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Sample records for repeated reproductive cycles

  1. Experimental study on the long-term effect of cadmium in mice fed cadmium-polluted rice with special reference to the effect of repeated reproductive cycles

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    Watanabe, M.; Shiroishi, K.; Nishino, H.; Shinmura, T.; Murase, H.; Shoji, T.; Naruse, Y.; Kagamimori, S.

    1986-06-01

    Long-term biological effects of cadmium-polluted rice and effect of repeated reproductive cycles on them were examined. Female SLC-B6D2F mice (female C57BL/6, male DBA/2) were fed a rice diet containing 65% unpolished rice for about 2 years from 7 weeks of age. The unpolished rice preparations used were commercially available rice (non-Cd-polluted) and Cd-polluted rice (over 1.0 ppm). Average Cd contents in each diet class were 0.12, 0.48, 1.78, 1.75, and 47.1 ppm (50 ppm Cd as CdCl/sub 2/ added). Some experimental mice were subjected to repeated reproductive cycles (parity group). Hematological, biochemical, and pathological examinations of urine, blood, and tissues, including Cd measurement, were carried out. Results after statistical analysis indicate Cd toxicities such as anemia and disturbances of Ca metabolism. These Cd effects were found to be enhanced by the reproductive cycles. Soft X-ray radiograms showed osteoporosis in the parity groups, especially in the groups with diets of higher Cd content. However, we could not find any sign of disturbance of renal function under our experimental conditions.

  2. Reproductive cycle of goats.

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    Fatet, Alice; Pellicer-Rubio, Maria-Teresa; Leboeuf, Bernard

    2011-04-01

    Goats are spontaneously ovulating, polyoestrous animals. Oestrous cycles in goats are reviewed in this paper with a view to clarifying interactions between cyclical changes in tissues, hormones and behaviour. Reproduction in goats is described as seasonal; the onset and length of the breeding season is dependent on various factors such as latitude, climate, breed, physiological stage, presence of the male, breeding system and specifically photoperiod. In temperate regions, reproduction in goats is described as seasonal with breeding period in the fall and winter and important differences in seasonality between breeds and locations. In tropical regions, goats are considered continuous breeders; however, restricted food availability often causes prolonged anoestrous and anovulatory periods and reduced fertility and prolificacy. Different strategies of breeding management have been developed to meet the supply needs and expectations of consumers, since both meat and milk industries are subjected to growing demands for year-round production. Hormonal treatments, to synchronize oestrus and ovulation in combination with artificial insemination (AI) or natural mating, allow out-of-season breeding and the grouping of the kidding period. Photoperiodic treatments coupled with buck effect now allow hormone-free synchronization of ovulation but fertility results after AI are still behind those of hormonal treatments. The latter techniques are still under study and will help meeting the emerging social demand of reducing the use of hormones for the management of breeding systems.

  3. Synchronisation of the reproductive cycle in pigs

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    Hazeleger, W.; Kirkwood, R.N.; Soede, N.M.

    2001-01-01

    An outline of procedures to synchronise oestrus and ovulation in pigs is described. The oestrus cycle of pigs can be synchronised depending on the stage of the reproductive cycle of these animals. Non-cyclic gilts shortly before puberty, can easily be synchronised by treatments with a mixture of 400

  4. PRODUCTIVITY, REPEATABILITY OF PRODUCTIVE AND REPRODUCTIVE TRAITS OF LOCAL PIGEON

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    S. Darwati

    2014-10-01

    Full Text Available The purpose of this study was to know productivity and repeatability of local pigeon. Data werecollected from 124 birds that reared under intensive management. The results showed that artificial pairwas 100% and polygamy was 16% (n=62 pair of pigeon. The ration of local pigeon consisting of 50%corn+50% of commercial feed for starter broiler chicken can be applied in field. The average of eggproduction was 1.8 eggs/pair/period, egg weight was 17.7 g, fertility was 96.6%, hatching rate was 77%,embryo mortality rate was 23%, interval period from laying to hatching and suckling was 51 days, 31.4days with hatching, and 17.6 days without hatching and suckling. The day old pigeon weight ranged10.9-16.2 g. Repeatability value of productive traits was high, in which egg weight was 0.64 and day oldpigeon weight was 0.737. Repeatability of reproductive traits was low, that was fertility and hatchabilitywas 0.12 and 0.048, respectively. The squab weight increased from week 0 to 4, then decreased in theweek 5. The growth rate was highest at the week 1, then decreased from the week 2 to 5 with thenegative growth rate occur at the 5th week. The squab growth rate followed a quadratic pattern. It wasconcluded that slaughter squab selection could be done at 4th week old.

  5. Steroids pretreatment in assisted reproduction cycles.

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    Sobotka, V; Streda, R; Mardesic, T; Tosner, J; Heracek, J

    2014-01-01

    The objective is to present an overview of trials and appreciate the relevant data on the effect of steroids pretreatment (oral contraceptives, 17β-estradiol and estradiol valerate) in assisted reproduction cycles. The subject of the study is to evaluate the clinical characteristics during steroids pretreatment cycles focused on the prevention of ovarian cysts, the positive contraceptive effect on the onset of regular period during long gonadotropin releasing hormone agonist protocol. In gonadotropin releasing hormone antagonist protocol the review is interested in supporting ovarian stimulation in low responders, the idea of cycle scheduling and improving treatment outcomes. The method is a review from MEDLINE/Pubmed database between 1994 and July 2012. We identified 15 randomised controlled trials (n=3069 patients). One trail (n=83 patients) assessed GnRH agonist protocol with or without steroids pretreatment, 8 trials (n=1884 patients) assessed GnRH antagonist protocols with or without steroids pretreatment and 6 trials (n=1102 patients) assessed GnRH antagonist protocols versus agonist ones with steroid pretreatment. Data demonstrates that oral contraceptives offer the effective prevention of functional ovarian cysts, the predictable onset of period during desensitisation. Existing data suggest that pretreatment with oral contraceptive pills or estradiol valerate give no advantage concerning number of oocytes or pregnancy rate. Pretreatment with oral contraceptive pills aiming to avoid weekend oocytes retrievals has to be more elucidated. In low responders oral contraceptive pill pretreatment may be beneficial in improving ovarian responses by reducing the amount of gonadotropins and the number of days required for ovarian stimulation. Current research indicates that also 17β-estradiol may be encouraging pretreatment in low responders and in cycle scheduling. This article is part of a Special Issue entitled 'Pregnancy and Steroids'.

  6. The reproductive-cell cycle theory of aging: an update.

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    Atwood, Craig S; Bowen, Richard L

    2011-01-01

    The Reproductive-Cell Cycle Theory posits that the hormones that regulate reproduction act in an antagonistic pleiotrophic manner to control aging via cell cycle signaling; promoting growth and development early in life in order to achieve reproduction, but later in life, in a futile attempt to maintain reproduction, become dysregulated and drive senescence. Since reproduction is the most important function of an organism from the perspective of the survival of the species, if reproductive-cell cycle signaling factors determine the rate of growth, determine the rate of development, determine the rate of reproduction, and determine the rate of senescence, then by definition they determine the rate of aging and thus lifespan. The theory is able to explain: 1) the simultaneous regulation of the rate of aging and reproduction as evidenced by the fact that environmental conditions and experimental interventions known to extend longevity are associated with decreased reproductive-cell cycle signaling factors, thereby slowing aging and preserving fertility in a hostile reproductive environment; 2) two phenomena that are closely related to species lifespan-the rate of growth and development and the ultimate size of the animal; 3). the apparent paradox that size is directly proportional to lifespan and inversely proportional to fertility between species but vice versa within a species; 4). how differing rates of reproduction between species is associated with differences in their lifespan; 5). why we develop aging-related diseases; and 6). an evolutionarily credible reason for why and how aging occurs-these hormones act in an antagonistic pleiotrophic manner via cell cycle signaling; promoting growth and development early in life in order to achieve reproduction, but later in life, in a futile attempt to maintain reproduction, become dysregulated and drive senescence (dyosis). In essence, the Reproductive-Cell Cycle Theory can explain aging in all sexually reproductive life

  7. Correlation of normal-range FMR1 repeat length or genotypes and reproductive parameters.

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    Maslow, Bat-Sheva L; Davis, Stephanie; Engmann, Lawrence; Nulsen, John C; Benadiva, Claudio A

    2016-09-01

    This study aims to ascertain whether the length of normal-ranged CGG repeats on the FMR1 gene correlates with abnormal reproductive parameters. We performed a retrospective, cross-sectional study of all FMR1 carrier screening performed as part of routine care at a large university-based fertility center from January 2011 to March 2014. Correlations were performed between normal-range FMR1 length and baseline serum anti-Müllerian hormone (AMH), cycle day 3 follicle stimulating hormone (FSH), ovarian volumes (OV), antral follicle counts (AFC), and incidence of diminished ovarian reserve (DOR), while controlling for the effect of age. Six hundred three FMR1 screening results were collected. One subject was found to be a pre-mutation carrier and was excluded from the study. Baseline serum AMH, cycle day 3 FSH, OV, and AFC data were collected for the 602 subjects with normal-ranged CGG repeats. No significant difference in median age was noted amongst any of the FMR1 repeat genotypes. No significant correlation or association was found between any allele length or genotype, with any of the reproductive parameters or with incidence of DOR at any age (p > 0.05). However, subjects who were less than 35 years old with low/low genotype were significantly more likely to have below average AMH levels compared to those with normal/normal genotype (RR 3.82; 95 % CI 1.38-10.56). This large study did not demonstrate any substantial association between normal-range FMR1 repeat lengths and reproductive parameters.

  8. Association between Thrombophilia and Repeated Assisted Reproductive Technology Failures

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    Kobra Hamdi

    2012-08-01

    Full Text Available Purpose: This study was performed to investigate the incidence of thrombophilic gene mutations in repeated assisted reproductive technology (ART failures. Methods: The prevalence of mutated genes in the patients with a history of three or more previous ART failures was compared with the patients with a history of successful pregnancy following ARTs. The study group included 70 patients, 34 with three or more previously failed ARTs (A and control group consisted of 36 patients with successful pregnancy following ARTs (B. All patients were tested for the presence of mutated thrombophilic genes including factor V Leiden (FVL, Methylenetetrahydrofolate reductase (MTHFR and Prothrombin (G20210A using real-time polymerase chain reaction (RT- PCR. Results: Mutation of FVL gene was detected in 5.9% women of group A (2 of 34 compared with 2.8% women (1 of 36 of control group (P = 0.6. Mutation of MTHFR gene was found in 35.3% (12 cases as compared with 50% (18 cases of control (35.3% versus 50%; P = 0.23. Regarding Prothrombin, only control group had 5.6% mutation (P = 0.49. No significant differences were detected in the incidences of FVL, Prothrombin and MTHFR in the study group A compared with the control group B. Conclusion: The obtained results suggest that thrombophilia does not have a significant effect in ART failures.

  9. Cycles in Repeated Exponentiation Modulo $p^n$

    CERN Document Server

    Glebsky, Lev

    2010-01-01

    Given a number $r$, we consider the dynamical system generated by repeated exponentiations modulo $r$, that is, by the map $u \\mapsto f_g(u)$, where $f_g(u) \\equiv g^u \\pmod r$ and $0 \\le f_g(u) \\le r-1$. The number of cycles of the defined above dynamical system is considered for $r=p^n$.

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

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    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.

  11. Limit Cycles Sparked by Mutation in the Repeated Prisoner's Dilemma

    CERN Document Server

    Toupo, Danielle F P; Strogatz, Steven H

    2015-01-01

    We explore a replicator-mutator model of the repeated Prisoner's Dilemma involving three strategies: always cooperate (ALLC), always defect (ALLD), and tit-for-tat (TFT). The dynamics resulting from single unidirectional mutations are considered, with detailed results presented for the mutations TFT $\\rightarrow$ ALLC and ALLD $\\rightarrow$ ALLC. For certain combinations of parameters, given by the mutation rate $\\mu$ and the complexity cost $c$ of playing tit-for-tat, we find that the population settles into limit cycle oscillations, with the relative abundance of ALLC, ALLD, and TFT cycling periodically. Surprisingly, these oscillations can occur for unidirectional mutations between any two strategies. In each case, the limit cycles are created and destroyed by supercritical Hopf and homoclinic bifurcations, organized by a Bogdanov-Takens bifurcation. Our results suggest that stable oscillations are a robust aspect of a world of ALLC, ALLD, and costly TFT; the existence of cycles does not depend on the deta...

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

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

    2014-12-01

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

  13. Short Cycles in Repeated Exponentiation Modulo a Prime

    CERN Document Server

    Glebsky, Lev

    2009-01-01

    Given a prime $p$, we consider the dynamical system generated by repeated exponentiations modulo $p$, that is, by the map $u \\mapsto f_g(u)$, where $f_g(u) \\equiv g^u \\pmod p$ and $0 \\le f_g(u) \\le p-1$. This map is in particular used in a number of constructions of cryptographically secure pseudorandom generators. We obtain nontrivial upper bounds on the number of fixed points and short cycles in the above dynamical system.

  14. The reproductive cycle of the oyster Crassostrea gasar

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    CHAM Gomes

    Full Text Available The purpose of this study was to analyze the reproductive cycle of the oyster Crassostrea gasar (= C. brasiliana in the field and the laboratory. The reproductive cycle of the animals was evaluated in the field at Sambaqui Beach, Florianópolis, SC (27° 29′18″ S and 48° 32′12″ W from May 2008 through November 2009. In July, the animals were in the resting stage. The early growth stage began in August and was followed by the late growth stage in October. In November and December, the oysters began to enter the mature stage. Females in spawning condition were predominant during these months. The stages of the reproductive cycle were positively associated with temperature (r=0.77, P<0.01 and negatively associated with salinity (r=−0.56, P=0.042. These findings demonstrated that increased temperature and reduced salinity influence the reproductive development of Crassostrea gasar. The condition index (CI of the animals was also associated with the seawater temperature. The highest values of the condition index were observed during the months when the temperature of the seawater was gradually increasing. A laboratory experiment was performed to test the effect of salinity on the reproductive cycle of the oysters. The experiment was conducted in standardized tanks. The animals were conditioned using two salinities (24‰ and 34‰. The salinity regime influenced the development of the gonadal tissue of the oysters. A salinity of 24‰ produced greater reproductive development.

  15. Neuromuscular adjustments of the quadriceps muscle after repeated cycling sprints.

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    Olivier Girard

    Full Text Available PURPOSE: This study investigated the supraspinal processes of fatigue of the quadriceps muscle in response to repeated cycling sprints. METHODS: Twelve active individuals performed 10 × 6-s "all-out" sprints on a cycle ergometer (recovery = 30 s, followed 6 min later by 5 × 6-s sprints (recovery = 30 s. Transcranial magnetic and electrical femoral nerve stimulations during brief (5-s and sustained (30-s isometric contractions of the knee extensors were performed before and 3 min post-exercise. RESULTS: Maximal strength of the knee extensors decreased during brief and sustained contractions (~11% and 9%, respectively; P0.05. While cortical voluntary activation declined (P 40% reduced (P<0.001 following exercise. CONCLUSION: The capacity of the motor cortex to optimally drive the knee extensors following a repeated-sprint test was shown in sustained, but not brief, maximal isometric contractions. Additionally, peripheral factors were largely involved in the exercise-induced impairment in neuromuscular function, while corticospinal excitability was well-preserved.

  16. Detecting small seamounts in AltiKa repeat cycle data

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    Marks, K. M.; Smith, W. H. F.

    2016-12-01

    We present a technique of stacking repeat cycles of satellite altimeter sea surface height profiles that lowers the noise and improves the resolution of small seamounts. Our approach differs from other studies because it uses the median (not the mean) of the stacks, which suppresses outliers. Seamounts as small as 720 m tall are easily detected in stacked 40 Hz AltiKa data profiles, and a 500 m tall seamount is perceptible. Noise variance decreases with an increase in the number of cycles stacked, and RMS noise dips below 2 cm when 11 or more cycles are stacked. Coherence analyses between geoid height and bathymetry show that full wavelengths down to about 10 km can be resolved. Comparisons of study areas with and without seamounts find that signal from small seamounts lies in the 10-28 km waveband. A simple Gaussian band-pass filter based on the seamount waveband passes signals that can be used in seamount detection studies. Such studies may find seamounts <2 km tall that are predicted to be abundant on the ocean floor.

  17. Braking System Modeling and Brake Temperature Response to Repeated Cycle

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    Zaini Dalimus

    2014-12-01

    Full Text Available Braking safety is crucial while driving the passenger or commercial vehicles. Large amount of kinetic energy is absorbed by four brakes fitted in the vehicle. If the braking system fails to work, road accident could happen and may result in death. This research aims to model braking system together with vehicle in Matlab/Simulink software and measure actual brake temperature. First, brake characteristic and vehicle dynamic model were generated to estimate friction force and dissipated heat. Next, Arduino based prototype brake temperature monitoring was developed and tested on the road. From the experiment, it was found that brake temperature tends to increase steadily in long repeated deceleration and acceleration cycle.

  18. Reproductive cycle of grey mullet Mugil cephalus L.

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    Ana Luísa Rente Medeiros

    2014-06-01

    Full Text Available Grey mullet it is an ecological and biologically important species suitable for sustainable aquaculture. It plays an important role for the economy of several Mediterranean countries, where it is produced in aquaculture based on capture of wild juveniles. The capture of wild juveniles for aquaculture it is not sustainable, and therefore the reproductive cycle must be known in order to obtain eggs for larval production. In this species, the reproductive cycle is still not closed for aquaculture purposes. This work presents the results obtained on a study on the reproductive cycle of grey mullet Mugil cephalus L. based on oocyte diameter measured over a period of one year at Olhão Aquaculture Research Center (EPPO. Monthly measures of body weight, standard and fork length of 15 females kept in 18 m3 tanks in natural conditions were recorded. The state of ovarian maturity was evaluated based on the oocyte diameter. The mean length of the females were 56,41 cm ± 26,71 and the weight 1770,91 g ± 5,70 and the results obtained so far suggests that spawning must occur during Summer.

  19. Reproductive outcomes of retransferring retained embryos in blastocyst transfer cycles.

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    Yi, Hyun Jeong; Koo, Hwa Seon; Cha, Sun Hwa; Kim, Hye Ok; Park, Chan Woo; Song, In Ok

    2016-06-01

    To determine the incidence of embryo retention (ER) in the transfer catheter following embryo transfer (ET) in blastocyst transfer and investigate whether retransferring retained embryos has an impact on reproductive outcomes in patients undergoing in vitro fertilization-ET. We retrospectively analyzed the records of 1,131 blastocyst transfers, which comprised 223 single blastocyst transfer (SBT) and 908 double blastocyst transfer (DBT) cycles. Each SBT and DBT group was classified depending on whether ET was performed without retained embryos in the catheter during the first attempt (without-ER group) or whether any retained embryos were found following ET (ER group) for the purpose of comparing reproductive outcomes in a homogenous population. The overall incidence of finding retained embryos was 2.8% (32/1,131). There were no retained embryos in SBT cycles. In DBT cycles, implantation rates (30.0% vs. 26.6%), positive β-hCG rates (57.2% vs. 56.2%), clinical pregnancy rates (45.3% vs. 46.9%), and live birth rates (38.9% vs. 43.8%) were not significantly different between the without-ER and ER groups. There were no significant differences in the mean birth weight (g) 2,928.4±631.8 vs. 2,948.7±497.8 and the mean gestational age at birth (269.3±17.2 days vs. 264.2±25.7 days). A total of nine cases of congenital birth defects were found in this study population. Eight were observed in the without-ER group and one in the ER group. Our results suggest that retransfer of retained embryos does not have any adverse impact on reproductive outcomes in blastocyst transfer cycles. Furthermore, our results support finding that SBT might be advantageous for decreasing the incidence of retained embryos in catheters.

  20. Effects of sediments on the reproductive cycle of corals.

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    Jones, R; Ricardo, G F; Negri, A P

    2015-11-15

    Dredging, river plumes and natural resuspension events can release sediments into the water column where they exert a range of effects on underlying communities. In this review we examine possible cause-effect pathways whereby light reduction, elevated suspended sediments and sediment deposition could affect the reproductive cycle and early life histories of corals. The majority of reported or likely effects (30+) were negative, including a suite of previously unrecognized effects on gametes. The length of each phase of the life-cycle was also examined together with analysis of water quality conditions that can occur during a dredging project over equivalent durations, providing a range of environmentally relevant exposure scenarios for future testing. The review emphasizes the need to: (a) accurately quantify exposure conditions, (b) identify the mechanism of any effects in future studies, and (c) recognize the close interlinking of proximate factors which could confound interpretation of studies. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. THE USE OF HORMONAL METHODS ON GILTS REPRODUCTIVE CYCLES

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    SGURĂ IOANA

    2007-01-01

    Full Text Available The main purpose of the current research was to conduct the reproductive cycle ongilts, using hormonal methods to induce estrus in non-cycling and late pubertal giltsand to group in a short period of time the breedings and, in the same time, to inductfarrowings. The gilts that have made the object of this experiment were distribute intwo equal lots and they were treated with PG 600 (400 I.U. PMSG and 200 I.U.hCG to induce estrus in two consecutive weeks. The main reproductive objectivesthat we have observed were the percentage of gilts that came into heat, the timerange when the gilts showed signs of estrus and the gestation rate after pregnancycheck at 28 and 56 days from breeding. The percentage of the gilts that were in heatafter PG 600 was 67 %. The majority (44.8 % of gilts were in heat after 72-96hours from PG 600. The gestation rate at 28 days after insemination was 64.6 % andat 56 days after insemination was 53.0%.

  2. THE USE OF HORMONAL METHODS ON GILTS REPRODUCTIVE CYCLES

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    IOANA SGURĂ

    2013-12-01

    Full Text Available The main purpose of the current research was to conduct the reproductive cycle on gilts,using hormonal methods to induce estrus in non-cycling and late pubertal gilts and togroup in a short period of time the breedings and, in the same time, to induct farrowings.The gilts that have made the object of this experiment were distribute in two equal lotsand they were treated with PG 600 (400 I.U. PMSG and 200 I.U. hCG to induce estrusin two consecutive weeks. The main reproductive objectives that we have observed werethe percentage of gilts that came into heat, the time range when the gilts showed signs ofestrus and the gestation rate after pregnancy check at 28 and 56 days from breeding.The percentage of the gilts that were in heat after PG 600 was 67 %. The majority (44.8% of gilts were in heat after 72-96 hours from PG 600. The gestation rate at 28 daysafter insemination was 64.6 % and at 56 days after insemination was 53.0%.

  3. Reproductive cycles of Mugil cephalus, Liza ramada and Liza aurata (Teleostei: Mugilidae).

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    Bartulović, V; Dulčić, J; Matić-Skoko, S; Glamuzina, B

    2011-06-01

    The reproductive cycles of three mullet species from the Eastern Adriatic coast were described using several biological parameters (gonado-somatic index, oocyte diameter and sex ratio) to improve knowledge about their reproduction.

  4. Efficient production of bioactive metabolites from Antrodia camphorata ATCC 200183 by asexual reproduction-based repeated batch fermentation.

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    Li, Hua-Xiang; Lu, Zhen-Ming; Geng, Yan; Gong, Jin-Song; Zhang, Xiao-Juan; Shi, Jin-Song; Xu, Zheng-Hong; Ma, Yan-He

    2015-10-01

    Large-scale submerged fermentation (SmF) of Antrodia camphorata (A. camphorata) usually encounters challenges including tedious preparation of mycelial inoculum, long fermentation period (10-14 d), and poor repeatability. Here we developed an asexual reproduction-based repeated batch fermentation (RBF) process for bioactive metabolites production by A. camphorata ATCC 200183. Compared with traditional batch fermentation, production time was shortened to 58 d from 80 d (overall time for eight cycles) using the RBF process established in this study, and accordingly, the productivities of bioactive metabolites (including antrodins) were improved by 40-60%. Kinetic parameters (α is 2.1-18.7 times as β) indicated that the cell growth was the major contribution for bioactive metabolites production. The RBF shows excellent batch-repeatability (Pearson correlation coefficient of 0.998±0.001), together with advantages of energy-efficient, low cost, and labor-saving, RBF process can be implemented to SmF by other filamentous fungi.

  5. Effect of Repeated Stress Treatments During the Follicular Phase and Early Pregnancy on Reproductive Performance of Gilts

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    Soede, N.M.; Roelofs, J.B.; Verheijen, R.J.E.; Schouten, W.G.P.; Hazeleger, W.; Kemp, B.

    2007-01-01

    In pig husbandry, stress is being considered an important cause of impaired reproductive performance. Therefore, an experiment was performed to quantify effects of repeated stressors during the follicular phase and/or during early pregnancy on reproductive performance of gilts. Eighty-one cyclic

  6. An abbreviated repeat dose and reproductive/developmental toxicity test for high production volume chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Scala, R.A.; Bevan, C.; Beyer, B.K. (Exxon Biomedical Sciences, Inc., East Millstone, NJ (United States))

    1992-08-01

    A novel protocol is described for obtaining preliminary data on repeated dose systemic effects and reproductive/developmental toxicity. The test protocol was developed by a group of experts at the request of the U.S. Environmental Protection Agency (EPA) for use as part of a Screening Information Data Set on high production volume chemicals. Interest in this protocol is shared by several regulatory agencies, including the Organization for Economic Cooperation, the European Community, and the EPA. To validate the study protocol, ethylene glycol monomethyl ether (EGME) was used. After a dosing period of approximately 6 weeks, EGME showed both systemic and reproductive/developmental effects similar to those previously reported using standard protocols. Thus, this test protocol may be used as a screening tool for high production volume chemicals.

  7. REPEATABILITY ESTIMATES OF SOME PRODUCTIVE AND REPRODUCTIVE TRAITS IN RED SINDHI CATTLE

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    Muhammad Iqbal Mustafa, Muhammad Khalid Bashir1, Arfan Yousaf2 and Bashir Ahmad

    2002-03-01

    Full Text Available The breeding records of 179 Red Sindhi cattle maintained at the Livestock Experiment Station Hab Choki, Balochistan, during the years 1982-97 were used in the present study. An effort was made to estimate the repeatability for some productive and reproductive traits by using the Mixed model least squares and maximum likelihood procedures. The repeatability estimates for milk yield, lactation length, dry period, service period, gestation period and calving interval were 0.361 ± 0.05, 0.03 ± 0.05, 0.029 ± 0.06, 0.17± 0.06, 0.94 ± 0.55 and 0.167 ± 0.06, respectively in model 1, whereas in model 2 estimates for milk yield, lactation length, dry period, Service period, gestation period and calving interval were 0.354 ± 0.05. 0.041 ± 0.05, 0.040 ± 0.06, 0.173 ± 0.06, 0.98 ± 0.056 and 0.165 ± 0.06, respectively. The repeatability estimates are used in determining the amount of culling that can be safely done on the basis of records. A high estimate of repeatability provides enough evidence for selection or rejection of the individual based on single record. Whereas a low estimate of repeatability justifies accumulation of further records. A moderate estimate of repeatability (0.361 for lactation milk yield obtained in the present study indicates that the cows can be selected for milk yield on the basis of relatively lesser records in the present herd.

  8. Toxicological assessment of heavy straight run naphtha in a repeated dose/reproductive toxicity screening test.

    Science.gov (United States)

    McKee, Richard H; Steup, David; Schreiner, Ceinwen; Podhasky, Paula; Malley, Linda A; Roberts, Linda

    2014-01-01

    Gasoline blending stocks (naphthas) are comprised of normal, iso- and cycloparaffins and aromatic hydrocarbons with carbon numbers ranging from C4 to C12. Heavy straight run naphtha (HSRN, CAS number 64741-41-9) was selected for toxicity screening because substances of this type contain relatively high levels (28%) of cycloparaffins by comparison to other naphtha streams and the data complement toxicity information on other gasoline blending streams. Rats were exposed by inhalation to wholly vaporized material at levels of approximately 100, 500, or 3000 parts per million (ppm) daily to screen the potential for systemic toxicity, neurotoxicity, reproductive toxicity, and developmental effects to postnatal day 4. All animals survived the treatment period. Principal effects of repeated exposure included increased liver weights in males and females, increased kidney weights in males, and histological changes in the thyroid, secondary to liver enzyme induction. These changes were not considered to be toxicologically meaningful and are not relevant to humans. There were no treatment-related effects in functional observation tests or motor activity; no significant reductions in fertility or changes in other reproductive parameters; and no evidence of developmental toxicity in offspring. The overall no observed adverse effect concentration was 3000 ppm (approximately 13, 600 mg/m(3)). In conclusion the HSRN effects on liver and kidney are consistent with the results of other studies of volatile fractions or other naphthas or formulated gasoline, and there were no HSRN effects on neurological developmental or reproductive parameters.

  9. Spliceosomal small nuclear ribonucleoprotein particles repeatedly cycle through Cajal bodies.

    Science.gov (United States)

    Stanek, David; Pridalová-Hnilicová, Jarmila; Novotný, Ivan; Huranová, Martina; Blazíková, Michaela; Wen, Xin; Sapra, Aparna K; Neugebauer, Karla M

    2008-06-01

    The Cajal body (CB) is a nuclear structure closely associated with import and biogenesis of small nuclear ribonucleoprotein particles (snRNPs). Here, we tested whether CBs also contain mature snRNPs and whether CB integrity depends on the ongoing snRNP splicing cycle. Sm proteins tagged with photoactivatable and color-maturing variants of fluorescent proteins were used to monitor snRNP behavior in living cells over time; mature snRNPs accumulated in CBs, traveled from one CB to another, and they were not preferentially replaced by newly imported snRNPs. To test whether CB integrity depends on the snRNP splicing cycle, two human orthologues of yeast proteins involved in distinct steps in spliceosome disassembly after splicing, hPrp22 and hNtr1, were depleted by small interfering RNA treatment. Surprisingly, depletion of either protein led to the accumulation of U4/U6 snRNPs in CBs, suggesting that reassembly of the U4/U6.U5 tri-snRNP was delayed. Accordingly, a relative decrease in U5 snRNPs compared with U4/U6 snRNPs was observed in CBs, as well as in nuclear extracts of treated cells. Together, the data show that particular phases of the spliceosome cycle are compartmentalized in living cells, with reassembly of the tri-snRNP occurring in CBs.

  10. A maximal cycle test with good validity and high repeatability in adults of all ages

    DEFF Research Database (Denmark)

    Eriksen, L; Tolstrup, J S; Larsen, Steen

    2014-01-01

    In 11 680 individuals (18-85 years) maximal oxygen consumption (VO2max) was estimated indirectly in a maximal cycle test using a prediction model developed in a young population (15-28 years). A subsample of 182 individuals (23-77 years) underwent 2 maximal cycle tests with VO2max estimated...... we suggest a new prediction model of VO2max. The maximal cycle test was highly repeatable....

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  12. Latitudinal variation in life-cycle characteristics of Potamogeton pectinatus L.: vegetative growth and asexual reproduction

    NARCIS (Netherlands)

    Pilon, J.; Santamaria, L.; Hootsmans, M.; Van Vierssen, W.

    2003-01-01

    Across latitudinal gradients, environmental conditions that influence plant growth and reproduction largely change. Here we study clonal variation in life-cycle characteristics of the cosmopolitan water plant Potamogeton pectinatus L. across a broad latitudinal range. Two consecutive experiments wer

  13. Resistance of human spermatozoa to cryoinjury in repeated cycles of thaw-refreezing

    Directory of Open Access Journals (Sweden)

    Sidney Verza Jr.

    2009-10-01

    Full Text Available Objective: To study the resistance of human spermatozoa to cryoinjury in repeated cycles of thaw-refreezing by using the fast liquid nitrogen vapor method. Material and Methods: Semen specimens were obtained from sixteen normal and oligozoospermic individuals who required disposal at the sperm bank. Five of them had testicular cancer. Specimens were thawed and an aliquot was removed for analysis. The remaining specimens were refrozen without removing the cryomedia. Repeated freeze-thaw cycles were performed until no motile sperm were observed. Sperm motility, number of motile spermatozoa and viability were determined after thawing. Resistance to cryoinjury was compared between groups and also after each refreezing cycle within groups. Results: Motile spermatozoa were recovered after five and two refreeze-thawing cycles in normozoospermic and oligozoospermic specimens, respectively. There were no significant differences in the recovery of motile spermatozoa between thaws within each group of normal and oligozoospermic specimens, but percentage motility and total number of motile spermatozoa were significantly lower in the oligozoospermic one. Specimens from men with cancer were exposed to six refreeze-thawing cycles. Although recovery of motile spermatozoa was significantly impaired after each thawing, there were no significant differences in the recovery of motile sperm between thaws in cancer and non-cancer groups. Conclusions: Human spermatozoa resist repeated cryopreservation using the fast liquid nitrogen vapor method. Normozoospermic specimens withstand refreezing for an average two cycles longer than oligozoospermic ones. Specimens from cancer patients seem to resist repeated cryoinjury similarly to non-cancer counterparts. Resistance to repeated cryoinjury was related to the initial semen quality.

  14. The estrous cycle of the ewe is resistant to disruption by repeated, acute psychosocial stress.

    Science.gov (United States)

    Wagenmaker, Elizabeth R; Breen, Kellie M; Oakley, Amy E; Tilbrook, Alan J; Karsch, Fred J

    2010-06-01

    Five experiments were conducted to test the hypothesis that psychosocial stress interferes with the estrous cycle of sheep. In experiment 1, ewes were repeatedly isolated during the follicular phase. Timing, amplitude, and duration of the preovulatory luteinizing hormone (LH) surge were not affected. In experiment 2, follicular-phase ewes were subjected twice to a "layered stress" paradigm consisting of sequential, hourly application of isolation, restraint, blindfold, and predator cues. This reduced the LH pulse amplitude but did not affect the LH surge. In experiment 3, different acute stressors were given sequentially within the follicular phase: food denial plus unfamiliar noises and forced exercise, layered stress, exercise around midnight, and transportation. This, too, did not affect the LH surge. In experiment 4, variable acute psychosocial stress was given every 1-2 days for two entire estrous cycles; this did not disrupt any parameter of the cycle monitored. Lastly, experiment 5 examined whether the psychosocial stress paradigms of experiment 4 would disrupt the cycle and estrous behavior if sheep were metabolically stressed by chronic food restriction. Thirty percent of the food-restricted ewes exhibited deterioration of estrous cycle parameters followed by cessation of cycles and failure to express estrous behavior. However, disruption was not more evident in ewes that also encountered psychosocial stress. Collectively, these findings indicate the estrous cycle of sheep is remarkably resistant to disruption by acute bouts of psychosocial stress applied intermittently during either a single follicular phase or repeatedly over two estrous cycles.

  15. Reproductive cycle of the salmon-bellied racer, Mastigodryas melanolomus (Serpentes, Colubridae, from Costa Rica

    Directory of Open Access Journals (Sweden)

    Stephen R. Goldberg

    2006-12-01

    Full Text Available The purpose of this paper is to present new information on the reproductive cycle of M. melanolomus from Costa Rica based onhistological examination of gonadal material from museum specimens. The first information on the timing of the testicular cycle is alsopresented.

  16. Impact of parity on bone metabolism throughout the reproductive cycle in sows.

    Science.gov (United States)

    van Riet, M M J; Millet, S; Liesegang, A; Nalon, E; Ampe, B; Tuyttens, F A M; Maes, D; Janssens, G P J

    2016-04-05

    Bone metabolism fluctuates throughout the reproductive cycle of sows to enable foetal growth and milk production. Although increased bone mineralisation is conceivable in sows during reproduction, a study of mineralisation in function of parity has not been performed. This study evaluated the fluctuations of markers for bone metabolism in primiparous and multiparous sows throughout a reproductive cycle. The experiment included ten multiparous and five primiparous commercial hybrid sows from one herd. The sows were monitored for one reproductive cycle and fed according to commercial dietary standards. Blood samples were taken in the morning before feeding at fixed time intervals before (day -5) and during gestation (insemination (day 0), 21, 42, 63, 84), around parturition (day 108, 112, parturition (115), 118), and during lactation (day 122, 129, 143). Serum osteocalcin (OC) concentration increased in early and mid-gestation (P=0.002) and decreased at the end of gestation (P=0.001), whereas crosslaps (CTX) concentration decreased during early and mid-gestation (P=0.002) and increased towards the end of gestation (P=0.001). Towards the end of lactation serum levels of both markers increased (P=0.007 and 0.013, respectively). For hydroxyproline (HYP) no significant fluctuation in function of the reproductive cycle was detected. Matrix metalloproteinase 2 (MMP2) concentration increased towards parturition for both primiparous and multiparous sows (P=0.001), whereas during lactation no significant fluctuations in function of the reproductive cycle were found. A parity effect was found for OC and CTX (Psows, although in both groups a similar fluctuation throughout the reproductive cycle was observed.

  17. Varenicline impairs extinction and enhances reinstatement across repeated cycles of nicotine self-administration in rats.

    Science.gov (United States)

    Macnamara, Claire L; Holmes, Nathan M; Westbrook, R Fred; Clemens, Kelly J

    2016-06-01

    Varenicline is a partial nicotine receptor agonist widely prescribed as a smoking cessation medication. Repeated (or long-term) use of varenicline has been proposed as a treatment option for tobacco addiction. However the effect of repeated varenicline use on motivation for nicotine is unknown. Here the intravenous nicotine self-administration paradigm in rats was used to model the consequences of varenicline treatment across repeated cycles of administration, extinction and reinstatement. Rats acquired nicotine self-administration across 20 days before undergoing 6 days of extinction, where each extinction session was preceded by a single injection of varenicline or saline. This was followed by a single varenicline-free nicotine-primed reinstatement test. All rats then reacquired nicotine self-administration for 10 days followed by a second cycle of extinction. Across this period, rats either received a second cycle of varenicline (VAR-VAR) or saline (SAL-SAL), or the alternative treatment (SAL-VAR, VAR-SAL), followed by a final reinstatement test. Treatment with varenicline increased responding across the first cycle of extinction, but did not affect responding in the reinstatement test. Across the second cycle, varenicline again increased responding across extinction, and critically, rats treated with varenicline across cycle 1 and saline across cycle 2 (Group VAR-SAL) exhibited more reinstatement than rats in any other group. The effect of VAR on nicotine seeking was not due to its effects on locomotor activity. Instead, the results suggest that a history of VAR can increase vulnerability to reinstatement/relapse when its treatment is discontinued. The possible mechanisms of this increased vulnerability are discussed.

  18. Repeatability and genotypic correlations of reproductive and productive traits of crossbred beef cattle dams.

    Science.gov (United States)

    Silva, L N; Gasparino, E; Torres Júnior, R A A; Euclides Filho, K; Silva, L O C; Alencar, M M; Souza Júnior, M D; Battistelli, J V F; Silva, S C C

    2015-05-22

    Beef cattle production requires reproductive efficiency. However, measures of reproductive traits are not usually collected; consequently, correlated traits that could be used as indicators would be useful. We examined associations between measures of reproductive and productive efficiency that could be used as selection indicators. Data from 194 dams of the genetic groups Angus x Nelore, Caracu x Nelore, and Valdostana x Nelore collected over 4 years were used. The reproductive traits analyzed were days to heat (DH), calving interval (CI), days to calving (DC), and pregnancy rate (PR). The productive traits were dam weight (DW), body condition score (BCS), calf weight (CW), and weaning rate (WR). The effects on the model were: year, genetic group, reproductive status (RS), age, reproductive rest, and breed of bull (CW and WR). Multivariate analyses were performed, using the Bayesian approach via Gibbs sampling. We conclude that the reproductive measures are ineffective as selection indicators, whereas using dam weight may be a good alternative.

  19. Effect of repeated immersion solution cycles on the color stability of denture tooth acrylic resins

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    Paulo Maurício Batista da Silva

    2011-12-01

    Full Text Available OBJECTIVE: Chemical solutions have been widely used for disinfection of dentures, but their effect on color stability of denture tooth acrylic resins after repeated procedures is still unclear. The aim of this in vitro study was to evaluate whether repeated cycles of chemical disinfectants affected the color stability of two denture tooth acrylic resins. MATERIAL AND METHODS: Sixty disc-shaped specimens (40 mm x 3 mm were fabricated from two different brands (Artiplus and Trilux of denture tooth acrylic resin. The specimens from each brand (n=30 were randomly divided into 6 groups (n=5 and immersed in the following solutions: distilled water (control group and 5 disinfecting solutions (1% sodium hypochlorite, 2% sodium hypochlorite, 5.25% sodium hypochlorite, 2% glutaraldehyde, and 4% chlorhexidine gluconate. Tooth color measurements were made by spectrophotometry. Before disinfection, the initial color of each tooth was recorded. Further color measurements were determined after subjecting the specimens to 7, 21, 30, 45, 60, and 90 immersion cycles in each tested solution. Color differences (ΔE* were determined using the CIE L*a*b* color system. Data were analyzed using two-way repeated measures analysis of variance (ANOVA followed by Tukey tests. The significance level was set at 5%. RESULTS: There were statistically significant differences in ΔE* among the 5 disinfectants and water during the 90 cycles of immersion for both denture tooth acrylic resins. Distilled water promoted the greatest color change in both denture tooth acrylic resins, nevertheless none of tested disinfectants promoted ΔE* values higher than 1.0 on these acrylic materials during the 90 cycles of disinfection. CONCLUSIONS: Repeated immersion cycles in disinfecting solutions alter ΔE* values, however these values do not compromise the color of the tested denture tooth acrylic resins because they are imperceptible to the human eye.

  20. The adverse effects of high fat induced obesity on female reproductive cycle and hormones

    Science.gov (United States)

    Donthireddy, Laxminarasimha Reddy

    The prevalence of obesity, an established risk and progression factor for abnormal reproductive cycle and tissue damage in female mice. It leads to earlier puberty, menarche in young females and infertility. There are extensive range of consequences of obesity which includes type-2 diabetes, cardiovascular disease and insulin resistance. Obesity is the interaction between dietary intake, genes, life style and environment. The interplay of hormones estrogen, insulin, and leptin is well known on energy homeostasis and reproduction. The aim of this study is to determine the effect of high fat induced obesity on reproductive cycles and its hormonal abnormalities on mice model. Two week, 3 month and 8 month long normal (WT) and very high fat diet (VHFD) diet course is followed. When mice are fed with very high fat diet, there is a drastic increase in weight within the first week later. There was a significant (pleptin levels in 6 month VHFD treated animals. 2 week, 3 month and 6 month time interval pap smear test results showed number of cells, length of estrous cycle and phases of the estrous cycle changes with VHFD mice(n=30) compared to normal diet mice(n=10). These results also indicate that the changes in the reproductive cycles in VHFD treated female mice could be due to the changes in hormones. Histo-pathological analyses of kidney, ovary, liver, pancreas, heart and lungs showed remarkable changes in some tissue on exposure to very high fat. Highly deposited fat packets observed surrounding the hepatocytes and nerve cells.

  1. Live-Birth Rate Associated With Repeat In Vitro Fertilization Treatment Cycles.

    Science.gov (United States)

    Smith, Andrew D A C; Tilling, Kate; Nelson, Scott M; Lawlor, Debbie A

    The likelihood of achieving a live birth with repeat in vitro fertilization (IVF) is unclear, yet treatment is commonly limited to 3 or 4 embryo transfers. To determine the live-birth rate per initiated ovarian stimulation IVF cycle and with repeated cycles. Prospective study of 156,947 UK women who received 257,398 IVF ovarian stimulation cycles between 2003 and 2010 and were followed up until June 2012. In vitro fertilization, with a cycle defined as an episode of ovarian stimulation and all subsequent separate fresh and frozen embryo transfers. Live-birth rate per IVF cycle and the cumulative live-birth rates across all cycles in all women and by age and treatment type. Optimal, prognosis-adjusted, and conservative cumulative live-birth rates were estimated, reflecting 0%, 30%, and 100%, respectively, of women who discontinued due to poor prognosis and having a live-birth rate of 0 had they continued. Among the 156,947 women, the median age at start of treatment was 35 years (interquartile range, 32-38; range, 18-55), and the median duration of infertility for all 257,398 cycles was 4 years (interquartile range, 2-6; range, live-birth rate for the first cycle was 29.5% (95% CI, 29.3%-29.7%). This remained above 20% up to and including the fourth cycle. The cumulative prognosis-adjusted live-birth rate across all cycles continued to increase up to the ninth cycle, with 65.3% (95% CI, 64.8%-65.8%) of women achieving a live birth by the sixth cycle. In women younger than 40 years using their own oocytes, the live-birth rate for the first cycle was 32.3% (95% CI, 32.0%-32.5%) and remained above 20% up to and including the fourth cycle. Six cycles achieved a cumulative prognosis-adjusted live-birth rate of 68.4% (95% CI, 67.8%-68.9%). For women aged 40 to 42 years, the live-birth rate for the first cycle was 12.3% (95% CI, 11.8%-12.8%), with 6 cycles achieving a cumulative prognosis-adjusted live-birth rate of 31.5% (95% CI, 29.7%-33.3%). For women older than 42

  2. Live-birth rate associated with repeat in vitro fertilisation treatment cycles

    Science.gov (United States)

    Smith, Andrew D.A.C.; Tilling, Kate

    2016-01-01

    Importance The likelihood of achieving a live-birth with repeat in-vitro fertilisation (IVF) is unclear, yet treatment is commonly limited to three or four embryo transfers. Objective To determine the live-birth rate per initiated IVF cycle and with repeated cycles. Design, Setting and Participants Prospective study of 156,947 UK women who received 257,398 IVF ovarian stimulation cycles between 2003 and 2010 and were followed until June 2012. Main exposure IVF, with a cycle defined as an episode of ovarian stimulation and all subsequent separate fresh and frozen embryo transfers. Main Outcome(s) Live-birth rate per IVF cycle and the cumulative live-birth rates across all cycles in all women and by age and treatment type. Optimal, prognosis-adjusted and conservative cumulative live-birth rates were estimated, reflecting 0%, 30% and 100% of women discontinuing due to poor prognosis and having a live-birth rate of zero had they continued. Results In all women the live-birth rate for the first cycle was 29.5% (95%CI: 29.3, 29.7). This remained above 20% up to and including the fourth cycle. The cumulative prognosis-adjusted live-birth rate across all cycles continued to increase up to the ninth, with 65.3% (64.8, 65.8) of women achieving a live-birth by the sixth cycle. In women younger than 40 using their own oocytes, the live-birth rate for the first cycle was 32.3% (32.0, 32.5), and remained above 20% up to and including the fourth cycle. Six cycles achieved a cumulative prognosis-adjusted live-birth rate of 68.4% (67.8, 68.9). For women aged 40-42, the live-birth rate for the first cycle was 12.3% (95%CI: 11.8, 12.8), with six cycles achieving a cumulative prognosis-adjusted live-birth rate of 31.5% (29.7, 33.3). For women older than 42 years all rates within each cycle were less than 4%. No age differential was observed among women using donor oocytes. Rates were lower in those with untreated male factor infertility compared to those with any other cause, but

  3. Circadian clock gene expression in the coral Favia fragum over diel and lunar reproductive cycles.

    Science.gov (United States)

    Hoadley, Kenneth D; Szmant, Alina M; Pyott, Sonja J

    2011-05-06

    Natural light cycles synchronize behavioral and physiological cycles over varying time periods in both plants and animals. Many scleractinian corals exhibit diel cycles of polyp expansion and contraction entrained by diel sunlight patterns, and monthly cycles of spawning or planulation that correspond to lunar moonlight cycles. The molecular mechanisms for regulating such cycles are poorly understood. In this study, we identified four molecular clock genes (cry1, cry2, clock and cycle) in the scleractinian coral, Favia fragum, and investigated patterns of gene expression hypothesized to be involved in the corals' diel polyp behavior and lunar reproductive cycles. Using quantitative PCR, we measured fluctuations in expression of these clock genes over both diel and monthly spawning timeframes. Additionally, we assayed gene expression and polyp expansion-contraction behavior in experimental corals in normal light:dark (control) or constant dark treatments. Well-defined and reproducible diel patterns in cry1, cry2, and clock expression were observed in both field-collected and the experimental colonies maintained under control light:dark conditions, but no pattern was observed for cycle. Colonies in the control light:dark treatment also displayed diel rhythms of tentacle expansion and contraction. Experimental colonies in the constant dark treatment lost diel patterns in cry1, cry2, and clock expression and displayed a diminished and less synchronous pattern of tentacle expansion and contraction. We observed no pattern in cry1, cry2, clock, or cycle expression correlated with monthly spawning events suggesting these genes are not involved in the entrainment of reproductive cycles to lunar light cycles in F. fragum. Our results suggest a molecular clock mechanism, potentially similar to that in described in fruit flies, exists within F. fragum.

  4. Testicular activity during different phases of reproductive cycle in the adrenalectomized lizard, Mabuya carinata (SCHN.).

    Science.gov (United States)

    Yajurvedi, H N; Chandramohan, K

    1993-03-01

    The effects of bilateral adrenalectomy on the spermatogenetic and steroidogenic activity of the testis in different phases of the reproductive cycle of Mabuya carinata have been investigated. Adrenalectomy results in a significant decrease in the mean number of spermatogonia and primary spermatocytes, the diameters of the testis and tubule, and the activity levels of delta 5-3 beta-hydroxysteroid dehydrogenase and glucose-6-phosphate dehydrogenase in recrudescent, breeding, regressing, and quiescent phases of the reproductive cycle when compared with those of controls. Further, secondary spermatocytes, spermatids, and spermatozoa were absent in the adrenalectomized lizards in all the phases of the cycle. The results indicate the involvement of the adrenals in the recrudescence and maintenance of testicular activity in M. carinata.

  5. Disrupted reproduction, estrous cycle, and circadian rhythms in female mice deficient in vasoactive intestinal peptide.

    Science.gov (United States)

    Loh, D H; Kuljis, D A; Azuma, L; Wu, Y; Truong, D; Wang, H B; Colwell, C S

    2014-10-01

    The female reproductive cycle is gated by the circadian timing system and may be vulnerable to disruptions in the circadian system. Prior work suggests that vasoactive intestinal peptide (VIP)-expressing neurons in the suprachiasmatic nucleus (SCN) are one pathway by which the circadian clock can influence the estrous cycle, but the impact of the loss of this peptide on reproduction has not been assessed. In the present study, we first examine the impact of the genetic loss of the neuropeptide VIP on the reproductive success of female mice. Significantly, mutant females produce about half the offspring of their wild-type sisters even when mated to the same males. We also find that VIP-deficient females exhibit a disrupted estrous cycle; that is, ovulation occurs less frequently and results in the release of fewer oocytes compared with controls. Circadian rhythms of wheel-running activity are disrupted in the female mutant mice, as is the spontaneous electrical activity of dorsal SCN neurons. On a molecular level, the VIP-deficient SCN tissue exhibits lower amplitude oscillations with altered phase relationships between the SCN and peripheral oscillators as measured by PER2-driven bioluminescence. The simplest explanation of our data is that the loss of VIP results in a weakened SCN oscillator, which reduces the synchronization of the female circadian system. These results clarify one of the mechanisms by which disruption of the circadian system reduces female reproductive success.

  6. Reproductive cycle of Macrobrachium amazonicum females (Crustacea, Palaemonidae

    Directory of Open Access Journals (Sweden)

    CMS. Sampaio

    Full Text Available Macrobrachium amazonicum is considered a favorite Brazilian species of freshwater prawn for cultivation as a result of its quick development and because it is easy to maintain in captivity. The aim of this work is to describe the sexual cycle stages and determine maturation age of the female M. amazonicum, which was collected monthly from June, 2002 to May, 2003 in the Jaguaribe River, Itaiçaba, Ceará. A monthly sample of water was also collected to determine the following parameters: temperature, dissolved oxygen, pH and salinity. A monthly sample of females was selected among the individuals caught, to determine the total weight (W T, carapace length (L C and abdomen+telson length (L A+T and to register the number of non-ovigerous females (NOF and ovigerous females (OF. Determining ovarian maturation stages of M. amazonicum was done in a laboratory by observing macroscopic characters such as coloring, size, location and appearance of ovarians examined by transparent carapace. The first maturation age was determined from the relative frequency of the total length (L T of young and adult females. The environmental parameters of the Jaguaribe River did not hold any influence in the number of individuals collected. A total of 1,337 prawns were sampled, 513 males (38.4% and 824 females (61.6%. The proportion between males and females in the studied population was of 1:1.6. Among the collected females, 492 (50.7% did not carry eggs in their abdomens (NOF and 332 (40.3% carried eggs in their abdomens (OF. There was no record of intact females. Non-ovigerous females with mature ovaries were recorded throughout all the months of collection. The female ovaries were classified as immature (IM, rudimentary (RU, intermediary (IN and mature (M. M. amazonicum females reach their first sexual maturity between 4.5 and 5.5 cm of total length.

  7. Changes in ambient temperature and oxygenation during the proestrus do not affect duration, regularity and repeatability of the estrus cycle in female rats.

    Directory of Open Access Journals (Sweden)

    Grazyna Wójcik

    2009-12-01

    Full Text Available There are a lot of factors affecting the release of hormones from the anterior part of pituitary gland and their interactions with other parts of the endocrine, nervous and immune systems. The special significance of the proestrus phase of the estrous cycle of the rat, during which LH and FSH levels increase, followed by ovulation is known. The short length of the estrous cycle and the well recognized sequence of vaginal lavage cytology make it useful for investigating the influence of a stressful environment on the reproductive function. Short duration and mild changes in environmental conditions is considered as a factor analogous to psychological stress. The study was undertaken to determine the effects of a short duration change in the ambient temperature and oxygenation (30 minutes on the proestrus phase of reproductive cycle and on the repeatability and regularity of phases of the reproductive cycle of Wistar strain rats. The animals were kept under standard conditions and had food and water available ad libitum. The climatic chamber with automatically adjustable and monitored internal parameters (temperature, oxygenation, humidity was used to develop stress conditions. An estimation of the vaginal lavage using the microscope was done to determine the estrous cycle. The animals were divided into 6 groups. On the day of experiment: the control group (CG stayed in the climatic chamber for 30 minutes (ambient temperature 21 degrees C, normoxia - 21% O(2, the five test groups (TG - I - V remained in the climatic chamber for 30 minutes, in the established environmental conditions (I - 21 degrees C, 10% O(2; II - 10 degrees C, 21% O(2; III - 10 degrees C, 10% O(2; IV - 35 degrees C, 21% O(2; V - 35 degrees C, 10% O(2. During the following days after the experiment, a microscopic estimation of vaginal lavage was collected over again. There were no changes of duration and sequence of the present estrous cycle and repeatability of the next cycles

  8. Effect of repeated cycled crystallization on digestibility and molecular structure of glutinous Bora rice starch.

    Science.gov (United States)

    Borah, Pallab Kumar; Deka, Sankar Chandra; Duary, Raj Kumar

    2017-05-15

    The effects of repeated cycled crystallization on the digestibility and molecular structure of glutinous Bora rice starch were investigated. Temperature cycle 4/45°C; cycle duration 5d; time interval of cycles 24h; and starch to water ratio 1:2 were found to be optimum for SDS (slow digestible starch) product development. The SDS content increased from 18.01±2.11% to 82.81±2.34%. An increase in the resistance to digestion, crystallinity, molecular weight, polydispersity and molecular order was observed in the optimal SDS product. Notably, the FT-IR peak at 947cm(-1) and XRD peaks at 2θ≈13° and 20° in the optimal SDS product indicated the formation of V-type complexes even without the presence of co-polymers. Birefringence studies showed a loss of typical Maltese cross in the SDS product and revealed a reorientation of crystalline structures within starch granules, suggestive of imperfect crystallite development.

  9. Effect of Air Pollution on Menstrual Cycle Length-A Prognostic Factor of Women's Reproductive Health.

    Science.gov (United States)

    Merklinger-Gruchala, Anna; Jasienska, Grazyna; Kapiszewska, Maria

    2017-07-20

    Air pollution can influence women's reproductive health, specifically menstrual cycle characteristics, oocyte quality, and risk of miscarriage. The aim of the study was to assess whether air pollution can affect the length of the overall menstrual cycle and the length of its phases (follicular and luteal). Municipal ecological monitoring data was used to assess the air pollution exposure during the monitored menstrual cycle of each of 133 woman of reproductive age. Principal component analyses were used to group pollutants (PM10, SO₂, CO, and NOx) to represent a source-related mixture. PM10 and SO₂ assessed separately negatively affected the length of the luteal phase after standardization (b = -0.02; p = 0.03; b = -0.06; p = 0.02, respectively). Representing a fossil fuel combustion emission, they were also associated with luteal phase shortening (b = -0.32; p = 0.02). These pollutants did not affect the follicular phase length and overall cycle length, neither in single- nor in multi-pollutant models. CO and NOx assessed either separately or together as a traffic emission were not associated with overall cycle length or the length of cycle phases. Luteal phase shortening, a possible manifestation of luteal phase deficiency, can result from fossil fuel combustion. This suggests that air pollution may contribute to fertility problems in women.

  10. Annual Reproductive Cycle and Unusual Embryogenesis of a Temperate Coral in the Mediterranean Sea.

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    Chiara Marchini

    Full Text Available The variety of reproductive processes and modes among coral species reflects their extraordinary regeneration ability. Scleractinians are an established example of clonal animals that can exhibit a mixed strategy of sexual and asexual reproduction to maintain their populations. This study provides the first description of the annual reproductive cycle and embryogenesis of the temperate species Caryophyllia inornata. Cytometric analyses were used to define the annual development of germ cells and embryogenesis. The species was gonochoric with three times more male polyps than female. Polyps were sexually mature from 6 to 8 mm length. Not only females, but also sexually inactive individuals (without germ cells and males were found to brood their embryos. Spermaries required 12 months to reach maturity, while oogenesis seemed to occur more rapidly (5-6 months. Female polyps were found only during spring and summer. Furthermore, the rate of gamete development in both females and males increased significantly from March to May and fertilization was estimated to occur from April to July, when mature germ cells disappeared. Gametogenesis showed a strong seasonal influence, while embryos were found throughout the year in males and in sexually inactive individuals without a defined trend. This unusual embryogenesis suggests the possibility of agamic reproduction, which combined with sexual reproduction results in high fertility. This mechanism is uncommon and only four other scleractinians (Pocillopora damicornis, Tubastraea diaphana, T. coccinea and Oulastrea crispata have been shown to generate their broods asexually. The precise nature of this process is still unknown.

  11. Phenological changes in olive (Ola europaea L. reproductive cycle in southern Spain due to climate change

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    Herminia Garcia-Mozo

    2015-09-01

    LMMs was revealed as an appropriate technique for phenology behaviour analysis displaying both fixed and random interactions. Cultivars grown in the study province are adapted to climate with a synchronized response, although climate change is affecting theolive reproductive cycle in southern Spain; therefore, the timing of pollen release, with subsequent consequences on allergic population as phenological changes, could have impacts on flowering period and pollen production. Further investigation is required of the implications for crop production in Mediterranean ecosystems.

  12. Sex differences in plasma corticosterone in desert tortoises, Gopherus agassizii, during the reproductive cycle.

    Science.gov (United States)

    Lance, V A; Grumbles, J S; Rostal, D C

    2001-04-15

    Blood samples from 30 female and 20 male adult desert tortoises, Gopherus agassizii, were collected at monthly intervals during the annual reproductive cycle (April to October). Plasma corticosterone and the sex steroids in each of the samples were analyzed by radioimmunoassay. Mean corticosterone levels in males were significantly higher than in females (P spermatogenesis and intense male-male combat. These results support similar data from other reptiles that suggest increased glucocorticoid secretion during periods of increased activity and metabolism.

  13. Investigation of repeated dose (90 day oral toxicity, reproductive/developmental toxicity and mutagenic potential of ‘Calebin A’

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    Muhammed Majeed

    2015-01-01

    Full Text Available The present work investigated repeated dose and reproductive toxicity of Calebin A in Wistar rats. A study for assessing the mutagenic potential of Calebin A through an AMES test is also described. Calebin A was orally administered to groups of 10 male and/or 10 female Wistar rats each, assigned to three dose levels (20, 50 and 100 mg/kg/body weight once daily for 90 consecutive days. None of the animals in any of the treatment/control groups exhibited any abnormal clinical signs/behavioral changes, reproductive as well as developmental parameters, or gross and microscopic changes in both male and female rats. Calebin A was also evaluated for its ability to induce reverse mutations at selected loci of Salmonella typhimurium in the presence and absence of Aroclor 1254 induced rat liver S9 cell lines. In conclusion, 100 mg/kg/d of Calebin A is not likely to produce any significant toxic effects in male and female Wistar rats and no reproductive or developmental toxicity was observed at the same dose and hence Calebin A at 100 mg/kg was determined as “No Observed Adverse Effect Level (NOAEL” under the test conditions.

  14. Serum uric acid in relation to endogenous reproductive hormones during the menstrual cycle: findings from the BioCycle study

    Science.gov (United States)

    Mumford, Sunni L.; Dasharathy, Sonya S.; Pollack, Anna Z.; Perkins, Neil J.; Mattison, Donald R.; Cole, Stephen R.; Wactawski-Wende, Jean; Schisterman, Enrique F.

    2013-01-01

    STUDY QUESTION Do uric acid levels across the menstrual cycle show associations with endogenous estradiol (E2) and reproductive hormone concentrations in regularly menstruating women? SUMMARY ANSWER Mean uric acid concentrations were highest during the follicular phase, and were inversely associated with E2 and progesterone, and positively associated with FSH. WHAT IS KNOWN ALREADY E2 may decrease serum levels of uric acid in post-menopausal women; however, the interplay between endogenous reproductive hormones and uric acid levels among regularly menstruating women has not been elucidated. STUDY DESIGN, SIZE, DURATION The BioCycle study was a prospective cohort study conducted at the University at Buffalo research centre from 2005 to 2007, which followed healthy women for one (n = 9) or 2 (n = 250) menstrual cycle(s). PARTICIPANTS/MATERIALS, SETTING, METHODS Participants were healthy women aged 18–44 years. Hormones and uric acid were measured in serum eight times each cycle for up to two cycles. Marginal structural models with inverse probability of exposure weights were used to evaluate the associations between endogenous hormones and uric acid concentrations. MAIN RESULTS AND THE ROLE OF CHANCE Uric acid levels were observed to vary across the menstrual cycle, with the lowest levels observed during the luteal phase. Every log-unit increase in E2 was associated with a decrease in uric acid of 1.1% (β = −0.011; 95% confidence interval (CI): −0.019, −0.004; persistent-effects model), and for every log-unit increase in progesterone, uric acid decreased by ∼0.8% (β = −0.008; 95% CI: −0.012, −0.004; persistent-effects model). FSH was positively associated with uric acid concentrations, such that each log-unit increase was associated with a 1.6% increase in uric acid (β = 0.016; 95% CI: 0.005, 0.026; persistent-effects model). Progesterone and FSH were also associated with uric acid levels in acute-effects models. Of 509 cycles, 42 were anovulatory

  15. Methods of estrus detection and correlates of the reproductive cycle in the sun bear (Helarctos malayanus).

    Science.gov (United States)

    Frederick, Cheryl; Kyes, Randall; Hunt, Kathleen; Collins, Darin; Durrant, Barbara; Wasser, Samuel K

    2010-10-15

    The objective was to explore multiple methods for detecting and characterizing the reproductive cycle of the sun bear (Helarctos malayanus). Thirteen H. m. euryspilus females, loaned from the Malaysian government to US zoos, were used. Fecal metabolite concentrations of estrogen and progesterone were compared to vaginal cytology, changes in genital appearance, and behavior (videotapes and zookeeper observations). Cytology and video behavior were characterized during five hormonally defined states: high, low, and baseline progesterone, estrus, and high estrogen. Among states, there were significant differences in cytology and behavior. Sexual, affiliative, and stereotypic behaviors were highest during estrus, whereas affiliative and social behaviors were lowest during high progesterone. In this captive breeding population, 30.8% of females cycled two or three times a year, 30.8% cycled once a year, and 38.5% did not cycle during this study. Inter-estrus intervals were (mean ± SEM) 115.7 ± 6.3 d (range, 101-131). Spearman rank correlations were significant between both ordinal sexual and affiliative behaviors and vulva swelling and color. Sexual behavior was significantly positively correlated with superficial and keratinized cells, but negatively correlated with parabasal and basophilic cells in cycling females (opposite pattern for appetitive behavior). In conclusion, data for cytology, vulva changes and behavior were consistent with, and complementary to, hormonal data; collectively, they delineated estrus and identified specific reproductive types.

  16. Androgen Receptors Expression in Pituitary of Male Viscacha in relation to Growth and Reproductive Cycle

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    Verónica Palmira Filippa

    2015-01-01

    Full Text Available The aim of this work was to study the androgen receptors (AR expression in pituitary pars distalis (PD of male viscachas in relation to growth and reproductive cycle. AR were detected by immunocytochemistry and quantified by image analysis. Pituitary glands from fetus, immature, prepubertal, and adult viscachas during their reproductive cycle were used. In the fetal PD, the immunoreactivity (ir was mainly cytoplasmic. In immature and prepubertal animals, AR-ir was cytoplasmic (ARc-ir and nuclear (ARn-ir in medial region. In adult animals, ARn-ir cells were numerous at caudal end. AR regionalization varied between the PD zones in relation to growth. In immature animals, the ARn-ir increased whereas the cytoplasmic expression decreased in relation to the fetal glands. The percentage of ARc-ir cells increased in prepubertal animals whereas the nuclear AR expression was predominant in adult viscachas. The AR expression changed in adults, showing minimum percentage in the gonadal regression period. The variation of nuclear AR expression was directly related with testosterone concentration. These results demonstrated variations in the immunostaining pattern, regionalization, and number of AR-ir cells throughout development, growth, and reproductive cycle, suggesting the involvement of AR in the regulation of the pituitary activity of male viscacha.

  17. Compressional behavior of knitted fabrics exposed to repeated wash and wear cycles

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    Stanković Snežana B.

    2006-01-01

    Full Text Available The quality requirements of knitted fabrics nowadays have become highly demanding in terms of appearance and comfort properties. It is well known that yarns are subjected to tension, bending, torsion and compression during the wear and care of apparels. The appropriate selection of raw materials could be the way to reduce the deformation of knits caused by mechanical forces. Keeping in mind the fact that natural fibers and man-made fibers can significantly differ in respect to elastic properties, natural fiber and synthetic fiber knits were produced for the experiment. The experimental material included three different variants of knitted fabrics: 100% hemp knit, 100% PAC knit and hemp 50%/PAC 50% knit. The behavior of knitted fabrics during the relaxation of compression was investigated. In order to indicate the change of the compressional properties of knitted fabrics, the same investigation after undergoing repeated wash and wear cycles (during eight weeks was repeated. Although the structure of the tested samples was the same, there were differences in the compressional behavior of the knitted fabrics. It is obvious that the differences in the elastic properties of hemp and PAC fibers were projected into the knits. Compression curves were drawn in order to obtain an insight into the change of the compressional behavior of knitted fabrics during wear. These curves also enabled a comparative estimation of the compressional behavior of knits made of different yarn components. The surfaces proportional to the work of the compression for each of the cycles, as well as the work of compression between the first and the fifth cycles, of loading-unloading cycles were calculated. In order to compare the tested knitted fabrics, the hysteresis of compression was analyzed from the aspect of ability of elastic recovery. The change in compressional behavior of knits exposed to wear and care cycles was confirmed. However, analysis of the comparative

  18. Repeated Superovulation via PMSG/hCG Administration Induces 2-Cys Peroxiredoxins Expression and Overoxidation in the Reproductive Tracts of Female Mice.

    Science.gov (United States)

    Park, Sun-Ji; Kim, Tae-Shin; Kim, Jin-Man; Chang, Kyu-Tae; Lee, Hyun-Shik; Lee, Dong-Seok

    2015-12-01

    Superovulation induced by exogenous gonadotropin treatment (PMSG/hCG) increases the number of available oocytes in humans and animals. However, Superovulatory PMSG/hCG treatment is known to affect maternal environment, and these effects may result from PMSG/hCG treatment-induced oxidative stress. 2-Cys peroxiredoxins (2-Cys Prxs) act as antioxidant enzymes that protect cells from oxidative stress induced by various exogenous stimuli. Therefore, the objective of this study was to test the hypothesis that repeated PMSG/hCG treatment induces 2-Cys Prx expression and overoxidation in the reproductive tracts of female mice. Immunohistochemistry and western blotting analyses further demonstrated that, after PMSG/hCG treatment, the protein expression levels of 2-Cys Prxs increased most significantly in the ovaries, while that of Prx1 was most affected by PMSG/hCG stimulation in all tissues of the female reproductive tract. Repeated PMSG/hCG treatment eventually leads to 2-Cys Prxs overoxidation in all reproductive organs of female mice, and the abundance of the 2-Cys Prxs-SO2/3 proteins reported here supports the hypothesis that repeated superovulation induces strong oxidative stress and damage to the female reproductive tract. Our data suggest that excessive oxidative stress caused by repeated PMSG/hCG stimulation increases 2-Cys Prxs expression and overoxidation in the female reproductive organs. Intracellular 2-Cys Prx therefore plays an important role in maintaining the reproductive organ environment of female mice upon exogenous gonadotropin treatment.

