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1.
1.  At ambient temperatures (T a) between 39 and 43°C, specimens of the waterproof treefrogChiromantis xerampelina, resting quietly in wind tunnels, adjust rates of evaporative water loss (EWL), maintaining body temperature (T b) 2–4°C belowT a.
2.  Brain heating and cooling, respectively, increased and decreased steady-state rates of thermoregulatory evaporative water loss (EWL), driving negative feedback changes inT b.
3.  Continuous infusions of epinephrine resulted in specific, dose-dependent, saturable increases in EWL; isoproterenol was more potent than epinephrine, which was more potent than phenylephrine. Tyramine injection also stimulated EWL.
4.  Non-specific increases in EWL stimulated by injections of cholinergic agonists were weakly antagonized by atropine, but thermally induced EWL, as well as adrenergically and cholinergically stimulated increases in EWL, were abolished by beta-adrenergic antagonists.
5.  Sweating decreased andT b increased during ganglionic blockade.
6.  The observations suggest thatC. xerampelina controls thermoregulatory EWL by modulating the sympathetic nervous outflow stimulating beta-adrenergic receptors on cutaneous mucous glands.
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2.
1.  Physiological adaptation to hypothermia were studied in newly hatched great snipe chicks (Gallinago media) by measuring oxygen uptake (VO2), heart rate (HR), respiratory frequency (RF), and body temperature (Tb) at different ambient temperatures (Ta).
2.  Tb of 1-day-old chicks at Ta of 35°C stabilized at about 40°C. At Ta between 20 and 30°C the chicks maintained a Tb about 8°C above Ta. Hatchlings maintained a higher gradient when active than when resting. Below 20°C they were unable to maintain a stable Tb.
3.  In resting hatchlings VO2 was similar at Ta between 35 and 20°C (Tb 40–30°C), VO2 range 1.7–2.5 ml·g-1·h-1. Below 20°C, VO2 declined with time.
4.  The HR of 1-day-old chicks fell linearly with Tb during cooling. The Q10 of the HR was 1.7 at Tb 38°C and increased to 3.0 at 29°C. The RF showed a slight tendency to decrease with decreasing Tb.
5.  It is concluded that the ability to maintain normal dexterity at low Tb is an important aspect of snipe survival strategy. Maintaining a temperature gradient rather than a constant high Tb presumably saves energy. It is suggested that the mechanisms whereby VO2 is maintained at a low Tb may involve isoenzymes and adaptations of the nervous system. However, such adaptations would not seem to affect the pacemaker mechanism as evidenced by the high Q10 of the HR.
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3.
1.  The noninvasive techniques of intracellular optical physiology were used to measure reflectance changes in the deep pseudopupils of various regions of the apposition compound eyes of 3 species of stomatopod crustaceans.
2.  Upon exposure to light, prominent changes in reflectance were observed in all eye regions of all species studied. Generally, the response was an increasing reflectance following stimulus onset; however, in the lateral rows of the central ommatidial band of gonodactyloid stomatopods, the response was a rapid decrease in reflectance. Halftimes for the normal, increasing response were about 5 s in the gonodactyloid species and an order of magnitude longer in the squilloid species.
3.  The reflectance changes were probably produced by pupillary mechanisms similar to those previously described for insects. Evidence for this included the form and speed of the response, the observation that fluorescence from the visual pigment diminished with a similar time course to the increase in reflectance, and the tendency of the response to sensitize to repeated stimulation.
4.  Two spectral classes of photoreceptor were distinguishable in both the peripheral and central band regions of the eye. These classes were most sensitive to ultraviolet (360 nm) or long-wavelength (500 nm) light. The classes were distinguishable by the form and speed of the reflectance changes they produced when stimulated. Results of univariance experiments suggested that only these 2 classes existed in each eye region examined.
5.  In all species and ocular regions examined, the reflectance-change response operated over an intensity range of 3–4 orders of magnitude.
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4.
The effects of temperature, over the range 10–40 °C, on properties of locust (Schistocerca gregaria) ocellar L-neurones and of their interconnections have been investigated. At cooler temperatures, a small change in temperature has a larger effect than an equivalent change at warmer temperatures. An increase in temperature leads to the following:
1.  A decrease in input resistance, which typically halves in value as temperature increases from 15 °C to 35 °C. When synaptic transmission between photoreceptor cells and L-neurones is blocked with cobalt, temperature still affects L-neurone resistance. The membrane time constant also decreases, but the resting potential is unaffected.
