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PubMed1981

Photosynthesis of Grass Species Differing in Carbon Dioxide Fixation Pathways : VII. CHROMOSOME NUMBERS, METAPHASE I CHROMOSOME BEHAVIOR, AND MODE OF REPRODUCTION OF PHOTOSYNTHETICALLY DISTINCT PANICUM SPECIES.

Panicum species of the Laxa group were investigated in a series of published reports and were found to possess C(4), C(3), and intermediate photosynthetic characteristics. Taxonomic and other relationships among these plants, however, are not clear. It was the objective of this investigation to document chromosome number, metaphase I chromosome behavior, and mode of reproduction, including abnormalities in the embryo sac, for these species.Chromosome counts showed a basic number (x) of 10 and ploidy levels of diploid (2n = 2x = 20), tetraploid (2n = 4x = 40), and hexaploid (2n = 6x = 60) in this group of Panicum. One diploid and one tetraploid accession of the C(4) species, Panicum prionitis Griseb., were obtained. Of the intermediate species, Panicum milioides Nees ex Trin. was diploid, Panicum schenckii Hack. was hexaploid, and Panicum decipiens Nees, ex Trin. was found to possess two ploidy levels, one accession being diploid and the other accession being hexaploid. All the C(3) species, which included two accessions of Panicum laxum Sw., three accessions of Panicum hylaeicum Mez., and one accession of Panicum rivulare Trin., were tetraploid.Meiosis was regular with primarily bivalent pairing at metaphase I in all species except the tetraploid accession of P. prionitis which possessed from 4 to 10 tetravalents. Stainable pollen was high in all species, ranging from 70 to 99%. Embryo sac analyses showed a single sac in all plants except the tetraploid accession of P. prionitis, which was found to possess an additional sac at anthesis. An additional sac was also observed in some ovaries of the P. schenckii accession. Self-pollinated seed set was high in all accessions except the diploid accession of P. prionitis and one accession of P. laxum where no seed was set under bagged conditions.This information establishes, within the limits of this collection, a base for future studies on genetic, taxonomic, photosynthetic, and evolutionary relationships among these plants. Possession of the same basic chromosome number, regular meiotic pairing, a high degree of stainable pollen, and good seed set in most of the plants studied indicate possible success in making hybrids for a genetic study of photosynthetic pathways in Panicum.

Journal Article↗
PubMedDate not supplied

Bound and gagged: America's family planning network.

During the past decade, the number of family planning clinics receiving support from the federal government has fallen from 5,000 to 4,000 despite a growing demand for their services among poor women and teenagers. At the same time, family planning providers have been under regulatory attack, forced to fend off a "squeal rule" aimed at teenagers and to stop a "gag rule" preventing abortion referral. With the climate in Washington unlikely to change, family planners should consider integrating other services into their network or press to include family planning in other care networks. A new national commission could help break the logjam on federal legislation.

Abortion, Legal↗
PubMed1991

[Adolescents].

Explore the source record for details and available documents.

Adolescent↗
PubMed1998

Husbands' reproductive health knowledge, attitudes, and behavior in Uttar Pradesh, India.

To enhance the reproductive health status of couples in developing countries, the knowledge, attitudes, and behavior of both women and men must be investigated, especially where women depend on men for the decision to seek care. This study analyzes data from a survey of 6,727 husbands from five districts in the northern state of Uttar Pradesh, India. Data are presented on men's knowledge of women's health and on their own sexual behavior outside the context of marriage, on their perceptions of sexual morbidity and their attempts at treatment for specific conditions, and on their opinions concerning the social role of wives. Findings indicate that men know little about maternal morbidity or sexual morbidity conditions. Few husbands reported that they had had sexual experience outside of marriage and the majority of these few said they had had such a relationship with more than one partner. Of men who said they had had reproductive morbidity symptoms, many said they had not sought treatment. Men's views concerning the role of wives indicate a low level of women's autonomy in this region of India. Results indicate a pressing need for reproductive health education that targets both women and men in Uttar Pradesh.

Adolescent↗
PubMed2000

Brain biogenic amines and reproductive dominance in bumble bees (Bombus terrestris).

To begin to explore the role of biogenic amines in reproductive division of labor in social insects, brain levels of dopamine, serotonin, and octopamine were measured in bumble bee (Bombus terrestris) workers and queens that differ in behavioral and reproductive state. Levels of all three amines were similar for mated and virgin queens. Young workers that developed with or without a queen had similar amine levels, but in queenright colonies differences in biogenic amine levels were associated with differences in behavior and reproductive physiology. Dominant workers had significantly higher octopamine levels compared with workers of lower dominance status but of similar size, age, and ovary state. High dopamine levels were associated with the last stages of oocyte development irrespective of worker social status and behavior. These results suggest that biogenic amines are involved in behavioral and physiological aspects of regulation of reproduction in bumble bees.

