Science.gov

Sample records for affecting reproductive output

  1. Maternal nutrition affects reproductive output and sex allocation in a lizard with environmental sex determination.

    PubMed

    Warner, Daniel A; Lovern, Matthew B; Shine, Richard

    2007-03-22

    Life-history traits such as offspring size, number and sex ratio are affected by maternal feeding rates in many kinds of animals, but the consequences of variation in maternal diet quality (rather than quantity) are poorly understood. We manipulated dietary quality of reproducing female lizards (Amphibolurus muricatus; Agamidae), a species with temperature-dependent sex determination, to examine strategies of reproductive allocation. Females maintained on a poor-quality diet produced fewer clutches but massively (twofold) larger eggs with lower concentrations of yolk testosterone than did conspecific females given a high-quality diet. Although all eggs were incubated at the same temperature, and yolk steroid hormone levels were not correlated with offspring sex, the nutrient-deprived females produced highly male-biased sex ratios among their offspring. These responses to maternal nutrition generate a link between sex and offspring size, in a direction likely to enhance maternal fitness if large body size enhances reproductive success more in sons than in daughters (as seems plausible, given the mating system of this species). Overall, our results show that sex determination in these animals is more complex, and responsive to a wider range of environmental cues, than that suggested by the classification of 'environmental sex determination'. PMID:17251109

  2. Maternal nutrition affects reproductive output and sex allocation in a lizard with environmental sex determination

    PubMed Central

    Warner, Daniel A; Lovern, Matthew B; Shine, Richard

    2007-01-01

    Life-history traits such as offspring size, number and sex ratio are affected by maternal feeding rates in many kinds of animals, but the consequences of variation in maternal diet quality (rather than quantity) are poorly understood. We manipulated dietary quality of reproducing female lizards (Amphibolurus muricatus; Agamidae), a species with temperature-dependent sex determination, to examine strategies of reproductive allocation. Females maintained on a poor-quality diet produced fewer clutches but massively (twofold) larger eggs with lower concentrations of yolk testosterone than did conspecific females given a high-quality diet. Although all eggs were incubated at the same temperature, and yolk steroid hormone levels were not correlated with offspring sex, the nutrient-deprived females produced highly male-biased sex ratios among their offspring. These responses to maternal nutrition generate a link between sex and offspring size, in a direction likely to enhance maternal fitness if large body size enhances reproductive success more in sons than in daughters (as seems plausible, given the mating system of this species). Overall, our results show that sex determination in these animals is more complex, and responsive to a wider range of environmental cues, than that suggested by the classification of ‘environmental sex determination’. PMID:17251109

  3. Male Aedes aegypti mosquitoes use JH III transferred during copulation to influence previtellogenic ovary physiology and affect the reproductive output of female mosquitoes.

    PubMed

    Clifton, Mark E; Correa, Stefano; Rivera-Perez, Crisalejandra; Nouzova, Marcela; Noriega, Fernando G

    2014-05-01

    The effect of male accessory gland substances on female reproductive physiology has been previously described as "activating" egg development. However, no mechanism has been described that can explain how male mosquitoes are able to influence egg development in female mosquitoes. To investigate how male mosquitoes are able to influence ovarian physiology and reproductive output we explored three main questions: (1) Do mating and male accessory gland substances affect ovarian physiology and alter markers of oocyte quality during the previtellogenic resting stage? (2) Does the male accessory gland contain JH III and is JH III transferred to the female during copulation? (3) Finally, does the nutritional history of the male affect the amount of JH III transferred to the female and alter reproductive output? By answering these questions it is clear that male mosquitoes are able to alter the female's resource allocation priorities towards reproduction by transferring JH III during copulation; reducing the rate of previtellogenic resorption and increasing the amount of stored ovarian lipids. These changes improve an individual follicle's likelihood of development after a blood meal. In addition, males maintained under better nutritional conditions make and transfer more JH III, prevent more follicular resorption and realize higher fecundities than other males. Together these results illustrate one mechanism behind the "activating" effect of mating described as well as the role sugar feeding plays in male mosquitoes. PMID:24657670

  4. Elevated corticosterone levels decrease reproductive output of chick-rearing Adélie penguins but do not affect chick mass at fledging

    PubMed Central

    Thierry, Anne-Mathilde; Ropert-Coudert, Yan; Raclot, Thierry

    2013-01-01

    Study of physiological mechanisms can help us to understand how animals respond to changing environmental conditions. In particular, stress hormones (i.e. glucocorticoids, such as corticosterone) are described as mediating resource allocation, allowing animals to adjust their physiology and behaviour to predictable and unpredictable changes in the environment. In this study, we investigated the effects of an experimental increase in baseline corticosterone levels on the breeding effort and the reproductive output of chick-rearing male Adélie penguins (Pygoscelis adeliae). The number of chicks per nest, their body mass, and their size were monitored throughout the study. Direct observations allowed measurement of the time spent foraging at sea and caring for the young on the nest. At the end of the treatment, blood samples were collected for isotope analysis. Although all birds raised at least one chick, reproductive output was decreased by 42% in corticosterone-treated birds compared with control birds. The increase in corticosterone levels during the guard stage did not affect the mass of surviving chicks or the brood mass at fledging. Corticosterone-treated males spent on average 21% more time at the nest than control birds. However, the duration of foraging trips was similar between both groups. In addition, the similarity of isotopic signatures suggests that both groups foraged at similar locations and ingested the same prey species. The detailed on-land behaviour of birds should be examined in further studies to clarify the possible links between corticosterone levels, brooding time, and reproductive output. Understanding the relationships between glucocorticoids, fitness, and ultimately population dynamics is fundamental to enabling conservation physiology as a discipline to be successful in helping to manage species of conservation concern. PMID:27293591

  5. We Made Your Bed, Why Won't You Lie in It? Food Availability and Disease May Affect Reproductive Output of Reintroduced Frogs.

    PubMed

    Klop-Toker, Kaya; Valdez, Jose; Stockwell, Michelle; Fardell, Loren; Clulow, Simon; Clulow, John; Mahony, Michael

    2016-01-01

    Mitigation to offset the impacts of land development is becoming increasingly common, with reintroductions and created habitat programs used as key actions. However, numerous reviews cite high rates of poor success from these programs, and a need for improved monitoring and scientific testing to evaluate outcomes and improve management actions. We conducted extensive monitoring of a released population of endangered green and golden bell frogs, Litoria aurea, within a created habitat, as well as complementary surveys of a surrounding wild population. We then compared differences between the created habitat and natural ponds where extant frogs either bred or didn't breed in order to determine factors that contributed to the breeding failure within the created habitat. We evaluated differences of L. aurea abundance, abundance of other fauna, vegetation, water quality, habitat structure, invasive fish, and disease between the three pond types (created habitat, breeding ponds, non-breeding ponds). We discovered that vegetation and invertebrate diversity were low within the created habitat, potentially reducing energy and nutritional resources required for breeding. Also, a greater proportion of frogs in the created habitat were carrying the chytrid fungal pathogen, Batrachochytrium dendrobatidis, compared to the wild populations. In addition to causing the potentially fatal disease, chytridiomycosis, this pathogen has been shown to reduce reproductive functioning in male L. aurea, and subsequently may have reduced reproductive activities in the created habitat. Conspecific attraction, pond hydrology, and aquatic vegetation may also have had some influence on breeding behaviours, whilst the presence of the invasive mosquitofish, Gambusia holbrooki, and heterospecific tadpoles were unlikely to have deterred L. aurea from breeding within the created habitat. Through the use of scientific testing and monitoring, this study is able to make recommendations for future

  6. We Made Your Bed, Why Won’t You Lie in It? Food Availability and Disease May Affect Reproductive Output of Reintroduced Frogs

    PubMed Central

    Valdez, Jose; Stockwell, Michelle; Fardell, Loren; Clulow, Simon; Clulow, John; Mahony, Michael

    2016-01-01

    Mitigation to offset the impacts of land development is becoming increasingly common, with reintroductions and created habitat programs used as key actions. However, numerous reviews cite high rates of poor success from these programs, and a need for improved monitoring and scientific testing to evaluate outcomes and improve management actions. We conducted extensive monitoring of a released population of endangered green and golden bell frogs, Litoria aurea, within a created habitat, as well as complementary surveys of a surrounding wild population. We then compared differences between the created habitat and natural ponds where extant frogs either bred or didn’t breed in order to determine factors that contributed to the breeding failure within the created habitat. We evaluated differences of L. aurea abundance, abundance of other fauna, vegetation, water quality, habitat structure, invasive fish, and disease between the three pond types (created habitat, breeding ponds, non-breeding ponds). We discovered that vegetation and invertebrate diversity were low within the created habitat, potentially reducing energy and nutritional resources required for breeding. Also, a greater proportion of frogs in the created habitat were carrying the chytrid fungal pathogen, Batrachochytrium dendrobatidis, compared to the wild populations. In addition to causing the potentially fatal disease, chytridiomycosis, this pathogen has been shown to reduce reproductive functioning in male L. aurea, and subsequently may have reduced reproductive activities in the created habitat. Conspecific attraction, pond hydrology, and aquatic vegetation may also have had some influence on breeding behaviours, whilst the presence of the invasive mosquitofish, Gambusia holbrooki, and heterospecific tadpoles were unlikely to have deterred L. aurea from breeding within the created habitat. Through the use of scientific testing and monitoring, this study is able to make recommendations for future

  7. Tree size and its relationship with flowering phenology and reproductive output in Wild Nutmeg trees.

    PubMed

    Otárola, Mauricio Fernández; Sazima, Marlies; Solferini, Vera N

    2013-09-01

    Reproductive strategies, sexual selection, and their relationship with the phenotype of individuals are topics widely studied in animals, but this information is less abundant for plants. Variability in flowering phenology among individuals has direct impact on their fitness, but how reproductive phenology is affected by the size of the individuals needs further study. We quantified the flowering intensity, length, and reproductive synchronization of two sympatric dioecious Wild Nutmeg tree species (Virola, Myristicaceae) in the Brazilian Atlantic forest, and analyzed its relationships with tree size. Two distinct strategies in flowering timing and intensity were found between species (annual versus biennial flowering), and among individuals in the annual flowering species (extended versus peak flowering). Only for the annual flowering species the reproductive output is related to tree size and large trees present proportionally higher flower coverage, and lower synchronization than smaller ones. Flowering is massive and highly synchronized in the biennial species. Sex ratios are not different from 1:1 in the two species, and in the two segregated reproductive subgroups in the biennial flowering species. The biennial flowering at individual level is a novelty among reproductive patterns in plants, separating the population in two reproductive subgroups. A proportional increase in the reproductive output with size exists only for the annual flowering species. A biennial flowering can allow resource storage favouring massive flowering for all the individuals diluting their relationship with size. PMID:24223288

  8. Comparative reproductive output of androphilic and gynephilic males in samoa.

    PubMed

    Vasey, Paul L; Parker, Jessica L; VanderLaan, Doug P

    2014-02-01

    Debate exists in the behavioral sciences regarding the extent to which androphilic males reproduce compared to their gynephilic counterparts. Quantitative data that might speak to this debate are surprisingly rare. Here, we compared the reproductive output of 235 transgendered, exclusively androphilic Samoan males (known locally as fa'afafine) to that of 447 exclusively gynephilic Samoan males. Samoan gynephilic male participants fathered significantly more children than fa'afafine participants. In fact, none of the fa'afafine in our sample produced offspring. On the basis of this evidence and anecdotal accounts in the anthropological literature, we contend that absence of reproductive output is a near absolute cross-cultural universal characterizing non-Western, transgendered androphilic ("third-gender") males. Models for the evolution of male androphilia must account for how genes associated with this sexual orientation originated in the past and persisted in populations over time despite the fact that the vast majority of androphilic males have no direct reproductive success. PMID:24132776

  9. Life span, reproductive output, and reproductive opportunity in captive Goeldi's monkeys (Callimico goeldii).

    PubMed

    Nuss, Kara; Warneke, Mark

    2010-01-01

    In the absence of long-term field studies, demographic and reproductive records from animals housed in zoos and research laboratories are a valuable tool for the study of life history variables relating to reproduction. In this study, we analyzed studbook records of more than 2,000 individuals born over a 40-year period (1965-2004) to describe life history patterns of captive Goeldi's monkeys (Callimico goeldii) housed in North America and Europe. Using Kaplan-Meier survival analysis methods, we found the mean life span to be 5.5 years. The rate of infant mortality, defined as death before 30 days, was approximately 30%, with European animals being more likely to survive infancy than North American animals. When individuals surviving at least 1.5 years are considered, lifetime reproductive output averaged 3.5 offspring, yet more than one-third of individuals did not produce any offspring. Using a smaller dataset of individuals with known pairing histories, we developed a measure of opportunity for reproduction (OFR), which represented the total time an individual was known to be housed with a potential mate. For both sexes, we found that the correlation between OFR and number of offspring produced was much higher than the correlation between life span and number of offspring produced. This result highlights the importance of taking into account an individual's OFR. As a whole, our findings help characterize the life histories of captive Goeldi's monkeys and emphasize the impact management practices may have on reproductive success. PMID:20131357

  10. Input and output constraints affecting irrigation development

    NASA Astrophysics Data System (ADS)

    Schramm, G.

    1981-05-01

    In many of the developing countries the expansion of irrigated agriculture is used as a major development tool for bringing about increases in agricultural output, rural economic growth and income distribution. Apart from constraints imposed by water availability, the major limitations considered to any acceleration of such programs are usually thought to be those of costs and financial resources. However, as is shown on the basis of empirical data drawn from Mexico, in reality the feasibility and effectiveness of such development programs is even more constrained by the lack of specialized physical and human factors on the input and market limitations on the output side. On the input side, the limited availability of complementary factors such as, for example, truly functioning credit systems for small-scale farmers or effective agricultural extension services impose long-term constraints on development. On the output side the limited availability, high risk, and relatively slow growth of markets for high-value crops sharply reduce the usually hoped-for and projected profitable crop mix that would warrant the frequently high costs of irrigation investments. Three conclusions are drawn: (1) Factors in limited supply have to be shadow-priced to reflect their high opportunity costs in alternative uses. (2) Re-allocation of financial resources from immediate construction of projects to longer-term increase in the supply of scarce, highly-trained manpower resources are necessary in order to optimize development over time. (3) Inclusion of high-value, high-income producing crops in the benefit-cost analysis of new projects is inappropriate if these crops could potentially be grown in already existing projects.

  11. The timing and reproductive output of the commercial sea cucumber Holothuria scabra on the Kenyan coast

    NASA Astrophysics Data System (ADS)

    Muthiga, N. A.; Kawaka, J. A.; Ndirangu, S.

    2009-09-01

    The sea cucumber Holothuria scabra is a widely distributed and economically important species that has been harvested in Kenya for decades. No previous studies have been carried out on the reproduction of this species in Kenya. Standard gonad index methods were used to analyze reproductive patterns of individuals collected monthly in 1998-1999, 2000-2001 and 2006-2007. Morphological characteristics, gonad tubule lengths and fecundity were also measured. Mean monthly gonad indices were significantly correlated between males and females indicating synchronous gonad development between the sexes. Gonad indices showed a biannual pattern that was consistent in all three years with a minor spawning event occurring between August and September and a major spawning event between November and December. The pattern of gonad growth showed significant variability between years and between months. Temporal changes in gonad growth correlated significantly with gonad tubule length and absolute fecundity. Monthly gonad indices also correlated significantly with monthly measurements of air temperature and light suggesting a possible role for both factors in timing gametogenesis and spawning. There was a shift in sex ratio from unity in the 1998-1999 and 2000-2001 samples to significantly more males in the 2006-2007 samples, as well as a significant reduction in mean sizes (body wall weight) and reproductive output (gonad index) which suggests that the reproductive success of this species is potentially negatively affected by fishing.

  12. Does garbage in diet improve Glaucous Gull reproductive output?

    USGS Publications Warehouse

    Powell, Abby N.; Weiser, Emily L.

    2010-01-01

    Anthropogenic subsidies are used by a variety of predators in areas developed for human use or residence. If subsidies promote population growth, these predators can have a negative effect on local prey species. The Glaucous Gull (Larus hyperboreus) is an abundant predator in northern Alaska that is believed to benefit from garbage as a supplemental food source, but this supposition has never been tested. In summer 2008 and 2009, we recorded the Glaucous Gull's diet and reproduction at 10 breeding colonies in northern Alaska. Colonies were in industrial, residential, and undeveloped areas and ranged from 5 to 75 km from the nearest landfill. By colony, garbage occurred in zero to 85% of pellets and food remains produced during the chick-rearing period, and the average number of chicks fledged per pair ranged from zero to 2.9. Random-forest analysis indicated that percent occurrence of garbage in the diet was the second most important factor (after number of eggs per pair) explaining variance in fledging rate. There was a significant positive correlation between percent occurrence of garbage in the diet and fledging rate in each year. If this correlation reflects a causal relationship, it suggests that human development that increases gulls' access to garbage could result in increased local gull populations. Such an increase could affect the gulls' natural prey species, including at least 14 species of shorebirds and waterfowl of conservation concern.

  13. Effects of gastropod predation on the reproductive output of an overexploited deep octocoral

    NASA Astrophysics Data System (ADS)

    Priori, C.; Erra, F.; Angiolillo, M.; Santangelo, G.

    2015-03-01

    The study presented herein is aimed at quantifying the effects of the partial predation exerted by the gastropod Pseudosimnia carnea on the reproductive features of the highly valuable, slow-growing, and long-lived red coral, Corallium rubrum. Seventy-five colonies were collected just before annual spawning from a red coral population living between 85 and 90 m deep in the NW Mediterranean; of these, 35 % were affected by P. carnea. Female colonies were more frequently preyed upon than males (3:1 ratio). Overall, 1,100 polyps were dissected and examined for their reproductive content. The mean number of polyps per colony and the mean fecundity of female polyps and colonies were significantly reduced by gastropod predation, which affected colonies independently of their size; in particular, colony fecundity was reduced by 81 %. The consequent reduction in population reproductive output is likely to have long-term effects on preyed-upon populations and thereby limit their resilience to intense commercial harvesting.

  14. Leptin: a possible metabolic signal affecting reproduction.

    PubMed

    Spicer, L J

    2001-11-01

    Since its discovery in 1994, leptin, a protein hormone synthesized and secreted by adipose tissue, has been shown to regulate feed intake in several species including sheep and pigs. Although a nimiety of information exists regarding the physiological role of leptin in rodents and humans, the regulation and action of leptin in domestic animals is less certain. Emerging evidence in several species indicates that leptin may also affect the hypothalamo-pituitary-gonadal axis. Leptin receptor mRNA is present in the anterior pituitary and hypothalamus of several species, including sheep. In rats, effects of leptin on GnRH, LH and FSH secretion have been inconsistent, with leptin exhibiting both stimulatory and inhibitory action in vivo and in vitro. Evidence to support direct action of leptin at the level of the gonad indicates that the leptin receptor and its mRNA are present in ovarian tissue of several species, including cattle. These leptin receptors are functional, since leptin inhibits insulin-induced steroidogenesis of both granulosa and thecal cells of cattle in vitro. Leptin receptor mRNA is also found in the testes of rodents. As with the ovary, these receptors are functional, at least in rats, since leptin inhibits hCG-induced testosterone secretion by Leydig cells in vitro. During pregnancy, placental production of leptin may be a major contributor to the increase in maternal leptin in primates but not rodents. However, in both primates and rodents, leptin receptors exist in placental tissues and may regulate metabolism of the fetal-placental unit. As specific leptin immunoassays are developed for domestic animals, in vivo associations may then be made among leptin, body energy stores, dietary energy intake and reproductive function. This may lead to a more definitive role of leptin in domestic animal reproduction. PMID:11872320

  15. Factors affecting the reproductive success of dominant male meerkats.

    PubMed

    Spong, Göran F; Hodge, Sarah J; Young, Andrew J; Clutton-Brock, Tim H

    2008-05-01

    Identifying traits that affect the reproductive success of individuals is fundamental for our understanding of evolutionary processes. In cooperative breeders, a dominant male typically restricts mating access to the dominant female for extended periods, resulting in pronounced variation in reproductive success among males. This may result in strong selection for traits that increase the likelihood of dominance acquisition, dominance retention and reproductive rates while dominant. However, despite considerable research on reproductive skew, few studies have explored the factors that influence these three processes among males in cooperative species. Here we use genetic, behavioural and demographic data to investigate the factors affecting reproductive success in dominant male meerkats (Suricata suricatta). Our data show that dominant males sire the majority of all offspring surviving to 1 year. A male's likelihood of becoming dominant is strongly influenced by age, but not by weight. Tenure length and reproductive rate, both important components of dominant male reproductive success, are largely affected by group size and composition, rather than individual traits. Dominant males in large groups have longer tenures, but after this effect is controlled, male tenure length also correlates negatively to the number of adult females in the group. Male reproductive rate also declines as the number of intra- and extra-group competitors increases. As the time spent in the dominant position and reproductive rate while dominant explain > 80% of the total variance in reproductive success, group composition thus has major implications for male reproductive success. PMID:18410290

  16. Advantage of specialism: reproductive output is related to prey choice in a small raptor.

    PubMed

    Otterbeck, Andreas; Lindén, Andreas; Roualet, Éric

    2015-09-01

    Predatory species' usage of different prey types is affected by both prey availability and selectivity. The diet during the breeding season may affect the reproductive success of individual pairs. We studied the prey use of a small reversed size-dimorphic raptor, the Eurasian sparrowhawk Accipiter nisus, with respect to prey weight on two organizational levels. Using 13 years of data from southern Norway, we related reproductive output of individual breeding events to prey size taken. Further, we assessed the regional variation in prey usage between five Fennoscandian populations. This was done by fitting optimum-type functions to the prey species' numbers or relative predation risks. Pairs that successfully completed the season with more fledglings displayed less variation in prey size, suggesting a possible adaptive benefit of diet specialism, or possibly a correlative effect due to higher prey availability or lower female hunting effort. This finding contrasts with earlier raptor studies, which have suggested benefits of dietary (and hence nutritional) diversity. Indeed, our results might be limited to nutritionally substitutable prey items. We also found a tendency suggesting that older females raised more fledglings than 1-year-old females. In the population-level analysis, we found that optimum-type functions with constant width and spatially variable average best described the relationship between relative predation risk and log weight. This can reflect local conditions, such as prey availability. Our findings and new methodological tools could apply to a broader spectrum of predators. They also highlight the role of viewing usage or choice of prey at several spatial scales. PMID:25943192

  17. Loss of reproductive output caused by an invasive species

    PubMed Central

    Tremblay, Maude E. M.; Morris, Todd J.; Ackerman, Josef D.

    2016-01-01

    We investigated whether Neogobius melanostomus, an invader of biodiversity ‘hot-spots’ in the Laurentian Great Lakes region, facilitates or inhibits unionid mussel recruitment by serving as a host or sink for their parasitic larvae (glochidia). Infestation and metamorphosis rates of four mussel species with at-risk (conservation) status (Epioblasma torulosa rangiana, Epioblasma triquetra, Lampsilis fasciola and Villosa iris) and one common species (Actinonaias ligamentina) on N. melanostomus were compared with rates on known primary and marginal hosts in the laboratory. All species successfully infested N. melanostomus, but only E. triquetra, V. iris and A. ligamentina successfully metamorphosed into juveniles, albeit at very low rates well below those seen on even the marginal hosts. Neogobius melanostomus collected from areas of unionid occurrence in the Grand and Sydenham rivers (Ontario, Canada) exhibited glochidial infection rates of 39.4% and 5.1%, respectively, with up to 30 glochidia representing as many as six unionid species per fish. A mathematical model suggests that N. melanostomus serve more as a sink for glochidia than as a host for unionids, thereby limiting recruitment success. This represents a novel method by which an invasive species affects a native species. PMID:27152202

  18. Loss of reproductive output caused by an invasive species.

    PubMed

    Tremblay, Maude E M; Morris, Todd J; Ackerman, Josef D

    2016-04-01

    We investigated whether Neogobius melanostomus, an invader of biodiversity 'hot-spots' in the Laurentian Great Lakes region, facilitates or inhibits unionid mussel recruitment by serving as a host or sink for their parasitic larvae (glochidia). Infestation and metamorphosis rates of four mussel species with at-risk (conservation) status (Epioblasma torulosa rangiana, Epioblasma triquetra, Lampsilis fasciola and Villosa iris) and one common species (Actinonaias ligamentina) on N. melanostomus were compared with rates on known primary and marginal hosts in the laboratory. All species successfully infested N. melanostomus, but only E. triquetra, V. iris and A. ligamentina successfully metamorphosed into juveniles, albeit at very low rates well below those seen on even the marginal hosts. Neogobius melanostomus collected from areas of unionid occurrence in the Grand and Sydenham rivers (Ontario, Canada) exhibited glochidial infection rates of 39.4% and 5.1%, respectively, with up to 30 glochidia representing as many as six unionid species per fish. A mathematical model suggests that N. melanostomus serve more as a sink for glochidia than as a host for unionids, thereby limiting recruitment success. This represents a novel method by which an invasive species affects a native species. PMID:27152202

  19. Importance of multiple mating to female reproductive output in Diaphorina citri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluate the importance of multiple mating to female reproductive output in Diaphorina citri Kuwayama (Hemiptera: Psyllidae) by grouping individual females with one or three males for 24 h (short duration) or two weeks (long duration) and examining oviposition over 18-19 days. For the short durat...

  20. Meadow fragmentation and reproductive output of the SE Asian seagrass Enhalus acoroides [rapid communication

    NASA Astrophysics Data System (ADS)

    Vermaat, Jan E.; Rollon, Rene N.; Lacap, Cristina Day A.; Billot, Claire; Alberto, Filipe; Nacorda, Hildie M. E.; Wiegman, Frank; Terrados, Jorge

    2004-11-01

    Flower and fruit production of the abundant, tall, long-lived, dioecious, surface-pollinating seagrass species Enhalus acoroides (L.) Royle were estimated at seven sites in the reef flats off Bolinao (NW Luzon, The Philippines) featuring different fragmentation of the seagrass meadows. Fragmentation of the seagrass meadow was quantified as cover of E. acoroides and all seagrass species present in 20×20 m plots. E. acoroides and overall seagrass cover were correlated positively. The proportion of female flowers of E. acoroides that developed a fruit increased sharply as overall seagrass cover was around 50%. Apparent sex ratio bore no relationship with overall seagrass cover. This threshold-type of relationship suggests that fragmentation of seagrass meadows can have a major effect on the reproductive output of this species. A possible mechanism underlying these results would be a non-linear increase of the efficiency of trapping the surface-dispersed pollen with increasing seagrass canopy density. This provides the first evidence based on real data that fragmentation can affect the population dynamics of seagrass species.

  1. Herbivory strongly influences among-population variation in reproductive output of Lythrum salicaria in its native range.

    PubMed

    Lehndal, Lina; Hambäck, Peter A; Ericson, Lars; Ågren, Jon

    2016-04-01

    Herbivory can negatively affect several components of plant reproduction. Yet, because of a lack of experimental studies involving multiple populations, the extent to which differences in herbivory contribute to among-population variation in plant reproductive success is poorly known. We experimentally determined the effects of insect herbivory on reproductive output in nine natural populations of the perennial herb Lythrum salicaria along a disturbance gradient in an archipelago in northern Sweden, and we quantified among-population differentiation in resistance to herbivory in a common-garden experiment in the same area. The intensity of leaf herbivory varied >500-fold and mean female reproductive success >400-fold among the study populations. The intensity of herbivory was lowest in populations subject to strong disturbance from ice and wave action. Experimental removal of insect herbivores showed that the effect of herbivory on female reproductive success was correlated with the intensity of herbivory and that differences in insect herbivory could explain much of the among-population variation in the proportion of plants flowering and seed production. Population differentiation in resistance to herbivory was limited. The results demonstrate that the intensity of herbivory is a major determinant of flowering and seed output in L. salicaria, but that differences in herbivory are not associated with differences in plant resistance at the spatial scale examined. They further suggest that the physical disturbance regime may strongly influence the performance and abundance of perennial herbs and patterns of selection not only because of its effect on interspecific competition, but also because of effects on interactions with specialized herbivores. PMID:26678991

  2. Beyond R0: Demographic Models for Variability of Lifetime Reproductive Output

    PubMed Central

    Caswell, Hal

    2011-01-01

    The net reproductive rate measures the expected lifetime reproductive output of an individual, and plays an important role in demography, ecology, evolution, and epidemiology. Well-established methods exist to calculate it from age- or stage-classified demographic data. As an expectation, provides no information on variability; empirical measurements of lifetime reproduction universally show high levels of variability, and often positive skewness among individuals. This is often interpreted as evidence of heterogeneity, and thus of an opportunity for natural selection. However, variability provides evidence of heterogeneity only if it exceeds the level of variability to be expected in a cohort of identical individuals all experiencing the same vital rates. Such comparisons require a way to calculate the statistics of lifetime reproduction from demographic data. Here, a new approach is presented, using the theory of Markov chains with rewards, obtaining all the moments of the distribution of lifetime reproduction. The approach applies to age- or stage-classified models, to constant, periodic, or stochastic environments, and to any kind of reproductive schedule. As examples, I analyze data from six empirical studies, of a variety of animal and plant taxa (nematodes, polychaetes, humans, and several species of perennial plants). PMID:21738586

  3. Hypoxia Treatment of Callosobruchus maculatus Females and Its Effects on Reproductive Output and Development of Progeny Following Exposure.

    PubMed

    Yan, Yan; Williams, Scott B; Baributsa, Dieudonne; Murdock, Larry L

    2016-01-01

    Modified atmospheres present a residue-free alternative to fumigants for controlling postharvest pests of grain during storage. How sub-lethal applications of this method affects the reproductive fitness of target pests, however, is still not fully understood. We examined how low levels of ambient oxygen influence the reproduction of the female cowpea bruchid (Callosobruchus maculatus), a pest of cowpea. We used three low-oxygen atmospheres-2%, 5% and 10% (v/v) oxygen-and observed their effects on: (1) the number of eggs laid by bruchids compared to insects held in normoxic (~20% oxygen) conditions; (2) the total number of eggs laid; and (3) the number of progeny that reached maturity. Low oxygen did not significantly affect the number of eggs laid during 48 or 72 h of exposure, but 2% and 5% oxygen did negatively affected total egg production. Increasing the exposure time from 48 to 72 h further depressed lifetime reproductive output. Maternal and egg exposure to hypoxia reduced the number of progeny that reached adulthood. Lower adult emergence was observed from eggs laid under low oxygen and longer exposure times. These data demonstrate that hermetic conditions depress the egg-laying behavior of cowpea bruchids and the successful development of their progeny. PMID:27322332

  4. Hypoxia Treatment of Callosobruchus maculatus Females and Its Effects on Reproductive Output and Development of Progeny Following Exposure

    PubMed Central

    Yan, Yan; Williams, Scott B.; Baributsa, Dieudonne; Murdock, Larry L.

    2016-01-01

    Modified atmospheres present a residue-free alternative to fumigants for controlling postharvest pests of grain during storage. How sub-lethal applications of this method affects the reproductive fitness of target pests, however, is still not fully understood. We examined how low levels of ambient oxygen influence the reproduction of the female cowpea bruchid (Callosobruchus maculatus), a pest of cowpea. We used three low-oxygen atmospheres—2%, 5% and 10% (v/v) oxygen—and observed their effects on: (1) the number of eggs laid by bruchids compared to insects held in normoxic (~20% oxygen) conditions; (2) the total number of eggs laid; and (3) the number of progeny that reached maturity. Low oxygen did not significantly affect the number of eggs laid during 48 or 72 h of exposure, but 2% and 5% oxygen did negatively affected total egg production. Increasing the exposure time from 48 to 72 h further depressed lifetime reproductive output. Maternal and egg exposure to hypoxia reduced the number of progeny that reached adulthood. Lower adult emergence was observed from eggs laid under low oxygen and longer exposure times. These data demonstrate that hermetic conditions depress the egg-laying behavior of cowpea bruchids and the successful development of their progeny. PMID:27322332

  5. Long-term data on reproductive output and longevity in captive female common marmosets (Callithrix jacchus).

    PubMed

    Ash, Hayley; Buchanan-Smith, Hannah M

    2014-11-01

    The common marmoset (Callithrix jacchus) is widely used in biomedical research, with many housed for breeding purposes world-wide. Significant variation in reproductive output among females has been found compared to other anthropoid primates. The present study explores this reproductive variation, focusing on potential predictors of dam longevity and litter size, as well as changes over time. Back-record analysis was conducted, yielding litter information and reproductive summaries of 360 dams housed at three UK marmoset colonies over four decades (1970s-2000s). Results revealed differences among the colonies, as well as within colonies over decades, suggesting environment may play an important role. Cox proportional hazards regression analyses revealed significant effects of mean litter size and yearly production on dam longevity. Decade, mean inter-birth interval and mean dam weight were found to be significant factors explaining dam longevity when looking at colonies individually. The most commonly recorded cause of death was "poor condition." Linear regression models found that no reproductive variable was useful in explaining mean litter size, except dam weight at conception, data which was only consistently recorded at one colony. While triplets were common at all three colonies, these larger litters were consistently associated with higher infant mortality, despite human intervention to improve survival. This study increases our understanding of marmoset reproduction, and possible improvements to practical aspects of colony management to enhance survival and welfare are discussed. PMID:24809989

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

    PubMed

    Yagound, Boris; Blacher, Pierre; Chameron, Stéphane; Châline, Nicolas

    2012-01-01

    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 of worker

  7. Effects of parasite pressure on parasite mortality and reproductive output in a rodent-flea system: inferring host defense trade-offs.

    PubMed

    Warburton, Elizabeth M; Kam, Michael; Bar-Shira, Enav; Friedman, Aharon; Khokhlova, Irina S; Koren, Lee; Asfur, Mustafa; Geffen, Eli; Kiefer, Daniel; Krasnov, Boris R; Degen, A Allan

    2016-09-01

    Evaluating host resistance via parasite fitness helps place host-parasite relationships within evolutionary and ecological contexts; however, few studies consider both these processes simultaneously. We investigated how different levels of parasite pressure affect parasite mortality and reproductive success in relationship to host defense efforts, using the rodent Gerbillus nanus and the flea Xenopsylla conformis as a host-parasite system. Fifteen immune-naïve male rodents were infested with 20, 50, or 100 fleas for four weeks. During this time number of new imagoes produced per adult flea (our flea reproductive output metric), flea mortality, and change in circulating anti-flea immunoglobulin G (our measure of adaptive immune defense) were monitored. Three hypotheses guided this work: (1) increasing parasite pressure would heighten host defenses; (2) parasite mortality would increase and parasite reproductive output would decrease with increasing investment in host defense; and (3) hosts under high parasite pressure could invest in behavioral and/or immune responses. We predicted that at high infestation levels (a) parasite mortality would increase; (b) flea reproductive output per individual would decrease; and (c) host circulating anti-flea antibody levels would increase. The hypotheses were partially supported. Flea mortality significantly increased and flea reproductive output significantly decreased as flea pressure increased. Host adaptive immune defense did not significantly change with increasing flea pressure. Therefore, we inferred that investment in host behavioral defense, either alone or in combination with density-dependent effects, may be more efficient at increasing flea mortality and decreasing flea reproductive output than antibody production during initial infestation in this system. PMID:27130319

  8. Combining Site Occupancy, Breeding Population Sizes and Reproductive Success to Calculate Time-Averaged Reproductive Output of Different Habitat Types: An Application to Tricolored Blackbirds

    PubMed Central

    Holyoak, Marcel; Meese, Robert J.; Graves, Emily E.

    2014-01-01

    In metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern. The Tricolored Blackbird (Agelaius tricolor) has experienced large population declines, is the most colonial songbird in North America, is largely confined to California, and breeds itinerantly in multiple habitat types. It has had chronically low reproductive success in recent years. Although young produced per nest have previously been compared across habitats, no study has simultaneously considered site occupancy and reproductive success. Combining occupancy, abundance, frequency of occurrence, reproductive success and nest failure rate we found that that large colonies in grain fields fail frequently because of nest destruction due to harvest prior to fledging. Consequently, net time-averaged reproductive output is low compared to colonies in non-native Himalayan blackberry or thistles, and native stinging nettles. Cattail marshes have intermediate reproductive output, but their reproductive output might be improved by active management. Harvest of grain-field colonies necessitates either promoting delay of harvest or creating alternative, more secure nesting habitats. Stinging nettle and marsh colonies offer the main potential sources for restoration or native habitat creation. From 2005–2011 breeding site occupancy declined 3x faster than new breeding colonies were formed, indicating a rapid decline in occupancy. Total abundance showed a similar decline. Causes of variation in the value for reproduction of nesting substrates and factors behind continuing population declines merit urgent investigation. The method

  9. Combining site occupancy, breeding population sizes and reproductive success to calculate time-averaged reproductive output of different habitat types: an application to Tricolored Blackbirds.

    PubMed

    Holyoak, Marcel; Meese, Robert J; Graves, Emily E

    2014-01-01

    In metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern. The Tricolored Blackbird (Agelaius tricolor) has experienced large population declines, is the most colonial songbird in North America, is largely confined to California, and breeds itinerantly in multiple habitat types. It has had chronically low reproductive success in recent years. Although young produced per nest have previously been compared across habitats, no study has simultaneously considered site occupancy and reproductive success. Combining occupancy, abundance, frequency of occurrence, reproductive success and nest failure rate we found that that large colonies in grain fields fail frequently because of nest destruction due to harvest prior to fledging. Consequently, net time-averaged reproductive output is low compared to colonies in non-native Himalayan blackberry or thistles, and native stinging nettles. Cattail marshes have intermediate reproductive output, but their reproductive output might be improved by active management. Harvest of grain-field colonies necessitates either promoting delay of harvest or creating alternative, more secure nesting habitats. Stinging nettle and marsh colonies offer the main potential sources for restoration or native habitat creation. From 2005-2011 breeding site occupancy declined 3x faster than new breeding colonies were formed, indicating a rapid decline in occupancy. Total abundance showed a similar decline. Causes of variation in the value for reproduction of nesting substrates and factors behind continuing population declines merit urgent investigation. The method we

  10. The synthetic progestin megestrol acetate adversely affects zebrafish reproduction.

    PubMed

    Han, Jian; Wang, Qiangwei; Wang, Xianfeng; Li, Yonggang; Wen, Sheng; Liu, Shan; Ying, Guangguo; Guo, Yongyong; Zhou, Bingsheng

    2014-05-01

    Synthetic progestins contaminate the aquatic ecosystem, and may cause adverse health effects on aquatic organisms. Megestrol acetate (MTA) is present in the aquatic environment, but its possible effects on fish reproduction are unknown. In the present study, we investigated the endocrine disruption and impact of MTA on fish reproduction. After a pre-exposure period of 14 days, reproductively mature zebrafish (Danio rerio) (F0) were exposed to MTA at environmental concentrations (33, 100, 333, and 666 ng/L) for 21 days. Egg production was decreased in F0 fish exposed to MTA, with a significant decrease at 666 ng/L. The exposure significantly decreased the circulating concentrations of estradiol (E2) and testosterone (T) in female fish or 11-keto testosterone (11-KT) in male fish. MTA exposure significantly downregulated the transcription of certain genes along the hypothalamic-pituitary-gonadal (HPG) axis. MTA did not affect early embryonic development or hatching success in the F1 generation. The present study showed that MTA is a potent endocrine disruptor in fish, and short-term exposure to MTA could significantly affect reproduction in fish and negatively impact the fish population. PMID:24647012

  11. Does Gender Affect a Scientist's Research Output in Evolutionary Ecology?

    NASA Astrophysics Data System (ADS)

    Bonnet, Xavier; Shine, Richard; Lourdais, Olivier

    To examine how an author's gender influences his or her research output, the authors analyzed (not simply scored) more than 900 published articles in nine leading scientific journals in the field of evolutionary ecology. Women were strongly underrepresented in all countries, but this bias is decreasing. Men and women differed significantly in their fields of research, with women preferentially conducting projects on behavior rather than evolution or ecology. Most aspects of the structure of published articles and the level of conceptual generality were unaffected by an author's gender. Because discriminatory practices by reviewers and editors can be manifested in attributes of the articles that survive the review process, the latter result suggests a lack of gender-based discrimination during the review process. Gender differences in research output presumably reflect a complex array of genetic and social influences; a clearer understanding of these causal factors may help identify (and thus reduce) gender-based discrimination.

  12. Reproductive interference between Rana dalmatina and Rana temporaria affects reproductive success in natural populations.

    PubMed

    Hettyey, Attila; Vági, Balázs; Kovács, Tibor; Ujszegi, János; Katona, Patrik; Szederkényi, Márk; Pearman, Peter B; Griggio, Matteo; Hoi, Herbert

    2014-10-01

    Experimental evidence suggests that reproductive interference between heterospecifics can seriously affect individual fitness; support from field studies for such an effect has, however, remained scarce. We studied reproductive interference in 25 natural breeding ponds in an area where two ranid frogs, Rana dalmatina and Rana temporaria, co-occur. The breeding seasons of the two species usually overlap and males of both species are often found in amplexus with heterospecific females, even though matings between heterospecifics produce no viable offspring. We estimated species abundance ratios based on the number of clutches laid and evaluated fertilization success. In ponds with low spatial complexity and a species abundance ratio biased towards R. temporaria, the average fertilization success of R. dalmatina eggs decreased, while this relationship was not detectable in spatially more complex ponds. Fertilization success of R. temporaria did not decrease with increasing relative numbers of heterospecifics. This asymmetry in fitness effects of reproductive interference may be attributed to R. temporaria males being more competitive in scramble competition for females than R. dalmatina males. Our study is among the first to demonstrate that in natural breeding populations of vertebrates interference among heterospecifics has the potential to substantially lower reproductive success at the population level, which may in turn affect population dynamics. PMID:25138258

  13. Female gonadal hormones and reproductive behaviors as key determinants of successful reproductive output of breeding whooping cranes (Grus americana)

    USGS Publications Warehouse

    Brown, Megan E; Converse, Sarah J.; Chandler, Jane N.; Shafer, Charles; Brown, Janine L; Keefer, Carol L; Songsasen, Nucharin

    2016-01-01

    Reproductive success of endangered whooping cranes (Grus americana) maintained ex situ is poor. As part of an effort to identify potential causes of poor reproductive success in a captive colony, we used non-invasive endocrine monitoring to assess gonadal and adrenal steroids of bird pairs with various reproductive outcomes and evaluated the relationships of hormones and behaviors to reproductive performance. Overall, reproductively successful (i.e., egg laying) females had significantly higher mean estrogen levels but lower mean progestogen concentrations than did unsuccessful females. Other hormones, including glucocorticoids and androgens, were not significantly different between successful and unsuccessful individuals. Observations of specific behaviors such as unison calling, marching, and the number of copulation attempts, along with overall time spent performing reproductive behaviors, were significantly higher in successful pairs. Our findings indicate that overall reproductive performance of whooping crane pairs is linked to female gonadal hormone excretion and reproductive behaviors, but not to altered adrenal hormone production.

  14. Female gonadal hormones and reproductive behaviors as key determinants of successful reproductive output of breeding whooping cranes (Grus americana).

    PubMed

    Brown, Megan E; Converse, Sarah J; Chandler, Jane N; Shafer, Charles; Brown, Janine L; Keefer, Carol L; Songsasen, Nucharin

    2016-05-01

    Reproductive success of endangered whooping cranes (Grus americana) maintained ex situ is poor. As part of an effort to identify potential causes of poor reproductive success in a captive colony, we used non-invasive endocrine monitoring to assess gonadal and adrenal steroids of bird pairs with various reproductive outcomes and evaluated the relationships of hormones and behaviors to reproductive performance. Overall, reproductively successful (i.e., egg laying) females had significantly higher mean estrogen levels but lower mean progestogen concentrations than did unsuccessful females. Other hormones, including glucocorticoids and androgens, were not significantly different between successful and unsuccessful individuals. Observations of specific behaviors such as unison calling, marching, and the number of copulation attempts, along with overall time spent performing reproductive behaviors, were significantly higher in successful pairs. Our findings indicate that overall reproductive performance of whooping crane pairs is linked to female gonadal hormone excretion and reproductive behaviors, but not to altered adrenal hormone production. PMID:27080552

  15. Gravid Spot Predicts Developmental Progress and Reproductive Output in a Livebearing Fish, Gambusia holbrooki

    PubMed Central

    Norazmi-Lokman, Nor Hakim; Purser, G. J.; Patil, Jawahar G.

    2016-01-01

    In most livebearing fish, the gravid spot is an excellent marker to identify brooding females, however its use to predict progress of embryonic development, brood size, timing of parturition and overall reproductive potential of populations remain unexplored. Therefore, to understand these relationships, this study quantified visual attributes (intensity and size) of the gravid spot in relation to key internal development in Gambusia holbrooki. Observations show that the colour of the gravid spot arises from progressive melanisation on the surface of the ovarian sac at its hind margin, rather than melanisation of the developing embryos or the skin of the brooding mother. More importantly, the gravid spot intensity and size were closely linked with both developmental stages and clutch size, suggesting their reliable use as external surrogates of key internal developmental in the species. Using predictive consistency of the gravid spot, we also determined the effect of rearing temperature (23°C and 25°C) on gestation period and parturition behaviour. The results show that gestation period was significantly reduced (F = 364.58; df = 1,48; P˃0.05) at 25°C. However there was no significant difference in average number of fry parturated in the two temperature groups (P<0.05), reaffirming that gravid spot intensity is a reliable predictor of reproductive output. The parturition in the species occurred predominantly in the morning and in contrast to earlier reports, tails of the fry emerged first with a few exceptions of head-first, twin and premature births. This study demonstrates utility of the gravid spot for downstream reproductive investigations in a live-bearing fish both in the field and laboratory. The reproducibility of the relationships (intensity with both developmental stage and clutch size), imply that they are also relevant to wild populations that experience varying temperature climes and stressors, significant deviations of which may serve as

  16. Gravid Spot Predicts Developmental Progress and Reproductive Output in a Livebearing Fish, Gambusia holbrooki.

    PubMed

    Norazmi-Lokman, Nor Hakim; Purser, G J; Patil, Jawahar G

    2016-01-01

    In most livebearing fish, the gravid spot is an excellent marker to identify brooding females, however its use to predict progress of embryonic development, brood size, timing of parturition and overall reproductive potential of populations remain unexplored. Therefore, to understand these relationships, this study quantified visual attributes (intensity and size) of the gravid spot in relation to key internal development in Gambusia holbrooki. Observations show that the colour of the gravid spot arises from progressive melanisation on the surface of the ovarian sac at its hind margin, rather than melanisation of the developing embryos or the skin of the brooding mother. More importantly, the gravid spot intensity and size were closely linked with both developmental stages and clutch size, suggesting their reliable use as external surrogates of key internal developmental in the species. Using predictive consistency of the gravid spot, we also determined the effect of rearing temperature (23 °C and 25 °C) on gestation period and parturition behaviour. The results show that gestation period was significantly reduced (F = 364.58; df = 1,48; P ˃ 0.05) at 25 °C. However there was no significant difference in average number of fry parturated in the two temperature groups (P<0.05), reaffirming that gravid spot intensity is a reliable predictor of reproductive output. The parturition in the species occurred predominantly in the morning and in contrast to earlier reports, tails of the fry emerged first with a few exceptions of head-first, twin and premature births. This study demonstrates utility of the gravid spot for downstream reproductive investigations in a live-bearing fish both in the field and laboratory. The reproducibility of the relationships (intensity with both developmental stage and clutch size), imply that they are also relevant to wild populations that experience varying temperature climes and stressors, significant deviations of which may serve as

  17. A longitudinal study of age-specific reproductive output and body condition among male rhesus macaques, Macaca mulatta.

    PubMed

    Bercovitch, Fred B; Widdig, Anja; Trefilov, Andrea; Kessler, Matt J; Berard, John D; Schmidtke, Jörg; Nürnberg, Peter; Krawczak, Michael

    2003-07-01

    In many mammalian species, male reproductive success appears to climb sharply at young adulthood, form a brief plateau during prime ages, and decline among older animals, a pattern often attributed to reduced physical condition with ageing. However, solid evidence to either substantiate or refute this profile among nonhuman primates is lacking. Here, we combine a decade of genetic analysis of paternity among free-ranging rhesus macaques, Macaca mulatta, with information about body condition in order to evaluate how changes in morphology might govern age-specific reproduction among males. We show that age-specific reproductive success traverses the same life history profile as found in other mammals, but reductions in reproductive output with advanced age were associated with reduced chances of survivorship rather than accompanied by diminished body condition. We demonstrate that variance in male age at onset of reproduction is three times greater than variance in female age at onset of reproduction. We provide the first evidence from primates that age-specific reproductive output among males is not a consequence of age-related changes in body condition, but reflects social and demographic factors. PMID:12883773

  18. Listening to music affects diurnal variation in muscle power output.

    PubMed

    Chtourou, H; Chaouachi, A; Hammouda, O; Chamari, K; Souissi, N

    2012-01-01

    The purpose of this investigation was to assess the effects of listening to music while warming-up on the diurnal variations of power output during the Wingate test. 12 physical education students underwent four Wingate tests at 07:00 and 17:00 h, after 10 min of warm-up with and without listening to music. The warm-up consisted of 10 min of pedalling at a constant pace of 60 rpm against a light load of 1 kg. During the Wingate test, peak and mean power were measured. The main finding was that peak and mean power improved from morning to afternoon after no music warm-up (p<0.001 and p<0.01, respectively). These diurnal variations disappeared for mean power and persisted with an attenuated morning-evening difference (p<0.05) for peak power after music warm-up. Moreover, peak and mean power were significantly higher after music than no music warm-up during the two times of testing. Thus, as it is a legal method and an additional aid, music should be used during warm-up before performing activities requiring powerful lower limbs' muscles contractions, especially in the morning competitive events. PMID:22134883

  19. Age, sex and reproductive status affect boldness in dogs.

    PubMed

    Starling, Melissa J; Branson, Nicholas; Thomson, Peter C; McGreevy, Paul D

    2013-09-01

    Boldness in dogs is believed to be one end of the shy-bold axis, representing a super-trait. Several personality traits fall under the influence of this super-trait. Previous studies have found that boldness is affected by breed and breed groups, influences performance in sporting dogs, and is affected in some cases by the sex of the dogs. This study investigated the effects of dog age, sex and reproductive status on boldness in dogs by way of a dog personality survey circulated amongst Australian dog owners. Age had a significant effect on boldness (F=4.476; DF=16,758; P<0.001), with boldness decreasing with age in years. Males were bolder than females (F=19.219; DF=1,758; P<0.001) and entire dogs were bolder than neutered dogs (F=4.330; DF=1,758; P<0.038). The study indicates how behaviour may change in adult dogs as they age and adds to the literature on how sex and reproductive status may affect personality in dogs. PMID:23778256

  20. Efficiency of pollination and satiation of predators determine reproductive output in Iberian Juniperus thurifera woodlands.

    PubMed

    Mezquida, E T; Rodríguez-García, E; Olano, J M

    2016-01-01

    Fruit production in animal-dispersed plants has a strong influence on fitness because large crops increase the number of seeds dispersed by frugivores. Large crops are costly, and environmental control of plant resources is likely play a role in shaping temporal and spatial variations in seed production, particularly in fluctuating environments such as the Mediterranean. The number of fruits that start to develop and the proportion of viable seeds produced are also linked to the number of flowers formed and the efficiency of pollination in wind-pollinated plants. Finally, large fruit displays also attract seed predators, having a negative effect on seed output. We assessed the relative impact of environmental conditions on fruit production, and their combined effect on seed production, abortion and seed loss through three predispersal predators in Juniperus thurifera L., sampling 14 populations across the Iberian Peninsula. Wetter than average conditions during flowering and early fruit development led to larger crop sizes; this effect was amplified at tree level, with the most productive trees during more favourable years yielding fruits with more viable seeds and less empty and aborted seeds. In addition, large crops satiated the less mobile seed predator. The other two predispersal predators responded to plant traits, the presence of other seed predators and environmental conditions, but did not show a satiation response to the current-year crop. Our large-scale study on a dioecious, wind-pollinated Mediterranean juniper indicates that pollination efficiency and satiation of seed predators, mediated by environmental conditions, are important determinants of reproductive output in this juniper species. PMID:25892115

  1. Personality Traits in Rhesus Macaques (Macaca mulatta) Are Heritable but Do Not Predict Reproductive Output

    PubMed Central

    Brent, Lauren J. N.; Semple, Stuart; MacLarnon, Ann; Ruiz-Lambides, Angelina; Gonzalez-Martinez, Janis; Platt, Michael L.

    2013-01-01

    There is growing evidence that behavioral tendencies, or “personalities,” in animals are an important aspect of their biology, yet their evolutionary basis is poorly understood. Specifically, how individual variation in personality arises and is subsequently maintained by selection remains unclear. To address this gap, studies of personality require explicit incorporation of genetic information. Here, we explored the genetic basis of personality in rhesus macaques by determining the heritability of personality components and by examining the fitness consequences of those components. We collected observational data for 108 adult females living in three social groups in a free-ranging population via focal animal sampling. We applied principal component analysis to nine spontaneously occurring behaviors and identified six putative personality components, which we named Meek, Bold, Aggressive, Passive, Loner, and Nervous. All components were repeatable and heritable, with heritability estimates ranging from 0.14 to 0.35. We found no evidence of an association with reproductive output, measured either by infant survival or by interbirth interval, for any of the personality components. This finding suggests either that personality does not have fitness-related consequences in this population or that selection has acted to reduce fitness-associated variation in personality. PMID:24659840

  2. DEHP Impairs Zebrafish Reproduction by Affecting Critical Factors in Oogenesis

    PubMed Central

    Carnevali, Oliana; Tosti, Luca; Speciale, Claudia; Peng, Chun; Zhu, Yong; Maradonna, Francesca

    2010-01-01

    Public concerns on phthalates distributions in the environment have been increasing since they can cause liver cancer, structural abnormalities and reduce sperm counts in male reproductive system. However, few data are actually available on the effects of Di-(2-ethylhexyl)-phthalate (DEHP) in female reproductive system. The aim of this study was to assess the impacts of DEHP on zebrafish oogenesis and embryo production. Female Danio rerio were exposed to environmentally relevant doses of DEHP and a significant decrease in ovulation and embryo production was observed. The effects of DEHP on several key regulators of oocyte maturation and ovulation including bone morphogenetic protein-15 (BMP15), luteinizing hormone receptor (LHR), membrane progesterone receptors (mPRs) and cyclooxygenase (COX)-2 (ptgs2) were determined by real time PCR. The expressions of BMP15 and mPR proteins were further determined by Western analyses to strengthen molecular findings. Moreover, plasma vitellogenin (vtg) titers were assayed by an ELISA procedure to determine the estrogenic effects of DEHP and its effects on oocyte growth. A significant reduction of fecundity in fish exposed to DEHP was observed. The reduced reproductive capacity was associated with an increase in ovarian BMP15 levels. This rise, in turn, was concomitant with a significant reduction in LHR and mPRβ levels. Finally, ptgs2 expression, the final trigger of ovulation, was also decreased by DEHP. By an in vitro maturation assay, the inhibitory effect of DEHP on germinal vesicle breakdown was further confirmed. In conclusion, DEHP affecting signals involved in oocyte growth (vtg), maturation (BMP15, LHR, mPRs,) and ovulation (ptgs2), deeply impairs ovarian functions with serious consequences on embryo production. Since there is a significant genetic similarity between D.rerio and humans, the harmful effects observed at oocyte level may be relevant for further molecular studies on humans. PMID:20419165

  3. You are what you eat: food limitation affects reproductive fitness in a sexually cannibalistic praying mantid.

    PubMed

    Barry, Katherine L

    2013-01-01

    Resource limitation during the juvenile stages frequently results in developmental delays and reduced size at maturity, and dietary restriction during adulthood can affect longevity and reproductive output. Variation in food intake can also result in alteration to the normal pattern of resource allocation among body parts or life-history stages. My primary aim in this study was to determine how varying juvenile and/or adult feeding regimes affect particular female and male traits in the sexually cannibalistic praying mantid Pseudomantis albofimbriata. Praying mantids are sit-and-wait predators whose resource intake can vary dramatically depending on environmental conditions within and across seasons, making them useful for studying the effects of feeding regime on various facets of reproductive fitness. In this study, there was a significant trend/difference in development and morphology for males and females as a result of juvenile feeding treatment, however, its effect on the fitness components measured for males was much greater than on those measured for females. Food-limited males were less likely to find a female during field enclosure experiments and smaller males were slower at finding a female in field-based experiments, providing some of the first empirical evidence of a large male size advantage for scrambling males. Only adult food limitation affected female fecundity, and the ability of a female to chemically attract males was also most notably affected by adult feeding regime (although juvenile food limitation did play a role). Furthermore, the significant difference/trend in all male traits and the lack of difference in male trait ratios between treatments suggests a proportional distribution of resources and, therefore, no trait conservation by food-limited males. This study provides evidence that males and females are under different selective pressures with respect to resource acquisition and is also one of very few to show an effect of juvenile

  4. You Are What You Eat: Food Limitation Affects Reproductive Fitness in a Sexually Cannibalistic Praying Mantid

    PubMed Central

    Barry, Katherine L.

    2013-01-01

    Resource limitation during the juvenile stages frequently results in developmental delays and reduced size at maturity, and dietary restriction during adulthood can affect longevity and reproductive output. Variation in food intake can also result in alteration to the normal pattern of resource allocation among body parts or life-history stages. My primary aim in this study was to determine how varying juvenile and/or adult feeding regimes affect particular female and male traits in the sexually cannibalistic praying mantid Pseudomantis albofimbriata. Praying mantids are sit-and-wait predators whose resource intake can vary dramatically depending on environmental conditions within and across seasons, making them useful for studying the effects of feeding regime on various facets of reproductive fitness. In this study, there was a significant trend/difference in development and morphology for males and females as a result of juvenile feeding treatment, however, its effect on the fitness components measured for males was much greater than on those measured for females. Food-limited males were less likely to find a female during field enclosure experiments and smaller males were slower at finding a female in field-based experiments, providing some of the first empirical evidence of a large male size advantage for scrambling males. Only adult food limitation affected female fecundity, and the ability of a female to chemically attract males was also most notably affected by adult feeding regime (although juvenile food limitation did play a role). Furthermore, the significant difference/trend in all male traits and the lack of difference in male trait ratios between treatments suggests a proportional distribution of resources and, therefore, no trait conservation by food-limited males. This study provides evidence that males and females are under different selective pressures with respect to resource acquisition and is also one of very few to show an effect of juvenile

  5. Is there a missing link? Effects of root herbivory on plant-pollinator interactions and reproductive output in a monocarpic species.

    PubMed

    Ghyselen, C; Bonte, D; Brys, R

    2016-01-01

    Herbivores can have a major influence on plant fitness. The direct impact of herbivory on plant reproductive output has long been studied, and recently also indirect effects of herbivory on plant traits and pollinator attraction have received increasing attention. However, the link between these direct and indirect effects has seldom been studied. In this study, we investigated effects of root herbivory on plant and floral traits, pollination success and reproductive outcome in the monocarpic perennial Cynoglossum officinale. We exposed 119 C. officinale plants to a range of root herbivore damage by its specialist herbivore Mogulones cruciger. We assessed the effect of herbivory on several plant traits, pollinator foraging behaviour and reproductive output, and to elucidate the link between these last two we also quantified pollen deposition and pollen tube growth and applied a pollination experiment to test whether seed set was pollen-limited. Larval root herbivory induced significant changes in plant traits and had a negative impact on pollinator visitation. Infested plants were reduced in size, had fewer flowers and received fewer pollinator visits at plant and flower level than non-infested plants. Also, seed set was negatively affected by root herbivory, but this could not be attributed to pollen limitation since neither stigmatic pollen loads and pollen tube growth nor the results of the hand-pollination experiment differed between infested and non-infested plants. Our observations demonstrate that although herbivory may induce significant changes in flowering behaviour and resulting plant-pollinator interactions, it does not necessarily translate into higher rates of pollen limitation. The observed reductions in reproductive output following infection can mainly be attributed to higher resource limitation compared to non-infested plants. PMID:25731922

  6. Long-term impacts of poaching on relatedness, stress physiology, and reproductive output of adult female african elephants.

    PubMed

    Gobush, K S; Mutayoba, B M; Wasser, S K

    2008-12-01

    Widespread poaching prior to the 1989 ivory ban greatly altered the demographic structure of matrilineal African elephant (Loxodonta africana) family groups in many populations by decreasing the number of old, adult females. We assessed the long-term impacts of poaching by investigating genetic, physiological, and reproductive correlates of a disturbed social structure resulting from heavy poaching of an African elephant population in Mikumi National Park, Tanzania, prior to 1989. We examined fecal glucocorticoid levels and reproductive output among 218 adult female elephants from 109 groups differing in size, age structure, and average genetic relatedness over 25 months from 2003 to 2005. The distribution in group size has changed little since 1989, but the number of families with tusked old matriarchs has increased by 14.2%. Females from groups that lacked an old matriarch, first-order adult relatives, and strong social bonds had significantly higher fecal glucocorticoid values than those from groups with these features (all females R(2)= 0.31; females in multiadult groups R(2)= 0.46). Females that frequented isolated areas with historically high poaching risk had higher fecal glucocorticoid values than those in low poaching risk areas. Females with weak bonds and low group relatedness had significantly lower reproductive output (R(2)[U]=0.21). Females from disrupted groups, defined as having observed average group relatedness 1 SD below the expected mean for a simulated unpoached family, had significantly lower reproductive output than females from intact groups, despite many being in their reproductive prime. These results suggest that long-term negative impacts from poaching of old, related matriarchs have persisted among adult female elephants 1.5 decades after the 1989 ivory ban was implemented. PMID:18759771

  7. Demographic History and Reproductive Output Correlates with Intraspecific Genetic Variation in Seven Species of Indo-Pacific Mangrove Crabs.

    PubMed

    Fratini, Sara; Ragionieri, Lapo; Cannicci, Stefano

    2016-01-01

    The spatial distribution and the amount of intraspecific genetic variation of marine organisms are strongly influenced by many biotic and abiotic factors. Comparing biological and genetic data characterizing species living in the same habitat can help to elucidate the processes driving these variation patterns. Here, we present a comparative multispecies population genetic study on seven mangrove crabs co-occurring in the West Indian Ocean characterized by planktotrophic larvae with similar pelagic larval duration. Our main aim was to investigate whether a suite of biological, behavioural and ecological traits could affect genetic diversities of the study species in combination with historical demographic parameters. As possible current explanatory factors, we used the intertidal micro-habitat colonised by adult populations, various parameters of individual and population fecundity, and the timing of larval release. As the genetic marker, we used partial sequences of cytochrome oxidase subunit I gene. Genetic and ecological data were collected by the authors and/or gathered from primary literature. Permutational multiple regression models and ANOVA tests showed that species density and their reproductive output in combination with historical demographic parameters could explain the intraspecific genetic variation indexes across the seven species. In particular, species producing consistently less eggs per spawning event showed higher values of haplotype diversity. Moreover, Tajima's D parameters well explained the recorded values for haplotype diversity and average γst. We concluded that current intraspecific gene diversities in crabs inhabiting mangrove forests were affected by population fecundity as well as past demographic history. The results were also discussed in terms of management and conservation of fauna in the Western Indian Ocean mangroves. PMID:27379532

  8. Demographic History and Reproductive Output Correlates with Intraspecific Genetic Variation in Seven Species of Indo-Pacific Mangrove Crabs

    PubMed Central

    Fratini, Sara; Ragionieri, Lapo; Cannicci, Stefano

    2016-01-01

    The spatial distribution and the amount of intraspecific genetic variation of marine organisms are strongly influenced by many biotic and abiotic factors. Comparing biological and genetic data characterizing species living in the same habitat can help to elucidate the processes driving these variation patterns. Here, we present a comparative multispecies population genetic study on seven mangrove crabs co-occurring in the West Indian Ocean characterized by planktotrophic larvae with similar pelagic larval duration. Our main aim was to investigate whether a suite of biological, behavioural and ecological traits could affect genetic diversities of the study species in combination with historical demographic parameters. As possible current explanatory factors, we used the intertidal micro-habitat colonised by adult populations, various parameters of individual and population fecundity, and the timing of larval release. As the genetic marker, we used partial sequences of cytochrome oxidase subunit I gene. Genetic and ecological data were collected by the authors and/or gathered from primary literature. Permutational multiple regression models and ANOVA tests showed that species density and their reproductive output in combination with historical demographic parameters could explain the intraspecific genetic variation indexes across the seven species. In particular, species producing consistently less eggs per spawning event showed higher values of haplotype diversity. Moreover, Tajima’s D parameters well explained the recorded values for haplotype diversity and average γst. We concluded that current intraspecific gene diversities in crabs inhabiting mangrove forests were affected by population fecundity as well as past demographic history. The results were also discussed in terms of management and conservation of fauna in the Western Indian Ocean mangroves. PMID:27379532

  9. Does garbage in the diet improve reproductive output of Glaucous Gulls

    USGS Publications Warehouse

    Weiser, E.L.; Powell, A.N.

    2010-01-01

    Anthropogenic subsidies are used by a variety of predators in areas developed for human use or residence. If subsidies promote population growth, these predators can have a negative effect on local prey species. The Glaucous Gull (Larus hyperboreus) is an abundant predator in northern Alaska that is believed to benefit from garbage as a supplemental food source, but this supposition has never been tested. In summer 2008 and 2009, we recorded the Glaucous Gull's diet and reproduction at 10 breeding colonies in northern Alaska. Colonies were in industrial, residential, and undeveloped areas and ranged from 5 to 75 km from the nearest landfill. By colony, garbage occurred in zero to 85% of pellets and food remains produced during the chick-rearing period, and the average number of chicks fledged per pair ranged from zero to 2.9. Random-forest analysis indicated that percent occurrence of garbage in the diet was the second most important factor (after number of eggs per pair) explaining variance in fledging rate. There was a significant positive correlation between percent occurrence of garbage in the diet and fledging rate in each year. If this correlation reflects a causal relationship, it suggests that human development that increases gulls' access to garbage could result in increased local gull populations. Such an increase could affect the gulls' natural prey species, including at least 14 species of shorebirds and waterfowl of conservation concern. ?? The Cooper Ornithological Society 2010.

  10. Dietary pollutants induce oxidative stress, altering maternal antioxidant provisioning and reproductive output in the temperate sea urchin Evechinus chloroticus.

    PubMed

    Lister, Kathryn N; Lamare, Miles D; Burritt, David J

    2016-08-01

    Evidence is growing to suggest that the capacity to withstand oxidative stress may play an important role in shaping life-history trade-offs, although little is known on the relationship in broadcast spawning marine invertebrates. In this group, variation in gamete quantity and quality are important drivers of offspring survival and successful recruitment. Therefore the provisioning of eggs with antioxidants may be an important driver of life history strategies because they play a critical role in preventing damage from reactive oxygen species to macromolecules. In this study, a suite of oxidative stress biomarkers was measured in the gonads and eggs of the sea urchin Evechinus chloroticus exposed to polycyclic aromatic hydrocarbons (PAHs). Links between oxidative stress markers and core components of fitness including fecundity, gamete quality and maternal transfer of antioxidants were assessed. Experimental induction of oxidative stress was achieved via exposure to a mix of four PAHs over a 21-day period. In PAH exposed individuals, we observed a significant upregulation of the antioxidant defence and detoxification enzymes SOD, CAT, GR, GPx and GST, as well as a greater pool of the non-enzymatic antioxidant glutathione in gonad tissue and eggs. In contrast, glutathione redox status was not affected by PAH exposure, with the percentage of reduced glutathione remaining at approximately 80% in both gonad tissue and released eggs. PAH-exposed adults experienced greater than three- and five-fold increases in oxidative protein and lipid damage, respectively, in gonad tissue. In contrast, eggs maintained low levels of damage, not differing from baseline levels found in eggs released from PAH-naïve mothers. PAH exposure also resulted in a 2-fold reduction in fecundity of reproductively mature females but no significant alteration to egg diameter. Although PAH-exposed females released fewer eggs, successful fertilisation of those eggs was slightly enhanced with average

  11. Size-assortative mating and effect of maternal body size on the reproductive output of the nassariid Buccinanops globulosus

    NASA Astrophysics Data System (ADS)

    Avaca, María Soledad; Narvarte, Maite; Martín, Pablo

    2012-04-01

    Size- assortative mating is usually present in populations where there is a positive relationship between female size and reproductive output. In this study, we tested for the presence of sexual size dimorphism, size-assortative mating and the effects of female size on reproductive output in a wild population of Buccinanops globulosus, an endemic nassariid of the Southwestern Atlantic Ocean with direct development. The results showed that: 1) females were larger than males, indicating sexual size dimorphism; 2) mate sizes were significantly correlated, indicating a component of size-assortative mating; 3) males of medium and large size classes were paired with larger females than small-sized males; 4) larger females were paired with large males; 5) maternal body size was positively related to some proxies of reproductive success (number of nurse eggs per egg capsule, egg capsular area and total length at hatching). Our results suggest that larger females may be favored as mates over smaller ones owing to their higher investment per offspring and consequently a larger initial juvenile size as juvenile.