2.  An increase in the sizes of rebound spikes, which are produced when hyperpolarizing pulses end. Above 35 °C, the maximum size of rebound spike is smaller than that at cooler temperatures.
3.  A decrease in the latency to response to light, and an increase in the speeds of the transient responses to changes in light.
4.  A decrease in the latency of transmission at both excitatory and inhibitory synapses between L-neurones.
5.  At excitatory synapses between L-neurones, an increase in the postsynaptic current. This is compensated by a decrease in postsynaptic membrane resistance, so that there is little effect on the size of the postsynaptic potential.
6.  At inhibitory synapses between L-neurones, a decrease in the time for the postsynaptic potential to reach its peak. The time for recovery of transmission at inhibitory synapses is unaffected by temperature.
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5.
1.  At 28°C conversion efficiency of total nitrogen (TN) was inversely related to size.
2.  In the pre-adult stage protein nitrogen (PN) conversion efficiency was high whereas in the Post-adult stage non-protein nitrogen (NPN) conversion efficiency was high.
3.  Lower temperature (20°C) was not congenial for PN conversion.
4.  Higher temperature favoured PN conversion for smaller fish but NPN for larger fish.
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6.
1)  Male Heliothis virescens moths flew upwind to pulsed pheromone plumes. Upon truncation of the pulsed plume males flew into clean air, turning their tracks crosswind (> 60° relative to directly upwind direction at 0°) within an average of 0.27 s, and were casting, perpendicular to the wind-line (90°), within 0.43 s.
2)  The characteristic casting flight in clean air consisted of left-right crosswind reversals, continuing for many seconds without further pheromonal stimulation. Males intercepting a single strand of pheromone during casting flight responded by surging upwind (track angles < 60°).=" the=" phasic=" surge=" lasted=" only=" 0.38=" s=" before=" reverting=" to=" crosswind=" flight=" (="> 60°).
3)  Average templates of responses in two and three dimensions were created. Males controlled their vertical deviations very tightly when in contact with pheromone but upon entering clean air, lateral and vertical excursions became much greater.
4)  Males failed to sustain upwind flight to repetitively pulsed plumes generated at < 4=" filaments/s.=" at=" the=" threshold=" frequency=" of=" 4=" pulses/s=" we=" show=" that=" upwind=" flights=" were=" composed=" of=" reiterated=" surges=" followed=" by=" crosswind=" casting.=" as=" the=" pulse=" frequency=" increased,=" the=" tracks=" became=" straighter=" and=" the=" single=" filament=" cast-surge-cast=" template=" could=" be=" viewed=" only=" sporadically=" when,=" for=" example,=" a=" male=" apparently=" failed=" to=" intercept=" filaments.=">
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7.
1.  The overall rate of feeding at 28°C bears an inverse relationship to size; the time course of feeding appears to be size-independent and shows a decline with increase in time.
2.  Absorption efficiency is independent of size.
3.  The rates of absorption and conversion and conversion efficiency are inversely related to size.
4.  The rate of feeding is reflected on the rates of absorption and conversion.
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8.
1.  Under laboratory conditions complete development of H. sparsutum is shown within a temperature range of-0.7°C to +8°C. Constant temperatures above 10°C are lethal to the population. Larval growth (L1 to L5) is strictly temperature-dependent between-0.7 and +3.5°C, but slightly temperature compensated between +3.5 and +8°C.
2.  Rate of egg production is highest at an average daily temperature of-0.7°C.
3.  The sixth larval stage (L6) can be subdivided into a wandering and feeding period of about 40 days (at 7.3°C) and a following prepupal resting stage (PPR) with a high variability in duration, even at one and the same temperature, which ends with pupation.
4.  Entrance into this resting stage seems to be independent of environmental changes and can occur at every time of the year. Termination of the PPR depends upon light stimuli received during the entire larval period.
5.  Readiness for pupation exists when the photoperiod in the PPR exceeds that during hatching of first larva. A decreasing photoperiod during PPR triggers pupation in prepupae of various age.
6.  The diapause stage seems to be a primary factor synchronizing the life cycle with seasonal changes in the environment.
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9.