Animals↗
PubMed2002

Ram mating behavior after long-term selection for reproductive rate in Rambouillet ewes.

Mating behavior is known to be heritable in several species, but it is not known if selection schemes for ewe reproductive traits affect mating behavior of rams. Therefore, our objectives were to determine if divergent (high vs low index) selection of a female reproductive trait (lambs born divided by age of ewe minus one) affects mating behavior patterns of male offspring during training to service an artificial vagina (AV) in a less than natural setting (Exp. 1) or during serving capacity tests (SCT) in simulated natural mating conditions (Exp. 2). The method for evaluating male mating behavior was a series of serving capacity tests to estimate sexual performance. For Exp. 1, five, 30-min observations were conducted to assess the mating behavior of 29 rams (22 mo old) being trained to service an AV. In Exp. 1, percentages of rams mounting (73 vs 36%) and ejaculating (67 vs 29%) differed (P < 0.05) between rams from high and low Rambouillet ewe selection lines, respectively. In Exp. 2, ram classification consisted of exposing each 22- to 24-mo-old ram (n = 48) to three unrestrained ewes in estrus for 18, 30-min tests. Any ram that had not mounted or ejaculated during SCT was evaluated for sexual orientation in a 30-min preference test in which each ram had access to both restrained estrual ewes and restrained rams. In Exp. 2, there was no difference (P > 0.2) in percentages of rams mounting (92 vs 78%) and ejaculating (88 vs 74%) between rams from high and low Rambouillet ewe selection lines, respectively. There was no difference (P > 0.33) between high and low ewe selection line rams for mounts or ejaculations for 18 SCT. Only one male-oriented ram was identified, which was from the high line. In Exp. 2, six SCT were necessary to obtain 95% reliability in sexual performance scores. Results of these studies indicate that long-term selection of ewes for litter size did not alter ram sexual performance after SCT under simulated natural mating conditions or affect incidence of male-oriented rams. Mating behavior observed during training to service an AV was lower for rams from ewes of the low selection line than for rams from ewes of the high selection line. We concluded that long-term selection for reproductive rate in ewes did not alter mating behavior patterns of male offspring; however, test conditions, such as restrained and unrestrained ewes and number of serving capacity tests, may affect conclusions in studies that evaluate sexual performance of rams.

Animals↗
PubMed2005

Current research in amphibians: studies integrating endocrinology, behavior, and neurobiology.

Amphibian behavioral endocrinology has focused on reproductive social behavior and communication in frogs and newts. Androgens and estrogens are critical for the expression of male and female behavior, respectively, and their effects are relatively clear. Corticosteroids have significant modulatory effects on the behavior of both sexes, as does the peptide neuromodulator arginine vasotocin in males, but their effects and interactions with gonadal steroids are often complex and difficult to understand. Recent work has shown that the gonadal hormones and social behavior are mutually reinforcing: engaging in social interactions increases hormone levels just as increasing hormone levels change behavior. The reciprocal interactions of hormones and behavior, as well as the complex interactions among gonadal steroids, adrenal steroids, and peptide hormones have implications for the maintenance and evolution of natural social behavior, and suggest that a deeper understanding of both endocrine mechanisms and social behavior would arise from field studies or other approaches that combine behavioral endocrinology with behavioral ecology.

Adrenal Cortex Hormones↗
PubMed2003

Molecular genetic approaches to the study of primate behavior, social organization, and reproduction.

In the past several decades, the development of novel molecular techniques and the advent of noninvasive DNA sampling, coupled with the ease and speed with which molecular analyses can now be performed, have made it possible for primatologists to directly examine the fitness effects of individual behavior and to explore how variation in behavior and social systems influences primate population genetic structure. This review describes the theoretical connections between individual behavior and primate social systems on the one hand and population genetic structure on the other, discusses the kinds of molecular markers typically employed in genetic studies of primates, and summarizes what primatologists have learned from molecular studies over the past few decades about dispersal patterns, mating systems, reproductive strategies, and the influence of kinship on social behavior. Several important conclusions can be drawn from this overview. First, genetic data confirm that, in many species, male dominance rank and fitness are positively related, at least over the short term, though this relationship need not simply be a reflection of male-male contest competition over mates. More importantly, genetic research reveals the significance of female choice in determining male reproductive success, and documents the efficacy of alternative mating tactics among males. Second, genetic data suggest that the presumed importance of kinship in structuring primate social relationships needs to be evaluated further, at least for some taxa such as chimpanzees in which demographic factors may be more important than relatedness. I conclude this paper by offering several suggestions of additional ways in which molecular techniques might be employed in behavioral and ecological studies of primates (e.g., for conducting "molecular censuses" of unhabituated populations, for studying disease and host-parasite interactions, or for tracking seed fate in studies of seed dispersal) and by providing a brief introduction to the burgeoning field of nonhuman primate behavioral genetics.

