Search Results
Results 401 - 450 of 1019
< 4 5 6 7 8 9 10 11 12 13 14 >
Ostner Julia - - 2003
Masculinization of female genitalia and female intersexual dominance distinguish spotted hyenas (Crocuta crocuta) and Malagasy primates (Lemuriformes) from most other mammals. An unusual prenatal endocrine environment has been proposed to proximately underlie the development of these traits in hyenas. To examine whether female dominance and genital masculinization are similarly enhanced ...
Stockley P - - 2003
Female promiscuity is widespread among mammals, although its function is poorly understood. Recently, much interest has been generated by the hypothesis that female promiscuity, combined with post-copulatory paternity-biasing mechanisms, may function to reduce the costs of reproductive failure resulting from genetic incompatibility. Here, a comparative approach is used to determine ...
Tregenza Tom - - 2003
Direct costs and benefits to females of multiple mating have been shown to have large effects on female fecundity and longevity in several species. However, with the exception of studies examining genetic benefits of polyandry, little attention has been paid to the possible effects on offspring of multiple mating by ...
Brennan P A - - 2003
Male mouse urine contains a pregnancy-blocking chemosignal that causes pre-implantation pregnancy failure in recently mated female mice. However, females are able to recognize the chemosignal of the male with which they mated, preventing it from aborting his own offspring. The individuality of the pregnancy-blocking chemosignal is influenced by genes of ...
Al-Merestani M R - - 2003
Seventy-five female Damascus goats aged between 1.5 and 5.5 years were used to evaluate the effectiveness of the intravaginal sponges and prostaglandin analogue on oestrous synchronization and fecundity; to diagnose pregnancy and to monitor the resumption of the luteal activity. Females were divided randomly, during the breeding season, into three ...
Shingo Tetsuro - - 2003
Neurogenesis occurs in the olfactory system of the adult brain throughout life, in both invertebrates and vertebrates, but its physiological regulation is not understood. We show that the production of neuronal progenitors is stimulated in the forebrain subventricular zone of female mice during pregnancy and that this effect is mediated ...
Vaughan J L - - 2003
OBJECTIVE: To determine relationships between mating behaviour, ovarian follicular state and successful conception in receptive female alpacas. PROCEDURE: Seventy pen matings were observed at a commercial alpaca stud in south-western Victoria. The behaviours observed included time taken to assume sternal recumbency, mating duration, and evidence of nonreceptive behaviour such as ...
Armstrong Linlea - - 2003
The relationship between phenotype and Xq duplications in females remains unclear. Some females are normal; some have short stature; and others have features such as microcephaly, developmental delay/mental retardation, body asymmetries, and gonadal dysgenesis. There are several hypotheses proposed in the literature to explain this variability. We describe a 7-year-old ...
Kusui Takashi - - 2003
The distribution and abundance of marine litter on 26 beaches along the Sea of Japan were investigated from September to November 2000. The mean concentration of stranded litter in Japan and Russia was 2144 and 1344 g/100 m(2), respectively. The mean number of pieces of stranded litter in Japan and ...
Aller Juan F - - 2003
Ultrasonography is widely used in domestic species of camelids, but there is no information about the use of this technique for pregnancy diagnosis and determination of embryonic or fetal losses in the vicuña (Vicugna vicugna). The study was performed in 202 vicuñas (3-year-old females, n = 31; adult females, n ...
Levin R J - - 2003
This article reviews critically studies that describe changes occurring in the female genital tract and pelvic musculature from sexual reflexes activated by stimuli that mimic coitus or induced by sexual arousal. I conclude that apart from the normal erotic pleasure, women gain and maintain vaginal and pelvic functionality from these ...
Johansson Agneta - - 2003
An epidemiological study was performed on a representative sample of the Norwegian youth population (12-18 years; n=3237; response rate 45.2%). The proportion that never gambled was 17.6% and a majority (57.5%) gambled seldom, whereas 24.9% gambled weekly (36.2% of the males and 13.1% of the females). In relation to problematic ...
