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1.
以两种陶粒作为生物过滤床的填料净化含乙苯废气。主要考察温度变化对生物过滤塔净化含乙苯废气效果的影响。在稳态条件下,在温度为15~25℃时,乙苯的去除效率随运行温度的升高而升高,在25~45℃时,乙苯的去除效率随温度升高而降低。并通过实验得出了温度系数。结果表明,对于零级反应,温度对高入口体积负荷的影响较低入口体积负荷的影响大,而对于一级反应,则出现了相反的结果。同时也表明不同填料对温度系数的影响不显著。  相似文献   

2.
A multiterminal neurone, recently identified at the wing-hinge of the atympanate moth Manduca sexta, is shown to respond as a proprioceptor monitoring elevatory movements of the hind wing. Extracellular recordings from the individual receptor axon confirm this cell to be the source of the spontaneous and regular discharge observed in previous recordings of peripheral nerve 3N1b1. When the wing is raised, this tonic discharge rate increases proportionally with the angle of elevation. When the wing is displaced sinusoidally at a low frequency, the receptor discharge is modulated throughout the wing beat, increasing steadily to a maximum at the top of the upstroke, then slowly decreasing to a minimum at the bottom of the downstroke. At higher wing-beat frequencies, a phasic burst of activity occurs near the top of the upstroke, followed by a silent period during the down-stroke. Video-microscopic observations of the wing-hinge during active, stationary flight suggest that the receptor is stimulated by the stretching of its peripheral attachment, the subalar membrane. Stretch receptor sensitivity to wing movement is demonstrated in representatives of 4 lepidopteran families, suggesting that the proprioceptive response is widespread among the Lepidoptera. The functional role of the wing-hinge receptor, and its proposed homologous relationship to both the B cell of the noctuoid moth ear, and the locust wing-hinge stretch receptor are discussed.Abbreviations CO chordotonal organ - EGAA Enhanced Graphics Acquisition and Analysis System - HP hair plate - 3N1b1 tympanal nerve - SR stretch receptor  相似文献   

3.
Reproductive physiology of male moths is regulated by a peripheral circadian system, which controls the timing of sperm release from the testis into the upper vas deferens (UVD) and timing of sperm transfer from the UVD to the seminal vesicles. We investigated various effects of light and temperature on sperm release and transfer rhythms in the moth Spodoptera littoralis. We report that both rhythms persist for up to 1 week in constant darkness without significant dampening and are also temperature compensated in the range from 20°C to 30°C. However, the duration of sperm retention in the UVD is temperature-dependent; consequently, temperature exerts a masking effect on the rhythm of sperm transfer. Experimental manipulations of light and temperature regime demonstrated that light dominates over temperature in entraining the timing of sperm release and transfer. Nevertheless, temperature plays a critical role in the absence of light Zeitgeber. Sperm release and transfer are arrhythmic in constant light (LL); however, both rhythms are restored by temperature cycles.  相似文献   

4.
Butterflies and moths develop highly ordered coloration in their wing for signal transmission. We have investigated the ultrastructural arrangement of wing coloration of a moth Asota caricae, applying light, optical polarized, and scanning electron microscopy, and spectrophotometry. The forewing of the moth is brown in color with a white spot at the center. The hindwing is golden yellow in color with many black patches in it. The ventral part of the forewing and dorsal hindwing share the similar color pattern. The ventral part of the hindwing has dull coloration in comparison to the dorsal one although the pattern remains same. The spectrometry analysis reveals various patterns of absorbance and reflectance spectra for various colors. The peak observed for various colors remain same although the intensity of peak changes. Bright colors possess highly ordered structures whereas irregular structures are found in dull colored scales. The color variation observed due to dorsal and ventral part of the wing is due to the minute difference observed in terms of ultrastructural arrangement revealed by scanning electron microscope. The color pattern of A. caricae is due to variation of microstructures present within the scale.  相似文献   

5.
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.
  相似文献   

6.
Summary Choriogenesis in silkmoths (superfamily Bombycoidea) and in a sphingid moth (super-family Sphingoidea) differ in major, but discrete, ways. In silkmoths, the predominant lamellar component assembles early in choriogenesis to form a thin framework. Subsequently, the lamellar framework is modified, first by expansion, and then by densification. Finally, ornate surface structures called aeropyle crowns form in some silkmoths, but they are absent in the species described here. In the sphingid, lamellar framework formation occurs throughout choriogenesis rather than largely during the early stages as in silkmoths. Lamellar densification occurs, but lamellar expansion and aeropyle crown formation do not. An evolutionary model is presented that accounts for the observed morphogenetic differences. Patterns of chorion protein synthesis in the sphingid differ from those in silkmoths in ways that are interpretable in light of the observed morphogenetic differences and the previously postulated functions of the proteins in silkmoths.  相似文献   

7.

