WorldWideScience

Sample records for two-generation reproductive study

  1. Rat two-generation reproductive toxicity study of bisphenol A.

    Science.gov (United States)

    Ema, M; Fujii, S; Furukawa, M; Kiguchi, M; Ikka, T; Harazono, A

    2001-01-01

    This study was conducted to determine the low-dose effects of bisphenol A (BPA) in a rat two-generation reproduction study. Groups of 25 male and 25 female Crj: CD (SD) IGS rats were given BPA at 0.2, 2, 20, or 200 microg/kg/day by gastric intubation throughout the study beginning at the onset of a 10- and 2-week premating period, in F0 males and females, respectively, and continuing through the mating, gestation, and lactation periods, for two generations. There were adult (F0, F1, F2) and postnatal day (PND) 22 (F1, F2) necropsies: the oldest F2 males and females being killed at postnatal weeks 7 and 14, respectively. No compound-related clinical signs or effects on body weight or food consumption were observed in any generation. There were no compound-related changes in surface righting reflex, negative geotaxis reflex, mid-air righting reflex, pinna detachment, incisor eruption, eye opening, testes descent, preputial separation, or vaginal opening in F1 and F2 generations, or behavior in the open field or water filled multiple T-maze in the F1 generation. No test compound-related changes in estrous cyclicity, copulation index, fertility index, number of implantations, gestation length, litter size, pup weight, pup sex ratio, pup viability, or other functional reproductive measures were noted in any generation. A few significant changes in the anogenital distance (AGD) per cube root of body weight ratio were found at 0.2 and 20 microg/kg in F1 males, at 2, 20, and 200 microg/kg in F1 females, and at 20 and 200 microg/kg in F2 females. However, the changes in the AGD were consistently small (within 5% of control values), and no continuous changes in the AGD or AGD/cube root of body weight ratio were detected. There were no compound-related changes in epididymal sperm counts or motility in F0 and F1 males. No compound-related necropsy findings or effects on organ weight including the reproductive organs were found in any generation. Histopathologic examinations

  2. Sensitive endpoints in extended one-generation reproductive toxicity study versus two generation?

    DEFF Research Database (Denmark)

    Christiansen, Sofie

    . The protocol includes assessment of novel endpoints of concern and developmental landmarks such as anogenital distance, nipple retention (both sensitive endpoints for anti-androgenic effects in male offspring) and mammary gland development (sensitive endpoint for oestrogen action) and may also include...... during critical period of development in contrast to the parental generation. Retrospective analysis of available two-generation studies, however, indicate that the assessment included in the study of other endpoints in the male offspring such as histopathology of reproductive organs and semen quality...

  3. Two-generation reproductive toxicity study of tributyltin chloride in female rats.

    Science.gov (United States)

    Ogata, R; Omura, M; Shimasaki, Y; Kubo, K; Oshima, Y; Aou, S; Inoue, N

    2001-05-25

    A two-generation reproductive toxicity study of the effects of tributyltin chloride (TBTCl) was conducted in female rats using dietary concentrations of 5, 25, and 125 ppm TBTCl. Reproductive outcomes of dams (number and body weight of pups and the percentage of live pups) and the growth of female pups (the day of eye opening and body weight gain) were significantly decreased in the 125 ppm TBTCl group. A delay in vaginal opening and impaired estrous cyclicity were also observed in the 125 ppm TBTCl group. However, an increase in anogenital distance was found in all TBTCl groups on postnatal d 1. A dose-effect relationship was observed in TBTCl-induced changes in anogenital distance. These results indicate that the whole-life exposure to TBTCl affects the sexual development and reproductive function of female rats. In addition, the TBTCl-induced increase in anogenital distance seems to suggest it may exert a masculinizing effect on female neonates. However, the concentrations of TBTCl used in this study are not environmentally relevant.

  4. Male reproductive system parameters in a two-generation reproduction study of ammonium perfluorooctanoate in rats and human relevance.

    Science.gov (United States)

    York, Raymond G; Kennedy, Gerald L; Olsen, Geary W; Butenhoff, John L

    2010-04-30

    Ammonium perfluorooctanoate (ammonium PFOA) is an industrial surfactant that has been used primarily as a processing aid in the manufacture of fluoropolymers. The environmental and metabolic stability of PFOA together with its presence in human blood and long elimination half-life have led to extensive toxicological studies in laboratory animals. Two recent publications based on observations from the Danish general population have reported: (1) a negative association between serum concentrations of PFOA in young adult males and their sperm counts and (2) a positive association among women with time to pregnancy. A two-generation reproduction study in rats was previously published (2004) in which no effects on functional reproduction were observed at doses up to 30mg ammonium PFOA/kg body weight. The article contained the simple statement: "In males, fertility was normal as were all sperm parameters". In order to place the recent human epidemiological data in perspective, herein we provide the detailed male reproductive parameters from that study, including sperm quality and testicular histopathology. Sperm parameters in rats from the two-generation study in all ammonium PFOA treatment groups were unaffected by treatment with ammonium PFOA. These observations reflected the normal fertility observations in these males. No evidence of altered testicular and sperm structure and function was observed in ammonium PFOA-treated rats whose mean group serum PFOA concentrations ranged up to approximately 50,000ng/mL. Given that median serum PFOA in the Danish cohorts was approximately 5ng/mL, it seems unlikely that concentrations observed in the general population, including those recently reported in Danish general population, could be associated causally with a real decrement in sperm number and quality.

  5. Toxicology Studies on Lewisite and Sulfur Mustard Agents: Two-Generation Reproduction Study of Lewisite in Rats Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sasser, L. B.; Cushing, J. A.; Kalkwarf, D. R.; Mellick, P. W.; Buschbom, R. L.

    1989-07-15

    Occupational health standards have not been established for Lewisite [bis(2-chlorethyl)arsine], a potent toxic vesicant which reacts with the sulfhydryl groups of proteins through its arsenic group. The purposes of this study were to determine the reproductive consequences and dose~response of continuing Lewisite exposure of parental males and females and their offspring in a 42-week two-generation study. Solutions of Lewisite were prepared for administration by diluting the neat agent with sesame oil. Rats were administered Lewisite (0, 0.10, 0.25 or 0.60 mg/kg/day for 5 days a week) via intragastric intubation prior to mating, during mating and after mating until the birth of their offspring. The dams continued to receive Lewisite during lactation. At weaning, male and female offspring of each group were selected to continue on the study; rece1v1ng Lewisite during adolescence, mating and throughout gestation. Again, the dams continued to receive Lewisite until weaning of the offspring. Lewisite had no adverse effect on reproduction performance, fertility or reproductive organ weights of male or female rats through two consecutive generations. No adverse effect to offspring were attributed to Lewisite exposure. Minor changes in growth was the only maternal effect observed. Lewisite exposure of parental rats caused no gross or microscopic lesions in testes, epididymis, prostrate, seminal vesicles, ovaries, uterus or vagina. Severe inflammation of the lung was observed at necropsy in cases in which Lewisite gained access to the respiratory system from accidental dosing or reflux and aspiration; this usually caused early death of the animal. The NOEL for reproductive effects in this study was greater than 0.60 mg/kg/day.

  6. A two-generation inhalation reproductive toxicity study upon the exposure to manganese chloride.

    Science.gov (United States)

    McGough, Doreen; Jardine, Lynne

    2017-01-01

    A number of published studies have suggested that high levels of exposure to manganese, especially those found in occupational settings, can adversely affect the reproductive system. The objective of this study was therefore to investigate if these findings can be replicated using the Sprague Dawley rat and, if so, to identify those parts of the reproductive system are more susceptible. Male and female rats were exposed to manganese dichloride (MnCl 2 ) via inhalation at concentrations of 0 (air-control); 5, 10 and 20μg/L air over 10 weeks (F0) and over 11 weeks (F1) prior to mating, and then throughout mating, gestation and lactation until termination after the F1 and F2 generation had reached Day 21 of lactation respectively. Animals were monitored for clinical signs of toxicity and for effects on body weight, food consumption, effects on the entire reproductive system including maternal care. The offspring were monitored for survival and growth up to weaning. Blood samples were taken from all adult animals for bioanalytical of manganese analysis prior to dosing, prior to mating and prior to weaning/necropsy. There were no deaths related to treatment, though respiratory tract effects were observed in F0 animals in the mid and high dose animals. Body weight and food consumption were affected at high dose in both generation. There were no treatment-related effects on the oestrous cycles, mating performance, sexual maturity, fertility or duration of gestation or litter size, the sperm motility, count of morphology (sperm) or the ovary follicle scoring in either generation. The No Observed Effect Level (NOEL) for reproductive performance was considered to be the target dose level of 20μg/L. Based on these findings, manganese chloride could not be considered a reprotoxicant under these conditions of exposure. Therefore, soluble and insoluble forms of inorganic manganese compounds by extrapolation cannot be considered as reprotoxicants. Copyright © 2016 Elsevier B

  7. Effects of triphenyltin on reproduction in Japanese medaka (Oryzias latipes) across two generations.

    Science.gov (United States)

    Horie, Yoshifumi; Watanabe, Haruna; Takanobu, Hitomi; Shigemoto, Yoshiko; Yamagishi, Takahiro; Iguchi, Taisen; Tatarazako, Norihisa

    2017-11-01

    Triphenyltin (TPT) is an organotin compound used in marine anti-fouling coatings to prevent the attachment and growth of marine organisms, and it has negative effects on aquatic organisms. TPT is still detected at low concentrations, although its use has been prohibited at least in the European Community and is restricted in Japan as well. Studies using Japanese medaka (Oryzias latipes) indicate that TPT has the potential to inhibit reproduction. Although TPT is detected in many aquatic ecosystems, the multi-generational impact of TPT remains unknown. We investigated the two-generational effects of TPT on Japanese medaka and examined the relationships of several such effects between the F0 and F1 generations. Suppression of fecundity was observed in both generations, and fertility and growth were inhibited in the F1 generation. Moreover, delayed hatching and lower hatchability were observed in F1 embryos. Importantly, the value of the lowest observed effect concentration (LOEC) for these influences in F1 was lower than that in F0: that is, the LOEC values of fecundity and mortality were 3.2μg/L in the F0 generation and 1.0μg/L in the F1 generation. Fertility was not affected by TPT in F0, whereas it was significantly suppressed in the 1.0μg/L-exposure group of the F1 generation. Our results provide the first evidence of the effects of TPT on reproduction in a teleost fish across two generations, highlighting the concern that TPT could affect reproduction and mortality at decreasing concentrations in temporally overlapping generations. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Two-generation reproductive toxicity study of implanted depleted uranium (DU) in CD rats.

    Science.gov (United States)

    Arfsten, D P; Still, K R; Wilfong, E R; Johnson, E W; McInturf, S M; Eggers, J S; Schaeffer, D J; Bekkedal, M Y-V

    2009-01-01

    Depleted uranium (DU) munitions and armor plating have been used in several conflicts over the last 17 yr, including the Persian Gulf War and the Iraq War. Because of its effectiveness and availability, DU will continue to be used in military applications into the foreseeable future. There is much controversy over the use of DU in weapons and equipment because of its potential radiological and toxic hazards, and there is concern over the chronic adverse health effects of embedded DU shrapnel in war veterans and bystanders. This study evaluated the effects of long-term implantation of DU on the reproductive success of F0 generation adults and development and survival of subsequent F1 and F2 generations in a two-generation reproductive toxicity study. F0 generation Sprague-Dawley rats, 8 wk of age, were surgically implanted with 0, 4, 8, 12, or 20 DU pellets (1 x 2 mm). Inert implant control animals were implanted with 12 or 20 tantallum (Ta) pellets. The F0 generation was then mated at 120 d post DU implantation. In the F0 generation, when measured on postimplantation d 27 and 117, uranium was present in the urine of DU-implanted animals in a dose-dependent manner. F0 reproductive success was similar across treatment groups and the maternal retrieval test revealed no changes in maternal behavior. DU implantation exerted no effect on the survival, health, or well-being of the F0 generation. Necropsy results of F0 animals were negative with the exception of a marked inflammatory response surrounding the implanted DU pellets. For the F1 generation, measures of F1 development through postnatal day (PND) 20 were unremarkable and no gross abnormalities were observed in F1 offspring. No uranium was detected in whole-body homogenates of PND 4 or PND 20 pups. Necropsy findings of F1 PND 20 pups were negative and no instances of ribcage malformation were observed in F1 PND 20 pups. Body weight and body weight gain of F1 rats through PND 120 were similar across treatment

  9. On the impact of second generation mating and offspring in multi-generation reproductive toxicity studies on classification and labelling of substances in Europe

    DEFF Research Database (Denmark)

    Rorije, Emiel; Muller, André; Beekhuijzen, Manon E.W.

    2011-01-01

    The possible impact on classification and labelling decisions of effects observed in second generation parental (P1) and offspring (F2) parameters in multi-generation studies was investigated. This was done for 50 substances classified as reproductive toxicants in Europe, for which a multi-genera...... and reduced animal use, provide strong further support for replacement of the classical two-generation reproductive toxicity study by the EOGRTS in regulatory reproductive toxicity assessment....

  10. Effect of local x-irradiation on mice reproduction in two successive generations

    International Nuclear Information System (INIS)

    Strel'nikova, N.K.; Lisenkova, L.N.

    1978-01-01

    For an experimental assessment of the biologic effectiveness of a single exposure to local irradiation exposure in simulating the conditions of exposure in X ray studies, an experiment was carried out on white mice. Mice of two successive generations were exposed to local X irradiation in the eye region. The radiation was found to bring about changes in the reproductive function (such as sterility, reduced litter size and fertility of females); these changes being dose-dependent in a nonlinear manner. The biologic effect of irradiation was greater in the second-generation mice

  11. Three-generation reproduction toxicity study of genetically modified rice with insect resistant genes.

    Science.gov (United States)

    Hu, Yichun; Zhuo, Qin; Gong, Zhaolong; Piao, Jianhua; Yang, Xiaoguang

    2017-01-01

    In the present work, we evaluated the three generation reproductive toxicity of the genetically modified rice with insectresistant cry1Ac and sck genes. 120 Sprague-Dawley (SD) rats were divided into three groups which were fed with genetically modified rice diet (GM group), parental control rice diet (PR group) and AIN-93 control diet (both used as negative control) respectively. Bodyweight, food consumption, reproductive data, hematological parameters, serum chemistry, relative organ weights and histopathology for each generation were examined respectively. All the hematology and serum chemistry parameters, organ/body weight indicators were within the normal range or no change to the adverse direction was observed, although several differences in hematology and serum chemistry parameters (WBC, BUN, LDH of male rat, PLT, PCT, MPV of female rats), reproductive data (rate of morphologically abnormal sperm) were observed between GM rice group and two control groups. No macroscopic or histological adverse effects were found or considered as treatment-related, either. Overall, the three generation study of genetically modified rice with cry1Ac and sck genes at a high level showed no unintended adverse effects on rats's reproductive system. Copyright © 2016. Published by Elsevier Ltd.

  12. Transgenerational plasticity of reproduction depends on rate of warming across generations.

    Science.gov (United States)

    Donelson, Jennifer M; Wong, Marian; Booth, David J; Munday, Philip L

    2016-10-01

    Predicting the impacts of climate change to biological systems requires an understanding of the ability for species to acclimate to the projected environmental change through phenotypic plasticity. Determining the effects of higher temperatures on individual performance is made more complex by the potential for environmental conditions experienced in previous and current generations to independently affect phenotypic responses to high temperatures. We used a model coral reef fish ( Acanthochromis polyacanthus ) to investigate the influence of thermal conditions experienced by two generations on reproductive output and the quality of offspring produced by adults. We found that more gradual warming over two generations, +1.5°C in the first generation and then +3.0°C in the second generation, resulted in greater plasticity of reproductive attributes, compared to fish that experienced the same increase in one generation. Reproduction ceased at the projected future summer temperature (31.5°C) when fish experienced +3.0°C for two generations. Additionally, we found that transgenerational plasticity to +1.5°C induced full restoration of thermally affected reproductive and offspring attributes, which was not possible with developmental plasticity alone. Our results suggest that transgenerational effects differ depending on the absolute thermal change and in which life stage the thermal change is experienced.

  13. One-generation reproductive toxicity study of DHA-rich oil in rats

    NARCIS (Netherlands)

    Blum, R.; Kiy, T.; Waalkens-Berendsen, I.; Wong, A.W.; Roberts, A.

    2007-01-01

    Polyunsaturated fatty acids, including docosahexaenoic acid (DHA), are natural constituents of the human diet. DHA-algal oil is produced through the use of the marine protist, Ulkenia sp. The reproductive toxicity of DHA-algal oil was assessed in a one-generation study. Rats were provided diets

  14. Reproductive gene expression in a coral reef fish exposed to increasing temperature across generations

    KAUST Repository

    Veilleux, Heather D; Donelson, Jennifer M; Munday, Philip L

    2017-01-01

    Reproduction in marine fish is generally tightly linked with water temperature. Consequently, when adults are exposed to projected future ocean temperatures, reproductive output of many species declines precipitously. Recent research has shown that in the common reef fish, Acanthochromis polyacanthus, step-wise exposure to higher temperatures over two generations (parents: +1.5°C, offspring: +3.0°C) can improve reproductive output in the F2 generation compared to F2 fish that have experienced the same high temperatures over two generations (F1 parents: +3.0°C, F2 offspring: +3.0°C). To investigate how a step-wise increase in temperature between generations improved reproductive capacity, we tested the expression of well-known teleost reproductive genes in the brain and gonads of F2 fish using quantitative reverse transcription PCR and compared it among control (+0.0°C for two generations), developmental (+3.0°C in second generation only), step (+1.5°C in first generation and +3.0°C in second generation), and transgenerational (+3.0°C for two generations) treatments. We found that levels of gonadotropin receptor gene expression (Fshr and Lhcgr) in the testes were reduced in developmental and transgenerational temperature treatments, but were similar to control levels in the step treatment. This suggests Fshr and Lhcgr may be involved in regulating male reproductive capacity in A. polyacanthus. In addition, lower Fshb expression in the brain of females in all temperature treatments compared to control, suggests that Fshb expression, which is involved in vitellogenesis, is sensitive to high temperatures. Our results help elucidate key genes that facilitate successful reproduction in reef fishes when they experience a gradual increase in temperature across generations consistent with the trajectory of climate change.

  15. Reproductive gene expression in a coral reef fish exposed to increasing temperature across generations.

    Science.gov (United States)

    Veilleux, Heather D; Donelson, Jennifer M; Munday, Philip L

    2018-01-01

    Reproduction in marine fish is generally tightly linked with water temperature. Consequently, when adults are exposed to projected future ocean temperatures, reproductive output of many species declines precipitously. Recent research has shown that in the common reef fish, Acanthochromis polyacanthus , step-wise exposure to higher temperatures over two generations (parents: +1.5°C, offspring: +3.0°C) can improve reproductive output in the F2 generation compared to F2 fish that have experienced the same high temperatures over two generations (F1 parents: +3.0°C, F2 offspring: +3.0°C). To investigate how a step-wise increase in temperature between generations improved reproductive capacity, we tested the expression of well-known teleost reproductive genes in the brain and gonads of F2 fish using quantitative reverse transcription PCR and compared it among control (+0.0°C for two generations), developmental (+3.0°C in second generation only), step (+1.5°C in first generation and +3.0°C in second generation), and transgenerational (+3.0°C for two generations) treatments. We found that levels of gonadotropin receptor gene expression ( Fshr and Lhcgr ) in the testes were reduced in developmental and transgenerational temperature treatments, but were similar to control levels in the step treatment. This suggests Fshr and Lhcgr may be involved in regulating male reproductive capacity in A. polyacanthus . In addition, lower Fshb expression in the brain of females in all temperature treatments compared to control, suggests that Fshb expression, which is involved in vitellogenesis, is sensitive to high temperatures. Our results help elucidate key genes that facilitate successful reproduction in reef fishes when they experience a gradual increase in temperature across generations consistent with the trajectory of climate change.

  16. Reproductive gene expression in a coral reef fish exposed to increasing temperature across generations

    KAUST Repository

    Veilleux, Heather D

    2017-12-07

    Reproduction in marine fish is generally tightly linked with water temperature. Consequently, when adults are exposed to projected future ocean temperatures, reproductive output of many species declines precipitously. Recent research has shown that in the common reef fish, Acanthochromis polyacanthus, step-wise exposure to higher temperatures over two generations (parents: +1.5°C, offspring: +3.0°C) can improve reproductive output in the F2 generation compared to F2 fish that have experienced the same high temperatures over two generations (F1 parents: +3.0°C, F2 offspring: +3.0°C). To investigate how a step-wise increase in temperature between generations improved reproductive capacity, we tested the expression of well-known teleost reproductive genes in the brain and gonads of F2 fish using quantitative reverse transcription PCR and compared it among control (+0.0°C for two generations), developmental (+3.0°C in second generation only), step (+1.5°C in first generation and +3.0°C in second generation), and transgenerational (+3.0°C for two generations) treatments. We found that levels of gonadotropin receptor gene expression (Fshr and Lhcgr) in the testes were reduced in developmental and transgenerational temperature treatments, but were similar to control levels in the step treatment. This suggests Fshr and Lhcgr may be involved in regulating male reproductive capacity in A. polyacanthus. In addition, lower Fshb expression in the brain of females in all temperature treatments compared to control, suggests that Fshb expression, which is involved in vitellogenesis, is sensitive to high temperatures. Our results help elucidate key genes that facilitate successful reproduction in reef fishes when they experience a gradual increase in temperature across generations consistent with the trajectory of climate change.

  17. Acute, reproductive toxicity and two-generation teratology studies of a standardized quassinoid-rich extract of Eurycoma longifolia Jack in Sprague-Dawley rats.

    Science.gov (United States)

    Low, Bin-Seng; Das, Prashanta Kumar; Chan, Kit-Lam

    2014-07-01

    The roots of Eurycoma longifolia Jack are popularly sought as herbal medicinal supplements to improve libido and general health amongst the local ethnic population. The major quassinoids of E. longifolia improved spermatogenesis and fertility but toxicity studies have not been well documented. The reproductive toxicity, two generation of foetus teratology and the up-and-down acute toxicity were investigated in Sprague-Dawley rats orally treated with quassinoid-rich E. longifolia extract (TAF273). The results showed that the median lethal dose (LD50 ) of TAF273 for female and male rats was 1293 and >2000 mg/kg, respectively. Fertility index and litter size of the TAF273 treated were significantly increased when compared with those of the non-treated animals. The TAF273-treated dams decreased in percentage of pre-implantation loss, post-implantation loss and late resorption. No toxic symptoms were observed on the TAF273-treated pregnant female rats and their foetuses were normal. The no-observed adverse effect level (NOAEL) obtained from reproductive toxicity and teratology studies of TAF273 in rats was 100 mg/kg body weight/day, being more than 10-fold lower than the LD50 value. Thus, any human dose derived from converting the rat doses of 100 mg/kg and below may be considered as safe for further clinical studies. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Evaluation of a two-generation reproduction toxicity study adding endpoints to detect endocrine disrupting activity using vinclozolin.

    Science.gov (United States)

    Matsuura, Ikuo; Saitoh, Tetsuji; Ashina, Michiko; Wako, Yumi; Iwata, Hiroshi; Toyota, Naoto; Ishizuka, Yoshihito; Namiki, Masato; Hoshino, Nobuhito; Tsuchitani, Minoru

    2005-12-01

    A two-generation reproduction toxicity study in rats adding extra endpoints to detect endocrine disrupting activity was conducted using vinclozolin by dietary administration at 0, 40, 200, and 1000 ppm, for investigation of its utility. The extra endpoints included anogenital distance (AGD), nipple development, sexual maturation (vaginal opening and preputial separation), estrous cycle, spermatogenesis, sex organ weights, and blood hormone concentrations (thyroid and sex hormones). Hepatic drug-metabolizing enzyme activities were also measured. The results revealed changes due to vinclozolin in the AGD, nipple development, sexual maturation, sex organ weights, and blood sex hormone concentrations in males of both parental animals and offspring, even at the lowest dose of 40 ppm, confirmed by results for the classical endpoints of histopathological examination at 200 ppm and mating at 1000 ppm. The effects on parental males included increased pituitary and testis weights, and decreased epididymis weights at 1000 ppm in both generations, and decreased prostate and epididymis weights at 200 and 1000 ppm and seminal vesicle weights at 1000 ppm in F1 males. Histopathological examination revealed hypertrophy of the basophilic cells in the pituitary at these two doses, and diffuse hyperplasia of the testicular interstitial cells and atrophy of the seminal vesicle mucosa at 1000 ppm in F0 and F1 males. In addition, F1 males demonstrated decrease in prostate fluid at 200 and 1000 ppm. Blood hormone analysis revealed increases in LH, FSH, testosterone, and DHT in F0 and F1 males at 1000 ppm. General toxicological effects included suppressed body weight gain in F0 and F1 females and in F1 males, and reduced food consumption in F0 and F1 females at 1000 ppm. Histopathological examination revealed centrilobular hepatocellular hypertrophy in males at 200 and 1000 ppm and in females at 1000 ppm, increased lipid droplets in the adrenal zona fasciculata and zona glomerulosa in

  19. Oral two-generation reproduction toxicity study with NM-200 synthetic amorphous silica in Wistar rats

    NARCIS (Netherlands)

    Wolterbeek, A.; Oosterwijk, T.; Schneider, S.; Landsiedel, R.; Groot, D. de; Ee, R. van; Wouters, M.; Sandt, H. van de

    2015-01-01

    Synthetic amorphous silica (SAS) like NM-200 is used in a wide variety of technological applications and consumer products. Although SAS has been widely investigated the available reproductive toxicity studies are old and do not cover all requirements of current OECD Guidelines. As part of a

  20. Culture Clash? Investigating constructions of sexual and reproductive health from the perspective of 1.5 generation migrants in Australia using Q methodology.

    Science.gov (United States)

    Dune, T; Perz, J; Mengesha, Z; Ayika, D

    2017-04-04

    In Australia, those who migrate as children or adolescents (1.5 generation migrants) may have entered a new cultural environment at a crucial time in their psychosexual development. These migrants may have to contend with constructions of sexual and reproductive health from at least two cultures which may be at conflict on the matter. This study was designed to investigate the role of culture in constructions of sexual and reproductive health and health care seeking behaviour from the perspective of 1.5 generation migrants. Forty-two adults from various ethno-cultural backgrounds took part in this Q methodological study. Online, participants rank-ordered forty-two statements about constructions of sexual and reproductive health and health seeking behaviours based on the level to which they agreed or disagreed with them. Participants then answered a series of questions about the extent to which their ethnic/cultural affiliations influenced their identity. A by-person factor analysis was then conducted, with factors extracted using the centroid technique and a varimax rotation. A seven-factor solution provided the best conceptual fit for constructions of sexual and reproductive health and help-seeking. Factor A compared progressive and traditional sexual and reproductive health values. Factor B highlighted migrants' experiences through two cultural lenses. Factor C explored migrant understandings of sexual and reproductive health in the context of culture. Factor D explained the role of culture in migrants' intimate relationships, beliefs about migrant sexual and reproductive health and engagement of health care services. Factor E described the impact of culture on sexual and reproductive health related behaviour. Factor F presented the messages migrant youth are given about sexual and reproductive health. Lastly, Factor G compared constructions of sexual and reproductive health across cultures. This study has demonstrated that when the cultural norms of migrants

  1. Effects of benzophenone-3 exposure on endocrine disruption and reproduction of Japanese medaka (Oryzias latipes)—A two generation exposure study

    International Nuclear Information System (INIS)

    Kim, Sujin; Jung, Dawoon; Kho, Younglim; Choi, Kyungho

    2014-01-01

    Highlights: • Exposure to BP-3 led to adverse reproduction effects on Japanese medaka at 26 μg/L. • Changes in sex hormones and steroidogenic gene transcription were observed. • Parental exposure to BP-3 influenced on the growth of second generation fish. - Abstract: Benzophenone-3 (BP-3) has been widely used in sunscreens and cosmetics to protect human skin from the harmful effects of UV irradiation. While BP-3 has been frequently detected in surface waters, sediments and biota, only limited information is available on its in vivo toxicity, particularly in fish. In the present study the endocrine disrupting capacity of BP-3 and its underlying mechanisms were investigated using Japanese medaka (Oryzias latipes). Adult Japanese medaka pairs (F0) were exposed to 0, 4.7, 8.4, 26, or 90 μg/L (or 0, 15, 50, 150, or 500 μg/L of BP-3 based on nominal concentration) for 14 d and its effects on sex steroid hormones, and transcription of various associated genes were determined. Following additional 14 d of exposure, the F1 eggs reproduced were counted and were further exposed to 0, 5.4, 12, or 30 μg/L of BP-3 (or 0, 15, 50, or 150 μg/L based on nominal concentrations) until 30 d after hatching. Chemical analysis of the exposed media confirmed transformation of BP-3 to benzophenone-1 (BP-1), a more potent estrogen agonist. After 14 d of the adult fish exposure, plasma concentrations of testosterone (T) significantly increased in male fish. The 17β-estradiol (E2) to T (E2/T) ratio showed significant decreases in both male and female fish. Overall down-regulation of gonadal steroidogenic genes such as star, cyp11a, cyp17, hsd3b, hsd17b3, and cyp19a was also observed. After 28 d of exposure, the daily average egg reproduction per female was significantly reduced at 26 μg/L of BP-3. However, hatchability of F1 eggs was not affected by continuous exposure. After continued exposure until 30 dph, juvenile fish showed concentration-dependent decrease of condition factor

  2. Effects of benzophenone-3 exposure on endocrine disruption and reproduction of Japanese medaka (Oryzias latipes)—A two generation exposure study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sujin; Jung, Dawoon [School of Public Health, Seoul National University, Seoul 151-742 (Korea, Republic of); Kho, Younglim [Department of Health, Environment and Safety, Eulji University, Seongnam 461-713 (Korea, Republic of); Choi, Kyungho, E-mail: kyungho@snu.ac.kr [School of Public Health, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2014-10-15

    Highlights: • Exposure to BP-3 led to adverse reproduction effects on Japanese medaka at 26 μg/L. • Changes in sex hormones and steroidogenic gene transcription were observed. • Parental exposure to BP-3 influenced on the growth of second generation fish. - Abstract: Benzophenone-3 (BP-3) has been widely used in sunscreens and cosmetics to protect human skin from the harmful effects of UV irradiation. While BP-3 has been frequently detected in surface waters, sediments and biota, only limited information is available on its in vivo toxicity, particularly in fish. In the present study the endocrine disrupting capacity of BP-3 and its underlying mechanisms were investigated using Japanese medaka (Oryzias latipes). Adult Japanese medaka pairs (F0) were exposed to 0, 4.7, 8.4, 26, or 90 μg/L (or 0, 15, 50, 150, or 500 μg/L of BP-3 based on nominal concentration) for 14 d and its effects on sex steroid hormones, and transcription of various associated genes were determined. Following additional 14 d of exposure, the F1 eggs reproduced were counted and were further exposed to 0, 5.4, 12, or 30 μg/L of BP-3 (or 0, 15, 50, or 150 μg/L based on nominal concentrations) until 30 d after hatching. Chemical analysis of the exposed media confirmed transformation of BP-3 to benzophenone-1 (BP-1), a more potent estrogen agonist. After 14 d of the adult fish exposure, plasma concentrations of testosterone (T) significantly increased in male fish. The 17β-estradiol (E2) to T (E2/T) ratio showed significant decreases in both male and female fish. Overall down-regulation of gonadal steroidogenic genes such as star, cyp11a, cyp17, hsd3b, hsd17b3, and cyp19a was also observed. After 28 d of exposure, the daily average egg reproduction per female was significantly reduced at 26 μg/L of BP-3. However, hatchability of F1 eggs was not affected by continuous exposure. After continued exposure until 30 dph, juvenile fish showed concentration-dependent decrease of condition factor

  3. Response to multi-generational selection under elevated [CO2] in two temperature regimes suggests enhanced carbon assimilation and increased reproductive output in Brassica napus L

    DEFF Research Database (Denmark)

    Frenck, Georg; van der Linden, Leon; Mikkelsen, Teis Nørgaard

    2013-01-01

    Functional plant traits are likely to adapt under the sustained pressure imposed by environmental changes through natural selection. Employing Brassica napus as a model, a multi-generational study was performed to investigate the potential trajectories of selection at elevated [CO2] in two differ...... ameliorate depressions in plant reproductive fitness caused by higher temperatures in situations where both factors co-occur....

  4. Impact of ectopic pregnancy for reproductive prognosis in next generation

    DEFF Research Database (Denmark)

    Kårhus, Line Lund; Egerup, Pia; Skovlund, Charlotte Wessel

    2014-01-01

    The impact of an ectopic pregnancy in the next generation is unknown. Our aim was to compare reproductive outcomes in daughters of women with and without ectopic pregnancy. Designed as a historical prospective controlled cohort study with data collected in four Danish registries from 1977-2009, w...

  5. Reproduction of Trichospilus diatraeae in Diatraea saccharalis after three generations in Tenebrio molitor

    Directory of Open Access Journals (Sweden)

    Daniele Fabiana Glaeser

    2014-06-01

    Full Text Available The successive rearing of parasitoids in factitious hosts may affect its biological quality. Trichospilus diatraeae Cherian & Margabandhu, 1942 (Hymenoptera: Eulophidae has been studied for the biological control of sugarcane borer [Diatraea saccharalis (Fabricius, 1794 (Lepidoptera: Crambidae]. This study aimed to evaluate whether the rearing of T. diatraeae for three generations in the factitious host Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae affects its reproductive performance, when subsequently reared in the natural host pupae D. saccharalis. Two groups of T. diatraeae were reared separately for three generations: one in pupae of T. molitor and the other in pupae of D. saccharalis. Subsequently, 20 pupae of D. saccharalis were exposed, for 72 hours, to the parasitism of T. diatraeae females reared earlier in pupae of T. molitor or D. saccharalis. The successive rearing of T. diatraeae in the factitious host did not affect the number of pupae parasitized and the number of pupae in which the emergence of parasitoids occurred in the natural host D. saccharalis, and increased the longevity of females and the sex ratio of T. diatraeae. The progeny, duration of developmental cycle (egg to adult, width of head capsule of males and females and longevity of males of T. diatraeae were similar on both treatments. T. diatraeae can be reared in the factitious host T. molitor for three generations without compromising its reproductive performance, when subsequently reared in the natural host D. saccharalis.

  6. The effects of in utero bisphenol A exposure on reproductive capacity in several generations of mice

    International Nuclear Information System (INIS)

    Ziv-Gal, Ayelet; Wang, Wei; Zhou, Changqing; Flaws, Jodi A.

    2015-01-01

    In utero bisphenol A (BPA) exposure affects reproductive function in the first generation (F1) of mice; however, not many studies have examined the reproductive effects of BPA exposure on subsequent generations. In this study, pregnant mice (F0) were orally dosed with vehicle, BPA (0.5, 20, and 50 μg/kg/day) or diethylstilbestrol (DES; 0.05 μg/kg/day) daily from gestation day 11 until birth. F1 females were used to generate the F2 generation, and F2 females were used to generate the F3 generation. Breeding studies at the ages of 3, 6, and 9 months were conducted to evaluate reproductive capacity over time. Further, studies were conducted to evaluate pubertal onset, litter size, and percentage of dead pups; and to calculate pregnancy rate, and mating, fertility, and gestational indices. The results indicate that BPA exposure (0.5 and 50 μg/kg/day) significantly delayed the age at vaginal opening in the F3 generation compared to vehicle control. Both DES (0.05 μg/kg/day) and BPA (50 μg/kg/day) significantly delayed the age at first estrus in the F3 generation compared to vehicle control. BPA exposure reduced gestational index in the F1 and F2 generations compared to control. Further, BPA exposure (0.5 μg/kg/day) compromised the fertility index in the F3 generation compared to control. Finally, in utero BPA exposure reduced the ability of female mice to maintain pregnancies as they aged. Collectively, these data suggest that BPA exposure affects reproductive function in female mice and that some effects may be transgenerational in nature. - Highlights: • In utero BPA delayed vaginal opening in the F3 generation compared to control. • In utero BPA delayed estrus in the F3 generation compared to control. • In utero BPA reduced the ability of F1 and F2 female mice to maintain pregnancies. • In utero BPA compromised the ability of F3 female mice to become pregnant. • Some effects of in utero BPA may be transgenerational in nature

  7. The effects of in utero bisphenol A exposure on reproductive capacity in several generations of mice

    Energy Technology Data Exchange (ETDEWEB)

    Ziv-Gal, Ayelet, E-mail: zivgal1@illinois.edu; Wang, Wei, E-mail: weiwang2@illinois.edu; Zhou, Changqing, E-mail: czhou27@illinois.edu; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2015-05-01

    In utero bisphenol A (BPA) exposure affects reproductive function in the first generation (F1) of mice; however, not many studies have examined the reproductive effects of BPA exposure on subsequent generations. In this study, pregnant mice (F0) were orally dosed with vehicle, BPA (0.5, 20, and 50 μg/kg/day) or diethylstilbestrol (DES; 0.05 μg/kg/day) daily from gestation day 11 until birth. F1 females were used to generate the F2 generation, and F2 females were used to generate the F3 generation. Breeding studies at the ages of 3, 6, and 9 months were conducted to evaluate reproductive capacity over time. Further, studies were conducted to evaluate pubertal onset, litter size, and percentage of dead pups; and to calculate pregnancy rate, and mating, fertility, and gestational indices. The results indicate that BPA exposure (0.5 and 50 μg/kg/day) significantly delayed the age at vaginal opening in the F3 generation compared to vehicle control. Both DES (0.05 μg/kg/day) and BPA (50 μg/kg/day) significantly delayed the age at first estrus in the F3 generation compared to vehicle control. BPA exposure reduced gestational index in the F1 and F2 generations compared to control. Further, BPA exposure (0.5 μg/kg/day) compromised the fertility index in the F3 generation compared to control. Finally, in utero BPA exposure reduced the ability of female mice to maintain pregnancies as they aged. Collectively, these data suggest that BPA exposure affects reproductive function in female mice and that some effects may be transgenerational in nature. - Highlights: • In utero BPA delayed vaginal opening in the F3 generation compared to control. • In utero BPA delayed estrus in the F3 generation compared to control. • In utero BPA reduced the ability of F1 and F2 female mice to maintain pregnancies. • In utero BPA compromised the ability of F3 female mice to become pregnant. • Some effects of in utero BPA may be transgenerational in nature.

  8. Multiple factors contribute to reproductive isolation between two co-existing Habenaria species (Orchidaceae.

    Directory of Open Access Journals (Sweden)

    Wenliu Zhang

    Full Text Available Reproductive isolation is a key feature that forms barriers to gene flow between distinct plants. In orchids, prezygotic reproductive isolation has been considered to be strong, because their associations with highly specific pollinators. In this study, the reproductive ecology and reproductive isolation of two sympatric Habenaria species, H. davidii and H. fordii, was investigated by floral phenology and morphology, hand-pollination experiments and visitor observation in southwest China. The two species were dependent on insects for pollination and completely self-compatible. A number of factors have been identified to limit gene flow between the two species and achieved full reproductive isolation. Ecogeographic isolation was a weak barrier. H. fordii and H. davidii had completely overlapped flowering periods, and floral morphology plays an important role in floral isolation. The two species shared the same hawkmoth pollinator, Cechenena lineosa, but the pollinaria of the two orchids were attached on different body parts of pollinators. Prezygotic isolation was not complete, but the interspecific pollination treatments of each species resulted in no seed sets, indicating that unlike many other orchid species, in which the postzygotic reproductive isolation is very weak or complete absence, the post-zygotic isolation strongly acted in the stage of seed production between two species. The results illustrate the reproductive isolation between two species involves multiple plant life-history stages and a variety of reproductive barriers can contribute to overall isolation.

  9. Unisexual and heterosexual meiotic reproduction generate aneuploidy and phenotypic diversity de novo in the yeast Cryptococcus neoformans.

    Directory of Open Access Journals (Sweden)

    Min Ni

    2013-09-01

    Full Text Available Aneuploidy is known to be deleterious and underlies several common human diseases, including cancer and genetic disorders such as trisomy 21 in Down's syndrome. In contrast, aneuploidy can also be advantageous and in fungi confers antifungal drug resistance and enables rapid adaptive evolution. We report here that sexual reproduction generates phenotypic and genotypic diversity in the human pathogenic yeast Cryptococcus neoformans, which is globally distributed and commonly infects individuals with compromised immunity, such as HIV/AIDS patients, causing life-threatening meningoencephalitis. C. neoformans has a defined a-α opposite sexual cycle; however, >99% of isolates are of the α mating type. Interestingly, α cells can undergo α-α unisexual reproduction, even involving genotypically identical cells. A central question is: Why would cells mate with themselves given that sex is costly and typically serves to admix preexisting genetic diversity from genetically divergent parents? In this study, we demonstrate that α-α unisexual reproduction frequently generates phenotypic diversity, and the majority of these variant progeny are aneuploid. Aneuploidy is responsible for the observed phenotypic changes, as chromosome loss restoring euploidy results in a wild-type phenotype. Other genetic changes, including diploidization, chromosome length polymorphisms, SNPs, and indels, were also generated. Phenotypic/genotypic changes were not observed following asexual mitotic reproduction. Aneuploidy was also detected in progeny from a-α opposite-sex congenic mating; thus, both homothallic and heterothallic sexual reproduction can generate phenotypic diversity de novo. Our study suggests that the ability to undergo unisexual reproduction may be an evolutionary strategy for eukaryotic microbial pathogens, enabling de novo genotypic and phenotypic plasticity and facilitating rapid adaptation to novel environments.

  10. Cross-Generational Reproductive Fitness Enforced by Microchimeric Maternal Cells.

    Science.gov (United States)

    Kinder, Jeremy M; Jiang, Tony T; Ertelt, James M; Xin, Lijun; Strong, Beverly S; Shaaban, Aimen F; Way, Sing Sing

    2015-07-30

    Exposure to maternal tissue during in utero development imprints tolerance to immunologically foreign non-inherited maternal antigens (NIMA) that persists into adulthood. The biological advantage of this tolerance, conserved across mammalian species, remains unclear. Here, we show maternal cells that establish microchimerism in female offspring during development promote systemic accumulation of immune suppressive regulatory T cells (Tregs) with NIMA specificity. NIMA-specific Tregs expand during pregnancies sired by males expressing alloantigens with overlapping NIMA specificity, thereby averting fetal wastage triggered by prenatal infection and non-infectious disruptions of fetal tolerance. Therefore, exposure to NIMA selectively enhances reproductive success in second-generation females carrying embryos with overlapping paternally inherited antigens. These findings demonstrate that genetic fitness, canonically thought to be restricted to Mendelian inheritance, is enhanced in female placental mammals through vertically transferred maternal cells that promote conservation of NIMA and enforce cross-generational reproductive benefits. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Artificial reproduction of two different spawn-forms of the chub.

    Science.gov (United States)

    Krejszeff, Sławomir; Targońska, Katarzyna; Zarski, Daniel; Kucharczyk, Dariusz

    2010-03-01

    The aim of this study was to compare, under controlled conditions, reproduction results of cultured and wild stock of the chub. Wild fish spawned only once a season whereas the cultured stock spawned at least two times. In the multiple-spawn stock, fewer fish spawned and the weight of produced oocytes was reduced compared to the single-spawn stock. Larvae obtained from the multi-spawn forms were smaller than those of the single-spawn stock. The occurrence of one species with two forms of spawning performance in the same area makes it difficult to develop an efficient method for controlling the reproduction.

  12. Reproductive solution for grade-two fluid model in two dimensions

    Directory of Open Access Journals (Sweden)

    L. Friz

    2009-06-01

    Full Text Available We treat the existence of reproductive solution (weak periodic solution of a second-grade fluid system in two dimensions, by using the Galerkin approximation method and compactness arguments.

  13. Coordination of size-control, reproduction and generational memory in freshwater planarians

    Science.gov (United States)

    Yang, Xingbo; Kaj, Kelson J.; Schwab, David J.; Collins, Eva-Maria S.

    2017-06-01

    Uncovering the mechanisms that control size, growth, and division rates of organisms reproducing through binary division means understanding basic principles of their life cycle. Recent work has focused on how division rates are regulated in bacteria and yeast, but this question has not yet been addressed in more complex, multicellular organisms. We have, over the course of several years, assembled a unique large-scale data set on the growth and asexual reproduction of two freshwater planarian species, Dugesia japonica and Girardia tigrina, which reproduce by transverse fission and succeeding regeneration of head and tail pieces into new planarians. We show that generation-dependent memory effects in planarian reproduction need to be taken into account to accurately capture the experimental data. To achieve this, we developed a new additive model that mixes multiple size control strategies based on planarian size, growth, and time between divisions. Our model quantifies the proportions of each strategy in the mixed dynamics, revealing the ability of the two planarian species to utilize different strategies in a coordinated manner for size control. Additionally, we found that head and tail offspring of both species employ different mechanisms to monitor and trigger their reproduction cycles. Thus, we find a diversity of strategies not only between species but between heads and tails within species. Our additive model provides two advantages over existing 2D models that fit a multivariable splitting rate function to the data for size control: firstly, it can be fit to relatively small data sets and can thus be applied to systems where available data is limited. Secondly, it enables new biological insights because it explicitly shows the contributions of different size control strategies for each offspring type.

  14. Two Y genes can replace the entire Y chromosome for assisted reproduction in the mouse.

    Science.gov (United States)

    Yamauchi, Yasuhiro; Riel, Jonathan M; Stoytcheva, Zoia; Ward, Monika A

    2014-01-03

    The Y chromosome is thought to be important for male reproduction. We have previously shown that, with the use of assisted reproduction, live offspring can be obtained from mice lacking the entire Y chromosome long arm. Here, we demonstrate that live mouse progeny can also be generated by using germ cells from males with the Y chromosome contribution limited to only two genes, the testis determinant factor Sry and the spermatogonial proliferation factor Eif2s3y. Sry is believed to function primarily in sex determination during fetal life. Eif2s3y may be the only Y chromosome gene required to drive mouse spermatogenesis, allowing formation of haploid germ cells that are functional in assisted reproduction. Our findings are relevant, but not directly translatable, to human male infertility cases.

  15. Potential of human twin embryos generated by embryo splitting in assisted reproduction and research.

    Science.gov (United States)

    Noli, Laila; Ogilvie, Caroline; Khalaf, Yacoub; Ilic, Dusko

    2017-03-01

    Embryo splitting or twinning has been widely used in veterinary medicine over 20 years to generate monozygotic twins with desirable genetic characteristics. The first human embryo splitting, reported in 1993, triggered fierce ethical debate on human embryo cloning. Since Dolly the sheep was born in 1997, the international community has acknowledged the complexity of the moral arguments related to this research and has expressed concerns about the potential for reproductive cloning in humans. A number of countries have formulated bans either through laws, decrees or official statements. However, in general, these laws specifically define cloning as an embryo that is generated via nuclear transfer (NT) and do not mention embryo splitting. Only the UK includes under cloning both embryo splitting and NT in the same legislation. On the contrary, the Ethics Committee of the American Society for Reproductive Medicine does not have a major ethical objection to transferring two or more artificially created embryos with the same genome with the aim of producing a single pregnancy, stating that 'since embryo splitting has the potential to improve the efficacy of IVF treatments for infertility, research to investigate the technique is ethically acceptable'. Embryo splitting has been introduced successfully to the veterinary medicine several decades ago and today is a part of standard practice. We present here an overview of embryo splitting experiments in humans and non-human primates and discuss the potential of this technology in assisted reproduction and research. A comprehensive literature search was carried out using PUBMED and Google Scholar databases to identify studies on embryo splitting in humans and non-human primates. 'Embryo splitting' and 'embryo twinning' were used as the keywords, alone or in combination with other search phrases relevant to the topics of biology of preimplantation embryos. A very limited number of studies have been conducted in humans and non

  16. Asymmetric reproductive isolation between two sympatric annual killifish with extremely short lifespans.

    Directory of Open Access Journals (Sweden)

    Matej Polačik

    Full Text Available BACKGROUND: Interspecific reproductive isolation is typically achieved by a combination of intrinsic and extrinsic barriers. Behavioural isolating barriers between sympatric, closely related species are often of primary importance and frequently aided by extrinsic factors causing spatial and temporal interspecific separation. Study systems with a severely limited role of extrinsic factors on reproductive isolation may provide valuable insights into how reproductive isolation between sympatric species is maintained. We used no-choice experimental set-up to study reproductive barriers between two closely related sympatric African killifish species, Nothobranchius furzeri and Nothobranchius orthonotus. These fish live in small temporary savannah pools and have complete spatial and temporal overlap in reproductive activities and share a similar ecology. PRINCIPAL FINDINGS: We found that the two species display largely incomplete and asymmetric reproductive isolation. Mating between N. furzeri males and N. orthonotus females was absent under standard experimental conditions and eggs were not viable when fish were forced to mate in a modified experimental setup. In contrast, male N. orthonotus indiscriminately mated with N. furzeri females, the eggs were viable, and offspring successfully hatched. Most spawnings, however, were achieved by male coercion and egg production and embryo survival were low. Behavioural asymmetry was likely facilitated by mating coercion from larger males of N. orthonotus and at relatively low cost to females. Interestingly, the direction of asymmetry was positively associated with asymmetry in post-mating reproductive barriers. SIGNIFICANCE: We showed that, in fish species with a promiscuous mating system and multiple matings each day, selection for strong mate preferences was relaxed. This effect was likely due to the small proportion of resources allocated to each single mating and the high potential cost to females from

  17. Force Reproduction Error Depends on Force Level, whereas the Position Reproduction Error Does Not

    NARCIS (Netherlands)

    Onneweer, B.; Mugge, W.; Schouten, Alfred Christiaan

    2016-01-01

    When reproducing a previously perceived force or position humans make systematic errors. This study determined the effect of force level on force and position reproduction, when both target and reproduction force are self-generated with the same hand. Subjects performed force reproduction tasks at

  18. Reproductive rights approach to reproductive health in developing countries

    OpenAIRE

    Pillai, Vijayan Kumara; Gupta, Rashmi

    2011-01-01

    Background: Research on reproductive health in developing countries focuses mostly on the role of economic development on various components of reproductive health. Cross-sectional and empirical research studies in particular on the effects of non-economic factors such as reproductive rights remain few and far between. Objective: This study investigates the influence of two components of an empowerment strategy, gender equality, and reproductive rights on women’s reproductive health in develo...

  19. Allocation to reproduction and relative reproductive costs in two species of dioecious Anacardiaceae with contrasting phenology.

    Science.gov (United States)

    Matsuyama, Shuhei; Sakimoto, Michinori

    2008-06-01

    The cost of reproduction in dioecious plants is often female-biased. However, several studies have reported no difference in costs of reproduction between the sexes. In this study, the relative reproductive allocation and costs at the shoot and whole-plant levels were examined in woody dioecious Rhus javanica and R. trichocarpa, in order to examine differences between types of phenophase (i.e. physiological stage of development). Male and female Rhus javanica and R. trichocarpa were sampled and the reproductive and vegetative allocation of the shoot were estimated by harvesting reproductive current-year shoots during flowering and fruiting. Measurements were made of the number of reproductive and total current-year shoots per whole plant, and of the basal area increment (BAI). The numbers of reproductive and total current-year shoots per 1-year-old shoot were counted in order to examine the costs in the following year at the shoot level. A female-biased annual reproductive allocation was found; however, the ratio of reproductive current-year shoots per tree and the BAI did not differ between sexes in Rhus javanica and R. trichocarpa. The percentage of 1-year-old shoots with at least one reproductive current-year shoot was significantly male-biased in R. trichocarpa, but not in R. javanica, indicating that there was a relative cost at the shoot level only in R. trichocarpa. The female-biased leaf mass per shoot, an indicator of compensation for costs, was only found in R. javanica. Relative reproductive costs at the shoot level were detected in Rhus trichocarpa, which has simultaneous leafing and flowering, but not in R. javanica, which has leafing followed by flowering. However, the costs for the whole-plant level were diminished in both species. The results suggest that the phenophase type may produce the different costs for R. javanica and R. trichocarpa through the development of a compensation mechanism.

  20. Impact of two specialist insect herbivores on reproduction of horse nettle, Solanum carolinense.

    Science.gov (United States)

    Wise, Michael J; Sacchi, Christopher F

    1996-10-01

    The frequency of coevolution as a process of strong mutual interaction between a single plant and herbivore species has been questioned in light of more commonly observed, complex relationships between a plant and a suite of herbivore species. Despite recognition of the possibility of diffuse coevolution, relatively few studies have examined ecological responses of plants to herbivores in complex associations. We studied the impact of two specialist herbivores, the horse nettle beetle, Leptinotarsa juncta, and the eggplant flea beetle, Epitrix fuscula, on reproduction of their host, Solanum carolinense. Our study involved field and controlled-environment experimental tests of the impact on sexual and potential asexual reproduction of attack by individuals of the two herbivore species, individually and in combination. Field tests demonstrated that under normal levels of phytophagous insect attack, horse nettle plants experienced a reduction in fruit production of more than 75% compared with plants from which insects were excluded. In controlled-environment experiments using enclosure-exclosure cages, the horse nettle's two principal herbivores, the flea beetle and the horse nettle beetle, caused decreases in sexual reproduction similar to those observed in the field, and a reduction in potential asexual reproduction, represented by root biomass. Attack by each herbivore reduced the numbers of fruits produced, and root growth, when feeding in isolation. When both species were feeding together, fruit production, but not root growth, was lower than when either beetle species fed alone. Ecological interactions between horse nettle and its two primary herbivores necessary for diffuse coevolution to occur were evident from an overall analysis of the statistical interactions between the two herbivores for combined assessment of fruit and vegetative traits. For either of these traits alone, the interactions necessary to promote diffuse coevolution apparently were lacking.

  1. Testing for reproductive interference in the population dynamics of two congeneric species of herbivorous mites

    Science.gov (United States)

    Sato, Y; Alba, J M; Sabelis, M W

    2014-01-01

    When phylogenetically close, two competing species may reproductively interfere, and thereby affect their population dynamics. We tested for reproductive interference (RI) between two congeneric haplo-diploid spider mites, Tetranychus evansi and Tetranychus urticae, by investigating their interspecific mating and their population dynamics when they competed on the same plants. They are both pests of tomato, but differ in the host plant defences that they suppress or induce. To reduce the effect of plant-mediated interaction, we used a mutant tomato plant lacking jasmonate-mediated anti-herbivore defences in the competition experiment. In addition, to manipulate the effect of RI, we introduced founder females already mated with conspecific males in mild RI treatments or founder, virgin females in strong RI treatments (in either case together with heterospecific and conspecific males). As females show first-male sperm precedence, RI should occur especially in the founder generation under strong RI treatments. We found that T. urticae outcompeted T. evansi in mild, but not in strong RI treatments. Thus, T. evansi interfered reproductively with T. urticae. This result was supported by crossing experiments showing frequent interspecific copulations, strong postmating reproductive isolation and a preference of T. evansi males to mate with T. urticae (instead of conspecific) females, whereas T. urticae males preferred conspecific females. We conclude that interspecific mating comes at a cost due to asymmetric mate preferences of males. Because RI by T. evansi can improve its competitiveness to T. urticae, we propose that RI partly explains why T. evansi became invasive in Europe where T. urticae is endemic. PMID:24865602

  2. THE GENERATIVE REPRODUCTIVE CHARACTERISTICS OF RED DRAGON FRUIT (Hylocereus.polyrhizus (Web. Britton & Rose, CACTACEAE

    Directory of Open Access Journals (Sweden)

    Eniek Kriswiyanti

    2013-04-01

    Full Text Available This study aimed to investigate the generative reproductive characteristics of red dragon fruit (Hylocereus polyrhizus (Web. Britton & Rose, that is the characteristics and the development of male and female reproductive system and the embryo. The flowering morphology was observed through the gametogenesis process and the process of embryogenesis was observed using the methods of squash, cytolysis, and embedding of flower before anthesis, during and after anthesis. The results showed that the flower funnelled form with many calyxes, stamens and crowns. The pollen was circular, sulcus, trilate, reticulate, and spheroid. The development of microgametophyte was at the 2nd stages with three nucleuses and the pistil developed after anthesis.  Anthesis was taken place at night time, fertilization and pollen developed before anthesis and has not germinating. A single pistil, the head of pistil with many branches, the style longer than the stamen, open type.  Seeds anathrophus, endosperm and embryo with the globular shaped, developed 5 days after anthesis, the embryo torpedo likes and the differentiation of primer tissues seen in the seeds 7 days after anthesis, and arilus generated from development of megasporangium. Keywords: embedding, self incompatibility, sferoidal, anatrophus, arillus.

  3. Size Dependent Male Reproductive Tactic in the Two-Spotted Goby (Gobiusculus flavescens).

    Science.gov (United States)

    Utne-Palm, A C; Eduard, K; Jensen, K H; Mayer, I; Jakobsen, P J

    2015-01-01

    Male investment in testes and sperm duct gland in the polygamous nest breeding two-spotted goby Gobiusculus flavescens (Fabricius) was investigated in relation to time in reproductive season and individual physical parameters. This small teleost fish is most likely the most abundant species found along the rocky shores of the North East Atlantic. The two-spotted goby has a single reproductive season, during which nest-caring males can raise several clutches of offspring. According to the literature the males are on average larger than the females. Here we report for the first time a population showing a reversal of this trend, with males on average being smaller than females, a difference likely caused by a large proportion of small males. Early in the breeding season these small males have typical sneaker characters, with relatively large testes and small seminal duct glands compared to the larger dominant territorial males. The presence of these two alternative male reproductive tactics is confirmed by histological studies, which shows the presence of sperm in the sperm duct glands (SDG) of smaller males, but not in the SDG of intermediate and larger males. To our knowledge, males with typical sneaker characters have not been reported in earlier studied populations of two-spotted goby. Interestingly we found that testes investment declined significantly over the course of the breeding season, and that this reduction was significantly more pronounced in small compared to the large males. Further, a significant increase in seminal duct gland (SDG) mass was observed for the smaller males over the breeding season. We propose that this indicates a possible shift in mating tactic by smaller males from a parasitic to a nest-holding tactic over the course of the breeding season. Thus, the observed size dependent plasticity in investment in SDG over time suggests that the reproductive tactic of G. flavescens is conditional, and possibly influenced by mate availability and

  4. Size Dependent Male Reproductive Tactic in the Two-Spotted Goby (Gobiusculus flavescens.

    Directory of Open Access Journals (Sweden)

    A C Utne-Palm

    Full Text Available Male investment in testes and sperm duct gland in the polygamous nest breeding two-spotted goby Gobiusculus flavescens (Fabricius was investigated in relation to time in reproductive season and individual physical parameters. This small teleost fish is most likely the most abundant species found along the rocky shores of the North East Atlantic. The two-spotted goby has a single reproductive season, during which nest-caring males can raise several clutches of offspring. According to the literature the males are on average larger than the females. Here we report for the first time a population showing a reversal of this trend, with males on average being smaller than females, a difference likely caused by a large proportion of small males. Early in the breeding season these small males have typical sneaker characters, with relatively large testes and small seminal duct glands compared to the larger dominant territorial males. The presence of these two alternative male reproductive tactics is confirmed by histological studies, which shows the presence of sperm in the sperm duct glands (SDG of smaller males, but not in the SDG of intermediate and larger males. To our knowledge, males with typical sneaker characters have not been reported in earlier studied populations of two-spotted goby. Interestingly we found that testes investment declined significantly over the course of the breeding season, and that this reduction was significantly more pronounced in small compared to the large males. Further, a significant increase in seminal duct gland (SDG mass was observed for the smaller males over the breeding season. We propose that this indicates a possible shift in mating tactic by smaller males from a parasitic to a nest-holding tactic over the course of the breeding season. Thus, the observed size dependent plasticity in investment in SDG over time suggests that the reproductive tactic of G. flavescens is conditional, and possibly influenced by mate

  5. Long-term fiscal implications of funding assisted reproduction: a generational accounting model for Spain

    Directory of Open Access Journals (Sweden)

    R. Matorras

    2015-12-01

    Full Text Available The aim of this study was to assess the lifetime economic benefits of assisted reproduction in Spain by calculating the return on this investment. We developed a generational accounting model that simulates the flow of taxes paid by the individual, minus direct government transfers received over the individual’s lifetime. The difference between discounted transfers and taxes minus the cost of either IVF or artificial insemination (AI equals the net fiscal contribution (NFC of a child conceived through assisted reproduction. We conducted sensitivity analysis to test the robustness of our results under various macroeconomic scenarios. A child conceived through assisted reproduction would contribute €370,482 in net taxes to the Spanish Treasury and would receive €275,972 in transfers over their lifetime. Taking into account that only 75% of assisted reproduction pregnancies are successful, the NFC was estimated at €66,709 for IVF-conceived children and €67,253 for AI-conceived children. The return on investment for each euro invested was €15.98 for IVF and €18.53 for AI. The long-term NFC of a child conceived through assisted reproduction could range from €466,379 to €-9,529 (IVF and from €466,923 to €-8,985 (AI. The return on investment would vary between €-2.28 and €111.75 (IVF, and €-2.48 and €128.66 (AI for each euro invested. The break-even point at which the financial position would begin to favour the Spanish Treasury ranges between 29 and 41 years of age. Investment in assisted reproductive techniques may lead to positive discounted future fiscal revenue, notwithstanding its beneficial psychological effect for infertile couples in Spain.

  6. Comparison between two forms of vaginally administered progesterone for luteal phase support in assisted reproduction cycles.

    Science.gov (United States)

    Geber, Selmo; Moreira, Ana Carolina Ferreira; de Paula, Sálua Oliveira Calil; Sampaio, Marcos

    2007-02-01

    The use of progesterone for luteal phase support has been demonstrated to be beneficial in assisted reproduction cycles using gonadotrophin-releasing hormone analogues (GnRHa). Two micronized progesterone preparations are available for vaginal administration: capsules and gel. The objective of this study was to compare the efficacy of these two forms for luteal phase support in assisted reproduction cycles. A total of 244 couples undergoing IVF/intracytoplasmic sperm injection cycles were included in the study and were randomly allocated (sealed envelopes) into two groups: group 1 (122) received vaginal capsules of 200 mg of micronized progesterone (Utrogestan), 3 times daily, and group 2 (122) received micronized progesterone in gel (Crinone 8%), once daily. Both groups received progesterone for 13 days beginning day 1 after oocyte retrieval, continuing until the pregnancy test was performed and until 12 weeks of pregnancy. Groups were compared by clinical data and assisted reproduction results and had similar ages and causes of infertility. Although the pregnancy rate was higher for those receiving progesterone gel than capsules (44.26 and 36.06% respectively), this difference was not statistically significant. The study showed that vaginal progesterone gel and capsules used for luteal phase support in assisted reproduction cycles with long protocol GnRHa result in similar pregnancy rates.

  7. Temperature modulates dengue virus epidemic growth rates through its effects on reproduction numbers and generation intervals.

    Science.gov (United States)

    Siraj, A. S.; Oidtman, R. J.; Huber, J. H.; Kraemer, M. U.; Brady, O. J.; Johansson, M. A.; Perkins, T. A.

    2017-12-01

    Epidemic growth rate, r, provides a more complete description of the potential for epidemics than the more commonly studied basic reproduction number, R0, yet the former has never been described as a function of temperature for dengue virus or other pathogens with temperature-sensitive transmission. The need to understand the drivers of epidemics of these pathogens is acute, with arthropod-borne virus epidemics becoming increasingly problematic. We addressed this need by developing temperature-dependent descriptions of the two components of r—R0 and the generation interval—to obtain a temperature-dependent description of r. Our results show that the generation interval is highly sensitive to temperature, decreasing twofold between 25 and 35 °C and suggesting that dengue virus epidemics may accelerate as temperatures increase, not only because of more infections per generation but also because of faster generations. Under the empirical temperature relationships that we considered, we found that r peaked at a temperature threshold that was robust to uncertainty in model parameters that do not depend on temperature. Although the precise value of this temperature threshold could be refined following future studies of empirical temperature relationships, the framework we present for identifying such temperature thresholds offers a new way to classify regions in which dengue virus epidemic intensity could either increase or decrease under future climate change.

  8. Evaluation of two dairy herd reproductive performance indicators that are adjusted for voluntary waiting period

    Directory of Open Access Journals (Sweden)

    Löf Emma

    2012-01-01

    Full Text Available Abstract Background Overall reproductive performance of dairy herds is monitored by various indicators. Most of them do not consider all eligible animals and do not consider different management strategies at farm level. This problem can be alleviated by measuring the proportion of pregnant cows by specific intervals after their calving date or after a fixed time period, such as the voluntary waiting period. The aim of this study was to evaluate two reproductive performance indicators that consider the voluntary waiting period at the herd. The two indicators were: percentage of pregnant cows in the herd after the voluntary waiting period plus 30 days (PV30 and percentage of inseminated cows in the herd after the voluntary waiting period plus 30 days (IV30. We wanted to assess how PV30 and IV30 perform in a simulation of herds with different reproductive management and physiology and to compare them to indicators of reproductive performance that do not consider the herd voluntary waiting period. Methods To evaluate the reproductive indicators we used the SimHerd-program, a stochastic simulation model, and 18 scenarios were simulated. The scenarios were designed by altering the reproductive management efficiency and the status of reproductive physiology of the herd. Logistic regression models, together with receiver operating characteristics (ROC, were used to examine how well the reproductive performance indicators could discriminate between herds of different levels of reproductive management efficiency or reproductive physiology. Results The logistic regression models with the ROC analysis showed that IV30 was the indicator that best discriminated between different levels of management efficiency followed by PV30, calving interval, 200-days not-in calf-rate (NotIC200, in calf rate at100-days (IC100 and a fertility index. For reproductive physiology the ROC analysis showed that the fertility index was the indicator that best discriminated

  9. Chronic pelvic pain in women of reproductive and post-reproductive age: a population-based study.

    Science.gov (United States)

    Ayorinde, A A; Bhattacharya, S; Druce, K L; Jones, G T; Macfarlane, G J

    2017-03-01

    Epidemiological studies on chronic pelvic pain (CPP) have focused on women of reproductive age. We aimed to determine the prevalence of chronic pelvic pain (CPP) in adult women and the differences in associated factors among women of reproductive age and older women. In addition, to determine whether distinct subgroups existed among CPP cases. A cross-sectional postal survey was conducted among 5300 randomly selected women aged ≥25 years resident in the Grampian region, UK. Multivariable logistic regression was used to determine pregnancy-related and psychosocial factors associated with CPP. To identify subgroups of CPP cases, we performed cluster analysis using variables of pain severity, psychosocial factors and pain coping strategies. Of 2088 participants, 309 (14.8%) reported CPP. CPP was significantly associated with being of reproductive age (odds ratios (OR) 2.43, 95% CI 1.69-3.48), multiple non-pain somatic symptoms (OR 3.58 95% CI 2.23-5.75), having fatigue (OR mild 1.74 95% CI 1.24-2.44, moderate/severe 1.82, 95% CI 1.25-2.63) and having depression (OR 1.61, 95% CI 1.09-2.38). CPP was less associated with multiple non-pain somatic symptoms in women of reproductive age compared to older women (interaction OR 0.51, 95% CI 0.28-0.92). We identified two clusters of CPP cases; those having little/no psychosocial distress and those having high psychosocial distress. CPP is common in both age groups, though women of reproductive age are more likely to report it. Heightened somatic awareness may be more strongly associated with CPP in older women. There are distinct groups of CPP cases characterized by the absence/presence of psychosocial distress. Heightened somatic awareness may be more strongly associated with CPP in women of post-reproductive years compared to women of reproductive years. Two subgroups of CPP cases can be differentiated by the absence/presence of psychosocial distress suggesting that stratified management approach may be more efficient.

  10. Generational Reproduction of child abuse

    OpenAIRE

    García Ampudia, Lupe; Orellana M., Oswaldo; Pomalaya V., Ricardo; Yanac Reynoso, Elisa; Malaver S., Carmela; Herrera F., Edgar; Sotelo L., Noemi; Campos C., Lilia; Sotelo L., Lidia; Orellana García, Daphne; Velasquez M., Katherine

    2014-01-01

    The objective of this research is the study of the abuse rising in two generations, of parents and children and establishing the relationship between background child’s abuse with the potential abuse. The sample is comprised of 441 students and 303 parents who agreed to answer the Memories of Abuse Questionnaire. The used instruments were the Child History Questionnaire adapted for the purpose of this research, the Inventory of Potential Child Abuse (Milner, J. 1977), adapted by De Paul, Arru...

  11. Reproductive rights approach to reproductive health in developing countries

    Directory of Open Access Journals (Sweden)

    Vijayan K. Pillai

    2011-12-01

    Full Text Available Research on reproductive health in developing countries focuses mostly on the role of economic development on various components of reproductive health. Cross-sectional and empirical research studies in particular on the effects of non-economic factors such as reproductive rights remain few and far between.This study investigates the influence of two components of an empowerment strategy, gender equality, and reproductive rights on women's reproductive health in developing countries. The empowerment strategy for improving reproductive health is theoretically situated on a number of background factors such as economic and social development.Cross-national socioeconomic and demographic data from a number of international organizations on 142 developing countries are used to test a model of reproductive rights and reproductive health.The findings suggest that both economic and democratic development have significant positive effects on levels of gender equality. The level of social development plays a prominent role in promoting reproductive rights. It is found that reproductive rights channel the influences of social structural factors and gender equality on reproductive health.

  12. Reproductive rights approach to reproductive health in developing countries.

    Science.gov (United States)

    Pillai, Vijayan K; Gupta, Rashmi

    2011-01-01

    Research on reproductive health in developing countries focuses mostly on the role of economic development on various components of reproductive health. Cross-sectional and empirical research studies in particular on the effects of non-economic factors such as reproductive rights remain few and far between. This study investigates the influence of two components of an empowerment strategy, gender equality, and reproductive rights on women's reproductive health in developing countries. The empowerment strategy for improving reproductive health is theoretically situated on a number of background factors such as economic and social development. Cross-national socioeconomic and demographic data from a number of international organizations on 142 developing countries are used to test a model of reproductive rights and reproductive health. The findings suggest that both economic and democratic development have significant positive effects on levels of gender equality. The level of social development plays a prominent role in promoting reproductive rights. It is found that reproductive rights channel the influences of social structural factors and gender equality on reproductive health.

  13. Genetic selection on abdominal fat content alters the reproductive performance of broilers.

    Science.gov (United States)

    Zhang, X Y; Wu, M Q; Wang, S Z; Zhang, H; Du, Z Q; Li, Y M; Cao, Z P; Luan, P; Leng, L; Li, H

    2018-06-01

    The effects of obesity on reproduction have been widely reported in humans and mice. The present study was designed to compare the reproductive performance of lean and fat chicken lines, divergently selected for abdominal fat content. The following parameters were determined and analyzed in the two lines: (1) reproductive traits, including age at first egg and total egg numbers from generations 14 to 18, absolute and relative testicular weights at 7, 14, 25, 30, 45 and 56 weeks of age, semen quality at 30, 45 and 56 weeks of age in generation 18, and fertility and hatchability from generations 14 to 18; (2) reproductive hormones at 7, 14, 25, 30, 45 and 56 weeks of age in generation 18; (3) and the relative mRNA abundance of genes involved in reproduction at 7, 14, 25, 30, 45 and 56 weeks of age in generation 18. In females, birds in the lean line laid more eggs from the first egg to 40 weeks of age than the birds in the fat line. In male broilers, the birds in the lean line had higher absolute and relative testicular weights at 7, 14 and 25 weeks of age, but lower absolute and relative testicular weights at 56 weeks of age than the birds in the fat line. Male birds in the lean line had greater sperm concentrations and larger numbers of motile and morphologically normal sperms at 30, 45 and 56 weeks of age than the birds in the fat line. Fertility and hatchability were also higher in the lean line than in the fat line. Significant differences in the plasma levels of reproductive hormones and the expression of reproduction-associated genes were also found at different ages in the lean and fat birds, in both males and females. These results suggest that reproductive performance is better in lean birds than in fat birds. In view of the unique divergent lines used in this study, these results imply that selecting for abdominal fat deposition negatively affects the reproductive performance of birds.

  14. Butterfly pollination in Pteroglossa (Orchidaceae, Orchidoideae): a comparative study on the reproductive biology of two species of a Neotropical genus of Spiranthinae.

    Science.gov (United States)

    Pansarin, Emerson R; Ferreira, Alessandro W C

    2015-05-01

    Spiranthinae orchids are known for being self-compatible and offering nectar as a reward. Although data on their pollinators are scarce, members of this tribe are mostly pollinated by bees, hummingbirds and moths. Some of them even reproduce through facultative self-pollination. Nothing is known about the pollinators and reproduction system in Pteroglossa. Based on records on flowering phenology, floral morphology, reward production, pollinators and breeding system, this paper aims to study the reproductive biology of two Pteroglossa spp. Both species offer nectar as a resource and are pollinated exclusively by diurnal Lepidoptera at the studied areas. Nectar is produced by two glandular nectaries, and is stored in a spur. Pollinaria possess a ventrally adhesive viscidium that is deposited on the basal portion of butterfly proboscides. Both species are self-compatible but pollinator-dependent. The reproductive success is low when compared to other Spiranthinae. Although no evident mechanical barrier to avoid self-pollination or geitonogamy was identified, the erratic behavior of the butterflies, with their infrequent visits to only one flower per inflorescence, contributes to an increased fruit set produced through cross-pollination. The presence of ventrally adhesive viscidia in Spiranthinae is responsible for greater pollinator diversity when compared to bee-pollinated Goodyerinae with dorsally adhesive viscidia, adapted to attach to bee mouthparts.

  15. Nutrient allocations and metabolism in two Collembola with contrasting reproduction and growth strategies

    DEFF Research Database (Denmark)

    Larsen, Thomas; Ventura, Marc; Damgaard, Christian

    2009-01-01

    1.  Physiological mechanisms such as allocation and release of nutrients are keys to understanding an animal's adaptation to a particular habitat. This study investigated how two detrivores with contrasting life-history traits allocated carbon (C) and nitrogen (N) to growth, reproduction and meta...

