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1.
The preferred body temperature was determined for several groups of Sceloporus occidentalis previously acclimated to several constant temperature levels. Acclimation to a high temperature (35 degrees C) resulted in the selection of a lowered mean preferred body temperature, whereas acclimation to lower temperatures (12 degrees C and 25 degrees C) produced no change in the preferred body temperature. 相似文献
2.
Eagle RA Tütken T Martin TS Tripati AK Fricke HC Connely M Cifelli RL Eiler JM 《Science (New York, N.Y.)》2011,333(6041):443-445
The nature of the physiology and thermal regulation of the nonavian dinosaurs is the subject of debate. Previously, arguments have been made for both endothermic and ectothermic metabolisms on the basis of differing methodologies. We used clumped isotope thermometry to determine body temperatures from the fossilized teeth of large Jurassic sauropods. Our data indicate body temperatures of 36° to 38°C, which are similar to those of most modern mammals. This temperature range is 4° to 7°C lower than predicted by a model that showed scaling of dinosaur body temperature with mass, which could indicate that sauropods had mechanisms to prevent excessively high body temperatures being reached because of their gigantic size. 相似文献
3.
D G Drescher 《Science (New York, N.Y.)》1974,185(147):273-274
The rate of reduction of chinchilla cochlear microphonic response with exposure to steady noise is less at lower body temperatures and greater at higher body temperatures. Before exposure to noise, this auditory response is invariant within the range of temperatures employed. The mechanism of reduction of cochlear response appears to involve processes sensitive to body temperature. 相似文献
4.
针对育成期蛋鸡在散养状态下受环境影响大,易生病,体温检测困难的问题,采用红外热成像技术和多元回归分析的方法,对鸡体体表温度和翼下温度之间的关系进行研究,建立温度预测模型。环境温湿度会影响鸡体体表温度的测量,为使红外热像仪采集的体表温度能够准确的反应出鸡体真实温度,试验对鸡体翼下温度和体表温度进行同步测量,并采集饲养环境中的温湿度,通过分析各变量之间的相关性,找到能够反应鸡体真实温度的变量,建立最优温度预测模型。试验结果表明:1)散养状态下育成期蛋鸡羽毛覆盖区域温度和环境温度存在共线性;2)多元线性温度预测模型的平均相对误差为0.38%;3)多元非线性温度预测模型的平均相对误差为0.17%。表明红外热像仪可以用于蛋鸡的体温检测,而且多元非线性温度预测模型结果更加准确。 相似文献
5.
J L Griffin 《Science (New York, N.Y.)》1972,178(63):869-870
Within tested strains of the genera Naegleria and Acanthamoeba the ability to grow at high temperatures seems directly related to virulence, with nonvirulent strains unable to grow at normal or elevated body temperatures. Outside these genera, nonvirulent Hartmannella and Tetramitus do grow at elevated temperatures, which suggests a barrier to pathogenicity other than temperature sensitivity. The high optimal temperature of pathogenic Naegleria apparently explains previous difficulty in obtaining isolates from the aquatic environment. 相似文献
6.
HERREID CF 《Science (New York, N.Y.)》1963,142(3599):1573-1574
Body temperatures of Tadarida mexicana in their natural cave environment were usually maintained at high levels, even when ambient temperatures were low. Oxygen consumption rates were correspondingly higher in low environmental temperatures. However, in laboratory tests, body temperatures and metabolic rates are fairly dependent on ambient temperature. 相似文献
7.
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. 相似文献
8.
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. 相似文献
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10.
A.H. Ipema D. Goense P.H. Hogewerf H.W.J. Houwers H. van Roest 《Computers and Electronics in Agriculture》2008,64(1):49
A bolus containing a mote (temperature sensor, processor and radio) was placed in the rumen of a fistulated cow to monitor body temperature. Rumen temperature was measured every minute and stored in the internal buffer of the mote. The measured temperature was also transmitted to a base station by the mote every minute. A relay mote mounted on the cows’ left front leg assisted transmission of the information from rumen to the base station. Cow behaviour affected the success rate of data transmission. The base station received more than 50% of the transmitted data when the cow was standing. Success rate was lower than 40% when the cow was lying down. Rumen temperature varied diurnally with night-time temperatures higher than day-time temperatures. Drinking events resulted in distinct decreases of the rumen temperature. It is concluded that for the application of internal sensor motes wireless communication through the body and living environment of the animal works but improvements are possible. Research should also focus on the interpretation of sensor data on mote level for optimizing data recording frequency and transmission of data to dairy management practice. 相似文献
11.
