Melanocortin 4 receptor is not required for estrogenic regulations on energy homeostasis and reproduction

Science.gov (United States)

Brain estrogen receptor-a (ERa) is essential for estrogenic regulation of energy homeostasis and reproduction. We previously showed that ERa expressed by pro-opiomelanocortin (POMC) neurons mediates estrogen's effects on food intake, body weight, negative regulation of hypothalamic–pituitary–gonadal...

Goldfish neurokinin B: Cloning, tissue distribution, and potential role in regulating reproduction.

Science.gov (United States)

Qi, Xin; Zhou, Wenyi; Li, Shuisheng; Liu, Yun; Ye, Gang; Liu, Xiaochun; Peng, Chun; Zhang, Yong; Lin, Haoran

2015-09-15

Neurokinin B (NKB) is a member of the tackykinin (TAC) family known to play a critical role in the neuroendocrine regulation of reproduction in mammals. However, its biological functions in teleosts are less clear. The aim of this study was to determine the role of NKB in fish reproduction using goldfish as a model. Two transcripts, TAC3a and TAC3b, which encode several NKBs, including NKBa-13, NKBa-10, NKBb-13, and NKBb-11, were cloned. Phylogenetic analysis revealed that NKBa-10 and NKBb-11 are closely related to mammalian NKB, while NKB-13s are more conserved in teleosts. Quantitative real-time PCR analyses in various tissues showed that TAC3a and TAC3b mRNAs were mainly expressed in the brain. In situ hybridization further detected TAC3a and TAC3b mRNAs in several regions of the brain known to be involved in the regulation of reproduction and metabolism, as well as in the neurohypophysis of the pituitary. To investigate the potential role of NKBs in reproduction, goldfish were injected intraperitoneally with synthetic NKBa-13, -10, NKBb-13, or -11 peptides and the mRNA levels of hypothalamic gonadotropin-releasing hormone (GnRH) and pituitary gonadotropin subunits were measured. NKBa-13, -10, or NKBb-13, but not -11, significantly increased hypothalamic salmon GnRH and pituitary FSHβ and LHβ mRNA levels in both female and male goldfish. Finally, ovariectomy increased, while estradiol replacement reduced, TAC3a mRNA levels without affecting TAC3b expression in the hypothalamus. These data suggest that NKBa-13, -10, and NKBb-13 play a role in mediating the estrogen negative feedback regulation of gonadotropins. Copyright © 2014 Elsevier Inc. All rights reserved.

Information theory and the neuropeptidergic regulation of seasonal reproduction in mammals and birds.

Science.gov (United States)

Stevenson, Tyler J; Ball, Gregory F

2011-08-22

Seasonal breeding in the temperate zone is a dramatic example of a naturally occurring change in physiology and behaviour. Cues that predict periods of environmental amelioration favourable for breeding must be processed by the brain so that the appropriate responses in reproductive physiology can be implemented. The neural integration of several environmental cues converges on discrete hypothalamic neurons in order to regulate reproductive physiology. Gonadotrophin-releasing hormone-1 (GnRH1) and Kisspeptin (Kiss1) neurons in avian and mammalian species, respectively, show marked variation in expression that is positively associated with breeding state. We applied the constancy/contingency model of predictability to investigate how GnRH1 and Kiss1 integrate different environmental cues to regulate reproduction. We show that variation in GnRH1 from a highly seasonal avian species exhibits a predictive change that is primarily based on contingency information. Opportunistic species have low measures of predictability and exhibit a greater contribution of constancy information that is sex-dependent. In hamsters, Kiss1 exhibited a predictive change in expression that was predominantly contingency information and is anatomically localized. The model applied here provides a framework for studies geared towards determining the impact of variation in climate patterns to reproductive success in vertebrate species.

Progressive effects of silver nanoparticles on hormonal regulation of reproduction in male rats

International Nuclear Information System (INIS)

Dziendzikowska, K.; Krawczyńska, A.; Oczkowski, M.; Królikowski, T.; Brzóska, K.; Lankoff, A.; Dziendzikowski, M.; Stępkowski, T.; Kruszewski, M.

2016-01-01

The growing use of silver nanoparticles (AgNPs) in various applications, including consumer, agriculture and medicine products, has raised many concerns about the potential risks of nanoparticles (NPs) to human health and the environment. An increasing body of evidence suggests that AgNPs may have adverse effects of humans, thus the aim of this study was to investigate the effects of AgNPs on the male reproductive system. Silver particles (20 nm AgNPs (groups Ag I and Ag II) and 200 nm Ag sub-micron particles (SPs) (group Ag III)) were administered intravenously to male Wistar rats at a dose of 5 (groups Ag I and Ag III) or 10 (group Ag II) mg/kg of body weight. The biological material was sampled 24 h, 7 days and 28 days after injection. The obtained results revealed that the AgNPs had altered the luteinising hormone concentration in the plasma and the sex hormone concentration in the plasma and testes. Plasma and intratesticular levels of testosterone and dihydrotestosterone were significantly decreased both 7 and 28 days after treatment. No change in the prolactin and sex hormone-binding globulin concentration was observed. Exposure of the animals to AgNPs resulted in a considerable decrease in 5α-reductase type 1 and the aromatase protein level in the testis. Additionally, expression analysis of genes involved in steroidogenesis and the steroids metabolism revealed significant down-regulation of Star, Cyp11a1, Hsd3b1, Hsd17b3 and Srd5a1 mRNAs in AgNPs/AgSPs-exposed animals. The present study demonstrates the potential adverse effect on the hormonal regulation of the male reproductive function following AgNP/AgSP administration, in particular alterations of the sex steroid balance and expression of genes involved in steroidogenesis and the steroids metabolism. - Highlights: • Assessment of the toxic effects of AgNPs/AgSPs on the regulation of male reproductive function • AgNP −/AgSP-induced alterations of sex steroid status in male Wistar rats. �

Progressive effects of silver nanoparticles on hormonal regulation of reproduction in male rats

Energy Technology Data Exchange (ETDEWEB)

Dziendzikowska, K., E-mail: k.dziendzikowska@gmail.com [Division of Nutrition Physiology, Department of Dietetics, Faculty of Human Nutrition and Consumer Science, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159C, 02-776 Warsaw (Poland); Krawczyńska, A. [Laboratory of Molecular Biology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3, 05-110 Jabłonna (Poland); Oczkowski, M.; Królikowski, T. [Division of Nutrition Physiology, Department of Dietetics, Faculty of Human Nutrition and Consumer Science, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159C, 02-776 Warsaw (Poland); Brzóska, K. [Centre for Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Lankoff, A. [Centre for Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Department of Radiobiology and Immunology, Institute of Biology, Jan Kochanowski University, Świetokrzyska 15, 25-406 Kielce (Poland); Dziendzikowski, M. [Airworthiness Division, Air Force Institute of Technology, Ks. Boleslawa 6, 01-494 Warsaw (Poland); Stępkowski, T. [Centre for Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Kruszewski, M. [Department of Medical Biology and Translational Research, Faculty of Medicine, University of Information Technology and Management, Sucharskiego 2, 35-225 Rzeszów (Poland); Department of Molecular Biology and Translational Research, Institute of Rural Health, Jaczewskiego 2, 20-090 Lublin (Poland); and others

2016-12-15

The growing use of silver nanoparticles (AgNPs) in various applications, including consumer, agriculture and medicine products, has raised many concerns about the potential risks of nanoparticles (NPs) to human health and the environment. An increasing body of evidence suggests that AgNPs may have adverse effects of humans, thus the aim of this study was to investigate the effects of AgNPs on the male reproductive system. Silver particles (20 nm AgNPs (groups Ag I and Ag II) and 200 nm Ag sub-micron particles (SPs) (group Ag III)) were administered intravenously to male Wistar rats at a dose of 5 (groups Ag I and Ag III) or 10 (group Ag II) mg/kg of body weight. The biological material was sampled 24 h, 7 days and 28 days after injection. The obtained results revealed that the AgNPs had altered the luteinising hormone concentration in the plasma and the sex hormone concentration in the plasma and testes. Plasma and intratesticular levels of testosterone and dihydrotestosterone were significantly decreased both 7 and 28 days after treatment. No change in the prolactin and sex hormone-binding globulin concentration was observed. Exposure of the animals to AgNPs resulted in a considerable decrease in 5α-reductase type 1 and the aromatase protein level in the testis. Additionally, expression analysis of genes involved in steroidogenesis and the steroids metabolism revealed significant down-regulation of Star, Cyp11a1, Hsd3b1, Hsd17b3 and Srd5a1 mRNAs in AgNPs/AgSPs-exposed animals. The present study demonstrates the potential adverse effect on the hormonal regulation of the male reproductive function following AgNP/AgSP administration, in particular alterations of the sex steroid balance and expression of genes involved in steroidogenesis and the steroids metabolism. - Highlights: • Assessment of the toxic effects of AgNPs/AgSPs on the regulation of male reproductive function • AgNP −/AgSP-induced alterations of sex steroid status in male Wistar rats. �

Conceptual Model of Business Situation of Attraction and Reproduction of Temporary Personnel of the Event Service

Directory of Open Access Journals (Sweden)

Donets Oleksiy S.

2014-01-01

Full Text Available The article considers importance of formation of the acting system of personnel management, since personnel determines the competitive potential and competitive advantages of an organisation. It develops a cognitive model of a business situation, which helps to present the process of attraction and reproduction of temporary personnel at enterprises, which deal with organisation of large-scale events, and influence of the factors upon each other. It builds a conceptual model of a business situation of attraction and reproduction of temporary personnel of the event service and, on its basis, offers a model of decision making with the use of elements of fuzzy logic on selection of a specialist for a specific position. It allocates main characteristics of employees, which are taken into account when forming decisions regarding taking on a candidate.

Phenotypic selection and regulation of reproduction in different environments in wild barley

NARCIS (Netherlands)

Volis, S.; Verhoeven, K.J.F.; Mendlinger, S.; Ward, D.

2004-01-01

Plasticity of the phenotypic architecture of wild barley, Hordeum spontaneum, was studied in response to water and nutrient stress. Direct and indirect selection on several vegetative and reproductive traits was estimated and path analysis used to reveal how regulating pathways via maternal

The regulation of reproductive neuroendocrine function by insulin and insulin-like growth factor-1 (IGF-1).

Science.gov (United States)

Wolfe, Andrew; Divall, Sara; Wu, Sheng

2014-10-01

The mammalian reproductive hormone axis regulates gonadal steroid hormone levels and gonadal function essential for reproduction. The neuroendocrine control of the axis integrates signals from a wide array of inputs. The regulatory pathways important for mediating these inputs have been the subject of numerous studies. One class of proteins that have been shown to mediate metabolic and growth signals to the CNS includes Insulin and IGF-1. These proteins are structurally related and can exert endocrine and growth factor like action via related receptor tyrosine kinases. The role that insulin and IGF-1 play in controlling the hypothalamus and pituitary and their role in regulating puberty and nutritional control of reproduction has been studied extensively. This review summarizes the in vitro and in vivo models that have been used to study these neuroendocrine structures and the influence of these growth factors on neuroendocrine control of reproduction. Copyright © 2014 Elsevier Inc. All rights reserved.

Non-photoperiodic regulation of reproductive physiology in the flexibly breeding pine siskin (Spinus pinus)

OpenAIRE

Watts, Heather E.; Hahn, Thomas P.

2012-01-01

In order to time reproduction to coincide with favorable conditions, animals use environmental cues to up- and down-regulate the reproductive axis appropriately. Although photoperiodic cues are one of the best studied of such environmental cues, animals also attend to others such as temperature, food availability, rainfall and social cues. Such non-photic cues are expected to be particularly important for tropical species and temperate-zone species that exhibit flexible or opportunistic breed...

Cultural differences in hedonic emotion regulation after a negative event.

Science.gov (United States)

Miyamoto, Yuri; Ma, Xiaoming; Petermann, Amelia G

2014-08-01

Beliefs about emotions can influence how people regulate their emotions. The present research examined whether Eastern dialectical beliefs about negative emotions lead to cultural differences in how people regulate their emotions after experiencing a negative event. We hypothesized that, because of dialectical beliefs about negative emotions prevalent in Eastern culture, Easterners are less motivated than Westerners to engage in hedonic emotion regulation-up-regulation of positive emotions and down-regulation of negative emotions. By assessing online reactions to a recent negative event, Study 1 found that European Americans are more motivated to engage in hedonic emotion regulation. Furthermore, consistent with the reported motivation to regulate emotion hedonically, European Americans show a steeper decline in negative emotions 1 day later than do Asians. By examining retrospective memory of reactions to a past negative event, Study 2 further showed that cultural differences in hedonic emotion regulation are mediated by cultural differences in dialectical beliefs about motivational and cognitive utility of negative emotions, but not by personal deservingness or self-efficacy beliefs. These findings demonstrate the role of cultural beliefs in shaping emotion regulation and emotional experiences.

Reproductive toxicity of a mixture of regulated drinking-water disinfection by-products in a multigenerational rat bioassay

Science.gov (United States)

BACKGROUND:Trihalomethanes (THMs) and haloaretic acids (HAAs) are regulated disinfection by-products (DBPs); their joint reproductive toxicity in drinking water is unknown.OBJECTIVE: We aimed to evaluate a drinking water mixture of the four regulated THMs and five regulated HAAs ...

A Role for Glucocorticoids in Stress-Impaired Reproduction: Beyond the Hypothalamus and Pituitary

OpenAIRE

Whirledge, Shannon; Cidlowski, John A.

2013-01-01

In addition to the well-characterized role of the sex steroid receptors in regulating fertility and reproduction, reproductive events are also mediated by the hypothalamic-pituitary-adrenal axis in response to an individual's environment. Glucocorticoid secretion in response to stress contributes to the well-characterized suppression of the hypothalamic-pituitary-gonadal axis through central actions in the hypothalamus and pituitary. However, both animal and in vitro studies indicate that oth...

Leptin Regulation of Gonadotrope Gonadotropin-Releasing Hormone Receptors As a Metabolic Checkpoint and Gateway to Reproductive Competence

Directory of Open Access Journals (Sweden)

Angela K. Odle

2018-01-01

Full Text Available The adipokine leptin signals the body’s nutritional status to the brain, and particularly, the hypothalamus. However, leptin receptors (LEPRs can be found all throughout the body and brain, including the pituitary. It is known that leptin is permissive for reproduction, and mice that cannot produce leptin (Lep/Lep are infertile. Many studies have pinpointed leptin’s regulation of reproduction to the hypothalamus. However, LEPRs exist at all levels of the hypothalamic–pituitary–gonadal axis. We have previously shown that deleting the signaling portion of the LEPR specifically in gonadotropes impairs fertility in female mice. Our recent studies have targeted this regulation to the control of gonadotropin releasing hormone receptor (GnRHR expression. The hypotheses presented here are twofold: (1 cyclic regulation of pituitary GnRHR levels sets up a target metabolic checkpoint for control of the reproductive axis and (2 multiple checkpoints are required for the metabolic signaling that regulates the reproductive axis. Here, we emphasize and explore the relationship between the hypothalamus and the pituitary with regard to the regulation of GnRHR. The original data we present strengthen these hypotheses and build on our previous studies. We show that we can cause infertility in 70% of female mice by deleting all isoforms of LEPR specifically in gonadotropes. Our findings implicate activin subunit (InhBa mRNA as a potential leptin target in gonadotropes. We further show gonadotrope-specific upregulation of GnRHR protein (but not mRNA levels following leptin stimulation. In order to try and understand this post-transcriptional regulation, we tested candidate miRNAs (identified with in silico analysis that may be binding the Gnrhr mRNA. We show significant upregulation of one of these miRNAs in our gonadotrope-Lepr-null females. The evidence provided here, combined with our previous work, lay the foundation for metabolically regulated post

HR38, an ortholog of NR4A family nuclear receptors, mediates 20-hydroxyecdysone regulation of carbohydrate metabolism during mosquito reproduction.

Science.gov (United States)

Dong, Dujuan; Zhang, Yang; Smykal, Vlastimil; Ling, Lin; Raikhel, Alexander S

2018-05-01

The Aedes aegypti mosquito is the principal vector for many dangerous human viral diseases. Carbohydrate metabolism (CM) is essential for supplying the energy necessary for host seeking, blood digestion and rapid egg development of this vector insect. The steroid hormone 20-hydroxyecdysone (20E) and the ecdysone receptor (EcR) are important regulators of CM, coordinating it with female reproductive events. We report here that the NR4A nuclear receptor AHR38 plays a critical role in mediating these actions of 20E and EcR. AHR38 RNA interference (RNAi) depletion in female mosquitoes blocked the transcriptional activation of CM genes encoding phosphoglucomutase (PGM) and trehalose-6-phophate synthase (TPS); it caused an increase of glycogen accumulation and a decrease of the circulating sugar trehalose. This treatment also resulted in a dramatic reduction in fecundity. Considering that these phenotypes resulting from AHR38 RNAi depletion are similar to those of EcR RNAi, we investigated a possible connection between these transcription factors in CM regulation. EcR RNAi inhibits the AHR38 gene expression. Moreover, the 20E-induced EcR complex directly activates AHR38 by binding to the ecdysone response element (EcRE) in the upstream regulatory region of this gene. The present work has implicated AHR38 in the 20E-mediated control of CM and provided new insight into mechanisms of 20E regulation of metabolism during female mosquito reproduction. © 2018 Published by Elsevier Ltd.

Morals or markets? Regulating assisted reproductive technologies as morality or economic policies in the states.

Science.gov (United States)

Heidt-Forsythe, Erin

2017-01-01

The availability of assisted reproductive technologies (ARTs) in the medical marketplace complicates our understanding of reproductive public policy in the United States. Political debates over ARTs often are based on fundamental moral principles of life, reproduction, and kinship, similar to other reproductive policies in the United States. However, ARTs are an important moneymaking private enterprise for the U.S. biotechnology industry. This project investigates how the U.S. states regulate these unique and challenging technologies as either moral policies or economic policies. This study employs ordinary least squares (OLS) regression to estimate the significance of morality and economic policy variables on ART policies at the state level, noting associations between state-level political, economic, and gender variables on restrictive and permissive state-level ART policies. Economic variables (reflecting the biotechnology industry) and advocacy for access to ART on behalf of infertility patients increase the chances of states passing policies that enable consumer use of ARTs. Additionally, individual ART policies are distinct from one another in the ways that morality variables increase the chances of ART regulations. Surprisingly, the role of religious adherence among state residents varied in positive and negative relationships with individual policy passage. In general, these results support the hypothesis that ART laws are associated with economic as well as moral concerns of the states-ARTs lie at the intersection of issues of life and reproduction and of scientific innovation and health. What is most striking about these results is that they do not follow patterns seen in the legislation of abortion, contraception, and sexuality in general-those reproductive policies that are considered "morality policy." Similarly, economic variables are not consistently significant in the expected direction.

76 FR 1381 - Special Local Regulations for Marine Events; Potomac River, Charles County, MD

Science.gov (United States)

2011-01-10

...-AA08 Special Local Regulations for Marine Events; Potomac River, Charles County, MD AGENCY: Coast Guard... Regulations for Marine Events; Potomac River, Charles County, MD. (a) Regulated area. The following location... local regulations during the ``Potomac River Sharkfest Swim'' amateur swim, a marine event to be held on...

ROLE OF SEROTONIN IN FISH REPRODUCTION

Directory of Open Access Journals (Sweden)

Parvathy ePrasad

2015-06-01

Full Text Available The neuroendocrine mechanism regulates reproduction through the hypothalamo-pituitary-gonadal (HPG axis which is evolutionarily conserved in vertebrates. The HPG axis is regulated by a variety of internal as well as external factors. Serotonin, a monoamine neurotransmitter, is involved in a wide range of reproductive functions. In mammals, serotonin regulates sexual behaviours, gonadotropin release and gonadotropin-release hormone (GnRH secretion. However, the serotonin system in teleost may play unique role in the control of reproduction as the mechanism of reproductive control in teleosts is not always the same as in the mammalian models. In fish, the serotonin system is also regulated by natural environmental factors as well as chemical substances. In particular, selective serotonin reuptake inhibitors (SSRIs are commonly detected as pharmaceutical contaminants in the natural environment. Those factors may influence fish reproductive functions via the serotonin system. This review summarizes the functional significance of serotonin in the teleosts reproduction.

Effects of silicon on the penetration and reproduction events of Meloidogyne exigua on coffee roots

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Rodrigo Vieira Silva

2015-06-01

Full Text Available Considering that the root-knot nematode Meloidogyne exigua has caused great yield losses to coffee production in Brazil, this study aimed to determine whether the penetration and the reproduction events of this nematode on the roots of plants from two coffee cultivars with different levels of basal resistance to this nematode could be affected by silicon (Si. Coffee plants from the cultivars Catuaí and IAPAR 59, which are susceptible and resistant, respectively, to M. exigua, were grown in pots containing Si-deficient soil that was amended with either calcium silicate (+Si or calcium carbonate (–Si. The Si concentration on the root tissue significantly increased by 159 and 97% for the +Si plants from the cultivars Catuaí and IAPAR 59, respectively, compared to the –Si plants of these cultivars. The population of M. exigua, the number of galls and the number of eggs were significantly reduced on the roots of the +Si plants of the cultivars Catuaí and IAPAR 59 compared to the –Si plants of these cultivars. It was concluded that the development and reproduction events of M. exigua were negatively impacted on the roots of coffee plants supplied with Si.

On reproduction in red algae: further research needed at the molecular level

Science.gov (United States)

García-Jiménez, Pilar; Robaina, Rafael R.

2015-01-01

Multicellular red algae (Rhodophyta) have some of the most complex life cycles known in living organisms. Economically valuable seaweeds, such as phycocolloid producers, have a triphasic (gametophyte, carposporophyte, and tetrasporophyte) life cycle, not to mention the intricate alternation of generations in the edible “sushi-alga” nori. It is a well-known fact that reproductive processes are controlled by one or more abiotic factor(s), including day length, light quality, temperature, and nutrients. Likewise, endogenous chemical factors such as plant growth regulators have been reported to affect reproductive events in some red seaweeds. Still, in the genomic era and given the high throughput techniques at our disposal, our knowledge about the endogenous molecular machinery lags far behind that of higher plants. Any potential effective control of the reproductive process will entail revisiting most of these results and facts to answer basic biological questions as yet unresolved. Recent results have shed light on the involvement of several genes in red alga reproductive events. In addition, a working species characterized by a simple filamentous architecture, easy cultivation, and accessible genomes may also facilitate our task. PMID:25755663

On reproduction in red algae: further research needed at the molecular level

Directory of Open Access Journals (Sweden)

Pilar eGarcía-Jiménez

2015-02-01

Full Text Available Multicellular red algae (Rhodophyta have some of the most complex life cycles known in living organisms. Economically valuable seaweeds, such as phycocolloid producers, have a triphasic (gametophyte, carposporophyte and tetrasporophyte life cycle, not to mention the intricate alternation of generations in the edible sushi-alga nori. It is a well-known fact that reproductive processes are controlled by one or more abiotic factor(s, including day length, light quality, temperature and nutrients. Likewise, endogenous chemical factors such as plant growth regulators have been reported to affect reproductive events in some red seaweeds. Still, in the genomic era and given the high throughput techniques at our disposal, our knowledge about the endogenous molecular machinery lags far behind that of higher plants. Any potential effective control of the reproductive process will entail revisiting most of these results and facts to answer basic biological questions as yet unresolved. Recent results have shed light on the involvement of several genes in red alga reproductive events. In addition, a working species characterized by a simple filamentous architecture, easy cultivation and accessible genomes may also facilitate our task.

Local density regulates migratory songbird reproductive success through effects on double-brooding and nest predation.

Science.gov (United States)

Woodworth, Bradley K; Wheelwright, Nathaniel T; Newman, Amy E M; Norris, D Ryan

2017-08-01

Knowledge of the density-dependent processes that regulate animal populations is key to understanding, predicting, and conserving populations. In migratory birds, density-dependence is most often studied during the breeding season, yet we still lack a robust understanding of the reproductive traits through which density influences individual reproductive success. We used 27-yr of detailed, individual-level productivity data from an island-breeding population of Savannah sparrows Passerculus sandwichensis to evaluate effects of local and total annual population density on female reproductive success. Local density (number of neighbors within 50 m of a female's nest) had stronger effects on the number of young fledged than did total annual population density. Females nesting in areas of high local density were more likely to suffer nest predation and less likely to initiate and fledge a second clutch, which led to fewer young fledged in a season. Fledging fewer young subsequently decreased the likelihood of a female recruiting offspring into the breeding population in a subsequent year. Collectively, these results provide insight into the scale and reproductive mechanisms mediating density-dependent reproductive success and fitness in songbirds. © 2017 by the Ecological Society of America.

Adolescent Depression and Negative Life Events, the Mediating Role of Cognitive Emotion Regulation

Science.gov (United States)

Stikkelbroek, Yvonne; Bodden, Denise H. M.; Kleinjan, Marloes; Reijnders, Mirjam; van Baar, Anneloes L.

2016-01-01

Background Depression during adolescence is a serious mental health problem. Difficulties in regulating evoked emotions after stressful life events are considered to lead to depression. This study examined if depressive symptoms were mediated by various cognitive emotion regulation strategies after stressful life events, more specifically, the loss of a loved one, health threats or relational challenges. Methods We used a sample of 398 adolescents (Mage = 16.94, SD = 2.90), including 52 depressed outpatients, who all reported stressful life event(s). Path analyses in Mplus were used to test mediation, for the whole sample as well as separately for participants scoring high versus low on depression, using multigroup analyses. Results Health threats and relational challenging stressful life events were associated with depressive symptoms, while loss was not. More frequent use of maladaptive strategies was related to more depressive symptoms. More frequent use of adaptive strategies was related to less depressive symptoms. Specific life events were associated with specific emotion regulation strategies. The relationship between challenging, stressful life events and depressive symptoms in the whole group was mediated by maladaptive strategies (self-blame, catastrophizing and rumination). No mediation effect was found for adaptive strategies. Conclusion The association between relational challenging, stressful life events and depressive symptoms was mediated by maladaptive, cognitive emotion regulation strategies. PMID:27571274

77 FR 6708 - Special Local Regulations for Marine Events; Potomac River, Charles County, MD

Science.gov (United States)

2012-02-09

...-AA08 Special Local Regulations for Marine Events; Potomac River, Charles County, MD AGENCY: Coast Guard... River, Charles County, MD. (a) Regulated area. The following location is a regulated area: All waters of... local regulations during the ``Potomac River Sharkfest Swim'' amateur swim, a marine event to be held on...

Sex Differences and Emotion Regulation: An Event-Related Potential Study

OpenAIRE

Gardener, Elyse K. T.; Carr, Andrea R.; MacGregor, Amy; Felmingham, Kim L.

2013-01-01

Difficulties in emotion regulation have been implicated as a potential mechanism underlying anxiety and mood disorders. It is possible that sex differences in emotion regulation may contribute towards the heightened female prevalence for these disorders. Previous fMRI studies of sex differences in emotion regulation have shown mixed results, possibly due to difficulties in discriminating the component processes of early emotional reactivity and emotion regulation. The present study used event...

ATP-binding cassette transporters in reproduction: a new frontier

Science.gov (United States)

Bloise, E.; Ortiga-Carvalho, T.M.; Reis, F.M.; Lye, S.J.; Gibb, W.; Matthews, S.G.

2016-01-01

BACKGROUND The transmembrane ATP-binding cassette (ABC) transporters actively efflux an array of clinically relevant compounds across biological barriers, and modulate biodistribution of many physiological and pharmacological factors. To date, over 48 ABC transporters have been identified and shown to be directly and indirectly involved in peri-implantation events and fetal/placental development. They efflux cholesterol, steroid hormones, vitamins, cytokines, chemokines, prostaglandins, diverse xenobiotics and environmental toxins, playing a critical role in regulating drug disposition, immunological responses and lipid trafficking, as well as preventing fetal accumulation of drugs and environmental toxins. METHODS This review examines ABC transporters as important mediators of placental barrier functions and key reproductive processes. Expression, localization and function of all identified ABC transporters were systematically reviewed using PubMed and Google Scholar websites to identify relevant studies examining ABC transporters in reproductive tissues in physiological and pathophysiological states. Only reports written in English were incorporated with no restriction on year of publication. While a major focus has been placed on the human, extensive evidence from animal studies is utilized to describe current understanding of the regulation and function of ABC transporters relevant to human reproduction. RESULTS ABC transporters are modulators of steroidogenesis, fertilization, implantation, nutrient transport and immunological responses, and function as ‘gatekeepers’ at various barrier sites (i.e. blood-testes barrier and placenta) against potentially harmful xenobiotic factors, including drugs and environmental toxins. These roles appear to be species dependent and change as a function of gestation and development. The best-described ABC transporters in reproductive tissues (primarily in the placenta) are the multidrug transporters p-glycoprotein and

Public Health Events and International Health Regulations

Centers for Disease Control (CDC) Podcasts

2012-06-21

Dr. Katrin Kohl, a medical officer at the CDC, discusses the World Health Organization’s International Health Regulations for assessing and reporting on public health events across the world.  Created: 6/21/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 6/21/2012.

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...

Possible Involvement of Photoperiodic Regulation in Reproductive Endocrine System of Female Olive Flounder Paralichthys olivaceus.

Science.gov (United States)

Kim, Hyun Chul; Lee, Chi Hoon; Hur, Sung Pyu; Kim, Byeong Hoon; Park, Jun Young; Lee, Young Don

2015-03-01

This study investigated possible involvement of photoperiodic regulation in reproductive endocrine system of female olive flounder. To investigate the influence on brain-pituitary axis in endocrine system by regulating photoperiod, compared expression level of Kisspeptin and sbGnRH mRNA in brain and FSH-β, LH-β and GH mRNA in pituitary before and after spawning. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from Aug. 2013 to Jun. 2014. Continuous long photoperiod treatment from Aug. (post-spawning phase) was inhibited gonadal development of female olive flounder. In natural photoperiod group, the Kiss2 expression level a significant declined in Mar. (spawning period). And also, FSH-β, LH-β and GH mRNA expression levels were increasing at this period. However, in long photoperiod group, hypothalamic Kiss2, FSH-β, LH-β and GH mRNA expression levels did not show any significant fluctuation. These results suggest that expression of hypothalamic Kiss2, GtH and GH in the pituitary would change in response to photoperiod and their possible involvement of photoperiodic regulation in reproductive endocrine system of the BPG axis.

A non-invasive identification of hormone metabolites, gonadal event and reproductive status of captive female tigers

Directory of Open Access Journals (Sweden)

HERI DWI PUTRANTO

2011-07-01

Full Text Available Putranto HD (2011 A non-invasive identification of hormone metabolites, gonadal event and reproductive status of captive female tigers. Biodiversitas 12: 131-135. As a non-invasive method, fecal sample provides some advantage for animal and collector. The purpose of the present study were to monitor the reproductive status of female Siberian tigers (Panthera tigris altaica by assessing changes in fecal during natural ovarian activity and pregnancy and to identify whether progesterone (P4 exists and what kinds of P4 metabolites excreted into the feces. Two female tigers were fed a diet consisting of meat. Drinking water was available ad libitum. Feces were collected ones to twice a week. The fecal contents of P4 and estradiol-17β (E2 were determined by EIA and P4 metabolites were separated by a modified HPLC. The EIA results shown that during its natural ovarian activitythe E2 contents showed cyclic changes at the average of 27.0 d interval, however, no distinct cycles were shown in fecal P4 contents of non-pregnant tiger. In contrary, the fecal P4 contents in pregnant tiger increased remarkably after copulation approximately 2- to 6-fold higher than the mean value. The HPLC results indicated that two peaks were primarily detected fraction 63- 64 min (identified metabolites and fraction 85 min (not identified metabolite in feces of pregnant tiger. However, P4 detected only small amount in feces. It is possible to assess non-invasively gonadal events such as luteal or follicular activity or ovulation of Siberian tigers by endocrine monitoring based on fecal P4 and E2 to understand reproductive status.

Gene pathways that delay Caenorhabditis elegans reproductive senescence.

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Meng C Wang

2014-12-01

Full Text Available Reproductive senescence is a hallmark of aging. The molecular mechanisms regulating reproductive senescence and its association with the aging of somatic cells remain poorly understood. From a full genome RNA interference (RNAi screen, we identified 32 Caenorhabditis elegans gene inactivations that delay reproductive senescence and extend reproductive lifespan. We found that many of these gene inactivations interact with insulin/IGF-1 and/or TGF-β endocrine signaling pathways to regulate reproductive senescence, except nhx-2 and sgk-1 that modulate sodium reabsorption. Of these 32 gene inactivations, we also found that 19 increase reproductive lifespan through their effects on oocyte activities, 8 of them coordinate oocyte and sperm functions to extend reproductive lifespan, and 5 of them can induce sperm humoral response to promote reproductive longevity. Furthermore, we examined the effects of these reproductive aging regulators on somatic aging. We found that 5 of these gene inactivations prolong organismal lifespan, and 20 of them increase healthy life expectancy of an organism without altering total life span. These studies provide a systemic view on the genetic regulation of reproductive senescence and its intersection with organism longevity. The majority of these newly identified genes are conserved, and may provide new insights into age-associated reproductive senescence during human aging.

Legal regulation of assisted reproduction treatment in Russia.

Science.gov (United States)

Svitnev, Konstantin

2010-06-01

Russia remains one of the countries with a most favourable approach towards human reproduction in Europe, allowing almost everybody wanting to have a child of their own through assisted reproduction treatment to fulfill their dream. The legal situation around assisted reproduction treatment in Russia is very favourable; surrogacy, gamete and embryo donation are permitted, even on a commercial level. Gestational surrogacy is an option for heterosexual couples and single women, although a court decision might be needed to register a 'surrogate' child born to a couple who are not officially married or a single woman. However, it is not explicitly allowed nor prohibited for single men. Copyright 2010 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

76 FR 15214 - Special Local Regulations for Marine Events; Potomac River, Charles County, MD

Science.gov (United States)

2011-03-21

...-AA08 Special Local Regulations for Marine Events; Potomac River, Charles County, MD AGENCY: Coast Guard... for Marine Events; Potomac River, Charles County, MD'' in the Federal Register (76 FR 1381). We... follows: Sec. 100.35-T05-1113 Special Local Regulations for Marine Events; Potomac River, Charles County...

Brain serotonin, psychoactive drugs, and effects on reproduction.

Science.gov (United States)

Ayala, María Elena

2009-12-01

Serotonin, a biogenic amine, is present in significant amounts in many structures of the CNS. It is involved in regulation of a wide variety of physiological functions, such as sensory and motor functions, memory, mood, and secretion of hormones including reproductive hormones. It has also been implicated in the etiology of a range of psychiatric disorders such as anxiety, depression, and eating disorders, along with other conditions such as obesity and migraine. While some drugs that affect serotonin, such as fenfluramine and fluoxetine, have been successfully used in treatment of a range of psychiatric diseases, others, such as the amphetamine analogues MDMA and METH, are potent psychostimulant drugs of abuse. Alterations in serotonergic neurons caused by many of these drugs are well characterized; however, little is known about the reproductive consequences of such alterations. This review evaluates the effects of drugs such as MDMA, pCA, fenfluramine, and fluoxetine on serotonergic transmission in the brain, examines the relationships of these drug effects with the neuroendocrine mechanisms modulating reproductive events such as gonadotropin secretion, ovulation, spermatogenesis, and sexual behavior in animal models, and discusses possible reproductive implications of these drugs in humans.

Sex steroid hormone determination of the maternal brain: effects beyond reproduction.

Science.gov (United States)

Kinsley, C H; Meyer, E; Rafferty, K A

2012-10-01

Herein we discuss the effects of hormones on reproduction, but with a focus on the ripples that emanate from the main effects. That is, the role of hormones in reproductive events is both well-known and well accepted; less studied and understood are effects that appear to be ancillary to the primary objectives of the hormonal effects, which support, complement and extend their primary effects. We present evidence for how the hormonal stimulation of pregnancy constructs the maternal brain; makes it more efficient; enhances cognition; regulates stress responsiveness; modifies sensory systems (we discuss mainly olfaction); neurogenesis; and learning. Thus, steroid and other hormones and neuropeptides restructure the nervous system, particularly of females, to produce and regulate maternal behavior as well as behaviors and physiological systems that contribute to and support what is arguably the primary function of the hormones: survival and effective nurturance of the female's metabolic and genetic investment.

75 FR 748 - Special Local Regulation for Marine Events; Recurring Marine Events in the Fifth Coast Guard...

Science.gov (United States)

2010-01-06

... recurring marine events within the Fifth Coast Guard District. These regulations make minor changes to the... includes but is not limited to sail boat regattas, boat parades, power boat racing, swimming events, crew racing, and sail board racing. Under figure 2-1, paragraph (34)(h), of the Instruction, an environmental...

Emotion regulation of events central to identity and their relationship with concurrent and prospective depressive symptoms

DEFF Research Database (Denmark)

del Palacio Gonzalez, Adriana; Berntsen, Dorthe

2017-01-01

) reported the extent to which they employed a selection of emotion regulation strategies when recalling low- and high-centrality events. Dispositional emotion regulation and depressive symptoms were also assessed. A 7-week follow-up was conducted. High-centrality events were associated with more emotion...... regulation efforts. Greater brooding and expressive suppression in relation to high-centrality memories predicted concurrent depressive symptoms after controlling for event valence and dispostional emotion regulation. Effects were absent for low-centrality memories. Emotion regulation in response to high......-centrality memories did not predict depressive symptoms at follow-up beyond baseline depressive symptoms. Overall, the findings showed that maladaptive emotion regulation in response to memories of high-centrality events is important for explaining depressive symptomatology....

Fulicin regulates the female reproductive organs of the snail, Achatina fulica.

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Fujisawa, Y; Masuda, K; Minakata, H

2000-08-01

Fulicin is a D-amino acid-containing neuropeptide that has been thought to control male copulatory behavior in the land snail, Achatina fulica. In the present study, we demonstrated that the vagina and the oviduct of Achatina were densely innervated by fulicin-like immunoreactive neuronal fibers. We confirmed that fulicin was actually present in the vagina by mass spectrometry. Furthermore, fulicin showed a profound excitatory effect on contractions of the vagina and the oviduct. These results suggest that fulicin controls female egg-laying behavior as an excitatory neuropeptide regulating the female reproductive organs of the snail.

Reproductive life events and Alzheimer’s disease in Italian women: a retrospective study

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Bono G

2012-11-01

Full Text Available Chiara Zucchella,1 Elena Sinforiani,1 Antonietta Citterio,1 Valentina Giarracca,2 Giorgio Bono,2 Marco Mauri21IRCCS National Neurological Institute, C Mondino Foundation, Pavia, Italy; 2Department of Neurology, Ospedale di Circolo/Università dell’Insubria, Varese, ItalyAbstract: The aim of our study was to understand the complex relationship between the major reproductive life events in women with Alzheimer’s disease. In a retrospective, case-control study, 275 women with Alzheimer’s disease (AD and 276 control patients from a hospital population were enrolled from July 2007 to December 2010. The AD patients presented with later menopause (P < 0.01, lower occurrence of surgical menopause (P < 0.04, reduced hormone-replacement therapy intake (P < 0.0001, and a longer reproductive life span (P < 0.01, compared to controls. No significant differences were found with respect to age at puberty, number of pregnancies, previous abortions, or contraceptive therapy. A higher education level appeared to have a protective role against the risk of developing AD. In women, menopause and hormone-replacement therapy can differentially modulate the clinical manifestations of AD, but these factors do not play a predictive role in its development.Keywords: Alzheimer’s disease, gender, menopause, hormone-replacement therapy, surgical menopause, education

Regulation of Lysosomal Function by the DAF-16 Forkhead Transcription Factor Couples Reproduction to Aging in Caenorhabditis elegans.

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Baxi, Kunal; Ghavidel, Ata; Waddell, Brandon; Harkness, Troy A; de Carvalho, Carlos E

2017-09-01

Aging in eukaryotes is accompanied by widespread deterioration of the somatic tissue. Yet, abolishing germ cells delays the age-dependent somatic decline in Caenorhabditis elegans In adult worms lacking germ cells, the activation of the DAF-9/DAF-12 steroid signaling pathway in the gonad recruits DAF-16 activity in the intestine to promote longevity-associated phenotypes. However, the impact of this pathway on the fitness of normally reproducing animals is less clear. Here, we explore the link between progeny production and somatic aging and identify the loss of lysosomal acidity-a critical regulator of the proteolytic output of these organelles-as a novel biomarker of aging in C. elegans The increase in lysosomal pH in older worms is not a passive consequence of aging, but instead is timed with the cessation of reproduction, and correlates with the reduction in proteostasis in early adult life. Our results further implicate the steroid signaling pathway and DAF-16 in dynamically regulating lysosomal pH in the intestine of wild-type worms in response to the reproductive cycle. In the intestine of reproducing worms, DAF-16 promotes acidic lysosomes by upregulating the expression of v-ATPase genes. These findings support a model in which protein clearance in the soma is linked to reproduction in the gonad via the active regulation of lysosomal acidification. Copyright © 2017 by the Genetics Society of America.

Interaction of environment and reproductive processes in cattle

International Nuclear Information System (INIS)

Thatcher, W.W.; Collier, R.J.; Beede, D.K.; Wilcox, C.J.

1986-01-01

Effects of environment on reproductive processes of female cattle are described. Variation in fertility responses is divided into environmental and genetic effects. Environmental effects are defined as all effects non-genetic, and emphasis is placed on the quantitation of various climatic measurements (e.g. maximum environmental temperature) associated with reproductive performance. Sensitivities of various reproductive events to thermal stress are defined and include such responses as: reproductive behaviour; hormonal balance related to both reproductive events and metabolic adaptations; alterations in uterine blood flow; embryonic death; conceptus development; placental function; and restoration of postpartum reproductive function. Also discussed are several management strategies to improve animal productivity, including environmental modification and the potential for genetic development of less heat-sensitive animals. (author)

Kisspeptin and energy balance in reproduction.

Science.gov (United States)

De Bond, Julie-Ann P; Smith, Jeremy T

2014-03-01

Kisspeptin is vital for the neuroendocrine regulation of GNRH secretion. Kisspeptin neurons are now recognized as a central pathway responsible for conveying key homeostatic information to GNRH neurons. This pathway is likely to mediate the well-established link between energy balance and reproductive function. Thus, in states of severely altered energy balance (either negative or positive), fertility is compromised, as is Kiss1 expression in the arcuate nucleus. A number of metabolic modulators have been proposed as regulators of kisspeptin neurons including leptin, ghrelin, pro-opiomelanocortin (POMC), and neuropeptide Y (NPY). Whether these regulate kisspeptin neurons directly or indirectly will be discussed. Moreover, whether the stimulatory role of leptin on reproduction is mediated by kisspeptin directly will be questioned. Furthermore, in addition to being expressed in GNRH neurons, the kisspeptin receptor (Kiss1r) is also expressed in other areas of the brain, as well as in the periphery, suggesting alternative roles for kisspeptin signaling outside of reproduction. Interestingly, kisspeptin neurons are anatomically linked to, and can directly excite, anorexigenic POMC neurons and indirectly inhibit orexigenic NPY neurons. Thus, kisspeptin may have a direct role in regulating energy balance. Although data from Kiss1r knockout and WT mice found no differences in body weight, recent data indicate that kisspeptin may still play a role in food intake and glucose homeostasis. Thus, in addition to regulating reproduction, and mediating the effect of energy balance on reproductive function, kisspeptin signaling may also be a direct regulator of metabolism.

How endangered is sexual reproduction of high-mountain plants by summer frosts? Frost resistance, frequency of frost events and risk assessment.

Science.gov (United States)

Ladinig, Ursula; Hacker, Jürgen; Neuner, Gilbert; Wagner, Johanna

2013-03-01

at higher elevations. It appears that ice tolerance in reproductive structures is an advantage but not an absolute precondition for colonizing high altitudes with frequent frost events.

TGF-beta Sma/Mab signaling mutations uncouple reproductive aging from somatic aging.

Directory of Open Access Journals (Sweden)

Shijing Luo

2009-12-01

Full Text Available Female reproductive cessation is one of the earliest age-related declines humans experience, occurring in mid-adulthood. Similarly, Caenorhabditis elegans' reproductive span is short relative to its total life span, with reproduction ceasing about a third into its 15-20 day adulthood. All of the known mutations and treatments that extend C. elegans' reproductive period also regulate longevity, suggesting that reproductive span is normally linked to life span. C. elegans has two canonical TGF-beta signaling pathways. We recently found that the TGF-beta Dauer pathway regulates longevity through the Insulin/IGF-1 Signaling (IIS pathway; here we show that this pathway has a moderate effect on reproductive span. By contrast, TGF-beta Sma/Mab signaling mutants exhibit a substantially extended reproductive period, more than doubling reproductive span in some cases. Sma/Mab mutations extend reproductive span disproportionately to life span and act independently of known regulators of somatic aging, such as Insulin/IGF-1 Signaling and Dietary Restriction. This is the first discovery of a pathway that regulates reproductive span independently of longevity and the first identification of the TGF-beta Sma/Mab pathway as a regulator of reproductive aging. Our results suggest that longevity and reproductive span regulation can be uncoupled, although they appear to normally be linked through regulatory pathways.

On the dynamics of implicit emotion regulation: counter-regulation after remembering events of high but not of low emotional intensity.

Science.gov (United States)

Schwager, Susanne; Rothermund, Klaus

2014-01-01

Valence biases in attention allocation were assessed after remembering positive or negative personal events that were either still emotionally hot or to which the person had already adapted psychologically. Differences regarding the current state of psychological adjustment were manipulated experimentally by instructing participants to recall distant vs. recent events (Experiment 1) or affectively hot events vs. events to which the person had accommodated already (Experiment 2). Valence biases in affective processing were measured with a valence search task. Processes of emotional counter-regulation (i.e., attention allocation to stimuli of opposite valence to the emotional event) were elicited by remembering affectively hot events, whereas congruency effects (i.e., attention allocation to stimuli of the same valence as the emotional event) were obtained for events for which a final appraisal had already been established. The results of our study help to resolve conflicting findings from the literature regarding congruent vs. incongruent effects of remembering emotional events on affective processing. We discuss implications of our findings for the conception of emotions and for the dynamics of emotion regulation processes.

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.

32 CFR 2700.43 - Reproduction controls.

Science.gov (United States)

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Reproduction controls. 2700.43 Section 2700.43... SECURITY INFORMATION REGULATIONS Safeguarding § 2700.43 Reproduction controls. OMSN and SLNO shall maintain records to show the number and distribution of all OMSN originated classified documents. Reproduction of...

[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.

Insulin: its role in the central control of reproduction.

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Sliwowska, Joanna H; Fergani, Chrysanthi; Gawałek, Monika; Skowronska, Bogda; Fichna, Piotr; Lehman, Michael N

2014-06-22

Insulin has long been recognized as a key regulator of energy homeostasis via its actions at the level of the brain, but in addition, plays a role in regulating neural control of reproduction. In this review, we consider and compare evidence from animal models demonstrating a role for insulin for physiological control of reproduction by effects on GnRH/LH secretion. We also review the role that insulin plays in prenatal programming of adult reproduction, and consider specific candidate neurons in the adult hypothalamus by which insulin may act to regulate reproductive function. Finally, we review clinical evidence of the role that insulin may play in adult human fertility and reproductive disorders. Overall, while insulin appears to have a significant impact on reproductive neuroendocrine function, there are many unanswered questions regarding its precise sites and mechanisms of action, and their impact on developing and adult reproductive neuroendocrine function. Copyright © 2014 Elsevier Inc. All rights reserved.

Regulation of the activins-follistatins-inhibins axis by energy status: Impact on reproductive function.

Science.gov (United States)

Perakakis, Nikolaos; Upadhyay, Jagriti; Ghaly, Wael; Chen, Joyce; Chrysafi, Pavlina; Anastasilakis, Athanasios D; Mantzoros, Christos S

2018-05-09

We have previously demonstrated that the adipose tissue derived hormone leptin controls reproductive function by regulating the hypothalamic-pituitary-gonadal axis in response to energy deficiency. Here, we evaluate the activins-follistatins-inhibins (AFI) axis during acute (short-term fasting in healthy people) and chronic energy deficiency (women with hypothalamic amenorrhea due to strenuous exercise [HA]) and investigate their relation to leptin and reproductive function in healthy subjects and subjects with HA. The AFI axis was investigated in: a) A double-blinded study in healthy subjects having three randomly assigned admissions, each time for four days: in the isocaloric fed state, complete fasting with placebo treatment, complete fasting with leptin replacement, b) A case-control study comparing women with HA vs healthy controls, c) An open-label interventional study investigating leptin treatment in women with HA over a period of up to three months, d) A randomized interventional trial investigating leptin treatment vs placebo in women with HA for nine months. The circulating levels of activin A, activin B, follistatin and follistatin-like 3 change robustly in response to acute and chronic energy deficiency. Leptin replacement in acute energy deprivation does not affect the levels of these hormones suggesting an independent regulation by these two hormonal pathways. In chronic energy deficiency, leptin replacement restores only activin B levels, which are in turn associated with an increase in the number of dominant follicles. We demonstrate for the first time that the AFI axis is affected both by acute and chronic energy deficiency. Partial restoration of a component of the axis, i.e. activin B only, through leptin replacement is associated with improved reproductive function in women with HA. Copyright © 2018. Published by Elsevier Inc.

Social context and reproductive potential affect worker reproductive decisions in a eusocial insect.

Directory of Open Access Journals (Sweden)

Boris Yagound

Full Text Available Context-dependent decision-making conditions individual plasticity and is an integrant part of alternative reproductive strategies. In eusocial Hymenoptera (ants, bees and wasps, the discovery of worker reproductive parasitism recently challenged the view of workers as a homogeneous collective entity and stressed the need to consider them as autonomous units capable of elaborate choices which influence their fitness returns. The reproductive decisions of individual workers thus need to be investigated and taken into account to understand the regulation of reproduction in insect societies. However, we know virtually nothing about the proximate mechanisms at the basis of worker reproductive decisions. Here, we test the hypothesis that the capacity of workers to reproduce in foreign colonies lies in their ability to react differently according to the colonial context and whether this reaction is influenced by a particular internal state. Using the bumble bee Bombus terrestris, we show that workers exhibit an extremely high reproductive plasticity which is conditioned by the social context they experience. Fertile workers reintroduced into their mother colony reverted to sterility, as expected. On the contrary, a high level of ovary activity persisted in fertile workers introduced into a foreign nest, and this despite more frequent direct contacts with the queen and the brood than control workers. Foreign workers' reproductive decisions were not affected by the resident queen, their level of fertility being similar whether or not the queen was removed from the host colony. Workers' physiological state at the time of introduction is also of crucial importance, since infertile workers failed to develop a reproductive phenotype in a foreign nest. Therefore, both internal and environmental factors appear to condition individual reproductive strategies in this species, suggesting that more complex decision-making mechanisms are involved in the regulation

Toxic plants: Effects on reproduction and fetal and embryonic development in livestock

Science.gov (United States)

Reproductive success is dependent on a large number of carefully orchestrated biological events that must occur in a specifically timed sequence. The interference with one of more of these sequences or events may result in total reproductive failure or a more subtle reduction in reproductive potent...

Updates in Reproduction Coming from the Endocannabinoid System

Science.gov (United States)

Bradshaw, Heather B.