  16. Reproduction of two-spotted goby, Gobiusculus flavescens, in captivity

    Directory of Open Access Journals (Sweden)

    Vera Teles

    2014-06-01

    Full Text Available The two-spotted goby, Gobiusculus flavescens, is a common fish species along rocky shores in northern European waters. It is a small (40-60 mm, semipelagic marine fish, forming loose shoals in association with microalgae vegetation and mussel beds growing on the rock surface. It is a short-lived species, with a life span of 1-2 years. Both sexes display courtship behaviour and have sexual ornamentation during the breeding season. Male ornaments consist of large dorsal fins with iridescent blue lines, and iridescent blue spots along the sides of the body. Females develop a conspicuous, bright orange belly at sexual maturity. Due to these characteristics this species could have a great interest for ornamental aquariums. In previous work the maintenance of G. flavescens at high temperatures (until 23°C was successful. The aim of this study was to test the reproduction in captivity of G. flavescens. Six replicates were used (18L aquariums at the temperature of 18°C. In each replicate, two males and four females were introduced to an aquarium, where the males chose between two nests and courted the females. During the 112 days of the experiment the females spawned five times but only three spawns had success. The eggs take approximately 8 days to become mature. On the three spawns have hatched 300, 361 and 510 larvae at a time. The larvae were kept in a separate container and fed with alive rotifers and survived a maximum of 21 days. The reproduction of the two-spotted goby in captivity is possible at 18°C, but it is necessary to improve the conditions to rearing the larvae.

  17. Reproduction in the space environment: Part I. Animal reproductive studies

    Science.gov (United States)

    Santy, P. A.; Jennings, R. T.; Craigie, D.

    1990-01-01

    Mankind's exploration and colonization of the frontier of space will ultimately depend on men's and women's ability to live, work, and reproduce in the space environment. This paper reviews animal studies, from microorganisms to mammals, done in space or under space-simulated conditions, which identify some of the key areas which might interfere with human reproductive physiology and/or embryonic development. Those space environmental factors which impacted almost all species included: microgravity, artificial gravity, radiation, and closed life support systems. These factors may act independently and in combination to produce their effects. To date, there have been no studies which have looked at the entire process of reproduction in any animal species. This type of investigation will be critical in understanding and preventing the problems which will affect human reproduction. Part II will discuss these problems directly as they relate to human physiology.

  18. DNA alterations and effects on growth and reproduction in Daphnia magna during chronic exposure to gamma radiation over three successive generations

    International Nuclear Information System (INIS)

    Parisot, Florian; Bourdineaud, Jean-Paul; Plaire, Delphine; Adam-Guillermin, Christelle; Alonzo, Frédéric

    2015-01-01

    Highlights: • We exposed three successive generations of Daphnia magna to chronic gamma radiation. • We examined DNA alterations and effects on survival, growth and reproduction. • DNA alterations were accumulated over a generation and transmitted to the progeny. • Effects on survival and reproduction, and delay in growth increased over generations. - Abstract: This study examined chronic effects of external Cs-137 gamma radiation on Daphnia magna exposed over three successive generations (F0, F1 and F2) to environmentally relevant dose rates (ranging from 0.007 to 35.4 mGy h −1 ). Investigated endpoints included survival, growth, reproduction and DNA alterations quantified using random-amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). Results demonstrated that radiation effects on survival, growth and reproduction increased in severity from generation F0 to generation F2. Mortality after 21 days at 35.4 mGy h −1 increased from 20% in F0 to 30% in F2. Growth was affected by a slight reduction in maximum length at 35.4 mGy h −1 in F0 and by reductions of 5 and 13% in growth rate, respectively, at 4.70 and 35.4 mGy h −1 in F2. Reproduction was affected by a reduction of 19% in 21 day-fecundity at 35.4 mGy h −1 in F0 and by a delay of 1.9 days in brood release as low as 0.070 mGy h −1 in F2. In parallel, DNA alterations became significant at decreasing dose rates over the course of F0 (from 4.70 mGy h −1 at hatching to 0.007 mGy h −1 after ∼21 days) and from F0 to F2 (0.070 mGy h −1 at hatching to 0.007 mGy h −1 after ∼21 days), demonstrating their rapid accumulation in F0 daphnids and their transmission to offspring generations. Transiently more efficient DNA repair leading to some recovery at the organism level was suggested in F1, with no effect on survival, a slight reduction of 12% in 21 day-fecundity at 35.4 mGy h −1 and DNA alterations significant at highest dose rates only. The study improved our understanding of

  19. DNA alterations and effects on growth and reproduction in Daphnia magna during chronic exposure to gamma radiation over three successive generations

    Energy Technology Data Exchange (ETDEWEB)

    Parisot, Florian [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, St Paul-lez-Durance 13115 (France); Bourdineaud, Jean-Paul [UMR 5805 EPOC – OASU, Station marine d’Arcachon, Université Bordeaux 1, Arcachon 33120 (France); Plaire, Delphine; Adam-Guillermin, Christelle [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, St Paul-lez-Durance 13115 (France); Alonzo, Frédéric, E-mail: frederic.alonzo@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, St Paul-lez-Durance 13115 (France)

    2015-06-15

    Highlights: • We exposed three successive generations of Daphnia magna to chronic gamma radiation. • We examined DNA alterations and effects on survival, growth and reproduction. • DNA alterations were accumulated over a generation and transmitted to the progeny. • Effects on survival and reproduction, and delay in growth increased over generations. - Abstract: This study examined chronic effects of external Cs-137 gamma radiation on Daphnia magna exposed over three successive generations (F0, F1 and F2) to environmentally relevant dose rates (ranging from 0.007 to 35.4 mGy h{sup −1}). Investigated endpoints included survival, growth, reproduction and DNA alterations quantified using random-amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). Results demonstrated that radiation effects on survival, growth and reproduction increased in severity from generation F0 to generation F2. Mortality after 21 days at 35.4 mGy h{sup −1} increased from 20% in F0 to 30% in F2. Growth was affected by a slight reduction in maximum length at 35.4 mGy h{sup −1} in F0 and by reductions of 5 and 13% in growth rate, respectively, at 4.70 and 35.4 mGy h{sup −1} in F2. Reproduction was affected by a reduction of 19% in 21 day-fecundity at 35.4 mGy h{sup −1} in F0 and by a delay of 1.9 days in brood release as low as 0.070 mGy h{sup −1} in F2. In parallel, DNA alterations became significant at decreasing dose rates over the course of F0 (from 4.70 mGy h{sup −1} at hatching to 0.007 mGy h{sup −1} after ∼21 days) and from F0 to F2 (0.070 mGy h{sup −1} at hatching to 0.007 mGy h{sup −1} after ∼21 days), demonstrating their rapid accumulation in F0 daphnids and their transmission to offspring generations. Transiently more efficient DNA repair leading to some recovery at the organism level was suggested in F1, with no effect on survival, a slight reduction of 12% in 21 day-fecundity at 35.4 mGy h{sup −1} and DNA alterations significant at highest

  20. A hybrid computational method for the discovery of novel reproduction-related genes.

    Science.gov (United States)

    Chen, Lei; Chu, Chen; Kong, Xiangyin; Huang, Guohua; Huang, Tao; Cai, Yu-Dong

    2015-01-01

    Uncovering the molecular mechanisms underlying reproduction is of great importance to infertility treatment and to the generation of healthy offspring. In this study, we discovered novel reproduction-related genes with a hybrid computational method, integrating three different types of method, which offered new clues for further reproduction research. This method was first executed on a weighted graph, constructed based on known protein-protein interactions, to search the shortest paths connecting any two known reproduction-related genes. Genes occurring in these paths were deemed to have a special relationship with reproduction. These newly discovered genes were filtered with a randomization test. Then, the remaining genes were further selected according to their associations with known reproduction-related genes measured by protein-protein interaction score and alignment score obtained by BLAST. The in-depth analysis of the high confidence novel reproduction genes revealed hidden mechanisms of reproduction and provided guidelines for further experimental validations.

  1. Two-generation reproductive toxicity study of plant stanol esters in rats

    NARCIS (Netherlands)

    Whittaker, M.H.; Frankos, V.H.; Wolterbeek, A.P.M.; Waalkens-Berendsen, D.H.

    1999-01-01

    Plant stanol esters are intended for use as an ingredient in food to reduce the absorption of cholesterol from the gastrointestinal tract. Consumption of plant stanol esters has a demonstrated diet-derived public health benefit, as shown by numerous clinical studies. Plant stanol esters are

  2. The genetics of reproductive organ morphology in two Petunia species with contrasting pollination syndromes.

    Science.gov (United States)

    Hermann, Katrin; Klahre, Ulrich; Venail, Julien; Brandenburg, Anna; Kuhlemeier, Cris

    2015-05-01

    Switches between pollination syndromes have happened frequently during angiosperm evolution. Using QTL mapping and reciprocal introgressions, we show that changes in reproductive organ morphology have a simple genetic basis. In animal-pollinated plants, flowers have evolved to optimize pollination efficiency by different pollinator guilds and hence reproductive success. The two Petunia species, P. axillaris and P. exserta, display pollination syndromes adapted to moth or hummingbird pollination. For the floral traits color and scent, genetic loci of large phenotypic effect have been well documented. However, such large-effect loci may be typical for shifts in simple biochemical traits, whereas the evolution of morphological traits may involve multiple mutations of small phenotypic effect. Here, we performed a quantitative trait locus (QTL) analysis of floral morphology, followed by an in-depth study of pistil and stamen morphology and the introgression of individual QTL into reciprocal parental backgrounds. Two QTLs, on chromosomes II and V, are sufficient to explain the interspecific difference in pistil and stamen length. Since most of the difference in organ length is caused by differences in cell number, genes underlying these QTLs are likely to be involved in cell cycle regulation. Interestingly, conservation of the locus on chromosome II in a different P. axillaris subspecies suggests that the evolution of organ elongation was initiated on chromosome II in adaptation to different pollinators. We recently showed that QTLs for pistil and stamen length on chromosome II are tightly linked to QTLs for petal color and volatile emission. Linkage of multiple traits will enable major phenotypic change within a few generations in hybridizing populations. Thus, the genomic architecture of pollination syndromes in Petunia allows for rapid responses to changing pollinator availability.

  3. Lizard reproductive medicine and surgery.

    Science.gov (United States)

    Funk, Richard S

    2002-09-01

    Lizards are a diverse group of some 4470 species, a wide variety of which are now kept in captivity. Interest in captive lizards continues to increase, wild populations seem to be declining in some areas, and herpetoculturists continue to succeed in breeding more species; consequently, veterinarians must understand basic lizard reproductive biology to successfully treat lizard patients with reproductive problems. Just obtaining First Filial Generation (F1) offspring is an accomplishment. But we must look down the road to maintain a species in captivity for succeeding generations, and a lineage may not continue if attention is not given to details of appropriate husbandry and proper reproductive pursuits. One study documents the senescence of lineages in parthenogenetic lizards in captivity apparently associated with husbandry problems [99].

  4. Effects of phytosterols on zebrafish reproduction in multigeneration test

    International Nuclear Information System (INIS)

    Nakari, Tarja; Erkomaa, Kirsti

    2003-01-01

    A multigeneration test is used to show disruption of the reproductive system by phytosterols. - Zebrafish from mixed sex populations were exposed continuously across three generations to two phytosterol preparations both containing β-sitosterol. The phytosterols were isolated from wood and soy beans. Blood vitellogenin levels and sex ratio changes were used as intermediate indicators of the reproduction failures. Both sterol preparations caused vitellogenin induction in the exposed fish. The wood sterol changed the sex ratio of the exposed fish. In generation F1, the predominant sex was male, and in generation F2 it was female. The soy sterol in the used test concentration was lethal to the exposed fish in generation F1. This multigeneration test evidenced that phytosterols containing β-sitosterol disrupt the reproduction system of zebrafish by changing the sex ratios and by inducing the vitellogenin production in the exposed fish

  5. Effects of phytosterols on zebrafish reproduction in multigeneration test

    Energy Technology Data Exchange (ETDEWEB)

    Nakari, Tarja; Erkomaa, Kirsti

    2003-05-01

    A multigeneration test is used to show disruption of the reproductive system by phytosterols. - Zebrafish from mixed sex populations were exposed continuously across three generations to two phytosterol preparations both containing {beta}-sitosterol. The phytosterols were isolated from wood and soy beans. Blood vitellogenin levels and sex ratio changes were used as intermediate indicators of the reproduction failures. Both sterol preparations caused vitellogenin induction in the exposed fish. The wood sterol changed the sex ratio of the exposed fish. In generation F1, the predominant sex was male, and in generation F2 it was female. The soy sterol in the used test concentration was lethal to the exposed fish in generation F1. This multigeneration test evidenced that phytosterols containing {beta}-sitosterol disrupt the reproduction system of zebrafish by changing the sex ratios and by inducing the vitellogenin production in the exposed fish.

  6. Natural hybridization and reproductive isolation between two Primula speciesFA

    Institute of Scientific and Technical Information of China (English)

    Yanping Xie; Xingfu Zhu; Yongpeng Ma; Jianli Zhao; Li Li; Qingjun Li

    2017-01-01

    Natural hybridization frequently occurs in plants and can facilitate gene flow between species,possibly resulting in species refusion.However,various reproductive barriers block the formation of hybrids and maintain species integrity.Here,we conducted a field survey to examine natural hybridization and reproductive isolation (RI) between sympatric populations of Primula secundiflora and P.poissonii using ten nuclear simple sequence repeat (SSR) loci.Although introgressive hybridization occurred,species boundaries between P.secundiflora and P.poissonii were maintained through nearly complete reproductive isolation.These interfertile species provide an excellent model for studying the RI mechanisms and evolutionary forces that maintain species boundaries.

  7. Assisted Reproductive Technology Has No Association with Autism Spectrum Disorders: The Taiwan Birth Cohort Study

    Science.gov (United States)

    Lung, For-Wey; Chiang, Tung-Liang; Lin, Shio-Jean; Lee, Meng-Chih; Shu, Bih-Ching

    2018-01-01

    The use of assisted reproduction technology has increased over the last two decades. Autism spectrum disorders and assisted reproduction technology share many risk factors. However, previous studies on the association between autism spectrum disorders and assisted reproduction technology have shown inconsistent results. The purpose of this study…

  8. Reproductive Plasticity of an Invasive Insect Pest, Rice Water Weevil (Coleoptera: Curculionidae).

    Science.gov (United States)

    Huang, Yunshang; Ao, Yan; Jiang, Mingxing

    2017-12-05

    Reproductive plasticity is a key determinant of species invasiveness. However, there are a limited number of studies addressing this issue in exotic insects. The rice water weevil Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae), which is native to North America, is one of the most invasive insect pests in east Asia. In this study, we investigated the reproductive status of first-generation females (progeny of overwintered weevils) from five geographic regions in southern and northern China in the field, and reproductive status and ovipositional features of females provided with suitable host plants in the laboratory after collection. Under field conditions, a proportion of females oviposited, while the rest remained in diapause from all three southern regions investigated, but reproductive development did not take place in females from the two northern regions, where the weevil produces only one generation per year. However, when fed host plants in the laboratory, females from all regions laid eggs. They typically had a very short ovipositional period (3-6 d on average on rice at a temperature of 27°C), laid a low number of eggs, and did not die soon after oviposition; this was different from common reproductive females. We concluded that first-generation L. oryzophilus females, which largely enter diapause after emergence, are highly plastic in their reproductive performance and are ready to reproduce under favorable conditions. Our results indicate the significance of their reproductive plasticity for geographic spread and population development. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. First evidence for postzygotic reproductive isolation between two populations of Eurasian perch (Perca fluviatilis L. within Lake Constance

    Directory of Open Access Journals (Sweden)

    Gerlach Gabriele

    2008-01-01

    Full Text Available Abstract Background The evolution of reproductive traits, such as hybrid incompatibility (postzygotic isolation and species recognition (prezygotic isolation, have shown their key role in speciation. Theoretical modeling has recently predicted that close linkage between genes controlling pre- and postzygotic reproductive isolation could accelerate the conditions for speciation. Postzygotic isolation could develop during the sympatric speciation process contributing to the divergence of populations. Using hybrid fitness as a measure of postzygotic reproductive isolation, we empirically studied population divergence in perch (Perca fluviatilis L. from two genetically divergent populations within a lake. Results During spawning time of perch we artificially created parental offspring and F1 hybrids of the two populations and studied fertilization rate and hatching success under laboratory conditions. The combined fitness measure (product of fertilization rate and hatching success of F1 hybrids was significantly reduced compared to offspring from within population crosses. Conclusion Our results suggest intrinsic genetic incompatibility between the two populations and indicate that population divergence between two populations of perch inhabiting the same lake may indeed be promoted by postzygotic isolation.

  10. Effects of cadmium on life-cycle parameters in a multi-generation study with Chironomus riparius following a pre-exposure of populations to two different tributyltin concentrations for several generations.

    Science.gov (United States)

    Vogt, Christian; Hess, Maren; Nowak, Carsten; Diogo, João Barateiro; Oehlmann, Jörg; Oetken, Matthias

    2010-10-01

    So far only a few studies have been performed to assess the effects of dynamic pollutant exposure on life-history parameters of invertebrates. In a previous multi-generation approach with the midge Chironomus riparius we tested if a chronic tributyltin pre-exposure alters the ability of a population to cope with subsequent cadmium stress. In the experiment two separate chironomid populations were exposed via sediments to different TBT-concentrations (4.46 and 8.93 μg Sn/kg dw) for several generations, followed by subsequent cadmium exposure (1.2 mg Cd/kg dw) for three generations. While the TBT-exposure to 4.46 μg Sn/kg dw had only small effects on the development and reproduction of C. riparius the higher TBT-concentration of 8.93 μg Sn/kg dw led to negative effects on life-history traits. Therefore, a higher adverse effect of the higher TBT-concentration and thus a higher susceptibility to other stressors could be assumed. Within, this paper only the results of the second stressor experiment were presented; clear effects of Cd on development and reproduction of C. riparius were determined independent of the pre-exposure scenario. While no differences in Cd-sensitivity were found between the population without pre-exposure to TBT and the population pre-exposed to the low TBT-concentration (4.46 μg Sn/kg dw), the pre-exposure of midges to the higher TBT-concentration (8.93 μg Sn/kg dw) resulted in a significantly higher susceptibility to subsequent Cd-stress. These results document that the exposure history may influence the reaction to altered chemical stress. Our findings are relevant to understand and predict the evolutionary fate of populations in rapidly changing, human-impacted environments. However, the fact that chemical-induced reduced genetic diversity, which is not necessarily linked to genetic adaptation, leads to a reduced fitness under altered stress conditions, is to our knowledge a novel finding.

  11. Genetic Linkage Map Construction and QTL Analysis of Two Interspecific Reproductive Isolation Traits in Sponge Gourd

    OpenAIRE

    Wu, Haibin; He, Xiaoli; Gong, Hao; Luo, Shaobo; Li, Mingzhu; Chen, Junqiu; Zhang, Changyuan; Yu, Ting; Huang, Wangping; Luo, Jianning

    2016-01-01

    The hybrids between Luffa acutangula (L.) Roxb. and L.cylindrica (L.) Roem. have strong heterosis effects. However, some reproductive isolation traits hindered their normal hybridization and fructification, which was mainly caused by the flowering time and hybrid pollen sterility. In order to study the genetic basis of two interspecific reproductive isolation traits, we constructed a genetic linkage map using an F2 population derived from a cross between S1174 [L. acutangula (L.) Roxb.] and 9...

  12. Genetic Linkage Map Construction and QTL Analysis of Two Interspecific Reproductive Isolation Traits in Sponge Gourd.

    Science.gov (United States)

    Wu, Haibin; He, Xiaoli; Gong, Hao; Luo, Shaobo; Li, Mingzhu; Chen, Junqiu; Zhang, Changyuan; Yu, Ting; Huang, Wangping; Luo, Jianning

    2016-01-01

    The hybrids between Luffa acutangula (L.) Roxb. and L.cylindrica (L.) Roem. have strong heterosis effects. However, some reproductive isolation traits hindered their normal hybridization and fructification, which was mainly caused by the flowering time and hybrid pollen sterility. In order to study the genetic basis of two interspecific reproductive isolation traits, we constructed a genetic linkage map using an F2 population derived from a cross between S1174 [L. acutangula (L.) Roxb.] and 93075 [L. cylindrica (L.) Roem.]. The map spans 1436.12 CentiMorgans (cM), with an average of 8.11 cM among markers, and consists of 177 EST-SSR markers distributed in 14 linkage groups (LG) with an average of 102.58 cM per LG. Meanwhile, we conducted colinearity analysis between the sequences of EST-SSR markers and the genomic sequences of cucumber, melon and watermelon. On the basis of genetic linkage map, we conducted QTL mapping of two reproductive isolation traits in sponge gourd, which were the flowering time and hybrid male sterility. Two putative QTLs associated with flowering time (FT) were both detected on LG 1. The accumulated contribution of these two QTLs explained 38.07% of the total phenotypic variance (PV), and each QTL explained 15.36 and 22.71% of the PV respectively. Four QTLs for pollen fertility (PF) were identified on LG 1 (qPF1.1 and qPF1.2), LG 3 (qPF3) and LG 7 (qPF7), respectively. The percentage of PF explained by these QTLs varied from 2.91 to 16.79%, and all together the four QTLs accounted for 39.98% of the total PV. Our newly developed EST-SSR markers and linkage map are very useful for gene mapping, comparative genomics and molecular marker-assisted breeding. These QTLs for interspecific reproductive isolation will also contribute to the cloning of genes relating to interspecific reproductive isolation and the utilization of interspecific heterosis in sponge gourd in further studies.

  13. Reproductive Effects of Two Polybrominated Diphenyl Ethers on the Rotifer Brachionus plicatilis.

    Science.gov (United States)

    Zhang, Jing; Wang, You; Zhou, Bin; Sun, Kai-Ming; Tang, Xuexi

    2016-08-01

    The effects of two polybrominated diphenyl ethers (PBDEs) on the reproduction of the rotifer Brachionus plicatilis were investigated. Results showed that sexual maturation was promoted by tetra-brominated diphenyl ether-47 (BDE-47) and deca-brominated diphenyl ether-209 (BDE-209), whereas fecundity was inhibited by BDE-47, but promoted by BDE-209. Additionally, both PBDEs affected the expression of two genes, vasa and nanos mRNA, related to rotifer reproduction. This suggests a possible regulatory molecular mechanism at the transcriptional level. Our research extends the current knowledge of the ecotoxicological mechanism induced by PBDEs and provides further essential information for assessing the risks of PBDE contamination in marine ecosystems.

  14. A theoretical study of the energy output of two magnetohydrodynamic generators

    International Nuclear Information System (INIS)

    Vergnes, Jean

    1975-01-01

    The outputs of two alternating-current generators consisting of rectangular conduits which contain an electroconducting viscous fluid and are subjected to a uniform magnetic induction field are compared. This study supposes that the electric circuit is closed by a resistance R [fr

  15. Obsessive-compulsive disorder and female reproductive cycle events: results from the OCD and reproduction collaborative study.

    Science.gov (United States)

    Guglielmi, Valeria; Vulink, Nienke C C; Denys, Damiaan; Wang, Ying; Samuels, Jack F; Nestadt, Gerald

    2014-12-01

    Women with obsessive-compulsive disorder (OCD) often report that symptoms first appear or exacerbate during reproductive cycle events; however, little is known about these relationships. The goals of this study were to examine, in a US and a European female OCD sample, onset and exacerbation of OCD in reproductive cycle events, and to investigate the likelihood of repeat exacerbation in subsequent pregnancies and postpartum periods. Five hundred forty-two women (United States, n = 352; Dutch, n = 190) who met DSM-IV criteria for OCD, completed self-report questionnaires designed to assess OCD onset and symptom exacerbation associated with reproductive events. OCD onset occurred within 12 months after menarche in 13.0%, during pregnancy in 5.1%, at postpartum in 4.7%, and at menopause in 3.7%. Worsening of pre-existing OCD was reported by 37.6% of women at premenstruum, 33.0% during pregnancy, 46.6% postpartum, and 32.7% at menopause. Exacerbation in first pregnancy was significantly associated with exacerbation in second pregnancy (OR = 10.82, 95% CI 4.48-26.16), as was exacerbation in first postpartum with exacerbation in second postpartum (OR = 6.86, 95% CI 3.27-14.36). Results were replicated in both samples. Reproductive cycle events are periods of increased risk for onset and exacerbation of OCD in women. The present study is the first to provide significant evidence that exacerbation in or after first pregnancy is a substantial risk factor for exacerbation in or after a subsequent pregnancy. Further research is needed to identify factors related to exacerbation, so that physicians may provide appropriate recommendations to women regarding clinical issues involving OCD and reproductive cycle events. © 2014 Wiley Periodicals, Inc.

  16. Rise and fall: two sides of a coin of middle aged women's perceptions of reproductive: a qualitative study.

    Science.gov (United States)

    Reyhani, Mitra; Kazemi, Ashraf; Keshvari, Mahrokh

    2018-02-02

    The present study was conducted to determine the perceptions of middle-aged women of reproductive changes. The present study was a qualitative research with a content analysis approach. The participants were 30 middle-aged women whose perceptions of reproductive changes had been collected on in-depth semi-structured interviews. The data were analyzed using the Graneheim and Lundman's inductive content analysis method. The main themes extracted from the data were a sense of "fall" and "the beginning of a new life cycle." A feeling of fall was formed from the subthemes "deterioration of youth," "the dusk of femininity," and "fade-out of the gender roles." The theme "beginning of a new life cycle" was formed from the subthemes of "acceptance," "sophistication," and "maturity." Middle-aged women had a wide range of emotions experienced from the reproductive changes ranging from a feeling of decline to that of excellence and rise.

  17. Reproductive performance of artificially inseminated dairy cows ...

    African Journals Online (AJOL)

    The objectives of the study were to generate a reliable field data set and analyze it to determine reproductive parameters/indices. A total of 280 and 400 households keeping 158 and 709 cows and heifers in Rwanda and Tanzania respectively were studied. Reproductive events: dates of heat, AI or NS, service number, sire ...

  18. Multigeneration reproduction and male developmental toxicity studies on atrazine in rats.

    Science.gov (United States)

    DeSesso, John M; Scialli, Anthony R; White, Tacey E K; Breckenridge, Charles B

    2014-06-01

    Reproductive toxicity of Atrazine (ATR) was evaluated in two rat multigenerational studies. Development of male reproductive parameters was evaluated in separate studies after prenatal or postnatal exposure. In multigenerational studies, rats received dietary concentrations of 0, 10, 50, 100 or 500 ppm ATR. In separate studies in female rats, ATR was administered by gavage at 0, 1, 5, 25 or 125 mg/kg/day during pregnancy (GD6-21) or lactation (LD2-21). Plasma testosterone concentration, testicular and epididymal weights, and sperm counts were measured in male offspring on PND70 and 170. In the multigenerational studies, parental systemic toxicity occurred at 500 ppm (38.7 mg/kg/day), but reproductive endpoints were unaffected. In the prenatal study, maternal toxicity and embryo-fetal mortality occurred at 125 mg/kg/day. In male offspring, testosterone levels and sperm counts were unaffected, although the percentage of abnormal sperm increased at 125 mg/kg/day (PND 70) and 25 mg/kg/day (PND170). In the postnatal study, maternal toxicity and reduced body weights of male offspring occurred at 125 mg/kg/day. Additionally, reduced testicular (PND70, PND170) and epididymal (PND70) weights and increased numbers of abnormal sperm (PND70, PND170) were seen, but no changes in plasma testosterone or sperm counts. Dietary administration of ATR did not affect rat reproduction up to a parentally toxic dose of 38.7 mg/kg/day. Some effects on male reproductive system development occurred after high dose, bolus administration to dams, but doses were much higher than expected under normal use conditions. Thus, oral RfDs for ATR would be protective for reproductive effects. © 2014 Wiley Periodicals, Inc.

  19. Effects of depleted uranium on the reproductive success and F1 generation survival of zebrafish (Danio rerio)

    Energy Technology Data Exchange (ETDEWEB)

    Bourrachot, Stéphanie [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France); Brion, François [Institut National de l’Environnement Industriel et des Risques (INERIS), Unité d’évaluation des risques écotoxicologiques, BP2, 60550 Verneuil-en-Halatte (France); Pereira, Sandrine; Floriani, Magali; Camilleri, Virginie; Cavalié, Isabelle [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France); Palluel, Olivier [Institut National de l’Environnement Industriel et des Risques (INERIS), Unité d’évaluation des risques écotoxicologiques, BP2, 60550 Verneuil-en-Halatte (France); Adam-Guillermin, Christelle, E-mail: christelle.adam-guillermin@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France)

    2014-09-15

    Highlights: • The effect of depleted uranium on zebrafish reproduction was studied. • An inhibition of egg production and an increase of F1 embryo mortality were observed. • Decreased circulating concentration of vitellogenin was observed in females. • Increased DNA damages were observed in parent gonads and in embryos. • U environmental concentration impairs reproduction and genetic integrity of fish. - Abstract: Despite the well-characterized occurrence of uranium (U) in the aquatic environment, very little is known about the chronic exposure of fish to low levels of U and its potential effect on reproduction. Therefore, this study was undertaken to investigate the effects of environmental concentrations of depleted U on the reproductive output of zebrafish (Danio rerio) and on survival and development of the F1 embryo-larvae following parental exposure to U. For that purpose, sexually mature male and female zebrafish were exposed to 20 and 250 μg/L of U for 14 days and allowed to reproduce in clean water during a further 14-day period. At all sampling times, whole-body vitellogenin concentrations and gonad histology were analyzed to investigate the effects of U exposure on these reproductive endpoints. In addition, accumulation of U in the gonads and its genotoxic effect on male and female gonad cells were quantified. The results showed that U strongly affected the capability of fish to reproduce and to generate viable individuals as evidenced by the inhibition of egg production and the increased rate of mortality of the F1 embryos. Interestingly, U exposure resulted in decreased circulating concentrations of vitellogenin in females. Increased concentrations of U were observed in gonads and eggs, which were most likely responsible for the genotoxic effects seen in fish gonads and in embryos exposed maternally to U. Altogether, these findings highlight the negative effect of environmentally relevant concentrations of U which alter the reproductive

  20. Effects of depleted uranium on the reproductive success and F1 generation survival of zebrafish (Danio rerio)

    International Nuclear Information System (INIS)

    Bourrachot, Stéphanie; Brion, François; Pereira, Sandrine; Floriani, Magali; Camilleri, Virginie; Cavalié, Isabelle; Palluel, Olivier; Adam-Guillermin, Christelle

    2014-01-01

    Highlights: • The effect of depleted uranium on zebrafish reproduction was studied. • An inhibition of egg production and an increase of F1 embryo mortality were observed. • Decreased circulating concentration of vitellogenin was observed in females. • Increased DNA damages were observed in parent gonads and in embryos. • U environmental concentration impairs reproduction and genetic integrity of fish. - Abstract: Despite the well-characterized occurrence of uranium (U) in the aquatic environment, very little is known about the chronic exposure of fish to low levels of U and its potential effect on reproduction. Therefore, this study was undertaken to investigate the effects of environmental concentrations of depleted U on the reproductive output of zebrafish (Danio rerio) and on survival and development of the F1 embryo-larvae following parental exposure to U. For that purpose, sexually mature male and female zebrafish were exposed to 20 and 250 μg/L of U for 14 days and allowed to reproduce in clean water during a further 14-day period. At all sampling times, whole-body vitellogenin concentrations and gonad histology were analyzed to investigate the effects of U exposure on these reproductive endpoints. In addition, accumulation of U in the gonads and its genotoxic effect on male and female gonad cells were quantified. The results showed that U strongly affected the capability of fish to reproduce and to generate viable individuals as evidenced by the inhibition of egg production and the increased rate of mortality of the F1 embryos. Interestingly, U exposure resulted in decreased circulating concentrations of vitellogenin in females. Increased concentrations of U were observed in gonads and eggs, which were most likely responsible for the genotoxic effects seen in fish gonads and in embryos exposed maternally to U. Altogether, these findings highlight the negative effect of environmentally relevant concentrations of U which alter the reproductive

  1. Assisted reproductive technology has no association with autism spectrum disorders: The Taiwan Birth Cohort Study.

    Science.gov (United States)

    Lung, For-Wey; Chiang, Tung-Liang; Lin, Shio-Jean; Lee, Meng-Chih; Shu, Bih-Ching

    2018-04-01

    The use of assisted reproduction technology has increased over the last two decades. Autism spectrum disorders and assisted reproduction technology share many risk factors. However, previous studies on the association between autism spectrum disorders and assisted reproduction technology have shown inconsistent results. The purpose of this study was to investigate the association between assisted reproduction technology and autism spectrum disorder diagnosis in a national birth cohort database. Furthermore, the results from the assisted reproduction technology and autism spectrum disorder propensity score matching exact matched datasets were compared. For this study, the 6- and 66-month Taiwan Birth Cohort Study datasets were used (N = 20,095). In all, 744 families were propensity score matching exact matched and selected as the assisted reproduction technology sample (ratio of assisted reproduction technology to controls: 1:2) and 415 families as the autism spectrum disorder sample (ratio of autism spectrum disorder to controls: 1:4). Using a national birth cohort dataset, controlling for the confounding factors of assisted reproduction technology conception and autism spectrum disorder diagnosis, both assisted reproduction technology and autism spectrum disorder propensity score matching matched datasets showed the same results of no association between assisted reproduction technology and autism spectrum disorder. Further study on the detailed information regarding the processes and methods of assisted reproduction technology may provide us with more information on the association between assisted reproduction technology and autism spectrum disorder.

  2. Floral traits driving reproductive isolation of two co-flowering taxa that share vertebrate pollinators

    Science.gov (United States)

    Queiroz, Joel A.; Quirino, Zelma G. M.; Machado, Isabel C.

    2015-01-01

    Floral attributes evolve in response to frequent and efficient pollinators, which are potentially important drivers of floral diversification and reproductive isolation. In this context, we asked, how do flowers evolve in a bat–hummingbird pollination system? Hence, we investigated the pollination ecology of two co-flowering Ipomoea taxa (I. marcellia and I. aff. marcellia) pollinated by bats and hummingbirds, and factors favouring reproductive isolation and pollinator sharing in these plants. To identify the most important drivers of reproductive isolation, we compared the flowers of the two Ipomoea taxa in terms of morphometry, anthesis and nectar production. Pollinator services were assessed using frequency of visits, fruit set and the number of seeds per fruit after visits. The studied Ipomoea taxa differed in corolla size and width, beginning and duration of anthesis, and nectar attributes. However, they shared the same diurnal and nocturnal visitors. The hummingbird Heliomaster squamosus was more frequent in I. marcellia (1.90 visits h−1) than in I. aff. marcellia (0.57 visits h−1), whereas glossophagine bats showed similar visit rates in both taxa (I. marcellia: 0.57 visits h−1 and I. aff. marcellia: 0.64 visits h−1). Bat pollination was more efficient in I. aff. marcellia, whereas pollination by hummingbirds was more efficient in I. marcellia. Differences in floral attributes between Ipomoea taxa, especially related to the anthesis period, length of floral parts and floral arrangement in the inflorescence, favour reproductive isolation from congeners through differential pollen placement on pollinators. This bat–hummingbird pollination system seems to be advantageous in the study area, where the availability of pollinators and floral resources changes considerably throughout the year, mainly as a result of rainfall seasonality. This interaction is beneficial for both sides, as it maximizes the number of potential pollen vectors for plants and

  3. Genetic dissection of a key reproductive barrier between nascent species of house mice.

    Science.gov (United States)

    White, Michael A; Steffy, Brian; Wiltshire, Tim; Payseur, Bret A

    2011-09-01

    Reproductive isolation between species is often caused by deleterious interactions among loci in hybrids. Finding the genes involved in these incompatibilities provides insight into the mechanisms of speciation. With recently diverged subspecies, house mice provide a powerful system for understanding the genetics of reproductive isolation early in the speciation process. Although previous studies have yielded important clues about the genetics of hybrid male sterility in house mice, they have been restricted to F1 sterility or incompatibilities involving the X chromosome. To provide a more complete characterization of this key reproductive barrier, we conducted an F2 intercross between wild-derived inbred strains from two subspecies of house mice, Mus musculus musculus and Mus musculus domesticus. We identified a suite of autosomal and X-linked QTL that underlie measures of hybrid male sterility, including testis weight, sperm density, and sperm morphology. In many cases, the autosomal loci were unique to a specific sterility trait and exhibited an effect only when homozygous, underscoring the importance of examining reproductive barriers beyond the F1 generation. We also found novel two-locus incompatibilities between the M. m. musculus X chromosome and M. m. domesticus autosomal alleles. Our results reveal a complex genetic architecture for hybrid male sterility and suggest a prominent role for reproductive barriers in advanced generations in maintaining subspecies integrity in house mice.

  4. Genetic Dissection of a Key Reproductive Barrier Between Nascent Species of House Mice

    Science.gov (United States)

    White, Michael A.; Steffy, Brian; Wiltshire, Tim; Payseur, Bret A.

    2011-01-01

    Reproductive isolation between species is often caused by deleterious interactions among loci in hybrids. Finding the genes involved in these incompatibilities provides insight into the mechanisms of speciation. With recently diverged subspecies, house mice provide a powerful system for understanding the genetics of reproductive isolation early in the speciation process. Although previous studies have yielded important clues about the genetics of hybrid male sterility in house mice, they have been restricted to F1 sterility or incompatibilities involving the X chromosome. To provide a more complete characterization of this key reproductive barrier, we conducted an F2 intercross between wild-derived inbred strains from two subspecies of house mice, Mus musculus musculus and Mus musculus domesticus. We identified a suite of autosomal and X-linked QTL that underlie measures of hybrid male sterility, including testis weight, sperm density, and sperm morphology. In many cases, the autosomal loci were unique to a specific sterility trait and exhibited an effect only when homozygous, underscoring the importance of examining reproductive barriers beyond the F1 generation. We also found novel two-locus incompatibilities between the M. m. musculus X chromosome and M. m. domesticus autosomal alleles. Our results reveal a complex genetic architecture for hybrid male sterility and suggest a prominent role for reproductive barriers in advanced generations in maintaining subspecies integrity in house mice. PMID:21750261

  5. Managing patients with concerns about workplace reproductive hazards.

    Science.gov (United States)

    Frazier, L M; Jones, T L

    2000-01-01

    To find out who uses an occupational reproductive consultation service, what proportion of patients have different types of workplace exposures, and what hypotheses can be generated about barriers to implementing medically necessary job modifications to promote reproductive health. A case series study was conducted by reviewing medical records at two occupational health clinics. 51 patients (1 man and 50 women) were seen, 10 of whom wished to discuss a future pregnancy and 41 of whom were pregnant. Pregnant women worked with a mean of 15.5 different chemicals, and patients were also concerned about ionizing radiation, biological hazards, electromagnetic fields, and ultraviolet light. Pregnant women made clinic visits at a mean gestational age of 10.9 weeks. Only one man used the service, suggesting a lack of knowledge about possible paternal contributions to adverse reproductive outcomes. Many pregnant women visited the clinic too late to prevent harm from exposure to some teratogens, so preconception counseling may be of benefit. Cases are presented that illustrate ways in which the primary care provider can assist the patient who may be exposed to reproductive hazards.

  6. Educational needs of reproductive health students: A Delphi study

    OpenAIRE

    N Yamani; M Shakour; S Ehsanpour

    2013-01-01

    Introduction: The importance of reproductive health led to establish the MSc in reproductive health program in developed country. In Iran, the program has not been offered yet. The aim of this study was to assess educational needs of MSc program in reproductive health. Methods: This research used Delphi method. Fifteen experts in reproductive health from Iran participated in this study. First, we provided a list of educational needs for every task, then experts confirmed or rejected education...

  7. Comparison of menarche age between two generations (tehran lipid and glucose study)

    International Nuclear Information System (INIS)

    Ainy, E.; Aziz, F.

    2007-01-01

    Menarcheal age is considered to be an indicator of puberty. There is a lack of information on menarcheal age in Tehranian girls, in comparison to that of their mothers. This cross-sectional study was aimed at comparing the age of menarches between two generations. The subjects were 812 (406 daughters and 406 mothers) chosen from among 15005 participants of the longitudinal Tehran Lipid and Glucose Study. Demographic information and the age of menarche were recorded in a questionnaire. We have considered a minimal of 25 years duration to be one generation. Distribution of the menarcheal age and linear regression were performed. The mean age of menarche in daughters and their mothers were 13.2+-1.4 and 13.6+-1.5 years, respectively. There was significant correlation between the mother and daughter menarcheal age (r=0.25, P<0.002). 25th, 50th and 75th percentiles for menarcheal ages in daughters and their mothers were 12.2, 13.1, 14.1 and 12.7, 13.5, 14.5 years respectively. Minimum and maximum ages of menarche were the same (10 and 18 years) in the two groups. We found a decrease in the average menarcheal age during 25 years (one generation) similar to the results of other studies. (author)

  8. In- and outdoor reproduction of first generation common sole Solea solea under a natural photothermal regime: Temporal progression of sexual maturation assessed by monitoring plasma steroids and gonadotropin mRNA experssion

    NARCIS (Netherlands)

    Palstra, A.P.; Blok, M.C.; Kals, J.; Blom, E.; Tuinhof-Koelma, N.; Dirks, R.P.; Forlenza, M.; Blonk, R.J.W.

    2015-01-01

    Reproduction of many temperate fishes is seasonal and maturation and spawning of gametes are under photothermal control. Reproductive success of first generation (G1) common sole Solea solea in captivity has been low. In this study, the sexual maturation status has been assessed during the

  9. Reproductive biology and mating system estimates of two Andean melocacti, Melocactus schatzlii and M. andinus (Cactaceae).

    Science.gov (United States)

    Nassar, Jafet M; Ramírez, Nelson; Lampo, Margarita; González, José Antonio; Casado, Roberto; Nava, Francisco

    2007-01-01

    The genus Melocactus comprises 36 species of globose cacti with the most derived traits in the Cereeae tribe. It is the proper study system to examine what are the most derived reproductive strategies within that tribe. This study aims to characterize the reproductive biology and to estimate the mating system parameters of two Andean melocacti, Melocactus schatzlii and M. andinus. The reproductive attributes of the two species were described, including floral morphology, anthesis patterns, floral rewards, floral visitors and visitation patterns. Levels of self-compatibility and autonomous self-pollination were estimated by hand-pollination experiments. Mating system estimates were obtained by conducting progeny array analyses using isozymes. The flowers of the two species present the typical hummingbird-pollination syndrome. Despite their morphological resemblance, the two species differ in flower size, pollen and ovule production and anthesis pattern. Their main pollinator agents are hummingbirds, four species in M. schatzlii and one species in M. andinus. Both cacti are self-compatible and capable of self-pollination without the aid of pollen vectors. Population-level outcrossing rate was higher for M. schatzlii (t(m)=0.9) than for M. andinus (t(m)=0.4). At the family level, outcrossing rates for most mothers of M. schatzlii were higher (t(m)>0.8) than for M. andinus (t(m)<0.5). Although the two cacti are capable of selfing, M. schatzlii is a predominantly outcrossing species, while M. andinus behaves as a mixed-mating cactus. Hummingbirds are the only pollinators responsible for outcrossing and gene flow events in these species. In their absence, both melocacti set seeds by selfing. Based on its low population size, restricted distribution in Venezuela, low rates of floral visits, and high levels of inbreeding, M. andinus is considered to be an endangered species deserving further study to define its conservation status.

  10. Adolescent's perspective on reproductive health: a study from Karachi

    International Nuclear Information System (INIS)

    Shahid, A.; Nasim, S.; Memon, A.A.; Mustafa, M.A.

    2012-01-01

    Objectives: To determine the existing knowledge, attitude and behavior about reproductive and sexual health in adolescents of Karachi and seek their opinion about reproductive health education. Study type, settings and duration: A cross sectional study was conducted on adolescents (17-19 years) of both gender studying in colleges of Karachi during 2010. Subject sand Methods: Using stratified sampling procedure, a cross sectional study was carried out. After informed consent and ensuring confidentiality an anonymous quantitative questionnaire was completed to ascertain the knowledge of adolescents on reproductive health. Results: A total of 912 adolescents (470 males and 442 females) of 12 public and private sector colleges of Karachi participated in the study. Acquaintance to reproductive health was present in 75% males and 71% females and most participants confirmed discussing reproductive health issues with friends. About 81% males and 91 % females affirmed for a need for enhanced reproductive health education and awareness while over 50% of the respondents were of the opinion that the right age for reproductive health education was 16 to 18 years. Confining sexual activity to one partner and avoiding exposure to blood and needles for the prevention of AIDS was known to 38% males and 44% females but the prevention of sexually transmitted infections using condoms, was known to only 1/3 rd of the respondents. Although 70% of the respondents of both genders knew that pregnancy can be avoided but only 20% knew about contraceptives. Conclusions: Most adolescents' knew about the reproductive cycle but were not well aware of how to avoid exposures to sexually transmitted infections and pregnancies. Policy message: Reproductive health education is insufficient in adolescents should be gender specific and socio culturally sensitive. (author)

  11. MALLARD REPRODUCTIVE TESTING IN A POND ENVIRONMENT: A PRELIMINARY STUDY

    Science.gov (United States)

    A 2-year preliminary study was conducted on mallard ducks to determine the feasibility of using outdoor pond enclosures for reproductive studies and to evaluate the effects of the insecticide chlorpyrifos on mallard reproduction. No significant reproductive effects were observed ...

  12. Deconstructing mammalian reproduction: using knockouts to define fertility pathways.

    Science.gov (United States)

    Roy, Angshumoy; Matzuk, Martin M

    2006-02-01

    Reproduction is the sine qua non for the propagation of species and continuation of life. It is a complex biological process that is regulated by multiple factors during the reproductive life of an organism. Over the past decade, the molecular mechanisms regulating reproduction in mammals have been rapidly unraveled by the study of a vast number of mouse gene knockouts with impaired fertility. The use of reverse genetics to generate null mutants in mice through targeted disruption of specific genes has enabled researchers to identify essential regulators of spermatogenesis and oogenesis in vivo and model human disorders affecting reproduction. This review focuses on the merits, utility, and the variations of the knockout technology in studies of reproduction in mammals.

  13. Independent life history evolution between generations of bivoltine species: a case study of cyclical parthenogenesis.

    Science.gov (United States)

    Hood, Glen R; Ott, James R

    2017-04-01

    Successive generations of bi- and multivoltine species encounter differing biotic and abiotic environments intra-annually. The question of whether selection can independently adjust the relationship between body size and components of reproductive effort within successive generations in response to generation-specific environmental variation is applicable to a diversity of taxa. Herein, we develop a conceptual framework that illustrates increasingly independent life history adjustments between successive generations of taxa exhibiting complex life cycles. We apply this framework to the reproductive biology of the gall-forming insect, Belonocnema treatae (Hymenoptera: Cynipidae). This bivoltine species expresses cyclical parthenogenesis in which alternating sexual and asexual generations develop in different seasons and different environments. We tested the hypotheses that ecological divergence between the alternate generations is accompanied by generational differences in body size, egg size, and egg number and by changes in the relationships between body size and these components of reproductive effort. Increased potential reproductive effort of sexual generation B. treatae is attained by increased body size and egg number (with no trade-off between egg number and egg size) and by a significant increase in the slope of the relationship between body size and potential fecundity. These generation-specific relationships, interpreted in the context of the model framework, suggest that within each generation selection has independently molded the relationships relating body size to potential fecundity and potential reproductive effort in B. treatae. The conceptual framework is broadly applicable to comparisons involving the alternating generations of bi- and multivoltine species.

  14. Effect of dog food containing 460 ppm fluoride on rat reproduction.

    Science.gov (United States)

    Marks, T A; Schellenberg, D; Metzler, C M; Oostveen, J; Morey, M J

    1984-01-01

    A one-generation, two-litter rat reproduction study was done in a kennel in Allegan County, Michigan, as part of an investigation of reproductive problems in Shetland sheepdogs (shelties). Since 1970, at least 115 sheltie litters at this kennel have been grossly deformed and/or have died, generally within 3 d of birth. The causative factor(s) appears to be associated with the environment, as the shelties have had successful pregnancies elsewhere. There was some concern that a potential threat to human reproduction also might exist in this area. After it was discovered that fluoride in the dog food had apparently caused mottled teeth and bony exostoses in dogs at this and at least two other kennels, dog-food fluoride content and local well water were investigated as possible causes of the reproductive problems. A two-way factorial statistical design allowed assessment of dietary fluoride content and water source and interaction between the two. UPj:TUC(SD)spf rats, 9 males and 18 females in each group, were assigned to treatment with high-fluoride dog food (460 ppm) and well water; high-fluoride dog food and distilled water; low-fluoride dog food (56 ppm) and well water; and low-fluoride dog food and distilled water. After 60 d in the kennel, the rats were mated. Even after two litters, the only adverse effect was dental fluorosis in the high-fluoride groups. The results indicated that rats cannot be used in the search for the cause(s) of reproductive problems in dogs in this kennel.

  15. Assesment on Reproductive Performance and Hormonal Studies in Rural Women Beedi Rollers in Jagitial District of Telangana State

    Directory of Open Access Journals (Sweden)

    Vanitha Baluka

    2017-10-01

    Full Text Available Beedi manufacturing is the second largest industry in India. It provides employment to millions of women mostly from the poor socioeconomic class. In North region of Telangana, beedi rolling is a major occupation for illiterate women in many villages. It may affect due to the inhalation of unfiltered tobacco dust and volatile and toxic components of tobacco. Biomonitoring of women beedi rollers and their reproductive performance assessment is necessary to take prevention/control the reproduction failure and carcinogen effect on cervical system. Continuous exposed to unfiltered tobacco dust may have systemic effect and lead to many disorders including hormone defects and reproductive health problems. Although studies have been carried out on beedi industry workers and tobacco smoke exposed people at national and international level, no such studies were carried out on women beedi rollers living in rural areas in Telangana State. Hence, this investigation is attempted to understand the study is find to association with hormonal levels and reproductive outcome in rural women beedi rollers of reproductive age in North Telangana. Statistical analysis was done for the obtained results to find the significance between the two groups for the reproductive outcome and Hormonal Studies. Total 50 women (married who are exposed minimum 6-10 years to the unfiltered tobacco dust beedi rollers in the age group of 25 to 45 years from villages of Jagitial district were enrolled for this study. 50 equal numbers of women in the same age group belonging to the same socio economic status and not exposed occupationally to chemical and physical agents was selected for comparison (control group. Estroidal, Progesterone the T3, T4 and TSH levels were measured found significantly T3, T4 levels were low in the beedi rollers, compared the controls. TSH levels were found to be higher in the beedi rollers. Estroidal and progesterone levels were obtained non

  16. Experimental study of a quantum random-number generator based on two independent lasers

    Science.gov (United States)

    Sun, Shi-Hai; Xu, Feihu

    2017-12-01

    A quantum random-number generator (QRNG) can produce true randomness by utilizing the inherent probabilistic nature of quantum mechanics. Recently, the spontaneous-emission quantum phase noise of the laser has been widely deployed for quantum random-number generation, due to its high rate, its low cost, and the feasibility of chip-scale integration. Here, we perform a comprehensive experimental study of a phase-noise-based QRNG with two independent lasers, each of which operates in either continuous-wave (CW) or pulsed mode. We implement the QRNG by operating the two lasers in three configurations, namely, CW + CW, CW + pulsed, and pulsed + pulsed, and demonstrate their trade-offs, strengths, and weaknesses.

  17. On two-generator satellite knots

    OpenAIRE

    Bleiler, Steven A.; Jones, Amelia C.

    1997-01-01

    Techniques are introduced which determine the geometric structure of non-simple two-generator $3$-manifolds from purely algebraic data. As an application, the satellite knots in the $3$-sphere with a two-generator presentation in which at least one generator is represented by a meridian for the knot are classified.

  18. Reproductive broodstock performance and egg quality of wild-caught and first-generation domesticated Seriola rivoliana reared under same culture conditions

    Directory of Open Access Journals (Sweden)

    Marcos F Quiñones-Arreola

    2015-11-01

    Full Text Available Almaco jack, Seriola rivoliana as well as some related species is of great interest in marine fish aquaculture. However, there are few studies about their reproduction in captivity. In this research work, reproductive performance and egg quality in two groups of adult Seriola rivoliana, caught in the wild and domesticated-F1 analyzed and compared, reared under optimal maturation conditions in a commercial private Laboratory. A total of 28 wild adult (>5 kg were caught at La Paz Bay, Baja California Sur, Mexico, and 30 adult domesticated-F1 broodstock (>5 kg, were obtained from an original stock of 1,000 juveniles (3.5 g body weight produced at Kona Blue (Hawaii, USA sea farm. Fishes were transported to the Rancheros del Mar commercial private hatchery, where they were grown to adult size. Both groups were evaluated during eight months (May to December 2012 and compared in terms of reproduction performance (total number of spawning events, monthly spawning frequency, total number of eggs, total number of eggs per mL, and fertilization rate, egg biochemical composition (total proteins, total lipids, total carbohydrates, and triacylglycerides and egg diameter. Results indicated that wild caught broostock showed a better reproductive performance in terms of fertilization rate, total number of spawning, monthly spawning frequency and total number of eggs produced. However, biochemical composition and egg diameter did not show statistical differences (P < 0.05 between two groups. The reproductive performance of broodstock and quality of eggs analyzed in this study are important traits to improve the aquaculture management of this species.

  19. Generation and evaluation of an indicator of the health system's performance in maternal and reproductive health in Colombia: An ecological study.

    Science.gov (United States)

    Pinzón-Flórez, Carlos Eduardo; Fernandez-Niño, Julian Alfredo; Cardenas-Cardenas, Luz Mery; Díaz-Quijano, Diana Marcela; Ruiz-Rodriguez, Myriam; Reveiz, Ludovic; Arredondo-López, Armando

    2017-01-01

    To generate and evaluate an indicator of the health system's performance in the area of maternal and reproductive health in Colombia. An indicator was constructed based on variables related to the coverage and utilization of healthcare services for pregnant and reproductive-age women. A factor analysis was performed using a polychoric correlation matrix and the states were classified according to the indicator's score. A path analysis was used to evaluate the relationship between the indicator and social determinants, with the maternal mortality ratio as the response variable. The factor analysis indicates that only one principal factor exists, namely "coverage and utilization of maternal healthcare services" (eigenvalue 4.35). The indicator performed best in the states of Atlantic, Bogota, Boyaca, Cundinamarca, Huila, Risaralda and Santander (Q4). The poorest performance (Q1) occurred in Caqueta, Choco, La Guajira, Vichada, Guainia, Amazonas and Vaupes. The indicator's behavior was found to have an association with the unsatisfied basic needs index and women's education (β = -0.021; 95%CI -0031 to -0.01 and β 0.554; 95%CI 0.39 to 0.72, respectively). According to the path analysis, an inverse relationship exists between the proposed indicator and the behavior of the maternal mortality ratio (β = -49.34; 95%CI -77.7 to -20.9); performance was a mediating variable. The performance of the health system with respect to its management of access and coverage for maternal and reproductive health appears to function as a mediating variable between social determinants and maternal mortality in Colombia.

  20. Generation and evaluation of an indicator of the health system's performance in maternal and reproductive health in Colombia: An ecological study.

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Pinzón-Flórez

    Full Text Available To generate and evaluate an indicator of the health system's performance in the area of maternal and reproductive health in Colombia.An indicator was constructed based on variables related to the coverage and utilization of healthcare services for pregnant and reproductive-age women. A factor analysis was performed using a polychoric correlation matrix and the states were classified according to the indicator's score. A path analysis was used to evaluate the relationship between the indicator and social determinants, with the maternal mortality ratio as the response variable.The factor analysis indicates that only one principal factor exists, namely "coverage and utilization of maternal healthcare services" (eigenvalue 4.35. The indicator performed best in the states of Atlantic, Bogota, Boyaca, Cundinamarca, Huila, Risaralda and Santander (Q4. The poorest performance (Q1 occurred in Caqueta, Choco, La Guajira, Vichada, Guainia, Amazonas and Vaupes. The indicator's behavior was found to have an association with the unsatisfied basic needs index and women's education (β = -0.021; 95%CI -0031 to -0.01 and β 0.554; 95%CI 0.39 to 0.72, respectively. According to the path analysis, an inverse relationship exists between the proposed indicator and the behavior of the maternal mortality ratio (β = -49.34; 95%CI -77.7 to -20.9; performance was a mediating variable.The performance of the health system with respect to its management of access and coverage for maternal and reproductive health appears to function as a mediating variable between social determinants and maternal mortality in Colombia.

  1. Steam generator transient studies using a simplified two-fluid computer code

    International Nuclear Information System (INIS)

    Munshi, P.; Bhatnagar, R.; Ram, K.S.

    1985-01-01

    A simplified two-fluid computer code has been used to simulate reactor-side (or primary-side) transients in a PWR steam generator. The disturbances are modelled as ramp inputs for pressure, internal energy and mass flow-rate for the primary fluid. The CPU time for a transient duration of 4 s is approx. 10 min on a DEC-1090 computer system. The results are thermodynamically consistent and encouraging for further studies. (author)

  2. Studies of the reproductive biology of deep sea megabenthos

    International Nuclear Information System (INIS)

    Tyler, P.A.; Muirhead, A.

    1986-06-01

    Specimens of six species of aspidochirota from depths between 1245 and 2315m in the N.E. Atlantic have been examined and their reproductive biology determined. Two species Paelopatides grisea and Benthothuria funebris produce the large eggs typical of direct development. Mesothuria lactea and M. verrilli have an intermediate egg size of c. 400μm whilst Bathyplotes natans has an egg size of c. 280μm, which may be indicative of indirect development. The last species Paroriza pallens is an hermaphrodite producing an egg of c. 250μm. With the exception of Bathyplotes natans, which appears to show periodic reproduction if not seasonal, the species show no evidence of reproductive seasonality. (author)

  3. Reproductive features and behavoir of Podilymbus Podiceps (Aves: Podicipedidae in two wetlands of Bogotá, Colombia

    Directory of Open Access Journals (Sweden)

    Henry D. Benítez

    2004-01-01

    Full Text Available The wetland Santa María del Lago and La Florida, Bogotá (Colombia, were selected to study the reproduction and behavior of Podilymbus podiceps, during September of 1998 to June of 2000. Observations were accomplished in striping and fix stations in both localities studied. We evidence that Podilymbus podiceps establishes temporary monogamous sexual links during approximately four months. In 15 couples (13 in Santa María del Lago, 2 in La Florida we observed the reproductive cycle phases: couple training, courting, coitus, and the cooperative participation of the male and the female on nests elaboration and egg hatching. The nests were elaborated with the aquatic vegetation present in the wetland and mud. The nest contains consists of 1 - 6 eggs, which due to the temperature and elaborating material varied their coloration. Furthermore, we document the parental care and the period of sucklings emancipation in the wetland Santa María del Lago, where we showed that the reproduction was successful since August 1999 towards the end of the study, apparently influenced by the rainfall and aquatic vegetation growth. In the wetland La Florida nesting was not viable, and the two nests registered in this place during the of study, were not successful.

  4. Human reproductive cloning: a conflict of liberties.

    Science.gov (United States)

    Havstad, Joyce C

    2010-02-01

    Proponents of human reproductive cloning do not dispute that cloning may lead to violations of clones' right to self-determination, or that these violations could cause psychological harms. But they proceed with their endorsement of human reproductive cloning by dismissing these psychological harms, mainly in two ways. The first tactic is to point out that to commit the genetic fallacy is indeed a mistake; the second is to invoke Parfit's non-identity problem. The argument of this paper is that neither approach succeeds in removing our moral responsibility to consider and to prevent psychological harms to cloned individuals. In fact, the same commitment to personal liberty that generates the right to reproduce by means of cloning also creates the need to limit that right appropriately. Discussion of human reproductive cloning ought to involve a careful and balanced consideration of both the relevant aspects of personal liberty - the parents' right to reproductive freedom and the cloned child's right to self-determination.

  5. Health assessment of gasoline and fuel oxygenate vapors: reproductive toxicity assessment.

    Science.gov (United States)

    Gray, Thomas M; Steup, David; Roberts, Linda G; O'Callaghan, James P; Hoffman, Gary; Schreiner, Ceinwen A; Clark, Charles R

    2014-11-01

    Vapor condensates of baseline gasoline (BGVC), or gasoline-blended with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA) were evaluated for reproductive toxicity in rats at target concentrations of 2000, 10,000, or 20,000mg/m(3), 6h/day, 7days/week. BGVC and G/MTBE were assessed over two generations, the others for one generation. BGVC and G/MTBE F1 offspring were evaluated for neuropathology and changes in regional brain glial fibrillary acidic protein content. No neurotoxicity was observed. Male kidney weight was increased consistent with light hydrocarbon nephropathy. In adult rats, decreased body weight gain and increased liver weight were seen. Spleen weight decreased in adults and pups exposed to G/TBA. No pathological changes to reproductive organs occurred in any study. Decreased food consumption was seen in G/TAME lactating females. Transient decreases in G/TAME offspring weights were observed during lactation. Except for a minor increase in time to mating in G/TBA which did not affect other reproductive parameters, there were no adverse reproductive findings. The NOAEL for reproductive and offspring parameters was 20,000mg/m(3) for all vapor condensates except for lower offspring NOAELs of 10,000mg/m(3) for G/TBA and 2000mg/m(3) for G/TAME. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Timing of breeding and reproductive output in two Black-tailed Godwit Limosa limosa populations in The Netherlands

    NARCIS (Netherlands)

    Roodbergen, Maja; Klok, Chris

    2008-01-01

    To get a better understanding of the current population decline of Black-tailed Godwits in The Netherlands, we determined reproductive parameters in two Dutch breeding populations over the period 2002-2005 and investigated the relationship between reproductive output and timing of breeding. Annual

  7. Timing of breeding and reproductive output in two Black-tailed Godwit Limosa limosa populations in The Netherlands

    NARCIS (Netherlands)

    Roodbergen, M.; Klok, C.

    2008-01-01

    To get a better understanding of the current population decline of Black-tailed Godwits in The Netherlands, we determined reproductive parameters in two Dutch breeding populations over the period 2002¿2005 and investigated the relationship between reproductive output and timing of breeding. Annual

  8. Reproductive effects of two neonicotinoid insecticides on mouse sperm function and early embryonic development in vitro.

    Directory of Open Access Journals (Sweden)

    Yi-Hua Gu

    Full Text Available Acetamiprid (ACE and imidacloprid (IMI are two major members in the family of neonicotinoid pesticides, which are synthesized with a higher selectivity to insects. The present study determined and compared in vitro effects of ACE, IMI and nicotine on mammalian reproduction by using an integrated testing strategy for reproductive toxicology, which covered sperm quality, sperm penetration into oocytes and preimplantation embryonic development. Direct chemical exposure (500 µM or 5 mM on spermatozoa during capacitation was performed, and in vitro fertilization (IVF process, zygotes and 2-cell embryos were respectively incubated with chemical-supplemented medium until blastocyst formation to evaluate the reproductive toxicity of these chemicals and monitor the stages mainly affected. Generally, treatment of 500 µM or 5 mM chemicals for 30 min did not change sperm motility and DNA integrity significantly but the fertilization ability in in vitro fertilization (IVF process, indicating that IVF process could detect and distinguish subtle effect of spermatozoa exposed to different chemicals. Culture experiment in the presence of chemicals in medium showed that fertilization process and zygotes are adversely affected by direct exposure of chemicals (PIMI>ACE, whereas developmental progression of 2-cell stage embryos was similar to controls (P>0.05. These findings unveiled the hazardous effects of neonicotinoid pesticides exposure on mammalian sperm fertilization ability as well as embryonic development, raising the concerns that neonicotinoid pesticides may pose reproductive risks on human reproductive health, especially in professional populations.

  9. Two-host, two-vector basic reproduction ratio (R(0 for bluetongue.

    Directory of Open Access Journals (Sweden)

    Joanne Turner

    Full Text Available Mathematical formulations for the basic reproduction ratio (R(0 exist for several vector-borne diseases. Generally, these are based on models of one-host, one-vector systems or two-host, one-vector systems. For many vector borne diseases, however, two or more vector species often co-occur and, therefore, there is a need for more complex formulations. Here we derive a two-host, two-vector formulation for the R(0 of bluetongue, a vector-borne infection of ruminants that can have serious economic consequences; since 1998 for example, it has led to the deaths of well over 1 million sheep in Europe alone. We illustrate our results by considering the situation in South Africa, where there are two major hosts (sheep, cattle and two vector species with differing ecologies and competencies as vectors, for which good data exist. We investigate the effects on R(0 of differences in vector abundance, vector competence and vector host preference between vector species. Our results indicate that R(0 can be underestimated if we assume that there is only one vector transmitting the infection (when there are in fact two or more and/or vector host preferences are overlooked (unless the preferred host is less beneficial or more abundant. The two-host, one-vector formula provides a good approximation when the level of cross-infection between vector species is very small. As this approaches the level of intraspecies infection, a combination of the two-host, one-vector R(0 for each vector species becomes a better estimate. Otherwise, particularly when the level of cross-infection is high, the two-host, two-vector formula is required for accurate estimation of R(0. Our results are equally relevant to Europe, where at least two vector species, which co-occur in parts of the south, have been implicated in the recent epizootic of bluetongue.

  10. Generation time, net reproductive rate, and growth in stage-age-structured populations

    DEFF Research Database (Denmark)

    Steiner, Uli; Tuljapurkar, Shripad; Coulson, Tim

    2014-01-01

    examples to show how reproductive timing Tc and level R0 are shaped by stage dynamics (individual trait changes), selection on the trait, and parent-offspring phenotypic correlation. We also show how population structure can affect dispersion in reproduction among ages and stages. These macroscopic...... to age-structured populations. Here we generalize this result to populations structured by stage and age by providing a new, unique measure of reproductive timing (Tc) that, along with net reproductive rate (R0), has a direct mathematical relationship to and approximates growth rate (r). We use simple...

  11. Automatic Generation Control Study in Two Area Reheat Thermal Power System

    Science.gov (United States)

    Pritam, Anita; Sahu, Sibakanta; Rout, Sushil Dev; Ganthia, Sibani; Prasad Ganthia, Bibhu

    2017-08-01

    Due to industrial pollution our living environment destroyed. An electric grid system has may vital equipment like generator, motor, transformers and loads. There is always be an imbalance between sending end and receiving end system which cause system unstable. So this error and fault causing problem should be solved and corrected as soon as possible else it creates faults and system error and fall of efficiency of the whole power system. The main problem developed from this fault is deviation of frequency cause instability to the power system and may cause permanent damage to the system. Therefore this mechanism studied in this paper make the system stable and balance by regulating frequency at both sending and receiving end power system using automatic generation control using various controllers taking a two area reheat thermal power system into account.

  12. Selection bias in studies of human reproduction-longevity trade-offs.

    Science.gov (United States)

    Helle, Samuli

    2017-12-13

    A shorter lifespan as a potential cost of high reproductive effort in humans has intrigued researchers for more than a century. However, the results have been inconclusive so far and despite strong theoretical expectations we do not currently have compelling evidence for the longevity costs of reproduction. Using Monte Carlo simulation, it is shown here that a common practice in human reproduction-longevity studies using historical data (the most relevant data sources for this question), the omission of women who died prior to menopausal age from the analysis, results in severe underestimation of the potential underlying trade-off between reproduction and lifespan. In other words, assuming that such a trade-off is expressed also during reproductive years, the strength of the trade-off between reproduction and lifespan is progressively weakened when women dying during reproductive ages are sequentially and non-randomly excluded from the analysis. In cases of small sample sizes (e.g. few hundreds of observations), this selection bias by reducing statistical power may even partly explain the null results commonly found in this field. Future studies in this field should thus apply statistical approaches that account for or avoid selection bias in order to recover reliable effect size estimates between reproduction and longevity. © 2017 The Author(s).

  13. Exhaust energy conversion by thermoelectric generator: Two case studies

    International Nuclear Information System (INIS)

    Karri, M.A.; Thacher, E.F.; Helenbrook, B.T.

    2011-01-01

    This study reports predictions of the power and fuel savings produced by thermoelectric generators (TEG) placed in the exhaust stream of a sports utility vehicle (SUV) and a stationary, compressed-natural-gas-fueled engine generator set (CNG). Results are obtained for generators using either commercially-available bismuth telluride (Bi 2 Te 3 ) or quantum-well (QW) thermoelectric material. The simulated tests are at constant speed in the SUV case and at constant AC power load in the CNG case. The simulations make use of the capabilities of ADVISOR 2002, the vehicle modeling system, supplemented with code to describe the thermoelectric generator system. The increase in power between the QW- and Bi 2 Te 3 -based generators was about three times for the SUV and seven times for the CNG generator under the same simulation conditions. The relative fuel savings for the SUV averaged around -0.2% using Bi 2 Te 3 and 1.25% using QW generators. For the CNG case the fuel savings was around 0.4% using Bi 2 Te 3 and around 3% using QW generators. The negative fuel gains in the SUV were caused by parasitic losses. The power to transport the TEG system weight was the dominant parasitic loss for the SUV but was absent in the CNG generator. The lack of space constraint and the absence of parasitic loss from the TEG system weight in the CNG case allowed an increase in the TEG system size to generate more power.

  14. Assisted reproductive technology in Europe, 2012: results generated from European registers by ESHREaEuro

    DEFF Research Database (Denmark)

    Calhaz-Jorge, C.; De Geyter, C.; Kupka, M. S.

    2016-01-01

    The 16th European IVF-monitoring (EIM) report presents the data of the treatments involving assisted reproductive technology (ART) and intrauterine insemination (IUI) initiated in Europe during 2012: are there any changes compared with previous years? Despite some fluctuations in the number...... with husband and donor semen, respectively. The method of reporting varies among countries, and registers from a number of countries have been unable to provide some of the relevant data such as initiated cycles and deliveries. As long as data are incomplete and generated through different methods...

  15. Gene-environment interaction and male reproductive function

    Science.gov (United States)

    Axelsson, Jonatan; Bonde, Jens Peter; Giwercman, Yvonne L.; Rylander, Lars; Giwercman, Aleksander

    2010-01-01

    As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between and within populations, genetic variants might be important determinants of the individual susceptibility to the adverse effects of environment or lifestyle. Although the possible mechanisms of such interplay in relation to the reproductive system are largely unknown, some recent studies have indicated that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism, but the number of studies is still limited. This type of interaction studies may improve our understanding of normal physiology and help us to identify the risk factors to male reproductive malfunction. We also shortly discuss other aspects of gene-environment interaction specifically associated with the issue of reproduction, namely environmental and lifestyle factors as the cause of sperm DNA damage. It remains to be investigated to what extent such genetic changes, by natural conception or through the use of assisted reproductive techniques, are transmitted to the next generation, thereby causing increased morbidity in the offspring. PMID:20348940

  16. Reproductive Disorder Studies Using Radioimmunoassay (RIA) Progesterone Technique

    International Nuclear Information System (INIS)

    Tuasikal, Boky Jeanne; Totti Tjiptosumirat; Ratnawati Kukuh

    2004-01-01

    Five dairy cattle, cattle A: 6 th parity; cattle B: 7 th parity; cattle C: 2 nd parity; cattle D and F: 3 rd parity, were used in this study. According to Health Extension and Artificial Insemination Technicians anamneses and according to farmers who own the animals, these cattle were showing reproductive failure, and RIA technique was used to study the symptoms. For this purpose, milk progesterone sample were collected twice a week for five weeks to follow the biological reproductive status of every animal. Result from the analysis were plotted for each individual animal and shows that cattle A and B were acyclic, which indicated that no reproductive activity post partum have occurred in both animals; cattle C in the status of prolonged oestrus cycle post partum; and cattle D and F were in the status of recovery of oestrus cycle post partum. With the availability of historical record of the cattle and confirmation of biological status by Health Technicians, the reproductive disorder, which leads to the failure of AI in dairy cattle, can be monitored by RIA Progesterone technique. (author)

  17. Exhaust energy conversion by thermoelectric generator: Two case studies

    Energy Technology Data Exchange (ETDEWEB)

    Karri, M.A.; Thacher, E.F.; Helenbrook, B.T. [Department of Mechanical and Aeronautical Engineering, PO Box 5725, Clarkson University, Potsdam, NY 13699 (United States)

    2011-03-15

    This study reports predictions of the power and fuel savings produced by thermoelectric generators (TEG) placed in the exhaust stream of a sports utility vehicle (SUV) and a stationary, compressed-natural-gas-fueled engine generator set (CNG). Results are obtained for generators using either commercially-available bismuth telluride (Bi{sub 2}Te{sub 3}) or quantum-well (QW) thermoelectric material. The simulated tests are at constant speed in the SUV case and at constant AC power load in the CNG case. The simulations make use of the capabilities of ADVISOR 2002, the vehicle modeling system, supplemented with code to describe the thermoelectric generator system. The increase in power between the QW- and Bi{sub 2}Te{sub 3}-based generators was about three times for the SUV and seven times for the CNG generator under the same simulation conditions. The relative fuel savings for the SUV averaged around -0.2% using Bi{sub 2}Te{sub 3} and 1.25% using QW generators. For the CNG case the fuel savings was around 0.4% using Bi{sub 2}Te{sub 3} and around 3% using QW generators. The negative fuel gains in the SUV were caused by parasitic losses. The power to transport the TEG system weight was the dominant parasitic loss for the SUV but was absent in the CNG generator. The lack of space constraint and the absence of parasitic loss from the TEG system weight in the CNG case allowed an increase in the TEG system size to generate more power. (author)

  18. Sectarianism and the problem of overpopulation: political representations of reproduction in two low-income neighbourhoods of Beirut, Lebanon.

    Science.gov (United States)

    Premkumar, Ashish; Salem, Karma; Akhtar, Sarah; Deeb, Mary E; Messersmith, Lisa J

    2012-01-01

    The role of confessionalism in the Lebanese healthcare sector, especially since the resolution of the Lebanese civil war (1975-1990), has yet to discussed at length in reproductive health research. Using biopolitical and structural violence models to describe how community leaders in two low-income neighbourhoods in Beirut describe reproductive healthcare - specifically through judgments of perceived sect size vis-à-vis perceived use of birth control measures - this paper attempts to provide critical analysis of the state of reproductive health in this setting. By using a theoretical model of analysis, which we refer to as the political anatomy of reproduction, we hope to unmask how confessionalism is perpetuated through discussions of reproductive health and how public health and medical communities can challenge this technique of power.

  19. Reproductive ecology and egg production of the radiated tortoise ...

    African Journals Online (AJOL)

    We studied reproduction of wild Geochelone radiata at the Cap Sainte Marie Special Reserve in southwestern Madagascar to gain insight into life history traits related to reproductive success. Reproductive behaviour was observed over two nesting seasons and egg production was studied by radiographing telemetered ...

