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1.
1.  We examined the retinas of 2 species of stomatopods in the superfamily Squilloidea, Cloridopsis dubia and Squilla empusa, and 2 species of the super-family Lysiosquilloidea, Coronis scolopendra and Lysiosquilla sulcata, using microspectrophotometry in the visible region of the spectrum.
2.  Retinas of all species included numerous photostable pigments, such as green reflecting pigment, hemocyanin, colored oil droplets, and vesicles. Both lysiosquilloid species also had intrarhabdomal filters within specialized photoreceptors of the midband.
3.  Squilloid species contained a single visual pigment throughout all photoreceptors, with peak absorption at medium wavelengths (near 515nm). Retinas of lysiosquilloids contained a diversity of visual pigments, with estimated max values ranging from 397 to 551 nm.
4.  Spectral sensitivity functions were estimated for the lysiosquilloid species based on estimates of visual pigment nax, photoreceptor dimensions, and specific absorbances of the visual pigments and intrarhabdomal filters. Ommatidia of midband Rows 1 to 4 contained pairs of narrowly tuned spectral receptors, appropriate for spectral discrimination, while ommatidia of midband Rows 5 and 6, and all peripheral ommatidia, had broad spectral sensitivity functions.
5.  Lysiosquilloid stomatopods have retinas that closely resemble those of gonodactyloids both structurally and in their visual pigment diversity. In contrast, squilloids have retinas that are much simpler. These differences appear to be related to the habitats and activity cycles of species belonging to the 3 major superfamilies of stomatopod crustaceans.
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2.
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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3.
1.  Interspecific diversity in the visual pigments of stomatopod crustaceans was characterized using microspectrophotometry. We examined the 10 visual pigments in main rhabdoms in retinas of 3 species of each of two genera of stomatopod crustaceans of the superfamily Gonodactyloidea, Gonodactylus (G. oerstedii, G. aloha, and G. curacaoensis) and Odontodactylus (O. scyllarus, O. brevirostris, and O. havanensis). Species were selected to provide a matched diversity of habitats.
2.  In each genus, visual pigments varied in max in several regions of the retina, as revealed by analysis of variance. The variation within closely related species of the same genus implies that visual pigments can evolve rapidly in stomatopods.
3.  In photoreceptors of the peripheral retina, which are devoted to spatial vision, visual pigment max decreased as the depth range of the various species increased, a typical pattern for marine animals. In contrast, visual pigment max in photoreceptors of retinal regions devoted to polarization vision (midband Rows 5 and 6) is not obviously correlated with the spectral environment, implying that polarization information may be confined to particular spectral ranges. Visual pigments of the tiered rows of the midband, which are committed to spectral analysis, span a larger spectral range in shallow-water than deepwater species.
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4.
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5.
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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6.
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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7.
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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8.
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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9.
1.  Spectral-sensitivity functions of large-field movement-detecting units in the lobula plate of the dronefly Eristalis tenax L., which is a Batesian mimic of the honeybee, were measured using visual stimuli consisting of light flashes, or moving gratings. Two classes of units were studied, one class responding to inward horizontal motion in the contralateral eye (presumably the homologue of the well-known HI in other fly species), and the other class responding to vertically-down-ward motion in the contralateral eye.
2.  In both classes of units, the spectral-sensitivity function of the response to flashes is characterized by two peaks, one in the UV at ca. 350 nm and the other in the blue at ca. 475 nm (Figs. 3, 8). It resembles the spectral-sensitivity function of the R1-R6 class of receptors in other flies.
3.  In both classes of units, the spectral-sensitivity function of the response to movement is characterized by a single peak, occurring in the blue at ca. 450 nm (Figs. 7, 9).
4.  Control experiments on homologous units in the Australian Sheep Blowfly Lucilia cuprina, using identical stimulating conditions reveal that the response to flashes as well as movement possesses a dual-peaked spectral sensitivity, with one peak in the UV and the other in the blue-green region of the spectrum (Figs. 10–12).
5.  The results indicate that the pathways subserving the inputs to movement-detecting neurons in Eristalis are driven by more than one spectral class of photoreceptors. They also reveal that the spectral sensitivity of movement detection in Eristalis bears a closer resemblance to that of the honeybee, than to that of other flies. This similarity to the honeybee may arise from the fact that the dronefly and the honeybee occupy similar ecological niches, both foraging for nectar in flowers.
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10.
1.  We tested the long-standing hypothesis that female frogs are attracted to the sound of a chorus of conspecific males from a distance. We studied the barking treefrog (Hyla gratiosa) because the location of choruses is unpredictable; thus, chorus sound indicates the presence of conspecific males as well as the location of a suitable breeding site.
2.  We measured the sound pressure level (SPL in dB re 20 Pa) in the 500 Hz octave band at various distances from choruses. The primary spectral peak in the advertisement call of this species is 400–500 Hz.
3.  The pattern of chorus sound attenuation in the 500 Hz band at two different sites was very similar and generally followed the pattern expected from geometrical spreading from a point source (Fig. 3). At one of the sites the SPL measured near ground level was always higher than that at a point 1 m above the ground (Fig. 3).
4.  Spectral analyses of the chorus sound at different distances showed that the low-frequency spectral peak in the range of 400–500 Hz was a prominent component, especially at 80–160 m (Figs. 1, 4). Amplitude peaks that corresponded to individual calls ofH. gratiosa and other species were also evident in oscillograms of recordings made at 160 m (Fig. 1).
5.  Gravid females oriented and moved toward a source of conspecific chorus sounds (originally recorded at 160 m from the pond) played back at 38–40 dB SPL in the 500 Hz octave band (Fig. 1, Table 1). Background noise levels were 43–47 dB SPL (C-weighted) and 24–25 dB SPL in the 500 Hz octave band.
6.  In a two-stimulus, choice experiment, females ofH. gratiosa always chose the source of a mixed chorus (H. gratiosa andH. cinerea) sound with conspecific males to a source of a pure chorus sound ofH. cinerea (Fig. 2, Table 2).
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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.
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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13.
1.  The reactions of tympanic nerve fibers ofLocusta migratoria were recorded by glass microelectrodes in the metathoracic ganglion.
2.  The units were classified by frequency-, intensity-, and directional characteristics as well as by their response pattern. The response to speciesspecific song is compared with the response to song ofEphippiger ephippiger.
3.  The physiological properties lead to a classification into three types of low-frequency neurons (characteristic frequency 3.5–4 kHz; 4kHz; 5.5–6 kHz) and one type of high-frequency neuron (12–20 kHz). This is similar to other species (Gray, 1960, Michelsen, 1971).
4.  Intensity-coding is done by sharp rising intensity characteristics and by different absolute thresholds of the units.
5.  There is a marked directional sensitivity with some differences between LF and HF units. In the low frequency range the tympanal organ seems to react as a pressure gradient receiver; for high frequencies another mechanism is discussed.
6.  No filtering of species-specific song takes place at the level of the receptor cells.
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14.
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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15.
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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16.
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   

