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21.
Overwintering larvae of multivoltine and univoltine populations of Leptalina unicolor were reared under various constant and fluctuating temperatures superimposed on a photoperiod of either 12 h of light and 12 h of darkness (LD 12:12) or LD 15:9. Diapause of the larvae terminated in midwinter (by early February). All the larvae of both populations pupated after two molts without feeding and the head capsule width of the final instar larvae was smaller than that of the penultimate instar ones. The photoperiod did not significantly affect larval development, but long‐day conditions (LD 15:9) hastened pupal development. The thermoperiod had a significant effect on the development of the multivoltine population. When multivoltine population larvae were kept under a low fluctuating temperature regime (cryophase/thermophase = 14/20°C), the period until adult eclosion was shorter than that under a constant temperature of 17°C. On the contrary, when larvae were kept under a high fluctuating temperature regime (24/30°C), the period until adult eclosion was longer than that under a constant temperature of 27°C. However, the univoltine population did not show such a reaction to the fluctuating temperature. The durations of final instar larva and pupa of the multivoltine population were shorter than those of the univoltine population. The developmental zeros of penultimate and final instar larvae and pupae of the univoltine population were lower than those of the multivoltine population. The head capsule width of penultimate instar larvae and the forewing length of adults of the univoltine population were larger than those of the multivoltine population for both sexes.  相似文献   
22.
We developed 10 microsatellite loci from genomic DNA of a dioecious clonal plant, Dioscorea japonica. Out of 384 clones, 148 contained microsatellite repeats. Polymerase chain reaction primer pairs were designed for 95 of these clones from their sequence data, of which, 10 pairs produced successful amplification. Thirty‐eight individuals were genotyped for allelic diversity. We detected three to nine alleles per locus, and the expected heterozygosity ranged from 0.461 to 0.851.  相似文献   
23.
Endometrial cytology is important not only for observing cytological findings, but also for assessing histological architecture. Therefore, we attempted to produce a histological preparation from the sample using an automatic fixation apparatus (ACF 1000) which employs a membrane filter method. After observation of the cytological features, the cover slip was removed and a paraffin-embedded section was prepared. Producing a histological section from a cytological specimen prepared with the ACF 1000 apparatus was more useful and easier than with the techniques described to date. Peelability of the cell was avoided by using a silane-coated membrane filter. Observation of the same cell cluster as that observed in the cytological sample was also facilitated in the histological section by this technique.  相似文献   
24.
In addition to photoperiod, thermoperiod (or thermocycle) might be an important Zeitgeber for entraining the circadian oscillator controlling adult eclosion rhythm in the Indian meal moth Plodia interpunctella Hübner (Lepidoptera: Pyralidae). This is confirmed by exposing larvae receiving diapause‐preventing treatments to various thermocycles with different means and amplitudes of temperature. The thermocycles investigated in the present study are TC 8 : 16 h, TC 12 : 12 h, TC 16 : 8 h and TC 20 : 4 h, where T and C represent thermophase (30 °C) and cryophase (20 °C), respectively. For all thermocycles, the peak of adult eclosion rhythm occurs at around the mid‐thermophase. This indicates that the larvae use both ‘temperature‐rise’ and ‘temperature‐fall’ signals to adjust the eclosion phase in each thermocycle. The absence (DD) or presence (LL) of light affects this time‐keeping system slightly under the given thermocycle. The rhythmic adult eclosion noted after exposure of larvae to 30 °C DD for 14 days is recorded in the thermocycles (TC 12 : 12 h, DD; mean temperature = 25 °C) with different amplitudes of 27.5/22.5 °C, 26.5/23.5 °C and 25.5/24.5 °C. The peak in adult eclosion advances in time as the amplitude of the temperature cycle decreases. In the temperature cycle of 25.5/24.5 °C, a peak occurs at the end of the cryophase, 2 h before the temperature‐rise. The adult eclosion rhythm is also observed under various thermocycles (TC 12 : 12 h, DD) consisting of different temperature levels (30 to 20 °C) with different amplitudes. It is found that the temporal position of the peak advances significantly when the amplitude of the thermocycle becomes lower.  相似文献   
25.