  12. Promoting Reproductive Options for HIV-Affected Couples in Sub-Saharan Africa

    PubMed Central

    Mmeje, Okeoma; Cohen, Craig R.; Murage, Alfred; Ong’ech, John; Kiarie, James; van der Poel, Sheryl

    2014-01-01

    HIV-affected couples have unique challenges that require access to information and reproductive services which prevent HIV transmission to the uninfected partner and offspring while allowing couples to fulfill their reproductive goals. In high HIV prevalent regions of sub-Saharan Africa, HIV-affected couples require multipurpose prevention technologies (MPTs) to enhance their reproductive healthcare options beyond contraception and prevention of HIV/sexually transmitted infections (STIs) to include assistance in childbearing. The unique characteristics of the condom and its accepted use in conjunction with safer conception interventions allow HIV-serodiscordant couples an opportunity to maintain reproductive health, prevent HIV/STI transmission, and achieve their reproductive goals while timing conception. Rethinking the traditional view of the condom and incorporating a broader reproductive health perspective of HIV-affected couples into MPT methodologies will impact demand, acceptability, and uptake of these future technologies. PMID:25335844

  13. Tracking Official Development Assistance for Reproductive Health in Conflict-Affected Countries

    PubMed Central

    Patel, Preeti; Roberts, Bayard; Guy, Samantha; Lee-Jones, Louise; Conteh, Lesong

    2009-01-01

    Background Reproductive health needs are particularly acute in countries affected by armed conflict. Reliable information on aid investment for reproductive health in these countries is essential for improving the efficiency and effectiveness of aid. The purpose of this study was to analyse official development assistance (ODA) for reproductive health activities in conflict-affected countries from 2003 to 2006. Methods and Findings The Creditor Reporting System and the Financial Tracking System databases were the chosen data sources for the study. ODA disbursement for reproductive health activities to 18 conflict-affected countries was analysed for 2003, 2004, 2005, and 2006. An average of US$20.8 billion in total ODA was disbursed annually to the 18 conflict-affected countries between 2003 and 2006, of which US$509.3 million (2.4%) was allocated to reproductive health. This represents an annual average of US$1.30 disbursed per capita in the 18 sampled countries for reproductive health activities. Non-conflict-affected least-developed countries received 53.3% more ODA for reproductive health activities than conflict-affected least-developed countries, despite the latter generally having greater reproductive health needs. ODA disbursed for HIV/AIDS prevention and treatment increased by 119.4% from 2003 to 2006. The ODA disbursed for other direct reproductive health activities declined by 35.9% over the same period. Conclusions This study provides evidence of inequity in disbursement of reproductive health ODA between conflict-affected countries and non-conflict-affected countries, and between different reproductive health activities. These findings and the study's recommendations seek to support initiatives to make aid financing more responsive to need in the context of armed conflict. PMID:19513098

  14. Postdoctoral researchers in the UK: a snapshot at factors affecting their research output.

    PubMed

    Felisberti, Fatima M; Sear, Rebecca

    2014-01-01

    Postdoctoral training is a typical step in the course of an academic career, but very little is known about postdoctoral researchers (PDRs) working in the UK. This study used an online survey to explore, for the first time, relevant environmental factors which may be linked to the research output of PDRs in terms of the number of peer-reviewed articles per year of PDR employment. The findings showed reliable links between the research output and research institutions, time spent as PDR, and parental education, whereas no clear links were observed between PDRs' output and research area, nationality, gender, number of siblings, or work environment. PDRs based in universities tended to publish, on average, more than the ones based in research centres. PDRs with children tended to stay longer in postdoctoral employment than PDRs without children. Moreover, research output tended to be higher in PDRs with fathers educated at secondary or higher level. The work environment did not affect output directly, but about 1/5 of PDRs were not satisfied with their job or institutional support and about 2/3 of them perceived their job prospects as "difficult". The results from this exploratory study raise important questions, which need to be addressed in large-scale studies in order to understand (and monitor) how PDRs' family and work environment interact with their research output-an essential step given the crucial role of PDRs in research and development in the country. PMID:24705885

  15. Legal issues affecting confidentiality and informed consent in reproductive health.

    PubMed

    Rockett, L R

    2000-01-01

    The law governing confidentiality and informed consent has acquired unique characteristics in the area of reproductive health, as a consequence of both the establishment of a constitutional right to privacy in reproductive health matters and the reaction of those politically and morally opposed to the exercise of that right. The primary issues have involved: 1) the right of minors to receive reproductive health services without parental consent, which remains a political battleground; 2) laws requiring physicians to provide information to pregnant patients that is intended, not to inform them of the risks and benefits of the procedure, but to discourage them from obtaining abortions; 3) coerced and prohibited sterilizations; 4) court-ordered contraception and procedures to protect the fetus; and 5) restrictions on counseling about abortion, contraception, sterilization, and other reproductive health services authorized by state conscience or noncompliance clauses that shield such restrictions from the usual ethical, medical, and legal rules governing informed consent. The last area is of profound significance to the ability of women to make informed decisions about their reproductive health options. In the current economic environment, which fuels mergers and acquisitions involving sectarian and nonsectarian institutions, women are increasingly being put at risk as a result of such restrictions. PMID:11070641

  16. Allopregnanolone as a Mediator of Affective Switching in Reproductive Mood Disorders

    PubMed Central

    Schiller, Crystal Edler; Schmidt, Peter J.; Rubinow, David R.

    2014-01-01

    Rationale Reproductive mood disorders, including premenstrual dysphoria (PMD) and postpartum depression (PPD), are characterized by affective dysregulation that occurs during specific reproductive states. The occurrence of illness onset during changes in reproductive endocrine function has generated interest in the role of gonadal steroids in the pathophysiology of reproductive mood disorders, yet the mechanisms by which the changing hormone milieu triggers depression in susceptible women remain poorly understood. Objectives This review focuses on one of the neurosteroid metabolites of progesterone – allopregnanolone (ALLO) – that acutely regulates neuronal function and may mediate affective dysregulation that occurs concomitant with changes in reproductive endocrine function. We describe the role of the ‘neuroactive’ steroids estradiol and progesterone in reproductive endocrine-related mood disorders to highlight the potential mechanisms by which ALLO might contribute to their pathophysiology. Finally, using existing data, we test the hypothesis that changes in ALLO levels may trigger affective dysregulation in susceptible women. Results Although there is no reliable evidence that basal ALLO levels distinguish those with PMD or PPD from those without, existing animal models suggest potential mechanisms by which specific reproductive states may unmask susceptibility to affective dysregulation. Consistent with these models, initially euthymic women with PMD and those with a history of PPD show a negative association between depressive symptoms and circulating ALLO levels following progesterone administration. Conclusions Existing animal models and our own preliminary data suggest that ALLO may play an important role in the pathophysiology of reproductive mood disorders by triggering affective dysregulation in susceptible women. PMID:24846476

  17. Life history and the competitive environment: trajectories of growth, maturation, and reproductive output among chacma baboons.

    PubMed

    Johnson, Sara E

    2003-01-01

    The social environment is a key feature influencing primate life histories. Chacma baboons (Papio hamadryas ursinus) are a female-bonded species with a strict linear dominance hierarchy. In this species, the allocation of energy to competing demands of growth and reproduction is hypothesized to vary as a function of competitive ability, which in turn increases with social rank. Since growth rate is a major component of life history models, measures of age-specific growth were used to analyze variation in life history traits across social ranks. Weights of 42 immature baboons were obtained without sedation or baiting from a troop of well-habituated chacma baboons in the Okavango Delta, Botswana. Using demographic and weight data from this wild population, five main findings emerged: 1) Weight for age and growth rate of infant and juvenile females are positively associated with maternal rank. 2) Male growth is not influenced by maternal rank. 3) Female growth shows smaller variation across feeding conditions than male growth. 4) Low-ranking adult females continue investment in offspring through prolonged lactation until they reach a weight comparable to that of high-ranking infants. 5) The benefit of rank to reproductive success shown in this study is 0.83 additional offspring. Reproductive span determined predominantly by age at maturation contributes 27-38% to the difference in expected number of offspring by rank, vs. 62-73% due to reproductive rate. These findings have major implications for understanding the role of social environment in phenotypic plasticity of life history traits, and in the evolution of primate life histories. PMID:12489139

  18. Species-specific trends in the reproductive output of corals across environmental gradients and bleaching histories.

    PubMed

    Howells, Emily J; Ketchum, Remi N; Bauman, Andrew G; Mustafa, Yasmine; Watkins, Kristina D; Burt, John A

    2016-04-30

    Coral populations in the Persian Gulf have a reputation for being some of the toughest in the world yet little is known about the energetic constraints of living under temperature and salinity extremes. Energy allocation for sexual reproduction in Gulf corals was evaluated relative to conspecifics living under milder environmental conditions in the Oman Sea. Fecundity was depressed at Gulf sites in two Indo-Pacific merulinid species (Cyphastrea microphthalma and Platygyra daedalea) but not in a regionally endemic acroporid (Acropora downingi). Gulf populations of each species experienced high temperature bleaching at the onset of gametogenesis in the study but fecundity was only negatively impacted in P. daedalea and A. downingi. Large population sizes of C. microphthalma and P. daedalea in the Gulf are expected to buffer reductions on colony-level fecundity. However, depleted population sizes of A. downingi at some Gulf sites equate to low reef-wide fecundity and likely impede outcrossing success. PMID:26608503

  19. Oyster reproduction is affected by exposure to polystyrene microplastics.

    PubMed

    Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goïc, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-Pont, Ika; Soudant, Philippe; Huvet, Arnaud

    2016-03-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L(-1)) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS over the 2-µm-diameter particles. Consumption of microalgae and absorption efficiency were significantly higher in exposed oysters, suggesting compensatory and physical effects on both digestive parameters. After 2 mo, exposed oysters had significant decreases in oocyte number (-38%), diameter (-5%), and sperm velocity (-23%). The D-larval yield and larval development of offspring derived from exposed parents decreased by 41% and 18%, respectively, compared with control offspring. Dynamic energy budget modeling, supported by transcriptomic profiles, suggested a significant shift of energy allocation from reproduction to structural growth, and elevated maintenance costs in exposed oysters, which is thought to be caused by interference with energy uptake. Molecular signatures of endocrine disruption were also revealed, but no endocrine disruptors were found in the biological samples. This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring. PMID:26831072

  20. Oyster reproduction is affected by exposure to polystyrene microplastics

    PubMed Central

    Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goïc, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-Pont, Ika; Soudant, Philippe; Huvet, Arnaud

    2016-01-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L−1) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS over the 2-µm-diameter particles. Consumption of microalgae and absorption efficiency were significantly higher in exposed oysters, suggesting compensatory and physical effects on both digestive parameters. After 2 mo, exposed oysters had significant decreases in oocyte number (−38%), diameter (−5%), and sperm velocity (−23%). The D-larval yield and larval development of offspring derived from exposed parents decreased by 41% and 18%, respectively, compared with control offspring. Dynamic energy budget modeling, supported by transcriptomic profiles, suggested a significant shift of energy allocation from reproduction to structural growth, and elevated maintenance costs in exposed oysters, which is thought to be caused by interference with energy uptake. Molecular signatures of endocrine disruption were also revealed, but no endocrine disruptors were found in the biological samples. This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring. PMID:26831072

  1. Prey selectivity affects reproductive success of a corallivorous reef fish.

    PubMed

    Brooker, Rohan M; Jones, Geoffrey P; Munday, Philip L

    2013-06-01

    Most animals consume a narrower range of food resources than is potentially available in the environment, but the underlying basis for these preferences is often poorly understood. Foraging theory predicts that prey selection should represent a trade-off between prey preferences based on nutritional value and prey availability. That is, species should consume preferred prey when available, but select less preferred prey when preferred prey is rare. We employed both field observation and laboratory experiments to examine the relationship between prey selection and preferences in the obligate coral-feeding filefish, Oxymonacanthus longirostris. To determine the drivers of prey selection, we experimentally established prey preferences in choice arenas and tested the consequences of prey preferences for key fitness-related parameters. Field studies showed that individuals fed almost exclusively on live corals from the genus Acropora. While diet was dominated by the most abundant species, Acropora nobilis, fish appeared to preferentially select rarer acroporids, such as A. millepora and A. hyacinthus. Prey choice experiments confirmed strong preferences for these corals, suggesting that field consumption is constrained by availability. In a longer-term feeding experiment, reproductive pairs fed on non-preferred corals exhibited dramatic reductions to body weight, and in hepatic and gonad condition, compared with those fed preferred corals. The majority of pairs fed preferred corals spawned frequently, while no spawning was observed for any pairs fed a non-preferred species of coral. These experiments suggest that fish distinguish between available corals based on their intrinsic value as prey, that reproductive success is dependent on the presence of particular coral species, and that differential loss of preferred corals could have serious consequences for the population success of these dietary specialists. PMID:23124333

  2. Thought waves remotely affect the performance (output voltage) of photoelectric cells

    NASA Astrophysics Data System (ADS)

    Cao, Dayong; Cao, Daqing

    2012-02-01

    In our experiments, thought waves have been shown to be capable of changing (affecting) the output voltage of photovoltaic cells located from as far away as 1-3 meters. There are no wires between brain and photoelectric cell and so it is presumed only the thought waves act on the photoelectric cell. In continual rotations, the experiments tested different solar cells, measuring devices and lamps, and the experiments were done in different labs. The first experiment was conducted on Oct 2002. Tests are ongoing. Conclusions and assumptions include: 1) the slow thought wave has the energy of space-time as defined by C1.00007: The mass, energy, space and time systemic theory- MEST. Every process releases a field effect electrical vibration which be transmitted and focussed in particular paths; 2) the thought wave has the information of the order of tester; 3) the brain (with the physical system of MEST) and consciousness (with the spirit system of the mind, consciousness, emotion and desire-MECD) can produce the information (a part of them as the Genetic code); 4) through some algorithms such as ACO Ant Colony Optimization and EA Evolutionary Algorithm (or genetic algorithm) working in RAM, human can optimize the information. This Optimizational function is the intelligence; 5) In our experiments, not only can thought waves affect the voltage of the output photoelectric signals by its energy, but they can also selectively increase or decrease those photoelectric currents through remote consciousness interface and a conscious-brain information technology.

  3. Clonal Patch Size and Ramet Position of Leymus chinensis Affected Reproductive Allocation

    PubMed Central

    Zhang, Zhuo; Yang, Yunfei

    2015-01-01

    Reproductive allocation is critically important for population maintenance and usually varies with not only environmental factors but also biotic ones. As a typical rhizome clonal plant in China's northern grasslands, Leymus chinensis usually dominates the steppe communities and grows in clonal patches. In order to clarify the sexual reproductive allocation of L. chinensis in the process of the growth and expansion, we selected L. chinensis clonal patches of a range of sizes to examine the reproductive allocation and allometric growth of the plants. Moreover, the effects of position of L. chinensis ramets within the patch on their reproductive allocation were also examined. Clonal patch size and position both significantly affected spike biomass, reproductive tiller biomass and SPIKE/TILLER biomass ratio. From the central to the marginal zone, both the spike biomass and reproductive tiller biomass displayed an increasing trend in all the five patch size categories except for reproductive tiller biomass in 15–40m2 category. L. chinensis had significantly larger SPIKE/TILLER biomass ratio in marginal zone than in central zone of clonal patches that are larger than 15 m2 in area. Regression analysis showed that the spike biomass and SPIKE/TILLER biomass ratio were negatively correlated with clonal patch size while patch size showed significantly positive effect on SEED/SPIKE biomass ratio, but the reproductive tiller biomass and SEED/TILLER biomass ratio were not dependent on clonal patch size. The relationships between biomass of spike and reproductive tiller, between mature seed biomass and spike biomass and between mature seed biomass and reproductive tiller biomass were significant allometric for all or some of patch size categories, respectively. The slopes of all these allometric relationships were significantly different from 1. The allometric growth of L. chinensis is patch size-dependent. This finding will be helpful for developing appropriate practices for

  4. The reproduction in women affected by cooley disease

    PubMed Central

    Pafumi, Carlo; Leanza, Vito; Coco, Luana; Vizzini, Stefania; Ciotta, Lilliana; Messina, Alessandra; Leanza, Gianluca; Zarbo, Giuseppe; D'Agati, Alfio; Palumbo, Marco Antonio; Iemmola, Alessandra; Gulino, Ferdinando Antonio; Teodoro, Maria Cristina; Attard, Matthew; Plesca, Alina Cristina; Soares, Catarina; Kouloubis, Nina; Chammas, Mayada

    2011-01-01

    The health background management and outcomes of 5 pregnancies in 4 women affected by Cooley Disease, from Paediatric Institute of Catania University, are described, considering the preconceptual guidances and cares for such patients. These patients were selected among a group of 100 thalassemic women divided into three subgroups, according to their first and successive menstruation characteristics: i) patients with primitive amenorrhoea, ii) patients with secondary amenorrhoea and iii) patients with normal menstruation. Only one woman, affected by primitive amenorrhoea, needed the induction of ovulation. A precise and detailed pre-pregnancy assessment was effected before each conception. This was constituted by a series of essays, including checks for diabetes and hypothyroidism, for B and C hepatitis and for blood group antibodies. Moreover were evaluated: cardiac function, rubella immunity and transaminases. Other pregnancy monitoring, and cares during labour and delivery were effected according to usual obstetrics practice. All the women were in labour when she were 38 week pregnant, and the outcome were five healthy babies born at term, weighting between 2600 and 3200gs. The only complication was the Caesarean section. The improvements of current treatments, especially in the management of iron deposits, the prolongation of survival rate, will result in a continuous increase of pregnancies in thalassemic women. Pregnancy is now a real possibility for women affected by such disease. We are furthermore studying the possibility to collect the fetus' umbilical cord blood, after the delivery, to attempt eterologus transplantation to his mother trying to get a complete marrow reconstitution. PMID:22184526

  5. How female education affects reproductive behavior in urban Pakistan.

    PubMed

    Sathar, Z A; Mason, K O

    1993-01-01

    Although Pakistan remains in a pretransitional stage (contraceptive prevalence of only 11.9% among married women in 1992), urban women with post-primary levels of education are spearheading the gradual move toward fertility transition. Data collected in the city of Karachi in 1987 were used to determine whether the inverse association between fertility and female education is attributable to child supply variables, demand factors, or fertility regulation costs. Karachi, with its high concentration of women with secondary educations employed in professional occupations, has a contraceptive prevalence rate of 31%. Among women married for less than 20 years, a 10-year increment in education predicts that a woman will average two-fifths of a child less than other women in the previous 5 years. Regression analysis identified 4 significant intervening variables in the education-fertility relationship: marriage duration, net family income, formal sector employment, and age at first marriage. Education appears to affect fertility because it promotes a later age at marriage and thus reduces life-time exposure to the risk of childbearing, induces women to marry men with higher incomes (a phenomenon that either reduces the cost of fertility regulation or the demand for children), leads women to become employed in the formal sector (leading to a reduction in the demand for children), and has other unspecified effects on women's values or opportunities that are captured by their birth cohort. When these intervening variables are held constant, women's attitude toward family planning loses its impact on fertility, as do women's domestic autonomy and their expectations of self-support in old age. These findings lend support to increased investments in female education in urban Pakistan as a means of limiting the childbearing of married women. Although it is not clear if investment in female education would have the same effect in rural Pakistan, such action is important from a

  6. Ozone affects gas exchange, growth and reproductive development in Brassica campestris (Wisconsin fast plants).

    PubMed

    Black, V J; Stewart, C A; Roberts, J A; Black, C R

    2007-01-01

    Exposure to ozone (O(3)) may affect vegetative and reproductive development, although the consequences for yield depend on the effectiveness of the compensatory processes induced. This study examined the impact on reproductive development of exposing Brassica campestris (Wisconsin Fast Plants) to ozone during vegetative growth. Plants were exposed to 70 ppb ozone for 2 d during late vegetative growth or 10 d spanning most of the vegetative phase. Effects on gas exchange, vegetative growth, reproductive development and seed yield were determined. Impacts on gas exchange and foliar injury were related to pre-exposure stomatal conductance. Exposure for 2 d had no effect on growth or reproductive characteristics, whereas 10-d exposure reduced vegetative growth and reproductive site number on the terminal raceme. Mature seed number and weight per pod and per plant were unaffected because seed abortion was reduced. The observation that mature seed yield per plant was unaffected by exposure during the vegetative phase, despite adverse effects on physiological, vegetative and reproductive processes, shows that indeterminate species such as B. campestris possess sufficient compensatory flexibility to avoid reductions in seed production. PMID:17803646

  7. [A sociological study of factors affecting reproductive health of female teenagers and young women].

    PubMed

    Nizamov, I G; Chechulina, O V

    2003-01-01

    The reproductive health of teenagers deserves a special attention and must be regarded from the viewpoint of their future prospects as well as their social and cultural media. The mentioned social-and-cultural factors affecting the teenagers' attitude towards sexuality and preconditioning their access to information and services of healthcare have an impact on the status of their reproductive health and on their general well-being, including the ability of teenagers to avoid an undesired pregnancy or sexually transmitted diseases. PMID:12882120

  8. Limits to sustained energy intake. XVIII. Energy intake and reproductive output during lactation in Swiss mice raising small litters.

    PubMed

    Zhao, Zhi-Jun; Song, De-Guang; Su, Zhen-Cheng; Wei, Wen-Bo; Liu, Xian-Bin; Speakman, John R

    2013-06-15

    Limits to sustained energy intake (SusEI) during lactation in Swiss mice have been suggested to reflect the secretory capacity of the mammary glands. However, an alternative explanation is that milk production and food intake are regulated to match the limited growth capacity of the offspring. In the present study, female Swiss mice were experimentally manipulated in two ways - litter sizes were adjusted to be between 1 and 9 pups and mice were exposed to either warm (21°C) or cold (5°C) conditions from day 10 of lactation. Energy intake, number of pups and litter mass, milk energy output (MEO), thermogenesis, mass of the mammary glands and brown adipose tissue cytochrome c oxidase activity of the mothers were measured. At 21 and 5°C, pup mass at weaning was almost independent of litter size. Positive correlations were observed between the number of pups, litter mass, asymptotic food intake and MEO. These data were consistent with the suggestion that in small litters, pup requirements may be the major factor limiting milk production. Pups raised at 5°C had significantly lower body masses than those raised at 21°C. This was despite the fact that milk production and energy intake at the same litter sizes were both substantially higher in females raising pups at 5°C. This suggests that pup growth capacity is lower in the cold, perhaps due to pups allocating ingested energy to fuel thermogenesis. Differences in observed levels of milk production under different conditions may then reflect a complex interplay between factors limiting maternal performance (peripheral limitation and heat dissipation: generally better when it is cooler) and factors influencing maximum pup growth (litter size and temperature: generally better when it is hotter), and may together result in an optimal temperature favouring reproduction. PMID:23720804

  9. The disadvantages of mating outside home: How breeding in captivity affects the reproductive success of seahorses?

    NASA Astrophysics Data System (ADS)

    Faleiro, Filipa; Narciso, Luís

    2013-04-01

    In captivity, husbandry conditions are distinct from those experienced by fish in the wild and may have a significant effect on reproductive success. This study evaluates the effect of supportive breeding (i.e., breeding animals in captivity using wild parents) on some quantitative and qualitative aspects of the reproductive success of the long-snouted seahorse, Hippocampus guttulatus. Wild and captive broods were compared in terms of juvenile number, size, condition and fatty acid profile at birth. Reproductive investment and breeding success of H. guttulatus decreased considerably in captivity. Juveniles from captive broods were fewer in number, smaller, generally thinner and with lower fatty acid contents (per juvenile) than those from wild broods, although their fatty acid composition (μg mg- 1 DW or %TFA) was not significantly affected. Although not greatly encouraging, the poor reproductive performance of captive seahorses should not, however, efface the potential of supportive breeding as a tool for seahorse conservation. Enhanced conditions and long-term breeding in captivity will allow to improve the reproductive success of the species and the quality of the fingerlings.

  10. The sex lives of ctenophores: the influence of light, body size, and self-fertilization on the reproductive output of the sea walnut, Mnemiopsis leidyi

    PubMed Central

    Sasson, Daniel A.

    2016-01-01

    Ctenophores (comb jellies) are emerging as important animals for investigating fundamental questions across numerous branches of biology (e.g., evodevo, neuroscience and biogeography). A few ctenophore species including, most notably, Mnemiopsis leidyi, are considered as invasive species, adding to the significance of studying ctenophore ecology. Despite the growing interest in ctenophore biology, relatively little is known about their reproduction. Like most ctenophores, M. leidyi is a simultaneous hermaphrodite capable of self-fertilization. In this study, we assess the influence of light on spawning, the effect of body size on spawning likelihood and reproductive output, and the cost of self-fertilization on egg viability in M. leidyi. Our results suggest that M. leidyi spawning is more strongly influenced by circadian rhythms than specific light cues and that body size significantly impacts spawning and reproductive output. Mnemiopsis leidyi adults that spawned alone produced a lower percentage of viable embryos versus those that spawned in pairs, suggesting that self-fertilization may be costly in this species. These results provide insight into the reproductive ecology of M. leidyi and provide a fundamental resource for researchers working with them in the laboratory. PMID:27042395

  11. Prepubertal tamoxifen treatment affects development of heifer reproductive tissues and related signaling pathways.

    PubMed

    Al Naib, A; Tucker, H L M; Xie, G; Keisler, D H; Bartol, F F; Rhoads, R P; Akers, R M; Rhoads, M L

    2016-07-01

    Prepubertal exposure of the developing ovaries and reproductive tract (RT) to estrogen or xenoestrogens can have acute and long-term consequences that compromise the reproductive performance of cattle. This research examined effects of the selective estrogen receptor modulator tamoxifen (TAM) on gene and protein abundance in prepubertal ovaries and RT, with a particular focus on signaling pathways that affect morphology. Tamoxifen was administered to Holstein heifer calves (n=8) daily (0.3mg/kg subcutaneously) from 28 to 120 d of age, when tissues were collected. Control calves (n=7) received an equal volume of excipient. Weight, gross measurements, and samples of reproductive tissues were collected, and protein and mRNA were extracted from snap-frozen samples of vagina, cervix, uterus, oviduct, ovary, and liver. Neither estradiol nor insulin-like growth factor I (IGFI) concentrations in the serum were affected by TAM treatment. Tamoxifen treatment reduced ovarian weight independently from effects on antral follicle populations, as there was no difference in visible antral follicle numbers on the day of collection. Estrogen receptor α (ESR1) and β (ESR2) mRNA, ESR1 protein, IGFI, progesterone receptor, total growth hormone receptor, WNT4, WNT5A, and WNT7A mRNA, in addition to mitogen-activated protein kinase (MAPK) and phosphorylated MAPK proteins were affected differently depending on the tissue examined. However, neither IGFI receptor mRNA nor protein abundance were affected by TAM treatment. Results indicate that reproductive development in prepubertal Holstein heifer calves is TAM-sensitive, and that bovine RT and ovarian development are supported, in part, by estrogen receptor-dependent mechanisms during the period studied here. Potential long-term consequences of such developmental disruption remain to be defined. PMID:27085397

  12. Genotypic variation in host response to infection affects parasite reproductive rate.

    PubMed

    Tavalire, Hannah F; Blouin, Michael S; Steinauer, Michelle L

    2016-02-01

    Parasite fitness is largely influenced by a variation in host response due to the host's genetic background. Here we investigated the impact of host genotype on pathogen success in the snail vector of its castrating parasite, Schistosoma mansoni. We infected five inbred lines of Biomphalaria glabrata with two infection doses and followed their growth, reproductive output and parasite production throughout the course of infection. There was no difference in resistance to infection among inbred lines, but lines varied in their responses to infection and the numbers of parasites produced. Snails did not compensate for castration by increasing their fecundity during the early phase of infection (fecundity compensation). However, some lines were able to delay parasite shedding for up to 30 weeks, thus prolonging reproduction before the onset of castration. Here we propose this strategy as a novel defense against castrating pathogens in snails. Gigantism, a predicted outcome of castration due to energy reallocation, occurred early in infection (<15 weeks) and was not universal among the snail lines. Lines that did not show gigantism were also characterised by a high parasite production rate and low survivorship, perhaps indicating energy reallocation into parasite production and costly immune defense. We observed no differences in total parasite production among lines throughout the entire course of infection, although lines differed in their parasite reproductive rate. The average rate of parasite production varied among lines from 1300 to 2450 cercariae within a single 2h shedding period, resulting in a total production of 6981-29,509 cercariae over the lifetime of a single snail. Regardless of genetic background, snail size was a strong predictor of parasite reproduction: each millimetre increase in snail size at the time of the first shed resulted in up to 3500 more cercariae over the lifetime of the snail. The results of this study provide a detailed picture of

  13. Depressing Antidepressant: Fluoxetine Affects Serotonin Neurons Causing Adverse Reproductive Responses in Daphnia magna.

    PubMed

    Campos, Bruno; Rivetti, Claudia; Kress, Timm; Barata, Carlos; Dircksen, Heinrich

    2016-06-01

    Selective serotonin reuptake inhibitors (SSRIs) are widely used antidepressants. As endocrine disruptive contaminants in the environment, SSRIs affect reproduction in aquatic organisms. In the water flea Daphnia magna, SSRIs increase offspring production in a food ration-dependent manner. At limiting food conditions, females exposed to SSRIs produce more but smaller offspring, which is a maladaptive life-history strategy. We asked whether increased serotonin levels in newly identified serotonin-neurons in the Daphnia brain mediate these effects. We provide strong evidence that exogenous SSRI fluoxetine selectively increases serotonin-immunoreactivity in identified brain neurons under limiting food conditions thereby leading to maladaptive offspring production. Fluoxetine increases serotonin-immunoreactivity at low food conditions to similar maximal levels as observed under high food conditions and concomitantly enhances offspring production. Sublethal amounts of the neurotoxin 5,7-dihydroxytryptamine known to specifically ablate serotonin-neurons markedly decrease serotonin-immunoreactivity and offspring production, strongly supporting the effect to be serotonin-specific by reversing the reproductive phenotype attained under fluoxetine. Thus, SSRIs impair serotonin-regulation of reproductive investment in a planktonic key organism causing inappropriately increased reproduction with potentially severe ecological impact. PMID:27128505

  14. Hippocampal morphology is differentially affected by reproductive experience in the mother.

    PubMed

    Pawluski, Jodi L; Galea, Liisa A M

    2006-01-01

    Pregnancy and mothering result in a number of hormonal, neurological, and behavioral changes that are necessary to ensure reproductive success. With subsequent reproductive experience (multiparity and mothering), further neurological and behavioral changes may result. Recent research has shown that previous motherhood enhances both hippocampus-dependent learning and memory and long-term potentiation (LTP); together with decreases in hippocampus volumes during pregnancy it is suggested that the hippocampus is affected by pregnancy and/or mothering. The present experiment aimed to investigate the effect of reproductive experience (nulli, primi-, and multiparity and mothering) on dendritic morphology in the CA1 and CA3 regions of the hippocampus. Brains were stained with a modified version of the single-section Golgi impregnation technique, and dendritic length, number of branch points, and spine density was analyzed for apical and basal regions of CA1 and CA3 pyramidal neurons. Primiparity and/or mothering resulted in dendritic remodeling in both the CA1 and CA3 hippocampal regions, and multiparity resulted in enhanced spine density in the basal CA1 region, which was positively correlated with number of male pups in a litter. These findings point to the effect of reproductive experience and offspring on plasticity in the hippocampus, an area not traditionally associated with motherhood. PMID:16216005

  15. Chronic stress in pregnant guinea pigs (Cavia aperea f. porcellus) attenuates long-term stress hormone levels and body weight gain, but not reproductive output.

    PubMed

    Schöpper, Hanna; Palme, Rupert; Ruf, Thomas; Huber, Susanne

    2011-12-01

    Stress, when extreme or chronic, can have a negative impact on health and survival of mammals. This is especially true for females during reproduction when self-maintenance and investment in offspring simultaneously challenge energy turnover. Therefore, we investigated the effects of repeated stress during early- and mid-gestation on the maternal stress axis, body weight gain and reproductive output. Female guinea pigs (Cavia aperea f. porcellus, n = 14) were either stressed (treatment: exposure to strobe light in an unfamiliar environment on gestational day -7, 0, 7, 14, 21, 28, 35, 42) or left completely undisturbed (control) throughout pregnancy. Females of both groups received the same respective diets, and reproductive parameters were evaluated upon parturition. Additionally, hormonal data were obtained from blood and feces. The stress exposure induced a significant increase in plasma cortisol concentrations during the afternoon. In contrast to this short-term response in plasma cortisol concentrations, we found no significant differences in the levels of cortisol metabolites in feces collected after stress exposure between groups and even significantly decreased levels of fecal cortisol metabolites on non-stress days over time in treatment females. Among treatment females, gain in body weight was attenuated over gestation and body weight was lower compared to control females during lactation, especially in cases of large litter sizes. No differences could be seen in the reproductive parameters. We conclude that repeated stress exposure with strobe light during early- and mid-gestation results in a down-regulation of the hypothalamic-pituitary-adrenal axis and lower weight gain in treatment females, but has no effect on reproductive output. PMID:21647601

  16. Caterpillar biomass depends on temperature and precipitation, but does not affect bird reproduction

    NASA Astrophysics Data System (ADS)

    Schöll, Eva Maria; Ohm, Judith; Hoffmann, Konstantin Frank; Hille, Sabine Marlene

    2016-07-01

    Complex changes in phenological events appear as temperatures are increasing: In deciduous forests bud burst, hatching of herbivorous caterpillars, egg laying and nestling time of birds when feeding chicks on caterpillars, may differentially shift into early season and alter synchronization. If timing of bird reproduction has to match with short periods of food availability, phenological mismatch could negatively affect reproductive success. Using a unique empirical approach along an altitudinal temperature gradient, we firstly asked whether besides temperature, also precipitation and leaf phenology interplay and affect caterpillar biomass, since impacts of rainfall on caterpillars have been largely neglected so far. Secondly, we asked whether abundance of caterpillars and thereby body mass of great tit nestlings, which are mainly fed with caterpillars, vary along the altitudinal temperature gradient. We demonstrated that next to temperature also precipitation and leaf phenology affected caterpillar biomass. In our beech forest, even along altitudes, caterpillars were available throughout the great tit breeding season but in highly variable amounts. Our findings revealed that although timing of leaf phenology and great tit breeding season were delayed with decreasing temperature, caterpillars occurred synchronously and were not delayed according to altitude. However, altitude negatively affected caterpillar biomass, but body mass of fledglings at high altitude sites was not affected by lower amounts of caterpillar biomass. This might be partially outweighed by larger territory sizes in great tits.

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

    PubMed Central

    Frenck, Georg; van der Linden, Leon; Mikkelsen, Teis Nørgaard; Brix, Hans; Jørgensen, Rikke Bagger

    2013-01-01

    Functional plant traits are likely to adapt under the sustained pressure imposed by environmental changes through natural selection. Employing Brassica napus as a model, a multi-generational study was performed to investigate the potential trajectories of selection at elevated [CO2] in two different temperature regimes. To reveal phenotypic divergence at the manipulated [CO2] and temperature conditions, a full-factorial natural selection regime was established in a phytotron environment over the range of four generations. It is demonstrated that a directional response to selection at elevated [CO2] led to higher quantities of reproductive output over the range of investigated generations independent of the applied temperature regime. The increase in seed yield caused an increase in aboveground biomass. This suggests quantitative changes in the functions of carbon sequestration of plants subjected to increased levels of CO2 over the generational range investigated. The results of this study suggest that phenotypic divergence of plants selected under elevated atmospheric CO2 concentration may drive the future functions of plant productivity to be different from projections that do not incorporate selection responses of plants. This study accentuates the importance of phenotypic responses across multiple generations in relation to our understanding of biogeochemical dynamics of future ecosystems. Furthermore, the positive selection response of reproductive output under increased [CO2] may ameliorate depressions in plant reproductive fitness caused by higher temperatures in situations where both factors co-occur. PMID:23762504

  18. Does the inclusion of protease inhibitors in the insemination extender affect rabbit reproductive performance?

    PubMed

    Casares-Crespo, L; Vicente, J S; Talaván, A M; Viudes-de-Castro, M P

    2016-03-15

    The bioavailability of buserelin acetate when added to the seminal dose appears to be determined by the activity of the existing aminopeptidases. Thus, the addition of aminopeptidase inhibitors to rabbit semen extenders could be a solution to decrease the hormone degradation. This study was conducted to evaluate the effect of the protease activity inhibition on rabbit semen quality parameters and reproductive performance after artificial insemination. Seminal quality was not affected by the incubation with protease inhibitors, being the values of motility, viability, and acrosome integrity not significantly different between the protease inhibitors and the control group. In addition, seminal plasma aminopeptidase activity was inhibited in a 55.1% by the protease inhibitors. On the other hand, regarding the effect of protease inhibitors on reproductive performance, our results showed that the presence of protease inhibitors affected the prolificacy rate (9.2 ± 0.26 and 9.3 ± 0.23 vs. 8.2 ± 0.22 total born per litter for negative control, positive control, and aminopeptidase inhibitors group, respectively; P < 0.05), having this group one kit less per delivery. We conclude that the addition of a wide variety of protease inhibitors in the rabbit semen extender negatively affects prolificacy rate. Therefore, the development of new extenders with specific aminopeptidase inhibitors would be one of the strategies to increase the bioavailability of GnRH analogues without affecting the litter size. PMID:26639641

  19. Reproductive allocation and output in herbaceous annuals of the genera Polygonum, Ipomoea, and Cassia in elevated CO[sub 2] environments

    SciTech Connect

    Farnsworth, E.J.; Bazzaz, F.A. )

    1994-06-01

    In assessing the capacity of plants to adapt to rapidly changing global climate, we must elucidate the impacts of elevated carbon dioxide on reproduction, fitness and evolution. We investigated how elevated CO[sub 2] influenced reproduction and growth of plants exhibiting a range of floral displays, the implications of shifts in allocation for fitness in these species, and whether related taxa would show similar patterns of response. Three herbaceous, annual species each of the genera Polygonum, Ipomoea, and Cassia were grown under 350 or 700 ppm CO[sub 2]. Vegetative growth and reproductive output were non-destructively measured throughout the full life span, and biomass calibrated with a subsample harvest at first flowering. Viability and germination studies of seed progeny were conducted to more precisely characterize fitness. Timecourse and numbers of floral buds, flowers, unripe and abscised fruits differed between CO[sub 2] treatments. Genera differed significantly in their phenological responses to elevated CO[sub 2], Polygonum and Cassia species (but not Ipomoea) showed accelerated, enhanced reproduction. Elevated CO[sub 2] ameliorated trade-offs between vegetative and floral production. However, seed [open quotes]quality[close quotes] and fitness were not always directly correlated with quantity produced. Species within general responded more consistently to CO[sub 2], indicating that phylogeny and life form may be general predictors of performance under global change.

  20. Food availability affects Osmia pumila (Hymenoptera: Megachilidae) foraging, reproduction, and brood parasitism.

    PubMed

    Goodell, Karen

    2003-03-01

    Food limitation can reduce reproductive success directly, as well as indirectly, if foraging imposes a risk of predation or parasitism. The solitary bee Osmia pumila suffers brood parasitism by the cleptoparasitic wasp Sapyga centrata, which enters the host nest to oviposit while the female bee is away. I studied foraging and reproduction of O. pumila nesting within cages stocked with rich or sparse floral resources, and the presence or absence of S. centrata to test (1) the response of nesting female O. pumila to food shortages, (2) the response of nesting female O. pumila to the presence of parasites, and (3) whether brood produced under scarce resources are more likely to be parasitized by S. centrata. The rate of brood cell production was significantly lower in cages with sparse floral resources, although females in sparse cages did not produce significantly fewer brood cells overall. Sapyga centrata did not influence the rate of brood cell production, but females exposed to the cleptoparasites had marginally significantly lower reproductive output. Nests in parasite cages had significantly fewer brood cells than those in parasite free cages. The mean duration of foraging bouts made by female O. pumila in sparse cages was not significantly longer than that in rich cages. O. pumila spent less time in the nest between pollen and nectar foraging bouts in sparse cages with S. centrata than those in other cages suggesting that these individuals made more frequent food foraging trips. Despite the weak effects of parasites and bloom density on foraging behavior, O. pumila brood cells experienced a 5-fold higher probability of parasitism by S. centrata in cages with sparse bloom than in those with rich bloom [corrected]. These results support the hypothesis that indirect effects of food scarcity increase O. pumila susceptibility to brood parasitism, although the exact mechanism is not entirely clear yet. PMID:12647124

  1. Reproduction of Pseudocalanus newmani (Copepoda: Calanoida) is deleteriously affected by diatom blooms A field study

    NASA Astrophysics Data System (ADS)

    Halsband-Lenk, Claudia; Pierson, James J.; Leising, Andrew W.

    2005-11-01

    Copepod secondary production has traditionally been linked to the spring diatom bloom in temperate and high latitudes, but laboratory studies have recently challenged this view and have shown either reduced fecundity or viability of offspring when copepods were fed high concentrations of - mostly unialgal - diatoms. However, field evidence that diatoms affect copepod reproduction is still scarce. We analyzed the reproductive response of a common, small calanoid copepod of the boreal Pacific, Pseudocalanus newmani, to spring diatom blooms in Dabob Bay, a semi-enclosed fjord of Puget Sound, Washington, USA. Abundance patterns, egg production rates, egg hatching success, and naupliar viability of the egg-carrying copepod were examined between February and early May in the years 2002-2004. The population underwent strong variations in abundance during both years, with high abundance of all stages from February to mid-March, but dramatically decreasing individual numbers later in spring. A recovery to higher numbers occurred in July. While egg production rates were independent of chlorophyll concentrations, the reproductive success of P. newmani was negatively affected by certain phytoplankton bloom conditions. Hatching success and - more markedly - naupliar survival were reduced following peaks of Thalassiosira species that were producing anti-mitotic aldehydes, but were high during periods when phytoplankton blooms were more diverse or dominated by other prey taxa including diatoms. As a consequence, recruitment of the naupliar population was considerably affected by the Thalassiosira blooms. This study shows for the first time that the so-called diatom effect operates in nature when all prerequisites - (1) high concentration of aldehyde producers, (2) few prey alternatives, and (3) feeding of copepods on these algae - are given. However, the effect was transient in Dabob Bay and may be so in other pelagic ecosystems. It remains to discern the potential sources of

  2. Food availability affects onset of reproduction in a long-lived seabird

    PubMed Central

    Vincenzi, Simone; Hatch, Scott; Mangel, Marc; Kitaysky, Alexander

    2013-01-01

    Life-history theory predicts that suboptimal developmental conditions may lead to faster life histories (younger age at recruitment and higher reproductive investment), but experimental testing of this prediction is still scarce in long-lived species. We report the effects of an experimental manipulation of food availability during early development and at recruitment on the onset of reproduction and reproductive performance (productivity at first breeding) in a long-lived seabird, the black-legged kittiwake Rissa tridactyla, breeding on Middleton Island, Alaska. Birds were born and raised in nests with supplemented food (‘fed’) or unsupplemented control nests (‘unfed’), and later recruited into either fed or unfed nests. Fed chicks grew faster than unfed chicks, and males grew faster than females. Birds were more likely to reproduce at younger ages when recruiting into fed nests. Faster growth during development tended to increase age at recruitment in all individuals. Social rank of individuals also affected age at recruitment: B-chicks recruited earlier than A-chicks and singletons recruited later than A- and B-chicks. Productivity increased with the age at recruitment and growth rate as chick, but much of the variability remained unexplained. We conclude that results of this study at least partially support predictions of life-history theory: younger age at first breeding for kittiwakes that experienced suboptimal natal conditions, as well as greater productivity of early recruiting kittiwakes that grew in control nests compared with those that grew in food-supplemented nests. PMID:23576791

  3. Fishing top predators indirectly affects condition and reproduction in a reef-fish community.

    PubMed

    Walsh, S M; Hamilton, S L; Ruttenberg, B I; Donovan, M K; Sandin, S A

    2012-03-01

    To examine the indirect effects of fishing on energy allocation in non-target prey species, condition and reproductive potential were measured for five representative species (two-spot red snapper Lutjanus bohar, arc-eye hawkfish Paracirrhites arcatus, blackbar devil Plectroglyphidodon dickii, bicolour chromis Chromis margaritifer and whitecheek surgeonfish Acanthurus nigricans) from three reef-fish communities with different levels of fishing and predator abundance in the northern Line Islands, central Pacific Ocean. Predator abundance differed by five to seven-fold among islands, and despite no clear differences in prey abundance, differences in prey condition and reproductive potential among islands were found. Body condition (mean body mass adjusted for length) was consistently lower at sites with higher predator abundance for three of the four prey species. Mean liver mass (adjusted for total body mass), an indicator of energy reserves, was also lower at sites with higher predator abundance for three of the prey species and the predator. Trends in reproductive potential were less clear. Mean gonad mass (adjusted for total body mass) was high where predator abundance was high for only one of the three species in which it was measured. Evidence of consistently low prey body condition and energy reserves in a diverse suite of species at reefs with high predator abundance suggests that fishing may indirectly affect non-target prey-fish populations through changes in predation and predation risk. PMID:22380551

  4. Analgesic exposure in pregnant rats affects fetal germ cell development with inter-generational reproductive consequences

    PubMed Central

    Dean, Afshan; van den Driesche, Sander; Wang, Yili; McKinnell, Chris; Macpherson, Sheila; Eddie, Sharon L.; Kinnell, Hazel; Hurtado-Gonzalez, Pablo; Chambers, Tom J.; Stevenson, Kerrie; Wolfinger, Elke; Hrabalkova, Lenka; Calarrao, Ana; Bayne, Rosey AL; Hagen, Casper P.; Mitchell, Rod T.; Anderson, Richard A.; Sharpe, Richard M.

    2016-01-01

    Analgesics which affect prostaglandin (PG) pathways are used by most pregnant women. As germ cells (GC) undergo developmental and epigenetic changes in fetal life and are PG targets, we investigated if exposure of pregnant rats to analgesics (indomethacin or acetaminophen) affected GC development and reproductive function in resulting offspring (F1) or in the F2 generation. Exposure to either analgesic reduced F1 fetal GC number in both sexes and altered the tempo of fetal GC development sex-dependently, with delayed meiotic entry in oogonia but accelerated GC differentiation in males. These effects persisted in adult F1 females as reduced ovarian and litter size, whereas F1 males recovered normal GC numbers and fertility by adulthood. F2 offspring deriving from an analgesic-exposed F1 parent also exhibited sex-specific changes. F2 males exhibited normal reproductive development whereas F2 females had smaller ovaries and reduced follicle numbers during puberty/adulthood; as similar changes were found for F2 offspring of analgesic-exposed F1 fathers or mothers, we interpret this as potentially indicating an analgesic-induced change to GC in F1. Assuming our results are translatable to humans, they raise concerns that analgesic use in pregnancy could potentially affect fertility of resulting daughters and grand-daughters. PMID:26813099

  5. Analysis of Factors Affecting Output Levels and Frequencies of MP3 Players

    PubMed Central

    2013-01-01

    Exposure to high levels of music that could lead to music induced hearing loss (MIHL) has been of recent interest especially for young adults, considering their excessive use of personal listening devices such as MP3 player. More attention should be drawn to MIHL for noting that early noise exposure leads to earlier onset of presbycusis. In search of appropriate and safe listening habits for young adults, this investigation was aimed to evaluate output levels and frequencies generated by the Samsung galaxy note MP3 player depending on two earphone types; ear-bud and over-the-ear earphones and three music genres; rock, hip-hop, ballade. A sound level meter was used to measure output level and frequency spectrum between 12.5 and 16000 Hz at all 1/3-octave bands. The following results can be summarized. 1) The earphone styles did not produce significant difference in output levels, but the music genres did. However, the results of music genres varied. 2) Neither earphone styles nor music genres produced significant difference in frequency response spectrum, except music genres at the volume settings we usually listen to. Additionally, volume levels should be lower than 50% for usual listening situation. Through this investigation, it was noted that the frequency range was substantial between 50 and 1000 Hz regardless of the styles of earphones and music genres, implying that we should be cautious of this frequency range when we listen to music. Researchers should give more attention to the effects of the mixture of output level and frequency spectrum, considering that the auditory system has frequency specificity from the periphery to the central to provide refined methods for protecting our ears from MIHL. PMID:24653908

  6. Analysis of Factors Affecting Output Levels and Frequencies of MP3 Players.

    PubMed

    Kim, Jinsook

    2013-09-01

    Exposure to high levels of music that could lead to music induced hearing loss (MIHL) has been of recent interest especially for young adults, considering their excessive use of personal listening devices such as MP3 player. More attention should be drawn to MIHL for noting that early noise exposure leads to earlier onset of presbycusis. In search of appropriate and safe listening habits for young adults, this investigation was aimed to evaluate output levels and frequencies generated by the Samsung galaxy note MP3 player depending on two earphone types; ear-bud and over-the-ear earphones and three music genres; rock, hip-hop, ballade. A sound level meter was used to measure output level and frequency spectrum between 12.5 and 16000 Hz at all 1/3-octave bands. The following results can be summarized. 1) The earphone styles did not produce significant difference in output levels, but the music genres did. However, the results of music genres varied. 2) Neither earphone styles nor music genres produced significant difference in frequency response spectrum, except music genres at the volume settings we usually listen to. Additionally, volume levels should be lower than 50% for usual listening situation. Through this investigation, it was noted that the frequency range was substantial between 50 and 1000 Hz regardless of the styles of earphones and music genres, implying that we should be cautious of this frequency range when we listen to music. Researchers should give more attention to the effects of the mixture of output level and frequency spectrum, considering that the auditory system has frequency specificity from the periphery to the central to provide refined methods for protecting our ears from MIHL. PMID:24653908

  7. Wearing knee wraps affects mechanical output and performance characteristics of back squat exercise.

    PubMed

    Lake, Jason P; Carden, Patrick J C; Shorter, Kath A

    2012-10-01

    The aim of this study was to investigate the effects of wearing knee wraps on mechanical output and performance characteristics of back squat exercise. Ten resistance trained men (back squat 1 repetition maximum [1RM]: 160.5 ± 18.4 kg) performed 6 single back squats with 80% 1RM, 3 wearing knee wraps, 3 without. Mechanical output was obtained from ground reaction force, performance characteristics from digitized motion footage obtained from a single high-speed digital camera. Wearing knee wraps led to a 39% reduction (0.09 compared with 0.11 m, p = 0.037) in horizontal barbell displacement that continued during the lifting phase. Lowering phase vertical impulse remained within 1% across conditions; however, the lowering phase was performed 45% faster (1.13 compared with 1.57 seconds). This demonstrated that vertical force applied to the center of mass during the lowering phase was considerably larger and was likely a consequence of the generation and storage of elastic energy within the knee wrap. Subsequent vertical impulse applied to the center of mass was 10% greater (192 compared with 169 N·s, p = 0.018). Mechanical work involved in vertically displacing the center of mass was performed 20% faster and was reflected by a 10% increase in peak power (2,121 compared with 1,841 W, p = 0.019). The elastic properties of knee wraps increased mechanical output but altered back squat technique in a way that is likely to alter the musculature targeted by the exercise and possibly compromise the integrity of the knee joint. Knee wraps should not be worn during the strength and condition process, and perceived weakness in the knee joint should be assessed and treated. PMID:22995993

  8. Evidence that elevated water temperature affects the reproductive physiology of the European bullhead Cottus gobio.

    PubMed

    Dorts, Jennifer; Grenouillet, Gaël; Douxfils, Jessica; Mandiki, Syaghalirwa N M; Milla, Sylvain; Silvestre, Frédéric; Kestemont, Patrick

    2012-04-01

    Climate change is predicted to increase the average water temperature and alter the ecology and physiology of several organisms including fish species. To examine the effects of increased water temperature on freshwater fish reproduction, adult European bullhead Cottus gobio of both genders were maintained under three temperature regimes (T1: 6-10, T2: 10-14 and T3: 14-18°C) and assessed for gonad development (gonadosomatic index-GSI and gonad histology), sex steroids (testosterone-T, 17β-estradiol-E2 and 11-ketotestosterone-11-KT) and vitellogenin (alkali-labile phosphoprotein phosphorus-ALP) dynamics in December, January, February and March. The results indicate that a 8°C rise in water temperature (T3) deeply disrupted the gonadal maturation in both genders. This observation was associated with the absence of GSI peak from January to March, and low levels of plasma sex steroids compared with T1-exposed fish. Nevertheless, exposure to an increasing temperature of 4°C (T2) appeared to accelerate oogenesis with an early peak value in GSI and level of plasma T recorded in January relative to T1-exposed females. In males, the low GSI, reduced level of plasma 11-KT and the absence of GSI increase from January to March support the deleterious effects of increasing water temperature on spermatogenesis. The findings of the present study suggest that exposure to elevated temperatures within the context of climate warming might affect the reproductive success of C. gobio. Specifically, a 4°C rise in water temperature affects gametogenesis by advancing the spawning, and a complete reproductive failure is observed at an elevated temperature of 8°C. PMID:21638008

  9. Corticosterone metabolism by chicken follicle cells does not affect ovarian reproductive hormone synthesis in vitro

    PubMed Central

    Rettenbacher, Sophie; Henriksen, Rie; Groothuids, Ton G.; Lepschy, Michael

    2013-01-01

    Glucocorticoids affect reproductive hormone production in many species. In chickens, elevated plasma corticosterone down-regulates testosterone and progesterone concentrations in plasma, but also in egg yolk. This suppression could be mediated via the hypothalamic-pituitary system but also via local inhibition of gonadal activity by glucocorticoids. As the latter has not been tested in birds yet, we tested if corticosterone directly inhibits ovarian steroid synthesis under in vitro conditions. We hypothesized that degradation of corticosterone by follicular cells impairs their ability to synthesize reproductive hormones due to either inhibition of enzymes or competition for common co-factors. Therefore, we first established whether follicles degrade corticosterone. Follicular tissue was harvested from freshly euthanized laying hens and incubated with radiolabelled corticosterone. Radioactive metabolites were visualized and quantified by autoradiography. Follicles converted corticosterone in a time-dependent manner into metabolites with a higher polarity than corticosterone. The predominant metabolite co-eluted with 20β-dihydrocorticosterone. Other chicken tissues mostly formed the same metabolite when incubated with corticosterone. In a second experiment, follicles were incubated with either progesterone or dehydroepiandrosterone. Corticosterone was added in increasing dosages up to 1000 ng per ml medium. Corticosterone did not inhibit the conversion of progesterone and dehydroepiandrosterone into a number of different metabolites, including 17α-hydroxyprogesterone, androstenedione and testosterone. In conclusion, avian tissues degrade corticosterone mostly to 20β-dihydrocorticosterone and even high corticosterone dosages do not affect follicular hormone production under in vitro conditions. PMID:23333751

  10. Adult nutrition and butterfly fitness: effects of diet quality on reproductive output, egg composition, and egg hatching success

    PubMed Central

    Geister, Thorin L; Lorenz, Matthias W; Hoffmann, Klaus H; Fischer, Klaus

    2008-01-01

    Background In the Lepidoptera it was historically believed that adult butterflies rely primarily on larval-derived nutrients for reproduction and somatic maintenance. However, recent studies highlight the complex interactions between storage reserves and adult income, and that the latter may contribute significantly to reproduction. Effects of adult diet were commonly assessed by determining the number and/or size of the eggs produced, whilst its consequences for egg composition and offspring viability were largely neglected (as is generally true for insects). We here specifically focus on these latter issues by using the fruit-feeding tropical butterfly Bicyclus anynana, which is highly dependent on adult-derived carbohydrates for reproduction. Results Adult diet of female B. anynana had pronounced effects on fecundity, egg composition and egg hatching success, with butterflies feeding on the complex nutrition of banana fruit performing best. Adding vitamins and minerals to a sucrose-based diet increased fecundity, but not offspring viability. All other groups (plain sucrose solution, sucrose solution enriched with lipids or yeast) had a substantially lower fecundity and egg hatching success compared to the banana group. Differences were particularly pronounced later in life, presumably indicating the depletion of essential nutrients in sucrose-fed females. Effects of adult diet on egg composition were not straightforward, indicating complex interactions among specific compounds. There was some evidence that total egg energy and water content were related to hatching success, while egg protein, lipid, glycogen and free carbohydrate content did not seem to limit successful development. Conclusion The patterns shown here exemplify the complexity of reproductive resource allocation in B. anynana, and the need to consider egg composition and offspring viability when trying to estimate the effects of adult nutrition on fitness in this butterfly and other insects. PMID

  11. Plumage color and reproductive output of eastern bluebirds (Sialia sialis) nesting near a mercury-contaminated river.

    PubMed

    McCullagh, Elizabeth A; Cristol, Daniel A; Phillips, John B

    2015-01-01

    Despite the growing evidence of mercury's impact on ecosystems, few studies have looked at the environmental impact of mercury pollution on terrestrial songbirds and the complex ways through which mercury might influence their fitness. In 2007-2008 eastern bluebirds (Sialia sialis) were monitored on mercury contaminated and reference sites for blood and feather mercury, reproductive success and plumage coloration. Higher tissue mercury accumulation was associated with plumage that was overall brighter and shifted towards the UV portion of the spectrum. In females, long-term mercury exposure, as indicated by feather mercury, was associated with smaller clutches of eggs. In males, recent mercury exposure, as indicated by blood mercury, was associated with a reduction in the proportion of hatchlings that fledged, potentially through reduced male provisioning of offspring. Reproductive success and plumage color are closely linked in bluebirds through mate choice, and our findings indicate that mercury contamination is associated with reproductive success directly and possibly indirectly, through coloration of bluebirds. PMID:26121017

  12. The impact of specialist and generalist pre-dispersal seed predators on the reproductive output of a common and a rare Euphorbia species

    NASA Astrophysics Data System (ADS)

    Boieiro, Mário; Rego, Carla; Serrano, Artur R. M.; Espadaler, Xavier

    2010-03-01

    Pre-dispersal seed predators can have a severe impact on the reproductive output of their hosts, which can translate into negative effects on population dynamics. Here we compared the losses due to specialist and generalist insect seed predators in two Euphorbia species, a rare ( Euphorbia welwitschii) and a common one ( Euphorbia characias). Pre-dispersal losses to specialist seed-wasps ( Eurytoma jaltica) and generalist hemipterans ( Cydnus aterrimus and Dicranocephalus agilis) were on average higher for the rare E. welwitschii than for its widespread congener. In both Euphorbia species, the variation in losses to specialist and generalist seed predators was not related with traits indicative of plant size, fecundity, or isolation. Nevertheless, the temporal variation in losses to seed-wasps seemed to be intimately associated with the magnitude of yearly variation in fruit production. The impact of seed-wasps and hemipterans on the reproductive output of both Euphorbia species was additive, though there was evidence for infochemical-mediated interference at the fruit level. The moderate levels of seed predation in E. welwitschii, together with the results from the comparative analysis with its widespread congener, suggest that insect seed predation is not a causal effect of plant rarity.

  13. Disruption of amylase genes by RNA interference affects reproduction in the Pacific oyster Crassostrea gigas.

    PubMed

    Huvet, Arnaud; Béguel, Jean-Philippe; Cavaleiro, Nathalia Pereira; Thomas, Yoann; Quillien, Virgile; Boudry, Pierre; Alunno-Bruscia, Marianne; Fabioux, Caroline

    2015-06-01

    Feeding strategies and digestive capacities can have important implications for variation in energetic pathways associated with ecological and economically important traits, such as growth or reproduction in bivalve species. Here, we investigated the role of amylase in the digestive processes of Crassostrea gigas, using in vivo RNA interference. This approach also allowed us to investigate the relationship between energy intake by feeding and gametogenesis in oysters. Double-stranded (ds)RNA designed to target the two α-amylase genes A and B was injected in vivo into the visceral mass of oysters at two doses. These treatments caused significant reductions in mean mRNA levels of the amylase genes: -50.7% and -59% mRNA A, and -71.9% and -70.6% mRNA B in 15 and 75 µg dsRNA-injected oysters, respectively, relative to controls. Interestingly, reproductive knock-down phenotypes were observed for both sexes at 48 days post-injection, with a significant reduction of the gonad area (-22.5% relative to controls) and germ cell under-proliferation revealed by histology. In response to the higher dose of dsRNA, we also observed reductions in amylase activity (-53%) and absorption efficiency (-5%). Based on these data, dynamic energy budget modeling showed that the limitation of energy intake by feeding that was induced by injection of amylase dsRNA was insufficient to affect gonadic development at the level observed in the present study. This finding suggests that other driving mechanisms, such as endogenous hormonal modulation, might significantly change energy allocation to reproduction, and increase the maintenance rate in oysters in response to dsRNA injection. PMID:25883379

  14. Metabolic stressors and signals differentially affect energy allocation between reproduction and immune function.

    PubMed

    Carlton, Elizabeth D; Cooper, Candace L; Demas, Gregory E

    2014-11-01

    Most free-living animals have finite energy stores that they must allocate to different physiological and behavioral processes. In times of energetic stress, trade-offs in energy allocation among these processes may occur. The manifestation of trade-offs may depend on the source (e.g., glucose, lipids) and severity of energy limitation. In this study, we investigated energetic trade-offs between the reproductive and immune systems by experimentally limiting energy availability to female Siberian hamsters (Phodopus sungorus) with 2-deoxy-d-glucose, a compound that disrupts cellular utilization of glucose. We observed how glucoprivation at two levels of severity affected allocation to reproduction and immunity. Additionally, we treated a subset of these hamsters with leptin, an adipose hormone that provides a direct signal of available fat stores, in order to determine how increasing this signal of fat stores influences glucoprivation-induced trade-offs. We observed trade-offs between the reproductive and immune systems and that these trade-offs depended on the severity of energy limitation and exogenous leptin signaling. The majority of the animals experiencing mild glucoprivation entered anestrus, whereas leptin treatment restored estrous cycling in these animals. Surprisingly, virtually all animals experiencing more severe glucoprivation maintained normal estrous cycling throughout the experiment; however, exogenous leptin resulted in lower antibody production in this group. These data suggest that variation in these trade-offs may be mediated by shifts between glucose and fatty acid utilization. Collectively, the results of the present study highlight the context-dependent nature of these trade-offs, as trade-offs induced by the same metabolic stressor can manifest differently depending on its intensity. PMID:25125082

  15. Factors affecting reproductive success in three entomophilous orchid species in Hungary.

    PubMed

    Vojtkó, Anna E; Sonkoly, Judit; Lukács, Balázs András; Molnár V, Attila

    2015-06-01

    The reproductive success of orchids is traditionally estimated by determining the fruit-set of individuals. Here, we investigated both the fruit and the seed production of three orchid species and the factors that may affect individual fruit-set, like pollination strategy, individual traits or the annual amount of precipitation. The species [Dactylorhiza sambucina (L.) Soó, Dactylorhiza majalis (Rchb.) P. F. Hunt & Summerhayes and Platanthera bifolia (L.) L. C. M. Richard] were studied in three consecutive years (2010-2012) in the Bükk Mountains, Hungary. All three species were proved to be non-autogamous by a bagging experiment. Data analyses showed significant differences between seed numbers but not between fruit-sets of species. There was no statistical difference in individual reproductive success between wet and dry years, however, the effect of the annual amount of precipitation is significant on the population level. Comparison of published fruit-set data revealed accordance with our results in P. bifolia, but not in D. sambucina and D. majalis. We assume that the surprisingly high fruit-set values of the two Dactylorhiza species may be due to the fact that the pollination crisis reported from Western European countries is not an actual problem in the Bükk Mountains, Hungary. PMID:26081278

  16. Spring phenology does not affect timing of reproduction in the great tit (Parus major).

    PubMed

    Schaper, Sonja V; Rueda, Carolina; Sharp, Peter J; Dawson, Alistair; Visser, Marcel E

    2011-11-01

    Many seasonal breeders adjust the timing of reproduction in response to year-to-year variations in supplementary environmental cues, amongst which ambient temperature is thought to be most influential. However, it is possible that for species such as the great tit (Parus major L.), phenological cues from sprouting vegetation and the consequent abundance of invertebrate prey, although dependent on temperature, may provide supplementary environmental cues per se. This hypothesis was investigated in breeding pairs of great tits kept in outdoor aviaries. In spring, experimental pairs were provided with access to leafing birch branches and caterpillars as a visual food cue, while control pairs were provided with non-leafing branches. Observations were made on the onset of laying and on concentrations of plasma luteinizing hormone (LH) at regular intervals to monitor changes in reproductive function. The onset of egg laying was not advanced by the presence of leafing branches and caterpillars. LH concentrations increased during the course of the study, but phenological cues did not affect plasma LH levels in females and males. Early spring vegetation, such as the leafing of birch branches, and the appearance of caterpillar prey do not appear to play a significant role in fine-tuning the onset of egg laying in great tits. PMID:21993796

  17. Second-Hand Eating? Maternal perception of the food environment affects reproductive investment in mice

    PubMed Central

    Schwartz, Tonia S.; Gainer, Renee; Dohm, Erik D.; Johnson, Maria S.; Wyss, J. Michael; Allison, David B.

    2015-01-01

    Objective Little information exists on how perception of the food (or ‘energetic’) environment affects body composition and reproductive investment. We test the hypothesis that female mice, who are themselves consuming standard chow diets, but who are exposed to conspecifics eating a rich “cafeteria diet”, will exhibit altered weight gain and reproductive investment. Design and Methods Female C57BL/6 mice were raised on a cafeteria diet. At maturity, subjects were switched to a standard chow diet and their cage-mate was assigned to consume either a cafeteria diet (treatment, n=20), or standard chow (control, n=20). Subjects were mated, and pups raised to weaning. Subjects and pups were analyzed for body composition. Results Treatment had no discernable effect on dam body weight or composition, but caused pups to have lower body weight (p=0.036), and less fat mass (p=0.041). We found a nearly significant treatment effect on ‘time to successful reproduction’ (avg. 55 vs. 44 days) likely due to increased failed first pregnancies (14/19 versus 8/19, p=0.099). Conclusions These data indicate that perceived food environment (independent of the diet actually consumed) can produce small pups with less body fat, and possibly induce difficulties in pregnancy for dams. Replication and mechanistic studies should follow. PMID:25864567

  18. Reproductive hacking

    PubMed Central

    Dustin Rubinstein, C; 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. PMID:25483253

  19. Effects of maternal exposure to aflatoxin B1 during pregnancy on fertility output of dams and developmental, behavioral and reproductive consequences in female offspring using a rat model.

    PubMed

    Supriya, Ch; Akhila, B; Pratap Reddy, K; Girish, B P; Sreenivasula Reddy, P

    2016-01-01

    A suboptimal in utero environment can have detrimental effects on the pregnancy and long-term adverse "programing" effects on the offspring. Aflatoxin B1 is one of the potent reproductive toxicants and currently detected in both milk and tissues. This article focuses on the effects of prenatal exposure to graded doses of aflatoxin B1 on the pregnancy outcomes of dams and postnatal developments of the female offspring, since these issues have ethological relevance in both animals and humans. Pregnant Wistar rats were injected intramuscularly with vehicle or aflatoxin B1 (10, 20, 50 or 100 μg/kg body weight/day) on days 12-19 of gestation. At parturition, newborns were observed for clinical signs of toxicity and survival. The female offspring were examined through a battery of tests in order to evaluate their developmental, behavioral and reproductive end points. All animals were born alive. The litter size of the aflatoxin B1 treated rats was comparable to the controls. However, the birth weight of the pups in the experimental group was significantly lower when compared to controls. Significant and persistent lags in cliff avoidance, negative geotaxis, surface rightening activity and ascending wire mesh, with a delay in elapsed time for vaginal opening were detected in the female progeny exposed to aflatoxin B1 during embryonic development. The locomotor activity and exploratory behavior in experimental females were significantly decreased than that of controls. Embryonic exposure to aflatoxin B1 also resulted in prolonged stress response, irregular estrus and suppressed fertility output in the progeny at their adulthood. These results indicate that in utero exposure to aflatoxin B1 severely compromised postnatal development of neonatal rats and caused irregular estrus that was accompanied by suppressed fertility output. PMID:26956420

  20. Ambient temperature shapes reproductive output during pregnancy and lactation in the common vole (Microtus arvalis): a test of the heat dissipation limit theory.

    PubMed

    Simons, Mirre J P; Reimert, Inonge; van der Vinne, Vincent; Hambly, Catherine; Vaanholt, Lobke M; Speakman, John R; Gerkema, Menno P

    2011-01-01

    The heat dissipation limit theory suggests that heat generated during metabolism limits energy intake and, thus, reproductive output. Experiments in laboratory strains of mice and rats, and also domestic livestock generally support this theory. Selection for many generations in the laboratory and in livestock has increased litter size or productivity in these animals. To test the wider validity of the heat dissipation limit theory, we studied common voles (Microtus arvalis), which have small litter sizes by comparison with mice and rats, and regular addition of wild-caught individuals of this species to our laboratory colony ensures a natural genetic background. A crossover design of ambient temperatures (21 and 30°C) during pregnancy and lactation was used. High ambient temperature during lactation decreased milk production, slowing pup growth. The effect on pup growth was amplified when ambient temperature was also high during pregnancy. Shaving fur off dams at 30°C resulted in faster growth of pups; however, no significant increase in food intake and or milk production was detected. With increasing litter size (natural and enlarged), asymptotic food intake during lactation levelled off in the largest litters at both 21 and 30°C. Interestingly, the effects of lactation temperature on pup growth where also observed at smaller litter sizes. This suggests that vole dams trade-off costs associated with hyperthermia during lactation with the yield from investment in pup growth. Moreover, pup survival was higher at 30°C, despite lower growth, probably owing to thermoregulatory benefits. It remains to be seen how the balance is established between the negative effect of high ambient temperature on maternal milk production and pup growth (and/or future reproduction of the dam) and the positive effect of high temperatures on pup survival. This balance ultimately determines the effect of different ambient temperatures on reproductive success. PMID:21147967

  1. Vouchers for health: A demand side output-based aid approach to reproductive health services in Kenya.

    PubMed

    Janisch, C P; Albrecht, M; Wolfschuetz, A; Kundu, F; Klein, S

    2010-01-01

    Reaching the United Nation's Millennium Development Goals has been a focus for many countries and development partners. In Kenya, as in many other countries with low levels of development, access to and equity of basic quality health services is limited, especially for the very poor. Among poor populations, maternal mortality is high as access to medical care and financial means are lacking. In 2005, the Governments of Kenya and Germany in cooperation with KfW Banking Group made funds available for the Reproductive Health OBA Voucher Programme offering vouchers for Safe Motherhood, Family Planning and Gender Violence Recovery Services. This programme, herein referred to as Vouchers for Health, was launched in June of 2006 in five Kenyan districts with the aim of providing health services for safe deliveries, long-term family planning methods and victims of gender violence. The way that the programme is being implemented in Kenya demonstrates that the voucher-based approach comprises a variety of key structural elements of a national health insurance scheme: accreditation; quality assurance; reimbursement system; claims processing; integrating the private sector; client choice; provider competition; and access to and equity of services provided. PMID:20099183

  2. A bibliometric analysis of bipolar affective disorders using density-equalizing mapping and output benchmarking

    PubMed Central

    Vogelzang, B. H.; Scutaru, C.; Mache, S.; Vitzthum, K.; Kusma, B.; Schulte-Herbrüggen, O; Groneberg, D. A.; Quarcoo, D.

