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Cyproheptadine and LSD, two known antagonists of the peripheral effects of 5-HT, were administered i.v. to conscious rabbits at different times before the intracerebroventricular (i.c.v.) administration of 5-HT, NAD or dopamine. Cyproheptadine (which had a slight hypothermic effect) antagonized the rise in temperature induced by 5-HT; this antagonism was dose-related and appeared to be specific in that the hyperthermia induced by noradrenaline or dopamine was hardly modified. Interactions between LSD (which is hyperthermic alone) and 5-HT were more complex — both potentiation and depression being observed.

A number of diploid and polyploid species of wheat have been subjected to the condition of high temperature. The various temperature treatments have been found to induced formation of univalents in a number of Pollen mother cells of different varieties. The distribution of cells showing such univalents has been studied. It has been found that in almost all the plants, the distribution is of a poisson type. The significance of this type of distribution has been discussed.

Freshly prepared 2% acid and alkaline glutaraldehyde solutions were stored at 4, 20, and 37 C. At intervals, samples were removed and changes in pH, ultraviolet spectrum, and sporicidal activity (against Bacillus pumilus spores) were recorded. Alkaline solutions stored at 4 C showed little changes in these properties, whereas such solutions stored at 37 C became turbid and showed a decrease in pH, marked changes in ultraviolet spectrum, and an almost complete loss of sporicidal activity. Intermediate results were obtained with alkaline solutions stored at 20 C. In contrast, acid 2% glutaraldehyde solutions (initial pH 3.5) showed comparatively few changes in their properties. Treatment of spores with freshly prepared glutaraldehyde solutions (0.5%) at temperature above 40 C reduced the effect of pH on sporicidal activity.

Eggs from 25 parental pairs were reared at sustained temperatures from 20C to 34C, or were changed from 20C to 30C or vice versa al various developmental stages. Crowding, mechanical shoes, container type, amount of aeration, and malachite green prophylaxis did not alter numbers of vertebrae, and pectoral or dorsal rays; nor did these numbers vary between eggs laid on different days by the same parents. Numbers of anal and caudal rays were significantly different between sibling egg batches, and were decreased by crowded rearing conditions. Mechanical shock increased anal ray counts. Caudal rays were sometimes decreased by lack of aeration. Response of vertebrae to different sustained temperatures was U-shaped in nine groups, with nadirs varying from 24C to 32C; in two groups, vertebrae were progressively fewer at higher temperatures. Pectoral ray counts usually were progressively lower at higher temperatures. Dorsal ray counts of most formed arched curves. In all series, heritable variation at one temperature roughly equalled phenotypic variability between temperatures. Inherited differences in response patterns of different meristic series are largely independent of each other, and of mortality and of hatching time. Temperature breaks produced an overcompensation in vertebrae if applied early, or a paradoxical reaction if applied late.