  20. On the Reproduction Number of a Gut Microbiota Model.

    Science.gov (United States)

    Barril, Carles; Calsina, Àngel; Ripoll, Jordi

    2017-11-01

    A spatially structured linear model of the growth of intestinal bacteria is analysed from two generational viewpoints. Firstly, the basic reproduction number associated with the bacterial population, i.e. the expected number of daughter cells per bacterium, is given explicitly in terms of biological parameters. Secondly, an alternative quantity is introduced based on the number of bacteria produced within the intestine by one bacterium originally in the external media. The latter depends on the parameters in a simpler way and provides more biological insight than the standard reproduction number, allowing the design of experimental procedures. Both quantities coincide and are equal to one at the extinction threshold, below which the bacterial population becomes extinct. Optimal values of both reproduction numbers are derived assuming parameter trade-offs.

  1. Grandparental effects on reproductive strategizing

    Directory of Open Access Journals (Sweden)

    2004-09-01

    Full Text Available This paper analyzes data from the household registers for two villages in the Nôbi region of central Japan in the late Edo period (1717-1869 to assess how grandparents may have affected reproductive strategizing in stem families. The particulars of the family system fostered a culturally favored set of reproductive goals, in particular, a daughter as eldest child, followed by a son (and heir, coupled with gender alternation in subsequent reproduction and overall gender balance. This reproductive strategy was generally followed during the stem phase of the domestic cycle, when one or both grandparents were present, especially when the family head was in the senior generation. By contrast, a son-first strategy was favored when childbearing began in the conjugal phase of the cycle. This suggests grandparental influence on the junior couple's reproductive decisions in favor of the cultural ideal. I find that the senior couple's decision to marry the heir early or late strongly affects the reproductive strategies followed by him after marriage. I show that when a grandmother is present at the onset of childbearing, especially if she is relatively young, the junior couple ends up with more offspring on average. A controlled analysis of infanticiding behavior is interpreted in terms of conjugal power and coalition formation. It appears that a grandmother gets her way only when she and her son gang up on the daughter-in-law, but such a coalition is likely only when her son dominates the conjugal relationship (which in turn reflects the grandmother's success in binding the son tightly to her emotionally and in delaying his marriage. Otherwise, the grandmother may be shut out from reproductive decision-making by the solidary conjugal coalition.

  2. Economic evaluation studies in reproductive medicine: a systematic review of methodologic quality

    NARCIS (Netherlands)

    Moolenaar, Lobke M.; Vijgen, Sylvia M. C.; Hompes, Peter; van der Veen, Fulco; Mol, Ben Willem J.; Opmeer, Brent C.

    2013-01-01

    To evaluate the methodologic quality of economic analyses published in the field of reproductive medicine. Systematic review. Centers for reproductive care. Infertility patients. We performed a Medline search to identify economic evaluation studies in reproductive medicine. We included studies that

  3. Annual reproductive cycle in two free living populations of three-spined stickleback (Gasterosteus aculeatus L.: patterns of ovarian and testicular development

    Directory of Open Access Journals (Sweden)

    Ewa Sokołowska

    2006-03-01

    Full Text Available The annual reproductive cycle in two wild populations of three-spinedstickleback was studied. Sticklebacks from the Dead Vistula River(Martwa Wisła (brackish water and the Oliva Stream (Potok Oliwski(freshwater were exposed to annual environmental changes in their naturalhabitats. Ovaries and livers (females, and testes and kidneys (males werecollected during 1-2 years. The gonadosomatic IG, hepatosomaticIH, nephrosomatic IN indices, kidney epithelium height(KEH and size of oocytes were calculated.The number of mature oocytes andpercentage of ovulating females were determined during the spawning season.Histological changes in the ovaries and testes were described throughouta year. Annual reproductive cycles were similar in both populations ofsticklebacks. This is the first histological and morphological study carriedout throughout a year, simultaneously in two wild populations of three-spinedsticklebacks inhabiting different environments. An improved scale of gonadaldevelopment in conjunction with the determined indices and fecundity givea comprehensive description of the reproductive cycle. These new observations,in combination with previously reported features, provide a universal scalethat can be successfully used to distinguish all phases of gametogenesis insticklebacks in different habitats.

  4. Studies on three-dimensional reproduction of maxillofacial cranium shape, 2

    International Nuclear Information System (INIS)

    Mihara, Manabu

    1984-01-01

    The purpose of the serial studies were to develop a three-dimensional reproduction for diagnosis and surgical therapy planning. In the present study, the author devised the methd of making models reproduced through applying high resolutional computed tomography (GE CT/T). Preliminary examinations were carried out on the CT numbers and on the measurement of CT film images for three-dimensional reproduction. The results are summarized below: 1) There were few hourly changes of CT numbers. 2) At the interspace of the phantom teflon rod and water, CT numbers changed gradually because of the partial volume effect and the edge response. Although the true boundaries of the materials could be indentified with the median CT number of the two substances. 3) Setting up to 1,000 on the window level and 1,200 on the window width, the measurement value of the views of the phantom teflon rod which had been magnified 1.8 power coincided with the true size. 4) Supplementary examinations were carried out on the same methods using a pig mandible, and the results were affirmed. The models were made of acrilic boards which the images of CT films were traced. Those boards were waxed up and trimmed in the boxies for three-dimensional reproduction by using cephalograms. The reproducible accuracy of the completed models was satisfactory for use in the field of the maxillofacial surgery. (author)

  5. Changing reproductive effort within a semelparous reproductive episode.

    Science.gov (United States)

    Hughes, P William; Simons, Andrew M

    2014-08-01

    • Life-history theory predicts a trade-off between current and future reproduction for iteroparous organisms-as individuals age, the expected value of future reproduction declines, and thus reproductive effort is expected to be higher in later clutches than in earlier. In contrast, models explaining the evolution of semelparity treat semelparous reproduction as instantaneous, with no scope for intraindividual variation. However, semelparous reproduction is also extended, but over shorter time scales; whether there are similar age- or stage-specific changes in reproductive effort within a semelparous episode is unclear. In this study, we assessed whether semelparous individuals increase reproductive effort as residual reproductive value declines by comparing the reproductive phenotype of flowers at five different floral positions along a main inflorescence.• Using the herbaceous monocarp Lobelia inflata, we conducted a longitudinal study of 409 individuals including both laboratory and field populations over three seasons. We recorded six reproductive traits-including the length of three phenological intervals as well as fruit size, seed size, and seed number-for all plants across floral positions produced throughout the reproductive episode.• We found that while the rate of flower initiation did not change, flowers at distal (late) floral positions developed more quickly and contained larger seed than flowers at basal (early) floral positions did.• Our results were consistent with the hypothesis that, like iteroparous organisms, L. inflata increases reproductive effort in response to low residual reproductive value. © 2014 Botanical Society of America, Inc.

  6. Reproductive effort affects oxidative status and stress in an Antarctic penguin species: An experimental study.

    Directory of Open Access Journals (Sweden)

    Roger Colominas-Ciuró

    Full Text Available The oxidative cost of reproduction has been a matter of debate in recent years presumably because of the lack of proper experimental studies. Based on the hypothesis that different brood sizes produce differential reproductive costs, an experimental manipulation during breeding of Adélie penguins was conducted at Hope Bay, Antarctica, to study oxidative status and stress. We predict that a lower reproductive effort should be positively related to low oxidative and physiological stress. We randomly assigned nests with two chicks to a control reproductive effort group (CRE, and by removing one chick from some nests with two chicks, formed a second, low reproductive effort group (LRE. We examined how oxidative status in blood plasma (reactive oxygen metabolites, ROMs, and total antioxidant capacity, OXY and stress (heterophil/lymphocyte ratio, H/L responded to a lower production of offspring total biomass. Our nest manipulation showed significant differences in offspring total biomass, which was lower in the LRE group. As predicted, the LRE group had higher antioxidant capacity than individuals in the CRE group. We have also found, although marginally significant, interactions between sex and treatment in the three variables analysed. Females had higher OXY, lower ROMs and lower H/L ratio when rearing one chick, whereas males did so when rearing two except for OXY which was high regardless of treatment. Moreover, there was a significant negative correlation between the H/L ratio and OXY in females. Finally, we have found a negative and significant relationship between the duration of the experiment and OXY and ROMs and positive with H/L ratio which suggests that indeed breeding penguins are paying an effort in physiological terms in relation to the duration of the chick rearing. In conclusion, a reduction of the reproductive effort decreased oxidative stress in this long-lived bird meaning that a link exists between breeding effort and oxidative

  7. Reproductive effort affects oxidative status and stress in an Antarctic penguin species: An experimental study.

    Science.gov (United States)

    Colominas-Ciuró, Roger; Santos, Mercedes; Coria, Néstor; Barbosa, Andrés

    2017-01-01

    The oxidative cost of reproduction has been a matter of debate in recent years presumably because of the lack of proper experimental studies. Based on the hypothesis that different brood sizes produce differential reproductive costs, an experimental manipulation during breeding of Adélie penguins was conducted at Hope Bay, Antarctica, to study oxidative status and stress. We predict that a lower reproductive effort should be positively related to low oxidative and physiological stress. We randomly assigned nests with two chicks to a control reproductive effort group (CRE), and by removing one chick from some nests with two chicks, formed a second, low reproductive effort group (LRE). We examined how oxidative status in blood plasma (reactive oxygen metabolites, ROMs, and total antioxidant capacity, OXY) and stress (heterophil/lymphocyte ratio, H/L) responded to a lower production of offspring total biomass. Our nest manipulation showed significant differences in offspring total biomass, which was lower in the LRE group. As predicted, the LRE group had higher antioxidant capacity than individuals in the CRE group. We have also found, although marginally significant, interactions between sex and treatment in the three variables analysed. Females had higher OXY, lower ROMs and lower H/L ratio when rearing one chick, whereas males did so when rearing two except for OXY which was high regardless of treatment. Moreover, there was a significant negative correlation between the H/L ratio and OXY in females. Finally, we have found a negative and significant relationship between the duration of the experiment and OXY and ROMs and positive with H/L ratio which suggests that indeed breeding penguins are paying an effort in physiological terms in relation to the duration of the chick rearing. In conclusion, a reduction of the reproductive effort decreased oxidative stress in this long-lived bird meaning that a link exists between breeding effort and oxidative stress. However

  8. Sequentially generated states for the study of two dimensional systems

    Energy Technology Data Exchange (ETDEWEB)

    Banuls, Mari-Carmen; Cirac, J. Ignacio [Max-Planck-Institut fuer Quantenoptik, Garching (Germany); Perez-Garcia, David [Depto. Analisis Matematico, Universidad Complutense de Madrid (Spain); Wolf, Michael M. [Niels Bohr Institut, Copenhagen (Denmark); Verstraete, Frank [Fakultaet fuer Physik, Universitaet Wien (Austria)

    2009-07-01

    The family of Matrix Product States represents a powerful tool for the study of physical one-dimensional quantum many-body systems, such as spin chains. Besides, Matrix Product States can be defined as the family of quantum states that can be sequentially generated in a one-dimensional system. We have introduced a new family of states which extends this sequential definition to two dimensions. Like in Matrix Product States, expectation values of few body observables can be efficiently evaluated and, for the case of translationally invariant systems, the correlation functions decay exponentially with the distance. We show that such states are a subclass of Projected Entangled Pair States and investigate their suitability for approximating the ground states of local Hamiltonians.

  9. Reproductive endocrinology and infertility fellowships: is the 'reproductive endocrinology' portion obsolete?

    Science.gov (United States)

    Omurtag, Kenan; Lebovic, Dan I

    2015-08-01

    To take inventory of the past and present and project the future direction of our field to help train the next generation of providers. Review the history of the subspecialty and factors contributing to its evolution. Reproductive endocrinology and infertility's in-vitro fertilization future is shaping the intellectual priorities and surgical skill requirements of the next generation.

  10. Pheromone modulates two phenotypically plastic traits - adult reproduction and larval diapause - in the nematode Caenorhabditis elegans.

    Science.gov (United States)

    Wharam, Barney; Weldon, Laura; Viney, Mark

    2017-08-22

    Animals use information from their environment to make decisions, ultimately to maximize their fitness. The nematode C. elegans has a pheromone signalling system, which hitherto has principally been thought to be used by worms in deciding whether or not to arrest their development as larvae. Recent studies have suggested that this pheromone can have other roles in the C. elegans life cycle. Here we demonstrate a new role for the C. elegans pheromone, showing that it accelerates hermaphrodites' reproductive rate, a phenomenon which we call pheromone-dependent reproductive plasticity (PDRP). We also find that pheromone accelerates larval growth rates, but this depends on a live bacterial food source, while PDRP does not. Different C. elegans strains all show PDRP, though the magnitude of these effects differ among the strains, which is analogous to the diversity of arrested larval phenotypes that this pheromone also induces. Using a selection experiment we also show that selection for PDRP or for larval arrest affects both the target and the non-target trait, suggesting that there is cross-talk between these two pheromone-dependent traits. Together, these results show that C. elegans' pheromone is a signal that acts at two key life cycle points, controlling alternative larval fates and affecting adult hermaphrodites' reproduction. More broadly, these results suggest that to properly understand and interpret the biology of pheromone signalling in C. elegans and other nematodes, the life-history biology of these organisms in their natural environment needs to be considered.

  11. Germination failure is not a critical stage of reproductive isolation between three congeneric orchid species.

    Science.gov (United States)

    De Hert, Koen; Honnay, Olivier; Jacquemyn, Hans

    2012-11-01

    In food-deceptive orchid species, postmating reproductive barriers (fruit set and embryo mortality) have been shown to be more important for reproductive isolation than premating barriers (pollinator isolation). However, currently there is very little knowledge about whether germination failure acts as a reproductive barrier in hybridizing orchid species. In this study, we investigated germination and protocorm development of pure and hybrid seeds of three species of the orchid genus Dactylorhiza. To test the hypothesis that germination failure contributed to total reproductive isolation, reproductive barriers based on germination were combined with already available data on early acting barriers (fruit set and embryo mortality) to calculate the relative and absolute contributions of these barriers to reproductive isolation. Protocorms were formed in all crosses, indicating that both hybrid and pure seeds were able to germinate and grow into protocorms. Also, the number of protocorms per seed packet was not significantly different between hybrid and pure seeds. High fruit set, high seed viability, and substantial seed germination resulted in very low reproductive isolation (average RI = 0.05). In two of six interspecific crosses, hybrids performed even better than the intraspecific crosses. Very weak postmating reproductive barriers were observed between our study species and may explain the frequent occurrence of first-generation hybrids in mixed Dactylorhiza populations. Germination failure, which is regarded as one of the most important bottlenecks in the orchid life cycle, was not important for reproductive isolation.

  12. [Study protocol on the effect of the economic crisis on mortality and reproductive health and health inequalities in Spain].

    Science.gov (United States)

    Pérez, Glòria; Gotsens, Mercè; Palència, Laia; Marí-Dell'Olmo, Marc; Domínguez-Berjón, M Felicitas; Rodríguez-Sanz, Maica; Puig, Vanessa; Bartoll, Xavier; Gandarillas, Ana; Martín, Unai; Bacigalupe, Amaia; Díez, Elia; Ruiz, Miguel; Esnaola, Santiago; Calvo, Montserrat; Sánchez, Pablo; Luque Fernández, Miguel Ángel; Borrell, Carme

    The aim is to present the protocol of the two sub-studies on the effect of the economic crisis on mortality and reproductive health and health inequalities in Spain. Substudy 1: describe the evolution of mortality and reproductive health between 1990 and 2013 through a longitudinal ecological study in the Autonomous Communities. This study will identify changes caused by the economic crisis in trends or reproductive health and mortality indicators using panel data (17 Autonomous Communities per study year) and adjusting Poisson models with random effects variance. Substudy 2: analyse inequalities by socioeconomic deprivation in mortality and reproductive health in several areas of Spain. An ecological study analysing trends in the pre-crisis (1999-2003 and 2004-2008) and crisis (2009-2013) periods will be performed. Random effects models Besag York and Mollié will be adjusted to estimate mortality indicators softened in reproductive health and census tracts. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  13. Effects of fluoxetine on the reproduction of two prosobranch mollusks: Potamopyrgus antipodarum and Valvata piscinalis

    International Nuclear Information System (INIS)

    Gust, M.; Buronfosse, T.; Giamberini, L.; Ramil, M.; Mons, R.; Garric, J.

    2009-01-01

    Fluoxetine is a widely used antidepressant, frequently found in aquatic ecosystems. We investigated its effects on two freshwater prosobranch gastropods: Valvata piscinalis (European valve snail) and Potamopyrgus antipodarum (New Zealand mudsnail), which have different reproductive modes. The fecundity of V. piscinalis (cumulate number of eggs at day 42) was not affected with an NOEC of 100 μg/L nominal concentration (69 μg/L measured concentration). The mudsnail P. antipodarum responded in a biphasic dose-effect curve at low concentrations. The cumulate number of neonates at day 42 had an LOEC of 100 μg/L (69 μg/L) and an NOEC of 33.3 μg/L (13 μg/L), whereas the embryos in the brood pouch at day 42 only showed an LOEC of 3.7 μg/L (1 μg/L). We also observed histological effects in P. antipodarum (gonadal thickness). Among the sexual steroids we measured only testosterone which varied, independent of reproduction. Moreover the use of two closely related species highlights the interspecific variability. - Fluoxetine has significant effects on the reproduction and development of some freshwater snails

  14. Effects of fluoxetine on the reproduction of two prosobranch mollusks: Potamopyrgus antipodarum and Valvata piscinalis

    Energy Technology Data Exchange (ETDEWEB)

    Gust, M. [Laboratoire d' ecotoxicologie, Cemagref, 3b quai Chauveau, CP 220, 69336 Lyon Cedex 09 (France)], E-mail: marion.gust@cemagref.fr; Buronfosse, T. [Laboratoire d' endocrinologie, Ecole Nationale Veterinaire de Lyon, avenue Bourgelat, 69280 Marcy l' Etoile (France)], E-mail: thierry.buronfosse@inserm.fr; Giamberini, L. [Laboratoire des interactions Ecotoxicologie, Biodiversite, Ecosystemes, CNRS UMR 7146, campus Bridoux, 57000 Metz (France)], E-mail: giamb@sciences.univ-metz.fr; Ramil, M. [Federal Institute of Hydrology (BFG), D-56068 Koblenz, Am Mainzer Tor 1 (Germany)], E-mail: mramil@usc.es; Mons, R. [Laboratoire d' ecotoxicologie, Cemagref, 3b quai Chauveau, CP 220, 69336 Lyon Cedex 09 (France)], E-mail: raphael.mons@cemagref.fr; Garric, J. [Laboratoire d' ecotoxicologie, Cemagref, 3b quai Chauveau, CP 220, 69336 Lyon Cedex 09 (France)], E-mail: jeanne.garric@cemagref.fr

    2009-02-15

    Fluoxetine is a widely used antidepressant, frequently found in aquatic ecosystems. We investigated its effects on two freshwater prosobranch gastropods: Valvata piscinalis (European valve snail) and Potamopyrgus antipodarum (New Zealand mudsnail), which have different reproductive modes. The fecundity of V. piscinalis (cumulate number of eggs at day 42) was not affected with an NOEC of 100 {mu}g/L nominal concentration (69 {mu}g/L measured concentration). The mudsnail P. antipodarum responded in a biphasic dose-effect curve at low concentrations. The cumulate number of neonates at day 42 had an LOEC of 100 {mu}g/L (69 {mu}g/L) and an NOEC of 33.3 {mu}g/L (13 {mu}g/L), whereas the embryos in the brood pouch at day 42 only showed an LOEC of 3.7 {mu}g/L (1 {mu}g/L). We also observed histological effects in P. antipodarum (gonadal thickness). Among the sexual steroids we measured only testosterone which varied, independent of reproduction. Moreover the use of two closely related species highlights the interspecific variability. - Fluoxetine has significant effects on the reproduction and development of some freshwater snails.

  15. Study on reproduction of captive marine mammals.

    Science.gov (United States)

    Katsumata, Etsuko

    2010-02-01

    The reproductive endocrinological characteristics of beluga, killer whale, spotted seal and bottlenose dolphin were evaluated and used in conjunction with applied reproductive research to enhance captive breeding programs. Results from 8 y of biweekly serum progesterone determination in a female beluga indicated that sexual maturity occured at approximately age 13, two to seven estrous cycles, lasting 37 +/- 3.9 days, per yr began in April-May every year. Rectal temperature was positively correlated with serum progesterone levels and negatively associated with behavioral estrus. In five cases of pregnancy of two female killer whale, positive relationship was found between serum progesterone concentration and temperature during the first period of 18 month-gestation. In the normal parturitions (n=4), rectal temperature decreased 0.8 C lower than average rectal temperature during pregnancy. Sexual maturity of female killer whales occurred at age nine. Yearly contraception in the mono-estrus captive spotted seals (n=10) using a single dose of the progestagen (proligestone(TM); 5 or 10 mg/kg s.c.) was achieved in 94% (33/35) of the attempts over 5 yr when the hormone was administered two months prior to the breeding season. Artificial insemination trials (n=4) were conducted in female bottlenose dolphin (n=3) using fresh and frozen-thawed semen. Estrus synchronization using regumate (27 days) resulted in ovulation occurring 19 to 24 days post withdrawal. Conception was confirmed in 75% of the attempts, with two females successfully delivering calves.

  16. Reproduction numbers of infectious disease models

    Directory of Open Access Journals (Sweden)

    Pauline van den Driessche

    2017-08-01

    Full Text Available This primer article focuses on the basic reproduction number, ℛ0, for infectious diseases, and other reproduction numbers related to ℛ0 that are useful in guiding control strategies. Beginning with a simple population model, the concept is developed for a threshold value of ℛ0 determining whether or not the disease dies out. The next generation matrix method of calculating ℛ0 in a compartmental model is described and illustrated. To address control strategies, type and target reproduction numbers are defined, as well as sensitivity and elasticity indices. These theoretical ideas are then applied to models that are formulated for West Nile virus in birds (a vector-borne disease, cholera in humans (a disease with two transmission pathways, anthrax in animals (a disease that can be spread by dead carcasses and spores, and Zika in humans (spread by mosquitoes and sexual contacts. Some parameter values from literature data are used to illustrate the results. Finally, references for other ways to calculate ℛ0 are given. These are useful for more complicated models that, for example, take account of variations in environmental fluctuation or stochasticity. Keywords: Basic reproduction number, Disease control, West Nile virus, Cholera, Anthrax, Zika virus

  17. Bisphenol A in Reproduction: Epigenetic Effects.

    Science.gov (United States)

    Chianese, Rosanna; Troisi, Jacopo; Richards, Sean; Scafuro, Marika; Fasano, Silvia; Guida, Maurizio; Pierantoni, Riccardo; Meccariello, Rosaria

    2018-02-21

    Bisphenol A (BPA) is an endocrine disrupting chemical widely used in the manufacture of polycarbonate plastic and epoxy resin to produce a multitude of consumer products, food and drink containers, and medical devices. BPA is similar to estradiol in structure and thus interferes in steroid signalling with different outcomes on reproductive health depending on doses, life stage, mode, and timing of exposure. In this respect, it has an emerging and controversial role as a "reproductive toxicant" capable of inducing short and long-term effects including the modulation of gene expression through epigenetic modification (i.e. methylation of CpG islands, histone modifications and production of non-coding RNA) with direct and trans-generational effects on exposed organisms and their offspring, respectively. This review provides an overview about BPA effects on reproductive health and aims to summarize the epigenetic effects of BPA in male and female reproduction. BPA exerts epigenetic effects in both male and female reproduction. In males, BPA affects spermatogenesis and sperm quality and possible trans-generational effects on the reproductive ability of the offspring. In females, BPA affects ovary, embryo development, and gamete quality for successful in vivo and in vitro fertilization (IVF). The exact mechanisms of BPA-mediated effects in reproduction are not fully understood; however, the environmental exposure to BPA - especially in fetal and neonatal period - deserves attention to preserve the reproductive ability in both sexes and to reduce the epigenetic risk for the offspring. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. Effects of an accidental dry-season fire on the reproductive phenology of two Neotropical savanna shrubs.

    Science.gov (United States)

    Dodonov, P; Zanelli, C B; Silva-Matos, D M

    2017-10-30

    Fire is a recurrent disturbance in savanna vegetation and savanna species are adapted to it. Even so, fire may affect various aspects of plant ecology, including phenology. We studied the effects of a spatially heterogeneous fire on the reproductive phenology of two dominant woody plant species, Miconia albicans (Melastomataceae) and Schefflera vinosa (Araliaceae), in a savanna area in South-eastern Brazil. The study site was partially burnt by a dry-season accidental fire in August 2006, and we monitored the phenolology of 30 burnt and 30 unburnt individuals of each species between September 2007 and September 2008. We used restricted randomizations to assess phenological differences between the burnt and unburnt individuals. Fire had negative effects on the phenology of M. albicans, with a smaller production of reproductive structures in general and of floral buds, total fruits, and ripe fruits in burnt plants. All unburnt but only 16% of the burnt M. albicans plants produced ripe fruits during the study. Fire effects on S. vinosa were smaller, but there was a greater production of floral buds and fruits (but not ripe fruits) by burnt plants; approximately 90% of the individuals of S. vinosa produced ripe fruits during the study, regardless of having been burnt or not. The differences between the two species may be related to S. vinosa's faster growth and absence from the seed bank at the study site, whereas M. albicans grows more slowly and is dominant in the seed bank.

  19. Deciphering the Costs of Reproduction in Mango – Vegetative Growth Matters

    Science.gov (United States)

    Capelli, Mathilde; Lauri, Pierre-Éric; Normand, Frédéric

    2016-01-01

    Irregular fruit production across successive years is a major issue that limits the profitability of most temperate and tropical fruit crops. It is particularly affected by the reciprocal relationships between vegetative and reproductive growth. The concept of the costs of reproduction is defined in terms of losses in the potential future reproductive success caused by current investment in reproduction. This concept, developed in ecology and evolutionary biology, could provide a methodological framework to analyze irregular bearing in fruit crops, especially in relation to the spatial scale at which studies are done. The objective of this study was to investigate the direct effects of reproduction during a growing cycle on reproduction during the following growing cycle and the indirect effects through vegetative growth between these two reproductive events, for four mango cultivars and during two growing cycles. Two spatial scales were considered: the growth unit (GU) and the scaffold branch. Costs of reproduction were detected between two successive reproductive events and between reproduction and vegetative growth. These costs were scale-dependent, generally detected at the GU scale and infrequently at the scaffold branch scale, suggesting partial branch autonomy with respect to processes underlying the effects of reproduction on vegetative growth. In contrast, the relationships between vegetative growth and reproduction were positive at the GU scale and at the scaffold branch scale in most cases, suggesting branch autonomy for the processes, mainly local, underlying flowering and fruiting. The negative effect of reproduction on vegetative growth prevailed over the positive effect of vegetative growth on the subsequent reproduction. The costs of reproduction were also cultivar-dependent. Those revealed at the GU scale were related to the bearing behavior of each cultivar. Our results put forward the crucial role of vegetative growth occurring between two

  20. Sex recombination, and reproductive fitness: an experimental study using Paramecium

    Energy Technology Data Exchange (ETDEWEB)

    Nyberg, D.

    1982-08-01

    The effect of sex and recombination on reproductive fitness are measured using five wild stocks of Paramecium primaurelia. Among the wild stocks there were highly significant differences in growth rates. No hybrid had as low a fitness as the least fit parental stock. Recombination produced genotypes of higher fitness than those of either parent only in the cross between the two stocks of lowest fitness. The increase in variance of fitness as a result of recombination was almost exclusively attributable to the generation lines with low fitness. The fitness consequences of sexuality and mate choice were stock specific; some individuals leaving the most descendants by inbreeding, others by outcrossing. For most crosses the short-term advantage of sex, if any, accrue from the fusion of different gametes (hybrid vigor) and not from recombination. Since the homozygous genotype with the highest fitnes left the most progeny by inbreeding (no recombination), the persistence of conjugation in P. primaurelia is paradoxical. (JMT)

  1. Experimental study of single- and two-phase flow fields around PWR steam generator tube support plates

    International Nuclear Information System (INIS)

    Bates, J.M.; Stewart, C.W.

    1979-08-01

    Laser-Doppler anemometry (LDA) was used to measure local mean axial velocities and turbulence intnsities at selected locations within a study model dimensionally protypic of an existing PWR steam generator design. The model tube bundle with support plate was installed in a special flow housing that formed part of an isothermal recirculating water flow loop. Flow conditions for this experiment were intended to simulate only typical single-phase flow velocities and were not an attempt to completely model actual steam generator, boiling, two-phase flow conditions. The measurements were performed in water at approximately 85 0 F with test section average velocities of approximately 0.55 and 1.1 fps. These conditions corresponded to Reynolds numbers of approximately 7,000 and approximately 14,000, respectively. Normalized velocity and turbulence intensity ratios are graphically reported. Additional qualitative, photographic investigations of air-water two-phase flows in a PWR steam generator study model were also performed

  2. Child-Rearing Practices of Two Generations of Punjabi Parents.

    Science.gov (United States)

    Dosnajh, J. S.; Ghuman, P. A. S.

    1997-01-01

    Studied contrasts in child-rearing practices between two generations of Punjabi parents living in England, and between Punjabis and white parents. Collected data on topics such as breast-feeding, cot deaths, and father participation, through in-depth interviews of the first generation (1970) and second generation (1995). Found second-generation…

  3. Reproductive autonomy: A case study

    Directory of Open Access Journals (Sweden)

    David R Hall

    2016-11-01

    Full Text Available Reproductive autonomy (RA has been challenged by the availability of genetic information, disability and the ethics of selective reproduction. Utilitarian and rights-based approaches, as well as procreative beneficence (PB fail to provide compelling reasons for infringing RA, and may even be likened to dangerous eugenics. Parents are not morally obliged to prevent the birth of a disabled child. Society should rather adopt inclusivity, recognising and providing persons with disabilities opportunities for capability and worthwhile lives.

  4. Reproductive strategies and colonizing ability of two sympatric epiphytic bromeliads in a tropical premontane area

    NARCIS (Netherlands)

    Cascante Marin, A.M.; de Jong, M.; Borg, E.D.; Oostermeijer, J.G.B.; Wolf, J.H.D.; den Nijs, J.C.M.

    2006-01-01

    Predispersal characteristics that affect the reproductive success in plants may influence their colonizing ability. We evaluated this hypothesis in two sympatric epiphytic bromeliads in Costa Rica, Guzmania monostacbia and Tillandsia fasciculata, that show contrasting levels of local seedling

  5. An analysis of two indigenous reproductive health illnesses in a Nahua community in Veracruz, Mexico

    Directory of Open Access Journals (Sweden)

    Smith-Oka Vania

    2012-08-01

    Full Text Available Abstract Background This article describes the local concepts indigenous Nahua women hold regarding their reproduction. Specifically it provides a description of two indigenous illnesses—isihuayo and necaxantle, it discusses their etiology, symptoms, and treatments, and it analyzes them within the local ethnomedical framework and sociopolitical context. A perception of female vulnerability is shown to be an underlying shaper of women’s experiences of these illnesses. Methods This research took place in a small Nahua village in Mexico. Qualitative data on local perceptions of these illnesses were collected by a combination of participant observation and interviews. Ethnobotanical data was obtained through interviews, and medicinal plants were collected in home gardens, fields, stream banks, and forested areas. The total study population consisted of traditional birth attendants (N = 5, clinicians (N = 8, and laywomen (N = 48. Results Results showed that 20% of the village women had suffered from one or both of these illnesses. The article includes a detailed description of the etiology, symptoms, and treatments of these illnesses. Data shows that they were caused by mechanical, physical, and social factors related to a woman’s weakness and/or lack of support. Traditional birth attendants often treated women’s illnesses. Five medicinal plants were salient in the treatment of these illnesses: Ocimum basilicum L., Mentzelia aspera L., Pedilanthus tithymaloides (L. Poit., and Piper umbellatum L. were used for isihuayo, while Solanum wendlandii Hook f. was used for necaxantle. Conclusions The research on these two ethnomedical conditions is a useful case study to understanding how indigenous women experience reproductive health. Reproductive health is not simply about clinically-based medicine but is also about how biomedicine intersects with the local bodily concepts. By describing and analyzing indigenous women’s ill health, one can focus

  6. Two general models that generate long range correlation

    Science.gov (United States)

    Gan, Xiaocong; Han, Zhangang

    2012-06-01

    In this paper we study two models that generate sequences with LRC (long range correlation). For the IFT (inverse Fourier transform) model, our conclusion is the low frequency part leads to LRC, while the high frequency part tends to eliminate it. Therefore, a typical method to generate a sequence with LRC is multiplying the spectrum of a white noise sequence by a decaying function. A special case is analyzed: the linear combination of a smooth curve and a white noise sequence, in which the DFA plot consists of two line segments. For the patch model, our conclusion is long subsequences leads to LRC, while short subsequences tend to eliminate it. Therefore, we can generate a sequence with LRC by using a fat-tailed PDF (probability distribution function) of the length of the subsequences. A special case is also analyzed: if a patch model with long subsequences is mixed with a white noise sequence, the DFA plot will consist of two line segments. We have checked known models and actual data, and found they are all consistent with this study.

  7. Trans-generational effects induced by alpha and gamma ionizing radiations at Daphnia magna

    International Nuclear Information System (INIS)

    Parisot, Florian

    2015-01-01

    Anthropogenic activities related to the nuclear industry contribute to continuous discharges of radionuclides into terrestrial and aquatic ecosystems. Over the past decades, the ecological risk of ionizing radiation has become a growing public, regulatory and scientific concern for ecosystems protection. Until recently, only few studies focus on exposure situations at low doses of irradiation, although these situations are representative of realistic environmental conditions. Understanding how ionizing radiation affects species over several generations and at various levels of biological organization is a major research goal in radioecology. The aim of this PhD was to bring new knowledge on the effects of ionizing radiation during a multi-generational expose of the aquatic invertebrate, Daphnia magna. A two-step strategy was implemented. First, an external gamma radiation at environmentally relevant dose rates was performed on D. magna over three successive generations (F0, F1 and F2). The objective of this experiment was to examine whether low dose rates of radiation induced increasing effects on survival, growth and reproduction of daphnids over generations and to test a possible accumulation and transmission of DNA alterations from adults to offspring. Results showed an accumulation and a transmission of DNA alterations over generations, together with an increase in effect severity on growth and reproduction from generation F0 to generation F2. Transiently more efficient DNA repair leading to some recovery at the organism level was suggested in generation F1. Second, data from the external gamma irradiation and those from an earlier study of internal alpha contamination were analyzed with DEBtox models (Dynamic Energy Budget applied to toxicology), to identify and compare the causes of the trans-generational increase in effect severity between the two types of radiation. In each case, two distinct metabolic modes of action were necessary to explain effects on

  8. A systematic study of binaural reproduction systems through loudspeakers

    DEFF Research Database (Denmark)

    Lacouture Parodi, Yesenia

    This Ph.D. thesis presents an investigation of the acoustical and psycho-acoustical characteristics of binaural reproduction systems through loudspeakers. The study was mainly focused on the characteristics of closely spaced loudspeakers – known as stereo-dipoles – when placed at different...... positions, e.g. in front of, above or in the back of the head. The main objective of this study is to set foundations for the design of a binaural reproduction system that is robust to head rotations and reduces front-back confusions. Different crosstalk cancellation techniques were investigated...... when the loudspeakers are placed above the head and that closely spaced loudspeakers are more robust to lateral displacements than wider span angles. Based on the results obtained from those experiments, a binaural reproduction system that uses three stereo-dipoles is proposed: one pair in front...

  9. From esterilología to reproductive biology: The story of the Mexican assisted reproduction business.

    Science.gov (United States)

    González-Santos, Sandra P

    2016-06-01

    This paper provides the first overview of how assisted reproduction emerged and developed in Mexico. In doing so it addresses two broad points: when and how treatments using assisted reproductive technology became common practice within reproductive medicine; and how the Mexican assisted reproduction industry emerged. The paper begins in 1949, when the first medical association dedicated to esterilología - the biomedical area focused on the study of infertility - was established, thus providing the epistemic and professional ground upon which assisted reproductive technology would later thrive. The paper then traces the way in which this biomedical industry developed, from individual doctors in their practices to networks of clinics and from a clinical practice to a reproductive industry. It also describes the different ways in which the professional community and the government have worked towards developing a regulatory frame for the practice of assisted reproduction. The paper is informed by ethnographic work conducted at clinics, conferences, online forums and websites, as well as by analysis of the contemporary national media, government documents and national medical journals from the early mid-twentieth century to the those published today.

  10. Response to multi-generational selection under elevated [CO2] in two temperature regimes suggests enhanced carbon assimilation and increased reproductive output in Brassica napus L

    DEFF Research Database (Denmark)

    Frenck, Georg; van der Linden, Leon; Mikkelsen, Teis Nørgaard

    2013-01-01

    different temperature regimes. To reveal phenotypic divergence at the manipulated [CO2] and temperature conditions, a full-factorial natural selection regime was established in a phytotron environment over the range of four generations. It is demonstrated that a directional response to selection at elevated......Functional plant traits are likely to adapt under the sustained pressure imposed by environmental changes through natural selection. Employing Brassica napus as a model, a multi-generational study was performed to investigate the potential trajectories of selection at elevated [CO2] in two...... subjected to increased levels of CO2 over the generational range investigated. The results of this study suggest that phenotypic divergence of plants selected under elevated atmospheric CO2 concentration may drive the future functions of plant productivity to be different from projections that do...

  11. Dynamical generation of maximally entangled states in two identical cavities

    International Nuclear Information System (INIS)

    Alexanian, Moorad

    2011-01-01

    The generation of entanglement between two identical coupled cavities, each containing a single three-level atom, is studied when the cavities exchange two coherent photons and are in the N=2,4 manifolds, where N represents the maximum number of photons possible in either cavity. The atom-photon state of each cavity is described by a qutrit for N=2 and a five-dimensional qudit for N=4. However, the conservation of the total value of N for the interacting two-cavity system limits the total number of states to only 4 states for N=2 and 8 states for N=4, rather than the usual 9 for two qutrits and 25 for two five-dimensional qudits. In the N=2 manifold, two-qutrit states dynamically generate four maximally entangled Bell states from initially unentangled states. In the N=4 manifold, two-qudit states dynamically generate maximally entangled states involving three or four states. The generation of these maximally entangled states occurs rather rapidly for large hopping strengths. The cavities function as a storage of periodically generated maximally entangled states.

  12. studies on the reproductive status, catch and age compositions of ...

    African Journals Online (AJOL)

    ADMIN

    reproductive status of samples of Glossina pallidipes, trapped in NGU-2G traps. The objective was to assess ... male flies. Key words/phrases: Abortion, age reproductive status, Glossina pallidipes, NGU-2G traps, pregnancy. INTRODUCTION. From an ... ecology and behaviour of G. pallidipies. The present study was, ...

  13. Spatiotemporal variation in the reproductive ecology of two parapatric subspecies of Oenothera cespitosa (Onagraceae).

    Science.gov (United States)

    Artz, Derek R; Villagra, Cristian A; Raguso, Robert A

    2010-09-01

    • Flowering plants that rely on pollinators for most of their reproduction may experience unpredictable and inconsistent availability of effective pollinators throughout their reproductive lifetime. We investigated the reproductive ecology of two subspecies of the tufted evening primrose, Oenothera cespitosa, which occupy geographically and edaphically distinct habitats in western North America: O. cespitosa subsp. navajoensis inhabits sandstone soils on open sites or rocky slopes in the Colorado Plateau and O. cespitosa subsp. cespitosa grows in clay soils on talus slopes and exposed rocky ridges in the western Great Plains and northern Rocky Mountains of the United States. • Pollen augmentation and selfing experiments, floral visitor observations, and single-visit effectiveness experiments were conducted over 4 years to examine the breeding system and spatiotemporal variation in pollinator behavior, assemblage, and abundance at different populations for each subspecies. • Both subspecies of O. cespitosa were self-incompatible and pollen-limited, suggesting that the relative abundance, effectiveness, and movement patterns of different insects as pollinators influenced the quality and quantity of seed production in these plants. Medium-sized vespertine hawkmoths (Hyles lineata, Sphinx vashti) were effective pollinators when present, as were large matinal bees (Anthophora affabilis, A. dammersi, Xylocopa tabaniformis androleuca), whereas small oligolectic Lasioglossum bees primarily functioned as pollen thieves in the evening and morning. • These findings highlight the importance of variability of pollinator composition and abundance in the evolution of plant breeding systems and reproductive success at varying spatial and temporal scales.

  14. Awareness and Attitude towards Breastfeeding among Two Generations of Indian Women: A Comparative Study.

    Science.gov (United States)

    Pandey, Deeksha; Sardana, Parnita; Saxena, Aashish; Dogra, Luvdeep; Coondoo, Ambika; Kamath, Asha

    2015-01-01

    Present study was aimed to analyze the impact of education, employment and financial independence in breastfeeding practices among Indian women. Present explorative questionnaire based survey included 256 women (128 pairs) in the final analysis. A pair means--a) pregnant lady (in her third trimester) representing younger generation and b) her mother/mother in law representing the elder generation. We found that the overall awareness regarding 'breast milk' being the best food for baby was excellent (overall 97.3%; younger generation: 96.9%; elder generation: 97.7%). Overall knowledge regarding the correct technique (28.9% younger generation and 21.9% elder generation) and frequency of breastfeeding (20.3% of younger generation and 34.4% of elder generation) was very poor. Less than 60% (younger generation: 57.8%; elder generation: 58.6%) were aware that the only major contraindication for breastfeeding is a mother infected with human immunodeficiency virus (HIV). On comparing responses obtained from the two generations of women, difference was not statistically significant among most of the issues related to breastfeeding. With regards to the attitude, despite better awareness, only 94.5% women in younger generation and 89.1% women in elder generation were planning to give mother's milk as the first feed to the newborn. Similarly, less than 75% of women were ready to breast-feed the newborn immediately after birth. This was contradictory to the fact that 86% of pregnant women were aware that the baby should be breast-fed within an hour of birth. Awareness with regards to breastfeeding issues had not changed significantly with the educational progress of Indian women. Despite the good level of awareness in the society regarding breastfeeding, attitude to practice the same is lacking.

  15. Is Boric Acid Toxic to Reproduction in Humans? Assessment of the Animal Reproductive Toxicity Data and Epidemiological Study Results.

    Science.gov (United States)

    Duydu, Yalçın; Başaran, Nurşen; Ustündağ, Aylin; Aydın, Sevtap; Undeğer, Ulkü; Ataman, Osman Yavuz; Aydos, Kaan; Düker, Yalçın; Ickstadt, Katja; Waltrup, Brita Schulze; Golka, Klaus; Bolt, Hermann Maximilian

    2016-01-01

    Boric acid and sodium borates are classified as toxic to reproduction in the CLP Regulation under "Category 1B" with the hazard statement of "H360FD". This classification is based on the reprotoxic effects of boric acid and sodium borates in animal experiments at high doses. However, boron mediated reprotoxic effects have not been proven in epidemiological studies so far. The epidemiological study performed in Bandırma boric acid production plant is the most comprehensive published study in this field with 204 voluntarily participated male workers. Sperm quality parameters (sperm morphology, concentration and motility parameters), FSH, LH and testosterone levels were determined in all participated employees as the reproductive toxicity biomarkers of males. However, boron mediated unfavorable effects on reproduction in male workers have not been determined even in the workers under very high daily boron exposure (0.21 mg B/kg-bw/day) conditions. The NOAEL for rat reproductive toxicity is equivalent to a blood boron level of 2020 ng/g. This level is higher than the mean blood boron concentration (223.89 ± 69.49 ng/g) of the high exposure group workers in Bandırma boric acid production plant (Turkey) by a factor of 9. Accordingly, classifying boric acid and sodium borates under "Category 1B" as "presumed reproductive human toxicant in the CLP regulation seems scientifically not reasonable. The results of the epidemiological studies (including the study performed in China) support for a down-classification of boric acid from the category 1B, H360FD to category 2, H361d, (suspected of damaging the unborn child).

  16. Occupational reproductive epidemiology: Pt. 1

    International Nuclear Information System (INIS)

    Roman, Eve; Doyle, Pat

    1993-01-01

    The authors review the current state of knowledge about possible adverse effects of hazardous paternal workplace exposures on human reproduction is scant. The methodology for studying possible association between occupational exposures and adverse reproductive events is not well developed. More detailed laboratory and epidemiological research is clearly required, and better collaboration between these two disciplines is needed. Associations suggested in the course of epidemiological research need to be tested in the laboratory, and vice versa. (author)

  17. Reproductive effort accelerates actuarial senescence in wild birds : An experimental study

    NARCIS (Netherlands)

    Boonekamp, Jelle J.; Salomons, Martijn; Bouwhuis, Sandra; Dijkstra, Cornelis; Verhulst, Simon

    Optimality theories of ageing predict that the balance between reproductive effort and somatic maintenance determines the rate of ageing. Laboratory studies find that increased reproductive effort shortens lifespan, but through increased short-term mortality rather than ageing. In contrast, high

  18. Reproductive life of Bhoksa women.

    Science.gov (United States)

    Garg, S K; Tyagi, D; Sankhyan, A R

    1981-01-01

    The paper discusses the reproductive life of 111 ever-married Bhoksa women. The mean age at marriage for women of all ages among Bhoksas, like other tribal populations, is high, unlike the caste populations. The mean ages at first birth of the pooled sample and of the completed fertility cases suggest late and early marriages of the older and younger generations. The maximum number of marriages occur between 15 and 19 years and of first births between 16 and 20 years. Percentage of reproductive wastage is high in both the lower and higher age groups. Young mothers with low birth orders and older mothers with high birth orders display a high frequency of reproductive wastage. Evidently, both birth order and the age of the mother have effects on reproductive wastage. Average number of children ever born (including stillbirth but not abortion or miscarriage) per mother of all ages is the highest among Bhoksas of all the studied ethnic groups of India. The Bhoksa, like caste populations, show a high number of children ever born per mother of completed fertility. Quite a high masculinity in the secondary sex ratio, like other mongoloid population is noticed. The contribution of mortality component to the Total Index of Opportunity for Selection is more than that of the fertility component. Bhoksas conform to the general low range of net reproductive index, which is however greater than unity, suggesting that they are in a growth stage.

  19. Two Prospective Studies of Changes in Stress Generation across Depressive Episodes in Adolescents and Emerging Adults

    Science.gov (United States)

    Morris, Matthew C.; Kouros, Chrystyna D.; Hellman, Natalie; Rao, Uma; Garber, Judy

    2014-01-01

    The stress generation hypothesis was tested in two different longitudinal studies examining relations between weekly depression symptom ratings and stress levels in adolescents and emerging adults at varied risk for depression. Participants in Study 1 included 240 adolescents who differed with regard to their mother’s history of depressive disorders. Youth were assessed annually across 6 years (Grades 6 through 12). Consistent with the depression autonomy model, higher numbers of prior major depressive episodes (MDEs) were associated with weaker stress generation effects, such that higher levels of depressive symptoms predicted increases in levels of dependent stressors for adolescents with ≤ 2 prior MDEs, but depressive symptoms were not significantly related to dependent stress levels for youth with ≥ 3 prior MDEs. In Study 2, participants were 32 remitted-depressed and 36 never-depressed young adults who completed a psychosocial stress task to determine cortisol reactivity and were re-assessed for depression and stress approximately eight months later. Stress generation effects were moderated by cortisol responses to a laboratory psychosocial stressor, such that individuals with higher cortisol responses exhibited a pattern consistent with the depression autonomy model, whereas individuals with lower cortisol responses showed a pattern more consistent with the depression sensitization model. Finally, comparing across the two samples, stress generation effects were weaker for older participants and for those with more prior MDEs. The complex, multi-factorial relation between stress and depression is discussed. PMID:25422968

  20. Reproduction Symposium: developmental programming of reproductive and metabolic health.

    Science.gov (United States)

    Padmanabhan, V; Veiga-Lopez, A

    2014-08-01

    Inappropriate programming of the reproductive system by developmental exposure to excess steroid hormones is of concern. Sheep are well suited for investigating developmental origin of reproductive and metabolic disorders. The developmental time line of female sheep (approximately 5 mo gestation and approximately 7 mo to puberty) is ideal for conducting sequential studies of the progression of metabolic and/or reproductive disruption from the developmental insult to manifestation of adult consequences. Major benefits of using sheep include knowledge of established critical periods to target adult defects, a rich understanding of reproductive neuroendocrine regulation, availability of noninvasive approaches to monitor follicular dynamics, established surgical approaches to obtain hypophyseal portal blood for measurement of hypothalamic hormones, and the ability to perform studies in natural setting thereby keeping behavioral interactions intact. Of importance is the ability to chronically instrument fetus and mother for determining early endocrine perturbations. Prenatal exposure of the female to excess testosterone (T) leads to an array of adult reproductive disorders that include LH excess, functional hyperandrogenism, neuroendocrine defects, multifollicular ovarian morphology, and corpus luteum dysfunction culminating in early reproductive failure. At the neuroendocrine level, all 3 feedback systems are compromised. At the pituitary level, gonadotrope (LH secretion) sensitivity to GnRH is increased. Multifollicular ovarian morphology stems from persistence of follicles as well as enhanced follicular recruitment. These defects culminate in progressive loss of cyclicity and reduced fecundity. Prenatal T excess also leads to fetal growth retardation, an early marker of adult reproductive and metabolic diseases, insulin resistance, hypertension, and behavioral deficits. Collectively, the reproductive and metabolic deficits of prenatal T-treated sheep provide proof of

  1. Effects of gamma irradiation on reproductive traits in Apis mellifera (honey bee)

    International Nuclear Information System (INIS)

    Shameer, P.M.; Harini, B.P.; Shetty, N.J.; Chaubey, R.C.; Jha, S.K.

    2013-01-01

    Apis mellifera (honey bee) is ecologically and economically important hymenopterous insect. They are important pollinators in agricultural, urban and natural landscapes. Hundreds of millions of dollars are generated through the sale of hive products such as honey, wax, pollen, propolis, royal jelly and venom. Radiation leakage can cause harmful effect on human and non human biota. Honey bee can be very sensitive to such hazards. FASSET (Framework for Assessment of Environmental impacT) recommended A. melliferra as a model organism for the studies of effects of radiation. In order to study the effects of radiation, 1-2 month old mated queens were exposed to various doses of gamma radiation including 1Gy, 2Gy, 3Gy, 10Gy, 20Gy, 30Gy, 40Gy and 50Gy and its effects on reproductive traits such as fecundity, hatchability, sealed brood formation, adult emergence and fertility were studied. The data generated from such experiments were compared with non irradiated samples of the same age for two weeks before and after irradiation. Results showed that fecundity, hatchability and fertility were significantly reduced 3Gy dose onwards when compared to control. An inverse relation between reproductive traits and radiation doses were observed. Dose response curve were constructed with respect to reduction in hatchability and fertility. (author)

  2. [State of the reproductive systemin in male rats of 1st generation obtained from irradiated parents and exposed to electromagnetic radiation (897 MHz) during embryogenesis and postnatal development].

    Science.gov (United States)

    Vereshchako, G G; Chueshova, N V; Gorokh, G A; Naumov, A D

    2014-01-01

    The consequences of prolonged exposure to electromagnetic radiation from cellular phone (897 MHz, daily 8 h/day) in male rats of the 1st generation obtained from irradiated parents and subjected to prolonged exposure to electromagnetic radiation of the range of mobile communications during ontogeny and postnatal development were studied. It has been found that irradiation causes a decrease in the number of births of animals, changing the sex ratio towards the increase in the number of males. It had a significant impact on the reproductive system of males, accelerating their sexual development, revealed at the age of two months. Radiation from cell phones led to significant disproportions in the cell number at different stages of spermatogenesis. It increased the number of mature spermatozoa which decreased viability.

  3. Development and Application of a Two-Tier Multiple-Choice Diagnostic Test for High School Students' Understanding of Cell Division and Reproduction

    Science.gov (United States)

    Sesli, Ertugrul; Kara, Yilmaz

    2012-01-01

    This study involved the development and application of a two-tier diagnostic test for measuring students' understanding of cell division and reproduction. The instrument development procedure had three general steps: defining the content boundaries of the test, collecting information on students' misconceptions, and instrument development.…

  4. Partial Results Regarding the Genetic Analysis of Thoroughbred Horse from Cislău Studfarm: Reproductive Isolation and Age Structure

    Directory of Open Access Journals (Sweden)

    Marius Maftei

    2011-05-01

    Full Text Available This study is a part of an ample research concerning the genetic analysis (history of Thoroughbred horses from Cislău studfarm. The genetic analysis studies are a part of Animal Genetic Resources Management because just start of them we elaborate the strategies for inbreeding management. This study has as purpose to present two important aspects of genetic analysis: reproductive isolation level and age structure.This parameters has a capital importance in animal breeding because there has a directly influence in animal population evolution. The reproductive isolation situation was quantified using the relation elaborated by S. Wright in 1921. The age structure situation is based on the age distribution histogram. The analysis showed that the Nonius horse from Izvin stud is a reproductively isolated population and have its own evolutionary path. Age structure is not balanced with negative repercurssions on generation interval.

  5. In- and outdoor reproduction of first generation common sole Solea solea under a natural photothermal regime: Temporal progression of sexual maturation assessed by monitoring plasma steroids and gonadotropin mRNA expression.

    Science.gov (United States)

    Palstra, A P; Blok, M C; Kals, J; Blom, E; Tuinhof-Koelma, N; Dirks, R P; Forlenza, M; Blonk, R J W

    2015-09-15

    Reproduction of many temperate fishes is seasonal and maturation and spawning of gametes are under photothermal control. Reproductive success of first generation (G1) common sole Solea solea in captivity has been low. In this study, the sexual maturation status has been assessed during the prespawning months in G1 sole that were housed (a) outdoor under the natural photoperiod and temperature, or (b) indoor under artificial photothermal induction. Maturation was assessed in male and female G1 broodstock in November as controls, after which the remaining population was divided over two outdoor flow-through tanks placed in a pond and two indoor recirculating aquaculture system (RAS) tanks. Subsequently, maturation status (gonadosomatic index GSI and plasma levels of testosterone T and 17β-estradiol E2) was assessed in one tank for each condition in January, February and during spawning in early April, while fish in the other tank were not disturbed in achieving reproductive success. Quantitative real-time PCR was performed to determine species-specific gonadotropin mRNA expression in females. Successful G1 spawning and egg fertilisation occurred in all experimental tanks. Gonadal development was similar under both conditions. Higher E2 and T levels were found in indoor housed females. Gonadotropin expression revealed similar profiles between outdoor and indoor housed females. G1 sole could be reproduced in the outdoor tanks under the natural photoperiod and in the indoor tanks under artificial simulation of this regime that includes a potentially crucial chilling period of 2-3 months at 5-7 °C. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Do assisted-reproduction twin pregnancies require additional antenatal care?

    Science.gov (United States)

    Jauniaux, E; Ben-Ami, I; Maymon, R

    2013-02-01

    Iatrogenic twinning has become the main side-effect assisted reproduction treatment. We have evaluated the evidence for additional care that assisted-reproduction twins may require compared with spontaneous twins. Misacarriages are increased in women with tubal problems and after specific treatments. Assisted-reproduction twin pregnancies complicated by a vanishing twin after 8 weeks have an increased risk of preterm delivery and of low and very low birthweight compared with singleton assisted-reproduction pregnancies. Monozygotic twin pregnancies occur at a higher rate after assisted reproduction treatment and are associated with a higher risk of perinatal complications. The incidence of placenta praevia and vasa praevia is increased in assisted-reproduction twin pregnancies. Large cohort studies do not indicate a higher rate of fetal congenital malformations in assisted-reproduction twins. Overall, assisted-reproduction twins in healthy women assisted-reproduction twins is only increased in women with a pre-existing medical condition such as hypertensive disorders and diabetes and most of these risks can be avoided with single-embryo transfer. Following the birth of the first IVF baby, rumours started to spread in both the medical literature and the media about the long-term health effects for children born following assisted reproduction treatment. However, after more than 30 years, the most common complications associated with IVF treatment remain indirect and technical such as the failure of treatment and ovarian hyperstimulation. Iatrogenic twinning has become the main side-effect of assisted reproduction treatment and the increasing number of twin pregnancies, in particular in older women, has generated numerous debates on the need for additional healthcare provision. In this review, we have evaluated the evidence for additional care that assisted-conception twin pregnancies may require compared with spontaneous twin pregnancies. Twin pregnancies are

  7. Contrasted patterns of age-specific reproduction in long-lived seabirds

    OpenAIRE

    Berman, M.; Gaillard, J.-M.; Weimerskirch, H.

    2008-01-01

    While the number of studies providing evidence of actuarial senescence is increasing, and covers a wide range of taxa, the process of reproductive senescence remains poorly understood. In fact, quite high reproductive output until the last years of life has been reported in several vertebrate species, so that whether or not reproductive senescence is widespread remains unknown. We compared age-specific changes of reproductive parameters between two closely related species of long-lived seabir...

  8. Gene-environment interaction and male reproductive function

    DEFF Research Database (Denmark)

    Axelsson, Jonatan; Bonde, Jens Peter; Giwercman, Yvonne L

    2010-01-01

    As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between...... that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism...... of reproduction, namely environmental and lifestyle factors as the cause of sperm DNA damage. It remains to be investigated to what extent such genetic changes, by natural conception or through the use of assisted reproductive techniques, are transmitted to the next generation, thereby causing increased morbidity...

  9. 21 CFR 884.6170 - Assisted reproduction water and water purification systems.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction water and water purification... Devices § 884.6170 Assisted reproduction water and water purification systems. (a) Identification. Assisted reproduction water purification systems are devices specifically intended to generate high quality...

  10. Reproductive toxicity in boron exposed workers in Bandirma, Turkey.

    Science.gov (United States)

    Başaran, Nurşen; Duydu, Yalçin; Bolt, Hermann M

    2012-06-01

    Boric acid and sodium borates have been considered as being "toxic to reproduction and development", following results of animal studies with high doses. However unfavorable effects of boron exposure on reproduction and development have not been proved in epidemiological studies so far. The aim of the present study was to investigate the reproductive toxicity indicators in highly exposed workers employed in a boric acid production plant in Bandırma, Turkey. Two hundred and four workers participated in this study. The mean blood boron concentration of the high exposure group of workers was 223.89 ± 69.49 (152.82-454.02)ng/g. Unfavorable effects of boron exposure on the reproductive toxicity indicators were not observed. Copyright © 2012 Elsevier GmbH. All rights reserved.

  11. Phenotype and genetic parameters for body measurements, reproductive traits and gut lenght of Nile tilapia (Oreochromis niloticus) selected for growth in low-input earthen ponds

    NARCIS (Netherlands)

    Charo-Karisa, H.; Bovenhuis, H.; Rezk, M.A.; Ponzoni, R.W.; Arendonk, van J.A.M.; Komen, J.

    2007-01-01

    In this study we present estimates of phenotypic and genetic parameters for body size measurements, reproductive traits, and gut length for Nile tilapia (Oreochromis niloticus) selected for growth in fertilized earthen ponds for two generations. Throughout the experiment, ponds were fertilized daily

  12. The effect of maternal and paternal immune challenge on offspring immunity and reproduction in a cricket.

    Science.gov (United States)

    McNamara, K B; van Lieshout, E; Simmons, L W

    2014-06-01

    Trans-generational immune priming is the transmission of enhanced immunity to offspring following a parental immune challenge. Although within-generation increased investment into immunity demonstrates clear costs on reproductive investment in a number of taxa, the potential for immune priming to impact on offspring reproductive investment has not been thoroughly investigated. We explored the reproductive costs of immune priming in a field cricket, Teleogryllus oceanicus. To assess the relative importance of maternal and paternal immune status, mothers and fathers were immune-challenged with live bacteria or a control solution and assigned to one of four treatments in which one parent, neither or both parents were immune-challenged. Families of offspring were reared to adulthood under a food-restricted diet, and approximately 10 offspring in each family were assayed for two measures of immunocompetence. We additionally quantified offspring reproductive investment using sperm viability for males and ovary mass for females. We demonstrate that parental immune challenge has significant consequences for the immunocompetence and, in turn, reproductive investment of their male offspring. A complex interaction between maternal and paternal immune status increased the antibacterial immune response of male offspring. This increased immune response was associated with a reduction in son's sperm viability, implicating a trans-generational resource trade-off between investment into immunocompetence and reproduction. Our data also show that these costs are sexually dimorphic, as daughters did not demonstrate a similar increase in immunity, despite showing a reduction in ovary mass. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  13. Study of nutritional and reproductive constraints of Friesian dairy cattle in the Mitidja area of Algeria

    International Nuclear Information System (INIS)

    Benyoucef, M.T.; Nekkal, T.; Khelili, A.; Khelili, R.; Nefafa, S.

    1999-01-01

    This work aims to improve reproduction and milk production of Friesian dairy cows used under the environmental conditions of the Mitidja Plain (Central region of Algeria) by analyzing the quality of feeding and studying the resumption of ovarian activity of cows after calving. The first phase of the study started during 1995/96, by surveying a sample of 47 livestock farms in the Mitidja area in order to identify available feed resources and husbandry practices and to record data on reproduction parameters, individual body weights, body condition score and milk production. Ovarian activity was monitored by radioimmunoassay of progesterone in blood and milk samples collected twice a week, after 15 days post-partum. The second phase was conducted in 1996 and 1997 in two dairy farms. Data were collected on the same parameters of reproduction and production. During the second year, the results of dairy herds were better than those in the first year. That was probably due to monitoring provided by the research project. (author)

  14. Reproductive protein evolution in two cryptic species of marine chordate

    Science.gov (United States)

    2011-01-01

    Background Reproductive character displacement (RCD) is a common and taxonomically widespread pattern. In marine broadcast spawning organisms, behavioral and mechanical isolation are absent and prezygotic barriers between species often operate only during the fertilization process. Such barriers are usually a consequence of differences in the way in which sperm and egg proteins interact, so RCD can be manifest as faster evolution of these proteins between species in sympatry than allopatry. Rapid evolution of these proteins often appears to be a consequence of positive (directional) selection. Here, we identify a set of candidate gamete recognition proteins (GRPs) in the ascidian Ciona intestinalis and showed that these GRPs evolve more rapidly than control proteins (those not involved in gamete recognition). Choosing a subset of these gamete recognition proteins that show evidence of positive selection (CIPRO37.40.1, CIPRO60.5.1, CIPRO100.7.1), we then directly test the RCD hypothesis by comparing divergence (omega) and polymorphism (McDonald-Kreitman, Tajima's D, Fu and Li's D and F, Fay and Wu's H) statistics in sympatric and allopatric populations of two distinct forms of C. intestinalis (Types A and B) between which there are strong post-zygotic barriers. Results Candidate gamete recognition proteins from two lineages of C. intestinalis (Type A and B) are evolving more rapidly than control proteins, consistent with patterns seen in insects and mammals. However, ω (dN/dS) is not significantly different between the sympatric and allopatric populations, and none of the polymorphism statistics show significant differences between sympatric and allopatric populations. Conclusions Enhanced prezygotic isolation in sympatry has become a well-known feature of gamete recognition proteins in marine broadcast spawners. But in most cases the evolutionary process or processes responsible for this pattern have not been identified. Although gamete recognition proteins in C

  15. Reproductive protein evolution in two cryptic species of marine chordate

    Directory of Open Access Journals (Sweden)

    Harrison Richard G

    2011-01-01

    Full Text Available Abstract Background Reproductive character displacement (RCD is a common and taxonomically widespread pattern. In marine broadcast spawning organisms, behavioral and mechanical isolation are absent and prezygotic barriers between species often operate only during the fertilization process. Such barriers are usually a consequence of differences in the way in which sperm and egg proteins interact, so RCD can be manifest as faster evolution of these proteins between species in sympatry than allopatry. Rapid evolution of these proteins often appears to be a consequence of positive (directional selection. Here, we identify a set of candidate gamete recognition proteins (GRPs in the ascidian Ciona intestinalis and showed that these GRPs evolve more rapidly than control proteins (those not involved in gamete recognition. Choosing a subset of these gamete recognition proteins that show evidence of positive selection (CIPRO37.40.1, CIPRO60.5.1, CIPRO100.7.1, we then directly test the RCD hypothesis by comparing divergence (omega and polymorphism (McDonald-Kreitman, Tajima's D, Fu and Li's D and F, Fay and Wu's H statistics in sympatric and allopatric populations of two distinct forms of C. intestinalis (Types A and B between which there are strong post-zygotic barriers. Results Candidate gamete recognition proteins from two lineages of C. intestinalis (Type A and B are evolving more rapidly than control proteins, consistent with patterns seen in insects and mammals. However, ω (dN/dS is not significantly different between the sympatric and allopatric populations, and none of the polymorphism statistics show significant differences between sympatric and allopatric populations. Conclusions Enhanced prezygotic isolation in sympatry has become a well-known feature of gamete recognition proteins in marine broadcast spawners. But in most cases the evolutionary process or processes responsible for this pattern have not been identified. Although gamete

  16. Reproductive strategies of two sympatric "small barbs" (Barbus humilis and B. tanapelagius, Cyprinidae) in Lake Tana

    NARCIS (Netherlands)

    Dejen, E.; Sibbing, F.A.; Vijverberg, J.

    2003-01-01

    The reproductive strategies of two species of 'small barbs' (12,000 fish). Both species have a long breeding period (from March to September), and the distinct bimodal size-frequency distributions of eggs suggest multiple spawning for both species. Absolute fecundity increased exponentially with

  17. Reproductive health and empowerment -- a Rajasthan perspective.

    Science.gov (United States)

    Pal, P; Joshi, V

    1996-01-01

    Reproductive health is one of the major issues of current feminist debates. The issue was brought to light because of population control policies which are being enforced through women's bodies and the spread of HIV/AIDS. In this context, women's organizations and activists are trying to focus upon the issue of reproductive health as part of the larger issue of the position of women in families, societies, and states. Policy makers and donor agencies are trying to address the problem as lack of awareness and knowledge of how to use contraceptives. The authors argue in this situation that it is important to study reproductive health relative to the status of women in society. This paper looks at the existing social construct of patriarchy and population control policies in relation to reproductive health. Women and self, the reproductive role of women, preference for male children, family planning decision making, family planning programs and reproductive health, and the Vikalp program in two districts of Rajasthan are discussed.

  18. Avian reproductive physiology

    Science.gov (United States)

    Gee, G.F.; Gibbons, Edward F.; Durrant, Barbara S.; Demarest, Jack

    1995-01-01

    Knowledge of the many physiological factors associated with egg production , fertility, incubation, and brooding in nondomestic birds is limited. Science knows even less about reproduction in most of the 238 endangered or threatened birds. This discussion uses studies of nondomestic and, when necessary, domestic birds to describe physiological control of reproduction. Studies of the few nondomestic avian species show large variation in physiological control of reproduction. Aviculturists, in order to successfully propagate an endangered bird, must understand the bird's reproductive peculiarities. First, investigators can do studies with carefully chosen surrogate species, but eventually they need to confirm the results in the target endangered bird. Studies of reproduction in nondomestic birds increased in the last decade. Still, scientists need to do more comparative studies to understand the mechanisms that control reproduction in birds. New technologies are making it possible to study reproductive physiology of nondomestic species in less limiting ways. These technologies include telemetry to collect information without inducing stress on captives (Howey et al., 1987; Klugman, 1987), new tests for most of the humoral factors associated with reproduction, and the skill to collect small samples and manipulate birds without disrupting the physiological mechanisms (Bercovitz et al., 1985). Managers are using knowledge from these studies to improve propagation in zoological parks, private and public propagation facilities, and research institutions. Researchers need to study the control of ovulation, egg formation, and oviposition in the species of nondomestic birds that lay very few eggs in a season, hold eggs in the oviduct for longer intervals, or differ in other ways from the more thoroughly studied domestic birds. Other techniques that would enhance propagation for nondomestlc birds include tissue culture of cloned embryonic cells, cryopreservation of embryos

  19. Factors affecting reproductive performance of dairy cows.

    Science.gov (United States)

    Coleman, D A; Thayne, W V; Dailey, R A

    1985-07-01

    We conducted two studies to determine how herd management practices and traits of individual cows affect performance of the herd and of the cow within a herd. Management practices, reproductive performance of the herd, and relationships between management and reproductive performance were characterized on 83 dairy farms with 7596 cows. Data included 21 management variables (e.g., facilities, herd health program, estrous detection program) and 8 performance variables obtained from Dairy Herd Improvement or unofficial records (e.g., size of herd, production, days open). Although varying among herds, annual average herd incidences of reproductive disorders and reproductive performance were similar to those reported. Managerial practices influenced incidences of retained placenta and uterine infection, days open of cows not bred and of all cows, services per conception, and percentages of herd open more than 100 days and culled for low production. Veterinarian was the most consistent variable influencing herd reproductive performance. Data also were collected from production and lifetime records of 2532 cows in 19 herds. Reproductive performance was affected by season of calving, production, maturity, and reproductive disorders. Several cows with extremely poor reproductive records were maintained.

  20. An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans.

    Science.gov (United States)

    Sparkman, Amanda M; Arnold, Stevan J; Bronikowski, Anne M

    2007-04-07

    Evolutionary theory predicts that differential reproductive effort and rate of reproductive senescence will evolve under different rates of external mortality. We examine the evolutionary divergence of age-specific reproduction in two life-history ecotypes of the western terrestrial garter snake, Thamnophis elegans. We test for the signature of reproductive senescence (decreasing fecundity with age) and increasing reproductive effort with age (increasing reproductive productivity per gram female) in replicate populations of two life-history ecotypes: snakes that grow fast, mature young and have shorter lifespans, and snakes that grow slow, mature late and have long lives. The difference between life-history ecotypes is due to genetic divergence in growth rate. We find (i) reproductive success (live litter mass) increases with age in both ecotypes, but does so more rapidly in the fast-growth ecotype, (ii) reproductive failure increases with age in both ecotypes, but the proportion of reproductive failure to total reproductive output remains invariant, and (iii) reproductive effort remains constant in fast-growth individuals with age, but declines in slow-growth individuals. This illustration of increasing fecundity with age, even at the latest ages, deviates from standard expectations for reproductive senescence, as does the lack of increases in reproductive effort. We discuss our findings in light of recent theories regarding the phenomenon of increased reproduction throughout life in organisms with indeterminate growth and its potential to offset theoretical expectations for the ubiquity of senescence.

  1. Do sex, body size and reproductive condition influence the thermal preferences of a large lizard? A study in Tupinambis merianae.

    Science.gov (United States)

    Cecchetto, Nicolas Rodolfo; Naretto, Sergio

    2015-10-01

    Body temperature is a key factor in physiological processes, influencing lizard performances; and life history traits are expected to generate variability of thermal preferences in different individuals. Gender, body size and reproductive condition may impose specific requirements on preferred body temperatures. If these three factors have different physiological functions and thermal requirements, then the preferred temperature may represent a compromise that optimizes these physiological functions. Therefore, the body temperatures that lizards select in a controlled environment may reflect a temperature that maximizes their physiological needs. The tegu lizard Tupinambis merianae is one of the largest lizards in South America and has wide ontogenetic variation in body size and sexual dimorphism. In the present study we evaluate intraspecific variability of thermal preferences of T. merianae. We determined the selected body temperature and the rate at which males and females attain their selected temperature, in relation to body size and reproductive condition. We also compared the behavior in the thermal gradient between males and females and between reproductive condition of individuals. Our study show that T. merianae selected body temperature within a narrow range of temperatures variation in the laboratory thermal gradient, with 36.24±1.49°C being the preferred temperature. We observed no significant differences between sex, body size and reproductive condition in thermal preferences. Accordingly, we suggest that the evaluated categories of T. merianae have similar thermal requirements. Males showed higher rates to obtain heat than females and reproductive females, higher rates than non-reproductive ones females. Moreover, males and reproductive females showed a more dynamic behavior in the thermal gradient. Therefore, even though they achieve the same selected temperature, they do it differentially. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Comparing the Sexual Reproductive Success of Two Exotic Trees Invading Spanish Riparian Forests vs. a Native Reference.

    Science.gov (United States)

    Cabra-Rivas, Isabel; Castro-Díez, Pilar

    2016-01-01

    A widely accepted hypothesis in invasion ecology is that invasive species have higher survival through the early stages of establishment than do non-invasive species. In this study we explore the hypothesis that the sexual reproductive success of the invasive trees Ailanthus altissima (Mill.) Swingle and Robinia pseudoacacia L. is higher than that of the native Fraxinus angustifolia Vahl., all three species coexisting within the riparian forests of Central Spain. We compared different stages of the early life cycle, namely seed rain, seed infestation by insects, seed removal by local fauna, seed germination under optimal conditions and seedling abundance between the two invasive trees and the native, in order to assess their sexual reproductive success. The exotic species did not differ from the native reference (all three species displaying high seed rain and undergoing seed losses up to 50% due to seed removal by the local fauna). Even if the exotic R. pseudoacacia showed a high percentage of empty and insect-parasited seeds along with a low seedling emergence and the exotic A. altissima was the species with more viable seeds and of higher germinability, no differences were found regarding these variables when comparing them with the native F. angustifolia. Unsuitable conditions might have hampered either seedling emergence and survival, as seedling abundance in the field was lower than expected in all species -especially in R. pseudoacacia-. Our results rather suggest that the sexual reproductive success was not higher in the exotic trees than in the native reference, but studies focusing on long-term recruitment would help to shed light on this issue.

  3. Tunneling ionization and harmonic generation in two-color fields

    International Nuclear Information System (INIS)

    Kondo, K.; Kobayashi, Y.; Sagisaka, A.; Nabekawa, Y.; Watanabe, S.