Ema Makoto - - 2002
Developmental toxicity following administration of dibutyl phthalate (DBP) and its major metabolite, monobutyl phthalate (MBuP), by gavage was determined in Wistar rats. DBP on days 0-8 of pregnancy induced an increase in the incidence of preimplantation loss at 1250 mg/kg and higher and postimplantation loss at 750 mg/kg and higher. ...
Little Anthony C - - 2002
Masculinity and distinctiveness have been found to influence the attractiveness of human male faces. The relationship between masculinity and distinctiveness, however, has received little attention. In Expt 1, we examine how current averaging techniques and manipulated sexual dimorphism influence ratings of attractiveness, masculinity, and distinctiveness. In agreement with previous studies, ...
Shah Akeel - - 2002
We examined the effects of odor exposure in the nest on the offspring's subsequent adult responsivity to pups scented with the same odor or a different odor. It was hypothesized that animals receiving exposure to the odor in the nest would be more maternally responsive to pups scented with the ...
Scott Karen C - - 2002
OBJECTIVE: To determine characteristics of free-roaming cats evaluated in a trap-neuter-return program. DESIGN: Cross-sectional study. ANIMALS: 5,323 free-roaming cats. PROCEDURE: Data collected included sex, maturity, pregnancy status, number of fetuses per pregnancy, cryptorchidism, and occurrence of complications or euthanasia. RESULTS: Adult cats represented 85% of the population, and 57% were ...
Divon Michael Y - - 2002
OBJECTIVE: The purpose of this study was to evaluate the association between fetal gender and prolonged pregnancy. STUDY DESIGN: All deliveries in Sweden between 1987 and 1996 were evaluated for participation in this study. Inclusion criteria included (1) singleton pregnancy, (2) the absence of apparent congenital or chromosomal anomalies, (3) ...
Horiguchi T - - 2002
Two-month flow-through exposure experiments of tributyltin (TBT) and triphenyltin (TPhT) were conducted with abalone, Haliotis gigantea. Nominal concentrations of 100 ng TBT/l and 100 ng TPhT/l caused significant spermatogenesis in ovaries of exposed females. There were also significantly more contracted primary oocytes observed in females exposed to either TBT or ...
Morales J - - 2002
Cuentepec is a rural village of central Mexico, where 1300 pigs were bred at the time of the study in conditions that favor Taenia solium transmission. The tongues of 1087 (84%) of these pigs were visually examined and 33% were found to be cysticercotic. Castration of male pigs increased prevalence ...
Feldheim Kevin A - - 2002
Surprisingly little is known about the reproductive behaviour and breeding biology of most shark species, especially in natural populations. Here, we characterize reproductive patterns and use of a natal nursery at Bimini, Bahamas by lemon sharks, Negaprion brevirostris. We systematically and exhaustively sampled young lemon sharks at Bimini annually from ...
Evans Jennifer A - - 2002
In several mammalian species, circadian pacemakers of breeding females synchronize the developing clocks of offspring by as of yet unspecified mechanisms. The present study assessed whether maternal communication of circadian rhythms extends beyond setting pacemaker phase to include transfer of a fundamental reorganization of component circadian oscillators from dams to ...
Ohnishi Yasuyuki - - 2002
Three groups of ICR male and female mice were exposed to 50-Hz, sinusoidal, alternating, horizontal magnetic fields of 0.0 mT (sham), 0.5 mT and 5.0 mT (rms) for 9 and 2 weeks prior to mating for males and females, respectively, through fertilization and until cesarean sectioning. Fetuses were collected by ...
McAllan B M - - 2002
Antechinus stuartii is a small marsupial with a brief, highly synchronised mating period believed to be controlled by the rate of change of photoperiod. Two experiments were performed to explore aspects of photoperiodic control of the seasonal cycle. In the first experiment the pineal hormone, melatonin, administered in the drinking ...
Cho Fumiaki - - 2002
This paper reports the results of reproduction with 45 wild African green monkeys (Cercopithecus aethiops) (36 females and 9 males) during the nine years from 1981 to 1989 under indoor individually-caged conditions. In 206 cases of menstruation observed, menstrual discharge lasted for 2.5 +/- 1.2 days in cycles of 22-48 ...
