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1.
In response female pheromone the male gypsy moth flies a zigzagging path upwind to locate the source of odor. He determines wind direction visually. To learn more about the mechanism underlying this behavior, we studied descending interneurons with dye-filled micro-electrodes. We studied the interneuronal responses to combinations of pheromone and visual stimuli.
1.  We recorded 5 neurons whose directionally selective visual responses to wide field pattern movement were amplified by pheromone (Figs. 2–6).
2.  The activity of the above neurons was more closely correlated with the position of the moving pattern than with its velocity (Fig. 4).
3.  One neuron showed no clearly directional visual response and no response to pheromone. Yet in the presence of pheromone it showed directionally selective visual responses (Fig. 6).
4.  We recorded 4 neurons whose directionally selective visual responses were not modulated by pheromone (Fig. 7), ruling out the possibility that the effect of the pheromone was simply to raise the activity of all visual neurons.
5.  Our results suggest that female pheromone amplifies some neural pathways mediating male optomotor responses, especially the directionally selective responses to the transverse movement of the image, both below and above the animal.
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2.
Temporal coding in the moth ear was inferred from the response of the auditory receptor to acoustic stimuli with different temporal characteristics.
1.  Determinations of the threshold with different stimulus pulse durations showed that the moth ear behaves as an energy detector with a maximum time constant (the integration time) of 25 ms. Pulse durations beyond this value did not result in decreased thresholds (Fig. 1).
2.  The synchronization to amplitude modulations was determined by stimulating the moth ear with amplitude modulated (AM) tones (carrier frequency: 40 kHz) and AM white noise presented as 450 ms pulses separated by pauses of similar length. The modulation depth was constant (100%) whereas the modulation frequency,f m, was varied. The maximumf m which the auditory receptors could follow was 200 Hz (P<0.05) (figs.=" 2,=" 3,=" 4).=">
3.  The relatively broad tuning of the only receptor which was functional at the relevant stimulus intensities suggested that AM detection could only be based on temporal cues. This was confirmed by the results showing the same degree of synchronization independent of carrier.
4.  A minimum time constant for the receptor was also determined by interrupting a 400 ms noise pulse by a gap (Figs. 5, 6). The threshold for gap detection of the moth ear was ca. 2 ms on a 2.5% significance level (one sided test).
5.  The temporal acuity reported here seems to be fine enough to explain the temporal resolution suggested by behavioral results from other insect species. The results are discussed in relation to acoustic communication in insects as well as in relation to temporal resolution in vertebrates.
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3.
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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4.
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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5.
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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6.
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   

7.
1.  Coordinated movements of the wings during flight in the locust result from coordinated activity of flight neurons in the thoracic ganglia. Many flight interneurons and motoneurons fire synchronous bursts of action potentials during the expression of the flight motor pattern. The mechanisms which underlie this synchronous firing were investigated in a deafferented preparation of Locusta migratoria.
2.  Simultaneous intracellular recordings were taken from flight neurons in the mesothoracic ganglion using glass microelectrodes filled with fluorescent dye.
3.  Three levels of synchronous activity between synergistic motoneurons and between the right and left partners of bilaterally symmetrical pairs of interneurons were observed: bursting which was loosely in phase but which showed little correlation between the temporal parameters of individual bursts in the two neurons; bursting which showed synchrony of the beginning and end of bursts; and bursts which showed highly synchronous spike-for-spike activity.
4.  Direct interactions between the neurons had little or no part to play in maintaining any of the levels of synchrony, even in instances of very close synchrony (spikes in different neurons occurring within 1 ms of each other). Highly synchronous firing was a consequence of common synaptic input impinging on neurons with similar morphological and physiological properties.
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8.
J. Robb 《Human Evolution》1994,9(3):215-229
In recent years anthropologists have made much progress in understanding ancient activities from skeletal remains. In this paper, material from the Iron Age cemetery at Pontecagnano (VII-IV century BC) is used to illustrate activity-related traits of eight basic categories:
(1)  idiosyncratic patterns of dental wear
(2)  activity-related articular degeneration
(3)  non-pathological functional alterations (neoformations, contact facets)
(4)  mechanical remodelling of bone architecture
(5)  enthesopathies (muscular lesions)
(6)  traumatic lesions
(7)  activity-related pathologies
(8)  activity-related nutritional characteristics
These traits, and others, can be used not only singly but in conjunction to define (a) patterns of activity and occupational specialization for individuals, and (b) distributions within society reflecting the basic division of labor by geneder and class.  相似文献   

9.
