimental incubations. Calculated temperatues for 50 percent mortality for 60, 40, 20, 10, 5, and 1 minute of exposure were 50.44 degrees , 50.96 degrees , 51.43 degrees , 52.03 degrees , 52.77 degrees , and 55.12 degrees C, respectively.     

Solar cycle variation of exospheric temperatures Mars and venus: a prediction for mariner 6 and 7

Calculations have been made to determine the effects of variations in the extreme ultraviolet solar radiation on the upper atmospheres of mars and Venus. The results indicate that the exospheric temperature from 300 degrees K to 600 degrees K during the solar cycle, with a corresponding range on Venus of 450 degrees K to 850 degrees K. At the present time, the temperature of the Martain exosphere should be approximately 500 degrees K.     

Bacterial Sulfate Reduction Above 100{degrees}C in Deep-Sea Hydrothermal Vent Sediments

The currently known upper temperature limit for growth of organisms, shared by a number of archaebacteria, is 110 degrees C. However, among the sulfate-reducing bacteria, growth temperatures of greater than 100 degrees C have not been found. A search for high-temperature activity of sulfate-reducing bacteria was done in hot deep-sea sediments at the hydrothermal vents of the Guaymas Basin tectonic spreading center in the Gulf of California. Radiotracer studies revealed that sulfate reduction can occur at temperatures up to 110 degrees C, with an optimum rate at 103 degrees to 106 degrees C. This observation expands the upper temperature limit of this process in deep-ocean sediments by 20 degrees C and indicates the existence of an unknown group of hyperthermophilic bacteria with a potential importance for the biogeochemistry of sulfur above 100 degrees C.     

冷藏对石蒜鳞茎休眠生理及开花的影响

为掌握冷藏对石蒜(Lycoris radiata)鳞茎休眠生理及开花的影响,研究了石蒜球根在6和9℃低温下分别冷藏4、7、9周后,鳞茎尖内的生理变化,并观察其开花时间.结果表明:在6℃冷藏4周花期推迟19d;9℃冷藏4周花期推迟12d;6、9℃条件下冷藏7和9周均未开花.在6℃冷藏4周条件下,蛋白质和核酸质量分数均保持着较低的水平;同时对内源激素质量摩尔浓度测定表明内源激素IAA极显著对花期具有影响作用,ABA、ZR也具有影响花期的作用,而内源激素GA3质量摩尔浓度变化对开花无显著影响.     

Milankovitch radiation variations: a quantitative evaluation

A quantitative determination of changes in the surface temperature caused by variations in insolation calculated by Milankovitch has been made through the use of the thermodynamic model of Adem. Under extreme conditions, mean coolings of 3.1 degrees and 2.7 degrees C, respectively, at latitudes 25 degrees and 65 degrees N are obtained for Milankovitch radiation cycles. At the sensitive latitude 65 degrees N, a mean cooling below the present temperature for each of the times of radiation minimum is only 1.4 degrees C. This result indicates that the Milankovitch effect is rather small to have triggered glacial climates.     

逆温对大兴安岭地区天气的影响

利用欧洲数值模式产品ECMWF 20:00的零零场的资料和大兴安岭地区自动站的实况资料,采用统计分析的方法,分析逆温对大兴安岭地区天气的影响。结果表明,逆温会导致大兴安岭地区最低气温明显偏低;冬季,它会使南部最低气温比前一日ECMWF 20:00的零零场的温度场低8~14℃,北部低16~18℃;春季,使南部最低气温比前一日ECMWF 20:00的零零场的温度场低3~12℃,北部低10~14℃;秋季,使南部最低气温比前一日ECMWF 20:00的零零场的温度场低3~10℃,北部低10~12℃;夏季,使南部最低气温比前一日ECMWF 20:00的零零场的温度场低2~8℃,北部低8~10℃;逆温还会导致大兴安岭地区雾的生成。     

Dynamics of carbon monoxide binding by heme proteins

Rebinding of carbon monoxide to myoglobin and to cytochrome P-450 after removal by a light flash occurs down to 50 degrees K for myoglobin and 25 degrees K for cytochrome P-450 in glycerol-water solution. Above 240 degrees K the reaction is second order; between 240 degrees and 200 degrees K the rebinding becomes exponential and independent of the carbon monoxide concentration. Below 150 degrees K the reaction follows a power law and is approximately 10(3) times faster for cytochrome P-450 than for myoglobin.     

Oyster herpes-type virus

A herpes-type virus infection, the first to be found in an invertebrate animal, is reported in the oyster Crassostrea virginica. Intranuclear herpes-type viral inclusions were more prevalent in the oyster at elevated water temperatures of 28 degrees to 30 degrees C than at normal ambient temperatures of 18 degrees to 20 degrees C. The inclusions were associated with a lethal disease at the elevated temperatures.     

影响荷斯坦奶牛难产度的因素分析

[目的]从繁殖和生产性能上探讨各因素对新疆地区荷斯坦奶牛难产度的影响.[方法]采用SAS8.1软件对影响难产度的因素进行最小二乘方差分析.[结果]:不同胎次对难产度有显著的影响(P<0.05);不同产犊季节对难产度有显著的影响(P<0.05);怀孕天数对难产度的影响不显著(P>0.05);产犊间隔对难产度有极显著的影响(P<0.01);犊牛的性别对难产度有显著的影响(P<0.05);犊牛的初生重对难产度有极显著的影响(P<0.01);产犊类型对难产度有极显著的影响(P<0.01);305d产奶量对难产度影响不显著(P>0.05).[结论]通过大量的记录资料对荷斯坦奶牛难产度因素进行分析,这将有利于牛场有效地预防难产,降低难产的发生率.