    2012-01-01

    Background: Bipolar affective disorder (BaD) has a great impact on health systems worldwide. Although bibliometric studies have been done on this subject, these studies did not do an analysis of the contents of papers, the cooperation between countries, or of the names currently used to describe the condition. Furthermore, the number of publications since the last bibliometric study has doubled. Aim: This study was to examine the recent developments in the field, explore main topics/subject areas of the top 10 authors in this research field, and to compare diagnosis-defined data between International Classification of Diseases, 10th edition (ICD-10) and Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV). Materials and Methods: Using distinct search terms, the Web of Science database developed by the Thompson Reuters Institute of Scientific Information was scanned for relevant items published between 1900 and 2008. Results were analyzed using scientometric methods and density-equalizing calculations. Results: We found an important increase of publications on the subject over the last decade. Most published studies came from North America and Europe, while the countries cooperating with each other were comparable to other areas of medical research. Although there has been an increase in publications on BaD (m=3.3 publications per year in the last decade), the number of works using the term bipolar disorder (BD) was considerably higher (m=141.8 publications per year in the last decade). We found that the subject areas, genetics and pharmacology were focuses of research for the 10 most prolific authors, all of whom where psychiatrists. Conclusion: Research interest in BaD is rising. Reflecting the two main disease classification systems, DSM and ICD, both terms BD and BaD are used in research, with a preponderance of the former. The research of the most prolific authors engages genetic and pharmacological questions. PMID:23372233

  3. Intermittent fasting during winter and spring affects body composition and reproduction of a migratory duck

    USGS Publications Warehouse

    Barboza, P.S.; Jorde, D.G.

    2002-01-01

    We compared food intake, body mass and body composition of male and female black ducks (Anas rubripes) during winter (January-March). Birds were fed the same complete diet ad libitum on consecutive days each week without fasting (control; nine male; nine female) or with either short fasts (2 day.week-1; nine male; nine female), or long fasts (4 day.week-1; eleven male; twelve female). We continued treatments through spring (March-May) to measure the effect of intermittent fasts on body mass and egg production. Daily food intake of fasted birds was up to four times that of unfasted birds. Weekly food intake of males was similar among treatments (364 g.kg-1.week-1) but fasted females consumed more than unfasted females in January (363 g.kg-1.week-1 vs. 225 g.kg-1.week-1). Although both sexes lost 10-14% body mass, fasted females lost less mass and lipid than unfasted females during winter. Total body nitrogen was conserved over winter in both sexes even though the heart and spleen lost mass while the reproductive tract and liver gained mass. Intermittent fasting increased liver, intestinal tissue and digesta mass of females but not of males. Fasting delayed egg production in spring but did not affect size, fertility or hatching of the clutch. Females on long fasts were still heavier than controls after laying eggs. Thus black ducks combine flexibility of food intake with plasticity of digestive tract, liver and adipose tissue when food supply is interrupted during winter. Females modulate body mass for survival and defer reproduction when food supply is interrupted in spring.

  4. Selenium status affects selenoprotein expression, reproduction, and F₁ generation locomotor activity in zebrafish (Danio rerio).

    PubMed

    Penglase, Sam; Hamre, Kristin; Rasinger, Josef D; Ellingsen, Staale

    2014-06-14

    Se is an essential trace element, and is incorporated into selenoproteins which play important roles in human health. Mammalian selenoprotein-coding genes are often present as paralogues in teleost fish, and it is unclear whether the expression patterns or functions of these fish paralogues reflect their mammalian orthologues. Using the model species zebrafish (Danio rerio; ZF), we aimed to assess how dietary Se affects key parameters in Se metabolism and utilisation including glutathione peroxidase (GPX) activity, the mRNA expression of key Se-dependent proteins (gpx1a, gpx1b, sepp1a and sepp1b), oxidative status, reproductive success and F1 generation locomotor activity. From 27 d until 254 d post-fertilisation, ZF were fed diets with graded levels of Se ranging from deficient ( < 0·10 mg/kg) to toxic (30 mg/kg). The mRNA expression of gpx1a and gpx1b and GPX activity responded in a similar manner to changes in Se status. GPX activity and mRNA levels were lowest when dietary Se levels (0·3 mg/kg) resulted in the maximum growth of ZF, and a proposed bimodal mechanism in response to Se status below and above this dietary Se level was identified. The expression of the sepp1 paralogues differed, with only sepp1a responding to Se status. High dietary Se supplementation (30 mg/kg) decreased reproductive success, while the offspring of ZF fed above 0·3 mg Se/kg diet had lower locomotor activity than the other groups. Overall, the novel finding of low selenoprotein expression and activity coinciding with maximum body growth suggests that even small Se-induced variations in redox status may influence cellular growth rates. PMID:24666596

  5. Genetically Determined Dosage of Follicle-Stimulating Hormone (FSH) Affects Male Reproductive Parameters

    PubMed Central

    Grigorova, Marina; Punab, Margus; Ẑilaitienė, Birutė; Erenpreiss, Juris; Ausmees, Kristo; Matuleviĉius, Valentinas; Tsarev, Igor; Jørgensen, Niels

    2011-01-01

    Context: The detailed role of FSH in contributing to male testicular function and fertility has been debated. We have previously identified the association between the T-allele of the FSHB promoter polymorphism (rs10835638; G/T, −211 bp from the mRNA start) and significantly reduced male serum FSH. Objective: In the current study, the T-allele carriers of the FSHB −211 G/T single nucleotide polymorphism represented a natural model for documenting downstream phenotypic consequences of insufficient FSH action. Design and Subjects: We genotyped rs10835638 in the population-based Baltic cohort of young men (n = 1054; GG carriers, n = 796; GT carriers, n = 244; TT carriers, n = 14) recruited by Andrology Centres in Tartu, Estonia; Riga, Latvia; and Kaunas, Lithuania. Marker-trait association testing was performed using linear regression (additive, recessive models) adjusted by age, body mass index, smoking, and recruitment center. Results: Serum hormones directly correlated with the T-allele dosage of rs10835638 included FSH (additive model, P = 1.11 × 10−6; T-allele effect, −0.41 IU/liter), inhibin-B (P = 2.16 × 10−3; T-allele effect, −14.67 pg/ml), and total testosterone (P = 9.30 × 10−3; T-allele effect, −1.46 nmol/liter). Parameters altered only among TT homozygotes were reduced testicular volume (recessive model, P = 1.19 × 10−4; TT genotype effect, −9.47 ml) and increased serum LH (P = 2.25 × 10−2; TT genotype effect, 1.07 IU/liter). The carrier status of rs10835638 alternative genotypes did not affect sperm motility and morphology, calculated free testosterone, serum SHBG, and estradiol concentrations. Conclusion: We showed for the first time that genetically determined low FSH may have wider downstream effects on the male reproductive system, including impaired testes development, altered testicular hormone levels (inhibin-B, total testosterone, LH), and affected male reproductive potential. PMID:21733993

  6. Reproductive Hazards

    MedlinePlus

    ... such as lead and mercury Chemicals such as pesticides Cigarettes Some viruses Alcohol For men, a reproductive hazard can affect the sperm. For a woman, a reproductive hazard can cause different effects during pregnancy, depending on when she is exposed. ...

  7. Reproductive Hazards

    MedlinePlus

    ... and female reproductive systems play a role in pregnancy. Problems with these systems can affect fertility and ... a reproductive hazard can cause different effects during pregnancy, depending on when she is exposed. During the ...

  8. Offspring size at weaning affects survival to recruitment and reproductive performance of primiparous gray seals

    PubMed Central

    Bowen, William D; den Heyer, Cornelia E; McMillan, Jim I; Iverson, Sara J

    2015-01-01

    Offspring size affects survival and subsequent reproduction in many organisms. However, studies of offspring size in large mammals are often limited to effects on juveniles because of the difficulty of following individuals to maturity. We used data from a long-term study of individually marked gray seals (Halichoerus grypus; Fabricius, 1791) to test the hypothesis that larger offspring have higher survival to recruitment and are larger and more successful primiparous mothers than smaller offspring. Between 1998 and 2002, 1182 newly weaned female pups were branded with unique permanent marks on Sable Island, Canada. Each year through 2012, all branded females returning to the breeding colony were identified in weekly censuses and a subset were captured and measured. Females that survived were significantly longer offspring than those not sighted, indicating size-selective mortality between weaning and recruitment. The probability of female survival to recruitment varied among cohorts and increased nonlinearly with body mass at weaning. Beyond 51.5 kg (mean population weaning mass) weaning mass did not influence the probability of survival. The probability of female survival to recruitment increased monotonically with body length at weaning. Body length at primiparity was positively related to her body length and mass at weaning. Three-day postpartum mass (proxy for birth mass) of firstborn pups was also positively related to body length of females when they were weaned. However, females that were longer or heavier when they were weaned did not wean heavier firstborn offspring. PMID:25897381

  9. Female reproductive function in areas affected by radiation after the Chernobyl power station accident

    SciTech Connect

    Kulakov, V.I.; Sokur, T.N.; Volobuev, A.I.

    1993-07-01

    This paper reports the results of a comprehensive survey of the effects of the accidental release of radiation caused by the accident at the Chernobyl nuclear power station in April 1986. The accident and the resulting release of radiation and radioactive products into the atmosphere produced the most serious environmental contamination so far recorded. We have concentrated on evaluating the outcomes and health risks to women, their reproductive situation, and consequences for their progeny. We have concentrated on two well-defined areas: the Chechersky district of the Gomel region in Belorussia and the Polessky district of the Kiev region in the Ukraine. A number of investigations were carried out on 688 pregnant women and their babies, and data were obtained from 7000 labor histories of the development of newborns for a period of 8 years (3 years before the accident and 5 years after it). Parameters examined included birth rate, thyroid pathology, extragenital pathology such as anemias, renal disorders, hypertension, and abnormalities in the metabolism of fats, complications of gestation, spontaneous abortions, premature deliveries, perinatal morbidity and mortality, stillbirths and early neonatal mortality, infections and inflammatory diseases, neurological symptoms and hemic disturbances in both mothers and infants, trophic anomalies, and biochemical and structural changes in the placenta. Several exogenous, complicating influences were also considered such as psycho-emotional factors, stress, lifestyle changes, and others caused directly by the hazardous situation and by its consequences such as treatment, removal from affected areas, etc. 9 figs.

  10. Prenatal exposure to di-(2-ethylhexyl) phthalate (DEHP) affects reproductive outcomes in female mice.

    PubMed

    Niermann, Sarah; Rattan, Saniya; Brehm, Emily; Flaws, Jodi A

    2015-06-01

    This study tested the hypothesis that prenatal DEHP exposure affects female reproduction. To test this hypothesis, pregnant female CD-1 mice were orally dosed daily with tocopherol-stripped corn oil (vehicle control) or DEHP (20 μg/kg/day-750 mg/kg/day) from gestation day 11-birth. Pups were counted, weighed, and sexed at birth, ovaries were subjected to evaluations of follicle numbers on postnatal days (PNDs) 8 and 21, and fertility was evaluated at 3-9 months. The results indicate that prenatal DEHP exposure increased male-to-female ratio compared to controls. Prenatal DEHP exposure also increased preantral follicle numbers at PND 21 compared to controls. Further, 22.2% of the 20 μg/kg/day treated animals took longer than 5 days to get pregnant at 3 months and 28.6% of the 750 mg/kg/day treated animals lost some of their pups at 6 months. Thus, prenatal DEHP exposure alters F1 sex ratio, increases preantral follicle numbers, and causes some breeding abnormalities. PMID:25765777

  11. Offspring size at weaning affects survival to recruitment and reproductive performance of primiparous gray seals.

    PubMed

    Bowen, William D; den Heyer, Cornelia E; McMillan, Jim I; Iverson, Sara J

    2015-04-01

    Offspring size affects survival and subsequent reproduction in many organisms. However, studies of offspring size in large mammals are often limited to effects on juveniles because of the difficulty of following individuals to maturity. We used data from a long-term study of individually marked gray seals (Halichoerus grypus; Fabricius, 1791) to test the hypothesis that larger offspring have higher survival to recruitment and are larger and more successful primiparous mothers than smaller offspring. Between 1998 and 2002, 1182 newly weaned female pups were branded with unique permanent marks on Sable Island, Canada. Each year through 2012, all branded females returning to the breeding colony were identified in weekly censuses and a subset were captured and measured. Females that survived were significantly longer offspring than those not sighted, indicating size-selective mortality between weaning and recruitment. The probability of female survival to recruitment varied among cohorts and increased nonlinearly with body mass at weaning. Beyond 51.5 kg (mean population weaning mass) weaning mass did not influence the probability of survival. The probability of female survival to recruitment increased monotonically with body length at weaning. Body length at primiparity was positively related to her body length and mass at weaning. Three-day postpartum mass (proxy for birth mass) of firstborn pups was also positively related to body length of females when they were weaned. However, females that were longer or heavier when they were weaned did not wean heavier firstborn offspring. PMID:25897381

  12. Abdominally implanted satellite transmitters affect reproduction and survival rather than migration of large shorebirds

    USGS Publications Warehouse

    Hooijmeijer, Jos C. E. W.; Gill, Robert E., Jr.; Mulcahy, Daniel M.; Tibbitts, T. Lee; Kentie, Rosemarie; Gerritsen, Gerrit J.; Bruinzeel, Leo W.; Tijssen, David C.; Harwood, Christopher M.; Piersma, Theunis

    2014-01-01

    Satellite telemetry has become a common technique to investigate avian life-histories, but whether such tagging will affect fitness is a critical unknown. In this study, we evaluate multi-year effects of implanted transmitters on migratory timing and reproductive performance in shorebirds. Shorebirds increasingly are recognized as good models in ecology and evolution. That many of them are of conservation concern adds to the research responsibilities. In May 2009, we captured 56 female Black-tailed Godwits Limosa limosa limosa during late incubation in The Netherlands. Of these, 15 birds were equipped with 26-g satellite transmitters with a percutaneous antenna (7.8 % ± 0.2 SD of body mass), surgically implanted in the coelom. We compared immediate nest survival, timing of migration, subsequent nest site fidelity and reproductive behaviour including egg laying with those of the remaining birds, a comparison group of 41 females. We found no effects on immediate nest survival. Fledging success and subsequent southward and northward migration patterns of the implanted birds conformed to the expectations, and arrival time on the breeding grounds in 2010–2012 did not differ from the comparison group. Compared with the comparison group, in the year after implantation, implanted birds were equally faithful to the nest site and showed equal territorial behaviour, but a paucity of behaviours indicating nests or clutches. In the 3 years after implantation, the yearly apparent survival of implanted birds was 16 % points lower. Despite intense searching, we found only three eggs of two implanted birds; all were deformed. A similarly deformed egg was reported in a similarly implanted Whimbrel Numenius phaeopus returning to breed in central Alaska. The presence in the body cavity of an object slightly smaller than a normal egg may thus lead to egg malformation and, likely, reduced egg viability. That the use of implanted satellite transmitters in these large shorebirds

  13. Using GIS mapping of the extent of nearshore rocky reefs to estimate the abundance and reproductive output of important fishery species.

    PubMed

    Claisse, Jeremy T; Pondella, Daniel J; Williams, Jonathan P; Sadd, James

    2012-01-01

    Kelp Bass (Paralabrax clathratus) and California Sheephead (Semicossyphus pulcher) are economically and ecologically valuable rocky reef fishes in southern California, making them likely indicator species for evaluating resource management actions. Multiple spatial datasets, aerial and satellite photography, underwater observations and expert judgment were used to produce a comprehensive map of nearshore natural rocky reef habitat for the Santa Monica Bay region (California, USA). It was then used to examine the relative contribution of individual reefs to a regional estimate of abundance and reproductive potential of the focal species. For the reefs surveyed for fishes (i.e. 18 out of the 22 in the region, comprising 82% the natural rocky reef habitat <30 m depth, with a total area of 1850 ha), total abundance and annual egg production of California Sheephead were 451 thousand fish (95% CI: 369 to 533 thousand) and 203 billion eggs (95% CI: 135 to 272 billion). For Kelp Bass, estimates were 805 thousand fish (95% CI: 669 to 941 thousand) and 512 billion eggs (95% CI: 414 to 610 billion). Size structure and reef area were key factors in reef-specific contributions to the regional egg production. The size structures of both species illustrated impacts from fishing, and results demonstrate the potential that relatively small increases in the proportion of large females on larger reefs could have on regional egg production. For California Sheephead, a substantial proportion of the regional egg production estimate (>30%) was produced from a relatively small proportion of the regional reef area (c. 10%). Natural nearshore rocky reefs make up only 11% of the area in the newly designated MPAs in this region, but results provide some optimism that regional fisheries could benefit through an increase in overall reproductive output, if adequate increases in size structure of targeted species are realized. PMID:22272326

  14. Using GIS Mapping of the Extent of Nearshore Rocky Reefs to Estimate the Abundance and Reproductive Output of Important Fishery Species

    PubMed Central

    Claisse, Jeremy T.; Pondella, Daniel J.; Williams, Jonathan P.; Sadd, James

    2012-01-01

    Kelp Bass (Paralabrax clathratus) and California Sheephead (Semicossyphus pulcher) are economically and ecologically valuable rocky reef fishes in southern California, making them likely indicator species for evaluating resource management actions. Multiple spatial datasets, aerial and satellite photography, underwater observations and expert judgment were used to produce a comprehensive map of nearshore natural rocky reef habitat for the Santa Monica Bay region (California, USA). It was then used to examine the relative contribution of individual reefs to a regional estimate of abundance and reproductive potential of the focal species. For the reefs surveyed for fishes (i.e. 18 out of the 22 in the region, comprising 82% the natural rocky reef habitat <30 m depth, with a total area of 1850 ha), total abundance and annual egg production of California Sheephead were 451 thousand fish (95% CI: 369 to 533 thousand) and 203 billion eggs (95% CI: 135 to 272 billion). For Kelp Bass, estimates were 805 thousand fish (95% CI: 669 to 941thousand) and 512 billion eggs (95% CI: 414 to 610 billion). Size structure and reef area were key factors in reef-specific contributions to the regional egg production. The size structures of both species illustrated impacts from fishing, and results demonstrate the potential that relatively small increases in the proportion of large females on larger reefs could have on regional egg production. For California Sheephead, a substantial proportion of the regional egg production estimate (>30%) was produced from a relatively small proportion of the regional reef area (c. 10%). Natural nearshore rocky reefs make up only 11% of the area in the newly designated MPAs in this region, but results provide some optimism that regional fisheries could benefit through an increase in overall reproductive output, if adequate increases in size structure of targeted species are realized. PMID:22272326

  15. Can aircraft noise less than or equal 115 to dBA adversely affect reproductive outcome in USAF women?

    NASA Astrophysics Data System (ADS)

    Brubaker, P. A.

    1985-06-01

    It has been suggested, mainly through animal studies, that exposure to high noise levels may be associated with lower birth weight, reduced gestational length and other adverse reproductive outcomes. Few studies have been done on humans to show this association. The Air Force employs pregnant women in areas where there is a high potential for exposure to high noise levels. This study proposes a method to determine if there is an association between high frequency noise levels or = 115 dBA and adverse reproductive outcomes through a review of records and self-administered questionnaires in a case-comparison design. Prevelance rates will be calculated and a multiple logistic regression analysis computed for the independent variables that can affect reproduction.

  16. Conditions during adulthood affect cohort-specific reproductive success in an Arctic-nesting goose population

    PubMed Central

    Bearhop, Stuart; Hilton, Geoff M.; Walsh, Alyn; Fox, Anthony David

    2016-01-01

    Variation in fitness between individuals in populations may be attributed to differing environmental conditions experienced among birth (or hatch) years (i.e., between cohorts). In this study, we tested whether cohort fitness could also be explained by environmental conditions experienced in years post-hatch, using 736 lifelong resighting histories of Greenland white-fronted geese (Anser albifrons flavirostris) marked in their first winter. Specifically, we tested whether variation in age at first successful reproduction, the size of the first successful brood and the proportion of successful breeders by cohort was explained by environmental conditions experienced on breeding areas in west Greenland during hatch year, those in adulthood prior to successful reproduction and those in the year of successful reproduction, using North Atlantic Oscillation indices as proxies for environmental conditions during these periods. Fifty-nine (8%) of all marked birds reproduced successfully (i.e., were observed on wintering areas with young) only once in their lifetime and 15 (2%) reproduced successfully twice or thrice. Variation in age at first successful reproduction was explained by the environmental conditions experienced during adulthood in the years prior to successful reproduction. Birds bred earliest (mean age 4) when environmental conditions were ‘good’ prior to the year of successful reproduction. Conversely, birds successfully reproduced at older ages (mean age 7) if they experienced adverse conditions prior to the year of successful reproduction. Hatch year conditions and an interaction between those experienced prior to and during the year of successful reproduction explained less (marginally significant) variation in age at first successful reproduction. Environmental conditions did not explain variation in the size of the first successful brood or the proportion of successful breeders. These findings show that conditions during adulthood prior to the year of

  17. Conditions during adulthood affect cohort-specific reproductive success in an Arctic-nesting goose population.

    PubMed

    Weegman, Mitch D; Bearhop, Stuart; Hilton, Geoff M; Walsh, Alyn; Fox, Anthony David

    2016-01-01

    Variation in fitness between individuals in populations may be attributed to differing environmental conditions experienced among birth (or hatch) years (i.e., between cohorts). In this study, we tested whether cohort fitness could also be explained by environmental conditions experienced in years post-hatch, using 736 lifelong resighting histories of Greenland white-fronted geese (Anser albifrons flavirostris) marked in their first winter. Specifically, we tested whether variation in age at first successful reproduction, the size of the first successful brood and the proportion of successful breeders by cohort was explained by environmental conditions experienced on breeding areas in west Greenland during hatch year, those in adulthood prior to successful reproduction and those in the year of successful reproduction, using North Atlantic Oscillation indices as proxies for environmental conditions during these periods. Fifty-nine (8%) of all marked birds reproduced successfully (i.e., were observed on wintering areas with young) only once in their lifetime and 15 (2%) reproduced successfully twice or thrice. Variation in age at first successful reproduction was explained by the environmental conditions experienced during adulthood in the years prior to successful reproduction. Birds bred earliest (mean age 4) when environmental conditions were 'good' prior to the year of successful reproduction. Conversely, birds successfully reproduced at older ages (mean age 7) if they experienced adverse conditions prior to the year of successful reproduction. Hatch year conditions and an interaction between those experienced prior to and during the year of successful reproduction explained less (marginally significant) variation in age at first successful reproduction. Environmental conditions did not explain variation in the size of the first successful brood or the proportion of successful breeders. These findings show that conditions during adulthood prior to the year of

  18. Reproductive state affects hiding behaviour under risk of predation but not exploratory activity of female Spanish terrapins.

    PubMed

    Ibáñez, Alejandro; Marzal, Alfonso; López, Pilar; Martín, José

    2015-02-01

    Female investment during reproduction may reduce survivorship due to increased predation risk. During pregnancy, the locomotor performance of gravid females might be diminished due to the additional weight acquired. In addition, egg production may also increase thermoregulatory, metabolic and physiological costs. Also, pregnant females have greater potential fitness and should take fewer risks. Thus, females should ponder their reproductive state when considering their behavioural responses under risky situations. Here, we examine how reproductive state influence risk-taking behaviour in different contexts in female Spanish terrapins (Mauremys leprosa). We simulated predator attacks of different risk levels and measured the time that the turtles spent hiding entirely inside their own shells (i.e. appearance times). We also assessed the subsequent time after emergence from the shell that the turtles spent immobile monitoring for predators before starting to escape actively (i.e. waiting times). Likewise, we performed a novel-environment test and measured the exploratory activity of turtles. We found no correlations between appearance time, waiting time or exploratory activity, but appearance times were correlated across different risk levels. Only appearance time was affected by the reproductive state, where gravid females reappeared relatively later from their shells after a predator attack than non-gravid ones. Moreover, among gravid females, those carrying greater clutches tended to have longer appearance times. This suggests that only larger clutches could affect hiding behaviour in risky contexts. In contrast, waiting time spent scanning for predators and exploratory activity were not affected by the reproductive state. These differences between gravid and non-gravid females might be explained by the metabolic-physiological costs associated with egg production and embryo maintenance, as well as by the relatively higher potential fitness of gravid females. PMID

  19. ANDROGENS AND ENVIRONMENTAL ANTIANDROGENS AFFECT REPRODUCTIVE DEVELOPMENT AND PLAY BEHAVIOR IN THE SPRAGUE-DAWLEY RAT

    EPA Science Inventory

    Abstract: In mammals, exposure to androgens early in development is essential for masculinization of the male reproductive phenotype. Male fetuses exposed to antiandrogens during perinatal life are permanently demasculinized in their morphology and physiology, whereas exposure to...

  20. Mortality affects adaptive allocation to growth and reproduction: field evidence from a guild of body snatchers

    PubMed Central

    2010-01-01

    Background The probability of being killed by external factors (extrinsic mortality) should influence how individuals allocate limited resources to the competing processes of growth and reproduction. Increased extrinsic mortality should select for decreased allocation to growth and for increased reproductive effort. This study presents perhaps the first clear cross-species test of this hypothesis, capitalizing on the unique properties offered by a diverse guild of parasitic castrators (body snatchers). I quantify growth, reproductive effort, and expected extrinsic mortality for several species that, despite being different species, use the same species' phenotype for growth and survival. These are eight trematode parasitic castrators—the individuals of which infect and take over the bodies of the same host species—and their uninfected host, the California horn snail. Results As predicted, across species, growth decreased with increased extrinsic mortality, while reproductive effort increased with increased extrinsic mortality. The trematode parasitic castrator species (operating stolen host bodies) that were more likely to be killed by dominant species allocated less to growth and relatively more to current reproduction than did species with greater life expectancies. Both genders of uninfected snails fit into the patterns observed for the parasitic castrator species, allocating as much to growth and to current reproduction as expected given their probability of reproductive death (castration by trematode parasites). Additionally, species differences appeared to represent species-specific adaptations, not general plastic responses to local mortality risk. Conclusions Broadly, this research illustrates that parasitic castrator guilds can allow unique comparative tests discerning the forces promoting adaptive evolution. The specific findings of this study support the hypothesis that extrinsic mortality influences species differences in growth and reproduction

  1. Reproductive rate, not dominance status, affects fecal glucocorticoid levels in breeding female meerkats.

    PubMed

    Barrette, Marie-France; Monfort, Steven L; Festa-Bianchet, Marco; Clutton-Brock, Tim H; Russell, Andrew F

    2012-04-01

    Glucocorticoid hormones (GCs) have been studied intensively to understand the associations between physiological stress and reproductive skew in animal societies. However, we have little appreciation of the range of either natural levels within and among individuals, or the associations among dominance status, reproductive rate and GCs levels during breeding. To address these shortcomings, we examined variation in fecal glucocorticoid metabolites (fGC) during breeding periods in free-ranging female meerkats (Suricata suricatta) over 11 years. The vast majority of variation in fGC levels was found within breeding events by the same female (~87%), with the remaining variation arising among breeding events and among females. Concentrations of fGC generally tripled as pregnancy progressed. However, females with a high reproductive rate, defined as those conceiving within a month following parturition (mean = 9 days postpartum), showed significant reductions in fGC in the final 2 weeks before parturition. Despite these reductions, females with a high reproductive rate had higher fGC levels at conception of the following litter than those breeding at a low rate. After controlling for the higher reproductive rate of dominants, we found no association between levels of fGC and either age or dominance status. Our results suggest that one should be cautious about interpreting associations between dominance status, reproductive skew and GCs levels, without knowledge of the natural variation in GCs levels within and among females. PMID:22210199

  2. Father's death does not affect growth and maturation but hinders reproduction: evidence from adolescent girls in post-war Estonia.

    PubMed

    Hõrak, Peeter; Valge, Markus

    2015-12-01

    The popular concept of predictive-adaptive responses poses that girls growing up without a father present in the family mature and start reproduction earlier because the father's absence is a cue for environmental harshness and uncertainty that favours switching to a precocious life-history strategy. Most studies supporting this concept have been performed in situations where the father's absence is caused by divorce or abandonment. Using a dataset of Estonian adolescent girls who had lost their fathers over the period of World War II, we show that father's death did not affect the rate of pubertal maturation (assessed on the basis of development of breasts and axillary hair) or growth. Father's death did not affect the age of first birth but, contrary to predictions, reduced lifetime reproductive success. Our findings thus do not support the concept of predictive-adaptive responses and suggest that alternative explanations for covariation between fatherlessness and early maturation are required. PMID:26673934

  3. Mutations of the Drosophila Myosin Regulatory Light Chain Affect Courtship Song and Reduce Reproductive Success

    PubMed Central

    Chakravorty, Samya; Vu, Hien; Foelber, Veronica; Vigoreaux, Jim O.

    2014-01-01

    The Drosophila indirect flight muscles (IFM) rely on an enhanced stretch-activation response to generate high power output for flight. The IFM is neurally activated during the male courtship song, but its role, if any, in generating the small amplitude wing vibrations that produce the song is not known. Here, we examined the courtship song properties and mating behavior of three mutant strains of the myosin regulatory light chain (DMLC2) that are known to affect IFM contractile properties and impair flight: (i) Dmlc2Δ2–46 (Ext), an N-terminal extension truncation; (ii) Dmlc2S66A,S67A (Phos), a disruption of two MLC kinase phosphorylation sites; and (iii) Dmlc2Δ2–46;S66A,S67A (Dual), expressing both mutations. Our results show that the Dmlc2 gene is pleiotropic and that mutations that have a profound effect on flight mechanics (Phos and Dual) have minimal effects on courtship song. None of the mutations affect interpulse interval (IPI), a determinant of species-specific song, and intrapulse frequency (IPF) compared to Control (Dmlc2+ rescued null strain). However, abnormalities in the sine song (increased frequency) and the pulse song (increased cycles per pulse and pulse length) evident in Ext males are not apparent in Dual males suggesting that Ext and Phos interact differently in song and flight mechanics, given their known additive effect on the latter. All three mutant males produce a less vigorous pulse song and exhibit impaired mating behavior compared to Control males. As a result, females are less receptive to Ext, Phos, and Dual males when a Control male is present. These results open the possibility that DMLC2, and perhaps contractile protein genes in general, are partly under sexual selection. That mutations in DMLC2 manifest differently in song and flight suggest that this protein fulfills different roles in song and flight and that stretch activation plays a smaller role in song production than in flight. PMID:24587213

  4. Sexual experience affects reproductive behavior and preoptic androgen receptors in male mice

    PubMed Central

    Swaney, William T.; Dubose, Brittany N.; Curley, James P.; Champagne, Frances A.

    2012-01-01

    Reproductive behavior in male rodents is made up of anticipatory and consummatory elements which are regulated in the brain by sensory systems, reward circuits and hormone signaling. Gonadal steroids play a key role in the regulation of male sexual behavior via steroid receptors in the hypothalamus and preoptic area. Typical patterns of male reproductive behavior have been characterized, however these are not fixed but are modulated by adult experience. We assessed the effects of repeated sexual experience on male reproductive behavior of C57BL/6 mice; including measures of olfactory investigation of females, mounting, intromission and ejaculation. The effects of sexual experience on the number of cells expressing either androgen receptor (AR) or estrogen receptor alpha (ERα) in the primary brain nuclei regulating male sexual behavior was also measured. Sexually experienced male mice engaged in less sniffing of females before initiating sexual behavior and exhibited shorter latencies to mount and intromit, increased frequency of intromission, and increased duration of intromission relative to mounting. No changes in numbers of ERα-positive cells were observed, however sexually experienced males had increased numbers of AR-positive cells in the medial preoptic area (MPOA); the primary regulatory nucleus for male sexual behavior. These results indicate that sexual experience results in a qualitative change in male reproductive behavior in mice that is associated with increased testosterone sensitivity in the MPOA and that this nucleus may play a key integrative role in mediating the effects of sexual experience on male behavior. PMID:22266118

  5. DIBROMOACETIC ACID AFFECTS REPRODUCTIVE COMPETENCE AND SPERM QUALITY IN THE MALE RAT

    EPA Science Inventory

    We have recently shown that Dibromoacetic acid (DBAA) alters sperm quality in short duration tests. n this study, male rats were gavaged with 0, 2, 10, 50, 250 mg DBAA/kg/d for up to 49 d. Interim. and terminal measurements of sperm quality & reproductive outcome were made. BAA c...

  6. Age and reproductive status of adult Varroa mites affect grooming success of honey bees.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated for the first time the grooming response of honey bees to different ages and reproductive statuses of varroa mites in the laboratory. Plastic cages containing a section of dark comb and about 200 bees were inoculated with groups of four different classes of mites: gravid, phoret...

  7. Benzyl isothiocyanate affects development, hatching and reproduction of the soybean cyst nematode Heterodera glycines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Benzyl isothiocyanate (BITC) applied at micromolar doses decreased Heterodera glycines J2 movement, H. glycines hatching, and reproduction of H. glycines on soybean, Glycine max. Direct exposure of J2 to 30 microM BITC caused an immediate decrease (17%; P < 0.05) in J2 movement relative to 1% methan...

  8. Within-species reproductive costs affect the asymmetry of satyrization in Drosophila.

    PubMed

    Yassin, A; David, J R

    2016-02-01

    Understanding how species interactions influence their distribution and evolution is a fundamental question in evolutionary biology. Theory suggests that asymmetric reproductive interference, in which one species induces higher reproductive costs on another species, may be more important in delimiting species boundaries than interspecific competition over resources. However, the underlying mechanisms of such asymmetry remain unclear. Here, we test whether differences in within-species reproductive costs determine the between-species asymmetry of costs using three allopatric Drosophila species belonging to the melanogaster subgroup. Our results support this hypothesis, especially in a pair of insular species. Males of one species that induce costs to their conspecific females led to a 5-fold increase of heterospecific females mortality with dead flies bearing spectacular large melanized wounds on their genitalia. Males of the other species were harmful neither to their conspecific nor heterospecific females. Comparative studies of within-species reproductive costs may therefore be a valuable tool for predicting between-species interactions and community structures. PMID:26538290

  9. Transgenerational interactions involving parental age and immune status affect female reproductive success in Drosophila melanogaster

    PubMed Central

    Nystrand, M.; Dowling, D. K.

    2014-01-01

    It is well established that the parental phenotype can influence offspring phenotypic expression, independent of the effects of the offspring's own genotype. Nonetheless, the evolutionary implications of such parental effects remain unclear, partly because previous studies have generally overlooked the potential for interactions between parental sources of non-genetic variance to influence patterns of offspring phenotypic expression. We tested for such interactions, subjecting male and female Drosophila melanogaster of two different age classes to an immune activation challenge or a control treatment. Flies were then crossed in all age and immune status combinations, and the reproductive success of their immune- and control-treated daughters measured. We found that daughters produced by two younger parents exhibited reduced reproductive success relative to those of other parental age combinations. Furthermore, immune-challenged daughters exhibited higher reproductive success when produced by immune-challenged relative to control-treated mothers, a pattern consistent with transgenerational immune priming. Finally, a complex interplay between paternal age and parental immune statuses influenced daughter's reproductive success. These findings demonstrate the dynamic nature of age- and immune-mediated parental effects, traceable to both parents, and regulated by interactions between parents and between parents and offspring. PMID:25253454

  10. Social Variables Affecting Mate Preferences, Copulation and Reproductive Outcome in a Pack of Free-Ranging Dogs

    PubMed Central

    Valsecchi, Paola; Natoli, Eugenia

    2014-01-01

    Mating and reproductive outcome is often determined by the simultaneous operation of different mechanisms like intra-sexual competition, mating preferences and sexual coercion. The present study investigated how social variables affected mating outcome in a pack of free-ranging dogs, a species supposed to have lost most features of the social system of wolves during domestication. We found that, although the pack comprised multiple breeding individuals, both male copulation success and female reproductive success were positively influenced by a linear combination of dominance rank, age and leadership. Our results also suggest that mate preferences affect mating outcome by reinforcing the success of most dominant individuals. In particular, during their oestrous period bitches clearly searched for the proximity of high-ranking males who displayed affiliative behaviour towards them, while they were more likely to reject the males who intimidated them. At the same time, male courting effort and male-male competition for receptive females appeared to be stronger in the presence of higher-ranking females, suggesting a male preference for dominant females. To our knowledge, these results provide the first clear evidence of social regulation of reproductive activities in domestic dogs, and suggest that some common organizing mechanisms may contribute to shape the social organization of both dogs and wolves. PMID:24905360

  11. Social variables affecting mate preferences, copulation and reproductive outcome in a pack of free-ranging dogs.

    PubMed

    Cafazzo, Simona; Bonanni, Roberto; Valsecchi, Paola; Natoli, Eugenia

    2014-01-01

    Mating and reproductive outcome is often determined by the simultaneous operation of different mechanisms like intra-sexual competition, mating preferences and sexual coercion. The present study investigated how social variables affected mating outcome in a pack of free-ranging dogs, a species supposed to have lost most features of the social system of wolves during domestication. We found that, although the pack comprised multiple breeding individuals, both male copulation success and female reproductive success were positively influenced by a linear combination of dominance rank, age and leadership. Our results also suggest that mate preferences affect mating outcome by reinforcing the success of most dominant individuals. In particular, during their oestrous period bitches clearly searched for the proximity of high-ranking males who displayed affiliative behaviour towards them, while they were more likely to reject the males who intimidated them. At the same time, male courting effort and male-male competition for receptive females appeared to be stronger in the presence of higher-ranking females, suggesting a male preference for dominant females. To our knowledge, these results provide the first clear evidence of social regulation of reproductive activities in domestic dogs, and suggest that some common organizing mechanisms may contribute to shape the social organization of both dogs and wolves. PMID:24905360

  12. Water availability and population origin affect the expression of the tradeoff between reproduction and growth in Plantago coronopus.

    PubMed

    Hansen, C F; García, M B; Ehlers, B K

    2013-05-01

    Investment in reproduction and growth represent a classic tradeoff with implication for life history evolution. The local environment can play a major role in the magnitude and evolutionary consequences of such a tradeoff. Here, we examined the investment in reproductive and vegetative tissue in 40 maternal half-sib families from four different populations of the herb Plantago coronopus growing in either a dry or wet greenhouse environment. Plants originated from populations with an annual or a perennial life form, with annuals prevailing in drier habitats with greater seasonal variation in both temperature and precipitation. We found that water availability affected the expression of the tradeoff (both phenotypic and genetic) between reproduction and growth, being most accentuated under dry condition. However, populations responded very differently to water treatments. Plants from annual populations showed a similar response to drought condition with little variation among maternal families, suggesting a history of selection favouring genotypes with high allocation to reproduction when water availability is low. Plants from annual populations also expressed the highest level of plasticity. For the perennial populations, one showed a large variation among maternal families in resource allocation and expressed significant negative genetic correlations between reproductive and vegetative biomass under drought. The other perennial population showed less variation in response to treatment and had trait values similar to those of the annuals, although it was significantly less plastic. We stress the importance of considering intraspecific variation in response to environmental change such as drought, as conspecific plants exhibited very different abilities and strategies to respond to high versus low water availability even among geographically close populations. PMID:23621367

  13. How does childhood socioeconomic hardship affect reproductive strategy? Pathways of development

    PubMed Central

    Pearce, Mark S.; Sear, Rebecca

    2015-01-01

    Objectives In high‐income populations, evidence suggests that socioeconomic disadvantage early in life is correlated with reproductive strategy. Children growing up in unfavorable rearing environments tend to experience earlier sexual maturity and first births. Earlier first births may be associated with higher fertility, but links between socioeconomic disadvantage and larger family size have rarely been tested. The pathways through which early disadvantage influences reproduction are unknown. We test whether physiological factors link childhood adversity to age at first birth and total children. Methods Using data from the Newcastle Thousand Families Study, a 1947 British birth cohort, we developed path models to identify possible physiological traits linking childhood socioeconomic status, and poor housing standards, to two reproductive outcomes: age at first birth and total children. We explored birth weight, weight gain after birth, childhood illnesses, body mass index at age 9, age at menarche, and adult height as possible mediators. Results We found direct, negative effects of socioeconomic status (SES) and housing on age at first birth, and of housing on fertility. Although we found links between childhood disadvantage and menarche and height, neither of these were significantly correlated with either reproductive outcome. Age at first birth completely mediates the relationship between childhood adversity and total fertility, which we believe has not been empirically demonstrated before. Conclusions While there are some links between childhood adversity and child health, we find little evidence that physiological pathways, such as child health and growth, link early childhood adversity to reproductive outcomes in this relatively well‐nourished population. Am. J. Hum. Biol. 28:356–363, 2016. © 2015 The Authors American Journal of Human Biology Published by Wiley Periodicals, Inc. PMID:26407916

  14. Microcystin-LR impairs zebrafish reproduction by affecting oogenesis and endocrine system.

    PubMed

    Zhao, Yanyan; Xie, Liqiang; Yan, Yunjun

    2015-02-01

    Previous studies have shown that microcystins (MCs) are able to exert negative effects on the reproductive system of fish. However, few data are actually available on the effects of MC-LR on the reproductive system of female fish. In the present study, female zebrafish were exposed to 2, 10, and 50 μg L(-1) of MC-LR for 21 d, and its effects on oogenesis, sex hormones, transcription of genes on the hypothalamic-pituitary-gonad (HPG) axis, and reproduction were investigated for the first time. It was observed that egg production significantly declined at ⩾ 10 μg L(-1) MC-LR. MC-LR exposure to zebrafish increased the concentrations of 17β-estradiol (E2) and vitellogenin (VTG) at 10 μg L(-1) level, whereas concentrations of E2, VTG and testosterone declined at 50 μg L(-1) MC-LR. The transcriptions of steroidogenic pathway gene (cyp19a, cyp19b, 17βhsd, cyp17 and hmgra) changed as well after the exposure and corresponded well with the alterations of hormone levels. A number of intra- and extra-ovarian factors, such as gnrh3, gnrhr1, fshβ, fshr, lhr, bmp15, mrpβ, ptgs2 and vtg1 which regulate oogenesis, were significantly changed with a different dose-related effect. Moreover, MC-LR exposure to female zebrafish resulted in decreased fertilization and hatching rates, and may suggest the possibility of trans-generational effects of MC-LR exposure. The results demonstrate that MC-LR could modulate endocrine function and oogenesis, eventually leading to disruption of reproductive performance in female zebrafish. These data suggest there is a risk for aquatic population living in MC polluted areas. PMID:25014902

  15. Long-term post-fire effects on spatial ecology and reproductive output of female Agassiz’s desert tortoises (Gopherus agassizii) at a wind energy facility near Palm Springs, California, USA

    USGS Publications Warehouse

    Lovich, Jeffrey E.; Ennen, Joshua R.; Madrak, Sheila V.; Loughran, Caleb L.; Meyer, Katherin P.; Arundel, Terence R.; Bjurlin, Curtis D.

    2011-01-01

    We studied the long-term response of a cohort of eight female Agassiz’s desert tortoises (Gopherus agassizii) during the first 15 years following a large fire at a wind energy generation facility near Palm Springs, California, USA. The fire burned a significant portion of the study site in 1995. Tortoise activity areas were mapped using minimum convex polygons for a proximate post-fire interval from 1997 to 2000, and a long-term post-fire interval from 2009 to 2010. In addition, we measured the annual reproductive output of eggs each year and monitored the body condition of tortoises over time. One adult female tortoise was killed by the fire and five tortoises bore exposure scars that were not fatal. Despite predictions that tortoises would make the short-distance movements from burned to nearby unburned habitats, most activity areas and their centroids remained in burned areas for the duration of the study. The percentage of activity area burned did not differ significantly between the two monitoring periods. Annual reproductive output and measures of body condition remained statistically similar throughout the monitoring period. Despite changes in plant composition, conditions at this site appeared to be suitable for survival of tortoises following a major fire. High productivity at the site may have buffered tortoises from the adverse impacts of fire if they were not killed outright. Tortoise populations at less productive desert sites may not have adequate resources to sustain normal activity areas, reproductive output, and body conditions following fire.

  16. Risk factors that affect reproductive target achievement in fertile dairy cows.

    PubMed

    Aungier, S P M; Roche, J F; Diskin, M G; Crowe, M A

    2014-01-01

    The aims of the present study were to investigate (1) the risk factors that influence the achievement of reproductive targets postpartum (pp) and (2) the key factors that influence pregnancy rate following first artificial insemination (AI) in dairy cows. Ninety-eight Holstein-Friesian pp cows were blood sampled from wk 1 to 4 pp for hematology and biochemistry. Reproductive tract health was assessed weekly by ultrasonography and vaginal mucus scoring. Body condition score (BCS), lameness score, and milk yield were assessed every 2 wk. Milk samples for progesterone assay were collected twice weekly and on d 4, 5, and 7 after AI. Risk factors associated with achieving reproductive targets depended on (1) increased metabolic activity of the liver (increased glutamate dehydrogenase at calving and increased γ-glutamyl transpeptidase in wk 4), (2) a competent immune system (increased neutrophils in wk 1; decreased α1-acid glycoprotein in wk 1, 2, and 3), (3) an endocrine system that was capable of responding by producing sufficient triiodothyronine in wk 2 and increased insulin-like growth factor I in wk 3 and 4, (4) a lower negative energy balance status (decreased nonesterified fatty acid concentration in wk 1; decreased β-hydroxybutyrate concentration in wk 2; BCS loss between calving and d 28 pp <0.5), (5) good reproductive tract health [normal uterine scan at d 45 pp; clear vaginal mucus discharge at first ovulation and at d 45 pp; resumed ovarian cyclicity by the end of the voluntary waiting period (≥ d 35 pp)], and (6) adequate diet (to ensure increased glutathione peroxidase in wk 2 and 3 and increased magnesium in wk 4). Risk factors that increased the odds of a successful first AI were previous ovulation(s) (odds ratio=3.17 per ovulation), BCS >2.5 at AI (odds ratio=3.01), and clear vaginal mucus (score=0) compared with purulent mucus (score >0) 4 d after first AI (odds ratio=2.99). In conclusion, this study identified key risk factors in the early pp

  17. A Single Hot Event That Does Not Affect Survival but Decreases Reproduction in the Diamondback Moth, Plutella xylostella

    PubMed Central

    Zhang, Wei; Zhao, Fei; Hoffmann, Ary A.; Ma, Chun-Sen

    2013-01-01

    Extremely hot events (usually involving a few hours at extreme high temperatures in summer) are expected to increase in frequency in temperate regions under global warming. The impact of these events is generally overlooked in insect population prediction, since they are unlikely to cause widespread mortality, however reproduction may be affected by them. In this study, we examined such stress effects in the diamondback moth, Plutella xylostella. We simulated a single extreme hot day (maximum of 40°C lasting for 3, 4 or 5 h) increasingly experienced under field conditions. This event had no detrimental effects on immediate mortality, copulation duration, mating success, longevity or lifetime fecundity, but stressed females produced 21% (after 3 or 4 h) fewer hatched eggs because of a decline in the number and hatching success of eggs laid on the first two days. These negative effects on reproduction were no longer evident in the following days. Male heat exposure led to a similar but smaller effect on fertile egg production, and exposure extended pre-mating period in both sexes. Our results indicate that a single hot day can have detrimental effects on reproduction, particularly through maternal effects on egg hatching, and thereby influence the population dynamics of diamondback moth. PMID:24116081

  18. Subtle reproductive impairment through nitric oxide-mediated mechanisms in sea urchins from an area affected by harmful algal blooms

    NASA Astrophysics Data System (ADS)

    Migliaccio, Oriana; Castellano, Immacolata; di Cioccio, Davide; Tedeschi, Gabriella; Negri, Armando; Cirino, Paola; Romano, Giovanna; Zingone, Adriana; Palumbo, Anna

    2016-05-01

    The health of the sea urchin Paracentrotus lividus, a key species in the Mediterranean Sea, is menaced by several pressures in coastal environments. Here, we aimed at assessing the reproductive ability of apparently healthy P. lividus population in a marine protected area affected by toxic blooms of Ostreospsis cf. ovata. Wide-ranging analyses were performed in animals collected prior to and during the bloom, as well as at several times thereafter, during the reproductive season. Adults showed a low fertilization rate, along with high nitric oxide (NO) levels in the gonads and the nitration of the major yolk protein toposome, which is an important player in sea urchin development. Serious developmental anomalies were observed in the progeny, which persist several months after the bloom. NO levels were high in the different developmental stages, which also showed variations in the transcription of several genes that were found to be directly or indirectly modulated by NO. These results highlight subtle but important reproductive flaws transmitted from the female gonads to the offspring with the NO involvement. Despite a recovery along time after the bloom, insidious damages can be envisaged in the local sea urchin population, with possible reverberation on the whole benthic system.

  19. Subtle reproductive impairment through nitric oxide-mediated mechanisms in sea urchins from an area affected by harmful algal blooms.

    PubMed

    Migliaccio, Oriana; Castellano, Immacolata; Di Cioccio, Davide; Tedeschi, Gabriella; Negri, Armando; Cirino, Paola; Romano, Giovanna; Zingone, Adriana; Palumbo, Anna

    2016-01-01

    The health of the sea urchin Paracentrotus lividus, a key species in the Mediterranean Sea, is menaced by several pressures in coastal environments. Here, we aimed at assessing the reproductive ability of apparently healthy P. lividus population in a marine protected area affected by toxic blooms of Ostreospsis cf. ovata. Wide-ranging analyses were performed in animals collected prior to and during the bloom, as well as at several times thereafter, during the reproductive season. Adults showed a low fertilization rate, along with high nitric oxide (NO) levels in the gonads and the nitration of the major yolk protein toposome, which is an important player in sea urchin development. Serious developmental anomalies were observed in the progeny, which persist several months after the bloom. NO levels were high in the different developmental stages, which also showed variations in the transcription of several genes that were found to be directly or indirectly modulated by NO. These results highlight subtle but important reproductive flaws transmitted from the female gonads to the offspring with the NO involvement. Despite a recovery along time after the bloom, insidious damages can be envisaged in the local sea urchin population, with possible reverberation on the whole benthic system. PMID:27192939

  20. Subtle reproductive impairment through nitric oxide-mediated mechanisms in sea urchins from an area affected by harmful algal blooms

    PubMed Central

    Migliaccio, Oriana; Castellano, Immacolata; Di Cioccio, Davide; Tedeschi, Gabriella; Negri, Armando; Cirino, Paola; Romano, Giovanna; Zingone, Adriana; Palumbo, Anna

    2016-01-01

    The health of the sea urchin Paracentrotus lividus, a key species in the Mediterranean Sea, is menaced by several pressures in coastal environments. Here, we aimed at assessing the reproductive ability of apparently healthy P. lividus population in a marine protected area affected by toxic blooms of Ostreospsis cf. ovata. Wide-ranging analyses were performed in animals collected prior to and during the bloom, as well as at several times thereafter, during the reproductive season. Adults showed a low fertilization rate, along with high nitric oxide (NO) levels in the gonads and the nitration of the major yolk protein toposome, which is an important player in sea urchin development. Serious developmental anomalies were observed in the progeny, which persist several months after the bloom. NO levels were high in the different developmental stages, which also showed variations in the transcription of several genes that were found to be directly or indirectly modulated by NO. These results highlight subtle but important reproductive flaws transmitted from the female gonads to the offspring with the NO involvement. Despite a recovery along time after the bloom, insidious damages can be envisaged in the local sea urchin population, with possible reverberation on the whole benthic system. PMID:27192939

  1. Honey Bee (Apis mellifera) Queen Reproductive Potential Affects Queen Mandibular Gland Pheromone Composition and Worker Retinue Response.

    PubMed

    Rangel, Juliana; Böröczky, Katalin; Schal, Coby; Tarpy, David R

    2016-01-01

    Reproductive division of labor is one of the defining traits of honey bees (Apis mellifera), with non-reproductive tasks being performed by workers while a single queen normally monopolizes reproduction. The decentralized organization of a honey bee colony is maintained in large part by a bouquet of queen-produced pheromones, the distribution of which is facilitated by contact among workers throughout the hive. Previous studies have shown that the developmental fate of honey bee queens is highly plastic, with queens raised from younger worker larvae exhibiting higher measures of reproductive potential compared to queens raised from older worker larvae. We investigated differences in the chemical composition of the mandibular glands and attractiveness to workers of "high-quality" queens (i.e., raised from first instar worker larvae; more queen-like) and "low-quality" queens (i.e., raised from third instar worker larvae; more worker-like). We characterized the chemical profiles of the mandibular glands of high-quality queens and low-quality queens using GC-MS and used the worker retinue response as a measure of the attractiveness to workers of high-quality queens vs. low-quality queens. We found that queen quality affected the chemical profiles of mandibular gland contents differently across years, showing significant differences in the production of the queen mandibular pheromone ("QMP") components HVA and 9-HDA in 2010, but no significant differences of any glandular compound in 2012. We also found that workers were significantly more attracted to high-quality queens than to low-quality queens in 2012, possibly because of increased attractiveness of their mandibular gland chemical profiles. Our results indicate that the age at which honey bee larvae enter the "queen-specific" developmental pathway influences the chemical composition of queen mandibular glands and worker behavior. However, these changes are not consistent across years, suggesting that other external

  2. Honey Bee (Apis mellifera) Queen Reproductive Potential Affects Queen Mandibular Gland Pheromone Composition and Worker Retinue Response

    PubMed Central

    Böröczky, Katalin; Schal, Coby; Tarpy, David R.

    2016-01-01

    Reproductive division of labor is one of the defining traits of honey bees (Apis mellifera), with non-reproductive tasks being performed by workers while a single queen normally monopolizes reproduction. The decentralized organization of a honey bee colony is maintained in large part by a bouquet of queen-produced pheromones, the distribution of which is facilitated by contact among workers throughout the hive. Previous studies have shown that the developmental fate of honey bee queens is highly plastic, with queens raised from younger worker larvae exhibiting higher measures of reproductive potential compared to queens raised from older worker larvae. We investigated differences in the chemical composition of the mandibular glands and attractiveness to workers of “high-quality” queens (i.e., raised from first instar worker larvae; more queen-like) and “low-quality” queens (i.e., raised from third instar worker larvae; more worker-like). We characterized the chemical profiles of the mandibular glands of high-quality queens and low-quality queens using GC-MS and used the worker retinue response as a measure of the attractiveness to workers of high-quality queens vs. low-quality queens. We found that queen quality affected the chemical profiles of mandibular gland contents differently across years, showing significant differences in the production of the queen mandibular pheromone (“QMP”) components HVA and 9-HDA in 2010, but no significant differences of any glandular compound in 2012. We also found that workers were significantly more attracted to high-quality queens than to low-quality queens in 2012, possibly because of increased attractiveness of their mandibular gland chemical profiles. Our results indicate that the age at which honey bee larvae enter the “queen-specific” developmental pathway influences the chemical composition of queen mandibular glands and worker behavior. However, these changes are not consistent across years, suggesting

  3. Factors affecting the reproductive success of American Oystercatchers Haematopus palliatus on the outer banks of North Carolina

    USGS Publications Warehouse

    Schulte, Shiloh A.; Simons, Theodore R.

    2015-01-01

    We used an information-theoretic approach to assess the factors affecting the reproductive success of American Oystercatchers Haematopus palliatus on the Outer Banks of North Carolina. We evaluated survival with respect to nesting island, year, time of season, brood age, distance to tide (m), presence of off-road vehicles and proximity of foraging habitat. The daily nest survival (mean 0.981, standard error [SE] 0.002) was affected by year and island, and declined over the nesting season. Mammals were responsible for 54% of identified nest failures. Daily brood survival (mean 0.981, SE 0.002) varied by island and increased non-linearly with age, with highest mortality in the seven days after hatching. Model results indicate direct access to foraging sites has a positive effect on brood survival, whereas presence of off-road vehicles has a negative effect. We studied chick behavior and survival using radio telemetry and direct observation and found that vehicles caused mortality and affected behavior and resource use by oystercatcher chicks. We identified the source of mortality for 37 radio-tagged chicks. Six (16%) were killed by vehicles, 21 (57%) by predators, and 10 (27%) by exposure and starvation. From 1995 to 2008, 25 additional oystercatcher chicks were found dead, 13 (52%) killed by vehicles. Chicks on beaches closed to vehicles used beach and intertidal zones more frequently than chicks on beaches open to vehicles. Chick predators included Great Horned Owls Bubo virginianus, Fish Crows Corvus ossifragus, cats Felis catus, mink Mustela vison, raccoons Procyon lotor, and ghost crabs Ocypode albicans. The factors affecting reproductive success differed between the incubation and chick-rearing stages.  Management actions that influence chick survival will have a larger effect on total productivity than actions affecting nest survival.

  4. Sodium fluoride and sulfur dioxide affected male reproduction by disturbing blood-testis barrier in mice.

    PubMed

    Zhang, Jianhai; Li, Zhihui; Qie, Mingli; Zheng, Ruibo; Shetty, Jagathpala; Wang, Jundong

    2016-08-01

    Fluoride and sulfur dioxide (SO2), two well-known environmental toxicants, have been implicated to have adverse effects on male reproductive health in humans and animals. The objective of this study to investigate if the BTB is one of the pathways that lead to reproductive toxicity of sodium fluoride and sulfur dioxide alone or in combination, in view of the key role of blood testis barrier (BTB) in testis. The results showed that a marked decrease in sperm quality, and altered morphology and ultrastructure of BTB in testis of mice exposure to fluoride (100 mg NaF/L in drinking water) or/and sulfur dioxide (28 mg SO2/m(3), 3 h/day). Meanwhile, the mRNA expression levels of some vital BTB-associated proteins, including occluding, claudin-11, ZO-1, Ncadherin, α-catenin, and connexin-43 were all strikingly reduced after NaF exposure, although only the reduction of DSG-2 was statistically significant in all treatment groups. Moreover, the proteins expressions also decreased significantly in claudin-11, N-cadherin, α-catenin, connexin-43 and desmoglein-2 in mice treated with fluoride and/or SO2. These changes in BTB structure and constitutive proteins may therefore be connected with the low sperm quality in these mice. The role of fluoride should deserves more attention in this process. PMID:27237588

  5. Alloparenting experience affects future parental behavior and reproductive success in prairie voles (Microtus ochrogaster).

    PubMed

    Stone, Anita Iyengar; Mathieu, Denise; Griffin, Luana; Bales, Karen Lisa

    2010-01-01

    Various hypotheses have been proposed to explain the function of alloparental behavior in cooperatively breeding species. We examined whether alloparental experience as juveniles enhanced later parental care and reproductive success in the prairie vole (Microtus ochrogaster), a cooperatively breeding rodent. Juveniles cared for one litter of siblings (1EX), two litters of siblings (2EX) or no siblings (0EX). As adults, these individuals were mated to other 0EX, 1EX or 2EX voles, yielding seven different pair combinations, and we recorded measures of parental behaviors, reproductive success, and pup development. As juveniles, individuals caring for siblings for the first time were more alloparental; and as adults, 0EX females paired with 0EX males spent more time in the nest with their pups. Taken together, these results suggest that inexperienced animals spend more time in infant care. As parents, 1EX males spent more time licking their pups than 2EX and 0EX males. Pups with either a 1EX or 2EX parent gained weight faster than pups with 0EX parents during certain developmental periods. While inexperienced animals may spend more time in pup care, long-term benefits of alloparenting may become apparent in the display of certain, particularly important parental behaviors such as licking pups, and in faster weight gain of offspring. PMID:19732810

  6. DESTAF: a database of text-mined associations for reproductive toxins potentially affecting human fertility.

    PubMed

    Dawe, Adam S; Radovanovic, Aleksandar; Kaur, Mandeep; Sagar, Sunil; Seshadri, Sundararajan V; Schaefer, Ulf; Kamau, Allan A; Christoffels, Alan; Bajic, Vladimir B

    2012-01-01

    The Dragon Exploration System for Toxicants and Fertility (DESTAF) is a publicly available resource which enables researchers to efficiently explore both known and potentially novel information and associations in the field of reproductive toxicology. To create DESTAF we used data from the literature (including over 10500 PubMed abstracts), several publicly available biomedical repositories, and specialized, curated dictionaries. DESTAF has an interface designed to facilitate rapid assessment of the key associations between relevant concepts, allowing for a more in-depth exploration of information based on different gene/protein-, enzyme/metabolite-, toxin/chemical-, disease- or anatomically centric perspectives. As a special feature, DESTAF allows for the creation and initial testing of potentially new association hypotheses that suggest links between biological entities identified through the database. DESTAF, along with a PDF manual, can be found at http://cbrc.kaust.edu.sa/destaf. It is free to academic and non-commercial users and will be updated quarterly. PMID:22198179

  7. Reproductive traits affect the rescue of valuable and endangered multipurpose tropical trees.

    PubMed

    Sinébou, Viviane; Quinet, Muriel; Ahohuendo, Bonaventure C; Jacquemart, Anne-Laure

    2016-01-01

    Conservation strategies are urgently needed in Tropical areas for widely used tree species. Increasing numbers of species are threatened by overexploitation and their recovery might be poor due to low reproductive success and poor regeneration rates. One of the first steps in developing any conservation policy should be an assessment of the reproductive biology of species that are threatened by overexploitation. This work aimed to study the flowering biology, pollination and breeding system of V. doniana, a multipurpose threatened African tree, as one step in assessing the development of successful conservation strategies. To this end, we studied (1) traits directly involved in pollinator attraction like flowering phenology, flower numbers and morphology, and floral rewards; (2) abundance, diversity and efficiency of flower visitors; (3) breeding system, through controlled hand-pollination experiments involving exclusion of pollinators and pollen from different sources; and (4) optimal conditions for seed germination. The flowering phenology was asynchronous among inflorescences, trees and sites. The flowers produced a large quantity of pollen and nectar with high sugar content. Flowers attracted diverse and abundant visitors, counting both insects and birds, and efficient pollinators included several Hymenoptera species. We detected no spontaneous self-pollination, indicating a total dependence on pollen vectors. Vitex doniana is self-compatible and no inbreeding depression occurred in the first developmental stages. After extraction of the seed from the fruit, seed germination did not require any particular conditions or pre-treatments and the seeds showed high germination rates. These pollination and breeding characteristics as well as germination potential offer the required conditions to develop successful conservation strategies. Protection, cultivation and integration in agroforestry systems are required to improve the regeneration of the tree. PMID:27354660

  8. Reproductive traits affect the rescue of valuable and endangered multipurpose tropical trees

    PubMed Central

    Sinébou, Viviane; Quinet, Muriel; Ahohuendo, Bonaventure C.; Jacquemart, Anne-Laure

    2016-01-01

    Conservation strategies are urgently needed in Tropical areas for widely used tree species. Increasing numbers of species are threatened by overexploitation and their recovery might be poor due to low reproductive success and poor regeneration rates. One of the first steps in developing any conservation policy should be an assessment of the reproductive biology of species that are threatened by overexploitation. This work aimed to study the flowering biology, pollination and breeding system of V. doniana, a multipurpose threatened African tree, as one step in assessing the development of successful conservation strategies. To this end, we studied (1) traits directly involved in pollinator attraction like flowering phenology, flower numbers and morphology, and floral rewards; (2) abundance, diversity and efficiency of flower visitors; (3) breeding system, through controlled hand-pollination experiments involving exclusion of pollinators and pollen from different sources; and (4) optimal conditions for seed germination. The flowering phenology was asynchronous among inflorescences, trees and sites. The flowers produced a large quantity of pollen and nectar with high sugar content. Flowers attracted diverse and abundant visitors, counting both insects and birds, and efficient pollinators included several Hymenoptera species. We detected no spontaneous self-pollination, indicating a total dependence on pollen vectors. Vitex doniana is self-compatible and no inbreeding depression occurred in the first developmental stages. After extraction of the seed from the fruit, seed germination did not require any particular conditions or pre-treatments and the seeds showed high germination rates. These pollination and breeding characteristics as well as germination potential offer the required conditions to develop successful conservation strategies. Protection, cultivation and integration in agroforestry systems are required to improve the regeneration of the tree. PMID:27354660

  9. Gonadal steroids and affective symptoms during in vitro fertilization: implication for reproductive mood disorders.

    PubMed

    Bloch, Miki; Aharonov, Inbar; Ben Avi, Irit; Schreiber, Shaul; Amit, Ami; Weizman, Abraham; Azem, Foad

    2011-07-01

    Gonadal steroids (GSs) have been associated with the onset of a number of reproductive-related mood disorders in women, in which fluctuating or unstable hormonal levels are postulated to act as the trigger for the destabilization of mood. There is, however, rather limited direct clinical evidence that can link rapidly changing GS levels with the induction of mood symptoms. We aimed to study the effect of controlled and rapid GS fluctuations on mood in an in vivo model. Women undergoing in vitro fertilization (n=108) were assessed for depression and anxiety levels on 3 time points: during a low estradiol and progesterone baseline, during a gonadotropin stimulated estradiol-dominant phase, and after embryo transfer, during a progesterone-dominant low estrogen phase. Plasma levels for estrogen and progesterone were drawn on these time points. Symptoms of depression and anxiety significantly increased from baseline to the high estradiol levels but were not correlated with estrogen. The sharp drop from high estradiol levels at the estradiol-dominant phase to low levels at the progesterone-dominant phase was significantly correlated with rising depression scores. The rise in progesterone levels from low levels at the estradiol-dominant phase to high levels at the progesterone-dominant phase was significantly and inversely correlated with depression scores. This study suggests that the mechanism underlying the role of estrogen in reproductive-related mood disorders involves an abrupt and precipitous drop in its plasma level that can precipitate negative mood states. This finding has implications on the treatment of GS-related mood disorders. PMID:21106297

  10. COULD ETHINYL ESTRADIOL AFFECT THE POPULATION BIOLOGY OF CUNNER, TAUTOGOLABRUS ADSPERSUS

    EPA Science Inventory

    Endocrine disrupting chemicals in the environment may disturb the population dynamics of wildlife by affecting reproductive output and embryonic development of organisms. This study used a population model to evaluate whether ethinyl estradiol (EE2 could affect cunner Tautogolabr...

  11. Key Factors Affecting Reproductive Success of Thoroughbred Mares and Stallions on a Commercial Stud Farm.

    PubMed

    Lane, E A; Bijnen, Mlj; Osborne, M; More, S J; Henderson, Isf; Duffy, P; Crowe, M A

    2016-04-01

    To evaluate factors contributing to fertility of thoroughbred mares, data from 3743 oestrous periods of 2385 mares were collected on a large thoroughbred farm in Ireland. Fourteen stallions (mean age 8.3 years; range 4-15 years) had bred 2385 mares (mean age 9.4 years; range 3-24 years). Maiden mares accounted for 12%, mares with a foal at foot for 64%, and barren, slipped or rested mares for 24% of the total. The mean pregnancy rate per cycle was 67.8% (68.6% in year 1 and 66.9% in year 2). Backward stepwise multivariable logistic regression analysis was utilized to develop two models to evaluate mare factors, including mare age, reproductive status, month of foaling, dystocia, month of cover, foal heat, cycle number, treatments, walk-in status and stallion factors including stallion identity, stallion age, shuttle status, time elapsed between covers and high stallion usage on the per cycle pregnancy rate and pregnancy loss. Old age (p < 0.001) and cover within 20 days post-partum (p < 0.003) were associated with lowered pregnancy rates. High mare age (p < 0.05) and barren, slipped or rested reproductive status (p = 0.05) increased the likelihood of pregnancy loss. Uterine inflammation or infection, if appropriately treated, did not affect fertility. Only high usage of stallions (used more than 21 times in previous week) was associated with lowered (p = 0.009) pregnancy rates. However, shuttle stallions were more likely to have increased (p = 0.035) pregnancy survival, perhaps reflecting a bias in stallion selection. In conclusion, mare age exerted the greatest influence on fertility; nonetheless, thoroughbreds can be effectively managed to achieve high reproductive performance in a commercial setting. PMID:26815482

  12. CO2, Temperature, and Soil Moisture Interactions Affect NDVI and Reproductive Phenology in Old-Field Plant Communities

    NASA Astrophysics Data System (ADS)

    Engel, C.; Weltzin, J.; Norby, R.