    1996-01-01

    Tunneling ionization and harmonic generation in two-color fields were studied with a fundamental beam (ω) and its harmonics (2ω,3ω), which were generated by a 100-fs Ti:sapphire laser. Ion yields of atoms and molecules were successfully controlled by means of a change in the relative phase between ω and 3ω pulses. Two-color interference was clearly observed in photoelectron spectra and harmonic spectra. In the ω endash 2ω field even-order harmonics were observed in which the intensity was almost equal to that of the odd harmonics because of an asymmetric optical field. These results were compared with the quasi-static model for ionization and with the quantum theory for harmonic generation. copyright 1996 Optical Society of America

  4. The role of adiponectin in reproduction: from polycystic ovary syndrome to assisted reproduction.

    Science.gov (United States)

    Michalakis, Konstantinos G; Segars, James H

    2010-11-01

    To summarize the effects of the adipokine adiponectin on the reproductive endocrine system, from the hypothalamic-pituitary axis to the gonads and target tissues of the reproductive system. A Medline computer search was performed to identify relevant articles. Research institution. None. Adiponectin is a hormone secreted by adipose tissue that acts to reduce insulin resistance and atherogenic damage, but it also exerts actions in other tissues. Adiponectin mediates its actions in the periphery mainly via two receptors, AdipoR1 and AdipoR2. Adiponectin receptors are present in many reproductive tissues, including the central nervous system, ovaries, oviduct, endometrium, and testes. Adiponectin influences gonadotropin release, normal pregnancy, and assisted reproduction outcomes. Adiponectin, a beneficial adipokine, represents a major link between obesity and reproduction. Higher levels of adiponectin are associated with improved menstrual function and better outcomes in assisted reproductive cycles. Published by Elsevier Inc.

  5. A review of reproductive toxicity of microcystins

    International Nuclear Information System (INIS)

    Chen, Liang; Chen, Jun; Zhang, Xuezhen; Xie, Ping

    2016-01-01

    Highlights: • Reproductive toxicity of MCs on mammals, fishes, amphibians, and birds is reviewed. • PP1/2A inhibition and oxidative stress are important toxic mechanisms of MCs. • Reproductive toxicity of MCs may be closely related to endocrine-disrupting effects. • The trans-generational toxicity of microcystins is a matter of concern. • Data concerning female reproductive and sex-specific effects of MCs are lacking. - Abstract: Animal studies provide strong evidence of positive associations between microcystins (MCs) exposure and reproductive toxicity, representing a threat to human reproductive health and the biodiversity of wild life. This paper reviews current knowledge of the reproductive toxicity of MCs, with regard to mammals, fishes, amphibians, and birds, mostly in males. Toxicity of MCs is primarily governed by the inhibition of protein phosphatases 1 and 2A (PP1 and PP2A) and disturbance of cellular phosphorylation balance. MCs exposure is related to excessive production of reactive oxygen species (ROS) and oxidative stress, leading to cytoskeleton disruption, mitochondria dysfunction, endoplasmic reticulum (ER) stress, and DNA damage. MCs induce cell apoptosis mediated by the mitochondrial and ROS and ER pathways. Through PP1/2A inhibition and oxidative stress, MCs lead to differential expression/activity of transcriptional factors and proteins involved in the pathways of cellular differentiation, proliferation, and tumor promotion. MC-induced DNA damage is also involved in carcinogenicity. Apart from a direct effect on testes and ovaries, MCs indirectly affect sex hormones by damaging the hypothalamic-pituitary-gonad (HPG) axis and liver. Parental exposure to MCs may result in hepatotoxicity and neurotoxicity of offspring. We also summarize the current research gaps which should be addressed by further studies.

  6. A review of reproductive toxicity of microcystins

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Liang, E-mail: chan91@yeah.net [Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Jun, E-mail: chenjun@ihb.ac.cn [Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Zhang, Xuezhen, E-mail: xuezhen@mail.hzau.edu.cn [College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Xie, Ping, E-mail: xieping@ihb.ac.cn [Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)

    2016-01-15

    Highlights: • Reproductive toxicity of MCs on mammals, fishes, amphibians, and birds is reviewed. • PP1/2A inhibition and oxidative stress are important toxic mechanisms of MCs. • Reproductive toxicity of MCs may be closely related to endocrine-disrupting effects. • The trans-generational toxicity of microcystins is a matter of concern. • Data concerning female reproductive and sex-specific effects of MCs are lacking. - Abstract: Animal studies provide strong evidence of positive associations between microcystins (MCs) exposure and reproductive toxicity, representing a threat to human reproductive health and the biodiversity of wild life. This paper reviews current knowledge of the reproductive toxicity of MCs, with regard to mammals, fishes, amphibians, and birds, mostly in males. Toxicity of MCs is primarily governed by the inhibition of protein phosphatases 1 and 2A (PP1 and PP2A) and disturbance of cellular phosphorylation balance. MCs exposure is related to excessive production of reactive oxygen species (ROS) and oxidative stress, leading to cytoskeleton disruption, mitochondria dysfunction, endoplasmic reticulum (ER) stress, and DNA damage. MCs induce cell apoptosis mediated by the mitochondrial and ROS and ER pathways. Through PP1/2A inhibition and oxidative stress, MCs lead to differential expression/activity of transcriptional factors and proteins involved in the pathways of cellular differentiation, proliferation, and tumor promotion. MC-induced DNA damage is also involved in carcinogenicity. Apart from a direct effect on testes and ovaries, MCs indirectly affect sex hormones by damaging the hypothalamic-pituitary-gonad (HPG) axis and liver. Parental exposure to MCs may result in hepatotoxicity and neurotoxicity of offspring. We also summarize the current research gaps which should be addressed by further studies.

  7. Two-Level Semantics and Code Generation

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis

    1988-01-01

    A two-level denotational metalanguage that is suitable for defining the semantics of Pascal-like languages is presented. The two levels allow for an explicit distinction between computations taking place at compile-time and computations taking place at run-time. While this distinction is perhaps...... not absolutely necessary for describing the input-output semantics of programming languages, it is necessary when issues such as data flow analysis and code generation are considered. For an example stack-machine, the authors show how to generate code for the run-time computations and still perform the compile...

  8. Life tables and reproductive parameters of Lutzomyia spinicrassa (Diptera: Psychodidae) under laboratory conditions.

    Science.gov (United States)

    Escovar, Jesús; Bello, Felio J; Morales, Alberto; Moncada, Ligia; Cárdenas, Estrella

    2004-10-01

    Lutzomyia spinicrassa is a vector of Leishmania braziliensis in Colombia. This sand fly has a broad geographical distribution in Colombia and Venezuela and it is found mainly in coffee plantations. Baseline biological growth data of L. spinicrassa were obtained under experimental laboratory conditions. The development time from egg to adult ranged from 59 to 121 days, with 12.74 weeks in average. Based on cohorts of 100 females, horizontal life table was constructed. The following predictive parameters were obtained: net rate of reproduction (8.4 females per cohort female), generation time (12.74 weeks), intrinsic rate of population increase (0.17), and finite rate of population increment (1.18). The reproductive value for each class age of the cohort females was calculated. Vertical life tables were elaborated and mortality was described for the generation obtained of the field cohort. In addition, for two successive generations, additive variance and heritability for fecundity were estimated.

  9. Life tables and reproductive parameters of Lutzomyia spinicrassa (Diptera: Psychodidae under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Jesús Escovar

    2004-10-01

    Full Text Available Lutzomyia spinicrassa is a vector of Leishmania braziliensis in Colombia. This sand fly has a broad geographical distribution in Colombia and Venezuela and it is found mainly in coffee plantations. Baseline biological growth data of L. spinicrassa were obtained under experimental laboratory conditions. The development time from egg to adult ranged from 59 to 121 days, with 12.74 weeks in average. Based on cohorts of 100 females, horizontal life table was constructed. The following predictive parameters were obtained: net rate of reproduction (8.4 females per cohort female, generation time (12.74 weeks, intrinsic rate of population increase (0.17, and finite rate of population increment (1.18. The reproductive value for each class age of the cohort females was calculated. Vertical life tables were elaborated and mortality was described for the generation obtained of the field cohort. In addition, for two successive generations, additive variance and heritability for fecundity were estimated.

  10. Evaluation of a reproductive index to estimate grasshopper sparrow and eastern meadowlark reproductive success

    Science.gov (United States)

    Althoff, Donald P.; Gipson, P.S.; Pontius, J.S.; Japuntich, R.D.

    2009-01-01

    We compared an index of reproductive success based on breeding behavior to actual nest fates of grasshopper sparrows (Ammodramus savannarum) and eastern meadowlarks (Sturnella magna) on 12 plots (4-ha). Concordance of results between the two methods was 58% for grasshopper sparrows and 42% for eastern meadowlarks on a plot-by-plot basis. The indirect method yielded higher estimates of reproductive activity than nest monitoring for the balance of the plots,. There was little evidence that brown-headed cowbird (Molothrus ater) parasitism influenced the estimates of reproductive success using the indirect method. We concluded that nests and about-to-fledge nestlings were missed during searches on some plots. It may be appropriate to use an indirect method to more efficiently survey territories and/or plots for species with hard-to-find nests or when monitoring large areas. Use of a reproductive index may be appropriate and more time-efficient than nest searching and monitoring for comparing management effects such as burning, grazing, haying, military training, and other localized disturbances that are likely to affect reproductive success of grasshopper sparrows and eastern meadowlarks. However, nest monitoring may be necessary for more precise estimates of productivity necessary for long-term monitoring. Nest monitoring results are also likely to allow for direct comparisons to results from other studies because the index method requires intimate knowledge of the species being evaluated - a factor that could lead to reduced precision because the experience level of technicians relying only on behavioral cues from study-to-study is likely to vary considerably.

  11. Testing independence between two Poisson-generated multinomial variables in case-series and cohort studies.

    Science.gov (United States)

    Hocine, Mounia; Guillemot, Didier; Tubert-Bitter, Pascale; Moreau, Thierry

    2005-12-30

    In case-series or cohort studies, we propose a test of independence between the occurrences of two types of recurrent events (such as two repeated infections) related to an intermittent exposure (such as an antibiotic treatment). The test relies upon an extension of a recent method for analysing case-series data, in the presence of one type of recurrent event. The test statistic is derived from a bivariate Poisson generated-multinomial distribution. Simulations for checking the validity of the test concerning the type I error and the power properties are presented. The test is illustrated using data from a cohort on antibiotics bacterial resistance in schoolchildren. Copyright 2005 John Wiley & Sons, Ltd.

  12. Evaluating the Effects of the Kingston Fly Ash Release on Fish Reproduction: Spring 2009 - 2010 Studies

    Energy Technology Data Exchange (ETDEWEB)

    Greeley Jr, Mark Stephen [ORNL; Adams, Marshall [ORNL; McCracken, Kitty [ORNL

    2012-05-01

    with the ability of individuals within a population to reproduce. Reproduction is thus generally considered to be the most critical life function affected by environmental contamination. From a regulatory perspective, the issue of potential contaminant-related effects on fish reproduction from the Kingston fly ash spill has particular significance because the growth and propagation of fish and other aquatic life is a specific classified use of the affected river systems. To address the potential effects of fly ash from the Kingston spill on the reproductive health of exposed fish populations, ORNL has undertaken a series of studies in collaboration with TVA that include: (1) a combined field study of metal bioaccumulation in ovaries and other fish tissues (Adams and others 2012) and the reproductive condition of sentinel fish species in reaches of the Emory and Clinch Rivers affected by the fly ash spill (the current report); (2) laboratory tests of the potential toxicity of fly ash from the spill area on fish embryonic and larval development (Greeley and others 2012); (3) additional laboratory experimentation focused on the potential effects of long-term exposures to fly ash on fish survival and reproductive competence (unpublished); and (4) a combined field and laboratory study examining the in vitro developmental success of embryos and larvae obtained from fish exposed in vivo for over two years to fly ash in the Emory and Clinch Rivers (unpublished). The current report focuses on the reproductive condition of adult female fish in reaches of the Emory and Clinch Rivers influenced by the fly ash spill at the beginning of the spring 2009 breeding season - the first breeding season immediately following the fly ash release - and during the subsequent spring 2010 breeding season. Data generated from this and related reproductive/early life stage studies provide direct input to ecological risk assessment efforts and complement and support other phases of the overall

  13. Study of two medium size 'C' core electromagnets generating low magnetic fields

    International Nuclear Information System (INIS)

    Bhatia, M.S.; Dass, S.; Chatterjee, U.K.

    1987-01-01

    Magnetic field requirements of laboratories may impose constraints that often call for a variety of non-standard designs. The designer has to fulfil these demands without letting the design to become too inefficient. Since no ready design procedures are available he has to resort to intuition calculation and modelling. In spite of this there may be wide discrepancy between the design values and the actual results. This report describes the experience gained on two 'C' core electromagnets being used by authors. These magnets generate low magnetic fields over reasonably large volumes, a requirement that runs opposite to that of most other magnets. The study reveals the dependence of overall performance efficiency, field uniformity etc. on the design parameters. 31 figures. (author)

  14. Reproductive Investment and Health Costs in Roma Women

    Directory of Open Access Journals (Sweden)

    Jelena Čvorović

    2017-11-01

    Full Text Available In this paper, we examine whether variation in reproductive investment affects the health of Roma women using a dataset collected through original anthropological fieldwork among Roma women in Serbia. Data were collected in 2014–2016 in several Roma semi-urban settlements in central Serbia. The sample consisted of 468 Roma women, averaging 44 years of age. We collected demographic data (age, school levels, socioeconomic status, risk behaviors (smoking and alcohol consumption, marital status, and reproductive history variables (the timing of reproduction, the intensity of reproduction, reproductive effort and investment after birth, in addition to self-reported health, height, and weight. Data analyses showed that somatic, short-term costs of reproduction were revealed in this population, while evolutionary, long-term costs were unobservable—contrariwise, Roma women in poor health contributed more to the gene pool of the next generation than their healthy counterparts. Our findings appear to be consistent with simple trade-off models that suggest inverse relationships between reproductive effort and health. Thus, personal sacrifice—poor health as an outcome—seems crucial for greater reproductive success.

  15. Studies on the reproductive efficiency of cattle using radioimmunoassay techniques

    International Nuclear Information System (INIS)

    1990-01-01

    In 1982 the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, initiated a co-ordinated research programme with the aim of stimulating studies to characterize and improve the reproductive performance of indigenous cattle under the diverse environmental and management conditions prevailing in developing countries. This publication represents the results of the five year co-ordinated research programme, individual papers being essentially a synthesis of the work presented by the participants of the programme at the final research co-ordination meeting held in Vienna from 5 to 9 September 1988. Concurrently with the above mentioned research co-ordination meeting, the Joint FAO/IAEA Division held a consultants meeting on the interaction between reproduction, disease, nutrition and the environment, and on field reproductive management strategies. The papers presented by the consultants as well as their recommendations are included in this publication. These recommendations will form the basis of the future direction of livestock reproduction research programmes supported by the Joint FAO/IAEA Division. Refs, figs and tabs

  16. Assisted reproductive technology in Europe, 2006: results generated from European registers by ESHRE

    DEFF Research Database (Denmark)

    de Mouzon, J; Goossens, V; Bhattacharya, S

    2010-01-01

    In this 10th European IVF-monitoring (EIM) report, the results of assisted reproductive techniques from treatments initiated in Europe during 2006 are presented. Data were mainly collected from existing national registers.......In this 10th European IVF-monitoring (EIM) report, the results of assisted reproductive techniques from treatments initiated in Europe during 2006 are presented. Data were mainly collected from existing national registers....

  17. Fishery status, growth, reproduction biology and feeding habit of two scombrid fish from the Gulf of Aqaba, Red Sea

    International Nuclear Information System (INIS)

    Al-Zibdah, M.; Odat, N.

    2007-01-01

    The fishery and some biological aspects of two Scombrid fish species, Katsuwonus pelamis and Euthynnus affinis from the Gulf of Aqaba were studied during one year period (1999-2000). Monthly samples of the two species were collected to investigate growth, reproduction and feeding habit. Results showed that the Scombridae family form more than 60% of the total catch of Jordanian fishery. The length-weight relationships (LWr) in the two fish species demonstrated thatthe growth is of an allometric type (around 3). The condition factor (k) showed relatively consistent values in both species but revealed slight variability in growth periods. This could be attributed to the limited food availability in fish natural habitat. Different age classes were observed in the catch of the two species irrespective of season. The mean GSI exhibited similar change pattern with season in both sexes of the two fish. Spawning behavior and planktonic larvae of both fish were not observed in the field. This could be inferred that these fish are not migrating to the region for reproduction. The food composition of K. pelamis and E. affinis suggests that the fish compete for the same food items. These are the fish At herinomorous lacunosus, crustacean and molluscans. Prey occurrence in fish stomachs is attributed mainly to the seasonal availability of food in the Gulf of Aqaba. High abundance of food items in winter may indicate that the two species migrate at the climax of primary productivity in the Gulf. (author)

  18. Growth, Survival and Reproduction of the Giant Clam Tridacna maxima (Röding 1798, Bivalvia) in Two Contrasting Lagoons in French Polynesia

    Science.gov (United States)

    Van Wynsberge, Simon; Andréfouët, Serge; Gaertner-Mazouni, Nabila; Wabnitz, Colette C. C.; Menoud, Mathilde; Le Moullac, Gilles; Levy, Peva; Gilbert, Antoine; Remoissenet, Georges

    2017-01-01

    Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago) and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago) in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tatakoto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity indices in June and July 2014, were timed with high oceanic water inflow and a decrease in lagoon water temperature. Secondly, temperature explained differences in shell growth rates between seasons and lagoons, generating different growth curves for the two sites. Thirdly, local mortality rates were also found to likely be related to water renewal patterns. In conclusion, our study suggests that reef aperture and lagoon water renewal rates play an integral role in giant clam life history, with significant differences in rates of shell growth, mortality and fertility found between open versus semi-closed atoll lagoons in coral reef ecosystems. PMID:28118406

  19. Growth, Survival and Reproduction of the Giant Clam Tridacna maxima (Röding 1798, Bivalvia in Two Contrasting Lagoons in French Polynesia.

    Directory of Open Access Journals (Sweden)

    Simon Van Wynsberge

    Full Text Available Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tatakoto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity indices in June and July 2014, were timed with high oceanic water inflow and a decrease in lagoon water temperature. Secondly, temperature explained differences in shell growth rates between seasons and lagoons, generating different growth curves for the two sites. Thirdly, local mortality rates were also found to likely be related to water renewal patterns. In conclusion, our study suggests that reef aperture and lagoon water renewal rates play an integral role in giant clam life history, with significant differences in rates of shell growth, mortality and fertility found between open versus semi-closed atoll lagoons in coral reef ecosystems.

  20. Growth, chamber building rate and reproduction time of Palaeonummulites venosus (Foraminifera) under natural conditions

    Science.gov (United States)

    Kinoshita, Shunichi; Eder, Wolfgang; Wöger, Julia; Hohenegger, Johann; Briguglio, Antonino

    2017-12-01

    We investigated the symbiont-bearing benthic foraminifer Palaeonummulites venosus to determine the chamber building rate (CBR), test diameter increase rate (DIR), reproduction time and longevity using the `natural laboratory' approach. This is based on the decomposition of monthly obtained frequency distributions of chamber number and test diameter into normally distributed components. Test measurements were taken using MicroCT. The shift of the mean and standard deviation of component parameters during the 15-month investigation period was used to calculate Michaelis-Menten functions applied to estimate the averaged CBR and DIR under natural conditions. The individual dates of birth were estimated using the inverse averaged CBR and the inverse DIR fitted by the individual chamber number or the individual test diameter at the sampling date. Distributions of frequencies and densities (i.e., frequency divided by sediment weight) based on both CBR and DIR revealed continuous reproduction throughout the year with two peaks, a stronger one in June determined as the onset of the summer generation (generation 1) and a weaker one in November determined as the onset of the winter generation (generation 2). This reproduction scheme explains the presence of small and large specimens in the same sample. Longevity, calculated as the maximum difference in days between the individual's birth date and the sampling date, is approximately 1.5 yr, an estimation obtained by using both CBR and DIR.

  1. Output power control of two coupled wind generators

    Directory of Open Access Journals (Sweden)

    A Boukhelifa

    2016-09-01

    Full Text Available In this paper we are interested to the power control of two wind generators coupled to the network through power converters. Every energy chain conversion is composed of a wind turbine, a gearbox, a Double Fed Induction Generator (DFIG, two PWM converters and a DC bus. The power exchange and the DC voltage are controlled by the use of proportional integral correctors. For our study, initially we have modeled all the components of the one system energy conversion, and then we have simulated its behavior using Matlab/Simulink. In another part of this paper we present the analysis of the interaction and the powerflow between the two aerogenerators following a disturbance due to wind speed on every turbine. Also we have considered a connection fault to the DC bus. In each case the assessment of power brought into play is checked. Simulation tests are established.

  2. Acoustic Performance of a Real-Time Three-Dimensional Sound-Reproduction System

    Science.gov (United States)

    Faller, Kenneth J., II; Rizzi, Stephen A.; Aumann, Aric R.

    2013-01-01

    The Exterior Effects Room (EER) is a 39-seat auditorium at the NASA Langley Research Center and was built to support psychoacoustic studies of aircraft community noise. The EER has a real-time simulation environment which includes a three-dimensional sound-reproduction system. This system requires real-time application of equalization filters to compensate for spectral coloration of the sound reproduction due to installation and room effects. This paper describes the efforts taken to develop the equalization filters for use in the real-time sound-reproduction system and the subsequent analysis of the system s acoustic performance. The acoustic performance of the compensated and uncompensated sound-reproduction system is assessed for its crossover performance, its performance under stationary and dynamic conditions, the maximum spatialized sound pressure level it can produce from a single virtual source, and for the spatial uniformity of a generated sound field. Additionally, application examples are given to illustrate the compensated sound-reproduction system performance using recorded aircraft flyovers

  3. Two-phase flow induced vibrations in CANDU steam generators

    International Nuclear Information System (INIS)

    Gidi, A.

    2009-01-01

    . Increased values of turbulence will lower the void fraction required for instability. The second explanation is the flow regime. In this study, it was clear that flow regime for bundle void generation was at all times bubbly and homogeneous, while the upstream void fraction generation cases showed a churn type of flow. A change in flow regime from bubbly to churn flow will produce the same effect as an increase in turbulent buffeting levels, and hence it seems difficult with the present knowledge to distinguish between the two causes. In as much as turbulent levels are related to flow regime, it is essential to have a clear knowledge of the flow regime in steam generators in order to predict the tubes fluid-elastic instability threshold. (author)

  4. Reproductive Conflict and the Evolution of Menopause in Killer Whales.

    Science.gov (United States)

    Croft, Darren P; Johnstone, Rufus A; Ellis, Samuel; Nattrass, Stuart; Franks, Daniel W; Brent, Lauren J N; Mazzi, Sonia; Balcomb, Kenneth C; Ford, John K B; Cant, Michael A

    2017-01-23

    Why females of some species cease ovulation prior to the end of their natural lifespan is a long-standing evolutionary puzzle [1-4]. The fitness benefits of post-reproductive helping could in principle select for menopause [1, 2, 5], but the magnitude of these benefits appears insufficient to explain the timing of menopause [6-8]. Recent theory suggests that the cost of inter-generational reproductive conflict between younger and older females of the same social unit is a critical missing term in classical inclusive fitness calculations (the "reproductive conflict hypothesis" [6, 9]). Using a unique long-term dataset on wild resident killer whales, where females can live decades after their final parturition, we provide the first test of this hypothesis in a non-human animal. First, we confirm previous theoretical predictions that local relatedness increases with female age up to the end of reproduction. Second, we construct a new evolutionary model and show that given these kinship dynamics, selection will favor younger females that invest more in competition, and thus have greater reproductive success, than older females (their mothers) when breeding at the same time. Third, we test this prediction using 43 years of individual-based demographic data in resident killer whales and show that when mothers and daughters co-breed, the mortality hazard of calves from older-generation females is 1.7 times that of calves from younger-generation females. Intergenerational conflict combined with the known benefits conveyed to kin by post-reproductive females can explain why killer whales have evolved the longest post-reproductive lifespan of all non-human animals. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Factors that Influence Male Involvement in Sexual and Reproductive ...

    African Journals Online (AJOL)

    Erah

    discuss matters of sexuality with his female children. This cultural belief not only protects men from discussing issues of reproductive health; it contributes to the general lack of male involvement in reproductive health. Although the majority of participants mentioned that most married men. (especially the older generation) ...

  6. Comparing the Sexual Reproductive Success of Two Exotic Trees Invading Spanish Riparian Forests vs. a Native Reference.

    Directory of Open Access Journals (Sweden)

    Isabel Cabra-Rivas

    Full Text Available A widely accepted hypothesis in invasion ecology is that invasive species have higher survival through the early stages of establishment than do non-invasive species. In this study we explore the hypothesis that the sexual reproductive success of the invasive trees Ailanthus altissima (Mill. Swingle and Robinia pseudoacacia L. is higher than that of the native Fraxinus angustifolia Vahl., all three species coexisting within the riparian forests of Central Spain. We compared different stages of the early life cycle, namely seed rain, seed infestation by insects, seed removal by local fauna, seed germination under optimal conditions and seedling abundance between the two invasive trees and the native, in order to assess their sexual reproductive success. The exotic species did not differ from the native reference (all three species displaying high seed rain and undergoing seed losses up to 50% due to seed removal by the local fauna. Even if the exotic R. pseudoacacia showed a high percentage of empty and insect-parasited seeds along with a low seedling emergence and the exotic A. altissima was the species with more viable seeds and of higher germinability, no differences were found regarding these variables when comparing them with the native F. angustifolia. Unsuitable conditions might have hampered either seedling emergence and survival, as seedling abundance in the field was lower than expected in all species -especially in R. pseudoacacia-. Our results rather suggest that the sexual reproductive success was not higher in the exotic trees than in the native reference, but studies focusing on long-term recruitment would help to shed light on this issue.

  7. Reproductive strategies of two sympatric 'small barbs'(Barbus humilis and B. tanapelagius, Cyprinidae)in Lake Tana, Ethiopia

    NARCIS (Netherlands)

    Dejen, E.; Sibbing, F.A.; Vijverberg, J.

    2003-01-01

    The reproductive strategies of two species of 'small barbs' (12,000 fish). Both species have a long breeding period (from March to September), and the distinct bimodal size-frequency distributions of eggs suggest multiple spawning for both species. Absolute fecundity increased exponentially with

  8. External and internal modulators of sheep reproduction.

    Science.gov (United States)

    Blache, Dominique; Bickell, Samantha L

    2011-12-01

    Several factors such as season, genetics, social interaction and metabolic status control or modulate the reproductive capacity of sheep. In addition to these well-studied factors in sheep, the influence of emotional reactivity on the reproductive success of sheep has started to be investigated over the last two decades. In this paper, after briefly reviewing the impact of classical factors affecting reproduction in sheep, we define emotional reactivity and the expression of its inter-individual variability, named temperament. Then, following a description of the protocol to measure temperament in sheep and discussion on the heritability of temperament traits, we illustrate how this selection affects the reproductive biology of sheep. We will be mainly using results obtained from a unique flock of sheep selected for low or high emotional reactivity. In conclusion, we propose that energy partitioning could be one of the mechanisms by which selection for temperament in sheep affects the different steps of the reproductive cycle.

  9. Growth, chamber building rate and reproduction time of Palaeonummulites venosus under natural conditions.

    Science.gov (United States)

    Kinoshita, Shunichi; Eder, Wolfgang; Wöger, Julia; Hohenegger, Johann; Briguglio, Antonino

    2017-04-01

    Investigations on Palaeonummulites venosus using the natural laboratory approach for determining chamber building rate, test diameter increase rate, reproduction time and longevity is based on the decomposition of monthly obtained frequency distributions based on chamber number and test diameter into normal-distributed components. The shift of the component parameters 'mean' and 'standard deviation' during the investigation period of 15 months was used to calculate Michaelis-Menten functions applied to estimate the averaged chamber building rate and diameter increase rate under natural conditions. The individual dates of birth were estimated using the inverse averaged chamber building rate and the inverse diameter increase rate fitted by the individual chamber number or the individual test diameter at the sampling date. Distributions of frequencies and densities (i.e. frequency divided by sediment weight) based on chamber building rate and diameter increase rate resulted both in a continuous reproduction through the year with two peaks, the stronger in May /June determined as the beginning of the summer generation (generation1) and the weaker in November determined as the beginning of the winter generation (generation 2). This reproduction scheme explains the existence of small and large specimens in the same sample. Longevity, calculated as the maximum difference in days between the individual's birth date and the sampling date seems to be round about one year, obtained by both estimations based on the chamber building rate and the diameter increase rate.

  10. A Comparison of Dietary Intakes between Male and Female Korean American College Students: A Two Generation Study

    Science.gov (United States)

    Tam, Chick F.; Lew, PoLong; Schwartz, Miriam; Poon, George; An, JaeYoon; Lee, Jina; Chan, Katie; Li, Kenneth; Cheung, Yuen Ting; Luong, Duyen; Davis, Rebecca; Kim, James C.; Kim, Rachel Byungsook; Kim, Samuel Saychang

    2012-01-01

    The purpose of this study is to observe the differences in dietary intakes between two generations, male and female Korean American college students with their respective parents, living in the Los Angeles Areas. This study compared dietary nutrient intakes between old Koreans (KO) (n=28, average age: 53.4[plus or minus]6.4 years, with 13 males…

  11. Rethinking reproductive "tourism" as reproductive "exile".

    Science.gov (United States)

    Inhorn, Marcia C; Patrizio, Pasquale

    2009-09-01

    Whereas reproductive "tourism" implies leisure travel, reproductive "exile" bespeaks the numerous difficulties and constraints faced by infertile patients who are "forced" to travel globally for assisted reproduction. Given this reality, it is time to rethink the language of "reproductive tourism," replacing it with more accurate and patient-centered terms.

  12. Nutritional effects on reproductive performance of captive adult female coyotes (Canis latrans).

    Science.gov (United States)

    Gese, Eric M; Roberts, Beth M; Knowlton, Frederick F

    2016-02-01

    Interactions between animals and their environment are fundamental to ecological research. Field studies of coyote (Canis latrans) reproductive performance suggest mean litter size changes in response to prey abundance. However, this relationship has been assessed primarily by using carcasses collected from trappers. The objective of this study was to assess whether nutritional manipulation prior to mating affected reproduction in adult female coyotes. We examined the effects of caloric restriction during the 7 months prior to estrus on the reproductive rates of 11 captive female coyotes and the subsequent initial survival of pups through two reproductive cycles. This was a 2-year study with a cross-over design so each female was monitored for reproductive performance on each of the two diet treatments. We assessed the number of implantation scars, number of pups born, sex ratios of pups, average pup weight at birth and 2- and 6-weeks of age, and the survival rates between implantation and 2-weeks of age for two diet treatments. We found the mean number of implantation sites and pups whelped during a reproductive cycle was influenced by food-intake prior to conception. Additionally, we found evidence suggesting the effects of nutritional stress may persist for additional breeding cycles. We also provided evidence suggesting well-fed females tended to have more male pups. Understanding how environmental factors influence reproductive output may improve model predictions of coyote population dynamics. Published by Elsevier B.V.

  13. The Fundamental Structure and the Reproduction of Spiral Wave in a Two-Dimensional Excitable Lattice.

    Science.gov (United States)

    Qian, Yu; Zhang, Zhaoyang

    2016-01-01

    In this paper we have systematically investigated the fundamental structure and the reproduction of spiral wave in a two-dimensional excitable lattice. A periodically rotating spiral wave is introduced as the model to reproduce spiral wave artificially. Interestingly, by using the dominant phase-advanced driving analysis method, the fundamental structure containing the loop structure and the wave propagation paths has been revealed, which can expose the periodically rotating orbit of spiral tip and the charity of spiral wave clearly. Furthermore, the fundamental structure is utilized as the core for artificial spiral wave. Additionally, the appropriate parameter region, in which the artificial spiral wave can be reproduced, is studied. Finally, we discuss the robustness of artificial spiral wave to defects.

  14. A 'mystery client' evaluation of adolescent sexual and reproductive health services in health facilities from two regions in Tanzania.

    Directory of Open Access Journals (Sweden)

    Zaina Mchome

    Full Text Available Unwelcoming behaviours and judgemental attitudes have long been recognised as a barrier to young people's access to reproductive health services. Over the last decade youth friendly reproductive health services have been promoted and implemented world-wide. However, long term evidence of the impact of these programmes is lacking. We report the results of a large mystery client evaluation of adolescent sexual and reproductive health services in Tanzania, a country that has had a long established youth friendly policy. Forty-eight visits made to thirty-three health facilities were conducted by twelve young people (six in each region trained to perform three different scripted scenarios (i.e., condom request, information on sexually transmitted infections and family planning. The study revealed barriers in relation to poor signage and reception for services. In addition health workers demonstrated paternalistic attitudes as well as lack of knowledge about adolescent sexual and reproductive health services. In some cases, health workers discouraged young people from using services such as condoms and family planning methods. Lack of confidentiality and privacy were also noted to be common challenges for the young people involved. Intervention strategies that focus on changing health workers' mind-set in relation to adolescent sexual and reproductive health are crucial for ensuring quality provision of sexual and reproductive health services to young people. The study identified the importance of reception or signs at the health units, as this can facilitate young people's efforts in seeking sexual and reproductive health services. Likewise, improvement of health workers knowledge of existing policy and practice on sexual and reproductive health services and youth friendly services is much needed.

  15. A model for estimating the minimum number of offspring to sample in studies of reproductive success.

    Science.gov (United States)

    Anderson, Joseph H; Ward, Eric J; Carlson, Stephanie M

    2011-01-01

    Molecular parentage permits studies of selection and evolution in fecund species with cryptic mating systems, such as fish, amphibians, and insects. However, there exists no method for estimating the number of offspring that must be assigned parentage to achieve robust estimates of reproductive success when only a fraction of offspring can be sampled. We constructed a 2-stage model that first estimated the mean (μ) and variance (v) in reproductive success from published studies on salmonid fishes and then sampled offspring from reproductive success distributions simulated from the μ and v estimates. Results provided strong support for modeling salmonid reproductive success via the negative binomial distribution and suggested that few offspring samples are needed to reject the null hypothesis of uniform offspring production. However, the sampled reproductive success distributions deviated significantly (χ(2) goodness-of-fit test p value reproductive success distribution at rates often >0.05 and as high as 0.24, even when hundreds of offspring were assigned parentage. In general, reproductive success patterns were less accurate when offspring were sampled from cohorts with larger numbers of parents and greater variance in reproductive success. Our model can be reparameterized with data from other species and will aid researchers in planning reproductive success studies by providing explicit sampling targets required to accurately assess reproductive success.

  16. Sublethal effects of buprofezin on development and reproduction in the white-backed planthopper, Sogatella furcifera (Hemiptera: Delphacidae).

    Science.gov (United States)

    Ali, Ehsan; Liao, Xun; Yang, Peng; Mao, Kaikai; Zhang, Xiaolei; Shakeel, Muhammad; Salim, Abdalla M A; Wan, Hu; Li, Jianhong

    2017-12-05

    In the present study, the effects of sublethal concentrations of buprofezin on life-table traits of S. furcifera were evaluated for two consecutive generations (F0 and F1). Our results exhibited that the fecundity, life span (longevity) and hatchability of the F0 and F1 generations were significantly decreased at LC 30 compared to the control. However, copulation was not significantly affected for the F0 or F1 generations at sublethal concentrations. The female life span was affected negatively at both treatments in F0 and at LC 30 in F1, compared to the control. Furthermore, significant effects of the sublethal concentrations were found on the developmental rate of all instars except the 3 rd instar of F1. However, the pre-adult period, total pre-oviposition period (TPOP) and adult pre-oviposition period (APOP) significantly increased in F1 individuals at LC 30 and LC 10 compared to the control. Our findings revealed that demographic characters (survival rate, intrinsic rate of increase (ri), finite rate of increase (λ), net reproductive rate (R 0 ), and gross reproductive rate (GRR)) of the F1 generation (from F0 parents) significantly decreased compared to the untreated group; however, the generation time (T) increased at LC 10 . Therefore, the results suggested that buprofezin could adversely affect individuals in the successive generation.

  17. Regulation of reproduction by the circadian rhythms.

    Science.gov (United States)

    Zhang, Wen-Xiang; Chen, Si-Yu; Liu, Chang

    2016-12-25

    Mammals synchronize their circadian activity primarily to the cycles of light and darkness in the environment. Circadian rhythm is controlled by the central clock in the hypothalamic suprachiasmatic nucleus (SCN) and the peripheral clocks in various tissues. More importantly, the central clock can integrate photic/nonphotic signals to generate rhythmic outputs, and then drive the slave oscillators in peripheral tissues through neuroendocrine and behavioral signals. Human reproductive activities, as some other physiological functions, are controlled by the biological clocks. Accumulating lines of epidemiological and genetic evidence indicate that disruption of circadian clock can be directly involved in multiple pathological processes, including infertility. In this review, we mainly discuss the presence of a circadian clock in reproductive tissues and its roles in follicles development, ovulation, spermatogenesis, fertilization and embryo implantation, etc. As the increased shift work and assisted reproductive technologies possibly disrupt circadian rhythmicity to impact reproduction, the importance of circadian rhythms should be highlighted in the regulation of reproductive process.

  18. Studies on the growth and reproduction of cattle in the tropics

    International Nuclear Information System (INIS)

    Frisch, J.E.

    1990-01-01

    The results of a number of studies that had the long term aim of increasing the productivity of cattle in the tropics are reported. The studies were conducted on the B (Brahman), HS (interbred Hereford x Shorthorn), F 1 BX (first cross B x HS) and F n BX (interbred B x HS) lines. These breeds were used to demonstrate the origins of the heterosis that occurs in both the realized growth and the reproductive rate of Bos indicus x Bos taurus. Genetic and environmental factors that limit the realized reproductive rates were also investigated. The reproductive rate of cows of each breed that differed in lactation status during the breeding season was compared in contrasting environments. It was shown that the main limitation to HS achieving high realized reproductive rates was of environmental origin. For B cows, the main limitation was associated with the stress of lactation. Unsuccessful attempts were made to overcome this limitation by using progesterone releasing intravaginal devices alone or in combination with temporary calf weaning to try to induce a fertile oestrus. Improvement of the realized reproductive rates in the HS line was achieved by increasing their resistance to environmental stresses. The prospects for increasing the realized reproductive rate of maiden heifers by increasing their live weight at the start of their first breeding season were also investigated. About half of the heifers of each breed were implanted with the synthetic growth promotant Synovex 'H' on three occasions before the start of the breeding season. Although the live weight of all breeds increased in response to Synovex 'H', the magnitude of the response was dependent on the presence or absence of parasite control. Previously implanted heifers had a lower pregnancy rate than non-implanted heifers. 4 refs, 6 tabs

  19. Asexual reproduction induces a rapid and permanent loss of sexual reproduction capacity in the rice fungal pathogen Magnaporthe oryzae: results of in vitro experimental evolution assays

    Directory of Open Access Journals (Sweden)

    Saleh Dounia

    2012-03-01

    Full Text Available Abstract Background Sexual reproduction is common in eukaryotic microorganisms, with few species reproducing exclusively asexually. However, in some organisms, such as fungi, asexual reproduction alternates with episodic sexual reproduction events. Fungi are thus appropriate organisms for studies of the reasons for the selection of sexuality or clonality and of the mechanisms underlying this selection. Magnaporthe oryzae, an Ascomycete causing blast disease on rice, reproduces mostly asexually in natura. Sexual reproduction is possible in vitro and requires (i two strains of opposite mating types including (ii at least one female-fertile strain (i.e. a strain able to produce perithecia, the female organs in which meiosis occurs. Female-fertile strains are found only in limited areas of Asia, in which evidence for contemporary recombination has recently been obtained. We induced the forced evolution of four Chinese female-fertile strains in vitro by the weekly transfer of asexual spores (conidia between Petri dishes. We aimed to determine whether female fertility was rapidly lost in the absence of sexual reproduction and whether this loss was controlled genetically or epigenetically. Results All the strains became female-sterile after 10 to 19 rounds of selection under asexual conditions. As no single-spore isolation was carried out, the observed decrease in the production of perithecia reflected the emergence and the invasion of female-sterile mutants. The female-sterile phenotype segregated in the offspring of crosses between female-sterile evolved strains and female-fertile wild-type strains. This segregation was maintained in the second generation in backcrosses. Female-sterile evolved strains were subjected to several stresses, but none induced the restoration of female fertility. This loss of fertility was therefore probably due to genetic rather than epigenetic mechanisms. In competition experiments, female-sterile mutants produced similar

  20. Induction of Gonadotropins for Reproductive Control

    Directory of Open Access Journals (Sweden)

    Elza Ibrahim Auerkari

    2015-10-01

    Full Text Available Much of the recent research on gonadotropin – related control processes of reproduction and reproductive maturation has concentrated on the neuronal and molecular biology of gonadotropin release. The reproductive development of healthy mammals requires appropriate fetal develompment and migration of the neural network controlling and including the gonadotropin releasing hormone (GnRH – producing neurons that are needed to regulate GnRH and luteinizing hormone (LH release. GnRH is also necessary for the development of the gonadotropin – producing pituitary gland. The fetal gonads respon to GnRH – induced LH production by producing the gonadal steroids required for further reproductive differentiation. Pubertal maturation is characterised by increases in LH levels, representing the corresponding pulsatile release of GnRH. This GnRH pulse generator appears to be an intrinsic property of the arcuate nucleus at the medial basal hypothalamus. The generator activity can be mediated by the neurotransmitter aspartate which activates neurons of the hypothalamus, inducing acuate releases of GnRH and hence initiates puberty. A major factor in human reproductive maturation is the decrease in the age of puberty, caused by improvement of nutritional conditions due to the socio – economic development. This implies that the pubertal activation of GnRH secretion depends on metabolic conditions. Of the substances that mediate the metabolic condition to the neuronal network regulating GnRH secretion, the role of the neuropeptide Y (NPY appears instrumental : for healthy mammals less food means more NPY, and accumulated NPY makes food to become sex. NPY does this by regulating the appropriate hypothalamic functions including the neuroendocrine control of gonadotropin release.

  1. The National Women's Health Study: assembly and description of a population-based reproductive cohort

    Directory of Open Access Journals (Sweden)

    Prior Susan

    2004-08-01

    Full Text Available Abstract Background Miscarriage is a common event but is remarkably difficult to measure in epidemiological studies. Few large-scale population-based studies have been conducted in the UK. Methods This was a population-based two-stage postal survey of reproductive histories of adult women living in the United Kingdom in 2001, sampled from the electronic electoral roll. In Stage 1 a short "screening" questionnaire was sent to over 60,000 randomly selected women in order to identify those aged 55 and under who had ever been pregnant or ever attempted to achieve a pregnancy, from whom a brief reproductive history was requested. Stage 2 involved a more lengthy questionnaire requesting detailed information on every pregnancy (and fertility problems, and questions relating to socio-demographic, behavioural and other factors for the most recent pregnancy in order to examine risk factors for miscarriage. Data on stillbirth, multiple birth and maternal age are compared to national data in order to assess response bias. Results The response rate was 49% for Stage 1 and 73% for the more targeted Stage 2. A total of 26,050 questionnaires were returned in Stage 1. Of the 17,748 women who were eligible on the grounds of age, 27% reported that they had never been pregnant and had never attempted to conceive a child. The remaining 13,035 women reported a total of 30,661 pregnancies. Comparison of key reproductive indicators (stillbirth and multiple birth rates and maternal age at first birth with national statistics showed that the data look remarkably similar to the general population. Conclusions This study has enabled the assembly of a large population-based dataset of women's reproductive histories which appears unbiased compared to the general UK population and which will enable investigation of hard-to-measure outcomes such as miscarriage and infertility.

  2. Age at first reproduction and economic change in the context of differing kinship ecologies.

    Science.gov (United States)

    Leonetti, Donna L; Nath, Dilip C

    2009-01-01

    Kinship systems which tend to be based on ecologies of subsistence also assign differential power, privilege, and control to human connections that present pathways for manipulation of resource access and transfer. They can be used in this way to channel resource concentrations in women and hence their reproductive value. Thus, strategic female life course trade-offs and their timing are likely to be responsive to changing preferences for qualities in women as economic conditions change. Female life histories are studied in two ethnic groups with differing kinship systems in NE India where the competitive market economy is now being felt by most households. Patrilineal Bengali (599 women) practice patrilocal residence with village exogamy and matrilineal Khasi (656 women) follow matrilocal residence with village endogamy, both also normatively preferring three-generation extended households. These households have helpful senior women and significantly greater income. Age at first reproduction (AFR), achieved adult growth (height) and educational level (greater than 6 years or less) are examined in reproductive women, ages 16-50. In both groups, women residing normatively are older at AFR and taller than women residing nonnormatively. More education is also associated with senior women. Thus, normative residence may place a woman in the best reproductive location, and those with higher reproductive and productive potential are often chosen as households face competitive market conditions. In both groups residing in favorable reproductive locations is associated with a faster pace of fertility among women, as well as lower offspring mortality among Khasi, to compensate for a later start. 2009 Wiley-Liss, Inc.

  3. Functional Analysis of Nuclear Estrogen Receptors in Zebrafish Reproduction by Genome Editing Approach.

    Science.gov (United States)

    Lu, Huijie; Cui, Yong; Jiang, Liwen; Ge, Wei

    2017-07-01

    Estrogens signal through both nuclear and membrane receptors with most reported effects being mediated via the nuclear estrogen receptors (nERs). Although much work has been reported on nERs in the zebrafish, there is a lack of direct genetic evidence for their functional roles and importance in reproduction. To address this issue, we undertook this study to disrupt all three nERs in the zebrafish, namely esr1 (ERα), esr2a (ERβII), and esr2b (ERβI), by the genome-editing technology clustered regularly interspaced short palindromic repeats and its associated nuclease (CRISPR/Cas9). Using this loss-of-function genetic approach, we successfully created three mutant zebrafish lines with each nER knocked out. In addition, we also generated all possible double and triple knockouts of the three nERs. The phenotypes of these mutants in reproduction were analyzed in all single, double, and triple nER knockouts in both females and males. Surprisingly, all three single nER mutant fish lines display normal reproductive development and function in both females and males, suggesting functional redundancy among these nERs. Further analysis of double and triple knockouts showed that nERs, especially Esr2a and Esr2b, were essential for female reproduction, and loss of these two nERs led to an arrest of folliculogenesis at previtellogenic stage II followed by sex reversal from female to male. In addition, the current study also revealed a unique role for Esr2a in follicle cell proliferation and transdifferentiation, follicle growth, and chorion formation. Taken together, this study provides the most comprehensive genetic analysis for differential functions of esr1, esr2a, and esr2b in fish reproduction. Copyright © 2017 Endocrine Society.

  4. Assisted reproductive technology in the United States: 2001 results generated from the American Society for Reproductive Medicine/Society for Assisted Reproductive Technology registry.

    Science.gov (United States)

    2007-06-01

    To summarize the procedures and outcomes of assisted reproductive technologies (ART) that were initiated in the United States in 2001. Data were collected electronically using the Society for Assisted Reproductive Technology (SART) Clinic Outcome Reporting System software and submitted to the American Society for Reproductive Medicine/SART Registry. Three hundred eighty-five clinics submitted data on procedures performed in 2001. Data were collated after November 2002 [corrected] so that the outcomes of all pregnancies would be known. Incidence of clinical pregnancy, ectopic pregnancy, abortion, stillbirth, and delivery. Programs reported initiating 108,130 cycles of ART treatment. Of these, 79,042 cycles involved IVF (with and without micromanipulation), with a delivery rate per retrieval of 31.6%; 340 were cycles of gamete intrafallopian transfer, with a delivery rate per retrieval of 21.9%; 661 were cycles of zygote intrafallopian transfer, with a delivery rate per retrieval of 31.0%. The following additional ART procedures were also initiated: 8,147 fresh donor oocyte cycles, with a delivery rate per transfer of 47.3%; 14,509 frozen ET procedures, with a delivery rate per transfer of 23.5%; 3,187 frozen ETs employing donated oocytes or embryos, with a delivery rate per transfer of 27.4%; and 1,366 cycles using a host uterus, with a delivery rate per transfer of 38.7%. In addition, 112 cycles were reported as combinations of more than one treatment type, 8 cycles as research, and 85 as embryo banking. As a result of all procedures, 29,585 deliveries were reported, resulting in 41,168 neonates. In 2001, there were more programs reporting ART treatment and a significant increase in reported cycles compared with 2000.

  5. Safety and protective efficacy of porcine reproductive and respiratory syndrome recombinant virus vaccines in young pigs.

    NARCIS (Netherlands)

    Verheije, M.H.; Kroese, M.V.; Linden, van der I.F.A.; Boer-Luijtze, de E.A.; Rijn, van P.A.; Pol, J.M.A.; Meulenberg, J.J.M.; Steverink, P.J.G.M.

    2003-01-01

    Three porcine reproductive and respiratory syndrome virus (PRRSV) recombinants, generated by mutagenesis of an infectious cDNA clone of the Lelystad virus (LV) isolate, were tested for their safety and protective efficacy as potential PRRSV vaccines in pigs. Recombinant vABV688 contains two amino

  6. Decomposing variation in male reproductive success: age-specific variances and covariances through extra-pair and within-pair reproduction.

    Science.gov (United States)

    Lebigre, Christophe; Arcese, Peter; Reid, Jane M

    2013-07-01

    Age-specific variances and covariances in reproductive success shape the total variance in lifetime reproductive success (LRS), age-specific opportunities for selection, and population demographic variance and effective size. Age-specific (co)variances in reproductive success achieved through different reproductive routes must therefore be quantified to predict population, phenotypic and evolutionary dynamics in age-structured populations. While numerous studies have quantified age-specific variation in mean reproductive success, age-specific variances and covariances in reproductive success, and the contributions of different reproductive routes to these (co)variances, have not been comprehensively quantified in natural populations. We applied 'additive' and 'independent' methods of variance decomposition to complete data describing apparent (social) and realised (genetic) age-specific reproductive success across 11 cohorts of socially monogamous but genetically polygynandrous song sparrows (Melospiza melodia). We thereby quantified age-specific (co)variances in male within-pair and extra-pair reproductive success (WPRS and EPRS) and the contributions of these (co)variances to the total variances in age-specific reproductive success and LRS. 'Additive' decomposition showed that within-age and among-age (co)variances in WPRS across males aged 2-4 years contributed most to the total variance in LRS. Age-specific (co)variances in EPRS contributed relatively little. However, extra-pair reproduction altered age-specific variances in reproductive success relative to the social mating system, and hence altered the relative contributions of age-specific reproductive success to the total variance in LRS. 'Independent' decomposition showed that the (co)variances in age-specific WPRS, EPRS and total reproductive success, and the resulting opportunities for selection, varied substantially across males that survived to each age. Furthermore, extra-pair reproduction increased

  7. Improving performance of two-phase natural circulation loops by reducing of entropy generation

    International Nuclear Information System (INIS)

    Goudarzi, N.; Talebi, S.

    2015-01-01

    This paper aims to investigate the effects of various parameters on stability behavior and entropy generation through a two-phase natural circulation loop. Two-phase natural circulation systems have low driving head and, consequently, low heat removal capability. To have a higher thermodynamic efficiency, in addition to the stability analysis, minimization of entropy generation by loop should be taken into account in the design of these systems. In the present study, to investigate the stability behavior, the non-linear method (known as the direct solution method or time domain method) which is able to simulate the uniform and non-uniform diameter loops, was applied. To best calculate entropy generation rates, the governing equations of the entropy generation were solved analytically. The effects of various parameters such as operating conditions and geometrical dimensions on the stability behavior and the entropy generation in the two-phase natural circulation loop were then analyzed. - Highlights: • Effects of all important parameters on entropy generation of a loop are studied. • The governing equations of the entropy generation are solved analytically. • Effects of all important parameters on stability of a loop are investigated. • Improvement of two-phase natural circulation loop is investigated.

  8. Tributyltin impaired reproductive success in female zebrafish through disrupting oogenesis, reproductive behaviors and serotonin synthesis.

    Science.gov (United States)

    Xiao, Wei-Yang; Li, Ying-Wen; Chen, Qi-Liang; Liu, Zhi-Hao

    2018-07-01

    Tributyltin (TBT), an organotin acting as aromatase (Cyp19a1) inhibitor, has been found to disrupt gametogenesis and reproductive behaviors in several fish species. However, few studies addressing the mechanisms underlying the impaired gametogenesis and reproduction have been reported. In this study, female adults of zebrafish (Danio rerio) were continuously exposed to two nominal concentrations of TBT (100 and 500 ng/L, actual concentrations: 90.8 ± 1.3 ng/L and 470.3 ± 2.7 ng/L, respectively) for 28 days. After exposures, TBT decreased the total egg number, reduced the hatchability and elevated the mortality of the larvae. Decreased gonadosomatic index (GSI) and altered percentages of follicles in different developmental stages (increased early-stage follicles and reduced mid/late-stage follicles) were also observed in the ovary of TBT-treated fish. TBT also lowered the plasma level of 17β-estradiol and suppressed the expressions of cyp19a1a in the ovary. In treated fish, up-regulated expressions of aldhla2, sycp3 and dmc1 were present in the ovary, indicating an enhanced level of meiosis. The mRNA level of vtg1 was dramatically suppressed in the liver of TBT-treated fish, suggesting an insufficient synthesis of Vtg protein, consistent with the decreased percentage of mid/late-stage follicles in the ovaries. Moreover, TBT significantly suppressed the reproductive behaviors of the female fish (duration of both sexes simultaneously in spawning area, the frequency of meeting and the visit in spawning area) and down-regulated the mRNA levels of genes involved in the regulation of reproductive behaviors (cyp19a1b, gnrh-3 and kiss 2) in the brain. In addition, TBT significantly suppressed the expressions of serotonin-related genes, such as tph2 (encoding serotonin synthase), pet1 (marker of serotonin neuron) and kiss 1 (the modulator of serotonin synthesis), suggesting that TBT might disrupt the non-reproductive behaviors of zebrafish. The present

  9. Combined effect of education and reproductive history on weight trajectories of young Australian women: A longitudinal study.

    Science.gov (United States)

    Holowko, Natalie; Jones, Mark; Koupil, Ilona; Tooth, Leigh; Mishra, Gita

    2016-10-01

    To investigate the combined effect of education and reproductive history on weight trajectory. The association of education with weight trajectory (1996-2012) in relation to reproductive history was analyzed among 9,336 women (born 1973-1978) from the Australian Longitudinal Study on Women's Health using random effects models. Compared with women with a university degree/higher, lower-educated women were 2 kg heavier at baseline and gained an additional 0.24 kg/year. Giving birth was associated with an increase in weight which was more pronounced among women having their first birth 32 years. While younger first-time mothers had a steeper weight trajectory (∼+0.16 kg/year, 95% CI: 0.1-0.3), this was less steep among lower-educated women. High-educated women with a second birth between 26 and 32 years had 0.9 kg decreased weight after this birth, while low-educated women gained 0.9 kg. While the effect of having children on weight in young adulthood was minimal, women having their first birth women. Educational differences in weight persisted after accounting for reproductive history, suggesting a need to explore alternative mechanisms through which social differences in weight are generated. © 2016 The Obesity Society.

  10. Obsessive-compulsive disorder and female reproductive cycle events: results from the OCD and reproduction collaborative study

    NARCIS (Netherlands)

    Guglielmi, Valeria; Vulink, Nienke C. C.; Denys, Damiaan; Wang, Ying; Samuels, Jack F.; Nestadt, Gerald

    2014-01-01

    Women with obsessive-compulsive disorder (OCD) often report that symptoms first appear or exacerbate during reproductive cycle events; however, little is known about these relationships. The goals of this study were to examine, in a US and a European female OCD sample, onset and exacerbation of OCD

  11. Estimating reproduction numbers for adults and children from case data

    Science.gov (United States)

    Glass, K.; Mercer, G. N.; Nishiura, H.; McBryde, E. S.; Becker, N. G.

    2011-01-01

    We present a method for estimating reproduction numbers for adults and children from daily onset data, using pandemic influenza A(H1N1) data as a case study. We investigate the impact of different underlying transmission assumptions on our estimates, and identify that asymmetric reproduction matrices are often appropriate. Under-reporting of cases can bias estimates of the reproduction numbers if reporting rates are not equal across the two age groups. However, we demonstrate that the estimate of the higher reproduction number is robust to disproportionate data-thinning. Applying the method to 2009 pandemic influenza H1N1 data from Japan, we demonstrate that the reproduction number for children was considerably higher than that of adults, and that our estimates are insensitive to our choice of reproduction matrix. PMID:21345858

  12. Pupils' Perceptions of Sex and Reproductive Health Education in Primary Schools in Tanzania: A Phenomenological Study

    Science.gov (United States)

    Kapinga, Orestes Silverius; Hyera, Daniel Frans

    2015-01-01

    This study explored pupils' perceptions of sex and reproductive health education in primary schools in Tanzania. Specifically, the study aimed at (i) exploring pupils' views on sex and reproductive health education in primary schools; (ii) determining opinions on the appropriateness of sex and reproductive health education for pupils in primary…

  13. REPRODUCTIVE CHARACTERISTICS OF INDONESIA MAHSEER (Tor tambroides, Bleeker, 1854, IN TWO DIFFERENT RIVERS IN WESTERN SUMATERA

    Directory of Open Access Journals (Sweden)

    Arif Wibowo

    2014-12-01

    Full Text Available The reproductive characteristics of mahseer, Tor. tambroides, were studied in Manna River and Batang Tarusan River, which are located on each side of Western Sumatera River. The reproductive period of T. tambroides is largely consistent with that described for the species in other areas, however monthly variations in the extent and timing of peak spawning are recorded. The analysis of the sex ratio indicates an increase in the percentage of females with size, more marked in largest sizes. Seasonal patterns in the occurrences of spawning showed that the spawning season in Manna River lasted was similar with that in Batang Tarusan River, although a second prominent increase of GSI was observed in April and September in Manna River, meanwhile the GSI of Batang Tarusan River fish were below 2 without an apparent variation. L50s of Manna River and Batang Tarusan River mahseer were estimated as 24.5 cm and 20.66 cm, respectively, indicating a high variability in size at first maturity of the mahseer population. Our study provides some important information on the reproductive biology of T. tambroides that will be helpful in similar studies and contributed to fisheries management of this species.

  14. Generating demand and community support for sexual and reproductive health services for young people: A review of the Literature and Programs.

    Science.gov (United States)

    Kesterton, Amy J; Cabral de Mello, Meena

    2010-09-24

    This review investigates the effectiveness of interventions aimed at generating demand for and use of sexual and reproductive health (SRH) services by young people; and interventions aimed at generating wider community support for their use. Reports and publications were found in the peer-reviewed and grey literature through academic search engines; web searches; the bibliographies of known conference proceedings and papers; and consultation with experts. The studies were reviewed against a set of inclusion criteria and those that met these were explored in more depth. The evidence-base for interventions aimed at both generating demand and community support for SRH services for young people was found under-developed and many available studies do not provide strong evidence. However, the potential of several methods to increase youth uptake has been demonstrated, this includes the linking of school education programs with youth friendly services, life skills approaches and social marketing and franchising. There is also evidence that the involvement of key community gatekeepers such as parents and religious leaders is vital to generating wider community support. In general a combined multi-component approach seems most promising with several success stories to build on. Many areas for further research have been highlighted and there is a great need for more rigorous evaluation of programmes in this area. In particular, further evaluation of individual components within a multi-component approach is needed to elucidate the most effective interventions.

  15. Generating demand and community support for sexual and reproductive health services for young people: A review of the Literature and Programs

    Directory of Open Access Journals (Sweden)

    Cabral de Mello Meena

    2010-09-01

    Full Text Available Abstract Background This review investigates the effectiveness of interventions aimed at generating demand for and use of sexual and reproductive health (SRH services by young people; and interventions aimed at generating wider community support for their use. Methods Reports and publications were found in the peer-reviewed and grey literature through academic search engines; web searches; the bibliographies of known conference proceedings and papers; and consultation with experts. The studies were reviewed against a set of inclusion criteria and those that met these were explored in more depth. Results The evidence-base for interventions aimed at both generating demand and community support for SRH services for young people was found under-developed and many available studies do not provide strong evidence. However, the potential of several methods to increase youth uptake has been demonstrated, this includes the linking of school education programs with youth friendly services, life skills approaches and social marketing and franchising. There is also evidence that the involvement of key community gatekeepers such as parents and religious leaders is vital to generating wider community support. In general a combined multi-component approach seems most promising with several success stories to build on. Conclusions Many areas for further research have been highlighted and there is a great need for more rigorous evaluation of programmes in this area. In particular, further evaluation of individual components within a multi-component approach is needed to elucidate the most effective interventions.

  16. Generating demand and community support for sexual and reproductive health services for young people: A review of the Literature and Programs

    Science.gov (United States)

    2010-01-01

    Background This review investigates the effectiveness of interventions aimed at generating demand for and use of sexual and reproductive health (SRH) services by young people; and interventions aimed at generating wider community support for their use. Methods Reports and publications were found in the peer-reviewed and grey literature through academic search engines; web searches; the bibliographies of known conference proceedings and papers; and consultation with experts. The studies were reviewed against a set of inclusion criteria and those that met these were explored in more depth. Results The evidence-base for interventions aimed at both generating demand and community support for SRH services for young people was found under-developed and many available studies do not provide strong evidence. However, the potential of several methods to increase youth uptake has been demonstrated, this includes the linking of school education programs with youth friendly services, life skills approaches and social marketing and franchising. There is also evidence that the involvement of key community gatekeepers such as parents and religious leaders is vital to generating wider community support. In general a combined multi-component approach seems most promising with several success stories to build on. Conclusions Many areas for further research have been highlighted and there is a great need for more rigorous evaluation of programmes in this area. In particular, further evaluation of individual components within a multi-component approach is needed to elucidate the most effective interventions. PMID:20863411

  17. Reproductive isolation of sympatric forms of the understorey palm Geonoma macrostachys in western Amazonia

    DEFF Research Database (Denmark)

    Borchsenius, Finn; Lozada, Tannya; Knudsen, Jette T.

    2016-01-01

    The evolution of a mechanism for attaining reproductive isolation between two diverging populations is a key step in the speciation process. We studied phenotypic variation, genetic differentiation, spatial distribution and reproductive ecology in two sympatric forms of the understorey palm Geonoma...

  18. Reproductive acclimation to increased water temperature in a tropical reef fish.

    Directory of Open Access Journals (Sweden)

    Jennifer M Donelson

    Full Text Available Understanding the capacity of organisms to cope with projected global warming through acclimation and adaptation is critical to predicting their likely future persistence. While recent research has shown that developmental acclimation of metabolic attributes to ocean warming is possible, our understanding of the plasticity of key fitness-associated traits, such as reproductive performance, is lacking. We show that while the reproductive ability of a tropical reef fish is highly sensitive to increases in water temperature, reproductive capacity at +1.5°C above present-day was improved to match fish maintained at present-day temperatures when fish complete their development at the higher temperature. However, reproductive acclimation was not observed in fish reared at +3.0°C warmer than present-day, suggesting limitations to the acclimation possible within one generation. Surprisingly, the improvements seen in reproduction were not predicted by the oxygen- and capacity-limited thermal tolerance hypothesis. Specifically, pairs reared at +1.5°C, which showed the greatest capacity for reproductive acclimation, exhibited no acclimation of metabolic attributes. Conversely, pairs reared at +3.0°C, which exhibited acclimation in resting metabolic rate, demonstrated little capacity for reproductive acclimation. Our study suggests that understanding the acclimation capacity of reproductive performance will be critically important to predicting the impacts of climate change on biological systems.

  19. Fish reproduction

    National Research Council Canada - National Science Library

    Rocha, Maria João; Arukwe, Augustine; Kapoor, B. G

    2008-01-01

    ... of reproductive systems is essential for such studies. Fishes comprise over 28,000 species, with a remarkable variability in morphology, physiology and environmental adaptation. Knowledge on fish reproduction is scattered across numerous sources that shows a dynamic research field. The Editors believe it to be an opportune moment for a...

  20. [Fitness of sexual reproduction of Toona ciliata var. pubescens natural populations and their sexual reproduction and regeneration].

    Science.gov (United States)

    Huang, Hong Lan; Zhang, Lu; Jia, Li Ming; Liang, Yue-Long; Cai, Jun Huo

    2018-04-01

    To examine the reproduction fitness coefficients and individual-level fitness of Toona ciliata var. pubescens, their sexual reproduction and natural regeneration were investigated during 2006-2016, with four natural populations in Jiulianshan National Reserve as test objects. The results showed that there were only 2-10 trees for the natural populations of T. ciliata var. pubescens with a small initial number of fruiting plants (3-9 trees), which were from the initial fruiting plants or their first/second generation. The sexual reproduction of these isolated populations were significantly different, and their seed production capacities tended to decline over time. With the maturing of communities, soil seed banks and seed germinations were extremely poor, and the number of trees that could be growing to mature stage was nearly zero. The optimum maturity age of T. ciliata var. pubescens was about 40 a, and the fitness coefficients (2.0-2.8) rapidly increased in early development stage, but then was sharply reduced (0.3-0.5), and then gradually dropped to almost 0. There were significant differences in the fitness at individual level (0-14 tree·cm -2 ) among different populations, but their values were low (close to zero). Based on the existing reproduction rate, the actual values of sexual reproduction and regeneration fitness were much lower than the predicted ones. Due to the low level of genetic fitness, the sexual reproductive ability of different populations all showed decreasing trends. The natural sexual regeneration ability tended to decline, while the fitness of T. ciliata var. pubescens further decreased. All those factors suggested higher investment risks. Therefore, the systems of sexual reproduction became unbalanced and deteriorating. We proposed that more studies, including breeding mating, pollination, seed setting, and genetic diversity evaluation, are needed. Moreover, we should provide suitable forest environment through cleaning up litter in the

  1. Contrasted patterns of age-specific reproduction in long-lived seabirds.

    Science.gov (United States)

    Berman, M; Gaillard, J-M; Weimerskirch, H

    2009-01-22

    While the number of studies providing evidence of actuarial senescence is increasing, and covers a wide range of taxa, the process of reproductive senescence remains poorly understood. In fact, quite high reproductive output until the last years of life has been reported in several vertebrate species, so that whether or not reproductive senescence is widespread remains unknown. We compared age-specific changes of reproductive parameters between two closely related species of long-lived seabirds: the small-sized snow petrel Pagodroma nivea, and the medium-sized southern fulmar Fulmarus glacialoides. Both are sympatric in Antarctica. We used an exceptional dataset collected over more than 40 years to assess age-specific variations of both breeding probability and breeding success. We found contrasted age-specific reproductive patterns between the two species. Reproductive senescence clearly occurred from 21 years of age onwards in the southern fulmar, in both breeding probability and success, whereas we did not report any decline in the breeding success of the snow petrel, although a very late decrease in the proportion of breeders occurred at 34 years. Such a contrasted age-specific reproductive pattern was rather unexpected. Differences in life history including size or migratory behaviour are the most likely candidates to account for the difference we reported in reproductive senescence between these sympatric seabird species.

  2. Reproduction and subchronic feeding study of carnauba wax in rats.

    Science.gov (United States)

    Parent, R A; Re, T A; Babish, J G; Cox, G E; Voss, K A; Becci, P J

    1983-02-01

    The reproductive performance of Wistar rats fed carnauba wax at levels of 0.1, 0.3 or 1% in the diet and the effects of subchronic administration of carnauba wax at these dose levels on the resultant progeny were studied. Reproductive indices, body-weight gain, food consumption, haematological and clinical chemical data, ophthalmic, gross and histopathological examinations were used to study the possible toxic or pathological effects. Serum free fatty acid levels were found to be decreased in male and female rats fed carnauba wax at dietary levels of 0.3 and 1.0%. No other effects of feeding carnauba wax at levels up to 1.0% of the diet were observed.

  3. Evaluation of the impact of the voucher and accreditation approach on improving reproductive health behaviors and status in Kenya.

    Science.gov (United States)

    Warren, Charlotte; Abuya, Timothy; Obare, Francis; Sunday, Joseph; Njue, Rebecca; Askew, Ian; Bellows, Ben

    2011-03-23

    Alternatives to the traditional 'supply-side' approach to financing service delivery are being explored. These strategies are termed results-based finance, demand-side health financing or output-based aid which includes a range of interventions that channel government or donor subsidies to the user rather than the provider. Initial pilot assessments of reproductive health voucher programs suggest that, they can increase access and use, reducing inequities and enhancing program efficiency and service quality. However, there is a paucity of evidence describing how the programs function in different settings, for various reproductive health services. Population Council, funded by the Bill and Melinda Gates Foundation, intends to generate evidence around the 'voucher and accreditation' approaches to improving the reproductive health of low income women in Kenya. A quasi-experimental study will investigate the impact of the voucher approach on improving reproductive health behaviors, reproductive health status and reducing inequities at the population level; and assessing the effect of vouchers on increasing access to, and quality of, and reducing inequities in the use of selected reproductive health services. The study comprises of four populations: facilities, providers, women of reproductive health age using facilities and women and men who have been pregnant and/or used family planning within the previous 12 months. The study will be carried out in samples of health facilities - public, private and faith-based in: three districts; Kisumu, Kiambu, Kitui and two informal settlements in Nairobi which are accredited to provide maternal and newborn health and family planning services to women holding vouchers for the services; and compared with a matched sample of non-accredited facilities. Health facility assessments (HFA) will be conducted at two stages to track temporal changes in quality of care and utilization. Facility inventories, structured observations, and

  4. Collection of field reproductive data from carcasses of the female Eurasian lynx (Lynx lynx).

    Science.gov (United States)

    Axnér, E; Payan-Carreira, R; Setterlind, P; Åsbrink, J; Söderberg, A

    2013-11-01

    Information about reproductive physiology in the Eurasian lynx (Lynx lynx) would generate knowledge that could be useful in the management of the Swedish lynx population based on the knowledge about their reproductive potential and population development. Age-related differences in ovulation and implantation rates would affect the reproductive output and the development of the population. The aims of this study were to evaluate a protocol for collection of reproductive data from carcasses by comparisons with published field data and to generate data about reproduction in the Swedish lynx. Reproductive organs from 120 females that were harvested between March 1 and April 9 from 2009 to 2011 were collected and evaluated macroscopically for placental scars. Females had their first estrus as yearlings but did not have their first litter until the next season. Pregnancy rates were lower in 2-year-old females than in females aged 3 to 7 years but did not differ significantly from females aged 8 to 13 years (54.5%, 95.6%, and 75.0%, respectively). CL from the present season were morphologically distinctly different from luteal bodies from previous cycles (LBPC). All females ≥3 years had macroscopically visible LBPC, whereas only 67% of 22 to 23 months old females had one to three LBPC and no females number of LBPC counted in females ≥3 years of age was 11. These data would be in agreement with only one estrus per season and LBPC from at least three previous reproductive seasons in older females. The number of LBPC was significantly correlated with the weight of the ovaries rs = 0.648, P reproductive cycle and was highest for mature females in the luteal phase of the cycle. The estrous period, defined as occurrence of ovarian follicles lasted from March 5 to April 1 in this material. In conclusion, this study confirms that useful information about lynx reproduction can be collected from reproductive organs retrieved after the death of the animals. Continuous monitoring

  5. Changes in male reproductive health and effects of endocrine disruptors in Scandinavian countries

    Directory of Open Access Journals (Sweden)

    Toppari Jorma

    2002-01-01

    Full Text Available Male reproductive health has deteriorated in many ways during the last decades. The incidence of testicular cancer has rapidly increased in Europe and European-derived populations. Sperm concentrations have declined and sperm motility and morphology have worsened in many areas. Both adverse trends have been shown to be associated with year of birth. Older birth cohorts have better reproductive health than the younger generations. Incidences of cryptorchidism and hypospadias have also increased according to several studies. The reasons for secular trends are unknown, but the rapid pace of the change points to environmental causes. Endocrine disrupting chemicals have been hypothesized to influence male reproductive health.

  6. Effect of uranium on growth and reproduction of the marine amphipod Allorchestes compressa

    International Nuclear Information System (INIS)

    Ahsanullah, M.; Williams, A.R.

    1986-01-01

    Experiments on growth of the marine amphipod Allorchestes compressa Dana were carried out over four weeks, and both growth and reproduction were studied over three generations, each of which was exposed to uranium for approximately 10 wk. At 0.1 mg l -1 the uranium increased growth by 23%, as measured by the mean weight after 4 wk, and at 2 mg l -1 growth was reduced by 28% compared with the control. A. compressa accumulated uranium from sea water with a concentration factor of 10. There was no effect of uranium on the survival of amphipods or their progeny in the multiple-generation experiment, but the numbers of males, the sex ratio, and the respiration rate (measured on males only) at 1 mg l -1 were significantly lower than the control. A. compressa is shown to be a convenient species for the study of toxic effects on growth and reproduction using multiple-generation experiments. (orig.)

  7. Challenges of monitoring reproductive health services: a case study ...

    African Journals Online (AJOL)

    Challenges of monitoring reproductive health services: a case study of antenatal clinics in Kinondoni municipality, Dar Es Salaam. ... was descriptive cross sectional employing both qualitative and quantitative methods. The sample population included nurse-midwives who manage ANC clinics in Kinondoni Municipality.

  8. Invited review: Recommendations for reporting intervention studies on reproductive performance in dairy cattle: Improving design, analysis, and interpretation of research on reproduction.

    Science.gov (United States)

    Lean, Ian J; Lucy, Matthew C; McNamara, John P; Bradford, Barry J; Block, Elliot; Thomson, Jennifer M; Morton, John M; Celi, Pietro; Rabiee, Ahmad R; Santos, José E P; Thatcher, William W; LeBlanc, Stephen J

    2016-01-01

    Abundant evidence from the medical, veterinary, and animal science literature demonstrates that there is substantial room for improvement of the clarity, completeness, and accuracy of reporting of intervention studies. More rigorous reporting guidelines are needed to improve the quality of data available for use in comparisons of outcomes (or meta-analyses) of multiple studies. Because of the diversity of factors that affect reproduction and the complexity of interactions between these, a systematic approach is required to design, conduct, and analyze basic and applied studies of dairy cattle reproduction. Greater consistency, clarity, completeness, and correctness of design and reporting will improve the value of each report and allow for greater depth of evaluation in meta-analyses. Each of these benefits will improve understanding and application of current knowledge and better identify questions that require additional modeling or primary research. The proposed guidelines and checklist will aid in the design, conduct, analysis, and reporting of intervention studies. We propose an adaptation of the REFLECT (Reporting Guidelines for Randomized Controlled Trials for Livestock and Food Safety) statement to provide guidelines and a checklist specific to reporting intervention studies in dairy cattle reproduction. Furthermore, we provide recommendations that will assist investigators to produce studies with greater internal and external validity that can more often be included in systematic reviews and global meta-analyses. Such studies will also assist the development of models to describe the physiology of reproduction. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. Utility of RNA Sequencing for Analysis of Maize Reproductive Transcriptomes

    Directory of Open Access Journals (Sweden)

    Rebecca M. Davidson

    2011-11-01

    Full Text Available Transcriptome sequencing is a powerful method for studying global expression patterns in large, complex genomes. Evaluation of sequence-based expression profiles during reproductive development would provide functional annotation to genes underlying agronomic traits. We generated transcriptome profiles for 12 diverse maize ( L. reproductive tissues representing male, female, developing seed, and leaf tissues using high throughput transcriptome sequencing. Overall, ∼80% of annotated genes were expressed. Comparative analysis between sequence and hybridization-based methods demonstrated the utility of ribonucleic acid sequencing (RNA-seq for expression determination and differentiation of paralagous genes (∼85% of maize genes. Analysis of 4975 gene families across reproductive tissues revealed expression divergence is proportional to family size. In all pairwise comparisons between tissues, 7 (pre- vs. postemergence cobs to 48% (pollen vs. ovule of genes were differentially expressed. Genes with expression restricted to a single tissue within this study were identified with the highest numbers observed in leaves, endosperm, and pollen. Coexpression network analysis identified 17 gene modules with complex and shared expression patterns containing many previously described maize genes. The data and analyses in this study provide valuable tools through improved gene annotation, gene family characterization, and a core set of candidate genes to further characterize maize reproductive development and improve grain yield potential.