Greydanus Donald E - - 2002
As the twentieth century progressed, the female athlete became an accepted participant of sports at all levels. This article reviews various aspects of female sports participation. After an historical perspective, selected comments are provided on psychologic and physiologic aspects. Concepts of adolescent gynecology are reviewed, including breast and menstrual problems ...
Garnier J N - - 2002
Female wild black rhinoceroses in Zimbabwe were monitored non-invasively using faecal progesterone metabolite analysis and observation of reproductive behaviour. A postpartum period of reproductive inactivity of at least 4 months, followed by a period of 4-7 months of oestrous cyclicity, was detected in six multiparous females. Three-quarters of the oestrous ...
Wolff Jerry O. - - 2002
We conducted a mating experiment in the laboratory using prairie voles, Microtus ochrogaster, to document that multi-male mating (MMM) can occur in this supposedly monogamous species and to test two hypotheses for the advantages of MMM in female mammals. The two hypotheses are that MMM (1) increases the probability of ...
Addo Phyllis - - 2002
The ovulatory mechanism of the grasscutter was determined in two phases. Phase one was the histological examination of ovaries of sexually mature grasscutters in various reproductive conditions (non-mated, mated, pregnant) for Corpora lutea (an indicator of ovulation). The second phase was an evaluation of the reproductive performance (female's acceptance to ...
Anolli Luigi - - 2002
The authors analyzed the suprasegmental (temporary) vocal profiles of 19 young men (not married) during their seductive interaction with 19 young women (not married) whom they had not known previously. The aim of the research was to verify the specificity, the sequential temporal stream, and the efficacy of the acoustical ...
Lourdais Olivier - - 2002
Spontaneous anorexia has been documented in various animal species and is usually associated with activities competing with food intake. In natural conditions, most female aspic vipers (Vipera aspis) stop feeding during the two months of pregnancy. We carried out a simple experiment on 40 pregnant females to determine whether anorexia ...
Mazza V - - 2002
Female pseudohermaphroditism associated with luteoma of pregnancy (LP) is a rare condition characterized by varying degrees of masculinization of a female fetus. We describe a case, diagnosed at 13 weeks gestation. Transvaginal ultrasound at 5 weeks of gestation revealed a normal intrauterine gestational sac and an enlarged maternal right ovary. ...
Wu Yuejin - - 2002
OBJECTIVE: Cardiac repolarization is prolonged and repolarization reserve (RR) is diminished in female rabbits and humans, compared to males. Reduced RR is evidenced by the relatively greater increase in ventricular action potential duration (APD) in myocytes from females in response to drugs that block repolarizing K(+) currents. Mice are an ...
Witters I - - 2002
We report a 13-week-old female fetus with early onset fetal akinesia deformation sequence (FADS) and hydranencephaly. In a previous pregnancy, the same ultrasonographic findings were noted at 13 weeks. Fetopathological examination of both female fetuses confirmed FADS with severe arthogryposis, multiple pterygia, and muscular hypoplasia. Neuropathological examination showed massive cystic ...
Duer Connie - - 2002
It has been shown in some species that fetal testes produce testosterone early in gestation. This study investigated the possibility that fetal testosterone may be reflected in maternal serum levels in the Asian elephant (Elephas maximus). Weekly serum samples were collected from seventeen pregnant captive Asian elephants and analyzed via ...
Geiger J-M - - 2002
Review of preclinical data including genotoxicity assays and a male rat reproduction toxicology study demonstrates that acitretin (Neotigason)/Soriatane) does not affect the reproductive outcome in naive females mated with treated males. Prospective studies of teratogenic risk or impairment of fertility cannot be ethically conducted in humans. However, it is highly ...
Palanza P - - 2002
There has been increasing interest, both at the scientific and regulatory level, in the use of ethological methods for evaluating neural effects of endocrine disrupters. We present a series of ethological studies on the effects of maternal exposure to low, environmentally relevant doses (0.02, 0.2, and 2 microg/g mother bw/day) ...