    2004-12-01

    Plant community composition and ecosystem function may be altered by global atmospheric and climate change, including increased atmospheric [CO2], temperature, and varying precipitation regimes. We are conducting an experiment at Oak Ridge National Laboratory (ORNL) utilizing open-top chambers to administer experimental treatments of elevated CO2 (+300 ppm), warming (+ 3 degrees Celsius), and varying soil moisture availability to experimental plant communities constructed of seven common old-field species, including C3 and C4 grasses, forbs, and legumes. During 2004 we monitored plant community phenology (NDVI) and plant reproductive phenology. Early in the year, NDVI was greater in wet treatment plots, and was unaffected by main effects of temperature or CO2. This result suggests that early in the season warming is insufficient to affect early canopy development. Differences in soil moisture sustained throughout the winter and into early spring may constitute an important control on early canopy greenup. Elevated CO2 alleviated detrimental effects of warming on NDVI, but only early in the season. As ambient temperatures increased, elevated temperatures negatively impacted NDVI only in the dry plots. Wetter conditions ameliorate the effects of warming on canopy greenness during the warmer seasons of the year. Warming increased rates of bolting, number of inflorescences, and time to reproductive maturity for Andropogon virginicus (a C4 bunchgrass). Solidago Canadensis (a C3 late-season forb) also produced flowers earlier in elevated temperatures. Conversely, none of the C3 grasses and forbs that bolt or flower in late spring or early summer responded to temperature or CO2. Results indicate that warming and drought may impact plant community phenology, and plant species reproductive phenology. Clearly community phenology is driven by complex interactions among temperature, water, and CO2 that change throughout the season. Our data stresses the importance of

  13. Maternally transferred dioxin-like compounds can affect the reproductive success of European eel.

    PubMed

    Foekema, Edwin M; Kotterman, Michiel; de Vries, Pepijn; Murk, Albertinka J

    2016-01-01

    Reported concentrations of dioxin-like compounds accumulated in the European eel (Anguilla anguilla) were used to perform a risk assessment for eel larval survival, taking into account a modeled amplification of tissue concentrations with a factor of 1.33 during spawning migration. The calculated concentrations of dioxin-like compounds finally deposited in the eggs were compared with the internal effect concentrations for survival of early life stages of the European eel; these concentrations, by lack of experimental data, were estimated from a sensitivity distribution based on literature data by assuming that eel larvae are among the 10% most sensitive teleost fish species. Given concentrations of dioxin-like contaminants and assuming a relatively high sensitivity, it can be expected that larvae from eggs produced by eel from highly contaminated locations in Europe will experience increased mortality as a result of maternally transferred dioxin-like contaminants. As historical persistent organic pollutant concentrations in eel tissue were higher, this impact must have been stronger in the past. Potential effects of other compounds or effects on the migration, condition, and fertility of the parental animals were not taken into account. It is important to further study the overall impact of contaminants on the reproductive success of the European eel as this may have been underestimated until now. PMID:26223357

  14. Nanoplastic affects growth of S. obliquus and reproduction of D. magna.

    PubMed

    Besseling, Ellen; Wang, Bo; Lürling, Miquel; Koelmans, Albert A

    2014-10-21

    The amount of nano- and microplastic in the aquatic environment rises due to the industrial production of plastic and the degradation of plastic into smaller particles. Concerns have been raised about their incorporation into food webs. Little is known about the fate and effects of nanoplastic, especially for the freshwater environment. In this study, effects of nano-polystyrene (nano-PS) on the growth and photosynthesis of the green alga Scenedesmus obliquus and the growth, mortality, neonate production, and malformations of the zooplankter Daphnia magna were assessed. Nano-PS reduced population growth and reduced chlorophyll concentrations in the algae. Exposed Daphnia showed a reduced body size and severe alterations in reproduction. Numbers and body size of neonates were lower, while the number of neonate malformations among neonates rose to 68% of the individuals. These effects of nano-PS were observed between 0.22 and 103 mg nano-PS/L. Malformations occurred from 30 mg of nano-PS/L onward. Such plastic concentrations are much higher than presently reported for marine waters as well as freshwater, but may eventually occur in sediment pore waters. As far as we know, these results are the first to show that direct life history shifts in algae and Daphnia populations may occur as a result of exposure to nanoplastic. PMID:25268330

  15. An investigation into the factors affecting the natural reproduction of Opsaridium peringueyi

    NASA Astrophysics Data System (ADS)

    Moyo, N. A. G.

    An endangered freshwater fish, Opsaridium peringueyi, was studied from January, 2009 to December, 2009. The analysis of the environmental conditions indicated that the fish is found in streams with moderate to fast flow, high oxygen levels, a depth greater than 0.6 m and temperatures between 10 and 24 °C. O. peringueyi is sexually dimorphic with males growing at a faster rate and attaining a larger size than females. The breeding biology of this species was investigated in glass aquarium tanks. The spawning behaviour is described for the first time. The breeding colour of the male is deep red on the operculum, ventral part, caudal and ventral fins. The breeding colour in the female is the same as the male except the red colour is lighter. The breeding of O. peringueyi is a four stage process which begins with the appearance of breeding colour culminating in the laying of eggs after courtship. Temperature, flow-rate, conductivity and substrate were identified as the environmental cues important in the reproduction of this species. All these factors had a significant effect on the breeding activity of O. peringueyi. The possible effect of climate change on O. peringueyi is discussed.

  16. Breath carbon monoxide output is affected by speed of emptying the lungs: Implications for laboratory and smoking cessation research

    PubMed Central

    Faix, Crystal; Turturici, Marissa; Dallery, Jesse

    2010-01-01

    Introduction: Researchers have used breath carbon monoxide (CO) cutoff values ranging from 4 to 10 ppm to define abstinence in cigarette-smoking cessation research and reductions in CO as a measure of acute abstinence in laboratory research. The current study used a reversal design to investigate effects of exhalation speed on CO output in four groups (non-, light, moderate, and heavy smokers; n = 20 per group). Methods: In one condition, participants were instructed to empty their lungs as quickly as possible (fast), whereas in a different condition, participants were instructed to empty their lungs at a slow pace (slow). Conditions were counterbalanced and repeated twice for each participant. Results: For all groups, speed of exhalation was significantly lower during the slow condition than during the fast condition, and CO output was significantly higher during the slow condition than during the fast condition. Sensitivity and specificity analyses revealed that the optimal CO cutoff for smoking abstinence was 3 ppm during the fast condition versus 4 ppm during the slow condition. Additionally, when heavy smokers switched from exhaling slow to exhaling fast, they showed an approximately 30% reduction in CO. Discussion: The results suggest that exhalation speed should be monitored when CO is used as a measure of smoking status for laboratory and smoking cessation research. If exhalation speed is not monitored when using CO to verify smoking cessation, then more conservative CO cutoff values should be used to avoid false negative CO readings. PMID:20530193

  17. Developmental methoxychlor exposure affects multiple reproductive parameters and ovarian folliculogenesis and gene expression in adult rats

    SciTech Connect

    Armenti, AnnMarie E.; Zama, Aparna Mahakali; Passantino, Lisa; Uzumcu, Mehmet

    2008-12-01

    Methoxychlor (MXC) is an organochlorine pesticide with estrogenic, anti-estrogenic, and anti-androgenic properties. To investigate whether transient developmental exposure to MXC could cause adult ovarian dysfunction, we exposed Fischer rats to 20 {mu}g/kg/day (low dose; environmentally relevant dose) or 100 mg/kg/day (high dose) MXC between 19 days post coitum and postnatal day 7. Multiple reproductive parameters, serum hormone levels, and ovarian morphology and molecular markers were examined from prepubertal through adult stages. High dose MXC accelerated pubertal onset and first estrus, reduced litter size, and increased irregular cyclicity (P < 0.05). MXC reduced superovulatory response to exogenous gonadotropins in prepubertal females (P < 0.05). Rats exposed to high dose MXC had increasing irregular estrous cyclicity beginning at 4 months of age, with all animals showing abnormal cycles by 6 months. High dose MXC reduced serum progesterone, but increased luteinizing hormone (LH). Follicular composition analysis revealed an increase in the percentage of preantral and early antral follicles and a reduction in the percentage of corpora lutea in high dose MXC-treated ovaries (P < 0.05). Immunohistochemical staining and quantification of the staining intensity showed that estrogen receptor {beta} was reduced by high dose MXC while anti-Mullerian hormone was upregulated by both low- and high dose MXC in preantral and early antral follicles (P < 0.05). High dose MXC significantly reduced LH receptor expression in large antral follicles (P < 0.01), and down-regulated cytochrome P450 side-chain cleavage. These results demonstrated that developmental MXC exposure results in reduced ovulation and fertility and premature aging, possibly by altering ovarian gene expression and folliculogenesis.

  18. The binary mixtures of megestrol acetate and 17α-ethynylestradiol adversely affect zebrafish reproduction.

    PubMed

    Hua, Jianghuan; Han, Jian; Wang, Xianfeng; Guo, Yongyong; Zhou, Bingsheng

    2016-06-01

    Synthetic progesterones and estrogens are broadly used bioactive pharmaceutical agents and have been detected in aquatic environments. In the present study, we investigated the combined reproductive effects of megestrol acetate (MTA) and 17α-ethinylestradiol (EE2) on zebrafish. Adult zebrafish were exposed to MTA (33, 100 or 333 ng/L), EE2 (10 ng/L) or a mixture of both (MTA + EE2: 33 + 10, 100 + 10 or 333 + 10 ng/L) for 21 days. Results demonstrated that egg production was significantly reduced by exposure to 10 ng/L EE2, but not MTA. However, a combined exposure to MTA and EE2 caused further reduction of fish fecundity compared to EE2 exposure alone, suggesting an additive effect on egg production when EE2 is supplemented with MTA. Plasma concentrations of 17β-estradiol and testosterone in the females and 11-ketotestosterone in the males were significantly decreased in the groups exposed to EE2 or MTA alone compared with the solvent control, and the plasma concentrations of the three hormones were further reduced in the co-exposure groups relative to the MTA exposure group, but not the EE2 exposure group. These data indicate that the inhibitory effects on plasma concentrations in the co-exposures were predominantly caused by EE2. Furthermore, exposure to MTA and EE2 (alone or in combination) led to histological alterations in the ovaries (decreased vitellogenic/mature oocytes), but not in the testes. This study has important implications for environmental risk assessment of synthetic hormones that are concurrently present in aquatic systems. PMID:27038209

  19. Developmental Methoxychlor Exposure Affects Multiple Reproductive Parameters and Ovarian: Folliculogenesis and Gene Expression in Adult Rats

    PubMed Central

    Armenti, AnnMarie E.; Zama, Aparna Mahakali; Passantino, Lisa; Uzumcu, Mehmet

    2008-01-01

    Methoxychlor (MXC) is an organochlorine pesticide with estrogenic, anti-estrogenic, and anti-androgenic properties. To investigate whether transient developmental exposure to MXC could cause adult ovarian dysfunction, we exposed Fischer rats to 20 μg/kg/day (low dose; environmentally relevant dose) or 100 mg/kg/day (high dose) MXC between 19 days post-coitum and postnatal day 7. Multiple reproductive parameters, serum hormone levels, and ovarian morphology and molecular markers were examined from prepubertal through adult stages. High dose MXC accelerated pubertal onset and first estrus, reduced litter size, and increased irregular cyclicity (P < 0.05). MXC reduced superovulatory response to exogenous gonadotropins in prepubertal females (P < 0.05). Rats exposed to high dose MXC had increasing irregular estrous cyclicity beginning at 4 months of age, with all animals showing abnormal cycles by 6 months. High dose MXC reduced serum progesterone, but increased luteinizing hormone (LH). Follicular composition analysis revealed an increase in the percentage of preantral and early antral follicles and a reduction in the percentage of corpora lutea in high dose MXC-treated ovaries (P < 0.05). Immunohistochemical staining and quantification of the staining intensity showed that estrogen receptor β was reduced by high dose MXC while anti-Mullerian hormone was upregulated by both low- and high dose MXC in preantral and early antral follicles (P < 0.05). High dose MXC significantly reduced LH receptor expression in large antral follicles (P < 0.01), and down-regulated cytochrome P450 side-chain cleavage. These results demonstrated that developmental MXC exposure results in reduced ovulation and fertility and premature aging, possibly by altering ovarian gene expression and folliculogenesis. PMID:18848953

  20. Acute exposure to gas-supersaturated water does not affect reproductive success of female adult chinook salmon late in maturation

    USGS Publications Warehouse

    Gale, William L.; Maule, A.G.; Postera, A.; Peters, M.H.

    2004-01-01

    At times, total dissolved gas concentrations in the Columbia and Snake rivers have been elevated due to involuntary spill from high spring runoff and voluntary spill used as a method to pass juvenile salmonids over dams. The goal of this project was to determine if acute exposure to total dissolved gas supersaturation (TDGS) affects the reproductive performance of female chinook salmon late in their maturation. During this study, adult female spring chinook salmon were exposed to mean TDGS levels of 114.1 % to 125.5%. We ended exposures at first mortality, or at the appearance of impending death. Based on this criterion, exposures lasted from 10 to 68 h and were inversely related to TDGS. There was no effect of TDGS on pre-spawning mortality or fecundity when comparing treatment fish to experimental controls or the general hatchery population four to six weeks after exposures. Egg quality, based on egg weight and egg diameter, did not differ between treatment and control fish. Fertilization rate and survival to eyed-stage was high (>94%) for all groups. With the exception of Renibacterium salmoninarum (the causative agent of bacterial kidney disease; BKD), no viral or bacterial fish pathogens were isolated from experimental fish. The prevalence (about 45%) and severity of R. salmoninarum did not differ among the groups or the general hatchery population. We conclude that these acute exposures to moderate levels of gas-supersaturated water-perhaps similar to that experienced by immigrating adult salmon as they approach and pass a hydropower dam on the Columbia River-did not affect reproductive success of female chinook salmon late in their maturation. These results are most applicable to summer and fall chinook salmon, which migrate in the summer/fall and spawn shortly after reaching their natal streams. Published in 2004 by John Wiley and Sons, Ltd.

  1. Influence of Affective Stimuli on Leg Power Output and Associated Neuromuscular Parameters during Repeated High Intensity Cycling Exercises

    PubMed Central

    Jaafar, Hamdi; Rouis, Majdi; Coudrat, Laure; Gélat, Thierry; Noakes, Timothy David; Driss, Tarak

    2015-01-01

    The aim of this study was to examine the impact of emotional eliciting pictures on neuromuscular performance during repetitive supramaximal cycling exercises (RSE). In a randomized order, twelve male participants were asked to perform five 6-s cycle sprints (interspaced by 24 s of recovery) on a cycle ergometer in front of neutral, pleasant or unpleasant pictures. During each RSE, mean power output (MPO) and electromyographic activity [root mean square (RMS) and median frequency (MF)] of the vastus lateralis and vastus medialis muscles were analyzed. Neuromuscular efficiency (NME) was calculated as the ratio of MPO to RMS. Higher RMS (232.17 ± 1.17 vs. 201.90 ± 0.47 μV) and MF (68.56 ± 1.78 vs. 64.18 ± 2.17 Hz) were obtained in pleasant compared to unpleasant conditions (p < 0.05). This emotional effect persisted from the first to the last sprint. Higher MPO was obtained in pleasant than in unpleasant conditions (690.65 ± 38.23 vs. 656.73 ± 35.95 W, p < 0.05). However, this emotional effect on MPO was observed only for the two first sprints. NME decreased from the third sprint (p < 0.05), which indicated the occurrence of peripheral fatigue after the two first sprints. These results suggested that, compared with unpleasant pictures, pleasant ones increased the neuromuscular performance during RSE. Moreover, the disappearance of the beneficial effect of pleasant emotion on mechanical output from the third sprint appears to be due to peripheral fatigue. PMID:26305334

  2. Effect of DDT and MCPA (4-chloro-2-methylphenoxyacetic acid) on reproduction of the pond snail, Lymnaea stagnalis L

    SciTech Connect

    Woin, P.; Broenmark, C. )

    1992-01-01

    Reproduction is the single most important function in the life cycle of an organism. Successful reproduction determines fitness of organisms. The inability of an organism to complete any one stage of the reproductive process severely reduces its lifetime reproductive success. Disruptions in the reproduction will ultimately affect the abundance and distribution of the species. Therefore, laboratory tests of long-term impact of sublethal pollutant concentrations on organisms preferably is done on the reproductive success. Pollutants of diverse structure may affect the reproductive system which is sensitive to toxic agents. Certain pollutants, notably the organochlorine compounds, have been shown to affect the male and female reproductive systems. The authors have studied the effect of sublethal concentrations of DDT and the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) on the reproductive output of the pulmonate snail Lymnaea stagnalis under a 2-mon exposure period.

  3. Sublethal effects of antibiosis resistance on the reproductive biology of two spittlebug (Hemiptera: Cercopidae) species affecting Brachiaria spp.

    PubMed

    Sotelo, Paola A; Miller, María F; Cardona, Cesar; Miles, John W; Sotelo, Guillermo; Montoya, James

    2008-04-01

    Several greenhouse experiments were used to measure how high levels of antibiosis resistance to nymphs in two interspecific Brachiaria (brachiariagrass) hybrids affect life history parameters of the spittlebugs Aeneolamia varia (F.) and Zulia carbonaria (Lallemand), two of the most important spittlebug (Hemiptera: Cercopidae) species affecting Brachiaria production in Colombia. The A. varia-resistant hybrid CIAT 36062, the Z. carbonaria-resistant hybrid SX01NO/0102, and the susceptible accession CIAT 0654 were used to compare the effect of all possible combinations of food sources for nymphs and adults. Calculation of growth indexes showed a significant impact of antibiosis resistance on the biology of immature stages of both species. Median survival times of adults feeding on resistant genotypes did not differ from those recorded on the susceptible genotype, suggesting that factors responsible for high mortality of nymphs in the resistant hybrids did not affect adult survival. Rearing nymphs of A. varia on CIAT 36062 and of Z. carbonaria on SX01NO/0102 had deleterious sublethal effects on the reproductive biology of resulting adult females. It is concluded that high nymphal mortality and subsequent sublethal effects of nymphal antibiosis on adults should have a major impact on the demography of the two spittlebug species studied. PMID:18459425

  4. The concentration of plasma metabolites varies throughout reproduction and affects offspring number in wild brown trout (Salmo trutta).

    PubMed

    Gauthey, Zoé; Freychet, Marine; Manicki, Aurélie; Herman, Alexandre; Lepais, Olivier; Panserat, Stéphane; Elosegi, Arturo; Tentelier, Cédric; Labonne, Jacques

    2015-06-01

    In wild populations, measuring energy invested in the reproduction and disentangling investment in gametes versus investment in reproductive behavior (such as intrasexual competition or intersexual preference) remain challenging. In this study, we investigated the energy expenditure in brown trout reproductive behavior by using two proxies: variation in weight and variation of plasma metabolites involved in energy production, over the course of reproductive season in a semi natural experimental river. We estimated overall reproductive success using genetic assignment at the end of the reproductive season. Results show that triglycerides and free fatty acid concentrations vary negatively during reproduction, while amino-acids and glucose concentrations remain stable. Decrease in triglyceride and free fatty acid concentrations during reproduction is not related to initial concentration levels or to weight variation. Both metabolite concentration variations and weight variations are correlated to the number of offspring produced, which could indicate that gametic and behavioral reproductive investments substantially contribute to reproductive success in wild brown trout. This study opens a path to further investigate variations in reproductive investment in wild populations. PMID:25666363

  5. Reproduction Does Not Adversely Affect Liver Mitochondrial Respiratory Function but Results in Lipid Peroxidation and Increased Antioxidants in House Mice

    PubMed Central

    Mowry, Annelise V.; Kavazis, Andreas N.; Sirman, Aubrey E.; Potts, Wayne K.; Hood, Wendy R.

    2016-01-01

    Reproduction is thought to come at a cost to longevity. Based on the assumption that increased energy expenditure during reproduction is associated with increased free-radical production by mitochondria, oxidative damage has been suggested to drive this trade-off. We examined the impact of reproduction on liver mitochondrial function by utilizing post-reproductive and non-reproductive house mice (Mus musculus) living under semi-natural conditions. The age-matched post-reproductive and non-reproductive groups were compared after the reproductive females returned to a non-reproductive state, so that both groups were in the same physiological state at the time the liver was collected. Despite increased oxidative damage (p = 0.05) and elevated CuZnSOD (p = 0.002) and catalase (p = 0.04) protein levels, reproduction had no negative impacts on the respiratory function of liver mitochondria. Specifically, in a post-reproductive, maintenance state the mitochondrial coupling (i.e., respiratory control ratio) of mouse livers show no negative impacts of reproduction. In fact, there was a trend (p = 0.059) to suggest increased maximal oxygen consumption by liver mitochondria during the ADP stimulated state (i.e., state 3) in post-reproduction. These findings suggest that oxidative damage may not impair mitochondrial respiratory function and question the role of mitochondria in the trade-off between reproduction and longevity. In addition, the findings highlight the importance of quantifying the respiratory function of mitochondria in addition to measuring oxidative damage. PMID:27537547

  6. Phenotypic plasticity in growth and fecundity induced by strong population fluctuations affects reproductive traits of female fish.

    PubMed

    Karjalainen, Juha; Urpanen, Olli; Keskinen, Tapio; Huuskonen, Hannu; Sarvala, Jouko; Valkeajärvi, Pentti; Marjomäki, Timo J

    2016-02-01

    Fish are known for their high phenotypic plasticity in life-history traits in relation to environmental variability, and this is particularly pronounced among salmonids in the Northern Hemisphere. Resource limitation leads to trade-offs in phenotypic plasticity between life-history traits related to the reproduction, growth, and survival of individual fish, which have consequences for the age and size distributions of populations, as well as their dynamics and productivity. We studied the effect of plasticity in growth and fecundity of vendace females on their reproductive traits using a series of long-term incubation experiments. The wild parental fish originated from four separate populations with markedly different densities, and hence naturally induced differences in their growth and fecundity. The energy allocation to somatic tissues and eggs prior to spawning served as a proxy for total resource availability to individual females, and its effects on offspring survival and growth were analyzed. Vendace females allocated a rather constant proportion of available energy to eggs (per body mass) despite different growth patterns depending on the total resources in the different lakes; investment into eggs thus dictated the share remaining for growth. The energy allocation to eggs per mass was higher in young than in old spawners and the egg size and the relative fecundity differed between them: Young females produced more and smaller eggs and larvae than old spawners. In contrast to earlier observations of salmonids, a shortage of maternal food resources did not increase offspring size and survival. Vendace females in sparse populations with ample resources and high growth produced larger eggs and larvae. Vendace accommodate strong population fluctuations by their high plasticity in growth and fecundity, which affect their offspring size and consequently their recruitment and productivity, and account for their persistence and resilience in the face of high

  7. Feather corticosterone reveals effect of moulting conditions in the autumn on subsequent reproductive output and survival in an Arctic migratory bird

    PubMed Central

    Harms, N. Jane; Legagneux, Pierre; Gilchrist, H. Grant; Bêty, Joël; Love, Oliver P.; Forbes, Mark R.; Bortolotti, Gary R.; Soos, Catherine

    2015-01-01

    For birds, unpredictable environments during the energetically stressful times of moulting and breeding are expected to have negative fitness effects. Detecting those effects however, might be difficult if individuals modulate their physiology and/or behaviours in ways to minimize short-term fitness costs. Corticosterone in feathers (CORTf) is thought to provide information on total baseline and stress-induced CORT levels at moulting and is an integrated measure of hypothalamic–pituitary–adrenal activity during the time feathers are grown. We predicted that CORTf levels in northern common eider females would relate to subsequent body condition, reproductive success and survival, in a population of eiders nesting in the eastern Canadian Arctic during a capricious period marked by annual avian cholera outbreaks. We collected CORTf data from feathers grown during previous moult in autumn and data on phenology of subsequent reproduction and survival for 242 eider females over 5 years. Using path analyses, we detected a direct relationship between CORTf and arrival date and body condition the following year. CORTf also had negative indirect relationships with both eider reproductive success and survival of eiders during an avian cholera outbreak. This indirect effect was dramatic with a reduction of approximately 30% in subsequent survival of eiders during an avian cholera outbreak when mean CORTf increased by 1 standard deviation. This study highlights the importance of events or processes occurring during moult on subsequent expression of life-history traits and relation to individual fitness, and shows that information from non-destructive sampling of individuals can track carry-over effects across seasons. PMID:25540279

  8. Feather corticosterone reveals effect of moulting conditions in the autumn on subsequent reproductive output and survival in an Arctic migratory bird.

    PubMed

    Harms, N Jane; Legagneux, Pierre; Gilchrist, H Grant; Bêty, Joël; Love, Oliver P; Forbes, Mark R; Bortolotti, Gary R; Soos, Catherine

    2015-02-01

    For birds, unpredictable environments during the energetically stressful times of moulting and breeding are expected to have negative fitness effects. Detecting those effects however, might be difficult if individuals modulate their physiology and/or behaviours in ways to minimize short-term fitness costs. Corticosterone in feathers (CORTf) is thought to provide information on total baseline and stress-induced CORT levels at moulting and is an integrated measure of hypothalamic-pituitary-adrenal activity during the time feathers are grown. We predicted that CORTf levels in northern common eider females would relate to subsequent body condition, reproductive success and survival, in a population of eiders nesting in the eastern Canadian Arctic during a capricious period marked by annual avian cholera outbreaks. We collected CORTf data from feathers grown during previous moult in autumn and data on phenology of subsequent reproduction and survival for 242 eider females over 5 years. Using path analyses, we detected a direct relationship between CORTf and arrival date and body condition the following year. CORTf also had negative indirect relationships with both eider reproductive success and survival of eiders during an avian cholera outbreak. This indirect effect was dramatic with a reduction of approximately 30% in subsequent survival of eiders during an avian cholera outbreak when mean CORTf increased by 1 standard deviation. This study highlights the importance of events or processes occurring during moult on subsequent expression of life-history traits and relation to individual fitness, and shows that information from non-destructive sampling of individuals can track carry-over effects across seasons. PMID:25540279

  9. THE ESTROGENIC AND ANTIANDROGENIC PESTICIDE METHOXYCHLOR ALTERS THE REPRODUCTIVE TRACT AND BEHAVIOR WITHOUT AFFECTING PITUITARY SIZE OR LH AND PROLACTIN SECRETION IN MALE RATS

    EPA Science Inventory

    The estrogenic and antiandrogenic pesticide methoxychlor alters the reproductive tract and behavior without affecting pituitary size or LH and prolactin secretion in male rats.

    Gray LE Jr, Ostby J, Cooper RL, Kelce WR.

    Endocrinology Branch, United States Environment...

  10. Female access and diet affect insemination success, senescence, and the cost of reproduction in male Mexican fruit flies Anastrepha ludens

    PubMed Central

    HARWOOD, JAMES F.; CHEN, KEHUI; LIEDO, PABLO; MÜLLER, HANS-GEORG; WANG, JANE-LING; MORICE, AMY E.; CAREY, JAMES R.

    2014-01-01

    Hypotheses exploring the influence of dietary conditions on the life history trade-off between survival and reproductive success are extensively tested in female insects, but are rarely explored in males. Here, the impact of dietary quality and female access on age-specific reproduction and survival of male Mexican fruit flies, Anastrepha ludens Loew (Diptera: Tephritidae), are examined. There is a clear cost of female access for males with access to dietary protein, measurable as a decrease in life expectancy, which is further influenced by the age when females are introduced. A protein deficient diet reduces the lifespan benefit of virginity and masks the detrimental effect of female access on male life expectancy. Dietary protein is not necessary for reproductive success, but access to protein at eclosion improves the lifetime reproductive success of males compared to when it is delayed. Overall, reproductive success diminishes as the male flies age, regardless of the dietary conditions, providing evidence for reproductive senescence in males. Delaying the males’ access to a protein source fails to influence the negative effect of age on reproductive ability. Because age specific reproductive rates decline with age, regardless of diet, male fitness does not benefit from lifespan extension. Therefore, males can be expected to allocate available resources towards reproductive effort in favour of extended lifespan, regardless of mate and protein availability. PMID:25709143

  11. Factors affecting reproductive performance of white-tailed deer subjected to fixed-time artificial insemination or natural mating.

    PubMed

    Mellado, Miguel; Orta, Claudia G; Lozano, Eloy A; García, Jose E; Veliz, Francisco G; de Santiago, Angeles

    2013-01-01

    The objectives of this study were to examine the effects of several factors affecting fawning rate, litter size, litter weight and neonatal fawn mortality in white-tailed deer inseminated either transcervically or by means of laparoscopy. Oestrus synchronisation with a controlled internal drug release (CIDR)-based protocol and fixed-time artificial insemination (FTAI) was conducted in 130 white-tailed deer (Odocoileus virginianus texanus) during three reproductive seasons (2007-2009; 271 services) in a game-hunting ranch in a hot-arid environment (26°4' N, 101°25' W). Ninety additional non-treated does were exposed to bucks for natural mating. Fawning rate did not differ between AI methods (40.0 vs 45.0% for transcervical and laparoscopic AI, respectively). Overall fawning rate (proportion of all does fawning after FTAI and a subsequent period of buck exposure) did not differ between transcervical (89.5%), laparoscopic (80.3%) or natural (88.9%) insemination. Litter size per fawning doe was higher (P<0.05) in naturally-served does (1.65±0.48) than in transcervically-inseminated does (1.40±0.51) or in laparoscopically-inseminated does (1.48±0.50). The main conclusion was that no enhancement of fawning rate or litter size occurred as a result of intrauterine deposition of semen by laparoscopy compared with the transcervical insemination technique. PMID:23464502

  12. Developmental Exposure to Ethinylestradiol Affects Reproductive Physiology, the GnRH Neuroendocrine Network and Behaviors in Female Mouse

    PubMed Central

    Derouiche, Lyes; Keller, Matthieu; Martini, Mariangela; Duittoz, Anne H.; Pillon, Delphine

    2015-01-01

    During development, environmental estrogens are able to induce an estrogen mimetic action that may interfere with endocrine and neuroendocrine systems. The present study investigated the effects on the reproductive function in female mice following developmental exposure to pharmaceutical ethinylestradiol (EE2), the most widespread and potent synthetic steroid present in aquatic environments. EE2 was administrated in drinking water at environmentally relevant (ENVIR) or pharmacological (PHARMACO) doses [0.1 and 1 μg/kg (body weight)/day respectively], from embryonic day 10 until postnatal day 40. Our results show that both groups of EE2-exposed females had advanced vaginal opening and shorter estrus cycles, but a normal fertility rate compared to CONTROL females. The hypothalamic population of GnRH neurons was affected by EE2 exposure with a significant increase in the number of perikarya in the preoptic area of the PHARMACO group and a modification in their distribution in the ENVIR group, both associated with a marked decrease in GnRH fibers immunoreactivity in the median eminence. In EE2-exposed females, behavioral tests highlighted a disturbed maternal behavior, a higher lordosis response, a lack of discrimination between gonad-intact and castrated males in sexually experienced females, and an increased anxiety-related behavior. Altogether, these results put emphasis on the high sensitivity of sexually dimorphic behaviors and neuroendocrine circuits to disruptive effects of EDCs. PMID:26696819

  13. CO2 and fertility affect growth and reproduction but not susceptibility to aphids in field grown Solanum ptycanthum

    SciTech Connect

    Long, T.M.

    1995-09-01

    In general, C3 annual plants respond positively in terms of growth, reproduction and biomass accrued when grown under elevated levels of atmospheric carbon dioxide. However, most studies documenting this response have been conducted in growth chambers where plants can be reared under conditions free form environmental stressors such as nutrient and water constraints, UV exposure and damage from pests. During the 1993 fieldseason, I grew 200 individuals of Solanum ptycanthum in an array of 10 outdoor, open-topped CO2 enclosures (5 @ 700 ppm CO2) at the University of Michigan Biological Station in Pellston, MI. Half of the plants were grown in a 50;50 mix of native C-horizon soil and topsoil (low fertility); the other half were grown in 100% topsoil (high-fertility). Plants were censused throughout the growing season for flower and fruit production, growth rate and degree of infestation of aphids. Fertility and CO2 both significantly affected production of flowers and fruits, but only fertility was significantly related to vegetative growth. Aphid infestation varied significantly among enclosures, but was not related to CO2 or fertility.

  14. Nutrient limitation restricts growth and reproductive output in a tropical montane cloud forest bromeliad: findings from a long-term forest fertilization experiment.

    PubMed

    Lasso, Eloisa; Ackerman, James D

    2013-01-01

    From studies in seasonal lowland tropical forests, bromeliad epiphytes appear to be limited mainly by water, and to a lesser extent by nutrient supply, especially phosphorous. Less is understood about the mineral nutrition of tropical montane cloud forest (TMCF) epiphytes, even though their highest diversity is in this habitat. Nutrient limitation is known to be a key factor restricting forest productivity in TMCF, and if epiphytes are nutritionally linked to their host trees, as has been suggested, we would expect that they are also nutrient limited. We studied the effect of a higher nutrient input on reproduction and growth of the tank bromeliad Werauhia sintenisii in experimental plots located in a TMCF in Puerto Rico, where all macro- and micronutrients had been added quarterly starting in 1989 and continuing throughout the duration of this study. We found that bromeliads growing in fertilized plots were receiving litterfall with higher concentrations of N, P, and Zn and had higher concentrations of P, Zn, Fe, Al, and Na in their vegetative body. The N:P ratios found (fertilized = 27.5 and non-fertilized = 33.8) suggest that W. sintenisii may also be phosphorous limited as are lowland epiphytes. Fertilized plants had slightly longer inflorescences, and more flowers per inflorescence, than non-fertilized plants, but their flowers produced nectar in similar concentrations and quantities. Fertilized plants produced more seeds per fruit and per plant. Frequency of flowering in two consecutive years was higher for fertilized plants than for controls, suggesting that fertilized plants overcome the cost of reproduction more readily than non-fertilized plants. These results provide evidence that TMCF epiphytic bromeliads are nutrient limited like their lowland counterparts. PMID:22767363

  15. Does catch and release affect the mating system and individual reproductive success of wild Atlantic salmon (Salmo salar L.)?

    PubMed

    Richard, Antoine; Dionne, Mélanie; Wang, Jinliang; Bernatchez, Louis

    2013-01-01

    In this study, we documented the breeding system of a wild population of Atlantic salmon (Salmo salar L.) by genetically sampling every returning adult and assessed the determinants of individual fitness. We then quantified the impacts of catch and release (C&R) on mating and reproductive success. Both sexes showed high variance in individual reproductive success, and the estimated standardized variance was higher for males (2.86) than for females (0.73). We found a weak positive relationship between body size and fitness and observed that fitness was positively correlated with the number of mates, especially in males. Mature male parr sired 44% of the analysed offspring. The impact of C&R on the number of offspring was size dependent, as the reproductive success of larger fish was more impaired than smaller ones. Also, there was an interactive negative effect of water temperature and air exposure time on reproductive success of C&R salmon. This study improves our understanding of the complex reproductive biology of the Atlantic salmon and is the first to investigate the impact of C&R on reproductive success. Our study expands the management toolbox of appropriate C&R practices that promote conservation of salmon populations and limit negative impacts on mating and reproductive success. PMID:23163395

  16. CRF-Like Diuretic Hormone Negatively Affects Both Feeding and Reproduction in the Desert Locust, Schistocerca gregaria

    PubMed Central

    Van Wielendaele, Pieter; Dillen, Senne; Marchal, Elisabeth; Badisco, Liesbeth; Vanden Broeck, Jozef

    2012-01-01

    Diuretic hormones (DH) related to the vertebrate Corticotropin Releasing Factor (CRF) have been identified in diverse insect species. In the migratory locust, Locusta migratoria, the CRF-like DH (CRF/DH) is localized in the same neurosecretory cells as the Ovary Maturating Parsin (OMP), a neurohormone that stimulates oocyte growth, vitellogenesis and hemolymph ecdysteroid levels in adult female locusts. In this study, we investigated whether CRF-like DH can influence feeding and reproduction in the desert locust, Schistocerca gregaria. We identified two highly similar S. gregaria CRF-like DH precursor cDNAs, each of which also encodes an OMP isoform. Alignment with other insect CRF-like DH precursors shows relatively high conservation of the CRF/DH sequence while the precursor region corresponding to OMP is not well conserved. Quantitative real-time RT-PCR revealed that the precursor transcripts mainly occur in the central nervous system and their highest expression level was observed in the brain. Injection of locust CRF/DH caused a significantly reduced food intake, while RNAi knockdown stimulated food intake. Therefore, our data indicate that CRF-like DH induces satiety. Furthermore, injection of CRF/DH in adult females retarded oocyte growth and caused lower ecdysteroid titers in hemolymph and ovaries, while RNAi knockdown resulted in opposite effects. The observed effects of CRF/DH may be part of a wider repertoire of neurohormonal activities, constituting an integrating control system that affects food intake and excretion, as well as anabolic processes like oocyte growth and ecdysteroidogenesis, following a meal. Our discussion about the functional relationship between CRF/DH and OMP led to the hypothesis that OMP may possibly act as a monitoring peptide that can elicit negative feedback effects. PMID:22363645

  17. The Effect of Latitudinal Variation on Shrimp Reproductive Strategies.

    PubMed

    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. PMID:27158895

  18. The Effect of Latitudinal Variation on Shrimp Reproductive Strategies

    PubMed Central

    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. PMID:27158895

  19. Do local adaptation and the reproductive tactic of Atlantic salmon (Salmo salar L.) affect offspring metabolic capacities?

    PubMed

    Rossignol, O; Dodson, J J; Marquilly, C; Guderley, H

    2010-01-01

    Atlantic salmon (Salmo salar L.) is an iteroparous, anadromous species that exhibits some of the greatest within-population variability in size and age at maturity of all vertebrates. In the conditional reproductive strategy of salmonids, the male reproductive tactic expressed is believed to depend on an individual male's status relative to others in the population and therefore depends on his capacity to attain a physiological threshold, the exact nature of which is unknown. Although the threshold is influenced by local biotic and abiotic conditions, it is likely to be under genetic control. Our study examined whether the early growth, muscle metabolic capacities, routine metabolic rate, and spontaneous swimming of salmon alevins reared in laboratory conditions varied with the population of origin, maternal investment, and the paternal reproductive tactic. Our experimental design allowed us to establish that neither the population of origin nor the paternal reproductive tactic influenced the physiological capacities of alevins. The strong influence of the mother on alevin metabolic capacities suggests that the bioenergetic differences in metabolic capacities, realized metabolic rates, and activity levels that could eventually dictate the reproductive tactic of male offspring may originate in maternal effects. PMID:20350165

  20. Reproductive allocation in plants as affected by elevated carbon dioxide and other environmental changes: a synthesis using meta-analysis and graphical vector analysis.

    PubMed

    Wang, Xianzhong; Taub, Daniel R; Jablonski, Leanne M

    2015-04-01

    Reproduction is an important life history trait that strongly affects dynamics of plant populations. Although it has been well documented that elevated carbon dioxide (CO2) in the atmosphere greatly enhances biomass production in plants, the overall effect of elevated CO2 on reproductive allocation (RA), i.e., the proportion of biomass allocated to reproductive structures, is little understood. We combined meta-analysis with graphical vector analysis to examine the overall effect of elevated CO2 on RA and how other environmental factors, such as low nutrients, drought and elevated atmospheric ozone (O3), interacted with elevated CO2 in affecting RA in herbaceous plants. Averaged across all species of different functional groups and environmental conditions, elevated CO2 had little effect on RA (-0.9%). RA in plants of different reproductive strategies and functional groups, however, differed in response to elevated CO2. For example, RA in iteroparous wild species decreased by 8%, while RA in iteroparous crops increased significantly (+14%) at elevated CO2. RA was unaffected by CO2 in plants grown with no stress or in low-nutrient soils. RA decreased at elevated CO2 and elevated O3, but increased in response to elevated CO2 in drought-stressed plants, suggesting that elevated CO2 could ameliorate the adverse effect of drought on crop production to some extent. Our results demonstrate that elevated CO2 and other global environmental changes have the potential to greatly alter plant community composition through differential effects on RA of different plant species and thus affect the dynamics of natural and agricultural ecosystems in the future. PMID:25537120

  1. Factors affecting reproductive success and life history parameters of Bracon hebetor Say (Hymenoptera: Braconidae) from three host-associated populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Augmentative releases of native natural enemies are viable strategies for suppression of crop pests. Appropriate mass rearing and release strategies rely on a thorough understanding of the reproductive biology of the natural enemy. In the present study, we evaluated the effects of parasitoid source ...

  2. Dehydration-stress affects vegetative reproduction and transcriptome profiles in underground adventitious buds of leafy spurge (Euphorbia esula)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leafy spurge is an invasive perennial weed that infests mainly range, recreational and right-of-way lands in the great plains of the US and Canada. Although spread occurs by both seeds and roots, the perennial nature of leafy spurge is attributed to vegetative reproduction from an abundance of under...

  3. Evaluation of quantitative trait loci affecting intramuscular fat and reproductive traits in pigs using marker-assisted introgression.

    PubMed

    Sato, S; Ohnishi, C; Kikuchi, T; Kohira, K; Egawa, S; Terai, S; Nakamura, T; Arata, S; Komatsuda, A; Uemoto, Y

    2014-12-01

    We investigated the effects of previously identified quantitative trait loci (QTL) in an experimental backcross (BC) between Chinese Meishan pigs and commercial Duroc pigs. We performed marker-assisted introgression of two QTL for intramuscular fat (IMF) content (IMF population) and three QTL for reproductive traits (reproduction population) from a donor Meishan pig into a recipient Duroc pig. At the fourth BC generation of the IMF population and third BC generation of the reproduction population, carrier animals were selected for the production of animals homozygous for the QTL. Our previous studies have shown that the presence of a Meishan allele on the IMF QTL is associated with low IMF values, and the Meishan allele on the reproductive QTL is associated with large litters. In this study, the presence of a Duroc allele at the IMF QTL on SSC9 resulted in a 0.27% increase in IMF (additive effect = 0.27 ± 0.08), whereas the presence of a Meishan allele at the IMF QTL on SSC7 resulted in a 0.34% increase in IMF (additive effect = -0.34 ± 0.09). The presence of the Meishan allele at the IMF QTL on SSC7 thus had the opposite effect to our previous studies, that is, increased IMF. In the reproduction population, we observed no differences between the genotypes of the three QTL in regard to number of corpora lutea or litter size. Marker-assisted introgression at these QTL is thus unlikely to result in an associated increase in litter size. These results show that it is possible to introgress alleles from other breeds into a selection population using molecular markers; any unexpected results might be associated with the genetic background. PMID:25099662

  4. Evaluation of non-genetic factors affecting calf growth, reproductive performance and milk yield of traditionally managed Sheko cattle in southwest Ethiopia.

    PubMed

    Bayou, E; Haile, A; Gizaw, S; Mekasha, Y

    2015-01-01

    The study was conducted to estimate calf growth, reproductive performance and milk yield of Ethiopia Sheko cattle and to assess non-genetic factors affecting their performance in their home tract as a step towards designing sustainable cattle conservation and improvement strategy. All the growth traits considered in the study were significantly affected by all non-genetic factors considered except for the fixed effects of Agro ecological zones (AEZs) and season of birth which were not significant for post weaning daily gain. Calving interval (CI) and days open (DO) were significantly influenced by AEZs, season and dam parity. Cows that calved in lowland had shorter CI and DO than cows which calved in midland. Cows that calved in short rainy season had Short CI and DO than those calved during dry season or long rainy season. Cows which calved for the first time had the longest CI and DO from the other parities whereas cows on their fifth parity had the shortest CI and DO. AEZ significantly affected lactation milk yield (LMY) and lactation length (LL), but not significant on daily milk yield (DMY) and 305 days yield (305DY). Season was significant on all milk traits considered except DMY. Parity effect was significant on LMY and 305DY, whereas DMY and LL were not affected. The non-genetic factors had significant effects for all of the reproductive; and many of the growth and milk performance traits considered and hence will need to be considered in cattle breed improvement program. PMID:26543703

  5. Moisture source and diet affect development and reproduction of Orius thripoborus and Orius naivashae, two predatory anthocorids from Southern Africa.

    PubMed

    Bonte, Jochem; Vangansbeke, Dominiek; Maes, Sara; Bonte, Maarten; Conlong, Des; De Clercq, Patrick

    2012-01-01

    The effect of moisture source and diet on the development and reproduction of the pirate bugs, Orius thripoborus (Hesse) and Orius naivashae (Poppius) (Hemiptera: Anthocoridae) was examined in the laboratory. Both species had been collected in and around sugarcane fields in South Africa. Supplementing eggs of the flour moth Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) with a green bean pod as a moisture source yielded better nymphal survival and faster development, as compared with free water encapsulated in Parafilm, suggesting that the predators may extract extra nutrients from the bean pod. The impact of two factitious foods and moist honey bee pollen on developmental and reproductive parameters of both predators was also investigated. The overall performance of both Orius species on E. kuehniella eggs and cysts of brine shrimp, Artemia franciscana Kellogg (Crustacea: Artemiidae) was better than on pollen. Nonetheless, a pollen diet alone allowed 66 and 78% of the nymphs of O. thripoborus and O. naivashae, respectively, to reach adulthood. Overall, developmental and reproductive performance of O. thripoborus on the tested diets was superior to that of O. naivashae. The implications of these findings for the mass production of these predators and their potential role in biological control programs in southern Africa are discussed. PMID:22935002

  6. Moisture Source and Diet affect Development and Reproduction of Orius thripoborus and Orius naivashae, two Predatory Anthocorids from Southern Africa

    PubMed Central

    Bonte, Jochem; Vangansbeke, Dominiek; Maes, Sara; Bonte, Maarten; Conlong, Des; Clercq, Patrick De

    2012-01-01

    The effect of moisture source and diet on the development and reproduction of the pirate bugs, Orius thripoborus (Hesse) and Orius naivashae (Poppius) (Hemiptera: Anthocoridae) was examined in the laboratory. Both species had been collected in and around sugarcane fields in South Africa. Supplementing eggs of the flour moth Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) with a green bean pod as a moisture source yielded better nymphal survival and faster development, as compared with free water encapsulated in Parafilm, suggesting that the predators may extract extra nutrients from the bean pod. The impact of two factitious foods and moist honey bee pollen on developmental and reproductive parameters of both predators was also investigated. The overall performance of both Orius species on E. kuehniella eggs and cysts of brine shrimp, Artemia franciscana Kellogg (Crustacea: Artemiidae) was better than on pollen. Nonetheless, a pollen diet alone allowed 66 and 78% of the nymphs of O. thripoborus and O. naivashae, respectively, to reach adulthood. Overall, developmental and reproductive performance of O. thripoborus on the tested diets was superior to that of O. naivashae. The implications of these findings for the mass production of these predators and their potential role in biological control programs in southern Africa are discussed. PMID:22935002

  7. How Does Religious Affiliation Affect Women’s Attitudes Toward Reproductive Health Policy? Implications for the Affordable Care Act

    PubMed Central

    Patton, Elizabeth W.; Hall, Kelli Stidham; Dalton, Vanessa K.

    2015-01-01

    Structured Abstract Background Supreme Court cases challenging the Affordable Care Act (ACA) mandate for employer-provided reproductive health care have focused on religiously based opposition to coverage. Little is known about women’s perspectives on such reproductive health policies. Study Design Data were drawn from the Women’s Health Care Experiences and Preferences survey, a randomly selected, nationally representative sample of 1078 US women age 18–55. We examined associations between religious affiliation and attitudes toward employer-provided insurance coverage of contraception and abortion services, and the exclusion of religious institutions from this coverage. We used chi-square and multivariable logistic regression for analysis. Results Respondents self-identified as Baptist (18%), Protestant (Other Mainline, 17%), Catholic (17%), Other Christian (20%), Religious, Non-Christian (7%) or no affiliation (21%). Religious affiliation was associated with proportions of agreement for contraception (p = 0.03), abortion (p <0.01), and religious exclusion (p <0.01) policies. In multivariable models, differences in the odds of agreement varied across religious affiliations and frequency of service attendance. For example, compared to non-affiliated women, Baptists and Other Nondenominational Christians (but not Catholics) had lower odds of agreement with employer coverage of contraception (OR 0.63, 95% CI 0.4-0.1 and OR 0.57, CI 0.4–0.9, respectively); women who attended services weekly or more than weekly had lower odds of agreement (OR 0.53, 95% CI 0.3–0.8 and OR 0.33, CI 0.2–0.6, respectively), compared to less frequent attenders. Conclusions Recent religiously motivated legal challenges to employer-provided reproductive health care coverage may not represent the attitudes of many religious women. PMID:25727764

  8. Contrasting effects of ocean acidification on reproduction in reef fishes

    NASA Astrophysics Data System (ADS)

    Welch, Megan J.; Munday, Philip L.

    2016-06-01

    Differences in the sensitivity of marine species to ocean acidification will influence the structure of marine communities in the future. Reproduction is critical for individual and population success, yet is energetically expensive and could be adversely affected by rising CO2 levels in the ocean. We investigated the effects of projected future CO2 levels on reproductive output of two species of coral reef damselfish, Amphiprion percula and Acanthochromis polyacanthus. Adult breeding pairs were maintained at current-day control (446 μatm), moderate (652 μatm) or high CO2 (912 μatm) for a 9-month period that included the summer breeding season. The elevated CO2 treatments were consistent with CO2 levels projected by 2100 under moderate (RCP6) and high (RCP8) emission scenarios. Reproductive output increased in A. percula, with 45-75 % more egg clutches produced and a 47-56 % increase in the number of eggs per clutch in the two elevated CO2 treatments. In contrast, reproductive output decreased at high CO2 in Ac. polyacanthus, with approximately one-third as many clutches produced compared with controls. Egg survival was not affected by CO2 for A. percula, but was greater in elevated CO2 for Ac. polyacanthus. Hatching success was also greater for Ac. polyacanthus at elevated CO2, but there was no effect of CO2 treatments on offspring size. Despite the variation in reproductive output, body condition of adults did not differ between control and CO2 treatments in either species. Our results demonstrate different effects of high CO2 on fish reproduction, even among species within the same family. A greater understanding of the variation in effects of ocean acidification on reproductive performance is required to predict the consequences for future populations of marine organisms.

  9. Experimental defoliation affects male but not female reproductive performance of the tropical monoecious plant Croton suberosus (Euphorbiaceae)

    PubMed Central

    Narbona, Eduardo; Dirzo, Rodolfo

    2010-01-01

    Background and Aims Monoecious plants have the capacity to allocate resources separately to male and female functions more easily than hermaphrodites. This can be advantageous against environmental stresses such as leaf herbivory. However, studies showing effects of herbivory on male and female functions and on the interaction with the plant's pollinators are limited, particularly in tropical plants. Here, the effects of experimental defoliation were examined in the monoecious shrub Croton suberosus (Euphorbiaceae), a wasp-pollinated species from a Mexican tropical dry forest. Methods Three defoliation treatments were applied: 0 % (control), 25 % (low) or 75 % (high) of plant leaf area removed. Vegetative (production of new leaves) and reproductive (pistillate and staminate flower production, pollen viability, nectar production, fruit set, and seed set) performance variables, and the abundance and activity of floral visitors were examined. Key Results Defoliated plants overcompensated for tissue loss by producing more new leaves than control plants. Production of staminate flowers gradually decreased with increasing defoliation and the floral sex ratio (staminate : pistillate flowers) was drastically reduced in high-defoliation plants. In contrast, female reproductive performance (pistillate flower production, fruit set and seed set) and pollinator visitation and abundance were not impacted by defoliation. Conclusions The asymmetrical effects of defoliation on male and female traits of C. suberosus may be due to the temporal and spatial flexibility in the allocation of resources deployed by monoecious plants. We posit that this helps to maintain the plant's pollination success in the face of leaf herbivory stress. PMID:20519239

  10. Neonatal exposure to 17α-ethynyl estradiol affects ovarian gene expression and disrupts reproductive cycles in female rats.

    PubMed

    Nozawa, Kaori; Nagaoka, Kentaro; Zhang, Haolin; Usuda, Kento; Okazaki, Sachiko; Taya, Kazuyoshi; Yoshida, Midori; Watanabe, Gen

    2014-07-01

    Neonatal exposure to synthetic estrogen causes delayed reproductive dysfunction in female rats. Exposure to 17α-ethynyl estradiol (EE, low: 20 and high: 2000 μg/kg) induced an abnormal estrous cycle during PND171-190 in low-dose and PND126-145 in high-dose group. At PND90 within normal estrous cycle, high-dose animals showed lack of LH surge and low of ovarian hormones in serum level. Gene expression analysis demonstrated that level of mRNA encoding luteinizing hormone/chorionic gonadotropin receptor (LHCGR) was higher in EE-treated ovaries than in control ovaries, and LHCGR protein colocalized with apoptosis-related proteins in the interstitial area of the ovary. At PND1, ovarian LHCGR mRNA levels were higher in EE-treated rats than in control rats, and direct induction of LHCGR expression by EE was observed in vitro. Our results indicate that neonatal exposure to EE induces irregular LHCGR expression in the immature ovary, which may influence the occurrence of delayed reproductive dysfunction in adult animals. PMID:24632129

  11. Nest-site selection and reproductive success of greater sage-grouse in a fire-affected habitat of northwestern Nevada

    USGS Publications Warehouse

    Lockyer, Zachary B.; Coates, Peter S.; Casazza, Michael L.; Espinosa, Shawn; Delehanty, David J.

    2015-01-01

    Identifying links between micro-habitat selection and wildlife reproduction is imperative to population persistence and recovery. This information is particularly important for landscape species such as greater sage-grouse (Centrocercus urophasianus; sage-grouse). Although this species has been widely studied, because environmental factors can affect sage-grouse populations, local and regional studies are crucial for developing viable conservation strategies. We studied the habitat-use patterns of 71 radio-marked sage-grouse inhabiting an area affected by wildfire in the Virginia Mountains of northwestern Nevada during 2009–2011 to determine the effect of micro-habitat attributes on reproductive success. We measured standard vegetation parameters at nest and random sites using a multi-scale approach (range = 0.01–15,527 ha). We used an information-theoretic modeling approach to identify environmental factors influencing nest-site selection and survival, and determine whether nest survival was a function of resource selection. Sage-grouse selected micro-sites with greater shrub canopy cover and less cheatgrass (Bromus tectorum) cover than random sites. Total shrub canopy, including sagebrush (Artemisia spp.) and other shrub species, at small spatial scales (0.8 ha and 3.1 ha) was the single contributing selection factor to higher nest survival. These results indicate that reducing the risk of wildfire to maintain important sagebrush habitats could be emphasized in sage-grouse conservation strategies in Nevada. Managers may seek to mitigate the influx of annual grass invasion by preserving large intact sagebrush-dominated stands with a mixture of other shrub species. For this area of Nevada, the results suggest that ≥40% total shrub canopy cover in sage-grouse nesting areas could yield improved reproductive success. 

  12. Food availability and reproduction affects lipid and fatty acid composition of the brown mussel, Perna perna, raised in suspension culture.

    PubMed

    Narváez, Mirle; Freites, L; Guevara, M; Mendoza, J; Guderley, H; Lodeiros, C J; Salazar, G

    2008-02-01

    We examined the influence of the reproductive cycle and environmental factors on variations of the condition index (CI), tissue dry mass, shell size, total lipid content, and relative percent of fatty acids in the mussel, Perna perna. Spat or juveniles were reared to commercial size (70 mm) in suspension culture in the Golfo de Cariaco, Venezuela between May and October 2004. The dry mass of soft tissues and shell, a visual assessment of gonadal status and the organism lipid profile were established every fortnight. In parallel, we measured the environmental conditions, following chlorophyll a, salinity, temperature and seston levels. After an initial decrease, the CI rose and remained high until August after which it decreased continuously until October. Total lipid values also decreased initially, after which they showed two periods of rapid recuperation and depletion, the first between May and August and the second between August and October. Similar tendencies were noted in the fatty acids, C18:3n-3, C18:4n-3 and C22:6n-3. Correlation analysis found no significant relationships between environmental parameters and the variations in total lipids. However, significant correlations were noted between fatty acids and specific environmental parameters. In particular, temperature was inversely correlated with C14:0, C16:1n-7, C18:0, C18:1n-9 and 20:5n-3. Chlorophyll a was positively correlated with C14:0, C16:1n-7, C18:1n-7, C18:4n-3 and 20:4n-6. On the other hand, gametogenesis had an effect on C14:0, C16:1n-7, C18:1n-9 and C18:1n-7, while spawned and gonadal regression states had an effect on fatty acid 20:4n-6. Temperature and chlorophyll a levels strongly influenced the proportion of mussels spawning, suggesting that their influence upon lipid composition may be secondary to their impact upon reproduction. Despite the thermal stability of this tropical system, the lipid composition of mussels changed markedly during the study, reflecting the central role of diet

  13. Targeted disruption of the mouse prosaposin gene affects the development of the prostate gland and other male reproductive organs.

    PubMed

    Morales, C R; Zhao, Q; El-Alfy, M; Suzuki, K

    2000-01-01

    The prosaposin gene encodes a 65-70 kilodalton (kd) protein, which is secreted or targeted to lysosomes. In lysosomes, prosaposin is the precursor of 4 activator proteins, designated saposins A, B, C, and D, which promote by acidic hydrolases, the degradation of glycosphingolipids with short oligosaccharide chains. Mutations of the prosaposin gene have been linked to several lysosomal storage disorders. An animal model was recently developed by creating a null allele in embryonic stem cells through gene targeting in order to investigate the phenotypic diversity of prosaposin mutations, the involvement of this protein in lysosomal storage diseases, and to develop potential therapeutic approaches. Mutant homozygous mice die at 35-40 days of age and neurological disorders contribute to their early death. Secreted prosaposin is present in milk and in cerebrospinal and seminal fluids. In the nervous system, prosaposin exhibits a trophic activity. Examination of reproduc-tive organs in homozygous mutant males shows several abnormalities such as a decrease in testis size with reduced spermiogenesis, and an involution of the prostate, seminal vesicle, and epididymis, although levels of testosterone in blood remain normal. In the prostate of homozygous mutants, only basal cells appear to be present, whereas secretory cells are absent. The epithelia in efferent ducts is formed by ciliated cells, whereas heterozygotes exhibit a majority of nonciliated cells. Our data indicate that prosaposin is involved in the development and maintenance of male reproductive organs. In prostatic epithelium, targeted disruption of the prosaposin gene appears to inactivate the mitogen-activated protein kinase pathway and to interfere with differentiation of secretory cells. PMID:11105903

  14. The Arabidopsis DSO/ABCG11 transporter affects cutin metabolism in reproductive organs and suberin in roots.

    PubMed

    Panikashvili, David; Shi, Jian Xin; Bocobza, Samuel; Franke, Rochus Benni; Schreiber, Lukas; Aharoni, Asaph

    2010-05-01

    Apart from its significance in the protection against stress conditions, the cuticular cover is essential for proper development of the diverse surface structures formed on aerial plant organs. This layer mainly consists of a cutin matrix, embedded and overlaid with cuticular waxes. Following their biosynthesis in epidermal cells, cutin and waxes were suggested to be exported across the plasma membrane by ABCG-type transporters such as DSO/ABCG11 to the cell wall and further to extracellular matrix. Here, additional aspects of DSO/ABCG11 function were investigated, predominantly in reproductive organs, which were not revealed in the previous reports. This was facilitated by the generation of a transgenic DSO/ABCG11 silenced line (dso-4) that displayed relatively subtle morphological and chemical phenotypes. These included altered petal and silique morphology, fusion of seeds, and changes in levels of cutin monomers in flowers and siliques. The dso-4 phenotypes corresponded to the strong DSO/ABCG11 gene expression in the embryo epidermis as well as in the endosperm tissues of the developing seeds. Moreover, the DSO/ABCG11 protein displayed polar localization in the embryo protoderm. Transcriptome analysis of the dso-4 mutant leaves and stems showed that reduced DSO/ABCG11 activity suppressed the expression of a large number of cuticle-associated genes, implying that export of cuticular lipids from the plasma membrane is a rate-limiting step in cuticle metabolism. Surprisingly, root suberin composition of dso-4 was altered, as well as root expression of two suberin biosynthetic genes. Taken together, this study provides new insights into cutin and suberin metabolism and their role in reproductive organs and roots development. PMID:20035035

  15. The sleeping beauty: how reproductive diapause affects hormone signaling, metabolism, immune response and somatic maintenance in Drosophila melanogaster.

    PubMed

    Kubrak, Olga I; Kučerová, Lucie; Theopold, Ulrich; Nässel, Dick R

    2014-01-01

    Some organisms can adapt to seasonal and other environmental challenges by entering a state of dormancy, diapause. Thus, insects exposed to decreased temperature and short photoperiod enter a state of arrested development, lowered metabolism, and increased stress resistance. Drosophila melanogaster females can enter a shallow reproductive diapause in the adult stage, which drastically reduces organismal senescence, but little is known about the physiology and endocrinology associated with this dormancy, and the genes involved in its regulation. We induced diapause in D. melanogaster and monitored effects over 12 weeks on dynamics of ovary development, carbohydrate and lipid metabolism, as well as expression of genes involved in endocrine signaling, metabolism and innate immunity. During diapause food intake diminishes drastically, but circulating and stored carbohydrates and lipids are elevated. Gene transcripts of glucagon- and insulin-like peptides increase, and expression of several target genes of these peptides also change. Four key genes in innate immunity can be induced by infection in diapausing flies, and two of these, drosomycin and cecropin A1, are upregulated by diapause independently of infection. Diapausing flies display very low mortality, extended lifespan and decreased aging of the intestinal epithelium. Many phenotypes induced by diapause are reversed after one week of recovery from diapause conditions. Furthermore, mutant flies lacking specific insulin-like peptides (dilp5 and dilp2-3) display increased diapause incidence. Our study provides a first comprehensive characterization of reproductive diapause in D. melanogaster, and evidence that glucagon- and insulin-like signaling are among the key regulators of the altered physiology during this dormancy. PMID:25393614

  16. The Sleeping Beauty: How Reproductive Diapause Affects Hormone Signaling, Metabolism, Immune Response and Somatic Maintenance in Drosophila melanogaster

    PubMed Central

    Kubrak, Olga I.; Kučerová, Lucie; Theopold, Ulrich; Nässel, Dick R.

    2014-01-01

    Some organisms can adapt to seasonal and other environmental challenges by entering a state of dormancy, diapause. Thus, insects exposed to decreased temperature and short photoperiod enter a state of arrested development, lowered metabolism, and increased stress resistance. Drosophila melanogaster females can enter a shallow reproductive diapause in the adult stage, which drastically reduces organismal senescence, but little is known about the physiology and endocrinology associated with this dormancy, and the genes involved in its regulation. We induced diapause in D. melanogaster and monitored effects over 12 weeks on dynamics of ovary development, carbohydrate and lipid metabolism, as well as expression of genes involved in endocrine signaling, metabolism and innate immunity. During diapause food intake diminishes drastically, but circulating and stored carbohydrates and lipids are elevated. Gene transcripts of glucagon- and insulin-like peptides increase, and expression of several target genes of these peptides also change. Four key genes in innate immunity can be induced by infection in diapausing flies, and two of these, drosomycin and cecropin A1, are upregulated by diapause independently of infection. Diapausing flies display very low mortality, extended lifespan and decreased aging of the intestinal epithelium. Many phenotypes induced by diapause are reversed after one week of recovery from diapause conditions. Furthermore, mutant flies lacking specific insulin-like peptides (dilp5 and dilp2-3) display increased diapause incidence. Our study provides a first comprehensive characterization of reproductive diapause in D. melanogaster, and evidence that glucagon- and insulin-like signaling are among the key regulators of the altered physiology during this dormancy. PMID:25393614

  17. The Entomopathogenic Fungal Endophytes Purpureocillium lilacinum (Formerly Paecilomyces lilacinus) and Beauveria bassiana Negatively Affect Cotton Aphid Reproduction under Both Greenhouse and Field Conditions

    PubMed Central

    Castillo Lopez, Diana; Zhu-Salzman, Keyan; Ek-Ramos, Maria Julissa; Sword, Gregory A.

    2014-01-01

    The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus), were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae), through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum) were inoculated as seed treatments with two concentrations of B. bassiana or P. lilacinum conidia. Positive colonization of cotton by the endophytes was confirmed through potato dextrose agar (PDA) media plating and PCR analysis. Inoculation and colonization of cotton by either B. bassiana or P. lilacinum negatively affected aphid reproduction over periods of seven and 14 days in a series of greenhouse trials. Field trials were conducted in the summers of 2012 and 2013 in which cotton plants inoculated as seed treatments with B. bassiana and P. lilacinum were exposed to cotton aphids for 14 days. There was a significant overall effect of endophyte treatment on the number of cotton aphids per plant. Plants inoculated with B. bassiana had significantly lower numbers of aphids across both years. The number of aphids on plants inoculated with P. lilacinum exhibited a similar, but non-significant, reduction in numbers relative to control plants. We also tested the pathogenicity of both P. lilacinum and B. bassiana strains used in the experiments against cotton aphids in a survival experiment where 60% and 57% of treated aphids, respectively, died from infection over seven days versus 10% mortality among control insects. Our results demonstrate (i) the successful establishment of P. lilacinum and B. bassiana as endophytes in cotton via seed inoculation, (ii) subsequent negative effects of the presence of both target endophytes on cotton aphid reproduction using whole plant assays, and (iii) that the P. lilacinum strain used is both endophytic and pathogenic to cotton aphids. Our results illustrate the potential of using these

  18. Factors affecting post-flight behavior in primary reproductives of the Formosan subterranean termite, Coptotermes formosanus (Isoptera: Rhinotermitidae).

    PubMed

    Park, Yong Ihl; Bland, John M; Raina, Ashok K

    2004-06-01

    After swarming, reproductive dealates of the Formosan subterranean termite, Coptotermes formosanus, run together in tandem. The tandem running is an age-related behavioral activity in C. formosanus. This behavior was not evoked in pre-flight alates less than 6-d-old that were artificially dealated. Female age was more important than male age for evoking tandem behavior. Females and males, older than 35 days, did not exhibit this behavior. Mating status was not important for female and male dealates to form the tandem pairs. The titers of the major tergal gland component, trilinolein, did not decline significantly and remained high, not only in virgin females, but also in mated females for a period of time after swarming. On the other hand, increasing amounts of the female-specific compound trilinolein were detected in male dealates 7, 14, and 42 days after pairing. This suggests that trilinolein in the females might be transferred to the males as a nuptial gift in C. formosanus. In addition, females have structurally different lateral setae that may constitute a morphological factor involved in the tandem behavior in this species. Covering the setae with dimethyl sulfoxide prevented the tandem behavior. PMID:15183283

  19. Factors Affecting the Reproduction, Recruitment, Habitat, and Population Dynamics of Pallid Sturgeon and Shovelnose Sturgeon in the Missouri River

    USGS Publications Warehouse

    Korschgen, Carl E., (Edited By)

    2007-01-01

    For more than a hundred years, human activities have modified the natural forces that control the Missouri River and its native fish fauna. While the ecological effects of regulation and channel engineering are understood in general, the current understanding is not sufficient to guide river restoration and management. The U.S. Geological Survey (USGS) is in the third year of a multiagency research effort to determine the ecological requirements for reproduction and survival of the endangered pallid sturgeon (Scaphirhynchus albus) and shovelnose sturgeon (Scaphirhynchus platorhynchus) in the Missouri River. The multidisciplinary research strategy includes components of behavior, physiology, habitat use, habitat availability, and population modeling of all life stages. Shovelnose sturgeon are used to design the strategy because they are closely related to the pallid sturgeon and are often used as a surrogate species to develop new research tools or to examine the effects of management actions or environmental variables on sturgeon biology and habitat use. During fiscal years 2005 and 2006, the U.S. Army Corps of Engineers (USACE) provided funds to USGS for tasks associated with the Comprehensive Sturgeon Research Program (CSRP) and for tasks associated with evaluation of the Sturgeon Response to Flow Modifications (SRFM). Because work activities of CSRP and SRFM are so integrated, we are providing information on activities that have been consolidated at the task level. These task activities represent chapters in this report.

  20. Solanum tuberosum and Lycopersicon esculentum Leaf Extracts and Single Metabolites Affect Development and Reproduction of Drosophila melanogaster.

    PubMed

    Ventrella, Emanuela; Adamski, Zbigniew; Chudzińska, Ewa; Miądowicz-Kobielska, Mariola; Marciniak, Paweł; Büyükgüzel, Ender; Büyükgüzel, Kemal; Erdem, Meltem; Falabella, Patrizia; Scrano, Laura; Bufo, Sabino Aurelio

    2016-01-01

    Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids α-solanine, α-chaconine and α-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed) generation, addition of each extract reduced the number of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture. PMID:27213896

  1. Solanum tuberosum and Lycopersicon esculentum Leaf Extracts and Single Metabolites Affect Development and Reproduction of Drosophila melanogaster

    PubMed Central

    Ventrella, Emanuela; Adamski, Zbigniew; Chudzińska, Ewa; Miądowicz-Kobielska, Mariola; Marciniak, Paweł; Büyükgüzel, Ender; Büyükgüzel, Kemal; Erdem, Meltem; Falabella, Patrizia; Scrano, Laura; Bufo, Sabino Aurelio

    2016-01-01

    Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids α-solanine, α-chaconine and α-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed) generation, addition of each extract reduced the number of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture. PMID:27213896

  2. Dietary vitamin A, ascorbic acid and α-tocopherol affect the gonad development and reproductive performance of starry flounder Platichthys stellatus broodstock

    NASA Astrophysics Data System (ADS)

    Wang, Jiying; Li, Baoshan; Liu, Xudong; Ma, Jingjing; Wang, Shixin; Zhang, Limin

    2014-03-01

    The present trial was conducted with starry flounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A, ascorbic acid, and α-tocopherol on the gonadal development and reproductive performance. 8 000 IU/kg diet vitamin A (VA group), 500 mg/kg diet ascorbic acid (Vcpp group), or 250 mg/kg diet α-tocopherol (α-TA group) was added into basal diet to create 3 vitamin experimental diets, respectively. Each diet was fed to 450 starry flounder broodstock for 104 days. Samples were collected weekly. The gonadosomatic index (GSI) of 3 vitamin experimental groups first decreased and then increased. Maximum GSI of Vcpp group was higher than that of α-TA group but lower than that of VA group. The spawning periods of 3 vitamin experimental groups lasted 49, 56, and 45 days, respectively. No mature eggs were observed in the control group during the trial. The absolute fecundity (AF) and relative fecundity (RF) of α-TA group was higher than that of Vcpp group but lower than that of VA group. The results suggest that different vitamins play different roles in the fish reproductive process. Vitamin A stimulated the maturation of the ovary, ascorbic acid prolonged the spawning period, and α-tocopherol affected the development of the eggs.

  3. Conditional deletion of the relaxin receptor gene in cells of smooth muscle lineage affects lower reproductive tract in pregnant mice.

