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Sample records for preovulatory lh surge

  1. Neurokinin-3 Receptor Activation in the Retrochiasmatic Area is Essential for the Full Preovulatory LH Surge in Ewes

    Science.gov (United States)

    Porter, Katrina L.; Hileman, Stanley M.; Hardy, Steven L.; Nestor, Casey C; Lehman, Michael N.; Goodman, Robert L.

    2014-01-01

    Neurokinin B (NKB) is essential for human reproduction and has been shown to stimulate LH secretion in several species, including sheep. Ewes express the neurokinin-3 receptor (NK3R) in the retrochiasmatic area (RCh) and there is one report that placement of senktide, an NK3R agonist, therein stimulates LH secretion that resembles an LH surge in ewes. In this study, we first confirmed that local administration of senktide to the RCh produced a surge-like increase in LH secretion, and then tested the effects of this agonist in two other areas implicated in the control of LH secretion and where NK3R is found in high abundance: the preoptic area (POA) and arcuate nucleus (ARC). Bilateral microimplants containing senktide induced a dramatic surge-like increase in LH when given in the POA similar to that seen with RCh treatment. In contrast, senktide treatment in the ARC resulted in a much smaller, but significant, increase in LH concentrations suggestive of an effect on tonic secretion. The possible role of POA and RCh NK3R activation in the LH surge was next tested by treating ewes with SB222200, an NK3R antagonist, in each area during an E2-induced LH surge. SB222200 in the RCh, but not in the POA, reduced LH surge amplitude by about 40% compared to controls, indicating that NK3R activation in the former region is essential for full expression of the preovulatory LH surge. Based on these data, we propose that NKB actions in the RCh are an important component of the preovulatory LH surge in ewes. PMID:25040132

  2. Cetrorelix suppresses the preovulatory LH surge and ovulation induced by ovulation-inducing factor (OIF present in llama seminal plasma

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    Letelier Claudia

    2011-05-01

    Full Text Available Abstract Background The purpose of the study was to determine if the effect of llama OIF on LH secretion is mediated by stimulation of the hypothalamus or pituitary gland. Methods Using a 2-by-2 factorial design to examine the effects of OIF vs GnRH with or without a GnRH antagonist, llamas with a growing ovarian follicle greater than or equal to 8 mm were assigned randomly to four groups (n = 7 per group and a pre-treated with 1.5 mg of GnRH antagonist (cetrorelix acetate followed by 1 mg of purified llama OIF, b pre-treated with 1.5 mg of cetrorelix followed by 50 micrograms of GnRH, c pre-treated with a placebo (2 ml of saline followed by 1 mg of purified llama OIF or d pre-treated with a placebo (2 ml of saline followed by 50 micrograms of GnRH. Pre-treatment with cetrorelix or saline was given as a single slow intravenous dose 2 hours before intramuscular administration of either GnRH or OIF. Blood samples for LH measurement were taken every 15 minutes from 1.5 hours before to 8 hours after treatment. The ovaries were examined by ultrasonography to detect ovulation and CL formation. Blood samples for progesterone measurement were taken every-other-day from Day 0 (day of treatment to Day 16. Results Ovulation rate was not different (P = 0.89 between placebo+GnRH (86% and placebo+OIF groups (100%; however, no ovulations were detected in llamas pre-treated with cetrorelix. Plasma LH concentrations surged (P Conclusion Cetrorelix (GnRH antagonist inhibited the preovulatory LH surge induced by OIF in llamas suggesting that LH secretion is modulated by a direct or indirect effect of OIF on GnRH neurons in the hypothalamus.

  3. Cetrorelix suppresses the preovulatory LH surge and ovulation induced by ovulation-inducing factor (OIF) present in llama seminal plasma.

    Science.gov (United States)

    Silva, Mauricio E; Smulders, Juan P; Guerra, Monserrat; Valderrama, Ximena P; Letelier, Claudia; Adams, Gregg P; Ratto, Marcelo H

    2011-05-30

    The purpose of the study was to determine if the effect of llama OIF on LH secretion is mediated by stimulation of the hypothalamus or pituitary gland. Using a 2-by-2 factorial design to examine the effects of OIF vs GnRH with or without a GnRH antagonist, llamas with a growing ovarian follicle greater than or equal to 8 mm were assigned randomly to four groups (n = 7 per group) and a) pre-treated with 1.5 mg of GnRH antagonist (cetrorelix acetate) followed by 1 mg of purified llama OIF, b) pre-treated with 1.5 mg of cetrorelix followed by 50 micrograms of GnRH, c) pre-treated with a placebo (2 ml of saline) followed by 1 mg of purified llama OIF or d) pre-treated with a placebo (2 ml of saline) followed by 50 micrograms of GnRH. Pre-treatment with cetrorelix or saline was given as a single slow intravenous dose 2 hours before intramuscular administration of either GnRH or OIF. Blood samples for LH measurement were taken every 15 minutes from 1.5 hours before to 8 hours after treatment. The ovaries were examined by ultrasonography to detect ovulation and CL formation. Blood samples for progesterone measurement were taken every-other-day from Day 0 (day of treatment) to Day 16. Ovulation rate was not different (P = 0.89) between placebo+GnRH (86%) and placebo+OIF groups (100%); however, no ovulations were detected in llamas pre-treated with cetrorelix. Plasma LH concentrations surged (P llamas suggesting that LH secretion is modulated by a direct or indirect effect of OIF on GnRH neurons in the hypothalamus.

  4. Role of exogenous estrogen in initiation of estrus and induction of an LH surge

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    Among cattle the LH surge that causes ovulation occurs shortly after the onset of a spontaneous estrus. In addition an injection of 100 'g of GnRH can induce an LH surge capable of inducing ovulation. We hypothesized that different preovulatory estradiol profiles would result in different ovulator...

  5. Circadian control of kisspeptin and a gated GnRH response mediate the preovulatory luteinizing hormone surge

    DEFF Research Database (Denmark)

    Williams, Wilbur P; Jarjisian, Stephan G; Mikkelsen, Jens D

    2011-01-01

    In spontaneously ovulating rodents, the preovulatory LH surge is initiated on the day of proestrus by a timed, stimulatory signal originating from the circadian clock in the suprachiasmatic nucleus (SCN). The present studies explored whether kisspeptin is part of the essential neural circuit...... linking the SCN to the GnRH system to stimulate ovulation in Syrian hamsters (Mesocricetus auratus). Kisspeptin neurons exhibit an estrogen-dependent, daily pattern of cellular activity consistent with a role in the circadian control of the LH surge. The SCN targets kisspeptin neurons via vasopressinergic...... of ovulatory control with interactions among the circadian system, kisspeptin signaling, and a GnRH gating mechanism of control....

  6. Circadian Control of the Estrogenic Circuits Regulating GnRH Secretion and the Preovulatory Luteinizing Hormone Surge

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    Lance J Kriegsfeld

    2012-05-01

    Full Text Available Female reproduction requires the precise temporal organization of interacting, estradiol-sensitive neural circuits that converge to optimally drive hypothalamo-pituitary-gonadal (HPG axis functioning. In mammals, the master circadian pacemaker in the suprachaismatic nucleus (SCN of the anterior hypothalamus coordinates reproductively-relevant neuroendocrine events necessary to maximize reproductive success. Likewise, in species where periods of fertility are brief, circadian oversight of reproductive function ensures that estradiol-dependent increases in sexual motivation coincide with ovulation. Across species, including humans, disruptions to circadian timing (e.g., through rotating shift work, night shift work, poor sleep hygiene lead to pronounced deficits in ovulation and fecundity. Despite the well-established roles for the circadian system in female reproductive functioning, the specific neural circuits and neurochemical mediators underlying these interactions are not fully understood. Most work to date has focused on the direct and indirect communication from the SCN to the GnRH system in control of the preovulatory LH surge. However, the same clock genes underlying circadian rhythms at the cellular level in SCN cells are also common to target cell populations of the SCN, including the GnRH neuronal network. Exploring the means by which the master clock synergizes with subordinate clocks in GnRH cells and its upstream modulatory systems represents an exciting opportunity to further understand the role of endogenous timing systems in female reproduction. Herein we provide an overview of the state of knowledge regarding interactions between the circadian timing system and estradiol-sensitive neural circuits driving GnRH secretion and the preovulatory LH surge.

  7. Developmental programming: Prenatal BPA treatment disrupts timing of LH surge and ovarian follicular wave dynamics in adult sheep

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    Veiga-Lopez, A.; Beckett, E.M.; Abi Salloum, B.; Ye, W.; Padmanabhan, V.

    2014-01-01

    Developmental exposure to BPA adversely affects reproductive function. In sheep, prenatal BPA treatment induces reproductive neuroendocrine defects, manifested as LH excess and dampened LH surge and perturbs early ovarian gene expression. In this study we hypothesized that prenatal BPA treatment will also disrupt ovarian follicular dynamics. Pregnant sheep were treated from days 30 to 90 of gestation with 3 different BPA doses (0.05, 0.5, or 5 mg/kg BW/day). All female offspring were estrus synchronized and transrectal ultrasonography was performed daily for 22 days to monitor ovarian follicular and corpora lutea dynamics. Blood samples were collected to assess preovulatory hormonal changes and luteal progesterone dynamics. Statistical analysis revealed that the time interval between the estradiol rise and the preovulatory LH surge was shortened in the BPA-treated females. None of the three BPA doses had an effect on corpora lutea, progestogenic cycles, and mean number or duration of ovulatory and non-ovulatory follicles. However, differences in follicular count trajectories were evident in all three follicular size classes (2–3 mm, 4–5 mm, and ≥ 6 mm) of prenatal BPA-treated animals compared to controls. Number of follicular waves tended also to be more variable in the prenatal BPA-treated groups ranging from 2 to 5 follicular waves per cycle, while this was restricted to 3 to 4 waves in control females. These changes in ovarian follicular dynamics coupled with defects in time interval between estradiol rise and preovulatory LH release are likely to lead to subfertility in prenatal BPA-treated females. - Highlights: • Prenatal BPA shortens interval between estradiol rise and preovulatory LH surge. • Prenatal BPA affects follicular count trajectory and follicular wave occurrence. • Prenatal BPA does not affect ovulatory rate and progesterone dynamics

  8. Developmental programming: Prenatal BPA treatment disrupts timing of LH surge and ovarian follicular wave dynamics in adult sheep

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    Veiga-Lopez, A.; Beckett, E.M.; Abi Salloum, B. [Department of Pediatrics, University of Michigan, Ann Arbor, MI (United States); Ye, W. [Department of Biostatistics, University of Michigan, Ann Arbor, MI (United States); Padmanabhan, V., E-mail: vasantha@umich.edu [Department of Pediatrics, University of Michigan, Ann Arbor, MI (United States); The Reproductive Sciences Program, University of Michigan, Ann Arbor, MI (United States)

    2014-09-01

    Developmental exposure to BPA adversely affects reproductive function. In sheep, prenatal BPA treatment induces reproductive neuroendocrine defects, manifested as LH excess and dampened LH surge and perturbs early ovarian gene expression. In this study we hypothesized that prenatal BPA treatment will also disrupt ovarian follicular dynamics. Pregnant sheep were treated from days 30 to 90 of gestation with 3 different BPA doses (0.05, 0.5, or 5 mg/kg BW/day). All female offspring were estrus synchronized and transrectal ultrasonography was performed daily for 22 days to monitor ovarian follicular and corpora lutea dynamics. Blood samples were collected to assess preovulatory hormonal changes and luteal progesterone dynamics. Statistical analysis revealed that the time interval between the estradiol rise and the preovulatory LH surge was shortened in the BPA-treated females. None of the three BPA doses had an effect on corpora lutea, progestogenic cycles, and mean number or duration of ovulatory and non-ovulatory follicles. However, differences in follicular count trajectories were evident in all three follicular size classes (2–3 mm, 4–5 mm, and ≥ 6 mm) of prenatal BPA-treated animals compared to controls. Number of follicular waves tended also to be more variable in the prenatal BPA-treated groups ranging from 2 to 5 follicular waves per cycle, while this was restricted to 3 to 4 waves in control females. These changes in ovarian follicular dynamics coupled with defects in time interval between estradiol rise and preovulatory LH release are likely to lead to subfertility in prenatal BPA-treated females. - Highlights: • Prenatal BPA shortens interval between estradiol rise and preovulatory LH surge. • Prenatal BPA affects follicular count trajectory and follicular wave occurrence. • Prenatal BPA does not affect ovulatory rate and progesterone dynamics.

  9. Neurosteroids, trigger of the LH surge

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    Kuo, John; Micevych, Paul

    2012-01-01

    Recent experiments from our laboratory are consistent with the idea that hypothalamic astrocytes are critical components of the central nervous system (CNS) mediated estrogen positive feedback mechanism. The “astrocrine hypothesis” maintains that ovarian estradiol rapidly increases free cytoplasmic calcium concentrations ([Ca2+]i) that facilitate progesterone synthesis in astrocytes. This hypothalamic neuroprogesterone along with the elevated estrogen from the ovaries allows for the surge release of gonadotropin-releasing hormone (GnRH) that triggers the pituitary luteinizing hormone (LH) surge. A narrow range of estradiol stimulated progesterone production supports an “off-on-off” mechanism regulating the transition from estrogen negative feedback to estrogen positive feedback, and back again. The rapidity of the [Ca2+]i response and progesterone synthesis support a non-genomic, membrane-initiated signaling mechanism. In hypothalamic astrocytes, membrane-associated estrogen receptors (mERs) signal through transactivation of the metabotropic glutamate receptor type 1a (mGluR1a), implying that astrocytic function is influenced by surrounding glutamatergic nerve terminals. Although other putative mERs, such as mERβ, STX-activated mER-Gαq, and G protein-coupled receptor 30 (GPR30), are present and participate in membrane-mediated signaling, their influence in reproduction is still obscure since female reproduction be it estrogen positive feedback or lordosis behavior requires mERα. The astrocrine hypothesis is also consistent with the well-known sexual dimorphism of estrogen positive feedback. In rodents, only post-pubertal females exhibit this positive feedback. Hypothalamic astrocytes cultured from females, but not males, responded to estradiol by increasing progesterone synthesis. Estrogen autoregulates its own signaling by regulating levels of mERα in the plasma membrane of female astrocytes. In male astrocytes, the estradiol-induced increase in m

  10. Developmental programming: Prenatal BPA treatment disrupts timing of LH surge and ovarian follicular wave dynamics in adult sheep

    Science.gov (United States)

    Veiga-Lopez, A; Beckett, EM; Abi Salloum, B; Ye, W; Padmanabhan, V

    2014-01-01

    Developmental exposure to BPA adversely affects reproductive function. In sheep, prenatal BPA treatment induces reproductive neuroendocrine defects, manifested as LH excess and dampened LH surge and perturbs early ovarian gene expression. In this study we hypothesized that prenatal BPA treatment will also disrupt ovarian follicular dynamics. Pregnant sheep were treated from days 30 to 90 of gestation with 3 different BPA doses (0.05, 0.5, or 5 mg/kg BW/day). All female offspring were estrus synchronized and transrectal ultrasonography was performed daily for 22 days to monitor ovarian follicular and corpora lutea dynamics. Blood samples were collected to assess hormonal preovulatory changes and luteal progesterone dynamics. Statistical analysis revealed that the time interval between the estradiol rise and the preovulatory LH surge was shortened in the BPA-treated females. None of the three BPA doses had an effect on corpora lutea, progestogenic cycles, and mean or duration of ovulatory and non-ovulatory follicles. However, differences in follicular count trajectories were evident in all three follicular size classes (2–3 mm, 4–5 mm, and ≥ 6 mm) of prenatal BPA-treated animals compared to controls. Number of follicular waves tended also to be more variable in the prenatal BPA-treated groups ranging from 2 to 5 follicular waves per cycle, while this was restricted to 3 to 4 waves in control females. These changes in ovarian follicular dynamics coupled with defects in time interval between estradiol rise and preovulatory LH release are likely to lead to subfertility in prenatal BPA-treated females. PMID:24923655

  11. Phenobarbital blockade of the preovulatory luteinizing hormone surge: association with phase-advanced circadian clock and altered suprachiasmatic nucleus Period1 gene expression

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    Legan, Sandra J.; Donoghue, Kathleen M.; Franklin, Kathleen M.; Duncan, Marilyn J.

    2009-01-01

    The suprachiasmatic nucleus (SCN) controls the timing of the preovulatory luteinizing hormone (LH) surge in laboratory rodents. Barbiturate administration during a critical period on proestrus delays the surge and prolongs the estrous cycle 1 day. Because a nonphotic timing signal (zeitgeber) during the critical period that phase advances activity rhythms can also induce the latter effect, we hypothesized that barbiturates delay the LH surge by phase-advancing its circadian timing signal beyond the critical period. In experiment 1, locomotor rhythms and estrous cycles were monitored in hamsters for 2–3 wk preinjection and postinjection of vehicle or phenobarbital and after transfer to darkness at zeitgeber time (ZT) 6 on proestrus. Phenobarbital delayed estrous cycles in five of seven hamsters, which exhibited phase shifts that averaged twofold greater than those exhibited by vehicle controls or phenobarbital-injected hamsters with normal cycles. Experiment 2 used a similar protocol, but injections were at ZT 5, and blood samples for LH determination were collected from 1200 to 1800 on proestrus and the next day via jugular cannulae inserted the day before proestrus. Phenobarbital delayed the LH surge 1 day in all six hamsters, but it occurred at an earlier circadian time, supporting the above hypothesis. Experiment 3 investigated whether phenobarbital, like other nonphotic zeitgebers, suppresses SCN Period1 and Period2 transcription. Two hours postinjection, phenobarbital decreased SCN expression of only Period1 mRNA, as determined by in situ hybridization. These results suggest that phenobarbital advances the SCN pacemaker, governing activity rhythms and hormone release in part by decreasing its Period1 gene expression. PMID:19297538

  12. LH-receptor gene expression in human granulosa and cumulus cells from antral and preovulatory follicles

    DEFF Research Database (Denmark)

    Jeppesen, Janni Vikkelsø; Kristensen, Stine Gry; Nielsen, Maria Eilsø

    2012-01-01

    Context:Human granulosa cells (GC) acquire LH receptor (LHR) expression during the follicular phase of the menstrual cycle. Currently, the precise follicular stage is unknown, and specific roles of LH in the follicular development are not fully understood.Objective:Our objective was to measure LH...

  13. Preovulatory progesterone concentration associates significantly to follicle number and LH concentration but not to pregnancy rate

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    Yding Andersen, Claus; Bungum, Leif; Nyboe Andersen, Anders

    2011-01-01

    Using data from a large prospective randomized controlled trial that evaluated the effect of recombinant LH (rLH)co-administration for ovarian stimulation, the present study assessed whether progesterone concentration on the day of human chorionic gonadotrophin (HCG) administration was associated...... with or without rLH administration from day 6 of stimulation. There was no significant association between the late-follicular-phase progesterone concentration and the clinical pregnancy rate. However, progesterone concentration was strongly associated with the number of follicles and retrieved oocytes. Late......-follicular-phase LH concentration also showed a significant positive association with progesterone concentration (P = 0.018). Administration of rLH during ovarian stimulation did not affect progesterone concentration. The present study does not support an association between progesterone concentration on the day...

  14. Preovulatory progesterone concentration associates significantly to follicle number and LH concentration but not to pregnancy rate

    DEFF Research Database (Denmark)

    Yding Andersen, Claus; Bungum, Leif; Nyboe Andersen, Anders

    2011-01-01

    Using data from a large prospective randomized controlled trial that evaluated the effect of recombinant LH (rLH)co-administration for ovarian stimulation, the present study assessed whether progesterone concentration on the day of human chorionic gonadotrophin (HCG) administration was associated...... with or without rLH administration from day 6 of stimulation. There was no significant association between the late-follicular-phase progesterone concentration and the clinical pregnancy rate. However, progesterone concentration was strongly associated with the number of follicles and retrieved oocytes. Late...

  15. The Two Populations of Kisspeptin Neurons Are Involved in the Ram-Induced LH Pulsatile Secretion and LH Surge in Anestrous Ewes.

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    Fabre-Nys, Claude; Cognié, Juliette; Dufourny, Laurence; Ghenim, Meriem; Martinet, Stephanie; Lasserre, Olivier; Lomet, Didier; Millar, Robert P; Ohkura, Satoshi; Suetomi, Yuta

    2017-11-01

    Exposure to a ram during spring stimulates luteinizing hormone (LH) secretion and can induce ovulation in sexually quiescent ewes ("ram effect"). Kisspeptin (Kiss) present in the arcuate nucleus (ARC) and the preoptic area (POA) is a potent stimulators of LH secretion. Our aim was to investigate whether Kiss neurons mediate the increase in LH secretion during the ram effect. With double immunofluorescent detection, we identified Kiss neurons (Kiss IR) activated (Fos IR) by exposure to a ram for 2 hours (M2) or 12 hours (M12) or to ewes for 2 hours (C). The density of cells Kiss + Fos IR and the proportion of Kiss IR cells that were also Fos IR cells were higher in M2 and M12 than in C in ARC (P populations of Kiss neurons are involved in the ram-induced pulsatile LH secretion and in the LH surge. Copyright © 2017 Endocrine Society.

  16. Kit ligand promotes first polar body extrusion of mouse preovulatory oocytes

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    Ye Yinghui

    2009-04-01

    Full Text Available Abstract Background Shortly after stimulation by the preovulatory surge of luteinizing hormone (LH, oocytes arrested at the late prophase I resume meiosis characterized by germinal vesicle breakdown (GVBD, chromosome condensation, and extrusion of the first polar body in preparation for fertilization and early embryonic development. However, oocytes express few or no LH receptors and are insensitive to direct LH stimulation. Thus, factors released by granulosa or theca cells expect to convey the LH stimuli to oocytes. To identify candidate ligand-receptor pairs potentially involved in the process of oocyte maturation, we performed DNA microarray analyses of ovarian transcripts in mice and identified Kit ligand (Kitl as an ovarian factor stimulated by the LH/hCG surge. The purpose of this study is to investigate the roles of KITL in the nuclear and cytoplasmic maturation of preovulatory mouse oocytes. Methods The levels of Kitl and c-kit transcripts in mouse ovaries and isolated ovarian cells were determined by real-time RT-PCR, while expression of KITL protein was examined by immunohistochemistry. Follicle culture, cumulus-oocyte complexes (COC and denuded oocytes culture were used to evaluate the effect of KITL on mouse oocyte nuclear maturation. To assess the effect of KITL treatment on the cytoplasmic maturation of preovulatory oocytes, we performed in vitro maturation of oocytes followed by in vitro fertilization. Results Major increase of Kitl transcripts in granulosa cells and mouse ovaries, and predominant expression of c-kit in preovulatory oocytes were identified by real-time RT-PCR. Predominant expression of KITL protein was found in granulosa cells of preovulatory and small antral follicles at 4 h after hCG treatment. In vitro cultures demonstrated that treatment with KITL enhanced first polar body extrusion in a dose-dependent manner. Moreover, treatment of COC with KITL enhanced first polar body extrusion with increase in cyclin B1

  17. Steroid hormones content and proteomic analysis of canine follicular fluid during the preovulatory period

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    Reynaud Karine

    2010-11-01

    Full Text Available Abstract Background Follicular fluid contains substances involved in follicle activity, cell differentiation and oocyte maturation. Studies of its components may contribute to better understanding of the mechanisms underlying follicular development and oocyte quality. The canine species is characterized by several ovarian activity features that are not extensively described such as preovulatory luteinization, oocyte ovulated at the GV stage (prophase 1 and poly-oocytic follicles. In this study, we examined the hypothesis that the preovulatory LH surge is associated with changes in steroid and protein content of canine follicular fluid prior to ovulation. Methods Follicular fluid samples were collected from canine ovaries during the preovulatory phase, before (pre-LH; n = 16 bitches and after (post-LH; n = 16 the LH surge. Blood was simultaneously collected. Steroids were assayed by radioimmunoassay and proteomic analyses were carried out by 2D-PAGE and mass spectrometry. Results The concentrations of 17beta-estradiol and progesterone at the pre-LH stage were 737.2 +/- 43.5 ng/ml and 2630.1 +/- 287.2 ng/ml in follicular fluid vs. 53 +/- 4.1 pg/ml and 3.9 +/- 0.3 ng/ml in plasma, respectively. At that stage, significant positive correlations between follicular size and intra-follicular steroid concentrations were recorded. After the LH peak, the intrafollicular concentration of 17beta-estradiol decreased significantly (48.3 +/- 4.4 ng/ml; p Proteomic analysis of canine follicular fluid identified 38 protein spots, corresponding to 21 proteins, some of which are known to play roles in the ovarian physiology. The comparison of 2D-PAGE patterns of follicular fluids from the pre- and post-LH stages demonstrated 3 differentially stained single spot or groups of spots. One of them was identified as complement factor B. A comparison of follicular fluid and plasma protein patterns demonstrated a group of 4 spots that were more concentrated in plasma than

  18. Global but not gonadotrope-specific disruption of Bmal1 abolishes the luteinizing hormone surge without affecting ovulation

    DEFF Research Database (Denmark)

    Chu, Adrienne; Zhu, Lei; Blum, Ian D

    2013-01-01

    While there is evidence for a circadian regulation of the preovulatory luteinizing hormone (LH) surge, the contributions of individual tissue clocks to this process remain unclear. We studied female mice deficient in the Bmal1 gene (Bmal1(-/-)), which is essential for circadian clock function, an...

  19. Developmental Programming: Prenatal and Postnatal Androgen Antagonist and Insulin Sensitizer Interventions Prevent Advancement of Puberty and Improve LH Surge Dynamics in Prenatal Testosterone-Treated Sheep.

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    Padmanabhan, Vasantha; Veiga-Lopez, Almudena; Herkimer, Carol; Abi Salloum, Bachir; Moeller, Jacob; Beckett, Evan; Sreedharan, Rohit

    2015-07-01

    Prenatal T excess induces maternal hyperinsulinemia, early puberty, and reproductive/metabolic defects in the female similar to those seen in women with polycystic ovary syndrome. This study addressed the organizational/activational role of androgens and insulin in programming pubertal advancement and periovulatory LH surge defects. Treatment groups included the following: 1) control; 2) prenatal T; 3) prenatal T plus prenatal androgen antagonist, flutamide; 4) prenatal T plus prenatal insulin sensitizer, rosiglitazone; 5) prenatal T and postnatal flutamide; 6) prenatal T and postnatal rosiglitazone; and 7) prenatal T and postnatal metformin. Prenatal treatments spanned 30-90 days of gestation and postnatal treatments began at approximately 8 weeks of age and continued throughout. Blood samples were taken twice weekly, beginning at approximately 12 weeks of age to time puberty. Two-hour samples after the synchronization with prostaglandin F2α were taken for 120 hours to characterize LH surge dynamics at 7 and 19 months of age. Prenatal T females entered puberty earlier than controls, and all interventions prevented this advancement. Prenatal T reduced the percentage of animals having LH surge, and females that presented LH surge exhibited delayed timing and dampened amplitude of the LH surge. Prenatal androgen antagonist, but not other interventions, restored LH surges without normalizing the timing of the surge. Normalization of pubertal timing with prenatal/postnatal androgen antagonist and insulin sensitizer interventions suggests that pubertal advancement is programmed by androgenic actions of T involving insulin as a mediary. Restoration of LH surges by cotreatment with androgen antagonist supports androgenic programming at the organizational level.

  20. Gene expression profiling of preovulatory follicle in the buffalo cow: effects of increased IGF-I concentration on periovulatory events.

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    Jyotsna U Rao

    Full Text Available The preovulatory follicle in response to gonadotropin surge undergoes dramatic biochemical, and morphological changes orchestrated by expression changes in hundreds of genes. Employing well characterized bovine preovulatory follicle model, granulosa cells (GCs and follicle wall were collected from the preovulatory follicle before, 1, 10 and 22 h post peak LH surge. Microarray analysis performed on GCs revealed that 450 and 111 genes were differentially expressed at 1 and 22 h post peak LH surge, respectively. For validation, qPCR and immunocytochemistry analyses were carried out for some of the differentially expressed genes. Expression analysis of many of these genes showed distinct expression patterns in GCs and the follicle wall. To study molecular functions and genetic networks, microarray data was analyzed using Ingenuity Pathway Analysis which revealed majority of the differentially expressed genes to cluster within processes like steroidogenesis, cell survival and cell differentiation. In the ovarian follicle, IGF-I is established to be an important regulator of the above mentioned molecular functions. Thus, further experiments were conducted to verify the effects of increased intrafollicular IGF-I levels on the expression of genes associated with the above mentioned processes. For this purpose, buffalo cows were administered with exogenous bGH to transiently increase circulating and intrafollicular concentrations of IGF-I. The results indicated that increased intrafollicular concentrations of IGF-I caused changes in expression of genes associated with steroidogenesis (StAR, SRF and apoptosis (BCL-2, FKHR, PAWR. These results taken together suggest that onset of gonadotropin surge triggers activation of various biological pathways and that the effects of growth factors and peptides on gonadotropin actions could be examined during preovulatory follicle development.

  1. Bidirectional impact of atrazine-induced elevations in progesterone (P4) on the LH surge in the ovariectomized, estradiol (E2)-primed rat

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    Multiple daily exposures to the herbicide atrazine (ATZ) have been reported to suppress the luteinizing hormone surge (LHS) in female rats. Exposure has also been found to elevate P4 concentrations, and an increase in P4 is known to have a different directional effect on LH depe...

  2. Bidirectional impact of atrazine-induced elvations in progesterone (P4) on the LH Surge in the ovariectomized (OVX), estradiol (E2)-primed rat

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    Multiple daily exposures to the herbicide atrazine (ATZ) have been reported to suppress the luteinizing hormone surge (LHS) in female rats. Exposure has also been found to elevate P4 concentrations, and an increase in P4 is known to have a different directional effect on LH depen...

  3. Progesterone improves the maturation of male-induced preovulatory follicles in anoestrous ewes.

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    Adib, Achraf; Freret, Sandrine; Touze, Jean-Luc; Lomet, Didier; Lardic, Lionel; Chesneau, Didier; Estienne, Anthony; Papillier, Pascal; Monniaux, Danielle; Pellicer-Rubio, Maria-Teresa

    2014-10-01

    The first ovulation induced by male effect in sheep during seasonal anoestrus usually results in the development of a short cycle that can be avoided by progesterone priming before ram introduction. In elucidating the involvement of the hypothalamic-pituitary-gonadal axis in the occurrence of short cycles, the effects of progesterone and the time of anoestrus on the development of male-induced preovulatory follicles were investigated in anoestrous ewes using morphological, endocrine and molecular approaches. Ewes were primed with progesterone for 2 (CIDR2) or 12 days (CIDR12) and untreated ewes used as controls during early (April) and late (June) anoestrus. The duration of follicular growth and the lifespan of the male-induced preovulatory follicles were prolonged by ∼1.6 days in CIDR12 ewes compared with the controls. These changes were accompanied by a delay in the preovulatory LH and FSH surges and ovulation. Intra-follicular oestradiol concentration and mRNA levels of LHCGR and STAR in the granulosa and theca cells of the preovulatory follicles were higher in CIDR12 ewes than the control ewes. The expression of mRNA levels of CYP11A1 and CYP17A1 also increased in theca cells of CIDR12 ewes. CIDR2 ewes gave intermediate results. Moreover, ewes ovulated earlier in June than in April, without changes in the duration of follicular growth, but these effects were unrelated to the lifespan of corpus luteum. Our results give the first evidence supporting the positive effect of progesterone priming on the completion of growth and maturation of preovulatory follicles induced by male effect in seasonal anoestrous ewes, thereby preventing short cycles. © 2014 Society for Reproduction and Fertility.

  4. New stimulation regimens: endogenous and exogenous progesterone use to block the LH surge during ovarian stimulation for IVF.

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    Massin, Nathalie

    2017-03-01

    The advent of embryo and oocyte vitrification today gives reproductive specialists an opportunity to consider new strategies for improving the practice and results of IVF attempts. As the freezing of entire cohorts does not compromise, and may even improve, the results of IVF attempts, it is possible to break away from the standard sequence of stimulation-retrieval-transfer. The constraints associated with ovarian stimulation in relation to the potential harmful effects of the hormonal environment on endometrial receptivity can be avoided. This review will look at the new stimulation protocols where progesterone is used to block the LH surge. Thanks to 'freeze all' strategies, the increase in progesterone could actually be no longer a cause for concern. There are two ways of using progesterone, whether it be endogenous, as in luteal phase stimulation, or exogenous, as in the use of progesterone in the follicular phase i.e. progestin primed ovarian stimulation. A literature search was carried out (until September 2016) on MEDLINE. The following text words were utilized to generate the list of citations: progestin primed ovarian stimulation, luteal phase stimulation, luteal stimulation, duostim, double stimulation, random start. Articles and their references were then examined in order to identify other potential studies. All of the articles are reported in this review. The use of progesterone during ovarian stimulation is effective in blocking the LH surge, whether endogenous or exogenous, and it does not affect the number of oocytes collected or the quality of the embryos obtained. Its main constraint is that it requires total freezing and delayed transfer. A variety of stimulation protocols can be derived from these two methods, and their implications are discussed, from fertility preservation to ovarian response profiles to organization for the patients and clincs. These new regimens enable more flexibility and are of emerging interest in daily practice. However

  5. Developmental Programming: Prenatal and Postnatal Androgen Antagonist and Insulin Sensitizer Interventions Prevent Advancement of Puberty and Improve LH Surge Dynamics in Prenatal Testosterone-Treated Sheep

    OpenAIRE

    Padmanabhan, Vasantha; Veiga-Lopez, Almudena; Herkimer, Carol; Abi Salloum, Bachir; Moeller, Jacob; Beckett, Evan; Sreedharan, Rohit

    2015-01-01

    Prenatal T excess induces maternal hyperinsulinemia, early puberty, and reproductive/metabolic defects in the female similar to those seen in women with polycystic ovary syndrome. This study addressed the organizational/activational role of androgens and insulin in programming pubertal advancement and periovulatory LH surge defects. Treatment groups included the following: 1) control; 2) prenatal T; 3) prenatal T plus prenatal androgen antagonist, flutamide; 4) prenatal T plus prenatal insuli...

  6. Different critical perinatal periods and hypothalamic sites of oestradiol action in the defeminisation of luteinising hormone surge and lordosis capacity in the rat.

    Science.gov (United States)

    Sakakibara, M; Deura, C; Minabe, S; Iwata, Y; Uenoyama, Y; Maeda, K-I; Tsukamura, H

    2013-03-01

    Female rats show a gonadotrophin-releasing hormone (GnRH)/luteinising hormone (LH) surge in the presence of a preovulatory level of oestrogen, whereas males do not because of brain defeminisation during the developmental period by perinatal oestrogen converted from androgen. The present study aimed to identify the site(s) of oestrogen action and the critical period for defeminising the mechanism regulating the GnRH/LH surge. Animals given perinatal treatments, such as steroidal manipulations, brain local implantation of oestradiol (E(2) ) or administration of an NMDA antagonist, were examined for their ability to show an E(2) -induced LH surge at adulthood. Lordosis behaviour was examined to compare the mechanisms defeminising the GnRH/LH surge and sexual behaviour. A single s.c. oestradiol-benzoate administration on either the day before birth (E21), the day of birth (D0) or day 5 (D5) postpartum completely abolished the E(2) -induced LH surge at adulthood in female rats, although the same treatment did not inhibit lordosis. Perinatal castration on E21 or D0 partially rescued the E2-induced LH surge in genetically male rats, whereas castration from E21 to D5 totally rescued lordosis. Neonatal E(2) implantation in the anterior hypothalamus including the anteroventral periventricular nucleus (AVPV)/preoptic area (POA) abolished the E(2) -induced LH surge in female rats, whereas E(2) implantation in the mid and posterior hypothalamic regions had no inhibitory effect on the LH surge. Lordosis was not affected by neonatal E(2) implantation in any hypothalamic regions. In male rats, neonatal NMDA antagonist treatment rescued lordosis but not the LH surge. Taken together, these results suggest that an anterior hypothalamic region such as the AVPV/POA region is a perinatal site of oestrogen action where the GnRH/LH regulating system is defeminised to abolish the oestrogen-induced surge. The mechanism for defeminisation of the GnRH/LH surge system might be different from

  7. MicroRNA Expression Profile in Bovine Granulosa Cells of Preovulatory Dominant and Subordinate Follicles during the Late Follicular Phase of the Estrous Cycle.

    Directory of Open Access Journals (Sweden)

    Samuel Gebremedhn

    Full Text Available In bovine, ovarian follicles grow in a wave-like fashion with commonly 2 or 3 follicular waves emerging per estrous cycle. The dominant follicle of the follicular wave which coincides with the LH-surge becomes ovulatory, leaving the subordinate follicles to undergo atresia. These physiological processes are controlled by timely and spatially expressed genes and gene products, which in turn are regulated by post-transcriptional regulators. MicroRNAs, a class of short non-coding RNA molecules, are one of the important posttranscriptional regulators of genes associated with various cellular processes. Here we investigated the expression pattern of miRNAs in granulosa cells of bovine preovulatory dominant and subordinate follicles during the late follicular phase of bovine estrous cycle using Illumina miRNA deep sequencing. In addition to 11 putative novel miRNAs, a total of 315 and 323 known miRNAs were detected in preovulatory dominant and subordinate follicles, respectively. Moreover, in comparison with the subordinate follicles, a total of 64 miRNAs were found to be differentially expressed in preovulatory dominant follicles, of which 34 miRNAs including the miR-132 and miR-183 clusters were significantly enriched, and 30 miRNAs including the miR-17-92 cluster, bta-miR-409a and bta-miR-378 were significantly down regulated in preovulatory dominant follicles. In-silico pathway analysis revealed that canonical pathways related to oncogenesis, cell adhesion, cell proliferation, apoptosis and metabolism were significantly enriched by the predicted target genes of differentially expressed miRNAs. Furthermore, Luciferase reporter assay analysis showed that one of the differentially regulated miRNAs, the miR-183 cluster miRNAs, were validated to target the 3'-UTR of FOXO1 gene. Moreover FOXO1 was highly enriched in granulosa cells of subordinate follicles in comparison with the preovulatory dominant follicles demonstrating reciprocal expression pattern

  8. GnRH Neuron Activity and Pituitary Response in Estradiol-Induced vs Proestrous Luteinizing Hormone Surges in Female Mice.

    Science.gov (United States)

    Silveira, Marina A; Burger, Laura L; DeFazio, R Anthony; Wagenmaker, Elizabeth R; Moenter, Suzanne M

    2017-02-01

    During the female reproductive cycle, estradiol exerts negative and positive feedback at both the central level to alter gonadotropin-releasing hormone (GnRH) release and at the pituitary to affect response to GnRH. Many studies of the neurobiologic mechanisms underlying estradiol feedback have been done on ovariectomized, estradiol-replaced (OVX+E) mice. In this model, GnRH neuron activity depends on estradiol and time of day, increasing in estradiol-treated mice in the late afternoon, coincident with a daily luteinizing hormone (LH) surge. Amplitude of this surge appears lower than in proestrous mice, perhaps because other ovarian factors are not replaced. We hypothesized GnRH neuron activity is greater during the proestrous-preovulatory surge than the estradiol-induced surge. GnRH neuron activity was monitored by extracellular recordings from fluorescently tagged GnRH neurons in brain slices in the late afternoon from diestrous, proestrous, and OVX+E mice. Mean GnRH neuron firing rate was low on diestrus; firing rate was similarly increased in proestrous and OVX+E mice. Bursts of action potentials have been associated with hormone release in neuroendocrine systems. Examination of the patterning of action potentials revealed a shift toward longer burst duration in proestrous mice, whereas intervals between spikes were shorter in OVX+E mice. LH response to an early afternoon injection of GnRH was greater in proestrous than diestrous or OVX+E mice. These observations suggest the lower LH surge amplitude observed in the OVX+E model is likely not attributable to altered mean GnRH neuron activity, but because of reduced pituitary sensitivity, subtle shifts in action potential pattern, and/or excitation-secretion coupling in GnRH neurons. Copyright © 2017 by the Endocrine Society.

  9. PREOVULATORY FOLLICLE DEVELOPMENT IN HIGH YIELDING COWS

    Directory of Open Access Journals (Sweden)

    Radovan Tomášek

    2013-06-01

    Full Text Available The aim of the study was to examine the development of preovulatory follicles in pregnant and non-pregnant high yielding cows. The treatment by supergestran and oestrophan was used to synchronize the estrous cycle. Ovaries were monitored by transrectal ultrasonography. The linear increase of preovulatory follicles was observed in pregnant (P < 0,001 and non-pregnant (P < 0,001 cows during 8 days before ovulation. In conclusion, preovulatory follicles in pregnant and non-pregnant high yielding cows developed similarly.

  10. Effects of leptin administration on development, vascularization and function of Corpus luteum in alpacas submitted to pre-ovulatory fasting.

    Science.gov (United States)

    Norambuena, María Cecilia; Hernández, Francisca; Maureira, Jonathan; Rubilar, Carolina; Alfaro, Jorge; Silva, Gonzalo; Silva, Mauricio; Ulloa-Leal, César

    2017-07-01

    The objective of this study was to determine the effect of leptin administration on the development, vascularization and function of Corpus luteum (CL) in alpacas submitted to pre-ovulatory fasting. Fourteen alpacas were kept in fasting conditions for 72h and received five doses of o-leptin (2μg/kg e.v.; Leptin group) or saline (Control group) every 12h. Ovulation was induced with a GnRH dose (Day 0). The ovaries were examined every other day by trans-rectal ultrasonography (7.5MHz; mode B and power Doppler) from Day 0 to 13 to determine the pre-ovulatory follicle diameter and ovulation, and then to monitor CL diameter and vascularization until the regression phase. Serial blood samples were taken after GnRH treatment to determine plasma LH concentration; and every other day from Days 1 to 13 to determine plasma progesterone and leptin concentrations. The pre-ovulatory follicle and CL diameter, LH, progesterone and leptin plasma concentrations were not affected by treatment (P>0.05). The vascularization area of the CL was, nevertheless, affected by the treatment (P<0.01) with significant differences between groups at Days 3, 7 and 9 (P<0.05). The Leptin group had a larger maximum vascularization area (0.67±0.1 compared with 0.35±0.1cm 2 ; P<0.05). In addition, there was a positive correlation between CL vascularization, CL diameter and plasma progesterone. The exogenous administration of leptin during pre-ovulatory fasting increased the vascularization of the CL in alpacas in vivo. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Ultrastructure of the human preovulatory oocyte.

    Science.gov (United States)

    Szöllösi, D; Mandelbaum, J; Plachot, M; Salat-Baroux, J; Cohen, J

    1986-08-01

    The ultrastructure of preovulatory human oocyte-cumulus complexes was described after inducing maturation by clomiphene, human menopausal gonadotropin (hMG), human chorionic gonadotropin (hCG) treatment. The majority of the oocytes was at metaphase II of meiosis, with a radially orientated spindle. The oocyte surface was covered by a multitude of microvilli. Cortical granules were nonuniformly distributed along the cortex. A cytoplasmic polarization was observed. The cytoplasmic organelles were in general uniformly dispersed, with the exception of a narrow segment within which cytoplasmic membranes and mitochondria formed clusters. The spindle was usually found at the borderline between the two regions of the cytoplasm. The functional significance of this polarization is not yet known.

  12. Rhythmic expression of circadian clock genes in the preovulatory ovarian follicles of the laying hen.

    Directory of Open Access Journals (Sweden)

    Zhichao Zhang

    Full Text Available The circadian clock is reported to play a role in the ovaries in a variety of vertebrate species, including the domestic hen. However, the ovary is an organ that changes daily, and the laying hen maintains a strict follicular hierarchy. The aim of this study was to examine the spatial-temporal expression of several known canonical clock genes in the granulosa and theca layers of six hierarchy follicles. We demonstrated that the granulosa cells (GCs of the F1-F3 follicles harbored intrinsic oscillatory mechanisms in vivo. In addition, cultured granulosa cells (GCs from F1 follicles exposed to luteinizing hormone (LH synchronization displayed Per2 mRNA oscillations, whereas, the less mature GCs (F5 plus F6 displayed no circadian change in Per2 mRNA levels. Cultures containing follicle-stimulating hormone (FSH combined with LH expressed levels of Per2 mRNA that were 2.5-fold higher than those in cultures with LH or FSH alone. These results show that there is spatial specificity in the localization of clock cells in hen preovulatory follicles. In addition, our results support the hypothesis that gonadotropins provide a cue for the development of the functional cellular clock in immature GCs.

  13. LH2 Airbus studies

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The scope of work of the WP covers the 'Assessment of realistic prospects of LH 2 -usage in civil aviation', in detail: - Operational scenario for western Europe, - LH 2 cost development, - Investigations on a/c design and cryo systems, - Environmental impact of LH 2 -aircraft, - Cost estimate, - The way to a LH 2 fuelled aircraft. (orig.)

  14. Endocrine correlates of reproduction in the wolf. I. Serum progesterone, estradiol and LH during the estrous cycle

    Science.gov (United States)

    Seal, U.S.; Plotka, E.D.; Packard, J.M.; Mech, L.D.

    1979-01-01

    The estrous cycle of 10 intact female wolves, aged 8 months-8 years at the initiation of the study, was characterized in terms of vaginal smears, behavioral observations and serum concentrations of estradiol-17β, progesterone and luteinizing hormone (LH) from January through June. No estrous cycles occurred in these animals between June and December. All were housed with male wolves. Two pups and 1 adult remained anestrous during this interval. One pup and 2 adults produced litters between May 4-6. Four adults exhibited endocrine changes similar to those of the pregnant animals but no litters or signs of abortion were observed. The duration of proestrus was 15.7 ± 1.6 days (X ± SEM, n = 6), of estrus 9.0 ± 1.2 days (n = 4) and of the luteal phase 63 ± 2 days (n = 6). The duration of pregnancy was between 60-65 days. The anestrous females (86 blood samples) had 6 progesterone values between 1-2 ng/ml and the remainder below 1 ng/ml. Their estradiol-17β concentrations varied between 5-20 pg/ml. Values for LH varied between 0.1-2 ng/ml, except for 1 value above 15 ng/ml for each of the 2 anestrous pups on 12 January.The 7 estrous animals (260 samples) included 1 pup and 2 adults that delivered litters. Estradiol-17β varied between 10-20 pg/ml during proestrus, peaked at 30-70 pg/ml late in proestrus and fluctuated between 10-30 pg/ml during pregnancy or the duration of luteal activity in the nonpregnant animals. The preovulatory LH rise, 5-15 ng/ml, extended over 3 days during and immediately following the peak estradiol-17β values. An earlier elevation in LH was observed in 3 of the estrous animals. Progesterone began increasing during the LH surge and peaked 11-14 days later at 22-40 ng/ml. Progesterone concentrations greater than 3 ng/ml were maintained for 56-68 days in 6 of the 7 animals exhibiting estrus. Progesterone concentrations declined at parturition but continued to fluctuate between 0.2-3 ng/ml for 3-6 weeks.

  15. Intracerebroventricular Infusion of Vasoactive Intestinal Peptide (VIP Rescues the Luteinizing Hormone Surge in Middle-Aged Female Rats

    Directory of Open Access Journals (Sweden)

    Yan eSun

    2012-02-01

    Full Text Available Reproductive aging is characterized by delayed and attenuated luteinizing hormone (LH surges apparent in middle-aged rats. The suprachiasmatic nucleus (SCN contains the circadian clock that is responsible for the timing of diverse neuroendocrine rhythms. Electrophysiological studies suggest vasoactive intestinal peptide (VIP originating from the SCN excites gonadotropin-releasing hormone (GnRH neurons and affects daily patterns of GnRH-LH release. Age-related LH surge dysfunction correlates with reduced VIP mRNA expression in the SCN and fewer GnRH neurons with VIP contacts expressing c-fos, a marker of neuronal activation, on the day of the LH surge. To determine if age-related LH surge dysfunction reflects reduced VIP availability or altered VIP responsiveness under estradiol positive feedback conditions, we assessed the effect of intracerebroventricular (icv VIP infusion on c-fos expression in GnRH neurons and on LH release in ovariohysterectomized, hormone-primed young and middle-aged rats. Icv infusion of VIP between 1300 and 1600 h significantly advanced the time of peak LH release, increased total and peak LH release, and increased the number of GnRH neurons expressing c-fos on the day of the LH surge in middle-aged rats. Surprisingly, icv infusion of VIP in young females significantly reduced the number of GnRH neurons expressing c-fos and delayed and reduced the LH surge. These observations suggest that a critical balance of VIP signaling is required to activate GnRH neurons for an appropriately timed and robust LH surge in young and middle-aged females. Age-related LH surge changes may, in part, result from decreased availability and reduced VIP-mediated neurotransmission under estradiol positive feedback conditions.

  16. Centrifugal Compressor Surge Controlled

    Science.gov (United States)

    Skoch, Gary J.

    2003-01-01

    It shows the variation in compressor mass flow with time as the mass flow is throttled to drive the compressor into surge. Surge begins where wide variations in mass flow occur. Air injection is then turned on to bring about a recovery from the initial surge condition and stabilize the compressor. The throttle is closed further until surge is again initiated. Air injection is increased to again recover from the surge condition and stabilize the compressor.

  17. Cortisol Interferes with the Estradiol-Induced Surge of Luteinizing Hormone in the Ewe1

    Science.gov (United States)

    Wagenmaker, Elizabeth R.; Breen, Kellie M.; Oakley, Amy E.; Pierce, Bree N.; Tilbrook, Alan J.; Turner, Anne I.; Karsch, Fred J.

    2008-01-01

    Two experiments were conducted to test the hypothesis that cortisol interferes with the positive feedback action of estradiol that induces the luteinizing hormone (LH) surge. Ovariectomized sheep were treated sequentially with progesterone and estradiol to create artificial estrous cycles. Cortisol or vehicle (saline) was infused from 2 h before the estradiol stimulus through the time of the anticipated LH surge in the artificial follicular phase of two successive cycles. The plasma cortisol increment produced by infusion was ∼1.5 times greater than maximal concentrations seen during infusion of endotoxin, which is a model of immune/inflammatory stress. In experiment 1, half of the ewes received vehicle in the first cycle and cortisol in the second; the others were treated in reverse order. All ewes responded with an LH surge. Cortisol delayed the LH surge and reduced its amplitude, but both effects were observed only in the second cycle. Experiment 2 was modified to provide better control for a cycle effect. Four treatment sequences were tested (cycle 1-cycle 2): vehicle-vehicle, cortisol-cortisol, vehicle-cortisol, cortisol-vehicle. Again, cortisol delayed but did not block the LH surge, and this delay occurred in both cycles. Thus, an elevation in plasma cortisol can interfere with the positive feedback action of estradiol by delaying and attenuating the LH surge. PMID:19056703

  18. Differential Effects of Continuous Exposure to the Investigational Metastin/Kisspeptin Analog TAK-683 on Pulsatile and Surge Mode Secretion of Luteinizing Hormone in Ovariectomized Goats

    Science.gov (United States)

    TANAKA, Tomomi; OHKURA, Satoshi; WAKABAYASHI, Yoshihiro; KUROIWA, Takenobu; NAGAI, Kiyosuke; ENDO, Natsumi; TANAKA, Akira; MATSUI, Hisanori; KUSAKA, Masami; OKAMURA, Hiroaki

    2013-01-01

    Abstract The aim of the present study was to determine if the estradiol-induced luteinizing hormone (LH) surge is influenced by the constant exposure to TAK-683, an investigational metastin/kisspeptin analog, that had been established to depress the pulsatile gonadotropin-releasing hormone (GnRH) and LH secretion in goats. Ovariectomized goats subcutaneously received TAK-683 (TAK-683 group, n=6) or vehicle (control group, n=6) constantly via subcutaneous implantation of an osmotic pump. Five days after the start of the treatment, estradiol was infused intravenously in both groups to evaluate the effects on the LH surge. Blood samples were collected at 6-min intervals for 4 h prior to the initiation of either the TAK-683 treatment or the estradiol infusion, to determine the profiles of pulsatile LH secretion. They were also collected at 2-h intervals from –4 h to 32 h after the start of estradiol infusion for analysis of LH surges. The frequency and mean concentrations of LH pulses in the TAK-683 group were remarkably suppressed 5 days after the start of TAK-683 treatment compared with those of the control group (P<0.05). On the other hand, a clear LH surge was observed in all animals of both groups. There were no significant differences in the LH concentrations for surge peak and the peak time of the LH surge between the TAK-683 and control groups. These findings suggest that the effects of continuous exposure to kisspeptin or its analog on the mechanism(s) that regulates the pulsatile and surge mode secretion of GnRH/LH are different in goats. PMID:24047956

  19. Storm surge climatology report

    OpenAIRE

    Horsburgh, Kevin; Williams, Joanne; Cussack, Caroline

    2017-01-01

    Any increase in flood frequency or severity due to sea level rise or changes in storminess would adversely impact society. It is crucial to understand the physical drivers of extreme storm surges to have confidence in the datasets used for extreme sea level statistics. We will refine and improve methods to the estimation of extreme sea levels around Europe and more widely. We will do so by developing a comprehensive world picture of storm surge distribution (including extremes) for both tropi...

  20. release of lh in ewes treated with progestogen and oestrogen during

    African Journals Online (AJOL)

    ly in ewes after the use of progestogens to synchronise oestrus or to ... Two hours later a blood ... which received progesterone exhibited neither oestrus nor an LH surge ... been too short (Radford et al., 1970) or the fall in proges- terone titre ...

  1. Relationships between the luteinizing hormone surge and other characteristics of the menstrual cycle in normally ovulating women.

    Science.gov (United States)

    Direito, Ana; Bailly, Sébastien; Mariani, Aude; Ecochard, René

    2013-01-01

    To describe the LH surge variants in ovulating women and analyze their relationship with the day of ovulation and other hormone levels. Secondary analysis of a prospective cohort observational study. Eight natural family planning clinics. Normally fertile women (n = 107) over 283 cycles. Women collected daily first morning urine, charted basal body temperature and cervical mucus discharge, and underwent serial ovarian ultrasound. Urinary LH, FSH, estrone-3-glucuronide (E3G), pregnanediol-3α-glucuronide (PDG), and day of ovulation by ultrasound (US-DO). Individual LH surges were extremely variable in configuration, amplitude, and duration. The study also showed that LH surges marked by several peaks were associated with statistically significant smaller follicle sizes before rupture and lower LH level on the day of ovulation. LH surges lasting >3 days after ovulation were associated with a lower E3G before ovulation, a smaller corpus luteum 2 days after ovulation, and a lower PDG value during the first 4 days after ovulation. In clinical practice, LH profiles should be compared with the range of profiles observed in normally fertile cycles, not with the mean profile. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  2. Ovarian Follicular Dynamics During the Luteinizing Hormone Surge in the Bottlenose Dolphin (Tursiops truncatus)

    OpenAIRE

    Muraco, Holley; Clough, Pat; Teets, Valerie; Arn, Dennis; Muraco, Mike

    2010-01-01

    Characterizing the relationship between ovarian follicular dynamics and the luteinizing hormone (LH) surge in the bottlenose dolphin (Tursiops truncatus) requires detailed daily monitoring due to the transitory nature of LH and ovulation. Utilizing conditioned dolphins and non-invasive sampling techniques, such as urine collection and trans-abdominal ultrasound exams, provides the means to accurately monitor these fleeting processes. Urine samples and ultrasound exams used in this study were ...

  3. Testosterone stimulates progesterone production and STAR, P450 cholesterol side-chain cleavage and LH receptor mRNAs expression in hen (Gallus domesticus) granulosa cells.

    Science.gov (United States)

    Rangel, P L; Rodríguez, A; Rojas, S; Sharp, P J; Gutierrez, C G

    2009-12-01

    The chicken ovary is organized into a hierarchy of yellow yolky follicles that ovulate on successive days. Active or passive immunization of laying hens against testosterone blocks ovulation without affecting follicle development. Testosterone may play a role in pre-ovulatory follicle maturation by stimulating granulosa progesterone production. We assessed whether this stimulus is dose-related and depends on the maturity of the donor follicle, and if it does so by stimulating granulosa cell STAR, P450 cholesterol side-chain cleavage (P450scc), and LH receptor (LHCGR) mRNAs expression. Progesterone production by granulosa cells from F1, F3, and F4 follicles, cultured for 3 h without testosterone was greater in cells collected 11-14 h than 1-4 h after ovulation. These differences in progesterone production were less pronounced after granulosa cells had been cultured for 24 h. Culture of granulosa cells for 3 or 24 h with testosterone (1-100 ng/ml) stimulated progesterone production in cells collected from F4, F3, or F1 follicles 1-4, or 11-14 h after ovulation. Testosterone (0-4000 ng/ml) alone or in combination with LH (0-100 ng/ml) increased progesterone production by F1 granulosa cells, collected 1-4 and 11-14 h after ovulation and cultured for 3 h. Finally, testosterone (10 or 100 ng/ml) increased STAR, P450scc, and LHCGR mRNAs, when added to 3 h cultures of F1 granulosa cells. In conclusion, testosterone stimulates granulosa cell progesterone production in hen pre-ovulatory hierarchical follicles irrespective of maturational state, acting alone or additively with LH. We propose that testosterone promotes granulosa cell maturation to facilitate the pre-ovulatory release of LH.

  4. Effect of 3,3',5-triiodothyronine and 3,5-diiodothyronine on progesterone production, cAMP synthesis, and mRNA expression of STAR, CYP11A1, and HSD3B genes in granulosa layer of chicken preovulatory follicles.

    Science.gov (United States)

    Sechman, A; Pawlowska, K; Hrabia, A

    2011-10-01

    In vitro studies were performed to assess whether stimulatory effects of triiodothyronine (T3) on progesterone (P4) production in a granulosa layer (GL) of chicken preovulatory follicles are associated with 3',5'-cyclic adenosine monophosphate (cAMP) synthesis and mRNA expression of STAR protein, CYP11A1, and HSD3B. Effects of 3,5-diiodothyronine (3,5-T2) on steroidogenic function in these follicles were also investigated. The GL of F3 to F1 follicles was incubated in medium supplemented with T3 or 3,5-T2, LH, or forskolin (F), and a combination of each iodothyronine with LH or F. Levels of P4 and cAMP in culture media were determined by RIA. Expression of genes involved in P4 synthesis (ie, STAR protein, CYP11A1, and HSD3B) in the GL of F3 to F1 follicles incubated in medium with T3 or 3,5-T2 and their combination with LH was performed by real-time PCR. Triiodothyronine increased basal and LH- and F-stimulated P4 secretion by preovulatory follicles. The 3,5-T2 elevated P4 synthesis by F3, had no effect on F2 follicles, and diminished P4 production by the GL of F1 follicles. It had no effect on LH-stimulated P4 production; however, it augmented F-stimulated P4 production by F2 and F1 follicles. Although T3 did not affect basal and F-stimulated cAMP synthesis by the GL of preovulatory follicles, it increased LH-stimulated synthesis of this nucleotide. However, 3,5-T2 elevated F-stimulated cAMP synthesis in F3 and F2 follicles; it did not change basal and LH-stimulated cAMP production. Triiodothyronine decreased basal STAR and CYP11A1 mRNAs in F3 follicles, increased them in F1 follicles, and elevated HSD3B mRNA levels in F1 follicles. Triiodothyronine augmented LH-stimulated STAR, CYP11A1, and HSD3B mRNA levels in F2 and CYP11A1 in F1 follicles. However, T3 decreased LH-stimulated STAR and HSD3B mRNA levels in F1 follicles. The 3,5-T2 did not affect basal STAR and CYP11A1 mRNA expression in all investigated follicles; however, it decreased LH-stimulated STAR

  5. LH2 airport requirements study

    Science.gov (United States)

    Brewer, G. D. (Editor)

    1976-01-01

    A preliminary assessment of the facilities and equipment which will be required at a representative airport is provided so liquid hydrogen LH2 can be used as fuel in long range transport aircraft in 1995-2000. A complete facility was conceptually designed, sized to meet the projected air traffic requirement. The facility includes the liquefaction plant, LH2, storage capability, and LH2 fuel handling system. The requirements for ground support and maintenance for the LH2 fueled aircraft were analyzed. An estimate was made of capital and operating costs which might be expected for the facility. Recommendations were made for design modifications to the reference aircraft, reflecting results of the analysis of airport fuel handling requirements, and for a program of additional technology development for air terminal related items.

  6. The influence of elevated preovulatory estradiol on apoptosis in the trophectoderm of day 16 bovine conceptuses

    Science.gov (United States)

    Preovulatory estradiol impacts follicular growth, oocyte maturation, sperm transport, uterine environment, and embryo survival/development. It has also been reported that cows in standing estrus within 24 hours of fixed-time AI have greater pregnancy success compared to cows that do not exhibit stan...

  7. Effects of a preovulatory single low dose of mifepristone on ovarian function

    NARCIS (Netherlands)

    van der Stege, Jolande G.; Pahl-van Beest, Elske H.; Beerthuizen, Rob J. C. M.; van Lunsen, Rik H. W.; Scholten, Piet C.; Bogchelman, Dick H.

    Objectives To investigate the effect of a single low dose of mifepristone on ovarian function, when administered in the preovulatory period. Methods Healthy women with regular menstrual cycles were studied during two consecutive menstrual cycles. Either mifepristone or placebo was given in a

  8. (LH) secretion in fasted prepubertal ewes

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-01-10

    Jan 10, 2012 ... decreased luteinizing hormone (LH) secretion in fasted prepubertal ewes .... kisspeptin-10 injection could restore the baseline levels of. LH changed by ..... Terasawa E (2005). Role of GABA in the mechanism of the onset of.

  9. Radioimmunoassay of pituitary LH in fetal rabbit

    International Nuclear Information System (INIS)

    Veyssiere, Georges; Berger, Michel; Jean-Faucher, Christiane; Turckheim, Marc de; Jean, Claude

    1981-01-01

    LH was measured by radioimmunology from the 18th day of gestation to birth in 318 male and female pituitary glands. LH was first detectable in the pituitary of 19 day old fetuses of both sexes. In both sexes pituitary LH levels increased from the 18th to the 31st day of gestation with a marked acceleration from the 24th day. LH pituitary levels were not sex-dependent [fr

  10. Surge-damping vacuum valve

    International Nuclear Information System (INIS)

    Bullock, J.C.; Kelley, B.E.

    1977-01-01

    A valve for damping out flow surges in a vacuum system is described. The surge-damping mechanism consists of a slotted, spring-loaded disk adjacent to the valve's vacuum port (the flow passage to the vacuum roughing pump). Under flow surge conditions, the differential pressure forces the disk into a sealing engagement with the vacuum port, thereby restricting the gas flow path to narrow slots in the disk's periphery. The increased flow damps out the flow surge. When pressure is equalized on both sides of the valve, the spring load moves the disk away from the port to restore full flow conductance through the valve

  11. Circadian rhythm disruption by a novel running wheel: Roles of exercise and arousal in blockade of the luteinizing hormone surge

    Science.gov (United States)

    Duncan, Marilyn J.; Franklin, Kathleen M.; Peng, Xiaoli; Yun, Christopher; Legan, Sandra J.

    2014-01-01

    Exposure of proestrous Syrian hamsters to a new room, cage, and novel running wheel blocks the luteinizing hormone (LH) surge until the next day in ~75% of hamsters (Legan et al, 2010) [1]. The studies described here tested the hypotheses that 1) exercise and/or 2) orexinergic neurotransmission mediate novel wheel blockade of the LH surge and circadian phase advances. Female hamsters were exposed to a 14L:10D photoperiod and activity rhythms were monitored with infra-red detectors. In Expt. 1, to test the effect of exercise, hamsters received jugular cannulae and on the next day, proestrus (Day 1), shortly before zeitgeber time 5 (ZT 5, 7 hours before lights-off) the hamsters were transported to the laboratory. After obtaining a blood sample at ZT 5, the hamsters were transferred to a new cage with a novel wheel that was either freely rotating (unlocked), or locked until ZT 9, and exposed to constant darkness (DD). Blood samples were collected hourly for 2 days from ZT 5–11 under red light for determination of plasma LH levels by radioimmunoassay. Running rhythms were monitored continuously for the next 10–14 days. The locked wheels were as effective as unlocked wheels in blocking LH surges (no Day 1 LH surge in 6/9 versus 8/8 hamsters, P>0.05) and phase advances in the activity rhythms did not differ between the groups (P= 0.28), suggesting that intense exercise is not essential for novel wheel blockade and phase advance of the proestrous LH surge. Expt. 2 tested whether orexin neurotransmission is essential for these effects. Hamsters were treated the same as in Expt. 1 except they were injected (i.p.) at ZT 4.5 and 5 with either the orexin 1 receptor antagonist SB334867 (15 mg/kg per injection) or vehicle (25% DMSO in 2-hydroxypropyl-beta-cyclodextrin (HCD). SB-334867 inhibited novel wheel blockade of the LH surge (surges blocked in 2/6 SB334867-injected animals versus 16/18 vehicle-injected animals, Pwheel running and circadian phase shifts, indicating that

  12. Serum LH-RF and LH levels after synthetic LH-RF administration in man as measured by radioimmunoassays

    International Nuclear Information System (INIS)

    Shiina, Masaki; Makino, Tsunehisa; Nakamura, Yukio; Iizuka, Rihachi

    1975-01-01

    Using a radioimmunoassay (RIA) which is sensitive and highly specific to lutenizing hormone releasing factors (LRF, LH-RF), diminution of an exogeously administered synthetic LH-RF in the blood and the movement of LH released into the blood from the anterior lobe of hypopysis were examined on healthy adult males. The blood LH-RF level after an intravenous administration of 200 μg of synthetic LH-RF reached a maximum (mean, 35.0 ng/ml serum) 2.5 minutes after administration, followed by a rapid decrease, and was as low as 1.0 ng/ml serum 30 minutes after administration. The diminution of the exogenous LH-RF from the blood was rapidest 2.5-15 minutes after administration (t1/2=3.9 minutes) and slowest (t1/2=7.9 minutes) 15-30 minutes after administration. On the other hand, when 200 μg of the synthetic LH-RF was administered intramuscularly, LH-RF appeared only slightly in the blood 2.5 minutes after administration, and the maximum level (10 minutes after administration) was only 1.6 ng/ml serum. It diminished from the blood drawing lenient curve. The blood LH level continued to rise significantly starting 5 minutes after administration of 200 μg of the synthetic LH-RF both in intravenous and intramuscular cases, showing hardly any differences between them. The blood endogenous LH-RF level prior to the synthetic LH-RF administration was below the measurable sensitivity (10 pg/tupe). (Mukohata, S.)

  13. Electrodynamics properties of auroral surges

    International Nuclear Information System (INIS)

    Robinson, R.M.; Vondrak, R.R.

    1990-01-01

    The incoherent scatter radar technique provides an excellent means to study the ionization and electric fields associated with auroral precipitation events. One of the most intense and dynamic auroral events is the so-called surge or breakup aurora that accompanies auroral substorms. For their purposes they define a surge as a transient intensification of auroral precipitation that occurs simultaneously with a pronounced negative bay in the ground magnetometer data. They present data obtained during five such events in 1980 and 1981. Prior to the surge, auroral forms move equatorward, develop ray structure, and intensify. The surge is identified by an apparent poleward motion of the aurora producing aurorally associated ionization that extends over several hundred kilometers in latitude. The presurge auroral forms are embedded in a region of northward electric field. The auroral forms that comprise the surge span a region within which the meridional electric field is small and at times southward. A westward electric field is often but not always present within the surge. The behavior of the westward electric field is significantly different from the north-south field, in that sharp spatial gradients are absent even in very disturbed conditions. Although the westward Hall currents are mostly responsible for the negative bays that accompany the surge, at times the westward Pedersen current sustained by the westward electric field can be important. Sudden variations in the H component of the ground magnetogram can be caused by motions of the aurora or by temporal variations in the fields or conductivities. They present a model that simulates the observed changes in electric field and precipitation that accompany surges. The perturbation in the electric field produced by the surge is simulated by adding negative potential in regions of intense precipitation

  14. Toward an integrated storm surge application: ESA Storm Surge project

    Science.gov (United States)

    Lee, Boram; Donlon, Craig; Arino, Olivier

    2010-05-01

    Storm surges and their associated coastal inundation are major coastal marine hazards, both in tropical and extra-tropical areas. As sea level rises due to climate change, the impact of storm surges and associated extreme flooding may increase in low-lying countries and harbour cities. Of the 33 world cities predicted to have at least 8 million people by 2015, at least 21 of them are coastal including 8 of the 10 largest. They are highly vulnerable to coastal hazards including storm surges. Coastal inundation forecasting and warning systems depend on the crosscutting cooperation of different scientific disciplines and user communities. An integrated approach to storm surge, wave, sea-level and flood forecasting offers an optimal strategy for building improved operational forecasts and warnings capability for coastal inundation. The Earth Observation (EO) information from satellites has demonstrated high potential to enhanced coastal hazard monitoring, analysis, and forecasting; the GOCE geoid data can help calculating accurate positions of tide gauge stations within the GLOSS network. ASAR images has demonstrated usefulness in analysing hydrological situation in coastal zones with timely manner, when hazardous events occur. Wind speed and direction, which is the key parameters for storm surge forecasting and hindcasting, can be derived by using scatterometer data. The current issue is, although great deal of useful EO information and application tools exist, that sufficient user information on EO data availability is missing and that easy access supported by user applications and documentation is highly required. Clear documentation on the user requirements in support of improved storm surge forecasting and risk assessment is also needed at the present. The paper primarily addresses the requirements for data, models/technologies, and operational skills, based on the results from the recent Scientific and Technical Symposium on Storm Surges (www

  15. Progesterone production requires activation of caspase-3 in preovulatory granulosa cells in a serum starvation model.

    Science.gov (United States)

    An, Li-Sha; Yuan, Xiao-Hua; Hu, Ying; Shi, Zi-Yun; Liu, Xiao-Qin; Qin, Li; Wu, Gui-Qing; Han, Wei; Wang, Ya-Qin; Ma, Xu

    2012-11-01

    Granulosa cells proliferate, differentiate, and undergo apoptosis throughout follicular development. Previous studies have demonstrated that stimulation of progesterone production is accompanied by caspase-3 activation. Moreover, we previously reported that arsenic enhanced caspase-3 activity coupled with progesterone production. Inhibition of caspase-3 activity can significantly inhibit progesterone production induced by arsenic or follicle-stimulating hormone (FSH). Here, we report that serum starvation induces caspase-3 activation coupled with augmentation of progesterone production. Serum starvation also increased the levels of cytochrome P450 cholesterol side chain cleavage enzyme (P450scc) and steroidogenic acute regulatory (StAR) protein, both of which may contribute to progesterone synthesis in preovulatory granulosa cells. Inhibition of caspase-3 activity resulted in a decrease in progesterone production. Deactivation of caspase-3 activity by caspase-3 specific inhibitor also resulted in decreases in P450scc and StAR expression, which may partly contribute to the observed decrease in progesterone production. Our study demonstrates for the first time that progesterone production in preovulatory granulosa cells is required for caspase-3 activation in a serum starvation model. Inhibition of caspase-3 activity can result in decreased expression of the steroidogenic proteins P450scc and StAR. Our work provides further details on the relationship between caspase-3 activation and steroidogenesis and indicates that caspase-3 plays a critical role in progesterone production by granulosa cells. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Application of ovine luteinizing hormone (LH) radioimmunoassay in the quantitation of LH in different mammalian species

    International Nuclear Information System (INIS)

    Millar, R.P.; Aehnelt, C.