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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10.
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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11.
1.  Small passerine migrants achieve endurance flight while fasting, together with one of the highest mass-specific energy rates. Metabolic responses to flight and fasting were examined in three species of free-living migrants (Sylvia borin, Ficedula hypoleuca, Erithacus rubecula) by measuring plasma concentrations of glucose, uric acid, triglycerides, glycerol, free fatty acids (FFA), and -hydroxybutyrate (-OHB) in three main physiological situations (feeding, overnight fasting, nocturnal flight) and while changing between these situations.
2.  Overnight-fasted birds showed low triglyceride and uric acid levels. Contrary to mammals, FFA and glycerol levels were not increased in agreement with published data on birds. The transition from feeding to fasting (post-feeding) was distinguished by a temporary rise in FFA and a drop in glucose levels.
3.  Birds utilize fat during migratory flight, indicated by high levels of FFA, glycerol, and -OHB. For the first time, high triglyceride levels were found in an exercising vertebrate. The use of protein during flight was demonstrated by high uric acid levels.
4.  Birds kept inactive after flight showed a more pronounced reduction of the fat and protein utilization and post-exercise ketosis than naturally landed birds.
5.  Differences among the three species in the metabolic pattern suggest that the garden warbler shows the greatest metabolic adaption to endurance flight, having the highest levels of fat metabolites and the highest body fat reserves.
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12.
1.  The larva of the tiger beetle (Cicindela chinensis) possesses six stemmata on either side of the head. Optical and physiological properties of two pairs of large stemmata and a pair of anterior medium sized stemmata, and responses of second-order visual interneurons (medulla neurons) have been examined.
2.  Objects at infinite distance were estimated to focus 50 m deep in the retina in the large stemmata. Receptive fields of four large stemmata, the acceptance angle of each being 90°, largely overlapped one another.
3.  The stemmata possessed a single type of retinular cell with a maximal spectral sensitivity at 525 nm, and a flicker fusion frequency of 25–50 Hz.
4.  Medulla neurons expanded fan-shaped dendrites in the medulla neuropil, and their axons extended into the protocerebrum. They responded to illumination with a variety of discharge patterns. They also responded with spike discharges to moving objects and to apparent movements provided by sequential illumination or extinction of LEDs. They did not show directional selectivity. They possessed well-defined receptive fields ranging from 30° to 105°.
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13.
Flight metabolism of locusts has been extensively studied, but biochemical and physiological methods have led to conflicting results. For this reason the non-invasive and non-destructive method of 31P NMR spectroscopy was used to study migratory locusts, Locusta migratoria, at rest and during flight.
1.  In the flight muscle of resting locusts the ratio of phosphoarginine to ATP was the same whether determined by NMR (1.76) or biochemically, but the NMR-visible content of inorganic phosphate (Pi) was only 40% of ATP, i.e., much lower than total Pi as determined biochemically. This suggests that most of the Pi in flight muscle is not free, and hence not available as substrate or effector for cytosolic enzymes. Similarly, the free content of ADP and AMP in resting muscle was calculated to be much lower than the total content.
2.  Flight brought about a marked increase in Pi and a decrease in phosphoarginine in flight muscle although there was no change in intracellular pH.
3.  At the initiation of flight a new steady state of ATP, Pi, and phosphoarginine was rapidly established and minimal changes occurred after the first 2 s of flight.
4.  From the free contents of ATP and phosphoarginine in working flight muscle the flight-induced fractional increases in free ADP and free AMP were calculated to be 5.0-fold and 27.4-fold, respectively. As Pi, ADP, and AMP are substrates and potent effectors of enzymes, the flight-induced increase in their contents is likely to have marked effects on metabolic flux in working muscle.
5.  After short-term flight as well as prolonged flight, phosphoarginine, ATP, and Pi returned rapidly to their preflight levels, indicating that metabolic recovery from flight is rapid.
6.  The locust appears to be an appropriate model for the study of metabolic regulation in aerobic muscle during exercise.