为探讨温度对六斑异瓢虫生长发育的影响,分别在15、20、25和28 ℃条件下,对六斑异瓢虫各发育阶段的发育历期、发育速率、发育起点温度、有效积温、存活率及幼虫体长进行了研究。结果表明:六斑异瓢虫在15~28 ℃的温度范围内,发育历期均随温度的升高显著缩短,发育速率随温度的升高而加快,采用线性回归模型对六斑异瓢虫各发育阶段的发育速率进行模拟分析,模型拟合度较高,P值均小于0.05,达到显著水平。温度对1~3龄幼虫体长无显著性差异;4龄时,15 ℃下的4龄幼虫体长只有11.48 mm,显著短于其他温度。温度对六斑异瓢虫存活有一定的影响,随着温度的升高,总存活率呈下降趋势,28 ℃时最低,只有54.53%。综合各指标,适宜六斑异瓢虫生长的环境温度为15~20 ℃,六斑异瓢虫卵、1龄、2龄、3龄、4龄、蛹和总历期的发育起点温度分别为9.84、10.42、11.67、10.21、9.91、10.51、10.37 ℃,有效积温分别为54.49、26.77、19.32、27.35、54.73、73.37、269.77 ℃·d。 相似文献
12.
Thermoregulation in endothermic insects 总被引：2，自引：0，他引：2
B Heinrich 《Science (New York, N.Y.)》1974,185(153):747-756
On the basis of body weight, most flying insects have higher rates of metabolism, and hence heat production, than other animals. However, rapid rates of cooling because of small body size in most cases precludes appreciable endothermy. The body temperature of small flies in flight is probably close to ambient temperature, and that of flying butterflies and locusts is 5 degrees to 10 degrees C above ambient temperature. Many moths and bumblebees are insulated with scales and hair, and their metabolism during flight can cause the temperature of the flight muscles to increase 20 degrees to 30 degrees C above ambient temperature. Curiously, those insects which (because of size, insulation) retain the most heat in the thorax during flight, also require the highest muscle temperature in order to maintain sufficient power output to continue flight. The minimum muscle temperature for flight varies widely between different species, while the maximum temperature varies over the relatively narrow range of 40 degrees to 45 degrees C. As a consequence, those insects that necessarily generate high muscle temperatures during flight must maintain their thoracic temperature within a relatively narrow range during flight. Active heat loss from the thorax to the abdomen prevents overheating of the flight motor and allows some large moths to be active over a wide range of ambient temperatures. Bumblebees similarly transfer heat from the flight musculature into the abdomen while incubating their brood by abdominal contact. Many of the larger insects would remain grounded if they did not actively increase the temperature of their flight muscles prior to flight. Male tettigoniid grasshoppers elevate their thoracic temperature prior to singing. In addition, some of the social Hymenoptera activate the "flight" muscles specifically to produce heat not only prior to flight but also during nest temperature regulation. During this "shivering" the "flight" muscles are often activated in patterns different from those during flight. The muscles contract primarily against each other rather than on the wings. However, the rate of heat production during shivering and flight is primarily a function of the action potential frequency rather than of the patterns of activation. Thermoregulation is a key factor in the energetics of foraging of some of the flower-visiting insects. The higher their muscle temperature the more flowers they can visit per unit time. When food supplies are ample, bees may invest relatively large amounts of energy for thermoregulation. While shivering to maintain high body temperatures during the short intervals they are perched on flowers (as well as while in the nest), bumblebees often expend energy at rates similar to the rates of energy expenditure in flight. Unlike vertebrates, which usually regulate their body temperature at specific set points, the body temperature of insects is labile. It often appears to be maintained near the lower temperature at which the muscles are able to perform the function at hand. The insects' thermal adaptations may not differ as much from those of vertebrates as previously supposed when size, anatomy, and energy requirements are taken into account. 相似文献
13.
测定了5种温度(14 、17、 20、 24和29℃)下,白条锦蛇的耗氧量及耗氧率.结果表明:在这5种温度条件下,白条锦蛇的耗氧量均随体质量的增加而明显增大,而白条锦蛇的耗氧率则刚好相反,随体质量的增加耗氧率反而减小; 另外,白条锦蛇的耗氧量、耗氧率与温度均呈显著的线性回归关系.在14～29℃白条锦蛇的耗氧量、耗氧率均随温度升高而增加,并得出耗氧量x0与温度t的一元线性回归方程:x0=-25.25+3.51t,耗氧率Q0与温度t的一元线性回归方程Q0=-230.25+27.14t.白条锦蛇的耗氧率与温度的变化关系,说明白条锦蛇的新陈代谢率随环境温度改变而改变,在14～29℃白条锦蛇的新陈代谢随环境温度升高而加快. 相似文献
14.