Twelve of the main European LCA software packages currently available are examined wirh the aim of establishing which are the most appropriate for LCAs on industrial processes. The packages performances are assessed in terms of
–  • Volume of Data
–  • WindowsTM environment
–  • Network Capabilities
–  • Impact Assessment
–  • Graphical representation of the inventory results
–  • Sensitivity analysis
–  • Units
–  • Cost
–  • User Support
–  • Flow Diagrams
–  • Burdens allocation
–  • Transparency of data
–  • Input & output parameters
–  • Demo version
–  • Quality of data
The review concludes with a Specification Table which summarises the facilities available on each software package. The general conclusion from this study is that for industrially based LCAs, there are four packages which may offer advantages over the rest. These are The Boustead Model, The Ecobilan Group’s TEAM™, PEMS 3.0 and SimaPro 3.1.  相似文献   

10.
1.  The ommatidia of the butterfly Papilio have a fused and tiered rhabdom. The distal tier of the rhabdom is made up of four distal photoreceptors (R1–4), whereas the proximal tier is made up of four proximal (R5–8) and one basal photoreceptor cell (R9).
2.  We first confirmed by light microscopy that the ommatidia of Papilio are not twisted, i.e. have the same spatial organization all about the longitudinal axis. The polarization method, previously applied to the distal tier, hence is applicable to identify the photoreceptor location from the peak angle of the polarization sensitivity.
3.  We determined the polarization and spectral sensitivity of in total 109 proximal and basal photoreceptors in the lateral looking eye region. All of the photoreceptors were either green or red type, most of which fall into three classes as judged by the peak angles of the polarization sensitivity: around 40°, 150°, and 180° (= 0°) with respect to the dorso-ventral axis. The first two classes are formed by the proximal photoreceptors with straight microvilli oriented at the average angle of 39° (R6, 8) and 144° (R5, 7) respectively, and the third is formed by the basal photoreceptors R9 with straight microvilli oriented at 180° (= 0°). The mean polarization sensitivity (PS = maximal sensitivity/minimal sensitivity) was about 2.
4.  75% of the proximal and 48% of the basal photoreceptors were of the red type.
5.  A single ommatidium of Papilio appears to contain two to four types of spectral receptors.
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11.
In the rift valley (North-East of France/South-West of Germany), the Rhine runs freely for 300 km from South to North. The absence of natural obstacles allows the development of a very regular profile of the river. We have therefore an opportunity to study very gradual modifications of the alluvial forest communities of the fluvial corridor from upstream to downstream, according to the gradual evolution of the ecological factors, related to slope decrease and hydrological modifications.We describe, from Basel to Mainz:
1)  modification of dynamic processes in the forest communities such as successional sequences or sylvigenetic mosaïcs of the terminal stages.
2)  modification of species richness.
3)  reduction of species diversity.
4)  simplification of the forest stratification.
5)  modification of efficiency of the biogeochemical cycling.
6)  ecological vicariances.
7)  modification in species behaviour.
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12.
1.  Some properties of the open-tipped, uninsulated, pH-sensitive glass microelectrode were examined in several electrical experiments.
2.  Based on these observations, technical and theoretical problems were considered for application to the pH measurement in small cells.
3.  The intracellular pH, (pH)i, of the epithelial cell in rat duodenum measured was approximately 7.0. A reduction in (pH)i was apparent (about 0.3) with the addition of 20 mM-glucose to the bathing fluid.
4.  It was concluded, that with certain limitations such uninsulated, open-tipped microelectrodes may be successfully utilized for intracellular pH measurements.
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13.
1.  Maximal oxygen consumption rates ( [(V)\dot]\textO\text2 \dot V_{{\text{O}}_{\text{2}} } max; units, ml/g·h) were determined for four species of amphibians representing four families with habitat preferences varying from aquatic to terrestrial. Measured [(V)\dot]\textO\text2 \dot V_{{\text{O}}_{\text{2}} } max were:Xenopus laevis (aquatic), 1.33±0.16;Rana pipiens (semi-terrestrial), 0.54±0.10;Bufo cognatus (terrestrial), 1.91±0.26; andScaphiopus couchii (terrestrial), 1.91±0.26.
2.  In order to assess possible cardiovascular bases for these interspecific differences, heart rate increments (differences between resting and active heart rates) and ventricle weights were measured to evaluate differential cardiac outputs. In order to assess possible differential blood oxygen capacities, hematocrits and hemoglobin concentrations were measured. Blood volumes were determined to assess total blood oxygen storage capacities.
3.  Ventricle weights were statisticaly significantly different (p<0.01) between=" all=">B. cognatus>S. couchii>X. laevis>R. pipiens. These differences were closely positively correlated with the maximal metabolic rates of the species (Fig. 3a).