Dedicated to Professor Dr. Ernst Zebe (University of Münster) on occasion of his 65th birthday.  相似文献   

14.
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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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.
Conclusions  
(1)  The aminoesters inhibit glucose-stimulated proton extrusion by yeast cells.
(2)  The inhibitory activity depends on aliphatic carbon chain length.
(3)  The inhibition of proton extrusion is concentration-dependent.
(4)  The aminoesters stimulate quinacrine accumulation in vacuoles of yeast cells so they should possess affinities for lysosomes.
This work was supported byKBN grant no. 7 A203 013 07.  相似文献   

17.
The function of the flapping elytra was investigated in garden shafers (Melolontha melolontha L.) and rhinoceros beetles (Oryctes boas Fabr.).
1.  The movements of alae and elytra are determined. Both move with the same frequency and in the same phase, but the range of the elytral stroke never reaches below the frontal plane. In downstroke the elytra are at an angle positive to the airstream (horizontal flight).
2.  After exact investigation of the construction of the elytra (depth, width, length, surface, torsion and velocity of each point of the elytra) the most effective point in the production of lift during the downstroke was determined.
3.  After loss of one third of the surface of the elytra the beetles cannot fly horizontally. In tethered flight the wing stroke frequency of the alae does not increase when the elytra are shortened. Shortening of the elytra does not interfere with the resonance system of the pterothorax.
4.  The lift of the elytra results from active and passive components (more than 17% of the body weight). In the airstream (front 2.00 m/s, average body weight 944 mp) the passive lift is 14.3% for elytra in the down position; 3.1% of the lift is caused by the active downstroke.
5.  The elytra of these beetles are indispensible for horizontal flight. Primarily they produce lift passively with added help from the downstroke, and have no function for the drag. The effect of upstroke is discussed.
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18.
Oncostatin M, a multifunctional cytokine   总被引：6，自引：0，他引：6  
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19.
Locusts (Locusta migratoria) were flown in a flight simulator which converts yaw torque into angular motion of the visual environment (Fig. 1). The modalities and the time-course of steering behavior under these closed-loop conditions have been investigated.
1.  Locusts flying under visual closed-loop conditions stabilize their visual environment by performing correctional steering manoeuvres. Besides torque production, due to differential wing movements and ruddering, correctional steering also involves head movements (Fig. 6).
2.  During open-loop steering, ruddering and yaw torque begin some 60 ms after the onset of the visually simulated deviation from course. Head movements occur some 90 ms after stimulus onset, i.e. some 30 ms later than yaw torque (Figs. 3, 5) and therefore do not initiate thoracic steering outputs.
3.  Open- and closed-loop correctional steering do not differ in their behavioral components or temporal organization (Figs. 2, 6, Table 1).
4.  In the absence of major disturbances, correctional steering under closed-loop conditions is performed with minimal ruddering (only a few degrees in amplitude), that probably produces little or no aerodynamic drag (Fig. 6).
5.  Locusts prevented from moving their heads still stabilize their visual environment in the closed-loop situation. However, the precision of steering is affected by this constraint (Figs. 8, 9, 10, 12). Head immobilization also alters the temporal coordination of correctional steering (Figs. 7, 11).
6.  These results show that head movements, in addition to their generally accepted role in vision improvement, also contribute to the precision and temporal coordination of correctional flight manoeuvres. The mechanism is partly via proprioceptive feedback.
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20.
1.  The head-bobbing rhythm previously reported in pigeons Columba livia during approximately level landing flights also occurs in upwards landing flights. This finding strengthens the evidence that head-bobbing in flight is linked specifically to approach to a landing target, and that the behaviour has a visual function.
2.  In both level and upwards flights, head-bobbing arises from an oscillating flexion and extension of the neck. Rhythms in translation and rotation of the body do not make a detectable contribution to head-bobbing.
3.  Head-bobbing occurs at the same frequency as the wingbeat cycle and in a fixed phase relationship to it.
4.  The orientation of the head relative to the horizontal is correlated with the trajectory of upwards approach to a perch. In contrast to downwards landing flights, this relationship cannot have the function of keeping the perch in focus during landing. It is proposed instead that it enables the head to be bobbed along the axis which maximizes amplification of optic flow.
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