Infantile experience with suckling odors determines adult sexual behavior in male rats

Because infant rats learn about odors that elicit suckling, and because certain chemosensory cues that help elicit mating behavior in adults are similar to those that elicit suckling, an experiment was undertaken to assess the influence of suckling-associated odors experienced during infancy on adult sexual behavior. Rat pups lived with and suckled dams whose nipple and vaginal odors were altered with citral, a lemon scent. The rats were weaned and never exposed again, until testing, to citral or females. At about 100 days of age, the males were paired in mating tests with a normal sexually receptive female or with a sexually receptive female that had been treated perivaginally with citral immediately before testing. The males ejaculated readily when paired with citral-treated females but were slow to achieve ejaculation when paired with normal females. These findings implicate an infantile experience as a determinant of adult sexual behavior in a mammal.     

Charge-mosaic membranes: enhanced permeability and negative osmosis with a symmetrical salt

Charge-mosaic membranes are prepared by embedding a single layer of alternating cation and anion exchange beads in silicone resin. Membranes made in an identical manner but containing only one type of exchanger serve as controls. The mosaic membranes are 50 to 100 times more permeable to potassium chloride than the controls; and furthermore they give rise to net volume flow from concentrated to dilute solutions of potassium chloride in the absence of a pressure gradient ("negative osmosis"), whereas the controls exhibit normal osmotic behavior. The negative reflection coefficients of the mosaics suggest potential applications in desalination.     

Pheromones: isolation of male sex attractants from a female primate

Fractionation of vaginal secretions from rhesus monkeys by partitioning and chromatographic procedures, combined with behavioral studies, demonstrates that short-chain aliphatic acids are responsible for stimulating the sexual behavior of males. Injection of estradiol into ovariectomized females increases the concentration of volatile acids in secretions which will then sexually stimulate these male primates.     

Genomic exclusion: a rapid means for inducing homozygous diploid lines in Tetrahymena pyriformis, syngen 1

Genomic exclusion is an abnormal form of conjugation occurring between cells with defective micronuclei and normal cells with diploid micronuclei. The progeny are heterocaryons; each cell has an old macronucleus but a new diploid micronucleus derived from one meiotic product of the normal mate. Such cells express genes found in the old macronucleus, are sexually mature, and can be specifically selected. When inbred, they give rise to lines genetically homozygous at all known loci.     

Transmission of a female sex pheromone thwarted by males in the spider Linyphia litigiosa (Linyphiidae)

When a male Sierra dome spider (Linyphia litigiosa) encounters a virgin female that has been sexually mature for 7 to 10 days, he rapidly packs the silk of her web into a tight mass. This behavior hinders evaporation of a male-attractant chemical that such highly receptive females apply to their webs. The male thereby reduces the likelihood that his mating partner will attract rival males.     

Fossilized eggs in a pennsylvanian blastoid

A single specimen of Pentremites rusticus (Echinodermata, Blastoidea) from the Early Pennsylvanian of Oklahoma has hundreds of apparent eggs in one of its abnormal anal hydrospire groups. This rare occurrence suggests that female blastoids in this sexually dimorphic species had modified their anal hydrospiresfor brooding eggs instead of for normal respiration.     

Competition Among Courting Male Moths: Male-to-Male Inhibitory Pheromone

The behavioral function of a pheromone released by males of the army-worm moth Pseudaletia unipuncta was investigated both in laboratory wind-tunnel experiments and in experiments with moth-baited traps in the field. Such male moth scents have been thought to act at close range as sexual stimulants for females of the same species. However, the only obvious effect of the P. unipuncta male pheromone was upon other males, decreasing their tendency to approach sexually receptive, pheromone-releasing females and to exhibit copulatory behavior when near those females. The adaptive significance of the male pheromone may be related to the increased reproductive efficiency that results if multiple males are prevented from competing for a single female.     

Enhancement of sexual motivation in male rats by yohimbine

Yohimbine hydrochloride, an alpha 2-adrenoceptor antagonist, increased sexual motivation in male rats as evidenced by increased mounting performance in mating tests conducted after genital anesthetization, increased percentage of male rats ejaculating in their first heterosexual encounter, and induction of copulatory behavior in sexually inactive male rats. These observations lead to the suggestion that alpha-adrenoceptors are important modulators of sexual arousal in intact male rats. These results indicate that pharmacological treatment of sexual (libido) dysfunction may be useful.     