2014-01-01

The endocannabinoid system (ECS) is an evolutionarily conserved master system deeply involved in the central and local control of reproductive functions in both sexes. The tone of these lipid mediators—deeply modulated by the activity of biosynthetic and hydrolyzing machineries—regulates reproductive functions from gonadotropin discharge and steroid biosynthesis to the formation of high quality gametes and successful pregnancy. This review provides an overview on ECS and reproduction and focuses on the insights in the regulation of endocannabinoid production by steroids, in the regulation of male reproductive activity, and in placentation and parturition. Taken all together, evidences emerge that the activity of the ECS is crucial for procreation and may represent a target for the therapeutic exploitation of infertility. PMID:24550985

Updates in Reproduction Coming from the Endocannabinoid System

Directory of Open Access Journals (Sweden)

Rosaria Meccariello

2014-01-01

Full Text Available The endocannabinoid system (ECS is an evolutionarily conserved master system deeply involved in the central and local control of reproductive functions in both sexes. The tone of these lipid mediators—deeply modulated by the activity of biosynthetic and hydrolyzing machineries—regulates reproductive functions from gonadotropin discharge and steroid biosynthesis to the formation of high quality gametes and successful pregnancy. This review provides an overview on ECS and reproduction and focuses on the insights in the regulation of endocannabinoid production by steroids, in the regulation of male reproductive activity, and in placentation and parturition. Taken all together, evidences emerge that the activity of the ECS is crucial for procreation and may represent a target for the therapeutic exploitation of infertility.

Influence of a water regulation event on the age of Yellow River water in the Bohai

Science.gov (United States)

Li, Zhen; Wang, Haiyan; Guo, Xinyu; Liu, Zhe; Gao, Huiwang; Zhang, Guiling

2017-10-01

Abrupt changes in freshwater inputs from large rivers usually imply regime shifts in coastal water environments. The influence of a water regulation event on the age of the Yellow River water in the Bohai was modeled using constituent-oriented age and residence time theory to better understand the change in the environmental function of the hydrodynamic field owing to human activities. The water ages in Laizhou Bay, the central basin, and the Bohai strait are sensitive to water regulation. The surface ages in those areas can decrease by about 300 days, particularly in July, and the age stratification is also strengthened. A water regulation event can result in declines in the water age in early July ahead of declines in the water age under climatological conditions (without the regulation event) by about 1 and 5 months in the central basin and Laizhou Bay, respectively. The change in the coastal circulation due to the water regulation event is the primary reason for the change in the Yellow River water age. The high Yellow River flow rate can enhance the density flow and, therefore, reduce the age of the Yellow River water. The subsequent impact of a single water regulation event can last about 1.0 to 4.0 years in different subregions.

Mammalian target of rapamycin (mTOR): a central regulator of male fertility?

Science.gov (United States)

Jesus, Tito T; Oliveira, Pedro F; Sousa, Mário; Cheng, C Yan; Alves, Marco G

2017-06-01

Mammalian target of rapamycin (mTOR) is a central regulator of cellular metabolic phenotype and is involved in virtually all aspects of cellular function. It integrates not only nutrient and energy-sensing pathways but also actin cytoskeleton organization, in response to environmental cues including growth factors and cellular energy levels. These events are pivotal for spermatogenesis and determine the reproductive potential of males. Yet, the molecular mechanisms by which mTOR signaling acts in male reproductive system remain a matter of debate. Here, we review the current knowledge on physiological and molecular events mediated by mTOR in testis and testicular cells. In recent years, mTOR inhibition has been explored as a prime strategy to develop novel therapeutic approaches to treat cancer, cardiovascular disease, autoimmunity, and metabolic disorders. However, the physiological consequences of mTOR dysregulation and inhibition to male reproductive potential are still not fully understood. Compelling evidence suggests that mTOR is an arising regulator of male fertility and better understanding of this atypical protein kinase coordinated action in testis will provide insightful information concerning its biological significance in other tissues/organs. We also discuss why a new generation of mTOR inhibitors aiming to be used in clinical practice may also need to include an integrative view on the effects in male reproductive system.

75 FR 38411 - Drawbridge Operation Regulations; Charles River, Boston, MA, Public Event

Science.gov (United States)

2010-07-02

... Operation Regulations; Charles River, Boston, MA, Public Event AGENCY: Coast Guard, DHS. ACTION: Notice of..., telephone 202-366-9826. SUPPLEMENTARY INFORMATION: The Craigie Bridge, across the Charles River at mile 1.0... elevation above the Charles River Dam. The existing drawbridge operation regulations are listed at 33 CFR...

Corticosterone mediated costs of reproduction link current to future breeding.

Science.gov (United States)

Crossin, Glenn T; Phillips, Richard A; Lattin, Christine R; Romero, L Michael; Williams, Tony D

2013-11-01

Life-history theory predicts that costs are associated with reproduction. One possible mediator of costs involves the secretion of glucocorticoid hormones, which in birds can be measured in feathers grown during the breeding period. Glucocorticoids mediate physiological responses to unpredictable environmental or other stressors, but they can also function as metabolic regulators during more predictable events such as reproduction. Here we show that corticosterone ("Cort") in feathers grown during the breeding season reflects reproductive effort in two Antarctic seabird species (giant petrels, Macronectes spp.). In females of both species, but not males, feather Cort ("fCort") was nearly 1.5-fold higher in successful than failed breeders (those that lost their eggs/chicks), suggesting a cost of successful reproduction, i.e., high fCort levels in females reflect the elevated plasma Cort levels required to support high metabolic demands of chick-rearing. Successful breeding also led to delayed moult prior to winter migration. The fCort levels and pre-migration moult score that we measured at the end of current breeding were predictive of subsequent reproductive effort in the following year. Birds with high fCort and a delayed initiation of moult were much more likely to defer breeding in the following year. Cort levels and the timing of moult thus provide a potential mechanism for the tradeoff between current and future reproduction. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Chance, choice, and the future of reproduction.

Science.gov (United States)

Miller, W B

1983-11-01

The evolution of reproduction has been characterized by the development of complex biological and behavioral mechanisms that serve to regulate chance events. Human reproduction has been characterized by the increasing importance of individual choice. Some contemporary manifestations of this broad trend are the high incidence of contraceptive and "proceptive" behavior among couples in Western, industrialized nations. The former behavior willingly attempts to prevent conception while the latter actively attempts to induce conception (such as concentrating intercourse around the time of ovulation). Both patterns of behavior indicate that a choice is being made. A 3-year study of 1000 women revealed proceptive behavior as the most important factor predicting occurance of conception among married couples in the United States. The general strategeis people follow while making childbearing decisions: termination, sequencing, and pre-planning form a continuum following the historical trend toward greater reproductive control. In the terminating strategy, a couple makes no decision about child bearing until the number of children they have become enough or too much. In the sequencing strategy, decisions to have children are made 1 child at a time until a satisfactory limit is reached. In the pre-planning strategy, a plan is worked out ahead of time and is subsequently carried out. As new reproductive technology is introduced and as progressive change is made in society's reproductive related values and beliefs, choice will continue to dominate chance as the highly likely trend for the future of reproduction. Surrogate maternity is just 1 example of this trend. However, these new options, which culminate in the theory and practice of "progensis," (still in its infancy), as well as offering a rich opportunity, can also incur psychological burdens on a couple. Thus, as with any kind of freedom, these developments will require care, caution and responsibility.

Serotonin Regulates the Feeding and Reproductive Behaviors of Pratylenchus penetrans.

Science.gov (United States)

Han, Ziduan; Boas, Stephanie; Schroeder, Nathan E

2017-07-01

The success of all plant-parasitic nematodes is dependent on the completion of several complex behaviors. The lesion nematode Pratylenchus penetrans is an economically important parasite of a diverse range of plant hosts. Unlike the cyst and root-knot nematodes, P. penetrans moves both within and outside of the host roots and can feed from both locations. Adult females of P. penetrans require insemination by actively moving males for reproduction and can lay eggs both within and outside of the host roots. We do not have a complete understanding of the molecular basis for these behaviors. One candidate modulator of these behaviors is the neurotransmitter serotonin. Previous research demonstrated an effect of exogenously applied serotonin on the feeding and male mating behaviors of cyst and root-knot nematodes. However, there are no data on the role of exogenous serotonin on lesion nematodes. Similarly, there are no data on the presence and function of endogenous serotonin in any plant-parasitic nematode. Here, we establish that exogenous serotonin applied to P. penetrans regulates both feeding and sex-specific behaviors. Furthermore, using immunohistochemistry and pharmacological assays, our data suggest that P. penetrans utilizes endogenous serotonin to regulate both feeding and sex-specific behaviors.

THE DISCOUNTED REPRODUCTIVE NUMBER FOR EPIDEMIOLOGY

OpenAIRE

Reluga, Timothy C.; Medlock, Jan; Galvani, Alison

2009-01-01

The basic reproductive number, , and the effective reproductive number, , are commonly used in mathematical epidemiology as summary statistics for the size and controllability of epidemics. However, these commonly used reproductive numbers can be misleading when applied to predict pathogen evolution because they do not incorporate the impact of the timing of events in the life-history cycle of the pathogen. To study evolution problems where the host population size is changing, measur...

[Influencing factors for reproductive health of female workers in petrochemical industry].

Science.gov (United States)

Kou, Z X; Wang, S L; Chen, Z L; He, Y H; Yu, W L; Mei, L Y; Zhang, H D

2018-02-20

Objective: To investigate the reproductive health status of female workers in petrochemical industry, and to provide a reference for improving reproductive health status and developing preventive and control measures for female workers in petrochemical industry. Methods: A face-to-face questionnaire survey was performed from January to October, 2016. The Questionnaire on Women's Reproductive Health was used to investigate the reproductive health of female workers in petrochemical industry. The multivariate logistic regression model was used to identify the influencing factors for reproductive health of female workers in petrochemical industry. Results: Among the 7485 female workers, 1 268 (40.9%) had abnormal menstrual period, 1 437 (46.4%) had abnormal menstrual volume, 177 (28.5%) had hyperplasia of mammary glands, and 1 807 (24.6%) had gynecological inflammation. The reproductive system diseases in female workers in petrochemical industry were associated with the factors including age, marital status, education level, unhealthy living habits, abortion, overtime work, work shift, workload, video operation, occupational exposure, positive events, and negative events, and among these factors, negative events (odds ratio[ OR ]= 1.856) , unhealthy living habits ( OR =1.542) , and positive events ( OR =1.516) had greater impact on reproductive system diseases. Conclusion: Many chemical substances in the occupational environment of petrochemical industry can cause damage to the reproductive system, which not only affects the health of the female workers, but also poses potential threats to the health of their offspring. Occupational exposure, unhealthy living habits, overtime work, and work shift have great influence on reproductive system diseases in female workers.

Melatonin and female reproduction.

Science.gov (United States)

Tamura, Hiroshi; Takasaki, Akihisa; Taketani, Toshiaki; Tanabe, Manabu; Lee, Lifa; Tamura, Isao; Maekawa, Ryo; Aasada, Hiromi; Yamagata, Yoshiaki; Sugino, Norihiro

2014-01-01

Melatonin (N-acetyl-5-methoxytryptamine) is secreted during the dark hours at night by the pineal gland. After entering the circulation, melatonin acts as an endocrine factor and a chemical messenger of light and darkness. It regulates a variety of important central and peripheral actions related to circadian rhythms and reproduction. It also affects the brain, immune, gastrointestinal, cardiovascular, renal, bone and endocrine functions and acts as an oncostatic and anti-aging molecule. Many of melatonin's actions are mediated through interactions with specific membrane-bound receptors expressed not only in the central nervous system, but also in peripheral tissues. Melatonin also acts through non-receptor-mediated mechanisms, for example serving as a scavenger for reactive oxygen species and reactive nitrogen species. At both physiological and pharmacological concentrations, melatonin attenuates and counteracts oxidative stress and regulates cellular metabolism. Growing scientific evidence of reproductive physiology supports the role of melatonin in human reproduction. This review was conducted to investigate the effects of melatonin on female reproduction and to summarize our findings in this field. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.

Reproductive endocrinology of llamas and alpacas.

Science.gov (United States)

Bravo, P W

1994-07-01

The physiology of reproduction with emphasis in endocrinology of llamas and alpacas is addressed. Basic concepts of ovarian follicular dynamics, endocrine events associated with induction of ovulation, corpus luteum formation, pregnancy, parturition, postpartum interval, puberty, and sexual behavior on the female are reviewed. Pathologic conditions of the reproductive process are also reviewed.

Measuring students' self-regulated learning in professional education: bridging the gap between event and aptitude measurements.

Science.gov (United States)

Endedijk, Maaike D; Brekelmans, Mieke; Sleegers, Peter; Vermunt, Jan D

Self-regulated learning has benefits for students' academic performance in school, but also for expertise development during their professional career. This study examined the validity of an instrument to measure student teachers' regulation of their learning to teach across multiple and different kinds of learning events in the context of a postgraduate professional teacher education programme. Based on an analysis of the literature, we developed a log with structured questions that could be used as a multiple-event instrument to determine the quality of student teachers' regulation of learning by combining data from multiple learning experiences. The findings showed that this structured version of the instrument measured student teachers' regulation of their learning in a valid and reliable way. Furthermore, with the aid of the Structured Learning Report individual differences in student teachers' regulation of learning could be discerned. Together the findings indicate that a multiple-event instrument can be used to measure regulation of learning in multiple contexts for various learning experiences at the same time, without the necessity of relying on students' ability to rate themselves across all these different experiences. In this way, this instrument can make an important contribution to bridging the gap between two dominant approaches to measure SRL, the traditional aptitude and event measurement approach.

76 FR 36308 - Special Local Regulation for Marine Events; Temporary Change of dates for Recurring Marine Events...

Science.gov (United States)

2011-06-22

... hour, make special local regulations necessary. However, the Coast Guard will provide advance... dangers posed by hydroplane speed boats, operating in speeds excess of 150 miles per hour, make special... includes but is not limited to sail boat regattas, boat parades, power boat racing, swimming events, crew...

[Phenotypic plasticity and its regulation of tillers prolonged reproductive growth of Puccinellia tenuiflora population on alkalized meadow in Songnen Plains of China].

Science.gov (United States)

Sun, Ju; Yang, Yun-Fei

2007-04-01

Puccinellia tenuiflora is a salt-tolerant plant of grass family. By the method of random sampling, big samples of reproductive tillers of P. tenuiflora population on the alkalized meadow in the Songnen Plains of China were collected at early heading, heading, flowering, and milky stages, respectively, and the plasticity of their quantitative characters was analyzed. The results showed that except some fluctuations at flowering stage, the tiller height, tiller biomass, spike length and spike biomass of the reproductive tillers at other three growth stages increased significantly every five days with the increasing time of reproductive growth. At each growth stage, tiller height had a significant positive correlation with spike biomass, but a negative correlation with reproductive allocation. With the time of reproductive growth prolonged, the increasing rate of spike biomass at early heading, flowering and milky stages increased in power function with the increase of tiller height. The reproductive allocation decreased linearly by 43.2% and 44.31% at early heading and heading stages, respectively when the reproductive growth time increased ten days, and by 130% at milky stage when the time increased five days. The regulation of the tiller phenotypic plasticity of P. tenuiflora population at its reproductive growth stage followed definite patterns.

The current state of research in the field of reproductive behavior of spouses’ regulation

Directory of Open Access Journals (Sweden)

Maria M. Danina

2016-06-01

Full Text Available The article provides an overview of the socio-demographic, socio-economic and psychological approaches to the study of reproductive behavior of spouses carried out over the last 30 years. Two categories of concepts that explain the determination of decisions on childbearing are regarded: rational-pragmatic and hedonistic. The trends in the development of this field of knowledge are as follows: 1 overcoming economical-oriented logic in explaining the factors and determinants of the decision making process; 2 individual psychological factors study in addition to the traditional socio-psychological analysis of the determination of childbirth; 3 the transition from studying the context of decisions about childbirth to the analysis of their role and place in the context of the person biography. The analysis of the concepts and empirical studies helps not only to reveal a massive shift of professional interest from economic and demographic factors to psychological ones, but also to have a better understanding of socio-cultural and psychological and value determined roots of that shift. Nowadays, in contrast to biological patterns and established traditions, a personal or family decision about bearing a child is becoming more and more conscious. Particular attention is paid to the concept of mental regulation of reproductive behavior that is developed at the intersection of psychology of reproductive behavior, psychology of parenthood and individual psychology. The supportive argument is that new objects of study are considered, such as voluntarily childless families, parents at risk, same-sex families.

48 CFR 2452.208-71 - Reproduction of reports.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Reproduction of reports... 2452.208-71 Reproduction of reports. As prescribed in 2437.110(b), insert the following clause in... other written materials. Reproduction of Reports (APR 1984) In accordance with Title I of the Government...

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.

The regulation of science and the Charter of Rights: would a ban on non-reproductive human cloning unjustifiably violate freedom of expression?

Science.gov (United States)

Billingsley, Barbara; Caulfield, Timothy

2004-01-01

Non-Reproductive Human Cloning (NRHC) allows researchers to develop and clone cells, including non-reproductive cells, and to research the etiology and transmission of disease. The ability to clone specific stem cells may also allow researchers to clone cells with genetic defects and analyze those cells with more precisions. Despite those potential benefits, Parliament has banned such cloning due to a myriad of social and ethical concerns. In May 2002, the Canadian Government introduced Bill C-13 on assisted human reproductive technologies. Bill C-13 deals with both the scientific and the clinical use of human reproductive materials, and it prohibits a number of other activities, including NRHC. Although the Supreme Court of Canada has never ruled on whether scientific experiments area form of expression, academic support exists for this notion. The authors go through the legal analysis that would be required to find that scientific experiments are expression, focusing in part on whether NRHC could be considered violent and thus fall outside the protection of section 2(b). The latter question is complicated by the ongoing policy debate over whether an "embryonic cell" is property of human life. The authors then consider whether a ban on NRHC could be justified under section 1 of the Charter. They conclude that both the breadth of the legislative purpose and the proportionality of the measure are problematic. Proportionality is a specific concern because the ban could be viewed as an outright denial of scientific freedom of expression. Although consistent with current jurisprudence on freedom of expression, this paper runs against the flow of government policy in the areas of regulation and prohibition of non-reproductive human cloning. As there has been no Charter litigation to date on whether scientific research is a form of expression, the authors introduce a new way of looking at the legality of the regulation of new reproductive technologies.

15 CFR 762.5 - Reproduction of original records.

Science.gov (United States)

2010-01-01

... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Reproduction of original records. 762... RECORDKEEPING § 762.5 Reproduction of original records. (a) The regulated person may maintain reproductions instead of the original records provided all of the requirements of paragraph (b) of this section are met...

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

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

Compliance with Environmental Regulations through Complex Geo-Event Processing

Directory of Open Access Journals (Sweden)

Federico Herrera

2017-11-01

Full Text Available In a context of e-government, there are usually regulatory compliance requirements that support systems must monitor, control and enforce. These requirements may come from environmental laws and regulations that aim to protect the natural environment and mitigate the effects of pollution on human health and ecosystems. Monitoring compliance with these requirements involves processing a large volume of data from different sources, which is a major challenge. This volume is also increased with data coming from autonomous sensors (e.g. reporting carbon emission in protected areas and from citizens providing information (e.g. illegal dumping in a voluntary way. Complex Event Processing (CEP technologies allow processing large amount of event data and detecting patterns from them. However, they do not provide native support for the geographic dimension of events which is essential for monitoring requirements which apply to specific geographic areas. This paper proposes a geospatial extension for CEP that allows monitoring environmental requirements considering the geographic location of the processed data. We extend an existing platform-independent, model-driven approach for CEP adding the geographic location to events and specifying patterns using geographic operators. The use and technical feasibility of the proposal is shown through the development of a case study and the implementation of a prototype.

77 FR 18984 - Special Local Regulation for Marine Events; Yorktown Parade of Sail, York River; Yorktown, VA

Science.gov (United States)

2012-03-29

...-AA08 Special Local Regulation for Marine Events; Yorktown Parade of Sail, York River; Yorktown, VA... proposes to establish special local regulation during the Yorktown Parade of Sail, a parade of five tall... sponsor the ``Yorktown Parade of Sail'' on the waters of York River. The event will consist of...

The Mahabharata and reproductive endocrinology

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Bharti Kalra

2016-01-01

Full Text Available This communication approaches the Mahabharata through the prism of reproductive endocrinology. Descriptions of episodes related to reproduction are listed here, to provide fodder for the endocrinologically minded brain. The cases described here are perhaps, the first documented observations of fetal orgasm, pseudocyesis and assisted reproductive technology, including assisted insemination by donor, induction of ovulation, and in vitro fertilization as well as precocious growth and intersex. We do not presume to offer a definite explanation for these interesting episodes from the Mahabharata. We do, however, hope to stimulate interest in ancient Indian literature, and encourage a literary “forensic endocrine” analysis of events relevant to our specialty.

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

The Effect of Latitudinal Variation on Shrimp Reproductive Strategies.

Science.gov (United States)

van de Kerk, Madelon; Jones Littles, Chanda; Saucedo, Omar; Lorenzen, Kai

2016-01-01

Reproductive strategies comprise the timing and frequency of reproductive events and the number of offspring per reproductive event, depending on factors such as climate conditions. Therefore, species that exhibit plasticity in the allocation of reproductive effort can alter their behavior in response to climate change. Studying how the reproductive strategy of species varies along the latitudinal gradient can help us understand and predict how they will respond to climate change. We investigated the effects of the temporal allocation of reproductive effort on the population size of brown shrimp (Farfantepenaeus aztecus) along a latitudinal gradient. Multiple shrimp species exhibit variation in their reproductive strategies, and given the economic importance of brown shrimp to the commercial fishing sector of the Unites States, changes in the timing of their reproduction could have significant economic and social consequences. We used a stage-based, density-dependent matrix population model tailored to the life history of brown shrimp. Shrimp growth rates and environmental carrying capacity were varied based on the seasonal climate conditions at different latitudes, and we estimated the population size at equilibrium. The length of the growing season increased with decreasing latitude and the reproductive strategy leading to the highest population size changed from one annual birth pulse with high reproductive output to continuous low-output reproduction. Hence, our model confirms the classical paradigm of continuous reproduction at low latitudes, with increased seasonality of the breeding period towards the poles. Our results also demonstrate the potential for variation in climate to affect the optimal reproductive strategy for achieving maximum population sizes. Certainly, understanding these dynamics may inform more comprehensive management strategies for commercially important species like brown shrimp.

The Effect of Latitudinal Variation on Shrimp Reproductive Strategies.

Directory of Open Access Journals (Sweden)

Madelon van de Kerk

Full Text Available Reproductive strategies comprise the timing and frequency of reproductive events and the number of offspring per reproductive event, depending on factors such as climate conditions. Therefore, species that exhibit plasticity in the allocation of reproductive effort can alter their behavior in response to climate change. Studying how the reproductive strategy of species varies along the latitudinal gradient can help us understand and predict how they will respond to climate change. We investigated the effects of the temporal allocation of reproductive effort on the population size of brown shrimp (Farfantepenaeus aztecus along a latitudinal gradient. Multiple shrimp species exhibit variation in their reproductive strategies, and given the economic importance of brown shrimp to the commercial fishing sector of the Unites States, changes in the timing of their reproduction could have significant economic and social consequences. We used a stage-based, density-dependent matrix population model tailored to the life history of brown shrimp. Shrimp growth rates and environmental carrying capacity were varied based on the seasonal climate conditions at different latitudes, and we estimated the population size at equilibrium. The length of the growing season increased with decreasing latitude and the reproductive strategy leading to the highest population size changed from one annual birth pulse with high reproductive output to continuous low-output reproduction. Hence, our model confirms the classical paradigm of continuous reproduction at low latitudes, with increased seasonality of the breeding period towards the poles. Our results also demonstrate the potential for variation in climate to affect the optimal reproductive strategy for achieving maximum population sizes. Certainly, understanding these dynamics may inform more comprehensive management strategies for commercially important species like brown shrimp.

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 ...

77 FR 6954 - Special Local Regulations; Safety and Security Zones; Recurring Events in Captain of the Port...

Science.gov (United States)

2012-02-10

... necessary security zone, and (3) updating and reorganizing existing regulations for ease of use and... provide the event name, and type, as well as locations of the events. Annual notifications will be made to..., before the effective period, the Coast Guard will issue notice of the time and location of each regulated...

Resource allocation to reproduction in animals.

Science.gov (United States)

Kooijman, Sebastiaan A L M; Lika, Konstadia

2014-11-01

The standard Dynamic Energy Budget (DEB) model assumes that a fraction κ of mobilised reserve is allocated to somatic maintenance plus growth, while the rest is allocated to maturity maintenance plus maturation (in embryos and juveniles) or reproduction (in adults). All DEB parameters have been estimated for 276 animal species from most large phyla and all chordate classes. The goodness of fit is generally excellent. We compared the estimated values of κ with those that would maximise reproduction in fully grown adults with abundant food. Only 13% of these species show a reproduction rate close to the maximum possible (assuming that κ can be controlled), another 4% have κ lower than the optimal value, and 83% have κ higher than the optimal value. Strong empirical support hence exists for the conclusion that reproduction is generally not maximised. We also compared the parameters of the wild chicken with those of races selected for meat and egg production and found that the latter indeed maximise reproduction in terms of κ, while surface-specific assimilation was not affected by selection. We suggest that small values of κ relate to the down-regulation of maximum body size, and large values to the down-regulation of reproduction. We briefly discuss the ecological context for these findings. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

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)

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

Women's empowerment and reproductive experiences over the lifecourse.

Science.gov (United States)

Lee-Rife, Susan M

2010-08-01

This paper examines the complex interplay between reproductive experiences and women's empowerment using rich life history data from a survey in India. Previous research has examined the influence of a rather limited range of reproductive events, focusing on how many children or sons a woman has borne, and has only superficially incorporated the insights of lifecourse theory. Furthermore, it has often conceptualized empowerment as a static characteristic rather than a time-varying one, and has often failed to examine the influence of empowerment resources or previous empowerment levels. I focus on the cumulative influence of less-studied reproductive events-including unwanted or mistimed pregnancy, stillbirths, miscarriages, and abortions-on several dimensions of women's empowerment, including mobility, financial decision-making, experiences of violence, and threats of abandonment or homelessness using data collected from 2435 women in Madhya Pradesh, India during a 2002 household-based probability sample survey. Logistic regression revealed that, notably, few reproductive events have an impact on women's current empowerment, but rather, the extent of empowerment immediately after marriage emerges as a strong determinant of their current empowerment. However, women who have had abortions have higher odds of experiencing domestic violence, and experiencing mistimed pregnancies lowers the odds of violence. Incorporating the potential influence of prior life events and conditions, accounting for the possibility that experiences may accumulate to shape women's current empowerment portrays women's lives more completely and helps to identify key points of intervention. Copyright 2010 Elsevier Ltd. All rights reserved.

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

Male reproductive health and yoga

Directory of Open Access Journals (Sweden)

Pallav Sengupta

2013-01-01

Full Text Available Now-a-days reproductive health problems along with infertility in male is very often observed. Various Assisted Reproductive Technologies have been introduced to solve the problem, but common people cannot afford the cost of such procedures. Various ayurvedic and other alternative medicines, along with regular yoga practice are proven to be not only effective to enhance the reproductive health in men to produce a successful pregnancy, but also to regulate sexual desire in men who practice celibacy. Yoga is reported to reduce stress and anxiety, improve autonomic functions by triggering neurohormonal mechanisms by the suppression of sympathetic activity, and even, today, several reports suggested regular yoga practice from childhood is beneficial for reproductive health. In this regard the present review is aimed to provide all the necessary information regarding the effectiveness of yoga practice to have a better reproductive health and to prevent infertility.

75 FR 38411 - Drawbridge Operation Regulations; Chelsea River, Chelsea and East Boston, MA, Event-Road Race

Science.gov (United States)

2010-07-02

... Operation Regulations; Chelsea River, Chelsea and East Boston, MA, Event--Road Race AGENCY: Coast Guard, DHS... is necessary to facilitate a public event, the Chelsea River Revel 5K Road Race. DATES: This... public event, the Chelsea River Revel 5K Road Race. This deviation allows the bridge to remain closed...

The effects of an "El Niño" southern oscillation event on reproduction in male and female blue-footed boobies, Sula nebouxii.

Science.gov (United States)

Wingfield, J C; Ramos-Fernandez, G; Nuñez-de la Mora, A; Drummond, H

1999-05-01

This study attempted to determine endocrine correlates of reproductive success in relation to major deleterious environmental conditions. In 1992, an El Niño southern oscillation event resulted in complete reproductive failure in a colony of blue-footed boobies, Sula nebouxi, on Isla Isabel in the Pacific Ocean off San Blas, Nayarit, Mexico (21.5 degrees N, 105.5 degrees W). In 1993, the El Niño event had waned and reproductive success was high. The mean sea surface temperature in 1992 was 26.69 degrees, the warmest year for 11 years of data (mean, 25.63 degrees ). In 1993, mean sea surface temperature was 25.75 degrees. Plasma levels of testosterone were highest during the egg-laying period in 1993 and declined markedly during incubation. There were no differences between males and females. Comparisons of testosterone levels between 1992 and 1993 (egg-laying time point removed for 1993) showed no significant differences. Thus reproductive failure during an El Niño year was not related to testosterone levels. Baseline plasma levels of corticosterone did not change over the nesting cycle in either sex. There was a trend for plasma levels of corticosterone to be higher in males and females during the earlier stages of breeding in 1992 compared with 1993, and if all levels were combined within years then females showed significantly higher plasma levels of corticosterone in the El Niño year. Plasma levels of corticosterone showed marked increases following capture and handling in both sexes and at every stage of the breeding cycle in each year. There was no variation in the adrenocortical responses to stress with year or stage of nesting in males. However, in females, maximum corticosterone levels were greatest during the parental phase of 1992, the El Niño year, when all nests ultimately failed. Comparisons of the dynamics of corticosterone changes during the capture stress protocol revealed no correlations with body mass in 1992 or 1993. These data suggest that

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.

Sex differences and emotion regulation: an event-related potential study.

Directory of Open Access Journals (Sweden)

Elyse K T Gardener

Full Text Available Difficulties in emotion regulation have been implicated as a potential mechanism underlying anxiety and mood disorders. It is possible that sex differences in emotion regulation may contribute towards the heightened female prevalence for these disorders. Previous fMRI studies of sex differences in emotion regulation have shown mixed results, possibly due to difficulties in discriminating the component processes of early emotional reactivity and emotion regulation. The present study used event-related potentials (ERPs to examine sex differences in N1 and N2 components (reflecting early emotional reactivity and P3 and LPP components (reflecting emotion regulation. N1, N2, P3, and LPP were recorded from 20 men and 23 women who were instructed to "increase," "decrease," and "maintain" their emotional response during passive viewing of negative images. Results indicated that women had significantly greater N1 and N2 amplitudes (reflecting early emotional reactivity to negative stimuli than men, supporting a female negativity bias. LPP amplitudes increased to the "increase" instruction, and women displayed greater LPP amplitudes than men to the "increase" instruction. There were no differences to the "decrease" instruction in women or men. These findings confirm predictions of the female negativity bias hypothesis and suggest that women have greater up-regulation of emotional responses to negative stimuli. This finding is highly significant in light of the female vulnerability for developing anxiety disorders.

Sex differences and emotion regulation: an event-related potential study.

Science.gov (United States)

Gardener, Elyse K T; Carr, Andrea R; Macgregor, Amy; Felmingham, Kim L

2013-01-01

Difficulties in emotion regulation have been implicated as a potential mechanism underlying anxiety and mood disorders. It is possible that sex differences in emotion regulation may contribute towards the heightened female prevalence for these disorders. Previous fMRI studies of sex differences in emotion regulation have shown mixed results, possibly due to difficulties in discriminating the component processes of early emotional reactivity and emotion regulation. The present study used event-related potentials (ERPs) to examine sex differences in N1 and N2 components (reflecting early emotional reactivity) and P3 and LPP components (reflecting emotion regulation). N1, N2, P3, and LPP were recorded from 20 men and 23 women who were instructed to "increase," "decrease," and "maintain" their emotional response during passive viewing of negative images. Results indicated that women had significantly greater N1 and N2 amplitudes (reflecting early emotional reactivity) to negative stimuli than men, supporting a female negativity bias. LPP amplitudes increased to the "increase" instruction, and women displayed greater LPP amplitudes than men to the "increase" instruction. There were no differences to the "decrease" instruction in women or men. These findings confirm predictions of the female negativity bias hypothesis and suggest that women have greater up-regulation of emotional responses to negative stimuli. This finding is highly significant in light of the female vulnerability for developing anxiety disorders.

RSPO1/β-catenin signaling pathway regulates oogonia differentiation and entry into meiosis in the mouse fetal ovary

NARCIS (Netherlands)

Chassot, Anne-Amandine; Gregoire, Elodie P.; Lavery, Rowena; Taketo, Makoto M.; de Rooij, Dirk G.; Adams, Ian R.; Chaboissier, Marie-Christine

2011-01-01

Differentiation of germ cells into male gonocytes or female oocytes is a central event in sexual reproduction. Proliferation and differentiation of fetal germ cells depend on the sex of the embryo. In male mouse embryos, germ cell proliferation is regulated by the RNA helicase Mouse Vasa homolog

RSPO1/beta-Catenin Signaling Pathway Regulates Oogonia Differentiation and Entry into Meiosis in the Mouse Fetal Ovary

NARCIS (Netherlands)

Chassot, A.A.; Gregoire, E.P.; Lavery, R.; Taketo, M.M.; de Rooij, D.G.; Adams, I.R.; Chaboissier, M.C.

2011-01-01

Differentiation of germ cells into male gonocytes or female oocytes is a central event in sexual reproduction. Proliferation and differentiation of fetal germ cells depend on the sex of the embryo. In male mouse embryos, germ cell proliferation is regulated by the RNA helicase Mouse Vasa homolog

The role of the kisspeptin system in regulation of the reproductive endocrine axis and territorial behavior in male side-blotched lizards (Uta stansburiana).

Science.gov (United States)

Neuman-Lee, Lorin; Greives, Timothy; Hopkins, Gareth R; French, Susannah S

2017-03-01

The neuropeptide kisspeptin and its receptor are essential for activation of the hypothalamic-pituitary-gonadal (HPG) axis and regulating reproduction. While the role of kisspeptin in regulating the HPG axis in mammals has been well established, little is known about the functional ability of kisspeptins to activate the HPG axis and associated behavior in non-mammalian species. Here we experimentally examined the effects of kisspeptin on downstream release of testosterone and associated aggression and display behaviors in the side-blotched lizard (Uta stansburiana). We found that exogenous treatment with kisspeptin resulted in an increase in circulating testosterone levels, castration blocked the kisspeptin-induced increase in testosterone, and testosterone levels in kisspeptin-treated animals were positively related to frequency of aggressive behaviors. This evidence provides a clear link between kisspeptin, testosterone, and aggressive behavior in lizards. Thus, it is likely that kisspeptin plays an important role more broadly in non-mammalian systems in the regulation of reproductive physiology and related behaviors. Copyright © 2016 Elsevier Inc. All rights reserved.

Chronobiology of reproduction in garter snakes: neuroendocrine mechanisms and geographic variation.

Science.gov (United States)

Lutterschmidt, Deborah I

2012-05-01

The majority of studies on reproductive neuroendocrinology in snakes have focused on one particular snake population in Manitoba, Canada, the red-sided garter snake (Thamnophis sirtalis parietalis). Although traditionally these studies have emphasized its unusual temporal dissociation between mating behavior and peak gonadal activity, current evidence suggests that reproductive regulation in this population may be more similar to the norm than previously thought. Like other ectotherms, temperature plays a critical role in activating reproductive behavior in red-sided garter snakes. Diel melatonin and corticosterone rhythms appear to be important in transducing temperature cues, and it is clear that both hormones regulate courtship behavior during spring. Current evidence also suggests that sex steroid hormones are in fact central to reproductive regulation in males, although the timing of their action occurs during winter dormancy. Whether this is also true for female T. sirtalis parietalis requires further study, but it should be noted that patterns of sex steroid hormones are sexually dimorphic during winter dormancy, as are melatonin rhythms during spring emergence. While continuing to advance our understanding of reproductive regulation in this extremely well-studied population is prudent, future comparative studies are critical for understanding if and how reproductive regulatory mechanisms differ across environments, populations, and phylogenies. For example, melatonin and corticosterone responses to environmental cues vary significantly among populations of T. sirtalis in a common garden, as do male courtship behavior and androgen concentrations. These data support the hypothesis that neuroendocrine-mediated responses to environmental cues underlie phenotypic plasticity in reproductive life history traits. Copyright © 2011 Elsevier Inc. All rights reserved.

Legal aspects of auxillary reproductive technologies in infertility treatment

OpenAIRE

V.Yu. Albitskiy; N.D. Odinayeva; V.O. Mansimova

2011-01-01

The article presents several aspects of legal regulation of auxillary reproductive technologies in treatment of infertility in Russia and other countries.Key words: auxillary reproductive technologies, method of extracorporeal fertilization, newborn, premature newborn, multiple pregnancy, embryo, infertility, law.

Role of neuropeptide Y (NPY) in the regulation of reproduction: study based on catfish model.

Science.gov (United States)

Subhedar, Nishikant; Gaikwad, Archana; Biju, K C; Saha, Subhash

2005-04-01

Significance of NPY in the regulation of GnRH-LH axis was evaluated. Considerable NPY immunoreactivity was seen in the components like olfactory system, basal telencephalon, preoptic and tuberal areas, and the pituitary gland that serve as neuroanatomical substrates for processing reproductive information. Close anatomical association as well as colocalizations of NPY and GnRH were seen in the olfactory receptor neurons, olfactory nerve fibers and their terminals in the glomeruli, ganglion cells of nervus terminalis, medial olfactory tracts, fibers in the ventral telencephalon and pituitary. In the pituitary, NPY fibers seem to innervate the GnRH as well as LH cells. Intracranial administration of NPY resulted in significant increase in the GnRH immunoreactivity in all the components of the olfactory system. In the pituitary, NPY augmented the population of GnRH fibers and LH cells. HPLC analysis showed that salmon GnRH content in the olfactory organ, bulb, preoptic area+telencephalon and pituitary was also significantly increased following NPY treatment. NPY may play a role in positive regulation of GnRH throughout the neuraxis and also up-regulate the LH cells in the pituitary.

Photoperiod- and Triiodothyronine-dependent Regulation of Reproductive Neuropeptides, Proinflammatory Cytokines, and Peripheral Physiology in Siberian Hamsters (Phodopus sungorus).

Science.gov (United States)

Banks, Ruth; Delibegovic, Mirela; Stevenson, Tyler J

2016-06-01

Seasonal trade-offs in reproduction and immunity are ubiquitous in nature. The mechanisms that govern transitions across seasonal physiological states appear to involve reciprocal switches in the local synthesis of thyroid hormone. In long-day (LD) summer-like conditions, increased hypothalamic triiodothyronine (T3) stimulates gonadal development. Alternatively, short-day (SD) winter-like conditions increase peripheral leukocytes and enhance multiple aspects of immune function. These data indicate that the localized effects of T3 in the hypothalamus and leukocytes are photoperiod dependent. We tested the hypothesis that increased peripheral T3 in SD conditions would increase aspects of reproductive physiology and inhibit immune function, whereas T3 injections in LD conditions would facilitate aspects of immune function (i.e., leukocytes). In addition, we also examined whether T3 regulates hypothalamic neuropeptide expression as well as hypothalamic and splenic proinflammatory cytokine expression. Adult male Siberian hamsters were maintained in LD (15L:9D) or transferred to SD (9L:15D) for 8 weeks. A subset of LD and SD hamsters was treated daily with 5 µg T3 for 2 weeks. LD and SD controls were injected with saline. Daily T3 administration in SD hamsters (SD+T3) resulted in a rapid and substantial decrease in peripheral leukocyte concentrations and stimulated gonadal development. T3 treatment in LD (LD+T3) had no effect on testicular volumes but significantly increased leukocyte concentrations. Molecular analyses revealed that T3 stimulated interleukin 1β messenger RNA (mRNA) expression in the spleen and inhibited RFamide Related Peptide-3 mRNA expression in the hypothalamus. Moreover, there was a photoperiod-dependent decrease in splenic tumor necrosis factor-α mRNA expression. These findings reveal that T3 has tissue-specific and photoperiod-dependent regulation of seasonal rhythms in reproduction and immune function. © 2016 The Author(s).

Canada's Assisted Human Reproductive Act: is it scientific censorship, or a reasoned approach to the regulation of rapidly emerging reproductive technologies?

Science.gov (United States)

Rasmussen, Colin

2004-01-01

After more than a decade of study, discussion and debate, the Canadian House of Commons and Senate have approved the Assisted Human Reproduction Act. Building on the earlier Bill C-47, which died on the order paper in 1997, the Act bans human cloning for reproductive or therapeutic purposes, payment for surrogacy arrangements, and trading in human reproductive materials or their use without informed consent. In addition, the Act significantly restricts research using human reproductive materials. This article compares the Act to legislative regimes in other nations with advanced human reproductive science. It concludes that while the Act has many laudable goals, it is flawed in that it tries to cover too much legislative ground. As a result it unreasonable impairs the ability of Canadian scientists to compete in areas such as stem cell research, and area that is expected to yield significant new approaches to treating human disease.

Broad support for regulating the clinical implementation of future reproductive techniques.

Science.gov (United States)

Hendriks, S; Vliegenthart, R; Repping, S; Dancet, E A F

2018-01-01

the disposal of human embryos. Regulation for out-of-pocket costs and the burden of treatment received little support. The majority of gynaecologists and the general public, but not the patients, requested regulation for the risk of minor congenital abnormalities, the success rates and the naturalness of treatments. Nevertheless, the majority of patients did consider the former two potential negative consequences important. The majority of all groups preferred a national bioethics committee as the regulatory body. This committee should consult with advisors from various backgrounds and should consider the broader context of potential consequences of the stem cell-based fertility treatments. This empirical study focuses on only three stakeholder groups. This study reports on the perspective of the majority and this is not per definition the morally right perspective. The transferability of our findings to other cultures and other techniques remains unclear. A national bioethics committee, consulting with advisors from various backgrounds, should regulate the clinical implementation of future stem cell-based fertility treatments. Whether this broad support for regulation applies to novel techniques from other fields of medicine should be examined. The Young Academy of the Royal Netherlands Academy of Arts and Sciences. None of the authors has any conflict of interest to declare. Not applicable. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Legal aspects of auxillary reproductive technologies in infertility treatment

Directory of Open Access Journals (Sweden)

V.Yu. Albitskiy

2011-01-01

Full Text Available The article presents several aspects of legal regulation of auxillary reproductive technologies in treatment of infertility in Russia and other countries.Key words: auxillary reproductive technologies, method of extracorporeal fertilization, newborn, premature newborn, multiple pregnancy, embryo, infertility, law.

Fathers' parenting, adverse life events, and adolescents' emotional and eating disorder symptoms: the role of emotion regulation.

Science.gov (United States)

McEwen, Ciara; Flouri, Eirini

2009-04-01

To investigate the role of emotion regulation in the relation between fathers' parenting (specifically warmth, behavioral control and psychological control) and adolescents' emotional and eating disorder symptoms, after adjustment for controls. A total of 203 11-18 year-old students from a school in a socio-economically disadvantaged area in North-East London completed questionnaires assessing emotional symptoms (measured with the Strengths and Difficulties Questionnaire's (SDQ) Emotional Symptoms Scale), eating disorder symptoms (measured with the Eating Attitudes Test (EAT-26)), difficulties in emotion regulation (measured with the Difficulties in Emotion Regulation Scale (DERS)), and fathers' overprotection and warmth, measured with the Parental Bonding Instrument (PBI), as well as behavioral and psychological control. The confounding variables considered were number of proximal (i.e., during the last year) adverse life events experienced, gender, age, and socio-economic status (eligibility for free school meals). Adolescents' difficulties in emotion regulation mediated the link between fathers' psychological control and adolescents' emotional symptoms, but not the link between fathers' parenting and adolescents' eating disorder symptoms, which appeared to be more directly linked to fathers' psychological control and number of proximal adverse life events experienced. Proximal adverse life events experienced were also strongly associated with difficulties in emotion regulation. The study findings have implications for intervention programs which may prove more fruitful in addressing adolescent emotional problems by targeting underlying emotion regulation abilities, and in addressing adolescent eating disorder symptoms by protecting adolescents with a recent experience of multiple adverse life events. Parenting programs also stand to benefit from the evidence presented in this study that paternal psychological control may have uniquely harmful consequences for

75 FR 29889 - Special Local Regulation for Marine Event; 2010 International Cup Regatta, Pasquotank River...

Science.gov (United States)

2010-05-28

...-AA08 Special Local Regulation for Marine Event; 2010 International Cup Regatta, Pasquotank River... traffic in a portion of the Pasquotank River, near Elizabeth City, NC, during the 2010 International Cup... event in 33 CFR 100.501 and 33 CFR Table to Sec. 100.501, No. 54. On June 5 and 6, 2010, Carolina Cup...

REPRODUCTIVE SEASONALITY OF SHEEP IN MEXICO

Directory of Open Access Journals (Sweden)

Jaime Arroyo

2011-07-01

Full Text Available In order to discuss and analyze the available information concerning the seasonal breeding behavior of sheep in Mexico, this review was conducted. We analyzed the neuroendocrine basis that modulate the annual reproductive cycle in sheep and then discussed the degree of reproductive seasonality in Creole sheep wool, breeds originating in high latitudes and hair sheep, mainly in Pelibuey ewes. The Creole sheep wool show continuous annual reproductive activity and short seasonal anestrous. The females of northern origin, express seasonal reproductive activity, similar to that observed in individuals geographically located at latitudes above 35º. Pelibuey sheep show variable annual reproductive behavior with reduced anestrus or lack thereof.  It is suggested that the neuroendocrine mechanisms regulating seasonal anestrus in ewes, are active in the sheep of northern origin that live in Mexico, in a manner contrary is not activated in Creole and hair sheep.

Gonadotropin Inhibitory Hormone Down-Regulates the Brain-Pituitary Reproductive Axis of Male European Sea Bass (Dicentrarchus labrax).

Science.gov (United States)

Paullada-Salmerón, José A; Cowan, Mairi; Aliaga-Guerrero, María; Morano, Francesca; Zanuy, Silvia; Muñoz-Cueto, José A

2016-06-01

Gonadotropin-inhibitory hormone (GnIH) inhibits gonadotropin synthesis and release from the pituitary of birds and mammals. However, the physiological role of orthologous GnIH peptides on the reproductive axis of fish is still uncertain, and their actions on the main neuroendocrine systems controlling reproduction (i.e., GnRHs, kisspeptins) have received little attention. In a recent study performed in the European sea bass, we cloned a cDNA encoding a precursor polypeptide that contained C-terminal MPMRFamide (sbGnIH-1) and MPQRFamide (sbGnIH-2) peptide sequences, developed a specific antiserum against sbGnIH-2, and characterized its central and pituitary GnIH projections in this species. In this study, we analyzed the effects of intracerebroventricular injection of sbGnIH-1 and sbGnIH-2 on brain and pituitary expression of reproductive hormone genes (gnrh1, gnrh2, gnrh3, kiss1, kiss2, gnih, lhbeta, fshbeta), and their receptors (gnrhr II-1a, gnrhr II-2b, kiss1r, kiss2r, and gnihr) as well as on plasma Fsh and Lh levels. In addition, we determined the effects of GnIH on pituitary somatotropin (Gh) expression. The results obtained revealed the inhibitory role of sbGnIH-2 on brain gnrh2, kiss1, kiss2, kiss1r, gnih, and gnihr transcripts and on pituitary fshbeta, lhbeta, gh, and gnrhr-II-1a expression, whereas sbGnIH-1 only down-regulated brain gnrh1 expression. However, at different doses, central administration of both sbGnIH-1 and sbGnIH-2 decreased Lh plasma levels. Our work represents the first study reporting the effects of centrally administered GnIH in fish and provides evidence of the differential actions of sbGnIH-1 and sbGnIH-2 on the reproductive axis of sea bass, the main inhibitory role being exerted by the sbGnIH-2 peptide. © 2016 by the Society for the Study of Reproduction, Inc.

[Difference between perinatal mortality in multiple pregnancies obtained spontaneously versus assisted reproduction].

Science.gov (United States)

del Rayo Rivas-Ortiz, Yazmín; Hernández-Herrera, Ricardo Jorge

2010-06-01

Recently assisted reproduction techniques are more common, which increases multiple pregnancies and adverse perinatal outcomes. Some authors report increased mortality in multiple pregnancies products obtained by techniques of assisted reproduction vs. conceived spontaneously, although other authors found no significant difference. To evaluate mortality rate of multiple pregnancies comparing those obtained by assisted reproduction vs. spontaneous conception. Retrospective, observational and comparative study. We included pregnant women with 3 or more products that went to the Unidad Médica de Alta Especialidad No. 23, IMSS, in Monterrey, NL (Mexico), between 2002-2008. We compared the number of complicated pregnancies and dead products obtained by a technique of assisted reproduction vs. spontaneous. 68 multiple pregnancies were included. On average, spontaneously conceived fetuses had more weeks of gestation and more birth weight than those achieved by assisted reproduction techniques (p = ns). 20.5% (14/68) of multiple pregnancies had one or more fatal events: 10/40 (25%) by assisted reproduction techniques vs. 4/28 (14%) of spontaneous multiple pregnancies (p = 0.22). 21/134 (16%) of the products conceived by assisted reproduction techniques and 6/88 (7%) of spontaneous (p assisted reproduction and 21% of the cases had one or more fatal events (11% more in pregnancies achieved by assisted reproduction techniques). 12% of the products of multiple pregnancies died (9% more in those obtained by a technique of assisted reproduction).

19 CFR 122.5 - Reproduction of Customs forms.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Reproduction of Customs forms. 122.5 Section 122.5 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS General Definitions and Provisions § 122.5 Reproduction of Customs forms...

Reproductive Health Services Discrete-Event Simulation

OpenAIRE

Lee, Sungjoo; Giles, Denise F.; Goldsman, David; Cook, Douglas A.; Mishra, Ninad; McCarthy, Brian

2006-01-01

Low resource healthcare environments are often characteristic of patient flow patterns with varying patient risks, extensive patient waiting times, uneven workload distributions, and inefficient service delivery. Models from industrial and systems engineering allow for a greater examination of processes by applying discrete-event computer simulation techniques to evaluate and optimize hospital performance.

Fetal programming of sexual development and reproductive function.

Science.gov (United States)

Zambrano, Elena; Guzmán, Carolina; Rodríguez-González, Guadalupe L; Durand-Carbajal, Marta; Nathanielsz, Peter W

2014-01-25

The recent growth of interest in developmental programming of physiological systems has generally focused on the cardiovascular system (especially hypertension) and predisposition to metabolic dysfunction (mainly obesity and diabetes). However, it is now clear that the full range of altered offspring phenotypes includes impaired reproductive function. In rats, sheep and nonhuman primates, reproductive capacity is altered by challenges experienced during critical periods of development. This review will examine available experimental evidence across commonly studied experimental species for developmental programming of female and male reproductive function throughout an individual's life-course. It is necessary to consider events that occur during fetal development, early neonatal life and prior to and during puberty, during active reproductive life and aging as reproductive performance declines. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Comparative analysis reveals the underlying mechanism of vertebrate seasonal reproduction.