1. The ether narcosis of five to seven hours' duration produces necessarily hyperglycaemia on normal and not fastened rabbits. The degree of hyperglycaemia depends upon the depth of narcosis. In cases of shallow narcosis, where muscle tone, pain sensitiveness and corneal reflex still existed clearly, the maximal blood sugar contents were 0.16-0.26%; in cases of deep narcosis, where these signs disappeared completely or nearly, the maximal blood sugar contents were 0.25-0.45%. The maximal points of the blood sugar content were reached in three to seven hours after beginning of etherization. Glycosuria occured in most cases; its severeness depended in general on the degree of hyperglycaemia (0.11-17%). After discontinuance of etherization the blood sugar increased slightly for a short time in many cases, but began sooner or later to decrease and returned in about five hours to its initial value. The chromaffine substance in adrenal glands reduced more or less by ether narcosis in nearly all cases, but never disappeared completely by ether narcosis of five to seven hours' duration. The body temperature fell and frequency of the respiration diminished. 2. The ether narcosis on normal rabbits with precaution against fall of the body temperature induced also hyperglycaemia of quite the same degree as on normal rabbits, contrary to “Fesselungsdiabetes.” Ether glycosuria diminished more or less by protection against fall of the body temperature. The course of hyperglycaemia and glycosuria during and after discontinuance of etherization was quite the same as on normal rabbits without the precautions. Reduction of chromaffine substance in adrenals was somewhat greater than on the parallel experiments. Frequency of respiration increased and half the number of the rabbits died. 3. Ether hyperglycaemia and glycosuria were produced on rabbits with bilateral splanchnectomy, though not greatly. The increase of the blood sugar content was 0.02-0.15%. Its degree depended upon the depth of narcosis. Chromaffine substance in adrenal glands did not reduce. Fall of the body temperature was as on normal rabbits. The ether narcosis on rabbits with bilateral splanchnectomy under precautions against fall of the body temperature induced also hyperglycaemia of quite the same degree on the similarly operated rabbits without protection against fall of the body temperature. Glycosuria diminished more or less. In most cases no change in the chromaffine substance content in adrenals. 4. Ether hyperglycaemia and glycosuria were produced on rabbits with unilateral splanchnectomy nearly the same as on normal rabbits. Ether hyperglycaemia and glycosuria on rabbits with unilateral splanchnectomy are quite the same as those on normal rabbits. In cases of shallow narcosis, maximal blood sugar contents were up to about 0.2%; no glycosuria. In cases of deep narcosis, they were 0.3-0.4% and more, and glycosuria occured also. Chromaffine substance in the adrenal gland on the side with the intact splanchnic nerve was reduced, while it never happened in the adrenal gland on the side with splanchnectomy. Quantity of the urine, frequency of respiration, fall of the body temperature and paradoxical pupillary reaction were as on normal rabbits.

A series of 32 patients treated by diathermy in conjunction with chemotherapy is presented. The clinical outcome of 28 completed cases is described. The clinical course and post mortem findings of a case which died during treatment are outlined. Evidence that certain patients are susceptible to the elevation of temperature induced by diathermy is offered.

The cold resistance of deer mice captured during the winter was greater than that of summer mice and was accompanied by a greater pelage insulation and a lower oxygen consumption at 1–2 °C. On the other hand, the enhanced cold resistance of deer mice previously acclimated to cold was not accompanied by differences in pelage insulation. Moreover, in white-footed mice previously acclimated to different temperatures, oxygen consumption was similar at 1–2 °C. These data indicate that the seasonal changes observed in Peromyscus are not identical to changes produced by acclimation in the laboratory. Environmental factors responsible for these differences are discussed.

The polymorphic behavior of a commercial monoglyceride emulsifier together with a liquid vegetable oil and water has been investigated by means of microscopic examination and differential scanning calorimetry. The results show that the stability regions of the liquid crystalline phases formed are highly dependent on the temperature and related both to the solubility of the monoglyceride emulsifier in the oil phase and to its polymorphic behavior. The formation and stability of emulsions are discussed in connection with the results obtained.

SUMMARYThe modifications of the plastid structures in a Maize mutant, « golden-leaf », have been studied in the electron microscope. In this mutant plastid organization is temperature dependent. At 25°C the chloroplasts are quite regularly structured, but when the corn plants are transferred to 16°C, the plastids become incompletely organized or anomalous. If higher temperature conditions are re-established, the plastids are able to regain their original organization only if a prolamellar body or structured grana, even in an anomalous state, are present. When the plastids are affected by the lower temperature in a very young stage, their modifications become irreversible, and their appearance resembles, also in the regreened tissues, that of albino plastids or of chromoplasts.

Temperature-mediated changes in the kinetics of enzyme catalysed reactions can be due to effects on a number of different parameters. If the change in temperature does not (a) inactivate the enzyme, (b) alter the affinity of the enzyme for the substrate, an activator or an inhibitor or (c) alter the pH function of the reaction components, the velocity of enzyme catalysed reactions increases with increasing temperature. The relationship between the velocity of reaction and temperature can be expressed either as the activation energy (E) or the temperature coefficient (Q10). Both expressions can be derived from the empirical Arrhenius equation relating the velocity of reaction and temperature $$\frac{\alpha \ln k}{\alpha T}=\frac{E}{R{{T}^{2}}}$$ (1) where k is the reaction velocity constant, R the gas constant, T the absolute temperature and E a constant, subsequently called the activation energy (also written as A or μ.). Integration of equation (1) gives $$\ln \frac{{{k}_{2}}}{{{k}_{1}}}=\frac{E}{R}\left( \frac{1}{{{T}_{1}}}-\frac{1}{{{T}_{2}}} \right)$$ (2) from which it can be seen that the value for E can be obtained from the slope of the straight line when logk is plotted against 1/T $$E=2\cdot 303R\times slope$$ $$\therefore E=4\cdot 576\times slope \left( where R=1\cdot 987 cal/mole/{}^{\circ }K \right)$$