Tolerance develops to the disruptive effects of delta 9-tetrahydrocannabinol on primate menstrual cycle

Long-term exposure of sexually mature female rhesus monkeys (Macaca mulata) to thrice weekly injections of delta 9-tetrahydrocannabinol resulted in a disruption of menstrual cycles that lasted for several months. This period was marked by an absence of ovulation and decreased basal concentrations of gonadotropin and sex steroids in the plasma. After this period, normal cycles and hormone concentrations were reestablished. These studies demonstrate that in rhesus monkeys subjected to long-term treatment with delta 9-tetrahydrocannabinol tolerance develops to the disruptive effects of the drug on the menstrual cycle.     

Age and infertility

Direct evidence on age patterns of infecundity and sterility cannot be obtained from contemporary populations because such large fractions of couples use contraception or have been sterilized. Instead, historical data are exploited to yield upper bounds applicable to contemporary populations on the proportions sterile at each age. Examination of recent changes in sexual behavior that may increase infecundity indicates that sexually transmitted infections, the prime candidate for hypothesized rises in infertility, are unlikely to have added to infecundity to any great extent. These results imply that a woman in a monogamous union faces only moderate increases in the probability of becoming sterile (or infecund) until her late thirties. Nevertheless, it appears that recent changes in reproductive behavior were guaranteed to result in the perception that infecundity is on the rise.     

A sexually dimorphic nucleus in the human brain

A sexually dimorphic cell group is described in the preoptic area of the human hypothalamus. Morphometric analysis revealed that the volume of this nucleus is 2.5 +/- 0.6 times (mean +/- standard error of the mean) as large in men as in women, and contains 2.2 +/- 0.5 times as many cells. Between the ages of 10 and 93 years, the nucleus decreases greatly in volume and in cell number. Although no function has yet been established for this nucleus, it is located within an area that is essential for gonadotropin release and sexual behavior in other mammals.     

转bar基因小麦的抗性遗传及农艺性状分析

【研究目的】以皖麦48和扬麦87158两个小麦品种的转bar基因株系为材料,探讨bar基因在转基因小麦自交后代的遗传表现及对农艺性状的影响。【方法】利用涂叶法和PCR法研究bar基因在转基因植株自交后代T1、T2的遗传表现,并对产量及品质等主要农艺性状进行比较分析。【结果】证实抗除草剂bar基因已经整合到小麦基因组中,并能稳定表达;遗传分析显示bar基因能稳定的遗传给后代,符合孟德尔遗传规律;在产量及品质等主要农艺性状方面,转bar基因小麦与对照相比无显著差异。     

Neonatal castration: influence on neural organization of sexual reflexes in male rats

Most male rats castrated 4 days after birth and given exogenous testosterone in adulthood were sexually motivated but incapable of completing the mating sequence with an ejaculatory response. When tested for sexual reflexes after spinal transection, these animals displayed impairment of genital responses. Similarly treated 12-day castrates exhibited a complete mating sequence and had normal sexual reflexes. Thus neonatal testicular androgen appears to have an organizational influence at the spinal level on neural tissue mediating sexual reflexes.     

渝东北生态涵养发展区留守妇女性传播疾病调查分析

目的 明确渝东北生态涵养发展区留守妇女性传播疾病感染现状及影响因素,完善流行病学监测及管理,为留守妇女性传播疾病防治提供科学依据。方法 随机抽取渝东北城镇及农村地区留守妇女及非留守妇女两组共90人为研究对象（每组45人）,填写生殖健康相关问卷调查,主要包括一般状况、配偶外出打工及回家状况、滋病相关知识了解情况、避孕套使用情况、既往性病感染及就医情况等。实验室检测阴道毛滴虫及白色念珠菌、解脲支原体、沙眼衣原体、淋球菌、梅毒、人类免疫缺陷病毒（HIV）抗体。结果 两组共检测出2例梅毒螺旋体感染、7例沙眼衣原体感染、12例解脲支原体感染、4例淋球菌感染、4例滴虫感染、7例霉菌感染。留守妇女感染性传播疾病风险均要高于非留守妇女,且留守妇女不同年龄和学历水平与性传播疾病患病率有关,20~35岁年龄段和初中及以下学历者患病率均高于36~50岁年龄段和高中学历者（P<0.05）。结论 留守妇女性传播疾病的患病率高,求医就诊率低。加强留守妇女的性传播疾病防治及相关知识的宣传教育,定期健康筛查及干预,有助于降低留守妇女患性传播疾病的风险。     