    1977-01-01

    A sensitive double antibody radioimmunoassay has been developed for measuring luteinizing hormone (LH) in various African mammalian species, using rabbit anti-ovine LH serum (GDN 15) and radioiodinated rat LH or ovine LH. Serum and pituitary homogenates from some African mammals (hyrax, reedbuck, sable, impala, tsessebe, thar, spring-hare, ground squirrel and cheetah, as well as the domestic sheep, cow and horse and laboratory rat and hamster) produced displacement curves parallel to that of the ovine LH standards. The specificity of the assay was examined in detail for one species, the rock hyrax. Radioimmunoassay and bioassay estimates of LH in hyrax pituitaries containing widely differing quantities of pituitary hormones were similar. In sexually active male hyrax mean plasma LH was 12.1 ng/ml and pituitary LH 194 μg/gland, but in sexually quiescent hyrax mean plasma LH was 2.4 ng/ml and mean pituitary LH 76 μg/gland. Intravenous injection of 10 μg of luteinizing hormone releasing hormone increased mean LH levels in hyrax from 0.9 ng/ml to 23.2 ng/ml by 30 min. Conversely, im injection of 250 μg testosterone induced a fall in LH levels in male hyrax from 1.7 ng/ml to 0.7 ng/ml 6 h after administration. Although the specificity of the assay for quantitating plasma LH in other species was not categorically established, there was a good correlation between plasma LH concentration and reproductive state in the bontebok, impala, spring-hare, thar, cheetah, domestic horse and laboratory rat, suggesting the potential use of the antiserum in quantitating LH in a variety of mammalian species

  17. Elevated basal progesterone levels are associated with increased preovulatory progesterone rise but not with higher pregnancy rates in ICSI cycles with GnRH antagonists.

    Science.gov (United States)

    Mutlu, Mehmet Firat; Erdem, Mehmet; Mutlu, Ilknur; Bulut, Berk; Erdem, Ahmet

    2017-09-01

    To ascertain the association between basal progesterone (P) levels and the occurrence of preovulatory progesterone rise (PPR) and clinical pregnancy rates (CPRs) in ICSI cycles with GnRH antagonists. Serum P levels of 464 patients were measured on day 2 and day of hCG of cycles. Cycles with basal P levels>1.6ng/mL were cancelled. All embryos were cryopreserved in cycles with P levels≥2ng/mL on the day of hCG. The primary outcome measures were the incidence of PPR (P>1.5ng/mL) and CPR with regard to basal P. Basal P levels were significantly higher in cycles with PPR than in those without PPR (0.63±0.31 vs. 0.48±0.28ng/mL). Area under the curve for basal P according to ROC analysis to discriminate between elevated and normal P levels on the day of hCG was 0.65 (0.58-0.71 95% CI, pcycles with and without PPR was 0.65ng/mL. Cycles with basal P levels above 0.65ng/mL had a significantly higher incidence of PPR (30.9% vs. 13.5%) but similar clinical and cumulative pregnancy rates (38.8% vs. 31.1% and 41.7% vs. 32.6%, respectively) in comparison to cycles with basal P levels below 0.65ng/mL. In multivariate regression analysis, basal P levels, LH level on the first day of antagonist administration, and estradiol levels on the day of hCG trigger were the variables that predicted PPR. Basal P levels were associated with increased incidence of PPR but not with CPR. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Emergency department surge: models and practical implications.

    Science.gov (United States)

    Nager, Alan L; Khanna, Kajal

    2009-08-01

    Emergency Department crowding has long been described. Despite the daily challenges of managing emergency department volume and acuity; a surge response during a disaster entails even greater challenges including collaboration, intervention, and resourcefulness to effectively carry out pediatric disaster management. Understanding surge and how to respond with appropriate planning will lead to success. To achieve this, we sought to analyze models of surge; review regional and national data outlining surge challenges and factors that impact surge; and to outline potential solutions. We conducted a systemic review and included articles and documents that best described the theoretical and practical basis of surge response. We organized the systematic review according to the following questions: What are the elements and models that are delineated by the concept of surge? What is the basis for surge response based on regional and national published sources? What are the broad global solutions? What are the major lessons observed that will impact effective surge capacity? Multiple models of surge are described including public health, facility-based and community-based; a 6-tiered response system; and intrinsic or extrinsic surge capacity. In addition, essential components (4 S's of surge response) are described along with regional and national data outlining surge challenges, impacting factors, global solutions, and lesions observed. There are numerous shortcomings regionally and nationally affecting our ability to provide an effective and coordinated surge response. Planning, education, and training will lead to an effective pediatric disaster management response.

  19. Effect of vitamin E on preovulatory stage irradiated female mouse expressed as chromosomal abnormalities in generated embryos

    International Nuclear Information System (INIS)

    Salimi, M.; Mozdarani, H.

    2006-01-01

    The present study has been carried out to investigate the effects of preovulatory stage gamma-irradiation of female mice in the absence or presence of vitamin E on numerical chromosome abnormalities in 8-cell embryos after mating with non- irradiated males. Materials and Methods: The 8-11 weeks adult female NMRl mice were whole body irradiated at preovulatory stage (post PMSG injection and about 12-18 hours before Injecting HCG) with 4 Gy gamma-rays generated from a cobalt-60 source alone or in combination with 200 IU/kg vitamin E, intraperitoneally administered one hour prior to irradiation. Soon after HCG injection super ovulated irradiated females were mated with non-irradiated males. About 68-h post coitus (p.c), 8-cell embryos were flushed from the oviducts of pregnant mice and were fixed on slides using standard methods in order to screen for metaphase spreads and numerical chromosome abnormalities. Results: In control embryos, 8% of metaphase plates were aneuploidy whereas in preovulatory stage irradiated female mice, about 50% of metaphase plates of embryos showed numerical chromosome aberrations (P nd meiotic division. Reduction of the frequency of chromosome aberrations in the presence of vitamin E is probably due to antioxidant effects of this vitamin, and scavenging free radicals induced by gamma-rays in mice oocytes' environment

  20. Direct Visualization of Exciton Reequilibration in the LH1 and LH2 Complexes of Rhodobacter sphaeroides by Multipulse Spectroscopy

    NARCIS (Netherlands)

    Cohen Stuart, T.A.; Vengris, M.; Novoderezhkin, V.I.; Cogdell, R.J.; Hunter, C.N.; van Grondelle, R.

    2011-01-01

    The dynamics of the excited states of the light-harvesting complexes LH1 and LH2 of Rhodobacter sphaeroides are governed, mainly, by the excitonic nature of these ring-systems. In a pump-dump-probe experiment, the first pulse promotes LH1 or LH2 to its excited state and the second pulse dumps a

  1. Maternal postpartum learned helplessness (LH) affects maternal care by dams and responses to the LH test in adolescent offspring.

    Science.gov (United States)

    Kurata, Akiko; Morinobu, Shigeru; Fuchikami, Manabu; Yamamoto, Shigeto; Yamawaki, Shigeto

    2009-06-01

    It is known that the early environment affects the mental development of rodent and human offspring. However, it is not known specifically whether a postpartum depressive state influences the depressive state in offspring. Using learned helplessness (LH) in rats as an animal model of depression, we examined the influence of maternal postpartum LH on responses to the LH test of offspring. Dam rats were judged as LH or non-helpless (nLH) on postnatal days (PN) 2-3, and maternal behavior was recorded during PN2-14. On PN 45-46, offspring were subjected to the LH test. Plasma corticosterone (CORT) levels, hippocampal levels of glucocorticoid receptor (GR) and brain-derived neurotrophic factor (BDNF) mRNA were measured before and after the LH test in offspring. Active nursing in LH dams was significantly lower than that in nLH dams. Susceptibility to LH in the offspring of LH dams was significantly higher than in those of nLH dams, and was negatively correlated with active nursing by LH dams. The GR mRNA levels before and after the LH test were lower in the offspring of LH dams than in those of nLH dams, and the reduced basal GR mRNA and protein might have resulted in the higher CORT response after the LH test. There was no significant difference in BDNF mRNA in the offspring of LH and nLH dams. These findings suggest that early postpartum LH decreased active nursing and increased depression-like behavior in the adolescent offspring via dysfunction of the hypothalamic-pituitary-adrenal axis.

  2. Three-dimensional culture of buffalo granulosa cells in hanging drop mimics the preovulatory follicle stage.

    Science.gov (United States)

    Yadav, Monica; Agrawal, Himanshu; Pandey, Mamta; Singh, Dheer; Onteru, Suneel K

    2018-03-01

    Granulosa cell (GC) culture models mimicking the intrafollicular environment are limited. Such models have a great potential in reproductive toxicity studies. The buffalo, a monovulatory species like humans, could be a better model than polyovulatory rodents. Therefore, we targeted the development and characterization of three-dimensional (3D) culture systems for buffalo GCs. The GCs from small ovarian follicles (SF) maintained the CYP19 gene expression for 144 hr in a 2D culture system. Hence, GCs from SF were cultured directly in 3D using hanging drop and Poly-([2-hydroxyethyl methacrylate]) (polyHEMA) methods in the DMEM media containing 1 ng/ml FSH and 10 ng/ml IGF-1 for 144 hr. The expression profile of nine GC-specific transcripts; CYP19, TNFAIP6, AMH, PTI, NR4A1, FSHR, RUNX, LHR, and COX2/PTGS2; revealed that 3D-spheroids developed in hanging drop method maintained the GC phenotype of preovulatory follicles. Therefore, hanging drop method is a best method for culturing GCs to mimic the intrafollicular environment. © 2017 Wiley Periodicals, Inc.

  3. Utrogestan as an effective oral alternative for preventing premature luteinizing hormone surges in women undergoing controlled ovarian hyperstimulation for in vitro fertilization.

    Science.gov (United States)

    Zhu, Xiuxian; Zhang, Xiaole; Fu, Yonglun

    2015-05-01

    A major cause of cycle cancellation during controlled ovarian hyperstimulation (COH) in women undergoing in vitro fertilization (IVF) is the occurrence of premature luteinizing hormone (LH) surges. Steroidal preparations can modulate the secretion of gonadotropins (Gn); however, few studies using progesterone to inhibit the premature LH surges in COH have been published. The purpose of the study was to evaluate the oral delivery of progesterone soft capsules (Utrogestan) to prevent LH surges from the follicular phase and to compare cycle characteristics as well as to evaluate pregnancy outcomes in subsequent frozen-thawed embryo transfer (FET) cycles. A total of 374 patients were enrolled in this retrospective study, among which 187 patients were simultaneously administered Utrogestan and human menopausal gonadotrophin (hMG) from cycle day 3 until the trigger day. A short protocol including 187 controls with comparable age, body mass index (BMI), infertility duration, and antral follicle count was also used. GnRH agonist (0.1 mg) or hCG (3000 IU) was used for a trigger when the dominant follicles matured. Viable embryos were cryopreserved for later transfer in both groups. The primary outcome was the number of oocytes retrieved. The secondary outcomes included the number of mature oocytes, incidence of premature LH surge, and clinical pregnancy outcomes from FET cycles. Consistent LH suppression was achieved during COH, with a range of 0.07 to 8.9 IU/L, and no premature LH surge was detected. The number of oocytes retrieved in the Utrogestan and hMG protocol was comparable with that in the short protocol (10.92 ± 5.74 vs 10.6 ± 6.22, P > 0.05), and the dose of hMG was higher than that used in the short protocol (1884.22 ± 439.47 IU vs 1446.26 ± 550.48 IU, P effective oral alternative for preventing premature LH surges in women undergoing COH, which will help to establish a convenient user regimen in combination with FET.

  4. Mobility of pyroclastic flows and surges at the Soufriere Hills Volcano, Montserrat

    Science.gov (United States)

    Calder, E.S.; Cole, P.D.; Dade, W.B.; Druitt, T.H.; Hoblitt, R.P.; Huppert, H.E.; Ritchie, L.; Sparks, R.S.J.; Young, S.R.

    1999-01-01

    The Soufriere Hills Volcano on Montserrat has produced avalanche-like pyroclastic flows formed by collapse of the unstable lava dome or explosive activity. Pyroclastic flows associated with dome collapse generate overlying dilute surges which detach from and travel beyond their parent flows. The largest surges partially transform by rapid sedimentation into dense secondary pyroclastic flows that pose significant hazards to distal areas. Different kinds of pyroclastic density currents display contrasting mobilities indicated by ratios of total height of fall H, run-out distance L, area inundated A and volume transported V. Dome-collapse flow mobilities (characterised by either L/H or A/V 2/3) resemble those of terrestrial and extraterrestrial cold-rockfalls (Dade and Huppert, 1998). In contrast, fountain-fed pumice flows and fine-grained, secondary pyroclastic flows travel slower but, for comparable initial volumes and heights, can inundate greater areas.

  5. Melatonin and LH secretion patterns in pubertal boys

    International Nuclear Information System (INIS)

    Fevre, M.; Boyar, R.M.; Rollag, M.D.

    1979-01-01

    Plasma melatonin and LH were measured at 20 minute intervals for 24 hours in four normal pubertal boys. All four subjects showed a significant augmentation of LH and melatonin during nocturnal sleep. There was also a significant correlation between the LH and melatonin levels (p [fr

  6. Influence of bovine LH tracer quality on levels of LH in GnRH-treated cows

    International Nuclear Information System (INIS)

    Madej, A.; Hallin, P.; Madej, M.; Seguin, B.; Edqvist, L.E.

    1989-01-01

    Chromatography of 125I-bovine LH (LER-1716-2 and USDA-I-1) by means of anion exchange high performance liquid chromatography (HPLC) revealed two main peaks of radioactivity regardless as to whether or not the tracer was initially purified on cellulose CF11. The content of radioactivity in the first peak tended to increase as the storage time of the bLH preparation, either before or after iodination, increased. The first peak of radioactivity after HPLC fractionation either with or without cellulose adsorption consisted of material with low binding ability to bLH antiserum (6.9% +/- 0.5 and 13.0% +/- 1.0, respectively) and high binding ability to ovine LH alpha antiserum (51.0% +/- 2.7 and 35.2% +/- 3.6, respectively). The average ratio of alpha-subunit immuno-reactivity to 125I-bLH immunoreactivity in this material was 7.4 +/- 0.1 and 2.7 +/- 0.2, respectively (P less than 0.001). Peaks in 125I-bLH radioactivity and 125I-bLH immunoreactivity had different elution times. Radioimmunoassays with tracers obtained from fractions derived from the first radioactive peak after HPLC chromatography (i.e. 125I-bLH-LER-1716-2) both with and without cellulose adsorption, yielded significantly lower mean plasma LH levels in GnRH-treated cows compared with the control tracer routinely purified only on cellulose CF11 (e.g. 5.7 vs. 8.2 micrograms/; 4.6 vs. 8.2 micrograms/l). Plasma LH levels in GnRH-treated cows were significantly (P less than 0.001) lower as measured by radioimmunoassay utilizing 125I-USDA-blH-I-1 tracers than by radioimmunoassays utilizing 125I-blH-LER-1716-2 tracers (i.e. either Y = 0.17 + 0.75X or Y = 1.18 + 0.60X)

  7. Serum LH and FSH Responses to Synthetic LH-RH in Normal Infants, Children and Patients With Turner's Syndrome

    Science.gov (United States)

    Suwa, Seizo; And Others

    1974-01-01

    Effects of luteinizing hormone-releasing hormone (LH-RH) on LH and follicle-stimulating hormone (FSH) release were studied in 26 normal children and six patients (from 1-to 14-years-old) with Turner's syndrome. (Author)

  8. Reconnaissance level study Mississippi storm surge barrier

    NARCIS (Netherlands)

    Van Ledden, M.; Lansen, A.J.; De Ridder, H.A.J.; Edge, B.

    2012-01-01

    This paper reports a reconnaissance level study of a storm surge barrier in the Mississippi River. Historical hurricanes have shown storm surge of several meters along the Mississippi River levees up to and upstream of New Orleans. Future changes due to sea level rise and subsidence will further

  9. Ovarian hyperstimulation, hyperprolactinaemia and LH gonadotroph adenoma.

    Science.gov (United States)

    Castelo-Branco, Camil; del Pino, Marta; Valladares, Esther

    2009-08-01

    This report considers a highly exceptional case of ovarian hyperstimulation syndrome due to a gonadotroph adenoma secreting LH in a 31-year-old patient who presented with amenorrhoea and galactorrhoea syndrome and a complex bilateral ovarian mass. Magnetic resonance imaging revealed a pituitary adenoma, and laboratory tests corroborated the hyperprolactinaemia without other hormonal pituitary abnormalities. Ovarian hyperstimulation syndrome due to a gonadotroph adenoma with normal gonadotrophins is extremely rare. Most of the described cases are caused by FSH adenomas. Due to the originality of the case, it was considered useful for understanding the management of this entity, and it is proposed that LH adenomas should also be considered in the differential diagnosis of patients with spontaneous ovarian hyperstimulation syndrome.

  10. Induction of ovarian activity and ovulation in an induced ovulator, the maned wolf (Chrysocyon brachyurus), using GnRH agonist and recombinant LH.

    Science.gov (United States)

    Johnson, Amy E M; Freeman, Elizabeth W; Colgin, Mark; McDonough, Caitlin; Songsasen, Nucharin

    2014-07-01

    Assisted reproductive techniques, such as ovarian manipulation and artificial insemination, are useful for enhancing genetic management of threatened wildlife maintained ex situ. In this study, we used noninvasive fecal hormone monitoring to investigate (1) the influence of pairing with a male on endocrine responses of female maned wolves (Chrysocyon brachyurus) to a GnRH agonist (deslorelin) and (2) the efficiency of recombinant LH (reLH) on ovulation induction in females housed alone. Deslorelin (2.1 mg Ovuplant) was given to females that were either paired with a male (n = 4) or housed alone (n = 7); the implant was removed 7 to 11 days postimplantation. Three of seven singleton females were injected with reLH (0.0375 mg) on the day of implant removal, whereas the remaining females (n = 4) did not receive the additional treatment. Fecal samples were collected 5 to 7 days/wk from all females starting 11 days prior to hormone insertion until at least 70 days post implant removal for a total of 11 hormone treatment cycles. Fecal estrogen and progestagen metabolites were extracted and analyzed by enzyme immunoassay. Evidence of ovulation, demonstrated by a surge of estrogen followed by a significant rise in progestagen, occurred in all paired females. Three of the four singleton females that did not receive reLH treatment exhibited no rise in progestagen after an estrogen surge. All singleton females treated with reLH exhibited a rise in fecal progestagen after injection, indicating ovulation. In conclusion, deslorelin is effective at inducing ovarian activity and ovulation in paired female maned wolves; however, exogenous reLH is needed to induce ovulation in females housed alone. The findings obtained from this study serve as a foundation for future application of artificial insemination to enhance genetic management of this threatened species ex situ. Published by Elsevier Inc.

  11. Kisspeptin and LH pulsatile temporal coupling in PCOS patients.

    Science.gov (United States)

    Katulski, Krzysztof; Podfigurna, Agnieszka; Czyzyk, Adam; Meczekalski, Blazej; Genazzani, Alessandro D

    2018-05-04

    To evaluate the temporal coupling between spontaneous kisspeptin and luteinizing hormone (LH) pulsatile releases in polycystic ovary syndrome (PCOS) patients. We examined 71 patients diagnosed with PCOS. A 2 h pulsatility study was performed to evaluate serum kisspeptin and LH pulse frequency and concentration, sampled every 10 min; baseline follicle-stimulating hormone (FSH), estradiol (E2), prolactin (PRL), cortisol, 17-hydroksy-progesterone (17OHP), testosterone (T), free testosterone index (FTI, and insulin levels were also measured. Detect and Specific Concordance (SC) algorithms were used to evaluate the temporal coupling associations between spontaneous episodic secretion of kisspeptin and LH. All PCOS patients demonstrated LH and kisspeptin pulsatile secretions. When the SC index was calculated across the sample of PCOS patients (n = 71), no temporal coupling was observed between kisspeptin and LH pulses. When PCOS patients were subdivided according to their menstrual cyclicity, oligomenorrheic patients demonstrated elevated kisspeptin pulse frequency. Additionally, the SC index reveled a temporal coupling between kisspeptin and LH secretory peaks only in eumenorrheic patients (n = 30, intermenstrual interval PCOS patients (intermenstrual interval > 45 days) did not demonstrate temporal coupling between kisspeptin and LH secretory peaks. The study of the endogenous kisspeptin and LH pulsatile release revealed the temporal coupling of kisspeptin with LH secretory pulses only in eumenorrheic. This data supports the hypothesis that neuroendocrine impairments in PCOS affect the coupling of kisspeptin with LH pulses and potentially worsen as the disease progresses, becoming unequivocally evident in oligomenorrheic PCOS patients.

  12. Validation of a surge model by full scale testing

    NARCIS (Netherlands)

    Smeulers, J.P.M.; Slot, H.J.; Meulendijks, D.

    2011-01-01

    Surge of turbo compressors can cause large stepwise changes in flow and pressure, which can potentially damage the compressor and any equipment that is in direct connection with the compressor. Surge is usually avoided by an anti surge controller (ASC). However, in spite of the ASC surge cycles may

  13. Validation of a surge model by full scale testing

    NARCIS (Netherlands)

    Slot, H.J.; Meulendijks, D.; Smeulers, J.P.M.

    2009-01-01

    Surge of turbo compressors can cause large stepwise changes in flow and pressure, which can potentially damage the compressor and any equipment that is in direct connection with the compressor. Surge is usually avoided by an anti surge controller (ASC). However, in spite of the ASC surge cycles may

  14. Ground Operations Demonstration Unit for Liquid Hydrogen (GODU LH2)

    Science.gov (United States)

    Notardonato, William U.

    2015-01-01

    When the technology associated with zero loss storage and transfer is implemented, NASA can reduce the LH2 losses and procurement costs by up to 30 compared to historical Shuttle numbers. This return on investment is based on the mission manifest and commodity use. LH2 densification can provide improved launch vehicle ascent performance by minimizing the size of the LH2 tanks or storing more mass of propellant in the given tank volume.

  15. Immunoreactive LH in long-term frozen human urine samples.

    Science.gov (United States)

    Singh, Gurmeet Kaur Surindar; Jimenez, Mark; Newman, Ron; Handelsman, David J

    2014-04-01

    Urine provides a convenient non-invasive alternative to blood sampling for measurement of certain hormones. Urinary luteinizing hormone (LH) measurements have been used for endocrinology research and anti-doping testing. However, the commercially available LH immunoassays are developed and validated for human blood samples but not urine so that LH assays intended for use with urine samples need thorough validation. Therefore, the present study evaluated the measurement of urinary LH immunoreactivity using previously validated immunofluorometric (IF) and immunochemiluminometric (ICL) LH assays after prolonged frozen storage. LH was measured in serial urine samples following administration of a single injection of one of two doses of recombinant human chorionic hormone (rhCG) with assays run at the end of study (2008) and again after four years of frozen (-20 °C) storage where samples were stored without adding preservatives. The ICL assay showed quantitatively reproducible LH measurements after prolonged -20 °C storage. However, the IF immunoassay gave consistently lower LH levels relative to ICL (2008) with a further proportionate reduction after four years of sample storage (2012). Yet, both the assays displayed similar patterns of the time-course of urine LH measurement both before and after four years of frozen storage. In conclusion, we found that both immunoassays are suitable for urinary LH measurements with ICL assay being more robust for quantitative urinary LH measurement such as for anti-doping purposes, whereas the IF could be applicable for research studies where urine LH levels are compared within-study but not in absolute terms. Copyright © 2013 John Wiley & Sons, Ltd.

  16. The relationship of EDLS, FSH and LH with PIH

    International Nuclear Information System (INIS)

    Zhang Xuefeng

    2003-01-01

    To evaluate the role of serum EDLS, FSH and LH in the pathogenesis of PIH, levels of serum EDLS, FSH and LH were measured by radioimmunoassay in 200 patients with PIH. Results: In PIH group, mean level of serum EDLS was significantly higher than that in the normal control group (P<0.01); mean levels of serum FSH and LH were significantly lower than that in the normal control group (P<0.001). EDLS, FSH and LH may play important action in the pathogenesis of PIH

  17. Arsenic induced progesterone production in a caspase-3-dependent manner and changed redox status in preovulatory granulosa cells.

    Science.gov (United States)

    Yuan, Xiao-Hua; Lu, Cai-Ling; Yao, Nan; An, Li-Sha; Yang, Bai-Qing; Zhang, Chuan-Ling; Ma, Xu

    2012-01-01

    Arsenic contamination is a principal environmental health threat throughout the world. However, little is known about the effect of arsenic on steroidogenesis in granulosa cells (GCs). We found that the treatment of preovulatory GCs with arsenite stimulated progesterone production. A significant increase in serum level of progesterone was observed in female Sprague-Dawley rats following arsenite treatment at a dose of 10 mg/L/rat/day for 7 days. Further experiments demonstrated that arsenite treatment did not change the level of intracellular cyclic AMP (cAMP) or phosphorylated ERK1/2 in preovulatory GCs; however, progesterone production was significantly decreased when cAMP-dependent protein kinase (PKA) or ERK1/2 pathway was inhibited. This implied that the effect of arsenite on progesterone production may require cAMP/PKA and ERK1/2 signaling but not depend on them. Furthermore, we found that arsenite decreased intracellular reactive oxygen species (ROS) but increased the antioxidant glutathione (GSH) levels and mitochondrial membrane potential (ΔΨm) in parallel to the changes in progesterone production. Progesterone antagonist blocked the arsenic-stimulated increase of GSH levels. Arsenite treatment induced caspase-3 activation, although no apoptosis was observed. Inhibition of caspase-3 activity significantly decreased progesterone production stimulated by arsenite or follicle-stimulating hormone (FSH). GSH depletion with buthionine sulfoximine led to cell apoptosis in response to arsenite treatment. Collectively, this study demonstrated for the first time that arsenite stimulates progesterone production through cleaved/active caspase-3-dependent pathway, and the increase of GSH level promoted by progesterone production may protect GCs against apoptosis and maintain the steroidogenesis of GCs in response to arsenite treatment. Copyright © 2011 Wiley Periodicals, Inc.

  18. Analysis of Storm Surge in Hong Kong

    Science.gov (United States)

    Kao, W. H.

    2017-12-01

    A storm surge is a type of coastal flood that is caused by low-pressure systems such as tropical cyclones. Storm surges caused by tropical cyclones can be very powerful and damaging, as they can flood coastal areas, and even destroy infrastructure in serious cases. Some serious cases of storm surges leading to more than thousands of deaths include Hurricane Katrina (2005) in New Orleans and Typhoon Haiyan (2013) in Philippines. Hong Kong is a coastal city that is prone to tropical cyclones, having an average of 5-6 tropical cyclones entering 500km range of Hong Kong per year. Storm surges have seriously damaged Hong Kong in the past, causing more than 100 deaths by Typhoon Wanda (1962), and leading to serious damage to Tai O and Cheung Chau by Typhoon Hagupit (2008). To prevent economic damage and casualties from storm surges, accurately predicting the height of storm surges and giving timely warnings to citizens is very important. In this project, I will be analyzing how different factors affect the height of storm surge, mainly using data from Hong Kong. These factors include the windspeed in Hong Kong, the atmospheric pressure in Hong Kong, the moon phase, the wind direction, the intensity of the tropical cyclone, distance between the tropical cyclone and Hong Kong, the direction of the tropical cyclone relative to Hong Kong, the speed of movement of the tropical cyclone and more. My findings will also be compared with cases from other places, to see if my findings also apply for other places.

  19. α-Estrogen and Progesterone Receptors Modulate Kisspeptin Effects on Prolactin: Role in Estradiol-Induced Prolactin Surge in Female Rats.

    Science.gov (United States)

    Aquino, Nayara S S; Araujo-Lopes, Roberta; Henriques, Patricia C; Lopes, Felipe E F; Gusmao, Daniela O; Coimbra, Candido C; Franci, Celso R; Reis, Adelina M; Szawka, Raphael E

    2017-06-01

    Kisspeptin (Kp) regulates prolactin (PRL) in an estradiol-dependent manner. We investigated the interaction between ovarian steroid receptors and Kp in the control of PRL secretion. Intracerebroventricular injections of Kp-10 or Kp-234 were performed in ovariectomized (OVX) rats under different hormonal treatments. Kp-10 increased PRL release and decreased 3,4-dihydroxyphenylacetic acid levels in the median eminence (ME) of OVX rats treated with estradiol (OVX+E), which was prevented by tamoxifen. Whereas these effects of Kp-10 were absent in OVX rats, they were replicated in OVX rats treated with selective agonist of estrogen receptor (ER)α, propylpyrazole triol, but not of ERβ, diarylpropionitrile. Furthermore, the Kp-10-induced increase in PRL was two times higher in OVX+E rats also treated with progesterone (OVX+EP), which was associated with a reduced expression of both tyrosine hydroxylase (TH) and Ser40-phosphorylated TH in the ME. Kp-10 also reduced dopamine levels in the ME of OVX+EP rats, an effect blocked by the progesterone receptor (PR) antagonist RU486. We also determined the effect of Kp antagonism with Kp-234 on the estradiol-induced surges of PRL and luteinizing hormone (LH), using tail-tip blood sampling combined with ultrasensitive enzyme-linked immunosorbent assay. Kp-234 impaired the early phase of the PRL surge and prevented the LH surge in OVX+E rats. Thus, we provide evidence that Kp stimulation of PRL release requires ERα and is potentiated by progesterone via PR activation. Moreover, alongside its essential role in the LH surge, Kp seems to play a role in the peak phase of the estradiol-induced PRL surge. Copyright © 2017 Endocrine Society.

  20. [Determining visual acuity with LH symbols and Landolt rings].

    Science.gov (United States)

    Gräf, M; Becker, R

    1999-08-01

    Lea (LH) symbols seem to be favourable for visual acuity assessment in childhood. The symbols of the LH test are well standardized and applicable to preschool children. We compared the visual acuity determined by LH single symbols (LH) and the acuity measured with the Landolt-C (LC). 138 cooperative subjects aged 7 to 91 years were examined. Their visual acuity was either normal or reduced due to various etiologies. Their refractive error was corrected. The monocular LH and LC were determined by a 3/4 criterion (study 1). In 19 healthy subjects aged 21 to 58 years, acuity was reduced stepwise by 5 different calibrated occlusives (study 2). A Lighthouse single symbol book (LH symbols) was used at a distance of 3 m. LC was determined at a distance of 5 m. The luminance of the test field was 180-200 cd/m2. The right eye of each patient and the amblyopic eye of the squinting patients was taken for statistical evaluation. The strabismic patients' interocular differences of LC and LH were compared. Within study 1, LC ranged from 0.02 to 2.0 and LH from 0.03 to 2.5. LH overestimated LC by 1.4 lines on an average (t-test p 1 line, 85.7% resp. 90% of the strabismic amblyopic patients with an interocular LC difference > 1 resp > 2 lines were detected. In study 2, LC ranged from 0.1 to 1.6, LH from 0.12 to 2.0. The mean difference LH-LC was 1.3 lines. The regression equation was lgLH = 0.91 lgLC + 0.08 (r = 0.95). LH symbols allow a reliable measurement of recognition acuity. Due to the design of the symbols, they are excellently suitable for application to preschool children. Age related normal values should be established. The systematic difference between the LC acuity and the LH acuity measured with the Lighthouse LH single symbol book by 1.4 lines has to be considered.

  1. Volume-based characterization of postocclusion surge.

    Science.gov (United States)

    Zacharias, Jaime; Zacharias, Sergio

    2005-10-01

    To propose an alternative method to characterize postocclusion surge using a collapsible artificial anterior chamber to replace the currently used rigid anterior chamber model. Fundación Oftamológica Los Andes, Santiago, Chile. The distal end of a phacoemulsification handpiece was placed inside a compliant artificial anterior chamber. Digital recordings of chamber pressure, chamber volume, inflow, and outflow were performed during occlusion break of the phacoemulsification tip. The occlusion break profile of 2 different consoles was compared. Occlusion break while using a rigid anterior chamber model produced a simultaneous increase of chamber inflow and outflow. In the rigid chamber model, pressure decreased sharply, reaching negative pressure values. Alternatively, with the collapsible chamber model, a delay was observed in the inflow that occurs to compensate the outflow surge. Also, the chamber pressure drop was smaller in magnitude, never undershooting below atmospheric pressure into negative values. Using 500 mm Hg as vacuum limit, the Infiniti System (Alcon) performed better that the Legacy (Alcon), showing an 18% reduction in peak volume variation. The collapsible anterior chamber model provides a more realistic representation of the postocclusion surge events that occur in the real eye during cataract surgery. Peak volume fluctuation (mL), half volume recovery time(s), and volume fluctuation integral value (mL x s) are proposed as realistic indicators to characterize the postocclusion surge performance. These indicators show that the Infiniti System has a better postocclusion surge behavior than the Legacy System.

  2. Membrane Curvature Induced by Aggregates of LH2s and Monomeric LH1s

    OpenAIRE

    Chandler, Danielle E.; Gumbart, James; Stack, John D.; Chipot, Christophe; Schulten, Klaus

    2009-01-01

    The photosynthetic apparatus of purple bacteria is contained within organelles called chromatophores, which form as extensions of the cytoplasmic membrane. The shape of these chromatophores can be spherical (as in Rhodobacter sphaeroides), lamellar (as in Rhodopseudomonas acidophila and Phaeospirillum molischianum), or tubular (as in certain Rb. sphaeroides mutants). Chromatophore shape is thought to be influenced by the integral membrane proteins Light Harvesting Complexes I and II (LH1 and ...

  3. Fluorescence spectroscopy of conformational changes of single LH2 complexes

    NARCIS (Netherlands)

    Rutkauskas, D.; Novoderezhkin, V.; Cogdell, R.J.; van Grondelle, R.

    2005-01-01

    We have investigated the energy landscape of the bacterial photosynthetic peripheral light-harvesting complex LH2 of purple bacterium Rhodopseudomonas acidophila by monitoring sequences of fluorescence spectra of single LH2 assemblies, at room temperature, with different excitation intensities as

  4. Comparison of radioimmunology and serology methods for LH determination

    International Nuclear Information System (INIS)

    Szymanski, W.; Jakowicki, J.

    1976-01-01

    A comparison is presented of LH determinations by immunoassay and radioimmunoassay using the 125 I-labelled HCG double antibody system. The results obtained by both methods are well comparable and in normal and elevated LH levels the serological determinations may be used for estimating concentration levels found by RIA. (L.O.)

  5. Adaptive mesh refinement for storm surge

    KAUST Repository

    Mandli, Kyle T.; Dawson, Clint N.

    2014-01-01

    An approach to utilizing adaptive mesh refinement algorithms for storm surge modeling is proposed. Currently numerical models exist that can resolve the details of coastal regions but are often too costly to be run in an ensemble forecasting framework without significant computing resources. The application of adaptive mesh refinement algorithms substantially lowers the computational cost of a storm surge model run while retaining much of the desired coastal resolution. The approach presented is implemented in the GeoClaw framework and compared to ADCIRC for Hurricane Ike along with observed tide gauge data and the computational cost of each model run. © 2014 Elsevier Ltd.

  6. Adaptive mesh refinement for storm surge

    KAUST Repository

    Mandli, Kyle T.

    2014-03-01

    An approach to utilizing adaptive mesh refinement algorithms for storm surge modeling is proposed. Currently numerical models exist that can resolve the details of coastal regions but are often too costly to be run in an ensemble forecasting framework without significant computing resources. The application of adaptive mesh refinement algorithms substantially lowers the computational cost of a storm surge model run while retaining much of the desired coastal resolution. The approach presented is implemented in the GeoClaw framework and compared to ADCIRC for Hurricane Ike along with observed tide gauge data and the computational cost of each model run. © 2014 Elsevier Ltd.

  7. Evaluation of the double antibody - solid phase radioimmunoassay technique in plasma LH and FSH and urinary LH measurements

    International Nuclear Information System (INIS)

    Karonen, S.-L.; Laehteenmaeki, P.; Hohenthal, U.; Adlercreutz, H.

    1978-01-01

    Double antibody phase (DASP) radioimmunoassay methods for plasma LH and FSH and urinary LH were developed and carefully evaluated as to their reliability and practicability. The peptide hormones were iodinated enzymatically with immobilized lactoperoxidase which resulted in pure and stable products of unchanged immunoreactivity. The sensitivities of these assay methods are 0.02, 0.17 and 0.20 mlU/tube for plasma LH (MRC 68/40) and FSH (MRC 68/39) and urinary LH (IRP-HMG, urinary), respectively. Interassay coefficients of variation obtained over a 6-18 month period were 14.2, 14.7 and 12.8%, respectively. The latter values for plasma LH and FSH assays were obtained from one level pool samples, and the value for urinary LH is the mean of those obtained from two pools of different levels. Plasma reference values for LH and FSH obtained using these methods are about 1.8-2.9 times higher than those cited for other types of radioimmunoassay. However, the values obtained for LH in urine are similar to those reported in the literature. It is suggested that the DASP technique is less influenced by interference from plasma proteins and because of this gives plasma values closer to the true ones. It is concluded that the methods are well suited for use as routine clinical assays in laboratories with a high work load. (Auth.)

  8. A disordered polaron model for polarized fluorescence excitation spectra of LH1 and LH2 bacteriochlorophyll antenna aggregates

    International Nuclear Information System (INIS)

    Trinkunas, Gediminas; Freiberg, Arvi

    2006-01-01

    Excitonic polarons in antenna complexes are subject to static lattice disorder. A model has been developed to analyze polarized fluorescence excitation spectra of circular light-harvesting complexes from purple photosynthetic bacteria containing bacteriochlorophyll as the main photoactive pigment that includes both diagonal (energetic) and off-diagonal (structural) disorders. Essential differences of disorder realizations seem to exist between the core LH1 and peripheral LH2 complexes from the bacterium Rhodobacter sphaeroides. The disorder in LH1 appears to be dominated by the structural disorder, while that in LH2, by energetic one. These differences may be due to relatively bigger size of the LH1 complex and, consequently, with its enhanced structural flexibility

  9. Exercising Tactically for Taming Postmeal Glucose Surges.

    Science.gov (United States)

    Chacko, Elsamma

    2016-01-01

    This review seeks to synthesize data on the timing, intensity, and duration of exercise found scattered over some 39 studies spanning 3+ decades into optimal exercise conditions for controlling postmeal glucose surges. The results show that a light aerobic exercise for 60 min or moderate activity for 20-30 min starting 30 min after meal can efficiently blunt the glucose surge, with minimal risk of hypoglycemia. Exercising at other times could lead to glucose elevation caused by counterregulation. Adding a short bout of resistance exercise of moderate intensity (60%-80%  VO2max) to the aerobic activity, 2 or 3 times a week as recommended by the current guidelines, may also help with the lowering of glucose surges. On the other hand, high-intensity exercise (>80%  VO2max) causes wide glucose fluctuations and its feasibility and efficacy for glucose regulation remain to be ascertained. Promoting the kind of physical activity that best counters postmeal hyperglycemia is crucial because hundreds of millions of diabetes patients living in developing countries and in the pockets of poverty in the West must do without medicines, supplies, and special diets. Physical activity is the one tool they may readily utilize to tame postmeal glucose surges. Exercising in this manner does not violate any of the current guidelines, which encourage exercise any time.

  10. Exercising Tactically for Taming Postmeal Glucose Surges

    Directory of Open Access Journals (Sweden)

    Elsamma Chacko

    2016-01-01

    Full Text Available This review seeks to synthesize data on the timing, intensity, and duration of exercise found scattered over some 39 studies spanning 3+ decades into optimal exercise conditions for controlling postmeal glucose surges. The results show that a light aerobic exercise for 60 min or moderate activity for 20–30 min starting 30 min after meal can efficiently blunt the glucose surge, with minimal risk of hypoglycemia. Exercising at other times could lead to glucose elevation caused by counterregulation. Adding a short bout of resistance exercise of moderate intensity (60%–80%  VO2max to the aerobic activity, 2 or 3 times a week as recommended by the current guidelines, may also help with the lowering of glucose surges. On the other hand, high-intensity exercise (>80%  VO2max causes wide glucose fluctuations and its feasibility and efficacy for glucose regulation remain to be ascertained. Promoting the kind of physical activity that best counters postmeal hyperglycemia is crucial because hundreds of millions of diabetes patients living in developing countries and in the pockets of poverty in the West must do without medicines, supplies, and special diets. Physical activity is the one tool they may readily utilize to tame postmeal glucose surges. Exercising in this manner does not violate any of the current guidelines, which encourage exercise any time.

  11. The dynamics of surge in compression systems

    Indian Academy of Sciences (India)

    is of interest to study compression-system surge to understand its dynamics in order ... Internal problems like compressor going into rotating stall, resulting in loss of ... of water column, was used for mass-flow measurement at the impeller entry.

  12. Positive feedback stabilization of centrifugal compressor surge

    NARCIS (Netherlands)

    Willems, Frank; Heemels, W.P.M.H.; de Jager, Bram; Stoorvogel, Antonie Arij

    Stable operation of axial and centrifugal compressors is limited towards low mass flows due to the occurrence of surge. The stable operating region can be enlarged by active control. In this study, we use a control valve which is fully closed in the desired operating point and only opens to

  13. Positive feedback stabilization of centrifugal compressor surge

    NARCIS (Netherlands)

    Willems, F.P.T.; Heemels, W.P.M.H.; Jager, de A.G.; Stoorvogel, A.A.

    2002-01-01

    Stable operation of axial and centrifugal compressors is limited towards low mass flows due to the occurrence of surge. The stable operating region can be enlarged by active control. In this study, we use a control valve which is fully closed in the desired operating point and only opens to

  14. Overview of L-H power threshold studies in NSTX

    International Nuclear Information System (INIS)

    Maingi, R.; Biewer, T.M.; Kaye, S.M.; Bell, R.E.; Gates, D.A.; Gerhardt, S.P.; Hosea, J.; LeBlanc, B.P.; Mueller, D.; Stevenson, T.A.; Wilson, J.R.; Chang, C.S.; Park, G-Y.; Meyer, H.; Raman, R.; Sabbagh, S.A.

    2010-01-01

    A summary of results from recent L-H power threshold (P LH ) experiments in the National Spherical Torus Experiment is presented. First P LH (normalized linearly by plasma density) was found to be a minimum in double-null configuration, tending to increase as the plasma was shifted more strongly towards lower- or upper-single null configuration with either neutral beam or rf heating. The measured P LH /n e was comparable with neutral beam or rf heating, suggesting that rotation was not playing a dominant role in setting the value of P LH . The role of triangularity (δ bot ) in setting P LH /n e is less clear: while 50% less auxiliary heating power was required to access H-mode at low δ bot than at high δ bot , the high δ bot discharges had lower ohmic heating and higher dW/dt, leading to comparable loss of power over a range of δ bot . In addition, the dependences of P LH on the density, species (helium versus deuterium), plasma current, applied non-axisymmetric error fields and lithium wall conditioning are summarized.

  15. Avian LH and FSH: comparison of several radioimmunoassays

    International Nuclear Information System (INIS)

    Goldsmith, A.R.; Follett, B.K.

    1983-01-01

    Comparisons were made between various LH and FSH radioimmunoassays currently being used to measure avian hormones. The two LH assays were the homologous chicken system of Follett et al. (1972) and the turkey assay of Burke et al. (1979). These assays were also used in heterologous arrangement by interchanging the iodinated LH fractions and antisera. Five FSH assays were analyzed: two homologous chicken systems (Scanes et al., 1977; Sakai and Ishii, 1980) an assay based on mammalian materials (rat FSH and anti-ovine FSH antiserum, and one using labelled turkey FSH (Burke et al., 1979) with an anti-chicken FSH antiserum. The potencies of purified chicken and turkey gonadotrophin preparations and of a range of plasma samples from Japanese quail were measured in each assay. The two LH systems showed some degree of species specificity, such that chicken LH was more active than turkey LH in the chicken assay, whereas the reverse was true in the turkey LH assay. The potency estimates of the purified hormones in the various FSH assays were very consistent. The qualitative changes in plasma hormone levels were similar in all assays, although there were some differences in the magnitude of the responses

  16. Effect of piping systems on surge in centrifugal compressors

    International Nuclear Information System (INIS)

    Tamaki, Hideaki

    2008-01-01

    There is a possibility that the exchange of the piping system may change the surge characteristic of a compressor. The piping system of a plant is not always the same as that of a test site. Then it is important to evaluate the effect of piping systems on surge characteristics in centrifugal compressors. Several turbochargers combined with different piping systems were tested. The lumped parameter model which was simplified to be solved easily was applied for the prediction of surge point. Surge lines were calculated with the linearlized lumped parameter model. The difference between the test and calculated results was within 10 %. Trajectory of surge cycle was also examined by solving the lumped parameter model. Mild surge and deep surge were successfully predicted. This study confirmed that the lumped parameter model was a very useful tool to predict the effect of piping systems on surge characteristics in centrifugal compressors, even though that was a simple model

  17. Intra-uterine insemination: pregnancy rate in relation to number, size of pre-ovulatory follicles and day of insemination.

    Science.gov (United States)

    Karuppaswamy, J; Smedley, Mamin; Carter, Lindsay

    2009-03-01

    The objective of the study was to analyse the pregnancy rate in intra-uterine insemination (IUI) in relation to pre-ovulatory follicular number, size and day of insemination. A retrospective analysis of 216 completed IUI cycles was used in an attempt to identify significant variables predictive of treatment success. Couples with unexplained infertility and male factor infertility underwent IUI with or without ovarian stimulation. The mean number of IUI cycles per patient was 4.1, the overall pregnancy rate was 27.3% per patient, and the pregnancy rate per cycle was 6.9%. The pregnancy rate was 4.4% when one follicle was produced, whereas with more than two follicles, the rate increased to 21.2%. Hormonal stimulation using clomiphene citrate and/or human menopausal gonadotrophin/follicle stimulating hormone yielded a significant higher pregnancy rate compared to IUI in natural cycles (10.3% versus 3.3%). Although not statistically significant, the pregnancy rate decreased with advancing age of woman. The results suggest that IUI is a useful method of assisted conception in unexplained infertility and higher pregnancy rates can be achieved with good patient selection and ovarian stimulation.

  18. 48 CFR 252.217-7001 - Surge option.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Surge option. 252.217-7001... Clauses 252.217-7001 Surge option. As prescribed in 217.208-70(b), use the following clause: Surge Option (AUG 1992) (a) General. The Government has the option to— (1) Increase the quantity of supplies or...

  19. Surge flow irrigation under short field conditions in Egypt

    NARCIS (Netherlands)

    Ismail, S.M.; Depeweg, H.; Schultz, E.

    2004-01-01

    Several studies carried out in long furrows have shown that surge flow irrigation offers the potential of increasing the efficiency of irrigation. The effects of surge flow in short fields, such as in Egypt, are still not well known, however. To investigate the effect of surge flow irrigation in

  20. Validation of a surge model by full scale testing

    NARCIS (Netherlands)

    Smeulers, J.P.M.; Gonzalez Díez, N.; Slot, H.J.

    2012-01-01

    Surge of turbo compressors can cause large almost step like changes in flow and pressure, which can potentially damage the compressor and any equipment that is in direct connection with the compressor. In spite of an anti-surge controller (ASC), at extreme events surge cycles may occur. In order to

  1. Numerical Evaluation of Storm Surge Indices for Public Advisory Purposes

    Science.gov (United States)

    Bass, B.; Bedient, P. B.; Dawson, C.; Proft, J.

    2016-12-01

    After the devastating hurricane season of 2005, shortcomings with the Saffir-Simpson Hurricane Scale's (SSHS) ability to characterize a tropical cyclones potential to generate storm surge became widely apparent. As a result, several alternative surge indices were proposed to replace the SSHS, including Powell and Reinhold's Integrated Kinetic Energy (IKE) factor, Kantha's Hurricane Surge Index (HSI), and Irish and Resio's Surge Scale (SS). Of the previous, the IKE factor is the only surge index to-date that truly captures a tropical cyclones integrated intensity, size, and wind field distribution. However, since the IKE factor was proposed in 2007, an accurate assessment of this surge index has not been performed. This study provides the first quantitative evaluation of the IKEs ability to serve as a predictor of a tropical cyclones potential surge impacts as compared to other alternative surge indices. Using the tightly coupled ADvanced CIRCulation and Simulating WAves Nearshore models, the surge and wave responses of Hurricane Ike (2008) and 78 synthetic tropical cyclones were evaluated against the SSHS, IKE, HSI and SS. Results along the upper TX coast of the Gulf of Mexico demonstrate that the HSI performs best in capturing the peak surge response of a tropical cyclone, while the IKE accounting for winds greater than tropical storm intensity (IKETS) provides the most accurate estimate of a tropical cyclones regional surge impacts. These results demonstrate that the appropriate selection of a surge index ultimately depends on what information is of interest to be conveyed to the public and/or scientific community.

  2. Tracing of backward energy transfer from LH1 to LH2 in photosynthetic membranes grown under high and low irradiation.

    Directory of Open Access Journals (Sweden)

    Lanzani G.

    2013-03-01

    Full Text Available By introducing derivative transient absorption spectroscopy, we obtain rate constants for backward and forward energy transfer between LH1 and LH2 complexes in purple bacterial membranes. We find that backward energy transfer is strongly reduced in membranes grown under low irradiation conditions, compared to high light grown ones. We conclude that backward energy transfer is managed actively by the bacteria to avoid LH1 exciton deactivation under high irradiation conditions. The analytical method is generally applicable to excitonically coupled systems.

  3. Aerodigitalni senzori - LH Systems ADS 40 / Airborne digital sensors: LH Systems ADS 40

    Directory of Open Access Journals (Sweden)

    Marko Pejić

    2004-01-01

    Full Text Available U radu su prezentovane osnove prikupljanja prostornih podataka metodom daljinske detekcije i klasičnim fotogrametrijskim metodom. Ukazano je na kompromis između dva metoda koji nudi digitalna aerokamera. Kompanija LH Systems proizvela je digitalnu aerokameru ADS 40 koja nudi sasvim nov koncept prikupljanja prostornih podataka. Sistem kamere obezbeđuje panhromatske i trodimenzionalne informacije koristeći tri CCD linije i opciono još pet linija iz multispektralnog opsega. Kamera skenira teren sa prostornom rezolucijom od 25 cm, površine od 300 kvadratnih kilometara, uz vreme trajanja leta koje je nešto kraće od jednog sata. / This paper presents basics of collecting spatial data with remote sensing and the classical photogrammetric method. A compromise between two methods, offered by a digital aero camera, is also suggested. The LH Systems has produced a new camera concept called Airborne Digital Sensor (ADS 40 which uses a new way of collecting spatial data. The camera system provides panchromatic and stereo information using three CCD lines and up to five more lines for multispectral imagery. The performance of the camera allows a three dimensional and multispectral image with a ground sample distance of 25 cm for an area of 300 square miles within a flight time shorter than one hour.

  4. The pattern of LH secretion and the ovarian response to the 'ram effect' in the anoestrous ewe is influenced by body condition but not by short-term nutritional supplementation.

    Science.gov (United States)

    Scaramuzzi, R J; Oujagir, L; Menassol, J-B; Freret, S; Piezel, A; Brown, H M; Cognié, J; Fabre Nys, C

    2014-10-01

    In sheep, the 'ram effect' induces out-of-season fertility and good nutrition increases prolificacy. This experiment determined if fatness or short-term nutritional supplementation modified the response to the 'ram effect'. A group of 48 Île-de-France ewes were fed diets that produced groups with body-condition scores (BCS) of >3.0 and <2.0. Within each BCS group animals were supplemented daily with 500g of lupins from Day -5 to Day 0 (ram introduction) resulting in four groups: low BCS, supplemented (n=7) and non-supplemented (n=8) and high BCS, supplemented (n=12) and non-supplemented (n=11). The blood concentrations of glucose and insulin and the LH response to gonadotrophin-releasing hormone (GnRH) were determined. After the 'ram effect' the pattern of LH pulsatility, the LH surge and ovarian responses were analysed. Low BCS ewes had lower glucose and insulin (P<0.001) and supplementation increased both (P≤0.001). The increase in LH induced by GnRH was reduced in low BCS ewes (P=0.015) but it was not affected by supplementation. Similarly, LH pulsatility was reduced in low BCS ewes (P<0.05). The LH surge and ovarian cyclicity were not affected but the follow-up cycle was delayed (P=0.034) and progesterone was reduced (P=0.029) in low BCS ewes. There was an effect of BCS on ovulation rate (P<0.05). These results show that the BCS can modify the response to the 'ram effect' and that supplementation has little effect on this response.

  5. Energy Exchange Dynamics across L-H transitions in NSTX

    Science.gov (United States)

    Diallo, Ahmed

    2017-10-01

    H-mode is planned for future devices such as ITER, and is preceded by a low (L) to high (H) transition. A key question remains. What is the mechanism behind the L-H transition? Most theoretical descriptions of the L-H transition are based on the shear of the radial electric field and coincident ExB poloidal flow shear, which is thought to be responsible for the onset of the anomalous transport suppression that leads to the L-H transition. This talk will focus on the analysis of the flow dynamics across the L-H transition in NSTX. We analyze the L-H transition dynamics using the velocimetry of 2D edge turbulence data from gas-puff imaging (GPI). We determine the velocity components at the edge across the L-H transition for 17 discharges with three types of heating power (NBI, ohmic, and RF). Using a reduced model equation of edge flows and turbulence, the energy transfer dynamics is compared with the turbulence depletion hypothesis of the predator-prey model. In order for Reynolds work to suppress the turbulence, it must deplete the total turbulent free energy, including the thermal free-energy term. For this to occur, the increase in kinetic energy in the mean flow over the L-H transition must be comparable to the pre-transition thermal free energy. However, this ratio was found to be of order 10-2. Although there are significant simplifications in the theoretical model, they are unlikely to cause inaccuracy by two orders of magnitude, suggesting that direct turbulence depletion by the Reynolds work may not be large enough to explain the L-H transition on NSTX, contrary to the predator-prey model. This work is supported by the US DOE Contract No. DE-AC02-09CH11466.

  6. Nonlinear chaotic model for predicting storm surges

    Directory of Open Access Journals (Sweden)

    M. Siek

    2010-09-01

    Full Text Available This paper addresses the use of the methods of nonlinear dynamics and chaos theory for building a predictive chaotic model from time series. The chaotic model predictions are made by the adaptive local models based on the dynamical neighbors found in the reconstructed phase space of the observables. We implemented the univariate and multivariate chaotic models with direct and multi-steps prediction techniques and optimized these models using an exhaustive search method. The built models were tested for predicting storm surge dynamics for different stormy conditions in the North Sea, and are compared to neural network models. The results show that the chaotic models can generally provide reliable and accurate short-term storm surge predictions.

  7. Influence of Surge on Extreme Roll Amplitudes

    DEFF Research Database (Denmark)

    Vidic-Perunovic, Jelena; Rognebakke, Olav; Pedersen, Preben Terndrup

    2008-01-01

    Interference of the wave-induced ship surge motion with roll dynamics has been studied. The surge motion has been included in a previously derived hydrodynamic roll prediction model in order to account for the ship speed variation due to the longitudinal incident wave pressure force. Depending...... balanced in order to determine the added thrust term that would represent actions to maintain speed The resulting forward speed variation affects the frequency of encounter and the parametric roll resonant condition is directly influenced by this speed variation. The analysis procedure is demonstrated...... for an example containership sailing mainly in head sea condition and higher sea states. Sensitivity of the results to the added thrust model and vertical motion calculation is discussed....

  8. Conditions and limits of serum LH radioimmunoassay in normal, hypophysectomised or castred rats

    International Nuclear Information System (INIS)

    Andre, M.; Boucher, D.; Thieblot, L.

    1976-01-01

    Serum LH was measured by radioimmunoassay (NIAMD Kits) free and linked hormones were separated by double antibodies method. Influence of concentration on antibody-hormone complex is studied. Hypophysectomised rats serum does not modify results. The standard (rat LH-RPl) has the same action as serum LH. Rat serum LH contents are measured in normal or castred rats [fr

  9. Interleukin-1 (IL-1 system gene expression in granulosa cells: kinetics during terminal preovulatory follicle maturation in the mare

    Directory of Open Access Journals (Sweden)

    Gérard Nadine

    2003-05-01

    Full Text Available Abstract Background A growing body of evidences suggests that the ovary is a site of inflammatory reactions, and thus, ovarian cells could represent sources and targets of the interleukin-1 (IL-1 system. The purpose of this study was to examine the IL-1 system gene expressions in equine granulosa cells, and to study the IL-1β content in follicular fluid during the follicle maturation. For this purpose, granulosa cells and follicular fluids were collected from the largest follicle at the early dominance stage (diameter 24 ± 3 mm or during the preovulatory maturation phase, at T0 h, T6 h, T12 h, T24 h and T34 h after induction of ovulation. Cells were analysed by RT-PCR and follicular fluids were studied by gel electrophoresis and immunoblotting. Results We demonstrated that interleukin-1β (IL-1β, interleukin-1 receptor 2 (IL-1R2 and interleukin-1 receptor antagonist (IL-1RA genes are expressed in equine granulosa cells. We observed that the IL-1β and IL-1RA mRNA content changed in granulosa cells during the terminal follicular maturation whereas IL-1R2 mRNA did not vary. In follicular fluid, IL-1β content fluctuated few hours after induction of ovulation. Conclusions The expression of IL-1β gene in granulosa cells and the follicular fluid IL-1β content seem to be regulated by gonadotropins suggesting that IL-1β could be an intermediate paracrine factor involved in ovulation.

  10. Coastal emergency managers' preferences for storm surge forecast communication.

    Science.gov (United States)

    Morrow, Betty Hearn; Lazo, Jeffrey K

    2014-01-01

    Storm surge, the most deadly hazard associated with tropical and extratropical cyclones, is the basis for most evacuation decisions by authorities. One factor believed to be associated with evacuation noncompliance is a lack of understanding of storm surge. To address this problem, federal agencies responsible for cyclone forecasts are seeking more effective ways of communicating storm surge threat. To inform this process, they are engaging various partners in the forecast and warning process.This project focuses on emergency managers. Fifty-three emergency managers (EMs) from the Gulf and lower Atlantic coasts were surveyed to elicit their experience with, sources of, and preferences for storm surge information. The emergency managers-who are well seasoned in hurricane response and generally rate the surge risk in their coastal areas above average or extremely high-listed storm surge as their major concern with respect to hurricanes. They reported a general lack of public awareness about surge. Overall they support new ways to convey the potential danger to the public, including the issuance of separate storm surge watches and warnings, and the expression of surge heights using feet above ground level. These EMs would like more maps, graphics, and visual materials for use in communicating with the public. An important concern is the timing of surge forecasts-whether they receive them early enough to be useful in their evacuation decisions.

  11. Exposure of Lactating Dairy Cows to Acute Pre-Ovulatory Heat Stress Affects Granulosa Cell-Specific Gene Expression Profiles in Dominant Follicles

    Science.gov (United States)

    Vanselow, Jens; Vernunft, Andreas; Koczan, Dirk; Spitschak, Marion; Kuhla, Björn

    2016-01-01

    High environmental temperatures induce detrimental effects on various reproductive processes in cattle. According to the predicted global warming the number of days with unfavorable ambient temperatures will further increase. The objective of this study was to investigate effects of acute heat stress during the late pre-ovulatory phase on morphological, physiological and molecular parameters of dominant follicles in cycling cows during lactation. Eight German Holstein cows in established lactation were exposed to heat stress (28°C) or thermoneutral conditions (15°C) with pair-feeding for four days. After hormonal heat induction growth of the respective dominant follicles was monitored by ultrasonography for two days, then an ovulatory GnRH dose was given and follicular steroid hormones and granulosa cell-specific gene expression profiles were determined 23 hrs thereafter. The data showed that the pre-ovulatory growth of dominant follicles and the estradiol, but not the progesterone concentrations tended to be slightly affected. mRNA microarray and hierarchical cluster analysis revealed distinct expression profiles in granulosa cells derived from heat stressed compared to pair-fed animals. Among the 255 affected genes heatstress-, stress- or apoptosis associated genes were not present. But instead, we found up-regulation of genes essentially involved in G-protein coupled signaling pathways, extracellular matrix composition, and several members of the solute carrier family as well as up-regulation of FST encoding follistatin. In summary, the data of the present study show that acute pre-ovulatory heat stress can specifically alter gene expression profiles in granulosa cells, however without inducing stress related genes and pathways and suggestively can impair follicular growth due to affecting the activin-inhibin-follistatin system. PMID:27532452

  12. Understanding L-H transition in tokamak fusion plasmas

    Science.gov (United States)

    Xu, Guosheng; Wu, Xingquan

    2017-03-01

    This paper reviews the current state of understanding of the L-H transition phenomenon in tokamak plasmas with a focus on two central issues: (a) the mechanism for turbulence quick suppression at the L-H transition; (b) the mechanism for subsequent generation of sheared flow. We briefly review recent advances in the understanding of the fast suppression of edge turbulence across the L-H transition. We uncover a comprehensive physical picture of the L-H transition by piecing together a number of recent experimental observations and insights obtained from 1D and 2D simulation models. Different roles played by diamagnetic mean flow, neoclassical-driven mean flow, turbulence-driven mean flow, and turbulence-driven zonal flows are discussed and clarified. It is found that the L-H transition occurs spontaneously mediated by a shift in the radial wavenumber spectrum of edge turbulence, which provides a critical evidence for the theory of turbulence quench by the flow shear. Remaining questions and some key directions for future investigations are proposed. This work was supported by National Magnetic Confinement Fusion Science Program of China under Contracts No. 2015GB101000, No. 2013GB106000, and No. 2013GB107000 and National Natural Science Foundation of China under Contracts No. 11575235 and No. 11422546.

  13. Inhibition of Follicle-Stimulating Hormone-Induced Preovulatory Follicles in Rats Treated with a Nonsteroidal Negative Allosteric Modulator of Follicle-Stimulating Hormone Receptor1

    OpenAIRE

    Dias, James A.; Campo, Brice; Weaver, Barbara A.; Watts, Julie; Kluetzman, Kerri; Thomas, Richard M.; Bonnet, Béatrice; Mutel, Vincent; Poli, Sonia M.

    2013-01-01

    We previously described a negative allosteric modulator (NAM) of FSHR (ADX61623) that blocked FSH-induced cAMP and progesterone production but did not block estradiol production. That FSHR NAM did not affect FSH-induced preovulatory follicle development as evidenced by the lack of an effect on the number of FSH-dependent oocytes found in the ampullae following ovulation with hCG. A goal is the development of a nonsteroidal contraceptive. Toward this end, a high-throughput screen using human F...

  14. Comparison of L-H transition measurements with physics models

    International Nuclear Information System (INIS)

    Carlstrom, T.N.; Burrell, K.H.; Carreras, B.A.

    1999-01-01

    Sawteeth and neutrals are found to have a significant influence on the H-mode power threshold scaling. The ion ∇B drift direction has only a small effect on the edge plasma conditions measured near the plasma midplane but a large effect on the divertor plasma. Since the power threshold changes dramatically with the direction of the ion ∇B drift, this implies that phenomena in the divertor region are critical for the L-H transition. Local conditions at the plasma edge are consistent with several theories of the L-H transition that use edge gradients in their formulation of a critical threshold parameter. However, scatter in the database is too large to distinguish between conditions that lead to an L-H transition and those that remain in L-mode. (author)

  15. Comparison of L-H transition measurements with physics models

    International Nuclear Information System (INIS)

    Carlstrom, T.N.; Burrell, K.H.; Groebner, R.J.

    2001-01-01

    Sawteeth and neutrals are found to have a significant influence on the H-mode power threshold scaling. The ion ∇B drift direction has only a small effect on the edge plasma conditions measured near the plasma midplane but a large effect on the divertor plasma. Since the power threshold changes dramatically with the direction of the ion ∇B drift, this implies that phenomena in the divertor region are critical for the L-H transition. Local conditions at the plasma edge are consistent with several theories of the L-H transition that use edge gradients in their formulation of a critical threshold parameter. However, scatter in the database is too large to distinguish between conditions that lead to an L-H transition and those that remain in L-mode. (author)

  16. LH-power coupling in advanced tokamak plasmas in JET

    International Nuclear Information System (INIS)

    Joffrin, E.; Erents, K.; Gormezano, C.

    2000-02-01

    Lower Hybrid Current Drive (LHCD) is the most efficient tool to generate non-inductive current in tokamak plasmas. In JET, significant modifications of the current profile have been recently achieved in coupling up to 3MW of LH power in optimised shear discharges. However, the improved particle confinement during optimised shear plasmas results in a sharp decrease of the electron density in front the launcher close or below the cut-off density (ne=1.7.10 17 m -3 for f LH =37GHz) and makes difficult the coupling of the LH power. Deuterium gas near the launcher can help to improve the coupling, but has also the effect of increasing the ELM activity leading to the erosion of the internal transport barrier (ITB). Future development of lower hybrid launcher should include the constraints imposed by scenario such as the optimised shear. (author)

  17. Coastal Storm Surge Analysis: Storm Surge Results. Report 5: Intermediate Submission No. 3

    Science.gov (United States)

    2013-11-01

    Vickery, P., D. Wadhera, A. Cox, V. Cardone , J. Hanson, and B. Blanton. 2012. Coastal storm surge analysis: Storm forcing (Intermediate Submission No...CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Jeffrey L. Hanson, Michael F. Forte, Brian Blanton

  18. Quick look report for Semiscale Mod-2C experiments S-LH-1 and S-LH-2

    International Nuclear Information System (INIS)

    Loomis, G.G.; Streit, J.E.

    1985-05-01

    Results from a preliminary analysis of Semiscale Tests S-LH-1 and S-LH-2 are presented. Both experiments were 5%, cold leg, centerline pipe break, loss-of-coolant accident simulations with only the downcomer to upper head bypass flow different. Test S-LH-1 had a bypass flow of 0.9% of core flow and Test S-LH-2 had a 3% bypass flow. Phenomena of interest included two core liquid level depressions with minor core rod temperature excursions. The first liquid level depression was induced by a manometric balance formed by a liquid seal in the pump suctions of both loops and the second level depletion was due to core liquid boiloff. Pump suction seal clearing mitigated the first core heatup and accumulator flow refilled the core to terminate the second core heatup. Comparisons are made between a pretest RELAP5 calculation and S-LH-1 data. RELAP5 calculated the manometric core level depression but not the core rod heatups

  19. Application of ovine luteinizing hormone (LH) radioimmunoassay in the quantitation of LH in different mammalian species. [/sup 125/I tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Millar, R.P.; Aehnelt, C.

    1977-09-01

    A sensitive double antibody radioimmunoassay has been developed for measuring luteinizing hormone (LH) in various African mammalian species, using rabbit anti-ovine LH serum (GDN 15) and radioiodinated rat LH or ovine LH. Serum and pituitary homogenates from some African mammals (hyrax, reedbuck, sable, impala, tsessebe, thar, spring-hare, ground squirrel and cheetah, as well as the domestic sheep, cow and horse and laboratory rat and hamster) produced displacement curves parallel to that of the ovine LH standards. The specificity of the assay was examined in detail for one species, the rock hyrax. Radioimmunoassay and bioassay estimates of LH in hyrax pituitaries containing widely differing quantities of pituitary hormones were similar. In sexually active male hyrax mean plasma LH was 12.1 ng/ml and pituitary LH 194 ..mu..g/gland, but in sexually quiescent hyrax mean plasma LH was 2.4 ng/ml and mean pituitary LH 76 ..mu..g/gland. Intravenous injection of 10 ..mu..g of luteinizing hormone releasing hormone increased mean LH levels in hyrax from 0.9 ng/ml to 23.2 ng/ml by 30 min. Conversely, im injection of 250 ..mu..g testosterone induced a fall in LH levels in male hyrax from 1.7 ng/ml to 0.7 ng/ml 6 h after administration. Although the specificity of the assay for quantitating plasma LH in other species was not categorically established, there was a good correlation between plasma LH concentration and reproductive state in the bontebok, impala, spring-hare, thar, cheetah, domestic horse and laboratory rat, suggesting the potential use of the antiserum in quantitating LH in a variety of mammalian species.

  20. Compressor Surge Control Design Using Linear Matrix Inequality Approach

    OpenAIRE

    Uddin, Nur; Gravdahl, Jan Tommy

    2017-01-01

    A novel design for active compressor surge control system (ASCS) using linear matrix inequality (LMI) approach is presented and including a case study on piston-actuated active compressor surge control system (PAASCS). The non-linear system dynamics of the PAASCS is transformed into linear parameter varying (LPV) system dynamics. The system parameters are varying as a function of the compressor performance curve slope. A compressor surge stabilization problem is then formulated as a LMI probl...

  1. Flow in sodium loop surge tank

    International Nuclear Information System (INIS)

    Matal, O.; Martoch, J.

    1977-01-01

    The alternate liquid flow, the condition of vortex formation, gas entrainment in the discharge and the liquid level characteristics are studied using the models of the vertical and horizontal surge tanks of a sodium circuit with pump and heat exchangers. The conditions for vortex formation are more favourable in the vertical cylindrical tank than in the horizontal tank. The size of the vortex produced in the tank is affected by the initial speed circulation, due as a rule to an unsuitable inlet design. The proposed design considers an inlet below the sodium level using capped perforated pipes. Vortex formation, gas transport to the discharge pipe and turbulences of the liquid in the tank may be prevented by dividing the tank to the discharge and the inlet areas using perforated partitions, and by inserting the discharge cylinder above the discharge pipe outflow. The liquid level in the tank may be calmed by screens or by perforated plates. The adaptation of the surge tank of the sodium circuit will probably eliminate vortex formation and the entrainment of cover gas into the discharge piping and the sodium circuit under nominal conditions. (J.B.)

  2. Pretest analysis document for Semiscale Test S-LH-1

    International Nuclear Information System (INIS)

    Shaw, R.A.

    1985-03-01

    Results from various pretest calculations which were performed for Test S-LH-1 are included in this report. Test S-LH-1 has been designed to produce primary liquid holdup in the steam generator U-tubes similar to Tests S-UT-8. The analyses included in this report indicate liquid will be held in the tubes, the core liquid level will be appropriately depressed, and a core heater rod temperature excursion should occur. Several sensitivity studies are also included which identify parameters which could affect the response

  3. Comparison of L-H transition measurements with physics models

    International Nuclear Information System (INIS)

    Carlstrom, T.N.; Burrell, K.H.; Groebner, R.J.; Leonard, A.W.; Osborne, T.H.; Thomas, D.M.