Merremia gangetia Linn. (Cuf) is one of the most important weeds invading cultivated lands of India. Temperature, both high (45° C) and low (15° C) exhibit a definite role in development of the weed, particularly during germination. Higher tempeeratures (45° C) during dry storage appeared to be the main factor in laboratory experiments as well as in nature. Low temperature induced secondary dormancy and its removal by incubation at 35° C helps to explain the ecological mechanism through which the weed endures winter conditions. Germination of buried seeds confirm that the atmospheric conditions were found to be more effective in upper layers of soil. Ecological adaptations of this weed via germination requirements are assessed in the paper.

‘Grand Rapids’ lettuce. seed will not germinate in darkness at 30°. An exposure in temperatures between 5°C and 25°C for a short period after the initiation of germination can effectively overcome the high temperature imposed dormancy. If the exposure to low temperature is from the beginning of germination it is less effective. The low temperature induced germination is not reversed by far red light of 725 nm and seed not responding to the low temperature do respond in a classical fashion to red and far red irradiations. It is considered that the results justify acceptance of the hypothesis that an inhibitor of germination is produced during the initial stages of germination and that this formation is strongly temperature dependent so that there is much accumulation. At low temperatures an alternative metabolic pathway predominates leading to the production of an essential metabolite. At high temperatures this metabolite is produced from the inhibitor (or inert compound) by a mechanism under the control of the phytochrome system.

The effect of non-chiralic solute molecules on the pitch of cholesteric mixtures of cholesteryl chloride and cholesteryl nonanoate has been studied as a function of the composition and the temperature. The occurrence of a pretransition to the smectic state at low CC content is established. In the pretransitional state the pitch decreases exponentially with increasing temperature and is extremely sensitive against the addition of most organic molecules. In the normal cholesteric state the pitch increases with increasing temperature. In this state only a very limited number of nonchiralic molecules exert an appreciable influence on the pitch.

The boundary conditions at the surface of a small bubble rising in a liquid are examined theoretically, and it is shown by order-of-magnitude arguments, which are confirmed by detailed calculation in a special case, that although surfacetension gradients must always exist around the bubble, they are too small to affect the motion appreciably unless surface-active substances are present. This is because gradients of surface tension imply gradients of temperature in a pure liquid, and these turn out to be always small near the bubble if they tend to zero at large distances from it. The same is true for drops of one fluid in another.

C57 black male mice about 100 days of age were exposed to elevated temperature of 35 deg C and 70% humidity in four exposure periods totaling 61 hr distributed over 4 days. Animals were sacrificed at 3, 5, 7, and 10 days atfer the end of the heat treatment. Results of the heat treatment were compared with those following 1000 r x irradiation. The damage inflicted on the mouse testis by this heat treatment differed fundamentally from that induced by 1000-r acute localized x irradiation. Comparison at 10 days after treatment was especially revealing. Elevated temperature induced the formation of giant cells, originating either from karyokinesis without cytokinesis or from agglomeration. The latter condition was most predominant when spermatozoal heads with indistinct tails were involved. No giant cells were seen after x irradiation. Spermatogonia sur vived the heat treatment so that after 10 days recovery was in full swing. X rays killed spermatogonia with the exception of occasional type A cells. Recovery had not started after 10 days. Late spermatocytes became pycnotic as a result of heat treatment. Of these, some regressed and a few underwent restitution or C-division. Normal spermatids were not formed. Late spermatocytes were blocked by 1000-rmore » x irradiation. The block was so persistent and so severe that 76% of the tubular cross sections seen at 10 days contained some form of restituted or regressed spermatocytes. Ten days after heat treatment no restituted or regressed spermatocytes were seen. This may be related to the fact that heat seems to be less damaging than x rays to the emptying mechanism of tubules. Spermatids appear equally damaged by heat and by x rays. Spermatozoal heads are more common at 10 days after x irradiation than after heat treatment. This may result from the lesser effect of heat on the emptying mechanism as well as from a qualitative difference in the damage inflicted. (auth)« less

