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1.
Summary Female choice mating experiments showed virgin femaleD. melanogaster of the 3Adh genotypes chose heterozygous (Adh F /Adh S ) males most commonly. Inseminated females chose mates randomly, but the likelihood of a female remating was genotypically dependent.Acknowledgment. Financial support was provided by the Australian Research Grants Commitee.  相似文献   

2.
Summary Both male and femaleOrchesella cincta (Collembola) were able to discriminate between spermatophores of different origin. Females chose spermatophores deposited by closely related males while males preferentially destroyed spermatophores of other males.  相似文献   

3.
科技发展模式是对国家科技发展的高度概括与总结,选择合理的科技发展模式是实现国家整体发展战略的重要组成部分。本文深入剖析了美国科技发展模式的基本特点及形成条件,为我国制定21世纪的中长期科技发展战略提供了一些的意见与建议。  相似文献   

4.
在深入研究多级树集合分裂编码(SPIHT)的基础上提出了一种安全高效的图像加密算法。首先,重点分析了SPIHT的码流结构以及各部分数据对解码的影响,确定了重要数据并对其进行加密。其次,改变加密层数K控制加密强度,从而进一步提高了加密效率。最后,在对LIS扫描过程中引入了混乱机制,降低了码流相关性,使得算法更加安全。实验表明:该算法安全性高,加密速度快,仅需加密原图数据量的2.3%左右便可以达到很好的加密效果,满足格式兼容性要求并且能够适应网络实时传输。  相似文献   

5.
Summary This paper reports evidence for a hormonal regulation of a new rat serum protein (female specific protein, FP) which is only demonstrable in female rats. Male and female rats were treated with testosterone and estrogen. The FP was assayed with immunological methods. The following results were obtained: 1. In testosterone-treated females the serum level of FP is reduced significantly. 2. In estrogenized males the FP was distinctly demonstrable but not in the control males.  相似文献   

6.
Stress during gestation significantly increased estrous cycle length in female offspring as adults, primarily by lengthening the estrus-metestrus stage. Therefore, prenatal stress may disturb the hormonal milieu of the female fetus during a critical hypothalamic differentiation stage.  相似文献   

7.
S L Manocha 《Experientia》1979,35(1):96-98
The physical growth and brain development of the captive bred male and female squirrel monkeys have shown that the male grows at a significantly faster rate with respect to these parameters in the postnatal life, starting from preweaning stage as compared to the female infant. During the prenatal life the male and the female fetuses grow at similar rates and show comparable brain development as indicated by its weight.  相似文献   

8.
Summary Stress during gestation significantly increased estrous cycle length in female offspring as adults, primarily by lengthening the estrus-metestrus stage. Therefore, prenatal stress may disturb the hormonal milieu of the female fetus during a critical hypothalamic differentiation stage.  相似文献   

9.
The salience of a short conspecific song phrase versus a long one or a short heterospecific song phrase was tested in females of the common domesticated canary (Serinus canaria). All phrases were computer-edited. The copulation solicitation displays (CSD) served as an index of female responses. The results support the hypothesis that female canaries are able at the onset of a song phrase stimulus: 1) to respond to a conspecific one by displaying high levels of CSD and 2) to discriminate a conspecific from a heterospecific one. Proximal explanations examine the link between perceptual processes and phonology in the canary. Functional explanations investigate the relations between female responsiveness and the process of pair formation.  相似文献   

10.
Serum from pregnant female Salamandra salamandra inhibits the cytotoxic reaction from the mother towards its larvae. Such a serum accelerates the allograft rejection reaction. In vitro studies show that a serum from pregnant female inhibits the cytotoxic reaction of host spleen cells towards epithelial cells of the donor of the graft.  相似文献   

11.
Summary The physical growth and brain development of the captive bred male and female squirrel monkeys have shown that the male grows at a significantly faster rate with respect to these parameters in the postnatal life, starting from preweaning stage as compared to the female infant. During the prenatal life the male and the female fetuses grow at similar rates and show comparable brain development as indicated by its weight.Acknowledgments. This work was supported by USPHS Grants RR-00165 and HD-06087 from National Institutes of Health. The technical assistance of Mrs Judie Wells is greatly appreciated.  相似文献   

12.
The submandibular gland of male mice contained 18% more DNA, 34% more RNA and 63% more protein than that of female mice. After a 48-h fasting, the percent loss of gland weight, protein, RNA and DNA was greater in the female than in the male.  相似文献   

13.
Summary In normal freshly moulted insects Spermotozoa are present and pass into the vas deferens after 24 h. They show morphological changes when inside the female genital tract. Sterility caused by Acorus calamus oil vapours is due to agglutation, malformation and immobility of sperms, which makes the sperms unable to undergo morphological differentiation in the female tract.  相似文献   

14.
Summary Injections of male accessory gland material fromAedes aegypti into the hemocoeles of virgin female mosquitoes indicate that the potency of the secretion is equivalent to the amount of semen which a male normally places within the female. This estimation is far less than had been previously calculated. It is suggested that the termmatrone for male accessory gland material is inappropriate since it does not convert a maid into a matron but prevents reinsemination of an impregnated female.Scientific Article No. A2098, Contribution No. 5054 of the Maryland Agricultural Experiment Station.  相似文献   

15.
Oral administration of p-coumaric acid to estrogen-primed immature female mice exerts neither estrogenic nor anti-estrogenic activity, but when it is administered to cyclic female mice in single dose at proestrus or in repeated doses, induces alteration in estrus cycle, ovarian and uterine weight and structure.  相似文献   

16.
Summary H-Y antigen was found to be increased in lymphocytes from 10 female 21-hydroxylase deficiencies, suggesting a correlation between the degree of virilization of these patients and their H-Y+lymphocytes proportions. Furthermore, these findings demonstrate the ability of a 46,XX female subject to produce, in some circumstances, an excess of H-Y antigen.  相似文献   

17.
H-Y antigen was found to be increased in lymphocytes from 10 female 21-hydroxylase deficiencies, suggesting a correlation between the degree of virilization of these patients and their H-Y + lymphocytes proportions. Furthermore, these findings demonstrate the ability of a 46,XX female subject to produce, in some circumstances, an excess of H-Y antigen.  相似文献   

18.
The fertility of experimental triploid worms has been studied in Eisenia foetida Sav. This study has led us to the conclusion that the female germ line is abortive while the male germ line may as an exception take part in fertilization. Histological controls have confirmed the differentiating ability of the male line and the break in the development of the female line.  相似文献   

19.
In the newborn female Rat, no transient LH and FSH serum surges were observed between 0 and 2 hrs., as compared with the newborn male. In the newborn female, a progressive increase in serum gonadotropins was observed between 2 and 6 hrs. These results indicate that, at birth, the pituitary-gonadal axis reacts in a different way in male and female Rats.  相似文献   

20.
Summary One major antigen, present in female cuticle, female blood and eggs, is revealed by the antiserum against soluble cuticular proteins of adults locusts, and by all the antisera against vitellin or vitellogenin. It is not revealed by the specific antiserum against diglyceride-binding lipoprotein. The presence of this major antigen in the cuticle depends on the presence of vitellogenin in the blood.  相似文献   

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