THE glycolytic intermediate, 2,3-diphosphoglycerate, is an intracellular regulator of the oxygen affinity of haemoglobin1,2. At high altitudes there is a direct relationship between the decreased oxygen affinity of haemoglobin and the increased concentration of diphosphoglycerate in the blood3. This was explained by Benesch et al.4 and Chanutin et al.5, who found that the binding of diphosphoglycerate to haemoglobin reduces the oxygen affinity and by our finding that the concentration of diphosphoglycerate increases when the red cells are incubated under low oxygen tension6,7, thereby releasing oxygen from haemoglobin. For the same reason, the oxygen tension is reduced during the circulation of blood from the pulmonary alveoli to the tissues; the decreased level of the diphosphoglycerate facilitates the binding of oxygen to haemoglobin in the pulmonary alveoli and the increased level of the diphosphoglycerate in the blood of the capillaries decreases the affinity of haemoglobin for oxygen. We have measured the amount of 2,3-diphosphoglycerate and other glycolytic intermediates in arterial and venous blood to test this supposition.  相似文献   
26.
We report on a roundtable event hosted in Singapore that sought to identify some of the ethical and regulatory challenges in translating autologous cell-based interventions, particularly those claiming to involve stem cells, into safe and effective therapies and to propose some solutions to encourage responsible innovation with these products. Challenges are identified in the three areas of cell manufacturing and processing, innovative uses of autologous cells in clinical practice and standards of evidence. Proposed solutions are discussed within a co-operative model of statutory laws and regulations that can enable product development with autologous cells and professional codes and standards that can encourage ethical conduct in clinical practice. Future research should be directed toward establishing regional networks for the development of internationally consistent standards in manufacturing and ethical codes of conduct for innovating with stem cells, and other autologous cells, and fostering ongoing exchange between jurisdictions.  相似文献   
27.
The distribution of the enzymes of cellulose and xylan metabolism namely endo-beta-1,4-glucanase, beta-glucosidase, endo-beta-1,4-xylanase and beta-xylosidase activities, in Reticulitermes speratus (Kolbe) was measured both in the salivary glands and in the major gut sections and along the length of the gut in freshly collected termites. The majority of the endo-beta-1,4-glucanase activity (77.8%) was found in the salivary glands which also contained 23.9% of the beta-glucosidase activity. At least 70% of the remaining activity was located in the anterior section of the hindgut. A small amount of endo-beta-1,4-xylanase activity (2.4%), but no beta-xylosidase activity, was present in the salivary glands. The majority of these activities were in the anterior section of the hindgut. The RQ of freshly collected termites at 25 degrees C was 1.03+/-0.01. Maintaining termites for 16 days on wood, cellulose and xylan showed that the RQ values of termites fed on wood or xylan were not significantly different from those of freshly collected termites but significantly increased when maintained on cellulose. The RQ of starved termites after 11 days was 0.81+/-0.02. There were three effects on protozoan populations of feeding termites xylan for 20 days. One species, Dinenympha parva was not affected, while five others, Pyrsonympha grandis, Holomastigotes elongatum, Dinenympha rugosa, Dinenympha leidy and Dinenympha porteri survived for 20 days but slowly decreased in numbers. The numbers of P. grandis and D. leidy surviving for 20 days were significantly different from those in starved termites. The third group comprising the two large species, Teratonympha mirabilis and Trichonympha agilis and three small species, Pyrsonympha modesta, Dinenympha exilis and Dinenympha nobilis disappeared within 15 days as in starved termites. It is suggested that protozoa in the first two groups are xylanolytic. Protozoan populations on wood and cellulose diets were not markedly affected. Selective removal of the protozoa by u.v. irradiation led to the loss of xylanolytic activity and a life span comparable to starved termites. Copyright 1997 Elsevier Science Ltd. All rights reserved  相似文献   
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29.
This study examined the effects of snowfall on the beginning day of Cryptomeria japonica pollen release and predicted it under global climate change. We used a statistical method in order to investigate when the pollen release would start and how much sooner it would be, by using data on predicted meteorological conditions under global warming in Yamagata City, Japan. Estimation accuracy was improved by multiple regression by using the mean air temperature from January to February and snowfall depth in February. Adding snowfall depth yielded more accurate estimates of the beginning day of pollen release than using air temperature alone. It is possible that the effects of heat insulation and cooling by snow delay the flowering day. Under the predicted global climate change, we expect the beginning day of pollen release to become earlier in Yamagata City. The date would be 8 February in approximately 100 years, compared with 20 February at the earliest now. Eighty years from now the date could be earlier than any date recorded so far.  相似文献   
30.
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