Low-temperature (10 °C) treatments alternated with periods at room temperature (25 °C) were found to induce grossly abnormal kinetochore orientation behaviour during metaphase I in spermatocytes of the grasshopper Melanoplus differentialis. These orientation abnormalities involved multiple reorientations before a stable bipolar co-orientation was finally achieved. Similar orientation abnormalities have been induced in the past by heat-treatments in the locust Schistocerca. The unstable orientation behaviour of bivalents in eight cold-treated living spermatocytes was analysed with the aid of time-lapse cinematographic records. Analyses made included the relationship between kinetochore position within the spindle and reorientation, the frequency of reorientation and the velocity of chromosome motion after reorientation. It had been shown previously, in untreated cells, that physical tension applied by micromanipulation could stabilize experimentally induced unipolar bivalents and inhibit their reorientation. Two experiments of this type with cold-treated spermatocytes were successful in demonstrating the importance of tension in the maintenance of stability, even in unstable, cold-treated material. In discussing the interpretation of these results it is proposed that bivalents have an inherent tendency to reorient periodically. In untreated cells the time between reorientations is long enough to enable interkinetochoric tensions, and resulting stable bipolar orientation, to be achieved, but in cold-treated cells this time is reduced, thereby hindering the establishment of tension and stability.

The Hugoniot of wrought tungsten which was 99.6% of the crystalline density and 99.92% pure has been determined to 80 kbar at room temperature and at 950°C. Measurements of the stress‐particle velocity relationship were made by impacting a sapphire‐faced quartz gauge assembly onto the tungsten sample. In the room temperature experiments, transmitted wave profiles were determined with quartz gauges. At room temperature, the elastic wave velocity was 5.22±0.05 mm/μsec and the Hugoniot elastic limit for 9.5 mm thick specimens was 37.7±0.8 kbar. The stress‐particle velocity Hugoniot at 950°C, while nearly parallel to the room temperature Hugoniot, was displaced about 15 kbar downward due to a decrease in the Hugoniot elastic limit at this temperature. This decrease is associated with a temperature induced brittle‐ductile transition. The application of these data in calculating the Gruneisen parameter is discussed.

Temperature-induced humidity errors in the carbon humidity element ML-476 are described. The dominant error is caused by solar irradiation and results in a lowering of reported humidity values. The effect was found with both the military AN/AMT-12 and weather Bureau radiosondes. Flight studies indicate that a significant improvement in data acquisition will result from a blackening of the sensor channel walls.

A modification to the radiosonde humidity channel to eliminate a temperature induced bias is described. Data are presented from Right test comparisons of radiosondes so modified and standard unmodified radiosondes. It is anticipated that the redesign of the current, standard radiosondes will reflect essentially the modifications described herein and consequently the data indicate the type and magnitude of change in the reported humidifies which may be expected. The data are essentially in agreement with predicted changes from a previous paper (Morrissey and Brousaides. 1970). Further field testing of this and other modifications is proposed to determine residual error. Similar tests to standard instrumentation would permit corrections to archived data.

Frame‐camera interferogram data for a neodymium‐doped glass rod taken during the laser pumping process have been analyzed in terms of changes in optical path length due to: (1) explicit temperature‐induced changes in length and index of refraction, and (2) temperature‐induced stress birefringence. Criteria for compatibility of the interferogram data, the formalism, and independently determined values for the phenomenological constants involved are set up and met, after which the temperature over the rod cross section obtains. The minimum in the temperature distribution found accounts for the observed split fringes, and our qualified estimate of the temperature rise at the center of the rod is ∼16°C. Estimates of the changes in optical path length due to the various effects are made, and values for the temperature coefficients of expansion and refractive index of 0.97×10−5/°C±6% and −7.2×10−7/°C±60%, respectively, are submitted.

