Flowering Induced on Young Loblolly Pine Grafts by Out-of-Phase Dormancy

Loblolly pine trees 3 to 7 years old grown in a heated greenhouse under a 20-hour photoperiod had quiescent buds induced by lowering the temperature and shortening the photoperiod. This treatment resulted in the formation of both male and female strobili. Overall, 38 percent of the ramets produced females, and 68 percent produced males. There was no significant difference in the frequency of flowering among 3-, 5-, and 7-year-old scions.     

Genetic method for the preferential elimination of females of anopheles albimanus

Recent field experiments demonstrated the possibility of using the sterile male method for the control of Anopheles albimanus Wiedemann, the most important vector of human malaria in Central America. Until now there was no practical method for excluding females from the releases of sterile males. A genetic method was developed for the preferential elimination of females during any of the four life stages. This genetic sexing system utilizes propoxur (o-isopropoxyphenyl methyl-carbamate) susceptibility as a recessive conditional lethal a T(Y:2R) translocation, and an In(2R)inversion. The propoxur resistance allele (dominant) was linked to the Y chromosome via a radiation-induced translocation, and genetic recombination was suppressed by inversions. In one of the strains produced, 99.7 percent of the females are eliminated when treated with propoxur, without male loss.     

Bile Acid secreted by male sea lamprey that acts as a sex pheromone

We show that reproductively mature male sea lampreys release a bile acid that acts as a potent sex pheromone, inducing preference and searching behavior in ovulated female lampreys. The secreted bile acid 7alpha,12alpha,24-trihydroxy-5alpha-cholan-3-one 24-sulfate was released in much higher amounts relative to known vertebrate steroid pheromones and may be secreted through the gills. Hence, the male of this fish species signals both its reproductive status and location to females by secreting a pheromone that can act over long distances.     

Recognition of H-2 types in relation to the blocking of pregnancy in mice

Inbred BALB/c females were mated and subsequently exposed in a divided cage to "stimulus" males or females whose H-2 type was similar or dissimilar to the stud male's. The incidence of pregnancy blocking was considerably higher when stud and stimulus males differed in H-2 type than when they did not. Similar results were obtained with urine samples of H-2 identical and nonidentical males. Females exposed after mating to other females whose H-2 type differed from the stud male, under the same experimental conditions, also showed an appreciable incidence of pregnancy block. It is therefore concluded that chemosensory recognition of H-2 types affects the reproductive hormonal status of the pregnant female.     

Microgeographic prediction of polygyny in the lark bunting

Field experiments on breeding populations of lark buntings (Calamospiza melanocorys) in South Dakota support the hypothesis that polygyny is promoted by a high variance in quality among male territories. Among these birds protection of the nest site from solar radiation is the major indicator of quality: nestling survival was significantly correlated with nest-site cover, and experimental increase of shading resulted in higher reproductive success. Males with superior territories attracted two mates, whereas those with poor territories failed to attract any. Secondary females had fledging success at least equal to that of contemporaneous monogamous pairs. On the sole basis of a shading score for each territory, the mating status of males (polygynous, monogamous, or bachelor) was predicted accurately in new areas of Colorado and North Dakota before females arrived.     

河北农业大学新生心理健康状况调查结果与分析

使用“大学生人格健康调查表”（UPI）对河北农业大学2006级的7202名新生进行调查,结果显示：河北农业大学新生中,一类学生筛选率为6％,二类学生筛选率为17．8％。男生心理健康状况好于女生,来自城镇的学生心理健康状况好于来自农村的学生,独生子女个体心理健康状况好于非独生子女个体。农大新生选择频次最高的题目是“缺乏自信”,困扰他们的问题主要集中于情绪方面。     

DNA (cell number) and protein in neonatal brain: alteration by maternal dietary protein restriction

Female rats were maintained on 8 or 27 percent protein diet by a pair-feeding schedule for 1 month before mating and throughout gestation. The brains of newborn rats from females on the 8 percent protein diet contained significantly less DNA and protein compared to the progeny of the females on the 27 percent diet. The data on DNA indicate that there are fewer cells; the protein content per cell was also lower. If, at birth, the brain cells are predominantly neurons, and their number becomes final at that time, then such dietary restriction may result in some permanent brain-neuron deficiency. This quantitative alteration in number as well as the qualitative one (protein per cell) may constitute a basis for the frequently reported impaired behavior of the offspring from protein-deprived mothers.     

刺近隅蛛雄蛛可通过蛛网识别雌蛛的生殖状态

化学通讯被认为是结网类蜘蛛两性间交流的主要方式,但对结漏斗网蜘蛛两性间的交流方式却少有研究.在了解刺近隅蛛Aterigena aculeata的求偶和交配过程的基础上,验证了处女雌蛛蛛网可以触发雄蛛的求偶行为,表明处女雌蛛蛛网上存在着某种化学物质,即性信息素.继而,将雄蛛置于不同生殖状态的雌蛛蛛网上,发现雄蛛面对处女雌蛛蛛网时的求偶延迟时间最短;已交配雌蛛蛛网也可以引起求偶,但延迟时间较长;而亚成体雌蛛和雄蛛的蛛网均不能触发求偶反应.表明雄性刺近隅蛛可以通过蛛网判断出它靠近的这头蜘蛛是否适合自己进行交配.漏斗蛛和其他结网类蜘蛛类似,化学通讯在两性交流过程中起着非常重要的作用.     