Jones A G - - 2001
Due to the phenomenon of male pregnancy, the fish family Syngnathidae (seahorses and pipefishes) has historically been considered an archetypal example of a group in which sexual selection should act more strongly on females than on males. However, more recent work has called into question the idea that all species ...
Walker C L - - 2001
Many factors that can modulate the risk of developing uterine leiomyoma have been identified, including parity. Epidemiological data on decreased risk of developing this disease has been subject to different interpretations regarding whether pregnancy per se is protective or, as leiomyomas are a major cause of infertility, women that develop ...
Merbs C F - - 2001
The objective of this study was to identify the presence of degenerative spondylolisthesis in adult Native American skeletons recovered from prehistoric and historic Pueblo sites in New Mexico. The vertebral columns of 491 individuals that were complete enough to allow the necessary observations produced 64 cases, with a total of ...
Dransfield R D - - 2001
An incomplete ring of electric nets was evaluated as a means of estimating trap efficiency for Glossina spp. This methodology assumes flies approach the trap directly, and then enter, or leave directly in random directions. These results showed that the ratio of the number of flies intercepted on the outside ...
Malik N M - - 2001
The ob/ob mouse has a complete absence of circulating leptin, resulting in obesity and infertility. Using the minimum daily dose of leptin required to maintain normal body weight and sexual maturation (5 mg/kg, ip), leptin-treated ob/ob females were mated with either wild-type (+/+) or leptin-treated ob/ob males. The leptin treatment ...
Latka M - - 2001
The female condom has been on the US market for over 8 years and was hailed as a method that would allow women greater control in protecting themselves against unwanted pregnancy and sexually transmitted infections. However, since its launch, promotion of the female condom has met with challenges that vary ...
Spironello Vella E - - 2001
Novel male mice can disrupt intrauterine implantation of fertilized ova in inseminated females. Evidence indicates mediation by androgen-dependent excretions. This study was designed to examine the time course of males' ability to disrupt pregnancy following castration and relate this to their urinary excretion of testosterone and 17 beta-estradiol. During days ...
Patton Z J - - 2001
Selection may act on the weakest link in fitness to change how a species adapts to an environmental stress. For many species, this limitation may be reproduction. After adult Drosophila melanogaster, Drosophila simulans, and Drosophila mojavensis males were exposed to varying levels of thermal stress well below those that endanger ...
Champagne F - - 2001
Naturally occurring variations in maternal licking/grooming influence neural development and are transmitted from mother to female offspring. We found that the induction of maternal behavior in virgin females through constant exposure to pups (pup sensitization) was significantly shorter in the offspring of High compared with Low licking/grooming mothers, suggesting differences ...
Caplan D M - - 2001
Listeria monocytogenes, an intracellular facultative germ that causes the invasion, sometimes fatal, in susceptible hosts is a food borne pathogen with ubiquitary spread that has generated a public health problem for such risk groups as: pregnant women, foetuses, new borns. 504 women with abortive disease were serologically investigated in 1999 ...
Rhind S M - - 2001
Research from a wide range of scientific disciplines has shown that the reproductive performance of animals in adult life is determined, in part, by a variety of extraneous influences acting at different stages of development from before conception until after birth. These effects are probably mediated through changes in the ...
Keisman E L - - 2001
Each Drosophila genital imaginal disc contains primordia for both male and female genitalia and analia. The sexually dimorphic development of this disc is governed by the sex-specific expression of doublesex (dsx). We present data that substantially revises our understanding of how dsx controls growth and differentiation in the genital disc. ...
deCatanzaro D - - 2001
It is well established that chemical emissions of novel males disrupt intrauterine implantation of fertilized ova in inseminated female mice, but the specific nature of these chemicals is not known. Given that novel males excrete androgens and estrogens in their urine and feces, the current experiments were designed to determine ...
Lyons E T - - 2001
A prevalence survey for hookworms (Uncinaria spp.) was done in northern fur seal (Callorhinus ursinus) and California sea lion (Zalophus californianus) pups on San Miguel Island, CA, in 2000. Intestines of dead pups were examined for adult hookworms in July. These parasites were found in 95% of 20 fur seal ...
< 4 5 6 7 8 9 10 11 12 13 14 >