Continuous temperature monitoring was carried out with thermistor probes implanted in breast tumours and in normal breast tissue. The results indicate that an initial rise in tumour temperature induced by the administration of nor-ethisterone acetate is associated with a subsequent objective response to that agent, whilst a fall has the reverse implication. Circadian rhythm has been demonstrated in all of the normal breasts and in all the tumours. It is suggested that skin temperature measurements above the tumour do not accurately relate to temperature within the tumour unless there is skin involvement. Considerable variation with time has been demonstrated in the tumour-normal temperature differential. This casts doubts upon the diagnostic value of the “normal” thermogram when taken as an isolated measurement. It may also tend to obscure any relationship between the degree of tumour temperature elevation and prognosis. We have now extended this investigation to include the effect of radiation to the cervix on temperature patterns in that site.

The influence of local temperature changes within the posterior portion of the body on dorsal aorta blood flow (\(\dot Q_{da} \)), femoral arterial pressure (Pa), peripheral resistance (R), skin blood flow (\(\dot Q_s \)) and skeletal muscle blood flow (\(\dot Q_m \)) was examined in unanesthetized lizards (Iguana iguana andTubinambis nigropunctatus). In response to local heating of the hind legs and tail\(\dot Q_{da} \) and\(\dot Q_s \) increased,Pa was generally unchanged,R decreased and\(\dot Q_m \) decreased or was unchanged (Fig. 2). It is suggested that the acquisition of heat may be favored by diverting the increase in\(\dot Q_{da} \) away from the muscle to the warmer skin. In response to cooling\(\dot Q_{da} \) and\(\dot Q_s \) decreased,Pa was generally unchanged, R increased and\(\dot Q_m \) increased or was unchanged. Hence, during cooling the retention of heat may be favored by diverting blood away from the skin to the deeper muscle. The muscle-skin shunt is under sympathetic control since following blockade with phenoxybenzamine HCL (Dibenzyline) muscle blood flow changes in response to temperature were qualitatively similar to those of skin (Fig. 4). These changes in peripheral circulatory patterns are independent of changes in heart rate or deep body temperature.

Heat production and thermal insulation were measured in three groups of sheep, control, outdoor, and indoor, which were exposed to the effects of season, cold climate, and cold temperature respectively. The experiment was for 24 weeks, from November 1967 to April 1968. Sheep in the control, outdoor, and indoor groups gained 16.2, 10.0, and 14.9 kg respectively. Average feed intake in both control and outdoor groups was 2.65 kg hay/100 kg sheep per day. Food intake was highest in the indoor group and was inversely related to ambient air temperature. Resting heat production was constant throughout in the control group but increased with time in the outdoor group. Resting heat production in indoor sheep was related to intensity of prior cold exposure. Wool growth and thermal insulation did not differ significantly between groups. Critical temperature for the outside group fell from −15 °C in week 4 to −35 °C in week 20. After these trials, all sheep were shorn. The heat production of the shorn indoor group at −30 °C was greater, and that of the outdoor group was less than that of the controls. The results suggest that, in sheep, acclimation to cold temperatures induces rapid, brief increases in resting heat production and summit metabolism. Acclimatization to cold climates slowly induces a persistent elevation in resting heat production, but appears to reduce the initial metabolic response to an intense cold stimulus.

The larvae of 26 species ofAedesfrom Manitoba were reared at constant temperatures from a low of 10° or 15°C, to the upper lethal temperature. Various grades of adult intersexes occurred in 12 univoltine species. The lowest threshold temperature for intersex development was found inA.communis(19°C); the highest inA.fitchii(29°C). A constant rearing temperature of 30°C was lethal for all fully univoltine species from Manitoba. The zoogeographical significance of the distribution of species in North America is discussed with regard to their intersex threshold temperature.