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Ikegami, Keisuke; Yoshimura, Takashi

2016-02-01

Animals utilize photoperiodic changes as a calendar to regulate seasonal reproduction. Birds have highly sophisticated photoperiodic mechanisms and functional genomics analysis in quail uncovered the signal transduction pathway regulating avian seasonal reproduction. Birds detect light with deep brain photoreceptors. Long day (LD) stimulus induces secretion of thyroid-stimulating hormone (TSH) from the pars tuberalis (PT) of the pituitary gland. PT-derived TSH locally activates thyroid hormone (TH) in the hypothalamus, which induces gonadotropin-releasing hormone (GnRH) and hence gonadotropin secretion. However, during winter, low temperatures increase serum TH for adaptive thermogenesis, which accelerates germ cell apoptosis by activating the genes involved in metamorphosis. Therefore, TH has a dual role in the regulation of seasonal reproduction. Studies using TSH receptor knockout mice confirmed the involvement of PT-derived TSH in mammalian seasonal reproduction. In addition, studies in mice revealed that the tissue-specific glycosylation of TSH diversifies its function in the circulation to avoid crosstalk. In contrast to birds and mammals, one of the molecular machineries necessary for the seasonal reproduction of fish are localized in the saccus vasculosus from the photoreceptor to the neuroendocrine output. Thus, comparative analysis is a powerful tool to uncover the universality and diversity of fundamental properties in various organisms. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Learning from Cross-Border Reproduction

Science.gov (United States)

Millbank, Jenni; Karpin, Isabel; Stuhmcke, Anita

2017-01-01

Abstract Drawing upon the preliminary findings of an Australian empirical project on cross-border reproduction (CBR), this article argues that regulators and policymakers could learn from the experiences of those who travel overseas in order to access fertility treatment and surrogacy. It makes four principal observations. First, the distinction between so-called ‘altruistic’ and ‘commercial’ gamete donation and surrogacy is increasingly unsustainable and is not experienced as meaningful by many participants in CBR. Secondly, the status of the law in CBR is profoundly equivocal; for participants it is often there and not there at the same time. Thirdly, self-sourced information, from the internet and more specifically social media such as Facebook, is now the principal source of information and peer support for reproductive travellers. Fourthly, and relatedly, domestic reproductive services providers are often sidestepped. If one of the goals of regulation is to minimise the risk of harm to participants, it is not clear that it is currently achieving this aim, and this article argues that any reforms will only work if they are more responsive to the reality of CBR. PMID:28073821

Learning from Cross-Border Reproduction.

Science.gov (United States)

Jackson, Emily; Millbank, Jenni; Karpin, Isabel; Stuhmcke, Anita

2017-02-01

Drawing upon the preliminary findings of an Australian empirical project on cross-border reproduction (CBR), this article argues that regulators and policymakers could learn from the experiences of those who travel overseas in order to access fertility treatment and surrogacy. It makes four principal observations. First, the distinction between so-called 'altruistic' and 'commercial' gamete donation and surrogacy is increasingly unsustainable and is not experienced as meaningful by many participants in CBR. Secondly, the status of the law in CBR is profoundly equivocal; for participants it is often there and not there at the same time. Thirdly, self-sourced information, from the internet and more specifically social media such as Facebook, is now the principal source of information and peer support for reproductive travellers. Fourthly, and relatedly, domestic reproductive services providers are often sidestepped. If one of the goals of regulation is to minimise the risk of harm to participants, it is not clear that it is currently achieving this aim, and this article argues that any reforms will only work if they are more responsive to the reality of CBR. © The Author 2017. Published by Oxford University Press.

Integrative Control of Energy Balance and Reproduction in Females

OpenAIRE

Garcia-Garcia, R. M.

2012-01-01

There is a strong association between nutrition and reproduction. Chronic dietary energy deficits as well as energy surpluses can impair reproductive capacity. Metabolic status impacts reproductive function at systemic level, modulating the hypothalamic GnRH neuronal network and/or the pituitary gonadotropin secretion through several hormones and neuropeptides, and at the ovarian level, acting through the regulation of follicle growth and steroidogenesis by means of the growth hormone-IGF-ins...

The delayed reproduction of long time intervals defined by innocuous thermal sensation.

Science.gov (United States)

Khoshnejad, Mina; Martinu, Kristina; Grondin, Simon; Rainville, Pierre

2016-04-01

The presence of discrete events during an interval to be estimated generally causes a dilation of perceived duration (event-filling effect). Here, we investigated this phenomenon in the thermal modality using multi-seconds (19 s) innocuous cool stimuli that were either constant (continuous interval) or fluctuating to create three discrete sensory events (segmented interval). Moreover, we introduced a delay following stimulus offset, before the reproduction phase, to allow for a direct comparison with our recent study showing an underestimation of duration in a delayed reproduction task of heat pain sensations (Khoshnejad et al. in Pain 155:581-590, 2014. doi: 10.1016/j.pain.2013.12.015 ). The event-filling effect was tested by comparing the delayed reproduction of the segmented and the continuous stimuli in experimental conditions asking participants to (1) reproduce the dynamics of the sensation (i.e., changes in sensory intensity over time) or (2) reproduce only the interval duration (i.e., sensation onset-to-offset). A perceptual (control) condition required participants to report changes in sensation concurrently with the stimulus. Results of the dynamic task confirmed the underestimation of duration in the delayed reproduction task, but this effect was only found with the continuous and not with the segmented stimulus. This implies that the dilation of duration produced by segmentation might compensate for the underestimation of duration in this delayed reproduction task. However, this temporal dilation effect was only observed when participants were required to attend and reproduce the dynamics of sensation. These results suggest that the event-filling effect can be observed in the thermal sensory modality and that attention directed toward changes in sensory intensity might contribute to this effect.

49 CFR 390.35 - Certificates, reports, and records: Falsification, reproduction, or alteration.

Science.gov (United States)

2010-10-01

..., reproduction, or alteration. 390.35 Section 390.35 Transportation Other Regulations Relating to Transportation... § 390.35 Certificates, reports, and records: Falsification, reproduction, or alteration. No motor... requirement of this subchapter or part 325 of subchapter A; or (c) A reproduction, for fraudulent purposes, of...

Physical activity and its effects on reproduction.

Science.gov (United States)

Redman, Leanne M

2006-05-01

The reproductive system is tightly coupled with energy balance, and thereby changes in the status of energy balance through changes in physical activity can impact on the reproductive system. In light of the new physical activity for health recommendations, it is therefore important to understand the inherent effects, both positive and negative, of physical activity on the reproductive system. At both extremes of the energy spectrum, disorders of chronic energy excess and energy deficiency are characterized by a wide range of reproductive disorders, including menstrual irregularity, anovulation, polycystic ovarian syndrome, and infertility in women, and erectile dysfunction and altered spermatogenesis in men. Although laboratory research indicates that individuals may be able to prevent or reverse reproductive disruptions, either by increasing energy expenditure in cases of energy excess or by dietary reform in cases of energy deficits, there is an acute need for applied research to confirm this idea and to identify mechanisms by which the availability of energy per se regulates reproductive function in humans.

Marijuana, the Endocannabinoid System and the Female Reproductive System.

Science.gov (United States)

Brents, Lisa K

2016-06-01

Marijuana use among women is highly prevalent, but the societal conversation on marijuana rarely focuses on how marijuana affects female reproduction and endocrinology. This article reviews the current scientific literature regarding marijuana use and hypothalamic-pituitary-ovarian (HPO) axis regulation, ovarian hormone production, the menstrual cycle, and fertility. Evidence suggests that marijuana can reduce female fertility by disrupting hypothalamic release of gonadotropin releasing hormone (GnRH), leading to reduced estrogen and progesterone production and anovulatory menstrual cycles. Tolerance to these effects has been shown in rhesus monkeys, but the effects of chronic marijuana use on human female reproduction are largely unknown. Marijuana-induced analgesia, drug reinforcement properties, tolerance, and dependence are influenced by ovarian hormones, with estrogen generally increasing and progesterone decreasing sensitivity to marijuana. Carefully controlled regulation of the Endocannabinoid System (ECS) is required for successful reproduction, and the exogenous cannabinoids in marijuana may disrupt the delicate balance of the ECS in the female reproductive system.

75 FR 10195 - Special Local Regulations for Marine Events; Chester River, Chestertown, MD

Science.gov (United States)

2010-03-05

... event from outside the regulated area, but may not block the navigable channel. Other vessels intending... their plans accordingly. If you think that your business, organization, or governmental jurisdiction... a comment (see ADDRESSES) explaining why you think it qualifies and how and to what degree this rule...

Ethics and regulation of inter-country medically assisted reproduction: a call for action

OpenAIRE

Shalev, Carmel; Moreno, Adi; Eyal, Hedva; Leibel, Michal; Schuz, Rhona; Eldar-Geva, Talia

2016-01-01

The proliferation of medically assisted reproduction (MAR) for the treatment of infertility has brought benefit to many individuals around the world. But infertility and its treatment continue to be a cause of suffering, and over the past decade, there has been a steady growth in a new global market of inter-country medically assisted reproduction (IMAR) involving ?third-party? individuals acting as surrogate mothers and gamete donors in reproductive collaborations for the benefit of other in...

Gap junction connexins in female reproductive organs: implications for women's reproductive health.

Science.gov (United States)

Winterhager, Elke; Kidder, Gerald M

2015-01-01

Connexins comprise a family of ~20 proteins that form intercellular membrane channels (gap junction channels) providing a direct route for metabolites and signalling molecules to pass between cells. This review provides a critical analysis of the evidence for essential roles of individual connexins in female reproductive function, highlighting implications for women's reproductive health. No systematic review has been carried out. Published literature from the past 35 years was surveyed for research related to connexin involvement in development and function of the female reproductive system. Because of the demonstrated utility of genetic manipulation for elucidating connexin functions in various organs, much of the cited information comes from research with genetically modified mice. In some cases, a distinction is drawn between connexin functions clearly related to the formation of gap junction channels and those possibly linked to non-channel roles. Based on work with mice, several connexins are known to be required for female reproductive functions. Loss of connexin43 (CX43) causes an oocyte deficiency, and follicles lacking or expressing less CX43 in granulosa cells exhibit reduced growth, impairing fertility. CX43 is also expressed in human cumulus cells and, in the context of IVF, has been correlated with pregnancy outcome, suggesting that this connexin may be a determinant of oocyte and embryo quality in women. Loss of CX37, which exclusively connects oocytes with granulosa cells in the mouse, caused oocytes to cease growing without acquiring meiotic competence. Blocking of CX26 channels in the uterine epithelium disrupted implantation whereas loss or reduction of CX43 expression in the uterine stroma impaired decidualization and vascularization in mouse and human. Several connexins are important in placentation and, in the human, CX43 is a key regulator of the fusogenic pathway from the cytotrophoblast to the syncytiotrophoblast, ensuring placental growth

Emerging issues and methodological advances in fisheries reproductive biology

DEFF Research Database (Denmark)

Lowerre-Barbieri, Susan K.; Brown-Peterson, Nancy J.; Murua, Hilario

2011-01-01

Although incorporating detailed reproductive data into all stock assessments is not a practical goal, the need to understand how reproductive biology affects population productivity is being increasingly recognized.More research focused on reproductive biology—coupled with a shift towards...... a resilience perspective in fisheries science—is resulting in challenges to many long-held assumptions; the emergence of important new issues; and identification of the need to improve data and methods used in reproductive studies. Typically, data for reproductive studies are based on an assessment of gonadal...... while introducing improved and new histological techniques. In this introduction, we address the following needs: (1) to employ standardization, thereby improving our ability to conduct comparative studies; (2) to better understand patterns of gonadal development and spawning events over time; and (3...

78 FR 36424 - Special Local Regulations for Summer Events; Captain of the Port Lake Michigan Zone

Science.gov (United States)

2013-06-18

... mentioned in this preamble as being available in the docket, go to http://www.regulations.gov , type the... waters of Horseshoe Bay--a portion of Green Bay. As this event is currently listed within 33 CFR 100.905... regulations on small entities during rulemaking. The term ``small entities'' comprises small businesses, not...

75 FR 41373 - Special Local Regulations for Marine Events; Port Huron to Mackinac Island Sail Race

Science.gov (United States)

2010-07-16

...-AA08 Special Local Regulations for Marine Events; Port Huron to Mackinac Island Sail Race AGENCY: Coast... regulation for the annual Port Huron to Mackinac Island Sail Race. This action is necessary to safely control... the Port Sector Detroit has determined that the start of the Port Huron to Mackinac Island Sail Race...

Sexual but not reproductive: exploring the junction and disjunction of sexual and reproductive rights.

Science.gov (United States)

Miller, A M

2000-01-01

Although the term "sexual rights" has gained widespread currency, its concrete scope and content have not yet been fully defined. The need for definition is critical not only for promoting governmental accountability but also for ensuring that sexual rights can be claimed by diverse persons around the world. Ironically, the concept of "sexual and reproductive rights" poses a challenge to this effort; practices and people not traditionally addressed by reproductive rights work must be explicitly named and protected. This article considers how international norms have contributed to a gendered regulation of sexuality and of contemporary theories of "socially constructed sexuality," and it proposes a focus on the conditions that contribute to the ability to choose and on the links between sexuality, conduct, identity, social structures, and reproduction. Given the probable politically charged responses, global coalition-building is needed.

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.

Cryptococcus neoformans sexual reproduction is controlled by a quorum sensing peptide.

Science.gov (United States)

Tian, Xiuyun; He, Guang-Jun; Hu, Pengjie; Chen, Lei; Tao, Changyu; Cui, Ying-Lu; Shen, Lan; Ke, Weixin; Xu, Haijiao; Zhao, Youbao; Xu, Qijiang; Bai, Fengyan; Wu, Bian; Yang, Ence; Lin, Xiaorong; Wang, Linqi

2018-06-01

Bacterial quorum sensing is a well-characterized communication system that governs a large variety of collective behaviours. By comparison, quorum sensing regulation in eukaryotic microbes remains poorly understood, especially its functional role in eukaryote-specific behaviours, such as sexual reproduction. Cryptococcus neoformans is a prevalent fungal pathogen that has two defined sexual cycles (bisexual and unisexual) and is a model organism for studying sexual reproduction in fungi. Here, we show that the quorum sensing peptide Qsp1 serves as an important signalling molecule for both forms of sexual reproduction. Qsp1 orchestrates various differentiation and molecular processes, including meiosis, the hallmark of sexual reproduction. It activates bisexual mating, at least in part through the control of pheromone, a signal necessary for bisexual activation. Notably, Qsp1 also plays a major role in the intercellular regulation of unisexual initiation and coordination, in which pheromone is not strictly required. Through a multi-layered genetic screening approach, we identified the atypical zinc finger regulator Cqs2 as an important component of the Qsp1 signalling cascade during both bisexual and unisexual reproduction. The absence of Cqs2 eliminates the Qsp1-stimulated mating response. Together, these findings extend the range of behaviours governed by quorum sensing to sexual development and meiosis.

Paralogous SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes differentially regulate leaf initiation and reproductive phase change in petunia.

Science.gov (United States)

Preston, Jill C; Jorgensen, Stacy A; Orozco, Rebecca; Hileman, Lena C

2016-02-01

Duplicated petunia clade-VI SPL genes differentially promote the timing of inflorescence and flower development, and leaf initiation rate. The timing of plant reproduction relative to favorable environmental conditions is a critical component of plant fitness, and is often associated with variation in plant architecture and habit. Recent studies have shown that overexpression of the microRNA miR156 in distantly related annual species results in plants with perennial characteristics, including late flowering, weak apical dominance, and abundant leaf production. These phenotypes are largely mediated through the negative regulation of a subset of genes belonging to the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) family of transcription factors. In order to determine how and to what extent paralogous SPL genes have partitioned their roles in plant growth and development, we functionally characterized petunia clade-VI SPL genes under different environmental conditions. Our results demonstrate that PhSBP1and PhSBP2 differentially promote discrete stages of the reproductive transition, and that PhSBP1, and possibly PhCNR, accelerates leaf initiation rate. In contrast to the closest homologs in annual Arabidopsis thaliana and Mimulus guttatus, PhSBP1 and PhSBP2 transcription is not mediated by the gibberellic acid pathway, but is positively correlated with photoperiod and developmental age. The developmental functions of clade-VI SPL genes have, thus, evolved following both gene duplication and speciation within the core eudicots, likely through differential regulation and incomplete sub-functionalization.

76 FR 35802 - Special Local Regulations for Marine Events; Patuxent River, Solomons, MD

Science.gov (United States)

2011-06-20

..., longitude 076[deg]28'22'' W. Spectator vessels viewing the event outside the regulated area may not block... will issue maritime advisories so mariners can adjust their plans accordingly. If you think that your... think it qualifies and how and to what degree this rule would economically affect it. Assistance for...

A critical role of the nuclear receptor HR3 in regulation of gonadotrophic cycles of the mosquito Aedes aegypti.

Directory of Open Access Journals (Sweden)

Daniel Mane-Padros

Full Text Available The orphan nuclear receptor HR3 is essential for developmental switches during insect development and metamorphosis regulated by 20-hydroxyecdysone (20E. Reproduction of female mosquitoes of the major vector of Dengue fever, Aedes aegypti, is cyclic because of its dependence on blood feeding. 20E is an important hormone regulating vitellogenic events in this mosquito; however, any role for HR3 in 20E-driven reproductive events has not been known. Using RNA interference (RNAi approach, we demonstrated that Aedes HR3 plays a critical role in a timely termination of expression of the vitellogenin (Vg gene encoding the major yolk protein precursor. It is also important for downregulation of the Target-of-Rapamycin pathway and activation of programmed autophagy in the Aedes fat body at the end of vitellogenesis. HR3 is critical in activating betaFTZ-F1, EcRB and USPA, the expressions of which are highly elevated at the end of vitellogenesis. RNAi depletion of HR3 (iHR3 prior to the first gonadotrophic cycle affects a normal progression of the second gonadotrophic cycle. Most of ovaries 24 h post second blood meal from iHR3 females in the second cycle were small with follicles that were only slightly different in length from of those of resting stage. In addition, these iHR3 females laid a significantly reduced number of eggs per mosquito as compared to those of iMal and the wild type. Our results indicate an important role of HR3 in regulation of 20E-regulated developmental switches during reproductive cycles of A. aegypti females.

Handling the Misalignment of Interests in Assisted Reproductive Technology Practices

OpenAIRE

Pierson, Anne

2010-01-01

One of the major problems we see in the use of reproductive technology at this time is that there is very little regulation of embryo transfer practices that lead to multigestational pregnancies. While the FDA must approve assisted reproductive technology (ART) devices and drugs that stimulate ovulation, it has no jurisdiction over the practice of medicine, how these drugs and devices are used on the ground, often in off-label procedures. The only current regulation of these practices is at...

Estrogens regulate the expression of NHERF1 in normal colon during the reproductive cycle of Wistar rats.

Science.gov (United States)

Cuello-Carrión, F Darío; Troncoso, Mariana; Guiñazu, Elina; Valdez, Susana R; Fanelli, Mariel A; Ciocca, Daniel R; Kreimann, Erica L

2010-12-01

In breast cancer cell lines, the Na(+)/H(+) exchanger regulator factor 1 (NHERF1) gene is regulated at the transcriptional level by estrogens, the protein expression levels correlate with the presence of estrogen receptors and the effect is blocked by anti-estrogens. However, there is limited information regarding the regulation of NHERF1 by estrogens in normal colon tissue. The NHERF1 protein has an important role in the maintenance of the intestine ultrastructure. NHERF1-deficient mice showed defects in the intestinal microvilli as well as molecular alterations in brush border membrane proteins. Here, we have studied the expression of NHERF1 in normal rat colon and uterus during the reproductive cycle of Wistar rats. We found that NHERF1 expression in rat colon during the estral cycle is modified by estrogen levels: higher expression of NHERF1 was observed during the proestrous and estrous stages and lower expression in diestrous 1 when estrogen levels decreased. In uterus, NHERF1 was expressed in the apical region of the luminal epithelium and glands in all stages of the estral cycle, and in both colon and uterus, the expression was independent of the proliferation status. Our results show that NHERF1 expression is regulated by estrogens in colon during the rat estral cycle.

Effect of tree logging on reproductive performance in Blue Tits (Cyanistes caeruleus)

NARCIS (Netherlands)

Amininasab, Seyed Mehdi; Xu, Charles C. Y.; Kingma, Sjouke A.; Komdeur, Jan

For birds, habitat quality is largely determined by local vegetation, and reproductive performance can therefore be negatively influenced by anthropogenic activities. A tree logging event enabled us to examine the effect of removing trees of different maturities and types on the reproductive

Adipokines and the Female Reproductive Tract

Directory of Open Access Journals (Sweden)

Maxime Reverchon

2014-01-01

Full Text Available It is well known that adipose tissue can influence puberty, sexual maturation, and fertility in different species. Adipose tissue secretes molecules called adipokines which most likely have an endocrine effect on reproductive function. It has been revealed over the last few years that adipokines are functionally implicated at all levels of the reproductive axis including the gonad and hypothalamic-pituitary axis. Many studies have shown the presence and the role of the adipokines and their receptors in the female reproductive tract of different species. These adipokines regulate ovarian steroidogenesis, oocyte maturation, and embryo development. They are also present in the uterus and placenta where they could create a favorable environment for embryonic implantation and play a key role in maternal-fetal metabolism communication and gestation. Reproductive functions are strongly dependent on energy balance, and thereby metabolic abnormalities can lead to the development of some pathophysiologies such as polycystic ovary syndrome (PCOS. Adipokines could be a link between reproduction and energy metabolism and could partly explain some infertility related to obesity or PCOS.

76 FR 15244 - Special Local Regulations for Marine Events; Chester River, Chestertown, MD

Science.gov (United States)

2011-03-21

.... Spectator vessels will be allowed to view the event from outside the regulated area, but may not block the... mariners can adjust their plans accordingly. If you think that your business, organization, or governmental..., please submit a comment (see ADDRESSES) explaining why you think it qualifies and how and to what degree...

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.

78 FR 54571 - Special Local Regulation for Marine Event Hampton Bay Days Festival, Hampton River; Hampton, VA

Science.gov (United States)

2013-09-05

...-AA08 Special Local Regulation for Marine Event Hampton Bay Days Festival, Hampton River; Hampton, VA... Fifth Coast Guard District. This regulation applies only to the Hampton Bay Days Festival, which... Purpose Hampton Bay Days is sponsoring the three days Hampton Bay Days Festival, which includes a...

The devil we know: the implications of bill C-38 for assisted human reproduction in Canada.

Science.gov (United States)

Cattapan, Alana; Cohen, Sara R

2013-07-01

In June 2012, the Canadian House of Commons passed the so-called omnibus budget bill, making several important changes to the governance of assisted reproduction in Canada. The bill (Bill C-38) was widely criticized for its unwieldy size and rapid passage through Parliament, preventing adequate parliamentary debate and public scrutiny. Given the substantive nature of the amendments to the Assisted Human Reproduction Act made by Bill C-38, and the lack of relevant discussion about these changes both before and following its passage, this commentary is intended to identify how Bill C-38 may alter the governance of reproductive technologies in Canada. In this commentary, we address some of the more significant changes made by Bill C-38 to the regulation of reproductive medicine in Canada. We identify the benefits and challenges of closing Assisted Human Reproduction Canada, noting that doing so eliminates a much-needed forum for stakeholder consultation in this field. Further, we explore the implications of moving the regulation of donor semen from the Food and Drugs Act to the Assisted Human Reproduction Act; these include increased liability for physicians, and opportunities to expand the existing regulations to account for the needs of lesbian, gay, bisexual, trans, and queer Canadians using donor gametes and recent advances in reproductive technologies. Overall, we argue that although the implementation of a policy framework in this field remains highly dependent on yet-to-be written regulations, the changes to the Assisted Human Reproduction Act enabled by Bill C-38 may significantly alter how Canadians interact with reproductive technologies.

Neonatal outcome following new assisted reproductive technology regulations in Turkey - a nationwide multicenter point prevalence study.

Science.gov (United States)

Kultursay, Nilgun; Yalaz, Mehmet; Koroglu, Ozge Altun

2015-01-01

In March 2010, a new legislation about assisted reproductive technology (ART) activities, favoring single embryo transfer, was introduced in Turkey. Consequences of new regulations on neonatal outcome have not been evaluated in multicenter studies yet. In this study, our aim was to evaluate neonatal outcome of infants from medically assisted reproduction (MAR) pregnancies in the post-legislation era. A point prevalence study was conducted at 51 centers in Turkey on 1 April 2013. Data about fertility treatments and neonatal characteristics were evaluated for "live births" (Group 1) and "patients being cared in the NICU" (Group 2). Seventeen (4%) of 420 infants in group 1, and 89 (8.1%) of 1094 infants in group 2 were born after MAR pregnancies. The ratio of multiple births in MAR pregnancies was still very high as 47.1% for group 1, 69.1% for group 2 infants. MAR babies constituted 9.9% of infants in Level 3 NICUs and 7.6% infants in Level 2 NICUs. MAR was associated with increased risk of multiple births and prematurity. After the new legislation, multiple birth rates are still high in MAR pregnancies, resulting in unfavorable neonatal outcomes. Efforts to decrease multiple birth rates should be encouraged.

Reproductive science as an essential component of conservation biology.

Science.gov (United States)

Holt, William V; Brown, Janine L; Comizzoli, Pierre

2014-01-01

In this chapter we argue that reproductive science in its broadest sense has never been more important in terms of its value to conservation biology, which itself is a synthetic and multidisciplinary topic. Over recent years the place of reproductive science in wildlife conservation has developed massively across a wide and integrated range of cutting edge topics. We now have unprecedented insight into the way that environmental change affects basic reproductive functions such as ovulation, sperm production, pregnancy and embryo development through previously unsuspected influences such as epigenetic modulation of the genome. Environmental change in its broadest sense alters the quality of foodstuffs that all animals need for reproductive success, changes the synchrony between breeding seasons and reproductive events, perturbs gonadal and embryo development through the presence of pollutants in the environment and drives species to adapt their behaviour and phenotype. In this book we explore many aspects of reproductive science and present wide ranging and up to date accounts of the scientific and technological advances that are currently enabling reproductive science to support conservation biology.

75 FR 47215 - Special Local Regulation; Marine Events Within the Captain of the Port Sector Boston Zone

Science.gov (United States)

2010-08-05

... special local regulations on: (1) The Charles River between the Longfellow Bridge and the Harvard Bridge... local regulations are established for the following marine events: (1) Charles River One Mile Swim, Charles River, Boston, MA. (i) Location. All waters of the Charles River, from surface to bottom, between...

Normal development of the female reproductive system

Science.gov (United States)

The embryonic development of the female reproductive system involves a progression of events that is conserved across vertebrate species. The early gonad progresses from a form that is undifferentiated in both genotypic males and females. Rudimentary male (Wolffian) and female (M...

75 FR 30296 - Special Local Regulation for Marine Event; Maryland Swim for Life, Chester River, Chestertown, MD

Science.gov (United States)

2010-06-01

... safety of life on navigable waters during the event. DATES: This rule is effective from 5:30 a.m. to 2:30...-AA08 Special Local Regulation for Marine Event; Maryland Swim for Life, Chester River, Chestertown, MD AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is temporarily changing...

Leptin and reproduction: a review.

Science.gov (United States)

Moschos, Stergios; Chan, Jean L; Mantzoros, Christos S

2002-03-01

To review recent advances in understanding the role of leptin in the physiology and pathophysiology of reproduction, with a focus on relevant clinical situations. A MEDLINE computer search was performed to identify relevant articles. Leptin, an adipocyte hormone important in regulating energy homeostasis, interacts with the reproductive axis at multiple sites, with stimulatory effects at the hypothalamus and pituitary and inhibitory actions at the gonads. More recently, leptin has been shown to play a role in other target reproductive organs, such as the endometrium, placenta, and mammary gland, with corresponding influences on important physiologic processes such as menstruation, pregnancy, and lactation. As a marker of whether nutritional stores are adequate, leptin may act in concert with gonadotropins and the growth hormone axis to initiate the complex process of puberty. Conditions in which nutritional status is suboptimal, such as eating disorders, exercise-induced amenorrhea, and functional hypothalamic amenorrhea, are associated with low serum leptin levels; and conditions with excess energy stores or metabolic disturbances, such as obesity and polycystic ovarian syndrome, often have elevated serum or follicular fluid leptin levels, raising the possibility that relative leptin deficiency or resistance may be at least partly responsible for the reproductive abnormalities that occur with these conditions. Leptin may act as the critical link between adipose tissue and the reproductive system, indicating whether adequate energy reserves are present for normal reproductive function. Future interventional studies involving leptin administration are expected to further clarify this role of leptin and may provide new therapeutic options for the reproductive dysfunction associated with states of relative leptin deficiency or resistance.

Non-Cooperative Regulation Coordination Based on Game Theory for Wind Farm Clusters during Ramping Events

DEFF Research Database (Denmark)

Qi, Yongzhi; Liu, Yutian; Wu, Qiuwei

2017-01-01

With increasing penetration of wind power in power systems, it is important to track scheduled wind power output as much as possible during ramping events to ensure security of the system. In this paper, a non‐cooperative coordination strategy based on the game theory is proposed for the regulation...... of the regulation revenue function according to the derived Nash equilibrium condition, the ER strategy is the Nash equilibrium of the regulation competition. Case studies were conducted with the power output data of wind farms from State Grid Jibei Electric Power Company Limited of China to demonstrate...

Trait Affect, Emotion Regulation, and the Generation of Negative and Positive Interpersonal Events.

Science.gov (United States)

Hamilton, Jessica L; Burke, Taylor A; Stange, Jonathan P; Kleiman, Evan M; Rubenstein, Liza M; Scopelliti, Kate A; Abramson, Lyn Y; Alloy, Lauren B

2017-07-01

Positive and negative trait affect and emotion regulatory strategies have received considerable attention in the literature as predictors of psychopathology. However, it remains unclear whether individuals' trait affect is associated with responses to state positive affect (positive rumination and dampening) or negative affect (ruminative brooding), or whether these affective experiences contribute to negative or positive interpersonal event generation. Among 304 late adolescents, path analyses indicated that individuals with higher trait negative affect utilized dampening and brooding rumination responses, whereas those with higher trait positive affect engaged in rumination on positive affect. Further, there were indirect relationships between trait negative affect and fewer positive and negative interpersonal events via dampening, and between trait positive affect and greater positive and negative interpersonal events via positive rumination. These findings suggest that individuals' trait negative and positive affect may be associated with increased utilization of emotion regulation strategies for managing these affects, which may contribute to the occurrence of positive and negative events in interpersonal relationships. Copyright © 2017. Published by Elsevier Ltd.

77 FR 23599 - Special Local Regulations for Marine Events; Potomac River, Charles County, MD

Science.gov (United States)

2012-04-20

... was held. Background and Purpose On June 2, 2012, Enviro-Sports Productions, Inc. of Stinson Beach... regulations. The commenter, Mr. David R. Horning of EnviroSports, who is the event organizer, stated that... substantial direct effect on the States, on the relationship between the national government and the States...

Serial binary interval ratios improve rhythm reproduction

Directory of Open Access Journals (Sweden)

Xiang eWu

2013-08-01

Full Text Available Musical rhythm perception is a natural human ability that involves complex cognitive processes. Rhythm refers to the organization of events in time, and musical rhythms have an underlying hierarchical metrical structure. The metrical structure induces the feeling of a beat and the extent to which a rhythm induces the feeling of a beat is referred to as its metrical strength. Binary ratios are the most frequent interval ratio in musical rhythms. Rhythms with hierarchical binary ratios are better discriminated and reproduced than rhythms with hierarchical non-binary ratios. However, it remains unclear whether a superiority of serial binary over non-binary ratios in rhythm perception and reproduction exists. In addition, how different types of serial ratios influence the metrical strength of rhythms remains to be elucidated. The present study investigated serial binary vs. non-binary ratios in a reproduction task. Rhythms formed with exclusively binary (1:2:4:8, non-binary integer (1:3:5:6, and non-integer (1:2.3:5.3:6.4 ratios were examined within a constant meter. The results showed that the 1:2:4:8 rhythm type was more accurately reproduced than the 1:3:5:6 and 1:2.3:5.3:6.4 rhythm types, and the 1:2.3:5.3:6.4 rhythm type was more accurately reproduced than the 1:3:5:6 rhythm type. Further analyses showed that reproduction performance was better predicted by the distribution pattern of event occurrences within an inter-beat interval, than by the coincidence of events with beats, or the magnitude and complexity of interval ratios. Whereas rhythm theories and empirical data emphasize the role of the coincidence of events with beats in determining metrical strength and predicting rhythm performance, the present results suggest that rhythm processing may be better understood when the distribution pattern of event occurrences is taken into account. These results provide new insights into the mechanisms underlining musical rhythm perception.

Serial binary interval ratios improve rhythm reproduction.

Science.gov (United States)

Wu, Xiang; Westanmo, Anders; Zhou, Liang; Pan, Junhao

2013-01-01

Musical rhythm perception is a natural human ability that involves complex cognitive processes. Rhythm refers to the organization of events in time, and musical rhythms have an underlying hierarchical metrical structure. The metrical structure induces the feeling of a beat and the extent to which a rhythm induces the feeling of a beat is referred to as its metrical strength. Binary ratios are the most frequent interval ratio in musical rhythms. Rhythms with hierarchical binary ratios are better discriminated and reproduced than rhythms with hierarchical non-binary ratios. However, it remains unclear whether a superiority of serial binary over non-binary ratios in rhythm perception and reproduction exists. In addition, how different types of serial ratios influence the metrical strength of rhythms remains to be elucidated. The present study investigated serial binary vs. non-binary ratios in a reproduction task. Rhythms formed with exclusively binary (1:2:4:8), non-binary integer (1:3:5:6), and non-integer (1:2.3:5.3:6.4) ratios were examined within a constant meter. The results showed that the 1:2:4:8 rhythm type was more accurately reproduced than the 1:3:5:6 and 1:2.3:5.3:6.4 rhythm types, and the 1:2.3:5.3:6.4 rhythm type was more accurately reproduced than the 1:3:5:6 rhythm type. Further analyses showed that reproduction performance was better predicted by the distribution pattern of event occurrences within an inter-beat interval, than by the coincidence of events with beats, or the magnitude and complexity of interval ratios. Whereas rhythm theories and empirical data emphasize the role of the coincidence of events with beats in determining metrical strength and predicting rhythm performance, the present results suggest that rhythm processing may be better understood when the distribution pattern of event occurrences is taken into account. These results provide new insights into the mechanisms underlining musical rhythm perception.

Targeted Mutagenesis of the Hypophysiotropic Gnrh3 in Zebrafish (Danio rerio Reveals No Effects on Reproductive Performance.

Directory of Open Access Journals (Sweden)

Olivia Smith Spicer

Full Text Available Gnrh is the major neuropeptide regulator of vertebrate reproduction, triggering a cascade of events in the pituitary-gonadal axis that result in reproductive competence. Previous research in mice and humans has demonstrated that Gnrh/GNRH null mutations result in hypogonadotropic hypogonadism and infertility. The goal of this study was to eliminate gnrh3 (the hypophysiotropic Gnrh form function in zebrafish (Danio rerio to determine how ontogeny and reproductive performance are affected, as well as factors downstream of Gnrh3 along the reproductive axis. Using the TALEN technology, we developed a gnrh3-/- zebrafish line that harbors a 62 bp deletion in the gnrh3 gene. Our gnrh3-/- zebrafish line represents the first targeted and heritable mutation of a Gnrh isoform in any organism. Using immunohistochemistry, we verified that gnrh3-/- fish do not possess Gnrh3 peptide in any regions of the brain. However, other than changes in mRNA levels of pituitary gonadotropin genes (fshb, lhb, and cga during early development, which are corrected by adulthood, there were no changes in ontogeny and reproduction in gnrh3-/- fish. The gnrh3-/- zebrafish are fertile, displaying normal gametogenesis and reproductive performance in males and females. Together with our previous results that Gnrh3 cell ablation causes infertility, these results indicate that a compensatory mechanism is being activated, which is probably primed early on upon Gnrh3 neuron differentiation and possibly confined to Gnrh3 neurons. Potential compensation factors and sensitive windows of time for compensation during development and puberty should be explored.

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.

RFRP neurons - the doorway to understanding seasonal reproduction in mammals

Directory of Open Access Journals (Sweden)

Jo Beldring Henningsen

2016-05-01

Full Text Available Seasonal control of reproduction is critical for the perpetuation of species living in temperate zones that display major changes in climatic environment and availability of food resources. In mammals, seasonal cues are mainly provided by the annual change in the 24h light/dark ratio (i.e. photoperiod, which is translated into the nocturnal production of the pineal hormone melatonin. The annual rhythm in this melatonin signal acts as a synchronizer ensuring that breeding occurs when environmental conditions favor survival of the offspring. Although specific mechanisms might vary among seasonal species, the hypothalamic RF (Arg-Phe amide-related peptides (RFRP-1 and -3 are believed to play a critical role in the central control of seasonal reproduction and in all seasonal species investigated, the RFRP system is persistently inhibited in short photoperiod. Central chronic administration of RFRP-3 in short day-adapted male Syrian hamsters fully reactivates the reproductive axis despite photoinhibitory conditions, which highlights the importance of the seasonal changes in RFRP expression for proper regulation of the reproductive axis. The acute effects of RFRP peptides, however, depend on species, photoperiod and recent studies point towards a different role of RFRP in regulating female reproductive activity. In this review we summarize the recent advances made to understand the role and underlying mechanisms of RFRP in the seasonal control of reproduction, primarily focusing on mammalian species.

An experimental test for age-related improvements in reproductive performance in a frog that cares for its young

Science.gov (United States)

Dugas, Matthew B.; Moore, Michael P.; Wamelink, Caitlin N.; Richards-Zawacki, Corinne L.; Martin, Ryan A.

2015-10-01

Reproductive performance often increases with age in long-lived iteroparous organisms, a pattern that can result from within-individual increases in effort and/or competence. In free-living populations, it is typically difficult to distinguish these mechanisms or to isolate particular features of reproduction-influencing outcomes. In captive Oophaga pumilio, a frog in which mothers provide extended offspring provisioning via trophic eggs, we experimentally manipulated the age at which females started breeding and then monitored them across repeated reproductive events. This experiment allowed us to decouple age and experience and isolate maternal care as the proximate source of any differences in performance. Younger first-time mothers produced larger broods than older first-time mothers, but did not rear more offspring to independence. Across repeated reproductive events, maternal age was unassociated with any metric of performance. At later reproductive events, however, mothers produced fewer metamorphs, and a lower proportion of individuals in their broods reached independence. These patterns suggest that performance does not improve with age or breeding experience in this frog, and that eventual declines in performance are driven by reproductive activity, not age per se. Broadly, age-specific patterns of reproductive performance may depend on the proximate mechanism by which parents influence offspring fitness and how sensitive these are to effort and competence.

Regulating (for the benefit of) future persons: a different perspective on the FDA's jurisdiction to regulate human reproductive cloning.

Science.gov (United States)

Javitt, Gail H; Hudson, Kathy

2003-01-01

The Food and Drug Administration (FDA) has taken the position that human reproductive cloning falls within its regulatory jurisdiction. This position has been subject to criticism on both procedural and substantive grounds. Some have contended that the FDA has failed to follow administrative law principles in asserting its jurisdiction, while others claim the FDA is ill suited to the task of addressing the ethical and social implications of human cloning. This Article argues, that, notwithstanding these criticisms, the FDA could plausibly assert jurisdiction over human cloning as a form of human gene therapy, an area in which the FDA is already regarded as having primary regulatory authority. Such an assertion would require that the FDA's jurisdiction extend to products affecting future persons, i.e., those not yet born. This Article demonstrates, for the first time, that such jurisdiction was implicit in the enactment of the 1962 Kefauver-Harris Amendments to the Federal Food, Drug, and Cosmetic Act and that the FDA has historically relied on such authority in promulgating regulations for drugs and devices.

Kisspeptin Antagonists Reveal Kisspeptin 1 and Kisspeptin 2 Differential Regulation of Reproduction in the Teleost, Morone saxatilis.

Science.gov (United States)

Zmora, Nilli; Stubblefield, John David; Wong, Ten-Tsao; Levavi-Sivan, Berta; Millar, Robert Peter; Zohar, Yonathan

2015-09-01

The importance of kisspeptin in regulating vertebrate reproduction has been well established, but the exact mechanism continues to unfold. Unlike mammals, many lower vertebrates possess a dual kisspeptin system, Kiss1 and Kiss2. To decipher the roles of the kisspeptins in fish, we identified two potential kisspeptin antagonists, pep 234 and pep 359, by screening analogs for their ability to inactivate striped bass Kiss1 and Kiss2 receptors expressed in COS7 cells. Pep 234 (a mammalian KISS1 antagonist) antagonizes Kiss1r signaling activated by Kiss1 and Kiss2, and pep 359 (a novel analog) antagonizes Kiss2 activation of both receptors. In vitro studies using brain slices demonstrated that only Kiss2 can upregulate the expression of the hypophysiotropic gnrh1, which was subsequently diminished by pep 234 and pep 359. In primary pituitary cell cultures, the two antagonists revealed a complex network of putative endogenous and exogenous regulation by kisspeptin. While both kisspeptins stimulate Fsh expression and secretion, Kiss2 predominately induces Lh secretion. Pep 234 and 359 treatment of spawning males hindered sperm production. This effect was accompanied with decreased brain gnrh1 and gnrh2 mRNA levels and peptide content in the pituitary, and increased levels of pituitary Lh, probably due to attenuation of Lh release. Strikingly, the mRNA levels of arginine-vasotocin, the neurons of which in the preoptic area coexpress kiss2r, were dramatically reduced by the antagonists. Our results demonstrate differential actions of Kiss1 and Kiss2 systems along the hypothalamic-pituitary axis and interactions with other neuropeptides, and further reinforce the importance of kisspeptin in the execution of spawning. © 2015 by the Society for the Study of Reproduction, Inc.

Reproduction and biochemical responses in Enchytraeus albidus (Oligochaeta) to zinc or cadmium exposures

Energy Technology Data Exchange (ETDEWEB)

Novais, Sara C., E-mail: sara.novais@ua.pt [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal); Gomes, Susana I.L. [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal); Gravato, Carlos [CIIMAR-Centro Interdisciplinar de Investigacao Marinha e Ambiental, Laboratorio de Ecotoxicologia e Ecologia, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Guilhermino, Lucia [CIIMAR-Centro Interdisciplinar de Investigacao Marinha e Ambiental, Laboratorio de Ecotoxicologia e Ecologia, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); ICBAS-Instituto de Ciencias Biomedicas Abel Salazar, Departamento de Estudos de Populacoes, Laboratorio de Ecotoxicologia, Universidade do Porto, Porto (Portugal); De Coen, Wim [University of Antwerp, Department of Biology - E.B.T., Groenenborgerlaan 171 - U.7., B-2020 Antwerp (Belgium); Soares, Amadeu M.V.M.; Amorim, Monica J.B. [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal)

2011-07-15

To better understand chemical modes of action, emphasis has been given to stress responses at lower levels of biological organization. Cholinesterases and antioxidant defenses are among the most used biomarkers due to their crucial role in the neurocholinergic transmission and in cell homeostasis preventing DNA damage, enzymatic inactivation and lipid peroxidation. The main goal of this study was to investigate the effects of zinc and cadmium on survival and reproduction of E. albidus and to assess metals oxidative stress potential and neurotoxic effects at concentrations that affected reproduction. Both metals affected the enchytraeids' survival and reproduction and induced significant changes in the antioxidant defenses as well as increased lipid peroxidation, indicating oxidative damage. This study demonstrates that determining effects at different levels of biological organization can give better information on the physiological responses of enchytraeids in metal contamination events and further unravel the mechanistic processes dealing with metal stress. - Highlights: > Zinc and cadmium influence the survival and reproduction of Enchytraeus albidus. > Oxidative stress and membrane damage occur at reproduction effect concentrations. > Glutathione seems to be important in the antioxidant defense against metals. > Time intervals (2, 4, 8 days) allowed following the evolution of oxidative events. - Zinc and cadmium cause oxidative stress and membrane damage in Enchytraeus albidus at reproduction effect concentrations.

Reproduction and biochemical responses in Enchytraeus albidus (Oligochaeta) to zinc or cadmium exposures

International Nuclear Information System (INIS)

Novais, Sara C.; Gomes, Susana I.L.; Gravato, Carlos; Guilhermino, Lucia; De Coen, Wim; Soares, Amadeu M.V.M.; Amorim, Monica J.B.

2011-01-01

To better understand chemical modes of action, emphasis has been given to stress responses at lower levels of biological organization. Cholinesterases and antioxidant defenses are among the most used biomarkers due to their crucial role in the neurocholinergic transmission and in cell homeostasis preventing DNA damage, enzymatic inactivation and lipid peroxidation. The main goal of this study was to investigate the effects of zinc and cadmium on survival and reproduction of E. albidus and to assess metals oxidative stress potential and neurotoxic effects at concentrations that affected reproduction. Both metals affected the enchytraeids' survival and reproduction and induced significant changes in the antioxidant defenses as well as increased lipid peroxidation, indicating oxidative damage. This study demonstrates that determining effects at different levels of biological organization can give better information on the physiological responses of enchytraeids in metal contamination events and further unravel the mechanistic processes dealing with metal stress. - Highlights: → Zinc and cadmium influence the survival and reproduction of Enchytraeus albidus. → Oxidative stress and membrane damage occur at reproduction effect concentrations. → Glutathione seems to be important in the antioxidant defense against metals. → Time intervals (2, 4, 8 days) allowed following the evolution of oxidative events. - Zinc and cadmium cause oxidative stress and membrane damage in Enchytraeus albidus at reproduction effect concentrations.

Reproductive factors and risk of mortality in the European Prospective Investigation into Cancer and Nutrition; a cohort study

NARCIS (Netherlands)

Merritt, Melissa A.; Riboli, Elio; Murphy, Neil; Kadi, Mai; Tjønneland, Anne; Olsen, Anja; Overvad, Kim; Dossus, Laure; Dartois, Laureen; Clavel-Chapelon, Françoise; Fortner, Renée T.; Katzke, Verena A.; Boeing, Heiner; Trichopoulou, Antonia; Lagiou, Pagona; Trichopoulos, Dimitrios; Palli, Domenico; Sieri, Sabina; Tumino, Rosario; Sacerdote, Carlotta; Panico, Salvatore; Bueno-de-Mesquita, H. Bas; Peeters, Petra H.; Lund, Eiliv; Nakamura, Aurelie; Weiderpass, Elisabete; Quirós, J. Ramón; Agudo, Antonio; Molina-Montes, Esther; Larrañaga, Nerea; Dorronsoro, Miren; Cirera, Lluís; Barricarte, Aurelio; Olsson, Åsa; Butt, Salma; Idahl, Annika; Lundin, Eva; Wareham, Nicholas J.; Key, Timothy J.; Brennan, Paul; Ferrari, Pietro; Wark, Petra A.; Norat, Teresa; Cross, Amanda J.; Gunter, Marc J.

2015-01-01

Background: Reproductive events are associated with important physiologic changes, yet little is known about how reproductive factors influence long-term health in women. Our objective was to assess the relation of reproductive characteristics with all-cause and cause-specific mortality risk.

Nutritional stress in Northern gannets during an unprecedented low reproductive success year: can extreme sea surface temperature event and dietary change be the cause?

Science.gov (United States)

Franci, Cynthia D; Vézina, François; Grégoire, François; Rail, Jean-François; Verreault, Jonathan

2015-03-01

Reproductive success of seabirds is tightly associated with availability of their prey for which the spatiotemporal distribution may be influenced by sea surface temperature (SST) fluctuations. The objective of this study was to investigate whether Northern gannets (Morus bassanus) from the largest colony in North America (Bonaventure Island, Quebec, Canada) were in negative nutritional state during the unprecedented low reproductive success year of 2012, and whether this was associated with changes in SST anomalies and diet. The incubation period of gannets in 2012 was characterized by a significant decline, from early to late incubation, in plasma triglyceride levels that was associated with an increase in plasma corticosterone levels. However, no changes in plasma glycerol and β-hydroxybutyrate levels were noted. SST anomalies recorded in this area (south of the Gulf of St. Lawrence) during the breeding period were consistently higher in 2012 compared to the previous year (a better reproductive success year). Based on signatures of stable carbon (δ(13)C) and nitrogen (δ(15)N) isotopes in gannet red blood cells and in whole fish homogenates of three major preys (mackerel, herring, and capelin), a minor dietary shift was noted between those years and incubation periods. In light of these findings, it is suggested that the extreme warm-water perturbation event that prevailed in the Gulf of St. Lawrence during summer 2012 was associated with a rapid deterioration of nutritional condition of Bonaventure Island gannets during the incubation. These suboptimal physiological changes likely contributed to the dramatic decline in reproductive success reported in this colony. Copyright © 2014 Elsevier Inc. All rights reserved.

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).

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.

Lysophosphatidic Acid (LPA Signaling in Human and Ruminant Reproductive Tract

Directory of Open Access Journals (Sweden)

Izabela Wocławek-Potocka

2014-01-01

Full Text Available Lysophosphatidic acid (LPA through activating its G protein-coupled receptors (LPAR 1–6 exerts diverse cellular effects that in turn influence several physiological processes including reproductive function of the female. Studies in various species of animals and also in humans have identified important roles for the receptor-mediated LPA signaling in multiple aspects of human and animal reproductive tract function. These aspects range from ovarian and uterine function, estrous cycle regulation, early embryo development, embryo implantation, decidualization to pregnancy maintenance and parturition. LPA signaling can also have pathological consequences, influencing aspects of endometriosis and reproductive tissue associated tumors. The review describes recent progress in LPA signaling research relevant to human and ruminant reproduction, pointing at the cow as a relevant model to study LPA influence on the human reproductive performance.

Role of leptin in female reproduction.

Science.gov (United States)

Pérez-Pérez, Antonio; Sánchez-Jiménez, Flora; Maymó, Julieta; Dueñas, José L; Varone, Cecilia; Sánchez-Margalet, Víctor

2015-01-01

Reproductive function is dependent on energy resources. The role of weight, body composition, fat distribution and the effect of diet have been largely investigated in experimental female animals as well as in women. Any alteration in diet and/or weight may induce abnormalities in timing of sexual maturation and fertility. However, the cellular mechanisms involved in the fine coordination of energy balance and reproduction are largely unknown. The brain and hypothalamic structures receive endocrine and/or metabolic signals providing information on the nutritional status and the degree of fat stores. Adipose tissue acts both as a store of energy and as an active endocrine organ, secreting a large number of biologically important molecules termed adipokines. Adipokines have been shown to be involved in regulation of the reproductive functions. The first adipokine described was leptin. Extensive research over the last 10 years has shown that leptin is not only an adipose tissue-derived messenger of the amount of energy stores to the brain, but also a crucial hormone/cytokine for a number of diverse physiological processes, such as inflammation, angiogenesis, hematopoiesis, immune function, and most importantly, reproduction. Leptin plays an integral role in the normal physiology of the reproductive system with complex interactions at all levels of the hypothalamic-pituitary gonadal (HPG) axis. In addition, leptin is also produced by placenta, where it plays an important autocrine function. Observational studies have demonstrated that states of leptin excess, deficiency, or resistance can be associated with abnormal reproductive function. This review focuses on the leptin action in female reproduction.

Flight attendant radiation dose from solar particle events.

Science.gov (United States)

Anderson, Jeri L; Mertens, Christopher J; Grajewski, Barbara; Luo, Lian; Tseng, Chih-Yu; Cassinelli, Rick T

2014-08-01

Research has suggested that work as a flight attendant may be related to increased risk for reproductive health effects. Air cabin exposures that may influence reproductive health include radiation dose from galactic cosmic radiation and solar particle events. This paper describes the assessment of radiation dose accrued during solar particle events as part of a reproductive health study of flight attendants. Solar storm data were obtained from the National Oceanic and Atmospheric Administration Space Weather Prediction Center list of solar proton events affecting the Earth environment to ascertain storms relevant to the two study periods (1992-1996 and 1999-2001). Radiation dose from exposure to solar energetic particles was estimated using the NAIRAS model in conjunction with galactic cosmic radiation dose calculated using the CARI-6P computer program. Seven solar particle events were determined to have potential for significant radiation exposure, two in the first study period and five in the second study period, and over-lapped with 24,807 flight segments. Absorbed (and effective) flight segment doses averaged 6.5 μGy (18 μSv) and 3.1 μGy (8.3 μSv) for the first and second study periods, respectively. Maximum doses were as high as 440 μGy (1.2 mSv) and 20 flight segments had doses greater than 190 μGy (0.5 mSv). During solar particle events, a pregnant flight attendant could potentially exceed the equivalent dose limit to the conceptus of 0.5 mSv in a month recommended by the National Council on Radiation Protection and Measurements.

