小麦残茬落叶的分解与土壤因子间动态关系的研究

东北高寒地区的黑钙土土质优良肥沃 ,适合小麦、大豆和玉米等种植。近年来 ,由于人们只重视无机化肥的使用 ,忽视了地力培育 ,大量秸秆被移出田外 ,造成土壤有机质含量降低 ,土壤板结 ,使原本高产的农田逐渐变成中低产田 ,甚至有的已成为撂荒地。因此 ,研究当前农田土壤对枯枝落叶的分解现状 ,对于认识现有耕种条件下 ,农田土壤亚系统的物质转化和能量流动具有实际意义。1　研究地区和研究方法1 .1　自然概况该研究是在黑龙江省克山师专农场进行的。地理位置位于东经 1 2 5°8′～ 1 2 6°8′,北纬 47°50′～ 48°33′。年均气温 1 .3℃ ,1…     

Dynamics of the heat exchange in rats upon getting out of the state of artificial deep hypothermia

With the help of thermometry and general calorimetry the changes in the heat exchange were determined in the rats upon their getting out of artificial deep hypothermia (the temperature in the rectum was 20 degrees C) at the temperature in the calorimeter chamber 20 degrees C. An attempt was made to find out what part of the heat production during an animal self-warming is used for increasing its body temperature and what part of the heat production is released to the environment by the animal. The experiments revealed a complex relationship between the body temperature, the heat loss, and the total heat production during the animal selfwarming. The total heat production first increased and, after reaching the maximum, decreased gradually. Moreover, the experiments showed that during three and more hours of observation the body temperature did not reach the initial level, the same was true for the total heat production, which in these experiments was the sum of the heat loss and the production spent for warming the animal body.     

Dynamics of the heat exchange in rats upon getting out of the state of artificial hypothermia

With the help of thermometry and general calorimetry, changes in the heat exchange were determined in the non-hibernating mammals (rats) upon their getting out of artificial deep hypothermia (the temperature in the rectum was 22-24 degrees C) at the temperature in the calorimeter chamber 22 degrees C. An attempt was made to find out what part of the heal production during animal self-warming is used for increasing its body temperature and what part of the heat production is released to the environment by the animal. The experiments revealed a complex relationship between the body temperature, the heat loss, and the total heat production during the animal self-warming. The result was that the total heat production first increased and, after reaching the maximum, decreased gradually. The experiments showed that during two and more hours of observation the body temperature did not reach the starting level, the same was true for the total heat production, which was the sum of the heat loss and the heat production spent for warming the animal body.     

Crossing regimes of temperature dependence in animal movement

A pressing challenge in ecology is to understand the effects of changing global temperatures on food web structure and dynamics. The stability of these complex ecological networks largely depends on how predator–prey interactions may respond to temperature changes. Because predators and prey rely on their velocities to catch food or avoid being eaten, understanding how temperatures may affect animal movement is central to this quest. Despite our efforts, we still lack a mechanistic understanding of how the effect of temperature on metabolic processes scales up to animal movement and beyond. Here, we merge a biomechanical approach, the Metabolic Theory of Ecology and empirical data to show that animal movement displays multiple regimes of temperature dependence. We also show that crossing these regimes has important consequences for population dynamics and stability, which depend on the parameters controlling predator–prey interactions. We argue that this dependence upon interaction parameters may help explain why experimental work on the temperature dependence of interaction strengths has so far yielded conflicting results. More importantly, these changes in the temperature dependence of animal movement can have consequences that go well beyond ecological interactions and affect, for example, animal communication, mating, sensory detection, and any behavioral modality dependent on the movement of limbs. Finally, by not taking into account the changes in temperature dependence reported here we might not be able to properly forecast the impact of global warming on ecological processes and propose appropriate mitigation action when needed.     

Temperature‐dependent body size effects determine population responses to climate warming

Current understanding of animal population responses to rising temperatures is based on the assumption that biological rates such as metabolism, which governs fundamental ecological processes, scale independently with body size and temperature, despite empirical evidence for interactive effects. Here, we investigate the consequences of interactive temperature‐ and size scaling of vital rates for the dynamics of populations experiencing warming using a stage‐structured consumer‐resource model. We show that interactive scaling alters population and stage‐specific responses to rising temperatures, such that warming can induce shifts in population regulation and stage‐structure, influence community structure and govern population responses to mortality. Analysing experimental data for 20 fish species, we found size–temperature interactions in intraspecific scaling of metabolic rate to be common. Given the evidence for size–temperature interactions and the ubiquity of size structure in animal populations, we argue that accounting for size‐specific temperature effects is pivotal for understanding how warming affects animal populations and communities.     