Specimens with 18 ppm and 100 ppm carbon of different orientations were deformed by compression (έ∼1·1×10−4 s−1) at the temperatures 150 °K, 195 °K, 293 °K, 393 °K and 483 °K. The measuredΨ(χ) andτ(χ) curves are presented. The changes of the curves caused by increased carbon content are discussed from the point of view of the low temperature induced cross-slip. Deviations from the Schmid law of critical resolved shear stress are found for both carbon contents. The dependence of the CRSS on temperature for specimens of standard purity has a slightly different course for orientationχ=−30° than for orientationsχ=0° andχ=+30°. These deviations are discussed in terms of the influence of normal stress on the slip. The course ofΔτ (difference between the CRSS in the MRSS plane for specimens with 100 ppm and 18 ppm of carbon) onχ is discussed using different models of lattice hardening due to interstitial impurities. These models can also be applied to the explanation of deviations ofτ(χ) curves from the Schmid law.

The warming of a vitreous solution from liquid nitrogen to room temperature, induces an important increase in the delayed fluorescence of the aromatic solute. It is suggested that this increase arises from molecular diffusion in the softening solvent.

The purpose of this experimental study has not been to investigate the pathological changes which could be produced by lethal doses of artificially induced fever, as has been done previously by Hartman, Jacobsen and Hosoi, Baldwin and Nelson, and a few others,1 but to make a quantitative comparison between the organ changes occurring in fatal and non-fatal doses of fever, and to investigate the fate of these changes after recovery of the animal. In our series of experiments male adult rabbits of a healthy standard breed were used. Nine animals died after a rapid high rise of temperature induced by the diatherm or radiotherm in a short period of 30 minutes (Group A); 9 animals succumbed to a fever of 108° to 109° in a time interval from 8 to 9 hours (Group B); 5 animals were kept at a temperature of 107° until death occurred after an estimated time of about 40 hours (Group C); and 5 animals were exposed once a week 6 times and killed by air embolus one week after the last exposure. Twelve animals served as...

In the waterbugs Cenocorixa bifida and C. expleta, insects that develop in the fall show an arrest in the development of the mesothoracic indirect flight muscles. This developmental arrest continues throughout the winter and in specimens maintained at 5°C. If insects of either species are held at 15°C continuously for more than 24 hr, muscle development is initiated.

クルマバツクバネソウの還元分裂を低温または高温の条件で進行させ, その第一中期における染色体の形態的変化を観察して次の結果をえた.1. 0°C の低温処理では真正染色質部分と異質染色質部分に相違が現われた. 前者はラセンの直径の増大に伴う長さの短縮が, 後者はラセンの直径の減少に伴う長さの伸長が見られた. すなわち, 還元分裂染色体においても体細胞染色体と同様, 低温処理によって真正染色質部分と異質染色質部分を区別できることを実証した.2. 20°Cの高温処理の場合には染色体は対照区のものよりやや伸長する傾向が見られたが, 真正染色質部分と異質染色質部分の相違は現われなかった.

Polarization of the fluorescence of alcohol and glycerine solutions of phthalimides was studied over a wide temperature range as a function of the wavelength of the exciting light. The maximum polarization reaches nearly 50% at sufficiently low temperatures and with long-wave excitation. There is a discussion of the possible sensitivity of the P = f(vexc) dependence to overlap of the first and second absorption bands and to the duration of the excitation at various exciting wavelengths.

Carbon films deposited on pyrex, silica and alumina substrates have free spin concentrations similar to those found for chars. The results of heat treatment show that a maximum in the spin concentration occurs at a heat treatment temperature of about 150°C and that when silica and alumina substrates are employed a second maximum in the spin concentration occurs at 500°C. The second spin production process is considered to originate in the evolution of water and hydrogen from the substrate and to lead to a high concentration of spins at the surface. Line width and line shape analysis suggests that considerable exchange narrowing occurs in films. Activation energies for spin production and destruction over the temperature range 55–314°C increase with extent of reaction. The original spin centres are taken to be unsatisfied sigma valencies situated on the periphery of carbon aggregates in strained regions of the film. The spin destruction process suggests that such centres link up with others by temperature induced release of strain.