1. 1.|The purpose of this study was to determine whether chronic latency changes were induced in the auditory nerve-brainstem potentials (ABR) during long-term heat exposure (acclimation).

2. 2.|Latency prolongations of the ABR were observed during acute (5 days) heat exposure. This was followed by a shortening of latencies and amplitude elevation after long-term (2 months) heat exposure (acclimation).

3. 3.|It was concluded that long-term exposure to heat induces chronic changes in nervous activity.

Author Keywords: Auditory nerve; brainstem; evoked potentials; heat exposure; acclimation; rats  相似文献   


8.
Gao WJ  Leung KT  Qin WS  Liao BQ 《Bioresource technology》2011,102(19):8733-8740
Effects of temperature and temperature shock on the performance and microbial community structure of a submerged anaerobic membrane bioreactor (SAnMBR) treating thermomechanical pulping pressate were studied for 416 days. The results showed that the SAnMBR system were highly resilient to temperature variations in terms of chemical oxygen demand (COD) removal. The residual COD in treated effluent was slightly higher at 55 °C than that at 37 and 45 °C. There were no significant changes in biogas production rate and biogas composition. However, temperature shocks resulted in an increase in biogas production temporarily. The SAnMBR could tolerate the 5 and 10 °C temperature shocks at 37 °C and the temperature variations from 37 to 45 °C. The temperature shock of 5 and 10 °C at 45 °C led to slight and significant disturbance of the performance, respectively. Temperature affected the richness and diversity of microbial populations.  相似文献   

9.
The effects of low temperature assay (5 °C) on the properties of the aerobic (low phosphate) vs. anoxic (high phosphate) forms of pyruvate kinase (PK) from foot muscle and gill of the whelk Busycon canaliculatum (L.) were assessed at two pH values, pH 7.00 and 7.25, and compared to control conditions of 20 °C and pH 7.00 (all assayed in imidazole buffer). When pH was held constant at 7.00, the decrease in assay temperature to 5 °C had large effects on the measured kinetic parameters of all PK forms, as compared to 20 °C and pH 7.00. However, when assay pH was allowed to rise, from 7.00 to 7.25, with the temperature decrease to 5 °C there were fewer alterations of kinetic parameters and quantitatively smaller changes to enzyme properties. It appears, then, that when pH rises with decreasing temperature following alphastat predictions, kinetic properties of PK are largely conserved. Low temperature, at either pH value, had several significant effects on PK properties. For example, low temperature raised the S0.5 for phosphoenolpyruvate of PK-anoxic from gill by 3–6 fold and decreased the I50 Mg · ATP for PK-anoxic from foot by the same amount. Arrhenius plots of PK activity for the gill PK forms showed a distinct break at 10 °C; > 10 °C Q10 was 2.5 whereas < 10 °C Q10 was 8.4. Temperature-dependent changes in all cases affected enzyme properties in a manner that would restrict enzyme function at low temperature.  相似文献   

10.
The male silkworm moth, Bombyx mori, exhibits a zigzagging pattern as it walks upwind to pheromones. This species usually does not fly, but obvious wing-beating accompanies the pheromone-mediated walking. Males supported by a `sled', after having their legs removed, also moved upwind in a pheromone plume along zigzagging tracks, indicating that wing-generated thrust and torque result in locomotory paths similar to those observed from walking moths. Using a high-speed video system we investigated the correlation between the wing movements and zigzag walking. The wing ipsilateral to the direction of the turn showed a greater degree of retraction with respect to the contralateral wing. The timing of the wing retraction pattern was synchronized with changes of direction in the walking track. Coordination of wing movements and walking pattern was not dependent on visual feedback or sensory feedback generated from neck movements associated with turning. The results presented here, taken together with our previous studies of descending interneurons suggest that the coordination of wing movements with the walking pattern may result from the activity of a set of identified interneurons descending from the brain to the thoracic ganglia and/or may be coordinated by coupling of oscillating circuits for walking and wing beating. Accepted: 15 May 1997  相似文献   

11.
ABSTRACT. The dogbane tiger moth ( Cycnia tenera Hübner; Arctiidae) responds to ultrasonic, artificial bat echolocation signals by emitting stereotyped trains of high-frequency, rapidly repeated clicks. By comparing this response in intact and headless moths, the role of protocerebral auditory inter-neurones suggested by other studies was examined. Individual moths were tested intact and decapitated, and their response differences analysed. Response latency and threshold (dB) did not alter with the removal of the head but response duration and responsiveness to stimulus trains were significantly reduced in headless moths. These data are interpreted as suggesting the existence of a reflex arc connecting the moth's tympanic organ (ear) with its sound-producing structure (tymbal), and as providing preliminary evidence that the role of higher-order interneurones is primarily that of response reinforcement.  相似文献   