An implantable nerve cooler for the exercising dog

An implantable nerve cooler has been constructed to block cervical vago-sympathetic activity in the exercising dog reversibly. An insulated gilt brass container implanted around the nerve is perfused with cooled alcohol via silicone tubes. The flow of alcohol is controlled by an electromagnetic valve to keep nerve temperature at the required value. Nerve temperature is measured by a thermistor attached to the housing and in contact with the nerve. It is shown that, during cooling, temperature at this location differs less than 2 degrees C from nerve core temperature. Measurement of changes in heart rate revealed that complete vagal block in the conscious animal is obtained at a nerve temperature of 2 degrees C and can be achieved within 50 s. During steady-state cooling in the exercising animal nerve temperature varied less than 0.5 degree C. When the coolers after 2 weeks of implantation were removed they showed no oxydation and could be used again.     

Effect of thermal conductance on water economy in the antelope jack rabbit, Lepus alleni

The heat and water balance of the antelope jack rabbit, Lepus alleni, was studied at various ambient temperatures. At high ambient temperature the animal primarily depends on evaporation for dissipation of the heat load. The use of water was, however, less than could be expected if only body size is considered. It was shown that, when the ambient temperature is below body temperature, there is a two- to three-fold increase in the conductance of the animal as ambient approaches body temperature. This facilitates dry heat loss and contributes to water economy. At ambient temperatures above body temperature the direction of heat flow is reversed, now being from the environment to the body. In this situation the heat flow inwards is impeded by a decrease in conductance to minimal values, thus achieving a considerable saving in the use of water for evaporation.     

First investigations to refine video-based IR thermography as a non-invasive tool to monitor the body temperature of calves

In this study, a video-based infrared camera (IRC) was investigated as a tool to monitor the body temperature of calves. Body surface temperatures were measured contactless using videos from an IRC fixed at a certain location in the calf feeder. The body surface temperatures were analysed retrospectively at three larger areas: the head area (in front of the forehead), the body area (behind forehead) and the area of the entire animal. The rectal temperature served as a reference temperature and was measured with a digital thermometer at the corresponding time point. A total of nine calves (Holstein-Friesians, 8 to 35 weeks old) were examined. The average maximum temperatures of the area of the entire animal (mean±SD: 37.66±0.90°C) and the head area (37.64±0.86°C) were always higher than that of the body area (36.75±1.06°C). The temperatures of the head area and of the entire animal were very similar. However, the maximum temperatures as measured using IRC increased with an increase in calf rectal temperature. The maximum temperatures of each video picture for the entire visible body area of the calves appeared to be sufficient to measure the superficial body temperature. The advantage of the video-based IRC over conventional IR single-picture cameras is that more than one picture per animal can be analysed in a short period of time. This technique provides more data for analysis. Thus, this system shows potential as an indicator for continuous temperature measurements in calves.     

Temperature and air humidity as factors influencing sleep and wakefulness

Summary In experiments on rats we studied the influence of temperature (21, 27 and 33° C) and air humidity (50, 70 and 90 %) on the duration of sleep and insomnia.The sleep of an animal, exposed to variously warm and humid air for 24 hours, is shortened the more, the higher the humidity and temperature of air. After insomnia lasting 24 hours and preceeded by an exposure to variously warm and humid air for one hour, sleep debt is increased at the rate at which air humidity and temperature of the exposure is raised. Similar changes of the animal's sleep depth occur also in such cases where the exposure of the animal is carried out during insomnia.     

实验动物的环境与福利

实验动物在生物科学研究领域中的应用不断发展,其饲养环境和福利保障的问题已越来越被国际所关注。实验动物的环境与福利不仅是对动物本身的保护,更重要的是对动物试验结果的保证。本文详细论述了大环境（温度、湿度、气流等方面）及小环境（笼具、饲养密度、垫料）对实验动物福利的影响,通过总结国内外的研究概况,旨为我国改善和提高实验动物的福利提出一些思路。     

Environmental determinants correlated to Vibrio harveyi-mediated death of marine gastropods

Vibrio harveyi is an emerging pathogen that causes mass mortality in a wide variety of marine animal species; however, it is still unclear which environmental determinants correlate V. harveyi dynamics and the bacterium-mediated death of marine animal life. We conducted a correlation analysis over a 5-year period (2003–2007) analysing the following data: V. harveyi abundance, marine animal mortality and environmental variables (seawater temperature, salinity, pH, chlorophyll a , rainfall and total viable bacterial counts). The samples were collected from a coastal area in northern Japan, where deaths of a marine gastropod species ( Haliotis discus hannai ) have been reported. Our analysis revealed significant positive correlations between average seawater temperature and average V. harveyi abundance ( R  = 0.955; P  < 0.05), and between average seawater temperature and V. harveyi -mediated abalone death ( R  = 0.931; P  < 0.05). Based on the regression model, n °C rise in seawater temperature gave rise to a 21 ⁿ -fold increase in the risk of mortality caused by V. harveyi infection. This is the first report providing evidence of the strong positive correlation between seawater temperature and V. harveyi -mediated death of marine species.     