4.  There were no differences in heart rate increments between the four species (Fig. 2).
5.  Blood oxygen capacities were directly correlated with hemoglobin concentrations (Fig. 1). There were no interspecific differences in the amounts of oxygen bound per gram of hemoglobin (1.3 ml O2/g Hb). Blood oxygen capacities were significantly different in the following sequence;X. laevis >S. couchii andB. cognatus>R. pipiens.
6.  X. laevis had statistically significantly greater hematocrits than did the other three species.R. pipiens had significantly lower mean corpuscular hemoglobin concentrations.
7.  Blood volumes were statistically significantly different between all species examined,S. couchii>B. cognatus>X. laevis>R. pipiens.
8.  It is suggested that greater maximal oxygen consumption rates in anurans are correlated with 1) increased cardiac outputs based upon increased stroke volumes, 2) increased blood oxygen capacities due to either increased mean corpuscular hemoglobin concentration or increased hematocrit. Increased selective pressure for aerobic metabolism is also closely positively correlated with maximal blood oxygen storage capabilities.
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14.
1.  Gas exchange and blood gas transport has been studied in the amphibious teleost,Amphipnous cuchia. A. cuchia is a bimodal breather. Respiratory gas exchange takes place in a pair of specialized air sacs extending from the pharyngeal cavity. Aquatic and aerial gas exchange also takes place in vestigial gills, across buccopharyngeal surfaces and in the skin. All blood draining the air sacs is returned via systemic veins to the heart before systemic distribution.
2.  Oxygen uptake in fish kept in water with access to air was 33.3±8.0 ml O2STP·kg–1·h–1. About 65% of this uptake resulted from air breathing. Upon removal from water the O2 uptake rose to 44.6±15.7 ml O2· kg–1·h–1, while confinement to water breathing reduced the O2 uptake to 16.4±2.7 ml O2·kg–1·h–1. The latter value was 50% higher than aquatic O2 uptake when air breathing was available.
3.  Amphipnous practices periodic breathing and normal breathhold periods last 8–10 min. In the early phase of breathholding the gas exchange ratio (RE) was close to 0.7 but declined to low levels with breathholding. Mean RE for an average breathhold was 0.2. The low RE of the air sacs results from a high cutaneous CO2 elimination in water as well as in moist air. Estimated blood flows to the air sacs indicate flow of about 20 ml min–1 shortly after an air breath declining to 5 ml·min–1 late in a breath-hold period.
4.  Due to the shunting of air sac blood to systemic venous (jugular vein) blood, the jugular vein P\textO2 P_{{\text{O}}_2 } carried the most oxygenated blood averaging 35.2 mm Hg, the dorsal aorta 23.4 mm Hg and the hepatic vein 18.6 mm Hg.
5.  A. cuchia blood has a very high Hb concentration and O2 capacity reaching 15.5 gram % and 22 vol%, respectively. TheP 50 value was 7.9 mm Hg at pH 7.6. The Bohr factor, was –0.57, then-value 2.05 and the temperature sensitivity of the O2-Hb binding expressed by H=–13.1 Kcal·mole Hb–1. Buffering capacity was high: 34.1 mM HCO3 –·1–1.
6.  The vascular configuration inA. cuchia suggests a low efficiency of gas transport. A high blood O2 capacity and O2 affinity and a high cardiac output reduce the efficiency loss and permit the fish to suspend with air breathing for up to 30 min with a modest reduction in arterial O2 saturation from near 90% to 60%. The high blood O2 affinity allows breathholding to occur at reduced rates of systemic blood flow due to the large O2 stores available in venous blood during normal breathing.
7.  Ventral aortic blood pressure fell from about 60 mm Hg systolic value to 40 mm Hg in the dorsal aorta indicating considerable vascular resistance in the shunt connecting these vessels. The pressure gradient across the shunt remained unchanged with the breathhold cycle and is thus not part of the vasomotor activity controlling blood flow to the aerial gas exchanger.
8.  The data are discussed in relation to other air breathing fishes, notably the electric eel,Electrophorus electricus, and the African lungfish,Protopterus aethiopicus.
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15.
3DFS is a 3D flexible searching system for lead discovery. Version 1.0 of 3DFS was published recently (Wang, T.; Zhou, J. J. Chem. Inf. Comput. Sci., 1998, 38, 71–77). Here version 1.2 represents a substantial improvement over version 1.0. There are six major changes in version 1.2 compared to version 1.0.