12.
The lengths and widths of body parts are influenced to a considerable extent by the environment. Along with increasing altitude, wings of arthropods degenerated or even disappeared so that a trend of degeneration on their acoustic systems appeared. We measured 131 adult skulls of daurian pikas, Ochotona daurica , in order to know whether the degeneration will happen in mammals. Our results show that both the size and relative size of auditory bulla of daurian pikas were negatively correlated with altitude and this change was significant. However, the ear length showed an opposite trend. We suggest that lower oxygen concentration, constantly strong winds and lack of resources at high altitude are responsible for the decrease in the size of the auditory bulla. Besides thermoregulation for large different temperatures of day and night in high altitude, larger external ears of the pika help detect the direction of the predator and could compensate for a relatively small bulla.  相似文献   

13.
The aim of this study was to investigate the applicability of acrylamide grafted moth bean starch as controlled release matrix former. Lamivudine was used as model drug and its controlled release tablets were formulated using various concentration of grafted copolymer. The grafted copolymer was tested for acute toxicity and drug-excipient compatibility study. The formulations were evaluated for physical characteristics like hardness, friability, % drug content and weight variations. The in vitro release study showed that the optimized formulation exhibited highest correlation (R) value in case of Higuchi model and the release mechanism study proved that the formulation showed a combination of diffusion and erosion based release process. There was a significant difference in the pharmacokinetic parameters (Tmax, Cmax, AUC, Vd, T1/2 and MDT) of the optimized formulation as compared to the marketed conventional tablet Lamivir®, which confirmed controlled release potential of acrylamide grafted copolymer.  相似文献   

14.
Male silkworm moths, Bombyx mori, move their heads side-to-side during zigzag walking toward a source of sex pheromone. High-speed video analysis revealed that changes in walking direction were synchronized with this head turning. Thus the direction of the walking is indicated by the direction of the head turning. Head turning was regulated by neck motor neurons which innervate the cervical ventral muscles and the ventral muscles through the second cervical nerve. To determine the role of the `flipflop' state transition in spike activity carried by descending interneurons from the brain to the thoracic ganglion, we recorded pheromonal responses simultaneously from flipflop descending interneurons and a single cervical ventral 1 neck motor neuron. The activity of the cervical ventral 1 neck motor neuron was synchronized to that of the flipflop descending interneurons. The cervical ventral 1 neck motor neuron was morphologically identified using confocal imaging. Our results demonstrate that the flipflop signals play an important role in instructing turning signals during the pheromone-mediated behavior in a male B. mori. Accepted: 11 June 1998  相似文献   

15.
Summary The salivary glands of the moth,Manduca sexta, are described, emphasizing correlations between structure and function in an attempt to explain the production of a dilute saliva. Each of the paired glands consists of five distinct regions: protein secreting, fluid secreting, thin duct, bulbous duct, and common duct. Each region constists of a single, ultrastructurally distinct, cell type. It is proposed that the protein and fluid secreting regions produce an enzyme-containing primary saliva isosmotic with the haemolymph; this saliva is modified in the remaining regions of the gland to yield a dilute saliva. Acknowledgements. We thank Professor T. Weis-Fogh for accommodation in the Department of Zoology and Dr. J. E. Treherne for use of A.R.C. facilities. We are especially grateful to Dr. Nancy Lane for encouragement, advice and critical comments and to Drs. M. J. Berridge and S.H.P. Maddrell for helpful discussion. H.A.R. is grateful to Clare College, Cambridge for financial aid.  相似文献   

16.
Real-time quantitative polymerase chain reaction (qPCR) depends on precise temperature control of the sample during cycling. In the current study, we investigated how temperature variation in plate-based qPCR instruments influences qPCR results. Temperature variation was measured by amplicon melting analysis as a convenient means to assess well-to-well differences. Multiple technical replicates of several SYBR Green I-based qPCR assays allowed correlation of relative well temperature to quantification cycle. We found that inadequate template denaturation results in an inverse correlation and requires increasing the denaturation temperature, adding a DNA destabilizing agent, or pretreating with a restriction enzyme. In contrast, inadequate primer annealing results in a direct correlation and requires lowering the annealing temperature. Significant correlations were found in 18 of 25 assays. The critical nature of temperature-dependent effects was shown in a blinded study of 29 patients for the diagnosis of Prader–Willy and Angelman syndromes, where eight diagnoses were incorrect unless temperature-dependent effects were controlled. A method to detect temperature-dependent effects by pairwise comparisons of replicates in routine experiments is presented and applied. Systematic temperature errors in qPCR instruments can be recognized and their effects eliminated when high precision is required in quantitative genetic diagnostics and critical complementary DNA analyses.  相似文献   