宫颈癌患者血清可溶性Apo-1／Fas水平变化及其临床意义

目的 观察宫颈癌患者血清可溶性Apo-1／Fas（sApo-1／Fas）水平变化及其临床意义。方法应用酶联免疫吸附试验法（ELISA）对30例正常人及60例宫颈癌患者的血清sApo-1／Fas水平进行检测,并比较20例宫颈癌患者根治术前后血清sApo-1／Fas水平。结果Ⅰ、Ⅱ、Ⅲ、Ⅳ期宫颈癌患者的血清sApo-1／Fas水平均明显高于正常对照组（P〈0．01）;Ⅳ期宫颈癌患者的血清sApo-1／Fas水平明显高于其他各期,Ⅲ期明显高于Ⅱ期,Ⅱ期又明显高于Ⅰ期,差异均有统计学意义（P〈0．01）;宫颈癌患者根治术后的血清sApo-1／Fas水平明显低于术前（P〈0．01）。结论动态检测血清sApo-1／Fas水平可能对判断宫颈癌病情和预后有一定程度的参考意义。     

交配对棉铃虫雌蛾生殖的调控

研究交配对棉铃虫雌蛾生殖的影响，结果表明：（1）有效交配明显刺激卵巢发育与产卵，交配后24h，交配蛾的卵巢与体重比值较同龄处女蛾提高56．6％，交配雌蛾一生产卵量是处女雌蛾的1．8倍，差异极显。大量的卵的产出使交配后雌蛾体重锐减。死亡时只有羽化的45．2％，明显低于处女雌蛾。（2）有效交配极显抑制了雌蛾的求偶，使雌蛾求偶率降低了87．1％。（3）交配使3日龄雌蛾的性信息素在2h后下降91％。（4）已有效交配的雌蛾当晚不再交配，表现出典型的拒绝行为。（5）有效交配雌蛾寿命为10.4d，显短于无效交配的雌蛾（15．6d)。极显短于单头饲养雌蛾（18．9d).     

Conditional use of sex and parthenogenesis for worker and queen production in ants

The near-ubiquity of sexual reproduction in animal species has long been considered a paradox because sexually reproducing individuals transmit only half of their genome to their progeny. Here, we show that the ant Cataglyphis cursor circumvents this cost by using alternative modes of reproduction for the production of reproductive and nonreproductive offspring. New queens are almost exclusively produced by parthenogenesis, whereas workers are produced by normal sexual reproduction. By selectively using sex for somatic growth and parthenogenesis for germline production, C. cursor has taken advantage of the ant caste system to benefit from the advantages of both sexual and asexual reproduction.     

A circadian output in Drosophila mediated by neurofibromatosis-1 and Ras/MAPK

Output from the circadian clock controls rhythmic behavior through poorly understood mechanisms. In Drosophila, null mutations of the neurofibromatosis-1 (Nf1) gene produce abnormalities of circadian rhythms in locomotor activity. Mutant flies show normal oscillations of the clock genes period (per) and timeless (tim) and of their corresponding proteins, but altered oscillations and levels of a clock-controlled reporter. Mitogen-activated protein kinase (MAPK) activity is increased in Nf1 mutants, and the circadian phenotype is rescued by loss-of-function mutations in the Ras/MAPK pathway. Thus, Nf1 signals through Ras/MAPK in Drosophila. Immunohistochemical staining revealed a circadian oscillation of phospho-MAPK in the vicinity of nerve terminals containing pigment-dispersing factor (PDF), a secreted output from clock cells, suggesting a coupling of PDF to Ras/MAPK signaling.     

Thyroid state: effects on pre- and postsynaptic central noradrenergic mechanisms

For hypothyroid rats, spontaneous motor activity was less than that in matched normal controls, and the specific activity of tyrosine hydroxylase in the midbrain was significantly greater than that in controls. Rats made hyperthyroid with thyroxine became hyperactive and showed increased sensitivity to the behaviorally activating effects of norepinephrine administered intraventricularly. In hyperthyroid rats, the specific activity of tyrosine hydroxylase in the midbrain remained within the normal range. These results are consonant with studies that suggested both receptor "tuning" and feedback regulation of activity of enzymes involved in biosynthesis of presynaptic neurotransmitter as methods of regulation of the central catecholamine synapse. These results may also help explain the reported potentiation by thyroid hormone of the antidepressant effects of imipramine.