  19. Assessment of reproductive behavior and hormonal cycles in geriatric western Lowland gorillas.

    Science.gov (United States)

    Margulis, Susan W; Atsalis, Sylvia; Bellem, Astrid; Wielebnowski, Nadja

    2007-03-01

    The population of western lowland gorillas in North American zoos is aging and, as is the case with the aging human population, may have unique physical and social needs. We have documented previously that 25% of aging females (5/22) ceased to show reproductive cycles entirely, and could be defined as menopausal. Approximately 32% of females showed somewhat irregular cycling patterns. We review our hormonal and behavioral findings on reproductive aging in gorillas; describe the range of cycling patterns that we see and how we interpret these; and discuss the implications of these findings for captive management and husbandry of aging gorillas. We monitored fecal hormone metabolites (progestogens) in 30 gorillas and collected simultaneous behavioral data to evaluate the relationship between cyclicity and sexual behavior. We identified and described several discrete patterns of irregular cycling. These included extreme variability of cycle length, cyclic patterns with unusually low progestogen peak concentrations that possibly may not support luteal activity, and large variability in maximum progestogen peak height among cycles. All of these changes are consistent with age-related hormonal changes observed in humans and may be signs of changes in fertility as well. Behaviorally, nearly all cycling females exhibited signs of estrus. Affiliative behavior between male silverbacks and estrous females was observed in the control females, but not the geriatric females. These findings suggest that pre-menopausal females are exhibiting signs of perimenopause. As is the case in humans, such changes in hormone patterns may occur years before the onset of menopause. As enhancements in nutrition, husbandry, and veterinary medicine have led to increased longevity in our zoo populations of apes, it has become imperative that we investigate and better understand associated physiological and behavioral changes in geriatric animals to ensure appropriate management of this increasing

  20. Heat shock protein expression in relation to reproductive cycle in land snails: Implications for survival.

    Science.gov (United States)

    Mizrahi, Tal; Heller, Joseph; Goldenberg, Shoshana; Arad, Zeev

    2011-10-01

    Land snails are subject to daily and seasonal variations in temperature and in water availability and use heat shock proteins (HSPs) as part of their survival strategy. We tested whether the reproductive cycle of land snails affects the endogenous levels of HSPs, and their involvement in the reproductive process. We examined HSP levels in the foot tissue of two Sphincterochila species, S. cariosa and S. zonata, before and after laying eggs, and analyzed the albumen gland (reproductive organ) of both species and eggs of S. cariosa for the presence and quantity of various HSPs. Our study shows reduction in the expression level of Hsp70 isoforms and Hsp90 in S. zonata foot and of Hsp74 in S. cariosa foot during the period preceding egg laying compared to the post-reproductive stage. Hsp70 isoforms and Hsp25 were highly expressed in both large albumen glands and in freshly laid eggs of S. cariosa, whereas large albumen glands of S. zonata expressed mainly Hsp70 isoforms. We conclude that a trade-off between survival and fertility is responsible for the expression level of HSPs in the foot tissue of Sphincterochila snails. Our study shows that HSPs are involved in the reproductive process. We propose that parental provision of HSPs may be part of a "be prepared" strategy of Sphincterochila snails, and that HSPs may play important roles in the survival strategy of land snails during the early life stages. Our observations also highlight the importance of the reproductive status in study of whole organisms, especially when assessing the HSP response to stress.

  1. Immunohistochemical study of pituitary cells in wild and captive Salminus hilarii (Characiformes: Characidae) females during the annual reproductive cycle.

    Science.gov (United States)

    Honji, Renato Massaaki; Nóbrega, Rafael Henrique; Pandolfi, Matias; Shimizu, Akio; Borella, Maria Inês; Moreira, Renata Guimarães

    2013-01-01

    Freshwater fish that live exclusively in rivers are at particular risk from fragmentation of the aquatic system, mainly the species that migrate upriver for reproduction. That is the case of Salminus hilarii, an important migratory species currently classified as "almost threatened" in the São Paulo State (Brazil), facing water pollution, dam construction, riparian habitat destruction and environmental changes that are even more serious in this State. Additionally, this species show ovulation dysfunction in captivity. Our studies focused on the identification and distribution of the pituitary cell types in the adenohypophysis of S. hilarii females, including a morphometric analysis that compares pituitary cells from wild and captive broodstocks during the reproductive annual cycle. The morphology of adenohypophysial cells showed differences following the reproductive cycle and the environment. In general, optical density suggested a higher cellular activity during the previtellogenic (growth hormone) and vitellogenic (somatolactin) stages in both environments. Additionally, the nucleus/cell ratio analysis suggested that growth hormone and somatolactin cells were larger in wild than in captive females in most reproductive stages of the annual cycle. In contrast, prolactin hormone showed no variation throughout the reproductive cycle (in both environments). Morphometrical analyses related to reproduction of S. hilarii in different environmental conditions, suggest that somatolactin and growth hormone play an important role in reproduction in teleost and can be responsible for the regulation of associated processes that indirectly affect reproductive status.

  2. Monoamine fluctuations during the reproductive cycle of the Pacific lion's paw scallop Nodipecten subnodosus.

    Science.gov (United States)

    López-Sánchez, J Armando; Maeda-Martínez, Alfonso N; Croll, Roger P; Acosta-Salmón, Héctor

    2009-11-01

    The Pacific lion's paw scallop Nodipecten subnodosus has been one of the most important commercial species of mollusc in the Baja California peninsula in Mexico since 1990. This species is a functional hermaphrodite with tropical and sub-tropical distributions and experiences wide annual temperature oscillations influencing its physiological functions. We determined norepinephrine (NE), dopamine (DA), and serotonin (5-HT) concentrations in different organs (female and male gonads, digestive gland, adductor muscle, gill, mantle, and foot) of N. subnodosus, at 6 reproductive stages (resting, initial, maturing, mature, partially spent and fully spent). Monoamine concentrations were determined by HPLC fitted with an electrochemical detector. Results indicated that monoamine concentrations increased during maturing stage, peaked at mature stage and declined after spawning. NE concentrations were higher than the rest of monoamines followed by DA, and 5-HT. NE was present in all organs at all reproductive stages. DA concentrations were higher in the gill and digestive gland during all stages. 5-HT was only detectable in the male gonadic portion at all stages except at spent stage. NE was the most abundant neurotransmitter found in the female gonad of N. subnodosus, while 5-HT was the most abundant neurotransmitter found in the male gonad. Furthermore, these two neurotransmitters accumulated in the respective gonad tissues during the initial reproductive stages I to IV and then declined after spawning (stages V and VI). This suggests that this species utilized different neurotransmitters specific for each gender and that this utilization was related to the reproductive cycle.

  3. Effect of photoperiod on serum hormone concentrations during the annual reproductive cycle in geese.

    Science.gov (United States)

    Zhao, X Z; Gao, G L; Wang, H W; Li, Q; Zhang, K S; Zhong, H; Wang, Q G

    2017-03-22

    The poor egg-laying rate of geese hinders the development of the goose industry; therefore, the reproductive performance of geese is an important area of investigation. To evaluate the relationship between photoperiod, reproductive hormones, and reproductive activity during the egg-laying cycle in geese under natural conditions, we collected blood samples from Sichuan white geese and Xupu geese to quantify changes in prolactin (PRL), estradiol (E2), vasoactive intestinal polypeptide (VIP), follicle stimulating hormone (FSH), gonadotropin-inhibitory hormone (GnIH), and luteinizing hormone (LH). We also calculated the rate of egg laying for the two populations during the egg-laying cycle. We show that the egg-laying rate and the serum concentration of some hormones (PRL, E2, VIP, FSH, GnIH, and LH) differed significantly between the two populations during the pre-laying, laying, and ceased-laying periods. Serum LH concentrations may be associated with maturation of the ovary and oviducts, whereas FSH, PRL, and GnIH play important roles in egg laying. These results provide a useful resource for future studies examining the laying rate in geese.

  4. Reproductive cycle and strategy of Anodonta anatina (L., 1758): notes on hermaphroditism.

    Science.gov (United States)

    Hinzmann, Mariana; Lopes-Lima, Manuel; Teixeira, Amilcar; Varandas, Simone; Sousa, Ronaldo; Lopes, Anabela; Froufe, Elsa; Machado, Jorge

    2013-08-01

    Freshwater mussels have decreased dramatically in Iberia over the last decades. These animals are responsible for important ecosystem services such as recycling nutrients and improving water clarity. Under this view a better knowledge on the biological features of these animals is extremely important for future conservation and management actions. In this study the reproductive and gametogenic cycle of Anodonta anatina were studied during 2 years in one population as well as the sex ratio and hermaphroditism in six distinct populations, using standard histology. Gametogenesis was continuous in both sexes and germinal epithelium in early stages of development. Gametes were present throughout the reproductive cycle. Oogenesis and spermatogenesis occurred mainly between January and May. Larvae brooding occurred between September and March and main glochidia discharge occurred over a short period (2-3 weeks) in March. For the sex-ratio and hermaphroditism assessments a variable number of individuals were collected from several populations from lakes and rivers. Previous studies described A. anatina as mainly dioecious with only a few populations presenting occasional hermaphroditism. However, the present study indicates that A. anatina sexual behavior is influenced by environmental conditions, being mainly dioecious in rivers with increased hermaphroditism in standing waters. Although self-fertilization was not confirmed, additional studies with molecular characterization of larvae using fast evolving markers should be used in future studies to enlighten this process. Overall, this study indicates that for more efficient conservation actions and management plans, freshwater mussel reproductive biology should be studied at the population level mainly in the subfamily Anodontinae.

  5. Effect of cold water immersion on repeated cycling performance and limb blood flow.

    Science.gov (United States)

    Vaile, J; O'Hagan, C; Stefanovic, B; Walker, M; Gill, N; Askew, C D

    2011-08-01

    The purpose of the present study was to compare the effects of cold water immersion (CWI) and active recovery (ACT) on resting limb blood flow, rectal temperature and repeated cycling performance in the heat. Ten subjects completed two testing sessions separated by 1 week; each trial consisted of an initial all-out 35-min exercise bout, one of two 15-min recovery interventions (randomised: CWI or ACT), followed by a 40-min passive recovery period before repeating the 35-min exercise bout. Performance was measured as the change in total work completed during the exercise bouts. Resting limb blood flow, heart rate, rectal temperature and blood lactate were recorded throughout the testing sessions. There was a significant decline in performance after ACT (mean (SD) -1.81% (1.05%)) compared with CWI where performance remained unchanged (0.10% (0.71%)). Rectal temperature was reduced after CWI (36.8°C (1.0°C)) compared with ACT (38.3°C (0.4°C)), as was blood flow to the arms (CWI 3.64 (1.47) ml/100 ml/min; ACT 16.85 (3.57) ml/100 ml/min) and legs (CW 4.83 (2.49) ml/100 ml/min; ACT 4.83 (2.49) ml/100 ml/min). Leg blood flow at the end of the second exercise bout was not different between the active (15.25 (4.33) ml/100 ml/min) and cold trials (14.99 (4.96) ml/100 ml/min), whereas rectal temperature (CWI 38.1°C (0.3°C); ACT 38.8°C (0.2°C)) and arm blood flow (CWI 20.55 (3.78) ml/100 ml/min; ACT 23.83 (5.32) ml/100 ml/min) remained depressed until the end of the cold trial. These findings indicate that CWI is an effective intervention for maintaining repeat cycling performance in the heat and this performance benefit is associated with alterations in core temperature and limb blood flow.

  6. Menstrual cycle characteristics and reproductive hormone levels in women exposed to atrazine in drinking water.

    Science.gov (United States)

    Cragin, Lori A; Kesner, James S; Bachand, Annette M; Barr, Dana Boyd; Meadows, Juliana W; Krieg, Edward F; Reif, John S

    2011-11-01

    Atrazine is the most commonly used herbicide in the U.S. and a wide-spread groundwater contaminant. Epidemiologic and laboratory evidence exists that atrazine disrupts reproductive health and hormone secretion. We examined the relationship between exposure to atrazine in drinking water and menstrual cycle function including reproductive hormone levels. Women 18-40 years old residing in agricultural communities where atrazine is used extensively (Illinois) and sparingly (Vermont) answered a questionnaire (n=102), maintained menstrual cycle diaries (n=67), and provided daily urine samples for analyses of luteinizing hormone (LH), and estradiol and progesterone metabolites (n=35). Markers of exposures included state of residence, atrazine and chlorotriazine concentrations in tap water, municipal water and urine, and estimated dose from water consumption. Women who lived in Illinois were more likely to report menstrual cycle length irregularity (odds ratio (OR)=4.69; 95% confidence interval (CI): 1.58-13.95) and more than 6 weeks between periods (OR=6.16; 95% CI: 1.29-29.38) than those who lived in Vermont. Consumption of >2 cups of unfiltered Illinois water daily was associated with increased risk of irregular periods (OR=5.73; 95% CI: 1.58-20.77). Estimated "dose" of atrazine and chlorotriazine from tap water was inversely related to mean mid-luteal estradiol metabolite. Atrazine "dose" from municipal concentrations was directly related to follicular phase length and inversely related to mean mid-luteal progesterone metabolite levels. We present preliminary evidence that atrazine exposure, at levels below the US EPA MCL, is associated with increased menstrual cycle irregularity, longer follicular phases, and decreased levels of menstrual cycle endocrine biomarkers of infertile ovulatory cycles. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Linking lipid dynamics with the reproductive cycle in Baltic cod Gadus morhua

    DEFF Research Database (Denmark)

    Røjbek, Maria; Jacobsen, Charlotte; Tomkiewicz, Jonna

    2012-01-01

    This study describes lipid composition and antioxidants of Baltic cod Gadus morhua L. during the reproductive cycle, and investigates whether they reflect its dominant prey and whether levels of fatty acids important for reproductive performance were low. Reasons for a shift in peak spawning time....... Selective retention of the essential fatty acids docosahexaenoic acid (DHA) and arachidonic acid (ARA) in ovaries during maturation was evident, but despite mobilization from the liver, ARA levels were low in ovaries during late maturation and spawning. Astaxanthin and a-tocopherol accumulated in cod...... ovaries and decreased in late maturing and spawning fish, most likely due to their antioxidant protection activity. The fatty acid composition of cod liver reflected its clupeid prey. The ratio of 18:1n-9 to DHA was almost twice as high in sprat as in herring and indicated the ratio of sprat and herring...

  8. The concept of the sexual reproduction cycle and its evolutionary significance

    Directory of Open Access Journals (Sweden)

    Shu-Nong eBai

    2015-01-01

    Full Text Available The concept of a sexual reproduction cycle (SRC was first proposed by Bai and Xu in 2013 to describe the integration of meiosis, sex differentiation and fertilization. This review discusses the evolutionary and scientific implications of considering these three events as part of a single process. Viewed in this way, the SRC is revealed to be a mechanism for efficiently increasing genetic variation, facilitating adaptation to environmental challenges. It also becomes clear that, in terms of cell proliferation, it is appropriate to contrast mitosis with the entire SRC, rather than with meiosis alone. Evolutionarily, it appears that the SRC was first established in unicellular eukaryotes and that all multicellular organisms evolved within that framework. This concept provides a new perspective into how sexual reproduction evolved, how generations should be defined and how developmental processes of various multicellular organisms should properly be compared.

  9. Reproductive cycle of Glycymeris nummaria (Mollusca: Bivalvia from Mali Ston Bay, Adriatic Sea, Croatia

    Directory of Open Access Journals (Sweden)

    Marija Crnčević

    2013-06-01

    Full Text Available The reproductive cycle of the dog cockle, Glycymeris nummaria (Glycymerididae, was studied using specimens collected monthly from Mali Ston Bay, southeastern Adriatic Sea over the period from January to December 2010. We analysed sex ratios, gonad developmental stages, and oocyte diameters using standard histological techniques. There were no differences in the overall sex ratio and no difference in shell length with respect to sex. Results of a size-frequency analysis of oocyte diameters agreed with a qualitative analysis of gonadal developmental stages, confirming the occurrence of one annual spawning peak from May to July. A significant correlation was identified between mean gonad indices of males and females and condition index. This study provides the first data on the reproductive characteristics of G. nummaria, providing necessary information for the future sustainable management of its potential fishery.

  10. Evaluation of 90 day repeated dose oral toxicity and reproductive/developmental toxicity of 3'-hydroxypterostilbene in experimental animals.

    Science.gov (United States)

    Majeed, Muhammed; Bani, Sarang; Natarajan, Sankaran; Pandey, Anjali; S, Naveed

    2017-01-01

    3'-Hydroxypterostilbene (3'-HPT) is one of the active constituents of Sphaerophysa salsula and Pterocarpus marsupium. Despite many proposed therapeutic applications, the safety profile of 3'-HPT has not been established. The present work investigated 90 day repeated oral dose and reproductive (developmental) toxicity of 3'-HPT as a test substance in rats as per OECD guidelines. 90 day toxicity was conducted in sixty Sprague Dawley rats of each sex (120 rats), grouped into six dosage groups of 0 (control), 0 (control recovery), 20 (low dose), 80 (mid dose), 200 (high dose) and 200 (high dose recovery) mg/kg bwt/day (body weight/day) respectively. For the reproductive toxicity study forty Wistar rats of each sex (80 rats) divided into four dosage groups received 0 (vehicle control), 20 (low dose), 100 (mid dose) and 200 (high dose) mg/kg bwt/day of 3'-HPT respectively for a period of two weeks while pre-mating, mating, on the day before sacrifice, in females during pregnancy and four days of lactation period. Results showed no significant differences in body weight, food intake, absolute organ weight, haematology, with no adverse effects (toxicity) on biochemical values nor any abnormal clinical signs or behavioural changes were observed in any of the control/treatment groups, including reproductive and developmental parameters, gross and histopathological changes. In conclusion, the results suggested a No-Observed-Adverse-Effect-Level (NOAEL) of 200 mg/kg bwt/day in rats after oral administration, implying 3'-HPT did not exhibit any toxicity under the study conditions employed.

  11. Cuckoo Search Algorithm Based on Repeat-Cycle Asymptotic Self-Learning and Self-Evolving Disturbance for Function Optimization

    OpenAIRE

    Jie-sheng Wang; Shu-xia Li; Jiang-di Song

    2015-01-01

    In order to improve convergence velocity and optimization accuracy of the cuckoo search (CS) algorithm for solving the function optimization problems, a new improved cuckoo search algorithm based on the repeat-cycle asymptotic self-learning and self-evolving disturbance (RC-SSCS) is proposed. A disturbance operation is added into the algorithm by constructing a disturbance factor to make a more careful and thorough search near the bird’s nests location. In order to select a reasonable repeat-...

  12. Associations between fish reproductive cycle and the dynamics of metazoan parasite infection.

    Science.gov (United States)

    Simková, Andrea; Jarkovský, Jirí; Koubková, Bozena; Barus, Vlastimil; Prokes, Miroslav

    2005-01-01

    The parasite fauna of the stone loach (Barbatula barbatula) was investigated monthly from May to December 2001. Four parasite species were recorded: Gyrodactylus spp. (Monogenea), Tylodelphys clavata (Digenea), Proteocephalus sagittus (Cestoda), and Raphidascaris acus (Nematoda). The changes in the seasonal dynamics of parasite infection were investigated throughout the 8 months. The potential effect of the reproductive investment of the host, measured by gonad mass and gonado-somatic index (GSI), on the parasite infection was tested against the prediction that, during periods of high reproductive investment (beginning of the breeding period or forming gonads after breeding), the fish are more susceptible to parasite infection. Differences between parasite loads between genders were also hypothesized. Seasonal differences in infection were observed for all parasite species studied. The values of GSI showed a pattern of energy accumulation in the pre-reproductive period and at the beginning of breeding, a decrease during breeding, and an increase in the post-breeding period. A similar pattern was observed for parasite abundance, a strong or weak increase in spring and/or autumn and a decrease during summer (July and August). Positive correlations between the abundance of Gyrodactylus spp. and R. acus and both gonad mass and GSI were found in females after eliminating the effect of fish weight. Our results suggest that stone loach females are more susceptible to parasite infection in periods of higher reproductive investment. The main factor determining the infection of T. clavata was fish size. The abundance of P. sagittus was positively correlated with GSI in the total fish sample with no detectable effect of sex or fish weight. The increase in cestode infection in spring supports the hypothesis that the parasite life cycle could by synchronized with the beginning of host reproduction, probably induced by increasing fish hormone levels in the spring.

  13. Interpopulational differences in the female reproductive cycle of the southwestern Atlantic estuarine crab Chasmagnathus granulatus Dana, 1851 (Brachyura: Grapsoidea: Varunidae

    Directory of Open Access Journals (Sweden)

    Romina B. Ituarte

    2006-12-01

    Full Text Available The female reproductive biology of Chasmagnathus granulatus Dana, a semiterrestrial burrowing crab endemic to the southwestern Atlantic, was compared in two contrasting coastal habitats: San Antonio (SA, marine and Mar Chiquita (MC, estuarial. Mature females were collected monthly for 1.5 years and the ovarian cycle was described using a qualitative scale. Gonadosomatic (GSI and hepatosomatic (HSI indexes were calculated. The highest GSI and HSI occurred early in the reproductive season in SA and during the non-reproductive season in MC. The beginning and duration of the reproductive season also differed between populations: it started later and was shorter in SA. In MC, secondary vitellogenesis continued when the reproductive season had finished, and the ovaries remained fully developed throughout the non-reproductive season (winter. Therefore, females of MC were ready to lay eggs as soon as spring environmental conditions appeared. However, SA females did not attain a fully developed ovary during winter. A limited food supply would restrict the available energy to complete secondary vitellogenesis at the end of the reproductive season in SA, after the last spawning. Thus, the vitellogenic cycle should be completed in the following spring, causing a delay in the beginning of the reproductive period. In addition, the higher temperature amplitude may cause the reproductive period in SA to end early.

  14. Non-target effects of repeated chlorothalonil application on soil nitrogen cycling: The key functional gene study.

    Science.gov (United States)

    Zhang, Manyun; Xu, Zhihong; Teng, Ying; Christie, Peter; Wang, Jun; Ren, Wenjie; Luo, Yongming; Li, Zhengao

    2016-02-01

    The widespread and increasing application of chlorothalonil (CTN) raises concerns about its non-target impacts, but little information is available on the effect of CTN on the key functional genes related to soil nitrogen (N) cycling, especially in the case of repeated applications. In the present study, a microcosm incubation was conducted to determine CTN residues and the impacts on the abundances of key functional genes related to N cycling after repeated CTN applications. The results demonstrated that repeated CTN applications at the recommended application rate and five times the recommended rate led to the accumulation of CTN residue in soil at concentrations of 5.59 and 78.79 mg kg(-1), respectively, by the end of incubation. Real time PCR (RT-PCR) revealed that repeated CTN applications had negative effects on the chiA and aprA gene abundances. There were significantly negative correlations between CTN residues and abundances of AOA and AOB genes. In addition, the abundances of key functional genes involved in soil denitrification were declined by repeated CTN applications with the sole exception of the nosZ gene. This study suggests that repeated CTN applications could lead to the accumulation of CTN residue and generate somewhat inconsistent and erratic effects on the abundances of key functional genes related to soil N cycling.

  15. Safety of multiple repeated cycles of {sup 177}Lu-octreotate in patients with recurrent neuroendocrine tumour

    Energy Technology Data Exchange (ETDEWEB)

    Yordanova, Anna; Essler, Markus; Ahmadzadehfar, Hojjat [University Hospital Bonn, Department of Nuclear Medicine, Bonn (Germany); Mayer, Karin; Brossart, Peter [University Hospital Bonn, Department of Internal Medicine 3, Bonn (Germany); Gonzalez-Carmona, Maria A.; Strassburg, Christian P. [University Hospital Bonn, Department of Internal Medicine 1, Bonn (Germany)

    2017-07-15

    Peptide receptor radionuclide therapy (PRRT) is an effective therapy in patients with a somatostatin receptor-positive neuroendocrine tumour (NET). Still unclear is how many cycles of {sup 177}Lu-octreotate can be repeated while maintaining an acceptable toxicity profile. The purpose of this study was to assess the safety of repeated PRRT in patients with recurrent NET. We retrospectively evaluated data from 15 patients treated with repeated PRRT between 2004 and 2015. The median administered activity was 63.8 GBq (range 52-96.6 GBq) in a median of 9 cycles (range 8-13 cycles). Nonhaematological and haematological toxicities were assessed from clinical reports and laboratory data. The rates of adverse events in three therapy groups were compared: during cycles 1 to 4, cycles 5 to 8, and cycles 9 to 13. Baseline laboratory assessments were also compared with data obtained at the end of treatment. The overall survival in the study patients was compared with survival data in patients who received only a baseline PRRT of three or four cycles. We observed no life-threatening adverse events (CTC-4) during {sup 177}Lu-octreotate treatment. Reversible haematological toxicity (CTC-3) occurred in two patients (13%). No CTC-3/4 nephrotoxicity was recorded. More CTC-3 adverse events were recorded in the first therapy group than in the other two groups. Furthermore, there were no significant changes in the mean values of thrombocytes, leucocytes and serum creatinine before and after therapy. However, the mean haemoglobin levels fell from 14 g/dL to 11 g/dL. Finally, compared with those patients who received three or four cycles, there was a survival benefit in patients treated with repeated PRRT (censored overall survival 85.6 vs. 69.7 months, p < 0.001). Therapy with eight or more cycles of {sup 177}Lu-octreotate was well tolerated and led to a survival benefit in patients with recurrent NET. (orig.)

  16. Serum Macrominerals, Glucose and Triglycerides in Arabian Mares during Different Phases of Reproduction Cycle

    Directory of Open Access Journals (Sweden)

    Samia Meliani*, Bouabdellah Benallou, Miloud Halbouche1, Abdellatif Niar and Abdelkarim Naceri2

    2011-10-01

    Full Text Available The aim of this study was to determine the difference in biochemical serum constituents of Arabian mares during different phases of the reproduction cycle. According to there reproductive status, mares were assigned to one of the following six groups, i.e., filly (n=5, late pregnancy (n=7, early pregnancy (n=11, estrual mares (n=8, infertile mares (n=8 and mares in post partum less than 8 days (n=4. Serum calcium, phosphorus, sodium, potassium, magnesium, glucose and triglycerides were determined. Calcium and phosphorus levels were significantly (P<0.05 higher in infertile and filly group, respectively. Sodium level was significantly lower in infertile than in all other groups and the higher serum level was observed in early pregnant mares. Concerning potassium, mean levels were significantly higher than in filly and the lowest mean values were observed in post foaling mares, however, no significant difference was observed in magnesium levels between all groups. Glucose concentration in early pregnant mares was lower than all other groups, but the difference was significant with mares in estrus and fillies. Triglycerides were significantly (P<0.05 higher in late pregnancy and infertile mares than in filly, in early pregnancy, in estrus and in post foaling mare groups. In this study, results pointed towards the significant influence of reproductive statuses on some biochemical serum constituents in mares.

  17. Life cycle and reproductive parameters of Clerada apicicornis signoret (Hemiptera: Lygaeidae under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Estrella Cárdenas

    2001-01-01

    Full Text Available The life cycle of Clerada apicicornis was determined under laboratory conditions. Mean development times in days were: egg 27.2, nymph I 12.5, nymph II 12, nymph III 13.4, nymph IV 16.4, nymph V 26. The life expectancy of adults ranged from 117 to 317 days (mean 196 days. Based on a cohort of 29 females of C. apicicornis, a horizontal life table was constructed. The following predictive parameters were obtained: net rate of reproduction (Ro = 48.31, intrinsic rate of population increase (r m = 0.153, generation time (Tc = 28.20 weeks, and finite rate of population increment (lambda = 1.16. The reproductive value (Vx for each age class of the cohort females was calculated. The following observed parameters were calculated after mortality in each stage: net rate of reproduction (R'o=13.4, intrinsic rate of population increase (r c' =0.09 , and finite rate of population increment (lambda' =1.1. The generation time (Tc' =27.4 was estimated using the methods of Laughlin and Bengstron. A vertical life table was elaborated and mortality was described for one generation of the cohort.

  18. Estimates of repeatability and heritability of productive and reproductive traits in a herd of Jersey cattle

    Directory of Open Access Journals (Sweden)

    Roman R.M.

    2000-01-01

    Full Text Available Estimates of the repeatability and heritability of 19 measures of performance in Jersey cows were obtained using an animal model with a relationship matrix and a derivative-free restricted maximum likelihood algorithm. The data consisted of 935 records for 374 cows by 69 sires over the period 1969-1987. The estimates were similar to those obtained by ordinary least squares methods reported for the same data set and in other studies, but had smaller error variances. A likelihood ratio test showed agreement between these heritability estimates and those in the literature. The heritability estimates of milk, fat, protein, lactose-mineral, solids-not-fat, and total solids yields were about 0.25; for the corresponding percentages, and for the protein to fat and solids-not-fat to fat ratios, the estimates were 0.50. Heritability estimates were 0.10 or less for the time from parturition to first breeding and for three measures of somatic cell counts. These estimates of heritability in a dairy cattle population in a subtropical environment were not different from those of populations in temperate climates.

  19. reproduction

    African Journals Online (AJOL)

    slow, yet no other field in medicine has integrated new knowledge ... Many countries have introduced tight ethical regulation ... and research, such as human reproductive cloning." Howover ... human pregnancy and birth after embryo donation.

  20. Cloning and Expression Analysis of vasa During the Reproductive Cycle of Korean Rockfish,Sebastes schlegeli

    Institute of Scientific and Technical Information of China (English)

    MU Weijie; WEN Haishen; HE Feng; LI Jifang; LIU Miao; MA Ruiqin; ZHANG Yuanqing

    2013-01-01

    Vasa,which is a conserved member of the DEAD-box protein family,plays an indispensable role in primordial germ cell proliferation.However,the expression of vasa gene during the reproductive cycle in ovoviviparous fish has not been documented.In this study,the full-length sequence of vasa was obtained from the ovary of Korean rockfish (Sebastes schlegeli) using reverse transcription-PCR and rapid amplification of cDNA ends.The Vasa with a mature protein of 650 amino acids showed greatest homology (84%) with giant gourami (Osphronemus goramy) and Pacific bluefin tuna (Thunnus orientalis).The expression of vasa mRNA in Korean rockfish was detected in gonads only,suggesting its specific role in gonadal development.In addition,seasonal changes in the vasa expression levels were examined in gonads by quantitative real-time PCR.The vasa transcript levels in adult testis were found higher during spermatogenesis than during spermiation.The vasa transcript levels remained relatively high at the early ovary stage but declined during ovary maturation in adult female fish.These results suggest that the vasa gene play an important role in spermatogenesis and early oogenesis during the reproductive cycle of Korean rockfish.

  1. Cloning and expression analysis of vasa during the reproductive cycle of Korean rockfish, Sebastes schlegeli

    Science.gov (United States)

    Mu, Weijie; Wen, Haishen; He, Feng; Li, Jifang; Liu, Miao; Ma, Ruiqin; Zhang, Yuanqing; Hu, Jian; Qi, Baoxia

    2013-03-01

    Vasa, which is a conserved member of the DEAD-box protein family, plays an indispensable role in primordial germ cell proliferation. However, the expression of vasa gene during the reproductive cycle in ovoviviparous fish has not been documented. In this study, the full-length sequence of vasa was obtained from the ovary of Korean rockfish ( Sebastes schlegeli) using reverse transcription-PCR and rapid amplification of cDNA ends. The Vasa with a mature protein of 650 amino acids showed greatest homology (84%) with giant gourami ( Osphronemus goramy) and Pacific bluefin tuna ( Thunnus orientalis). The expression of vasa mRNA in Korean rockfish was detected in gonads only, suggesting its specific role in gonadal development. In addition, seasonal changes in the vasa expression levels were examined in gonads by quantitative real-time PCR. The vasa transcript levels in adult testis were found higher during spermatogenesis than during spermiation. The vasa transcript levels remained relatively high at the early ovary stage but declined during ovary maturation in adult female fish. These results suggest that the vasa gene play an important role in spermatogenesis and early oogenesis during the reproductive cycle of Korean rockfish.

  2. Monoamine content during the reproductive cycle of Perna perna depends on site of origin on the Atlantic Coast of Morocco.

    Science.gov (United States)

    Klouche, Mounia S; De Deurwaerdère, Philippe; Dellu-Hagedorn, Françoise; Lakhdar-Ghazal, Nouria; Benomar, Soumaya

    2015-09-09

    Bivalve molluscs such as Perna perna display temporal cycles of reproduction that result from the complex interplay between endogenous and exogenous signals. The monoamines serotonin, dopamine and noradrenaline represent possible endocrine and neuronal links between these signals allowing the molluscs to modulate reproductive functions in conjunction with environmental constraints. Here, we report a disruption of the reproductive cycle of mussels collected from two of three sites along the Moroccan atlantic coast soiled by industrial or domestic waste. Using high pressure liquid chromatography, we show that the temporal pattern of monoamine content in the gonads, pedal and cerebroid ganglia varied throughout the reproductive cycle (resting, developing, maturing, egg-laying) of mussels from the unpolluted site. Marked modification of monoamine tissue content was found between sites, notably in noradrenaline content of the gonads. Discriminant statistics revealed a specific impact of mussel location on the temporal variations of noradrenaline and serotonin levels in gonads and cerebroid ganglia. Correlation analyses showed profound and temporal changes in the monoamine content between organs and ganglia, at the two sites where the reproduction was disrupted. We suggest that environmental constraints lead to profound changes of monoaminergic systems, which thereby compromises the entry of mussels into their reproductive cycle.

  3. Expression of NMS and NMU2R in the pig reproductive axis during the estrus cycle and the effect of NMS on the reproductive axis in vitro.

    Science.gov (United States)

    Yang, Guihong; Su, Juan; Li, Xun; Yao, Yuan; Lei, Zhihai; Yang, Xizhi; Kou, Rui; Liu, Yanpeng

    2009-12-01

    Evidence has revealed that neuromedin S (NMS) and neuromedin U-receptor type-2 (NMU2R) mRNAs are expressed in the central nervous system and reproductive organs. Previous data indicated that variation of NMS and NMU2R was due to the phases of the adult rat hypothalamus estrus cycle. However, the expression and function of NMS in the pig reproductive axis remains unexplored. In this study, 16 virginal gilts were classified into four groups: proestrus, estrus, diestrus 1, and diestrus 2; the expression of NMS and NMU2R in the cyclic pig hypothalamus-pituitary-ovary axis was studied by reverse transcriptaion-polymerase chain reaction (RT-PCR), and the effect of NMS on the reproductive axis in vitro was detected by radioimmunoassay (RIA). The cloned pig NMS and NMU2R sequences were 82% and 90.2% identical to those of the corresponding human homologues, respectively. RT-PCR showed that NMS and NMU2R mRNA expression in the hypothalamus and pituitary changed with the estrus cycle, i.e., with the highest level in the proestrus group and the lowest in the estrus group. In the ovary, NMS and NMU2R expression was highest in the diestrus 2 group and the lowest in the proestrus group. In the in vitro study, different concentrations of NMS induced the release of gonadotropin-releasing hormone, luteinizing hormone, and estradiol at different levels of the reproductive axis. Taken together, the expression pattern of NMS during the estrus cycle and its role in reproductive hormones in vitro provide novel evidences of the potential roles of NMS in the regulation of pig reproduction.

  4. Mother's professional career versus reproductive behaviour in the family life cycle.

    Science.gov (United States)

    Szuman, A

    1994-01-01

    A nationally representative survey of 2753 urban married women aged 20-54 years was conducted in 1989 in Poland. The family life cycle is described as family formation stage (first child is born), family development stage, family stabilization stage (last child is born and first child leaves home), and family shrinking stage (all children leave home). The sample included 69.1% in the family development stage, 20.2% in the stabilization stage, and 10.7% in the shrinking stage. Employment of women increased from 81.1% during the development stage to 89.9% during the stabilization stage. Labor force activity increased over time. The highest professional activity was 93% during the first stabilization stage. Only 5.6% of the sampled women had never worked. 54.8% had worked continually without breaks. Differences in parity among working and nonworking mothers changed over the life cycle. The parity of working mothers during the development stage was 1.85 compared to 2.12 among nonworking mothers. During the stabilization stage parity was 1.87 among working mothers and 2.57 among nonworking mothers. During the shrinking stage, parity was 2.57 among working mothers and 3.23 among nonworking mothers. The average number of children decreases in subsequent cohorts. The average number of children was 2.83 for cohorts married after 1959, 2.25 for cohorts married during 1960-69, and 2.08 for cohorts married during 1970-79. Birth decreases by cohort were quicker among working mothers. The difference between first and last cohort was 0.55 children for working mothers and 0.89 children for nonworking mothers. For all families of working and nonworking mothers in all cohorts and at all family life cycle stages, parity decreased with increased level of education. Little change occurred among mothers who never worked (inactive mothers). Working mothers' families completed reproduction 30 months earlier than inactive mothers. The entire reproductive period shortened between the first

  5. Growth, reproductive biology and life cycle of the vermicomposting earthworm, Perionyx ceylanensis Mich. (Oligochaeta: Megascolecidae).

    Science.gov (United States)

    Karmegam, Natchimuthu; Daniel, Thilagavathy

    2009-10-01

    In the present study, an attempt has been made to study the growth, reproduction and life cycle of the earthworm, Perionyx ceylanensis Mich. in cowdung for the period of 340 days. Results showed that the overall mean growth rate was 1.79, 1.57 and 1.34 mg/worm/day respectively for the worms cultured singly, in batches of four and eight. Cocoon production rate was found between 0.85 and 0.94 cocoons/worm/day and the hatching success between 74.67% and 82.67%. The majority of the cocoons (95.16-96.77%) hatched only one hatchling. Worms raised singly also produced viable cocoons indicating that P. ceylanensis reproduce parthenogenetically. The life cycle of the worms cultured singly was +/-57 days and it was +/-50 days for the worms cultured in batches of four and eight. There is a vast scope to utilize P. ceylanensis for vermiculture practices due to short period of life cycle.

  6. Effect of Cage Type on Fecal Corticosterone Concentration in Buck Rabbits During the Reproductive Cycle.

    Science.gov (United States)

    Cornale, Paolo; Macchi, Elisabetta; Renna, Manuela; Prola, Liviana; Perona, Giovanni; Mimosi, Antonio

    2016-01-01

    Fecal corticosterone concentration (FCC) was measured in 14 buck rabbits individually housed in standard-dimension cages (SC) or in bigger cages (BC; with a volume more than double that of SC and equipped with a plastic foot mat) during 4 consecutive reproductive cycles. Cage type and reproductive phase (estrous synchronization of doe rabbits, artificial insemination, partum, preweaning, and postweaning) were not statistically significant but tendentially affected FCCs (.05 Buck rabbits housed in SC showed higher FCCs than those housed in BC (27.42 pg g(- 1) dried feces and 25.57 pg g(- 1), respectively; SEM = 2.952). The highest FCC values were detected at artificial insemination (BC, 27.91 pg g(- 1); SC, 30.45 pg g(- 1); SEM = 3.520), highlighting that the phase of semen collection could be one of the most critical moments for buck rabbits, although further investigations are needed. These preliminary results suggest that measurement of FCC could be used as an indicator of chronic stress in buck rabbits.

  7. The reproductive seasonality and gametogenic cycle of Acropora cervicornis off Broward County, Florida, USA

    Science.gov (United States)

    Vargas-Ángel, Bernardo; Colley, Susan B.; Hoke, S. Michael; Thomas, James D.

    2006-03-01

    Reproductive characters of the Caribbean reef-building coral Acropora cervicornis were investigated based on histological samples collected from April 2001 through October 2002. Oogenesis commenced in early to mid-October through November and spermatogenesis was initiated from January to March. The onset of gametogenesis was staggered, exhibiting up to approximately a 1-month delay within colonies. In the hermaphroditic polyps, the observed male-to-female gonad ratio was nearly 1:1 and ripe oocytes represented over 70% of the total gonadal volume. Fecundity estimates based on Stage IV ova ranged between 10.4 and 21.8 mm3 per square centimeter per year, comparable to A. cervicornis in Puerto Rico and other broadcasting Indo-Pacific Acropora. Fecundity estimates based on Stage III vitellogenic oocytes indicated statistically significant differences among study sites. Spawning in field conditions was observed in 2001, 2003, and 2004 from 2300 to 2330 h. Gamete release generally occurred synchronously between nights two and seven after the full moon of July or August. However in 2003, multiple, small-scale gamete release episodes occurred over more than one lunar cycle. This coincided with the full moon occurring early in the month of July. While prolific gamete production is reported in this study, low levels of recruitment have been reported for this species. Thus, the highly fragmenting A. cervicornis may rely heavily on asexual reproduction for population maintenance and expansion, and recovery after disturbance may be greatly protracted.

  8. HAEMOGRAM OF NIGERIAN MONGREL BITCH AT DIFFERENT STAGES OF THE REPRODUCTIVE CYCLE

    Directory of Open Access Journals (Sweden)

    G. D. Mshelia, J. D. Amin and S. U. R. Chaudhari

    2005-01-01

    Full Text Available The haematologic parameters of the Nigerian Mongrel bitch were investigated at different stages of the reproductive cycle to determine their clinical values. Results showed that red blood cell (RBC counts were highest during anoestrus, with a mean of 5.09  0.62 x 106/µL, while lowest values were recorded during pregnancy, the difference was significant (P<0.05. White blood cell (WBC counts, packed cell volume (PCV and haemoglobin concentration (Hb showed an increasing pattern from anoestrus to proestrus and then decreased with transition from proestrus to oestrus. Total WBC counts were highest during dioestrus and almost twice the value recorded in pregnancy. It appears that WBC count may be used for pregnancy diagnosis in the Nigerian Mongrel bitch.

  9. An Essential Role for Liver ERα in Coupling Hepatic Metabolism to the Reproductive Cycle

    Directory of Open Access Journals (Sweden)

    Sara Della Torre

    2016-04-01

    Full Text Available Lipoprotein synthesis is controlled by estrogens, but the exact mechanisms underpinning this regulation and the role of the hepatic estrogen receptor α (ERα in cholesterol physiology are unclear. Utilizing a mouse model involving selective ablation of ERα in the liver, we demonstrate that hepatic ERα couples lipid metabolism to the reproductive cycle. We show that this receptor regulates the synthesis of cholesterol transport proteins, enzymes for lipoprotein remodeling, and receptors for cholesterol uptake. Additionally, ERα is indispensable during proestrus for the generation of high-density lipoproteins efficient in eliciting cholesterol efflux from macrophages. We propose that a specific interaction with liver X receptor α (LXRα mediates the broad effects of ERα on the hepatic lipid metabolism.

  10. Prevalence of lameness and claw lesions during different stages in the reproductive cycle of sows and the impact on reproduction results.

    Science.gov (United States)

    Pluym, L M; Van Nuffel, A; Van Weyenberg, S; Maes, D

    2013-07-01

    Lameness in sows is an emerging disease condition with major effects on animal welfare and economics. Yet the direct impact on reproduction results remains unclear. The present field study investigated the impact of lameness and claw lesions throughout the reproductive cycle on (re)production results of sows. In five farms, a total of 491 group-housed sows were followed up for a period of one reproductive cycle. Sows were assessed for lameness every time they were moved to another area in the farm. Claw lesions were scored at the beginning and at the end of the cycle. Reproduction results included the number of live-born piglets, stillborn piglets, mummified fetuses and crushed piglets, weaning-to-oestrus interval and the presence of sows not showing oestrus post weaning, returning to service and aborting. Sows that left the group were recorded and the reason was noted. A mean prevalence of lameness of 5.9% was found, although it depended on the time in the productive cycle. The highest percentage of lame sows (8.1%) was found when sows were moved from the post-weaning to the gestation stable. No significant associations were found between lameness and reproduction parameters with the exception of the effect on mummified foetuses. Wall cracks, white line lesions, heel lesions and skin lesions did have an effect on farrowing performance. Of all sows, 22% left the group throughout the study, and almost half of these sows were removed from the farm. Lameness was the second most important reason for culling. Sows culled because of lameness were significantly younger compared with sows culled for other reasons (parity: 2.6 ± 1.3 v. 4.0 ± 1.8). In conclusion, the present results indicate that lameness mainly affects farm productivity indirectly through its effect on sow longevity, whereas claw lesions directly affect some reproductive parameters. The high percentage of lame sows in the insemination stable indicate that risk factor studies should not only focus on the

  11. Increased Mesohippocampal Dopaminergic Activity and Improved Depression-Like Behaviors in Maternally Separated Rats Following Repeated Fasting/Refeeding Cycles

    Directory of Open Access Journals (Sweden)

    Jeong Won Jahng

    2012-01-01

    Full Text Available We have previously reported that rats that experienced 3 h of daily maternal separation during the first 2 weeks of birth (MS showed binge-like eating behaviors with increased activity of the hypothalamic-pituitary-adrenal axis when they were subjected to fasting/refeeding cycles repeatedly. In this study, we have examined the psychoemotional behaviors of MS rats on the fasting/refeeding cycles, together with their brain dopamine levels. Fasting/refeeding cycles normalized the ambulatory activity of MS rats, which was decreased by MS experience. Depression-like behaviors, but not anxiety, by MS experience were improved after fasting/refeeding cycles. Fasting/refeeding cycles did not significantly affect the behavioral scores of nonhandled (NH control rats. Fasting/refeeding cycles increased dopamine levels not only in the hippocampus but also in the midbrain dopaminergic neurons in MS rats, but not in NH controls. Results demonstrate that fasting/refeeding cycles increase the mesohippocampal dopaminergic activity and improve depression-like behaviors in rats that experienced MS. Together with our previous paper, it is suggested that increased dopamine neurotransmission in the hippocampus may be implicated in the underlying mechanisms by which the fasting/refeeding cycles induce binge-like eating and improve depression-like behaviors in MS rats.

  12. Cuckoo Search Algorithm Based on Repeat-Cycle Asymptotic Self-Learning and Self-Evolving Disturbance for Function Optimization.

    Science.gov (United States)

    Wang, Jie-sheng; Li, Shu-xia; Song, Jiang-di

    2015-01-01

    In order to improve convergence velocity and optimization accuracy of the cuckoo search (CS) algorithm for solving the function optimization problems, a new improved cuckoo search algorithm based on the repeat-cycle asymptotic self-learning and self-evolving disturbance (RC-SSCS) is proposed. A disturbance operation is added into the algorithm by constructing a disturbance factor to make a more careful and thorough search near the bird's nests location. In order to select a reasonable repeat-cycled disturbance number, a further study on the choice of disturbance times is made. Finally, six typical test functions are adopted to carry out simulation experiments, meanwhile, compare algorithms of this paper with two typical swarm intelligence algorithms particle swarm optimization (PSO) algorithm and artificial bee colony (ABC) algorithm. The results show that the improved cuckoo search algorithm has better convergence velocity and optimization accuracy.

  13. Cuckoo Search Algorithm Based on Repeat-Cycle Asymptotic Self-Learning and Self-Evolving Disturbance for Function Optimization

    Directory of Open Access Journals (Sweden)

    Jie-sheng Wang

    2015-01-01

    Full Text Available In order to improve convergence velocity and optimization accuracy of the cuckoo search (CS algorithm for solving the function optimization problems, a new improved cuckoo search algorithm based on the repeat-cycle asymptotic self-learning and self-evolving disturbance (RC-SSCS is proposed. A disturbance operation is added into the algorithm by constructing a disturbance factor to make a more careful and thorough search near the bird’s nests location. In order to select a reasonable repeat-cycled disturbance number, a further study on the choice of disturbance times is made. Finally, six typical test functions are adopted to carry out simulation experiments, meanwhile, compare algorithms of this paper with two typical swarm intelligence algorithms particle swarm optimization (PSO algorithm and artificial bee colony (ABC algorithm. The results show that the improved cuckoo search algorithm has better convergence velocity and optimization accuracy.

  14. Characterization of plasma vitellogenin and sex hormone concentrations during the annual reproductive cycle of the endangered razorback sucker

    Science.gov (United States)

    Hinck, Jo Ellen; Papoulias, Diana M.; Annis, Mandy L.; Tillitt, Donald E.; Marr, Carrie; Denslow, Nancy D.; Kroll, Kevin J.; Nachtmann, Jason

    2011-01-01

    Population declines of the endangered razorback sucker Xyrauchen texanus in the Colorado River basin have been attributed to predation by and competition with nonnative fishes, habitat alteration, and dam construction. The reproductive health and seasonal variation of the reproductive end points of razorback sucker populations are currently unknown. Using nonlethal methods, we characterized the plasma hormonal fluctuations of reproductively mature female and male razorback suckers over a 12-month period in a hatchery by measuring their vitellogenin (VTG) and three sex hormones: 17β-estradiol (E2), testosterone (T), and 11-ketotestosterone (KT). Fish were identified as reproductive or nonreproductive based on their body weight, VTG, and sex hormone profiles. In reproductive females, the E2 concentration increased in the fall and winter, and increases in T and VTG concentrations were generally associated with the spawning period. Mean T concentrations were consistently greater in reproductive females than in nonreproductive females, but this pattern was even more pronounced during the spawning period (spring). Consistently low T concentrations (health and condition may be particularly important to recovery efforts of razorback suckers given that the few remaining wild populations are located in a river where water quality and quantity issues are well documented. In addition to the size, age, and recruitment information currently considered in the recovery goals of this endangered species, reproductive end points could be included as recovery metrics with which to monitor seasonal trends and determine whether repatriated populations are cycling naturally.

  15. SEX-LINKED CHANGES IN PHASE 1 BIOTRANSFORMATION OF PHENOL IN BROOK TROUT OVER AN ANNUAL REPRODUCTIVE CYCLE

    Science.gov (United States)

    The microsomal metabolism of phenol (11 degrees C) over an annual reproductive cycle from June to December has been studied using fall spawning adult brook trout (Salvelinus fontinalis). Incubations were optimized for time, cofactor connection, pH, and microsomal protein concentr...

  16. The total pregnancy potential per oocyte aspiration after assisted reproduction-in how many cycles are biologically competent oocytes available?

    DEFF Research Database (Denmark)

    Lemmen, J G; Rodríguez, N M; Andreasen, L D

    2016-01-01

    PURPOSE: While stimulation of women prior to assisted reproduction is associated with increased success rates, the total biological pregnancy potential per stimulation cycle is rarely assessed. METHODS: Retrospective sequential cohort study of the cumulative live birth rate in 1148 first IVF...

  17. Reproductive cycle of Ensis magnus in the Ría de Pontevedra (NW Spain): Spatial variability and fisheries management implications

    Science.gov (United States)

    Hernández-Otero, A.; Martínez-Castro, C.; Vázquez, E.; Macho, G.

    2014-08-01

    Mesoscale differences in the reproductive cycle of the commercial sword razor clam Ensis magnus (Schumacher, 1817) were studied in six shellfish beds in the Ría de Pontevedra (NW Spain) between March 2008 and July 2010. The GCI accurately described the reproductive cycle as indicated by the histological analysis. Both methods showed that the reproductive cycle was similar at different sites and was characterized by a resting stage during summer and early autumn, initiation of gametogenesis in autumn and a period of successive spawning interspersed with gonad recovery during winter and spring. However, a 15-day to one month delay in advanced stages of gametogenesis and maturation was observed between the inner and the outermost site of the ria, as well as an extended spawning period in the outermost area. Lower bottom seawater temperatures at the outermost sites appeared to delay maturation and to prolong the spawning periods, whereas salinity fluctuations at the innermost sites appeared to reduce the length of the cycle. This study provides the first estimation of the size at which E. magnus reaches sexual maturity in the Iberian Peninsula, determined in 79 mm, and it is also the first work in determining the mesoscale variation in gonadal development of any species of the superfamily Solenoidea. The results highlight the importance of carrying out mesoscale studies of the reproductive biology in coastal fisheries resources. Some of the findings of the present study have already been applied in the rotation scheme of the fishery harvesting plan.

  18. The Statistical Relationship between Product Life Cycle and Repeat Purchase Behavior in Convenience Stores

    Science.gov (United States)

    Mizuno, T.; Takayasu, M.

    The density function of product life cycles in convenience stores is found to follow the Weibull distribution. To clarify the parameters that determine these life cycles, we introduce the conditional market share---defined as the probability that a product is selected by customers only if it had been previously purchased---and the market share without any conditions. The product life cycle is more strongly correlated with the conditional market share of the product than with the latter type of market share.

  19. Aperiodicity in one-way Markov cycles and repeat times of large earthquakes in faults

    CERN Document Server

    Tejedor, Alejandro; Pacheco, Amalio F

    2011-01-01

    A common use of Markov Chains is the simulation of the seismic cycle in a fault, i.e. as a renewal model for the repetition of its characteristic earthquakes. This representation is consistent with Reid's elastic rebound theory. Here it is proved that in {\\it any} one-way Markov cycle, the aperiodicity of the corresponding distribution of cycle lengths is always lower than one. This fact concurs with observations of large earthquakes in faults all over the world.

  20. Estrogenic environmental endocrine-disrupting chemical effects on reproductive neuroendocrine function and dysfunction across the life cycle.

    Science.gov (United States)

    Dickerson, Sarah M; Gore, Andrea C

    2007-06-01

    Endocrine disrupting chemicals (EDCs) are natural or synthetic compounds that interfere with the normal function of an organism's endocrine system. Many EDCs are resistant to biodegradation, due to their structural stability, and persist in the environment. The focus of this review is on natural and artificial EDCs that act through estrogenic mechanisms to affect reproductive neuroendocrine systems. This endocrine axis comprises the hypothalamic gonadotropin-releasing hormone (GnRH), pituitary gonadotropins, and gonadal steroid hormones, including estrogens. Although it is not surprising that EDCs that mimic or antagonize estrogen receptors may exert actions upon reproductive targets, the mechanisms for these effects are complex and involve all three levels of the hypothalamic-pituitary-gonadal (HPG) system. Nevertheless, considerable evidence links exposure to estrogenic environmental EDCs with neuroendocrine reproductive deficits in wildlife and in humans. The effects of an EDC are variable across the life cycle of an animal, and are particularly potent when exposure occurs during fetal and early postnatal development. As a consequence, abnormal sexual differentiation, disrupted reproductive function, or inappropriate sexual behavior may be detected later in life. This review will cover the effects of two representative classes of estrogenic EDCs, phytoestrogens and polychlorinated biphenyls (PCBs), on neuroendocrine reproductive function, from molecules to behavior, across the vertebrate life cycle. Finally, we identify the gaps of knowledge in this field and suggest future directions for study.

  1. Repeated freeze-thaw cycles do not alter the biomechanical properties of fibular allograft bone.

    Science.gov (United States)

    Shaw, Joshua M; Hunter, Shawn A; Gayton, J Christopher; Boivin, Gregory P; Prayson, Michael J

    2012-03-01

    Allograft tissues can undergo several freeze-thaw cycles between donor tissue recovery and final use by surgeons. However, there are currently no standards indicating the number of reasonable freeze-thaw cycles for allograft bone and it is unclear how much a graft may be degraded with multiple cycles. We therefore asked whether (1) the mechanical properties of fibular allograft bone would remain unchanged with increasing numbers of freeze-thaw cycles and (2) histologic alterations from increased numbers of freeze-thaw cycles would correspond to any mechanical changes. Fibular allograft segments were subjected to two, four, and eight freeze-thaw cycles and compared biomechanically and histologically with a control group (one freeze-thaw cycle). Two freeze-dried treatments, one after being subjected to one freeze-thaw cycle and the other after being subjected to three freeze-thaw cycles, also were compared with the control group. For all segments, the average ultimate stress was 174 MPa, average modulus was 289 MPa, average energy was 2.00 J, and the average stiffness was 1320 N/mm. The material properties of the freeze-thaw treatment groups were similar to those of the control group: ultimate stress and modulus were a maximum of 16% and 70% different, respectively. Both freeze-dried treatments showed increased stiffness (maximum 53% ± 71%) and energy to failure (maximum 117% ± 137%) but did not exhibit morphologic differences. There were no alterations in the histologic appearance of the bone sections in any group. Fibular allograft segments can be refrozen safely up to eight times without affecting the biomechanical or morphologic properties. Freeze-dried treatments require further study to determine whether the detected differences are caused by the processing. Cryopreserved cortical allografts are thawed by surgeons in preparation for procedures and then occasionally discarded when not used. Refreezing allograft tissues can result in a cost savings because of a

  2. Effect of repeated sterilization cycles on the physical properties of scaling instruments: a scanning electron microscopy study.

    Science.gov (United States)

    Porto, Alessandra Nogueira; Borges, Álvaro Henrique; Semenoff-Segundo, Alex; Raslan, Suzane A; Pedro, Fábio Luis Miranda; Jorge, Antônio Olavo Cardoso; Bandeca, Matheus Coelho

    2015-05-01

    Repeated sterilizations cycles cause undesirable alterations in the material properties of the instruments, such as corrosion, alterations in the hardness of the metal and the loss of the cutting sharpness of the instrument. This research examined the effect of repeated dry heat sterilization and autoclaves cycles on carbon steel (CS) and stainless steel (SS) curettes during the scaling and root planning. A total of 77 Gracey curettes were used in this study. Of these, 35 were SS and 42 were CS curettes submitted in different process: Dry heat, autoclave, inhibition of corrosion and autoclave, scaling, root planning and dry heat, scaling, root planning, inhibition of corrosion and autoclave. The inhibition of corrosion used on the carbon curettes (prior to sterilization in the autoclave) was sodium nitrite at 2%. The curettes received 10 consecutive cycles of sterilization and after that the cutting edges were examined in the electronic microscope, at 60 and 100 magnification times. The images were evaluated by three independent examiners, who compared the photographs of each group with the control group. The surface corrosion products and a deterioration of the edges were observed and the results showed that the SS curettes suffered little alteration with sterilization, scaling, root planning whereas the CS curettes were visibly affected by sterilization in the autoclave, but when the inhibition of corrosion was used prior to the sterilization, the oxidation was considerably reduced.

  3. Effect of Air Pollution on Menstrual Cycle Length—A Prognostic Factor of Women’s Reproductive Health

    Directory of Open Access Journals (Sweden)

    Anna Merklinger-Gruchala

    2017-07-01

    Full Text Available Air pollution can influence women’s reproductive health, specifically menstrual cycle characteristics, oocyte quality, and risk of miscarriage. The aim of the study was to assess whether air pollution can affect the length of the overall menstrual cycle and the length of its phases (follicular and luteal. Municipal ecological monitoring data was used to assess the air pollution exposure during the monitored menstrual cycle of each of 133 woman of reproductive age. Principal component analyses were used to group pollutants (PM10, SO2, CO, and NOx to represent a source-related mixture. PM10 and SO2 assessed separately negatively affected the length of the luteal phase after standardization (b = −0.02; p = 0.03; b = −0.06; p = 0.02, respectively. Representing a fossil fuel combustion emission, they were also associated with luteal phase shortening (b = −0.32; p = 0.02. These pollutants did not affect the follicular phase length and overall cycle length, neither in single- nor in multi-pollutant models. CO and NOx assessed either separately or together as a traffic emission were not associated with overall cycle length or the length of cycle phases. Luteal phase shortening, a possible manifestation of luteal phase deficiency, can result from fossil fuel combustion. This suggests that air pollution may contribute to fertility problems in women.

  4. Effect of Air Pollution on Menstrual Cycle Length—A Prognostic Factor of Women’s Reproductive Health

    Science.gov (United States)

    Merklinger-Gruchala, Anna; Jasienska, Grazyna; Kapiszewska, Maria

    2017-01-01

    Air pollution can influence women’s reproductive health, specifically menstrual cycle characteristics, oocyte quality, and risk of miscarriage. The aim of the study was to assess whether air pollution can affect the length of the overall menstrual cycle and the length of its phases (follicular and luteal). Municipal ecological monitoring data was used to assess the air pollution exposure during the monitored menstrual cycle of each of 133 woman of reproductive age. Principal component analyses were used to group pollutants (PM10, SO2, CO, and NOx) to represent a source-related mixture. PM10 and SO2 assessed separately negatively affected the length of the luteal phase after standardization (b = −0.02; p = 0.03; b = −0.06; p = 0.02, respectively). Representing a fossil fuel combustion emission, they were also associated with luteal phase shortening (b = −0.32; p = 0.02). These pollutants did not affect the follicular phase length and overall cycle length, neither in single- nor in multi-pollutant models. CO and NOx assessed either separately or together as a traffic emission were not associated with overall cycle length or the length of cycle phases. Luteal phase shortening, a possible manifestation of luteal phase deficiency, can result from fossil fuel combustion. This suggests that air pollution may contribute to fertility problems in women. PMID:28726748

  5. Reproductive biology of the endangered percid Zingel asper in captivity: a histological description of the male reproductive cycle

    Directory of Open Access Journals (Sweden)

    Christine Chevalier

    2011-10-01

    Full Text Available The endemic Rhodanian percid Zingel asper (Linnaeus, 1758, is usually found throughout the Rhônebasin, but this fish is now in sharp decline. Understanding its reproductive physiology is important so as to be ableto artificially control its reproduction with a view to re-introducing it. This study was carried out on a populationobtained by artificial fertilization and bred in external tanks. Fishes were observed from the juvenile stages throughto adulthood. Patterns of testicular development were defined from histological observations. Testes of Z. asperwere paired, elongated and fusiform dorsocaudal organs. The two lobes of each gonad joined together to forma duct that extended to the urogenital papillae. They showed a lobular structure. The testicular lobules were of theunrestricted spermatogonial type. Up to 10 months-old, most of the males were immature: their testes showed onlytype A spermatogonia. The appearance of type B spermatogonia in the lobules of a testis indicated the beginningof spermatogenesis in 10 months-old fish. Spermiogenesis occurred 24 months after the fertilization and, in 26months-old fish, the cyst opened and released spermatozoa into the lumen of lobules. The spermiation belonged toa cystic type. During the third year, histological observations pointed to the same evolution of adult gonads asduring the second year. Sexual maturity was reached in captive Z. asper after two years. The spawning occurred inMay in the breeding conditions. (Folia Histochemica et Cytobiologica 2011, Vol. 49, No. 3, 486–496

  6. Reproductive biology of the endangered percid Zingel asper in captivity: a histological description of the male reproductive cycle.

    Science.gov (United States)

    Chevalier, Christine; de Conto, Christine; Exbrayat, Jean-Marie

    2011-01-01

    The endemic Rhodanian percid Zingel asper (Linnaeus, 1758), is usually found throughout the Rhône basin, but this fish is now in sharp decline. Understanding its reproductive physiology is important so as to be able to artificially control its reproduction with a view to re-introducing it. This study was carried out on a population obtained by artificial fertilization and bred in external tanks. Fishes were observed from the juvenile stages through to adulthood. Patterns of testicular development were defined from histological observations. Testes of Z. asper were paired, elongated and fusiform dorsocaudal organs. The two lobes of each gonad joined together to form a duct that extended to the urogenital papillae. They showed a lobular structure. The testicular lobules were of the unrestricted spermatogonial type. Up to 10 months-old, most of the males were immature: their testes showed only type A spermatogonia. The appearance of type B spermatogonia in the lobules of a testis indicated the beginning of spermatogenesis in 10 months-old fish. Spermiogenesis occurred 24 months after the fertilization and, in 26 months-old fish, the cyst opened and released spermatozoa into the lumen of lobules. The spermiation belonged to a cystic type. During the third year, histological observations pointed to the same evolution of adult gonads as during the second year. Sexual maturity was reached in captive Z. asper after two years. The spawning occurred in May in the breeding conditions.

  7. Reproductive cycle of Anomalocardia brasiliana (Mollusca: Bivalvia: Veneridae) in the estuary of the Cachoeira River, Ilhéus, Bahia.

    Science.gov (United States)

    Luz, J R; Boehs, G

    2011-08-01

    The aim of this study was to characterize the reproductive cycle of Anomalocardia brasiliana, typical of the estuarine region of the Cachoeira River, Ilhéus, Bahia, Brazil. For this purpose, 20 specimens were collected biweekly between August 2005 and August 2006 on an intertidal bank (14º 48' 23" S and 39º 02' 47" W). The animals were measured on the anteroposterior axis (length), examined macroscopically and removed from the shell and fixed in Davidson's solution. Subsequently, the tissues were impregnated in paraffin, cut into 7 mm sections and stained with Harris hematoxylin and eosin (HE). The slides were examined under a light microscope. The water temperature at the site ranged from 24 to 30.5 ºC (mean: 27.4 ºC; SD ± 1.9), salinity from zero to 23 (mean: 13.7; SD ± 7.5) and rainfall from 28.3 mm to 248.8 mm monthly (yearly mean: 130 mm). The sample (n = 478) showed a sex ratio (M: F) of 1: 1.2 (p reproductive synchrony. The reproductive cycle was continuous, with releases of gametes mainly in spring, summer and autumn. These results are similar to those found in other regions, but there was no reproductive rest period as reported for populations in higher latitudes.

  8. Non-linear association between androgen receptor CAG and GGN repeat lengths and reproductive parameters in fertile European and Inuit men.

    Science.gov (United States)

    Brokken, L J S; Rylander, L; Jönsson, B A; Spanò, M; Pedersen, H S; Ludwicki, J K; Zviezdai, V; Bizzaro, D; Manicardi, G C; Toft, G; Bonde, J P; Giwercman, A; Lundberg Giwercman, Y

    2013-05-06

    Recently the dogma that there is an inverse linear association between androgen receptor (AR) CAG and GGN polymorphisms and receptor activity has been challenged. We analysed the pattern of association between 21 male reproductive phenotypes and AR CAG/GGN repeat lengths in 557 proven-fertile men. A linear association was only found between sperm DNA fragmentation index (DFI) and CAG length, and between inhibin B and GGN length. Men with longer CAG then the reference (22-24), had higher oestradiol levels, whereas men with shorter CAG stretches had a higher DFI and a higher proportion of Fas-positive germ cells. Subjects with either short or long CAG had increased seminal levels of prostate-specific antigen and neutral α-glucosidase activity. Compared to men with the median GGN length of 23, those with shorter GGN repeats had higher levels of inhibin B, higher proportions of normal and progressive sperm, and a higher fraction of Fas-positive sperm, while men with longer GGN had higher oestradiol levels. These data indicate that at least for some markers of male reproductive function the association with CAG or GGN repeat length is curvilinear.

  9. Effect of cold water immersion on repeated 1-km cycling performance in the heat.

    Science.gov (United States)

    Peiffer, Jeremiah J; Abbiss, Chris R; Watson, Greig; Nosaka, Kazunori; Laursen, Paul B

    2010-01-01

    This study examined the effect of a short cold water immersion (CWI) intervention on rectal and muscle temperature, isokinetic strength and 1-km cycling time trial performance in the heat. Ten male cyclists performed a 1-km time trial at 35.0+/-0.3 degrees C and 40.0+/-3.0% relative humidity, followed by 20 min recovery sitting in either cold water (14 degrees C) for 5 min or in 35 degrees C air (control); a second 1-km time trial immediately followed. Peak and mean cycling power output were recorded for both time trials. Rectal and muscle temperature, and maximal isokinetic concentric torque of the knee extensors were measured before and immediately after the first and second time trials. Rectal temperature was not different between cold water immersion and control conditions at any time points. After the second time trial, however, muscle temperature was significantly lower (-1.3+/-0.7 degrees C) in cold water immersion compared with the control trial. While peak and mean power decreased from the first to second time trial in both conditions (-86+/-54 W and -24+/-16 W, respectively), maximal isokinetic concentric torque was similar between conditions at all time points. The 5 min cold water immersion intervention lowered muscle temperature but did not affect isokinetic strength or 1-km cycling performance. Copyright (c) 2008 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  10. Beyond debuttressing: Mechanics of paraglacial rock slope damage during repeat glacial cycles

    Science.gov (United States)

    Grämiger, Lorenz M.; Moore, Jeffrey R.; Gischig, Valentin S.; Ivy-Ochs, Susan; Loew, Simon

    2017-04-01

    Cycles of glaciation impose mechanical stresses on underlying bedrock as glaciers advance, erode, and retreat. Fracture initiation and propagation constitute rock mass damage and act as preparatory factors for slope failures; however, the mechanics of paraglacial rock slope damage remain poorly characterized. Using conceptual numerical models closely based on the Aletsch Glacier region of Switzerland, we explore how in situ stress changes associated with fluctuating ice thickness can drive progressive rock mass failure preparing future slope instabilities. Our simulations reveal that glacial cycles as purely mechanical loading and unloading phenomena produce relatively limited new damage. However, ice fluctuations can increase the criticality of fractures in adjacent slopes, which may in turn increase the efficacy of fatigue processes. Bedrock erosion during glaciation promotes significant new damage during first deglaciation. An already weakened rock slope is more susceptible to damage from glacier loading and unloading and may fail completely. We find that damage kinematics are controlled by discontinuity geometry and the relative position of the glacier; ice advance and retreat both generate damage. We correlate model results with mapped landslides around the Great Aletsch Glacier. Our result that most damage occurs during first deglaciation agrees with the relative age of the majority of identified landslides. The kinematics and dimensions of a slope failure produced in our models are also in good agreement with characteristics of instabilities observed in the field. Our results extend simplified assumptions of glacial debuttressing, demonstrating in detail how cycles of ice loading, erosion, and unloading drive paraglacial rock slope damage.

  11. Annual cycles of urinary reproductive steroid concentrations in wild and captive endangered Fijian ground frogs (Platymantis vitiana).