Revisiting reproduction and population structure and dynamics of Procambarus clarkii eight years after its introduction into Lake Trasimeno (Central Italy

Directory of Open Access Journals (Sweden)

Dörr A.J.M.

2013-06-01

Full Text Available Understanding population dynamics and regulation is fundamental for predicting establishment and spread of invasive alien species. In addition, the population biology of invasive alien species offers an opportunity to study basic ecological processes. In this context, we investigated reproductive and growth plasticity in the invasive crayfish Procambarus clarkii in Lake Trasimeno (central Italy. In total, 3153 crayfish were collected monthly from June 2007 to July 2009. The molt status was assessed by evaluating the exoskeleton hardness. To assess the reproductive cycle, the gonado-somatic and wet hepato-somatic indices were calculated for females. The reproductive status of males was appraised as well. We estimated growth and longevity using the von Bertalanffy growth function, and calculated the total, natural and fishing mortality indices. We then compared our present data with those obtained from the same population eight years before. Our results indicate some changes in population dynamics and in both molting and reproductive periods since the initial invasion of the shallow lake investigated. Long-term differences in the life history of the Trasimeno population may be the result of selective pressures different from those of the native range, but may also result from colonization events and human interference caused by professional fishing activities.

How to address the ethics of reproductive travel to developing countries: a comparison of national self-sufficiency and regulated market approaches.

Science.gov (United States)

Crozier, G K D; Martin, Dominique

2012-04-01

One of the areas of concern raised by cross-border reproductive travel regards the treatment of women who are solicited to provide their ova or surrogacy services to foreign consumers. This is particularly troublesome in the context of developing countries where endemic poverty and low standards for both medical care and informed consent may place these women at risk of exploitation and harm. We explore two contrasting proposals for policy development regarding the industry, both of which seek to promote ethical outcomes and social justice: While one proposal advocates efforts to minimize cross-border demand for female reproductive resources through the pursuit of national self-sufficiency, the other defends cross-border trade as a means for meeting the needs of vulnerable groups. Despite the conflicting objectives of the proposed strategies, the paper identifies common values and points of agreement between the two, including the importance of regulations to safeguard those providing ova or surrogacy services. © 2012 Blackwell Publishing Ltd.

76 FR 80850 - Special Local Regulations and Safety Zones; Recurring Events in Northern New England

Science.gov (United States)

2011-12-27

..., design, or operation; test methods; sampling procedures; and related management systems practices) that... safety of life or property. (f) For all power boat races listed, vessels operating within the regulated... that will not interfere with the progress of the event. (g) For all regattas and boat parades listed...

Research progress on the role of melatonin and its receptors in animal reproduction: A comprehensive review.

Science.gov (United States)

Talpur, H S; Chandio, I B; Brohi, R D; Worku, T; Rehman, Z; Bhattarai, D; Ullah, F; JiaJia, L; Yang, L

2018-04-16

Melatonin and its receptors play a crucial role in the regulation of the animal reproductive process, primarily in follicular development. However, the role that melatonin performs in regulating hormones related with reproduction remains unclear. Melatonin and its receptors are present both in female and male animals' organs, such as ovaries, heart, brain and liver. Melatonin regulates ovarian actions and is a key mediator of reproductive actions. Melatonin has numerous effects on animal reproduction, such as protection of gametes and embryos, response to clock genes, immune-neuroendocrine, reconciliation of seasonal variations in immune function, and silence or blockage of genes. The growth ratio of reproductive illnesses in animals has raised a remarkable concern for the government, animal caretakers and farm managers. In order to resolve this challenging issue, it is very necessary to conduct state-of-the-art research on melatonin and its receptors because melatonin has considerable physiognomies. This review article presents a current contemporary research conducted by numerous researchers from the entire world on the role of melatonin and its receptors in animal reproduction, from the year 1985 to the year 2017. Furthermore, this review shows scientific research challenges related to melatonin receptors and their explanations based on the findings of 172 numerous research articles, and also represents significant proficiencies of melatonin in order to show enthusiastic study direction for animal reproduction researchers. © 2018 The Authors. Reproduction in Domestic Animals Published by Blackwell Verlag GmbH.

Reproduction in the Genetic Age: A Proposed Scheme for the Regulation of Assisted Reproductive Technologies

OpenAIRE

Lindstrom, Laura J.

2002-01-01

In the last several years, there have been a number of advances in the area of assisted (or advanced) reproductive technology (ART) that are so fantastic that they strain the credulity of even those well-versed in medicine and science. Moreover, the potential medical, legal, psychological, and social repercussions of the applications of these technologies cause most people who hear about their use to worry somewhat about the ramifications. In fact, part of the general fear of these technologi...

Effects of environment on buffalo reproduction

Directory of Open Access Journals (Sweden)

W. G. Vale

2010-02-01

Full Text Available It has been long recognized that the environment has an important role to play in the regulation of the mammalian reproductive function. Environmental cues, such as changing day-light or increase temperature, are know to trigger off growth or regression of the reproductive organs in a whole variety of species and nutrition and stress can influence the onset of breeding and affect the fertility. Although the domestic buffalo (Bubalus bubalis has been since long time considered as a short-day-breeder polyestral seasonal animal, indeed in the tropical areas near of equator line they are polyestral continuous. It would seem that photoperiod has a marked influence in buffalo reproduction in determinate areas of the world, however in some tropical areas like in Brazil, mainly in the Amazon valley and areas nearest of the equator the light seems to have a minimal effect or no effect on the reproductive cues however the nutrition and heat stress measured throughout temperature/ humidity indexes (THI play an important role in the reproductive functions of buffaloes and it is suggested that THI >75 has a negative effect on reproductive performances of buffaloes. The calving season is regulated by the availability of native pasture in the floodplain or in areas of artificial pasture On the other hand when buffaloes are raised in the southwest and southern regions (parallels 14 to 33 South they show a typical seasonal pattern when the calving season are concentrated between de February to July. The body condition score (BCS seems to affect directly the fertility of female buffaloes since females that calve with a BCS < 2.5 show delayed postpartum ovulation, weak estrus symptoms and more service per conception rate. Seasonal anestrus is a normal phenomenon in the out breeding season that occur in areas near, upon or down of the Cancer and Capricorn lines, respectively, however the anoestrus can be overcame by the use of hormone to synchronize heat and

Kisspeptins and RFRP-3 act in concert to synchronize rodent reproduction with seasons

Directory of Open Access Journals (Sweden)

Valerie eSimonneaux

2013-02-01

Full Text Available Seasonal mammals use the photoperiodic variation in the nocturnal production of the pineal hormone melatonin to synchronize their reproductive activity with seasons. In rodents, the short day profile of melatonin secretion has long been proven to inhibit reproductive activity. Lately, we demonstrated that melatonin regulates the expression of the hypothalamic peptides kisspeptins (Kp and RFamide-related peptide-3 (RFRP-3, recently discovered as potent regulators of GnRH neuron activity. In the male Syrian hamster, Kp expression in the arcuate nucleus is down-regulated by melatonin independently of the inhibitory feedback of testosterone. A central or peripheral administration of Kp induces an increase in pituitary gonadotropins and gonadal hormone secretion, but most importantly a chronic infusion of the peptide reactivates the photoinhibited reproductive axis of Syrian hamsters kept in short day conditions. RFRP-3 expression in the dorsomedial hypothalamus is also strongly inhibited by melatonin in a short day photoperiod. Although RFRP-3 is usually considered as an inhibitory component of the gonadotropic axis, a central acute administration of RFRP-3 in the male Syrian hamster induces a marked increase in gonadotropin secretion and testosterone production. Furthermore, a chronic central infusion of RFRP-3 in short day-adapted hamsters reactivates the reproductive axis, in the same manner as Kp. Both Kp and RFRP-3 neurons project onto GnRH neurons and both neuropeptides regulate GnRH neuron activity. In addition, central RFRP-3 infusion was associated with a significant increase in arcuate Kp expression. However, the actual sites of action of both peptides in the Syrian hamster brain are still unknown. Altogether our findings indicate that Kp and RFRP neurons are pivotal relays for the seasonal regulation of reproduction, and also suggest that RFRP neurons might be the primary target of the melatoninergic message.

Natural methods for increasing reproductive efficiency in small ruminants.

Science.gov (United States)

Martin, G B; Milton, J T B; Davidson, R H; Banchero Hunzicker, G E; Lindsay, D R; Blache, D

2004-07-01

This paper describes three strategies to improve the reproductive performance of small ruminants in ways that lead to "clean, green and ethical" animal production. The first is aimed at control of the timing of reproductive events for which we turn to the socio-sexual inputs of the "male effect" to induce synchronised ovulation in females that would otherwise be anovulatory. The second strategy, "focussed feeding", is based on our knowledge of the responses to nutrition and aims to develop short programs of nutritional supplements that are precisely timed and specifically designed for individual events in the reproductive process, such as gamete production, embryo survival, fetal programming and colostrum production. The third strategy aims to maximise offspring survival by a combination of management, nutrition and genetic selection for behavior (temperament). All of these approaches involve non-pharmacological manipulation of the endogenous control systems of the animals and complement the detailed information from ultrasound that is now becoming available. The use of such clean, green and ethical tools in the management of our animals can be cost-effective, increase productivity and, at the same time, greatly improve the image of meat and milk industries in society and the marketplace.

Marketing of Assisted Human Reproduction and the Indian State

OpenAIRE

Shree Mulay; Emily Gibson

2006-01-01

Shree Mulay and Emily Gibson examine the factors responsible for the phenomenal growth of the private fee-for-service health sector in India and the industry related to Assisted Human Reproduction, its negative effect on the public health sector as well as the feeble attempts by the Indian state to regulate this industry, and its implications for women's reproductive rights and health. Development (2006) 49, 84–93. doi:10.1057/palgrave.development.1100311

Effects of task complexity on rhythmic reproduction performance in adults.

Science.gov (United States)

Iannarilli, Flora; Vannozzi, Giuseppe; Iosa, Marco; Pesce, Caterina; Capranica, Laura

2013-02-01

The aim of the present study was to investigate the effect of task complexity on the capability to reproduce rhythmic patterns. Sedentary musically illiterate individuals (age: 34.8±4.2 yrs; M±SD) were administered a rhythmic test including three rhythmic patterns to be reproduced by means of finger-tapping, foot-tapping and walking. For the quantification of subjects' ability in the reproduction of rhythmic patterns, qualitative and quantitative parameters were submitted to analysis. A stereophotogrammetric system was used to reconstruct and evaluate individual performances. The findings indicated a good internal stability of the rhythmic reproduction, suggesting that the present experimental design is suitable to discriminate the participants' rhythmic ability. Qualitative aspects of rhythmic reproduction (i.e., speed of execution and temporal ratios between events) varied as a function of the perceptual-motor requirements of the rhythmic reproduction task, with larger reproduction deviations in the walking task. Copyright © 2013 Elsevier B.V. All rights reserved.

Thyroid hormone actions on male reproductive system of teleost fish.

Science.gov (United States)

Tovo-Neto, Aldo; da Silva Rodrigues, Maira; Habibi, Hamid R; Nóbrega, Rafael Henrique

2018-04-17

Thyroid hormones (THs) play important roles in the regulation of many biological processes of vertebrates, such as growth, metabolism, morphogenesis and reproduction. An increasing number of studies have been focused on the involvement of THs in the male reproductive system of vertebrates, in particular of fish. Therefore, this mini-review aims to summarize the main findings on THs role in male reproductive system of fish, focusing on sex differentiation, testicular development and spermatogenesis. The existing data in the literature have demonstrated that THs exert their roles at the different levels of the hypothalamic-pituitary-gonadal (HPG) axis. In general a positive correlation has been shown between THs and fish reproductive status; where THs are associated with testicular development, growth and maturation. Recently, the molecular mechanisms underlying the role of THs in spermatogenesis have been unraveled in zebrafish testis. THs promote germ cell proliferation and differentiation by increasing a stimulatory growth factor of spermatogenesis produced by Sertoli cells. In addition, THs enhanced the gonadotropin-induced androgen release in zebrafish testis. Next to their functions in the adult testis, THs are involved in the gonadal sex differentiation through modulating sex-related gene expression, and testicular development via regulation of Sertoli cell proliferation. In conclusion, this mini-review showed that THs modulate the male reproductive system during the different life stages of fish. The physiological and molecular mechanisms showed a link between the thyroid and reproduction, suggesting a possibly co-evolution and interdependence of these two systems. Copyright © 2018 Elsevier Inc. All rights reserved.

76 FR 17530 - Special Local Regulations and Safety Zones; Recurring Events in Northern New England

Science.gov (United States)

2011-03-30

... available in the docket, are part of docket USCG-2010-0110 and are available online by going to http://www...[deg] 21'36'' W. 7.7 Friendship Lobster Boat Races. Event Type: Power Boat Race. Sponsor: Friendship...: The regulated area includes all waters of Friendship Harbor, Maine within the following points (NAD 83...

Gross morphology and ultrastructure of the female reproductive system of Diaphorina citri (Hemiptera: Liviidae

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Fabio Cleisto Alda Dossi

2014-04-01

Full Text Available The morphological traits of the female reproductive system of Diaphorina citri were examined in detail. Diaphorina citri has telotrophic ovaries with ovarioles organized as a "bouquet", displaying a rudimentary terminal filament and a syncytial tropharium. The vitellarium carries a single growing oocyte at each maturation cycle, which is connected with the tropharium by a nutritive cord. Morpho-functional changes occur during oocyte development, mainly during mid to late vitellogenesis. Morphological events such as the patency of the follicular cells and the intense traffic of vesicles through para- or intracellular processes, suggest a possible route for endosymbiont invasion of D. citri reproductive tissues. Similar events have been demonstrated to be involved in the process of ovariole invasion by endosymbionts in other sternorrhynchans that share reproductive traits with psyllids.

Plant Reproduction and the Pollen Tube Journey--How the Females Lure the Males

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Lorbiecke, Rene

2012-01-01

The growth of pollen tubes is one of the most characteristic events in angiosperm reproduction. This article describes an activity for visualizing the journey and guidance of pollen tubes in the reproductive structures of a flowering plant. The activity uses a semi-in vivo system with rapid-cycling "Brassica rapa," also known as Fast Plants.…

Unravelling orders in a borderless Europe? Cross-border reproductive care and the paradoxes of assisted reproductive technology policy in Germany and Poland

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Tracie L. Wilson

2016-12-01

Full Text Available This article examines assisted reproduction policy and practices in Germany and Poland. Germany is among the most restrictive countries in the European Union (EU with respect to assisted reproductive technologies. In contrast, Poland only recently passed legislation regulating assisted reproductive technologies. Before this, most practices were unregulated, despite vocal opposition to all forms of IVF from conservative Roman Catholic activists. Germany and Poland differ significantly regarding the cultural narratives and historical experience that impact attitudes toward reproduction. In Germany, discussions on assisted reproduction often invoke concerns about medical intervention in ethically complex matters, due – in part – to the country’s National Socialist past. My objectives in this article centre on examining assisted reproduction contexts in each of these two countries, with attention to the framing of debates on reproduction, the anxieties that inform them, and the resulting paradoxes. I consider the unintended consequences of domestic policy and their importance regarding cross-border reproductive care (CBRC. Within the borderless EU, the widespread practice of CBRC demonstrates the ineffectiveness of national policies. Moreover, this shift in location can impact practices and trends found in other accessible, but less restrictive countries. Of particular concern are the relocation of risk to ‘bioavailable’ populations in less affluent countries and the reification of cultural and socio-economic hierarchies.

Changing reproductive effort within a semelparous reproductive episode.

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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.

The role of leptin in nutritional status and reproductive function.

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Keisler, D H; Daniel, J A; Morrison, C D

1999-01-01

Infertility associated with suboptimal nutrition is a major concern among livestock producers. Undernourished prepubertal animals will not enter puberty until they are well fed; similarly, adult, normally cyclic females will stop cycling when faced with extreme undernutrition. Work in our laboratory has focused on how body fat (or adiposity) of an animal can communicate to the brain and regulate reproductive competence. In 1994, the discovery in rodents of the obese (ob) gene product leptin, secreted as a hormone from adipocytes, provided a unique opportunity to understand and hence regulate whole body compositional changes. There is now evidence that similar mechanisms are functioning in livestock species in which food intake, body composition, and reproductive performance are of considerable economic importance. Leptin has been reported to be a potent regulator of food intake and reproduction in rodents. There is evidence indicating that at least some of the effects of leptin occur through receptor-mediated regulation of the hypothalamic protein neuropeptide Y (NPY). NPY is a potent stimulator of food intake, is present at high concentrations in feed-restricted cattle and ewes, and is an inhibitor of LH secretion in these livestock species. In our investigations in sheep, we have cloned a partial cDNA corresponding to the ovine long-form leptin receptor, presumably the only fully active form, and have localized the long-form leptin receptor in the ventromedial and arcuate nuclei of the hypothalamus. Leptin receptor mRNA expression was colocalized with NPY mRNA-containing cell bodies in those regions. We have also determined that hypothalamic leptin receptor expression is greater in feed-restricted ewes than in well-fed ewes. These observations provide a foundation for future investigations into the nutritional modulators of reproduction in livestock.

Comparative analysis of the reproductive strategy of lion's paw scallop Nodipecten subnodosus in Baja California Sur, Mexico

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Marco A Angel-Dapa

2015-07-01

Full Text Available The reproductive strategy of lion's paw scallop Nodipecten subnodosus was evaluated in a culturing system in Bahía Tortugas, Baja California Sur, Mexico during an annual cycle, comparing its response with data previously reported at other localities. High frequencies of ripe gonads throughout the year indicate that reproduction was continuous, with two main ripening/spawning events: July-September and December-March. A continuous breeding is also reported for the species in Bahía Magdalena, Bahía Juncalito, and Bahía de Los Angeles. These eutrophic areas are Biological Active Centers where gametogenesis appears to be regulated by the energy taken from recently ingested food following an opportunistic strategy. However, the digestive gland index decreased and the muscle indices increased during one of the breeding peaks, suggesting that some stored reserves are also used to sustain gametogenesis (conservative strategy partially. High incidences of atretic oocytes are likely associated with atypical daily variations in water temperature from May through September (12 to 33°C, or with stressful conditions in the culturing system in summer. Despite this, the culturing system set in Bahía Tortugas appears beneficial for a continuous reproduction of N. subnodosus.

(Revised The role of melatonin as a hormone and an antioxidant in the control of fish reproduction

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Dr. Saumen Kumar Maitra

2016-05-01

Full Text Available Reproduction in most fish is seasonal or periodic and the spawning occurs in an appropriate season to ensure maximum survival of the offspring. The sequence of reproductive events in an annual cycle is largely under the control of a species-specific endogenous timing system, which essentially relies on a well-equipped physiological response mechanism to changing environmental cues. The duration of solar light or photoperiod is one of the most predictable environmental signals used by a large number of animals including fish to coordinate their seasonal breeding. In vertebrates, the pineal gland is the major photo-neuroendocrine part of the brain that rhythmically synthesizes and releases melatonin (N-acetyl-5-methoxytryptamine into the circulation in synchronization with the environmental light-dark cycle. Past few decades witnessed an enormous progress in understanding the mechanisms by which melatonin regulates seasonal reproduction in fish and in other vertebrates. Most studies emphasized hormonal actions of melatonin through its high-affinity, pertussis toxin-sensitive G-protein (guanine nucleotide binding protein coupled receptors on the hypothalamus-pituitary-gonad (HPG axis of fish. However, the discovery that melatonin due to its lipophilic nature can easily cross the plasma membrane of all cells and may act as a potent scavenger of free radicals and stimulant of different antioxidants added a new dimension to the idea explaining mechanisms of melatonin actions in the regulation of ovarian functions. The basic concept on the actions of melatonin as an antioxidant emerged from mammalian studies. Recently, however, some new studies clearly suggested that melatonin, apart from playing the role of a hormone, may also be associated with the reduction in oxidative stress to augment ovarian functions during spawning. This review thus aims to bring together the current knowledge on the role of melatonin as a hormone as well as an antioxidant in

2014-2017. How medically assisted reproduction changed in Italy. A short comparative synthesis with European countries.

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Malvasi, A; Signore, F; Napoletano, S; Bruti, V; Sestili, C; Di Luca, N M

2017-01-01

More than ten years after law n. 40 of February 19, 2004 became effective, regulation on medically assisted reproduction has dramatically changed outlook. The authors report on the steps that led to these changes through Courts' rulings, the Supreme Court's verdicts and the European Court of Human Rights' decisions, as well as ministerial regulations and guidelines concerning medically assisted reproduction. The aforementioned jurisprudential evolution was set to reach a new balance between the embryo's right to its own dignity and the woman's right to health and freedom of self-determination in reproduction. No court ruling denies that embryos have also to be safeguarded. In fact, there are still numerous prohibitions, including using embryos for experimental purposes. Judges aim primarily at avoiding that embryos' rights overcome the right to parenthood. The authors review the legislation of the various European countries: some have adopted a legislation to regulate medically assisted reproduction, while others have developed in this field some recommendations or guidelines. This is why they call for enactment of a European law governing the implementation/operational methods of medically assisted reproduction in order to avoid the scourge of procreative tourism to countries that have a more permissive law.

A link between hypothyroidism, obesity and male reproduction.

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Aiceles, Veronica; da Fonte Ramos, Cristiane

2016-01-01

Hypothyroidism is a condition in which the serum levels of thyroid hormones are below that necessary to carry out physiological functions in the body. Hypothyroidism is related to obesity as an increase in body weight gain is seen in hypothyroid patients. Moreover, an inverse correlation between free thyroxine values and body mass index has been reported. Leptin, a polypeptide hormone produced by adipocytes, was originally thought to be an antiobesity hormone due its anorexic effects on hypothalamic appetite regulation. However, nowadays it is known that leptin conveys information about the nutritional status to the brain being considered a crucial endocrine factor for regulating several physiological processes including reproduction. Since the identification of thyroid hormone and leptin receptors on the testes, these hormones are being recognized as having important roles in male reproductive functions. A clear link exists among thyroid hormones, leptin and reproduction. Both hormones can negatively affect spermatogenesis and consequently may cause male infertility. The World Health Organization (WHO) estimates the overall prevalence of primary infertility ranging from 8 to 15%. The fact that 30% of couples' inability to conceive is related to a male factor and that the longer hypothyroidism persisted, the greater the damage to the testes, strongly suggest that more studies attempting to clarify both hormones actions directly in the testes need to be conducted specially in cases of congenital hypothyroidism. Therefore, the goal of this review is to highlight the relationship of such hormones in the reproductive system.

Memories of Recent Life Events: Differences in Emotional Reactivity and Regulation of Individuals with High and Low Levels of Depressive Symptoms

DEFF Research Database (Denmark)

del Palacio Gonzalez, Adriana; Watson, Lynn Ann; Berntsen, Dorthe

Existing studies investigating involuntary memories (IMs) in the context of depression extend their hypotheses from PTSD models. Findings suggest that the frequency and suppression of IMs are associated with depression. However, in order to fully understand the memory-mental health relationship......, it is of paramount importance to identify the centrality of events to an individual's identity, and potential differences between IMs and word-cued memories (i.e., voluntary). Method: Participants of this two-staged study were 205 non-clinical adults (Mage = 22.72, SD = 1.99). In Stage 1 participants completed...... questionnaires assessing depressive symptoms, emotion regulation, and recent positive and negative life events. Participants nominated the most and least central events to their identity. Emotion reactivity and regulation of IMs of both events were rated. In Stage 2, participants (n = 48) reporting low and high...

Reproduction in Leishmania: A focus on genetic exchange.

Science.gov (United States)

Rougeron, V; De Meeûs, T; Bañuls, A-L

2017-06-01

One key process of the life cycle of pathogens is their mode of reproduction. Indeed, this fundamental biological process conditions the multiplication and the transmission of genes and thus the propagation of diseases in the environment. Reproductive strategies of protozoan parasites have been a subject of debate for many years, principally due to the difficulty in making direct observations of sexual reproduction (i.e. genetic recombination). Traditionally, these parasites were considered as characterized by a preeminent clonal structure. Nevertheless, with the development of elaborate culture experiments, population genetics and evolutionary and population genomics, several studies suggested that most of these pathogens were also characterized by constitutive genetic recombination events. In this opinion, we focused on Leishmania parasites, pathogens responsible of leishmaniases, a major public health issue. We first discuss the evolutionary advantages of a mixed mating reproductive strategy, then we review the evidence of genetic exchange, and finally we detail available tools to detect naturally occurring genetic recombination in Leishmania parasites and more generally in protozoan parasites. Copyright © 2016. Published by Elsevier B.V.

Insulin-like growth factor-I as a possible hormonal mediator of nutritional regulation of reproduction in cattle.

Science.gov (United States)

Zulu, Victor Chisha; Nakao, Toshihiko; Sawamukai, Yutaka

2002-08-01

The current review aims to establish insulin-like growth factor-1 (IGF-I) as the factor that signals nutritional status to the reproductive axis, and show that assessment of IGF-I in blood early postpartum during the negative energy balance (NEB) period could be used to predict both nutritional and reproductive status in dairy cattle. The review also explores the effect of nutritional status on circulating IGF-I concentrations and the endocrine role of IGF-I on the reproductive axis. IGF-I plays an important role in gonadotropin-induced folliculogenesis, ovarian steroidogenesis and corpus luteum (CL) function. It also modulates pituitary and hypothalamus function. IGF-I clearly has an endocrine role on the reproductive axis. Severe under nutrition significantly reduces plasma IGF-I concentrations. During the critical period of NEB in high yielding dairy cattle early postpartum, IGF-I concentrations are low in blood and its levels are positively correlated to energy status and reproductive function during this period. Changes in circulating IGF-I immediately postpartum may help predict both nutritional and reproductive status in dairy cattle. IGF-I is therefore one of the long sought factors that signal nutritional status to the reproductive axis.

Reproduction in eusocial bees (Apidae: Apini, Meliponini)

NARCIS (Netherlands)

Chinh, T.X.

2004-01-01

This thesis presents some key aspects of the regulation and the mechanisms of colony reproduction in honeybees and stingless bees. Special attention is paid to key questions about how the production of males, gynes and swarms takes place, and what intranidal and extranidal factors are related to

Bovine reproduction in tropical environment

International Nuclear Information System (INIS)

Jimenez Lopez, J.

2001-01-01

In this document it has met relating data to the reproduction of bovine and their handling for the man that it can serve as norms to judge reproductive efficiency but always view in the aspect of the nutritious, climatic circumstances and of handling under which met. Under the previous description one can say that the fertility is the resultant of the interaction among the inheritance, the means and the handling, they vary in particular for each region and property. The fertility can be good, regulate or bad in the measure in that the factors that intervene. The environmental effect on the reproductive processes of the cow represents 80 percent of the variation factors and they include climate, effect of the light, effect of the temperature, effect of the nutritious contribution, effect of psychological factors: the loss of the tendency to the seasonal reproduction is in fact an answer from the animals to its association with the man. The influence of the environment and the feeding of the animals are more intense in the females than in the males, being evidenced that the reproduction control is under the influence hormonal joint with the nutrition. An appropriate nutrition is prerequisite for the beginning of the sexual maturation with an appropriate weight and corporal condition. It is also described the effect and the relationship of the energy contribution about the fertility, the restart of the ovarian activity, its cause of the continuation of the interval childbirth-conception, silent ovulation, organic ancestry and interval among childbirths

Genome-wide identification of physically clustered genes suggests chromatin-level co-regulation in male reproductive development in Arabidopsis thaliana.

Science.gov (United States)

Reimegård, Johan; Kundu, Snehangshu; Pendle, Ali; Irish, Vivian F; Shaw, Peter; Nakayama, Naomi; Sundström, Jens F; Emanuelsson, Olof

2017-04-07

Co-expression of physically linked genes occurs surprisingly frequently in eukaryotes. Such chromosomal clustering may confer a selective advantage as it enables coordinated gene regulation at the chromatin level. We studied the chromosomal organization of genes involved in male reproductive development in Arabidopsis thaliana. We developed an in-silico tool to identify physical clusters of co-regulated genes from gene expression data. We identified 17 clusters (96 genes) involved in stamen development and acting downstream of the transcriptional activator MS1 (MALE STERILITY 1), which contains a PHD domain associated with chromatin re-organization. The clusters exhibited little gene homology or promoter element similarity, and largely overlapped with reported repressive histone marks. Experiments on a subset of the clusters suggested a link between expression activation and chromatin conformation: qRT-PCR and mRNA in situ hybridization showed that the clustered genes were up-regulated within 48 h after MS1 induction; out of 14 chromatin-remodeling mutants studied, expression of clustered genes was consistently down-regulated only in hta9/hta11, previously associated with metabolic cluster activation; DNA fluorescence in situ hybridization confirmed that transcriptional activation of the clustered genes was correlated with open chromatin conformation. Stamen development thus appears to involve transcriptional activation of physically clustered genes through chromatin de-condensation. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

REPRODUCTIVE SEASONALITY AND ITS CONTROL IN SPANISH SHEEP AND GOATS

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Amelia Gómez Brunet

2011-12-01

Full Text Available Sheep and goat breeds from subtropical, middle and high latitudes show seasonal changes in reproductive activity. In general, the breeding season starts in autumn and ends in winter, with anoestrus in spring/summer. An endogenous circannual rhythm driven and synchronised by the annual photoperiod cycle regulates the onset and offset of the breeding season. However, the timing and duration of the breeding season can be affected by interactions between the photoperiod and factors such as breed, geographical origin, nutritional and lactational status, social interactions, and the season of parturition. Seasonality in reproduction is naturally accompanied by variation in the availability and price of meat, milk and cheese over the year, affecting the economy of farmers, consumers and the food industry alike. The control of reproduction outside the normal breeding season by inducing and synchronizing oestrus and ovulation plus the use of artificial insemination and/or natural mating would help ensure the year-round availability of products. This review describes the seasonal variation in the sexual activity of ovine and caprine species with special regard to local Spanish sheep and goats breeds, examines how the photoperiod regulates their annual reproductive cycle, and discusses a number of strategies that can be used to induce and synchronise ovulation outside the natural breeding season.

Involving men in reproductive health: making the mandate a reality.

Science.gov (United States)

Ndong, I; Steele, C; Mahony, E

1998-01-01

When men are provided with information about reproductive health issues, they are more likely to support their partners' family planning decisions. Such support is particularly important in cultures where women are unable to negotiate sexual relationships, and may therefore be exposing themselves to sexually transmitted diseases (STDs) and unwanted pregnancies. Good communication between partners ensures that women receive the reproductive health care they need. AVSC International developed the Men As Partners (MAP) initiative with the goals of increasing men's awareness and support of their partners' reproductive health choices; men's awareness of the need to safeguard reproductive health, especially through the prevention of STDs; and the use of contraceptive methods which require the participation and cooperation of men among couples who want to use them. In May 1997, AVSC organized the first-ever interregional workshop on men's involvement in reproductive health. More than 150 participants from 5 continents attended the event in Mombasa, Kenya, where they discussed ways to involve men in the health of their female partners. Main workshop themes were gender issues, reproductive health services for men, community outreach and workplace programs, access to services, and adolescents.

76 FR 52263 - Special Local Regulation for Marine Events; Mattaponi Madness Drag Boat Race, Mattaponi River...

Science.gov (United States)

2011-08-22

... hour, make special local regulations necessary. However, the Coast Guard will provide advance... dangers posed by drag boat racing, operating in speeds excess of 150 miles per hour, make special local... side activities in the event area. The category of water activities includes but is not limited to sail...

Roles of autophagy in male reproductive development in plants

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Shigeru eHanamata

2014-09-01

Full Text Available Autophagy, a major catabolic pathway in eukaryotic cells, is essential in development, maintenance of cellular homeostasis, immunity and programmed cell death (PCD in multicellular organisms. In plant cells, autophagy plays roles in recycling of proteins and metabolites including lipids, and is involved in many physiological processes such as abiotic and biotic stress responses. However, its roles during reproductive development had remained poorly understood. Quantitative live cell imaging techniques for the autophagic flux and genetic studies in several plant species have recently revealed significant roles of autophagy in developmental processes, regulation of PCD and lipid metabolism. We here review the novel roles of autophagic fluxes in plant cells, and discuss their possible significance in PCD and metabolic regulation, with particular focus on male reproductive development during the pollen maturation.

Provision of assisted reproductive technology for single women in China: a new challenge.

Science.gov (United States)

Zhou, Ling Jing

2004-01-01

Following the enactment of the Jilin Regulation, single women, for the first time, are allowed to access assisted reproductive services in China. This paper is intended to analyze the arguments over whether single women are entitled to access assisted reproductive services, in relation to Chinese legal, ethical and social characteristics.

Reproductive rights approach to reproductive health in developing countries

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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.

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.

Growth and reproduction respond differently to climate in three Neotropical tree species.

Science.gov (United States)

Alfaro-Sánchez, Raquel; Muller-Landau, Helene C; Wright, S Joseph; Camarero, J Julio

2017-06-01

The response of tropical forests to anthropogenic climate change is critically important to future global carbon budgets, yet remains highly uncertain. Here, we investigate how precipitation, temperature, solar radiation and dry- and wet-season lengths are related to annual tree growth, flower production, and fruit production in three moist tropical forest tree species using long-term datasets from tree rings and litter traps in central Panama. We also evaluated how growth, flower, and fruit production were interrelated. We found that growth was positively correlated with wet-season precipitation in all three species: Jacaranda copaia (r = 0.63), Tetragastris panamensis (r = 0.39) and Trichilia tuberculata (r = 0.39). Flowering and fruiting in Jacaranda were negatively related to current-year dry-season rainfall and positively related to prior-year dry-season rainfall. Flowering in Tetragastris was negatively related to current-year annual mean temperature while Trichilia showed no significant relationships of reproduction with climate. Growth was significantly related to reproduction only in Tetragastris, where it was positively related to previous year fruiting. Our results suggest that tree growth in moist tropical forest tree species is generally reduced by drought events such as those associated with strong El Niño events. In contrast, interannual variation in reproduction is not generally associated with growth and has distinct and species-specific climate responses, with positive effects of El Niño events in some species. Understanding these contrasting climate effects on tree growth and reproduction is critical to predicting changes in tropical forest dynamics and species composition under climate change.

Reproductive neuroendocrine pathways of social behavior

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Ishwar eParhar

2016-03-01

Full Text Available Social behaviors are key components of reproduction because they are essential for successful fertilization. Social behaviors such as courtship, mating, and aggression are strongly associated with sex steroids, such as testosterone, estradiol and progesterone. Secretion of sex steroids from the gonads is regulated by the hypothalamus-pituitary-gonadal (HPG axis in vertebrates. Gonadotropin-releasing hormone (GnRH is a pivotal hypothalamic neuropeptide that stimulates gonadotropin release from the pituitary. In recent years, the role of neuropeptides containing the C-terminal Arg-Phe-NH2 (RFamide peptides has been emphasized in vertebrate reproduction. In particular, two key RFamide peptides, kisspeptin and gonadotropin-inhibitory hormone (GnIH, emerged as critical accelerator and suppressor of gonadotropin secretion. Kisspeptin stimulates GnRH release by directly acting on GnRH neurons, whereas GnIH inhibits gonadotropin release by inhibiting kisspeptin or GnRH neurons or pituitary gonadotropes. These neuropeptides can regulate social behavior by regulating the HPG axis. However, distribution of neuronal fibers of GnRH, kisspeptin and GnIH neurons are not limited within the hypothalamus, and the existence of extra-hypothalamic neuronal fibers suggests direct control of social behavior within the brain. It has traditionally been shown that central administration of GnRH can stimulate female sexual behavior in rats. Recently, it was shown that Kiss1, one of the paralogs of kisspeptin peptide family, regulates fear responses in zebrafish and GnIH inhibits socio-sexual behavior in birds. Here we highlight recent findings regarding the role of GnRH, kisspeptin and GnIH in the regulation of social behaviors in fish, birds and mammals and discuss their importance in future biological and biomedical research.

Reproductive cloning in humans and therapeutic cloning in primates: is the ethical debate catching up with the recent scientific advances?

Science.gov (United States)

Camporesi, S; Bortolotti, L

2008-09-01

After years of failure, in November 2007 primate embryonic stem cells were derived by somatic cellular nuclear transfer, also known as therapeutic cloning. The first embryo transfer for human reproductive cloning purposes was also attempted in 2006, albeit with negative results. These two events force us to think carefully about the possibility of human cloning which is now much closer to becoming a reality. In this paper we tackle this issue from two sides, first summarising what scientists have achieved so far, then discussing some of the ethical arguments in favour and against human cloning which are debated in the context of policy making and public consultation. Therapeutic cloning as a means to improve and save lives has uncontroversial moral value. As to human reproductive cloning, we consider and assess some common objections and failing to see them as conclusive. We do recognise, though, that there will be problems at the level of policy and regulation that might either impair the implementation of human reproductive cloning or make its accessibility restricted in a way that could become difficult to justify on moral grounds. We suggest using the time still available before human reproductive cloning is attempted successfully to create policies and institutions that can offer clear directives on its legitimate applications on the basis of solid arguments, coherent moral principles, and extensive public consultation.

Toward a gender-sensitive assisted reproduction policy.

Science.gov (United States)

Donchin, Anne

2009-01-01

The recent case of the UK woman who lost her legal struggle to be impregnated with her own frozen embryos, raises critical issues about the meaning of reproductive autonomy and the scope of regulatory practices. I revisit this case within the context of contemporary debate about the moral and legal dimensions of assisted reproduction. I argue that the gender neutral context that frames discussion of regulatory practices is unjust unless it gives appropriate consideration to the different positions women and men occupy in relation to reproductive processes and their options for autonomous choice. First, I consider relevant legal rulings, media debate, and scholarly commentary. Then I discuss the concept of reproductive autonomy imbedded in this debate. I argue that this concept conflates informed consent and reproductive autonomy, thereby providing an excessively narrow reading of autonomy that fails to give due regard to relations among individuals or the social, political and economic environment that shapes their options. I contrast this notion of autonomy with feminist formulations that seek to preserve respect for the agency of individuals without severing them from the conditions of their embodiment, their surrounding social relationships, or the political contexts that shape their options. Taking these considerations into account I weigh the advantages of regulation over the commercial market arrangement that prevails in some countries and suggest general guidelines for a regulatory policy that would more equitably resolve conflicting claims to reproductive autonomy.

Environmental Hexachlorobenzene exposure and human male reproductive function

DEFF Research Database (Denmark)

Specht, Ina Olmer; Bonde, Jens Peter Ellekilde; Toft, Gunnar

2015-01-01

Hexachlorobenzene (HCB) is a persistent environmental fungicide that may disrupt androgen regulation. The aim of this study was to investigate associations between HCB levels and biomarkers of male reproductive function. 589 Spouses of pregnant women from Greenland, Poland and Ukraine were enroll...

The special programme of research in human reproduction: forty years of activities to achieve reproductive health for all.

Science.gov (United States)

Benagiano, Giuseppe; d'Arcangues, Catherine; Harris Requejo, Jennifer; Schafer, Alessandra; Say, Lale; Merialdi, Mario

2012-01-01

The Special Programme of Research in Human Reproduction (HRP), co-sponsored by the UNDP, UNFPA, WHO, and the World Bank, is celebrating 40 years of activities with an expansion of its mandate and new co-sponsors. When it began, in 1972, the main focus was on evaluating the acceptability, effectiveness, and safety of existing fertility-regulating methods, as well as developing new, improved modalities for family planning. In 1994, HRP not only made major contributions to the Plan of Action of the International Conference on Population and Development (ICPD); it also broadened its scope of work to include other aspects of health dealing with sexuality and reproduction, adding a specific perspective on gender issues and human rights. In 2002, HRP's mandate was once again broadened to include sexually transmitted infections and HIV/AIDS and in 2003 it was further expanded to research activities on preventing violence against women and its many dire health consequences. Today, the work of the Programme includes research on: the sexual and reproductive health of adolescents, women, and men; maternal and perinatal health; reproductive tract and sexually transmitted infections (including HIV/AIDS); family planning; infertility; unsafe abortion; sexual health; screening for cancer of the cervix in developing countries, and gender and reproductive rights. Additional activities by the Programme have included: fostering international cooperation in the field of human reproduction; the elaboration of WHO's first Global Reproductive Health Strategy; work leading to the inclusion of ICPD's goal 'reproductive health for all by 2015' into the Millennium Development Goal framework; the promotion of critical interagency statements on the public health, legal, and human rights implications of female genital mutilation and gender-biased sex selection. Finally, HRP has been involved in the creation of guidelines and tools, such as the 'Medical eligibility criteria for contraceptive use

Responsiveness of pituitary to galanin throughout the reproductive cycle of male European sea bass (Dicentrarchus labrax).

Science.gov (United States)

Pinto, P; Velez, Z; Sousa, C; Santos, S; Andrade, A; Alvarado, M V; Felip, A; Zanuy, S; Canário, A V M

2017-09-01

The neuropeptide galanin (Gal) is a putative factor regulating puberty onset and reproduction through its actions on the pituitary. The present study investigated the pituitary responsiveness to galanin and the patterns of galanin receptors (Galrs) expression throughout the reproductive cycle of two years old male European sea bass (Dicentrarchus labrax), an important aquaculture species. Quantitative analysis of pituitary and hypothalamus transcript expression of four galr subtypes revealed differential regulation according to the testicular developmental stage, with an overall decrease in expression from the immature stage to the mid-recrudescence stage. Incubation of pituitary cells with mammalian 1-29Gal peptide induced significant changes in cAMP concentration, with sensitivities that varied according to the testicular development stages. Furthermore 1-29Gal was able to stimulate both follicle stimulating hormone (Fsh) and luteinizing hormone (Lh) release from pituitary cell suspensions. The magnitude of the effects and effective concentrations varied according to reproductive stage, with generalized induction of Fsh and Lh release in animals sampled in January (full spermiation). The differential expression of galrs in pituitary and hypothalamus across the reproductive season, together with the differential effects of Gal on gonadotropins release in vitro strongly suggests the involvement of the galaninergic system in the regulation the hypothalamus-pituitary-gonad axis of male sea bass. This is to our knowledge the first clear evidence for the involvement of galanin in the regulation of reproduction in non-mammalian vertebrates. Copyright © 2017 Elsevier Inc. All rights reserved.

Ethics and regulation of inter-country medically assisted reproduction: a call for action.

Science.gov (United States)

Shalev, Carmel; Moreno, Adi; Eyal, Hedva; Leibel, Michal; Schuz, Rhona; Eldar-Geva, Talia

2016-01-01

The proliferation of medically assisted reproduction (MAR) for the treatment of infertility has brought benefit to many individuals around the world. But infertility and its treatment continue to be a cause of suffering, and over the past decade, there has been a steady growth in a new global market of inter-country medically assisted reproduction (IMAR) involving 'third-party' individuals acting as surrogate mothers and gamete donors in reproductive collaborations for the benefit of other individuals and couples who wish to have children. At the same time there is evidence of a double standard of care for third-party women involved in IMAR, violations of human rights of children and women, and extreme abuses that are tantamount to reproductive trafficking. This paper is the report of an inter-disciplinary working group of experts who convened in Israel to discuss the complex issues of IMAR. In Israel too IMAR practices have grown rapidly in recent years, mainly because of restrictions on access to domestic surrogacy for same sex couples and a chronically insufficient supply of egg cells for the treatment of couples and singles in need. Drawing upon local expertise, the paper describes documented practices that are harmful, suggests principles of good practice based on an ethic of care, and calls for action at the international, national and professional levels to establish a human rights based system of international governance for IMAR based on three regulatory models: public health monitoring, inter-country adoption, and trafficking in human beings, organs and tissues.

The regulation of cellular apoptosis by the ROS-triggered PERK/EIF2α/chop pathway plays a vital role in bisphenol A-induced male reproductive toxicity

Energy Technology Data Exchange (ETDEWEB)

Yin, Li [Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing 400038 (China); Dai, Yanlin [Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing 400038 (China); Medical Laboratory Technology Department, Chuxiong Medical College, Yunnan 675005 (China); Cui, Zhihong; Jiang, Xiao; Liu, Wenbin; Han, Fei; Lin, Ao; Cao, Jia [Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing 400038 (China); Liu, Jinyi, E-mail: jinyiliutmmu@163.com [Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing 400038 (China)

2017-01-01

Bisphenol A (2,2-bis(4-hydroxyphenyl)propane, BPA) is ubiquitous in the environment, wildlife, and humans. Evidence from past studies suggests that BPA is associated with decreased semen quality. However, the molecular basis for the adverse effect of BPA on male reproductive toxicity remains unclear. We evaluated the effect of BPA on mouse spermatocytes GC-2 cells and adult mice, and we explored the potential mechanism of its action. The results showed that BPA inhibited cell proliferation and increased the apoptosis rate. The testes from BPA-treated mice showed fewer spermatogenic cells and sperm in the seminiferous tubules. In addition, BPA caused reactive oxygen species (ROS) accumulation. Previous study has verified that mitochondrion was the organelle affected by the BPA-triggered ROS accumulation. We found that BPA induced damage to the endoplasmic reticulum (ER) in addition to mitochondria, and most ER stress-related proteins were activated in cellular and animal models. Knocking down of the PERK/EIF2α/chop pathway, one of the ER stress pathways, partially recovered the BPA-induced cell apoptosis. In addition, an ROS scavenger attenuated the expression of the PERK/EIF2α/chop pathway-related proteins. Taken together, these data suggested that the ROS regulated PERK/EIF2α/chop pathway played a vital role in BPA-induced male reproductive toxicity. - Highlights: • BPA exposure caused the damage of the endoplasmic reticulum. • BPA exposure activated ER stress related proteins in male reproductive system. • ROS regulated PERK/EIF2α/chop pathway played a vital role in BPA-induced toxicity.

Mutations and polymorphisms in FSH receptor: functional implications in human reproduction.

Science.gov (United States)

Desai, Swapna S; Roy, Binita Sur; Mahale, Smita D

2013-12-01

FSH brings about its physiological actions by activating a specific receptor located on target cells. Normal functioning of the FSH receptor (FSHR) is crucial for follicular development and estradiol production in females and for the regulation of Sertoli cell function and spermatogenesis in males. In the last two decades, the number of inactivating and activating mutations, single nucleotide polymorphisms, and spliced variants of FSHR gene has been identified in selected infertile cases. Information on genotype-phenotype correlation and in vitro functional characterization of the mutants has helped in understanding the possible genetic cause for female infertility in affected individuals. The information is also being used to dissect various extracellular and intracellular events involved in hormone-receptor interaction by studying the differences in the properties of the mutant receptor when compared with WT receptor. Studies on polymorphisms in the FSHR gene have shown variability in clinical outcome among women treated with FSH. These observations are being explored to develop molecular markers to predict the optimum dose of FSH required for controlled ovarian hyperstimulation. Pharmacogenetics is an emerging field in this area that aims at designing individual treatment protocols for reproductive abnormalities based on FSHR gene polymorphisms. The present review discusses the current knowledge of various genetic alterations in FSHR and their impact on receptor function in the female reproductive system.

Effect of tree logging on reproductive performance in Blue Tits (Cyanistes caeruleus)

OpenAIRE

Amininasab, Seyed Mehdi; Xu, Charles C. Y.; Kingma, Sjouke A.; Komdeur, Jan

2017-01-01

For birds, habitat quality is largely determined by local vegetation, and reproductive performance can therefore be negatively influenced by anthropogenic activities. A tree logging event enabled us to examine the effect of removing trees of different maturities and types on the reproductive performance of Blue Tits (Cyanistes caeruleus). Against expectations, only the logging of small coniferous trees, but not larger and deciduous trees, was associated with a reduction in the number of eggs ...

Effects of melatonin and prolactin in reproduction: review of literature

OpenAIRE

Tenorio, Fernanda das Chagas Angelo Mendes; Simões, Manuel de Jesus; Teixeira, Valéria Wanderley; Teixeira, Álvaro Aguiar Coelho

2015-01-01

Summary The pineal gland is responsible for producing a hormone called melatonin (MEL), and is accepted as the gland that regulates reproduction in mammals. Prolactin (PRL) also exhibits reproductive activity in animals in response to photoperiod. It is known that the concentrations of PRL are high in the summer and reduced during winter, the opposite of what is seen with melatonin in these seasons. In placental mammals, both prolactin and melatonin affect implantation, which is considered a ...

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...

Effects of dietary omega-3/omega-6 fatty acid ratios on reproduction in the young breeder rooster.

Science.gov (United States)

Feng, Yun; Ding, Yu; Liu, Juan; Tian, Ye; Yang, Yanzhou; Guan, Shuluan; Zhang, Cheng

2015-03-21

Polyunsaturated fatty acids (PUFAs) are necessary for the body's metabolism, growth and development. Although PUFAs play an important role in the regulation of reproduction, their role in testis development in the rooster is unknown. The present study was conducted to investigate the effects of omega-3/omega-6 (n-3/n-6, PUFAs) ratios on reproductive performance in young breeder roosters. Plasma levels of reproductive hormones, testis development, and reproductive hormone receptor and StAR mRNA expression were also assessed. Although PUFAs (n-3/n-6: 1/4.15) had no significant effect on the testis index (P > 0.05), the spermatogonial development and germ cell layers were increased. Moreover, serum levels of hormones (GnRH, FSH, LH and T) on day 35 were also significantly increased by PUFAs (n-3/n-6: 1/4.15). To investigate whether PUFAs regulate the expression of hormone receptors and StAR, real time-PCR was used to measure GnRHR, FSHR, LHR and StAR mRNA levels. PUFAs significantly increased the mRNA levels of all of these genes. These results indicate that PUFAs enhance the reproductive performance of young roosters by increasing hormone secretion and function, the latter by up-regulating receptor expression. These findings provide a sound basis for a balanced n-3/n-6 PUFA ratio being beneficial to young rooster reproduction.

Events and mega events: leisure and business in tourism

Directory of Open Access Journals (Sweden)

Ricardo Alexandre Paiva

2015-12-01

Full Text Available The promotion of events and mega events mobilizes at the same time, in a concatenated way or not, leisure and business practices, which are captured by the tourism industry as a stimulus for the reproduction of capitalism, by the amount of other activities which raise (primary, secondary and tertiary , placing the architecture and the city as protagonists in contemporary urban development. In this sense, the article analyzes the articulation of events and mega events to the provision of architecture and urban infrastructure, as well as the construction of the tourist image of the places, motivated by leisure and business activities. The methodological procedures have theoretical and exploratory character and have multidisciplinary intentions. This will be discussed, in a historical perspective, the concepts of leisure and business activities that raise as moving or traveling; next it will be delimited similarities and differences between tourism events and business tourism, entering after the analysis of the distinctions between events and mega events, highlighting the complexity and the role of mega-events as a major symptom of globalization; finally it will be presented the spatial scale developments in architecture and the city in the realization of (mega events, as well as its impact on the city's image. As a synthesis, it is important to notice that spatial developments business tourism, events and mega events are manifested in various scales and with different levels of complexity, revealing the strengths and / or weaknesses of the places. The urban planning, architecture and urbanism are important objects of knowledge and spatial intervention to ensure infrastructure and urban and architectural structures appropriate for events, which should be sensitive to the demands of tourists and host communities.

Reproduction of the shorthorn sculpin Myoxocephalus scorpius in northern Norway

NARCIS (Netherlands)

Luksenburg, JA; Pedersen, T; Falk-Petersen, IB

The reproduction and life history events of the shorthorn sculpin Myoxocephalus scorpius were studied in an unexploited high latitude population in Tromso, northern Norway. Shorthorn sculpins were sampled from November 1998 to March 1999 to determine sex ratio, spawning period, oogenesis, fecundity,

Visual communication stimulates reproduction in Nile tilapia, Oreochromis niloticus (L.).