    1998-12-01

    A technique of fitting a modified hyperbolic tangent to the edge profiles has improved the localization of plasma edge parameters. Non-dimensional edge parameters are broadly consistent with several theories of the L-H transition that use edge gradients in their formulation of a critical threshold parameter. The ion ∇B drift direction has only a small effect on the edge plasma conditions measured near the plasma midplane but a large effect on the divertor plasma. The dramatic change of power threshold with the direction of the ion ∇B drift implies that phenomena in the divertor region may be critical for the L-H transition

  4. [The lh-rh-test in men with fertility disorders (author's transl)].

    Science.gov (United States)

    Krause, W; Höbel, W

    1976-11-01

    89 mal patients with fertility disorders underwent a test with 50 mug synthetic LH-RH. The basal levels of FSH and LH are elevated in patients with azoospermia, with testicular atrophy, varicocele and Klinefelters syndrome. They increase with age. After stimulation with LH-RH the highest relative peaks (maximal value divided by control value) of LH are seen younger patients, in those with varicocele, and oligozoospermia. The FSH-values do not differ significantly between these groups. Low relative peaks of LH are seen in older patients. In Klinefelter's syndrome the relative peaks of FSH and LH are significantly lowered.

  5. Tide-surge interaction in the English Channel

    Directory of Open Access Journals (Sweden)

    D. Idier

    2012-12-01

    Full Text Available The English Channel is characterised by strong tidal currents and a wide tidal range, such that their influence on surges is expected to be non-negligible. In order to better assess storm surges in this zone, tide-surge interactions are investigated. A preliminary data analysis on hourly surges indicates some preferential times of occurrence of large storm surges at rising tide, especially in Dunkerque. To examine this further, a numerical modelling approach is chosen, based on the 2DH shallow-water model (MARS. The surges are computed both with and without tide interaction. For the two selected events (the November 2007 North Sea and March 2008 Atlantic storms, it appears that the instantaneous tide-surge interaction is seen to be non-negligible in the eastern half of the English Channel, reaching values of 74 cm (i.e. 50% of the same event maximal storm surge in the Dover Strait for the studied cases. This interaction decreases in westerly direction. In the risk-analysis community in France, extreme water levels have been determined assuming skew surges and tide as independent. The same hydrodynamic model is used to investigate this dependence in the English Channel. Simple computations are performed with the same meteorological forcing, while varying the tidal amplitude, and the skew surge differences DSS are analysed. Skew surges appear to be tide-dependent, with negligible values of DSS (<0.05 m over a large portion of the English Channel, although reaching several tens of centimetres in some locations (e.g. the Isle of Wight and Dover Strait.

  6. Risk Assessment and Scaling for the SLS LH2 ET

    Science.gov (United States)

    Hafiychuk, Halyna; Ponizovskaya-Devine, Ekaterina; Luchinsky, Dmitry; Khasin, Michael; Osipov, Viatcheslav V.; Smelyanskiy, Vadim N.

    2012-01-01

    In this report the main physics processes in LH2 tank during prepress and rocket flight are studied. The goal of this investigation is to analyze possible hazards and to make risk assessment in proposed LH2 tank designs for SLS with 5 engines (the situation with 4 engines is less critical). For analysis we use the multinode model (MNM) developed by us and presented in a separate report and also 3D ANSYS simulations. We carry out simulation and theoretical analysis the physics processes such as (i) accumulation of bubbles in LH2 during replenish stage and their collapsing in the liquid during the prepress; (ii) condensation-evaporation at the liquid-vapor interface and tank wall, (iv) heating the liquid near the interface and wall due to condensation and environment heat, (v) injection of hot He during prepress and of hot GH2 during flight, (vi) mixing and cooling of the injected gases due to heat transfer between the gases, liquid and the tank wall. We analyze the effects of these physical processes on the thermo- and fluid gas dynamics in the ullage and on the stratification of temperature in the liquid and assess the associated hazards. A special emphasize is put on the scaling predictions for the larger SLS LH2 tank.

  7. High Specific Power Motors in LN2 and LH2

    Science.gov (United States)

    Brown, Gerald V.; Jansen, Ralph H.; Trudell, Jeffrey J.

    2007-01-01

    A switched reluctance motor has been operated in liquid nitrogen (LN2) with a power density as high as that reported for any motor or generator. The high performance stems from the low resistivity of Cu at LN2 temperature and from the geometry of the windings, the combination of which permits steady-state rms current density up to 7000 A/sq cm, about 10 times that possible in coils cooled by natural convection at room temperature. The Joule heating in the coils is conducted to the end turns for rejection to the LN2 bath. Minimal heat rejection occurs in the motor slots, preserving that region for conductor. In the end turns, the conductor layers are spaced to form a heat-exchanger-like structure that permits nucleate boiling over a large surface area. Although tests were performed in LN2 for convenience, this motor was designed as a prototype for use with liquid hydrogen (LH2) as the coolant. End-cooled coils would perform even better in LH2 because of further increases in copper electrical and thermal conductivities. Thermal analyses comparing LN2 and LH2 cooling are presented verifying that end-cooled coils in LH2 could be either much longer or could operate at higher current density without thermal runaway than in LN2.

  8. Cost Beneftt Analysts of LH2 PadB

    Science.gov (United States)

    Mott, Brittany

    2013-01-01

    This analysis is used to evaluate, from a cost and benefit perspective, potential outcomes when replacing the pressurization switches and the pressurization system to meet the needs of the LH2 storage system at Pad B. This also includes alternatives, tangible and intangible benefits, and the results of the analysis.

  9. Astronomy. ASASSN-15lh: A highly super-luminous supernova.

    Science.gov (United States)

    Dong, Subo; Shappee, B J; Prieto, J L; Jha, S W; Stanek, K Z; Holoien, T W-S; Kochanek, C S; Thompson, T A; Morrell, N; Thompson, I B; Basu, U; Beacom, J F; Bersier, D; Brimacombe, J; Brown, J S; Bufano, F; Chen, Ping; Conseil, E; Danilet, A B; Falco, E; Grupe, D; Kiyota, S; Masi, G; Nicholls, B; Olivares E, F; Pignata, G; Pojmanski, G; Simonian, G V; Szczygiel, D M; Woźniak, P R

    2016-01-15

    We report the discovery of ASASSN-15lh (SN 2015L), which we interpret as the most luminous supernova yet found. At redshift z = 0.2326, ASASSN-15lh reached an absolute magnitude of Mu ,AB = -23.5 ± 0.1 and bolometric luminosity Lbol = (2.2 ± 0.2) × 10(45) ergs s(-1), which is more than twice as luminous as any previously known supernova. It has several major features characteristic of the hydrogen-poor super-luminous supernovae (SLSNe-I), whose energy sources and progenitors are currently poorly understood. In contrast to most previously known SLSNe-I that reside in star-forming dwarf galaxies, ASASSN-15lh appears to be hosted by a luminous galaxy (MK ≈ -25.5) with little star formation. In the 4 months since first detection, ASASSN-15lh radiated (1.1 ± 0.2) × 10(52) ergs, challenging the magnetar model for its engine. Copyright © 2016, American Association for the Advancement of Science.

  10. Radioimmunological measurements of total LH in sheep pituitary cells

    International Nuclear Information System (INIS)

    McIntosh, R.P.; McIntosh, J.E.A.

    1983-01-01

    Procedures commonly used to extract LH from pituitary cells in order to measure total cell content were compared in four cell preparations. It was shown in 81 samples of cells suspended in 1 mM EDTA or 50 mM NaHCO 3 that after freezing and thawing folloqwed by any of a variety of treatments, there were no significant differences in the amounts of LH measured by RIA relative to the arbitrarily chosen reference treatment of vigorous pipetting. The additional treatments were multiple freezing and thawing, homogenisation, sonication, homogenisation in 25-100 mM Na 2 CO 3 folloqwed by rapid neutralisation, or none. The consistency of the results suggested that the same cellular pools of LH were being made accessible for measurement with all treatments. However, use of the more vigorous conditions of 1-2.5 M urea, 1% Triton X-100, or sonication on ice in 100 mM Na 2 CO 3 decreased the amount of measurable hormone presumably due to its modification. In two cell preparations, homogenisation of cells in 100 mM Na 2 CO 3 produced and additional 45% of measurable LH not accessible using other treatments nor from the source material in two other preparations. (author)

  11. Separation of prostaglandin metabolites on sephadex LH 20 columns

    DEFF Research Database (Denmark)

    Hansen, Harald S.; Bukhave, K.

    1978-01-01

    Sephadex LH 20 columns have been investigated for the separation of initial prostaglandin metabolites. Solvent systems are described for the separation of the free acids of 15-keto-dihydro-PGE, 15-keto-PGE, PGE, and PGF(1a). Further, one of the solvent systems is described for the separation...

  12. Fast change in core transport after L-H transition

    International Nuclear Information System (INIS)

    Kadomtsev, B.B.; Itoh, K.; Itoh, S.

    1995-03-01

    The transport in the core tokamak plasma is known to change very rapidly after the L-H transition in the edge plasma. A qualitative discussion is given for this fast transmission of the transport change. A picture based on the successive bifurcations is presented. (author)

  13. Will oscillating wave surge converters survive tsunamis?

    Directory of Open Access Journals (Sweden)

    L. O’Brien

    2015-07-01

    Full Text Available With an increasing emphasis on renewable energy resources, wave power technology is becoming one of the realistic solutions. However, the 2011 tsunami in Japan was a harsh reminder of the ferocity of the ocean. It is known that tsunamis are nearly undetectable in the open ocean but as the wave approaches the shore its energy is compressed, creating large destructive waves. The question posed here is whether an oscillating wave surge converter (OWSC could withstand the force of an incoming tsunami. Several tools are used to provide an answer: an analytical 3D model developed within the framework of linear theory, a numerical model based on the non-linear shallow water equations and empirical formulas. Numerical results show that run-up and draw-down can be amplified under some circumstances, leading to an OWSC lying on dry ground!

  14. [Construction and Characterization of B850-Only LH2 Energy Transfer System in Purple Bacteria].

    Science.gov (United States)

    Li, Kai; Zhao, Chun-gui; Yue, Hui-ying; Yang, Su-ping; Qu, Yin-bo; Jiao, Nian-zhi

    2015-04-01

    To seek microscopic molecular mechanism of energy transfer and complex reconstitution in the photosynthesis, the conditions for construction of B850-only peripheral light-harvesting complex (LH2) and their properties were investigated using absorption, fluorescence spectroscopy, molecular sieve chromatography, ultrafiltration and sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) from the purple bacteria. The results indicated that bacteriochlorophylls (BChl) of B800 incubated in 10 mmo · L(-1) Tris-HCl (pH 8.0) buffer are selectively released from their binding sites of LH2 of Rhodobacter azotoformans (A-LH2) by 0.08% (W/V) SDS. B850-only A-LH2 was constructed after removing free BChl mixing with 10% methyl alcohol by ultrafiltration. B850 BChl was released after A-LH2 was incubated for 240 min in dark at room temperature (RT). While BChl of B800 incubated in pH 1.9 buffer were selectively released from their binding sites of LH2 of Rhodopseudomonas palustris (P-LH2). The authors acquired two components using molecular sieve chromatography. Free BChl of one component was not removed and self-assembled to P-LH2. The other removed free BChl and B850-only P-LH2 was constructed. B850 unchanged after P-LH2 was incubated. P-LH2 α and β subunits have different molecular weights, but those of A-LH2 are in the contrary. It is concluded that B850-only P-LH2 is more stable than A-LH2. The enigmatic split of the B800 absorption band was not observed in these LH2, but we acquired two kinds of B800-released LH2 from Rhodopseudomonas palustris. The authors' results may provide a new light to separate homogeneous Apoprotein LH2.

  15. Anchored LH2 complexes in 2D polarization imaging.

    Science.gov (United States)

    Tubasum, Sumera; Sakai, Shunsuke; Dewa, Takehisa; Sundström, Villy; Scheblykin, Ivan G; Nango, Mamoru; Pullerits, Tõnu

    2013-09-26

    Protein is a soft material with inherently large structural disorder. Consequently, the bulk spectroscopies of photosynthetic pigment protein complexes provide averaged information where many details are lost. Here we report spectroscopy of single light-harvesting complexes where fluorescence excitation and detection polarizations are both independently rotated. Two samples of peripheral antenna (LH2) complexes from Rhodopseudomonas acidophila were studied. In one, the complexes were embedded in polyvinyl alcohol (PVA) film; in the other, they were anchored on the glass surface and covered by the PVA film. LH2 contains two rings of pigment molecules-B800 and B850. The B800 excitation polarization properties of the two samples were found to be very similar, indicating that orientation statistics of LH2s are the same in these two very different preparations. At the same time, we found a significant difference in B850 emission polarization statistics. We conclude that the B850 band of the anchored sample is substantially more disordered. We argue that both B800 excitation and B850 emission polarization properties can be explained by the tilt of the anchored LH2s due to the spin-casting of the PVA film on top of the complexes and related shear forces. Due to the tilt, the orientation statistics of two samples become similar. Anchoring is expected to orient the LH2s so that B850 is closer to the substrate. Consequently, the tilt-related strain leads to larger deformation and disorder in B850 than in B800.

  16. Energy exchange dynamics across L-H transitions in NSTX

    Science.gov (United States)

    Diallo, A.; Banerjee, S.; Zweben, S. J.; Stoltzfus-Dueck, T.

    2017-06-01

    We studied the energy exchange dynamics across the low-to-high-confinement (L-H) transition in NSTX discharges using the gas-puff imaging (GPI) diagnostic. The investigation focused on the energy exchange between flows and turbulence to help clarify the mechanism of the L-H transition. We applied this study to three types of heating schemes, including a total of 17 shots from the NSTX 2010 campaign run. Results show that the edge fluctuation characteristics (fluctuation levels, radial and poloidal correlation lengths) measured using GPI do not vary just prior to the H-mode transition, but change after the transition. Using a velocimetry approach (orthogonal-dynamics programming), velocity fields of a 24× 30 cm GPI view during the L-H transition were obtained with good spatial (˜1 cm) and temporal (˜2.5 μs) resolutions. Analysis using these velocity fields shows that the production term is systematically negative just prior to the L-H transition, indicating a transfer from mean flows to turbulence, which is inconsistent with the predator-prey paradigm. Moreover, the inferred absolute value of the production term is two orders of magnitude too small to explain the observed rapid L-H transition. These discrepancies are further reinforced by consideration of the ratio between the kinetic energy in the mean flow to the thermal free energy, which is estimated to be much less than 1, suggesting again that the turbulence depletion mechanism may not play an important role in the transition to the H-mode. Although the Reynolds work therefore appears to be too small to directly deplete the turbulent free energy reservoir, order-of-magnitude analysis shows that the Reynolds stress may still make a non-negligible contribution to the observed poloidal flows.

  17. Production and Characterization of Anti-LH Polyclonal Antibodies for Establishment of Sepharose Solid Phase Radioimmunoassay

    International Nuclear Information System (INIS)

    Ebeid, N.H.; Mehany, N.L.

    2016-01-01

    The present study was designed to achieve the production and characterization of polyclonal antibody of luteinizing hormone (Anti-LH) as a basic component of LH radioimmunoassay (RIA). The main objective was to improve the immunogenicity of LH by conjugation of LH with bovine serum albumin (LH: BSA) as a protein carrier using Ethyl dimethylaminopropyl Carbodiimide (ECDI). Production of Anti-LH was described where LH : BSA immunogen was immunized into three male mature white New-Zealand rabbits through primary immunization and four boosters. The criteria for selecting LH antiserum for liquid phase RIA system were mainly titer, displacement and immuno response profile and followed by partial purification of IgG-LH. The radioiodinated 125 I-LH tracer was carried out using Chloramine-T as an oxidizing agent and the tracer was purified through PD-10 column. The preparation of LH standards was carried out. Coupling of purified IgG-LH to activated Sepharose particles CL-4B was carried out after activation of Sepharose particles with 1,1-carbonyldiimidazole. Extensive studies were carried out to obtain the optimum conditions of using solid phase Sepharose particles to reach the optimum separation efficiency. The results of validation tests revealed that the local solid phase RIA system is precise and accurate to detect LH concentration in human serum to be used as a diagnostic tool in investigating the infertility in the hypothalamic pituitary gonadal disorders

  18. Overview and Design Considerations of Storm Surge Barriers

    NARCIS (Netherlands)

    Mooyaart, L.F.; Jonkman, S.N.

    2017-01-01

    The risk of flooding in coastal zones is expected to increase due to sea level rise and economic development. In larger bays, estuaries, and coastal waterways, storm surge barriers can be constructed to temporarily close off these systems during storm surges to provide coastal flood protection.

  19. Using satellite altimetry and tide gauges for storm surge warning

    DEFF Research Database (Denmark)

    Andersen, O. B.; Cheng, Yongcun; Deng, X.

    2014-01-01

    of Australia. For both locations we have tried to investigate the possibilities and limitations of the use of satellite altimetry to capture high frequency signals (surges) using data from the past 20 years. The two regions are chosen to represent extra-tropical and tropical storm surge conditions. We have...

  20. Study of storm surge trends in typhoon-prone coastal areas based on observations and surge-wave coupled simulations

    Science.gov (United States)

    Feng, Xingru; Li, Mingjie; Yin, Baoshu; Yang, Dezhou; Yang, Hongwei

    2018-06-01

    This is a study of the storm surge trends in some of the typhoon-prone coastal areas of China. An unstructured-grid, storm surge-wave-tide coupled model was established for the coastal areas of Zhejiang, Fujian and Guangdong provinces. The coupled model has a high resolution in coastal areas, and the simulated results compared well with the in situ observations and satellite altimeter data. The typhoon-induced storm surges along the coast of the study areas were simulated based on the established coupled model for the past 20 years (1997-2016). The simulated results were used to analyze the trends of the storm surges in the study area. The extreme storm surge trends along the central coast of Fujian Province reached up to 0.06 m/y, significant at the 90% confidence level. The duration of the storm surges greater than 1.0 and 0.7 m had an increasing trend along the coastal area of northern Fujian Province, significant at confidence levels of 70%-91%. The simulated trends of the extreme storm surges were also validated by observations from two tide gauge stations. Further studies show that the correlation coefficient (RTE) between the duration of the storm surge greater than 1 m and the annual ENSO index can reach as high as 0.62, significant at the 99% confidence level. This occurred in a location where the storm surge trend was not significant. For the areas with significant increasing storm surge trends, RTE was small and not significant. This study identified the storm surge trends for the full complex coastline of the study area. These results are useful both for coastal management by the government and for coastal engineering design.

  1. Direct visualization of exciton reequilibration in the LH1 and LH2 complexes of Rhodobacter sphaeroides by multipulse spectroscopy.

    Science.gov (United States)

    Cohen Stuart, Thomas A; Vengris, Mikas; Novoderezhkin, Vladimir I; Cogdell, Richard J; Hunter, C Neil; van Grondelle, Rienk

    2011-05-04

    The dynamics of the excited states of the light-harvesting complexes LH1 and LH2 of Rhodobacter sphaeroides are governed, mainly, by the excitonic nature of these ring-systems. In a pump-dump-probe experiment, the first pulse promotes LH1 or LH2 to its excited state and the second pulse dumps a portion of the excited state. By selective dumping, we can disentangle the dynamics normally hidden in the excited-state manifold. We find that by using this multiple-excitation technique we can visualize a 400-fs reequilibration reflecting relaxation between the two lowest exciton states that cannot be directly explored by conventional pump-probe. An oscillatory feature is observed within the exciton reequilibration, which is attributed to a coherent motion of a vibrational wavepacket with a period of ∼150 fs. Our disordered exciton model allows a quantitative interpretation of the observed reequilibration processes occurring in these antennas. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  2. Harmful effects of lightning surge discharge on communications terminal equipments

    International Nuclear Information System (INIS)

    Liang, Sisi; Xu, Xiaoying; Tao, Zhigang; Dai, Yanling

    2013-01-01

    The interference problem of lightning surges on electronic and telecommunication products were examined, and a series of experiments were conducted to analyze the failure situations to find out the mechanisms of failures caused by the lightning surge. In addition, the ways in which lightning surges damaged equipment were deduced. It was found that failure positions were scattered and appeared in groups, and most of them were ground discharge. Internet access transformer had high withstand-voltage under the lightning pulse, and the lightning surge seldom passed through the internet access transformer. The lightning current can release to the ground via the computer network adapter of the terminal user. The study will help to improve the performance of lightning surge protection circuit and protection level.

  3. EFFECT TN EWES OF OESTROGEN PRIMING AND GnRH ON LH ...

    African Journals Online (AJOL)

    Cyclicvariationsintheincreasedresponsivenessof thepituitaryto luteinizing hormone-releasing hormone ( LH RH) induced by LHRH . Endocrinology 9l , 13. COPPINGS, R.J. & MALVEN, P.V.. 1976. Biphasic effect of oestradiol on LH release mechanisms.

  4. The usefulness of serum LH radioimmunoassay in the diagnosis of male hypogonadism

    International Nuclear Information System (INIS)

    Sobieszczyk, S.

    1975-01-01

    Serum LH was determined in a group of 56 males with gandal insufficiency. In this group were included 20 cases of Klinefelter's syndronme, 14 patients with total anterior pituitary insufficiency and 22 patients with eunuchoidism. Serum LH was also performed in a group of 50 healthy men. In the presented studies the LH radioimmunoassay with double antibodies was applied. In most cases of Klinefelter's syndrome the concentration of LH in serum was increased but in four subjects was normal. In total hypopituitarism serum LH was undetectable. Among patients with eunuchoidism the results of serum LH concentrations were different. Three cases with anorchia as well as four patients with testicular atrophy had elevated serum LH. In the other fifteen subjects serum LH was undetectable; hypogonadotropic eunuchoidism was diagnosed in these patients. (author)

  5. Human fetal antehypophysis in vitro. Immunocytological study and radioimmunoassay of LH and FSH

    International Nuclear Information System (INIS)

    Li, J.Y.; Begeot, M.; Dubois, P.M.; Claustrat, B.

    1977-01-01

    Human fetal antehypophysis (16 males, 16 females and 4 unknown sex) were cultivated during several weeks. By immunocytochemistry LH gonadotroph cells were determined with anti-hTSH and anti-pLH serum. The release in vitro of LH and FSH was studied by radioimmunoassay. At the first medium change, the quantity of LH and FSH release was related to the gestational age and sex. A rapid decline of both LH and FSH occured over the 10 first days. There after, a basal release of LH was maintained during several months; the release of FSH was generally maintained at the lower limit of the assay. After 1 month in vitro, the level of LH could not be related to the sex. Release of LH was stimulated by synthetic LRF. A significant increase was observed independently of the sex and age of the fetuses studied [fr

  6. Isolation and purification of porcine LH for radioimmunoassay and radioreceptor assay

    International Nuclear Information System (INIS)

    Ziecik, A.; Goralska, M.; Krzymowski, T.; Pogorzelski, K.

    1979-01-01

    The procedure of isolation and purification of LH from porcine pituitary glands is described. From 1 kg of pituitary glands 150 mg of LH GPZ-1 preparation of high purity were obtained. Immunization of rabbits with the prepared hormone gave homogeneous antibodies against porcine LH with high affinity and low cross-reactions with FSH. Radioreceptor assay with the use of the prepared porcine LH demonstrated the high capacity of cell membrane receptors of the boar tests for binding this hormone. (author)

  7. Storm Surge and Tide Interaction: A Complete Paradigm

    Science.gov (United States)

    Horsburgh, K.

    2014-12-01

    Estimates show that in 2005, in the largest 136 coastal cities, there were 40 million people and 3,000 billion of assets exposed to 1 in 100 year coastal flood events. Mean sea level rise will increase this exposure to 150 million people and 35,000 billion of assets by 2070. Any further change in the statistics of flood frequency or severity would impact severely on economic and social systems. It is therefore crucial to understand the physical drivers of extreme storm surges, and to have confidence in datasets used for extreme sea level statistics. Much previous research has focussed on the process of tide-surge interaction, and it is now widely accepted that the physical basis of tide-surge interaction is that a phase shift of the tidal signal represents the effect of the surge on the tide. The second aspect of interaction is that shallow water momentum considerations imply that differing tidal states should modulate surge generation: wind stress should have greater surge-generating potential on lower tides. We present results from a storm surge model of the European shelf that demonstrate that tidal range does have an effect on the surges generated. The cycle-integrated effects of wind stress (i.e. the skew surge) are greater when tidal range is low. Our results contradict the absence of any such correlation in tide gauge records. This suggests that whilst the modulating effect of the tide on the skew surge (the time-independent difference between peak prediction and observations) is significant, the difference between individual storms is dominant. This implies that forecasting systems must predict salient detail of the most intense storms. A further implication is that flood forecasting models need to simulate tides with acceptable accuracy at all coastal locations. We extend our model analysis to show that the same modulation of storm surges (by tidal conditions) applies to tropical cyclones. We conduct simulations using a mature operational storm surge model

  8. Suboptimal response to GnRHa long protocol is associated with a common LH polymorphism

    DEFF Research Database (Denmark)

    Alviggi, C; Clarizia, R; Pettersson, K

    2011-01-01

    The aim of this observational preliminary trial was to estimate the association between the most common polymorphism of LH (LH-β variant: v-βLH), with different profiles of ovarian response to recombinant human FSH (rhFSH). A total of 60 normogonadotrophic patients undergoing a gonadotrophin-rele...

  9. Both recombinant African catfish LH and FSH are able to activate the African catfish FSH receptor

    NARCIS (Netherlands)

    Vischer, HF; Granneman, JCM; Linskens, MHK; Schulz, RW; Bogerd, J

    LH and FSH are heterodimeric glycoprotein hormones, composed of a common alpha-subunit non-covalently associated with a hormone-specific beta-subunit. Repeated efforts to isolate catfish FSH (cfFSH) have not been successful and only catfish LH (cfLH) has been purified from catfish pituitaries.

  10. Distribution of rhodopin and spirilloxanthin between LH1 and LH2 complexes when incorporating carotenoid mixture into the membrane of purple sulfur bacterium Allochromatium minutissimum in vitro.

    Science.gov (United States)

    Bolshakov, M A; Ashikhmin, A A; Makhneva, Z K; Moskalenko, A A

    2016-11-01

    Carotenoid mixture enriched by rhodopin and spirilloxanthin was incorporated in LH2 and LH1 complexes from Allochromatium (Alc.) minutissimum in vitro. The maximum incorporating level was ~95%. Rhodopin (56.4%) and spirilloxanthin (13.8%) were incorporated into the LH1 complex, in contrast to the control complex, which contained primarily spirilloxanthin (66.8%). After incorporating, the LH2 complex contained rhodopin (66.7%) and didehydrorhodopin (14.6%), which was close to their content in the control (67.4 and 20.5%, respectively). Thus, it was shown that carotenoids from the total pool are not selectively incorporated into LH2 and LH1 complexes in vitro in the proportion corresponding to the carotenoid content in the complexes in vivo.

  11. Surge dynamics on Bering Glacier, Alaska, in 2008–2011

    Directory of Open Access Journals (Sweden)

    M. Braun

    2012-11-01

    Full Text Available A surge cycle of the Bering Glacier system, Alaska, is examined using observations of surface velocity obtained using synthetic aperture radar (SAR offset tracking, and elevation data obtained from the University of Alaska Fairbanks LiDAR altimetry program. After 13 yr of quiescence, the Bering Glacier system began to surge in May 2008 and had two stages of accelerated flow. During the first stage, flow accelerated progressively for at least 10 months and reached peak observed velocities of ~ 7 m d−1. The second stage likely began in 2010. By 2011 velocities exceeded 9 m d−1 or ~ 18 times quiescent velocities. Fast flow continued into July 2011. Surface morphology indicated slowing by fall 2011; however, it is not entirely clear if the surge is yet over. The quiescent phase was characterized by small-scale acceleration events that increased driving stresses up to 70%. When the surge initiated, synchronous acceleration occurred throughout much of the glacier length. Results suggest that downstream propagation of the surge is closely linked to the evolution of the driving stress during the surge, because driving stress appears to be tied to the amount of resistive stress provided by the bed. In contrast, upstream acceleration and upstream surge propagation is not dependent on driving stress evolution.

  12. A replacement LH2 recirculation line before installation in Discovery

    Science.gov (United States)

    1999-01-01

    A spare four-inch diameter LH2 recirculation line (shown in photo) will be used to replace a damaged LH2 line in the orbiter Discovery. The line recirculates hydrogen from the Shuttle main engines back to the external tank during prelaunch engine conditioning. Workers noted a dent in the line during routine aft compartment inspections Tuesday, Dec. 7. The dent measures 12 inches long and about =-inch deep. Managers expect the replacement work to take about 3 days, followed by system retests and final aft compartment close-outs. Preliminary assessments reflect a launch date of Space Shuttle Discovery on mission STS-103 no earlier than Dec. 16. STS-103 is the third servicing mission for the Hubble Space Telescope.

  13. LOX/LH2 vane pump for auxiliary propulsion systems

    Science.gov (United States)

    Hemminger, J. A.; Ulbricht, T. E.

    1985-01-01

    Positive displacement pumps offer potential efficiency advantages over centrifugal pumps for future low thrust space missions. Low flow rate applications, such as space station auxiliary propulsion or dedicated low thrust orbiter transfer vehicles, are typical of missions where low flow and high head rise challenge centrifugal pumps. The positive displacement vane pump for pumping of LOX and LH2 is investigated. This effort has included: (1) a testing program in which pump performance was investigated for differing pump clearances and for differing pump materials while pumping LN2, LOX, and LH2; and (2) an analysis effort, in which a comprehensive pump performance analysis computer code was developed and exercised. An overview of the theoretical framework of the performance analysis computer code is presented, along with a summary of analysis results. Experimental results are presented for pump operating in liquid nitrogen. Included are data on the effects on pump performance of pump clearance, speed, and pressure rise. Pump suction performance is also presented.

  14. LO2/LH2 propulsion for outer planet orbiter spacecraft

    Science.gov (United States)

    Garrison, P. W.; Sigurdson, K. B.

    1983-01-01

    Galileo class orbiter missions (750-1500 kg) to the outer planets require a large postinjection delta-V for improved propulsion performance. The present investigation shows that a pump-fed low thrust LO2/LH2 propulsion system can provide a significantly larger net on-orbit mass for a given delta-V than a state-of-the-art earth storable, N2O4/monomethylhydrazine pressure-fed propulsion system. A description is given of a conceptual design for a LO2/LH2 pump-fed propulsion system developed for a Galileo class mission to the outer planets. Attention is given to spacecraft configuration, details regarding the propulsion system, the thermal control of the cryogenic propellants, and aspects of mission performance.

  15. Dual fluorescence of single LH2 antenna nanorings

    International Nuclear Information System (INIS)

    Freiberg, A.; Raetsep, M.; Timpmann, K.; Trinkunas, G.

    2004-01-01

    A dual nature of fluorescence from LH2 pigment-protein complexes, which is a part of the light harvesting system of purple bacteria, is confirmed by fluorescence-lifetime dependence on recording wavelength and spectrally selective spectroscopy. An analysis based on the Holstein molecular crystal model, modified by allowing diagonal disorder, suggests coexistence of large- and small-radius self-trapped excitons, which serve as the origin of the dual fluorescence

  16. Present dynamics and future prognosis of a slowly surging glacier

    Directory of Open Access Journals (Sweden)

    G. E. Flowers

    2011-03-01

    Full Text Available Glacier surges are a well-known example of an internal dynamic oscillation whose occurrence is not a direct response to the external climate forcing, but whose character (i.e. period, amplitude, mechanism may depend on the glacier's environmental or climate setting. We examine the dynamics of a small (∼5 km2 valley glacier in Yukon, Canada, where two previous surges have been photographically documented and an unusually slow surge is currently underway. To characterize the dynamics of the present surge, and to speculate on the future of this glacier, we employ a higher-order flowband model of ice dynamics with a regularized Coulomb-friction sliding law in both diagnostic and prognostic simulations. Diagnostic (force balance calculations capture the measured ice-surface velocity profile only when non-zero basal water pressures are prescribed over the central region of the glacier, coincident with where evidence of the surge has been identified. This leads to sliding accounting for 50–100% of the total surface motion in this region. Prognostic simulations, where the glacier geometry evolves in response to a prescribed surface mass balance, reveal a significant role played by a bedrock ridge beneath the current equilibrium line of the glacier. Ice thickening occurs above the ridge in our simulations, until the net mass balance reaches sufficiently negative values. We suggest that the bedrock ridge may contribute to the propensity for surges in this glacier by promoting the development of the reservoir area during quiescence, and may permit surges to occur under more negative balance conditions than would otherwise be possible. Collectively, these results corroborate our interpretation of the current glacier flow regime as indicative of a slow surge that has been ongoing for some time, and support a relationship between surge incidence or character and the net mass balance. Our results also highlight the importance of glacier bed

  17. China's electric car surge

    International Nuclear Information System (INIS)

    Wang, Yunshi; Sperling, Daniel; Tal, Gil; Fang, Haifeng

    2017-01-01

    China's plug-in electric vehicle (PEV) sales, comprising both battery electric and plug-in hybrid vehicles, surged 343% in 2015, and are expected to reach 2 million by 2020. Two factors are crucial to this sudden transformation: 1) massive central and local government subsidies, and 2) huge non-monetary incentives via exemptions from restrictions on vehicle ownership in Beijing, Shanghai, and elsewhere. Innovative business models and greatly expanded vehicle offerings, especially by local Chinese manufacturers, also helped accelerate PEV sales and infrastructure deployment. However, continued sales growth is threatened by persistent regional protectionism, the unsustainability of these large subsidies, and widely reported cheating by some automakers. We suggest some innovative policies that China might pioneer and transfer elsewhere. - Highlights: • The rapid growth was a result of massive central and local government subsidies. • Exemptions from restrictions on vehicle ownership play even more important role. • A comparative case study of Beijing and Shanghai. • Persistent regional protectionism impedes the development of China's PEV industry. • Focusing on the use of PEVs is a better way to achieve eVMT.

  18. LH Pretreatment as a Novel Strategy for Poor Responders

    Directory of Open Access Journals (Sweden)

    Anna Pia Ferraretti

    2014-01-01

    Full Text Available Introduction. Poor response to ovarian stimulation is still a major problem in IVF. The study presents a new stimulation protocol evaluated in a suppopulation of very difficult young poor ovarian responders. Material and Methods. The study consists in two sections. The first includes data from a randomized controlled study involving forty-three young patients with a poor ovarian response in at least two previous cycles (intended as cycle cancellation or with ≤3 collected oocytes. Patients were randomized in two groups: group A (control received FSH (400 IU/day, while group B received the new stimulation protocol consisting in a sequential association of 150 IU r-LH for 4 days followed by 400 IU r-FSH/after downregulation with daily GnRh agonist. The second includes data from the overall results in 65 patients treated with the new protocol compared to their previous performance with conventional cycles (historical control. Results. Both in the RCT and in the historical control study, LH pretreatment was able to decrease the cancellation rate, to improve the in vitro performance, and to significantly increase the live birth rates. Conclusions. LH pretreatment improved oocyte quantity and quality in young repeated poor responders selected in accordance with the Bologna criteria.

  19. Induction of Ski Protein Expression upon Luteinization in Rat Granulosa Cells

    Directory of Open Access Journals (Sweden)

    Hyun Kim

    2012-05-01

    Full Text Available Ski protein is implicated in proliferation/differentiation in a variety of cells. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells; however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to locate Ski protein in the rat ovary during luteinizationto predict the possible role of Ski. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rats, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone (LH surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of the corpus luteum (CL. Though Ski protein is absent in granulosa cells of preovulatory follicle, its mRNA (c-Ski was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggests that its expression is regulated post-transcriptionally.

  20. A simulation method for lightning surge response of switching power

    International Nuclear Information System (INIS)

    Wei, Ming; Chen, Xiang

    2013-01-01

    In order to meet the need of protection design for lighting surge, a prediction method of lightning electromagnetic pulse (LEMP) response which is based on system identification is presented. Experiments of switching power's surge injection were conducted, and the input and output data were sampled, de-noised and de-trended. In addition, the model of energy coupling transfer function was obtained by system identification method. Simulation results show that the system identification method can predict the surge response of linear circuit well. The method proposed in the paper provided a convenient and effective technology for simulation of lightning effect.

  1. Pressure-surge mitigation methods in fluid-conveying piping

    International Nuclear Information System (INIS)

    Shin, Y.W.; Youngdahl, C.K.; Wiedermann, A.H.

    1991-01-01

    Pressure surges in the heat transport system of nuclear reactor plants can affect the safety and reliability of the plants. Hence the pressure surges must be considered in the design, operation, and maintenance of the plants in order to minimize their occurrence and impacts. The objectives of this paper are to review various methods to control or mitigate the pressure surges, to analyze these methods to gain understanding of the mitigation mechanisms, and examine applicability of the methods to nuclear power plants. 6 refs., 13 figs

  2. Decreased expression of lysyl hydroxylase 2 (LH2) in skin fibroblasts from three Ehlers-Danlos patients does not result from mutations in either the coding or proximal promoter region of the LH2 gene.

    Science.gov (United States)

    Walker, L C; Teebi, A S; Marini, J C; De Paepe, A; Malfait, F; Atsawasuwan, P; Yamauchi, M; Yeowell, H N

    2004-12-01

    The Ehlers-Danlos syndromes (EDS) are a heterogeneous group of inherited connective tissue disorders characterized by tissue fragility, hyperelasticity of the skin and joint hypermobility. This phenotype, accompanied by kyphoscoliosis and/or ocular fragility, is present in patients with the autosomal recessive type VI form of EDS. These patients have significantly decreased levels of lysyl hydroxylase (LH) activity, due to mutations in the LH1 gene. LH hydroxylates specific lysine residues in the collagen molecule that are precursors for the formation of cross-links which provide collagen with its tensile strength. No disorder has been directly linked to decreased expression of LH2 and LH3, two other isoforms of LH. This study describes 3 patients with mixed phenotypes of EDS, who have significantly decreased mRNAs for LH2, but normal levels of LH1 and LH3 mRNAs, in their skin fibroblasts. In contrast to the effect of LH1 deficiency in EDS VI patients, the decreased expression of LH2 does not affect LH activity, bifunctional collagen cross-links (measured after reduction as dihydroxylysinonorleucine (DHLNL) and hydroxylysinonorleucine (HLNL)), or helical lysine hydroxylation in these cell lines. Sequence analysis of full length LH2 cDNAs and 1kb of the promoter region of LH2 does not show mutations that could explain the decreased expression of LH2. These results suggest that the deficiency of LH2 in these fibroblasts may be caused by changes in other factors required for the expression of LH2.

  3. Average concentrations of FSH and LH in seminal plasma as determined by radioimmunoassay

    International Nuclear Information System (INIS)

    Milbradt, R.; Linzbach, P.; Feller, H.

    1979-01-01

    In 322 males, 25 to 50 years of age, levels of LH and FSH respectively were determined in seminal plasma by radioimmunoassay. Average values of 0,78 ng/ml and 3,95 ng/ml were found as for FSH and LH respectively. Sperm count and motility were not related to FSH levels, but were to LH levels. A high count of spermatozoa corresponded to high concentration of LH, and normal motility was associated with higher levels of LH as compared to levels associated with asthenozoospermia. With respect to count of spermatozoa of a single or the average patient, it is suggested that the ratio of FSH/LH would be more meaningful than LH level alone. (orig.) [de

  4. Radioimmunologic assessment of the level of circulating LH antibodies after passive immunization in the rat: relation to the level of LH secretion

    International Nuclear Information System (INIS)

    Morishige, W.K.; Billiar, R.B.; Rothchild, I.

    1975-01-01

    A double antibody radioimmunologic technique was used to estimate circulating levels of free LH antibodies (Ab) (i.e., Ab available for binding to radioiodinated rat LH in vitro) after a single injection of an equine antiserum to bovine LH (LH--AS) into cyclic (diestrus-l), early pregnant (d 6 or d 8), short-term (1 d) or long-term (12 d) ovariectomized, or 8-d hyopophysectomized female rats. In both cyclic and pregnant rats given 0.5 ml LH--AS SC the blood Ab levels peaked 1 to 2 days after injection and then decreased exponentially (half-time: 14.6 to 17.0 h) and equally; vaginal estrus also appeared in the cyclic and in the aborting pregnant rats on the 6th day, and ovulation on the 7th day after LH--AS treatment, when the blood levels had fallen to very low values. The rate of exponential decrease in blood Ab levels was not affected by other routes of administration (iv or ip) of LH--AS, or by SC doses of 1.0 or 0.25 ml, although the peak levels and their duration were related to dose and route of administration. Ovariectomy significantly increased the rate of exponential Ab decrease (half-time: 9.8 h in rats tested 12 days after operation) and hypophysectomy markedly diminished it (half-time: 63.0 h in rats tested 8 days after operation). Daily treatment of hypophysectomized rats with 20 μg/day of ovine LH from the time of LH-AS injection increased the rate of exponential Ab decrease to one approaching that of the intact rats (half-time: 20.5 h). Free LH antibodies thus seem to disappear from the circulation at a rate proportional to the amount of LH in the circulation. (U.S.)

  5. Active surge control for variable speed axial compressors.

    Science.gov (United States)

    Lin, Shu; Yang, Chunjie; Wu, Ping; Song, Zhihuan

    2014-09-01

    This paper discusses active surge control in variable speed axial compressors. A compression system equipped with a variable area throttle is investigated. Based on a given compressor model, a fuzzy logic controller is designed for surge control and a proportional speed controller is used for speed control. The fuzzy controller uses measurements of the change of pressure rise as well as the change of mass flow to determine the throttle opening. The presented approach does not require the knowledge of system equilibrium or the surge line. Numerical simulations show promising results. The proposed fuzzy logic controller performs better than a backstepping controller and is capable to suppress surge at different operating points. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Assessment of storm surge disaster potential for the Andaman Islands

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, V.S.; RameshBabu, V.; Babu, M.T.; Dhinakaran, G.; Rajamanickam, G.V.

    . Supporting volume 1: math- ematical modelling of cyclone surge and related flooding. In: Cy- clone Damage in Bangladesh. United Nations Centre for Regional Development, pp. 9–37. DHI (Danish Hydraulic Institute), 2002. MIKE 21 Coastal Hydrau- lics...

  7. Storm surge model based on variational data assimilation method

    Directory of Open Access Journals (Sweden)

    Shi-li Huang

    2010-06-01

    Full Text Available By combining computation and observation information, the variational data assimilation method has the ability to eliminate errors caused by the uncertainty of parameters in practical forecasting. It was applied to a storm surge model based on unstructured grids with high spatial resolution meant for improving the forecasting accuracy of the storm surge. By controlling the wind stress drag coefficient, the variation-based model was developed and validated through data assimilation tests in an actual storm surge induced by a typhoon. In the data assimilation tests, the model accurately identified the wind stress drag coefficient and obtained results close to the true state. Then, the actual storm surge induced by Typhoon 0515 was forecast by the developed model, and the results demonstrate its efficiency in practical application.

  8. Overexpression of the LH receptor increases distant metastases in an endometrial cancer mouse model

    Directory of Open Access Journals (Sweden)

    Serena ePillozzi

    2013-11-01

    Full Text Available Objective. The aim of the present study was to define the role of luteinizing hormone receptor (LH-R expression in endometrial cancer (EC, using preclinical mouse models, to further transfer these data to the clinical setting. Methods. The role of LH-R over-expression was studied using EC cells (Hec1A, e.g. cells with low endogenous LH-R expression transfected with the LH-R (Hec1A-LH-R. In vitro cell proliferation was measured through the WST1 assay, whereas cell invasion was measured trough the matrigel assay. The effects of LH/hCG-R overexpresion in vivo were analyzed in an appropriately developed preclinical mouse model of EC, which mimicked postmenopausal conditions. The model consisted in an orthotopic xenograft of Hec1A cells into immunodeficient mice treated daily with recombinant LH, to assure high levels of LH. Results. In vitro data indicated that LH-R overexpression increased Hec1A invasiveness. In vivo results showed that tumors arising from Hec1A-LH-R cells injection displayed a higher local invasion and a higher number of distant metastases, mainly in the lung, compared to tumors obtained from the injection of Hec1A cells. LH withdrawl strongly inhibited local and distant metastatic spread of tumors, especially those arising from Hec1A-LH-R cells. Conclusions. The overexpression of the LH-R increases the ability of EC cells to undergo local invasion and metastatic spread. This occurs in the presence of high LH serum concentrations.

  9. Radioimmunoassay of bovine, ovine and porcine luteinizing hormone with a monoclonal antibody and a human tracer

    Energy Technology Data Exchange (ETDEWEB)

    Fosberg, M; Tagle, R; Madej, A; Molina, J R; Carlsson, M -A

    1993-01-01

    A radioimmunoassay for bovine (bLH), ovine (oLH) and porcine (pLH) luteinizing hormone was developed using a human [sup 125]ILH tracer from a commercial kit and a monoclonal antibody (518B7) specific for LH but with low species specificity. Standard curves demonstrated similar binding kinetics when bLH, oLH and pLH were incubated with tracer and antibody for 2 h at room temperature. A 30-min delay in the addition of the tracer gave sufficient sensitivity when analysing pLH. Separation of antibody-bound LH from free hormone was achieved by using second antibody-coated micro Sepharose beads. The assay was validated and the performance compared with that of an RIA currently in use for determination of bLH (coefficient of correlation: 0.99 and 0.98). Regardless of the standards used, intra-assay coefficients of variation were <10% for LH concentrations exceeding 1 [mu]g/L. The inter-assay coefficients of variation were <15%. The assay was used for clinical evaluation demonstrating the pre-ovulatory LH surge in two cyclic cows, LH pulsatility in an oophorectomized ewe and LH response to GnRH injection in a boar. (au) (7 refs.).

  10. Planning for partnerships: Maximizing surge capacity resources through service learning.

    Science.gov (United States)

    Adams, Lavonne M; Reams, Paula K; Canclini, Sharon B

    2015-01-01

    Infectious disease outbreaks and natural or human-caused disasters can strain the community's surge capacity through sudden demand on healthcare activities. Collaborative partnerships between communities and schools of nursing have the potential to maximize resource availability to meet community needs following a disaster. This article explores how communities can work with schools of nursing to enhance surge capacity through systems thinking, integrated planning, and cooperative efforts.

  11. Experimental Study on Noise Characteristic of Centrifugal Compressor Surge

    OpenAIRE

    Yang, Qichao; Zhao, Yuanyang; SHU, Yue; LI, Xiaosa; LI, Liansheng

    2016-01-01

    The centrifugal air compressor test rig is was designed and established. The experimental study was carried out on the surge characteristics of centrifugal compressor including the pressure in the pipe and the noise characteristics under different rotation speed. The tested results showed that both the suction pressure and discharge pressure fluctuation increase under surge condition and the amplitude of discharge pressure fluctuation is significantly higher than that of suction pressure. In ...

  12. Performance of Surge Arrester Installation to Enhance Protection

    Directory of Open Access Journals (Sweden)

    Mbunwe Muncho Josephine

    2017-01-01

    Full Text Available The effects of abnormal voltages on power system equipment and appliances in the home have raise concern as most of the equipments are very expensive. Each piece of electrical equipment in an electrical system needs to be protected from surges. To prevent damage to electrical equipment, surge protection considerations are paramount to a well designed electrical system. Lightning discharges are able to damage electric and electronic devices that usually have a low protection level and these are influenced by current or voltage pulses with a relatively low energy, which are induced by lightning currents. This calls for proper designed and configuration of surge arresters for protection on the particular appliances. A more efficient non-linear surge arrester, metal oxide varistor (MOV, should be introduced to handle these surges. This paper shows the selection of arresters laying more emphasis on the arresters for residential areas. In addition, application and installation of the arrester will be determined by the selected arrester. This paper selects the lowest rated surge arrester as it provides insulation when the system is under stress. It also selected station class and distribution class of arresters as they act as an open circuit under normal system operation and to bring the system back to its normal operation mode as the transient voltage is suppressed. Thus, reduces the risk of damage, which the protection measures can be characterized, by the reduction value of the economic loss to an acceptable level.

  13. The correlation between LH determination in the urine (luteonosticon and HI-gonavis) and serum LH, FSH, oestradiol, progesterone testosterone and prolactin levels at midcycle

    International Nuclear Information System (INIS)

    Kemeter, P.; Woegerbauer, C.; Gring, H.; Salzer, H.; Friedrich, F.; Breitenecker, G.

    1979-01-01

    Radioimmunoassays (RIA) were carried out of serum gonadotrophins, prolactin, oestradiol, progesterone and testosterone at the time of presumed ovulation in 15 normal cycles and in 4 clomiphen-stimulated cycles of 14 women. In addition, daily measurements of LH in urine were performed using two semiquantitative methods: Luteonosticon and HI-Gonavis. Finally, the viscosity of the cervical mucus was assessed daily in order to find out the optimum time for conception. LH in serum, as well as in urine, increased significantly at midcycle and so did FSH, progesterone, testosterone, prolactin and viscosity. Lutenosticon, used in the modification of Keller and Gerber 1970 showed the first significant increase 2 days before the serum LH peak. HI-Gonavis, on the other hand, showed a significant increase only on the day of LH peak in serum. The best correlation of the 3 LH methods was found between LH in serum (RIA) and HI-Gonavis in urine. For the evaluation of the optimum time for conception in normal and clomiphen-stimulated cycles, determination of the uriany LH increase at midcycle by HI-Gonavis appears to be the most economic, both in time and expense, hormone method tested. Since only one significant increase in LH becomes apparent at midcycle by this method, the interpretation of the results is easy and additional gynaecological investigations are, thus, not absolutely necessary. (author)

  14. Improved PV system reliability results from surge evaluations at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Russell H. Bonn; Sigifredo Gonzalez

    2000-01-01

    Electrical surges on ac and dc inverter power wiring and diagnostic cables have the potential to shorten the lifetime of power electronics. These surges may be caused by either nearby lightning or capacitor switching transients. This paper contains a description of ongoing surge evaluations of PV power electronics and surge mitigation hardware at Sandia

  15. Bifurcation analysis and dimension reduction of a predator-prey model for the L-H transition

    DEFF Research Database (Denmark)

    Dam, Magnus; Brøns, Morten; Juul Rasmussen, Jens

    2013-01-01

    The L-H transition denotes a shift to an improved confinement state of a toroidal plasma in a fusion reactor. A model of the L-H transition is required to simulate the time dependence of tokamak discharges that include the L-H transition. A 3-ODE predator-prey type model of the L-H transition...

  16. Surge of a Complex Glacier System - The Current Surge of the Bering-Bagley Glacier System, Alaska

    Science.gov (United States)

    Herzfeld, U. C.; McDonald, B.; Trantow, T.; Hale, G.; Stachura, M.; Weltman, A.; Sears, T.

    2013-12-01

    Understanding fast glacier flow and glacial accelerations is important for understanding changes in the cryosphere and ultimately in sea level. Surge-type glaciers are one of four types of fast-flowing glaciers --- the other three being continuously fast-flowing glaciers, fjord glaciers and ice streams --- and the one that has seen the least amount of research. The Bering-Bagley Glacier System, Alaska, the largest glacier system in North America, surged in 2011 and 2012. Velocities decreased towards the end of 2011, while the surge kinematics continued to expand. A new surge phase started in summer and fall 2012. In this paper, we report results from airborne observations collected in September 2011, June/July and September/October 2012 and in 2013. Airborne observations include simultaneously collected laser altimeter data, videographic data, GPS data and photographic data and are complemented by satellite data analysis. Methods range from classic interpretation of imagery to analysis and classification of laser altimeter data and connectionist (neural-net) geostatistical classification of concurrent airborne imagery. Results focus on the characteristics of surge progression in a large and complex glacier system (as opposed to a small glacier with relatively simple geometry). We evaluate changes in surface elevations including mass transfer and sudden drawdowns, crevasse types, accelerations and changes in the supra-glacial and englacial hydrologic system. Supraglacial water in Bering Glacier during Surge, July 2012 Airborne laser altimeter profile across major rift in central Bering Glacier, Sept 2011

  17. Spatial structure of compound dither in L/H transition

    International Nuclear Information System (INIS)

    Toda, Shinichiro; Itoh, Kimitaka; Itoh, Sanae I.; Yagi, Masatoshi; Fukuyama, Atsushi

    2000-03-01

    To study the plasma evolution and spatial structure at the L/H transition, the double hysteresis is examined by use of the 1-dimensional transport model equations. Three mechanisms for the bipolar losses, i.e., the loss cone loss, collisional bulk viscosity loss of ions and the anomalous loss are simultaneously retained. Five-fold multiple bifurcations are found to exist at the plasma edge, similar to the previous 0-dimensional study. Double hysteresis causes a self-generated oscillation, which is attributed to the compound dither, a kind of ELMs. Spatio-temporal evolution of the compound dither is analyzed. (author)

  18. LH2 three-phase pump control circuit description

    International Nuclear Information System (INIS)

    Pierce, W.

    1977-05-01

    A brief description and circuit drawings are given for a pump control system. The pump is used to circulate liquid hydrogen through the cell and heat exchanger of an LH 2 target. The pump is powered by three-phase 60 cycle power, and the control unit is powered from a positive and negative 24 V dc supply available in the NIM Bin. The control unit is packaged in a double-width NIM module. Drawings are given for the pump speed indicator, function generator, and power supply

  19. Observing Storm Surges from Space: A New Opportunity

    Science.gov (United States)

    Han, Guoqi; Ma, Zhimin; Chen, Dake; de Young, Brad; Chen, Nancy

    2013-04-01

    Coastal tide gauges can be used to monitor variations of a storm surge along the coast, but not in the cross-shelf direction. As a result, the cross-shelf structure of a storm surge has rarely been observed. In this study we focus on Hurricane Igor-induced storm surge off Newfoundland, Canada. Altimetric observations at about 2:30, September 22, 2010 UTC (hours after the passage of Hurricane Igor) reveal prominent cross-shelf variation of sea surface height during the storm passage, including a large nearshore slope and a mid-shelf depression. A significant coastal surge of 1 m derived from satellite altimetry is found to be consistent with tide-gauge measurements at nearby St. John's station. The post-storm sea level variations at St. John's and Argentia are argued to be associated with free equatorward-propagating continental shelf waves (with phase speeds of 11-13 m/s), generated along the northeast Newfoundland coast hours after the storm moved away from St. John's. The cross-shelf e-folding scale of the shelf wave was estimated to be ~100 km. We further show approximate agreement of altimetric and tide-gauge observations in the Gulf of Mexico during Hurricane Katrina (2005) and Isaac (2012). The study for the first time in the literature shows the robustness of satellite altimetry to observe storm surges, complementing tide-gauge observations for the analysis of storm surge characteristics and for the validation and improvement of storm surge models.

  20. The involvement of dopaminergic system on LH secretion Nelore heifers Sistema dopaminérgico na secreção de LH de novilhas Nelore

    Directory of Open Access Journals (Sweden)

    Silvia Helena Venturoli Perri

    2009-12-01

    Full Text Available The aim of this study was to evaluate the response of sulpiride administration (dopamine D2 antagonist, 0.59 m/kg body weight, s.c. and blood collected every 15 min for 10 h thereafter on Luteinizing Hormone (LH secretion in B. indicus pre-pubertal heifers at 8, 12 and 16 month of age. LH was quantified by RIA, sensitivity (0.039 ng/ml and CV (15.51%. In heifers given sulpiride treatment didn’t differ (P≥0.05 in LH concentration, total secretion area, peak total area, number of peaks, area of highest secretion peak and time to highest peak occurrence and maximum LH secretion, from control group. The results suggest absence of dopamine D2 antagonist effect on LH secretion in pre-pubertal Nellore heifers, didn’t neurotransmitter participating on sexual maturation.O presente trabalho foi realizado com o objetivo de investigar a variação na secreção do Hormônio Luteinizante (LH em resposta ao tratamento com sulpiride, antagonista de receptor (D2 dopaminérgico, com administração de 0,59mg/kg, s.c. e colheita de amostras de sangue a cada 15min, por 10h. Foram utilizadas 10 novilhas da raça Nelore pré-púberes, aos 8, 12 e 16 meses de idade. A concentração de LH foi quantificada por radioimunoensaio, e o coeficiente de variação intra, o interensaio e a sensibilidade dos ensaios de LH foram respectivamente de: 11,86%; 15,51%; 0,039ng/mL. O tratamento com sulpiride não diferiu na concentração média de LH, área total de secreção de LH e picos, número de picos, área do maior pico, tempo necessário ao aparecimento do maior pico de secreção de LH e amplitude máxima de LH, em comparação ao grupo controle. Os resultados indicam ausência de efeito da dopamina, através de receptores D2, durante a fase pré-púbere, em novilhas da raça Nelore, o que sinaliza a não participação como neurotransmissora na secreção de LH durante o processo de maturação sexual.

  1. Reusable LH2 tank technology demonstration through ground test

    Science.gov (United States)

    Bianca, C.; Greenberg, H. S.; Johnson, S. E.

    1995-01-01

    The paper presents the project plan to demonstrate, by March 1997, the reusability of an integrated composite LH2 tank structure, cryogenic insulation, and thermal protection system (TPS). The plan includes establishment of design requirements and a comprehensive trade study to select the most suitable Reusable Hydrogen Composite Tank system (RHCTS) within the most suitable of 4 candidate structural configurations. The 4 vehicles are winged body with the capability to deliver 25,000 lbs of payload to a circular 220 nm, 51.6 degree inclined orbit (also 40,000 lbs to a 28.5 inclined 150 nm orbit). A prototype design of the selected RHCTS is established to identify the construction, fabrication, and stress simulation and test requirements necessary in an 8 foot diameter tank structure/insulation/TPS test article. A comprehensive development test program supports the 8 foot test article development and involves the composite tank itself, cryogenic insulation, and integrated tank/insulation/TPS designs. The 8 foot diameter tank will contain the integrated cryogenic insulation and TPS designs resulting from this development and that of the concurrent lightweight durable TPS program. Tank ground testing will include 330 cycles of LH2 filling, pressurization, body loading, depressurization, draining, and entry heating.

  2. Characterization of LH induced current carrying fast electrons in JET

    Energy Technology Data Exchange (ETDEWEB)

    Ramponi, G.; Airoldi, A. [Consiglio Nazionale delle Ricerche, Milan (Italy). Lab. di Fisica del Plasma; Bartlett, D.; Brusati, M.; Froissard, P.; Gormezano, C.; Rimini, F.; Silva, R.P. da; Tanzi, C.P. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

    1992-12-31

    Lower Hybrid Current Drive (LHCD) experiments have recently been made at JET by coupling up to 2.4 MW of RF power at 3.7 GHz, with a power spectrum centered at n{sub ||} = 1.8 {+-} 0.2 corresponding to a resonating electron energy of about 100 keV via Electron Landau Damping. The Current Drive (CD) efficiency has been observed to increase when LH and ICRH power are applied simultaneously to the plasma, suggesting that a part of the fast magnetosonic wave is absorbed on the LH-generated fast electrons. An important problem of CD experiments in tokamaks is the determination of the radial distribution of the driven current and the characterization in the momentum space of the current carrying fast electrons by using appropriate diagnostic tools. For this purpose, a combined analysis of the Electron Cyclotron Emission (ECE) and of the Fast Electron Bremsstrahlung (FEB) measurements has been made, allowing the relevant parameters of the suprathermal electrons to be estimated. (author) 5 refs., 5 figs., 2 tabs.

  3. Characterization of LH induced current carrying fast electrons in JET

    International Nuclear Information System (INIS)

    Ramponi, G.; Airoldi, A.; Bartlett, D.; Brusati, M.; Froissard, P.; Gormezano, C.; Rimini, F.; Silva, R.P. da; Tanzi, C.P.

    1992-01-01

    Lower Hybrid Current Drive (LHCD) experiments have recently been made at JET by coupling up to 2.4 MW of RF power at 3.7 GHz, with a power spectrum centered at n || = 1.8 ± 0.2 corresponding to a resonating electron energy of about 100 keV via Electron Landau Damping. The Current Drive (CD) efficiency has been observed to increase when LH and ICRH power are applied simultaneously to the plasma, suggesting that a part of the fast magnetosonic wave is absorbed on the LH-generated fast electrons. An important problem of CD experiments in tokamaks is the determination of the radial distribution of the driven current and the characterization in the momentum space of the current carrying fast electrons by using appropriate diagnostic tools. For this purpose, a combined analysis of the Electron Cyclotron Emission (ECE) and of the Fast Electron Bremsstrahlung (FEB) measurements has been made, allowing the relevant parameters of the suprathermal electrons to be estimated. (author) 5 refs., 5 figs., 2 tabs

  4. Proposed Strategies for DWPF Melter Off-Gas Surge Control

    International Nuclear Information System (INIS)

    CHOI, ALEXANDERS.

    2004-01-01

    Off-gas surging is inherent to the operation of slurry-fed melters. Although the melter design and the feed chemistry are both known to significantly affect off-gas surging, the frequency and intensity of surges are in essence unpredictable. In typical off-gas surges, both condensable and non condensable flows spike simultaneously. Condensable or steam surges have been observed to occur as the boiling water layer occasionally falls into the crevices of the cold cap or flows over the edges of the cold cap, thereby coming in contact with the melt surface. The resulting steam surges can pressurize the melter considerably and, therefore, are responsible for the bulk of pressure transients that propagate throughout the off-gas system. The non condensable surges occur as the calcine gases that have been accumulating within the cold cap finally build up enough pressure to be released through the temporary openings of the cold cap. The analysis of off-gas data has shown that over 90 of the gas released during a surge is due to steam.1 Therefore, it is essential to have a large inventory of water in the cold cap for any significant pressure spikes to occur. With the Melter 2 vapor space temperature typically running at 720C, the water layer in the cold cap will quickly evaporate once the feeding stops, and the potential for any large pressure spikes should practically cease to exist. The analysis also showed that large pressure spikes well above 2 inches H2O cannot occur under the steam surge scenarios described above. More severe conditions should prevail and one such condition would be that the feed materials form a mound with a growing lake on top, while the melt below remains very fluidic due to its low viscosity, thus resulting in greater movements both in the lateral as well as vertical directions. Once the mound begins to grow, its rate should accelerate, since the heat transfer rate to the upper regions of the cold cap is inversely proportional to the cold cap

  5. Ground-State Electronic Structure of RC-LH1 and LH2 Pigment Assemblies of Purple Bacteria via the EBF-MO Method.

    Science.gov (United States)

    Shrestha, Kushal; Jakubikova, Elena

    2015-08-20

    Light-harvesting antennas are protein-pigment complexes that play a crucial role in natural photosynthesis. The antenna complexes absorb light and transfer energy to photosynthetic reaction centers where charge separation occurs. This work focuses on computational studies of the electronic structure of the pigment networks of light-harvesting complex I (LH1), LH1 with the reaction center (RC-LH1), and light-harvesting complex II (LH2) found in purple bacteria. As the pigment networks of LH1, RC-LH1, and LH2 contain thousands of atoms, conventional density functional theory (DFT) and ab initio calculations of these systems are not computationally feasible. Therefore, we utilize DFT in conjunction with the energy-based fragmentation with molecular orbitals method and a semiempirical approach employing the extended Hückel model Hamiltonian to determine the electronic properties of these pigment assemblies. Our calculations provide a deeper understanding of the electronic structure of natural light-harvesting complexes, especially their pigment networks, which could assist in rational design of artificial photosynthetic devices.

  6. Tropical cyclone induced asymmetry of sea level surge and fall and its presentation in a storm surge model with parametric wind fields

    Science.gov (United States)

    Peng, Machuan; Xie, Lian; Pietrafesa, Leonard J.

    The asymmetry of tropical cyclone induced maximum coastal sea level rise (positive surge) and fall (negative surge) is studied using a three-dimensional storm surge model. It is found that the negative surge induced by offshore winds is more sensitive to wind speed and direction changes than the positive surge by onshore winds. As a result, negative surge is inherently more difficult to forecast than positive surge since there is uncertainty in tropical storm wind forecasts. The asymmetry of negative and positive surge under parametric wind forcing is more apparent in shallow water regions. For tropical cyclones with fixed central pressure, the surge asymmetry increases with decreasing storm translation speed. For those with the same translation speed, a weaker tropical cyclone is expected to gain a higher AI (asymmetry index) value though its induced maximum surge and fall are smaller. With fixed RMW (radius of maximum wind), the relationship between central pressure and AI is heterogeneous and depends on the value of RMW. Tropical cyclone's wind inflow angle can also affect surge asymmetry. A set of idealized cases as well as two historic tropical cyclones are used to illustrate the surge asymmetry.

  7. Methodology for surge pressure evaluation in a water injection system

    Energy Technology Data Exchange (ETDEWEB)

    Meliande, Patricia; Nascimento, Elson A. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Civil; Mascarenhas, Flavio C.B. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Lab. de Hidraulica Computacional; Dandoulakis, Joao P. [SHELL of Brazil, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    Predicting transient effects, known as surge pressures, is of high importance for offshore industry. It involves detailed computer modeling that attempts to simulate the complex interaction between flow line and fluid in order to ensure efficient system integrity. Platform process operators normally raise concerns whether the water injection system is adequately designed or not to be protected against possible surge pressures during sudden valve closure. This report aims to evaluate the surge pressures in Bijupira and Salema water injection systems due to valve closure, through a computer model simulation. Comparisons among the results from empirical formulations are discussed and supplementary analysis for Salema system were performed in order to define the maximum volumetric flow rate for which the design pressure was able to withstand. Maximum surge pressure values of 287.76 bar and 318.58 bar, obtained in Salema and Bijupira respectively, using empirical formulations have surpassed the operating pressure design, while the computer model results have pointed the greatest surge pressure value of 282 bar in Salema system. (author)

  8. Developing models for patient flow and daily surge capacity research.

    Science.gov (United States)

    Asplin, Brent R; Flottemesch, Thomas J; Gordon, Bradley D

    2006-11-01

    Between 1993 and 2003, visits to U.S. emergency departments (EDs) increased by 26%, to a total of 114 million visits annually. At the same time, the number of U.S. EDs decreased by more than 400, and almost 200,000 inpatient hospital beds were taken out of service. In this context, the adequacy of daily surge capacity within the system is clearly an important issue. However, the research agenda on surge capacity thus far has focused primarily on large-scale disasters, such as pandemic influenza or a serious bioterrorism event. The concept of daily surge capacity and its relationship to the broader research agenda on patient flow is a relatively new area of investigation. In this article, the authors begin by describing the overlap between the research agendas on daily surge capacity and patient flow. Next, they propose two models that have potential applications for both daily surge capacity and hospitalwide patient-flow research. Finally, they identify potential research questions that are based on applications of the proposed research models.

  9. Surge recovery techniques for the Tevatron cold compressors

    International Nuclear Information System (INIS)

    Martinez, A.; Klebaner, A.L.; Makara, J.N.; Theilacker, J.C.; Fermilab

    2006-01-01

    The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, made by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations [1]. The compressor is designed to pump 60 g/s of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/s and operating speeds between 40 and 95 krpm. Since initial commissioning in 1993, Tevatron transient conditions such as quench recovery have led to multiple-location machine trips as a result of the cold compressors entering the surge regime. Historically, compressors operating at lower inlet pressures and higher speeds have been especially susceptible to these machine trips and it was not uncommon to have multiple compressor trips during large multiple-house quenches. In order to cope with these events and limit accelerator down time, surge recovery techniques have been implemented in an attempt to prevent the compressors from tripping once the machine entered this surge regime. This paper discusses the different methods of surge recovery that have been employed. Data from tests performed at the Cryogenic Test Facility at Fermilab as well as actual Tevatron operational data were utilized. In order to aid in the determination of the surge region, a full mapping study was undertaken to characterize the entire pressure field of the cold compressor. These techniques were then implemented and tested at several locations in the Tevatron with some success

  10. Three-step in vitro maturation culture of bovine oocytes imitating temporal changes of estradiol-17β and progesterone concentrations in preovulatory follicular fluid

    Directory of Open Access Journals (Sweden)

    M. Matsuo

    2017-10-01

    Full Text Available The objective of the article is to evaluate the effect of three-step in vitro maturation (IVM culture system imitating estradiol-17β (E2 and progesterone (P4 concentrations in preovulatory follicles on in vitro bovine embryo production. The cumulus–oocyte complexes (COCs were collected from follicles (2 to 8 mm in diameter of bovine ovaries obtained from a local slaughterhouse. For IVM, the COCs were cultured for 22 h in a three-step system: (1 culture in medium 199, containing 700 ng mL−1 E2 and 50 ng mL−1 P4, for 5 h, followed by the medium containing 150 ng mL−1 E2 and 150 ng mL−1 P4 for 11 h, and then the medium containing 20 ng mL−1 E2 and 300 ng mL−1 P4 for 6 h (EP group; (2 culture in the medium containing 700 ng mL−1 E2 for 5 h, followed by the medium containing 150 ng mL−1 E2 for 11 h, and then the medium containing 20 ng mL−1 E2 for 6 h (E group; or (3 culture in the medium containing 50 ng mL−1 P4 for 5 h, followed by the medium containing 150 ng mL−1 P4 for 11 h, and then the medium containing 300 ng mL−1 P4 for 6 h (P group. The COCs were cultured in the medium containing 1000 ng mL−1 E2 for 22 h (control group. After IVM, the COCs were co-incubated with sperm and further cultured. At 48 h after insemination, the cleavage rate of embryos was not different among the groups. At 192 h after insemination, the blastocyst formation rate of EP group was significantly higher than that of the other groups. The total cell number of blastocysts did not differ among the groups. In conclusion, these results demonstrate that the three-step IVM culture system of bovine oocytes imitating temporal changes of E2 and P4 concentrations in preovulatory follicular fluid improves the developmental potential of embryos in vitro.

  11. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH), ch. 10

    International Nuclear Information System (INIS)

    Franchimont, P.

    1976-01-01

    A radioimmunoassay for FSH and LH is described. Both FSH and LH were labelled with 131 I by the Greenwood method. The FSH iodination mixture is purified by passing over a column of DEAE cellulose. The LH iodination mixture can be purified by sephadex gel filtration or by cellulose adsorption chromatography. After incubation, the bound and free-labelled hormones are separated by the double antibody technique

  12. Influence of hormonal control on LH pulsatility and secretion in women with classical congenital adrenal hyperplasia.

