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1.
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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2.
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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3.
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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4.
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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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.
1.  Brain (hypothalamic) and cloacal temperatures were measured in heat-stressed Lesser Nighthawks (Chordeiles acutipennis), Mallards (Anas platyrhynchos), Pigeons (Columba livia), and White-Necked Ravens (Corvus cryptoleucus) and in one Roadrunner (Geococcyx californianus). Range of mean body masses was 0.047 to 1.156 kg.
2.  In all these species brain temperatures were always below cloacal temperatures (Fig. 1). The body-to-brain temperature difference was maintained nearly constant within a species over a wide range of cloacal and air temperatures, and varied in magnitude from 0.80°C in the Roadrunner to 1.29°C in Mallards.
3.  The presence of arete mirabile ophthalmicum was demonstrated in all five species. This rete may be associated with the observed pattern of brain temperature control.
4.  The body-to-brain temperature difference may be important in avoiding brain damage during core hyperthermia.
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7.
1.  Morphological correlates of circadian changes in eye sensitivity to light measured electrophysiologically were sought in the cockroach, Leucophaea maderae. Cross sections of ommatidia removed at subjective midday and subjective midnight on 3 successive days from roaches held under constant darkness (DD) at 25 ± 2 °C were examined using a transmission electron microscope for morphological differences related to sampling time.
2.  The temporal difference in submicrovillar cisternae (SMC) area appeared to exhibit a circadian rhythm, however, the amplitude of this temporal difference measured under DD was less than that observed under LD 1212 conditions. SMC areas characteristic at nighttime were achieved at subjective midnights but the area diminished only partially toward the daytime state on subjective middays.
3.  Rhabdom area remained constant and the daily rhythm of screening pigment granules (SPG) arrangement about the rhabdom was not observed under conditions of constant darkness.
4.  Results of this study indicate that a pacemaker(s) actively influences the change in the SMC toward the nighttime state, whereas, the change toward the daytime state results from a passive mechanism that possibly could be accelerated by light.
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8.
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   

9.
1.  Some units in the lateral ocellar nerves of the locust,Locusta migratoria, are influenced transsynaptically by the activity of ascending fibres in the thoracic connectives and therefore may be efferent to the afferent ocellar system.
2.  A variety of sensory inputs excite the ocellar nerve units, including illumination of the compound eyes, active and passive movement of the wings, wind stimuli to the thorax and sound.
3.  Most ocellar interneurons are influenced transsynaptically by electrical stimulation of the cervical connectives. L-neurons are depolarized and the components of their response to a rectangular light pulse are changed in amplitude. Only a few S-neurons could be examined. All of them were excited directly or indirectly.
4.  The descending ocellar interneurons (DN's) are influenced by stimulation of the contralateral connective, perhaps via efference to the ocellus or to ocellar L-cells.
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10.
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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11.
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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12.
1.  There are two types of cold receptors on the antennae of Periplaneta americana. One type of cold receptor is present in a thermo- and hygroreceptive sensillum along with a moist receptor and a dry receptor, and the other is in a thermoreceptive and olfactory sensillum along with olfactory receptors. These two types of cold receptors were investigated using stimulations of constant temperature (T), stepwise decrease of temperature (T), and constant rates of temperature decrease (dT/dt).
2.  For cold receptors in the thermo- and hygroreceptive sensilla (C-H cells), steady-state activities are higher at lower constant temperatures (T) within the range of 16–31 °C examined (n = 7). On the other hand, those of the cold receptors in the thermoreceptive and olfactory sensilla (C-O cells) have individually a broad activity maximum in the range of 18–27 °C (n = 7).
3.  The differential sensitivity to downward temperature steps (T) of C-H cells was in the range of - 5.4 to - 12.4 (impulses/s)/°C (n = 11). It was higher at lower adapting temperature, from which changes were initiated, in the range of about 21 to 31 °C, that is, it was reflected by the steady-state activity at the initial and adapting temperature. On the other hand, the differential sensitivity of C-O cells was in the range of - 10.7 to- 15.2 (impulses/s)/°C (n = 9), and was little reflected by the steady-state activity.
