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1.
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2.
1.  The light-dependent demolition of rhabdoms induced by a protein phosphatase inhibitor, okadaic acid (OKA) in retinas of a crab (Leptograpsus variegatus) is examined to determine whether the effects of OKA merely amplify the endocytosis of normal phototransductive membrane turnover, or are distinct from it.
2.  OKA-induced demolition by dawn retinas maintained in vitro is partially blocked by either of two protein kinase C inhibitors, staurosporine and H-7. It is similarly blocked by a Ca2+-channel blocking agent, diltiazem.
3.  Large night rhabdoms illuminated at 40 lux for up to 20 min are reduced by pinocytosis which is not inhibited by either staurosporine or diltiazem, each in the absence of OKA.
4.  Pinocytosis is not blocked by a high concentration of a specific tyrosine kinase inhibitor, genistein in absence of OKA.
5.  It is inferred that (i) phosphorylations of rhabdomeral proteins drive light-dependent, OKA-induced endocytosis; (ii) phosphorylations (including that of rhodopsin) do not drive normal, light-dependent endocytosis; (iii) tyrosine phosphorylations of a notional, minor population of rhabdomeral proteins are unlikely to determine, normal, light-dependent endocytosis of phototransductive membrane; (iv) entry of Ca2+ into R1-7 photoreceptors via either light-dependent or other channels is necessary for events provoked by OKA, but irrelevant to normal light-dependent endocytosis.
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3.
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4.
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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5.
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   

6.
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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7.
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   

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.
1.  The cochlea of the horseshoe bat,Rhinolophus ferrumequinum, was frequency mapped by exposing for 30 min to one or two continuous pure tones of intensities between 70 and 110 dB SPL. The evaluation was made by differentiating between normal and swollen nuclei of the outer hair cells (OHC) of the organ of Corti and by measuring the diameter of the nuclei of the OHC.
2.  In control animals the radial diameter of the OHC nuclei varies systematically from a mean of 2.85 m at the base to 3.2 um at the apex (Fig. 1).
3.  All frequencies used for exposure were normalized to the resting frequency (FR), which is the frequency of the pure tone component of the orientation sound in a non-flying bat. The individual FR lay between 82.6 and 83.3 kHz.
4.  For analysing the small frequencies between 83.0 to 86.0 kHz in which relevant echoes occur, 3.15 mm length of the basilar membrane is used, about the same length as for the octaves from FR/4 to FR/2 (2.85 mm) and from FR/2 to FR (3.2 mm) (Fig. Ca, b).
5.  The discontinuity of the mechanical data at 4.5 mm of the length of the basilar membrane (part I of this paper) coincides with FR and the less pronounced discontinuity at 7.8 mm coincides with FR/2.
6.  Location and mechanism of the auditory filter are discussed.
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10.
Oncostatin M, a multifunctional cytokine   总被引：6，自引：0，他引：6  
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11.
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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12.
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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13.
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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14.
1.  Seasonal changes in the half-times (0.5) for calcium influx and outflux in bone, skin and scales, and soft-tissue compartments ofF. kansae were measured.
2.  The size of diffusible calcium pools in the three compartments was estimated from the ratio of the loading and unloading half-times. Both the bone and skin and scales compartments contain diffusible calcium pools which increase in size during the summer months.
3.  The calcium in the soft-tissue compartment is all diffusible, and the kinetics indicate that this compartment receives calcium from the other two compartments.
4.  Hypophysectomy reduced the rate of calcium turnover in summer animals to the levels measured in intact winter animals. Such treatment also affected the distribution of radiocalcium within the animal.
5.  It is concluded that acellular bone is a metabolically active tissue.
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15.
In a task designed to simulate olfactory-guided foraging, the ability of squirrel monkeys to discriminate an artificial 12-component odorant from 3-, 6-, 9- or 11- component submixtures was investigated. A combination of factors was found to contribute to the animals' performance:
1.  Discriminability generally decreased as the number of components in the submixture increased.
2  Submixtures did not contribute equally to mixture perception, and one component in particular (cineole) disproportionately influenced stimulus discriminability.
3.  Interactive effects between submixtures resulted in marked deviations from the general pattern of discriminability.
4.  Changes in the relative concentration of submixtures could also influence discriminability.
5.  Finally, individual differences in responsiveness to particular stimuli were apparent.
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16.
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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17.
1.  The effects of chronic deafferentation, 3–180 days, are tested on the function and morphology of the crab (Carcinus maenas) ventilatory central pattern generator (CPGv). Almost all afferent axons are carried in the mixed sensory/motor levator nerve. The ability to speed the CPGv cycle rate by stimulating this nerve (Wilkens and DiCaprio 1994) decreases as the afferent neurons degenerate. Stimulation of the levator nerve eliminates motor units from the output even after 60 days of deafferentation, similar to the effects seen in acute preparations.
2.  The 3 oval organ afferent axons of the levator nerve have central somata and survive scaphognathectomy. Impulses carried by these axons are known to inhibit the CPGv in acutely deafferented preparations and they are believed to be responsible for the persistent inhibition following small afferent degeneration seen here.
3.  After 6 months of deafferentation the motor neuron collateral arborization densities within the thoracic ganglia are reduced, but all motor neurons appear to survive. These long-term deafferented CPGvs generate accurate motor patterns at similar rates to the control CPGv, but at reduced intraburst spike frequency. The crab CPGv is quite stable following chronic deafferentation.
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18.
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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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.
We have identified a nerve carrying auditory afferents and characterized their physiological responses in the tiger beetle,Cicindela marutha.
1.  The tympana are located at the lateral margins of the first abdominal tergum. The nerve carrying the tympanal afferents is a branch of the dorsal root from the first abdominal ganglion.
2.  Both male and female auditory afferent responses are sharply tuned to 30 kHz with sensitivities of 50–55 dB SPL.
3.  The auditory afferents show little adaptation and accurately code the temporal characteristics of the stimulus with the limit of a resolution of 6–10 ms.
4.  The difference in threshold between contralateral and ipsilateral afferents for lateral stimuli is greatest at 30 kHz and is at least 10–15 dB.
5.  Ablation studies indicate that the floppy membrane in the anterolateral corner of the tympanum is crucial for transduction while the medial portion of the tympanum is less important.
6.  The tiger beetle and acridid (locust and grasshopper) ears have evolved independently from homologous peripheral structures. The neural precursor of the tympanal organs in both animals is likely the pleural chordotonal organ of the first abdominal segment.
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