1.  A new rule of aromatic ring recognition.
2.  The inclusion of multiple-type atoms and chains in queries.
3.  The inclusion of more spatial constraints, especially the directions of lone pairs.
4.  The improvement of the query file format.
5.  The addition of genetic search for flexible search.
6.  An output option for generating MOLfiles of hits.
Besides the above, this paper supplies:
1.  More query examples.
2.  A comparison between genetic search and Powell optimization.
3.  More detailed comparison between 3DFS and Chem-X.
4.  A preliminary application of 3DFS to K+ channel opener studies.
Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1007/s0089490050231  相似文献   

16.
1.  Rates of oxygen consumption were measured during locomotion in five species of marsupials of the family Dasyuridae. The body weights of the animals ranged between 0.15 and 1.12 kilograms.
2.  The rate of change of power input with speed was generally lower than equivalent eutherian values. The extrapolation to zero speed was consistently a higher multiple of resting metabolic levels than found in eutherians.
3.  The minimum cost of locomotion (M run) as a function of body mass (wt) is described by the equationM run=4.75 wt–0.34. The exponent is similar to that described for eutherians and reptiles, but the constant term is significantly lower.
4.  Metabolic scope in these animals is similar over the size range used and may be greater than in eutherians.
5.  Heat dissipation during locomotion has been partitioned into evaporative and non-evaporative routes. Storage of heat during locomotion was never more than fifty per cent of total production.
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17.
Phytoplanktonic populations were studied in Tazenat lake by three methods:
–  Primary production using 14C technic
–  Standing crop estimation
–  Amount of chlorophyll a
A comparison of the results obtained gives an insight into the utilisation and transformation of energy by the biota of the lake  相似文献   

18.
1.  The diffusive hydrogen conductance of chicken eggshell compound membrane was measured in situ on day 16 of incubation, in a direction parallel to the shell and the chorioallantois (lateral conductance). A value of 3.9 mmol d–1 kPa–1 was obtained through a ring 13.29 cm in circumference, 0.0076 cm thick and 0.3 cm long.
2.  Lateral hydrogen conductance for 1 mm2 of shell membrane 76 m thick is 30 times the conductance of one pore serving the same area.
3.  Lateral conductance for H2 is not significantly influenced by chorioallantoic perfusion.
4.  Oxygen consumption change due to partial covering of the hen eggshell indicates that there is a significant resistance to lateral diffusion of oxygen under the shell toward the covered area.
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19.
1.  Chronic ingestion of caffeine by male NIH strain mice alters the density of a variety of central receptors.
2.  The density of cortical A1 adenosine receptors is increased by 20%, while the density of striatal A2A adenosine receptors is unaltered.
3.  The densities of cortical 1 and cerebellar 2 adrenergic receptors are reduced byca. 25%, while the densities of cortical 1 and 2 adrenergic receptors are not significantly altered. Densities of striatal D1 and D2 dopaminergic receptors are unaltered. The densities of cortical 5 HT1 and 5 HT2 serotonergic receptors are increased by 26–30%. Densities of cortical muscarinic and nicotinic receptors are increased by 40–50%. The density of cortical benzodiazepine-binding sites associated with GABAA receptors is increased by 65%, and the affinity appears slightly decreased. The density of cortical MK-801 sites associated with NMDA-glutaminergic receptors appear unaltered.
4.  The density of cortical nitrendipine-binding sites associated with calcium channels is increased by 18%.
5.  The results indicate that chronic ingestion of caffeine equivalent to about 100 mg/kg/day in mice causes a wide range of biochemical alterations in the central nervous system.
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20.
1.  We have obtained a cDNA clone encoding a human retinal D2 dopamine receptor.
2.  The longest open reading frame (1242 bp) of this clone encodes a protein of 414 amino acids having a predicted molecular weight of 47,000 and a transmembrane topology similar to that of other G protein-coupled receptors.
3.  Transient transfection of COS-7 cells with an expression vector containing the clone resulted in expression of a protein possessing a pharmacological profile similar to that of the D2 dopamine receptor found in striatum and retina.
4.  Northern blot analysis indicated that, in rat brain and retina, the mRNA for this receptor was 2.9 kb in size.
5.  In situ hybridization was performed to examine the distribution of the mRNA for this receptor in human retina. Specific hybridization was detected in both the inner and the outer nuclear layers.
6.  These findings are consistent with prior physiological and autoradiographic studies describing the localization of D2 dopamine receptors in vertebrate retinas. Our observations suggest that photoreceptors as well as cells in the inner nuclear layer of human retinas may express the mRNA for this D2 dopamine receptor.
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