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Sample records for pre-ovulatory lh surge

  1. Role of hypothalamus nociceptin/orphanin FQ in pre-ovulatory luteinizing hormone surge of estrogen and progesterone-primed, ovariectomized rats

    Institute of Scientific and Technical Information of China (English)

    Xiao-fei AN; Jiang-yi YU; Yi FENG; Bo-ying CHEN; Su-lin ZHANG

    2007-01-01

    Aim: To investigate the role of hypothalamus nociceptin/orphanin FQ (OFQ) and its endogenous receptor, the opioid receptor-likel receptor (ORL1 receptor) in the estrus cycle of female rats. Method: Radioimmunoassay was used to detect the effect of the intracerebroventricular (icv) administration of OFQ and/or the ORL1 receptor antagonist [Nphel]Nociceptin(1-13)NH2 that is, NC13 on luteinizing hormone (LH) levels of estrogen- and progesterone (EBP)-primed, ovariectomized (OVX) rats (EBP-primed OVX rats). RT-PCR, Western blotting, and immunohis- tochemistry techniques were adopted to observe the changes of OFQ and the ORL1 receptor in the pre-optic area (POA) and the medial basal hypothalamus (MBH) of the estrus cycle of female rat. Results: Pre-ovulatory LH surges in EBP-primed, OVX rats were significantly reduced by icv administration of 20 and 200 nmol OFQ (P<0.05), and the effect of 20 nmol OFQ could be abolished by pretreat-ment with 20 nmol NC13. The OFQ mRNA level in the POA on pro-estrus was lowered markedly compared to diestrus and estrus (P<0.05), while the mRNA and protein levels of the ORL1 receptor showed no significant changes in the POA and MBH across the estrus cycle. Meanwhile, the number of OFQ-immunoreac-tive neurons in the medial POA, ventromedial hypothalamus, and the arcuate nucleus on pro-estrus was significantly decreased compared to diestrus and es-trus (P<0.05). Conclusion: The inhibitory effect of OFQ on the LH surge of EBP-primed, OVX rats and its downregulation in POA and MBH on pro-estrus sug-gests that it might play a negative modulatory role in the estrus cycle.

  2. The "Ram Effect": A "Non-Classical" Mechanism for Inducing LH Surges in Sheep.

    Science.gov (United States)

    Fabre-Nys, Claude; Chanvallon, Audrey; Dupont, Joëlle; Lardic, Lionel; Lomet, Didier; Martinet, Stéphanie; Scaramuzzi, Rex J

    2016-01-01

    During spring sheep do not normally ovulate but exposure to a ram can induce ovulation. In some ewes an LH surge is induced immediately after exposure to a ram thus raising questions about the control of this precocious LH surge. Our first aim was to determine the plasma concentrations of oestradiol (E2) E2 in anoestrous ewes before and after the "ram effect" in ewes that had a "precocious" LH surge (starting within 6 hours), a "normal" surge (between 6 and 28h) and "late» surge (not detected by 56h). In another experiment we tested if a small increase in circulating E2 could induce an LH surge in anoestrus ewes. The concentration of E2 significantly was not different at the time of ram introduction among ewes with the three types of LH surge. "Precocious" LH surges were not preceded by a large increase in E2 unlike "normal" surges and small elevations of circulating E2 alone were unable to induce LH surges. These results show that the "precocious" LH surge was not the result of E2 positive feedback. Our second aim was to test if noradrenaline (NA) is involved in the LH response to the "ram effect". Using double labelling for Fos and tyrosine hydroxylase (TH) we showed that exposure of anoestrous ewes to a ram induced a higher density of cells positive for both in the A1 nucleus and the Locus Coeruleus complex compared to unstimulated controls. Finally, the administration by retrodialysis into the preoptic area, of NA increased the proportion of ewes with an LH response to ram odor whereas treatment with the α1 antagonist Prazosin decreased the LH pulse frequency and amplitude induced by a sexually active ram. Collectively these results suggest that in anoestrous ewes NA is involved in ram-induced LH secretion as observed in other induced ovulators.

  3. Effects of superovulation with oFSH and norgestomet/GnRH-controlled release of the LH surge on hormone concentrations, and yield of oocytes and embryos at specific developmental stages.

    Science.gov (United States)

    Knijn, H M; Fokker, W; van der Weijden, G C; Dieleman, S J; Vos, P L A M

    2012-04-01

    The objective of this study was to evaluate a new superovulation procedure with oFSH after temporary suppression of the endogenous LH surge by norgestomet followed by administration of GnRH, to collect bovine oocytes and embryos at specific developmental stages. Since 1999, our research group applies this superovulation procedure with controlled release of the endogenous LH surge. The objective of this study is to verify if this procedure is reliable for collection of oocytes and embryos at specific time points of development and if it produces a sufficient number of both oocytes and embryos of good quality. This procedure was validated regarding to hormonal characteristics, superovulatory response and both oocyte and embryo yield at different times of in vivo development. The results demonstrate that the procedure used to control the occurrence of the pre-ovulatory LH surge was effective in 92% of the animals (n = 238) and even in 99% of the animals the oocytes and embryos were collected at the intended stage of development. The superovulatory response and both oocyte, embryo yield and quality were similar to the average yield in Europe reported by Association Européenne de transfert embryonnaire (AETE). In conclusion, this superovulation procedure provides a valid tool to collect oocytes and embryos at specific time points of development. © 2008 Blackwell Verlag GmbH.

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

    Science.gov (United States)

    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. Effect of monensin on the estrogen-induced LH surge in prepuberal heifers.

    Science.gov (United States)

    Randel, R D; Rutter, L M; Rhodes, R D

    1982-04-01

    The effect of dietary monensin on the luteinizing hormone (LH) surge following estradiol-17 beta (E2) injection was investigated in prepuberal Simmental X Brahman-Hereford heifers. Ten heifers, weighing approximately 260 kg and approximately 10 mo of age, were equally divided by age and weight into two groups: control (C) heifers each received 1.8 kg/d of a concentrate diet plus Coastal bermudagrass hay ad libitum; monensin (M) heifers each received the same diet plus 200 mg monensin/d. All heifers were maintained in dry lots on their respective diets for 14 d before the E2 challenge. On d 15, all heifers were injected in with 5 mg of E2 in corn oil. Blood samples were collected via tail vessel puncture immediately before E2 injection and at 2-h intervals until 48 h after the E2 injection. The samples were processed for serum and stored at -20 degrees C until LH concentrations were measured by radioimmunoassay. Mean concentrations of LH in serum differed (P less than .005) between C and M heifers and with time after E2 injection. A treatment X sampling period interaction (P less than .10) indicated that maximum serum concentrations of LH (LH surge) were detected earlier (P less than .001) for M (17.2 +/- 1.8 h) than C (27.0 +/- 6.0 h) heifers after the E2 injection. When the data were arrayed relative to the time of the LH surge, treatment (P less than .05) and sampling period (P less than .001) effects were significant, but a treatment X sampling period interaction was not detected. Peak LH concentration was 23.1 +/- 3.0 ng/ml for M heifers and 21.6+/- 4.2 ng/ml for controls (P greater than .10). Duration of the LH surge was 8.0 +/- .9 h in M heifers and 4.8 +/- 1.6 h in C heifers (P less than .001). Area under the LH surge was greater (P less than .001) in M heifers than in control heifers. We conclude that dietary monensin altered the estrogen-induced LH surge in prepuberal heifers.

  6. DIBROMOACETIC ACID ATTENUATES A DIMETHYLDITHIOCARBAMATE-INDUCED SUPPRESSION OF THE RAT LH SURGE

    Science.gov (United States)

    DIBROMOACETIC ACID ATTENUATES A DITHIOCARBAMATE-INDUCED SUPPRESSION OF THE LH SURGE IN THE RAT. Jerome M. Goldman, Ashley S. Murr, Angela R. Buckelew, W. Keith McElroy and Janet M. Ferrell. Repro. Toxicol. Div., NHEERL, ORD, US EPA, RTP, NCAt elevated concentrations, the ...

  7. Homocysteine metabolism in the pre-ovulatory follicle during ovarian stimulation

    NARCIS (Netherlands)

    Boxmeer, Jolanda C.; Steegers-Theunissen, Regine P. M.; Lindemans, Jan; Wildhagen, Mark F.; Martini, Elena; Steegers, Eric A. P.; Macklon, Nick S.

    2008-01-01

    BACKGROUND: Ovarian stimulation gives rise to supraphysiological estradiol levels, which may affect oocyte quality. This study aims to investigate whether ovarian stimulation deranges the homocysteine pathway thereby affecting the pre-ovulatory follicle. METHODS: Blood samples were collected on

  8. Homocysteine metabolism in the pre-ovulatory follicle during ovarian stimulation

    NARCIS (Netherlands)

    Boxmeer, Jolanda C.; Steegers-Theunissen, Regine P. M.; Lindemans, Jan; Wildhagen, Mark F.; Martini, Elena; Steegers, Eric A. P.; Macklon, Nick S.

    2008-01-01

    BACKGROUND: Ovarian stimulation gives rise to supraphysiological estradiol levels, which may affect oocyte quality. This study aims to investigate whether ovarian stimulation deranges the homocysteine pathway thereby affecting the pre-ovulatory follicle. METHODS: Blood samples were collected on cycl

  9. Homocysteine metabolism in the pre-ovulatory follicle during ovarian stimulation

    NARCIS (Netherlands)

    J.C. Boxmeer (Jolanda); R.P.M. Steegers-Theunissen (Régine); J. Lindemans (Jan); M.F. Wildhagen (Mark); E. Martini (Elena); E.A.P. Steegers (Eric); N.S. Macklon (Nick)

    2008-01-01

    textabstractBACKGROUND: Ovarian stimulation gives rise to supraphysiological estradiol levels, which may affect oocyte quality. This study aims to investigate whether ovarian stimulation deranges the homocysteine pathway thereby affecting the pre-ovulatory follicle. METHODS: Blood samples were colle

  10. RU486 administration blocks neuropeptide Y potentiation of luteinizing hormone (LH)-releasing hormone-induced LH surges in proestrous rats.

    Science.gov (United States)

    Bauer-Dantoin, A C; Tabesh, B; Norgle, J R; Levine, J E

    1993-12-01

    We previously demonstrated that NPY potentiates LHRH-induced LH secretion specifically under endocrine conditions in which preovulatory LH surges are generated. The present study was designed to test the hypothesis that NPY's facilitatory actions are dependent upon preovulatory progesterone secretion. In Exp 1, female rats were fitted with atrial catheters on diestrus. On proestrus, hourly blood samples were collected from 1100-2100 h. At 1230 h, rats received a sc injection of the progesterone receptor antagonist RU486 (6 mg/kg BW) or oil. At 1330 h, rats received pentobarbital (40 mg/kg BW), to block hypothalamic LHRH release, or saline. Every 30 min from 1400-1800 h, pentobarbital-treated rats received iv pulses of LHRH (15 ng/pulse) or saline along with concurrent pulses of NPY (5 micrograms/pulse), or saline. In Exp 2, rats received jugular catheters on diestrus, but were sampled every hour throughout the morning (0700-1600 h), rather than the afternoon, of proestrus. In these morning groups, pentobarbital was injected at 0830 h, and peptides (LHRH or combined LHRH and NPY solutions) were administered as pulses at 30-min intervals between 0900-1300 h. Results from Exp 1 were as follows: administration of RU486 to rats given an ip injection of vehicle at 1330 h and pulses of saline from 1400-1800 h completely blocked the endogenous LH surge. In oil-treated pentobarbital-blocked rats, concurrent administration of NPY with LHRH significantly (P < 0.01) potentiated the ability of LHRH to restore LH surges. However, NPY was without any potentiating effects in animals pretreated with RU486 at 1230 h. RU486 also attenuated the ability of LHRH alone to restore LH surges in pentobarbital-blocked rats. In Exp 2, NPY was without effect on LHRH-induced LH secretion during the morning hours of proestrus. Our results demonstrate that 1) NPY facilitates LHRH-induced LH surges on the afternoon of proestrus; 2) presumptive progesterone receptor blockade by RU486 completely

  11. Plasma and ovarian oestradiol and the variability in the LH surge induced in ewes by the ram effect.

    Science.gov (United States)

    Fabre-Nys, Claude; Chanvallon, Audrey; Debus, Nathalie; François, Dominique; Bouvier, Frédéric; Dupont, Joelle; Lardic, Lionel; Lomet, Didier; Ramé, Christelle; Scaramuzzi, Rex J

    2015-05-01

    The proportion of anoestrous ewes ovulating after exposure to a sexually active ram is variable mainly due to whether an LH surge is induced. The aim of this study was to determine the role of oestradiol (E2) in the ram-induced LH surge. In one study, we measured the plasma concentrations of E2 in ewes of different breeds before and after the 'ram effect' and related these patterns to the presence and latency of the LH surge, while another compared ovarian responses with the 'ram effect' following exposure to rams for 2 or 12 h. In all ewes, the concentration of E2 increased 2-4 h after rams were introduced and remained elevated for 14.5 ± 0.86 h. The quantity of E2 secreted before the LH surge varied among breeds as did the mean concentration of E2. The granulosa cells of IF ewes collected after 12 h exposure to rams secreted more E2 and progesterone and had higher levels of StAR than the 2 h group but in MV ewes there was no differences between these groups for any of these parameters. These results demonstrate that the LH surge induced by the rams is a result of increased E2 secretion associated with increased levels of STAR in granulosa cells and that these responses varied among breeds. The results suggest that the variable occurrence of a LH surge and ovulation may be the result of variable ovarian responses to the 'ram effect' and insensitivity of the hypothalamus to the E2-positive feedback signal.

  12. Importance of intense male sexual behavior for inducing the preovulatory LH surge and ovulation in seasonally anovulatory female goats.

    Science.gov (United States)

    Martínez-Alfaro, J C; Hernández, H; Flores, J A; Duarte, G; Fitz-Rodríguez, G; Fernández, I G; Bedos, M; Chemineau, P; Keller, M; Delgadillo, J A; Vielma, J

    2014-10-15

    The present study was carried out to determine whether the presence of photostimulated sedated male goats could stimulate the LH preovulatory surge and ovulation in seasonal anestrous goats. Sexually experienced male goats were treated with artificial long days (16 hours light per day) from 1 November to 15 January to stimulate their sexual activity in March and April, corresponding to the natural sexual rest. A female group of goats (n=20) was exposed to non-sedated males who displayed an intense sexual behavior and provided strong odor (non-sedated group). Another female group of goats (n=20) was exposed to the photo-stimulated male goats, but these males were sedated with Xylazine 2% to prevent the expression of sexual behavior (sedated group). The sedated males also provided a strong odor. Females of both groups had full physical and visual contact with non-sedated or sedated males. In both groups, the males remained with females during 4 days. The LH preovulatory surge of 10 female goats per group was measured by determination of LH plasma concentrations in samples taken every 3 hours. In addition, in all goats, (n=20 by group), ovulation was determined by measuring plasma concentrations of progesterone. The proportion of female goats showing a preovulatory LH surge was higher in goats exposed to non-sedated (10/10) than in those exposed to sedated bucks (0/10; Psexual behavior by male goats is necessary to induce LH preovulatory surge and ovulation in seasonally anovulatory goats. Copyright © 2014 Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

    Science.gov (United States)

    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.

  16. RELATIONSHIP BETWEEN OOCYTE MATURITY FOR FERTILIZATION AND PRE-OVULATORY FOLLICULAR FLUID HORMONE LEVELS IN INDUCED OVULATORYCY CLE

    Institute of Scientific and Technical Information of China (English)

    LIUYong

    1989-01-01

    This paper describes the relationship between haman oocyte matarity for fcrtilization andpre-ovulalory follicular fluid hormone levels in induced ova]story cycle by trealmcm withclomiphenz+HMG or clomiphene+HMC+HCG. 32 hours after urine LH--surge or 34

  17. Membrane-initiated actions of estradiol (E2 in the regulation of LH secretion in ovariectomized (OVX ewes

    Directory of Open Access Journals (Sweden)

    Oakley Amy E

    2010-05-01

    administration of E2BSA near the beginning of the pre-ovulatory surge of LH delays and reduces the magnitude of the surge.

  18. Evaluation of a new approach for the estimation of the time of the LH surge in dairy cows using vaginal temperature and electrodeless conductivity measurements.

    Science.gov (United States)

    Fisher, A D; Morton, R; Dempsey, J M A; Henshall, J M; Hill, J R

    2008-10-15

    The objective of the study was to test the effectiveness of a new type of conductivity sensor, along with vaginal temperature, at identifying the LH peak associated with estrus in dairy cows. Twelve mature non-lactating Holstein-Friesian cows had their estrous cycles synchronized on two occasions, and then data were collected for the following spontaneous cycles. An indwelling electrodeless plastic-coated toroidal conductivity sensor, which also recorded temperature, was placed in the vagina throughout the cycle. Blood samples were collected for LH measurement, and ultrasound scanning used to confirm ovulation. Although there was a relationship between vaginal mucus conductivity measured by the toroidal sensor and the timing of the LH surge, it was not sufficiently robust in individual cows to be able to identify the time of the LH surge. The mean increase in vaginal temperature at estrus was 0.48 degrees C. An algorithm was developed which used the detected individual cow temperature peak to test the relationship with the LH peak. In 16 out of 21 cases where ovulation was confirmed and data existed, the estimated individual peak was within 4h of the LH surge, in three cases it was +/-6h, and in two instances it was early. In conclusion, the temperature algorithm was able to identify the time of the LH surge and thus predict time of ovulation in a way that would allow effective AI, although this result needs to be tested in lactating cows. However, the toroidal conductivity sensing method was not able to produce data of sufficient quality to develop a predictive relationship in individual cows.

  19. Specific genes are selectively expressed between cumulus and granulosa cells from individual human pre-ovulatory follicles

    DEFF Research Database (Denmark)

    Grøndahl, M L; Andersen, C Yding; Bogstad, J;

    2012-01-01

    During folliculogenesis the granulosa cells differentiate into two cell types: Cumulus cells (CC) and mural granulosa cells (MGC). The objective of the study was to generate and compare the transcriptomes of MGC and CC from the pre-ovulatory follicle to characterize the detailed profile of the two...

  20. Atrazine-induced elevation or attenuation of the LH surge in the ovariectomized, estrogen-primed female rat: role of adrenal progesterone

    Science.gov (United States)

    Multiple daily exposures to the herbicide atrazine have been reported to suppress the surge of luteinizing hormone (LH) in both cycling female rats and those that are ovariectomized (OVX) and exogenously primed with steroids. Additional studies have also found elevations in both ...

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

    Science.gov (United States)

    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

    Science.gov (United States)

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

    Science.gov (United States)

    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...

  4. Atrazine-induced elevation or attenuation of the LH surge in the ovariectomized, estrogen-primed female rat: role of adrenal progesterone

    Science.gov (United States)

    Multiple daily exposures to the herbicide atrazine have been reported to suppress the surge of luteinizing hormone (LH) in both cycling female rats and those that are ovariectomized (OVX) and exogenously primed with steroids. Additional studies have also found elevations in both ...

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

    Science.gov (United States)

    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...

  6. 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...

  7. The Increase in Signaling by Kisspeptin Neurons in the Preoptic Area and Associated Changes in Clock Gene Expression That Trigger the LH Surge in Female Rats Are Dependent on the Facilitatory Action of a Noradrenaline Input.

    Science.gov (United States)

    Kalil, Bruna; Ribeiro, Aline B; Leite, Cristiane M; Uchôa, Ernane T; Carolino, Ruither O; Cardoso, Thais S R; Elias, Lucila L K; Rodrigues, José A; Plant, Tony M; Poletini, Maristela O; Anselmo-Franci, Janete A

    2016-01-01

    In rodents, kisspeptin neurons in the rostral periventricular area of the third ventricle (RP3V) of the preoptic area are considered to provide a major stimulatory input to the GnRH neuronal network that is responsible for triggering the preovulatory LH surge. Noradrenaline (NA) is one of the main modulators of GnRH release, and NA fibers are found in close apposition to kisspeptin neurons in the RP3V. Our objective was to interrogate the role of NA signaling in the kisspeptin control of GnRH secretion during the estradiol induced LH surge in ovariectomized rats, using prazosin, an α1-adrenergic receptor antagonist. In control rats, the estradiol-induced LH surge at 17 hours was associated with a significant increase in GnRH and kisspeptin content in the median eminence with the increase in kisspeptin preceding that of GnRH and LH. Prazosin, administered 5 and 3 hours prior to the predicted time of the LH surge truncated the LH surge and abolished the rise in GnRH and kisspeptin in the median eminence. In the preoptic area, prazosin blocked the increases in Kiss1 gene expression and kisspeptin content in association with a disruption in the expression of the clock genes, Per1 and Bmal1. Together these findings demonstrate for the first time that NA modulates kisspeptin synthesis in the RP3V through the activation of α1-adrenergic receptors prior to the initiation of the LH surge and indicate a potential role of α1-adrenergic signaling in the circadian-controlled pathway timing of the preovulatory LH surge.

  8. Biochemical composition of the fluid of ovarian cysts and pre-ovulatory follicles compared to the serum in sows.

    Science.gov (United States)

    Stankiewicz, T

    2015-01-01

    The objective of this study was to compare the biochemical composition of follicular cysts, pre-ovulatory follicles and serum in sows. The research involved multiparous sows (cysts-bearing sows, n = 21; non-cysts-bearing sows, n = 22). Concentration of glucose, protein, cholesterol (CHOL), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triacylglycerol (TAG) in the samples was determined. Glucose concentration in serum was higher than in cysts and follicles (p sows (p sows and non-cysts-bearing sows was higher than the one in cysts and follicles (p sows was higher than the one in non-cysts-bearing sows (p sows was also higher than the one in cysts and follicles (p sows had a higher concentration of HDL in the serum than non-cysts-bearing sows. Differences were also observed between the concentration of HDL in cysts and the one in follicles (p sows was higher than the one in the serum of non-cysts-bearing sows (p < 0.05). Differences were also detected between the TAG concentrations in cysts and in follicles (p < 0.01). The differences in the biochemical composition of the fluid in follicular cysts and pre-ovulatory follicles point to the variable intensification of the course of metabolic processes in pathological and physiological ovarian structures.