为研究长绿飞虱的为害规律,制定合适的防治策略。对不同温度下长绿飞虱成若虫蜜露分泌量和体质量变化进行研究,建立了若虫蜜露排放量与体质量的回归方程。结果表明,长绿飞虱低龄若虫及不同体色成虫在不同温度下蜜露排放量无显著变化,但其高龄若虫在高温条件下平均蜜露排放量显著升高;雌成虫体质量为雄虫体质量的2倍,雌虫体质量在26 ℃最高;除5龄若虫外,温度未对若虫体质量产生显著影响。各温度条件下长绿飞虱若虫日均蜜露排放量与其体质量呈显著正相关。长绿飞虱为害最严重时期为4~5龄若虫期,故田间防治长绿飞虱时期应选择在3龄及3龄以前,当田间温度较低时,可以考虑适当放宽长绿飞虱的防治指标。 相似文献
15.
本文旨在探讨自然环境温湿度条件下不同温、湿度对黑白花奶牛体表不同部位皮温的影响,为疾病的诊断和防治提供科学依据。测定结果表明,在测定的温湿度范围内,湿度对皮温影响不明显,而温度对体表不同部位的皮温变化影响显著,呈正相关。体表各测区的皮温随着环境温度的升高而增加,其中心区,尾根和前乳房部位的皮温变化虽有增加,但上升幅度小;四肢下部各测区的皮温变化显著,幅度大。躯干部位皮温比四肢部位高,尾根和前乳房皮温最高,四肢部位皮温最低。当环境温度降低时,各测区皮温差大;当环境温度增高时,各测区皮温差小。 相似文献
16.
为了明确温度对杜仲梦尼夜蛾生长发育的影响,采用室内人工恒温饲养方法,设置 18、22、26、28℃和30℃ 5 个温度处理,研究温度对杜仲梦尼夜蛾各虫态发育历期、头宽、体长、体重及取食量和排粪量的影响。结果表明,在18~30℃范围内,杜仲梦尼夜蛾各虫态的发育历期随温度的升高而缩短,其世代发育历期在30℃时最短,为17 d;该虫完成1个世代的发育起点温度和有效积温分别为10.72℃和670.37日·度;随温度的变化,同龄幼虫的头宽、体长及体重的差异性不大,但随龄期的变化,这些参数的差异均达到显著水平;温度和龄期对幼虫的取排量均存在显著影响,随龄期的增加,幼虫的取排量显著增多,末龄幼虫取排量达到最大,占整个取排量的70%左右。 相似文献
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18.
R B Hey 《Science (New York, N.Y.)》1974,184(140):1001-1003
The Puerto Rican lizard Anolis cristatellus behaviorally regulates body temperature in an open habitat but passively tolerates lower and more variable temperatures in an adjacent forest where basking sites are few and distant. Thermoregulation may be adaptive only when costs resulting from associated losses of time and energy are low. 相似文献
19.
[目的]研究普通卷甲虫的抗寒性,为进一步预测下一年虫口发生提供参考资料。[方法]对2000只普通卷甲虫的体长、体宽、鲜重等生物学特征进行了测定,并对每一个体进行了不同低温强度及持续时间的冷冻培养。[结果]在低温条件下,卷甲虫的死亡率与培养温度和培养时间,以及在相同条件下雌、雄虫死亡率之间都具有明显的相关性,呈直线回归关系;一定的低温条件下,培养时间愈长,死亡率越高;在一定的培养时间下随着低温强度加大,死亡率明显升高。但在不同的培养条件下,卷甲虫的死亡率与它们的体长、体重都无明显相关性。[结论]普通卷甲虫的抗寒性与该地区年最低气温的变化相关联。 相似文献
20.
Gillooly JF Brown JH West GB Savage VM Charnov EL 《Science (New York, N.Y.)》2001,293(5538):2248-2251
We derive a general model, based on principles of biochemical kinetics and allometry, that characterizes the effects of temperature and body mass on metabolic rate. The model fits metabolic rates of microbes, ectotherms, endotherms (including those in hibernation), and plants in temperatures ranging from 0 degrees to 40 degrees C. Mass- and temperature-compensated resting metabolic rates of all organisms are similar: The lowest (for unicellular organisms and plants) is separated from the highest (for endothermic vertebrates) by a factor of about 20. Temperature and body size are primary determinants of biological time and ecological roles. 相似文献