    PubMed

    Kaftanovskaya, Elena M; Huang, Zaohua; Lopez, Carolina; Conrad, Kirk; Agoulnik, Alexander I

    2015-04-01

    Relaxin hormone secreted into the circulation during pregnancy was discovered through its effects on pubic symphysis relaxation and parturition. Genetic inactivation of the relaxin gene or its cognate relaxin family peptide receptor 1 (RXFP1) in mice caused failure of parturition and mammary nipple enlargement, as well as increased collagen fiber density in the cervix and vagina. However, the relaxin effect on discrete cells and tissues has yet to be determined. Using transgenic mice with a knockin LacZ reporter in the Rxfp1 allele, we showed strong expression of this gene in vaginal and cervical stromal cells, as well as pubic ligament cells. We produced a floxed Rxfp1 allele that was used in combination with the Tagln-cre transgene to generate mice with a smooth muscle-specific gene knockout. In pregnant females, the ROSA26 reporter activated by Tagln-cre was detected in smooth muscle cells of the cervix, vagina, uterine artery, and in cells of the pubic symphysis. In late pregnant females with conditional gene ablation, the length of pubic symphysis was significantly reduced compared with wild-type or heterozygous Rxfp1(+/-) females. Denser collagen content was revealed by Masson trichrome staining in reproductive tract organs, uterine artery, and pubic symphysis. The cervical and vaginal epithelium was less developed than in heterozygous or wild-type females, although nipple size was normal and the dams were able to nurse their pups. In summary, our data indicate that relaxin/RXFP1 signaling in smooth muscle cells is important for normal collagen turnover and relaxation of the pubic symphysis during pregnancy. PMID:25715795

  4. The affective (re)production of refugee representations through educational policies and practices: Reconceptualising the role of emotion for peace education in a divided country

    NASA Astrophysics Data System (ADS)

    Zembylas, Michalinos

    2012-08-01

    Drawing into a discussion of the politicisation of emotion, this paper develops a framework to analyse some of the processes and strategies by which educational policies and pedagogical practices "emotionalise" the representation of refugees in conflict-ridden societies such as Cyprus and explores the implications for peace education. In particular, this paper aims to refine our understanding of how emotions affect the ways in which educational policies and practices reproduce self-other dichotomies through certain representations of the refugee experience. It is argued that these dichotomies are relevant to the emotional reactions against peace education initiatives. Second, this paper examines alternative possibilities of promoting peaceful coexistence, while taking into consideration the affective (re)production of refugee representations yet without undermining the refugee experience. Better understanding of how emotion is involved will help educational policymakers and teachers in divided societies to take into account the hitherto poorly developed aspects of the ways in which emotions, the refugee experience and peace education are inextricably intertwined.

  5. Peri-pubertal administration of 3-nitro-1,2,4-triazol-5-one (NTO) affects reproductive organ development in male but not female Sprague Dawley rats.

    PubMed

    Lent, Emily May; Crouse, Lee C B; Wallace, Shannon M; Carroll, Erica E

    2015-11-01

    Nitrotriazolone (3-nitro-1,2,4-triazol-5-one; NTO) is an insensitive munition that has demonstrated effects on reproductive organs in adult male rats. NTO was administered to male (0, 250, and 500milligrams per kilogram per day (mg/kg-day)) and female (0, 500, and 1000mg/kg-day) Sprague-Dawley rats (15/sex/group) via oral gavage from weaning through post-natal day 53/54 and 42/43, respectively. Age and body mass at vaginal opening (VO) and preputial separation (PPS), as well as all measures of estrous cyclicity were not affected by treatment with NTO. Males treated with NTO exhibited reductions in testis mass associated with tubular degeneration/atrophy. Less pronounced reductions in accessory sex organ masses were also observed in the 500mg/kg-day group. Treatment with NTO did not affect thyroid hormone or testosterone levels. These findings suggest that NTO is not acting as an estrogen or thyroid active compound, but may indicate effects on steroidogenesis and/or direct testicular toxicity. PMID:25962730

  6. Metals and female reproductive toxicity.

    PubMed

    Sengupta, P; Banerjee, R; Nath, S; Das, S; Banerjee, S

    2015-07-01

    Research into occupational exposure of metals and consequences of reproductive systems has made imperative scientific offerings in the preceding few decades. Early research works focused on possible effects on the reproductive functions rather than the complete reproductive health of the woman. Later, it was realized that metals, as reproductive toxins, may also induce hormonal changes affecting other facets of reproductive health such as the menstrual cycle, ovulation, and fertility. Concern is now shifting from considerations for the pregnant woman to the entire spectrum of occupational health threats and thus reproductive health among women. PMID:25425549

  7. Increased CO2 stimulates reproduction in a coral reef fish.

    PubMed

    Miller, Gabrielle M; Watson, Sue-Ann; McCormick, Mark I; Munday, Philip L

    2013-10-01

    Ocean acidification is predicted to negatively impact the reproduction of many marine species, either by reducing fertilization success or diverting energy from reproductive effort. While recent studies have demonstrated how ocean acidification will affect larval and juvenile fishes, little is known about how increasing partial pressure of carbon dioxide (pCO(2)) and decreasing pH might affect reproduction in adult fishes. We investigated the effects of near-future levels of pCO(2) on the reproductive performance of the cinnamon anemonefish, Amphiprion melanopus, from the Great Barrier Reef, Australia. Breeding pairs were held under three CO(2) treatments [Current-day Control (430 μatm), Moderate (584 μatm) and High (1032 μatm)] for a 9-month period that included the summer breeding season. Unexpectedly, increased CO(2) dramatically stimulated breeding activity in this species of fish. Over twice as many pairs bred in the Moderate (67% of pairs) and High (55%) compared to the Control (27%) CO(2) treatment. Pairs in the High CO(2) group produced double the number of clutches per pair and 67% more eggs per clutch compared to the Moderate and Control groups. As a result, reproductive output in the High group was 82% higher than that in the Control group and 50% higher than that in the Moderate group. Despite the increase in reproductive activity, there was no difference in adult body condition among the three treatment groups. There was no significant difference in hatchling length between the treatment groups, but larvae from the High CO(2) group had smaller yolks than Controls. This study provides the first evidence of the potential effects of ocean acidification on key reproductive attributes of marine fishes and, contrary to expectations, demonstrates an initially stimulatory (hormetic) effect in response to increased pCO(2). However, any long-term consequences of increased reproductive effort on individuals or populations remain to be determined. PMID:23686937

  8. Southern rice black-streaked dwarf virus (SRBSDV) directly affects the feeding and reproduction behavior of its vector, Sogatella furcifera (Horváth) (Hemiptera: Delphacidae)

    PubMed Central

    2014-01-01

    Background Southern rice black-streaked dwarf virus (SRBSDV) is a recently discovered member of the genus Fijivirus and it is transmitted by the rice whitebacked planthopper (WBPH), Sogatella furcifera (Horváth). It was found that SRBSDV infected vectors might contribute negatively to the WBPH population, although the longer nymphal period might benefit viral acquisition, transmission and increase infection rate. The interaction between SRBSDV and its vector need to be further explored to gain better understanding of the dispersal of WBPH and the spread of virus disease, in particular the feeding and reproduction behavior of viruliferous WBPH. Methods Newly hatched nymphs of WBPH were fed on healthy rice plant after feeding on SRBSDV-infected rice plants for 2 h, and newly emerged adults were numbered and tested. Feeding behaviors of WBPH adults were monitored electronically within a Faraday cage using a Giga-4 DC EPG amplifier. The newly emerged adults were paired, and the fecundity and egg hatchability were investigated. WBPH was molecularly identified for SRBSDV when they dead. According to the identification results, data on viruliferous and non-viruliferous WBPH were collected and analyzed. Results Feeding behavior of viruliferous WBPH was different from those of non-viruliferous WBPH. Frequency of phloem sap ingestion of viruliferous WBPH increased significantly, however the total feeding duration did not increase markedly. When both WBPH parents were infected with SRBSDV, their fecundity and hatchability of the eggs produced were significant lower than those of normal WBPH parents. However, if only one of the parents was viruliferous, fecundity and egg hatchability were only slightly affected. Conclusions Viruliferous WBPH fed on the phloem more frequently than non-viruliferous WBPH and can thus contribute to virus transmission. When both vector parents are viruliferous fecundity and hatchability of the eggs were significantly reduced. However when only

  9. Growth performance and reproductive traits at first parity of New Zealand white female rabbits as affected by heat stress and its alleviation under Egyptian conditions.

    PubMed

    Marai, I F; Ayyat, M S; Abd el-Monem, U M

    2001-12-01

    Exposing growing and adult New Zealand White (NZW) female rabbits to severe heat stress (temperature-humidity index = 28.9) during summer adversely affected their growth and reproductive traits. The traits that declined significantly (p < 0.01) were the live body weight, daily weight gain and feed intake of growing rabbits, and the litter size and litter weight at weaning (p < 0.05) and the pre-weaning weight gain of pups (p < 0.01) for adult females. The conception rate declined considerably with heat stress. The declines in the values of the digestibility coefficients due to heat stress were 7.9% (p < 0.05) for dry matter (DM), 8.1% (p < 0.05) for crude protein (CP) and 1.0% for crude fibre (CF). The traits that increased significantly (p < 0.01) due to heat stress were water intake, water/feed ratio and rectal temperature in growing rabbits and pre-weaning mortality for adult females. Alleviation of heat stress in the growing and adult female NZW rabbits was more efficient with drinking cool water (10-15 degrees C; between 10:00 and 17:00) than with supplementation with palm oil (as a source of energy) or natural clay (as a natural enhancer to growth and milk production). Supplying the animals with cool drinking water gave the highest body weight and weight gain, conception rate, litter size and weight and digestibility coefficients for DM and CP and the lowest rectal temperature, respiration rate and pre-weaning mortality. The loss in rabbit production pertaining to heat stress estimated from the percentages of decline in conception rate x pre-weaning mortality x litter weight at weaning was 73.0%. The provision of cool water restored 11/12 of heat loss. PMID:11770200

  10. Incubation Patterns in a Central-Place Forager Affect Lifetime Reproductive Success: Scaling of Patterns from a Foraging Bout to a Lifetime

    PubMed Central

    Shoji, Akiko; Elliott, Kyle H.; Aris-Brosou, Stéphane; Crump, Doug; Gaston, Anthony J.

    2011-01-01

    Background Long-lived seabirds face a conflict between current and lifelong reproductive success. During incubation shifts, egg neglect is sometimes necessary to avoid starvation, but may compromise the current reproductive attempt. However, factors underlying this decision process are poorly understood. We focus on the ancient murrelet, Synthliboramphus antiquus, an alcid with exceptionally long incubation shift lengths, and test the impact of environmental factors on incubation shift length in relation to reproductive success. Methodology/Principal Findings Using an information theoretic approach, we show that incubation shift length was a strong predictor of reproductive success for ancient murrelets at Reef Island, Haida Gwaii, British Columbia, Canada during the 2007 and 2008 breeding seasons. The most important factors explaining an individual's shift length were egg size, wind speed and the length of the mate's previous shift. Wind speed and tide height were the two most important factors for determining foraging behavior, as measured by dive frequency and depth. Conclusions/Significance Our study demonstrates that (i) species-specific reproductive strategies interact with environmental conditions such as wind speed to form multiple incubation patterns and (ii) maintaining regular incubation shifts is an essential component of reproductive success. PMID:21423631

  11. Eating disorders and reproduction.

    PubMed

    Morgan, J F

    1999-05-01

    Eating disorders are common and characteristically affect young women at what would otherwise be their peak of reproductive functioning. Anorexia nervosa and bulimia nervosa impinge on reproduction both behaviourally and physiologically, with effects on menstruation, ovarian function, fertility, sexuality and pregnancy. This review presents a summary of current knowledge and makes suggestions for future research, along with some clinical recommendations for the management of eating disorders in pregnancy. PMID:10755771

  12. Reproductive hacking. A male seminal protein acts through intact reproductive pathways in female Drosophila.

    PubMed

    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. PMID:25483253

  13. Breeding and Housing Laboratory Rats and Mice in the Same Room Does Not Affect the Growth or Reproduction of Either Species

    PubMed Central

    Pritchett-Corning, Kathleen R; Chang, Fon T; Festing, Michael F W

    2009-01-01

    Few data exist regarding the effects of long-term housing of rats and mice in the same secondary enclosure. Historical reproductive and growth data were compared for colonies of mice and rats maintained in open-topped cages in either single-species or dual-species barrier rooms. This analysis included reproductive parameters (litter size at birth, litter size at weaning, and pups missing at weaning) collected from 33 colonies of mice comprising 500 to 38,500 breeding females and 28 colonies of rats totaling 350 to 4,600 breeding females, and representative samples from 28 colonies of each species were analyzed for weight gain from weaning to adulthood. The presence or absence of the other species was not associated with statistically significant differences in weight gain or any of the reproductive parameters. These results suggest that breeding colonies of rats and mice of the same health status can be housed in the same room without a negative effect on the growth and reproduction of either species. PMID:19807969

  14. “I Always Worry about What Might Happen Ahead”: Implementing Safer Conception Services in the Current Environment of Reproductive Counseling for HIV-Affected Men and Women in Uganda

    PubMed Central

    Bajunirwe, Francis; Kastner, Jasmine; Sanyu, Naomi; Akatukwasa, Cecilia; Ng, Courtney; Rifkin, Rachel; Milford, Cecilia; Moore, Lizzie; Wilson, Ira B.; Bangsberg, David R.; Smit, Jennifer A.; Kaida, Angela

    2016-01-01

    Background. We explored healthcare provider perspectives and practices regarding safer conception counseling for HIV-affected clients. Methods. We conducted semistructured interviews with 38 providers (medical and clinical officers, nurses, peer counselors, and village health workers) delivering care to HIV-infected clients across 5 healthcare centres in Mbarara District, Uganda. Interview transcripts were analyzed using content analysis. Results. Of 38 providers, 76% were women with median age 34 years (range 24–57). First, we discuss providers' reproductive counseling practices. Emergent themes include that providers (1) assess reproductive goals of HIV-infected female clients frequently, but infrequently for male clients; (2) offer counseling focused on “family planning” and maternal and child health; (3) empathize with the importance of having children for HIV-affected clients; and (4) describe opportunities to counsel HIV-serodiscordant couples. Second, we discuss provider-level challenges that impede safer conception counseling. Emergent themes included the following: (1) providers struggle to translate reproductive rights language into individualized risk reduction given concerns about maternal health and HIV transmission and (2) providers lack safer conception training and support needed to provide counseling. Discussion. Tailored guidelines and training are required for providers to implement safer conception counseling. Such support must respond to provider experiences with adverse HIV-related maternal and child outcomes and a national emphasis on pregnancy prevention. PMID:27051664

  15. Spring Temperatures Alter Reproductive Development in Grapevines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate variation contributes to fluctuations in reproductive output, and spring temperature is thought to influence flower production in grapevines. We studied the influence of temperature near budburst on reproductive development in field-grown Cabernet Sauvignon while minimizing the influence of ...

  16. Human reproductive issues in space

    NASA Technical Reports Server (NTRS)

    Santy, Patricia A.; Jennings, Richard T.

    1992-01-01

    A review of reproductive functioning in animal species studied during space flight demonstrated that most species were affected significantly by the absence of gravity and/or the presence of radiation. These two factors induced alterations in normal reproductive functioning independently of, as well as in combination with, each other. Based on animal models, several potential problem areas regarding human reproductive physiology and functioning in the space environment were identified. While there are no current space flight investigations, the animal studies suggest priorities for future research in human reproduction. Such studies will be critical for the successful colonization of the space frontier.

  17. Reproductive and Locomotory Capacities of Caenorhabditis elegans Were Not Affected by Simulated Variable Gravities and Spaceflight During the Shenzhou-8 Mission

    PubMed Central

    Qiao, Liang; Luo, Sang; Liu, Yongding; Li, Xiaoyan

    2013-01-01

    Abstract Reproduction and locomotion are essential features of animals that help to facilitate their interaction with the surrounding environment. Previous studies have produced inconsistent results on behavioral response to spaceflight by the model animal Caenorhabditis elegans (C. elegans) in liquid culture. Using standard agar-based nematode growth medium (NGM), we show here that both reproductive and locomotory capacities of C. elegans were not significantly changed by centrifuge-produced hypergravity or clinostat-simulated microgravity. To investigate the effect of actual spaceflight on C. elegans, a nematode test unit was specifically designed to maintain its normal growth on solid NGM slides and to allow automatic RNA fixation on board the Shenzhou-8 spaceflight. We did not detect alteration in either brood size of immediate progenies from postflight nematodes or locomotory behavior, including speed of locomotion, frequency of reversals, and rate of body bends of space-flown nematodes collected directly from nematode test units. Our results provide clear evidence that the nematode test unit is an appropriate apparatus for nematode growth on standard NGM and can be used for on-orbit analysis of C. elegans, including onboard RNA fixation for molecular analysis and real-time video acquisition for behavioral analysis, which are critical for further studies in unmanned spaceflight and outer space exploration. Key Words: Spaceflight—Hypergravity—Microgravity—Caenorhabditis elegans—Behavior—Reproduction. Astrobiology 13, 617–625. PMID:23837604

  18. VARIATIONS IN REPRODUCTIVE TOXICANT IDENTIFICATION

    SciTech Connect

    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.

  19. Increase in male reproductive success and female reproductive investment in invasive populations of the harlequin ladybird Harmonia axyridis.

    PubMed

    Laugier, Guillaume J M; Le Moguédec, Gilles; Tayeh, Ashraf; Loiseau, Anne; Osawa, Naoya; Estoup, Arnaud; Facon, Benoît

    2013-01-01

    Reproductive strategy affects population dynamics and genetic parameters that can, in turn, affect evolutionary processes during the course of biological invasion. Life-history traits associated with reproductive strategy are therefore potentially good candidates for rapid evolutionary shifts during invasions. In a series of mating trials, we examined mixed groups of four males from invasive and native populations of the harlequin ladybird Harmonia axyridis mating freely during 48 hours with one female of either type. We recorded the identity of the first male to copulate and after the 48 h-period, we examined female fecundity and share of paternity, using molecular markers. We found that invasive populations have a different profile of male and female reproductive output. Males from invasive populations are more likely to mate first and gain a higher proportion of offspring with both invasive and native females. Females from invasive populations reproduce sooner, lay more eggs, and have offspring sired by a larger number of fathers than females from native populations. We found no evidence of direct inbreeding avoidance behaviour in both invasive and native females. This study highlights the importance of investigating evolutionary changes in reproductive strategy and associated traits during biological invasions. PMID:24204741

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

    PubMed

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

    2016-02-01

    Interactions between animals and their environment are fundamental to ecological research. Field studies of coyote (Canis latrans) reproductive performance suggest mean litter size changes in response to prey abundance. However, this relationship has been assessed primarily by using carcasses collected from trappers. The objective of this study was to assess whether nutritional manipulation prior to mating affected reproduction in adult female coyotes. We examined the effects of caloric restriction during the 7 months prior to estrus on the reproductive rates of 11 captive female coyotes and the subsequent initial survival of pups through two reproductive cycles. This was a 2-year study with a cross-over design so each female was monitored for reproductive performance on each of the two diet treatments. We assessed the number of implantation scars, number of pups born, sex ratios of pups, average pup weight at birth and 2- and 6-weeks of age, and the survival rates between implantation and 2-weeks of age for two diet treatments. We found the mean number of implantation sites and pups whelped during a reproductive cycle was influenced by food-intake prior to conception. Additionally, we found evidence suggesting the effects of nutritional stress may persist for additional breeding cycles. We also provided evidence suggesting well-fed females tended to have more male pups. Understanding how environmental factors influence reproductive output may improve model predictions of coyote population dynamics. PMID:26763531

  1. Linking biomarkers to reproductive success of caged fathead minnows in streams with increasing urbanization.

    PubMed

    Crago, Jordan; Corsi, Steven R; Weber, Daniel; Bannerman, Roger; Klaper, Rebecca

    2011-03-01

    Reproductive and oxidative stress biomarkers have been recommended as tools to assess the health of aquatic organisms. Though validated in the laboratory, there are few studies that tie a change in gene expression to adverse reproductive or population outcomes in the field. This paper looked at 17 streams with varying degrees of urbanization to assess the use of biomarkers associated with reproduction or stress in predicting reproductive success of fathead minnows. In addition, the relationship between biomarkers and water quality measures in streams with varying degrees of urbanization was examined. Liver vitellogenin mRNA was correlated with reproduction within a period of 11d prior to sampling irrespective of habitat, but its correlation with egg output declined at 12d and beyond indicating its usefulness as a short-term biomarker but its limits as a biomarker of total reproductive output. Stress biomarkers such as glutathione S-transferase may be better correlated with factors affecting reproduction over a longer term. There was a significant correlation between GST mRNA and a variety of anthropogenic pollutants. There was also an inverse correlation between glutathione S-transferase and the amount of the watershed designated as wetland. Egg production over the 21-d was negatively correlated with the amount of urbanization and positively correlated to wetland habitats. This study supports the development of multiple biomarkers linking oxidative stress and other non-reproductive endpoints to changes in aquatic habitats will be useful for predicting the health of fish populations and identifying the environmental factors that may need mitigation for sustainable population management. PMID:21147497

  2. Linking biomarkers to reproductive success of caged fathead minnows in streams with increasing urbanization

    USGS Publications Warehouse

    Crago, J.; Corsi, S.R.; Weber, D.; Bannerman, R.; Klaper, R.

    2011-01-01

    Reproductive and oxidative stress biomarkers have been recommended as tools to assess the health of aquatic organisms. Though validated in the laboratory, there are few studies that tie a change in gene expression to adverse reproductive or population outcomes in the field. This paper looked at 17 streams with varying degrees of urbanization to assess the use of biomarkers associated with reproduction or stress in predicting reproductive success of fathead minnows. In addition, the relationship between biomarkers and water quality measures in streams with varying degrees of urbanization was examined. Liver vitellogenin mRNA was correlated with reproduction within a period of 11. d prior to sampling irrespective of habitat, but its correlation with egg output declined at 12. d and beyond indicating its usefulness as a short-term biomarker but its limits as a biomarker of total reproductive output. Stress biomarkers such as glutathione S-transferase may be better correlated with factors affecting reproduction over a longer term. There was a significant correlation between GST mRNA and a variety of anthropogenic pollutants. There was also an inverse correlation between glutathione S-transferase and the amount of the watershed designated as wetland. Egg production over the 21-d was negatively correlated with the amount of urbanization and positively correlated to wetland habitats. This study supports the development of multiple biomarkers linking oxidative stress and other non-reproductive endpoints to changes in aquatic habitats will be useful for predicting the health of fish populations and identifying the environmental factors that may need mitigation for sustainable population management. ?? 2010 Elsevier Ltd.

  3. Influence of diet and stress on reproductive hormones in Nigerian olive baboons.

    PubMed

    Lodge, E; Ross, C; Ortmann, S; MacLarnon, A M

    2013-09-15

    A female mammal's reproductive function and output are limited by the energy she is able to extract from her environment. Previous studies of the interrelationships between energetic circumstances and reproductive function in a variety of mammal species have produced varied results, which do not all support the common assumption that higher female reproductive hormone levels, specifically progesterone, indicate better ovarian function and greater reproductive potential, and are associated with lower energetic stress. In the present study faecal progesterone and glucocorticoid levels were assessed in two troops of olive baboons (Papio anubis) in the same population. They face similar ecological challenges, except that one troop crop-raids, potentially affecting its energetic intake and stress levels. The energy intake of individual females was assessed by combining detailed feeding observations with nutritional analysis of food samples. The crop-raiding troop experienced 50% higher energy intake rates and 50% lower glucocorticoid levels compared to the non-crop-raiding troop alongside substantially lower progesterone levels. This suggests that energetic stress is associated with elevated progesterone levels and may be the cause of the non-crop-raiding troop's lower reproductive output. By comparing groups which differ little, except in terms of food access, and also by directly assessing energy intake, our study addresses some of the design limitations of previous research investigating variation in progesterone levels and energetic stress. It therefore has the potential to contribute to greater understanding of the factors affecting differences in reproductive and stress hormone levels and reproductive function in mammals experiencing different energetic circumstances. PMID:23800561

  4. Effects of a mass mortality event on gorgonian reproduction

    NASA Astrophysics Data System (ADS)

    Linares, C.; Coma, R.; Zabala, M.

    2008-03-01

    The impact of a disturbance is normally measured in terms of its effects on adult mortality, whilst the less obvious impact on reproductive biology is generally ignored. Although previous studies have contributed to understanding the effects of a mass mortality of gorgonians in 1999 at NW Mediterranean Sea, none of them have considered its impact on reproduction. The goal of this study was to determine the impact of mass mortality events on the reproduction of the gorgonian Paramuricea clavata, and examine the effect of the damage 1 year (June 2000) and 2 years (June 2001) after the event. The reproductive parameters of female colonies were more affected than those of males. In female colonies that were moderately or severely damaged, the proportion of fertile polyps decreased by about 22-35%, whilst in the worst affected males there was only a 12% decrease. Female colonies showed a progressive decrease in gonadal biomass with increasing damage to a maximum reduction of 73-75% of oocyte production observed in colonies with >33% injury. In contrast, in males, the gonadal biomass decreased rapidly for colonies with 5% of injured surface, with a reduction in spermary production of 49-64%. The same pattern of decrease in gonadal output compared to the extent of the injury was observed in 2001, two years after the mass mortality event. This indicated that the observed pattern was a response to the extent of the injury rather than a direct effect of the event. These severe effects on the reproduction of the red gorgonian species have implications for the recovery of affected populations in the long-term. This study demonstrated that an evaluation of the impact over different demographic parameters is needed to understand all the consequences of these disturbances.

  5. Reproductive interference between animal species.

    PubMed

    Gröning, Julia; Hochkirch, Axel

    2008-09-01

    Although sexual interactions between species (reproductive interference) have been reported from a wide range of animal taxa, their potential for determining species coexistence is often disregarded. Here, we review evidence from laboratory and field studies illustrating that heterospecific sexual interactions are frequently associated with fitness loss and can have severe ecological and evolutionary consequences. We define reproductive interference as any kind of interspecific interaction during the process of mate acquisition that adversely affects the fitness of at least one of the species involved and that is caused by incomplete species recognition. We distinguish seven types of reproductive interference: signal jamming, heterospecific rivalry, misdirected courtship, heterospecific mating attempts, erroneous female choice, heterospecific mating, and hybridization. We then discuss the sex-specific costs of these types and highlight two typical features of reproductive interference: density-dependence and asymmetry. Similar to competition, reproductive interference can lead to displacement of one species (sexual exclusion), spatial, temporal, or habitat segregation, changes in life history parameters, and reproductive character displacement. In many cases, patterns of coexistence might be shaped by reproductive interference rather than by resource competition, as the presence of a few heterospecifics might substantially decrease reproductive success. Therefore, interspecific sexual interactions should receive more attention in ecological research. Reproductive interference has mainly been discussed in the context of invasive species or hybrid zones, whereas its influence on naturally-occurring sympatric species pairs has rarely been addressed. To improve our knowledge of the ecological significance of reproductive interference, findings from laboratory experiments should be validated in the field. Future studies should also focus on ecological mechanisms, such

  6. The restricted ovulator chicken strain: An oviparous vertebrate model of reproductive dysfunction caused by a gene defect affecting an oocyte-specific receptor

    PubMed Central

    Elkin, R.G.; Bauer, R.; Schneider, W.J.

    2012-01-01

    A unique non-laying strain of chickens with heritable hyperlipidemia and aortic atherosclerosis was first described in 1974. Subsequent work established that the phenotype results from a naturally occurring point mutation in the gene specifying the very low density lipoprotein (VLDL) receptor, a 95-kDa membrane protein which normally mediates the massive uptake of the main circulating hepatically-synthesized yolk precursors, VLDL and vitellogenin. As a result, hens of the mutant strain termed “restricted ovulator” (R/O) have approximately 5-fold elevations in circulating cholesterol and triglyceride concentrations compared with normal layers, and hepatic lipogenesis and cholesterogenesis are markedly attenuated due to feedback inhibition. R/O hens also exhibit hyperestrogenemia, hypoprogesteronemia, elevated circulating gonadotropins, and up-regulated pituitary progesterone receptor mRNA and isoforms. The ovaries of R/O hens are abnormal in that they lack a follicular hierarchy and contain many small preovulatory follicles of various colors, shapes, and sizes. However, since R/O hens occasionally lay eggs, it is possible that endocytic receptors other than the VLDL receptor may be able to facilitate oocyte growth and/or that yolk precursor uptake can occur via a nonspecific bulk process. A mammalian model of impaired fecundity with abnormal lipoprotein metabolism also has been described, but different mechanisms are likely responsible for its reproductive dysfunction. Nevertheless, as our understanding of the molecular physiology and biochemistry of avian oocyte growth continues to expand, in part due to studies of the R/O model, new analogies may emerge between avian and mammalian systems, which ultimately could help to answer important questions in reproductive biology. PMID:23123285

  7. Zebrafish (Danio rerio) as a possible bioindicator of epigenetic factors present in drinking water that may affect reproductive function: is chorion an issue?

    PubMed

    Martinez-Sales, M; García-Ximénez, F; Espinós, F J

    2015-06-01

    Emerging organic contaminants have been monitored in stream waters, raw and finished waters and wastewater effluents. Most of these contaminants, such as epigenetic substances, have been detected at very low levels. Unfortunately, their complete monitoring and/or removal are very difficult, given the increasing presence of new contaminants and due to analytical and economic considerations. For this reason, bioindicators are used as an alternative to monitor their presence. To this end, zebrafish is being used to assess certain contaminants in water quality studies. As our long-term aim is to determine if zebrafish (Danio rerio) can be used to detect environmental epigenetic factors in drinking waters with effects on human reproduction, an initial question is whether the chorion could interfere with the possible action of epigenetic factors in two reproductive events: genital ridge formation and migration of the primordial germ cells (PGCs) to these genital ridges. In the first experiment, we attempted to partially degrade the chorion of mid blastula transition (MBT) embryos with pronase, with acceptable survival rates at 5 days post fertilisation (dpf), with the group exposed for 15 min giving the best survival results. As denuded early embryos require a specific culture medium, in the next experiment embryo survival was evaluated when they were cultured up to 5 dpf in drinking waters from six different sources. Results showed a negative effect on embryo survival at 5 dpf from several waters but not in others, thus distorting the survival outcomes. These results suggest using embryos with the chorion intact from the outset when drinking waters from different sources are to be tested. PMID:24598355

  8. Molecular basis for regulating seasonal reproduction in vertebrates.

    PubMed

    Nishiwaki-Ohkawa, Taeko; Yoshimura, Takashi

    2016-06-01

    Animals that inhabit mid- to high-latitude regions exhibit various adaptive behaviors, such as migration, reproduction, molting and hibernation in response to seasonal cues. These adaptive behaviors are tightly regulated by seasonal changes in photoperiod, the relative day length vs night length. Recently, the regulatory pathway of seasonal reproduction has been elucidated using quail. In birds, deep brain photoreceptors receive and transmit light information to the pars tuberalis in the pituitary gland, which induces the secretion of thyroid-stimulating hormone. Thyroid-stimulating hormone locally activates thyroid hormone via induction of type 2 deiodinase in the mediobasal hypothalamus. Thyroid hormone then induces morphological changes in the terminals of neurons that express gonadotropin-releasing hormone and facilitates gonadotropin secretion from the pituitary gland. In mammals, light information is received by photoreceptors in the retina and neurally transmitted to the pineal gland, where it inhibits the synthesis and secretion of melatonin, which is crucial for seasonal reproduction. Importantly, the signaling pathway downstream of light detection and signaling is fully conserved between mammals and birds. In fish, the regulatory components of seasonal reproduction are integrated, from light detection to neuroendocrine output, in a fish-specific organ called the saccus vasculosus. Various physiological processes in humans are also influenced by seasonal environmental changes. The findings discussed herein may provide clues to addressing human diseases, such as seasonal affective disorder. PMID:27068698

  9. Interactions between parasitic infections and reproductive efficiency in sheep.

    PubMed

    Fthenakis, G C; Mavrogianni, V S; Gallidis, E; Papadopoulos, E

    2015-02-28

    This review article summarises the many reports in the literature, confirming that, in sheep, parasitic infections can adversely affect reproductive efficiency; examples, which refer to all parts of the reproductive cycle of sheep, are as follows: trichostrongylosis in ewe-lambs (which can lead to delayed attainment of puberty), myiosis of the prepuce (which can cause impediment of mating), chorioptic mange or trypanosomosis in rams (which can lead to testicular degeneration or azoospermia, respectively), trypanosomosis or sarcoptic mange in pre-conceptual ewes (which can lead to poor conception rates or reduced number of ovulations, respectively), toxoplasmosis or neosporosis in pregnant ewes (which are causes of abortion), trichostrongylosis or trematode infections in lactating ewes (which can cause reduction of milk yield and can be a risk factor for mastitis, respectively), cryptosporidiosis in newborn lambs (which can be a cause of deaths), coccidiosis in growing pre-weaned lambs (which can cause suboptimal growth rate). In other cases, the reproductive status of the animal can influence the parasitic infection; examples are as follows: the increase in faecal parasitic output during the peri-parturient period (as a consequence of the peri-parturient relaxation of immunity), the heavier trichostrongylid infections of twin lambs compared to lambs from single parities (as a consequence of developmental origin issues in twin lambs). All the above examples support the idea of presence of interactions between parasitic infections and reproductive efficiency in sheep. PMID:25577675

  10. Reproductive Biology and Its Impact on Body Size: Comparative Analysis of Mammalian, Avian and Dinosaurian Reproduction

    PubMed Central

    Werner, Jan; Griebeler, Eva Maria

    2011-01-01

    Janis and Carrano (1992) suggested that large dinosaurs might have faced a lower risk of extinction under ecological changes than similar-sized mammals because large dinosaurs had a higher potential reproductive output than similar-sized mammals (JC hypothesis). First, we tested the assumption underlying the JC hypothesis. We therefore analysed the potential reproductive output (reflected in clutch/litter size and annual offspring number) of extant terrestrial mammals and birds (as “dinosaur analogs”) and of extinct dinosaurs. With the exception of rodents, the differences in the reproductive output of similar-sized birds and mammals proposed by Janis and Carrano (1992) existed even at the level of single orders. Fossil dinosaur clutches were larger than litters of similar-sized mammals, and dinosaur clutch sizes were comparable to those of similar-sized birds. Because the extinction risk of extant species often correlates with a low reproductive output, the latter difference suggests a lower risk of population extinction in dinosaurs than in mammals. Second, we present a very simple, mathematical model that demonstrates the advantage of a high reproductive output underlying the JC hypothesis. It predicts that a species with a high reproductive output that usually faces very high juvenile mortalities will benefit more strongly in terms of population size from reduced juvenile mortalities (e.g., resulting from a stochastic reduction in population size) than a species with a low reproductive output that usually comprises low juvenile mortalities. Based on our results, we suggest that reproductive strategy could have contributed to the evolution of the exceptional gigantism seen in dinosaurs that does not exist in extant terrestrial mammals. Large dinosaurs, e.g., the sauropods, may have easily sustained populations of very large-bodied species over evolutionary time. PMID:22194835

  11. GnRH-agonist implantation of prepubertal male cats affects their reproductive performance and testicular LH receptor and FSH receptor expression.

    PubMed

    Mehl, N S; Khalid, M; Srisuwatanasagul, S; Swangchan-uthai, T; Sirivaidyapong, S

    2016-03-15

    This study was conducted to investigate the effect of GnRH-agonist implantation in prepubertal tomcats on sexual behavior, reproductive performance, and expression of testicular LH receptor (LHR) and FSH receptor (FSHR) and also to compare the testicular characteristics, LHR and FSHR expression between prepubertal and adult tomcats. In experiment 1, 3-month-old tomcats (n = 6/group) were either treated with or left without 4.7 mg deslorelin implants. Semen collection and evaluation were performed just before castration at 48 weeks after treatment; removed testes were analyzed for mRNA and protein expression of LHR and FSHR. We were able to collect semen from six non-treated cats, whereas in treated cats, semen was uncollectable. The results revealed that sexual behavior was absent in the implanted cats throughout the study period. Testicular volume was found to decrease from 30 weeks after treatment onward in the implanted cats compared to the controls (P < 0.05). Semen production was found only in non-implanted cats. Testicular tissue score, seminiferous tubule diameter, and LHR protein expression were found lower in the implanted cats (P < 0.05), but no differences were observed in mRNA expression of LHR and protein expression of FSHR between groups. The mRNA expression of FSHR was higher in the implanted (P < 0.05) compared to control cats. In experiment 2, testes from prepubertal (n = 6) and adult (n = 6) male cats were collected after castration and analyzed for mRNA and protein expression of LHR and FSHR. No differences were observed in the protein expression of LHR and FSHR between the two groups, whereas mRNA expression of FSHR was higher in prepubertal cats (P < 0.05). Testicular and epididymal weight, diameter of seminiferous tubules, and the testicular grade were higher in the adult compared to prepubertal cats (P < 0.05). In conclusion, deslorelin implants suppressed protein expression of LHR and enhanced mRNA expression of FSHR along with suppression

  12. REPRODUCTIVE DEVELOPMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Throughout history, humans have celebrated the beauty and fertility of flowering plants. In addition to their aesthetic appeal, flowers contain the reproductive organs of the plant and are therefore essential for sexual propagation of plant life. Our dependence on flowering is illustrated by the die...

  13. Female Reproductive System

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Female Reproductive System KidsHealth > For Teens > Female Reproductive System Print A ... and female reproductive systems. continue What Is the Female Reproductive System? Most species have two sexes: male and female. ...

  14. Reproductive Steroid Regulation of Mood and Behavior.

    PubMed

    Schiller, Crystal Edler; Johnson, Sarah L; Abate, Anna C; Rubinow, David R; Schmidt, Peter J

    2016-01-01

    In this article, we examine evidence supporting the role of reproductive steroids in the regulation of mood and behavior in women and the nature of that role. In the first half of the article, we review evidence for the following: (i) the reproductive system is designed to regulate behavior; (ii) from the subcellular to cellular to circuit to behavior, reproductive steroids are powerful neuroregulators; (iii) affective disorders are disorders of behavioral state; and (iv) reproductive steroids affect virtually every system implicated in the pathophysiology of depression. In the second half of the article, we discuss the diagnosis of the three reproductive endocrine-related mood disorders (premenstrual dysphoric disorder, postpartum depression, and perimenopausal depression) and present evidence supporting the relevance of reproductive steroids to these conditions. Existing evidence suggests that changes in reproductive steroid levels during specific reproductive states (i.e., the premenstrual phase of the menstrual cycle, pregnancy, parturition, and the menopause transition) trigger affective dysregulation in susceptible women, thus suggesting the etiopathogenic relevance of these hormonal changes in reproductive mood disorders. Understanding the source of individual susceptibility is critical to both preventing the onset of illness and developing novel, individualized treatments for reproductive-related affective dysregulation. © 2016 American Physiological Society. Compr Physiol 6:1135-1160, 2016e. PMID:27347888

  15. Conditional Deletion of the Relaxin Receptor Gene in Cells of Smooth Muscle Lineage Affects Lower Reproductive Tract in Pregnant Mice1

    PubMed Central

    Kaftanovskaya, Elena M.; Huang, Zaohua; Lopez, Carolina; Conrad, Kirk; Agoulnik, Alexander I.

    2015-01-01

    ABSTRACT Relaxin hormone secreted into the circulation during pregnancy was discovered through its effects on pubic symphysis relaxation and parturition. Genetic inactivation of the relaxin gene or its cognate relaxin family peptide receptor 1 (RXFP1) in mice caused failure of parturition and mammary nipple enlargement, as well as increased collagen fiber density in the cervix and vagina. However, the relaxin effect on discrete cells and tissues has yet to be determined. Using transgenic mice with a knockin LacZ reporter in the Rxfp1 allele, we showed strong expression of this gene in vaginal and cervical stromal cells, as well as pubic ligament cells. We produced a floxed Rxfp1 allele that was used in combination with the Tagln-cre transgene to generate mice with a smooth muscle-specific gene knockout. In pregnant females, the ROSA26 reporter activated by Tagln-cre was detected in smooth muscle cells of the cervix, vagina, uterine artery, and in cells of the pubic symphysis. In late pregnant females with conditional gene ablation, the length of pubic symphysis was significantly reduced compared with wild-type or heterozygous Rxfp1+/− females. Denser collagen content was revealed by Masson trichrome staining in reproductive tract organs, uterine artery, and pubic symphysis. The cervical and vaginal epithelium was less developed than in heterozygous or wild-type females, although nipple size was normal and the dams were able to nurse their pups. In summary, our data indicate that relaxin/RXFP1 signaling in smooth muscle cells is important for normal collagen turnover and relaxation of the pubic symphysis during pregnancy. PMID:25715795

  16. Blockage of the Neonatal Leptin Surge Affects the Gene Expression of Growth Factors, Glial Proteins, and Neuropeptides Involved in the Control of Metabolism and Reproduction in Peripubertal Male and Female Rats.

    PubMed

    Mela, Virginia; Díaz, Francisca; Lopez-Rodriguez, Ana Belen; Vázquez, María Jesús; Gertler, Arieh; Argente, Jesús; Tena-Sempere, Manuel; Viveros, María-Paz; Chowen, Julie A

    2015-07-01

    Leptin (Lep) is important in the development of neuroendocrine circuits involved in metabolic control. Because both Lep and metabolism influence pubertal development, we hypothesized that early changes in Lep signaling could also modulate hypothalamic (HT) systems involved in reproduction. We previously demonstrated that a single injection of a Lep antagonist (Antag) on postnatal day (PND)9, coincident with the neonatal Lep peak, induced sexually dimorphic modifications in trophic factors and markers of cell turnover and neuronal maturation in the HT on PND13. Here, our aim was to investigate whether the alterations induced by Lep antagonism persist into puberty. Accordingly, male and female rats were treated with a pegylated super Lep Antag from PND5 to PND9 and killed just before the normal appearance of external signs of puberty (PND33 in females and PND43 in males). There was no effect on body weight, but in males food intake increased, subcutaneous adipose tissue decreased and HT neuropeptide Y and Agouti-related peptide mRNA levels were reduced, with no effect in females. In both sexes, the Antag increased HT mRNA levels of the kisspeptin receptor, G protein-coupled recepter 54 (Gpr54). Expression of the Lep receptor, trophic factors, and glial markers were differently affected in the HT of peripubertal males and females. Lep production in adipose tissue was decreased in Antag-treated rats of both sexes, with production of other cytokines being differentially regulated between sexes. In conclusion, in addition to the long-term effects on metabolism, changes in neonatal Lep levels modifies factors involved in reproduction that could possibly affect sexual maturation. PMID:25856428

  17. Rethinking reproductive "tourism" as reproductive "exile".

    PubMed

    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. PMID:19249025

  18. Reproductive ecology of the seabob shrimp Xiphopenaeus kroyeri (Heller, 1862) in a coastal area of Southern Brazil

    NASA Astrophysics Data System (ADS)

    Grabowski, Raphael Cezar; Negreiros-Fransozo, Maria Lucia; Castilho, Antonio Leão

    2016-01-01

    The predictability of certain environmental factors that affect the life cycle of the seabob shrimp Xiphopenaeus kroyeri (Heller, 1862) was evaluated in a study of its reproductive biology in an area adjacent to Babitonga Bay, State of Santa Catarina, Brazil. Monthly sampling was conducted from July 2010 through June 2011 at depths of 5, 8, 11, 14, and 17 m. 76 004 individuals were obtained, with a pronounced peak in absolute abundance in austral autumn (34 208), coinciding with the annual closed season from March to May. Grain size composition of the sediment showed the closest relationship to the distribution of individuals (multiple linear regression, P <0.05), related to their burying habit. The observed correlations between the abundance of reproductive males (bearing spermatophores) and females with spent gonads (cross-correlation, P <0.05), and between reproductive males and reproductive females (with a 1-month lag) suggest that the peak of reproductive males preceded the peak of female ones. This result agrees with the pattern expected for females, which copulate in post-ecdysis (spent gonads). Spawning seemed to take place at greater depths, as evidenced by the concentration of reproductive females in these areas. The reproductive activities observed here confirm that this species follows a tropical/subtropical reproductive pattern, spawning continuously throughout the year, with the highest peaks in spring and autumn. The data indicate that the juvenile recruitment period observed in August-September resulted from the reproductive output noted in April-May. Additionally, the reproductive period recorded in November led to the juvenile peak observed in March-May.

  19. Inflammation in Reproductive Disorders

    PubMed Central

    Weiss, Gerson; Goldsmith, Laura T.; Taylor, Robert N.; Bellet, Dominique; Taylor, Hugh S.

    2011-01-01

    Inflammatory disorders account for a significant percentage of gynecologic disease, particularly in reproductive age women. Inflammation is a basic method by which we respond to infection, irritation, or injury. Inflammation is now recognized as a type of nonspecific immune response, either acute or chronic. In gynecology, inflammation leads to anatomic disorders primarily as a result of infectious disease; however inflammation can affect ovulation and hormone production as well as be associated with endometriosis. Similarly, immune cell trafficking is an important component of cyclic endometrial development in each menstrual cycle. These immune cells are required for endometrial function, producing a vast array of inflammatory cytokines. Inflammation alters endometrial receptivity, however it may also play a role in tissue repair and remodeling. Finally, inflammation affects the trophoblast and trophoblast—endometrial interaction. Some components of the immune response are required for optimal fertility and normal tissue remodeling. A better understanding of the necessary role of inflammation in reproduction will allow more rational and targeted treatment of inflammatory disorders in reproductive medicine. PMID:19208790

  20. Linear output nitinol engine

    SciTech Connect

    Banks, R.M.

    1986-01-14

    This patent describes a linear output nitinol engine consisting of a number of integrated communicating parts. The engine has an external support framework which is described in detail. The patent further describes a wire transport mechanism, a pair of linkage levers with a loom secured to them, a number of nitinol wires strung between the looms, and a power takeoff block secured to the linkage levers. A pulley positioned in a flip-flop supporting bracket and a power takeoff modality including a tension member connected to a power output cable in order to provide linear power output transmission is described. A method for biasing the timing and the mechanism for timing the synchronization of the throw over arms and the flip-flop of the pulley are also described.

  1. Vertebrate Reproduction.

    PubMed

    Kornbluth, Sally; Fissore, Rafael

    2015-10-01

    Vertebrate reproduction requires a myriad of precisely orchestrated events-in particular, the maternal production of oocytes, the paternal production of sperm, successful fertilization, and initiation of early embryonic cell divisions. These processes are governed by a host of signaling pathways. Protein kinase and phosphatase signaling pathways involving Mos, CDK1, RSK, and PP2A regulate meiosis during maturation of the oocyte. Steroid signals-specifically testosterone-regulate spermatogenesis, as does signaling by G-protein-coupled hormone receptors. Finally, calcium signaling is essential for both sperm motility and fertilization. Altogether, this signaling symphony ensures the production of viable offspring, offering a chance of genetic immortality. PMID:26430215

  2. Reproductive efficiency of a Mediterranean endemic zooxanthellate coral decreases with increasing temperature along a wide latitudinal gradient.

    PubMed

    Airi, Valentina; Gizzi, Francesca; Falini, Giuseppe; Levy, Oren; Dubinsky, Zvy; Goffredo, Stefano

    2014-01-01

    Investments at the organismal level towards reproduction and growth are often used as indicators of health. Understanding how such energy allocation varies with environmental conditions may, therefore, aid in predicting possible responses to global climatic change in the near future. For example, variations in seawater temperature may alter the physiological functioning, behavior, reproductive output and demographic traits (e.g., productivity) of marine organisms, leading to shifts in the structure, spatial range, and abundance of populations. This study investigated variations in reproductive output associated with local seawater temperature along a wide latitudinal gradient on the western Italian coast, in the zooxanthellate Mediterranean coral, Balanophyllia europaea. Reproductive potential varied significantly among sites, where B. europaea individuals from the warmest site experienced loss of oocytes during gametogenesis. Most of the early oocytes from warmest sites did not reach maturity, possibly due to inhibition of metabolic processes at high temperatures, causing B. europaea to reabsorb the oocytes and utilize them as energy for other vital functions. In a progressively warming Mediterranean, the efficiency of the energy invested in reproduction could be considerably reduced in this species, thereby affecting vital processes. Given the projected increase in seawater temperature as a consequence of global climate change, the present study adds evidence to the threats posed by high temperatures to the survival of B. europaea in the next decades. PMID:24618568

  3. Reproductive Efficiency of a Mediterranean Endemic Zooxanthellate Coral Decreases with Increasing Temperature along a Wide Latitudinal Gradient

    PubMed Central

    Airi, Valentina; Gizzi, Francesca; Falini, Giuseppe; Levy, Oren; Dubinsky, Zvy; Goffredo, Stefano

    2014-01-01

    Investments at the organismal level towards reproduction and growth are often used as indicators of health. Understanding how such energy allocation varies with environmental conditions may, therefore, aid in predicting possible responses to global climatic change in the near future. For example, variations in seawater temperature may alter the physiological functioning, behavior, reproductive output and demographic traits (e.g., productivity) of marine organisms, leading to shifts in the structure, spatial range, and abundance of populations. This study investigated variations in reproductive output associated with local seawater temperature along a wide latitudinal gradient on the western Italian coast, in the zooxanthellate Mediterranean coral, Balanophyllia europaea. Reproductive potential varied significantly among sites, where B. europaea individuals from the warmest site experienced loss of oocytes during gametogenesis. Most of the early oocytes from warmest sites did not reach maturity, possibly due to inhibition of metabolic processes at high temperatures, causing B. europaea to reabsorb the oocytes and utilize them as energy for other vital functions. In a progressively warming Mediterranean, the efficiency of the energy invested in reproduction could be considerably reduced in this species, thereby affecting vital processes. Given the projected increase in seawater temperature as a consequence of global climate change, the present study adds evidence to the threats posed by high temperatures to the survival of B. europaea in the next decades. PMID:24618568

  4. Factors influencing reproductive performance of northern bobwhite in South Florida

    USGS Publications Warehouse

    Rolland, V.; Hostetler, J.A.; Hines, T.C.; Percival, H.F.; Oli, M.K.

    2011-01-01

    Reproductive success is a critical component of individual fitness, and also an important determinant of growth rates of populations characterized by early maturity and high fecundity. We used radiotelemetry data collected during 2003-2008 to estimate reproductive parameters in a declining northern bobwhite (Colinus virginianus) population in South Florida, and to test hypotheses regarding factors influencing these parameters. The overall clutch size was 12.10 ?? 0.22, but females laid more eggs in their first clutch (12.43 ?? 0.24) than in subsequent clutches (10.19 ?? 0.53) within a nesting season. Daily nest survival was higher for first (0.966 ?? 0.003) than subsequent nests (0.936 ?? 0.011). Hatchability (proportion of laid eggs that hatched conditional upon nest survival to hatching) was 0.853 ?? 0.008, but was higher for nests incubated by females (0.873 ?? 0.009) than those incubated by males (0.798 ?? 0.018). The proportion of individuals attempting a second nest was 0.112 ?? 0.024 and 0.281 ?? 0.040 when the first nest was successful and failed, respectively. Hatchability was lower when the nesting habitat was burned the previous winter. We found no evidence that food strip density (a management practice to provide supplemental food) influenced any of the reproductive parameters. Mean summer temperature affected hatchability, nest survival, and proportion of nests incubated by males. Overall, the reproductive output in our study population was lower than that reported for most other bobwhite populations, indicating that low reproductive performance may have contributed to bobwhite population declines in our study site. These results suggest that current management practices, particularly those related to habitat and harvest management, need careful evaluation. ?? 2010 Springer-Verlag.

  5. Is reproductive ageing controlled by the brain?

    PubMed

    Gore, Andrea C

    2007-08-01

    Female reproductive function is controlled by complex interactions of the brain, pituitary gland and ovary. Each of these organs produces unique hormones, and each hormone acts upon the other organs to affect a response. Differentiating the causes and the consequences of reproductive senescence in mammals is thus a 'chicken and egg' puzzle. Surprisingly, recent evidence indicates a more important role for the brain in the initiation and transition to reproductive senescence. PMID:17620108

  6. Diodes stabilize LED output

    NASA Technical Reports Server (NTRS)

    Deters, R. A.

    1977-01-01

    Small-signal diodes are placed in series with light-emitting diodes (LED's) to stabilize LED output against temperature fluctuations. Simple inexpensive method compensates for thermal fluctuations over a broad temperature range. Requiring few components, technique is particularly useful where circuit-board space is limited.

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

    PubMed Central

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

    2007-01-01

    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. PMID:17251099

  8. Do recent US Supreme Court rulings on patenting of genes and genetic diagnostics affect the practice of genetic screening and diagnosis in prenatal and reproductive care?

    PubMed Central

    Chandrasekharan, Subhashini; McGuire, Amy L.; Van den Veyver, Ignatia B.

    2015-01-01

    Thousands of patents have been awarded that claim human gene sequences and their uses, and some have been challenged in court. In a recent high-profile case, Association for Molecular Pathology, et al. vs. Myriad Genetics, Inc., et al., the United States Supreme Court ruled that genes are natural occurring substances and therefore not patentable through “composition of matter” claims. The consequences of this ruling will extend well beyond ending Myriad's monopoly over BRCA testing, and may affect similar monopolies of other commercial laboratories for tests involving other genes. It could also simplify intellectual property issues surrounding genome-wide clinical sequencing, which can generate results for genes covered by intellectual property. Non-invasive prenatal testing (NIPT) for common aneuploidies using cell-free fetal (cff) DNA in maternal blood is currently offered through commercial laboratories and is also the subject of ongoing patent litigation. The recent Supreme Court decision in the Myriad case has already been invoked by a lower district court in NIPT litigation and resulted in invalidation of primary claims in a patent on currently marketed cffDNA-based testing for chromosomal aneuploidies. PMID:24989832

  9. Do recent US Supreme Court rulings on patenting of genes and genetic diagnostics affect the practice of genetic screening and diagnosis in prenatal and reproductive care?

    PubMed

    Chandrasekharan, Subhashini; McGuire, Amy L; Van den Veyver, Ignatia B

    2014-10-01

    Thousands of patents have been awarded that claim human gene sequences and their uses, and some have been challenged in court. In a recent high-profile case, Association for Molecular Pathology, et al. v. Myriad Genetics, Inc., et al., the US Supreme Court ruled that genes are natural occurring substances and therefore not patentable through 'composition of matter' claims. The consequences of this ruling will extend well beyond ending Myriad's monopoly over BRCA testing and may affect similar monopolies of other commercial laboratories for tests involving other genes. It could also simplify intellectual property issues surrounding genome-wide clinical sequencing, which can generate results for genes covered by intellectual property. Non-invasive prenatal testing (NIPT) for common aneuploidies using cell-free fetal (cff) DNA in maternal blood is currently offered through commercial laboratories and is also the subject of ongoing patent litigation. The recent Supreme Court decision in the Myriad case has already been invoked by a lower district court in NIPT litigation and resulted in invalidation of primary claims in a patent on currently marketed cffDNA-based testing for chromosomal aneuploidies. PMID:24989832

  10. Reproduction, physiology and biochemistry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Male Reproductive System

    MedlinePlus

    ... gamete, the egg or ovum , meet in the female's reproductive system to create a new individual. Both the male and female reproductive systems are essential for reproduction. Humans, like other organisms, ...

  12. Male Reproductive System

    MedlinePlus

    ... gamete, the egg or ovum, meet in the female's reproductive system to create a baby. Both the male and female reproductive systems are essential for reproduction. Humans pass certain characteristics ...

  13. Normal Female Reproductive Anatomy

    MedlinePlus

    ... hyphen, e.g. -historical Searches are case-insensitive Reproductive System, Female, Anatomy Add to My Pictures View /Download : Small: ... Reproductive System, Female, Anatomy Description: Anatomy of the female reproductive system; drawing shows the uterus, myometrium (muscular outer layer ...

  14. Female Reproductive System

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Female Reproductive System KidsHealth > For Parents > Female Reproductive System Print A ... the egg or sperm. continue Components of the Female Reproductive System Unlike the male, the human female has a ...

  15. Hypoxaemia affects male reproduction: a case study of how to differentiate between primary and secondary hypoxic testicular toxicity due to chemical exposure.

    PubMed

    Bomhard, Ernst M; Gelbke, Heinz-Peter

    2013-07-01

    Classification for fertility is based on two conditions, namely on evidence of an adverse effect on sexual function and fertility and that the effect is not secondary to other toxic effects. To decide on an adverse effect is a relatively simple day-to-day decision in toxicology but whether this effect is secondary often leads to serious controversy. As the seminiferous epithelium operates on the verge of hypoxia, oxygen deficit can lead to secondary impairment of testicular function. This is well known from healthy mountaineers exposing themselves to high altitude. They have reduced blood oxygen content that goes in parallel with impairment of testicular function and this effect remains for some time in spite of a compensatory polycythaemia. Similar findings are described for experimental animals exposed to hypobaric oxygen/high altitude. In addition, testicular function is affected in severe diseases in humans associated with systemic oxygen deficit like chronic obstructive pulmonary disease, sickle cell disease or beta-thalassaemia as well as in transgenic animals simulating haemolytic anaemia or sickle cell disease. The problem of insufficient oxygen supply as the underlying cause for testicular impairment has received relatively little attention in toxicology, mainly because blood oxygen content is generally not measured in these animal experiments. The difficulties associated with the decision whether testicular toxicity is primary or secondary to hypoxia are exemplified by the results of inhalation studies with nickel subsulphide and gallium arsenide (GaAs). Both of these particulate substances lead to severe lung toxicity that might impair oxygen uptake, but testicular toxicity is only observed with GaAs. This may first be explained by different effects on the blood: nickel subsulphide inhalation leads to a compensatory erythropoiesis that may mitigate pulmonary lack of oxygen uptake. In contrast, GaAs exposure is associated with microcytic haemolytic

  16. Shrub spatial aggregation and consequences for reproductive success.

    PubMed

    Tirado, Reyes; Pugnaire, Francisco I

    2003-07-01

    To link spatial patterns and ecological processes, we analysed the distribution of two shrub species (one large and dominant, the other smaller) and estimated the reproductive consequences of their distribution for the smaller species. We tested the significance of the spatial distribution pattern of the two shrubs by second-order bivariate point pattern analysis (Ripley's K function). Performance of Asparagus albus, the smaller shrub, was measured as (1) survival of transplanted seedlings in two contrasting habitats: patches of the dominant shrub (Ziziphus lotus), and open interspaces; and (2) reproductive output of plants naturally occurring in both habitats. The two species were significantly aggregated. Transplanted Asparagus albus seedlings had higher survival rates in patches than in the open. Plants produced more flowers, fruits, and showed a higher mass of seeds when living in aggregates than when isolated. The mechanisms responsible for this facilitative effect seem to be related to soil enrichment in patches. These results suggest that the spatial aggregation of species can be indicative of a positive interaction among them, directly affecting fitness of at least one of the species. Facilitation, by inducing variations in the reproductive performance may play a major role in the demography and dynamics of plant populations. PMID:12695906

  17. Climate Model Output Rewriter

    SciTech Connect

    Taylor, K. E.; Doutriaux, C.

    2004-06-21

    CMOR comprises a set of FORTRAN 90 dunctions that can be used to produce CF-compliant netCDF files. The structure of the files created by CMOR and the metadata they contain fulfill the requirements of many of the climate community’s standard model experiments (which are referred to here as "MIPS", which stands for "model intercomparison project", including, for example, AMIP, CMIP, CFMIP, PMIP, APE, and IPCC scenario runs), CMOR was not designed to serve as an all-purpose wfiter of CF-compliant netCDF files, but simply to reduce the effort required to prepare and manage MIP data. Although MIPs encourage systematic analysis of results across models, this is only easy to do if the model output is written in a common format with files structured similarly and with sufficient metadata uniformly stored according to a common standard. Individual modeling groups store their data in different ways. but if a group can read its own data with FORTRAN, then it should easily be able to transform the data, using CMOR, into the common format required by the MIPs, The adoption of CMOR as a standard code for exchanging climate data will facilitate participation in MIPs because after learning how to satisfy the output requirements of one MIP, it will be easy to prepare output for the other MIPs.

  18. Climate Model Output Rewriter

    2004-06-21

    CMOR comprises a set of FORTRAN 90 dunctions that can be used to produce CF-compliant netCDF files. The structure of the files created by CMOR and the metadata they contain fulfill the requirements of many of the climate community’s standard model experiments (which are referred to here as "MIPS", which stands for "model intercomparison project", including, for example, AMIP, CMIP, CFMIP, PMIP, APE, and IPCC scenario runs), CMOR was not designed to serve as anmore » all-purpose wfiter of CF-compliant netCDF files, but simply to reduce the effort required to prepare and manage MIP data. Although MIPs encourage systematic analysis of results across models, this is only easy to do if the model output is written in a common format with files structured similarly and with sufficient metadata uniformly stored according to a common standard. Individual modeling groups store their data in different ways. but if a group can read its own data with FORTRAN, then it should easily be able to transform the data, using CMOR, into the common format required by the MIPs, The adoption of CMOR as a standard code for exchanging climate data will facilitate participation in MIPs because after learning how to satisfy the output requirements of one MIP, it will be easy to prepare output for the other MIPs.« less

  19. Porcine Reproductive and Respiratory Syndrome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Porcine reproductive and respiratory syndrome (PRRS) first appeared in the late 1980s, though serologic evidence indicates that it had been circulating in swine for some time prior to being recognized. PRRS has since become a highly significant infectious disease affecting swine production worldwid...

  20. A missing model in reproductive skew theory: the bordered tug-of-war.

    PubMed

    Reeve, Hudson Kern; Shen, Sheng-Feng

    2006-05-30

    Models of reproductive skew can be classified into two groups: transactional models, in which group members yield shares of reproduction to each other in return for cooperation, and tug-of-war models, in which group members invest group resources in a tug-of-war over their respective reproductive shares. We synthesize these two models to yield a "bordered tug-of-war" model in which the internal tug-of-war is limited ("bordered") by the requirement that group members must achieve a certain amount of reproduction lest they pursue a noncooperative option leading to group breakup. Previous attempts to synthesize these two models did not allow for the fact that the tug-of-war will affect group output, which in turn feeds back on the reproductive payments required by group members to remain cooperative. The bordered tug-of-war model, which does not assume complete reproductive control by any individual and allows for conflict within groups, predicts that the degree of within-group selfishness will increase as the noncooperative options become less attractive, e.g., as ecological constraints on solitary breeding increase. When the noncooperative option involves fighting for the group resource (e.g., territory) and leaving if the fight is lost, the subordinate's overall share of reproduction is predicted to be independent of its relatedness to the dominant and to increase the greater its probability of winning the fight, the less the value of the territory, and the greater its personal payoff for leaving. The unique predictions of the bordered tug-of-war model may fit skew data from a number of species, including meerkats, lions, and wood mice. PMID:16717185

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  2. Reproductive Issues in Women with Turner Syndrome.

    PubMed

    Folsom, Lisal J; Fuqua, John S

    2015-12-01

    Turner syndrome is one of the most common chromosomal abnormalities affecting female infants. The severity of clinical manifestations varies and it affects multiple organ systems. Women with Turner syndrome have a 3-fold increase in mortality, which becomes even more pronounced in pregnancy. Reproductive options include adoption or surrogacy, assisted reproductive techniques, and in rare cases spontaneous pregnancy. Risks for women with Turner syndrome during pregnancy include aortic disorders, hepatic disease, thyroid disease, type 2 diabetes, and cesarean section delivery. Providers must be familiar with the risks and recommendations in caring for women with Turner syndrome of reproductive age. PMID:26568488

  3. Coral reproduction in Western Australia

    PubMed Central

    Speed, Conrad W.; Babcock, Russ

    2016-01-01

    the full moon. The timing of the full moon determined whether spawning was split over two months, which was common on tropical reefs. There were few data available for non-Acropora corals, which may have different patterns of reproduction. For example, the massive Porites seemed to spawn through spring to autumn on Kimberley Oceanic reefs and during summer in the Pilbara region, where other common corals (e.g. Turbinaria & Pavona) also displayed different patterns of reproduction to the Acropora. The brooding corals (Isopora & Seriatopora) on Kimberley Oceanic reefs appeared to planulate during many months, possibly with peaks from spring to autumn; a similar pattern is likely on other WA reefs. Gaps in knowledge were also due to the difficulty in identifying species and issues with methodology. We briefly discuss some of these issues and suggest an approach to quantifying variation in reproductive output throughout a year. PMID:27231651

  4. Coral reproduction in Western Australia.

    PubMed

    Gilmour, James; Speed, Conrad W; Babcock, Russ

    2016-01-01

    full moon. The timing of the full moon determined whether spawning was split over two months, which was common on tropical reefs. There were few data available for non-Acropora corals, which may have different patterns of reproduction. For example, the massive Porites seemed to spawn through spring to autumn on Kimberley Oceanic reefs and during summer in the Pilbara region, where other common corals (e.g. Turbinaria & Pavona) also displayed different patterns of reproduction to the Acropora. The brooding corals (Isopora & Seriatopora) on Kimberley Oceanic reefs appeared to planulate during many months, possibly with peaks from spring to autumn; a similar pattern is likely on other WA reefs. Gaps in knowledge were also due to the difficulty in identifying species and issues with methodology. We briefly discuss some of these issues and suggest an approach to quantifying variation in reproductive output throughout a year. PMID:27231651

  5. Reproductive toxicity: Male and female reproductive systems as targets for chemical injury

    SciTech Connect

    Mattison, D.R.; Plowchalk, D.R.; Meadows, M.J.; Al-Juburi, A.Z.; Gandy, J.; Malek, A. )

    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.

  6. Reproductive health care delivery.

    PubMed

    Lindgren, Mark C; Ross, Lawrence S

    2014-02-01

    Most patients in the United States with reproductive health disorders are not covered by their health insurance for these problems. Health insurance plans consider reproductive care as a lifestyle choice not as a disease. If coverage is provided it is, most often, directed to female factor infertility and advanced reproductive techniques, ignoring male factor reproductive disorders. This article reviews the history of reproductive health care delivery and its present state, and considers its possible future direction. PMID:24286778

  7. QTL architecture of reproductive fitness characters in Brassica rapa

    PubMed Central

    2014-01-01

    Background Reproductive output is critical to both agronomists seeking to increase seed yield and to evolutionary biologists interested in understanding natural selection. We examine the genetic architecture of diverse reproductive fitness traits in recombinant inbred lines (RILs) developed from a crop (seed oil) × wild-like (rapid cycling) genotype of Brassica rapa in field and greenhouse environments. Results Several fitness traits showed strong correlations and QTL-colocalization across environments (days to bolting, fruit length and seed color). Total fruit number was uncorrelated across environments and most QTL affecting this trait were correspondingly environment-specific. Most fitness components were positively correlated, consistent with life-history theory that genotypic variation in resource acquisition masks tradeoffs. Finally, we detected evidence of transgenerational pleiotropy, that is, maternal days to bolting was negatively correlated with days to offspring germination. A QTL for this transgenerational correlation was mapped to a genomic region harboring one copy of FLOWERING LOCUS C, a genetic locus known to affect both days to flowering as well as germination phenotypes. Conclusions This study characterizes the genetic structure of important fitness/yield traits within and between generations in B. rapa. Several identified QTL are suitable candidates for fine-mapping for the improvement of yield in crop Brassicas. Specifically, brFLC1, warrants further investigation as a potential regulator of phenology between generations. PMID:24641198

  8. Mammalian reproduction: an ecological perspective.

    PubMed

    Bronson, F H

    1985-02-01

    The objectives of this paper are to organize our concepts about the environmental regulation of reproduction in mammals and to delineate important gaps in our knowledge of this subject. The environmental factors of major importance for mammalian reproduction are food availability, ambient temperature, rainfall, the day/night cycle and a variety of social cues. The synthesis offered here uses as its core the bioenergetic control of reproduction. Thus, for example, annual patterns of breeding are viewed as reflecting primarily the caloric costs of the female's reproductive effort as they relate to the energetic costs and gains associated with her foraging effort. Body size of the female is an important consideration since it is correlated with both potential fat reserves and life span. Variation in nutrient availability may or may not be an important consideration. The evolutionary forces that have shaped the breeding success of males usually are fundamentally different from those acting on females and, by implication, the environmental controls governing reproduction probably also often differ either qualitatively or quantitatively in the two sexes. Mammals often live in habitats where energetic and nutrient challenges vary seasonally, even in the tropics. When seasonal breeding is required, a mammal may use a predictor such as photoperiod or a secondary plant compound to prepare metabolically for reproduction. A reasonable argument can be made, however, that opportunistic breeding, unenforced by a predictor, may be the most prevalent strategy extant among today's mammals. Social cues can have potent modulating actions. They can act either via discrete neural and endocrine pathways to alter specific processes such as ovulation, or they can induce nonspecific emotional states that secondarily affect reproduction. Many major gaps remain in our knowledge about the environmental regulation of mammalian reproduction. For one, we have a paucity of information about the

  9. Reproductive problems of the work force.

    PubMed

    Premalatha, G D; Ravindran, J

    2000-03-01

    The number of women in the workforce in increasing. A substantial proportion are in the reproductive age which brings to attention the problem of work exposures that adversely affect reproductive outcome. These exposures include chemicals, radiation, strenuous physical activity and infections. They affect reproduction by effect on the germ cells, through hormonal distribution which in turn affects transport of germ cells or zygote, implantation and development. Some of these exposures are teratogenic. At present, some regulations and policies seem to be directed at women workers while there is evidence to show that women are not the only victims. Paternal exposures have also been reported to be associated with infertility, spontaneous abortions and other adverse outcomes. There is insufficient information about reproductive effects of work exposures and hence further research is required in this area. PMID:11072503

  10. Society for Assisted Reproductive Technology

    MedlinePlus

    The Society for Assisted Reproductive Technology PATIENTS Patient Information What Is SART? Risks of IVF Third Party Reproduction A Patient's Guide to Assisted Reproductive Technology Frequently Asked ...

  11. Life-history tradeoffs and reproductive cycles in Spotted Owls

    USGS Publications Warehouse

    Stoelting, Ricka E.; Gutierrez, R.J.; Kendall, William; Peery, M. Zachariah

    2015-01-01

    The study of tradeoffs among life-history traits has long been key to understanding the evolution of life-history strategies. However, more recently, evolutionary ecologists have realized that reproductive costs have the potential to influence population dynamics. Here, we tested for costs of reproduction in the California Spotted Owl (Strix occidentalis occidentalis), and assessed whether costs of reproduction in year t − 1 on reproduction in year t could be responsible for regionally synchronized biennial cycles in reproductive output. Logistic regression analysis and multistate mark–recapture models with state uncertainty revealed that breeding reduced the likelihood of reproducing in the subsequent year by 16% to 38%, but had no influence on subsequent survival. We also found that costs of reproduction in year t − 1 were correlated with climatic conditions in year t, with evidence of higher costs during the dry phase of the El Niño–Southern Oscillation. Using a simulation-based population model, we showed that strong reproductive costs had the potential to create biennial cycles in population-level reproductive output; however, estimated costs of reproduction appeared to be too small to explain patterns observed in Spotted Owls. In the absence of strong reproductive costs, we hypothesize that observed natural cycles in the reproductive output of Spotted Owls are related to as-yet-unmeasured, regionally concordant fluctuations in environmental conditions or prey resources. Despite theoretical evidence for demographic effects, our analyses illustrate that linking tradeoffs to actual changes in population processes will be challenging because of the potential confounding effects of individual and environmental variation.