Bleaching of Hermatypic Corals

In this paper, I review data on the magnitude and extent of reef coral bleaching events and consider modern hypotheses on the mechanisms of this natural phenomenon and experimental data lying at their basis. Four possible mechanisms of color loss by hermatypic corals have been confirmed experimentally: bacterial infection, change of zooxanthellae type in the polyps to improve the heat resistance of the photosynthetic function of coral to elevated seawater temperature, intoxication of zooxanthellae by animal metabolic wastes at high temperature and light levels, and thermal and photodestruction of the animal and algal cells. The heating effect of photosynthetic active radiation on the zooxanthellar cells in coral polyps was verified theoretically. The calculations showed that in the natural environment, the additional light-induced heating of zooxanthellae is not above 0.01°C and that it cannot cause disruption of the animal and zooxanthellae symbiosis.     

Torpor and hibernation in a basal placental mammal, the Lesser Hedgehog Tenrec Echinops telfairi

The patterns of heterothermy were measured in Lesser Hedgehog Tenrecs, Echinops telfairi, under semi-natural conditions in an outdoor enclosure during the austral mid-winter in southwestern Madagascar. The animals were implanted with miniaturized body temperature (Tb) loggers (iButtons) that measured body temperature every 42 min for 2 months (May and June). The tenrecs entered daily torpor on all 60 consecutive days of measurement, that is, on 100% of animal days, with body temperature closely tracking ambient temperature (Ta) during the ambient heating phase. The mean minimum daily Tb of the tenrecs was 18.44 +/- 0.50 degrees C (n = 174, N = 3), and never exceeded 25 degrees C whereas, apart from a few hibernation bouts in one animal, the mean maximum daily Tb was 30.73 +/- 0.15 degrees C (n = 167, N = 3). Thus during winter, tenrecs display the lowest normothermic Tb of all placental mammals. E. telfairi showed afternoon and early evening arousals, but entered torpor before midnight and remained in torpor for 12-18 h each day. One animal hibernated on two occasions for periods of 2-4 days. We consider E. telfairi to be a protoendotherm, and discuss the relevance and potential of these data for testing models on the evolution of endothermy.     

Skin temperature changes induced by strong static magnetic field exposure

High intensity static magnetic fields, when applied to the whole body of the anesthetized rat, have previously been reported to decrease skin temperature. The hypothesis of the present study was that in diamagnetic water, molecules in the air play significant roles in the mechanism of skin temperature decrease. We used a horizontal cylindrical superconducting magnet. The magnet produced 8 T at its center. A thermistor probe was inserted in a subcutaneous pocket of the anesthetized rats to measure skin temperature. Animals (n=10) were placed in an open plastic holder in which the ambient air was free to move in any direction (group I). Animals (n=10) were placed in a closed holder in which the air circulation toward the direction of weak magnetic field was restricted (group II). Each holder was connected to a hydrometer to measure humidity around the animal in the holder. The data acquisition phase consisted of a 5 min baseline interval, followed by inserting the animal together with the holder into the center of the magnet bore for a 5 min exposure and a 5 min postexposure period outside the bore. In group I, skin temperature and humidity around the animal significantly decreased during exposure, followed by recovery after exposure. In group II, skin temperature and humidity did not decrease during the measurement. The skin temperature decrease was closely related to the decrease in humidity around the body of the animal in the holder, and the changes were completely blocked by restricting the air circulation in the direction of the bore entrance. Possible mechanisms responsible for the decrease in skin temperature may be associated with magnetically induced movement of water vapor at the skin surface, leading to skin temperature decrease.     

Role of PPARα in control of torpor through FGF21-NPY pathway: From circadian clock genes to seasonal change and cardiovascular disease

Sleep and Biological Rhythms - In nature, hibernating animals experience fasting, cold temperature, and short day seasonally. Torpor is a state of decreased physiological activity in an animal,...     