Science.gov (United States)

Castro, A L S; Gonçalves-de-Freitas, E; Volpato, G L; Oliveira, C

2009-04-01

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 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.

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...

Reproductive Rights and Women’s Freedom. Remarks on the Feminist Debate

Directory of Open Access Journals (Sweden)

Isabel Fanlo Cortés

2017-07-01

Full Text Available This article seeks to contribute to the issue of reproductive rights, assuming for the analysis the perspective of the contemporary Western feminist debate. Notwithstanding the variety of approaches and positions that find expression in the scope of such a debate, emphasis is given to the convergent interest of the most recent feminist bioethical discussion in the subject of legal regulation that the States predict, both in relation to the use of certain Reproductive technologies, and the exercise of other reproductive rights, as well as the value premises that underpin these policies and their effects on the lives of women. Finally, in the light of the recent transformations of the modalities of public control over reproductive choices, some challenges will be identified that fall on contemporary feminisms.

75 FR 16009 - Drawbridge Operation Regulations; Acushnet River, New Bedford and Fairhaven, MA, Event-Road Race

Science.gov (United States)

2010-03-31

... Operation Regulations; Acushnet River, New Bedford and Fairhaven, MA, Event--Road Race AGENCY: Coast Guard... Community Health Center 5K Road Race, by allowing the bridge to remain in the closed position for two hours during the running of the 5K Road Race. DATES: This deviation is effective from 10 a.m. through 12 p.m...

Roles of RFRP-3 in the daily and seasonal regulation of reproductive activity in female Syrian hamsters

DEFF Research Database (Denmark)

Henningsen, Jo B.; Ancel, Caroline; Mikkelsen, Jens D.

2017-01-01

In females, reproductive activity relies on proper integration of daily and environmental changes as well as cyclic sex-steroid feedback. This study sought to investigate the role of the hypothalamic Arg-Phe amide-related peptide (RFRP)-3 in the daily and seasonal control of reproductive activity...... alongside kisspeptin neurons, are essential for proper synchronization of reproductive activity with the time of the day, the stage of the estrous cycle, and the seasonal changes in photoperiod....

Similarities between Reproductive and Immune Pistil Transcriptomes of Arabidopsis Species.

Science.gov (United States)

Mondragón-Palomino, Mariana; John-Arputharaj, Ajay; Pallmann, Maria; Dresselhaus, Thomas

2017-07-01

Independent lines of evidence suggest that members from ancient and polymorphic gene families such as defensins and receptor-like kinases mediate intercellular communication during both the immune response and reproduction. Here, we report a large-scale analysis to investigate the extent of overlap between these processes by comparing differentially expressed genes (DEGs) in the pistil transcriptomes of Arabidopsis thaliana and Arabidopsis halleri during self-pollination and interspecific pollination and during infection with Fusarium graminearum In both Arabidopsis species, the largest number of DEGs was identified in infected pistils, where genes encoding regulators of cell division and development were most frequently down-regulated. Comparison of DEGs between infection and various pollination conditions showed that up to 79% of down-regulated genes are shared between conditions and include especially defensin-like genes. Interspecific pollination of A. thaliana significantly up-regulated thionins and defensins. The significant overrepresentation of similar groups of DEGs in the transcriptomes of reproductive and immune responses of the pistil makes it a prime system in which to study the consequences of plant-pathogen interactions on fertility and the evolution of intercellular communication in pollination. © 2017 American Society of Plant Biologists. All Rights Reserved.

AGAMOUS controls GIANT KILLER, a multifunctional chromatin modifier in reproductive organ patterning and differentiation.

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Kian-Hong Ng

2009-11-01

Full Text Available The Arabidopsis homeotic protein AGAMOUS (AG, a MADS domain transcription factor, specifies reproductive organ identity during flower development. Using a binding assay and expression analysis, we identified a direct target of AG, GIANT KILLER (GIK, which fine-tunes the expression of multiple genes downstream of AG. The GIK protein contains an AT-hook DNA binding motif that is widely found in chromosomal proteins and that binds to nuclear matrix attachment regions of DNA elements. Overexpression and loss of function of GIK cause wide-ranging defects in patterning and differentiation of reproductive organs. GIK directly regulates the expression of several key transcriptional regulators, including ETTIN/AUXIN RESPONSE FACTOR 3 (ETT/ARF3 that patterns the gynoecium, by binding to the matrix attachment regions of target promoters. Overexpression of GIK causes a swift and dynamic change in repressive histone modification in the ETT promoter. We propose that GIK acts as a molecular node downstream of the homeotic protein AG, regulating patterning and differentiation of reproductive organs through chromatin organization.

Data logging of body temperatures provides precise information on phenology of reproductive events in a free-living arctic hibernator

Science.gov (United States)

Williams, C.T.; Sheriff, M.J.; Schmutz, J.A.; Kohl, F.; Toien, O.; Buck, C.L.; Barnes, B.M.

2011-01-01

Precise measures of phenology are critical to understanding how animals organize their annual cycles and how individuals and populations respond to climate-induced changes in physical and ecological stressors. We show that patterns of core body temperature (T b) can be used to precisely determine the timing of key seasonal events including hibernation, mating and parturition, and immergence and emergence from the hibernacula in free-living arctic ground squirrels (Urocitellus parryii). Using temperature loggers that recorded T b every 20 min for up to 18 months, we monitored core T b from three females that subsequently gave birth in captivity and from 66 female and 57 male ground squirrels free-living in the northern foothills of the Brooks Range Alaska. In addition, dates of emergence from hibernation were visually confirmed for four free-living male squirrels. Average T b in captive females decreased by 0.5–1.0°C during gestation and abruptly increased by 1–1.5°C on the day of parturition. In free-living females, similar shifts in T b were observed in 78% (n = 9) of yearlings and 94% (n = 31) of adults; females without the shift are assumed not to have given birth. Three of four ground squirrels for which dates of emergence from hibernation were visually confirmed did not exhibit obvious diurnal rhythms in T b until they first emerged onto the surface when T b patterns became diurnal. In free-living males undergoing reproductive maturation, this pre-emergence euthermic interval averaged 20.4 days (n = 56). T b-loggers represent a cost-effective and logistically feasible method to precisely investigate the phenology of reproduction and hibernation in ground squirrels.

Neuroendocrine regulation of gonadotropin secretion in seasonally breeding birds

Directory of Open Access Journals (Sweden)

Takayoshi eUbuka

2013-03-01

Full Text Available Seasonally breeding birds detect environmental signals, such as light, temperature, food availability and presence of mates to time reproduction. Hypothalamic neurons integrate external and internal signals, and regulate reproduction by releasing neurohormones to the pituitary gland. The pituitary gland synthesizes and releases gonadotropins which in turn act on the gonads to stimulate gametogenesis and sex steroid secretion. Accordingly, how gonadotropin secretion is controlled by the hypothalamus is key to our understanding of the mechanisms of seasonal reproduction. A hypothalamic neuropeptide, gonadotropin-releasing hormone (GnRH, activates reproduction by stimulating gonadotropin synthesis and release. Another hypothalamic neuropeptide, gonadotropin-inhibitory hormone (GnIH, inhibits gonadotropin synthesis and release directly by acting on the pituitary gland or indirectly by decreasing the activity of GnRH neurons. Therefore, the next step to understand seasonal reproduction is to investigate how the activities of GnRH and GnIH neurons in the hypothalamus and their receptors in the pituitary gland are regulated by external and internal signals. It is possible that locally-produced triiodothyronine resulting from the action of type 2 iodothyronine deiodinase on thyroxine stimulates the release of gonadotropins, perhaps by action on GnRH neurons. The function of GnRH neurons is also regulated by transcription of the GnRH gene. Melatonin, a nocturnal hormone, stimulates the synthesis and release of GnIH and GnIH may therefore regulate a daily rhythm of gonadotropin secretion. GnIH may also temporally suppress gonadotropin secretion when environmental conditions are unfavorable. Environmental and social milieus fluctuate seasonally in the wild. Accordingly, complex interactions of various neuronal and hormonal systems need to be considered if we are to understand the mechanisms underlying seasonal reproduction.

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...

Condition-dependent chemosignals in reproductive behavior of lizards.

Science.gov (United States)

Martín, José; López, Pilar

2015-02-01

This article is part of a Special Issue "Chemosignals and Reproduction". Many lizards have diverse glands that produce chemosignals used in intraspecific communication and that can have reproductive consequences. For example, information in chemosignals of male lizards can be used in intrasexual competition to identify and assess the fighting potential or dominance status of rival males either indirectly through territorial scent-marks or during agonistic encounters. Moreover, females of several lizard species "prefer" to establish or spend more time on areas scent-marked by males with compounds signaling a better health or body condition or a higher genetic compatibility, which can have consequences for their mating success and inter-sexual selection processes. We review here recent studies that suggest that the information content of chemosignals of lizards may be reliable because several physiological and endocrine processes would regulate the proportions of chemical compounds available for gland secretions. Because chemosignals are produced by the organism or come from the diet, they should reflect physiological changes, such as different hormonal levels (e.g. testosterone or corticosterone) or different health states (e.g. parasitic infections, immune response), and reflect the quality of the diet of an individual. More importantly, some compounds that may function as chemosignals also have other important functions in the organism (e.g. as antioxidants or regulating the immune system), so there could be trade-offs between allocating these compounds to attending physiological needs or to produce costly sexual "chemical ornaments". All these factors may contribute to maintain chemosignals as condition-dependent sexual signals, which can inform conspecifics on the characteristics and state of the sender and allow making behavioral decisions with reproductive consequences. To understand the evolution of chemical secretions of lizards as sexual signals and their

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....

Stress and its influence on reproduction in pigs: a review

Directory of Open Access Journals (Sweden)

Madej Andrzej

2008-12-01

Full Text Available Abstract The manifestations of stress, defined as a biological response to an event that the individual perceives as a threat to its homeostasis, are commonly linked to enhanced activity of the hypothalamo-pituitary-adrenal (HPA axis and the activation of the sympathetic adreno-medullary (SA system. Activation of the HPA system results in the secretion of peptides from the hypothalamus, principally corticotropin releasing hormone (CRH, which stimulates the release of adrenocorticotropic hormone (ACTH and beta-endorphin. ACTH induces the secretion of corticosteroids from the adrenal cortex, which can be seen in pigs exposed to acute physical and/or psychological stressors. The present paper is a review of studies on the influence of stressors on reproduction in pigs. The effects of stress on reproduction depend on the critical timing of stress, the genetic predisposition to stress, and the type of stress. The effect of stress on reproduction is also influenced by the duration of the responses induced by various stressors. Prolonged or chronic stress usually results in inhibition of reproduction, while the effects of transient or acute stress in certain cases is stimulatory (e.g. anoestrus, but in most cases is of impairment for reproduction. Most sensitive of the reproductive process are ovulation, expression of sexual behaviour and implantation of the embryo, since they are directly controlled by the neuroendocrine system.

RFRP neurons are critical gatekeepers for the photoperiodic control of reproduction

Directory of Open Access Journals (Sweden)

Valerie eSimonneaux

2012-12-01

Full Text Available Seasonally-breeding mammals rely on the photoperiodic signal to restrict their fertility to a certain time of the year. The photoperiodic information is translated in the brain via the pineal hormone melatonin, and it is now well established that it is the variation in the duration of the nocturnal peak of melatonin which synchronises reproduction with the seasons. The Syrian hamster is a long day breeder, and sexual activity is therefore promoted by exposure to a long day photoperiod and inhibited by exposure to a short day photoperiod. Interestingly, in this species electrolytic lesion of the mediobasal hypothalamus abolishes the short day-induced gonadal regression. We have shown that the expression of a recently discovered neuronal population, namely RFamide-related peptide (rfrp neurons, present in the mediobasal hypothalamus, is strongly down-regulated by melatonin in short day conditions, but not altered by circulating levels of sex steroids. The role of rfrp and its product RFRP-3 in the regulation of reproductive activity has been extensively studied in mammals, and our recent findings indicate that this peptide is a potent stimulator of the reproductive axis in the Syrian hamster. It induces a marked increase in GnRH neuron activity and gonadotrophin secretion, and it is able to rescue reproductive activity in short day sexually inactive hamsters. Little is known about the localisation of the RFRP-3 receptor, GPR147, in the rodent brain. Accumulating evidence suggests that RFRP-3 could be acting via two intermediates, the GnRH neurons in the preoptic area and the Kiss1 neurons in the arcuate nucleus, but future studies should aim at describing the localisation of Gpr147 in the Syrian hamster brain. Altogether our data indicate that the rfrp neuronal population within the mediobasal hypothalamus might be a serious candidate in mediating the photoperiodic effects of melatonin on the regulation of the reproductive axis.

Molecular characterization of kiss2 and differential regulation of reproduction-related genes by sex steroids in the hypothalamus of half-smooth tongue sole (Cynoglossus semilaevis).

Science.gov (United States)

Wang, Bin; Liu, Quan; Liu, Xuezhou; Xu, Yongjiang; Song, Xuesong; Shi, Bao

2017-11-01

Kisspeptin (Kiss) plays a critical role in mediating gonadal steroid feedback to the gonadotropin-releasing hormone (GnRH) neurons in mammals. However, little information regarding the regulation of kisspeptin gene by sex steroids is available in teleosts. In this study, we examined the direct actions of estradiol (E2) and testosterone (T) on hypothalamic expression of kisspeptin and other key factors involved in reproductive function of half-smooth tongue sole. As a first step, a partial-length cDNA of kiss2 was identified from the brain of tongue sole and kiss2 transcript levels were shown to be widely expressed in various tissues, notably in the ovary. Then, the actions of sex steroids on kiss2 and other reproduction-related genes were evaluated using a primary hypothalamus culture system. Our results showed that neither kiss2 nor its receptor kiss2r mRNA levels were significantly altered by sex steroids. Moreover, sex steroids did not modify hypothalamic expression of gonadotropin-inhibitory hormone (gnih) and its receptor gnihr mRNAs, either. However, E2 markedly stimulated both gnrh2 and gnrh3 mRNAs levels. Overall, this study provides insights into the role of sex steroids in the reproductive function of Pleuronectiform teleosts. Copyright © 2017 Elsevier Inc. All rights reserved.

Tyrosine kinase chromosomal translocations mediate distinct and overlapping gene regulation events

International Nuclear Information System (INIS)

Kim, Hani; Gillis, Lisa C; Jarvis, Jordan D; Yang, Stuart; Huang, Kai; Der, Sandy; Barber, Dwayne L

2011-01-01

Leukemia is a heterogeneous disease commonly associated with recurrent chromosomal translocations that involve tyrosine kinases including BCR-ABL, TEL-PDGFRB and TEL-JAK2. Most studies on the activated tyrosine kinases have focused on proximal signaling events, but little is known about gene transcription regulated by these fusions. Oligonucleotide microarray was performed to compare mRNA changes attributable to BCR-ABL, TEL-PDGFRB and TEL-JAK2 after 1 week of activation of each fusion in Ba/F3 cell lines. Imatinib was used to control the activation of BCR-ABL and TEL-PDGFRB, and TEL-JAK2-mediated gene expression was examined 1 week after Ba/F3-TEL-JAK2 cells were switched to factor-independent conditions. Microarray analysis revealed between 800 to 2000 genes induced or suppressed by two-fold or greater by each tyrosine kinase, with a subset of these genes commonly induced or suppressed among the three fusions. Validation by Quantitative PCR confirmed that eight genes (Dok2, Mrvi1, Isg20, Id1, gp49b, Cxcl10, Scinderin, and collagen Vα1(Col5a1)) displayed an overlapping regulation among the three tested fusion proteins. Stat1 and Gbp1 were induced uniquely by TEL-PDGFRB. Our results suggest that BCR-ABL, TEL-PDGFRB and TEL-JAK2 regulate distinct and overlapping gene transcription profiles. Many of the genes identified are known to be involved in processes associated with leukemogenesis, including cell migration, proliferation and differentiation. This study offers the basis for further work that could lead to an understanding of the specificity of diseases caused by these three chromosomal translocations

Reproductive and hormonal factors in male and female colon cancer

NARCIS (Netherlands)

Kampman, E.; Bijl, A.J.; Kok, C.; Veer, P. van 't

1994-01-01

We analysed data from a case-control study in the Netherlands in order to investigate whether reproductive events and hormonal factors are similarly related to colon cancer risk in men and women after adjustment for dietary factors. In total, 232 colon cancer cases (102 women, 130 men) and 259

Effects of fluctuating temperature and food availability on reproduction and lifespan.

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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.

Epigenetics of reproductive infertility.

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Das, Laxmidhar; Parbin, Sabnam; Pradhan, Nibedita; Kausar, Chahat; Patra, Samir K

2017-06-01

Infertility is a complex pathophysiological condition. It may caused by specific or multiple physical and physiological factors, including abnormalities in homeostasis, hormonal imbalances and genetic alterations. In recent times various studies implicated that, aberrant epigenetic mechanisms are associated with reproductive infertility. There might be transgenerational effects associated with epigenetic modifications of gametes and studies suggest the importance of alterations in epigenetic modification at early and late stages of gametogenesis. To determine the causes of infertility it is necessary to understand the altered epigenetic modifications of associated gene and mechanisms involved therein. This review is devoted to elucidate the recent mechanistic advances in regulation of genes by epigenetic modification and emphasizes their possible role related to reproductive infertility. It includes environmental, nutritional, hormonal and physiological factors and influence of internal structural architecture of chromatin nucleosomes affecting DNA and histone modifications in both male and female gametes, early embryogenesis and offspring. Finally, we would like to emphasize that research on human infertility by gene knock out of epigenetic modifiers genes must be relied upon animal models.

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.

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...

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

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

Marching toward reproductive justice: coalitional (re) framing of the March for Women's Lives.

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Luna, Zakiya T

2010-01-01

This article examines how coalition frames develop and what happens to that frame after the formal coalition ends. To that end, I analyze the frame shift around the 2004 March for Women's Lives (March). The March initially focused on established ideas of reproductive rights around which the four national mainstream co-sponsors previously organized. However, after a newer reproductive justice organization joined the coalition, material and organizing reflected a shift in framing to reproductive justice. How did this change happen? What are the impacts of this event for the women's movement? Through document analysis and interviews, I trace the negotiations that facilitated this framing shift. I argue that this new coalition frame translated into positive lasting changes in organizing for women's reproductive health even as the coalition dissolved and some of the tensions within the larger women's movement remain.

Obesity and the reproductive system disorders: epigenetics as a potential bridge.

Science.gov (United States)

Crujeiras, Ana B; Casanueva, Felipe F

2015-01-01

Obesity and overweight are significantly involved in several reproductive pathologies contributing to infertility in men and women. In addition, several cancers of the reproductive system, such as endometrial, ovarian, breast, testicular and prostate cancers, are strongly influenced by obesity. However, the molecular mechanisms involved in the association between obesity and reproductive disorders remain unclear. Our proposal is to review the current scientific evidence regarding the effect of obesity-related factors as the core of the collective mechanisms directly and indirectly involved in the relationship between obesity and reproductive disorders, with a special and original focus on the effect of the obesity state microenvironment on the epigenetic profile as a reversible mechanistic link between obesity and the reproductive disorders. A PubMed search was performed using keywords related to obesity and adipose-related factors and epigenetics and associated with keywords related to reproduction. Full-text articles and abstracts in the English language published prior to 31 December 2013 were reviewed. The obesity state notably contributes to a reproductive dysfunction in both men and women, ranging from infertility to oncological outcomes. Several epidemiological and experimental studies demonstrate that factors secreted by the adipose tissue and gut in an obesity state can directly induce reproductive disturbances. Relevantly, these same factors are able to alter the epigenetic regulation of genes, a dynamic and reversible mechanism by which the organism responds to environmental pressures critical to the reproductive function. This review outlines the evidence showing that the association between the reproductive pathologies and obesity is not inevitable but is potentially preventable and reversible. The epigenetic marks related to obesity could constitute a therapeutic target for the reproductive disorders associated with obesity. © The Author 2014

Developmental programming of reproductive and metabolic health1,2

Science.gov (United States)

Padmanabhan, V.; Veiga-Lopez, A.

2014-01-01

The 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 (~5 mo gestation and ~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 non-invasive 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 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 three 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/metabolic diseases, insulin resistance, hypertension and behavioral deficits. Collectively, the reproductive and metabolic deficits of prenatal T-treated sheep provide proof of concept for the

Functional study of Cordyceps sinensis and cordycepin in male reproduction: A review

Directory of Open Access Journals (Sweden)

Yung-Chia Chen

2017-01-01

Full Text Available Cordyceps sinensis has various biological and pharmacological functions, and it has been claimed as a tonic supplement for sexual and reproductive dysfunctions for a long time in oriental society. In this article, the in vitro and in vivo effects of C. sinensis and cordycepin on mouse Leydig cell steroidogenesis are briefly described, the stimulatory mechanisms are summarized, and the recent findings related to the alternative substances regulating male reproductive functions are also discussed.

Special Issue of The Lancet on Sexual and Reproductive Rights and ...

International Development Research Centre (IDRC) Digital Library (Canada)

The Lancet is the world's leading general medical journal and also publishes four monthly ... The special issue will feature research, policy, and program information to ... This group will consist of emerging and renowned population scientists, ... and international processes and events shaping the sexual and reproductive ...

Novel insights into host responses and reproductive pathophysiology of porcine reproductive and respiratory syndrome caused by PRRSV-2.

Science.gov (United States)

Harding, John C S; Ladinig, Andrea; Novakovic, Predrag; Detmer, Susan E; Wilkinson, Jamie M; Yang, Tianfu; Lunney, Joan K; Plastow, Graham S

2017-09-01

A large challenge experiment using North American porcine reproductive and respiratory virus (PRRSV-2) provided new insights into the pathophysiology of reproductive PRRS. Deep phenotyping of dams and fetuses identified maternal and fetal predictors of PRRS severity and resilience. PRRSV infection resulted in dramatic decreases in all leukocyte subsets by 2days post inoculation. Apoptosis in the interface region was positively related to endometrial vasculitis, viral load in endometrium and fetal thymus, and odds of meconium staining. Viral load at the maternal-fetal interface was a strong predictor of viral load in fetal thymus and odds of fetal death. However, interferon-alpha suppression, a consequence of PRRSV infection, was protective against fetal death. Although the prevalence of fetal lesions was low, their presence in fetal organs and umbilical cord was strongly associated with fetal compromise. Fetal death and viral load clustered in litters suggesting inter-fetal transmission starting from a limited number of index fetuses. Factors associated with index fetal infection are unclear, but large fetuses appear at greater risk. Disease progression in fetuses was associated with an up-regulation of genes associated with inflammation, innate immunity, and cell death signaling, and down-regulation of genes associated with cell cycle and lymphocyte quality. A number of maternal transcriptomic responses were associated with PRRS resilience including higher basal gene expression correlated with platelet function, interferon and pro-inflammatory responses. Twenty-one genomic regions across 10 chromosomes were associated with important traits including fetal viral load, fetal death and viability suggesting that selection for reproductive PRRS resilience may be possible. Copyright © 2017 Elsevier B.V. All rights reserved.

Arabidopsis thaliana MLO genes are expressed in discrete domains during reproductive development.

Science.gov (United States)

Davis, Thomas C; Jones, Daniel S; Dino, Arianna J; Cejda, Nicholas I; Yuan, Jing; Willoughby, Andrew C; Kessler, Sharon A

2017-12-01

MLOs in Plant Reproduction. The MILDEW RESISTANCE LOCUS-O (MLO) protein family, comprised of 15 members, plays roles in diverse cell-cell communication processes such as powdery mildew susceptibility, root thigmomorphogenesis, and pollen tube reception. The NORTIA (NTA, AtMLO7) gene is expressed in the synergid cells of the female gametophyte where it functions in intercellular communication with the pollen tube. Discrepancies between previously published promoter::GUS and promoter::gene-GUS constructs expression patterns led us to explore the regulation of NTA expression. Here we found via NTA pro ::gNTA-GUS truncations that sequences within the NTA gene negatively regulate its expression in the stomata and carpel walls. This led to the hypothesis that other MLO family members may also have additional regulatory sequences within the gene. MLO pro ::gMLO-GUS constructs were examined for each family member focusing specifically on flowers in order to determine whether other MLOs could play a role in reproductive cell-cell communication. Notably, several MLOs were expressed in the pollen, in the stigma, in the pollinated style, and in the synergids and central cell. These findings indicate that other MLOs in addition to NTA could play a role in reproduction. Previous studies on the MLO family showed that phylogenetically related MLOs had redundant functions in powdery mildew infection and root thigmomorphogenesis; however, MLO expression in reproductive tissues did not strictly follow phylogenetic relationships, indicating that MLOs from different evolutionary origins may have been recruited for function in sexual reproduction.

Reproductive success of Whiskered Tern Chlidonias hybrida in eastern Spain in relation to water level variation.

Science.gov (United States)

Ortiz Lledó, Álvaro; Vidal Mateo, Javier; Urios Moliner, Vicente

2018-01-01

A study on the Whiskered Tern Chlidonias hybrida was carried out between 2002 and 2009 in wetlands of eastern Spain to evaluate how water level fluctuation affects its reproductive success (hatching, fledgling and breeding success). This species is catalogued as Vulnerable in Spain and has an unfavorable conservation status in Europe. Our study includes 18 sampling areas from five wetlands, covering a total of 663 nests, 1,618 eggs, 777 nestlings and 225 fledglings. The colonies were visited at least twice per week in breeding period. The number of eggs and/or nestlings present in each nest were annotated each time the colonies were visited with the aim to compare the evolution of these parameters with time. Hatching success was calculated as the proportion of egg that hatched successfully. Fledgling success and breeding success were calculated as the proportion of chicks that fledged successfully and the proportion of eggs that produced fledglings. We used the Kruskal-Wallis test to analyze the differences in the dependent variables hatching, fledgling and breeding success among the wetlands and the sampling areas. We explored the relationship between the different reproductive success with the average fluctuation rate and the anchoring depth of nests, using statistics of the linear regression. It was observed that the reproductive success varied significantly in the interaction among the different categories of water level fluctuation and the different areas (using the Kruskal-Wallis test). Our records showed that pronounced variations in water level destroyed several nests, which affected the Whiskered Tern reproductive success. Considering all events that occurred in 18 areas, the mean (±SD) of nests, eggs and nestlings that were lost after water level fluctuations were of 25.60 ± 21.79%, 32.06 ± 27.58% and 31.91 ± 21.28% respectively, also including the effects of rain and predation. Unfavorable climatic events, such as strong wind, rain or hail, also

Reproductive success of Whiskered Tern Chlidonias hybrida in eastern Spain in relation to water level variation

Directory of Open Access Journals (Sweden)

Álvaro Ortiz Lledó

2018-04-01

climatic events, such as strong wind, rain or hail, also caused the loss of nests, eggs and nestlings, even when wetland water levels remained constant. The influence of the anchorage depth of the nest and the water level fluctuation rate were analyzed and did not provide statistically significant results. It was not possible to establish a clear pattern on these latter variables, so further studies are needed to obtain more significant results. We propose to undertake similar studies in wetlands where the water level can be regulated, with the range of nest anchorage depth on the emergent vegetation being between 30 and 60 cm, which could improve the reproductive success in this kind of habitats. As recommendation, in water level controlled wetlands (that use sluices, it should not vary more than ±6 cm in a short time (1–2 days once the nests are established since it negatively affects their reproductive success.

Managing the reproductive performance of beef cows.

Science.gov (United States)

Diskin, M G; Kenny, D A

2016-07-01

A reproductively efficient beef cow herd will be fundamental to meeting the protein and specifically, red meat demand of an ever increasing global population. However, attaining a high level of reproductive efficiency is underpinned by producers being cognizant of and achieving many key targets throughout the production cycle and requires considerable technical competency. The lifetime productivity of the beef-bred female commences from the onset of puberty and will be dictated by subsequent critical events including age at first calving, duration of the postpartum interval after successive calvings, conception and pregnancy rate, and ultimately manifested as length of intercalving intervals. In calved heifers and mature cows, the onset of ovarian activity, postpartum is a key event dictating the calving interval. Again, this will be the product mainly of prepartum nutrition, manifested through body condition score and the strength of the maternal bond between cow and calf, though there is increasing evidence of a modest genetic influence on this trait. After the initiation of postpartum ovarian cyclicity, conception and subsequent pregnancy rate is generally a function of bull fertility in natural service herds and heat detection and timing of insemination in herds bred through AI. Cows and heifers should be maintained on a steady plane of nutrition during the breeding season, but the contribution of significant excesses or deficiencies of nutrients including protein and trace elements is likely to be minor where adequate pasture is available. Although increased efforts are being made internationally to genetically identify and select for more reproductively efficient beef cows, this is a more long-term strategy and will not replace the need for a high level of technical efficiency and management practice at farm level. Copyright © 2016 Elsevier Inc. All rights reserved.

Correlated seed failure as an environmental veto to synchronize reproduction of masting plants.

Science.gov (United States)

Bogdziewicz, Michał; Steele, Michael A; Marino, Shealyn; Crone, Elizabeth E

2018-07-01

Variable, synchronized seed production, called masting, is a widespread reproductive strategy in plants. Resource dynamics, pollination success, and, as described here, environmental veto are possible proximate mechanisms driving masting. We explored the environmental veto hypothesis, which assumes that reproductive synchrony is driven by external factors preventing reproduction in some years, by extending the resource budget model of masting with correlated reproductive failure. We ran this model across its parameter space to explore how key parameters interact to drive seeding dynamics. Next, we parameterized the model based on 16 yr of seed production data for populations of red (Quercus rubra) and white (Quercus alba) oaks. We used these empirical models to simulate seeding dynamics, and compared simulated time series with patterns observed in the field. Simulations showed that resource dynamics and reproduction failure can produce masting even in the absence of pollen coupling. In concordance with this, in both oaks, among-year variation in resource gain and correlated reproductive failure were necessary and sufficient to reproduce masting, whereas pollen coupling, although present, was not necessary. Reproductive failure caused by environmental veto may drive large-scale synchronization without density-dependent pollen limitation. Reproduction-inhibiting weather events are prevalent in ecosystems, making described mechanisms likely to operate in many systems. © 2018 The Authors New Phytologist © 2018 New Phytologist Trust.

Melatonin and male reproductive health: relevance of darkness and antioxidant properties.

Science.gov (United States)

Rocha, C S; Rato, L; Martins, A D; Alves, M G; Oliveira, P F

2015-01-01

The pineal hormone melatonin controls several physiological functions that reach far beyond the regulation of the circadian rhythm. Moreover, it can be produced in extra-pineal organs such as reproductive organs. The role of melatonin in the mammalian seasonal and circadian rhythm is well known. Nevertheless, its overall effect in male reproductive physiology remains largely unknown. Melatonin is a very powerful endogenous antioxidant that can also be exogenously taken safely. Interestingly, its antioxidant properties have been consistently reported to improve the male reproductive dysfunctions associated with pathological conditions and also with the exposure to toxicants. Nevertheless, the exact molecular mechanisms by which melatonin exerts its action in the male reproductive system remain a matter of debate. Herein, we propose to present an up-to-date overview of the melatonin effects in the male reproductive health and debate future directions to disclose possible sites of melatonin action in male reproductive system. We will discuss not only the role of melatonin during darkness and sleep but also the importance of the antioxidant properties of this hormone to male fertility. Since melatonin readily crosses the physiological barriers, such as the blood-testis barrier, and has a very low toxicity, it appears as an excellent candidate in the prevention and/or treatment of the multiple male reproductive dysfunctions associated with various pathologies.

Regulation of Caenorhabditis elegans vitellogenesis by DAF-2/IIS through separable transcriptional and posttranscriptional mechanisms.

Science.gov (United States)

DePina, Ana S; Iser, Wendy B; Park, Sung-Soo; Maudsley, Stuart; Wilson, Mark A; Wolkow, Catherine A

2011-07-12

Evolutionary theories of aging propose that longevity evolves as a competition between reproduction and somatic maintenance for a finite pool of resources. Reproduction is thought to shorten lifespan by depleting resources from processes promoting somatic maintenance. Maternal yolk production, vitellogenesis, represents a significant maternal cost for reproduction and is suppressed under genetic and environmental conditions that extend lifespan. However, little is known about the pathways regulating vitellogenesis in response to prolongevity cues. In order to identify mechanisms that suppress vitellogenesis under prolongevity conditions, we studied factors regulating vitellogenesis in C. elegans nematodes. In C. elegans, vitellogenesis is depressed in the absence of insulin-like signaling (IIS). We found that the C. elegans daf-2/IIS pathway regulates vitellogenesis through two mechanisms. vit-2 transcript levels in daf-2 mutants were indirectly regulated through a germline-dependent signal, and could be rescued by introduction of daf-2(+) sperm. However, yolk protein (YP) levels in daf-2 mutants were also regulated by germline-independent posttranscriptional mechanisms. C. elegans vitellogenesis is regulated transcriptionally and posttranscriptionally in response to environmental and reproductive cues. The daf-2 pathway suppressed vitellogenesis through transcriptional mechanisms reflecting reproductive phenotypes, as well as distinct posttranscriptional mechanisms. This study reveals that pleiotropic effects of IIS pathway mutations can converge on a common downstream target, vitellogenesis, as a mechanism to modulate longevity.

Regulation of Caenorhabditis elegans vitellogenesis by DAF-2/IIS through separable transcriptional and posttranscriptional mechanisms

Directory of Open Access Journals (Sweden)

Wilson Mark A

2011-07-01

Full Text Available Abstract Background Evolutionary theories of aging propose that longevity evolves as a competition between reproduction and somatic maintenance for a finite pool of resources. Reproduction is thought to shorten lifespan by depleting resources from processes promoting somatic maintenance. Maternal yolk production, vitellogenesis, represents a significant maternal cost for reproduction and is suppressed under genetic and environmental conditions that extend lifespan. However, little is known about the pathways regulating vitellogenesis in response to prolongevity cues. Results In order to identify mechanisms that suppress vitellogenesis under prolongevity conditions, we studied factors regulating vitellogenesis in C. elegans nematodes. In C. elegans, vitellogenesis is depressed in the absence of insulin-like signaling (IIS. We found that the C. elegans daf-2/IIS pathway regulates vitellogenesis through two mechanisms. vit-2 transcript levels in daf-2 mutants were indirectly regulated through a germline-dependent signal, and could be rescued by introduction of daf-2(+ sperm. However, yolk protein (YP levels in daf-2 mutants were also regulated by germline-independent posttranscriptional mechanisms. Conclusions C. elegans vitellogenesis is regulated transcriptionally and posttranscriptionally in response to environmental and reproductive cues. The daf-2 pathway suppressed vitellogenesis through transcriptional mechanisms reflecting reproductive phenotypes, as well as distinct posttranscriptional mechanisms. This study reveals that pleiotropic effects of IIS pathway mutations can converge on a common downstream target, vitellogenesis, as a mechanism to modulate longevity.

Metabolic fuel and clinical implications for female reproduction.

Science.gov (United States)

Mircea, Carmen N; Lujan, Marla E; Pierson, Roger A

2007-11-01

Reproduction is a physiologically costly process that consumes significant amounts of energy. The physiological mechanisms controlling energy balance are closely linked to fertility. This close relationship ensures that pregnancy and lactation occur only in favourable conditions with respect to energy. The primary metabolic cue that modulates reproduction is the availability of oxidizable fuel. An organism's metabolic status is transmitted to the brain through metabolic fuel detectors. There are many of these detectors at both the peripheral (e.g., leptin, insulin, ghrelin) and central (e.g., neuropeptide Y, melanocortin, orexins) levels. When oxidizable fuel is scarce, the detectors function to inhibit the release of gonadotropin-releasing hormone and luteinizing hormone, thereby altering steroidogenesis, reproductive cyclicity, and sexual behaviour. Infertility can also result when resources are abundant but food intake fails to compensate for increased energy demands. Examples of these conditions in women include anorexia nervosa and exercise-induced amenorrhea. Infertility associated with obesity appears to be less related to an effect of oxidizable fuel on the hypothalamic-pituitary-ovarian axis. Impaired insulin sensitivity may play a role in the etiology of these conditions, but their specific etiology remains unresolved. Research into the metabolic regulation of reproductive function has implications for elucidating mechanisms of impaired pubertal development, nutritional amenorrhea, and obesity-related infertility. A better understanding of these etiologies has far-reaching implications for the prevention and management of reproductive dysfunction and its associated comorbidities.

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....

Applying nutrition and physiology to improve reproduction in dairy cattle.

Science.gov (United States)

Santos, J E P; Bisinotto, R S; Ribeiro, E S; Lima, F S; Greco, L F; Staples, C R; Thatcher, W W

2010-01-01

The establishment and maintenance of pregnancy in lactating dairy cows is a complex biological event that is influenced by a multitude of factors, from the reproductive biology of the cow to managerial aspects of the dairy farm. It is often mentioned in the scientific literature that fertility in dairy cows has declined concurrent with major advances in milk production. Some of this decline is attributed to the negative genetic correlation between milk production and reproduction. In the United States, yearly production per cow has increased steadily at a rate of 1.3% in the last decade and it is likely that this trend will continue in the years to come. At this rate, the average cow in the United States will be producing over 14 tons of milk per year in 2050 and technologies will have to be developed to allow these cows to reproduce to maintain the sustainability of dairy production. Despite high production, it is not uncommon for dairy herds with rolling herd averages for milk yield above 11,000 kg to overcome the challenges of reproduction and obtain satisfactory reproductive performance. Among other things, those herds have been able to mitigate some of the mechanisms that suppress reproduction in dairy cows such as extended postpartum anovulatory period, poor estrous detection, low pregnancy per insemination and, to a lesser extent, the high pregnancy loss. The success of those farms comes from an integrated approach to fertility that includes adequate cow comfort, elaborated transition cow management and nutrition, aggressive postpartum health monitoring program with preventative and curative measures to mitigate the negative effects of diseases on reproduction, and a sound reproductive program that includes manipulation of the ovarian cycle to allow for increased insemination rate. More recently, introduction of fertility traits in selection programs have created new opportunities for improved reproduction without neglecting economically important production

Gonadotropin subunits of the characiform Astyanax altiparanae : Molecular characterization, spatiotemporal expression and their possible role on female reproductive dysfunction in captivity

NARCIS (Netherlands)

de Jesus, Lázaro Wender O; Bogerd, Jan; Vieceli, Felipe M; Branco, Giovana S; Camargo, Marília P; Cassel, Mônica; Moreira, Renata G; Yan, Chao Y I; Borella, Maria I.

2017-01-01

To better understand the endocrine control of reproduction in Characiformes and the reproductive dysfunctions that commonly occur in migratory fish of this order when kept in captivity, we chose Astyanax altiparanae, which has asynchronous ovarian development and multiple spawning events, as model

Training in reproductive endocrinology and infertility and assisted reproductive technologies: options and worldwide needs.

Science.gov (United States)

de Ziegler, Dominique; de Ziegler, Nathalie; Sean, Sokteang; Bajouh, Osama; Meldrum, David R

2015-07-01

Standardized, high-quality training in reproductive endocrinology, infertility, and assisted reproductive technologies (REI-ART) faces challenges owing to the high-tech nature of ART and the important country-to-country differences in clinical practice and regulations overseeing training. Moreover, while the training capacity of the classical by-fellowship training platforms is shrinking, an increasing demand for REI-ART specialists is coming from emerging countries. To meet this expanding need for REI-ART specialists, we propose a novel by-network model linking a reference training center to satellite practical training sites. Simulation should be used more extensively to achieve competency before initiating live clinical experience, analogous to the highly effective training systems that have been used in aviation for decades. Large ART databases that exist because of obligations to report ART activity and results constitute unique yet so far untapped sources for developing by-scenario simulation training models. Online training materials incorporating these state-of-the-art information technology tools could be developed as a means of fulfilling training needs worldwide. Copyright © 2015. Published by Elsevier Inc.

Reproductive technology: in Britain, the debate after the Warnock Report.

Science.gov (United States)

Gillon, Raanan

1987-06-01

Gillon contributes an article on Great Britain to the Hastings Center Report series on reproductive technologies outside the United States. In 1984 the Warnock Committee's report represented the first attempt by a national government to formulate a policy on reproductive issues such as artificial insemination, in vitro fertilization, surrogate mothers, and research on human embryos. Reaction to the Warnock report has focused on its recommendations to ban commercial surrogacy and to allow experimentation on embryos up to 14 days after fertilization. Legislation on surrogacy was passed in 1985, while bills banning embryo research failed in 1986. A 1986 government consultation paper called for discussion of other aspects of the Warnock report, including its recommendation that a statutory licensing authority to regulate reproductive technologies be established. Gillon predicts that no new legislation will be enacted under the present government.

Female-Specific Glucose Sensitivity of GnRH1 Neurons Leads to Sexually Dimorphic Inhibition of Reproduction in Medaka.

Science.gov (United States)

Hasebe, Masaharu; Kanda, Shinji; Oka, Yoshitaka

2016-11-01

Close interaction exists between energy-consuming reproduction and nutritional status. However, there are differences in costs and priority for reproduction among species and even between sexes, which leads to diversification of interactions between reproduction and nutritional status. Despite such diversified interactions among species and sexes, most of the analysis of the nutritional status-dependent regulation of reproduction has been limited to an endothermic vertebrate, mammalian species of either sex. Therefore, the mechanisms underlying the diversified interactions remain elusive. In the present study, we demonstrated the effects of malnutritional status on reproduction at both organismal and cellular levels in an ectothermic vertebrate, a teleost medaka of both sexes. First, we analyzed the effects of malnutrition by fasting on gonadosomatic index, number of spawned/fertilized eggs, and courtship behavior. Fasting strongly suppressed reproduction in females but, surprisingly, not in males. Next, we analyzed the effects of fasting on firing activity of hypothalamic GnRH1 neurons, which form the final common pathway for the control of reproduction. An electrophysiological analysis showed that low glucose, which is induced by fasting, directly suppresses the firing activity of GnRH1 neurons specifically in females through intracellular ATP-sensitive potassium channels and AMP-activated protein kinase pathways. Based on the fact that such suppressions occurred only in females, we conclude that nutritional status-dependent, glucose-sensing in GnRH1 neurons may contribute to the most fitted reproductive regulation for each sex.

Characterization and differential expression of three GnRH forms during reproductive development in cultured turbot Schophthalmus maximus

Science.gov (United States)

Zhao, Chunyan; Xu, Shihong; Feng, Chengcheng; Liu, Yifan; Yang, Yang; Wang, Yanfeng; Xiao, Yongshuang; Song, Zongcheng; Liu, Qinghua; Li, Jun

2017-10-01

Turbots (Schophthalmus maximus), one of the most important economic marine flatfish species, fail to undergo final spawning and spermiation naturally under artificial farming conditions. In vertebrates, reproduction is regulated by the brain-pituitary-gonadal axis (BPG-axis), and gonadotropin releasing hormone (GnRH) is one of its key components. Therefore, to better understand the physiology of reproduction in the turbot, three of the genes encoding GnRH subtypes—sbGnRH, cGnRH-II and sGnRH—were cloned and sequenced by isolating the cDNA sequences. The localizations and patterns of expression of their mRNAs were also evaluated during seasonal gonadal development. All three mRNAs were expressed abundantly in the brain; sbGnRH and sGnRH mRNAs were also detected in the gonads and pituitary gland, and sbGnRH expression was much higher than that of sGnRH, indicating the critical role of sbGnRH in regulating the BPG-axis. Moreover, the brain expression patterns of sbGnRH and sGnRH mRNAs showed an increased trend during gonadal development, peaking in mature stages. This indicated the direct regulation of gonadal development by the GnRH system. In addition, cGnRH-II mRNA expression showed no significant variations, suggesting that cGnRH-II is not critically involved in the control of reproduction. Further, the mRNA abundances of the three GnRH forms in the breeding season were significantly higher than those in immature and post-breeding stages in all analyzed brain areas. Therefore, we propose that sbGnRH is the most important hormone for the regulation of reproduction in turbot via the BPG-axis. These results will help in better understanding the reproductive endocrine mechanisms of turbots and lay the groundwork for additional studies aimed at comparing the reproductive physiology of wild individuals with those raised under artificial conditions.

78 FR 33700 - Special Local Regulations for Marine Events, Pleasantville Aquatics 15th Annual 5K Open Water...

Science.gov (United States)

2013-06-05

...-AA08 Special Local Regulations for Marine Events, Pleasantville Aquatics 15th Annual 5K Open Water Swim... Waterway for the Pleasantville Aquatics 15th Annual 5K Open Water Swim. The Captain of the Port, Sector..., Pleasantville Aquatics 15th Annual 5K Open Water Swim, Intracoastal Waterway; Atlantic City, NJ. (a) Location...

Reproduction Patterns of Scleractinian Corals in the Central Red Sea

KAUST Repository

Bouwmeester, Jessica

2013-12-01

Early work on the reproductive seasonality of corals in the Red Sea suggested that corals exhibit temporal reproductive isolation, unlike on the Great Barrier Reef where many species spawn in synchrony. More recent work has however shown high synchrony in the maturity of gametes in Acropora species, suggesting multi-specific spawning is likely to occur in the Red Sea. In this thesis I investigate the patterns of coral reproduction in the central Red Sea. The spawning season in the central Red Sea lasts four months, from April to July and spawning occurs on nights around the full moon. During this period Acropora species show a peak of spawning in April, with some species spawning again in May. The level of synchrony, quantified with a spawning synchrony index, is comparable to other locations where multi-specific spawning has been reported. Observations over two consecutive years show that the synchrony of spawning was lower in spring 2012 than in spring 2011, and thus that spawning patterns are variable from one year to the other. Coral settlement patterns on artificial substrata confirmed a main spawning season in the spring but also supported reproductive data suggesting that some Porites spawn in October-November. Settlement was studied over 2.5 years on a reef, which had suffered recently from high mortality after a local bleaching event. Settlement appeared low but post-bleaching studies from other locations indicated similar abundances and showed that recruits generally did not increase until 5 years after the bleaching event. Abundance of juvenile corals however started to increase significantly three years after the bleaching. Successful recruitment, although low suggests that the coral assemblage on the affected reef will most likely recover as long as it is not affected by another disturbance.

A conserved non-reproductive GnRH system in chordates.

Directory of Open Access Journals (Sweden)

Takehiro G Kusakabe

Full Text Available Gonadotropin-releasing hormone (GnRH is a neuroendocrine peptide that plays a central role in the vertebrate hypothalamo-pituitary axis. The roles of GnRH in the control of vertebrate reproductive functions have been established, while its non-reproductive function has been suggested but less well understood. Here we show that the tunicate Ciona intestinalis has in its non-reproductive larval stage a prominent GnRH system spanning the entire length of the nervous system. Tunicate GnRH receptors are phylogenetically closest to vertebrate GnRH receptors, yet functional analysis of the receptors revealed that these simple chordates have evolved a unique GnRH system with multiple ligands and receptor heterodimerization enabling complex regulation. One of the gnrh genes is conspicuously expressed in the motor ganglion and nerve cord, which are homologous structures to the hindbrain and spinal cord of vertebrates. Correspondingly, GnRH receptor genes were found to be expressed in the tail muscle and notochord of embryos, both of which are phylotypic axial structures along the nerve cord. Our findings suggest a novel non-reproductive role of GnRH in tunicates. Furthermore, we present evidence that GnRH-producing cells are present in the hindbrain and spinal cord of the medaka, Oryzias latipes, thereby suggesting the deep evolutionary origin of a non-reproductive GnRH system in chordates.

Circadian Rhythms and Clock Genes in Reproduction: Insights From Behavior and the Female Rabbit’s Brain

Directory of Open Access Journals (Sweden)

Mario Caba

2018-03-01

Full Text Available Clock gene oscillations are necessary for a successful pregnancy and parturition, but little is known about their function during lactation, a period demanding from the mother multiple physiological and behavioral adaptations to fulfill the requirements of the offspring. First, we will focus on circadian rhythms and clock genes in reproductive tissues mainly in rodents. Disruption of circadian rhythms or proper rhythmic oscillations of clock genes provoke reproductive problems, as found in clock gene knockout mice. Then, we will focus mainly on the rabbit doe as this mammal nurses the young just once a day with circadian periodicity. This daily event synchronizes the behavior and the activity of specific brain regions critical for reproductive neuroendocrinology and maternal behavior, like the preoptic area. This region shows strong rhythms of the PER1 protein (product of the Per1 clock gene associated with circadian nursing. Additionally, neuroendocrine cells related to milk production and ejections are also synchronized to daily nursing. A threshold of suckling is necessary to entrain once a day nursing; this process is independent of milk output as even virgin does (behaving maternally following anosmia can display circadian nursing behavior. A timing motivational mechanism may regulate such behavior as mesolimbic dopaminergic cells are entrained by daily nursing. Finally, we will explore about the clinical importance of circadian rhythms. Indeed, women in chronic shift-work schedules show problems in their menstrual cycles and pregnancies and also have a high risk of preterm delivery, making this an important field of translational research.

Possible influence of vitamin D on male reproduction

DEFF Research Database (Denmark)

Boisen, Ida Marie; Hansen, Lasse Bøllehuus; Mortensen, Li Juel

2017-01-01

Vitamin D is a versatile signaling molecule with an established role in the regulation of calcium homeostasis and bone health. In recent years the spectrum of vitamin D target organs has expanded and a reproductive role is supported by the presence of the vitamin D receptor (VDR) and the vitamin D...... studies have supported the notion of a positive association between serum 25-hydroxyvitamin D (25-OHD) level and semen quality in both fertile and infertile men. However, it remains to be determined whether this association reflects a causal effect. The VDR is ubiquitously expressed and activated vitamin...... steroid production in infertile men. In this review known and possible future implications of vitamin D in human male reproduction function will be discussed....

"Clean, green and ethical" animal production. Case study: reproductive efficiency in small ruminants.

Science.gov (United States)

Martin, Graeme B; Kadokawa, Hiroya

2006-02-01

In response to changes in society and thus the marketplace, we need a vision for the future of our animal industries, including both on-farm and off-farm activities, that is "clean, green and ethical". Using small ruminants as a case study, we describe three "clean, green and ethical" strategies that farmers could use to improve reproductive performance. The first allows control of the timing of reproductive events by using socio-sexual signals (the "male effect") to induce synchronised ovulation in females. The second strategy, "focus feeding", is based on using short periods of nutritional supplements that are precisely timed and specifically designed for each event in the reproductive process (eg, gamete production, embryo survival, fetal programming, colostrum production). The third strategy aims to maximize offspring survival by a combination of management, nutrition and genetic selection for behaviour (temperament). All of these approaches involve non-pharmacological manipulation of the endogenous control systems of the animals and complement the detailed information from ultrasound that is now becoming available. Importantly, these approaches all have a solid foundation in reproductive biology. In several cases, they are currently used in commercial practice, but there is still room for improvement through both basic and applied research. Ultimately, these "clean, green and ethical" tools can be cost-effective, increase productivity and, at the same time, greatly improve the image of meat and milk industries in society and the marketplace.

Extreme drought alters frequency and reproductive success of floaters in Willow Flycatchers

Science.gov (United States)

Theimer, Tad; Sogge, Mark K.; Cardinal, Suzanne N.; Durst, Scott L.; Paxton, Eben H.

2018-01-01

Changes in habitat quality, including those caused by extreme events like droughts and floods, could alter costs and benefits of territoriality and thereby the prevalence and reproductive consequences for individuals capable of breeding that do not do so (floaters). We studied floating behavior in a population of Southwestern Willow Flycatchers (Empidonax traillii extimus) in central Arizona during one year of extreme drought, one year of lake inundation, and three years of near average precipitation. In all years, most floaters were second year (SY) males, and most subsequently settled outside of the patch where they were detected in the floating year, suggesting that floaters did not “queue” at high-quality territories in order to achieve higher reproductive success in subsequent years. Instead, cohorts that floated in non-drought years had lower apparent survival and lower reproductive success compared to territorial birds. In the extreme drought year, however, the number of floaters was 1.5 times greater than in all other years combined, more females floated, and apparent survival and mean annual productivity in subsequent years was higher for males that floated in that year than for those that were territorial. Inundation of habitat due to rising reservoir levels did not result in an increase in floaters because many birds nested in inundated areas where trees projected above the water so that the relative amount of available habitat was not reduced to the extent habitat models predicted. Overall, our results indicate that the prevalence and reproductive and demographic consequences of floating can change under extreme climatic events like severe drought.