4.  Responses to decreasing temperature in C-H cells (n = 14) are negatively related to the rate of temperature decrease (dT/dt) in the range of about 0 to - 0.16 °C/s at given temperatures, and are also affected by instantaneous temperature (T) in the range of 18 to 30 °C. This dependence is also observed in C-O cells (n = 10), but less pronounced than in C-H cells.
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13.
1.  Filiform hairs of various lengths on the cerci of adult crickets vibrate in a sound field. These movements were measured with a photodetector for sound frequencies from 10 Hz to 200 Hz in the species Acheta domestica, Gryllus bimaculatus and Phaeophilacris spectrum.
2.  With low air-particle velocities, the hair shafts were deflected sinusoidally from their resting position, without bending or secondary oscillations (Figs. 2 A, 3 A). At higher velocities (from ca. 80 mm/s peak velocity, depending on the properties of the individual hairs), the shaft struck the cuticular rim of the socket in which the base of the hair is seated (Fig. 2B). This contact was made at an average angular displacement from the resting position of 5.16°±1.0°.
3.  The best frequencies of the hairs were found to be between 40 Hz and 100 Hz (Fig. 5A). The slope of the amplitude curve for constant peak air-particle velocity at frequencies below the best frequencies was between 0 and 6 dB/octave. Long hairs had smaller slope values than short hairs (Fig. 5C).
4.  At its best frequency the ratio of maximal tip displacement of a hair to the displacement of the air particles in the sound field was between 0.2 and 2. Only a small number of hairs (2 out of 36) showed tip displacements exceeding twice the air-particle displacement. The values of maximal angular displacement were not correlated to hair length (Fig. 5 B).
5.  The angular displacement of the hairs was phase shifted with respect to the air-particle velocity by 0° to +45° (phase lead) at sound frequencies around 10 Hz and by -45° to -120° (phase lag) at 200 Hz (Figs. 3C, 4B). At a particular frequency long hairs tended to have larger phase lags than shorter hairs (Fig. 5D).
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14.
Müller  D. G.  Frenzer  K. 《Hydrobiologia》1993,(1):37-44
Culture studies with healthy and virus-infected isolates of Ectocarpus siliculosus, Feldmannia simplex and F. irregularis gave the following results:
–  Virus particles are produced in deformed reproductive organs (sporangia or gametangia) of the hosts and are released into the surrounding seawater.
–  Their infective potential is lost after several days of storage under laboratory conditions.
–  New infections occur when gametes or spores of the host get in contact with virus particles. The virus genome enters all cells of the developing new plant via mitosis.
–  Virus expression is variable, and in many cases the viability of the host is not impaired. Infected host plants may be partly fertile and pass the infection to their daughter plants.
–  Meiosis of the host can eliminate the virus genome and generate healthy progeny.
–  The genome of the Ectocarpus virus consists of dsDNA. Meiotic segregation patterns suggest an intimate association between virus genome and host chromosomes.
–  An extra-generic host range has been demonstrated for the Ectocarpus virus.
–  Field observations suggest that virus infections in ectocarpalean algae occur on all coasts of the world, and many or all Ectocarpus and Feldmannia populations are subject to contact with virus genomes.
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15.
The rich deciduous woodland at Loi, Luster, Inner Sogn, 61° 20 N., was traditionally used for fodder production from both tree and field layer. After more than nearly 40 years of disuse and secondary forest succession, experimental efforts were made to restore the traditional agricultural meadow woodland. Following a detailed preliminary registration of the vegetation the following measures were taken:
1.  The understory tree layer, mainly Alnus incana was removed.
2.  The old Ulmus glabra pollards were pruned back to traditional shape, as were some tall shurbs of Corylus avellana.
3.  The field layer was mown once or twice yearly.
The main results are:
1.  The pollarded elms have developed bundles of new twigs at the pruning points and are in good condition.
2.  After an expansion of tall, nitrophilic herbs, e.g. Urtica dioica, Impatiens noli-tangere and Rubus idaeus, low and medium sized herbs and grasses have increased both in numbers, frequency and abundance. Helio- and thermophilic forest margin species are also more prominent. The moss layer has also become more dense and varied.