  9. The effects of knife cuts in the sub-paraventricular zone of the female rat hypothalamus on oestrogen-induced diurnal surges of plasma prolactin and LH, and circadian wheel-running activity.

    Science.gov (United States)

    Watts, A G; Sheward, W J; Whale, D; Fink, G

    1989-08-01

    To investigate the role of suprachiasmatic efferent connections in the expression of diurnal hormone rhythms, the efferent pathway from the suprachiasmatic nucleus (the putative circadian generator in the rat) to the subparaventricular zone (the main terminal area of suprachiasmatic efferents) was disrupted using bilateral horizontal knife cuts in ovariectomized oestrogen-treated rats. The position of the knife cut was assessed by observing its effect on vasoactive intestinal polypeptide immunoreactivity (a marker for suprachiasmatic efferents into the sub-paraventricular zone). The size of both the diurnal plasma LH and prolactin surges was markedly and consistently reduced over the 3-week period following the lesion in animals with a total deafferentation of the subparaventricular zone, compared with sham-operated animals or lesioned animals with an intact subparaventricular zone. When lesioned animals were grouped according to the presence or absence of damage to the preoptic area, no significant differences were found in the sizes of the plasma hormone surges. When similar knife cuts were given to animals whose activity cycles were observed, no significant effects were noted in the ability of the animals to synchronize to a light/dark regime or to free-run in constant light conditions. These results suggest that the suprachiasmatic nucleus influences the diurnal surges of plasma LH and prolactin in oestrogen-treated ovariectomized rats, initially by an interaction with the subparaventricular zone and not by a direct influence on gonadotrophin-releasing hormone neurones or other more rostral structures.

  10. Water temperature and pH influence olfactory sensitivity to pre-ovulatory and post-ovulatory ovarian pheromones in male Barilius bendelisis

    Indian Academy of Sciences (India)

    J P Bhatt; J S Kandwal; R Nautiyal

    2002-06-01

    The attractive response and sexual activity elicited by pre-ovulatory steroid sulphate and post-ovulatory 15K-PGF pheromones are greater in wild caught tubercular males and immature males which express breeding tubercles on the snout (at 12–13 days post androgen implant) than in non-tubercular and non-androgen implanted males of freshwater fish Barilius bendelisis. This shows that circulatory androgens exert an activational effect on olfactory receptors of male fish. Wild caught tubercular males and androgen implanted juvenile males exhibit a high responsiveness to steroid sulphate at the water temperature and pH which fish experience during the pre-spawning phase. The male’s sensitivity to 15K-PGF is almost equally high at the water temperature and pH which they experience in wild during the both pre-spawning and spawning periods. This suggests that the differential olfactory sensitivity to the two classes of pheromones in androgen implanted males is due to the varied temperature and pH of water, and that during the breeding season the male’s olfactory sensitivity to PGF pheromone is more widespread than to the steroidal pheromone. An increased and decreased olfactory sensitivity in mature males to sex pheromones and L-alanine respectively during the breeding phase is in agreement with the hypothesis that pheromonal stimuli dominate over feeding stimuli to promote spawning success.

  11. 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.

  12. Cortisol interferes with the estradiol-induced surge of luteinizing hormone in the ewe.

    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

    2009-03-01

    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 approximately 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.

  13. 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

    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...... (AVP), but not vasoactive intestinal polypeptide-ergic, projections. Because AVP administration can only stimulate the LH surge during a restricted time of day, we examined the possibility that the response to AVP is gated at the level of kisspeptin and/or GnRH neurons. Kisspeptin and GnRH activation...... were assessed after the administration of AVP during the morning (when AVP is incapable of initiating the LH surge) and the afternoon (when AVP injections stimulate the LH surge). Kisspeptin, but not GnRH, cellular activity was up-regulated after morning injections of AVP, suggesting that time...

  14. 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

  15. KNDy Neurons Modulate the Magnitude of the Steroid-Induced Luteinizing Hormone Surges in Ovariectomized Rats.

    Science.gov (United States)

    Helena, Cleyde V; Toporikova, Natalia; Kalil, Bruna; Stathopoulos, Andrea M; Pogrebna, Veronika V; Carolino, Ruither O; Anselmo-Franci, Janete A; Bertram, Richard

    2015-11-01

    Kisspeptin is the most potent stimulator of LH release. There are two kisspeptin neuronal populations in the rodent brain: in the anteroventral periventricular nucleus (AVPV) and in the arcuate nucleus. The arcuate neurons coexpress kisspeptin, neurokinin B, and dynorphin and are called KNDy neurons. Because estradiol increases kisspeptin expression in the AVPV whereas it inhibits KNDy neurons, AVPV and KNDy neurons have been postulated to mediate the positive and negative feedback effects of estradiol on LH secretion, respectively. Yet the role of KNDy neurons during the positive feedback is not clear. In this study, ovariectomized rats were microinjected bilaterally into the arcuate nucleus with a saporin-conjugated neurokinin B receptor agonist for targeted ablation of approximately 70% of KNDy neurons. In oil-treated animals, ablation of KNDy neurons impaired the rise in LH after ovariectomy and kisspeptin content in both populations. In estradiol-treated animals, KNDy ablation did not influence the negative feedback of steroids during the morning. Surprisingly, KNDy ablation increased the steroid-induced LH surges, accompanied by an increase of kisspeptin content in the AVPV. This increase seems to be due to lack of dynorphin input from KNDy neurons to the AVPV as the following: 1) microinjections of a dynorphin antagonist into the AVPV significantly increased the LH surge in estradiol-treated rats, similar to KNDy ablation, and 2) intra-AVPV microinjections of dynorphin in KNDy-ablated rats restored LH surge levels. Our results suggest that KNDy neurons provide inhibition to AVPV kisspeptin neurons through dynorphin and thus regulate the amplitude of the steroid-induced LH surges.

  16. Release of norepinephrine in the preoptic area activates anteroventral periventricular nucleus neurons and stimulates the surge of luteinizing hormone.

    Science.gov (United States)

    Szawka, Raphael E; Poletini, Maristela O; Leite, Cristiane M; Bernuci, Marcelo P; Kalil, Bruna; Mendonça, Leonardo B D; Carolino, Ruither O G; Helena, Cleyde V V; Bertram, Richard; Franci, Celso R; Anselmo-Franci, Janete A

    2013-01-01

    The role of norepinephrine (NE) in regulation of LH is still controversial. We investigated the role played by NE in the positive feedback of estradiol and progesterone. Ovarian-steroid control over NE release in the preoptic area (POA) was determined using microdialysis. Compared with ovariectomized (OVX) rats, estradiol-treated OVX (OVX+E) rats displayed lower release of NE in the morning but increased release coincident with the afternoon surge of LH. OVX rats treated with estradiol and progesterone (OVX+EP) exhibited markedly greater NE release than OVX+E rats, and amplification of the LH surge. The effect of NE on LH secretion was confirmed using reverse microdialysis. The LH surge and c-Fos expression in anteroventral periventricular nucleus neurons were significantly increased in OVX+E rats dialyzed with 100 nm NE in the POA. After Fluoro-Gold injection in the POA, c-Fos expression in Fluoro-Gold/tyrosine hydroxylase-immunoreactive neurons increased during the afternoon in the A2 of both OVX+E and OVX+EP rats, in the locus coeruleus (LC) of OVX+EP rats, but was unchanged in the A1. The selective lesion of LC terminals, by intracerebroventricular N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine, reduced the surge of LH in OVX+EP but not in OVX+E rats. Thus, estradiol and progesterone activate A2 and LC neurons, respectively, and this is associated with the increased release of NE in the POA and the magnitude of the LH surge. NE stimulates LH secretion, at least in part, through activation of anteroventral periventricular neurons. These findings contribute to elucidation of the role played by NE during the positive feedback of ovarian steroids.

  17. Deep FIFO Surge Buffer

    Science.gov (United States)

    Temple, Gerald; Siegel, Marc; Amitai, Zwie

    1991-01-01

    First-in/first-out (FIFO) temporarily stores short surges of data generated by data-acquisition system at excessively high rate and releases data at lower rate suitable for processing by computer. Size and complexity reduced while capacity enhanced by use of newly developed, sophisticated integrated circuits and by "byte-folding" scheme doubling effective depth and data rate.

  18. Deep FIFO Surge Buffer

    Science.gov (United States)

    Temple, Gerald; Siegel, Marc; Amitai, Zwie

    1991-01-01

    First-in/first-out (FIFO) temporarily stores short surges of data generated by data-acquisition system at excessively high rate and releases data at lower rate suitable for processing by computer. Size and complexity reduced while capacity enhanced by use of newly developed, sophisticated integrated circuits and by "byte-folding" scheme doubling effective depth and data rate.

  19. Surge-damping vacuum valve

    Science.gov (United States)

    Bullock, Jack C.; Kelly, Benjamin E.

    1980-01-01

    A valve having a mechanism for damping out flow surges in a vacuum system which utilizes a slotted spring-loaded disk positioned adjacent the valve's vacuum port. Under flow surge conditions, the differential pressure forces the disk into sealing engagement with the vacuum port, thereby restricting the flow path to the slots in the disk damping out the flow surge.

  20. Svalbard surging glacier landsystems

    Science.gov (United States)

    Lovell, Harold; Benn, Douglas; Lukas, Sven; Flink, Anne

    2014-05-01

    The percentage of Svalbard glaciers thought to be of surge-type is somewhere between 13-90% according to different sources variously based on statistical analysis and observations of diagnostic glaciological and geomorphological features, e.g. looped moraines. Developing a better understanding of which of these figures, if either, is most realistic is important in the context of glacier dynamics and related contributions of small glaciers and ice caps to sea level change in the immediate future. We present detailed geomorphological assessments of the margins of several known surge-type glaciers in Svalbard in order to update and improve the existing framework by which they are identified, and to provide a foundation for future reassessments of the surge-type glacier population based on distinct landform-sediment assemblages. Three landsystems are proposed: (1) Surges of small valley glaciers produce a prominent ice-cored latero-frontal moraine at their surge maximum and are characterised by an inner zone of ice stagnation terrain (hummocky topography, kettle lakes, debris flows) with no or only very few poorly-defined bedforms (crevasse squeeze ridges, eskers and flutes) and no recessional moraines. Many of these glaciers may have surged in the past but show no signs that they have the capability to do so again in the future. (2) Larger land-terminating glaciers, often with several tributaries, typically produce a push moraine complex which contains evidence for multiple advances, as identified from ridge-meltwater channel relationships. The inner zone often contains a large lagoon, partly dammed by the push moraine complex, and widespread ice stagnation terrain. Crevasse squeeze ridges, eskers and flutes are well-defined but small and limited in number and distribution. (3) Surges of large tidewater glaciers produce distinctive, often multi-generational, landform assemblages both in submarine and lateral terrestrial positions. The well-preserved submarine record

  1. Demand surge following earthquakes

    Science.gov (United States)

    Olsen, Anna H.

    2012-01-01

    Demand surge is understood to be a socio-economic phenomenon where repair costs for the same damage are higher after large- versus small-scale natural disasters. It has reportedly increased monetary losses by 20 to 50%. In previous work, a model for the increased costs of reconstruction labor and materials was developed for hurricanes in the Southeast United States. The model showed that labor cost increases, rather than the material component, drove the total repair cost increases, and this finding could be extended to earthquakes. A study of past large-scale disasters suggested that there may be additional explanations for demand surge. Two such explanations specific to earthquakes are the exclusion of insurance coverage for earthquake damage and possible concurrent causation of damage from an earthquake followed by fire or tsunami. Additional research into these aspects might provide a better explanation for increased monetary losses after large- vs. small-scale earthquakes.

  2. Heterogeneity in Karakoram glacier surges

    Science.gov (United States)

    Quincey, Duncan J.; Glasser, Neil F.; Cook, Simon J.; Luckman, Adrian

    2015-07-01

    Many Karakoram glaciers periodically undergo surges during which large volumes of ice and debris are rapidly transported downglacier, usually at a rate of 1-2 orders of magnitude greater than during quiescence. Here we identify eight recent surges in the region and map their surface velocities using cross-correlation feature tracking on optical satellite imagery. In total, we present 44 surface velocity data sets, which show that Karakoram surges are generally short-lived, lasting between 3 and 5 years in most cases, and have rapid buildup and relaxation phases, often lasting less than a year. Peak velocities of up to 2 km a-1 are reached during summer months, and the surges tend to diminish during winter months. Otherwise, they do not follow a clearly identifiable pattern. In two of the surges, the peak velocity travels down-ice through time as a wave, which we interpret as a surge front. Three other surges are characterized by high velocities that occur simultaneously across the entire glacier surface, and acceleration and deceleration are close to monotonic. There is also no consistent seasonal control on surge initiation or termination. We suggest that the differing styles of surge can be partly accounted for by individual glacier configurations and that while some characteristics of Karakoram surges are akin to thermally controlled surges elsewhere (e.g., Svalbard), the dominant surge mechanism remains unclear. We thus propose that these surges represent a spectrum of flow instabilities and the processes controlling their evolution may vary on a glacier by glacier basis.

  3. Age-dependent role of steroids in the regulation of growth of the hen follicular wall

    Directory of Open Access Journals (Sweden)

    Lebedev Vladimir A

    2010-02-01

    Full Text Available Abstract Background The ovaries are the primary targets of senescence effects in mammalian and avian species. In the present study, relationships between reproductive aging, sex steroids and the growth pattern of the pre-ovulatory follicle wall were investigated using young hens with long clutch (YLC, old hens with long clutch (OLC, old hens with short clutch (OSC, and old hens with interrupted long clutch (OILC. Methods Experiment 1: Hens were sacrificed 1.5 and 14.5 h after ovulation. Experiment 2: YLC and OILC hens were sacrificed 3.5 h after treatments with LH and/or aminoglutethimide (AG, an inhibitor of steroid synthesis. Volumes of pre-ovulatory follicles (F1-F5 and plasma concentrations of ovarian steroids were determined. Experiment 3: Granulosa and theca cells from F3 follicles of OSC and/or YLC hens were exposed in vitro to estradiol-17beta (E2, testosterone (T and LH and the proliferative activity of the cells was examined using CellTiter 96 Aqueous One Solution Assay. Results In YLC and OLC groups, the total volume of F1-F5 follicles rose between 1.5 and 14.5 h after ovulation (P 2 (P 2 and the follicular volume (P 2 (r = -0.54, P 2 enhanced proliferation of granulosa cells from YLC and OSC groups. The proliferative activity of granulosa and theca cells of YLC hens depended on the interaction between T and LH (P Conclusions These data indicate for the first time that the growth pattern of pre-ovulatory follicles during the ovulatory cycle changes in the course of reproductive aging. E2 seems to play a dual role in this adjustment; it stimulates the growth of the follicular wall in reproductive aged hens, whereas it may inhibit this process in young birds. T and LH are apparently involved in the growth regulation during the pre-ovulatory surge in young hens.

  4. Synchronization of ovulation in cyclic gilts with porcine luteinizing hormone (pLH) and its effects on reproductive function.

    Science.gov (United States)

    Degenstein, K L; O'Donoghue, R; Patterson, J L; Beltranena, E; Ambrose, D J; Foxcroft, G R; Dyck, M K

    2008-10-15

    The overall objective was to evaluate the use of porcine luteinizing hormone (pLH) for synchronization of ovulation in cyclic gilts and its effect on reproductive function. In an initial study, four littermate pairs of cyclic gilts were given altrenogest (15 mg/d for 14 d). Gilts received 500 microg cloprostenol (Day 15), 600 IU equine chorionic gonadotropin (eCG) (Day 16) and either 5mg pLH or saline (Control) 80 h after eCG. Blood samples were collected every 4h, from 8h before pLH/saline treatment to the end of estrus. Following estrus detection, transcutaneous real-time ultrasonography and AI, all gilts were slaughtered 6d after the estimated time of ovulation. Peak plasma pLH concentrations (during the LH surge), as well as the amplitude of the LH surge, were greater in pLH-treated gilts than in the control (P=0.01). However, there were no significant differences between treatments in the timing and duration of estrus, or the timing of ovulation within the estrous period. In a second study, 45 cyclic gilts received altrenogest for 14-18d, 600 IU eCG (24h after last altrenogest), and 5mg pLH, 750 IU human chorionic gonadotropin (hCG), or saline, 80 h after eCG. For gilts given pLH or hCG, the diameter of the largest follicle before the onset of ovulation (mean+/-S.E.M.; 8.1+/-0.2 and 8.1+/-0.2mm, respectively) was smaller than in control gilts (8.6+/-0.2mm, P=0.05). The pLH and hCG groups ovulated sooner after treatment compared to the saline-treated group (43.2+/-2.5, 47.6+/-2.5 and 59.5+/-2.5h, respectively; PpLH-treated gilts. Embryo quality (total cell counts and embryo diameter) was not significantly different among groups. In conclusion, pLH reliably synchronized ovulation in cyclic gilts without significantly affecting embryo quality.

  5. Storm surge variational assimilation model

    Directory of Open Access Journals (Sweden)

    Shi-li HUANG

    2010-06-01

    Full Text Available To eliminate errors caused by uncertainty of parameters and further improve capability of storm surge forecasting, the variational data assimilation method is applied to the storm surge model based on unstructured grid with high spatial resolution. The method can effectively improve the forecasting accuracy of storm surge induced by typhoon through controlling wind drag force coefficient parameter. The model is first theoretically validated with synthetic data. Then, the real storm surge process induced by the TC 0515 typhoon is forecasted by the variational data assimilation model, and results show the feasibility of practical application.

  6. Effect of exogenous LH pulses on the fate of the first dominant follicle in postpartum beef cows nursing calves.

    Science.gov (United States)

    Duffy, P; Crowe, M A; Boland, M P; Roche, J F

    2000-01-01

    Prolonged postpartum anoestrus in beef cows is due to failure of early dominant follicles to ovulate. It is hypothesized that this failure to ovulate is due to inadequate LH pulse frequency. The objective of this study was to determine whether administration of hourly LH pulses would cause the first dominant follicle to ovulate. In Expt 1, 16 cows received either saline (n = 8) or porcine LH (pLH; 50 micrograms h-1; n = 8) as hourly pulses for 3-5 days from the second day of dominance of the first dominant follicle (day 0). In Expt 2, 21 cows received either saline (n = 7), or 50 micrograms pLH (n = 7) or 100 micrograms pLH (n = 7) as hourly pulses for 3 days. Appropriate ovarian scanning and assays of blood samples were carried out. In Expt 1, the number of dominant follicles that underwent atresia was not affected by increasing the number of LH pulses, but the duration of dominance (days) of the first and second dominant follicles and maximum size (mm) of the second dominant follicle were increased (P pLH pulses (3.1 +/- 1.2 pg ml-1) compared with controls (1.2 +/- 0.2 pg ml-1). Four of eight treated cows had an anovulatory LH surge. The number of follicle waves to first ovulation was not different (P pLH treated cows (3.9 +/- 0.5). In Expt 2, four of seven cows given pulses of 100 micrograms pLH h-1 ovulated the first dominant follicle, and the interval from calving to first ovulation was decreased (P pLH h-1 or control treatments. In conclusion, hourly pulses of pLH from day 1 after dominance of the first dominant follicle in postpartum beef cows can either prolong dominance or induce it to ovulate. This finding supports the hypothesis that LH pulse frequency is a key determinant of the fate of the dominant follicle in the early postpartum period.

  7. 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

    of circadian or external timing cues, Bmal1(-/-) females continued to cycle in constant darkness albeit with increased cycle length and time spent in estrus. Because pituitary gonadotropes are the source of circulating LH and FSH, we assessed hypophyseal circadian clock function and found that female......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...... pituitaries rhythmically express clock components throughout all cycle-stages. To determine the role of the gonadotrope clock in the preovulatory LH and FSH surge process, we generated mice that specifically lack BMAL1 in gonadotropes (GBmal1KO). GBmal1KO females exhibited a modest elevation in both proestrus...

  8. 7 CFR 58.218 - Surge tanks.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Surge tanks. 58.218 Section 58.218 Agriculture....218 Surge tanks. If surge tanks are used for hot milk, and temperatures of product including foam being held in the surge tank during processing, is not maintained at a minimum of 150 °F, then two...

  9. Effect of epinephrine, norepinephrine and(or) GnRH on serum LH in prepuberal beef heifers.

    Science.gov (United States)

    Hardin, D R; Randel, R D

    1983-09-01

    Forty prepuberal Simmental X Brahman-Hereford heifers were utilized to determine the effects of epinephrine (E), norepinephrine (NE), gonadotropin releasing hormone (GnRH) or combinations of GnRH + E and GnRH + NE on serum luteinizing hormone (LH) concentrations. Animals were assigned randomly to one of five treatments with four replicates/treatment. Treatments consisted of I) 100 micrograms GnRH at time 0 (n = 8); II) 50 mg NE at time -15 and 0 (n = 8); III) 50 mg E at time -15 and 0 (n = 8); IV) 100 micrograms GnRH at time 0, plus 50 mg NE at time -15 and 0 (n = 8) and V) 100 micrograms GnRH at time 0, plus 50 mg E at time -15 and 0 (n = 8). All treatment compounds were administered im in 2 ml physiological saline and blood samples were collected via tail vessel puncture at -30, -15, 0, 15, 30, 45, 60, 90, 120, 180, 240, 300 and 360 min from GnRH injection. Treatment with NE or E alone had no effect (P greater than .10) on serum LH during the sampling period. The initial LH release to GnRH was altered (P less than .05) by concomitant treatment with NE (treatment IV) or E (treatment V). Magnitude of the LH release was reduced (P less than .01) by treatment V. Area under the LH surge was reduced (P less than .05) by treatment IV (NE) and V (E).

  10. 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.).

  11. Effects of estradiol-17beta administration on steady-state messenger ribonucleic acid (MRNA) encoding equine alpha and LH/CGbeta subunits in pituitaries of ovariectomized pony mares.