  10. Symbiotic regulation of plant growth, development and reproduction

    Science.gov (United States)

    Rodriguez, R.J.; Freeman, D. Carl; McArthur, E.D.; Kim, Y.-O.; Redman, R.S.

    2009-01-01

    The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at five times the rate observed in nonsymbiotic plants. Endophytes also influenced sexual reproduction of mature big sagebrush (Artemisia tridentata) plants. Two spatially distinct big sagebrush subspecies and their hybrids were symbiotic with unique fungal endophytes, despite being separated by only 380 m distance and 60 m elevation. A double reciprocal transplant experiment of parental and hybrid plants, and soils across the hybrid zone showed that fungal endophytes interact with the soils and different plant genotypes to confer enhanced plant reproduction in soil native to the endophyte and reduced reproduction in soil alien to the endophyte. Moreover, the most prevalent endophyte of the hybrid zone reduced the fitness of both parental subspecies. Because these endophytes are passed to the next generation of plants on seed coats, this interaction provides a selective advantage, habitat specificity, and the means of restricting gene flow, thereby making the hybrid zone stable, narrow and potentially leading to speciation. ?? 2009 Landes Bioscience.

  11. Evaluation of school-based reproductive health education program for adolescent girls.

    Science.gov (United States)

    Golbasi, Zehra; Taskin, Lale

    2009-01-01

    To evaluate the effectiveness of school-based reproductive health education for adolescent girls on the reproductive knowledge level of the girls. This research was carried out as a quasi-experimental study at two vocational girls high schools, one of which was used as the study school and the other as the control school. The study group (97 students) consisted of three classes representing every grade. The control group consisted of students selected likewise (92 students). Reproductive health education was given to students in the study group for 10 weeks; the control group was not subjected to any educational program. The impact of the program was evaluated with reproductive health knowledge test designed for this study. A pretest evaluated baseline knowledge, and a posttest measured the gain in knowledge. Baseline knowledge score of students in study and control group were similar and low (p > 0.05). We found that the reproductive health knowledge level of students in the study group increased significantly after the program of education. Post-test knowledge scores (75.03 +/- 13.82) of the students in the study group were higher than those of the control group (36.65 +/- 14.17). The results showed students' low baseline knowledge and a good ability to learn. A school-based reproductive health education is needed to promote knowledge and prevention in reproductive health among teenagers.

  12. The transcriptome of Lutzomyia longipalpis (Diptera: Psychodidae) male reproductive organs.

    Science.gov (United States)

    Azevedo, Renata V D M; Dias, Denise B S; Bretãs, Jorge A C; Mazzoni, Camila J; Souza, Nataly A; Albano, Rodolpho M; Wagner, Glauber; Davila, Alberto M R; Peixoto, Alexandre A

    2012-01-01

    It has been suggested that genes involved in the reproductive biology of insect disease vectors are potential targets for future alternative methods of control. Little is known about the molecular biology of reproduction in phlebotomine sand flies and there is no information available concerning genes that are expressed in male reproductive organs of Lutzomyia longipalpis, the main vector of American visceral leishmaniasis and a species complex. We generated 2678 high quality ESTs ("Expressed Sequence Tags") of L. longipalpis male reproductive organs that were grouped in 1391 non-redundant sequences (1136 singlets and 255 clusters). BLAST analysis revealed that only 57% of these sequences share similarity with a L. longipalpis female EST database. Although no more than 36% of the non-redundant sequences showed similarity to protein sequences deposited in databases, more than half of them presented the best-match hits with mosquito genes. Gene ontology analysis identified subsets of genes involved in biological processes such as protein biosynthesis and DNA replication, which are probably associated with spermatogenesis. A number of non-redundant sequences were also identified as putative male reproductive gland proteins (mRGPs), also known as male accessory gland protein genes (Acps). The transcriptome analysis of L. longipalpis male reproductive organs is one step further in the study of the molecular basis of the reproductive biology of this important species complex. It has allowed the identification of genes potentially involved in spermatogenesis as well as putative mRGPs sequences, which have been studied in many insect species because of their effects on female post-mating behavior and physiology and their potential role in sexual selection and speciation. These data open a number of new avenues for further research in the molecular and evolutionary reproductive biology of sand flies.

  13. Assessment in rats of the reproductive toxicity of gasoline from a gasoline vapor recovery unit.

    Science.gov (United States)

    McKee, R H; Trimmer, G W; Whitman, F T; Nessel, C S; Mackerer, C R; Hagemann, R; Priston, R A; Riley, A J; Cruzan, G; Simpson, B J; Urbanus, J H

    2000-01-01

    Gasoline (CAS 86290-81-5) is one of the world's largest volume commercial products. Although numerous toxicology studies have been conducted, the potential for reproductive toxicity has not been directly assessed. Accordingly, a two-generation reproductive toxicity study in rats was conducted to provide base data for hazard assessment and risk characterization. The test material, vapor recovery unit gasoline (68514-15-8), is the volatile fraction of formulated gasoline and the material with which humans are most likely to come in contact. The study was of standard design. Exposures were by inhalation at target concentrations of 5000, 10 000, and 20 000 mg/m(3). The highest exposure concentration was approximately 50% of the lower explosive limit and several orders of magnitude above anticipated exposure during refueling. There were no treatment-related clinical or systemic effects in the parental animals, and no microscopic changes other than hyaline droplet nephropathy in the kidneys of the male rats. None of the reproductive parameters were affected, and there were no deleterious effects on offspring survival and growth. The potential for endocrine modulation was also assessed by analysis of sperm count and quality as well as time to onset of developmental landmarks. No toxicologically important differences were found. Therefore, the NOAEL for reproductive toxicity in this study was > or =20 000 mg/m(3). The only systemic effects, in the kidneys of the male rats, were consistent with an alpha-2 u-globulin-mediated process. This is a male rat-specific effect and not relevant to human health risk assessment.

  14. Impact of stress on female reproductive health disorders: Possible beneficial effects of shatavari (Asparagus racemosus).

    Science.gov (United States)

    Pandey, Ajai K; Gupta, Anumegha; Tiwari, Meenakshi; Prasad, Shilpa; Pandey, Ashutosh N; Yadav, Pramod K; Sharma, Alka; Sahu, Kankshi; Asrafuzzaman, Syed; Vengayil, Doyil T; Shrivastav, Tulsidas G; Chaube, Shail K

    2018-07-01

    Stress is deeply rooted in the society and women are frequently exposed to psychological, physical and physiological stressors. Psychological stress disturbs reproductive health by inducing generation of reactive oxygen species (ROS) and thereby oxidative stress (OS). The increased OS may affect physiology of ovary, oocyte quality and cause female reproductive health disorders. To overcome stress-mediated reproductive health disorders in women, shatavari (Asparagus racemosus) is frequently recommended in Ayurvedic system of medicine. Although shatavari is one of the major health tonics and most popular rasayana drugs to treat reproductive ailments of women, underlying mechanism of shatavari action at the level of ovary remains poorly understood. Based on the existing studies, we propose that shatavari may improve female reproductive health complications including hormonal imbalance, polycystic ovarian syndrome (PCOS), follicular growth and development, oocyte quality and infertility possibly by reducing OS level and increasing antioxidants level in the body. Further studies are required to elucidate the mechanism of shatavari actions at the level of ovary and oocyte that directly impacts the reproductive health of women. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  15. Characterization of a male reproductive transcriptome for Peromyscus eremicus (Cactus mouse

    Directory of Open Access Journals (Sweden)

    Lauren L. Kordonowy

    2016-10-01

    Full Text Available Rodents of the genus Peromyscus have become increasingly utilized models for investigations into adaptive biology. This genus is particularly powerful for research linking genetics with adaptive physiology or behaviors, and recent research has capitalized on the unique opportunities afforded by the ecological diversity of these rodents. Well characterized genomic and transcriptomic data is intrinsic to explorations of the genetic architecture responsible for ecological adaptations. Therefore, this study characterizes the transcriptome of three male reproductive tissues (testes, epididymis and vas deferens of Peromyscus eremicus (Cactus mouse, a desert specialist. The transcriptome assembly process was optimized in order to produce a high quality and substantially complete annotated transcriptome. This composite transcriptome was generated to characterize the expressed transcripts in the male reproductive tract of P. eremicus, which will serve as a crucial resource for future research investigating our hypothesis that the male Cactus mouse possesses an adaptive reproductive phenotype to mitigate water-loss from ejaculate. This study reports genes under positive selection in the male Cactus mouse reproductive transcriptome relative to transcriptomes from Peromyscus maniculatus (deer mouse and Mus musculus. Thus, this study expands upon existing genetic research in this species, and we provide a high quality transcriptome to enable further explorations of our proposed hypothesis for male Cactus mouse reproductive adaptations to minimize seminal fluid loss.

  16. Mental Health and Hmong Americans: A comparison of two generations

    Directory of Open Access Journals (Sweden)

    Pa Der Vang

    2014-12-01

    Full Text Available Early studies of Hmong refugees in the U.S. indicated high rates of mental distress related to post-migration stressors such as grief and loss, poverty, and social adversity. This study explores the mental health status of two generations of Hmong Americans 38 years after their first migration. The relationship between acculturation and mental health of 191 1st and 2nd generation Hmong are reported. Results indicated relatively low reports of depressive symptoms and medium to high rates of acculturation to American society. The results are unrelated to demographic factors indicating resilience and adaptation to Western society despite age and generational status and maintenance of culture of origin

  17. In vitro comparison of noise levels produced by different CPAP generators.

    Science.gov (United States)

    Kirchner, Lieselotte; Wald, Martin; Jeitler, Valerie; Pollak, Arnold

    2012-01-01

    Minimization of noise exposure is an important aim of modern neonatal intensive care medicine. Binasal continuous positive airway pressure (CPAP) generators are among the most important sources of continuous noise in neonatal wards. The aim of this study was to find out which CPAP generator creates the least noise. In an experimental setup, two jet CPAP generators (Infant Flow® generator and MediJet®) and two conventional CPAP generators (Bubble CPAP® and Baby Flow®) were compared. Noise production was measured in decibels in an A-weighted scale [dB(A)] in a closed incubator at 2 mm lateral distance from the end of the nasal prongs. Reproduction of constant airway pressure and air leak was achieved by closure of the nasal prongs with a type of adhesive tape that is semipermeable to air. The noise levels produced by the four generators were significantly different (p CPAP® and 55 dB(A) for the Baby Flow®. Conventional CPAP generators work more quietly than the currently available jet CPAP generators. Copyright © 2011 S. Karger AG, Basel.

  18. Genetics of reproduction and regulation of honeybee (Apis mellifera L.) social behavior.

    Science.gov (United States)

    Page, Robert E; Rueppell, Olav; Amdam, Gro V

    2012-01-01

    Honeybees form complex societies with a division of labor for reproduction, nutrition, nest construction and maintenance, and defense. How does it evolve? Tasks performed by worker honeybees are distributed in time and space. There is no central control over behavior and there is no central genome on which selection can act and effect adaptive change. For 22 years, we have been addressing these questions by selecting on a single social trait associated with nutrition: the amount of surplus pollen (a source of protein) that is stored in the combs of the nest. Forty-two generations of selection have revealed changes at biological levels extending from the society down to the level of the gene. We show how we constructed this vertical understanding of social evolution using behavioral and anatomical analyses, physiology, genetic mapping, and gene knockdowns. We map out the phenotypic and genetic architectures of food storage and foraging behavior and show how they are linked through broad epistasis and pleiotropy affecting a reproductive regulatory network that influences foraging behavior. This is remarkable because worker honeybees have reduced reproductive organs and are normally sterile; however, the reproductive regulatory network has been co-opted for behavioral division of labor.

  19. Cost of reproduction in a long-lived bird: incubation effort reduces immune function and future reproduction

    OpenAIRE

    Hanssen, S A; Hasselquist, Dennis; Folstad, I; Erikstad, K E

    2005-01-01

    Life-history theory predicts that increased current reproductive effort should lead to a fitness cost. This cost of reproduction may be observed as reduced survival or future reproduction, and may be caused by temporal suppression of immune function in stressed or hard-working individuals. In birds, consideration of the costs of incubating eggs has largely been neglected in favour of the costs of brood rearing. We manipulated incubation demand in two breeding seasons (2000 and 2001) in female...

  20. Contraceptive method choice and use by married women of reproductive age in two Districts of East Harerge.

    Science.gov (United States)

    Dubiwak, Rahel; Seme, Assefa

    2014-01-01

    Contraceptive method mix and choice is not uniform across all countries. Literatures have shown that a significant variation exists in contraceptive method mix among regions and countries. In Africa most mothers rely on short-term contraceptives such as pills and injectables or traditional methods while in Asia and Latin America permanent methods mainly male and female sterilizations are commonly used. Though long-term methods of contraception are recommended for its effectiveness and efficiencies in countries like Ethiopia where high fertility rate is a concern, its choice and utilization remains low. The main objective of the study was to assess factors influencing contraceptive method choice and use among married women of reproductive age in rural Districts of East Harerge Zone of Oromia Region. A community-based cross-sectional study using both quantitative and qualitative methods was conducted among 473 married women of reproductive age in two rural districts of East Harerge Zone. A systematic random sampling method was used to select the study participants from the list of all married women who have been using contraceptives in the project sites. Data was collected using structured and pretested questionnaires. Data entry and analysis was done using EPI Info version 6.04d and SPSS for Windows version 15, respectively. Frequencies and proportions were used for description while odds ratio with 95% CI was used to determine the strength and significance of association between independent and outcome variables. Multiple logistic regression analysis was used to control confounding variables. A total of 473 currently married women who were using modern contraceptives were interviewed for the survey. About 6 in ten (58.8%) were in the age range of 25-34 years with the mean (+/- SD) age of 29.5 (+/- 5.7) years. About three-fourth (74%) were short-term contraceptive method users while only 26% were long-term contraceptive method users. Duration of family planning use

  1. Environment, human reproduction, menopause, and andropause.

    OpenAIRE

    Vermeulen, A

    1993-01-01

    As the hypothalamic gonadotropin-releasing hormone (GnRH) pulse generator is an integrator of hormonal, metabolic, and neural signals, it is not surprising that the function of the hypothalamogonadal axis is subject to the influence of a large array of environmental factors. Before puberty, the central nervous system (CNS) restrains the GnRH pulse generator. Undernutrition, low socioeconomic status, stress, and emotional deprivation, all delay puberty. During reproductive life, among peripher...

  2. Asymmetric changes of growth and reproductive investment herald altitudinal and latitudinal range shifts of two woody species.

    Science.gov (United States)

    Matías, Luis; Jump, Alistair S

    2015-02-01

    Ongoing changes in global climate are altering ecological conditions for many species. The consequences of such changes are typically most evident at the edge of the geographical distribution of a species, where range expansions or contractions may occur. Current demographical status at geographical range limits can help us to predict population trends and their implications for the future distribution of the species. Thus, understanding the comparability of demographical patterns occurring along both altitudinal and latitudinal gradients would be highly informative. In this study, we analyse the differences in the demography of two woody species through altitudinal gradients at their southernmost distribution limit and the consistency of demographical patterns at the treeline across a latitudinal gradient covering the complete distribution range. We focus on Pinus sylvestris and Juniperus communis, assessing their demographical structure (density, age and mortality rate), growth, reproduction investment and damage from herbivory on 53 populations covering the upper, central and lower altitudes as well as the treeline at central latitude and northernmost and southernmost latitudinal distribution limits. For both species, populations at the lowermost altitude presented older age structure, higher mortality, decreased growth and lower reproduction when compared to the upper limit, indicating higher fitness at the treeline. This trend at the treeline was generally maintained through the latitudinal gradient, but with a decreased growth at the northern edge for both species and lower reproduction for P. sylvestris. However, altitudinal and latitudinal transects are not directly comparable as factors other than climate, including herbivore pressure or human management, must be taken into account if we are to understand how to infer latitudinal processes from altitudinal data. © 2014 John Wiley & Sons Ltd.

  3. Reproductive health of male radiographers

    International Nuclear Information System (INIS)

    Shakhatreh, Farouk M.

    2001-01-01

    To compare certain reproductive health problems reported in 2 groups of males, one of which was exposed to x-ray radiation (radiographers) and the other group that was not exposed to x-ray radiation. The reproductive health problems were miscarriage, congenital anomalies, still births and infertility. Two groups of men were selected (90 in each group). The first group consisted of radiographers and the other groups consisted of men not exposed to x-ray radiation. The 2 groups were matched for age and source. Relative risk, attributable risk percentage and level of significance were calculated. Incidence rate of reproductive health problems was increasing with the increase in duration of exposure to x-ray radiation ranging between 17% (for those exposed for 1-5 years) to 91% (for those exposed for more than 15 years). There were significant associations between exposure to radiation and miscarriage (relative risk = 1.67, attributable risk percentage = 40%), congenital anomalies (relative risk = 10, attributable risk percentage 90%), still birth (relative risk = 7, attributable risk percentage = 86%), and infertility (relative risk = 4.5, attributable risk = 78%). The incidence rates of reproductive health problems reported by male radiographers were significantly higher than that reported by the non exposed group and higher than the incidence rates reported in community-based studies in Jordan. The incidence rates of fetal death (miscarriage and stillbirth together) and infertility reported by our radiographers were higher than had been reported by the British radiographers. An immediate plan of action is needed to protect our radiographers. Further studies are needed in this field taking into account all extraneous variables that may affect the reproductive health of radiographers. (author)

  4. Preferences for Learning and Skill Development at Work: Comparison of Two Generations

    Directory of Open Access Journals (Sweden)

    Mariya Karaivanova

    2014-09-01

    Full Text Available The changing economic conditions of the current dynamic and insecure labour market make learning a constant preoccupation of the workforce with view of meeting the growing qualification demands. These demands are likely to influence the work preferences of both young people now entering the labour market and older people with established career paths. Research findings suggest that the younger generation exhibits a stronger orientation towards learning and skill development as compared to the older generations. Moreover, studies show that the younger people are more ready to leave the organization when they have better learning opportunities elsewhere. The present study aims at establishing how preferences for learning and skill development in the workplace relate to a number of job and organizational characteristics. Particular focus is placed on the predictive capacity of perceived learning opportunities towards the tendency to leave the organization for either of the two generations. The study addresses work preferences of two generations in the Bulgarian labour market. To this aim, 121 respondents answered a 55-item questionnaire consisting of newly developed scales as well as scales based on or adopted from standardized instruments such as the Extended Delft Measurement Kit (Roe et al., 2000. Contrary to findings from previous research done in countries with different cultural and socio-economic background, the older people in our sample were more eager to learn and more ready to leave their organization in pursuit of better opportunities, as compared to the younger generation. Another noteworthy conclusion is that the preferences for learning and development form different patterns in each of the two age groups and are expressed in a different way for each of the two generations.

  5. Influence of body condition on reproductive output in the guinea pig.

    Science.gov (United States)

    Michel, Catherine Louise; Bonnet, Xavier

    2012-01-01

    Reproduction is expensive. Substantial body reserves (i.e. high body condition) are usually required for females to undertake offspring production. In many vertebrates, maternal body condition positively influences reproductive output, and emaciated individuals skip reproduction. However, the impact of extremely high body condition, more specifically obesity, on animal reproductive performance remains poorly understood and research has generated contradictory results. For instance, obesity negatively affects fertility in women, but does not influence reproductive capacity or reproductive output in laboratory rodents. We examined the influence of high body condition on reproductive status and reproductive output in the guinea pig. In captivity, when fed ad libitum, guinea pigs store large amounts of fat tissues and exhibit a tendency for obesity. Our results show that obesity negatively affected reproduction in this species: both the proportion of fertile females and litter size were lower in the fattest females. Therefore, guinea pigs may represent suitable organisms to better understand the negative effect of obesity on reproduction. Copyright © 2011 Wiley Periodicals, Inc., A Wiley Company.

  6. Dominance, reproduction and survival in banded mongooses: towards an egalitarian social system?

    Science.gov (United States)

    de Luca, D. W.; Ginsberg, J. R.

    2001-01-01

    The banded mongoose, Mungos mungo, is a social species that forms multimale and multifemale family groups. Earlier studies suggest these family groups are relatively egalitarian with small differences in reproductive opportunities among individuals of different rank. In contrast, previous studies of other social mongooses have focused on species with more despotic control of reproduction (meerkats, Suricata suricatta, dwarf mongooses, Helogale parvula). In these species, the distribution of reproductive opportunities amongst individuals of different rank has met the predictions of reproductive skew theory: dominant individuals accrue greater reproductive benefits than subordinates, with subordinates breeding less often than dominants. In this paper we test how well two predictions of reproductive skew theory explain variance in measures of reproductive effort, and its correlates, in a wild population of banded mongooses in Queen Elizabeth National Park, Uganda. We measure dominance rank in males and females, and we investigate whether individuals of higher social rank accrue greater benefits than subordinates in terms of survival and reproduction. Banded mongoose dominance hierarchies showed linearity, but low reproductive skew. Rank was not significantly correlated with age. Furthermore, there were only small effects of dominance rank on nutritional levels, and no effects on reproduction and survival, suggesting that banded mongoose societies are indeed relatively egalitarian. No evidence of reproductive suppression was found and other forms of reproductive control were not observed. However, we do not exclude the possibility of increased reproductive competition in circumstances of higher ecological constraints. These findings show that reproductive skew theory is equally useful in explaining variation in reproduction in societies with low reproductive skew, as it is in explaining the allocation of reproductive effort in despotic social systems. Copyright 2001

  7. Herbs of interest to the Brazilian Federal Government: female reproductive and developmental toxicity studies

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Verissimo

    2011-12-01

    Full Text Available In 2009 the Brazilian Ministry of Health published a document named RENISUS that lists 71 herbs traditionally used in Brazil that could result in phytomedicines to be dispensed by the governmental health care program. This manuscript reviews female reproductive and/or developmental toxicity information of these herbs. More than half (35 of the herbs lack information regarding female reproductive and/or developmental effects. From the fourteen herbs used traditionally to disturb female reproduction, five present experimental data corroborating their actions as abortifacients (Maytenus ilicifolia, Momordica charantia, Plectranthus barbatus, Ruta graveolens or labour facilitator (Bidens pilosa. For 23 of the herbs evaluated experimentally for any type of female reproductive endpoint, only a single study was retrieved and at least twelve of these studies were conducted with a single dose. This scenario suggests that the scientific power of the published information is very low and that a scientifically-based risk/benefit analysis about the use of these herbs during pregnancy is not possible. Considering the appeal that phytomedicines have for pregnant women, usually aware and afraid of the risks that synthetic drugs may have in their pregnancy and progeny, well designed studies evaluating reproductive and/or developmental toxicity of these herbs urge.

  8. Herbs of interest to the Brazilian Federal Government: female reproductive and developmental toxicity studies

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Verissimo

    2011-08-01

    Full Text Available In 2009 the Brazilian Ministry of Health published a document named RENISUS that lists 71 herbs traditionally used in Brazil that could result in phytomedicines to be dispensed by the governmental health care program. This manuscript reviews female reproductive and/or developmental toxicity information of these herbs. More than half (35 of the herbs lack information regarding female reproductive and/or developmental effects. From the fourteen herbs used traditionally to disturb female reproduction, five present experimental data corroborating their actions as abortifacients (Maytenus ilicifolia, Momordica charantia, Plectranthus barbatus, Ruta graveolens or labour facilitator (Bidens pilosa. For 23 of the herbs evaluated experimentally for any type of female reproductive endpoint, only a single study was retrieved and at least twelve of these studies were conducted with a single dose. This scenario suggests that the scientific power of the published information is very low and that a scientifically-based risk/benefit analysis about the use of these herbs during pregnancy is not possible. Considering the appeal that phytomedicines have for pregnant women, usually aware and afraid of the risks that synthetic drugs may have in their pregnancy and progeny, well designed studies evaluating reproductive and/or developmental toxicity of these herbs urge.

  9. Islam, Assisted Reproduction, and the Bioethical Aftermath.

    Science.gov (United States)

    Inhorn, Marcia C; Tremayne, Soraya

    2016-04-01

    Assisted reproductive technologies (ARTs), including in vitro fertilization to overcome infertility, are now widely available across the Middle East. Islamic fatwas emerging from the Sunni Islamic countries have permitted many ARTs, while prohibiting others. However, recent religious rulings emanating from Shia Muslim-dominant Iran have created unique avenues for infertile Muslim couples to obtain donor gametes through third-party reproductive assistance. The opening of Iran to gamete donation has had major impacts in Shia-dominant Lebanon and has led to so-called reproductive tourism of Sunni Muslim couples who are searching for donor gametes across national and international borders. This paper explores the "bioethical aftermath" of donor technologies in the Muslim Middle East. Other unexpected outcomes include new forms of sex selection and fetal "reduction." In general, assisted reproduction in the Muslim world has been a key site for understanding how emerging biomedical technologies are generating new Islamic bioethical discourses and local moral responses, as ARTs are used in novel and unexpected ways.

  10. Latitudinal variation in the reproductive cycle of two bivalves with contrasting biogeographical origin along the Humboldt Current Upwelling Ecosystem

    Directory of Open Access Journals (Sweden)

    Roberto A. Uribe

    2012-10-01

    Full Text Available Argopecten purpuratus (Lamarck, 1819 and Mesodesma donacium (Lamarck, 1818 are bivalves that inhabit the Humboldt Current Upwelling Ecosystem. They have contrasting biogeographical origins, suggesting that their responses to exogenous factors should differ. Using circular statistics, we examine synchrony/asynchrony in the reproductive cycle between populations of each species. The results indicate that there is reproductive asynchrony in both species along their distributional range. However, there was synchrony for A. purpuratus in several location-pairs, including Paita-Chimbote, Chimbote-Callao, Callao-Pisco and Pisco-Antofagasta. For M. donacium, there were only two synchronic groups: Camaná-Capellanía-Mehuín and Hornitos-Peñuelas-Longotoma-La Ligua-Cucao-Quilanlar. A. purpuratus showed gametogenenic activity throughout the year. In contrast, M. donacium showed strong seasonality, with gametogenesis in winter and spawning in spring/summer. In conclusion, the patterns observed for these sympatric species suggest that on a large scale the reproductive cycles follow the expected patterns for the contrasting biogeographic origin of each species, so it could be argued that they are modulated by endogenous factors. However, at a local scale, the reproductive cycles of these species show variation, likely determined by local oceanographic or hydrographic processes.

  11. The use of reproductive vigor descriptors in studying genetic ...

    African Journals Online (AJOL)

    The use of reproductive vigor descriptors in studying genetic variability in nine Tunisian faba bean ( Vicia faba L.) populations. ... The dendrogram based on Nei's genetic distance of the 9 populations using UPGMA method, show some genetic drift between populations. Key words: Faba bean, agromorphological traits, ...

  12. Comparative study of reproductive tract infections of female sex ...

    African Journals Online (AJOL)

    Background: Reproductive tract infections (RTIs) have become international public health problem. Aim: We assessed the RTIs. A community-based study was carried out among female sex workers (FSWs), gynecology clinic patients and general population in Suzhou, China to investigate the major pathogens of RTIs and ...

  13. Theoretical study of the generation of terahertz radiation by the interaction of two laser beams with graphite nanoparticles

    Science.gov (United States)

    Sepehri Javan, N.; Rouhi Erdi, F.

    2017-12-01

    In this theoretical study, we investigate the generation of terahertz radiation by considering the beating of two similar Gaussian laser beams with different frequencies of ω1 and ω2 in a spatially modulated medium of graphite nanoparticles. The medium is assumed to contain spherical graphite nanoparticles of two different configurations: in the first configuration, the electric fields of the laser beams are parallel to the normal vector of the basal plane of the graphite structure, whereas in the second configuration, the electric fields are perpendicular to the normal vector of the basal plane. The interaction of the electric fields of lasers with the electronic clouds of the nanoparticles generates a ponderomotive force that in turn leads to the creation of a macroscopic electron current in the direction of laser polarizations and at the beat frequency ω1-ω2 , which can generate terahertz radiation. We show that, when the beat frequency lies near the effective plasmon frequency of the nanoparticles and the electric fields are parallel to the basal-plane normal, a resonant interaction of the laser beams causes intense terahertz radiation.

  14. Reproductive studies with the anti-inflammatory agent, piroxicam: modification of classical protocols.

    Science.gov (United States)

    Perraud, J; Stadler, J; Kessedjian, M J; Monro, A M

    1984-02-14

    Reproductive toxicology studies were conducted in rabbits and rats given piroxicam, a non-steroidal anti-inflammatory agent (NSAI), orally at 2, 5 and 10 mg/kg/day. In teratology studies there was neither drug-related embryotoxicity nor teratogenicity. As piroxicam, like other NSAI, affects parturition in rats and leads to a progressive toxicity in lactating females, standard protocols were modified: dams of the female fertility study were treated from 2 weeks prior to mating until day 6 of gestation and females of the post-natal toxicity study were treated from parturition until day 12 of lactation. No other adverse effects on reproduction, fertility and postnatal development were observed.

  15. The roles of sexual and asexual reproduction in the origin and dissemination of strains causing fungal infectious disease outbreaks.

    Science.gov (United States)

    Ashu, Eta Ebasi; Xu, Jianping

    2015-12-01

    Sexual reproduction commonly refers to the reproductive process in which genomes from two sources are combined into a single cell through mating and then the zygote genomes are partitioned to progeny cells through meiosis. Reproduction in the absence of mating and meiosis is referred to as asexual or clonal reproduction. One major advantage of sexual reproduction is that it generates genetic variation among progeny which may allow for faster adaptation of the population to novel and/or stressful environments. However, adaptation to stressful or new environments can still occur through mutation, in the absence of sex. In this review, we analyzed the relative contributions of sexual and asexual reproduction in the origin and spread of strains causing fungal infectious diseases outbreaks. The necessity of sex and the ability of asexual fungi to initiate outbreaks are discussed. We propose a framework that relates the modes of reproduction to the origin and propagation of fungal disease outbreaks. Our analyses suggest that both sexual and asexual reproduction can play critical roles in the origin of outbreak strains and that the rapid spread of outbreak strains is often accomplished through asexual expansion. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Workflow Generation from the Two-Hemisphere Model

    Directory of Open Access Journals (Sweden)

    Gusarovs Konstantīns

    2017-12-01

    Full Text Available Model-Driven Software Development (MDSD is a trend in Software Development that focuses on code generation from various kinds of models. To perform such a task, it is necessary to develop an algorithm that performs source model transformation into the target model, which ideally is an actual software code written in some kind of a programming language. However, at present a lot of methods focus on Unified Modelling Language (UML diagram generation. The present paper describes a result of authors’ research on Two-Hemisphere Model (2HM processing for easier code generation.

  17. Do native brown trout and non-native brook trout interact reproductively?

    Science.gov (United States)

    Cucherousset, J.; Aymes, J. C.; Poulet, N.; Santoul, F.; Céréghino, R.

    2008-07-01

    Reproductive interactions between native and non-native species of fish have received little attention compared to other types of interactions such as predation or competition for food and habitat. We studied the reproductive interactions between non-native brook trout ( Salvelinus fontinalis) and native brown trout ( Salmo trutta) in a Pyrenees Mountain stream (SW France). We found evidence of significant interspecific interactions owing to consistent spatial and temporal overlap in redd localizations and spawning periods. We observed mixed spawning groups composed of the two species, interspecific subordinate males, and presence of natural hybrids (tiger trout). These reproductive interactions could be detrimental to the reproduction success of both species. Our study shows that non-native species might have detrimental effects on native species via subtle hybridization behavior.

  18. Factors affecting the reproductive traits of Holstein cows

    Directory of Open Access Journals (Sweden)

    Daniella Flavia Vilas Boas

    2012-12-01

    Full Text Available For dairy cattle breeds, mainly the taurine ones, the selection emphasized for many years the increase in milk yields and, as a consequence, the adaptive and reproductive traits were negatively affected. The aim of this study was to verify the influence of genetic and environmental effects on the reproductive traits in a dairy herd selected for high milk production levels. The data set comprised 1,737 first lactations Holsteins cows of Agrindus Farm, located at Southeastern region of Brazil. The records of the following reproductive traits: calving to first heat interval (CFHI, calving to conception interval (CCI and first to second calving interval (FCI were analyzed as dependent variables by least squares method using GLM procedure (SAS. Linear models were considered including two production levels (1= less than 9,500 kg and 2= more than 9,501 kg of total milk yield, contemporary group (year and months calving, management group, sire of cow, and the sire used to breeding cows, as classificatory variables. As covariates were included for all traits the peak milk yield in lactation (linear effect, age at calving only for CFHI (linear and quadratic effects since this effect was not significant for other traits, and CFHI (linear effect only for FCI. The coefficients of determination represented 24%, 74% and 75%, respectively for CFHI, FCI and CCI models. Production level, peak milk yield and sire effects were significant (P<0.05 for all traits. The average estimated for high and low milk production level were 73 and 79 days, 500 and 601 days, 227 and 330 days for CFHI, FCI and CCI, respectively, suggesting that cows with higher genetic potential for milk had worse reproductive performance. Similarly, lactation peak showed significant effect (P<0.05 for all traits, suggesting higher peaks cows showed also poorer reproductive rates. Sire effect also was a variable that showed significant effect (P<0.01 for all traits, which means that there was

  19. Visual monitoring of reproduction in dairy herds

    DEFF Research Database (Denmark)

    Thysen, Iver; Enevoldsen, Carsten

    1994-01-01

    Two complementary approaches to produce visual information from reproduction records are described and exemplified. The Event Display shows all reproductive events, over a year, for all cows in a herd, by symbols placed in an array with columns representing calendar weeks and rows representing...... individual cows. The Reproduction Monitor consists of graphs of insemination and pregnancy rates evaluated weekly with a Bayesian technique. These visual monitoring tools are well suited to explore temporal variation in reproductive performance, they provide a quick overview of herd performance...

  20. Barriers to male involvement in contraceptive uptake and reproductive health services: a qualitative study of men and women's perceptions in two rural districts in Uganda.

    Science.gov (United States)

    Kabagenyi, Allen; Jennings, Larissa; Reid, Alice; Nalwadda, Gorette; Ntozi, James; Atuyambe, Lynn

    2014-03-05

    Spousal communication can improve family planning use and continuation. Yet, in countries with high fertility rates and unmet need, men have often been regarded as unsupportive of their partner's use of family planning methods. This study examines men and women's perceptions regarding obstacles to men's support and uptake of modern contraceptives. A qualitative study using 18 focus group discussions (FGDs) with purposively selected men aged 15-54 and women aged 15-49 as well as eight key informant interviews (KIIs) with government and community leaders was conducted in 2012 in Bugiri and Mpigi Districts, Uganda. Open-ended question guides were used to explore men and women's perceptions regarding barriers to men's involvement in reproductive health. All FGDs and KIIs were recorded, translated, and transcribed verbatim. Transcripts were coded and analyzed thematically using ATLAS.ti. Five themes were identified as rationale for men's limited involvement: (i) perceived side effects of female contraceptive methods which disrupt sexual activity, (ii) limited choices of available male contraceptives, including fear and concerns relating to vasectomy, (iii) perceptions that reproductive health was a woman's domain due to gender norms and traditional family planning communication geared towards women, (iv) preference for large family sizes which are uninhibited by prolonged birth spacing; and (v) concerns that women's use of contraceptives will lead to extramarital sexual relations. In general, knowledge of effective contraceptive methods was high. However, lack of time and overall limited awareness regarding the specific role of men in reproductive health was also thought to deter men's meaningful involvement in issues related to fertility regulation. Decision-making on contraceptive use is the shared responsibility of men and women. Effective development and implementation of male-involvement family planning initiatives should address barriers to men's supportive

  1. Salmonid Reproductive Migration and Effects on Sexual Maturation

    NARCIS (Netherlands)

    Hayashida, K.; Fukaya, K.; Palstra, A.P.; Ueda, H.

    2013-01-01

    Salmon has amazing abilities to migrate long distances from the ocean to their natal streams for reproduction. Reproductive homing migration was investigated by two different research approaches from behavioural biology to endocrinology using chum salmon in the north Pacific Ocean as well as two

  2. Wildlife conservation and reproductive cloning.

    Science.gov (United States)

    Holt, William V; Pickard, Amanda R; Prather, Randall S

    2004-03-01

    Reproductive cloning, or the production of offspring by nuclear transfer, is often regarded as having potential for conserving endangered species of wildlife. Currently, however, low success rates for reproductive cloning limit the practical application of this technique to experimental use and proof of principle investigations. In this review, we consider how cloning may contribute to wildlife conservation strategies. The cloning of endangered mammals presents practical problems, many of which stem from the paucity of knowledge about their basic reproductive biology. However, situations may arise where resources could be targeted at recovering lost or under-represented genetic lines; these could then contribute to the future fitness of the population. Approaches of this type would be preferable to the indiscriminate generation of large numbers of identical individuals. Applying cloning technology to non-mammalian vertebrates may be more practical than attempting to use conventional reproductive technologies. As the scientific background to cloning technology was pioneered using amphibians, it may be possible to breed imminently threatened amphibians, or even restore extinct amphibian species, by the use of cloning. In this respect species with external embryonic development may have an advantage over mammals as developmental abnormalities associated with inappropriate embryonic reprogramming would not be relevant.

  3. Two Integrator Loop Filters: Generation Using NAM Expansion and Review

    Directory of Open Access Journals (Sweden)

    Ahmed M. Soliman

    2010-01-01

    Full Text Available Systematic synthesis method to generate a family of two integrator loop filters based on nodal admittance matrix (NAM expansion is given. Eight equivalent circuits are obtained; six of them are new. Each of the generated circuits uses two grounded capacitors and employs two current conveyors (CCII or two inverting current conveyors (ICCII or a combination of both. The NAM expansion is also used to generate eight equivalent grounded passive elements two integrator loop filters using differential voltage current conveyor (DVCC; six of them are new. Changing the input port of excitation, two new families of eight unity gain lowpass filter circuits each using two CCII or ICCII or combination of both or two DVCC are obtained.

  4. Study efficacy of new model of derivative clonazepam on hypnotic, sedative, blood hematology and evaluation reproductive function in male mice

    OpenAIRE

    Adnan M. Jassim; Abbas G. Hamad; Mohammed Abed; Raad Saad

    2016-01-01

    Objectives This study includes the investigation of hypnotic and sedative effect of new generation agent synthesis from parent clonazepam and evaluates adverse effect on the reproductive system and an attempt to improve hypnotic effect and lower toxicity. Methods Sixteen male mice were randomly divided into four groups. The first day of treatment with single dose of 50 mg/kg intraperitoneal (IP) hypnotic effect then analgesic state was recorded in the 4th day of first week only after given...

  5. Unisexual reproduction in Huntiella moniliformis.

    Science.gov (United States)

    Wilson, A M; Godlonton, T; van der Nest, M A; Wilken, P M; Wingfield, M J; Wingfield, B D

    2015-07-01

    Sexual reproduction in fungi is controlled by genes present at the mating type (MAT) locus, which typically harbors transcription factors that influence the expression of many sex-related genes. The MAT locus exists as two alternative idiomorphs in ascomycetous fungi and sexual reproduction is initiated when genes from both idiomorphs are expressed. Thus, the gene content of this locus determines whether a fungus is heterothallic (self-sterile) or homothallic (self-fertile). Recently, a unique sub-class of homothallism has been described in fungi, where individuals possessing a single MAT idiomorph can reproduce sexually in the absence of a partner. Using various mycological, molecular and bioinformatic techniques, we investigated the sexual strategies and characterized the MAT loci in two tree wound-infecting fungi, Huntiella moniliformis and Huntiella omanensis. H. omanensis was shown to exhibit a typically heterothallic sexual reproductive cycle, with isolates possessing either the MAT1-1 or MAT1-2 idiomorph. This was in contrast to the homothallism via unisexual reproduction that was shown in H. moniliformis, where only the MAT1-2-1 gene was present in sexually reproducing cultures. While the evolutionary benefit and mechanisms underpinning a unisexual mating strategy remain unknown, it could have evolved to minimize the costs, while retaining the benefits, of normal sexual reproduction. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Identification of hemiclonal reproduction in three species of Hexagrammos marine reef fishes.

    Science.gov (United States)

    Kimura-Kawaguchi, M R; Horita, M; Abe, S; Arai, K; Kawata, M; Munehara, H

    2014-08-01

    Natural hybrids between the boreal species Hexagrammos octogrammus and two temperate species Hexagrammos agrammus and Hexagrammos otakii were observed frequently in southern Hokkaido, Japan. Previous studies revealed that H. octogrammus is a maternal ancestor of both hybrids; the hybrids are all fertile females and they frequently breed with paternal species. Although such rampant hybridization occurs, species boundaries have been maintained in the hybrid zone. Possible explanations for the absence of introgressions, despite the frequent backcrossing, might include clonal reproduction: parthenogenesis, gynogenesis and hybridogenesis. The natural hybrids produced haploid eggs that contained only the H. octogrammus genome (maternal ancestor) with discarded paternal genome and generated F1 -hybrid type offspring by fertilization with the haploid sperm of H. agrammus or H. otakii (paternal ancestor). This reproductive mode was found in an artificial backcross hybrid between the natural hybrid and a male of the paternal ancestor. These findings indicate that the natural hybrids adopt hybridogenesis with high possibility and produce successive generations through hybridogenesis by backcrossing with the paternal ancestor. These hybrids of Hexagrammos represent the first hybridogenetic system found from marine fishes that widely inhabit the North Pacific Ocean. In contrast with other hybridogenetic systems, these Hexagrammos hybrids coexist with all three ancestral species in the hybrid zone. The coexistence mechanism is also discussed. © 2014 The Fisheries Society of the British Isles.

  7. Characterizing the reproduction number of epidemics with early subexponential growth dynamics.

    Science.gov (United States)

    Chowell, Gerardo; Viboud, Cécile; Simonsen, Lone; Moghadas, Seyed M

    2016-10-01

    Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number generally assume exponential growth in case incidence in the first few disease generations, before susceptible depletion sets in. In reality, outbreaks can display subexponential (i.e. polynomial) growth in the first few disease generations, owing to clustering in contact patterns, spatial effects, inhomogeneous mixing, reactive behaviour changes or other mechanisms. Here, we introduce the generalized growth model to characterize the early growth profile of outbreaks and estimate the effective reproduction number, with no need for explicit assumptions about the shape of epidemic growth. We demonstrate this phenomenological approach using analytical results and simulations from mechanistic models, and provide validation against a range of empirical disease datasets. Our results suggest that subexponential growth in the early phase of an epidemic is the rule rather the exception. Mechanistic simulations show that slight modifications to the classical susceptible-infectious-removed model result in subexponential growth, and in turn a rapid decline in the reproduction number within three to five disease generations. For empirical outbreaks, the generalized-growth model consistently outperforms the exponential model for a variety of directly and indirectly transmitted diseases datasets (pandemic influenza, measles, smallpox, bubonic plague, cholera, foot-and-mouth disease, HIV/AIDS and Ebola) with model estimates supporting subexponential growth dynamics. The rapid decline in effective reproduction number predicted by analytical results and observed in real and synthetic datasets within three to five disease generations contrasts with the expectation of invariant reproduction number in epidemics obeying exponential growth. The

  8. Characterizing the reproduction number of epidemics with early subexponential growth dynamics

    Science.gov (United States)

    Viboud, Cécile; Simonsen, Lone; Moghadas, Seyed M.

    2016-01-01

    Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number generally assume exponential growth in case incidence in the first few disease generations, before susceptible depletion sets in. In reality, outbreaks can display subexponential (i.e. polynomial) growth in the first few disease generations, owing to clustering in contact patterns, spatial effects, inhomogeneous mixing, reactive behaviour changes or other mechanisms. Here, we introduce the generalized growth model to characterize the early growth profile of outbreaks and estimate the effective reproduction number, with no need for explicit assumptions about the shape of epidemic growth. We demonstrate this phenomenological approach using analytical results and simulations from mechanistic models, and provide validation against a range of empirical disease datasets. Our results suggest that subexponential growth in the early phase of an epidemic is the rule rather the exception. Mechanistic simulations show that slight modifications to the classical susceptible–infectious–removed model result in subexponential growth, and in turn a rapid decline in the reproduction number within three to five disease generations. For empirical outbreaks, the generalized-growth model consistently outperforms the exponential model for a variety of directly and indirectly transmitted diseases datasets (pandemic influenza, measles, smallpox, bubonic plague, cholera, foot-and-mouth disease, HIV/AIDS and Ebola) with model estimates supporting subexponential growth dynamics. The rapid decline in effective reproduction number predicted by analytical results and observed in real and synthetic datasets within three to five disease generations contrasts with the expectation of invariant reproduction number in epidemics obeying exponential growth. The

  9. Induced Abortion and Women’s Reproductive Health in India

    Directory of Open Access Journals (Sweden)

    Sutapa Agrawal

    2013-08-01

    Full Text Available Despite the intensive national campaign for safe motherhood and legalization of induced abortion (IA, morbidity from abortion has remained a serious problem for Indian women. This study examined the consequences of IA on women’s reproductive health. Analysis used data of 90,303 ever-married women age 15-49 years, included in India’s second National Family Health Survey (NFHS-2, 1998-99. Binary logistic regression methods were used to examine the consequences of IA on women’s reproductive health. Independent of other factors, the likelihood of experiencing any reproductive health problems was 1.5 times higher (OR,1.46;95%CI,1.33-1.60;P<0.001 among women who had one IA and 1.9 times higher (OR,1.85;95%CI,1.52-2.27;P<0.001 among women who had two or more IA compared to women with no history of IA. Study suggests that IA may have negative consequences for women’s reproductive health.

  10. Induced Abortion and Women’s Reproductive Health in India

    Directory of Open Access Journals (Sweden)

    Sutapa Agrawal

    2013-01-01

    Full Text Available Despite the intensive national campaign for safe motherhood and legalization of induced abortion (IA, morbidity from abortion has remained a serious problem for Indian women. This study examined the consequences of IA on women’s reproductive health. Analysis used data of 90,303 ever-married women age 15-49 years, included in India’s second National Family Health Survey (NFHS-2, 1998-99. Binary logistic regression methods were used to examine the consequences of IA on women’s reproductive health. Independent of other factors, the likelihood of experiencing any reproductive health problems was 1.5 times higher (OR,1.46;95%CI,1.33-1.60;P<0.001 among women who had one IA and 1.9 times higher (OR,1.85;95%CI,1.52-2.27;P<0.001 among women who had two or more IA compared to women with no history of IA. Study suggests that IA may have negative consequences for women’s reproductive health.

  11. Does temperature-mediated reproductive success drive the direction of species displacement in two invasive species of leafminer fly?

    Directory of Open Access Journals (Sweden)

    Haihong Wang

    Full Text Available Liriomyza sativae and L. trifolii (Diptera: Agromyzidae are two highly invasive species of leafmining flies, which have become established as pests of horticultural crops throughout the world. In certain regions where both species have been introduced, L. sativae has displaced L. trifolii, whereas the opposite has occurred in other regions. These opposing outcomes suggest that neither species is an inherently superior competitor. The regions where these displacements have been observed (southern China, Japan and western USA are climatically different. We determined whether temperature differentially affects the reproductive success of these species and therefore if climatic differences could affect the outcome of interspecific interactions where these species are sympatric. The results of life table parameters indicate that both species can develop successfully at all tested temperatures (20, 25, 31, 33°C. L. sativae had consistently higher fecundities at all temperatures, but L. trifolii developed to reproductive age faster. Age-stage specific survival rates were higher for L. sativae at low temperatures, but these were higher for L. trifolii at higher temperatures. We then compared the net reproductive rates (R0 for both species in pure and mixed cultures maintained at the same four constant temperatures. Both species had significantly lower net reproductive rates in mixed species cultures compared with their respective pure species cultures, indicating that both species are subject to intense interspecific competition. Net reproductive rates were significantly greater for L. sativae than for L. trifolii in mixed species groups at the lower temperatures, whereas the opposite occurred at the higher temperature. Therefore, interactions between the species are temperature dependent and small differences could shift the competitive balance between the species. These temperature mediated effects may contribute to the current ongoing displacement

  12. Perceived stress, reproductive hormones, and ovulatory function: a prospective cohort study

    Science.gov (United States)

    Schliep, Karen C.; Mumford, Sunni L.; Vladutiu, Catherine J.; Ahrens, Katherine A.; Perkins, Neil J.; Sjaarda, Lindsey A.; Kissell, Kerri A.; Prasad, Ankita; Wactawski-Wende, Jean; Schisterman, Enrique F.

    2014-01-01

    Background Stress has been shown to suppress ovulation in experimental models, but its effect on human reproduction at the population level is unclear. Methods Healthy women (n=259), aged 18–44 years from Western New York, were followed for two menstrual cycles (2005–2007). Women completed daily perceived stress assessments, a 4-item Perceived Stress Scale (PSS-4) up to four times each cycle, and a 14-item PSS at baseline. Mixed model analyses were used to assess effects of stress on log reproductive hormone concentrations and sporadic anovulation. Results High versus low daily stress was associated with lower estradiol (-9.5%; 95% confidence interval (CI)= -15.6% to -3.0%), free estradiol (-10.4% [-16.5% to -3.9%]), and LH (-14.8% = [-21.3% to -7.7%]), and higher FSH (6.2% [2.0% to 10.5%]) after adjusting for age, race, percent body fat, depression score, and time-varying hormones and vigorous exercise. High versus low daily stress was also associated with lower luteal progesterone (-10.4% [-19.7% to -0.10%]) and higher odds of anovulation (adjusted OR = 2.2 [95% CI=1.0 to 4.7]). For each unit increase in daily stress level, women had a 70% higher odds of an anovulatory episode (OR=1.7 [1.1 to 2.4]). Similar but attenuated results were found for the association between the PSS-4 and reproductive hormones, while null findings were found for the baseline PSS. Conclusion Daily perceived stress does appear to interfere with menstrual cycle function among women with no known reproductive disorders, warranting further research to explore potential population-level impacts and causal biologic mechanisms. PMID:25643098

  13. Reversible, on-demand generation of aqueous two-phase microdroplets

    Science.gov (United States)

    Collier, Charles Patrick; Retterer, Scott Thomas; Boreyko, Jonathan Barton; Mruetusatorn, Prachya

    2017-08-15

    The present invention provides methods of on-demand, reversible generation of aqueous two-phase microdroplets core-shell microbeads, microparticle preparations comprising the core-shell microbeads, and drug delivery formulation comprising the microparticle preparations. Because these aqueous microdroplets have volumes comparable to those of cells, they provide an approach to mimicking the dynamic microcompartmentation of biomaterial that naturally occurs within the cytoplasm of cells. Hence, the present methods generate femtoliter aqueous two-phase droplets within a microfluidic oil channel using gated pressure pulses to generate individual, stationary two-phase microdroplets with a well-defined time zero for carrying out controlled and sequential phase transformations over time. Reversible phase transitions between single-phase, two-phase, and core-shell microbead states are obtained via evaporation-induced dehydration and water rehydration.

  14. Comparing the Reproductive Success of Yakima River Hatchery- and Wild-Origin Spring Chinook; Yakima/Klickitat Fisheries Project Monitoring and Evaluation, 2005-2006 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Schroder, S.L.; Pearsons, T.N. (Washington Department of Fish and Wildlife, Olympia, WA); Knudsen, C.M. (Oncorh Consulting, Olympia, WA)

    2006-05-01

    Reproductive success in wild- and first generation hatchery-origin spring Chinook males was examined by allowing the fish to compete for spawning opportunities in two sections of an observation stream. Behavioral observations were used to characterize the frequency of aggression and courting activities. Microsatellite DNA from each male and fry collected from the observation stream were used in pedigree analyses to estimate reproductive success. The coefficient of variation in male reproductive success equaled 116 and 86% in the two populations. No differences were detected in reproductive success due to hatchery or wild origin. Nor were any behavioral differences found between hatchery and wild males. Although statistical power was low due to intrinsic variation a great deal of overlap existed in the reproductive success values of hatchery and wild males. Significant disparities existed among the males on their ability to produce offspring. Males achieving high reproductive success mated with numerous females, were socially dominant, aggressive, and tended to stay in localized areas, courting and spawning with females that were adjacent to one another.

  15. Impacts of selective logging on inbreeding and gene flow in two Amazonian timber species with contrasting ecological and reproductive characteristics.

    Science.gov (United States)

    Vinson, C C; Kanashiro, M; Harris, S A; Boshier, D H

    2015-01-01

    Selective logging in Brazil allows for the removal of up to 90% of trees above 50 cm diameter of a given timber species, independent of a species' life history characteristics or how quickly it will recover. The genetic and demographic effects of selective logging on two Amazonian timber species (Dipteryx odorata Leguminosae, Jacaranda copaia Bignoniaceae) with contrasting ecological and reproductive characteristics were assessed in the same forest. Genetic diversity and gene flow were characterized by genotyping adults and seed sampled before and after logging, using hypervariable microsatellite markers. Overall, there were no short-term genetic impacts on the J. copaia population, with commercial application of current Brazilian forest management regulations. In contrast, for D. Odorata, selective logging showed a range of genetic impacts, with a 10% loss of alleles, and reductions in siring by pollen from trees within the 546-ha study area (23-11%) and in the number of pollen donors per progeny array (2.8-1.6), illustrating the importance of the surrounding landscape. Asynchrony in flowering between D. odorata trees led to trees with no breeding partners, which could limit the species reproduction and regeneration under current regulations. The results are summarized with other published studies from the same site and the implications for forest management discussed. The different types and levels of impacts associated with each species support the idea that ecological and genetic information by species, ecological guild or reproductive group is essential in helping to derive sustainable logging guidelines for tropical forests. © 2014 John Wiley & Sons Ltd.

  16. Reproductive Interference and Niche Partitioning in Aphidophagous Insects

    Directory of Open Access Journals (Sweden)

    Suzuki Noriyuki

    2016-01-01

    Full Text Available The range and quality of prey species differ greatly among closely related species of predators. However, the factors responsible for this diversified niche utilization are unclear. This is because the predation and resource competition do not always prevent species coexistence. In this paper, we present evidence in support of reproductive interference as a driver of niche partitioning, focusing on aphidophagous insect. Firstly, we present closely related generalist and specialist species pairs in aphidophagous lacewings to compare the reproductive interference hypothesis with two other hypotheses that have been proposed to explain niche partitioning in lacewings and sympatric speciation through host race formation and sexual selection. Secondly, we present a case study that shows how reproductive interference can drive niche partitioning in sibling ladybird species. Thirdly, we show that many ladybird genera include species inhabiting the same region but having different food and habitat preferences, raising the possibility that reproductive interference might occur in these groups. Finally, we show that intraguild predation cannot always explain the niche partitioning in aphidophagous insects including hoverflies and parasitoids. On the basis of the evidence presented, we urge that future studies investigating predator communities should take account of the role of reproductive interference.

  17. Health Literacy and Women's Reproductive Health: A Systematic Review

    Science.gov (United States)

    Vitko, Michelle; O'Conor, Rachel; Bailey, Stacy Cooper

    2016-01-01

    Abstract Background: Health literacy is thought to impact women's reproductive health, yet no comprehensive systematic reviews have been conducted on the topic. Our objective was to systematically identify, investigate, and summarize research on the relationship between health literacy and women's reproductive health knowledge, behaviors, and outcomes. Methods: PRISMA guidelines were used to guide this review. English language, peer-reviewed research articles indexed in MEDLINE as of February 2015 were searched, along with study results posted on Clinicaltrials.gov. Articles were included if they (1) described original data-driven research conducted in developed countries, (2) were published in a peer-reviewed journal, (3) measured health literacy using a validated assessment, (4) reported on the relationship between health literacy and reproductive health outcomes, related knowledge, or behaviors, and (5) consisted of a study population that included reproductive age women. Results: A total of 34 articles met eligibility criteria and were included in this review. Data were abstracted from articles by two study authors using a standardized form. Abstracted data were then reviewed and summarized in table format. Overall, health literacy was associated with reproductive health knowledge across a spectrum of topics. It was also related to certain health behaviors, such as prenatal vitamin use and breastfeeding. Its relationship with other reproductive behaviors and outcomes remains unclear. Conclusions: Health literacy plays an important role in reproductive knowledge and may impact behaviors and outcomes. While further research is necessary, healthcare providers should utilize health literacy best practices now to promote high-quality care for patients. PMID:27564780

  18. Prenatal testosterone exposure worsen the reproductive performance of male rat at adulthood.

    Science.gov (United States)

    Ramezani Tehrani, Fahimeh; Noroozzadeh, Mahsa; Zahediasl, Saleh; Ghasemi, Asghar; Piryaei, Abbas; Azizi, Fereidoun

    2013-01-01

    The reproductive system is extremely susceptible to environmental insults, for example exogenous steroids during gestational development and differentiation. Experimental induction of androgen excess during prenatal life in female animal models reprograms their reproductive physiology, however the fetal programming of the male reproductive system by androgen excess has not been well studied. We aimed to determine the effect of prenatal exposure of two different doses of testosterone on different gestational days, on the male reproductive system using a rat model. Sixteen pregnant rats were randomly divided into two experimental groups and two control groups. Experimental group І were subcutaneously injected with 3 mg free testosterone on gestational days 16-19 and its controls received solvent for that time; experimental group П were subcutaneously injected with 20 mg free testosterone on day 20 of gestational period and its controls received solvent at the same time. The reproductive system morphology and function of 32 male offspring of these study groups were compared at days 6-30-60 of age and after puberty. The anogenital distance of the male offspring of both experimental groups had no significant differences on the different days of measurement, compared with controls. In the offspring of experimental group І, the testes weight, number of Sertoli, Spermatocyte and Spermatid cells, sperm count and motility and the serum concentration of testosterone after puberty were significantly decreased; except for reduction of sperm motility (pmale rat fetuses to excess testosterone disrupted reproductive function, an effect highly dependent on the time, duration and level of exposure. It seems that the reproductive system in individuals exposed to high levels of androgens during fetal life should be evaluated at puberty and likely to be treated.

  19. Experimental evidence of population differences in reproductive investment conditional on environmental stochasticity

    Energy Technology Data Exchange (ETDEWEB)

    Gauthey, Zoé [INRA, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, Aquapôle, quartier Ibarron, 64310 Saint-Pée sur Nivelle (France); Univ Pau & Pays Adour, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, UFR Sciences et Techniques de la Côte Basque, Allée du parc Montaury, 64600 Anglet (France); Panserat, Stéphane [INRA, UR 107, Nutrition Metabolism Aquaculture, Aquapôle, 64310 Saint Pée sur Nivelle (France); Elosegi, Arturo [Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48080 Bilbao (Spain); Herman, Alexandre [INRA, UR 107, Nutrition Metabolism Aquaculture, Aquapôle, 64310 Saint Pée sur Nivelle (France); Tentelier, Cédric [INRA, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, Aquapôle, quartier Ibarron, 64310 Saint-Pée sur Nivelle (France); Univ Pau & Pays Adour, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, UFR Sciences et Techniques de la Côte Basque, Allée du parc Montaury, 64600 Anglet (France); and others

    2016-01-15

    Environmental stochasticity is expected to shape life histories of species, wherein organisms subjected to strong environmental variation should display adaptive response by being able to tune their reproductive investment. For riverine ecosystems, climate models forecast an increase in the frequency and intensity of extreme events such as floods and droughts. The speed and the mechanisms by which organisms may adapt their reproductive investment are therefore of primary importance to understand how species will cope with such radical environmental changes. In the present study, we sampled spawners from two different populations of wild brown trout, originating from two environments with contrasting levels of flow stochasticity. We placed them in sympatry within an experimental channel during reproductive season. In one modality, water flow was maintained constant, whereas in another modality, water flow was highly variable. Reproductive investment of all individuals was monitored using weight and energetic plasma metabolite variation throughout the reproductive season. Only the populations originating from the most variable environment showed a plastic response to experimental manipulation of water flow, the females being able to reduce their weight variation (from 19.2% to 13.1%) and metabolites variations (from 84.2% to 18.6% for triglycerides for instance) under variable flow conditions. These results imply that mechanisms to cope with environmental stochasticity can differ between populations of the same species, where some populations can be plastic whereas other cannot. - Highlights: • We place two populations of brown trout under contrasting water flow for reproduction. • Energetic metabolite variation is used as a cue of reproductive investment. • In constant flow, both populations show the same reproductive investment. • In variable flow, only one of the populations modifies its reproductive investment. • Divergent evolution of reproductive

  20. Experimental evidence of population differences in reproductive investment conditional on environmental stochasticity

    International Nuclear Information System (INIS)

    Gauthey, Zoé; Panserat, Stéphane; Elosegi, Arturo; Herman, Alexandre; Tentelier, Cédric

    2016-01-01

    Environmental stochasticity is expected to shape life histories of species, wherein organisms subjected to strong environmental variation should display adaptive response by being able to tune their reproductive investment. For riverine ecosystems, climate models forecast an increase in the frequency and intensity of extreme events such as floods and droughts. The speed and the mechanisms by which organisms may adapt their reproductive investment are therefore of primary importance to understand how species will cope with such radical environmental changes. In the present study, we sampled spawners from two different populations of wild brown trout, originating from two environments with contrasting levels of flow stochasticity. We placed them in sympatry within an experimental channel during reproductive season. In one modality, water flow was maintained constant, whereas in another modality, water flow was highly variable. Reproductive investment of all individuals was monitored using weight and energetic plasma metabolite variation throughout the reproductive season. Only the populations originating from the most variable environment showed a plastic response to experimental manipulation of water flow, the females being able to reduce their weight variation (from 19.2% to 13.1%) and metabolites variations (from 84.2% to 18.6% for triglycerides for instance) under variable flow conditions. These results imply that mechanisms to cope with environmental stochasticity can differ between populations of the same species, where some populations can be plastic whereas other cannot. - Highlights: • We place two populations of brown trout under contrasting water flow for reproduction. • Energetic metabolite variation is used as a cue of reproductive investment. • In constant flow, both populations show the same reproductive investment. • In variable flow, only one of the populations modifies its reproductive investment. • Divergent evolution of reproductive

  1. Occupational Therapy and Sexual and Reproductive Health Promotion in Adolescence: A Case Study.

    Science.gov (United States)

    Gontijo, Daniela Tavares; de Sena e Vasconcelos, Anna Carolina; Monteiro, Rosana Juliet Silva; Facundes, Vera Lúcia Dutra; Trajano, Maria de Fátima Cordeiro; de Lima, Luciane Soares

    2016-03-01

    Occupational therapy can contribute to sexual and reproductive health through health education. The purpose of this study was to describe an occupational therapy intervention aimed at sexual and reproductive health promotion in adolescents. Fifty-eight adolescents were involved in the study, before, during and after the interventions. Educative activities such as puzzles, storytelling, mime and board games were used, which occupational therapy faculty and students had constructed. The games were employed as mediators for gaining knowledge in sexual and reproductive health. Outcome was measured using a questionnaire, audio recordings and field diaries. The data were analysed by descriptive statistics and thematic content analysis. The results showed the adolescents' increased knowledge of sexual and reproductive health information immediately after the intervention. The thematic analysis was grouped into three categories: the adolescents' initial expectations regarding the project, reflections on the process experienced during the interventions and use of educational games by occupational therapists. The importance of rapport and dialogue was highlighted in the construction of interventions based on participatory methods. The absence of a longitudinal follow-up is a limitation in this study. Further research is important to systematically assess sexual health promotion strategies in adolescence. Copyright © 2015 John Wiley & Sons, Ltd.

  2. Reproduction of Meloidogyne incognita on Winter Cover Crops Used in Cotton Production.

    Science.gov (United States)

    Timper, Patricia; Davis, Richard F; Tillman, P Glynn

    2006-03-01

    Substantial reproduction of Meloidogyne incognita on winter cover crops may lead to damaging populations in a subsequent cotton (Gossypium hirsutum) crop. The amount of population increase during the winter depends on soil temperature and the host status of the cover crop. Our objectives were to quantify M. incognita race 3 reproduction on rye (Secale cereale) and several leguminous cover crops and to determine if these cover crops increase population densities of M. incognita and subsequent damage to cotton. The cover crops tested were 'Bigbee' berseem clover (Trifolium alexandrinum), 'Paradana' balansa clover (T. balansae), 'AU Sunrise' and 'Dixie' crimson clover (T. incarnatum), 'Cherokee' red clover (T. pratense), common and 'AU Early Cover' hairy vetch (Vicia villosa), 'Cahaba White' vetch (V. sativa), and 'Wrens Abruzzi' rye. In the greenhouse tests, egg production was greatest on berseem clover, Dixie crimson clover, AU Early Cover hairy vetch, and common hairy vetch; intermediate on Balansa clover and AU Sunrise crimson clover; and least on rye, Cahaba White vetch, and Cherokee red clover. In both 2002 and 2003 field tests, enough heat units were accumulated between 1 January and 20 May for the nematode to complete two generations. Both AU Early Cover and common hairy vetch led to greater root galling than fallow in the subsequent cotton crop; they also supported high reproduction of M. incognita in the greenhouse. Rye and Cahaba White vetch did not increase root galling on cotton and were relatively poor hosts for M. incognita. Only those legumes that increased populations of M. incognita reduced cotton yield. In the southern US, M. incognita can complete one to two generations on a susceptible winter cover crop, so cover crops that support high nematode reproduction may lead to damage and yield losses in the following cotton crop. Planting rye or Meloidogyne-resistant legumes as winter cover crops will lower the risk of increased nematode populations

  3. Two-photon spin generation and detection

    International Nuclear Information System (INIS)

    Miah, M Idrish

    2009-01-01

    A time- and polarization-resolved two-photon pump-probe investigation is performed in lightly doped GaAs. We generate spin-polarized electrons in bulk GaAs at various temperatures using right-circularly polarized two-photon excitation and detect them by probing the spin-dependent transmission of the sample. The spin polarization (P) of conduction band electrons, as measured using probe pulses with the same (right) and opposite (left) circular polarization, is measured in dependences of pump-probe delay (Δt), lattice temperature (T L ), doping density (n) as well as of the excess photon energy ΔE 2ω = ℎ2ω - E g , where E g is the band gap energy. P is found to be decayed with Δt and enhanced with the decrease in T L or the increase in n. It is also found that P decreases with the increase in ΔE 2ω and depolarizes rapidly for ΔE 2ω > ΔE SO , where ΔE SO is the spin-orbit splitting energy. The results demonstrate that due to a much longer absorption depth highly polarized spins can be generated optically by two-photon pumping of bulk semiconductors.

  4. Study on liquid-metal MHD power generation system with two-phase natural circulation. Applicability to fast reactor conditions

    International Nuclear Information System (INIS)

    Saito, Masaki

    2000-03-01

    Feasibility study of the liquid-metal MHD power generation system combined with the high-density two-phase natural circulation has been performed for the applicability to the simple, autonomic energy conversion system of the liquid-metal cooled fast reactor. The present system has many promising aspects not only in the energy conversion process, but also in safety and economical improvements of the liquid-metal cooled fast reactor. For example, the high cycle efficiency can be expected because of the similarity of the present cycle to the Ericsson cycle. Sodium-Water Interaction problem can be excluded by proper combination of the working fluids. As the economical feature, the present system is so simple that the liquid-metal main circular pump, the steam turbine generator, and even the steam generator can be excluded if the thermodynamic working fluid is injected directly into the high temperature liquid metal MHD working fluid. In addition, the present system has the potential to be applied to various heat sources including solar energy because of the high flexibility of the operation temperature. In the present paper, as the first step of the feasibility study, the cycle analyses were performed to examine the effects of the main system parameters on the fundamental characteristics of the system. It is found that the cycle efficiency of the present system is enough competitive with that of the conventional steam turbine system. It is, however, found that the cycle efficiency depends strongly on the gas-liquid slip ratio in the two-phase flow channel. As the conclusions, it is recommended to perform experimental study to obtain the fundamental data, such as the gas-liquid slip ratio in the high-density liquid-metal two-phase natural circulation. (author)

  5. Cell Size Influences the Reproductive Potential and Total Lifespan of the Saccharomyces cerevisiae Yeast as Revealed by the Analysis of Polyploid Strains

    Directory of Open Access Journals (Sweden)

    Renata Zadrag-Tecza

    2018-01-01

    Full Text Available The total lifespan of the yeast Saccharomyces cerevisiae may be divided into two phases: the reproductive phase, during which the cell undergoes mitosis cycles to produce successive buds, and the postreproductive phase, which extends from the last division to cell death. These phases may be regulated by a common mechanism or by distinct ones. In this paper, we proposed a more comprehensive approach to reveal the mechanisms that regulate both reproductive potential and total lifespan in cell size context. Our study was based on yeast cells, whose size was determined by increased genome copy number, ranging from haploid to tetraploid. Such experiments enabled us to test the hypertrophy hypothesis, which postulates that excessive size achieved by the cell—the hypertrophy state—is the reason preventing the cell from further proliferation. This hypothesis defines the reproductive potential value as the difference between the maximal size that a cell can reach and the threshold value, which allows a cell to undergo its first cell cycle and the rate of the cell size to increase per generation. Here, we showed that cell size has an important impact on not only the reproductive potential but also the total lifespan of this cell. Moreover, the maximal cell size value, which limits its reproduction capacity, can be regulated by different factors and differs depending on the strain ploidy. The achievement of excessive size by the cell (hypertrophic state may lead to two distinct phenomena: the cessation of reproduction without “mother” cell death and the cessation of reproduction with cell death by bursting, which has not been shown before.

  6. Children's Concepts of Reproduction

    Science.gov (United States)

    Moore, James E.; Kendall, Diane G.

    1971-01-01

    Results of this study provide little support for either Freudian or Piagetian theorizing about what the young child thinks of reproduction. Implications for sex education and reproduction information are presented. (Author/CJ)

  7. Two-phase flow field simulation of horizontal steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Rabiee, Ataollah; Kamalinia, Amir Hossein; Hadad, Kamal [School of Mechanical Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of)

    2017-02-15

    The analysis of steam generators as an interface between primary and secondary circuits in light water nuclear power plants is crucial in terms of safety and design issues. VVER-1000 nuclear power plants use horizontal steam generators which demand a detailed thermal hydraulics investigation in order to predict their behavior during normal and transient operational conditions. Two phase flow field simulation on adjacent tube bundles is important in obtaining logical numerical results. However, the complexity of the tube bundles, due to geometry and arrangement, makes it complicated. Employment of porous media is suggested to simplify numerical modeling. This study presents the use of porous media to simulate the tube bundles within a general-purpose computational fluid dynamics code. Solved governing equations are generalized phase continuity, momentum, and energy equations. Boundary conditions, as one of the main challenges in this numerical analysis, are optimized. The model has been verified and tuned by simple two-dimensional geometry. It is shown that the obtained vapor volume fraction near the cold and hot collectors predict the experimental results more accurately than in previous studies.

  8. Vinclozolin: a feasibility and sensitivity study of the ILSI-HESI F1-extended one-generation rat reproduction protocol.

    Science.gov (United States)

    Schneider, Steffen; Kaufmann, Wolfgang; Strauss, Volker; van Ravenzwaay, Bennard

    2011-02-01

    Feasibility of the ILSI-HESI (ACSA) extended one-generation protocol was tested with vinclozolin (dietary 0, 4, 20, 100mg/kg/day). Parental Wistar rats (n=25/sex/dose) were dosed pre-mating (males 4, females 2 weeks) through F1 offspring weaning (postnatal day PND21); F1 dosing continued through PND70. At PND21, 3 subsets (each 1 pup/sex/litter) were selected for neurotoxicology (functional observational battery, motor activity, neuropathology), clinical pathology (hematology, clinical chemistry, urinalysis, thyroid hormone assay) (subsets 1a, 1b; each n=10/sex/dose), immunotoxicology (IgM) SRBC antibody response and natural killer cell assays (subset 2; n=25/sex/dose), and estrus cycle (subset 3; n=25/dose). Vinclozolin reduced parental and offspring bodyweight and prostate, seminal vesicles and epididymides weight, and increased adrenal weight/induced adrenal cortical hypertrophy at 100mg/kg. Mating, fertility, gestation and lactation were unaffected. At 20 and 100mg/kg, F1 males had reduced anogenital distance and retained areolae; at 100mg/kg only, there was hypospadias, purulent prostatitis and seminal vesicle inflammation with atrophy, and Leydig cell hyperplasia, and in F1 females accelerated vaginal opening. These effects are consistent with vinclozolin's known anti-androgenic developmental effects. Neuro- and immunotoxicology tests were unaffected. F1 Only T4 was reduced at 20 and 100mg/kg. The overall sensitivity of the extended one-generation protocol is comparable to or even greater than the current two-generation study. Thus it reduces animal use while maintaining or enhancing information for risk assessment. Copyright © 2010 Elsevier Inc. All rights reserved.