    Science.gov (United States)

    Bachelot, Anne; Chakhtoura, Zeina; Plu-Bureau, Geneviève; Coudert, Mathieu; Coussieu, Christiane; Badachi, Yasmina; Dulon, Jérome; Charbit, Beny; Touraine, Philippe

    2012-10-01

    Women with classical congenital adrenal hyperplasia (CAH) exhibit reduced fertility due to several factors including anovulation. This has been attributed to a disturbed gonadotropic axis as in polycystic ovary syndrome (PCOS), but there is no precise evaluation. Our aim was to evaluate the gonadotropic axis and LH pulsatility patterns and to determine factor(s) that could account for the potential abnormality of LH pulsatility. Case/control study. Sixteen CAH women (11 with the salt-wasting form and five with the simple virilizing form), aged from 18 to 40 years, and 16 age-matched women, with regular menstrual cycles (28 ± 3 days), were included. LH pulse patterns over 6 h were determined in patients and controls. No differences were observed between patients and controls in terms of mean LH levels, LH pulse amplitude, or LH frequency. In CAH patients, LH pulsatility patterns were heterogeneous, leading us to perform a clustering analysis of LH data, resulting in a two-cluster partition. Patients in cluster 1 had similar LH pulsatility patterns to the controls. Patients in cluster 2 had: lower LH pulse amplitude and frequency and presented menstrual cycle disturbances more frequently; higher 17-OH progesterone, testosterone, progesterone, and androstenedione levels; and lower FSH levels. LH pulsatility may be normal in CAH women well controlled by hormonal treatment. Undertreatment is responsible for hypogonadotropic hypogonadism, with low LH pulse levels and frequency, but not PCOS. Suppression of progesterone and androgen concentrations during the follicular phase of the menstrual cycle should be a major objective in these patients.

  13. Monomeric RC-LH1 core complexes retard LH2 assembly and intracytoplasmic membrane formation in PufX-minus mutants of Rhodobacter sphaeroides.

    Science.gov (United States)

    Adams, Peter G; Mothersole, David J; Ng, Irene W; Olsen, John D; Hunter, C Neil

    2011-09-01

    In the model photosynthetic bacterium Rhodobacter sphaeroides domains of light-harvesting 2 (LH2) complexes surround and interconnect dimeric reaction centre-light-harvesting 1-PufX (RC-LH1-PufX) 'core' complexes, forming extensive networks for energy transfer and trapping. These complexes are housed in spherical intracytoplasmic membranes (ICMs), which are assembled in a stepwise process where biosynthesis of core complexes tends to dominate the early stages of membrane invagination. The kinetics of LH2 assembly were measured in PufX mutants that assemble monomeric core complexes, as a consequence of either a twelve-residue N-terminal truncation of PufX (PufXΔ12) or the complete removal of PufX (PufX(-)). Lower rates of LH2 assembly and retarded maturation of membrane invagination were observed for the larger and less curved ICM from the PufX(-) mutant, consistent with the proposition that local membrane curvature, initiated by arrays of bent RC-LH1-PufX dimers, creates a favourable environment for stable assembly of LH2 complexes. Transmission electron microscopy and high-resolution atomic force microscopy were used to examine ICM morphology and membrane protein organisation in these mutants. Some partitioning of core and LH2 complexes was observed in PufX(-) membranes, resulting in locally ordered clusters of monomeric RC-LH1 complexes. The distribution of core and LH2 complexes in the three types of membrane examined is consistent with previous models of membrane curvature and domain formation (Frese et al., 2008), which demonstrated that a combination of crowding and asymmetries in sizes and shapes of membrane protein complexes drives membrane organisation. 2011 Elsevier B.V. All rights reserved.

  14. Proinflammatory Cytokine Infusion Attenuates LH's Feedforward on Testosterone Secretion: Modulation by Age

    Science.gov (United States)

    Yang, Rebecca; Roelfsema, Ferdinand; Takahashi, Paul

    2016-01-01

    Context: In the experimental animal, inflammatory signals quench LH's feedforward drive of testosterone (T) secretion and appear to impair GnRH-LH output. The degree to which such suppressive effects operate in the human is not known. Objective: To test the hypothesis that IL-2 impairs LH's feedforward drive on T and T's feedback inhibition of LH secretion in healthy men. Setting: Mayo Center for Translational Science Activities. Patients or Other Participants: A total of 35 healthy men, 17 young and 18 older. Interventions: Randomized prospective double-blind saline-controlled study of IL-2 infusion in 2 doses with concurrent 10-minute blood sampling for 24 hours. Main Outcome Measures: Deconvolution analysis of LH and T secretion. Results: After saline injection, older compared with young men exhibited reduced LH feedforward drive on T secretion (P feedback inhibition of LH secretion (P feedforward onto T secretion declined markedly especially in young subjects (P feedback on LH secretion especially in older volunteers. Conclusion: This investigation confirms combined feedforward and feedback deficits in older relative to young men given saline and demonstrates 1) joint mechanisms by which IL-2 enforces biochemical hypogonadism, viz, combined feedforward block and feedback amplification; and 2) unequal absolute inhibition of T and LH secretion by IL-2 in young and older men. These outcomes establish that the male gonadal axis is susceptible to dual-site suppression by a prototypic inflammatory mediator. Thus, we postulate that selected ILs might also enforce male hypogonadism in chronic systemic inflammation. PMID:26600270

  15. Structural Stability of Light-harvesting Protein LH2 Adsorbed on Mesoporous Silica Supports.

    Science.gov (United States)

    Shibuya, Yuuta; Itoh, Tetsuji; Matsuura, Shun-ichi; Yamaguchi, Akira

    2015-01-01

    In the present study, we examined the reversible thermal deformation of the membrane protein light-harvesting complex LH2 adsorbed on mesoporous silica (MPS) supports. The LH2 complex from Thermochromatium tepidum cells was conjugated to MPS supports with a series of pore diameter (2.4 to 10.6 nm), and absorption spectra of the resulting LH2/MPS conjugates were observed over a temperature range of 273 - 313 K in order to examine the structure of the LH2 adsorbed on the MPS support. The experimental results confirmed that a slight ellipsoidal deformation of LH2 was induced by adsorption on the MPS supports. On the other hand, the structural stability of LH2 was not perturbed by the adsorption. Since the pore diameter of MPS support did not influence the structural stability of LH2, it could be considered that the spatial confinement of LH2 in size-matches pore did not improve the structural stability of LH2.

  16. Operation and coupling of LH waves with the ITER-like wall at JET

    International Nuclear Information System (INIS)

    Kirov, K K; Mailloux, J; Arnoux, G; Baranov, Yu; Brix, M; Mayoral, M-L; Rimini, F; Stamp, M; Ekedahl, A; Goniche, M; Petrzilka, V; Jachmich, S; Ongena, J

    2013-01-01

    In this paper important aspects of the lower hybrid (LH) operation with the ITER-like wall (ILW) [1] at JET are reported. Impurity release during LH operation was investigated and it was found that there is no significant Be increase with LH power. The concentration of W was analysed in more detail and it was concluded that LH negligibly contributes to its increase. No cases of W accumulation in LH-only heating experiments were observed so far. LH wave coupling was studied and optimised to achieve the level of system performance similar to before ILW installation. Measurements by Li-beam were used to study systematic dependencies of the scrape-off layer (SOL) density on the gas injection rate from a dedicated gas introduction module and the LH power and launcher position. Experimental results are supported by SOL transport modelling. Observations of arcs in front of the LH launcher and hotspots on magnetically connected sections of the vessel are reported. Overall, a relatively trouble-free operation of the LH system up to 2.5 MW of coupled radio frequency power in L-mode plasma was achieved with no indication that the power cannot be increased further. (paper)

  17. A numerical storm surge forecast model with Kalman filter

    Institute of Scientific and Technical Information of China (English)

    Yu Fujiang; Zhang Zhanhai; Lin Yihua

    2001-01-01

    Kalman filter data assimilation technique is incorporated into a standard two-dimensional linear storm surge model. Imperfect model equation and imperfect meteorological forcimg are accounted for by adding noise terms to the momentum equations. The deterministic model output is corrected by using the available tidal gauge station data. The stationary Kalman filter algorithm for the model domain is calculated by an iterative procedure using specified information on the inaccuracies in the momentum equations and specified error information for the observations. An application to a real storm surge that occurred in the summer of 1956 in the East China Sea is performed by means of this data assimilation technique. The result shows that Kalman filter is useful for storm surge forecast and hindcast.

  18. Electromagnetic computation methods for lightning surge protection studies

    CERN Document Server

    Baba, Yoshihiro

    2016-01-01

    This book is the first to consolidate current research and to examine the theories of electromagnetic computation methods in relation to lightning surge protection. The authors introduce and compare existing electromagnetic computation methods such as the method of moments (MOM), the partial element equivalent circuit (PEEC), the finite element method (FEM), the transmission-line modeling (TLM) method, and the finite-difference time-domain (FDTD) method. The application of FDTD method to lightning protection studies is a topic that has matured through many practical applications in the past decade, and the authors explain the derivation of Maxwell's equations required by the FDTD, and modeling of various electrical components needed in computing lightning electromagnetic fields and surges with the FDTD method. The book describes the application of FDTD method to current and emerging problems of lightning surge protection of continuously more complex installations, particularly in critical infrastructures of e...

  19. Community health facility preparedness for a cholera surge in Haiti.

    Science.gov (United States)

    Mobula, Linda Meta; Jacquet, Gabrielle A; Weinhauer, Kristin; Alcidas, Gladys; Thomas, Hans-Muller; Burnham, Gilbert

    2013-01-01

    With increasing population displacement and worsening water insecurity after the 2010 earthquake, Haiti experienced a large cholera outbreak. Our goal was to evaluate the strengths and weaknesses of seven community health facilities' ability to respond to a surge in cholera cases. Since 2010, Catholic Relief Services (CRS) with a number of public and private donors has been working with seven health facilities in an effort to reduce morbidity and mortality from cholera infection. In November 2012, CRS through the Centers for Disease Control and Prevention (CDC)'s support, asked the Johns Hopkins Center for Refugee and Disaster Response to conduct a cholera surge simulation tabletop exercise at these health facilities to improve each facility's response in the event of a cholera surge. Using simulation development guidelines from the Pan American Health Organization and others, a simulation scenario script was produced that included situations of differing severity, supply chain, as well as a surge of patients. A total of 119 hospital staff from seven sites participated in the simulation exercise including community health workers, clinicians, managers, pharmacists, cleaners, and security guards. Clinics that had challenges during the simulated clinical care of patients were those that did not appropriately treat all cholera patients according to protocol, particularly those that were vulnerable, those that would need additional staff to properly treat patients during a surge of cholera, and those that required a better inventory of supplies. Simulation-based activities have the potential to identify healthcare delivery system vulnerabilities that are amenable to intervention prior to a cholera surge.

  20. Effect of switching surges on ehv system design

    Energy Technology Data Exchange (ETDEWEB)

    Baril, G A; McGillis, D

    1966-01-01

    The presence of switching surges imposes certain conditions on the design of ehv system and certain resulting requirements in the basic components of these systems. At extra high voltage, it becomes both a practical as well as an economic necessity to limit the magnitude of switching surge overvoltages. This can be accomplished by the installation of suitable terminal equipment, and for the 735 kV system it was found necessary to install permanently connected shunt reactors on the transmission lines and to provide for the installation of closing resistors on the circuit breakers.

  1. Investigation of surge protective devices operation of a wind generator

    International Nuclear Information System (INIS)

    Dimitrov, D.; Vasileva, M.

    2008-01-01

    The interest to the investments in a wind energetics increases in the last years. The wind energetics is the fastest developing direction in the energetics in global scale. The wind energy is more attractive because its prices are lower in comparison of the other technologies for generating energy. The right choice of the surge protective devices has the important meaning on building and exploitation of the wind generators. The aim of this paper is investigation of the surge protective devices operation when they are installation to a wind generator. (authors)

  2. Statistical theory of L-H transition in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, S.-I. [Kyushu Univ., Research Institute for Applied Mechanics, Kasuga, Fukuoka (Japan); Itoh, K.; Toda, S. [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2003-01-01

    A statistical model for the bifurcation of the radial electric field E{sub r} is developed in view of describing L-H transitions of tokamak plasmas. Noise in micro fluctuations is shown to lead to random changes of E{sub r}, if a deterministic approach allows for more than one solution. The probability density function for and the ensemble average of E{sub r} are obtained. The L-to-H and the H-to-L transition probabilities are calculated, and the effective phase limit is derived. Due to the suppression of turbulence by shear in E{sub r}, the limit deviates from Maxwell's rule. The ensemble average of heat flux as well as that of E{sub r} do not show a hysteresis in contrast to the deterministic model. Experimental condition for observing the hysteresis is also addressed. (author)

  3. The MuCool/MICE LH2 Absorber Program

    International Nuclear Information System (INIS)

    Cummings, Mary Anne

    2004-01-01

    Hydrogen absorber R and D for the MuCool Collaboration is actively pushing ahead on two parallel and complementary fronts. The continuing LH2 engineering and technical developments by the MuCool group, conducted by ICAR institutions (NIU, IIT and UIUC), the University of Mississippi and Oxford University in cooperation with Fermilab, are summarized here, including plans for the first tests of an absorber prototype from Osaka University and KEK cooled by internal convection at the newly constructed FNAL MuCool Test Area (MTA). Designs for the high-power test of another absorber prototype (employing external heat exchange) are complete and the system will be installed by summer 2004. A convection-cooled absorber design is being developed for the approved MICE cooling demonstration at Rutherford Appleton Laboratory

  4. Study of EAST LH antennas coupling at ENEA-Frascati

    Energy Technology Data Exchange (ETDEWEB)

    Panaccione, L.; Mirizzi, F. [Consorzio CREATE, Via Claudio 21, 80125, Napoli (Italy); Ceccuzzi, S.; Cesario, R.; Tuccillo, A. A., E-mail: angelo.tuccillo@enea.it [ENEA for EUROfusion, via E. Fermi 45, 00044 Frascati (RM) (Italy); Ding, B. J.; Li, M.; Liu, F.; Liu, L.; Shan, J. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2015-12-10

    The two Lower Hybrid (LH) launchers of the EAST tokamak have been analysed using some tools available at ENEA-Frascati research centre. The antennas, working at 2.45 and 4.6 GHz, have been assessed in terms of reflection coefficient and launched power spectrum for several plasma loads differing in the electron density profile. Fitting an experimental profile we derived a set of parameterised realistic density profiles to compute the coupling performances of different spectra, launched by considering different phasing between antenna modules. The sensitivity to the tilt of the magnetic field with respect to the equatorial plane as well as to an additional progressive phasing at the mouth due to the toroidal curvature has been studied too. The most suitable operational conditions for the minimization of reflected power and side lobes in the n{sub ||} spectra are identified.

  5. 5l/h pump for dosing corrosion radioactive liquids

    International Nuclear Information System (INIS)

    Przybylovich, S.; Shraer, V.; Chermak, R.

    1977-01-01

    The technical requirements, design and main technical characteristics of the pump for dosing corrosion and radioactive liquids with capacity up to 5 l/h are described. The design is based on the popular sixvertical split casing pump. The pump has four separate pump membrane type blocks with nonstraight hydraulic membrane control. The membranes are made of the cold worked CrNi(18/10)type stainless steel with thickness up to 0.1 mm and have the lifetime up to 3000 hours. The remote pump heads are used for pumping radioactive fluids when the pumping goes behind the safe wall, separating the pump from a hot lab. The tests showed that the pump secures the satisfactory accuracy of dozing and uniformity of pumping and that it is really possible to achieve the required life time of 10000 hours by this pump

  6. Statistical theory of L-H transition in tokamaks

    International Nuclear Information System (INIS)

    Itoh, S.-I.; Itoh, K.; Toda, S.

    2003-01-01

    A statistical model for the bifurcation of the radial electric field E r is developed in view of describing L-H transitions of tokamak plasmas. Noise in micro fluctuations is shown to lead to random changes of E r , if a deterministic approach allows for more than one solution. The probability density function for and the ensemble average of E r are obtained. The L-to-H and the H-to-L transition probabilities are calculated, and the effective phase limit is derived. Due to the suppression of turbulence by shear in E r , the limit deviates from Maxwell's rule. The ensemble average of heat flux as well as that of E r do not show a hysteresis in contrast to the deterministic model. Experimental condition for observing the hysteresis is also addressed. (author)

  7. Surge Protection in Low-Voltage AC Power Circuits: An Anthology

    Science.gov (United States)

    Martzloff, F. D.

    2002-10-01

    The papers included in this part of the Anthology provide basic information on the propagation of surges in low-voltage AC power circuits. The subject was approached by a combination of experiments and theoretical considerations. One important distinction is made between voltage surges and current surges. Historically, voltage surges were the initial concern. After the introduction and widespread use of current-diverting surge-protective devices at the point-of-use, the propagation of current surges became a significant factor. The papers included in this part reflect this dual dichotomy of voltage versus current and impedance mismatch effects versus simple circuit theory.

  8. Genetic analysis and fine mapping of LH1 and LH2, a set of complementary genes controlling late heading in rice (Oryza sativa L.).

    Science.gov (United States)

    Liu, Shuang; Wang, Feng; Gao, Li Jun; Li, Jin Hua; Li, Rong Bai; Gao, Han Liang; Deng, Guo Fu; Yang, Jin Shui; Luo, Xiao Jin

    2012-12-01

    Heading date in rice (Oryza sativa L.) is a critical agronomic trait with a complex inheritance. To investigate the genetic basis and mechanism of gene interaction in heading date, we conducted genetic analysis on segregation populations derived from crosses among the indica cultivars Bo B, Yuefeng B and Baoxuan 2. A set of dominant complementary genes controlling late heading, designated LH1 and LH2, were detected by molecular marker mapping. Genetic analysis revealed that Baoxuan 2 contains both dominant genes, while Bo B and Yuefeng B each possess either LH1 or LH2. Using larger populations with segregant ratios of 3 : 1, we fine-mapped LH1 to a 63-kb region near the centromere of chromosome 7 flanked by markers RM5436 and RM8034, and LH2 to a 177-kb region on the short arm of chromosome 8 between flanking markers Indel22468-3 and RM25. Some candidate genes were identified through sequencing of Bo B and Yuefeng B in these target regions. Our work provides a solid foundation for further study on gene interaction in heading date and has application in marker-assisted breeding of photosensitive hybrid rice in China.

  9. Diagnostic evaluation of serum FSH and LH in primary amenorrhea by radioimmunoassay

    International Nuclear Information System (INIS)

    Hong, I.S.; Kim, G.E.; Yoo, H.S.; Lee, J.T.; Park, C.Y.

    1980-01-01

    The usefulness of single, random measurements of serum FSH and LH in the diagnosis of primary amenorrhea by radioimmunoassay was investigated. The 16 patients were divided into 3 groups by the level of serum FSH and LH. The first group with increased level of serum FSH and LH is five patients, all of these are related to the acquired or congenital abnormality of the ovary. Further studies indicated include buccal smear, chromosome analysis, gynecography and laparoscopy. The second group with normal serum FSH and LH is nine patients, four patients of these are related to the developmental anomaly of the Mullerian duct and five patients are undetermined origin. Further studies indicated include laparoscopy and gynecography. The third group with decreased serum FSH and normal or decreased serum LH is two patients, one of these is related to the pituitary function, isolated FSH deficiency, the other is undetermined origin. Further studies indicated include the pituitary function test, LH-RH stimulation test, skull radiography. Determination of serum FSH and LH levels does not permit a specific etiologic diagnosis of promary amenorrhea. However the serum levels of FSH and LH can be used to differentiate the principal area of the investigation and can be of assistance in choosing more specific testing procedures. (Author)

  10. Fluorescence spectral fluctuations of single LH2 complexes from Rhodopseudomonas acidophila strain 10050

    NARCIS (Netherlands)

    Rutkauskas, D.; Novoderezkhin, V.; Cogdell, R.J.; van Grondelle, R.

    2004-01-01

    We have investigated the energy landscape of the bacterial photosynthetic peripheral light-harvesting complex LH2 of purple bacterium Rhodopseudomonas acidophila by monitoring sequences of fluorescence spectra of single LH2 assemblies, at room temperature, with different excitation intensities as

  11. LH-RH binding to purified pituitary plasma membranes: absence of adenylate cyclase activation.

    Science.gov (United States)

    Clayton, R N; Shakespear, R A; Marshall, J C

    1978-06-01

    Purified bovine pituitary plasma membranes possess two specific LH-RH binding sites. The high affinity site (2.5 X 10(9) l/mol) has low capacity (9 X 10(-15) mol/mg membrane protein) while the low affinity site 6.1 X 10(5) l/mol) has a much higher capacity (1.1 X 10(-10) mol/mg). Specific LH-RH binding to plasma membranes is increased 8.5-fold during purification from homogenate whilst adenylate cyclase activity is enriched 7--8-fold. Distribution of specific LH-RH binding to sucrose density gradient interface fractions parallels that of adenylate cyclase activity. Mg2+ and Ca2+ inhibit specific [125I]LH-RH binding at micromolar concentrations. Synthetic LH-RH, up to 250 microgram/ml, failed to stimulate adenylase cyclase activity of the purified bovine membranes. Using a crude 10,800 g rat pituitary membrane preparation, LH-RH similarly failed to activate adenylate cyclase even in the presence of guanyl nucleotides. These data confirm the presence of LH-RH receptor sites on pituitary plasma membranes and suggest that LH-RH-induced gonadotrophin release may be mediated by mechanisms other than activation of adenylate cyclase.

  12. Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers

    NARCIS (Netherlands)

    Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

    1999-01-01

    The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

  13. Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers.

    NARCIS (Netherlands)

    Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

    1999-01-01

    The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

  14. The effect of restricted suckling on LH and ovarian steroids after ...

    African Journals Online (AJOL)

    time inseminations, and to decrease the incidence of 'short' oestrous cycles following GnRh.Tonic luteinizing hormone. (LH) levels, the release of LH in response to GnRh and oestro- .... fixed-time insemination was performed. The cows were rec- ..... growth rates in the calves between birth and 90 days were not affected by ...

  15. Hospital-Based Coalition to Improve Regional Surge Capacity

    Directory of Open Access Journals (Sweden)

    James M. Learning

    2012-12-01

    Full Text Available Introduction: Surge capacity for optimization of access to hospital beds is a limiting factor in response to catastrophic events. Medical facilities, communication tools, manpower, and resource reserves exist to respond to these events. However, these factors may not be optimally functioning to generate an effective and efficient surge response. The objective was to improve the function of these factors.Methods: Regional healthcare facilities and supporting local emergency response agencies developed a coalition (the Healthcare Facilities Partnership of South Central Pennsylvania; HCFP¬SCPA to increase regional surge capacity and emergency preparedness for healthcare facilities. The coalition focused on 6 objectives: (1 increase awareness of capabilities and assets, (2 develop and pilot test advanced planning and exercising of plans in the region, (3 augment written medical mutual aid agreements, (4 develop and strengthen partnership relationships, (5 ensure National Incident Management System compliance, and (6 develop and test a plan for effective utilization of volunteer healthcare professionals.Results: In comparison to baseline measurements, the coalition improved existing areas covered under all 6 objectives documented during a 24-month evaluation period. Enhanced communications between the hospital coalition, and real-time exercises, were used to provide evidence of improved preparedness for putative mass casualty incidents.Conclusion: The HCFP-SCPA successfully increased preparedness and surge capacity through a partnership of regional healthcare facilities and emergency response agencies.

  16. Surge and selection: power in the refugee resettlement regime

    OpenAIRE

    Annelisa Lindsay

    2017-01-01

    There is an imbalance of power – and a resulting lack of agency for refugees – in the structure of the current resettlement regime. The top-down process of selection also poses ethical dilemmas, as recent surges in resettlement operations show.

  17. Model simulation of storm surge potential for Andaman islands

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, V.S.; RameshBabu, V.; Babu, M.T.; Dhinakaran, G.; Rajamanickam, G.V.

    Hydraulics and Oceanography, the Hydrodynamics Module Reference Manual. DHI Water and Environment, Horsholm, Denmark, 58 p. Dube, S.K., Sinha, P C , Rao, A.D., and Rao, G.S., 1985. Numerical modeling of storm surges in the Arabian Sea, Appl. Math Modelling, 9...

  18. Multidimensional Numerical Modeling of Surges Over Initially Dry Land

    National Research Council Canada - National Science Library

    Berger, R

    2004-01-01

    .... The first test case is for a straight flume and the second contains a reservoir and a horseshoe channel section. It is important that the model match the timing of the surge as well as the height In both cases the ADH compared closely with the flume results.

  19. Into the Surge of Network-driven Innovation

    DEFF Research Database (Denmark)

    Østergaard, Claus Møller; Rosenstand, Claus Andreas Foss; Gertsen, Frank

    2013-01-01

    this is examined from the 1880’s up until today. The contribution of the paper is a societal perspective on innovation, where the difference between industrial society and knowledge society leads into the surge of network-driven innovation. Network-driven innovation is unfolded on top of the known cost- driven...

  20. Surge of plasma waves in an inhomogeneous plasma

    International Nuclear Information System (INIS)

    Benhassine, Mohammed

    1985-01-01

    The first part of this research thesis addresses the propagation of waves in a plasma. It presents the equation of propagation of an electromagnetic wave in a plasma without magnetic field, and analyses the propagation in an inhomogeneous medium. The second part addresses the wave-particle interaction: interaction between electrons and an electromagnetic wave, between electrons and an electrostatic wave (trapping), and between electrons and a localised electric field. The third chapter presents the analytic theory of oscillations of a cold plasma (macroscopic equations in Lagrangian coordinates, analytic solution before surge). The next chapter discusses physical interpretations before the wave surge, after the wave surge, and about energy exchange (within or outside of resonance). Numerical simulations and their results are then reported and discussed. The sixth chapter addresses the case of an electrostatic wave surge in a hot plasma. It notably addresses the following aspects: equivalence between the description of moments and the Waterbag model, interaction between non linearity and thermal effects, variation of electric field amplitude with temperature. Results of numerical simulations are presented, and the last part addresses experimental predictions for microwaves-plasma interaction and laser-matter interaction [fr

  1. On the Response of Interleaved Transformer Windings to Surge Voltages

    DEFF Research Database (Denmark)

    Pedersen, A.

    1963-01-01

    The high series capacitance theory for the response of interleaved transformer windings to surge voltages is criticized from the point of view that an increased series capacitance as a result of interleaving is incompatible with the concept of a pure capacitive initial voltage distribution. A new...

  2. Surge ammonium uptake in macroalgae from a coral atoll

    Digital Repository Service at National Institute of Oceanography (India)

    Raikar, V.; Wafar, M.V.M.

    of Phycology 36, 680?685. Crossland, C.J., Hatcher, B.G., Smith, S.V., 1991. Role of coral reefs in global ocean production. Coral Reefs 10, 55-64. Danilo, Dy. T., Yap, H.T., 2001. Surge ammonium uptake of the cultured seaweed, Kappaphycus alvarezii (Doty...

  3. Monitoring Inland Storm Surge and Flooding from Hurricane Rita

    Science.gov (United States)

    McGee, Benton D.; Tollett, Roland W.; Mason, Jr., Robert R.

    2006-01-01

    Pressure transducers (sensors) and high-water marks were used to document the inland water levels related to storm surge generated by Hurricane Rita in southwestern Louisiana and southeastern Texas. On September 22-23, 2005, an experimental monitoring network of sensors was deployed at 33 sites over an area of about 4,000 square miles to record the timing, extent, and magnitude of inland hurricane storm surge and coastal flooding. Sensors were programmed to record date and time, temperature, and barometric or water pressure. Water pressure was corrected for changes in barometric pressure and salinity. Elevation surveys using global-positioning systems and differential levels were used to relate all storm-surge water-level data, reference marks, benchmarks, sensor measuring points, and high-water marks to the North American Vertical Datum of 1988 (NAVD 88). The resulting data indicated that storm-surge water levels over 14 feet above NAVD 88 occurred at three locations, and rates of water-level rise greater than 5 feet per hour occurred at three locations near the Louisiana coast.

  4. Evaluation of surge transferred overvoltages in distribution transformers

    NARCIS (Netherlands)

    Popov, M.; Sluis, van der L.; Smeets, R.P.P.

    2008-01-01

    The paper presents an analysis of very fast-transient overvoltages that occur because of the capacitive surge transfer from the high-voltage (HV) transformer winding to the low-voltage (LV) transformer winding. The study is done on a 6.6 kV single-phase test transformer. By applying a pulse with a

  5. Tide-surge Interaction Intensified by the Taiwan Strait

    Science.gov (United States)

    Zhang, Wen-Zhou; Shi, Fengyan; Hong, Hua-Sheng; Shang, Shao-Ping; Kirby, James T.

    2010-06-01

    The Taiwan Strait is a long and wide shelf-channel where the hydrodynamics is extremely complex, being characterized by strong tides, and where storm surges frequently occur during the typhoon season. Obvious oscillations due to tide-surge interaction were observed by tide gauges along the northern Fujian coast, the west bank of the Taiwan Strait, during Typhoon Dan (1999). Numerical experiments indicate that nonlinear bottom friction (described by the quadratic formula) is a major factor to predict these oscillations while the nonlinear advective terms and the shallow water effect have little contribution. It is found that the tide-surge interaction in the northern portion of the Taiwan Strait is intensified by the strait. Simulations based on simplified topographies with and without the island of Taiwan show that, in the presence of the island, the channel effect strengthens tidal currents and tends to align the major axes of tidal ellipses along the channel direction. Storm-induced currents are also strengthened by the channel. The pattern of strong tidal currents and storm-induced currents along the channel direction enhances tide-surge interaction via the nonlinear bottom friction, resulting in the obvious oscillations along the northern Fujian coast.

  6. 14 CFR 33.65 - Surge and stall characteristics.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Surge and stall characteristics. 33.65 Section 33.65 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... stall characteristics. When the engine is operated in accordance with operating instructions required by...

  7. 30 CFR 77.209 - Surge and storage piles.

    Science.gov (United States)

    2010-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Surface... a reclaiming area or in any other area at or near a surge or storage pile where the reclaiming...

  8. Surge control of the electrically driven centrifugal compressor

    NARCIS (Netherlands)

    Boinov, K.O.; Lomonova, E.A.; Vandenput, A.J.A.; Tyagounov, A.

    2006-01-01

    This paper presents a method of the energy efficiency and the operational performance improvement of the electrically driven air compression system. The key innovation of the proposed method-the active surge suppression of the centrifugal compressor by means of the speed control of the electrical

  9. Aging assessment of surge protective devices in nuclear power plants

    International Nuclear Information System (INIS)

    Davis, J.F.; Subudhi, M.; Carroll, D.P.

    1996-01-01

    An assessment was performed to determine the effects of aging on the performance and availability of surge protective devices (SPDs), used in electrical power and control systems in nuclear power plants. Although SPDs have not been classified as safety-related, they are risk-important because they can minimize the initiating event frequencies associated with loss of offsite power and reactor trips. Conversely, their failure due to age might cause some of those initiating events, e.g., through short circuit failure modes, or by allowing deterioration of the safety-related component(s) they are protecting from overvoltages, perhaps preventing a reactor trip, from an open circuit failure mode. From the data evaluated during 1980--1994, it was found that failures of surge arresters and suppressers by short circuits were neither a significant risk nor safety concern, and there were no failures of surge suppressers preventing a reactor trip. Simulations, using the ElectroMagnetic Transients Program (EMTP) were performed to determine the adequacy of high voltage surge arresters

  10. In vitro regulation of LH biosynthesis and release by GnRH and estradiol

    International Nuclear Information System (INIS)

    Ramey, J.W.

    1986-01-01

    Anterior pituitaries were taken from female rats at random stages of the estrous cycle, enzymatically dispersed, and cultured for 48h in steroid-free α-modified Eagles medium followed by 24h in fresh medium +/- estradiol (E 2 ). The pituitary cells were then incubated in fresh medium containing radiolabeled precursors +/- gonadotropin releasing hormone (GnRH). Radioactive precursor incorporation into LH was determined by immuno-precipitation. The dose-dependent effects of E 2 (10 -11 to 10 -8 M) on 3 H-glucosamine ( 3 H-Gln) and 35 S-methionine ( 35 S-Met) incorporation into LH +/- 1 nM GnRH (4h) were investigated. GnRH (10 -9 M) and E 2 (all doses) significantly increased total 3 H-Gln LH. Moreover, E 2 at 10 -9 M and 10 -8 M significantly enhanced GnRH stimulated LH glycosylation. In contrast, addition of GnRH and/or E 2 did not significantly increase 35 S-Met incorporation into LH over a 4h period. The effects of various GnRH concentrations (10 -11 to 10 -9 M; 8h) +/- E 2 (0.05 nM) on 3 H-Gln LH and 35 S-Met LH production were also investigated. In the absence of E 2 , only 10 -9 M GnRH was effective in increasing total 3 H-Gln LH and 35 S-Met LH synthesis. However, in the presence of E 2 , all concentrations of GnRH stimulated LH synthesis with 3 H-Gln LH production responding in a dose related manner whereas 35 S-Met LH production was maximally stimulated at all doses of GnRH. In the final series of experiments, pituitary cells previously exposed to estradiol were incubated for 4 h in normal calcium or low calcium medium containing 3 H-Gln or 35 S-Met +/- GnRH. Removal of extracellular calcium completely inhibited GnRH stimulated 3 H-Gln LH and 35 S-Met LH production

  11. Distribution of auroral surges in the evening sector

    International Nuclear Information System (INIS)

    Kidd, S.R.; Rostoker, G.

    1991-01-01

    Over the past dacades a large statistical data base has been gathered consisting of both ground-based magnetometer and all-sky camera records from which researchers have inferred the distribution of substorm expansive phase events across the nighttime sector. Almost without exception, the activity distribution has been based on single station data acquired over periods of years. However, to truly establish the occurrence frequency of substorm expansive phase events, it is necessary to view the entire nighttime sector instantaneously in the light of evidence which shows that more than one expansive phase disturbance can be in progress across the broad expanse of the evening sector. In this paper, the authors study the distribution of regions of localized auroral luminosity in the poleward portion of the evening sectorauroral oval using images in the ultraviolet portion of the auroral spectrum acquired by the Viking satellite over 9 months in 1986. They find that auroral surge activity peaks in the hour before local magnetic midnight, with the probability of detecting a surge steadily decreasing to 10% of the probability of finding a surge in the hour prior to midnight as one moves westward towards 1,900 MLT. They show that their conclusion is not dependent on the threshold chosen for surge identification over a reasonable portion of the intensity range covered by the Viking imager. They further show that for the interval of several months near sunspot minimum in 1986 there is better than a 90% chance that no surge will be detected in a 1-hour range of magnetic local time if one were to sample that segment of the auroral oval at any arbitrary time

  12. Assessment of water pipes durability under pressure surge

    Science.gov (United States)

    Pham Ha, Hai; Minh, Lanh Pham Thi; Tang Van, Lam; Bulgakov, Boris; Bazhenova, Soafia

    2017-10-01

    Surge phenomenon occurs on the pipeline by the closing valve or pump suddenly lost power. Due to the complexity of the water hammer simulation, previous researches have only considered water hammer on the single pipe or calculation of some positions on water pipe network, it have not been analysis for all of pipe on the water distribution systems. Simulation of water hammer due to closing valve on water distribution system and the influence level of pressure surge is evaluated at the defects on pipe. Water hammer on water supply pipe network are simulated by Water HAMMER software academic version and the capacity of defects are calculated by SINTAP. SINTAP developed from Brite-Euram projects in Brussels-Belgium with the aim to develop a process for assessing the integrity of the structure for the European industry. Based on the principle of mechanical fault, indicating the size of defects in materials affect the load capacity of the product in the course of work, the process has proposed setting up the diagram to fatigue assessment defect (FAD). The methods are applied for water pipe networks of Lien Chieu district, Da Nang city, Viet Nam, the results show the affected area of wave pressure by closing the valve and thereby assess the greatest pressure surge effect to corroded pipe. The SINTAP standard and finite element mesh analysis at the defect during the occurrence of pressure surge which will accurately assess the bearing capacity of the old pipes. This is one of the bases to predict the leakage locations on the water distribution systems. Amount of water hammer when identified on the water supply networks are decreasing due to local losses at the nodes as well as the friction with pipe wall, so this paper adequately simulate water hammer phenomena applying for actual water distribution systems. The research verified that pipe wall with defect is damaged under the pressure surge value.

  13. Evaluation of Loss Due to Storm Surge Disasters in China Based on Econometric Model Groups

    OpenAIRE

    Xue Jin; Xiaoxia Shi; Jintian Gao; Tongbin Xu; Kedong Yin

    2018-01-01

    Storm surge has become an important factor restricting the economic and social development of China’s coastal regions. In order to improve the scientific judgment of future storm surge damage, a method of model groups is proposed to refine the evaluation of the loss due to storm surges. Due to the relative dispersion and poor regularity of the natural property data (login center air pressure, maximum wind speed, maximum storm water, super warning water level, etc.), storm surge disaster is di...

  14. A Numerical Simulation of Extratropical Storm Surge and Hydrodynamic Response in the Bohai Sea

    OpenAIRE

    Ding, Yumei; Ding, Lei

    2014-01-01

    A hindcast of typical extratropical storm surge occurring in the Bohai Sea in October 2003 is performed using a three-dimensional (3D) Finite Volume Coastal Ocean Model (FVCOM). The storm surge model is forced by 10 m winds obtained from the Weather Research Forecasting (WRF) model simulation. It is shown that the simulated storm surge and tides agree well with the observations. The nonlinear interaction between the surge and astronomical tides, the spatial distribution of the max...

  15. Determining Storm Surge Return Periods: The Use of Evidence of Historic Events

    DEFF Research Database (Denmark)

    Madsen, Kristine S.; Sørensen, Carlo Sass; Schmith, Torben

    Storm surges are a major concern for many coastal communities, and rising levels of surges is a key concern in relation to climate change. The sea level of a statistical 100-year or 1000-year storm surge event and similar statistical measures are used for spatial planning and emergency preparedness...

  16. 30 CFR 56.16002 - Bins, hoppers, silos, tanks, and surge piles.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bins, hoppers, silos, tanks, and surge piles... MINES Materials Storage and Handling § 56.16002 Bins, hoppers, silos, tanks, and surge piles. (a) Bins, hoppers, silos, tanks, and surge piles, where loose unconsolidated materials are stored, handled or...

  17. 30 CFR 57.16002 - Bins, hoppers, silos, tanks, and surge piles.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bins, hoppers, silos, tanks, and surge piles... NONMETAL MINES Materials Storage and Handling § 57.16002 Bins, hoppers, silos, tanks, and surge piles. (a) Bins, hoppers, silos, tanks, and surge piles, where loose unconsolidated materials are stored, handled...

  18. Coastal Storm Surge Analysis: Storm Forcing. Report 3. Intermediate Submission No. 1.3

    Science.gov (United States)

    2013-07-01

    The storm surge study considers both tropical storms and extratropical cyclones for determination of return period storm surge elevations. The...Appendix B: Extratropical Cyclone Selection in Support of FEMA Region III Storm Surge Modeling...stations applied in the storm selection process. ............................................. 56  Table B2. Extratropical cyclones selected from the

  19. Close-in characteristics of LH2/LOX reactions

    Science.gov (United States)

    Riehl, W. A.; Ullian, L. J.

    1985-01-01

    In deriving shock overpressures from space vehicles employing LH2 and LOX, separate methods of analyses and prediction are recommended, as a function of the distance. Three methods of treatment are recommended. For the Far Field - where the expected shock overpressure is less than 40 psi (lambda = 5) - use the classical PYRO approach to determine TNT yield, and employ classical ordnance (Kingery) curve to obtain the overall value. For the Close-In Range, a suggested limit is 3D, or a zone from a distance of three times the tank diameter to the tank wall. Rather than estimate a specific distance from the center of explosion to the target, it is only necessary to estimate whether this could be within one, two, or three diameters away from the wall; i.e., in the 1, 2, or 3D zone. Then assess whether mixing mode is by the PYRO CBGS (spill) mode or CBM (internal mixing) mode. From the zone and mixing mode, the probability of attaining various shock overpressures is determined from the plots provided herein. For the transition zone, between 40 psi and the 3D distance, it is tentatively recommended that both of the preceding methods be used, and to be conservative, the higher resulting value be used.

  20. Hybrid Composites for LH2 Fuel Tank Structure

    Science.gov (United States)

    Grimsley, Brian W.; Cano, Roberto J.; Johnston, Norman J.; Loos, Alfred C.; McMahon, William M.

    2001-01-01

    The application of lightweight carbon fiber reinforced plastics (CFRP) as structure for cryogenic fuel tanks is critical to the success of the next generation of Reusable Launch Vehicles (RLV). The recent failure of the X-33 composite fuel tank occurred in part due to microcracking of the polymer matrix, which allowed cryogen to permeate through the inner skin to the honeycomb core. As part of an approach to solve these problems, NASA Langley Research Center (LaRC) and Marshall Space Flight Center (MSFC) are working to develop and investigate polymer films that will act as a barrier to the permeation of LH2 through the composite laminate. In this study two commercially available films and eleven novel LaRC films were tested in an existing cryogenics laboratory at MSFC to determine the permeance of argon at room temperature. Several of these films were introduced as a layer in the composite to form an interleaved, or hybrid, composite to determine the effects on permeability. In addition, the effects of the interleaved layer thickness, number, and location on the mechanical properties of the composite laminate were investigated. In this initial screening process, several of the films were found to exhibit lower permeability to argon than the composite panels tested.

  1. Anaerobic Transformation of Furfural by Methanococcus deltae (Delta)LH

    Science.gov (United States)

    Belay, N.; Boopathy, R.; Voskuilen, G.

    1997-01-01

    Methanococcus deltae (Delta)LH was grown on H(inf2)-CO(inf2) in the presence of various concentrations of furfural. Furfural at higher concentrations, namely, 20 and 25 mM, inhibited growth of this organism. At concentration of 5 and 10 mM, no inhibition of growth was observed. The other methanogens in this study were not inhibited by 10 mM furfural. Among the methanogens tested, M. deltae was capable of transforming furfural, whereas Methanobacterium thermoautotrophicum Marburg, Methanosarcina barkeri 227, Methanococcus thermolithotrophicus, and Methanobrevibacter ruminantium lacked this capability. One hundred percent removal of furfural was observed within 48 h of incubation in M. deltae cultures. The end product observed during furfural metabolism was furfuryl alcohol. An almost stoichiometric amount of furfuryl alcohol was produced by M. deltae. This transformation is likely to be of value in the detoxification of furfural and in its ultimate conversion to methane and CO(inf2) by anaerobic digestion. PMID:16535618

  2. Fetal programming: testosterone exposure of the female sheep during midgestation disrupts the dynamics of its adult gonadotropin secretion during the periovulatory period.

    Science.gov (United States)

    Savabieasfahani, Mozhgan; Lee, James S; Herkimer, Carol; Sharma, Tejinder P; Foster, Douglas L; Padmanabhan, Vasantha

    2005-01-01

    Prenatal exposure of the female sheep to excess testosterone (T) leads to hypergonadotropism, multifollicular ovaries, and progressive loss of reproductive cycles. We have determined that prenatal T treatment delays the latency of the estradiol (E2)-induced LH surge. To extend this finding into a natural physiological context, the present study was conducted to determine if the malprogrammed surge mechanism alters the reproductive cycle. Specifically, we wished to determine if prenatal T treatment 1) delays the onset of the preovulatory gonadotropin surge during the natural follicular phase rise in E2, 2) alters pulsatile LH secretion and the dynamics of the secondary FSH surge, and 3) compromises the ensuing luteal function. Females prenatally T-treated from Day 60 to Day 90 of gestation (147 days is term) and control females were studied when they were approximately 2.5 yr of age. Reproductive cycles of control and prenatally T-treated females were synchronized with PGF2alpha, and peripheral blood samples were collected every 2 h for 120 h to characterize cyclic changes in E2, LH, and FSH and then daily for 14 days to monitor changes in luteal progesterone. To assess LH pulse patterns, blood samples were also collected frequently (each 5 min for 6 h) during the follicular and luteal phases of the cycle. The results revealed that, in prenatally T-treated females, 1) the preovulatory increase in E2 was normal; 2) the latencies between the preovulatory increase in E2 and the peaks of the primary LH and FSH surges were longer, but the magnitudes similar; 3) follicular-phase LH pulse frequency was increased; 4) the interval between the primary and secondary FSH surges was reduced but there was a tendency for an increase in duration of the secondary FSH surge; but 5) luteal progesterone patterns were in general unaltered. Thus, exposure of the female to excess T before birth produces perturbances and maltiming in periovulatory gonadotropin secretory dynamics, but these

  3. The cytoskeleton proteins and LH-regulated steroidogenesis in porcine luteal cells

    International Nuclear Information System (INIS)

    Gregoraszczuk, Ewa L.; Slomczynska, Maria

    1996-01-01

    The involvement of microtubules (MT) and microflilaments (MF) in LH-regulation of luteal cell stereoidogenesis was assessed at the middle stage of corpus luteum development. The influence microtubule- and microfilament-altering agents on basal and LH-stimulated progesterone (P4) production and secretion into the incubation medium was determined by RIA. LH-stimulated P4 production was 2.5 times higher than in the control cultures. Cytochalasis B (Cyt B) was without effect on basal P4 synthesis but increased the basal fraction of P4 secreted into the incubation medium, while colchicine (Col) increased both basal P4 synthesis and the fraction of P4 secreted into the incubation medium. LH-stimulated progesterone synthesis was reduced by Col, but the fraction secreted into the incubation medium increased. Cyt B had no effect on LH-stimulated synthesis but it decreased the fraction of P4 secreted into the incubation medium. Our findings demonstrate significant differences in the effect of Cyt B and Col on steroidogenesis in corpus luteum. We conclude that microtubules play an important role in the process of LH-stimulated P4 synthesis, while microfilaments act in the process of basal and LH-stimulated P4 secretion. (author). 23 refs, 4 figs

  4. Proinflammatory Cytokine Infusion Attenuates LH's Feedforward on Testosterone Secretion: Modulation by Age.

    Science.gov (United States)

    Veldhuis, Johannes; Yang, Rebecca; Roelfsema, Ferdinand; Takahashi, Paul

    2016-02-01

    In the experimental animal, inflammatory signals quench LH's feedforward drive of testosterone (T) secretion and appear to impair GnRH-LH output. The degree to which such suppressive effects operate in the human is not known. To test the hypothesis that IL-2 impairs LH's feedforward drive on T and T's feedback inhibition of LH secretion in healthy men. Mayo Center for Translational Science Activities. A total of 35 healthy men, 17 young and 18 older. Randomized prospective double-blind saline-controlled study of IL-2 infusion in 2 doses with concurrent 10-minute blood sampling for 24 hours. Deconvolution analysis of LH and T secretion. After saline injection, older compared with young men exhibited reduced LH feedforward drive on T secretion (P enforces biochemical hypogonadism, viz, combined feedforward block and feedback amplification; and 2) unequal absolute inhibition of T and LH secretion by IL-2 in young and older men. These outcomes establish that the male gonadal axis is susceptible to dual-site suppression by a prototypic inflammatory mediator. Thus, we postulate that selected ILs might also enforce male hypogonadism in chronic systemic inflammation.

  5. Effect of LH and prolactin on steroid secretion by perifused luteal tissue from pregnant gilts with induced hypoprolactinemia or after passive immunoneutralization of LH

    International Nuclear Information System (INIS)

    Szafranska, B.; Przala, J.; Grazul-Bilska, A.

    1992-01-01

    The study was performed using luteal tissue obtained from 24 pregnant gilts. Group 1 was treated with bromocriptine (BR) from 37th to 42nd day of day of pregnancy. Group 2 was treated with homologous anti-pLH serum from 37th to 42nd day of pregnancy. Group 3 was given BR from 67th to 72nd day of gestation. Group 4 received anti-pLH serum from 67th to 72nd day of pregnancy. The effect of exogenous LH or prolactin (100 ng/ml) on secretion of progesterone (P 4 ) and estradiol (E 2 ) by luteal tissue was studied using perfusion technique. Prolactin caused a significant (P 4 secretion by luteal tissue from gilts in groups 1 and 4. Both LH and prolactin decreased (P 4 and E 2 secretion by luteal tissue from gilts from groups 4 and 2, respectively. The results demonstrate that both LH and prolactin have a regulatory role in steroid secretion by luteal tissue of gilts in the mid- and late period of pregnancy. (author). 28 refs, 2 figs

  6. Weak evidence of bright light effects on human LH and FSH

    Directory of Open Access Journals (Sweden)

    Kripke Daniel F

    2010-05-01

    Full Text Available Abstract Background Most mammals are seasonal breeders whose gonads grow to anticipate reproduction in the spring and summer. As day length increases, secretion increases for two gonadotropins, luteinizing hormone (LH and follicle stimulating hormone (FSH. This response is largely controlled by light. Light effects on gonadotropins are mediated through effects on the suprachiasmatic nucleus and responses of the circadian system. There is some evidence that seasonal breeding in humans is regulated by similar mechanisms, and that light stimulates LH secretion, but primate responses seem complex. Methods To gain further information on effects of bright light on LH and FSH secretion in humans, we analyzed urine samples collected in three experiments conducted for other goals. First, volunteers ages 18-30 years and 60-75 commenced an ultra-short 90-min sleep-wake cycle, during which they were exposed to 3000 lux light for 3 hours at balanced times of day, repeated for 3 days. Urine samples were assayed to explore any LH phase response curve. Second, depressed participants 60-79 years of age were treated with bright light or dim placebo light for 28 days, with measurements of urinary LH and FSH before and after treatment. Third, women of ages 20-45 years with premenstrual dysphoric disorder (PMDD were treated to one 3-hour exposure of morning light, measuring LH and FSH in urine before and after the treatments. Results Two of the three studies showed significant increases in LH after light treatment, and FSH also tended to increase, but there were no significant contrasts with parallel placebo treatments and no significant time-of-day treatment effects. Conclusions These results gave some support for the hypothesis that bright light may augment LH secretion. Longer-duration studies may be needed to clarify the effects of light on human LH and FSH.

  7. Weak evidence of bright light effects on human LH and FSH.

    Science.gov (United States)

    Kripke, Daniel F; Elliott, Jeffrey A; Youngstedt, Shawn D; Parry, Barbara L; Hauger, Richard L; Rex, Katharine M

    2010-05-11

    Most mammals are seasonal breeders whose gonads grow to anticipate reproduction in the spring and summer. As day length increases, secretion increases for two gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH). This response is largely controlled by light. Light effects on gonadotropins are mediated through effects on the suprachiasmatic nucleus and responses of the circadian system. There is some evidence that seasonal breeding in humans is regulated by similar mechanisms, and that light stimulates LH secretion, but primate responses seem complex. To gain further information on effects of bright light on LH and FSH secretion in humans, we analyzed urine samples collected in three experiments conducted for other goals. First, volunteers ages 18-30 years and 60-75 commenced an ultra-short 90-min sleep-wake cycle, during which they were exposed to 3000 lux light for 3 hours at balanced times of day, repeated for 3 days. Urine samples were assayed to explore any LH phase response curve. Second, depressed participants 60-79 years of age were treated with bright light or dim placebo light for 28 days, with measurements of urinary LH and FSH before and after treatment. Third, women of ages 20-45 years with premenstrual dysphoric disorder (PMDD) were treated to one 3-hour exposure of morning light, measuring LH and FSH in urine before and after the treatments. Two of the three studies showed significant increases in LH after light treatment, and FSH also tended to increase, but there were no significant contrasts with parallel placebo treatments and no significant time-of-day treatment effects. These results gave some support for the hypothesis that bright light may augment LH secretion. Longer-duration studies may be needed to clarify the effects of light on human LH and FSH.

  8. Characterisation of the LH2 spectral variants produced by the photosynthetic purple sulphur bacterium Allochromatium vinosum.

    Science.gov (United States)

    Carey, Anne-Marie; Hacking, Kirsty; Picken, Nichola; Honkanen, Suvi; Kelly, Sharon; Niedzwiedzki, Dariusz M; Blankenship, Robert E; Shimizu, Yuuki; Wang-Otomo, Zheng-Yu; Cogdell, Richard J

    2014-11-01

    This study systematically investigated the different types of LH2 produced by Allochromatium (Alc.) vinosum, a photosynthetic purple sulphur bacterium, in response to variations in growth conditions. Three different spectral forms of LH2 were isolated and purified, the B800-820, B800-840 and B800-850 LH2 types, all of which exhibit an unusual split 800 peak in their low temperature absorption spectra. However, it is likely that more forms are also present. Relatively more B800-820 and B800-840 are produced under low light conditions, while relatively more B800-850 is produced under high light conditions. Polypeptide compositions of the three different LH2 types were determined by a combination of HPLC and TOF/MS. The B800-820, B800-840 and B800-850 LH2 types all have a heterogeneous polypeptide composition, containing multiple types of both α and β polypeptides, and differ in their precise polypeptide composition. They all have a mixed carotenoid composition, containing carotenoids of the spirilloxanthin series. In all cases the most abundant carotenoid is rhodopin; however, there is a shift towards carotenoids with a higher conjugation number in LH2 complexes produced under low light conditions. CD spectroscopy, together with the polypeptide analysis, demonstrates that these Alc. vinosum LH2 complexes are more closely related to the LH2 complex from Phs. molischianum than they are to the LH2 complexes from Rps. acidophila. Copyright © 2014. Published by Elsevier B.V.

  9. Energy transfer dynamics in an RC-LH1-PufX tubular photosynthetic membrane

    Energy Technology Data Exchange (ETDEWEB)

    Hsin, J; Sener, M; Schulten, K [Department of Physics and Beckman Institute, University of Illinois at Urbana-Champaign, Urbana (United States); Struempfer, J [Center for Biophysics and Computational Biology and Beckman Institute, University of Illinois at Urbana-Champaign, Urbana (United States); Qian, P; Hunter, C N, E-mail: kschulte@ks.uiuc.ed [Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN (United Kingdom)

    2010-08-15

    Light absorption and the subsequent transfer of excitation energy are the first two steps in the photosynthetic process, carried out by protein-bound pigments, mainly bacteriochlorophylls (BChls), in photosynthetic bacteria. BChls are anchored in light-harvesting (LH) complexes, such as light-harvesting complex I (LH1), which directly associates with the reaction center (RC), forming the RC-LH1 core complex. In Rhodobacter sphaeroides, RC-LH1 core complexes contain an additional protein, PufX, and assemble into dimeric RC-LH1-PufX core complexes. In the absence of LH complex II (LH2), the former complexes can aggregate into a helically ordered tubular photosynthetic membrane. We have examined the excitation transfer dynamics in a single RC-LH1-PufX core complex dimer using the hierarchical equations of motion for dissipative quantum dynamics that accurately, yet in a computationally costly manner, treat the coupling between BChls and their protein environment. A widely employed description, the generalized Foerster (GF) theory, was also used to calculate the transfer rates of the same excitonic system in order to verify the accuracy of this computationally cheap method. Additionally, in light of the structural uncertainties in the Rba. sphaeroides RC-LH1-PufX core complex, geometrical alterations were introduced into the BChl organization. It is shown that the energy transfer dynamics are not affected by the considered changes in the BChl organization and that the GF theory provides accurate transfer rates. An all-atom model for a tubular photosynthetic membrane is then constructed on the basis of electron microscopy data, and the overall energy transfer properties of this membrane are computed.

  10. Energy transfer dynamics in an RC-LH1-PufX tubular photosynthetic membrane

    International Nuclear Information System (INIS)

    Hsin, J; Sener, M; Schulten, K; Struempfer, J; Qian, P; Hunter, C N

    2010-01-01

    Light absorption and the subsequent transfer of excitation energy are the first two steps in the photosynthetic process, carried out by protein-bound pigments, mainly bacteriochlorophylls (BChls), in photosynthetic bacteria. BChls are anchored in light-harvesting (LH) complexes, such as light-harvesting complex I (LH1), which directly associates with the reaction center (RC), forming the RC-LH1 core complex. In Rhodobacter sphaeroides, RC-LH1 core complexes contain an additional protein, PufX, and assemble into dimeric RC-LH1-PufX core complexes. In the absence of LH complex II (LH2), the former complexes can aggregate into a helically ordered tubular photosynthetic membrane. We have examined the excitation transfer dynamics in a single RC-LH1-PufX core complex dimer using the hierarchical equations of motion for dissipative quantum dynamics that accurately, yet in a computationally costly manner, treat the coupling between BChls and their protein environment. A widely employed description, the generalized Foerster (GF) theory, was also used to calculate the transfer rates of the same excitonic system in order to verify the accuracy of this computationally cheap method. Additionally, in light of the structural uncertainties in the Rba. sphaeroides RC-LH1-PufX core complex, geometrical alterations were introduced into the BChl organization. It is shown that the energy transfer dynamics are not affected by the considered changes in the BChl organization and that the GF theory provides accurate transfer rates. An all-atom model for a tubular photosynthetic membrane is then constructed on the basis of electron microscopy data, and the overall energy transfer properties of this membrane are computed.

  11. Environment-assisted Quantum Critical Effect for Excitation Energy Transfer in a LH2-type Trimer

    Science.gov (United States)

    Xu, Lan; Xu, Bo

    2015-10-01

    In this article, we are investigating excitation energy transfer (EET) in a basic unit cell of light-harvesting complex II (LH2), named a LH2-type trimer. Calculation of energy transfer efficiency (ETE) in the framework of non-Markovian environment is also implemented. With these achievements, we theoretically predict the environment-assisted quantum critical effect, where ETE exhibits a sudden change at the critical point of quantum phase transition (QPT) for the LH2-type trimer. It is found that highly efficient EET with nearly unit efficiency may occur in the vicinity of the critical point of QPT.

  12. Effect of layout on surge line thermal stratification

    International Nuclear Information System (INIS)

    Lai Jianyong; Huang Wei

    2011-01-01

    In order to analyze and evaluate the effect of layout on the thermal stratification for PWR Pressurizer surge line, numerical simulation by Computational Fluid Dynamics (CFD) method is taken on 6 kinds of layout improvement with 2 improvement schemes, i.e., increasing the obliquity of quasi horizontal section and adding a vertical pipe between the quasi horizontal section and next elbow, and the maximum temperature differences of quasi horizontal section of surge line of various layouts under different flowrate are obtained. The comparison shows that, the increasing of the obliquity of quasi horizontal section can mitigate the thermal stratification phenomena but can not eliminate this phenomena, while the adding of a vertical pipe between the quasi horizontal section and next elbow can effectively mitigate and eliminate the thermal stratification phenomena. (authors)

  13. Thermal stratification and fatigue stress analysis for pressurizer surge line

    International Nuclear Information System (INIS)

    Yu Xiaofei; Zhang Yixiong

    2011-01-01

    Thermal stratification of pressurizer surge line induced by the inside fluid results in the global bending moments, local thermal stresses, unexpected displacements and support loadings of the pipe system. In order to avoid a costly three-dimensional computation, a combined 1D/2D technique has been developed and implemented to analyze the thermal stratification and fatigue stress of pressurize surge line of QINSHAN Phase II Extension Nuclear Power Project in this paper, using the computer codes SYSTUS and ROCOCO. According to the mechanical analysis results of stratification, the maximum stress and cumulative usage factor are obtained. The results indicate that the stress and fatigue intensity considering thermal stratification satisfies RCC-M criterion. (authors)

  14. Use of historical information in extreme storm surges frequency analysis

    Science.gov (United States)

    Hamdi, Yasser; Duluc, Claire-Marie; Deville, Yves; Bardet, Lise; Rebour, Vincent

    2013-04-01

    The prevention of storm surge flood risks is critical for protection and design of coastal facilities to very low probabilities of failure. The effective protection requires the use of a statistical analysis approach having a solid theoretical motivation. Relating extreme storm surges to their frequency of occurrence using probability distributions has been a common issue since 1950s. The engineer needs to determine the storm surge of a given return period, i.e., the storm surge quantile or design storm surge. Traditional methods for determining such a quantile have been generally based on data from the systematic record alone. However, the statistical extrapolation, to estimate storm surges corresponding to high return periods, is seriously contaminated by sampling and model uncertainty if data are available for a relatively limited period. This has motivated the development of approaches to enlarge the sample extreme values beyond the systematic period. The nonsystematic data occurred before the systematic period is called historical information. During the last three decades, the value of using historical information as a nonsystematic data in frequency analysis has been recognized by several authors. The basic hypothesis in statistical modeling of historical information is that a perception threshold exists and that during a giving historical period preceding the period of tide gauging, all exceedances of this threshold have been recorded. Historical information prior to the systematic records may arise from high-sea water marks left by extreme surges on the coastal areas. It can also be retrieved from archives, old books, earliest newspapers, damage reports, unpublished written records and interviews with local residents. A plotting position formula, to compute empirical probabilities based on systematic and historical data, is used in this communication paper. The objective of the present work is to examine the potential gain in estimation accuracy with the

  15. The destruction influence of pulse and surge currents on overvoltage protection

    International Nuclear Information System (INIS)

    Glasa, M.; Huettner, L.

    2012-01-01

    This article deals about the influences caused during the active operation process of the surge arrester against the pulse and surge currents. It also refers about a lightning, the characteristic of lightning and about the lightning (surge) currents caused its influence. One parts of the article is focused on a total elimination of surge current energy, and on an ineffective operation, which leads to partially or totally destruction of a protection element. There is a comparison with two basic types of surge arresters (spark gap and varistor based arresters), and theirs re-effectiveness on prescribed level. (Authors)

  16. Hospitals Capability in Response to Disasters Considering Surge Capacity Approach

    Directory of Open Access Journals (Sweden)

    Gholamreza Khademipour

    2016-01-01

    Full Text Available Background: The man-made and natural disasters have adverse effects with sound, apparent, and unknown consequences. Among various components of disaster management in health sector, the most important role is performed by health-treatment systems, especially hospitals. Therefore, the present study aimed to evaluate the surge capacity of hospitals of Kerman Province in disaster in 2015. Materials and Methods: This is a quantitative study, conducted on private, military, and medical sciences hospitals of Kerman Province. The sampling method was total count and data collection for the research was done by questionnaire. The first section of the questionnaire included demographic information of the studied hospitals and second part examined the hospital capacity in response to disasters in 4 fields of equipment, physical space, human resources, and applied programs. The extracted data were analyzed by descriptive statistics. Results: The mean capability of implementing the surge capacity programs by hospitals of Kerman Province in disasters and in 4 fields of equipment, physical space, human resources, and applied programs was evaluated as 7.33% (weak. The surge capacity capability of state hospitals in disasters was computed as 8% and compared to private hospitals (6.07% had a more suitable condition. Conclusion: Based on the results of study and significance of preparedness of hospitals in response to disasters, it is proposed that managers of studied hospitals take measures to promote the hospital response capacity to disasters based on 4 components of increasing hospital capacity.

  17. Protein Structural Deformation Induced Lifetime Shortening of Photosynthetic Bacteria Light-Harvesting Complex LH2 Excited State

    OpenAIRE

    Chen, Xing-Hai; Zhang, Lei; Weng, Yu-Xiang; Du, Lu-Chao; Ye, Man-Ping; Yang, Guo-Zhen; Fujii, Ritsuko; Rondonuwu, Ferdy S.; Koyama, Yasushi; Wu, Yi-Shi; Zhang, J. P.

    2005-01-01

    Photosynthetic bacterial light-harvesting antenna complex LH2 was immobilized on the surface of TiO2 nanoparticles in the colloidal solution. The LH2/TiO2 assembly was investigated by the time-resolved spectroscopic methods. The excited-state lifetimes for carotenoid-containing and carotenoidless LH2 have been measured, showing a decrease in the excited-state lifetime of B850 when LH2 was immobilized on TiO2. The possibility that the decrease of the LH2 excited-state lifetime being caused by ...

  18. Differences in Signal Activation by LH and hCG are Mediated by the LH/CG Receptor's Extracellular Hinge Region.

    Science.gov (United States)

    Grzesik, Paul; Kreuchwig, Annika; Rutz, Claudia; Furkert, Jens; Wiesner, Burkhard; Schuelein, Ralf; Kleinau, Gunnar; Gromoll, Joerg; Krause, Gerd

    2015-01-01

    The human lutropin (hLH)/choriogonadotropin (hCG) receptor (LHCGR) can be activated by binding two slightly different gonadotropic glycoprotein hormones, choriogonadotropin (CG) - secreted by the placenta, and lutropin (LH) - produced by the pituitary. They induce different signaling profiles at the LHCGR. This cannot be explained by binding to the receptor's leucine-rich-repeat domain (LRRD), as this binding is similar for the two hormones. We therefore speculate that there are previously unknown differences in the hormone/receptor interaction at the extracellular hinge region, which might help to understand functional differences between the two hormones. We have therefore performed a detailed study of the binding and action of LH and CG at the LHCGR hinge region. We focused on a primate-specific additional exon in the hinge region, which is located between LRRD and the serpentine domain. The segment of the hinge region encoded by exon10 was previously reported to be only relevant to hLH signaling, as the exon10-deletion receptor exhibits decreased hLH signaling, but unchanged hCG signaling. We designed an advanced homology model of the hormone/LHCGR complex, followed by experimental characterization of relevant fragments in the hinge region. In addition, we examined predictions of a helical exon10-encoded conformation by block-wise polyalanine (helix supporting) mutations. These helix preserving modifications showed no effect on hormone-induced signaling. However, introduction of a structure-disturbing double-proline mutant LHCGR-Q303P/E305P within the exon10-helix has, in contrast to exon10-deletion, no impact on hLH, but only on hCG signaling. This opposite effect on signaling by hLH and hCG can be explained by distinct sites of hormone interaction in the hinge region. In conclusion, our analysis provides details of the differences between hLH- and hCG-induced signaling that are mainly determined in the L2-beta loop of the hormones and in the hinge

  19. Differences in Signal Activation by LH and hCG are Mediated by the LH/CG Receptor’s Extracellular Hinge Region

    Science.gov (United States)

    Grzesik, Paul; Kreuchwig, Annika; Rutz, Claudia; Furkert, Jens; Wiesner, Burkhard; Schuelein, Ralf; Kleinau, Gunnar; Gromoll, Joerg; Krause, Gerd

    2015-01-01

    The human lutropin (hLH)/choriogonadotropin (hCG) receptor (LHCGR) can be activated by binding two slightly different gonadotropic glycoprotein hormones, choriogonadotropin (CG) – secreted by the placenta, and lutropin (LH) – produced by the pituitary. They induce different signaling profiles at the LHCGR. This cannot be explained by binding to the receptor’s leucine-rich-repeat domain (LRRD), as this binding is similar for the two hormones. We therefore speculate that there are previously unknown differences in the hormone/receptor interaction at the extracellular hinge region, which might help to understand functional differences between the two hormones. We have therefore performed a detailed study of the binding and action of LH and CG at the LHCGR hinge region. We focused on a primate-specific additional exon in the hinge region, which is located between LRRD and the serpentine domain. The segment of the hinge region encoded by exon10 was previously reported to be only relevant to hLH signaling, as the exon10-deletion receptor exhibits decreased hLH signaling, but unchanged hCG signaling. We designed an advanced homology model of the hormone/LHCGR complex, followed by experimental characterization of relevant fragments in the hinge region. In addition, we examined predictions of a helical exon10-encoded conformation by block-wise polyalanine (helix supporting) mutations. These helix preserving modifications showed no effect on hormone-induced signaling. However, introduction of a structure-disturbing double-proline mutant LHCGR-Q303P/E305P within the exon10-helix has, in contrast to exon10-deletion, no impact on hLH, but only on hCG signaling. This opposite effect on signaling by hLH and hCG can be explained by distinct sites of hormone interaction in the hinge region. In conclusion, our analysis provides details of the differences between hLH- and hCG-induced signaling that are mainly determined in the L2-beta loop of the hormones and in the

  20. Convection-type LH2 absorber R and D for muon ionization cooling

    International Nuclear Information System (INIS)

    Ishimoto, S.; Bandura, L.; Black, E.L.; Boghosian, M.; Cassel, K.W.; Cummings, M.A.; Darve, C.; Dyshkant, A.; Errede, D.; Geer, S.; Haney, M.; Hedin, D.; Johnson, R.; Johnstone, C.J.; Kaplan, D.M.; Kubik, D.; Kuno, Y.; Majewski, S.; Popovic, M.; Reep, M.; Summers, D.; Suzuki, S.; Yoshimura, K.

    2003-01-01

    A feasibility study on liquid hydrogen (LH 2 ) absorbers for muon ionization cooling is reported. In muon ionization cooling, an LH 2 absorber is required to have a high cooling power greater than 100 W to cool heat deposited by muons passing through. That heat in LH 2 can be removed at either external or internal heat exchangers, which are cooled by cold helium gas. As one of the internal heat exchanger types, a convection-type absorber is proposed. In the convection-type absorber, heat is taken away by the convection of LH 2 in the absorber. The heat exchanger efficiency for the convection-type absorber is calculated. A possible design is presented

  1. Convection-type LH{sub 2} absorber R and D for muon ionization cooling

    Energy Technology Data Exchange (ETDEWEB)

    Ishimoto, S. E-mail: shigeru.ishimoto@kek.jp; Bandura, L.; Black, E.L.; Boghosian, M.; Cassel, K.W.; Cummings, M.A.; Darve, C.; Dyshkant, A.; Errede, D.; Geer, S.; Haney, M.; Hedin, D.; Johnson, R.; Johnstone, C.J.; Kaplan, D.M.; Kubik, D.; Kuno, Y.; Majewski, S.; Popovic, M.; Reep, M.; Summers, D.; Suzuki, S.; Yoshimura, K

    2003-05-01

    A feasibility study on liquid hydrogen (LH{sub 2}) absorbers for muon ionization cooling is reported. In muon ionization cooling, an LH{sub 2} absorber is required to have a high cooling power greater than 100 W to cool heat deposited by muons passing through. That heat in LH{sub 2} can be removed at either external or internal heat exchangers, which are cooled by cold helium gas. As one of the internal heat exchanger types, a convection-type absorber is proposed. In the convection-type absorber, heat is taken away by the convection of LH{sub 2} in the absorber. The heat exchanger efficiency for the convection-type absorber is calculated. A possible design is presented.

  2. Experimental study of temperature sensor for an ocean-going liquid hydrogen (LH2) carrier

    Science.gov (United States)

    Nakano, A.; Shimazaki, T.; Sekiya, M.; Shiozawa, H.; Aoyagi, A.; Ohtsuka, K.; Iwakiri, T.; Mikami, Z.; Sato, M.; Kinoshita, K.; Matsuoka, T.; Takayama, Y.; Yamamoto, K.

    2018-04-01

    The prototype temperature sensors for an ocean-going liquid hydrogen (LH2) carrier were manufactured by way of trial. All of the sensors adopted Platinum 1000 (PT-1000) resistance thermometer elements. Various configurations of preproduction temperature sensors were tested in AIST's LH2 test facility. In the experiments, a PT-1000 resistance thermometer, calibrated at the National Metrology Institute of Japan at AIST, was used as the standard thermometer. The temperatures measured by the preproduction sensors were compared with the temperatures measured by the standard thermometer, and the measurement accuracy of the temperature sensors in LH2 was investigated and discussed. It was confirmed that the measurement accuracies of the preproduction temperature sensors were within ±50 mK, which is the required measurement accuracy for a technical demonstration ocean-going LH2 carrier.

