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131.
132.
ANNE MUST ENNO MERIVEE MARIKA MÄNd ANNE LUIK MIKK HEIDEMAA 《Physiological Entomology》2006,31(3):278-285
Abstract. Cold cells innervating antennal campaniform sensilla of the ground beetles Pterostichus oblongopunctatus (Fabricius, 1787) and Poecilus cupreus (Linnaeus, 1758) belonging to the tribe Pterostichini fire at a stationary rate of 22–23 imp s−1 at 23 °C. In P. oblongopunctatus , there is a strong negative correlation between the stationary firing rate of the cold cell and temperature. By contrast, no relationship between the firing rate and temperature is observed in P. cupreus. Mean peak frequencies, reaching up to nearly 500 Hz, and first-second firing rates, reaching up to 140 imp s−1 , are observed at the beginning of the phasic-tonic response to rapid cooling of the cold cells of P. cupreus, which are significantly higher than those for P. oblongopunctatus . However, firing rates of the cold cells of the two ground beetles studied do not differ 3 s later, during the tonic stabilization period of the response. The length of the long interspike period, lasting up to several seconds, at the beginning of rapid warming, is a positive function of the extent of change in temperature, and is longer in P. oblongopunctatus than in P. cupreus . These differences in the responses of the cold cells are related to the ecological preferences of the two ground beetles. 相似文献
133.
134.
Ignacy Kitowski 《Journal of Ethology》2005,23(1):3-8
Play bouts and active training of juveniles by Montagus harrier (Circus pygargus) adults in the post-fledging period were observed. Fledglings often played with prey and with a variety of inanimate objects such as bits of moss, regurgitated pellets, sticks and a wad of hay. Inanimate objects selected for play were, in length, very similar to the common vole (Microtus arvalis), which is the most common prey of the species during their breeding period. Some recently fledged individuals were trained to capture invertebrate prey by adults demonstrating techniques for the fledglings and thus develop their hunting skills. Training sessions took place only in the foraging areas of the adult birds. 相似文献
135.
Flavin-binding, Kelch repeat, F-box (FKF1) protein is a photoreceptor to regulate flowering of Arabidopsis. The protein has a light, oxygen and voltage (LOV)-sensing domain binding a flavin mononucleotide. The photo-activation of the domain is an indispensable step to initiate the cellular signaling for flowering. In the present study, a LOV-containing polypeptide of FKF1 was prepared by an overexpression system, and the quaternary structure of it was studied by size exclusion chromatography and small-angle X-ray scattering. The apparent molecular weight from chromatography suggested a globular trimeric or an anisotropic-shaped dimeric association of the polypeptide in solution. The scattering experiment demonstrated a dimeric association of the polypeptides with an elongated molecular shape displaying the radius of gyration of 27 A and the maximum dimension of 94 A. The molecular shape simulated from scattering profiles suggests an antiparallel association of the LOV domains in the dimer. Though the absorption spectrum of blue-light irradiated polypeptide was stable in the photoactivated state for a long period, the scattering profiles showed very small changes between the dark and light conditions. Based on the homologies in the amino-acid sequences and the scattering profiles, these results are discussed in connection with the structures and function of LOV domains of phototropin. 相似文献
136.
福建柏开花与结实物候期的研究 总被引:4,自引:0,他引:4
福建柏1年2次花期,春花期4—5月,果期当年10月,种子无生活力;秋花期9~10月,果期翌年10月,种子有生活力,有效花期在秋季。开花结实的生物学及物候学特性与适生区的地点、地类、海拔、温度等地理气候因子紧密相关,总体变异规律:秋花期、球果成熟期、种子散落期山区比半山区早,半山区比丘陵区早,高海拔地区比低海拔地区早.发芽率山区〉半山区〉丘陵区。 相似文献
137.