    Science.gov (United States)

    Narayan, Edward J; Molinia, Frank C; Christi, Ketan S; Morley, Craig G; Cockrem, John F

    2010-03-01

    Annual cycles of reproductive steroid metabolites were measured in urine collected from free-living and captive tropical endangered Fijian ground frogs (Platymantis vitiana) a terrestrial breeding. Free-living frogs were sampled on Viwa Island, Fiji and captive frogs were maintained in an outdoor enclosure in Suva, Fiji. Urinary estrone, progesterone and testosterone metabolite concentrations increased in male and female frogs after hCG challenges, with clear peaks in steroid concentrations 2 or 3 days after the challenges. There were annual cycles of testosterone metabolites in wild and captive males, and of estrone and progesterone metabolites in wild and captive females. Peaks of steroid concentrations in the wet season corresponded with periods of mating and egg laying in females in December and January. Steroid concentrations declined in January and February when maximum egg sizes in females were also declining. Body weights of wild male and vitellogenic female frogs showed annual cycles. Body weights of non-vitellogenic female frogs varied significantly between months, although there was no clear pattern of annual changes. Body weights of the 3 captive male frogs and 4 captive female frogs were similar to those of the wild frogs. Estrone metabolites were 80% successful in identifying non-vitellogenic females from males. The results suggest that the Fijian ground frog is a seasonal breeder with an annual gonadal cycle, and this species is likely to be photoperiodic. Urinary steroid measurements can provide useful information on reproductive cycles in endangered amphibians.

  12. Phenological changes in olive (Ola europaea L. reproductive cycle in southern Spain due to climate change

    Directory of Open Access Journals (Sweden)

    Herminia Garcia-Mozo

    2015-09-01

    Full Text Available Introduction. Modifications of crop species phenology due to a changing environment are of interest because of their impact on fruit set and final harvest. Pre-flowering and flowering phenophases in olive groves at different sites of southern Spain were examined, in order to chart potential trends and determine major correlations with weather-related parameters, especially temperature and water availability. The high prevalence of olive pollen allergy in the Mediterranean population makes this study highly relevant. Materials and methods. Ten sites in Cordoba province (Spain during a 17-year period (1996–2012. BBCH phenology scale. Meteorological data from 1960 were analyzed; data from 1996 included on modeling analysis. Linear Mixed Models (LMMs were developed, combining phenological and meteorological data. Results. Since 1960, local spring temperatures have increased 1.5ºC, the number of spring rainfall days has fallen 11 days, total rainfall has declined 150 mm. Despite phenological differences between sites, attributable to altitude, phenological development during the season followed a similar pattern. Flowering dates advanced 2 days, while inflorescence emergence was delayed 24 days. Trend slopes revealed differences, an earlier period (1996–2002 with a sharp flowering advance of 15 days, and a later period (2003–2012 characterized by a gradual advance and a high bud emergence delay of 22 days. Conclusions. LMMs was revealed as an appropriate technique for phenology behaviour analysis displaying both fixed and random interactions. Cultivars grown in the study province are adapted to climate with a synchronized response, although climate change is affecting theolive reproductive cycle in southern Spain; therefore, the timing of pollen release, with subsequent consequences on allergic population as phenological changes, could have impacts on flowering period and pollen production. Further investigation is required of the implications

  13. Microencapsulation of Baker’s Yeast in Gellan Gum Beads Used in Repeated Cycles of Glucose Fermentation

    Directory of Open Access Journals (Sweden)

    Camelia Elena Iurciuc (Tincu

    2017-01-01

    Full Text Available The purpose of this work is to prepare ionically cross-linked (with CaCl2 gellan particles with immobilized yeast cells for their use in repeated fermentation cycles of glucose. The study investigates the influence of ionic cross-linker concentration on the stability and physical properties of the particles obtained before extrusion and during time in the coagulation bath (the cross-linker solution with different CaCl2 concentrations. It was found that by increasing the amount of the cross-linker the degree of cross-linking in the spherical gellan matrix increases, having a direct influence on the particle morphology and swelling degree in water. These characteristics were found to be very important for diffusion of substrate, that is, the glucose, into the yeast immobilized cells and for the biocatalytic activity of the yeast immobilized cells in gellan particles. These results highlight the potential of these bioreactors to be used in repeated fermentation cycles (minimum 10 without reducing their biocatalytic activity and maintaining their productivity at similar parameters to those obtained in the free yeast fermentation. Encapsulation of Saccharomyces cerevisiae into the gellan gum beads plays a role in the effective application of immobilized yeast for the fermentation process.

  14. The reproductive cycle of the humbug damselfish Dascyllus aruanus according to the changes in lunar phase in micronesia

    Science.gov (United States)

    Choi, Ji Yong; Kim, Na Na; Lee, Dae-Won; Choi, Young-Ung; Choi, Cheol Young

    2017-06-01

    The moon is known to be an environmental factor that controls the reproductive cycle of fish, and fish have evolved a variety of reproduction patterns depending on the lunar phase. In this study, we examined the relationship between lunar phases and the reproductive cycle of the humbug damselfish Dascyllus aruanus inhabiting Weno Island, Chuuk Lagoon, Micronesia. We divided the one-month lunar cycle into eight phases, and measured the features of moonlight (peak wavelength and intensity) and indicators of fish maturity [gonadosomatic index (GSI) and sex hormones] in relation to the eight lunar phases. In addition, we investigated the daily rhythms of sex hormones in fish ovaries during the full moon phase. The results showed that the peak wavelength of moonlight was 430 nm (blue wavelength region) regardless of the lunar phase, and that moonlight intensity was highest during a full moon at 02:00. Furthermore, the GSI and sex hormones were both higher around the full moon phase. These findings support the hypothesis that humbug damselfish spawn once a month and that this event occurs at full moon, which is the phase of the moon with the strongest intensity. Based on these findings, we predict that blue wavelength, the dominant wavelength of moonlight, is one of the environmental factors influencing the monthly spawning of D. aruanus.

  15. Estradiol-17beta and testosterone concentrations in male and female Mya arenaria (Mollusca bivalvia) during the reproductive cycle.

    Science.gov (United States)

    Gauthier-Clerc, S; Pellerin, J; Amiard, J C

    2006-01-15

    Perturbation of the reproductive cycle as well as vitellin-like protein synthesis have already been reported in Mya arenaria sampled in contaminated areas of the St. Lawrence maritime estuary (Québec, Canada). To assess the potential role of endocrine disruptors in modulating the reproductive cycle in clams, the role of sex steroids has to be clarified. We determined the levels of estradiol-17beta and testosterone during the reproductive cycle in female and male M. arenaria. Both steroids were measured by ELISA in the gonads and no differences in steroid profiles appeared between sexes. Estrogen levels varied between 150 and 400 pg g(-1) wet weight over gametogenesis and were near 10 times higher than testosterone levels. Results showed transient increases of both steroids at the onset of vitellogenesis in females and during the spawning stage in both sexes. These findings indicate that these hormones could have a role as endogenous modulators of gametogenesis. Further studies are, however, needed to describe the pathway of steroid synthesis in clam gonad and elucidate steroid involvement in controlling gametogenesis and as well as their relationship with neurohormones since these latter are required to promote sexual maturation.

  16. Endurance, aerobic high-intensity, and repeated sprint cycling performance is unaffected by normobaric "Live High-Train Low"

    DEFF Research Database (Denmark)

    Bejder, Jacob; Andersen, Andreas Breenfeldt; Buchardt, Rie

    2017-01-01

    The aim was to investigate whether 6 weeks of normobaric "Live High-Train Low" (LHTL) using altitude tents affect highly trained athletes incremental peak power, 26-km time-trial cycling performance, 3-min all-out performance, and 30-s repeated sprint ability. In a double-blinded, placebo...... conducted in a double-blinded, placebo-controlled cross-over design do not affect power output during an incremental test, a ~26-km time-trial test, or 3-min all-out exercise in highly trained triathletes. Furthermore, 30 s of repeated sprint ability was unaltered.......-out exercise, and 8 × 30 s of all-out sprint was evaluated before and after the intervention. Following at least 8 weeks of wash-out, the subjects crossed over and repeated the procedure. Incremental peak power output was similar after both interventions [LHTL: 375 ± 74 vs. 369 ± 70 W (pre-vs-post), placebo...

  17. Development of QSAR models using artificial neural network analysis for risk assessment of repeated-dose, reproductive, and developmental toxicities of cosmetic ingredients.

    Science.gov (United States)

    Hisaki, Tomoka; Aiba Née Kaneko, Maki; Yamaguchi, Masahiko; Sasa, Hitoshi; Kouzuki, Hirokazu

    2015-04-01

    Use of laboratory animals for systemic toxicity testing is subject to strong ethical and regulatory constraints, but few alternatives are yet available. One possible approach to predict systemic toxicity of chemicals in the absence of experimental data is quantitative structure-activity relationship (QSAR) analysis. Here, we present QSAR models for prediction of maximum "no observed effect level" (NOEL) for repeated-dose, developmental and reproductive toxicities. NOEL values of 421 chemicals for repeated-dose toxicity, 315 for reproductive toxicity, and 156 for developmental toxicity were collected from Japan Existing Chemical Data Base (JECDB). Descriptors to predict toxicity were selected based on molecular orbital (MO) calculations, and QSAR models employing multiple independent descriptors as the input layer of an artificial neural network (ANN) were constructed to predict NOEL values. Robustness of the models was indicated by the root-mean-square (RMS) errors after 10-fold cross-validation (0.529 for repeated-dose, 0.508 for reproductive, and 0.558 for developmental toxicity). Evaluation of the models in terms of the percentages of predicted NOELs falling within factors of 2, 5 and 10 of the in-vivo-determined NOELs suggested that the model is applicable to both general chemicals and the subset of chemicals listed in International Nomenclature of Cosmetic Ingredients (INCI). Our results indicate that ANN models using in silico parameters have useful predictive performance, and should contribute to integrated risk assessment of systemic toxicity using a weight-of-evidence approach. Availability of predicted NOELs will allow calculation of the margin of safety, as recommended by the Scientific Committee on Consumer Safety (SCCS).

  18. Large scale simulation of NiTi helical spring actuators under repeated thermomechanical cycles

    Science.gov (United States)

    Saleeb, A. F.; Dhakal, B.; Hosseini, M. S.; Padula, S. A., II

    2013-09-01

    As typically utilized in applications, a shape memory alloy (SMA) actuator operates under a large number of thermomechanical cycles, hence the importance of accounting for the cyclic behavior characteristics in modeling and numerical simulation of these actuators. To this end, the present work is focused on the characterization of the cyclic, evolutionary behavior of binary 55NiTi using a newly developed, multi-axial, material-modeling framework and its finite element analysis (FEA) implementation for use in the simulations of SMA actuators. In particular, two different geometric configurations of four- and two-coil helical springs subjected to axial end-forces are investigated under the effect of a large number of thermal cycles leading to the saturated deformation state of the coils. In addition, two different boundary conditions were examined, corresponding to: (a) the loading end cross section assumed to be free-to-twist, and (b) the loading end cross section assumed to be restrained against twist rotation. The study has led to the following five important conclusions: (i) the states of stresses and strains in the coils exhibited marked spatial non-homogeneities, both along the length as well as the cross section of the wires; (ii) the cyclic deformation response of the coils exhibits a similar evolutionary character to that of the 55NiTi material when tested under simple isobaric tensile stress conditions; (iii) the end boundary conditions affect the evolution of the deformation response; (iv) the magnitudes of the evolving nonlinear deformation states (i.e., axial displacements on the martensite and austenite sides, as well as the actuation displacement) were found to be proportional to the number of coils in an essentially linear manner, and (v) the change in coil diameter, while maintaining the pitch height, wire diameter and the number of coils fixed, has a significant effect on the response of the helical spring, both with regard to the resulting stress

  19. Modeling Neurocognitive Decline and Recovery During Repeated Cycles of Extended Sleep and Chronic Sleep Deficiency.

    Science.gov (United States)

    St Hilaire, Melissa A; Rüger, Melanie; Fratelli, Federico; Hull, Joseph T; Phillips, Andrew J K; Lockley, Steven W

    2017-01-01

    Intraindividual night-to-night sleep duration is often insufficient and variable. Here we report the effects of such chronic variable sleep deficiency on neurobehavioral performance and the ability of state-of-the-art models to predict these changes. Eight healthy males (mean age ± SD: 23.9 ± 2.4 years) studied at our inpatient intensive physiologic monitoring unit completed an 11-day protocol with a baseline 10-hour sleep opportunity and three cycles of two 3-hour time-in-bed (TIB) and one 10-hour TIB sleep opportunities. Participants received one of three polychromatic white light interventions (200 lux 4100K, 200 or 400 lux 17000K) for 3.5 hours on the morning following the second 3-hour TIB opportunity each cycle. Neurocognitive performance was assessed using the psychomotor vigilance test (PVT) administered every 1-2 hours. PVT data were compared to predictions of five group-average mathematical models that incorporate chronic sleep loss functions. While PVT performance deteriorated cumulatively following each cycle of two 3-hour sleep opportunities, and improved following each 10-hour sleep opportunity, performance declined cumulatively throughout the protocol at a more accelerated rate than predicted by state-of-the-art group-average mathematical models. Subjective sleepiness did not reflect performance. The light interventions had minimal effect. Despite apparent recovery following each extended sleep opportunity, residual performance impairment remained and deteriorated rapidly when rechallenged with subsequent sleep loss. None of the group-average models were capable of predicting both the build-up in impairment and recovery profile of performance observed at the group or individual level, raising concerns regarding their use in real-world settings to predict performance and improve safety.

  20. Evaluation of resistance development and viability recovery by a non-enveloped virus after repeated cycles of aPDT.

    Science.gov (United States)

    Costa, Liliana; Tomé, João P C; Neves, Maria G P M S; Tomé, Augusto C; Cavaleiro, José A S; Faustino, Maria A F; Cunha, Ângela; Gomes, Newton C M; Almeida, Adelaide

    2011-09-01

    Nowadays, the emergence of drug resistant microorganisms is a public health concern. The antimicrobial photodynamic therapy (aPDT) has an efficient action against a wide range of microorganisms and can be viewed as an alternative approach for treating microbial infections. The aim of this study was to determine if a model target virus (T4-like bacteriophage), in the presence of the tricationic porphyrin 5,10,15-tris(1-methylpyridinium-4-yl)-20-(pentafluorophenyl)porphyrin tri-iodide (Tri-Py(+)-Me-PF), can develop resistance to aPDT and recover its viability after photodynamic treatments. To assess the development of aPDT resistance after repeated treatments, a suspension of T4-like bacteriophage was irradiated with white light (40 Wm(-2)) for 120 min in the presence of 5.0 μM of Tri-Py(+)-Me-PF (99.99% of inactivation) and new phage suspensions were produced from the surviving phages, after each cycle of light exposure. The procedure was repeated ten times. To evaluate the recovery of viral viability after photoinactivation, a suspension of T4-like bacteriophage was irradiated with white light for 120 min in the presence of 5.0 μM of Tri-Py(+)-Me-PF on five consecutive days. In each day, an aliquot of the irradiated suspension was plated and the number of lysis plaques was counted after 24, 48, 72, 96 and 120 h of dark incubation at 37 °C. The profile of bacteriophage photoinactivation did not change after ten consecutive cycles and no recovery of viability was detected after five accumulated cycles of photodynamic treatment. The results suggest that aPDT represents a valuable and promising alternative therapy to treat viral infections, overcoming the problem of microbial resistance. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Effect of Red Bull energy drink on repeated Wingate cycle performance and bench-press muscle endurance.

    Science.gov (United States)

    Forbes, Scott C; Candow, Darren G; Little, Jonathan P; Magnus, Charlene; Chilibeck, Philip D

    2007-10-01

    The purpose of this study was to determine the effects of Red Bull energy drink on Wingate cycle performance and muscle endurance. Healthy young adults (N = 15, 11 men, 4 women, 21 +/- 5 y old) participated in a crossover study in which they were randomized to supplement with Red Bull (2 mg/kg body mass of caffeine) or isoenergetic, isovolumetric, noncaffeinated placebo, separated by 7 d. Muscle endurance (bench press) was assessed by the maximum number of repetitions over 3 sets (separated by 1-min rest intervals) at an intensity corresponding to 70% of baseline 1-repetition maximum. Three 30-s Wingate cycling tests (load = 0.075 kp/kg body mass), with 2 min recovery between tests, were used to assess peak and average power output. Red Bull energy drink significantly increased total bench-press repetitions over 3 sets (Red Bull = 34 +/- 9 vs. placebo = 32 +/- 8, P %%%lt; 0.05) but had no effect on Wingate peak or average power (Red Bull = 701 +/- 124 W vs. placebo = 700 +/- 132 W, Red Bull = 479 +/- 74 W vs. placebo = 471 +/- 74 W, respectively). Red Bull energy drink significantly increased upper body muscle endurance but had no effect on anaerobic peak or average power during repeated Wingate cycling tests in young healthy adults.

  2. Montmorency cherries reduce the oxidative stress and inflammatory responses to repeated days high-intensity stochastic cycling.

    Science.gov (United States)

    Bell, Phillip G; Walshe, Ian H; Davison, Gareth W; Stevenson, Emma; Howatson, Glyn

    2014-02-21

    This investigation examined the impact of Montmorency tart cherry concentrate (MC) on physiological indices of oxidative stress, inflammation and muscle damage across 3 days simulated road cycle racing. Trained cyclists (n = 16) were divided into equal groups and consumed 30 mL of MC or placebo (PLA), twice per day for seven consecutive days. A simulated, high-intensity, stochastic road cycling trial, lasting 109 min, was completed on days 5, 6 and 7. Oxidative stress and inflammation were measured from blood samples collected at baseline and immediately pre- and post-trial on days 5, 6 and 7. Analyses for lipid hydroperoxides (LOOH), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), interleukin-8 (IL-8), interleukin-1-beta (IL-1-β), high-sensitivity C-reactive protein (hsCRP) and creatine kinase (CK) were conducted. LOOH (p < 0.01), IL-6 (p < 0.05) and hsCRP (p < 0.05) responses to trials were lower in the MC group versus PLA. No group or interaction effects were found for the other markers. The attenuated oxidative and inflammatory responses suggest MC may be efficacious in combating post-exercise oxidative and inflammatory cascades that can contribute to cellular disruption. Additionally, we demonstrate direct application for MC in repeated days cycling and conceivably other sporting scenario's where back-to-back performances are required.

  3. Montmorency Cherries Reduce the Oxidative Stress and Inflammatory Responses to Repeated Days High-Intensity Stochastic Cycling

    Directory of Open Access Journals (Sweden)

    Phillip G. Bell

    2014-02-01

    Full Text Available This investigation examined the impact of Montmorency tart cherry concentrate (MC on physiological indices of oxidative stress, inflammation and muscle damage across 3 days simulated road cycle racing. Trained cyclists (n = 16 were divided into equal groups and consumed 30 mL of MC or placebo (PLA, twice per day for seven consecutive days. A simulated, high-intensity, stochastic road cycling trial, lasting 109 min, was completed on days 5, 6 and 7. Oxidative stress and inflammation were measured from blood samples collected at baseline and immediately pre- and post-trial on days 5, 6 and 7. Analyses for lipid hydroperoxides (LOOH, interleukin-6 (IL-6, tumor necrosis factor-alpha (TNF-α, interleukin-8 (IL-8, interleukin-1-beta (IL-1-β, high-sensitivity C-reactive protein (hsCRP and creatine kinase (CK were conducted. LOOH (p < 0.01, IL-6 (p < 0.05 and hsCRP (p < 0.05 responses to trials were lower in the MC group versus PLA. No group or interaction effects were found for the other markers. The attenuated oxidative and inflammatory responses suggest MC may be efficacious in combating post-exercise oxidative and inflammatory cascades that can contribute to cellular disruption. Additionally, we demonstrate direct application for MC in repeated days cycling and conceivably other sporting scenario’s where back-to-back performances are required.

  4. Blood haematological and biochemical parameters in normal cycling, pregnant and repeat breeding buffaloes (Bubalus bubalis) maintained in isothermic and isonutritional conditions

    Institute of Scientific and Technical Information of China (English)

    Anthony Sabasthin; Venkataswamy Girish Kumar; Sumanta Nandi

    2012-01-01

    Objective:The present study was envisaged to examine the hematological and biochemical, parameters in three different groups of buffaloes (regularly cycling, pregnant and repeat breeding) maintained in isothermic and isonutritional conditions to establish the variations in blood and/or serum components in these groups.Methods:Blood samples were analyzed for hemoglobin, PCV, TLC, neutophil, lymphocyte, eosinophil, and monocyte count, glucose, total protein, albumin, globulin, urea and cholesterol.Results:The results revealed significantly lower haemoglobin and packed cell volume value in repeat breeding when compared to pregnant and regularly cycling animals. The WBC value significantly higher in repeat breeding when compared to regularly cycling animals. The average mean values of neutrophils, lymphocyte and eosinophils revealed a no significant difference in the neutrophils, lymphocyte and eosinophils in between the group. The mean values of monocytes revealed a significantly higher value in repeat breeding animals when compared to pregnant animals. The serum glucose, total protein, cholesterol and urea levels were significantly lower in repeat breeding compared to pregnant and regularly cycling animals. The levels of albumin and globulin revealed non-significant difference among the groups.Conclusions: A significant decrease in the hemoglobin, PCV, glucose, total protein, cholesterol and urea was observed in the repeat breeding animals when compared to pregnant and regularly cycling animals.

  5. Comparison of reproductive outcome, including the pattern of loss, between couples with chromosomal abnormalities and those with unexplained repeated miscarriages.

    Science.gov (United States)

    Flynn, Helen; Yan, Junhao; Saravelos, Sotirios H; Li, Tin-Chiu

    2014-01-01

    Chromosomal abnormalities are an important cause of repeated miscarriage. Several studies have discussed the association between chromosomal abnormalities and repeated miscarriage. This study attempts to describe the pattern of miscarriage in this group of women and the eventual pregnancy outcome of couples with chromosomal abnormalities compared with couples with unexplained repeated pregnancy loss. This was a retrospective study involving 795 couples with repeated miscarriages. Out of 795 couples, 28 (3.52%) were found to have a chromosomal abnormality (carrier group). Over half (65.5%) of the chromosomal abnormalities were balanced reciprocal translocations. After referral, this carrier group had a total of 159 pregnancies, leading to 36 live births (22.6%) among 18 couples. The after referral miscarriage rate in the chromosomal anomaly group (55.6%) was significantly (P chromosomal anomaly, the miscarriages were more likely to occur between 6 and 12 weeks' gestation. The encouraging cumulative live birth rate of 64.3% for couples with chromosomal anomaly and repeated miscarriage suggests that further attempts at natural conception are a viable option. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.

  6. Ovarian changes during the reproductive cycle of the Tupinambis merianae lizard raised in a temperate environment

    Directory of Open Access Journals (Sweden)

    Manes, Mario E.

    2007-03-01

    Full Text Available El ciclo reproductor de hembras de Tupinambis merianae criadas en ambiente templado consiste de tres fases gonadales: previtelogénica, vitelogénica y postovulatoria o lútea. Durante la fase previtelogénica, que ocupa gran parte del verano, el otoño e invierno, los ovarios son pequeños, pesan menos de 4 g y contienen solamente folículos no vitelogénicos, los cuales se desarrollan lentamente a partir de los nidos germinales, alcanzando unos 5 mm de diámetro. Debido a una maduración gonadal asincrónica entre ambos sexos, las cópulas acontecen cuando los ovarios son aún previtelogénicos. Luego sobreviene una corta e intensa vitelogénesis, durante la cual los folículos crecen uniformemente incrementando unas 6 veces su diámetro (cerca de 30 mm, mientras que la masa ovárica total alcanza unos 400 g. El proceso culmina entre los 15 y 20 días, con una ovulación generalizada y la subsiguiente oviposición. Como consecuencia, los ovarios postovulatorios aparecen reducidos a unos 5 g, con una superficie casi enteramente cubierta de cicatrices foliculares, las cuales pronto desarrollan cuerpos lúteos. La detención del ciclo ovárico, con atresia folicular previtelogénica masiva, como resultado del aislamiento de las hembras, permite concluir sobre la existencia de estímulos sexuales promotores de la vitelogénesis. The reproductive cycle of Tupinambis merianae females raised in a temperate environment consists of three gonadal phases: previtellogenic, vitellogenic and postovulatory or luteal phases. During the previtellogenic phase, which takes great part of the summer, autumn and winter, the ovaries are small, weigh less than 4 g, and contain only nonvitellogenic follicles, which develop slowly from germinal beds, until they are almost 5 mm diameter. Due to an asynchronous gonadal maturation in both sexes, matings occur when ovaries are still previtellogenic. Then comes a short and intense vitellogenesis, during which follicles grow

  7. Are repeated assisted reproductive technology treatments and an unsuccessful outcome risk factors for unipolar depression in infertile women?

    DEFF Research Database (Denmark)

    Sejbaek, Camilla S; Pinborg, Anja; Hageman, Ida

    2015-01-01

    INTRODUCTION: Previous studies have shown conflicting results whether unsuccessful medically assisted reproduction is a risk factor for depression among women. This study therefore investigated if women with no live birth after assisted reproductive technology (ART) treatment had a higher risk...... of unipolar depression compared with women with a live birth after ART treatment. MATERIAL AND METHODS: The Danish National ART-Couple (DANAC) Cohort is a national register-based cohort study that consists of women who received ART treatment from 1 January 1994 to 30 September 2009, in Denmark (n = 41 050......). Information on unipolar depression was obtained from the Danish Psychiatric Central Research Register. The analyses were conducted in Cox regression analysis. RESULTS: During the 308 494 person-years of follow up, 552 women were diagnosed with unipolar depression. A Cox proportional hazards model showed...

  8. Effects of two different half-squat training programs on fatigue during repeated cycling sprints in soccer players.

    Science.gov (United States)

    Bogdanis, Gregory C; Papaspyrou, Aggeliki; Souglis, Athanasios G; Theos, Apostolos; Sotiropoulos, Aristomenis; Maridaki, Maria

    2011-07-01

    This study compared the effects of two different half-squat training programs on the repeated-sprint ability of soccer players during the preseason. Twenty male professional soccer players were divided into 2 groups: One group (S-group) performed 4 sets of 5 repetitions with 90% of their 1-repetition maximum (1RM), and the other group (H-group) performed 4 sets of 12 repetitions with 70% of 1RM, 3 times per week for 6 weeks, in addition to their common preseason training program. Repeated-sprint ability was assessed before and after training by 10 × 6-second cycle ergometer sprints separated by 24 seconds of passive recovery. Maximal half-squat strength increased significantly in both groups (p < 0.01), but this increase was significantly greater in the S-group compared with the H-group (17.3 ± 1.9 vs. 11.0 ± 1.9%, p < 0.05). Lean leg volume (LLV) increased only in the H-group. Total work over the 10 sprints improved in both groups after training, but this increase was significantly greater in the second half (8.9 ± 2.6%) compared with the first half of the sprint test (3.2 ± 1.7%) only in the S-group. Mean power output (MPO) expressed per liter of LLV was better maintained during the last 6 sprints posttraining only in the S-group, whereas there was no change in MPO per LLV in the H-group over the 10 sprints. These results suggest that resistance training with high loads is superior to a moderate-load program, because it increases strength without a change in muscle mass and also results in a greater improvement in repeated sprint ability. Therefore, resistance training with high loads may be preferable when the aim is to improve maximal strength and fatigue during sprinting in professional soccer players.

  9. AN INVESTIGATION ON THE REGULARITY OF CERVICAL MUCUS PEROXIDASE (CMPx) ACTIVITY IN REPRODUCTIVE CYCLES

    Institute of Scientific and Technical Information of China (English)

    WANGHong; CAOZuan-Sun; WENGQi-Liang; MAOWen-Jun

    1989-01-01

    29 infertile women with normal menstrual cycles, aged 23-33, were closely observed for 30 cycles. Blood aamples and cervical mucus in follicular, periovulatory and mid lutcul phases were collected respectively for LH, E2 , P and CMPx activity measurement.B-ultrasnographic monitoring was applied during menstrual cycles. Modified Insler score

  10. Disparate effects of constant and annually-cycling daylength and water temperature on reproductive maturation of striped bass (Morone saxatilis)

    Science.gov (United States)

    Clark, R.W.; Henderson-Arzapalo, A.; Sullivan, C.V.

    2005-01-01

    Adult striped bass (Morone saxatilis) were exposed to various combinations of constant or anually-cycling daylength and water temperature. Constant conditions (15 h days, 18??C) were those normally experienced at spawning and cycling conditions simulated natural changes at Chesapeake Bay latitude. Females exposed to constant long (15 h) days and cycling water temperature (TEMPERATURE group) had blood plasma levels of sex steroids (testosterone [T] and estradiol-17?? [E2]) and vitellogenin (Vg), and profiles of oocyte growth, that were nearly identical to those of females held under a natural photothermal cycle (CONTROL group). Several fish from these two groups were induced to spawn fertile eggs. Females constantly exposed to warm water (18??C), with or without a natural photoperiod cycle (PHOTOPERIOD and STATIC groups, respectively), had diminished circulating levels of gonadal steroid hormones and Vg, impaired deposition of yolk granules in their ooplasm, and decreased oocyte growth, and they underwent premature ovarian atresia. Males exposed to cycling water temperature (CONTROL and TEMPERATURE groups) spermiated synchronously during the natural breeding season, at which time they also had had high plasma androgen (T and 11-ketotestosterone [11-KT]) levels. The timing of spermiation was highly asynchronous among males in groups of fish held constantly at 18??C (STATIC and PHOTOPERIOD groups) and this asynchrony was associated with diminished plasma androgen levels. Termination of spermiation by males exposed to cycling water temperature coincided with a sharp decline in levels of plasma androgens about a month after water temperature rose above 18??C. In contrast, most males held constantly at 18??C sustained intermediate levels of plasma androgens and spermiated until the end of the study in late July. The annual cycle of water temperature clearly plays a prominent role in the initiation, maintenance, and termination of the striped bass reproductive cycle. In

  11. The differential effect of metabolic alkalosis on maximum force and rate of force development during repeated, high-intensity cycling.

    Science.gov (United States)

    Siegler, Jason C; Marshall, Paul W M; Raftry, Sean; Brooks, Cristy; Dowswell, Ben; Romero, Rick; Green, Simon

    2013-12-01

    The purpose of this investigation was to assess the influence of sodium bicarbonate supplementation on maximal force production, rate of force development (RFD), and muscle recruitment during repeated bouts of high-intensity cycling. Ten male and female (n = 10) subjects completed two fixed-cadence, high-intensity cycling trials. Each trial consisted of a series of 30-s efforts at 120% peak power output (maximum graded test) that were interspersed with 30-s recovery periods until task failure. Prior to each trial, subjects consumed 0.3 g/kg sodium bicarbonate (ALK) or placebo (PLA). Maximal voluntary contractions were performed immediately after each 30-s effort. Maximal force (F max) was calculated as the greatest force recorded over a 25-ms period throughout the entire contraction duration while maximal RFD (RFD max) was calculated as the greatest 10-ms average slope throughout that same contraction. F max declined similarly in both the ALK and PLA conditions, with baseline values (ALK: 1,226 ± 393 N; PLA: 1,222 ± 369 N) declining nearly 295 ± 54 N [95% confidence interval (CI) = 84-508 N; P force vs. maximum rate of force development during a whole body fatiguing task.

  12. Effects of heat exposure and 3% dehydration achieved via hot water immersion on repeated cycle sprint performance.

    Science.gov (United States)

    Kraft, Justin A; Green, James M; Bishop, Phillip A; Richardson, Mark T; Neggers, Yasmin H; Leeper, James D

    2011-03-01

    This study examined effects of heat exposure with and without dehydration on repeated anaerobic cycling. Males (n = 10) completed 3 trials: control (CT), water-bath heat exposure (∼39°C) to 3% dehydration (with fluid replacement) (HE), and similar heat exposure to 3% dehydration (DEHY). Hematocrit increased significantly from pre to postheat immersion in both HE and DEHY. Participants performed 6 × 15s cycle sprints (30s active recovery). Mean Power (MP) was significantly lower vs. CT (596 ± 66 W) for DEHY (569 ± 72 W), and the difference approached significance for HE (582 ± 76 W, p = 0.07). Peak Power (PP) was significantly lower vs. CT (900 ± 117 W) for HE (870 ± 128 W) and approached significance for DEHY (857 ± 145 W, p = 0.07). Postsprint ratings of perceived exertion was higher during DEHY (6.4 ± 2.0) and HE (6.3 ± 1.6) than CT (5.7 ± 2.1). Combined heat and dehydration impaired MP and PP (decrements greatest in later bouts) with HE performance intermediate to CT and DEHY.

  13. Plasma Ghrelin Concentrations Were Altered with Oestrous Cycle Stage and Increasing Age in Reproductively Competent Wistar Females

    Science.gov (United States)

    Saffrey, M. Jill; Taylor, Victoria J.

    2016-01-01

    Changes in appetite occur during the ovarian cycle in female mammals. Research on appetite-regulatory gastrointestinal peptides in females is limited, because reproductive changes in steroid hormones present additional experimental factors to control for. This study aimed to explore possible changes in the orexigenic (appetite-stimulating) gastrointestinal peptide hormone ghrelin during the rodent oestrous cycle. Fed and fasted plasma and stomach tissue samples were taken from female Wistar rats (32–44 weeks of age) at each stage of the oestrous cycle for total ghrelin quantification using radioimmunoassay. Sampling occurred during the dark phase when most eating takes place in rats. Statistical analysis was by paired-samples t-test, one-way ANOVA on normally distributed data, with Tukey post-hoc tests, or Kruskal-Wallis if not. GLM univariate analysis was used to assess main effects and interactions in ghrelin concentrations in the fed or fasted state and during different stages of the ovarian cycle, with age as a covariate. No consistent fed to fasted ghrelin increases were measured in matched plasma samples from the same animals, contrary to expectations. Total ghrelin concentrations did not significantly change between cycle stages with ANOVA, in either fed or fasted plasma or in stomach tissue. This was despite significantly decreased fasted stomach contents at oestrus (P = 0.028), suggesting decreased food intake. There was however a significant interaction in ghrelin plasma concentrations between fed and fasted proestrus rats and a direct effect of age with rats over 37 weeks old having lower circulating concentrations of ghrelin in both fed and fasted states. The biological implications of altered ghrelin plasma concentrations from 37 weeks of age are as yet unknown, but warrant further investigation. Exploring peripheral ghrelin regulatory factor changes with increasing age in reproductively competent females may bring to light potential effects on

  14. Repeated use of the GnRH analogue deslorelin to down-regulate reproduction in male cheetahs (Acinonyx jubatus).

    Science.gov (United States)

    Bertschinger, H J; Jago, M; Nöthling, J O; Human, A

    2006-10-01

    The GnRH analogue deslorelin, as a subcutaneous implant, was initially developed in Australia as an ovulation-inducing agent in mares. Its uses, for the suppression of reproduction in the domestic dog and cat and in other species, including humans, have been developed subsequently. Such implants have been used as a contraceptive modality in a variety of wild carnivores, both males and females. This paper describes the use of deslorelin implants as a contraceptive agent for cheetah males maintained in a semi-captive environment and housed in various camps together with females. Annually, male cheetahs were treated for 1 (n = 2), 2 (n = 7), 3 (n = 9), 4 (n = 3) or 5 (n = 1) consecutive years with an implant containing 4.7, 5.0 or 6.0 mg of deslorelin. On the first day of treatment and then on an annual basis, blood testosterone concentrations were analysed, testicular measurements were taken, appearance of penile spikes was determined, and semen was collected and evaluated. Pregnancy rates of mated or inseminated females were determined. A dose of 6 mg of deslorelin suppressed reproduction for at least 1 year, whereas with 4.7 and 5 mg of deslorelin, 3 of 17 males had a few non-motile spermatozoa in their ejaculates. All testosterone concentrations were basal at 1 year post-implant and no side effects were observed. We concluded that deslorelin implantation, at a dose of 6 mg, was a safe and reliable method of annual contraception in male cheetahs.

  15. Superovulation at a specific stage of the estrous cycle determines the reproductive performance in mice.

    Science.gov (United States)

    Inyawilert, Wilasinee; Liao, Yu-Jing; Tang, Pin-Chi

    2016-12-01

    Inconsistent reproductive performance has been reported in superovulated mice. Hence, the aim of this study was to analyze the effect and possible mechanism of superovulation timing on mouse reproductive performance. The results showed that mice superovulated at the metestrous (23.08±6.08%) and diestrous stages (33.33±11.45%) presented significantly lower pregnancy rates compared with those superovulated at the estrous stage (66.67±9.20%). After superovulation at the proestrous and estrous stages, mucin 1 (MUC1) and let-7a/let-7b microRNA (miRNA) expression levels were significantly attenuated and enhanced on embryonic day 3.5 (E3.5), respectively, whereas no significant differences in the expression level were found in mice superovulated at the other two stages. A higher number of developing and Graafian follicles was observed in the ovarian sections 48h after the administration of pregnant mare serum gonadotropin (PMSG) at the proestrous and estrous stages. The sections from mice treated at the metestrous and diestrous stages, however, presented more corpora lutea. Therefore, mice superovulated at the proestrous and estrous stages exhibited the best pregnancy rates. Furthermore, the disordered expression of MUC1 and let-7a/let-7b miRNA in mice superovulated at the metestrous and diestrous stages may impair reproduction performance. Copyright © 2016 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  16. Cloning and expression of follistatin gene in half-smooth tongue sole Cynoglossus semilaevis during the reproduction cycle

    Science.gov (United States)

    Wen, Haishen; Si, Yufeng; Zhang, Yuanqing; He, Feng; Li, Jifang

    2015-03-01

    Follistatin (FST) is a monomeric glycoprotein highly enriched in cysteines and belongs to TGF-β superfamily. FST can suppress the secretion of follicle-stimulating hormone and plays a vital role in the reproduction of vertebrates. We used rapid amplification of cDNA ends technology to clone the FST gene of half-smooth tongue sole, Cynoglossus semilaevis. We characterized its phylogenetic context and expression patterns to elucidate its function in the breeding season. The full-length sequence of FST is 1 455 bp and encodes a protein of 321 amino acids. We investigated the expression pattern of FST in C. semilaevis at different stages of reproduction using reverse transcription-polymerase chain reaction (RTPCR). FST mRNA was expressed in all 13 tissues analyzed, and was expressed at high levels in gonad and at slightly lower levels in gill and brain. During the reproductive cycle of C. semilaevis, the transcript level of FST was the highest in the perinucleolus stage, decreased in the primary yolk stage, slightly increased in the tertiary yolk stage, and then reduced to a minimal level in the atretic follicles stage of the ovary. We concluded that FST suppressed follicle-stimulating hormone, which stimulated oocyte development. However, no significant variation was observed across all stages of testis development, although the expression level in the spermatogenesis stage was relatively low, which may result from the regulation of FST by aromatase.

  17. Reproductive cycle of Tagelus plebeius (Mollusca: Bivalvia in the estuary of the Cachoeira River, Ilhéus, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    LO. Ceuta

    Full Text Available This study characterized the reproductive cycle of the stout razor clam Tagelus plebeius in the estuary of the Cachoeira River, Ilhéus, Bahia, northeastern Brazil. Samples of 20 animals per collection were taken biweekly from August 2005 to August 2006. The 480 specimens were measured on the antero-posterior axis (length and then removed from the shell. After macroscopic analysis, the gonads were fixed in Davidson's solution, processed by routine histology and stained by Harris hematoxylin and eosin. The gonads of both males and females appeared milky white, without sexual dimorphism. Microscopic analyses indicated a M: F ratio of 1.06: 1 and continuous reproduction of T. plebeius in the region. The period from August to October showed the most intense spawning. This study provides another example of continuous reproduction of bivalves in tropical waters, and because this species is a heavily exploited fishery resource in the region, it draws attention to the need for a management plan aimed at reducing harvests.

  18. Reproductive cycle of Tagelus plebeius (Mollusca: Bivalvia) in the estuary of the Cachoeira River, Ilhéus, Bahia, Brazil.

    Science.gov (United States)

    Ceuta, L O; Boehs, G

    2012-08-01

    This study characterized the reproductive cycle of the stout razor clam Tagelus plebeius in the estuary of the Cachoeira River, Ilhéus, Bahia, northeastern Brazil. Samples of 20 animals per collection were taken biweekly from August 2005 to August 2006. The 480 specimens were measured on the antero-posterior axis (length) and then removed from the shell. After macroscopic analysis, the gonads were fixed in Davidson's solution, processed by routine histology and stained by Harris hematoxylin and eosin. The gonads of both males and females appeared milky white, without sexual dimorphism. Microscopic analyses indicated a M: F ratio of 1.06: 1 and continuous reproduction of T. plebeius in the region. The period from August to October showed the most intense spawning. This study provides another example of continuous reproduction of bivalves in tropical waters, and because this species is a heavily exploited fishery resource in the region, it draws attention to the need for a management plan aimed at reducing harvests.

  19. Effect of sera of normal cycling, pregnant and repeat breeding buffaloes (Bubalus bubalis) on in vitro maturation of buffalo, sheep and goat oocytes

    Institute of Scientific and Technical Information of China (English)

    Anthony Sabasthin; Sumanta Nandi; Venkataswamy Girish Kumar

    2013-01-01

    Objective: To examine the oocytes maturation capacity of buffalo, sheep and goat using media containing sera of three different groups of buffaloes (regularly cycling, pregnant and repeat breeding). Methods: The buffalo, sheep and goat oocytes were matured under suitable conditions in medium containing sera of regularly cycling, pregnant and repeat breeding buffaloes. Results:The oocytes maturation rate containing buffalo oocytes cultured in media containing sera of the control group and regularly cycling group were not significantly different. However when oocytes cultured in the media containing sera of pregnant buffaloes the maturation rate were significantly declined. Further significant declined in maturation rate were observed when oocytes cultured in media containing sera of repeat breeding buffaloes. When sheep and goat oocytes cultured in the media containing control, pregnant and regularly cycling animals sera the oocytes maturation rate were not significantly different. A significant decline in maturation rate of sheep and goat oocytes were observed, when oocytes cultured in media containing sera of repeat breeding buffaloes. Conclusion: We may conclude that serum collected from normal cycling buffaloes can be used for oocytes maturation in both homogeneous and heterogeneous species.

  20. Repeated-sprint cycling does not induce respiratory muscle fatigue in active adults: measurements from the powerbreathe® inspiratory muscle trainer.

    Science.gov (United States)

    Minahan, Clare; Sheehan, Beth; Doutreband, Rachel; Kirkwood, Tom; Reeves, Daniel; Cross, Troy

    2015-03-01

    This study examined respiratory muscle strength using the POWERbreathe® inspiratory muscle trainer (i.e., 'S-Index') before and after repeated-sprint cycling for comparison with maximal inspiratory pressure (MIP) values obtained during a Mueller maneuver. The S-Index was measured during six trials across two sessions using the POWERbreathe® and MIP was measured during three trials in a single session using a custom-made manometer in seven recreationally active adults. Global respiratory muscle strength was measured using both devices before and after the performance of sixteen, 6-s sprints on a cycle ergometer. Intraclass correlation coefficients for the POWERbreathe® S-index indicated excellent (p Repeated-sprint cycling had no effect on respiratory muscle strength as measured by the POWERbreathe® (p > 0.99) and during the Mueller maneuver (p > 0.99). The POWERbreathe® S-Index is a moderately reliable, but not equivalent, measure of MIP determined during a Mueller maneuver. Furthermore, repeated-sprint cycling does not induce globalized respiratory muscle fatigue in recreationally-active adults. Key pointsThe S-Index as measured by the POWERbreathe® is a reliable measure of respiratory muscle strengthThe S-Index does not accurately reflect maximal inspiratory pressure obtained from a Mueller maneuverRepeated-sprint cycling does not induce respiratory muscle fatigue as measured by the POWERbreathe® and the Manometer.

  1. Life-cycle exposure to microcystin-LR interferes with the reproductive endocrine system of male zebrafish.

    Science.gov (United States)

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

    2016-06-01

    Recently, MC-LR reproductive toxicity drew great attention. Limited information was available on endocrine-disrupting effects of MC-LR on the reproduction system in fish. In the present study, zebrafish hatchlings (5 d post-fertilization) were exposed to 0, 0.3, 3 and 30μg/L MC-LR for 90 d until they reached sexual maturity. Male zebrafish were selected, and changes in growth and developmental parameters, testicular histological structure as well as the levels of gonadal steroid hormones were studied along with the related-gene transcriptional responses in the hypothalamic-pituitary-gonadal axis (HPG-axis). The results, for the first time, show a life cycle exposure to MC-LR causes growth inhibition, testicular damage and delayed sperm maturation. A significant decrease in T/E2 ratio indicated that MC-LR disrupted sex steroid hormones balance. The changes in transcriptional responses of HPG-axis related genes revealed that MC-LR promoted the conversion of T to E2 in circulating blood. It was also noted that vtg1 mRNA expression in the liver was up-regulated, which implied that MC-LR could induce estrogenic-like effects at environmentally relevant concentrations and long-term exposure. Our findings indicated that a life cycle exposure to MC-LR causes endocrine disruption with organic and functional damage of the testis, which might compromise the quality of life for the survivors and pose a potent threat on fish reproduction and thus population dynamics in MCs-contaminated aquatic environments.

  2. Menstrual cycle influence on cognitive function and emotion processing - from the reproductive perspective

    Directory of Open Access Journals (Sweden)

    Inger Sundström Sundström Poromaa

    2014-11-01

    Full Text Available The menstrual cycle has attracted research interest ever since the 1930s. For many researchers the menstrual cycle is an excellent model of ovarian steroid influence on emotion, behavior, and cognition. Over the past years methodological improvements in menstrual cycle studies have been noted, and this review summarizes the findings of methodologically sound menstrual cycle studies in healthy women. Whereas the predominant hypotheses of the cognitive field state that sexually dimorphic cognitive skills that favor men are improved during menstrual cycle phases with low estrogen and that cognitive skills that favor women are improved during cycle phases with increased estrogen and/or progesterone, this review has not found sufficient evidence to support any of these hypotheses. Mental rotation has gained specific interest in this aspect, but a meta-analysis yielded a standardized mean difference in error rate of 1.61 (95% CI -0.35 – 3.57, suggesting, at present, no favor of an early follicular phase improvement in mental rotation performance. Besides the sexually dimorphic cognitive skills, studies exploring menstrual cycle effects on tasks that probe prefrontal cortex function, for instance verbal or spatial working memory, have also been reviewed. While studies thus far are few, results at hand suggest improved performance at times of high estradiol levels. Menstrual cycle studies on emotional processing, on the other hand, tap into the emotional disorders of the luteal phase, and may be of relevance for women with premenstrual disorders. Although evidence at present is limited, it is suggested that emotion recognition, consolidation of emotional memories, and fear extinction is modulated by the menstrual cycle in women. With the use of functional magnetic resonance imaging, several studies report changes in brain reactivity across the menstrual cycle, most notably increased amygdala reactivity in the luteal phase.

  3. Preliminary observations on the reproductive cycle of female Tegu lizards (Tupinambis teguizin)

    OpenAIRE

    Yanosky, Ángel Alberto; Mercolli, Claudia

    1991-01-01

    The black tegu lizard, Tupinambis teguixin (Linnaeus 1758) is a common element in the wild all throughout Southamerica except for Chile. This teiid lizard was outstood by earlier travellers such as Sir Charles Waterton who reported for the first time about the delicate food, resembling chicken flesh and frequently consumed by local natives. Despite its relative abundance and both the intense economical and social importance of tegus, as well as its situation in the food web, the reproductive ...

  4. Sexual reproduction in the Candida clade: cryptic cycles, diverse mechanisms, and alternative functions

    OpenAIRE

    Alby, Kevin; Bennett, Richard J.

    2010-01-01

    To have sex, or not to have sex, is a question posed by many microorganisms. In favor of a sexual lifestyle is the associated rearrangement of genetic material that confers potential fitness advantages, including resistance to antimicrobial agents. The asexual lifestyle also has benefits, as it preserves complex combinations of genes that may be optimal for pathogenesis. For this reason, it was thought that several pathogenic fungi favored strictly asexual modes of reproduction. Recent approa...

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

    Science.gov (United States)

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

    2010-12-01

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

  6. [Polarized light microscopy for evaluation of oocytes as a prognostic factor in the evolution of a cycle in assisted reproduction].

    Science.gov (United States)

    González-Ortega, C; Cancino-Villarreal, P; Alonzo-Torres, V E; Martínez-Robles, I; Pérez-Peña, E; Gutiérrez-Gutiérrez, A M

    2016-04-01

    Identification of the best embryos to transfer is a key element for success in assisted reproduction. In the last decade, several morphological criteria of oocytes and embryos were evaluated with regard to their potential for predicting embryo viability. The introduction of polarization light microscopy systems has allowed the visualization of the meiotic spindle and the different layers of the zona pellucida in human oocytes on the basis of birefringence in a non-destructive way. Conflicting results have been reported regarding the predictive value in ICSI cycles. To assess the predictive ability of meiotic spindle and zona pellucida of human oocytes to implant by polarized microscopy in ICSI cycles. Prospective and observational clinical study. 903 oocytes from 94 ICSI cycles were analyzed with polarized microscopy. Meiotic spindle visualization and zona pellucida birefringence values by polarized microscopy were correlated with ICSI cycles results. Meiotic spindle visualization and birefringence values of zona pellucida decreased in a direct basis with increasing age. In patients aged over the 35 years, the percentage of a visible spindle and mean zona pellucida birefringence was lower than in younger patients. Fertilization rate were higher in oocytes with visible meiotic spindle (81.3% vs. 64%; p Polarized light microscopy improves oocyte selection, which significantly impacts in the development of embryos with greater implantation potential. The use of polarized light microscopy with sperm selection methods, blastocyst culture and deferred embryo transfers will contribute to transfer fewer embryos without diminishing rates of live birth and single embryo transfer will be more feasible.

  7. Patterns of Apoptosis and Proliferation throughout the Biennial Reproductive Cycle of Viviparous Female Typhlonectes compressicauda (Amphibia, Gymnophiona

    Directory of Open Access Journals (Sweden)

    Michel Raquet

    2016-12-01

    Full Text Available Typhlonectes compressicauda is an aquatic gymnophionan amphibian living in South America. Its breeding cycle is linked to seasons, characterized by a regular alternation of rainy and dry seasons. During a complex biennial cycle, the female genital tract undergoes a series of alternations of increasing and decreasing, governed by equilibrium of proliferation and apoptotic phenomena. Immunohistochemical methods were used to visualize cell proliferation with the detection of Ki67 antibody, a protein present in proliferative cells; terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL and Apostain were performed to detect apoptotic cells on sections of ovaries and oviducts. In ovaries, both phenomena affect the germinal nests and follicles according to the cycle period. In the oviduct, the balance was in favor of proliferation during preparation for reproduction, and in favor of apoptosis when genital ducts regress. Apoptosis and proliferation are narrowly implicated in the remodeling of the genital tract and they are accompanied by the differentiation of tissues according to the phase of the breeding cycle. These variations permit the capture of oocytes at ovulation, always at the same period, and the parturition after 6–7 months of gestation, at a period in which the newborns live with their mother, protected in burrows in the mud. During the intervening year of sexual inactivity, the female reconstitutes body reserves.

  8. Circadian rhythms are not involved in the regulation of circannual reproductive cycles in a sub-tropical bird, the spotted munia.

    Science.gov (United States)

    Budki, Puja; Malik, Shalie; Rani, Sangeeta; Kumar, Vinod

    2014-07-15

    Circannual rhythms regulate seasonal reproduction in many vertebrates. The present study investigated whether circannual reproductive phenotypes (rhythms in growth of gonads and molt) were generated independently of the circadian clocks in the subtropical non-photoperiodic spotted munia (Lonchura punctulata). Birds were subjected to light:dark (LD) cycles with identical light but varying dark hours, such that the period of LD cycle (T) equaled 16 h (T16; 12 h L:4 h D), 21 h (T21; 12 h L:9 h D), 24 h (T24; 12 h L:12 h D) and 27 h (T27; 12 h L:15 h D), or to continuous light (LL, 24 h L:0 h D) at ~18°C. During the ~21 month exposure, munia underwent at least two cycles of gonadal development and molt; changes in body mass were not rhythmic. This was similar to the occurrence of annual cycles in reproduction and molt observed in wild birds. A greater asynchrony between circannual cycles of gonad development and molt indicated their independent regulation. Females showed reproductive rhythms with similar circannual periods, whilst in males, circannual periods measured between peak gonadal size were longer in T21 and T24 than in T16 or T27. This suggested a sex-dependent timing of annual reproduction in the spotted munia. Also, food availability periods may not influence the circannual timing of reproduction, as shown by the results on the rhythm in gonadal growth and regression in munia under T-photocycles and LL that provided differential light (feeding) hours. Further, a short-term experiment revealed that activity-rest patterns in munia were synchronized with T-photocycles, but were arrhythmic under LL. We conclude that circadian rhythms are not involved in the timing of the annual reproductive cycle in the spotted munia.

  9. Enhancement and suppression of ultradian and circadian rhythms across the female hamster reproductive cycle.

    Science.gov (United States)

    Prendergast, Brian J; Beery, Annaliese K; Paul, Matthew J; Zucker, Irving

    2012-06-01

    The impact of ovarian hormones on hamster ultradian rhythms (URs) is unknown. We concurrently monitored URs and circadian rhythms (CRs) of home cage locomotor activity during the estrous cycle, pregnancy, and lactation of Syrian hamsters. URs with a mean period of 4-5 h were evident during the dark phase in more than 90% of females on days 1 and 2 of the estrous cycle but were significantly less prevalent on cycle days 3 and 4. The period of the UR did not vary as a function of estrous cycle stage, but at all stages, the UR period was longer in the dark than the light phase. The UR acrophase occurred significantly earlier on cycle day 4 than on days 1 and 2, and UR robustness and amplitude were reduced on days 3 and 4. Robustness, mesor, and amplitude of CRs were greater during cycle days 3 and 4; timing of the CR acrophase was delayed on day 4 relative to all other cycle days. Effects of the estrous cycle on URs were evident only during the dark phase. The proportion of hamsters displaying dark phase URs increased significantly during early and late gestation and decreased during lactation. Pregnancy significantly increased UR complexity, robustness, and amplitude. The emergence of URs over gestation was paralleled by decrements in the robustness and amplitude of CRs, which also were absent in a significant proportion of dams during lactation but re-emerged at weaning of litters. The changing endocrine profile of the estrous cycle, hormonal dynamics of pregnancy and lactation, and nursing demands placed on dams are each associated with alterations in the expression of ultradian and circadian locomotor rhythms. Diminution of CRs and augmentation of URs may afford greater behavioral flexibility during life stages when interactions with mates and offspring are less predictable.

  10. Distinctive adaptive response to repeated exposure to hydrogen peroxide associated with upregulation of DNA repair genes and cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Gloria A. Santa-Gonzalez

    2016-10-01

    Full Text Available Many environmental and physiological stresses are chronic. Thus, cells are constantly exposed to diverse types of genotoxic insults that challenge genome stability, including those that induce oxidative DNA damage. However, most in vitro studies that model cellular response to oxidative stressors employ short exposures and/or acute stress models. In this study, we tested the hypothesis that chronic and repeated exposure to a micromolar concentration of hydrogen peroxide (H2O2 could activate DNA damage responses, resulting in cellular adaptations. For this purpose, we developed an in vitro model in which we incubated mouse myoblast cells with a steady concentration of ~50 μM H2O2 for one hour daily for seven days, followed by a final challenge of a 10 or 20X higher dose of H2O2 (0.5 or 1 mM. We report that intermittent long-term exposure to this oxidative stimulus nearly eliminated cell toxicity and significantly decreased genotoxicity (in particular, a >5-fold decreased in double-strand breaks resulting from subsequent acute exposure to oxidative stress. This protection was associated with cell cycle arrest in G2/M and induction of expression of nine DNA repair genes. Together, this evidence supports an adaptive response to chronic, low-level oxidative stress that results in genomic protection and up-regulated maintenance of cellular homeostasis.

  11. The business cycle and drug use in Australia: evidence from repeated cross-sections of individual level data.

    Science.gov (United States)

    Chalmers, Jenny; Ritter, Alison

    2011-09-01

    This paper examined the implications of the business cycle for cannabis and alcohol use. What little we know about cannabis use suggests that young Americans (teenagers and adults in their early 20s) seem more inclined to use illicit drugs and to use them more frequently with rises in the unemployment rate. In contrast, a more fulsome alcohol literature suggests that participation in drinking is unaffected by the business cycle. Heavy drinkers drink less during economic downturns and their reduced use counteracts the fact that light drinkers might drink a little more. Using individual level data from repeated cross-sections of Australia's National Drug Strategy Household Survey (NDSHS), spanning 1991-2007, this study examined the relationship between cannabis and alcohol use of Australians aged 14-49 years and the unemployment rate and real income per capita, two indicators of the business cycle. Australians in their late 20s, 30s and 40s drink less frequently during economic downturns. If unemployment rate rises are accompanied by falls in income per capita, younger Australians will also drink less frequently. Recent participation in cannabis use (within the last year) increases with falls in income per capita regardless of age, although the increase is less marked for young people (14-24 years). Whereas the participation rate of people aged 25-49 years also falls with rising unemployment rates, the participation of younger people increases. Cannabis users younger than 35 will use more frequently as the unemployment rate rises. In contrast, older Australians will use less frequently. Australia's recent economic slowdown has been characterised by rising unemployment rates without accompanying falls in income per capita. Based on our findings this slowdown should have encouraged young Australians aged 14-24 years to both drink and use cannabis more frequently. The slowdown would have had little impact on the frequency of drinking of older Australians. However it

  12. Molecular basis of photoperiodic control of reproductive cycle in a subtropical songbird, the Indian weaver bird (Ploceus philippinus).

    Science.gov (United States)

    Srivastava, Amrita; Trivedi, Neerja; Malik, Shalie; Rani, Sangeeta; Kumar, Vinod

    2015-09-01

    Less is known about genetic basis of photoperiodic regulation of reproductive cycle in subtropical birds. This study measured the expression levels of DIO2, DIO3, GnRH, and GnIH genes in Indian weaver birds subjected to short days (8h light:16h darkness, 8L:16D) and long days (16L:8D) for 48weeks. Whereas small, reproductively inactive testes were maintained under short days, weaver birds underwent testis recrudescence - regression cycle under long days. Relative expression levels of DIO2, DIO3, GnRH and GnIH genes were quantified by the real-time PCR (qPCR) in hypothalamus of birds (n=4) sampled at the beginning of the experiments, and after 10 and 48weeks of short and long day exposures. These sample times represented photosensitive unstimulated (day 0), and under long days the recrudescence (photostimulated, after 10weeks) and regression (photorefractory, after 48weeks) testicular phases. Birds under short days served as controls. The expression pattern of these genes corresponded with testicular phases. High and low GnRH and DIO2 levels were found in birds with large and small testes, respectively. By-and-large the converse was true for GnIH and DIO3 expression levels. Thus, after 10weeks of exposure, there was a significant difference in the mRNA levels between short and long day birds, with small and large testes, respectively. The results also suggest for a possible rapid switching between DIO2 and DIO3 and GnRH and GnIH expressions during testis maturation - regression cycle in Indian weaver birds.

  13. Menstrual cycle influence on cognitive function and emotion processing—from a reproductive perspective

    Science.gov (United States)

    Sundström Poromaa, Inger; Gingnell, Malin

    2014-01-01

    The menstrual cycle has attracted research interest ever since the 1930s. For many researchers the menstrual cycle is an excellent model of ovarian steroid influence on emotion, behavior, and cognition. Over the past years methodological improvements in menstrual cycle studies have been noted, and this review summarizes the findings of methodologically sound menstrual cycle studies in healthy women. Whereas the predominant hypotheses of the cognitive field state that sexually dimorphic cognitive skills that favor men are improved during menstrual cycle phases with low estrogen and that cognitive skills that favor women are improved during cycle phases with increased estrogen and/or progesterone, this review has not found sufficient evidence to support any of these hypotheses. Mental rotation has gained specific interest in this aspect, but a meta-analysis yielded a standardized mean difference in error rate of 1.61 (95% CI −0.35 to 3.57), suggesting, at present, no favor of an early follicular phase improvement in mental rotation performance. Besides the sexually dimorphic cognitive skills, studies exploring menstrual cycle effects on tasks that probe prefrontal cortex function, for instance verbal or spatial working memory, have also been reviewed. While studies thus far are few, results at hand suggest improved performance at times of high estradiol levels. Menstrual cycle studies on emotional processing, on the other hand, tap into the emotional disorders of the luteal phase, and may be of relevance for women with premenstrual disorders. Although evidence at present is limited, it is suggested that emotion recognition, consolidation of emotional memories, and fear extinction is modulated by the menstrual cycle in women. With the use of functional magnetic resonance imaging, several studies report changes in brain reactivity across the menstrual cycle, most notably increased amygdala reactivity in the luteal phase. Thus, to the extent that behavioral changes

  14. Seasonal morphological and biochemical changes of Dahlgren cells implies a potential role of the caudal neurosecretory system (CNSS) in the reproduction cycle of teleostean fish.

    Science.gov (United States)

    Chen, Heng; Mu, Rui

    2008-03-01

    The purpose of this mini-review is to summarize recent research on the seasonal morphological and biochemical changes of Dahlgren cells in the caudal neurosecretory system (CNSS) of the freshwater teleosts carp Carassius auratus. The quantitative proof for these seasonal changes in the morphology and biochemistry of Dahlgren cells reflects the relationship between the CNSS and the reproduction cycle of fish and implies that the CNSS is probably involved in the reproduction process of fish.

  15. Repeatability of the Major Reproductive Traits in Silver Foxes%银狐主要繁殖性状的重复力分析

    Institute of Scientific and Technical Information of China (English)

    张进红; 杨彩然; 马永兴; 冯敏山; 葛旭升; 安翠花; 刘爱丽

    2011-01-01

    The repeatability of several major reproductive traits in silver foxes was investigated so as to provide practical guidance for genetic selection and improvement. The repeatability was calculated from 627 records of 248 female and 211 records of 51 male silver foxes. The repeatability of litter size at birth or weaning, mating date, and pregnancy duration in female silver fox was 0.114, 0.007, 0.270 and 0.206, respectively. The litter size at birth or weaning and conception rate in the mating female foxes were 0.108, 0.303, and 0.206, respectively. The results implied that major reproductive traits of female foxes, the litter size at birth or weaning and conception rate in the mating female foxes were controlled by non-genetic factors.%通过对银狐主要繁殖性状重复力的估计和分析,为选育和改良银狐提供理论基础.利用具有2次或2次以上产仔记录的248只母银狐627个繁殖成绩和51只公狐211个繁殖成绩记录,估计了银狐主要繁殖性状的重复力.产仔母狐胎平均产仔数、胎平均断奶活仔数、母狐配种日期、母狐妊娠期的重复力分别为0.114、0.007、0.270和0.206,公狐与配母狐平均产仔数、与配母狐平均断奶活仔数、与配母狐受胎率的重复力分别为0.108、0.303和0.206.母银狐繁殖能力和公狐与配母狐的平均产仔数、受胎率等性状主要受非遗传因素所控制.

  16. The repeated drying-wetting and freezing-thawing cycles affect only the active pool of soil organic matter

    Science.gov (United States)

    Semenov, Vyacheslav; Zinyakova, Natalya; Tulina, Anastasiya

    2016-04-01

    The decrease in the content of soil organic carbon, particularly in active form, is one of the major problems of the 21st century, which is closely related to the disturbance of the biogeochemical carbon cycle and to the increase in the emission of carbon dioxide into the atmosphere. The main reasons for the SOM losses are the surplus of the SOM active pool losses due to mineralization, erosion, and infiltration over the input of fresh organic matter to the soil, as well as the changes in the soil conditions and processes due to natural and anthropogenic disturbing impacts. Experiments were carried out with mixed samples from the upper layers of soddy-podzolic soil, gray forest soil, and typical chernozems. Soil samples as controls were incubated after wetting for 150 days. The dynamics and cumulative production of C-CO2 under stable temperature (22°C) and moisture conditions were determined; the initial content of potentially mineralizable organic matter (C0) in the soil at the beginning of the incubation was then calculated to use these data as the control. Other soil samples were exposed in flasks to the following successive treatments: wetting →incubation → freezing → thawing → incubation →drying. Six repeated cycles of disturbing impacts were performed for 140 days of the experiment. After six cycles, the soil samples were incubated under stable temperature and moisture conditions for 150 days. The wetting of dried soils and the thawing of frozen soils are accompanied by the pulsed dynamics of the C-CO2 production with an abrupt increase in the rate of the C-CO2 emission within several days by 2.7-12.4 and 1.6-2.7 times, respectively, compared to the stable incubation conditions. The rate of the C-CO2 production pulses under each subsequent impact decreased compared to the preceding one similarly for all studied soils, which could be due to the depletion in potentially mineralizable soil organic matter (C0). The cumulative extra C-CO2 production by

  17. Melatonin and pineal gland peptides are able to correct the impairment of reproductive cycles in rats.

    Science.gov (United States)

    Arutjunyan, Alexander; Kozina, Ljudmila; Milyutina, Yulia; Korenevsky, Andrew; Stepanov, Michael; Arutyunov, Vladimir

    2012-12-01

    Catecholamines play an important role in the hypothalamic regulation of the synthesis and secretion of gonadotropin- releasing hormone, or gonadoliberin. We have shown that melatonin and the pineal gland peptides (epithalamine and epitalon) exert a correcting influence on the diurnal dynamics of norepinephrine (NE) in the medial preoptic area (MPA) and of dopamine (DA) in the median eminence with arcuate nuclei (ME-Arc) disturbed by single administration of the neurotoxic xenobiotic 1,2-dimethylhydrazine (DMH) in female rats. It has been found that experiments with DMH administration can be used as an animal model of female reproductive system premature aging. The investigation of epithalamine (a polypeptide preparation from the bovine pineal gland) effect on circadian rhythms disturbed by the neurotoxic compound DMH has shown a recovery of the diurnal dynamics of NE in MPA. In addition, NE was found to decrease from 9:30 till 11 o'clock, Circadian Time (CT), which was typical of control animals. Epitalon (Ala-Glu-Asp-Gly) proved to be more effective in ME-Arc. This peptide prevents the xenobiotic caused disturbance of DA diurnal rhythm, keeping this metabolite low at 5 o'clock (CT) with it having increased by 11 o'clock (CT). The data obtained suggest that the pineal gland is important for the circadian signal normalization needed for gonadoliberin surge on the day of proestrus. Melatonin and peptides of the pineal gland can be considered as effective protectors of female reproductive system from xenobiotics and premature aging.

  18. Seasonal variations of gene expression biomarkers in Mytilus galloprovincialis cultured populations: temperature, oxidative stress and reproductive cycle as major modulators.

    Science.gov (United States)

    Jarque, Sergio; Prats, Eva; Olivares, Alba; Casado, Marta; Ramón, Montserrat; Piña, Benjamin

    2014-11-15

    The blue mussel Mytilus galloprovincialis has been used as monitoring organism in many biomonitoring programs because of its broad distribution in South European sea waters and its physiological characteristics. Different pollution-stress biomarkers, including gene expression biomarkers, have been developed to determine its physiological response to the presence of different pollutants. However, the existing information about basal expression profiles is very limited, as very few biomarker-based studies were designed to reflect the natural seasonal variations. In the present study, we analyzed the natural expression patterns of several genes commonly used in biomonitoring, namely ferritin, metallothionein, cytochrome P450, glutathione S-transferase, heat shock protein and the kinase responsive to stress KRS, during an annual life cycle. Analysis of mantle-gonad samples of cultured populations of M. galloprovincialis from the Delta del Ebro (North East Spain) showed natural seasonal variability of these biomarkers, pointing to temperature and oxidative stress as major abiotic modulators. In turn, the reproductive cycle, a process that can be tracked by VCLM7 expression, and known to be influenced by temperature, seems to be the major biotic factor involved in seasonality. Our results illustrate the influence of environmental factors in the physiology of mussels through their annual cycle, a crucial information for the correct interpretation of responses under stress conditions.

  19. Trophic ecology of Lampanyctus crocodilus on north-west Mediterranean Sea slopes in relation to reproductive cycle and environmental variables.

    Science.gov (United States)

    Fanelli, E; Papiol, V; Cartes, J E; Rodriguez-Romeu, O

    2014-06-01

    This study examined the population structure, reproductive cycle and feeding pattern of the lanternfish Lampanyctus crocodilus in the Balearic Basin (north-west Mediterranean Sea) from a depth of 450 to 1800 m and at a seasonal scale. Juveniles were mainly located at shallower depths, but also at deepest stations in autumn, while adults mostly inhabited intermediate depths with their centre of population density (CPD) located at 800-1000 m of depth. The migration of adults to deeper depths was detected in late summer to autumn, probably linked to the occurrence of nepheloid layers at c. 1200 m, which in turn enhances the biomass of the zooplankton prey. The diet was mainly based on euphausiids and mysids, with marked seasonal variations both on the upper (450-800 m) and lower (1000-1800 m), where suprabenthic gammariids and pelagic decapods were also dominant. Stomach fullness increased from winter to autumn on the US, while it had a maximum in spring on the LS, in parallel with high consumption of gelatinous zooplankton, which is probably more available after the phytoplankton bloom in late winter. Reproduction occurred in winter, confirmed by the higher percentage of mature females and high gonadosomatic indices (I(G)) at both depth ranges. Hepatosomatic indices (I(H)) showed an inverse trend to I(G) on the US, except in autumn, and was almost parallel on the LS, probably attributable to the migration of adults, which determined different temporal schemes in energy use and storage for reproduction on the US v. LS. Consistent with the different patterns observed at the two depth ranges, environmental drivers of fullness (i.e. feeding intensity) and I(G) (as a proxy of reproductive cycle) differed on the US and LS. The biomass of mysids and euphausiids was the greatest explanatory variables of fullness on the US and LS, pointing to the increasing feeding intensity when a resource was more available. I(H) also explained fullness, suggesting that greater

  20. Repeated Cycles of Chronic Intermittent Ethanol Exposure Increases Basal Glutamate in the Nucleus Accumbens of Mice without affecting glutamate transport

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    William C. Griffin

    2015-02-01

    Full Text Available Repeated cycles of chronic intermittent ethanol (CIE exposure increase voluntary consumption of ethanol in mice. Previous work has shown that extracellular glutamate in the nucleus accumbens (NAc is significantly elevated in ethanol dependent mice and that pharmacologically manipulating glutamate concentrations in the NAc will alter ethanol drinking, indicating that glutamate homeostasis plays a crucial role in ethanol drinking in this model. The present studies were designed to measure extracellular glutamate at a time point in which mice would ordinarily be allowed voluntary access to ethanol in the CIE model and, additionally, to measure glutamate transport capacity in the NAc at the same time point. Extracellular glutamate was measured using quantitative microdialysis procedures. Glutamate transport capacity was measured under Na+ dependent and Na+ independent conditions to determine whether the function of excitatory amino acid transporters (EAATs; also known as system XAG or of system Xc- (Glial cysteine-glutamate exchanger was influenced by CIE exposure. The results of the quantitative microdialysis experiment confirm increased extracellular glutamate (~2 –fold in the NAc of CIE exposed mice (i.e. ethanol-dependent compared to non-dependent mice in the NAc, consistent with earlier work. However, the increase in extracellular glutamate was not due to altered transporter function in the NAc of ethanol-dependent mice, because neither Na+ dependent nor Na+ independent glutamate transport was significantly altered by CIE exposure. These findings point to the possibility that hyperexcitability of cortical-striatal pathways underlies the increases in extracellular glutamate found in the nucleus accumbens of ethanol-dependent mice.