  3. Correlation between FSH, LH and prolactin serum levels. [Radioimmunoassay of hormones

    Energy Technology Data Exchange (ETDEWEB)

    Krause, W [Giessen Univ. (Germany, F.R.)

    1978-01-01

    In 188 males FSH, LH, and prolactin serum levels determined by radioimmunoassay from a single blood sample were found to be closely correlated. No correlation appeared to testosterone levels. The same correlation is observed, if serum levels of FSH, LH, and prolactin are measured after stimulation with LH-RH and TRH. In order to explain the close correlation, in five young men hormone levels were measured at 2-min-intervals over a period of 2 hours. Peaks of prolactin often correspond to those of FSH and LH, and a statistical correlation was found in two cases between FSH and prolactin. Results suggest a common releasing mechanism, which is superposed to the main mediating mechanism.

  4. Intranasal LH-RH treatment of cryptorchidism. A clinical trial and 5 years follow-up

    DEFF Research Database (Denmark)

    Thorup, Jørgen Mogens; Mauritzen, K; Skakkebaek, N E

    1987-01-01

    The effect of intranasal LH-RH on cryptorchidism was investigated in 45 prepubertal boys with 68 undescended testes. A daily dose of 1.2 mg LH-RH was given for 4 weeks. A total of 16 testes (24%) descended. Follow-up examination 5 years later showed that relapse had occurred in two cases. Fifty......-two testes did not descend during the LH-RH treatment. However, seven of these testes descended spontaneously during puberty. So far surgical treatment has been carried out in 39 of the remaining 45 testes. Anatomical anomalies (ectopic position of the testis, open processus vaginalis, abnormal epididymis......) explained the failure of LH-RH to cause descent in the majority of the surgically treated cases....

  5. Early postnatal treatment of hypogonadotropic hypogonadism with recombinant human FSH and LH

    DEFF Research Database (Denmark)

    Main, Katharina M; Schmidt, Ida M; Toppari, Jorma

    2002-01-01

    BACKGROUND: Patients with hypogonadotropic hypogonadism may be diagnosed shortly after birth because of micropenis and cryptorchidism, combined with subnormal LH and FSH concentrations during the postnatal period. OBJECTIVE: To investigate whether treating these patients with gonadotropins postna...... observed. CONCLUSIONS: Gonadotropin treatment in an infant with hypogonadotropic hypogonadism succeeded in inducing an increase in inhibin B and testicular growth.......BACKGROUND: Patients with hypogonadotropic hypogonadism may be diagnosed shortly after birth because of micropenis and cryptorchidism, combined with subnormal LH and FSH concentrations during the postnatal period. OBJECTIVE: To investigate whether treating these patients with gonadotropins...... the normal range (0.05-0.17 IU/l and 79-112 pg/ml respectively). METHODS: From 7.9 to 13.7 months of age, the patient was treated with recombinant human LH and FSH in doses of 20 and 21.3 IU s.c. twice weekly respectively. RESULTS: During treatment concentrations of LH, FSH, inhibin B and estradiol increased...

  6. Direct Observation of Energy Detrapping in LH1-RC Complex by Two-Dimensional Electronic Spectroscopy.

    Science.gov (United States)

    Ma, Fei; Yu, Long-Jiang; Hendrikx, Ruud; Wang-Otomo, Zheng-Yu; van Grondelle, Rienk

    2017-01-18

    The purple bacterial core light harvesting antenna-reaction center (LH1-RC) complex is the simplest system able to achieve the entire primary function of photosynthesis. During the past decade, a variety of photosynthetic proteins were studied by a powerful technique, two-dimensional electronic spectroscopy (2DES). However, little attention has been paid to LH1-RC, although its reversible uphill energy transfer, trapping, and backward detrapping processes, represent a crucial step in the early photosynthetic reaction dynamics. Thus, in this work, we employed 2DES to study two LH1-RC complexes of Thermochromatium (Tch.) tepidum. By direct observation of detrapping, the complex reversible process was clearly identified and an overall scheme of the excitation evolution in LH1-RC was obtained.

  7. Small scale purification of human pituitary lutropin (hLH) for use in radioligand assays

    International Nuclear Information System (INIS)

    Schwarz, I.; Morgante, L.; Bartolini, P.

    1988-08-01

    Human lutropin (hLH) is a relatively unstable protein, which even in lyophilised form tends to dissociate into subunits during long storage periods. Considering the limited disposibilty of human pituitaries, a small-scale extraction method is proposed for radioassays. Starting from 10 and 20 hypophyses after Sephadex G 100 purification, 10 μg/gland with approximate 10% purity was obtained. After the last purification, hLH recovery was of 1.5 μg/gland. (author) [pt

  8. Normal levels of plasma FSH and LH in the menstrual cycle as determined by radioimmunoassay

    International Nuclear Information System (INIS)

    Lemgruber, I.; Pinto, J.C.M.; Linhares, E.; Granafer, A.

    1981-01-01

    The biological methods were not able to establish adequately the separate determination of FSH and LH. The introduction of radioimmunoassay had allowed the identification of plasma FSH and LH for the purpose of routine clinical use. The utilization of commercial kits, however, obliges each laboratory to have normal levels of his own. Such is the finality of this work, studying samples from 200 normal women, hospitalized for surgical reasons and having not any endocrinological problem. (author) [pt

  9. Empirical Profiling of Cold Hydrogen Plumes Formed from Venting Of LH2 Storage Vessels: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Buttner, William J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rivkin, Carl H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Schmidt, Kara [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hartmann, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wright, Hannah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Weidner, Eveline [Joint Research Centre, Petten, the Netherlands; Ciotti, Michael [H2 Fueling and CIP Markets Engineering

    2017-11-16

    Liquid hydrogen (LH2) storage is a viable approach to assuring sufficient hydrogen capacity at commercial fuelling stations. Presently, LH2 is produced at remote facilities and then transported to the end-use site by road vehicles (i.e., LH2 tanker trucks). Venting of hydrogen to depressurize the transport storage tank is a routine part of the LH2 delivery process. The behaviour of cold hydrogen plumes has not been well-characterized because empirical field data is essentially non-existent. The NFPA 2 Hydrogen Storage Safety Task Group, which consists of hydrogen producers, safety experts, and CFD modellers, has identified the lack of understanding of hydrogen dispersion during LH2 venting of storage vessel as a critical gap for establishing safety distances at LH2 facilities, especially commercial hydrogen fuelling stations. To address this need, the NREL sensor laboratory, in collaboration with the NFPA 2 Safety Task Group developed the Cold Hydrogen Plume Analyzer to empirically characterize the hydrogen plume formed during LH2 storage tank venting. A prototype Analyzer was developed and field-deployed at an actual LH2 venting operation with critical findings that included: - H2 being detected as much as 2 m lower than the release point, which is not predicted by existing models - A small and inconsistent correlation between oxygen depletion and the hydrogen concentration - A negligible to non-existent correlation between in-situ temperature and the hydrogen concentration The Analyzer is currently being upgraded for enhanced metrological capabilities including improved real-time spatial and temporal profiling of the plume and tracking of prevailing weather conditions. Additional deployments are planned to monitor plume behaviour under different wind, humidity, and temperatures. This data will be shared with the NFPA 2 Safety Task Group and ultimately will be used support theoretical models and code requirements prescribed in NFPA 2.

  10. High-resolution AFM topographs of Rubrivivax gelatinosus light-harvesting complex LH2

    Science.gov (United States)

    Scheuring, Simon; Reiss-Husson, Francoise; Engel, Andreas; Rigaud, Jean-Louis; Ranck, Jean-Luc

    2001-01-01

    Light-harvesting complexes 2 (LH2) are the accessory antenna proteins in the bacterial photosynthetic apparatus and are built up of αβ-heterodimers containing three bacteriochlorophylls and one carotenoid each. We have used atomic force microscopy (AFM) to investigate reconstituted LH2 from Rubrivivax gelatinosus, which has a C-terminal hydrophobic extension of 21 amino acids on the α-subunit. High-resolution topographs revealed a nonameric organization of the regularly packed cylindrical complexes incorporated into the membrane in both orientations. Native LH2 showed one surface which protruded by ∼6 Å and one that protruded by ∼14 Å from the membrane. Topographs of samples reconstituted with thermolysin-digested LH2 revealed a height reduction of the strongly protruding surface to ∼9 Å, and a change of its surface appearance. These results suggested that the α-subunit of R.gelatinosus comprises a single transmembrane helix and an extrinsic C-terminus, and allowed the periplasmic surface to be assigned. Occasionally, large rings (∼120 Å diameter) surrounded by LH2 rings were observed. Their diameter and appearance suggest the large rings to be LH1 complexes. PMID:11406579

  11. Gonadotropin determination in 24-h-urine by sensitive LH and FSH radioimmunoassays

    International Nuclear Information System (INIS)

    Raid, A.; Fenske, M.; Koenig, A.

    1979-01-01

    Urinary lutropin (LH) and follitropin (FSH) were precipitated with acetone and measured by specific radioimmunoassays. Recovery experiments with special regard to urinary pH values were done by adding 125 I-labelled LH and FSH to unprocessed urine. At pH 4.5 68.6% of LH and 66.1% of FSH were recovered. Increasing pH values up to 6.0 resulted in a significant recovery loss of 125 I-LH, but not of 125 I-FSH. Immunoreactive FSH concentrations decreased significantly 6 and 48 hours after starting storage at room temperature. In healthy males and females there were found mean LH and FSH concentrations in 24-h-urine which were similar to those reported by others: LH: males: 22.6 IU; cycling females: 17.8 IU; postmenopausal females: 49.1 IU; FSH: males 6.0 IU; cycling females: 15.0 IU; postmenopausal females: 48.5 IU. Because of their high sensitivity and practicability. These radioimmunoassays could be clinically useful approaches in assessment of pituitary and gonadal disorders in human subjects. (author)

  12. Inhibition of follicle-stimulating hormone-induced preovulatory follicles in rats treated with a nonsteroidal negative allosteric modulator of follicle-stimulating hormone receptor.

    Science.gov (United States)

    Dias, James A; Campo, Brice; Weaver, Barbara A; Watts, Julie; Kluetzman, Kerri; Thomas, Richard M; Bonnet, Béatrice; Mutel, Vincent; Poli, Sonia M

    2014-01-01

    We previously described a negative allosteric modulator (NAM) of FSHR (ADX61623) that blocked FSH-induced cAMP and progesterone production but did not block estradiol production. That FSHR NAM did not affect FSH-induced preovulatory follicle development as evidenced by the lack of an effect on the number of FSH-dependent oocytes found in the ampullae following ovulation with hCG. A goal is the development of a nonsteroidal contraceptive. Toward this end, a high-throughput screen using human FSHR identified an additional nonsteroidal small molecule (ADX68692). Although ADX68692 behaved like ADX61623 in inhibiting production of cAMP and progesterone, it also inhibited FSH-induced estradiol in an in vitro rat granulosa primary cell culture bioassay. When immature, noncycling female rats were injected subcutaneously or by oral dosing prior to exogenous FSH administration, it was found that ADX68692 decreased the number of oocytes recovered from the ampullae. The estrous cycles of mature female rats were disrupted by administration by oral gavage of 25 mg/kg and 10 mg/kg ADX68692. In the highest dose tested (25 mg/kg), 55% of animals cohabited with mature males had implantation sites compared to 33% in the 10 mg/kg group and 77% in the control group. A surprising finding was that a structural analog ADX68693, while effectively blocking progesterone production with similar efficacy as ADX68692, did not block estrogen production and despite better oral availability did not decrease the number of oocytes found in the ampullae even when used at 100 mg/kg. These data demonstrate that because of biased antagonism of the FSHR, nonsteroidal contraception requires that both arms of the FSHR steroidogenic pathway must be effectively blocked, particularly estrogen biosynthesis. Thus, a corollary to these findings is that it seems reasonable to propose that the estrogen-dependent diseases such as endometriosis may benefit from inhibition of FSH action at the ovary using the FSHR

  13. Objective measurement of postocclusion surge during phacoemulsification in human eye-bank eyes.

    Science.gov (United States)

    Georgescu, Dan; Payne, Marielle; Olson, Randall J

    2007-03-01

    To objectively compare the postocclusion vacuum surge among different phacoemulsification machines and devices. Experimental study. Infiniti, Legacy, Millennium, and Sovereign were tested in an eye-bank eye. All the machines were tested with 20-gauge non-ABS tips, 430 mm Hg vacuum pressure, 24 ml/minute aspiration rate, peristaltic pump, and 75 cm bottle height. In addition, Infiniti and Legacy were also tested with 20-gauge bypass tips (ABS), 125 cm bottle height, and 40 ml/minute flow rate. We also tested 19-gauge tips with Infiniti and Sovereign and the venturi pump for Millennium. Significant differences were found between all the machines tested with Millennium peristaltic generating the least and Millennium Venturi the most surge. ABS tips significantly decreased the surge for Legacy but not for Infiniti. Cruise Control (CC) had a significant effect on Sovereign but not on Millennium. Increasing the bottle height decreased surge while increasing the flow increased surge for both Infiniti and Legacy. The 19-gauge tips increased surge for both Infiniti and Sovereign. Surge varied over a range of 40 microm to more than 2 mm. ABS and CC decrease surge, especially when the machine is not functioning near the limits of surge prevention. Certain parameters, such as a 19-gauge tip and high flow, dramatically increased surge, whereas elevating the bottle ameliorates it. Understanding the impact of all these features will help in minimizing the problem.

  14. Risk assessment of storm surge disaster based on numerical models and remote sensing

    Science.gov (United States)

    Liu, Qingrong; Ruan, Chengqing; Zhong, Shan; Li, Jian; Yin, Zhonghui; Lian, Xihu

    2018-06-01

    Storm surge is one of the most serious ocean disasters in the world. Risk assessment of storm surge disaster for coastal areas has important implications for planning economic development and reducing disaster losses. Based on risk assessment theory, this paper uses coastal hydrological observations, a numerical storm surge model and multi-source remote sensing data, proposes methods for valuing hazard and vulnerability for storm surge and builds a storm surge risk assessment model. Storm surges in different recurrence periods are simulated in numerical models and the flooding areas and depth are calculated, which are used for assessing the hazard of storm surge; remote sensing data and GIS technology are used for extraction of coastal key objects and classification of coastal land use are identified, which is used for vulnerability assessment of storm surge disaster. The storm surge risk assessment model is applied for a typical coastal city, and the result shows the reliability and validity of the risk assessment model. The building and application of storm surge risk assessment model provides some basis reference for the city development plan and strengthens disaster prevention and mitigation.

  15. Differences in signal activation by LH and hCG are mediated by the LH/CG receptor`s extracellular hinge region

    Directory of Open Access Journals (Sweden)

    Paul eGrzesik

    2015-09-01

    Full Text Available The human lutropin/choriogonadotropin receptor (LHCGR can be activated by binding two slightly different gonadotropic glycoprotein hormones, choriogonadotropin (CG - secreted by the placenta, and lutropin (LH - produced by the pituitary. They induce different signaling profiles at the LHCGR. This cannot be explained by binding to the receptor's leucine-rich repeat domain (LRRD, as this binding is similar for the two hormones. We therefore speculate that there are previously unknown differences in the hormone/receptor interaction at the extracellular hinge region, which might help to understand functional differences between the two hormones. We have therefore performed a detailed study of the binding and action of LH and CG at the LHCGR hinge region. We focused on a primate-specific additional exon in the hinge region, which is located between LRRD and the serpentine domain. The segment of the hinge region encoded by exon10 was previously reported to be only relevant to hLH signaling, as the exon10-deletion receptor exhibits decreased hLH signaling, but unchanged hCG signaling. We designed an advanced homology model of the hormone/LHCGR complex, followed by experimental characterization of relevant fragments in the hinge region. In addition, we examined predictions of a helical exon10-encoded conformation by block-wise polyalanine (helix supporting mutations. These helix preserving modifications showed no effect on hormone induced signaling. However, introduction of a structure-disturbing double-proline mutant LHCGR-Q303P/E305P within the exon10-helix has, in contrast to exon10 deletion, no impact on hLH, but only on hCG signaling. This opposite effect on signaling by hLH and hCG can be explained by distinct sites of hormone interaction in the hinge region s. In conclusion, our analysis provides details of the differences between hLH- and hCG-induced signaling that are mainly determined in the L2-beta loop of the hormones and in the hinge region

  16. Hybrid vs Adaptive Ensemble Kalman Filtering for Storm Surge Forecasting

    Science.gov (United States)

    Altaf, M. U.; Raboudi, N.; Gharamti, M. E.; Dawson, C.; McCabe, M. F.; Hoteit, I.

    2014-12-01

    Recent storm surge events due to Hurricanes in the Gulf of Mexico have motivated the efforts to accurately forecast water levels. Toward this goal, a parallel architecture has been implemented based on a high resolution storm surge model, ADCIRC. However the accuracy of the model notably depends on the quality and the recentness of the input data (mainly winds and bathymetry), model parameters (e.g. wind and bottom drag coefficients), and the resolution of the model grid. Given all these uncertainties in the system, the challenge is to build an efficient prediction system capable of providing accurate forecasts enough ahead of time for the authorities to evacuate the areas at risk. We have developed an ensemble-based data assimilation system to frequently assimilate available data into the ADCIRC model in order to improve the accuracy of the model. In this contribution we study and analyze the performances of different ensemble Kalman filter methodologies for efficient short-range storm surge forecasting, the aim being to produce the most accurate forecasts at the lowest possible computing time. Using Hurricane Ike meteorological data to force the ADCIRC model over a domain including the Gulf of Mexico coastline, we implement and compare the forecasts of the standard EnKF, the hybrid EnKF and an adaptive EnKF. The last two schemes have been introduced as efficient tools for enhancing the behavior of the EnKF when implemented with small ensembles by exploiting information from a static background covariance matrix. Covariance inflation and localization are implemented in all these filters. Our results suggest that both the hybrid and the adaptive approach provide significantly better forecasts than those resulting from the standard EnKF, even when implemented with much smaller ensembles.

  17. Excitonic polarons in quasi-one-dimensional LH1 and LH2 bacteriochlorophyll a antenna aggregates from photosynthetic bacteria: A wavelength-dependent selective spectroscopy study

    International Nuclear Information System (INIS)

    Freiberg, Arvi; Raetsep, Margus; Timpmann, Kou; Trinkunas, Gediminas

    2009-01-01

    Spectral characteristics of the optically excited states in the ring-shaped quasi-one-dimensional aggregates comprising 18 and 32 tightly coupled bacteriochlorophyll a molecules have been investigated using selective spectroscopy methods and theoretical modelling of the data. Distinguished by the lowest electronic transition energies in the LH2 and LH1 antenna complexes these aggregates govern the functionally important ultrafast funneling of solar excitation energy in the photosynthetic membranes of purple bacteria. It was found by using a sophisticated differential fluorescence line narrowing method that exciton-phonon coupling in terms of the dimensionless Huang-Rhys factor is strong in these systems, justifying an excitonic polaron theoretical approach for the data analysis. Although we reached this qualitative conclusion already previously, in this work essential dependence of the exciton-phonon coupling strength and reorganization energy on excitation wavelength as well as on excitation light fluence has been established. We then show that these results corroborate with the properties of excitonic polarons in diagonally disordered ensembles of the aggregates. Furthermore, the weighted density of states of the phonon modes, which is an important characteristic of dynamical systems interacting with their surroundings, was derived. Its shape, being similar for all studied circular aggregates, deviates significantly from a reference profile describing local response of a protein to the Q y electronic transition in a single bacteriochlorophyll a molecule. Similarities of the data for regular and B800 deficient mutant LH2 complexes indicate that the B800 pigments have no direct influence on the electronic states of the B850 aggregate system. Consistent set of model parameters was determined, unambiguously implying that excitonic polarons, rather than bare excitons are proper lowest-energy optical excitations in the LH1 and LH2 antenna complexes

  18. Excitonic polarons in quasi-one-dimensional LH1 and LH2 bacteriochlorophyll a antenna aggregates from photosynthetic bacteria: A wavelength-dependent selective spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Freiberg, Arvi [Institute of Physics, University of Tartu, Riia 142, 51014 Tartu (Estonia); Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu (Estonia)], E-mail: arvi.freiberg@ut.ee; Raetsep, Margus; Timpmann, Kou [Institute of Physics, University of Tartu, Riia 142, 51014 Tartu (Estonia); Trinkunas, Gediminas [Insitute of Physics, Savanoriu pr. 231, LT-02300 Vilnius (Lithuania)

    2009-02-23

    Spectral characteristics of the optically excited states in the ring-shaped quasi-one-dimensional aggregates comprising 18 and 32 tightly coupled bacteriochlorophyll a molecules have been investigated using selective spectroscopy methods and theoretical modelling of the data. Distinguished by the lowest electronic transition energies in the LH2 and LH1 antenna complexes these aggregates govern the functionally important ultrafast funneling of solar excitation energy in the photosynthetic membranes of purple bacteria. It was found by using a sophisticated differential fluorescence line narrowing method that exciton-phonon coupling in terms of the dimensionless Huang-Rhys factor is strong in these systems, justifying an excitonic polaron theoretical approach for the data analysis. Although we reached this qualitative conclusion already previously, in this work essential dependence of the exciton-phonon coupling strength and reorganization energy on excitation wavelength as well as on excitation light fluence has been established. We then show that these results corroborate with the properties of excitonic polarons in diagonally disordered ensembles of the aggregates. Furthermore, the weighted density of states of the phonon modes, which is an important characteristic of dynamical systems interacting with their surroundings, was derived. Its shape, being similar for all studied circular aggregates, deviates significantly from a reference profile describing local response of a protein to the Q{sub y} electronic transition in a single bacteriochlorophyll a molecule. Similarities of the data for regular and B800 deficient mutant LH2 complexes indicate that the B800 pigments have no direct influence on the electronic states of the B850 aggregate system. Consistent set of model parameters was determined, unambiguously implying that excitonic polarons, rather than bare excitons are proper lowest-energy optical excitations in the LH1 and LH2 antenna complexes.

  19. High Resolution Hurricane Storm Surge and Inundation Modeling (Invited)

    Science.gov (United States)

    Luettich, R.; Westerink, J. J.

    2010-12-01

    Coastal counties are home to nearly 60% of the U.S. population and industry that accounts for over 16 million jobs and 10% of the U.S. annual gross domestic product. However, these areas are susceptible to some of the most destructive forces in nature, including tsunamis, floods, and severe storm-related hazards. Since 1900, tropical cyclones making landfall on the US Gulf of Mexico Coast have caused more than 9,000 deaths; nearly 2,000 deaths have occurred during the past half century. Tropical cyclone-related adjusted, annualized losses in the US have risen from 1.3 billion from 1949-1989, to 10.1 billion from 1990-1995, and $35.8 billion per year for the period 2001-2005. The risk associated with living and doing business in the coastal areas that are most susceptible to tropical cyclones is exacerbated by rising sea level and changes in the characteristics of severe storms associated with global climate change. In the five years since hurricane Katrina devastated the northern Gulf of Mexico Coast, considerable progress has been made in the development and utilization of high resolution coupled storm surge and wave models. Recent progress will be presented with the ADCIRC + SWAN storm surge and wave models. These tightly coupled models use a common unstructured grid in the horizontal that is capable of covering large areas while also providing high resolution (i.e., base resolution down to 20m plus smaller subgrid scale features such as sea walls and levees) in areas that are subject to surge and inundation. Hydrodynamic friction and overland winds are adjusted to account for local land cover. The models scale extremely well on modern high performance computers allowing rapid turnaround on large numbers of compute cores. The models have been adopted for FEMA National Flood Insurance Program studies, hurricane protection system design and risk analysis, and quasi-operational forecast systems for several regions of the country. They are also being evaluated as

  20. Coastal Flooding Hazards due to storm surges and subsidence

    DEFF Research Database (Denmark)

    Sørensen, Carlo; Knudsen, Per; Andersen, Ole B.

    Flooding hazard and risk mapping are major topics in low-lying coastal areas before even considering the adverse effects of sea level rise (SLR) due to climate change. While permanent inundation may be a prevalent issue, more often floods related to extreme events (storm surges) have the largest...... damage potential.Challenges are amplified in some areas due to subsidence from natural and/or anthropogenic causes. Subsidence of even a few mm/y may over time greatly impair the safety against flooding of coastal communities and must be accounted for in order to accomplish the economically most viable...

  1. Vulnerability of Coastal Communities from Storm Surge and Flood Disasters

    Science.gov (United States)

    Bathi, Jejal Reddy; Das, Himangshu S.

    2016-01-01

    Disasters in the form of coastal storms and hurricanes can be very destructive. Preparing for anticipated effects of such disasters can help reduce the public health and economic burden. Identifying vulnerable population groups can help prioritize resources for the most needed communities. This paper presents a quantitative framework for vulnerability measurement that incorporates both socioeconomic and flood inundation vulnerability. The approach is demonstrated for three coastal communities in Mississippi with census tracts being the study unit. The vulnerability results are illustrated as thematic maps for easy usage by planners and emergency responders to assist in prioritizing their actions to vulnerable populations during storm surge and flood disasters. PMID:26907313

  2. The organization of LH2 complexes in membranes from Rhodobacter sphaeroides.

    Science.gov (United States)

    Olsen, John D; Tucker, Jaimey D; Timney, John A; Qian, Pu; Vassilev, Cvetelin; Hunter, C Neil

    2008-11-07

    The mapping of the photosynthetic membrane of Rhodobacter sphaeroides by atomic force microscopy (AFM) revealed a unique organization of arrays of dimeric reaction center-light harvesting I-PufX (RC-LH1-PufX) core complexes surrounded and interconnected by light-harvesting LH2 complexes (Bahatyrova, S., Frese, R. N., Siebert, C. A., Olsen, J. D., van der Werf, K. O., van Grondelle, R., Niederman, R. A., Bullough, P. A., Otto, C., and Hunter, C. N. (2004) Nature 430, 1058-1062). However, membrane regions consisting solely of LH2 complexes were under-represented in these images because these small, highly curved areas of membrane rendered them difficult to image even using gentle tapping mode AFM and impossible with contact mode AFM. We report AFM imaging of membranes prepared from a mutant of R. sphaeroides, DPF2G, that synthesizes only the LH2 complexes, which assembles spherical intracytoplasmic membrane vesicles of approximately 53 nm diameter in vivo. By opening these vesicles and adsorbing them onto mica to form small, LH2-only membranes for the first time. The transition from highly curved vesicle to the planar sheet is accompanied by a change in the packing of the LH2 complexes such that approximately half of the complexes are raised off the mica surface by approximately 1 nm relative to the rest. This vertical displacement produces a very regular corrugated appearance of the planar membrane sheets. Analysis of the topographs was used to measure the distances and angles between the complexes. These data are used to model the organization of LH2 complexes in the original, curved membrane. The implications of this architecture for the light harvesting function and diffusion of quinones in native membranes of R. sphaeroides are discussed.

  3. Multidecadal Scale Detection Time for Potentially Increasing Atlantic Storm Surges in a Warming Climate

    Science.gov (United States)

    Lee, Benjamin Seiyon; Haran, Murali; Keller, Klaus

    2017-10-01

    Storm surges are key drivers of coastal flooding, which generate considerable risks. Strategies to manage these risks can hinge on the ability to (i) project the return periods of extreme storm surges and (ii) detect potential changes in their statistical properties. There are several lines of evidence linking rising global average temperatures and increasingly frequent extreme storm surges. This conclusion is, however, subject to considerable structural uncertainty. This leads to two main questions: What are projections under various plausible statistical models? How long would it take to distinguish among these plausible statistical models? We address these questions by analyzing observed and simulated storm surge data. We find that (1) there is a positive correlation between global mean temperature rise and increasing frequencies of extreme storm surges; (2) there is considerable uncertainty underlying the strength of this relationship; and (3) if the frequency of storm surges is increasing, this increase can be detected within a multidecadal timescale (≈20 years from now).

  4. The Use of a Statistical Model of Storm Surge as a Bias Correction for Dynamical Surge Models and its Applicability along the U.S. East Coast

    Directory of Open Access Journals (Sweden)

    Haydee Salmun

    2015-02-01

    Full Text Available The present study extends the applicability of a statistical model for prediction of storm surge originally developed for The Battery, NY in two ways: I. the statistical model is used as a biascorrection for operationally produced dynamical surge forecasts, and II. the statistical model is applied to the region of the east coast of the U.S. susceptible to winter extratropical storms. The statistical prediction is based on a regression relation between the “storm maximum” storm surge and the storm composite significant wave height predicted ata nearby location. The use of the statistical surge prediction as an alternative bias correction for the National Oceanic and Atmospheric Administration (NOAA operational storm surge forecasts is shownhere to be statistically equivalent to the existing bias correctiontechnique and potentially applicable for much longer forecast lead times as well as for storm surge climate prediction. Applying the statistical model to locations along the east coast shows that the regression relation can be “trained” with data from tide gauge measurements and near-shore buoys along the coast from North Carolina to Maine, and that it provides accurate estimates of storm surge.

  5. Tide-surge interaction along the east coast of the Leizhou Peninsula, South China Sea

    Science.gov (United States)

    Zhang, Heng; Cheng, Weicong; Qiu, Xixi; Feng, Xiangbo; Gong, Wenping

    2017-06-01

    A triply-nested two-dimensional (2D) ocean circulation model along with observed sea level records are used to study tide-surge interaction along the east coast of the Leizhou Peninsula (LP) which is characterized by extensive mudflats, large tidal ranges and a complex coastline. The dependency of surge maxima on the water level and the phase of tide are respectively investigated using two statistical approaches. Results show that tide-surge interaction along the east coast of the LP is significant, where surges peak 3-6 h before or after the nearest high water. The triply-nested 2D ocean circulation model is used to quantify tide-surge interaction in this region and to investigate its physical cause. The largest amplitudes of tide-surge interaction are found in the shallow water region of the Leizhou Bay, with values up to 1 m during typhoon events. Numerical experiments reveal that nonlinear bottom friction is the main contributor to tide-surge interaction, while the contribution of the nonlinear advective effect can be neglected. The shallow water effect enhances the role of nonlinear bottom friction in determining tide-surge modulation, leaving the surge peaks usually occur on the rising or falling tide. It is also found that the relative contribution of local wind and remote wind is different depending on the storm track and storm intensity, which would finally affect the temporal and spatial distribution of tide-surge interaction during typhoon events. These findings confirm the importance of coupling storm surges and tides for the prediction of storm surge events in regions which are characterized by shallow water depths and large tidal ranges.

  6. Characteristics and possibilities of software tool for metal-oxide surge arresters selection

    Directory of Open Access Journals (Sweden)

    Đorđević Dragan

    2012-01-01

    Full Text Available This paper presents a procedure for the selection of metal-oxide surge arresters based on the instructions given in the Siemens and ABB catalogues, respecting their differences and the characteristics and possibilities of the software tool. The software tool was developed during the preparation of a Master's thesis titled, 'Automation of Metal-Oxide Surge Arresters Selection'. An example is presented of the selection of metal-oxide surge arresters using the developed software tool.

  7. Mapping and Visualization of Storm-Surge Dynamics for Hurricane Katrina and Hurricane Rita

    Science.gov (United States)

    Gesch, Dean B.

    2009-01-01

    The damages caused by the storm surges from Hurricane Katrina and Hurricane Rita were significant and occurred over broad areas. Storm-surge maps are among the most useful geospatial datasets for hurricane recovery, impact assessments, and mitigation planning for future storms. Surveyed high-water marks were used to generate a maximum storm-surge surface for Hurricane Katrina extending from eastern Louisiana to Mobile Bay, Alabama. The interpolated surface was intersected with high-resolution lidar elevation data covering the study area to produce a highly detailed digital storm-surge inundation map. The storm-surge dataset and related data are available for display and query in a Web-based viewer application. A unique water-level dataset from a network of portable pressure sensors deployed in the days just prior to Hurricane Rita's landfall captured the hurricane's storm surge. The recorded sensor data provided water-level measurements with a very high temporal resolution at surveyed point locations. The resulting dataset was used to generate a time series of storm-surge surfaces that documents the surge dynamics in a new, spatially explicit way. The temporal information contained in the multiple storm-surge surfaces can be visualized in a number of ways to portray how the surge interacted with and was affected by land surface features. Spatially explicit storm-surge products can be useful for a variety of hurricane impact assessments, especially studies of wetland and land changes where knowledge of the extent and magnitude of storm-surge flooding is critical.

  8. A Comparison of Ensemble Kalman Filters for Storm Surge Assimilation

    KAUST Repository

    Altaf, Muhammad

    2014-08-01

    This study evaluates and compares the performances of several variants of the popular ensembleKalman filter for the assimilation of storm surge data with the advanced circulation (ADCIRC) model. Using meteorological data from Hurricane Ike to force the ADCIRC model on a domain including the Gulf ofMexico coastline, the authors implement and compare the standard stochastic ensembleKalman filter (EnKF) and three deterministic square root EnKFs: the singular evolutive interpolated Kalman (SEIK) filter, the ensemble transform Kalman filter (ETKF), and the ensemble adjustment Kalman filter (EAKF). Covariance inflation and localization are implemented in all of these filters. The results from twin experiments suggest that the square root ensemble filters could lead to very comparable performances with appropriate tuning of inflation and localization, suggesting that practical implementation details are at least as important as the choice of the square root ensemble filter itself. These filters also perform reasonably well with a relatively small ensemble size, whereas the stochastic EnKF requires larger ensemble sizes to provide similar accuracy for forecasts of storm surge.

  9. A Comparison of Ensemble Kalman Filters for Storm Surge Assimilation

    KAUST Repository

    Altaf, Muhammad; Butler, T.; Mayo, T.; Luo, X.; Dawson, C.; Heemink, A. W.; Hoteit, Ibrahim

    2014-01-01

    This study evaluates and compares the performances of several variants of the popular ensembleKalman filter for the assimilation of storm surge data with the advanced circulation (ADCIRC) model. Using meteorological data from Hurricane Ike to force the ADCIRC model on a domain including the Gulf ofMexico coastline, the authors implement and compare the standard stochastic ensembleKalman filter (EnKF) and three deterministic square root EnKFs: the singular evolutive interpolated Kalman (SEIK) filter, the ensemble transform Kalman filter (ETKF), and the ensemble adjustment Kalman filter (EAKF). Covariance inflation and localization are implemented in all of these filters. The results from twin experiments suggest that the square root ensemble filters could lead to very comparable performances with appropriate tuning of inflation and localization, suggesting that practical implementation details are at least as important as the choice of the square root ensemble filter itself. These filters also perform reasonably well with a relatively small ensemble size, whereas the stochastic EnKF requires larger ensemble sizes to provide similar accuracy for forecasts of storm surge.

  10. New technology and tool prepared for communication against storm surges.

    Science.gov (United States)

    Letkiewicz, Beata

    2010-05-01

    The aim of the presentation is description of the new technology and tool prepared for communication, information and issue of warnings against storm surges. The Maritime Branch of the Institute of Meteorology and Water Management is responsible for preparing the forecast as warning, where the end users are Government Officials and Public. The Maritime Branch carry out the project "Strengthening the administrative capacity in order to improve the management of Polish coastal zone environment" (supported by a grant from Norway through the Norwegian Financial Mechanism). The expected final result of the project is web site www.baltyk.pogodynka.pl. One of the activities of the project is - set up of information website www.baltyk.pogodynka.pl, giving public access to the complied data. Information on web site: - meta data - marine data (on-line measurement: sea level, water temperature, salinity, oxygen concentration); - data bases of mathematical model outputs - forecast data (sea level, currents); - ice conditions of the Baltic Sea, - instructions, information materials with information of polish coastal zone. The aim of set up of the portal is development of communication between users of the system, exchange of the knowledge of marine environment and natural hazards such as storm surges, improving the ability of the region in the scope of the data management about the sea environment and the coastal zone.

  11. SURGTANK, Steam Pressure, Saturation Temperature or Reactor Surge Tank

    International Nuclear Information System (INIS)

    Gorman, D.J.; Gupta, R.K.

    2001-01-01

    1 - Description of problem or function: SURGTANK generates the steam pressure, saturation temperature, and ambient temperature history for a nuclear reactor steam surge tank (pressurizer) in a state of thermodynamic equilibrium subjected to a liquid insurge described by a specified time history of liquid levels. It is capable also of providing the pressure and saturation temperature history, starting from thermodynamic equilibrium conditions, for the same tank subjected to an out-surge described by a time history of liquid levels. Both operations are available for light- or heavy- water nuclear reactor systems. The tank is assumed to have perfect thermal insulation on its outer wall surfaces. 2 - Method of solution: Surge tank geometry and initial liquid level and saturation pressure are provided as input for the out-surge problem, along with the prescribed time-sequence level history. SURGTANK assumes a reduced pressure for the end of the first change in liquid level and determines the associated change of entropy for the closed system. The assumed pressure is adjusted and the associated change in entropy recalculated until a pressure is attained for which no change occurs. This pressure is recorded and used as the beginning pressure for the next level increment. The system is then re-defined to exclude the small amount of liquid which has left the tank, and a solution for the pressure at the end of the second level increment is obtained. The procedure is terminated when the pressure at the end of the final increment has been determined. Surge tank geometry, thermal conductivity, specific heat, and density of tank walls, initial liquid level, and saturation pressure are provided as input for the insurge problem, along with the prescribed time-sequence level history. SURGTANK assumes a slightly in- creased pressure for the end of the first level, the inner tank sur- face is assumed to follow saturation temperature, linearly with time, throughout the interval, and

  12. Impact of the lipid bilayer on energy transfer kinetics in the photosynthetic protein LH2.

    Science.gov (United States)

    Ogren, John I; Tong, Ashley L; Gordon, Samuel C; Chenu, Aurélia; Lu, Yue; Blankenship, Robert E; Cao, Jianshu; Schlau-Cohen, Gabriela S

    2018-03-28

    Photosynthetic purple bacteria convert solar energy to chemical energy with near unity quantum efficiency. The light-harvesting process begins with absorption of solar energy by an antenna protein called Light-Harvesting Complex 2 (LH2). Energy is subsequently transferred within LH2 and then through a network of additional light-harvesting proteins to a central location, termed the reaction center, where charge separation occurs. The energy transfer dynamics of LH2 are highly sensitive to intermolecular distances and relative organizations. As a result, minor structural perturbations can cause significant changes in these dynamics. Previous experiments have primarily been performed in two ways. One uses non-native samples where LH2 is solubilized in detergent, which can alter protein structure. The other uses complex membranes that contain multiple proteins within a large lipid area, which make it difficult to identify and distinguish perturbations caused by protein-protein interactions and lipid-protein interactions. Here, we introduce the use of the biochemical platform of model membrane discs to study the energy transfer dynamics of photosynthetic light-harvesting complexes in a near-native environment. We incorporate a single LH2 from Rhodobacter sphaeroides into membrane discs that provide a spectroscopically amenable sample in an environment more physiological than detergent but less complex than traditional membranes. This provides a simplified system to understand an individual protein and how the lipid-protein interaction affects energy transfer dynamics. We compare the energy transfer rates of detergent-solubilized LH2 with those of LH2 in membrane discs using transient absorption spectroscopy and transient absorption anisotropy. For one key energy transfer step in LH2, we observe a 30% enhancement of the rate for LH2 in membrane discs compared to that in detergent. Based on experimental results and theoretical modeling, we attribute this difference to

  13. Evaluation of Loss Due to Storm Surge Disasters in China Based on Econometric Model Groups

    Science.gov (United States)

    Shi, Xiaoxia; Xu, Tongbin; Yin, Kedong

    2018-01-01

    Storm surge has become an important factor restricting the economic and social development of China’s coastal regions. In order to improve the scientific judgment of future storm surge damage, a method of model groups is proposed to refine the evaluation of the loss due to storm surges. Due to the relative dispersion and poor regularity of the natural property data (login center air pressure, maximum wind speed, maximum storm water, super warning water level, etc.), storm surge disaster is divided based on eight kinds of storm surge disaster grade division methods combined with storm surge water, hypervigilance tide level, and disaster loss. The storm surge disaster loss measurement model groups consist of eight equations, and six major modules are constructed: storm surge disaster in agricultural loss, fishery loss, human resource loss, engineering facility loss, living facility loss, and direct economic loss. Finally, the support vector machine (SVM) model is used to evaluate the loss and the intra-sample prediction. It is indicated that the equations of the model groups can reflect in detail the relationship between the damage of storm surges and other related variables. Based on a comparison of the original value and the predicted value error, the model groups pass the test, providing scientific support and a decision basis for the early layout of disaster prevention and mitigation. PMID:29584628

  14. Evaluation of Loss Due to Storm Surge Disasters in China Based on Econometric Model Groups.

    Science.gov (United States)

    Jin, Xue; Shi, Xiaoxia; Gao, Jintian; Xu, Tongbin; Yin, Kedong

    2018-03-27

    Storm surge has become an important factor restricting the economic and social development of China's coastal regions. In order to improve the scientific judgment of future storm surge damage, a method of model groups is proposed to refine the evaluation of the loss due to storm surges. Due to the relative dispersion and poor regularity of the natural property data (login center air pressure, maximum wind speed, maximum storm water, super warning water level, etc.), storm surge disaster is divided based on eight kinds of storm surge disaster grade division methods combined with storm surge water, hypervigilance tide level, and disaster loss. The storm surge disaster loss measurement model groups consist of eight equations, and six major modules are constructed: storm surge disaster in agricultural loss, fishery loss, human resource loss, engineering facility loss, living facility loss, and direct economic loss. Finally, the support vector machine (SVM) model is used to evaluate the loss and the intra-sample prediction. It is indicated that the equations of the model groups can reflect in detail the relationship between the damage of storm surges and other related variables. Based on a comparison of the original value and the predicted value error, the model groups pass the test, providing scientific support and a decision basis for the early layout of disaster prevention and mitigation.

  15. Using Satellite Altimetry to Calibrate the Simulation of Typhoon Seth Storm Surge off Southeast China

    Directory of Open Access Journals (Sweden)

    Xiaohui Li

    2018-04-01

    Full Text Available Satellite altimeters can capture storm surges generated by typhoons and tropical storms, if the satellite flies over at the right time. In this study, we show TOPEX/Poseidon altimeter-observed storm surge features off Southeast China on 10 October 1994 during Typhoon Seth. We then use a three-dimensional, barotropic, finite-volume community ocean model (FVCOM to simulate storm surges. An innovative aspect is that satellite data are used to calibrate the storm surge model to improve model performance, by adjusting model wind forcing fields (the National Center for Environment Prediction (NCEP reanalysis product in reference to the typhoon best-track data. The calibration reduces the along-track root-mean-square (RMS difference between model and altimetric data from 0.15 to 0.10 m. It also reduces the RMS temporal difference from 0.21 to 0.18 m between the model results and independent tide-gauge data at Xiamen. In particular, the calibrated model produces a peak storm surge of 1.01 m at 6:00 10 October 1994 at Xiamen, agreeing with tide-gauge data; while the peak storm surge with the NCEP forcing is 0.71 m only. We further show that the interaction between storm surges and astronomical tides contributes to the peak storm surge by 34% and that the storm surge propagates southwestward as a coastally-trapped Kelvin wave.

  16. Evaluation of Loss Due to Storm Surge Disasters in China Based on Econometric Model Groups

    Directory of Open Access Journals (Sweden)

    Xue Jin

    2018-03-01

    Full Text Available Storm surge has become an important factor restricting the economic and social development of China’s coastal regions. In order to improve the scientific judgment of future storm surge damage, a method of model groups is proposed to refine the evaluation of the loss due to storm surges. Due to the relative dispersion and poor regularity of the natural property data (login center air pressure, maximum wind speed, maximum storm water, super warning water level, etc., storm surge disaster is divided based on eight kinds of storm surge disaster grade division methods combined with storm surge water, hypervigilance tide level, and disaster loss. The storm surge disaster loss measurement model groups consist of eight equations, and six major modules are constructed: storm surge disaster in agricultural loss, fishery loss, human resource loss, engineering facility loss, living facility loss, and direct economic loss. Finally, the support vector machine (SVM model is used to evaluate the loss and the intra-sample prediction. It is indicated that the equations of the model groups can reflect in detail the relationship between the damage of storm surges and other related variables. Based on a comparison of the original value and the predicted value error, the model groups pass the test, providing scientific support and a decision basis for the early layout of disaster prevention and mitigation.

  17. Vulnerability assessment of storm surges in the coastal area of Guangdong Province

    Directory of Open Access Journals (Sweden)

    K. Li

    2011-07-01

    Full Text Available Being bordered by the South China Sea and with long coastline, the coastal zone of Guangdong Province is often under severe risk of storm surges, as one of a few regions in China which is seriously threatened by storm surges. This article systematically analyzes the vulnerability factors of storm surges in the coastal area of Guangdong (from Yangjing to Shanwei. Five vulnerability assessment indicators of hazard-bearing bodies are proposed, which are social economic index, land use index, eco-environmental index, coastal construction index, and disaster-bearing capability index. Then storm surge vulnerability assessment index system in the coastal area of Guangdong is established. Additionally, the international general mode about coastal vulnerability assessment is improved, and the vulnerability evolution model of storm surges in the coastal area of Guangdong is constructed. Using ArcGIS, the vulnerability zoning map of storm surges in the study region is drawn. Results show that there is the highest degree of storm surge vulnerability in Zhuhai, Panyu, and Taishan; second in Zhongshan, Dongguan, Huiyang, and Haifeng; third in Jiangmen, Shanwei, Yangjiang, and Yangdong; fourth in Baoan, Kaiping, and Enping; and lowest in Guangzhou, Shunde, Shenzhen, and Longgang. This study on the risk of storm surges in these coastal cities can guide the land use of coastal cities in the future, and provide scientific advice for the government to prevent and mitigate the storm surge disasters. It has important theoretical and practical significance.

  18. Structure design of water discharge surge tank of nuclear power plant

    International Nuclear Information System (INIS)

    Wang Fang; Hou Shuqiang

    2015-01-01

    Drainage is an important function of water discharge surge tank in nuclear power plant. There is little wall and beam inside the water discharge surge tank due to the requirement of major work, which is different from the general structure. Taking water discharge surge tank of nuclear power plant for example, concerned problems are expatiated in the structure scheme of water discharge surge tank, and important structural components are analyzed. Structural analysis model is established by ANSYS finite element analysis. A comprehensive and numerical analysis is performed for different combinations of structural model, and the internal force of structure is extracted. Finally, suggestions for design of similar structure are proposed. (authors)

  19. The Development of Storm Surge Ensemble Prediction System and Case Study of Typhoon Meranti in 2016

    Science.gov (United States)

    Tsai, Y. L.; Wu, T. R.; Terng, C. T.; Chu, C. H.

    2017-12-01

    Taiwan is under the threat of storm surge and associated inundation, which is located at a potentially severe storm generation zone. The use of ensemble prediction can help forecasters to know the characteristic of storm surge under the uncertainty of track and intensity. In addition, it can help the deterministic forecasting. In this study, the kernel of ensemble prediction system is based on COMCOT-SURGE (COrnell Multi-grid COupled Tsunami Model - Storm Surge). COMCOT-SURGE solves nonlinear shallow water equations in Open Ocean and coastal regions with the nested-grid scheme and adopts wet-dry-cell treatment to calculate potential inundation area. In order to consider tide-surge interaction, the global TPXO 7.1 tide model provides the tidal boundary conditions. After a series of validations and case studies, COMCOT-SURGE has become an official operating system of Central Weather Bureau (CWB) in Taiwan. In this study, the strongest typhoon in 2016, Typhoon Meranti, is chosen as a case study. We adopt twenty ensemble members from CWB WRF Ensemble Prediction System (CWB WEPS), which differs from parameters of microphysics, boundary layer, cumulus, and surface. From box-and-whisker results, maximum observed storm surges were located in the interval of the first and third quartile at more than 70 % gauge locations, e.g. Toucheng, Chengkung, and Jiangjyun. In conclusion, the ensemble prediction can effectively help forecasters to predict storm surge especially under the uncertainty of storm track and intensity

  20. Surge protective device response to steep front transient in low voltage circuit

    Energy Technology Data Exchange (ETDEWEB)

    Marcuz, J.; Binczak, S.; Bilbault, J.M. [Universite de Bourgogne, Dijon (France)], Emails: jerome.marcuz@ laposte.net, stbinc@u-bourgogne.fr, bilbault@u-bourgogne.fr; Girard, F. [ADEE Electronic, Pont de Pany (France)

    2007-07-01

    Surge propagation on cables of electrical or data lines leads to a major protection problem as the number of equipment based on solid-state circuits or microprocessors increases. Sub-microsecond components of real surge waveform has to be taken into account for a proper protection even in the case of surges caused by indirect lightning effects. The response of a model of transient voltage suppressor diode based surge protection device (SPD) to fast front transient is analytically studied, then compared to simulations, including the lines connected to the SPD and to the protected equipment. (author)

  1. Effects of recombinant LH treatment on folliculogenesis and responsiveness to FSH stimulation

    DEFF Research Database (Denmark)

    Durnerin, Cedrin I; Erb, K; Fleming, R

    2008-01-01

    at the start of r-hLH treatment, on FSH stimulation Days 0 and 8 and at the time of HCG administration. RESULTS: The LH treatment was associated with increased small antral follicles prior to FSH stimulation (P = 0.007), and an increased yield of normally fertilized (2 PN) embryos (P = 0...... in a clinical setting by employing a sequential approach to stimulation by recombinant human (r-h) LH followed by r-hFSH in women who were profoundly down-regulated by depo GnRH agonist. METHODS: We employed a multi-centre, prospective, randomized approach. Women (n = 146) were treated in a long course high......-dose GnRH agonist (Decapeptyl, 4.2 mg s.c.) protocol and were randomized to receive r-hLH (Luveris, 300 IU/day) for a fixed 7 days, or no r-hLH treatment. This was followed by a standard r-hFSH stimulation regime (Gonal-F, 150 IU/day). Ultrasound and hormone assessments of responses were measured...

  2. LH prevents cisplatin-induced apoptosis in oocytes and preserves female fertility in mouse.

    Science.gov (United States)

    Rossi, Valerio; Lispi, Monica; Longobardi, Salvatore; Mattei, Maurizio; Rella, Francesca Di; Salustri, Antonietta; De Felici, Massimo; Klinger, Francesca G

    2017-01-01

    Premature ovarian failure and female infertility are frequent side effects of anticancer therapies, owing to the extreme sensitivity of the ovarian reserve oocytes to the damaging effects of irradiation and chemotherapy on DNA. We report here a robust protective effect of luteinizing hormone (LH) on the primordial follicle pool of prepubertal ovaries against the cisplatin (Cs)-induced apoptosis. In vitro LH treatment of prepubertal ovarian fragments generated anti-apoptotic signals by a subset of ovarian somatic cells expressing LH receptor (LHR) through cAMP/PKA and Akt pathways. Such signals, reducing the oocyte level of pro-apoptotic TAp63 protein and favoring the repair of the Cs-damaged DNA in the oocytes, prevented their apoptosis. Noteworthy, in vivo administration to prepubertal female mice of a single dose of LH together with Cs inhibited the depletion of the primordial follicle reserve caused by the drug and preserved their fertility in reproductive age, preventing significant alteration in the number of pregnancy and of delivered pups. In conclusion, these findings establish a novel ovoprotective role for LH and further support the very attracting prospective to use physiological 'fertoprotective' approaches for preventing premature infertility and risks linked to precocious menopause in young patients who survived cancer after chemotherapy.

  3. LH Dynamics in Overweight Girls with Premature Adrenarche and Slowly Progressive Sexual Precocity

    Directory of Open Access Journals (Sweden)

    Rosenfield RobertL

    2010-08-01

    Full Text Available Background. Excess adiposity and premature adrenarche (PA are risk factors for the development of polycystic ovary syndrome (PCOS. Methods. Girls with slowly progressive precocious breast development, who were overweight and had PA (SPPOPA, 6.2–8.2 years, , overweight PA (6.6–10.8 years, , and overweight premenarcheal controls (OW-PUB, 10.6–12.8 years, underwent hormonal sleep testing and GnRH agonist (GnRHag and ACTH tests. Results. Despite an insignificant sleep-related increase in LH and prepubertal baseline hormone levels, SPPOPA peak LH and estradiol responses to GnRHag were intermediate between those of PA and OW-PUB, the LH being significantly different from both. Conclusions. GnRHag tests indicate that SPPOPA is a slowly progressive form of true puberty with blunted LH dynamics. These results argue against the prepubertal hyperandrogenism of excess adiposity or PA enhancing LH secretion or causing ovarian hyperandrogenism prior to menarche. Excess adiposity may contribute to both the early onset and slow progression of puberty.

  4. LHRH and LH in peripubertal female rats following prenatal and/or postnatal ethanol exposure

    International Nuclear Information System (INIS)

    Morris, D.L.; Harms, P.G.; Petersen, H.D.; McArthur, N.H.

    1989-01-01

    The effects of pre- and postnatal exposure to ethanol (ETHO) on LHRH and LH were investigated. Pregnant and/or lactating dams were fed ETHOD during: (1) gestation, (2) lactation, or (3) gestation-lactation. Female offspring were decapitated at 30 or 40 days-of-age; trunk blood was collected for plasma LH RIA; and hypothalamic tissues were collected for LHRH RIA. Hypothalamic LHRH content of all ETOH-exposed groups was less than that of non-ETOH-fed controls at 30 and 40 days-of-age. Plasma LH concentrations of all ETOH-exposed groups were less than those of non-ETOD-fed controls at 30 and 40 days-of-age. Also, at 30 and 40 days-of-age, the plasma LH concentrations of the animals exposed to ETOH during lactation and gestation-lactation were less than those of the animals exposed to ETOH during gestation. These data suggest that ETOH exposure during gestation and/or lactation negatively affects hypothalamic LHRH content of femal rat offspring. Decreased hypothalamic LHRH content with corresponding lowered plasma LH concentration suggests that ETOH influences development or maturation of hypothalamic LHRH neurons by possibly decreasing their number or synthesizing capability

  5. LH prevents cisplatin-induced apoptosis in oocytes and preserves female fertility in mouse

    Science.gov (United States)

    Rossi, Valerio; Lispi, Monica; Longobardi, Salvatore; Mattei, Maurizio; Rella, Francesca Di; Salustri, Antonietta; De Felici, Massimo; Klinger, Francesca G

    2017-01-01

    Premature ovarian failure and female infertility are frequent side effects of anticancer therapies, owing to the extreme sensitivity of the ovarian reserve oocytes to the damaging effects of irradiation and chemotherapy on DNA. We report here a robust protective effect of luteinizing hormone (LH) on the primordial follicle pool of prepubertal ovaries against the cisplatin (Cs)-induced apoptosis. In vitro LH treatment of prepubertal ovarian fragments generated anti-apoptotic signals by a subset of ovarian somatic cells expressing LH receptor (LHR) through cAMP/PKA and Akt pathways. Such signals, reducing the oocyte level of pro-apoptotic TAp63 protein and favoring the repair of the Cs-damaged DNA in the oocytes, prevented their apoptosis. Noteworthy, in vivo administration to prepubertal female mice of a single dose of LH together with Cs inhibited the depletion of the primordial follicle reserve caused by the drug and preserved their fertility in reproductive age, preventing significant alteration in the number of pregnancy and of delivered pups. In conclusion, these findings establish a novel ovoprotective role for LH and further support the very attracting prospective to use physiological 'fertoprotective' approaches for preventing premature infertility and risks linked to precocious menopause in young patients who survived cancer after chemotherapy. PMID:27689876

  6. Plasma biasing by fast particles generation in front of CASTOR and TORE SUPRA tokamak LH grills

    International Nuclear Information System (INIS)

    Petrzilka, V.; Jakubka, K.; Klima, R.

    1999-01-01

    Computation results are presented concerning the electron acceleration by the LH wave alone, which are necessary for determining the value of the effective ponderomotive potential W. One set of selected parameters is representative for large tokamaks like Tore Supra and JET; the other set is representative for the small CASTOR tokamak. To estimate the value of W, the test-particle model was used for describing the electron acceleration. Then, by using the two-fluid model, profiles of U and Ε z are presented. Further, by using the corresponding value of W in the Particle-in-Cell model for the simulations of the plasma vortex in front of the LH grill, the effects are explored of the electrostatic fields Ε r , Ε θ and Ε z , on the following processes: 1. particle acceleration in front of LH grills by rf waves - it is demonstrated that in addition to electron acceleration, the charge-separation electrostatic field Ε z also accelerates ions to energies of several keV; 2. effects of plasma sources on the flow of particles from the narrow layer in front of the LH grill mouth - here it is shown that ionization alone is not sufficient for creating the experimentally observed plasma densities in front of LH grills

  7. Protein structural deformation induced lifetime shortening of photosynthetic bacteria light-harvesting complex LH2 excited state.

    Science.gov (United States)

    Chen, Xing-Hai; Zhang, Lei; Weng, Yu-Xiang; Du, Lu-Chao; Ye, Man-Ping; Yang, Guo-Zhen; Fujii, Ritsuko; Rondonuwu, Ferdy S; Koyama, Yasushi; Wu, Yi-Shi; Zhang, J P

    2005-06-01

    Photosynthetic bacterial light-harvesting antenna complex LH2 was immobilized on the surface of TiO(2) nanoparticles in the colloidal solution. The LH2/TiO(2) assembly was investigated by the time-resolved spectroscopic methods. The excited-state lifetimes for carotenoid-containing and carotenoidless LH2 have been measured, showing a decrease in the excited-state lifetime of B850 when LH2 was immobilized on TiO(2). The possibility that the decrease of the LH2 excited-state lifetime being caused by an interfacial electron transfer reaction between B850 and the TiO(2) nanoparticle was precluded experimentally. We proposed that the observed change in the photophysical properties of LH2 when assembled onto TiO(2) nanoparticles is arising from the interfacial-interaction-induced structural deformation of the LH2 complex deviating from an ellipse of less eccentric to a more eccentric ellipse, and the observed phenomenon can be accounted by an elliptical exciton model. Experiment by using photoinactive SiO(2) nanoparticle in place of TiO(2) and core complex LH1 instead of LH2 provide further evidence to the proposed mechanism.

  8. Effect of gas injection during LH wave coupling at ITER-relevant plasma-wall distances in JET

    International Nuclear Information System (INIS)

    Ekedahl, A; Goniche, M; Basiuk, V; Delpech, L; Imbeaux, F; Joffrin, E; Loarer, T; Rantamaeki, K; Mailloux, J; Alper, B; Baranov, Y; Beaumont, P; Corrigan, G; Erents, K; Hawkes, N; McDonald, D; Petrzilka, V; Granucci, G; Hobirk, J; Kirov, K

    2009-01-01

    Good coupling of lower hybrid (LH) waves has been demonstrated in different H-mode scenarios in JET, at high triangularity (δ ∼ 0.4) and at large distance between the last closed flux surface and the LH launcher (up to 15 cm). Local gas injection of D 2 in the region magnetically connected to the LH launcher is used for increasing the local density in the scrape-off layer (SOL). Reciprocating Langmuir probe measurements magnetically connected to the LH launcher indicate that the electron density profile flattens in the far SOL during gas injection and LH power application. Some degradation in normalized H-mode confinement, as given by the H98(y,2)-factor, could be observed at high gas injection rates in these scenarios, but this was rather due to total gas injection and not specifically to the local gas puffing used for LH coupling. Furthermore, experiments carried out in L-mode plasmas in order to evaluate the effect on the LH current drive efficiency, when using local gas injection to improve the coupling, indicate only a small degradation (ΔI LH /I LH ∼ 15%). This effect is largely compensated by the improvement in coupling and thus increase in coupled power when using gas puffing.

  9. Bio-equivalent doses of recombinent HCG and recombinent LH during ovarian stimulation result in similar oestradiol output

    DEFF Research Database (Denmark)

    Alsbjerg, Birgit; Elbaek, Helle Olesen; Laursen, Rita Jakubcionyte

    2017-01-01

    In nature, HCG is secreted by the implanting embryo from peri-implantation and onwards. In contrast, LH is mandatory for steroidogenesis and follicular development during the follicular phase, working in synergy with FSH. Moreover, LH is mandatory for the function of the corpus luteum. Although LH...... and HCG bind to the same receptor, significant molecular, structural and functional differences exist, inducing differences in bioactivity. This randomized controlled study compared the effect of recombinant FSH stimulation combined with daily either micro-dose recombinant HCG or recombinant LH...

  10. Results of Semiscale Mod-2C small-break (5%) loss-of-coolant accident. Experiments S-LH-1 and S-LH-2

    International Nuclear Information System (INIS)

    Loomis, G.G.; Streit, J.E.

    1985-11-01

    Two experiments simulating small break (5%) loss-of-coolant accidents (5% SBLOCAs) were performed in the Semiscale Mod-2C facility. These experiments were identical except for downcomer-to-upper-head bypass flow (0.9% in Experiment S-LH-1 and 3.0% in Experiment S-LH-2) and were performed at high pressure and temperature [15.6 MPa (2262 psia) system pressure; 37 K (67 0 F) core differential temperature; 595 K(610 0 F) hot leg fluid temperature]. From the experimental results, the signature response and transient mass distribution are determined for a 5% SBLOCA. The core thermal-hydraulic response is characterized, including core void distribution maps, and the effect of core bypass flow on transient severity is assessed. Comparisons are made between postexperiment RELAP5 calculations and the experimental results, and the capability of RELAP5 to calculate the phenomena is assessed. 115 figs

  11. Initial results of high resolution L-H transition studies on DIII-D

    International Nuclear Information System (INIS)

    Wang, G; Rhodes, T L; Doyle, E J; Peebles, W A; Zeng, L; Burrell, K H; McKee, G R; Groebner, R J; Evans, T E

    2004-01-01

    Understanding the L-H transition in tokamaks has been an important area of research for more than two decades. High time resolution diagnostics on DIII-D allow detailed characterization of the L-H transition and, therefore, testing and benchmarking of theoretical models. An experiment was performed in DIII-D utilizing a novel, high temporal and spatial resolution reflectometer density profile system to measure densities from the SOL to the inside separatrix. Initial data analysis indicates different density profile evolution during L-H transitions in upper single-null and lower single-null divertor configuration plasmas. A detailed comparison of the density gradient and fluctuation changes is presented for these two cases

  12. An Ab Initio Description of the Excitonic Properties of LH2 and Their Temperature Dependence.

    Science.gov (United States)

    Cupellini, Lorenzo; Jurinovich, Sandro; Campetella, Marco; Caprasecca, Stefano; Guido, Ciro A; Kelly, Sharon M; Gardiner, Alastair T; Cogdell, Richard; Mennucci, Benedetta

    2016-11-10

    The spectroscopic properties of light-harvesting (LH) antennae in photosyntehtic organisms represent a fingerprint that is unique for each specific pigment-protein complex. Because of that, spectroscopic observations are generally combined with structural data from X-ray crystallography to obtain an indirect representation of the excitonic properties of the system. Here, an alternative strategy is presented which goes beyond this empirical approach and introduces an ab initio computational description of both structural and electronic properties and their dependence on the temperature. The strategy is applied to the peripheral light-harvesting antenna complex (LH2) present in purple bacteria. By comparing this model with the one based on the crystal structure, a detailed, molecular level explanation of the absorption and circular dichroism (CD) spectra and their temperature dependence is achieved. The agreement obtained with the experiments at both low and room temperature lays the groundwork for an atomistic understanding of the excitation dynamics in the LH2 system.

  13. Directed formation of micro- and nanoscale patterns of functional light-harvesting LH2 complexes.

    Science.gov (United States)

    Reynolds, Nicholas P; Janusz, Stefan; Escalante-Marun, Maryana; Timney, John; Ducker, Robert E; Olsen, John D; Otto, Cees; Subramaniam, Vinod; Leggett, Graham J; Hunter, C Neil

    2007-11-28

    The precision placement of the desired protein components on a suitable substrate is an essential prelude to any hybrid "biochip" device, but a second and equally important condition must also be met: the retention of full biological activity. Here we demonstrate the selective binding of an optically active membrane protein, the light-harvesting LH2 complex from Rhodobacter sphaeroides, to patterned self-assembled monolayers at the micron scale and the fabrication of nanometer-scale patterns of these molecules using near-field photolithographic methods. In contrast to plasma proteins, which are reversibly adsorbed on many surfaces, the LH2 complex is readily patterned simply by spatial control of surface polarity. Near-field photolithography has yielded rows of light-harvesting complexes only 98 nm wide. Retention of the native optical properties of patterned LH2 molecules was demonstrated using in situ fluorescence emission spectroscopy.

  14. Reciprocating Probe Measurements of L-H Transition in LHCD H-mode on EAST

    DEFF Research Database (Denmark)

    Peng, Liu; Guosheng, Xu; Huiqian, Wang

    2013-01-01

    that the power loss P loss was comparable during the L-H transition, by comparing the adjacent L-mode and H-mode discharge. The Dα emission, Te and ne decreased rapidly in the time scale of about 1 ms, and the radial electric field Er turned positive in this process near the last closed flux surface. Multiple L......-H-L transitions were observed during a single shot when the applied LHW power was marginal to the threshold. The floating potential (Vf) had negative spikes corresponding with the Dα signal, and Er oscillation evolved into several intermittent negative spikes just before the L-H transition. In some shots......, dithering was observed just before the L-H transition....

  15. Initial results of high resolution L-H transition studies on DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Wang, G [Department of Electrical Engineering and PSTI, University of California, Los Angeles, CA 90095 (United States); Rhodes, T L [Department of Electrical Engineering and PSTI, University of California, Los Angeles, CA 90095 (United States); Doyle, E J [Department of Electrical Engineering and PSTI, University of California, Los Angeles, CA 90095 (United States); Peebles, W A [Department of Electrical Engineering and PSTI, University of California, Los Angeles, CA 90095 (United States); Zeng, L [Department of Electrical Engineering and PSTI, University of California, Los Angeles, CA 90095 (United States); Burrell, K H [General Atomics, PO Box 85608, San Diego, CA 92186 (United States); McKee, G R [University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706 (United States); Groebner, R J [General Atomics, PO Box 85608, San Diego, CA 92186 (United States); Evans, T E [General Atomics, PO Box 85608, San Diego, CA 92186 (United States)

    2004-05-01

    Understanding the L-H transition in tokamaks has been an important area of research for more than two decades. High time resolution diagnostics on DIII-D allow detailed characterization of the L-H transition and, therefore, testing and benchmarking of theoretical models. An experiment was performed in DIII-D utilizing a novel, high temporal and spatial resolution reflectometer density profile system to measure densities from the SOL to the inside separatrix. Initial data analysis indicates different density profile evolution during L-H transitions in upper single-null and lower single-null divertor configuration plasmas. A detailed comparison of the density gradient and fluctuation changes is presented for these two cases.

  16. Evolution of Edge Pedestal Profiles Over the L-H Transition

    Science.gov (United States)

    Sayer, M. S.; Stacey, W. M.; Floyd, J. P.; Groebner, R. J.

    2012-10-01

    The detailed time evolution of thermal diffusivities, electromagnetic forces, pressure gradients, particle pinch and momentum transport frequencies (which determine the diffusion coefficient) have been analyzed during the L-H transition in a DIII-D discharge. Density, temperature, rotation velocity and electric field profiles at times just before and after the L-H transition are analyzed in terms of these quantities. The analysis is based on the fluid particle balance, energy balance, force balance and heat conduction equations, as in Ref. [1], but with much greater time resolution and with account for thermal ion orbit loss. The variation of diffusive and non-diffusive transport over the L-H transition is determined from the variation in the radial force balance (radial electric field, VxB force, and pressure gradient) and the variation in the interpreted diffusive transport coefficients. 6pt [1] W.M. Stacey and R.J. Groebner, Phys. Plasmas 17, 112512 (2010).

  17. Dependence between sea surge, river flow and precipitation in south and west Britain

    Directory of Open Access Journals (Sweden)

    C. Svensson

    2004-01-01

    Full Text Available Estuaries around Great Britain may be at heightened risk of flooding because of the simultaneous occurrence of extreme sea surge and river flow, both of which may be caused by mid-latitude cyclones. A measure especially suited for extremes was employed to estimate dependence between river flow and sea surge. To assist in the interpretation of why flow-surge dependence occurs in some areas and not in others, the dependence between precipitation and surge and between precipitation and river flow was also studied. Case studies of the meteorological situations leading to high surges and/or river flows were also carried out. The present study concerns catchments draining to the south and west coasts of Great Britain. Statistically significant dependence between river flow and daily maximum sea surge may be found at catchments spread along most of this coastline. However, higher dependence is generally found in catchments in hilly areas with a southerly to westerly aspect. Here, precipitation in south-westerly airflow, which is generally the quadrant of prevailing winds, will be enhanced orographically as the first higher ground is encountered. The sloping catchments may respond quickly to the abundant rainfall and the flow peak may arrive in the estuary on the same day as a large sea surge is produced by the winds and low atmospheric pressure associated with the cyclone. There are three regions where flow-surge dependence is strong: the western part of the English south coast, southern Wales and around the Solway Firth. To reduce the influence of tide-surge interaction on the dependence analysis, the dependence between river flow and daily maximum surge occurring at high tide was estimated. The general pattern of areas with higher dependence is similar to that using the daily maximum surge. The dependence between river flow and daily maximum sea surge is often strongest when surge and flow occur on the same day. The west coast from Wales and

  18. Stability of integral membrane proteins under high hydrostatic pressure: the LH2 and LH3 antenna pigment-protein complexes from photosynthetic bacteria.