    Science.gov (United States)

    Sharp, D C; Wolfe, M W; Cleaver, B D; Nilson, J

    2001-03-15

    The process of sexual recrudescence in the springtime in mares is characterized by renewal of follicular growth and acquisition of steroidogenic competence. Concomitant with renewal of follicular steroidogenesis is re-establishment of LH biosynthesis and secretion. Research results from our laboratory indicate that increased estradiol and LH secretion occur in close temporal association before the first ovulation of the year. Therefore, the hypothesis tested in this experiment was that estrogen administration to ovariectomized pony mares during the equivalent time of early vernal transition would enhance LH biosynthesis as monitored by messenger ribonucleic acid (mRNA) encoding for the pituitary subunits of LH (alpha and LH/CGbeta). Mares were administered either sesame oil vehicle control, or estradiol (5 mg i.m. twice daily in sesame oil) for 3, 6 or 9 days, beginning on February 2. The pituitary glands were harvested, and examined for LH subunit mRNA by Northern Blot and slot blot analysis. There was a significant increase in LH secretion after 6 days of estradiol secretion compared with control vehicle administration. Similarly, there was a significant increase in both alpha and LH/CGbeta subunit mRNA when estradiol was administered for 9 days. These data indicate that estrogen stimulates LH subunit formation in mares during early equivalent vernal transition. These data do not, however, discriminate between a direct pituitary effect of estrogen, and a hypothalamic effect. Whether the surge of estradiol just prior to the first ovulation of the year is essential for the renewed biosynthesis of LH subunits cannot be determined from these data. However an important role of estrogen in the final stages of sexual recrudescence is indicated.

  12. Medvezhiy Glacier surge in 2011

    Directory of Open Access Journals (Sweden)

    V. M. Kotlyakov

    2012-01-01

    Full Text Available The paper presents results of monitoring of the Medvezhiy Glacier state for the period from its surge of 2001 to the last pulsation of 2011. This monitoring is performed based on the photographing made from the Russian section of the International Space Station. Features, used for prediction of the glacier last movement, are pointed out. The earlier determined characteristic property of the Medvezhiy Glacier change from a phase of recovering to that of its fast movement has been substantiated. Mean period of the glacier pulsations, estimated from observations for the last century, is 13.5 years. A surge of the glacier left tributary is recognized.

  13. Dune erosion during storm surges

    NARCIS (Netherlands)

    Van Thiel de Vries, J.S.M.

    2009-01-01

    Large parts of The Netherlands are protected from flooding by a narrow strip of sandy beaches and dunes. The aim of this thesis is to extend the existing knowledge of dune erosion during storm surges as it occurs along the Dutch coast. The thesis discusses: • A large scale dune erosion experiment to

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

    Energy Technology Data Exchange (ETDEWEB)

    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).

  15. Comments on metal oxide surge arresters surges energy absorption capacity

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, M.L.B. [Escola Federal de Engenharia de Itajuba, Minas Gerais (Brazil); Zanetta, L.C. Jr. [E. Politecnica Univ. de Sao Paulo, Sao Paulo (Brazil)

    1996-12-31

    This paper presents an approach to determine the energy absorption capacity of metal oxide surge arrester resistors. The proposed approach deals with the discharge current peak versus discharge current time relation. A testing method and a statistical evaluation are proposed. After determining the discharge current withstanding limit of the tested metal oxide resistors, the prospective energy absorption capacity limit is computed. Finally, comments on the obtained results are presented.

  16. Medvezhiy Glacier surge in 2011

    OpenAIRE

    V. M. Kotlyakov; L. V. Desinov

    2012-01-01

    The paper presents results of monitoring of the Medvezhiy Glacier state for the period from its surge of 2001 to the last pulsation of 2011. This monitoring is performed based on the photographing made from the Russian section of the International Space Station. Features, used for prediction of the glacier last movement, are pointed out. The earlier determined characteristic property of the Medvezhiy Glacier change from a phase of recovering to that of its fast movement has been substantiated...

  17. Lake Borgne Surge Barrier Study

    Science.gov (United States)

    2010-09-01

    Savant , and Darla C. McVan September 2010 Approved for public release; distribution is unlimited. ERDC/CHL TR-10-10 September 2010 Lake...Borgne Surge Barrier Study S. Keith Martin, Gaurav Savant , and Darla C. McVan Coastal and Hydraulics Laboratory U.S. Army Engineer Research and...conducted by Keith Martin, Dr. Gaurav Savant , and Darla C. McVan. This work was conducted at the Coastal and Hydraulics Laboratory (CHL) of the

  18. Understanding the role of LH: myths and facts.

    Science.gov (United States)

    Fischer, Robert

    2007-10-01

    This review summarizes a series of lectures given at a recent Continuing Medical Education meeting in Hamburg, Germany (May 2007), aiming to understand the role of luteinizing hormone (LH) in follicular development during the natural menstrual cycle and controlled ovarian stimulation. Clinical situations and target groups of patients who might benefit from LH supplementation during their ovarian stimulation were discussed and defined. The lectures updated knowledge on the physiology of LH during the normal menstrual cycle and the role of LH in ovarian stimulation. The concept of the 'LH window' was presented, and the use of LH supplementation in different groups of patients undergoing controlled ovarian stimulation was discussed, including those with advanced age, hypogonadotrophic hypogonadism, pituitary down-regulation and poor response. In addition, the different ways of using LH or human chorionic gonadotrophin supplementation in ovulation induction protocols were described.

  19. The worst moment of superposed surge wave in upstream series double surge tanks of hydropower station

    Science.gov (United States)

    Teng, Y.; Yang, J. D.; Guo, W. C.; Chen, J. P.

    2016-11-01

    It is a consensus to consider the superposed working conditions when calculating the surge wave in surge tank of hydropower station with long diversion tunnel. For the hydropower station with single surge tank, the method of determining the worst superposed moment is mature. However, for the hydropower station with upstream series double surge tanks, research in this field is still blank. Based on an engineering project, this paper investigated the worst moments and the control superposed working conditions about the maximum surge level and the minimum surge level of upstream series double surge tanks using numerical simulation. In addition, the incidence relations between the worst moment of superposed surge wave and the different areal array and distance between the two surge tanks are also carried out. The results showed that: With the decrease of the distance between auxiliary surge tank and upstream reservoir, the maximum values of the highest surge levels in the two surge tanks always reach close to but a little earlier than the bigger one time when the inflowing discharges of the two surge tanks reach the maximum. It is similar to the minimum values of lowest surge levels in the two surge tanks which also reach close to but a little later than the bigger one time when the outflowing discharges of the two surges reach the maximum. Moreover, the closer the area of auxiliary surge tank to the area of main surge tank is, the closer the worst moment to the bigger one time when inflow or outflow of the two surges reach the maximum will become.

  20. Gonadotropin-releasing hormone, estradiol, and inhibin regulation of follicle-stimulating hormone and luteinizing hormone surges: implications for follicle emergence and selection in heifers.

    Science.gov (United States)

    Haughian, James M; Ginther, O J; Diaz, Francisco J; Wiltbank, Milo C

    2013-06-01

    Mechanisms regulating gonadotropin surges and gonadotropin requirements for follicle emergence and selection were studied in heifers. Experiment 1 evaluated whether follicular inhibins regulate the preovulatory luteinizing hormone (LH)/follicle-stimulating hormone (FSH) surges elicited by gonadotropin-releasing hormone (GnRH) injection (Hour = 0) and the subsequent periovulatory FSH surge. Treatments included control (n = 6), steroid-depleted bovine follicular fluid (bFF) at Hour -4 (n = 6), and bFF at Hour 6 (n = 6). Gonadotropins in blood were assessed hourly from Hours -6 to 36, and follicle growth tracked by ultrasound. Consistent with inhibin independence, bFF at Hour -4 did not impact the GnRH-induced preovulatory FSH surge, whereas treatment at Hour 6 delayed onset of the periovulatory FSH surge and impeded growth of a new follicular wave. Experiment 2 examined GnRH and estradiol (E2) regulation of the periovulatory FSH surge. Treatment groups were control (n = 8), GnRH-receptor antagonist (GnRHr-ant, n = 8), and E2 + GnRHr-ant (n = 4). GnRHr-ant (acyline) did not reduce the concentrations of FSH during the periovulatory surge and early follicle development (8.0 mm) was prevented by GnRHr-ant. Addition of E2 delayed both the onset of the periovulatory FSH surge and emergence of a follicular wave. Failure to select a dominant follicle in the GnRHr-ant group was associated with reduced concentrations of LH but not FSH. Maximum diameter of F1 in controls (13.3 ± 0.5 mm) was greater than in both GnRHr-ant (7.7 ± 0.3 mm) and E2 + GnRHr-ant (6.7 ± 0.8 mm) groups. Results indicated that the periovulatory FSH surge stems from removal of negative stimuli (follicular E2 and inhibin), but is independent of GnRH stimulation. Emergence and early growth of follicles (until about 8 mm) requires the periovulatory FSH surge but not LH pulses. However, follicular deviation and late-stage growth of a single dominant follicle requires GnRH-dependent LH pulses.

  1. Surge-type glaciers: controls, processes and distribution

    OpenAIRE

    Sevestre, Heïdi

    2015-01-01

    Glacier surging is an internally triggered instability. Surge-type glaciers periodically alternate between long periods of slow flow (the quiescent phase) and short periods of fast flow (the surge phase). Surging yields down-glacier transport of mass and often results in large and sudden glacier advances.The surging phenomenon has always challenged the notion of normality in glacier flow dynamics. The mechanisms of surging remain poorly understood. Observation of different surge behaviors acr...

  2. 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.

  3. Observing storm surges from satellite altimetry

    Science.gov (United States)

    Han, Guoqi

    2016-07-01

    Storm surges can cause catastrophic damage to properties and loss of life in coastal communities. Thus it is important to enhance our capabilities of observing and forecasting storm surges for mitigating damage and loss. In this presentation we show examples of observing storm surges around the world using nadir satellite altimetry, during Hurricane Sandy, Igor, and Isaac, as well as other cyclone events. The satellite observations are evaluated against tide-gauge observations and discussed for dynamic mechanisms. We also show the potential of a new wide-swath altimetry mission, the Surface Water and Ocean Topography (SWOT), for observing storm surges.

  4. Medroxyprogesterone acetate is an effective oral alternative for preventing premature luteinizing hormone surges in women undergoing controlled ovarian hyperstimulation for in vitro fertilization.

    Science.gov (United States)

    Kuang, Yanping; Chen, Qiuju; Fu, Yonglun; Wang, Yun; Hong, Qingqing; Lyu, Qifeng; Ai, Ai; Shoham, Zeev

    2015-07-01

    To investigate the use of medroxyprogesterone acetate (MPA) to prevent LH surge during controlled ovarian hyperstimulation (COH) and to compare cycle characteristics and pregnancy outcomes in subsequently frozen-thawed ET (FET) cycles. A prospective controlled study. Tertiary-care academic medical center. Three hundred patients undergoing IVF/intracytoplasmic sperm injection treatment. In the study group, hMG and MPA were administered simultaneously beginning on cycle day 3. Ovulation was induced with a GnRH agonist or cotriggered by a GnRH agonist and hCG when dominant follicles matured. A short protocol was used in the control group. Viable embryos were cryopreserved for later transfer in both protocols. The primary outcome measure was the number of oocytes retrieved. Secondary outcomes included the number of mature oocytes, the incidence of premature LH surge, and clinical pregnancy outcomes from FETs. The number of oocytes retrieved in the study group was similar to those in the controls (9.9 ± 6.7 vs. 9.0 ± 6.0), and higher doses of hMG were administered. In the study group, LH suppression persisted during ovarian stimulation, and the incidence of premature LH surge was 0.7% (1/150). No statistically significant differences were found in the clinical pregnancy rates (47.8% vs. 43.3%), implantation rates (31.9% vs. 27.7%), and live-birth rates (42.6% vs. 35.5%) in the study group and controls. The results show that MPA is an effective oral alternative for the prevention of premature LH surge in woman undergoing COH. This finding will help establish a new regimen for ovarian stimulation in combination with embryo cryopreservation. ChiCTR-ONRC-14004419. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  5. 'Carriers of variant luteinizing hormone (V-LH) among 1593 Baltic men have significantly higher serum LH'.

    Science.gov (United States)

    Punab, A M; Grigorova, M; Punab, M; Adler, M; Kuura, T; Poolamets, O; Vihljajev, V; Žilaitienė, B; Erenpreiss, J; Matulevičius, V; Laan, M

    2015-05-01

    Luteinizing hormone (LH) is a pituitary heterodimeric glycoprotein essential in male and female reproduction. Its functional polymorphic variant (V-LH) is determined by two missense mutations (rs1800447, A/G, Trp8Arg; rs34349826, A/G, Ile15Thr) in the LH β-subunit encoding gene (LHB; 19q13.3; 1111 bp; 3 exons). Among women, V-LH has been associated with higher circulating LH and reduced fertility, but the knowledge of its effect on male reproductive parameters has been inconclusive. The objective of this study was to assess the effect of V-LH on hormonal, seminal and testicular parameters in the Baltic young men cohort (n = 986; age: 20.1 ± 2.1 years) and Estonian idiopathic infertility patients (n = 607; 35.1 ± 5.9 years). V-LH was detected by genotyping of the underlying DNA polymorphisms using PCR-RFLP combined with resequencing of a random subset of subjects. Genetic associations were tested using linear regression under additive model and results were combined in meta-analysis. No significant difference was detected between young men and infertility patients for the V-LH allele frequency (11.0 vs. 9.3%, respectively). V-LH was associated with higher serum LH in both, the young men cohort (p = 0.022, allelic effect = 0.26 IU/L) and the idiopathic infertility group (p = 0.008, effect = 0.59 IU/L). In meta-analysis, the statistical significance was enhanced (p = 0.0007, resistant to Bonferroni correction for multiple testing; effect = 0.33 IU/L). The detected significant association of V-LH with increased serum LH remained unchanged after additional adjustment for the SNPs previously demonstrated to affect LH levels (FSHB -211G/T, FSHR Asn680Ser, FSHR -29A/G). Additionally, a suggestive trend for association with reduced testicular volume was observed among young men, and with lower serum FSH among infertility patients. The V-LH carrier status did not affect sperm parameters and other circulating reproductive hormones. For the first time, we show a conclusive

  6. 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

  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 on...

  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 inc

  9. Compression station anti-surge system considerations

    Energy Technology Data Exchange (ETDEWEB)

    Kurz, Rainer; White, Robert C. [Solar Turbines Incorporated, Houston, TX (United States)

    2005-07-01

    Centrifugal compressor surge and its prevention have drawn significant attention in the literature. An important aspect of surge avoidance lies in the design of the compressor station and, in particular, the piping upstream and downstream of the compressor. Most anti-surge systems are perfectly capable of avoiding surge during normal operating conditions. However, unplanned emergency shutdowns present a significant challenge, and surge avoidance in these cases depends to a large degree on the station layout. Furthermore, the concepts used in the anti surge system (valves, piping, coolers) also impact the start-up of the station, or of individual units of the station. In this paper a simplified surge control system model is presented and used to develop simpler rules that help with proper sizing of upstream and downstream piping systems, as well as the necessary control element. Since the design of the surge control and recycle system also affects the start-up of units and stations, start-up considerations for stations with and without cooled recycle loops are discussed. (author)

  10. Luminescence dating of storm-surge sediment

    NARCIS (Netherlands)

    Cunningham, A.C.

    2011-01-01

    Geological evidence of storm surges has the potential to provide vital information on storm-surge risk. Sediment from the coastal dunes of the Netherlands contains evidence of extreme floods that occurred before reliable measurements of water level began. For these sediments to be useful in flood-ri

  11. Conductive surge testing of circuits and systems

    Science.gov (United States)

    Richman, P.

    1980-01-01

    Techniques are given for conductive surge testing of powered electronic equipment. The correct definitions of common and normal mode are presented. Testing requires not only spike-surge generators with a suitable range of open-circuit voltage and short-circuit current waveshapes, but also appropriate means, termed couplers, for connecting test surges to the equipment under test. Key among coupler design considerations is minimization of fail positives resulting from reduction in delivered surge energy due to the coupler. Back-filters and the lines on which they are necessary, are considered as well as ground-fault and ground potential rise. A method for monitoring delivered and resulting surge waves is mentioned.

  12. Dopamine control of LH release in the tench (Tinca tinca).

    Science.gov (United States)

    Podhorec, Peter; Socha, Magdalena; Sokolowska-Mikolajczyk, Miroslawa; Policar, Tomas; Svinger, Viktor W; Drozd, Borek; Kouril, Jan

    2012-01-01

    Tench (Tinca tinca) is apparently the only known member of the Cyprinidae in which ovulation is stimulated following administration of a low dose of GnRH analogue (GnRHa) without a dopamine inhibitor. This study evaluated LH release effectiveness of the most commonly used GnRHa and clarified whether LH secretion followed by ovulation is subject to inhibitory dopaminergic control in tench. Fish were intraperitoneally injected with three types of GnRHa, GnRHa with dopamine inhibitor metoclopramide (combined treatment), or the dopamine inhibitor metoclopramide alone. LH concentrations at five sampling times (0, 6, 12, 24, and 33 h) together with ovulation success and fecundity index were recorded. The combined treatment triggered an almost immediate LH release peak with a gradual decline, and resulted in a high ovulation rate. In contrast to the combined treatment, an application of GnRHa alone at 10 μg kg(-1) induced gradual increase of LH concentrations with peaks close to ovulation time, and with high ovulation success. Significant differences in LH concentrations at 6 and 12h and no differences in ovulation success were found between the combined and the GnRHa alone treatments. Metoclopramide alone induced a small increase in LH with no ovulation. The study presents clear evidence of dopaminergic control of LH release in tench, with a high ovulation rate obtained after application of GnRHa alone or in combination with dopamine inhibitor.

  13. Development and Evaluation of Storm Surge Ensemble Forecasting for the Philippines Using JMA Storm Surge Model

    Science.gov (United States)

    Lapidez, J. P. B.; Tablazon, J. P.; Lagmay, A. M. F. A.; Suarez, J. K. B.; Santiago, J. T.

    2014-12-01

    The Philippines is one of the countries most vulnerable to storm surge. It is located in the North-western Pacific basin which is the most active basin in the planet. An average of 20 tropical cyclones enters the Philippine area of responsibility (PAR) every year. The archipelagic nature of the country with regions having gently sloping coasts and shallow bays also contribute to the formation of extreme surges. Last November 2013, storm surge brought by super typhoon Haiyan severely damaged several coastal regions in the Visayan Islands. Haiyan left more than 6 300 casualties and damages amounting to more than $ 2 billion. Extreme storm surge events such as this highlight the need to establish a storm surge early warning system for the country. This study explores the development and evaluation of storm surge ensemble forecasting for the Philippines using the Japan Meteorological Agency (JMA) storm surge model. 36-hour, 24-hour, and 12-hour tropical cyclone forecasts are used to generate an ensemble storm surge forecast to give the most probable storm surge height at a specific point brought by an incoming tropical cyclone. The result of the storm surge forecast is compared to tide gauge record to evaluate the accuracy. The total time of computation and dissemination of forecast result is also examined to assess the feasibility of using the JMA storm surge model for operational purposes.

  14. Deficiencies in luteal function during re-initiation of cyclic breeding ...

    African Journals Online (AJOL)

    anoestrous ewes, stimulation of the pre-ovulatory follicle with PMSG, prior ... hand, the LH-sensitive thecal cells continued to divide for at .... the sensitivity of this organ to GnRH. ...... time relationships concerning oestrus, ovulation and electrical.

  15. Luteinizing hormone (LH) and prolactin-releasing pituitary tumor: possible malignant transformation of the LH cell line.

    Science.gov (United States)

    Spertini, F; Deruaz, J P; Perentes, E; Pelet, B; Gomez, F

    1986-05-01

    A pituitary tumor was diagnosed in a prepubertal 13-yr-old girl, who had elevated plasma LH (58 mIU/ml) and PRL (93 ng/ml) levels; decreased GH, ACTH, and FSH secretion; and diabetes insipidus. After surgery, plasma LH and PRL declined, but not to normal levels. Conventional external radiotherapy to the pituitary was immediately followed by a decrease in LH to prepubertal values (0.7 mIU/ml), while PRL levels became normal only after a long course of bromocriptine therapy. The pituitary tumor was composed of two distinct cell types: small polygonal cells, which were PRL positive by immunohistochemistry, and clusters of pleomorphic large frequently mitotic polynucleated cells, which were LH positive, some of them also being positive for the alpha-subunit or beta LH but not for beta FSH. Four years after surgery and radiotherapy, the patient deteriorated neurologically. Computed tomographic scan showed widespread frontal and periventricular tumor, which had the histological features of a poorly differentiated carcinoma. No PRL, LH, or alpha- or beta-subunits were detectable on immunocytochemistry. While the PRL-positive cells of the pituitary tumor displayed the histological and clinical features of PRL adenomas, the morphological characteristics of LH cells and the sharp decline of plasma LH levels after radiotherapy were suggestive of malignant transformation. In this context, the later brain tumor could have been the result of subependymal spread of the pituitary tumor after it lost its hormone-secreting capacity.

  16. Proteome dataset of pre-ovulatory follicular fluids from less fertile dairy cows

    Directory of Open Access Journals (Sweden)

    Maya Zachut

    2016-06-01

    Full Text Available This article contains raw and processed data related to research published in Zachut et al. (2016 [1]. Proteomics data from preovulatory follicles in cows was obtained by liquid chromatography-mass spectrometry following protein extraction. Differential expression between controls and less fertile cows (LFC was quantified using MS1 intensity based label-free. The only previous proteomic analysis of bovine FF detected merely 40 proteins in follicular cysts obtained from the slaughterhouse (Maniwa et al., 2005 [2], and the abundance of proteins in the bovine preovulatory FF remains unknown. Therefore, the objectives were to establish the first dataset of FF proteome in preovulatory follicles of cows, and to examine differentially expressed proteins in FF obtained in-vivo from preovulatory follicles of less fertile cows (also termed “repeat breeder” and control (CTL cows. The proteome of FF from 10 preovulatory follicles that were aspirated in vivo (estradiol/progesterone>1 was analyzed. This novel dataset contains 219 identified and quantified proteins in FF, consisting mainly of binding proteins, proteases, receptor ligands, enzymes and transporters. In addition, differential abundance of 8 proteins relevant to follicular function was found in LFC compared to CTL; these findings are discussed in our recent research article Zachut et al. (2016 [1]. The present dataset of bovine FF proteome can be used as a reference for any study involving disorders of follicular development in dairy cows or in comparative studies between species.