  9. Reproductive strategies in snakes.

    Science.gov (United States)

    Shine, Richard

    2003-05-22

    Snakes of both sexes display remarkable flexibility and diversity in their reproductive tactics. Many features of reproduction in female snakes (such as reproductive mode and frequency, seasonality and multiple mating) allow flexible maternal control. For example, females can manipulate not only the genotypes of their offspring (through mate choice or enhanced sperm competition) but also the phenotypes of their offspring (through allocation 'decisions', behavioural and physiological thermoregulation, and nest-site selection). Reliance on stored energy ('capital') to fuel breeding results in low frequencies of female reproduction and, in extreme cases, semelparity. A sophisticated vomeronasal system not only allows male snakes to locate reproductive females by following scent trails, but also facilitates pheromonally mediated mate choice by males. Male-male rivalry takes diverse forms, including female mimicry and mate guarding; combat bouts impose strong selection for large body size in males of some species. Intraspecific (geographical) variation and phenotypic plasticity in a wide array of reproductive traits (offspring size and number; reproductive frequency; incidence of multiple mating; male tactics such as mate guarding and combat; mate choice criteria) provide exceptional opportunities for future studies.

  10. Reproductive success and failure: the role of winter body mass in reproductive allocation in Norwegian moose.

    Science.gov (United States)

    Milner, Jos M; van Beest, Floris M; Solberg, Erling J; Storaas, Torstein

    2013-08-01

    A life history strategy that favours somatic growth over reproduction is well known for long-lived iteroparous species, especially in unpredictable environments. Risk-sensitive female reproductive allocation can be achieved by a reduced reproductive effort at conception, or the subsequent adjustment of investment during gestation or lactation in response to unexpected environmental conditions or resource availability. We investigated the relative importance of reduced investment at conception compared with later in the reproductive cycle (i.e. prenatal, perinatal or neonatal mortality) in explaining reproductive failure in two high-density moose (Alces alces) populations in southern Norway. We followed 65 multiparous, global positioning system (GPS)-collared females throughout the reproductive cycle and focused on the role of maternal nutrition during gestation in determining reproductive success using a quasi-experimental approach to manipulate winter forage availability. Pregnancy rates in early winter were normal (≥0.8) in all years while spring calving rates ranged from 0.4 to 0.83, with prenatal mortality accounting for most of the difference. Further losses over summer reduced autumn recruitment rates to 0.23-0.69, despite negligible predation. Over-winter mass loss explained variation in both spring calving and autumn recruitment success better than absolute body mass in early or late winter. Although pregnancy was related to body mass in early winter, overall reproductive success was unrelated to pre-winter body condition. We therefore concluded that reproductive success was limited by winter nutritional conditions. However, we could not determine whether the observed reproductive allocation adjustment was a bet-hedging strategy to maximise reproduction without compromising survival or whether females were simply unable to invest more resources in their offspring.

  11. GENETIC STUDIES ON REPRODUCTIVE PERFORMANCE OF INDIGENOUS GOATS IN NORTHERN ODISHA

    Directory of Open Access Journals (Sweden)

    S.Ray

    2016-12-01

    Full Text Available Data on the reproductive parameters of 622 does, sired by 28 bucks, born during the period of 3 years from 2012 to 2015 in 28 villages of three districts viz. Deogarh, Keonjhar and Balasore of Odisha, India were included in the present study. It was observed in the present study that these goats in north Odisha attain sexual maturity at 249.15±1.01 days weighing 9.47±0.53 kg and drop the first kid at an average age of 410.72±1.17 days weighing 13.52±0.62 kg. Season of birth had no significant effect on any of the reproduction traits. The heritability estimates of age at sexual maturity, weight at sexual maturity, age at first kidding, weight at sexual maturity and kidding interval were found to be 0.18±0.08, 0.34±0.11, 0.26±0.19, 0.31±0.07, 0.36±0.12, respectively. Except kidding interval all other reproductive traits of economic importance showed moderate to high and positive genetic and phenotypic correlations ranging from 0.17±0.16 to 0.84±0.12.

  12. Knockout of the Gnrh genes in zebrafish: effects on reproduction and potential compensation by reproductive and feeding-related neuropeptides.

    Science.gov (United States)

    Marvel, Miranda; Spicer, Olivia Smith; Wong, Ten-Tsao; Zmora, Nilli; Zohar, Yonathan

    2018-04-04

    Gonadotropin-releasing hormone (GnRH) is known as a pivotal upstream regulator of reproduction in vertebrates. However, reproduction is not compromised in the hypophysiotropic Gnrh3 knockout line in zebrafish (gnrh3-/-). In order to determine if Gnrh2, the only other Gnrh isoform in zebrafish brains, is compensating for the loss of Gnrh3, we generated a double Gnrh knockout zebrafish line. Surprisingly, the loss of both Gnrh isoforms resulted in no major impact on reproduction, indicating that a compensatory response, outside of the Gnrh system, was evoked. A plethora of factors acting along the reproductive hypothalamus-pituitary axis were evaluated as possible compensators based on neuroanatomical and differential gene expression studies. In addition, we also examined the involvement of feeding factors in the brain as potential compensators for Gnrh2, which has known anorexigenic effects. We found that the double knockout fish exhibited upregulation of several genes in the brain, specifically gonadotropin-inhibitory hormone (gnih), secretogranin 2 (scg2), tachykinin 3a (tac3a), and pituitary adenylate cyclase-activating peptide 1 (pacap1), and downregulation of agouti-related peptide 1 (agrp1), indicating the compensation occurs outside of Gnrh cells and therefore is a non-cell autonomous response to the loss of Gnrh. While the differential expression of gnih and agrp1 in the double knockout line was confined to the periventricular nucleus and hypothalamus, respectively, the upregulation of scg2 corresponded with a broader neuronal redistribution in the lateral hypothalamus and hindbrain. In conclusion, our results demonstrate the existence of a redundant reproductive regulatory system that comes into play when Gnrh2 and Gnrh3 are lost.

  13. Unisexual reproduction of Cryptococcus gattii.

    Directory of Open Access Journals (Sweden)

    Sujal S Phadke

    Full Text Available Cryptococcus gattii is a basidiomycetous human fungal pathogen that typically causes infection in tropical and subtropical regions and is responsible for an ongoing outbreak in immunocompetent individuals on Vancouver Island and in the Pacific Northwest of the US. Pathogenesis of this species may be linked to its sexual cycle that generates infectious propagules called basidiospores. A marked predominance of only one mating type (α in clinical and environmental isolates suggests that a-α opposite-sex reproduction may be infrequent or geographically restricted, raising the possibility of an alternative unisexual cycle involving cells of only α mating type, as discovered previously in the related pathogenic species Cryptococcus neoformans. Here we report observation of hallmark features of unisexual reproduction in a clinical isolate of C. gattii (isolate 97/433 and describe genetic and environmental factors conducive to this sexual cycle. Our results are consistent with population genetic evidence of recombination in the largely unisexual populations of C. gattii and provide a useful genetic model for understanding how novel modes of sexual reproduction may contribute to evolution and virulence in this species.

  14. Reproductive isolation and local adaptation quantified for a chromosome inversion in a malaria mosquito.

    Science.gov (United States)

    Ayala, Diego; Guerrero, Rafael F; Kirkpatrick, Mark

    2013-04-01

    Chromosome inversions have long been thought to be involved in speciation and local adaptation. We have little quantitative information, however, about the effects that inversion polymorphisms have on reproductive isolation and viability. Here we provide the first estimates from any organism for the total amount of reproductive isolation associated with an inversion segregating in natural populations. We sampled chromosomes from 751 mosquitoes of the malaria vector Anopheles funestus along a 1421 km transect in Cameroon that traverses savannah, highland, and rainforest ecological zones. We then developed a series of population genetic models that account for selection, migration, and assortative mating, and fit the models to the data using likelihood. Results from the best-fit models suggest there is strong local adaptation, with relative viabilities of homozygotes ranging from 25% to 130% compared to heterozygotes. Viabilities vary qualitatively between regions: the inversion is underdominant in the savannah, whereas in the highlands it is overdominant. The inversion is also implicated in strong assortative mating. In the savannah, the two homozygote forms show 92% reproductive isolation, suggesting that this one inversion can generate most of the genetic barriers needed for speciation. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  15. Association between AA-NAT gene polymorphism and reproductive performance in sheep

    OpenAIRE

    Ding-ping,Bai; Cheng-jiang,Yu; Yu-lin,Chen

    2012-01-01

    Arylalkylamine N-acetyltransferase (AA-NAT) is critical enzyme in Melatonin (MLT) biosynthesis for MLT regulating the animal seasonal breeding. In this study, DNA sequencing methods were applied to detect the polymorphisms of the AA-NAT gene in 179 Chinese sheep belonging to two non-seasonal reproduction breeds and two seasonal reproduction breeds. One mutation at exon 3 (NM_001009461:c.486A > G) was firstly described at the sheep AA-NAT locus. Hence, we described the SmaI PCR-RFLP m...

  16. The Multigenerational Workforce within Two-Year Public Community Colleges: A Study of Generational Factors Affecting Employee Learning and Interaction

    Science.gov (United States)

    Starks, Florida Elizabeth

    2014-01-01

    The purpose of this quantitative study is to broaden multigenerational workforce research involving factors affecting employee learning and interaction by using a population of Baby Boomer, Generation X, and Millennial faculty and staff age cohorts employed at two-year public community college organizations. Researchers have studied…

  17. [Importance of reproductive biotechnology in cattle in Europe].

    Science.gov (United States)

    Wrenzycki, C; Stinshoff, H

    2015-01-01

    Reproductive biotechnology has manifold applications and includes a great innovation potential in livestock. Due to the global changes the new findings and techniques can aid to meet the future challenges. The use of biotechnology in animal production can guarantee enough high quality food for the whole population. Genetic resources of animals can be preserved via sperm and embryo banking. Early diagnosis of hereditary defects, generation of offspring with predetermined sex and the avoidance of animal transports for breeding employing shipment of frozen embryos will improve animal welfare. A special application is the use of animal models for human assisted reproductive technologies. Therefore, not only in Germany research related to the methodologies in reproductive biotechnology and their improvement need to be supported.

  18. Sexual reproduction and the evolution of microbial pathogens.

    Science.gov (United States)

    Heitman, Joseph

    2006-09-05

    Three common systemic human fungal pathogens--Cryptococcus neoformans, Candida albicans and Aspergillus fumigatus--have retained all the machinery to engage in sexual reproduction, and yet their populations are often clonal with limited evidence for recombination. Striking parallels have emerged with four protozoan parasites that infect humans: Toxoplasma gondii, Trypanosoma brucei, Trypanosoma cruzi and Plasmodium falciparum. Limiting sexual reproduction appears to be a common virulence strategy, enabling generation of clonal populations well adapted to host and environmental niches, yet retaining the ability to engage in sexual or parasexual reproduction and respond to selective pressure. Continued investigation of the sexual nature of microbial pathogens should facilitate both laboratory investigation and an understanding of the complex interplay between pathogens, hosts, vectors, and their environments.

  19. The ecology and evolutionary endocrinology of reproduction in the human female.

    Science.gov (United States)

    Vitzthum, Virginia J

    2009-01-01

    Human reproductive ecology (HRE) is the study of the mechanisms that link variation in reproductive traits with variation in local habitats. Empirical and theoretical contributions from biological anthropology, physiology, and demography have established the foundation necessary for developing a comprehensive understanding, grounded in life history theory (LHT), of temporal, individual, and populational variation in women's reproductive functioning. LHT posits that natural selection leads to the evolution of mechanisms that tend to allocate resources to the competing demands of growth, reproduction, and survival such that fitness is locally maximized. (That is, among alternative allocation patterns exhibited in a population, those having the highest inclusive fitness will become more common over generational time.) Hence, strategic modulation of reproductive effort is potentially adaptive because investment in a new conception may risk one's own survival, future reproductive opportunities, and/or current offspring survival. The hypothalamic-pituitary-ovarian (HPO) axis is the principal neuroendocrine pathway by which the human female modulates reproductive functioning according to the changing conditions in her habitat. Adjustments of reproductive investment in a potential conception are manifested in temporal and individual variation in ovarian cycle length, ovulation, hormone levels, and the probability of conception. Understanding the extent and causes of adaptive and non-adaptive variation in ovarian functioning is fundamental to ascertaining the proximate and remote determinants of human reproductive patterns. In this review I consider what is known and what still needs to be learned of the ecology of women's reproductive biology, beginning with a discussion of the principal explanatory frameworks in HRE and the biometry of ovarian functioning. Turning next to empirical studies, it is evident that marked variation between cycles, women, and populations is the

  20. Differential expression patterns of PQRFamide peptide and its two receptor genes in the brain and pituitary of grass puffer during the reproductive cycle.

    Science.gov (United States)

    Shahjahan, Md; Doi, Hiroyuki; Ando, Hironori

    2015-01-01

    Pain-modulatory neuropeptides, PQRFamide (PQRFa) peptides, have recently been implicated in the regulation of reproduction in fish. As a first step toward investigating the role of PQRFa peptides on reproductive function in the grass puffer Takifugu niphobles, which is a semilunar spawner, we cloned genes encoding PQRFa peptide precursor (pqrfa) and its two types of receptors (pqrfa-r1 and pqrfa-r2), and examined changes in their expression levels in the brain and pituitary over several months during the reproductive cycle. The grass puffer PQRFa peptide precursor of 126 amino acid residues contains two putative PQRFa peptides, PQRFa-1 and PQRFa-2, which correspond to NPFF and NPAF in other vertebrates, respectively. The grass puffer PQRFa-R1 and PQRFa-R2 consist of 426 and 453 amino acid residues, respectively, and contain distinct characteristics of G-protein coupled receptors. These three genes were exclusively expressed in the brain and pituitary. The expression levels of pqrfa and pqrfa-r1 were significantly increased during the late stage of sexual maturation, but low in the spawning fish just after releasing sperms and eggs. Therefore, the grass puffer PQRFa peptide may have a role in the late stage of sexual maturation before spawning via PQRFa-R1. In contrast, the pqrfa-r2 expression showed maximum levels in the spawning fish and in the post-spawning period. The present results provide fundamental data suggesting that the grass puffer PQRFa peptide may have multiple roles in the control of reproduction that are dependent on the reproductive stages. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. The effect of ionizing radiation on reproductive potential of Tetranychus urticae Koch. spider and its response to pesticides

    International Nuclear Information System (INIS)

    Zil'bermints, I.V.; Zhuravleva, L.M.; Dubovoj, V.P.

    1988-01-01

    It was shown that even a single exposure of spider (tetranychus urticae Koch.) to ionizing radiation changes its reproductive potency, shortens the life span of females, reduces the time of laying and causes unfavourable shifts in sex ratio within at least two generations, whereas its response to pesticides does not change

  2. Sex-specific inhibition and stimulation of worker-reproductive transition in a termite

    Science.gov (United States)

    Sun, Qian; Haynes, Kenneth F.; Hampton, Jordan D.; Zhou, Xuguo

    2017-10-01

    In social insects, the postembryonic development of individuals exhibits strong phenotypic plasticity in response to the environment, thus generating the caste system. Different from eusocial Hymenoptera, in which queens dominate reproduction and inhibit worker fertility, the primary reproductive caste in termites (kings and queens) can be replaced by neotenic reproductives derived from functionally sterile individuals. Feedback regulation of nestmate differentiation into reproductives has been suggested, but the sex specificity remains inconclusive. In the eastern subterranean termite, Reticulitermes flavipes, we tested the hypothesis that neotenic reproductives regulate worker-reproductive transition in a sex-specific manner. With this R. flavipes system, we demonstrate a sex-specific regulatory mechanism with both inhibitory and stimulatory functions. Neotenics inhibit workers of the same sex from differentiating into additional reproductives but stimulate workers of the opposite sex to undergo this transition. Furthermore, this process is not affected by the presence of soldiers. Our results highlight the reproductive plasticity of termites in response to social cues and provide insights into the regulation of reproductive division of labor in a hemimetabolous social insect.

  3. Seasonal life history trade-offs in two leafwing butterflies: Delaying reproductive development increases life expectancy.

    Science.gov (United States)

    McElderry, Robert M

    2016-04-01

    Surviving inhospitable periods or seasons may greatly affect fitness. Evidence of this exists in the prevalence of dormant stages in the life cycles of most insects. Here I focused on butterflies with distinct seasonal morphological types (not a genetic polymorphism) in which one morphological type, or form, delays reproduction until favorable conditions return, while the other form develops in an environment that favors direct reproduction. For two butterflies, Anaea aidea and A. andria, I tested the hypothesis that the development of each seasonal form involves a differential allocation of resources to survival at eclosion. I assayed differences in adult longevity among summer and winter forms in either a warm, active environment or a cool, calm environment. Winter form adults lived 40 times longer than summer form but only in calm, cool conditions. The magnitude of this difference provided compelling evidence that the winter form body plan and metabolic strategy (i.e. resource conservatism) favor long term survival. This research suggests that winter form adults maintain lowered metabolic rate, a common feature of diapause, to conserve resources and delay senescence while overwintering. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Studies on reproductive abscission and seed yield of mungbean ...

    African Journals Online (AJOL)

    A field study was conducted on the Research and Experimental Farm of the University of Agriculture Makurdi (7o41'N, 08o37'N, and 400 m above mean sea level), Nigeria, in 2001 and 2002 to examine the abscission of reproductive structures in mungbean (Vigna radiata). Four exotic cultivars (VC 2768A, VC 1178A, VC ...

  5. Effect of feeding frequency on the reproductive efficiency of two species of Triatoma with different epidemiological importance

    Directory of Open Access Journals (Sweden)

    Claudia Rodríguez

    2014-07-01

    Full Text Available Introduction In Triatominae, reproductive efficiency is an important factor influencing population dynamics, and a useful parameter in measuring a species' epidemiological significance as a vector of Trypanosoma cruzi (Chagas, 1909. The reproductive efficiency of triatomines is affected by food availability; hence, we measured and compared the effects of feeding frequency on the reproductive parameters of Triatoma patagonica (Del Ponte, 1929 and Triatoma infestans (Klug, 1934, and the effects of starvation on T. patagonica. Methods Couples from both species were fed weekly, or every 3 weeks; in addition, females in couples of T. patagonica were not fed. Each couple was observed weekly and reproductive efficiency was assessed on the following parameters: fecundity (eggs/female, fertility (eggs hatched/eggs laid, initiation and end of oviposition, initiation of mating, number of matings/week, and number of reproductive weeks. Relative meal size index (RMS, blood consumption index (CI, and E values (eggs/mg blood were also calculated. Results Changes in feeding frequency affected the reproductive parameters of T. patagonica only, with a decrease in fecundity and number of reproductive weeks for those fed every 3 weeks, or not fed. The reproductive period, RMS index, and CI were lower for T. patagonica than T. infestans. However, despite the lower fecundity of T. patagonica, this species required less blood to produce eggs, with an E values of 2 compared to 2.94 for T. infestans. Conclusions Our results suggest that the differences in fecundity observed between species reflect the availability of food in their natural ecotopes.

  6. Reproductive endocrinology of vitamin D.

    Science.gov (United States)

    Lorenzen, Mette; Boisen, Ida Marie; Mortensen, Li Juel; Lanske, Beate; Juul, Anders; Blomberg Jensen, Martin

    2017-09-15

    Vitamin D is a versatile hormone with several functions beyond its well-established role in maintenance of skeletal health and calcium homeostasis. The effects of vitamin D are mediated by the vitamin D receptor, which is expressed together with the vitamin D metabolizing enzymes in the reproductive tissues. The reproductive organs are therefore responsive to and able to metabolize vitamin D locally. The exact role remains to be clarified but several studies have suggested a link between vitamin D and production/release of reproductive hormones into circulation, which will be the main focus of this review. Current evidence is primarily based on small human association studies and rodent models. This highlights the need for randomized clinical trials, but also functional animal and human in vitro studies, and larger, prospective cohort studies are warranted. Given the high number of men and women suffering from reproductive problems and abnormal endocrinology research addressing the role of vitamin D in reproductive endocrinology may be of clinical importance. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Two-photon spin generation and detection

    Energy Technology Data Exchange (ETDEWEB)

    Miah, M Idrish, E-mail: m.miah@griffith.edu.a [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)

    2009-02-21

    A time- and polarization-resolved two-photon pump-probe investigation is performed in lightly doped GaAs. We generate spin-polarized electrons in bulk GaAs at various temperatures using right-circularly polarized two-photon excitation and detect them by probing the spin-dependent transmission of the sample. The spin polarization (P) of conduction band electrons, as measured using probe pulses with the same (right) and opposite (left) circular polarization, is measured in dependences of pump-probe delay ({Delta}t), lattice temperature (T{sub L}), doping density (n) as well as of the excess photon energy {Delta}E{sub 2{omega}}= {h_bar}2{omega} - E{sub g}, where E{sub g} is the band gap energy. P is found to be decayed with {Delta}t and enhanced with the decrease in T{sub L} or the increase in n. It is also found that P decreases with the increase in {Delta}E{sub 2{omega}}and depolarizes rapidly for {Delta}E{sub 2{omega}}> {Delta}E{sub SO}, where {Delta}E{sub SO} is the spin-orbit splitting energy. The results demonstrate that due to a much longer absorption depth highly polarized spins can be generated optically by two-photon pumping of bulk semiconductors.

  8. Reproductive behaviour repertoire of semi-captive lowland tapir Tapirus terrestris (Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Luisa Brusius

    2007-12-01

    Full Text Available The reproductive behaviour of five male and two female semi-captive Tapirus terrestris was investigated for two years without interruption. They were fenced in a 160 hectare area, in Santa Catarina State, South of Brazil. Data was collected whenever an animal exhibited reproductive behaviour. Seven behaviours, observed in eleven reproductive events, were divided into three categories: courtship, copulation and post-copulation. The tapirs displayed stereotypical patterns of sexual behaviour. No kind of audible vocalization was recorded during the reproductive period. All reproductive activity began in the second quarter of July and continued up to the first half of October, in both years of observation, pointing towards the existence of a reproductive season, corroborated by two births after expected gestation period from copula.

  9. Calibration aspects of binaural sound reproduction over insert earphones

    DEFF Research Database (Denmark)

    Hoffmann, Pablo F.; Markovic, Milos; Olesen, Søren Krarup

    2012-01-01

    Earphones are nowadays widely adopted for the reproduction of audio material in mobile multimedia and communication platforms, e.g. smartphones. Reproduction of high-quality spatial sound on such platforms can dramatically improve their applicability, and since two channels are always available...... in earphone-based reproduction, binaural reproduction can be applied directly. This paper is concerned with the theoretical and practical aspects relevant to the correct reproduction of binaural signals over insert earphones. To this purpose, a theoretical model originally developed to explain the acoustic...

  10. A tobacco cDNA reveals two different transcription patterns in vegetative and reproductive organs

    Directory of Open Access Journals (Sweden)

    I. da Silva

    2002-08-01

    Full Text Available In order to identify genes expressed in the pistil that may have a role in the reproduction process, we have established an expressed sequence tags project to randomly sequence clones from a Nicotiana tabacum stigma/style cDNA library. A cDNA clone (MTL-8 showing high sequence similarity to genes encoding glycine-rich RNA-binding proteins was chosen for further characterization. Based on the extensive identity of MTL-8 to the RGP-1a sequence of N. sylvestris, a primer was defined to extend the 5' sequence of MTL-8 by RT-PCR from stigma/style RNAs. The amplification product was sequenced and it was confirmed that MTL-8 corresponds to an mRNA encoding a glycine-rich RNA-binding protein. Two transcripts of different sizes and expression patterns were identified when the MTL-8 cDNA insert was used as a probe in RNA blots. The largest is 1,100 nucleotides (nt long and markedly predominant in ovaries. The smaller transcript, with 600 nt, is ubiquitous to the vegetative and reproductive organs analyzed (roots, stems, leaves, sepals, petals, stamens, stigmas/styles and ovaries. Plants submitted to stress (wounding, virus infection and ethylene treatment presented an increased level of the 600-nt transcript in leaves, especially after tobacco necrosis virus infection. In contrast, the level of the 1,100-nt transcript seems to be unaffected by the stress conditions tested. Results of Southern blot experiments have suggested that MTL-8 is present in one or two copies in the tobacco genome. Our results suggest that the shorter transcript is related to stress while the larger one is a flower predominant and nonstress-inducible messenger.

  11. [Advances in the study of neuroendocrinological regulation of kisspeptin in fish reproduction].

    Science.gov (United States)

    Zhuo, Qi

    2013-10-01

    Kisspeptin, a key factor in the neuroendocrinological regulation of animal reproduction, is a peptide product encoded by kiss genes, which act as the natural ligand of GPR54. Over the last decade, multiple functional molecular forms of kisspeptin have been found in vertebrate species. In fish, the major molecular structural form is kisspeptin-10. The kisspeptin/GPR54 system has multiple important functions in reproduction. This review provides an overview of our current knowledge on kisspeptin and its role in regulating fish reproductive, including the distribution and location of kisspeptin neurons in the brain, the molecular polymorphism of fish kisspeptin, functional diversity, the molecular mechanism of fish reproductive regulation, and the molecular evolution of kisspeptin as well as the co-regulation of fish reproduction by kisspeptin and other functional molecules. Perspectives on the future of kisspeptin regulation in fish reproduction are also highlighted.

  12. Outcome of assisted reproduction in women with congenital uterine anomalies: a prospective observational study.

    Science.gov (United States)

    Prior, M; Richardson, A; Asif, S; Polanski, L; Parris-Larkin, M; Chandler, J; Fogg, L; Jassal, P; Thornton, J G; Raine-Fenning, N J

    2018-01-01

    To assess the prevalence of congenital uterine anomalies, including arcuate uterus, and their effect on reproductive outcome in subfertile women undergoing assisted reproduction. Consecutive women referred for subfertility between May 2009 and November 2015 who underwent assisted reproduction were included in the study. As part of the initial assessment, each woman underwent three-dimensional transvaginal sonography. Uterine morphology was classified using the modified American Fertility Society (AFS) classification of congenital uterine anomalies proposed by Salim et al. If the external contour of the uterus was uniformly convex or had an indentation of Reproductive outcomes, including live birth, clinical pregnancy and preterm birth, were compared between women with a normal uterus and those with a congenital uterine anomaly. Subgroup analysis by type of uterine morphology and logistic regression analysis adjusted for age, body mass index, levels of anti-Müllerian hormone, antral follicle count and number and day of embryo transfer were performed. A total of 2375 women were included in the study, of whom 1943 (81.8%) had a normal uterus and 432 (18.2%) had a congenital uterine anomaly. The most common anomalies were arcuate (n = 387 (16.3%)) and subseptate (n = 16 (0.7%)) uterus. The rate of live birth was similar between women with a uterine anomaly and those with a normal uterus (35% vs 37%; P = 0.47). The rates of clinical pregnancy, mode of delivery and sex of the newborn were also similar between the two groups. Preterm birth before 37 weeks' gestation was more common in women with uterine anomalies than in controls (22% vs 14%, respectively; P = 0.03). Subgroup analysis by type of anomaly showed no difference in the incidence of live birth and clinical pregnancy for women with an arcuate uterus, but indicated worse pregnancy outcome in women with other major anomalies (P = 0.042 and 0.048, respectively). Congenital uterine anomalies as a whole, when

  13. A Comparison of Methods and Results in Recruiting White and Black Women into Reproductive Studies: The MMC-PSU Cooperative Center on Reproduction Experience

    Science.gov (United States)

    Sweet, Stephanie; Legro, Richard S; Coney, PonJola

    2008-01-01

    Establishing a holistic approach for the enrollment of subjects into clinical trials that includes strategies for the recruitment of non-traditional and minority populations has been an elusive task. The existence of such a design, that is understood and embraced by investigators and the target communities, would streamline the current level of commitment of time, energy and resources. This is necessary to successfully encourage individual and community participation in research studies. The Center for Research in Reproduction at Meharry set out to recruit a large number of African American women volunteers of reproductive age into clinical trials. The experience, of recruiting volunteers from the African American community for clinical trials in the Meharry Medical College/Pennsylvania State University (MMC/PSU)'s Cooperative Center for Research in Reproduction at Meharry, is presented. PMID:18082470

  14. Assisted reproductive technology in Europe, 2006: results generated from European registers by ESHRE

    DEFF Research Database (Denmark)

    de Mouzon, J; Goossens, V; Bhattacharya, S

    2010-01-01

    In this 10th European IVF-monitoring (EIM) report, the results of assisted reproductive techniques from treatments initiated in Europe during 2006 are presented. Data were mainly collected from existing national registers....

  15. Prenatal famine, birthweight, reproductive performance and age at menopause: the Dutch hunger winter families study.

    Science.gov (United States)

    Yarde, F; Broekmans, F J M; van der Pal-de Bruin, K M; Schönbeck, Y; te Velde, E R; Stein, A D; Lumey, L H

    2013-12-01

    Is there an association between acute prenatal famine exposure or birthweight and subsequent reproductive performance and age at menopause? No association was found between intrauterine famine exposure and reproductive performance, but survival analysis showed that women exposed in utero were 24% more likely to experience menopause at any age. Associations between prenatal famine and subsequent reproductive performance have been examined previously with inconsistent results. Evidence for the effects of famine exposure on age at natural menopause is limited to one study of post-natal exposure. This cohort study included men and women born around the time of the Dutch famine of 1944-1945. The study participants (n = 1070) underwent standardized interviews on reproductive parameters at a mean age of 59 years. The participants were grouped as men and women with prenatal famine exposure (n = 407), their same-sex siblings (family controls, n = 319) or other men and women born before or after the famine period (time controls, n = 344). Associations of famine exposure with reproductive performance and menopause were analysed using logistic regression and survival analysis with competing risk, after controlling for family clustering. Gestational famine exposure was not associated with nulliparity, age at birth of first child, difficulties conceiving or pregnancy outcome (all P> 0.05) in men or women. At any given age, women were more likely to experience menopause after gestational exposure to famine (hazard ratio 1.24; 95% CI 1.03, 1.51). The association was not attenuated with an additional control for a woman's birthweight. In this study, there was no association between birthweight and age at menopause after adjustment for gestational famine exposure. Age at menopause was self-reported and assessed retrospectively. The study power to examine associations with specific gestational periods of famine exposure and reproductive function was limited. Our findings support

  16. High-order harmonic generation from a two-dimensional band structure

    Science.gov (United States)

    Jin, Jian-Zhao; Xiao, Xiang-Ru; Liang, Hao; Wang, Mu-Xue; Chen, Si-Ge; Gong, Qihuang; Peng, Liang-You

    2018-04-01

    In the past few years, harmonic generation in solids has attracted tremendous attention. Recently, some experiments of two-dimensional (2D) monolayer or few-layer materials have been carried out. These studies demonstrated that harmonic generation in the 2D case shows a strong dependence on the laser's orientation and ellipticity, which calls for a quantitative theoretical interpretation. In this work, we carry out a systematic study on the harmonic generation from a 2D band structure based on a numerical solution to the time-dependent Schrödinger equation. By comparing with the 1D case, we find that the generation dynamics can have a significant difference due to the existence of many crossing points in the 2D band structure. In particular, the higher conduction bands can be excited step by step via these crossing points and the total contribution of the harmonic is given by the mixing of transitions between different clusters of conduction bands to the valence band. We also present the orientation dependence of the harmonic yield on the laser polarization direction.

  17. [The function of ERα in male reproductive system].

    Science.gov (United States)

    Dong, Yu-Hang; Wei, Jin-Hua; Li, Zhen

    2014-12-01

    Estrogen receptors (ERs), including two sub-types ERα and ERβ, belong to the steroid hormone superfamily of nuclear receptors. ERα distributes in the male reproductive system and plays a crucial role in the regulation of male reproduction through estrogen-dependent and -independent ways. In this article, we mainly reviewed the molecular structure, mode of action and location of ERα in the male reproductive system, and explored the mechanism of ERα in regulating the male reproductive system by analyzing different animal models of disrupted ERα.

  18. Investigating Climate Change and Reproduction: Experimental Tools from Evolutionary Biology

    Directory of Open Access Journals (Sweden)

    Oliver Y. Martin

    2012-09-01

    Full Text Available It is now generally acknowledged that climate change has wide-ranging biological consequences, potentially leading to impacts on biodiversity. Environmental factors can have diverse and often strong effects on reproduction, with obvious ramifications for population fitness. Nevertheless, reproductive traits are often neglected in conservation considerations. Focusing on animals, recent progress in sexual selection and sexual conflict research suggests that reproductive costs may pose an underestimated hurdle during rapid climate change, potentially lowering adaptive potential and increasing extinction risk of certain populations. Nevertheless, regime shifts may have both negative and positive effects on reproduction, so it is important to acquire detailed experimental data. We hence present an overview of the literature reporting short-term reproductive consequences of exposure to different environmental factors. From the enormous diversity of findings, we conclude that climate change research could benefit greatly from more coordinated efforts incorporating evolutionary approaches in order to obtain cross-comparable data on how individual and population reproductive fitness respond in the long term. Therefore, we propose ideas and methods concerning future efforts dealing with reproductive consequences of climate change, in particular by highlighting the advantages of multi-generational experimental evolution experiments.

  19. Male Reproductive Toxicology: Environmental Exposures vs Reproductive Competence

    Science.gov (United States)

    Like the lecture this chapter begins with an overview of male reproductive biology and transitions into male reproductive toxicology. It ends with a brief discussion of the strengths and weaknesses in male reproductive toxicology and epidemiology today. This chapter is highly il...

  20. Attosecond pulse trains generated using two color laser fields

    International Nuclear Information System (INIS)

    Mauritsson, J.; Louisiana State University, Baton Rouge, LA; Johnsson, P.; Gustafsson, E.; L'Hullier, A.; Schafer, K.J.; Gaarde, M.B.

    2006-01-01

    Complete test of publication follows. We present the generation of attosecond pulse trains from a superposition of an infrared (IR) laser field and its second harmonic. Our attosecond pulses are synthesized by selecting a number of synchronized harmonics generated in argon. By adding the second harmonic to the driving field the inversion symmetry of generation process is broken and both odd and even harmonics are generated. Consecutive half cycles in the two color field differ beyond the simple sign change that occurs in a one color field and have very different shapes and amplitudes. This sub-cycle structure of the field, which governs the generation of the attosecond pulses, depends strongly on the relative phase and intensity of the two fields, thereby providing additional control over the generation process. The generation of attosecond pulses is frequently described using the semi-classical three step model where an electron is: (1) ionized through tunneling ionization during one half cycle; (2) reaccelerated back towards the ion core by the next half cycle; where it (3) recombines with the ground-state releasing the access energy in a short burst of light. In the two color field the symmetry between the ionizing and reaccelerating field is broken, which leads to two possible scenarios: the electron can either be ionized during a strong half cycle and reaccelerated by a weaker field or vice versa. The periodicity is a full IR cycle in both cases and hence two trains of attosecond pulses are generated which are offset from each other. The generation efficiency, however, is very different for the two cases since it is determined mainly by the electric field strength at the time of tunneling and one of the trains will therefore dominate the other. We investigate experimentally both the spectral and temporal structure of the generated attosecond pulse trains as a function of the relative phase between the two driving fields. We find that for a wide range of

  1. Female reproductive disorders

    DEFF Research Database (Denmark)

    Crain, D Andrew; Janssen, Sarah J; Edwards, Thea M

    2008-01-01

    To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive disrupti......To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive...... disruptions warrant evaluation of the impact of EDCs on female reproductive health....

  2. 'A machine for recreating life': an introduction to reproduction on film.

    Science.gov (United States)

    Olszynko-Gryn, Jesse; Ellis, Patrick

    2017-09-01

    Reproduction is one of the most persistently generative themes in the history of science and cinema. Cabbage fairies, clones and monstrous creations have fascinated filmmakers and audiences for more than a century. Today we have grown accustomed not only to the once controversial portrayals of sperm, eggs and embryos in biology and medicine, but also to the artificial wombs and dystopian futures of science fiction and fantasy. Yet, while scholars have examined key films and genres, especially in response to the recent cycle of Hollywood 'mom coms', the analytic potential of reproduction on film as a larger theme remains largely untapped. This introduction to a special issue aims to consolidate a disparate literature by exploring diverse strands of film studies that are rarely considered in the same frame. It traces the contours of a little-studied history, pauses to consider in greater detail a few particularly instructive examples, and underscores some promising lines of inquiry. Along the way, it introduces the six original articles that constitute Reproduction on Film.

  3. Reproductive history of cane rat: a review of the reproduction and ...

    African Journals Online (AJOL)

    This study evaluates in a review the reproduction and reproductive performance of cane rat. Breeding time in cane rat depends on which part of Africa the Animal is found and the weather. In the wild, cane rat lives in groups of males and females during the breeding season. The wet season of the year is the usual breeding ...

  4. Acculturation and biobehavioral profiles in pregnant women of Hispanic origin: generational differences.

    Science.gov (United States)

    Ruiz, Roberta J; Stowe, Raymond P; Brown, Adama; Wommack, Joel

    2012-01-01

    In Hispanics, acculturation may lead to negative health outcomes. This study used a cross-sectional design to investigate the psychosocial and biological risks in acculturating pregnant women of Hispanic origin (n = 470). Psychosocial risks-depressive symptoms, anxiety, and stress-were assessed by self-report, whereas biological measures included stress-related and reproductive hormones. Mental health deteriorated across generations, with worsening depression, anxiety, and stress with successive generations. Stress and reproductive hormone levels decreased across generations, whereas body mass index and number of sexual partners increased. These data provide potential biobehavioral explanations of the relationship between acculturation and declining health among Hispanic women in the United States.

  5. New observations on gametogenic development and reproductive experimental tools to support seed yield improvement in cowpea [Vigna unguiculata (L.) Walp].

    Science.gov (United States)

    Salinas-Gamboa, Rigel; Johnson, Susan D; Sánchez-León, Nidia; Koltunow, Anna M G; Vielle-Calzada, Jean-Philippe

    2016-06-01

    Cowpea reproductive tools. Vigna unguiculata L. Walp. (cowpea) is recognized as a major legume food crop in Africa, but seed yields remain low in most varieties adapted to local conditions. The development of hybrid cowpea seed that could be saved after each generation, enabling significant yield increases, will require manipulation of reproductive development from a sexual to an asexual mode. To develop new technologies that could support the biotechnological manipulation of reproductive development in cowpea, we examined gametogenesis and seed formation in two transformable, African-adapted, day-length-insensitive varieties. Here, we show that these two varieties exhibit distinct morphological and phenological traits but share a common developmental sequence in terms of ovule formation and gametogenesis. We present a reproductive calendar that allows prediction of male and female gametogenesis on the basis of sporophytic parameters related to floral bud size and reproductive organ development, determining that gametogenesis occurs more rapidly in the anther than in the ovule. We also show that the mode of megagametogenesis is of the Polygonum-type and not Oenothera-type, as previously reported. Finally, we developed a whole-mount immunolocalization protocol and applied it to detect meiotic proteins in the cowpea megaspore mother cell, opening opportunities for comparing the dynamics of protein localization during male and female meiosis, as well as other reproductive events in this emerging legume model system.

  6. Reproduction in females bufalinas: artificial insemination and assisted reproduction

    International Nuclear Information System (INIS)

    Vale, William G.

    2011-01-01

    Reproductive behavior in females bufalinas has been studied for the detection of estrus. A system that works through radio telemetry has been developed and proposed to replace the daily visual observation to determine the estrous phase with efficiency and precision. The method used is the fixation on the back of the female with a sensor that emits radio waves every time suffer a pressure exerted by the mountain. Waves have been captured by an antenna and sent to a computer system. The knowledge that has been developed on the management and use of reproductive biotechnologies of reproduction in buffalo, have enabled the technicians and breeders evaluate and indicate which procedures can be used successfully, and increase the application of the fixed-time artificial insemination during the year [es

  7. Parthenium weed (Parthenium hysterophorus L.) and climate change: the effect of CO2 concentration, temperature, and water deficit on growth and reproduction of two biotypes.

    Science.gov (United States)

    Nguyen, Thi; Bajwa, Ali Ahsan; Navie, Sheldon; O'Donnell, Chris; Adkins, Steve

    2017-04-01

    Climate change will have a considerable impact upon the processes that moderate weed invasion, in particular to that of parthenium weed (Parthenium hysterophorus L.). This study evaluated the performance of two Australian biotypes of parthenium weed under a range of environmental conditions including soil moisture (100 and 50% of field capacity), atmospheric carbon dioxide (CO 2 ) concentration (390 and 550 ppm), and temperature (35/20 and 30/15 °C/day/night). Measurements were taken upon growth, reproductive output, seed biology (fill, viability and dormancy) and soil seed longevity. Parthenium weed growth and seed output were significantly increased under the elevated CO 2 concentration (550 ppm) and in the cooler (30/15 °C) and wetter (field capacity) conditions. However, elevated CO 2 concentration could not promote growth or seed output when the plants were grown under the warmer (35/20 °C) and wetter conditions. Warm temperatures accelerated the growth of parthenium weed, producing plants with greater height biomass but with a shorter life span. Warm temperatures also affected the reproductive output by promoting both seed production and fill, and promoting seed longevity. Dryer soil conditions (50% of field capacity) also promoted the reproductive output, but did not retain high seed fill or promote seed longevity. Therefore, the rising temperatures, the increased atmospheric CO 2 concentration and the longer periods of drought predicted under climate change scenarios are likely to substantially enhance the growth and reproductive output of these two Australian parthenium weed biotypes. This may facilitate the further invasion of this noxious weed in tropical and sub-tropical natural and agro-ecosystems.

  8. Complexities and potential pitfalls of clinical study design and data analysis in assisted reproduction.

    Science.gov (United States)

    Patounakis, George; Hill, Micah J

    2018-06-01

    The purpose of the current review is to describe the common pitfalls in design and statistical analysis of reproductive medicine studies. It serves to guide both authors and reviewers toward reducing the incidence of spurious statistical results and erroneous conclusions. The large amount of data gathered in IVF cycles leads to problems with multiplicity, multicollinearity, and over fitting of regression models. Furthermore, the use of the word 'trend' to describe nonsignificant results has increased in recent years. Finally, methods to accurately account for female age in infertility research models are becoming more common and necessary. The pitfalls of study design and analysis reviewed provide a framework for authors and reviewers to approach clinical research in the field of reproductive medicine. By providing a more rigorous approach to study design and analysis, the literature in reproductive medicine will have more reliable conclusions that can stand the test of time.

  9. Variation in circulating testosterone during mating predicts reproductive success in a wild songbird.

    Directory of Open Access Journals (Sweden)

    Beate Apfelbeck

    2016-08-01

    Full Text Available Testosterone is an important sex hormone and mediates reproduction in male vertebrates. There is ample evidence that testosterone coordinates the expression of physiological, morphological and behavioural traits during reproduction and many of these traits are under sexual selection. However, only few studies so far have examined if individual variation in testosterone is correlated with reproductive success. Because socially monogamous bird species pass through different phases within a breeding cycle and each of these phases requires the expression of different behaviours, the relation between testosterone and reproductive success could vary with breeding stage. Here we investigate the link between reproductive success and testosterone in European stonechats – a socially monogamous songbird with biparental care. Previous studies found that territorial aggression in breeding stonechats depends on testosterone and that testosterone levels peak during the mating phase. Thus, high testosterone levels during mating may influence reproductive success by promoting territorial aggression and mate guarding. We found that males with two breeding attempts produced a similar number of fledglings as males with three breeding attempts. However, males with two breeding attempts expressed higher levels of testosterone than males with just one or those with three breeding attempts, regardless of whether testosterone was measured during the mating or the parental phase of the first brood. Furthermore, testosterone levels during mating, but not during parenting correlated with the total annual number of fledglings. Thus, individual variation in levels of plasma testosterone predicted reproductive success in stonechats.

  10. New techniques for experimental generation of two-dimensional blade-vortex interaction at low Reynolds numbers

    Science.gov (United States)

    Booth, E., Jr.; Yu, J. C.

    1986-01-01

    An experimental investigation of two dimensional blade vortex interaction was held at NASA Langley Research Center. The first phase was a flow visualization study to document the approach process of a two dimensional vortex as it encountered a loaded blade model. To accomplish the flow visualization study, a method for generating two dimensional vortex filaments was required. The numerical study used to define a new vortex generation process and the use of this process in the flow visualization study were documented. Additionally, photographic techniques and data analysis methods used in the flow visualization study are examined.

  11. Training reproductive health professionals in a post-conflict environment: exploring medical, nursing, and midwifery education in Mogadishu, Somalia.

    Science.gov (United States)

    Yalahow, Abdiasis; Hassan, Mariam; Foster, Angel M

    2017-11-01

    Following two decades of civil war, Somalia recently entered the post-conflict rebuilding phase that has resulted in the rapid proliferation of higher education institutions. Given the high maternal mortality ratio, the federal government has identified the reproductive health education of health service professionals as a priority. Yet little is known about the coverage of contraception, abortion, pregnancy, childbirth, and sexual and gender-based violence (SGBV) in medicine, nursing, or midwifery. In 2016, we conducted a multi-methods study to understand the reproductive health education and training landscape and identify avenues by which development of the next generation of health service professionals could be improved. Our study comprised two components: interviews with 20 key informants and 7 focus group discussions (FGDs) with 48 physicians, nurses, midwives, and medical students. Using the transcripts, memos, and field notes, we employed a multi-phased approach to analyse our data for content and themes. Our findings show that reproductive health education for medical and nursing students is inconsistent and significant content gaps, particularly in abortion and SGBV, exist. Students have few clinical training opportunities and the overarching challenges plaguing higher education in Somalia also impact health professions programmes in Mogadishu. There is currently a window of opportunity to develop creative strategies to improve the breadth and depth of evidence-based education and training, and multi-stakeholder engagement and the promotion of South-South exchanges appear warranted.

  12. Reproductive and neurobehavioural toxicity study of tartrazine administered to mice in the diet.

    Science.gov (United States)

    Tanaka, Toyohito

    2006-02-01

    Tartrazine was given in the diet to provide levels of 0% (control), 0.05%, 0.15%, and 0.45% (approximately 83, 259, 773 mg/kg/day, respectively) from five weeks of age of the F0 generation to nine weeks of age of the F1 generation in mice, and selected reproductive and neurobehavioural parameters were measured. In movement activity of exploratory behaviour in the F0 generation, number of vertical activity was significantly increased in the middle-dose group in males. There were no adverse effects of tartrazine on either litter size, litter weight and sex ratio at birth. The average body weight of male offspring was significantly increased in the high-dose group and that of female offspring was significantly increased in the middle-dose group at birth. In behavioural developmental parameters, surface righting at PND 4 was significantly accelerated in the high-dose group in male offspring, and those effects were significantly dose-related in a trend test (Ptartrazine in the present study produced a few adverse effects in neurobehavioural parameters during the lactation period in mice. Nevertheless, the high-dose level were in excess of the ADI of tartrazine (0-7.5 mg/kgbw), and the actual dietary intake of tartrazine is presumed to be much lower. It would therefore appear that the levels of actual dietary intake of tartrazine is unlikely to produce any adverse effects in humans.

  13. Conspecific reproductive success and breeding habitat selection: Implications for the study of coloniality

    Science.gov (United States)

    Danchin, E.; Boulinier, T.; Massot, M.

    1998-01-01

    Habitat selection is a crucial process in the life cycle of animals because it can affect most components of fitness. It has been proposed that some animals cue on the reproductive success of conspecifics to select breeding habitats. We tested this hypothesis with demographic and behavioral data from a 17-yr study of the Black-legged Kittiwake (Rissa tridactyla), a cliff-nesting seabird. As the hypothesis assumes, the Black-legged Kittiwake nesting environment was patchy, and the relative quality of the different patches (i.e., breeding cliffs) varied in time. The average reproductive success of the breeders of a given cliff was predictable from one year to the next, but this predictability faded after several years. The dynamic nature of cliff quality in the long term is partly explained by the autocorrelation of the prevalence of an ectoparasite that influences reproductive success. As predicted by the performance-based conspecific attraction hypothesis, the reproductive success of current breeders on a given cliff was predictive of the reproductive success of new recruits on the cliff in the following year. Breeders tended to recruit to the previous year's most productive cliffs and to emigrate from the least productive ones. Consequently, the dynamics of breeder numbers on the cliffs were explained by local reproductive success on a year-to-year basis. Because, on average, young Black-legged Kittiwakes first breed when 4 yr old, such a relationship probably results from individual choices based on the assessment of previous-year local quality. When breeders changed breeding cliffs between years, they selected cliffs of per capita higher reproductive success. Furthermore, after accounting for the potential effects of age and sex as well as between-year variations, the effect of individual breeding performance on breeding dispersal was strongly influenced by the average reproductive success of other breeders on the same cliff. Individual breeding performance did

  14. Progeny reproduction

    International Nuclear Information System (INIS)

    Mashneva, N.I.

    1984-01-01

    Studies on clarification of importance of different harmful factors of radiation and chemical nature on the function of progeny reproduction, growth and development are presented. Intake of radionuclides to organism, of white mices and rats in concentrations corresponding to 10 6 PCsub(s) ( 90 Sr, 210 Po, 210 Pb and other) is shown to result in 100% sterility of females, 10 5 -10 4 PCsub(s) concentrations cause damaging effect of different degrees of expression at later stages of effect. Smaller contents of radionuclides (10 3 -10 2 PCsub(s)) did not result in noticeable changes in reproductivity of animals. Similar regularities were observed under effect of different concentrations of chemical agent. Some peculiarities of animal physiology should be taken into account to obtain data of estimation of damaging effect of harmful factors on reproduction function

  15. Heparin for assisted reproduction.

    Science.gov (United States)

    Akhtar, Muhammad A; Sur, Shyamaly; Raine-Fenning, Nick; Jayaprakasan, Kannamannadiar; Thornton, Jim G; Quenby, Siobhan

    2013-08-17

    Heparin as an adjunct in assisted reproduction (peri-implantation heparin) is given at or after egg collection or at embryo transfer during assisted reproduction. Heparin has been advocated to improve embryo implantation and clinical outcomes.  It has been proposed that heparin enhances the intra-uterine environment by improving decidualisation with an associated activation of growth factors and a cytokine expression profile in the endometrium that is favourable to pregnancy. To investigate whether the administration of heparin around the time of implantation (peri-implantation heparin) improves clinical outcomes in subfertile women undergoing assisted reproduction. A comprehensive and exhaustive search strategy was developed in consultation with the Trials Search Co-ordinator of the Cochrane Menstrual Disorders and Subfertility Group (MDSG). The strategy was used in an attempt to identify all relevant studies regardless of language or publication status (published, unpublished, in press, and in progress). Relevant trials were identified from both electronic databases and other resources (last search 6 May 2013). All randomised controlled trials (RCTs) were included where peri-implantation heparin was given during assisted reproduction. Peri-implantation low molecular weight heparin (LMWH) during IVF/ICSI was given at or after egg collection or at embryo transfer in the included studies. Live birth rate was the primary outcome. Two review authors independently assessed the eligibility and quality of trials and extracted relevant data. The quality of the evidence was evaluated using GRADE methods. Three RCTs (involving 386 women) were included in the review.Peri-implantation LMWH administration during assisted reproduction was associated with a significant improvement in live birth rate compared with placebo or no LMWH (odds ratio (OR) 1.77, 95% confidence interval (CI) 1.07 to 2.90, three studies, 386 women, I(2) = 51%, very low quality evidence with high

  16. How cushion communities are maintained in alpine ecosystems: A review and case study on alpine cushion plant reproduction

    Directory of Open Access Journals (Sweden)

    Jianguo Chen

    2017-08-01

    Full Text Available Cushion species occur in nearly all alpine environments worldwide. In past decades, the adaptive and ecosystem-engineering roles of such highly specialized life forms have been well studied. However, the adaptive strategies responsible for cushion species reproductive success and maintenance in severe alpine habitats remain largely unclear. In this study, we reviewed the current understanding of reproductive strategies and population persistence in alpine cushion species. We then present a preliminary case study on the sexual reproduction of Arenaria polytrichoides (Caryophyllaceae, a typical cushion species inhabiting high elevations of the Himalaya Hengduan Mountains, which is a hotspot for diversification of cushion species. Finally, we highlight the limitations of our current understanding of alpine cushion species reproduction and propose future directions for study.

  17. Pulsed Power Generators For Two-section Lia Relativistic Magnetron Driver

    CERN Document Server

    Agafonov, A V; Pevchev, V P

    2004-01-01

    Two prototypes of pulsed power generators for a two-sectional LIA - specialized driver of a relativistic magnetron were constructed and tested. The driver for the double-sided powering of a relativistic magnetron consists of two identical sets of induction modules (two sections of LIA) with inner electrodes - vacuum adders connected to both sides of a coaxial magnetron. It provides the symmetric power flowing in a magnetron and a possibility of localising of the electron flow in magnetron interaction region. The first generator designed for a small-scale laboratory installation provides the output pulses of 100 ns in duration with voltage amplitude of 50 kV at repetition rate of 1 pps. The construction of the generator is based on the application of experimental capacitor banks designed as a pulse forming line with the next parameters: charging voltage - 80 kV, impedance - 1,7 Ohm, pulse duration - 80 ns at a matched load. The second generator was designed for 1 MV integrated LIA - magnetron system. It cons...

  18. Differentials in reproductive and child health status in India

    Directory of Open Access Journals (Sweden)

    Nikhilesh Parchure

    2011-12-01

    Full Text Available

    Background: Inequalities in reproductive and child health (RCH exist, in general, in different regions of India. The present study aims to investigate the current status of RCH and examine the factors responsible for it in different parts of India.

    Methods: This study utilized data obtained from two Indian studies – (i National Family Health Survey – 3 (NFHS- 2005-06 and (ii District Level Household Survey (DLHS – 2002-04. Reproductive Health Index was computed on the basis of five variables such as total fertility rate, infant mortality rate, birth order, delivery care and female educational attainment.

    Results: In terms of reproductive and child health, a wide range of variation exists in India in its different regions. The study reveals that among Indian states, 13 states have an index value less than the national average. On the basis of the reproductive health index, the Indian states can be divided into three categories, namely; progressive states, semi progressive states and backward states.

    Conclusions: The interstate differences in healthcare utilization are partly due to variations in the implementation of maternal health care programs as well as differences in availability of and accessibility to healthcare between Indian states.

  19. Reproductive Rights or Reproductive Justice? Lessons from Argentina.

    Science.gov (United States)

    Morgan, Lynn

    2015-06-11

    Argentine sexual and reproductive rights activists insist on using the language and framework of "human rights," even when many reproductive rights activists in the US and elsewhere now prefer the framework of "reproductive justice." Reflecting on conversations with Argentine feminist anthropologists, social scientists, and reproductive rights activists, this paper analyzes why the Argentine movement to legalize abortion relies on the contested concept of human rights. Its conclusion that "women's rights are human rights" is a powerful claim in post-dictatorship politics where abortion is not yet legal and the full scope of women's rights has yet to be included in the government's human rights agenda. Argentine feminist human rights activists have long been attentive to the ways that social class, gender, migration, and racism intersect with reproduction. Because their government respects and responds to a human rights framework, however, they have not felt it necessary--as U.S. feminists have--to invent a new notion of reproductive justice in order to be heard. Given the increasing popularity of reproductive justice in health and human rights, the Argentine case shows that rights-based claims can still be politically useful when a State values the concept of human rights. Copyright 2015 Morgan. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited.

  20. A Mission Concept to Study Multigenerational Mammalian Reproduction in Partial Gravity

    Science.gov (United States)

    Rodgers, Erica M.; Simon, Matthew A.; Chai, Patrick R.; Neilan, James H.; Stillwagen, Fred H.; Williams, Phillip A.; Lewis, Weston

    2016-01-01

    A team at NASA Langley Research Center conducted a study during which a conceptual space mission was designed. In this study, rodents are used as human analogs to gather biological and systems data in a relevant environment applicable to future settlements on Mars. The mission concept uniquely addresses the combined effects of long-durations (one-year or greater), autonomous and robotic operations, and biological responses to partial gravity with an emphasis on reproduction. The objectives of this study were to 1) understand challenges associated with designing an artificial gravity habitat that supports the reproduction and maturation of a large animal colony, 2) identify mission architectures and operational concepts to transport and maintain such a facility, and 3) identify fundamental science considerations for mammalian reproduction studies to inform vehicle design. A model demonstration unit was developed to visualize and test certain design concepts that resulted from these considerations. Three versions of this demonstration unit were built over the course of the study, each taking into account lessons learned from the previous version. This paper presents the updated baseline mission and spacecraft design concepts to achieve these objectives, with a specific emphasis on updates since publication in previous works. Analyses of the integrated system trades among the elements which make up the conceptual vehicle are described to address overall feasibility and identify potential integrated design opportunities. The latest iteration of the habitat robotics design and a conceptual design example for autonomous care of crew and systems are also presented. Finally, the conclusion of this conceptual design study, necessary future analyses to enable such a facility, and comments upon other applications of a similar exploration-focused research facilities are addressed.

  1. Genetic diversity and reproductive success in mandrills (Mandrillus sphinx).

    Science.gov (United States)

    Charpentier, M; Setchell, J M; Prugnolle, F; Knapp, L A; Wickings, E J; Peignot, P; Hossaert-McKey, M

    2005-11-15

    Recent studies of wild animal populations have shown that estimators of neutral genetic diversity, such as mean heterozygosity, are often correlated with various fitness traits, such as survival, disease susceptibility, or reproductive success. We used two estimators of genetic diversity to explore the relationship between heterozygosity and reproductive success in male and female mandrills (Mandrillus sphinx) living in a semifree ranging setting in Gabon. Because social rank is known to influence reproductive success in both sexes, we also examined the correlation between genetic diversity and social rank in females, and acquisition of alpha status in males, as well as length of alpha male tenure. We found that heterozygous individuals showed greater reproductive success, with both females and males producing more offspring. However, heterozygosity influenced reproductive success only in dominant males, not in subordinates. Neither the acquisition of alpha status in males, nor social rank in females, was significantly correlated with heterozygosity, although more heterozygous alpha males showed longer tenure than homozygous ones. We also tested whether the benefits of greater genetic diversity were due mainly to a genome-wide effect of inbreeding depression or to heterosis at one or a few loci. Multilocus effects best explained the correlation between heterozygosity and reproductive success and tenure, indicating the occurrence of inbreeding depression in this mandrill colony.

  2. Study on reproductive endocrinological function in postmenopausal women treated with estriol

    International Nuclear Information System (INIS)

    Li Wenqi; Zhou Zhenli; Zhou Jiwen; Li Xin

    2002-01-01

    Objective: To investigate the reproductive endocrinological function in postmenopausal women treated with ultralente estriol for 3 years. Methods: Serum levels of six reproductive hormones (FSH, LH, PRL, T, E 2 , P) were measured with RIA in 1) 136 normal 1-5yrs post-menopausal women 2) 48 post-menopausal women treated with estriol for 3 years 3) 131 healthy women of child-bearing age during follicular and luteal phases. Results: Serum levels of the six reproductive hormones in women of child-bearing age at both follicular and luteal phases were significantly different from those in post-menopausal women (p 2 , P and T levels were not significant (p > 0.05). Conclusion: Serum reproductive hormones assay is important for monitoring hormone replacement therapy in aging women

  3. Reproductive decisions in the lives of West Bank Palestinian women: Dimensions and contradictions.

    Science.gov (United States)

    Pell, Stephanie

    2017-02-01

    Palestinian women have one of the highest fertility rates in the world, averaging 4.38 births per woman. However, Palestinian fertility patterns are distinct from those of other developing nations, in that high fertility rates coexist alongside high levels of education and low levels of infant mortality - both of which have been established elsewhere as predictors of low total fertility rates. This study explores the dimensions and context of the contradictions between fertility predictors and rates, isolating main factors that shape Palestinian reproductive behaviour. Furthermore, while this study addresses factors that influence the high fertility in the Palestinian Territories, it also addresses factors that contribute to the steady decline of this trend. In-depth interviews were conducted with Palestinian women in urban refugee communities and key informant interviews with experts on Palestinian reproductive health. The findings indicate that five factors shape women's reproductive behaviour: (1) the fear of losing one's children in the ongoing conflict; (2) socio-economic factors including poverty and density of space; (3) the marital relationship; (4) religious values; and (5) generational differences. These results highlight the influence of socio-political conditions on reproductive behaviour and the significance of women's agency in manoeuvring their fertility outcomes.

  4. Reproductive efficiency of captive Chinese- and Indian-origin rhesus macaque (Macaca mulatta) females

    Science.gov (United States)

    Kubisch, H. Michael; Falkenstein, Kathrine P.; Deroche, Chelsea B.; Franke, Donald E.

    2011-01-01

    Reproductive and survival records (n = 2,913) from 313 Chinese-origin and 365 Indian-derived rhesus macaques at the Tulane National Primate Research Center spanning 3 generations were studied. Least-squares analysis of variance procedures were used to compare reproductive and infant survival traits while proportional hazards regression procedures were used to study female age at death, number of infants born per female and time from last birth to death. Chinese females were older at first parturition than Indian-females because they were older when placed with males, but the two subspecies had similar first and lifetime post-partum birth intervals. Females that gave birth to stillborn infants had shorter first post-partum birth intervals than females giving birth to live infants. Post-partum birth intervals decreased in females from 3 to 12 years of age but then increased again with advancing age. Chinese infants had a greater survival rate than Indian infants at 30 d, 6 mo and 1yr of age. Five hundred and forty-three females (80.01 %) had uncensored, or true records for age at death, number of infants born per female, and time from the birth until death whereas 135 females (19.91 %) had censored records for these traits. Low and high uncensored observations for age at death were 3 and 26 years of age for Chinese and 3 and 23 years of age for Indian females. Uncensored number of infants born per female ranged from 1 to 15 for Chinese females and 1 to 18 for Indian females. Each of these traits was significantly influenced by the origin × generation interaction in the proportional hazards regression analyses, indicating that probabilities associated with age at death, number of infants born per female and time from last birth to death for Chinese and Indian females did not rank the same across generations. PMID:22512021

  5. Identifying the dominating perceptual differences in headphone reproduction

    DEFF Research Database (Denmark)

    Volk, Christer Peter; Lavandier, Mathieu; Bech, Søren

    2016-01-01

    The perceptual differences between the sound reproductions of headphones were investigated in a pair-wise comparison study. Two musical excerpts were reproduced over 21 headphones positioned on a mannequin and recorded. The recordings were then processed and reproduced over one set of headphones ...

  6. Comparison of two oestrus synchronisation protocols administered to dairy cows during routine reproduction services

    DEFF Research Database (Denmark)

    Viora, L; Denwood, M; Ellis, K

    2015-01-01

    Progesterone-based oestrus synchronisation protocols are frequently used for treatment of cows presented for examination during routine reproduction management service. This study aimed to evaluate the effect of the addition of gonadotrophin-releasing hormone (GnRH) at the start of a progesterone......-based oestrus synchronisation protocol for cows presented for examination during routine veterinary service on a commercial dairy farm over 10 months. Overall 139 animals were retained in the study, of which 78 received a standard progesterone-based treatment (STD) and 61 received the same treatment...

  7. Reproductive performances of Boe, Kacang and Boerka does

    Directory of Open Access Journals (Sweden)

    Simon Elieser

    2012-06-01

    Full Text Available Does reproduction performance could be expressed by her ability to give birth and to give milk to their kids during the pre-weaning period. This study was aimed to evaluate the reproductive performance of Boer, Kacang and Boerka does; and was carried out for two years at Research Institute for Goat Production, Sungei Putih. The materials used were goats owned by the institute. The parameters observed were: litter size, parity of does, preweaning mortality, kidding interval and sex ratio of kids. The rate of reproduction of the does was estimated using Amir and Knipscheer methods and were statistically analyzed using General linear model. Results showed that litter size and kidding interval of Boer goats were higher (P < 0.05 then that of Kacang goats, while the Boerka goats was in between. The mortality at preweaning of Boer goats was lower (P < 0.05 then that of Kacang goats, while the Boerka goats was in between. The percentage of kid sex ratio of three breeds were fluctuated. Parity of does had significant effect on all reproduction traits (P < 0.05 except for sex ratio of kids. The does reproduction was smallest at the first parity, and increased with the increase of parity from one to four, and then decreased in subsequent parities. The highest does reproduction rate was found in the Boerka (1.82, followed by Boer (1.80 and Kacang (1.80. It is concluded that the reproductive performance of the three breed female goat was relatively the same.

  8. Relationship satisfaction in lesbian and heterosexual couples before and after assisted reproduction: a longitudinal follow-up study.

    Science.gov (United States)

    Borneskog, Catrin; Lampic, Claudia; Sydsjö, Gunilla; Bladh, Marie; Svanberg, Agneta Skoog

    2014-12-12

    More and more lesbian couples are planning parenthood through donor insemination and IVF and the number of planned lesbian families is growing in Sweden and other western countries. Research has shown that lesbian couples report as much overall satisfaction in their relationships as do heterosexual couples. However, although parenthood is highly desired, many parents are unaware of the demands of parenthood and the strain on their relationship that the arrival of the baby might bring. The aim of this study was to compare lesbian and heterosexual couples' perceptions of relationship satisfaction at a three-year follow up after assisted reproduction. The present study is a part of the Swedish study on gamete donation, a prospective longitudinal cohort study. The present study constitutes a three-year follow up assessment of lesbian and heterosexual couples after assisted reproduction. Participants requesting assisted reproduction at all fertility clinics performing gamete donation in Sweden, were recruited consecutively during 2005-2008. A total of 114 lesbian women (57 treated women and 57 partners) and 126 heterosexual women and men (63 women and 63 men) participated. Participants responded to the ENRICH inventory at two time points during 2005-2011; at the commencement of treatment (time point 1) and about three years after treatment termination (time point 3). To evaluate the bivariate relationships between the groups (heterosexual and lesbian) and socio-demographic factors Pearson's Chi- square test was used. Kolmogorov-Smirnov test was used for testing of normality, Mann-Whitney U- test to examine differences in ENRICH between the groups and paired samples t-test to examine scores over time. Lesbian couples reported higher relationship satisfaction than heterosexual couples, however the heterosexual couples satisfaction with relationship quality was not low. Both lesbian and heterosexual couples would be classified accordingly to ENRICH-typology as vitalized or

  9. Circadian rhythms and reproduction.

    Science.gov (United States)

    Boden, Michael J; Kennaway, David J

    2006-09-01

    There is a growing recognition that the circadian timing system, in particular recently discovered clock genes, plays a major role in a wide range of physiological systems. Microarray studies, for example, have shown that the expression of hundreds of genes changes many fold in the suprachiasmatic nucleus, liver heart and kidney. In this review, we discuss the role of circadian rhythmicity in the control of reproductive function in animals and humans. Circadian rhythms and clock genes appear to be involved in optimal reproductive performance, but there are sufficient redundancies in their function that many of the knockout mice produced do not show overt reproductive failure. Furthermore, important strain differences have emerged from the studies especially between the various Clock (Circadian Locomotor Output Cycle Kaput) mutant strains. Nevertheless, there is emerging evidence that the primary clock genes, Clock and Bmal1 (Brain and Muscle ARNT-like protein 1, also known as Mop3), strongly influence reproductive competency. The extent to which the circadian timing system affects human reproductive performance is not known, in part, because many of the appropriate studies have not been done. With the role of Clock and Bmal1 in fertility becoming clearer, it may be time to pursue the effect of polymorphisms in these genes in relation to the various types of infertility in humans.

  10. [Sublethal effects of spinetoram and azadirachtin on development and reproduction of Frankliniella occidentalis (Pergande).

    Science.gov (United States)

    Yang, Guang Ming; Zhi, Jun Rui; Li, Shun Xin; Liu, Li

    2016-11-18

    To evaluate the sublethal effects of spinetoram and azadirachtin on western flower thrips, Frankliniella occidentalis, leaf dipping method was used to determine their sublethal concentrations (LC 25 ) on the 2 nd instar nymph, and their influences on development and reproduction of F. occidentalis were studied. The results showed exposure of sublethal concentrations of spinetoram and azadirachtin to F. accidentalis had different degrees of effects on this insect pest. Under bisexual reproduction, the LC 25 spinetoram had no significant influences on pre-oviposition period, female adult longevity and fecundity, but male adult longevity was significantly shorter than the control. The LC 25 azadirachtin significantly reduced fecundity and prolonged pre-oviposition period. Under parthenogenesis, the LC 25 spinetoram and azadirachtin extended the pre-oviposition duration, whereas the LC 25 azadirachtin shortened the female adult longevity and significantly decreased fecundity. The LC 25 spinetoram and azadirachtin had different influences on developmental duration of each stage of next generation. The immature stage in treatment group of the LC 25 spinetoram was shorter than that in treatment group of the LC 25 azadirachtin, under bisexual reproduction or parthenogenesis. Intrinsic rate of increase (r m ) and finite rate of increase (λ) of population treated by the LC 25 spinetoram were higher than those of the control, whereas the r m , R 0 , and λ of population treated by the LC 25 azadirachtin were lower than those of the control. The findings indicated that the effects of the LC 25 spinetoram and azadirachtin on the development and reproduction of F. accidentalis were different. The LC 25 spinetoram had certain stimulating effect, whereas the LC 25 azadirach-tinon had significant inhibitory effect. Two biopesticides' influences were related with the reproductive patterns of F. accidentalis.

  11. Entangled Coherent States Generation in two Superconducting LC Circuits

    International Nuclear Information System (INIS)

    Chen Meiyu; Zhang Weimin

    2008-01-01

    We proposed a novel pure electronic (solid state) device consisting of two superconducting LC circuits coupled to a superconducting flux qubit. The entangled coherent states of the two LC modes is generated through the measurement of the flux qubit states. The interaction of the flux qubit and two LC circuits is controlled by the external microwave control lines. The geometrical structure of the LC circuits is adjustable and makes a strong coupling between them achievable. This entangled coherent state generator can be realized by using the conventional microelectronic fabrication techniques which increases the feasibility of the experiment.

  12. What women want from women's reproductive health research: a qualitative study.

    Science.gov (United States)

    Pandey, Shilpi; Porter, Maureen; Bhattacharya, Siladitya

    2015-12-01

    Researchers are being urged to involve patients in the design and conduct of studies in health care with limited insight at present into their needs, abilities or interests. This is particularly true in the field of reproductive health care where many conditions such as pregnancy, menopause and fertility problems involve women who are otherwise healthy. To ascertain the feasibility of involving patients and members of the public in research on women's reproductive health care (WRH). University and tertiary care hospital in north-east Scotland; 37 women aged 18-57. Four focus groups and one individual interview were audio-recorded and verbatim transcripts analysed thematically by two researchers using a grounded theory approach. Most participants were interested in WRH, but some participated to promote a health issue of special concern to them. Priorities for research reflected women's personal concerns: endometriosis, polycystic ovary syndrome, menopause, fertility risks of delaying parenthood and early post-natal discharge from hospital. Women were initially enthusiastic about getting involved in research on WRH at the design or delivery stage, but after discussion in focus groups, some questioned their ability to do so or the time available to commit to research. None of the respondents expected payment for any involvement, believing that the experience would be rewarding enough in itself. Involving patients and public in research would include different perspectives and priorities; however, recruiting for this purpose would be challenging. © 2014 John Wiley & Sons Ltd.

  13. Developmental programming: deficits in reproductive hormone dynamics and ovulatory outcomes in prenatal, testosterone-treated sheep.

    Science.gov (United States)

    Veiga-Lopez, A; Ye, W; Phillips, D J; Herkimer, C; Knight, P G; Padmanabhan, V

    2008-04-01

    Prenatal testosterone excess leads to neuroendocrine, ovarian, and metabolic disruptions, culminating in reproductive phenotypes mimicking that of women with polycystic ovary syndrome (PCOS). The objective of this study was to determine the consequences of prenatal testosterone treatment on periovulatory hormonal dynamics and ovulatory outcomes. To generate prenatal testosterone-treated females, pregnant sheep were injected intramuscularly (days 30-90 of gestation, term=147 days) with 100 mg of testosterone-propionate in cottonseed oil semi-weekly. Female offspring born to untreated control females and prenatal testosterone-treated females were then studied during their first two breeding seasons. Sheep were given two injections of prostaglandin F2alpha 11 days apart, and blood samples were collected at 2-h intervals for 120 h, 10-min intervals for 8 h during the luteal phase (first breeding season only), and daily for an additional 15 days to characterize changes in reproductive hormonal dynamics. During the first breeding season, prenatal testosterone-treated females manifested disruptions in the timing and magnitude of primary gonadotropin surges, luteal defects, and reduced responsiveness to progesterone negative feedback. Disruptions in the periovulatory sequence of events during the second breeding season included: 1) delayed but increased preovulatory estradiol rise, 2) delayed and severely reduced primary gonadotropin surge in prenatal testosterone-treated females having an LH surge, 3) tendency for an amplified secondary FSH surge and a shift in the relative balance of FSH regulatory proteins, and 4) luteal responses that ranged from normal to anovulatory. These outcomes are likely to be of relevance to developmental origin of infertility disorders and suggest that differences in fetal exposure or fetal susceptibility to testosterone may account for the variability in reproductive phenotypes.

  14. Visual communication stimulates reproduction in Nile tilapia, Oreochromis niloticus (L.

    Directory of Open Access Journals (Sweden)

    A.L.S. Castro

    2009-04-01

    Full Text Available Reproductive fish behavior is affected by male-female interactions that stimulate physiological responses such as hormonal release and gonad development. During male-female interactions, visual and chemical communication can modulate fish reproduction. The aim of the present study was to test the effect of visual and chemical male-female interaction on the gonad development and reproductive behavior of the cichlid fish Nile tilapia, Oreochromis niloticus (L.. Fifty-six pairs were studied after being maintained for 5 days under one of the four conditions (N = 14 for each condition: 1 visual contact (V; 2 chemical contact (Ch; 3 chemical and visual contact (Ch+V; 4 no sensory contact (Iso - males and females isolated. We compared the reproductive behavior (nesting, courtship and spawning and gonadosomatic index (GSI of pairs of fish under all four conditions. Visual communication enhanced the frequency of courtship in males (mean ± SEM; V: 24.79 ± 3.30, Ch+V: 20.74 ± 3.09, Ch: 0.1 ± 0.07, Iso: 4.68 ± 1.26 events/30 min; P < 0.05, two-way ANOVA with LSD post hoc test, induced spawning in females (3 spawning in V and also 3 in Ch+V condition, and increased GSI in males (mean ± SEM; V: 1.39 ± 0.08, Ch+V: 1.21 ± 0.08, Ch: 1.04 ± 0.07, Iso: 0.82 ± 0.07%; P < 0.05, two-way ANOVA with LSD post hoc test. Chemical communication did not affect the reproductive behavior of pairs nor did it enhance the effects of visual contact. Therefore, male-female visual communication is an effective cue, which stimulates reproduction among pairs of Nile tilapia.