    Science.gov (United States)

    Kangur, Liina; Timpmann, Kõu; Freiberg, Arvi

    2008-07-03

    The bacteriochlorophyll a-containing LH2 and LH3 antenna complexes are the integral membrane proteins that catalyze the photosynthetic process in purple photosynthetic bacteria. The LH2 complex from Rhodobacter sphaeroides shows characteristic strong absorbance at 800 and 850 nm due to the pigment molecules confined in two separate areas of the protein. In the LH3 complex from Rhodopesudomonas acidophila the corresponding bands peak at 800 and 820 nm. Using the bacteriochlorophyll a cofactors as intrinsic probes to monitor local changes in the protein structure, we investigate spectral responses of the antenna complexes to very high hydrostatic pressures up to 2.5 GPa when embedded into natural membrane environment or extracted with detergent. We first demonstrate that high pressure does induce significant alterations to the tertiary structure of the proteins not only in proximity of the 800 nm-absorbing bacteriochlorophyll a molecules known previously (Gall, A.; et al. Biochemistry 2003, 42, 13019) but also of the 850 nm- and 820 nm-absorbing molecules, including breakage of the hydrogen bond they are involved in. The membrane-protected complexes appear more resilient to damaging effects of the compression compared with the complexes extracted into mixed detergent-buffer environment. Increased resistance of the isolated complexes is observed at high protein concentration resulting aggregation as well as when cosolvent (glycerol) is added into the solution. These stability variations correlate with ability of penetration of the surrounding polar solvent (water) into the hydrophobic protein interiors, being thus the principal reason of the pressure-induced denaturation of the proteins. Considerable variability of elastic properties of the isolated complexes was also observed, tentatively assigned to heterogeneous protein packing in detergent micelles. While a number of the isolated complexes release most of their bacteriochlorophyll a content under high pressure

  19. Comparison of two recent storm surge events based on results of field surveys

    Science.gov (United States)

    Nakamura, Ryota; Shibayama, Tomoya; Mikami, Takahito; Esteban, Miguel; Takagi, Hiroshi; Maell, Martin; Iwamoto, Takumu

    2017-10-01

    This paper compares two different types of storm surge disaster based on field surveys. Two cases: a severe storm surge flood with its height of over 5 m due to Typhoon Haiyan (2013) in Philippine, and inundation of storm surge around Nemuro city in Hokkaido of Japan with its maximum surge height of 2.8 m caused by extra-tropical cyclone are taken as examples. For the case of the Typhoon Haiyan, buildings located in coastal region were severely affected due to a rapidly increase in ocean surface. The non-engineering buildings were partially or completely destroyed due to their debris transported to an inner bay region. In fact, several previous reports indicated two unique features, bore-like wave and remarkably high speed currents. These characteristics of the storm surge may contribute to a wide-spread corruption for the buildings around the affected region. Furthermore, in the region where the surge height was nearly 3 m, the wooden houses were completely or partially destroyed. On the other hand, in Nemuro city, a degree of suffering in human and facility caused by the storm surge is minor. There was almost no partially destroyed residential houses even though the height of storm surge reached nearly 2.8 m. An observation in the tide station in Nemuro indicated that this was a usual type of storm surge, which showed a gradual increase of sea level height in several hours without possessing the unique characteristics like Typhoon Haiyan. As a result, not only the height of storm surge but also the robustness of the buildings and characteristics of storm surge, such as bore like wave and strong currents, determined the existent of devastation in coastal regions.

  20. Photosynthetic complex LH2 – Absorption and steady state fluorescence spectra

    International Nuclear Information System (INIS)

    Zapletal, David; Heřman, Pavel

    2014-01-01

    Nowadays, much effort is devoted to the study of photosynthesis which could be the basis for an ideal energy source in the future. To be able to create such an energy source – an artificial photosynthetic complex, the first step is a detailed understanding of the function of photosynthetic complexes in living organisms. Photosynthesis starts with the absorption of a solar photon by one of the LH (light-harvesting) pigment–protein complexes and transferring the excitation energy to the reaction center where a charge separation is initiated. The geometric structure of some LH complexes is known in great detail, e.g. for the LH2 complexes of purple bacteria. For understanding of photosynthesis first stage efficiency, it is necessary to study especially optical properties of LH complexes. In this paper we present simulated absorption and steady-state fluorescence spectra for ring molecular system within full Hamiltonian model. Such system can model bacteriochlorophyll ring of peripheral light-harvesting complex LH2 from purple bacterium Rhodopseudomonas acidophila (Rhodoblastus acidophilus). Dynamic disorder (coupling with phonon bath) simultaneously with uncorrelated static disorder (transfer integral fluctuations) is used in our present simulations. We compare and discuss our new results with our previously published ones and of course with experimental data. - Highlights: • We model absorption and steady state fluorescence spectra for B850 ring from LH2. • Fluctuations of environment is modelled by static and dynamic disorder. • Full Hamiltonian model is compared with the nearest neighbour approximation one. • Simulated fluorescence spectrum is compared with experimental data

  1. ASASSN-15LH: A SUPERLUMINOUS ULTRAVIOLET REBRIGHTENING OBSERVED BY SWIFT AND HUBBLE

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Peter J.; Yang, Yi; Wang, Lifan [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A. and M. University, Department of Physics and Astronomy, 4242 TAMU, College Station, TX 77843 (United States); Cooke, Jeff; Mould, Jeremy [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn VIC 3122 (Australia); Olaes, Melanie; Quimby, Robert M. [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); Baade, Dietrich [European Organisation for Astronomical Research in the Southern Hemisphere (ESO), Karl-Schwarzschild-Str. 2, D-85748 Garching b. München (Germany); Gehrels, Neil [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hoeflich, Peter [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Maund, Justyn [Department of Physics and Astronomy F39 Hicks Building, Hounsfield Road Sheffield, S3 7RH (United Kingdom); Wheeler, J. Craig [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States)

    2016-09-01

    We present and discuss ultraviolet and optical photometry from the Ultraviolet/Optical Telescope, X-ray limits from the X-Ray Telescope on Swift, and imaging polarimetry and ultraviolet/optical spectroscopy with the Hubble Space Telescope , all from observations of ASASSN-15lh. It has been classified as a hydrogen-poor superluminous supernova (SLSN I), making it more luminous than any other supernova observed. ASASSN-15lh is not detected in the X-rays in individual or co-added observations. From the polarimetry we determine that the explosion was only mildly asymmetric. We find the flux of ASASSN-15lh to increase strongly into the ultraviolet, with an ultraviolet luminosity 100 times greater than the hydrogen-rich, ultraviolet-bright SLSN II SN 2008es. We find that objects as bright as ASASSN-15lh are easily detectable beyond redshifts of ∼4 with the single-visit depths planned for the Large Synoptic Survey Telescope. Deep near-infrared surveys could detect such objects past a redshift of ∼20, enabling a probe of the earliest star formation. A late rebrightening—most prominent at shorter wavelengths—is seen about two months after the peak brightness, which is itself as bright as an SLSN. The ultraviolet spectra during the rebrightening are dominated by the continuum without the broad absorption or emission lines seen in SLSNe or tidal disruption events (TDEs) and the early optical spectra of ASASSN-15lh. Our spectra show no strong hydrogen emission, showing only Ly α absorption near the redshift previously found by optical absorption lines of the presumed host. The properties of ASASSN-15lh are extreme when compared to either SLSNe or TDEs.

  2. Surge of Bering Glacier and Bagley Ice Field: Parameterization of surge characteristics based on automated analysis of crevasse image data and laser altimeter data

    Science.gov (United States)

    Stachura, M.; Herzfeld, U. C.; McDonald, B.; Weltman, A.; Hale, G.; Trantow, T.

    2012-12-01

    The dynamical processes that occur during the surge of a large, complex glacier system are far from being understood. The aim of this paper is to derive a parameterization of surge characteristics that captures the principle processes and can serve as the basis for a dynamic surge model. Innovative mathematical methods are introduced that facilitate derivation of such a parameterization from remote-sensing observations. Methods include automated geostatistical characterization and connectionist-geostatistical classification of dynamic provinces and deformation states, using the vehicle of crevasse patterns. These methods are applied to analyze satellite and airborne image and laser altimeter data collected during the current surge of Bering Glacier and Bagley Ice Field, Alaska.

  3. Pre-swirl mechanism in front of a centrifugal compressor: effects on surge line and on unsteady phenomena in surge area

    Directory of Open Access Journals (Sweden)

    Danlos Amélie

    2017-01-01

    Full Text Available Using a pre-swirl mechanism upstream an impeller of a compressor allows to modify its characteristics curve, while weakly damaging its efficiency. Another consequence of the pre-swirl is to push back the surge line limit and to increase the operation zone towards the low flow rate limits. A centrifugal compressor has been modified in order to add a swirl generator device upstream the impeller. The incidence values of blades can vary from 0° (no pre-swirl to ±90°. The variation of the stator blades incidence has several main consequences: to allow a flow rate adjustment with a good efficiency conservation, to increase the angular velocity with a constant shaft power, to produce a displacement of the surge line limit. In this paper, the results of experimental studies are presented to analyze the surge line and the intensity of unsteady phenomena when the compressor works in its surge area.

  4. Developmental programming: Impact of fetal exposure to endocrine-disrupting chemicals on gonadotropin-releasing hormone and estrogen receptor mRNA in sheep hypothalamus

    International Nuclear Information System (INIS)

    Mahoney, Megan M.; Padmanabhan, Vasantha

    2010-01-01

    Bisphenol-A (BPA) and methoxychlor (MXC), two endocrine-disrupting chemicals (EDCs) with estrogenic and antiandrogenic effects, disrupt the reproductive system. BPA has profound effects on luteinizing hormone (LH) surge amplitude, and MXC has profound effects on on LH surge timing in sheep. The neural mechanisms involved in the differential disruption of the LH surge by these two EDCs remain to be elucidated. We tested the hypothesis that the differential effects of BPA and MXC on LH surge system involved changes in hypothalamic gonadotropin-releasing hormone (GnRH) and estrogen receptors (ESR), ESR1 and ESR2, mRNA expression. Pregnant sheep were given daily injections of cottonseed oil (controls), MXC, or BPA (5 mg/kg/day) from day 30 to 90 of gestation (term 147 d). Offspring from these animals were euthanized as adults, during the late follicular phase following synchronization of estrus with prostaglandin F 2α , just before the expected onset of preovulatory LH surge and changes in mRNA expression of hypothalamic GnRH, ESR1, and ESR2 quantified following in situ hybridization. GnRH mRNA expression was significantly lower in both groups of EDC-treated females compared to controls. ESR1 expression was increased in prenatal BPA- but not MXC-treated females in medial preoptic area relative to controls. In contrast, ESR2 expression was reduced in the medial preoptic area of both EDC-treated groups. Differences in expression of ESR1/ESR2 receptors may contribute to the differential effects of BPA and MXC on the LH surge system. These findings provide support that prenatal exposure to EDCs alters the neural developmental trajectory leading to long-term reproductive consequences in the adult female.

  5. Developmental programming: impact of fetal exposure to endocrine-disrupting chemicals on gonadotropin-releasing hormone and estrogen receptor mRNA in sheep hypothalamus.

    Science.gov (United States)

    Mahoney, Megan M; Padmanabhan, Vasantha

    2010-09-01

    Bisphenol-A (BPA) and methoxychlor (MXC), two endocrine-disrupting chemicals (EDCs) with estrogenic and antiandrogenic effects, disrupt the reproductive system. BPA has profound effects on luteinizing hormone (LH) surge amplitude, and MXC has profound effects on on LH surge timing in sheep. The neural mechanisms involved in the differential disruption of the LH surge by these two EDCs remain to be elucidated. We tested the hypothesis that the differential effects of BPA and MXC on LH surge system involved changes in hypothalamic gonadotropin-releasing hormone (GnRH) and estrogen receptors (ESR), ESR1 and ESR2, mRNA expression. Pregnant sheep were given daily injections of cottonseed oil (controls), MXC, or BPA (5mg/kg/day) from day 30 to 90 of gestation (term 147d). Offspring from these animals were euthanized as adults, during the late follicular phase following synchronization of estrus with prostaglandin F(2alpha), just before the expected onset of preovulatory LH surge and changes in mRNA expression of hypothalamic GnRH, ESR1, and ESR2 quantified following in situ hybridization. GnRH mRNA expression was significantly lower in both groups of EDC-treated females compared to controls. ESR1 expression was increased in prenatal BPA- but not MXC-treated females in medial preoptic area relative to controls. In contrast, ESR2 expression was reduced in the medial preoptic area of both EDC-treated groups. Differences in expression of ESR1/ESR2 receptors may contribute to the differential effects of BPA and MXC on the LH surge system. These findings provide support that prenatal exposure to EDCs alters the neural developmental trajectory leading to long-term reproductive consequences in the adult female. 2010 Elsevier Inc. All rights reserved.

  6. Vital signs : all gauges register a lasting surge in activity

    International Nuclear Information System (INIS)

    Lunan, D.

    2000-01-01

    The petroleum and natural gas industry is currently in the midst of a surge in activity with respect to land sales and metres drilled just to meet the demand, particularly for natural gas. Land sale activity is considered to be a key indicator for forecasting drilling activity. Drilling activity is also up since producers are trying to find new reserves to meet future years of forecasted strong demand growth, particularly from the United States. In one year, since June 1999, the average price paid for oil and gas rights rose nearly 80 per cent to just under $300 per hectare. Lease and licence bonus payments were also up from $27 million to $72.1 million. The surge in drilling activity has resulted in all basins reporting at least modest improvements. In the Western Canadian Sedimentary Basin, completions in Alberta for the first half of year 2000 were up 10 per cent with gas wells ahead of oil completions by a two-to-one margin. Exploration drilling is down compared to development drilling because of immediate demand expectations. Overall, industry drilled about 1.6 million metres of hole through the first half of year 2000, up from just over 5 million metres last year. More attention is being given to deeper gas plays. Total expenditures are forecasted to exceed the $30 billion mark, up from $26.3 billion last year and surpassing the $28 billion spent during Canada's big drilling boom in 1997. With crude oil prices holding up and gas prices running to record levels due to strong demand and low storage reserves, revenues this year will jump to nearly $42 billion from about $32.5 billion in 1999. The following industry charts for the first half of year 2000 were included: (1) well depths, (2) success ratios of well completions, (3) Canadian petroleum production, (4) Canadian exploration and production revenues and expenditures, and (5) land sale summaries. 5 tabs., 1 fig

  7. Role of cold surge and MJO on rainfall enhancement over indonesia during east asian winter monsoon

    Science.gov (United States)

    Fauzi, R. R.; Hidayat, R.

    2018-05-01

    Intensity of precipitation in Indonesia is influenced by convection and propagation of southwest wind. Objective of this study is to analyze the relationship between cold surge and the phenomenon of intra-seasonal climate variability Madden-julian Oscillation (MJO) for affecting precipitation in Indonesia. The data used for identifying the occurrence of cold surge are meridional wind speed data from the ERA-Interim. In addition, this study also used RMM1 and RMM2 index data from Bureau of Meteorology (BOM) for identifying MJO events. The results showed that during East Asian Winter Monsoon (EAWM) in 15 years (2000-2015), there are 362 cold surge events, 186 MJO events, and 113 cold surge events were associated with MJO events. The spread of cold surge can penetrate to equator and brought mass of water vapor that causes dominant precipitation in the Indonesian Sea up to 50-75% from climatological precipitation during EAWM. The MJO convection activity that moves from west to east also increases precipitation, but the distribution of rainfall is wider than cold surge, especially in Eastern Indonesia. MJO and cold surge simultaneously can increase rainfall over 100-150% in any Indonesian region that affected by MJO and cold surge events. The mechanism of heavy rainfall is illustrated by high activity of moisture transport in areas such as Java Sea and coastal areas of Indonesia.

  8. Storm surge in the Bay of Bengal and Arabian Sea: The problem and its prediction

    Digital Repository Service at National Institute of Oceanography (India)

    Dube, S.K.; Rao, A.D.; Sinha, P.C.; Murty, T.S.; Bahulayan, N.

    to annual economic losses in these countries. Thus, the real time monitoring and warning of storm surge is of great concern for this region. The goal of this paper is to provide an overview of major aspects of the storm surge problem in the Bay of Bengal...

  9. Numerical modelling of tides and storm surges in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sindhu, B.

    were done. A storm surge model was developed to simulate total water levels and derived surges caused by low pressure systems identified during the past 27 years (1974-2000) in the Bay of Bengal. Study also estimated the return levels of extreme sea...

  10. Data Assimilation within the Advanced Circulation (ADCIRC) Modeling Framework for Hurricane Storm Surge Forecasting

    KAUST Repository

    Butler, T.; Altaf, Muhammad; Dawson, C.; Hoteit, Ibrahim; Luo, X.; Mayo, T.

    2012-01-01

    levels, and wave heights—during these extreme events. This type of data, if available in real time, could be used in a data assimilation framework to improve hurricane storm surge forecasts. In this paper a data assimilation methodology for storm surge

  11. Effect of Tide Elevation on Extratropical Storm Surge in Northwest Europe

    Science.gov (United States)

    Keshtpoor, M.; Carnacina, I.; Yablonsky, R. M.

    2016-12-01

    Extratropical cyclones (ETCs) are the major storm surge-generating meteorological events in northwest Europe. The total water level increase induced by these ETCs is significantly influenced by the local tidal range, which exceeds 8 meters along the southwestern UK coastline. In particular, a surge-generating ETC during high tide may put coastal assets and infrastructure in risk. Also, during low tide, the risk of surge induced by extreme ETC events is diminished. Here, the effect of tidal elevation on storm surge is investigated at 196 tide gauges in northwest Europe. A numerical, hydrodynamic model was developed using Delft3D-FM framework to simulate the coastal hydrodynamics during ETCs. Then, 1750 historical events were simulated to investigate the pattern of coastal inundation. Results suggest that in areas with a large tidal range ( 8 meters) and during the time period surrounding high or low tide, the pattern of coastal hydrodynamics is governed by tide and not storm surge. This result is most evident near the English Channel and Bristol Channel, where low frequency maximum water levels are observed when storm surge is combined with high tide. In contrast, near the tidal phase reversal, coastal hydrodynamics responds primarily to the storm surge, and low frequency maximum water elevation largely depends on the surge. In the areas with a small tidal range, ETC strength determines the pattern of coastal inundation.

  12. Effects of aggregation on the excitation dynamics of LH2 from Thermochromatium tepidum in aqueous phase and in chromatophores.

    Science.gov (United States)

    Yang, Fan; Yu, Long-Jiang; Wang, Peng; Ai, Xi-Cheng; Wang, Zheng-Yu; Zhang, Jian-Ping

    2011-06-23

    We carried out femtosecond magic-angle and polarized pump-probe spectroscopies for the light-harvesting complex 2 (LH2) from Thermochromatium (Tch.) tepidum in aqueous phase and in chromatophores. To examine the effects of LH2 aggregation on the dynamics of excitation energy transfer, dominant monodispersed and aggregated LH2s were prepared by controlling the surfactant concentrations. The aqueous preparations solubilized with different concentrations of n-dodecyl-β-D-maltoside (DDM) show similar visible-to-near-infrared absorption spectra, but distinctively different aggregation states, as revealed by using dynamic light scattering. The B800 → B850 intra-LH2 energy transfer time was determined to be 1.3 ps for isolated LH2, which, upon aggregation in aqueous phase or clustering in chromatophores, shortened to 1.1 or 0.9 ps, respectively. The light-harvesting complex 1 (LH1) of this thermophilic purple sulfur bacterium contains bacteriochlorophyll a absorbing at 915 nm (B915), and the LH2(B850) → LH1(B915) intercomplex transfer time in chromatophores was found to be 6.6 ps. For chromatophores, a depolarization time of 21 ps was derived from the anisotropy kinetics of B850*, which is attributed to the migration of B850* excitation before being trapped by LH1. In addition, the B850* annihilation is accelerated upon LH2 aggregation in aqueous phase, but it is much less severe upon LH2 clustering in the intracytoplasmic membrane. These results are helpful in understanding the light-harvesting function of a bacterial photosynthetic membrane incorporating different types of antenna complexes.

  13. Artificial Neural Network forecasting of storm surge water levels at major estuarine ports to supplement national tide-surge models and improve port resilience planning

    Science.gov (United States)

    French, Jon; Mawdsley, Robert; Fujiyama, Taku; Achuthan, Kamal

    2017-04-01

    Effective prediction of tidal storm surge is of considerable importance for operators of major ports, since much of their infrastructure is necessarily located close to sea level. Storm surge inundation can damage critical elements of this infrastructure and significantly disrupt port operations and downstream supply chains. The risk of surge inundation is typically approached using extreme value analysis, while short-term forecasting generally relies on coastal shelf-scale tide and surge models. However, extreme value analysis does not provide information on the duration of a surge event and can be sensitive to the assumptions made and the historic data available. Also, whilst regional tide and surge models perform well along open coasts, their fairly coarse spatial resolution means that they do not always provide accurate predictions for estuarine ports. As part of a NERC Environmental Risks to Infrastructure Innovation Programme project, we have developed a tool that is specifically designed to forecast the North Sea storm surges on major ports along the east coast of the UK. Of particular interest is the Port of Immingham, Humber estuary, which handles the largest volume of bulk cargo in the UK including major flows of coal and biomass for power generation. A tidal surge in December 2013, with an estimated return period of 760 years, partly flooded the port, damaged infrastructure and disrupted operations for several weeks. This and other recent surge events highlight the need for additional tools to supplement the national UK Storm Tide Warning Service. Port operators are also keen to have access to less computationally expensive forecasting tools for scenario planning and to improve their resilience to actual events. In this paper, we demonstrate the potential of machine learning methods based on Artificial Neural Networks (ANNs) to generate accurate short-term forecasts of extreme water levels at estuarine North Sea ports such as Immingham. An ANN is

  14. Quantification of Sediment Transport During Glacier Surges and its Impact on Landform Architecture

    DEFF Research Database (Denmark)

    Kjær, Kurt H.; Schomacker, Anders; Korsgaard, Niels Jákup

    ) for 1945, prior to the last surge in 1964, and for 2003 in order to assess the effect of the surge on the sediment architecture in the forefield. The pre- and post-surge DEMs allow direct quantification of the sediment volumes that were re-distributed in the forefield by the surging ice mass in 1964...... or glaciofluvial outwash fans. Mapping of the sediment thickness in the glacier forefield shows higher accumulation along ice marginal positions related to wedge formation during extremely rapid ice flow. Fast flow was sustained by overpressurized water causing sediment-bedrock decoupling beneath a thick sediment...... architecture occurs distal to the 1810 ice margin, where the 1890 surge advanced over hitherto undeformed sediments. Proximal to the 1810 ice margin, the landscape have been transgressed by either one or two glaciers (in 1890 and 1964). The most complex landscape architecture is found proximal to the 1964 ice...

  15. Progression of the 2011-2012 Surge of Bering Glacier and Bagley Ice Field, Alaska

    Science.gov (United States)

    Herzfeld, U. C.; McDonald, B.; Stachura, M.; Hale, R.; Trantow, T.; Weltman, A.; Chen, P.

    2012-12-01

    Bering Glacier, Alaska, started a surge in late spring 2011. The surge reached the ice front in May 2011 and extended into Bagley Ice Field by summer 2011. New surge-related crevassing was observed in July 2012. We collected aerial observations, including systematic videographic and photographic imagery, GPS data and laser altimeter data in September 2011 and in July 2012. In this talk, an analysis of surge progression and comparison to the early, mature and late stages of the 1993-1995 surge of Bering Glacier and Bagley Ice Field will be presented. A suite of approaches will be used to this end: Analysis of elevation changes based on CryoSat data, 2009 and 2010 IceBridge data and 2011 and 2012 laser altimeter data collected by our group, geostatistical classification of crevasse types based on imagery, classification of laser altimeter data and analysis of high-resolution satellite imagery (Worldview and GEOS).

  16. Hurricane storm surge and amphibian communities in coastal wetlands of northwestern Florida

    Science.gov (United States)

    Gunzburger, M.S.; Hughes, W.B.; Barichivich, W.J.; Staiger, J.S.

    2010-01-01

    Isolated wetlands in the Southeastern United States are dynamic habitats subject to fluctuating environmental conditions. Wetlands located near marine environments are subject to alterations in water chemistry due to storm surge during hurricanes. The objective of our study was to evaluate the effect of storm surge overwash on wetland amphibian communities. Thirty-two wetlands in northwestern Florida were sampled over a 45-month period to assess amphibian species richness and water chemistry. During this study, seven wetlands were overwashed by storm surge from Hurricane Dennis which made landfall 10 July 2005 in the Florida panhandle. This event allowed us to evaluate the effect of storm surge overwash on water chemistry and amphibian communities of the wetlands. Specific conductance across all wetlands was low pre-storm (marine habitats are resistant to the effects of storm surge overwash. ?? 2010 Springer Science+Business Media B.V.

  17. Condition Assessment of Metal Oxide Surge Arrester Based on Multi-Layer SVM Classifier

    Directory of Open Access Journals (Sweden)

    M Khodsuz

    2015-12-01

    Full Text Available This paper introduces the indicators for surge arrester condition assessment based on the leakage current analysis. Maximum amplitude of fundamental harmonic of the resistive leakage current, maximum amplitude of third harmonic of the resistive leakage current and maximum amplitude of fundamental harmonic of the capacitive leakage current were used as indicators for surge arrester condition monitoring. Also, the effects of operating voltage fluctuation, third harmonic of voltage, overvoltage and surge arrester aging on these indicators were studied. Then, obtained data are applied to the multi-layer support vector machine for recognizing of surge arrester conditions. Obtained results show that introduced indicators have the high ability for evaluation of surge arrester conditions.

  18. Storm surge and wave simulations in the Gulf of Mexico using a consistent drag relation for atmospheric and storm surge models

    Directory of Open Access Journals (Sweden)

    D. Vatvani

    2012-07-01

    Full Text Available To simulate winds and water levels, numerical weather prediction (NWP and storm surge models generally use the traditional bulk relation for wind stress, which is characterized by a wind drag coefficient. A still commonly used drag coefficient in those models, some of them were developed in the past, is based on a relation, according to which the magnitude of the coefficient is either constant or increases monotonically with increasing surface wind speed (Bender, 2007; Kim et al., 2008; Kohno and Higaki, 2006. The NWP and surge models are often tuned independently from each other in order to obtain good results. Observations have indicated that the magnitude of the drag coefficient levels off at a wind speed of about 30 m s−1, and then decreases with further increase of the wind speed. Above a wind speed of approximately 30 m s−1, the stress above the air-sea interface starts to saturate. To represent the reducing and levelling off of the drag coefficient, the original Charnock drag formulation has been extended with a correction term.

    In line with the above, the Delft3D storm surge model is tested using both Charnock's and improved Makin's wind drag parameterization to evaluate the improvements on the storm surge model results, with and without inclusion of the wave effects. The effect of waves on storm surge is included by simultaneously simulating waves with the SWAN model on identical model grids in a coupled mode. However, the results presented here will focus on the storm surge results that include the wave effects.

    The runs were carried out in the Gulf of Mexico for Katrina and Ivan hurricane events. The storm surge model was initially forced with H*wind data (Powell et al., 2010 to test the effect of the Makin's wind drag parameterization on the storm surge model separately. The computed wind, water levels and waves are subsequently compared with observation data. Based on the good

  19. Temporal concentrations of cortisol and LH in virgin ewes acutely exposed to rams during the transition into the breeding season.

    Science.gov (United States)

    McCosh, R B; Berry, E M; Wehrman, M E; Redden, R R; Hallford, D M; Berardinelli, J G

    2015-03-01

    The objectives of this study were to determine if exposing seasonally anovular ewes to rams would alter patterns of cortisol concentrations, and if these changes are associated with changes in characteristics of LH concentrations. Seasonally anestrous ewes were assigned to be exposed to rams (RE; n=11) or wethers (NE; n=12). Blood samples were collected at 15-min intervals beginning 120 min before introduction of males (time=0 min), and continued for 360 min after male exposure. Characteristics of cortisol and LH concentrations included: mean and baseline concentrations, pulse amplitude, duration, frequency, and time to first pulse. Mean and baseline cortisol concentrations, and cortisol pulse amplitude, frequency, and time to first pulse after male exposure did not differ between RE and NE ewes. Cortisol pulse duration was longer (Pewes than in NE ewes. Mean LH and LH pulse amplitude, duration, and time to first pulse after male exposure did not differ between RE and NE ewes. Baseline LH concentrations and LH pulse frequency were greater (Pewes. In RE ewes, but not NE ewes, LH pulse frequency tended to increase (P=0.06) as pulse frequency of cortisol decreased. In conclusion, exposing ewes to mature rams during the transition into the breeding season increased LH pulse frequency which hastened ovulatory activity. However, the results do not support the hypothesis that changes in cortisol concentrations plays a significant role in the 'ram effect'. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Metal Cations Induced alpha beta-BChl a Heterogeneity in LH1 as Revealed by Temperature-Dependent Fluorescence Splitting

    NARCIS (Netherlands)

    Ma, Fei; Yu, Long-Jiang; Llansola-Portoles, Manuel J.; Robert, Bruno; Wang-Otomo, Zheng-Yu; van Grondelle, Rienk

    2017-01-01

    Two spectral forms of the core light-harvesting complex (LH1) of the purple bacterium Thermochromatium (Tch.) tepidum, the native Ca2+-binding and the Ba2+-substituted one, exhibit different fluorescence (FL) emission spectra at low temperature (T). While Ca-LH1 exhibits one emission band, an

  1. Construction of hybrid photosynthetic units using peripheral and core antennae from two different species of photosynthetic bacteria: detection of the energy transfer from bacteriochlorophyll a in LH2 to bacteriochlorophyll b in LH1.

    Science.gov (United States)

    Fujii, Ritsuko; Shimonaka, Shozo; Uchida, Naoko; Gardiner, Alastair T; Cogdell, Richard J; Sugisaki, Mitsuru; Hashimoto, Hideki

    2008-01-01

    Typical purple bacterial photosynthetic units consist of supra-molecular arrays of peripheral (LH2) and core (LH1-RC) antenna complexes. Recent atomic force microscopy pictures of photosynthetic units in intact membranes have revealed that the architecture of these units is variable (Scheuring et al. (2005) Biochim Bhiophys Acta 1712:109-127). In this study, we describe methods for the construction of heterologous photosynthetic units in lipid-bilayers from mixtures of purified LH2 (from Rhodopseudomonas acidophila) and LH1-RC (from Rhodopseudomonas viridis) core complexes. The architecture of these reconstituted photosynthetic units can be varied by controlling ratio of added LH2 to core complexes. The arrangement of the complexes was visualized by electron-microscopy in combination with Fourier analysis. The regular trigonal array of the core complexes seen in the native photosynthetic membrane could be regenerated in the reconstituted membranes by temperature cycling. In the presence of added LH2 complexes, this trigonal symmetry was replaced with orthorhombic symmetry. The small lattice lengths for the latter suggest that the constituent unit of the orthorhombic lattice is the LH2. Fluorescence and fluorescence-excitation spectroscopy was applied to the set of the reconstituted membranes prepared with various proportions of LH2 to core complexes. Remarkably, even though the LH2 complexes contain bacteriochlorophyll a, and the core complexes contain bacteriochlorophyll b, it was possible to demonstrate energy transfer from LH2 to the core complexes. These experiments provide a first step along the path toward investigating how changing the architecture of purple bacterial photosynthetic units affects the overall efficiency of light-harvesting.

  2. Operational Issues in the Development of a Cost-Effective Reusable LOX/LH2 Engine

    Science.gov (United States)

    Ballard, Richard O.

    2005-01-01

    Contents include the following: SLI initiated under NASA Research Announcement (NRA) 8-30. Strategic Objectives. Make spaceflight safer (1 in 10000 mission LOV). Make spaceflight cheaper ($1000/lb payload). Two prototype LOX/LH2 engine systems funded under Cycle-1 of NRA8-30. COBRA (Pratt & Whitney / Aerojet). RS-83 (Rocketdyne).

  3. Protein-induced geometric constraints and charge transfer in bacteriochlorophyll-histidine complexes in LH2.

    Science.gov (United States)

    Wawrzyniak, Piotr K; Alia, A; Schaap, Roland G; Heemskerk, Mattijs M; de Groot, Huub J M; Buda, Francesco

    2008-12-14

    Bacteriochlorophyll-histidine complexes are ubiquitous in nature and are essential structural motifs supporting the conversion of solar energy into chemically useful compounds in a wide range of photosynthesis processes. A systematic density functional theory study of the NMR chemical shifts for histidine and for bacteriochlorophyll-a-histidine complexes in the light-harvesting complex II (LH2) is performed using the BLYP functional in combination with the 6-311++G(d,p) basis set. The computed chemical shift patterns are consistent with available experimental data for positive and neutral(tau) (N(tau) protonated) crystalline histidines. The results for the bacteriochlorophyll-a-histidine complexes in LH2 provide evidence that the protein environment is stabilizing the histidine close to the Mg ion, thereby inducing a large charge transfer of approximately 0.5 electronic equivalent. Due to this protein-induced geometric constraint, the Mg-coordinated histidine in LH2 appears to be in a frustrated state very different from the formal neutral(pi) (N(pi) protonated) form. This finding could be important for the understanding of basic functional mechanisms involved in tuning the electronic properties and exciton coupling in LH2.

  4. Consideration of LH2 and LD2 cold neutron sources in heavy water reactor reflector

    International Nuclear Information System (INIS)

    Potapov, I.A.; Serebrov, A.P.

    2001-01-01

    The reactor power, the required CNS dimensions and power of the cryogenic equipment define the CNS type with maximized cold neutron production. Cold neutron fluxes from liquid hydrogen (LH 2 ) and liquid deuterium (LD 2 ) cold neutron sources (CNS) are analyzed. Different CNS volumes, presents and absence of reentrant holes inside the CNS, different adjustment of beam tube and containment are considered. (orig.)

  5. Single-molecule spectroscopy reveals photosynthetic LH2 complexes switch between emissive states.

    Science.gov (United States)

    Schlau-Cohen, Gabriela S; Wang, Quan; Southall, June; Cogdell, Richard J; Moerner, W E

    2013-07-02

    Photosynthetic organisms flourish under low light intensities by converting photoenergy to chemical energy with near unity quantum efficiency and under high light intensities by safely dissipating excess photoenergy and deleterious photoproducts. The molecular mechanisms balancing these two functions remain incompletely described. One critical barrier to characterizing the mechanisms responsible for these processes is that they occur within proteins whose excited-state properties vary drastically among individual proteins and even within a single protein over time. In ensemble measurements, these excited-state properties appear only as the average value. To overcome this averaging, we investigate the purple bacterial antenna protein light harvesting complex 2 (LH2) from Rhodopseudomonas acidophila at the single-protein level. We use a room-temperature, single-molecule technique, the anti-Brownian electrokinetic trap, to study LH2 in a solution-phase (nonperturbative) environment. By performing simultaneous measurements of fluorescence intensity, lifetime, and spectra of single LH2 complexes, we identify three distinct states and observe transitions occurring among them on a timescale of seconds. Our results reveal that LH2 complexes undergo photoactivated switching to a quenched state, likely by a conformational change, and thermally revert to the ground state. This is a previously unobserved, reversible quenching pathway, and is one mechanism through which photosynthetic organisms can adapt to changes in light intensities.

  6. Carotenoid-to-bacteriochlorophyll energy transfer through vibronic coupling in LH2 from Phaeosprillum molischianum.

    Science.gov (United States)

    Thyrhaug, Erling; Lincoln, Craig N; Branchi, Federico; Cerullo, Giulio; Perlík, Václav; Šanda, František; Lokstein, Heiko; Hauer, Jürgen

    2018-03-01

    The peripheral light-harvesting antenna complex (LH2) of purple photosynthetic bacteria is an ideal testing ground for models of structure-function relationships due to its well-determined molecular structure and ultrafast energy deactivation. It has been the target for numerous studies in both theory and ultrafast spectroscopy; nevertheless, certain aspects of the convoluted relaxation network of LH2 lack a satisfactory explanation by conventional theories. For example, the initial carotenoid-to-bacteriochlorophyll energy transfer step necessary on visible light excitation was long considered to follow the Förster mechanism, even though transfer times as short as 40 femtoseconds (fs) have been observed. Such transfer times are hard to accommodate by Förster theory, as the moderate coupling strengths found in LH2 suggest much slower transfer within this framework. In this study, we investigate LH2 from Phaeospirillum (Ph.) molischianum in two types of transient absorption experiments-with narrowband pump and white-light probe resulting in 100 fs time resolution, and with degenerate broadband 10 fs pump and probe pulses. With regard to the split Q x band in this system, we show that vibronically mediated transfer explains both the ultrafast carotenoid-to-B850 transfer, and the almost complete lack of transfer to B800. These results are beyond Förster theory, which predicts an almost equal partition between the two channels.

  7. Effect of different dose rates administration of FSH + LH (Pergonal®)

    African Journals Online (AJOL)

    The does were randomly assigned to 4 treatment groups administered of 19.0 IU, 38.0 IU and 76.0 IU FSH + LH (Pergonal®) and 1.0 ml physiological saline as the control treatment. The treatments were administered intramuscularly for 3 days consecutively. The results on the number of corpora lutea on the ovary did not ...

  8. Analysis of LH Launcher Arrays (Like the ITER One) Using the TOPLHA Code

    International Nuclear Information System (INIS)

    Maggiora, R.; Milanesio, D.; Vecchi, G.

    2009-01-01

    TOPLHA (Torino Polytechnic Lower Hybrid Antenna) code is an innovative tool for the 3D/1D simulation of Lower Hybrid (LH) antennas, i.e. accounting for realistic 3D waveguides geometry and for accurate 1D plasma models, and without restrictions on waveguide shape, including curvature. This tool provides a detailed performances prediction of any LH launcher, by computing the antenna scattering parameters, the current distribution, electric field maps and power spectra for any user-specified waveguide excitation. In addition, a fully parallelized and multi-cavity version of TOPLHA permits the analysis of large and complex waveguide arrays in a reasonable simulation time. A detailed analysis of the performances of the proposed ITER LH antenna geometry has been carried out, underlining the strong dependence of the antenna input parameters with respect to plasma conditions. A preliminary optimization of the antenna dimensions has also been accomplished. Electric current distribution on conductors, electric field distribution at the interface with plasma, and power spectra have been calculated as well. The analysis shows the strong capabilities of the TOPLHA code as a predictive tool and its usefulness to LH launcher arrays detailed design.

  9. Comparison of four mathematical models for the calculation of radioimmunoassay data of LH, FSH and GH

    International Nuclear Information System (INIS)

    Geier, T.; Rohde, W.

    1981-01-01

    Weighted linear logit-log regression, point-to-point logit-log interpolation, smoothing spline approximation and the four-parameter logistic function calculated by non-linear regression have been compared. The data for comparison have been obtained from two different pool-sera for each of the LH-, FSH- and GH-RIA and from the basal serum LH values of two populations of children. The Wilcoxon matched pairs signed rank test was used for comparison: For GH there is no significant difference between all methods, for FSH the weighted linear logit-log regression and spline approximation appeared to be equivalent, but for LH no unequivocal assertion can be made. There is no significant difference between the mathematical models for determination of hormone concentration within one assay run of a population as exemplified for LH. In addition, pool sera data were subjected to an analysis of variance and the comparison of the results revealed that the different models did not lead to different statements about assay performance. The point-to-point logit-log interpolation is proposed as most simple curvilinear approximation for assays which cannot be linearized by logit-log transformation. (author)

  10. Preparatory separation of the silymarin flavonolignans by Sephadex LH-20 gel

    Czech Academy of Sciences Publication Activity Database

    Křenek, Karel; Marhol, Petr; Peikerová, Žaneta; Křen, Vladimír; Biedermann, David

    2014-01-01

    Roč. 65, č. 1 (2014), s. 115-120 ISSN 0963-9969 R&D Projects: GA ČR(CZ) GAP301/11/0662; GA MŠk LH13097; GA MŠk(CZ) LD13041 Institutional support: RVO:61388971 Keywords : silymarin * silybin * nutraceutical Subject RIV: CE - Biochemistry Impact factor: 2.818, year: 2014

  11. Effect of medium type and luteinizing hormone (LH) on in vitro ...

    African Journals Online (AJOL)

    Maturation rate was assessed by evaluation of degree of cumulus cells expansion and meiotic development. Results indicate that recovery rate ranged between 2.4 to 2.8. Moreover, results revealed that maturation rate, telophase and metaphase II stages were higher for oocytes matured in TCM-199 + LH than oocytes ...

  12. Sequencing and generation of an infectious clone of the pathogenic goose parvovirus strain LH.

    Science.gov (United States)

    Wang, Jianye; Duan, Jinkun; Zhu, Liqian; Jiang, Zhiwei; Zhu, Guoqiang

    2015-03-01

    In this study, the complete genome of the virulent strain LH of goose parvovirus (GPV) was sequenced and cloned into the pBluescript II (SK) plasmid vector. Sequence alignments of the inverted terminal repeats (ITR) of GPV strains revealed a common 14-nt-pair deletion in the stem of the palindromic structure in the LH strain and three other strains isolated after 1982 when compared to three GPV strains isolated earlier than that time. Transfection of 11-day-old embryonated goose eggs with the plasmid pLH, which contains the entire genome of strain LH, resulted in successful rescue of the infectious virus. Death of embryos after transfection via the chorioallantoic membrane infiltration route occurred earlier than when transfection was done via the allantoic cavity inoculation route. The rescued virus exhibited virulence similar to that of its parental virus, as evaluated by the mortality rate in goslings. Generation of the pathogenic infectious clone provides us with a powerful tool to elucidate the molecular pathogenesis of GPV in the future.

  13. Nocturnal Urinary Excretion of FSH and LH in Children and Adolescents With Normal and Early Puberty.

    Science.gov (United States)

    Kolby, Nanna; Busch, Alexander S; Aksglaede, Lise; Sørensen, Kaspar; Petersen, Jorgen Holm; Andersson, Anna-Maria; Juul, Anders

    2017-10-01

    Clinical use of single serum gonadotropin measurements in children is limited by the pulsatile secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). However, first morning voided (FMV) urine may integrate the fluctuating gonadotropin serum levels. We aimed to evaluate urinary and serum gonadotropin levels according to age, sex, and pubertal stage in healthy children and to assess the clinical use of FMV urinary gonadotropins in children with disordered puberty. Cross-sectional part of the COPENHAGEN Puberty Study and longitudinal study of patients. Population-based and outpatient clinic. Eight hundred forty-three healthy children from the COPENHAGEN Puberty Study and 25 girls evaluated for central precocious puberty (CPP). Clinical pubertal staging, including serum and urinary gonadotropin levels. Urinary gonadotropins increased with advancing age and pubertal development and were detectable in FMV urine before physical signs of puberty. FMV urinary LH correlated strongly with basal (r = 0.871, P 5 IU/L). Urinary concentrations of LH decreased after 3 months of GnRH treatment to levels below +2 SDs. Urinary gonadotropin levels increased before the onset of puberty and were elevated in girls with CPP. We suggest urinary LH as an alternative noninvasive method to improve diagnosing and therapeutic management of children with disordered puberty. Copyright © 2017 Endocrine Society

  14. L-H transition in the mega-Amp spherical tokamak

    DEFF Research Database (Denmark)

    Akers, R.J.; Counsell, G.F.; Sykes, A.

    2002-01-01

    H-mode plasmas have been achieved on the MAST spherical tokamak at input power considerably higher than predicted by conventional threshold scalings. Following L-H transition, a clear improvement in energy confinement is obtained, exceeding recent international scalings even at densities approach...

  15. Quiet Periods in Edge Turbulence Preceding the L-H Transition in NSTX

    International Nuclear Information System (INIS)

    Zweben, S.; Maqueda, R.J.; Hager, R.; Hallatschek, K.; Kaye, S.M.; Munsat, T.; Poli, F.M.; Roquemore, A.L.; Sechrest, Y.; Stotler, D.P.

    2010-01-01

    This paper describes the first observations in NSTX of 'quiet periods' in the edge turbulence preceding the L-H transition, as diagnosed by the GPI diagnostic near the outer midplane separatrix. During these quiet periods the GPI D light emission pattern was transiently similar to that seen during Hmode, i.e. with a relatively small fraction of the GPI light emission located outside the separatrix. These quiet periods had a frequency of ∼3 kHz for at least 30 msec before the L-H transition, and were correlated with changes in the direction of the local poloidal velocity. The GPI turbulence images were also analyzed to obtain an estimate for the dimensionless poloidal shearing S =(dVp/dr)(Lr/Lp). The values of S were strongly modulated by the quiet periods, but not otherwise varying for at least 30 msec preceding the L-H transition. Since neither the quiet periods nor the shear flow increased significantly immediately preceding the L-H transition, neither of these appears to be the trigger for this transition, at least for these cases in NSTX.

  16. Modeling of LH current drive in self-consistent elongated tokamak MHD equilibria

    International Nuclear Information System (INIS)

    Blackfield, D.T.; Devoto, R.S.; Fenstermacher, M.E.; Bonoli, P.T.; Porkolab, M.; Yugo, J.

    1989-01-01

    Calculations of non-inductive current drive typically have been used with model MHD equilibria which are independently generated from an assumed toroidal current profile or from a fit to an experiment. Such a method can lead to serious errors since the driven current can dramatically alter the equilibrium and changes in the equilibrium B-fields can dramatically alter the current drive. The latter effect is quite pronounced in LH current drive where the ray trajectories are sensitive to the local values of the magnetic shear and the density gradient. In order to overcome these problems, we have modified a LH simulation code to accommodate elongated plasmas with numerically generated equilibria. The new LH module has been added to the ACCOME code which solves for current drive by neutral beams, electric fields, and bootstrap effects in a self-consistent 2-D equilibrium. We briefly describe the model in the next section and then present results of a study of LH current drive in ITER. 2 refs., 6 figs., 2 tabs

  17. Possible applications of RIA of LH and FSH in diagnosis of Stein-Leventhal syndrome

    International Nuclear Information System (INIS)

    Zenisek, L.; Talas, M.; Stehlikova, J.; Fingerova, H.; Duskova, M.

    1981-01-01

    LH determination in the serum significantly assists in diagnosing polycystic ovaries. Values exceeding 22 mIU/ml serum are indicative of a typical picture of polycystic ovaries similar to those found in the Stein-Leventhal syndrome. Lower levels indicate an atypical picture of polycystic ovaries or low-cyst ovary degeneration. FSH level cannot be used for this diagnosis. (author)

  18. Dynamics of Exciton Relaxation in LH2 Antenna Probed by Multipulse Nonlinear Spectroscopy

    NARCIS (Netherlands)

    Novoderezhkin, V.I.; Cohen Stuart, T.A.; van Grondelle, R.

    2011-01-01

    We explain the relaxation dynamics in the LH2-B850 antenna as revealed by multipulse pump - dump - probe spectroscopy (Th. A. Cohen StuartM. VengrisV. I. NovoderezhkinR. J. CogdellC. N. HunterR. van Grondelle, submitted). The theory of pump - dump - probe response is evaluated using the doorway -

  19. Solid propellant ignition motors for LH_2/LOX rocket engine system

    OpenAIRE

    ARAKI, Tetsuo; AKIBA, Ryojiro; HASHIMOTO, Yasunari; AIHARA, Kenji; TOMITA, Etsu; YASUDA, Seiichi; 荒木, 哲夫; 秋葉, 鐐二郎; 橋本, 保成; 相原, 賢二; 富田, 悦; 安田, 誠一

    1983-01-01

    Solid propellant ignition motors are used in the series of experiments of the 10 ton LH_2/LOX engine featured by the channel wall thrust chamber, This paper presents design specification, experiments and results obtained by actual applications of those ignition motors.

  20. Dynamics of L-H transition and I-phase in EAST

    DEFF Research Database (Denmark)

    Xu, G. S.; Wang, H. Q.; Xu, M.

    2014-01-01

    The turbulence and flows at the plasma edge during the L-I-H, L-I-L and single-step L-H transitions have been measured directly using two reciprocating Langmuir probe systems at the outer midplane with several newly designed probe arrays in the EAST superconducting tokamak. The E × B velocity, tu...

  1. Possible applications of RIA of LH and FSH in diagnosis of Stein-Leventhal syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Zenisek, L.; Talas, M.; Stehlikova, J.; Fingerova, H.; Duskova, M.

    1981-01-01

    LH determination in the serum significantly assists in diagnosing polycystic ovaries. Values exceeding 22 mIU/ml serum are indicative of a typical picture of polycystic ovaries similar to those found in the Stein-Leventhal syndrome. Lower levels indicate an atypical picture of polycystic ovaries or low-cyst ovary degeneration. FSH level cannot be used for this diagnosis.

  2. Potential Hydrodynamic Loads on Coastal Bridges in the Greater New York Area due to Extreme Storm Surge and Wave

    Science.gov (United States)

    2018-04-18

    This project makes a computer modeling study on vulnerability of coastal bridges in New York City (NYC) metropolitan region to storm surges and waves. Prediction is made for potential surges and waves in the region and consequent hydrodynamic load an...

  3. Regional and temporal differences in gene expression of LH(BETA)T(AG) retinoblastoma tumors.

    Science.gov (United States)

    Houston, Samuel K; Pina, Yolanda; Clarke, Jennifer; Koru-Sengul, Tulay; Scott, William K; Nathanson, Lubov; Schefler, Amy C; Murray, Timothy G

    2011-07-23

    The purpose of this study was to evaluate by microarray the hypothesis that LH(BETA)T(AG) retinoblastoma tumors exhibit regional and temporal variations in gene expression. LH(BETA)T(AG) mice aged 12, 16, and 20 weeks were euthanatized (n = 9). Specimens were taken from five tumor areas (apex, anterior lateral, center, base, and posterior lateral). Samples were hybridized to gene microarrays. The data were preprocessed and analyzed, and genes with a P 2.5 were considered to be differentially expressed. Differentially expressed genes were analyzed for overlap with known networks by using pathway analysis tools. There were significant temporal (P regional differences in gene expression for LH(BETA)T(AG) retinoblastoma tumors. At P 2.5, there were significant changes in gene expression of 190 genes apically, 84 genes anterolaterally, 126 genes posteriorly, 56 genes centrally, and 134 genes at the base. Differentially expressed genes overlapped with known networks, with significant involvement in regulation of cellular proliferation and growth, response to oxygen levels and hypoxia, regulation of cellular processes, cellular signaling cascades, and angiogenesis. There are significant temporal and regional variations in the LH(BETA)T(AG) retinoblastoma model. Differentially expressed genes overlap with key pathways that may play pivotal roles in murine retinoblastoma development. These findings suggest the mechanisms involved in tumor growth and progression in murine retinoblastoma tumors and identify pathways for analysis at a functional level, to determine significance in human retinoblastoma. Microarray analysis of LH(BETA)T(AG) retinal tumors showed significant regional and temporal variations in gene expression, including dysregulation of genes involved in hypoxic responses and angiogenesis.

  4. Production of specific antisera for radioimmunoassay of human luteinizing hormone (LH) in the presence of human chorionic gonadotropin (hCG)

    International Nuclear Information System (INIS)

    Thorell, J.I.; Jeppsson, S.; Holmstrom, B.

    1976-01-01

    A specific radioimmunoassay for LH, which measures plasma LH in the presence of human chorionic gonadotropin (hCG) is described. Rabbits were immunized with highly purified native LH. One of the antisera with a difference in its reactivity against LH and hCG was further purified by affinity chromatography on a column with hCG coupled to Sepharose 4B. The adsorbed antiserum and 125 I-LH was used in a double antibody assay. The LH standard (MRC/68/40) efficiently inhibited the binding of 125 I-LH, and the standard curve showed a sensitivity of 0.5 ng/ml in the sample. hCG up to 10,000 ng/ml did not inhibit the binding of 125 I-LH. The plasma level of LH in pregnant women in the first trimester was low (1.3 +- 0.1 ng/ml). When LH was measured in fertile or menopausal women with or without stimulation with LH/FSH releasing hormone (LH-RH)/sup x/ the results agreed to those found with our conventional LH-assay based on antiserum against hCG

  5. Neuroanatomical organization of gonadotropin-releasing hormone neurons during the oestrus cycle in the ewe

    Science.gov (United States)

    Batailler, Martine; Caraty, Alain; Malpaux, Benoît; Tillet, Yves

    2004-01-01

    Background During the preovulatory surge of gonadotropin-releasing hormone (GnRH), a very large amount of the peptide is released in the hypothalamo-hypophyseal portal blood for 24-36H00. To study whether this release is linked to a modification of the morphological organization of the GnRH-containing neurons, i.e. morphological plasticity, we conducted experiments in intact ewes at 4 different times of the oestrous cycle (before the expected LH surge, during the LH surge, and on day 8 and day 15 of the subsequent luteal phase). The cycle stage was verified by determination of progesterone and LH concentrations in the peripheral blood samples collected prior to euthanasia. Results The distribution of GnRH-containing neurons throughout the preoptic area around the vascular organ of the lamina terminalis was studied following visualisation using immunohistochemistry. No difference was observed in the staining intensity for GnRH between the different groups. Clusters of GnRH-containing neurons (defined as 2 or more neurons being observed in close contact) were more numerous during the late follicular phase (43 ± 7) than during the luteal phase (25 ± 6), and the percentage of clusters was higher during the beginning of the follicular phase than during the luteal phase. There was no difference in the number of labelled neurons in each group. Conclusions These results indicate that the morphological organization of the GnRH-containing neurons in ewes is modified during the follicular phase. This transitory re-organization may contribute to the putative synchronization of these neurons during the surge. The molecular signal inducing this plasticity has not yet been identified, but oestradiol might play an important role, since in sheep it is the only signal which initiates the GnRH preovulatory surge. PMID:15555074

  6. Neuroanatomical organization of gonadotropin-releasing hormone neurons during the oestrus cycle in the ewe

    Directory of Open Access Journals (Sweden)

    Malpaux Benoît

    2004-11-01

    Full Text Available Abstract Background During the preovulatory surge of gonadotropin-releasing hormone (GnRH, a very large amount of the peptide is released in the hypothalamo-hypophyseal portal blood for 24-36H00. To study whether this release is linked to a modification of the morphological organization of the GnRH-containing neurons, i.e. morphological plasticity, we conducted experiments in intact ewes at 4 different times of the oestrous cycle (before the expected LH surge, during the LH surge, and on day 8 and day 15 of the subsequent luteal phase. The cycle stage was verified by determination of progesterone and LH concentrations in the peripheral blood samples collected prior to euthanasia. Results The distribution of GnRH-containing neurons throughout the preoptic area around the vascular organ of the lamina terminalis was studied following visualisation using immunohistochemistry. No difference was observed in the staining intensity for GnRH between the different groups. Clusters of GnRH-containing neurons (defined as 2 or more neurons being observed in close contact were more numerous during the late follicular phase (43 ± 7 than during the luteal phase (25 ± 6, and the percentage of clusters was higher during the beginning of the follicular phase than during the luteal phase. There was no difference in the number of labelled neurons in each group. Conclusions These results indicate that the morphological organization of the GnRH-containing neurons in ewes is modified during the follicular phase. This transitory re-organization may contribute to the putative synchronization of these neurons during the surge. The molecular signal inducing this plasticity has not yet been identified, but oestradiol might play an important role, since in sheep it is the only signal which initiates the GnRH preovulatory surge.

  7. Observed characteristics of tide-surge interaction along the east coast of India and the head of Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, C.; Unnikrishnan, A.S.

    before the high tide. Application of a simple model shows the observed surge peak distribution at Hiron Point can be explained in terms of phase alteration of tide due to surge and surge modulation by tide. The degree of interaction tends to increase...

  8. Predicting Typhoon Induced Storm Surges Using the Operational Ocean Forecast System

    Directory of Open Access Journals (Sweden)

    Sung Hyup You

    2010-01-01

    Full Text Available This study was performed to compare storm surges simulated by the operational storm surges/tide forecast system (STORM : Storm surges/Tide Operational Model of the Korea Meteorological Administration (KMA with observations from 30 coastal tidal stations during nine typhoons that occurred between 2005 and 2007. The results (bias showed that for cases of overestimation (or underestimation, storm surges tended to be overestimated (as well as underestimated at all coastal stations. The maximum positive bias was approximately 6.92 cm for Typhoon Ewiniar (2006, while the maximum negative bias was approximately -12.06 cm for Typhoon Khanun (2005. The maximum and minimum root mean square errors (RMSEs were 14.61 and 6.78 cm, which occurred for Typhoons Khanun (2005 and Usagi (2007, respectively. For all nine typhoons, total averaged RMSE was approximately 10.2 cm. Large differences between modeled and observed storm surges occurred in two cases. In the first, a very weak typhoon, such as Typhoon Khanun (2005, caused low storm surges. In the other, exemplified by Typhoon Nari (2007, there were errors in the predicted typhoon strength used as input data for the storm surge model.

  9. Simulating Storm Surge Impacts with a Coupled Atmosphere-Inundation Model with Varying Meteorological Forcing

    Directory of Open Access Journals (Sweden)

    Alexandra N. Ramos Valle

    2018-04-01

    Full Text Available Storm surge events have the potential to cause devastating damage to coastal communities. The magnitude of their impacts highlights the need for increased accuracy and real-time forecasting and predictability of storm surge. In this study, we assess two meteorological forcing configurations to hindcast the storm surge of Hurricane Sandy, and ultimately support the improvement of storm surge forecasts. The Weather Research and Forecasting (WRF model is coupled to the ADvanced CIRCulation Model (ADCIRC to determine water elevations. We perform four coupled simulations and compare storm surge estimates resulting from the use of a parametric vortex model and a full-physics atmospheric model. One simulation is forced with track-based meteorological data calculated from WRF, while three simulations are forced with the full wind and pressure field outputs from WRF simulations of varying resolutions. Experiments were compared to an ADCIRC simulation forced by National Hurricane Center best track data, as well as to station observations. Our results indicated that given accurate meteorological best track data, a parametric vortex model can accurately forecast maximum water elevations, improving upon the use of a full-physics coupled atmospheric-surge model. In the absence of a best track, atmospheric forcing in the form of full wind and pressure field from a high-resolution atmospheric model simulation prove reliable for storm surge forecasting.

  10. Surge analysis of the MAGLEV coil for propulsion and guidance; Jiki fujoshiki tetsudo ni okeru suitei annaiyo coil no surge kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Ema, S [Numazu College of Technology, Shizuoka (Japan)

    1995-11-20

    The MAGLEV (magnetically levitated train) is now well along in development testing in Japan. MAGLEV is unlike conventional railways, so various problems lie in the technology of MAGLEV. One of them is surge analysis of the MAGLEV coil for propulsion and guidance (`coil for propulsion` for short). The coil for propulsion is installed on each side of the outdoor guideway. Thus, the power system of MAGLEV is always exposed to lightning and circuit switching. Accordingly, it is very important to do a rational insulation plan to prevent damage when surges enter the coils. In view of this situation I performed experiments using the mini model coils and clarified impulse voltage distribution at the end of each coil and simulated the surge characteristics by giving the inverted L equivalent circuit to the coil for propulsion. As a result, the measured values and calculated values were almost equal in the surge characteristics. Further, the surge characteristics of the Miyazaki test track and the future MAGLEV were examined. 10 refs., 17 figs., 1 tab.

  11. Developing an early warning system for storm surge inundation in the Philippines

    Science.gov (United States)

    Tablazon, J.; Caro, C. V.; Lagmay, A. M. F.; Briones, J. B. L.; Dasallas, L.; Lapidez, J. P.; Santiago, J.; Suarez, J. K.; Ladiero, C.; Gonzalo, L. A.; Mungcal, M. T. F.; Malano, V.

    2014-10-01

    A storm surge is the sudden rise of sea water generated by an approaching storm, over and above the astronomical tides. This event imposes a major threat in the Philippine coastal areas, as manifested by Typhoon Haiyan on 8 November 2013 where more than 6000 people lost their lives. It has become evident that the need to develop an early warning system for storm surges is of utmost importance. To provide forecasts of the possible storm surge heights of an approaching typhoon, the Nationwide Operational Assessment of Hazards under the Department of Science and Technology (DOST-Project NOAH) simulated historical tropical cyclones that entered the Philippine Area of Responsibility. Bathymetric data, storm track, central atmospheric pressure, and maximum wind speed were used as parameters for the Japan Meteorological Agency Storm Surge Model. The researchers calculated the frequency distribution of maximum storm surge heights of all typhoons under a specific Public Storm Warning Signal (PSWS) that passed through a particular coastal area. This determines the storm surge height corresponding to a given probability of occurrence. The storm surge heights from the model were added to the maximum astronomical tide data from WXTide software. The team then created maps of probable area inundation and flood levels of storm surges along coastal areas for a specific PSWS using the results of the frequency distribution. These maps were developed from the time series data of the storm tide at 10 min intervals of all observation points in the Philippines. This information will be beneficial in developing early warnings systems, static maps, disaster mitigation and preparedness plans, vulnerability assessments, risk-sensitive land use plans, shoreline defense efforts, and coastal protection measures. Moreover, these will support the local government units' mandate to raise public awareness, disseminate information about storm surge hazards, and implement appropriate counter

  12. Flexibility and size heterogeneity of the LH1 light harvesting complex revealed by atomic force microscopy - Functional significance for bacterial photosynthesis

    NARCIS (Netherlands)

    Bahatyrova, S.; Frese, R.N.; van der Werf, K.O.; Otto, C.; Hunter, C.N.; Olsen, J.D.

    2004-01-01

    Previous electron microscopic studies of bacterial RC-LH1 complexes demonstrated both circular and elliptical conformations of the LH1 ring, and this implied flexibility has been suggested to allow passage of quinol from the Q

  13. Dynamics of energy transfer from lycopene to bacteriochlorophyll in genetically-modified LH2 complexes of Rhodobacter sphaeroides.

    Science.gov (United States)

    Hörvin Billsten, H; Herek, J L; Garcia-Asua, G; Hashøj, L; Polívka, T; Hunter, C N; Sundström, V

    2002-03-26

    LH2 complexes from Rb. sphaeroides were modified genetically so that lycopene, with 11 saturated double bonds, replaced the native carotenoids which contain 10 saturated double bonds. Tuning the S1 level of the carotenoid in LH2 in this way affected the dynamics of energy transfer within LH2, which were investigated using both steady-state and time-resolved techniques. The S1 energy of lycopene in n-hexane was determined to be approximately 12 500 +/- 150 cm(-1), by direct measurement of the S1-S2 transient absorption spectrum using a femtosecond IR-probing technique, thus placing an upper limit on the S1 energy of lycopene in the LH2 complex. Fluorescence emission and excitation spectra demonstrated that energy can be transferred from lycopene to the bacteriochlorophyll molecules within this LH2 complex. The energy-transfer dynamics within the mutant complex were compared to wild-type LH2 from Rb. sphaeroides containing the carotenoid spheroidene and from Rs. molischianum, in which lycopene is the native carotenoid. The results show that the overall efficiency for Crt --> B850 energy transfer is approximately 80% in lyco-LH2 and approximately 95% in WT-LH2 of Rb. sphaeroides. The difference in overall Crt --> BChl transfer efficiency of lyco-LH2 and WT-LH2 mainly relates to the low efficiency of the Crt S(1) --> BChl pathway for complexes containing lycopene, which was 20% in lyco-LH2. These results show that in an LH2 complex where the Crt S1 energy is sufficiently high to provide efficient spectral overlap with both B800 and B850 Q(y) states, energy transfer via the Crt S1 state occurs to both pigments. However, the introduction of lycopene into the Rb. sphaeroides LH2 complex lowers the S1 level of the carotenoid sufficiently to prevent efficient transfer of energy to the B800 Q(y) state, leaving only the Crt S1 --> B850 channel, strongly suggesting that Crt S1 --> BChl energy transfer is controlled by the relative Crt S1 and BChl Q(y) energies.

  14. The third oil price surge. What's different this time?

    International Nuclear Information System (INIS)

    Kesicki, Fabian

    2010-01-01

    The period from 2003 to 2008 was marked by an oil price increase comparable to the two oil price crises in the 1970s. This paper looks in detail at the situation of the oil price crises 30 years ago and compares them along various aspects on the demand and supply side with the recent price increase to identify similarities and differences. While both oil price crises in 1973 and 1979/1980 were ultimately caused by supply actions of members of the Organisation of Petroleum Exporting Countries (OPEC), all three oil price crises were preceded by high demand growth. Other aspects that favoured a high oil price in all three cases were low investments in new oil fields, as a consequence low spare capacity, and a weak US dollar. In addition, the recent oil price surge has been characterised by a high global refinery utilisation and refineries that did not adapt fast enough to the rising demand for lighter oil products. Moreover, broader geopolitical uncertainties, combined with risks associated with the oil trade helped push the oil price into a triple-digit zone. Speculation played only a limited and temporary role in accelerating price movements during the recent price increase. (author)

  15. Smart Ultrasound Remote Guidance Experiment (SURGE) Preliminary Findings

    Science.gov (United States)

    Hurst, Victor; Dulchavsky, Scott; Garcia, Kathleen; Sargsyan, Ashot; Ebert, Doug

    2009-01-01

    To date, diagnostic quality ultrasound images were obtained aboard the International Space Station (ISS) using the ultrasound of the Human Research Facility (HRF) rack in the Laboratory module. Through the Advanced Diagnostic Ultrasound in Microgravity (ADUM) and the Braslet-M Occlusion Cuffs (BRASLET SDTO) studies, non-expert ultrasound operators aboard the ISS have performed cardiac, thoracic, abdominal, vascular, ocular, and musculoskeletal ultrasound assessments using remote guidance from ground-based ultrasound experts. With exploration class missions to the lunar and Martian surfaces on the horizon, crew medical officers will necessarily need to operate with greater autonomy given communication delays (round trip times of up to 5 seconds for the Moon and 90 minutes for Mars) and longer periods of communication blackouts (due to orbital constraints of communication assets). The SURGE project explored the feasibility and training requirements of having non-expert ultrasound operators perform autonomous ultrasound assessments in a simulated exploration mission outpost. The project aimed to identify experience, training, and human factors requirements for crew medical officers to perform autonomous ultrasonography. All of these aims pertained to the following risks from the NASA Bioastronautics Road Map: 1) Risk 18: Major Illness and Trauna; 2) Risk 20) Ambulatory Care; 3) Risk 22: Medical Informatics, Technologies, and Support Systems; and 4) Risk 23: Medical Skill Training and Maintenance.

  16. Lightning and surge protection of large ground facilities

    Science.gov (United States)

    Stringfellow, Michael F.

    1988-04-01

    The vulnerability of large ground facilities to direct lightning strikes and to lightning-induced overvoltages on the power distribution, telephone and data communication lines are discussed. Advanced electrogeometric modeling is used for the calculation of direct strikes to overhead power lines, buildings, vehicles and objects within the facility. Possible modes of damage, injury and loss are discussed. Some appropriate protection methods for overhead power lines, structures, vehicles and aircraft are suggested. Methods to mitigate the effects of transients on overhead and underground power systems as well as within buildings and other structures are recommended. The specification and location of low-voltage surge suppressors for the protection of vulnerable hardware such as computers, telecommunication equipment and radar installations are considered. The advantages and disadvantages of commonly used grounding techniques, such as single point, multiple and isolated grounds are compared. An example is given of the expected distribution of lightning flashes to a large airport, its buildings, structures and facilities, as well as to vehicles on the ground.

  17. The celiac ganglion modulates LH-induced inhibition of androstenedione release in late pregnant rat ovaries

    Directory of Open Access Journals (Sweden)

    Rastrilla Ana M

    2006-12-01

    Full Text Available Abstract Background Although the control of ovarian production of steroid hormones is mainly of endocrine nature, there is increasing evidence that the nervous system also influences ovarian steroidogenic output. The purpose of this work was to study whether the celiac ganglion modulates, via the superior ovarian nerve, the anti-steroidogenic effect of LH in the rat ovary. Using mid- and late-pregnant rats, we set up to study: 1 the influence of the noradrenergic stimulation of the celiac ganglion on the ovarian production of the luteotropic hormone androstenedione; 2 the modulatory effect of noradrenaline at the celiac ganglion on the anti-steroidogenic effect of LH in the ovary; and 3 the involvement of catecholaminergic neurotransmitters released in the ovary upon the combination of noradrenergic stimulation of the celiac ganglion and LH treatment of the ovary. Methods The ex vivo celiac ganglion-superior ovarian nerve-ovary integrated system was used. This model allows studying in vitro how direct neural connections from the celiac ganglion regulate ovarian steroidogenic output. The system was incubated in buffer solution with the ganglion and the ovary located in different compartments and linked by the superior ovarian nerve. Three experiments were designed with the addition of: 1 noradrenaline in the ganglion compartment; 2 LH in the ovarian compartment; and 3 noradrenaline and LH in the ganglion and ovarian compartments, respectively. Rats of 15, 19, 20 and 21 days of pregnancy were used, and, as an end point, the concentration of the luteotropic hormone androstenedione was measured in the ovarian compartment by RIA at various times of incubation. For some of the experimental paradigms the concentration of various catecholamines (dihydroxyphenylalanine, dopamine, noradrenaline and adrenaline was also measured in the ovarian compartment by HPLC. Results The most relevant result concerning the action of noradrenaline in the celiac ganglion

  18. The Danger of Deja Vu: Why the Iraq Surge is Not a Lesson for Afghanistan

    Science.gov (United States)

    2010-01-01

    JAN 2010 2. REPORT TYPE 3. DATES COVERED 00-12-2009 to 00-01-2010 4. TITLE AND SUBTITLE The danger of deja vu . Why the Iraq surge is not a lesson...of five brigade combat teams — eerily mim- icked the surge number for Iraq. And there was more déjà vu when our senior civilian and military leaders...Department. PERSPECTIVES The danger of déjà vu Why the Iraq surge is not a lesson for Afghanistan BY COL. CHARLES D. ALLEN (RET.) The thing we take hold of

  19. A Basis Function Approach to Simulate Storm Surge Events for Coastal Flood Risk Assessment

    Science.gov (United States)

    Wu, Wenyan; Westra, Seth; Leonard, Michael

    2017-04-01

    Storm surge is a significant contributor to flooding in coastal and estuarine regions, especially when it coincides with other flood producing mechanisms, such as extreme rainfall. Therefore, storm surge has always been a research focus in coastal flood risk assessment. Often numerical models have been developed to understand storm surge events for risk assessment (Kumagai et al. 2016; Li et al. 2016; Zhang et al. 2016) (Bastidas et al. 2016; Bilskie et al. 2016; Dalledonne and Mayerle 2016; Haigh et al. 2014; Kodaira et al. 2016; Lapetina and Sheng 2015), and assess how these events may change or evolve in the future (Izuru et al. 2015; Oey and Chou 2016). However, numeric models often require a lot of input information and difficulties arise when there are not sufficient data available (Madsen et al. 2015). Alternative, statistical methods have been used to forecast storm surge based on historical data (Hashemi et al. 2016; Kim et al. 2016) or to examine the long term trend in the change of storm surge events, especially under climate change (Balaguru et al. 2016; Oh et al. 2016; Rueda et al. 2016). In these studies, often the peak of surge events is used, which result in the loss of dynamic information within a tidal cycle or surge event (i.e. a time series of storm surge values). In this study, we propose an alternative basis function (BF) based approach to examine the different attributes (e.g. peak and durations) of storm surge events using historical data. Two simple two-parameter BFs were used: the exponential function and the triangular function. High quality hourly storm surge record from 15 tide gauges around Australia were examined. It was found that there are significantly location and seasonal variability in the peak and duration of storm surge events, which provides additional insights in coastal flood risk. In addition, the simple form of these BFs allows fast simulation of storm surge events and minimises the complexity of joint probability

  20. Self diffusion and spectral modifications of a membrane protein, the Rubrivivax gelatinosus LH2 complex, incorporated into a monoolein cubic phase.

    OpenAIRE

    Tsapis, N; Reiss-Husson, F; Ober, R; Genest, M; Hodges, R S; Urbach, W

    2001-01-01

    The light-harvesting complex LH2 from a purple bacterium, Rubrivivax gelatinosus, has been incorporated into the Q230 cubic phase of monoolein. We measured the self-diffusion of LH2 in detergent solution and in the cubic phase by fluorescence recovery after photobleaching. We investigated also the absorption and fluorescence properties of this oligomeric membrane protein in the cubic phase, in comparison with its beta-octyl glucoside solution. In these experiments, native LH2 and LH2 labeled ...