  1. Breeding cycles and reproductive behaviour in the river blenny Salaria fluviatilis

    NARCIS (Netherlands)

    Lengkeek, W.; Didderen, K.

    2006-01-01

    Female gravidity (assessed according to the roundness of the female's abdomen) in a population of Corsican river blennies Salaria fluviatilis showed a cyclical pattern over the breeding season. Behavioural interactions between males and females matched these cycles. The rate of female visits to male

  2. [Reproductive cycle and index of condition used for Melongena corona (Mollusca: Gastropoda)].

    Science.gov (United States)

    Zetina Zárate, A I; Aldana Aranda, D; Brule, T; Baqueiro Cárdenas, E

    2000-12-01

    Melongena corona bispinosa was studied in Yucatán, México (21 degrees 16' N, 89 degrees 49' W) for a year. Males have reproductive peaks in February and December, and a post-copulation peak in June. Female peaks are in March and May, plus oviposition peaks in April and January. Males and females differ in the mean gonadosom ic index (F=13.79, p<0.05) but not in the dry tissue/shell weight (F=0.0902, p<0.05), dry tissue and total weight (F=0.2466, p<0.05) and dry tissue weight/internal shell volume (F=1.0565, p<0.05).

  3. Diversification and reproductive isolation: cryptic species in the only New World high-duty cycle bat, Pteronotus parnellii

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    Clare Elizabeth L

    2013-01-01

    Full Text Available Abstract Background Molecular techniques are increasingly employed to recognize the presence of cryptic species, even among commonly observed taxa. Previous studies have demonstrated that bats using high-duty cycle echolocation may be more likely to speciate quickly. Pteronotus parnellii is a widespread Neotropical bat and the only New World species to use high-duty cycle echolocation, a trait otherwise restricted to Old World taxa. Here we analyze morphological and acoustic variation and genetic divergence at the mitochondrial COI gene, the 7th intron region of the y-linked Dby gene and the nuclear recombination-activating gene 2, and provide extensive evidence that P. parnellii is actually a cryptic species complex. Results Central American populations form a single species while three additional species exist in northern South America: one in Venezuela, Trinidad and western Guyana and two occupying sympatric ranges in Guyana and Suriname. Reproductive isolation appears nearly complete (only one potential hybrid individual found. The complex likely arose within the last ~6 million years with all taxa diverging quickly within the last ~1-2 million years, following a pattern consistent with the geological history of Central and northern South America. Significant variation in cranial measures and forearm length exists between three of the four groups, although no individual morphological character can discriminate these in the field. Acoustic analysis reveals small differences (5–10 kHz in echolocation calls between allopatric cryptic taxa that are unlikely to provide access to different prey resources but are consistent with divergence by drift in allopatric species or through selection for social recognition. Conclusions This unique approach, considering morphological, acoustic and multi-locus genetic information inherited maternally, paternally and bi-parentally, provides strong support to conclusions about the cessation of gene flow and

  4. [Reproductive cycle of the mangrove oyster Crassostrea rhizophorae (Bivalvia: Ostreidae) in Camamu Bay, Bahia, Brasil].

    Science.gov (United States)

    Lenz, Tiago; Boehs, Guisla

    2011-03-01

    The mangrove oyster Crassostrea rhizophorae is important fishery resource along the entire Brasilian coast with excellent potential for marine culture. The purpose of this paper was to examine the reproductive characteristics of the oyster of the Maraú river estuary in Camamu Bay, Bahia, Brasil. The samples were collected monthly, from September 2006 to August 2007, at two points (I and II) in Camamu Bay. At each site 20 oysters were collected for histological analysis, fixed in Davidson's solution, embedded in paraffin, dehydrated in an ethanol series, sectioned (7 microm thick) and stained with Harris hematoxylin and Eosin (HE). Additionally, 30 oysters were sampled, at each point, for a condition index analysis. The water temperature ranged from 23.5 degrees C to 30 degrees C and the salinity from 15 to 25 ups at Point I (Maraú) and from 25 to 35 at Point II (Tanque Island). The oyster's height ranged from 30 to 92 mm at Point I and from 27 to 102 mm at Point II, with an average of 49.0 mm +/- 9.1 (n = 230) and 49.9 mm +/- 9.9 (n = 237), respectively. Among the sampled oysters at Point I, 59.1% were females, 31.3% males, 1.3% hermaphrodites and 8.2% of the oysters of undetermined sex. At Point II, 66.2% were females, 30.4% males, 0.8% hermaphrodites and 2.5% (n = 237) of undetermined sex. The gonadic stage analysis indicated that the reproduction period of the C. rhizophorae in the Maraú Peninsula was continuous all year, without any regressive phase. The condition index (R) ranged from 8.0% to 17.7%. The peak periods of R coincided with the expressive oyster's percentage in the maturation and liberation gametic stages. The results of these findings will contribute information for the oyster spat collection and to the process installation of the oyster culture in Camamu Bay.

  5. Genes responsible for vaginal extracellular matrix metabolism are modulated by women's reproductive cycle and menopause

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    Oksana Shynlova

    2013-04-01

    Full Text Available Objectives To analyze the expression of genes involved in extracellular matrix (ECM biogenesis and remodeling in vaginal tissue of women with clinically normal pelvic floor support (defined as controls according to the phase of menstrual cycle and postmenopausal women with and without pelvic organ prolapse (POP. Materials and Methods This study examined the expression of matrix metalloproteinases (MMPs, their tissue inhibitors (TIMPs, and the Lysyl oxidase (LOX family genes in the anterior vaginal wall of Caucasian women by real-time RT-PCR. Initially, mRNA expression was assessed in premenopausal controls in the secretory (group 1, n = 10 vs. proliferative (group 2, n = 8 phase of menstrual cycle. In addition, we compared premenopausal controls in the proliferative phase (group 2 vs. postmenopausal controls (group 3, n = 5. Finally, we analyzed postmenopausal controls (group 3 vs. postmenopausal women with advanced POP (group 4, n = 13. Results According to the phase of menstrual cycle, MMP1 was significantly reduced (p = 0.003, whereas the expression of TIMP1 and LOXL4 was significantly up-regulated during proliferative phase (both p < 0.01 when compared to the secretory phase in premenopausal control women. Regarding menopausal status/ageing, all MMPs were down-regulated, while TIMP3, TIMP4 and LOXL2 were significantly up-regulated in postmenopausal control women when compared to premenopausal controls (p = 0.005, p = 0.01 and p < 0.001, correspondingly. TIMP4 and LOXL2 mRNA levels were significantly decreased in postmenopausal POP patients compared to asymptomatic postmenopausal controls (p < 0.01 for both. Conclusions Our results indicate that ovarian cycle and age-related changes influence the expression of genes encoding proteins responsible for ECM metabolism in human vagina. Moreover, POP is associated with alteration in vaginal ECM components after menopause.

  6. Effect of different feeding levels during three short periods of gestation on sow and litter performance over two reproductive cycles.

    Science.gov (United States)

    Ren, P; Yang, X J; Kim, J S; Menon, D; Baidoo, S K

    2017-02-01

    The present study investigated the effects of different feeding levels during 3 short periods of gestation on sow and litter performance and its impact on subsequent reproductive performance. A total of 160 multiparous sows were allotted to 1 of 4 dietary treatments using a randomized complete block design with initial body weight (BW) and backfat (BF) as the blocking criteria. All sows were fed one common corn-soybean meal-based diet with the amount of 1.0×maintenance energy intake (100×BW(0.75)kcalME/d) throughout gestation except 3 periods of 7 d when dietary treatments were imposed on d 27, d 55 and d 83 of gestation. During the 3 short periods, sows were fed 1 of 4 different feeding levels: 0.5, 1.0, 1.5 and 2.0×maintenance energy level (0.5M, 1.0M, 1.5M and 2.0M, respectively). Results showed that both BW gain (16.12, 24.74, 30.62 and 36.71kg, respectively) and BF change (-0.27, 0.99, 1.49 and 2.45mm, respectively) from d 27 to 109 of gestation increased linearly (Pfeeding levels. In contrast, with the rise of gestation feeding levels, lactation BW gain (14.31, 9.84, 7.09 and 3.50kg, respectively) decreased linearly (Pfeed intake during lactation (7.05, 7.00, 6.91 and 6.52kg, respectively) tended to decrease linearly (P=0.09) in response to the increase of gestation feeding levels. Furthermore, piglet birth weights increased linearly (Pfeeding levels, while piglet weaning weights were similar (P>0.10) among treatments. Subsequent reproductive performance was not affected (P>0.10) by feeding levels during the previous reproductive cycle. In conclusion, increasing feeding levels during 3 short periods of gestation increased BW and BF gains during gestation and caused less BW gain and more BF loss during lactation due to the reduction of lactation feed intake in response to increasing gestation feeding levels. Increasing feeding levels during 3 short periods of gestation increased piglet birth weight, but did not affect piglet weaning weight. The feeding

  7. Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats 22). Effects of 2- and 4-week administration of theobromine on the testis.

    Science.gov (United States)

    Funabashi, H; Fujioka, M; Kohchi, M; Tateishi, Y; Matsuoka, N

    2000-10-01

    The effects of theobromine, a xanthine derivative, on the testis were compared between rats dosed for 2 and 4 weeks to determine whether a 2-week dosing period is long enough to detect toxicity. Theobromine was administered orally to male Sprague-Dawley rats at dose levels of 250 and 500 mg/kg for 2 weeks starting at the age of 6 or 8 weeks, and for 4 weeks from the age of 6 weeks. Histopathological examination of reproductive organs revealed toxic findings in the testis at 500 mg/kg after 2 weeks of dosing at both ages, and at 250 and 500 mg/kg after 4 weeks of dosing. The primary findings were degeneration/necrosis and desquamation of spermatids and spermatocytes, vacuolization of seminiferous tubules, and multinucleated giant cell formation. These findings were present mainly in stages I-VI and XII-XIV. From these results, it is concluded that the toxic effects of theobromine on the testis can be detected by repeated dosing for 2 weeks as well as for 4 weeks.

  8. Ultrastructural characteristics of the spermatogenesis during the four phases of the annual reproductive cycle of the black myotis bat, Myotis nigricans (Chiroptera: Vespertilionidae).

    Science.gov (United States)

    Beguelini, Mateus R; Taboga, Sebastião R; Morielle-Versute, Eliana

    2013-10-01

    Myotis nigricans is an endemic species of vespertilionid bat, from the Neotropical region, that resembles temperate zone bats in their reproductive cycle; presenting an annual reproductive cycle with two periods of testicular regression, which are not linked to the apoptotic process and seems to be not directly linked to any seasonal abiotic variation. Thus, this study aimed to ultrastructurally evaluate their reproductive cycle. The process of testicular regression could be divided into four periods: active; regressing; regressed and recrudescence; with all presenting distinct characteristics. The active period was similar to that of other bats, presenting the complete occurrence of spermatogenesis, with three main types of spermatogonia (A(d), A(p), and B) and 12 steps in spermatid differentiation; however, it differed in having the outer dense fibers 1, 5, 6, and 9 larger than the others. These three types of spermatogonia undergo considerable morphologic changes from regressing to the regressed period, and in the recrudescence, they return to the basic morphology, which reactivates spermatogenesis. In conclusion, our study described the process of spermatogenesis, the ultrastructure of the spermatozoa and the distinct morphologic variations in the ultrastructure of the testicular cells of M. nigricans during the four different periods of its annual reproductive cycle.

  9. Appropriate timing of uterine cavity length measurement positively affects assisted reproduction cycle outcome.

    Science.gov (United States)

    Madani, Tahereh; Ashrafi, Mahnaz; Abadi, Akram Bahman; Kiani, Kiandokht

    2009-11-01

    An appropriate and easy embryo transfer has a direct impact on pregnancy rates. Proper evaluation of the uterocervical axis and uterine depth are necessary for suitable embryo transfer. The aim of this study was to assess the appropriate time for cervical axis evaluation and uterine measurement. A total of 124 patients undergoing IVF treatment were included in the study. They were divided equally into two groups. In group I (62 women), uterine cavity depth was measured and the uterocervical axis was determined on day 2 or 3 of the menstrual cycle, and in group II (62 women) at the time of oocyte retrieval. There was a statistically significant difference in clinical pregnancy rates between the two groups (P = 0.006). Thirty-four women became pregnant in group I (64.2%) versus 19 women in group II (35.8%). In conclusion, uterine cavity measurement is necessary for suitable embryo transfer. It seems that the time of measurement significantly affects clinical pregnancy rate in IVF cycles. The best time for uterine measurement is on day 2 or 3 of menstruation.

  10. Characterization and manipulation of reproductive cycles in the jaguar (Panthera onca).

    Science.gov (United States)

    Barnes, Serena A; Andrew Teare, J; Staaden, Sheryl; Metrione, Lara; Penfold, Linda M

    2016-01-01

    Basic reproductive information in female jaguars (Panthera onca) is lacking, thus longitudinal fecal samples from seven females were analyzed via enzyme immunoassay to measure estradiol and progestin metabolites throughout the year. Mean estrus length of 194 estrus periods measured hormonally was 6.5±0.3d, mean peak fecal estradiol concentration was 138.7±5.7ng/g; and in one female, estrus resumption occurred approximately 15d post-partum. Ovulation, as indicted by sustained elevated progestin concentrations (>20d), was successfully induced one time by treatment with exogenous hormones in one female and by physical vaginal stimulation in two females a combined total of three times. Elevated fecal progestin was observed outside exogenous stimulation on five occasions, suggesting ovulation occurred spontaneously. Mean length of physically induced and spontaneous pseudopregnancies was 24.7±4.2d and 29.6±2.6d, respectively, and mean length of pregnancy (n=2) was 98.0±0.0d. Mean peak progestin concentration for spontaneous and induced pseudopregnancies, and pregnancy was 7.4±1.4μg/g, 6.4±1.2μg/g, and 13.7±1.0μg/g, respectively. This data suggests jaguars are polyestrous and generally induced ovulators, with a moderate incidence of spontaneous ovulation. Additionally, two protocols to successfully stimulate ovarian activity in jaguars are described. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. FORTNIGHTLY MOLTING AND REPRODUCTIVE CYCLES IN THE SAND-BEACH ISOPOD, EXCIROLANA CHILTONI.

    Science.gov (United States)

    Klapow, L A

    1972-12-01

    1. The isopod, Excirolana chiltoni is found buried in the sand in a narrow zonal band on the high intertidal beach during low tide and emerges only during high tide to swim and forage in the wave wash. The position of the zonal band during low tides bears a consultant relationship to the level of the water line during the preceding high tide. Because of this relationship the isopod zone moves up and down the beach on a fortnightly schedule which corresponds to the semi-monthly variation in tide amplitudes (the spring-neap cycle). 2. Excirolana chiltoni stores considerable quantities of mineral prior to ecdysis in localized concretions of the integument (dermoliths). 3. Molting takes place in two steps. First the posterior portion of the isopod including the abdomen and last 3 thoracic segments is cast which is followed by the casting of the anterior portion of the animal. Isopods which are in the process of molting can be easily recognized since the newly exposed posterior exoskeleton is fully expanded before the anterior cast is made. 4. The development of dermoliths and the relative abundance of half-molted individuals were used to determine the frequence of molting in a field population which was sampled at 2 day intervals for a period of a month. These data indicate that molting is largely if not entirely restricted to the weeks preceding new or full moon when the amplitude of the tides is increasing. 5. Excirolana chiltoni also shows fortnightly periodicities in feeding and the degree to which it is infested with external parasites. 6. Indirect evidence suggests that the release of young also follows a fortnightly schedule and is most intense at the same phase of the spring-neap cycle that the population molts. Females retain their broods internally and might therefore be capable of controlling the timing of birth with considerable precision. 7. Synchronous molting was not as apparent in populations which were held under non-tidal conditions in the laboratory

  12. Stable transfection of Eimeria intestinalis and investigation of its life cycle, reproduction and immunogenicity

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    Tuanyuan eShi

    2016-05-01

    Full Text Available Rabbit coccidiosis, caused by infection of Eimeria spp. is one of the most severe parasitic diseases in rabbits. E. intestinalis is one of the most immunogenic species in rabbit coccidia. Due to the lack of genomic information and unsuccessful in vitro cultivation, genetic manipulation of rabbit coccidia lagged behind other apicomplexan parasites. Using regulatory sequences from E. tenella, we obtained a transgenic line of E. intestinalis expressing yellow fluorescent protein (YFP. YFP was continuously expressed throughout the whole life cycle. Morphological features of E. intestinalis in the different developmental stages were dynamically observed with the transgenic line. Some important features in the endogenous development stages were observed. Trophozoites were found as early as 4 h post inoculation. Two-types of schizonts and merozoites were observed in first three of the four schizogonies. Beside jejunum and ileum, gametogony stage and oocysts were also found in the duodenum and vermiform appendix. In addition, the transgenic strain was highly immunogenic but less pathogenic than the wild type. Considering the high immunogenicity of E. intestinalis and amenability to transfection with foreign genes, transgenic E. intestinalis could be a promising oral eukaryotic vaccine vector.

  13. A Randomized Trial to Evaluate the Effect of Local Endometrial Injury on the Clinical Pregnancy Rate of Frozen Embryo Transfer Cycles in Patients With Repeated Implantation Failure

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    Ensieh Shahrokh-Tehraninejad

    2016-12-01

    Full Text Available Objective: Repeated implantation failure (RIF is a condition in which the embryos implantation decreases in the endometrium. So, our aim was to evaluate the effect of local endometrial injury on embryo transfer results.Materials and methods: In this simple randomized clinical trial (RCT, a total of 120 patients were selected. The participants were less than 40 years old, and they are in their minimum two cycles of vitro fertilization (IVF. Patients were divided randomly into two groups of LEI (Local endometrial injury and a control group (n = 60 in each group. The first group had four small endometrial injuries from anterior, posterior, and lateral uterus walls which were obtained from people who were in 21th day of their previous IVF cycle. The second group was the patients who have not received any intervention.Results: The experimental and control patients were matched in the following factors. Regarding the clinical pregnancy rate, there was no significant difference noted between the experimental and the control group.Conclusion: Local endometrial injury in a preceding cycle does not increase the clinical pregnancy rate in the subsequent FET cycle of patients with repeated implantation failure.

  14. Cloning of Vasa and expression analysis during the reproductive cycle in Cynoglossus semilaevis Giinther%半滑舌鳎Vasa基因cDNA克隆及其在繁殖周期的表达

    Institute of Scientific and Technical Information of China (English)

    张远青; 温海深; 何峰; 李吉方; 史丹; 胡健; 刘淼; 母伟杰; 马瑞芹

    2012-01-01

    The Vasa gene encodes a protein of DEAD-box family that is essential for PGCs proliferation. In this study,we characterized the cDNA of Vasa and researched its expression in the reproductive cycle of Cynoglossus semilaevis through RACE and RT-PCR technology, aiming to clarify its function in gametogenesis of fishes. The length ef Vasa gene is 2 602 bp and this gene encodes a protein of 722 amino acids. The dudced amino acid sequence contains 8 conserved motifs of DEAD-box family protein, 5 RGG repeats and 10 RG repeats in N-terminal region. Comparisons of the deduced amino acid sequence with those of other vertebrates and invertebrates revealed the highest homology (91% ) with Thunnus orientalis. Vasa was strongly expressed in gonad and little expressed in heart. In the reproductive cycle, the transcript level of Vasa gene in the primary yolk stage and tertiary yolk stage is higher than peri-nucleolus stage and atretic follicles in ovary. The transcript level of spermatogenesis stage is obviously higher than that of spermatocyte stage and spermiation stage. These results suggest that Vasa gene may play an important role in spermatogenesis and oogenesis during reproductive cycle.%通过简并引物和RACE技术分离得到了半滑舌鳎Vasa基因的cDNA序列,其全长为2 602 bp,编码包含722个氨基酸残基的蛋白质.半滑舌鳎Vasa在N末端含有5个RGG重复和10个RG重复,具备DEAD-box家族特有的8个保守基序,与东方蓝旗鲔的同源性最高(91%).利用RT-PCR技术研究了csVasa在性成熟半滑舌鳎中的表达模式.组织分布研究发现,Vasa在半滑舌鳎的卵巢和精巢中表达丰富,心脏中有微量表达;繁殖周期中,卵巢中Vasa的表达量在初级卵黄期和囊泡期要明显高于核周期和退化吸收期;精巢中,Vasa在精子细胞增殖期的表达量要显著高于精子成熟期和精母细胞增殖期.结果表明,Vasa可能在半滑舌鳎的配子发生中起重要作用.

  15. Gametogenesis and reproductive cycle of Melanorivulus aff. punctatus (Boulenger, 1895 (Cyprinodontiformes, Rivulidae in Chapada dos Guimarães, Mato Grosso, Brazil

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    Monica Cassel

    Full Text Available The comprehension of the reproductive cycle allows to understand which are the morphological changes that develop in the gonad during this interval. Thus, many studies have been undertaken in order to describe and classify the stages of gonadal development and reproductive status of Neotropical fishes. For this purpose, specimens of Melanorivulus aff. punctatus were collected in a permanent dam in Chapada dos Guimarães, Mato Grosso, Brazil. The gonads were prepared for analysis by light microscopy. The oogenesis and spermatogenesis have been described, characterizing the stages of gonadal development, together with assessments of the gonadosomatic ratio, germ cell count and verification of variation of mature oocytes in females. Throughout the year the male gonads presented themselves as capable of reproducing, characterized by the presence of undifferentiated and differentiated spermatogonia, spermatocytes organized into cysts, spermatids in cysts whose wall was thicker and the spermatozoa was free in the lumen and the duct. This can indicate a continuous reproductive cycle with split spermiation. The females had gonads in the development stage from May to September with undifferentiated and differentiated oogonias and early oocytes always facing the lumen, abundant pre-vitellogenic and vitellogenic oocytes and some atresias. In the phase capable of spawning, observed from October to March, the mature oocytes are abundant, there are many post-ovulatory complexes and some atresia in advanced stage. The regression, observed in some individuals from February to April, is characterized by ovaries with many atresias and post-ovulatory complexes. The same results were found in the quantitative assessments. Therefore, it may be characterized as discontinuous cycle with split spawning. Thus, the reproductive cycle of this species can be characterized as continuous for males and discontinuous for females, which have a most intense phase of reproduction

  16. Dynamics of ovarian maturation during the reproductive cycle of Metynnis maculatus, a reservoir invasive fish species (Teleostei: Characiformes

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    Thiago Scremin Boscolo Pereira

    Full Text Available In this study, we evaluated the dynamics of ovarian maturation and the spawning processes during the reproductive cycle of Metynnis maculatus. Adult females (n = 36 were collected bimonthly between April 2010 and March 2011. The mean gonadosomatic index (GSI was determined, ovarian and blood samples were submitted for morphometric evaluation and the steroid plasma concentration was determined by ELISA. This species demonstrated asynchronous ovarian development with multiple spawns. This study revealed that, although defined as a multiple spawning species, the ovaries of M. maculatus have a pattern of development with a predominance of vitellogenesis between April and August and have an intensification in spawning in September; in October, a drop in the mean GSI values occurred, and the highest frequencies of post-ovulatory follicles (POFs were observed. We observed a positive correlation between the POF and the levels of 17α-hydroxyprogesterone. Metynnis maculatus has the potential to be used as a source of pituitary tissue for the preparation of crude extracts for hormonal induction; the theoretical period for use is from September to December, but specific studies to determine the feasibility of this approach must be conducted.

  17. Genome-Wide Analyses of Individual Strongyloides stercoralis (Nematoda: Rhabditoidea) Provide Insights into Population Structure and Reproductive Life Cycles

    Science.gov (United States)

    Aung, Myo Pa Pa Thet Hnin Htwe; Afrin, Tanzila; Nagayasu, Eiji; Tanaka, Ryusei; Higashiarakawa, Miwa; Win, Kyu Kyu; Hirata, Tetsuo; Htike, Wah Win; Fujita, Jiro; Maruyama, Haruhiko

    2016-01-01

    The helminth Strongyloides stercoralis, which is transmitted through soil, infects 30–100 million people worldwide. S. stercoralis reproduces sexually outside the host as well as asexually within the host, which causes a life-long infection. To understand the population structure and transmission patterns of this parasite, we re-sequenced the genomes of 33 individual S. stercoralis nematodes collected in Myanmar (prevalent region) and Japan (non-prevalent region). We utilised a method combining whole genome amplification and next-generation sequencing techniques to detect 298,202 variant positions (0.6% of the genome) compared with the reference genome. Phylogenetic analyses of SNP data revealed an unambiguous geographical separation and sub-populations that correlated with the host geographical origin, particularly for the Myanmar samples. The relatively higher heterozygosity in the genomes of the Japanese samples can possibly be explained by the independent evolution of two haplotypes of diploid genomes through asexual reproduction during the auto-infection cycle, suggesting that analysing heterozygosity is useful and necessary to infer infection history and geographical prevalence. PMID:28033376

  18. The reproductive cycle, size at maturity and fecundity of garfish ( Belone belone, L. 1761) in the eastern Adriatic Sea

    Science.gov (United States)

    Zorica, B.; Sinovčić, G.; Keč, V. Čikeš

    2011-12-01

    A recent study concerning the reproductive biology of the garfish ( Belone belone, L. 1761) has been carried out in the eastern part of the Adriatic Sea along the Croatian coastline. Specimens of the fish ( N = 3,393) were collected over a 6-year period (2003-2008). Their length varied between 20.8 and 75.4 cm (mean ± SD = 38.3 ± 7.94). Female garfish were dominant in larger length groups being most apparent during the resting phase of sexual cycle and in the peak of the spawning period, occurring in April and May. The sexual ratio of all specimens was m/f = 0.98. Males were prevalent in March—at the beginning of the highest spawning activities. Fifty percentage of the garfish population sexually matured at 28.5 cm of total length. Males and females reached their sexual maturity at 28.0 and 31.5 cm of total length, respectively. Spawning began in January peaking during March to May. According to their maturity stages, gonad weight and the gonadosomatic index, males began to spawn one month earlier (April) than females (May). The mean batch fecundity of garfish was 1,242.46 ± 843.64 of matured oocytes per ovary. Matured oocyte diameters ranged from 1.223 to 4.283 mm with the mean value of 2.269 ± 0.332 mm.

  19. FT Duplication Coordinates Reproductive and Vegetative Growth

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Chuan-Yu [Mississippi State University (MSU); Adams, Joshua P. [Mississippi State University (MSU); Kim, Hyejin [Mississippi State University (MSU); No, Kyoungok [Mississippi State University (MSU); Ma, Caiping [Oregon State University, Corvallis; Strauss, Steven [Oregon State University, Corvallis; Drnevich, Jenny [University of Illinois, Urbana-Champaign; Wickett, Norman [Pennsylvania State University; Vandervelde, Lindsay [Mississippi State University (MSU); Ellis, Jeffrey D. [Mississippi State University (MSU); Rice, Brandon [Mississippi State University (MSU); Gunter, Lee E [ORNL; Tuskan, Gerald A [ORNL; Brunner, Amy M. [Virginia Polytechnic Institute and State University (Virginia Tech); Page, Grier P. [RTI International; Carlson, John E. [Pennsylvania State University; DePamphilis, Claude [Pennsylvania State University; Luthe, Dawn S. [Pennsylvania State University; Yuceer, Cetin [Mississippi State University (MSU)

    2011-01-01

    Annual plants grow vegetatively at early developmental stages and then transition to the reproductive stage, followed by senescence in the same year. In contrast, after successive years of vegetative growth at early ages, woody perennial shoot meristems begin repeated transitions between vegetative and reproductive growth at sexual maturity. However, it is unknown how these repeated transitions occur without a developmental conflict between vegetative and reproductive growth. We report that functionally diverged paralogs FLOWERING LOCUS T1 (FT1) and FLOWERING LOCUS T2 (FT2), products of whole-genome duplication and homologs of Arabidopsis thaliana gene FLOWERING LOCUS T (FT), coordinate the repeated cycles of vegetative and reproductive growth in woody perennial poplar (Populus spp.). Our manipulative physiological and genetic experiments coupled with field studies, expression profiling, and network analysis reveal that reproductive onset is determined by FT1 in response to winter temperatures, whereas vegetative growth and inhibition of bud set are promoted by FT2 in response to warm temperatures and long days in the growing season. The basis for functional differentiation between FT1 and FT2 appears to be expression pattern shifts, changes in proteins, and divergence in gene regulatory networks. Thus, temporal separation of reproductive onset and vegetative growth into different seasons via FT1 and FT2 provides seasonality and demonstrates the evolution of a complex perennial adaptive trait after genome duplication.

  20. Repeated-Sprint Cycling Does Not Induce Respiratory Muscle Fatigue in Active Adults: Measurements from The Powerbreathe® Inspiratory Muscle Trainer

    Directory of Open Access Journals (Sweden)

    Clare Minahan, Beth Sheehan, Rachel Doutreband, Tom Kirkwood, Daniel Reeves, Troy Cross

    2015-03-01

    Full Text Available This study examined respiratory muscle strength using the POWERbreathe® inspiratory muscle trainer (i.e., ‘S-Index’ before and after repeated-sprint cycling for comparison with maximal inspiratory pressure (MIP values obtained during a Mueller maneuver. The S-Index was measured during six trials across two sessions using the POWERbreathe® and MIP was measured during three trials in a single session using a custom-made manometer in seven recreationally active adults. Global respiratory muscle strength was measured using both devices before and after the performance of sixteen, 6-s sprints on a cycle ergometer. Intraclass correlation coefficients for the POWERbreathe® S-index indicated excellent (p 0.99 and during the Mueller maneuver (p > 0.99. The POWERbreathe® S-Index is a moderately reliable, but not equivalent, measure of MIP determined during a Mueller maneuver. Furthermore, repeated-sprint cycling does not induce globalized respiratory muscle fatigue in recreationally-active adults.

  1. Day-night and reproductive cycle profiles of melatonin receptor, kiss, and gnrh expression in orange-spotted grouper (Epinephelus coioides).

    Science.gov (United States)

    Chai, Ke; Liu, Xiaochun; Zhang, Yong; Lin, Haoran

    2013-07-01

    It is suggested that the MT1 melatonin receptor mediates the effects of melatonin on reproduction in rodents. Three melatonin receptor types, MT1, MT2, and Mel1c, have been identified in fish. To understand the potential roles of each type of melatonin receptor on reproduction, we explored the day-night and reproductive cycle profiles of melatonin receptor, kiss, and gnrh expression in the orange-spotted grouper (Epinephelus coioides). cDNAs encoding melatonin receptors (MT1, MT2, and Mel1c) were first isolated from the brain of the orange-spotted grouper. Quantitative real-time PCR analysis demonstrated that the expression levels of MT1 and MT2 were higher in most of the brain areas and pituitary, while mel1c mRNA was mainly distributed in some peripheral tissues and the pituitary. The expression levels of MT1 were much higher than those of MT2 and mel1c in most of the brain regions, and the day-night expression variations of MT1 were counter to those of kiss2 and gnrh1. Reproductive cycle variations in MT1 daytime expression were different from those for kiss2 and gnrh1, and contrary to ovarian fecundity. Our results suggest that MT1 may modulate gnrh1 expression through kiss2, or may directly influence it. Together, these signal cascades may regulate the seasonal breeding of the orange-spotted grouper. As the day-length variations were consistent with the ovarian fecundity variation observed during the reproductive cycle, we infer that photoperiod affects ovarian development of the orange-spotted grouper through MT1.

  2. Reproductive cycle of the swimming crab Portunus spinimanus Latreille (Crustacea, Decapoda, Brachyura from Ubatuba, São Paulo, Brazil

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    Sandro Santos

    1999-01-01

    Full Text Available This study analyses some reproductive aspects of Portunus spinimanus Latreille, 1819, a crab usually commercialized in Ubatuba region. Monthly otter-trawl collections were taken for two years along the northern coast of São Paulo State, Brazil. The reproductive period was studied based on the frequency of ovigerous females in the population along the year; the frequency of physiologically mature swimming crabs and the type of spawn. The condition of development of ovigerous females ovary was associated with the stage of eggs development. This species presents continuous reproduction in Ubatuba region and total spawn, but with successive broods, which suggests a multiple spawn during the reproduction period.

  3. The effect of repeated freeze-thaw cycles on human muscle tissue visualized by postmortem computed tomography (PMCT).

    Science.gov (United States)

    Klop, Anthony C; Vester, Marloes E M; Colman, Kerri L; Ruijter, Jan M; Van Rijn, Rick R; Oostra, Roelof-Jan

    2017-09-01

    The aim of this study was to determine whether effects of repetitive freeze-thaw cycles, with various thawing temperatures, on human muscle tissue can be quantified using postmortem computed tomography (PMCT) technology. An additional objective was to determine the preferred thawing temperature for muscle tissue in this study. Human cadaver upper extremities were divided into two different thawing temperature groups and underwent a series of four freeze-thaw cycles in total. Axial CT scans were performed after each cycle. CT attenuation (in Hounsfield units, HU) was measured in four muscles of the upper extremities. HU values changed significantly with the introduction of each subsequent freeze-thaw cycle. Moreover, the changes in HU values were different for each thawing group. There was a significant increase of HU values in both groups between t0 and t1 . Unfrozen tissue showed large variation of HU values in all samples. It was possible to distinguish between samples thawed at different thawing temperatures based on their respective HU values. It is advisable to keep the number of freeze-thaw cycles to just one, if the human cadaveric tissue is to be used for educational purposes. The preferred thawing temperature in this study is 2°C. Clin. Anat. 30:799-804, 2017. © 2017Wiley Periodicals, Inc. © 2017 The Authors Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.

  4. Photoperiod, temperature, and food availability as drivers of the annual reproductive cycle of the sea urchin Echinometra sp. from the Gulf of Aqaba (Red Sea)

    Science.gov (United States)

    Bronstein, Omri; Loya, Yossi

    2015-03-01

    In spite of the efforts invested in the search for the environmental factors that regulate discrete breeding periods in marine invertebrates, they remain poorly understood. Here, we present the first account of the annual reproductive cycle of the pantropical sea urchin Echinometra sp. from the Gulf of Aqaba/Eilat (Red Sea) and explore some of the main environmental variables that drive echinoid reproduction. Monthly measurements of gonado-somatic indexes and histological observations of 20 specimens revealed a single seasonal reproductive cycle, with gametogenesis in males and females being highly synchronized. Gametogenesis commenced in June and peak spawning occurred between September and October. Gonado-somatic indexes were significantly correlated with seawater temperatures but not with photoperiod. The latter cycle lagged behind the gonado-somatic cycle by two months, suggesting that the onset of gametogenesis corresponds to shortening day length, while spawning may be driven by warming seawater temperatures. Gonads remained quiescent throughout the winter and spring (January through May) when temperatures were at their lowest. Chlorophyll- a concentrations increased significantly in the months following spawning (October through January). These high concentrations are indicative of high phytoplankton abundance and may reflect the increase in food availability for the developing larvae. Of the external test dimensions, length presented the highest correlation to body weight, indicating length as the best predictor for body size in Echinometra. Neither sexual dimorphism nor size differences between males and females were detected, and the sex ratios were approximately 1:1 in three distant Echinometra populations. Environmentally regulated reproduction, as occurs in sea urchins, might face severe outcomes due to anthropogenic disturbances to the marine environment. Consequently, there is a need to deepen our understanding of the mechanisms that drive and

  5. Squalus cubensis Reproduction Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Reproductive data from Squalus cubensis (Cuban dogfish) were opportunistically collected from 2005-2012. Data include those necessary to examine reproductive cycle,...

  6. Lipid and fatty acid content in wild white seabream (Diplodus sargus) broodstock at different stages of the reproductive cycle.

    Science.gov (United States)

    Pérez, M J; Rodríguez, C; Cejas, J R; Martín, M V; Jerez, S; Lorenzo, A

    2007-02-01

    The lipid and fatty acid content of the gonads, liver and muscle of wild white seabream males and females was studied at different stages of the reproductive cycle. Samples were taken from mature white seabream at pre-spawning (November), mid-spawning (March) and post-spawning (June) stages. The results showed that lipid accumulates in gonads and muscle from November to March. The gonadosomatic index (GSI) was also increased during this period. Male gonads showed a greater increase in polar lipid (PL) than neutral (NL), while female gonads displayed the reverse. The increase in both neutral and polar lipid was higher in the muscle of males than in females. In the same period, male livers showed no changes either in lipid content or the hepatosomatic index (HSI), while female livers registered an increase in both lipid content and HSI. Between March and June, in both males and females, total, neutral and polar lipid decreased sharply in the gonads and muscle. Muscular lipid content reduction was more pronounced in males than females. On the other hand, the lipid content of the liver in males and females remained relatively constant. In general terms, the amounts of major fatty acids (16:0, 18:1n-9, 20:5n-3 and 22:6n-3) in gonadal and muscular polar and neutral lipid in both males and females increased from November to March and declined thereafter. Variations of the liver fatty acid content were less extreme. In the period from mid-spawning to post-spawning, the presence of 20:4n-6 in polar and neutral lipid increased to a notable extent in all organs studied.

  7. Natural history of Ctenus medius Keyserling, 1891 (Aranae, Ctenidae II: life cycle and aspects of reproductive behavior under laboratory conditions

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    FOLLY-RAMOS E.

    2002-01-01

    Full Text Available Ctenus medius Keyserling, 1891 is a wandering spider common in the Brazilian Atlantic Forest. It has been the subject of few studies. Thus, this work aims to elucidate aspects of its natural history, such as the life cycle and reproductive behavior of this species, through laboratory and field observations. Two females with egg sacs were observed in the laboratory and one was observed in field (Barra Mansa, 22º32'S and 44º10'W until the emergence of the spiderlings. For observation of the immature stage development, a portion of the spiderlings from the same hatch were taken to the laboratory and watched until sexual maturity. In the field, the period between the oviposition and the emergence of spiderlings was of 36 days. The female selects a site for egg sac deposition and stays there until the spiderlings emerge. Seven days after the emergence, the female abandoned the site where the egg sac was made, concomitant to the spiderlings dispersion from observation's place and until the moment that the spiderlings started to eat. For the spiderlings kept under laboratory conditions, cannibalism was not observed in the first instars (1-4th when sufficient food was offered. Sexual maturity happened in the 14th or 15th instars, with an average of 309.2 to 344.5 days until the last/sexual molt, respectively. Until the date of sexual maturity, there was a mortality rate of 85%. This species is very fragile in captivity. This hampered deductions concerning longevity. Both females and males collected in the field were induced to mate in the laboratory. Courtship movements of males were registered, but the females did not permit the mating. These data may assist in initial biological studies of Ctenus genus and offer comparative parameters for studies of other related species.

  8. Gonadogenesis and annual reproductive cycles of an endangered cyprinid fish, the lake minnow Eupallasella percnurus (Pallas, 1814).

    Science.gov (United States)

    Hliwa, Piotr; Król, Jarosław; Sikorska, Justyna; Wolnicki, Jacek; Dietrich, Grzegorz J; Kamiński, Rafał; Stabińska, Agnieszka; Ciereszko, Andrzej

    2017-01-01

    In this study, gonadogenesis, the effect of temperature (15, 20 and 25°C) on sex differentiation, and annual changes in the gonads of mature lake minnow Eupallasella percnurus (Pallas, 1814) were determined. The lake minnow was found to be a primary gonochoristic fish species, where gonads are formed directly in the ovaries or testes. The morphological differentiation of gonads was initiated 35days post hatch (DPH) when two types of gonadal anlages were visible: a pear-shaped gonad attached by a single mesentery string and a spindle-shaped gonad attached on both sides to the peritoneum. Gonadogenesis occurred faster in females than in males, with the first previtellogenic oocytes and ovarian lamellae being already observed in 45 DPH fish. In males, cytological differentiation occurred approximately 85 DPH, when the fish reached an average body weight of more than 400mg. No significant effect of rearing temperature on sex ratio in lake minnow juveniles was observed. The proportion of males and females was similar (close to 1:1) in all of the thermal-treated groups, although there were effects of temperature on the final sizes of fish. Histological examination of wild, mature lake minnow ovaries during the annual cycle (from May to February the following year) showed asynchronous oocyte maturation. The testes were characteristic of multi-batch spawning fish. Quantitative dominance of spermatids and mature spermatozoa in May was observed, while the presence of primary and secondary spermatocytes in all other periods was confirmed. These changes were also reflected in the seasonal variation in the gonado-somatic index in both sexes, with the highest mean values of 11.2% (females) and 4.0% (males) in May, which were found to be significantly different to all other periods. The data presented in this study provide an important contribution to our understanding of the biology and reproductive strategy of the endangered lake minnow.

  9. Variation of steroid concentrations during the reproductive cycle of the clam Ruditapes decussatus: a one year study in the gulf of Gabès area.

    Science.gov (United States)

    Ketata, I; Guermazi, F; Rebai, T; Hamza-Chaffai, A

    2007-06-01

    Progesterone, testosterone and estradiol-17beta were measured by radio-immunoassay (RIA) in the gonads of the clam Ruditapes decussatus. The reproductive cycle was also investigated. Our study covered a period of one year, from September 2003 to August 2004. The chosen site "Kerkennah", located out of industrial effluents, belongs to the gulf of Gabès area (Tunisia). Steroids varied from 178 to 2459 pg g(-1) wet mass for progesterone, from 40 to 326 pg g(-1) wet mass for testosterone and from 10 to 235 pg g(-1) wet mass for estradiol-17beta in females. However in males, these steroids ranged from 304 to 2303 pg g(-1) wet mass for progesterone, from 81 to 381 pg g(-1) wet mass for testosterone and from 48 to 168 pg g(-1) wet mass for estradiol-17beta. The reproductive cycle of R. decussatus, investigated by histological examination of gonadic sections, showed that gametogenesis occurred from April to February in males and from April to November in females. Progesterone and testosterone increased at the end of gametogenesis in both sexes. The highest estradiol-17beta was recorded at the beginning of vitellogenesis in females. Fluctuations in the levels of sex steroids during the reproductive cycle suggest their possible role as endogenous modulators of gametogenesis in R. decussatus. Although this species is considered as gonochoristic, 0.83% of hermaphrodites were observed.

  10. EPINEPHRINE CONCENTRATION IN WILD BOAR (SUS SCROFA L. SERUM AFTER REPEATED ELISA TESTED FREEZE-THAWING CYCLES

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    Neška Vukšić

    2013-06-01

    Full Text Available Blood samples for determining of epinephrine concentration and biochemical parameters in the blood serum of wild boars were taken from 42 healthy wild boars, both sexes, during the hunting season. All animals in good condition, body weight 20 to 95 kg, were divided into two groups up to 50 kg (group A and up to 95 kg (Group B. Epinephrine concentration was determined by ELISA twice: one week after taking samples and a month after repeated freezing at -80°C. It was higher in relation to the reference value of domestic pigs and human (109.45 pg/ml in A and 119.54 pg/ml in B group. Repeated freezing and re-analysis after a month were resulted in lower concentrations of epinephrine (12% in young and 11.17% in adult animal, but without statistical significance (P>0.05. Biochemical analysis results’ show increased glucose and triglycerides concentrations compared to the reference values, while other indicators were observed within or slightly increased referring to the normal range. The correlation between glucose and epinephrine was not determined.

  11. Use of NIRS to assess effect of training on peripheral muscle oxygenation changes in elite rugby players performing repeated supramaximal cycling tests.

    Science.gov (United States)

    Jones, Benjamin; Cooper, C E

    2014-01-01

    In most team sports, intermittent high intensity sprint efforts combined with short recovery periods have been identified as a key factor of physical performance; the ability to repeat these efforts at a sustained level is of great importance. Near-infrared spectroscopy (NIRS) has been proposed as a tool to monitor muscle oxygenation changes during such sprint efforts. The purpose of this study was to observe muscle reoxygenation rate (reoxy rate) (% s⁻¹) between sprint efforts in a repeat sprint cycle test. A two wavelength spatially resolved NIR spectrometer (Portamon, Artinis Inc.) was used to assess reoxy rate changes in the vastus lateralis of the dominant leg before and after a training stimulus. Eight UK premiership academy level rugby players were assessed (age 20.6 ± 0.9) years; height 187 ± 0.6 cm; weight 109.5 ± 8.6 kg; quadriceps skin fold 16.6 ± 4.5 mm); the subjects completed ten repeated 10-s cycle sprints interspersed with 40 s recovery, upon a Wattbike Pro cycle. Hemoglobin variables (ΔHHb, ΔtHb, ΔO₂Hb, ΔTSI %) during the sprint and the post-sprint reoxygenation rate (%TSI s⁻¹) were measured. During both cycle tests all subjects experienced a drop in muscle oxygen saturation (Pre-Δ - 12.39 ± 6.01 %), Post-Δ - 14.83 ± 3.88 %). Post-training, there was an increase in the extent of desaturation (drop in TSI %) in the group means, both for the biggest single change and the average of all ten changes. Seven out of eight players showed an increase based on the maximum change and six based on the average of their ten tests. Additionally, seven out of eight players showed a significant increase in ΔHHb (Pre-Δ + 76.80 ± 61.92, Post-Δ + 121.28 ± 69.76) (p < 0.01) (including the one player who did not show a significant effect on the TSI measure). Players who exercised at the highest power tended to decrease their muscle oxygenation to a greater extent. The number of bike training sessions undertaken correlated with improvements in

  12. Estradiol concentration and the expression of estrogen receptors in the testes of the domestic goose (Anser anser f. domestica) during the annual reproductive cycle.

    Science.gov (United States)

    Leska, A; Kiezun, J; Kaminska, B; Dusza, L

    2015-04-01

    Seasonal fluctuations in the activity of bird testes are regulated by a complex mechanism where androgens play a key role. Until recently, the role played by estrogens in males has been significantly underestimated. However, there is growing evidence that the proper functioning of the testes is associated with optimal estradiol (E2) concentration in both the plasma and testes of many mammalian species. Estrogens are gradually emerging as very important players in hormonal regulation of reproductive processes in male mammals. Despite the previously mentioned, it should be noted that estrogenic action is limited by the availability of specific receptors--estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). Interestingly, there is a general scarcity of information concerning the estrogen responsive system in the testes of male birds, which is of particular interest in exploring the phenomenon of seasonality of reproduction. To address this question, we have investigated for the first time the simultaneous expression of testicular ERα and ERβ genes and proteins with the accompanying plasma and testicular E2 concentrations during the annual reproductive cycle of male bird. The research model was the domestic goose (Anser anser f. domestica), a species whose annual reproductive cycle can be divided into 3 distinct phases characterized by changes in testicular activity. It has been revealed that the stable plasma E2 profile did not correspond to changing intratesticular E2 profile throughout the experiment. The expression of ERα and ERβ genes and proteins was detected in gander testes and it fluctuated on a seasonal basis with lower level in breeding and sexual reactivation stages and higher level during the nonbreeding stage. Our results demonstrated changes in testicular sensitivity to estrogens in male domestic goose during the annual reproductive cycle. The seasonal pattern of estrogen receptors (ERs) expression was analyzed against the hormonal

  13. REPRODUCTIVE CYCLE OF Leporinus copelandii (Pisces: Anostomidae FEMALES FROM THE LOWER PARAÍBA DO SUL RIVER BASIN, RJ – BRAZIL

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    Ana Paula Ribeiro Costa Erthal

    2015-12-01

    Full Text Available The aim of this study were investigate the reproductive biology of the fish Leporinus copelandii, a specie at risk of extinction in the lower Paraíba do Sul River basin. During a period of 14 months, a total of 143 females of red-piau were captured, between Itaocara and Campos dos Goytacazes cities (RJ, Brazil. A histological study shows four stages of the oocyte development (I, II, III and IV and five stages of the reproductive cycle of females: rest (1, initial maturation (2A, intermediary (2B, advanced (2C and spawned (4 were identified. The pattern of L. copelandii oocyte development suggests development type synchronous in two groups, characterizing total spawning. Spawned females were captured in November, two months after the peak of frequency of competent females for reproduction. Histologically, a little occurrence of empty follicles was observed in spawned females. The medium diameter of the type IV oocyte of the spawned females (1475.1 ± 884.3mm was significantly larger (Tukey, P <0.001; VC = 41.73%; n = 259 than advanced maturation females (1202.6 ± 245.3mm, what allows suggesting that the study place probably doesn't represent the reproductive area of L. copelandii.

  14. Annual male reproductive activity and stages of the seminiferous epithelium cycle of the large fruit-eating Artibeus lituratus (Chiroptera: Phyllostomidae

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    Alice A. Notini

    2015-06-01

    Full Text Available The large fruit-eating phyllostomid bat, Artibeus lituratus (Olfers, 1818, forearm 69-75 mm, body mass 66-82 g, has a diversified geographic distribution in the Neotropical region. Therefore it is subjected to different climatic conditions that affect its reproduction, leading to different reproductive strategies such as continuous reproduction, seasonal monoestry or seasonal bimodal polyestry. In this study we used morphometric and histological methods to analyze the annual reproductive activity of A. lituratus males in a population living in the Atlantic Forest, Southeastern Brazil. Testis mass, epididymis mass, gonadosomatic index, seminiferous tubule diameter, and Leydig cell nucleus diameter showed no significant differences (p > 0.05 in the two seasons (wet: October to March; dry: April to September. Additionally, the cauda epididymis was packed with sperm throughout the period of study. Our data indicate that in this population spermatogenic activity was continuous throughout the year. Slight variations in accumulated frequency of pre-meiotic, meiotic and post-meiotic stages of the seminiferous epithelium cycle were observed when compared to other bat species, probably due to species-specific characteristics.

  15. Effects of chronic DHEA treatment on central and peripheral reproductive parameters, the onset of vaginal opening and the estrous cycle in female rats.

    Science.gov (United States)

    Iwasa, Takeshi; Matsuzaki, Toshiya; Tungalagsuvd, Altankhuu; Munkhzaya, Munkhsaikhan; Yiliyasi, Mayila; Kato, Takeshi; Kuwahara, Akira; Irahara, Minoru

    2016-09-01

    The neonatal and/or prepubertal androgen milieu affects sexual maturation and reproductive function in adulthood. However, the effects of chronic dehydroepiandrosterone (DHEA) treatment on reproductive functions have not been fully elucidated. Therefore, the reproductive phenotypes and parameters of rats that had been subjected to chronic DHEA treatment were evaluated in this study. The chronic DHEA-treated (from postnatal day 23-12 weeks of age) rats exhibited earlier vaginal opening, indicating that DHEA treatment promotes sexual maturation. In addition, the estrus phase lasted longer in the DHEA-treated rats, suggesting that their estrous cycles had been disrupted. As the DHEA-treated rats' serum luteinizing hormone levels and hypothalamic Kiss1 mRNA expression levels were decreased and their uterine weight was increased, DHEA and/or estrogen might directly affect reproductive phenotypes. While DHEA treatment caused changes in body weight and body composition in chronic testosterone-treated models in previous studies, no such changes were seen in the present study.

  16. Seasonal variation of biochemical components in clam ( Saxidomus purpuratus Sowerby 1852) in relation to its reproductive cycle and the environmental condition of Sanggou Bay, China

    Science.gov (United States)

    Bi, Jinhong; Li, Qi; Zhang, Xinjun; Zhang, Zhixin; Tian, Jinling; Xu, Yushan; Liu, Wenguang

    2016-04-01

    Seasonal variation of biochemical components in clam ( Saxidomus purpuratus Sowerby 1852) was investigated from March 2012 to February 2013 in relation to environmental condition of Sanggou Bay and the reproductive cycle of clam. According to the histological analysis, the reproductive cycle of S. purpuratus includes two distinctive phases: a total spent and inactive stage from November to January, and a gametogenesis stage, including ripeness and spawning, during the rest of the year. Gametes were generated at a low temperature (2.1°C) in February. Spawning took place once a year from June to October. The massive spawning occurred in August when the highest water temperature and chlorophyll a level could be observed. The key biochemical components (glycogen, protein and lipid) in five tissues (gonad, foot, mantle, siphon and adductor muscle) were analyzed. The glycogen content was high before gametogenesis, and decreased significantly during the gonad development in the gonad, mantle and foot of both females and males, suggesting that glycogen was an important energy source for gonad development. The protein and lipid contents increased in the ovary during the gonad development, demonstrating that they are the major organic components of oocytes. The lipid and protein contents decreased in the testis, implying that they can provide energy and material for spermatogenesis. The results also showed that protein stored in the mantle and foot could support the reproduction after the glycogen was depleted.

  17. Cycle de reproduction et fécondité de Distichodus rostratus (Characiformes, Distichodontidae dans un bassin ouest africain (fleuve Bandama, Côte d'Ivoire

    Directory of Open Access Journals (Sweden)

    Goore, BG.

    2008-01-01

    Full Text Available Reproductive Cycle and Fecondity of Distichodus rostratus (Characiformes, Distichodontidae in a West African Basin (Bandama River, Ivory Coast. Distichodus rostratus (Günther, 1864 is a commercially important species but its reproductive biology is not well known. Reproductive cycle and fecundity of D. rostratus from the Bandama river have been studied for a year (July 2004 to June 2005. The spawning period was determined by analyzing the monthly evolution of the gonado-somatic index (GSI. The liver-somatic index (LSI and the condition factor (Kc were calculated and the corresponding curves were fitted. The degree of maturity was determined using macroscopic observation of the gonads. The percentage of mature specimens by sexes was calculated for each size class. However, the first size of maturity was determined by using a logistic function. Sex-ratio (1:1.61 observed was in favour of females. Standard length at first maturity was 39.6 cm for males and 46,3 cm for females. The ripe ovaries contained 81,048-100,747 eggs. The relative fecundity was 12,004 eggs per kg of body weight. The mean size of eggs was 1.19 mm. The GSI indicated a spawning period going from August to October. In this period, when GSI is high, LSI decreases. This can be explained by the use of the liver reserves for developing the gonads.

  18. A novel function of RNAs arising from the long terminal repeat of human endogenous retrovirus 9 in cell cycle arrest.

    Science.gov (United States)

    Xu, Lai; Elkahloun, Abdel G; Candotti, Fabio; Grajkowski, Andrzej; Beaucage, Serge L; Petricoin, Emanuel F; Calvert, Valerie; Juhl, Hartmut; Mills, Frederick; Mason, Karen; Shastri, Neal; Chik, Josh; Xu, Cynthia; Rosenberg, Amy S

    2013-01-01

    The human genome contains approximately 50 copies of the replication-defective human endogenous retrovirus 9 (ERV-9) and thousands of copies of its solitary long term repeat (sLTR) element. While some sLTRs are located upstream of critical genes and have enhancer activity, other sLTRs are located within introns and may be transcribed as RNAs. We found that intronic RNAs arising from U3 sLTRs of ERV-9 were expressed as both sense (S) and antisense (AS) transcripts in all human cells tested but that expression levels differed in malignant versus nonmalignant cells. In nonmalignant cells, AS was expressed at higher levels than S and at higher levels than in malignant cells; in malignant cells, AS was expressed at amounts equivalent to those of S RNA. Critically, U3 AS RNA was found to physically bind to key transcription factors for cellular proliferation, including NF-Y, p53, and sp1, indicating that such RNA transcripts may function as decoy targets or traps for NF-Y and thus inhibit the growth of human cancer cells. Indeed, short U3 oligodeoxynucleotides (ODNs) based on these RNA sequences ably inhibited proliferation of cancer cell lines driven by cyclins B1/B2, the gene targets of NF-Y.

  19. The reproductive cycle, condition index, and glycogen reserves of the cockles Cerastoderma glaucum from the Gulf of Gabès (Tunisia).

    Science.gov (United States)

    Karray, Sahar; Smaoui-Damak, Wafa; Rebai, Tarek; Hamza-Chaffai, Amel

    2015-11-01

    The gametogenic cycle of the Cerastoderma glaucum was analyzed using both qualitative and semi-quantitative methods. The condition index and glycogen concentrations were determined in order to provide information on energy storage. The cockles were collected monthly from a Bayyadha site located 15 km south of Sfax City (Gulf of Gabès) between January 2007 and January 2008. From histological point of view, we applied two approaches: (i) the qualitative method describing the various stages of gamete development for males and females during a cycle of 13 months, and (ii) the semi-quantitative method concerning the estimation of different tissue surfaces. The results showed that there is evidence of three periods of reproduction in this population. A comparison between the surfaces occupied by the three organs showed that the foot and the gonad surfaces are higher than the surface of the adductor muscle. This could suggest that these two organs are more involved in the process of glycogen reserve storage. The results of the glycogen concentrations in the different tissues (gonad, adductor muscle, and "remainders") show that during the second and third periods of reproduction, glycogen was stored in the adductor muscle and in the remainder during sexual rest, and in the gonad during the gametogenesis phases in order to supply the reproductive effort. On the contrary, in the first period of reproduction, the low concentrations of glycogen recorded in the gonad coincided with its high degree of development. This fact could be related to environmental conditions (low temperature and food) recorded during this period.

  20. Determination of the mechanism and extent of surface degradation in Ni-based cathode materials after repeated electrochemical cycling

    Directory of Open Access Journals (Sweden)

    Sooyeon Hwang

    2016-09-01

    Full Text Available We take advantage of scanning transmission electron microscopy and electron energy loss spectroscopy to investigate the changes in near-surface electronic structure and quantify the degree of local degradation of Ni-based cathode materials with the layered structure (LiNi0.8Mn0.1Co0.1O2 and LiNi0.4Mn0.3Co0.3O2 after 20 cycles of delithiation and lithiation. Reduction of transition metals occurs in the near-surface region of cathode materials: Mn is the major element to be reduced in the case of relatively Mn-rich composition, while reduction of Ni ions is dominant in Ni-rich materials. The valences of Ni and Mn ions are complementary, i.e., when one is reduced, the other is oxidized in order to maintain charge neutrality. The depth of degradation zone is found to be much deeper in Ni-rich materials. This comparative analysis provides important insights needed for the devising of new cathode materials with high capacity as well as long lifetime.

  1. Prediction of the lifetime productive and reproductive performance of Holstein cows managed for different lactation durations, using a model of lifetime nutrient partitioning

    DEFF Research Database (Denmark)

    Gaillard, Charlotte; Martin, O; Blavy, P

    2016-01-01

    The GARUNS model is a lifetime performance model taking into account the changing physiological priorities of an animal during its life and through repeated reproduction cycles. This dynamic and stochastic model has been previously used to predict the productive and reproductive performance of va...

  2. Differential effects of acute and repeat dosing with the H3 antagonist GSK189254 on the sleep–wake cycle and narcoleptic episodes in Ox−/− mice

    Science.gov (United States)

    Guo, RX; Anaclet, C; Roberts, JC; Parmentier, R; Zhang, M; Guidon, G; Buda, C; Sastre, JP; Feng, JQ; Franco, P; Brown, SH; Upton, N; Medhurst, AD; Lin, JS

    2009-01-01

    Background and purpose: Histamine H3 receptor antagonists are currently being evaluated in clinical trials for a number of central nervous system disorders including narcolepsy. These agents can increase wakefulness (W) in cats and rodents following acute administration, but their effects after repeat dosing have not been reported previously. Experimental approach: EEG and EMG recordings were used to investigate the effects of acute and repeat administration of the novel H3 antagonist GSK189254 on the sleep–wake cycle in wild-type (Ox+/+) and orexin knockout (Ox−/−) mice, the latter being genetically susceptible to narcoleptic episodes. In addition, we investigated H3 and H1 receptor expression in this model using radioligand binding and autoradiography. Key results: In Ox+/+ and Ox−/− mice, acute administration of GSK189254 (3 and 10 mg·kg−1 p.o.) increased W and decreased slow wave and paradoxical sleep to a similar degree to modafinil (64 mg·kg−1), while it reduced narcoleptic episodes in Ox−/− mice. After twice daily dosing for 8 days, the effect of GSK189254 (10 mg·kg−1) on W in both Ox+/+ and Ox−/− mice was significantly reduced, while the effect on narcoleptic episodes in Ox−/− mice was significantly increased. Binding studies revealed no significant differences in H3 or H1 receptor expression between Ox+/+ and Ox−/− mice. Conclusions and implications: These studies provide further evidence to support the potential use of H3 antagonists in the treatment of narcolepsy and excessive daytime sleepiness. Moreover, the differential effects observed on W and narcoleptic episodes following repeat dosing could have important implications in clinical studies. PMID:19413575

  3. Authors' reply to comment on "Are repeated assisted reproductive technology treatments and an unsuccessful outcome risk factors for unipolar depression in infertile women?"

    DEFF Research Database (Denmark)

    Sejbaek, Camilla S.; Pinborg, Anja; Hageman, Ida

    2016-01-01

    The aim of our national register-based study (1) was to investigate the risk of a new episode of unipolar depression among women treated with assisted reproductive technology (ART) in regards to whether they had achieved a live birth (as a result of treatment or spontaneous conception) or not. He...

  4. Repeated vitrification/warming of human sperm gives better results than repeated slow programmable freezing

    Institute of Scientific and Technical Information of China (English)

    Teraporn Vutyavanich; Worashorn Lattiwongsakorn; Waraporn Piromlertamorn; Sudarat Samchimchom

    2012-01-01

    In this study,we compared the effects of repeated freezing/thawing of human sperm by our in-house method of rapid freezing with slow programmable freezing.Sperm samples from 11 normozoospermic subjects were processed through density gradients and divided into three aliquots:non-frozen,rapid freezing and slow programmable freezing.Sperm in the rapid freezing group had better motility and viability than those in the slow freezing group (P<O.01) after the first,second and third cycles of freezing/thawing,but there was no difference in morphology.In the second experiment,rapid freezing was repeated three times in 20 subjects.The samples from each thawing cycle were evaluated for DNA fragmentation using the alkaline comet assay.DNA fragmentation began to increase considerably after the second cycle of freezing/thawing,but to a level that was not clinically important.In the third experiment,rapid freezing was done repeatedly in 10 subjects,until no motile sperm were observed after thawing.The median number of repeated freezing/thawing that yielded no motile sperm was seven (range:5-8,mean:6.8).In conclusion,we demonstrated that repeated freezing/thawing of processed semen using our rapid freezing method gave better results than standard slow programmable freezing.This method can help maximize the usage of precious cryopreserved sperm samples in assisted reproduction technology.

  5. Two periods of total testicular regression are peculiar events of the annual reproductive cycle of the black Myotis bat, Myotis nigricans (Chiroptera: Vespertilionidae).

    Science.gov (United States)

    Beguelini, Mateus R; Góes, Rejane M; Taboga, Sebastião R; Morielle-Versute, Eliana

    2014-01-01

    Myotis nigricans presents few and controversial reproductive data, which indicate geographical variation in reproduction. Thus, this study aimed to evaluate the seasonal modifications in testicular and epididymal morphologies in a tropical environment, submitting these organs to morphometric and immunohistochemical analysis. The observations revealed that this species presents two peaks of spermatogenic activity followed by two periods of total testicular regression (a quiescent pre-pubertal-like morphology, where only Sertoli cells and spermatogonia could be observed), in the same annual reproductive cycle, which seem to be only indirectly influenced by abiotic factors. This testicular behaviour seems to be synchronised with the caput and corpus epididymidis, but not with the cauda epididymidis, which presents aspects of sperm storage in May-June. The control of this variation seems to be directly linked to the expression of the androgen receptor, since, throughout the year, it is high in periods of testicular recrudescence and low in periods of deactivation. It is not thought to be directly linked to apoptosis, which is more pronounced in periods of recrudescence than in periods of regression.

  6. Some aspects on the reproductive cycle of European conger eel, Conger conger (Linnaeus, 1758 (Osteichthyes, Anguilliformes, Congridae captured from Western Algerian coasts: a histological description of spermatogenesis

    Directory of Open Access Journals (Sweden)

    Abi-ayad Sidi-Mohammed El-Amine

    2011-09-01

    Full Text Available The aim of this work was to study the annual reproductive cycle of European conger eel (Conger conger,Linnaeus, 1758 through analysis and description of spermatogenesis. A sample of 168 males was capturedbetween September 2008 and August 2009 from the Western coast of Algeria, from Béni Saf. Fish length andweight varied between 26.20-112 cm and 0.45-3.44 kg, respectively.Condition factors (K, gonadosomatic index (G.S.I. and hepatosomatic index (H.S.I. were calculatedmonthly. Factor K reached the minimum in August/September (0.10% corresponding to reproductive periodand a maximum in January (0.18%. Although G.S.I. values revealed to be statistically not significant, therewere two peaks for G.S.I., the first in March, denoting the beginning of spermatogenesis, and the second inAugust/September, indicating the reproduction period. H.S.I. reached a peak in December (1.90%, then thevalue decreased to a minimum in April.Histological analysis of testis allowed us to distinguish 5 stages summarized as follows: Stage 1:Spermatogonia A; Stage 2: Spermatogonia B; Stage 3: Spermatocytes and spermatids; Stage 4: Spermatocytes,spermatids and spermatozoa (cytodifferentiation of spermatids into spermatozoa; Stage 5: Spermatozoa(spermiogenesis or cytodifferentiation of spermatids into spermatozoa.

  7. Reproductive Cycle and Seasonal Variations in Lipid Content and Fatty Acid Composition in Gonad of the Cockle Fulvia mutica in Relation to Temperature and Food

    Institute of Scientific and Technical Information of China (English)

    LIU Wenguang; LI Qi; KONG Lingfeng

    2013-01-01

    From March 2004 to February 2005,seasonal variations in lipid content and fatty acid composition of gonad of the cockle Fulvia mutica (Reeve) were studied on the eastern coast of China in relation to the reproductive cycle and environment conditions (e.g.,temperature and food availability).Histological analysis as well as lipid and fatty acid analyses were performed on neutral and polar lipids of the gonad.Results showed that gametogenesis occurred in winter and spring at the expense of lipids previously accumulated in summer and autumn,whereas spawning occurred in summer (20.4-24.6℃).The seasonal variation in lipid content was similar to that of the mean oocyte diameter.In both neutral and polar lipids,the 20:5n-3 and 22:6n-3 levels were relatively higher than saturated fatty acids,and polyunsaturated fatty acids were abundant,with series n-3 as the predominant component.Seasonal variations in the 20:5n-3 and 22:6n-3 levels and the principal n-3 fatty acids were clearly related to the reproductive cycle.The ∑(n-3)and ∑(n-6) values were relatively high during January-May,and the associated unsaturation index was significantly higher than that in other months.The results suggest that fatty acids play an important role in the gametogenesis of F.mutica.

  8. Reproductive cycle and seasonal variations in lipid content and fatty acid composition in gonad of the cockle Fulvia mutica in relation to temperature and food

    Science.gov (United States)

    Liu, Wenguang; Li, Qi; Kong, Lingfeng

    2013-09-01

    From March 2004 to February 2005, seasonal variations in lipid content and fatty acid composition of gonad of the cockle Fulvia mutica (Reeve) were studied on the eastern coast of China in relation to the reproductive cycle and environment conditions ( e.g., temperature and food availability). Histological analysis as well as lipid and fatty acid analyses were performed on neutral and polar lipids of the gonad. Results showed that gametogenesis occurred in winter and spring at the expense of lipids previously accumulated in summer and autumn, whereas spawning occurred in summer (20.4-24.6°C). The seasonal variation in lipid content was similar to that of the mean oocyte diameter. In both neutral and polar lipids, the 20:5n-3 and 22:6n-3 levels were relatively higher than saturated fatty acids, and polyunsaturated fatty acids were abundant, with series n-3 as the predominant component. Seasonal variations in the 20:5n-3 and 22:6n-3 levels and the principal n-3 fatty acids were clearly related to the reproductive cycle. The Σ(n-3) and Σ(n-6) values were relatively high during January-May, and the associated unsaturation index was significantly higher than that in other months. The results suggest that fatty acids play an important role in the gametogenesis of F. mutica.

  9. Features of follicle-stimulating hormone-stimulated follicles in a sheep model: keys to elucidate embryo failure in assisted reproductive technique cycles.