A study has been made on the effect of emulsification temperature and cooling rate on certain physical properties of a beeswax-mineral oil emulsion. The emulsion, which was prepared at five temperatures and cooled at three rates, was evaluated for plastic viscosity, thixotropy, yield value, water separation rate, and initial average particle size. It was shown that both the emulsification temperature and cooling rate significantly altered these properties.

1. In normal rats intraperitoneal as well as intravenous in jections of Pitressin and synthetic lysine vasopressin caused a prompt fall in the rectal temperature. Pitocin and Syntocinon had no effect on it.2. Intracarotid infusion of 8.5 per cent sodium chloride and 2 M sucrose solutions resulted in a lowering of the rectal temperature in normal rats, but not in neurohypophysectomized ones. Intravenous infusion of the hypertonic solutions and intracarotid infusion of isotonic solutions did not cause any change in the rectal temperature.3. Exposing neurohypophysectomized and totally hypophysectomized rats to a high ambient temperature of 40°C for 40 minutes resulted in a similar rise of the rectal temperature in extent and mode to that in normal ones. In rats with anterior hypothalamic lesions the rectal temperature rose to a higher level over 41°C on exposure to the same heat conditions.4. Subcutaneous injection of Pitressin tannate in oil caused a prolonged fall in the rectal temperature, but it did not exhibit any suppressing effect on the elevation of rectal temperature either in normal or in neurohypophysectomized rats which were subjected to heat exposure.5. No difference was observed between intracarotid and intravenous route of Pitressin administration in the extent and the time course of the fall in the rectal temperature.6. The fall in the rectal temperature following intravenous infusion of Pitres-sin was not modified by electrolesions in the anterior hypothalamic area, neurohypophysectomy and total hypophysectomy.7. Neither treatment with Dibenzylin nor atropine affected the body temper-ature lowering effect of Pitressin.

The influence of temperature upon sulphide formation was investigated with sediment sulphureta incubated at constant temperatures in the laboratory. The concentrations of sulphate, sulphide and pyrite were periodically measured and it was found that, in addition to a decrease in the rate of sulphide formation with temperature, there was a changes in the origin of the sulphide. Thus, at 5° and 10°C, the majority of sulphide originated from organic sulphur, while sulphate contributed the greater proportion of the sulphide at 20° and 30°C. Such changes presumably reflect those in the natural enviroment during winter and summer.

1. 1. The motoneuron firing patterns recorded from the trochanter of the last leg of the carabid beetle, Pterostichus brevicornis , were studied during varying states of temperature acclimatization and acclimation. 2. 2. Individual units were found to vary in both the range of temperature-dependent discharge and extinction points. Absolute neural extinction varied with previous thermal conditioning: i.e. 0°C during warm adaption to −11·7°C during cold adaptation. 3. 3. Coordinated neuromuscular activities were observed above extinction temperature.

ted in the temperature of the blood in the right auricle. The present experimental data coccerning right heart blood temperature are given with special reference to the amplitude and duration of changes in this temperature induced by pooling blood in the lower limbs.

The spectral distribution of scattered light is calculated for the model of a liquid in which the bulk and shear relaxation processes are each characterized by a multiplicity, or a continuous set, of relaxation times. The treatment is a generalization of that given by the authors previously [Phys. Rev. 173, 231 (1968)] in which bulk relaxation was ascribed to the relaxation of a thermodynamic order parameter relaxing with a single relaxation time. It is found that, in general, one has to introduce two independent distribution functions associated with the bulk relaxation times. Only when all the bulk relaxation processes are of the same type (pressure induced, temperature induced, etc.), does the expression for the spectral function contain just one distribution for bulk relaxations. This is in contrast to the results obtained by previous workers and may have significance in relation to a reported discrepancy in interpreting (in terms of a single distribution function for bulk relaxation) experimental dat...