  1. The electronically excited states of LH2 complexes from Rhodopseudomonas acidophila strain 10050 studied by time-resolved spectroscopy and dynamic Monte Carlo simulations. II. Homo-arrays of LH2 complexes reconstituted into phospholipid model membranes.

    Science.gov (United States)

    Pflock, Tobias J; Oellerich, Silke; Krapf, Lisa; Southall, June; Cogdell, Richard J; Ullmann, G Matthias; Köhler, Jürgen

    2011-07-21

    We performed time-resolved spectroscopy on homoarrays of LH2 complexes from the photosynthetic purple bacterium Rhodopseudomonas acidophila. Variations of the fluorescence transients were monitored as a function of the excitation fluence and the repetition rate of the excitation. These parameters are directly related to the excitation density within the array and to the number of LH2 complexes that still carry a triplet state prior to the next excitation. Comparison of the experimental observations with results from dynamic Monte Carlo simulations for a model cluster of LH2 complexes yields qualitative agreement without the need for any free parameter and reveals the mutual relationship between energy transfer and annihilation processes.

  2. Identification of the upper exciton component of the B850 bacteriochlorophylls of the LH2 antenna complex, using a B800-free mutant of Rhodobacter sphaeroides.

    NARCIS (Netherlands)

    Koolhaas, M.H.C.; Frese, R.N.; Fowler, G.J.S.; Bibby, T.S.; Georgakopoulou, S.; van der Zwan, G.; Hunter, C.N.; van Grondelle, R.

    1998-01-01

    In this paper, we report the circular dichroism (CD) spectra of two types of LH2 -only mutants of Rhodobacter sphaeroides. In the first, only the wild type LH2 is present, while in the second, the B800 binding site of LH2 has been either destabilized or removed. For the first time, we have

  3. PENGARUH PEMBERIAN MONOSODIUM GLUTAMAT (MSG PADA TIKUS JANTAN (Rattus Norvegicus TERHADAP FSH DAN LH

    Directory of Open Access Journals (Sweden)

    Zulkarnain Edward

    2010-09-01

    Full Text Available AbstrakKemajuan teknologi informasi membawa dampak terhadap perubahan gaya hidup masyarakat, termasuk perubahan pola konsumsi makanan yang lebih banyak mengkonsumsi jenis makanan cepat saji, makanan kemasan dan makanan awetan yang belakangan ini semakin banyak dijual dipasar tradisional dan swalayan. Penggunaan bahan tambahan makanan sering dijumpai, salah satunya adalah bahan penyedap yang banyak sekali digunakan seperti senyawa L-asam glutamat yang digunakan dalam bentuk garam yaitu monosodium glutamat (MSG. Berbagai merk dagang MSG telah dikenal dimasyarakat secara luas seperti ajinomoto, vetsin, micin, sasa, miwon dan sebagainya.MSG adalah garam monosodium dengan asam glutamat yang sering digunakan sebagai bahan penyedap masakan untuk merangsang selera makan. Pemberian MSG mengakibatkan gangguan hormonal pada hewan coba, ion glutamat dalam sirkulasi portal akan mempengaruhi hipotalamus dalam memproduksi GnRH yang selanjutnya akan mengganggu hipofise anterior dalam memproduksi FSH dan LH. Fungsi FSH adalah untuk bekerja pada tubulus seminiferus terutama pada sel sertoli untuk meningkatkan spermatogenesis, sedangkan LH berfungsi pada sel Leydig untuk mengatur sekresi testosteron.Penelitian ini bersifat eksperimen dengan rancangan post only group design. Penelitian dilakukan di laboratorium Biologi dan laboratorium Biokimia Fakultas Kedokteran Unand Padang dari tanggal 20 Desember 2009 sampai 30 Februari 2010. Populasi adalah tikus putih jantan strain Jepang (Rattus norvegicus yang berasal dari laboratorium Fakultas Matematika dan Ilmu Pengetahuan Alam Unand. Sampel berjumlah 20 ekor dibagi atas 4 kelompok dengan satu kelompok kontrol dan tiga kelompok perlakuan. Dosis MSG yang digunakan yaitu P1= 4800 mg/kgbb/hari, P2=7200 mg/kgbb/hari dan P3= 9600 mg/kgbb/hari diberikan peroral sebanyak dua siklus epitel seminiferus. Analisa dengan uji Anova dengan derajat kepercayaan 95% dan jika bermakna dilanjutkan dengan uji Multiple Comparissons jenis

  4. Identification of Storm Surge Vulnerable Areas in the Philippines Through Simulations of Typhoon Haiyan-Induced Storm Surge Using Tracks of Historical Tropical Cyclones

    Science.gov (United States)

    Lapidez, John Phillip; Suarez, John Kenneth; Tablazon, Judd; Dasallas, Lea; Gonzalo, Lia Anne; Santiago, Joy; Cabacaba, Krichi May; Ramos, Michael Marie Angelo; Mahar Francisco Lagmay, Alfredo; Malano, Vicente

    2014-05-01

    Super Typhoon Haiyan entered the Philippine Area of Responsibility (PAR) 07 November 2013, causing tremendous damage to infrastructure and loss of lives mainly due to the typhoon's storm surge and strong winds. Storm surges up to a height of 7 meters were reported in the hardest hit areas. The threat imposed by this kind of natural calamity compelled researchers of the Nationwide Operational Assessment of Hazards, the flagship disaster mitigation program of the Department of Science and Technology, Government of the Philippines, to undertake a study to determine the vulnerability of all Philippine coastal communities to storm surges of the same magnitude as those generated by Haiyan. This study calculates the maximum probable storm surge height for every coastal locality by running simulations of Haiyan-type conditions but with tracks of tropical cyclones that entered PAR from 1948-2013. DOST-Project NOAH used the Japan Meteorological Agency (JMA) Storm Surge Model, a numerical code that simulates and predicts storm surges spawned by tropical cyclones. Input parameters for the storm surge model include bathymetric data, storm track, central atmospheric pressure, and maximum wind speed. The simulations were made using Haiyan's pressure and wind speed as the forcing parameters. The simulated storm surge height values were added to the maximum tide level obtained from WXTide, software that contains a catalogue of worldwide astronomical tides, to come up with storm tide levels. The resulting water level was used as input to FLO-2D to generate the storm tide inundation maps. One product of this study is a list of the most vulnerable coastal areas that can be used as basis for choosing priority sites for further studies to implement appropriate site-specific solutions. Another product is the storm tide inundation maps that the local government units can use to develop a Risk-Sensitive Land Use Plan for identifying appropriate areas to build residential buildings

  5. Criteria for the Identification of Pyroclastic Surge Deposits on Mars: Insight from Hunt's Hole, New Mexico

    Science.gov (United States)

    Edgar, L. A.; Grotzinger, J. P.; Southard, J. B.; Ewing, R. C.; Lamb, M. P.

    2012-03-01

    We combine field observations, Terrestrial Laser Scanning (TLS), and hydrodynamic considerations to understand pyroclastic surge deposits at Hunt’s Hole, New Mexico, and provide criteria for their identification on Mars.

  6. Three-Dimensional Numerical Analysis of Compound Lining in Complex Underground Surge-Shaft Structure

    Directory of Open Access Journals (Sweden)

    Juntao Chen

    2015-01-01

    Full Text Available The mechanical behavior of lining structure of deep-embedded cylinder surge shaft with multifork tunnel is analyzed using three-dimensional nonlinear FEM. With the elastic-plastic constitutive relations of rock mass imported and the implicit bolt element and distributed concrete cracking model adopted, a computing method of complex surge shaft is presented for the simulation of underground excavations and concrete lining cracks. In order to reflect the interaction and initial gap between rock mass and concrete lining, a three-dimensional nonlinear interface element is adopted, which can take into account both the normal and tangential characteristics. By an actual engineering computation, the distortion characteristics and stress distribution rules of the dimensional multifork surge-shaft lining structure under different behavior are revealed. The results verify the rationality and feasibility of this computation model and method and provide a new idea and reference for the complex surge-shaft design and construction.

  7. ISSN 2073 ISSN 2073-9990 East Cent. Afr. J. surg. (Online) 9990 ...

    African Journals Online (AJOL)

    Prof Kakande

    Afr. J. surg. ..... September/October 2003. 3. Hardin R, Stevenson M, Downie W, Wilson G. Assessment of clinical competence using objective ... Michael J. Griesser, Matthew C. Beran, David C. Flanigan, Michael Quackenbush, DO, Corey Van ...

  8. Evaluation of Ferrite Chip Beads as Surge Current Limiters in Circuits with Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander

    2014-01-01

    Limiting resistors are currently required to be connected in series with tantalum capacitors to reduce the risk of surge current failures. However, application of limiting resistors decreases substantially the efficiency of the power supply systems. An ideal surge current limiting device should have a negligible resistance for DC currents and high resistance at frequencies corresponding to transients in tantalum capacitors. This work evaluates the possibility of using chip ferrite beads (FB) as such devices. Twelve types of small size FBs from three manufacturers were used to evaluate their robustness under soldering stresses and at high surge current spikes associated with transients in tantalum capacitors. Results show that FBs are capable to withstand current pulses that are substantially greater than the specified current limits. However, due to a sharp decrease of impedance with current, FBs do not reduce surge currents to the required level that can be achieved with regular resistors.

  9. MAGNETIC-RECONNECTION GENERATED SHOCK WAVES AS A DRIVER OF SOLAR SURGES

    International Nuclear Information System (INIS)

    Yang, Heesu; Chae, Jongchul; Park, Hyungmin; Song, Dong-uk; Cho, Kyuhyoun; Lim, Eun-Kyung; Lee, Kyoung-sun

    2014-01-01

    We found that a surge consists of multiple shock features. In our high-spatiotemporal spectroscopic observation of the surge, each shock is identified with the sudden appearance of an absorption feature at the blue wings of the Ca II 8542 Å line and Hα line that gradually shifts to the red wings. The shock features overlap with one another with the time interval of 110 s, which is much shorter than the duration of each shock feature, 300-400 s. This finding suggests that the multiple shocks might not have originated from a train of sinusoidal waves generated by oscillations and flows in the photosphere. As we found the signature of the magnetic flux cancelations at the base of the surge, we conclude that the multiple shock waves in charge of the surge were generated by the magnetic reconnection that occurred in the low atmosphere in association with the flux cancelation

  10. Sea, Lake, and Overland Surge from Hurricanes (SLOSH) Inundation for Categories 2 and 4

    Data.gov (United States)

    U.S. Environmental Protection Agency — The file geodatabase (fgdb) contains the Sea, Lake, and Overland Surge from Hurricanes (SLOSH) Maximum of Maximums (MOM) model for hurricane categories 2 and 4. The...

  11. Control of Surge in Centrifugal Compressors by Active Magnetic Bearings Theory and Implementation

    CERN Document Server

    Yoon, Se Young; Allaire, Paul E

    2013-01-01

    Control of Surge in Centrifugal Compressors by Active Magnetic Bearings sets out the fundamentals of integrating the active magnetic bearing (AMB) rotor suspension technology in compressor systems, and describes how this relatively new bearing technology can be employed in the active control of compressor surge. The authors provide a self-contained and comprehensive review of rotordynamics and the fundamentals of the AMB technology. The active stabilization of compressor surge employing AMBs in a machine is fully explored, from the modeling of the instability and the design of feedback controllers, to the implementation and experimental testing of the control algorithms in a specially-constructed, industrial-size centrifugal compression system. The results of these tests demonstrate the great potential of the new surge control method developed in this text. This book will be useful for engineers in industries that involve turbocompressors and magnetic bearings, as well as for researchers and graduate students...

  12. Real-Time Forecasting System of Winds, Waves and Surge in Tropical Cyclones

    National Research Council Canada - National Science Library

    Graber, Hans C; Donelan, Mark A; Brown, Michael G; Slinn, Donald N; Hagen, Scott C; Thompson, Donald R; Jensen, Robert E; Black, Peter G; Powell, Mark D; Guiney, John L

    2005-01-01

    The long-term goal of this partnership is to establish an operational forecasting system of the wind field and resulting waves and surge impacting the coastline during the approach and landfall of tropical cyclones...

  13. Real-Time Forecasting System of Winds, Waves and Surge in Tropical Cyclones

    National Research Council Canada - National Science Library

    Graber, Hans C; Donelan, Mark A; Brown, Michael G; Slinn, Donald N; Hagen, Scott C; Thompson, Donald R; Jensen, Robert E; Black, Peter G; Powell, Mark D; Guiney, John L

    2004-01-01

    The long-term goal of this partnership is to establish an operational forecasting system of the wind field and resulting waves and surge impacting the coastline during the approach and landfall of tropical cyclones...

  14. Real-Time Forecasting System of Winds, Waves and Surge in Tropical Cyclones

    National Research Council Canada - National Science Library

    Graber, Hans C; Donelan, Mark A; Brown, Michael G; Slinn, Donald N; Hagen, Scott C; Thompson, Donald R; Jensen, Robert E; Black, Peter G; Powell, Mark D; Guiney, John L; Cardone, Vincent J; Cox, Andrew T; Augustus, Ellsworth H; Colonnese, Christopher P

    2003-01-01

    The long-term goal of this partnership is to establish an operational forecasting system of the wind field and resulting waves and surge impacting the coastline during the approach and landfall of tropical cyclones...

  15. Population and coherence dynamics in light harvesting complex II (LH2).

    Science.gov (United States)

    Yeh, Shu-Hao; Zhu, Jing; Kais, Sabre

    2012-08-28

    The electronic excitation population and coherence dynamics in the chromophores of the photosynthetic light harvesting complex 2 (LH2) B850 ring from purple bacteria (Rhodopseudomonas acidophila) have been studied theoretically at both physiological and cryogenic temperatures. Similar to the well-studied Fenna-Matthews-Olson (FMO) protein, oscillations of the excitation population and coherence in the site basis are observed in LH2 by using a scaled hierarchical equation of motion approach. However, this oscillation time (300 fs) is much shorter compared to the FMO protein (650 fs) at cryogenic temperature. Both environment and high temperature are found to enhance the propagation speed of the exciton wave packet yet they shorten the coherence time and suppress the oscillation amplitude of coherence and the population. Our calculations show that a long-lived coherence between chromophore electronic excited states can exist in such a noisy biological environment.

  16. Study of fuel systems for LH2-fueled subsonic transport aircraft, volume 1

    Science.gov (United States)

    Brewer, G. D.; Morris, R. E.; Davis, G. W.; Versaw, E. F.; Cunnington, G. R., Jr.; Riple, J. C.; Baerst, C. F.; Garmong, G.

    1978-01-01

    Several engine concepts examined to determine a preferred design which most effectively exploits the characteristics of hydrogen fuel in aircraft tanks received major emphasis. Many candidate designs of tank structure and cryogenic insulation systems were evaluated. Designs of all major elements of the aircraft fuel system including pumps, lines, valves, regulators, and heat exchangers received attention. Selected designs of boost pumps to be mounted in the LH2 tanks, and of a high pressure pump to be mounted on the engine were defined. A final design of LH2-fueled transport aircraft was established which incorporates a preferred design of fuel system. That aircraft was then compared with a conventionally fueled counterpart designed to equivalent technology standards.

  17. The 21st LH Gray Conference (June 4-6, 2008)

    Energy Technology Data Exchange (ETDEWEB)

    West, C. M. L. [Univ. of Manchester (United Kingdom); Martin, C. J. [Gartnavel Royal Hospital, Glasgow (United Kingdom); Sutton, D. G. [Ninewells Hospital and Medical School, Dundee (United Kingdom); Wright, E. G. [Ninewells Hospital and Medical School, Dundee (United Kingdom)

    2009-01-12

    The 21st LH Gray Conference, organised by the LH Gray Trust with the Society for Radiological Protection, brought together international experts in radiobiology, epidemiology and risk assessment, and scientists involved in diagnostic and therapeutic radiation exposure. The meeting - held in Edinburgh, Scotland 4-6 June 2008 - aimed to raise awareness, educate and share knowledge of important issues in radiation protection. A distinguished group of speakers discussed topics which included: non-targeted effects of radiation, exposure to high natural background radiation, non-cancer effects in Japanese bomb survivors, lessons learnt from Chernobyl, radiation in the workplace, biokinetic modelling, uncertainties in risk estimation, issues in diagnostic medical exposures, lessons leant from the polonium-210 incidence and how the radiobiology-radiation oncology community is needed to help society prepare for potential future acts of radiation terrorism. The conference highlighted the importance, relevance and topicality of radiobiology today.

  18. Mean and oscillating plasma flows and turbulence interactions across the L-H confinement transition.

    Science.gov (United States)

    Conway, G D; Angioni, C; Ryter, F; Sauter, P; Vicente, J

    2011-02-11

    A complex interaction between turbulence driven E × B zonal flow oscillations, i.e., geodesic acoustic modes (GAMs), the turbulence, and mean equilibrium flows is observed during the low to high (L-H) plasma confinement mode transition in the ASDEX Upgrade tokamak. Below the L-H threshold at low densities a limit-cycle oscillation forms with competition between the turbulence level and the GAM flow shearing. At higher densities the cycle is diminished, while in the H mode the cycle duration becomes too short to sustain the GAM, which is replaced by large amplitude broadband flow perturbations. Initially GAM amplitude increases as the H-mode transition is approached, but is then suppressed in the H mode by enhanced mean flow shear.

  19. Spontaneous L-H transitions under marginal hot cathode biasing in the Tohoku University Heliac

    International Nuclear Information System (INIS)

    Kitajima, S; Takahashi, H; Tanaka, Y; Utoh, H; Yokoyama, M; Inagaki, S; Suzuki, Y; Nishimura, K; Shinde, J; Ogawa, M; Iwazaki, K; Aoyama, H; Okamoto, A; Shinto, K; Sasao, M

    2006-01-01

    A series of hot cathode biasing experiments with marginal conditions for improved mode transition were carried out in the Tohoku University Heliac (TU-Heliac). Spontaneous transitions were observed accompanied by a delay of a few milliseconds. Transition conditions were explored over a wide operation range. The transition points can be identified clearly and easily in the operation range, because the plasma parameters changed slowly until the spontaneous transition. Although operation conditions were spread over a wide range, poloidal Mach numbers for transitions were concentrated in the range of -M p = 1-2 and normalized driving forces for poloidal rotation agreed well with the local maximum value of ion viscosity predicted by neoclassical theory. The local maximum of ion viscosity against the poloidal Mach number was found to play a key role in the L-H transition. Marginal hot cathode biasing is suitable to determine the threshold conditions for the L-H transition

  20. EC + LH current drive efficiency in the presence of an internal transport barrier

    International Nuclear Information System (INIS)

    Rosa, P.R. da S; Ziebell, L.F.

    2002-01-01

    In this paper we study the effects of the presence of an internal transport barrier (ITB) on the current drive efficiency and power deposition profiles in the case of electron cyclotron waves interacting with an extended tail generated by lower hybrid (LH) waves. We study the subject by numerically solving the Fokker-Planck equation, with temperature and density profiles corrected along the time evolution at each collision time, based on the actual time-evolving electron distribution function. The results obtained show that the LH and electron cyclotron (EC) power absorption profiles and the current driven by the combined action of both types of waves are weakly dependent on the depth of the ITB, slightly more dependent on the level of magnetic turbulence and much more dependent on the level of EC wave power. (author)

  1. Study of a Novel Oscillating Surge Wave Energy Converter: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Tom, Nathan M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Choiniere, Michael [University of Maine; Thiagarajan, Krish P. [University of Maine

    2017-08-01

    This study investigates the performance of an oscillating surge wave energy converter (OSWEC) that utilizes adjustable geometry as a means of controlling the hydrodynamic coefficients, a concept originally proposed by [1]. The body of the device consists of a bottom-hinged solid rectangular frame with five horizontal flaps spanning the interior of the frame. The flaps can rotate independently about their center of rotation within the frame like a large window shutter. Changing the orientation of the flaps alters the hydrodynamic coefficients and natural frequency of the device as well as the ability to shed or absorb structural loads accordingly. This ability may allow the device to operate in a wider range of sea states than other current wave energy converter designs. This paper presents and compares the results of numerical simulations and experimental testing of the OSWEC's response to regular waves with all five of the horizontal fin configurations sharing the same orientation of 0 degrees (fully closed interior) and 90 degrees (fully open). The numerical simulations were performed using WAMIT, which calculates hydrodynamic coefficients using a boundary element method code to solve the linear potential flow problem, and WEC-Sim, a MATLAB-based tool that simulates multibody devices in the time domain by solving the governing equations of motion. A 1:14 scale model of the device was built for experimental evaluation in an 8-m-long, 1-m wide wave tank, which supports a water depth of 0.7 m. The OSWEC motion in different wave conditions was measured with displacement sensors while nonlinear wave-structure interaction effects like slamming and overtopping were captured using a high-speed camera and used to understand differences between the simulation and experiments.

  2. Reference Model 5 (RM5): Oscillating Surge Wave Energy Converter

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Y. H. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jenne, D. S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Thresher, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Copping, A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Geerlofs, S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hanna, L. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-01-01

    This report is an addendum to SAND2013-9040: Methodology for Design and Economic Analysis of Marine Energy Conversion (MEC) Technologies. This report describes an Oscillating Water Column Wave Energy Converter (OSWEC) reference model design in a complementary manner to Reference Models 1-4 contained in the above report. A conceptual design for a taut moored oscillating surge wave energy converter was developed. The design had an annual electrical power of 108 kilowatts (kW), rated power of 360 kW, and intended deployment at water depths between 50 m and 100 m. The study includes structural analysis, power output estimation, a hydraulic power conversion chain system, and mooring designs. The results were used to estimate device capital cost and annual operation and maintenance costs. The device performance and costs were used for the economic analysis, following the methodology presented in SAND2013-9040 that included costs for designing, manufacturing, deploying, and operating commercial-scale MEC arrays up to 100 devices. The levelized cost of energy estimated for the Reference Model 5 OSWEC, presented in this report, was for a single device and arrays of 10, 50, and 100 units, and it enabled the economic analysis to account for cost reductions associated with economies of scale. The baseline commercial levelized cost of energy estimate for the Reference Model 5 device in an array comprised of 10 units is $1.44/kilowatt-hour (kWh), and the value drops to approximately $0.69/kWh for an array of 100 units.

  3. The Association Between LH Serum Levels at the time of hCG Injection and Clinical Pregnancy during IVF

    Directory of Open Access Journals (Sweden)

    Budi Wiweko

    2015-12-01

    Full Text Available Some studies showed that recombinant follicle stimulating hormone (r-FSH administration without LH supplementation has a good success rate on in vitro fertilization (IVF. However, LH role in IVF has been controversial. This study was conducted to evaluate the association between serum LH levels at the time of hCG injection and clinical pregnancy during IVF. This retrospective study included 136 patients underwent long protocol IVF from January 2005 to December 2009 in Yasmin Clinic, Cipto Mangunkusumo Hospital, Jakarta. The controlled ovarian hyper-stimulation protocol used in this study was gonadotropin-releasing hormone (GnRH agonist and r-FSH.  Serum LH level was measured on the day of hCG administration and the outcome evaluated was the clinical pregnancy following IVF cycles. There were 32 IVF cycles resulted in pregnancy out of 136 cycles (23.5%. There was significant difference between serum LH levels on the day of hCG administration and clinical pregnancy outcome (p=0.036. LH serum level cut-off value of ≥1.050 IU/l was the best value to predict pregnancy outcome with 62.5% sensitivity, 59.4% specificity, 83.3% positive predictive value, and 32.76% negative predictive value. It was concluded that there was an association between serum LH levels at the time of hCG injection and clinical pregnancy during IVF. Keywords: IVF cycles, LH levels serum, hCG administration   Hubungan Kadar LH saat Penyuntikan hCG dengan Kejadian Kehamilan pada Fertilisasi In vitro Abstrak Pemberian follicles stimulating hormone rekombinan (r-FSH tanpa suplementasi LH memiliki tingkat keberhasilan fertilisasi in vitro (FIV yang baik namun, peran LH pada FIV masih kontroversial. Tujuan penelitian ini adalah untuk mengevaluasi hubungan antara kadar serum LH pada hari penyuntikan hCG dengan kehamilan klinis selama FIV. Penelitian retrospektif ini melibatkan 136 perempuan yang menjalani FIV siklus pertama dengan protokol panjang mulai bulan Januari 2005 sampai

  4. X-Rays from the Location of the Double-humped Transient ASASSN-15lh

    Science.gov (United States)

    Margutti, R.; Metzger, B. D.; Chornock, R.; Milisavljevic, D.; Berger, E.; Blanchard, P. K.; Guidorzi, C.; Migliori, G.; Kamble, A.; Lunnan, R.; Nicholl, M.; Coppejans, D. L.; Dall'Osso, S.; Drout, M. R.; Perna, R.; Sbarufatti, B.

    2017-02-01

    We present the detection of persistent soft X-ray radiation with {L}x˜ {10}41-1042 erg s-1 at the location of the extremely luminous, double-humped transient ASASSN-15lh as revealed by Chandra and Swift. We interpret this finding in the context of observations from our multiwavelength campaign, which revealed the presence of weak narrow nebular emission features from the host-galaxy nucleus and clear differences with respect to superluminous supernova optical spectra. Significant UV flux variability on short timescales detected at the time of the rebrightening disfavors the shock interaction scenario as the source of energy powering the long-lived UV emission, while deep radio limits exclude the presence of relativistic jets propagating into a low-density environment. We propose a model where the extreme luminosity and double-peaked temporal structure of ASASSN-15lh is powered by a central source of ionizing radiation that produces a sudden change in the ejecta opacity at later times. As a result, UV radiation can more easily escape, producing the second bump in the light curve. We discuss different interpretations for the intrinsic nature of the ionizing source. We conclude that, if the X-ray source is physically associated with the optical-UV transient, then ASASSN-15lh most likely represents the tidal disruption of a main-sequence star by the most massive spinning black hole detected to date. In this case, ASASSN-15lh and similar events discovered in the future would constitute the most direct probes of very massive, dormant, spinning, supermassive black holes in galaxies. Future monitoring of the X-rays may allow us to distinguish between the supernova hypothesis and the hypothesis of a tidal disruption event.

  5. Development of advanced materials composites for use as insulations for LH2 tanks

    Science.gov (United States)

    Lemons, C. R.; Salmassy, O. K.

    1973-01-01

    A study of thread-reinforced polyurethane foam and glass fabric liner, serving as internally bonded insulation for space shuttle LH2 tanks, is reported. Emphasis was placed on an insulation system capable of reentry and multiple reuse in the shuttle environment. The optimized manufacturing parameters associated with each element of the composite are established and the results, showing successful completion of subscale system evaluation tests using the shuttle flight environmental requirements, are given.

  6. High pressure near infrared study of the mutated light-harvesting complex LH2

    Directory of Open Access Journals (Sweden)

    Braun P.

    2005-01-01

    Full Text Available The pressure sensitivities of the near infrared spectra of the light-harvesting (LH2 complex and a mutant complex with a simplified BChl-B850 binding pocket were compared. In the mutant an abrupt change in the spectral properties occurred at 250 MPa, which was not observed with the native sample. Increased disorder due to collapse of the chromophore pocket is suggested.

  7. Warm-ion drift Alfven turbulence and the L-H transition

    International Nuclear Information System (INIS)

    Scott, B.

    1998-01-01

    Computations of fluid drift turbulence treating ions and electrons on equal footing, including both temperatures, are conducted in a model toroidal geometry. The resulting 'ion mixing mode' turbulence bears features of both electron drift-Alfven and ion temperature gradient turbulence, and nonlinear sensitivity to the relative strengths of the density and temperature gradients provides a possible route to the bifurcation needed for the L-H transition. (author)

  8. LH power deposition and CD efficiency studies by application of modulated power at JET

    International Nuclear Information System (INIS)

    Kirov, K.K.; Baranov, Yu.; Mailloux, J.; Mayoral, M.-L.; Nave, M.F.F.; Ongena, J.

    2010-01-01

    The lower hybrid (LH) power deposition and the current drive (CD) efficiency were assessed by the application of modulated LH power. Density and magnetic field scans were performed and the response of the electron temperature provided by the available electron cyclotron emission diagnostic was investigated by means of fast Fourier transform analysis. An innovative technique based on a comparison between modelled and experimental data was developed and used in the study. The LH waves are absorbed by fast electrons with energies of a few times the thermal one, causing a modification in the electron distribution function (EDF) by creating a plateau in the parallel direction. The phase of the temperature perturbations, φ, as well as the ratio between the amplitudes of the third and the main harmonics, δT e3 /δT e1 , are found to be strongly affected by the plateau of the EDF as the broader the plateau the larger |φ|, (φ e3 /δT e1 are. Transport and Fokker-Planck modelling was used to support this conclusion as well as to interpret the experimental data and hence to assess the LHCD efficiency and deposition profile. The results from the analysis are consistent with broad off-axis LH power deposition profile. For densities between 1 x 10 19 and 4 x 10 19 m -3 , which is the accessibility limit at the highest magnetic field discharges, a gradual shift of the maximum of the power deposition to the periphery and a degradation of the CD efficiency was observed.

  9. Heat loads on JET plasma facing components from ICRF and LH wave absorption in the SOL

    Czech Academy of Sciences Publication Activity Database

    Jacquet, P.; Colas, L.; Mayoral, M.-L.; Arnoux, G.; Bobkov, V.; Brix, M.; Coad, P.; Czarnecka, A.; Dodt, D.; Durodie, F.; Ekedahl, A.; Frigione, D.; Fursdon, M.; Gauthier, E.; Goniche, M.; Graham, M.; Joffrin, E.; Korotkov, A.; Lerche, E.; Mailloux, J.; Monakhov, I.; Noble, C.; Ongena, J.; Petržílka, Václav; Portafaix, C.; Rimini, F.; Sirinelli, A.; Riccardo, V.; Vizvary, Z.; Widdowson, A.; Zastrow, K.-D.

    2011-01-01

    Roč. 51, č. 10 (2011), s. 103018-103018 ISSN 0029-5515 R&D Projects: GA ČR GA202/07/0044 Institutional research plan: CEZ:AV0Z20430508 Keywords : LH wave * plasma Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 4.090, year: 2011 http://iopscience.iop.org/0029-5515/51/10/103018/pdf/0029-5515_51_10_103018.pdf

  10. Storm Surge Modeling of Typhoon Haiyan at the Naval Oceanographic Office Using Delft3D

    Science.gov (United States)

    Gilligan, M. J.; Lovering, J. L.

    2016-02-01

    The Naval Oceanographic Office provides estimates of the rise in sea level along the coast due to storm surge associated with tropical cyclones, typhoons, and hurricanes. Storm surge modeling and prediction helps the US Navy by providing a threat assessment tool to help protect Navy assets and provide support for humanitarian assistance/disaster relief efforts. Recent advancements in our modeling capabilities include the use of the Delft3D modeling suite as part of a Naval Research Laboratory (NRL) developed Coastal Surge Inundation Prediction System (CSIPS). Model simulations were performed on Typhoon Haiyan, which made landfall in the Philippines in November 2013. Comparisons of model simulations using forecast and hindcast track data highlight the importance of accurate storm track information for storm surge predictions. Model runs using the forecast track prediction and hindcast track information give maximum storm surge elevations of 4 meters and 6.1 meters, respectively. Model results for the hindcast simulation were compared with data published by the JSCE-PICE Joint survey for locations in San Pedro Bay (SPB) and on the Eastern Samar Peninsula (ESP). In SPB, where wind-induced set-up predominates, the model run using the forecast track predicted surge within 2 meters in 38% of survey locations and within 3 meters in 59% of the locations. When the hindcast track was used, the model predicted within 2 meters in 77% of the locations and within 3 meters in 95% of the locations. The model was unable to predict the high surge reported along the ESP produced by infragravity wave-induced set-up, which is not simulated in the model. Additional modeling capabilities incorporating infragravity waves are required to predict storm surge accurately along open coasts with steep bathymetric slopes, such as those seen in island arcs.

  11. Data Assimilation within the Advanced Circulation (ADCIRC) Modeling Framework for Hurricane Storm Surge Forecasting

    KAUST Repository

    Butler, T.

    2012-07-01

    Accurate, real-time forecasting of coastal inundation due to hurricanes and tropical storms is a challenging computational problem requiring high-fidelity forward models of currents and water levels driven by hurricane-force winds. Despite best efforts in computational modeling there will always be uncertainty in storm surge forecasts. In recent years, there has been significant instrumentation located along the coastal United States for the purpose of collecting data—specifically wind, water levels, and wave heights—during these extreme events. This type of data, if available in real time, could be used in a data assimilation framework to improve hurricane storm surge forecasts. In this paper a data assimilation methodology for storm surge forecasting based on the use of ensemble Kalman filters and the advanced circulation (ADCIRC) storm surge model is described. The singular evolutive interpolated Kalman (SEIK) filter has been shown to be effective at producing accurate results for ocean models using small ensemble sizes initialized by an empirical orthogonal function analysis. The SEIK filter is applied to the ADCIRC model to improve storm surge forecasting, particularly in capturing maximum water levels (high water marks) and the timing of the surge. Two test cases of data obtained from hindcast studies of Hurricanes Ike and Katrina are presented. It is shown that a modified SEIK filter with an inflation factor improves the accuracy of coarse-resolution forecasts of storm surge resulting from hurricanes. Furthermore, the SEIK filter requires only modest computational resources to obtain more accurate forecasts of storm surge in a constrained time window where forecasters must interact with emergency responders.

  12. Alternate Care Sites for the Management of Medical Surge in Disasters

    Science.gov (United States)

    2013-12-01

    care facilities are in place  Plan for community based surge hospital bed surge capacity is in place  A 50-bed nursing subunit—per 50,000...attempt to assess the preparedness of the hospital system, HHS/ASPR commissioned The Center for Biosecurity of UPMC to examine various responses to...catastrophic health efforts. The 11 report The Next Challenge in Healthcare Preparedness: Catastrophic Health Events (Center for Biosecurity of UPMC

  13. Radiological analyses of France Telecom surge arresters. Study performed for the CGT FAPT Cantal

    International Nuclear Information System (INIS)

    2010-02-01

    This document reports the radiological characterization of various versions of surge arresters used in the past to protect telephone lines against over-voltages. These equipment, which use various radioactive materials, were assessed by gamma radiation flow measurements, alpha-beta-gamma count rate measurements, dose rate measurements, gamma spectrometry analyses, tritium emanation test, radon 222 emanation test, smearing. Recommendations are formulated to manage radioactive surge arresters which are still being operated

  14. The Effect of Coastal Development on Storm Surge Flooding in Biscayne Bay, Florida, USA (Invited)

    Science.gov (United States)

    Zhang, K.; Liu, H.; Li, Y.

    2013-12-01

    Barrier islands and associated bays along the Atlantic and Gulf Coasts are a favorite place for both living and visiting. Many of them are vulnerable to storm surge flooding because of low elevations and constantly being subjected to the impacts of storms. The population increase and urban development along the barrier coast have altered the shoreline configuration, resulting in a dramatic change in the coastal flooding pattern in some areas. Here we present such a case based on numerical simulations of storm surge flooding caused by the1926 hurricane in the densely populated area surrounding Biscayne Bay in Miami, Florida. The construction of harbor and navigation channels, and the development of real estate and the roads connecting islands along Biscayne Bay have changed the geometry of Biscayne Bay since 1910s. Storm surge simulations show that the Port of Miami and Dodge Island constructed by human after 1950 play an important role in changing storm surge inundation pattern along Biscayne Bay. Dodge Island enhances storm surge and increases inundation in the area south of the island, especially at the mouth of Miami River (Downtown of Miami), and reduces storm surge flooding in the area north of the island, especially in Miami Beach. If the Hurricane Miami of 1926 happened today, the flooding area would be reduced by 55% and 20% in the Miami Beach and North Miami areas, respectively. Consequently, it would prevent 400 million of property and 10 thousand people from surge flooding according to 2010 U.S census and 2007 property tax data. Meanwhile, storm water would penetrate further inland south of Dodge Island and increase the flooding area by 25% in the Miami River and Downtown Miami areas. As a result, 200 million of property and five thousand people would be impacted by storm surge.

  15. Solvation effect of bacteriochlorophyll excitons in light-harvesting complex LH2.

    Science.gov (United States)

    Urboniene, V; Vrublevskaja, O; Trinkunas, G; Gall, A; Robert, B; Valkunas, L

    2007-09-15

    We have characterized the influence of the protein environment on the spectral properties of the bacteriochlorophyll (Bchl) molecules of the peripheral light-harvesting (or LH2) complex from Rhodobacter sphaeroides. The spectral density functions of the pigments responsible for the 800 and 850 nm electronic transitions were determined from the temperature dependence of the Bchl absorption spectra in different environments (detergent micelles and native membranes). The spectral density function is virtually independent of the hydrophobic support that the protein experiences. The reorganization energy for the B850 Bchls is 220 cm(-1), which is almost twice that of the B800 Bchls, and its Huang-Rhys factor reaches 8.4. Around the transition point temperature, and at higher temperatures, both the static spectral inhomogeneity and the resonance interactions become temperature-dependent. The inhomogeneous distribution function of the transitions exhibits less temperature dependence when LH2 is embedded in membranes, suggesting that the lipid phase protects the protein. However, the temperature dependence of the fluorescence spectra of LH2 cannot be fitted using the same parameters determined from the analysis of the absorption spectra. Correct fitting requires the lowest exciton states to be additionally shifted to the red, suggesting the reorganization of the exciton spectrum.

  16. The Evolution of Utilizing Manual Throttles to Avoid Low LH2 NPSP at the SSME Inlet

    Science.gov (United States)

    Henfling, Rick

    2011-01-01

    Even before the first flight of the Space Shuttle, it was understood low liquid hydrogen (LH2) Net Positive Suction Pressure (NPSP) at the inlet to the Space Shuttle Main Engine (SSME) can have adverse effects on engine operation. A number of failures within both the External Tank (ET) and the Orbiter Main Propulsion System could result in a low LH2 NPSP condition. Operational workarounds were developed to take advantage of the onboard crew s ability to manually throttle down the SSMEs, which alleviated the low LH2 NPSP condition. A throttling down of the SSME resulted in an increase in NPSP, mainly due to the reduction in frictional flow losses while at a lower throttle setting. As engineers refined their understanding of the NPSP requirements for the SSME (through a robust testing program), the operational techniques evolved to take advantage of these additional capabilities. Currently the procedure, which for early Space Shuttle missions required a Return-to-Launch-Site abort, now would result in a nominal Main Engine Cut Off (MECO) and no loss of mission objectives.

  17. Power injection performance of the LH antenna tipped with carbon grills in JT-60U

    International Nuclear Information System (INIS)

    Ishii, Kazuhiro; Seki, Masami; Shinozaki, Shinichi; Hasegawa, Koichi; Hiranai, Shinichi; Suzuki, Sadaaki; Sato, Fumiaki; Moriyama, Shinichi; Yokokura, Kenji

    2007-07-01

    The lower hybrid (LH) antenna in JT-60U has interaction with plasmas because it should be close to them in order to inject effectively radio frequency (RF) power into them. As a result, it has been a serious problem that the antenna mouth made of stainless steels was damaged due to excessive heat loads of plasmas and RF breakdowns. To solve the problem, a heat-resistant LH antenna was developed tipping carbon grills with fairly high heat resistance on the antenna mouth, and therefore reduction in damages on the mouth was expected. Power injection into plasmas was firstly performed with the heat-resistant antenna. RF conditioning was done carefully in the initial phase because RF breakdown due to outgassing from the grills might be occurred. After sufficient degassing was done through RF conditioning, RF power of about 1.6 MW x 10 sec injection was successfully injected to plasmas. Moreover it was demonstrated that it had comparably high plasma current drive capability (about 1.6 x 10 19 A/W/m 2 ), required as a current drive LH antenna. (author)

  18. Simulations of the L-H transition on experimental advanced superconducting Tokamak

    International Nuclear Information System (INIS)

    Weiland, Jan

    2014-01-01

    We have simulated the L-H transition on the EAST tokamak [Baonian Wan, EAST and HT-7 Teams, and International Collaborators, “Recent experiments in the EAST and HT-7 superconducting tokamaks,” Nucl. Fusion 49, 104011 (2009)] using a predictive transport code where ion and electron temperatures, electron density, and poloidal and toroidal momenta are simulated self consistently. This is, as far as we know, the first theory based simulation of an L-H transition including the whole radius and not making any assumptions about where the barrier should be formed. Another remarkable feature is that we get H-mode gradients in agreement with the α – α d diagram of Rogers et al. [Phys. Rev. Lett. 81, 4396 (1998)]. Then, the feedback loop emerging from the simulations means that the L-H power threshold increases with the temperature at the separatrix. This is a main feature of the C-mod experiments [Hubbard et al., Phys. Plasmas 14, 056109 (2007)]. This is also why the power threshold depends on the direction of the grad B drift in the scrape off layer and also why the power threshold increases with the magnetic field. A further significant general H-mode feature is that the density is much flatter in H-mode than in L-mode

  19. Airline view of LH2 as a fuel for commercial aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, K.G.

    1983-01-01

    Fuel for air transport is a particularly important matter, because it is an energy-intensive form of transport. Price and energy density are therefore correspondingly critical. Airlines views tend to be short term because there is no future if they do not survive tomorrow. Thus, although petroleum supply and price has been unstable since 1973, airlines' primary concern has been with economizing the use of fuel and specifying more fuel economic equipment for the future, rather than serious pursuit of more radical solutions. LH2 gives promise of being a serious candidate for the longer term, but there is not yet convincing proof that cheaper seat mile costs could be produced in today's circumstances. The situation could be changed by the realization of laminar flow by surface cooling at subsonic speeds. There is a strong case for a modest programme of carefully aimed research on an international basis to fill the most important gaps in our knowledge on the design of LH2 fueled aircraft. Future crises in energy supplies may well raise questions of transport fuel strategy which will heed this background for wise decision-making. Particular significance attaches to the place of nuclear power in world energy policy since this dominates the question of LH2 availability and price. 2 references, 2 figures.

  20. Storm surge evolution and its relationship to climate oscillations at Duck, NC

    Science.gov (United States)

    Munroe, Robert; Curtis, Scott

    2017-07-01

    Coastal communities experience increased vulnerability during storm surge events through the risk of damage to coastal infrastructure, erosion/deposition, and the endangerment of human life. Policy and planning measures attempt to avoid or mitigate storm surge consequences through building codes and setbacks, beach stabilization, insurance rates, and coastal zoning. The coastal emergency management community and public react and respond on shorter time scales, through temporary protection, emergency stockpiling, and evacuation. This study utilizes time series analysis, the Kolmogorov-Smirnov (K-S) test, Pearson's correlation, and the generalized extreme value (GEV) theorem to make the connection between climate oscillation indices and storm surge characteristics intra-seasonally to inter-annually. Results indicate that an El Niño (+ENSO), negative phase of the NAO, and positive phase of the PNA pattern all support longer duration and hence more powerful surge events, especially in winter. Increased surge duration increases the likelihood of extensive erosion, inland inundation, among other undesirable effects of the surge hazard.

  1. The value of wetlands in protecting southeast louisiana from hurricane storm surges.

    Science.gov (United States)

    Barbier, Edward B; Georgiou, Ioannis Y; Enchelmeyer, Brian; Reed, Denise J

    2013-01-01

    The Indian Ocean tsunami in 2004 and Hurricanes Katrina and Rita in 2005 have spurred global interest in the role of coastal wetlands and vegetation in reducing storm surge and flood damages. Evidence that coastal wetlands reduce storm surge and attenuate waves is often cited in support of restoring Gulf Coast wetlands to protect coastal communities and property from hurricane damage. Yet interdisciplinary studies combining hydrodynamic and economic analysis to explore this relationship for temperate marshes in the Gulf are lacking. By combining hydrodynamic analysis of simulated hurricane storm surges and economic valuation of expected property damages, we show that the presence of coastal marshes and their vegetation has a demonstrable effect on reducing storm surge levels, thus generating significant values in terms of protecting property in southeast Louisiana. Simulations for four storms along a sea to land transect show that surge levels decline with wetland continuity and vegetation roughness. Regressions confirm that wetland continuity and vegetation along the transect are effective in reducing storm surge levels. A 0.1 increase in wetland continuity per meter reduces property damages for the average affected area analyzed in southeast Louisiana, which includes New Orleans, by $99-$133, and a 0.001 increase in vegetation roughness decreases damages by $24-$43. These reduced damages are equivalent to saving 3 to 5 and 1 to 2 properties per storm for the average area, respectively.

  2. Probabilistic hurricane-induced storm surge hazard assessment in Guadeloupe, Lesser Antilles

    Science.gov (United States)

    Krien, Y.; Dudon, B.; Roger, J.; Zahibo, N.

    2015-08-01

    Current storm surge hazard maps in the French West Indies are essentially based on simple statistical methods using limited historical data and early low-resolution models which do not take the effect of waves into account. In this paper, we infer new 100-year and 1000-year surge levels in Guadeloupe from the numerical modelling of storm surges induced by a large set of synthetic events that are in statistical agreement with features of historical hurricanes in the North Atlantic Basin between 1980 and 2011. Computations are performed using the wave-current coupled model ADCIRC-SWAN with high grid resolutions (up to 40-60 m) in the coastal and wave dissipation areas. This model is validated against observations during past events such as hurricane HUGO (1989). Results are generally found to be in reasonable agreement with past studies in areas where surge is essentially wind-driven, but found to differ significantly in coastal regions where the transfer of momentum from waves to the water column constitutes a non-negligible part of the total surge. The methodology, which can be applied to other islands in the Lesser Antilles, allows storm surge level maps to be obtained that can be of major interest for coastal planners and decision makers in terms of risk management.

  3. Modeling Flood Inundation Induced by River Flow and Storm Surges over a River Basin

    Directory of Open Access Journals (Sweden)

    Wei-Bo Chen

    2014-10-01

    Full Text Available Low-lying coastal regions and their populations are at risk during storm surge events and high freshwater discharges from upriver. An integrated storm surge and flood inundation modeling system was used to simulate storm surge and inundation in the Tsengwen River basin and the adjacent coastal area in southern Taiwan. A three-dimensional hydrodynamic model with an unstructured grid was used, which was driven by the tidal elevation at the open boundaries and freshwater discharge at the upriver boundary. The model was validated against the observed water levels for three typhoon events. The simulation results for the model were in reasonable agreement with the observational data. The model was then applied to investigate the effects of a storm surge, freshwater discharge, and a storm surge combined with freshwater discharge during an extreme typhoon event. The super Typhoon Haiyan (2013 was artificially shifted to hit Taiwan: the modeling results showed that the inundation area and depth would cause severe overbank flow and coastal flooding for a 200 year return period flow. A high-resolution grid model is essential for the accurate simulation of storm surges and inundation.

  4. Fluid-structure interaction analysis for pressurizer surge line subjected to thermal stratification

    International Nuclear Information System (INIS)

    Kang, Dong Gu; Jhung, Myung Jo; Chang, Soon Heung

    2011-01-01

    Research highlights: → Temperature of surge line due to stratified flow is defined using CFD analysis. → Fluid-structure interaction analysis is performed to investigate the response characteristics due to thermal stress. → Fatigue usage factors due to thermal stratification are relatively low. → Simplifying temperature distribution in surge line is not always conservative. - Abstract: Serious mechanical damages such as cracks and plastic deformations due to excessive thermal stress caused by thermal stratification have been experienced in several nuclear power plants. In particular, the thermal stratification in the pressurizer surge line has been addressed as one of the significant safety and technical issues. In this study, a detailed unsteady computational fluid dynamics (CFD) analysis involving conjugate heat transfer analysis is performed to obtain the transient temperature distributions in the wall of the pressurizer surge line subjected to stratified internal flows either during out-surge or in-surge operation. The thermal loads from CFD calculations are transferred to the structural analysis code which is employed for the thermal stress analysis to investigate the response characteristics, and the fatigue analysis is ultimately performed. In addition, the thermal stress and fatigue analysis results obtained by applying the realistic temperature distributions from CFD calculations are compared with those by assuming the simplified temperature distributions to identify some requirements for a realistic and conservative thermal stress analysis from a safety point of view.

  5. The insulation coordination and surge arrester design for HTS cable system in Icheon substation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hansang, E-mail: Hansang80@korea.ac.kr [School of Railway and Electrical Engineering, Kyungil University, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-701 (Korea, Republic of); Yoon, Dong-Hee [Department of New and Renewable Energy, Kyungil University, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-701 (Korea, Republic of); Lee, Seung-Ryul [Korea Electrotechnology Research Institute, Naeson-dong, Uiwang-si, Gyeonggi-do 437-080 (Korea, Republic of); Yang, Byeong-Mo [Korea Electric Power Research Institute, Munji-dong, Yuseong-gu, Daejeon 305-760 (Korea, Republic of); Jang, Gilsoo, E-mail: gjang@korea.ac.kr [School of Electrical Engineering, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-713 (Korea, Republic of)

    2013-01-15

    Highlights: ► It is necessary to study lightning response of the HTS cable. ► The analytic model has been developed for the HTS cable in the Icheon substation. ► Well-designed surge arrester has been verified through PSCAD/EMTDC simulations. -- Abstract: This paper proposes an insulation coordination and surge arrester design for HTS (High-Temperature Superconducting) cable system in Icheon substation in Korea. In the aspect of the economic analysis, since the HTS cable is very expensive, the insulation coordination to prevent the dielectric breakdown caused by the lightning surge should be considered carefully. Also, in the aspect of the power system reliability, since the HTS cable has much more capacity compared than conventional power cables and the ripple effect from the HTS cable failure may lead to the wide area blackout, an intensive study for insulation coordination from lightning surge is one of the most important considerations. In this paper, the insulation coordination for lightning surge is verified using HTS cable and power equipment models and the design of the proper surge arrester is proposed.

  6. Effect of Hydraulic Accumulator on Pressure Surge of a Hydrostatic Transmission System

    Science.gov (United States)

    Kumar, Ajit; Das, Jayanta; Dasgupta, Kabir; Barnwal, Manish Kumar

    2018-04-01

    Hydraulic power system is generally used in off-road vehicles for power transmission such as Heavy Earth Moving Machineries (HEMM). Their energy efficiency and unsubstantial failure becomes an extensive subject of analysis. Various arrangements in the system are compassed along with the utilization of some appropriate components. Application of a hydraulic accumulator is one among them. Benefits of accumulator is its multi-purpose usages like energy saving and pressure surge damping. This paper deals with the control of pressure surges in the hydraulic system and energy saving from the surges by using accumulator. For this purpose, the simulation of the hydraulic system is done in MATLAB/SimulinkR environment and an external disturbance is introduced to generate the pressure surge. The surge absorptivity of the accumulator is studied for different sizes at different pre-charged conditions of the accumulator. The discharge characteristics of different sized accumulators are also analyzed in this paper. It is observed that the ability to absorb the surge and stabilize the system is high in the smaller capacity accumulator. However the energy delivery time of larger sized accumulator is high.

  7. Modeling and simulation of storm surge on Staten Island to understand inundation mitigation strategies

    Science.gov (United States)

    Kress, Michael E.; Benimoff, Alan I.; Fritz, William J.; Thatcher, Cindy A.; Blanton, Brian O.; Dzedzits, Eugene

    2016-01-01

    Hurricane Sandy made landfall on October 29, 2012, near Brigantine, New Jersey, and had a transformative impact on Staten Island and the New York Metropolitan area. Of the 43 New York City fatalities, 23 occurred on Staten Island. The borough, with a population of approximately 500,000, experienced some of the most devastating impacts of the storm. Since Hurricane Sandy, protective dunes have been constructed on the southeast shore of Staten Island. ADCIRC+SWAN model simulations run on The City University of New York's Cray XE6M, housed at the College of Staten Island, using updated topographic data show that the coast of Staten Island is still susceptible to tidal surge similar to those generated by Hurricane Sandy. Sandy hindcast simulations of storm surges focusing on Staten Island are in good agreement with observed storm tide measurements. Model results calculated from fine-scaled and coarse-scaled computational grids demonstrate that finer grids better resolve small differences in the topography of critical hydraulic control structures, which affect storm surge inundation levels. The storm surge simulations, based on post-storm topography obtained from high-resolution lidar, provide much-needed information to understand Staten Island's changing vulnerability to storm surge inundation. The results of fine-scale storm surge simulations can be used to inform efforts to improve resiliency to future storms. For example, protective barriers contain planned gaps in the dunes to provide for beach access that may inadvertently increase the vulnerability of the area.

  8. Crystallization and preliminary X-ray diffraction analysis of the peripheral light-harvesting complex LH2 from Marichromatium purpuratum.

    Science.gov (United States)

    Cranston, Laura J; Roszak, Aleksander W; Cogdell, Richard J

    2014-06-01

    LH2 from the purple photosynthetic bacterium Marichromatium (formerly known as Chromatium) purpuratum is an integral membrane pigment-protein complex that is involved in harvesting light energy and transferring it to the LH1-RC `core' complex. The purified LH2 complex was crystallized using the sitting-drop vapour-diffusion method at 294 K. The crystals diffracted to a resolution of 6 Å using synchrotron radiation and belonged to the tetragonal space group I4, with unit-cell parameters a=b=109.36, c=80.45 Å. The data appeared to be twinned, producing apparent diffraction symmetry I422. The tetragonal symmetry of the unit cell and diffraction for the crystals of the LH2 complex from this species reveal that this complex is an octamer.

  9. On the evocability of a positive oestrogen feedback action on LH secretion in transsexual men and women.

    Science.gov (United States)

    Dörner, G; Rohde, W; Seidel, K; Haas, W; Schott, G S

    1976-03-01

    In transsexual men with homosexual behaviour and intact testicular function, as well as in homosexual men with normal gender identity, following a negative oestrogen feedback effect a delayed positive oestrogen feedback action on LH secretion was evoked. By contrast, in transsexual men with hypo- or asexuality and intact testes or hypergonadotrophic hypo- or agonadism, as well as in heterosexual men with normal gender identity, a negative oestrogen feedback effect was not followed by a positive feedback action on LH release. In transsexual women with homosexual behaviour and oligo- and/or hypomenorrhoea, only a weak or at best moderate positive oestrogen feedback action on LH release was evocable, similarly as in castrated and oestrogen-primed heterosexual men. By contrast, in a transsexual woman with bisexual behaviour and eumenorrhoea, a strong positive oestrogen feedback action on LH secretion was evocable, as well as in heterosexual women with normal gender identity.

  10. Relationship between release of LH and incorporation of tritiated thymidine in the anterior pituitary gland of the castrated female rat.

    Science.gov (United States)

    Machiavelli, G A; Romano, M I; Burdman, J A

    1985-06-01

    Castration of female rats during diestrus increases the concentration of circulating LH from days 3 and the incorporation of 3H thymidine into pituitary DNA from day 5. Both effects are completely abolished by the administration of dihydrotestosterone. Although the i.v. injection of LHRH markedly enhances the concentration of LH in serum, it does not modify the incorporation of 3H thymidine into pituitary DNA. Castration might produce a maximal stimulation in 3H thymidine incorporation and a further stimulation of LH release with LHRH is unable to enhance the incorporation of the radioactive precursor. The results suggest a relationship between LH secretion and DNA synthesis in the pituitary gland of the rat.

  11. Identification of storm surge vulnerable areas in the Philippines through the simulation of Typhoon Haiyan-induced storm surge levels over historical storm tracks

    Science.gov (United States)

    Lapidez, J. P.; Tablazon, J.; Dasallas, L.; Gonzalo, L. A.; Cabacaba, K. M.; Ramos, M. M. A.; Suarez, J. K.; Santiago, J.; Lagmay, A. M. F.; Malano, V.

    2015-07-01

    Super Typhoon Haiyan entered the Philippine Area of Responsibility (PAR) on 7 November 2013, causing tremendous damage to infrastructure and loss of lives mainly due to the storm surge and strong winds. Storm surges up to a height of 7 m were reported in the hardest hit areas. The threat imposed by this kind of natural calamity compelled researchers of the Nationwide Operational Assessment of Hazards (Project NOAH) which is the flagship disaster mitigation program of the Department of Science and Technology (DOST) of the Philippine government to undertake a study to determine the vulnerability of all Philippine coastal communities to storm surges of the same magnitude as those generated by Haiyan. This study calculates the maximum probable storm surge height for every coastal locality by running simulations of Haiyan-type conditions but with tracks of tropical cyclones that entered PAR from 1948-2013. One product of this study is a list of the 30 most vulnerable coastal areas that can be used as a basis for choosing priority sites for further studies to implement appropriate site-specific solutions for flood risk management. Another product is the storm tide inundation maps that the local government units can use to develop a risk-sensitive land use plan for identifying appropriate areas to build residential buildings, evacuation sites, and other critical facilities and lifelines. The maps can also be used to develop a disaster response plan and evacuation scheme.

  12. Identification of storm surge vulnerable areas in the Philippines through the simulation of Typhoon Haiyan-induced storm surge levels over historical storm tracks

    Directory of Open Access Journals (Sweden)

    J. P. Lapidez

    2015-07-01

    Full Text Available Super Typhoon Haiyan entered the Philippine Area of Responsibility (PAR on 7 November 2013, causing tremendous damage to infrastructure and loss of lives mainly due to the storm surge and strong winds. Storm surges up to a height of 7 m were reported in the hardest hit areas. The threat imposed by this kind of natural calamity compelled researchers of the Nationwide Operational Assessment of Hazards (Project NOAH which is the flagship disaster mitigation program of the Department of Science and Technology (DOST of the Philippine government to undertake a study to determine the vulnerability of all Philippine coastal communities to storm surges of the same magnitude as those generated by Haiyan. This study calculates the maximum probable storm surge height for every coastal locality by running simulations of Haiyan-type conditions but with tracks of tropical cyclones that entered PAR from 1948–2013. One product of this study is a list of the 30 most vulnerable coastal areas that can be used as a basis for choosing priority sites for further studies to implement appropriate site-specific solutions for flood risk management. Another product is the storm tide inundation maps that the local government units can use to develop a risk-sensitive land use plan for identifying appropriate areas to build residential buildings, evacuation sites, and other critical facilities and lifelines. The maps can also be used to develop a disaster response plan and evacuation scheme.

  13. Peripheral Light-Harvesting LH2 Complex Can Be Assembled in Cells of Nonsulfur Purple Bacterium Rhodoblastus acidophilus without Carotenoids.

    Science.gov (United States)

    Bol'shakov, M A; Ashikhmin, A A; Makhneva, Z K; Moskalenko, A A

    2015-09-01

    The effect of carotenoids on the assembly of LH2 complex in cells of the purple nonsulfur bacterium Rhodoblastus acidophilus was investigated. For this purpose, the bacterial culture was cultivated with an inhibitor of carotenoid biosynthesis - 71 µM diphenylamine (DPA). The inhibitor decreased the level of biosynthesis of the colored carotenoids in membranes by ~58%. It was found that a large amount of phytoene was accumulated in them. This carotenoid precursor was bound nonspecifically to LH2 complex and did not stabilize its structure. Thermostability testing of the isolated LH2 complex together with analysis of carotenoid composition revealed that the population of this complex was heterogeneous with respect to carotenoid composition. One fraction of the LH2 complex with carotenoid content around 90% remains stable and was not destroyed under heating for 15 min at 50°C. The other fraction of LH2 complex containing on average less than one molecule of carotenoid per complex was destroyed under heating, forming a zone of free pigments (and polypeptides). The data suggest that a certain part of the LH2 complexes is assembled without carotenoids in cells of the nonsulfur bacterium Rbl. acidophilus grown with DPA. These data contradict the fact that the LH2 complex from nonsulfur bacteria cannot be assembled without carotenoids, but on the other hand, they are in good agreement with the results demonstrated in our earlier studies of the sulfur bacteria Allochromatium minutissimum and Ectothiorhodospira haloalkaliphila. Carotenoidless LH2 complex was obtained from these bacteria with the use of DPA (Moskalenko, A. A., and Makhneva, Z. K. (2012) J. Photochem. Photobiol., 108, 1-7; Ashikhmin, A., et al. (2014) Photosynth. Res., 119, 291-303).

  14. The effects of Vitex agnus castus extract and its interaction with dopaminergic system on LH and testosterone in male mice.

    Science.gov (United States)

    Nasri, Sima; Oryan, Shahrbano; Rohani, Ali Haeri; Amin, Gholam Reza

    2007-07-15

    The purpose of this study was to evaluate the probable effects of Vitex agnus castus (Vac.) on the male reproductive physiology. It is a well known fact that LH secretion from the anterior pituitary of mammals is controlled by many neurotransmiters such as dopamine. In this experiment, we have studied the effect of Vac. extract on the LH and testosterone hormones and its interaction with the dopaminergic system on male mice. In order to evaluate these effects, we used the hydroalcoholic Vac. extract (for extraction we used percolation technique) injection with the following doses: 65, 165, 265, 365 and 465 mg kg-', bromocriptine as a dopamine receptor agonist (5, 10, 20 mg kg(-1)) and haloperidol as a dopamine receptor antagonist (1, 1.5, 2, 2.5, 3 mg kg(-1)). To study the interaction between Vac. extract and dopaminergic system, we injected the optimum doses of Vac. with bromocriptine or haloperidol at the same time. Intraperitoneal injections were applied in all experiments, once a day for 30 days. The control group remained intact and the sham group received vehicle. After the last injection, we collected the animal blood serums for hormonal assays. LH and testosterone were measured by Radio Immuno Assay (RIA). LH and testosterone, showed significant decrease in bromocriptine group and haloperidol increased these hormones. Vac. extract decreased significantly the LH and testosterone levels. The coadministration of Vac. extract and bromocriptine decreased LH and testosterone. Coadministration of Vac. extract and haloperidol decreased LH and testosterone levels. These results suggest: dopamine regulates the gonadotroph-leydig cells axis. It appears that Vac. exertes effects through dopaminergic system and other pathways. The findings of this study show we can use Vac. extract for pathological cases of increasing LH and testosterone.

  15. The Use of rLH, HMG and hCG in Controlled Ovarian Stimulation for Assisted Reproductive Technologies

    Science.gov (United States)

    2012-11-21

    responders involves the use of the microdose flare protocol. This protocol avoids the profound suppression of endogenous LH and FSH in the early...follicular phase normally achieved with long luteal downregulation protocols. Scott and Novat’s initial investigation of the microdose flare found it to...protocol increases live birth rates (113-116). One RCT did not show any benefit to adding either rLH or low-dose rHCG to a microdose flare protocol for

  16. Production of anti-IgG antibodies in sheep for using in the radioimmunoassays of LH, FSH and prolactin

    International Nuclear Information System (INIS)

    Caso, R.; Perez, E.; Mosquera, M.; Arranz, C.

    1996-01-01

    In this work described the production of second antibodies in sheep against rabbit IgG for being used in radioimmunoassays for determination LH, FSH and Prolactin. There was made the comparison between the results obtained using the Kits-RIA produced by us and the commercial WHO Kits-RIA, using these antibodies. The results allowed us to use these antibodies for production Kits-RIA of LH, FSH and Prolactin

  17. Selection of gonadotrophin surge attenuating factor phage antibodies by bioassay.

    Science.gov (United States)

    Sorsa-Leslie, Tarja; Mason, Helen D; Harris, William J; Fowler, Paul A

    2005-09-26

    We aimed to combine the generation of "artificial" antibodies with a rat pituitary bioassay as a new strategy to overcome 20 years of difficulties in the purification of gonadotrophin surge-attenuating factor (GnSAF). A synthetic single-chain antibody (Tomlinson J) phage display library was bio-panned with partially purified GnSAF produced by cultured human granulosa/luteal cells. The initial screening with a simple binding immunoassay resulted in 8 clones that were further screened using our in-vitro rat monolayer bioassay for GnSAF. Initially the antibodies were screened as pooled phage forms and subsequently as individual, soluble, single-chain antibody (scAbs) forms. Then, in order to improve the stability of the scAbs for immunopurification purposes, and to widen the range of labelled secondary antibodies available, these were engineered into full-length human immunoglobulins. The immunoglobulin with the highest affinity for GnSAF and a previously described rat anti-GnSAF polyclonal antiserum was then used to immunopurify bioactive GnSAF protein. The two purified preparations were electrophoresed on 1-D gels and on 7 cm 2-D gels (pH 4-7). The candidate GnSAF protein bands and spots were then excised for peptide mass mapping. Three of the scAbs recognised GnSAF bioactivity and subsequently one clone of the purified scAb-derived immunoglobulin demonstrated high affinity for GnSAF bioactivity, also binding the molecule in such as way as to block its bioactivity. When used for repeated immunopurification cycles and then Western blot, this antibody enabled the isolation of a GnSAF-bioactive protein band at around 66 kDa. Similar results were achieved using the rat anti-GnSAF polyclonal antiserum. The main candidate molecules identified from the immunopurified material by excision of 2-D gel protein spots was human serum albumin precursor and variants. This study demonstrates that the combination of bioassay and phage display technologies is a powerful tool in the

  18. Development of Low Surge Vacuum Contact with Te

    Energy Technology Data Exchange (ETDEWEB)

    Kim, B. S.; Lee, H. W.; Woo, B. C.; Kim, B. G. [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

    1996-12-01

    The purpose of this study is to develop of low surge Te contact for vacuum circuit breaker. The vacuum circuit breaker have various advantages such that it is free from maintenance, does not bring about public pollution, is excellent in its current breaking property, and so forth, on account of which the extent of its application has become broadened rapidly. For the characteristics of the contact material for the vacuum circuit breaker to satisfy, there may be enumerated: (1)large current breaking capacity; (2)high voltage withstand; (3)small contact resistance; (4)small melt-adhesive force; (5)low chopping current value; (6)good workability; (7)sufficient mechanical strength; and so forth. In this study we used cobalt for based refractory material having high melting temperature and intermetallic material between tellurium and silver to reduce chopping current. The contact materials were produced in accordance with the powder metallurgy using the method of infiltration. Production of the contact material was carried out in such a method that cobalt powder having average particle size of 50{mu}m, pre sintered in H{sub 2} atmosphere, 900 degree C , 2 hour. Ag ingot and Te(Se) were alloyed using high frequency furnaced in vacuum. And then Ag-Te(Se) alloy was infiltrated to Co skeleton in H{sub 2} atmosphere, 1000 degree C , 1 hour. The melting of the alloy to be infiltrated was carried out in a vacuum sealed quartz tube and be analysed by X-ray diffraction, scanning electron microscope, optical microscope and energy dispersive energy spectrometer. In the alloying of silver and tellurium, tellurium does not exist in single element but Ag{sub 2}Te intermetallic compound. And In Ag and Se, Se does not exist in single element but Ag{sub 2}Se intermetallic compound. We also produced the test vacuum interruptor to evaluate the electrode properties in vacuum atmosphere. The electrical properties of Co-(Ag-Se) electrode have better value than that of Co-(Ag-Te) electrode

  19. Function of membrane protein in silica nanopores: incorporation of photosynthetic light-harvesting protein LH2 into FSM.

    Science.gov (United States)

    Oda, Ippei; Hirata, Kotaro; Watanabe, Syoko; Shibata, Yutaka; Kajino, Tsutomu; Fukushima, Yoshiaki; Iwai, Satoshi; Itoh, Shigeru

    2006-01-26

    A high amount of functional membrane protein complex was introduced into a folded-sheet silica mesoporous material (FSM) that has nanometer-size pores of honeycomb-like hexagonal cylindrical structure inside. The photosynthetic light-harvesting complex LH2, which is a typical membrane protein, has a cylindrical structure of 7.3 nm diameter and contains 27 bacteriochlorophyll a and nine carotenoid molecules. The complex captures light energy in the anoxygenic thermophilic purple photosynthetic bacterium Thermochromatium tepidum. The amount of LH2 adsorbed to FSM was determined optically and by the adsorption isotherms of N2. The FSM compounds with internal pore diameters of 7.9 and 2.7 nm adsorbed LH2 at 1.11 and 0.24 mg/mg FSM, respectively, suggesting the high specific affinity of LH2 to the interior of the hydrophobic nanopores with a diameter of 7.9 nm. The LH2 adsorbed to FSM showed almost intact absorption bands of bacteriochlorophylls, and was fully active in the capture and transfer of excitation energy. The LH2 complex inside the FSM showed increased heat stability of the exciton-type absorption band of bacteriochlorophylls (B850), suggesting higher circular symmetry. The environment inside the hydrophobic silica nanopores can be a new matrix for the membrane proteins to reveal their functions. The silica-membrane protein adduct will be useful for the construction of new probes and reaction systems.

  20. Correlation between LH secretion in castrated rats with cellular proliferation and synthesis of DNA in the anterior pituitary gland.

    Science.gov (United States)

    Romano, M I; Machiavelli, G A; Pérez, R L; Carricarte, V; Burdman, J A

    1984-07-01

    The relationship between the release of LH and the synthesis of DNA was studied in the anterior pituitary gland of castrated rats. Cell types were characterized immunocytochemically. Castration significantly (P less than 0.01) increased the concentration of LH in serum (1326%) and the incorporation of [3H]thymidine into pituitary DNA (72%). This was accompanied by an increment in the activity of the enzyme DNA polymerase-alpha (58%) and in the number of mitoses (from 2 +/- 0.1/mm2 in intact rats to 21 +/- 0.8/mm2 15 days after castration). Only 20% of the mitoses found in the pituitary gland of castrated rats were positively stained with the antiserum against the beta-subunit of LH. The other 80% did not stain either with LH antiserum or with antisera against the other pituitary hormones. There was a significant (P less than 0.01) increase in the number of LH cells in castrated rats (48%). All the changes produced in the anterior pituitary gland after castration were prevented by the administration of dihydrotestosterone. The results demonstrate that a stimulation of LH release is followed by an increase of DNA synthesis and cell proliferation of gonadotrophs in the anterior pituitary gland.

  1. Adrenergic system participation on LH secretion in pre-pubertal Nelore heifers Participação do sistema adrenérgico na secreção de LH, em novilhas nelores

    Directory of Open Access Journals (Sweden)

    Guilherme Paula Nogueira

    2008-12-01

    Full Text Available The aim of this study was to evaluate the response of clonidine administration (alfa-adrenoceptor agonist, 10g/kg body weight, i.v. and blood collected every 15 min for 4 h thereafter on luteinizing hormone (LH secretion in B. indicus pre-pubertal heifers at 8, 12 e 15 months of age. LH was quantified by RIA, sensitivity (0.05 ng/mL and coefficient of variation (20.39%. Alfa-adrenoceptor action (clonidine reduced (P<0,05 basal LH and time to greatest peak occurrence at 15 months-old and increased (P>0,05 peak total area and area of highest peak of LH secretion to 8 months-old. The results suggest reduced hypothalamic sensibility by gonadal steroid in pre-pubertal Nelore heifer maturation sexual and clonidine neurotransmitter participation, either stimulating or inhibiting LH secretion.Objetivou-se com este trabalho investigar a variação na secreção do hormônio luteinizante (LH em resposta ao tratamento com clonidina (agonista alfa-adrenérgico, 10µg/kg, i.v., amostras 15 min por 4h, em novilhas da raça Nelore pré-púberes aos 8, 12 e 15 meses de idade. A concentração de LH foi quantificada por radioimunoensaio, sensibilidade de 0,05 ng/mL e coeficiente de variação de 20,39%. A ativação de receptores alfa-adrenérgicos por intermédio da clonidina diminuiu (P<0,05 a concentração de LH e o tempo necessário para o aparecimento do maior pico de LH aos 15 meses de idade e aumentou (P>0,05 a área total e área do maior pico de secreção de LH aos 8 meses de idade. Os resultados indicam diminuição da sensibilidade do hipotálamo aos esteróides gonadais durante o processo de maturação sexual nas novilhas da raça Nelore e a participação da clonidina como neurotransmissora.