烟蚜茧蜂触角的超微结构与冷藏对触角的影响

【目的】明确烟蚜茧蜂（Aphidius gifuensis）触角和触角感觉器的外部形态及低温冷藏对其触角的影响,为烟蚜茧蜂的有效利用提供依据。【方法】采用扫描电镜观察正常羽化的烟蚜茧蜂雌、雄蜂触角的超微结构,比较雌、雄蜂触角感觉器的差异。将处于老熟幼虫期的烟蚜茧蜂在4℃低温下分别冷藏7、14、21和28 d,冷藏后用乙醇对样品进行脱水处理,并在扫描电镜下观察低温冷藏对烟蚜茧蜂触角外部形态及触角感觉器的影响。【结果】烟蚜茧蜂雌、雄成蜂触角外部形态相似,均属于丝状触角。雄蜂触角平均长度略长于雌蜂,雌蜂触角多为17节,雄蜂触角多为19节。成蜂触角上共有6种类型的感觉器：毛形感觉器、刺形感觉器、板形感觉器、Böhm氏鬃毛、腔锥形乳突状感觉器和锥形感觉器。毛形感觉器I主要分布在触角鞭节上,是触角上分布最广、数量最多的感觉器。板形感器主要分部在鞭节上,雄蜂从第1鞭节开始出现,雌蜂从第2鞭节开始出现。腔锥形乳突状感觉器II只存在于雄蜂触角上。雌、雄蜂感觉器的数量存在差异,雌蜂的刺形感觉器I数量多于雄蜂,雄蜂的刺形感觉器II和板形感觉器的数量则多于雌蜂。低温处理14、21、28 d后,板形感觉器、腔锥形乳突状感觉器均表现畸形,且触角最后两节分节不明显,有愈合成一节的趋势。冷藏28 d后,54%雄性触角不能正常分节,由正常情况下的19节而愈合为18节;69%的雌性触角不能正常分节,由正常情况下的17节而愈合为16节。【结论】烟蚜茧蜂触角属于丝状触角,共有6种类型感觉器。雄蜂触角长于雌蜂,感觉器的分布特点相似。低温冷藏对烟蚜茧蜂某些触角感觉器形态及触角末两节分节有显著影响。为减少冷藏对烟蚜茧蜂的伤害,应尽量避免在蛹期以前的虫态低温保存蜂种,且应缩短冷藏时间。     

普通大蓟马子代性比对同种成虫气味的响应

为了探究同种成虫的气味对普通大蓟马(Megalurothrips usitatus)交配期间性比调节的影响,设置对照（无气味）、已交配雌虫、未交配雌虫和已交配雄虫等4种气味源,分别处理单对刚羽化成虫24 h,然后用幼嫩豇豆(Vigna unguiculata)豆荚单头饲养被测雌虫,观测每日所产子代的性别和数量,计算子代性比。结果表明:已交配雌虫气味处理的子代雌虫数（22.80头）最少,跟其他处理差异显著。同对照的子代性比（0.31）相比,已交配雌虫和未交配雌虫的气味分别导致子代性比显著提高和降低,子代性比分别为0.48和0.22,而已交配雄虫气味对子代性比无显著影响。4个处理中,仅已交配雌虫气味处理的雌虫在产卵最后1天的日性比达到1.00,即雌虫体内的精子已消耗殆尽。成虫气味源对雌虫产卵天数没有明显影响。实验结果说明,普通大蓟马在交配期间能依靠嗅觉判别周边雌虫的交配状况,然后通过调控雌虫的获精数量,实现对子代性比的自调节。     

Sex ratio of sea turtles: seasonal changes

Sex ratios of hatchling loggerhead turtles Caretta caretta taken from South Carolina and Georgia ranged from no females in nests laid in late May to 80 percent females in those laid in early July; the sex ratio decreased to 10 percent females in nests laid in early August. These seasonal changes are consistent with the role of temperature in directing sexual differentiation in various reptiles. The data have implications for understanding the demography of sea turtles and for their conservation.     

Social control of sex reversal in a coral-reef fish

Males of Labroides dimidiatus control the process of sex reversal within social groups. Each group consists of a male with a harem of females, among which larger individuals dominate smaller ones. The male in each harem suppresses the tendency of the females to change sex by actively dominating them. Death of the male releases this suppression and the dominant female of the harem changes sex immediately. Possible genetic advantages of the system are considered.     

Plasma testosterone levels in the male rhesus: influences of sexual and social stimuli

Four adult male rhesus monkeys were provided access individually to a group of receptive females. Each male assumed dominance and engaged in frequent copulations. Plasma testosterone levels increased two- to threefold during this period. Next, each male was subjected to sudden and decisive defeat by a large all-male group, and plasma testosterone fell following this experience. Two males were later reintroduced to the females, and plasma testosterone rose rapidly to the previous elevated levels.     