Growth and male reproduction improvement of non-thermal dielectric barrier discharge plasma treatment on chickens

Science.gov (United States)

Jiao Zhang, Jiao; Luong Huynh, Do; Chandimali, Nisansala; Kang, Tae Yoon; Kim, Nameun; Mok, Young Sun; Kwon, Taeho; Jeong, Dong Kee

2018-05-01

This study investigated whether plasma treatment of fertilized eggs before hatching could affect the growth and reproduction of chickens. Three point five-day-incubated fertilized eggs exposed to non-thermal dielectric barrier discharge plasma at 2.81 W of power for 2 min resulted in the highest growth in chickens. Plasma growth-promoting effect was regulated by the reactive oxygen species homeostasis and the improvement of energy metabolism via increasing serum hormones and adenosine triphosphate levels which were resulted from the regulation of genes involved in antioxidant defense, hormone biosynthesis and energetic metabolism. Interestingly, plasma-treated male chickens conspicuously grew faster than females. Further, aspects of male reproductive system (testosterone level and sperm quality) were improved by the plasma treatment but female reproduction (estradiol and progesterone levels, egg-laying rate and egg weight) had no significant changes. Unfortunately, offspring whose parents were the optimal plasma-treated chickens did not show any difference on growth characteristics and failed to inherit excellent growth features from their parents. Our results suggest a new method to improve the growth rate and male reproductive capacity in poultry but it is only effective in the plasma direct-treated generation.

Little evidence for intralocus sexual conflict over the optimal intake of nutrients for life span and reproduction in the black field cricket Teleogryllus commodus.

Science.gov (United States)

Rapkin, James; Archer, C Ruth; Grant, Charles E; Jensen, Kim; House, Clarissa M; Wilson, Alastair J; Hunt, John

2017-09-01

There is often large divergence in the effects of key nutrients on life span (LS) and reproduction in the sexes, yet nutrient intake is regulated in the same way in males and females given dietary choice. This suggests that the sexes are constrained from feeding to their sex-specific nutritional optima for these traits. Here, we examine the potential for intralocus sexual conflict (IASC) over optimal protein and carbohydrate intake for LS and reproduction to constrain the evolution of sex-specific nutrient regulation in the field cricket, Teleogryllus commodus. We show clear sex differences in the effects of protein and carbohydrate intake on LS and reproduction and strong positive genetic correlations between the sexes for the regulated intake of these nutrients. However, the between-sex additive genetic covariance matrix had very little effect on the predicted evolutionary response of nutrient regulation in the sexes. Thus, IASC appears unlikely to act as an evolutionary constraint on sex-specific nutrient regulation in T. commodus. This finding is supported by clear sexual dimorphism in the regulated intake of these nutrients under dietary choice. However, nutrient regulation did not coincide with the nutritional optima for LS or reproduction in either sex, suggesting that IASC is not completely resolved in T. commodus. © 2017 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

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

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

Regulation of gonadotropin-releasing hormone neurons by glucose

Science.gov (United States)

Roland, Alison V.; Moenter, Suzanne M.

2011-01-01

Reproduction is influenced by energy balance, but the physiological pathways mediating their relationship have not been fully elucidated. As the central regulators of fertility, gonadotropin-releasing hormone (GnRH) neurons integrate numerous physiological signals, including metabolic cues. Circulating glucose levels regulate GnRH release and may in part mediate the effects of negative energy balance on fertility. Existing evidence suggests that neural pathways originating in the hindbrain, as well as in the hypothalamic feeding nuclei, transmit information concerning glucose availability to GnRH neurons. Here we review recent evidence suggesting that GnRH neurons may directly sense changes in glucose availability by a mechanism involving adenosine monophosphate-activated protein kinase (AMPK). These findings expand our understanding of how metabolic signaling in the brain regulates reproduction. PMID:21855365

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.

The community-level effects of women's education on reproductive behaviour in rural Ghana

Directory of Open Access Journals (Sweden)

Kofi D. Benefo

2006-06-01

Full Text Available Using survey and census data for rural Ghana collected in the 1980s, this study examines the ability of women's education to increase interest in fertility regulation and contraception among all women, regardless of their individual and household features. The study finds that, net of her own characteristics, a woman's interest in limiting fertility and using modern contraception increase with the percent of educated women in her community. These results suggest that female education has a greater capacity to introduce novel reproductive ideas and behaviors into rural areas of Africa and thereby transform the demographic landscape in the region than is currently believed. There is also evidence that female education may undermine existing methods of regulating fertility. Other community characteristics that increase women's interest in regulating fertility and contraceptive use in this setting include access to transportation and proximity to urban areas. However, these are not as powerful as women's education in transforming reproductive behavior.

Vitamin D metabolism, sex hormones, and male reproductive function.

Science.gov (United States)

Blomberg Jensen, Martin

2012-08-01

The spectrum of vitamin D (VD)-mediated effects has expanded in recent years, and VD is now recognized as a versatile signaling molecule rather than being solely a regulator of bone health and calcium homeostasis. One of the recently identified target areas of VD is male reproductive function. The VD receptor (VDR) and the VD metabolizing enzyme expression studies documented the presence of this system in the testes, mature spermatozoa, and ejaculatory tract, suggesting that both systemic and local VD metabolism may influence male reproductive function. However, it is still debated which cell is the main VD target in the testis and to what extent VD is important for sex hormone production and function of spermatozoa. This review summarizes descriptive studies on testicular VD metabolism and spatial distribution of VDR and the VD metabolizing enzymes in the mammalian testes and discusses mechanistic and association studies conducted in animals and humans. The reviewed evidence suggests some effects of VD on estrogen and testosterone biosynthesis and implicates involvement of both systemic and local VD metabolism in the regulation of male fertility potential.

Effects of dietary soybean isoflavones (SI) on reproduction in the young breeder rooster.

Science.gov (United States)

Heng, Dai; Zhang, Tao; Tian, Ye; Yu, Shangyu; Liu, Wenbo; Xu, Kaili; Liu, Juan; Ding, Yu; Zhu, Baochang; Yang, Yanzhou; Zhang, Cheng

2017-02-01

Soybean isoflavones (SIs) are phytoestrogens that competitive with estrogens in body. Although SIs play an important role in reproduction, their role in testicular development in roosters is unknown. This study was conducted to investigate the effect of SIs on testicular development and serum reproductive hormone profiles in young breeder roosters (70-133days old). Gene expression of steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450scc), and 3β-hydroxysteroid dehydrogenase (3β-HSD), which are related to testosterone synthesis, in rooster testis were also evaluated after treatment with different SI doses. Although SIs had no significant effect on body weight, 5mg/kg SIs significantly increased the testis index and serum levels of reproductive hormones (gonadotropin releasing hormone, follicle- stimulating hormone, luteinizing hormone, and testosterone).To further investigate whether SIs regulate hormone synthesis via StAR, p450scc, 3β-HSD, real time-PCR was performed to measure the mRNA levels of the corresponding genes. The results showed that 5mg/kg of SIs significantly increased StAR mRNA levels. However, there were no significant effects on p450scc or 3β-HSD mRNA levels. Moreover, the spermatogonial development and the number of germ cell layers were increased by treatment with 5mg/kg of SIs. These results suggest that SIs promote testicular growth by increasing reproductive hormone secretion, which is closely related to StAR expression, to positively regulate reproduction in young roosters. Copyright © 2016 Elsevier B.V. All rights reserved.

The reproductive biology and early life ecology of a common Caribbean brain coral, Diploria labyrinthiformis (Scleractinia: Faviinae)

Science.gov (United States)

Chamberland, Valérie F.; Snowden, Skylar; Marhaver, Kristen L.; Petersen, Dirk; Vermeij, Mark J. A.

2017-03-01

Despite the fact that most of the severe demographic bottlenecks in coral populations occur during their earliest life stages, information on the reproductive biology and early life history traits of many coral species is limited and often inferred from adult traits only. This study reports on several atypical aspects of the reproductive biology and early life ecology of the grooved brain coral, Diploria labyrinthiformis (Linnaeus, 1758), a conspicuous reef-building species on Caribbean reefs. The timing of gamete release of D. labyrinthiformis was monitored in Curaçao over eight consecutive months, and embryogenesis, planulae behavior, and settlement rates were observed and quantified. We further studied growth and symbiont acquisition in juvenile D. labyrinthiformis for 3.5 yr and compared settler survival under ambient and nutrient-enriched conditions in situ. Notably, D. labyrinthiformis reproduced during daylight hours in six consecutive monthly spawning events between May and September 2013, with a peak in June. This is the largest number of reproductive events per year ever observed in a broadcast-spawning Caribbean coral species. In settlement experiments, D. labyrinthiformis planulae swam to the bottom of culture containers 13 h after spawning and rapidly settled when provided with settlement cues (42% within 14 h). After 5 months, the survival and growth rates of settled juveniles were 3.7 and 1.9 times higher, respectively, for settlers that acquired zooxanthellae within 1 month after settlement, compared to those that acquired symbionts later on. Nutrient enrichment increased settler survival fourfold, but only for settlers that had acquired symbionts within 1 month after settlement. With at least six reproductive events per year, a short planktonic larval phase, high settlement rates, and a positive response to nutrient enrichment, the broadcast-spawning species D. labyrinthiformis displays a range of reproductive and early life-history traits that

Vitamin D (soltriol), light, and reproduction

International Nuclear Information System (INIS)

Stumpf, W.E.; Denny, M.E.

1989-01-01

Evidence from autoradiographic studies with 1,25(OH)2-vitamin D3 (vitamin D, soltriol) labeled with tritium and from the literature indicates that the steroid hormone soltriol regulates and modulates reproductive processes in the female, as it does in the male. Nuclear receptors for soltriol have been discovered in the uterus, oviduct, ovary, mammary gland, placenta, and fetal membranes, as well as in the pituitary and hypothalamus. Soltriol is recognized as a transducer and hormonal messenger of sunlight, acting as a somatotropic activator and modulator of vital processes for the seasonal and estival adaptation of growth, development, and procreation. Its influence on calcium equilibrium is just one of its many functions to serve this goal. This article reviews experimental, clinical, and epidemiologic evidence that suggests the involvement of soltriol in the control of reproductive processes, noting its importance for the onset of puberty, fertility, pregnancy, lactation, and probably sexual behavior. Cooperative actions between soltriol and other steroid hormones, especially estradiol, are pointed out.107 references

Airway exposure to multi-walled carbon nanotubes disrupts the female reproductive cycle without affecting pregnancy outcomes in mice

DEFF Research Database (Denmark)

Johansson, Hanna Katarina Lilith; Hansen, J. S.; Elfving, B.

2017-01-01

response and inflammation in experimental animals, which may affect female reproduction. This proof-of-principle study therefore aimed to investigate if lung exposure by intratracheal instillation of the MWCNT NM-400 would affect the estrous cycle and reproductive function in female mice.Results: Estrous...... of irregular cycling after exposure. Our data indicates that MWCNT exposure may interfere with events leading to ovulation....

Distributed Nonlinear Control with Event-Triggered Communication to Achieve Current-Sharing and Voltage Regulation in DC Microgrids

DEFF Research Database (Denmark)

Han, Renke; Meng, Lexuan; Guerrero, Josep M.

2018-01-01

combining the state-dependent tolerance with a nonnegative offset. In order to design the event-triggered principle and guarantee the global stability, a generalized dc microgrid model is proposed and proven to be positive definite, based on which Lyapunov-based approach is applied. Furthermore, considering......A distributed nonlinear controller is presented to achieve both accurate current-sharing and voltage regulation simultaneously in dc microgrids considering different line impedances’ effects among converters. Then, an improved event-triggered principle for the controller is introduced through...... for precise real-time information transmission, without sacrificing system performance. Experimental results obtained from a dc microgrid setup show the robustness of the new proposal under normal, communication failure, communication delay and plug-and-play operation conditions. Finally, communication...

Leptin and its potential interest in assisted reproduction cycles.

Science.gov (United States)

Catteau, A; Caillon, H; Barrière, P; Denis, M G; Masson, D; Fréour, T

2016-04-01

Leptin, an adipose hormone, has been shown to control energy homeostasis and food intake, and exert many actions on female reproductive function. Consequently, this adipokine is a pivotal factor in studies conducted on animal models and humans to decipher the mechanisms behind the infertility often observed in obese women. A systematic PubMed search was conducted on all articles, published up to January 2015 and related to leptin and its actions on energy balance and reproduction, using the following key words: leptin, reproduction, infertility, IVF and controlled ovarian stimulation. The available literature was reviewed in order to provide an overview of the current knowledge on the physiological roles of leptin, its involvement in female reproductive function and its potential interest as a prognostic marker in IVF cycles. Animal and human studies show that leptin communicates nutritional status to the central nervous system and emerging evidence has demonstrated that leptin is involved in the control of reproductive functions by acting both directly on the ovaries and indirectly on the central nervous system. With respect to the clinical use of leptin as a biomarker in IVF cycles, a systematic review of the literature suggested its potential interest as a predictor of IVF outcome, as high serum and/or follicular fluid leptin concentrations have correlated negatively with cycle outcome. However, these preliminary results remain to be confirmed. Leptin regulates energy balance and female reproductive function, mainly through its action on hypothalamic-pituitary-ovarian function, whose molecular and cellular aspects are progressively being deciphered. Preliminary studies evaluating leptin as a biomarker in human IVF seem promising but need further confirmation. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Optimising reproductive performance of beef cows and replacement heifers.

Science.gov (United States)

Diskin, M G; Kenny, D A

2014-05-01

A reproductively efficient beef cow herd is fundamental to meeting the protein and specifically, red meat demand of an ever increasing global population. However, attaining a high level of reproductive efficiency is underpinned by producers being cognisant of and achieving many key targets throughout the production cycle and requires significant technical competency. The lifetime productivity of the beef bred female commences from the onset of puberty and will be dictated by subsequent critical events including age at first calving, duration of the postpartum interval for each successive calving, conception and pregnancy rate and ultimately manifested as length of intercalving intervals and number of calves weaned over her lifetime. Puberty in heifers is a consequence of the interactive effects of genetics and both pre- and post-weaning nutrition. Early onset of puberty is essential to achieving the first main reproductive target for beef cow herds; first calving at 2 years of age. In calved heifers and mature cows, the onset of ovarian activity, postpartum is a key event dictating the calving interval. Again, this will be the product mainly of prepartum nutrition, manifested through body condition and the strength of the maternal bond between cow and calf, though there is increasing evidence of a modest genetic influence on this trait. Following the initiation of postpartum ovarian cyclicity, conception and subsequent pregnancy rate is generally a function of bull fertility in natural service herds and heat detection and timing of insemination in herds bred through artificial insemination. Cows and heifers should be maintained on a steady plane of nutrition during the breeding season, but the contribution of significant excesses or deficiencies of nutrients including protein and trace elements is likely to be minor where adequate pasture is available. While, increased efforts are being made internationally to genetically identify and select for more reproductively

'Not so wrong that we are prepared to threaten the entire service': the regulation of reproductive technologies in the UK.

Science.gov (United States)

Levitt, M

2001-01-01

In the UK human embryo research and infertility treatments are regulated by the Human Fertilisation and Embryology Authority (HFEA), a national statutory body set up in 1991. Clinics are required by law to be licensed by the HFEA and open to inspection. In 1999 there were 107 clinics licensed to carry out IVF and/or donor insemination. There are regional variations in National Health Service funding and seventy-five percent of those treated pay for most of their treatment, usually to avoid long waiting lists or because they do not meet the eligibility criteria set by their local health authority. Having described the code of practice laid down by the HFEA the paper discusses the implications of new reproductive technologies from a social science perspective, focusing on three topics which continue to be debated by the media, the regulatory authorities, health professionals and 'lay' people. First, age limits and other criteria for assisted reproduction which raise the question 'who should be allowed to reproduce?' Second, donor anonymity and the question of payment for donors. Finally, the screening and selection of embryos for implantation and the recurring theme in the media of 'designer babies'. The HFEA can be seen to fulfill its intended role, mediating between the infertility professionals, patients and the wider general public. It seeks to allay public fears while supporting professionals by avoiding restrictions on research and treatment and by consulting with the public as to when extensions to research will be acceptable.

Correlated genetic effects on reproduction define a domestication syndrome in a forest tree

Science.gov (United States)

Santos-del-Blanco, Luis; Alía, Ricardo; González-Martínez, Santiago C; Sampedro, Luis; Lario, Francisco; Climent, José

2015-01-01

Compared to natural selection, domestication implies a dramatic change in traits linked to fitness. A number of traits conferring fitness in the wild might be detrimental under domestication, and domesticated species typically differ from their ancestors in a set of traits known as the domestication syndrome. Specifically, trade-offs between growth and reproduction are well established across the tree of life. According to allocation theory, selection for growth rate is expected to indirectly alter life-history reproductive traits, diverting resources from reproduction to growth. Here we tested this hypothesis by examining the genetic change and correlated responses of reproductive traits as a result of selection for timber yield in the tree Pinus pinaster. Phenotypic selection was carried out in a natural population, and progenies from selected trees were compared with those of control trees in a common garden experiment. According to expectations, we detected a genetic change in important life-history traits due to selection. Specifically, threshold sizes for reproduction were much higher and reproductive investment relative to size significantly lower in the selected progenies just after a single artificial selection event. Our study helps to define the domestication syndrome in exploited forest trees and shows that changes affecting developmental pathways are relevant in domestication processes of long-lived plants. PMID:25926884

Periodic regulation of expression of genes for kisspeptin, gonadotropin-inhibitory hormone and their receptors in the grass puffer: Implications in seasonal, daily and lunar rhythms of reproduction.

Science.gov (United States)

Ando, Hironori; Shahjahan, Md; Kitahashi, Takashi

2018-04-03

The seasonal, daily and lunar control of reproduction involves photoperiodic, circadian and lunar changes in the activity of kisspeptin, gonadotropin-inhibitory hormone (GnIH) and gonadotropin-releasing hormone (GnRH) neurons. These changes are brought through complex networks of light-, time- and non-photic signal-dependent control mechanisms, which are mostly unknown at present. The grass puffer, Takifugu alboplumbeus, a semilunar spawner, provides a unique and excellent animal model to assess this question because its spawning is synchronized with seasonal, daily and lunar cycles. In the diencephalon, the genes for kisspeptin, GnIH and their receptors showed similar expression patterns with clear seasonal and daily oscillations, suggesting that they are regulated by common mechanisms involving melatonin, circadian clock and water temperature. For implications in semilunar-synchronized spawning rhythm, melatonin receptor genes showed ultradian oscillations in expression with the period of 14.0-15.4 h in the pineal gland. This unique ultradian rhythm might be driven by circatidal clock. The possible circatidal clock and circadian clock in the pineal gland may cooperate to drive circasemilunar rhythm to regulate the expression of the kisspeptin, GnIH and their receptor genes. On the other hand, high temperature (over 28 °C) conditions, under which the expression of the kisspeptin and its receptor genes is markedly suppressed, may provide an environmental signal that terminates reproduction at the end of breeding period. Taken together, the periodic regulation of the kisspeptin, GnIH and their receptor genes by melatonin, circadian clock and water temperature may be important in the precisely-timed spawning of the grass puffer. Copyright © 2018 Elsevier Inc. All rights reserved.

A transcription elongation factor that links signals from the reproductive system to lifespan extension in Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Arjumand Ghazi

2009-09-01

Full Text Available In Caenorhabditis elegans and Drosophila melanogaster, the aging of the soma is influenced by the germline. When germline-stem cells are removed, aging slows and lifespan is increased. The mechanism by which somatic tissues respond to loss of the germline is not well-understood. Surprisingly, we have found that a predicted transcription elongation factor, TCER-1, plays a key role in this process. TCER-1 is required for loss of the germ cells to increase C. elegans' lifespan, and it acts as a regulatory switch in the pathway. When the germ cells are removed, the levels of TCER-1 rise in somatic tissues. This increase is sufficient to trigger key downstream events, as overexpression of tcer-1 extends the lifespan of normal animals that have an intact reproductive system. Our findings suggest that TCER-1 extends lifespan by promoting the expression of a set of genes regulated by the conserved, life-extending transcription factor DAF-16/FOXO. Interestingly, TCER-1 is not required for DAF-16/FOXO to extend lifespan in animals with reduced insulin/IGF-1 signaling. Thus, TCER-1 specifically links the activity of a broadly deployed transcription factor, DAF-16/FOXO, to longevity signals from reproductive tissues.

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.

Patient monitoring in Polish assisted reproductive technology centres

Directory of Open Access Journals (Sweden)

Anna Krawczak

2016-12-01

Full Text Available In 2014, the Polish non-governmental patient association ‘Our Stork’ (Nasz Bocian introduced the ‘Patient monitoring in ART centres’ research project to gather previously unrecorded information on the situation of infertile people and the provision of assisted reproductive treatment in Poland. When the research project began, assisted reproductive treatment centres were unregulated by the state, a situation that had existed for more than 28 years following the birth of the first Polish test-tube baby in 1987. Patients signed civil contracts, remaining unprotected in terms of safety of treatment and recognition of their rights, and their presumed social position was described by doctors as ‘disciplined patients’ – a reflection of what Michele Foucault described as biopolitics. The research project comprised patient questionnaires (responses from 722 patients provided the basis for the document ‘Patient Recommendations in Infertility Treatment’, analysis of civil contracts and their accuracy in the context of patients’ legal rights in Poland, and in-depth interviews with assisted reproductive treatment centres’ owners, doctors, midwives, and patients to explore patient care. The data reveal that there is a lack of patient-centred care among doctors and medical staff in Poland and that following the passing into law of the 2015 Infertility Act, which introduced state regulation of assisted reproductive treatment centres, the situation for patients worsened.

The New Rich and Their Unplanned Births: Stratified Reproduction under China's Birth-planning Policy.

Science.gov (United States)

Shi, Lihong

2017-12-01

This article explores the creation and ramifications of a stratified reproductive system under China's state control of reproduction. Within this system, an emerging group of "new rich" are able to circumvent birth regulations and have unplanned births because of their financial capabilities and social networks. While China's birth-planning policy is meant to be enforced equally for all couples, the unequal access to wealth and bureaucratic power as a result of China's widening social polarization has created disparate reproductive rights and experiences. This article identifies three ways in which reproductive privileges are created. It further explores how a stratified reproductive system under state population control reinforces social polarization. While many socially marginalized couples are unable to register their unplanned children for citizenship status and social benefits, the new rich are able to legitimate their births and transfer their privilege and status to their children, thus reproducing a new generation of elites. © 2016 by the American Anthropological Association.

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 ...

Event-by-Event Simulation of Induced Fission

Energy Technology Data Exchange (ETDEWEB)

Vogt, R; Randrup, J

2007-12-13

We are developing a novel code that treats induced fission by statistical (or Monte-Carlo) simulation of individual decay chains. After its initial excitation, the fissionable compound nucleus may either deexcite by evaporation or undergo binary fission into a large number of fission channels each with different energetics involving both energy dissipation and deformed scission prefragments. After separation and Coulomb acceleration, each fission fragment undergoes a succession of individual (neutron) evaporations, leading to two bound but still excited fission products (that may further decay electromagnetically and, ultimately, weakly), as well as typically several neutrons. (The inclusion of other possible ejectiles is planned.) This kind of approach makes it possible to study more detailed observables than could be addressed with previous treatments which have tended to focus on average quantities. In particular, any type of correlation observable can readily be extracted from a generated set of events. With a view towards making the code practically useful in a variety of applications, emphasis is being put on making it numerically efficient so that large event samples can be generated quickly. In its present form, the code can generate one million full events in about 12 seconds on a MacBook laptop computer. The development of this qualitatively new tool is still at an early stage and quantitative reproduction of existing data should not be expected until a number of detailed refinement have been implemented.

Event-by-Event Simulation of Induced Fission

Science.gov (United States)

Vogt, Ramona; Randrup, Jørgen

2008-04-01

We are developing a novel code that treats induced fission by statistical (or Monte-Carlo) simulation of individual decay chains. After its initial excitation, the fissionable compound nucleus may either de-excite by evaporation or undergo binary fission into a large number of fission channels each with different energetics involving both energy dissipation and deformed scission pre-fragments. After separation and Coulomb acceleration, each fission fragment undergoes a succession of individual (neutron) evaporations, leading to two bound but still excited fission products (that may further decay electromagnetically and, ultimately, weakly), as well as typically several neutrons. (The inclusion of other possible ejectiles is planned.) This kind of approach makes it possible to study more detailed observables than could be addressed with previous treatments which have tended to focus on average quantities. In particular, any type of correlation observable can readily be extracted from a generated set of events. With a view towards making the code practically useful in a variety of applications, emphasis is being put on making it numerically efficient so that large event samples can be generated quickly. In its present form, the code can generate one million full events in about 12 seconds on a MacBook laptop computer. The development of this qualitatively new tool is still at an early stage and quantitative reproduction of existing data should not be expected until a number of detailed refinement have been implemented.

Event-by-Event Simulation of Induced Fission

International Nuclear Information System (INIS)

Vogt, Ramona; Randrup, Joergen

2008-01-01

We are developing a novel code that treats induced fission by statistical (or Monte-Carlo) simulation of individual decay chains. After its initial excitation, the fissionable compound nucleus may either de-excite by evaporation or undergo binary fission into a large number of fission channels each with different energetics involving both energy dissipation and deformed scission pre-fragments. After separation and Coulomb acceleration, each fission fragment undergoes a succession of individual (neutron) evaporations, leading to two bound but still excited fission products (that may further decay electromagnetically and, ultimately, weakly), as well as typically several neutrons. (The inclusion of other possible ejectiles is planned.) This kind of approach makes it possible to study more detailed observables than could be addressed with previous treatments which have tended to focus on average quantities. In particular, any type of correlation observable can readily be extracted from a generated set of events. With a view towards making the code practically useful in a variety of applications, emphasis is being put on making it numerically efficient so that large event samples can be generated quickly. In its present form, the code can generate one million full events in about 12 seconds on a MacBook laptop computer. The development of this qualitatively new tool is still at an early stage and quantitative reproduction of existing data should not be expected until a number of detailed refinement have been implemented

Event-by-Event Simulation of Induced Fission

International Nuclear Information System (INIS)

Vogt, R; Randrup, J

2007-01-01

We are developing a novel code that treats induced fission by statistical (or Monte-Carlo) simulation of individual decay chains. After its initial excitation, the fissionable compound nucleus may either deexcite by evaporation or undergo binary fission into a large number of fission channels each with different energetics involving both energy dissipation and deformed scission prefragments. After separation and Coulomb acceleration, each fission fragment undergoes a succession of individual (neutron) evaporations, leading to two bound but still excited fission products (that may further decay electromagnetically and, ultimately, weakly), as well as typically several neutrons. (The inclusion of other possible ejectiles is planned.) This kind of approach makes it possible to study more detailed observables than could be addressed with previous treatments which have tended to focus on average quantities. In particular, any type of correlation observable can readily be extracted from a generated set of events. With a view towards making the code practically useful in a variety of applications, emphasis is being put on making it numerically efficient so that large event samples can be generated quickly. In its present form, the code can generate one million full events in about 12 seconds on a MacBook laptop computer. The development of this qualitatively new tool is still at an early stage and quantitative reproduction of existing data should not be expected until a number of detailed refinement have been implemented

Safeguards Summary Event List (SSEL)

International Nuclear Information System (INIS)

1983-02-01

The Safeguards Summary Event List (SSEL) provides brief summaries of several hundred safeguards-related events involving nuclear material or facilities regulated by the US Nuclear Regulatory Commission (NRC). Events are described under the categories of bomb-related, intrusion, missing and/or allegedly stolen, transportation, vandalism, arson, firearms, radiological sabotage and miscellaneous. The information contained in the event descriptions is derived primarily from official NRC reporting channels

Safeguards Summary Event List (SSEL)

International Nuclear Information System (INIS)

1982-07-01

The Safeguards Summary Event List (SSEL) provides brief summaries of several hundred safeguards-related events involving nuclear material or facilities regulated by the US Nuclear Regulatory Commission (NRC). Events are described under the categories of bomb-related, intrusion, missing and/or allegedly stolen, transportation, vandalism, arson, firearms, sabotage and miscellaneous. The information contained in the event descriptions is derived primarily from official NRC reporting channels

Different aspects of reproduction strategies in crayfish: A review

Directory of Open Access Journals (Sweden)

Yazicioglu B.

2016-01-01

Full Text Available Study of the reproductive strategy of crayfish species is of great importance in the current astacological world. Crayfish are among the largest freshwater invertebrates, and as keystone species, they are able to regulate the structure of the benthic fauna in the freshwaters, demonstrating different ecological strategies and life spans ranging up to 20+ years. In order to bring together the various pieces of information related to this issue, this overview of published scientific reports was conducted. The majority of crayfish species studied show sexual dimorphism, with approximately equal numbers of males and females. However, over some decades numerous observations have been made for a few species that may have different modes of reproduction, such as hermaphroditism or intersex (e.g. Cherax quadricarinatus, Samastacus spinifrons, Parastacus virilastacus and Pacifastacus leniusculus and parthenogenesis (only Procambarus fallax f. virginalis. A recent study showed a new case of parthenogenesis as apomictic parthenogenesis (only Orconectes limosus. In addition, there are many investigations into the reproduction biology of crayfish, including using eyestalk ablation or androgenic gland ablation under various lab conditions and hybridization under natural conditions (e.g. Astacus astacus X Astacus leptodactylus, Orconectes rusticus X Orconectes propinquus. There are also some chemical factors which could possibly affect the reproduction system of crayfish in the wild.

Seasonal variation in human reproduction: environmental factors.

Science.gov (United States)

Bronson, F H

1995-06-01

Almost all human populations exhibit seasonal variation in births, owing mostly to seasonal variation in the frequency of conception. This review focuses on the degree to which environmental factors like nutrition, temperature and photoperiod contribute to these seasonal patterns by acting directly on the reproductive axis. The reproductive strategy of humans is basically that of the apes: Humans have the capacity to reproduce continuously, albeit slowly, unless inhibited by environmental influences. Two, and perhaps three, environmental factors probably act routinely as seasonal inhibitors in some human populations. First, it seems likely that ovulation is regulated seasonally in populations experiencing seasonal variation in food availability. More specifically, it seems likely that inadequate food intake or the increased energy expenditure required to obtain food, or both, can delay menarche, suppress the frequency of ovulation in the nonlactating adult, and prolong lactational amenorrhea in these populations on a seasonal basis. This action is most easily seen in tropical subsistence societies where food availability often varies greatly owing to seasonal variation in rainfall; hence births in these populations often correlate with rainfall. Second, it seems likely that seasonally high temperatures suppress spermatogenesis enough to influence the incidence of fertilization in hotter latitudes, but possibly only in males wearing clothing that diminishes scrotal cooling. Since most of our knowledge about this phenomenon comes from temperate latitudes, the sensitivity of spermatogenesis in both human and nonhuman primates to heat in the tropics needs further study. It is quite possible that high temperatures suppress ovulation and early embryo survival seasonally in some of these same populations. Since we know less than desired about the effect of heat stress on ovulation and early pregnancy in nonhuman mammals, and nothing at all about it in humans or any of the

Dietary choice for a balanced nutrient intake increases the mean and reduces the variance in the reproductive performance of male and female cockroaches.

Science.gov (United States)

Bunning, Harriet; Bassett, Lee; Clowser, Christina; Rapkin, James; Jensen, Kim; House, Clarissa M; Archer, Catharine R; Hunt, John

2016-07-01

Sexual selection may cause dietary requirements for reproduction to diverge across the sexes and promote the evolution of different foraging strategies in males and females. However, our understanding of how the sexes regulate their nutrition and the effects that this has on sex-specific fitness is limited. We quantified how protein (P) and carbohydrate (C) intakes affect reproductive traits in male (pheromone expression) and female (clutch size and gestation time) cockroaches (Nauphoeta cinerea). We then determined how the sexes regulate their intake of nutrients when restricted to a single diet and when given dietary choice and how this affected expression of these important reproductive traits. Pheromone levels that improve male attractiveness, female clutch size and gestation time all peaked at a high daily intake of P:C in a 1:8 ratio. This is surprising because female insects typically require more P than males to maximize reproduction. The relatively low P requirement of females may reflect the action of cockroach endosymbionts that help recycle stored nitrogen for protein synthesis. When constrained to a single diet, both sexes prioritized regulating their daily intake of P over C, although this prioritization was stronger in females than males. When given the choice between diets, both sexes actively regulated their intake of nutrients at a 1:4.8 P:C ratio. The P:C ratio did not overlap exactly with the intake of nutrients that optimized reproductive trait expression. Despite this, cockroaches of both sexes that were given dietary choice generally improved the mean and reduced the variance in all reproductive traits we measured relative to animals fed a single diet from the diet choice pair. This pattern was not as strong when compared to the single best diet in our geometric array, suggesting that the relationship between nutrient balancing and reproduction is complex in this species.

Parasite dispersal risk tolerance is mediated by its reproductive value.

Science.gov (United States)

Nolan, Maxcy P; Delaplane, Keith S

2017-10-01

Parasite dispersal theory draws heavily upon epidemiological SIR models in which host status (susceptible (S), infected (I), or recovered (R)) is used to study parasite dispersal evolution. In contrast to these extrinsically host-centric drivers, in this study we focus on an intrinsic driver, the parasite's reproductive value (predicted future offspring) as a regulator of the extent to which the individual will engage in risky dispersal behaviour. As a model system we use the honeybee Apis mellifera and its ectoparasite, the mite Varroa destructor . Mite reproduction happens exclusively inside cells of bee brood, and newly emerged fecund mites may parasitize either a homocolonial brood cell (low risk dispersal) or emigrate to a new bee colony via phoretic attachment to mature forager bees (high risk dispersal). In an empirical bioassay, prepartum mites (high reproductive value) and postpartum mites (low reproductive value) were offered a choice of newly emerged homocolonial worker bees (low risk), homocolonial pollen forager bees (high risk), or heterocolonial pollen foragers (high risk). A preference for newly emerged bees was earlier and more strongly sustained among prepartum mites. This suggests comparatively greater dispersal risk tolerance among postpartum mites with lower reproductive value. A dangerous bid for dispersal may be adaptive if the individual has already successfully reproduced and the rewards for successful dispersal are sufficiently large.

PHEROMONAL MODULATION OF REPRODUCTIVE FUNCTION IN MAMMALS

Directory of Open Access Journals (Sweden)

Matthieu Keller

2011-11-01

Full Text Available Social olfactory signals, often known as pheromones, are powerful regulators of reproductive function. These chemosignals can be detected by two olfactory systems, namely the main or the accessory olfactory systems. While initially anatomically segregated, both systems converge functionally as they can detect and process overlapping sets of chemosignals. This convergence also takes place at the level of their central projections in the hypothalamus. It is probably at this level that future investigations will be needed. Indeed, if the physiology of both olfactory system and reproductive function are now quite well characterized, the interrelation between both systems is unclear. Among the many cell populations that can serve as targets or relays for the pheromonal information in the hypothalamus are GnRH cells or the recently discovered Kispeptin population which have been showed to be activated after pheromonal activation. However, many works will be needed before having a definitive picture.

The 3rd international conference on reproductive immunology in Shanghai: September 27-29, 2013. Shanghai, China.

Science.gov (United States)

Du, MeiRong; Piao, HaiLan; Li, DaJin

2014-03-01

After the first and second international conferences on reproductive immunology held by Dr. DaJin Li in Shanghai, the related investigators all over the world hope to get together to share their latest findings with each other. Drs. DaJin Li and MeiRong Du sponsored and organized the third international conference on reproductive immunology at the Obstetrics and Gynecology Hospital affiliated with Fudan University, Shanghai, China, in the autumn of 2013. This congress brought together more than 100 International and National investigators representing a wide range of scientific disciplines. All the investigators actively work on reproductive immunology using human or large and small animal models. A range of reproductive immunological topics including the maternal-fetal immune regulation, reproductive tract mucosal immunology, immunocontraception, and pregnancy complications were highlighted and discussed in this conference. This conference supplied a good platform for the international reproductive immunologists to exchange their latest study progression and discuss the development direction of reproductive immunology in the near future. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Reproductive health and access to healthcare facilities: risk factors for depression and anxiety in women with an earthquake experience.

Science.gov (United States)

Anwar, Jasim; Mpofu, Elias; Matthews, Lynda R; Shadoul, Ahmed Farah; Brock, Kaye E

2011-06-30

The reproductive and mental health of women contributes significantly to their overall well-being. Three of the eight Millennium Development Goals are directly related to reproductive and sexual health while mental disorders make up three of the ten leading causes of disease burden in low and middle-income countries. Among mental disorders, depression and anxiety are two of the most prevalent. In the context of slower progress in achieving Millennium Development Goals in developing countries and the ever-increasing man-made and natural disasters in these areas, it is important to understand the association between reproductive health and mental health among women with post-disaster experiences. This was a cross-sectional study with a sample of 387 women of reproductive age (15-49 years) randomly selected from the October 2005 earthquake affected areas of Pakistan. Data on reproductive health was collected using the Centers for Disease Control reproductive health assessment toolkit. Depression and anxiety were measured using the Hopkins Symptom Checklist-25, while earthquake experiences were captured using the Harvard Trauma Questionnaire. The association of either depression or anxiety with socio-demographic variables, earthquake experiences, reproductive health and access to health facilities was estimated using multivariate logistic regression. Post-earthquake reproductive health events together with economic deprivation, lower family support and poorer access to health care facilities explained a significant proportion of differences in the experiencing of clinical levels of depression and anxiety. For instance, women losing resources for subsistence, separation from family and experiencing reproductive health events such as having a stillbirth, having had an abortion, having had abnormal vaginal discharge or having had genital ulcers, were at significant risk of depression and anxiety. The relationship between women's post-earthquake mental health and

Safeguards Summary Event List (SSEL)

International Nuclear Information System (INIS)

1984-03-01

The Safeguards Summary Event List (SSEL) provides brief summaries of several hundred safeguards-related events involving nuclear material or facilities regulated by the U.S. Nuclear Regulatory Commission (NRC). Events are described under the categories of bomb-related, intrusion, missing and/or allegedly stolen, transportation, tampering/vandalism, arson, firearms, radiological sabotage and miscellaneous. The information contained in the event descriptions is derived primarily from official NRC reporting channels

The role of the molecular chaperone heat shock protein A2 (HSPA2 in regulating human sperm-egg recognition

Directory of Open Access Journals (Sweden)

Brett Nixon

2015-01-01

Full Text Available One of the most common lesions present in the spermatozoa of human infertility patients is an idiopathic failure of sperm-egg recognition. Although this unique cellular interaction can now be readily by-passed by assisted reproductive strategies such as intracytoplasmic sperm injection (ICSI, recent large-scale epidemiological studies have encouraged the cautious use of this technology and highlighted the need for further research into the mechanisms responsible for defective sperm-egg recognition. Previous work in this field has established that the sperm domains responsible for oocyte interaction are formed during spermatogenesis prior to being dynamically modified during epididymal maturation and capacitation in female reproductive tract. While the factors responsible for the regulation of these sequential maturational events are undoubtedly complex, emerging research has identified the molecular chaperone, heat shock protein A2 (HSPA2, as a key regulator of these events in human spermatozoa. HSPA2 is a testis-enriched member of the 70 kDa heat shock protein family that promotes the folding, transport, and assembly of protein complexes and has been positively correlated with in vitro fertilization (IVF success. Furthermore, reduced expression of HSPA2 from the human sperm proteome leads to an impaired capacity for cumulus matrix dispersal, sperm-egg recognition and fertilization following both IVF and ICSI. In this review, we consider the evidence supporting the role of HSPA2 in sperm function and explore the potential mechanisms by which it is depleted in the spermatozoa of infertile patients. Such information offers novel insights into the molecular mechanisms governing sperm function.

76 FR 38077 - Special Local Regulations and Safety Zones; Recurring Events in Captain of the Port New York Zone

Science.gov (United States)

2011-06-29

...: All Zone. waters of Long Island Sound in an area bound by the following points: 40[deg]51'43.5'' N 073... Zone. located in approximate position 40[deg]51'52'' N 073[deg]56'24'' W (NAD 1983), approximately 1750...] RIN 1625-AA00; 1625-AA08 Special Local Regulations and Safety Zones; Recurring Events in Captain of...

Reproductive Disorders in Snakes.

Science.gov (United States)

Di Girolamo, Nicola; Selleri, Paolo

2017-05-01

Reproduction of snakes is one of the challenging aspects of herpetology medicine. Due to the complexity of reproduction, several disorders may present before, during, or after this process. This article describes the physical examination, and radiographic, ultrasonographic, and endoscopic findings associated with reproductive disorders in snakes. Surgical techniques used to resolve reproductive disorders in snakes are described. Finally, common reproductive disorders in snakes are individually discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

A MATHEMATICAL MODEL FOR THE KINETICS OF THE MALE REPRODUCTIVE ENDOCRINE SYSTEM

Science.gov (United States)

In this presentation a model for the hormonal regulation of the reproductive endocrine system in the adult male rat will be discussed. The model includes a description of the kinetics of the androgenic hormones testosterone and dihydrotestosterone, as well as the receptor-mediate...

Toll-like receptors and their role in animal reproduction.

Science.gov (United States)

Kannaki, T R; Shanmugam, M; Verma, P C

2011-05-01

Toll-like receptors (TLRs) are evolutionarily conserved innate immune receptors that recognize pathogen specific molecular pattern (PAMPs) in an efficient, non-self-reactive manner and initiate specific immune signaling that culminates in triggering antigen-specific adaptive responses. Different TLR genes in domestic animal species have been characterized and accumulating evidence from recent studies indicates an extended role for TLR signaling in reproductive physiology. In females, TLRs have been implicated in the regulation of ovulation, fertilization, gestation and parturition, as well as in pathological conditions such as endometritis and mastitis. In males, TLRs play a role in steroidogenesis and spermatogenesis. Use of TLR agonists has also been shown to be effective in the treatment of certain reproductive tract infections. Moreover, gene polymorphisms in TLRs have been associated with mastitis providing evidence that TLRs can potentially be exploited as markers in future breeding programs. The aim of this review is to provide a comprehensive treatise on role of TLRs in male and female reproductive physiology and associated pathology in domestic livestock. Copyright © 2011. Published by Elsevier B.V.

Hormone levels predict individual differences in reproductive success in a passerine bird.

Science.gov (United States)

Ouyang, Jenny Q; Sharp, Peter J; Dawson, Alistair; Quetting, Michael; Hau, Michaela

2011-08-22

Hormones mediate major physiological and behavioural components of the reproductive phenotype of individuals. To understand basic evolutionary processes in the hormonal regulation of reproductive traits, we need to know whether, and during which reproductive phases, individual variation in hormone concentrations relates to fitness in natural populations. We related circulating concentrations of prolactin and corticosterone to parental behaviour and reproductive success during both the pre-breeding and the chick-rearing stages in both individuals of pairs of free-living house sparrows, Passer domesticus. Prolactin and baseline corticosterone concentrations in pre-breeding females, and prolactin concentrations in pre-breeding males, predicted total number of fledglings. When the strong effect of lay date on total fledgling number was corrected for, only pre-breeding baseline corticosterone, but not prolactin, was negatively correlated with the reproductive success of females. During the breeding season, nestling provisioning rates of both sexes were negatively correlated with stress-induced corticosterone levels. Lastly, individuals of both sexes with low baseline corticosterone before and high baseline corticosterone during breeding raised the most offspring, suggesting that either the plasticity of this trait contributes to reproductive success or that high parental effort leads to increased hormone concentrations. Thus hormone concentrations both before and during breeding, as well as their seasonal dynamics, predict reproductive success, suggesting that individual variation in absolute concentrations and in plasticity is functionally significant, and, if heritable, may be a target of selection.

An individual reproduction model sensitive to milk yield and body condition in Holstein dairy cows.

Science.gov (United States)

Brun-Lafleur, L; Cutullic, E; Faverdin, P; Delaby, L; Disenhaus, C

2013-08-01

To simulate the consequences of management in dairy herds, the use of individual-based herd models is very useful and has become common. Reproduction is a key driver of milk production and herd dynamics, whose influence has been magnified by the decrease in reproductive performance over the last decades. Moreover, feeding management influences milk yield (MY) and body reserves, which in turn influence reproductive performance. Therefore, our objective was to build an up-to-date animal reproduction model sensitive to both MY and body condition score (BCS). A dynamic and stochastic individual reproduction model was built mainly from data of a single recent long-term experiment. This model covers the whole reproductive process and is composed of a succession of discrete stochastic events, mainly calving, ovulations, conception and embryonic loss. Each reproductive step is sensitive to MY or BCS levels or changes. The model takes into account recent evolutions of reproductive performance, particularly concerning calving-to-first ovulation interval, cyclicity (normal cycle length, prevalence of prolonged luteal phase), oestrus expression and pregnancy (conception, early and late embryonic loss). A sensitivity analysis of the model to MY and BCS at calving was performed. The simulated performance was compared with observed data from the database used to build the model and from the bibliography to validate the model. Despite comprising a whole series of reproductive steps, the model made it possible to simulate realistic global reproduction outputs. It was able to well simulate the overall reproductive performance observed in farms in terms of both success rate (recalving rate) and reproduction delays (calving interval). This model has the purpose to be integrated in herd simulation models to usefully test the impact of management strategies on herd reproductive performance, and thus on calving patterns and culling rates.

A transcriptomics investigation into pine reproductive organ development.

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Niu, Shihui; Yuan, Huwei; Sun, Xinrui; Porth, Ilga; Li, Yue; El-Kassaby, Yousry A; Li, Wei

2016-02-01

The development of reproductive structures in gymnosperms is still poorly studied because of a lack of genomic information and useful genetic tools. The hermaphroditic reproductive structure derived from unisexual gymnosperms is an even less studied aspect of seed plant evolution. To extend our understanding of the molecular mechanism of hermaphroditism and the determination of sexual identity of conifer reproductive structures in general, unisexual and bisexual cones from Pinus tabuliformis were profiled for gene expression using 60K microarrays. Expression patterns of genes during progression of sexual cone development were analysed using RNA-seq. The results showed that, overall, the transcriptomes of male structures in bisexual cones were more similar to those of female cones. However, the expression of several MADS-box genes in the bisexual cones was similar to that of male cones at the more juvenile developmental stage, while despite these expression shifts, male structures of bisexual cones and normal male cones were histologically indistinguishable and cone development was continuous. This study represents a starting point for in-depth analysis of the molecular regulation of cone development and also the origin of hermaphroditism in pine. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

The survival–reproduction association becomes stronger when conditions are good

OpenAIRE

Robert, Alexandre; Bolton, Mark; Jiguet, Frédéric; Bried, Joël

2015-01-01

Positive covariations between survival and reproductive performance (S–R covariation) are generally interpreted in the context of fixed or dynamic demographic heterogeneity (i.e. persistent differences between individuals, or dynamic variation in resource acquisition), but the processes underlying covariations are still unknown. We used multi-event modelling to investigate how environmental and individual features influence S–R covariation patterns in a long-lived seabird, the Monteiro's stor...

Recrudescence mechanisms and gene expression profile of the reproductive tracts from chickens during the molting period.

Directory of Open Access Journals (Sweden)

Wooyoung Jeong

Full Text Available The reproductive system of chickens undergoes dynamic morphological and functional tissue remodeling during the molting period. The present study identified global gene expression profiles following oviductal tissue regression and regeneration in laying hens in which molting was induced by feeding high levels of zinc in the diet. During the molting and recrudescence processes, progressive morphological and physiological changes included regression and re-growth of reproductive organs and fluctuations in concentrations of testosterone, progesterone, estradiol and corticosterone in blood. The cDNA microarray analysis of oviductal tissues revealed the biological significance of gene expression-based modulation in oviductal tissue during its remodeling. Based on the gene expression profiles, expression patterns of selected genes such as, TF, ANGPTL3, p20K, PTN, AvBD11 and SERPINB3 exhibited similar patterns in expression with gradual decreases during regression of the oviduct and sequential increases during resurrection of the functional oviduct. Also, miR-1689* inhibited expression of Sp1, while miR-17-3p, miR-22* and miR-1764 inhibited expression of STAT1. Similarly, chicken miR-1562 and miR-138 reduced the expression of ANGPTL3 and p20K, respectively. These results suggest that these differentially regulated genes are closely correlated with the molecular mechanism(s for development and tissue remodeling of the avian female reproductive tract, and that miRNA-mediated regulation of key genes likely contributes to remodeling of the avian reproductive tract by controlling expression of those genes post-transcriptionally. The discovered global gene profiles provide new molecular candidates responsible for regulating morphological and functional recrudescence of the avian reproductive tract, and provide novel insights into understanding the remodeling process at the genomic and epigenomic levels.

An Ethical Analysis of Assisted Reproduction Providers' Websites in Pakistan.

Science.gov (United States)

Irshad, Ayesha; Werner-Felmayer, Gabriele

2016-07-01

Assisted reproductive technologies (ARTs) and reproductive genetic technologies (RGTs) are intertwined and coevolving. These technologies are increasingly used to fulfill socially and culturally framed requests, for example, "family balancing," or to enable postmenopausal women or homosexual couples to have genetically linked children. The areas of ART and RGT are replete with ethical issues, because different social practices and legal regulations, as well as economic inequalities within and among countries, create vulnerable groups and, therefore, the potential for exploitation. This article provides an overview of the ART and RGT landscape in Pakistan and analyzes the available online content addressing Pakistani citizens and international clients. We explored the topic in view of socioeconomic challenges in Pakistan, particularly deeply rooted poverty, lack of education, gender discrimination, and absence of regulation. As online information given by ART and RGT providers is readily available and could easily raise false hopes, make use of discriminatory statements with regard to women, and promote gender selection to meet sociocultural expectations, it should be subjected to quality control.

Reproductive medicine and the law: egg donation in Germany, Spain and other European countries.

Science.gov (United States)

Romeo Casabona, Carlos María; Paslack, Rainer; Simon, Jörgen W

2013-01-01

This paper analyzes the key legal issues raised by Reproductive Medicine practiced in Europe, with special attention to the rules prevailing in countries such as Germany and Spain. Thus, the paper involves a detailed study of the regulation in force in those countries, comparing their solutions with the rules adopted in other EU countries. It also highlights the high risk of com-modification in oocyte donation. In light of this, the differences between the laws of EU countries -some of them, very restrictive with prohibitions or requirements for recipient women and others more permissive with the use of reproductive technologies- can lead to a "reproductive tourism" between countries, as indeed is happening nowadays.

Adapting to extreme events related to natural variability and climate change: the imperative of coupling technology with strong regulation and governance.

Science.gov (United States)

Kythreotis, A P; Mercer, T G; Frostick, L E

2013-09-03

In recent years there has been an increase in extreme events related to natural variability (such as earthquakes, tsunamis and hurricanes) and climate change (such as flooding and more extreme weather). Developing innovative technologies is crucial in making society more resilient to such events. However, little emphasis has been placed on the role of human decision-making in maximizing the positive impacts of technological developments. This is exacerbated by the lack of appropriate adaptation options and the privatization of existing infrastructure, which can leave people exposed to increasing risk. This work examines the need for more robust government regulation and legislation to complement developments and innovations in technology in order to protect communities against such extreme events.

77 FR 8184 - Foreign Tax Credit Splitting Events

Science.gov (United States)

2012-02-14

... Foreign Tax Credit Splitting Events AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Notice of... these proposed regulations. The regulations affect taxpayers claiming foreign tax credits. Special... of the Federal Register.] Sec. 1.909-6 Pre-2011 foreign tax credit splitting events. [The text of...