  17. Apoptotic and proliferative changes during induced atresia of pre-ovulatory follicles in the rat

    NARCIS (Netherlands)

    A.L.L. Durlinger (Alexandra); P. Kramer; B. Karels (Bas); J.A. Grootegoed (Anton); J.Th.J. Uilenbroek (Jan); A.P.N. Themmen (Axel)

    2000-01-01

    textabstractAtresia, a degenerative process through which many follicles are removed from the growing pool, involves apoptotic changes in the follicular granulosa cells. To identify histochemical markers of early stages of atresia, an in-vivo rat model was used which al

  18. The dynamics of surge in compression systems

    Indian Academy of Sciences (India)

    A N Vishwanatha Rao; O N Ramesh

    2007-02-01

    In air-compression systems, instabilities occur during operation close to their peak pressure-rise capability. However, the peak efficiency of a compression system lies close to this region of instability. A surge is a violent mode of instability where there is total breakdown of flow in the system and pressure-rise capability is lost drastically. Generally, all compression systems operate with a margin defined as the ‘surge margin’, and, consequently, system operational efficiency is lower. It is of interest to study compression-system surge to understand its dynamics in order to operate compression systems close to the instability for achieving high efficiency safely without encountering surge. Unsteady pressure data from a compression system, captured during surge oscillations, reveal many aspects of flow physics and are analysed to understand the surge dynamics of the system. A set of controlled experiments was conducted with a simple desktop experimental test set-up and essential aspects of surge dynamics have been characterised.

  19. Storm surge and tidal range energy

    Science.gov (United States)

    Lewis, Matthew; Angeloudis, Athanasios; Robins, Peter; Evans, Paul; Neill, Simon

    2017-04-01

    The need to reduce carbon-based energy sources whilst increasing renewable energy forms has led to concerns of intermittency within a national electricity supply strategy. The regular rise and fall of the tide makes prediction almost entirely deterministic compared to other stochastic renewable energy forms; therefore, tidal range energy is often stated as a predictable and firm renewable energy source. Storm surge is the term used for the non-astronomical forcing of tidal elevation, and is synonymous with coastal flooding because positive storm surges can elevate water-levels above the height of coastal flood defences. We hypothesis storm surges will affect the reliability of the tidal range energy resource; with negative surge events reducing the tidal range, and conversely, positive surge events increasing the available resource. Moreover, tide-surge interaction, which results in positive storm surges more likely to occur on a flooding tide, will reduce the annual tidal range energy resource estimate. Water-level data (2000-2012) at nine UK tide gauges, where the mean tidal amplitude is above 2.5m and thus suitable for tidal-range energy development (e.g. Bristol Channel), were used to predict tidal range power with a 0D modelling approach. Storm surge affected the annual resource estimate by between -5% to +3%, due to inter-annual variability. Instantaneous power output were significantly affected (Normalised Root Mean Squared Error: 3%-8%, Scatter Index: 15%-41%) with spatial variability and variability due to operational strategy. We therefore find a storm surge affects the theoretical reliability of tidal range power, such that a prediction system may be required for any future electricity generation scenario that includes large amounts of tidal-range energy; however, annual resource estimation from astronomical tides alone appears sufficient for resource estimation. Future work should investigate water-level uncertainties on the reliability and

  20. Physical attributes of hurricane surges and their role in surge warning

    Science.gov (United States)

    Irish, J. L.

    2012-12-01

    In the last decade, the US has experienced some of its largest surges and hurricane-related damages on record. Effective evacuation in advance of a hurricane strike requires accurate estimation of the hurricane surge hazard that effectively conveys risk not only to government decision makers but also to the general public. Two primary challenges exist with the current structure for surge warning. First, existing computational methods for developing accurate, quantitative surge forecasts, namely surge height and inundation estimation, are limited by time and computational resources. Second, due primarily to the popularity and wide use of the Saffir-Simpson wind scale to convey the complete hurricane hazard, the public's perception of surge hazard is inaccurate. Here, we use dimensionless scaling and hydrodynamics arguments to quantify the influence of hurricane variables and regional geographic characteristics on the surge response. It will be shown that hurricane surge primarily scales with the hurricane's central pressure, and size and with continental shelf width at the landfall location (Irish et al. 2009, Nat. Haz.; Song et al. in press, Nat. Haz.). Secondary influences include the hurricane's forward speed and path. The developed physical scaling is applied in two ways: (1) as a means for expanding the utility of computational simulations for real-time surge height forecasting and (2) as a means to convey relative surge hazard via a readily evaluated algebraic surge scale. In the first application, the use of this physical scaling to develop surge response functions (SRF) enables instantaneous algebraic calculation of maximum surge height at any location of interest for any hurricane meteorological condition, without loss of accuracy gained via high-resolution computational simulation. When coupled with joint probability statistics, the use of SRFs enables rapid development of continuous probability density functions for probabilistic surge forecasting (Irish

  1. 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.

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

    Science.gov (United States)

    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

  3. Emergency department surge capacity: recommendations of the Australasian Surge Strategy Working Group.

    Science.gov (United States)

    Bradt, David A; Aitken, Peter; Fitzgerald, Gerry; Swift, Roger; O'Reilly, Gerard; Bartley, Bruce

    2009-12-01

    For more than a decade, emergency medicine (EM) organizations have produced guidelines, training, and leadership for disaster management. However, to date there have been limited guidelines for emergency physicians (EPs) needing to provide a rapid response to a surge in demand. The aim of this project was to identify strategies that may guide surge management in the emergency department (ED). A working group of individuals experienced in disaster medicine from the Australasian College for Emergency Medicine Disaster Medicine Subcommittee (the Australasian Surge Strategy Working Group) was established to undertake this work. The Working Group used a modified Delphi technique to examine response actions in surge situations and identified underlying assumptions from disaster epidemiology and clinical practice. The group then characterized surge strategies from their corpus of experience; examined them through available relevant published literature; and collated these within domains of space, staff, supplies, and system operations. These recommendations detail 22 potential actions available to an EP working in the context of surge, along with detailed guidance on surge recognition, triage, patient flow through the ED, and clinical goals and practices. The article also identifies areas that merit future research, including the measurement of surge capacity, constraints to strategy implementation, validation of surge strategies, and measurement of strategy impacts on throughput, cost, and quality of care.

  4. Glacier surge mechanism: 1982-1983 surge of variegated glacier, alaska.

    Science.gov (United States)

    Kamb, B; Raymond, C F; Harrison, W D; Engelhardt, H; Echelmeyer, K A; Humphrey, N; Brugman, M M; Pfeffer, T

    1985-02-01

    The hundredfold speedup in glacier motion in a surge of the kind the kind that took place in Variegated Glacier in 1982-1983 is caused by the buildup of high water pressure in the basal passageway system, which is made possible by a fundamental and pervasive change in the geometry and water-transport characteristics of this system. The behavior of the glacier in surge has many remarkable features, which can provide clues to a detailed theory of the surging process. The surge mechanism is akin to a proposed mechanism of overthrust faulting.

  5. 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.

  6. 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

  7. 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

  8. Excitonic level structures of LH1 and LH2 of purple photosynthetic bacteria using an analytical approach

    Institute of Scientific and Technical Information of China (English)

    杨光参; 汪力; 杨国桢

    2003-01-01

    The excitonic level structure of a ring-like chain of dimers is discussed analytically in order to aid the understanding of the possible spectral properties of LH1 and LH2 of purple photosynthetic bacteria. Under the approximation of dipoledipole interaction between Bchls, the excitonic levels, bandwidths and energy gap between two Davydov subbands are expressed analytically in terms of interaction energies and configurational parameters of dipoles. Our model includes all the interactions between pigment molecules in the system. The oscillator strengths and circular dichroism (CD) for the excitonic states are also presented analytically. The simulated absorption and CD spectra of LH1 and LH2 complexes reproduce the main features of the measured results.

  9. 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

    2011-01-01

    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 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. PMID:21539791

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

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, Thomas A. Cohen [Free Univ. of Amsterdam (Netherlands); Vengris, Mikas [Vilnius Univ. (Lithuania); Novoderezhkin, Vladimir I. [A.N. Belozersky Inst. of Physico-Chemical Biology, Moscow State Univ. (Russia); Cogdell, Richard J. [Microbial Photosynthesis Laboratory, Glasgow Biomedical Research Centre, Univ. of Glasgow (United Kingdom); Hunter, C. Neil [Department of Molecular Biology and Biotechnology, Univ. of Sheffield, (United Kingdom); van Grondelle, Rienk [Free Univ. of Amsterdam (Netherlands)

    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 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.

  11. 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.

    ) for storm surge forecasting at the eastern coast of India. Flather (1994) has applied another analytical model of Holland (1980) for wind and pressure fields in the case of surge simulation, forced by April 1991 Bangladesh storm. The basic atmospheric... parameters remain the same in all the parameterization schemes of storm wind field. Storm Surge Model Storm surge operational models are in use for a long time for forecasting and warning of storm surge disasters bordering the coasts in the parts of northern...

  12. GLP-1 Increases Preovulatory LH Source and the Number of Mature Follicles, As Well As Synchronizing the Onset of Puberty in Female Rats.

    Science.gov (United States)

    Outeiriño-Iglesias, Verónica; Romaní-Pérez, Marina; González-Matías, Lucas C; Vigo, Eva; Mallo, Federico

    2015-11-01

    Control of estrous cycle and reproductive capacity involves a large number of central and peripheral factors, integrating numerous nutritional and metabolic signals. Here we show that glucagon-like peptide-1 (GLP-1), a peptide with anorexigenic and insulinotropic actions, and the GLP-1 receptor agonist Exendin-4 (Ex4) exert a regulatory influence on the gonadal axis, in both adult and prepubertal female rats. In adult rats, Glp-1 receptor expression varies during the estrous cycle at the hypothalamus, pituitary, and ovary. Furthermore, acute treatment with GLP-1 in the morning proestrus doubled the amplitude of the preovulatory LH surge, as well as influencing estradiol and progesterone levels along the estrous cycle. These changes provoked an important increase in the number of Graafian follicles and corpora lutea, as well as in the litter size. Conversely, Ex4 diminished the levels of LH, later producing a partial blockade at the preovulatory surge, yet not affecting either the number of mature follicles or corpora lutea. Chronic administration of low doses of GLP-1 to prepubertal rats synchronized vaginal opening and increased LH levels on the 35th day of life, yet at these doses it did not modify their body weight, food intake, or ovarian and uterine weight. By contrast, chronic exposure to Ex4 produced a significant reduction in ovarian and uterine weight, and serum LH, and the animals treated chronically with Ex4 showed no vaginal opening in the period studied. Overall, our results demonstrate that GLP-1 and Ex4 act on the gonadal axis, involving the hypothalamic kisspeptin system, to influence reproductive efficiency in female rats.

  13. 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 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 (Pram effect' and that supplementation has little effect on this response.

  14. From solitary wave to traveling surge

    Institute of Scientific and Technical Information of China (English)

    宋礼庭

    1995-01-01

    The solution of kinetic Alfven wave under action of anomalous resistance has two branches: the slow wave, VPsurge and the fast wave VP>VA cosθ will be in a wave-broken state. Such traveling surge structure is a typical self-organization phenomenon and its wave form is determined by parameter β which represents the magnitude of resistance. High β leads to shock-like structure and low β to the appearance of some solitary waves in front of the shock. According to the study on solitary wave, shock wave and traveling surge in conjunction with self-organization of nonlinear dynamics, a general definition of wave can be given.

  15. 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.

  16. Computer-assisted mapping of pyroclastic surges.

    Science.gov (United States)

    Malin, M C; Sheridan, M F

    1982-08-13

    Volcanic hazard maps of surge boundaries and deposit thickness can be created by using a simplified eruption model based on an "energy line" concept of pyroclastic surge and flow emplacement. Computer image-processing techniques may be used to combine three-dimensional representations of the energy relations of pyroclasts moving under the influence of gravity (defined by an "energy cone") with digital topographic models of volcanoes to generate theoretical hazard maps. The deposit boundary and thickness calculated for the 18 May 1980 eruption of Mount St. Helens are qualitatively similar to those actually observed.

  17. Adaptive Mesh Refinement for Storm Surge

    CERN Document Server

    Mandli, Kyle T

    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.

  18. ASASSN-15lh: The Most Luminous Supernova Ever Discovered

    CERN Document Server

    Dong, Subo; 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; Chen, Ping; Conseil, E; Danilet, A B; Falco, E; Grupe, D; Kiyota, S; Masi, G; Nicholls, B; Olivares, F; Pignata, G; Pojmanski, G; Simonian, G V; Szczygiel, D M; Wozniak, P R

    2015-01-01

    We report the discovery and early evolution of ASASSN-15lh, the most luminous supernova ever found. At redshift z=0.2326, ASASSN-15lh reached an absolute magnitude of M_{u,AB} ~ -23.5 and bolometric luminosity L_bol ~ 2.2x10^45 ergs/s, which is >~ 2 times more luminous than any previously known supernova. Its spectra match the hydrogen-poor sub-class of super-luminous supernovae (SLSNe-I), whose energy sources and progenitors are poorly understood. In contrast to known SLSNe-I, most of which reside in star-forming, dwarf galaxies, its host appears to be a luminous galaxy (M_V ~ -22; M_K ~ -25.1) with little star formation. In the two months since its first detection, ASASSN-15lh has radiated ~7.5x10^51 ergs, challenging the popular magnetar model for the engine of SLSNe-I.

  19. Storm surge and river interaction in etuaries

    Science.gov (United States)

    Maskell, J.

    2012-04-01

    In coastal areas, particularly in regions developed on estuaries, extreme river flow can combine with storm surges to present a combined hazard. This combined risk is likely to be more prominent in estuaries where fluvial fresh water input comes from catchments in hilly regions where the dependence of extreme river discharge and sea level elevation can be most statistically significant (Svensson and Jones, 2004). The risk associated with these combined coastal hazards could increase due to climate change if there were an increase in the frequency of extreme weather events. The global (IPCC, 2007) and local (Woodworth et al., 2009) rise in mean sea-level will increase the magnitude of extreme sea levels and surges will act on a higher coastal sea level and therefore increase the risk to coastal property and infrastructure. This may be associated with an increase in precipitation during extreme storm events which will have a large impact on river flooding. Therefore, the need for accurate operational forecasting of storm events will increase with the focus shifting to changes in the extreme 'tail end' of the distribution of storm events. Ideally an operational model that integrates storm surge, wave and fluvial forecasting with inundation and simulates their combined influence would be most effective for planning with respect to flood plain development, evacuation and flood defence. Current operational storm surge models are typically based on two-dimensional depth-averaged shallow water equations (Flather, 2000). Inundation models often use an approximation of the original shallow water equations which neglect the inertial terms (Prestininzi et al., 2011). These 2D flood plain inundation models are often coupled with a 1D model of the main channel of a river or estuary which permits the exchange of mass but assumes a limited exchange of momentum (Bates et al., 2005). A finite volume model (FVCOM) is used to investigate the combined influence of storm surge and river

  20. Positive feedback stabilization of centrifugal compressor surge

    NARCIS (Netherlands)

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

    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 stabiliz

  1. 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

  2. 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.

  3. Synthetic Fentanyl Fueling Surge in Overdose Deaths: CDC

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_160618.html Synthetic Fentanyl Fueling Surge in Overdose Deaths: CDC U.S. Surgeon ... News) -- Deaths from overdoses of the synthetic narcotic fentanyl have surged in recent years, U.S. health officials ...

  4. PERFORMANCE EVALUATION OF LOX AND LH2 TURBOPUMP TURBINES FOR A 10 TON THRUST LOX/LH2 ROCKET ENGINE

    OpenAIRE

    HASHIMOTO, Ryohei; Kamijo, Kenjiro; Watanabe, Yoshiaki; Hasegawa, Satoshi; Fujita, Toshihiko; 橋本, 亮平; 上絛, 謙二郎; 渡辺, 義明; 長谷川, 敏; 藤田, 敏彦

    1981-01-01

    The aerodynamic performance evaluation of the pump-drive turbines for a 10 ton thrust liquid oxygen and liquid hydrogen (LOX and LH2) gas generator cycle propulsion system, which has dual-shaft series turbines, was tested mainly using cold nitrogen gas. At design equivalent speed and pressure ratio, the LOX turbine static efficiency was about 35 percent compared to the design value of 32.8 percent. The LH2 turbine static efficiency was very close to the design value of 45 percent. Equivalent ...

  5. Extreme Supernova Models for the Superluminous Transient ASASSN-15lh

    CERN Document Server

    Chatzopoulos, E; Vinko, J; Nagy, A P; Wiggins, B K; Even, W P

    2016-01-01

    The recent discovery of the unprecedentedly superluminous transient ASASSN-15lh (or SN 2015L) challenges all the power-input models that have been proposed for superluminous supernovae. Here we examine some of the few viable interpretations of ASASSN-15lh in the context of a stellar explosion, involving combinations of one or more power inputs. We model the lightcurve of ASASSN-15lh with a hybrid model that includes contributions from magnetar spin-down energy and hydrogen-poor circumstellar interaction. We also investigate models of pure circumstellar interaction with a massive hydrogen-deficient shell and discuss about the lack of interaction features in the observed spectra. We find that ASASSN-15lh can be best modeled by the energetic core-collapse of a ~40 Msun supernova interacting with a hydrogen-poor shell of ~20 Msun. The circumstellar shell and progenitor mass are consistent with a rapidly rotating pulsational pair-instability supernova progenitor as required for strong interaction following the fin...

  6. 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.

  7. 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.

  8. 30 CFR 77.209 - Surge and storage piles.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Surge and storage piles. 77.209 Section 77.209... Installations § 77.209 Surge and storage piles. No person shall be permitted to walk or stand immediately above a reclaiming area or in any other area at or near a surge or storage pile where the...

  9. 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.

  10. 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

  11. Earth Observation in aid of surge monitoring and forecasting: ESA's eSurge Project

    Science.gov (United States)

    Harwood, Phillip; Cipollini, Paolo; Snaith, Helen; Høyer, Jacob; Dwyer, Ned; Dunne, Declan; Stoffelen, Ad; Donlon, Craig

    2013-04-01

    The understanding and realistic modelling of surges supports both preparation and mitigation activities and should eventually bring enormous societal benefits, especially to some of the world's poorest countries. Earth Observation data from satellites have an important role to play in storm surge monitoring and forecasting, but the full uptake of these data by the users (such as environmental agencies and tidal prediction centres) must be first encouraged by showcasing their usefulness, and then supported by providing easy access. The European Space Agency has recognized the above needs and, through its Data User Element (DUE) programme, has initiated in 2011 the eSurge project, whose aims are: a) to contribute through Earth Observation to an integrated approach to storm surge, wave, sea-level and flood forecasting as part of a wider optimal strategy for building an improved forecast and warning capability for coastal inundation; and b) to increase the use of the advanced capabilities of ESA and other satellite data for storm surge applications. The project is led by Logica UK, with NOC (UK), DMI (Denmark), CMRC (Ireland) and KNMI (Netherlands) as scientific partners. eSurge aims to provide easy access to a wide range of relevant data for a range of historical surge events, as well as performing a series of experiments to demonstrate the value of this data, and running workshops and training courses to help users make use of the available data. The eSurge database of Earth Observation and in situ measurements for past surge events is now publicly available. In 2013 the project moves into its service demonstration phase, adding more data and events, including a demonstration near real time service. The project works closely with its users in order to meet their needs and to maximise the return of this data. A novel dataset provided by eSurge is coastal altimetry. Coastal altimetry has a prominent role to play as it measures directly the total water level envelope

  12. The use of coastal altimetry to support storm surge studies in project eSurge

    Science.gov (United States)

    Cipollini, P.; Harwood, P.; Snaith, H.; Vignudelli, S.; West, L.; Zecchetto, S.; Donlon, C.

    2012-04-01

    One of the most promising applications of the new field of coastal altimetry, i.e. the discipline aiming to recover meaningful estimates of geophysical parameters (sea level, significant wave height and wind speed) from satellite altimeter data in the coastal zone, is the study of storm surges. The understanding and realistic modelling of surges supports both preparation and mitigation activities and should eventually bring enormous societal benefits, especially to some of the world's poorest countries (like Bangladesh). Earth Observation data have an important role to play in storm surge monitoring and forecasting, but the full uptake of these data by users (such as environmental agencies and tidal prediction centres) must first be encouraged by showcasing their usefulness, and then supported by providing easy access. Having recognized the above needs, The European Space Agency has recently launched a Data User Element (DUE) project called eSurge. The main purposes of eSurge are a) to contribute to an integrated approach to storm surge, wave, sea-level and flood forecasting through Earth Observation, as part of a wider optimal strategy for building an improved forecast and early warning capability for coastal inundation; and b) to increase the use of the advanced capabilities of ESA and other satellite data for storm surge applications. The project is led by Logica UK, with NOC (UK), DMI (Denmark), CMRC (Ireland) and KNMI (Netherlands) as scientific partners. A very important component of eSurge is the development, validation and provision of dedicated coastal altimetry products, which is the focus of the present contribution. Coastal altimetry has a prominent role to play as it measures the total water level envelope directly, and this is one of the key quantities required by storm surge applications and services. But it can also provide important information on the wave field in the coastal strip, which helps the development of more realistic wave models that in

  13. Guiding Surge Reduction Strategies via Characterization of Coastal Surge Propagation and Internal Surge Generation within a Complex Bay/Estuary System, Galveston Bay, TX

    Science.gov (United States)

    Bass, B.; Torres, J.; Irza, N.; Bedient, P. B.; Dawson, C.; Proft, J.

    2015-12-01

    In this study, Hurricane Ike (2008) and a suite of synthetic storms are simulated in order to evaluate how different hurricane landfalls, wind intensities, and radius to maximum winds influence the surge response in complex semi-enclosed bays such as Galveston Bay, located along the Texas Gulf Coast. The Advanced CIRCulation and Simulating Waves Nearshore (ADCIRC+SWAN) models are employed to quantify surge in terms of its relative coastal contributions that propagate across barrier islands and tidal inlets and subsequently into Galveston Bay, the surge generated locally within the Bay itself, and the interaction between these coastal and local components of surge. Results from this research will further the current understanding of surge interactions in bay systems and guide coastal engineering surge reduction projects that need to consider multiple lines of defense to protect complex bay/estuary systems such as Galveston Bay, TX.