  15. The effects of radiation on the biology and reproduction of Helicoverpa armigera (Lepidoptera: Noctuidae)

    International Nuclear Information System (INIS)

    Ramos Ocampo, V.; Leon, J.B. de

    2002-01-01

    The effect of irradiating male Helicoverpa armigera with a substerilizing dose (100 Gy) of gamma radiation on the growth, development and reproduction of subsequent generations was studied in the laboratory. This dose of gamma radiation had no significant detrimental effects on larval and pupal weights or on the duration of the pupal period in the F 1 progeny. However, it lengthened the duration of the larval period by two days. In the F 2 generation, the progeny of the Tf 1 FxTf 1 M cross had significantly lighter pupae. The effects of this substerilizing dose of radiation and of the resulting inherited sterility on the reproduction of Helicoverpa armigera were similar to those described for other species of Lepidoptera. No detrimental effects on P 1 and F 1 female fecundity were recorded. Crosses involving Tf 1 females laid only about one half the number of eggs laid by the controls, however the range in the number of eggs laid by these females fell within the normal range for Helicoverpa armigera. Fertility of crosses involving P 1 males was greatly affected; fertility in these females was only 61% of that exhibited by the controls. This deleterious effect was inherited in the F 1 and F 2 generations and was maximally expressed when F 1 progeny of the NFxTM cross were inbred. Egg hatch was almost completely inhibited in sibling crosses while outcrosses of the F 1 progeny showed a 64-70% reduction in egg hatch when compared to controls. (author)

  16. Experiencing reproductive concerns as a female cancer survivor is associated with depression.

    Science.gov (United States)

    Gorman, Jessica R; Su, H Irene; Roberts, Samantha C; Dominick, Sally A; Malcarne, Vanessa L

    2015-03-15

    Young adult female cancer survivors have unmet reproductive concerns and informational needs that are associated with poorer quality of life. The purpose of this study was to examine the association between current reproductive concerns and moderate to severe depression among young survivors. This cross-sectional study included 200 female cancer survivors between the ages of 18 and 35 years who completed a Web-based survey measuring reproductive history, parenthood desires, reproductive concerns after cancer, and quality-of-life indicators. The mean age of the participants was 28 years (standard deviation, 4.4 years), and almost two-thirds were diagnosed within 5 years of survey completion. A multivariate logistic regression analysis controlling for education, duration of survivorship, and social support revealed an association between experiencing reproductive concerns and moderate to severe depression (odds ratio for each 5-unit increase in the Reproductive Concerns After Cancer [RCAC] score, 1.30; 95% confidence interval, 1.06-1.60). Among those with moderate to severe depression, 23% had high RCAC scores, whereas 6% of those with minimal to mild depression did (P reproductive concerns was associated with greater odds of experiencing moderate to severe depression. Almost a quarter of survivors in this sample reported moderate to severe depression, and addressing reproductive concerns represents one potential area of intervention for improving the psychosocial health of young survivors. © 2014 American Cancer Society.

  17. Coral reproduction in Western Australia

    Science.gov (United States)

    Speed, Conrad W.; Babcock, Russ

    2016-01-01

    Larval production and recruitment underpin the maintenance of coral populations, but these early life history stages are vulnerable to extreme variation in physical conditions. Environmental managers aim to minimise human impacts during significant periods of larval production and recruitment on reefs, but doing so requires knowledge of the modes and timing of coral reproduction. Most corals are hermaphroditic or gonochoric, with a brooding or broadcast spawning mode of reproduction. Brooding corals are a significant component of some reefs and produce larvae over consecutive months. Broadcast spawning corals are more common and display considerable variation in their patterns of spawning among reefs. Highly synchronous spawning can occur on reefs around Australia, particularly on the Great Barrier Reef. On Australia’s remote north-west coast there have been fewer studies of coral reproduction. The recent industrial expansion into these regions has facilitated research, but the associated data are often contained within confidential reports. Here we combine information in this grey-literature with that available publicly to update our knowledge of coral reproduction in WA, for tens of thousands of corals and hundreds of species from over a dozen reefs spanning 20° of latitude. We identified broad patterns in coral reproduction, but more detailed insights were hindered by biased sampling; most studies focused on species of Acropora sampled over a few months at several reefs. Within the existing data, there was a latitudinal gradient in spawning activity among seasons, with mass spawning during autumn occurring on all reefs (but the temperate south-west). Participation in a smaller, multi-specific spawning during spring decreased from approximately one quarter of corals on the Kimberley Oceanic reefs to little participation at Ningaloo. Within these seasons, spawning was concentrated in March and/or April, and October and/or November, depending on the timing of

  18. Effects of fluctuating temperature and food availability on reproduction and lifespan

    OpenAIRE

    Schwartz, Tonia S.; Pearson, Phillip; Dawson, John; Allison, David B.; Gohlke, Julia M.

    2016-01-01

    Experimental studies on energetics and aging often remove two major factors that in part regulate the energy budget in a normal healthy individual: reproduction and fluctuating environmental conditions that challenge homeostasis. Here we use the cyclical parthenogenetic Daphnia pulex to evaluate the role of a fluctuating thermal environment on both reproduction and lifespan across six food concentrations. We test the hypotheses that (1) caloric restriction extends lifespan; (2) maximal reprod...

  19. Assessing toxicant effects in a complex estuary--A case study of effects of silver on reproduction in the bivalve, Potamocurbula amurensis, in San Francisco Bay

    Science.gov (United States)

    Brown, Cynthia L.; Parchaso, Francis; Thompson, Janet K.; Luoma, Samuel N.

    2003-01-01

    Contaminant exposures in natural systems can be highly variable. This variability is superimposed upon cyclic variability in biological processes. Together, these factors can confound determination of contaminant effects. Long term, multidisciplined studies with high frequency sampling can be effective in overcoming such obstacles. While studying trace metal contamination in the tissues of the clam, Potamocorbula amurensis, in the northern reach of San Francisco Bay, an episode of high Ag concentrations was identified (maximum of 5.5 µg g−1) at two mid-estuary sites. High concentrations were not seen in clams up-estuary (maximum of 1.92 µg g−1) from these sites and were reduced down-estuary (maximum of 2.67 µg g−1). Silver is not common naturally in the environment, so its elevated presence is usually indicative of anthropogenic influences such as municipal and industrial discharge. Monthly sampling of reproductive status of clams characterized the reproductive cycle and differences in the patterns of reproductive activity that corresponded to changes in Ag tissue concentrations. The proportion of reproductive clams was less than 60% during periods when tissue concentrations were high (generally >2 µg g−1). When tissue concentrations of Ag decreased (≤1 µg g−1), the proportion of reproductive clams was 80 to 100%. A comparison between the annual proportion of reproductive clams and annual Ag tissue concentrations showed a significant negative correlation. No other measured environmental variables were correlated with reproductive impairment. The weight-of-evidence approach strongly supports a cause and effect relationship between Ag contamination and reduced reproductive activity in P. amurensis.

  20. Assessing toxicant effects in a complex estuary: A case study of effects of silver on reproduction in the bivalve, Potamocorbula amurensis, in San Francisco Bay

    Science.gov (United States)

    Brown, C.L.; Parchaso, F.; Thompson, J.K.; Luoma, S.N.

    2003-01-01

    Contaminant exposures in natural systems can be highly variable. This variability is superimposed upon cyclic variability in biological processes. Together, these factors can confound determination of contaminant effects. Long term, multidisciplined studies with high frequency sampling can be effective in overcoming such obstacles. While studying trace metal contamination in the tissues of the clam, Potamocorbula amurensis, in the northern reach of San Francisco Bay, an episode of high Ag concentrations was identified (maximum of 5.5 ??g g-1) at two mid-estuary sites. High concentrations were not seen in clams up-estuary (maximum of 1.92 ??g g-1) from these sites and were reduced down-estuary (maximum of 2.67 ??g g-1). Silver is not common naturally in the environment, so its elevated presence is usually indicative of anthropogenic influences such as municipal and industrial discharge. Monthly sampling of reproductive status of clams characterized the reproductive cycle and differences in the patterns of reproductive activity that corresponded to changes in Ag tissue concentrations. The proportion of reproductive clams was less than 60% during periods when tissue concentrations were high (generally >2 ??g g-1). When tissue concentrations of Ag decreased (???1 ??g g-1), the proportion of reproductive clams was 80 to 100%. A comparison between the annual proportion of reproductive clams and annual Ag tissue concentrations showed a significant negative correlation. No other measured environmental variables were correlated with reproductive impairment. The weight-of-evidence approach strongly supports a cause and effect relationship between Ag contamination and reduced reproductive activity in P. amurensis.

  1. Pulsed electric field increases reproduction.

    Science.gov (United States)

    Panagopoulos, Dimitris J

    2016-01-01

    Purpose To study the effect of pulsed electric field - applied in corona discharge photography - on Drosophila melanogaster reproduction, possible induction of DNA fragmentation, and morphological alterations in the gonads. Materials and methods Animals were exposed to different field intensities (100, 200, 300, and 400 kV/m) during the first 2-5 days of their adult lives, and the effect on reproductive capacity was assessed. DNA fragmentation during early- and mid-oogenesis was investigated by application of the TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labeling) assay. Sections of follicles after fixation and embedding in resins were observed for possible morphological/developmental abnormalities. Results The field increased reproduction by up to 30% by increasing reproductive capacity in both sexes. The effect increased with increasing field intensities. The rate of increase diminished at the strongest intensities. Slight induction of DNA fragmentation was observed exclusively in the nurse (predominantly) and follicle cells, and exclusively at the two most sensitive developmental stages, i.e., germarium and predominantly stage 7-8. Sections of follicles from exposed females at stages of early and mid-oogennesis other than germarium and stages 7-8 did not reveal abnormalities. Conclusions (1) The specific type of electric field may represent a mild stress factor, inducing DNA fragmentation and cell death in a small percentage of gametes, triggering the reaction of the animal's reproductive system to increase the rate of gametogenesis in order to compensate the loss of a small number of gametes. (2) The nurse cells are the most sensitive from all three types of egg chamber cells. (3) The mid-oogenesis checkpoint (stage 7-8) is more sensitive to this field than the early oogenesis one (germarium) in contrast to microwave exposure. (4) Possible therapeutic applications, or applications in increasing fertility, should be investigated.

  2. Dinosaur Reproduction and Parenting

    Science.gov (United States)

    Horner, John R.

    Non-avian dinosaur reproductive and parenting behaviors were mostly similar to those of extant archosaurs. Non-avian dinosaurs were probably sexually dimorphic and some may have engaged in hierarchical rituals. Non-avian coelurosaurs (e.g. Troodontidae, Oviraptorosauria) had two active oviducts, each of which produced single eggs on a daily or greater time scale. The eggs of non-coelurosaurian dinosaurs (e.g. Ornithischia, Sauropoda) were incubated in soils, whereas the eggs of non-avian coelurosaurs (e.g. Troodon, Oviraptor) were incubated with a combination of soil and direct parental contact. Parental attention to the young was variable, ranging from protection from predators to possible parental feeding of nest-bound hatchlings. Semi-altricial hadrosaur hatchlings exited their respective nests near the time of their first linear doubling. Some reproductive behaviors, once thought exclusive to Aves, arose first in non-avian dinosaurs. The success of the Dinosauria may be related to reproductive strategies.

  3. The Reproduction of Intelligence

    Science.gov (United States)

    Meisenberg, Gerhard

    2010-01-01

    Although a negative relationship between fertility and education has been described consistently in most countries of the world, less is known about the relationship between intelligence and reproductive outcomes. Also the paths through which intelligence influences reproductive outcomes are uncertain. The present study uses the NLSY79 to analyze…

  4. Assisted reproductive technology in Europe, 2004: results generated from European registers by ESHRE

    DEFF Research Database (Denmark)

    Goossens, V.; Ferraretti, A.P.; Bhattacharya, S.

    2008-01-01

    BACKGROUND: European results of assisted reproductive techniques from treatments initiated during 2004 are presented in this eighth report. METHODS: Data were mainly collected from existing national registers. From 29 countries, 785 clinics reported 367,066 treatment cycles including: IVF (114,67...

  5. Introducing reproductive life plan-based information in contraceptive counselling: an RCT.

    Science.gov (United States)

    Stern, J; Larsson, M; Kristiansson, P; Tydén, T

    2013-09-01

    Can reproductive life plan (RLP)-based information in contraceptive counselling before pregnancy increase women's knowledge of reproduction, and of the importance of folic acid intake in particular? The RLP-based information increased women's knowledge of reproduction including knowledge of folic acid intake. Many women have insufficient knowledge of reproduction, including a health-promoting lifestyle prior to conception, and highly educated women in particular postpone childbearing until an age when their fertile capacity has started to decrease. The study was an randomized controlled trial with one intervention group (IG) and two control groups (CG1, CG2). A sample size calculation indicated that 82 women per group would be adequate. Recruitment took place during 3 months in 2012 and 299 women were included. The women were randomized in blocks of three. All groups received standard care (contraceptive counselling, Chlamydia testing, cervical screening). In addition, women in the IG were given oral and written RLP-based information about reproduction. A total of 299 out of 338 (88%) Swedish-speaking women visiting a Student Health Centre were included (mean age 23 years); response rate was 88%. Before the counselling, women in the IG and the CG1 completed a baseline questionnaire, including questions about lifestyle changes in connection to pregnancy planning, family planning intentions and knowledge of reproduction (e.g. the fecundity of an ovum). At follow-up 2 months after inclusion, a structured telephone interview was performed in all groups (n = 262, 88% participation rate). There was no difference between the groups regarding the mean knowledge score at baseline. The IG scored higher at follow-up than at baseline (P scored no differently at follow-up than at baseline. The difference in the knowledge score between the IG and the two CGs was significant (P reproductive age should be drawn with caution. The provision of RLP-based information seems to be a

  6. New approach for the study of mite reproduction: The first transcriptome analysis of a mite, Phytoseiulus persimilis (Acari: Phytoseiidae).

    Science.gov (United States)

    Cabrera, Ana R; Donohue, Kevin V; Khalil, Sayed M S; Scholl, Elizabeth; Opperman, Charles; Sonenshine, Daniel E; Roe, R Michael

    2011-01-01

    Many species of mites and ticks are of agricultural and medical importance. Much can be learned from the study of transcriptomes of acarines which can generate DNA-sequence information of potential target genes for the control of acarine pests. High throughput transcriptome sequencing can also yield sequences of genes critical during physiological processes poorly understood in acarines, i.e., the regulation of female reproduction in mites. The predatory mite, Phytoseiulus persimilis, was selected to conduct a transcriptome analysis using 454 pyrosequencing. The objective of this project was to obtain DNA-sequence information of expressed genes from P. persimilis with special interest in sequences corresponding to vitellogenin (Vg) and the vitellogenin receptor (VgR). These genes are critical to the understanding of vitellogenesis, and they will facilitate the study of the regulation of mite female reproduction. A total of 12,556 contiguous sequences (contigs) were assembled with an average size of 935bp. From these sequences, the putative translated peptides of 11 contigs were similar in amino acid sequences to other arthropod Vgs, while 6 were similar to VgRs. We selected some of these sequences to conduct stage-specific expression studies to further determine their function. 2010 Elsevier Ltd. All rights reserved.

  7. Phytoestrogens alter the reproductive organ development in the mink (Mustela vison)

    International Nuclear Information System (INIS)

    Ryoekkynen, Ari; Nieminen, Petteri; Mustonen, Anne-Mari; Pyykoenen, Teija; Asikainen, Juha; Haenninen, Sari; Mononen, Jaakko; Kukkonen, Jussi V.K.

    2005-01-01

    The aim of the present study was to examine the reproductive effects of two perorally applied phytoestrogens, genistein (8 mg/kg/day) and β-sitosterol (50 mg/kg/day), on the mink (Mustela vison) at human dietary exposure levels. Parental generations were exposed over 9 months to these phytoestrogens and their offspring were exposed via gestation and lactation. Parents and their offspring were sampled 21 days after the birth of the kits. Sex hormone levels, sperm quality, organ weights, and development of the kits were examined. The exposed females were heavier than the control females at the 1st postnatal day (PND). The control kits were heavier than the exposed kits from the 1st to the 21st PND. Phytoestrogens did not affect the organ weights of the adult minks, but the relative testicular weight of the exposed kits was higher than in the control kits. The relative prostate weight was higher and the relative uterine weight lower in the β-sitosterol-exposed kits than in the control kits. Moreover, the plasma dihydrotestosterone levels were lower in the genistein-exposed male kits compared to the control male kits. This study could not explain the mechanisms behind these alterations. The results indicate that perinatal phytoestrogen exposures cause alterations in the weight of the reproductive organs of the mink kits

  8. A Two-Generation Human Capital Approach to Anti-poverty Policy

    Directory of Open Access Journals (Sweden)

    Teresa Eckrich Sommer

    2018-02-01

    Full Text Available We propose a two-generation anti-poverty strategy to improve the economic fortunes of children in the United States. Our policy bridges two traditionally siloed interventions to boost their impacts: Head Start for children and career pathway training offered through community colleges for adults. We expect that an integrated two-generation human capital intervention will produce greater gains than either Head Start or community college alone for developmental and motivational, logistical and financial, social capital, and efficiency reasons. We suggest a competitive grant program to test and evaluate different models using federal dollars. We estimate average benefit-cost ratios across a range of promising career fields of 1.3 within five years and 7.9 within ten years if 10 percent of Head Start parents participate in two-generation programs.

  9. Pesantren dan Upaya Pendidikan Kesehatan Reproduksi Remaja (Pesantren and Adolescent Reproductive Health Education Effort

    Directory of Open Access Journals (Sweden)

    Setia Pranata

    2014-04-01

    Full Text Available Background: Although there was Pesantren Health Post, but the promotion and education of reproductive health did notproceed well. Students at the Pesantren are mostly teenagers, therefore sexuality and reproduction problems in pesantrenhad become potential threats. This study described there productive health education in pesantren, that focused on theeducation system, material, and factors supporting and inhibiting reproductive health education efforts. Methods: This was a qualitative study. The data were collected by means of purposive sampling. The study was conducted at two pesantrens in Sampang, Balikpapan and West Lombok regencies. Data were collected by indepth interviews to managers, teachers and students. Results: This study indicated that reproductive education was not something new to the pesantren. The Classic Buku Kuning had been the reference of reproductive education among santri. The kyai used bandongan teaching methods which tend to be monologue. Further more this method did not employ evaluation system. The large number of santri, the high commitment and responsibility of the manager of pesantren, and the availibility of 24 hours assistance were factors that supported reproductive health education in pesantren. The inhibiting factors were limited understanding of reproductive health issues, lack of transparency of the pesantren community regarding issues that were considered taboo, and limitations of supporting infrastructure. Another aspect was the lack of external support that were relevance to the issue of adolescent reproductive health services. Recomendations: It is recommended to enrich the materials on reproductive health education in pesantren,

  10. Impact of Adult Weight, Density, and Age on Reproduction of Tenebrio molitor (Coleoptera: Tenebrionidae)

    Science.gov (United States)

    The impact of adult weight, age, and density on reproduction of Tenebrio molitor L. (Coleoptera: Tenebrionidae) was studied. The impact of adult weight on reproduction was determined in two ways: 1) counting the daily progeny of individual adult pairs of known weight and analyzing the data with line...

  11. Persistent organic pollutants and male reproductive health

    DEFF Research Database (Denmark)

    Vested, Anne; Giwercman, Aleksander; Bonde, Jens Peter

    2014-01-01

    development. An extensive number of epidemiological studies have addressed the possible effects of exposure to POPs on male reproductive health, but the results are conflicting. Thus far, most studies have focused on investigating exposure and the different reproductive health outcomes during adulthood. Some...... suggested adverse effects of exposure to these compounds on human reproductive health, which, according to the endocrine disrupter hypothesis, are ascribed to the compounds' potential to interfere with endocrine signaling, especially when exposure occurs during certain phases of fetal and childhood...... studies have addressed the potential harmful effects of fetal exposure with respect to malformations at birth and/or reproductive development, whereas only a few studies have been able to evaluate whether intrauterine exposure to POPs has long-term consequences for male reproductive health with measurable...

  12. Differences in productive robustness in rabbits selected for reproductive longevity or litter size

    DEFF Research Database (Denmark)

    Theilgaard, R; Baselga, M; Blas, E

    2009-01-01

    The aim of this work was to evaluate the ability of a line selected for reproductive longevity (LP) to confront productive challenges compared to a line selected during 31 generations for litter size at weaning (V). A total of 133 reproductive rabbit does were used (72 and 61 from LP and V lines,...

  13. Reproductive Disorders and Leptospirosis: A Case Study in a Mixed-Species Farm (Cattle and Swine

    Directory of Open Access Journals (Sweden)

    Marcella Mori

    2017-12-01

    Full Text Available Animal leptospirosis, exempt in rodents, manifests as peculiar biology where the animal can function, simultaneously or not, as a susceptible host or reservoir. In the first case, clinical symptoms are likely. In the second case, infection is subclinical and manifestations are mild or absent. Mild clinical symptoms encompass reproductive failure in production animals for host-adapted Leptospira sp. serovars. This work presents a study on Leptospira sp. infection in a mixed-species (bovine and swine farm with documented reproductive disorders in the cattle unit. A long calving interval (above 450 days was the hallmark observed in cows. Some cows (2/26 tested presented a high titre of antibodies against Leptospira sp. serogroup Sejroe, but the overall within-herd prevalence was low (11.5% and 7.7% for cut-off titres of 1:30 and 1:100, respectively. The in-herd prevalence of leptospirosis in the sow unit (determined for 113/140 animals was high when using a lowered cut-off threshold (32.7% vs. 1.8% for cut-off titre of 1:30 and 1:100, respectively. In this unit, the most prevalent serogroup was Autumnalis. The final diagnostic confirmation of Leptospira sp. maintenance within the farm was obtained through detection by PCR of Leptospira sp. DNA in an aborted swine litter. Despite the fact that a common causative infective agent was diagnosed in both species, the direct link between the two animal units was not found. Factors such as drinking from the same water source and the use of manure prepared with the swine slurry might raise suspicion of a possible cross-contamination between the two units. In conclusion, this work suggests that leptospirosis be included in the differential diagnosis of reproductive disorders and spontaneous abortions in production animals and provides data that justify the use of a lowered threshold cut-off for herd diagnosis.

  14. Common genetic variants are significant risk factors for early menopause: results from the Breakthrough Generations Study.

    Science.gov (United States)

    Murray, Anna; Bennett, Claire E; Perry, John R B; Weedon, Michael N; Jacobs, Patricia A; Morris, Danielle H; Orr, Nicholas; Schoemaker, Minouk J; Jones, Michael; Ashworth, Alan; Swerdlow, Anthony J

    2011-01-01

    Women become infertile approximately 10 years before menopause, and as more women delay childbirth into their 30s, the number of women who experience infertility is likely to increase. Tests that predict the timing of menopause would allow women to make informed reproductive decisions. Current predictors are only effective just prior to menopause, and there are no long-range indicators. Age at menopause and early menopause (EM) are highly heritable, suggesting a genetic aetiology. Recent genome-wide scans have identified four loci associated with variation in the age of normal menopause (40-60 years). We aimed to determine whether theses loci are also risk factors for EM. We tested the four menopause-associated genetic variants in a cohort of approximately 2000 women with menopause≤45 years from the Breakthrough Generations Study (BGS). All four variants significantly increased the odds of having EM. Comparing the 4.5% of individuals with the lowest number of risk alleles (two or three) with the 3.0% with the highest number (eight risk alleles), the odds ratio was 4.1 (95% CI 2.4-7.1, P=4.0×10(-7)). In combination, the four variants discriminated EM cases with a receiver operator characteristic area under the curve of 0.6. Four common genetic variants identified by genome-wide association studies, had a significant impact on the odds of having EM in an independent cohort from the BGS. The discriminative power is still limited, but as more variants are discovered they may be useful for predicting reproductive lifespan.

  15. Study of entropy generation in a slab with non-uniform internal heat generation

    Directory of Open Access Journals (Sweden)

    El Haj Assad Mamdouh

    2013-01-01

    Full Text Available Analysis of entropy generation in a rectangular slab with a nonuniform internal heat generation is presented. Dimensionless local and total entropy generation during steady state heat conduction through the slab are obtained. Two different boundary conditions have been considered in the analysis, the first with asymmetric convection and the second with constant slab surface temperature. Temperature distribution within the slab is obtained analytically. The study investigates the effect of some relevant dimensionless heat transfer parameters on entropy generation. The results show that there exists a minimum local entropy generation but there does not exist a minimum total entropy generation for certain combinations of the heat transfer parameters. The results of calculations are presented graphically.

  16. Use it or lose it: reproductive implications of ecological specialization in a haematophagous ectoparasite.

    Science.gov (United States)

    Arbiv, A; Khokhlova, I S; Ovadia, O; Novoplansky, A; Krasnov, B R

    2012-06-01

    Using experimentally induced disruptive selection, we tested two hypotheses regarding the evolution of specialization in parasites. The 'trade-off' hypothesis suggests that adaptation to a specific host may come at the expense of a reduced performance when exploiting another host. The alternative 'relaxed selection' hypothesis suggests that the ability to exploit a given host would deteriorate when becoming obsolete. Three replicate populations of a flea Xenopsylla ramesis were maintained on each of two rodent hosts, Meriones crassus and Dipodillus dasyurus, for nine generations. Fleas maintained on a specific host species for a few generations substantially decreased their reproductive performance when transferred to an alternative host species, whereas they generally did not increase their performance on their maintenance host. The results support the 'relaxed selection' hypothesis of the evolution of ecological specialization in haematophagous ectoparasites, while suggesting that trade-offs are unlikely drivers of specialization. Further work is needed to study the extent by which the observed specializations are based on epigenetic or genetic modifications. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  17. The impact of parental investment on lifetime reproductive success in Iceland.

    Science.gov (United States)

    Lynch, Robert F; Lynch, Emily C

    2017-01-01

    Demonstrating the impact that parents have on the fitness of their children is a crucial step towards understanding how parental investment has affected human evolution. Parents not only transfer genes to their children, they also influence their environments. By analyzing reproductive patterns within and between different categories of close relatives, this study provides insight into the genetic and environmental effects that parents have on the fitness of their offspring. We use data spanning over two centuries from an exceptionally accurate Icelandic genealogy, Íslendingabók, to analyze the relationship between the fertility rates of close relatives. Also, using genetic data, we determine narrow sense heritability estimates ( h 2 ) to further explore the genetic impact on lifetime reproductive success. Finally, we construct four simulations to model the expected contribution of genes and resources on reproductive success. The relationship between the reproduction of all full sibling pairs was significant and positive across all birth decades ( r  = 0.19) while the reproductive relationship between parents and offspring was often negative across many decades and undetectable overall ( r  = 0.00) (Fig. 1 and Table 1). Meanwhile, genetic data among 8,456 pairs of full siblings revealed a narrow sense heritability estimate ( h 2 ) of 0.00 for lifetime reproductive success. A resources model (following the rule that resources are transmitted from parents to children, distributed equally among siblings, and are the only factor affecting reproductive success) revealed a similar trend: a negative relationship between parent and offspring reproduction ( r  =  - 0.35) but a positive relationship among full siblings ( r  = 0.28). The relationship between parent and offspring lifetime reproductive success (LRS) and full sibling LRS was strongly and positively correlated across time ( r  = 0.799, p  investment has had an important impact on fitness. Overall

  18. Extending two Higgs doublet models for two-loop neutrino mass generation and one-loop neutrinoless double beta decay

    Directory of Open Access Journals (Sweden)

    Zhen Liu

    2017-02-01

    Full Text Available We extend some two Higgs doublet models, where the Yukawa couplings for the charged fermion mass generation only involve one Higgs doublet, by two singlet scalars respectively carrying a singly electric charge and a doubly electric charge. The doublet and singlet scalars together can mediate a two-loop diagram to generate a tiny Majorana mass matrix of the standard model neutrinos. Remarkably, the structure of the neutrino mass matrix is fully determined by the symmetric Yukawa couplings of the doubly charged scalar to the right-handed leptons. Meanwhile, a one-loop induced neutrinoless double beta decay can arrive at a testable level even if the electron neutrino has an extremely small Majorana mass. We also study other experimental constraints and implications including some rare processes and Higgs phenomenology.

  19. Extending two Higgs doublet models for two-loop neutrino mass generation and one-loop neutrinoless double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhen, E-mail: liu-zhen@sjtu.edu.cn; Gu, Pei-Hong, E-mail: peihong.gu@sjtu.edu.cn

    2017-02-15

    We extend some two Higgs doublet models, where the Yukawa couplings for the charged fermion mass generation only involve one Higgs doublet, by two singlet scalars respectively carrying a singly electric charge and a doubly electric charge. The doublet and singlet scalars together can mediate a two-loop diagram to generate a tiny Majorana mass matrix of the standard model neutrinos. Remarkably, the structure of the neutrino mass matrix is fully determined by the symmetric Yukawa couplings of the doubly charged scalar to the right-handed leptons. Meanwhile, a one-loop induced neutrinoless double beta decay can arrive at a testable level even if the electron neutrino has an extremely small Majorana mass. We also study other experimental constraints and implications including some rare processes and Higgs phenomenology.

  20. VINCLOZOLIN (V) TREATMENT INDUCES REPRODUCTIVE MALFORMATIONS AND INFERTILITY IN F1 MALE RATS WHEN ADMINISTERED DURING SEXUAL BUT NOT GONADAL DIFFERENTIATION. THE EFFECTS ARE NOT TRANSMITTED TO THE SUBSEQUENT GENERATIONS.

    Science.gov (United States)

    V produces adverse reproductive effects in male rats when administered during sexual differentiation by acting as an androgen-antagonist. It was recently reported that four generations of SD rats, derived from dams dosed via ip injection GD8-15 with 100 mg V/kg/day, displayed pro...

  1. Bibliographical studies concerning reproductive performance of cattle in the tropics

    International Nuclear Information System (INIS)

    Russell, J.M.; Galina, C.S.; Anta, E.; Porras, A.; Zarco, L.

    1990-01-01

    Studies designed to evaluate the publication and research trends of Third World countries in areas related to cattle reproduction in the tropics have shown a marked tendency for publication in such forms as national journals, proceedings, annual reports and theses, which are not readily available for evaluation and assimilation by the scientific community in general. This, coupled with the fact that reports are published preferentially in the native language of the country concerned, contributes to the limited impact of these studies at international level. In addition, research is concentrated on topics which require relatively simple methods important for establishing local reproductive parameters. With regard to the publication output of researchers, it was found that the majority publish only one document, with less than 3% producing more than ten, over a 15 year period. On average, researchers publish over a period of less than five years, indicating a lack of continuity in the research effort in this field. A detailed analysis of the research carried out in Mexico revealed a considerable degree of repetition of studies, as well as the publishing of duplicate results. (author). 14 refs, 1 fig., 4 tabs

  2. Different patterns of oviposition learning in two closely related ectoparasitoid wasps with contrasting reproductive strategies

    Science.gov (United States)

    Sasakawa, Kôji; Uchijima, Kenta; Shibao, Harunobu; Shimada, Masakazu

    2013-02-01

    Many parasitoid wasps learn host-associated cues and use them in subsequent host-searching behavior. This associative learning, namely "oviposition learning," has been investigated in many studies. However, few studies have compared multiple species, and no comparative study has previously been conducted on ectoparasitoid species. We compared the effects of oviposition learning on host preference and offspring sex ratio in two closely related ectoparasitoid wasps with contrasting reproductive strategies, Anisopteromalus calandrae (r-strategist) and its sibling species (K-strategist). Using two bruchine hosts, Callosobruchus chinensis and Callosobruchus maculatus larvae infesting the cowpea Vigna unguiculata, oviposition choice experiments were performed at high and low host densities. In both species, no conspicuous effect on the offspring sex ratio was detected, but effects on host preference were found to differ between the species. In A. calandrae, the effects were detected only at high host density, suggesting that oviposition learning plays a role in host discrimination from a short distance but not from a long distance. In the sibling species, those effects were not detected in any of the cases, suggesting the absence of oviposition learning. These results are compatible with those of previous comparative studies of endoparasitoid wasps in that few lifetime oviposition experiences and/or low reward per foraging decision result in low or absent oviposition learning ability. This finding may indicate that ecological traits contributing to learning ability are similar between endoparasitoid and ectoparasitoid wasps. Thus, our species comparison of ectoparasitoids provides another model system for investigating learning and memory dynamics in parasitoid wasps.

  3. Effect of breeding protocols and reproductive tract score on reproductive performance of dairy heifers and economic outcome of breeding programs.

    Science.gov (United States)

    Stevenson, J L; Rodrigues, J A; Braga, F A; Bitente, S; Dalton, J C; Santos, J E P; Chebel, R C

    2008-09-01

    The objectives of this study were to evaluate the effect of reproductive protocols and reproductive tract score on reproductive performance of dairy heifers and economic outcomes of breeding programs. Holstein heifers (n = 534), 13 +/- 1 mo of age, were randomly assigned to 1 of 4 reproductive protocols. On the day of enrollment (d 0), heifers were palpated per rectum and received a score according to the maturity of their reproductive tract (1 = prepubertal; 2 = peripubertal; and 3 = puber-tal). Estrous detection-control heifers (CON, n = 146) received no treatment and were inseminated on detection of estrus for 28 d. Prostaglandin F(2alpha)-treated heifers (PGED, n = 137) received 1 injection of PGF(2alpha) on d 0 and were inseminated on detection of estrus; heifers not in-seminated by d 14 received a second injection of PGF(2alpha) and were observed for estrus and artificial insemination (AI) for an additional 14 d. Heifers enrolled in the estrous detection-timed AI (EDTAI, n = 140) treatment received a controlled internal drug-release (CIDR) insert on d 0, and 7 d later, the CIDR was removed and all heifers received an injection of PGF(2alpha), heifers received AI on detection of estrus, and those not inseminated by 72 h after PGF(2alpha) received an injection of GnRH concurrent with AI. Heifers in the GnRH-timed AI (GTAI, n = 111) treatment received 1 injection of GnRH on d 0, on d 6 heifers received a CIDR insert and injections of GnRH and PGF(2alpha), on d 13 the CIDR was removed and heifers received an injection of PGF(2alpha), and 48 h later all heifers received an injection of GnRH and AI. Pregnancy was diagnosed at 32 +/- 3 and 62 +/- 3 d after AI. Cost of reproductive protocols and their economic outcomes were calculated for a 28 d period beginning at enrollment. Heifers in the PGED treatment were inseminated at a faster rate than CON heifers. A smaller proportion of prepubertal and peripubertal heifers were inseminated within 14 d of enrollment

  4. Genome-wide association study on reproductive traits in Jinghai Yellow Chicken.

    Science.gov (United States)

    Zhang, G X; Fan, Q C; Wang, J Y; Zhang, T; Xue, Q; Shi, H Q

    2015-12-01

    To identify molecular markers and candidate genes associated with reproductive traits, a genome-wide analysis was performed in Jinghai Yellow Chickens to analyze body weight at first oviposition (BWF), age at first oviposition (AFE), weight of the egg at first oviposition (FEW), egg weight at the age of 300 days (EW300), number of eggs produced by 300 days of age (EN300), egg hatchability (HA) and multiple selection index for egg production (MSI). The results showed that seven single nucleotide polymorphisms (SNPs) were associated with reproductive traits (Preproductive traits were identified (Preproductive traits will greatly advance the understanding of the genetic basis and molecular mechanisms underlying reproductive traits and may have practical significance in breeding programs for the improvements of reproductive traits in the Jinghai Yellow Chicken. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Comparative Study of Bio-implantable Acoustic Generator Architectures

    International Nuclear Information System (INIS)

    Christensen, D; Roundy, S

    2013-01-01

    This paper is a comparative study of the design spaces of two bio-implantable acoustically excited generator architectures: the thickness-stretch-mode circular piezoelectric plate and the bending-mode unimorph piezoelectric diaphragm. The generators are part of an acoustic power transfer system for implanted sensors and medical devices such as glucose monitors, metabolic monitors, drug delivery systems, etc. Our studies indicate that at small sizes the diaphragm architecture outperforms the plate architecture. This paper will present the results of simulation studies and initial experiments that explore the characteristics of the two architectures and compare their performance

  6. Mercury reduces avian reproductive success and imposes selection: an experimental study with adult- or lifetime-exposure in zebra finch.

    Directory of Open Access Journals (Sweden)

    Claire W Varian-Ramos

    Full Text Available Mercury is a global pollutant that biomagnifies in food webs, placing wildlife at risk of reduced reproductive fitness and survival. Songbirds are the most diverse branch of the avian evolutionary tree; many are suffering persistent and serious population declines and we know that songbirds are frequently exposed to mercury pollution. Our objective was to determine the effects of environmentally relevant doses of mercury on reproductive success of songbirds exposed throughout their lives or only as adults. The two modes of exposure simulated philopatric species versus dispersive species, and are particularly relevant because of the heightened mercury-sensitivity of developing nervous systems. We performed a dosing study with dietary methylmercury in a model songbird species, the zebra finch (Taeniopygia guttata, at doses from 0.3 - 2.4 parts per million. Birds were exposed to mercury either as adults only or throughout their lives. All doses of mercury reduced reproductive success, with the lowest dose reducing the number of independent offspring produced in one year by 16% and the highest dose, representing approximately half the lethal dose for this species, causing a 50% reduction. While mercury did not affect clutch size or survivorship, it had the most consistent effect on the proportion of chicks that fledged from the nest, regardless of mode of exposure. Among birds exposed as adults, mercury caused a steep increase in the latency to re-nest after loss of a clutch. Birds exposed for their entire lifetimes, which were necessarily the offspring of dosed parents, had up to 50% lower reproductive success than adult-exposed birds at low doses of methylmercury, but increased reproductive success at high doses, suggesting selection for mercury tolerance at the highest level of exposure. Our results indicate that mercury levels in prey items at contaminated sites pose a significant threat to populations of songbirds through reduced reproductive

  7. Mercury Reduces Avian Reproductive Success and Imposes Selection: An Experimental Study with Adult- or Lifetime-Exposure in Zebra Finch

    Science.gov (United States)

    Varian-Ramos, Claire W.; Swaddle, John P.; Cristol, Daniel A.

    2014-01-01

    Mercury is a global pollutant that biomagnifies in food webs, placing wildlife at risk of reduced reproductive fitness and survival. Songbirds are the most diverse branch of the avian evolutionary tree; many are suffering persistent and serious population declines and we know that songbirds are frequently exposed to mercury pollution. Our objective was to determine the effects of environmentally relevant doses of mercury on reproductive success of songbirds exposed throughout their lives or only as adults. The two modes of exposure simulated philopatric species versus dispersive species, and are particularly relevant because of the heightened mercury-sensitivity of developing nervous systems. We performed a dosing study with dietary methylmercury in a model songbird species, the zebra finch (Taeniopygia guttata), at doses from 0.3 – 2.4 parts per million. Birds were exposed to mercury either as adults only or throughout their lives. All doses of mercury reduced reproductive success, with the lowest dose reducing the number of independent offspring produced in one year by 16% and the highest dose, representing approximately half the lethal dose for this species, causing a 50% reduction. While mercury did not affect clutch size or survivorship, it had the most consistent effect on the proportion of chicks that fledged from the nest, regardless of mode of exposure. Among birds exposed as adults, mercury caused a steep increase in the latency to re-nest after loss of a clutch. Birds exposed for their entire lifetimes, which were necessarily the offspring of dosed parents, had up to 50% lower reproductive success than adult-exposed birds at low doses of methylmercury, but increased reproductive success at high doses, suggesting selection for mercury tolerance at the highest level of exposure. Our results indicate that mercury levels in prey items at contaminated sites pose a significant threat to populations of songbirds through reduced reproductive success. PMID

  8. Low participation rates amongst Asian women: implications for research in reproductive medicine.

    Science.gov (United States)

    Talaulikar, V S; Hussain, S; Perera, A; Manyonda, I T

    2014-03-01

    The last two decades have witnessed tremendous advances in the field of reproductive medicine, especially assisted reproductive technology and stem cell research. As research continues in future, it is vital to ensure that individuals from all ethnic backgrounds are represented in the study populations so that the findings of the research can be generalised for the benefit of all. Many studies, however, have noted a trend of low participation rates amongst Asian women in reproductive research. Inequalities in the ethnicity of research participants can be a source of substantial bias, and have major ethical and scientific ramifications. Several factors such as educational status, fear of wrong-doing, communication barriers, and socio-cultural beliefs have been suggested to play a role. There is a need for further exploration of the factors influencing Asian women's decision to accept or decline participation in reproductive research and for development of effective targeted strategies for research recruitment with the aim of encouraging research participation as well as donation of cryopreserved embryos or other reproductive tissues. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Are hotshots always hot? A longitudinal study of hormones, behavior, and reproductive success in male marine iguanas.

    Science.gov (United States)

    Vitousek, Maren N; Rubenstein, Dustin R; Nelson, Karin N; Wikelski, Martin

    2008-07-01

    Polygynous lek-mating systems are characterized by high reproductive skew, with a small number of males gaining a disproportionate share of copulations. In lekking species, where female choice drives male mating success and patterns of reproductive skew, female preferences for 'good genes' should lead to preferred males having high reproductive success in all years. Here we investigate whether these 'hotshot' males have steroid hormone patterns that are consistent over time (between two mating seasons), and whether hormone levels consistently predict display behavior. We test these questions in the Galápagos marine iguana (Amblyrhynchus cristatus), a lekking vertebrate with high male reproductive skew. We found that male mating success and testosterone levels were not consistent across years. The most successful males showed an inverse relationship in copulation success between years. Similarly, territorial males that had high testosterone in one year had low levels in the next. Across years, testosterone was strongly associated with head-bob display, suggesting that this steroid plays a key role in mate attraction. These results suggest that female marine iguanas are not choosing the same 'hotshot' males in every year, but instead base their reproductive decisions on male behavioral traits that are hormonally mediated and variable across years. By using testosterone to regulate their costly display behaviors male marine iguanas appear to have a mechanism that allows them to adjust their reproductive effort depending on extrinsic and/or intrinsic factors.

  10. Introduction: Communicating Reproduction.

    Science.gov (United States)

    Hopwood, Nick; Jones, Peter Murray; Kassell, Lauren; Secord, Jim

    2015-01-01

    Communication should be central to histories of reproduction, because it has structured how people do and do not reproduce. Yet communication has been so pervasive, and so various, that it is often taken for granted and the historical specificities overlooked. Making communication a frame for histories of reproduction can draw a fragmented field together, including by putting the promotion of esoteric ideas on a par with other practical activities. Paying communication close attention can revitalize the history of reproduction over the long term by highlighting continuities as well as the complex connections between new technologies and new approaches. Themes such as the power of storytelling, the claiming and challenging of expertise, and relations between knowledge and ignorance, secrecy and propriety also invite further study.

  11. Impaired reproduction after exposure to ADHD drugs

    DEFF Research Database (Denmark)

    Danborg, Pia Brandt; Simonsen, Anders Lykkemark; Gøtzsche, Peter C

    2017-01-01

    BACKGROUND: Few studies have reported on long-term harms caused by ADHD drugs but they are known to impair growth. OBJECTIVE: To assess whether ADHD drugs impair reproduction in mammals. METHODS: Systematic review of reproduction in studies of animals treated with ADHD drugs. DATA SOURCES: Pub....... CONCLUSION: ADHD drugs impair the reproduction in animals....

  12. Female reproductive disorders

    DEFF Research Database (Denmark)

    Crain, D Andrew; Janssen, Sarah J; Edwards, Thea M

    2008-01-01

    To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive...... disruptions warrant evaluation of the impact of EDCs on female reproductive health....

  13. Reproductive sharing among queens in the ant Formica fusca

    OpenAIRE

    Minttumaaria Hannonen; Liselotte Sundstro¨m

    2003-01-01

    Reproductive sharing among cobreeders, in which reproductive shares may vary from equal contribution (low reproductive skew) to reproductive dominance by one individual (high reproductive skew), is a fundamental feature of animal societies. Recent theoretical work, the reproductive skew models, has focused on factors affecting the degree to which reproduction is skewed within a society. We used the parameters provided by skew models as a guideline to study determinants of reproductive sharing...

  14. Parametric study for horizontal steam generator modelling

    Energy Technology Data Exchange (ETDEWEB)

    Ovtcharova, I. [Energoproekt, Sofia (Bulgaria)

    1995-12-31

    In the presentation some of the calculated results of horizontal steam generator PGV - 440 modelling with RELAP5/Mod3 are described. Two nodalization schemes have been used with different components in the steam dome. A study of parameters variation on the steam generator work and calculated results is made in cases with separator and branch.

  15. Parametric study for horizontal steam generator modelling

    Energy Technology Data Exchange (ETDEWEB)

    Ovtcharova, I [Energoproekt, Sofia (Bulgaria)

    1996-12-31

    In the presentation some of the calculated results of horizontal steam generator PGV - 440 modelling with RELAP5/Mod3 are described. Two nodalization schemes have been used with different components in the steam dome. A study of parameters variation on the steam generator work and calculated results is made in cases with separator and branch.

  16. A Biometric Study of Some Reproductive Components of the Male ...

    African Journals Online (AJOL)

    A biometrical study was conducted on some aspects of the reproductive system of 16 local breed Tom cats (Felis catus domestica) collected within Sokoto metropolis at different ages. The age of the cats was estimated from teeth eruption and wearing and grouped into groups A to E as A (3- 6 months), B(6 months - 1 year), ...

  17. Adolescent-parent communication on sexual and reproductive health issues among high school students in Dire Dawa, Eastern Ethiopia: a cross sectional study.

    Science.gov (United States)

    Ayalew, Mulatuwa; Mengistie, Bezatu; Semahegn, Agumasie

    2014-11-07

    Sexual and reproductive health communications are most likely promoting healthy sexual development and reduce sexual risks. Communication is the principal means for parents to transmit sexual values, beliefs, expectations and knowledge to their adolescents. However, there is a paucity of evidence about adolescent parent communication in Ethiopia. This study aimed to determine adolescent-parent communication on sexual and reproductive health issues and associated factors among high school students in Dire Dawa, Eastern Ethiopia. Institution based cross sectional study was conducted among high school students in Dire Dawa administrative council from February to March 2011. Simple random sampling technique was used to select 695 students from 9-12 grades. Qualitative data were collected through focus group discussion separately for female and male parents. Data were entered in Epi info version 3.5.1 and analyzed by SPSS version 16.1. Logistic regression with OR and 95% confidence interval was used to identify the independent predictors of adolescent parent communication. Thirty seven percent of students had ever discussed on at least two sexual and reproductive health topics with their parents. Of which, majority of student preferred to discuss with their peers than parent. Condom use during first intercourse was associated with having communication about sexual and reproductive health [AOR=1.9, 95% CI: 1.0, 3.8]. Cultural taboo, shame and lack of communication skill were reasons that hinder communication between parent and adolescent about sexual matters. Communication on sexual and reproductive health issue between adolescent and their parent was low. School based education is important to improve adolescent parent communication about sexual and reproductive health issues.

  18. The Potential of Modern Russian Generations

    Directory of Open Access Journals (Sweden)

    Valentina Grigor’evna Dobrokhleb

    2016-05-01

    Full Text Available The paper considers the necessity of socio-demographic approach to assessing the potential of modern generations. The demographic potential of generations is determined by their number, their share in total population, and their life expectancy. Their economic potential is determined by the proportion of representatives of different generations in total employment. Their social potential is determined by the system of values of generations. The rapid growth of differences in these characteristics leads to the break up of intergenerational relations and is connected with the aggravation of social contradictions. The potential of modern generations can be considered in different aspects: number of generations, life expectancy at birth, the share of representatives of different generations that share or do not share the basic social values of the society, including values related to reproductive and other types of demographic behavior. In order to identify existing differences between generations in the framework of the socio-demographic approach, the paper analyzes the dynamics of the number of young people in 1926, 1936, 2014 in the Russian Federation; the authors also carry out a comparative analysis of the secondary and authors’ sociological data of values-related and reproductive attitudes of conditionally parental and child generations. Russian researchers studied the life potential of the population and proved that in 1990–2010, the life potential of Russia’s population decreased. Reduction in the life potential in the population in general is associated with a decrease in this indicator for the younger generation (children’s ages due to the reduction in the number and proportion of this generation in the population structure. The reduction in the life potential has not stopped because the number of the younger generation continues to decrease. However, life expectancy in this period increased. Nevertheless, in general, mortality in

  19. Effects of fluctuating temperature and food availability on reproduction and lifespan.

    Science.gov (United States)

    Schwartz, Tonia S; Pearson, Phillip; Dawson, John; Allison, David B; Gohlke, Julia M

    2016-12-15

    Experimental studies on energetics and aging often remove two major factors that in part regulate the energy budget in a normal healthy individual: reproduction and fluctuating environmental conditions that challenge homeostasis. Here we use the cyclical parthenogenetic Daphnia pulex to evaluate the role of a fluctuating thermal environment on both reproduction and lifespan across six food concentrations. We test the hypotheses that (1) caloric restriction extends lifespan; (2) maximal reproduction will come with a cost of shortened lifespan; and (3) at a given food concentration, relative to a metabolically equivalent constant temperature environment a diel fluctuating thermal environment will alter the allocation of energy to reproduction and lifespan to maintain homeostasis. We did not identify a level of food concentration that extended lifespan in response to caloric restriction, and we found no cost of reproduction in terms of lifespan. Rather, the individuals at the highest food levels generally had the highest reproductive output and the longest lifespans, the individuals at the intermediate food level decreased reproduction and maintained lifespan, and the individuals at the three lower food concentrations had a decrease in reproduction and lifespan as would be predicted with increasing levels of starvation. Fluctuating temperature had no effect on lifespan at any food concentration, but delayed time to reproductive maturity and decreased early reproductive output at all food concentrations. This suggests that a fluctuating temperature regimen activates molecular pathways that alter energy allocation. The costs of fluctuating temperature on reproduction were not consistent across the lifespan. Statistical interactions for age of peak reproduction and lifetime fecundity suggest that senescence of the reproductive system may vary between temperature regimens at the different food concentrations. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Trans-generational study of DNA alterations and their consequences on life history traits and energy budget of Daphnia magna exposed to depleted uranium

    International Nuclear Information System (INIS)

    Plaire, Delphine

    2013-01-01

    Understanding how toxicants affect species at various levels of biological organization is a major research goal in both ecotoxicology and radioecology. As part of IRSN program ENVIRHOM, which aims to assess environmental risks related to the presence of radionuclides in the environment, this PhD work explored how depleted uranium alters DNA and affects life history traits (survival, growth and reproduction) of an aquatic invertebrate, Daphnia magna. To answer to this problematic, an experimental approach and a modeling approach are conducted. An experimental study is performed to evaluate DNA accumulation and transmission during an uranium exposure (0; 2; 9.9; 22.2 and 50 μg.L -1 ) over two successive generations (F0 and F1). Different exposures scenarios (continuous, post-hatching and embryo exposure) are achieved to test the specific sensitivity of several life stages to uranium. Genotoxic effects are estimated using random amplified DNA technique combined with PCR (PCR-RAPD). In continuous and post-hatching exposure scenarios, results highlighted an accumulation and a transmission of DNA damage across generations with an increase in effect severity. DNA alterations are reported at hatching of the F1 generation at a concentration as low as 2 μg.L -1 . Effects on growth and reproduction are stronger when the embryo stage is exposed and remain visible at 9.9 μg.L -1 despite a return in a clean medium at hatching. Results suggest that DNA damage could be used as early indicators of future effects on life history traits. A mechanistic analysis of experimental results is conducted using a DEBtox model (dynamic energy budget applied to toxicology) to better understand the causes of the increase in effect severity across generations. A model with two stress factors (one correlated to external concentration and another correlated to a damage level) is developed. Results of fits suggest the involvement of one second mode of action to explain immediate effects of

  1. Comparison of two methods for composite score generation in dry eye syndrome.

    Science.gov (United States)

    See, Craig; Bilonick, Richard A; Feuer, William; Galor, Anat

    2013-09-19

    To compare two methods of composite score generation in dry eye syndrome (DES). Male patients seen in the Miami Veterans Affairs eye clinic with normal eyelid, corneal, and conjunctival anatomy were recruited to participate in the study. Patients filled out the Dry Eye Questionnaire 5 (DEQ5) and underwent measurement of tear film parameters. DES severity scores were generated by independent component analysis (ICA) and latent class analysis (LCA). A total of 247 men were included in the study. Mean age was 69 years (SD 9). Using ICA analysis, osmolarity was found to carry the largest weight, followed by eyelid vascularity and meibomian orifice plugging. Conjunctival injection and tear breakup time (TBUT) carried the lowest weights. Using LCA analysis, TBUT was found to be best at discriminating healthy from diseased eyes, followed closely by Schirmer's test. DEQ5, eyelid vascularity, and conjunctival injection were the poorest at discrimination. The adjusted correlation coefficient between the two generated composite scores was 0.63, indicating that the shared variance was less than 40%. Both ICA and LCA produced composite scores for dry eye severity, with weak to moderate agreement; however, agreement for the relative importance of single diagnostic tests was poor between the two methods.

  2. Transcriptomics Analysis of Crassostrea hongkongensis for the Discovery of Reproduction-Related Genes

    Science.gov (United States)

    Tong, Ying; Zhang, Yang; Huang, Jiaomei; Xiao, Shu; Zhang, Yuehuan; Li, Jun; Chen, Jinhui; Yu, Ziniu

    2015-01-01

    Background The reproductive mechanisms of mollusk species have been interesting targets in biological research because of the diverse reproductive strategies observed in this phylum. These species have also been studied for the development of fishery technologies in molluscan aquaculture. Although the molecular mechanisms underlying the reproductive process have been well studied in animal models, the relevant information from mollusks remains limited, particularly in species of great commercial interest. Crassostrea hongkongensis is the dominant oyster species that is distributed along the coast of the South China Sea and little genomic information on this species is available. Currently, high-throughput sequencing techniques have been widely used for investigating the basis of physiological processes and facilitating the establishment of adequate genetic selection programs. Results The C.hongkongensis transcriptome included a total of 1,595,855 reads, which were generated by 454 sequencing and were assembled into 41,472 contigs using de novo methods. Contigs were clustered into 33,920 isotigs and further grouped into 22,829 isogroups. Approximately 77.6% of the isogroups were successfully annotated by the Nr database. More than 1,910 genes were identified as being related to reproduction. Some key genes involved in germline development, sex determination and differentiation were identified for the first time in C.hongkongensis (nanos, piwi, ATRX, FoxL2, β-catenin, etc.). Gene expression analysis indicated that vasa, nanos, piwi, ATRX, FoxL2, β-catenin and SRD5A1 were highly or specifically expressed in C.hongkongensis gonads. Additionally, 94,056 single nucleotide polymorphisms (SNPs) and 1,699 simple sequence repeats (SSRs) were compiled. Conclusions Our study significantly increased C.hongkongensis genomic information based on transcriptomics analysis. The group of reproduction-related genes identified in the present study constitutes a new tool for research

  3. Transcriptomics Analysis of Crassostrea hongkongensis for the Discovery of Reproduction-Related Genes.

    Directory of Open Access Journals (Sweden)

    Ying Tong

    Full Text Available The reproductive mechanisms of mollusk species have been interesting targets in biological research because of the diverse reproductive strategies observed in this phylum. These species have also been studied for the development of fishery technologies in molluscan aquaculture. Although the molecular mechanisms underlying the reproductive process have been well studied in animal models, the relevant information from mollusks remains limited, particularly in species of great commercial interest. Crassostrea hongkongensis is the dominant oyster species that is distributed along the coast of the South China Sea and little genomic information on this species is available. Currently, high-throughput sequencing techniques have been widely used for investigating the basis of physiological processes and facilitating the establishment of adequate genetic selection programs.The C.hongkongensis transcriptome included a total of 1,595,855 reads, which were generated by 454 sequencing and were assembled into 41,472 contigs using de novo methods. Contigs were clustered into 33,920 isotigs and further grouped into 22,829 isogroups. Approximately 77.6% of the isogroups were successfully annotated by the Nr database. More than 1,910 genes were identified as being related to reproduction. Some key genes involved in germline development, sex determination and differentiation were identified for the first time in C.hongkongensis (nanos, piwi, ATRX, FoxL2, β-catenin, etc.. Gene expression analysis indicated that vasa, nanos, piwi, ATRX, FoxL2, β-catenin and SRD5A1 were highly or specifically expressed in C.hongkongensis gonads. Additionally, 94,056 single nucleotide polymorphisms (SNPs and 1,699 simple sequence repeats (SSRs were compiled.Our study significantly increased C.hongkongensis genomic information based on transcriptomics analysis. The group of reproduction-related genes identified in the present study constitutes a new tool for research on bivalve

  4. Fertility-related knowledge and information-seeking behaviour among people of reproductive age: a qualitative study.

    Science.gov (United States)

    Hammarberg, Karin; Zosel, Rebecca; Comoy, Caroline; Robertson, Sarah; Holden, Carol; Deeks, Mandy; Johnson, Louise

    2017-06-01

    Some potentially modifiable factors adversely affect fertility and pregnancy health. To inform a fertility health promotion programme, this study investigated fertility knowledge and information-seeking behaviour among people of reproductive age. This was a qualitative study involving six focus group discussions with women and men who intended to have children in the future and eight paired interviews with couples who were actively trying to conceive. Participants (n = 74) themselves generally claimed 'low' to 'average' levels of knowledge about fertility. Most of them overestimated women's reproductive lifespan and had limited knowledge about the 'fertile window' of the menstrual cycle. The Internet was a common source of fertility-related information and social media was viewed as a potential effective avenue for dissemination of messages about fertility and how to protect it. Most participants agreed that primary health care providers, such as general practitioners (GPs), are well placed to provide information regarding fertility and pregnancy health. This study identified several gaps in knowledge among people of reproductive age about factors that influence fertility and pregnancy health negatively. Addressing these knowledge gaps in school curricula, primary care and health promotion would assist people to realize their reproductive goals and reduce the risk of infertility and adverse obstetric outcomes.

  5. Associations between intrauterine bacterial infection, reproductive tract inflammation, and reproductive performance in pasture-based dairy cows.

    Science.gov (United States)

    de Boer, Melvin; Buddle, Bryce M; Heuer, Cord; Hussein, Hassan; Zheng, Tao; LeBlanc, Stephen J; McDougall, Scott

    2015-06-01

    Reproductive tract bacterial infections, particularly those caused by Escherichia coli and Trueperella pyogenes, can have a negative impact on reproductive performance. It has been hypothesized that the presence of E coli early postpartum may increase the risk of isolation of T pyogenes later postpartum. The objective of the present study was to examine associations between intrauterine bacterial infections with E coli and T pyogenes and any bacterial growth (irrespective of bacterial species), purulent vaginal discharge (PVD), cytologic evidence of endometritis (an increased proportion of polymorphonuclear cells [PMNs]), and reproductive performance. Dairy cows (n = 272) from six herds were examined at Days 0 (median, 2 days in milk), 21 and 42 postpartum. From each cow two intrauterine samples were collected via triple-guarded cytobrush at Days 0 and 21. The first cytobrush was used for bacteriologic culture. Escherichia coli and T pyogenes were isolated by culture, and E coli isolates were assigned to one of four phylogenetic groups using a two-step triplex polymerase chain reaction. In addition, T pyogenes was confirmed by polymerase chain reaction. The second cytobrush was used to prepare a cytology slide. Nucleated cells (n = 200) were categorized as epithelial cells, PMNs, or macrophages. Cows were also assessed for body condition score, PVD score, the presence of a CL, and pregnancy. Statistical analysis was performed using multivariable models. There was no association between the presence of E coli at Day 0 and probability of isolation of T pyogenes 3 weeks later; however, E coli positive cows at Day 0 were more likely to be diagnosed with E coli at Day 21 (relative risk [RR] = 2.0, P bacterial growth at Day 21, irrespective of species, were less likely to conceive within 3 weeks after the start of the seasonal breeding program (RR = 0.8; P = 0.05). Interestingly, cows with 25% PMNs or greater at Day 0 had shorter time to pregnancy (hazard ratio = 1.32; P

  6. Assisted reproductive travel: UK patient trajectories.

    Science.gov (United States)

    Hudson, Nicky; Culley, Lorraine

    2011-11-01

    Media reporting of 'fertility tourism' tends to portray those who travel as a cohesive group, marked by their desperation and/or selfishness and propensity towards morally questionable behaviour. However, to date little has been known about the profile of those leaving the UK for treatment. This paper discusses the first UK-based study of patient assisted reproduction travel that was designed to explore individual travel trajectories. It is argued that existing ways of conceptualizing cross-border reproductive care as 'fertility or reproductive tourism' are in danger of essentializing what the data suggest are diverse, complex and often ambiguous motivations for reproductive travel. The concept of seriality is used to suggest that, whilst 'reproductive tourists' share some characteristics, they also differ in significant ways. This paper argues that, through an examination of the personal landscapes of fertility travel, the diverse processes involved in reproductive travel can be better understood and policymakers can be assisted to avoid what might be regarded as simplistic responses to cross-border reproductive care. Copyright © 2011 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  7. Toll-like receptors in the gonads and reproductive tract: emerging roles in reproductive physiology and pathology.

    Science.gov (United States)

    Girling, Jane E; Hedger, Mark P

    2007-01-01

    Interactions between the immune system and reproductive system have important consequences for fertility and reproductive health in general. There is increasing evidence that many of the interactions between the immune and reproductive systems involve the Toll-like receptors (TLRs). While there is no doubt that TLRs are important in providing protection against infection in the reproductive tract, there is increasing evidence for the involvement of TLRs in more basic pathology and physiology of reproduction. In the female, TLRs have been implicated in critical aspects of ovarian, endometrial and placental function, as well as in ovarian cancer, pelvic inflammatory disease, intrauterine growth restriction, pre-eclampsia and preterm birth. In the male, TLRs appear to play a role in the control of testicular steroidogenesis and spermatogenesis in disease and, potentially, during normal function, as well. Recent studies also have begun to highlight the role of various TLRs in the aetiology of prostatitis and prostatic cancer. Given the nascent state of knowledge concerning this important area, it is clear that more studies are needed, which should provide valuable new insights into the biology of the TLRs and reproductive function in general.

  8. Maternal exposure to di(2-ethylhexyl)phthalate (DEHP) promotes the transgenerational inheritance of adult-onset reproductive dysfunctions through the female germline in mice

    International Nuclear Information System (INIS)

    Pocar, Paola; Fiandanese, Nadia; Berrini, Anna; Secchi, Camillo; Borromeo, Vitaliano

    2017-01-01

    Endocrine disruptors (EDs) are compounds known to promote transgenerational inheritance of adult-onset disease in subsequent generations after maternal exposure during fetal gonadal development. This study was designed to establish whether gestational and lactational exposure to the plasticizer di(2-ethylhexyl)phthalate (DEHP) at environmental doses promotes transgenerational effects on reproductive health in female offspring, as adults, over three generations in the mouse. Gestating F0 mouse dams were exposed to 0, 0.05, 5 mg/kg/day DEHP in the diet from gestational day 0.5 until the end of lactation. The incidence of adult-onset disease in reproductive function was recorded in F1, F2 and F3 female offspring. In adult F1 females, DEHP exposure induced reproductive adverse effects with: i) altered ovarian follicular dynamics with reduced primordial follicular reserve and a larger growing pre-antral follicle population, suggesting accelerated follicular recruitment; ii) reduced oocyte quality and embryonic developmental competence; iii) dysregulation of the expression profile of a panel of selected ovarian and pre-implantation embryonic genes. F2 and F3 female offspring displayed the same altered reproductive morphological phenotype and gene expression profiles as F1, thus showing transgenerational transmission of reproductive adverse effects along the female lineage. These findings indicate that in mice exposure to DEHP at doses relevant to human exposure during gonadal sex determination significantly perturbs the reproductive indices of female adult offspring and subsequent generations. Evidence of transgenerational transmission has important implications for the reproductive health and fertility of animals and humans, significantly increasing the potential biohazards of this toxicant. - Highlights: • Maternal exposure to DEHP transgenerationally affects female reproductive health. • DEHP reduced ovarian follicular reserve up to the third generation. • DEHP

  9. Maternal exposure to di(2-ethylhexyl)phthalate (DEHP) promotes the transgenerational inheritance of adult-onset reproductive dysfunctions through the female germline in mice

    Energy Technology Data Exchange (ETDEWEB)

    Pocar, Paola, E-mail: paola.pocar@unimi.it; Fiandanese, Nadia; Berrini, Anna; Secchi, Camillo; Borromeo, Vitaliano

    2017-05-01

    Endocrine disruptors (EDs) are compounds known to promote transgenerational inheritance of adult-onset disease in subsequent generations after maternal exposure during fetal gonadal development. This study was designed to establish whether gestational and lactational exposure to the plasticizer di(2-ethylhexyl)phthalate (DEHP) at environmental doses promotes transgenerational effects on reproductive health in female offspring, as adults, over three generations in the mouse. Gestating F0 mouse dams were exposed to 0, 0.05, 5 mg/kg/day DEHP in the diet from gestational day 0.5 until the end of lactation. The incidence of adult-onset disease in reproductive function was recorded in F1, F2 and F3 female offspring. In adult F1 females, DEHP exposure induced reproductive adverse effects with: i) altered ovarian follicular dynamics with reduced primordial follicular reserve and a larger growing pre-antral follicle population, suggesting accelerated follicular recruitment; ii) reduced oocyte quality and embryonic developmental competence; iii) dysregulation of the expression profile of a panel of selected ovarian and pre-implantation embryonic genes. F2 and F3 female offspring displayed the same altered reproductive morphological phenotype and gene expression profiles as F1, thus showing transgenerational transmission of reproductive adverse effects along the female lineage. These findings indicate that in mice exposure to DEHP at doses relevant to human exposure during gonadal sex determination significantly perturbs the reproductive indices of female adult offspring and subsequent generations. Evidence of transgenerational transmission has important implications for the reproductive health and fertility of animals and humans, significantly increasing the potential biohazards of this toxicant. - Highlights: • Maternal exposure to DEHP transgenerationally affects female reproductive health. • DEHP reduced ovarian follicular reserve up to the third generation. • DEHP

  10. The concentration of plasma metabolites varies throughout reproduction and affects offspring number in wild brown trout (Salmo trutta).

    Science.gov (United States)

    Gauthey, Zoé; Freychet, Marine; Manicki, Aurélie; Herman, Alexandre; Lepais, Olivier; Panserat, Stéphane; Elosegi, Arturo; Tentelier, Cédric; Labonne, Jacques

    2015-06-01

    In wild populations, measuring energy invested in the reproduction and disentangling investment in gametes versus investment in reproductive behavior (such as intrasexual competition or intersexual preference) remain challenging. In this study, we investigated the energy expenditure in brown trout reproductive behavior by using two proxies: variation in weight and variation of plasma metabolites involved in energy production, over the course of reproductive season in a semi natural experimental river. We estimated overall reproductive success using genetic assignment at the end of the reproductive season. Results show that triglycerides and free fatty acid concentrations vary negatively during reproduction, while amino-acids and glucose concentrations remain stable. Decrease in triglyceride and free fatty acid concentrations during reproduction is not related to initial concentration levels or to weight variation. Both metabolite concentration variations and weight variations are correlated to the number of offspring produced, which could indicate that gametic and behavioral reproductive investments substantially contribute to reproductive success in wild brown trout. This study opens a path to further investigate variations in reproductive investment in wild populations. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Experiencing reproductive concerns as a female cancer survivor is associated with depression

    Science.gov (United States)

    Gorman, Jessica R.; Su, H. Irene; Roberts, Samantha C.; Dominick, Sally A.; Malcarne, Vanessa L.

    2014-01-01

    Background Young adult female cancer survivors have unmet reproductive concerns and informational needs that are associated with poorer quality of life. The purpose of this study was to examine the association between current reproductive concerns and moderate to severe depression among young survivors. Methods This cross-sectional study includes 200 female cancer survivors between the ages of 18 and 35 years who completed a web-based survey measuring reproductive history, parenthood desires, reproductive concerns after cancer, and quality of life indicators. Results The mean age of participants was 28 years (SD = 4.4) and almost two-thirds were diagnosed within 5 years of completing the survey. Multivariable logistic regression analysis controlling for education, duration of survivorship, and social support revealed an association between experiencing reproductive concerns and moderate to severe depression (OR = 1.30, 95% CI = 1.06–1.60 for each 5 unit increase in RCAC score). Of those with moderate to severe depression, 23% had high RCAC scores as compared to 6% of those with minimal to mild depression (p < 0.001). Conclusion A higher level of reproductive concerns was associated with greater odds of experiencing moderate to severe depression. Almost a quarter of survivors in this sample reported moderate to severe depression, and addressing reproductive concerns represents one potential area of intervention to improve the psychosocial health of young survivors. PMID:25377593

  12. Immotile Active Matter: Activity from Death and Reproduction

    Science.gov (United States)

    Kalziqi, Arben; Yanni, David; Thomas, Jacob; Ng, Siu Lung; Vivek, Skanda; Hammer, Brian K.; Yunker, Peter J.

    2018-01-01

    Unlike equilibrium atomic solids, biofilms—soft solids composed of bacterial cells—do not experience significant thermal fluctuations at the constituent level. However, living cells stochastically reproduce and die, provoking a mechanical response. We investigate the mechanical consequences of cellular death and reproduction by measuring surface-height fluctuations of biofilms containing two mutually antagonistic strains of Vibrio cholerae that kill one another on contact via the type VI secretion system. While studies of active matter typically focus on activity via constituent mobility, here, activity is mediated by reproduction and death events in otherwise immobilized cells. Biofilm surface topography is measured in the nearly homeostatic limit via white light interferometry. Although biofilms are far from equilibrium systems, measured surface-height fluctuation spectra resemble the spectra of thermal permeable membranes but with an activity-mediated effective temperature, as predicted by Risler, Peilloux, and Prost [Phys. Rev. Lett. 115, 258104 (2015), 10.1103/PhysRevLett.115.258104]. By comparing the activity of killer strains of V. cholerae with that of genetically modified strains that cannot kill each other and validating with individual-based simulations, we demonstrate that extracted effective temperatures increase with the amount of death and reproduction and that death and reproduction can fluidize biofilms. Together, these observations demonstrate the unique physical consequences of activity mediated by death and reproduction events.

  13. Reproductive effort in biparental care : an experimental study in long-lived Cape gannets

    NARCIS (Netherlands)

    Bijleveld, Allert I.; Mullers, Ralf H. E.

    2009-01-01

    Life-history theory predicts a trade-off between current and future reproduction, such that long-lived species should not increase their reproductive effort (RE) at a cost to their own survival. In species with long-term pair bonds and biparental care, each parent must balance its reproductive

  14. Unisexual reproduction drives meiotic recombination and phenotypic and karyotypic plasticity in Cryptococcus neoformans.

    Directory of Open Access Journals (Sweden)

    Sheng Sun

    2014-12-01

    Full Text Available In fungi, unisexual reproduction, where sexual development is initiated without the presence of two compatible mating type alleles, has been observed in several species that can also undergo traditional bisexual reproduction, including the important human fungal pathogens Cryptococcus neoformans and Candida albicans. While unisexual reproduction has been well characterized qualitatively, detailed quantifications are still lacking for aspects of this process, such as the frequency of recombination during unisexual reproduction, and how this compares with bisexual reproduction. Here, we analyzed meiotic recombination during α-α unisexual and a-α bisexual reproduction of C. neoformans. We found that meiotic recombination operates in a similar fashion during both modes of sexual reproduction. Specifically, we observed that in α-α unisexual reproduction, the numbers of crossovers along the chromosomes during meiosis, recombination frequencies at specific chromosomal regions, as well as meiotic recombination hot and cold spots, are all similar to those observed during a-α bisexual reproduction. The similarity in meiosis is also reflected by the fact that phenotypic segregation among progeny collected from the two modes of sexual reproduction is also similar, with transgressive segregation being observed in both. Additionally, we found diploid meiotic progeny were also produced at similar frequencies in the two modes of sexual reproduction, and transient chromosomal loss and duplication likely occurs frequently and results in aneuploidy and loss of heterozygosity that can span entire chromosomes. Furthermore, in both α-α unisexual and a-α bisexual reproduction, we observed biased allele inheritance in regions on chromosome 4, suggesting the presence of fragile chromosomal regions that might be vulnerable to mitotic recombination. Interestingly, we also observed a crossover event that occurred within the MAT locus during α-α unisexual

  15. Unisexual Reproduction Drives Meiotic Recombination and Phenotypic and Karyotypic Plasticity in Cryptococcus neoformans

    Science.gov (United States)

    Sun, Sheng; Billmyre, R. Blake; Mieczkowski, Piotr A.; Heitman, Joseph

    2014-01-01

    In fungi, unisexual reproduction, where sexual development is initiated without the presence of two compatible mating type alleles, has been observed in several species that can also undergo traditional bisexual reproduction, including the important human fungal pathogens Cryptococcus neoformans and Candida albicans. While unisexual reproduction has been well characterized qualitatively, detailed quantifications are still lacking for aspects of this process, such as the frequency of recombination during unisexual reproduction, and how this compares with bisexual reproduction. Here, we analyzed meiotic recombination during α-α unisexual and a-α bisexual reproduction of C. neoformans. We found that meiotic recombination operates in a similar fashion during both modes of sexual reproduction. Specifically, we observed that in α-α unisexual reproduction, the numbers of crossovers along the chromosomes during meiosis, recombination frequencies at specific chromosomal regions, as well as meiotic recombination hot and cold spots, are all similar to those observed during a-α bisexual reproduction. The similarity in meiosis is also reflected by the fact that phenotypic segregation among progeny collected from the two modes of sexual reproduction is also similar, with transgressive segregation being observed in both. Additionally, we found diploid meiotic progeny were also produced at similar frequencies in the two modes of sexual reproduction, and transient chromosomal loss and duplication likely occurs frequently and results in aneuploidy and loss of heterozygosity that can span entire chromosomes. Furthermore, in both α-α unisexual and a-α bisexual reproduction, we observed biased allele inheritance in regions on chromosome 4, suggesting the presence of fragile chromosomal regions that might be vulnerable to mitotic recombination. Interestingly, we also observed a crossover event that occurred within the MAT locus during α-α unisexual reproduction. Our results

  16. Stakeholder's experiences, expectations and decision making on reproductive care: An ethnographic study of three districts in northern Ghana.