  2. Runoff-generated debris flows: observations and modeling of surge initiation, magnitude, and frequency

    Science.gov (United States)

    Kean, Jason W.; McCoy, Scott W.; Tucker, Gregory E.; Staley, Dennis M.; Coe, Jeffrey A.

    2013-01-01

    Runoff during intense rainstorms plays a major role in generating debris flows in many alpine areas and burned steeplands. Yet compared to debris flow initiation from shallow landslides, the mechanics by which runoff generates a debris flow are less understood. To better understand debris flow initiation by surface water runoff, we monitored flow stage and rainfall associated with debris flows in the headwaters of two small catchments: a bedrock-dominated alpine basin in central Colorado (0.06 km2) and a recently burned area in southern California (0.01 km2). We also obtained video footage of debris flow initiation and flow dynamics from three cameras at the Colorado site. Stage observations at both sites display distinct patterns in debris flow surge characteristics relative to rainfall intensity (I). We observe small, quasiperiodic surges at low I; large, quasiperiodic surges at intermediate I; and a single large surge followed by small-amplitude fluctuations about a more steady high flow at high I. Video observations of surge formation lead us to the hypothesis that these flow patterns are controlled by upstream variations in channel slope, in which low-gradient sections act as “sediment capacitors,” temporarily storing incoming bed load transported by water flow and periodically releasing the accumulated sediment as a debris flow surge. To explore this hypothesis, we develop a simple one-dimensional morphodynamic model of a sediment capacitor that consists of a system of coupled equations for water flow, bed load transport, slope stability, and mass flow. This model reproduces the essential patterns in surge magnitude and frequency with rainfall intensity observed at the two field sites and provides a new framework for predicting the runoff threshold for debris flow initiation in a burned or alpine setting.

  3. Improvement of Performance Range of Centrifugal Compressors Gas by Surge Line Modification Using Active Controller Based on Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Pezhman Mohammadi

    2012-04-01

    Full Text Available In this work, surge of prevention is a critical problem in oil and gas industries, particularly when return gas flow or gas flow reduces in transportation of gas pipelines. This paper is illustrated new results about surge control of centrifugal compressors .surge phenomenon is flow unsteady state in compressors which causes damages seriously in compressor construction. Furthermore, it also demonstrates in comparison with anti surge control ،active surge control expands stability range.Active surge control which based on fuzzy logic،is the main idea that used in this investigation. Using fuzzy controller causes an improvement in compressor's condition and increase performance range of the compressor, in addition to prevention of any instability in compressor. The simulation results is also satisfactory.

  4. Induction of ovarian cystic follicles in sheep.

    Science.gov (United States)

    Christman, S A; Bailey, M T; Head, W A; Wheaton, J E

    2000-10-01

    Cystic follicles are a significant cause of infertility in women, dairy cattle and sheep. Sheep were used as a model to identify factors that may elicit formation of cystic follicles. Insulin resistance and elevated LH activity were tested in overweight ewes because of associations among these factors and the formation of cystic follicles. Sheep were synchronized using a progesterone-releasing pessary and insulin resistance was induced during the synchronization period through administration of bovine somatotropin. Following removal of pessaries follicular growth was stimulated by treatment with eCG or eCG and hCG (PG-600). Follicular growth was monitored via daily transrectal ultrasonography and blood samples were collected for hormonal analyses. Six of 18 ewes had a subnormal or absent preovulatory gonadotropin surge and developed cystic follicles. Neither insulin resistance nor elevated LH activity were associated with formation of cystic follicles. Ewes that developed cystic follicles were heavier (93 +/- 4 kg) than ewes that ovulated (81 +/- 3 kg; P = 0.02). Furthermore, following pessary removal and initiation of daily ultrasonography, ewes that developed cystic follicles lost body weight (-3 +/- 1%), while ovulatory ewes continued to gain body weight (1 +/- 1%; P = 0.005). It is speculated that in heavy ewes metabolic factors associated with acute body weight loss inhibit the positive feedback of estradiol and thereby suppress the preovulatory gonadotropin surge leading to formation of cystic follicles.

  5. Assessment of the Temporal Evolution of Storm Surge via Land to Water Isopleths in Coastal Louisiana

    Science.gov (United States)

    Siverd, C. G.; Hagen, S. C.; Bilskie, M. V.; Braud, D.; Gao, S.; Peele, H.; Twilley, R.

    2017-12-01

    The low-lying coastal Louisiana deltaic landscape features an intricate system of fragmented wetlands, natural ridges, man-made navigation canals and flood protection infrastructure. Since 1900 and prior to the landfall of Hurricane Katrina in 2005, Louisiana lost approximately 480,000 ha (1,850 sq mi) of coastal wetlands and an additional 20,000 ha (77 sq mi) due to Katrina. This resulted in a total wetland storm protection value loss of USD 28.3 billion and USD 1.1 billion, respectively (Costanza 2008). To investigate the response of hurricane storm surge (e.g. peak water levels, inundation time and extent) through time due to land loss, hydrodynamic models that represent historical eras of the Louisiana coastal landscape were developed. Land:Water (L:W) isopleths (Gagliano 1970, 1971, Twilley 2016) have been calculated along the coast from the Sabine River to the Pearl River. These isopleths were utilized to create a simplified coastal landscape (bathymetry, topography, bottom roughness) representing circa 2010. Similar methodologies are employed with the objective of developing storm surge models that represent the coastal landscape for past eras. The goal is to temporally examine the evolution of storm surge along coastal Louisiana. The isopleths determined to best represent the Louisiana coast as a result of the methodology devised to develop the simple storm surge model for c.2010 are applied in the development of surge models for historical eras c.1930 and c.1970. The ADvaced CIRCulation (ADCIRC) code (Luettich 2004) is used to perform storm surge simulations with a predetermined suite of hurricane wind and pressure forcings. Hydrologic Unit Code 12 (HUC12) sub-watersheds provide geographical bounds to quantify mean maximum water surface elevations (WSEs), volume of inundation, and area of inundation. HUC12 sub-watersheds also provide a means to compare/contrast these quantified surge parameters on a HUC12-by-HUC12 basis for the c.1930, c.1970 and c.2010

  6. InSAR Observations and Finite Element Modeling of Crustal Deformation Around a Surging Glacier, Iceland

    Science.gov (United States)

    Spaans, K.; Auriac, A.; Sigmundsson, F.; Hooper, A. J.; Bjornsson, H.; Pálsson, F.; Pinel, V.; Feigl, K. L.

    2014-12-01

    Icelandic ice caps, covering ~11% of the country, are known to be surging glaciers. Such process implies an important local crustal subsidence due to the large ice mass being transported to the ice edge during the surge in a few months only. In 1993-1995, a glacial surge occurred at four neighboring outlet glaciers in the southwestern part of Vatnajökull ice cap, the largest ice cap in Iceland. We estimated that ~16±1 km3 of ice have been moved during this event while the fronts of some of the outlet glaciers advanced by ~1 km.Surface deformation associated with this surge has been surveyed using Interferometric Synthetic Aperture Radar (InSAR) acquisitions from 1992-2002, providing high resolution ground observations of the study area. The data show about 75 mm subsidence at the ice edge of the outlet glaciers following the transport of the large volume of ice during the surge (Fig. 1). The long time span covered by the InSAR images enabled us to remove ~12 mm/yr of uplift occurring in this area due to glacial isostatic adjustment from the retreat of Vatnajökull ice cap since the end of the Little Ice Age in Iceland. We then used finite element modeling to investigate the elastic Earth response to the surge, as well as confirm that no significant viscoelastic deformation occurred as a consequence of the surge. A statistical approach based on Bayes' rule was used to compare the models to the observations and obtain an estimate of the Young's modulus (E) and Poisson's ratio (v) in Iceland. The best-fitting models are those using a one-kilometer thick top layer with v=0.17 and E between 12.9-15.3 GPa underlain by a layer with v=0.25 and E from 67.3 to 81.9 GPa. Results demonstrate that InSAR data and finite element models can be used successfully to reproduce crustal deformation induced by ice mass variations at Icelandic ice caps.Fig. 1: Interferograms spanning 1993 July 31 to 1995 June 19, showing the surge at Tungnaárjökull (Tu.), Skaftárjökull (Sk.) and S

  7. Probabilistic storm surge inundation maps for Metro Manila based on Philippine public storm warning signals

    Science.gov (United States)

    Tablazon, J.; Caro, C. V.; Lagmay, A. M. F.; Briones, J. B. L.; Dasallas, L.; Lapidez, J. P.; Santiago, J.; Suarez, J. K.; Ladiero, C.; Gonzalo, L. A.; Mungcal, M. T. F.; Malano, V.

    2015-03-01

    A storm surge is the sudden rise of sea water over the astronomical tides, generated by an approaching storm. This event poses a major threat to the Philippine coastal areas, as manifested by Typhoon Haiyan on 8 November 2013. This hydro-meteorological hazard is one of the main reasons for the high number of casualties due to the typhoon, with 6300 deaths. It became evident that the need to develop a storm surge inundation map is of utmost importance. To develop these maps, the Nationwide Operational Assessment of Hazards under the Department of Science and Technology (DOST-Project NOAH) simulated historical tropical cyclones that entered the Philippine Area of Responsibility. The Japan Meteorological Agency storm surge model was used to simulate storm surge heights. The frequency distribution of the maximum storm surge heights was calculated using simulation results of tropical cyclones under a specific public storm warning signal (PSWS) that passed through a particular coastal area. This determines the storm surge height corresponding to a given probability of occurrence. The storm surge heights from the model were added to the maximum astronomical tide data from WXTide software. The team then created maps of inundation for a specific PSWS using the probability of exceedance derived from the frequency distribution. Buildings and other structures were assigned a probability of exceedance depending on their occupancy category, i.e., 1% probability of exceedance for critical facilities, 10% probability of exceedance for special occupancy structures, and 25% for standard occupancy and miscellaneous structures. The maps produced show the storm-surge-vulnerable areas in Metro Manila, illustrated by the flood depth of up to 4 m and extent of up to 6.5 km from the coastline. This information can help local government units in developing early warning systems, disaster preparedness and mitigation plans, vulnerability assessments, risk-sensitive land use plans, shoreline

  8. Centrifugal Compressor Surge Margin Improved With Diffuser Hub Surface Air Injection

    Science.gov (United States)

    Skoch, Gary J.

    2002-01-01

    Aerodynamic stability is an important parameter in the design of compressors for aircraft gas turbine engines. Compression system instabilities can cause compressor surge, which may lead to the loss of an aircraft. As a result, engine designers include a margin of safety between the operating line of the engine and the stability limit line of the compressor. The margin of safety is typically referred to as "surge margin." Achieving the highest possible level of surge margin while meeting design point performance objectives is the goal of the compressor designer. However, performance goals often must be compromised in order to achieve adequate levels of surge margin. Techniques to improve surge margin will permit more aggressive compressor designs. Centrifugal compressor surge margin improvement was demonstrated at the NASA Glenn Research Center by injecting air into the vaned diffuser of a 4:1-pressure-ratio centrifugal compressor. Tests were performed using injector nozzles located on the diffuser hub surface of a vane-island diffuser in the vaneless region between the impeller trailing edge and the diffuser-vane leading edge. The nozzle flow path and discharge shape were designed to produce an air stream that remained tangent to the hub surface as it traveled into the diffuser passage. Injector nozzles were located near the leading edge of 23 of the 24 diffuser vanes. One passage did not contain an injector so that instrumentation located in that passage would be preserved. Several orientations of the injected stream relative to the diffuser vane leading edge were tested over a range of injected flow rates. Only steady flow (nonpulsed) air injection was tested. At 100 percent of the design speed, a 15-percent improvement in the baseline surge margin was achieved with a nozzle orientation that produced a jet that was bisected by the diffuser vane leading edge. Other orientations also improved the baseline surge margin. Tests were conducted at speeds below the

  9. Long-term deconditioning of gas-filled surge arresters

    Science.gov (United States)

    Stanković, Koviljka; Brajović, Dragan; Alimpijević, Mališa; Lončar, Boris

    2016-07-01

    The aim of this paper is to identify parameters that influence the long-term deconditioning effect of gas-filled surge arrester (GFSA) and to provide practical recommendations for mitigating this effect. Namely, after some period of time, on order of hours or days, during which there is no activation due to overvoltage, the deconditioning of GFSA occurs. This effect was observed experimentally within the paper. The observed parameters that could influence the long-term deconditioning effect were the following: shape of voltage load, gas type, gas pressure, interelectrode distance, electrode material, electrode surface topography as well as GFSA design such as two- or three-electrode configuration. According to the results obtained, it has been shown that the occurrence of long-term deconditioning in an insulating system, insulated by a noble gas at a subpressure and with small interelectrode distances, is a phenomenon that always occurs when the insulating system is at rest for about an hour. It has been found that the type of noble gas does not influence the long-term deconditioning. Analysis of such insulating systems' parameters, with a prospect of being used as GFSAs, has demonstrated that this phenomenon is less pronounced at higher pressures (for the same value of the pressure (p) and interelectrode distance (d) product) and for electrodes with microscopically embossed surfaces. According to the results that were obtained by noble gases and their mixtures, as well as the results that were obtained by mixtures of SF6 gas with noble gasses, it can be claimed with confidence that the effect of the long-term deconditioning is an electrode effect. It has also been established that the deconditioning effect does not depend on the electrode material except in the case of electrodes made out of noble metals, which reduce the effect. Based on these results, it can be recommended that the working point of GFSAs be set (according to the DC breakdown voltage value) at a

  10. [Analysis of articles published in Chin J Surg since founded in 1951].

    Science.gov (United States)

    Xia, Shuang; Li, Jing

    2016-01-01

    To discuss the characteristics of the articles published in Chin J Surg from 1951 to 2015. The journals and articles of Acad Surg from 1951 to 1952 and Chin J Surg from 1953 to 2015 were analyzed. The subjects, foundation, basic medical study, international cooperation of the articles were recorded. In 65 years, there were 20 090 academic articles published in Chin J Surg. The proportions of general surgery, orthopedic surgery, thoracocardiac surgery, urology surgery and neurosurgery articles were 34.08%, 17.96%, 13.09%, 11.91% and 5.85%, respectively. There were 14.83% (1 728/11 653) articles receiving foundation, and 9.42% (1 817/19 290) articles reporting basic medical study. There were 14.8% articles from international authors and 119 articles with international cooperation. From 2000 to 2003, 29 articles in original English were published. The coverage of Chin J Surg contains all the fields of surgery. It tends to publish the studies focus on clinical issues.Through reinforcing the content plan and optimizing the show form, the more Chinese surgical research achievements could be shared by the surgeons worldwide.

  11. Assessment of surge arrester failure rate and application studies in Hellenic high voltage transmission lines

    Energy Technology Data Exchange (ETDEWEB)

    Christodoulou, C.A.; Fotis, G.P.; Gonos, I.F.; Stathopulos, I.A. [National Technical University of Athens, School of Electrical and Computer Engineering, High Voltage Laboratory, 9 Iroon Politechniou St., Zografou Campus, 157 80 Athens (Greece); Ekonomou, L. [A.S.PE.T.E. - School of Pedagogical and Technological Education, Department of Electrical Engineering Educators, N. Heraklion, 141 21 Athens (Greece)

    2010-02-15

    The use of transmission line surge arresters to improve the lightning performance of transmission lines is becoming more common. Especially in areas with high soil resistivity and ground flash density, surge arresters constitute the most effective protection mean. In this paper a methodology for assessing the surge arrester failure rate based on the electrogeometrical model is presented. Critical currents that exceed arresters rated energy stress were estimated by the use of a simulation tool. The methodology is applied on operating Hellenic transmission lines of 150 kV. Several case studies are analyzed by installing surge arresters on different intervals, in relation to the region's tower footing resistance and the ground flash density. The obtained results are compared with real records of outage rate showing the effectiveness of the surge arresters in the reduction of the recorded failure rate. The presented methodology can be proved valuable to the studies of electric power systems designers intending in a more effective lightning protection, reducing the operational costs and providing continuity of service. (author)

  12. A new on-line leakage current monitoring system of ZnO surge arresters

    International Nuclear Information System (INIS)

    Lee, Bok-Hee; Kang, Sung-Man

    2005-01-01

    This paper presents a new on-line leakage current monitoring system of zinc oxide (ZnO) surge arresters. To effectively diagnose the deterioration of ZnO surge arresters, a new algorithm and on-line leakage current detection device, which uses the time-delay addition method, for discriminating the resistive and capacitive currents was developed to use in the aging test and durability evaluation for ZnO arrester blocks. A computer-based measurement system of the resistive leakage current, the on-line monitoring device can detect accurately the leakage currents flowing through ZnO surge arresters for power frequency ac applied voltages. The proposed on-line leakage current monitoring device of ZnO surge arresters is more highly sensitive and gives more linear response than the existing devices using the detection method of the third harmonic leakage currents. Therefore, the proposed leakage current monitoring device can be useful for predicting the defects and performance deterioration of ZnO surge arresters in power system applications

  13. Adriatic storm surges and related cross-basin sea-level slope

    Science.gov (United States)

    Međugorac, Iva; Orlić, Mirko; Janeković, Ivica; Pasarić, Zoran; Pasarić, Miroslava

    2018-05-01

    Storm surges pose a severe threat to the northernmost cities of the Adriatic coast, with Venice being most prone to flooding. It has been noted that some flooding episodes cause significantly different effects along the eastern and western Adriatic coasts, with indications that the difference is related to cross-basin sea-level slope. The present study aims to determine specific atmospheric conditions under which the slope develops and to explore connection with increased sea level along the two coastlines. The analysis is based on sea-level time series recorded at Venice and Bakar over the 1984-2014 interval, from which 38 most intensive storm-surge episodes were selected, and their meteorological backgrounds (ERA-Interim) were studied. The obtained sea-level extremes were grouped into three categories according to their cross-basin sea-level slope: storm surges that slope strongly westward (W type), those that slope eastward (E type) and ordinary storm surges (O type). Results show that the slope is controlled by wind action only, specifically, by the wind component towards a particular coast and by the cross-basin shear of along-basin wind. Meteorological fields were used to force an oceanographic numerical model in order to confirm the empirically established connection between the atmospheric forcing and the slope. Finally, it has been found that the intensity of storm surges along a particular Adriatic coast is determined by an interplay of sea-level slopes in the along and cross-basin directions.

  14. Parameter sensitivity and uncertainty analysis for a storm surge and wave model

    Directory of Open Access Journals (Sweden)

    L. A. Bastidas

    2016-09-01

    Full Text Available Development and simulation of synthetic hurricane tracks is a common methodology used to estimate hurricane hazards in the absence of empirical coastal surge and wave observations. Such methods typically rely on numerical models to translate stochastically generated hurricane wind and pressure forcing into coastal surge and wave estimates. The model output uncertainty associated with selection of appropriate model parameters must therefore be addressed. The computational overburden of probabilistic surge hazard estimates is exacerbated by the high dimensionality of numerical surge and wave models. We present a model parameter sensitivity analysis of the Delft3D model for the simulation of hazards posed by Hurricane Bob (1991 utilizing three theoretical wind distributions (NWS23, modified Rankine, and Holland. The sensitive model parameters (of 11 total considered include wind drag, the depth-induced breaking γB, and the bottom roughness. Several parameters show no sensitivity (threshold depth, eddy viscosity, wave triad parameters, and depth-induced breaking αB and can therefore be excluded to reduce the computational overburden of probabilistic surge hazard estimates. The sensitive model parameters also demonstrate a large number of interactions between parameters and a nonlinear model response. While model outputs showed sensitivity to several parameters, the ability of these parameters to act as tuning parameters for calibration is somewhat limited as proper model calibration is strongly reliant on accurate wind and pressure forcing data. A comparison of the model performance with forcings from the different wind models is also presented.

  15. Catastrophe loss modelling of storm-surge flood risk in eastern England.

    Science.gov (United States)

    Muir Wood, Robert; Drayton, Michael; Berger, Agnete; Burgess, Paul; Wright, Tom

    2005-06-15

    Probabilistic catastrophe loss modelling techniques, comprising a large stochastic set of potential storm-surge flood events, each assigned an annual rate of occurrence, have been employed for quantifying risk in the coastal flood plain of eastern England. Based on the tracks of the causative extratropical cyclones, historical storm-surge events are categorized into three classes, with distinct windfields and surge geographies. Extreme combinations of "tide with surge" are then generated for an extreme value distribution developed for each class. Fragility curves are used to determine the probability and magnitude of breaching relative to water levels and wave action for each section of sea defence. Based on the time-history of water levels in the surge, and the simulated configuration of breaching, flow is time-stepped through the defences and propagated into the flood plain using a 50 m horizontal-resolution digital elevation model. Based on the values and locations of the building stock in the flood plain, losses are calculated using vulnerability functions linking flood depth and flood velocity to measures of property loss. The outputs from this model for a UK insurance industry portfolio include "loss exceedence probabilities" as well as "average annualized losses", which can be employed for calculating coastal flood risk premiums in each postcode.

  16. Countercurrent Air-Water Flow in a Scale-Down Model of a Pressurizer Surge Line

    Directory of Open Access Journals (Sweden)

    Takashi Futatsugi

    2012-01-01

    Full Text Available Steam generated in a reactor core and water condensed in a pressurizer form a countercurrent flow in a surge line between a hot leg and the pressurizer during reflux cooling. Characteristics of countercurrent flow limitation (CCFL in a 1/10-scale model of the surge line were measured using air and water at atmospheric pressure and room temperature. The experimental results show that CCFL takes place at three different locations, that is, at the upper junction, in the surge line, and at the lower junction, and its characteristics are governed by the most dominating flow limitation among the three. Effects of inclination angle and elbows of the surge line on CCFL characteristics were also investigated experimentally. The effects of inclination angle on CCFL depend on the flow direction, that is, the effect is large for the nearly horizontal flow and small for the vertical flow at the upper junction. The presence of elbows increases the flow limitation in the surge line, whereas the flow limitations at the upper and lower junctions do not depend on the presence of elbows.

  17. Rapid wave and storm surge warning system for tropical cyclones in Mexico

    Science.gov (United States)

    Appendini, C. M.; Rosengaus, M.; Meza, R.; Camacho, V.

    2015-12-01

    The National Hurricane Center (NHC) in Miami, is responsible for the forecast of tropical cyclones in the North Atlantic and Eastern North Pacific basins. As such, Mexico, Central America and Caribbean countries depend on the information issued by the NHC related to the characteristics of a particular tropical cyclone and associated watch and warning areas. Despite waves and storm surge are important hazards for marine operations and coastal dwellings, their forecast is not part of the NHC responsibilities. This work presents a rapid wave and storm surge warning system based on 3100 synthetic tropical cyclones doing landfall in Mexico. Hydrodynamic and wave models were driven by the synthetic events to create a robust database composed of maximum envelops of wind speed, significant wave height and storm surge for each event. The results were incorporated into a forecast system that uses the NHC advisory to locate the synthetic events passing inside specified radiuses for the present and forecast position of the real event. Using limited computer resources, the system displays the information meeting the search criteria, and the forecaster can select specific events to generate the desired hazard map (i.e. wind, waves, and storm surge) based on the maximum envelop maps. This system was developed in a limited time frame to be operational in 2015 by the National Hurricane and Severe Storms Unit of the Mexican National Weather Service, and represents a pilot project for other countries in the region not covered by detailed storm surge and waves forecasts.

  18. Elevation Change, Mass Balance, Dynamics, and Surging of Langjökull, Iceland from 1997 to 2007

    OpenAIRE

    Pope, Allen; Willis, Ian Craig; Pálsson, Finnur; Arnold, Neil Stuart; Rees, William Gareth; Björnsson, Helgi; Grey, Lauren

    2016-01-01

    Glaciers and ice caps around the world are changing quickly, with surge-type behaviour superimposed upon climatic forcing. Here, we study Iceland’s second largest ice cap, Langjökull, which has both surge- and non-surge-type outlets. By differencing elevation change with surface mass balance, we estimate the contribution of ice dynamics to elevation change. We use DEMs, in situ stake measurements, regional reanalyses, and a mass balance model to calculate the vertical ice velocity. Thus,...

  19. Regulation of LH/FSH expression by secretoglobin 3A2 in the mouse pituitary gland.

    Science.gov (United States)

    Miyano, Yuki; Tahara, Shigeyuki; Sakata, Ichiro; Sakai, Takafumi; Abe, Hiroyuki; Kimura, Shioko; Kurotani, Reiko

    2014-04-01

    Secretoglobin (SCGB) 3A2 was originally identified as a downstream target for the homeodomain transcription factor NKX2-1 in the lung. NKX2-1 plays a role in the genesis and expression of genes in the thyroid, lung and ventral forebrain; Nkx2-1-null mice have no thyroid and pituitary and severely hypoplastic lungs and hypothalamus. To demonstrate whether SCGB3A2 plays any role in pituitary hormone production, NKX2-1 and SCGB3A2 expression in the mouse pituitary gland was examined by immunohistochemical analysis and RT-PCR. NKX2-1 was localized in the posterior pituitary lobe, whereas SCGB3A2 was observed in both anterior and posterior lobes as shown by immunohistochemistry and RT-PCR. Expression of CCAAT-enhancer binding proteins (C/EBPs), which regulate mouse Scgb3a2 transcription, was also examined by RT-PCR. C/EBPβ, γ, δ and ζ were expressed in the adult mouse pituitary gland. SCGB3A2 was expressed in the anterior and posterior lobes from postnatal days 1 and 5, respectively and the areas where SCGB3A2 expression was found coincided with the area where FSH-secreting cells were found. Double-staining for SCGB3A2 and pituitary hormones revealed that SCGB3A2 was mainly localized in gonadotrophs in 49 % of FSH-secreting cells and 47 % of LH-secreting cells. In addition, SCGB3A2 dramatically inhibited LH and FSH mRNA expression in rat pituitary primary cell cultures. These results suggest that SCGB3A2 regulates FSH/LH production in the anterior pituitary lobe and that transcription factors other than NKX2-1 may regulate SCGB3A2 expression.

  20. Dietary lipid and cholesterol induce ovarian dysfunction and abnormal LH response to stimulation in rabbits.

    Directory of Open Access Journals (Sweden)

    Anne-Gaël Cordier

    Full Text Available BACKGROUND/AIM: Excess of fat intake is dramatically increasing in women of childbearing age and results in numerous health complications, including reproductive disorders. Using rabbit does as a biomedical model, the aim of this study was to evaluate onset of puberty, endocrine responses to stimulation and ovarian follicular maturation in females fed a high fat high cholesterol diet (HH diet from 10 weeks of age (i.e., 2 weeks before normal onset of puberty or a control diet (C diet. METHODOLOGY/PRINCIPAL FINDINGS: Three experiments were performed, each including 8 treated (HH group and 8 control (C group does. In experiment 1, the endocrine response to Gonadotropin releasing hormone (GnRH was evaluated at 13, 18 and 22 weeks of age. In experiment 2, the follicular population was counted in ovaries of adult females (18 weeks of age. In experiment 3, the LH response to mating and steroid profiles throughout gestation were evaluated at 18 weeks of age. Fetal growth was monitored by ultrasound and offspring birth weight was recorded. Data showed a significantly higher Luteinizing hormone (LH response after induction of ovulation at 13 weeks of age in the HH group. There was no difference at 18 weeks, but at 22 weeks, the LH response to GnRH was significantly reduced in the HH group. The number of atretic follicles was significantly increased and the number of antral follicles significantly reduced in HH does vs. controls. During gestation, the HH diet induced intra-uterine growth retardation (IUGR. CONCLUSION: The HH diet administered from before puberty onwards affected onset of puberty, follicular growth, hormonal responses to breeding and GnRH stimulation in relation to age and lead to fetal IUGR.

  1. Prenatal testosterone treatment alters LH and testosterone responsiveness to GnRH agonist in male sheep

    Directory of Open Access Journals (Sweden)

    SERGIO E RECABARREN

    2007-01-01

    Full Text Available Although evidence is accumulating that prenatal testosterone (T compromises reproductive function in the female, the effects of excess T in utero on the postnatal development of male reproductive function has not been studied. The aim of this study was to assess the influence of prenatal T excess on age-related changes in pituitary and gonadal responsiveness to GnRH in the male sheep. We used the GnRH agonist, leuprolide (10 µg/kg, as a pharmacologic challenge at 5, 10, 20 and 30 weeks of age. These time points correspond to early and late juvenile periods and the prepubertal and postpubertal periods of sexual development, respectively. LH and T were measured in blood samples collected before and after GnRH agonist administration. The area under the response curve (AUC of LH increased progressively in both controls and prenatal T-treated males from 5 to 20 weeks of age (P<0.01. The LH responses in prenatal T-treated males were lower at 20 and 30 weeks of age compared to controls (P<0.05. AUC-T increased progressively in control males from 5 through 30 weeks of age and prenatal T-treated males from 5 to 20 weeks of age. The T response in prenatal T-treated males was higher at 20 weeks compared to controls of same age but similar to controls and prenatal T-treated males at 30 weeks of age (P <0.05. Our findings suggest that prenatal T treatment advances the developmental trajectory of gonadal responsiveness to GnRH in male offspring

  2. Mechanized Sephadex LH-20 multiple column chromatography as a prerequisite for automated multi-steroid radioimmunoassays

    International Nuclear Information System (INIS)

    Sippell, W.G.; Bidlingmaier, F.; Knorr, D.

    1978-01-01

    To establish a procedure for the simultaneous determination of all major corticosteroid hormones and their immediate biological precursors in the same plasma sample, two different mechanized methods for the simultaneous isolation of aldosterone (A), corticosterone (B), 11-deoxycorticosterone (DOC), progesterone (P), 17-hydroxyprogesterone (17-OHP), 11-deoxycortisol (S), cortisol (F) and cortisone (E) from the methylene chloride extracts of 0.1 to 2.0ml plasma samples have been developed. In method I, steroids are separated with methylene chloride:methanol=98:2 as solvent system on 60-cm Sephadex LH-20 columns, up to eight of which are eluted in parallel using a multi-channel peristaltic pump and individual flow-rate control (40ml/h) by capillary valves and micro-flowmeters. Method II, on the other hand, utilizes the same solvent system on ten 75-cm LH-20 columns which are eluted in reversed flow simultaneously by a ten-channel, double-piston pump that precisely maintains an elution flow rate of 40ml/h in every column. In both methods, eluate fractions of each of the isolated steroids are automatically pooled and collected from all parallel columns by one programmable linear fraction collector. As a result of the high reproducibility of the elution patterns, both between different parallel columns and between 30 to 40 consecutive elutions, mean recoveries of tritiated steroids including extraction are 60 to 84% after a single separation and still over 50% after an additional separation on 40-cm LH-20 columns, with coefficients of variation below 15% (method II). Thus, the eight steroids can be completely isolated from each of ten plasma extracts within 3 to 4 hours, yielding 80 samples readily prepared for subsequent quantitation by radioimmunoassay. (author)

  3. Self-trapped excitons in LH2 bacteriochlorophyll-protein complexes under high pressure

    International Nuclear Information System (INIS)

    Timpmann, K.; Ellervee, Aleksandr; Kuznetsov, Anatoli; Laisaar, Arlentin; Trinkunas, Gediminas; Freiberg, Arvi

    2003-01-01

    The absorption and emission spectra of excitons in LH2 antenna complexes from the photosynthetic purple bacterium Rhodobacter sphaeroides have been studied under hydrostatic pressure. The measurements made between ambient pressure and 6 kbar over a broad temperature range reveal largely different rates of the pressure-induced shifts for the absorption and emission bands. Numerical calculations based on exciton polaron model provide evidence for the exciton self-trapping at ambient pressure as well as for the pressure stabilization of the self-trapped exciton states responsible for the emission, whereas the light absorbing states belong to nearly free excitons over the whole pressure and temperature ranges studied

  4. LOX/LH2 propulsion system for launch vehicle upper stage, test results

    Science.gov (United States)

    Ikeda, T.; Imachi, U.; Yuzawa, Y.; Kondo, Y.; Miyoshi, K.; Higashino, K.

    1984-01-01

    The test results of small LOX/LH2 engines for two propulsion systems, a pump fed system and a pressure fed system are reported. The pump fed system has the advantages of higher performances and higher mass fraction. The pressure fed system has the advantages of higher reliability and relative simplicity. Adoption of these cryogenic propulsion systems for upper stage of launch vehicle increases the payload capability with low cost. The 1,000 kg thrust class engine was selected for this cryogenic stage. A thrust chamber assembly for the pressure fed propulsion system was tested. It is indicated that it has good performance to meet system requirements.

  5. Validation of the LH antenna code ALOHA against Tore Supra experiments

    International Nuclear Information System (INIS)

    Hillairet, J.; Ekedahl, A.; Kocan, M.; Gunn, J. P.; Goniche, M.

    2009-01-01

    Comparisons between ALOHA code predictions and experimental measurements of reflection coefficients for the two different Lower Hybrid Current Drive (LHCD) antennas (named C2 and C3) in Tore Supra are presented. A large variation of density in front of the antennas was obtained by varying the distance between the plasma and the antennas. Low power ( 2 ) was used in order to avoid non-linear effects on the wave coupling. Results obtained with ALOHA are in good agreement with the experimental measurements for both Tore Supra antennas and show that ALOHA is an efficient LH predictive tool.

  6. Statistical theory of L-H transition and its implication to threshold database

    International Nuclear Information System (INIS)

    Itoh, S.-I.; Itoh, K.; Toda, S.

    2003-01-01

    A statistical model for the bifurcation of the radial electric field E r is analyzed in view of describing L-H transitions of toroidal plasmas. Noise in micro fluctuations is shown to lead to random changes of E r , if a deterministic approach allows for more than one solution. The probability density function for and the ensemble average of E r are obtained. The L-to-H and the H-to-L transition probabilities are calculated, and the effective phase limit is derived. Due to the suppression of turbulence by shear in E r , the limit deviates from Maxwell's rule. (author)

  7. Turbulence simulations of X point physics on the L-H transitions

    International Nuclear Information System (INIS)

    Xu, X.Q.; Cohen, R.H.; Nevins, W.M.

    2001-01-01

    We show that the resistive X-point mode is the dominant mode in boundary plasmas in X-point divertor geometry. The poloidal fluctuation phase velocity from the simulation results of the resistive X-point turbulence shows experimentally measured structure across separatrix in many fusion devices. The fluctuation phase velocity is larger than ExB velocity both in L and H mode phases. We also demonstrate that there is a strong poloidal asymmetry of particle flux in the proximity of the separatrix. Turbulence suppression in the L-H transition results when sources of energy and particles drive sufficient gradients as in the experiments. (author)

  8. L-H power threshold studies with tungsten/carbon divertor on the EAST tokamak

    DEFF Research Database (Denmark)

    Chen, L.; Xu, G. S.; Gao, W.

    2016-01-01

    The power threshold for low (L) to high (H) confinement mode transition achieved by radio-frequency heating and molybdenum first wall with lithium coating has been experimentally investigated on the EAST tokamak for two sets of divertor geometries and materials: tungsten/carbon divertor and full...... carbon divertor. For both sets of divertors, the power threshold was found to decrease with gradual accumulation of the lithium wall coating, suggesting the important role played by the low Z impurities and/or the edge neutral density on the L-H power threshold. When operating in the upper single null...

  9. Risks of Coastal Storm Surge and the Effect of Sea Level Rise in the Red River Delta, Vietnam

    OpenAIRE

    Neumann, James; Ludwig, Lindsay; Verly, Caroleen; Emanuel, Kerry Andrew; Ravela, Srinivas

    2015-01-01

    This paper considers the impact of sea level rise and storm surge on the Red River delta region of Vietnam an area already known to be highly vulnerable to coastal risks. By combining a range of sea level rise scenarios for 2050 with the simulated storm surge level for the 100-year storm surge, we analyze permanently inundated lands and temporary flood zones. As is well-established in the literature, sea level rise will increase the risk of storms by raising the base sea level from which surg...

  10. Machine characteristics, system arrangement, driver and operation effects on surge of dynamic compressor in oil and gas plants

    Energy Technology Data Exchange (ETDEWEB)

    Almasi, Amin

    2012-12-15

    Working in the surge area will result in an unstable compressor operation, exposing the dynamic compressor (centrifugal compressor or axial compressor) to destructive stress, high vibration and other damaging effects. The destructive power of the surge is enormous, ranging from changes in clearances, which result in a penalty in the compressor efficiency, to destruction of parts leading to bearing, rotor or seal replacements. The effects of compressor characteristics, driver type, compressor accessories, vent valve, check valve, trip delay and operation details on surge events and anti-surge system designs are studied. A case study is also discussed. (orig.)

  11. A comparison between r-LH and urinary supplements containing LH activity in patients undergoing the microdose GnRH agonist flare protocol for in-vitro fertilization: a pilot study.

    Science.gov (United States)

    Shavit, Tal; Agdi, Mohammed; Son, Weon Y; Hasson, Josseph; Dahan, Michael H

    2016-08-01

    The aim of this study was to compare pregnancy rates and stimulation parameters in patients with diminished ovarian reserve, who were treated with recombinant human luteinizing hormone (r-LH) or menopausal gonadotropins (hMG), as part of a microdose flare protocol. A retrospective cohort study was performed. Comparisons between the group that was stimulated with r-LH plus follicle stimulating hormone (FSH) to those treated with hMG and FSH, were performed. Measurements included: medication doses, number of oocyte collected, number of embryos obtained, pregnancy and clinical pregnancy rates. Patients in the r-LH group (N.=40) had significant higher clinical pregnancy rates (33% vs. 14%; P=0.04) and used lower dose of LH (1938 IU vs. 2807 IU; P=0.02) compared to patients that were stimulated with hMG (N.=39). r-LH may offer advantages for the treatment of diminished ovarian reserve when performing a microdose flare protocol when compared to hMG. Both larger and prospective studies should be carried out to confirm these findings.

  12. An Exploration of Wind Stress Calculation Techniques in Hurricane Storm Surge Modeling

    Directory of Open Access Journals (Sweden)

    Kyra M. Bryant

    2016-09-01

    Full Text Available As hurricanes continue to threaten coastal communities, accurate storm surge forecasting remains a global priority. Achieving a reliable storm surge prediction necessitates accurate hurricane intensity and wind field information. The wind field must be converted to wind stress, which represents the air-sea momentum flux component required in storm surge and other oceanic models. This conversion requires a multiplicative drag coefficient for the air density and wind speed to represent the air-sea momentum exchange at a given location. Air density is a known parameter and wind speed is a forecasted variable, whereas the drag coefficient is calculated using an empirical correlation. The correlation’s accuracy has brewed a controversy of its own for more than half a century. This review paper examines the lineage of drag coefficient correlations and their acceptance among scientists.

  13. A parabolic model of drag coefficient for storm surge simulation in the South China Sea

    Science.gov (United States)

    Peng, Shiqiu; Li, Yineng

    2015-01-01

    Drag coefficient (Cd) is an essential metric in the calculation of momentum exchange over the air-sea interface and thus has large impacts on the simulation or forecast of the upper ocean state associated with sea surface winds such as storm surges. Generally, Cd is a function of wind speed. However, the exact relationship between Cd and wind speed is still in dispute, and the widely-used formula that is a linear function of wind speed in an ocean model could lead to large bias at high wind speed. Here we establish a parabolic model of Cd based on storm surge observations and simulation in the South China Sea (SCS) through a number of tropical cyclone cases. Simulation of storm surges for independent Tropical cyclones (TCs) cases indicates that the new parabolic model of Cd outperforms traditional linear models. PMID:26499262

  14. On Active Surge Control of Compression Systems via Characteristic Linearization and Model Nonlinearity Cancellation

    Directory of Open Access Journals (Sweden)

    Yohannes S.M. Simamora

    2014-09-01

    Full Text Available A simple approach of active surge control of compression systems is presented. Specifically, nonlinear components of the pressure ratio and rotating speed states of the Moore-Greitzer model are transferred into the input vectors. Subsequently, the compressor characteristic is linearized into two modes, which describe the stable region and the unstable region respectively. As a result, the system’s state and input matrices both appear linear, to which linear realization and analysis are applicable. A linear quadratic regulator plus integrator is then chosen as closed-loop controller. By simulation it was shown that the modified model and characteristics can describe surge behavior, while the closed-loop controller can stabilize the system in the unstable operating region. The last-mentioned was achieved when massflow was 5.38 per cent less than the surge point.

  15. Adjusting the Parameters of Metal Oxide Gapless Surge Arresters’ Equivalent Circuits Using the Harmony Search Method

    Directory of Open Access Journals (Sweden)

    Christos A. Christodoulou

    2017-12-01

    Full Text Available The appropriate circuit modeling of metal oxide gapless surge arresters is critical for insulation coordination studies. Metal oxide arresters present a dynamic behavior for fast front surges; namely, their residual voltage is dependent on the peak value, as well as the duration of the injected impulse current, and should therefore not only be represented by non-linear elements. The aim of the current work is to adjust the parameters of the most frequently used surge arresters’ circuit models by considering the magnitude of the residual voltage, as well as the dissipated energy for given pulses. In this aim, the harmony search method is implemented to adjust parameter values of the arrester equivalent circuit models. This functions by minimizing a defined objective function that compares the simulation outcomes with the manufacturer’s data and the results obtained from previous methodologies.

  16. Storm surges-An option for Hamburg, Germany, to mitigate expected future aggravation of risk

    International Nuclear Information System (INIS)

    Storch, Hans von; Goennert, Gabriele; Meine, Manfred

    2008-01-01

    Summary: Rising sea level together with regionally increased storm activity, caused by elevated and increasing levels of greenhouse gases in the atmosphere will in many parts of the world increase the risk of storm surges significantly. Reducing the emissions of greenhouse gases into the atmosphere may mitigate the increasing risks somewhat, but the major task for regional and local stakeholders will be to prepare for appropriate adaptation. In most cases, possible strategies include intensification of coastal defense measures, in particular strengthening dykes, and adaptation to intermittent flooding. In case of Hamburg and the tidal Elbe river a third option seems to be available, which aims at mitigating storm surge risks by applying estuary engineering constructions. This option is sketched in this paper. The option has the potential to significantly reduce the expected future increases of local surge heights

  17. A parabolic model of drag coefficient for storm surge simulation in the South China Sea

    Science.gov (United States)

    Peng, Shiqiu; Li, Yineng

    2015-10-01

    Drag coefficient (Cd) is an essential metric in the calculation of momentum exchange over the air-sea interface and thus has large impacts on the simulation or forecast of the upper ocean state associated with sea surface winds such as storm surges. Generally, Cd is a function of wind speed. However, the exact relationship between Cd and wind speed is still in dispute, and the widely-used formula that is a linear function of wind speed in an ocean model could lead to large bias at high wind speed. Here we establish a parabolic model of Cd based on storm surge observations and simulation in the South China Sea (SCS) through a number of tropical cyclone cases. Simulation of storm surges for independent Tropical cyclones (TCs) cases indicates that the new parabolic model of Cd outperforms traditional linear models.

  18. Experimental Study on Active Control of Surge in a Centrifugal Compression System

    Directory of Open Access Journals (Sweden)

    Nie Chaoqun

    2000-01-01

    Full Text Available An experimental study has been carried out on the active control of surge in a centrifugal compression system. With a computerized on-line control scheme, the surge phenomenon is suppressed and the stable operating range of the system is extended. In order to design the active control scheme and choose the desired parameters of the control system inputs, special emphases have been placed on the development of surge inception and the nonlinear interaction between the system and the actuator. By use of the method designed in the present work, the results of active control onsurge have been demonstrated for the different B parameters, different prescribed criteria and different control frequencies.

  19. Passive seismic monitoring of the Bering Glacier during its last surge event

    Science.gov (United States)

    Zhan, Z.

    2017-12-01

    The physical causes behind glacier surges are still unclear. Numerous evidences suggest that they probably involve changes in glacier basal conditions, such as switch of basal water system from concentrated large tunnels to a distributed "layer" as "connected cavities". However, most remote sensing approaches can not penetrate to the base to monitor such changes continuously. Here we apply seismic interferometry using ambient noise to monitor glacier seismic structures, especially to detect possible signatures of the hypothesized high-pressure water "layer". As an example, we derive an 11-year long history of seismic structure of the Bering Glacier, Alaska, covering its latest surge event. We observe substantial drops of Rayleigh and Love wavespeeds across the glacier during the surge event, potentially caused by changes in crevasse density, glacier thickness, and basal conditions.

  20. Dynamic Model of Centrifugal Compressor for Prediction of Surge Evolution and Performance Variations

    International Nuclear Information System (INIS)

    Jung, Mooncheong; Han, Jaeyoung; Yu, Sangseok

    2016-01-01

    When a control algorithm is developed to protect automotive compressor surges, the simulation model typically selects an empirically determined look-up table. However, it is difficult for a control oriented empirical model to show surge characteristics of the super charger. In this study, a dynamic supercharger model is developed to predict the performance of a centrifugal compressor under dynamic load follow-up. The model is developed using Simulink® environment, and is composed of a compressor, throttle body, valves, and chamber. Greitzer’s compressor model is used, and the geometric parameters are achieved by the actual supercharger. The simulation model is validated with experimental data. It is shown that compressor surge is effectively predicted by this dynamic compressor model under various operating conditions.

  1. Dynamic Model of Centrifugal Compressor for Prediction of Surge Evolution and Performance Variations

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Mooncheong; Han, Jaeyoung; Yu, Sangseok [Chungnam National Univ., Daejeon (Korea, Republic of)

    2016-05-15

    When a control algorithm is developed to protect automotive compressor surges, the simulation model typically selects an empirically determined look-up table. However, it is difficult for a control oriented empirical model to show surge characteristics of the super charger. In this study, a dynamic supercharger model is developed to predict the performance of a centrifugal compressor under dynamic load follow-up. The model is developed using Simulink® environment, and is composed of a compressor, throttle body, valves, and chamber. Greitzer’s compressor model is used, and the geometric parameters are achieved by the actual supercharger. The simulation model is validated with experimental data. It is shown that compressor surge is effectively predicted by this dynamic compressor model under various operating conditions.

  2. Parameter identification of ZnO surge arrester models based on genetic algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Bayadi, Abdelhafid [Laboratoire d' Automatique de Setif, Departement d' Electrotechnique, Faculte des Sciences de l' Ingenieur, Universite Ferhat ABBAS de Setif, Route de Bejaia Setif 19000 (Algeria)

    2008-07-15

    The correct and adequate modelling of ZnO surge arresters characteristics is very important for insulation coordination studies and systems reliability. In this context many researchers addressed considerable efforts to the development of surge arresters models to reproduce the dynamic characteristics observed in their behaviour when subjected to fast front impulse currents. The difficulties with these models reside essentially in the calculation and the adjustment of their parameters. This paper proposes a new technique based on genetic algorithm to obtain the best possible series of parameter values of ZnO surge arresters models. The validity of the predicted parameters is then checked by comparing the predicted results with the experimental results available in the literature. Using the ATP-EMTP package, an application of the arrester model on network system studies is presented and discussed. (author)

  3. The analysis of dependence between extreme rainfall and storm surge in the coastal zone

    Science.gov (United States)

    Zheng, F.; Westra, S.

    2012-12-01

    Flooding in coastal catchments can be caused by runoff generated by an extreme rainfall event, elevated sea levels due to an extreme storm surge event, or the combination of both processes occurring simultaneously or in close succession. Dependence in extreme rainfall and storm surge arises because common meteorological forcings often drive both variables; for example, cyclonic systems may produce extreme rainfall, strong onshore winds and an inverse barometric effect simultaneously, which the former factor influencing catchment discharge and the latter two factors influencing storm surge. Nevertheless there is also the possibility that only one of the variables is extreme at any given time, so that the dependence between rainfall and storm surge is not perfect. Quantification of the strength of dependence between these processes is critical in evaluating the magnitude of flood risk in the coastal zone. This may become more important in the future as the majority of the coastal areas are threatened by the sea level rise due to the climate change. This research uses the most comprehensive record of rainfall and storm surge along the coastline of Australia collected to-date to investigate the strength of dependence between the extreme rainfall and storm surge along the Australia coastline. A bivariate logistic threshold-excess model was employed to this end to carry out the dependence analysis. The strength of the estimated dependence is then evaluated as a function of several factors including: the distance between the tidal gauge and the rain gauge; the lag between the extreme precipitation event and extreme surge event; and the duration of the maximum storm burst. The results show that the dependence between the extreme rainfall and storm surge along the Australia coastline is statistically significant, although some locations clearly exhibit stronger dependence than others. We hypothesize that this is due to a combination of large-scale meteorological effects as

  4. Automating Flood Hazard Mapping Methods for Near Real-time Storm Surge Inundation and Vulnerability Assessment

    Science.gov (United States)

    Weigel, A. M.; Griffin, R.; Gallagher, D.

    2015-12-01

    Storm surge has enough destructive power to damage buildings and infrastructure, erode beaches, and threaten human life across large geographic areas, hence posing the greatest threat of all the hurricane hazards. The United States Gulf of Mexico has proven vulnerable to hurricanes as it has been hit by some of the most destructive hurricanes on record. With projected rises in sea level and increases in hurricane activity, there is a need to better understand the associated risks for disaster mitigation, preparedness, and response. GIS has become a critical tool in enhancing disaster planning, risk assessment, and emergency response by communicating spatial information through a multi-layer approach. However, there is a need for a near real-time method of identifying areas with a high risk of being impacted by storm surge. Research was conducted alongside Baron, a private industry weather enterprise, to facilitate automated modeling and visualization of storm surge inundation and vulnerability on a near real-time basis. This research successfully automated current flood hazard mapping techniques using a GIS framework written in a Python programming environment, and displayed resulting data through an Application Program Interface (API). Data used for this methodology included high resolution topography, NOAA Probabilistic Surge model outputs parsed from Rich Site Summary (RSS) feeds, and the NOAA Census tract level Social Vulnerability Index (SoVI). The development process required extensive data processing and management to provide high resolution visualizations of potential flooding and population vulnerability in a timely manner. The accuracy of the developed methodology was assessed using Hurricane Isaac as a case study, which through a USGS and NOAA partnership, contained ample data for statistical analysis. This research successfully created a fully automated, near real-time method for mapping high resolution storm surge inundation and vulnerability for the

  5. Estimating Areas of Vulnerability: Sea Level Rise and Storm Surge Hazards in the National Parks

    Science.gov (United States)

    Caffrey, M.; Beavers, R. L.; Slayton, I. A.

    2013-12-01

    The University of Colorado Boulder in collaboration with the National Park Service has undertaken the task of compiling sea level change and storm surge data for 105 coastal parks. The aim of our research is to highlight areas of the park system that are at increased risk of rapid inundation as well as periodic flooding due to sea level rise and storms. This research will assist park managers and planners in adapting to climate change. The National Park Service incorporates climate change data into many of their planning documents and is willing to implement innovative coastal adaptation strategies. Events such as Hurricane Sandy highlight how impacts of coastal hazards will continue to challenge management of natural and cultural resources and infrastructure along our coastlines. This poster will discuss the current status of this project. We discuss the impacts of Hurricane Sandy as well as the latest sea level rise and storm surge modeling being employed in this project. In addition to evaluating various drivers of relative sea-level change, we discuss how park planners and managers also need to consider projected storm surge values added to sea-level rise magnitudes, which could further complicate the management of coastal lands. Storm surges occurring at coastal parks will continue to change the land and seascapes of these areas, with the potential to completely submerge them. The likelihood of increased storm intensity added to increasing rates of sea-level rise make predicting the reach of future storm surges essential for planning and adaptation purposes. The National Park Service plays a leading role in developing innovative strategies for coastal parks to adapt to sea-level rise and storm surge, whilst coastal storms are opportunities to apply highly focused responses.

  6. Observing storm surges in the Bay of Bengal from satellite altimetry

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, C.; Testut, L.; Unnikrishnan, A.S.

    with the large tidal ranges give rise to extreme sea level in the head bay and surrounding regions. Moreover, low-lying nature of the coast and the dense population in the region make the coasts of the northern Bay of Bengal highly vulnerable to storm surges...-gauge data during the passage of the hurricane Igor that crossed Newfoundland in 2010. For this event, St. John’s tide gauge recorded a maximum surge of 94 cm and Jason-2 (the track located 89 km away from the tide-gauge station) showed positive sea-level...

  7. Analytical technical of lightning surges induced on grounding mesh of PWR nuclear power plant

    International Nuclear Information System (INIS)

    Ikeda, I.; Tani, M.; Yonezawa, T.

    1990-01-01

    An analytical lightning surge technique is needed to make a qualitative and predictive evaluation of transient voltages induced on local grounding meshes and instrumentation cables by a lightning strike on a lightning rod in a PWR plant. This paper discusses an experiment with lightning surge impulses in a PWR plant which was setup to observe lightning caused transient voltages. Experimental data when compared with EMTP simulation results improved the simulation method. The improved method provides a good estimation of induced voltages on grounding meshes and instrumentation cables

  8. A new concept for glacial geological investigations of surges, based on High-Arctic examples (Svalbard)

    Science.gov (United States)

    Lønne, Ida

    2016-01-01

    Svalbard is a key area for the investigation of glacial surges, and almost two centuries worth of field observations exists from this region. Studies have shown that the course of a surge and the associated formation of landforms are strongly influenced by basinal factors, and that the broad range of variables involved can hamper interpretations and comparisons. Based on a review of surges in Svalbard, a new concept for glacial geological investigations has been developed that combines ice-flows, ice-front movements, and morphostratigraphy. The concept is comprised of the following four elements: 1) classification based on the configuration and characteristics of the receiving basin, 2) division of the surge cycle into six stages, 3) guidelines for morphological mapping, and 4) use of an allostratigraphic approach for interpreting ice-front movements. In this context, delineation of the active phase is critical, which include the history of terminus movements, and four main categories of receiving basins are recognized. These are (A) terrestrial basins with deformable substrates, (B) terrestrial basins with poorly deformable substrates, (C) shallow water basins, and (D) deep water basins. The ice-front movement history is reconstructed by coupling information from the proglacial moraines (syn-surge), the supraglacial moraines (post-surge), and the associated traces of meltwater to the surge stages (I-VI). This approach has revealed a critical relationship between the termination of the active phase and three morphological elements, namely, the maximum ice-front position, the maximum moraine extent and the youngest proglacial moraine, which are unique for each of the basins A-D. The concept is thus a novel and more precise approach for mapping the active phase and the active phase duration, as shown by the ∼12-year long surge of Fridtjovbreen, where stage I was 30 months (inception), stage II was 54 months (ice-front advance), stage III was 12 months (stillstand

  9. Operation of Two-Shaft Gas Turbine in the Range of Open Anti-Surge Valve

    Directory of Open Access Journals (Sweden)

    Dzida Marek

    2017-12-01

    Full Text Available This paper presents experimental tests of full-scale two-shaft gas turbine in the range of open anti-surge valve (ASV. The tests were carried out in a laboratory gas- turbine test stand belonging to Department of Automation and Power Engineering , Faculty of Ocean Engineering and Ship Technology , Gdańsk University of Technology. The tests covered the start-up and low load operation of the turbine set in the range of open anti-surge valve.

  10. Overview of Rotating Cavitation and Cavitation Surge in the Fastrac Engine LOX Turbopump

    Science.gov (United States)

    Zoladz, Thomas; Turner, Jim (Technical Monitor)

    2001-01-01

    Observations regarding rotating cavitation and cavitation surge experienced during the development of the Fastrac 60 Klbf engine turbopump are discussed. Detailed observations from the analysis of both water flow and liquid oxygen test data are offered. Scaling and general comparison of rotating cavitation between water flow and liquid oxygen testing are discussed. Complex data features linking the localized rotating cavitation mechanism of the inducer to system surge components are described in detail. Finally a description of a simple lumped-parameter hydraulic system model developed to better understand observed data is given.

  11. Assessment of the Great Lakes Marine Renewable Energy Resources: Characterizing Lake Erie Surge, Seiche and Waves

    Science.gov (United States)

    Farhadzadeh, A.; Hashemi, M. R.

    2016-02-01

    Lake Erie, the fourth largest in surface area, smallest in volume and shallowest among the Great Lakes is approximately 400 km long and 90 km wide. Short term lake level variations are due to storm surge generated by high winds and moving pressure systems over the lake mainly in the southwest-northeast direction, along the lakes longitudinal axis. The historical wave data from three active offshore buoys shows that significant wave height can exceed 5 m in the eastern and central basins. The long-term lake level data show that storm surge can reach up to 3 m in eastern Lake Erie. Owing its shallow depth, Lake Erie frequently experiences seiching motions, the low frequency oscillations that are initiated by storm surge. The seiches whose first mode of oscillations has a period of nearly 14.2 hours can last from several hours to days. In this study, the Lake Erie potential for power generation, primarily using storm surge and seiche and also waves are assessed. Given the cyclic lake level variations due to storm-induced seiching, a concept similar to that of tidal range development is utilized to assess the potential of storm surge and seiche energy harvesting mechanisms for power generation. In addition, wave energy resources of the Lake is characterized -. To achieve these objectives, the following steps are taken : (1) Frequency of occurrence for extreme storm surge and wave events is determined using extreme value analysis such as Peak-Over-Threshold method for the long-term water level and wave data; (2) Spatial and temporal variations of wave height, storm surge and seiche are characterized. The characterization is carried out using the wave and storm surge outputs from numerical simulation of a number of historical extreme events. The coupled ADCIRC and SWAN model is utilized for the modeling; (3) Assessment of the potentials for marine renewable power generation in Lake Erie is made. The approach can be extended to the other lakes in the Great Lakes region.

  12. Impacts of Storm Surge Mitigation Strategies on Aboveground Storage Tank Chemical Spill Transport

    Science.gov (United States)

    Do, C.; Bass, B. J.; Bernier, C.; Samii, A.; Dawson, C.; Bedient, P. B.

    2017-12-01

    The Houston Ship Channel (HSC), located in the hurricane-prone Houston-Galveston region of the upper Texas Coast, is one of the busiest waterways in the United States and is home to one of the largest petrochemical complexes in the world. Due to the proximity of the HSC to Galveston Bay and the Gulf of Mexico, chemical spills resulting from storm surge damage to aboveground storage tanks (ASTs) pose serious threats to the environment, residential communities, and national/international markets whose activities in the HSC generate billions of dollars annually. In an effort to develop a comprehensive storm surge mitigation strategy for Galveston Bay and its constituents, Rice University's Severe Storm Prediction, Education, and Evacuation from Disasters Center proposed two structural storm surge mitigation concepts, the Mid Bay Structure (MBS) and the Lower Bay Structure (LBS) as components of the Houston-Galveston Area Protection System (H-GAPS) project. The MBS consists of levees along the HSC and a navigational gate across the channel, and the LBS consists of a navigation gate and environmental gates across Bolivar Road. The impacts of these two barrier systems on the fate of AST chemical spills in the HSC have previously been unknown. This study applies the coupled 2D SWAN+ADCIRC model to simulate hurricane storm surge circulation within the Gulf of Mexico and Galveston Bay due to a synthetic storm which results in approximately 250-year surge levels in Galveston Bay. The SWAN+ADCIRC model is run using high-resolution computational meshes that incorporate the MBS and LBS scenarios, separately. The resulting wind and water velocities are then fed into a Lagrangian particle transport model to simulate the spill trajectories of the ASTs most likely to fail during the 250-year proxy storm. Results from this study illustrate how each storm surge mitigation strategy impacts the transport of chemical spills (modeled as Lagrangian particles) during storm surge as

  13. Thermal test of the insulation structure for LH 2 tank by using the large experimental apparatus

    Science.gov (United States)

    Kamiya, S.; Onishi, K.; Konshima, N.; Nishigaki, K.

    Conceptual designs of large mass LH 2 (liquid hydrogen) storage systems, whose capacity is 50,000 m3, have been studied in the Japanese hydrogen project, World Energy Network (WE-NET) [K. Fukuda, in: WE-NET Hydrogen Energy Symposium, 1999, P1-P41]. This study has concluded that their thermal insulation structures for the huge LH 2 tanks should be developed. Their actual insulation structures comprise not only the insulation material but also reinforced members and joints. To evaluate their thermal performance correctly, a large test specimen including reinforced members and joints will be necessary. After verifying the thermal performance of a developed large experimental apparatus [S. Kamiya, Cryogenics 40 (1) (2000) 35] for measuring the thermal conductance of various insulation structures, we tested two specimens, a vacuum multilayer insulation (MLI) with a glass fiber reinforced plastic (GFRP) support and a vacuum solid insulation (microtherm ®) with joints. The thermal background test for verifying the thermal design of the experimental apparatus showed that the background heat leak is 0.1 W, small enough to satisfy apparatus performance requirement. The thermal conductance measurements of specimens also showed that thermal heat fluxes of MLI with a GFRP support and microtherm ® are 8 and 5.4 W/m2, respectively.

  14. Protein dynamics revealed in the excitonic spectra of single LH2 complexes

    International Nuclear Information System (INIS)

    Valkunas, Leonas; Janusonis, Julius; Rutkauskas, Danielis; Grondelle, Rienk van

    2007-01-01

    The fluorescence emission spectrum of single peripheral light-harvesting (LH2) complexes of the photosynthetic purple bacterium Rhodopseudomonas acidophila exhibits remarkable dynamics on a time scale of several minutes. Often the spectral properties are quasi-stable; sometimes large spectral jumps to the blue or to the red are observed. To explain the dynamics, every pigment is proposed to be in two conformational substates with different excitation energies, which originate from the conformational state of the protein as a result of pigment-protein interaction. Due to the excitonic coupling in the ring of 18 pigments, the two-state assumption generates a substantial amount of distinct spectroscopic states, which reflect part of the inhomogeneous distributed spectral properties of LH2. To describe the observed dynamics, spontaneous and light-induced transitions are introduced between the two states. For each 'realization of the disorder', the spectral properties are calculated using a disordered exciton model combined with the modified Redfield theory to obtain realistic spectral line shapes. The single-molecule fluorescence peak (FLP) distribution, the distribution dependence on the excitation intensity, and the FLP time traces are well described within the framework of this model

  15. Orbiter LH2 Feedline Flowliner Cracking Problem. Version 1.0

    Science.gov (United States)

    Harris, Charles E.; Cragg, Clinton H.; Raju, Ivatury S.; Elliot, Kenny B.; Madaras, Eric I.; Piascik, Robert S.; Halford, Gary R.; Bonacuse, Peter J.; Sutliff, Daniel L.; Bakhle, Milind A.

    2005-01-01

    In May of 2002, three cracks were found in the downstream flowliner at the gimbal joint in the LH2 feedline at the interface with the Low Pressure Fuel Turbopump (LPFP) of Space Shuttle Main Engine (SSME) #1 of Orbiter OV-104. Subsequent inspections of the feedline flowliners in the other orbiters revealed the existence of 8 additional cracks. No cracks were found in the LO2 feedline flowliners. A solution to the cracking problem was developed and implemented on all orbiters. The solution included weld repair of all detectable cracks and the polishing of all slot edges to remove manufacturing discrepancies that could initiate new cracks. Using the results of a fracture mechanics analysis with a scatter factor of 4 on the predicted fatigue life, the orbiters were cleared for return to flight with a one-flight rationale requiring inspections after each flight. OV-104 flew mission STS-112 and OV-105 flew mission STS-113. The post-flight inspections did not find any cracks in the repaired flowliners. At the request of the Orbiter Program, the NESC conducted an assessment of the Orbiter LH2 Feedline Flowliner cracking problem with a team of subject matter experts from throughout NASA.

  16. Synchronous Measurement of Ultrafast Anisotropy Decay of the B850 in Bacterial LH2 Complex

    International Nuclear Information System (INIS)

    Wang Yun-Peng; Du Lu-Chao; Zhu Gang-Bei; Wang Zhuan; Weng Yu-Xiang

    2015-01-01

    Ultrafast anisotropic decay is a prominent parameter revealing ultrafast energy and electron transfer; however, it is difficult to be determined reliably owing to the requirement of a simultaneous availability of the parallel and perpendicular polarized decay kinetics. Nowadays, any measurement of anisotropic decay is a kind of approach to the exact simultaneity. Here we report a novel method for a synchronous ultrafast anisotropy decay measurement, which can well determine the anisotropy, even at a very early time, as the rising phase of the excitation laser pulse. The anisotropic decay of the B850 in bacterial light harvesting antenna complex LH2 of Rhodobacter sphaeroides in solution at room temperature with coherent excitation is detected by this method, which shows a polarization response time of 30 fs, and the energy transfer from the initial excitation to the bacteriochlorophylls in B850 ring takes about 70 fs. The anisotropic decay that is probed at the red side of the absorption spectrum, such as 880 nm, has an initial value of 0.4, corresponding to simulated emission, while the blue side with an anisotropy of 0.1 contributes to the ground-state bleaching. Our results show that the coherent excitation covering the whole ring might not be realized owing to the symmetry breaking of LH2: from C_9 symmetry in membrane to C_2 symmetry in solution. (atomic and molecular physics)

  17. LH2 Target Design & Position Survey Techniques for the MUSE experiment for Precise Proton Radius Measurement

    Science.gov (United States)

    Le Pottier, Luc; Roy, Pryiashee; Lorenzon, Wolfgang; Raymond, Richard; Steinberg, Noah; Rossi de La Fuente, Erick; MUSE (MUon proton Scattering Experiment) Collaboration

    2017-09-01

    The proton radius puzzle is a currently unresolved problem which has intrigued the scientific community, dealing with a 7 σ discrepancy between the proton radii determined from muonic hydrogen spectroscopy and electron scattering measurements. The MUon Scattering Experiment (MUSE) aims to resolve this puzzle by performing the first simultaneous elastic scattering measurements of both electrons and muons on the proton, which will allow the comparison of the radii from the two interactions with reduced systematic uncertainties. The data from this experiment is expected to provide the best test of lepton universality to date. The experiment will take place at the Paul Scherrer Institute in Switzerland in 2018. An essential component of the experiment is a liquid hydrogen (LH2) cryotarget system. Our group at the University of Michigan is responsible for the design, fabrication and installation of this system. Here we present our LH2 target cell design and fabrication techniques for successful operation at 20 K and 1 atm, and our computer vision-based target position survey system which will determine the position of the target, installed inside a vacuum chamber, with 0.01 mm or better precision at the height of the liquid hydrogen target and along the beam direction during the experiment.

  18. Development and validation of cryogenic foam insulation for LH2 subsonic transports

    Science.gov (United States)

    Anthony, F. M.; Colt, J. Z.; Helenbrook, R. G.

    1981-01-01

    Fourteen foam insulation specimens were tested. Some were plain foam while others contained flame retardants, chopped fiberglass reinforcement and/or vapor barriers. The thermal performance of the insulation was determined by measuring the rate at which LH2 boiled from an aluminum tank insulated with the test material. The test specimens were approximately 50 mm (2 in.) thick. They were structurally scaled so that the test cycle would duplicate the maximum thermal stresses predicted for the thicker insulation of an aircraft liquid hydrogen fuel tank during a typical subsonic flight. The simulated flight cycle of approximately 10 minutes duration heated the other insulation surface to 316 K (110 F) and cooled it to 226 K (20 F) while the inner insulation surface remained at liquid hydrogen temperature of 20 K (-423 F). Two urethane foam insulations exceeded the initial life goal of 2400 simulated flight cycles and sustained 4400 cycles with only minor damage. The addition of fiberglass reinforcement of flame retardant materials to an insulation degraded thermal performance and/or the life of the foam material. Installation of vapor barriers enhanced the structural integrity of the material but did not improve thermal performance. All of the foams tested were available materials; none were developed specifically for LH2 service.

  19. Quantum coherence spectroscopy reveals complex dynamics in bacterial light-harvesting complex 2 (LH2).

    Science.gov (United States)

    Harel, Elad; Engel, Gregory S

    2012-01-17

    Light-harvesting antenna complexes transfer energy from sunlight to photosynthetic reaction centers where charge separation drives cellular metabolism. The process through which pigments transfer excitation energy involves a complex choreography of coherent and incoherent processes mediated by the surrounding protein and solvent environment. The recent discovery of coherent dynamics in photosynthetic light-harvesting antennae has motivated many theoretical models exploring effects of interference in energy transfer phenomena. In this work, we provide experimental evidence of long-lived quantum coherence between the spectrally separated B800 and B850 rings of the light-harvesting complex 2 (LH2) of purple bacteria. Spectrally resolved maps of the detuning, dephasing, and the amplitude of electronic coupling between excitons reveal that different relaxation pathways act in concert for optimal transfer efficiency. Furthermore, maps of the phase of the signal suggest that quantum mechanical interference between different energy transfer pathways may be important even at ambient temperature. Such interference at a product state has already been shown to enhance the quantum efficiency of transfer in theoretical models of closed loop systems such as LH2.

  20. Synchronous Measurement of Ultrafast Anisotropy Decay of the B850 in Bacterial LH2 Complex

    Science.gov (United States)

    Wang, Yun-Peng; Du, Lu-Chao; Zhu, Gang-Bei; Wang, Zhuan; Weng, Yu-Xiang

    2015-02-01

    Ultrafast anisotropic decay is a prominent parameter revealing ultrafast energy and electron transfer; however, it is difficult to be determined reliably owing to the requirement of a simultaneous availability of the parallel and perpendicular polarized decay kinetics. Nowadays, any measurement of anisotropic decay is a kind of approach to the exact simultaneity. Here we report a novel method for a synchronous ultrafast anisotropy decay measurement, which can well determine the anisotropy, even at a very early time, as the rising phase of the excitation laser pulse. The anisotropic decay of the B850 in bacterial light harvesting antenna complex LH2 of Rhodobacter sphaeroides in solution at room temperature with coherent excitation is detected by this method, which shows a polarization response time of 30 fs, and the energy transfer from the initial excitation to the bacteriochlorophylls in B850 ring takes about 70 fs. The anisotropic decay that is probed at the red side of the absorption spectrum, such as 880 nm, has an initial value of 0.4, corresponding to simulated emission, while the blue side with an anisotropy of 0.1 contributes to the ground-state bleaching. Our results show that the coherent excitation covering the whole ring might not be realized owing to the symmetry breaking of LH2: from C9 symmetry in membrane to C2 symmetry in solution.