Pheromonally induced sexual maturation in females: regulation by the social environment of the male

Social subordination, which suppresses gonadal function in juvenile and adult male house mice, also suppresses the activity of an androgen-dependent urinary pheromone that accelerates the rate of sexual maturation in juvenile females. Pheromone production may also be suppressed by the presence of pregnant or lactating females. This suggests that the social environment may influence the fertility of population females by altering urinary pheromone activity in the male.     

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.     

北部湾多鳞鱚生长与死亡参数的估算

利用2008年3-9月北部湾底拖网和刺网渔获物中采集的样本,对北部湾多鳞鱚的生长、死亡特性进行了初步研究,并利用单位补充量产量模型对多鳞鱚渔业的开发状态进行了评估。结果表明：北部湾多鳞鱚优势体长为100—130mm,占60．71％;优势体重为5～25g,占83．96％;雌性个体略大于雄性个体,性比为1：1．36,雌雄个体数量不平衡;von Bertalanffy生长方程的参数分别为：k=188．6mm,K=0．51,t0=-0．32;体重的生长拐点年龄为1．86龄;总死亡系数、自然死亡系数和捕捞死亡系数分别为2．58、1．217和1．36;渔业生物学参考点R0.1和Fmax的值分别为0.34和0．50,渔业资源已处于过度利用状态。     

计算“全同胞—半同胞”混合家系亲缘相关的近似公式

一个雄亲与数个雌亲相配所组成的家系是一个全同胞——半同胞混合的家系。雌亲内的后代是全同胞,雌亲间的后代是半同胞,这样一个家系内的亲缘相关随着配种的雌亲数和每个雌亲的后代数量的不同而变化。本文提出了计算这种混合家系亲缘相关的一个近似公式,并证明即使是对后代作随机抽样的情况下也是适用的。     

Drosophila males contribute to oogenesis in a multiple mating species

Two species of Drosophila that differ in their ecology and mating systems have been compared with respect to male contribution to the somatic tissues and developing oocytes of females. In the species Drosophila mojavensis females remate daily, exhibit a copulatory plug, and have been shown to obtain a contribution from the male ejaculate. In contrast, Drosophila melanogaster males do not contribute to females. Female Drosophila melanogaster do not remate as frequently as Drosophila mojavensis females nor is a copulatory plug formed.     

烟蚜茧蜂的交配行为研究

[目的]明确烟蚜茧蜂的交配行为,探讨雌蜂传递的线索对引发雄蜂交配行为的作用,为烟蚜茧蜂的规模化繁殖和应用提供理论基础.[方法]在室内显微镜下和温室繁蜂棚内直接观察烟蚜茧蜂的交配行为,设死亡处女雌蜂(n=19)、碾碎的雌蜂腹部(n=15)、接触过处女雌蜂的滤纸(n=15)、仅提供雌蜂视觉线索(n=20)和空白对照(n=20)5个不同的试验处理,观察雌蜂传递的嗅觉和视觉线索对引发雄蜂求偶行为的作用.[结果]雄蜂交配行为包括接近、求偶、爬背、敲打触角、交配试探、插入、交配、分离,处女雌蜂交配行为包括逃跑和拒绝交配或接受交配、交配、休息.雄蜂与处女雌蜂的交配过程可划分为搜寻和求偶、交配前期、交配和交配后期4个阶段,且试图交配的雄蜂求偶成功后一般能够与处女雌蜂完成整个交配过程.雄蜂会试图与交配过的雌蜂、死亡的雌蜂发生交配行为,但仅出现交配前期.接触过活体处女雌蜂的滤纸和压碎的雌蜂腹部能够引发雄蜂强烈的振翅反应,而密闭在透明容器中的处女雌蜂不能引发雄蜂的振翅反应.[结论]烟蚜茧蜂的交配行为由—系列固定行为组成,雌蜂传递的嗅觉线索是引发雄蜂求偶行为发生的关键因素,雌蜂腹部是短程雌性性信息素产生的来源.     

骆驼福斯盘尾丝虫病组织病理学观察

为更有效地对骆驼盘尾丝虫病进行防治,利用流行病学调查和常规病理学观察的方法,对骆驼盘尾丝虫病进行研究。结果表明:内蒙古阿拉善左旗骆驼盘尾丝虫病平均感染率为85.4%,感染强度为1~15峰-1,虫体形成的结节分布在骆驼的颈项韧带处;共收集到209个结节,它们的形态和质地各不相同,软的结节内形成纤维组织囊腔,硬的结节内形成钙化灶;骆驼年龄段不同,结节的分布呈不同变化;病理组织学观察显示,囊腔周围有各种炎性细胞侵润,囊腔内有不同状态的雌虫虫体,骆驼盘尾丝虫病表现为骆驼的寄生虫性肉芽肿。