  14. 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.

  15. Hypergravity induced prolactin surge in female rats

    Science.gov (United States)

    Megory, E.; Oyama, J.

    1985-01-01

    Acute initial exposure to hypergravity (HG) was previously found to induce prolonged diestrous in rats, which was followed by return to normal estrous cycling upon more prolonged exposure to continuous HG. Bromergocryptine was found to prevent this prolonged diestrous. In this study it is found that in female rats 20 h of 3.14 G exposure (D-1 1200 h until D-2 0800 h) can induce prolactin surge at D-2 1600 h. Shorter exposure time (8 h), or exposure during a different part of the estrous cycle (19 h: from D-1 0700 h until D-2 0200 h) could not elicit this prolactin surge. Similar exposure of male rats of HG did not alter significantly their prolactin levels. It is possible that the hypothalamus of male and female rats responds differently to stimulation by HG.

  16. Probabilistic Storm Surge Hazard Assessment in Martinique

    Science.gov (United States)

    Krien, Yann; Dudon, Bernard; Sansorgne, Eliot; Roger, Jean; Zahibo, Narcisse; Roquelaure, Stevie

    2013-04-01

    Located at the center of the Lesser Antilles, Martinique is under the threat of hurricanes formed over the warm tropical waters of the Atlantic Ocean and Caribbean Sea. These events can be extremely costly in terms of human, property, and economic losses. Storm surge hazard studies are hence required to provide guidance to emergency managers and decision-makers. A few studies have been conducted so far in the French Lesser Antilles, but they mainly rely on scarce historical data of extreme sea levels or numerical models with coarse resolutions. Recent progress in statistical techniques for generating large number of synthetic hurricanes as well as availability of high-resolution topographic and bathymetric data (LIDAR) and improved numerical models enables us today to conduct storm surge hazard assessment studies with much more accuracy. Here we present a methodology to assess cyclonic surge hazard in Martinique both at regional and local scales. We first simulate the storm surges that would be induced by a large set of potential events generated by the statistical/deterministic models of Emanuel et al. [2006]. We use the ADCIRC-SWAN coupled models (Dietrich et al 2012) to simulate inundation inland with grid resolutions of up to 50-100m in the coastal area for the whole island.These models are validated against observations during past events such as hurricane Dean in 2007. The outputs can then be used in some specific sites to force higher resolution models for crisis management and local risk assessment studies. This work is supported by the INTERREG IV « Caribbean » program TSUNAHOULE.

  17. Design and Characterization of a Centrifugal Compressor Surge Test Rig

    Directory of Open Access Journals (Sweden)

    Kin Tien Lim

    2011-01-01

    Full Text Available A detailed description of a new centrifugal compressor surge test rig is presented. The objective of the design and development of the rig is to study the surge phenomenon in centrifugal compression systems and to investigate a novel method of surge control by active magnetic bearing servo actuation of the impeller axial tip clearance. In this paper, we focus on the design, initial setup, and testing of the rig. The latter two include the commissioning of the rig and the experimental characterization of the compressor performance. The behavior of the compressor during surge is analyzed by driving the experimental setup into surge. Two fundamental frequencies, 21 Hz and 7 Hz, connected to the surge oscillation in the test rig are identified, and the observed instability is categorized according to the intensity of pressure fluctuations. Based on the test results, the excited pressure waves are clearly the result of surge and not stall. Also, they exhibit the characteristics of mild and classic surge instead of deep surge. Finally, the change in the compressor performance due to variation in the impeller tip clearance is experimentally examined, and the results support the potential of the tip clearance modulation for the control of compressor surge. This is the first such demonstration of the feasibility of surge control of a compressor using active magnetic bearings.

  18. 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.

  19. LH transition characteristics due to bipolar losses in tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Toda, Shinichiro [Interdisciplinary Graduate School of Engineering Sciences, Kyushu Univ., Kasuga, Fukuoka (Japan); Yagi, Masatoshi; Itoh, Sanae-I.

    1998-10-01

    The L/H transition theory is extended based on the electrostatic bifurcation. We study the bipolar losses which have not been examined as the transition mechanisms yet and investigate the L/H transition characteristics. The comparison study with the experimental results is also done. It is found that the equation of motions has the solutions with various hysteresis types of electrostatic bifurcation phenomena when the mechanisms of bipolar losses are considered. The dependences of the particle flux and the diffusivity on the thermodynamic force in the presence of the electric field are examined. ELMs (Edge Localizes Modes) phenomena which are typical in the H-mode are studied. The model equation is newly extended to include the effect of the electric field shear in addition to the electric field shear. This model is also extended to the dynamic model which includes the temporal evolution of the density from the static model with the hysteresis characteristics. (author)

  20. Levels of FSH, LH and testosterone, and sperm DNA fragmentation.

    Science.gov (United States)

    Wdowiak, Artur; Raczkiewicz, Dorota; Stasiak, Magdalena; Bojar, Iwona

    2014-01-01

    Having an offspring is the most important human biological goal, which is necessary for survival of the human species. Lack of offspring is a phenomenon concerning approximately 15% of married couples in Poland. In a half of the cases, a causative agent is the male factor infertility problem. There is evidence that certain male fertility problems are related with disorders of the process of spermatogenesis. The course of normal spermatogenesis depends on proper pituitary secretion of folliculostimulin (FSH), luteinizing hormone (LH), as well as testicular secretion of testosterone. It is considered that in approximately 20% of patients with idiopathic infertility an elevated level of sperm DNA fragmentation may be the cause of failure in reproduction. The objective of the present study was determination of the relationship between FSH, LH and testosterone levels, and the occurrence of sperm DNA fragmentation. The present study was conducted in the year 2012 in the Non-Public Health Care Unit 'Ovum Reproduction and Andrology' in Lublin, and covered 186 men treated for infertility. For inclusion into the study group we qualified males aged 25-35, who have been treated for infertility for more than 1 year, with no pathological features observed in the female partner. The structure of sperm chromatin was evaluated using the technique of flow cytometry-Sperm Chromatin Structure assay (SCSA). The result of the examination was a sperm DNA Fragmentation Index (DFI), i.e., the percentage of sperm with DNA lesions (DNA fragmentation). A morning blood sample (5 mL volume) was obtained and sent to an authorized laboratory to assess serum levels of testosterone, LH and FSH. An intensified sperm DNA fragmentation co-occurred with both extremely low and extremely high levels of FSH and LH. Sperm DNA fragmentation was negatively correlated with testosterone level.

  1. Towards a Physics-Based L-H Transition Model

    Science.gov (United States)

    Schmitz, L.; Rhodes, T. L.; Neiser, T.; Bardoczi, L.; Jenko, F.; Zeng, L.; Gohil, P.; Chrystal, C.; Grierson, B. A.; Eldon, D.; Yan, Z.; McKee, G. R.; Boedo, J.

    2016-10-01

    L-mode turbulence properties, collisionality, and ion transport fluxes across the separatrix are shown to determine the pre-transition ion poloidal and diamagnetic L-mode edge flow and the shear flow amplification triggering the L-H transition. L-mode ion thermal fluxes increase with density above the power threshold minimum, and are higher in hydrogen than in deuterium plasmas. The long-range toroidal ExB flow correlation at the L-H transition trigger time is observed to peak at intermediate plasma density around the L-H power threshold minimum, and is higher in D-plasmas in comparison to H-plasmas, indicating a possible link between trigger physics and power threshold. The turbulence-driven poloidal ion flow is found decisive for initial turbulence suppression, with a Reynolds stress gradient sufficiently large to account for the measured poloidal flow acceleration in the plateau collisionality. Supported by the US DOE under DE-FG02-08ER54984, DE-FC02-04ER54698, DE-AC02-09CH11466, DE-FG02-89ER53296, DE-FG02-07ER54917.

  2. Parallel Electron Force Balance and the L-H Transition

    Science.gov (United States)

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

    2016-10-01

    In a popular description of the L-H transition, energy transfer to the mean flows directly depletes turbulence fluctuation energy, resulting in suppression of the turbulence and a corresponding transport bifurcation. However, electron parallel force balance couples nonzonal velocity fluctuations with electron pressure fluctuations on rapid timescales, comparable with the electron transit time. For this reason, energy in the nonzonal velocity stays in a fairly fixed ratio to electron thermal free energy, at least for frequency scales much slower than electron transit. In order for direct depletion of the energy in turbulent fluctuations to cause the L-H transition, energy transfer via Reynolds stress must therefore drain enough energy to significantly reduce the sum of the free energy in nonzonal velocities and electron pressure fluctuations. At low k⊥, the electron thermal free energy is much larger than the energy in nonzonal velocities, posing a stark challenge for this model of the L-H transition. Work supported by U.S. DoE contract #DE-AC02-09CH11466.

  3. SALT Spectroscopy of ASASSN-15lh: The Most Luminous Supernova?

    Science.gov (United States)

    Court, Travis; Camacho, Yssavo; Dettman, Kyle; Jha, Saurabh W.

    2017-01-01

    In August 2015, ASASSN-15lh was discovered as the most luminous supernova (SN) ever found (Dong et al. 2016), more than twice as bright as other so-called super-luminous supernovae (SLSN). However, the spectral evolution of the transient is unlike any known supernova. To better understand this object, we have observed ASASSN-15lh with the Southern African Large Telescope (SALT). We obtained spectroscopic data in July 2016 and reduced and calibrated the spectrum for comparison with other supernovae. The new pectrum did not show strong supernova features and was dominated by light from the host galaxy. We used this late spectrum as a galaxy template, subtracting it from earlier data. However, we still find that ASASSN-15lh does not clearly resemble any known supernova. Either it is unique, or perhaps an alternate explanation is needed (e.g., a tidal disruption event; Leloudas et al. 2016). This Research Experience for Undergraduates project in the Department of Physics and Astronomy at Rutgers University has been supported by funding from National Science Foundation grants PHY-1263280 and PHY-1560077.

  4. 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...

  5. Climatic Controls on the Distribution of Surging Glaciers

    Science.gov (United States)

    Sevestre, H.; Benn, D.

    2012-12-01

    Surge-type glaciers are scattered in a non-random fashion, gathered in clusters in some glaciated regions. One group of clusters forms an Arctic and Sub-Arctic 'crescent', spanning from Alaska-Yukon, through Arctic Canada, West and East Greenland, Iceland, Svalbard and Novaya Zemlya. Another cluster occurs in western High Asia, including the Karakoram Mountains. Although several studies have assessed the influence of environmental controls on surging, so far none has provided a satisfactory explanation for the geographical location of these clusters. The distribution of such glaciers undoubtedly holds the keys of a better understanding on the controls on surging behaviour. For this study, two glacier populations are considered. First, a global inventory of glacier surges has been compiled, based on published observations, field reports and remote sensing studies. This digital database is structured in three tables, respectively providing information on the location and geometry of each surge-type glacier, surge dates and magnitude, and methodology employed at the time of observation. This global dataset is compared to the population of "non-surge-type glaciers" based on the Randolph Glacier Inventory version 2.0 excluding the inventoried surging glaciers. In both populations, glaciers are classified depending on their geometry and thermal regime. Downscaled climatic datasets are used to identify climatic envelopes associated with clusters of surging glaciers. We identified which environments are most prone to be associated to glacier surging, and examined the influence of these parameters on the surge cycle duration and character. These results emphasize the importance of external controls on surging (as against individual surges), and promote the need to study this behaviour in the frame of an energy-balance budget.

  6. Atlantic hurricane surge response to geoengineering

    Energy Technology Data Exchange (ETDEWEB)

    Moore, John C.; Grinsted, Aslak; Guo, Xiaoran; Yu, Xiaoyong; Jevrejeva, Svetlana; Rinke, Annette; Cui, Xuefeng; Kravitz, Ben; Lenton, Andrew; Watanabe, Shingo; Ji, Duoying

    2015-10-26

    Devastating Atlantic hurricanes are relatively rare events. However their intensity and frequency in a warming world may rapidly increase by a factor of 2-7 for each degree of increase in mean global temperature. Geoengineering by stratospheric sulphate aerosol injection cools the tropics relative to the polar regions, including the hurricane main development region in the Atlantic, suggesting that geoengineering may be an effective method of controlling hurricanes. We examine this hypothesis using 8 Earth System Model simulations of climate under the GeoMIP G3 and G4 schemes that use stratospheric aerosols to reduce the radiative forcing under the RCP4.5 scenario. Global mean temperature increases are greatly ameliorated by geoengineering, and tropical temperature increases are at most half of those in RCP4.5, but sulphate injection would have to double between 2020 and 2070 to balance RCP 4.5 to nearly 10 Tg SO2 yr-1, with consequent implications for damage to stratospheric ozone. We project changes in storm frequencies using a temperature-dependent Generalized Extreme Value statistical model calibrated by historical storm surges from 1923 and observed temperatures. The numbers of storm surge events as big as the one that caused the 2005 Katrina hurricane are reduced by about 50% compared with no geoengineering, but this is only marginally statistically significant. However, when sea level rise differences at 2070 between RCP4.5 and geoengineering are factored in to coastal flood risk, we find that expected flood levels are reduced by about 40 cm for 5 year events and perhaps halved for 50 year surges.

  7. Atlantic hurricane surge response to geoengineering.

    Science.gov (United States)

    Moore, John C; Grinsted, Aslak; Guo, Xiaoran; Yu, Xiaoyong; Jevrejeva, Svetlana; Rinke, Annette; Cui, Xuefeng; Kravitz, Ben; Lenton, Andrew; Watanabe, Shingo; Ji, Duoying

    2015-11-10

    Devastating floods due to Atlantic hurricanes are relatively rare events. However, the frequency of the most intense storms is likely to increase with rises in sea surface temperatures. Geoengineering by stratospheric sulfate aerosol injection cools the tropics relative to the polar regions, including the hurricane Main Development Region in the Atlantic, suggesting that geoengineering may mitigate hurricanes. We examine this hypothesis using eight earth system model simulations of climate under the Geoengineering Model Intercomparison Project (GeoMIP) G3 and G4 schemes that use stratospheric aerosols to reduce the radiative forcing under the Representative Concentration Pathway (RCP) 4.5 scenario. Global mean temperature increases are greatly ameliorated by geoengineering, and tropical temperature increases are at most half of those temperature increases in the RCP4.5. However, sulfate injection would have to double (to nearly 10 teragrams of SO2 per year) between 2020 and 2070 to balance the RCP4.5, approximately the equivalent of a 1991 Pinatubo eruption every 2 y, with consequent implications for stratospheric ozone. We project changes in storm frequencies using a temperature-dependent generalized extreme value statistical model calibrated by historical storm surges and observed temperatures since 1923. The number of storm surge events as big as the one caused by the 2005 Katrina hurricane are reduced by about 50% compared with no geoengineering, but this reduction is only marginally statistically significant. Nevertheless, when sea level rise differences in 2070 between the RCP4.5 and geoengineering are factored into coastal flood risk, we find that expected flood levels are reduced by about 40 cm for 5-y events and about halved for 50-y surges.

  8. Glacier surge after ice shelf collapse.

    Science.gov (United States)

    De Angelis, Hernán; Skvarca, Pedro

    2003-03-07

    The possibility that the West Antarctic Ice Sheet will collapse as a consequence of ice shelf disintegration has been debated for many years. This matter is of concern because such an event would imply a sudden increase in sea level. Evidence is presented here showing drastic dynamic perturbations on former tributary glaciers that fed sections of the Larsen Ice Shelf on the Antarctic Peninsula before its collapse in 1995. Satellite images and airborne surveys allowed unambiguous identification of active surging phases of Boydell, Sjögren, Edgeworth, Bombardier, and Drygalski glaciers. This discovery calls for a reconsideration of former hypotheses about the stabilizing role of ice shelves.

  9. Electrothermal model for complete metal-oxide surge arresters

    Energy Technology Data Exchange (ETDEWEB)

    Costa, E. Guedes da; Naidu, S.R. [UFPB, Dept. of Electrical Engineering, Campina Grande, PB (Brazil); Lima, A. Guedes de [CEFET-PB, Dept. of Mechanical Engineering, Joao Pessoa, PB (Brazil)

    2001-01-01

    A computational, electrothermal model for a complete metal-oxide surge arrester based on the implicit form of the finite-differences method is presented. The model is used to calculate the cooling curve after the application of overvoltages and the temperature variations during standard test. The model has been checked against experiments carried out on a test section and a complete surge arrester and the behaviour of a hypothetical surge arrester during standard tests simulated. (Author)

  10. Design and Characterization of a Centrifugal Compressor Surge Test Rig

    OpenAIRE

    2011-01-01

    A detailed description of a new centrifugal compressor surge test rig is presented. The objective of the design and development of the rig is to study the surge phenomenon in centrifugal compression systems and to investigate a novel method of surge control by active magnetic bearing servo actuation of the impeller axial tip clearance. In this paper, we focus on the design, initial setup, and testing of the rig. The latter two include the commissioning of the rig and the experimental characte...

  11. Performance Comparison of the European Storm Surge Models and Chaotic Model in Forecasting Extreme Storm Surges

    Science.gov (United States)

    Siek, M. B.; Solomatine, D. P.

    2009-04-01

    Storm surge modeling has rapidly developed considerably over the past 30 years. A number of significant advances on operational storm surge models have been implemented and tested, consisting of: refining computational grids, calibrating the model, using a better numerical scheme (i.e. more realistic model physics for air-sea interaction), implementing data assimilation and ensemble model forecasts. This paper addresses the performance comparison between the existing European storm surge models and the recently developed methods of nonlinear dynamics and chaos theory in forecasting storm surge dynamics. The chaotic model is built using adaptive local models based on the dynamical neighbours in the reconstructed phase space of observed time series data. The comparison focused on the model accuracy in forecasting a recently extreme storm surge in the North Sea on November 9th, 2007 that hit the coastlines of several European countries. The combination of a high tide, north-westerly winds exceeding 50 mph and low pressure produced an exceptional storm tide. The tidal level was exceeded 3 meters above normal sea levels. Flood warnings were issued for the east coast of Britain and the entire Dutch coast. The Maeslant barrier's two arc-shaped steel doors in the Europe's biggest port of Rotterdam was closed for the first time since its construction in 1997 due to this storm surge. In comparison to the chaotic model performance, the forecast data from several European physically-based storm surge models were provided from: BSH Germany, DMI Denmark, DNMI Norway, KNMI Netherlands and MUMM Belgium. The performance comparison was made over testing datasets for two periods/conditions: non-stormy period (1-Sep-2007 till 14-Oct-2007) and stormy period (15-Oct-2007 till 20-Nov-2007). A scalar chaotic model with optimized parameters was developed by utilizing an hourly training dataset of observations (11-Sep-2005 till 31-Aug-2007). The comparison results indicated the chaotic

  12. Simplified Storm Surge Simulations Using Bernstein Polynomials

    Science.gov (United States)

    Beisiegel, Nicole; Behrens, Jörn

    2016-04-01

    Storm surge simulations are vital for forecasting, hazard assessment and eventually improving our understanding of Earth system processes. Discontinuous Galerkin (DG) methods have recently been explored in that context, because they are locally mass-conservative and in combination with suitable robust nodal filtering techniques (slope limiters) positivity-preserving and well-balanced for the still water state at rest. These filters manipulate interpolation point values in every time step in order to retain the desirable properties of the scheme. In particular, DG methods are able to represent prognostic variables such as the fluid height at high-order accuracy inside each element (triangle). For simulations that include wetting and drying, however, the high-order accuracy will destabilize the numerical model because point values on quadrature points may become negative during the computation if they do not coincide with interpolation points. This is why the model that we are presenting utilizes Bernstein polynomials as basis functions to model the wetting and drying. This has the advantage that negative pointvalues away from interpolation points are prevented, the model is stabilized and no additional time step restriction is introduced. Numerical tests show that the model is capable of simulating simplified storm surges. Furthermore, a comparison of model results with third-order Bernstein polynomials with results using traditional nodal Lagrange polynomials reveals an improvement in numerical convergence.

  13. Hospital bioterrorism planning and burn surge.

    Science.gov (United States)

    Kearns, Randy D; Myers, Brent; Cairns, Charles B; Rich, Preston B; Hultman, C Scott; Charles, Anthony G; Jones, Samuel W; Schmits, Grace L; Skarote, Mary Beth; Holmes, James H; Cairns, Bruce A

    2014-01-01

    On the morning of June 9, 2009, an explosion occurred at a manufacturing plant in Garner, North Carolina. By the end of the day, 68 injured patients had been evaluated at the 3 Level I trauma centers and 3 community hospitals in the Raleigh/Durham metro area (3 people who were buried in the structural collapse died at the scene). Approximately 300 employees were present at the time of the explosion, when natural gas being vented during the repair of a hot water heater ignited. The concussion from the explosion led to structural failure in multiple locations and breached additional natural gas, electrical, and ammonia lines that ran overhead in the 1-story concrete industrial plant. Intent is the major difference between this type of accident and a terrorist using an incendiary device to terrorize a targeted population. But while this disaster lacked intent, the response, rescue, and outcomes were improved as a result of bioterrorism preparedness. This article discusses how bioterrorism hospital preparedness planning, with an all-hazards approach, became the basis for coordinated burn surge disaster preparedness. This real-world disaster challenged a variety of systems, hospitals, and healthcare providers to work efficiently and effectively to manage multiple survivors. Burn-injured patients served as a focus for this work. We describe the response, rescue, and resuscitation provided by first responders and first receivers as well as efforts made to develop burn care capabilities and surge capacity.

  14. Tide and skew surge independence: New insights for flood risk

    Science.gov (United States)

    Williams, Joanne; Horsburgh, Kevin J.; Williams, Jane A.; Proctor, Robert N. F.