Structure of nonionic surfactant diglycerol monomyristate (C14G2) micelles in cyclohexane has been investigated by small-angle X-ray scattering (SAXS) technique. Structural modulation of reverse micelle (RM) has been systematically studied by changing composition, temperature change and added-water. The SAXS data were evaluated by the generalized indirect Fourier transformation (GIFT) method, which gives pair-distance distribution function (PDDF). Unlike conventional poly(oxyethylene) type nonionic surfactants, C 14 G 2 forms RM in cyclohexane without water addition at normal room temperature. A clear indication of one dimensional (1-D) micellar growth was found with increasing C 14 G 2 concentrations. On the other hand, temperature induced cylinder-to-sphere type transition in the RM structure. The maximum dimension and the cross-sectional diameter of the RM increased upon addition of trace water indicating the formation of water pool in the reverse micellar core. Keywords: Diglycerol monomyristate, small-angle X-ray scattering, reverse micelles. DOI: 10.3126/jncs.v23i0.2099 J. Nepal Chem. Soc. , Vol. 23, 2008/2009 Page: 74-81

Marquillo × Kenya Farmer 1 (Mql × KF 1) wheat plants respond to very short 16° treatment by decreased meristematic activity of the apical meristem and extensive cellular destruction in young leaf and stem tissues. By radiotracer techniques the metabolism of 3H-thymidine, 32P, and 14C-leucine fed to intact shoot tissues of Mql × KF 1 and normal Marquillo (Mql) plants were studied.Immediately after the onset of 16° treatment, the incorporation of both 3H-thymidine and 32P into the DNA of Mql × KF 1 meristematic regions began to decline rapidly although the total uptake of label into the meristematic tissue remained constant. The incorporation of 32P into the RNA, the acid-soluble organic phosphate compounds, and phospholipids of the Mql × KF 1 meristems also declined during the first 24 h and the inorganic phosphate radioactivity increased. After the initial decrease, the proportion of radioactivity in the RNA and acid-soluble organic compounds increased to near control levels. The distribution patterns of both 3H-thymidine and 32P were unchanged in the meristematic region of Mql × KF 1 plants at 26° or Mql plants at 16° or 26°. Protein synthesis in meristematic regions, measured by the incorporation of 14C-leucine, responds to temperature similarly in Mql × KF 1 and Mql plants.The inhibitions of mitosis, phospholipid synthesis, and DNA synthesis were extremely rapid and reversible after short 16° exposures, and are thought to be close to the primary process of temperature lethality of Mql × KF 1 plants. Although it is not known if any of these processes are responsible for the others, it is proposed that the cellular destruction is caused by the inability of cells in the elongating regions to synthesize the phospholipid components of membranes.

An appraisal is made of linear elastic fracture mechanics (LEFM) as a method of fracture-safe assurance for carbon and low-alloy steels. The theoretical advantage of an exact flaw size-stress level relationship offered by LEFM is contrasted with the limitations posed in actual application. These limitations relate to statistical variations in KIc and KId data. The variations considered here are (a) data scatter at a given temperature, and (b) toughness variations between different heats of a given alloy. In an engineering context, LEFM is considered applicable only in the temperature region representing the initial development of the brittle-ductile transition that characterizes low-alloy steels. In this region statistical variations in the data suggest that critical flaw sizes could be significantly smaller than the values calculated on the basis of limited experimental data. The prime objective in determining fracture toughness is for use in evolving a fracture control plan that assures structural integrity under a variety of environmental and loading conditions. Often the exact flaw size is unknown, particularly if the structure has not yet been built. Since the toughness increases sharply in the transition region, a practical solution is to take advantage of this behavior and choose a minimum operation temperature that assures a high fracture toughness such that postulated flaws cannot propagate in an unstable manner. The objective of being able to define the temperature range and statistical distribution of KId curves is met equally by the use of Dynamic Tear (DT) and KId tests. The DT test, as contrasted with LEFM methods, is shown to be an effective engineering tool with which to determine the Fracture Transition Elastic (FTE) temperature; above this temperature, plane strain constraint is lost for the given thickness, and flaws cannot propagate at stress levels less than yield. The determination of a minimum structural operating temperature based on dynamic LEFM values, when modified by conservatisms necessitated by statistical variations in the data and inaccuracies in temperature measurement, is shown to be essentially equivalent to the FTE temperature.