    Science.gov (United States)

    Veiga-Lopez, Almudena; Dominguez, Veronica; Souza, Carlos J H; Garcia-Garcia, Rosa M; Ariznavarreta, Carmen; Tresguerres, Jesus A F; McNeilly, Alan S; Gonzalez-Bulnes, Antonio

    2008-05-01

    To evaluate the individual functionality of gonadotropin-stimulated preovulatory follicles, for understanding embryo failure in assisted reproductive technique cycles, in a sheep model. Observational, model study. Public research unit. Fifteen adult Manchega ewes. Synchronization of the estrous cycle with intravaginal progestagens and ovarian stimulation with FSH; evaluation of reproductive activity, plasma sampling, ovarian ultrasonography, and ovariectomies. Determination of estrus behavior, plasma and intrafollicular concentrations of E(2) and inhibin A, number and size of ovarian follicles, and developmental competence of oocytes. These results support the usefulness of serial measurements of plasma inhibin A for assessment of follicular growth during the FSH treatment, rather than of E(2) assays commonly used. Functionality of FSH-stimulated preovulatory follicles is clearly disturbed, as confirmed by a negative correlation between follicular size and intrafollicular concentrations of inhibin A and E(2) in preovulatory follicles after individual dissection; moreover, the ability of their oocytes to resume meiosis was diminished. Functionality of follicles in controlled ovarian stimulation (COS), and developmental competence of their oocytes, is disturbed by the high doses of gonadotropin supplied and finally determined by follicular sizes at starting FSH treatment.

  10. Does long-term fungicide exposure affect the reproductive performance of leaf-shredders? A partial life-cycle study using Hyalella azteca.

    Science.gov (United States)

    Baudy, Patrick; Zubrod, Jochen P; Konschak, Marco; Weil, Mirco; Schulz, Ralf; Bundschuh, Mirco

    2017-03-01

    Leaf-shredding amphipods play a critical role in the ecosystem function of leaf litter breakdown, a key process in many low order streams. Fungicides, however, may adversely influence shredders' behavior and the functions they provide, while there is only limited knowledge concerning effects on their reproductive performance. To assess the latter, a semi-static 56-day partial life-cycle bioassay using the model shredder Hyalella azteca (n = 30) was performed applying two environmentally relevant concentrations of a model fungicide mixture (i.e., 5 and 25 μg/L) composed of five fungicides with different modes of toxic action. Variables related to the food processing (leaf consumption and feces production), growth (body length and dry weight), energy reserves (lipid content), and reproduction (amplexus pairs, number and length of offspring) were determined to understand potential implications in the organisms' energy budget. While the fungicides did not affect leaf consumption, both fungicide treatments significantly reduced amphipods' feces production (∼20%) compared to the control. This observation suggests an increased food utilization to counteract the elevated and stress-related energy demand: although growth as well as energy reserves were unaffected, amplexus pairs were less frequently observed in both fungicide treatments (∼50-100%) suggesting a tradeoff regarding energy allocation favoring the maintenance of fundamental functions at the organism level over reproduction. As a result, the time to release of first offspring was delayed in both fungicide treatments (7 and 14 days) and the median number of offspring was significantly lower in the 25-μg/L treatment (100%), whereas offspring length remained unaffected. The results of this study thus indicate that chronic fungicide exposures can negatively impact shredders' reproductive performance. This may translate into lower abundances and thus a reduced contribution to leaf litter breakdown in

  11. Immunohistochemical study of pituitary cells in wild and captive Salminus hilarii (Characiformes: Characidae) females during the annual reproductive cycle

    OpenAIRE

    Honji,Renato Massaaki; Nóbrega, Rafael ; Pandolfi, Matias ; Shimizu, Akio ; Borella, Maria Ines; Moreira, Renata 

    2013-01-01

    Freshwater fish that live exclusively in rivers are at particular risk from fragmentation of the aquatic system, mainly the species that migrate upriver for reproduction. That is the case of Salminus hilarii, an important migratory species currently classified as “almost threatened” in the São Paulo State (Brazil), facing water pollution, dam construction, riparian habitat destruction and environmental changes that are even more serious in this State. Additionally, this species show ovulat...

  12. Seasonal variations in the biochemical composition and reproductive cycle of the ghost crab Ocypode quadrata (Fabricius, 1787) in Southern Brazil.

    Science.gov (United States)

    Antunes, Graziani de Freitas; do Amaral, Ana Paula Nunes; Ribarcki, Fabiana Pinto; Wiilland, Elenir de Fátima; Zancan, Denise Maria; Vinagre, Anapaula Sommer

    2010-06-01

    The ghost crab, Ocypode quadrata, is found on sandy beaches from the United States to Southern Brazil. Because there is still little information about the metabolism and reproduction of O. quadrata on the southern coast of Brazil, the objectives of this study were to (i) evaluate the effect of seasonal variations on the carbohydrate, lipid, and protein metabolism of O. quadrata at Rondinha Beach, a beach with high anthropogenic activity, and to compare it with data from Siriú Beach, which has less human activity; and (ii) describe the effect of seasonal variations on the histological characteristics of male and female gonads, in order to assess the reproductive capacity of the crabs. The gonads of male crabs showed no significant variations in the gonadosomatic index (GSI) and glycogen levels; however, histological analysis of the testes revealed that they are mature in the summer. In females, the GSI and glycogen values are higher in summer, concomitantly with the presence of mature oocytes. These results suggest that the reproductive peak of O. quadrata occurs in summer. The seasonal analysis of the biochemical parameters, as well as comparison with Siriú Beach, demonstrated that the ghost crabs of Rondinha Beach have a different pattern of metabolism than those of Siriú. This difference may be a consequence of differences in the environmental conditions as well as in the anthropogenic pressures, such as vehicle traffic and the increase in human population at the beach in summer.

  13. Actinobacillus pleuropneumoniae induces SJPL cell cycle arrest in G2/M-phase and inhibits porcine reproductive and respiratory syndrome virus replication.

    Science.gov (United States)

    Ferreira Barbosa, Jérémy A; Labrie, Josée; Beaudry, Francis; Gagnon, Carl A; Jacques, Mario

    2015-11-14

    Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important pathogens in the swine industry and causes important economic losses. No effective antiviral drugs against it are commercially available. We recently reported that the culture supernatant of Actinobacillus pleuropneumoniae, the porcine pleuropneumonia causative agent, has an antiviral activity in vitro against PRRSV in SJPL cells. Objectives of this study were (i) to identify the mechanism behind the antiviral activity displayed by A. pleuropneumoniae and (ii) to characterize the active molecules present in the bacterial culture supernatant. Antibody microarray analysis was used in order to point out cellular pathways modulated by the A. pleuropneumoniae supernatant. Subsequent, flow cytometry analysis and cell cycle inhibitors were used to confirm antibody microarray data and to link them to the antiviral activity of the A. pleuropneumoniae supernatant. Finally, A. pleuropneumoniae supernatant characterization was partially achieved using mass spectrometry. Using antibody microarray, we observed modulations in G2/M-phase cell cycle regulation pathway when SJPL cells were treated with A. pleuropneumoniae culture supernatant. These modulations were confirmed by a cell cycle arrest at the G2/M-phase when cells were treated with the A. pleuropneumoniae culture supernatant. Furthermore, two G2/M-phase cell cycle inhibitors demonstrated the ability to inhibit PRRSV infection, indicating a potential key role for PRRSV infection. Finally, mass spectrometry lead to identify two molecules (m/z 515.2 and m/z 663.6) present only in the culture supernatant. We demonstrated for the first time that A. pleuropneumoniae is able to disrupt SJPL cell cycle resulting in inhibitory activity against PRRSV. Furthermore, two putative molecules were identified from the culture supernatant. This study highlighted the cell cycle importance for PRRSV and will allow the development of new prophylactic or

  14. Opposing effects of D-aspartic acid and nitric oxide on tuning of testosterone production in mallard testis during the reproductive cycle

    Directory of Open Access Journals (Sweden)

    Assisi Loredana

    2008-07-01

    Full Text Available Abstract Background D-Aspartic acid (D-Asp and nitric oxide (NO play an important role in tuning testosterone production in the gonads of male vertebrates. In particular, D-Asp promotes either the synthesis or the release of testosterone, whereas NO inhibits it. In this study, we have investigated for the first time in birds the putative effects of D-Asp and NO on testicular testosterone production in relation to two phases of the reproductive cycle of the adult captive wild-strain mallard (Anas platyrhynchos drake. It is a typical seasonal breeder and its cycle consists of a short reproductive period (RP in the spring (April-May and a non reproductive period (NRP in the summer (July, a time when the gonads are quiescent. The presence and the localization of D-Asp and NO in the testis and the trends of D-Asp, NO and testosterone levels were assessed during the main phases of the bird's reproductive cycle. Furthermore, in vitro experiments revealed the direct effect of exogenously administered D-Asp and NO on testosterone steroidogenesis. Methods By using immunohistochemical (IHC techniques, we studied the presence and the distributional pattern of D-Asp and NO in the testes of RP and NRP drakes. D-Asp levels were evaluated by an enzymatic method, whereas NO content, via nitrite, was assessed using biochemical measurements. Finally, immunoenzymatic techniques determined testicular testosterone levels. Results IHC analyses revealed the presence of D-Asp and NO in Leydig cells. The distributional pattern of both molecules was in some way correlated to the steroidogenic pathway, which is involved in autocrine testosterone production. Indeed, whereas NO was present only during the NRP, D-Asp was almost exclusively present during the RP. Consistently, the high testosterone testicular content occurring during RP was coupled to a high D-Asp level and a low NO content in the gonad. By contrast, in sexually inactive drakes (NRP, the low testosterone

  15. Changes in lipid content and fatty acid composition along the reproductive cycle of the freshwater mussel Dreissena polymorpha: Its modulation by clofibrate exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lazzara, Raimondo; Fernandes, Denise, E-mail: deniseferna@gmail.com; Faria, Melissa; Lopez, Jordi F.; Tauler, Roma; Porte, Cinta, E-mail: cinta.porte@cid.csic.es

    2012-08-15

    Total lipids and fatty acid profiles were determined along the reproductive cycle of the zebra mussel (Dreissena polymorpha). A total of 33 fatty acids with carbon atoms from 14 to 22 were identified: palmitic acid (16:0) was the most abundant fatty acid (13-24%) followed by docosahexaenoic acid (DHA; 22:6n-3), eicosapentaenoic acid (EPA; 20:5n-3) and palmitoleic acid (16:1n-7). Some individual fatty acids (16:0, 16:2n-4, 18:1n-7, 18:2n-6, 18:3n-4, 18:4n-3, 20:4n-3, 20:5n-3) were strongly related to reproductive events, while others having structural-type functions (18:0 and 22:6n-3) were rather stable during the study period. Multivariate analysis of the whole data set using the multivariate curve resolution alternating least squares method confirmed the strong relationship of fatty acid profiles with the reproductive cycle of zebra mussel. Additionally, the effects of the pharmaceutical clofibrate on lipid composition and fatty acid profiles were assessed following 7-day exposure of zebra mussels to a wide range of concentrations (20 ng/L to 2 mg/L). A significant reduction in total triglycerides (38%-48%) together with an increase in the amount of fatty acids per gram wet weight (1.5- to 2.2-fold) was observed in the exposed mussels. This work highlights the ability of clofibrate to induce changes on the lipidome of zebra mussels at concentrations as low as 200 ng/L. -- Highlights: Black-Right-Pointing-Pointer Clofibrate exposure leads to a reduction of total triglycerides in zebra mussel. Black-Right-Pointing-Pointer The amount of fatty acids per gram wet weight increased in exposed mussels. Black-Right-Pointing-Pointer The effects were evidenced at concentrations of clofibrate as low as 200 ng/L. Black-Right-Pointing-Pointer Fatty acid profiles were closely related to reproductive events.

  16. Use of a statistical model to predict the potential for repeated dose and developmental toxicity of dermally administered crude oil and relation to reproductive toxicity.

    Science.gov (United States)

    McKee, Richard H; Nicolich, Mark; Roy, Timothy; White, Russell; Daughtrey, Wayne C

    2014-01-01

    Petroleum (commonly called crude oil) is a complex substance primarily composed of hydrocarbon constituents. Based on the results of previous toxicological studies as well as occupational experience, the principal acute toxicological hazards are those associated with exposure by inhalation to volatile hydrocarbon constituents and hydrogen sulfide, and chronic hazards are associated with inhalation exposure to benzene and dermal exposure to polycyclic aromatic compounds. The current assessment was an attempt to characterize the potential for repeated dose and/or developmental effects of crude oils following dermal exposures and to generalize the conclusions across a broad range of crude oils from different sources. Statistical models were used to predict the potential for repeated dose and developmental toxicity from compositional information. The model predictions indicated that the empirical data from previously tested crude oils approximated a "worst case" situation, and that the data from previously tested crude oils could be used as a reasonable basis for characterizing the repeated dose and developmental toxicological hazards of crude oils in general.

  17. Probing the effect of human normal sperm morphology rate on cycle outcomes and assisted reproductive methods selection.

    Directory of Open Access Journals (Sweden)

    Bo Li

    Full Text Available Sperm morphology is the best predictor of fertilization potential, and the critical predictive information for supporting assisted reproductive methods selection. Given its important predictive value and the declining reality of semen quality in recent years, the threshold of normal sperm morphology rate (NSMR is being constantly corrected and controversial, from the 4th edition (14% to the 5th version (4%. We retrospectively analyzed 4756 cases of infertility patients treated with conventional-IVF(c-IVF or ICSI, which were divided into three groups according to NSMR: ≥14%, 4%-14% and <4%. Here, we demonstrate that, with decrease in NSMR(≥14%, 4%-14%, <4%, in the c-IVF group, the rate of fertilization, normal fertilization, high-quality embryo, multi-pregnancy and birth weight of twins gradually decreased significantly (P<0.05, while the miscarriage rate was significantly increased (p<0.01 and implantation rate, clinical pregnancy rate, ectopic pregnancy rate, preterm birth rate, live birth rate, sex ratio, and birth weight(Singleton showed no significant change. In the ICSI group, with decrease in NSMR (≥14%, 4%-14%, <4%, high-quality embryo rate, multi-pregnancy rate and birth weight of twins were gradually decreased significantly (p<0.05, while other parameters had no significant difference. Considering the clinical assisted methods selection, in the NFMR ≥14% group, normal fertilization rate of c-IVF was significantly higher than the ICSI group (P<0.05, in the 4%-14% group, birth weight (twins of c-IVF were significantly higher than the ICSI group, in the <4% group, miscarriage of IVF was significantly higher than the ICSI group. Therefore, we conclude that NSMR is positively related to embryo reproductive potential, and when NSMR<4% (5th edition, ICSI should be considered first, while the NSMR≥4%, c-IVF assisted reproduction might be preferred.

  18. [Survey of the cycle of reproduction of red algae Gelidium sesquipedale (Turner) Thuret (case of the maritime zone of El Jadida-Jarf lasfer of Morocco)].

    Science.gov (United States)

    Zidane, H; Orbi, A; Sqalli, N; Zidane, F; Talbaoui, M; Hasnaoui, M; Fakhaoui, M

    2006-08-01

    The industrial exploitation of the agarophyte, Gelidium sesquipedale, is an important part of the economy of Morocco, however the species is in danger of being overexploited. The development of research on the biological cycle of the species enbles a better understanding of environmental influencies on its reproduction periods and of the effect of pulling up on the growth of the thalli. This should assist in helping to avoid excessive collection of the species and to reinforce a period of rest where no collection takes place. The major are of collection supplying industries is the maritime sector of El Jadida - Jarf Lasfar. In order to study the methods of reproduction of G sesquipedale, a first series of experimentation was carried out by the INRH. Studies relating to biology and the effect of pulling up on the biometrics of the thalli of this species were carried out at two stations of the maritime zone El Jadida - Jarf lasfar: Moulay Abdellah and Sidi Bouzid during the period 2000-2002. The results obtained show that the fertile thalli are present all the year with a maximum reproductive activity in winter. The recruitment of the young slings takes place before the winter and occurs more in Sidi Bouzid. The regeneration and the growth of the thalli are carried out in spring and summer. To preserve this resource, it is necessary to put in place a system whereby one zone or area is allowed to rest whilst another area is cultivated for a year; whilst in the following year the rercise occurs.

  19. HABITAT DIFFERENCES IN THE TIMING OF REPRODUCTION OF THE INVASIVE ALGA SARGASSUM MUTICUM (PHAEOPHYTA, SARGASSACEAE) OVER TIDAL AND LUNAR CYCLES(1).

    Science.gov (United States)

    Monteiro, Carla; Engelen, Aschwin H; Serrão, Ester A; Santos, Rui

    2009-02-01

    Sargassum muticum (Yendo) Fensholt is an invasive species that is firmly established on intertidal and subtidal rocky shores of Europe and the Pacific coast of North America. Local success and spread of S. muticum is thought to rely on its reproductive potential that seems dependent on exogenous factors like tidal and lunar cycles. This study is the first to compare the reproductive patterns (periodicity of egg expulsion and embryo settlement) of this invader in two different habitats: the middle and low intertidal. The combination of monthly, daily, and tidal samples at triplicate sites within each habitat showed a semilunar periodicity of egg expulsion and embryo settlement coincident with increasing tidal amplitude just before full and new moons. In both habitats, duration of each egg expulsion event was ∼1 week, and embryo settlement occurred during the first daily low tide and with the incoming high tide during spring tides. However, both expulsion and settlement started 1-2 d earlier, expulsion saturation was faster, and settlement was higher in the mid- compared to the low intertidal. Our results suggest that the exact timing of gamete expulsion and embryo release of S. muticum responds to local factors, including tidal cues, which result in differences between mid- and low-intertidal habitats. © 2009 Phycological Society of America.

  20. Long-term effects of antibiotics, norfloxacin, and sulfamethoxazole, in a partial life-cycle study with zebrafish (Danio rerio): effects on growth, development, and reproduction.

    Science.gov (United States)

    Yan, Zhenhua; Lu, Guanghua; Ye, Qiuxia; Liu, Jianchao

    2016-09-01

    A partial life-cycle study with zebrafish (Danio rerio) was conducted to evaluate the long-term effects of antibiotics, norfloxacin (NOR) and sulfamethoxazole (SMX). A series of bio-endpoints correlated to the growth, development, and reproduction was assessed. The results showed that the body weight and the condition factor were depressed by SMX at 200 μg/L during the growth period. Meanwhile, the activities of metabolic enzyme (ethoxyresorufin O-deethylase, EROD) and antioxidant enzymes (superoxide dismutase, SOD and catalase, CAT) were stimulated in all cases. The consequences of parental exposure to antibiotics for the next generation were also examined. The egg production of parents were depressed by the 200 μg/L NOR and SMX alone or in combination. Similarly, decreased hatching, survival, and enhanced development abnormality of the next generation also occurred after parental exposure to SMX at the highest concentration. The heartbeat however was not altered in all cases. Furthermore, there was no significant difference in the bio-endpoints between the combined and individual treatment in most cases, with the exception of lower EROD activity and egg production in the co-treatment. The results suggest that long-term exposure to NOR and SMX at environmentally relevant concentrations, individually and in a mixture, may not significantly pose a threat to the growth, development, and reproduction of zebrafish, and an adverse effect may be expected at high concentration.

  1. Should Weaning be the Start of the Reproductive Cycle in Hyper-prolific Sows? A Physiological View

    NARCIS (Netherlands)

    Kemp, B.; Soede, N.M.

    2012-01-01

    Normally, sows are in anoestrus during lactation and start their new cycle at the day of weaning. Modern hybrid primiparous sows that suckle large numbers of piglets may lose substantial amounts of body reserves during lactation. This compromises follicle development during lactation. As modern sows

  2. Morphology and Aquaporin Immunohistochemistry of the Uterine Tube of Saanen Goats (Capra hircus): Comparison Throughout the Reproductive Cycle.

    Science.gov (United States)

    Arrighi, S; Bosi, G; Frattini, S; Coizet, B; Groppetti, D; Pecile, A

    2016-06-01

    The expression of six different aquaporins (AQP1, 2, 3, 4, 5 and 9), integral membrane water channels that facilitate bi-directional passive movement of water, was investigated by immunohistochemistry in the uterine tube of pre-pubertal and adult Saanen goats (Capra hircus), comparing the different phases of the oestrous cycle. Regional morphology and secretory processes were markedly different during the goat oestrous cycle. The tested AQP molecules showed different expression patterns in comparison with already studied species. AQP1-immunoreactivity was evidenced at the endothelium of blood vessels and in nerve fibres, regardless of the tubal tract and cycle period. AQP4-immunoreactivity was shown on the lateral plasmalemma in the basal third of the epithelial cells at infundibulum and ampulla level in the cycling goats, more evidently during follicular than during luteal phase. No AQP4-immunoreactivity was noticed at the level of the isthmus region, regardless of the cycle phase. AQP5-immunoreactivity, localized at the apical surface of epithelial cells, increased from pre-puberty to adulthood. Thereafter, AQP5-immunoreactivity was prominent during the follicular phase, when it strongly decorated the apical plasmalemma of all epithelial cells at ampullary level. During luteal phase, immunoreactivity was discontinuous, being weak to strong at the apex of the secretory cells protruding into the lumen. In the isthmus region, the strongest AQP5-immunoreactivity was seen during follicular phase, with a clear localization in the apical plasmalemma of all the epithelial cells and also on the lateral plasmalemma. AQP2, 3 and 9 were undetectable all along the goat uterine tube. Likely, a collaboration of different AQP molecules sustains the fluid production in the goat uterine tube. AQP1-mediated transudation from the blood capillaries, together with permeation of the epithelium by AQP4 in the basal rim of the epithelial cells and final intervening of apical AQP5, could

  3. Reproductive cycle of Loxechinus albus (Echinodermata: Echinoidea in two areas of the Magellan Region (53ºS, 70-72ºW, Chile

    Directory of Open Access Journals (Sweden)

    Sylvia T. Oyarzún

    1999-12-01

    Full Text Available The reproductive cycle of the Chilean edible sea urchin, Loxechinus albus, was studied in two areas of the Magellan region, the Cockburn Channel (53°43´S, 70°42´W and Dawson Island (53°43´S, 72°00´W. Eleven monthly samplings were carried out from April 1996 to May 1997 in each area and samples of between 88 and 100 organisms were collected. Test diameter, total wet weight, and wet gonad weight was measured for each organism. Sex, gonad index, maturity index and gametogenic condition were estimated for each organism through histological analyses. The results indicate that L. albus in the Magellan region has an annual reproductive cycle in which the temporal sequence of different gametogenic processes can not be distinguished accurately due to the rapid and continuous gonadal recovery and gamete production after the spawning period. Although mature organisms were present most of the year, simultaneous spawning of males and females occurred from August to September in Dawson Island and from July to September in the Cockburn Channel. Gametes of those organisms that became mature after the spawning period were resorbed by nutritive phagocytes. Results from this study suggest that small-scale variability of spawning period in the Magellan region may be explained by the differences in food type and availability among areas. Our results also suggest that the Magellan region is an exception to the latitudinal pattern of spawning period reported for most of the Chilean coast. This large-scale variability may be explained by the simultaneous occurrence of low temperatures and short days during late winter and early spring.

  4. How the cladoceran heterogonic life cycle evolved--insights from gamogenetic reproduction and direct development in Cyclestherida.

    Science.gov (United States)

    Fritsch, Martin; Richter, Stefan

    2015-01-01

    Here we document the early gamogenetic development of Cyclestherida, including a characterization of the nervous system. Resting eggs in Cyclestheria are protected by an ephippium, built by the major part of the carapace. The first stages of development are enclosed in an outer chorion and an inner vitelline membrane. After shedding of the chorion, the vitelline membrane inflates and later stages are free-floating within the vitelline membrane. Only the juveniles are released from the vitelline membrane. Developmental stages of the gamogenetic direct development and of the parthenogenetic pseudo-direct development are remarkably similar in Cyclestheria, both regarding external and nervous system development. Because of this high degree of correspondence, as well as the important differences to the anamorphic development in Spinicaudata, we suggest that the developmental stages from the gamogenetic life cycle evolved directly from the parthenogenetic life cycle. This implies that resting egg development in Cladoceromorpha does not correspond directly to the resting egg development in large branchiopods. This leads us to the conclusion that the entire heterogonous life cycle in Cladoceromorpha probably evolved anew. © 2015 Wiley Periodicals, Inc.

  5. Life cycle and reproductive patterns of Triatoma rubrovaria (Blanchard, 1843) (Hemiptera: Reduviidae) under constant and fluctuating conditions of temperature and humidity.

    Science.gov (United States)

    Damborsky, Miryam P; Bar, María E; Gorla, David

    2005-01-01

    The aim of this study was to evaluate the temperature and relative humidity influence in the life cycle, mortality and fecundity patterns of Triatoma rubrovaria. Four cohorts with 60 recently laid eggs each were conformed. The cohorts were divided into two groups. In the controlled conditions group insects were maintained in a dark climatic chamber under constant temperature and humidity, whereas triatomines of the ambiental temperature group were maintained at room temperature. Average incubation time was 15.6 days in the controlled conditions group and 19.1 days in the ambiental temperature. In group controlled conditions the time from egg to adult development lasted 10 months while group ambiental temperature took four months longer. Egg eclosion rate was 99.1% and 98.3% in controlled conditions and ambiental temperature, respectively. Total nymphal mortality in controlled conditions was 52.6% whereas in ambiental temperature was 51.8%. Mean number of eggs/female was 817.6 controlled conditions and 837.1 ambiental temperature. Fluctuating temperature and humidity promoted changes in the life cycle duration and in the reproductive performance of this species, although not in the species mortality.

  6. Development of a biotin-streptavidin amplified enzyme immunoassay for oxytocin and its application during milk ejection and the reproductive cycle in the mithun (Bos frontalis).

    Science.gov (United States)

    Mondal, Mohan; Rajkhowa, Chandan; Prakash, Bukkaraya Samudram

    2006-07-01

    Oxytocin is a key hormone involved in milk ejection. It plays a key role in regulation of reproductive cyclicity in female mammals by taking part in the process of luteolysis. Determination of oxytocin is, therefore, important for studying the control of its secretion and its role in reproduction of the mithun. A simple and sufficiently sensitive enzyme immunoassay (EIA) for oxytocin determination in mithun plasma using the biotin-streptavidin amplification system and second antibody coating technique was therefore developed. Biotin was coupled to oxytocin and used to bridge between streptavidin-peroxidase and the immobilized oxytocin antiserum in a competitive assay. The EIA was conducted directly in 200 microl of unknown mithun plasma. Standards prepared in hormone-free plasma were used. The lowest detection limit was 0.5 pg/ml plasma. Plasma volumes for the EIA (50, 100, and 200 microl) did not influence the shape of standard curve, even though a drop in OD450 was seen with higher plasma volumes. A parallelism test was carried out to compare endogenous mithun oxytocin with a bovine oxytocin standard. The former showed good parallelism with the bovine standard curve. For biological validation of the assay, plasma oxytocin was measured in the blood samples collected before, during, and after milking in three mithun cows and in six non-lactating cyclic mithuns during the entire estrous cycle. A sharp release of oxytocin shortly after udder stimulation was observed. A high level of oxytocin was maintained during milking, falling sharply thereafter. The mean plasma oxytocin concentration was different on different days of the estrous cycle (P oxytocin were recorded, one at day 6 and another at day 18 of the estrous cycle. In conclusion, a simple, sufficiently sensitive and direct EIA procedure has been developed for the first time to determine plasma oxytocin levels in mithuns. Apart from being non-radioactive, the EIA procedure described here also utilizes a highly

  7. Impact of female age and male infertility on ovarian reserve markers to predict outcome of assisted reproduction technology cycles

    Directory of Open Access Journals (Sweden)

    Hsieh Kung-Chen

    2009-09-01

    Full Text Available Abstract Background This study was designed to assess the capability of ovarian reserve markers, including baseline FSH levels, baseline anti-Müllerian hormone (AMH levels, and antral follicle count (AFC, as predictors of live births during IVF cycles, especially for infertile couples with advanced maternal age and/or male factors. Methods A prospective cohort of 336 first IVF/ICSI cycles undergoing a long protocol with GnRH agonist was investigated. Patients with endocrine disorders or unilateral ovaries were excluded. Results Among the ovarian reserve tests, AMH and age had a greater area under the receiving operating characteristic curve than FSH in predicting live births. Furthermore, AMH and age were the sole predictive factors of live births for women greater than or equal to 35 years of age; while AMH was the major determinant of live births for infertile couples with absence of male factors by multivariate logistic regression analysis. However, all the studied ovarain reserve tests were not preditive of live births for women Conclusion The serum AMH levels were prognostic for pregnancy outcome for infertile couples with advanced female age or absence of male factors. The predictive capability of ovarian reserve tests is clearly influenced by the etiology of infertility.

  8. Life cycle of the multiarmed sea star Coscinasterias acutispina (Stimpson, 1862) in laboratory culture: sexual and asexual reproductive pathways.

    Science.gov (United States)

    Shibata, Daisuke; Hirano, Yoshiaki; Komatsu, Miéko

    2011-05-01

    The multiarmed sea star Coscinasterias acutispina generally has 7-10 arms and 2-5 madreporites. It is known to be able to reproduce by asexual fission, and we have previously observed that this species also has the ability to reproduce sexually; however, there has been no report until now of spawning in this species. We succeeded in establishing a long-term culture of juveniles produced by artificial fertilization. Twelve months after the completion of metamorphosis, three individuals had six arms of the same length and a madreporite. At this time, fission occurred in two of these individuals, while the remaining individual underwent fission four months later. Each sea star divided into two halves, provided with three arms each. Thereafter, four or five new arms and two or four madreporites were formed anew in each of the six daughter sea-stars, so that by 30 days after the first fission the number of arms and madreporites in each was similar to that in adults. A second fission occurred in four of these six individuals, four or five months after the first fission, and in three of them the plane of division was the same as that of the first fission. The original three individuals eventually proliferated to 12 by undergoing fission. All individuals had fully developed gonads by 1-3 months after the second fission. Some of them eventually spawned under laboratory culture, and the resulting larvae metamorphosed into juveniles. Our observations demonstrate that individuals of C. acutispina possess the potential for both sexual and asexual reproduction.

  9. Transcriptome Alterations Following Developmental Atrazine Exposure in Zebrafish Are Associated with Disruption of Neuroendocrine and Reproductive System Function, Cell Cycle, and Carcinogenesis

    Science.gov (United States)

    Freeman, Jennifer L.

    2013-01-01

    Atrazine, a herbicide commonly applied to agricultural areas and a common contaminant of potable water supplies, is implicated as an endocrine-disrupting chemical (EDC) and potential carcinogen. Studies show that EDCs can cause irreversible changes in tissue formation, decreased reproductive potential, obesity, and cancer. The U.S. Environmental Protection Agency considers an atrazine concentration of ≤ 3 ppb in drinking water safe for consumption. The specific adverse human health effects associated with a developmental atrazine exposure and the underlying genetic mechanisms of these effects are not well defined. In this study, zebrafish embryos were exposed to a range of atrazine concentrations to establish toxicity. Morphological, transcriptomic, and protein alterations were then assessed at 72h postfertilization following developmental atrazine exposure at 0, 0.3, 3, or 30 ppb. A significant increase in head length was observed in all three atrazine treatments. Transcriptomic profiles revealed 21, 62, and 64 genes with altered expression in the 0.3, 3, and 30 ppb atrazine treatments, respectively. Altered genes were associated with neuroendocrine and reproductive system development, function, and disease; cell cycle control; and carcinogenesis. There was a significant overlap (42 genes) between the 3 and 30 ppb differentially expressed gene lists, with two of these genes (CYP17A1 and SAMHD1) present in all three atrazine treatments. Increased transcript levels were translated to significant upregulation in protein expression. Overall, this study identifies genetic and molecular targets altered in response to a developmental atrazine exposure to further define the biological pathways and mechanisms of toxicity. PMID:23358194

  10. The potential of the MAGIC TOM Parental accessions to explore the genetic variability in tomato acclimation to repeated cycles of water deficit and recovery

    Directory of Open Access Journals (Sweden)

    Julie eRipoll

    2016-01-01

    Full Text Available Episodes of water deficit (WD during the crop cycle of tomato may negatively impact plant growth and fruit yield, but they may also improve fruit quality. Moreover, a moderate WD may induce a plant memory effect which is known to stimulate plant acclimation and defenses for upcoming stress episodes. The objective of this study was to analyze the positive and negative impacts of repeated episodes of WD at the plant and fruit levels. Three episodes of WD (-38 %, -45 % and -55 % of water supply followed by three periods of recovery (WD treatments, were applied to the 8 parents of the Multi-Parent Advanced Generation Inter-Cross population which offers the largest allelic variability observed in tomato. Predawn and midday water potentials, chlorophyll a fluorescence, growth and fruit quality traits (contents in sugars, acids, carotenoids and ascorbic acid (AsA were measured throughout the experiment. Important genotypic variations were observed both at the plant and fruit levels and variations in fruit and leaf traits were found not to be correlated. Overall, the WD treatments were at the origin of important osmotic regulations, reduction of leaf growth, acclimation of photosynthetic functioning, notably through an increase in the chlorophyll content and in the quantum yield of the electron transport flux until PSI acceptors (J0RE1/JABS. The effects on fruit sugar, acid, carotenoid and AsA contents on a dry matter basis ranged from negative to positive to nil depending on genotypes and stress intensity. Three small fruit size accessions were richer in AsA on a fresh matter basis, due to concentration effects. So, fruit quality was improved under WD mainly through concentration effects. On the whole, two accessions, LA1420 and Criollo appeared as interesting genetic resources, cumulating adaptive traits both at the leaf and fruit levels. Our observations show that the complexity involved in plant responses, when considering a broad range of

  11. The effect of inorganic and organic form of zinc on digestibility of nutrients in dairy cows in three stages of reproductive cycle

    Directory of Open Access Journals (Sweden)

    Marie Balabánová

    2011-01-01

    Full Text Available The aim of our experiment was to compare the effect of feeding inorganic and organic forms of zinc in premix on the coefficient of digestibility of nutrients in the feeding ration for cows in three stages of reproductive cycle – 14 d before calving and 30 and 60 d after calving. The experiment was carried out on 19 Holstein cows that were divided into two groups. A control group of nine cows designated as “Inorganic zinc form” (IZF was fed a diet supplemented with mineral premix containing inorganic form of zinc (ZnO. An experimental group of ten cows designated as “Organic zinc form” (OZF had zinc oxide replaced with zinc fixed to methionine (Khei-chelate Zn powder 15% by Kheiron. The experiment was divided into three periods - the first period lasted from 14th day before calving until 2nd day after calving, the second period lasted from 3rd day to 30th day after calving and the third period lasted from 31st day to 60th day after calving. Cows were fed the diet based on maize silage, lucerne haylage, sugar beet pulp silage, grass or lucerne hay and concentrate containing premix with either inorganic or organic zinc form. During the experiment samples of feeding ration and faeces were taken in 3 intervals, it si on 14th day before calving, on 30th day and on 60th day after calving to determine nutrients content. Digestibility of nutrients was calculated using indicator method (ash insoluble in 3 M HCl.After feeding organic forms of zinc a tendency to higher digestibility of crude protein, fat, crude fiber, nitrogen-free extracts, ash and zinc was observed in cows regardless of stage of reproductive cycle. The digestibility of the zinc and fiber were the most increased. Digestibility of zinc in OZF on 14th day before calving was higher than in IZF (P < 0.05. Feeding of organic zinc forms had downward effect only on the digestibility of copper.

  12. Characterizing Transcriptional Networks in Male Rainbow Darter (Etheostoma caeruleum) that Regulate Testis Development over a Complete Reproductive Cycle.

    Science.gov (United States)

    Bahamonde, Paulina A; McMaster, Mark E; Servos, Mark R; Martyniuk, Christopher J; Munkittrick, Kelly R

    2016-01-01

    Intersex is a condition that has been associated with exposure to sewage effluents in male rainbow darter (Etheostoma caeruleum). To better understand changes in the transcriptome that are associated with intersex, we characterized annual changes in the testis transcriptome in wild, unexposed fish. Rainbow darter males were collected from the Grand River (Ontario, Canada) in May (spawning), August (post-spawning), October (recrudescence), January (developing) and March (pre-spawning). Histology was used to determine the proportion of spermatogenic cell types that were present during each period of testicular maturation. Regression analysis determined that the proportion of spermatozoa versus spermatocytes in all stages of development (R2 ≥ 0.58) were inversely related; however this was not the case when males were in the post-spawning period. Gene networks that were specific to the transition from developing to pre-spawning stages included nitric oxide biosynthesis, response to wounding, sperm cell function, and stem cell maintenance. The pre-spawning to spawning transition included gene networks related to amino acid import, glycogenesis, Sertoli cell proliferation, sperm capacitation, and sperm motility. The spawning to post-spawning transition included unique gene networks associated with chromosome condensation, ribosome biogenesis and assembly, and mitotic spindle assembly. Lastly, the transition from post-spawning to recrudescence included gene networks associated with egg activation, epithelial to mesenchymal transition, membrane fluidity, and sperm cell adhesion. Noteworthy was that there were a significant number of gene networks related to immune system function that were differentially expressed throughout reproduction, suggesting that immune network signalling has a prominent role in the male testis. Transcripts in the testis of post-spawning individuals showed patterns of expression that were most different for the majority of transcripts

  13. Prolonged Increase in the Sensitivity of the Posterior Ventral Tegmental Area to the Reinforcing Effects of Ethanol following Repeated Exposure to Cycles of Ethanol Access and Deprivation

    OpenAIRE

    Rodd, Zachary A.; Bell, Richard L.; McQueen, Victoria K.; Davids, Michelle R.; Hsu, Cathleen C.; Murphy, James M.; Li, Ting-Kai; Lumeng, Lawrence; McBride, William J.

    2005-01-01

    The posterior ventral tegmental area (VTA) is a neuroanatomical substrate mediating the reinforcing effects of ethanol in rats. Repeated alcohol deprivations produce robust ethanol intakes of alcohol-preferring (P) rats during relapse and increase the reinforcing effects of oral alcohol self-administration. The objective of this study was to test the hypothesis that alcohol drinking and repeated alcohol deprivations will increase the reinforcing effects of ethanol within the posterior VTA of ...

  14. Centrosome structure and function is altered by chloral hydrate and diazepam during the first reproductive cell cycles in sea urchin eggs

    Science.gov (United States)

    Schatten, H.; Chakrabarti, A.

    1998-01-01

    This paper explores the mode of action of the tranquillizers chloral hydrate and diazepam during fertilization and mitosis of the first reproductive cell cycles in sea urchin eggs. Most striking effects of these drugs are the alteration of centrosomal material and the abnormal microtubule configurations during exposure and after recovery from the drugs. This finding is utilized to study the mechanisms of centrosome compaction and decompaction and the dynamic configurational changes of centrosomal material and its interactions with microtubules. When 0.1% chloral hydrate or 350-750 microM diazepam is applied at specific phases during the first cell cycle of sea urchin eggs, expanded centrosomal material compacts at distinct regions and super-compacts into dense spheres while microtubules disassemble. When eggs are treated before pronuclear fusion, centrosomal material aggregates around each of the two pronuclei while microtubules disappear. Upon recovery, atypical asters oftentimes with multiple foci are formed from centrosomal material surrounding the pronuclei which indicates that the drugs have affected centrosomal material and prevent it from functioning normally. Electron microscopy and immunofluorescence studies with antibodies that routinely stain centrosomes in sea urchin eggs (4D2; and Ah-6) depict centrosomal material that is altered when compared to control cells. This centrosomal material is not able to reform normal microtubule patterns upon recovery but will form multiple asters around the two pronuclei. When cells are treated with 0.1% chloral hydrate or 350-750 microM diazepam during mitosis, the bipolar centrosomal material becomes compacted and aggregates into multiple dense spheres while spindle and polar microtubules disassemble. With increased incubation time, the smaller dense centrosome particles aggregate into bigger and fewer spheres. Upon recovery, unusual irregular microtubule configurations are formed from centrosomes that have lost their

  15. Disentangling facilitation along the life cycle: impacts of plant-plant interactions at vegetative and reproductive stages in a Mediterranean forb

    Directory of Open Access Journals (Sweden)

    Ana I. García-Cervigón

    2016-02-01

    Full Text Available Facilitation enables plants to improve their fitness in stressful environments. The overall impact of plant-plant interactions on the population dynamics of protégées is the net result of both positive and negative effects that may act simultaneously along the plant life cycle, and depends on the environmental context. This study evaluates the impact of the nurse plant Juniperus sabina on different stages of the life cycle of the forb Helleborus foetidus. Growth, number of leaves, flowers, carpels and seeds per flower were compared for 240 individuals collected under nurse canopies and in open areas at two sites with contrasting stress levels. Spatial associations with nurse plants and age structures were also checked. A structural equation model was built to test the effect of facilitation on fecundity, accounting for sequential steps from flowering to seed production. The net impact of nurse plants depended on a combination of positive and negative effects on vegetative and reproductive variables. Although nurse plants caused a decrease in flower production at the low-stress site, their net impact there was neutral. In contrast, at the high-stress site the net outcome of plant-plant interactions was positive due to an increase in effective recruitment, plant density, number of viable carpels per flower and fruit set under nurse canopies. The naturally lower rates of secondary growth and flower production at the high-stress site were compensated by the net positive impact of nurse plants here. Our results emphasize the need to evaluate entire processes and not only final outcomes when studying plant-plant interactions.

  16. Macrobenthic physiological responses to environmental fluctuations: the reproductive cycle and enzymatic polymorphism of a eurybathic sea-urchin on the northwestern Mediterranean continental shelf and slope

    Science.gov (United States)

    Féral, Jean-Pierre; Ferrand, Jean-Guy; Guille, Alain

    1990-09-01

    Two hundred and twenty-seven sea-urchins, Brissopsis lyrifera, were collected in the Gulf of Lions between 60 and ca 1000 m depth, over a21/2 year period. The reproductive cycle was found to be independent of depth. Males and females were sexually mature at the end of summer. After a period of gonadal rest during winter, gametogenesis resumed at the beginning of spring. Specific enzymatic reactions on gut extracts, after PAA-electrophoresis, indicated that B. lyrifera is not a very polymorphic species and is generally homozygotic at the tested loci, except for esterases. Individual regrouping (discriminant factorial analysis) did not appear to be sensitive to the depth factor. On the contrary, a relationship between zymogrammes of the digestive tube and the sampling season was enhanced when sex and maturation stage were considered (main concerned activities: alkaline phosphatase ALK 1 and α-amylase AMY 1 and AMY 2), especially for females. These results indicate that enzymatic activities may be seasonal. They also indicate metabolic differences dependent upon the sex in somatic tissues, on one hand, and depending on environmental fluctuations on the other. Biological cycles are seasonal in the Mediterranean Sea, to 1000 m. In the case of B. lyrifera, a relationship could be established between flux increases of sediment carbon and sterols in winter and the beginning of gametogenesis. It is concluded that physiological signals, studied at different depths, would permit us to appreciate biological components of the margin ecosystem dynamics. This will also help define the place of life in the general oceanic fluxes (matter and energy).

  17. Disentangling Facilitation Along the Life Cycle: Impacts of Plant–Plant Interactions at Vegetative and Reproductive Stages in a Mediterranean Forb

    Science.gov (United States)

    García-Cervigón, Ana I.; Iriondo, José M.; Linares, Juan C.; Olano, José M.

    2016-01-01

    Facilitation enables plants to improve their fitness in stressful environments. The overall impact of plant–plant interactions on the population dynamics of protégées is the net result of both positive and negative effects that may act simultaneously along the plant life cycle, and depends on the environmental context. This study evaluates the impact of the nurse plant Juniperus sabina on different stages of the life cycle of the forb Helleborus foetidus. Growth, number of leaves, flowers, carpels, and seeds per flower were compared for 240 individuals collected under nurse canopies and in open areas at two sites with contrasting stress levels. Spatial associations with nurse plants and age structures were also checked. A structural equation model was built to test the effect of facilitation on fecundity, accounting for sequential steps from flowering to seed production. The net impact of nurse plants depended on a combination of positive and negative effects on vegetative and reproductive variables. Although nurse plants caused a decrease in flower production at the low-stress site, their net impact there was neutral. In contrast, at the high-stress site the net outcome of plant–plant interactions was positive due to an increase in effective recruitment, plant density, number of viable carpels per flower, and fruit set under nurse canopies. The naturally lower rates of secondary growth and flower production at the high-stress site were compensated by the net positive impact of nurse plants here. Our results emphasize the need to evaluate entire processes and not only final outcomes when studying plant–plant interactions. PMID:26904086

  18. Disentangling Facilitation Along the Life Cycle: Impacts of Plant-Plant Interactions at Vegetative and Reproductive Stages in a Mediterranean Forb.

    Science.gov (United States)

    García-Cervigón, Ana I; Iriondo, José M; Linares, Juan C; Olano, José M

    2016-01-01

    Facilitation enables plants to improve their fitness in stressful environments. The overall impact of plant-plant interactions on the population dynamics of protégées is the net result of both positive and negative effects that may act simultaneously along the plant life cycle, and depends on the environmental context. This study evaluates the impact of the nurse plant Juniperus sabina on different stages of the life cycle of the forb Helleborus foetidus. Growth, number of leaves, flowers, carpels, and seeds per flower were compared for 240 individuals collected under nurse canopies and in open areas at two sites with contrasting stress levels. Spatial associations with nurse plants and age structures were also checked. A structural equation model was built to test the effect of facilitation on fecundity, accounting for sequential steps from flowering to seed production. The net impact of nurse plants depended on a combination of positive and negative effects on vegetative and reproductive variables. Although nurse plants caused a decrease in flower production at the low-stress site, their net impact there was neutral. In contrast, at the high-stress site the net outcome of plant-plant interactions was positive due to an increase in effective recruitment, plant density, number of viable carpels per flower, and fruit set under nurse canopies. The naturally lower rates of secondary growth and flower production at the high-stress site were compensated by the net positive impact of nurse plants here. Our results emphasize the need to evaluate entire processes and not only final outcomes when studying plant-plant interactions.

  19. The Mediterranean evergreen Quercus ilex and the semi-deciduous Cistus albidus differ in their leaf gas exchange regulation and acclimation to repeated drought and re-watering cycles.

    Science.gov (United States)

    Galle, Alexander; Florez-Sarasa, Igor; Aououad, Hanan El; Flexas, Jaume

    2011-10-01

    Plants may exhibit some degree of acclimation after experiencing drought, but physiological adjustments to consecutive cycles of drought and re-watering (recovery) have scarcely been studied. The Mediterranean evergreen holm oak (Q. ilex) and the semi-deciduous rockrose (C. albidus) showed some degree of acclimation after the first of three drought cycles (S1, S2, and S3). For instance, during S2 and S3 both species retained higher relative leaf water contents than during S1, despite reaching similar leaf water potentials. However, both species showed remarkable differences in their photosynthetic acclimation to repeated drought cycles. Both species decreased photosynthesis to a similar extent during the three cycles (20-40% of control values). However, after S1 and S2, photosynthesis recovered only to 80% of control values in holm oak, due to persistently low stomatal (g(s)) and mesophyll (g(m)) conductances to CO(2). Moreover, leaf intrinsic water use efficiency (WUE) was kept almost constant in this species during the entire experiment. By contrast, photosynthesis of rockrose recovered almost completely after each drought cycle (90-100% of control values), while the WUE was largely and permanently increased (by 50-150%, depending on the day) after S1. This was due to a regulation which consisted in keeping g(s) low (recovering to 50-60% of control values after re-watering) while maintaining a high g(m) (even exceeding control values during re-watering). While the mechanisms to achieve such particular regulation of water and CO(2) diffusion in leaves are unknown, it clearly represents a unique acclimation feature of this species after a drought cycle, which allows it a much better performance during successive drought events. Thus, differences in the photosynthetic acclimation to repeated drought cycles can have important consequences on the relative fitness of different Mediterranean species or growth forms within the frame of climate change scenarios.

  20. Maternal effects on progeny size, number and body color in the desert locust, Schistocerca gregaria: Density- and reproductive cycle-dependent variation.

    Science.gov (United States)

    Maeno, Koutaro; Tanaka, Seiji

    2008-06-01

    The effects of rearing density and maternal age on the progeny size, number and coloration of the desert locust, Schistocerca gregaria, were investigated. Isolated-reared females deposited smaller, but more eggs than crowd-reared females. The former produced smaller and more eggs with age, whereas the latter showed a tendency to produce larger and fewer eggs over time. A similar tendency was also observed with virgin females, indicating that mating or the presence of males was not important. The first egg pod produced by each mated crowd-reared female contained significantly smaller and more eggs than did the subsequent egg pods. The former often produced many green hatchlings (0-100%) characteristic of solitarious forms, whereas the egg pods deposited after the first pod produced predominantly black hatchlings typical of gregarious forms. Adults were highly sensitive to a shift in rearing density and quickly modified the quality and quantity of their progeny depending on the density encountered. The number of eggs per pod was influenced not only by the mother's rearing density but also by rearing density of the grandmother. The present results demonstrated that the characteristics of progeny are influenced not only by the crowding conditions experienced by the mother and grandmother but also by the mother's reproductive cycle.

  1. 年轻女性重复人工流产生殖健康状况及心理行为调查研究%Reproductive health status in adolescents underwent repeated abortion and their psychosocial behavioral status

    Institute of Scientific and Technical Information of China (English)

    王建梅; 杨华; 张钰; 李奕; 魏振河

    2010-01-01

    Objective To study the reproductive health status in adolescents underwent repeated abortion and their psychosocial behavioral status and to understand their demanding on the knowledge of contraception, so as to provide suggestions on post abortion care. Methods From July ,2007 to May,2008,400 unmarried adolescents who visited doctors and met the following criteria were recruited in the study:①Younger than 24 years old;②Had artificial abortion at least once;③Have been pregnant for 5-10 weeks and asked for artificial abortion. Data were collected through symptom checklist 90 (SCL-90)and anonymous reproductive health questionnaire. The situation of reproductive tract infections (RTIs) were detected through gynecological examination and laboratory tests.The data was analyzed by SPSS 11.5 statistical software. Results The mean age of the subjects was 21. 18 ±2. 46 years. The mean time of previous artificial abortion was 1.96 ± 1.44,with 52% of ≥2 times. Aged less than 20 years old at the first abortion,having sex more than 3 times per week,more than 2 sex partners,and history of painless abortion were associated with repeated abortion in unmarried adolescents. The SCL-90 scores showed that the subjects had higher score of depression, terror, psychiatric symptoms, somatization, interpersonal sensitivity,anxiety and hostility factors than normal population (P 3次/周、性伴侣数2个以上以及前次人工流产选择无痛人工流产是未婚年轻女性重复多次妊娠的影响因素.心理健康状况分析:研究组抑郁、恐怖、精神病性、躯体化、人际关系、焦虑和敌对性的因子分值均高于全国常模,差异均有统计学意义(P均2次、首次性行为年龄≤18岁、既往有生殖道感染病史、性生活频率多于3次/周、多性伴特别是同时多性伴、性生活卫生差为生殖道感染的危险因素.结论 重复人工流产年轻女性存在心理、生理多方面生殖健康问题,生殖避孕知

  2. Reproductive performance of second parity sows: relations with subsequent reproduction

    NARCIS (Netherlands)

    Hoving, L.L.; Soede, N.M.; Graat, E.A.M.; Feitsma, H.; Kemp, B.

    2011-01-01

    The objective of this study was to determine relations between reproductive performance, i.e. being a repeat breeder and litter size, in 2nd parity and reproductive performance in later parities. In addition, relations between the 1st and 2nd parity litter size and litter size in later parities were

  3. Morfometria testicular durante o ciclo reprodutivo de Dendropsophus minutus (Peters (Anura, Hylidae Testicular morphometry during the reproductive cycle of Dendropsophus minutus (Peters (Anura, Hylidae

    Directory of Open Access Journals (Sweden)

    Lia R. de S. Santos

    2007-03-01

    Full Text Available Este estudo descreve o ciclo reprodutivo de machos de Dendropsophus minutus (Peters, 1872 com base na análise da morfometria testicular e a correlação com parâmetros climáticos. Cinqüenta indivíduos foram coletados em São José do Rio Preto, São Paulo. Após as análises macroscópicas, os testículos foram encaminhados à rotina histológica, fixados com Bouin e incluídos em historesina. Cortes de 2 µm foram corados com azul de toluidina 1% e observados ao microscópio. Testículos de D. minutus são órgãos pequenos (comprimento 1,90 ± 0,13 mm, esbranquiçados, com forma oval e encontrados na cavidade abdominal. Estão localizados na extremidade cranial dos rins e apresentam assimetria quanto a sua posição. Estatisticamente não há variação intra-individual no comprimento e no peso dos testículos, bem como na área e diâmetro dos lóculos seminíferos. Quanto à histologia testicular, foi possível identificar ao longo do ano nos lóculos seminíferos, todos os tipos celulares da linhagem espermatogênica, caracterizando uma gametogênese contínua, corroborada por fatores ecológicos e comportamentais. Informações sobre a morfometria testicular e ciclo reprodutivo tem importante valor biológico para anuros de regiões neotropicais.This study describes the male reproductive cycle of Dendropsophus minutus (Peters, 1872 based on testicular morphometric analysis, related to climatic conditions. Fifty individuals where collected in São José do Rio Preto, São Paulo. After macroscopic analysis, the testes were submitted to histological routine, fixed with Bouin, embedded in historesin. Sections of 2 µm were stained with 1% toluidine blue and observed to the microscope. The testes of D. minutus are small organs (length 1.90 ± 0.13 mm, whitish, oviform and found in the abdominal cavity. They are located in the cranial extremity of the kidneys and present asymmetry as far as position. According to statistical analyses, there

  4. Effect of Melatonin on the Outcome of Assisted Reproductive Technique Cycles in Women with Diminished Ovarian Reserve: A Double-Blinded Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Bahia Namavar Jahromi

    2017-01-01

    Full Text Available Diminished ovarian reserve (DOR significantly decreases the success rate of the assisted reproductive technique (ART. In this study, we assessed the effect of melatonin on the ART outcomes in women with DOR. A double-blinded, randomized, clinical trial was performed on 80 women with DOR as a pilot study in Shiraz, between 2014 and 2015. DOR was defined as the presence of 2 of the following 3 criteria: 1 anti-Müllerian hormone ≤1, 2 folliclestimulating hormone ≥10, and 3 bilateral antral follicle count ≤6. The women received 3 mg/d melatonin or a placebo since the fifth day of one cycle prior to gonadotropin stimulation and continued the treatment up to the time of ovum pickup. The ART outcomes were compared between the groups using SPSS software. Finally, there were 32 women in the case and 34 in the placebo groups. The mean age and basal ovarian reserve test were the same between the groups. The serum estradiol level on the triggering day was significantly higher in the case group (P=0.005. The mean number of MII oocytes was higher in the case group, but the difference did not reach statistical significance. Number of the patients who had mature MII oocytes (P=0.014, top-quality embryos with grade 1 (P=0.049, and embryos with grades 1 and 2 (P=0.014 was higher among the women who received melatonin. However, the other ART outcomes were not different between the groups. The serum estradiol level was higher and more women with DOR had good-quality oocytes and embryos after receiving melatonin; however, no other outcome was different between the case and control groups. Trial Registration Number: IRCT2014041417264N1

  5. Effect of Melatonin on the Outcome of Assisted Reproductive Technique Cycles in Women with Diminished Ovarian Reserve: A Double-Blinded Randomized Clinical Trial

    Science.gov (United States)

    Jahromi, Bahia Namavar; Sadeghi, Sara; Alipour, Shohreh; Parsanezhad, Mohammad Ebrahim; Alamdarloo, Shaghayegh Moradi

    2017-01-01

    Diminished ovarian reserve (DOR) significantly decreases the success rate of the assisted reproductive technique (ART). In this study, we assessed the effect of melatonin on the ART outcomes in women with DOR. A double-blinded, randomized, clinical trial was performed on 80 women with DOR as a pilot study in Shiraz, between 2014 and 2015. DOR was defined as the presence of 2 of the following 3 criteria: 1) anti-Müllerian hormone ≤1, 2) follicle-stimulating hormone ≥10, and 3) bilateral antral follicle count ≤6. The women received 3 mg/d melatonin or a placebo since the fifth day of one cycle prior to gonadotropin stimulation and continued the treatment up to the time of ovum pickup. The ART outcomes were compared between the groups using SPSS software. Finally, there were 32 women in the case and 34 in the placebo groups. The mean age and basal ovarian reserve test were the same between the groups. The serum estradiol level on the triggering day was significantly higher in the case group (P=0.005). The mean number of MII oocytes was higher in the case group, but the difference did not reach statistical significance. Number of the patients who had mature MII oocytes (P=0.014), top-quality embryos with grade 1 (P=0.049), and embryos with grades 1 and 2 (P=0.014) was higher among the women who received melatonin. However, the other ART outcomes were not different between the groups. The serum estradiol level was higher and more women with DOR had good-quality oocytes and embryos after receiving melatonin; however, no other outcome was different between the case and control groups. Trial Registration Number: IRCT2014041417264N1 PMID:28293053

  6. Effet de Panicum maximum sur la productivité des femelles primipares durant le cycle de reproduction chez le cobaye (Cavia porcellus L.

    Directory of Open Access Journals (Sweden)

    Danho, M.

    2012-01-01

    Full Text Available Effect of Panicum maximum on Productivity of Primiparous Females during Reproduction Cycle in Guinea Pigs (Cavia porcellus L.. In Ivory Coast, Guinea pigs reared for meat (Cavia porcellus L. are mainly fed with Panicum maximum. To assess the effect of the latter during pregnancy and lactation (RC of these animals, primiparous dams were fed ad libitum, Panicum maximum alone during the RC (MOD1 or associated with pellets for rabbits during lactation (MOD2, or associated with pellets for rabbits during the last part of the pregnancy period and the lactation (MOD3, or associated with pellets for rabbits during the entire RC (MOD4. The number of corpora lutea per female was 1.3 ± 0.5 and 2.0 ± 0.0 respectively for MOD1 and MOD4. No pre-embryonic mortality was recorded. The mean weight of the young guinea pigs of MOD1 (54.7 ± 10. g was only 55% of that of MOD4 (98.6 ± 13.6 g. At weaning, the average weight gain of young guinea pigs of MOD1 (40.5 ± 22.2 g represented a third of those obtained with other diets that did not significantly differ. At the end of RC, the weight gain of dams was 17 ± 13.3% for MOD1 compared to 50% for MOD2, MOD3 and MOD4. Feeding Panicum maximum alone induces chronic malnutrition which in turn is responsible of the low ovulation rate and reduced growth in guinea pig breeding.

  7. Características histológicas del ciclo reproductivo de Euvola ziczac (Linnaeu (Pectinidae, Bivalvia del litoral sur-sudeste del Brasil Histological characteristics of the reproductive cycle of Euvola ziczac (Pectinidae, Bivalvia from south-southern Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Borzone

    2003-12-01

    Full Text Available Scallops were collected from beds at 30 to 40 m depth on the south-southern inner continental shelf of Brazil for histological gonadal characterization of the reproductive cycle. This hermaphroditic scallop was an important shellfish resource during 70-80 decade, with maximal annual landings of 8,845 tons, but now is depleted. Results shows that reproduction is continuous, with two major spawning periods, the first during end of summer and throughout autumn, and the second during winter and beginning of spring. A characteristic phenomenon of oocyte atresia, with maximal incidences in September is described. This phenomenon, followed by the mature oocyte resorption and new oocyte proliferation and maturation, was related to the lack of spawning stimulation. A semi-annual thermal cycle on the bottom water due to the South Atlantic Central Water intrusion seems to be the principal reproductive cycle controller. Fluctuations in landings registered since the beginning of the fishery may be partly related to oceanographic variations.

  8. Source parameters of a M4.8 and its accompanying repeating earthquakes off Kamaishi, NE Japan: Implications for the hierarchical structure of asperities and earthquake cycle

    Science.gov (United States)

    Uchida, N.; Matsuzawa, T.; Ellsworth, W.L.; Imanishi, K.; Okada, T.; Hasegawa, A.

    2007-01-01

    We determine the source parameters of a M4.9 ?? 0.1 'characteristic earthquake' sequence and its accompanying microearthquakes at ???50 km depth on the subduction plate boundary offshore of Kamaishi, NE Japan. The microearthquakes tend to occur more frequently in the latter half of the recurrence intervals of the M4.9 ?? 0.1 events. Our results show that the microearthquakes are repeating events and they are located not only around but also within the slip area for the 2001 M4.8 event. From the hierarchical structure of slip areas and smaller stress drops for the microearthquakes compared to the M4.8 event, we infer the small repeating earthquakes rupture relatively weak patches in and around the slip area for the M4.8 event and their activity reflects a stress concentration process and/or change in frictional property (healing) at the area. We also infer the patches for the M4.9 ?? 0.1 and other repeating earthquakes undergo aseismic slip during their interseismic period. Copyright 2007 by the American Geophysical Union.

  9. Reproductive performance of donor mares subsequent to eFSH treatment in early vernal transition: Comparison between the first, second, and mid-season estrous cycles of the breeding season.

    Science.gov (United States)

    Raz, Tal; Hunter, Barbara; Carley, Sylvia; Card, Claire

    2009-11-01

    The objective was to compare the reproductive performances associated with the first (Cycle-1), second (Cycle-2), and mid-season (MS-Cycle) ovulations of the breeding season in donor mares that were treated with equine-FSH (eFSH) in the early vernal transition. Mares (n=15) kept under ambient light were examined ultrasonographically per-rectum starting January 30. When an ovarian follicle > or =25mm in diameter was detected, twice daily eFSH treatments were initiated. The eFSH treatments ceased when a follicle > or =35mm was detected, and 36h later hCG was administered. Thereafter, mares were artificially inseminated every 48h until ovulation (Day 0). Trans-cervical embryo recovery attempts were performed on Day 8, and subsequently PGF2alpha was administered. Equine FSH was not administered in the subsequent estrous cycles. In Cycle-2 and in the MS-Cycle, hCG was administered when a follicle > or =35mm was detected; breeding, embryo recovery, and PGF2alpha administration, were similar to Cycle-1. Mares had an untreated estrous cycle (no treatment or breeding) between Cycle-2 and the MS-Cycle. All mares developed follicle(s) > or =35mm after 4.9+/-0.6 days of eFSH treatment, and subsequently ovulations occurred; mean (95% CI) interval from treatment initiation to ovulation was 7.9 (6.5-9.3) days. The number of preovulatory follicles (> or =30mm) at the time of hCG administration (Cycle-1: 2.2+/-0.3 compared with Cycle-2: 1.0+/-0 compared with MS-Cycle: 1.1+/-0.1 follicles), and the number of ovulations (2.5+/-0.4 compared with 1.0+/-0 compared with 1.1+/-0.1 ovulations) were greater (phormonal environment (estradiol-17beta and progesterone). A prolonged IOI (>21 days) was recorded in 7 of 15 mares following the Cycle-1 ovulation, but not subsequently. In conclusion, eFSH treatment of vernal transitional donor mares stimulated ovulation within only few days of treatment, and the following embryo recovery rate was at least as good as in the subsequent estrous cycles

  10. Estresse, ciclo reprodutivo e sensibilidade cardíaca às catecolaminas Stress, reproductive cycle and cardiac sensitivity to cathecolamines

    Directory of Open Access Journals (Sweden)

    Ana Paula Tanno

    2002-09-01

    íacas observadas na espécie humana após exposição à água e à natação.Stress is an organic answer to aversive stimulus or unknown situations to provide the adaptation of host to the new condition. The stressor can be a physical, chemical, emotional and social agent. Different stressors are present in human daily life and can be involved in degenerative diseases and lead to a fast aging process disturbing the body physiology. The main mediators of the stress reaction are the catecholamines (norepinephrine and epinephrine released by the sympathetic nervous system and by the adrenal medulla, and the glucocorticoids released by the adrenal cortex. The catecholamines and glucocorticoids act in the cells and tissues inducing adaptive changes in order to protect the organism and allow its survival. This response to stressors can be modified by the host and stressor characteristics. Among the host ones, age, gender, and in females, the reproductive cycle are relevant. The variations in the levels of sexual steroids estradiol and progesterone, related to the reproductive cycle, modulate the secretion of CRH, ACTH and glucocorticoids during the stress reaction and are involved in the different responses between men and women. Many studies have shown that the exposure to stressors may induce alterations in the sensitivity to catecholamines in the heart, which are related to adaptive processes. These alterations include changes in the activity of the metabolizing system of catecholamines, in the affinity or number of adrenoceptors, in the coupling between the receptor and G protein, and in enzymes mediating intracellular processes after the receptor activation. The study of these alterations may be helpful to the understanding of the cardiac effects of the water activities and swimming in humans.

  11. The politics of reproduction.

    Science.gov (United States)

    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

  12. Methylation at global LINE-1 repeats in human blood are affected by gender but not by age or natural hormone cycles.

    Directory of Open Access Journals (Sweden)

    Osman El-Maarri

    Full Text Available Previously, we reported on inter-individual and gender specific variations of LINE-1 methylation in healthy individuals. In this study, we investigated whether this variability could be influenced by age or sex hormones in humans. To this end, we studied LINE-1 methylation in vivo in blood-derived DNA from individuals aged 18 to 64 years and from young healthy females at various hormone levels during the menstrual cycle. Our results show that no significant association with age was observed. However, the previously reported increase of LINE-1 methylation in males was reconfirmed. In females, although no correlation between LINE-1 or Alu methylation and hormone levels was observed, a significant stable individual specific level of methylation was noted. In vitro results largely confirmed these findings, as neither estrogen nor dihydrotestosterone affected LINE-1 or Alu methylation in Hek293T, HUVEC, or MDA-kb2 cell lines. In contrast, a decrease in methylation was observed in estrogen-treated T47-Kbluc cell lines strongly expressing estrogen receptor. The very low expression of estrogen receptor in blood cells could explain the observed insensitivity of methylation at LINE-1 to natural hormonal variations in females. In conclusion, neither natural cycle of hormones nor age has a detectable effect on the LINE-1 methylation in peripheral blood cells, while gender remains an important factor.

  13. Deployment Repeatability

    Science.gov (United States)

    2016-04-01

    controlled to great precision, but in a Cubesat , there may be no attitude determination at all. Such a Cubesat might treat sun angle and tumbling rates as...could be sensitive to small differences in motor controller timing. In these cases, the analyst might choose to model the entire deployment path, with...knowledge of the material damage model or motor controller timing precision. On the other hand, if many repeated and environmentally representative

  14. Three-year breeding cycle of rainbow trout (Oncorhynchus mykiss fed a plant-based diet, totally free of marine resources: consequences for reproduction, fatty acid composition and progeny survival.

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    Viviana Lazzarotto

    Full Text Available Terrestrial plant resources are increasingly used as substitutes for fish meal and fish oil in fish feed in order to reduce the reliance of aquaculture on marine fishery resources. Although many studies have been conducted to assess the effects of such nutritional transition, no whole breeding cycles of fish fed diets free from marine resources has been reported to date. We therefore studied the reproductive performance of trout after a complete cycle of breeding while consuming a diet totally devoid of marine ingredients and thus of n-3 long chain polyunsaturated fatty acids (n-3 LC-PUFAs that play a major role in the formation of ova. Two groups of female rainbow trout were fed from first feeding either a commercial diet (C, marine and plant ingredients, or a 100% plant-based diet (V, blend of plant proteins and vegetable oils. Livers, viscera, carcasses and ova were sampled at spawning and analyzed for lipids and fatty acids. Although the V-diet was devoid of n-3 LC-PUFAs, significant amounts of EPA and DHA were found in livers and ova, demonstrating efficient bioconversion of linolenic acid and selective orientation towards the ova. Some ova were fertilized to assess the reproductive performance and offspring survival. We observed for the first time that trout fed a 100% plant-based diet over a 3-year breeding cycle were able to produce ova and viable alevins, although the ova were smaller. The survival of offspring from V-fed females was lower (-22% at first spawning, but not at the second. Our study showed that, in addition to being able to grow on a plant-based diet, rainbow trout reared entirely on such a diet can successfully produce ova in which neo-synthesized n-3 LC-PUFAs are accumulated, leading to viable offspring. However, further adjustment of the feed formula is still needed to optimize reproductive performance.

  15. Tuberal hypothalamic expression of the glial intermediate filaments, glial fibrillary acidic protein and vimentin across the turkey hen (Meleagris gallopavo) reproductive cycle: Further evidence for a role of glial structural plasticity in seasonal reproduction.

    Science.gov (United States)

    Steinman, Michael Q; Valenzuela, Anthony E; Siopes, Thomas D; Millam, James R

    2013-11-01

    Glia regulate the hypothalamic-pituitary-gonadal (HPG) axis in birds and mammals. This is accomplished mechanically by ensheathing gonadotrophin-releasing hormone I (GnRH) nerve terminals thereby blocking access to the pituitary blood supply, or chemically in a paracrine manner. Such regulation requires appropriate spatial associations between glia and nerve terminals. Female turkeys (Meleagris gallopavo) use day length as a primary breeding cue. Long days activate the HPG-axis until the hen enters a photorefractory state when previously stimulatory day lengths no longer support HPG-axis activity. Hens must then be exposed to short days before reactivation of the reproductive axis occurs. As adult hens have discrete inactive reproductive states in addition to a fertile state, they are useful for examining the glial contribution to reproductive function. We immunostained tuberal hypothalami from short and long-day photosensitive hens, plus long-day photorefractory hens to examine expression of two intermediate filaments that affect glial morphology: glial fibrillary acidic protein (GFAP) and vimentin. GFAP expression was drastically reduced in the central median eminence of long day photosensitive hens, especially within the internal zone. Vimentin expression was similar among groups. However, vimentin-immunoreactive fibers abutting the portal vasculature were significantly negatively correlated with GFAP expression in the median eminence, which is consistent with our hypothesis for a reciprocal relationship between GFAP and vimentin expression. It appears that up-regulation of GFAP expression in the central median eminence of turkey hens is associated with periods of reproductive quiescence and that photofractoriness is associated with the lack of a glial cytoskeletal response to long days.