Why cellular communication during plant reproduction is particularly mediated by CRP signalling.

Science.gov (United States)

Bircheneder, Susanne; Dresselhaus, Thomas

2016-08-01

Secreted cysteine-rich peptides (CRPs) represent one of the main classes of signalling peptides in plants. Whereas post-translationally modified small non-CRP peptides (psNCRPs) are mostly involved in signalling events during vegetative development and interactions with the environment, CRPs are overrepresented in reproductive processes including pollen germination and growth, self-incompatibility, gamete activation and fusion as well as seed development. In this opinion paper we compare the involvement of both types of peptides in vegetative and reproductive phases of the plant lifecycle. Besides their conserved cysteine pattern defining structural features, CRPs exhibit hypervariable primary sequences and a rapid evolution rate. As a result, CRPs represent a pool of highly polymorphic signalling peptides involved in species-specific functions during reproduction and thus likely represent key players to trigger speciation in plants by supporting reproductive isolation. In contrast, precursers of psNCRPs are proteolytically processed into small functional domains with high sequence conservation and act in more general processes. We discuss parallels in downstream processes of CRP signalling in both reproduction and defence against pathogenic fungi and alien pollen tubes, with special emphasis on the role of ROS and ion channels. In conclusion we suggest that CRP signalling during reproduction in plants has evolved from ancient defence mechanisms. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Neuropeptides linking the control of appetite with reproductive function in domestic animals

Science.gov (United States)

The occurrence of puberty and maintenance of normal reproductive cycles are regulated by secretion of gonadotropin hormones from the pituitary gland, which is dependent upon the pulsatile release of gonadotropin-releasing hormone (GnRH) from the hypothalamus. It is well established that secretion of...

Event rate and reaction time performance in ADHD: Testing predictions from the state regulation deficit hypothesis using an ex-Gaussian model.

Science.gov (United States)

Metin, Baris; Wiersema, Jan R; Verguts, Tom; Gasthuys, Roos; van Der Meere, Jacob J; Roeyers, Herbert; Sonuga-Barke, Edmund

2014-12-06

According to the state regulation deficit (SRD) account, ADHD is associated with a problem using effort to maintain an optimal activation state under demanding task settings such as very fast or very slow event rates. This leads to a prediction of disrupted performance at event rate extremes reflected in higher Gaussian response variability that is a putative marker of activation during motor preparation. In the current study, we tested this hypothesis using ex-Gaussian modeling, which distinguishes Gaussian from non-Gaussian variability. Twenty-five children with ADHD and 29 typically developing controls performed a simple Go/No-Go task under four different event-rate conditions. There was an accentuated quadratic relationship between event rate and Gaussian variability in the ADHD group compared to the controls. The children with ADHD had greater Gaussian variability at very fast and very slow event rates but not at moderate event rates. The results provide evidence for the SRD account of ADHD. However, given that this effect did not explain all group differences (some of which were independent of event rate) other cognitive and/or motivational processes are also likely implicated in ADHD performance deficits.

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.

The infra-value of human rights in the context of assisted regulation in México.

Science.gov (United States)

Esparza-Pérez, Rosa Verónica

Infertility represents a problem in the context of reproductive health; to treat it were developed the techniques of assisted human reproduction, despite medical advances, the practice of techniques is subject to medical, legal and ethical dysfunctions. In Mexico, since the late 1980s assisted reproduction clinics were set up in public and private sector hospitals; however, they do not yet have a legal framework to regulate them in a specific way, which causes human rights violations that could be avoided with adequate regulation. This article advances the need to provide Mexico with such regulation as a means of guaranteeing both human rights and the rights of physicians and other health workers involved in these techniques. Copyright: © 2017 SecretarÍa de Salud.

Extracellular signal-regulated kinase 1 and 2 are not required for GnRH neuron development and normal female reproductive axis function in mice.

Science.gov (United States)

Wierman, Margaret E; Xu, Mei; Pierce, A; Bliesner, B; Bliss, S P; Roberson, M S

2012-01-01

Selective deletion of extracellular signal-regulated kinase (ERK) 1 and ERK2 in the pituitary gonadotrope and ovarian granulosa cells disrupts female reproductive axis function. Thus, we asked if ERK1 and ERK2 are critical for GnRH neuron ontogeny or the central control of female reproductive function. GnRH-Cre-recombinase (Cre+) expressing mice were crossed with mice with a global deletion of ERK1 and a floxed ERK2 allele (Erk1-/Erk2fl/fl) to selectively delete ERK2 in GnRH neurons. Cre-recombinase mRNA was selectively expressed in the brain of Cre+ mice. GnRH neuron number and location were determined during embryogenesis and in the adult. GnRH neuron counts at E15 did not differ between experimental and control groups (1,198 ± 65 and 1,160 ± 80 respectively, p = NS). In adults, numbers of GnRH neurons in the GnRHCre+Erk1-/Erk2- mice (741 ± 157) were similar to those in controls (756 ± 7), without alteration in their distribution across the forebrain. ERK1 and 2 deficiency did not alter the timing of vaginal opening, age at first estrus, or estrous cyclicity. Although ERK1 and 2 are components of a dominant signaling pathway in GnRH neuronal cells that modulates survival and control of GnRH gene expression, other signaling pathways compensate for their deletion in vivo to allow GnRH neuron survival and targeting and normal onset of female sexual maturation and reproductive function. In contrast to effects at the pituitary and the ovary, ERK1 and ERK2 are dispensable at the level of the GnRH neuron. Copyright © 2011 S. Karger AG, Basel.

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

heterogeneity). There was also a significant improvement in the clinical pregnancy rate with use of LMWH (OR 1.61, 95% CI 1.03 to 2.53, three studies, 386 women, I(2) = 29%, very low quality evidence with low heterogeneity).However these findings should be interpreted with extreme caution as they were dependent upon the choice of statistical method: they were no longer statistically significant when a random-effects model was used.Adverse events were poorly reported in all included studies, with no comparative data available. However, LMWH did cause adverse effects including bruising, ecchymosis, bleeding, thrombocytopenia and allergic reactions. It appeared that these adverse effects were increased if heparin therapy was used over a longer duration. The results of this Cochrane review of three randomised controlled trials with a total of 386 women suggested that peri-implantation LMWH in assisted reproduction treatment (ART) cycles may improve the live birth rate in women undergoing assisted reproduction. However, these results were dependent on small low quality studies with substantial heterogeneity, and were sensitive to the choice of statistical model. There were side effects reported with use of heparin, including bruising and bleeding, and no reliable data on long-term effects. The results do not justify this use of heparin outside well-conducted research trials.These findings need to be further investigated with well-designed, adequately powered, double-blind, randomised, placebo-controlled, multicentre trials. Further investigations could also focus on the effects of the local (uterine) and not systemic application of heparin during ART.

Marijuana, the Endocannabinoid System and the Female Reproductive System

OpenAIRE

Brents, Lisa K.

2016-01-01

Marijuana use among women is highly prevalent, but the societal conversation on marijuana rarely focuses on how marijuana affects female reproduction and endocrinology. This article reviews the current scientific literature regarding marijuana use and hypothalamic-pituitary-ovarian (HPO) axis regulation, ovarian hormone production, the menstrual cycle, and fertility. Evidence suggests that marijuana can reduce female fertility by disrupting hypothalamic release of gonadotropin releasing hormo...

Voice and Handgrip Strength Predict Reproductive Success in a Group of Indigenous African Females

Science.gov (United States)

Sorokowska, Agnieszka; Sorokowski, Piotr; Mberira, Mara; Bartels, Astrid; Gallup, Gordon G.

2012-01-01

Evolutionary accounts of human traits are often based on proxies for genetic fitness (e.g., number of sex partners, facial attractiveness). Instead of using proxies, actual differences in reproductive success is a more direct measure of Darwinian fitness. Certain voice acoustics such as fundamental frequency and measures of health such as handgrip strength correlate with proxies of fitness, yet there are few studies showing the relation of these traits to reproduction. Here, we explore whether the fundamental frequency of the voice and handgrip strength account for differences in actual reproduction among a population of natural fertility humans. Our results show that both fundamental frequency and handgrip strength predict several measures of reproductive success among a group of indigenous Namibian females, particularly amongst the elderly, with weight also predicting reproductive outcomes among males. These findings demonstrate that both hormonally regulated and phenotypic quality markers can be used as measures of Darwinian fitness among humans living under conditions that resemble the evolutionary environment of Homo sapiens. We also argue that these findings provide support for the Grandmother Hypothesis. PMID:22870251

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.

Fake it till you make it: Policymaking and assisted human reproduction in Canada.

Science.gov (United States)

Baylis, Françoise; Downie, Jocelyn; Snow, Dave

2014-06-01

The Assisted Human Reproduction Act (AHR Act) came into effect in 2004. The AHR Act stipulates in s.12 that no reimbursement of expenditures incurred in the course of donating gametes, maintaining or transporting in vitro embryos, or providing surrogacy services is permitted, except in accordance with the regulations and with receipts. Ten years later, Health Canada still has not drafted the regulations governing reimbursement. Section 12 is therefore still not in force. Health Canada and others have asserted that there is a Health Canada policy on reimbursement and that reimbursement with receipts is legally permissible. We dispute the existence of such a policy and its legitimacy (if it exists). We also challenge the decision by Health Canada not to produce regulations and thereby make it possible for Parliament to bring s.12 into force. This intentional lack of action is worrisome on at least two fronts. First, it sidesteps the processes required for regulations and thereby ducks the Parliamentary oversight very deliberately built into the AHR Act. Second, it leaves Canadians who provide and who access assisted human reproduction uncertain about what is and is not permitted, and therefore fearful of, or at risk of, prosecution. We conclude that Health Canada should take the steps necessary to put regulations in front of Parliament so that Parliament will then be able to pass regulations and bring s.12 into force. Canadians should demand no less.

Reproductive demography of a temperate protogynous and herbivorous fish, Odax pullus (Labridae, Odacini)

KAUST Repository

Laman Trip, Elizabeth; Raubenheimer, David; Clements, Kendall D.; Choat, John Howard

2011-01-01

A common view is that, in marine fishes, herbivory and sex change are subject to physiological constraints at high latitudes, which are likely to affect growth rates and reproductive outputs. The present study examines the reproductive demography of Odax pullus, an herbivorous and protogynous species of temperate New Zealand. We establish an otolith-based methodology for age estimation and investigate sex-specific growth, longevity and age-based reproductive events. Individuals achieved a maximum age of 11 years, reached 85% of adult body size (455mm FL) within the first 3.5 years of life, were sexually mature by the age of 1.11.5 years and changed sex at 2.83.5 years, indicating fast simultaneous somatic and reproductive growth. There was no significant difference in growth or body size between the sexes. Ovary weight of spawning females increased significantly with size and age, suggesting the presence of size- and age-fecundity skews underlying the absence of sex change in larger and older females. Testes of reproductively active males comprised less than 1% of bodyweight, suggesting pair-spawning and little sperm competition. The present study provides metrics to support comparisons of the demography of this temperate protogynous and herbivorous labrid across spatial or temporal strata. © CSIRO 2011.

Reproductive demography of a temperate protogynous and herbivorous fish, Odax pullus (Labridae, Odacini)

KAUST Repository

Laman Trip, Elizabeth

2011-03-07

A common view is that, in marine fishes, herbivory and sex change are subject to physiological constraints at high latitudes, which are likely to affect growth rates and reproductive outputs. The present study examines the reproductive demography of Odax pullus, an herbivorous and protogynous species of temperate New Zealand. We establish an otolith-based methodology for age estimation and investigate sex-specific growth, longevity and age-based reproductive events. Individuals achieved a maximum age of 11 years, reached 85% of adult body size (455mm FL) within the first 3.5 years of life, were sexually mature by the age of 1.11.5 years and changed sex at 2.83.5 years, indicating fast simultaneous somatic and reproductive growth. There was no significant difference in growth or body size between the sexes. Ovary weight of spawning females increased significantly with size and age, suggesting the presence of size- and age-fecundity skews underlying the absence of sex change in larger and older females. Testes of reproductively active males comprised less than 1% of bodyweight, suggesting pair-spawning and little sperm competition. The present study provides metrics to support comparisons of the demography of this temperate protogynous and herbivorous labrid across spatial or temporal strata. © CSIRO 2011.

Impact of supplementary feeding on reproductive success of white storks.

Directory of Open Access Journals (Sweden)

Roland Hilgartner

Full Text Available European white stork (Ciconia ciconia populations have been object to several conservation measures such as reintroduction programs, habitat improvement or supplementary feeding in the last decades. Although recent white stork censuses revealed an upward trend of most of the western populations, evaluations of the relative importance of certain conservation measures are still scarce or even lacking. In our study we analyzed the effect of supplementary feeding on the reproductive success of white storks in conjunction with other factors such as weather or nest site characteristics. We present data of 569 breeding events at 80 different nest sites located in variable distances to an artificial feeding site at Affenberg Salem (south-western Germany collected from 1990-2012. A multilevel Poisson regression revealed that in our study population (1 reproductive success was negatively affected by monthly precipitation in April, May and June, (2 pairs breeding on power poles had a lower reproductive success than pairs breeding on platforms or trees and (3 reproductive success was significantly higher in pairs breeding in close distance to the feeding site. The number of fledglings per nest decreased by 8% per kilometer distance to the feeding site. Our data suggest that supplementary feeding increases fledgling populations which may be a tool to attenuate population losses caused by factors such as habitat deterioration or unfavorable conditions in wintering habitats.

Vitamin D and male reproductive system.

Science.gov (United States)

Costanzo, Pablo R; Knoblovits, Pablo

2016-12-01

Vitamin D deficiency is a highly prevalent worldwide condition and affects people of all ages. The most important role of vitamin D is the regulation of intestinal calcium absorption and metabolism of calcium and phosphorus to maintain muscle and bone homeostasis. Furthermore, in recent years it has been discovered that the vitamin D receptor (VDR) is widely distributed in many organs and tissues where vitamin D can perform other actions that include the modulation of the immune response, insulin secretion, anti-proliferative effect on cells of vascular smooth muscle, modulation of the renin-angiotensin-aldosterone system and regulates cell growth in several organs. The VDR is widely distributed in the male reproductive system. Vitamin D induces changes in the spermatozoa's calcium and cholesterol content and in protein phosphorylation to tyrosine/threonine residues. These changes could be involved in sperm capacitation. Vitamin D seems to regulate aromatase expression in different tissues. Studies analyzing seasonal variations of sex steroids in male populations yield conflicting results. This is probably due to the wide heterogeneity of the populations included according to age, systemic diseases and obesity.

[Trauma & the reproductive lifecycle in women].

Science.gov (United States)

Born, Leslie; Phillips, Shauna Dae; Steiner, Meir; Soares, Claudio N

2005-10-01

Women are at significantly higher risk for developing post-traumatic stress disorder (PTSD) than men, resulting in increased psychosocial burden and healthcare related costs. Recent research has shown complex interactions between the impact of traumatic experiences, and the reproductive lifecycle in women. For example, women suffering from premenstrual dysphoric disorder (PMDD) who also report a history of sexual or physical abuse are more likely to present with different neuroendocrine reactivity to stressors, when compared to premenstrual dysphoric disorder subjects without prior history of trauma or abuse or non-premenstrual dysphoric disorder subjects. In addition, women with a history of abuse or trauma may experience re-emergence of symptoms during pregnancy. Lastly, females who experience miscarriage may present with even higher prevalence rates of post-traumatic stress disorder symptoms. In this manuscript we examine the existing data on gender differences in post-traumatic stress disorder, with particular focus on psychological and physiological factors that might be relevant to the development of symptoms after exposure to traumatic events associated with the reproductive life cycle. Current options available for the treatment of such symptoms, including group and counselling therapies and debriefing are critically reviewed.

Beyond reproduction: Semiotic perspectives on musical performance

Directory of Open Access Journals (Sweden)

Cook Nicholas

2014-01-01

Full Text Available The traditional musicological conception of performance is as the reproduction of pre-existing texts. This makes no allowance for the extent to which meaning emerges from the act of performance, and from the interactions between the various participants in performance events. A broadly semiotic approach focusses attention on such issues, and in this article I illustrate such an approach in terms of the communicative function of the mazurka ‘script’ and the role of performance gesture in conditioning musical meaning. I argue that, instead of thinking in terms of the reproduction of works, it is better to borrow Jeff Pressing’s term and think in terms of performances referencing scores, traditions, and other pre-existing entities: this way it is possible to conceptualise performances that range from the Werktreue ideology or tribute bands to parody or burlesque. Discourses of the relationship between works and performances are mirrored by those between performances and recordings, and consideration of the latter helps to clarify features shared by both: creativity, collaboration, and semiosis.

Safeguards summary event list (SSEL)

International Nuclear Information System (INIS)

1989-07-01

The Safeguards Summary Event List (SSEL) provides brief summaries of several hundred safeguards-related events involving nuclear material or facilities regulated by the US Nuclear Regulatory Commission (NRC). Because of public interest, also included are events reported involving byproduct material which is exempt from safeguards requirements. Events are described under the categories of bomb-related, intrusion, missing and/or allegedly stolen, transportation, tampering/vandalism, arson, firearms, radiological sabotage, nonradiological sabotage, alcohol and drugs, and miscellaneous. The information contained in the event descriptions is derived primarily from official NRC reporting channels

Safeguards Summary Event List (SSEL)

International Nuclear Information System (INIS)

Fadden, M.; Yardumian, J.

1993-07-01

The Safeguards Summary Event List provides brief summaries of hundreds of safeguards-related events involving nuclear material or facilities regulated by the US Nuclear Regulatory Commission. Events are described under the categories: Bomb-related, Intrusion, Missing/Allegedly Stolen, Transportation-related, Tampering/Vandalism, Arson, Firearms-related, Radiological Sabotage, Non-radiological Sabotage, and Miscellaneous. Because of the public interest, the Miscellaneous category also includes events reported involving source material, byproduct material, and natural uranium, which are exempt from safeguards requirements. Information in the event descriptions was obtained from official NRC sources

Striking a balance: conscientious objection and reproductive health care from the Colombian perspective.

Science.gov (United States)

Cabal, Luisa; Olaya, Monica Arango; Robledo, Valentina Montoya

2014-12-11

Conscientious Objection or conscientious refusal (CO) in access to reproductive health care is at the center of current legal debates worldwide. In countries such as the US and the UK, constitutional dilemmas surrounding CO in the context of reproductive health services reveal inadequate policy frameworks for balancing CO rights with women's rights to access contraception and abortion. The Colombian Constitutional Court's holistic jurisprudence regarding CO standards has applied international human rights norms so as to not only protect women's reproductive rights as fundamental rights, but to also introduce clear limits for the exercise of CO in health care settings. This paper reviews Latin American lines of regulation in Argentina, Uruguay, and Mexico City to argue that the Colombian Court's jurisprudence offers a strong guidance for future comprehensive policy approaches that aim to effectively balance tensions between CO and women's reproductive rights. Copyright © 2014 Cabal, Olaya, Robledo. 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.

Food supplementation and testosterone interact to influence reproductive behavior and immune function in Sceloporus graciosus.

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Ruiz, Mayté; French, Susannah S; Demas, Gregory E; Martins, Emília P

2010-02-01

The energetic resources in an organism's environment are essential for executing a wide range of life-history functions, including immunity and reproduction. Most energetic budgets, however, are limited, which can lead to trade-offs among competing functions. Increasing reproductive effort tends to decrease immunity in many cases, and increasing total energy via supplemental feedings can eliminate this effect. Testosterone (T), an important regulator of reproduction, and food availability are thus both potential factors regulating life-history processes, yet they are often tested in isolation of each other. In this study, we considered the effect of both food availability and elevated T on immune function and reproductive behavior in sagebrush lizards, Sceloporus graciosus, to assess how T and energy availability affect these trade-offs. We experimentally manipulated diet (via supplemental feedings) and T (via dermal patches) in males from a natural population. We determined innate immune response by calculating the bacterial killing capability of collected plasma exposed to Escherichia coli ex vivo. We measured reproductive behavior by counting the number of courtship displays produced in a 20-min sampling period. We observed an interactive effect of food availability and T-patch on immune function, with food supplementation increasing immunity in T-patch lizards. Additionally, T increased courtship displays in control food lizards. Lizards with supplemental food had higher circulating T than controls. Collectively, this study shows that the energetic state of the animal plays a critical role in modulating the interactions among T, behavior and immunity in sagebrush lizards and likely other species. Copyright 2009 Elsevier Inc. All rights reserved.

The Italian regulation on Assisted Reproductive Technologies facing the European Court of Human Rights: the case of Costa and Pavan v. Italy.

Science.gov (United States)

Penasa, Simone

2012-01-01

This article will describe the current legal framework on Assisted Reproduction Technology (ART) regulation in Italy, taking into account recent case-law derived from the implementation of the Law 40 of 2004 on ART. Special attention will be devoted to the case of Costa and Pavan v. Italy, recently decided by the Tenth Session of the European Court of Human Rights (ECtHR). In that decision, the European Court declared the incompatibility of the ban to pre-implantation genetic diagnosis introduced by the abovementioned Italian law on ART. The case will be analysed from a dual perspective. On the one hand, it will be considered in the light of the ECtHR case-law, in order to derive systematic aspects of continuity or discontinuity between the former and the latter2. On the other hand, the case will be considered in the light of its concrete and prospective impact on the Italian legal approach to ART regulation, considering especially the direct and indirect influence of the case: e.g., its possible utilisation by Italian judges when they are called upon to implement Law 40.

How endangered is sexual reproduction of high-mountain plants by summer frosts? Frost resistance, frequency of frost events and risk assessment

OpenAIRE

Ladinig, Ursula; Hacker, J?rgen; Neuner, Gilbert; Wagner, Johanna

2013-01-01

In temperate-zone mountains, summer frosts usually occur during unpredictable cold spells with snow-falls. Earlier studies have shown that vegetative aboveground organs of most high-mountain plants tolerate extracellular ice in the active state. However, little is known about the impact of frost on reproductive development and reproductive success. In common plant species from the European Alps (Cerastium uniflorum, Loiseleuria procumbens, Ranunculus glacialis, Rhododendron ferrugineum, Saxif...

Reproductive Outcomes Following Maternal Exposure to the Events of September 11, 2001, at the World Trade Center, in New York City.

Science.gov (United States)

Maslow, Carey B; Caramanica, Kimberly; Li, Jiehui; Stellman, Steven D; Brackbill, Robert M

2016-10-01

To estimate associations between exposure to the events of September 11, 2001, (9/11) and low birth weight (LBW), preterm delivery (PD), and small size for gestational age (SGA). We matched birth certificates filed in New York City for singleton births between 9/11 and the end of 2010 to 9/11-related exposure data provided by mothers who were World Trade Center Health Registry enrollees. Generalized estimating equations estimated associations between exposures and LBW, PD, and SGA. Among 3360 births, 5.8% were LBW, 6.5% were PD, and 9% were SGA. Having incurred at least 2 of 4 exposures, having performed rescue or recovery work, and probable 9/11-related posttraumatic stress disorder 2 to 3 years after 9/11 were associated with PD and LBW during the early study period. Disasters on the magnitude of 9/11 may exert effects on reproductive outcomes for several years. Women who are pregnant during and after a disaster should be closely monitored for physical and psychological sequelae. In utero and maternal disaster exposure may affect birth outcomes. Researchers studying effects of individual disasters should identify commonalities that may inform postdisaster responses to minimize disaster-related adverse birth outcomes.

Variations upon a theme: Australian lizards provide insights into the endocrine control of vertebrate reproductive cycles.

Science.gov (United States)

Jones, Susan M

2017-04-01

Australian lizards exhibit a broad array of different reproductive strategies and provide an extraordinary diversity and range of models with which to address fundamental problems in reproductive biology. Studies on lizards have frequently led to new insights into hormonal regulatory pathways or mechanisms of control, but we have detailed knowledge of the reproductive cycle in only a small percentage of known species. This review provides an overview and synthesis of current knowledge of the hormonal control of reproductive cycles in Australian lizards. Agamid lizards have provided useful models with which to test hypotheses about the hormonal regulation of the expression of reproductive behaviors, while research on viviparous skinks is providing insights into the evolution of the endocrine control of gestation. However, in order to better understand the potential risks that environmental factors such as climate change and endocrine disrupting chemicals pose to our fauna, better knowledge is required of the fundamental characteristics of the reproductive cycle in a broader range of lizard species. Copyright © 2015 Elsevier Inc. All rights reserved.

Linkage mapping of putative regulator genes of barley grain development characterized by expression profiling

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Wobus Ulrich

2009-01-01

Full Text Available Abstract Background Barley (Hordeum vulgare L. seed development is a highly regulated process with fine-tuned interaction of various tissues controlling distinct physiological events during prestorage, storage and dessication phase. As potential regulators involved within this process we studied 172 transcription factors and 204 kinases for their expression behaviour and anchored a subset of them to the barley linkage map to promote marker-assisted studies on barley grains. Results By a hierachical clustering of the expression profiles of 376 potential regulatory genes expressed in 37 different tissues, we found 50 regulators preferentially expressed in one of the three grain tissue fractions pericarp, endosperm and embryo during seed development. In addition, 27 regulators found to be expressed during both seed development and germination and 32 additional regulators are characteristically expressed in multiple tissues undergoing cell differentiation events during barley plant ontogeny. Another 96 regulators were, beside in the developing seed, ubiquitously expressed among all tissues of germinating seedlings as well as in reproductive tissues. SNP-marker development for those regulators resulted in anchoring 61 markers on the genetic linkage map of barley and the chromosomal assignment of another 12 loci by using wheat-barley addition lines. The SNP frequency ranged from 0.5 to 1.0 SNP/kb in the parents of the various mapping populations and was 2.3 SNP/kb over all eight lines tested. Exploration of macrosynteny to rice revealed that the chromosomal orders of the mapped putative regulatory factors were predominantly conserved during evolution. Conclusion We identified expression patterns of major transcription factors and signaling related genes expressed during barley ontogeny and further assigned possible functions based on likely orthologs functionally well characterized in model plant species. The combined linkage map and reference

Reproductive and larval cycle of the scallop Argopecten purpuratus (Ostreoida: Pectinidae, during El Niño-La Niña events and normal weather conditions in Antofagasta, Chile

Directory of Open Access Journals (Sweden)

Miguel Avendaño

2008-03-01

Full Text Available Seasonality, amplitude, and magnitude of spawning events were determined for Argopecten purpuratus in the La Rinconada marine reserve, Antofagasta, Chile, between December 1995 and January 2004. During the same period, samples of scallop larvae were obtained in vertical plankton hauls recovered within this reserve in an area routinely exposed to circular, gyre-like currents which helped retain the larvae within the bay. The reproduction of this population in normal or cool (e.g. "La Niña", 1998-2000 years occurred throughout the year, with a more active period between September and April, declining in June and August; this contrasted with the warmer "El Niño" oceanographic period of 1997-98 in which reproductive activity was more intense and prolonged throughout the entire year. The reproductive events in this population were mostly synchronous, although one asynchronous period occurred each year following the more intense March to May spawnings. This reproductive activity generated a continuous presence of larvae in the area in which no strict relation could be found between the intensities of spawning and numbers of larvae in the water. Larval presence was, however, generally correlated with active spawning periods. Important increases in larval numbers recorded at the end of 1999 and the beginning of 2003 were correlated with census data showing a higher percentage presence of broodstock over 90 mm in shell length during these years. An adequate stock of this size class is needed for a successful seed capture program in the reserve (for mass culture. Rev. Biol. Trop. 56 (1: 121-132. Epub 2008 March 31.Entre 1995 y 2004 se determinó, con el índice gonadosomático, el ciclo reproductivo de Argopecten purpuratus en La Rinconada, Antofagasta, Chile. Paralelamente se realizaron muestreos larvales mediante arrastres verticales de plancton. La reproducción, en años normales y fríos (La Niña, 1998-2000, ocurre todo el año, con un período m

Extreme hydrological events and the influence of reservoirs in a highly regulated river basin of northeastern Spain

Directory of Open Access Journals (Sweden)

S.M. Vicente-Serrano

2017-08-01

New hydrological insights: Results reveal a general reduction in the occurrence of extreme precipitation events in the Segre basin from 1950 to 2013, which corresponded to a general reduction in high flows measured at various gauged stations across the basin. While this study demonstrates spatial differences in the decrease of streamflow between the headwaters and the lower parts of the basin, mainly associated with changes in river regulation, there was no reduction in the frequency of the extraordinary floods. Changes in water management practices in the basin have significantly impacted the frequency, duration, and severity of hydrological droughts downstream of the main dams, as a consequence of the intense water regulation to meet water demands for irrigation and livestock farms. Nonetheless, the hydrological response of the headwaters to these droughts differed markedly from that of the lower areas of the basin.

Cardiometabolic Risk in PCOS: More than a Reproductive Disorder.

Science.gov (United States)

Torchen, Laura C

2017-11-11

Polycystic ovary syndrome (PCOS) is diagnosed by its characteristic reproductive features. However, PCOS is also associated with metabolic abnormalities, including insulin resistance and β-cell dysfunction. The severity of these abnormalities varies according to the reproductive phenotype, with the so-called NIH or classic phenotype conferring the greatest metabolic risk. The increased risk for type 2 diabetes (T2D) is well established among affected women with the NIH phenotype, but whether PCOS also confers an increased risk for cardiovascular events remains unknown. Recent studies in daughters of affected women have found evidence for pancreatic β-cell dysfunction prior to menarche. Further, genetic analyses have provided evidence that metabolic abnormalities such as obesity and insulin resistance contribute to the pathogenesis of PCOS. PCOS increases the risk for T2D. However, the risk for cardiovascular disease has not been quantified, and prospective, longitudinal studies are still critically needed.

Reproductive Toxicity of Triptolide in Male House Rat, Rattus rattus

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Neena Singla

2014-01-01

Full Text Available The aim of study was to investigate the toxic effect of triptolide fed in bait on reproduction of male house rat, Rattus rattus. Feeding of cereal based bait containing 0.2% triptolide to male R. rattus for 5 days in no-choice feeding test, leading to mean daily ingestion of 20.45 mg/kg bw of triptolide, was found effective in significantly (P≤0.05 reducing sperm motility and viability in cauda epididymal fluid by 80.65 and 75.14%, respectively, from that of untreated rats. Pregnancy rates were decreased by 100% in untreated cyclic female rats paired with male rats treated with 0.2% triptolide. Present studies suggest the potential of 0.2% triptolide bait in regulating reproductive output of R. rattus.

The predicted influence of climate change on lesser prairie-chicken reproductive parameters

Science.gov (United States)

Grisham, Blake A.; Boal, Clint W.; Haukos, David A.; Davis, D.; Boydston, Kathy K.; Dixon, Charles; Heck, Willard R.

2013-01-01

The Southern High Plains is anticipated to experience significant changes in temperature and precipitation due to climate change. These changes may influence the lesser prairie-chicken (Tympanuchus pallidicinctus) in positive or negative ways. We assessed the potential changes in clutch size, incubation start date, and nest survival for lesser prairie-chickens for the years 2050 and 2080 based on modeled predictions of climate change and reproductive data for lesser prairie-chickens from 2001-2011 on the Southern High Plains of Texas and New Mexico. We developed 9 a priori models to assess the relationship between reproductive parameters and biologically relevant weather conditions. We selected weather variable(s) with the most model support and then obtained future predicted values from climatewizard.org. We conducted 1,000 simulations using each reproductive parameter's linear equation obtained from regression calculations, and the future predicted value for each weather variable to predict future reproductive parameter values for lesser prairie-chickens. There was a high degree of model uncertainty for each reproductive value. Winter temperature had the greatest effect size for all three parameters, suggesting a negative relationship between above-average winter temperature and reproductive output. The above-average winter temperatures are correlated to La Nina events, which negatively affect lesser prairie-chickens through resulting drought conditions. By 2050 and 2080, nest survival was predicted to be below levels considered viable for population persistence; however, our assessment did not consider annual survival of adults, chick survival, or the positive benefit of habitat management and conservation, which may ultimately offset the potentially negative effect of drought on nest survival.

External and internal controls of lunar-related reproductive rhythms in fishes.

Science.gov (United States)

Takemura, A; Rahman, M S; Park, Y J

2010-01-01

Reproductive activities of many fish species are, to some extent, entrained to cues from the moon. During the spawning season, synchronous spawning is repeated at intervals of c. 1 month (lunar spawning cycle) and 2 weeks (semi-lunar spawning cycle) or daily according to tidal changes (tidal spawning cycle). In species showing lunar-related spawning cycles, oocytes in the ovary develop towards and mature around a specific moon phase for lunar spawners, around spring tides for semi-lunar spawners and at daytime high tides for tidal spawners. The production of sex steroid hormones also changes in accordance with synchronous oocyte development. Since the production of the steroid hormones with lunar-related reproductive periodicity is regulated by gonadotropins, it is considered that the higher parts of the hypothalamus-pituitary-gonad axis play important roles in the perception and regulation of lunar-related periodicity. It is likely that fishes perceive cues from the moon by sensory organs; however, it is still unknown how lunar cues are transduced as an endogenous rhythm exerting lunar-related spawning rhythmicity. Recent research has revealed that melatonin fluctuated according to the brightness at night, magnetic fields and the tidal cycle. In addition, cyclic changes in hydrostatic pressure had an effect on monoamine contents in the brain. These factors may be indirectly related to the exertion of lunar-related periodicity. Molecular approaches have revealed that mRNA expressions of light-sensitive clock genes change with moonlight, suggesting that brightness at night plays a role in phase-shifting or resetting of biological clocks. Some species may have evolved biological clocks in relation to lunar cycles, although it is still not known how lunar periodicities are endogenously regulated in fishes. This review demonstrates that lunar-related periodicity is utilized and incorporated by ecological and physiological mechanisms governing the reproductive success

Transcript Analysis and Regulative Events during Flower Development in Olive (Olea europaea L..

Directory of Open Access Journals (Sweden)

Fiammetta Alagna

Full Text Available The identification and characterization of transcripts involved in flower organ development, plant reproduction and metabolism represent key steps in plant phenotypic and physiological pathways, and may generate high-quality transcript variants useful for the development of functional markers. This study was aimed at obtaining an extensive characterization of the olive flower transcripts, by providing sound information on the candidate MADS-box genes related to the ABC model of flower development and on the putative genetic and molecular determinants of ovary abortion and pollen-pistil interaction. The overall sequence data, obtained by pyrosequencing of four cDNA libraries from flowers at different developmental stages of three olive varieties with distinct reproductive features (Leccino, Frantoio and Dolce Agogia, included approximately 465,000 ESTs, which gave rise to more than 14,600 contigs and approximately 92,000 singletons. As many as 56,700 unigenes were successfully annotated and provided gene ontology insights into the structural organization and putative molecular function of sequenced transcripts and deduced proteins in the context of their corresponding biological processes. Differentially expressed genes with potential regulatory roles in biosynthetic pathways and metabolic networks during flower development were identified. The gene expression studies allowed us to select the candidate genes that play well-known molecular functions in a number of biosynthetic pathways and specific biological processes that affect olive reproduction. A sound understanding of gene functions and regulatory networks that characterize the olive flower is provided.

Transcript Analysis and Regulative Events during Flower Development in Olive (Olea europaea L.).

Science.gov (United States)

Alagna, Fiammetta; Cirilli, Marco; Galla, Giulio; Carbone, Fabrizio; Daddiego, Loretta; Facella, Paolo; Lopez, Loredana; Colao, Chiara; Mariotti, Roberto; Cultrera, Nicolò; Rossi, Martina; Barcaccia, Gianni; Baldoni, Luciana; Muleo, Rosario; Perrotta, Gaetano

2016-01-01

The identification and characterization of transcripts involved in flower organ development, plant reproduction and metabolism represent key steps in plant phenotypic and physiological pathways, and may generate high-quality transcript variants useful for the development of functional markers. This study was aimed at obtaining an extensive characterization of the olive flower transcripts, by providing sound information on the candidate MADS-box genes related to the ABC model of flower development and on the putative genetic and molecular determinants of ovary abortion and pollen-pistil interaction. The overall sequence data, obtained by pyrosequencing of four cDNA libraries from flowers at different developmental stages of three olive varieties with distinct reproductive features (Leccino, Frantoio and Dolce Agogia), included approximately 465,000 ESTs, which gave rise to more than 14,600 contigs and approximately 92,000 singletons. As many as 56,700 unigenes were successfully annotated and provided gene ontology insights into the structural organization and putative molecular function of sequenced transcripts and deduced proteins in the context of their corresponding biological processes. Differentially expressed genes with potential regulatory roles in biosynthetic pathways and metabolic networks during flower development were identified. The gene expression studies allowed us to select the candidate genes that play well-known molecular functions in a number of biosynthetic pathways and specific biological processes that affect olive reproduction. A sound understanding of gene functions and regulatory networks that characterize the olive flower is provided.

The pineal gland, but not melatonin, is associated with the termination of seasonal testicular activity in an annual reproductive cycle in roseringed parakeet Psittacula krameri.

Science.gov (United States)

Sengupta, Anamika; Kumar Maitra, Saumen

2006-01-01

The role of the pineal gland and its hormone melatonin in the regulation of annual testicular events was investigated for the first time in a psittacine bird, the roseringed parakeet (Psittacula krameri). Accordingly, the testicular responsiveness of the birds was evaluated following surgical pinealectomy with or without the exogenous administration of melatonin and the experimental manipulations of the endogenous levels of melatonin through exposing the birds to continuous illumination. An identical schedule was followed during the four reproductive phases, each characterizing a distinct testicular status in the annual cycle, namely, the phases of gametogenic quiescence (preparatory phase), seasonal recovery of gametogenesis (progressive phase), seasonal initiation of sperm formation (pre-breeding phase), and peak gametogenic activity (breeding phase). In each reproductive phase, the birds were subjected to various experimental conditions, and the effects were studied comparing the testicular conditions in the respective control birds. The study included germ cell profiles of the seminiferous tubules, the activities of steroidogenic enzymes 17beta-hydroxysteroid dehydrogenase (17beta-HSD), and Delta(5)3beta-hydroxysteroid dehydrogenase (Delta(5)3beta- HSD) in the testis, and the serum levels of testosterone and melatonin. An analysis of the data reveals that the pineal gland and its hormone melatonin may play an inhibitory role in the development of the testis until the attainment of the seasonal peak in the annual reproductive cycle. However, in all probability, the termination of the seasonal activity of the testis or the initiation of testicular regression in the annual reproductive cycle appears to be the function of the pineal gland, but not of melatonin.

Normal Female Reproductive Anatomy

Science.gov (United States)

... historical Searches are case-insensitive Reproductive System, Female, Anatomy Add to My Pictures View /Download : Small: 720x756 ... Large: 3000x3150 View Download Title: Reproductive System, Female, Anatomy Description: Anatomy of the female reproductive system; drawing ...

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.

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

Male reproductive system and spermatophores production and storage in Histioteuthis bonnellii (Cephalopoda: Histioteuthidae): A look into deep-sea squids' reproductive strategy

Science.gov (United States)

Cuccu, Danila; Mereu, Marco; Agus, Blondine; Cau, Angelo; Culurgioni, Jacopo; Sabatini, Andrea; Jereb, Patrizia

2014-09-01

size indicate that in H. bonnellii males the allocation and storage of sperm start early in the individual life and extends in time, while animals continue to grow and produce spermatophores presumably more successful in attaching to female tissues. This pattern enlarges the time window available for reproduction and likely maximizes the percentage of mating success as the animals grow older and chances of mating events become comparatively lower, due to the basic low density of specimens in the deep-sea environment. Both aspects are potentially indicative of adaptation to the deep sea.

Stress and anxiety-depression levels following first-trimester miscarriage: a comparison between women who conceived naturally and women who conceived with assisted reproduction.

Science.gov (United States)

Cheung, C S; Chan, C H; Ng, E H

2013-08-01

To compare the psychological impact following early miscarriage between women who conceived naturally and women who conceived following assisted reproduction. Prospective cohort study. Assisted reproduction clinic and general gynaecological unit in a university-affiliated, tertiary referral hospital. A cohort of 150 women (75 after natural conception; 75 after assisted reproduction). Completed semi-structured interviews using two standard questionnaires [the 12-item General Health Questionnaire (GHQ-12) and the 22-item Revised Impact of Events Scale (IES-R)], at 1, 4, and 12 weeks after a diagnosis of first-trimester miscarriage. The GHQ-12 and IES-R scores for the two groups of women. The GHQ-12 and IES-R scores were significantly higher in the assisted reproduction group than the scores in the natural conception group, at 4 weeks and 12 weeks after miscarriage. Further breakdown of the scores revealed significantly higher hyperarousal symptoms at 4 and 12 weeks in the assisted reproduction group, indicating the traumatic effect of miscarriage to these women. Following first-trimester miscarriage, subfertile women who conceived after assisted reproduction had higher stress and anxiety-depression levels, and experienced more traumatic impact from the event, than those after natural conception. A timely support and psychological intervention would be beneficial in the management of this group of women. © 2013 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2013 RCOG.

Reproduction, physiology and biochemistry

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This chapter summarizes fundamental knowledge and recent discoveries about the reproduction, physiology and biochemistry of plant-parasitic nematodes. Various types of reproduction are reviewed, including sexual reproduction and mitotic and meiotic parthenogenesis. Although much is known about the p...

Effect of raceme-localized supplemental light on soybean reproductive abscission

International Nuclear Information System (INIS)

Myers, R.L.; Brun, W.A.; Brenner, M.L.

1987-01-01

The percentage of soybean [Glycine max (L.) Merr.] reproductive structures that abscise is a potentially important yield factor. To better understand the involvement of light in the abscission of reproductive structures, a series of in vitro raceme-culture and growth-chamber experiments were conducted. In the in vitro raceme-culture experiments, racemes with four to six flowers at or past anthesis were excised from the soybean plant (genotype IX93-100), embedded in a complete nutrient, solid agar medium, and subjected to various light treatments. A series of three experiments indicated that the racemes contain a photoreceptor, possibly phytochrome, capable of regulating sucrose accumulation. In each of the growth chamber studies, supplemental light was supplied directly to individual soybean flowers via fiber optic light guides. The light source increased the photon flux to the flowers by 10-fold. The first growth chamber experiment showed that flowers receiving supplemental light were more intense sinks for 14 C-sucrose than were controls (intensity value of 1.0 vs 0.4 x 10 -7 , intensity = [dps of flower/dps of raceme]/[kg dry wt of flower]). In a second study, 42% of flowers treated with supplemental light set pods, while only 26% of control flowers set pods. A third experiment showed that red supplemental light produced 55% fruit set, compared to 41% set for far-red light, and 35% for controls. These experiments indicate that both photoassimilate accumulation and abscission in young soybean reproductive structures may be regulated by light quality

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...

Symbiotic regulation of plant growth, development and reproduction

Science.gov (United States)

Russell J. Rodriguez; D. Carl Freeman; E. Durant McArthur; Yong Ok Kim; Regina S. Redman

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...

Similar causes of various reproductive disorders in early life

Directory of Open Access Journals (Sweden)

Konstantin Svechnikov

2014-02-01

Full Text Available During the past few decades, scientific evidence has been accumulated concerning the possible adverse effects of the exposure to environmental chemicals on the well-being of wildlife and human populations. One large and growing group of such compounds of anthropogenic or natural origin is referred to as endocrine-disrupting chemicals (EDCs, due to their deleterious action on the endocrine system. This concern was first focused on the control of reproductive function particularly in males, but has later been expanded to include all possible endocrine functions. The present review describes the underlying physiology behind the cascade of developmental events that occur during sexual differentiation of males and the specific role of androgen in the masculinization process and proper organogenesis of the external male genitalia. The impact of the genetic background, environmental exposures and lifestyle factors in the etiology of hypospadias, cryptorchidism and testicular cancer are reviewed and the possible role of EDCs in the development of these reproductive disorders is discussed critically. Finally, the possible direct and programming effects of exposures in utero to widely use therapeutic compounds, environmental estrogens and other chemicals on the incidence of reproductive abnormalities and poor semen quality in humans are also highlighted.

Regulating cinematic stories about reproduction: pregnancy, childbirth, abortion and movie censorship in the US, 1930-1958.

Science.gov (United States)

Kirby, David A

2017-09-01

In the mid-twentieth century film studios sent their screenplays to Hollywood's official censorship body, the Production Code Administration (PCA), and to the Catholic Church's Legion of Decency for approval and recommendations for revision. This article examines the negotiations between filmmakers and censorship groups in order to show the stories that censors did, and did not, want told about pregnancy, childbirth and abortion, as well as how studios fought to tell their own stories about human reproduction. I find that censors considered pregnancy to be a state of grace and a holy obligation that was restricted to married women. For censors, human reproduction was not only a private matter, it was also an unpleasant biological process whose entertainment value was questionable. They worried that realistic portrayals of pregnancy and childbirth would scare young women away from pursuing motherhood. In addition, I demonstrate how filmmakers overcame censors' strict prohibitions against abortion by utilizing ambiguity in their storytelling. Ultimately, I argue that censors believed that pregnancy and childbirth should be celebrated but not seen. But if pregnancy and childbirth were required then censors preferred mythic versions of motherhood instead of what they believed to be the sacred but horrific biological reality of human reproduction.

Role of oxidative stress in female reproduction

Directory of Open Access Journals (Sweden)

Sharma Rakesh K

2005-07-01

embryopathies, preterm labour and preeclampsia and gestational diabetes. The review also addresses the growing literature on the role of nitric oxide species in female reproduction. The involvement of nitric oxide species in regulation of endometrial and ovarian function, etiopathogenesis of endometriosis, and maintenance of uterine quiescence, initiation of labour and ripening of cervix at parturition is discussed. Complex interplay between cytokines and oxidative stress in the etiology of female reproductive disorders is discussed. Oxidant status of the cell modulates angiogenesis, which is critical for follicular growth, corpus luteum formation endometrial differentiation and embryonic growth is also highlighted in the review. Strategies to overcome oxidative stress and enhance fertility, both natural and assisted are delineated. Early interventions being investigated for prevention of preeclampsia are enumerated. Trials investigating combination intervention strategy of vitamin E and vitamin C supplementation in preventing preeclampsia are highlighted. Antioxidants are powerful and there are few trials investigating antioxidant supplementation in female reproduction. However, before clinicians recommend antioxidants, randomized controlled trials with sufficient power are necessary to prove the efficacy of antioxidant supplementation in disorders of female reproduction. Serial measurement of oxidative stress biomarkers in longitudinal studies may help delineate the etiology of some of the diosorders in female reproduction such as preeclampsia.

Extraterritoriality for cross-border reproductive care: should states act against citizens travelling abroad for illegal infertility treatment?

Science.gov (United States)

Van Hoof, Wannes; Pennings, Guido

2011-11-01

Since the development of assisted reproduction technologies, there has been discussion on which people should have access to these technologies and which treatments and techniques are morally acceptable. However, national legislation can no longer determine what citizens do. Some countries react to their citizens going abroad to evade restrictions by implementing even more restrictive laws. Turkey has recently become the first state to ban reproductive travel in pursuit of donor gametes. Several states in Australia have enacted or are considering laws that prohibit international commercial surrogacy. This article investigates the consistency and morality of several state reactions to cross-border reproductive care (CBRC), including extraterritorial regulation. The only widespread existing extraterritorial regulation of private life concerns female genital cutting (FGC), sex with children and (largely in the past) abortion. This discussion develops an analogy with these cross-border crimes to evaluate the morality of similar legislation in cases of CBRC. The dissimilarity in these analogies shows that extraterritoriality is a radical position that is generally inappropriate in the case of CBRC. Subsequently, several potential state reactions to CBRC for law evasion are considered. It is concluded that legislation of CBRC should be modest, tolerant and nuanced. Copyright © 2011 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Regulation of Schistosoma mansoni development and reproduction by the mitogen-activated protein kinase signaling pathway.

Science.gov (United States)

Andrade, Luiza Freire de; Mourão, Marina de Moraes; Geraldo, Juliana Assis; Coelho, Fernanda Sales; Silva, Larissa Lopes; Neves, Renata Heisler; Volpini, Angela; Machado-Silva, José Roberto; Araujo, Neusa; Nacif-Pimenta, Rafael; Caffrey, Conor R; Oliveira, Guilherme

2014-06-01

Protein kinases are proven targets for drug development with an increasing number of eukaryotic Protein Kinase (ePK) inhibitors now approved as drugs. Mitogen-activated protein kinase (MAPK) family members connect cell-surface receptors to regulatory targets within cells and influence a number of tissue-specific biological activities such as cell proliferation, differentiation and survival. However, the contributions of members of the MAPK pathway to schistosome development and survival are unclear. We employed RNA interference (RNAi) to elucidate the functional roles of five S. mansoni genes (SmCaMK2, SmJNK, SmERK1, SmERK2 and SmRas) involved in MAPK signaling pathway. Mice were injected with post-infective larvae (schistosomula) subsequent to RNAi and the development of adult worms observed. The data demonstrate that SmJNK participates in parasite maturation and survival of the parasites, whereas SmERK are involved in egg production as infected mice had significantly lower egg burdens with female worms presenting underdeveloped ovaries. Furthermore, it was shown that the c-fos transcription factor was overexpressed in parasites submitted to RNAi of SmERK1, SmJNK and SmCaMK2 indicating its putative involvement in gene regulation in this parasite's MAPK signaling cascade. We conclude that MAPKs proteins play important roles in the parasite in vivo survival, being essential for normal development and successful survival and reproduction of the schistosome parasite. Moreover SmERK and SmJNK are potential targets for drug development.

Kisspeptin and the seasonal control of reproduction in hamsters

DEFF Research Database (Denmark)

Simonneaux, Valérie; Ansel, Laura; Revel, Florent G

2008-01-01

-expressing neurons, which were recently shown to be implicated in the regulation of GnRH release. Hamsters are seasonal rodents which are sexually active in long photoperiod and quiescent in short photoperiod. The photoperiodic information is transmitted to the reproductive system by melatonin, a pineal...... hormone whose secretion is adjusted to night length. The photoperiodic variation in circulating melatonin has been shown to synchronize reproductive activity with seasons, but the mechanisms involved in this effect of melatonin were so far unknown. Recently we have observed that Kiss1 mRNA level...... in the arcuate nucleus of the Syrian hamster is lower in short photoperiod, when animals are sexually quiescent. Notably, intracerebroventricular infusion of Kiss1 gene product, kisspeptin, in hamsters kept in short photoperiod is able to override the inhibitory photoperiod and to reactivate sexual activity...

At the crossroads of physiology and ecology: food supply and the timing of avian reproduction.

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Davies, Scott; Deviche, Pierre

2014-06-01

This article is part of a Special Issue “Energy Balance”. The decision of when to breed is crucial to the reproductive success and fitness of seasonally breeding birds. The availability of food for adults prior to breeding has long been thought to play a critical role in timing the initiation of seasonal reproductive events, in particular laying. However, unequivocal evidence for such a role remains limited and the physiological mechanisms by which an increase in food availability results in seasonal activation of the reproductive system are largely speculative. This lack of mechanistic information partly reflects a lack of integration of ecological and physiological approaches to study seasonal reproduction. Indeed, most work pertaining to the role of food availability for adults on the timing of avian reproduction has been ecological and has focused almost exclusively on female traits associated with reproductive timing (e.g., lay date and clutch size). By contrast, most work on the physiological bases of the relationship between food availability and the timing of reproduction has investigated male traits associated with reproductive development (e.g., reproductive hormones and gonadal development). To advance our understanding of these topics, we review the role of proximate factors including food availability, social factors, and ambient temperature in the control of breeding decisions, and discuss the role of three potential candidates (leptin, glucocorticoids, and GnIH-neuropeptide Y) that may mediate the effects of food availability on these decisions. We emphasize that future progress in this area is heavily contingent upon the use of physiology-based approaches and their integration into current ecological frameworks. Published by Elsevier Inc.