A body temperature model for lizards as estimated from the thermal environment

A physically based model was built to predict the transient body temperature of lizards in a thermally heterogeneous environment. Six heat transfer terms were taken into account in this model: solar radiation, convective heat flow, longwave radiation, conductive heat flow, metabolic heat gain and respiratory energy loss. In order to enhance the model predictive power, a Monte Carlo simulation was employed to calibrate the bio-physical parameters of the target animal. Animal experiments were conducted to evaluate the calibrated body temperature model in a terrarium under a controlled thermal environment. To avoid disturbances of the animal, thermal infrared imagers were used to measure the land surface temperature and the body temperature. The results showed that the prediction accuracy of lizard's transient temperature was substantially increased by the use of Monte Carlo techniques (RMSE=0.59 °C) compared to standard model parameterization (RMSE=1.35 °C). Because the model calibration technique presented here is based on physical principles, it should be also useful in more complex, field situations.     

Interaction between thermal environments and hormones affecting skin-shedding frequency in the tokay (Gekko gecko) (Gekkonidae, Lacertilia)

Effects of thyroidectomy and/or hypophysectomy on the skin-shedding frequency (SF) in the tokay Gekko gecko and of thyroid hormones on the oxygen consumption (OCR) at various temperature regimes have been determined. Surgery invariably protracted the cycle length, thus decreasing SF; the extent of these changes was temperature dependent, the higher the temperature, the less the difference. Effects of hypophysectomy on cycle length were expressed in two phases; an extended first post-operative cycle was followed by a further extended second post-operative cycle, with cycle length forming a plateau thereafter. With time, the operated tokays would die without shedding during a greatly protracted cycle. OCRs in the tokay were temperature dependent, but between 28 and 34 degrees C, no significant difference could be seen. Effects of thyroid hormones on OCR were also temperature dependent. Furthermore, tokays having higher OCR were shown to have shorter cycles and vice versa. Results showed that whatever effect hormone(s) have on SF is indirect through general metabolic changes. SF is merely a reflection of the general metabolic status of the animal. It is proposed that the role of hormone(s), those of the thyroid in particular, is to act as "fine-tuning" devices in the regulation of metabolism and, as such, of the viability of the animal.     

Diet and temperature modify the relationship between energy use and ATP production to influence behavior in zebrafish (Danio rerio)

Food availability and temperature influence energetics of animals and can alter behavioral responses such as foraging and spontaneous activity. Food availability, however, is not necessarily a good indicator of energy (ATP) available for cellular processes. The efficiency of energy transduction from food‐derived substrate to ATP in mitochondria can change with environmental context. Our aim was to determine whether the interaction between food availability and temperature affects mitochondrial efficiency and behavior in zebrafish (Danio rerio). We conducted a fully factorial experiment to test the effects of feeding frequency, acclimation temperature (three weeks to 18 or 28°C), and acute test temperature (18 and 28°C) on whole‐animal oxygen consumption, mitochondrial bioenergetics and efficiency (ADP consumed per oxygen atom; P:O ratio), and behavior (boldness and exploration). We show that infrequently fed (once per day on four days per week) zebrafish have greater mitochondrial efficiency than frequently fed (three times per day on five days per week) animals, particularly when warm‐acclimated. The interaction between temperature and feeding frequency influenced exploration of a novel environment, but not boldness. Both resting rate of producing ATP and scope for increasing it were positively correlated with time spent exploring and distance moved in standardized trials. In contrast, behavior was not associated with whole‐animal aerobic (oxygen consumption) scope, but exploration was positively correlated with resting oxygen consumption rates. We highlight the importance of variation in both metabolic (oxygen consumption) rate and efficiency of producing ATP in determining animal performance and behavior. Oxygen consumption represents energy use, and P:O ratio is a variable that determines how much of that energy is allocated to ATP production. Our results emphasize the need to integrate whole‐animal responses with subcellular traits to evaluate the impact of environmental conditions on behavior and movement.     

Developmental testing of the Advanced Animal Habitat to determine compatibility with rats and mice

The Research Animal Holding Facility (RAHF) and the Animal Enclosure Module (AEM) have housed rats during Space Shuttle flights since the 1980s, but the operational constraints of the hardware have limited the scientific return from these Shuttle flights. The RAHF provides environmental control and monitoring for 24 rats with in-flight animal access, but it must be flown in the Spacelab. Due to the infrequent availability of Spacelab flights, rodent experiments rely heavily on the AEM. Unfortunately, the AEM supports only six rats, has no environmental control and provides no animal access in flight. The Advanced Animal Habitat (AAH) is being developed to support up to 12 adult rats or 30 adult mice for up to 30 days, provide active temperature control, animal telemetry and on-orbit video, record environmental parameters in the animal cage, and provide in-flight animal access in the Middeck, the Spacelab or the Space Station. To ensure the AAH can meet these requirements, animal testing is being conducted with rats and mice in every step of development. Testing began with the cage configuration.