3.  The average number of species in permanent plots has nearly doubled.
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16.
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   

17.
1.  The dependence of dark-adapted fly (Calliphora vicina) photoreceptors on oxygen was investigated by measuring the electroretinogram (ERG), the receptor potential, and the redox states of the mitochondrial cytochromes. The redox states were determined via reflection microspectrophotometry on white-eyed fly mutants.
2.  The light sensitivity of the photoreceptors at oxygen fractions above 2% is identical to that in the normal (air) environment, as judged from both ERG and receptor potential. Light sensitivity is rather abruptly and strongly reduced at oxygen fractions lower than 1% and vanishes at anoxia (0%).
3.  The redox state of the mitochondrial cytochromes also changes around oxygen fractions of 1–2%, but the dependence on oxygen fraction is less abrupt than that of ERG and receptor potential.
4.  The mitochondrial activity of dark-adapted fly photoreceptors appears to be well-buffered, to warrant ample supply of metabolic energy for unimpaired photoreceptor function down to extremely low oxygen levels.
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18.
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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19.
The coupling mechanism between the bilaterally paired optic lobe circadian pacemakers in the cricket Gryllus bimaculatus was investigated by recording locomotor activity, under constant light or constant red light, after the optic nerve was unilaterally severed.
1.  The majority (about 70%) of the animals showed a locomotor rhythm with 2 rhythmic components; one freerunning with a period of 25.33 ± 0.41 (SD) h and the other with 24.36 ± 0.37 (SD) h under constant light (Fig. 3A).
2.  Removal of the intact side optic lobe abolished the longer period component (Fig. 4A), while the operation on the operated side caused a reverse effect (Fig. 4B), indicating that the longer and the shorter period components are driven by the pacemaker on the intact and the operated side, respectively.
3.  The activity driven by a pacemaker was inhibited during the subjective day of the contralateral pacemaker (circadian time 0–10, Fig. 5).
4.  The freerunning periods of the two components were not constant but varied as a function of the mutual phase angle relationship (Figs. 3A, 7, 8).
These results suggest that the 2 optic lobe pacemakers weakly couple to one another and that the cricket maintains a stable temporal structure in its behavior through the phase-dependent mututal inhibition of activity and the phase-dependent freerunning period modulation.  相似文献   

20.
The caudal photoreceptors (CPRs) of crayfish (Procambarus clarkii) can trigger walking and abdominal movements by their response to light.
1.  In a restrained, inverted crayfish, illumination of A6 evoked a CPR discharge followed by leg movements and bursting from the abdominal tonic flexor (TF) motoneurons. Intracellular electrical stimulation of a single CPR at high frequency (80 Hz) evoked similar responses.
2.  Responses only occurred when a single CPR axon was driven at 60 Hz or more and outlasted the stimulus.
3.  CPR stimulation also excites the pattern-initiating network (Moore and Larimer 1987) in the abdomen.
4.  The axon of the CPR projects from ganglion A6 to the brain. Terminal branches occur in the subesophageal ganglion and the brain. A small descending interneuron is dye-coupled to CPR in the subesophageal ganglion.
5.  In animals with cut circumesophageal connectives, the CPRs can evoke walking and the abdominal motor pattern.
6.  The relationship of the abdominal motor pattern to walking is altered by restraint and/or inversion. In freely moving crayfish, the cyclic abdominal motor pattern is only observed with backward walking. In restrained, inverted crayfish, the motor pattern occurs with both forward or backward walking.
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