  12. Drosophila sperm motility in the reproductive tract.

    PubMed

    Yang, Yong; Lu, Xiangyi

    2011-05-01

    Motile cilia and flagella exhibit many waveforms as outputs of dynein activation sequences on the highly conserved axoneme. Motility change of sperm in the reproductive tract is difficult to study and remains an important area of investigation. Sperm typically execute a sinusoidal waveform. Increased viscosity in the medium induces somewhat unusual arc-line and helical waveforms in some sperm. However, whether the latter two waveforms occur in vivo is not known. Using green fluorescence protein imaging, we show that Drosophila sperm in the uterus move in circular foci via arc-line waves, predominantly in a tail-leading orientation. From the uterus, a small fraction of the sperm enters the seminal receptacle (SR) in parallel formations. After sperm storage and coincident with fertilization of the egg, the sperm exit the SR via head-leading helical waves. Consistent with the observed bidirectional movements, the sperm show the ability to propagate both base-to-tip and tip-to-base flagellar waves. Numerous studies have shown that sperm motility is regulated by intraflagellar calcium concentrations; in particular, the Pkd2 calcium channel has been shown to affect sperm storage. Our analyses here suggest that Pkd2 is required for the sperm to adopt the correct waveform and movement orientation during SR entry. A working model for the sperm's SR entry movement is proposed. PMID:21293028

  13. Reproductive Information and Reproductive Decision-Making.

    PubMed

    Mehlman, Maxwell J

    2015-01-01

    Opponents of reproductive choice are attempting to limit reproductive decisions based on certain underlying reasons. This commentary explores the rationales for these limitations and the objections to them. It concludes that reasoned-based limitations are unsupportable and unenforceable. PMID:26242944

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

    Grisham, Blake A.; Boal, Clint W.; Haukos, David A.; Davis, Dawn M.; 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 Niña 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.

  16. Male Reproductive System

    MedlinePlus

    ... Surveillance Modules » Anatomy & Physiology » Reproductive System » Male Reproductive System Cancer Registration & Surveillance Modules Anatomy & Physiology Intro to the Human Body Body Functions & Life Process Anatomical Terminology Review Quiz ...

  17. Men's Reproductive Health

    MedlinePlus

    ... NICHD Research Information Clinical Trials Resources and Publications Men's Reproductive Health: Overview Skip sharing on social media ... Content Reproductive health is an important component of men's overall health and well-being. Too often, males ...

  18. Reproductive tract microbiome in assisted reproductive technologies.

    PubMed

    Franasiak, Jason M; Scott, Richard T

    2015-12-01

    The human microbiome has gained much attention recently for its role in health and disease. This interest has come as we have begun to scratch the surface of the complexity of what has been deemed to be our "second genome" through initiatives such as the Human Microbiome Project. Microbes have been hypothesized to be involved in the physiology and pathophysiology of assisted reproduction since before the first success in IVF. Although the data supporting or refuting this hypothesis remain somewhat sparse, thanks to sequencing data from the 16S rRNA subunit, we have begun to characterize the microbiome in the male and female reproductive tracts and understand how this may play a role in reproductive competence. In this review, we discuss what is known about the microbiome of the reproductive tract as it pertains to assisted reproductive technologies. PMID:26597628

  19. Gender and social reproduction: historical perspectives.

    PubMed

    Laslett, B; Brenner, J

    1989-01-01

    It is argued that gender relations and social reproduction were both shaped by macrohistorical processes and shaped the processes. Social reproduction is defined within feminist theory as more than production in the Marxist sense. Societal reproduction is a combination of the organization of production, the organization of social reproduction, the perpetuation of gender, and the continuation of class relations. Social reproduction includes the care and socialization of children and care of the elderly or infirm. Social reproduction includes the organization of sexuality, biological reproduction, and how food, clothing, and shelter are made available. Most social reproduction occurs within the family unit. It is pointed out that variations in the distribution of the work of social reproduction are affected by the family, market, community, and state. The ways in which women construct their own worlds of activity is a central concern. The feminist concept of social reproduction differs from modernization theory, which is concerned with the institutional location of the tasks of social reproduction and the structural effects on the family and gender relations. This literature review focuses only on the history of family strategies and separate gender-related activities. The authors describe the changes in family organization that define men as income producers and women as caretakers, who base child rearing on love and feminine virtue rather than patriarchal authority and religious doctrine. The discussion focuses on the differences in marital relationships, motherhood, and sexuality between upper and middle class and working class women in the 19th century. Among working class women, a good wife was an efficient manager, a skilled domestic worker, and an income earner. The turn of the century was a period of social change marked by smaller average family size, the decline of household production, the rise in real wages, and increased consumption. It is argued that

  20. Serial Input Output

    SciTech Connect

    Waite, Anthony; /SLAC

    2011-09-07

    Serial Input/Output (SIO) is designed to be a long term storage format of a sophistication somewhere between simple ASCII files and the techniques provided by inter alia Objectivity and Root. The former tend to be low density, information lossy (floating point numbers lose precision) and inflexible. The latter require abstract descriptions of the data with all that that implies in terms of extra complexity. The basic building blocks of SIO are streams, records and blocks. Streams provide the connections between the program and files. The user can define an arbitrary list of streams as required. A given stream must be opened for either reading or writing. SIO does not support read/write streams. If a stream is closed during the execution of a program, it can be reopened in either read or write mode to the same or a different file. Records represent a coherent grouping of data. Records consist of a collection of blocks (see next paragraph). The user can define a variety of records (headers, events, error logs, etc.) and request that any of them be written to any stream. When SIO reads a file, it first decodes the record name and if that record has been defined and unpacking has been requested for it, SIO proceeds to unpack the blocks. Blocks are user provided objects which do the real work of reading/writing the data. The user is responsible for writing the code for these blocks and for identifying these blocks to SIO at run time. To write a collection of blocks, the user must first connect them to a record. The record can then be written to a stream as described above. Note that the same block can be connected to many different records. When SIO reads a record, it scans through the blocks written and calls the corresponding block object (if it has been defined) to decode it. Undefined blocks are skipped. Each of these categories (streams, records and blocks) have some characteristics in common. Every stream, record and block has a name with the condition that each

  1. Lightweight multiple output converter development

    NASA Technical Reports Server (NTRS)

    Kisch, J. J.; Martinelli, R. M.

    1978-01-01

    A high frequency, multiple output power conditioner was developed and breadboarded using an eight-stage capacitor diode voltage multiplier to provide +1200 Vdc, and a three-stage for -350 Vdc. In addition, two rectifier bridges were capacitively coupled to the eight-stage multiplier to obtain 0.5 and 0.65 a dc constant current outputs referenced to +1200 Vdc. Total power was 120 watts, with an overall efficiency of 85 percent at the 80 kHz operating frequency. All outputs were regulated to three percent or better, with complete short circuit protection. The power conditioner component weight and efficiency were compared to the equivalent four outputs of the 10 kHz conditioner for the 8 cm ion engine. Weight reduction for the four outputs was 557 grams; extrapolated in the same ratio to all nine outputs, it would be 1100 to 1400 grams.

  2. CMOS output buffer wave shaper

    NASA Technical Reports Server (NTRS)

    Albertson, L.; Whitaker, S.; Merrell, R.

    1990-01-01

    As the switching speeds and densities of Digital CMOS integrated circuits continue to increase, output switching noise becomes more of a problem. A design technique which aids in the reduction of switching noise is reported. The output driver stage is analyzed through the use of an equivalent RLC circuit. The results of the analysis are used in the design of an output driver stage. A test circuit based on these techniques is being submitted to MOSIS for fabrication.

  3. Nonlinear input-output systems

    NASA Technical Reports Server (NTRS)

    Hunt, L. R.; Luksic, Mladen; Su, Renjeng

    1987-01-01

    Necessary and sufficient conditions that the nonlinear system dot-x = f(x) + ug(x) and y = h(x) be locally feedback equivalent to the controllable linear system dot-xi = A xi + bv and y = C xi having linear output are found. Only the single input and single output case is considered, however, the results generalize to multi-input and multi-output systems.

  4. Reproductive hazards in the microelectronics industry

    SciTech Connect

    Rudolph, L.; Swan, S.H.

    1986-01-01

    There has been increased awareness of the potential for occupational and environmental exposures to hazardous substances to adversely affect reproductive outcome in men and women. The purpose of this article is to familiarize the clinician with some of the normal physiologic changes of pregnancy and how those may interact with working conditions in the electronics industry. It also reviews some of the data regarding potential reproductive hazards of substances and physical agents used in this industry. 11 references.

  5. Negative impacts of a vertebrate predator on insect pollinator visitation and seed output in Chuquiraga oppositifolia, a high Andean shrub.

    PubMed

    Muñoz, Alejandro A; Arroyo, Mary T K

    2004-01-01

    Studies on plant-pollinator interactions have largely neglected the potential negative effects of the predators of pollinators on seed output, even though anti-predatory behaviour of pollinators may affect visitation patterns, pollen transfer, and therefore potentially, plant reproductive output. We tested the hypothesis that the presence of lizards and insectivorous birds, by reducing pollinator visitation, can have significant negative effects on seed output in the insect-pollinated, genetically self-incompatible lower alpine Andean shrub, Chuquiraga oppositifolia (Asteraceae). The lower alpine belt supports a high density of territorial Liolaemus (Tropiduridae) lizards and low shrubs interspersed among rocks of varying sizes, the latter inhabited by lizards and commonly used by flycatchers Muscisaxicola (Tyrannidae) as perching sites. In a 2x2 factorial predator-exclusion experiment, visitation rates of the most frequent pollinators of C. oppositifolia (the satyrid butterfly Cosmosatyrus chilensis and the syrphid fly Scaeva melanostoma), the duration of pollinator visits, and seed output, were 2-4 times greater when lizards were excluded, while birds had no effect. In a natural experiment, visits by S. melanostoma were 9 times shorter, and pollinator visitation rates of C. chilensis and S. melanostoma, and C. oppositifolia seed output were 2-3 times lower on shrubs growing adjacent to lizard-occupied rocks compared to those growing distant from rocks. Our results, verified for additional Andean sites, suggest that lizard predators can alter the behaviour of pollinators and elicit strong top-down indirect negative effects on seed output. Such effects may be especially important in high alpine plant communities, where pollinator activity can be low and erratic, and pollen limitation has been reported. PMID:14551828

  6. Individual variation in reproductive costs of reproduction: high-quality females always do better.

    PubMed

    Hamel, Sandra; Côté, Steeve D; Gaillard, Jean-Michel; Festa-Bianchet, Marco

    2009-01-01

    1. Although life-history theory predicts substantial costs of reproduction, individuals often show positive correlations among life-history traits, rather than trade-offs. The apparent absence of reproductive costs may result from heterogeneity in individual quality. 2. Using detailed longitudinal data from three contrasted ungulate populations (mountain goats, Oreamnos americanus; bighorn sheep, Ovis canadensis; and roe deer, Capreolus capreolus), we assessed how individual quality affects the probability of detecting a cost of current reproduction on future reproduction for females. We used a composite measure of individual quality based on variations in longevity (all species), success in the last breeding opportunity before death (goats and sheep), adult mass (all species), and social rank (goats only). 3. In all species, high-quality females consistently had a higher probability of reproduction, irrespective of previous reproductive status. In mountain goats, we detected a cost of reproduction only after accounting for differences in individual quality. Only low-quality female goats were less likely to reproduce following years of breeding than of nonbreeding. Offspring survival was lower in bighorn ewes following years of successful breeding than after years when no lamb was produced, but only for low-quality females, suggesting that a cost of reproduction only occurred for low-quality females. 4. Because costs of reproduction differ among females, studies of life-history evolution must account for heterogeneity in individual quality. PMID:18700872

  7. Collector-Output Analysis Program

    NASA Technical Reports Server (NTRS)

    Glandorf, D. R.; Phillips, Robert F., II

    1986-01-01

    Collector-Output Analysis Program (COAP) programmer's aid for analyzing output produced by UNIVAC collector (MAP processor). COAP developed to aid in design of segmentation structures for programs with large memory requirements and numerous elements but of value in understanding relationships among components of any program. Crossreference indexes and supplemental information produced. COAP written in FORTRAN 77.

  8. Output from MHD Models

    NASA Astrophysics Data System (ADS)

    Vlahakis, Nektarios

    2010-03-01

    Outflows emanating from the environment of stellar or galactic objects are a widespread phenomenon in astrophysics. Their morphology ranges from nearly spherically symmetric winds to highly collimated jets. In some cases, e.g., in jets associated with young stellar objects, the bulk outflow speeds are nonrelativistic, while in others, e.g., in jets associated with active galactic nuclei or gamma-ray bursts, it can even be highly relativistic. The main driving mechanism of collimated outflows is likely related to magnetic fields. These fields are able to tap the rotational energy of the compact object or disk, accelerate, and collimate matter ejecta. To zeroth order these outflows can be described by the highly intractable theory of magnetohydrodynamics (MHD). Even in systems where the assumptions of zero resistivity (ideal MHD), steady state, axisymmetry, one fluid description, and polytropic equation of state are applicable, the problem remains difficult. In this case the problem reduces to only two equations, corresponding to the two components of the momentum equation along the flow and in the direction perpendicular to the magnetic field (transfield direction). The latter equation is the most difficult to solve, but also the most important. It answers the question on the degree of the collimation, but also crucially affects the solution of the first, the acceleration efficiency and the bulk velocity of the flow. The first and second parts of this chapter refer to nonrelativistic and relativistic flows, respectively. These Parts can be read independently. In each one, the governing equations are presented and discussed, focusing on the case of flows that are magnetically dominated near the central source. The general characteristics of the solutions in relation to the acceleration and collimation mechanisms are analyzed. As specific examples of exact solutions of the full system of the MHD equations that satisfy all the analyzed general characteristics, self

  9. Reproduction (II): Human Control of Reproductive Processes

    ERIC Educational Resources Information Center

    Jost, Alfred

    1970-01-01

    Describes methods of intervening in reproduction of animals and humans (artificial insemination, contraception, ovular and blastodisc transplants, pre selection of sex, cloning) and discusses the social implications of their use with humans. (AL)

  10. Molecular biology and reproduction.

    PubMed

    McDonough, P G

    1999-03-01

    Modern molecular biology has provided unique insights into the fundamental understanding of reproductive disorders and the detection of microorganisms. The remarkable advances in DNA diagnostics have been expedited by the development of polymerase chain reaction (PCR) and the ability to isolate DNA and RNA from many different sources such as blood, saliva, hair roots, microscopic slides, paraffin-embedded tissue sections, clinical swabs, and even cancellous bone. These technical advances have been bolstered by the development of an increasing number of effective screening techniques to scan genomic DNA for unknown point mutations. The continued development of technology will ultimately result in automated DNA (desoxyribonucleic acid) diagnosis for the practicing clinician. The continuing expansion of information concerning the human genome will place an increasing emphasis on bioinformatics and the use of computer software for analyzing DNA sequences. With the automation of DNA diagnosis and the use of small samples (500 nanograms), the direct examination of the DNA of a patient, fetus, or microorganism will emerge as a definitive means of establishing the presence of the specific genetic change that causes disease. A knowledge of the precise pathology at the molecular level has and will provide important insights into the biochemical basis for many human diseases. A firm knowledge of the DNA alterations in disease and expression patterns of specific genes will provide for more directed therapeutic strategies. The refinement of vector technology and nuclear transplantion techniques will provide the opportunity for directed gene therapy to the early human embryo. This presentation is designed to acquaint the reader with current techniques of testing at the DNA level, prototype mutations in the reproductive sciences, new concepts in the molecular mechanisms of disease that affect reproduction, and therapeutic opportunities for the future. It is hoped that future

  11. Enhanced performance CCD output amplifier

    DOEpatents

    Dunham, Mark E.; Morley, David W.

    1996-01-01

    A low-noise FET amplifier is connected to amplify output charge from a che coupled device (CCD). The FET has its gate connected to the CCD in common source configuration for receiving the output charge signal from the CCD and output an intermediate signal at a drain of the FET. An intermediate amplifier is connected to the drain of the FET for receiving the intermediate signal and outputting a low-noise signal functionally related to the output charge signal from the CCD. The amplifier is preferably connected as a virtual ground to the FET drain. The inherent shunt capacitance of the FET is selected to be at least equal to the sum of the remaining capacitances.

  12. Reproductive Resilience to Food Shortage in a Small Heterothermic Primate

    PubMed Central

    Perret, Martine; Henry, Pierre-Yves

    2012-01-01

    The massive energetic costs entailed by reproduction in most mammalian females may increase the vulnerability of reproductive success to food shortage. Unexpected events of unfavorable climatic conditions are expected to rise in frequency and intensity as climate changes. The extent to which physiological flexibility allows organisms to maintain reproductive output constant despite energetic bottlenecks has been poorly investigated. In mammals, reproductive resilience is predicted to be maximal during early stages of reproduction, due to the moderate energetic costs of ovulation and gestation relative to lactation. We experimentally tested the consequences of chronic-moderate and short-acute food shortages on the reproductive output of a small seasonally breeding primate, the grey mouse lemur (Microcebus murinus) under thermo-neutral conditions. These two food treatments were respectively designed to simulate the energetic constraints imposed by a lean year (40% caloric restriction over eight months) or by a sudden, severe climatic event occurring shortly before reproduction (80% caloric restriction over a month). Grey mouse lemurs evolved under the harsh, unpredictable climate of the dry forest of Madagascar and should thus display great potential for physiological adjustments to energetic bottlenecks. We assessed the resilience of the early stages of reproduction (mating success, fertility, and gestation) to these contrasted food treatments, and on the later stages (lactation and offspring growth) in response to the chronic food shortage only. Food deprived mouse lemurs managed to maintain constant most reproductive parameters, including oestrus timing, estrogenization level at oestrus, mating success, litter size, and litter mass as well as their overall number of surviving offspring at weaning. However, offspring growth was delayed in food restricted mothers. These results suggest that heterothermic, fattening-prone mammals display important reproductive

  13. [Reproductive toxicity of lindane].

    PubMed

    Pagès, Nicole; Sauviat, Martin-Pierre; Bouvet, Suzanne; Goudey-Perrière, Françoise

    2002-01-01

    The present paper bears on the main effects of lindane (gamma isomer of hexachlorocyclohexane) on endocrine and reproductive functions in mammals. This pesticide, once widely used to kill lice and a variety of pests that attack agricultural products, livestock and trees, has been progressively eliminated from many applications since the mid-1970s in Europe or USA, but is still used in the rest of the world. Lindane is absorbed through respiratory, digestive or cutaneous routes and accumulates in fat tissues. It damages human liver, kidney, neural and immune systems and induces birth defects, cancer and death. Chronic administration results in endocrine disruption in birds as well as in mammals. Treatment with 1-40 mg of lindane/kg b.w. disrupts testicular morphology, decreases spermatogenesis, inhibits testicular steroidogenesis, reduces plasma androgen concentrations and may adversely affect reproductive performances in males. In females, lindane disrupts the estrous cycle, reduces serum estrogen and progesterone levels, decreases sexual receptivity whereas in pregnant dams it decreases whelping rate and litter size. These effects were also observed in some rats exposed to residual environmental doses. In addition, there is concern that irreversible effects may be induced when animals are exposed to endocrine disrupting chemicals during critically susceptible phases of sexual differentiation or development. These effects would results from (i) alterations of gonade or gamete cell membranes (ii) cell metabolism changes including alterations of ionic exchanges (mainly calcium or potassium), direct or free radical-mediated inhibition of steroidogenesis (iii) or neuroendocrine changes leading to a decrease in sexual performance of either parents or their offsprings exposed in utero or through lactation. PMID:12645304

  14. Determinants of reproductive success in dominant female meerkats.

    PubMed

    Hodge, Sarah J; Manica, A; Flower, T P; Clutton-Brock, T H

    2008-01-01

    1. In cooperative societies with high reproductive skew, selection on females is likely to operate principally through variation in the probability of acquiring dominant status and variation in reproductive success while dominant. Despite this, few studies of cooperative societies have investigated the factors that influence which females become dominant, and/or their reproductive output while in the dominant position. 2. Here we use long-term data from a wild meerkats population to describe variation in the breeding success of dominant female meerkats Suricata suricatta and investigate its causes. 3. Female meerkats compete intensely for breeding positions, and the probability of acquiring the breeding role depends upon a female's age in relation to competitors and her weight, both at the time of dominance acquisition and early in life. 4. Once dominant, individual differences in breeding success depend principally on the duration of dominance tenure. Females remain for longer in the dominant position if they are heavier than their competitors at the start of dominance, and if the number of adult female competitors at the start is low. 5. Female breeding success is also affected by variation in fecundity and pup survival, both of which increase with group size. After controlling for these effects, female body weight has a positive influence on breeding rate and litter size, while the number of adult female competitors reduces litter survival. 6. These findings suggest that selection for body weight and competitive ability will be high in female meerkats, which may moderate their investment in cooperative activities. We suggest that similar consequences of competition may occur among females in other cooperative societies where the benefits of attaining dominance status are high. PMID:18031526

  15. Reproductive energy investment in corals: scaling with module size.

    PubMed

    Leuzinger, Sebastian; Anthony, Kenneth R N; Willis, Bette L

    2003-08-01

    In colonial modular organisms, differences in module size and colony growth patterns among species have the potential to impose varying constraints on reproductive investment. Here, we compare reproductive output among seven morphologically different species of spawning reef corals, and analyse the relationship between reproductive output and module (polyp) size. Reproductive output ranged between 132 and 384 J cm(-2), with lipid constituting the key indicator of energy investment. Lipid decreased by 85-100%, whereas protein and carbohydrate were relatively invariant between pre- and post-spawning tissues in all species, representing 1-15% and <1%, respectively, of the energy investment to reproductive output. The ratio of energy content in reproductive to somatic tissues (gonadosomatic index, GSI) varied among species from 0.20 (Symphyllia recta) to 1.31 (Acropora tenuis), the latter being the highest value reported for any iteroparous marine invertebrate. Surprisingly, small-polyped species (Acropora, Montipora) had 2- to 6-fold higher GSIs than large-polyped ones (Lobophyllia, Symphyllia). Energy equivalents of tissues increased with the 1.50-1.76 power of polyp diameter for somatic tissues and with the 1.42-1.80 power of polyp diameter for reproductive output. In both cases, increases in energy equivalents with polyp diameter were less than the scaling exponent of 3 predicted for an isometric relationship between tissue volume (or mass) and polyp diameter, indicating significant constraints of space, design or physiological energetics with increasing polyp size. We hypothesise that such constraints have played a key role in the evolution of modularity in cnidarians. PMID:12802676

  16. Influence of individual body size on reproductive traits in Melanopline grasshoppers (Orthoptera: Acrididae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Body size is a fundamental trait of an organism, affecting most aspects of its performance, including reproduction. Numerous biotic and environmental factors can influence individual body size and reproduction in grasshoppers. Using data from four experiments, I examined intraspecific relationships ...

  17. Early reproductive investment, senescence and lifetime reproductive success in female Asian elephants

    PubMed Central

    Hayward, A D; Mar, K U; Lahdenperä, M; Lummaa, V

    2014-01-01

    The evolutionary theory of senescence posits that as the probability of extrinsic mortality increases with age, selection should favour early-life over late-life reproduction. Studies on natural vertebrate populations show early reproduction may impair later-life performance, but the consequences for lifetime fitness have rarely been determined, and little is known of whether similar patterns apply to mammals which typically live for several decades. We used a longitudinal dataset on Asian elephants (Elephas maximus) to investigate associations between early-life reproduction and female age-specific survival, fecundity and offspring survival to independence, as well as lifetime breeding success (lifetime number of calves produced). Females showed low fecundity following sexual maturity, followed by a rapid increase to a peak at age 19 and a subsequent decline. High early life reproductive output (before the peak of performance) was positively associated with subsequent age-specific fecundity and offspring survival, but significantly impaired a female's own later-life survival. Despite the negative effects of early reproduction on late-life survival, early reproduction is under positive selection through a positive association with lifetime breeding success. Our results suggest a trade-off between early reproduction and later survival which is maintained by strong selection for high early fecundity, and thus support the prediction from life history theory that high investment in reproductive success in early life is favoured by selection through lifetime fitness despite costs to later-life survival. That maternal survival in elephants depends on previous reproductive investment also has implications for the success of (semi-)captive breeding programmes of this endangered species. PMID:24580655

  18. [Male reproductive toxicity of bisphenol A].

    PubMed

    Zhu, Wen-jiao; Qiao, Jie

    2015-11-01

    The reproductive toxicity of environmental endocrine disruptors has attracted substantial attention from researchers in recent years. Bisphenol A (BPA) is among the most prominent environmental estrogens worldwide, demonstrated to be related with the impairment of male reproductive function as well as other health problems, such as diabetes, obesity, cardiovascular diseases, and cancer. BPA acts primarily by mimicking antiandrogenic and estrogenic effects, disturbing the hypothalamic-pituitary-testicular axis and modulating gene expressions and enzyme activities in the hormone biosynthesis affecting steroids or its receptors. BPA is also involved in DNA methylation and the effects of epigenetics, resulting in dyszoospermia, oligoasthenoteratospermia/azoospermia and/or infertility in males. This review addresses the effects of BPA on male reproductive function, focusing on the mechanisms of its toxicity on spermatogenesis, semen quality, and the reproductive system. PMID:26738332

  19. Advances in reproductive biotechnologies.

    PubMed

    Choudhary, K K; Kavya, K M; Jerome, A; Sharma, R K

    2016-04-01

    In recent times, reproductive biotechnologies have emerged and started to replace the conventional techniques. It is noteworthy that for sustained livestock productivity, it is imperative to start using these techniques for facing the increasing challenges for productivity, reproduction and health with impending environment conditions. These recent biotechniques, both in male and female, have revolutionized and opened avenues for studying and manipulating the reproductive process both in vitro and in vivo in various livestock species for improving tis efficiency. This review attempts to highlight pros and cons, on the recent developments in reproductive biotechnologies, both in male and female in livestock species. PMID:27182135

  20. Advances in reproductive biotechnologies

    PubMed Central

    Choudhary, K. K.; Kavya, K. M.; Jerome, A.; Sharma, R. K.

    2016-01-01

    In recent times, reproductive biotechnologies have emerged and started to replace the conventional techniques. It is noteworthy that for sustained livestock productivity, it is imperative to start using these techniques for facing the increasing challenges for productivity, reproduction and health with impending environment conditions. These recent biotechniques, both in male and female, have revolutionized and opened avenues for studying and manipulating the reproductive process both in vitro and in vivo in various livestock species for improving tis efficiency. This review attempts to highlight pros and cons, on the recent developments in reproductive biotechnologies, both in male and female in livestock species. PMID:27182135

  1. Research on output feedback control

    NASA Technical Reports Server (NTRS)

    Calise, Anthony J.

    1988-01-01

    A summary is presented of the main results obtained during the course of research on output feedback control. The term output feedback is used to denote a controller design approach which does not rely on an observer to estimate the states of the system. Thus, the order of the controller is fixed, and can even be zero order, which amounts to constant gain ouput feedback. The emphasis has been on optimal output feedback. That is, a fixed order controller is designed based on minimizing a suitably chosen quadratic performance index. A number of problem areas that arise in this context have been addressed. These include developing suitable methods for selecting an index of performance, both time domain and frequency domain methods for achieving robustness of the closed loop system, developing canonical forms to achieve a minimal parameterization for the controller, two time scale design formulations for ill-conditioned systems, and the development of convergent numerical algorithms for solving the output feedback problem.

  2. Output optics for laser velocimeters

    NASA Technical Reports Server (NTRS)

    Lynch, Dana H. (Inventor); Gunter, William D. (Inventor); Mcalister, Kenneth W. (Inventor)

    1993-01-01

    Space savings are effected in the optical output system of a laser velocimeter. The output system is comprised of pairs of optical fibers having output ends from which a beam of laser light emerges, a transfer lens for each light beam, and at least one final (LV) lens for receiving the light passing through the transfer lenses and for focussing that light at a common crossing point or area. In order to closely couple the transfer lenses to the final lens, each transfer lens is positioned relative to the final lens receiving light therefrom such that the output waist of the corresponding beam received by the final lens from the transfer lens is a virtual waist located before the transfer lens.

  3. Reproductive partitioning and the assumptions of reproductive skew models in the cooperatively breeding American crow

    PubMed Central

    Townsend, Andrea K.; Clark, Anne B.; McGowan, Kevin J.; Lovette, Irby J.

    2009-01-01

    Understanding the benefits of cooperative breeding for group members of different social and demographic classes requires knowledge of their reproductive partitioning and genetic relatedness. From 2004-2007, we examined parentage as a function of relatedness and social interactions among members of 21 American crow (Corvus brachyrhynchos) family groups. Paired female breeders monopolized maternity of all offspring in their broods, whereas paired male breeders sired 82.7% of offspring, within-group auxiliary males sired 6.9% of offspring, and extragroup males sired 10.4% of offspring. Although adult females had fewer opportunities for direct reproduction as auxiliaries than males, they appeared to have earlier opportunities for independent breeding. These different opportunities for direct reproduction probably contributed to the male biased adult auxiliary sex ratio. Patterns of reproductive partitioning and conflict among males were most consistent with a synthetic reproductive skew model, in which auxiliaries struggled with breeders for a limited reproductive share, beyond which breeders could evict them. Counter to a frequent assumption of reproductive skew models, female breeders appeared to influence paternity, although their interests might have agreed with the interests of their paired males. Unusual among cooperative breeders, close inbreeding and incest occurred in this population. Incest avoidance between potential breeders did not significantly affect reproductive skew. PMID:20126287

  4. Sundangrass reproductive biomass responses under climate change scenarios in oak savannah and mesic prairie mesocosm communities

    EPA Science Inventory

    Potential climate change effects include shifts in the distribution of plant species and changes in reproductive output. We tested the hypothesis that environmental stressors such as elevated temperature and drought that are associated with climate change would increase the repr...

  5. The effect of atmospheric pressure on ventricular assist device output.

    PubMed

    Goto, Takeshi; Sato, Masaharu; Yamazaki, Akio; Fukuda, Wakako; Watanabe, Ken-Ichi; Daitoku, Kazuyuki; Minakawa, Masahito; Fukui, Kozo; Suzuki, Yasuyuki; Fukuda, Ikuo

    2012-03-01

    The effect of cabin pressure change on the respiratory system during flight is well documented in the literature, but how the change in atmospheric pressure affects ventricular assist device (VAD) output flow has not been studied yet. The purpose of our study was to evaluate the change in VAD output using a mock circulatory system in a low-pressure chamber mimicking high altitude. Changes in output and driving pressure were measured during decompression from 1.0 to 0.7 atm and pressurization from 0.7 to 1.0 atm. Two driving systems were evaluated: the VCT system and the Mobart system. In the VCT system, output and driving pressure remained the same during decompression and pressurization. In the Mobart system, the output decreased as the atmospheric pressure dropped and recovered during pressurization. The lowest output was observed at 0.7 atm, which was 80% of the baseline driven by the Mobart system. Under a practical cabin pressure of 0.8 atm, the output driven by the Mobart system was 90% of the baseline. In the Mobart system, the output decreased as the atmospheric pressure dropped, and recovered during pressurization. However, the decrease in output was slight. In an environment where the atmospheric pressure changes, it is necessary to monitor the diaphragmatic motion of the blood pump and the driving air pressure, and to adjust the systolic:diastolic ratio as well as the positive and negative pressures in a VAD system. PMID:21915797

  6. Sexual Reproduction and Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the second edition of Plant Propagation Concepts and Laboratory Exercises, we have combined the first edition chapters 36: Sexual Reproduction in Angiosperms and 37: Breeding Horticultural Plants into the present single chapter Sexual Reproduction and Breeding. These topics are so closely relate...

  7. CONTROL OF REPRODUCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Control of reproduction is important for seed stock production, selective breeding, growth rate, feed efficiency, meat quality, and biosecurity. These needs to control reproduction differ among cultivars and even segments of the same industry. No matter the impetus for aquaculturists to want to alte...

  8. Reproduction, Physiology and Biochemistry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter focuses on the reproduction, physiology, and biochemistry of the root-knot nematodes. The extensive amount of information on the reproduction and cytogenetics of species of Meloidogyne contrasts with the limited information on physiology, biochemistry, and biochemical pathways. In commo...

  9. Aerial photographic reproductions

    USGS Publications Warehouse

    U.S. Geological Survey

    1971-01-01

    Geological Survey vertical aerial photography is obtained primarily for topographic and geologic mapping. Reproductions from this photography are usually satisfactory for general use. Because reproductions are not stocked, but are custom processed for each order, they cannot be returned for credit or refund.

  10. The Reproduction of Intelligence

    ERIC Educational Resources Information Center

    Meisenberg, Gerhard

    2010-01-01

    Although a negative relationship between fertility and education has been described consistently in most countries of the world, less is known about the relationship between intelligence and reproductive outcomes. Also the paths through which intelligence influences reproductive outcomes are uncertain. The present study uses the NLSY79 to analyze…

  11. Reproductive Physiology of Marsupials

    ERIC Educational Resources Information Center

    Sharman, G. B.

    1970-01-01

    Describes some unique features of marsupial reproduction which include (1) chromosomal sex determination, (2) reproductive system, (3) birth, (4) location, and (5) embryonic diapause. These features suggest that viviparity evolved separately in eutherian and marsupial stocks after their derivation from a common oviparous ancestor. Bibliography.…

  12. Assessment of Male Reproductive Toxicity##

    EPA Science Inventory

    This review covers all aspects of male reproductive toxicology. It begins with an overview of male reproductive biology and then transitions to the considerations of conducting male reproductive toxicology studies. We discuss multigenerational study as proposed in EPAs harmoniz...

  13. Copy number variations related to reproduction traits in Holstein cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Daughter pregnancy rate (DPR) is one of important reproduction traits that affect overall profitability in dairy industry. However, historical selection for production and conformation rather than reproduction has resulted in a decline in cow fertility. Genomic structural variation including copy nu...

  14. [Reproductive aspects of celiac disease].

    PubMed

    Stazi, Anna Velia; Trinti, Biagino

    2005-01-01

    In the past, celiac disease (CD), or intolerance to gluten, was considered a rare disease of infancy characterized by chronic diarrhea with malabsorption and delayed growth. Besides the overt enteropathy, there are other clinic and subclinical forms which appear later in life. Target organs are not limited to the gut, but include liver, thyroid, skin and female and male reproductive systems. CD interference on reproduction is related to the multifactorial nature of the disease, whose pathological manifestations can be modulated, besides gluten, by different concurrent genetic and environmental factors. CD induces malabsorption with consequent deficiencies of micronutrients such as iron, folic acid and vitamin K, which are essential for organogenesis, and fat-soluble vitamins important for spermatogenesis. Regarding endocrine disorders, the deficiencies of specific trace elements on ovarian function could explain its involvement in the increased risk of female osteoporosis in CD patients. Affected males show a picture of tissue resistance to androgens; the increases of follicle-stimulating hormone and prolactin, not associated with infertility, may indicate an imbalance at hypothalamus-pituitary level, with general effects on health. Since reproductive alterations are reversible, adoption of a gluten-free diet supported by early diagnosis is important. Therefore, the detection of early biomarkers, such as deficiencies of vitamins and/or iron and andrological or endocrinological dysfunctions, should trigger timely strategies for prevention and treatment. PMID:16250182

  15. Effective use of assisted reproduction.

    PubMed

    Bhattacharya, Siladitya

    2003-05-01

    Subfertility affects one in seven couples in the western world. Although the availability of assisted reproduction has changed the outlook for many childless couples, the procedures themselves have far-reaching implications in terms of invasiveness, acceptability and cost. There is now greater awareness that effective care involves using treatments that combine efficacy, appropriateness and efficiency with safety. Randomized trials addressing assisted reproduction are few and generally tend to suffer from a number of methodological inadequacies. Although IVF continues to be the treatment of choice for couples with persistent infertility, there is currently insufficient evidence from trial data to indicate that IVF is more effective than the other treatment options available for unexplained infertility. Intracytoplasmic sperm injection is beneficial in severe male factor infertility but is not warranted in other situations. There is an urgent need to focus on developing strategies to improve success rates of assisted reproduction and minimize the side-effects such as ovarian hyperstimulation and multiple pregnancy. Multiple pregnancy is the most common major complication of IVF and has a profound effect on maternal and neonatal morbidity as well as health service costs. PMID:12869781

  16. Burst Firing Enhances Neural Output Correlation

    PubMed Central

    Chan, Ho Ka; Yang, Dong-Ping; Zhou, Changsong; Nowotny, Thomas

    2016-01-01

    Neurons communicate and transmit information predominantly through spikes. Given that experimentally observed neural spike trains in a variety of brain areas can be highly correlated, it is important to investigate how neurons process correlated inputs. Most previous work in this area studied the problem of correlation transfer analytically by making significant simplifications on neural dynamics. Temporal correlation between inputs that arises from synaptic filtering, for instance, is often ignored when assuming that an input spike can at most generate one output spike. Through numerical simulations of a pair of leaky integrate-and-fire (LIF) neurons receiving correlated inputs, we demonstrate that neurons in the presence of synaptic filtering by slow synapses exhibit strong output correlations. We then show that burst firing plays a central role in enhancing output correlations, which can explain the above-mentioned observation because synaptic filtering induces bursting. The observed changes of correlations are mostly on a long time scale. Our results suggest that other features affecting the prevalence of neural burst firing in biological neurons, e.g., adaptive spiking mechanisms, may play an important role in modulating the overall level of correlations in neural networks. PMID:27242499

  17. Interventions in the prolongation of reproductive life in women.

    PubMed

    Barlow, David H

    2011-03-01

    Women may seek to prolong their reproductive span for a variety of reasons. For many this implies reproduction at a late age, possibly driven by lifestyle decisions, but for others affected by a natural or a cancer treatment-induced premature ovarian failure it may simply mean seeking to achieve the normal reproductive span. The range of interventions now available to address the issue of prolonging reproductive life has never been greater, although several of the approaches discussed remain in the realm of future application through being dependent on ongoing scientific developments. PMID:21401623

  18. Fat supplementation and reproduction in beef females.

    PubMed

    Funston, R N

    2004-01-01

    Inadequate dietary energy intake and poor body condition can negatively affect reproductive function. Supplemental lipids have been used to increase energy density of the diet and may also have direct positive effects on reproduction in beef cattle. Several fatty acid sources have been studied as they relate to reproductive function. Common sources include sunflower, safflower, cottonseed, rice bran, soybeans, fishmeal, animal tallow, and calcium salts of fatty acids. Fats have been fed before and after calving, during the breeding season, and during heifer development. Response to fat has been investigated through measuring body weight and body condition score, age at puberty, postpartum interval, first-service conception rates, pregnancy rates, calving interval, calving difficulty, and calf birth and weaning weight. Animal response seems to depend on body condition score, age (parity), nutrients available in the diet, and type of fat supplemented. To elucidate potential mechanisms of action, scientists have investigated changes in follicular and uterine development, hormonal profiles, brain function, and embryonic development. Feeding supplemental fat has resulted in varied and inconsistent effects on reproductive function. Elucidating how supplemental fat can influence reproductive function has been a difficult process. The complexity of the reproductive system and makeup of fat supplements are often confounded by management conditions and forage quality both in research and commercial feeding situations. PMID:15471795

  19. Expanding the ecotoxicological toolbox: the inclusion of polychaete reproductive endpoints.

    PubMed

    Lewis, Ceri; Watson, Gordon J

    2012-04-01

    In the last 15 years the diversity of pollutants and routes of impact have increased. However, the polychaete families, species and endpoints investigated have remained fairly constant. Reproductive outputs are more ecologically relevant than adult physiological or biochemical changes. Nevertheless, there remains a paucity of data on the reproductive responses of the popular species to pollutants which limits our ability to understand the true ecological impacts of such contaminants on natural populations. We highlight the current knowledge gaps in our understanding of the impacts of pollutants on the 'model' species' reproductive biology and therefore the potential ecological impacts of such contaminants on their natural populations, and the potential benefits of a wider use of polychaete reproductive endpoints for ecotoxicological assessments. The following priority areas are suggested for inclusion in the polychaete ecotoxicology toolbox: 1. Include reproductive endpoints as assessments of ecotoxicology for the traditional 'model' species and those that have different reproductive traits to ensure broad ecological relevance. 2. Nereids and Arenicola marina should be used to investigate the interaction of pollutants with the endocrine/environmental control of reproduction. 3. Polychaetes are ideal for addressing the under representation of male eco-toxicity effects. 4. Emerging pollutants should be assessed with reproductive endpoints together with the traditional biomarkers. 5. Effects of pollutants on larval behaviour need to be explored considering the limited but equivocal results so far. PMID:21872922

  20. The maternal environment affects offspring viability via an indirect effect of yolk investment on offspring size.

    PubMed

    Warner, Daniel A; Lovern, Matthew B

    2014-01-01

    Environmental conditions that reproductive females experience can influence patterns of offspring provisioning and fitness. In particular, prey availability can influence maternal reproduction and, in turn, affect the viability of their offspring. Although such maternal effects are widespread, the mechanisms by which these effects operate are poorly understood. We manipulated the amount of prey available to female brown anole lizards (Anolis sagrei) to evaluate how this factor affects patterns of reproductive investment (total egg output, egg size, yolk steroids) and offspring viability (morphology, growth, survival). Experimental reduction of yolk in a subset of eggs enabled us to evaluate a potential causal mechanism (yolk investment) that mediates the effect of maternal prey availability on offspring viability. We show that limited prey availability significantly reduced egg size, which negatively influenced offspring size, growth, and survival. Experimental yolk removal from eggs directly reduced offspring size, which, in turn, negatively affected offspring growth and survival. These findings show that maternal environments (i.e., low prey) can affect offspring fitness via an indirect effect of yolk investment on offspring size and highlight the complex set of indirect effects by which maternal effects can operate. PMID:24642545

  1. Reproductive strategies in snakes.

    PubMed Central

    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 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. PMID:12803888

  2. Life history plasticity after attaining a dietary threshold for reproduction is associated with protein storage in flesh flies.

    PubMed

    Hahn, Daniel A; James, Laura N; Milne, Kathy R; Hatle, John D

    2008-12-01

    Body condition affects the timing and magnitude of life history transitions. Therefore, identifying proximate mechanisms involved in assessing condition is critical to understanding how these mechanisms affect the expression of life history plasticity. Nutrient storage is an important body condition parameter, likely playing roles in both attaining minimum body-condition thresholds for life history transitions and expression of life history traits.We manipulated protein availability for females of the flesh fly Sarcophaga crassipalpis to determine whether reproductive timing and output would remain plastic or become fixed. Liver was provided for 0, 2, 4, or 6 days of adult pre-reproductive development. Significantly, liver was removed after the feeding threshold had been attained and females had committed to producing a clutch.We also identified the major storage proteins and monitored their abundances, because protein stores may serve as an index of body condition and therefore may play an important role in life history transitions and plasticity.Flesh flies showed clear post-threshold plasticity in reproductive timing. Females fed protein for 2 days took ~30% longer to provision their clutch than those fed for 4 or 6 days. Observations of oogenesis showed the 2-day group expressed a different developmental program including slower egg provisioning.Protein availability also affected reproductive output. Females fed protein for 2 days produced ~20% fewer eggs than females fed 4 or 6 days. Six-day treated females provisioned larger eggs than 4-day treated females, followed by 2-day treated females with the smallest eggs.Two storage proteins were identified, LSP-1 and LSP-2. LSP-2 accumulation differed across feeding treatments. The 2- and 4-day treatment groups accumulated LSP-2 stores but depleted them during provisioning of the first clutch, whereas the 6-day group accumulated the greatest quantity of LSP-2 and had substantial LSP-2 stores remaining at the end of

  3. Impact of the environment on reproductive health.

    PubMed

    1991-01-01

    The WHO workshop on the impact of the environment on reproductive health is summarized. Topics include the nature of environmental factors affecting reproductive health, environmental factors blamed for declining sperm quantity and quality, the effects of natural and man-made disasters on reproductive health, chemical pollutants, how the environment damages reproductive health, and research needs for better research methodologies and surveillance data. Recommendations are made to: 1) promote international research collaboration with an emphasis on consistency of methodological approaches for assessing developmental and reproductive toxicity, on development of improved surveillance systems and data bases, an strengthening international disaster alert and evaluation systems; 2) promote research capabilities for multidisciplinary studies, for interactive studies of the environment and cellular processes, and for expansion of training and education; and 3) take action on priority problems of exposure to chemical, physical, and biological agents, of exposure to pesticides among specific populations, and of inadequate screening methods for identification of environmental chemicals. The costs of environmental injury to reproduction include subfertility, intrauterine growth retardation, spontaneous abortion, and various birth defects. Developed country's primary threats are from chemical pollution, radiation, and stress. There is a large gap in knowledge. Caution is urged in understanding the direct relationship between environmental causes and infertility. Sexual health is difficult to assess and research is suggested. Exposure to excessive vitamin A and toxic chemicals are cited as agents probably having serious effects on malformations. Sperm quality has declined over the decades; there is speculation about the potential causes. The effects of radiation such as at Chernobyl are described. Toxic chemical exposure such as in Bhopal, India killed thousands. Neurological

  4. Arsenic Toxicity in Male Reproduction and Development

    PubMed Central

    Kim, Yoon-Jae; Kim, Jong-Min

    2015-01-01

    Arsenic is a toxic metalloid that exists ubiquitously in the environment, and affects global health problems due to its carcinogenicity. In most populations, the main source of arsenic exposure is the drinking water. In drinking water, chronic exposure to arsenic is associated with increased risks of various cancers including those of skin, lung, bladder, and liver, as well as numerous other non-cancer diseases including gastrointestinal and cardiovascular diseases, diabetes, and neurologic and cognitive problems. Recent emerging evidences suggest that arsenic exposure affects the reproductive and developmental toxicity. Prenatal exposure to inorganic arsenic causes adverse pregnancy outcomes and children’s health problems. Some epidemiological studies have reported that arsenic exposure induces premature delivery, spontaneous abortion, and stillbirth. In animal studies, inorganic arsenic also causes fetal malformation, growth retardation, and fetal death. These toxic effects depend on dose, route and gestation periods of arsenic exposure. In males, inorganic arsenic causes reproductive dysfunctions including reductions of the testis weights, accessory sex organs weights, and epididymal sperm counts. In addition, inorganic arsenic exposure also induces alterations of spermatogenesis, reductions of testosterone and gonadotrophins, and disruptions of steroidogenesis. However, the reproductive and developmental problems following arsenic exposure are poorly understood, and the molecular mechanism of arsenic-induced reproductive toxicity remains unclear. Thus, we further investigated several possible mechanisms underlying arsenic-induced reproductive toxicity. PMID:26973968

  5. Arsenic Toxicity in Male Reproduction and Development.

    PubMed

    Kim, Yoon-Jae; Kim, Jong-Min

    2015-12-01

    Arsenic is a toxic metalloid that exists ubiquitously in the environment, and affects global health problems due to its carcinogenicity. In most populations, the main source of arsenic exposure is the drinking water. In drinking water, chronic exposure to arsenic is associated with increased risks of various cancers including those of skin, lung, bladder, and liver, as well as numerous other non-cancer diseases including gastrointestinal and cardiovascular diseases, diabetes, and neurologic and cognitive problems. Recent emerging evidences suggest that arsenic exposure affects the reproductive and developmental toxicity. Prenatal exposure to inorganic arsenic causes adverse pregnancy outcomes and children's health problems. Some epidemiological studies have reported that arsenic exposure induces premature delivery, spontaneous abortion, and stillbirth. In animal studies, inorganic arsenic also causes fetal malformation, growth retardation, and fetal death. These toxic effects depend on dose, route and gestation periods of arsenic exposure. In males, inorganic arsenic causes reproductive dysfunctions including reductions of the testis weights, accessory sex organs weights, and epididymal sperm counts. In addition, inorganic arsenic exposure also induces alterations of spermatogenesis, reductions of testosterone and gonadotrophins, and disruptions of steroidogenesis. However, the reproductive and developmental problems following arsenic exposure are poorly understood, and the molecular mechanism of arsenic-induced reproductive toxicity remains unclear. Thus, we further investigated several possible mechanisms underlying arsenic-induced reproductive toxicity. PMID:26973968

  6. The politics of reproduction.

    PubMed

    Ginsburg, F; Rapp, R

    1991-01-01

    The topic of human reproduction encompasses events throughout the human and especially female life-cycle as well as ideas and practices surrounding fertility, birth, and child care. Most of the scholarship on the subject, up through the 1960s, was based on cross-cultural surveys focused on the beliefs, norms, and values surrounding reproductive behaviors. Multiple methodologies and subspecialties, and fields like social history, human biology, and demography were utilized for the analysis. The concept of the politics of reproduction synthesizes local and global perspectives. The themes investigated include: the concept of reproduction, population control, and the internationalization of state and market interests (new reproductive technologies); social movements and contested domains; medicalization and its discontents; fertility and its control; adolescence and teen pregnancy; birth; birth attendants; the construction of infancy and the politics of child survival; rethinking the demographic transition; networks of nurturance; and meanings of menopause. The medicalization of reproduction is a central issue of studies of birth, midwifery, infertility, and reproductive technologies. Scholars have also analyzed different parts of the female life-cycle as medical problems. Other issues worth analysis include the internationalization of adoption and child care workers; the crisis of infertility of low-income and minority women who are not candidates for expensive reproductive technologies; the concerns of women at high risk for HIV whose cultural status depends on their fertility; questions of reproduction concerning, lesbians and gay men (artificial insemination and discrimination in child rearing); the study of menopause; and fatherhood. New discourse analysis is used to analyze state eugenic policies; conflicts over Western neocolonial influences in which women's status as childbearers represent nationalist interests; fundamentalist attacks on abortion rights; and

  7. Compact Circuit Preprocesses Accelerometer Output

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr.

    1993-01-01

    Compact electronic circuit transfers dc power to, and preprocesses ac output of, accelerometer and associated preamplifier. Incorporated into accelerometer case during initial fabrication or retrofit onto commercial accelerometer. Made of commercial integrated circuits and other conventional components; made smaller by use of micrologic and surface-mount technology.

  8. World Input-Output Network

    PubMed Central

    Cerina, Federica; Zhu, Zhen; Chessa, Alessandro; Riccaboni, Massimo

    2015-01-01

    Production systems, traditionally analyzed as almost independent national systems, are increasingly connected on a global scale. Only recently becoming available, the World Input-Output Database (WIOD) is one of the first efforts to construct the global multi-regional input-output (GMRIO) tables. By viewing the world input-output system as an interdependent network where the nodes are the individual industries in different economies and the edges are the monetary goods flows between industries, we analyze respectively the global, regional, and local network properties of the so-called world input-output network (WION) and document its evolution over time. At global level, we find that the industries are highly but asymmetrically connected, which implies that micro shocks can lead to macro fluctuations. At regional level, we find that the world production is still operated nationally or at most regionally as the communities detected are either individual economies or geographically well defined regions. Finally, at local level, for each industry we compare the network-based measures with the traditional methods of backward linkages. We find that the network-based measures such as PageRank centrality and community coreness measure can give valuable insights into identifying the key industries. PMID:26222389

  9. Coral Mortality and Bleaching Output

    EPA Science Inventory

    COMBO is a spreadsheet-based model for the use of managers, conservationists, and biologists for projecting the effects of climate change on coral reefs at local-to-regional scales. The COMBO (Coral Mortality and Bleaching Output) model calculates the impacts to coral reefs from...

  10. World Input-Output Network.

    PubMed

    Cerina, Federica; Zhu, Zhen; Chessa, Alessandro; Riccaboni, Massimo

    2015-01-01

    Production systems, traditionally analyzed as almost independent national systems, are increasingly connected on a global scale. Only recently becoming available, the World Input-Output Database (WIOD) is one of the first efforts to construct the global multi-regional input-output (GMRIO) tables. By viewing the world input-output system as an interdependent network where the nodes are the individual industries in different economies and the edges are the monetary goods flows between industries, we analyze respectively the global, regional, and local network properties of the so-called world input-output network (WION) and document its evolution over time. At global level, we find that the industries are highly but asymmetrically connected, which implies that micro shocks can lead to macro fluctuations. At regional level, we find that the world production is still operated nationally or at most regionally as the communities detected are either individual economies or geographically well defined regions. Finally, at local level, for each industry we compare the network-based measures with the traditional methods of backward linkages. We find that the network-based measures such as PageRank centrality and community coreness measure can give valuable insights into identifying the key industries. PMID:26222389

  11. Classroom Interaction and Language Output

    ERIC Educational Resources Information Center

    Wang, Qiaoying; Castro, Carolyn D.

    2010-01-01

    This study investigates the effects of classroom interactions between a) students and students and b) students and teachers on the learning of English passivization by L1 Chinese adult learners of English as a foreign language during the language input and output treatments. In phase 1, both groups were asked to read and underline the input…

  12. Input/output interface module

    NASA Technical Reports Server (NTRS)

    Ozyazici, E. M.

    1980-01-01

    Module detects level changes in any of its 16 inputs, transfers changes to its outputs, and generates interrupts when changes are detected. Up to four changes-in-state per line are stored for later retrieval by controlling computer. Using standard TTL logic, module fits 19-inch rack-mounted console.

  13. Reproductive Physiology in Young Men Is Cumulatively Affected by FSH-Action Modulating Genetic Variants: FSHR -29G/A and c.2039 A/G, FSHB -211G/T

    PubMed Central

    Grigorova, Marina; Punab, Margus; Punab, Anna Maria; Poolamets, Olev; Vihljajev, Vladimir; Žilaitienė, Birutė; Erenpreiss, Juris; Matulevičius, Valentinas; Laan, Maris

    2014-01-01

    Follicle-Stimulating Hormone Receptor (FSHR) -29G/A polymorphism (rs1394205) was reported to modulate gene expression and reproductive parameters in women, but data in men is limited. We aimed to bring evidence to the effect of FSHR -29G/A variants in men. In Baltic young male cohort (n = 982; Estonians, Latvians, Lithuanians; aged 20.2±2.0 years), the FSHR -29 A-allele was significantly associated with higher serum FSH (linear regression: effect 0.27 IU/L; P = 0.0019, resistant to Bonferroni correction for multiple testing) and showed a non-significant trend for association with higher LH (0.19 IU/L) and total testosterone (0.93 nmol/L), but reduced Inhibin B (−7.84 pg/mL) and total testes volume (effect −1.00 mL). Next, we extended the study and tested the effect of FSHR gene haplotypes determined by the allelic combination of FSHR -29G/A and a well-studied variant c.2039 A/G (Asn680Ser, exon 10). Among the FSHR -29A/2039G haplotype carriers (A-Ser; haplotype-based linear regression), this genetic effect was enhanced for FSH (effect 0.40 IU/L), Inhibin B (−16.57 pg/mL) and total testes volume (−2.34 mL). Finally, we estimated the total contribution of three known FSH-action modulating SNPs (FSHB -211G/T; FSHR -29G/A, c.2039 A/G) to phenotypic variance in reproductive parameters among young men. The major FSH-action modulating SNPs explained together 2.3%, 1.4%, 1.0 and 1.1% of the measured variance in serum FSH, Inhibin B, testosterone and total testes volume, respectively. In contrast to the young male cohort, neither FSHR -29G/A nor FSHR haplotypes appeared to systematically modulate the reproductive physiology of oligozoospermic idiopathic infertile patients (n = 641, Estonians; aged 31.5±6.0 years). In summary, this is the first study showing the significant effect of FSHR -29G/A on male serum FSH level. To account for the genetic effect of known common polymorphisms modulating FSH-action, we suggest haplotype-based analysis of FSHR SNPs

  14. Reproductive Management for Optimal Oocyte Development to Enhance Fertility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are multiple steps associated with the ovulatory follicle that affect oocyte growth, fertilization, embryo development and establishment of pregnancy. When estrous cycles are manipulated with assisted reproductive technologies and ovulation induced, some of these variables become more importa...

  15. Migratory carryover effects and endocrinological correlates of reproductive decisions and reproductive success in female albatrosses.

    PubMed

    Crossin, Glenn T; Phillips, Richard A; Trathan, Phil N; Fox, Derren S; Dawson, Alistair; Wynne-Edwards, Katherine E; Williams, Tony D

    2012-04-01

    Physiological mechanisms mediating carryover effects, wherein events or activities occurring in one season, habitat, or life-history stage affect important processes in subsequent life-history stages, are largely unknown. The mechanism most commonly invoked to explain carryover effects from migration centres on the acquisition and utilization of resources (e.g. body mass, or individual 'condition'). However, other mechanisms are plausible, e.g. trade-offs reflecting conflict or incompatibility between physiological regulatory systems required for different activities or life-history stages (migration vs. reproduction). Here we show that in female black-browed albatrosses (Thalassarche melanophris) the decision to reproduce or to defer reproduction, made prior to their arrival at breeding colonies after long-distance migration, is associated with condition-related (body mass, hematocrit, hemoglobin concentrations) and hormonal (progesterone, testosterone, estrogen-dependent yolk precursors) traits. In contrast, reproductive success showed little association with condition but showed significant associations with the steroidogenic processes underlying follicle development. Specifically, success was determined by reproductive readiness via differences in steroid hormones and hormone-dependent traits. Successful albatrosses were characterized by high progesterone and high estradiol-dependent yolk precursor levels, whereas failed albatrosses had high testosterone and low yolk precursor levels. Results are discussed with reference to migratory carryover effects and how these can differentially affect the physiologies influencing reproductive decisions and reproductive success. PMID:22285395

  16. Reproductive cycles and reproductive strategies among populations of the Rose-bellied Lizard Sceloporus variabilis (Squamata: Phrynosomatidae) from central Mexico.

    PubMed

    Cruz-Elizalde, Raciel; Ramírez-Bautista, Aurelio

    2016-03-01

    Species with wide distribution, generally show variations in life history characteristics, which can be attributed to environmental causes. In this study, we analyzed the reproductive cycle and reproductive characteristics from three populations (Atlapexco, San Pablo Tetlapayac, and Santa Catarina) of the lizard Sceloporus variabilis from central Mexico. The specific goal of this study was to evaluate life history characteristics such as reproductive period extent, SVL (snout-vent length) at sexual maturity, clutch size, egg mass and volume, and RCM (relative clutch mass). The San Pablo Tetlapayac population showed a larger clutch size, RCM, egg mass, and a smaller SVL, body mass and reproductive period (January-September), as well as egg volume than the Atlapexco and Santa Catarina populations. Reproductive cycle and reproductive characteristics were more similar between the Atlapexco and Santa Catarina populations. Differences found in the population of San Pablo Tetlapayac with respect to the Atlapexco and Santa Catarina populations could be attributed to environmental variations where lizard populations occur. Differences in the reproductive period and reproductive characteristics in each population could be the result of both historical (phylogenetic; e.g., reproductive mode) and nonhistorical (environmental; e.g., temperature, food availability) causes. This study showed that populations of the same species are under different selection pressures, and these affect the reproductive characteristics of populations. Our results also indicate that long-term and targeted studies on predation, use and selection of food, are needed to determine the causes of these variations in populations of S. variabilis. PMID:26929815

  17. Life span and reproductive cost explain interspecific variation in the optimal onset of reproduction.

    PubMed

    Mourocq, Emeline; Bize, Pierre; Bouwhuis, Sandra; Bradley, Russell; Charmantier, Anne; de la Cruz, Carlos; Drobniak, Szymon M; Espie, Richard H M; Herényi, Márton; Hötker, Hermann; Krüger, Oliver; Marzluff, John; Møller, Anders P; Nakagawa, Shinichi; Phillips, Richard A; Radford, Andrew N; Roulin, Alexandre; Török, János; Valencia, Juliana; van de Pol, Martijn; Warkentin, Ian G; Winney, Isabel S; Wood, Andrew G; Griesser, Michael

    2016-02-01

    Fitness can be profoundly influenced by the age at first reproduction (AFR), but to date the AFR-fitness relationship only has been investigated intraspecifically. Here, we investigated the relationship between AFR and average lifetime reproductive success (LRS) across 34 bird species. We assessed differences in the deviation of the Optimal AFR (i.e., the species-specific AFR associated with the highest LRS) from the age at sexual maturity, considering potential effects of life history as well as social and ecological factors. Most individuals adopted the species-specific Optimal AFR and both the mean and Optimal AFR of species correlated positively with life span. Interspecific deviations of the Optimal AFR were associated with indices reflecting a change in LRS or survival as a function of AFR: a delayed AFR was beneficial in species where early AFR was associated with a decrease in subsequent survival or reproductive output. Overall, our results suggest that a delayed onset of reproduction beyond maturity is an optimal strategy explained by a long life span and costs of early reproduction. By providing the first empirical confirmations of key predictions of life-history theory across species, this study contributes to a better understanding of life-history evolution. PMID:26763090

  18. My Reproductive Life Plan

    MedlinePlus

    ... Information For... Media Policy Makers My Reproductive Life Plan Language: English Español (Spanish) Recommend on Facebook Tweet ... use with their patients. How to Make a Plan First, think about your goals for school, for ...

  19. Teaching Plant Reproduction.

    ERIC Educational Resources Information Center

    Tolman, Marvin N., Ed.; Hardy, Garry R., Ed.

    2000-01-01

    Recommends using Amaryllis hippeastrum to teach young children about plant reproduction. Provides tips for growing these plants, discusses the fast growing rate of the plant, and explains the anatomy. (YDS)

  20. Assisted Reproductive Technology

    MedlinePlus

    Assisted reproductive technology (ART) is used to treat infertility. It includes fertility treatments that handle both a woman's egg and a man's sperm. ... is the most common and effective type of ART. ART procedures sometimes use donor eggs, donor sperm, ...

  1. A simulation exercise to teach principles of bovine reproductive management.

    PubMed

    Perry, G A; Smith, M F

    2004-05-01

    the exercise increased their understanding of how management decisions affect reproductive efficiency and profitability in a beef operation and also provided added confidence for students that applied for beef management positions. PMID:15144098

  2. Avian reproductive physiology

    USGS Publications Warehouse

    Gee, G.F.

    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

  3. Advances in human reproductive ecology.

    PubMed

    Ellison, P T

    1994-01-01

    Human reproductive ecology pertains to reproduction biology and changes due to environmental influences. The research literature relies on clinical, epidemiological, and demographic analysis. The emphasis is on normal, nonpathological states and a broad range of ecological conditions. This review focused on the importance of age and energetic stress from ecological conditions rather than dieting or self-directed exercise in changing female fecundity. The literature on male reproductive ecology is still small but growing. J.W. Wood provided a comprehensive overview of the field. Natural fertility, as defined by Henry, is the lack of parity-specific fertility limitation. There is evidence that fertility can vary widely in natural fertility populations. There are consistent age patterns among different natural fertility populations. Doring found that there was higher frequency of anovulatory and luteal insufficiency in cycles during perimenarche and perimenopausal periods. Infertility studies have shown declines in pregnancy rates in women over the age of 30 years. Ovum donation evaluations have found both uterine age and ovarian and oocyte age to be related to the probability of a successful pregnancy. Basal follicle stimulating hormone and the endometrial thickness are important predictors of ovarian capacity and related to age and declining fecundity. Much of the literature on fecundity is derived from women with impaired reproductive physiology. In Lipson and Ellison's study of healthy women, average follicular and average luteal estradiol values declined with increasing subject age. Low follicular levels were correlated with smaller follicular size, low oocyte fertilizability, reduced endometrial thickness, and low pregnancy rates. Comparisons across populations have shown that populations experience declines in luteal function with age, but levels of luteal functions varied widely. Chronic conditions which slow growth and delay reproductive maturation may impact

  4. Adaptive Neural Output Feedback Control of Output-Constrained Nonlinear Systems With Unknown Output Nonlinearity.

    PubMed

    Liu, Zhi; Lai, Guanyu; Zhang, Yun; Chen, Chun Lung Philip

    2015-08-01

    This paper addresses the problem of adaptive neural output-feedback control for a class of special nonlinear systems with the hysteretic output mechanism and the unmeasured states. A modified Bouc-Wen model is first employed to capture the output hysteresis phenomenon in the design procedure. For its fusion with the neural networks and the Nussbaum-type function, two key lemmas are established using some extended properties of this model. To avoid the bad system performance caused by the output nonlinearity, a barrier Lyapunov function technique is introduced to guarantee the prescribed constraint of the tracking error. In addition, a robust filtering method is designed to cancel the restriction that all the system states require to be measured. Based on the Lyapunov synthesis, a new neural adaptive controller is constructed to guarantee the prescribed convergence of the tracking error and the semiglobal uniform ultimate boundedness of all the signals in the closed-loop system. Simulations are implemented to evaluate the performance of the proposed neural control algorithm in this paper. PMID:25915964

  5. Asexual Reproduction in Holothurians

    PubMed Central

    Dolmatov, Igor Yu.

    2014-01-01

    Aspects of asexual reproduction in holothurians are discussed. Holothurians are significant as fishery and aquaculture items and have high commercial value. The last review on holothurian asexual reproduction was published 18 years ago and included only 8 species. An analysis of the available literature shows that asexual reproduction has now been confirmed in 16 holothurian species. Five additional species are also most likely capable of fission. The recent discovery of new fissiparous holothurian species indicates that this reproduction mode is more widespread in Holothuroidea than previously believed. New data about the history of the discovery of asexual reproduction in holothurians, features of fission, and regeneration of anterior and posterior fragments are described here. Asexual reproduction is obviously controlled by the integrated systems of the organism, primarily the nervous system. Special molecular mechanisms appear to determine the location where fission occurs along the anterior-posterior axis of the body. Alteration of the connective tissue strength of the body wall may play an important role during fission of holothurians. The basic mechanism of fission is the interaction of matrix metalloproteinases, their inhibitors, and enzymes forming cross-link complexes between fibrils of collagen. The population dynamics of fissiparous holothurians are discussed. PMID:25405228

  6. Continuation of sexual reproduction in Montipora capitata following bleaching

    NASA Astrophysics Data System (ADS)

    Cox, E. F.

    2007-09-01

    Bleaching is generally expected to produce detrimental impacts on coral reproduction. This study compared the fecundity of bleached and unbleached colonies of the Hawaiian coral Montipora capitata. It was hypothesized that bleaching would have no effect on reproduction because previous studies have shown that Montipora capitata can increase heterotrophic feeding following bleaching. Reproductive parameters, total reproductive output (bundles released ml-1 coral colony), number of eggs bundle-1, and egg size, measured in the summer of 2005 did not differ between colonies that bleached or did not bleach during 2004. These data were collected following a single bleaching event and cannot be used to predict the outcome should bleaching episodes become more frequent or severe.

  7. Reproduction-Immunity Trade-Offs in Insects.

    PubMed

    Schwenke, Robin A; Lazzaro, Brian P; Wolfner, Mariana F

    2016-01-01

    Immune defense and reproduction are physiologically and energetically demanding processes and have been observed to trade off in a diversity of female insects. Increased reproductive effort results in reduced immunity, and reciprocally, infection and activation of the immune system reduce reproductive output. This trade-off can manifest at the physiological level (within an individual) and at the evolutionary level (genetic distinction among individuals in a population). The resource allocation model posits that the trade-off arises because of competition for one or more limiting resources, and we hypothesize that pleiotropic signaling mechanisms regulate allocation of that resource between reproductive and immune processes. We examine the role of juvenile hormone, 20-hydroxyecdysone, and insulin/insulin-like growth factor-like signaling in regulating both oogenesis and immune system activity, and propose a signaling network that may mechanistically regulate the trade-off. Finally, we discuss implications of the trade-off in an ecological and evolutionary context. PMID:26667271

  8. Aging and reproductive potential in women.

    PubMed Central

    Fitzgerald, C.; Zimon, A. E.; Jones, E. E.

    1998-01-01

    Reproductive potential in women declines with age. Age-related changes in the ovary account for most of this loss of reproductive function. Oocytes, all of which are present at birth, decline in number and quality with age. The endocrine function of the ovary also declines with age, and the ovary becomes unable to sustain its normal function in the neuroendocrine axis. The neuroendocrine axis may be further affected by primary changes occurring in the hypothalamus and pituitary during aging, although this has not been established in humans. Aging also affects the function of the uterus as the endometrium loses its ability to support implantation and growth of an embryo. Diminished uterine function during aging may be due to changes in the uterine vasculature or to changes in the hormone-dependent development of the endometrium. Finally, aging increases a woman's risk of developing medical, gynecologic or obstetric conditions that may impair her fertility. Knowledge of these affects of aging on a woman's reproductive function is essential to advise and treat the growing number of women seeking pregnancy at advanced reproductive age. PMID:10527364

  9. UFO - The Universal FEYNRULES Output

    NASA Astrophysics Data System (ADS)

    Degrande, Céline; Duhr, Claude; Fuks, Benjamin; Grellscheid, David; Mattelaer, Olivier; Reiter, Thomas

    2012-06-01

    We present a new model format for automatized matrix-element generators, the so-called Universal FEYNRULES Output (UFO). The format is universal in the sense that it features compatibility with more than one single generator and is designed to be flexible, modular and agnostic of any assumption such as the number of particles or the color and Lorentz structures appearing in the interaction vertices. Unlike other model formats where text files need to be parsed, the information on the model is encoded into a PYTHON module that can easily be linked to other computer codes. We then describe an interface for the MATHEMATICA package FEYNRULES that allows for an automatic output of models in the UFO format.

  10. Microgyroscope with closed loop output

    NASA Technical Reports Server (NTRS)

    Challoner, A. Dorian (Inventor); Gutierrez, Roman C. (Inventor); Tang, Tony K. (Inventor); Cargille, Donald R. (Inventor)

    2002-01-01

    A micro-gyroscope (10) having closed loop operation by a control voltage (V.sub.TY), that is demodulated by an output signal of the sense electrodes (S1, S2), providing Coriolis torque rebalance to prevent displacement of the micro-gyroscope (10) on the output axis (y-axis). The present invention provides wide-band, closed-loop operation for a micro-gyroscope (10) and allows the drive frequency to be closely tuned to a high Q sense axis resonance. A differential sense signal (S1-S2) is compensated and fed back by differentially changing the voltage on the drive electrodes to rebalance Coriolis torque. The feedback signal is demodulated in phase with the drive axis signal (K.sub..omega..crclbar..sub.x) to produce a measure of the Coriolis force.