    2016-06-01

    Storm surges are a significant hazard to coastal communities around the world, putting lives at risk and costing billions of dollars in damage. Understanding how storm surges and high tides interact is crucial for estimating extreme water levels so that we can protect coastal communities. We demonstrate that in a tidal regime the best measure of a storm surge is the skew surge, the difference between the observed and predicted high water within a tidal cycle. Based on tide gauge records spanning decades from the UK, U.S., Netherlands, and Ireland we show that the magnitude of high water exerts no influence on the size of the most extreme skew surges. This is the first systematic proof that any storm surge can occur on any tide, which is essential for understanding worst-case scenarios. The lack of surge generation dependency on water depth emphasizes the dominant natural variability of weather systems in an observation-based analysis. Weak seasonal relationships between skew surges and high waters were identified at a minority of locations where long-period changes to the tidal cycle interact with the storm season. Our results allow advances to be made in methods for estimating the joint probabilities of storm surges and tides.

  15. Auroral radio absorption and the westward travelling surge

    Energy Technology Data Exchange (ETDEWEB)

    Collis, P.N.; Korth, A.

    1983-11-01

    Measurements from a network of riometers during the passage of an auroral westward traveling surge are presented. These show that the energetic precipitation producing the radio absorption expands in an almost identical fashion to the softer precipitation associated with the visible surge; but it is delayed by about two minutes with respect to the surge. The delay is interpreted as a hardening of the precipitating electron spectrum as the surge goes by. Simultaneous observations of electrons at synchronous orbit are shown to support this conclusion. 24 references.

  16. Over 400 previously undocumented Svalbard surge-type glaciers identified

    Science.gov (United States)

    Farnsworth, Wesley R.; Ingólfsson, Ólafur; Retelle, Michael; Schomacker, Anders

    2016-07-01

    Identifying glaciers that exhibit surge-type behavior is important when using evidence of ice front fluctuations as a proxy for reconstructing past climate oscillations. This study identifies previously undocumented surge-type glaciers in Svalbard, based on the presence of crevasse squeeze ridges in glacier forelands. Crevasse squeeze ridges are landforms suggested to be unique to surging glacier land systems. Estimates vary greatly as to the actual percentage of surge-type glaciers in Svalbard, and consequently their distribution pattern is poorly understood. A detailed survey of recent (2008-2012), high-resolution aerial imagery from TopoSvalbard, provided by the Norwegian Polar Institute, allowed for a survey of all the glacier forelands in Svalbard. Before our study, 277 individual glaciers in Svalbard have been documented to exhibit surge behavior. By using crevasse squeeze ridges as indicators of surge behavior, we have identified 431 additional glaciers that have surged. We suggest that this is a modest value as the unique surge landforms were not visible in approximately one-third of the forelands with documented surge histories. Limits to the crevasse squeeze ridge technique are presented and potential controlling factors for crevasse squeeze ridge formation/preservation are discussed.

  17. On the magnitude and frequency of Karakoram Glacier surges

    Directory of Open Access Journals (Sweden)

    D. J. Quincey

    2013-10-01

    Full Text Available The return periods of Karakoram glacier surges are almost entirely unknown. Here, we present evidence of an historic surge of the Khurdopin Glacier that began in the mid-1970s and peaked in 1979. Measured surface displacements reached > 5 km yr–1, two orders of magnitude faster than during quiescence and twice as large as any previously recorded velocity in the region. The Khurdopin Glacier next surged in the late-1990s, equating to a return period of 20 yr. Surge activity in the region needs to be better understood if accurate mass balance assessments of Hindu-Kush–Karakoram–Himalaya glaciers are to be made.

  18. Probability of statistical L-H transition in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-08-01

    A statistical model of bifurcation of radial electric field E{sub r} is analyzed in relation with L-H transitions of tokamaks. A noise from micro fluctuations leads to random noise for E{sub r}. The transition of E{sub r} occurs in a probabilistic manner. Probability density function and ensemble average of E{sub r} are obtained, when hysteresis of E{sub r} exists. Forward- and backward-transition probabilities are calculated. The phase boundary is shown. Due to the suppression of turbulence by E{sub r} shear, the boundary deviates from the Maxwell's construction rule. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Toda, Shinichiro; Itoh, Kimitaka [National Inst. for Fusion Science, Toki, Gifu (Japan); Itoh, Sanae I.; Yagi, Masatoshi [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics; Fukuyama, Atsushi [Kyoto Univ. (Japan). Dept. of Nuclear Engineering

    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)

  20. Storm surges formation in the White and Barents Seas

    Science.gov (United States)

    Arkhipkin, Victor; Dobrolyubov, Sergey; Korablina, Anastasia; Myslenkov, Stanislav

    2016-04-01

    Investigation of storm surges in the Arctic seas are of high priority in Russia due to the active development of offshore oil and gas, construction of facilities in the coastal zone, as well as for the safety of navigation. It is important to study the variability of surges, to predict this phenomena and subsequent economic losses, thus including such information into the Russian Arctic Development Program 2020. Surges in the White and Barents Seas are caused mainly by deep cyclones of two types: "diving" from the north (88% of all cyclones) and western. The average height of the storm surges in the White Sea is 0.6-0.9 m. An average duration of storm surges is about 80 hours. Mathematical modeling is used to analyze the characteristics of storm surges formation in the Dvina Bay of the White Sea, and in the Varandey village on the Barents Sea coast. Calculating storm surge heights in the White and Barents seas is performed using the ADCIRC model on an unstructured grid with a step from 20 km in the Barents Sea to 100 m in the White Sea. Unstructured grids allowed keeping small features of the coastline of the White and Barents seas, small islands and shallow banks, and assessing their impact on the development and transformation of wind-generated waves. The ADCIRC model used data of wind field reanalysis CFSv2. The storm surges were simulated for the time period from 1979 to 2010 and included scenarios with / without direct atmospheric pressure forcing, waves and tides. Numerical experiments have revealed distribution of storm surges in channels of the Northern Dvina River delta. The storm surges spreads in the model from the north-north-west of the Dvina Bay. As storm surge moves from the wellhead to the seaside estuary of the Northern Dvina (district Solombala), its height increases from 0.5 to 2 m. We also found a non-linear interaction of the surge and tide during the phase of surge destruction. This phenomenon is the highest in the period of low water, and the

  1. Surges Initiated by Newly-emerging Satellite Magnetic Fields

    Science.gov (United States)

    Wang, Jun-feng; Zhou, Tuan-hui; Ji, Hai-sheng

    2014-01-01

    On July 22, 2011 and in the active region NOAA 11259 there ap- peared the event of the ejection of solar atmospheric Hα surges. According to the full-disc Hα observations of the Big Bear Solar Observatory in United States, three consecutive surges at one and the same place in the north of the main spot of the active region were discovered. The trajectories of these three surges exhib- ited the figure of straight lines, and their integral configuration is like an inverted Eiffel Tower. The first two surges are quite similar, and in each of them there appeared two bright points in the northern part of the main spot. After several minutes, the surges appeared in the midst of bright points. When the bright- ness of the bright points attained the maximum value, the surges spouted out from the midst of bright points. And after reaching the maximum altitude, they quickly vanished. Before the ejection of the third surge took place, no bright points appeared. Besides, its maximal altitude is merely one half of that of the first two surges. Via a comparison with the SDO/HMI (Solar Dynamics Obser- vatory/Helioseismic and Magnetic Imager) data of radial magnetic fields, it is found that in more than one hour before the appearance of the first surge there emerged bipolar magnetic fields in the region of ejection. Besides, in several min- utes before the ejection of each Hα surge the magnetic fluxes of positive polarity diminished. Via our analysis it is found that there appeared reconnections be- tween the newly emerging satellite magnetic fields and the preexisting magnetic fields in the spot, and this caused the continuous ejections of Hα surges.

  2. Overview of LH experiments in JET with an ITER-like wall

    Energy Technology Data Exchange (ETDEWEB)

    Kirov, K. K.; Baranov, Yu.; Brix, M.; Corrigan, G.; Mailloux, J.; Rimini, F.; Stamp, M. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Barbato, E. [Associazione EURATOM-ENEA sulla Fusione, C.R. Frascati, Roma (Italy); Ekedahl, A.; Goniche, M. [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France); Petrzilka, V. [Association EURATOM-IPP.CR, IPP AS CR, 182 21 Praha 8 (Czech Republic); Collaboration: JET EFDA Contributors

    2014-02-12

    An overview of the recent results of Lower Hybrid (LH) experiments at JET with the ITER-like wall (ILW) is presented. Topics relevant to LH wave coupling are addressed as well as issues related to ILW and LH system protections. LH wave coupling was studied in conditions determined by ILW recycling and operational constraints. It was concluded that LH wave coupling was not significantly affected and the pre-ILW performance could be recovered after optimising the launcher position and local gas puffing. SOL density measurements were performed using a Li-beam diagnostic. Dependencies on the D2 injection rate from the dedicated gas valve, the LH power and the LH launcher position were analysed. SOL density modifications due to LH were modelled by the EDGE2D code assuming SOL heating by collisional dissipation of the LH wave and/or possible ExB drifts in the SOL. The simulations matched reasonably well the measured SOL profiles. Observations of arcs and hotspots with visible and IR cameras viewing the LH launcher are presented.

  3. 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!

  4. 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.

  5. A MICROGAP SURGE ABSORBER FABRICATED USING CONVENTIONAL SEMICONDUCTOR TECHNOLOGY

    Institute of Scientific and Technical Information of China (English)

    李宏; 阮航宇

    2001-01-01

    A new type microgap surge absorber fabricated by only semiconductor technique has in it a special structure silicon chip which forms microgaps for gas discharge with electrodes, and has advantages such as small size, low cost, suitability for mass production besides the desirable characteristics that common microgap surge absorbers have. Applications of this absorber in communication facilities are discussed.

  6. Scenario-based Storm Surge Vulnerability Assessment of Catanduanes

    Science.gov (United States)

    Suarez, J. K. B.

    2015-12-01

    After the devastating storm surge effect of Typhoon Haiyan, the public recognized an improved communication about risks, vulnerabilities and what is threatened by storm surge. This can be provided by vulnerability maps which allow better visual presentations and understanding of the risks and vulnerabilities. Local implementers can direct the resources needed for protection of these areas. Moreover, vulnerability and hazard maps are relevant in all phases of disaster management designed by the National Disaster Risk Reduction Council (NDRRMC) - disaster preparedness, prevention and mitigation and response and recovery and rehabilitation. This paper aims to analyze the vulnerability of Catanduanes, a coastal province in the Philippines, to storm surges in terms of four parameters: population, built environment, natural environment and agricultural production. The vulnerability study relies on the storm surge inundation maps based on the Department of Science and Technology Nationwide Operational Assessment of Hazards' (DOST-Project NOAH) proposed four Storm Surge Advisory (SSA) scenarios (1-2, 3, 4, and 5 meters) for predicting storm surge heights. To determine total percent affected for each parameter elements, an overlay analysis was performed in ArcGIS Desktop. Moreover, vulnerability and hazard maps are generated as a final output and a tool for visualizing the impacts of storm surge event at different surge heights. The result of this study would help the selected province to know their present condition and adapt strategies to strengthen areas where they are found to be most vulnerable in order to prepare better for the future.

  7. Predicting Storm Surges: Chaos, Computational Intelligence, Data Assimilation, Ensembles

    NARCIS (Netherlands)

    Siek, M.B.L.A.

    2011-01-01

    Accurate predictions of storm surge are of importance in many coastal areas. This book focuses on data-driven modelling using methods of nonlinear dynamics and chaos theory for predicting storm surges. A number of new enhancements are presented: phase space dimensionality reduction, incomplete time

  8. The study of photo-induced ultrafast dynamics in light-harvesting complex LH2 of purple bacteria

    Institute of Scientific and Technical Information of China (English)

    LIU Wei-min; YAN Yong-li; LIU Kang-jun; XU Chun-he; QIAN Shi-xiong

    2006-01-01

    In this paper,we introduce the photo-induced ultrafast dynamics taking place in the peripheral light harvesting antenna LH2 from purple bacteria Rhodobacter sphaeroides by using absorption,fluorescence emission and ultrafast spectroscopic techniques.Three kinds of LH2 sampies,pH treated LH2 (complete removal of B800 pigments),carotenoid mutated LH2 (GM 309) and electrochemical oxidation treated LH2 were used in comparison with native LH2 to investigate the mechanism of photo-induced ultrafast energy transfer within the LH2 complex.

  9. Switching Surge Analysis of Vacuum Circuit Breaker using EMTP

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ik Mo; Kim, Ji Hong [Hyundai Heavy Industry, Mechatronics Research Institute (Korea)

    2000-07-01

    The first objective of this study is to set up the switching surge analysis method in motor driving distribution system. The simplified model which can simulate the motor energization and circuit breaker re-ignitions, and each circuit element model is presented in this paper. The second objective is to calculate the quantity of surge over-voltage in real nuclear power station. And the surge suppressing measures are verified on the simulation basis. It is clarified that most cases are not satisfactory to meet the IEEE standard 522-1992 without using surge suppressing measures. In cases that the surge arrester are installed in distribution board at the load side of circuit breaker. The IEEE specification is fully met. (author). 6 refs., 4 figs., 3 tabs.

  10. Investigation of Surge Behavior in a Micro Centrifugal Compressor

    Institute of Scientific and Technical Information of China (English)

    Shimpei MIZUKI; Yuichiro ASAGA; Yushi ONO; Hoshio TSUJITA

    2006-01-01

    This paper reports the experimental and theoretical study of the surge occurred in prototyping an ultra micro centrifugal compressor. As the first step, the 10 times size model of an ultra micro centrifugal compressor having the 40 mm outer diameter was designed and manufactured. The detailed experimental investigations for the transient behavior of surge with several different values of B parameter were carried out. The experimental results during the surge were compared with those obtained by the non-linear lumped parameter theory in order to validate the effectiveness of the theoretical surge model for the micro centrifugal compressor. As a result, the quite different behavior of the surge appeared for the different values of B both in the experiment and in the analysis.

  11. Application of short-data methods on extreme surge levels

    Science.gov (United States)

    Feng, X.

    2014-12-01

    Tropical cyclone-induced storm surges are among the most destructive natural hazards that impact the United States. Unfortunately for academic research, the available time series for extreme surge analysis are very short. The limited data introduces uncertainty and affects the accuracy of statistical analyses of extreme surge levels. This study deals with techniques applicable to data sets less than 20 years, including simulation modelling and methods based on the parameters of the parent distribution. The verified water levels from water gauges spread along the Southwest and Southeast Florida Coast, as well as the Florida Keys, are used in this study. Methods to calculate extreme storm surges are described and reviewed, including 'classical' methods based on the generalized extreme value (GEV) distribution and the generalized Pareto distribution (GPD), and approaches designed specifically to deal with short data sets. Incorporating global-warming influence, the statistical analysis reveals enhanced extreme surge magnitudes and frequencies during warm years, while reduced levels of extreme surge activity are observed in the same study domain during cold years. Furthermore, a non-stationary GEV distribution is applied to predict the extreme surge levels with warming sea surface temperatures. The non-stationary GEV distribution indicates that with 1 Celsius degree warming in sea surface temperature from the baseline climate, the 100-year return surge level in Southwest and Southeast Florida will increase by up to 40 centimeters. The considered statistical approaches for extreme surge estimation based on short data sets will be valuable to coastal stakeholders, including urban planners, emergency managers, and the hurricane and storm surge forecasting and warning system.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Risk Assessment of Hurricane Storm Surge for Tampa Bay

    Science.gov (United States)

    Lin, N.; Emanuel, K.

    2011-12-01

    Hurricane storm surge presents a major hazard for the United States and many other coastal areas around the world. Risk assessment of current and future hurricane storm surge provides the basis for risk mitigation and related decision making. This study investigates the hurricane surge risk for Tampa Bay, located on the central west coast of Florida. Although fewer storms have made landfall in the central west Florida than in regions farther west in the Gulf of Mexico and the east coast of U.S., Tampa Bay is highly vulnerable to storm surge due to its geophysical features. It is surrounded by low-lying lands, much of which may be inundated by a storm tide of 6 m. Also, edge waves trapped on the west Florida shelf can propagate along the coastline and affect the sea level outside the area of a forced storm surge; Tampa Bay may be affected by storms traversing some distance outside the Bay. Moreover, when the propagation speed of the edge wave is close to that of a storm moving parallel to the coast, resonance may occur and the water elevation in the Bay may be greatly enhanced. Therefore, Tampa Bay is vulnerable to storms with a broad spectrum of characteristics. We apply a model-based risk assessment method to carry out the investigation. To estimate the current surge risk, we apply a statistical/deterministic hurricane model to generate a set of 1500 storms for the Tampa area, under the observed current climate (represented by 1981-2000 statistics) estimated from the NCAR/NCEP reanalysis. To study the effect of climate change, we use four climate models, CNRM-CM3, ECHAM, GFDL-CM2.0, and MIROC3.2, respectively, to drive the hurricane model to generate four sets of 1500 Tampa storms under current climate conditions (represented by 1981-2000 statistics) and another four under future climate conditions of the IPCC-AR4 A1B emission scenario (represented by 2081-2100 statistics). Then, we apply two hydrodynamic models, the Advanced Circulation (ADCIRC) model and the Sea

  14. Dimerization of human lysyl hydroxylase 3 (LH3) is mediated by the amino acids 541-547.

    Science.gov (United States)

    Heikkinen, Jari; Risteli, Maija; Lampela, Outi; Alavesa, Paula; Karppinen, Marjo; Juffer, André H; Myllylä, Raili

    2011-01-01

    Lysyl hydroxylases (LH), which catalyze the post-translational modifications of lysines in collagen and collagen-like proteins, function as dimers. However, the amino acids responsible for dimerization and the role of dimer formation in the enzymatic activities of LH have not yet been identified. We have localized the region responsible for the dimerization of lysyl hydroxylase 3 (LH3), a multifunctional enzyme of collagen biosynthesis, to a sequence of amino acids between the glycosyltransferase activity and the lysyl hydroxylase activity domains. This area is covered by amino acids 541-547 in human LH3, but contains no cysteine residues. The region is highly conserved among LH isoforms, and is also involved in the dimerization of LH1 subunits. Dimerization is required for the LH activity of LH3, whereas it is not obligatory for the glycosyltransferase activities. In order to determine whether complex formation can occur between LH molecules originating from different species, and between different LH isoforms, double expressions were generated in a baculovirus system. Heterocomplex formation between mouse and human LH3, between human LH1 and LH3 and between human LH2 and LH3 was detected by western blot analyses. However, due to the low amount of complexes formed, the in vivo function of heterocomplexes remains unclear. Copyright © 2010 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

  15. Effect of different FSH/LH ratios on superovulatory response and embryo yield in goats

    Directory of Open Access Journals (Sweden)

    G. Martemucci

    2011-03-01

    Full Text Available Previous studies carried out in sheep (Chupin et al., 1985 and in goats (Nowshari et al., 1995; Martemucci et al., 1996 have underlined the importance of both FSH and LH to induce a good superovulatory response, but the results on the LH amount necessary to give a higher ovulatory response and embryo production are rather contradictory. The aim of this study was to evaluate, in goats, the effect of 2 different FSH/LH ratios (1:1 vs 2:1 kept constant during the treatment, on ovulatory response and embryo production. Moreover, according to the FSH/LH ratio=2:1,.........

  16. 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.

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

    CERN Document Server

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

    2013-01-01

    In this paper important aspects of 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. Concentration of W was analysed in more detail and it was concluded that LH contributes negligibly 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 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 troublefree operation of the LH system up to 2.5MW of coup...

  18. Evolution of surge levels inside of the Seine Bay : interactions between tide and surge levels during Johanna and Xynthia storms

    Science.gov (United States)

    Laborie, Vanessya; Sergent, Philippe

    2015-04-01

    Within the Technical Commission for the Study and the Evaluation of Maritime Submersions in the Seine Estuary (CTeeSMES), which aim is to improve the collective knowledge on physical processes related to maritime surge levels, a numerical model of the Atlantic French Coast based on TELEMAC2D was used to study the evolution of surge levels from the ocean to the harbour area of Le Havre and evaluate the interactions between tide and surge levels in the Seine Bay. The numerical model was specifically calibrated on JOHANNA and XYNTHIA storm events, which respectively occurred in March 2008 and in February 2010. To calibrate the global signal (tide + surge levels), measurements available on 18 outputs of the Atlantic coast were used to optimize the coefficient for wind influence and for bottom friction. Maritime boundary conditions were provided by the North East Atlantic Atlas (LEGOS). Winds and pressure fields were CFSR data. Once the numerical model had been calibrated both for tide and surge levels, it has been possible to draw the evolution of surge levels from the ocean to Le Havre (quai Meunier) and then to compare the signal obtained at each point of the Seine Bay with that obtained without taking into consideration tide for each event. That also allowed to evaluate the contribution of interactions between tide and surge levels inside of the Seine Bay for Xynthia and Johanna events, but also for other events in the slice [1979-2010] and considering climate change towards 2100 with IPCC5 scenarios. It appears that instantaneous interactions between tide and surge levels nearly reach 50 % of the global surge levels and can sharply influence the evolution of surge levels in the Seine Bay depending of the moment (high tide or low water) at which the storm occurs.

  19. 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.

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    G. E. Flowers

    2010-10-01

    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 (e.g. period, mechanism may depend on the glacier's environmental or climate setting. We examine the dynamics of a small (~5 km2 valley glacier in the Yukon Territory of 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 Coulomb-friction sliding law in both diagnostic and prognostic simulations. Diagnostic (force balance calculations capture the measured ice-surface velocity profile only when high basal water pressures (55–90% of flotation are prescribed over the central region of the glacier, consistent with where evidence of the surge has been identified. This leads to sliding accounting for 50–100% of the total surface motion. Prognostic simulations, where the glacier geometry evolves in response to a prescribed surface mass balance, reveal a significant role played by a large bedrock bump beneath the current equilibrium line of the glacier. This bump provides resistance to ice flow sufficient to cause the formation of a bulge in the ice-surface profile. We suggest that the bedrock bump contributes to the propensity for surges in this glacier, such that conditions suppressing ice-bulge formation over the bump may also inhibit surges. In our calculations such a situation arises for sufficiently negative values of mass balance. Collectively, these results corroborate our interpretation of the current glacier flow regime as indicative of a "slow surge", and confirm a relationship between surge incidence or character and the net mass balance. Our results also highlight the importance of glacier bed topography in controlling ice

  2. 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

  3. Surge of the Bivachny Glacier in 2012–2015

    Directory of Open Access Journals (Sweden)

    V. M. Kotlyakov

    2015-01-01

    Full Text Available The surge of the Bivachny Glacier that occurred in 2012–2015 is analyzed with the use of photographing performed from International Space Station in 2001–2015 together with data of the satellite monitoring of 1972–2000. This surge happened in 31 years after the similar previous event of 1972–1976. Dynamics of numerous glacier branches causing activation of the lower glacier part that is so called “dead” zone (more than 7 km in length is shown. Just before its stop the front part of the surging glacier had reached the main trunk of the Fedchenko Glacier. 