End-Binding Protein 1 (EB1) Up-regulation is an Early Event in Colorectal Carcinogenesis

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Stypula-Cyrus, Yolanda; Mutyal, Nikhil N.; Cruz, Mart Angelo Dela; Kunte, Dhananjay P.; Radosevich, Andrew J.; Wali, Ramesh; Roy, Hemant K.; Backman, Vadim

2014-01-01

End-binding protein (EB1) is a microtubule protein that binds to the tumor suppressor adenomatous polyposis coli (APC). While EB1 is implicated as a potential oncogene, its role in cancer progression is unknown. Therefore, we analyzed EB1/APC expression at the earliest stages of colorectal carcinogenesis and in the uninvolved mucosa ("field effect") of human and animal tissue. We also performed siRNA-knockdown in colon cancer cell lines. EB1 is up-regulated in early and field carcinogenesis in the colon, and the cellular/nano-architectural effect of EB1 knockdown depended on the genetic context. Thus, dysregulation of EB1 is an important early event in colon carcinogenesis. PMID:24492008

Snow cover and extreme winter warming events control flower abundance of some, but not all species in high arctic Svalbard

DEFF Research Database (Denmark)

Semenchuk, Philipp R.; Elberling, Bo; Cooper, Elisabeth J.

2013-01-01

octopetala. However, the affected species were resilient and individuals did not experience any long term effects. In the case of short or cold summers, a subset of species suffered reduced reproductive success, which may affect future plant composition through possible cascading competition effects. Extreme...... winter warming events were shown to expose the canopy to cold winter air. The following summer most of the overwintering flower buds could not produce flowers. Thus reproductive success is reduced if this occurs in subsequent years. We conclude that snow depth influences flower abundance by altering...... events, while Stellaria crassipes responded partly. Snow pack thickness determined whether winter warming events had an effect on flower abundance of some species. Warming events clearly reduced flower abundance in shallow but not in deep snow regimes of Cassiope tetragona, but only marginally for Dryas...

Predicting primate responses to "Stochastic" demographic events.

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Strier, K B

1999-01-01

Comparative approaches in contemporary primate behavioral ecology have tended to emphasize the deterministic properties of stochastic ecological variables. Yet, primate responses to ecological fluctuations may be mediated by the interactions among demographic processes at the levels of individuals, groups, and populations. In this paper I examine long-term data collected from June 1982-July 1998 on one expanding group of muriquis (Brachyteles arachnoides) at the Estação Biologica de Caratinga, Minas Gerais, Brazil to explore the demographic and life history correlates of reproductive seasonality and skewed infant sex ratios. Variation in the size of annual birth cohorts (≥2 infants) was positively related to variation in the annual distribution of births (r (s)=0.96,n=10,p<0.01), indicating the importance of considering the effects that the number of reproductive females may have on interpretations of reproductive seasonality. The female-biased infants sex ratio documented from 59 births was attributed exclusively to multiparous mothers. Primiparous mothers produced comparable numbers of sons (n=6) and daughters (n=7), and were increasingly likely to produce daughters with each subsequent reproductive event. Seven of the 11 females that have produced≥3 infants to date exhibited biases in favor of daughters whereas only 1 was biased in favor of sons. Variation in female sensitivity to local resource competition at different stages of their life histories may account for the female-biased infant sex ration in this population.

MECHANISMS IN ENDOCRINOLOGY: Nutrition as a mediator of oxidative stress in metabolic and reproductive disorders in women.

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Diamanti-Kandarakis, Evanthia; Papalou, Olga; Kandaraki, Eleni A; Kassi, Georgia

2017-02-01

Nutrition can generate oxidative stress and trigger a cascade of molecular events that can disrupt oxidative and hormonal balance. Nutrient ingestion promotes a major inflammatory and oxidative response at the cellular level in the postprandial state, altering the metabolic state of tissues. A domino of unfavorable metabolic changes is orchestrated in the main metabolic organs, including adipose tissue, skeletal muscle, liver and pancreas, where subclinical inflammation, endothelial dysfunction, mitochondrial deregulation and impaired insulin response and secretion take place. Simultaneously, in reproductive tissues, nutrition-induced oxidative stress can potentially violate delicate oxidative balance that is mandatory to secure normal reproductive function. Taken all the above into account, nutrition and its accompanying postprandial oxidative stress, in the unique context of female hormonal background, can potentially compromise normal metabolic and reproductive functions in women and may act as an active mediator of various metabolic and reproductive disorders. © 2017 European Society of Endocrinology.

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.

Multimodal interaction in the perception of impact events displayed via a multichannel audio and simulated structure-borne vibration

Science.gov (United States)

Martens, William L.; Woszczyk, Wieslaw

2005-09-01

For multimodal display systems in which realistic reproduction of impact events is desired, presenting structure-borne vibration along with multichannel audio recordings has been observed to create a greater sense of immersion in a virtual acoustic environment. Furthermore, there is an increased proportion of reports that the impact event took place within the observer's local area (this is termed ``presence with'' the event, in contrast to ``presence in'' the environment in which the event occurred). While holding the audio reproduction constant, varying the intermodal arrival time and level of mechanically displayed, synthetic whole-body vibration revealed a number of other subjective attributes that depend upon multimodal interaction in the perception of a representative impact event. For example, when the structure-borne component of the displayed impact event arrived 10 to 20 ms later than the airborne component, the intermodal delay was not only tolerated, but gave rise to an increase in the proportion of reports that the impact event had greater power. These results have enabled the refinement of a multimodal simulation in which the manipulation of synthetic whole-body vibration can be used to control perceptual attributes of impact events heard within an acoustic environment reproduced via a multichannel loudspeaker array.

Cardiometabolic Risk in PCOS: More than a Reproductive Disorder

Science.gov (United States)

Torchen, Laura C.

2018-01-01

Purpose of Review Polycystic ovary syndrome (PCOS) is diagnosed by its characteristic reproductive features. However, PCOS is also associated with metabolic abnormalities, including insulin resistance and β-cell dysfunction. The severity of these abnormalities varies according to the reproductive phenotype, with the so-called NIH or classic phenotype conferring the greatest metabolic risk. The increased risk for type 2 diabetes (T2D) is well-established among affected women with the NIH phenotype, but whether PCOS also confers an increased risk for cardiovascular events remains unknown. Recent Findings Recent studies in daughters of affected women have found evidence for pancreatic β-cell dysfunction prior to menarche. Further, genetic analyses have provided evidence that metabolic abnormalities such as obesity and insulin resistance contribute to the pathogenesis of PCOS. Summary PCOS increases the risk for T2D. However, the risk for cardiovascular disease has not been quantified, and prospective, longitudinal studies are still critically needed. PMID:29128916

Moonlighting? - Consequences of lunar cues on anuran reproductive activity

Science.gov (United States)

Underhill, Victoria A.; Höbel, Gerlinde

2018-02-01

While the influence of environmental variables, particularly temperature and rainfall, on the breeding behavior of amphibians is widely recognized, relatively few studies have addressed how the moon affects amphibian behavior. Yet, the lunar cycle provides several rhythmic temporal cues that animals could use to time important group events such as spawning, and the substantial changes in light levels associated with the different moon phases may also affect the behavior of nocturnal frogs. Using seven years of field observation data, we tested for lunar effects on the reproductive activity of male and female Eastern Gray Treefrogs (Hyla versicolor). We found that chorusing and breeding activity was statistically more likely to occur around the first quarter of the moon and during intermediately bright nights, but that reproductive activity also occurred during various other times during the lunar cycle. We discuss these findings in relation to the two main hypotheses of lunar effects on animals: predator avoidance and temporal synchronization of breeding.

Molecular basis for the reproductive division of labour in a lower termite

Directory of Open Access Journals (Sweden)

Rehli Michael

2007-06-01

Full Text Available Abstract Background Polyphenism, the expression of different phenotypes with the same genetic background, is well known for social insects. The substantial physiological and morphological differences among the castes generally are the result of differential gene expression. In lower termites, workers are developmentally flexible to become neotenic replacement reproductives via a single moult after the death of the founding reproductives. Thus, both castes (neotenics and workers are expected to differ mainly in the expression of genes linked to reproductive division of labour, which constitutes the fundamental basis of insect societies. Results Representational difference analysis of cDNAs was used to study differential gene expression between neotenics and workers in the drywood termite Cryptotermes secundus (Kalotermitidae. We identified and, at least partially cloned five novel genes that were highly expressed in female neotenics. Quantitative real-time PCR analysis of all five genes in different castes (neotenics, founding reproductives, winged sexuals and workers of both sexes confirmed the differential expression patterns. In addition, the relative expression of these genes was determined in three body parts of female neotenics (head, thorax, and abdomen using quantitative real-time PCR. Conclusion The identified genes could be involved in the control and regulation of reproductive division of labour. Interestingly, this study revealed an expression pattern partly similar to social Hymenoptera indicating both common and species-specific regulatory mechanisms in hemimetabolous and holometabolous social insects.

Rising cyclin-CDK levels order cell cycle events.

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Catherine Oikonomou

Full Text Available Diverse mitotic events can be triggered in the correct order and time by a single cyclin-CDK. A single regulator could confer order and timing on multiple events if later events require higher cyclin-CDK than earlier events, so that gradually rising cyclin-CDK levels can sequentially trigger responsive events: the "quantitative model" of ordering.This 'quantitative model' makes predictions for the effect of locking cyclin at fixed levels for a protracted period: at low cyclin levels, early events should occur rapidly, while late events should be slow, defective, or highly variable (depending on threshold mechanism. We titrated the budding yeast mitotic cyclin Clb2 within its endogenous expression range to a stable, fixed level and measured time to occurrence of three mitotic events: growth depolarization, spindle formation, and spindle elongation, as a function of fixed Clb2 level. These events require increasingly more Clb2 according to their normal order of occurrence. Events occur efficiently and with low variability at fixed Clb2 levels similar to those observed when the events normally occur. A second prediction of the model is that increasing the rate of cyclin accumulation should globally advance timing of all events. Moderate (<2-fold overexpression of Clb2 accelerates all events of mitosis, resulting in consistently rapid sequential cell cycles. However, this moderate overexpression also causes a significant frequency of premature mitoses leading to inviability, suggesting that Clb2 expression level is optimized to balance the fitness costs of variability and catastrophe.We conclude that mitotic events are regulated by discrete cyclin-CDK thresholds. These thresholds are sequentially triggered as cyclin increases, yielding reliable order and timing. In many biological processes a graded input must be translated into discrete outputs. In such systems, expression of the central regulator is likely to be tuned to an optimum level, as we

Enduring politics: the culture of obstacles in legislating for assisted reproduction technologies in Ireland

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Jill Allison

2016-12-01

Full Text Available Assisted reproductive technology has become a normalized part of reproductive medicine in many countries around the world. Access, however, is uneven and inconsistent, facilitated and restricted by such factors as affordability, social and moral acceptance or refusal and local cultures of medical practice. In Ireland, assisted reproductive technology has been available since 1987 but remains unregulated by legislation. This creates an uncertain and untenable legal circumstance given the contested issues related to constitutional protection of the right to life of the unborn and the indeterminate legal status of embryos in vitro. This paper examines the impact of an enduring political impasse. It explores how clinical assisted reproductive technology services in Ireland operate both inside and outside dominant institutional frameworks, meeting a pronatalist and pro-family social and political agenda, while sometimes contradicting the pro-life politics that has continued to shape women’s reproductive lives. The medical approaches to infertility thus intersect with the ongoing debates around abortion, the failure of the government to regulate, and notions of embodied motherhood and responsibility within changing meanings of family and kinship. At the same time women and their partners seek assisted reproductive technology treatment in other countries throughout the European Union where laws differ and availability of services varies. A decade has passed since the Commission on Assisted Human Reproduction in Ireland released its recommendations; the enduring legislative vacuum leaves women, families and practitioners in potential legal limbo.

Estradiol Membrane-Initiated Signaling in the Brain Mediates Reproduction.

Science.gov (United States)

Micevych, Paul E; Mermelstein, Paul G; Sinchak, Kevin

2017-11-01

Over the past few years our understanding of estrogen signaling in the brain has expanded rapidly. Estrogens are synthesized in the periphery and in the brain, acting on multiple receptors to regulate gene transcription, neural function, and behavior. Various estrogen-sensitive signaling pathways often operate in concert within the same cell, increasing the complexity of the system. In females, estrogen concentrations fluctuate over the estrous/menstrual cycle, dynamically modulating estrogen receptor (ER) expression, activity, and trafficking. These dynamic changes influence multiple behaviors but are particularly important for reproduction. Using the female rodent model, we review our current understanding of estradiol signaling in the regulation of sexual receptivity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Safeguards Summary Event List (SSEL)

International Nuclear Information System (INIS)

1991-07-01

The Safeguards Summary Event List (SSEL) provides brief summaries of several hundred safeguards-related events involving nuclear material or facilities regulated by the US Nuclear Regulatory Commission (NRC). Because of public interest, the Miscellaneous category includes a few events which involve either source material, byproduct material, or natural uranium which are exempt from safeguards requirements. Events are described under the categories of bomb-related, intrusion, missing and/or allegedly stolen, transportation, tampering/vandalism, arson, firearms, radiological sabotage, nonradiological sabotage, pre-1990 alcohol and drugs (involving reactor operators, security force members, or management persons), and miscellaneous. The information contained in the event descriptions is derived primarily from official NRC reporting channels

Third-party reproduction in the Internet Age: the new, patient-centered landscape.

Science.gov (United States)

Woodward, Julia T

2015-09-01

The rise of the Internet Age has brought a host of sweeping changes to the landscape of third-party reproduction. What began as a dyadic relationship between doctor and patient has evolved into a more complex system in which patients are able to access information online from a variety of external sources. Patients often seek to play a more active role in their third-party reproductive care, and the Internet allows them to do so. Further, demand for both medical and psychosocial information about donors and donor-conceived siblings, available online through patient forums and genetic registries, has altered the perception of gamete donation from a one-time event to an ongoing relationship. The advantages and disadvantages for patients and providers of this freer flow of information between third-party participants are examined. Search motivations of recipients and offspring, as well as types of information sought, are detailed. Recommendations are made regarding strategies fertility programs can use to optimally support their patients and navigate this new landscape. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Defining global neuroendocrine gene expression patterns associated with reproductive seasonality in fish.

Directory of Open Access Journals (Sweden)

Dapeng Zhang

Full Text Available BACKGROUND: Many vertebrates, including the goldfish, exhibit seasonal reproductive rhythms, which are a result of interactions between external environmental stimuli and internal endocrine systems in the hypothalamo-pituitary-gonadal axis. While it is long believed that differential expression of neuroendocrine genes contributes to establishing seasonal reproductive rhythms, no systems-level investigation has yet been conducted. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, by analyzing multiple female goldfish brain microarray datasets, we have characterized global gene expression patterns for a seasonal cycle. A core set of genes (873 genes in the hypothalamus were identified to be differentially expressed between May, August and December, which correspond to physiologically distinct stages that are sexually mature (prespawning, sexual regression, and early gonadal redevelopment, respectively. Expression changes of these genes are also shared by another brain region, the telencephalon, as revealed by multivariate analysis. More importantly, by examining one dataset obtained from fish in October who were kept under long-daylength photoperiod (16 h typical of the springtime breeding season (May, we observed that the expression of identified genes appears regulated by photoperiod, a major factor controlling vertebrate reproductive cyclicity. Gene ontology analysis revealed that hormone genes and genes functionally involved in G-protein coupled receptor signaling pathway and transmission of nerve impulses are significantly enriched in an expression pattern, whose transition is located between prespawning and sexually regressed stages. The existence of seasonal expression patterns was verified for several genes including isotocin, ependymin II, GABA(A gamma2 receptor, calmodulin, and aromatase b by independent samplings of goldfish brains from six seasonal time points and real-time PCR assays. CONCLUSIONS/SIGNIFICANCE: Using both

Insights into the Molecular Events That Regulate Heat-Induced Chilling Tolerance in Citrus Fruits.

Science.gov (United States)

Lafuente, María T; Establés-Ortíz, Beatriz; González-Candelas, Luis

2017-01-01

Low non-freezing temperature may cause chilling injury (CI), which is responsible for external quality deterioration in many chilling-sensitive horticultural crops. Exposure of chilling-sensitive citrus cultivars to non-lethal high-temperature conditioning may increase their chilling tolerance. Very little information is available about the molecular events involved in such tolerance. In this work, the molecular events associated with the low temperature tolerance induced by heating Fortune mandarin, which is very sensitive to chilling, for 3 days at 37°C prior to cold storage is presented. A transcriptomic analysis reveals that heat-conditioning has an important impact favoring the repression of genes in cold-stored fruit, and that long-term heat-induced chilling tolerance is an active process that requires activation of transcription factors involved in transcription initiation and of the WRKY family. The analysis also shows that chilling favors degradation processes, which affect lipids and proteins, and that the protective effect of the heat-conditioning treatment is more likely to be related to the repression of the genes involved in lipid degradation than to the modification of fatty acids unsaturation, which affects membrane permeability. Another major factor associated with the beneficial effect of the heat treatment on reducing CI is the regulation of stress-related proteins. Many of the genes that encoded such proteins are involved in secondary metabolism and in oxidative stress-related processes.

Insights into the Molecular Events That Regulate Heat-Induced Chilling Tolerance in Citrus Fruits

Directory of Open Access Journals (Sweden)

María T. Lafuente

2017-06-01

Full Text Available Low non-freezing temperature may cause chilling injury (CI, which is responsible for external quality deterioration in many chilling-sensitive horticultural crops. Exposure of chilling-sensitive citrus cultivars to non-lethal high-temperature conditioning may increase their chilling tolerance. Very little information is available about the molecular events involved in such tolerance. In this work, the molecular events associated with the low temperature tolerance induced by heating Fortune mandarin, which is very sensitive to chilling, for 3 days at 37°C prior to cold storage is presented. A transcriptomic analysis reveals that heat-conditioning has an important impact favoring the repression of genes in cold-stored fruit, and that long-term heat-induced chilling tolerance is an active process that requires activation of transcription factors involved in transcription initiation and of the WRKY family. The analysis also shows that chilling favors degradation processes, which affect lipids and proteins, and that the protective effect of the heat-conditioning treatment is more likely to be related to the repression of the genes involved in lipid degradation than to the modification of fatty acids unsaturation, which affects membrane permeability. Another major factor associated with the beneficial effect of the heat treatment on reducing CI is the regulation of stress-related proteins. Many of the genes that encoded such proteins are involved in secondary metabolism and in oxidative stress-related processes.

What shapes fitness costs of reproduction in long-lived iteroparous species? A case study on the Alpine ibex.

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Garnier, Alexandre; Gaillard, Jean-Michel; Gauthier, Dominique; Besnard, Aurélien

2016-01-01

The fitness costs of reproduction can be masked by individual differences, and may only become apparent during adverse environmental conditions. Individual differences, however, are usually assessed by reproductive success, so how fitness costs are influenced by the interplay between the environmental context and overall individual differences requires further investigation. Here, we evaluated fitness costs of reproduction based on 15 yr of monitoring of individual Alpine ibex (Capra ibex) during a period when the population was affected by a severe disease outbreak (pneumonia). We quantified fitness costs using a novel multi-event capture-mark-recapture (CMR) modeling approach that accounted for uncertainty in reproductive status to estimate the survival and reproductive success of female ibex while also accounting for overall individual heterogeneity using mixture models. Our results show that the ability of females to reproduce was highly heterogeneous. In particular, one group including 76% of females had a much higher probability of giving birth annually (between 0.66 and 0.77, depending on the previous reproductive status) than females of the second group (24% of females, between 0 and 0.05 probability of giving birth annually). Low reproductive costs in terms of future reproduction occurred and were independent of the pneumonia outbreak. There was no survival cost of reproduction either before or after the epizootic, but the cost was high during the epizootic. Our findings indicate that adverse environmental conditions, such as disease outbreaks, may lead to survival costs of reproduction in long-lived species and select against females that have a high reproductive effort. Thereby, the occurrence of adverse conditions increases the diversity of reproductive tactics within a population.

Stress and the hypothalamus-pituitary-gonadal axis in the cyclic rat

NARCIS (Netherlands)

Roozendaal, M.M.

1997-01-01

The influence of stress on reproductive functions has been subject of much research. Various kinds of stress are known to affect reproductive functions. In females, the complex regulation of the ovarian cycle relies on a series of neuroendocrine events whose temporal relationship is so

Review of events at large pool-type irradiators

International Nuclear Information System (INIS)

Trager, E.A. Jr.

1989-03-01

Large pool-type gamma irradiators are used in applications such as the ''cold'' sterilization of medical and pharmaceutical supplies, and recent changes in federal regulations make it possible they will be used extensively in the preservation of foodstuffs. Because of this possible large increase in the use of irradiators, the Office of Nuclear Materials Safety and Safeguards was interested in knowing what events had occurred at irradiators. The event data would be used as background in developing new regulations on irradiators. Therefore, AEOD began a study of the operating experience at large, wet source storage gamma irradiators. The scope of the study was to assess all available operating information on large (≥ 250,000 curie), pool-type irradiators licensed by both the NRC and the Agreement States, and events at foreign facilities. The study found that about 0.12 events have been reported per irradiator-year. Most of these events were precursor events, in that there was no evidence of damage to the radioactive sources or degradation in the level of safety of the facility. Events with more significant impacts had a reported frequency of about 0.01 event per irradiator-year. However, the actual rate of occurrence of events of concern to the staff may be higher because there are few specific reporting requirements for events at irradiators. It is suggested that during development of a regulation for large pool-type irradiators consideration be given to specifying requirements for: reporting breakdowns in access control systems; periodic inspection of the source movement and suspension system; systems to detect source leakage and product contamination; allowable pool leakage; and feedback of information on operational events involving safety-important systems

Female Reproductive System

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... of the Female Reproductive System Print en español Sistema reproductor femenino About Human Reproduction All living things ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on KidsHealth® is for ...

Adult Neurogenesis in Sheep: Characterization and Contribution to Reproduction and Behavior

Science.gov (United States)

Lévy, Frederic; Batailler, Martine; Meurisse, Maryse; Migaud, Martine

2017-01-01

Sheep have many advantages to study neurogenesis in comparison to the well-known rodent models. Their development and life expectancy are relatively long and they possess a gyrencephalic brain. Sheep are also seasonal breeders, a characteristic that allows studying the involvement of hypothalamic neurogenesis in the control of seasonal reproduction. Sheep are also able to individually recognize their conspecifics and develop selective and lasting bonds. Adult olfactory neurogenesis could be adapted to social behavior by supporting recognition of conspecifics. The present review reveals the distinctive features of the hippocampal, olfactory, and hypothalamic neurogenesis in sheep. In particular, the organization of the subventricular zone and the dynamic of neuronal maturation differs from that of rodents. In addition, we show that various physiological conditions, such as seasonal reproduction, gestation, and lactation differently modulate these three neurogenic niches. Last, we discuss recent evidence indicating that hypothalamic neurogenesis acts as an important regulator of the seasonal control of reproduction and that olfactory neurogenesis could be involved in odor processing in the context of maternal behavior. PMID:29109674

Factors associated with male involvement in reproductive care in Bangladesh

Directory of Open Access Journals (Sweden)

Ghose Bishwajit

2017-01-01

Full Text Available Abstract Background Men’s active involvement in reproductive healthcare has shown to be positively associated with maternal and child health outcomes. Bangladesh has made appreciable progress in its pursuance of maternal mortality related goals in the framework of the MDGs. However, there remains a lot to be accomplished to realise the long-term goals for which active participation of male counterparts in reproductive care is crucial. Therefore, the objective of the present study was to investigate factors associated with male involvement in reproductive health among Bangladeshi men. Methods We used data from Bangladesh Demographic and Health Survey (BDHS conducted in 2011. Study participants were 1196 married men, aged between 15 and 69 years and living in both urban and rural households. Level of male involvement (outcome variable was measured based on the responses on knowledge, awareness and practice regarding reproductive health. Chi-square tests and multivariable logistic regression models were performed for data analysis. Results Out of 1196 participants, only 40% were found to be active about partners’ reproductive healthcare. Chi-square test showed significant association between active involvement and ever hearing about family planning (FP in television, learning about FP through community health events, community health workers and poster/billboard. Results from logistic regression analysis revealed that type of residency [p = 0.004, AOR = 0.666, 95% CI = 0.504–0.879], literacy [secondary/higher education- p = 0.006. AOR = 0.579, 95% CI = 0.165–0.509], learning about family planning from Newspaper [p < 0.001. AOR = 1.952, 95% CI = 1.429–2.664], and television [p = 0.017. AOR = 1.514 95% CI = 1.298–1.886], and having been communicated about family planning by community health workers [p = 0.017. AOR = 1.946, 95% CI = 1.129–3.356] were significantly associated

Endocrine regulation of the reproduction in crustaceans: Identification of potential targets for toxicants and environmental contaminants

Czech Academy of Sciences Publication Activity Database

Mazurová, E.; Hilscherová, Klára; Triebskorn, R.; Kohler, H.R.; Maršálek, Blahoslav; Bláha, Luděk

2008-01-01

Roč. 63, č. 2 (2008), s. 139-150 ISSN 0006-3088 Institutional research plan: CEZ:AV0Z60050516 Keywords : crustaceans * reproduction * endocrine disruption Subject RIV: EF - Botanics Impact factor: 0.406, year: 2008

[Protective effect of melatonin and epithalon on hypothalamic regulation of reproduction in female rats in its premature aging model and on estrous cycles in senescent animals in various lighting regimes].

Science.gov (United States)

Korenevsky, A V; Milyutina, Yu P; Bukalyov, A V; Baranova, Yu P; Vinogradova, I A; Arutjunyan, A V

2013-01-01

Potential neuroprotective effects of the pineal gland hormone melatonin and peptide preparation epitalon on estrous cycles and the central regulation of reproduction in female rats exposed to unfavourable environmental factors have been studied. Estrous cycles of young, mature and aging rats exposed to light pollution were described. The diurnal dynamics and daily mean content of biogenic amines in the hypothalamic areas responsible for gonadotropin-releasing hormone synthesis and secretion in animals of different age groups were investigated. An effect of a chemical factor on the noradrenergic system of the medial preoptic area and on the dopaminergic system of the median eminence with arcuate nuclei of the hypothalamus was studied in premature aging of reproduction model. Administration of the pineal gland peptide melatonin and peptide preparation epitalon was shown to be able to correct a number of impairments of the hypothalamic-pituitary-gonadal axis that can be observed, when the experimental animals were exposed to permanent artificial lighting and a neurotoxic xenobiotic 1,2-dimethylhydrazine. The data obtained testify to an important role of the pineal gland in the circadian signal formation needed for gonadotropin-releasing hormone in order to exert its preovulatory peak secretion and to the protective effect of melatonin and epitalon, which are able to reduce unfavourable environmental influences on reproduction of young and aging female rats.

VARIATIONS IN REPRODUCTIVE TOXICANT IDENTIFICATION

Energy Technology Data Exchange (ETDEWEB)

Simmons, F

2008-05-13

Reproductive toxicants are a very important class of compounds. They present unique hazards to those of child bearing ages, perform their 'dirty work' using a wide variety of mechanisms on a number of different organs, and are regulatorily important. Because of all of this, properly identifying reproductive toxicants is important, but fraught with difficulty. In this paper we will describe types or reproductive toxicants, their importance, and both mistakes and good practices that people who are not experts in reproductive toxicology may use in their attempts to identify them. Additionally, this paper will focus on chemical reproductive toxicants and will not address biological agents that could affect reproductive toxicity although many principles outlined here could be applied to that endeavor.

Immunohistochemical evidence for an endocrine/paracrine role for ghrelin in the reproductive tissues of sheep

Directory of Open Access Journals (Sweden)

Brown Yvonne A

2005-10-01

Full Text Available Abstract Background The gut hormone, ghrelin, is involved in the neuroendocrine and metabolic responses to hunger. In monogastric species, circulating ghrelin levels show clear meal-related and body weight-related changes. The pattern of secretion and its role in ruminant species is less clear. Ghrelin acts via growth hormone secretagogue receptors (GHSR-1a to alter food intake, fat utilization, and cellular proliferation. There is also evidence that ghrelin is involved in reproductive function. In the present study we used immunohistochemistry to investigate the presence of ghrelin and GHSR-1a in sheep reproductive tissues. In addition, we examined whether ghrelin and GHSR-1a protein expression is developmentally regulated in the adult and fetal ovine testis, and whether there is an association with markers of cellular proliferation, i.e. stem cell factor (SCF and proliferating cell nuclear antigen (PCNA. Methods Antibodies raised against ghrelin and its functional receptor, GHSR-type 1a, were used in standard immunohistochemical protocols on various reproductive tissues collected from adult and fetal sheep. GHSR-1a mRNA presence was also confirmed by in situ hybridisation. SCF and PCNA immunoexpression was investigated in fetal testicular samples. Adult and fetal testicular immunostaining for ghrelin, GHSR-1a, SCF and PCNA was analysed using computer-aided image analysis. Image analysis data were subjected to one-way ANOVA, with differences in immunostaining between time-points determined by Fisher's least significant difference. Results In adult sheep tissue, ghrelin and GHSR-1a immunostaining was detected in the stomach (abomasum, anterior pituitary gland, testis, ovary, and hypothalamic and hindbrain regions of the brain. In the adult testis, there was a significant effect of season (photoperiod on the level of immunostaining for ghrelin (p Conclusion Evidence is presented for the presence of ghrelin and its receptor in various reproductive

A novel 3-hydroxysteroid dehydrogenase that regulates reproductive development and longevity.

Directory of Open Access Journals (Sweden)

Joshua Wollam

Full Text Available Endogenous small molecule metabolites that regulate animal longevity are emerging as a novel means to influence health and life span. In C. elegans, bile acid-like steroids called the dafachronic acids (DAs regulate developmental timing and longevity through the conserved nuclear hormone receptor DAF-12, a homolog of mammalian sterol-regulated receptors LXR and FXR. Using metabolic genetics, mass spectrometry, and biochemical approaches, we identify new activities in DA biosynthesis and characterize an evolutionarily conserved short chain dehydrogenase, DHS-16, as a novel 3-hydroxysteroid dehydrogenase. Through regulation of DA production, DHS-16 controls DAF-12 activity governing longevity in response to signals from the gonad. Our elucidation of C. elegans bile acid biosynthetic pathways reveals the possibility of novel ligands as well as striking biochemical conservation to other animals, which could illuminate new targets for manipulating longevity in metazoans.

Leptin and Reproduction: Past Milestones, Present Undertakings and Future Endeavors

Science.gov (United States)

Chehab, Farid F.

2014-01-01

The association between leptin and reproduction originated with the leptin-mediated correction of sterility in ob/ob mice and initiation of reproductive function in normal female mice. The uncovering of a central leptin pathway regulating food intake prompted the dissection of neuroendocrine mechanisms involving leptin in the metabolic control of reproduction. The absence of leptin receptors on GnRH neurons incited a search for intermediary neurons situated between leptin responsive and GnRH neurons. This review addresses the most significant findings that have furthered our understanding of recent progress in this new field. The role of leptin in puberty was impacted by the discovery of neurons that co-express kisspeptin, neurokinin B and dynorphin and that could act as leptin intermediates. Furthermore, the identification of first-order leptin-responsive neurons in the premammilary ventral nucleus and other brain regions opens new avenues to explore their relationship to GnRH neurons. Central to these advances is the unveiling that AgRP/NPY neurons project onto GnRH and kisspeptin neurons, allowing a crosstalk between food intake and reproduction. Finally, whereas puberty is a state of leptin sensitivity, mid-gestation represents a state of leptin resistance aimed at building energy stores to sustain pregnancy and lactation. Mechanisms underlying leptin resistance in pregnancy have lagged, however the establishment of this natural state is significant. Reproduction and energy balance are tightly controlled and backed up by redundant mechanisms that are critical for the survival of our species. It will be the goal of the next decade to shed new light on these complex and essential pathways. PMID:25118207

Discovery of a secular trend in Cayo Santiago macaque reproduction.

Science.gov (United States)

Hernández-Pacheco, Raisa; Rawlins, Richard G; Kessler, Matthew J; Delgado, Diana L; Ruiz-Lambides, Angelina V; Sabat, Alberto M

2016-02-01

Reproductive synchrony and the consequent clustering of births are hypothesized to be regulated by seasonal changes in rainfall and food availability. Such climate-related seasonality is, however, questionable in tropical populations occupying temporally invariant habitats year round. Using the long-term data of the Cayo Santiago rhesus macaques from 1973 to 2013, this study distinguishes synchrony (a greater than chance clustering of births) from seasonality (a cluster of births during a period of the year when abiotic conditions are favorable) and shows that females are highly synchronized (>72% of births in a 3-month period) but the effects of environmental zeitgebers on reproduction are overridden by biological factors. Specifically, biotic and abiotic factors including (i) loss of immature offspring; (ii) population density; (iii) age at delivery; (iv) rainfall; and (v) changes in colony management were modeled in relation to the annual onset of births and the median birth date. Females experiencing loss of immature offspring had an interbirth interval of trend in both the onset of births and the median date of birth is documented and the model predicts that the median birth date will advance across all calendar-based seasons by 2050. The secular trend in reproduction appears to be triggered by changes in the age at delivery of females, the absence of physiological constraints from maternal investment due to offspring loss, shorter interbirth interval, and a higher degree of coordination due to increasing population density. This study challenges the reproductive phenology previously described for rhesus macaques highlighting the importance of long-term studies in addressing the ultimate causes of reproductive synchrony. © 2015 Wiley Periodicals, Inc.

ANABOLIC ANDROGENIC STEROIDS AND ADVERSE EVENTS OF THEIR APPLICATION

Directory of Open Access Journals (Sweden)

Nina Đukanović

2011-08-01

Full Text Available Anabolic androgenic steroids are synthetic compounds originating from testosterone. Their main effects are the control of development and expression of male secondary sexual characteristics, which are known as androgenic effects, and encourage muscle growth or anabolic effects. Anabolic androgenic steroids are most commonly used illegal substances. Besides these physiological effects, which are achieved using therapeutic doses of these preparations, higher doses than recommended, especially over the longer term, may be associated with the emergence of numerous adverse events. Adverse events may be registered in almost all organs and organ systems, but usually include changes in the reproductive system, skin, liver and cardiovascular system.

Licensee Event Report (LER) compilation, December 1991

International Nuclear Information System (INIS)

1992-01-01

This monthly report contains licensee event report (LER) operational information that was processed into the LER data file of the Nuclear Safety Information Center (NSIC) during the one month period identified on the cover of the document. The LERs, from which this information is derived, are submitted to the Nuclear Regulatory Commission (NRC) by nuclear power plant licensees in accordance with federal regulations. Procedures for LER reporting for revisions to those events occurring prior to 1984 are described in NRC Regulatory Guide 1.16 and NUREG-0161, Instructions for Preparation of Data Entry Sheets for Licensee Event Reports. For those events occurring on and after January 1, 1984, LERs are being submitted in accordance with the revised rule contained in Title 10 Part 50.73 of the Code of Federal Regulations (10 CFR 50.73 - Licensee Event Report System) which was published in the Federal Register (Vol. 48, No. 144) on July 26, 1983. NUREG-1022, Licensee Event Report System - Description of Systems and Guidelines for Reporting, provides supporting guidance and information on the revised LER rule

A policy analysis of the problem of the reproductive health of women in the workplace.

Science.gov (United States)

Kotch, J B; Ossler, C C; Howze, D C

1984-06-01

Many occupations in which women comprise the majority of the workforce involve exposure to biological, physical, and chemical hazards. Potential reproductive effects of work-related substances include impaired reproductive capacity, mutagenesis, teratogenesis, and transplacental carcinogenesis. However, female-dominated occupations tend to be only minimally regulated by the US Occupational Safety and Health Administration, and the corporate response to the issue of reproductive and fetal health has been to institute "protective discrimination policies" such as the demotion or exclusion of women of childbearing age from certain jobs. This article rates the effectiveness of alternate policy responses to increase women's occupational health and safety through use of a series of analysis criteria: equity, efficiency, preference satisfaction, right to privacy, avoidance of stigma, and unintended consequences. Policy options include the following: 1) do nothing, 2) leave current policies intact while supporting a research program to document the health consequences of specific occupational risks to women's reproductive health, 3) restrict women for who pregnancy is not ruled out from occupations or work areas known or suspected to be hazardous, 4) improve working conditions for all women, and 5) improve working conditions for all workers. Policy analysis suggests the working conditions of all workers should be improved. This alternative reduces inequity, eliminates stigma, maintains privacy, and honors preferences. Implementation of this policy would be expensive, requiring an increase in knowledge of the effects of industrial substances on female and male reproductive health, expansion of the technical capacity to control occupational hazards, and an increase in the resources of programs that monitor and regulate occupational health. However, this approach is in accord with growing concern that workers should not have to compromise their health to keep their jobs.

Effect of Ppd-1 on the expression of flowering-time genes in vegetative and reproductive growth stages of wheat.

Science.gov (United States)

Kitagawa, Satoshi; Shimada, Sanae; Murai, Koji

2012-01-01

The photoperiod sensitivity gene Ppd-1 influences the timing of flowering in temperate cereals such as wheat and barley. The effect of Ppd-1 on the expression of flowering-time genes was assessed by examining the expression levels of the vernalization genes VRN1 and VRN3/WFT and of two CONSTANS-like genes, WCO1 and TaHd1, during vegetative and reproductive growth stages. Two near-isogenic lines (NILs) were used: the first carried a photoperiod-insensitive allele of Ppd-1 (Ppd-1a-NIL), the other, a photoperiod-sensitive allele (Ppd-1b-NIL). We found that the expression pattern of VRN1 was similar in Ppd-1a-NIL and Ppd-1b-NIL plants, suggesting that VRN1 is not regulated by Ppd-1. Under long day conditions, VRN3/WFT showed similar expression patterns in Ppd-1a-NIL and Ppd-1b-NIL plants. However, expression differed greatly under short day conditions: VRN3/WFT expression was detected in Ppd-1a-NIL plants at the 5-leaf stage when they transited from vegetative to reproductive growth; very low expression was present in Ppd-1b-NIL throughout all growth stages. Thus, the Ppd-1b allele acts to down-regulate VRN3/WFT under short day conditions. WCO1 showed high levels of expression at the vegetative stage, which decreased during the phase transition and reproductive growth stages in both Ppd-1a-NIL and Ppd-1b-NIL plants under short day conditions. By contrast to WCO1, TaHd1 was up-regulated during the reproductive stage. The level of TaHd1 expression was much higher in Ppd-1a-NIL than the Ppd-1b-NIL plants, suggesting that the Ppd-1b allele down-regulates TaHd1 under short day conditions. The present study indicates that down-regulation of VRN3/WFT together with TaHd1 is the cause of late flowering in the Ppd-1b-NIL plants under short day conditions.

Reproductive effects on skeletal health in Shuar women of Amazonian Ecuador: a life history perspective.

Science.gov (United States)

Madimenos, Felicia C; Snodgrass, J Josh; Liebert, Melissa A; Cepon, Tara J; Sugiyama, Lawrence S

2012-01-01

Clinical and epidemiological research suggest that bone mineral density (BMD) in women is shaped by various reproductive factors such as parity and lactation patterns. However, the extent of these effects on BMD remains unclear because of contradictory findings and a focus on industrialized populations. Because fertility patterns in these groups are vastly different than those of women from non-Western, subsistence populations, our current understanding of the reproductive effects on skeletal health is incomplete. Using a life history perspective, this study examines the relationship between reproductive factors and bone density among women from the Indigenous Shuar population, an Amazonian Ecuadorian forager-horticulturalist group. This preliminary, cross-sectional study included 130 premenopausal and postmenopausal women (14-86 years old) from the Morona-Santiago region of Ecuador. Anthropometrics were recorded, as was estimated BMD using a calcaneal ultrasonometer. A reproductive history questionnaire was administered that included questions regarding menarche, parity, lactation patterns, and menopause. Among postmenopausal women, early menarche and greater stature were significantly associated with higher bone density values. Among premenopausal women, few significant relationships between bone values and reproductive variables were documented; effects of lactation appeared to be transient and restored following weaning. Although preliminary and not based on longitudinal data, these findings suggest that the effects of reproduction are transient as the system of calcium homeostasis in premenopausal women efficiently restores the bone loss that results from metabolically active reproductive states. Further, this research suggests that the timing of early life history events may canalize bone density phenotype. Copyright © 2012 Wiley Periodicals, Inc.

Differential Regulation of Two-Tiered Plant Immunity and Sexual Reproduction by ANXUR Receptor-Like Kinases.

Science.gov (United States)

Mang, Hyunggon; Feng, Baomin; Hu, Zhangjian; Boisson-Dernier, Aurélien; Franck, Christina M; Meng, Xiangzong; Huang, Yanyan; Zhou, Jinggeng; Xu, Guangyuan; Wang, Taotao; Shan, Libo; He, Ping

2017-12-01

Plants have evolved two tiers of immune receptors to detect infections: cell surface-resident pattern recognition receptors (PRRs) that sense microbial signatures and intracellular nucleotide binding domain leucine-rich repeat (NLR) proteins that recognize pathogen effectors. How PRRs and NLRs interconnect and activate the specific and overlapping plant immune responses remains elusive. A genetic screen for components controlling plant immunity identified ANXUR1 (ANX1), a malectin-like domain-containing receptor-like kinase, together with its homolog ANX2, as important negative regulators of both PRR- and NLR-mediated immunity in Arabidopsis thaliana ANX1 constitutively associates with the bacterial flagellin receptor FLAGELLIN-SENSING2 (FLS2) and its coreceptor BRI1-ASSOCIATED RECEPTOR KINASE1 (BAK1). Perception of flagellin by FLS2 promotes ANX1 association with BAK1, thereby interfering with FLS2-BAK1 complex formation to attenuate PRR signaling. In addition, ANX1 complexes with the NLR proteins RESISTANT TO PSEUDOMONAS SYRINGAE2 (RPS2) and RESISTANCE TO P. SYRINGAE PV MACULICOLA1. ANX1 promotes RPS2 degradation and attenuates RPS2-mediated cell death. Surprisingly, a mutation that affects ANX1 function in plant immunity does not disrupt its function in controlling pollen tube growth during fertilization. Our study thus reveals a molecular link between PRR and NLR protein complexes that both associate with cell surface-resident ANX1 and uncovers uncoupled functions of ANX1 and ANX2 during plant immunity and sexual reproduction. © 2017 American Society of Plant Biologists. All rights reserved.

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

Reproduction impairment and endocrine disruption in female zebrafish after long-term exposure to MC-LR: A life cycle assessment

International Nuclear Information System (INIS)

Hou, Jie; Li, Li; Wu, Ning; Su, Yujing; Lin, Wang; Li, Guangyu; Gu, Zemao

2016-01-01

Microcystin-LR (MC-LR) has been found to cause reproductive and developmental impairments as well as to disrupt sex hormone homeostasis of fish during acute and sub-chronic toxic experiments. However, fish in natural environments are continuously exposed to MC-LR throughout their entire life cycle as opposed to short-term exposure. Here, we tested the hypothesis that the mechanism by which MC-LR harms female fish reproduction and development within natural water bodies is through interference of the reproductive endocrine system. In the present study, zebrafish hatchlings (5 d post-fertilization) were exposed to 0, 0.3, 3 and 30 μg/L MC-LR for 90 d until reaching sexual maturity. Female zebrafish were selected, and the changes in growth and developmental indicators, ovarian ultrastructure as well as the levels of gonadal steroid hormones and vitellogenin (VTG) were examined along with the transcription of related genes in the hypothalamic–pituitary–gonadal–liver axis (HPGL-axis). The results showed for the first time, a life cycle exposure to MC-LR caused growth inhibition, decreased ovary weight and ovarian ultra-pathological lesions. Decreased ovarian testosterone levels indicated that MC-LR disrupted sex steroid hormone balance. Significantly up-regulated transcription of brain FSHβ and LHβ along with ovarian ERα, FSHR and LHR suggested positive feedback regulation in the HPGL-axis was induced as a compensatory mechanism for MC-LR damage. It was also noted that ovarian VTG content and hepatic ERα and VTG1 expression were all down-regulated, which might be responsible for reduced vitellus storage noted in our histological observations. Our findings indicate that a life cycle exposure to MC-LR impairs the development and reproduction of female zebrafish by disrupting the transcription of related HPGL-axis genes, suggesting that MC-LR has potential adverse effects on fish reproduction and thus population dynamics in MCs-contaminated aquatic

Identification of genes associated with reproduction in the Mud Crab (Scylla olivacea) and their differential expression following serotonin stimulation.

Science.gov (United States)

Kornthong, Napamanee; Cummins, Scott F; Chotwiwatthanakun, Charoonroj; Khornchatri, Kanjana; Engsusophon, Attakorn; Hanna, Peter J; Sobhon, Prasert

2014-01-01

The central nervous system (CNS) is often intimately involved in reproduction control and is therefore a target organ for transcriptomic investigations to identify reproduction-associated genes. In this study, 454 transcriptome sequencing was performed on pooled brain and ventral nerve cord of the female mud crab (Scylla olivacea) following serotonin injection (5 µg/g BW). A total of 197,468 sequence reads was obtained with an average length of 828 bp. Approximately 38.7% of 2,183 isotigs matched with significant similarity (E value reproductive-related genes, namely farnesoic acid o-methyltransferase (FAMeT), estrogen sulfotransferase (ESULT) and prostaglandin F synthase (PGFS). Following serotonin injection, which would normally initiate reproductive processes, we found up-regulation of FAMeT, ESULT and PGFS expression in the female CNS and ovary. Our data here provides an invaluable new resource for understanding the molecular role of the CNS on reproduction in S. olivacea.

Androgens and the male reproductive tract: an overview of classical roles and current perspectives.

Science.gov (United States)

Patrão, Marilia T C C; Silva, Erick J R; Avellar, Maria Christina W

2009-11-01

Androgens are steroid hormones that play key roles in the development and maintenance of male phenotype and reproductive function. These hormones also affect the function of several non-reproductive organs, such as bone and skeletal muscle. Endogenous androgens exert most of their effects by genomic mechanisms, which involve hormone binding to the androgen receptor (AR), a ligand-activated transcription factor, resulting in the modulation of gene expression. AR-induced non-genomic mechanisms have also been reported. A large number of steroidal and non-steroidal AR-ligands have been developed for therapeutic use, including the treatment of male hypogonadism (AR agonists) and prostate diseases (AR antagonists), among other pathological conditions. Here, the AR gene and protein structure, mechanism of action and AR gene homologous regulation were reviewed. The AR expression pattern, its in vivo regulation and physiological relevance in the developing and adult testis and epididymis, which are sites of sperm production and maturation, respectively, were also presented.

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

Reproductive strategies in snakes.

OpenAIRE

Shine, Richard

2003-01-01

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 thermoreg...

Reproductive arrest and stress resistance in winter-acclimated Drosophila suzukii.

Science.gov (United States)

Toxopeus, Jantina; Jakobs, Ruth; Ferguson, Laura V; Gariepy, Tara D; Sinclair, Brent J

2016-06-01

Overwintering insects must survive the multiple-stress environment of winter, which includes low temperatures, reduced food and water availability, and cold-active pathogens. Many insects overwinter in diapause, a developmental arrest associated with high stress tolerance. Drosophila suzukii (Diptera: Drosophilidae), spotted wing drosophila, is an invasive agricultural pest worldwide. Its ability to overwinter and therefore establish in temperate regions could have severe implications for fruit crop industries. We demonstrate here that laboratory populations of Canadian D. suzukii larvae reared under short-day, low temperature, conditions develop into dark 'winter morph' adults similar to those reported globally from field captures, and observed by us in southern Ontario, Canada. These winter-acclimated adults have delayed reproductive maturity, enhanced cold tolerance, and can remain active at low temperatures, although they do not have the increased desiccation tolerance or survival of fungal pathogen challenges that might be expected from a more heavily melanised cuticle. Winter-acclimated female D. suzukii have underdeveloped ovaries and altered transcript levels of several genes associated with reproduction and stress. While superficially indicative of reproductive diapause, the delayed reproductive maturity of winter-acclimated D. suzukii appears to be temperature-dependent, not regulated by photoperiod, and is thus unlikely to be 'true' diapause. The traits of this 'winter morph', however, likely facilitate overwintering in southern Canada, and have probably contributed to the global success of this fly as an invasive species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polymorphisms of the myostatin gene and its relationship with reproduction traits in the Bian chicken.

Science.gov (United States)

Zhang, Genxi; Zhang, Li; Wei, Yue; Wang, Jinyu; Ding, Fuxiang; Dai, Guojun; Xie, Kaizhou

2012-01-01

Myostatin, or growth and differentiation factor 8, is a member of the transforming growth factor-β superfamily; it functions as a negative regulator of skeletal muscle development and growth in mammals. In this study, single nucleotide polymorphisms in the 5' regulatory region and exon 1 of the myostatin gene were detected by PCR-SSCP in the Bian, Jinghai, Youxi, and Arbor Acre chickens, and the associations of the polymorphisms with reproduction traits were analyzed. Seven SNPs (A326G, C334G, C1346T, G1375A, A1473G, G1491A, and G2283A) were found in the myostatin gene. Association analysis showed that the G2283A were significantly associated with reproduction traits. Bian chickens of the GG genotype had a greater age at first egg than those of the GA and AA genotypes (Pchickens of the GA and AA genotypes had larger egg number at 300 days than those of the GG genotype (Pchickens of the AA genotype had significantly higher body weight at 300 days than those of the GG genotype (P<0.05). These results suggested that the myostatin gene may have certain effects on reproduction traits other than merely as a negative regulator of skeletal muscle development and growth in mammals previously reported.

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

Effects of season and regulated photoperiod on the reproductive ...

African Journals Online (AJOL)

user

constant photoperiod (10 h light and 14 h darkness) and control sows (n = 187) ... Keywords: Season, regulated photoperiod, return to oestrus, farrowing rate, litter size .... were exposed to a minimum daylight cycle of 10.4 h during winter and a ...

Female Reproductive System (For Teens)

Science.gov (United States)

... of the Female Reproductive System Print en español Sistema reproductor femenino Reproduction All living things reproduce. Reproduction — ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on TeensHealth® is for ...

Fungal Meiosis and Parasexual Reproduction – Lessons from Pathogenic Yeast

OpenAIRE

Sherwood, Racquel K.; Bennett, Richard J.

2009-01-01

Meiosis is an integral part of sexual reproduction in eukaryotic species. It performs the dual functions of halving the genetic content in the cell, as well as increasing genetic diversity by promoting recombination between chromosome homologs. Despite extensive studies of meiosis in model yeast, it is now apparent that both the regulation of meiosis and the machinery mediating recombination has significantly diverged, even between closely related species. To highlight this, we discuss new st...

The survival-reproduction association becomes stronger when conditions are good.

Science.gov (United States)

Robert, Alexandre; Bolton, Mark; Jiguet, Frédéric; Bried, Joël

2015-11-07

Positive covariations between survival and reproductive performance (S-R covariation) are generally interpreted in the context of fixed or dynamic demographic heterogeneity (i.e. persistent differences between individuals, or dynamic variation in resource acquisition), but the processes underlying covariations are still unknown. We used multi-event modelling to investigate how environmental and individual features influence S-R covariation patterns in a long-lived seabird, the Monteiro's storm petrel (Oceanodroma monteiroi). Our analysis reveals that a strong positive association between individual breeding success and subsequent survival occurs only when conditions are favourable to reproduction (in favourable years, in high-quality nests and in nest-faithful breeders). This finding reflects differences in the main causes of breeding failure and mortality under favourable and unfavourable conditions, which in turn lead to distinct patterns of S-R covariation. We suggest, in particular, that resource-related sources of demographic heterogeneity do not generate a strong S-R covariation, in contrast with hidden and unpredictable sources of variation. © 2015 The Author(s).

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.