  11. Standardized multiple output power supply

    NASA Technical Reports Server (NTRS)

    Ragusa, E. V.

    1975-01-01

    A comprehensive program to develop a prototype model of a standardized multiple output power supply for use in space flight applications is described. The prototype unit was tested and evaluated to assure that the design would provide near optimum performance for the planned application. The prototype design used a dc-to-dc converter incorporating reqenerative current feedback with a time-ratio controlled duty cycle to achieve high efficiency over a wide variation of input voltage and output loads. The packaging concept uses a mainframe capable of accommodating up to four inverter/regulator modules with one common input filter and housekeeping module. Each inverter/regulator module provides a maximum of 100 watts or 10 amperes. Each module is adaptable to operate at any voltage between 4.0 volts and 108 volts. The prototype unit contains +5, + or - 15 and +28 volt modules.

  12. Research on output feedback control

    NASA Technical Reports Server (NTRS)

    Calise, A. J.; Kramer, F. S.

    1985-01-01

    In designing fixed order compensators, an output feedback formulation has been adopted by suitably augmenting the system description to include the compensator states. However, the minimization of the performance index over the range of possible compensator descriptions was impeded due to the nonuniqueness of the compensator transfer function. A controller canonical form of the compensator was chosen to reduce the number of free parameters to its minimal number in the optimization. In the MIMO case, the controller form requires a prespecified set of ascending controllability indices. This constraint on the compensator structure is rather innocuous in relation to the increase in convergence rate of the optimization. Moreover, the controller form is easily relatable to a unique controller transfer function description. This structure of the compensator does not require penalizing the compensator states for a nonzero or coupled solution, a problem that occurs when following a standard output feedback synthesis formulation.

  13. Telomeres, Age and Reproduction in a Long-Lived Reptile

    PubMed Central

    Plot, Virginie; Criscuolo, François; Zahn, Sandrine; Georges, Jean-Yves

    2012-01-01

    A major interest has recently emerged in understanding how telomere shortening, mechanism triggering cell senescence, is linked to organism ageing and life history traits in wild species. However, the links between telomere length and key history traits such as reproductive performances have received little attention and remain unclear to date. The leatherback turtle Dermochelys coriacea is a long-lived species showing rapid growth at early stages of life, one of the highest reproductive outputs observed in vertebrates and a dichotomised reproductive pattern related to migrations lasting 2 or 3 years, supposedly associated with different environmental conditions. Here we tested the prediction of blood telomere shortening with age in this species and investigated the relationship between blood telomere length and reproductive performances in leatherback turtles nesting in French Guiana. We found that blood telomere length did not differ between hatchlings and adults. The absence of blood telomere shortening with age may be related to an early high telomerase activity. This telomere-restoring enzyme was formerly suggested to be involved in preventing early telomere attrition in early fast-growing and long-lived species, including squamate reptiles. We found that within one nesting cycle, adult females having performed shorter migrations prior to the considered nesting season had shorter blood telomeres and lower reproductive output. We propose that shorter blood telomeres may result from higher oxidative stress in individuals breeding more frequently (i.e., higher costs of reproduction) and/or restoring more quickly their body reserves in cooler feeding areas during preceding migration (i.e., higher foraging costs). This first study on telomeres in the giant leatherback turtle suggests that blood telomere length predicts not only survival chances, but also reproductive performances. Telomeres may therefore be a promising new tool to evaluate individual reproductive

  14. Estradiol Membrane-Initiated Signaling and Female Reproduction

    PubMed Central

    Micevych, Paul E; Wong, Angela May; Mittelman-Smith, Melinda Anne

    2016-01-01

    The discoveries of rapid, membrane-initiated steroid actions and central nervous system steroidogenesis have changed our understanding of the neuroendocrinology of reproduction. Classical nuclear actions of estradiol and progesterone steroids affecting transcription are essential. However, with the discoveries of membrane-associated steroid receptors, it is becoming clear that estradiol and progesterone have neurotransmitter-like actions activating intracellular events. Ultimately, membrane-initiated actions can influence transcription. Estradiol membrane-initiated signaling (EMS) modulates female sexual receptivity and estrogen feedback regulating the luteinizing hormone (LH) surge. In the arcuate nucleus, EMS activates a lordosis-regulating circuit that extends to the medial preoptic nucleus and subsequently to the ventromedial nucleus (VMH)—the output from the limbic and hypothalamic regions. Here, we discuss how EMS leads to an active inhibition of lordosis behavior. To stimulate ovulation, EMS facilitates astrocyte synthesis of progesterone (neuroP) in the hypothalamus. Regulation of GnRH release driving the LH surge is dependent on estradiol-sensitive kisspeptin (Kiss1) expression in the rostral periventricular nucleus of the third ventricle (RP3V). NeuroP activation of the LH surge depends on Kiss1, but the specifics of signaling have not been well elucidated. RP3V Kiss1 neurons appear to integrate estradiol and progesterone information which feeds back onto GnRH neurons to stimulate the LH surge. In a second population of Kiss1 neurons, estradiol suppresses the surge but maintains tonic LH release, another critical component of the estrous cycle. Together, evidence suggests that regulation of reproduction involves membrane action of steroids, some of which are synthesized in the brain. PMID:26140715

  15. Towards gloss control in fine art reproduction

    NASA Astrophysics Data System (ADS)

    Baar, Teun; Brettel, Hans; Ortiz Segovia, Maria V.

    2015-03-01

    The studies regarding fine art reproduction mainly focus on the accuracy of colour and the recreation of surface texture properties. Since reflection properties other than colour are neglected, important details of the artwork are lost. For instance, gloss properties, often characteristic to painters and particular movements in the history of art, are not well reproduced. The inadequate reproduction of the different gloss levels of a piece of fine art leads to a specular reflection mismatch in printed copies with respect to the original works that affects the perceptual quality of the printout. We used different print parameters of a 3D high resolution printing setup to control the gloss level on a printout locally. Our method can be used to control gloss automatically and in crucial applications such as fine art reproduction.

  16. Issues in methods and measurement of thermodilution cardiac output.

    PubMed

    Sommers, M S; Woods, S L; Courtade, M A

    1993-01-01

    Criterion-related validity of the thermodilution cardiac output technique for cardiac output measurement has to have a high correlation (r = .91 to .98) with the direct Fick method, the gold standard of cardiac output measurement. Issues that can affect validity of the measurements include the position of the pulmonary artery catheter, the rate of injection of the indicator solution, the volume and temperature of the injectate, the timing of the injection of indicator solution during the respiratory cycle, the position of the subject, and the presence of concomitant infusions. Variation in measurement can be limited by considering the delivery system for the indicator solution, by recording time-temperature cardiac output curves, and by considering normal biologic variations. PMID:8337161

  17. High-Output Heart Failure Caused by Thyrotoxicosis and Beriberi.

    PubMed

    McCulloch, Brenda

    2015-12-01

    High-output heart failure is not seen as commonly as low-output heart failure and some of the typical guideline recommendations may not benefit patients with high-output failure. High-output failure is caused by several diseases, including thyrotoxicosis and beriberi, highlighted in this article. Thyrotoxicosis, caused by excessive thyroid hormone production, has profound hemodynamic effects. Wet beriberi, affecting predominately the cardiovascular system, is caused by severe thiamine deficiency, most commonly seen in patients with chronic alcoholism or poor nutrition from other causes. Prompt recognition of these infrequently seen syndromes is essential. This article outlines the medical treatment and nursing care needed to return these patients to a normal state. PMID:26567494

  18. Influences of clonality on plant sexual reproduction

    PubMed Central

    Barrett, Spencer C. H.

    2015-01-01

    Flowering plants possess an unrivaled diversity of mechanisms for achieving sexual and asexual reproduction, often simultaneously. The commonest type of asexual reproduction is clonal growth (vegetative propagation) in which parental genotypes (genets) produce vegetative modules (ramets) that are capable of independent growth, reproduction, and often dispersal. Clonal growth leads to an expansion in the size of genets and increased fitness because large floral displays increase fertility and opportunities for outcrossing. Moreover, the clonal dispersal of vegetative propagules can assist “mate finding,” particularly in aquatic plants. However, there are ecological circumstances in which functional antagonism between sexual and asexual reproductive modes can negatively affect the fitness of clonal plants. Populations of heterostylous and dioecious species have a small number of mating groups (two or three), which should occur at equal frequency in equilibrium populations. Extensive clonal growth and vegetative dispersal can disrupt the functioning of these sexual polymorphisms, resulting in biased morph ratios and populations with a single mating group, with consequences for fertility and mating. In populations in which clonal propagation predominates, mutations reducing fertility may lead to sexual dysfunction and even the loss of sex. Recent evidence suggests that somatic mutations can play a significant role in influencing fitness in clonal plants and may also help explain the occurrence of genetic diversity in sterile clonal populations. Highly polymorphic genetic markers offer outstanding opportunities for gaining novel insights into functional interactions between sexual and clonal reproduction in flowering plants. PMID:26195747

  19. The Effect of Public and Private Competition on High School Outputs in New York State

    ERIC Educational Resources Information Center

    Greene, Kenneth, V.; Byung-Goo, Kang

    2004-01-01

    An extensive data set on upstate New York school district is used to test whether competition from private schools and competition within the public school sector positively affect public school output and again whether different types of expenditures affect output differently. It finds generally significant positive effects of private competition…

  20. Polybrominated diphenyl ethers and multiple stressors influence the reproduction of free-ranging tree swallows (Tachycineta bicolor) nesting at wastewater treatment plants.

    PubMed

    Gilchrist, Tiffany T; Letcher, Robert J; Thomas, Philippe; Fernie, Kim J

    2014-02-15

    Reproductive success of birds is influenced by maternal factors, ambient temperatures, predation, food supply, and/or exposure to environmental contaminants e.g., flame retardants (FRs). Reproduction of tree swallows (Tachycineta bicolor) was compared among waste water treatment plants (WWTPs) and a reference reservoir in Ontario, Canada (2007-2010), to determine the importance of exposure to polybrominated diphenyl ether (PBDEs) FRs within a complex contaminant cocktail, relative to natural and biological factors known to influence avian reproduction. The birds primarily consumed insects emerging from the reference reservoir and WWTP outflows, where effluent mixed with receiving waters. FR egg concentrations were dominated by 5 PBDE congeners (∑5PBDEs): 2,2'.4,4',5-pentabromodiphenyl ether (BDE-99), 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), 2,2'4,4',6-pentabromodiphenyl ether (BDE-100), 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153), and 2,2',4,4',5,6'-hexabromodiphenyl ether (BDE-154), with much lower concentrations of decabromodiphenylether (BDE-209), hexabromocyclododecane (HBCDD), and novel FRs. Although higher than ∑5PBDEs, polychlorinated biphenyls (PCBs) egg concentrations were unlikely to affect the swallows' reproduction. Clutch size and timing, fledging, breeding success, and predation, varied significantly among sites, generally being poorer at WWTP1 and better at WWTP2. The early reproductive stages were sensitive to some FRs at measured concentrations. The ∑5PBDEs, maternal age, and minimum ambient temperatures predicted onset of egg laying in the most parsimonious statistical model, and there were positive relationships between egg size and HBCDD or BDE-209 concentrations. However, there were no significant correlations with any reproductive measures, individual BDE congeners or low concentrations of novel FRs, in this first such report for novel FRs and wild birds. Tree swallows are passerines, and passerines may differ from birds of prey

  1. Seasonal variation in reproductive traits of the oriental shrimp Palaemon macrodactylus (Crustacea: Caridea: Palaemonidae) in a non-native population

    NASA Astrophysics Data System (ADS)

    Vázquez, M. Guadalupe; Bas, Claudia C.; Spivak, Eduardo D.

    2013-12-01

    The magnitude of variations in reproductive traits of Palaemon macrodactylus females throughout a breeding season was studied in a non-native population at Mar del Plata harbor, Argentina. Fecundity, egg size, reproductive output, weight and elemental composition of eggs, and larvae were analyzed in females collected at the beginning, in the mid point, and near the end of a reproductive season and designated as early, middle season, and late females. The highest reproductive output was observed in early females, while the highest fecundity and egg volume occurred in middle season females. Eggs and larvae showed larger body mass in early than in late females. Embryos from early females contained and consumed more carbon during development than embryos from late females, and they also used part of the available nitrogen. Differences in reproduction were observed among the three groups of females. On the one hand, late females matured early but had a poor first reproduction, with few embryos and high egg loss; however, they had longer reproductive life and an enhanced reproductive output in the following season when they became early females. On the other hand, females collected at the midpoint in the reproductive season matured later and had the highest fecundity and egg volume. In addition, larvae with different characteristics resulted from each type of female and were presumably well adapted to the conditions prevailing at the moment they hatched. The extended reproductive period and the diversity of embryos and larvae produced may favor the invading ability of the species.

  2. Variation in probability of first reproduction of Weddell seals.

    PubMed

    Hadley, Gillian L; Rotella, Jay J; Garrott, Robert A; Nichols, James D

    2006-09-01

    1. For many species, when to begin reproduction is an important life-history decision that varies by individual and can have substantial implications for lifetime reproductive success and fitness. 2. We estimated age-specific probabilities of first-time breeding and modelled variation in these rates to determine age at first reproduction and understand why it varies in a population of Weddell seals in Erebus Bay, Antarctica. We used multistate mark-recapture modelling methods and encounter histories of 4965 known-age female seals to test predictions about age-related variation in probability of first reproduction and the effects of annual variation, cohort and population density. 3. Mean age at first reproduction in this southerly located study population (7.62 years of age, SD=1.71) was greater than age at first reproduction for a Weddell seal population at a more northerly and typical latitude for breeding Weddell seals (mean=4-5 years of age). This difference suggests that age at first reproduction may be influenced by whether a population inhabits the core or periphery of its range. 4. Age at first reproduction varied from 4 to 14 years, but there was no age by which all seals recruited to the breeding population, suggesting that individual heterogeneity exists among females in this population. 5. In the best model, the probability of breeding for the first time varied by age and year, and the amount of annual variation varied with age (average variance ratio for age-specific rates=4.3%). 6. Our results affirmed the predictions of life-history theory that age at first reproduction in long-lived mammals will be sensitive to environmental variation. In terms of life-history evolution, this variability suggests that Weddell seals display flexibility in age at first reproduction in order to maximize reproductive output under varying environmental conditions. Future analyses will attempt to test predictions regarding relationships between environmental covariates

  3. Microwave Transmitter With Multimode Output Section

    NASA Technical Reports Server (NTRS)

    Hoppe, Daniel J.; Bhanji, Alaudin M.; Cormier, Reginald A.

    1988-01-01

    Output-waveguide structure transports 400 kW of continuous-wave signal power at 34.5 GHz. Transmitter generates 400 kW of continuous-wave (CW) signal power. Main feature of conceptual design of this microwave transmitter is output section. Output waveguide structure includes mode converter, directional coupler, polarization monitor, and corrugated overmoded output section. Output directional pattern suitable for antenna illumination without flared feedhorn.

  4. A dynamic-bioenergetics model to assess depth selection and reproductive growth by lake trout (Salvelinus namaycush).

    PubMed

    Plumb, John M; Blanchfield, Paul J; Abrahams, Mark V

    2014-06-01

    We coupled dynamic optimization and bioenergetics models to assess the assumption that lake trout (Salvelinus namaycush) depth distribution is structured by temperature, food availability, and predation risk to maximize reproductive mass by autumn spawning. Because the model uses empirical daily thermal-depth profiles recorded in a small boreal shield lake (lake 373 at the Experimental Lakes Area, northwestern Ontario) during 2 years of contrasting thermal stratification patterns, we also assessed how climate-mediated changes in lakes may affect the vertical distribution, growth, and fitness of lake trout, a cold-water top predator. The depths of acoustic-tagged lake trout were recorded concurrently with thermal-depth profiles and were compared to model output, enabling an assessment of model performance in relation to the observed fish behavior and contrasting thermal conditions. The depths and temperatures occupied by simulated fish most closely resembled those of the tagged fish when risk of predation was included in the model, indicating the model may incorporate the most important underlying mechanisms that determine lake trout depth. Annual differences suggest less use of shallow (warm), productive habitats, resulting in markedly less reproductive mass, during the year with the warm stratification pattern. Mass for reproduction may be lower in warmer conditions because of reduced reproductive investment, yet survival may be inadvertently higher because risky surface waters may be avoided more often in warmer, shallower, and metabolically costly conditions. At a minimum our study suggests that lake trout reproductive mass and fitness may be expected to change under the anticipated longer and warmer stratification patterns. PMID:24682254

  5. Leptin and reproductive function.

    PubMed

    Hausman, Gary J; Barb, C Richard; Lents, Clay A

    2012-10-01

    Adipose tissue plays a dynamic role in whole-body energy homeostasis by acting as an endocrine organ. Collective evidence indicates a strong link between neural influences and adipocyte expression and secretion of leptin. Developmental changes in these relationships are considered important for pubertal transition in reproductive function. Leptin augments secretion of gonadotropin hormones, which are essential for initiation and maintenance of normal reproductive function, by acting centrally at the hypothalamus to regulate gonadotropin-releasing hormone (GnRH) neuronal activity and secretion. The effects of leptin on GnRH are mediated through interneuronal pathways involving neuropeptide-Y, proopiomelanocortin and kisspeptin. Increased infertility associated with diet induced obesity or central leptin resistance are likely mediated through the kisspeptin-GnRH pathway. Furthermore, Leptin regulates reproductive function by altering the sensitivity of the pituitary gland to GnRH and acting at the ovary to regulate follicular and luteal steroidogenesis. Thus leptin serves as a putative signal that links metabolic status with the reproductive axis. The intent of this review is to examine the biological role of leptin with energy metabolism, and reproduction. PMID:22980196

  6. Adipokines in human reproduction.

    PubMed

    Dupont, Joëlle; Pollet-Villard, Xavier; Reverchon, Maxime; Mellouk, Namya; Levy, Rachel

    2015-10-01

    Adipose tissue communicates with other central and peripheral organs by the synthesis and release of substances called adipokines. The most studied adipokine is leptin but others have been recently identified including resistin, adiponectin, chemerin, omentin and visfatin. These adipokines have a critical role in the development of obesity-related complications and inflammatory conditions. However, they are also involved in other functions in the organism including reproductive functions. Indeed, many groups have demonstrated that adipokine receptors, such as adiponectin and chemerin, but also adipokines themselves (adiponectin, chemerin, resistin, visfatin and omentin) are expressed in human peripheral reproductive tissues and that these adipokines are likely to exert direct effects on these tissues. After a brief description of these new adipokines, an overview of their actions in different human reproductive organs (hypothalamus, pituitary, ovary, testis, uterus and placenta) will be presented. Finally, comments will be made on the eventual alterations of these adipokines in reproductive disorders, with special attention to polycystic ovary syndrome, a disease characterized by dysfunction of gonadal axis and systemic nerve endocrine metabolic network with a prevalence of up to 10% in women of reproductive age. PMID:26574894

  7. The involvement of gonadotropin inhibitory hormone and kisspeptin in the metabolic regulation of reproduction.

    PubMed

    Wahab, F; Shahab, M; Behr, R

    2015-05-01

    Recently, kisspeptin (KP) and gonadotropin inhibitory hormone (GnIH), two counteracting neuropeptides, have been acknowledged as significant regulators of reproductive function. KP stimulates reproduction while GnIH inhibits it. These two neuropeptides seem to be pivotal for the modulation of reproductive activity in response to internal and external cues. It is well-documented that the current metabolic status of the body is closely linked to its reproductive output. However, how reproductive function is regulated by the body's energy status is less clear. Recent studies have suggested an active participation of hypothalamic KP and GnIH in the modulation of reproductive function according to available metabolic cues. Expression of KISS1, the KP encoding gene, is decreased while expression of RFRP (NPVF), the gene encoding GnIH, is increased in metabolic deficiency conditions. The lower levels of KP, as suggested by a decrease in KISS1 gene mRNA expression, during metabolic deficiency can be corrected by administration of exogenous KP, which leads to an increase in reproductive hormone levels. Likewise, administration of RF9, a GnIH receptor antagonist, can reverse the inhibitory effect of fasting on testosterone in monkeys. Together, it is likely that the integrated function of both these hypothalamic neuropeptides works as a reproductive output regulator in response to a change in metabolic status. In this review, we have summarized literature from nonprimate and primate studies that demonstrate the involvement of KP and GnIH in the metabolic regulation of reproduction. PMID:25957191

  8. Biofluidmechanics of Reproduction

    NASA Astrophysics Data System (ADS)

    Fauci, Lisa J.; Dillon, Robert

    2006-01-01

    Mammalian fertilization requires the coordinated activity of motile spermatozoa, muscular contractions of the uterus and oviduct, as well as ciliary beating. These elastic structures generate forces that drive fluid motion, but their configurations are, in turn, determined by the fluid dynamics. We review the basic fluid mechanical aspects of reproduction, including flagellar/ciliary beating and peristalsis. We report on recent biological studies that have shed light on the relative importance of the mechanical ingredients of reproduction. In particular, we examine sperm motility in the reproductive tract, ovum pickup and transport in the oviduct, as well as sperm-egg interactions. We review recent advances in understanding the internal mechanics of cilia and flagella, flagellar surface interaction, sperm motility in complex fluids, and the role of fluid dynamics in embryo transfer. We outline promising computational fluid dynamics frameworks that may be used to investigate these complex, fluid-structure interactions.

  9. Dinosaur Reproduction and Parenting

    NASA Astrophysics Data System (ADS)

    Horner, John R.

    Non-avian dinosaur reproductive and parenting behaviors were mostly similar to those of extant archosaurs. Non-avian dinosaurs were probably sexually dimorphic and some may have engaged in hierarchical rituals. Non-avian coelurosaurs (e.g. Troodontidae, Oviraptorosauria) had two active oviducts, each of which produced single eggs on a daily or greater time scale. The eggs of non-coelurosaurian dinosaurs (e.g. Ornithischia, Sauropoda) were incubated in soils, whereas the eggs of non-avian coelurosaurs (e.g. Troodon, Oviraptor) were incubated with a combination of soil and direct parental contact. Parental attention to the young was variable, ranging from protection from predators to possible parental feeding of nest-bound hatchlings. Semi-altricial hadrosaur hatchlings exited their respective nests near the time of their first linear doubling. Some reproductive behaviors, once thought exclusive to Aves, arose first in non-avian dinosaurs. The success of the Dinosauria may be related to reproductive strategies.

  10. Human reproduction: Jewish perspectives.

    PubMed

    Schenker, Joseph G

    2013-11-01

    Developments in science and technology and corresponding clinical applications raise new religious questions, often without clear answers. The role of theology in bioethics is integral to clarify perceived attitudes toward these developments for different religious communities. The Jewish attitude towards procreation is derived from the first commandment of God to Adam to 'Be fruitful and multiply'. Judaism allows the practice of all techniques of assisted reproduction when the oocyte and spermatozoon originate from the wife and husband respectively. This paper presents the attitude of Jewish Law -- Halacha to therapeutic procedures, such as IVF-embryo transfer, spermatozoa, oocytes, embryo donation, cryopreservation of genetic material, surrogacy, posthumous reproduction, gender preselection, reproductive and therapeutic cloning. PMID:24000935

  11. Introduction: Communicating Reproduction.

    PubMed

    Hopwood, Nick; Jones, Peter Murray; Kassell, Lauren; Secord, Jim

    2015-01-01

    Communication should be central to histories of reproduction, because it has structured how people do and do not reproduce. Yet communication has been so pervasive, and so various, that it is often taken for granted and the historical specificities overlooked. Making communication a frame for histories of reproduction can draw a fragmented field together, including by putting the promotion of esoteric ideas on a par with other practical activities. Paying communication close attention can revitalize the history of reproduction over the long term by highlighting continuities as well as the complex connections between new technologies and new approaches. Themes such as the power of storytelling, the claiming and challenging of expertise, and relations between knowledge and ignorance, secrecy and propriety also invite further study. PMID:26521666

  12. Reproductive rights under attack.

    PubMed

    Mcdonald, K

    1995-01-01

    Women's groups, politicians, nongovernmental organizations, funding groups, and donor countries must all be lobbied with the message that sexual and reproductive health issues are inextricably linked to women in development, education, and future economic strength of nations worldwide. In the Beijing Nongovernmental Organization (NGO) Forum the draft Plan of Action had 35% of its language bracketed and subject to negotiation in Beijing. The previous International Conference on Population and Development (ICPD) in Cairo had only 15% of its language bracketed. Much of the language bracketed for Beijing had already been fully agreed upon before the Cairo conference. The bracketed language was in the health and human rights sections, and most of the language pertained to sexual and reproductive health. The increase in controversy is due to an opposition better organized in Beijing than it had been in Cairo, due to the opposition's failure to recognize the implications of the Cairo declarations on women, men, and children, and due to the opposition's general intolerance of sexual and reproductive issues. The major factor, however, was the linking of women's rights with sexual and reproductive health issues. Family planners joined with women's rights groups, which had always promoted women's control over their bodies as the cornerstone of equality. This connection was interpreted as a threat to the social order by conservative societies. NGO participants included 1400 people representing 170 countries. The NGO anti-abortion contingent was well-funded, well-organized, and large. Lobbying was conducted in an effort to convince people to oppose any language pertaining to gender, sexual and reproductive health, and adolescent rights. Anti-abortion lobbyists also rifled through documents of pro-choice participants. In Canada and the United States anti-abortion groups are lobbying hard to overturn the Cairo Plan of Action and to expand their efforts internationally among

  13. Recasts, Language Anxiety, Modified Output, and L2 Learning

    ERIC Educational Resources Information Center

    Sheen, Younghee

    2008-01-01

    The study reported in this article investigated (a) whether classroom language anxiety affects learners' ability to improve accuracy in their use of English articles when provided with corrective feedback in the form of recasts and (b) whether language anxiety influences the extent to which learners modify output following recasts. Four groups…

  14. Random output and hospital performance.

    PubMed

    Barros, Pedro Pita

    2003-11-01

    Many countries are under pressure to reform health care financing and delivery. Hospital care is one part of the health system that is under scrutiny. Private management initiatives are a possible way to increase efficiency in health care delivery. This motivates the interest in developing methodologies to assess hospital performance, recognizing hospitals as a different sort of firm. We present a simple way to describe hospital production: hospital output as a change in the distribution of survival probabilities. This output definition allows us to separate hospital production from patients' characteristics. The notion of "better performance" has a precise meaning: (first-order) stochastic dominance of a distribution of survival probabilities over another distribution. As an illustration, we compare, for an important DRG, private and public management and find that private management performs better, mainly in the range of high-survival probabilities. The measured performance difference cannot be attributed to input prices or to economies of scale and/or scope. It reflects pure technological and organisational differences. PMID:14686628

  15. Reproductive Disorders in Horses.

    PubMed

    Snider, Timothy A

    2015-08-01

    Reproductive disease is relatively common in the horse, resulting in a variable, yet significant, economic impact on individual horsemen as well as the entire industry. Diverse expertise from the veterinary community ensures and improves individual and population health of the horse. From a pathology and diagnostics perspective, this review provides a comprehensive overview of pathology of the male and female equine reproductive tract. Recognition by clinical and gross features is emphasized, although some essential histologic parameters are included, as appropriate. Where relevant, discussion of ancillary diagnostic tests and approaches are included for some diseases and lesions. PMID:26210954

  16. Feminism and reproductive technologies.

    PubMed

    Callahan, Joan C

    1994-01-01

    ... Rowland is a social scientist and a radical feminist, and she has undertaken the task of making readers think twice about reproductive technologies. If a reader isn't thinking twice, it will not do to blame it on Rowland and the shortcomings of her book. She has a good deal to say that is extremely important and that needs to be considered by anyone who is interested in the moral issues, in general, and the issues for women and children, in particular, that are raised by the new and emerging reproductive technologies. Her book should be widely read. And it should generate the worries it is written to generate. PMID:11644539

  17. Role of free radicals in female reproductive diseases and assisted reproduction.

    PubMed

    Agarwal, Ashok; Allamaneni, Shyam S R

    2004-09-01

    Infertility is a common problem experienced by many couples. Numerous treatments are available for female infertility. However, in some cases, the treatment is empirical in nature because the aetiology of infertility is not fully understood. Recently, reactive oxygen species (ROS) have been shown to have an important role in the normal functioning of reproductive system and in the pathogenesis of infertility in females. Reactive oxygen species may also play a role in other reproductive organ diseases of women such as endometriosis. Oxidative stress develops when there is an imbalance between the generation of ROS and the scavenging capacity of antioxidants in the reproductive tract. It affects both natural and assisted fertility. Because assisted reproductive techniques are used extensively in the treatment of infertility, it is critical to understand the in-vitro conditions that affect fertilization and embryo development. Treatments that reduce oxidative stress may help infertile women with diseases that are caused by this imbalance. Such strategies include identifying the source of excessive generation of ROS, treating the primary cause, and in-vitro and in-vivo supplementation of antioxidants. Research is in progress to identify the mechanisms that are involved in the aetiology of female reproductive diseases caused by ROS, and to create effective strategies that can counteract oxidative stress. PMID:15353087

  18. Drosophila Sperm Motility in the Reproductive Tract1

    PubMed Central

    Yang, Yong; Lu, Xiangyi

    2011-01-01

    Motile cilia and flagella exhibit many waveforms as outputs of dynein activation sequences on the highly conserved axoneme. Motility change of sperm in the reproductive tract is difficult to study and remains an important area of investigation. Sperm typically execute a sinusoidal waveform. Increased viscosity in the medium induces somewhat unusual arc-line and helical waveforms in some sperm. However, whether the latter two waveforms occur in vivo is not known. Using green fluorescence protein imaging, we show that Drosophila sperm in the uterus move in circular foci via arc-line waves, predominantly in a tail-leading orientation. From the uterus, a small fraction of the sperm enters the seminal receptacle (SR) in parallel formations. After sperm storage and coincident with fertilization of the egg, the sperm exit the SR via head-leading helical waves. Consistent with the observed bidirectional movements, the sperm show the ability to propagate both base-to-tip and tip-to-base flagellar waves. Numerous studies have shown that sperm motility is regulated by intraflagellar calcium concentrations; in particular, the Pkd2 calcium channel has been shown to affect sperm storage. Our analyses here suggest that Pkd2 is required for the sperm to adopt the correct waveform and movement orientation during SR entry. A working model for the sperm's SR entry movement is proposed. PMID:21293028

  19. Reproductive success of belted kingfishers on the upper Hudson River.

    PubMed

    Bridge, Eli S; Kelly, Jeffrey F

    2013-08-01

    Belted kingfishers (Megaceryle alcyon) are predators in many North American aquatic ecosystems; as such, they are prone to bioaccumulation of certain environmental contaminants. In 2002 and 2004, kingfisher eggs collected near the upper Hudson River in New York had elevated concentrations of polychlorinated biphenyls (PCBs), and the kingfisher population in this area was reported to be at risk because of PCB exposure. From 2007 to 2009, the authors monitored 69 kingfisher nests on the Hudson River to track both nest success and survival of individual nestlings. The study site consisted of 2 adjacent sections of the Hudson River, 1 upstream and 1 downstream of a historic PCB source. The authors compared models of nest success that differentially incorporated the following 4 variables that they deemed most likely to affect reproductive output: 1) river section (upstream vs downstream of PCB source), 2) year, 3) hatch date, and 4) abandonment by 1 parent. After ranking models according to Akaike's information criterion for small sample sizes, it was clear that parental abandonment was the most important of the factors examined. River section was not an important parameter, and overall nesting success was slightly higher in the PCB-contaminated section than in the upstream area. These findings support the conclusion that kingfisher productivity is not adversely impacted by PCB contamination in the upper Hudson River. PMID:23633435

  20. Overload protection circuit for output driver

    DOEpatents

    Stewart, Roger G.

    1982-05-11

    A protection circuit for preventing excessive power dissipation in an output transistor whose conduction path is connected between a power terminal and an output terminal. The protection circuit includes means for sensing the application of a turn on signal to the output transistor and the voltage at the output terminal. When the turn on signal is maintained for a period of time greater than a given period without the voltage at the output terminal reaching a predetermined value, the protection circuit decreases the turn on signal to, and the current conduction through, the output transistor.

  1. Reproductive Market Values Explain Post-reproductive Lifespans in Men.

    PubMed

    Vinicius, Lucio; Migliano, Andrea Bamberg

    2016-03-01

    Post-reproductive lifespans (PRLSs) of men vary across traditional societies. We argue that if sexual selection operates on male age-dependent resource availability (or 'reproductive market values') the result is variation in male late-life reproduction across subsistence systems. This perspective highlights the uniqueness of PRLS in both women and men. PMID:26774275

  2. Male Reproductive Toxicology: Environmental Exposures vs Reproductive Competence

    EPA Science Inventory

    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...

  3. Ultrasound in assisted reproductive technology.

    PubMed

    Porter, Misty Blanchette

    2008-05-01

    Transvaginal ultrasound-guided oocyte retrieval is the gold standard for in vitro fertilization (IVF) treatment. Despite its relative safety, oocyte retrieval is associated with risk to the adjacent pelvic organs, bleeding, and pelvic infection. The embryo transfer (ET) procedure is considered a crucial step in an IVF cycle. The success of the ET is dependent upon multiple factors including embryo quality, proper endometrial receptivity, and the technique by which the embryos are transferred. Optimizing the technique of ET would therefore provide the best chance for pregnancy. No standard evidence-based protocol exists, but ET with ultrasound guidance has been shown to significantly increase the chance of embryo implantation, an ongoing pregnancy, and a live birth and to improve the ease of transfer. Identifying appropriate ultrasound-guided simulation training techniques in ET would ensure adequate fellowship training without affecting the outcome of assisted reproductive technology cycles. PMID:18504701

  4. Preparing for Assisted Reproductive Technology

    MedlinePlus

    ... CDC Cancel Submit Search The CDC Assisted Reproductive Technology (ART) Note: Javascript is disabled or is not ... visit this page: About CDC.gov . Assisted Reproductive Technology (ART) What Is ART Patient Resources Preparing for ...

  5. Ethics of Reproductive Engineering

    ERIC Educational Resources Information Center

    Buuck, R. John

    1977-01-01

    Artificial insemination, in vitro fertilization, artificial placentas, and cloning are examined from a ethical viewpoint. The moral, social, and legal implications of reproductive engineering are considered important to biology as well as medicine. The author suggests that these ethical issues should be included in the biology curriculum and lists…

  6. Female Reproductive System.

    ERIC Educational Resources Information Center

    Hodge, N. J.

    This autoinstructional lesson can be used with health education and/or biology classes in a high school curriculum. It deals with the study of human development with emphasis on the female reproductive organs and cycles. The behavioral objectives are given, and the materials and equipment needed to gain these objectives are itemized. Fifteen…

  7. Reproductive cycles of deer.

    PubMed

    Asher, G W

    2011-04-01

    The cervids are a complex assemblage of taxa showing extreme diversity in morphology, physiology, ecology and geographical distribution. Reproductive strategies adopted by various species are also diverse, and include a range from highly seasonal to completely aseasonal birth patterns. The recent growth in knowledge on cervid reproduction is strongly biased towards the larger-bodied, gregarious mixed grazer-browser species that have adapted well to human management and commercialisation. These species tend to represent 'K-selected' climax species characterised by very productive annual breeding success, singleton births and long breeding life (10+ years). Conversely, we know relatively little about the reproductive patterns of the 'r-selected' smaller-bodied, solitary (and often highly territorial), forest-dwelling browser species, often characterised by great fecundity (twinning) and shorter breeding life (<10 years). This group includes many of the endangered cervid taxa. This review extends earlier reviews to include more recent work on cervid reproductive cycles, particularly in relation to environmental factors influencing gestation length. PMID:20884138

  8. Male Reproductive System.

    ERIC Educational Resources Information Center

    Turkington, B. A.

    This autoinstructional lesson deals with the study of the human body with emphasis on the life process of reproduction. It is a learning activity included in high school biology or health education classes. The behavioral objectives are listed and the equipment and materials needed to help the student gain these objectives are also included in the…

  9. Digital plus analog output encoder

    NASA Technical Reports Server (NTRS)

    Hafle, R. S. (Inventor)

    1976-01-01

    The disclosed encoder is adapted to produce both digital and analog output signals corresponding to the angular position of a rotary shaft, or the position of any other movable member. The digital signals comprise a series of binary signals constituting a multidigit code word which defines the angular position of the shaft with a degree of resolution which depends upon the number of digits in the code word. The basic binary signals are produced by photocells actuated by a series of binary tracks on a code disc or member. The analog signals are in the form of a series of ramp signals which are related in length to the least significant bit of the digital code word. The analog signals are derived from sine and cosine tracks on the code disc.

  10. Prenatal programming of neuroendocrine reproductive function.

    PubMed

    Evans, Neil P; Bellingham, Michelle; Robinson, Jane E

    2016-07-01

    It is now well recognized that the gestational environment can have long-lasting effects not only on the life span and health span of an individual but also, through potential epigenetic changes, on future generations. This article reviews the "prenatal programming" of the neuroendocrine systems that regulate reproduction, with a specific focus on the lessons learned using ovine models. The review examines the critical roles played by steroids in normal reproductive development before considering the effects of prenatal exposure to exogenous steroid hormones including androgens and estrogens, the effects of maternal nutrition and stress during gestation, and the effects of exogenous chemicals such as alcohol and environment chemicals. In so doing, it becomes evident that, to maximize fitness, the regulation of reproduction has evolved to be responsive to many different internal and external cues and that the GnRH neurosecretory system expresses a degree of plasticity throughout life. During fetal life, however, the system is particularly sensitive to change and at this time, the GnRH neurosecretory system can be "shaped" both to achieve normal sexually differentiated function but also in ways that may adversely affect or even prevent "normal function". The exact mechanisms through which these programmed changes are brought about remain largely uncharacterized but are likely to differ depending on the factor, the timing of exposure to that factor, and the species. It would appear, however, that some afferent systems to the GnRH neurons such as kisspeptin, may be critical in this regard as it would appear to be sensitive to a wide variety of factors that can program reproductive function. Finally, it has been noted that the prenatal programming of neuroendocrine reproductive function can be associated with epigenetic changes, which would suggest that in addition to direct effects on the exposed offspring, prenatal programming could have transgenerational effects on

  11. Reproductive patterns result from age-related sensitivity to resources and reproductive costs in a mammalian carnivore.

    PubMed

    Rauset, Geir Rune; Low, Matthew; Persson, Jens

    2015-12-01

    Although the effects of individual age, resource availability, and reproductive costs have been extensively studied to understand the causes of variation in reproductive output, there are almost no studies showing how these factors interact in explaining this variation. To examine this interaction, we used longitudinal demographic data from an 18-year study of 53 breeding female wolverines (Gulo gulo), and corresponding environmental data from their individual home ranges. Females showed a typical age-related pattern in reproductive output, with an initial increase followed by a senescent decline in later years. This pattern was largely driven by four processes: (1) physiological/behavioral maturation between ages two and three; (2) age-related differences in the costs of reproduction resulting in an initial increase, and then a declining probability of breeding two years in a row as individuals aged; (3) resource availability (reindeer [Rangifer tarandus] carcass abundance; mostly Eurasian lynx [Lynx lynx] kills) in the months preceding parturition, which influenced the probability of having cubs, but only for individuals that had successfully bred in the previous year; and (4) resource availability also influenced the cost of reproduction in an age-dependent manner, as prime age females that had bred in the previous year were more responsive to resource availability than those at other ages. This study demonstrates that by examining how drivers of reproductive variation interact, we can get a much clearer understanding of the mechanisms responsible for age-related patterns of reproduction. This has implications not only for general ecological theory, but will also allow better predictions of population resnonses to environmental changes or management based on a population's age-structure. PMID:26909422

  12. Telomeres and reproductive aging.

    PubMed

    Keefe, David L; Liu, Lin

    2009-01-01

    Infertility, miscarriage and aneuploid offspring increase with age in women, and meiotic dysfunction underlies reproductive aging. How aging disrupts meiotic function in women remains unclear, but as women increasingly delay having children, solving this problem becomes an urgent priority. Telomeres consist of a (TTAGGG)(n) repeated sequence and associated proteins at chromosome ends, mediate aging in mitotic cells and may also mediate aging during meiosis. Telomeres shorten both during DNA replication and from the response to oxidative DNA damage. Oocytes do not divide in adult mammals, but their precursors do replicate during fetal oogenesis; eggs ovulated from older females have traversed more mitotic cell cycles before entering meiosis during fetal oogenesis than eggs ovulated from younger females. Telomeres also would be expected to shorten from inefficient DNA repair of oxidative damage, because the interval between fetal oogenesis and ovulation is exceptionally prolonged in women. We have tested the hypothesis that telomere shortening disrupts meiosis by shortening telomeres experimentally in mice, which normally do not exhibit age-related meiotic dysfunction. Interestingly, mouse telomeres are much longer than human telomeres, but genetic or pharmacological shortening of mouse telomeres recapitulates in mice the human reproductive aging phenotype as the mouse telomeres reach the length of telomeres from older women. These observations led us to propose a telomere theory of reproductive aging. Moreover, chronological oxidative stress increases with reproductive aging, leading to DNA damage preferentially at (TTAGGG)(n) repeats. Finally, if telomeres shorten with aging, how do they reset across generations? Telomerase could not play a significant role in telomere elongation during early development, because this enzyme is not active until the blastocyst stage, well after the stage when telomere elongation takes place. Rather, telomeres lengthen during the

  13. Sense and Nonsense in Metabolic Control of Reproduction

    PubMed Central

    Schneider, Jill E.; Klingerman, Candice M.; Abdulhay, Amir

    2012-01-01

    An exciting synergistic interaction occurs among researchers working at the interface of reproductive biology and energy homeostasis. Reproductive biologists benefit from the theories, experimental designs, and methodologies used by experts on energy homeostasis while they bring context and meaning to the study of energy homeostasis. There is a growing recognition that identification of candidate genes for obesity is little more than meaningless reductionism unless those genes and their expression are placed in a developmental, environmental, and evolutionary context. Reproductive biology provides this context because metabolic energy is the most important factor that controls reproductive success and gonadal hormones affect energy intake, storage, and expenditure. Reproductive hormone secretion changes during development, and reproductive success is key to evolutionary adaptation, the process that most likely molded the mechanisms that control energy balance. It is likely that by viewing energy intake, storage, and expenditure in the context of reproductive success, we will gain insight into human obesity, eating disorders, diabetes, and other pathologies related to fuel homeostasis. This review emphasizes the metabolic hypothesis: a sensory system monitors the availability of oxidizable metabolic fuels and orchestrates behavioral motivation to optimize reproductive success in environments where energy availability fluctuates or is unpredictable. PMID:22649413

  14. Impact of Marine Drugs on Animal Reproductive Processes

    PubMed Central

    Silvestre, Francesco; Tosti, Elisabetta

    2009-01-01

    The discovery and description of bioactive substances from natural sources has been a research topic for the last 50 years. In this respect, marine animals have been used to extract many new compounds exerting different actions. Reproduction is a complex process whose main steps are the production and maturation of gametes, their activation, the fertilisation and the beginning of development. In the literature it has been shown that many substances extracted from marine organisms may have profound influence on the reproductive behaviour, function and reproductive strategies and survival of species. However, despite the central importance of reproduction and thus the maintenance of species, there are still few studies on how reproductive mechanisms are impacted by marine bioactive drugs. At present, studies in either marine and terrestrial animals have been particularly important in identifying what specific fine reproductive mechanisms are affected by marine-derived substances. In this review we describe the main steps of the biology of reproduction and the impact of substances from marine environment and organisms on the reproductive processes. PMID:20098597

  15. DEVELOPMENTAL EXPOSURE TO AN ENVIRONMENTAL ANDROGEN, 17 B TRENBOLONE, CAUSES REPRODUCTIVE MALFORMATIONS AND REDUCED REPRODUCTIVE OUTPUT IN FEMALE RATS

    EPA Science Inventory

    Recently, studies have detected environmental androgen-active chemicals in effluents from pulp mills and animal feedlot operations. One such chemical present in feedlot discharge is the growth promoter, trenbolone acetate. A primary metabolite of trenbolone acetate, 17ß trenbolon...

  16. Bateman revisited: the reproductive tactics of female primates.

    PubMed

    Drea, Christine M

    2005-11-01

    The breeding system of an animal population is thought to depend on the ability of one sex (usually the male) to acquire mates, either directly through association with females or indirectly through defense of the resources desired by females. The sex that contributes most to infant care (usually the female) is constrained by parental involvement and thereby limits reproduction of the opposite sex. Accordingly, males, but not females, enhance their reproductive success by acquiring additional mates. This classical view has emphasized the role of male-male competition in sexual selection, at the expense of fully exploring the potential for female choice. A more recent shift in focus has revealed substantial variation in female reproductive success and increasingly accentuates the importance of female intrasexual competition and male mate choice. A comparative review of primate reproduction, therefore, challenges expectations of male control and female compliance, and calls for a comprehensive treatment of costs and benefits that extends beyond conventional mention of heavy female investment versus male negligence or absenteeism. For individuals that manipulate their social environment or reproductive output, consideration of more subtle, even cryptic, aspects of female behavior and physiology (e.g., social strategizing, sexual solicitation or rejection, sexual advertisement or concealed ovulation, multiple mating, and reproductive failure) raises the question of whether females can be effectively 'monopolized.' Widespread patterns that counter Bateman's paradigm call for a reexamination of the predictions generated by dichotomizing gametes into 'expensive eggs' and 'cheap sperm,' and encourage continued mechanistic research focused on conception quality rather than quantity. PMID:21676842

  17. Reproductive failure and the major histocompatibility complex

    SciTech Connect

    Jin, K.; Gill, T.J. III; Ho, H.N.

    1995-06-01

    The association between HLA sharing and recurrent spontaneous abortion (RSA) was tested in 123 couples and the association between HLA sharing, and the outcome of treatment for unexplained infertility by in vitro fertilization (IVF) was tested in 76 couples, by using a new shared-allele test in order to identify more precisely the region of the major histocompatibility complex (MHC) influencing these reproductive defects. The shared-allele test circumvents the problem of rare alleles at HLA loci and at the same time provides a substantial gain in power over the simple {chi}{sup 2} test. Two statistical methods, a corrected homogeneity test and a bootstrap approach, were developed to compare the allele frequencies at each of the HLA-A, HLA-B, HLA-DR, and HLA-DQ loci; they were not statistically different amount the three patient groups and the control group. There was a significant excess of HLA-DR sharing in couples with RSA and a significant excess of HLA-DQ sharing in couples with unexplained infertility who failed treatment by IVF. These findings indicate that genes located in different parts of the class II region of the MHC affect different aspects of reproduction and strongly suggest that the sharing of HLA antigens per se is not the mechanism involved in the reproductive defects. The segment of the MHC that has genes affecting reproduction also has genes associated with different autoimmune diseases, and this juxtaposition may explain the association between reproductive defects and autoimmune diseases. 58 refs., 1 fig., 7 tabs.

  18. Endocannabinoids and Reproductive Events in Health and Disease.

    PubMed

    Battista, Natalia; Bari, Monica; Maccarrone, Mauro

    2015-01-01

    The lasting research on the endocannabinoid system (ECS) has now provided solid and convincing evidence that proves the detrimental effects of recreational drug abuse (a growing habit among teenagers) on fertility. Endocannabinoids (eCBs) affect reproductive events from gametogenesis to fertilization, from embryo implantation to the final outcome of pregnancy and, thus, they have been proposed as suitable biomarkers to predict the reproductive potential of male and female gametes in clinical practice. Novel tools for reproductive medicine are highly sought after, and here we report the latest findings on the impact of the ECS on fertility, demonstrating how basic research can be translated into new medical strategies. PMID:26408167

  19. Reproductive conflict and the separation of reproductive generations in humans

    PubMed Central

    Cant, Michael A.; Johnstone, Rufus A.

    2008-01-01

    An enduring puzzle of human life history is why women cease reproduction midway through life. Selection can favor postreproductive survival because older females can help their offspring to reproduce. But the kin-selected fitness gains of helping appear insufficient to outweigh the potential benefits of continued reproduction. Why then do women cease reproduction in the first place? Here, we suggest that early reproductive cessation in humans is the outcome of reproductive competition between generations, and we present a simple candidate model of how this competition will be resolved. We show that among primates exhibiting a postreproductive life span, humans exhibit an extraordinarily low degree of reproductive overlap between generations. The rapid senescence of the human female reproductive system coincides with the age at which, in natural fertility populations, women are expected to encounter reproductive competition from breeding females of the next generation. Several lines of evidence suggest that in ancestral hominids, this younger generation typically comprised immigrant females. In these circumstances, relatedness asymmetries within families are predicted to give younger females a decisive advantage in reproductive conflict with older females. A model incorporating both the costs of reproductive competition and the benefits of grandmothering can account for the timing of reproductive cessation in humans and so offers an improved understanding of the evolution of menopause. PMID:18378891

  20. Mathematics and the Heart: Understanding Cardiac Output

    ERIC Educational Resources Information Center

    Champanerkar, Jyoti

    2013-01-01

    This paper illustrates a biological application of the concepts of relative change and area under a curve, from mathematics. We study two biological measures "relative change in cardiac output" and "cardiac output", which are predictors of heart blockages and other related ailments. Cardiac output refers to the quantity of…

  1. Demographic consequences of greater clonal than sexual reproduction in Dicentra canadensis.

    PubMed

    Lin, Chia-Hua; Miriti, Maria N; Goodell, Karen

    2016-06-01

    Clonality is a widespread life history trait in flowering plants that may be essential for population persistence, especially in environments where sexual reproduction is unpredictable. Frequent clonal reproduction, however, could hinder sexual reproduction by spatially aggregating ramets that compete with seedlings and reduce inter-genet pollination. Nevertheless, the role of clonality in relation to variable sexual reproduction in population dynamics is often overlooked. We combined population matrix models and pollination experiments to compare the demographic contributions of clonal and sexual reproduction in three Dicentra canadensis populations, one in a well-forested landscape and two in isolated forest remnants. We constructed stage-based transition matrices from 3 years of census data to evaluate annual population growth rates, λ. We used loop analysis to evaluate the relative contribution of different reproductive pathways to λ. Despite strong temporal and spatial variation in seed set, populations generally showed stable growth rates. Although we detected some pollen limitation of seed set, manipulative pollination treatments did not affect population growth rates. Clonal reproduction contributed significantly more than sexual reproduction to population growth in the forest remnants. Only at the well-forested site did sexual reproduction contribute as much as clonal reproduction to population growth. Flowering plants were more likely to transition to a smaller size class with reduced reproductive potential in the following year than similarly sized nonflowering plants, suggesting energy trade-offs between sexual and clonal reproduction at the individual level. Seed production had negligible effects on growth and tuber production of individual plants. Our results demonstrate that clonal reproduction is vital for population persistence in a system where sexual reproduction is unpredictable. The bias toward clonality may be driven by low fitness returns

  2. Testing PSHA Output via Precariously Balanced Rocks

    NASA Astrophysics Data System (ADS)

    Purvance, M. D.; Brune, J. N.; Anooshehpoor, R.

    2005-12-01

    Purvance (2005) has shown that the overturning responses of precariously balanced rocks (PBRs) depend on the PBR shapes, sizes, and the vector of ground motion intensity measures including PGA and either PGV, SA@1sec, or SA@2sec. This formulation allows one to quantify the overturning probability of an object that has been exposed to a ground motion time history with specified peak parameters (e.g. PGA and PGV). Vector-valued PSHA (VPSHA) provides a methodology to estimate the rate of occurrence of all ground motions. Combining the VPSHA output with the PBR fragility results in the rate of PBR overturning. In this way, one can compare the PBR age with the estimated failure date given the assumptions inherent in the VPSHA calculation. This study focuses on the variability of estimated failure dates of PBRs as a function of attenuation relations utilized in the VPSHA calculations. The following attenuation relations have been investigated: Abrahamson and Silva (1997), Boore et al. (1997), Abrahamson (2005), and Gregor et al. (2002). The Boore et al. (1997) and Abrahamson (2005) relations produce ground motion models that are more consistent with the PBRs in southern California than the Abrahamson and Silva (1997) and Gregor et al. (2002) relations. It is apparent that the addition of recent data (e.g. Chi-Chi, Izmit) in the development of the Abrahamson (2005) attenuation relation significantly affects the VPSHA output. These findings highlight the utility of this methodology to test alternate attenuation relations such as those produced by the NGA initiative. In addition, varying RELM models may be assessed for consistency with PBRs via the described methodology.

  3. Beyond the metabolic role of ghrelin: a new player in the regulation of reproductive function.

    PubMed

    Muccioli, Giampiero; Lorenzi, Teresa; Lorenzi, Maria; Ghè, Corrado; Arnoletti, Elisa; Raso, Giuseppina Mattace; Castellucci, Mario; Gualillo, Oreste; Meli, Rosaria

    2011-12-01

    Ghrelin is a gastric peptide, discovered by Kojima et al. (1999) [55] as a result of the search for an endogenous ligand interacting with the "orphan receptor" GHS-R1a (growth hormone secretagogue receptor type 1a). Ghrelin is composed of 28 aminoacids and is produced mostly by specific cells of the stomach, by the hypothalamus and hypophysis, even if its presence, as well as that of its receptors, has been demonstrated in many other tissues, not least in gonads. Ghrelin potently stimulates GH release and participates in the regulation of energy homeostasis, increasing food intake, decreasing energy output and exerting a lipogenetic effect. Furthermore, ghrelin influences the secretion and motility of the gastrointestinal tract, especially of the stomach, and, above all, profoundly affects pancreatic functions. Despite of these previously envisaged activities, it has recently been hypothesized that ghrelin regulates several aspects of reproductive physiology and pathology. In conclusion, ghrelin not only cooperates with other neuroendocrine factors, such as leptin, in the modulation of energy homeostasis, but also has a crucial role in the regulation of the hypothalamic-pituitary gonadal axis. In the current review we summarize the main targets of this gastric peptide, especially focusing on the reproductive system. PMID:22074955

  4. Power over reproduction in social hymenoptera.

    PubMed Central

    Beekman, Madeleine; Ratnieks, Francis L W

    2003-01-01

    Inclusive fitness theory has been very successful in predicting and explaining much of the observed variation in the reproductive characteristics of insect societies. For example, the theory correctly predicts sex-ratio biasing by workers in relation to the queen's mating frequency. However, within an insect society there are typically multiple reproductive optima, each corresponding to the interest of different individual(s) or parties of interest. When multiple optima occur, which party's interests prevail? Presumably, the interests of the party with the greatest 'power'; the ability to do or act. This article focuses on factors that influence power over colony reproduction. In particular, we seek to identify the principles that may cause different parties of interest to have greater or lesser power. In doing this, we discuss power from two different angles. On the one hand, we discuss general factors based upon non-idiosyncratic biological features (e.g. information, access to and ability to process food) that are likely to be important to all social Hymenoptera. On the other hand, we discuss idiosyncratic factors that depend upon the biology of a taxon at any hierarchical level. We propose that a better understanding of the diversity of reproductive characteristics of insect societies will come from combining inclusive fitness theory with a wide range of other factors that affect relative power in a conflict situation. PMID:14561330

  5. Reproductive senescence in a cooperatively breeding mammal.

    PubMed

    Sharp, Stuart P; Clutton-Brock, Tim H

    2010-01-01

    1. Senescence (or 'ageing') is a widespread and important process in wild animal populations, but variation in ageing patterns within and between species is poorly understood. 2. In cooperatively breeding species, the costs of reproduction are shared between breeders and one or more helpers. The effects of ageing in breeders may therefore be moderated by the presence of helpers, but there have been very few studies of senescence patterns in natural populations of cooperative breeders. 3. Here, we use 13 years of data from a long-term study population of wild meerkats (Suricata suricatta) to investigate age-related changes in several traits known to be key components of reproductive success in females of this species. 4. Four of the six traits studied exhibited significant declines with age, indicating senescence. Litter size, the number of litters produced per year and the number of pups that survived to emergence from the natal burrow per year all increased with female age up to a peak at c. 4 years, and declined steeply thereafter; the mean pup weight at emergence in a given litter declined steadily from age zero. 5. These results provide the first evidence of reproductive senescence in a wild population of a cooperatively breeding vertebrate. Breeding success declined with age despite the sharing of reproductive costs in this species, but further study is needed to investigate whether helping affects other aspects of senescence, including survival. PMID:19758306

  6. Some aspects of the NASTRAN program output

    NASA Technical Reports Server (NTRS)

    Gregory, D. J.

    1972-01-01

    The NASTRAN program output is discussed from a structural analysts point of view, and the simple modifications which were made to the program in order to improve it are also described. The convenience of the output for use in original design work is critically appraised and compared with the output from ASTRAL. It is shown that considerable hand calculation is necessary in order to extract useful load distribution data from the available NASTRAN output. For this reason, some effort was directed toward providing additional force output for the NASTRAN shear panel element.

  7. Model output: fact or artefact?

    NASA Astrophysics Data System (ADS)

    Melsen, Lieke

    2015-04-01

    As a third-year PhD-student, I relatively recently entered the wonderful world of scientific Hydrology. A science that has many pillars that directly impact society, for example with the prediction of hydrological extremes (both floods and drought), climate change, applications in agriculture, nature conservation, drinking water supply, etcetera. Despite its demonstrable societal relevance, hydrology is often seen as a science between two stools. Like Klemeš (1986) stated: "By their academic background, hydrologists are foresters, geographers, electrical engineers, geologists, system analysts, physicists, mathematicians, botanists, and most often civil engineers." Sometimes it seems that the engineering genes are still present in current hydrological sciences, and this results in pragmatic rather than scientific approaches for some of the current problems and challenges we have in hydrology. Here, I refer to the uncertainty in hydrological modelling that is often neglected. For over thirty years, uncertainty in hydrological models has been extensively discussed and studied. But it is not difficult to find peer-reviewed articles in which it is implicitly assumed that model simulations represent the truth rather than a conceptualization of reality. For instance in trend studies, where data is extrapolated 100 years ahead. Of course one can use different forcing datasets to estimate the uncertainty of the input data, but how to prevent that the output is not a model artefact, caused by the model structure? Or how about impact studies, e.g. of a dam impacting river flow. Measurements are often available for the period after dam construction, so models are used to simulate river flow before dam construction. Both are compared in order to qualify the effect of the dam. But on what basis can we tell that the model tells us the truth? Model validation is common nowadays, but validation only (comparing observations with model output) is not sufficient to assume that a

  8. Model output: fact or artefact?

    NASA Astrophysics Data System (ADS)

    Melsen, Lieke

    2015-04-01

    As a third-year PhD-student, I relatively recently entered the wonderful world of scientific Hydrology. A science that has many pillars that directly impact society, for example with the prediction of hydrological extremes (both floods and drought), climate change, applications in agriculture, nature conservation, drinking water supply, etcetera. Despite its demonstrable societal relevance, hydrology is often seen as a science between two stools. Like Klemeš (1986) stated: "By their academic background, hydrologists are foresters, geographers, electrical engineers, geologists, system analysts, physicists, mathematicians, botanists, and most often civil engineers." Sometimes it seems that the engineering genes are still present in current hydrological sciences, and this results in pragmatic rather than scientific approaches for some of the current problems and challenges we have in hydrology. Here, I refer to the uncertainty in hydrological modelling that is often neglected. For over thirty years, uncertainty in hydrological models has been extensively discussed and studied. But it is not difficult to find peer-reviewed articles in which it is implicitly assumed that model simulations represent the truth rather than a conceptualization of reality. For instance in trend studies, where data is extrapolated 100 years ahead. Of course one can use different forcing datasets to estimate the uncertainty of the input data, but how to prevent that the output is not a model artefact, caused by the model structure? Or how about impact studies, e.g. of a dam impacting river flow. Measurements are often available for the period after dam construction, so models are used to simulate river flow before dam construction. Both are compared in order to qualify the effect of the dam. But on what basis can we tell that the model tells us the truth? Model validation is common nowadays, but validation only (comparing observations with model output) is not sufficient to assume that a

  9. Personality and reproductive fitness.

    PubMed

    Eaves, L J; Martin, N G; Heath, A C; Hewitt, J K; Neale, M C

    1990-09-01

    The relationship between reproductive success (number of biological children) and personality was explored in 1101 postmenopausal females from the Australian twin registry. The quadratic response surface relating fitness to extraversion (E) and neuroticism (N) showed a saddle point at intermediate levels of E and N. Selection was shown to be stabilizing, i.e., having an intermediate optimum, along the axis low E, low N-high E, high N and more mildly disruptive, having greater fitness in the extremes, along the axis low N, high E-high N, low E. Neither dimension of personality considered by itself showed a significant linear or quadratic relationship to reproductive success. Sections through the fitness surface, however, show selection tends to favor high neuroticism levels in introverts and low neuroticism levels in extroverts. PMID:2288546

  10. Ghrelin and reproductive disorders.

    PubMed

    Repaci, Andrea; Gambineri, Alessandra; Pagotto, Uberto; Pasquali, Renato

    2011-06-20

    Ghrelin is an important factor involved in most of the metabolic and hormonal signals which adapt the reproductive functions in conditions of altered energy balance. Moreover, the coordinated role of leptin and ghrelin appears in fact to have a specific role in the regulation of puberty. Systemic action of ghrelin on the reproductive axis involves the control of the hypothalamic-pituitary-gondal axis. In addition, it has been shown that ghrelin may directly act at a gonadal level in both females and males. Available data also demonstrate that sex steroid hormones and gonadotropins may in turn regulate the gonadal effect of ghrelin, as documented by studies performed in females with the polycystic ovary syndrome and in hypogonadal men. Notably, recent studies also confirm a potentially important role for ghrelin in fetal and neonatal energy balance, and specifically in allowing fetal adaptation to an adverse intrauterine environment. PMID:21453749

  11. Optical Waveguide Output Couplers Fabricated in Polymers

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Abushagur, Mustafa A. G.; Ashley, Paul R.; Johnson-Cole, Helen

    1998-01-01

    Waveguide output couplers fabricated in Norland Optical Adhesive (NOA) #81 and AMOCO Ultradel 9020D polyimide are investigated. The output couplers are implemented using periodic relief gratings on a planar waveguide. Design theory of the couplers is based on the perturbation approach. Coupling of light from waveguide propagation modes to output radiation modes is described by coupled mode theory and the transmission line approximation of the perturbed area (grating structure). Using these concepts, gratings can be accurately designed to output a minimum number of modes at desired output angles. Waveguide couplers were designed using these concepts. These couplers were fabricated and analyzed for structural accuracy, output beam accuracy, and output efficiency. The results for the two different materials are compared.

  12. Introduction: Imaging in reproduction.

    PubMed

    Sella, Tamar; Laufer, Neri

    2016-06-01

    The authors of this Views and Reviews outline in detail the indispensable role of imaging tools-ultrasound, computed tomography, and magnetic resonance imaging-in the diagnosis and treatment of female and male factor infertility. Equipment producing diagnostic images, coupled with ever-increasing computing power, will pave the way for novel functional dynamic studies that will expand the understanding of reproductive processes and their management. PMID:27117374

  13. Interventions in reproduction.

    PubMed

    Sheriff, D S; Sheriff, S Omer

    2006-01-01

    Assisted reproductive technology has helped many childless couples. It has also raised questions about how appropriate the technology might be in different situations. How we understand parenthood is crucial in taking a stand on such scientific intervention. It is suggested that physicians should decide on offering artificial insemination, surrogacy and in-vitro fertilisation only after considering if the child will have good parents and if there will be legal complications from the use of the technology. PMID:17223683

  14. Whither Artificial Reproduction?

    PubMed Central

    Percival-Smith, Robin

    1985-01-01

    Artificial reproduction now offers sub fertile couples a number of options which raise scientific and ethical questions. This article discusses the Canadian and British experiences in formulating regulations and legislation in this important field. Current work on mammalian embryo research foretells the direction which human research will take. This article stresses the need for family physicians' participation in the ethical decisions that accompany these new developments. PMID:21274181

  15. Grey Component Replacement Research, Modelling Tone And Color Reproduction

    NASA Astrophysics Data System (ADS)

    Fisch, Richard S.

    1990-06-01

    Four different scanning Color Electronic Pagination System (CEPS) devices were tested to study their conventional and Grey Component Replacement/Undercolor Addition (GCR/UCA) tone and color response in the 4 color Positive Acting Offset Lithographic printing process. A common transparency input and ganged printing output was used. Inter and intra machine differences are disclosed. A new depiction of the full tone reproduction characteristics is presented for several different levels of GCR/UCA and conventional printing.

  16. Clonal reproduction in fungi

    PubMed Central

    Taylor, John W.; Hann-Soden, Christopher; Branco, Sara; Sylvain, Iman; Ellison, Christopher E.

    2015-01-01

    Research over the past two decades shows that both recombination and clonality are likely to contribute to the reproduction of all fungi. This view of fungi is different from the historical and still commonly held view that a large fraction of fungi are exclusively clonal and that some fungi have been exclusively clonal for hundreds of millions of years. Here, we first will consider how these two historical views have changed. Then we will examine the impact on fungal research of the concept of restrained recombination [Tibayrenc M, Ayala FJ (2012) Proc Natl Acad Sci USA 109 (48):E3305–E3313]. Using animal and human pathogenic fungi, we examine extrinsic restraints on recombination associated with bottlenecks in genetic variation caused by geographic dispersal and extrinsic restraints caused by shifts in reproductive mode associated with either disease transmission or hybridization. Using species of the model yeast Saccharomyces and the model filamentous fungus Neurospora, we examine intrinsic restraints on recombination associated with mating systems that range from strictly clonal at one extreme to fully outbreeding at the other and those that lie between, including selfing and inbreeding. We also consider the effect of nomenclature on perception of reproductive mode and a means of comparing the relative impact of clonality and recombination on fungal populations. Last, we consider a recent hypothesis suggesting that fungi thought to have the most severe intrinsic constraints on recombination actually may have the fewest. PMID:26195774

  17. [Reproductive or domestic work].