  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-t...

  5. Nanoscale Confinement and Fluorescence Effects of Bacterial Light Harvesting Complex LH2 in Mesoporous Silicas

    DEFF Research Database (Denmark)

    Ikemoto, Hideki; Tubasum, Sumera; Pullerits, Tonu;

    2013-01-01

    harvesting complex LH2 in nanoscale chemical environments. Mesoporous silicas (SBA-15 family) with different shapes and pore sizes were synthesized and used to create nanoscale biomimetic environments for molecular confinement of LH2. A combination of UV-vis absorption, wide-field fluorescence microscopy...

  6. U.S. Glaucoma Cases Expected to Surge by 2030

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_162924.html U.S. Glaucoma Cases Expected to Surge by 2030 Routine ... Medicine, the National Institutes of Health, or the U.S. Department of Health and Human Services. Recent Health ...

  7. Zika-Linked Birth Defects Surge in Colombia: CDC

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_162464.html Zika-Linked Birth Defects Surge in Colombia: CDC Study ... born with devastating birth defects linked to the Zika virus is no longer confined to Brazil, a ...

  8. Storm surge model based on variational data assimilation method

    Institute of Scientific and Technical Information of China (English)

    Shi-li HUANG; Jian XU; De-guan WANG; Dong-yan LU

    2010-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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 ..cap alpha..-modified Eagles medium followed by 24h in fresh medium +/- estradiol (E/sub 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/sub 2/(10/sup -11/ to 10/sup -8/M) on /sup 3/H-glucosamine (/sup 3/H-Gln) and /sup 35/S-methionine (/sup 35/S-Met) incorporation into LH +/- 1 nM GnRH (4h) were investigated. GnRH (10/sup -9/M) and E/sub 2/ (all doses) significantly increased total /sup 3/H-Gln LH. Moreover, E/sub 2/ at 10/sup -9/M and 10/sup -8/M significantly enhanced GnRH stimulated LH glycosylation. In contrast, addition of GnRH and/or E/sub 2/ did not significantly increase /sup 35/S-Met incorporation into LH over a 4h period. The effects of various GnRH concentrations (10/sup -11/ to 10/sup -9/M; 8h) +/- E/sub 2/ (0.05 nM) on /sup 3/H-Gln LH and /sup 35/S-Met LH production were also investigated. In the absence of E/sub 2/, only 10/sup -9/M GnRH was effective in increasing total /sup 3/H-Gln LH and /sup 35/S-Met LH synthesis. However, in the presence of E/sub 2/, all concentrations of GnRH stimulated LH synthesis with /sup 3/H-Gln LH production responding in a dose related manner whereas /sup 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 /sup 3/H-Gln or /sup 35/S-Met +/- GnRH. Removal of extracellular calcium completely inhibited GnRH stimulated /sup 3/H-Gln LH and /sup 35/S-Met LH production.

  10. Observations of cyclone-induced storm surge in coastal Bangladesh

    OpenAIRE

    Chiu, Soyee; Small, Christopher

    2015-01-01

    Water level measurements from 15 tide gauges in the coastal zone of Bangladesh are analyzed in conjunction with cyclone tracks and wind speed data for 54 cyclones between 1977 and 2010. Storm surge magnitude is inferred from residual water levels computed by subtracting modeled astronomical tides from observed water levels at each station. Observed residual water levels are generally smaller than reported storm surge levels for cyclones where both are available, and many cyclones produce no o...

  11. The surge-like eruption of a miniature filament

    Institute of Scientific and Technical Information of China (English)

    Jia-Yan Yang; Yun-Chun Jiang; Dan yang; Yi Bi; Bo Yang; Rui-Sheng Zheng; Jun-Chao Hong

    2012-01-01

    We report on the rare eruption of a miniature Hα filament that took the form of a surge.The filament first underwent a full development within 46 min and then began to erupt 9 min later,followed by a compact,impulsive X-ray class M2.2 flare with a two-ribbon nature only at the early eruption phase.During the eruption,its top rose,whereas the two legs remained rooted in the chromosphere and showed little swelling perpendicular to the rising direction.This led to a surge-like eruption with a narrow angular extent.Similar to the recent observations for standard and blowout X-ray jets by Moore et al.,we thus define it as a "blowout Hα surge." Furthermore,our observations showed that the eruption was associated with (1) a coronal mass ejection guided by a pre-existing streamer,(2) abrupt,significant,and persistent changes in the photospheric magnetic field around the filament,and (3) a sudden disappearance of a small pore.These observations thus provide evidence that a blowout surge is a small-scale version of a large-scale filament eruption in many aspects.Our observations further suggest that at least part of the Hα surges belong to blowout-type cases,and the exact distinction between the standard and blowout Hα surges is important in understanding their different origins and associated eruptive phenomena.

  12. Modeling and control of surge and rotating stall in compressors

    Energy Technology Data Exchange (ETDEWEB)

    Gravdahl, Jan Tommy

    1998-12-31

    Compressors are used in power generation and a variety of other applications. This thesis contains new results in the field of modeling and control of rotating stall and surge in compressors. A close coupled valve is included in the Moore-Greitzer compression system model and controllers for both surge and rotating stall is derived using backstepping. Disturbances, constant and time varying, are then taken into account, and non-linear controllers are derived. Stability results are given. Then, passivity is used to derive a simple surge control law for the closed coupled valve. This propositional control law is shown to stabilize the system even in the presence of time varying disturbances in mass flow and pressure. A novel model for an axial compression system with non-constant compressor speed is derived by extending the Moore-Greitzer model. Rotating stall and surge is studied in connection with acceleration of the compressor. Finally, a model for a centrifugal compression system with time varying compressor speed is derived. The variable speed compressor characteristic is derived based on energy losses in the compressor components. Active control of surge in connection with varying speed is studied. Semi-global exponential stability of the compression system with both surge and speed control is proven. 103 refs., 38 figs., 5 tabs.

  13. The role of mangroves in attenuating storm surges

    Science.gov (United States)

    Zhang, Keqi; Liu, Huiqing; Li, Yuepeng; Xu, Hongzhou; Shen, Jian; Rhome, Jamie; Smith, J.

    2012-01-01

    Field observations and numerical simulations indicate that the 6-to-30-km-wide mangrove forest along the Gulf Coast of South Florida effectively attenuated stormsurges from a Category 3 hurricane, Wilma, and protected the inland wetland by reducing an inundation area of 1800 km2 and restricting surge inundation inside the mangrove zone. The surge amplitude decreases at a rate of 40–50 cm/km across the mangrove forest and at a rate of 20 cm/km across the areas with a mixture of mangrove islands with open water. In contrast, the amplitudes of stormsurges at the front of the mangrove zone increase by about 10–30% because of the "blockage" of mangroves to surge water, which can cause greater impacts on structures at the front of mangroves than the case without mangroves. The mangrove forest can also protect the wetlands behind the mangrove zone against surge inundation from a Category 5 hurricane with a fast forward speed of 11.2 m/s (25 mph). However, the forest cannot fully attenuate stormsurges from a Category 5 hurricane with a slow forward speed of 2.2 m/s (5 mph) and reduced surges can still affect the wetlands behind the mangrove zone. The effects of widths of mangrove zones on reducing surge amplitudes are nonlinear with large reduction rates (15–30%) for initial width increments and small rates (<5%) for subsequent width increments.

  14. 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.

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

    Science.gov (United States)

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

    2010-06-01

    A summary of results from recent L-H power threshold (PLH) experiments in the National Spherical Torus Experiment is presented. First PLH (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 PLH/ne was comparable with neutral beam or rf heating, suggesting that rotation was not playing a dominant role in setting the value of PLH. The role of triangularity (δbot) in setting PLH/ne is less clear: while 50% less auxiliary heating power was required to access H-mode at low δbot than at high δbot, the high δbot discharges had lower ohmic heating and higher dW/dt, leading to comparable loss of power over a range of δbot. In addition, the dependences of PLH on the density, species (helium versus deuterium), plasma current, applied non-axisymmetric error fields and lithium wall conditioning are summarized.

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

    Energy Technology Data Exchange (ETDEWEB)

    Russell H. Bonn; Sigifredo Gonzalez

    2000-04-11

    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.

  17. Induction of an LH surge and ovulation by buserelin (as Receptal) allows breeding of weaned sows with a single fixed-time insemination

    NARCIS (Netherlands)

    Driancourt, M.A.; Cox, P.; Rubion, S.; Harnois-Milon, G.; Kemp, B.; Soede, N.M.

    2013-01-01

    The aim of this study was to demonstrate successful breeding of sows with a single fixed-time insemination following ovulation induction by buserelin, a GnRH analogue. In a first step, the optimal dose of buserelin (6, 10, or 16 µg) injected at 77 hours after weaning was determined in weaned sows (N

  18. Surge-type glaciers in the Tien Shan (Central Asia)

    Science.gov (United States)

    Mukherjee, Kriti; Bolch, Tobias

    2016-04-01

    Surge-type glaciers in High Mountain Asia are mostly observed in Karakoram and Pamir. However, few surge-type glaciers also exist in the Tien Shan, but have not comprehensively studied in detail in the recent literature. We identified surge-type glaciers in the Tien Shan either from available literature or by manual interpretation using available satellite images (such as Corona, Hexagon, Landsat, SPOT, IRS) for the period 1960 to 2014. We identified 39 possible surge-type glaciers, showing typical characteristics like looped moraines. Twenty-two of them rapidly advanced during different periods or a surge was clearly described in the literature. For the remaining possible surge-type glaciers either the advance, in terms of time and length, were not mentioned in detail in the literature, or the glaciers have remained either stable or retreated during the entire period of our study. Most of the surge-type glaciers cluster in the Inner Tien Shan (especially in the Ak-Shiirak rage) and the Central Tien Shan, are in size and are facing North, West or North West. Pronounced surge events were observed for North Inylchek and Samoilowitsch glaciers, both of which are located in the Central Tien Shan. Samoilowitsch Glacier retreated by more than 3 km between 1960 (length ~8.9 km) and 1992 (~5.8 km), advanced by almost 3 km until 2006 and slightly retreated thereafter. The most pronounced advance occurred between 2000 and 2002. DEM differencing (based on SRTM3 data and stereo Hexagon and Cartosat-1 data) revealed a significant thickening in the middle reaches (reservoir area) of the glacier between 1973 and 2000 while the surface significantly lowered in the middle and upper parts of the glacier between 2000 and 2006. Hence, the ice mass was transferred to the lower reaches (receiving area) and caused the advance with a maximum thickening of more than 80 m. The ~30 km long North Inylchek Glacier retreated since 1943 and showed a very rapid advance of ~3.5 km especially in

  19. The influence of climate during and after a glacial surge - A comparison of the last two surges of Fridtjovbreen, Svalbard

    Science.gov (United States)

    Lønne, Ida

    2014-02-01

    Glacial surges are periods of fast flow, often limited in space and time, and driven by internal conditions which are not fully explained. The quantity and variety of documented case-studies and settings demonstrate that the critical variables are difficult to isolate. In an alternative approach, two surges from the same basin were compared at Fridtjovhamna; one of the few known sites where this is possible. Fridtjovbreen is a polythermal glacier that has been through two recent surges: the last event (1991-2002) occurred during an unusually warm period in the high Arctic, whereas the previous surge culminated in 1861, around the Little Ice Age when many Svalbard-glaciers had their maximum Holocene extent. Based on a multi-disciplinary study, processes and landforms from the two episodes were compared with respect to ice-front movement rates, formation and decay of ice-cored moraines and glacial meltwater drainage patterns. The study demonstrates that moraines and meltwater traces from the oldest surge, locally well preserved, provide excellent opportunities for reconstructing the behavior of the ice-mass. The last surge, however, took place during a period with ablation rates never seen at this latitude, and 10 years after the maximum extent, the deglaciated areas onshore hardly show traces from the event.

  20. The Activities of Lysyl Hydroxylase 3 (LH3) Regulate the Amount and Oligomerization Status of Adiponectin

    Science.gov (United States)

    Ruotsalainen, Heli; Wang, Yu; Karppinen, Marjo; Bergmann, Ulrich; Kvist, Ari-Pekka; Pospiech, Helmut; Herzig, Karl-Heinz; Myllylä, Raili

    2012-01-01

    Lysyl hydroxylase 3 (LH3) has lysyl hydroxylase, galactosyltransferase, and glucosyltransferase activities, which are sequentially required for the formation of glucosylgalactosyl hydroxylysines in collagens. Here we demonstrate for the first time that LH3 also modifies the lysine residues in the collagenous domain of adiponectin, which has important roles in glucose and lipid metabolism and inflammation. Hydroxylation and, especially, glycosylation of the lysine residues of adiponectin have been shown to be essential for the formation of the more active high molecular weight adiponectin oligomers and thus for its function. In cells that totally lack LH3 enzyme, the galactosylhydroxylysine residues of adiponectin were not glucosylated to glucosylgalactosylhydroxylysine residues and the formation of high and middle molecular weight adiponectin oligomers was impaired. Circulating adiponectin levels in mutant mice lacking the lysyl hydroxylase activity of LH3 were significantly reduced, which indicates that LH3 is required for complete modification of lysine residues in adiponectin and the loss of some of the glycosylated hydroxylysine residues severely affects the secretion of adiponectin. LH mutant mice with reduced adiponectin level showed a high fat diet-induced increase in glucose, triglyceride, and LDL-cholesterol levels, hallmarks of the metabolic syndrome in humans. Our results reveal the first indication that LH3 is an important regulator of adiponectin biosynthesis, secretion and activity and thus might be a potential candidate for therapeutic applications in diseases associated with obesity and insulin resistance. PMID:23209641

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

    Energy Technology Data Exchange (ETDEWEB)

    Gregoraszczuk, Ewa L.; Slomczynska, Maria [Uniwersytet Jagiellonski, Cracow (Poland)

    1996-12-31

    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.

  2. Study of the bacterial diversity of foods: PCR-DGGE versus LH-PCR.

    Science.gov (United States)

    Garofalo, Cristiana; Bancalari, Elena; Milanović, Vesna; Cardinali, Federica; Osimani, Andrea; Sardaro, Maria Luisa Savo; Bottari, Benedetta; Bernini, Valentina; Aquilanti, Lucia; Clementi, Francesca; Neviani, Erasmo; Gatti, Monica

    2017-02-02

    The present study compared two culture-independent methods, polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) and length-heterogeneity polymerase chain reaction (LH-PCR), for their ability to reveal food bacterial microbiota. Total microbial DNA and RNA were extracted directly from fourteen fermented and unfermented foods, and domain A of the variable regions V1 and V2 of the 16S rRNA gene was analyzed through LH-PCR and PCR-DGGE. Finally, the outline of these analyses was compared with bacterial viable counts obtained after bacterial growth on suitable selective media. For the majority of the samples, RNA-based PCR-DGGE revealed species that the DNA-based PCR-DGGE was not able to highlight. When analyzing either DNA or RNA, LH-PCR identified several lactic acid bacteria (LAB) and coagulase negative cocci (CCN) species that were not identified by PCR-DGGE. This phenomenon was particularly evident in food samples with viable loadsPCR was able to detect a higher number of peaks in the analyzed food matrices relative to species identified by PCR-DGGE. In light of these findings, it may be suggested that LH-PCR shows greater sensitivity than PCR-DGGE. However, PCR-DGGE detected some other species (LAB included) that were not detected by LH-PCR. Therefore, certain LH-PCR peaks not attributed to known species within the LH-PCR database could be solved by comparing them with species identified by PCR-DGGE. Overall, this study also showed that LH-PCR is a promising method for use in the food microbiology field, indicating the necessity to expand the LH-PCR database, which is based, up to now, mainly on LAB isolates from dairy products. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. A High Density Storm Surge Monitoring Network: Evaluating the Ability of Wetland Vegetation to Reduce Storm Surge

    Science.gov (United States)

    Lawler, S.; Denton, M.; Ferreira, C.

    2013-12-01

    Recent tropical storm activity in the Chesapeake Bay and a potential increase in the predicted frequency and magnitude of weather systems have drawn increased attention to the need for improved tools for monitoring, modeling and predicting the magnitude of storm surge, coastal flooding and the respective damage to infrastructure and wetland ecosystems. Among other forms of flood protection, it is believed that coastal wetlands and vegetation can act as a natural barrier that slows hurricane flooding, helping to reduce the impact of storm surge. However, quantifying the relationship between the physical process of storm surge and its attenuation by wetland vegetation is an active area of research and the deployment of in-situ measuring devices is crucial to data collection efforts in this field. The United States Geological Survey (USGS) mobile storm-surge network has already successfully provided a framework for evaluating hurricane induced storm surge water levels on a regional scale through the use of in-situ devices installed in areas affected by storm surge during extreme events. Based on the success of the USGS efforts, in this study we adapted the monitoring network to cover relatively small areas of wetlands and coastal vegetation with an increased density of sensors. Groups of 6 to 10 water level sensors were installed in sites strategically selected in three locations on the Virginia coast of the lower Chesapeake Bay area to monitor different types of vegetation and the resulting hydrodynamic patterns (open coast and inland waters). Each group of sensors recorded time series data of water levels for both astronomical tide circulation and meteorological induced surge. Field campaigns were carried out to survey characteristics of vegetation contributing to flow resistance (i.e. height, diameter and stem density) and mapped using high precision GPS. A geodatabase containing data from field campaigns will support the development and calibration of

  4. 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)

  5. Cold surge: a sudden and spatially varying threat to health?

    Science.gov (United States)

    Yang, Tse-Chuan; Wu, Pei-Chih; Chen, Vivian Yi-Ju; Su, Huey-Jen

    2009-05-01

    While cold surge is one of the most conspicuous features of the winter monsoon in East Asia, its impact on human health remains underexplored. Based on the definition by the Central Weather Bureau in Taiwan, we identified four cold surges between 2000 and 2003 and collected the cardiovascular disease mortality data 2 weeks before and 2 weeks after these events. We attempted to answer the following research questions: 1) whether the cold surges impose an adverse and immediate effect on cardiovascular mortality; 2) whether the people living in temperate zones have a higher tolerance of extreme temperature drop than those in the subtropics. With geographic weighting techniques, we not only found that the cardiovascular disease mortality rates increased significantly after the cold surges, but also discovered a spatially varying pattern of tolerance to cold surges. Even within a small study area such as Taiwan, human reaction to severe weather drop differs across space. Needless to say, in the U.S., these findings should be considered in redirecting policy to address populations living in warm places when extreme temperature drops occur.

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

    Directory of Open Access Journals (Sweden)

    M. Braun

    2012-03-01

    Full Text Available A 2008–2011 surge of Bering Glacier, Alaska is examined using observations of surface velocity and surface elevation change. Velocity measurements are obtained using synthetic aperture radar (SAR offset tracking and elevation data are obtained from the University of Alaska Fairbanks LiDAR altimetry program. Bering Glacier began to surge in May 2008 and had two phases of accelerated flow. The first phase accelerated progressively for at least 10 months and reached peak observed velocities of ~7 m d−1. Results suggest that during the quiescent phase, prior to the surge, periods of accelerated flow increased driving stresses up to 70% in a ~10 km-long section of the Lower Bering. When the first phase of the surge initiated, synchronous acceleration occurred throughout much of the glacier length, indicating widespread pressurization of the bed, but the largest accelerations initiated at the location where driving stress built up during quiescence. From there, rapid flow velocities propagated upstream and downstream across much of the glacier length and transpired as small, transient and unorganized propagation fronts. The second phase occurred in 2011 and was of comparable scale to the surge in 1993–1995, with velocities exceeding 9 m d−1 or ~18 times quiescent velocities.

  7. Crystal structure of the RC-LH1 core complex from Rhodopseudomonas palustris.

    Science.gov (United States)

    Roszak, Aleksander W; Howard, Tina D; Southall, June; Gardiner, Alastair T; Law, Christopher J; Isaacs, Neil W; Cogdell, Richard J

    2003-12-12

    The crystal structure at 4.8 angstrom resolution of the reaction center-light harvesting 1 (RC-LH1) core complex from Rhodopseudomonas palustris shows the reaction center surrounded by an oval LH1 complex that consists of 15 pairs of transmembrane helical alpha- and beta-apoproteins and their coordinated bacteriochlorophylls. Complete closure of the RC by the LH1 is prevented by a single transmembrane helix, out of register with the array of inner LH1 alpha-apoproteins. This break, located next to the binding site in the reaction center for the secondary electron acceptor ubiquinone (UQB), may provide a portal through which UQB can transfer electrons to cytochrome b/c1.

  8. Storm surges in the Western Black Sea. Operational forecasting

    Directory of Open Access Journals (Sweden)

    G. MUNGOV

    2012-12-01

    Full Text Available The frequency of the storm surges in the Black Sea is lower than that in other regions of the World Ocean but they cause significant damages as the magnitude of the sea level set-up is up to 7-8 times greater than that of other sea level variations. New methods and systems for storm surge forecasting and studying their statistical characteristics are absolutely necessary for the purposes of the coastal zone management. The operational forecasting storm surge model of Meteo-France was adopted for the Black Sea in accordance with the bilateral agreement between Meteo-France and NINMH. The model was verified using tide-gauge observations for the strongest storms observed along the Bulgarian coast over the last 10 years.