  16. Molecular cloning and expression analysis of dmrt1 and sox9 during gonad development and male reproductive cycle in the lambari fish, astyanax altiparanae

    NARCIS (Netherlands)

    Adolfi, Mateus C.; Carreira, Ana C O; Jesus, Lázaro W O; Bogerd, Jan; Funes, Rejane M.; Schartl, Manfred; Sogayar, Mari C.; Borella, Maria I.

    2015-01-01

    Background: The dmrt1 and sox9 genes have a well conserved function related to testis formation in vertebrates, and the group of fish presents a great diversity of species and reproductive mechanisms. The lambari fish (Astyanax altiparanae) is an important Neotropical species, where studies on molec

  17. Molecular cloning and expression analysis of dmrt1 and sox9 during gonad development and male reproductive cycle in the lambari fish, astyanax altiparanae

    NARCIS (Netherlands)

    Adolfi, Mateus C.; Carreira, Ana C O; Jesus, Lázaro W O; Bogerd, Jan|info:eu-repo/dai/nl/098250531; Funes, Rejane M.; Schartl, Manfred; Sogayar, Mari C.; Borella, Maria I.

    2015-01-01

    Background: The dmrt1 and sox9 genes have a well conserved function related to testis formation in vertebrates, and the group of fish presents a great diversity of species and reproductive mechanisms. The lambari fish (Astyanax altiparanae) is an important Neotropical species, where studies on

  18. Physiologie de la reproduction = Physiology of reproduction

    OpenAIRE

    Legendre, Marc; JALABERT, B.

    1988-01-01

    Apart from a few species on which specific studies have been conducted (e.g. on the sexual cycle), most research on the physiology of reproduction in African inland waters fishes deals with four families : Cichlidae, Mugilidae, Clariidae and Anguillidae, due to their economic importance in fisheries and fishiculture. A detailed review of date on these four families is given after a brief summary of general knowledge concerning Teleostean fishes

  19. The impact of in situ methotrexate injection after transvaginal ultrasound-guided aspiration of ovarian endometriomas on ovarian response and reproductive outcomes during IVF-cycles

    Directory of Open Access Journals (Sweden)

    H.E. Shawki

    2012-06-01

    Conclusion(s: In situ methotrexate injection after transvaginal ultrasound-guided aspiration was a simple, safe and successful method for treating ovarian endometriomas with minimal effects on ovarian response. Short term effects on reproductive outcomes, risk of fetal loss or anomaly were minimal. Six months was enough as washout period of the drug prior to conception and was advisable to prevent the small chance of chromosomal abnormalities in the offspring.

  20. The effect of peri-implantation administration of uterine relaxing agents in assisted reproduction treatment cycles: a systematic review and meta-analysis.

    Science.gov (United States)

    Khairy, Mohammed; Dhillon, Rima K; Chu, Justin; Rajkhowa, Madhurima; Coomarasamy, Arri

    2016-04-01

    Sub-endometrial junctional zone peristalsis is increased by ovarian stimulation and traumatic embryo transfer, and is linked with decreased implantation and pregnancy rates in assisted reproduction treatments. Various agents have been used to inhibit uterine hyper-peristalsis at the time of embryo transfer with conflicting results. This systematic review aimed to identify if uterine relaxants administered in the peri-implantation period during assisted reproduction treatments could improve pregnancy outcomes through literature search with no language restrictions. The review reports on 3546 patients in 17 randomized controlled trials published between 1993 and 2014. Women undergoing assisted reproduction techniques who either received a uterine relaxant agent in the peri-implantation period versus placebo or no treatment were included. Primary outcome was live birth rate. The meta-analyses did not show statistically significant benefit of any uterine relaxing agents on live birth rate. Other meta-analyses did not show a significant effect on the clinical pregnancy, spontaneous abortion, ectopic pregnancy and multiple pregnancy rate. Most of the included studies were of low quality and lacked significant power to detect minimally important effect. Evidence is insufficient to recommend using these agents in routine practice. Further methodologically robust randomized controlled trials with more refined selection criteria might reveal a beneficial effect.

  1. Endurance, aerobic high-intensity, and repeated sprint cycling performance is unaffected by normobaric "Live High-Train Low": a double-blind placebo-controlled cross-over study.

    Science.gov (United States)

    Bejder, Jacob; Andersen, Andreas Breenfeldt; Buchardt, Rie; Larsson, Tanja Hultengren; Olsen, Niels Vidiendal; Nordsborg, Nikolai Baastrup

    2017-05-01

    The aim was to investigate whether 6 weeks of normobaric "Live High-Train Low" (LHTL) using altitude tents affect highly trained athletes incremental peak power, 26-km time-trial cycling performance, 3-min all-out performance, and 30-s repeated sprint ability. In a double-blinded, placebo-controlled cross-over design, seven highly trained triathletes were exposed to 6 weeks of normobaric hypoxia (LHTL) and normoxia (placebo) for 8 h/day. LHTL exposure consisted of 2 weeks at 2500 m, 2 weeks at 3000 m, and 2 weeks at 3500 m. Power output during an incremental test, ~26-km time trial, 3-min all-out exercise, and 8 × 30 s of all-out sprint was evaluated before and after the intervention. Following at least 8 weeks of wash-out, the subjects crossed over and repeated the procedure. Incremental peak power output was similar after both interventions [LHTL: 375 ± 74 vs. 369 ± 70 W (pre-vs-post), placebo: 385 ± 60 vs. 364 ± 79 W (pre-vs-post)]. Likewise, mean power output was similar between treatments as well as before and after each intervention for time trial [LHTL: 257 ± 49 vs. 254 ± 54 W (pre-vs-post), placebo: 267 ± 57 vs. 267 ± 52 W (pre-vs-post)], and 3-min all-out [LHTL: 366 ± 68 vs. 369 ± 72 W (pre-vs-post), placebo: 365 ± 66 vs. 355 ± 71 W (pre-vs-post)]. Furthermore, peak- and mean power output during repeated sprint exercise was similar between groups at all time points (n = 5). In conclusion, 6 weeks of normobaric LHTL using altitude tents simulating altitudes of 2500-3500 m conducted in a double-blinded, placebo-controlled cross-over design do not affect power output during an incremental test, a ~26-km time-trial test, or 3-min all-out exercise in highly trained triathletes. Furthermore, 30 s of repeated sprint ability was unaltered.

  2. Risk of reproductive complications following chlamydia testing

    DEFF Research Database (Denmark)

    Davies, Bethan; Turner, Katy M E; Frølund, Maria;

    2016-01-01

    of pelvic inflammatory disease. Therefore, control programmes must prevent first and repeat infections to improve women's reproductive health. FUNDING: Unrestricted partial funding from Frederiksberg Kommune, Frederiksberg, Denmark. BD held an Medical Research Council Population Health Scientist Fellowship...

  3. 4-Repeat Tauopathy Neuroimaging Initiative - Cycle 2

    Science.gov (United States)

    2016-11-15

    Corticobasal Degeneration (CBD); Corticobasal Syndrome (CBS); Cortical-basal Ganglionic Degeneration (CBGD); Progressive Supranuclear Palsy (PSP); Nonfluent Variant Primary Progressive Aphasia (nfvPPA); Oligosymptomatic/Variant Progressive Supranuclear Palsy (o/vPSP)

  4. Reproductive health.

    Science.gov (United States)

    1999-04-01

    This article explores the reproductive health status of China. Since 1990, China has stepped up its efforts in promoting reproductive health and maternal and child health. Several studies demonstrated a remarkable progress made in this area. By 1997, maternal and infant mortality rates have declined, while the penetration rate for the immunization program and inpatient delivery rate increased. Despite these achievements, however, much remains to be done such as the lack of client-centered approaches to meet the increasingly diverse needs of the population for family planning services. A survey conducted in 1995 showed that the country's family planning program was focused primarily on demographic issues while little attention was given to reproductive health objectives. The situation improved when the State Planning Commission implemented its pilot program called the Quality of Care in Family Planning in China. The program yielded encouraging results including a reoriented philosophy towards reproductive health services, enhanced service facilities, informed choices for family planning methods, and the development of an operational information system. Another strategy adopted to address fertility and reproductive health issues was the implementation of adolescent reproductive health education as a required course for senior middle schools. Lastly, this article provided a brief overview of China's HIV/AIDS situation.

  5. Glycoprotein 5 of porcine reproductive and respiratory syndrome virus strain SD16 inhibits viral replication and causes G2/M cell cycle arrest, but does not induce cellular apoptosis in Marc-145 cells

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Yang, E-mail: muyang@nwsuaf.edu.cn [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Li, Liangliang, E-mail: lifeiyang2007@126.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Zhang, Beibei, E-mail: diana851218@163.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Huang, Baicheng, E-mail: hbch228@163.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Gao, Jiming, E-mail: jimingao2006@163.com [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A& F University, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture of the People' s Republic of China, No. 22 Xinong Road, Yangling, Shaanxi 712100 (China); and others

    2015-10-15

    Cell apoptosis is common after infection with porcine reproductive and respiratory syndrome virus (PRRSV). PRRSV GP5 has been reported to induce cell apoptosis. To further understand the role of GP5 in PRRSV induced cell apoptosis, we established Marc-145 cell lines stably expressing full-length GP5, GP5{sup Δ84-96} (aa 84-96 deletion), and GP5{sup Δ97-119} (aa 97-119 deletion). Cell proliferation, cell cycle progression, cell apoptosis and virus replication in these cell lines were evaluated. Neither truncated nor full-length GP5 induced cell apoptosis in Marc-145 cells. However, GP5{sup Δ97-119}, but not full-length or GP5{sup Δ84-96}, induced a cell cycle arrest at the G2/M phase resulting in a reduction in the growth of Marc-145 cells. Additionally, GP5{sup Δ84-96} inhibited the replication of PRRSV in Marc-145 cells through induction of IFN-β. These findings suggest that PRRSV GP5 is not responsible for inducing cell apoptosis in Marc-145 cells under these experimental conditions; however it has other important roles in virus/host cell biology. - Highlights: • Marc-145 cell lines stable expression PRRSV GP5 or truncated GP5 were constructed. • GP5{sup Δ97-119} expression in Marc-145 cell induced cell cycle arrest at G2/M phase. • Expression of GP5 and truncated GP5 could not induce Marc-145 cells apoptosis. • PRRSV replication in Marc-145-GP5{sup Δ84-96} was significantly inhibited.

  6. Intrauterine insemination of cultured peripheral blood mononuclear cells prior to embryo transfer improves clinical outcome for patients with repeated implantation failures.

    Science.gov (United States)

    Madkour, Aicha; Bouamoud, Nouzha; Louanjli, Noureddine; Kaarouch, Ismail; Copin, Henri; Benkhalifa, Moncef; Sefrioui, Omar

    2016-02-01

    Implantation failure is a major limiting factor in assisted reproduction improvement. Dysfunction of embryo-maternal immuno-tolerance pathways may be responsible for repeated implantation failures. This fact is supported by immunotropic theory stipulating that maternal immune cells, essentially uterine CD56+ natural killer cells, are determinants of implantation success. In order to test this hypothesis, we applied endometrium immuno-modulation prior to fresh embryo transfer for patients with repeated implantation failures. Peripheral blood mononuclear cells were isolated from repeated implantation failure patients undergoing assisted reproductive technology cycles. On the day of ovulation induction, cells were isolated and then cultured for 3 days and transferred into the endometrium cavity prior to fresh embryo transfer. This immunotherapy was performed on 27 patients with repeated implantation failures and compared with another 27 patients who served as controls. Implantation and clinical pregnancy were increased significantly in the peripheral blood mononuclear cell test versus control (21.54, 44.44 vs. 8.62, 14.81%). This finding suggests a clear role for endometrium immuno-modulation and the inflammation process in implantation success. Our study showed the feasibility of intrauterine administration of autologous peripheral blood mononuclear cells as an effective therapy to improve clinical outcomes for patients with repeated implantation failures and who are undergoing in vitro fertilization cycles.

  7. Sex steroid levels in XY males and sex-reversed XX males, of rainbow trout (Oncorhynchus mykiss), during the reproductive cycle.

    Science.gov (United States)

    Espinosa, E; Josa, A; Gil, L; González, N

    2011-02-01

    In this study, the annual cycle of the gonadal steroids testosterone (T), 11-ketotestosterone (11-KT), 17β-oestradiol (E2) and 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) was determined using radioimmunoassay and then compared, for XY males (n=35) and sex-reversed XX males (n=27) rainbow trout, to establish possible endocrinology differences. Both in XY males and sex-reversed XX males, significant correlation was shown between body weight and T (r=0.5046 and 0.34078, respectively; psex-reversed XX males were similar and showed an intense seasonal variation. The highest levels for T and 11-KT were detected from December to April with a peak in January (51.67 ± 5.11 and 61.95 ± 4.25 ng/ml, for XY males and 57.1 ± 5.82 and 59.27 ± 4.84 ng/ml, respectively, for XX males). In addition, there was a positive correlation (psex-reversed XX males (r=0.6019). Concentrations of DHP in XY males also showed seasonal variation with a peak in February (25.18 ± 12.99 ng/ml). However, DHP levels in sex-reversed XX males were undetectable (sex-reversed XX males were similar to those observed in XY males. The only difference in the annual gonadal steroid cycle between XY and sex-reversed XX males was in the DHP profile. © 2009 Blackwell Verlag GmbH.

  8. Intravenous immunoglobulin G in women with reproductive failure: The Korean Society for Reproductive Immunology practice guidelines.

    Science.gov (United States)

    Sung, Nayoung; Han, Ae Ra; Park, Chan Woo; Park, Dong Wook; Park, Joon Cheol; Kim, Na Young; Lim, Kyung Sil; Shin, Ji Eun; Joo, Chang Woo; Lee, Seung Eun; Kim, Jae Won; Lee, Sung Ki

    2017-03-01

    The task force of the Korean Society for Reproductive Immunology recommends intravenous immunoglobulin G treatment in women with reproductive failure, including recurrent pregnancy loss and/or repeated implantation failure, who show cellular immune factors such as abnormal natural killer cell levels, natural killer cell cytotoxicity, and/or type 1 T helper immunity.

  9. Reproductive cycle of Mellita quinquiesperforata (Leske (Echinodermata, Echinoidea in two contrasting beach environments Reprodução de Mellita quinquiesperforata (Leske (Echinodermata, Echinoidea em dois ecossistemas praiais contrastantes

    Directory of Open Access Journals (Sweden)

    Yara A. G. Tavares

    2006-06-01

    Full Text Available The reproductive cycle of the irregular echinoid Mellita quinquiesperforata (Leske, 1778 was studied in populations from two sand beaches with different morphodynamic conditions in Parana coast, from February 1992 through July 1994. Gametogenesis was described by histological and gonad index methods and the differences between both populations were observed in the extension of nutrient storage and spawning period. Both populations exhibited a main reproductive period during spring/summer and a nutrient storage period during autumn/winter months. The spawning period at the intermediate-dissipative beach was shorter than at the reflective beach. Meanwhile, a nutrient storage stage was more extensive in the latter. Gonad index varied between both sexes and it was influenced by population characteristics. Different strategies in allocation of resources between maintenance and reproduction effort (oocyte size confirm the high adaptive plasticity developed by this species to live in contrasting beach environments.O ciclo reprodutivo do equinóide irregular Mellita quinquiesperforata (Leske, 1778 foi estudado em populações de duas praias com diferentes condições morfodinâmicas na costa paranaense, de fevereiro de 1992 a julho de 1994. A gametogênese foi descrita pela análise histológica das gônadas e pela variação do índice gonadal. Foram encontradas diferenças com relação à extensão do período de estocagem de nutrientes e do período de liberação dos gametas nas populações. Ambas exibiram um marcado período reprodutivo na primavera e no verão e uma época de estocagem de nutrientes no outono e no inverno. Na praia intermediária-dissipativa a liberação de gametas ocorreu num período menor do que na reflectiva, porém a fase de acúmulo de reservas nutritivas foi mais extensa na primeira. O índice gonadal apresentou variações entre os sexos e foi influenciado pelas características populacionais. As diferentes estrat

  10. Telomeres and human reproduction.

    Science.gov (United States)

    Kalmbach, Keri Horan; Fontes Antunes, Danielle Mota; Dracxler, Roberta Caetano; Knier, Taylor Warner; Seth-Smith, Michelle Louise; Wang, Fang; Liu, Lin; Keefe, David Lawrence

    2013-01-01

    Telomeres mediate biologic aging in organisms as diverse as plants, yeast, and mammals. We propose a telomere theory of reproductive aging that posits telomere shortening in the female germ line as the primary driver of reproductive aging in women. Experimental shortening of telomeres in mice, which normally do not exhibit appreciable oocyte aging, and which have exceptionally long telomeres, recapitulates the aging phenotype of human oocytes. Telomere shortening in mice reduces synapsis and chiasmata, increases embryo fragmentation, cell cycle arrest, apoptosis, spindle dysmorphologies, and chromosome abnormalities. Telomeres are shorter in the oocytes from women undergoing in vitro fertilization, who then produce fragmented, aneuploid embryos that fail to implant. In contrast, the testes are replete with spermatogonia that can rejuvenate telomere reserves throughout the life of the man by expressing telomerase. Differences in telomere dynamics across the life span of men and women may have evolved because of the difference in the inherent risks of aging on reproduction between men and women. Additionally, growing evidence links altered telomere biology to endometriosis and gynecologic cancers, thus future studies should examine the role of telomeres in pathologies of the reproductive tract.

  11. Morphological indicators of initial reproductive commitment in Mustelus schmitti (Springer 1939 (Chondrichthyes, Triakidae: folliculogenesis and ovarian structure over the life cycle

    Directory of Open Access Journals (Sweden)

    EJ Galíndez

    Full Text Available This work provides information about the sexual commitment and the folliculogenesis of the gatuzo, Mustelus schmitti. A total of 112 females of all maturity stages were fished in the Bahía Blanca estuary, between 2009 and 2010. The oogonia were present throughout the life cycle of the animals. The folliculogenesis follows a pattern similar to other elasmobranchs. The granulosa layer keeps monolayered throughout the folliculogenesis, but with two cell types in the vitellogenic follicle. The zona pellucida forms in the primordial follicles. The thecal system shows a connective inner layer and a glandular outer sheath. The microscopic beginning of the sexual commitment, indicated by the vitello hoarding, takes place in follicles from 500 micrometres, while the macroscopic evidence appears in follicles of 2500-3000 micrometres. The results presented in this study suggest that the fishery pressure may affect a susceptible range of sizes of the species, not previously considered and provides a biological framework for the development of fisheries policy.

  12. Resultados das técnicas de reprodução assistida em mulheres doadoras de oócitos no ciclo de tratamento Outcome of assisted reproductive technologies in women with oocyte donation in the treatment cycle

    Directory of Open Access Journals (Sweden)

    Edvaldo Cavalcante

    2005-11-01

    Full Text Available OBJETIVO: comparar os resultados de ciclos de reprodução assistida em mulheres doadoras de oócitos no ciclo de tratamento com o de mulheres não doadoras. MÉTODOS: foram avaliadas, retrospectivamente, as taxas de gravidez, implantação e abortamento de 50 pacientes que doaram oócitos durante o ciclo de reprodução assistida (grupo de doadoras e de 50 pacientes que não doaram oócitos (grupo de não-doadoras, em clínica privada de reprodução assistida em São Paulo, entre os anos de 2001 e 2003. Os critérios de inclusão no estudo foram os seguintes: idade menor que 35 anos; ciclos menstruais regulares; dosagem basal de FSH0,05. CONCLUSÃO: em pacientes que recuperam mais de seis oócitos, a doação de oócitos no ciclo de tratamento não prejudica os resultados dos ciclos de reprodução assistida e não eleva as taxas de abortamento.PURPOSE: to compare the outcome of treatment in patients undergoing assisted reproductive technology (ART cycles who donated eggs during their own ART treatment with the outcome of patients undergoing ART without egg donation. METHODS: we studied retrospectively the pregnancy and implantation rates of 50 patients who donated eggs during the course of their ART treatment (donor group, and the pregnancy and implantation rates of 50 patients who underwent ART cycles and kept all their eggs (non-donor group. between the years 2001-2003. The inclusion criteria used were as follows: age 0.05. CONCLUSION: this study suggests that in patients who produce more than 6 oocytes, egg donation in the treatment cycle does not influence adversely the outcome of ART cycles and does not increase the miscarriage rate.

  13. Repeat-until-success quantum repeaters

    Science.gov (United States)

    Bruschi, David Edward; Barlow, Thomas M.; Razavi, Mohsen; Beige, Almut

    2014-09-01

    We propose a repeat-until-success protocol to improve the performance of probabilistic quantum repeaters. Conventionally, these rely on passive static linear-optics elements and photodetectors to perform Bell-state measurements (BSMs) with a maximum success rate of 50%. This is a strong impediment for entanglement swapping between distant quantum memories. Every time a BSM fails, entanglement needs to be redistributed between the corresponding memories in the repeater link. The key ingredients of our scheme are repeatable BSMs. Under ideal conditions, these turn probabilistic quantum repeaters into deterministic ones. Under realistic conditions, our protocol too might fail. However, using additional threshold detectors now allows us to improve the entanglement generation rate by almost orders of magnitude, at a nominal distance of 1000 km, compared to schemes that rely on conventional BSMs. This improvement is sufficient to make the performance of our scheme comparable to the expected performance of some deterministic quantum repeaters.

  14. The Role of Heparin in Embryo Implantation in Women with Recurrent Implantation Failure in the Cycles of Assisted Reproductive Techniques (Without History of Thrombophilia.

    Directory of Open Access Journals (Sweden)

    Kobra Hamdi

    2015-06-01

    Full Text Available Several studies have shown the improving effect of heparin on the outcomes of ART. Moreover, it has been reported that adding heparin in non-thrombophilia patients with RIF is useful.The aim of this study was to evaluate the beneficial effects of heparin on ART outcomes in women with history of recurrent implantation failure (RIF and without history of congenital or acquired thrombophilia in a randomized, controlled clinical trial (RCT.In this study, 100 patients with a history of two or more failures in implantation in cycles of ART were randomly subdivided into two groups of study and control. Patients of the control group just received the luteal phase support. In the patients of study group, in addition to the routine support of luteal phase following in vitro fertilization (IVF or intra cytoplasmic sperm injection (ICSI, 5000 units of subcutaneous heparin was administered for 15 days from the day of oocyte pick up. Pregnancy test (β-HCG was done for patient of two groups 15 days after IVF.In the study group, pregnancy test was positive in 16 (32% patients and negative in 34 (68% patients. In the control group, pregnancy test was positive in 15 (30% patients and negative in 35 (70% patients. There was no significant difference between two groups for the role of heparin in the pregnancy rate (p = 0.5.Although the effect of heparin on pregnancy was not statistically significant in this study, with regard to the numerous benefits of this agent, it is recommended to study its effects in further studies with lager sample size.

  15. Impact of Mid-Luteal Phase GnRH Agonist Administration on Reproductive Outcomes in GnRH Agonist-Triggered Cycles: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Abdelhamid Benmachiche

    2017-06-01

    Full Text Available ObjectiveTo explore whether the addition of a mid-luteal bolus of GnRH agonist (GnRHa improves the implantation rate (IR in in vitro fertilization (IVF cycles.DesignA randomized controlled trial.SettingPrivate IVF center.Patients328 IVF/intracytoplasmic sperm injection patients were triggered with GnRHa and received 1,500 IU HCG on the day of oocyte pick-up (OPU in addition to a standard luteal phase support (LPS.Intervention(sIn addition, the study group received a bolus of GnRHa 6 days after OPU, whereas the control group did not.Main outcome measureImplantation rate.Secondary outcome measure(sOngoing pregnancy (OP and live birth (LB rates.ResultsAlthough serum concentrations of FSH, LH, E2, and P on day OPU + 7 were significantly higher in the study group compared to the control group, the IR was not statistically different between the treatment group (27% and the control group (23% [odds ratio (OR 1.2 (95% CI 0.9–1.7, P < 0.27]. Similarly, the OP rate was 37% in the treatment group and 31% in the control group [OR 1.3 (95% CI 0.8–2.0, P < 0.23]. The LB rate was 36% in the treatment group and 31% in the control group [OR: 1.3 (95% CI 0.8–2.0, P < 0.27].ConclusionAlthough a trend toward a higher IR and pregnancy rate was observed in the treatment group, this difference was not statistically significant. However, the absolute risk difference of 5% found for LB is clinically relevant, warranting further investigation.NCT02053779.

  16. Manipulating insulin signaling to enhance mosquito reproduction

    Directory of Open Access Journals (Sweden)

    Rasgon Jason L

    2009-08-01

    Full Text Available Abstract Backgrond In the mosquito Aedes aegypti the insulin/insulin growth factor I signaling (IIS cascade is a key regulator of many physiological processes, including reproduction. Two important reproductive events, steroidogenesis in the ovary and yolk synthesis in the fat body, are regulated by the IIS cascade in mosquitoes. The signaling molecule phosphatase and tensin homolog (PTEN is a key inhibitor of the IIS cascade that helps modulate the activity of the IIS cascade. In Ae. aegypti, six unique splice variants of AaegPTEN were previously identified, but the role of these splice variants, particularly AaegPTEN3 and 6, were unknown. Results Knockdown of AaegPTEN or its specific splice variant AaegPTEN6 (the splice variant thought to regulate reproduction in the ovary and fat body using RNAi led to a 15–63% increase in egg production with no adverse effects on egg viability during the first reproductive cycle. Knockdown of AaegPTEN3, expressed predominantly in the head, had no effect on reproduction. We also characterized the protein expression patterns of these two splice variants during development and in various tissues during a reproductive cycle. Conclusion Previous studies in a range of organisms, including Drosophila melanogaster and Caenorhabditis elegans, have demonstrated that disruption of the IIS cascade leads to decreased reproduction or sterility. In this study we demonstrate that knockdown of the IIS inhibitor PTEN can actually increase reproduction in the mosquito, at least during the first reproductive cycle.

  17. Relationship between prolactin, reproductive experience, and parental care in a biparental songbird, the zebra finch (Taeniopygia guttata).

    Science.gov (United States)

    Smiley, Kristina O; Adkins-Regan, Elizabeth

    2016-06-01

    Hormonal systems have long been thought to play an important role in stimulating the onset of parental behavior, a critical component of reproductive success in a variety of taxa. Elevations in the peptide hormone prolactin (PRL) have been repeatedly positively correlated with the onset and maintenance of parental care across vertebrate species. A causal role for PRL in parental care has been established in several mammalian species, but less evidence for a causal role of PRL and parental care exists in birds. The zebra finch, a socially monogamous, biparental songbird, is an exceptionally useful animal model to study parental care and other close social relationships. Both sexes share parental care equally, exhibit the same parental behaviors, and show a marked improvement in breeding success with experience. We hypothesize that PRL is critically involved in the expression of zebra finch parental care and predict that circulating PRL levels will increase with breeding experience. To begin testing this, we measured plasma PRL concentrations in 14 male-female zebra finch pairs (N=28) across two breeding cycles, using a repeated measures design. PRL was measured in the birds' first, reproductively inexperienced, breeding cycle beginning at courtship and extending through chick fledging. PRL was measured again during the birds' second, reproductively experienced, breeding cycle, beginning with egg laying until chick fledging. We found that plasma PRL is significantly elevated from non-breeding concentrations during late incubation and early post-hatch care and that this elevation is greater in the reproductively experienced cycle compared to the inexperienced cycle. Findings of this study will be used to inform hypotheses and predictions for future experimental manipulations of PRL during parental care.

  18. Reproductive physiology

    Science.gov (United States)

    Gee, G.F.; Russman, S.E.; Ellis, David H.; Gee, George F.; Mirande, Claire M.

    1996-01-01

    Conclusions: Although the general pattern of avian physiology applies to cranes, we have identified many physiological mechanisms (e.g., effects of disturbance) that need further study. Studies with cranes are expensive compared to those done with domestic fowl because of the crane's larger size, low reproductive rate, and delayed sexual maturity. To summarize, the crane reproductive system is composed of physiological and anatomical elements whose function is controlled by an integrated neural-endocrine system. Males generally produce semen at a younger age than when females lay eggs. Eggs are laid in clutches of two (1 to 3), and females will lay additional clutches if the preceding clutches are removed. Both sexes build nests and incubate the eggs. Molt begins during incubation and body molt may be completed annually in breeding pairs. However, remiges are replaced sequentially over 2 to 3 years, or abruptly every 2 to 3 years in other species. Most immature birds replace their juvenal remiges over a 2 to 3 year period. Stress interferes with reproduction in cranes by reducing egg production or terminating the reproductive effort. In other birds, stress elevates corticosterone levels and decreases LHRH release. We know little about the physiological response of cranes to stress.

  19. Reproductive epidemiology

    DEFF Research Database (Denmark)

    Olsen, Jørn; Nøhr, Ellen Aagaard

    2010-01-01

    Reproductive health covers a broad category of health and disease conditions, according to the Cairo Statement. This chapter focuses on subfecundity fertility, fetal death, malformations, pregnancy complications, sexual health, and diseases that may have their origin in fetal life, but which will...

  20. Reproductive hacking

    Science.gov (United States)

    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

  1. Reproductive Physiology in Cetaceans (Review)

    OpenAIRE

    1996-01-01

    This paper briefly reviews some works on reproductive physiology in cetaceans with special reference to dolphins from the following aspects: estrous cycle in female dolphins, hormonal profiles during pregnancy, testosterone levels and seasonality in testicular activity, ovulation induction and sperm collection and freezing.

  2. Reprodução de Lytechinus variegatus (Echinodermata: Echinoidea: efeito do ciclo lunar e características da população = Reproduction of Lytechinus variegatus (Echinodermata: Echinoidea: effect of lunar cycle and population characteristics

    Directory of Open Access Journals (Sweden)

    Alexandra Mara Cruz Lage

    2011-07-01

    Full Text Available Este estudo avaliou as características reprodutivas de uma população do ouriço do mar Lytechinus variegatus e a influência do ciclo lunar na liberação de gametas. Foram realizadas oito coletas para avaliação do índice gonadossomático (IG e dos parâmetros populacionais relacionados com a reprodução. Para avaliação do efeito da Lua na liberação de gametas foram realizadas coletas em três ciclos lunares completos. Ao todo foram coletados 295 indivíduos, sendo 156 machos e 131 fêmeas (proporção 1,19:1, porém não houve diferença significativa na proporção sexual da população. O peso dos machos foisignificativamente maior que o das fêmeas, porém não houve diferença significativa no IG, peso gonadal e diâmetro entre os sexos. Com a amplitude no diâmetro dos animais coletados (5,5-8,7 cm foram estabelecidas cinco classes de tamanho. Não houve diferençassignificativas no IG entre as classes de tamanho. Houve efeito da periodicidade lunar na liberação de gametas, com menor IG na lua nova, indicando que esta ocorre no primeiro quarto lunar e em marés de sizígia.This work evaluated the spawning of sea urchin Lytechinus variegates based on lunar cycle and population characteristics. Eight monthly collections were realized to estimate the gonadosomatic index (GI and population parameters regarding reproduction. To evaluate the effect of the lunar cycle on spawning, samples were taken for each moon phase of three lunar cycles. In the entire work 295 individuals were collected, 156 males and 131 females (1.19:1 ratio. However, there was no significant difference in the sex ratio of the population. The weight of males was significantly greater than that of females. There were no differences between males and females in gonadosomatic index (GI, gonad weight and diameter. There was aneffect of the lunar periodicity on spawning, with lower GI in new moon, indicating that spawning occurs on the first lunar quarter in spring

  3. Hysteresis of magnetostructural transitions: Repeatable and non-repeatable processes

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, Virgil [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Della Torre, Edward; Bennett, Lawrence H. [Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052 (United States); ElBidweihy, Hatem, E-mail: Hatem@gwmail.gwu.edu [Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052 (United States)

    2014-02-15

    The Gd{sub 5}Ge{sub 2}Si{sub 2} alloy and the off-stoichiometric Ni{sub 50}Mn{sub 35}In{sub 15} Heusler alloy belong to a special class of metallic materials that exhibit first-order magnetostructural transitions near room temperature. The magnetic properties of this class of materials have been extensively studied due to their interesting magnetic behavior and their potential for a number of technological applications such as refrigerants for near-room-temperature magnetic refrigeration. The thermally driven first-order transitions in these materials can be field-induced in the reverse order by applying a strong enough field. The field-induced transitions are typically accompanied by the presence of large magnetic hysteresis, the characteristics of which are a complicated function of temperature, field, and magneto-thermal history. In this study we show that the virgin curve, the major loop, and sequentially measured MH loops are the results of both repeatable and non-repeatable processes, in which the starting magnetostructural state, prior to the cycling of field, plays a major role. Using the Gd{sub 5}Ge{sub 2}Si{sub 2} and Ni{sub 50}Mn{sub 35}In{sub 15} alloys, as model materials, we show that a starting single phase state results in fully repeatable processes and large magnetic hysteresis, whereas a mixed phase starting state results in non-repeatable processes and smaller hysteresis.

  4. Repeated Surveys and Historical Nautical Charts Support Elastic Rebound Model on Megathrust at Santa MARÍA Island, Chile, (37°S) Through One and One-Half Seismic Cycles

    Science.gov (United States)

    Wesson, R. L.; Melnick, D.; Cisternas, M.; Ely, L. L.; Moreno, M.

    2010-12-01

    Repeated bathymetric surveys, historical nautical charts, geologic observations, interviews with local residents, and modern GPS measurements all support a pattern of coseismic uplift, followed by post-seismic and inter-seismic subsidence, at Santa María Island off the coast of south-central Chile. The island is located approximately 75 km landward of the Chile trench and about 12 km above the megathrust fault. Six weeks after the February 20, 1835 Concepcion earthquake (~M 8.5), Captain Robert FitzRoy and the HMS Beagle visited the island and reported 2.4-3 m of uplift based primarily on observations of elevated, newly dead, intratidal and subtidal shellfish attached to rocks. The February 27, 2010 Maule earthquake (M 8.8) earthquake produced similar effects. Several lines of evidence suggest significant subsidence between 1835 and 2010. First, the extensive wave-cut platform at the northern end of island that FitzRoy vividly describes as being exposed and covered with dead shellfish in 1835, lay at the lower level of the island’s 2-m tidal range in January 2010. The nautical chart prepared by officers of the Beagle suggests that the platform was above high tide in 1835. An elderly resident reports that in the first half of the twentieth century part of the platform was above high tide. While some lowering of the bedrock platform could be explained by erosion, the amount of required erosion would be very rapid and extensive. GPS measurements for the interval 2004-2008 indicate that the island subsided at a rate of 10 +/- 1 mm/a as well as moving landward at a rate of 42 mm/a. On January 13 and 15, 2010, we carried out a simple echo-sounder survey in the bay off the southeastern coast of Santa María Island. The same bay, Rada Santa Maria, was surveyed by the Beagle in 1835 using a lead line and pole. The bay has a smooth and very gently sloping bottom, an average depth of about 8 m, and dimensions of about 3 x 5 km. Comparison of our measured depths with those

  5. Grandparental effects on reproductive strategizing

    Directory of Open Access Journals (Sweden)

    2004-09-01

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

  6. REPRODUCTIVE ADAPTATIONS OF THE GREEN IGUANA ON A SEMIARID ISLAND

    NARCIS (Netherlands)

    LICHTENBELT, WDV; ALBERS, KB

    1993-01-01

    Reproductive cycle and clutch size were studied in the green iguana (Iguana iguana) on the semiarid Caribbean island of Curacao. The reproductive cycle is correlated with seasonality in rainfall. Mating is in the first half of the dry season, egg laying in the second part of the dry season, and hatc

  7. Effets de Panicum maximum Jacq. associé à Euphorbia heterophylla (L. Klotz. & Garcke sur la productivité des femelles durant le cycle de reproduction chez le cobaye (Cavia porcellus L.

    Directory of Open Access Journals (Sweden)

    N'G. D.V. Kouakou

    2015-01-01

    Full Text Available Effect of Panicum maximum Jacq. Associated with Euphorbia heterophylla (L. Klotz. & Garcke on Productivity of Females (Cavia porcellus L During the Reproductive Cycle. In Ivory Coast, Guinea pigs reared for meat (Cavia porcellus L. are mainly fed with Panicum maximum Jacq. The association of this forage with Euphorbia heterophylla (L. Klotz. & Garcke improves the organic matter digestibility of the mixed diet compared to P. maximum distributed alone in growing male guinea pigs. In order to determine the effect of this diet during gestation and lactation in female guinea pigs, three diets: P. maximum (PAN basic diet; P. maximum associated to E. heterophylla (PANEUPH and P. maximum associated to pellets for rabbit (PANGRAN, were distributed ad libitum to multiparous guinea pigs (604.9 ± 40.8 g. The daily ingestion during gestation and lactation were 59.8±11.2 and 53.2±8.5; 61.5±5.2 and 72.9±16.4; 83.1±12.9 and 111.3±13.9 g DM.d-1 respectively for PAN, PANEUPH and PANGRAN. Similarly, the rates of fecundity were 111.1±0.9; 188.9±0.6 and 244.4±0.5% respectively for PAN, PANEUPH and PANGRAN. The individual birth weight and weight gain during lactation of the piglets were 58.7±12.4, 75.6±16.2 and 102.5±12 g and 2.4±0.6; 4.1±0.9 and 6.5±1.2 g.d-1 respectively for PAN, PANEUPH, and PANGRAN. In conclusion, the association of P. maximum and E. heterophylla significantly improves ingestion, digestibility, fecundity, birth weight and weaning weight in guinea pigs in comparison to Panicum maximum used as a sole diet.

  8. Viewpoints on apornictic and sexual reproduction in angiosperms

    Directory of Open Access Journals (Sweden)

    Sven Asker

    2014-01-01

    Full Text Available Gametophytic apomixis implies different changes of the reproductive cycle of sexual plants. Each of these "elements of apomixis" occurs in sexual plants, which may even display functional diploid parthenogenesis. Thus, apomixis, like vegetative reproduction, is part of the reproductive behaviour of sexual plants, becoming important when sexual reproduction is impaired. The elements of apomixis are probably to a large extent under polygenic control.

  9. Selective Reproduction

    DEFF Research Database (Denmark)

    Svendsen, Mette N.

    2015-01-01

    This article employs a multi-species perspective in investigating how life's worth is negotiated in the field of neonatology in Denmark. It does so by comparing decision-making processes about human infants in the Danish neonatal intensive care unit with those associated with piglets who serve as...... as expectations within linear or predictive time frames are key markers in both sites. Exploring selective reproductive processes across human infants and research piglets can help us uncover aspects of the cultural production of viability that we would not otherwise see or acknowledge....

  10. Reproductive system

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    950267 Secretion of sex hormone in response to sin-gle or repeated administration of human chorionic go-nadotropin in adult males.LI Jianyuan(李江源),etal.General Hosp PLA.Beijing,100853.Med J ChinPLA 1994:19(6):422-424.Fourteen healthy adult males accepted intramuscular2000 IU of human chorionic gonadotropin (HCG) in 3ways such as single injection,one injection daily for 2successive days and 12 rejections in

  11. Female Reproductive System

    Science.gov (United States)

    ... Reproductive System en español Sistema reproductor femenino About Human Reproduction All living things reproduce. Reproduction — the process by ... male and female reproductive systems are essential for reproduction. The female needs a ... like other organisms, pass certain characteristics of themselves ...

  12. Female reproductive disorders

    DEFF Research Database (Denmark)

    Crain, D Andrew; Janssen, Sarah J; Edwards, Thea M

    2008-01-01

    To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive...

  13. Normal Female Reproductive Anatomy

    Science.gov (United States)

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

  14. Reproduction, physiology and biochemistry

    Science.gov (United States)

    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...

  15. My Reproductive Life Plan

    Science.gov (United States)

    ... Button Information For... Media Policy Makers My Reproductive Life Plan Language: English Español (Spanish) Recommend on Facebook Tweet ... to achieve those goals is called a reproductive life plan . There are many kinds of reproductive life plans. ...

  16. Life cycle of the oriental compost worm Perionyx excavatus ...

    African Journals Online (AJOL)

    1989-03-21

    Mar 21, 1989 ... production, the life cycle of the vermicomposting species, Perionyx excavatus, was studied. The development, growth and reproduction of P. excavatus were investigated. ..... reproductive system of the earthworm: Perionyx.

  17. Female reproductive disorders

    DEFF Research Database (Denmark)

    Crain, D Andrew; Janssen, Sarah J; Edwards, Thea M;

    2008-01-01

    To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive disrupti......To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive...

  18. Quantum repeated games revisited

    CERN Document Server

    Frackiewicz, Piotr

    2011-01-01

    We present a scheme for playing quantum repeated 2x2 games based on the Marinatto and Weber's approach to quantum games. As a potential application, we study twice repeated Prisoner's Dilemma game. We show that results not available in classical game can be obtained when the game is played in the quantum way. Before we present our idea, we comment on the previous scheme of playing quantum repeated games.

  19. 进化的女性生理周期:波动的繁衍动机和行为表现%The Evolved Ovulation Cycle:Fluctuating Reproduction Motivation and Behavior

    Institute of Scientific and Technical Information of China (English)

    陈瑞; 郑毓煌

    2015-01-01

    The evolutional psychology theory suggests that women’s psychology and behavior fluctuate with their menstrual cycle, due to the fluctuating reproduction motives activated by the brief chance of conception. The conception chance accompanied by ovulation boosts women’s sexual desire, causingthem to seek and attract mates. In order to make sure the offspring inherits good genes, women prefer men with characteristics of good genes; meanwhile, women would be more likely to use self-protection behavior to protect their offspring from staining by bad genes. Further, the ovulation cues can affect men’s motivation and behavior as well. Future research should explore other motivations and behaviors caused by ovulation, such as the competitive motivation among females and consumer behavior, to enhance practical implications.%进化心理学认为女性会随生理周期的变化发生心理和行为的波动,这是由于短暂受孕机会造成的繁衍动机的波动。排卵带来的受孕机会使得女性产生更加强烈的性欲,追求、吸引配偶。为了确保子女基因的优良,女性在排卵期偏好具备优良基因特质的男性,同时采取自我保护行为以避免遗传基因被玷污。此外,女性排卵期的特征还会影响到男性的动机和行为。未来研究应进一步探索排卵期对女性同性间竞争等其他动机的影响,以及消费行为等方面的研究,以拓展实践启示。

  20. 墨西哥帕丘卡卵胎生条纹强棱蜥的繁殖周期%Reproductive cycle of the viviparous lizard Sceloporus grammicus(Squamata:Phrynosomatidae)from Pachuca,Hidalgo,México

    Institute of Scientific and Technical Information of China (English)

    Aurelio RAM(I)REZ-BAUTISTA; Carlos A.MACIEL-MATA; Miguel Angel MART(I)NEZ-MORALES

    2005-01-01

    In this study,we present the cycle and reproductive characteristics of the viviparous lizard Sceloporus grammicus from populations of arid environments near Pachuca City,in the state of Hidalgo,México.We obtained data from preserved specimens at two Mexican scientific collections.Males and females reached sexual maturity at the same snout-vent length(SVL,40.0 mm).Testicular mass of adult males began to increase in May and maximum testes mass occurred from July to August.Changes in testicular mass were not correlated with precipitation,temperature or photoperiod.Follicle mass in females began to increase in July and continued through October.Females contained embryos from November to July.Vitellogenesis and embryonic development were not correlated with photoperiod,temperature or precipitation.Mean litter size was 5.2±0.2 neonates(2-10).Litter size was correlated with female SVL.%本文报道墨西哥伊达尔戈州帕丘卡地区干旱环境中卵胎生条纹强棱蜥的繁殖周期及特征.测定墨西哥两个科学收藏馆的浸制标本获得数据.雌雄个体达到性成熟时的体长相等,为40.0 mm.雄体睾丸重量在5月开始增加,至7、8月达到最大.睾丸重量变化与降雨量、温度和光周期均无关.雌体卵泡重量在7月开始增加,并一直持续至10月.从11月至次年7月,雌体怀有胚胎.卵黄发生及胚胎发育与光周期、温度和降雨量无关.窝仔数与雌体体长呈正相关.平均窝仔数为5.2±0.2个(2-10个).

  1. Kisspeptins and the reproductive axis: potential applications to manage reproduction in farm animals.

    Science.gov (United States)

    Caraty, A; Decourt, C; Briant, C; Beltramo, M

    2012-08-01

    Kisspeptins (Kp) are a family of neuropeptides produced mainly by two hypothalamic neuronal cell populations. They have recently emerged as a major regulator of the gonadotropin axis and their action is located upstream of the gonadotropin-releasing hormone (GnRH) cell population. In less than 10 yr a growing body of literature has demonstrated the involvement of these peptides in most, if not all, aspects of reproductive axis maturation and function. In contrast to these abundant basic research studies, few experiments have evaluated the potential application of Kp as tools to manipulate reproduction in domestic animals. In mammals, exogenous Kp administration potently stimulates gonadotropin secretion. This action is exerted mainly, if not exclusively, through the stimulation of GnRH release. Intravenous, intraperitoneal, or subcutaneous administration of Kp induced a robust and rapid increase in plasma gonadotropins (luteinizing hormone [LH] and follicle-stimulating hormone [FSH]). However, this stimulatory effect is of short duration. Prolonged LH and FSH release over several hours can be achieved only when Kp are given as repeated multiple bolus or as an infusion. Kp administration was used in two experimental models, ewe and pony mare, with the aim of inducing well-timed and synchronized ovulations. During the breeding season, progesterone-synchronized ewes were given an intravenous infusion of Kp starting 30 h after the removal of progesterone implants. An LH surge was induced in all Kp-treated animals within 2 h of infusion onset. In contrast, in pony mares a constant infusion of Kp for 3 d in the the late follicular phase was unable to induce synchronized ovulation. Another set of studies showed that Kp could be used to activate reproductive function in acyclic animals. Pulsatile administration of Kp in prepubertal ewe lambs was shown to activate ovarian function, leading to enhanced ovarian steroidogenesis, stimulation of LH preovulatory surge, and

  2. Unisexual reproduction of Cryptococcus gattii.

    Directory of Open Access Journals (Sweden)

    Sujal S Phadke

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

  3. Human reproduction: current status

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Izzo

    2015-12-01

    Full Text Available SUMMARY The concern about the maintenance of the human species has existed since the earliest civilizations. Progress in the diagnosis and treatment of infertility has led to the development of assisted reproductive techniques (ART which, along with the evolution of genetics and molecular biology studies, have contributed in a concrete way to the management of infertile couples. Classic in vitro fertilization was initially developed 35 years ago for the treatment of women with tubal blockage, however, it remains inaccessible to a significant proportion of infertile couples around the world. This can be explained by the lack of specialized clinics in some countries and by the high cost of the procedures. Efforts have been employed to increase the number of treatment cycles for assisted reproduction, as for example, the creation of low-cost programs. Even today, infertility remains a problem of global proportions, affecting millions of couples. The estimate of the incidence of infertility is uncertain, mainly because of the criteria used for its definition. This article aims to review the most important aspects, succinctly, regarding the incidence, etiology, and treatment options available to infertile couples.

  4. Human reproduction: current status.

    Science.gov (United States)

    Izzo, Carlos Roberto; Monteleone, Pedro Augusto Araújo; Serafini, Paulo C

    2015-01-01

    The concern about the maintenance of the human species has existed since the earliest civilizations. Progress in the diagnosis and treatment of infertility has led to the development of assisted reproductive techniques (ART) which, along with the evolution of genetics and molecular biology studies, have contributed in a concrete way to the management of infertile couples. Classic in vitro fertilization was initially developed 35 years ago for the treatment of women with tubal blockage, however, it remains inaccessible to a significant proportion of infertile couples around the world. This can be explained by the lack of specialized clinics in some countries and by the high cost of the procedures. Efforts have been employed to increase the number of treatment cycles for assisted reproduction, as for example, the creation of low-cost programs. Even today, infertility remains a problem of global proportions, affecting millions of couples. The estimate of the incidence of infertility is uncertain, mainly because of the criteria used for its definition. This article aims to review the most important aspects, succinctly, regarding the incidence, etiology, and treatment options available to infertile couples.

  5. Asexual reproduction : genetics and evolutionary aspects

    OpenAIRE

    DE Meeûs, Thierry; Prugnolle, Franck; Agnew, Philip

    2007-01-01

    Reproduction is essential to all organisms if they are to contribute to the next generation. There are various means and ways of achieving this goal. This review focuses on the role of asexual reproduction for eukaryotic organisms and how its integration in a life cycle can influence their population genetics and evolution. An important question for evolutionary biologists as to why some organisms reproduce sexually, as opposed to asexually, is addressed. We also discuss the economic and medi...

  6. Asexual reproduction: genetics and evolutionary aspects.

    Science.gov (United States)

    de Meeûs, T; Prugnolle, F; Agnew, P

    2007-06-01

    Reproduction is essential to all organisms if they are to contribute to the next generation. There are various means and ways of achieving this goal. This review focuses on the role of asexual reproduction for eukaryotic organisms and how its integration in a life cycle can influence their population genetics and evolution. An important question for evolutionary biologists as to why some organisms reproduce sexually, as opposed to asexually, is addressed. We also discuss the economic and medical importance of asexual organisms.

  7. The role of prolactin in fish reproduction.

    Science.gov (United States)

    Whittington, Camilla M; Wilson, Anthony B

    2013-09-15

    Prolactin (PRL) has one of the broadest ranges of functions of any vertebrate hormone, and plays a critical role in regulating aspects of reproduction in widely divergent lineages. However, while PRL structure, mode of action and functions have been well-characterised in mammals, studies of other vertebrate lineages remain incomplete. As the most diverse group of vertebrates, fish offer a particularly valuable model system for the study of the evolution of reproductive endocrine function. Here, we review the current state of knowledge on the role of prolactin in fish reproduction, which extends to migration, reproductive development and cycling, brood care behaviour, pregnancy, and nutrient provisioning to young. We also highlight significant gaps in knowledge and advocate a specific bidirectional research methodology including both observational and manipulative experiments. Focusing research efforts towards the thorough characterisation of a restricted number of reproductively diverse fish models will help to provide the foundation necessary for a more explicitly evolutionary analysis of PRL function.

  8. Impacts of moonlight on fish reproduction.

    Science.gov (United States)

    Ikegami, Taro; Takeuchi, Yuki; Hur, Sung-Pyo; Takemura, Akihiro

    2014-04-01

    The waxing and waning cycle of the moon is repeated at approximately 1-month intervals, and concomitant changes occur in the levels of moonlight and cueing signals detected by organisms on the earth. In the goldlined spinefoot Siganus guttatus, a spawner lunar-synchronized around the first quarter moon, periodic changes in moonlight are used to cue gonadal development and gamete release. Rearing of mature fish under artificial constant full moon and new moon conditions during the spawning season leads to disruption or delay of synchronous spawning around the predicted moon phase. Melatonin, an endogenous transducer of the environmental light/dark cycle, increases in the blood and in the pineal gland around the new moon period and decreases around the full moon period. In synchrony with melatonin fluctuation, melatonin receptor(s) mRNA abundance is higher during the new moon period than during the full moon. The melatonin/melatonin receptor system is likely affected by moonlight. Measurements of the expression patterns of clock genes in neural tissues demonstrate that Cryptochrome (Cry1 and Cry3) and Period (Per2) fluctuate with lunar periodicity, the former peaking in the medial part of the brain around the first quarter moon period, and the latter peaking in the pineal gland around the full moon. Some clock genes may respond to periodic changes in moon phase and appear to be involved in the generation of lunar-related rhythmicity in lunar spawners. Thus, some fish use moonlight-related periodicities as reliable information for synchronizing the timing of reproductive events.

  9. Reproductive biology of freshwater fishes from the Venezuelan floodplains.

    Science.gov (United States)

    Guerrero, H Y; Cardillo, E; Poleo, G; Marcano, D

    2009-03-01

    This review describes the endocrine changes that occur during the annual reproductive cycle of Pygocentrus cariba, Pimelodus blochii, and Oxydoras sifontesi and their relationships with the environmental characteristics of Venezuelan floodplains. Most reproductive studies of teleosts have focused on changes that occur during annual cycles in temperate species but, in tropical fish, this has been examined less frequently. P. cariba, P. blochii, and O. sifontesi are seasonal breeders widely distributed along the Orinoco River. Under natural conditions they have an annual gonadal cycle closely related to changes in the annual hydrology cycle of the Orinoco River which defines two seasons on the floodplain: inundation and isolation. The reproductive cycle of these species seems to be controlled by cues from the external environment. Relevant data about gonadal maturation, for example gonadosomatic index and sexual hormones secretion, are contrasted. The role of catecholamines in neuroendocrine control of the reproductive axis is also considered in this work.

  10. Reconfigurable multiport EPON repeater

    Science.gov (United States)

    Oishi, Masayuki; Inohara, Ryo; Agata, Akira; Horiuchi, Yukio

    2009-11-01

    An extended reach EPON repeater is one of the solutions to effectively expand FTTH service areas. In this paper, we propose a reconfigurable multi-port EPON repeater for effective accommodation of multiple ODNs with a single OLT line card. The proposed repeater, which has multi-ports in both OLT and ODN sides, consists of TRs, BTRs with the CDR function and a reconfigurable electrical matrix switch, can accommodate multiple ODNs to a single OLT line card by controlling the connection of the matrix switch. Although conventional EPON repeaters require full OLT line cards to accommodate subscribers from the initial installation stage, the proposed repeater can dramatically reduce the number of required line cards especially when the number of subscribers is less than a half of the maximum registerable users per OLT. Numerical calculation results show that the extended reach EPON system with the proposed EPON repeater can save 17.5% of the initial installation cost compared with a conventional repeater, and can be less expensive than conventional systems up to the maximum subscribers especially when the percentage of ODNs in lightly-populated areas is higher.

  11. Revisiting the TALE repeat.

    Science.gov (United States)

    Deng, Dong; Yan, Chuangye; Wu, Jianping; Pan, Xiaojing; Yan, Nieng

    2014-04-01

    Transcription activator-like (TAL) effectors specifically bind to double stranded (ds) DNA through a central domain of tandem repeats. Each TAL effector (TALE) repeat comprises 33-35 amino acids and recognizes one specific DNA base through a highly variable residue at a fixed position in the repeat. Structural studies have revealed the molecular basis of DNA recognition by TALE repeats. Examination of the overall structure reveals that the basic building block of TALE protein, namely a helical hairpin, is one-helix shifted from the previously defined TALE motif. Here we wish to suggest a structure-based re-demarcation of the TALE repeat which starts with the residues that bind to the DNA backbone phosphate and concludes with the base-recognition hyper-variable residue. This new numbering system is consistent with the α-solenoid superfamily to which TALE belongs, and reflects the structural integrity of TAL effectors. In addition, it confers integral number of TALE repeats that matches the number of bound DNA bases. We then present fifteen crystal structures of engineered dHax3 variants in complex with target DNA molecules, which elucidate the structural basis for the recognition of bases adenine (A) and guanine (G) by reported or uncharacterized TALE codes. Finally, we analyzed the sequence-structure correlation of the amino acid residues within a TALE repeat. The structural analyses reported here may advance the mechanistic understanding of TALE proteins and facilitate the design of TALEN with improved affinity and specificity.

  12. Reproductive Disorders in Snakes.

    Science.gov (United States)

    Di Girolamo, Nicola; Selleri, Paolo

    2017-05-01

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

  13. 反复冻融对草鱼和鲤鱼冷冻鱼糜品质变化的影响%Effect of Repeated Freeze-Thaw Cycles on Quality Properties of Frozen Surimis of Grass Carp and Common Carp

    Institute of Scientific and Technical Information of China (English)

    吴晓; 孙卫青; 杨华; 马俪珍

    2012-01-01

    In order to explore the effect of repeated freeze-thaw cycles on their quality,color parameters,cooking loss,water-holding capacity,shearing force and TBARS of frozen surimis of grass carp and common carp were determined during 4 repeated freeze-thaw cycles.More freeze-thaw cycles could result in a significant increase(P0.05) in cooking loss of grass carp and common carp surimi and a significant reduction(P0.05) in water-holding capacity but no significant difference between both fish species was observed.The shearing force of grass carp surimi was inversely proportional to the number of freeze-thaw cycles.The first freeze-thaw cycle caused denaturation and contraction of protein in common carp surimi and resulted in an increase in its shearing force,whereas the parameter declined with increasing number of freeze-thaw cycles.Repeated freeze-thaw cycles aggravated lipid oxidation in surimi from both fish species.As a result,significantly increased TBARS(P0.05) was observed and a significant difference(P0.05) was also between both fish species.After the fourth freeze-thaw cycle,surimi from both carp species lost their original color.%为了解反复冻融对淡水冷冻鱼糜品质变化的影响,本实验以草鱼和鲤鱼冷冻鱼糜为研究对象,通过测定二者在反复冷冻-解冻后的色泽、蒸煮损失、持水性、剪切力和硫代巴比妥酸值等指标,分析冷冻鱼糜冷冻贮存4个月过程中,期间反复冻融4次后其品质的变化。结果表明:随着冻融次数的增加,两种鱼糜的蒸煮损失均显著增加(P〈0.05),持水性显著降低(P〈0.05),而两种鱼之间差异不显著。草鱼冷冻鱼糜的剪切力随着冻融次数的增加直线式下降;第1次冻融,鲤鱼鱼糜蛋白变性收缩,剪切力提高,之后随着冻融次数的增加剪切力下降。反复冻融促进了两种冷冻鱼糜的脂肪氧化,TBARS值显著增加(P〈0.05),且组间差异也显著(P〈0.05)。

  14. Recursive quantum repeater networks

    CERN Document Server

    Van Meter, Rodney; Horsman, Clare

    2011-01-01

    Internet-scale quantum repeater networks will be heterogeneous in physical technology, repeater functionality, and management. The classical control necessary to use the network will therefore face similar issues as Internet data transmission. Many scalability and management problems that arose during the development of the Internet might have been solved in a more uniform fashion, improving flexibility and reducing redundant engineering effort. Quantum repeater network development is currently at the stage where we risk similar duplication when separate systems are combined. We propose a unifying framework that can be used with all existing repeater designs. We introduce the notion of a Quantum Recursive Network Architecture, developed from the emerging classical concept of 'recursive networks', extending recursive mechanisms from a focus on data forwarding to a more general distributed computing request framework. Recursion abstracts independent transit networks as single relay nodes, unifies software layer...

  15. Shift work and circadian dysregulation of reproduction

    Directory of Open Access Journals (Sweden)

    Karen L. Gamble

    2013-08-01

    Full Text Available Health impairments, including reproductive issues, are associated with working nights or rotating shifts. For example, shift work has been associated with an increased risk of irregular menstrual cycles, endometriosis, infertility, miscarriage, low birth weight or pre-term delivery, and reduced incidence of breastfeeding. Based on what is known about circadian regulation of endocrine rhythms in rodents (and much less in humans, the circadian clock is an integral regulatory part of the reproductive system. When this 24-h program is disordered by environmental perturbation (such as shift work or genetic alterations, the endocrine system can be impaired. The purpose of this review is to explore the hypothesis that misalignment of reproductive hormones with the environmental light-dark cycle and/or sleep wake rhythms can disrupt menstrual cycles, pregnancy, and parturition. We highlight the role of the circadian clock in regulating human reproductive physiology and shift work-induced pathology within each step of the reproductive axis while exploring potential mechanisms from the animal model literature. In addition to documenting the reproductive hazards of shift work, we also point out important gaps in our knowledge as critical areas for future investigation. For example, future studies should examine whether forced desynchronization disrupts gonadotropin secretion rhythms and whether there are sleep/wake schedules that are better or worse for the adaptation of the reproductive system to shift work. These studies are necessary in order to define not only whether or not shift-work induced circadian misalignment impairs reproductive capacity, but also to identify strategies for the future that can minimize this desynchronization.

  16. Strengths and limitations of using repeat-dose toxicity studies to predict effects on fertility.

    Science.gov (United States)

    Dent, M P

    2007-08-01

    The upcoming European chemicals legislation REACH (Registration, Evaluation, and Authorisation of Chemicals) will require the risk assessment of many thousands of chemicals. It is therefore necessary to develop intelligent testing strategies to ensure that chemicals of concern are identified whilst minimising the testing of chemicals using animals. Xenobiotics may perturb the reproductive cycle, and for this reason several reproductive studies are recommended under REACH. One of the endpoints assessed in this battery of tests is mating performance and fertility. Animal tests that address this endpoint use a relatively large number of animals and are also costly in terms of resource, time, and money. If it can be shown that data from non-reproductive studies such as in-vitro or repeat-dose toxicity tests are capable of generating reliable alerts for effects on fertility then some animal testing may be avoided. Available rat sub-chronic and fertility data for 44 chemicals that have been classified by the European Union as toxic to fertility were therefore analysed for concordance of effects. Because it was considered appropriate to read across data for some chemicals these data sets were considered relevant for 73 of the 102 chemicals currently classified as toxic to reproduction (fertility) under this system. For all but 5 of these chemicals it was considered that a well-performed sub-chronic toxicity study would have detected pathology in the male, and in some cases, the female reproductive tract. Three showed evidence of direct interaction with oestrogen or androgen receptors (linuron, nonylphenol, and fenarimol). The remaining chemicals (quinomethionate and azafenidin) act by modes of action that do not require direct interaction with steroid receptors. However, both these materials caused in-utero deaths in pre-natal developmental toxicity studies, and the relatively low NOAELs and the nature of the hazard identified in the sub-chronic tests provides an alert

  17. Effect of electromagnetic field exposure on the reproductive system

    OpenAIRE

    Gye, Myung Chan; Park, Chan Jin

    2012-01-01

    The safety of human exposure to an ever-increasing number and diversity of electromagnetic field (EMF) sources both at work and at home has become a public health issue. To date, many in vivo and in vitro studies have revealed that EMF exposure can alter cellular homeostasis, endocrine function, reproductive function, and fetal development in animal systems. Reproductive parameters reported to be altered by EMF exposure include male germ cell death, the estrous cycle, reproductive endocrine h...

  18. Society for Assisted Reproductive Technology

    Science.gov (United States)

    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 ...

  19. Comparative toxicant sensitivity of sexual and asexual reproduction in the rotifer Brachionus calyciflorus

    Energy Technology Data Exchange (ETDEWEB)

    Snell, T.W. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Biology; Carmona, M.J. [Univ. de Valencia (Spain). Area de Ecologia

    1995-03-01

    Cyclically parthenogenetic zooplankters like rotifers are important tools for assessing toxicity in aquatic environments. Sexual reproduction is an essential component of rotifer life cycles, but current toxicity tests utilize only asexual reproduction. The authors compared the effects of four toxicants on asexual and sexual reproduction of the rotifer Brachionus calyciflorus. Toxicants had a differential effect on sexual and asexual reproduction, with sexual reproduction consistently the most sensitive. Concentrations of 0.2 {mu}g/ml PCP (sodium pentachlorophenate) had no effect on the asexual reproductive rate, but significantly reduced sexual reproduction. Likewise, chlorpyrifos concentrations of 0.3 {mu}g/ml had no significant effect on asexual reproduction, but sexual reproduction was significantly reduced. There was no difference in NOECs, LOECs, and chronic values for asexual and sexual reproduction for cadmium and naphthol tests. However, comparison of toxicant effect levels revealed that sexual reproduction was more strongly reduced at each toxicant concentration. The four toxicants tested inhibited sexual reproduction 2 to 68 times more than asexual reproduction at the lowest observed effect concentrations. Toxicants inhibited sexual reproduction in its initial step: sexual female production. Because sexual reproduction is more sensitive, toxicity tests based exclusively on asexual reproduction may not be protective of rotifer life cycles.

  20. Crowding by a repeating pattern.

    Science.gov (United States)

    Rosen, Sarah; Pelli, Denis G

    2015-01-01

    Theinability to recognize a peripheral target among flankers is called crowding. For a foveal target, crowding can be distinguished from overlap masking by its sparing of detection, linear scaling with eccentricity, and invariance with target size.Crowding depends on the proximity and similarity of the flankers to the target. Flankers that are far from or dissimilar to the target do not crowd it. On a gray page, text whose neighboring letters have different colors, alternately black and white, has enough dissimilarity that it might escape crowding. Since reading speed is normally limited by crowding, escape from crowding should allow faster reading. Yet reading speed is unchanged (Chung & Mansfield, 2009). Why? A recent vernier study found that using alternating-color flankers produces strong crowding (Manassi, Sayim, & Herzog, 2012). Might that effect occur with letters and reading? Critical spacing is the minimum center-to-center target-flanker spacing needed to correctly identify the target. We measure it for a target letter surrounded by several equidistant flanker letters of the same polarity, opposite polarity, or mixed polarity: alternately white and black. We find strong crowding in the alternating condition, even though each flanker letter is beyond its own critical spacing (as measured in a separate condition). Thus a periodic repeating pattern can produce crowding even when the individual elements do not. Further, in all conditions we find that, once a periodic pattern repeats (two cycles), further repetition does not affect critical spacing of the innermost flanker.

  1. Paternal smoking habits affect the reproductive life span of daughters

    DEFF Research Database (Denmark)

    Fukuda, Misao; Fukuda, Kiyomi; Shimizu, Takashi

    2011-01-01

    The present study assessed whether the smoking habits of fathers around the time of conception affected the period in which daughters experienced menstrual cycles (i.e., the reproductive life span). The study revealed that the smoking habits of the farther shortened the daughters' reproductive li...

  2. The Pentapeptide Repeat Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Vetting,M.; Hegde, S.; Fajardo, J.; Fiser, A.; Roderick, S.; Takiff, H.; Blanchard, J.

    2006-01-01

    The Pentapeptide Repeat Protein (PRP) family has over 500 members in the prokaryotic and eukaryotic kingdoms. These proteins are composed of, or contain domains composed of, tandemly repeated amino acid sequences with a consensus sequence of [S, T,A, V][D, N][L, F]-[S, T,R][G]. The biochemical function of the vast majority of PRP family members is unknown. The three-dimensional structure of the first member of the PRP family was determined for the fluoroquinolone resistance protein (MfpA) from Mycobacterium tuberculosis. The structure revealed that the pentapeptide repeats encode the folding of a novel right-handed quadrilateral {beta}-helix. MfpA binds to DNA gyrase and inhibits its activity. The rod-shaped, dimeric protein exhibits remarkable size, shape and electrostatic similarity to DNA.

  3. Reproductive tract microbiome in assisted reproductive technologies.

    Science.gov (United States)

    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.

  4. Repeating the Past

    Science.gov (United States)

    Moore, John W.

    1998-05-01

    As part of the celebration of the Journal 's 75th year, we are scanning each Journal issue from 25, 50, and 74 years ago. Many of the ideas and practices described are so similar to present-day "innovations" that George Santayana's adage (1) "Those who cannot remember the past are condemned to repeat it" comes to mind. But perhaps "condemned" is too strong - sometimes it may be valuable to repeat something that was done long ago. One example comes from the earliest days of the Division of Chemical Education and of the Journal.

  5. Reducing multiple births in assisted reproduction technology.

    Science.gov (United States)

    Bhattacharya, Siladitya; Kamath, Mohan S

    2014-02-01

    Multiple pregnancy, a complication of assisted reproduction technology, is associated with poorer maternal and perinatal outcomes. The primary reason behind this is the strategy of replacing more than one embryo during an assisted reproduction technology cycle to maximise pregnancy rates. The solution to this problem is to reduce the number of embryos transferred during in-vitro fertilisation. The transition from triple- to double-embryo transfer, which decreased the risk of triplets without compromising pregnancy rates, was easily implemented. The adoption of a single embryo transfer policy has been slow because of concerns about impaired pregnancy rates in a fresh assisted reproduction technology cycle. Widespread availability of effective cryopreservation programmes means that elective single embryo transfer, along with subsequent frozen embryo transfers, could provide a way forward. Any such strategy will need to consider couples' preferences and existing funding policies, both of which have a profound influence on decision making around embryo transfer.

  6. Reproductive endocrinology and biotechnology applications among buffaloes.

    Science.gov (United States)

    Madan, M L; Prakash, B S

    2007-01-01

    Buffalo, as the major livestock species for milk and meat production, contribute significantly to the economy of many countries in south & south-east Asia, South America, Africa and the Mediterranean. Improved buffalo production could significantly enhance the economy and the living standards of farmers in countries where buffaloes predominate; particularly, in countries with a tropical climate. The major factors limiting the efficient utilization of buffaloes in countries with a tropical climate are: late maturity; poor estrus expressivities, particularly in summer months; long postpartum calving intervals; low reproductive efficiencies and fertility rates which are closely linked with environmental stress; as well as managerial problems. As good reproductive performance is essential for efficient livestock production, the female buffalo calves must grow rapidly to attain sexual maturity, initiate estrous cycles, ovulate and be mated by fertile males or inseminated with quality semen to optimize conception and production. In the last two decades, considerable attention has been focused on understanding some of the causes for the inherent limitations in reproduction among buffaloes by studying their reproductive endocrinology as well as developing biotechniques for augmenting their reproductive efficiency. This review provides an overview of buffalo reproductive endocrinology and also of the research done to date towards the enhancement of buffalo reproductive efficiency through endocrine and embryo biotechniques.