    Directory of Open Access Journals (Sweden)

    Martin Amogre Ayanore

    Full Text Available In Ghana, priority-setting for reproductive health service interventions is known to be rudimentary with little wider stakeholder involvement. In recognizing the need for broad stakeholder engagement to advance reproductive care provision and utilization, it is necessary to jointly study the varied stakeholder views on reproductive care services.We applied an ethnographic study approach where field data was collected between March-May 2015 in three rural districts of northern Ghana. Data was collected among women with recent births experiences (n = 90, health care providers (n = 16 and policy actors (n = 6. In-depth interviews and focus group discussions was applied to collect all data. Each stakeholder participant's audio file was transcribed, and repeatedly read through to identify similar and divergent views in data. A coding scheme guided coding processes. All transcripts were then imported into QSR NVivo 11 for further analysis.Four themes emerged. Women participants accentuated that sex and sexuality values of men have changed over time, and drives gender roles, parity levels and decision making on reproductive care needs at community levels. Sexual stigma on reproductive care reduces the willingness of women to voice poor experiences related to their previous reproductive experiences. All stakeholders' highlighted clinical treatments for post-abortion care are minimally covered under the fee exemption policy for antenatal and postnatal care. Policy processes on service delivery protocols still is top-down in Ghana.Health teams working to improve sexual and reproductive health care must find suitable context strategies that effectively work to improve women reproductive care needs at their operational levels. Private sector participation and informal community support clutches are encouraged to advance the delivery of reproductive care services.

  17. A Study in generative process : The art of theorizing

    NARCIS (Netherlands)

    Zandee, D.P.

    2005-01-01

    This dissertation is an inquiry in the process of generativity. The study was inspired by the notion that generative process is vital for the continuous renewal of possibility in our personal, social and organized existence. Generativity is defined in the following two dimensions: an idea, event, or

  18. Exploring the world of human development and reproduction.

    Science.gov (United States)

    Red-Horse, Kristy; Drake, Penelope M; Fisher, Susan

    2014-01-01

    Susan Fisher has spent her career studying human development, proteomics, and the intersection between the two. When she began studying human placentation, there had been extensive descriptive studies of this fascinating organ that intertwines with the mother's vasculature during pregnancy. Susan can be credited with numerous major findings on the mechanisms that regulate placental cytotrophoblast invasion. These include the discovery that cytotrophoblasts undergo vascular mimicry to insert themselves into uterine arteries, the finding that oxygen tension greatly effects placentation, and identifying how these responses go awry in pregnancy complications such as preeclamsia. Other important work has focused on the effect of post-translational modifications such as glycosylation on bacterial adhesion and reproduction. Susan has also forayed into the world of proteomics to identify cancer biomarkers. Because her work is truly groundbreaking, many of these findings inspire research in other laboratories around the world resulting in numerous follow up papers. Likewise, her mentoring and support inspires young scientists to go on and make their own important discoveries. In this interview, Susan shares what drove her science, how she continued to do important research while balancing other aspects of life, and provides insights for the next generation.

  19. Comparison of two biomass-electricity generation technologies in Peninsular Malaysia using linear programming method

    International Nuclear Information System (INIS)

    Kumaran, P.; Hari, Z.; Boosroh, M.H.

    2006-01-01

    Two technologies have been considered to generate electricity using palm oil mill waste, the Empty Fruit Bunch (EFB) as power plant fuel. One technology is to build new 100% EFB fired power plants, located in the vicinity of the palm oil mill, in which the produced electricity would be connected to the national electricity grid system. The other technology is to transport all the available EFB fuel to an existing coal power station in which the EFB fuel would be blended with coal and co-fired in conventional coal power plant to produce electricity. A study intended to compare the difference between these two technologies, to obtain the same electricity generation, has been done. Linear programming software was used simulate the two technologies to generate 5% of Peninsular Malaysia's electricity demand in the year 2005. The study indicated that the co firing technology total cost is 43.7% cheaper than EFB technology and the fuel coat is competitive until transport cost reaches 78 RM/tone

  20. Zika virus and assisted reproduction.

    Science.gov (United States)

    Cordeiro, Christina N; Bano, Rashda; Washington Cross, Chantel I; Segars, James H

    2017-06-01

    Due to the fact that the Zika virus can be sexually transmitted, there is a potential risk for disease transmission at several stages of assisted reproduction. Such a possibility poses a serious challenge to couples pursing fertility with reproductive technologies. Here, we discuss what is known regarding Zika virus infection with respect to sexual transmission and correlate this knowledge with recent recommendations in the realm of infertility treatment. Zika virus can be transmitted from infected men and women through vaginal, oral or anal intercourse. Zika virus RNA has been detected in blood, semen, cervical mucus and vaginal fluid. Currently, the Centers for Disease Control recommends that infected men wait 6 months, and infected women 8 weeks, prior to attempting pregnancy. Reproductive tissue donors should wait 6 months before giving a specimen. Further study of Zika virus transmission in different reproductive tissues and establishment of validated testing methods for viral disease transmissibility are urgently needed. Reproductive technologists need to establish screening, testing and laboratory protocols aimed to reduce the risk of Zika virus transmission during assisted reproduction.

  1. Transcriptome analysis of reproductive tissue and intrauterine developmental stages of the tsetse fly (Glossina morsitans morsitans

    Directory of Open Access Journals (Sweden)

    Wu Yineng

    2010-03-01

    Full Text Available Abstract Background Tsetse flies, vectors of African trypanosomes, undergo viviparous reproduction (the deposition of live offspring. This reproductive strategy results in a large maternal investment and the deposition of a small number of progeny during a female's lifespan. The reproductive biology of tsetse has been studied on a physiological level; however the molecular analysis of tsetse reproduction requires deeper investigation. To build a foundation from which to base molecular studies of tsetse reproduction, a cDNA library was generated from female tsetse (Glossina morsitans morsitans reproductive tissues and the intrauterine developmental stages. 3438 expressed sequence tags were sequenced and analyzed. Results Analysis of a nonredundant catalogue of 1391 contigs resulted in 520 predicted proteins. 475 of these proteins were full length. We predict that 412 of these represent cytoplasmic proteins while 57 are secreted. Comparison of these proteins with other tissue specific tsetse cDNA libraries (salivary gland, fat body/milk gland, and midgut identified 51 that are unique to the reproductive/immature cDNA library. 11 unique proteins were homologus to uncharacterized putative proteins within the NR database suggesting the identification of novel genes associated with reproductive functions in other insects (hypothetical conserved. The analysis also yielded seven putative proteins without significant homology to sequences present in the public database (unknown genes. These proteins may represent unique functions associated with tsetse's viviparous reproductive cycle. RT-PCR analysis of hypothetical conserved and unknown contigs was performed to determine basic tissue and stage specificity of the expression of these genes. Conclusion This paper identifies 51 putative proteins specific to a tsetse reproductive/immature EST library. 11 of these proteins correspond to hypothetical conserved genes and 7 proteins are tsetse specific.

  2. Reproduction and recruitment patterns of the surf clam Donax serra ...

    African Journals Online (AJOL)

    Reproduction and recruitment patterns of the surf clam Donax serra (Bivalvia, Donacidae) on two ... Keywords: condition index, Donax serra, histology, Namibia, recruitment, reproduction, sandy beach ecology ... AJOL African Journals Online.

  3. The reproductive cycle of the oyster Crassostrea gasar

    Directory of Open Access Journals (Sweden)

    CHAM Gomes

    Full Text Available The purpose of this study was to analyze the reproductive cycle of the oyster Crassostrea gasar (= C. brasiliana in the field and the laboratory. The reproductive cycle of the animals was evaluated in the field at Sambaqui Beach, Florianópolis, SC (27° 29′18″ S and 48° 32′12″ W from May 2008 through November 2009. In July, the animals were in the resting stage. The early growth stage began in August and was followed by the late growth stage in October. In November and December, the oysters began to enter the mature stage. Females in spawning condition were predominant during these months. The stages of the reproductive cycle were positively associated with temperature (r=0.77, P<0.01 and negatively associated with salinity (r=−0.56, P=0.042. These findings demonstrated that increased temperature and reduced salinity influence the reproductive development of Crassostrea gasar. The condition index (CI of the animals was also associated with the seawater temperature. The highest values of the condition index were observed during the months when the temperature of the seawater was gradually increasing. A laboratory experiment was performed to test the effect of salinity on the reproductive cycle of the oysters. The experiment was conducted in standardized tanks. The animals were conditioned using two salinities (24‰ and 34‰. The salinity regime influenced the development of the gonadal tissue of the oysters. A salinity of 24‰ produced greater reproductive development.

  4. Grandparental effects in marine sticklebacks: transgenerational plasticity across multiple generations.

    Science.gov (United States)

    Shama, L N S; Wegner, K M

    2014-11-01

    Nongenetic inheritance mechanisms such as transgenerational plasticity (TGP) can buffer populations against rapid environmental change such as ocean warming. Yet, little is known about how long these effects persist and whether they are cumulative over generations. Here, we tested for adaptive TGP in response to simulated ocean warming across parental and grandparental generations of marine sticklebacks. Grandparents were acclimated for two months during reproductive conditioning, whereas parents experienced developmental acclimation, allowing us to compare the fitness consequences of short-term vs. prolonged exposure to elevated temperature across multiple generations. We found that reproductive output of F1 adults was primarily determined by maternal developmental temperature, but carry-over effects from grandparental acclimation environments resulted in cumulative negative effects of elevated temperature on hatching success. In very early stages of growth, F2 offspring reached larger sizes in their respective paternal and grandparental environment down the paternal line, suggesting that other factors than just the paternal genome may be transferred between generations. In later growth stages, maternal and maternal granddam environments strongly influenced offspring body size, but in opposing directions, indicating that the mechanism(s) underlying the transfer of environmental information may have differed between acute and developmental acclimation experienced by the two generations. Taken together, our results suggest that the fitness consequences of parental and grandparental TGP are highly context dependent, but will play an important role in mediating some of the impacts of rapid climate change in this system. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  5. Perceptually optimal color reproduction

    NARCIS (Netherlands)

    Yendrikhovskij, S.N.; Blommaert, F.J.J.; Ridder, de H.; Rogowitz, B.E.; Pappas, T.N.

    1998-01-01

    What requirements do people place on optimal color reproduction of real-life scenes? We suggest that when people look at images containing familiar categories of objects, two primary factors shape their subjective impression of how optimal colors are reproduced: perceived naturalness and perceived

  6. Metabolomics reveals metabolic changes in male reproductive cells exposed to thirdhand smoke

    Science.gov (United States)

    Xu, Bo; Chen, Minjian; Yao, Mengmeng; Ji, Xiaoli; Mao, Zhilei; Tang, Wei; Qiao, Shanlei; Schick, Suzaynn F.; Mao, Jian-Hua; Hang, Bo; Xia, Yankai

    2015-10-01

    Thirdhand smoke (THS) is a new term for the toxins in cigarette smoke that linger in the environment long after the cigarettes are extinguished. The effects of THS exposure on male reproduction have not yet been studied. In this study, metabolic changes in male germ cell lines (GC-2 and TM-4) were analyzed after THS treatment for 24 h. THS-loaded chromatography paper samples were generated in a laboratory chamber system and extracted in DMEM. At a paper: DMEM ratio of 50 μg/ml, cell viability in both cell lines was normal, as measured by the MTT assay and markers of cytotoxicity, cell cycle, apoptosis and ROS production were normal as measured by quantitative immunofluorescence. Metabolomic analysis was performed on methanol extracts of GC-2 and TM-4 cells. Glutathione metabolism in GC-2 cells, and nucleic acid and ammonia metabolism in TM-4 cells, was changed significantly by THS treatment. RT-PCR analyses of mRNA for enzyme genes Gss and Ggt in GC-2 cells, and TK, SMS and Glna in TM-4 cells reinforced these findings, showing changes in the levels of enzymes involved in the relevant pathways. In conclusion, exposure to THS at very low concentrations caused distinct metabolic changes in two different types of male reproductive cell lines.

  7. Distribution and Biological Effects of Nanoparticles in the Reproductive System.

    Science.gov (United States)

    Liu, Ying; Li, Hongxia; Xiao, Kai

    2016-01-01

    Nanoparticles have shown great potential in biomedical applications such as imaging probes and drug delivery. However, the increasing use of nanoparticles has raised concerns about their adverse effects on human health and environment. Reproductive tissues and gametes represent highly delicate biological systems with the essential function of transmitting genetic information to the offspring, which is highly sensitive to environmental toxicants. This review aims to summarzie the penetration of physiological barriers (blood-testis barrier and placental barrier), distribution and biological effects of nanoparticles in the reproductive system, which is essential to control the beneficial effects of nanoparticles applications and to avoid their adverse effects on the reproductive system. We referred to a large number of relevant peer-reviewed research articles about the reproductive toxicity of nanoparticles. The comprehensive information was summarized into two parts: physiological barrier penetration and biological effects of nanoparticles in male or female reproductive system; distribution and metabolism of nanoparticles in the reproductive system. The representative examples were also presented in four tables. The in vitro and in vivo studies imply that some nanoparticles are able to cross the blood-testis barrier or placental barrier, and their penetration depends on the physicochemical characteristics of nanoparticles (e.g., composition, shape, particle size and surface coating). The toxicity assays indicate that nanoparticles might induce adverse physiological effects and impede fertility or embryogenesis. The barrier penetration, adverse physiological effects, distribution and metabolism are closely related to physicochemical characteristics of nanoparticles. Further systematic and mechanistic studies using well-characterized nanoparticles, relevant administration routes, and doses relevant to the expected exposure level are required to improve our

  8. Studies on the reproductive biology of downy brome (Bromus tectorum)

    International Nuclear Information System (INIS)

    Richardson, J.M.

    1986-01-01

    The ability of downy brome to successfully infest crop lands is partially due to its prolific nature. To better understand its reproductive biology, studies investigating (1) effects of temperature and photoperiod on flowering, (2) prevention of downy brome seed information with herbicides, and (3) effects of drought on reproduction, were conducted. Seedling vernalization was more effective than seed vernalization in promoting downy brome flowering. Vernalizing imbibed downy brome caryopses at 3 C for 0 to 30 days did not induce rapid flowering. Downy brome seedlings were exposed to six photoperiod/temperature treatments. After transfer to long days, plants from the short da/3 C treatment flowered within 30 days. DPX-Y6202 and fluazifop-butyl were tested for their ability to prevent seed formation in downy brome. Fluazifop-butyl prevented seed formation over a wider range of application rates and growth stages than did DPX-Y6202. Seed production was prevented most readily by herbicide applications made early in the reproductive cycle. Translocation of radiolabel was greater with 14 C-fluazifop-butyl than with 14 C-DPX-Y6202, particularly into developing spikelets. Microautoradiographic techniques were used to identify mechanisms involved in the prevention of downy brome seed formation by these herbicides. Tissue localization of both herbicides was similar. The highest concentration of radiolabel was found in developing pollen grains, suggesting that the herbicides prevented seed formation by interrupting pollen development or function. Water stress reduced apparent photosynthesis and increased diffusive resistance of flag leaves

  9. Nickel nanoparticles exposure and reproductive toxicity in healthy adult rats.

    Science.gov (United States)

    Kong, Lu; Tang, Meng; Zhang, Ting; Wang, Dayong; Hu, Ke; Lu, Weiqi; Wei, Chao; Liang, Geyu; Pu, Yuepu

    2014-11-17

    Nickel is associated with reproductive toxicity. However, the reproductive toxicity of nickel nanoparticles (Ni NPs) is unclear. Our goal was to determine the association between nickel nanoparticle exposure and reproductive toxicity. According to the one-generation reproductive toxicity standard, rats were exposed to nickel nanoparticles by gavage and we selected indicators including sex hormone levels, sperm motility, histopathology, and reproductive outcome etc. Experimental results showed nickel nanoparticles increased follicle stimulating hormone (FSH) and luteinizing hormone (LH), and lowered etradiol (E2) serum levels at a dose of 15 and 45 mg/kg in female rats. Ovarian lymphocytosis, vascular dilatation and congestion, inflammatory cell infiltration, and increase in apoptotic cells were found in ovary tissues in exposure groups. For male rats, the weights decreased gradually, the ratio of epididymis weight over body weight increased, the motility of rat sperm changed, and the levels of FSH and testosterone (T) diminished. Pathological results showed the shedding of epithelial cells of raw seminiferous tubule, disordered arrangement of cells in the tube, and the appearance of cell apoptosis and death in the exposure group. At the same time, Ni NPs resulted in a change of the reproductive index and the offspring development of rats. Further research is needed to elucidate exposure to human populations and mechanism of actions.

  10. Reproduction-Related Sound Production of Grasshoppers Regulated by Internal State and Actual Sensory Environment

    Science.gov (United States)

    Heinrich, Ralf; Kunst, Michael; Wirmer, Andrea

    2012-01-01

    The interplay of neural and hormonal mechanisms activated by entero- and extero-receptors biases the selection of actions by decision making neuronal circuits. The reproductive behavior of acoustically communicating grasshoppers, which is regulated by short-term neural and longer-term hormonal mechanisms, has frequently been used to study the cellular and physiological processes that select particular actions from the species-specific repertoire of behaviors. Various grasshoppers communicate with species- and situation-specific songs in order to attract and court mating partners, to signal reproductive readiness, or to fend off competitors. Selection and coordination of type, intensity, and timing of sound signals is mediated by the central complex, a highly structured brain neuropil known to integrate multimodal pre-processed sensory information by a large number of chemical messengers. In addition, reproductive activity including sound production critically depends on maturation, previous mating experience, and oviposition cycles. In this regard, juvenile hormone released from the corpora allata has been identified as a decisive hormonal signal necessary to establish reproductive motivation in grasshopper females. Both regulatory systems, the central complex mediating short-term regulation and the corpora allata mediating longer-term regulation of reproduction-related sound production mutually influence each other’s activity in order to generate a coherent state of excitation that promotes or suppresses reproductive behavior in respective appropriate or inappropriate situations. This review summarizes our current knowledge about extrinsic and intrinsic factors that influence grasshopper reproductive motivation, their representation in the nervous system and their integrative processing that mediates the initiation or suppression of reproductive behaviors. PMID:22737107

  11. Reproduction-related sound production of grasshoppers regulated by internal state and actual sensory environment

    Directory of Open Access Journals (Sweden)

    Ralf eHeinrich

    2012-06-01

    Full Text Available The interplay of neural and hormonal mechanisms activated by entero- and exteroreceptors biases the selection of actions by decision making neuronal circuits. The reproductive behaviour of acoustically communicating grasshoppers, which is regulated by short-term neural and longer-term hormonal mechanisms, has frequently been used to study the cellular and physiological processes that select particular actions from the species-specific repertoire of behaviours. Various grasshoppers communicate with species- and situation-specific songs in order to attract and court mating partners, to signal reproductive readiness or to fend off competitors. Selection and coordination of type, intensity and timing of sound signals is mediated by the central complex, a highly structured brain neuropil known to integrate multimodal pre-processed sensory information by a large number of chemical messengers. In addition, reproductive activity including sound production critically depends on maturation, previous mating experience and oviposition cycles. In this regard, juvenile hormone released from the corpora allata has been identified as a decisive hormonal signal necessary to establish reproductive motivation in grasshopper females. Both regulatory systems, the central complex mediating short-term regulation and the corpora allata mediating longer-term regulation of reproduction related sound production mutually influence each other’s activity in order to generate a coherent state of excitation that promotes or suppresses reproductive behaviour in respective appropriate or inappropriate situations.This review summarizes our current knowledge about extrinsic and intrinsic factors that influence grasshopper reproductive motivation, their representation in the nervous system and their integrative processing that mediates the initiation or suppression of reproductive behaviors.

  12. Study of multi-generational effects of a chronic exposure to ionizing radiations at a model organism: the nematode Caenorhabditis elegans

    International Nuclear Information System (INIS)

    Buisset-Goussen, Adeline

    2014-01-01

    The environmental risk assessment of chronic exposure to ionizing radiation (natural and ubiquitous phenomenon enhanced by human activities) has become a major concern. Few studies relating to chronic exposure over several generations - essential knowledge to better understand the disruption caused by ionizing radiation and its possible consequences on the population - exist. In addition, it has become necessary to understand the mechanisms of disturbances related to ionizing radiation at the molecular and cellular level. Without this mechanistic understanding, it is difficult to extrapolate the effects observed between the different levels of biological organization and between different species. The aim of this PhD was to study the multi-generational effects of chronic gamma radiation in an integrated manner (to the life history traits from the subcellular mechanisms) in a model organism, the nematode Caenorhabditis elegans. A two-step strategy was implemented. First, studying the effects of chronic gamma radiation on the life history traits of C. elegans was performed. The objective of this experiment was to test the hypothesis of an increase of the sensitivity according generations. For that, three generations have been exposed to different dose rates. In parallel, two generations have been placed in 'control' environment after parental exposure to test a possible transmission of maternal effects. The second part of this thesis aimed to characterize the different subcellular mechanisms that could explain the observed effects on the life history traits after multi-generational exposure. The results showed that (i) the cumulative number of larvae was the most sensitive endpoint to gamma radiation, (ii) an increase in radiosensitivity was observed over three exposed generations and (iii) the effects of the parental generation were transmitted to the non-exposed generations. An increase in apoptosis, a reduction in the stock of sperm, and to a lesser

  13. Growth and reproductive investment of introduced Pacific oysters

    NARCIS (Netherlands)

    Cardoso, J.F.M.F.; Peralta, N.R.E.; Machado, J.P.; van der Veer, H.W.

    2013-01-01

    Growth and reproductive investment of cultured Pacific oysters Crassostrea gigas were studied in two south-western European estuaries: the Ria de Ribadeo in Spain and the Ria Formosa in Portugal. Developing gonads were found in individuals >23.5 mm shell length in the Ria Formosa and >27.5 mm shell

  14. Age differences at sexual debut and subsequent reproductive health: Is there a link?

    Directory of Open Access Journals (Sweden)

    Reynolds Heidi

    2008-10-01

    Full Text Available Abstract Background Experiences at sexual debut may be linked to reproductive health later in life. Additionally, young women with older sexual partners may be at greater risk for HIV and sexually transmitted infections. This study examines sexual debut with an older partner and subsequent reproductive health outcomes among 599 sexually experienced women aged 15–24 who utilized voluntary counseling and testing or reproductive health services in Port-au-Prince, Haiti. Methods Logistic regression models, controlling for socioeconomic and demographic factors, examined whether age differences at first sex were significantly associated with STI diagnosis in the previous 12 months and family planning method use at last intercourse. Results Sixty-five percent of women reported sexual initiation with a partner younger or less than 5 years older, 28% with a partner 5 to 10 years older, and 7% with a partner 10 or more years older. There was a trend towards decreased likelihood of recent use of family planning methods in women who had first sexual intercourse with a partner 5 to 9 years older compared to women with partners who were younger or less than 5 years older. Age differences were not linked to recent STI diagnosis. Conclusion Programs focusing on delaying sexual debut should consider age and gender-based power differentials between younger women and older men. Future research should examine whether wide age differences at sexual debut are predictive of continued involvement in cross-generational relationships and risky sexual behaviors and explore the mechanisms by which cross-generational first sex and subsequent reproductive health may be connected.

  15. Reproduction and longevity of Supputius cincticeps (Het.: Pentatomidae) fed with larvae of Zophobas confusa, Tenebrio molitor (Col.: Tenebrionidae) or Musca domestica (Dip.: Muscidae)

    OpenAIRE

    Zanuncio,José Cola; Beserra,Eduardo Barbosa; Molina-Rugama,Adrián José; Zanuncio,Teresinha Vinha; Pinon,Tobias Baruc Moreira; Maffia,Vanessa Pataro

    2005-01-01

    Reproduction and longevity of Supputius cincticeps (Stål) (Heteroptera: Pentatomidae) fed on Zophobas confusa Gebien, Tenebrio molitor L. (Coleoptera: Tenebrionidae) or Musca domestica (L.) (Diptera: Muscidae) larvae were studied during two generations at 24.7 ± 1.1ºC, 70 ± 10% R.H. and 12 h of photophase. Body weight of newly-emerged adults, oviposition period, number of egg masses, total number of eggs and longevity of S. cincticeps were higher when fed on Z. confusa or T. mol...

  16. DEP and AFO regulate reproductive habit in rice.

    Directory of Open Access Journals (Sweden)

    Kejian Wang

    2010-01-01

    Full Text Available Sexual reproduction is essential for the life cycle of most angiosperms. However, pseudovivipary is an important reproductive strategy in some grasses. In this mode of reproduction, asexual propagules are produced in place of sexual reproductive structures. However, the molecular mechanism of pseudovivipary still remains a mystery. In this work, we found three naturally occurring mutants in rice, namely, phoenix (pho, degenerative palea (dep, and abnormal floral organs (afo. Genetic analysis of them indicated that the stable pseudovivipary mutant pho was a double mutant containing both a Mendelian mutation in DEP and a non-Mendelian mutation in AFO. Further map-based cloning and microarray analysis revealed that dep mutant was caused by a genetic alteration in OsMADS15 while afo was caused by an epigenetic mutation in OsMADS1. Thus, OsMADS1 and OsMADS15 are both required to ensure sexual reproduction in rice and mutations of them lead to the switch of reproductive habit from sexual to asexual in rice. For the first time, our results reveal two regulators for sexual and asexual reproduction modes in flowering plants. In addition, our findings also make it possible to manipulate the reproductive strategy of plants, at least in rice.

  17. Developmental and Reproductive Effects of SE5-OH: An Equol-Rich Soy-Based Ingredient

    International Nuclear Information System (INIS)

    Matulka, R.A.; Burdock, G.; Matsuura, I.; Uesugi, T.; Ueno, T.

    2009-01-01

    Consumption of the isoflavones daidzein, genistein, glycitein, and their structural analogues is generally considered beneficial to human health. Equol is not found in soy, but is converted from daidzein by human gut bacterial flora. Research indicates that between 30-50% of the population is capable of converting daidzein to equol; therefore, there has been recent development of a new equol-rich functional food that relies on bacterial conversion of daidzein to equol under strictly controlled conditions. Therefore, a new equol-rich soy product (SE5-OH) has been developed, based on the bacterial conversion of daidzein; and its reproductive and developmental toxicity has been evaluated in a two-generation study and a developmental toxicity study with Sprague-Dawley rats at dose levels of 200, 1000, and 2000 mg/kg/day by gavage. SE5-OH contains approximately 0.65% equol, 0.024% daidzein, 0.022% genistein, and 0.30% glycitein. From the reproductive study, the no-observed-adverse-effect-level (NOAEL) for SE5-OH determined for both male and female rats is 1000 mg/kg/day (6.5 mg equol/kg/day). In the developmental toxicity phase of the study, no effects by SE5-OH were found in the embryo-fetus at any of the doses tested. The NOAEL for developmental effects of SE5-OH is 2000 mg/kg/day (13 mg equol/kg/day).

  18. Recent developments in genetics and medically assisted reproduction: from research to clinical applications.

    Science.gov (United States)

    Harper, J C; Aittomäki, K; Borry, P; Cornel, M C; de Wert, G; Dondorp, W; Geraedts, J; Gianaroli, L; Ketterson, K; Liebaers, I; Lundin, K; Mertes, H; Morris, M; Pennings, G; Sermon, K; Spits, C; Soini, S; van Montfoort, A P A; Veiga, A; Vermeesch, J R; Viville, S; Macek, M

    2018-01-01

    Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.

  19. Life span and reproductive cost explain interspecific variation in the optimal onset of reproduction.

    Science.gov (United States)

    Mourocq, Emeline; Bize, Pierre; Bouwhuis, Sandra; Bradley, Russell; Charmantier, Anne; de la Cruz, Carlos; Drobniak, Szymon M; Espie, Richard H M; Herényi, Márton; Hötker, Hermann; Krüger, Oliver; Marzluff, John; Møller, Anders P; Nakagawa, Shinichi; Phillips, Richard A; Radford, Andrew N; Roulin, Alexandre; Török, János; Valencia, Juliana; van de Pol, Martijn; Warkentin, Ian G; Winney, Isabel S; Wood, Andrew G; Griesser, Michael

    2016-02-01

    Fitness can be profoundly influenced by the age at first reproduction (AFR), but to date the AFR-fitness relationship only has been investigated intraspecifically. Here, we investigated the relationship between AFR and average lifetime reproductive success (LRS) across 34 bird species. We assessed differences in the deviation of the Optimal AFR (i.e., the species-specific AFR associated with the highest LRS) from the age at sexual maturity, considering potential effects of life history as well as social and ecological factors. Most individuals adopted the species-specific Optimal AFR and both the mean and Optimal AFR of species correlated positively with life span. Interspecific deviations of the Optimal AFR were associated with indices reflecting a change in LRS or survival as a function of AFR: a delayed AFR was beneficial in species where early AFR was associated with a decrease in subsequent survival or reproductive output. Overall, our results suggest that a delayed onset of reproduction beyond maturity is an optimal strategy explained by a long life span and costs of early reproduction. By providing the first empirical confirmations of key predictions of life-history theory across species, this study contributes to a better understanding of life-history evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  20. Effect of reproductive disorders on productivity and reproductive efficiency of dromedary she-camels in relation to cytokine concentration.

    Science.gov (United States)

    El-Malky, O M; Mostafa, T H; Abd El-Salaam, A M; Ayyat, M S

    2018-06-01

    This experiment was conducted to study the effect of reproductive disorders on reproductive efficiency and milk production in relation with pro-inflammatory cytokines in dromedary she-camels. Total of 20 late pregnant Maghrabi she-camels, aging 6-9 years, weighing 420-550 kg, and between the second and third parities were divided into two groups. Animals in the first group (n = 12) showed normal reproductive status (G 1 ) at parturition, while those in the second one (n = 8) were suffered from reproductive disorders after parturition (G 2 ). Results showed that during pre-partum, red blood cells (RBCs) count decreased (P ≤ 0.05), while white blood cells (WBCs), packed cell volume (PCV) value, and neutrophils percentage increased (P ≤ 0.05) in G 2 than in G 1 . Percentages of monocytes, basophils, and eosinophils as well as hemoglobin concentration did not differ significantly (P ≥ 0.05) in G1 and G2. During postpartum period, the same results were noticed in addition to increase (P ≤ 0.05) in eosinophil and decrease (P ≤ 0.05) in basophils percentages. During prepartum period, concentration of total proteins, albumin (AL) and IGF-1decreased (P ≤ 0.05), cholesterol concentration, and activity of AST and ALT were higher (P ≤ 0.05) in G 2 than in G 1 . Globulin (GL), AL: GL ratio, glucose, urea-N, creatinine, and triglyceride concentrations did not differ significantly in G 1 and G 2 . During postpartum period, the same results were noticed with decrease (P ≤ 0.05) in GL and glucose concentrations in G 2 as compared to G 1 . Concentration of all pro-inflammatory cytokines, including IL-6, IL-10, and IFN-γ, was higher (P ≤ 0.05) in G 2 than in G 1 at different peri-parturient times. Milk yield, days in milk, protein and lactose percentages, and IgG concentration were higher (P ≤ 0.05) in G 1 than in G 2 . Fat, total solids, solid non-fat, and ash percentages did not show any significant differences

  1. Activins in reproductive biology and beyond.

    Science.gov (United States)

    Wijayarathna, R; de Kretser, D M

    2016-04-01

    Activins are members of the pleiotrophic family of the transforming growth factor-beta (TGF-β) superfamily of cytokines, initially isolated for their capacity to induce the release of FSH from pituitary extracts. Subsequent research has demonstrated that activins are involved in multiple biological functions including the control of inflammation, fibrosis, developmental biology and tumourigenesis. This review summarizes the current knowledge on the roles of activin in reproductive and developmental biology. It also discusses interesting advances in the field of modulating the bioactivity of activins as a therapeutic target, which would undoubtedly be beneficial for patients with reproductive pathology. A comprehensive literature search was carried out using PUBMED and Google Scholar databases to identify studies in the English language which have contributed to the advancement of the field of activin biology, since its initial isolation in 1987 until July 2015. 'Activin', 'testis', 'ovary', 'embryonic development' and 'therapeutic targets' were used as the keywords in combination with other search phrases relevant to the topic of activin biology. Activins, which are dimers of inhibin β subunits, act via a classical TGF-β signalling pathway. The bioactivity of activin is regulated by two endogenous inhibitors, inhibin and follistatin. Activin is a major regulator of testicular and ovarian development. In the ovary, activin A promotes oocyte maturation and regulates granulosa cell steroidogenesis. It is also essential in endometrial repair following menstruation, decidualization and maintaining pregnancy. Dysregulation of the activin-follistatin-inhibin system leads to disorders of female reproduction and pregnancy, including polycystic ovary syndrome, ectopic pregnancy, miscarriage, fetal growth restriction, gestational diabetes, pre-eclampsia and pre-term birth. Moreover, a rise in serum activin A, accompanied by elevated FSH, is characteristic of female

  2. Two schemes for rapid generation of digital video holograms using PC cluster

    Science.gov (United States)

    Park, Hanhoon; Song, Joongseok; Kim, Changseob; Park, Jong-Il

    2017-12-01

    Computer-generated holography (CGH), which is a process of generating digital holograms, is computationally expensive. Recently, several methods/systems of parallelizing the process using graphic processing units (GPUs) have been proposed. Indeed, use of multiple GPUs or a personal computer (PC) cluster (each PC with GPUs) enabled great improvements in the process speed. However, extant literature has less often explored systems involving rapid generation of multiple digital holograms and specialized systems for rapid generation of a digital video hologram. This study proposes a system that uses a PC cluster and is able to more efficiently generate a video hologram. The proposed system is designed to simultaneously generate multiple frames and accelerate the generation by parallelizing the CGH computations across a number of frames, as opposed to separately generating each individual frame while parallelizing the CGH computations within each frame. The proposed system also enables the subprocesses for generating each frame to execute in parallel through multithreading. With these two schemes, the proposed system significantly reduced the data communication time for generating a digital hologram when compared with that of the state-of-the-art system.

  3. Reproductive strategy, sexual development and attraction to facial characteristics

    OpenAIRE

    Cornwell, R. Elisabeth; Law Smith, Miriam J; Boothroyd, Lynda G; Moore, Fhionna R; Davis, Hasker P; Stirrat, Michael; Tiddeman, Bernard; Perrett, David I

    2006-01-01

    Sexual reproduction strategies vary both between and within species in the level of investment in offspring. Life-history theories suggest that the rate of sexual maturation is critically linked to reproductive strategy, with high investment being associated with few offspring and delayed maturation. For humans, age of puberty and age of first sex are two developmental milestones that have been associated with reproductive strategies. Stress during early development can retard or accelerate s...

  4. Urinary Phthalate Metabolite Concentrations and Reproductive Outcomes among Women Undergoing in Vitro Fertilization: Results from the EARTH Study.

    Science.gov (United States)

    Hauser, Russ; Gaskins, Audrey J; Souter, Irene; Smith, Kristen W; Dodge, Laura E; Ehrlich, Shelley; Meeker, John D; Calafat, Antonia M; Williams, Paige L

    2016-06-01

    Evidence from both animal and human studies suggests that exposure to phthalates may be associated with adverse female reproductive outcomes. We evaluated the associations between urinary concentrations of phthalate metabolites and outcomes of assisted reproductive technologies (ART). This analysis included 256 women enrolled in the Environment and Reproductive Health (EARTH) prospective cohort study (2004-2012) who provided one to two urine samples per cycle before oocyte retrieval. We measured 11 urinary phthalate metabolites [mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MBP), monobenzyl phthalate (MBzP), monoethyl phthalate (MEP), monocarboxyisooctyl phthalate (MCOP), monocarboxyisononyl phthalate (MCNP), and mono(3-carboxypropyl) phthalate (MCPP)]. We used generalized linear mixed models to evaluate the association of urinary phthalate metabolites with in vitro fertilization (IVF) outcomes, accounting for multiple IVF cycles per woman. In multivariate models, women in the highest as compared with lowest quartile of MEHP, MEHHP, MEOHP, MECPP, ΣDEHP (MEHP + MEHHP + MEOHP + MECPP), and MCNP had lower oocyte yield. Similarly, the number of mature (MII) oocytes retrieved was lower in the highest versus lowest quartile for these same phthalate metabolites. The adjusted differences (95% CI) in proportion of cycles resulting in clinical pregnancy and live birth between women in the fourth versus first quartile of ΣDEHP were -0.19 (-0.29, -0.08) and -0.19 (-0.28, -0.08), respectively, and there was also a lower proportion of cycles resulting in clinical pregnancy and live birth for individual DEHP metabolites. Urinary concentrations of DEHP metabolites were inversely associated with oocyte yield, clinical pregnancy, and live birth following ART. Hauser R, Gaskins AJ, Souter I, Smith

  5. Variation in male reproductive longevity across traditional societies.

    Directory of Open Access Journals (Sweden)

    Lucio Vinicius

    Full Text Available Most accounts of human life history propose that women have short reproductive spans relative to their adult lifespans, while men not only remain fertile but carry on reproducing until late life. Here we argue that studies have overlooked evidence for variation in male reproductive ageing across human populations. We apply a Bayesian approach to census data from Agta hunter-gatherers and Gambian farmers to show that long post-reproductive lifespans characterise not only women but also males in some traditional human populations. We calculate three indices of reproductive ageing in men (oldest age at reproduction, male late-life reproduction, and post-reproductive representation and identify a continuum of male reproductive longevity across eight traditional societies ranging from !Kung, Hadza and Agta hunter-gatherers exhibiting low levels of polygyny, early age at last reproduction and long post-reproductive lifespans, to male Gambian agriculturalists and Turkana pastoralists showing higher levels of polygyny, late-life reproduction and shorter post-reproductive lifespans. We conclude that the uniquely human detachment between rates of somatic senescence and reproductive decline, and the existence of post-reproductive lifespans, are features of both male and female life histories, and therefore not exclusive consequences of menopause.

  6. Knowledge, Attitude and Practices Study on Reproductive Health ...

    African Journals Online (AJOL)

    Erah

    2009-12-04

    Dec 4, 2009 ... perception, STIs and HIV/AIDS, family planning, male-female relationship, and vulnerability to sexual violence. The data ... abnormality (Center for Reproductive Law and ...... the example of Ghanaian prostitutes in the.

  7. A comparative observational study on the reproductive performance ...

    African Journals Online (AJOL)

    The reproductive performance of cows with post parturient metritis treated systemically with long-acting oxytetra- ..... of voluntary waiting period before breeding, heat detec- ... then these results stress the variability of the response among.

  8. A novel quantitative approach to women's reproductive strategies.

    Directory of Open Access Journals (Sweden)

    Fritha H Milne

    Full Text Available The patterned way in which individuals allocate finite resources to various components of reproduction (e.g. mating effort, reproductive timing and parental investment is described as a reproductive strategy. As energy is limited, trade-offs between and within aspects of reproductive strategies are expected. The first aim of this study was to derive aspects of reproductive strategies using complete reproductive histories from 718 parous Western Australian women. Factor analysis using a subset of these participants resulted in six factors that represented 'short-term mating strategy', 'early onset of sexual activity', 'reproductive output', 'timing of childbearing', 'breastfeeding', and 'child spacing'. This factor structure was internally validated by replication using a second independent subset of the data. The second aim of this study examined trade-offs between aspects of reproductive strategies derived from aim one. Factor scores calculated for each woman were incorporated in generalised linear models and interaction terms were employed to examine the effect of mating behaviour on the relationships between reproductive timing, parental investment and overall reproductive success. Early sexual activity correlates with early reproductive onset for women displaying more long-term mating strategies. Women with more short-term mating strategies exhibit a trade-off between child quantity and child quality not observed in women with a long-term mating strategy. However, women with a short-term mating strategy who delay reproductive timing exhibit levels of parental investment (measured as breastfeeding duration per child similar to that of women with long-term mating strategies. Reproductive delay has fitness costs (fewer births for women displaying more short-term mating strategies. We provide empirical evidence that reproductive histories of contemporary women reflect aspects of reproductive strategies, and associations between these strategic

  9. Mode of delivery and subsequent reproductive patterns. A national follow-up study

    DEFF Research Database (Denmark)

    Fussing-Clausen, Caroline; Geirsson, Reynir T; Hansen, Thomas

    2014-01-01

    OBJECTIVE: To investigate associations between mode of delivery and subsequent reproductive outcomes. DESIGN: Cohort study. POPULATION: Women with term singleton live births from 1987 to 2009. SETTING: Denmark, birth registration data. METHODS: Women with a first singleton delivery after 37 weeks...

  10. Color reproduction software for a digital still camera

    Science.gov (United States)

    Lee, Bong S.; Park, Du-Sik; Nam, Byung D.

    1998-04-01

    We have developed a color reproduction software for a digital still camera. The image taken by the camera was colorimetrically reproduced on the monitor after characterizing the camera and the monitor, and color matching between two devices. The reproduction was performed at three levels; level processing, gamma correction, and color transformation. The image contrast was increased after the level processing adjusting the level of dark and bright portions of the image. The relationship between the level processed digital values and the measured luminance values of test gray samples was calculated, and the gamma of the camera was obtained. The method for getting the unknown monitor gamma was proposed. As a result, the level processed values were adjusted by the look-up table created by the camera and the monitor gamma correction. For a color transformation matrix for the camera, 3 by 3 or 3 by 4 matrix was used, which was calculated by the regression between the gamma corrected values and the measured tristimulus values of each test color samples the various reproduced images were displayed on the dialogue box implemented in our software, which were generated according to four illuminations for the camera and three color temperatures for the monitor. An user can easily choose he best reproduced image comparing each others.

  11. Reproductive toxicity: Male and female reproductive systems as targets for chemical injury

    Energy Technology Data Exchange (ETDEWEB)

    Mattison, D.R.; Plowchalk, D.R.; Meadows, M.J.; Al-Juburi, A.Z.; Gandy, J.; Malek, A. (Univ. of Arkansas for Medical Sciences, Little Rock (USA))

    1990-03-01

    On the basis of current knowledge of reproductive biology and toxicology, it is apparent that chemicals affecting reproduction may elicit their effects at a number of sites in both the male and the female reproductive system. This multiplicity of targets is attributable to the dynamic nature of the reproductive system, in which the hypothalamic-pituitary-gonadal axis is controlled by precise positive and negative feedback mechanisms among its components. Interference by a xenobiotic at any level in either the male or the female reproductive system may ultimately impair hypothalamic or pituitary function. Normal gonadal processes such as spermatogenesis or oogenesis, ejaculation or ovulation, hormone production by Leydig or granulosa cells, and the structure or function of the accessory reproductive structures (e.g., epididymis, fallopian tube) also appear vulnerable to xenobiotics. The reproductive system is a complex one that requires local and circulating hormones for control. This brief review illustrates a system for characterizing the mechanism of action of reproductive toxicants, as well as for defining the sites available for disruption of reproduction. Unfortunately, at present, data addressing the actual vulnerability of reproduction are sorely lacking. However, when experiments have been conducted and combined with epidemiologic data or clinical observation, it has been possible to demonstrate impairment of reproductive processes by xenobiotics. The role of environmental exposure to xenobiotics in the increase in infertility that has been observed remains to be defined. 87 references.

  12. Reproductive Health CHOICES for Young Adults with Sickle Cell Disease or Trait: Randomized Controlled Trial Outcomes over Two Years.

    Science.gov (United States)

    Gallo, Agatha M; Wilkie, Diana J; Yao, Yingwei; Molokie, Robert E; Stahl, Christiane; Hershberger, Patricia E; Zhao, Zhongsheng; Suarez, Marie L; Johnson, Bonnye; Angulo, Rigoberto; Carrasco, Jesus; Angulo, Veronica; Thompson, Alexis A

    2016-04-01

    Interventions to assist reproductive health decision-making in populations affected by sickle cell disease (SCD) or trait (SCT) lack proven efficacy over time. Our aim was to compare effects of CHOICES, a Web-based multimedia education program on implementing informed reproductive plans, and usual care education (e-Book) on reproductive knowledge, intention, and behavior over 24 months. We randomized 234 participants with SCD (n = 138) or SCT (n = 96) (age 18-35 years, 35 % male, 94 % African American) to CHOICES and e-Book groups. Participants completed a sickle cell-specific reproductive measure before and four times after the intervention (6, 12, 18 and 24 months). Compared to the e-Book group the CHOICES group had significantly more improvement in knowledge over time (p = .004) but not intention (p = .18) or behavior (p = .69). At baseline, 114 (48.7 %) participants reported having partners who would not put the couple at risk for their children inheriting SCD. Of the 116 (49.6 %) at-risk participants, a higher poroportion of those who were in the CHOICES group chose partners that reduced their risk by the last visit than the e-Book group (p = .04). Study findings provide important insights for designing a national trial of the CHOICES intervention focusing on subjects whose partner status puts them at risk for having a child with SCD.

  13. Central Pathways Integrating Metabolism and Reproduction in Teleosts

    Science.gov (United States)

    Shahjahan, Md.; Kitahashi, Takashi; Parhar, Ishwar S.

    2014-01-01

    Energy balance plays an important role in the control of reproduction. However, the cellular and molecular mechanisms connecting the two systems are not well understood especially in teleosts. The hypothalamus plays a crucial role in the regulation of both energy balance and reproduction, and contains a number of neuropeptides, including gonadotropin-releasing hormone (GnRH), orexin, neuropeptide-Y, ghrelin, pituitary adenylate cyclase-activating polypeptide, α-melanocyte stimulating hormone, melanin-concentrating hormone, cholecystokinin, 26RFamide, nesfatin, kisspeptin, and gonadotropin-inhibitory hormone. These neuropeptides are involved in the control of energy balance and reproduction either directly or indirectly. On the other hand, synthesis and release of these hypothalamic neuropeptides are regulated by metabolic signals from the gut and the adipose tissue. Furthermore, neurons producing these neuropeptides interact with each other, providing neuronal basis of the link between energy balance and reproduction. This review summarizes the advances made in our understanding of the physiological roles of the hypothalamic neuropeptides in energy balance and reproduction in teleosts, and discusses how they interact with GnRH, kisspeptin, and pituitary gonadotropins to control reproduction in teleosts. PMID:24723910

  14. A comparison of second and third generations combined oral contraceptive pills' effect on mood.

    Science.gov (United States)

    Shahnazi, Mahnaz; Farshbaf Khalili, Azizeh; Ranjbar Kochaksaraei, Fatemeh; Asghari Jafarabadi, Mohammad; Gaza Banoi, Kamal; Nahaee, Jila; Bayati Payan, Somayeh

    2014-08-01

    Most women taking combined oral contraceptives (COCs) are satisfied with their contraceptive method. However, one of the most common reasons reported for discontinuation of combined oral contraceptives (COCs) is mood deterioration. This study aimed to compare effects of the second and third generation oral contraceptive pills on the mood of reproductive women. This randomized, double-blind, controlled clinical trial was conducted in reproductive women at health centers in Tehran, Iran. Participants were randomized into the second and third generation oral contraceptive groups. Positive and negative moods were recorded using positive affect, negative affect scale (PANAS) tools at the end the second and fourth months of the study. Data analysis was carried out using ANOVA and P Values pills. The second generation oral contraceptive pills resulted in a decrease in positive mood (95% CI: 43.39 to 38.32 in second month and 43.39 to 26.05 in four month) and increase in negative mood (95% CI: 14.23 to 22.04 in second month and 14.23 to 32.26 in four month - P pills have a better effect on mood in women in reproductive ages than the second generation pills. It can be recommended as a proper combined oral contraceptive in Iran.

  15. A Comparison of Second and Third Generations Combined Oral Contraceptive Pills’ Effect on Mood

    Science.gov (United States)

    Shahnazi, Mahnaz; Farshbaf Khalili, Azizeh; Ranjbar Kochaksaraei, Fatemeh; Asghari Jafarabadi, Mohammad; Gaza Banoi, Kamal; Nahaee, Jila; Bayati Payan, Somayeh

    2014-01-01

    Background: Most women taking combined oral contraceptives (COCs) are satisfied with their contraceptive method. However, one of the most common reasons reported for discontinuation of combined oral contraceptives (COCs) is mood deterioration. Objectives: This study aimed to compare effects of the second and third generation oral contraceptive pills on the mood of reproductive women. Materials and Methods: This randomized, double-blind, controlled clinical trial was conducted in reproductive women at health centers in Tehran, Iran. Participants were randomized into the second and third generation oral contraceptive groups. Positive and negative moods were recorded using positive affect, negative affect scale (PANAS) tools at the end the second and fourth months of the study. Data analysis was carried out using ANOVA and P Values pills. The second generation oral contraceptive pills resulted in a decrease in positive mood (95% CI: 43.39 to 38.32 in second month and 43.39 to 26.05 in four month) and increase in negative mood (95% CI: 14.23 to 22.04 in second month and 14.23 to 32.26 in four month - P pills have a better effect on mood in women in reproductive ages than the second generation pills. It can be recommended as a proper combined oral contraceptive in Iran. PMID:25389478

  16. Male Reproductive System

    Science.gov (United States)

    ... With the Male Reproductive System Print en español Sistema reproductor masculino Reproduction All living things reproduce. Reproduction — ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on KidsHealth® is for ...

  17. Persistent organic pollutants and male reproductive health

    Directory of Open Access Journals (Sweden)

    Anne Vested

    2014-02-01

    Full Text Available Environmental contaminants such as persistent organic pollutants (POPs are man-made bioaccumulative compounds with long half-lives that are found throughout the world as a result of heavy use in a variety of consumer products during the twentieth century. Wildlife and animal studies have long suggested adverse effects of exposure to these compounds on human reproductive health, which, according to the endocrine disrupter hypothesis, are ascribed to the compounds' potential to interfere with endocrine signaling, especially when exposure occurs during certain phases of fetal and childhood development. An extensive number of epidemiological studies have addressed the possible effects of exposure to POPs on male reproductive health, but the results are conflicting. Thus far, most studies have focused on investigating exposure and the different reproductive health outcomes during adulthood. Some studies have addressed the potential harmful effects of fetal exposure with respect to malformations at birth and/or reproductive development, whereas only a few studies have been able to evaluate whether intrauterine exposure to POPs has long-term consequences for male reproductive health with measurable effects on semen quality markers and reproductive hormone levels in adulthood. Humans are not exposed to a single compound at a time, but rather, to a variety of different substances with potential divergent hormonal effects. Hence, how to best analyze epidemiological data on combined exposures remains a significant challenge. This review on POPs will focus on current knowledge regarding the potential effects of exposure to POPs during fetal and childhood life and during adulthood on male reproductive health, including a critical revision of the endocrine disruption hypothesis, a comment on pubertal development as part of reproductive development and a comment on how to account for combined exposures in epidemiological research.

  18. Reproductive hacking. A male seminal protein acts through intact reproductive pathways in female Drosophila.

    Science.gov (United States)

    Rubinstein, C Dustin; Wolfner, Mariana F

    2014-01-01

    Seminal proteins are critical for reproductive success in all animals that have been studied. Although seminal proteins have been identified in many taxa, and female reproductive responses to receipt of these proteins have been documented in several, little is understood about the mechanisms by which seminal proteins affect female reproductive physiology. To explore this topic, we investigated how a Drosophila seminal protein, ovulin, increases ovulation rate in mated females. Ovulation is a relatively simple physiological process, with known female regulators: previous studies have shown that ovulation rate is promoted by the neuromodulator octopamine (OA) in D. melanogaster and other insects. We found that ovulin stimulates ovulation by increasing OA signaling in the female. This finding supports a model in which a male seminal protein acts through "hacking" a well-conserved, regulatory system females use to adjust reproductive output, rather than acting downstream of female mechanisms of control or in parallel pathways altogether. We also discuss similarities between 2 forms of intersexual control of behavior through chemical communication: seminal proteins and pheromones.

  19. Factors determining the reproductive potential of Pelibuey sheep: Effects of season and parturition on reproductive performance

    International Nuclear Information System (INIS)

    Gonzalez Reyna, A.; Ortega Rivas, E.; Murphy, B.D.

    1990-01-01

    The Pelibuey sheep in Mexico are known for their hardiness and reproductive capacity: as a result they represent a reliable source of animal protein especially at the village level. Although their reproductive parameters have been studied, little endocrinological information is available. The objectives of the present study were to characterize the annual reproductive cycle in the Pelibuey ram and ewe, and to study methods of shortening the interval from parturition to first oestrus in lactating post-partum ewes. Under conditions of nutrition and management prevailing in this study, season affected levels of testosterone and LH in the male and LH in the female. Season also influenced oestrous activity, the proportion of ewes ovulating per month and the mean ovulation rate per month. The results indicated that the majority of Pelibuey ewes cycle throughout the year but exhibit reduced gonadal activity during late winter. Pelibuey rams appear to have longer periods of reduced activity (during late autumn and winter), although testosterone levels suggest that rams return to their full reproductive activity earlier (late winter) than ewes. (author). 30 refs, 7 figs, 3 tabs

  20. Unrelated secondary reproductives in the neotropical termite Silvestritermes euamignathus (Isoptera: Termitidae)

    Science.gov (United States)

    Haifig, Ives; Vargo, Edward L.; Labadie, Paul; Costa-Leonardo, Ana Maria

    2016-02-01

    A termite colony is usually founded by a pair of alates, the primary reproductives, which produce all the nestmates. In some species, secondary reproductives appear to either replace the primaries or supplement colony reproduction. In termites, secondary reproductives are generally ergatoids derived from workers or nymphoids derived from nymphs. Silvestritermes euamignathus is a termite species that forms multiple nymphoid reproductives, and to date it was hypothesized that these secondary reproductives were the progeny of the primary founding reproductives. We developed markers for 12 microsatellite loci and used COI mitochondrial DNA (mtDNA) to genotype 59 nymphoid neotenics found in a colony of S. euamignathus to test this hypothesis. Our results showed that nymphoids of S. euamignathus are not all siblings. The microsatellite analysis suggests that the secondary reproductives derived from a minimum of four different pairs of reproductives belonging to at least two different matrilines. This is the first record of non-sibling secondary reproductives occupying the same nest in a higher termite. These unrelated reproductives might be the result of either pleometrotic colony foundation or colony fusion.

  1. A Longitudinal Study of Families Formed Through Reproductive Donation: Parent-Adolescent Relationships and Adolescent Adjustment at Age 14

    OpenAIRE

    Golombok, Susan; Ilioi, Elena; Blake, Lucy; Roman, Gabriela; Jadva, Vasanti

    2017-01-01

    The aim of the 6th phase of this longitudinal study was to establish whether children born through assisted reproduction involving reproductive donation were at risk for psychological problems following the transition to adolescence at age 14 and, if so, to examine the nature of these problems and the mechanisms involved. Eighty-seven families formed through reproductive donation, including 32 donor insemination families, 27 egg donation families, and 28 surrogacy families, were compared with...

  2. Effects of tartrazine on exploratory behavior in a three-generation toxicity study in mice.

    Science.gov (United States)

    Tanaka, Toyohito; Takahashi, Osamu; Oishi, Shinshi; Ogata, Akio

    2008-10-01

    Tartrazine was given to mice in the diet at levels of 0 (control), 0.05%, 0.15%, and 0.45% from 5 weeks of age of the F(0) generation to 9 weeks of age of the F(2) generation, and selected reproductive and neurobehavioral parameters were measured. In the F(1) generation, the development of swimming direction at postnatal day (PND) 7 was accelerated significantly in male offspring in a dose-related manner. Surface righting at PND 7 was affected significantly in female offspring in dose-related manner. Several variables in exploratory behavior showed significant tendencies to be affected in the treatment groups in male offspring at 3 weeks of age. In the F(2) generation, the development of swimming direction at PND 7 was accelerated significantly in the high-dosed group in male offspring. Time taken of olfactory orientation at PND 14 was accelerated significantly in male offspring in a dose-related manner. Several variables in exploratory behavior showed significant tendencies to be affected in the treatment groups in male offspring at 3 weeks of age, and in males at 8 weeks of age. The dose levels of tartrazine in the present study produced a few adverse effects on neurobehavioral parameters throughout generations in mice.

  3. Color reproduction system based on color appearance model and gamut mapping

    Science.gov (United States)

    Cheng, Fang-Hsuan; Yang, Chih-Yuan

    2000-06-01

    By the progress of computer, computer peripherals such as color monitor and printer are often used to generate color image. However, cross media color reproduction by human perception is usually different. Basically, the influence factors are device calibration and characterization, viewing condition, device gamut and human psychology. In this thesis, a color reproduction system based on color appearance model and gamut mapping is proposed. It consists of four parts; device characterization, color management technique, color appearance model and gamut mapping.

  4. Social Reproduction and Sex in German Primary Schools

    Science.gov (United States)

    Smith, Daniel Scott; Wendt, Heike; Kasper, Daniel

    2017-01-01

    To understand the relationship between social background and sex in schooling, we use Bourdieu's theory of social reproduction and a feminist perspective of gender as practice. We pose two questions: (1) What is the relationship between economic and cultural capital and achievement for 4th-grade females versus males studying in Germany? (2) Is the…

  5. Parents face quantity-quality trade-offs between reproduction and investment in offspring in Iceland.

    Science.gov (United States)

    Lynch, Robert Francis

    2016-05-01

    How to optimally allocate time, energy and investment in an effort to maximize one's reproductive success is a fundamental problem faced by all organisms. This effort is complicated when the production of each additional offspring dilutes the total resources available for parental investment. Although a quantity-quality trade-off between producing and investing in offspring has long been assumed in evolutionary biology, testing it directly in humans is difficult, partly owing to the long generation time of our species. Using data from an Icelandic genealogy (Íslendingabók) over two centuries, I address this issue and analyse the quantity-quality trade-off in humans. I demonstrate that the primary impact of parents on the fitness of their children is the result of resources and or investment, but not genes. This effect changes significantly across time, in response to environmental conditions. Overall, increasing reproduction has negative fitness consequences on offspring, such that each additional sibling reduces an individual's average lifespan and lifetime reproductive success. This analysis provides insights into the evolutionary conflict between producing and investing in children while also shedding light on some of the causes of the demographic transition.

  6. Study on liquid-metal MHD power generation system with two-phase natural circulation. Applicability to fast reactor conditions

    International Nuclear Information System (INIS)

    Saito, Masaki

    2001-03-01

    Feasibility study of the liquid-metal MHD power generation system combined with the high-density two-phase natural circulation has been performed for the applicability to the simple, autonomic energy conversion system of the liquid-metal cooled fast reactor. The present system has many promising aspects not only in the energy conversion process, but also in safety and economical improvements of the liquid-metal cooled fast reactor. In the previous report, as the first step of the feasibility study, the cycle analyses were performed to examine the effects of the main system parameters on the fundamental characteristics of the system. It was found that the cycle efficiency of the present system is enough competitive with that of the conventional steam turbine system. It was also found that the cycle efficiency depends strongly on the gas-liquid slip ratio in the two-phase flow channel. However, it is very difficult to estimate the gas-liquid slip ratio theoretically, especially in the heavy liquid metal two-phase natural circulation. For example, the effects of MHD load on the two-phase flow characteristics, such as the void fraction and gas-liquid slip ratio are not known well. In the present study, therefore, as the second step of the feasibility study, a series of the experiments were performed to investigate, especially, the effect of MHD load at the single-phase shown-comer flow channel on the characteristics of the two-phase natural circulation. In the first series of the experiments, Woods-metal (Density: 9517 Kg/m 3 ) and nitrogen gas were chosen as the two-phase working fluids. The MHD pressure drop was simulated by the ball valve. The experiments with water and nitrogen gas were also performed to check the effects of the physical properties. From the present experiments, it is found that the average void fraction in the two-phase flow channel is determined by the force balance between the MHD pressure drop, frictional and pressure losses in the tube, and

  7. The effect of elevated reproductive effort onhumoral immune function in collared flycatcher females

    Science.gov (United States)

    Cichoń, Mariusz; Dubiec, Anna; Chadzińska, Magdalena

    2001-02-01

    In order to test whether high reproductive investments impair immune function in naturally breeding collared flycatchers, we performed a brood manipulation experiment and simultaneously induced an immune response by challenging birds with a non-pathogenic antigen - sheep red blood cells (SRBC). Females rearing experimentally enlarged number of nestlings showed significantly lower level of specific anti-SRBC antibodies than control females attending unaltered broods, but only in one of the two study years. The haemoconcentration of leukocytes did not differ between the two groups in both study years. The significant difference in immunological responsiveness between control and enlarged group coincided with differences in survival probability to the next breeding season: females attending enlarged broods showed lower probability of survival than control females, but there was no relationship between the level of immune response and survival probability. Our results indicate that reproduction may indeed trade for resources with immune functions at least in terms of specific antibody production. However, as in the other studies on reproductive costs, these costs seem not always to be pronounced.

  8. Privatisation in reproductive health services in Pakistan: three case studies.

    Science.gov (United States)

    Ravindran, T K Sundari

    2010-11-01

    Privatisation in Pakistan's health sector was part of the Structural Adjustment Programme that started in 1998 following the country's acute foreign exchange crisis. This paper examines three examples of privatisation which have taken place in service delivery, management and capacity-building functions in the health sector: 1) large-scale contracting out of publicly-funded health services to private, not-for-profit organisations; 2) social marketing/franchising networks providing reproductive health services; and 3) a public-private partnership involving a consortium of private players and the government of Pakistan. It assesses the extent to which these initiatives have contributed to promoting equitable access to good quality, comprehensive reproductive health services. The paper concludes that these forms of privatisation in Pakistan's health sector have at best made available a limited range of fragmented reproductive health services, often of sub-optimal quality, to a fraction of the population, with poor returns in terms of health and survival, especially for women. This analysis has exposed a deep-rooted malaise within the health system as an important contributor to this situation. Sustained investment in health system strengthening is called for, where resources from both public and private sectors are channelled towards achieving health equity, under the stewardship of the state and with active participation by and accountability to members of civil society. Copyright © 2010 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

  9. The ethics of human reproductive cloning.

    Science.gov (United States)

    Strong, Carson

    2005-03-01

    This article addresses the question of whether human reproductive cloning could be ethically justifiable in at least some cases involving infertile couples who would choose cloning as a way to have a genetically related child. At present, the risk of congenital anomalies constitutes a compelling argument against human reproductive cloning. The article explores whether reproductive cloning could be ethically justifiable if, at some future time, cloning becomes possible without an elevated risk of anomalies. It is argued that freedom to use cloning is a form of procreative freedom and, as such, deserves respect. All of the objections that have been raised against human reproductive cloning fall under three main categories: those that appeal to the interests of the child, those based on consequences for society, and those arising from teleological views. Objections that appeal to the child's interests are, in turn, of two main kinds: consequentialist and deontological. All of these types of objections are examined, and it is found that each involves serious problems that prevent it from being a reasonable objection in the context of the infertility cases considered. It is concluded that human reproductive cloning would be ethically justifiable in at least some cases involving infertile couples, provided that it could be performed without an elevated risk of anomalies.

  10. Mutual tolerance or reproductive competition? Patterns of reproductive skew among male redfronted lemurs (Eulemur fulvus rufus)

    OpenAIRE

    Kappeler, Peter M.; Port, Markus

    2008-01-01

    The social organization of gregarious lemurs significantly deviates from predictions of the socioecological model, as they form small groups in which the number of males approximately equals the number of females. This study uses models of reproductive skew theory as a new approach to explain this unusual group composition, in particular the high number of males, in a representative of these lemurs, the redfronted lemur (Eulemur fulvus rufus). We tested two central predictions of “concession”...

  11. Surround by Sound: A Review of Spatial Audio Recording and Reproduction

    Directory of Open Access Journals (Sweden)

    Wen Zhang

    2017-05-01

    Full Text Available In this article, a systematic overview of various recording and reproduction techniques for spatial audio is presented. While binaural recording and rendering is designed to resemble the human two-ear auditory system and reproduce sounds specifically for a listener’s two ears, soundfield recording and reproduction using a large number of microphones and loudspeakers replicate an acoustic scene within a region. These two fundamentally different types of techniques are discussed in the paper. A recent popular area, multi-zone reproduction, is also briefly reviewed in the paper. The paper is concluded with a discussion of the current state of the field and open problems.

  12. Requirement of proline synthesis during Arabidopsis reproductive development

    Directory of Open Access Journals (Sweden)

    Funck Dietmar

    2012-10-01

    Full Text Available Abstract Background Gamete and embryo development are crucial for successful reproduction and seed set in plants, which is often the determining factor for crop yield. Proline accumulation was largely viewed as a specific reaction to overcome stress conditions, while recent studies suggested important functions of proline metabolism also in reproductive development. Both the level of free proline and proline metabolism were proposed to influence the transition to flowering, as well as pollen and embryo development. Results In this study, we performed a detailed analysis of the contribution of individual proline biosynthetic enzymes to vegetative development and reproductive success in Arabidopsis. In contrast to previous reports, we found that pyrroline-5-carboxylate (P5C synthetase 2 (P5CS2 is not essential for sexual reproduction although p5cs2 mutant plants were retarded in vegetative development and displayed reduced fertility under long-day conditions. Single mutant plants devoid of P5CS1 did not show any developmental defects. Simultaneous absence of both P5CS isoforms resulted in pollen sterility, while fertile egg cells could still be produced. Expression of P5C reductase (P5CR was indispensable for embryo development but surprisingly not needed for pollen or egg cell fertility. The latter observation could be explained by an extreme stability of P5CR activity, which had a half-life time of greater than 3 weeks in vitro. Expression of P5CR-GFP under the control of the endogenous P5CR promoter was able to restore growth of homozygous p5cr mutant embryos. The analysis of P5CR-GFP-fluorescence in planta supported an exclusively cytoplasmatic localisation of P5CR. Conclusions Our results demonstrate that potential alternative pathways for proline synthesis or inter-generation transfer of proline are not sufficient to overcome a defect in proline biosynthesis from glutamate during pollen development. Proline biosynthesis through P5CS2 and P5

  13. Genome editing and assisted reproduction: curing embryos, society or prospective parents?

    Science.gov (United States)

    Cavaliere, Giulia

    2018-06-01

    This paper explores the ethics of introducing genome-editing technologies as a new reproductive option. In particular, it focuses on whether genome editing can be considered a morally valuable alternative to preimplantation genetic diagnosis (PGD). Two arguments against the use of genome editing in reproduction are analysed, namely safety concerns and germline modification. These arguments are then contrasted with arguments in favour of genome editing, in particular with the argument of the child's welfare and the argument of parental reproductive autonomy. In addition to these two arguments, genome editing could be considered as a worthy alternative to PGD as it may not be subjected to some of the moral critiques moved against this technology. Even if these arguments offer sound reasons in favour of introducing genome editing as a new reproductive option, I conclude that these benefits should be balanced against other considerations. More specifically, I maintain that concerns regarding the equality of access to assisted reproduction and the allocation of scarce resources should be addressed prior to the adoption of genome editing as a new reproductive option.

  14. Morphology of the Male Reproductive System and Spermiogenesis of Dendroctonus armandi Tsai and Li (Coleoptera: Curculionidae: Scolytinae).

    Science.gov (United States)

    Wu, Yi-Fei; Wei, Lu-Sha; Anthony Torres, Mark; Zhang, Xu; Wu, Shao-Ping; Chen, Hui

    2017-01-01

    Studying the reproductive attributes of pests is central to understanding their life cycle history and in crafting management strategies to regulate, if not bring down, their population below threshold levels. In this article, the morphology of the male reproductive tract, topology of the spermatozoa, and salient features of spermiogenesis in the Chinese white pine beetle, Dendroctonus armandi Tsai and Li was studied to provide baseline information for further pest management studies. Results showed that male reproductive tract of this species differs from those documented in other Coleopterans by having 20 testicular tubules in each testis and the presence of two types of accessory glands. The spermatozoon is seen having peculiar characteristics such as an "h"-shaped acrosomal vesicle with a "puff"-like expansion, one centriole, one large spongy body, and two accessory bodies. Despite with some morphological differences of the male reproductive organ, spermatogenesis in this organism is similar to other Coleopterans. Overall, detailed studies regarding the components of the primary male reproductive organ of this beetle species would expand the knowledge on the less-understood biology of Coleopteran pests and would help in designing regulatory measures to conserve endemic and indigenous pine trees in China. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  15. Timing reproduction in teleost fish: cues and mechanisms

    Science.gov (United States)

    Juntti, Scott A; Fernald, Russell D

    2016-01-01

    Fish comprise half of extant vertebrate species and use a rich variety of reproductive strategies that have yielded insights into the basic mechanisms that evolved for sex. To maximize the chances of fertilization and survival of offspring, fish species time reproduction to occur at optimal times. For years, ethologists have performed painstaking experiments to identify sensory inputs and behavioral outputs of the brain during mating. Here we review known mechanisms that generate sexual behavior, focusing on the factors that govern the timing of these displays. The development of new technologies, including high-throughput sequencing and genome engineering, have the potential to provide novel insights into how the vertebrate brain consummates mating at the appropriate time. PMID:26952366

  16. Gender and Women's Reproductive Health

    Directory of Open Access Journals (Sweden)

    Aygul Akyuz

    2010-08-01

    Full Text Available AIM: According to the “rights to equality” in reproductive and sexual rights, “no persons should be discriminated against their sexual and reproductive lives, in their access to health care and/or services on the grounds of race, sex, sexual orientation, marital status, family position, age, language, religion, political, or other opinion; national or social origin, property, birth, or other status” In this context, health professionals devoted to reproductive health are responsible for the provision of services to individuals equally and should maintain equality rights. The aim of this study is to determine the effects of gender on the reproductive health of women and utilization of reproductive health services. METHODS: The study population consisted of 250 married women at their reproductive ages of 15 to 49, who applied to the obstetrics and gynecology service of a university hospital and a gynecology clinic of a training hospital dedicated to obstetrics and gynecology between 1 February 2007 and 30 April 2007. The data collection form was developed by researchers after evaluation of the relevant literature which relevance of gender discrimination could show where the questions. RESULTS: 52% of Women’ have graduated from primary school. Education levels of women with men (her husband between level of education is statistically significant difference, and women were receive less education than men (her husband (²=34.231, p<0.001. The study was determined that women who received training secondary school and above, worked and decision maker to domestic that they get prenatal care of a high percentage and deliver their babies in the hospital with the aid of a health care professional, and they go to medical center from gynecological problems and they need to obtain permission from their husbands in order to seek aid at a medical center of a low percentage (p<0.05. CONCLUSION: Women's reproductive health, gender discrimination status

  17. The koala (Phascolarctos cinereus): a case study in the development of reproductive technology in a marsupial.

    Science.gov (United States)

    Johnston, Stephen D; Holt, William V

    2014-01-01

    The successful development and application of an assisted breeding program in any animal relies primarily on a thorough understanding of the fundamental reproductive biology (anatomy, physiology and behaviour) of the species in question. Surely, the ultimate goal and greatest hallmark of such a program is the efficacious establishment of a series of reliable techniques that facilitate the reproductive and genetic management of fragmented populations, both in captivity and in the wild. Such an achievement is all the more challenging when the reproductive biology of that species is essentially rudimentary and without adequate reproductive models to compare to. Using the koala (Phascolarctos cinereus) as a case study, this chapter provides some personal insights into the evolution of a concept that began as a small undergraduate student project but that subsequently evolved into the first-ever successful artificial insemination of a marsupial. Apart from this historical perspective, we also provide a brief review of the current reproductive biology of the koala, discuss technical elements of current assisted breeding technology of this species, its potential application to the wombat, and the future role it might play in helping to conserve wild koala populations. There is little doubt that the unique reproductive biology and tractability of the koala has in this case been a benefit rather than a hindrance to the success of artificial breeding in this species.

  18. Nickel Nanoparticles Exposure and Reproductive Toxicity in Healthy Adult Rats

    Directory of Open Access Journals (Sweden)

    Lu Kong

    2014-11-01

    Full Text Available Nickel is associated with reproductive toxicity. However, the reproductive toxicity of nickel nanoparticles (Ni NPs is unclear. Our goal was to determine the association between nickel nanoparticle exposure and reproductive toxicity. According to the one-generation reproductive toxicity standard, rats were exposed to nickel nanoparticles by gavage and we selected indicators including sex hormone levels, sperm motility, histopathology, and reproductive outcome etc. Experimental results showed nickel nanoparticles increased follicle stimulating hormone (FSH and luteinizing hormone (LH, and lowered etradiol (E2 serum levels at a dose of 15 and 45 mg/kg in female rats. Ovarian lymphocytosis, vascular dilatation and congestion, inflammatory cell infiltration, and increase in apoptotic cells were found in ovary tissues in exposure groups. For male rats, the weights decreased gradually, the ratio of epididymis weight over body weight increased, the motility of rat sperm changed, and the levels of FSH and testosterone (T diminished. Pathological results showed the shedding of epithelial cells of raw seminiferous tubule, disordered arrangement of cells in the tube, and the appearance of cell apoptosis and death in the exposure group. At the same time, Ni NPs resulted in a change of the reproductive index and the offspring development of rats. Further research is needed to elucidate exposure to human populations and mechanism of actions.

  19. Reproduction of mountain birch along a strong pollution gradient near Monchegorsk, Northwestern Russia

    International Nuclear Information System (INIS)

    Kozlov, Mikhail V.; Zvereva, Elena L.

    2004-01-01

    We explored effects of severe pollution on sexual reproduction of mountain birch, Betula pubescens subsp. czerepanovii, by counting catkins on sample branches and weighing both somatic and generative structures of both short and long shoots from birches growing at 21 sites around large nickel-copper smelter at Monchegorsk, Northwestern Russia. Proportion of reproducing trees, production of catkins, shoot and catkin weight, as well as the relative difference in weight of somatic structures of generative and vegetative shoots, were generally independent of pollution load; in 2003 birches growing in industrial barrens produced more catkins than birches growing in unpolluted forests. Thus, we found no support for the hypothesis that reproductive allocation should decrease with decrease in environmental capacity. Absence of adverse effects might indicate that long-lasting pollution impact already eliminated the most sensitive individuals from the affected birch populations. - Capsule: Variation in reproductive characteristics of mountain birch near the nickel-copper smelter at Monchegorsk is independent of pollution load

  20. Study on sexual and reproductive health behaviors of unmarried female migrants in China

    NARCIS (Netherlands)

    He, D.; Zhou, Y.; Ji, N.; Wu, S.; Wang, Z.; Decat, P.; Moyer, E.; Minkauskiene, M.; Pang, C.; Cheng, Y.

    2012-01-01

    Aim: The purpose of this study was to broadly assess the level of knowledge, attitude and behaviors related to sexual and reproductive health (SRH) among unmarried female migrants in China. Material and Methods: This cross-sectional study was conducted and a self-administered questionnaire was