17.
Intracellular recordings have been made of responses to step, ramp and sinusoidal changes of light by second-order L-neurones and a third-order neurone, DNI, of locust (Locusta migratoria) ocelli.
1.  The membrane potential at the peak response by an L-neurone to a change in light is proportional to the light increment or decrement, independent of background, over a range of at least 4 log units. As background increases, response latency and time-course decrease, and responses become more phasic (Fig. 1).
2.  Adaptation to a changed mean light level involves a change in sensitivity and a slow change in resting membrane potential, which never adapts completely to dark resting potential in the presence of light (Fig. 3).
3.  L-neurones can follow changes in light which last several seconds, but responses to fast changes are enhanced in amplitude (Figs. 4, 5). An increase in background light causes an increase in the frequency of sinusoidally modulated light at which the largest response occurs (Fig. 4).
4.  The responses of DNI to increased light saturate at lower intensities than those of L-neurones. During adaptation to different background light intensities, there is no change in the input-output relation of the synapse between an L-neurone and DNI (Figs. 6, 7).
5.  For a rapid decrease in light, DNI produces a rebound spike, followed by a period of silence (Figs. 5, 8).
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18.
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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19.
1.  During courtship behavior, males of the fiddler crab, Uca pugilator, drum on the ground with their large chela. The types of waves this produces and some of their properties were investigated using a laser Doppler vibrometer and accelerometers under field and laboratory conditions.
2.  Rhythmical impact onto the substratum by Uca produces 3 types of surface waves: Rayleigh waves and Love waves which contain most of the energy, and the weaker surface P-waves.
3.  The group velocity of Love-waves is 50–60 m/s in wet sand. Rayleigh waves travel at 70–80 m/s in wet sand and obout 40 m/s in dry sand. The propagation velocity of surface P-waves is 150–160 m/s in compact wet sand and about 140 m/s in wet sand perforated by crab burrows. The group velocity of Rayleigh and Love waves is not influenced by the presence of crab burrows.
4.  Fast Fourier transform (FFT) spectra of single beats reveal that the energy maxima of Rayleigh and Love waves lie in the frequency range of 340–370 Hz, i.e., at much higher frequencies than the beat rate of the fiddler crabs, which is usually below 40/s. The optimal frequency is independent of the distance from the signalling male.
5.  In the optimal frequency range, the specific damping coefficient 10 for Rayleigh waves is very low and amounts to 0.13–0.16 dB/cm in wet sand and 0.23–0.49 dB/cm in dry sand. Substrate vibrations of higher frequencies are more strongly damped.
6.  Considering the size of a fiddler crab, the physical properties of the Rayleigh and Love waves in the optimal frequency range provide a suitable signal for localizing mechanisms which rely on time or phase differences but not on intensity or spectral differences of propagating substrate vibrations.
In partial fulfillment of the requirements for the Dr. rer. nat. degree, University of Konstanz.  相似文献   

20.
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   

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