Hatching order and size-dependent mortality in relation to brood sex ratio composition in chinstrap penguins 总被引:2,自引:0,他引:2
Fargallo Juan A.; Polo Vicente; de Neve Liesbeth; Martin Jose; Davila Jose A.; Soler Manuel 《Behavioral ecology》2006,17(5):772-778
The differential environmental sensitivity of the sexes hasstrong implications in the evolutionary history of species asit can alter sexual size dimorphism, population sex ratios,and the faculty of parents to manipulate offspring sex in relationto environmental conditions. We studied sexual differences inhatching patterns and evaluated sex- and size-related mortalityin relation to hatching order and brood sex ratios in the chinstrappenguin Pygoscelis antarctica, a moderately size-dimorphic species,with a modal clutch size of 2 eggs. We found that male, second-hatched,and large eggs showed shorter hatching periods than female,first-hatched, and small eggs. We also found a male-biased mortalityof nestlings in the colony. However, male mortality patternsdiffered depending on the brood sex ratio composition. Mortalityof male chicks in all-male broods was higher than in mixed broodsand higher than female mortality in all-female broods. Contrary,females from mixed brood showed higher mortality than theirmale nest mates and higher too than females in all-female broods.Second-hatched chicks also suffered from higher mortality thanfirst-hatched chicks. Our results indicate that both the superiorcompetitive capacity and the higher energy demand of the largersex constitute 2 causal factors explaining patterns of sex-biasedmortality. Both factors occur in the same species and in differentsituations of sibling competition shaped by brood sex ratiocomposition. This study constitutes a good example of how patternsof sex-related mortality can vary depending on nest environmentalcircumstances. Furthermore, our study suggests that hatchingperiod can be a mechanism underlying sexual differences in theembryonic period of birds. 相似文献
138.
油菜田害虫调查及蚜虫防治药剂筛选 总被引:1,自引:0,他引:1
田间调查试验表明,合肥市油菜田害虫的发生种类有15种,主要害虫为蚜虫类、油菜潜叶蝇Phytomyza horticola、小菜蛾Plutella maculipennis和菜青虫Pieris rapae。其中,以蚜虫类危害最重,全生育期在冬、春季各有一个峰值。油菜苗期以萝卜蚜、小菜蛾危害较重,后期以桃蚜Myzus persicae、油菜潜叶蝇危害较重。蚜虫防治药剂筛选试验表明,70%吡虫啉水分散粒剂防治蚜虫药效高,持效期长,且对油菜安全,10%烯啶虫胺可溶液剂和25%吡蚜酮可湿性粉剂防效也较好,可作为70%吡虫啉水分散粒剂的轮换药剂。 相似文献
139.
140.
Leonid Kalichman Ida Malkin Eugene Kobyliansky 《International Journal of Anthropology》2006,21(3-4):253-263
In the present cross-sectional study of the Chuvashian rural population, we examined the secular trends of age at menarche,
the age at menopause, the reproductive period, and the age of the first marriage of Chuvashian women. The cohort included
745 women aged 18–90 years; age at menarche (N = 653) ranging from 10 to 24 years (mean 15.42 ± 2.11). Data regarding menopausal age was obtained from 316 women born between
1920 and 1950 (mean 48.5 ± 4.6). Statistical analyses included the maximum likelihood estimation and a Whiskers plot. Women
born during the second through the fourth decade of the 20th century showed increasing mean values of age at menarche from
15.4 (second decade) up to 16.5 (fourth decade) and after that a decrease of the mean values to 14.0 (ninth decade). The mean
values of menopausal age increased from 47.0 (women born from 1920 to 1925) to 49.3 (born from 1945 to 1950). Age at first
marriage showed a trend of decreasing age. Our study demonstrated secular trends of age at menarche in Chuvashian women who
had matured after World War II and also confirmed secular trends of increased age at menopause and the duration of the reproductive
period. Women, whose maturation was during or immediately after World War II, showed a higher age at menarche and a higher
dispersion of age at menopause. 相似文献