17.
Interneurons with dendritic branches in the antennal lobe of the male turnip moth, Agrotis segetum (Schiff., Lepidoptera: Noctuidae), were investigated with intracellular recording and staining methods. Seventeen projection neurons that transmit information from the antennal lobe to higher centers in the brain displayed dendritic arbors in the male specific macroglomerular complex (MGC) and responded to chemical components of the female sex pheromone used in species-specific sexual communication. Most of the projection neurons responded to several of the pheromone components tested, and a precise correlation between the location of the dendritic arborization and the physiological response could not be demonstrated. One MGC-projection neuron fit the definition of blend specialist. It did not respond to the individual components of the behaviorally active pheromone blend, but showed a strong response to the components when combined in the species-specific blend. Some of the projection neurons also showed clear responses to phenylacetaldehyde, a flower-produced compound and/or to (E)-2-hexenal, a common green-leaf volatile. In eight neurons, the axonal projection could be followed to the calyces of the mushroom body, and subsequently to the inferior lateral protocerebrum.Four local interneurons were characterized both morphologically and physiologically. Each neuron arborized extensively throughout the antennal lobe, and each responded to one or several of the pheromone compounds, and/or to one or both of the plant-produced compounds. One of the local interneurons responded exclusively to the pheromone blend, but not to the individual components.Abbreviations AL antennal lobe - AN antennal nerve - CB cell body - E2H (E)-2-hexenal - IACT inner antennocerebral tract - ILPR inferior lateral protocerebrum - LH lateral horn of the protocerebrum - LN local interneuron - MB mushroom body - MGC macroglomerular complex - OACT outer antennocerebral tract - PAA phenylacetaldehyde - PN projection interneuron - RN receptor neuron - Z5-10:OAc (Z)-5-decenyl acetate - Z5-10:OH (Z)-5-decenol - Z5-12:OAc (Z)-5-dodecenyl acetate - Z7-12:OAc (Z)-7-dodecenyl acetate - Z9-14:OAc (Z)-9-tetradecenyl acetate  相似文献   

18.
19.
Summary Auditory brainstem responses (ABRs) were characterized at 37 °C in ground squirrels (Citellus lateralis) which were implanted with recording screws to record ABRs, and a thermistor to record brain temperature. After two weeks ground squirrels were reanesthetized and tone pips and clicks were delivered through a TDH-49 headphone.Recorded ABRs were found to vary in a predictable manner as a function of stimulus frequency and intensity. At intensities above 50 dB SPL, ABRs could be recorded over the range tested (2–32 kHz). An 8 kHz tone pip was the best frequency for recording ABRs at the lowest stimulus intensities. Latencies decreased as stimulus frequencies increased from 4 kHz to 32 kHz.  相似文献   

20.
The developmental threshold and heat-unit requirements for larval eclosion of the winter moth, Operophtera brumata (L.) [Lepidoptera: Geometridae], were determined from experiments involving eggs exposed to various chilling and warming treatments. The developmental threshold was determined to be 4 °C. Eggs which were chilled below the developmental threshold required fewer heat-units for larval eclosion than did eggs not given a chill treatment. Eggs cultured at 14 °C required 470 (±47) degree-days for 50% larval eclosion. However, eggs chilled for 2 weeks at 1 °C and subsequently placed at 14 °C required 382 (±33) degree-days while eggs chilled for 12 weeks at 1 °C and subsequently placed at 14 °C required 156 (±12) degree-days. The results are discussed in relation to chilling intensity, diapause, and physiological-time models.
Résumé Le seuil de développement et la quantité de chaleur nécessaires pour l'éclosion larvaire chez Operophtera brumata (L.) (Lepidoptera: Geometridae) ont été déterminés en exposant les oeufs à différents régimes de refroidissement suivis de périodes de réchauffement. Le seuil de développement déterminé est de 4 °C. Les oeufs placés d'abord à des températures inférieures à celle du seuil de développement demandent moins de quantité de chaleur pour l'éclosion larvaire, que les oeufs qui n'ont pas été exposés à de basses températures. Les oeufs maintenus à 14 °C demandent 470 (±47) degrés-jours pour permettre 50% d'éclosion. Cependant, des oeufs maintenus pendant 2 semaines à 1 °C, puis à 14 °C, exigent 382 (±33) degrés-jours; ceux placés pendant 12 semaines à 1 °C, puis à 14 °C, en exigent 156 (±12). Les résultats sont discutés en relation avec l'intensité du refroidissement, la diapause et les modèles physiologico-temporels.
  相似文献   

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