  7. All-optical repeater.

    Science.gov (United States)

    Silberberg, Y

    1986-06-01

    An all-optical device containing saturable gain, saturable loss, and unsaturable loss is shown to transform weak, distorted optical pulses into uniform standard-shape pulses. The proposed device performs thresholding, amplification, and pulse shaping as required from an optical repeater. It is shown that such a device could be realized by existing semiconductor technology.

  8. Bidirectional Manchester repeater

    Science.gov (United States)

    Ferguson, J.

    1980-01-01

    Bidirectional Manchester repeater is inserted at periodic intervals along single bidirectional twisted pair transmission line to detect, amplify, and transmit bidirectional Manchester 11 code signals. Requiring only 18 TTL 7400 series IC's, some line receivers and drivers, and handful of passive components, circuit is simple and relatively inexpensive to build.

  9. NTP-CERHR expert panel report on the reproductive anddevelopmental toxicity of hydroxyurea

    Energy Technology Data Exchange (ETDEWEB)

    Liebelt, E.L.; Balk, S.J.; Faber, W.; Fisher, J.W.; Hughes, C.L.; Lanzkron, S.M.; Lewis, K.M.; Marchetti, F.; Mehendale, H.M.; Rogers,J.M.; Shad, A.T.; Skalko, R.G.; Stanek, E.J.

    2007-01-01

    The National Toxicology Program (NTP) and the National Institute of Environmental Health Sciences (NIEHS) established the NTP Center for the Evaluation of Risks to Human Reproduction (CERHR) in June 1998. The purpose of CERHR is to provide timely, unbiased, scientifically sound evaluations of human and experimental evidence for adverse effects on reproduction and development caused by agents to which humans may be exposed. Hydroxyurea was selected for evaluation by a CERHR expert panel because of (1) its increasing use in the treatment of sickle cell disease in children and adults, (2) knowledge that it inhibits DNA synthesis and is cytotoxic, and (3) published evidence of its reproductive and developmental toxicity in rodents. Hydroxyurea is FDA-approved for reducing the frequency of painful crises and the need for blood transfusions in adults with sickle cell anemia who experience recurrent moderate-to-severe crises. Hydroxyurea is used in the treatment of cancer, sickle cell disease, and thalassemia. It is the only treatment for sickle cell disease aside from blood transfusion used in children. Hydroxyurea may be used in the treatment of children and adults with sickle cell disease for an extended period of time or for repeated cycles of therapy. Treatment with hydroxyurea may be associated with cytotoxic and myelosuppressive effects, and hydroxyurea is mutagenic.

  10. Preconception care: promoting reproductive planning

    Science.gov (United States)

    2014-01-01

    Introduction Preconception care recognizes that many adolescent girls and young women will be thrust into motherhood without the knowledge, skills or support they need. Sixty million adolescents give birth each year worldwide, even though pregnancy in adolescence has mortality rates at least twice as high as pregnancy in women aged 20-29 years. Reproductive planning and contraceptive use can prevent unintended pregnancies, unsafe abortions and sexually-transmitted infections in adolescent girls and women. Smaller families also mean better nutrition and development opportunities, yet 222 million couples continue to lack access to modern contraception. Method A systematic review and meta-analysis of the evidence was conducted to ascertain the possible impact of preconception care for adolescents, women and couples of reproductive age on MNCH outcomes. A comprehensive strategy was used to search electronic reference libraries, and both observational and clinical controlled trials were included. Cross-referencing and a separate search strategy for each preconception risk and intervention ensured wider study capture. Results Comprehensive interventions can prevent first pregnancy in adolescence by 15% and repeat adolescent pregnancy by 37%. Such interventions should address underlying social and community factors, include sexual and reproductive health services, contraceptive provision; personal development programs and emphasizes completion of education. Appropriate birth spacing (18-24 months from birth to next pregnancy compared to short intervals adolescent health and preventing adolescent pregnancy; and promotion of birth spacing through increasing correct and consistent use of effective contraception are fundamental to preconception care. Promoting reproductive planning on a wider scale is closely interlinked with the reliable provision of effective contraception, however, innovative strategies will need to be devised, or existing strategies such as community

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

    Science.gov (United States)

    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)

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

    Science.gov (United States)

    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)

  13. Repeated-sprint and effort ability in rugby league players.

    Science.gov (United States)

    Johnston, Rich D; Gabbett, Tim J

    2011-10-01

    The aim of this study was to (a) investigate the influence of tackling on repeated-sprint performance; (b) determine whether repeated-sprint ability (RSA) and repeated-effort ability (REA) are 2 distinct qualities; and (c) assess the test-retest reliability of repeated-sprint and repeated-effort tests in rugby league. Twelve rugby league players performed a repeated-sprint (12 × 20-m sprints performed on a 20-second cycle) and a repeated-effort (12 × 20-m sprints with intermittent tackling, performed on a 20-second cycle) test 7 days apart. The test-retest reliability of these tests was also established. Heart rate and rating of perceived exertion were recorded throughout the tests. There was a significantly greater (p ≤ 0.05) and large effect size (ES) differences for total sprint time (ES = 1.19), average heart rate (ES = 1.64), peak heart rate (ES = 1.35), and perceived exertion (ES = 3.39) for the repeated-effort test compared with the repeated-sprint test. A large difference (ES = 1.02, p = 0.06) was detected for percentage decrement between the 2 tests. No significant relationship was found between the repeated-sprint and repeated-effort tests for any of the dependent variables. Both tests proved reliable, with total sprint time being the most reliable method of assessing performance. This study demonstrates that the addition of tackling significantly increases the physiological response to repeated-sprint exercise and reduces repeated-sprint performance in rugby league players. Furthermore, RSA and REA appear to be 2 distinct qualities that can be reliably assessed with total time being the most reliable measure of performance.

  14. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  15. Menstrual Cycle

    Science.gov (United States)

    ... Luteal (after egg release) Changes During the Menstrual Cycle The menstrual cycle is regulated by the complex interaction of ... egg release) Luteal (after egg release) The menstrual cycle begins with menstrual bleeding (menstruation), which marks the first day of ...

  16. Reproductive and fat body cycles of Tropidurus hispidus and Tropidurus semitaeniatus (Squamata, Tropiduridae in a caatinga area of northeastern Brazil Ciclos reproductivos y de grasa corporal de Tropidurus hispidus y Tropidurus semitaeniatus (Squamata, Tropiduridae en una área de caatinga del nordeste de Brasil

    Directory of Open Access Journals (Sweden)

    LEONARDO B. RIBEIRO

    2012-09-01

    Full Text Available This study assessed the reproductive and fat body cycles of Tropidurus hispidus (Spix, 1825 and T. semitaeniatus (Spix, 1825 in an area of caatinga in the Serido of Rio Grande do Norte, Brazil, from October 2006 to May 2008. In both species, the females were reproductively active from the middle of the dry season to the beginning of the rainy season. Female reproductive activity was influenced by precipitation, whereas males exhibited spermatozoa in their testes throughout the year, and their reproductive activity was not related to any of the climatic variables analyzed. Mean clutch size (± SD was 8.1 ± 2.0 and 2.1 ± 0.6 eggs in T. hispidus and T. semitaeniatus, respectively, and was significantly related to female body size only in T. hispidus. The fat stock varied inversely with reproductive activity in the two species, and there was no difference in fat body mass between females and males. The effects of precipitation on the length of the breeding season of these two Tropidurus species suggest that their reproductive cycles are related to the microclimatic conditions suitable for embryo development, as well as for the neonates' emergence and survival especially during the rainy season, which may offer greater food availability to the hatchlings.Este estudio evaluó los ciclos reproductivos y de grasa corporal de Tropidurus hispidus (Spix, 1825 y T. semitaeniatus (Spix, 1825 en una área de caatinga en el Seridó de Rio Grande do Norte, Brasil, de octubre de 2006 a mayo de 2008. En ambas especies, las hembras se encontraron reproductivamente activas a partir de mediados de la estación seca para el inicio de la temporada de lluvias. La actividad reproductiva de las hembras fue influenciada por las precipitaciones, mientras que los machos presentaron espermatozoides en los testículos durante todo el año, y su actividad reproductiva no fue relacionada con ninguna de las variables climáticas analizadas. El tamaño medio (± DE de la nidada

  17. CAG repeat polymorphism in androgen receptor gene is not directly associated with polycystic ovary syndrome but influences serum testosterone levels.

    Science.gov (United States)

    Skrgatic, L; Baldani, D Pavicic; Cerne, J Z; Ferk, P; Gersak, K

    2012-02-01

    Hyperandrogenemia has been the most consistent feature of polycystic ovary syndrome (PCOS). Androgens exert their effects through androgen receptors (ARs). The expansion of the codon CAG trinucleotide repeat polymorphism in exon 1 of the AR gene represents a type of genetic alteration associated with changes in the AR gene function. The purpose of this study was to establish a possible association of the AR gene CAG repeat length polymorphism with PCOS, and its influence on clinical and biochemical androgen traits. Two hundred and fourteen Croatian women with PCOS and 209 healthy control women of reproductive age were enrolled. Phenotypic hyperandrogenism, BMI and waist to hip ratio were recorded. Hormonal profiles, fasting insulin and glucose levels were measured on cycle days 3-5. Genotyping of the CAG repeat polymorphism in the AR gene was performed. We found no significant difference in the mean CAG repeat number between the PCOS patients and controls (22.1±3.4 vs. 21.9±3.2, P=0.286). There was a positive correlation between the CAG repeat length and total testosterone (TT) in the PCOS group (R=0.225, P=0.015). A multiple linear regression model using mean CAG repeat length, BMI, age and HOMA-IR as predictors explained 8.5% (adjusted R²) of the variability in serum TT levels. In this model the CAG repeat polymorphism was found to be a significant predictor of serum TT levels in PCOS patients (P=0.015). The logistic regression analysis revealed that the CAG repeat length is not a significant predictor of hirsutism and acne status (P=0.921 and P=0.437, respectively). The model was adjusted for serum TT, free testosterone, androstendione and DHEAS levels as independent variables, which were also not found to be significant predictors of hirsutism (P=0.687, P=0.194, P=0.675 and P=0.938, respectively) or acne status (P=0.594, P=0.095, P=0.290 and P=0.151, respectively). In conclusion, the AR CAG repeat polymorphism is not a major determinant of PCOS in the

  18. Asexual Reproduction in Holothurians

    OpenAIRE

    Igor Yu. Dolmatov

    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 holot...

  19. Phenology of sexual reproduction in the common coral reef sponge, Carteriospongia foliascens

    Science.gov (United States)

    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 (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.

  20. Popular myths in reproductive immunology.

    Science.gov (United States)

    Clark, David A

    2014-10-01

    According to Mark Twain, "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." Four items believed by reproductive immunologists are analyzed. (1) In a semiallogeneic (outbred) mating, maternofetal tolerance is required to prevent immune rejection manifesting as infertility, recurrent pregnancy loss, preeclampsia and fetal growth restriction. (2) Regulation of natural killer (NK) cells at the fetomaternal interface by interaction with fetal trophoblast paternal class I MHC is obligatory for pregnancy success. (3) Failure of angiogenesis triggered by complement activation is a key mechanism in pregnancy pathology. (4) Randomized controlled (double-blind) clinical trials and systematic reviews exemplified by the Cochrane database provide reliable evidence on which to base treatment and promulgate guidelines. Those who heed not the lessons of history are doomed to repeat the same mistakes in the future. History shows that we do this and expect a different outcome.

  1. Reproductive and developmental toxicology

    National Research Council Canada - National Science Library

    Gupta, Ramesh C

    2011-01-01

    .... Reproductive and Developmental Toxicology is a comprehensive and authoritative resource providing the latest literature enriched with relevant references describing every aspect of this area of science...

  2. Plantas relacionadas con tabúes del ciclo reproductivo de los Guaraníes de Misiones, Argentina Plants related to taboos of the reproductive cycle of guaranies from Misiones, Argentina

    Directory of Open Access Journals (Sweden)

    Héctor A Keller

    2010-06-01

    Full Text Available Los guaraníes de las parcialidades Mbya y Ava Chiripa observan normas de conducta específicas durante la etapa reproductiva de los miembros de sus comunidades. Algunas de estas reglas implican tabúes que se relacionan con plantas, las cuales son tratadas en la presente contribución. El manuscrito es ilustrado mediante fotografías de algunas de las especies mencionadas.Guaranis of Mbya and Ava Chiripa groups, observes norms of specific conduct during the reproductive stage of the members of his communities. Someone of these rules imply taboos related with plants, these plants are treated in the present contribution. The manuscript is illustrated by means photographies of someone of the mentioned species.

  3. Influence of Paternal Age on Assisted Reproduction Outcome

    Science.gov (United States)

    2017-04-27

    We Will Retrospectively Assess Our Databases in Our Clinic; Instituto Valenciano de Infertilidad in Valencia (Spain); Searching for Assisted Reproduction Procedures; IUI Standard IVF/ICSI Cycles and Ovum Donation IVF/ICSI Cycles; Who Were Referred to Our Unit to Cryopreserve Sperm During the Period; From January 2000 to December 2006

  4. Repeatability of Cryogenic Multilayer Insulation

    Science.gov (United States)

    Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

    2017-01-01

    Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between multiple identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five GRC provided coupons with 25 layers was shown to be +/- 8.4 whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0. A second group of 10 coupons have been fabricated by Yetispace and tested by Florida State University, through the first 4 tests, the repeatability has been shown to be +/- 16. Based on detailed statistical analysis, the data has been shown to be statistically significant.

  5. In-vitro cervical mucus-sperm penetration tests and outcome of infertility treatments in couples with repeatedly negative post-coital tests.

    Science.gov (United States)

    Farhi, J; Valentine, A; Bahadur, G; Shenfield, F; Steele, S J; Jacobs, H S

    1995-01-01

    The results of in-vitro cervical mucus-sperm penetration tests and cross-hostility tests in 178 couples with repeatedly negative post-coital tests were recorded. Using a protocol of three cycles with intra-uterine inseminations (IUI) followed by three cycles with ovulation induction + IUI, the association between the cause of infertility, results of the in-vitro tests and the outcome of infertility treatment was investigated. We found that repeatedly negative post-coital tests are a good indicator of a cervical mucus-sperm penetration problem. The cross-hostility test clearly differentiates the abnormal factor in this interaction, and a good performance of the donors' spermatozoa in the cervical mucus correlates with increased pregnancy rate. In male factor infertility, failure of the husbands' spermatozoa to penetrate cervical mucus was not indicative of a deficient fertilization potential in vivo. In these patients a serious attempt should therefore be made to reverse the infertility by treatment with IUI or ovulation induction + IUI before attempting assisted reproduction. Women with polycystic ovaries and repeatedly negative post-coital tests should be investigated for sperm receptivity of the cervical mucus. Low receptivity of the cervical mucus may imply that endometrial receptivity and oocyte quality are also low. Ovulation induction and not IUI alone should therefore be used as the preferred mode of treatment to improve pregnancy rate.

  6. Reproductive experience alters neural and behavioural responses to acute oestrogen receptor α activation.

    Science.gov (United States)

    Byrnes, E M; Casey, K; Carini, L M; Bridges, R S

    2013-12-01

    Reproductive experience (i.e. parturition and lactation) leads to persistent alterations in anxiety-like behaviour that are influenced by the oestrous cycle. We recently found that repeated administration of the selective oestrogen receptors (ER)α agonist propyl-pyrazole triol (PPT) results in anxiolytic-like behaviours on the elevated plus maze (EPM) in primiparous (but not nulliparous) female rats. The present study examined the effects of the acute administration of PPT on EPM behaviour in primiparous and aged-matched, nulliparous female rats. In addition, corticosterone secretion, corticotrophin-releasing hormone (CRH) gene expression and expression of the immediate early gene product Fos in the paraventricular nucleus (PVN) and amygdala were measured either after EPM testing or in home cage controls. Acute PPT administration significantly modified EPM behaviour as a function of reproductive experience, with nulliparous females tending toward increased anxiety-like behaviours and primiparous females tending toward decreased anxiety-like behaviours. In home cage controls, PPT increased corticosterone secretion in all females; however, both vehicle- and PPT-treated, primiparous females had reduced corticosterone levels compared to their nulliparous counterparts. Significant effects of PPT on CRH mRNA within the PVN were observed after the administration of PPT but only in primiparous females tested on the EPM. PPT also increased Fos expression within the PVN of EPM-exposed females; however, both vehicle- and PPT-treated primiparous females had reduced Fos expression compared to nulliparous females. In the amygdala, PPT increased Fos immunoreactivity in the central but not the medial or basolateral amygdala, although these effects were only observed in home cage females. Additionally, both vehicle- and PPT-treated home cage, primiparous females had increased Fos in the central nucleus of the amygdala compared to nulliparous controls. Overall, these data

  7. Experimentally Induced Repeated Anhydrobiosis in the Eutardigrade Richtersius coronifer

    Science.gov (United States)

    2016-01-01

    Tardigrades represent one of the main animal groups with anhydrobiotic capacity at any stage of their life cycle. The ability of tardigrades to survive repeated cycles of anhydrobiosis has rarely been studied but is of interest to understand the factors constraining anhydrobiotic survival. The main objective of this study was to investigate the patterns of survival of the eutardigrade Richtersius coronifer under repeated cycles of desiccation, and the potential effect of repeated desiccation on size, shape and number of storage cells. We also analyzed potential change in body size, gut content and frequency of mitotic storage cells. Specimens were kept under non-cultured conditions and desiccated under controlled relative humidity. After each desiccation cycle 10 specimens were selected for analysis of morphometric characteristics and mitosis. The study demonstrates that tardigrades may survive up to 6 repeated desiccations, with declining survival rates with increased number of desiccations. We found a significantly higher proportion of animals that were unable to contract properly into a tun stage during the desiccation process at the 5th and 6th desiccations. Also total number of storage cells declined at the 5th and 6th desiccations, while no effect on storage cell size was observed. The frequency of mitotic storage cells tended to decline with higher number of desiccation cycles. Our study shows that the number of consecutive cycles of anhydrobiosis that R. coronifer may undergo is limited, with increased inability for tun formation and energetic constraints as possible causal factors. PMID:27828978

  8. Reproduction in laboratory of the morphology distribution and orientation of hydrides in different stages fuel cycle; Reproduccion en laboratorio de la morfologia, distribucion y orientacion de hidruros en distintas etapas del ciclo de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Rengel, M. A.; Gomez, F. J.; Ruiz-Hervias, J.

    2013-07-01

    In this paper, the experimental techniques employed to reproduce in the laboratory the distribution, morphology and orientation of the hydrides during the different steps of the nuclear fuel cycle are reported. A cathodic charging technique was employed to produce ZIRLO cladding samples with an homogeneous distribution of hydrides and concentrations of 150, 250, 500, 1200 and 2000 ppm of hydrogen. The treatments developed to produce radial hydride reorientation, hydride blisters and a peripheral rim of hydrides are described.

  9. [Hormonal stimulation of reproductive function in swine].

    Science.gov (United States)

    Hladkova, A I

    1993-01-01

    Industrial conditions, gynaecological disorders, ovarian deficiency being unfavourable factors for pigs reproduction, as well as the necessity in rapid sex maturation require thorough knowledge on physiology of reproduction processes. The importance belongs to the hormonal treatment in development of special biotechnological methods. Efficiency of the latter is determined by the kind of hormone used, its dose, injection time in sex cycle and the knowledge of species specificity of physiological regulation of reproductive processes in pigs of great value. The achievements in this country and abroad, devoted to the technology of oestrogens, gestagens, androgens and their combinations as well as gonadotropins (PMS, CG), gonadotropin-releasing hormone applications have been reviewed. The most often used schemes of hormonal treatment and drugs, as well as the results obtained have been described. The data presented can be used for needs of practical cattle-breeding.

  10. Selective Reproductive Technologies

    DEFF Research Database (Denmark)

    Gammeltoft, Tine; Wahlberg, Ayo

    2014-01-01

    selective reproduction has been placed under the aegis of science and expertise in novel ways. New laboratory and clinical techniques allow for the selective fertilization of gametes, implantation of embryos, or abortion of fetuses. Although they will often overlap with assisted reproductive technologies...

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

    Science.gov (United States)

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

    2016-01-01

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

  12. Níveis de fibra da dieta sobre o desempenho de coelhas no primeiro e segundo ciclos reprodutivos - DOI: 10.4025/actascianimsci.v26i1.1930 Dietary fiber levels on rabbit does’ performance on the first and second reproductive cycles - DOI: 10.4025/actascianimsci.v26i1.1930

    Directory of Open Access Journals (Sweden)

    Jeffrey Frederico Lui

    2004-04-01

    Full Text Available Este experimento teve por objetivo estudar os efeitos dos níveis de fibra em detergente ácido (15,1%; 17,9%; 20,6%; 23,0% da dieta sobre o desempenho de 64 coelhas da raça Nova Zelândia Branco, nos dois primeiros ciclos reprodutivos. As dietas continham 2850 kcal/kg de ED, 19,8% de PB e 28,8% de amido. No primeiro ciclo, o consumo diário apresentou variação quadrática (p0,05 sobre o tamanho das ninhadas. Dietas mais fibrosas promoveram uma maior produção de leite (pThe experiment aimed to evaluate the effects of dietary acid detergent fiber levels (15.1; 17.9; 20.6; 23.0% ADF on the performance of 64 New Zealand White rabbit does, during first and second reproductive cycles. The experimental diets contained 2850 kcal/kg digestive energy (DE, 19.8% crude protein (CP and 28.8% starch. In the first cycle, the feed intake in pregnancy presented quadratic variation (P0.05 of treatments on litter size. More fibrous diets provided greater milk production (P<0.02.

  13. To cope with new problems of energy situation (Part 1); Entering into new phase of international petroleum situation. Repeated feasibility of petroleum cycle. Energy josei no atarashii kadai ni ikani taio suruka (Kenkyu hokuko 1); Shin kyokumen ni hairu kokusai sekiyu josei. Kurikaesuka sekiyu cycle

    Energy Technology Data Exchange (ETDEWEB)

    Toichi, Tsutomu (The Inst. of Energy Economics, Tokyo, (Japan))

    1990-02-01

    It is recognized that similarity exists between world economics, crude oil price, production of crude oil by OPEC and non-OPEC countries, importation of oil by USA. environmental problems, of 1973, just before oil crisis, and those of 1986. World economics has been growing rapidly in later half of 1980s, though it is not so rapid as that just before the first oil crisis. Hovering oil price in recent years has been contributing to activate world economics in later half of 1980s, just like as directly before the first oil crisis. By considering such petroleum cycle, it was verified from various view points that petroleum market was entering into new phase of upward swing toward 1990s. 4 figs., 9 tabs.

  14. Non-invasive assessment of the reproductive cycle in free-ranging female African elephants (Loxodonta africana treated with a gonadotropin-releasing hormone (GnRH vaccine for inducing anoestrus

    Directory of Open Access Journals (Sweden)

    Benavides Valades Gabriela

    2012-08-01

    Full Text Available Abstract Background In southern Africa, various options to manage elephant populations are being considered. Immunocontraception is considered to be the most ethically acceptable and logistically feasible method for control of smaller and confined populations. In this regard, the use of gonadotropin-releasing hormone (GnRH vaccine has not been investigated in female elephants, although it has been reported to be safe and effective in several domestic and wildlife species. The aims of this study were to monitor the oestrous cycles of free-ranging African elephant cows using faecal progestagen metabolites and to evaluate the efficacy of a GnRH vaccine to induce anoestrus in treated cows. Methods Between May 2009 - June 2010, luteal activity of 12 elephant cows was monitored non-invasively using an enzyme immunoassay detecting faecal 5alpha-reduced pregnanes (faecal progestagen metabolites, FPM on a private game reserve in South Africa. No bulls of breeding age were present on the reserve prior to and for the duration of the study. After a 3-month control period, 8 randomly-selected females were treated twice with 600 micrograms of GnRH vaccine (Improvac®, Pfizer Animal Health, Sandton, South Africa 5-7 weeks apart. Four of these females had been treated previously with the porcine zona pellucida (pZP vaccine for four years (2004-2007. Results All 12 monitored females (8 treated and 4 controls showed signs of luteal activity as evidenced by FPM concentrations exceeding individual baseline values more than once. A total of 16 oestrous cycles could be identified in 8 cows with four of these within the 13 to 17 weeks range previously reported for captive African elephants. According to the FPM concentrations the GnRH vaccine was unable to induce anoestrus in the treated cows. Overall FPM levels in samples collected during the wet season (mean 4.03 micrograms/gram dry faeces were significantly higher (P Conclusions The GnRH vaccination protocol failed

  15. The future of human reproduction

    National Research Council Canada - National Science Library

    Overall, Christine

    1989-01-01

    ... Contradictions III SOCIAL POLICY QUESTIONS Pregnancy as Justification for Loss of Juridical Autonomy Sanda Rodgers 174 Prenatal Diagnosis: Reproductive Choice? Reproductive Control? Abby Lippman ...

  16. Biogeochemical Cycling

    Science.gov (United States)

    Bebout, Brad; Fonda, Mark (Technical Monitor)

    2002-01-01

    This lecture will introduce the concept of biogeochemical cycling. The roles of microbes in the cycling of nutrients, production and consumption of trace gases, and mineralization will be briefly introduced.

  17. Gender issues in reproductive health: a review.

    Science.gov (United States)

    Adinma, Echendu D; Adinma, Brian-D J I

    2011-01-01

    Gender, for its impact on virtually every contemporary life issue, can rightly be regarded as a foremost component of reproductive health. Reproductive health basically emphasises on people and their rights to sexuality, reproduction, and family planning, and the information to actualize these right, which has been inextricably linked to development at the International Conference on Population and Development (ICPD) held in Cairo, Egypt, in 1994. Women's sexual and reproductive rights became recognised as universal human right, violations of which occur in some reproductive health areas including gender concerns. Gender inequality and inequity encompass gender based violence as well as gender discrimination which cuts across the life cycle of the woman; attitudes, religious and cultural practices of various nations; and issues related to employment, economy, politics, and development. The redress of gender inequality is a collective responsibility of nations and supranational agencies. Nations should adopt a framework hinged on three pedestals--legal, institutional and policy, employing the three recommended approaches of equal treatment, positive action, and gender mainstreaming.

  18. TRIENNIAL REPRODUCTION SYMPOSIUM: Developmental programming of fertility.

    Science.gov (United States)

    Reynolds, L P; Vonnahme, K A

    2016-07-01

    The 2015 Triennial Reproduction Symposium focused on developmental programming of fertility. The topics covered during the morning session included the role of the placenta in programming of fetal growth and development, effects of feeding system and level of feeding during pregnancy on the annual production cycle and lifetime productivity of heifer offspring, effects of litter size and level of socialization postnatally on reproductive performance of pigs, effects of postnatal dietary intake on maturation of the hypothalamic-pituitary-gonadal axis and onset of puberty in heifers, effects of housing systems on growth performance and reproductive efficiency of gilts, and effects of energy balance on sexual differentiation in rodent models. The morning session concluded with presentation of the American Society of Animal Science L. E. Casida Award for Excellence in Graduate Education to Dr. Michael Smith from the University of Missouri, Columbia, who shared his philosophy of graduate education. The afternoon session included talks on the role of epigenetic modifications in developmental programming and transgenerational inheritance of reproductive dysfunction, effects of endocrine disrupting compounds on fetal development and long-term physiology of the individual, and potential consequences of real-life exposure to environmental contaminants on reproductive health. The symposium concluded with a summary talk and the posing of 2 questions to the audience. From an evolutionary standpoint, programming and epigenetic events must be adaptive; when do they become maladaptive? If there are so many environmental factors that induce developmental programming, are we doomed, and if not, what is or are the solution or solutions?

  19. Cell biology solves mysteries of reproduction.

    Science.gov (United States)

    Sutovsky, Peter

    2012-09-01

    Reproduction and fertility have been objects of keen inquiry since the dawn of humanity. Medieval anatomists provided the first accurate depictions of the female reproductive system, and early microscopists were fascinated by the magnified sight of sperm cells. Initial successes were achieved in the in vitro fertilization of frogs and the artificial insemination of dogs. Gamete and embryo research was in the cradle of modern cell biology, providing the first evidence of the multi-cellular composition of living beings and pointing out the importance of chromosomes for heredity. In the 20th century, reproductive research paved the way for the study of the cytoskeleton, cell signaling, and the cell cycle. In the last three decades, the advent of reproductive cell biology has brought us human in vitro fertilization, animal cloning, and human and animal embryonic stem cells. It has contributed to the development of transgenesis, proteomics, genomics, and epigenetics. This Special Issue represents a sample of the various areas of reproductive biology, with emphasis on molecular and cell biological aspects. Advances in spermatology, ovarian function, fertilization, and maternal-fetal interactions are discussed within the framework of fertility and diseases such as endometriosis and diabetes.

  20. Reproductive biology of the pampas deer (Ozotoceros bezoarticus: a review

    Directory of Open Access Journals (Sweden)

    Olazabal Daniel

    2008-06-01

    Full Text Available Abstract The pampas deer (Ozotoceros bezoarticus is a South American grazing deer which is in extreme danger of extinction. Very little is known about the biology of the pampas deer. Moreover, most information has not been published in peer-reviewed scientific journals, and is only available in local publications, theses, etc. Therefore, our aim was to update and summarize the available information regarding the reproductive biology of the pampas deer. Moreover, in most sections, we have also included new, unpublished information. Detailed descriptions are provided of the anatomy of both the female and the male reproductive tract, puberty onset, the oestrous cycle and gestational length. Birthing and the early postpartum period are described, as are maternal behaviour and early fawn development, seasonal distribution of births, seasonal changes in male reproduction and antler cycle, reproductive behaviour, semen collection, and cryopreservation. Finally, an overview is given and future directions of research are proposed.

  1. Endocrinology of human female sexuality, mating, and reproductive behavior.

    Science.gov (United States)

    Motta-Mena, Natalie V; Puts, David A

    2016-11-17

    Hormones orchestrate and coordinate human female sexual development, sexuality, and reproduction in relation to three types of phenotypic changes: life history transitions such as puberty and childbirth, responses to contextual factors such as caloric intake and stress, and cyclical patterns such as the ovulatory cycle. Here, we review the endocrinology underlying women's reproductive phenotypes, including sexual orientation and gender identity, mate preferences, competition for mates, sex drive, and maternal behavior. We highlight distinctive aspects of women's sexuality such as the possession of sexual ornaments, relatively cryptic fertile windows, extended sexual behavior across the ovulatory cycle, and a period of midlife reproductive senescence-and we focus on how hormonal mechanisms were shaped by selection to produce adaptive outcomes. We conclude with suggestions for future research to elucidate how hormonal mechanisms subserve women's reproductive phenotypes.

  2. Marijuana, the Endocannabinoid System and the Female Reproductive System

    Science.gov (United States)

    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

  3. From tropical to sub-tropical: Prolonged reproductive activity of the invasive ascidian Microcosmus exasperatus in the eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    Lilach Raijman Nagar

    2016-08-01

    Full Text Available The solitary ascidian Microcosmus exasperatus is globally distributed in tropical and sub-tropical waters. In the Mediterranean it is considered an invasive species introduced through the Suez Canal, with a restricted distribution in the eastern basin. In order to understand the potential of this species to establish sustainable communities at additional sites in the Mediterranean, we studied its reproduction cycle over a 2-year period in relation to seawater temperature and chlorophyll-a data. Although M. exasperatus reproduces seasonally, with significantly greater activity in summer and early fall, mature oocytes occur throughout the year, suggesting multiple spawning periods. We found that reproductive effort significantly correlated with seawater temperature, while chlorophyll-a showed a low and insignificant explanatory power. A combined regression model of both parameters yielded the highest explained variance, suggesting a synergic effect of these two factors. Such a prolonged reproductive activity period enables repeated recruitment events. In view of the anticipated rise in seawater temperature, we predict that this species will gradually expand its distribution further across the Mediterranean.

  4. Selective Reproductive Technologies

    DEFF Research Database (Denmark)

    Gammeltoft, Tine; Wahlberg, Ayo

    2014-01-01

    selective reproduction has been placed under the aegis of science and expertise in novel ways. New laboratory and clinical techniques allow for the selective fertilization of gametes, implantation of embryos, or abortion of fetuses. Although they will often overlap with assisted reproductive technologies...... (ARTs), what we term selective reproductive technologies (SRTs) are of a more specific nature: Rather than aiming to overcome infertility, they are used to prevent or allow the birth of certain kinds of children. This review highlights anthropological research into SRTs in different parts of the world...

  5. The pineal gland - Its possible roles in human reproduction

    Science.gov (United States)

    Brzezinski, Amnon; Wurtman, Richard J.

    1988-01-01

    The paper discusses the role of the pineal gland in controlling mammalian reproduction, with particular attention given to the role of melatonin in polyestrus mammals, like humans and laboratory rodents. Evidence is cited indicating the influence of melatonin production and blood content on the age of puberty, the timing of the ovulatory cycle, gonadal steriodogenesis, and patterns of reproductive behavior. It is suggested that abnormal patterns of melatonin might be associated with amenorrhea, anovulation, unexplained infertility, premature menopause, and habitual abortions.

  6. Lysophosphatidic Acid (LPA Signaling in Human and Ruminant Reproductive Tract

    Directory of Open Access Journals (Sweden)

    Izabela Wocławek-Potocka

    2014-01-01

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

  7. Reproductive data of Squalus cubensis collected from Gulf of Mexico from 2005-01-10 to 2012-12-03 (NCEI Accession 0150633)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Reproductive data from Squalus cubensis (Cuban dogfish) were opportunistically collected from 2005-2012. Data include those necessary to examine reproductive cycle,...

  8. Society of Reproductive Surgeons

    Science.gov (United States)

    ... affiliated society to the American Society for Reproductive Medicine . Below are links to publications authored by ASRM and its affiliated societies. Latest Additions: Diagnostic Testing for Male Factor Infertility Robotic surgery The Intrauterine Device (IUD): A Long-acting ...

  9. Reproductive prognosis in endometriosis

    DEFF Research Database (Denmark)

    Hjordt Hansen, Maj V; Dalsgaard, Torur; Hartwell, Dorthe

    2014-01-01

    OBJECTIVE: To assess the reproductive long-term prognosis of women with and without endometriosis, to explore changes over time, and to quantify the contribution of artificial reproductive techniques. DESIGN: Cohort study. SETTING: Denmark 1977-2009. SAMPLE: Data retrieved from four national...... registries. Among 15-49-year-old women during the period 1977-82, 24 667 were diagnosed with endometriosis and 98 668 (1:4) women without endometriosis were age-matched. METHODS: To assess long-term reproductive prognosis, all pregnancy outcomes were identified among the women with and without endometriosis......, but this was restricted to pregnancies from assisted reproduction. CONCLUSION: Women with endometriosis have slightly fewer children, but this lessened over time due to artificially conceived pregnancies. The risk for miscarriages and ectopic pregnancies was increased compared with women without the disease....

  10. Pregnancy and Reproductive Issues

    Science.gov (United States)

    ... Relationships Pregnancy Share this page Facebook Twitter Email Pregnancy and Reproductive Issues Tahirah Diagnosed in 2003 Pregnancy ... in control groups without the disease. Effects of pregnancy on MS Before 1950, most women with MS ...

  11. Teaching Plant Reproduction.

    Science.gov (United States)

    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)

  12. Reproductive data for groundfish

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The ROCKFISH database houses data from rockfish species collected by the SWFSC FED along the California coast as part of a reproductive study originating in the...

  13. Expansion of protein domain repeats.

    Directory of Open Access Journals (Sweden)

    Asa K Björklund

    2006-08-01

    Full Text Available Many proteins, especially in eukaryotes, contain tandem repeats of several domains from the same family. These repeats have a variety of binding properties and are involved in protein-protein interactions as well as binding to other ligands such as DNA and RNA. The rapid expansion of protein domain repeats is assumed to have evolved through internal tandem duplications. However, the exact mechanisms behind these tandem duplications are not well-understood. Here, we have studied the evolution, function, protein structure, gene structure, and phylogenetic distribution of domain repeats. For this purpose we have assigned Pfam-A domain families to 24 proteomes with more sensitive domain assignments in the repeat regions. These assignments confirmed previous findings that eukaryotes, and in particular vertebrates, contain a much higher fraction of proteins with repeats compared with prokaryotes. The internal sequence similarity in each protein revealed that the domain repeats are often expanded through duplications of several domains at a time, while the duplication of one domain is less common. Many of the repeats appear to have been duplicated in the middle of the repeat region. This is in strong contrast to the evolution of other proteins that mainly works through additions of single domains at either terminus. Further, we found that some domain families show distinct duplication patterns, e.g., nebulin domains have mainly been expanded with a unit of seven domains at a time, while duplications of other domain families involve varying numbers of domains. Finally, no common mechanism for the expansion of all repeats could be detected. We found that the duplication patterns show no dependence on the size of the domains. Further, repeat expansion in some families can possibly be explained by shuffling of exons. However, exon shuffling could not have created all repeats.

  14. Physiological control of growth, reproduction and lactation in deer

    Directory of Open Access Journals (Sweden)

    Morten Ryg

    1986-06-01

    Full Text Available The physiological mechanisms controlling the growth, lactation and reproductive cycles of cervids, and the control of allocation of energy to different organs are discussed. The growth cycle may be secondary to an appetite cycle, regulated by changes in the secretion of prolactin, gonadal steroids, and possibly unknown factors. The reproductive cycle is controlled by changes in the release at the hypothalamic hormone GnRH, and by changes in the feedback effect of gonadal steroids. These cycles are probably the result of the timing effects of nutrition and changing photoperiod on an endogenous, circannual rhythm. The effect of photopenod is mediated by the pineal hormone melatonin. The physiological mechanisms controlling the partitioning of substrates between milk production, fetal growth and the tissues of the mother are poorly understood, but may involve changes in the secretion of growth hormone, insulin and triiodothyronine.

  15. FEEDING INDEX AND REPRODUCTIVE CYCLE IN MALE RED-PIAU Leporinus copelandii (STEINDACHNER, 1875 IN THE LOW BASIN OF PARAIBA DO SUL RIVER ÍNDICES DE ALIMENTAÇÃO E CICLO REPRODUTIVO EM MACHOS DE PIAU-VERMELHO Leporinus copelandii (STEINDACHNER, 1875 NA BACIA DO BAIXO RIO PARAÍBA DO SUL

    Directory of Open Access Journals (Sweden)

    Manuel Vazquez Vidal Jr.

    2007-12-01

    Full Text Available

    The aim of this article was evaluate de relationship among feeding index and reproductive cycle in male red-piau (Leporinus copelandii, in the low basin of paraiba do sul river. Fishes were collected monthly, from February 1998 to march 1999, and obtained the following param-eters: total condition factor (k1 and somatic (k2, stomach repletion index (SRI and stomach repletion stage (SRS, and gonadal maturation. in general, condition and gonadal parameters showed an inverse relation with nutritional parameters. during the spawning season (september to January, was observed low values of SRS and SRI, fol-lowing an increase of these parameters after spawning, and it seems to be a natural mechanism of corporal condition recovering.

    Key-Words: Leporinus, fish, reproduction, reproductive biology.

    Objetivou-se com este trabalho avaliar a relação entre índices de alimentação e ciclo reprodutivo de machos de piau-vermelho, na região do baixo rio Paraíba do Sul (latitude 21° 41’ 15” S e longitude 42° 03’ 45” W. amostras foram coletadas mensalmente, entre fevereiro de 1998 a janeiro de 1999, sendo obtidos os seguintes parâmetros: fator de condição total (k1 e somático (k2, índice gastro-somático (IGas e estádio de repleção estomacal (ERE, e estádios de maturação gonadal. em geral, parâmetros de condição corporal e gônadas apresentaram uma relação inversamente proporcional aos parâmetros de alimentação. durante a estação reprodutiva (setembro–janeiro, foram observados os menores valores de IGas e ERE, seguidos por um incremento desses parâmetros após a reprodução, mostrando ser um mecanismo natural de reposição da condição corporal.

    Palavras-chaves: biologia reprodutiva, Leporinus, peixe, reprodução.

  16. Reproductive rights approach to reproductive health in developing countries

    OpenAIRE

    2011-01-01

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

  17. Avian reproductive physiology

    Science.gov (United States)

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

    1995-01-01

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

  18. Thyroid and male reproduction

    Directory of Open Access Journals (Sweden)

    Anand Kumar

    2014-01-01

    Full Text Available Male reproduction is governed by the classical hypothalamo-hypophyseal testicular axis: Hypothalamic gonadotropin releasing hormone (GnRH, pituitary luteinizing hormone (LH and follicle stimulating hormone (FSH and the gonadal steroid, principally, testosterone. Thyroid hormones have been shown to exert a modulatory influence on this axis and consequently the sexual and spermatogenic function of man. This review will examine the modulatory influence of thyroid hormones on male reproduction.

  19. DWI Repeaters and Non-Repeaters: A Comparison.

    Science.gov (United States)

    Weeber, Stan

    1981-01-01

    Discussed how driving-while-intoxicated (DWI) repeaters differed signigicantly from nonrepeaters on 4 of 23 variables tested. Repeaters were more likely to have zero or two dependent children, attend church frequently, drink occasionally and have one or more arrests for public intoxication. (Author)

  20. To Repeat or Not to Repeat a Course

    Science.gov (United States)

    Armstrong, Michael J.; Biktimirov, Ernest N.

    2013-01-01

    The difficult transition from high school to university means that many students need to repeat (retake) 1 or more of their university courses. The authors examine the performance of students repeating first-year core courses in an undergraduate business program. They used data from university records for 116 students who took a total of 232…

  1. Asexual reproduction in holothurians.

    Science.gov (United States)

    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.

  2. The Natural Reproduction and Economic Reproduction of Agriculture

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In the perspective of Marx’s materialism,the thesis expounds the natural reproduction and economic reproduction of agriculture,and analyzes the relationship between the two production processes.The natural reproduction of agriculture,the contradicted unification of agricultural organism and natural environment,conforms to natural law and has the specific objective environmental requirements.The economic reproduction of agriculture is the process of people’s production and labor which takes keeping the life vitality of agricultural organism as objective,including the reproduction of agricultural productivity and the reproduction of agricultural production relations.The agricultural productivity comprises social productivity and natural productivity.The process of agricultural economic reproduction must conform to the objective natural law and economic law.The relationship of agricultural natural reproduction and economic reproduction is that the agricultural natural reproduction process is intertwined with economic reproduction process;the variation trend of agricultural natural reproduction ability and economic reproduction ability is identical;the agricultural economic reproduction dominates over the natural reproduction.

  3. 长方案IVF/ICSI周期中获卵数与助孕结局的关系%Relationship between Numbers of Retrieved Oocytes and Outcomes of Assisted Reproduction in IVF/ICSI Cycles

    Institute of Scientific and Technical Information of China (English)

    倪佳; 黄静; 何钰辉; 柳胜贤

    2015-01-01

    目的:研究和分析长方案体外受精-胚胎移植(IVF/ICSI-ET)周期不同获卵数目与受精率、卵裂率、优质胚胎率、周期冷冻率、移植胚胎数、着床率、临床妊娠率之间的关系。方法:对本院生殖中心2011年1月-2012年12月实施长方案有获卵的共786个IVF/ICSI-ET新鲜周期进行回顾性总结和分析,根据不同获卵数分为五组(A组1~4枚,B组5~10枚,C组11~15枚,D组16~20枚,E组>20枚),比较各组年龄、受精率、卵裂率、优质胚胎率、周期冷冻率、移植胚胎数及临床妊娠率。结果:获卵数随年龄增加呈下降趋势,但五组年龄、移植胚胎数比较差异无统计学意义(P>0.05);五组受精率、卵裂率、优质胚胎率、冷冻周期率及临床妊娠率比较差异均有统计学意义(P0.05).However,the differences in fertilization rates, cleavage rates,good quality embryo rates,freezing cycle rates and clinical pregnancy rates of the five groups were statistically significant(P<0.01).Group C had the highest clinical pregnancy rates while group A had the lowest.The clinical pregnancy rates of group B and D were higher than those in group E.Conclusion:In IVF/ICSI cycles,if we have the same number of effectively transferred embryos,the number of retrieved oocytes is closely related to laboratory indexes and clinical pregnancy rates.The best clinical outcome can be reached by obtaining a modest number of oocytes.

  4. PCR-free digital minisatellite tandem repeat genotyping.

    Science.gov (United States)

    Chen, Yuchao; Seo, Tae Seok

    2011-06-01

    We demonstrated a proof-of-concept for novel minisatellite tandem repeat typing, called PCR-free digital VNTR (variable number tandem repeat) typing, which is composed of three steps: a ligation reaction instead of PCR thermal cycling, magnetic bead-based solid-phase capture for purification, and an elongated sample stacking microcapillary electrophoresis (μCE) for sensitive digital coding of repeat number. We designed a 16-bp fluorescently labeled ligation probe which is complementary to a repeat unit of a biotinylated synthetic template mimicking the human D1S80 VNTR locus and is randomly hybridized with the minisatellite tandem repeats. A quick isothermal ligation reaction was followed to link the adjacent ligation probes on the DNA templates, and then the ligated products were purified by streptavidin-coated magnetic beads. After a denaturing step, a large amount of ligated products whose size difference was equivalent to the repeat unit were released and recovered. Through the elongated sample stacking μCE separation on a microdevice, the fluorescence signal of the ligated products was generated in the electropherogram and the peak number was directly counted which was exactly matched with the repeat number of VNTR locus. We could successfully identify the minisatellite tandem repeat number with only 5 fmol of DNA template in 30 min.

  5. Effects of Yupei Qisun Sequential Method of Chinese Medicine on Correlated Indices of Repeated Implantation Fallure Patients in the Fresh Cycle%中医预培其损序贯疗法对胚胎反复移植失败患者新鲜周期相关指标的影响

    Institute of Scientific and Technical Information of China (English)

    于莎; 匡延平; 齐聪

    2012-01-01

    Objective To study the clinical effects of Yupei Qisun Sequential Method (YQSM, by Shen supplementing and Pi invigorating) of Chinese medicine on correlated indices of repeated implantation failure patients in the fresh cycle. Methods Sixty patients with more than three failure cycles of in virto fertilization and embryo transfer (IVF-ET) or intracytoplasmic sperm injection (ICSI) were recruited. They were assigned to the treatment group (treated by IVF/ICSI and Chinese medicine) and the control group (treated by IVF/ICSI alone), 30 in each group. The total dose of gonadotropin (Gn), the days of controlled ovary hyperstimulation (COH), the thickness of endometrium on the day of embryo transplantation, the number of retrieved oocytes, the fertilization number, the embryo number, the high quality embryo number, the pregnancy rate, and the implantation rate were compared. Results In the treatment group the numbers of embryo and high quality embryo were 7.5 ±4.9 and 5.1 ±3.2 respectively, which were both higher than those of the control group with significant difference (5.1 ±3.2, 3.2 ±1.8; P0.05). Conclusion YQSM combined with COH could improve the quantity and the quality of embryos, which was promising to increase the accumulative pregnancy rate of RIF patients.%目的 探讨中医(补肾健脾)预培其损序贯疗法对胚胎反复移植失败(repeated implantation failure,RIF)患者新鲜周期相关指标的影响.方法 将既往行体外受精-胚胎移植(in virto fertilization and embryo transfer,IVF-ET)或卵母细胞单精子显微注射(intracytoplasmic sperm injection,ICSI)失败3次及以上的患者,行新鲜取卵/移植周期共60例,分为治疗组(中药结合IVF/ICSI)与对照组(单纯IVF/ICSI),每组30例,比较两组外源性促性腺激素(gonadotropin,Gn)用量、超排卵(controlled ovarian hyperstimulation,COH)时间、移植日子宫内膜厚度、获得卵数、受精数、胚胎数、优质胚胎数、妊娠率及种植率

  6. FES cycling.

    Science.gov (United States)

    Newham, D J; Donaldson, N de N

    2007-01-01

    Spinal cord injury (SCI) leads to a partial or complete disruption of motor, sensory, and autonomic nerve pathways below the level of the lesion. In paraplegic patients, functional electrical stimulation (FES) was originally widely considered as a means to restore walking function but this was proved technically very difficult because of the numerous degrees of freedom involved in walking. FES cycling was developed for people with SCI and has the advantages that cycling can be maintained for reasonably long periods in trained muscles and the risk of falls is low. In the article, we review research findings relevant to the successful application of FES cycling including the effects on muscle size, strength and function, and the cardiovascular and bone changes. We also describe important practical considerations in FES cycling regarding the application of surface electrodes, training and setting up the stimulator limitations, implanted stimulators and FES cycling including FES cycling in groups and other FES exercises such as FES rowing.

  7. Nifty Nines and Repeating Decimals

    Science.gov (United States)

    Brown, Scott A.

    2016-01-01

    The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how…

  8. Nifty Nines and Repeating Decimals

    Science.gov (United States)

    Brown, Scott A.

    2016-01-01

    The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how…

  9. Repeated Prolonged Exercise Decreases Maximal Fat Oxidation in Older Men

    DEFF Research Database (Denmark)

    Morville, Thomas; Rosenkilde, Mads; Munch-Andersen, Thor

    2017-01-01

    INTRODUCTION/PURPOSE: Fat metabolism and muscle adaptation was investigated in 6 older trained men (age: 61 ± 4 years; VO2max: 48 ± 2 mL kg min) following repeated prolonged exercise). METHODS: 2706 km (1,681 miles) cycling was performed over 14 days and a blood sample and a muscle biopsy were...

  10. Wages and employment in a repeated game with revenue fluctuations

    DEFF Research Database (Denmark)

    Schultz, Christian

    1997-01-01

    Empirical investigations suggests that the real wage is surprisingly flat over the business cycle. This paper analyses a repeated game between a union and a firm which can contribute to explaining the flat wage. The parties cannot enter binding contracts, and revenue is fluctuating. The paper...

  11. Glucocorticoid Regulation of Reproduction.

    Science.gov (United States)

    Geraghty, Anna C; Kaufer, Daniela

    2015-01-01

    It is well accepted that stress, measured by increased glucocorticoid secretion, leads to profound reproductive dysfunction. In times of stress, glucocorticoids activate many parts of the fight or flight response, mobilizing energy and enhancing survival, while inhibiting metabolic processes that are not necessary for survival in the moment. This includes reproduction, an energetically costly procedure that is very finely regulated. In the short term, this is meant to be beneficial, so that the organism does not waste precious energy needed for survival. However, long-term inhibition can lead to persistent reproductive dysfunction, even if no longer stressed. This response is mediated by the increased levels of circulating glucocorticoids, which orchestrate complex inhibition of the entire reproductive axis. Stress and glucocorticoids exhibits both central and peripheral inhibition of the reproductive hormonal axis. While this has long been recognized as an issue, understanding the complex signaling mechanism behind this inhibition remains somewhat of a mystery. What makes this especially difficult is attempting to differentiate the many parts of both of these hormonal axes, and new neuropeptide discoveries in the last decade in the reproductive field have added even more complexity to an already complicated system. Glucocorticoids (GCs) and other hormones within the hypothalamic-pituitary-adrenal (HPA) axis (as well as contributors in the sympathetic system) can modulate the hypothalamic-pituitary-gonadal (HPG) axis at all levels-GCs can inhibit release of GnRH from the hypothalamus, inhibit gonadotropin synthesis and release in the pituitary, and inhibit testosterone synthesis and release from the gonads, while also influencing gametogenesis and sexual behavior. This chapter is not an exhaustive review of all the known literature, however is aimed at giving a brief look at both the central and peripheral effects of glucocorticoids on the reproductive function.

  12. DEP and AFO regulate reproductive habit in rice.

    Directory of Open Access Journals (Sweden)

    Kejian Wang

    2010-01-01

    Full Text Available Sexual reproduction is essential for the life cycle of most angiosperms. However, pseudovivipary is an important reproductive strategy in some grasses. In this mode of reproduction, asexual propagules are produced in place of sexual reproductive structures. However, the molecular mechanism of pseudovivipary still remains a mystery. In this work, we found three naturally occurring mutants in rice, namely, phoenix (pho, degenerative palea (dep, and abnormal floral organs (afo. Genetic analysis of them indicated that the stable pseudovivipary mutant pho was a double mutant containing both a Mendelian mutation in DEP and a non-Mendelian mutation in AFO. Further map-based cloning and microarray analysis revealed that dep mutant was caused by a genetic alteration in OsMADS15 while afo was caused by an epigenetic mutation in OsMADS1. Thus, OsMADS1 and OsMADS15 are both required to ensure sexual reproduction in rice and mutations of them lead to the switch of reproductive habit from sexual to asexual in rice. For the first time, our results reveal two regulators for sexual and asexual reproduction modes in flowering plants. In addition, our findings also make it possible to manipulate the reproductive strategy of plants, at least in rice.

  13. All-photonic quantum repeaters

    Science.gov (United States)

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-01-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories. PMID:25873153

  14. No Additional Benefit of Repeat-Sprint Training in Hypoxia than in Normoxia on Sea-Level Repeat-Sprint Ability

    Science.gov (United States)

    Goods, Paul S.R.; Dawson, Brian; Landers, Grant J.; Gore, Christopher J.; Peeling, Peter

    2015-01-01

    To assess the impact of ‘top-up’ normoxic or hypoxic repeat-sprint training on sea-level repeat-sprint ability, thirty team sport athletes were randomly split into three groups, which were matched in running repeat-sprint ability (RSA), cycling RSA and 20 m shuttle run performance. Two groups then performed 15 maximal cycling repeat-sprint training sessions over 5 weeks, in either normoxia (NORM) or hypoxia (HYP), while a third group acted as a control (CON). In the post-training cycling RSA test, both NORM (13.6%; p = 0.0001, and 8.6%; p = 0.001) and HYP (10.3%; p = 0.007, and 4.7%; p = 0.046) significantly improved overall mean and peak power output, respectively, whereas CON did not change (1.4%; p = 0.528, and -1.1%; p = 0.571, respectively); with only NORM demonstrating a moderate effect for improved mean and peak power output compared to CON. Running RSA demonstrated no significant between group differences; however, the mean sprint times improved significantly from pre- to post-training for CON (1.1%), NORM (1.8%), and HYP (2.3%). Finally, there were no group differences in 20 m shuttle run performance. In conclusion, ‘top-up’ training improved performance in a task-specific activity (i.e. cycling); however, there was no additional benefit of conducting this ‘top-up’ training in hypoxia, since cycle RSA improved similarly in both HYP and NORM conditions. Regardless, the ‘top-up’ training had no significant impact on running RSA, therefore the use of cycle repeat-sprint training should be discouraged for team sport athletes due to limitations in specificity. Key points ‘Top-up’ repeat-sprint training performed on a cycle ergometer enhances cycle repeat-sprint ability compared to team sport training only in football players. The addition of moderate hypoxia to repeat-sprint training provides no additional performance benefits to sea-level repeat-sprint ability or endurance performance than normoxic repeat-sprint training.

  15. No Additional Benefit of Repeat-Sprint Training in Hypoxia than in Normoxia on Sea-Level Repeat-Sprint Ability.

    Science.gov (United States)

    Goods, Paul S R; Dawson, Brian; Landers, Grant J; Gore, Christopher J; Peeling, Peter

    2015-09-01

    To assess the impact of 'top-up' normoxic or hypoxic repeat-sprint training on sea-level repeat-sprint ability, thirty team sport athletes were randomly split into three groups, which were matched in running repeat-sprint ability (RSA), cycling RSA and 20 m shuttle run performance. Two groups then performed 15 maximal cycling repeat-sprint training sessions over 5 weeks, in either normoxia (NORM) or hypoxia (HYP), while a third group acted as a control (CON). In the post-training cycling RSA test, both NORM (13.6%; p = 0.0001, and 8.6%; p = 0.001) and HYP (10.3%; p = 0.007, and 4.7%; p = 0.046) significantly improved overall mean and peak power output, respectively, whereas CON did not change (1.4%; p = 0.528, and -1.1%; p = 0.571, respectively); with only NORM demonstrating a moderate effect for improved mean and peak power output compared to CON. Running RSA demonstrated no significant between group differences; however, the mean sprint times improved significantly from pre- to post-training for CON (1.1%), NORM (1.8%), and HYP (2.3%). Finally, there were no group differences in 20 m shuttle run performance. In conclusion, 'top-up' training improved performance in a task-specific activity (i.e. cycling); however, there was no additional benefit of conducting this 'top-up' training in hypoxia, since cycle RSA improved similarly in both HYP and NORM conditions. Regardless, the 'top-up' training had no significant impact on running RSA, therefore the use of cycle repeat-sprint training should be discouraged for team sport athletes due to limitations in specificity. Key points'Top-up' repeat-sprint training performed on a cycle ergometer enhances cycle repeat-sprint ability compared to team sport training only in football players.The addition of moderate hypoxia to repeat-sprint training provides no additional performance benefits to sea-level repeat-sprint ability or endurance performance than normoxic repeat-sprint training.'Top-up' cycling repeat-sprint training

  16. Biochemical changes in relation to the breeding cycles of Nausitora hedleyi Schepman (Bivalvia: Teredinidae)

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswathy, M.; Nair, N.B.

    The biochemical changes in relation to the breeding cycles of Nausitora hedleyi - a typical estuarine boring bivalve were studied. The systematic variations in the annual reproductive cycle were also determined. Samples were collected from Cochin...

  17. Reproductive Hormones and Mood Disorders

    Directory of Open Access Journals (Sweden)

    Sermin Kesebir

    2010-12-01

    Full Text Available During the menstrual cycle, pregnancy and breast-feeding periods, as well as in menopausal and post-menopausal periods, the physiological and psychological processes that change according to the hormonal fluctuations influence every women similarly and each one differently. These physiological processes are controlled by neuroendocrine sequences, of which the hypothalamo-pituitary-adrenal axis and the hypothalamo-pituitary-gonadal axis are the most important ones. The hypothalamo-pituitary-gonadal axis affects mood, anxiety, cognition and pain. The interaction of these hormones with mood and behavior is bidirectional. The differences in phenomenology and epidemiology of mood disorders with regards to gender can be explained with the effects of hormones. All of the periods mentioned above are related with mood disorders at terms of risk factors, disease symptoms, progress of disease and response to treatment. Epidemiologic data supports the relationship between the mood disorders and reproductive processes. The prevalence of major depression increases in women with the menarche and ceases in post- menopausal period. Similarly, the initial symptoms of bipolar disorder begins around the menarche period in 50% of the cases. Despite proper treatment, some female patients with major depression experience recurrence during the premenstrual period of their menstrual cycles. The conformity and change in a woman’s brain during pregnancy is controlled dominantly by the neuroendocrine systems, while it is controlled by the external stimuli actively related to the baby during nursing period. The changes that occur are closely related to postpartum mood disorders. Again, all the changes and suspension of medication during this procedure are risk factors for early depressive and dysphoric situations. Variables of a wide range, from follicle stimulating hormone, melatonin, and sleep to body mass index interact with mood disorders in menopausal and post

  18. Altruism and Reproductive Limitations

    Directory of Open Access Journals (Sweden)

    Carey J. Fitzgerald

    2009-04-01

    Full Text Available We examined how different types of reproductive limitations — functional (schizoid personality disorder and schizophrenia, physical (malnutrition, and sexual (bisexuality and homosexuality — influenced altruistic intentions toward hypothetical target individuals of differing degrees of relatedness (r = 0, .25, and .50. Participants were 312 undergraduate students who completed a questionnaire on altruism toward hypothetical friends, half-siblings, and siblings with these different types of reproductive limitations. Genetic relatedness and reproductive limitations did not influence altruistic decision-making when the cost of altruism was low but did as the cost of altruism increased, with participants being more likely to help a sibling over a half-sibling and a half-sibling over a friend. Participants also indicated they were more likely to help a healthy (control person over people with a reproductive limitation. Of the three types of reproductive limitations, functional limitations had the strongest effect on altruistic decision-making, indicating that people were less likely to help those who exhibit abnormal social behavior.

  19. Adipokines in human reproduction.

    Science.gov (United States)

    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.

  20. Life-cycle of the European compost worm Dendrobaena veneta ...

    African Journals Online (AJOL)

    1990-06-05

    Jun 5, 1990 ... The life-cycle of Dendrobaena veneta was studied to assess the potential ... development, growth and reproduction were investigated by rearing worms at ..... systems.Agric. Wmles 2: 43--60. RAMISCH. H. & GRAFF. o. 1985.

  1. Cloning of partial cDNA of estrogen receptor α and expression analysis during the reproductive cycle in Navodon septentrionalis%绿鳍马面鲀ERα基因部分cDNA序列克隆及其表达研究

    Institute of Scientific and Technical Information of China (English)

    赵梅琳; 温海深; 张冬茜; 何峰; 李吉方

    2014-01-01

    Estrogens are critical sex steroid hormones involved in reproduction. And they need to bind to estrogen receptors (ER) in target organ for biological activity. To explore the physiological function of estrogen receptor α(ERα) in Navodon septentrionalis and provide some theoretical basis for artificial breeding, a partial cDNA sequence of N. septentrionalis ERαgene was obtained by degenerate primer PCR amplification. The length of the cDNA sequence is 1410 bp, and encodes 470 amino acids. The tissue expression analysis using semi-quantitative RT-PCR showed that it had a more restricted distribution in male fish. In female, pituitary, heart and ovary had high expression levels, and in male, pituitary, liver, kidney and testis had relatively high expression levels. In addition, we analyzed the relative expression level of ERαin reproductive cycle in ovary and testis by quantitative RT-PCR, respectively. It revealed that the highest expression level was in May, and the lowest in July in ovary, while in testis, the lowest was in May, and the highest in September. This study indicates that ERαhas a strong relationship with the reproductive cycle of N. septentrionalis, suggesting ERαshould play a role in gonads development.%雌二醇是与生殖相关的重要的性类固醇激素之一,它与雌激素受体相结合作用于靶器官从而发挥生物活性。为进一步鲀阐明绿鳍马面雌激素受体α(Estrogen receptorα, ERα)的生理功能提供了科学依据,同时也为其人工繁育提供一定的理论基础,作者利用简并引物扩增得到绿鳍马面鲀(Navodon septentrionalis)ERα部分cDNA序列,共1410bp,编码470个氨基酸。通过半定量RT-PCR技术分别检测了其在雌鱼、雄鱼中各组织的表达情况,结果表明 ERα在雌鱼体内的表达较雄鱼更广泛,在雌鱼垂体、心脏和卵巢的表达量最高,在雄鱼的垂体、肝脏、肾脏、精巢也有较高的表达。采用实时定量RT-P C R技术,分析了ER

  2. [Reproduction and interferogenic activity of togaviruses].

    Science.gov (United States)

    Emel'ianov, B A; Novokhatskiĭ, A S

    1977-01-01

    A comparative study of the correlation between reproduction and the interferon-inducing activity of viruses in chick embryo fibroblast cultures was carried out with members of different groups of togaviruses: alphavirus (Venezuelan equin encephalomyelitis viru, VEE) and flavivirus (Saint Louis encephalitis virus, SLE). The correspondence between cycles of accumulation of intracellular and extracellular viruses and the dynamics of interferon production the synthesis of which began early in the stage of exponential virus growth and correlated with the dynamics of their reproduction, was determined. Reproduction of the viruses was found to be directly dependent upon the multiplicity of infection; optimal infecting doses for the induction of the largest amounts of interferon were established. The calculations of the reproductive activity of VEE and SLE viruses showed their yield per one cell to be approximately 10,000 PFU and 1,000 LD50, respectively. Partial thermal inactivation of the viruses resulted in decreased yields of the infectious virus and interferon production. The regimen of thermal inactivation at which infectivity was lost completely, but the interferon-inducing capacity was retained probably due to residual synthesis of viral RNA was established for VEE virus. From the fact that the pattern of realization of genetic information is similar for both viruses, a similar mechanism of interferon synthesis induction is assumed.

  3. Relationships between intrauterine infusion of N-acetylcysteine, equine endometrial pathology, neutrophil function, post-breeding therapy, and reproductive performance.

    Science.gov (United States)

    Gores-Lindholm, Alicia R; LeBlanc, Michelle M; Causey, Robert; Hitchborn, Anna; Fayrer-Hosken, Richard A; Kruger, Marius; Vandenplas, Michel L; Flores, Paty; Ahlschwede, Scott

    2013-08-01

    Persistent endometritis in the mare is associated with hypersecretion of mucus by endometrial epithelium and migration of neutrophils into the uterine lumen. This study examines the relationships between N-acetylcysteine (NAC), a mucolytic agent with anti-inflammatory properties, and endometrial architecture, serum neutrophil function, post-breeding therapy, and reproductive performance of NAC-treated mares in a clinical setting. In study 1, endometrial biopsies from mares receiving intrauterine saline (fertile-control, n = 6) or 3.3% NAC (fertile-treatment, n = 6; barren-treatment, n = 10) were evaluated by histology and image analysis. In study 2, phagocytic activity of serum-derived neutrophils was measured after adding 0.5% or 3% NAC. In study 3, pregnancy rates of repeat breeders (n = 44) receiving an intrauterine infusion of 3.3% NAC 24-36 hours before mating (group 1) was recorded, as was first cycle of the season pregnancy rates of reproductively normal mares (group 2, n = 85), and mares treated for bacterial endometritis the cycle before mating (group 3, n = 25). Intrauterine NAC did not adversely affect endometrial histology. Extracellular mucus thickness and staining intensity were reduced in fertile-treatment mares (P NAC solution, but not by 0.5% NAC (P NAC was not irritating and inhibited the oxidative burst of neutrophils. Repeat breeder mares, with evidence of mucus hypersecretion, but no uterine pathogens, when treated with NAC followed by post-mating uterine lavage and oxytocin (and in some cases intrauterine antibiotics), achieved a pregnancy rate of 77%.

  4. Dinosaur Reproduction and Parenting

    Science.gov (United States)

    Horner, John R.

    Non-avian dinosaur reproductive and parenting behaviors were mostly similar to those of extant archosaurs. Non-avian dinosaurs were probably sexually dimorphic and some may have engaged in hierarchical rituals. Non-avian coelurosaurs (e.g. Troodontidae, Oviraptorosauria) had two active oviducts, each of which produced single eggs on a daily or greater time scale. The eggs of non-coelurosaurian dinosaurs (e.g. Ornithischia, Sauropoda) were incubated in soils, whereas the eggs of non-avian coelurosaurs (e.g. Troodon, Oviraptor) were incubated with a combination of soil and direct parental contact. Parental attention to the young was variable, ranging from protection from predators to possible parental feeding of nest-bound hatchlings. Semi-altricial hadrosaur hatchlings exited their respective nests near the time of their first linear doubling. Some reproductive behaviors, once thought exclusive to Aves, arose first in non-avian dinosaurs. The success of the Dinosauria may be related to reproductive strategies.

  5. Major reproductive health problems of indigenous Borena cows in Ethiopia

    Directory of Open Access Journals (Sweden)

    Ararsa Duguma Benti

    2014-12-01

    Full Text Available The study was conducted to identify the major reproductive health problems and its associated risk factors in indigenous Borena breed cows in Borena zone in Southern Ethiopia between September 2013 and February 2014. Out of the total 409 cows examined, 195 (47.7% were having at least one of the reproductive problems identified by either questionnaire interview (n=329 or regular follow up (n=80 of individual cows. The major reproductive health problems identified in the present study were mastitis (21.3%; n=87/409, abortion (12.2%; n=50/409, repeat breeder (10.3%; n=42/409, anestrus (10.3%; n=42/409 and retained fetal membrane (RFM; 7.6%; n=31/409. The rate of abortion increased significantly (p=0.001 with the increase in the stage of gestation. Laboratory findings indicated that brucellosis and mastitis had great roles in reproductive health problems of dairy cows in the study area with prevalence rates of 2.91% and 68.41%, respectively. In conclusion, the study revealed that several reproductive health problems such as mastitis, abortion, repeat breeder, anestrus and RFM are mostly prevalent in dairy cows in Borena zone in southern Ethiopia.

  6. Reproductive biology of the Amazon Lava Lizard (Tropidurus torquatus) from the Wet Chaco of Corrientes (Argentina): congeneric comparisons of ecotypic and interspecific variations

    National Research Council Canada - National Science Library

    Ortiz, M.A; Boretto, J.M; Piantoni, C; Alvarez, B.B; Ibarguengoytia, N.R

    2014-01-01

    ... of T. torquatus and congeneric species. In Corrientes, males of T. torquatus exhibited a continuous reproductive cycle, but with annual variation of testicular parameters associated with spermatogenic activity...

  7. CHEMICALS AND REPRODUCTIVE HEALTH

    Directory of Open Access Journals (Sweden)

    Omer Faruk TEKBAS

    2006-02-01

    Full Text Available However a lot of chemicals had been used in our daily life, we have enough knowledge about the effects of only for a small portion of them on reproductive health. Our knowledge had been arisen from epidemiologic and experimental studies. In order to protect ourselves from chemicals in the environment it should be concentrate on experimental studies and the results of them should be carefully studied during epidemiological researches. It would be tried to tell about the main chemicals which had been known as effective on reproductive health on the following review. [TAF Prev Med Bull 2006; 5(1.000: 50-59

  8. Robotics in reproductive medicine.

    Science.gov (United States)

    Sroga, Julie; Patel, Sejal Dharia; Falcone, Tommaso

    2008-01-01

    In the past decade, robotic technology has been increasingly incorporated into various industries, including surgery and medicine. This chapter will review the history, development, current applications, and future of robotic technology in reproductive medicine. A literature search was performed for all publications regarding robotic technology in medicine, surgery, reproductive endocrinology, and its role in both surgical education and telepresence surgery. As robotic assisted surgery has emerged, this technology provides a feasible option for minimally invasive surgery, impacts surgical education, and plays a role in telepresence surgery.