    PubMed

    Larranaga, I; Arregui, B; Arpal, J

    2004-05-01

    The objective of this article is to describe the evolution of reproductive work and to analyse those factors related to its distribution. The analysis has been based on data from various Time-use Surveys (Women Institute 1993, 1996, 2001) as well as on data from different regional surveys: Andalusia, the Basque Country, Madrid and the metropolitan area of Barcelona. In the period 1993-2001, the amount of time devoted by men to housekeeping in Spain increased by 35% while women's time declined by 5%. Yet, in 2001 women's dedication to housekeeping was twice that of men's (7.2 vs 3.1 h daily). However, the imbalance in sharing of housework declined among younger people. Union formation and growing family size increase women's housework intensifying the uneven distribution of household chores. When women are employed and have higher educational and income levels, dedication to household tasks decreases and gender inequalities are reduced. In spite of growing male participation in housework, reproductive work is still mainly women's responsibility. The recent legal, social and cultural changes have not been able to eradicate the traditional model of assigning reproductive work in the home. PMID:15171855

  18. Perspectives of reproductive health.

    PubMed

    van Balen, F; Visser, A P

    1997-05-01

    This issue of Patient Education and Counseling is dedicated to reproductive health. The main focus is infertility as it is experienced in different of our world. In western societies, medical breakthroughs give couples with fertility problems a good chance to have a child. However, in many developing societies adequate medical treatment is only available for the upper classes, and many women keep going to traditional healers. In addition, the social consequences of childlessness are much greater than in western societies. Another focus of this issue is negative experiences regarding pregnancy. A very distressing experience is late pregnancy loss. Late pregnancy loss is different from infertility with respect to the tangibility of an object of grief, though it may also result in permanent childlessness. Other aspects of negative pregnancy experiences are exceptional physical reactions and recurrent induced abortions. Furthermore, two other elements of reproductive health are addressed in this issue: STD among female adolescents and gender aspects of gene technology. Finally, the ramifications of these various aspects of reproductive health on education and counseling are discussed. PMID:9197797

  19. Improving worldwide reproductive health.

    PubMed

    Geary, J

    1993-01-01

    The 14th International Federation of Gynaecology and Obstetrics World Congress will be held in Montreal, Canada, in 1994, under the auspices of the Society of Obstetricians and Gynecologists of Canada. The World Congress will 1) promote and facilitate international cooperation in the field of obstetrics and gynecology, 2) develop and improve the exchange of information and ideas, and 3) encourage the adoption of an international perspective on issues of concern. The 1994 program will survey recent research advances and introduce new equipment, instruments, and pharmaceuticals. Issues addressed will include maternal mortality, reproductive technologies, continuing education, malignancy, family planning, and contraception. The Conference's symposia, industry-sponsored events, and cultural activities are being designed to increase speaker-audience interaction and to stimulate debate and the exchange of views. The continuing education goals are 1) to encourage appropriate research with valid and applicable results and 2) to extend the patient-counseling abilities of participating physicians. Canada's socialized health care system, which carefully scrutinizes new expensive technologies, will be highlighted for the international delegates. The scientific program will include 1) general topics 2) reproductive endocrinology, 3) maternal/fetal medicine, and 4) gynecological oncology. Poster sessions followed by open discourses and free communications sessions will facilitate the exchange of views and information. The overall goal of the conference is to improve reproductive health care for mothers and babies worldwide. PMID:12318476

  20. Stress and the reproductive axis.

    PubMed

    Toufexis, D; Rivarola, M A; Lara, H; Viau, V

    2014-09-01

    There exists a reciprocal relationship between the hypothalamic-pituitary-adrenal (HPA) and the hypothalamic-pituitary-gonadal (HPG) axes, wherein the activation of one affects the function of the other and vice versa. For example, both testosterone and oestrogen modulate the response of the HPA axis, whereas activation of the stress axis, especially activation that is repeating or chronic, has an inhibitory effect upon oestrogen and testosterone secretion. Alterations in maternal care can produce significant effects on both HPG and HPA physiology, as well as behaviour in the offspring at adulthood. For example, changes in reproductive behaviour induced by altered maternal care may alter the expression of sex hormone receptors such as oestrogen receptor (ER)α that govern sexual behaviour, and may be particularly important in determining the sexual strategies utilised by females. Stress in adulthood continues to mediate HPG activity in females through activation of a sympathetic neural pathway originating in the hypothalamus and releasing norepinephrine into the ovary, which produces a noncyclic anovulatory ovary that develops cysts. In the opposite direction, sex differences and sex steroid hormones regulate the HPA axis. For example, although serotonin (5-HT) has a stimulatory effect on the HPA axis in humans and rodents that is mediated by the 5-HT1A receptor, only male rodents respond to 5-HT1A antagonism to show increased corticosterone responses to stress. Furthermore, oestrogen appears to decrease 5-HT1A receptor function at presynaptic sites, yet increases 5-HT1A receptor expression at postsynaptic sites. These mechanisms could explain the heightened stress HPA axis responses in females compared to males. Studies on female rhesus macaques show that chronic stress in socially subordinate female monkeys produces a distinct behavioural phenotype that is largely unaffected by oestrogen, a hyporesponsive HPA axis that is hypersensitive to the modulating effects

  1. Stress and the Reproductive Axis

    PubMed Central

    Toufexis, Donna; Rivarola, Maria Angelica; Lara, Hernan; Viau, Victor

    2014-01-01

    There exists a reciprocal relationship between the hypothalamic-pituitary-adrenal (HPA) and the hypothalamic-pituitary-gonadal (HPG) axes wherein the activation of one affects the function of the other and vice versa. For instance, both testosterone and oestrogen modulate the response of the HPA axis, while activation of the stress axis, especially activation that is repeating or chronic, has an inhibitory effect upon oestrogen and testosterone secretion. Alterations in maternal care can produce significant effects on both HPG and HPA physiology and behaviour in the offspring at adulthood. For example, changes in reproductive behaviour induced by altered maternal care may alter the expression of sex hormone receptors like ERα that govern sexual behaviour, and may be particularly important in determining the sexual strategies utilized by females. Stress in adulthood continues to mediate HPG activity in females through activation of a sympathetic neural pathway originating in the hypothalamus and releasing norepinephrine (NE) into the ovary, which produces a non-cyclic anovulatory ovary that develops cysts. In the opposite direction, sex differences and sex steroid hormones regulate the HPA axis. For example, although serotonin (5-HT) has a stimulatory effect on the HPA axis in humans and rodents that is mediated by the 5-HT1A receptor, only male rodents respond to 5-HT1A antagonism to show increased corticosterone responses to stress. Furthermore, oestrogen appears to decrease 5-HT1A receptor function at presynaptic sites, yet increase 5-HT1A receptor expression at postsynaptic sites. These mechanisms could explain heightened stress HPA axis responses in females compared to males. Studies on female rhesus macaques show that chronic stress in socially subordinate female monkeys produces a distinct behavioral phenotype that is largely unaffected by oestrogen, a hypo-responsive HPA axis that is hypersensitive to the modulating effects of oestrogen, and changes in 5-HT

  2. Rainfall during parental care reduces reproductive and survival components of fitness in a passerine bird

    PubMed Central

    Öberg, Meit; Arlt, Debora; Pärt, Tomas; Laugen, Ane T; Eggers, Sönke; Low, Matthew

    2015-01-01

    Adverse weather conditions during parental care may have direct consequences for offspring production, but longer-term effects on juvenile and parental survival are less well known. We used long-term data on reproductive output, recruitment, and parental survival in northern wheatears (Oenanthe oenanthe) to investigate the effects of rainfall during parental care on fledging success, recruitment success (juvenile survival), and parental survival, and how these effects related to nestling age, breeding time, habitat quality, and parental nest visitation rates. While accounting for effects of temperature, fledging success was negatively related to rainfall (days > 10 mm) in the second half of the nestling period, with the magnitude of this effect being greater for breeding attempts early in the season. Recruitment success was, however, more sensitive to the number of rain days in the first half of the nestling period. Rainfall effects on parental survival differed between the sexes; males were more sensitive to rain during the nestling period than females. We demonstrate a probable mechanism driving the rainfall effects on reproductive output: Parental nest visitation rates decline with increasing amounts of daily rainfall, with this effect becoming stronger after consecutive rain days. Our study shows that rain during the nestling stage not only relates to fledging success but also has longer-term effects on recruitment and subsequent parental survival. Thus, if we want to understand or predict population responses to future climate change, we need to consider the potential impacts of changing rainfall patterns in addition to temperature, and how these will affect target species' vital rates. PMID:25691962

  3. Rainfall during parental care reduces reproductive and survival components of fitness in a passerine bird.

    PubMed

    Öberg, Meit; Arlt, Debora; Pärt, Tomas; Laugen, Ane T; Eggers, Sönke; Low, Matthew

    2015-01-01

    Adverse weather conditions during parental care may have direct consequences for offspring production, but longer-term effects on juvenile and parental survival are less well known. We used long-term data on reproductive output, recruitment, and parental survival in northern wheatears (Oenanthe oenanthe) to investigate the effects of rainfall during parental care on fledging success, recruitment success (juvenile survival), and parental survival, and how these effects related to nestling age, breeding time, habitat quality, and parental nest visitation rates. While accounting for effects of temperature, fledging success was negatively related to rainfall (days > 10 mm) in the second half of the nestling period, with the magnitude of this effect being greater for breeding attempts early in the season. Recruitment success was, however, more sensitive to the number of rain days in the first half of the nestling period. Rainfall effects on parental survival differed between the sexes; males were more sensitive to rain during the nestling period than females. We demonstrate a probable mechanism driving the rainfall effects on reproductive output: Parental nest visitation rates decline with increasing amounts of daily rainfall, with this effect becoming stronger after consecutive rain days. Our study shows that rain during the nestling stage not only relates to fledging success but also has longer-term effects on recruitment and subsequent parental survival. Thus, if we want to understand or predict population responses to future climate change, we need to consider the potential impacts of changing rainfall patterns in addition to temperature, and how these will affect target species' vital rates. PMID:25691962

  4. Phenology of sexual reproduction in the common coral reef sponge, Carteriospongia foliascens

    NASA Astrophysics Data System (ADS)

    Abdul Wahab, M. A.; de Nys, R.; Webster, N.; Whalan, S.

    2014-06-01

    Understanding processes that contribute to population maintenance is critical to the management and conservation of species. Despite this, very little is currently known about the reproductive biology of Great Barrier Reef (GBR) sponge species. Here, we established reproductive parameters including mode of sexuality and development, seasonality, sex ratios, gametogenesis, reproductive output, and size at sexual maturity for the common phototrophic intertidal sponge, Carteriospongia foliascens, in the central GBR over two reproductive cycles. A population sexual productivity index (PoSPi) integrating key reproductive parameters was formulated to compare population larval supply over time. This study shows that C. foliascens is reproductive all year round, gonochoric and viviparous, with larvae developing asynchronously throughout the mesohyl. The influence of environmental parameters relevant to C. foliascens reproduction [i.e., sea surface temperature (SST), photoperiod, and rainfall] was also examined, and SST was found to have the most significant effect on phenology. C. foliascens reproduction exhibited annual mono-cyclic patterns closely resembling SST fluctuations. Reproductive output was depressed at low SST (<23 °C) and increased at temperatures above 23 °C. Peak sperm release occurred at temperatures above 25 °C, while peak larval release occurred during the annual temperature maxima (>28 °C). A twofold increase in maximum larval production (PoSPi) in C. foliascens was observed in the second reproductive cycle, following a depressed PoSPi in the first cycle. This reduction in PoSPi in the first reproductive cycle was associated with elevated SST and rainfall, coinciding with one of the strongest La Niña events on record.

  5. PREVIMER : Meteorological inputs and outputs

    NASA Astrophysics Data System (ADS)

    Ravenel, H.; Lecornu, F.; Kerléguer, L.

    2009-09-01

    PREVIMER is a pre-operational system aiming to provide a wide range of users, from private individuals to professionals, with short-term forecasts about the coastal environment along the French coastlines bordering the English Channel, the Atlantic Ocean, and the Mediterranean Sea. Observation data and digital modelling tools first provide 48-hour (probably 96-hour by summer 2009) forecasts of sea states, currents, sea water levels and temperatures. The follow-up of an increasing number of biological parameters will, in time, complete this overview of coastal environment. Working in partnership with the French Naval Hydrographic and Oceanographic Service (Service Hydrographique et Océanographique de la Marine, SHOM), the French National Weather Service (Météo-France), the French public science and technology research institute (Institut de Recherche pour le Développement, IRD), the European Institute of Marine Studies (Institut Universitaire Européen de la Mer, IUEM) and many others, IFREMER (the French public institute fo marine research) is supplying the technologies needed to ensure this pertinent information, available daily on Internet at http://www.previmer.org, and stored at the Operational Coastal Oceanographic Data Centre. Since 2006, PREVIMER publishes the results of demonstrators assigned to limited geographic areas and to specific applications. This system remains experimental. The following topics are covered : Hydrodynamic circulation, sea states, follow-up of passive tracers, conservative or non-conservative (specifically of microbiological origin), biogeochemical state, primary production. Lastly, PREVIMER provides researchers and R&D departments with modelling tools and access to the database, in which the observation data and the modelling results are stored, to undertake environmental studies on new sites. The communication will focus on meteorological inputs to and outputs from PREVIMER. It will draw the lessons from almost 3 years during

  6. Natural arsenic contaminated diets perturb reproduction in fish.

    PubMed

    Boyle, David; Brix, Kevin V; Amlund, Heidi; Lundebye, Anne-Katrine; Hogstrand, Christer; Bury, Nic R

    2008-07-15

    The toxicological effect of natural diets elevated in metals on reproduction in fish is poorly understood. The reproductive output of zebrafish fed the polychaete Nereis diversicolor collected from a metal-impacted estuary, Restronguet Creek, Cornwall, UK, was compared to fish fed N. diversicolor collected from a nonmetal impacted estuary, Blackwater, Essex, UK. Fish fed the metal laden N. diversicolorfor 68 days showed reduced reproductive output, characterized by reduced cumulative egg production (47%), cumulative number of spawns (30%), as well as reduced average number of eggs produced per spawn and % hatch rate. The mRNA transcript levels of the egg-yolk protein vitellogenin was also reduced 1.5 fold in the livers of female fish fed metal-laden N. diversicolor. No difference was seen between the lipid, protein, or moisture content of the two diets and no difference in growth was seen between the two fish populations. The Restronguet Creek polychaetes have elevated arsenic, cadmium, copper, zinc, lead, and silver body burdens, but the only element found to accumulate in the tissues of zebrafish fed this diet was As. The As in these N. diversicolor was found to be predominantly potentially toxic inorganic As species, 58% of total As content, which is unusual for aquatic organisms where arsenic is typically biotransformed into less toxic organoarsenical compounds. These results demonstrate that reproduction in fish is a sensitive target of exposure to a natural diet contaminated with As and this exposure route could be of significance to the health of fish populations. PMID:18754393

  7. Size does matter: An assessment of reproductive potential in seahorses.

    PubMed

    Faleiro, Filipa; Almeida, Armando J; Ré, Pedro; Narciso, Luís

    2016-07-01

    In most animals, the mother plays the key role in reproduction, but male pregnancy in seahorses raises the question of whether the female still is the only determinant of offspring size or if she shares some responsibility with the male. This study evaluates the effects of both male and female size on the reproductive output of the long-snouted seahorse, Hippocampus guttulatus. Results demonstrated that, with regard to reproductive potential, the bigger the better. Seahorses preferred similar-sized or larger mates. Larger females produced bigger eggs with larger yolk reserves. Larger males had larger brood pouches, but did not produced larger broods. Male size was negatively correlated with embryo density and positively correlated with juvenile size. Both parents proved to play a decisive role in the reproductive output of this species. Newborn juveniles from the same parents were 15% bigger and 30% heavier when incubated in smaller and lower-density broods. This trade-off between the number and size of embryos inside the brood pouch clearly indicates a limited carrying capacity of the male, and demonstrates that the size of newborn seahorses can be, in part, paternally determined. PMID:27062576

  8. Reproductive Capability Is Associated with Lifespan and Cause of Death in Companion Dogs

    PubMed Central

    Hoffman, Jessica M.; Creevy, Kate E.; Promislow, Daniel E. L.

    2013-01-01

    Reproduction is a risky affair; a lifespan cost of maintaining reproductive capability, and of reproduction itself, has been demonstrated in a wide range of animal species. However, little is understood about the mechanisms underlying this relationship. Most cost-of-reproduction studies simply ask how reproduction influences age at death, but are blind to the subjects' actual causes of death. Lifespan is a composite variable of myriad causes of death and it has not been clear whether the consequences of reproduction or of reproductive capability influence all causes of death equally. To address this gap in understanding, we compared causes of death among over 40,000 sterilized and reproductively intact domestic dogs, Canis lupus familiaris. We found that sterilization was strongly associated with an increase in lifespan, and while it decreased risk of death from some causes, such as infectious disease, it actually increased risk of death from others, such as cancer. These findings suggest that to understand how reproduction affects lifespan, a shift in research focus is needed. Beyond the impact of reproduction on when individuals die, we must investigate its impact on why individuals die, and subsequently must identify the mechanisms by which these causes of death are influenced by the physiology associated with reproductive capability. Such an approach may also clarify the effects of reproduction on lifespan in people. PMID:23613790

  9. Reproductive capability is associated with lifespan and cause of death in companion dogs.

    PubMed

    Hoffman, Jessica M; Creevy, Kate E; Promislow, Daniel E L

    2013-01-01

    Reproduction is a risky affair; a lifespan cost of maintaining reproductive capability, and of reproduction itself, has been demonstrated in a wide range of animal species. However, little is understood about the mechanisms underlying this relationship. Most cost-of-reproduction studies simply ask how reproduction influences age at death, but are blind to the subjects' actual causes of death. Lifespan is a composite variable of myriad causes of death and it has not been clear whether the consequences of reproduction or of reproductive capability influence all causes of death equally. To address this gap in understanding, we compared causes of death among over 40,000 sterilized and reproductively intact domestic dogs, Canis lupus familiaris. We found that sterilization was strongly associated with an increase in lifespan, and while it decreased risk of death from some causes, such as infectious disease, it actually increased risk of death from others, such as cancer. These findings suggest that to understand how reproduction affects lifespan, a shift in research focus is needed. Beyond the impact of reproduction on when individuals die, we must investigate its impact on why individuals die, and subsequently must identify the mechanisms by which these causes of death are influenced by the physiology associated with reproductive capability. Such an approach may also clarify the effects of reproduction on lifespan in people. PMID:23613790

  10. Impact of Altitude on Power Output during Cycling Stage Racing

    PubMed Central

    Garvican-Lewis, Laura A; Clark, Bradley; Martin, David T.; Schumacher, Yorck Olaf; McDonald, Warren; Stephens, Brian; Ma, Fuhai; Thompson, Kevin G.; Gore, Christopher J.; Menaspà, Paolo

    2015-01-01

    Purpose The purpose of this study was to quantify the effects of moderate-high altitude on power output, cadence, speed and heart rate during a multi-day cycling tour. Methods Power output, heart rate, speed and cadence were collected from elite male road cyclists during maximal efforts of 5, 15, 30, 60, 240 and 600 s. The efforts were completed in a laboratory power-profile assessment, and spontaneously during a cycling race simulation near sea-level and an international cycling race at moderate-high altitude. Matched data from the laboratory power-profile and the highest maximal mean power output (MMP) and corresponding speed and heart rate recorded during the cycling race simulation and cycling race at moderate-high altitude were compared using paired t-tests. Additionally, all MMP and corresponding speeds and heart rates were binned per 1000m (<1000m, 1000–2000, 2000–3000 and >3000m) according to the average altitude of each ride. Mixed linear modelling was used to compare cycling performance data from each altitude bin. Results Power output was similar between the laboratory power-profile and the race simulation, however MMPs for 5–600 s and 15, 60, 240 and 600 s were lower (p ≤ 0.005) during the race at altitude compared with the laboratory power-profile and race simulation, respectively. Furthermore, peak power output and all MMPs were lower (≥ 11.7%, p ≤ 0.001) while racing >3000 m compared with rides completed near sea-level. However, speed associated with MMP 60 and 240 s was greater (p < 0.001) during racing at moderate-high altitude compared with the race simulation near sea-level. Conclusion A reduction in oxygen availability as altitude increases leads to attenuation of cycling power output during competition. Decrement in cycling power output at altitude does not seem to affect speed which tended to be greater at higher altitudes. PMID:26629912

  11. Output tracking of some class non-minimum phase nonlinear systems via output redefinition

    NASA Astrophysics Data System (ADS)

    Firman, Naiborhu, Janson

    2016-02-01

    In this paper, we present the output tracking for a class non-minimum phase nonlinear. To achive the output tracking, we will apply the modified steepest descent control. To apply the modified steepest descent control, the output of the system will be redefined such that the system will become minimum phase with respect to a new output.

  12. High Temperatures Result in Smaller Nurseries which Lower Reproduction of Pollinators and Parasites in a Brood Site Pollination Mutualism

    PubMed Central

    Krishnan, Anusha; Pramanik, Gautam Kumar; Revadi, Santosh V.; Venkateswaran, Vignesh; Borges, Renee M.

    2014-01-01

    In a nursery pollination mutualism, we asked whether environmental factors affected reproduction of mutualistic pollinators, non-mutualistic parasites and seed production via seasonal changes in plant traits such as inflorescence size and within-tree reproductive phenology. We examined seasonal variation in reproduction in Ficus racemosa community members that utilise enclosed inflorescences called syconia as nurseries. Temperature, relative humidity and rainfall defined four seasons: winter; hot days, cold nights; summer and wet seasons. Syconium volumes were highest in winter and lowest in summer, and affected syconium contents positively across all seasons. Greater transpiration from the nurseries was possibly responsible for smaller syconia in summer. The 3–5°C increase in mean temperatures between the cooler seasons and summer reduced fig wasp reproduction and increased seed production nearly two-fold. Yet, seed and pollinator progeny production were never negatively related in any season confirming the mutualistic fig–pollinator association across seasons. Non-pollinator parasites affected seed production negatively in some seasons, but had a surprisingly positive relationship with pollinators in most seasons. While within-tree reproductive phenology did not vary across seasons, its effect on syconium inhabitants varied with season. In all seasons, within-tree reproductive asynchrony affected parasite reproduction negatively, whereas it had a positive effect on pollinator reproduction in winter and a negative effect in summer. Seasonally variable syconium volumes probably caused the differential effect of within-tree reproductive phenology on pollinator reproduction. Within-tree reproductive asynchrony itself was positively affected by intra-tree variation in syconium contents and volume, creating a unique feedback loop which varied across seasons. Therefore, nursery size affected fig wasp reproduction, seed production and within-tree reproductive

  13. Reproductive governance in Latin America.

    PubMed

    Morgan, Lynn M; Roberts, Elizabeth F S

    2012-01-01

    This paper develops the concept of reproductive governance as an analytic tool for tracing the shifting political rationalities of population and reproduction. As advanced here, the concept of reproductive governance refers to the mechanisms through which different historical configurations of actors - such as state, religious, and international financial institutions, NGOs, and social movements - use legislative controls, economic inducements, moral injunctions, direct coercion, and ethical incitements to produce, monitor, and control reproductive behaviours and population practices. Examples are drawn from Latin America, where reproductive governance is undergoing a dramatic transformation as public policy conversations are coalescing around new moral regimes and rights-based actors through debates about abortion, emergency contraception, sterilisation, migration, and assisted reproductive technologies. Reproductive discourses are increasingly framed through morality and contestations over 'rights', where rights-bearing citizens are pitted against each other in claiming reproductive, sexual, indigenous, and natural rights, as well as the 'right to life' of the unborn. The concept of reproductive governance can be applied to other settings in order to understand shifting political rationalities within the domain of reproduction. PMID:22889430

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

    PubMed

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

    2014-09-01

    Despite the well-characterized occurrence of uranium (U) in the aquatic environment, very little is known about the chronic exposure of fish to low levels of U and its potential effect on reproduction. Therefore, this study was undertaken to investigate the effects of environmental concentrations of depleted U on the reproductive output of zebrafish (Danio rerio) and on survival and development of the F1 embryo-larvae following parental exposure to U. For that purpose, sexually mature male and female zebrafish were exposed to 20 and 250 μg/L of U for 14 days and allowed to reproduce in clean water during a further 14-day period. At all sampling times, whole-body vitellogenin concentrations and gonad histology were analyzed to investigate the effects of U exposure on these reproductive endpoints. In addition, accumulation of U in the gonads and its genotoxic effect on male and female gonad cells were quantified. The results showed that U strongly affected the capability of fish to reproduce and to generate viable individuals as evidenced by the inhibition of egg production and the increased rate of mortality of the F1 embryos. Interestingly, U exposure resulted in decreased circulating concentrations of vitellogenin in females. Increased concentrations of U were observed in gonads and eggs, which were most likely responsible for the genotoxic effects seen in fish gonads and in embryos exposed maternally to U. Altogether, these findings highlight the negative effect of environmentally relevant concentrations of U which alter the reproductive capability of fish and impair the genetic integrity of F1 embryos raising further concern regarding its effect at the population level. PMID:24846854

  15. Inflammatory bowel diseases and reproductive health.

    PubMed

    Kokoszko-Bilska, Agnieszka; Sobkiewicz, Slawomir; Fichna, Jakub

    2016-08-01

    Inflammatory bowel diseases (IBD) constitute a group of chronic intestinal diseases, including Crohn's disease and ulcerative colitis, which typically involve patients of reproductive age and may influence several features of human reproduction. There are many concerns regarding the interactions between the course of IBD, applied treatment (pharmacological or surgical), and fertility, reproductive outcomes, and also neonatal outcomes. To review the literature describing fertility in IBD patients (separately for female and male), and possible infertility treatment in this group of patients, a PubMed search for English only publications (articles and/or abstracts) was conducted. Initially, the titles of publications and their abstracts were screened, and the most appropriate articles were selected and reviewed. Overall, in patients with quiescent IBD, fertility is almost identical to the general population, but particular subgroups of patients (with active disease, on pharmacological treatment, and after pelvic or abdominal surgery) may be affected by reduced fertility. Additionally, patients with IBD have fewer children than the general population, mainly as a result of voluntary childlessness. The main objectives for successful reproductive outcomes in IBD patients are proper guidance and also optimal treatment for achieving and maintaining disease remission. Recently, the European Evidence-Based Consensus on Reproduction and Pregnancy in IBD (the European Crohn's and Colitis Organization Guidelines) has been established to optimize preconceptional counseling and to promote an appropriate clinical management for patients planning to conceive. However, further studies are needed regarding the preservation of fertility in IBD patients and introduction of optimal infertility treatment in this group of patients. PMID:27117378

  16. The impact of familial Mediterranean fever on reproductive system.

    PubMed

    Yanmaz, Muyesser Nergiz; Özcan, Ayşet Jane; Savan, Kadir

    2014-01-01

    Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by recurrent attacks of fever, peritonitis, pleuritis, arthritis, or erysipelas-like skin lesion. FMF is the most common periodic febrile syndrome affecting more than 150,000 people worldwide. The majority of patients develop FMF before the age of 20. FMF may cause amyloidosis, which mainly affects the kidneys but may also be accumulated in other organs such as the heart, gastrointestinal tract, and reproductive organs. FMF being a systemic disorder with a risk for amyloidosis, affecting patients in their childbearing years, and with its lifelong colchicine therapy raises concern about its effect on the reproductive system. In this article, we review the impact of FMF and its treatment to the reproductive system of male and female patients, pregnancy, and lactation. PMID:24924605

  17. The song of the old mother: Reproductive senescence in female drosophila

    PubMed Central

    Miller, Paige B; Obrik-Uloho, Oghenemine T; Phan, Mai H; Medrano, Christian L; Renier, Joseph S; Thayer, Joseph L; Wiessner, Gregory; Bloch Qazi, Margaret C

    2014-01-01

    Among animals with multiple reproductive episodes, changes in adult condition over time can have profound effects on lifetime reproductive fitness and offspring performance. The changes in condition associated with senescence can be particularly acute for females who support reproductive processes from oogenesis through fertilization. The pomace fly Drosophila melanogaster is a well-established model system for exploring the physiology of reproduction and senescence. In this review, we describe how increasing maternal age in Drosophila affects reproductive fitness and offspring performance as well as the genetic foundation of these effects. Describing the processes underlying female reproductive senescence helps us understand diverse phenomena including population demographics, condition-dependent selection, sexual conflict, and transgenerational effects of maternal condition on offspring fitness. Understanding the genetic basis of reproductive senescence clarifies the nature of life-history trade-offs as well as potential ways to augment and/or limit female fertility in a variety of organisms. PMID:25523082

  18. Cold-seeking behaviour mitigates reproductive losses from fungal infection in Drosophila.

    PubMed

    Hunt, Vicky L; Zhong, Weihao; McClure, Colin D; Mlynski, David T; Duxbury, Elizabeth M L; Keith Charnley, A; Priest, Nicholas K

    2016-01-01

    Animals must tailor their life-history strategies to suit the prevailing conditions and respond to hazards in the environment. Animals with lethal infections are faced with a difficult choice: to allocate more resources to reproduction and suffer higher mortality or to reduce reproduction with the expectation of enhanced immunity and late-age reproduction. However, the strategies employed to mediate shifts in life-history traits are largely unknown. Here, we investigate the temperature preference of the fruit fly, Drosophila melanogaster, during infection with the fungal pathogen, Metarhizium robertsii, and the consequence of temperature preference on life-history traits. We have measured the temperature preference of fruit flies under different pathogen conditions. We conducted multiple fitness assays of the host and the pathogen under different thermal conditions. From these data, we estimated standard measures of fitness and used age-specific methodologies to test for the fitness trade-offs that are thought to underlie differences in life-history strategy. We found that fungus-infected fruit flies seek out cooler temperatures, which facilitates an adaptive shift in their life-history strategy. The colder temperatures preferred by infected animals were detrimental to the pathogen because it increased resistance to infection. But, it did not provide net benefits that were specific to infected animals, as cooler temperatures increased lifetime reproductive success and survival whether or not the animals were infected. Instead, we find that cold-seeking benefits infected animals by increasing their late-age reproductive output, at a cost to their early-age reproductive output. In contrast, naive control flies prefer warmer temperatures that optimize early-age reproductive, at a cost to reproductive output at late ages. These findings show that infected animals exhibit fundamentally different reproductive strategies than their healthy counterparts. Temperature

  19. Output, Input Enhancement, and the Noticing Hypothesis: An Experimental Study on ESL Relativization.

    ERIC Educational Resources Information Center

    Izumi, Shinichi

    2002-01-01

    Investigates potentially facilitative effects of internal and external attention-drawing devices--output and visual input enhancement--on acquisition of English relativization by adult English-as-a-Second-Language (ESL) learners. Addresses whether producing output promotes noticing of formal elements in target language input and affects subsequent…

  20. A Simple Model for Microchannel Plate Output

    NASA Astrophysics Data System (ADS)

    Harding, E. C.; Weaver, J. L.

    2005-10-01

    Microchannel plates (MCPs) are an essential component in an imaging diagnostic known as an x-ray framing camera, which is currently used by NIF, Omega, Nike, and Z to image radiation imploded targets. An MCP is used to convert incident x-ray photons into electrons with gains of 10^2 to 10^4. These electrons are accelerated into a phosphor and the subsequent visible light is captured with a CCD. A variety of parameters, such as photocathode material type (Au, Ni, CsI), photocathode coating depth, and MCP bias angle, affect the gain and gain variations in the MCP electron output. This poster presents initial results of a simple 3D MCP computer model along with an experimental comparison. Several ideas for increasing MCP imaging performance by reducing gain variations and increasing MCP quantum efficiency are presented. Work supported by the Naval Research Laboratory, National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Research Grant DE-FG52-03NA00064, and through DE FG53 2005 NA26014, and Livermore National Laboratory.

  1. Epigenetics: A key paradigm in reproductive health

    PubMed Central

    Bunkar, Neha; Pathak, Neelam; Lohiya, Nirmal Kumar

    2016-01-01

    It is well established that there is a heritable element of susceptibility to chronic human ailments, yet there is compelling evidence that some components of such heritability are transmitted through non-genetic factors. Due to the complexity of reproductive processes, identifying the inheritance patterns of these factors is not easy. But little doubt exists that besides the genomic backbone, a range of epigenetic cues affect our genetic programme. The inter-generational transmission of epigenetic marks is believed to operate via four principal means that dramatically differ in their information content: DNA methylation, histone modifications, microRNAs and nucleosome positioning. These epigenetic signatures influence the cellular machinery through positive and negative feedback mechanisms either alone or interactively. Understanding how these mechanisms work to activate or deactivate parts of our genetic programme not only on a day-to-day basis but also over generations is an important area of reproductive health research. PMID:27358824

  2. Reproductive technology and the law in Canada.

    PubMed

    Knoppers, B

    1986-06-01

    Even leaving aside the question of the impact of reproductive technology on property law, successions, commercial law and the legal qualification to be given to some of the relationships it entails (e.g. 'deposit' of genetic material, 'lease and hire' of wombs, 'gifts' of embryos), there is no doubt that, like the discovery of the atom, no other scientific advance portends such an enormous potential for human benefits or harm. No other scientific advance will so affect the personal, intimate life of the individual person in its public or private aspects. Beginning then with the positive law (Part I), we will attempt to trace, albeit summarily, possible legal approaches to reproductive technology in Canada and to conclude with an overview of proposed reforms (Part II). PMID:3558768

  3. An introduction to reproduction in pharaonic Egypt.

    PubMed

    Jauniaux, Eric

    2001-01-01

    Reproductive science is a new-born medical speciality compared with other specialities such as surgery or dentistry. However, infertility and obstetrical complications commonly diagnosed in the 20th century have a history as old as medicine itself. In an attempt to distance themselves from the African and Middle-Eastern roots of our culture, the European intellectuals of the 18th and 19th century have written the history of the democratic world starting with the Greco-Roman period. Egyptian medicine has influenced the medicine of neighbouring civilisations, including the culture of ancient Greece and its influence spread onward, thereby affecting Western civilisation. The aim of this review is to give credit to these early researchers, who often concluded with extremely accurate observations and to present their colourful and sometimes controversial contribution to our knowledge of reproductive anatomy, physiology and pathology. PMID:12537807

  4. Potential roles of the prokineticins in reproduction

    PubMed Central

    Maldonado-Pérez, David; Evans, Jemma; Denison, Fiona; Millar, Robert P.; Jabbour, Henry N.

    2007-01-01

    Prokineticins are multifunctional secreted proteins that were originally identified as regulators of intestinal contraction but subsequently shown to affect vascular function, hyperalgesia, spermatogenesis, neuronal survival, circadian rhythm, nociception, feeding behaviour, immune responses, haematopoiesis and the development of the olfactory and gonadotropin-releasing hormone systems. Their role in the reproductive tract is still not fully elucidated, although they are reputed to increase microvascular permeability. Expression of prokineticins and their receptors has been reported in the ovary, uterus, placenta, testis and prostate. Their expression has also been reported in various pathologies of the reproductive tract, and future studies will highlight whether inhibition of prokineticin function in these pathologies would be a useful therapeutic target. PMID:17208447

  5. The impact of reproduction on the stress axis of free-living male northern red backed voles (Myodes rutilus).

    PubMed

    Fletcher, Quinn E; Dantzer, Ben; Boonstra, Rudy

    2015-12-01

    Activation of the hypothalamic-pituitary-adrenal (HPA) axis culminates in the release of glucocorticoids (henceforth CORT), which have wide-reaching physiological effects. Three hypotheses potentially explain seasonal variation in CORT. The enabling hypothesis predicts that reproductive season CORT exceeds post-reproductive season CORT because CORT enables reproductive investment. The inhibitory hypothesis predicts the opposite because CORT can negatively affect reproductive function. The costs of reproduction hypothesis predicts that HPA axis condition declines over and following the reproductive season. We tested these hypotheses in wild male red-backed voles (Myodes rutilus) during the reproductive and post-reproductive seasons. We quantified CORT levels in response to restraint stress tests consisting of three blood samples (initial, stress-induced, and recovery). Mineralocorticoid (MR) and glucocorticoid (GR) receptor mRNA levels in the brain were also quantified over the reproductive season. Total CORT (tCORT) in the initial and stress-induced samples were greater in the post-reproductive than in the reproductive season, which supported the inhibitory hypothesis. Conversely, free CORT (fCORT) did not differ between the reproductive and post-reproductive seasons, which was counter to both the enabling and inhibitory hypotheses. Evidence for HPA axis condition decline in CORT as well as GR and MR mRNA over the reproductive season (i.e. costs of reproduction hypothesis) was mixed. Moreover, all of the parameters that showed signs of declining condition over the reproductive season did not also show signs of declining condition over the post-reproductive season suggesting that the costs resulting from reproductive investment had subsided. In conclusion, our results suggest that different aspects of the HPA axis respond differently to seasonal changes and reproductive investment. PMID:26188715

  6. Cointegration of output, capital, labor, and energy

    NASA Astrophysics Data System (ADS)

    Stresing, R.; Lindenberger, D.; Kã¼mmel, R.

    2008-11-01

    Cointegration analysis is applied to the linear combinations of the time series of (the logarithms of) output, capital, labor, and energy for Germany, Japan, and the USA since 1960. The computed cointegration vectors represent the output elasticities of the aggregate energy-dependent Cobb-Douglas function. The output elasticities give the economic weights of the production factors capital, labor, and energy. We find that they are for labor much smaller and for energy much larger than the cost shares of these factors. In standard economic theory output elasticities equal cost shares. Our heterodox findings support results obtained with LINEX production functions.

  7. Age-specific reproductive success and cost in female Alpine ibex.

    PubMed

    Rughetti, Marco; Dematteis, Andrea; Meneguz, Pier Giuseppe; Festa-Bianchet, Marco

    2015-05-01

    In female mammals, reproduction requires high energy expenditure because of gestation and lactation, possibly leading to a fitness cost. Several studies, however, failed to find the expected negative correlation between current and future reproductive success, likely because of individual heterogeneity in reproductive potential. We compared reproductive performance and costs of reproduction for 40 female Alpine ibex in one established population with 29 females translocated from the same population to a new colony. We investigate factors affecting pregnancy, fecundity and overwinter survival of juveniles, after accounting for individual heterogeneity. In both populations, prime-aged females experienced a strong reproductive cost. Senescent females, however, showed no evidence of reproductive costs. The colonizing population showed lower reproductive cost and better age-specific reproductive performance than the established population. We found a general pattern of low age-specific fecundity and reproductive success that was affected by environmental constraints. Age-specific reproductive success was unrelated to longevity. Although about 84% of adult females appeared to conceive, independently of environmental constraints, energy was allocated to reproduction in a highly conservative manner, leading to low age-specific fecundity (only 36 and 21% of prime-aged and senescent females were seen with a kid) but high kid survival (100% to weaning and 92% to 1 year). Our results suggest that females embarked on lactation only if they had a very high probability of raising their offspring. Our study highlights how reproductive performance and costs in this species vary with age and environment, and are the result of a highly conservative reproductive tactic. PMID:25543851

  8. Reproductive manifestations of thyroid disease.

    PubMed

    Johnson, C A

    1994-05-01

    Thyroid function and reproductive function have many interactions, the scope and mechanism of which are not fully understood. These functions are of greatest clinical importance for veterinarians working with breeders of purebred dogs. Thyroid dysfunction does not always result in clinical signs of reproductive disorders or in subfertility. It seems that animals with overt thyroid dysfunction are those most likely to manifest reproduction problems. PMID:8053110

  9. Post-Disaster Reproductive Health Outcomes

    PubMed Central

    Zotti, Marianne E.; Williams, Amy M.; Robertson, McKaylee; Horney, Jennifer; Hsia, Jason

    2015-01-01

    We examined methodological issues in studies of disaster-related effects on reproductive health outcomes and fertility among women of reproductive age and infants in the United States (US). We conducted a systematic literature review of 1,635 articles and reports published in peer-reviewed journals or by the government from January 1981 through December 2010. We classified the studies using three exposure types: (1) physical exposure to toxicants; (2) psychological trauma; and (3) general exposure to disaster. Fifteen articles met our inclusion criteria concerning research focus and design. Overall studies pertained to eight different disasters, with most (n = 6) focused on the World Trade Center attack. Only one study examined pregnancy loss, i.e., occurrence of spontaneous abortions post-disaster. Most studies focused on associations between disaster and adverse birth outcomes, but two studies pertained only to post-disaster fertility while another two examined it in addition to adverse birth outcomes. In most studies disaster-affected populations were assumed to have experienced psychological trauma, but exposure to trauma was measured in only four studies. Furthermore, effects of both physical exposure to toxicants and psychological trauma on disaster-affected populations were examined in only one study. Effects on birth outcomes were not consistently demonstrated, and study methodologies varied widely. Even so, these studies suggest an association between disasters and reproductive health and highlight the need for further studies to clarify associations. We postulate that post-disaster surveillance among pregnant women could improve our understanding of effects of disaster on the reproductive health of US pregnant women. PMID:22752348

  10. Marijuana, the Endocannabinoid System and the Female Reproductive System

    PubMed Central

    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 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. PMID:27354844

  11. Marijuana, the Endocannabinoid System and the Female Reproductive System.

    PubMed

    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. PMID:27354844

  12. Reproductive health professionals' adoption of emerging technologies for health promotion.

    PubMed

    Smith, Peggy B; Buzi, Ruth S

    2014-12-01

    The purpose of this study was to assess reproductive health professionals' familiarity with and use of various electronic technologies to support health promotion. The study also examined the relationship between demographic characteristics and attitudes and beliefs of the effectiveness of new technologies and perceived barriers for usage. A total of 165 reproductive health professionals at two conferences related to reproductive health in the United States completed the study survey. Personal and organizational factors affected the adoption of electronic technologies for health promotion. This included lack of knowledge, skills, and confidence as well as privacy concerns. The results of the study also suggested that being from an older generation was associated with having lower levels of knowledge, skills, and confidence in using new media. These findings highlight the importance of creating learning opportunities on the use of new technology for health promotion as well as addressing specific perceived barriers among reproductive health professionals in order to promote the adoption of these technologies. PMID:25411221

  13. Selective advantage for sexual reproduction

    NASA Astrophysics Data System (ADS)

    Tannenbaum, Emmanuel

    2006-06-01

    This paper develops a simplified model for sexual reproduction within the quasispecies formalism. The model assumes a diploid genome consisting of two chromosomes, where the fitness is determined by the number of chromosomes that are identical to a given master sequence. We also assume that there is a cost to sexual reproduction, given by a characteristic time τseek during which haploid cells seek out a mate with which to recombine. If the mating strategy is such that only viable haploids can mate, then when τseek=0 , it is possible to show that sexual reproduction will always out compete asexual reproduction. However, as τseek increases, sexual reproduction only becomes advantageous at progressively higher mutation rates. Once the time cost for sex reaches a critical threshold, the selective advantage for sexual reproduction disappears entirely. The results of this paper suggest that sexual reproduction is not advantageous in small populations per se, but rather in populations with low replication rates. In this regime, the cost for sex is sufficiently low that the selective advantage obtained through recombination leads to the dominance of the strategy. In fact, at a given replication rate and for a fixed environment volume, sexual reproduction is selected for in high populations because of the reduced time spent finding a reproductive partner.

  14. Environmental release of chemicals and reproductive ecology.

    PubMed

    Bajaj, J S; Misra, A; Rajalakshmi, M; Madan, R

    1993-07-01

    Reproductive ecology is defined as "the study of causes and mechanisms of the effects of environmental risk factors on reproductive health and the methods of their prevention and management." Major areas of concern, within the purview of this paper, relate to adverse pregnancy outcomes, effects on target tissues in the male and the female, and alterations in the control and regulatory mechanisms of reproductive processes. Teratogenic potential of chemicals, released as a result of accidents and catastrophes, is of critical significance. Congenital Minamata disease is due to transplacental fetal toxicity caused by accidental ingestion of methyl mercury. Generalized disorders of ectodermal tissue following prenatal exposure to polychlorinated biphenyls have been reported in Taiwan and Japan. The Bhopal gas disaster, a catastrophic industrial accident, was due to a leak of toxic gas, methyl isocyanate (MIC), in the pesticide manufacturing process. The outcome of pregnancy was studied in female survivors of MIC exposure. The spontaneous abortion rate was nearly four times more common in the affected areas as compared to the control area (24.2% versus 5.6%; p < 0.0001). Furthermore, while stillbirth rate was found to be similar in the affected and control areas, the perinatal and neonatal mortality rates were observed to be higher in the affected area. The rate of congenital malformations in the affected and control areas did not show any significant difference. Chromosomal aberrations and sister chromatid exchange (SCE) frequencies were investigated in human survivors of exposure. The observed SCE frequencies in control and exposed groups indicated that mutagenesis has been induced. Strategies for the management, prediction, and preventability of such disasters are outlined. PMID:8243381

  15. Reproduction of the Solenopsis Mealybug, Phenacoccus Solenopsis: Males Play an Important Role

    PubMed Central

    Huang, Fang; Zhang, Jing-Ming; Zhang, Peng-Jun; Lu, Yao-Bin

    2013-01-01

    The solenopsis mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), is an aggressive pest threatening crops worldwide. The biology of P. solenopsis has been described in several studies, but detailed information on the reproduction of P. solenopsis has not been investigated. The results of our study showed: 1) no progeny could be produced by virgins; 2) apoptosis of follicle cells, which occurs when the eggs begin to develop, did not happen in virgins; and 3) oosorption occurred in the unfertilized eggs. This suggests that P. solenopsis is an obligate amphimictic species, and resorption of developed eggs fits the “wait to reproduce” oosorption hypothesis. Compared to females that mated when they were two days old, the females that mated 30 days after eclosion had lower reproductive output and longer adult lifespans, but had higher reproductive output and shorter lifespan than those of the unmated females. Such a phenomenon suggests that resources obtained from eggs can be allocated for survival until conditions for reproduction improve. The results of this study provide evidence for a trade-off between survival and future reproduction: delayed reproductive conditions trigger physiological states geared toward survival at the expense of reproduction. The mating history of the males had no effect on progeny production. PMID:24766493

  16. Reproductive success of kittiwakes and murres in sequential stages of the nesting period: Relationships with diet and oceanography

    NASA Astrophysics Data System (ADS)

    Renner, Heather M.; Drummond, Brie A.; Benson, Anna-Marie; Paredes, Rosana

    2014-11-01

    Reproductive success is one of the most easily-measured and widely studied demographic parameters of colonial nesting seabirds. Nevertheless, factors affecting the sequential stages (egg laying, incubation, chick-rearing) of reproductive success are less understood. We investigated the separate sequential stages of reproductive success in piscivorous black-legged kittiwakes (Rissa tridactyla) and thick-billed murres (Uria lomvia) using a 36-year dataset (1975-2010) on the major Pribilof Islands (St. Paul and St. George), which have recently had contrasting population trajectories. Our objectives were to evaluate how the proportion of successful nests varied among stages, and to quantify factors influencing the probability of nest success at each stage in each island. We modeled the probability of nest success at each stage using General Linear Mixed Models incorporating broad-scale and local climate variables, and diet as covariates as well as other measures of reproduction such as timing of breeding and reproductive output in the previous year and previous stage. For both species we found: (1) Success in previous stages of the breeding cycle and success in the prior year better explained overall success than any environmental variables. Phenology was also an important predictor of laying success for kittiwakes. (2) Fledging success was lower when chick diets contained oceanic fish found farther from the colonies and small invertebrates, rather than coastal fish species. (3) Differences in reproductive variables at St. Paul and St. George islands did not correspond to population trends between the two islands. Our results highlight the potential importance of adult condition and annual survival to kittiwake and murre productivity and ultimately, populations. Adult condition carrying over from the previous year ultimately seems to drive annual breeding success in a cascade effect. Furthermore, condition and survival appear to be important contributors to population

  17. Reproduction and advances in reproductive studies in carnivores.

    PubMed

    Jewgenow, Katarina; Songsasen, Nucharin

    2014-01-01

    Reproductive mechanisms are extraordinarily diverse among species, even within the same phylogenetic clade. Due to this, it has been difficult to directly apply reproductive technologies developed in human and livestock to genetically manage ex situ wildlife, including carnivores. To date, more common, closely related species, e.g., domestic cats, dogs and ferrets have served as valuable models for developing reproductive technologies for managing rare, endangered carnivores. Artificial insemination and sperm cryopreservation have already been successfully used to manage ex situ populations in some carnivore species, such as the black-footed ferret, cheetah and giant panda. However, technologies aiming at preserving genetics of valuable females have not been fully developed in carnivores, due to the lack of fundamental knowledge about reproductive anatomy and physiology, gamete development, embryogenesis and cryopreservation. The present chapter is divided into two parts. The first part focuses on current knowledge about carnivore reproduction, with emphasis on species diversity in reproductive mechanisms. The second part highlights the progress in reproductive science and related technologies made during the last decade. In addition, we provide examples of how reproductive technologies can contribute to carnivore management and conservation. Although carnivores are comprised of 19 families, we will only focus our attention on four taxonomic groups, including felids, canids, ursids and mustelids. PMID:25091912

  18. Smoking and reproduction.

    PubMed

    Lincoln, R

    1986-01-01

    2 of the 5 health warnings that must now appear on American cigarette packs and cigarette advertising refer to some of the increased hazards smoking entails for the woman and her unborn child. Yet, the myriad reproductive risks associated with smoking are little known or considered by the general public--or even by physicians--when compared with the dangers of lung cancer, heart attacks and emphysema. In an attempt to remedy that deficit, 8 government agencies sponsored the 1st International Conference on Smoking and Reproductive Health, held October 15-17, 1985 in San Francisco. Speaker after expert speaker connected smoking during pregnancy with increased risks of low birth weight, miscarriage, infant mortality and morbidity--including poorer health of surviving children up to at least age 3--ectopic pregnancy, infertility, menstrual disorders, early menopause, osteoporosis, cervical cancer and dysplasia, cardiovascular disease and placental abnormalities. Similarly, the conference participants documented the association of smoking among men with lower sperm count and increased prevalence of abnormal sperm. The following measures were urged at the closing statements of the conference: 1) an increased effort to inform doctors and health professionals of these findings; 2) increasing the tax on cigarettes, so that smokers would pay for their own health costs; 3) decreasing or eliminating government subsidies for growing tobacco, while helping growers make the transition to nontobacco crops; 4) making smoking cessation programs more widely available; 5) prohibiting the sale of cigarettes through vending machines; and 6) banning all smoking in the workplace. PMID:3539634

  19. Effects of the organophosphate paraoxon-methyl on survival and reproduction of Daphnia magna: importance of exposure duration and recovery.

    PubMed

    Duquesne, Sabine; Reynaldi, Sebastián; Liess, Matthias

    2006-05-01

    The aim of this study was to determine the influence of exposure duration (1 h, 24 h, continuous) to paraoxon-methyl on the magnitude of lethal and sublethal effects, the shape of the concentration-response relationships and the recovery processes in Daphnia magna. Survival was more severely reduced in the continuous than in the pulse exposure regimes. The lethal concentrations (3d median lethal concentration [LC50] values) were 233, 2.33, and 1.14 microg/L after 1-h, 24-h, and continuous exposure, respectively. The shapes of the concentration-response relationships for survival were significantly different after 1 h of exposure than after 24-h and continuous exposure. Indeed, the slopes of the curves defined by the ratios LC90/LC10 (ratio of 90 and 10% lethal concentrations) were 100, 1.74, and 1.97 for 1-h, 24-h, and continuous exposure, respectively. The large difference between 1 h and longer durations of exposure shows that the population is partially affected (10-90%) over a much broader range of concentrations when exposure is short. Negative effects on reproductive outputs occurred mostly at concentrations affecting partly the survival and therefore also over a broad range of concentrations after 1 h of exposure. However, these effects were only transient in the pulse exposure regimes as individual performances recovered. By contrast, reproductive outputs of survivors exposed continuously remained impaired. These results suggest that a refined risk assessment should consider exposure duration because it influences the magnitude of effects and recovery. PMID:16704048

  20. Reproduction alters oxidative status when it is traded-off against longevity.

    PubMed

    Beaulieu, Michaël; Geiger, Rina E; Reim, Elisabeth; Zielke, Luisa; Fischer, Klaus

    2015-07-01

    Oxidative stress has been proposed to mediate one of the most important aspects of life-history evolution: the trade-off between reproduction and self-maintenance. However, empirical studies have cast doubt on the generality of this intriguing notion. Here, we hypothesize that reproduction alters oxidative status only when a trade-off between reproduction and self-maintenance occurs. Accordingly, in female Bicyclus anynana butterflies, we found that reproduction affected oxidative markers only under challenging thermal conditions that made the trade-off between reproduction and longevity emerge. Interestingly, under such conditions, butterflies favored longevity over reproduction, suggesting that self-maintenance mechanisms were activated. Accordingly, butterflies reproducing under challenging thermal conditions exhibited enhanced antioxidant defenses and stable oxidative damage. Altogether, our results indicate that a trade-off between reproduction and self-maintenance is indeed a necessary condition for reproduction to alter oxidative status, and that the effects of such a trade-off on oxidative status depend on whether priority is given to self-maintenance or reproduction. Assessing the existence of the trade-off between self-maintenance and reproduction, and whether self-maintenance is prioritized relative to reproduction is therefore crucial for understanding variation in oxidative status in reproducing animals, which may clarify the general implication of oxidative stress in the resolution of life-history trade-offs. PMID:26095834

  1. Impact of stress on oocyte quality and reproductive outcome.

    PubMed

    Prasad, Shilpa; Tiwari, Meenakshi; Pandey, Ashutosh N; Shrivastav, Tulsidas G; Chaube, Shail K

    2016-01-01

    Stress is an important factor that affects physical and mental status of a healthy person disturbing homeostasis of the body. Changes in the lifestyle are one of the major causes that lead to psychological stress. Psychological stress could impact the biology of female reproduction by targeting at the level of ovary, follicle and oocyte. The increased level of stress hormone such as cortisol reduces estradiol production possibly by affecting the granulosa cell functions within the follicle, which results deterioration in oocyte quality. Adaptation of lifestyle behaviours may generate reactive oxygen species (ROS) in the ovary, which further affects female reproduction. Balance between level of ROS and antioxidants within the ovary are important for maintenance of female reproductive health. Physiological level of ROS modulates oocyte functions, while its accumulation leads to oxidative stress (OS). OS triggers apoptosis in majority of germ cells within the ovary and even in ovulated oocytes. Although both mitochondria- as well as death-receptor pathways are involved in oocyte apoptosis, OS-induced mitochondria-mediated pathway plays a major role in the elimination of majority of germ cells from ovary. OS in the follicular fluid deteriorates oocyte quality and reduces reproductive outcome. On the other hand, antioxidants reduce ROS levels and protect against OS-mediated germ cell apoptosis and thereby depletion of germ cells from the ovary. Indeed, OS is one of the major factors that has a direct negative impact on oocyte quality and limits female reproductive outcome in several mammalian species including human. PMID:27026099

  2. High Power Amplifier Harmonic Output Level Measurement

    NASA Technical Reports Server (NTRS)

    Perez, R. M.; Hoppe, D. J.; Khan, A. R.

    1995-01-01

    A method is presented for the measurement of the harmonic output power of high power klystron amplifiers, involving coherent hemispherical radiation pattern measurements of the radiated klystron output. Results are discussed for the operation in saturated and unsaturated conditions, and with a waveguide harmonic filter included.

  3. Computer Output Microfilm and Library Catalogs.

    ERIC Educational Resources Information Center

    Meyer, Richard W.

    Early computers dealt with mathematical and scientific problems requiring very little input and not much output, therefore high speed printing devices were not required. Today with increased variety of use, high speed printing is necessary and Computer Output Microfilm (COM) devices have been created to meet this need. This indirect process can…

  4. Reinvestigating the Noticing Function of Output

    ERIC Educational Resources Information Center

    Uggen, Maren S.

    2012-01-01

    A conceptual replication of Izumi and Bigelow's research, this study used multiple measures to investigate second language (L2) learners' processes in output-input-output sequences. Specifically, it examined whether producing the target language impacts learners' attention to L2 structures in subsequent input. Thirty learners of English as a…

  5. Output beam analysis of high power COIL

    NASA Astrophysics Data System (ADS)

    Yu, Deli; Sang, Fengting; Jin, Yuqi; Sun, Yizhu

    2003-03-01

    As the output power of a chemical oxygen iodine laser (COIL) increases, the output laser beam instability appears as the far-field beam spot drift and deformation for the large Fresnel number unstable resonator. In order to interpret this phenomenon, an output beam mode simulation code was developed with the fast Fourier transform method. The calculation results show that the presence of the nonuniform gain in COIL produces a skewed output intensity distribution, which causes the mirror tilt and bulge due to the thermal expansion. With the output power of COIL increases, the mirror surfaces, especially the back surface of the scraper mirror, absorb more and more heat, which causes the drift and deformation of far field beam spot seriously. The initial misalignment direction is an important factor for the far field beam spot drifting and deformation.

  6. Consequences for conservation: population density and genetic effects on reproduction of an endangered lagomorph.

    PubMed

    Demay, Stephanie M; Becker, Penny A; Waits, Lisette P; Johnson, Timothy R; Rachlow, Janet L

    2016-04-01

    Understanding reproduction and mating systems is important for managers tasked with conserving vulnerable species. Genetic tools allow biologists to investigate reproduction and mating systems with high resolution and are particularly useful for species that are otherwise difficult to study in their natural environments. We conducted parentage analyses using 19 nuclear DNA microsatellite loci to assess the influence of population density, genetic diversity, and ancestry on reproduction, and to examine the mating system of pygmy rabbits (Brachylagus idahoensis) bred in large naturalized enclosures for the reintroduction and recovery of the endangered distinct population in central Washington, USA. Reproductive output for females and males decreased as population density and individual homozygosity increased. We identified an interaction indicating that male reproductive output decreased as genetic diversity declined at high population densities, but there was no effect at low densities. Males with high amounts (> 50%) of Washington ancestry had higher reproductive output than the other ancestry groups, while reproductive output was decreased for males with high northern Utah/Wyoming ancestry and females with high Oregon/Nevada ancestry. Females and males bred with an average of 3.8 and 3.6 mates per year, respectively, and we found no evidence of positive or negative assortative mating with regards to ancestry. Multiple paternity was confirmed in 81% of litters, and we report the first documented cases of juvenile breeding by pygmy rabbits. This study demonstrates how variation in population density, genetic diversity, and ancestry impact fitness for an endangered species being bred for conservation. Our results advance understanding of basic life history characteristics for a cryptic species that is difficult to study in the wild and provide lessons for managing populations of vulnerable species in captive and free-ranging populations. PMID:27411250

  7. Snow conditions as an estimator of the breeding output in high-Arctic pink-footed geese Anser brachyrhynchus

    USGS Publications Warehouse

    Jensen, Gitte Høj; Madsen, Jesper; Johnson, Fred A.; Tamstorf, Mikkel P.

    2014-01-01

    The Svalbard-breeding population of pink-footed geese Anser brachyrhynchus has increased during the last decades and is giving rise to agricultural conflicts along their migration route, as well as causing grazing impacts on tundra vegetation. An adaptive flyway management plan has been implemented, which will be based on predictive population models including environmental variables expected to affect goose population development, such as weather conditions on the breeding grounds. A local study in Svalbard showed that snow cover prior to egg laying is a crucial factor for the reproductive output of pink-footed geese, and MODIS satellite images provided a useful estimator of snow cover. In this study, we up-scaled the analysis to the population level by examining various measures of snow conditions and compared them with the overall breeding success of the population as indexed by the proportion of juveniles in the autumn population. As explanatory variables, we explored MODIS images, satellite-based radar measures of onset of snow melt, winter NAO index, and the May temperature sum and May thaw days. To test for the presence of density dependence, we included the number of adults in the population. For 2000–2011, MODIS-derived snow cover (available since 2000) was the strongest indicator of breeding conditions. For 1981–2011, winter NAO and May thaw days had equal weight. Interestingly, there appears to have been a phase shift from density-dependent to density-independent reproduction, which is consistent with a hypothesis of released breeding potential due to the recent advancement of spring in Svalbard.

  8. Flower diversity and bee reproduction in an arid ecosystem

    PubMed Central

    Vázquez, Diego P.

    2016-01-01

    Background: Diverse flower communities are more stable in floral resource production along the flowering season, but the question about how the diversity and stability of resources affect pollinator reproduction remains open. High plant diversity could favor short foraging trips, which in turn would enhance bee fitness. In addition to plant diversity, greater temporal stability of floral resources in diverse communities could favor pollinator fitness because such communities are likely to occupy the phenological space more broadly, increasing floral availability for pollinators throughout the season. In addition, this potential effect of flower diversity on bee reproduction could be stronger for generalist pollinators because they can use a broader floral spectrum. Based on above arguments we predicted that pollinator reproduction would be positively correlated to flower diversity, and to temporal stability in flower production, and that this relationship would be stronger for the most generalized pollinator species. Materials and Methods: Using structural equation models, we evaluated the effect of these variables and other ecological factors on three estimates of bee reproduction (average number of brood cells per nest per site, total number of brood cells per site, and total number of nests per site), and whether such effects were modulated by bee generalization on floral resources. Results: Contrary to our expectations, flower diversity had no effect on bee reproduction, stability in flower production had a weakly negative effect on one of the bee reproductive variables, and the strength of the fitness-diversity relationship was unrelated to bee generalization. In contrast, elevation had a negative effect on bee reproduction, despite the narrow elevation range encompassed by our sites. Discussion: Flower diversity did not affect the reproduction of the solitary bees studied here. This result could stem from the context dependence of the diversity

  9. Quantitative genomics of female reproduction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous quantitative trait loci (QTL) for reproductive traits in domestic livestock have been described in the literature. In this chapter, the components needed for detection of reproductive trait QTL are described, including collection of phenotypes, genotypes, and the appropriate statistical ana...

  10. Phthalates as developmental reproductive toxicants

    EPA Science Inventory

    PE are a large family ofcompounds used in a wide array ofconsumer, industrial and medical products. Studies have shown that in utero treatment with PE such as diethyl hexyl phthalate (DEHP) during the critical period offetal reproductive development produced male reproductive mal...

  11. Quantitative Genomics of Male Reproduction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of the review was to establish the current status of quantitative genomics for male reproduction. Genetic variation exists for male reproduction traits. These traits are expensive and time consuming traits to evaluate through conventional breeding schemes. Genomics is an alternative to...

  12. Pollinator limitation and the effect of breeding systems on plant reproduction in forest fragments

    NASA Astrophysics Data System (ADS)

    Nayak, K. Geetha; Davidar, Priya

    2010-03-01

    Reproduction of plants in fragmented habitats may be limited because of lower diversity or abundance of pollinators, and/or variation in local plant density. We assessed natural fruit set and pollinator limitation in ten species of woody plants in natural and restored fragments in the Pondicherry region of southern India, to see whether breeding system of plants (self-compatible and self-incompatible) affected fruit set. We tested whether the number of flowering individuals in the fragments affected the fruit set and further examined the adult and sapling densities of self-compatible (SC) and self-incompatible (SI) species. We measured the natural level of fruit set and pollinator limitation (calculated as the difference in fruit set between hand cross-pollinated and naturally pollinated flowers). Our results demonstrate that there was a higher level of pollinator limitation and hence lower levels of natural fruit set in self-incompatible species as compared to self-compatible species. However, the hand cross-pollinated flowers in SC and SI species produced similar levels of fruit set, further indicating that lower fruit set was due to pollinator limitation and not due to lack of cross-compatible individuals in the fragments. There was no significant relation between number of flowering individuals and the levels of natural fruit set, except for two species Derris ovalifolia, Ixora pavetta. In these species the natural fruit set decreased with increasing population size, again indicating pollinator limitation. The adult and sapling densities in self-compatible species were significantly higher than in self-incompatible species. These findings indicate that the low reproductive output in self-incompatible species may eventually lead to lower population sizes. Restoration of pollinator services along with plant species in fragmented habitats is important for the long-term conservation of biodiversity.

  13. Pulsatile control of reproduction.

    PubMed

    1984-08-18

    An aspect of the neuroendocrine regulation of reproduction to emerge in the past decade is the pulsatile nature of hormone secretion. The pulse generator is in the central nervous system -- in the medial basal region of the hypothalamus. It works by a synchronous firing of entire populations of endocrine neurons, which discharge a quantum of the decapeptide gonadotropin-releasing hormone (GnRH) into the portal blood capillaries which then carry it to the anterior pituitary gland. In man, episodic secretion of pituitary gonadotropins, especially luteinizing hormone (LH) is considered to imply a preceding pulsatile GnRH stimulus also, though this cannot be observed directly. This LH pattern is characterized by discrete bursts (pulses) separated by periods of little or no secretion. It is observalbe at all stages and states of reproductive life, being most evident at high secretion rates (e.g., at midcycle and after menopause). The pulse frequency is important and leads to the possibility of physiological and pharmacological control of pituitary-gonadal function by frequency modulation. Physiologically, pulses of LH secretion occur every 1-2 hours. The need for pulsatility in therapeutic GnRH stimulation of the pituitary also has been established following the early days of GnRH therapy when both constant and infrequent administration were found to be ineffective. Pulsatile GnRH therapy through portable pumps delivering small doses subcutaneously or intravenously every 1-2 hours has now been successfully applied to the treatment of anovulatory infertility, male hypogonadism, and the initiation of puberty. Supraphysiological GnRH stimulation, whether through increased frequency or amplitude or use of the "superactive" agonist analogues, produces a seemingly paradoxical inhibition of gonadotropin secretion. Although a postreceptor effect has been proposed, the mechanism appears to be a "down-regulation" of the GnRH receptors. Normally, the gaps between the physiological

  14. Differential reproductive strategies of two bivalves in the Dutch Wadden Sea

    NASA Astrophysics Data System (ADS)

    Cardoso, Joana F. M. F.; Witte, Johannes IJ.; van der Veer, Henk W.

    2009-08-01

    Cerastoderma edule and Mya arenaria are two common bivalve species in European waters. Longevity and maximum size are much greater in the latter species. Because comparison of species life-history strategies states that a long life span (i.e. high annual survival) generally goes with lower fecundity, we hypothesise that reproductive output would be lower in M. arenaria than in C. edule. In the present paper, we studied the reproductive strategies of these two species in an intertidal and a subtidal area of the western Dutch Wadden Sea, by following seasonal changes in absolute and relative weights of somatic and gonadal tissues in these bivalves. Starting of spawning was similar in the two species, around May, except for intertidal M. arenaria, which initiated spawning in August. Individual energy investment in reproduction was similar for the two species but, unlike M. arenaria, C. edule spawned completely, releasing all energy of gonadal mass in the form of gametes. Mya arenaria used the gonad not only for reproduction but also for storage. In the intertidal area, we found a trade-off between longevity and reproduction, i.e. maximum reproductive output (expressed as a proportion of body mass) was higher in C. edule than in M. arenaria. However, since body size is larger and life span longer in M. arenaria than in C. edule, mean lifetime reproductive output per individual must be higher in the first than in the latter. Based on the differences in reproductive strategies of these two species, we hypothesise that the negative effects of warming climate on bivalve population dynamics in the Wadden Sea will be stronger in C. edule than in M. arenaria.

  15. Molecular effects of nicarbazin on avian reproduction.

    PubMed

    Yoder, C A; Graham, J K; Miller, L A

    2006-07-01

    Nicarbazin (NCZ) is an anticoccidial drug routinely used in the poultry industry that can negatively affect reproduction by reducing egg production, egg weight, and egg hatchability. The molecular mechanisms by which NCZ affects reproduction are unknown. Lipoprotein lipase, vitellogenin, transglutaminase, and calcium are all involved in egg formation and embryogenesis. Therefore, in vitro assays were used to evaluate 4 potential mechanisms of action of NCZ on egg formation and embryogenesis. First, a lipoprotein lipase assay was conducted to determine if NCZ increases lipoprotein lipase activity. Second, vitellogenin phosphorylation was evaluated to determine if NCZ acts as a vitellogenin phosphatase. Third, transglutaminase activity was measured to determine if NCZ inhibits transglutaminase activity. Finally, bull sperm was used as a model to determine if specific channel-mediated calcium uptake can be blocked by NCZ. Nicarbazin increased the activity of lipoprotein lipase in vitro at 3.9 and 7.8 microg of NCZ/mL. Nicarbazin increased intracellular calcium levels in bull sperm, suggesting it also acts as a calcium ionophore. The portion of the NCZ molecule responsible for the increase in intracellular calcium is 2-hydroxy-4,6-dimethylpyrimidine. Nicarbazin affected vitellogenin phosphorylation but only at a concentration many times higher than expected plasma values. Nicarbazin also inhibited transglutaminase activity in vitro. Whereas the 4,4'-dinitrocarbanilide portion of the NCZ molecule inhibited transglutaminase activity, the 2-hydroxy-4,6-dimethylpyrimidine portion increased transglutaminase activity. All of these assays were conducted in vitro; therefore these results should be viewed as preliminary findings to aid in directing further research on the effect of NCZ on reproduction in vivo. Because NCZ increases lipoprotein lipase activity and acts as a calcium ionophore, future experiments should investigate these effects in particular. PMID:16830870

  16. Mechanical Signaling in Reproductive Tissues

    PubMed Central

    Jorge, Soledad; Chang, Sydney; Barzilai, Joshua J.; Leppert, Phyllis

    2014-01-01

    The organs of the female reproductive system are among the most dynamic tissues in the human body, undergoing repeated cycles of growth and involution from puberty through menopause. To achieve such impressive plasticity, reproductive tissues must respond not only to soluble signals (hormones, growth factors, and cytokines) but also to physical cues (mechanical forces and osmotic stress) as well. Here, we review the mechanisms underlying the process of mechanotransduction—how signals are conveyed from the extracellular matrix that surrounds the cells of reproductive tissues to the downstream molecules and signaling pathways that coordinate the cellular adaptive response to external forces. Our objective was to examine how mechanical forces contribute significantly to physiological functions and pathogenesis in reproductive tissues. We highlight how widespread diseases of the reproductive tract, from preterm labor to tumors of the uterus and breast, result from an impairment in mechanical signaling. PMID:25001021

  17. Male reproductive health and yoga

    PubMed Central

    Sengupta, Pallav; Chaudhuri, Prasenjit; Bhattacharya, Koushik

    2013-01-01

    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. PMID:23930026

  18. EFFECTS OF THE DURATION AND TIMING OF DIETARY METHYL PARATHION EXPOSURE ON BOBWHITE REPRODUCTION

    EPA Science Inventory

    Two northern bobwhite (colinus virginianus) reproduction tests were conducted concurrently to evaluate how the duration and time of initiation of methyl parathion exposure affeCted dose-response relationships of reproductive parameters. n the long-term exposure test, pairs of adu...

  19. DELAYED REPRODUCTIVE EFFECTS FOLLOWING EXPOSURE TO TOXIC CHEMICALS DURING CRITICAL DEVELOPMENTAL PERIODS

    EPA Science Inventory

    The studies presented in this review indicate that perinatal exposure of the fetal or neonatal rodent to a toxicant can adversely affect reproductive development, reduce fertility.and accelerate reproductive senescence. n rodents and humans exposure to DES, estrogens, androgens a...

  20. Reproductive Health Education Model in Early Childhood through Education Film "Damar Wulan"

    ERIC Educational Resources Information Center

    Zahrulianingdyah, Atiek

    2015-01-01

    Reproductive health education for early childhood it has been the time to teach, because the demand of the changing times and will affect the child's life when he/she is a teenager. During this time, the reproductive health education, which is in it there is sex education, considered taboo among some communities. They argue that the reproductive…

  1. A review of reproductive toxicity of microcystins.

    PubMed

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

    2016-01-15

    Animal studies provide strong evidence of positive associations between microcystins (MCs) exposure and reproductive toxicity, representing a threat to human reproductive health and the biodiversity of wild life. This paper reviews current knowledge of the reproductive toxicity of MCs, with regard to mammals, fishes, amphibians, and birds, mostly in males. Toxicity of MCs is primarily governed by the inhibition of protein phosphatases 1 and 2A (PP1 and PP2A) and disturbance of cellular phosphorylation balance. MCs exposure is related to excessive production of reactive oxygen species (ROS) and oxidative stress, leading to cytoskeleton disruption, mitochondria dysfunction, endoplasmic reticulum (ER) stress, and DNA damage. MCs induce cell apoptosis mediated by the mitochondrial and ROS and ER pathways. Through PP1/2A inhibition and oxidative stress, MCs lead to differential expression/activity of transcriptional factors and proteins involved in the pathways of cellular differentiation, proliferation, and tumor promotion. MC-induced DNA damage is also involved in carcinogenicity. Apart from a direct effect on testes and ovaries, MCs indirectly affect sex hormones by damaging the hypothalamic-pituitary-gonad (HPG) axis and liver. Parental exposure to MCs may result in hepatotoxicity and neurotoxicity of offspring. We also summarize the current research gaps which should be addressed by further studies. PMID:26521084

  2. Effect of stevioside on growth and reproduction.

    PubMed

    Yodyingyuad, V; Bunyawong, S

    1991-01-01

    The effect on growth and reproduction in hamsters of stevioside, which is extracted from stevia leaves (Stevia rebaudiana Bertoni) and is currently used as a non-caloric sweetener, was investigated. Four groups of 20 one-month-old hamsters (10 males and 10 females) were daily force-fed with stevioside (0.0, 0.5, 1.0 and 2.5 g/kg body wt/day, respectively). No abnormalities were found in growth and fertility in both sexes. All males mated females efficiently and successfully. Females showed normal 4-day oestrus cycles and became pregnant after mating. Each female was mated and allowed to bear three litters during the period of experiment. The duration of pregnancy, number of fetuses, as well as number of young delivered each time from females in the experimental groups were not significantly different from those in the control group. The young F1 and F2 hamsters continuously receiving stevioside via drinking water until one month old and daily force-fed afterwards at the same doses as their parents showed normal growth and fertility. Histological examinations of