Animals↗
PubMedDate not supplied

Effects of prenatal diphenylhydantoin treatment on reproductive outcome, development, and behavior in rats.

Pregnant Sprague-Dawley rats were administered sodium diphenylhydantoin (DPH) by gavage on gestation days 9-18 in doses of 0, 100, or 200 mg/kg. DPH-treated dams showed a dose-related decrease in weight gain throughout the drug treatment period. Offspring had significantly lowered birth weights, along with increased mortality through the first 30 days of life. In one of the experiments specifically designed to measure pup mortality, the rates were 41.4% and 60.7% respectively, for the 100 and 200 mg/kg DPH groups. Shortly after eye opening, many of the DPH-treated animals developed chromodacryorrhea, a condition that remained throughout the experiment. Aside from lowered body weights, no differences were observed in the attainment of several standard developmental landmarks. During the neonatal period, the pups exposed in utero to 100 mg/kg DPH showed a significant increase in pivoting locomotion on postnatal days 7 and 9. As adults, the animals exposed to 200 mg/kg DPH showed significant increases in locomotor activity measures. Both DPH groups developed a dose-related and highly abnormal spontaneous circling behavior. These results confirm a small but growing body of literature that demonstrates that DPH is a behavioral teratogen.

Administration, Oral↗
PubMed1977

[Use of disulfiram in a histochemical study of the influence of different stimuli on the concentration of noradrenaline in brain structures].

With the help of the histochemical fluorescence method the changes in noradrenaline fluorescence of nuc. septi lateralis, nuc. interstitialis striae terminalis and nuc. preoticus medialis during conditioning and unconditioned stimulation were studied. In 135 disulfiram pretreated rats the depletion of noradrenaline fluorescence in the investigated structures was found after electro-stimulation of feet during 5 min., 1 and 2 hours, open-field behavior and reproduction of a conditioned avoidance response. Twelve hours after disulphiram administration the suppression of the open-field behavior and reproduction of the conditioned avoidance response as well as the depletion of noradrenaline fluorescence in the investigated structures were detected.

Animals↗
PubMed1993

Sexuality: sexual activity and contraception during adolescence.

Adolescent sexual activity is increasing. Premature sexual intercourse results in high figures of adolescent pregnancy and abortion, as well as in increased risk of sexually transmitted diseases (STDs). Lack of information on the prevention of STDs and poor hygiene in both boys and girls are also main reasons for increased morbidity because of STDs during adolescence. Contraceptive behaviour during adolescence varies between countries and communities. It seems, however, that the condom and oral contraceptives (OC) are popular contraceptive methods. Ineffective methods such as periodic abstinence, coitus interruptus, and withdrawal before ejaculation are in use. On the other hand, compliance of adolescents on contraception is poor. The above are additional causes for increasing rates of adolescent pregnancies. Countries providing sexual education programs in schools present lower rates of pregnancy and abortion. Adolescent pregnancy is safe if a careful follow up is accepted by the teenager. A significant number of homeless youth are homosexuals or lesbian adolescents. Most of them are at high risk for HIV infection, AIDS, and STDs. It is concluded that sexual education programs are absolutely necessary to offer adolescents the knowledge on the complications of premature sexual activity, as well as prevention of the undesired pregnancy and STDs.

Adolescent↗
PubMed1997

Adolescent sexuality: an educational and counseling challenge.

A review of family-planning literature reveals that researchers adopt narrow definitions of sexual behavior and focus almost exclusively on risks of pregnancy and diseases. Little concern is shown in these articles about promoting the idea of more communicative, pleasurable, and egalitarian sexual relations among teenagers, because the focus is on avoiding behaviors that are defined as "high risk." In the United States, there is little evidence that these contraceptive-based sex education programs have resulted in reduced sexual activity, diminished teenage-pregnancy rates, or increased effective contraceptive use. In Canada the clinical evidence is that existing prevention strategies are not working. In Sweden the increasing rates of STDs and teenage pregnancies in the late 1980s worried authorities. The figures were brought down in the 1990s by extensive efforts both in schools and at publicly funded adolescent health clinics and family-planning units. It has been shown that girls with good self-esteem and a sense of responsibility avoided pregnancies and STDs in follow-up studies. Girls with a high degree of risk-prone behavior or attitudes and girls with a problematic life situation and without adequate family support were those who became unintentionally pregnant and/or acquired an STD. Countries where sex education has been accepted, combined with widely spread family-planning services and abortion on demand, have the lowest pregnancy and abortion rates in the world. But even they could do better by putting sex education in its proper place in society and by using both old and new methods.

Adolescent↗