  9. The reproductive ecology of the house mouse.

    Science.gov (United States)

    Bronson, F H

    1979-09-01

    This paper attempts to integrate the physiological and ecological perspectives of the reproductive biology of the house mouse (Mus musculus). The endeavor is made within a larger context to provide a prototype for mammalian reproductive ecology in general. Specifically, the environmental regulation of the reproduction of Mus musculus is examined in relation to its ecological opportunism and, in particular, in relation to its history of global colonization. House mice can live as commensals of man or under totally feral conditions. Stable, high density, commensal populations are characterized by an insular division of the living space into demeterritories, each dominated by a single male. Feral populations typically are characterized by temporal, spatial, and social instability. Territoriality is improbable under such conditions, particularly given the necessity for large home ranges in most feral habitats. In both feral and commensal populations, however, male aggressiveness promotes the large-scale dispersal of young, all of which are potential colonizers. Of the ten or so environmental factors known to influence reproduction in house mice, seven probably are of routine importance in natural populations: diurnal modulation by daily light:dark cycles; caloric intake; nutrition; extreme temperature; agaonistic stimuli; socio-tactile cues; and priming pheronomes. The last two factors named operate directly on the secretion of luteinizing hormone or prolactin; the others act at many points in the reproductive system. Reproduction in the house mouse seems divorced from photoperiodically induced seasonality; indeed, this species breeds well even in constant darkness. Seasonal breeding may or may not then occur, depending upon dietary considerations, with or without a secondary interaction with variation in ambient temperature. There is no evidence for a dependence upon secondary plant compounds. Some of the effects of priming pheromones that have been observed

  10. Reprodução de Lytechinus variegatus (Echinodermata: Echinoidea: efeito do ciclo lunar e características da população - doi: 10.4025/actascibiolsci.v33i3.5124 Reproduction of Lytechinus variegatus (Echinodermata: Echinoidea: effect of lunar cycle and population characteristics - doi: 10.4025/actascibiolsci.v33i3.5124

    Directory of Open Access Journals (Sweden)

    Levy de Carvalho Gomes

    2011-07-01

    Full Text Available Este estudo avaliou as características reprodutivas de uma população do ouriço do mar Lytechinus variegatus e a influência do ciclo lunar na liberação de gametas. Foram realizadas oito coletas para avaliação do índice gonadossomático (IG e dos parâmetros populacionais relacionados com a reprodução. Para avaliação do efeito da Lua na liberação de gametas foram realizadas coletas em três ciclos lunares completos. Ao todo foram coletados 295 indivíduos, sendo 156 machos e 131 fêmeas (proporção 1,19:1, porém não houve diferença significativa na proporção sexual da população. O peso dos machos foi significativamente maior que o das fêmeas, porém não houve diferença significativa no IG, peso gonadal e diâmetro entre os sexos. Com a amplitude no diâmetro dos animais coletados (5,5-8,7 cm foram estabelecidas cinco classes de tamanho. Não houve diferenças significativas no IG entre as classes de tamanho. Houve efeito da periodicidade lunar na liberação de gametas, com menor IG na lua nova, indicando que esta ocorre no primeiro quarto lunar e em marés de sizígia.This work evaluated the spawning of sea urchin Lytechinus variegates based on lunar cycle and population characteristics. Eight monthly collections were realized to estimate the gonadosomatic index (GI and population parameters regarding reproduction. To evaluate the effect of the lunar cycle on spawning, samples were taken for each moon phase of three lunar cycles. In the entire work 295 individuals were collected, 156 males and 131 females (1.19:1 ratio. However, there was no significant difference in the sex ratio of the population. The weight of males was significantly greater than that of females. There were no differences between males and females in gonadosomatic index (GI, gonad weight and diameter. There was an effect of the lunar periodicity on spawning, with lower GI in new moon, indicating that spawning occurs on the first lunar quarter in

  11. Analysis of repeated measures data

    CERN Document Server

    Islam, M Ataharul

    2017-01-01

    This book presents a broad range of statistical techniques to address emerging needs in the field of repeated measures. It also provides a comprehensive overview of extensions of generalized linear models for the bivariate exponential family of distributions, which represent a new development in analysing repeated measures data. The demand for statistical models for correlated outcomes has grown rapidly recently, mainly due to presence of two types of underlying associations: associations between outcomes, and associations between explanatory variables and outcomes. The book systematically addresses key problems arising in the modelling of repeated measures data, bearing in mind those factors that play a major role in estimating the underlying relationships between covariates and outcome variables for correlated outcome data. In addition, it presents new approaches to addressing current challenges in the field of repeated measures and models based on conditional and joint probabilities. Markov models of first...

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

    Science.gov (United States)

    Lorbiecke, Rene

    2012-01-01

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

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

    Science.gov (United States)

    Lorbiecke, Rene

    2012-01-01

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

  14. Ciclo gametogênico e comportamento reprodutivo de Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae no estuário do rio Subaé, Baía de Todos os Santos, Bahia, Brasil Gametogenic cycle and reproductive behavior of Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae in the Subaé river estuary, Todos os Santos Bay, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia P. Silva

    2012-12-01

    ém, no mês de outubro de 2002.This study aimed to describe the gametogenic cycle and reproductive behavior of the population of Iphigenia brasiliana (Lamarck, 1818 in the estuary of the Subaé river, Todos os Santos Bay, Bahia. The bivalves were collected from November 2001 to November 2002. A total of 244 specimens was measured (anteroposterior axis, gutted, fixed, dehydrated and embedded in paraffin. The histology of the gonads was performed by 5 mm thick serial sections of gonadal tissue, and stained with HE. The length at the beginning of gonadal maturation (Lpm was estimated from the distribution of the relative frequencies of youth and adults, by length class of individuals. The relative frequencies of the sexes at each stage of development were considered together for the analysis of the reproductive behavior of the population, and, separately, to assess the sexual cycle synchrony between males and females. We observed a variation of sizes between 9.1 and 66.6 mm, with a mean length of 50.2 mm. The study showed no significant difference between the sizes of males and females. There was no evidence of gender differentiation in 2.1% of subjects analyzed. 51.6% of subjects were identified as males (M and 46.3% as females (F, without significant differences among average number of male and female, resulting in the proportion of M:F ratio of 1,1:1. Lpm was estimated at 11.4 mm, but only to achieve average length of 34.4 mm, all subjects were considered adults. We characterized four stages of evolution of gonadal development in females and males. Analysis of different stages allowed the observation of the atresia phenomena and sex reversal in females. The reproductive cycle presents continuous elimination of gametes, with higher reproductive intensities in the months of November 2001 to April 2002 and also in October 2002.

  15. International Committee for Monitoring Assisted Reproductive Technologies world report: Assisted Reproductive Technology 2008, 2009 and 2010.

    Science.gov (United States)

    Dyer, S; Chambers, G M; de Mouzon, J; Nygren, K G; Zegers-Hochschild, F; Mansour, R; Ishihara, O; Banker, M; Adamson, G D

    2016-07-01

    What were utilization, outcomes and practices in assisted reproductive technology (ART) globally in 2008, 2009 and 2010? Global utilization and effectiveness remained relatively constant despite marked variations among countries, while the rate of single and frozen embryo transfers (FETs) increased with a concomitant slight reduction in multiple birth rates. ART is widely practised in all regions of the world. Monitoring utilization, an approximation of availability and access, as well as effectiveness and safety is an important component of universal access to reproductive health. This is a retrospective, cross-sectional survey on utilization, effectiveness and safety of ART procedures performed globally from 2008 to 2010. Between 58 and 61 countries submitted data from a total of nearly 2500 ART clinics each year. Aggregate country data were processed and analyzed based on forms and methods developed by the International Committee for Monitoring Assisted Reproductive Technologies (ICMART). Results are presented at country, regional and global level. For the years 2008, 2009 and 2010, >4 461 309 ART cycles were initiated, resulting in an estimated 1 144 858 babies born. The number of aspirations increased by 6.4% between 2008 and 2010, while FET cycles increased by 27.6%. Globally, ART utilization remained relatively constant at 436 cycles/million in 2008 and 474 cycles/million population in 2010, but with a wide country range of 8-4775 cycles/million population. ICSI remained constant at around 66% of non-donor aspiration cycles. The IVF/ICSI combined delivery rate (DR) per fresh aspiration was 19.8% in 2008; 19.7% in 2009 and 20.0% in 2010, with corresponding DRs for FET of 18.8, 19.7 and 20.7%. In fresh non-donor cycles, single embryo transfer increased from 25.7% in 2008 to 30.0% in 2010, while the average number of embryos transferred fell from 2.1 to 1.9, again with wide regional variation. The rates of twin deliveries following fresh non-donor transfers

  16. Unisexual reproduction enhances fungal competitiveness by promoting habitat exploration via hyphal growth and sporulation.

    Science.gov (United States)

    Phadke, Sujal S; Feretzaki, Marianna; Heitman, Joseph

    2013-08-01

    Unisexual reproduction is a novel homothallic sexual cycle recently discovered in both ascomycetous and basidiomycetous pathogenic fungi. It is a form of selfing that induces the yeast-to-hyphal dimorphic transition in isolates of the α mating type of the human fungal pathogen Cryptococcus neoformans. Unisexual reproduction may benefit the pathogen by facilitating sexual reproduction in the absence of the opposite a mating type and by generating infectious propagules called basidiospores. Here, we report an independent potential selective advantage of unisexual reproduction beyond genetic exchange and recombination. We competed a wild-type strain capable of undergoing unisexual reproduction with mutants defective in this developmental pathway and found that unisexual reproduction provides a considerable dispersal advantage through hyphal growth and sporulation. Our results show that unisexual reproduction may serve to facilitate access to both nutrients and potential mating partners and may provide a means to maintain the capacity for dimorphic transitions in the environment.

  17. The More the Merrier?. Entropy and Statistics of Asexual Reproduction in Freshwater Planarians

    Science.gov (United States)

    Quinodoz, Sofia; Thomas, Michael A.; Dunkel, Jörn; Schötz, Eva-Maria

    2011-04-01

    The trade-off between traits in life-history strategies has been widely studied for sexual and parthenogenetic organisms, but relatively little is known about the reproduction strategies of asexual animals. Here, we investigate clonal reproduction in the freshwater planarian Schmidtea mediterranea, an important model organism for regeneration and stem cell research. We find that these flatworms adopt a randomized reproduction strategy that comprises both asymmetric binary fission and fragmentation (generation of multiple offspring during a reproduction cycle). Fragmentation in planarians has primarily been regarded as an abnormal behavior in the past; using a large-scale experimental approach, we now show that about one third of the reproduction events in S. mediterranea are fragmentations, implying that fragmentation is part of their normal reproductive behavior. Our analysis further suggests that certain characteristic aspects of the reproduction statistics can be explained in terms of a maximum relative entropy principle.

  18. Fern Gametophytes in Culture--A Simple System for Studying Plant Development and Reproduction.

    Science.gov (United States)

    Dyer, A. F.

    1983-01-01

    Discusses fern life cycle and basic techniques for culturing fern gametophytes in the classroom. Also discusses investigations into the reproductive biology of ferns and into the early development of gametophytes. (JN)

  19. Ethics of Reproductive Engineering

    Science.gov (United States)

    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…

  20. Sound reproduction system

    NARCIS (Netherlands)

    Boone, M.M.; De Vries, D.; Horbach, U.

    2002-01-01

    Arrangement of a sound reproduction system (1), including at least one input (2), a sound field generator (4), a loudspeaker panel (10); the at least one input (2) connected to the sound filed generator (4), and the sound filed (4) connected to the loudspeaker panel (10); the at least one input (2)

  1. Preparing for Assisted Reproductive Technology

    Science.gov (United States)

    ... 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 ...

  2. Fes cycling

    Directory of Open Access Journals (Sweden)

    Berkelmans Rik

    2008-01-01

    Full Text Available Many research with functional electrical stimulation (FES has been done to regain mobility and for health benefits. Better results have been reported for FES-cycling than for FES-walking. The majority of the subjects during such research are people with a spinal cord injury (SCI, cause they often lost skin sensation. Besides using surface stimulation also implanted stimulators can be used. This solves the skin sensation problem, but needs a surgery. Many physiological effects of FES-cycling has been reported, e.g., increase of muscles, better blood flow, reduction of pressure ulcers, improved self-image and some reduction of bone mineral density (BMD loss. Also people with an incomplete SCI benefit by FES-cycling, e.g. cycling time without FES, muscle strength and also the walking abilities increased. Hybrid exercise gives an even better cardiovascular training. Presently 4 companies are involved in FES-cycling. They all have a stationary mobility trainer. Two of them also use an outdoor tricycle. One combined with voluntary arm cranking. By optimizing the stimulation parameters the power output and fatigue resistance will increase, but will still be less compared to voluntary cycling.

  3. Using the Reproductive Life Plan in contraceptive counselling

    Science.gov (United States)

    Verbiest, Sarah; Van Achterberg, Theo; Larsson, Margareta; Stern, Jenny

    2016-01-01

    Having children or not is one of the most important decisions that a person will make in his or her lifetime. The Reproductive Life Plan (RLP) is a protocol that aims to encourage both women and men to reflect on their reproductive intentions and to find strategies for successful family planning, for example to have the wanted number of children and to avoid unwanted pregnancies as well as ill-health that may threaten reproduction. The RLP was developed in an American context for promotion of reproductive health in a life cycle perspective. Few studies have systematically evaluated the effectiveness of using an RLP protocol in clinical practice. This article describes the application of using the RLP protocol in contraceptive counselling in Sweden. PMID:27646817

  4. Nectar amino acids enhance reproduction in male butterflies.

    Science.gov (United States)

    Cahenzli, Fabian; Erhardt, Andreas

    2013-01-01

    After over 30 years of research, it was recently shown that nectar amino acids increase female butterfly fecundity. However, little attention has been paid to the effect of nectar amino acids on male butterfly reproduction. Here, we show that larval food conditions (nitrogen-rich vs. nitrogen-poor host plants) and adult diet quality (nectar with or without amino acids) affected the amount of consumed nectar in Coenonympha pamphilus males. Furthermore, amino acids in the nectar diet of males increased progeny's larval hatching mass, irrespective of paternal larval reserves. Our study takes the whole reproductive cycle of male butterflies into account, and also considers the role of females in passing male nutrients to offspring, as males' realized reproduction was examined indirectly via nuptial gifts, by female performance. With this comprehensive approach, we demonstrate for the first time that nectar amino acids can improve male butterfly reproduction, supporting the old postulate that nectar amino acids generally enhance butterfly fitness.

  5. Using the Reproductive Life Plan in contraceptive counselling.

    Science.gov (United States)

    Tydén, Tanja; Verbiest, Sarah; Van Achterberg, Theo; Larsson, Margareta; Stern, Jenny

    2016-09-20

    Having children or not is one of the most important decisions that a person will make in his or her lifetime. The Reproductive Life Plan (RLP) is a protocol that aims to encourage both women and men to reflect on their reproductive intentions and to find strategies for successful family planning, for example to have the wanted number of children and to avoid unwanted pregnancies as well as ill-health that may threaten reproduction. The RLP was developed in an American context for promotion of reproductive health in a life cycle perspective. Few studies have systematically evaluated the effectiveness of using an RLP protocol in clinical practice. This article describes the application of using the RLP protocol in contraceptive counselling in Sweden.

  6. Basic and applied aspects of female reproduction in farmed ostriches

    NARCIS (Netherlands)

    Bronneberg, R.G.G.

    2008-01-01

    This thesis investigated basic and applied aspects of female reproduction in farmed ostriches throughout the 48h egg laying cycle, during the egg production season, and, the non-breeding season. The main objectives were: (1) to evaluate the use of transcutaneous ultrasound scanning to visualize func

  7. Reproduction rate as a factor in meat production

    African Journals Online (AJOL)

    The need to optimize rather than maximize rates of reproduction has been ..... The prin- cipal component of this management is believed to be the .... milk production were most efficient in retail product/ME. Contrary ... period. Returning finally to the concept of genotype-environmental ... Life cycle efficiency of beef production:.

  8. Methods for sequencing GC-rich and CCT repeat DNA templates

    Science.gov (United States)

    Robinson, Donna L.

    2007-02-20

    The present invention is directed to a PCR-based method of cycle sequencing DNA and other polynucleotide sequences having high CG content and regions of high GC content, and includes for example DNA strands with a high Cytosine and/or Guanosine content and repeated motifs such as CCT repeats.

  9. Effects of repeated exposure to high static magnetic fields during NMR imaging on the end point of reproduction and development in the animal model; Auswirkungen wiederholter Exposition mit starken statischen Magnetfeldern des MRI auf die Endpunkte Fortpflanzung und Entwicklung im Tiermodell

    Energy Technology Data Exchange (ETDEWEB)

    Winterhager, E.; Gruemmer, R.; Ladd, M.E.

    2011-12-15

    In the present study, the effects of repeated exposure to strong static magnetic fields up to a flux density of 7 Tesla on spermatogenesis in adult male mice as well as on pregnancy and embryogenesis in female mice were studied. In addition, the fertility of male and female mice which were exposed daily to these static magnetic fields throughout their entire embryonic development in utero was investigated. Six experimental groups were examined: (1) cage controls, (2) sham-exposed controls, (3) exposure at the bore entrance and (4) in the isocenter of a 1.5T MRI, (5) exposure at the bore entrance and (6) in the isocenter of a 7T MRI. Overall, 895 adult mice, 944 offspring, and 2007 embryos were analyzed in this study.

  10. New insights into placozoan sexual reproduction and development.

    Directory of Open Access Journals (Sweden)

    Michael Eitel

    Full Text Available Unraveling animal life cycles and embryonic development is basic to understanding animal biology and often sheds light on phylogenetic relationships. A key group for understanding the evolution of the Metazoa is the early branching phylum Placozoa, which has attracted rapidly increasing attention. Despite over a hundred years of placozoan research the life cycle of this enigmatic phylum remains unknown. Placozoa are a unique model system for which the nuclear genome was published before the basic biology (i.e. life cycle and development has been unraveled. Four organismal studies have reported the development of oocytes and one genetic study has nourished the hypothesis of sexual reproduction in natural populations at least in the past. Here we report new observations on sexual reproduction and embryonic development in the Placozoa and support the hypothesis of current sexual reproduction. The regular observation of oocytes and expressed sperm markers provide support that placozoans reproduce sexually in the field. Using whole genome and EST sequences and additional cDNA cloning we identified five conserved sperm markers, characteristic for different stages in spermatogenesis. We also report details on the embryonic development up to a 128-cell stage and new ultrastructural features occurring during early development. These results suggest that sperm and oocyte generation and maturation occur in different placozoans and that clonal lineages reproduce bisexually in addition to the standard mode of vegetative reproduction. The sum of observations is best congruent with the hypothesis of a simple life cycle with an alternation of reproductive modes between bisexual and vegetative reproduction.

  11. Reproductive rights approach to reproductive health in developing countries

    Directory of Open Access Journals (Sweden)

    Vijayan K. Pillai

    2011-12-01

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

  12. Sexual Satellites, Moonlight and the Nuptial Dances of Worms: the Influence of the Moon on the Reproduction of Marine Animals

    Science.gov (United States)

    Bentley, M. G.; Olive, P. J. W.; Last, K.

    The evidence that the moon has a profound effect on the timing of reproductive activities of marine animals is compelling. Some moon phase related spawning events are revealed by the constant phase relationship between the timing of ``once per year'' spawning events and the lunar phase as in the highly synchronised breeding of the palolo worm Palola viridis and the Japanese crinoid Comanthus japonicus In other cases there is a repeated lunar cycle of reproductive activity and again the marine worms provide many good examples. The breeding of the palolo worm involves the highly synchronised release of what are in effect detached sexual satellites and the timing of this has annual (solar year), lunar, daily and tidal rhythm components. In a similar way, the onset of sexual maturation and participation in the nuptial dance of Platynereis dumerilli has strong lunar components. Sexual reproduction is the culmination of a process of sexual maturation that takes many months for completion and the mechanisms by which moon phase relationships are imposed on this process must have been selected for by mechanisms relating to reproductive success. The polychaetes provide excellent models for investigation of both the selective advantage and the physiological processes involved in reproductive synchrony. We have recently shown that the spawning of the lugworm Arenicola marina has lunar components and we conclude that an interaction between solar and lunar signals is widespread in the timing of reproduction in marine animals. Carl Hauenschild was the first to demonstrate the existence of a free-running circa-lunar rhythm in marine animals using captive populations of Platynereis dumerilli His experiments also provided clear evidence for the influence of moonlight (light at night) as the zeitgeber for this rhythm. This implies a high level of sensitivity to light, and the operation of appropriate endogenous biological rhythms. Using Nereis virens we have demonstrated a high level

  13. Limitations on quantum key repeaters.

    Science.gov (United States)

    Bäuml, Stefan; Christandl, Matthias; Horodecki, Karol; Winter, Andreas

    2015-04-23

    A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution. Owing to noise in the communication line, quantum key distribution is, in practice, limited to a distance of a few hundred kilometres, and can only be extended to longer distances by use of a quantum repeater, a device that performs entanglement distillation and quantum teleportation. The existence of noisy entangled states that are undistillable but nevertheless useful for quantum key distribution raises the question of the feasibility of a quantum key repeater, which would work beyond the limits of entanglement distillation, hence possibly tolerating higher noise levels than existing protocols. Here we exhibit fundamental limits on such a device in the form of bounds on the rate at which it may extract secure key. As a consequence, we give examples of states suitable for quantum key distribution but unsuitable for the most general quantum key repeater protocol.

  14. Considerations on repeated repairing of weldments in Inconel 718 alloy

    Science.gov (United States)

    Bayless, E. O.; Lovoy, C. V.; Mcilwain, M. C.; Munafo, P.

    1981-01-01

    The effects of repeated weld repairs on the metallurgical characteristics, high cycle fatigue (HCF), and tensile properties of Inconel 718 butt weld joints were determined. A 1/4 in thick plate and a 1/2 in thick plate were used as well as tungsten inert gas welding, and Inconel 718 filler wire. Weld panels were subjected to 2, 6, and 12 repeated repairs and were made in a highly restrained condition. Post weld heat treatments were also conducted with the welded panel in the highly restrained condition. Results indicate that no significant metallurgical anomaly is evident as a result of up to twelve repeated weld repairs. No degradation in fatigue life is noted for up to twelve repeated repairs. Tensile results from specimens which contained up to twelve repeated weld repairs revealed no significant degradation in UTS and YS. However, a significant decrease in elongation is evident with specimens (solution treated and age hardened after welding) which contained twelve repeated repairs. The elongation loss is attributed to the presence of a severe notch on each side (fusion line) of the repair weld bead reinforcement.

  15. Glacial cycles

    DEFF Research Database (Denmark)

    Kaufmann, R. K.; Juselius, Katarina

    We use a statistical model, the cointegrated vector autoregressive model, to assess the degree to which variations in Earth's orbit and endogenous climate dynamics can be used to simulate glacial cycles during the late Quaternary (390 kyr-present). To do so, we estimate models of varying complexity...... and compare the accuracy of their in-sample simulations. Results indicate that strong statistical associations between endogenous climate variables are not enough for statistical models to reproduce glacial cycles. Rather, changes in solar insolation associated with changes in Earth's orbit are needed...

  16. Response of two prairie forbs to repeated vole herbivory.

    Science.gov (United States)

    Sullivan, Amy T; Howe, Henry F

    2011-04-01

    Vertebrate herbivores as diverse as ungulates, geese, and rabbits preferentially feed on plants that have previously experienced herbivory. Here, we ask whether smaller grassland "cryptic consumers" such as voles (Microtus ochrogaster and M. pennsylvanicus) preferentially clip (cut stems for access to leaves or seeds) or avoid previously clipped individuals of two tallgrass prairie species (Desmanthus illinoensis and Echinacea purpurea) within a growing season. Further, we ask how these plants respond to repeated clipping within a growing season, and whether the effects of this herbivory last into the subsequent growing season. Voles preferentially clipped stems of D. illinoensis and E. purpurea plants that had been previously clipped. The exception was indiscriminant clipping of stems of E. purpurea late in the growing season when its achenes, a favorite vole food, ripened. For D. illinoensis, repeated clipping resulted in a 59% reduction in biomass, 42% lower ratio of reproductive to vegetative biomass, and 57% fewer seeds produced per plant compared with unclipped plants. These effects lasted into the following growing season in which plants were protected from voles. In contrast, the only effect of repeated clipping for E. purpurea was that the number of achenes per plant was substantially reduced by three episodes of clipping. This effect did not carry over to the next growing season. Such differences in D. illinoensis and E. purpurea response to repeated stem clipping by voles offer insights into how these small rodents can effect major changes in composition and dominance in grassland communities.

  17. Happy Cycling

    DEFF Research Database (Denmark)

    Geert Jensen, Birgitte; Nielsen, Tom

    2013-01-01

    og Interaktions Design, Aarhus Universitet under opgave teamet: ”Happy Cycling City – Aarhus”. Udfordringen i studieopgaven var at vise nye attraktive løsningsmuligheder i forhold til cyklens og cyklismens integration i byrum samt at påpege relationen mellem design og overordnede diskussioner af...

  18. Glacial cycles

    DEFF Research Database (Denmark)

    Kaufmann, R. K.; Juselius, Katarina

    and compare the accuracy of their in-sample simulations. Results indicate that strong statistical associations between endogenous climate variables are not enough for statistical models to reproduce glacial cycles. Rather, changes in solar insolation associated with changes in Earth's orbit are needed...

  19. Koszul cycles

    CERN Document Server

    Bruns, Winfreid; Römer, Tim

    2010-01-01

    We prove regularity bounds for Koszul cycles holding for every ideal of dimension at most 1 in a polynomial ring. We generalize the lower bound for the Green-Lazarsfeld index of Veronese rings we proved in arXiv:0902.2431 to the multihomogeneous setting.

  20. Reproductive biology of Thamnodynastes hypoconia (Serpentes: Dipsadidae in Brazilian subtemperate wetlands

    Directory of Open Access Journals (Sweden)

    MARLUCI M. REBELATO

    2016-01-01

    Full Text Available ABSTRACT This study aimed to describe the reproductive biology of populations of Thamnodynastes hypoconia in subtemperate wetlands based on macroscopic analyses of their gonads. We analyzed 101 specimens from the southernmost regions of Brazil. The males had a greater snout-vent length, but the females reached sexual maturity with a greater body size. The reproductive cycle of the females was seasonal, with secondary vitellogenesis occurring between the winter and spring (May-October. Based on macroscopic analysis of gonads, data suggests that males have a continuous reproductive cycle. Parturition occurs between the late summer and early fall (January-April. The clutch size ranged between 4 and 16 embryos and showed no relationship with the female's body size. The recorded reproductive frequency of T. hypoconia is low (38 % compared to other phylogenetically related species. Conversely, the studied populations appear to have a high reproductive success because it is an abundant species in the study site.

  1. New biotechnological procedures in swine reproduction

    Directory of Open Access Journals (Sweden)

    Petrujkić Tihomir

    2002-01-01

    Full Text Available New biotechnological procedures and the use of hormones in swine breeding are aimed at increasing the number of piglets in the litter. In small herds and groups, selected sows with 16 mammary complexes (tits can yield up to 32 piglets, or porkers, per year per sow. In order to achieve such reproduction results, special, individual stalls for sow deliveries are used, in addition to biotechnological methods, with a warm core and floor heating, phased diet and clean facilities. The ovulation value in swine is determined by their genetic and paragenetic effects, and it is often provoked and increased with injections and preparations for superovulation. However, the results vary, since any administration of hormone injecions can reduce the reproductive cycle, shorten the duration of estrus, or disrupt the work of ovaries and create cystic follicles. The use of follicle-stimulating hormones in quantities up to 1000 IU per animal for the induction and synchronization of estrus has become customary for sows and gilts, as well as the use of prostaglandins, the use of GnRH for increasing ovulation in swine and increasing the number of follicles >4 mm in diameter in the implementation of new biotechnologies in swine breeding, increases the number of ovulations and fertility in swine. In this way, reproduction is raised to the highest possible level, and artificial insemination of sows has 12 separate rules which enable better and more successful artificial insemination of sows.

  2. EAMJ Dec. Repeatability.indd

    African Journals Online (AJOL)

    2008-12-12

    Dec 12, 2008 ... Results:Kappa values for four-week repeatability for the wheeze and asthma questions were 0.61 ... for logistic, cultural and ethical reasons, to use ... individual with baseline forced expiratory volume in .... period is likely to also include the effects of true ... data, the writing of the manuscript or the decision.

  3. Assessing reproductive behavior important to fisheries management: a case study with red drum, Sciaenops ocellatus.

    Science.gov (United States)

    Lowerre-barbieri, Susan K; Burnsed, Sarah L Walters; Bickford, Joel W

    2016-06-01

    Spawning site selection and reproductive timing affect stock productivity and structure in marine fishes but are poorly understood. Traditionally, stock assessments measure reproductive potential as spawning stock biomass or egg production and do not include other aspects of reproductive behavior. Red drum make an excellent case study to assess these other aspects, as (1) they are highly fecund, pelagic spawners, like most exploited marine fishes; (2) their life cycle is delineated between nursery (estuarine) and adult (coastal and offshore) habitat; and (3) they are managed at these two spatial scales. This study was conducted from August 2012 to December 2013 and integrates data from multiple methods and spatial scales. Aerial surveys were used for large-scale monitoring of aggregations off two known estuarine nursery areas, Tampa Bay and Charlotte Harbor, Florida, USA. Capture-based sampling in Tampa Bay coastal (n = 2581) and estuarine waters (n = 158) was used to assess reproductive state and to confirm coastal spawning. To assess spatial dynamics, we acoustically tagged two population components in the Tampa Bay system, subadults from the estuary (n = 20) and adults from the coastal spawning site (n = 60). Behavioral plasticity was seen in subadult recruitment to coastal habitat, with some subadults maturing and recruiting before or during the spawning season and others (14 of 20 acoustically tagged fish) recruiting at the end of the 2012 spawning season. Both adults and recruited subadults (n = 29) were consequently detected in the Charlotte Harbor array, 132 km to the south. Spawning-site fidelity to the Tampa Bay spawning site occurred at both the population and individual scales. Aggregations consistently occurred in Tampa Bay coastal waters during the spawning season, and approximately two-thirds of tagged adults returned in the 2013 spawning season. A similar proportion of subadults returned to the Tampa Bay spawning site, exhibiting natal homing

  4. Effects of repeated use and resterilization on structural and functional integrity of microwave ablation antennas.

    Science.gov (United States)

    Finck, Cyrielle A; Zur Linden, Alex R; Singh, Ameet; Foster, Robert A; Nykamp, Stephanie G; Sears, William C

    2017-04-01

    OBJECTIVE To determine effects of repeated use and resterilization on structural and functional integrity of microwave ablation (MWA) antennas. SAMPLE 17 cooled-shaft MWA antennas (3 groups of 5 antennas/group and 2 control antennas). PROCEDURES 1, 2, and 3 ablations in the livers of bovine cadavers were performed at the maximum recommended settings. Antennas were cleaned and sterilized in hydrogen peroxide plasma, and the process was repeated (reprocessing cycle; n = 6). Control antennas were only sterilized (6 times). Aerobic and anaerobic bacterial cultures were performed, and antennas were microscopically assessed for damage. RESULTS 6 cycles were completed. Thirteen of 15 MWA antennas remained functional for up to 4 cycles, 10 were functional after 5 cycles, and only 7 were functional after 6 cycles. Progressive tearing of the silicone coating of the antennas was observed, with a negative effect of the number of cycles for silicone tearing. Size of the ablation zone decreased mildly over time after cycles 5 and 6; however, this was not considered clinically relevant. No significant changes in the shape of ablation zones were detected. All cultures yielded negative results, except for an isolated case, which was considered a contaminant. CONCLUSIONS AND CLINICAL RELEVANCE Structural and functional integrity of the microwave antennas remained acceptable during repeated use and reprocessing for up to 4 cycles. However, there was a decrease in functional integrity at cycles 5 and 6. We suggest that these microwave antennas be subjected to > 3 reprocessing cycles. Antennas should be carefully examined before reuse.

  5. Incidence of gross reproductive abnormalities in small east African zebu cattle.

    Science.gov (United States)

    Assey, R J; Kessy, B M; Matovelo, J A; Minga, U

    1998-12-01

    Reproductive organs from mature Small East African zebu (SEAZ) heifers and cows slaughtered at the Morogoro abattoir were collected twice a month and evaluated over a period of 12 months. Out of the 402 animals from which reproductive organs were taken, 54% were pregnant, 24% were actively cycling and 22% were non-cycling. Various gross abnormalities were observed in the reproductive organs of about 16% of the cattle, and the major reproductive abnormality in both total and the non-cycling animals was various degrees of fibrous adhesion between the ovary and the infundibulum and mesosalpinx. It is concluded that, contrary to common belief, a majority of the female SEAZ cattle that are slaughtered are fertile.

  6. Reproductive biology of Echinanthera cyanopleura (Serpentes: Dipsadidae in southern Brazil

    Directory of Open Access Journals (Sweden)

    Noeli Zanella

    2010-02-01

    Full Text Available The reproductive cycles of snakes can be influenced by many factors, both biotic and abiotic, and information about these factors can contribute significantly to knowledge of the biology of many species. Here, we present data on the reproductive biology (body size, sexual dimorphism and female reproductive cycle of the forest-dwelling colubrid Echinanthera cyanopleura (Cope, 1885, based on analyses of 128 specimens preserved in collections and originating from the states of Paraná, Santa Catarina, and Rio Grande do Sul in southern Brazil. The snout-vent length of females was significantly greater than in males. The tail length of mature females was greater than in males, although this difference was not significant. Vitellogenesis occurs from August to December and eggs were found in greater frequency from October through December. Juveniles were found in larger numbers beginning in February, indicating that recruitment occurs from January to April. The reproductive cycle of this species is seasonal, which is usual for oviparous colubrids of temperate areas of Brazil.

  7. Repeated adaptive divergence of microhabitat specialization in avian feather lice

    Directory of Open Access Journals (Sweden)

    Johnson Kevin P

    2012-06-01

    Full Text Available Abstract Background Repeated adaptive radiations are evident when phenotypic divergence occurs within lineages, but this divergence into different forms is convergent when compared across lineages. Classic examples of such repeated adaptive divergence occur in island (for example, Caribbean Anolis lizards and lake systems (for example, African cichlids. Host-parasite systems in many respects are analogous to island systems, where host species represent isolated islands for parasites whose life cycle is highly tied to that of their hosts. Thus, host-parasite systems might exhibit interesting cases of repeated adaptive divergence as seen in island and lake systems. The feather lice of birds spend their entire life cycle on the body of the host and occupy distinct microhabitats on the host: head, wing, body and generalist. These microhabitat specialists show pronounced morphological differences corresponding to how they escape from host preening. We tested whether these different microhabitat specialists were a case of repeated adaptive divergence by constructing both morphological and molecular phylogenies for a diversity of avian feather lice, including many examples of head, wing, body and generalist forms. Results Morphological and molecular based phylogenies were highly incongruent, which could be explained by rampant convergence in morphology related to microhabitat specialization on the host. In many cases lice from different microhabitat specializations, but from the same group of birds, were sister taxa. Conclusions This pattern indicates a process of repeated adaptive divergence of these parasites within host group, but convergence when comparing parasites across host groups. These results suggest that host-parasite systems might be another case in which repeated adaptive radiations could be relatively common, but potentially overlooked, because morphological convergence can obscure evolutionary relationships.

  8. A method for the incremental expansion of polyglutamine repeats in recombinant proteins.

    Science.gov (United States)

    Robertson, Amy L; Bottomley, Stephen P

    2013-01-01

    The polyglutamine diseases are caused by the expansion of CAG repeats. A key step in understanding the disease mechanisms, at the DNA and protein level, is the ability to produce recombinant proteins with specific length glutamine tracts which is a time-consuming first step in setting up in vitro systems to study the effects of polyglutamine expansion. Described here is a PCR-based method for the amplification of CAG repeats, which we used to incrementally extend CAG length by 3-5 repeats per cycle. This method could be translated into various contexts where amplification of repeating elements is necessary.

  9. Androgen receptor gene CAG repeat length as modifier of the association between Persistent Organohalogen Pollutant exposure markers and semen characteristics

    DEFF Research Database (Denmark)

    Giwercman, Aleksander; Rylander, Lars; Rignell-Hydbom, Anna;

    2007-01-01

    OBJECTIVES: Exposure to persistent organohalogen pollutants was suggested to impair male reproductive function. A gene-environment interaction has been proposed. No genes modifying the effect of persistent organohalogen pollutants on reproductive organs have yet been identified. We aimed...... and morphology) and DNA fragmentation index (DFI) were determined. CAG and GGN repeat lengths were determined by direct sequencing of leukocyte DNA. RESULTS: A statistically significant interaction was found between the CB-153 group and CAG repeat category in relation to sperm concentration and total sperm count...

  10. Effect of electromagnetic field exposure on the reproductive system.

    Science.gov (United States)

    Gye, Myung Chan; Park, Chan Jin

    2012-03-01

    The safety of human exposure to an ever-increasing number and diversity of electromagnetic field (EMF) sources both at work and at home has become a public health issue. To date, many in vivo and in vitro studies have revealed that EMF exposure can alter cellular homeostasis, endocrine function, reproductive function, and fetal development in animal systems. Reproductive parameters reported to be altered by EMF exposure include male germ cell death, the estrous cycle, reproductive endocrine hormones, reproductive organ weights, sperm motility, early embryonic development, and pregnancy success. At the cellular level, an increase in free radicals and [Ca(2+)]i may mediate the effect of EMFs and lead to cell growth inhibition, protein misfolding, and DNA breaks. The effect of EMF exposure on reproductive function differs according to frequency and wave, strength (energy), and duration of exposure. In the present review, the effects of EMFs on reproductive function are summarized according to the types of EMF, wave type, strength, and duration of exposure at cellular and organism levels.

  11. Sperm competition drives the evolution of suicidal reproduction in mammals.

    Science.gov (United States)

    Fisher, Diana O; Dickman, Christopher R; Jones, Menna E; Blomberg, Simon P

    2013-10-29

    Suicidal reproduction (semelparity) has evolved in only four genera of mammals. In these insectivorous marsupials, all males die after mating, when failure of the corticosteroid feedback mechanism elevates stress hormone levels during the mating season and causes lethal immune system collapse (die-off). We quantitatively test and resolve the evolutionary causes of this surprising and extreme life history strategy. We show that as marsupial predators in Australia, South America, and Papua New Guinea diversified into higher latitudes, seasonal predictability in abundance of their arthropod prey increased in multiple habitats. More-predictable prey peaks were associated with shorter annual breeding seasons, consistent with the suggestion that females accrue fitness benefits by timing peak energy demands of reproduction to coincide with maximum food abundance. We demonstrate that short mating seasons intensified reproductive competition between males, increasing male energy investment in copulations and reducing male postmating survival. However, predictability of annual prey cycles alone does not explain suicidal reproduction, because unlike insect abundance, peak ovulation dates in semelparous species are often synchronized to the day among years, triggered by a species-specific rate of change of photoperiod. Among species with low postmating male survival, we show that those with suicidal reproduction have shorter mating seasons and larger testes relative to body size. This indicates that lethal effort is adaptive in males because females escalate sperm competition by further shortening and synchronizing the annual mating period and mating promiscuously. We conclude that precopulatory sexual selection by females favored the evolution of suicidal reproduction in mammals.

  12. Reproductive Biology of Bothrops erythromelas from the Brazilian Caatinga

    Directory of Open Access Journals (Sweden)

    Verônica Alberto Barros

    2014-01-01

    Full Text Available The reproductive biology of Bothrops erythromelas, a small pit viper from the Caatinga, a semiarid biome in Brazil, is described based on analysis of individuals deposited in zoological collections. Males are smaller and also attain sexual maturity at a smaller size than females. Female reproductive cycle is seasonal with an extended period of secondary vitellogenesis and births occurring in a restricted period from late spring to early summer. Sperm storage in females may probably occur in infundibular tubular glands and uterine muscular twisting (UMT, which is a polymorphic condition within B. erythromelas. Seasonal spermatogenesis in males is variable with some intraspecific variation regarding the male reproductive stage per season. Most males are reproductively active during spring/summer and reproductively quiescent during autumn/winter, although some individuals vary (e.g., show testicular spermatogenesis and active sexual segment of the kidneys (SSK during winter. The SSK could be identified in every male. Most males showed highly hypertrophied SSK in spring/summer and moderately hypertrophied SSK in autumn/winter. The ampulla ductus deferentis was observed and histochemical reactions were conducted. We discuss the probable influence of the unique environmental conditions of the Caatinga region and phylogenetic inertia in the reproductive patterns of this snake species.

  13. Reproductive and early life stages pathology - Histopathology workshop report

    Science.gov (United States)

    Bruno, D.W.; Nowak, B.; Elliott, D.G.

    2006-01-01

    Pathology occurring during reproduction and larval development represents an important part of the life cycle of fish, and the diseases that affect eggs and larvae often result in significant losses. However, mortality during this period is frequently ignored or poorly researched as the temptation is to replace the losses rather than investigate the causes. A histopathology workshop organised at the newly refurnished laboratory within the Danish Veterinary School was an opportunity to discuss the pathology of selected diseases associated with Reproductive and Early Life Stages Pathology. Several people also kindly provided reference slides.

  14. Sulfur cycle

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.

    :1, the reductive assimilation of sulfate is less important than nitrate. Assimilatory reduction is common among organisms and does not lead to the production of sulfide. The eight-electron reduction of sulfate to sulfide pro- ceeds in different stages. As the ion...; Biogeochemical Approaches to Environmental Risk Assessment; Biogeochemical Models; Biomagnification; Carbon Cycle; Classification and Regression Trees; Climate Change 1: Short-Term Dynamics; Constructed Wetlands, Subsurface Flow; Constructed Wetlands, Surface...

  15. VARIATIONS IN REPRODUCTIVE TOXICANT IDENTIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, F

    2008-05-13

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

  16. Reproductive cycle and population structure of the deep-water shrimp Aristeus antillensis A. Milne Edwards & Bouvier, 1909 (Decapoda: Aristeidae on southeast Brazilian continental slope Ciclo reproductivo y estructura poblacional del camarón de aguas profundas Aristeus antillensis A. Milne Edwards & Bouvier, 1909 (Decapoda: Aristeidae en el talud continental del sureste de Brasil

    Directory of Open Access Journals (Sweden)

    Paulo Ricardo Pezzuto

    2009-01-01

    Full Text Available The "alistado shrimp" (Aristeus antillensis is one of the targets of the trawling fleet operating since 2002 along the continental slope of the Brazilian Economic Exclusive Zone between 700 and 800 m depth. Catches of the species occur mainly in two small fishing grounds located on the east coast of Espirito Santo State (19-22°S. This paper aimed to obtain the first biological data for this species along the Brazilian coast. A total of 13,797 individuals were sampled aboard fishing vessels by observers on almost all fishing hauls, corresponding to 10 to 20% of the total catch recorded in the period. Males and females are sexually mature at 25.4 and 40.2 mm carapace length, respectively, based on an analysis of the proportions of individuals with fused petasma (males and spermatophores in the thelycum (females. The proportion of impregnated females was higher than 80% year round, suggesting a continuous reproductive cycle, although preliminary in-formation on gonadal development points to possible seasonal reproduction. In general, mature females, which attain larger sizes than males, domínate the catches (M:F = 0.12:1. However, populational groups including males and juveniles of both sexes occupy the fishing grounds in different periods of the year, probably reflecting migratory movements whose directions and driving forces are not completely understood yet. A depth-stratified population structure by sex and size is hypothesized.La gamba de aguas profundas Aristeus antillensis es uno de los recursos explotados por la flota de arrastre, que está operando desde el año 2002 en el talud continental de la Zona Econômica Exclusiva de Brasil, entre 700 y 800 m de profundidad. Las capturas de esta especie se realizan básicamente en dos pequeños fondos de pesca que se encuentran en la costa este de la región de Espirito Santo (19-22°S. Este trabajo tiene por objetivo obtener los primeros antecedentes biológicos de esta especie en la costa

  17. Gene editing as applied to prevention of reproductive porcine reproductive and respiratory syndrome.

    Science.gov (United States)

    Whitworth, Kristin M; Prather, Randall S

    2017-04-08

    Porcine Reproductive and Respiratory Syndrome (PRRS) causes severe reproductive failure in sows, as well as transplacental transfer of PRRS virus (PRRSV) to late-gestation fetuses, resulting in abortions, early farrowing, increased number of stillborn piglets, and weak neonatal piglets. PRRSV-infected boars present with anorexia and lethargy, and have decreased sperm quality. The gene for the cellular receptor that the PRRSV uses, Cluster of differentiation 163 (CD163), was edited using Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene-editing technology to create biallelic DNA edits to the CD163 gene in 100% of the offspring. CD163-null pigs challenged with virus were completely resistant to both Type 1 and Type 2 PRRSV isolates, as measured by clinical signs, viremia, antibody response, and lung histopathology. In vitro studies showed that CD163-null alveolar macrophages were also not permissive to infection by a panel of six Type 1 and nine Type 2 viral isolates. Thus, DNA editing of the CD163 gene prevented PRRSV infection and reproductive losses associated with infection. This article is protected by copyright. All rights reserved.

  18. Male reproductive health and yoga

    OpenAIRE

    Pallav Sengupta; Prasenjit Chaudhuri; Koushik Bhattacharya

    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 cel...

  19. Directionality switchable gain stabilized linear repeater

    Science.gov (United States)

    Ota, Takayuki; Ohmachi, Tadashi; Aida, Kazuo

    2004-10-01

    We propose a new approach to realize a bidirectional linear repeater suitable for future optical internet networks and fault location in repeater chain with OTDR. The proposed approach is the linear repeater of simple configuration whose directionality is rearranged dynamically by electrical control signal. The repeater is composed of a magneto-optical switch, a circulator, a dynamically gain stabilized unidirectional EDFA, and control circuits. The repeater directionality is rearranged as fast as 0.1ms by an electrical control pulse. It is experimentally confirmed that OTDR with the directionality switchable repeater is feasible for repeater chain. The detailed design and performance of the repeater are also discussed, including the multi-pass interference (MPI) which may arise in the proposed repeater, the effect of the MPI on SNR degradation of the repeater chain and the feed-forward EDFA gain control circuit.

  20. Repeated use of ion-exchange resin membranes in calcareous soils

    Science.gov (United States)

    Sherrod, S.K.; Belnap, J.; Miller, M.E.

    2003-01-01

    This study compared the consistency of nutrient extraction among repeated cycles of ion-exchange resin membrane use. Two sandy calcareous soils and different equilibration temperatures were tested. No single nutrient retained consistent values from cycle to cycle in all treatments, although both soil source and temperature conferred some influence. It was concluded that the most conservative use of resin membranes is single-use.

  1. Reproductive control in apartheid South Africa.

    Science.gov (United States)

    Kaufman, C E

    2000-03-01

    Since its inception in 1974, the South African family planning programme has been widely believed to be linked with white fears of growing black numbers. The programme has been repeatedly attacked by detractors as a programme of social and political control. Yet, in spite of the hostile environment, black women's use of services has steadily increased. Using historical and anthropological evidence, this paper delineates the links between the social and political context of racial domination and individual fertility behaviour. It is argued that the quantitative success of the family planning programme is rooted in social and economic shifts conditioning reproductive authority and fertility decision-making. State policies of racial segregation and influx control, ethnic 'homeland' politics, and labour migration of men transformed opportunities and constraints for black women and men, and altered local and household expectations of childbearing. Women came to manage their own fertility as they increasingly found themselves in precarious social and economic circumstances.

  2. Role of oxidative stress in female reproduction.

    Science.gov (United States)

    Agarwal, Ashok; Gupta, Sajal; Sharma, Rakesh K

    2005-07-14

    In a healthy body, ROS (reactive oxygen species) and antioxidants remain in balance. When the balance is disrupted towards an overabundance of ROS, oxidative stress (OS) occurs. OS influences the entire reproductive lifespan of a woman and even thereafter (i.e. menopause). OS results from an imbalance between prooxidants (free radical species) and the body's scavenging ability (antioxidants). ROS are a double-edged sword - they serve as key signal molecules in physiological processes but also have a role in pathological processes involving the female reproductive tract. ROS affect multiple physiological processes from oocyte maturation to fertilization, embryo development and pregnancy. It has been suggested that OS modulates the age-related decline in fertility. It plays a role during pregnancy and normal parturition and in initiation of preterm labor. Most ovarian cancers appear in the surface epithelium, and repetitive ovulation has been thought to be a causative factor. Ovulation-induced oxidative base damage and damage to DNA of the ovarian epithelium can be prevented by antioxidants. There is growing literature on the effects of OS in female reproduction with involvement in the pathophysiology of preeclampsia, hydatidiform mole, free radical-induced birth defects and other situations such as abortions. Numerous studies have shown that OS plays a role in the pathophysiology of infertility and assisted fertility. There is some evidence of its role in endometriosis, tubal and peritoneal factor infertility and unexplained infertility. This article reviews the role OS plays in normal cycling ovaries, follicular development and cyclical endometrial changes. It also discusses OS-related female infertility and how it influences the outcomes of assisted reproductive techniques. The review comprehensively explores the literature for evidence of the role of oxidative stress in conditions such as abortions, preeclampsia, hydatidiform mole, fetal embryopathies, preterm

  3. Role of oxidative stress in female reproduction

    Directory of Open Access Journals (Sweden)

    Sharma Rakesh K

    2005-07-01

    Full Text Available Abstract In a healthy body, ROS (reactive oxygen species and antioxidants remain in balance. When the balance is disrupted towards an overabundance of ROS, oxidative stress (OS occurs. OS influences the entire reproductive lifespan of a woman and even thereafter (i.e. menopause. OS results from an imbalance between prooxidants (free radical species and the body's scavenging ability (antioxidants. ROS are a double-edged sword – they serve as key signal molecules in physiological processes but also have a role in pathological processes involving the female reproductive tract. ROS affect multiple physiological processes from oocyte maturation to fertilization, embryo development and pregnancy. It has been suggested that OS modulates the age-related decline in fertility. It plays a role during pregnancy and normal parturition and in initiation of preterm labor. Most ovarian cancers appear in the surface epithelium, and repetitive ovulation has been thought to be a causative factor. Ovulation-induced oxidative base damage and damage to DNA of the ovarian epithelium can be prevented by antioxidants. There is growing literature on the effects of OS in female reproduction with involvement in the pathophsiology of preeclampsia, hydatidiform mole, free radical-induced birth defects and other situations such as abortions. Numerous studies have shown that OS plays a role in the pathoysiology of infertility and assisted fertility. There is some evidence of its role in endometriosis, tubal and peritoneal factor infertility and unexplained infertility. This article reviews the role OS plays in normal cycling ovaries, follicular development and cyclical endometrial changes. It also discusses OS-related female infertility and how it influences the outcomes of assisted reproductive techniques. The review comprehensively explores the literature for evidence of the role of oxidative stress in conditions such as abortions, preeclampsia, hydatidiform mole, fetal

  4. Annual cycle of plasma testosterone in male copperheads, Agkistrodon contortrix (Serpentes, Viperidae): relationship to timing of spermatogenesis, mating, and agonistic behavior.

    Science.gov (United States)

    Schuett, G W; Harlow, H J; Rose, J D; Van Kirk, E A; Murdoch, W J

    1997-03-01

    Reproductive cycles of the majority of squamate reptiles remain undescribed. Few studies are available on seasonal patterns of circulating steroid hormones in snakes. The goal of this study was to document the annual cycle of plasma testosterone (T) in male copperheads Agkistrodon contortrix, a North American pitviper (Serpentes, Viperidae). Two experimental conditions were used in this laboratory study. One condition (repeat-test group) consisted of 10 adult males that were sampled once each month for 11 months. The other condition (single-test groups) consisted of 10 groups each with 5 males (N = 50), and each male was tested a single time. The single-test condition was used to evaluate whether or not repeated handling and sampling affected T levels. The study was conducted from February-December, 1992. A well-defined seasonal pattern of plasma T levels was detected; patterns were similar under both experimental conditions with the exception that the repeat-test group had slightly lower levels. Levels of T were lowest (baseline) in April-May, increased in early summer (June), and were highest in late summer (August). Thereafter, T levels declined up to the time of hibernation (early November) and changed little during hibernation (November-January). Upon emergence from hibernation in late winter (February), T levels increased sharply from February to March and then decreased from March to April. The results are discussed in the context of timing of spermatogenesis, mating, and male agonistic behavior.

  5. Measurement-based quantum repeaters

    CERN Document Server

    Zwerger, M; Briegel, H J

    2012-01-01

    We introduce measurement-based quantum repeaters, where small-scale measurement-based quantum processors are used to perform entanglement purification and entanglement swapping in a long-range quantum communication protocol. In the scheme, pre-prepared entangled states stored at intermediate repeater stations are coupled with incoming photons by simple Bell-measurements, without the need of performing additional quantum gates or measurements. We show how to construct the required resource states, and how to minimize their size. We analyze the performance of the scheme under noise and imperfections, with focus on small-scale implementations involving entangled states of few qubits. We find measurement-based purification protocols with significantly improved noise thresholds. Furthermore we show that already resource states of small size suffice to significantly increase the maximal communication distance. We also discuss possible advantages of our scheme for different set-ups.

  6. A Repeating Fast Radio Burst

    CERN Document Server

    Spitler, L G; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-01-01

    Fast Radio Bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measures (i.e. integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of the fast radio bursts has led several authors to hypothesise that they originate in cataclysmic astrophysical events. Here we report the detection of ten additional bursts from the direction of FRB121102, using the 305-m Arecibo telescope. These new bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and wh...

  7. Human reproductive issues in space

    Science.gov (United States)

    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.

  8. The African catfish, Clarias gariepinus, a model for the study of reproductive endocrinology in teleosts

    NARCIS (Netherlands)

    Oordt, P.G.W.J. van; Goos, H.J.Th.

    1987-01-01

    In their natural habitat African catfish, Clarias gariepinus, show a discontinuous reproductive cycle. This cycle follows changes in the gonadotropic activity of the pituitary. Gonadotropin release has been shown to be under dual hypothalamic control, i.e. a gonadotropin-releasing hormone (GnRH) and

  9. Repeatability of Harris Corner Detector

    Institute of Scientific and Technical Information of China (English)

    HU Lili

    2003-01-01

    Interest point detectors are commonly employed to reduce the amount of data to be processed. The ideal interest point detector would robustly select those features which are most appropriate or salient for the application and data at hand. This paper shows that interest points are geometrically stable under different transformations.This property makes interest points very successful in the context of image matching. To measure this property quantatively, we introduce a evaluation criterion: repeatability rate.

  10. Telomeres, age and reproduction in a long-lived reptile.

    Directory of Open Access Journals (Sweden)

    Virginie Plot

    Full Text Available 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

  11. Influence of mycotoxin zearalenone on the swine reproductive failure

    Directory of Open Access Journals (Sweden)

    Prodanov-Radulović Jasna Z.

    2013-01-01

    Full Text Available Reproductive failure in swine is often a difficult diagnostic problem. If diagnoses of infectious disease or management related problems are not obtained, feed quality and safety may be questioned. Mycotoxins are often present in swine feed in the amount that can have detrimental impact on production and reproduction. Problems are expressed only as alterations of the reproductive cycle, reduced feed intake, slow growth or impaired feed efficiency. In Serbia, generally speaking, high concentrations of mycotoxins were noticed, especially mycotoxin zearalenone. High presence of zearalenone in swine feed is probably due to climatic influence and should be monitored constantly. This paper includes field observations regarding the influence of moldy feed containing mycotoxin zearalenone on the occurrence of the reproductive failure in swine breeding categories (sows, gilts and boars. The material for this research was obtained from four swine farms where certain reproductive disorders and health problems in breeding animals were detected. Depending on the specificity of each evaluated case and available material, the applied research methods included: anamnestic and clinical evaluation, pathomorphological examination, standard laboratory testing for detection of aerobic and anaerobic bacteria, and microbiological feed testing, in order to examine the presence of fungi and mycotoxins by applying the method of thin layer chromatography. On the basis of the obtained results, it could be concluded that mycotoxin zearalenone was detected in all examined feed samples. The presence of mycotoxin in feed was directly related to the reproductive failures in the examined swine categories (vulvovaginitis, endometritis, rebreeding, infertility. Swine reproduction represents the base for intensive swine production. The presence of mycotoxins in swine feed have influence on the reproduction and health status of pigs and under certain conditions may significantly

  12. Intermittent Stem Cell Cycling Balances Self-Renewal and Senescence of the C. elegans Germ Line.

    Directory of Open Access Journals (Sweden)

    Amanda Cinquin

    2016-04-01

    Full Text Available Self-renewing organs often experience a decline in function in the course of aging. It is unclear whether chronological age or external factors control this decline, or whether it is driven by stem cell self-renewal-for example, because cycling cells exhaust their replicative capacity and become senescent. Here we assay the relationship between stem cell cycling and senescence in the Caenorhabditis elegans reproductive system, defining this senescence as the progressive decline in "reproductive capacity," i.e. in the number of progeny that can be produced until cessation of reproduction. We show that stem cell cycling diminishes remaining reproductive capacity, at least in part through the DNA damage response. Paradoxically, gonads kept under conditions that preclude reproduction keep cycling and producing cells that undergo apoptosis or are laid as unfertilized gametes, thus squandering reproductive capacity. We show that continued activity is in fact beneficial inasmuch as gonads that are active when reproduction is initiated have more sustained early progeny production. Intriguingly, continued cycling is intermittent-gonads switch between active and dormant states-and in all likelihood stochastic. Other organs face tradeoffs whereby stem cell cycling has the beneficial effect of providing freshly-differentiated cells and the detrimental effect of increasing the likelihood of cancer or senescence; stochastic stem cell cycling may allow for a subset of cells to preserve proliferative potential in old age, which may implement a strategy to deal with uncertainty as to the total amount of proliferation to be undergone over an organism's lifespan.

  13. Intermittent Stem Cell Cycling Balances Self-Renewal and Senescence of the C. elegans Germ Line.

    Science.gov (United States)

    Cinquin, Amanda; Chiang, Michael; Paz, Adrian; Hallman, Sam; Yuan, Oliver; Vysniauskaite, Indre; Fowlkes, Charless C; Cinquin, Olivier

    2016-04-01

    Self-renewing organs often experience a decline in function in the course of aging. It is unclear whether chronological age or external factors control this decline, or whether it is driven by stem cell self-renewal-for example, because cycling cells exhaust their replicative capacity and become senescent. Here we assay the relationship between stem cell cycling and senescence in the Caenorhabditis elegans reproductive system, defining this senescence as the progressive decline in "reproductive capacity," i.e. in the number of progeny that can be produced until cessation of reproduction. We show that stem cell cycling diminishes remaining reproductive capacity, at least in part through the DNA damage response. Paradoxically, gonads kept under conditions that preclude reproduction keep cycling and producing cells that undergo apoptosis or are laid as unfertilized gametes, thus squandering reproductive capacity. We show that continued activity is in fact beneficial inasmuch as gonads that are active when reproduction is initiated have more sustained early progeny production. Intriguingly, continued cycling is intermittent-gonads switch between active and dormant states-and in all likelihood stochastic. Other organs face tradeoffs whereby stem cell cycling has the beneficial effect of providing freshly-differentiated cells and the detrimental effect of increasing the likelihood of cancer or senescence; stochastic stem cell cycling may allow for a subset of cells to preserve proliferative potential in old age, which may implement a strategy to deal with uncertainty as to the total amount of proliferation to be undergone over an organism's lifespan.

  14. Establishment of the complete life cycle of Spirometra (Cestoda: Diphyllobothriidae) in the laboratory using a newly isolated triploid clone.

    Science.gov (United States)

    Okino, Tetsuya; Ushirogawa, Hiroshi; Matoba, Kumiko; Nishimatsu, Shin-Ichiro; Saito, Mineki

    2017-04-01

    Methods to maintain the life cycle of pathogenic organisms become powerful tools for studying molecular and cellular bases of infectious diseases. Spirometra erinaceieuropaei is a parasitic tapeworm that causes sparganosis in humans. Because S. erinaceieuropaei has a complex life cycle with different stages and host species requirements, there have been no reports to establish the complete life cycle in the laboratory. In this study, using Cyclops as the first intermediate host, mouse as the experimental second intermediate host, and dog as the final host, we succeeded in maintaining S. erinaceieuropaei in the laboratory. By repeating the established life cycle five times, we obtained a clonal population of S. erinaceieuropaei from a single adult worm. A karyotype study showed that the chromosome of this clone is triploid (3n=27), indicating that a genetically uniform strain is established by apomictic reproduction. The strain was named Kawasaki triploid (Kt). A partial sequence of mitochondrial cytochrome c oxidase subunit 1 gene of the strain Kt showed more than 98% similarity with those of S. erinaceieuropaei isolates from Australia, China, and South Korea, and the resultant phylogeny indicated that the strain Kt is a member of a distinctive clade from East Asia and Oceania. Our system will be particularly useful for studies of S. erinaceieuropaei infection and human sparganosis. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Epigenetics of reproductive infertility.

    Science.gov (United States)

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

    2017-06-01

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

  16. Smoking and reproduction.

    Science.gov (United States)

    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.

  17. Laterality and reproductive indices.

    Science.gov (United States)

    Kalichman, Leonid; Kobyliansky, Eugene

    2008-01-01

    Several previous studies support the association between manual dominance and age at menarche or age at menopause. The aim of the present study was to estimate the association between indices of laterality and reproductive indices. The studied sample comprised 650 Chuvashian women aged 18 to 80 years (mean, 46.9; SD = 16.2). The independent-sample t test was used to compare the age at menarche or age at menopause between individuals with right or left dominance of handedness, dominant eye, hand clasping, and arm folding. No significant differences in age at menarche or age at menopause between women with right and left dominance in any of the studied laterality indices were found. This is the first study that simultaneously evaluates the association between dominance in four laterality indices (handedness, dominant eye, hand clasping, and arm folding) and two reproductive indices (age at menarche and age at menopause). Result of our study do not support the hypothesis of a possible association between handedness (and other indices of laterality) and an early age at menarche or age at natural menopause.

  18. Studies on reproductive biology of Mystus tengara (Ham.-Buch., 1822), a freshwater catfish of West Bengal, India

    OpenAIRE

    Sandipan Gupta; Samir Banerjee

    2013-01-01

    Studies on reproductive biology are essential to assess culture potential of a fish species. Mystus tengara is a popular food fish as well as preferred as an ornamental fish in West Bengal. Till date detailed report on reproductive biology of this fish species in the agro-climatic context of West Bengal is lacking. Therefore, the present work was aimed to study the detailed reproductive biology of Mystus tengara with an emphasis on sex ratio, length at first sexual maturity, cycle of gonadal ...

  19. Comparison of serum leptin, glucose, total cholesterol and total protein levels in fertile and repeat breeder cows

    Directory of Open Access Journals (Sweden)

    Saime Guzel

    2014-12-01

    Full Text Available In the present study we measured serum glucose, leptin, total cholesterol and total protein concentrations in repeat breeder cows and compared them with fertile cows. For this aim, 20 repeat breeder cows and 20 fertile cows were used as material. Repeat breeder cows were found to have lower levels of leptin and glucose as compared with fertile ones. No significant differences in total cholesterol and total protein levels were observed between the two groups. No significant correlation of leptin with glucose, total cholesterol and total protein was observed in fertile and repeat breeder cows. Low concentrations of glucose and leptin can have some effects on reproductive problems as repeat breeder and help to understand potential mechanisms impairing fertility in repeat breeder cows.

  20. Origin and fate of repeats in bacteria.

    Science.gov (United States)

    Achaz, G; Rocha, E P C; Netter, P; Coissac, E

    2002-07-01

    We investigated 53 complete bacterial chromosomes for intrachromosomal repeats. In previous studies on eukaryote chromosomes, we proposed a model for the dynamics of repeats based on the continuous genesis of tandem repeats, followed by an active process of high deletion rate, counteracted by rearrangement events that may prevent the repeats from being deleted. The present study of long repeats in the genomes of Bacteria and Archaea suggests that our model of interspersed repeats dynamics may apply to them. Thus the duplication process might be a consequence of very ancient mechanisms shared by all three domains. Moreover, we show that there is a strong negative correlation between nucleotide composition bias and the repeat density of genomes. We hypothesise that in highly biased genomes, non-duplicated small repeats arise more frequently by random effects and are used as primers for duplication mechanisms, leading to a higher density of large repeats.

  1. Safe cycling!

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    The HSE Unit will be running a cycling safety campaign at the entrances to CERN's restaurants on 14, 15 and 16 May. Pop along to see if they can persuade you to get back in the saddle!   With summer on its way, you might feel like getting your bike out of winter storage. Well, the HSE Unit has come up with some original ideas to remind you of some of the most basic safety rules. This year, the prevention campaign will be focussing on three themes: "Cyclists and their equipment", "The bicycle on the road", and "Other road users". This is an opportunity to think about the condition of your bike as well as how you ride it. From 14 to 16 May, representatives of the Swiss Office of Accident Prevention and the Touring Club Suisse will join members of the HSE Unit at the entrances to CERN's restaurants to give you advice on safe cycling (see box). They will also be organising three activity stands where you can test your knowle...

  2. Assisted reproduction in female rhinoceros and elephants--current status and future perspective.

    Science.gov (United States)

    Hermes, R; Göritz, F; Streich, Wj; Hildebrandt, Tb

    2007-09-01

    Over the last few decades, rhinoceroses and elephants became important icons in the saga of wildlife conservation. Recent surveys estimate the wild Asian (Elephas maximus) and African (Loxodonta africana) elephant populations to be, at most, 50 250 and 637 600 respectively. For the five rhinoceros species, black (Diceros bicornis), white (Ceratotherium simum), Indian (Rhinoceros unicornis), Javan (Rhinoceros sondaicus) and Sumatran rhinoceros (Dicerorhinus Sumatrensis), the population estimates of 3610, 11 330, 2400, 60 and 300, respectively, are of even greater concern. Protected against habitat loss, poaching and left undisturbed, rhinoceros and elephants reproduce well in the wild. But small and decreasing populations make successful captive management of these taxa increasingly important. In captivity, however, most populations face possible 'extinction' because of historically poor reproductive performance. From the first descriptions of the reproductive anatomy and the oestrous cycle (Laws 1969; Kassam and Lasley 1981; Balke et al. 1988a,b; Plotka et al. 1988; Godfrey et al. 1991) to the present use of advanced assisted reproduction technologies, researchers have strive to understand the function and dysfunction of the reproductive biology of these charismatic species. This paper reviewed the current knowledge on rhinoceros and elephant reproduction biology, reproductive cycle, gestation, dystocia, reproductive pathology, oestrous induction and artificial insemination, sperm sexing, IVF and contraception, and how this knowledge is or might be used to aid species conservation for maximal reproductive efficiency and enhancement of genetic management.

  3. Bacterial Reproduction and Growth

    NARCIS (Netherlands)

    Scheffers, DJ

    2013-01-01

    Bacteria growing in a suitable medium increase in number by having each cell increase in size, and then each cell divides to produce two daughter cells. The increase in cell number in a culture is, therefore, a result of the activity of the cell during the division cycle, between the period of birth

  4. African Journal of Reproductive Health

    African Journals Online (AJOL)

    AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES ... The African Journal of Reproductive Health is a multidisciplinary and international journal that publishes original research, ... to share findings on all aspects of reproductive health, and to disseminate innovative, relevant ...

  5. Assisted reproductive practice: religious perspectives.

    Science.gov (United States)

    Schenker, Joscph G

    2005-03-01

    It is important to those who practise reproductive techniques to learn about different religious perspectives related to reproductive health problems. Religious groups are active in influencing the public regarding bioethical positions, and this is particularly evident with issues concerning procreation, abortion and infertility therapy. 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. The attitude toward reproductive practice varies among Christian groups. While assisted reproduction is not accepted by the Vatican, it may be practised by Protestant, Anglican and other denominations. According to traditional Christian views, beginning at conception, the embryo has moral status as a human being, and thus most assisted reproductive technologies are forbidden. According to Islam, the procedures of IVF and embryo transfer are acceptable, although they can be performed only for husband and wife. 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. This paper presents the attitude of monotheistic religions 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.

  6. Genetic aspects of female reproduction

    NARCIS (Netherlands)

    Collins, J.; Diedrich, K.; Franks, S.; Geraedts, J. P. M.; Jacobs, P. A.; Karges, B.; Kennedy, S.; Marozzi, A.; Regan, L.; Baird, D. T.; Crosignani, P. G.; Devroey, P.; Diczfalusy, E.; Evers, J. L. H.; Fauser, B. C. J. M.; Fraser, L.; Gianaroli, L.; Glasier, A.; Liebaers, I.; Ragni, G.; Sunde, A.; Tarlatzis, B.; Van Steirteghem, A.

    2008-01-01

    BACKGROUND: Sexual reproduction provides the means for preserving genetic identity and in turn, genetic variability may affect the ability to reproduce. This review aims to summarize current research on genetic diagnosis and genetic causes of reproductive disorders.METHODS: Searches were done by sub

  7. Involvement of inositol in reproduction.

    NARCIS (Netherlands)

    Beemster, P.; Groenen, P.; Steegers-Theunissen, R.P.M.

    2002-01-01

    Inositol is involved in several aspects of reproduction. It affects overall embryogenesis, may prevent ne