  9. Observations of cyclone-induced storm surge in coastal Bangladesh

    CERN Document Server

    Chiu, Soyee

    2015-01-01

    Water level measurements from 15 tide gauges in the coastal zone of Bangladesh are analyzed in conjunction with cyclone tracks and wind speed data for 54 cyclones between 1977 and 2010. Storm surge magnitude is inferred from residual water levels computed by subtracting modeled astronomical tides from observed water levels at each station. Observed residual water levels are generally smaller than reported storm surge levels for cyclones where both are available, and many cyclones produce no obvious residual at all. Both maximum and minimum residual water levels are higher for west-landing cyclones producing onshore winds and generally diminish for cyclones making landfall on the Bangladesh coast or eastward producing offshore winds. Water levels observed during cyclones are generally more strongly influenced by tidal phase and amplitude than by storm surge alone. In only 7 of the 15 stations does the highest plausible observed water level coincide with a cyclone. While cyclone-coincident residual water level ...

  10. 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.

  11. 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...

  12. 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.

  13. Wave-Tide-Surge Coupled Simulation for Typhoon Maemi

    Institute of Scientific and Technical Information of China (English)

    Byung Ho Choi; Byung Il Min; Kyeong Ok Kim; Jin Hee Yuk

    2013-01-01

    The main task of this study focuses on studying the effect of wave-current interaction on currents,storm surge and wind wave as well as effects of current induced wave refraction and current on waves by using numerical models which consider the bottom boundary layer and sea surface roughness parameter for shallow and smooth bed area around Korean Peninsula.The coupled system (unstructured-mesh SWAN wave and ADCIRC) run on the same unstructured mesh.This identical and homogeneous mesh allows the physics of wave-circulation interactions to be correctly resolved in both models.The unstructured mesh can be applied to a large domain allowing all energy from deep to shallow waters to be seamlessly followed.There is no nesting or overlapping of structured wave meshes,and no interpolation is required.In response to typhoon Maemi (2003),all model components were validated independently,and shown to provide a faithful representation of the system's response to this storm.The waves and storm surge were allowed to develop on the continental shelf and interact with the complex nearshore environment.The resulting modeling system can be used extensively for prediction of the typhoon surge.The result show that it is important to incorporate the wave-current interaction effect into coastal area in the wave-tide-surge coupled model.At the same time,it should consider effects of depth-induced wave breaking,wind field,currents and sea surface elevation in prediction of waves.Specially,we found that:(1) wave radiation stress enhanced the current and surge elevation otherwise wave enhanced nonlinear bottom boundary layer decreased that,(2) wind wave was significantly controlled by sea surface roughness thus we cautiously took the experimental expression.The resulting modeling system can be used for hindcasting (prediction) the wave-tide-surge coupled environments at complex coastline,shallow water and fine sediment area like areas around Korean Peninsula.

  14. Regulation of endometrial cancer cell growth by luteinizing hormone (LH) and follicle stimulating hormone (FSH)

    OpenAIRE

    Davies, S.; Bax, C M R; Chatzaki, E; Chard, Tim; Iles, Ray K.

    2000-01-01

    Gonadotrophin releasing hormone analogues (GnRHa) have been used to treat recurrent endometrial cancer. However, the mode of action is uncertain. Our previous studies showed no direct effect of GnRHa on endometrial cancer cell growth in vitro. We have now examined the effect of luteinizing hormone (LH) and follicle stimulating hormone (FSH) on endometrial cancer cell growth. The aim was to determine whether suppression of pituitary LH and FSH by GnRHa could explain the tumour regression seen ...

  15. Into the Surge of Network-driven Innovation

    DEFF Research Database (Denmark)

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

    2013-01-01

    The ambition of this paper is to provide a better theoretical understanding of innovation by framing it in a long historical, economical, and societal perspective. The research question of the paper is: What characterize the historical surges of innovation? Based on previous works and research...... 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...

  16. Probabilistic Storm Surge Hazard Assessment in the French West Indies

    Science.gov (United States)

    Krien, Y.; Dudon, B.; Roger, J.; Zahibo, N.; Arnaud, G.

    2016-12-01

    The French West Indies are prone to hurricanes formed over the warm tropical waters of the Atlantic Ocean and Caribbean Sea. These events can have great consequences in terms of human, property, and economic losses. Storm surge hazard assessment is therefore required to provide guidance to emergency managers and decision-makers. By combining statistical-deterministic approaches and wave-current coupled models, we assessed storm surge hazard in Guadeloupe and Martinique islands. We present here the methodology, the results, as well as the on-going work on the impact of climate change in the framework of the FEDER-funded project C3AF.

  17. A High Resolution Forecast Model of Storm Surge Inundation

    Institute of Scientific and Technical Information of China (English)

    LIU Juan; JIANG Wensheng; SUN Wenxin; WANG Yongzhi

    2005-01-01

    In order to forecast storm surge inundation, a two-dimensional model is established. In the model, an alternating computation sequence method is used to solve the governing equations, and the dry and wet method is introduced to treat the moving boundary. This model is easy to use. It has a friendly input interface and Arcview GIS is used as the output interface. The model is applied to the Shantou area to simulate the storm surge elevations and inundations caused by Typhoons 6903 ane 0104 using the same relevant parameters. The calculated results agree well with the observations.

  18. Surge of the Bivachny Glacier in 2012–2015

    OpenAIRE

    V. M. Kotlyakov; L. V. Desinov; V. A. Rudakov

    2015-01-01

    The surge of the Bivachny Glacier that occurred in 2012–2015 is analyzed with the use of photographing performed from International Space Station in 2001–2015 together with data of the satellite monitoring of 1972–2000. This surge happened in 31 years after the similar previous event of 1972–1976. Dynamics of numerous glacier branches causing activation of the lower glacier part that is so called “dead” zone (more than 7 km in length) is shown. Just before its stop the front part of the surgi...

  19. Geological Controls on Glacier Surging?: Statistics and Speculation

    Science.gov (United States)

    Flowers, G. E.; Crompton, J. W.

    2015-12-01

    Glacier surging represents an end-member behavior in the spectrum of ice dynamics, involving marked acceleration and high flow speeds due to abrupt changes in basal mechanics. Though much effort has been devoted to understanding the role of basal hydrology and thermal regime in fast glacier flow, fewer studies have addressed the potential role of the geologic substrate. One interesting observation is that surge-type glaciers appear almost universally associated with unconsolidated (till) beds, and several large-scale statistical studies have revealed correlations between glacier surging and bedrock properties. We revisit this relationship using field measurements. We selected 20 individual glaciers for sampling in a 40x40 km region of the St. Elias Mountains of Yukon, Canada. Eleven of these glaciers are known to surge and nine are not. The 20 study glaciers are underlain by lithologies that we have broadly classified into two types: metasedimentary only and mixed metasedimentary-granodiorite. We characterized geological and geotechnical properties of the bedrock in each basin, and analyzed the hydrochemistry and mineralogy and grain size distribution (GSD) of the suspended sediments in the proglacial streams. Here we focus on some intriguing results of the GSD analysis. Using statistical techniques, including significance testing and principal component analysis, we find that: (1) lithology determines GSD for non-surge-type glaciers, with metasedimentary basins associated with finer mean grain sizes and mixed-lithology basins with coarser mean grain sizes, but (2) the GSDs associated with surge-type glaciers are intermediate between the distributions described above, and are statistically indistinguishable between metasedimentary and mixed lithology basins. The latter suggests either that surge-type glaciers in our study area occur preferentially in basins where various processes conspire to produce a characteristic GSD, or that the surge cycle itself exerts an

  20. 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

    BACKGROUND: The role of LH in sensitizing antral follicles to FSH is unclear. LH is required for normal hormone production and normal oocyte and embryo development, but follicular responses to LH may depend upon the stage of development. Potential roles at the early follicular phase were explored...... 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...

  1. Methodologic basis for the radioimmunoassay of endogenous LH-like activity in human prostatic tissue

    Energy Technology Data Exchange (ETDEWEB)

    Dorobek, W.; Misiorowski, W.; Niewiadomska, A.; Baranowska, B.; Zgliczynski, S.; Kuzaka, B.; Krzeski, T.

    1983-12-01

    The aim of this study was to develop a technique for the radioimmunological determination of the activity of LH-like substances in the human prostate. The material comprised 19 specimens of prostatic tissue obtained during transbladder extirpation in patients with benign prostatic hyperplasia. Tissues of human testes and human skeletal muscle were used as controls. The method adopted for LH extraction from the membrane fraction of human prostatic tissue appeared to be sufficiently specific, accurate and sensitive for routine laboratory investigations. The concentrations of the LH-like immunoreactivity in human testicular tissue was found to be 57, 46 and 70 mU per g of the membrane fraction while those of the prostatic gland tissues ranged from 34 to 155 mU per g of the membrane fraction. However such LH-like substance was not found in human skeletal muscle tissue. It seems that the LH-type activity is an indirect proof for the existence of LH receptors in the human prostate.

  2. Leaf Downward Curvature and Delayed Flowering Caused by AtLH Overexpression in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    WUHao; YULin; TANGXiang-Rong; SHENRui-Juan; HEYu-Ke

    2004-01-01

    AtLHgene of Arabidopsis is a BcpLH(leafy head) homolog of Chinese cabbage, which encodes a double-stranded RNA-binding protein related to the curvature of folding leaf leading to the formation of leafy head. In order to elucidate the regulatory function of AtLH in the development of leaf curvature, we made a construct of 35S::AtLHand transformed it to Arabidopsis. In transgenic plants for sense-AtLH, transcripts of AtLH gene were increased significantly in leaves and flowers, giving rise to the AtLH-overexpressed plants in which the rosette leaves curved downward or outward in a manner of enhanced epinastic growth. Compared with normal plants, bolting and flowering time of the transgenic plants was significantly delayed. Moreover, the apical dominance of transgenic plants was weaker in vegetative shoots since more axillary shoots emerged from axil of rosette leaves, while stronger in flowering shoots because fewer cauline inflorescences were observed on the main inflorescence. In other aspects, these transgenic plants exhibited an increase in root-stimulating response to IAA and decrease in root-inhibitory reaction on ABA. It indicates that overexpression of AtLH causes downward curvature of transgenic plants.

  3. NUMERICAL STUDY OF THE INFLUENCE OF WAVES AND TIDE-SURGE INTERACTION ON TIDE-SURGES IN THE BOHAI SEA

    Institute of Scientific and Technical Information of China (English)

    尹宝树; 侯一筠; 程明华; 苏京志; 林明祥; 李明悝; M.I.El-Sabh

    2001-01-01

    Abstract The author's combined numerical model consisting of a third generation shallow water wave model and a 3-D tide-surge model with wave-dependent surface wind stress were used to study the influence of waves on fide-surge motion. For the typical weather case, in this study, the magnitude and mechanism of the influence of waves on tide-surges in the Bohai Sea were revealed for the first time. The results showed that although consideration of the wave-dependent surface wind stresses raise slightly the traditional surface wind stress, due to the accumulated effects, the computed results are improved on the whole. Storm level maximum modulation can reach 0.4 m. The results computed by the combined model agreed well with the measured data.

  4. NUMERICAL STUDY OF THE INFLUENCE OF WAVES AND TIDE- SURGE INTERACTION ON TIDE-SURGES IN THE BOHAI SEA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The author's combined numerical model consisting of a third generation shallow water wave model and a 3-D tide-surge model with wave-dependent surface wind stress were used to study the influence of waves on tide-surge motion. For the typical weather case, in this study, the magnitude and mechanism of the influence of waves on tide-surges in the Bohai Sea were revealed for the first time. The results showed that although consideration of the wave-dependent surface wind stresses raise slightly the traditional surface wind stress, due to the accumulated effects, the computed results are improved on the whole. Storm level maximum modulation can reach 0.4 m. The results computed by the combined model agreed well with the measured data.

  5. Mutation Analysis of the LH Receptor Gene in Leydig Cell Adenoma and Hyperplasia and Functional and Biochemical Studies of Activating Mutations of the LH Receptor Gene

    NARCIS (Netherlands)

    Boot, Annemieke M.; Lumbroso, Serge; Verhoef-Post, Miriam; Richter-Unruh, Annette; Looijenga, Leendert H. J.; Funaro, Ada; Beishuizen, Auke; van Marle, Andre; Drop, Stenvert L. S.; Themmen, Axel P. N.

    2011-01-01

    Context: Germline and somatic activating mutations in the LH receptor (LHR) gene have been reported. Objective: Our objective was to perform mutation analysis of the LHR gene of patients with Leydig cell adenoma or hyperplasia. Functional studies were conducted to compare the D578H-LHR mutant with t

  6. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J.F.; Subudhi, M. [Brookhaven National Lab., Upton, NY (United States); Carroll, D.P. [Florida Univ., Gainesville, FL (United States)

    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.

  8. Why Teen Mental Ability Surges While Brain Shrinks

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_166310.html Why Teen Mental Ability Surges While Brain Shrinks Researchers say they may have answer to ... behavior keep scaling up," he said. So while teens lose brain volume and girls have lower brain volume than ...

  9. 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...

  10. 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.

  11. ISSN 2073-9990 East Cent. Afr. J. surg

    African Journals Online (AJOL)

    Hp 630 Dual Core

    COSECSA/ASEA Publication - East and Central African Journal of Surgery. December 2016; Vol. .... shorter duration (median of 20 weeks vs. 3.5 weeks, p 0.029). .... inguinal hernia in children: laparoscopic or open? Eur J Ped Surg 2011; 21: ...

  12. Debris entrainment and landform genesis during tidewater glacier surges

    Science.gov (United States)

    Lovell, Harold; Fleming, Edward J.; Benn, Douglas I.; Hubbard, Bryn; Lukas, Sven; Rea, Brice R.; Noormets, Riko; Flink, Anne E.

    2015-08-01

    The englacial entrainment of basal debris during surges presents an opportunity to investigate processes acting at the glacier bed. The subsequent melt-out of debris-rich englacial structures during the quiescent phase produces geometrical ridge networks on glacier forelands that are diagnostic of surge activity. We investigate the link between debris entrainment and proglacial geomorphology by analyzing basal ice, englacial structures, and ridge networks exposed at the margins of Tunabreen, a tidewater surge-type glacier in Svalbard. The basal ice facies display clear evidence for brittle and ductile tectonic deformation, resulting in overall thickening of the basal ice sequence. The formation of debris-poor dispersed facies ice is the result of strain-induced metamorphism of meteoric ice near the bed. Debris-rich englacial structures display a variety of characteristics and morphologies and are interpreted to represent the incorporation and elevation of subglacial till via the squeezing of till into basal crevasses and hydrofracture exploitation of thrust faults, reoriented crevasse squeezes, and preexisting fractures. These structures are observed to melt-out and form embryonic geometrical ridge networks at the base of a terrestrially grounded ice cliff. Ridge networks are also located at the terrestrial margins of Tunabreen, neighboring Von Postbreen, and in a submarine position within Tempelfjorden. Analysis of network characteristics allows these ridges to be linked to different formational mechanisms of their parent debris-rich englacial structures. This in turn provides an insight into variations in the dominant tectonic stress regimes acting across the glacier during surges.

  13. 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...

  14. A novel role for Lh3 dependent ECM modifications during neural crest cell migration in zebrafish.

    Directory of Open Access Journals (Sweden)

    Santanu Banerjee

    Full Text Available During vertebrate development, trunk neural crest cells delaminate along the entire length of the dorsal neural tube and initially migrate as a non-segmented sheet. As they enter the somites, neural crest cells rearrange into spatially restricted segmental streams. Extracellular matrix components are likely to play critical roles in this transition from a sheet-like to a stream-like mode of migration, yet the extracellular matrix components and their modifying enzymes critical for this transition are largely unknown. Here, we identified the glycosyltransferase Lh3, known to modify extracellular matrix components, and its presumptive substrate Collagen18A1, to provide extrinsic signals critical for neural crest cells to transition from a sheet-like migration behavior to migrating as a segmental stream. Using live cell imaging we show that in lh3 null mutants, neural crest cells fail to transition from a sheet to a stream, and that they consequently enter the somites as multiple streams, or stall shortly after entering the somites. Moreover, we demonstrate that transgenic expression of lh3 in a small subset of somitic cells adjacent to where neural crest cells switch from sheet to stream migration restores segmental neural crest cell migration. Finally, we show that knockdown of the presumptive Lh3 substrate Collagen18A1 recapitulates the neural crest cell migration defects observed in lh3 mutants, consistent with the notion that Lh3 exerts its effect on neural crest cell migration by regulating post-translational modifications of Collagen18A1. Together these data suggest that Lh3-Collagen18A1 dependent ECM modifications regulate the transition of trunk neural crest cells from a non-segmental sheet like migration mode to a segmental stream migration mode.

  15. A novel role for Lh3 dependent ECM modifications during neural crest cell migration in zebrafish.

    Science.gov (United States)

    Banerjee, Santanu; Isaacman-Beck, Jesse; Schneider, Valerie A; Granato, Michael

    2013-01-01

    During vertebrate development, trunk neural crest cells delaminate along the entire length of the dorsal neural tube and initially migrate as a non-segmented sheet. As they enter the somites, neural crest cells rearrange into spatially restricted segmental streams. Extracellular matrix components are likely to play critical roles in this transition from a sheet-like to a stream-like mode of migration, yet the extracellular matrix components and their modifying enzymes critical for this transition are largely unknown. Here, we identified the glycosyltransferase Lh3, known to modify extracellular matrix components, and its presumptive substrate Collagen18A1, to provide extrinsic signals critical for neural crest cells to transition from a sheet-like migration behavior to migrating as a segmental stream. Using live cell imaging we show that in lh3 null mutants, neural crest cells fail to transition from a sheet to a stream, and that they consequently enter the somites as multiple streams, or stall shortly after entering the somites. Moreover, we demonstrate that transgenic expression of lh3 in a small subset of somitic cells adjacent to where neural crest cells switch from sheet to stream migration restores segmental neural crest cell migration. Finally, we show that knockdown of the presumptive Lh3 substrate Collagen18A1 recapitulates the neural crest cell migration defects observed in lh3 mutants, consistent with the notion that Lh3 exerts its effect on neural crest cell migration by regulating post-translational modifications of Collagen18A1. Together these data suggest that Lh3-Collagen18A1 dependent ECM modifications regulate the transition of trunk neural crest cells from a non-segmental sheet like migration mode to a segmental stream migration mode.

  16. Spontaneous and electrochemically stimulated changes in plasma LH in the female rat following hypothalamic deafferentation.

    Science.gov (United States)

    Phelps, C P; Krieg, R J; Sawyer, C H

    1976-01-16

    Plasma LH levels in adult female rats were studied by radioimmunoassay 6 weeks after making frontal cuts (FC) at the optic chiasm with Halász knives of various sizes. Cuts made with a small knife (radius 1.3 mm) permitted a spontaneous rise in plasma LH during proestrus from a mean of 96 +/- 25 ng/ml at 14:00 h to 545 +/- 207 ng/ml at 18:00 h in 13 rats. Seven of the latter, with a mean plasma LH of 967 +/- 281 ng/ml at 18:00 h exhibited tubal ova at hemicastration (hemi-ovx) the following morning. In a similar experiment 6 FC females lesioned with a 1.5 mm knife had plasma LH levels of 53 +/- 7 ng/ml at 14:00 h, but showed neither detectable changes at 2 h intervals through 20:00 h nor ovulation at hemi-ovx. Similar results were obtained in 13 rats deafferented with a 2.0 mm knife. Nine weeks after FC and 3 weeks following hemi-ovx all animals were given pentobarbital (32 mg/kg i.p.) at 13:30 h and stimulated bilaterally in the medial preoptic area (MPO) passing 20 muA anodal DC X 60 sec through concentric bipolar steel electrodes placed 0.8 mm from the midline. All 3 groups of FC animals showed increases in plasma LH to comparable levels (range: 197 +/- 45-357 +/- 156 ng/ml) 1 h after stimulation. Electrochemical stimulation sites extended lateral to the cut locations on at least one side in all animals. The results of these studies suggest that chronically (9 week) deafferented female rats have the capacity to release pituitary LH in response to MPO electrochemical stimulation in spite of retrochiasmatic deafferentation, but that the ovaries of the persistent estrus rat are unresponsive to these amounts of circulating LH.

  17. Fsh and Lh direct conserved and specific pathways during flatfish semicystic spermatogenesis.

    Science.gov (United States)

    Chauvigné, François; Zapater, Cinta; Crespo, Diego; Planas, Josep V; Cerdà, Joan

    2014-10-01

    The current view of the control of spermatogenesis by Fsh and Lh in non-mammalian vertebrates is largely based on studies carried out in teleosts with cystic and cyclic spermatogenesis. Much less is known concerning the specific actions of gonadotropins during semicystic germ cell development, a type of spermatogenesis in which germ cells are released into the tubular lumen where they transform into spermatozoa. In this study, using homologous gonadotropins and a candidate gene approach, for which the genes' testicular cell-type-specific expression was established, we investigated the regulatory effects of Fsh and Lh on gene expression during spermatogenesis in Senegalese sole (Solea senegalensis), a flatfish with asynchronous and semicystic germ cell development. During early spermatogenesis, Fsh and Lh upregulated steroidogenesis-related genes and nuclear steroid receptors, expressed in both somatic and germ cells, through steroid-dependent pathways, although Lh preferentially stimulated the expression of downstream genes involved in androgen and progestin syntheses. In addition, Lh specifically promoted the expression of spermatid-specific genes encoding spermatozoan flagellar proteins through direct interaction with the Lh receptor in these cells. Interestingly, at this spermatogenic stage, Fsh primarily regulated genes encoding Sertoli cell growth factors with potentially antagonistic effects on germ cell proliferation and differentiation through steroid mediation. During late spermatogenesis, fewer genes were regulated by Fsh or Lh, which was associated with a translational and posttranslational downregulation of the Fsh receptor in different testicular compartments. These results reveal that conserved and specialized gonadotropic pathways regulate semicystic spermatogenesis in flatfish, which may spatially adjust cell germ development to maintain a continuous reservoir of spermatids in the testis.

  18. Changing the guard: Polymer replaces porcelain for surge arresters

    Energy Technology Data Exchange (ETDEWEB)

    Skytt, T.; Gleimar, H. E. G.

    2002-07-01

    Surge arresters are safety devices which quickly and effectively limit the over voltages that can arise in transmission networks following lightning, switching and other transient events. The earliest forms of overvoltage protection, a simple air gap between electrodes, have long since been replaced by a new generation of gapless arresters with series-connected, non-linear zinc oxide varistors contained in a porcelain housing. Now these porcelain type surge arresters are being replaced by a new type, called PEXLIM (Polymeric EXcellent LIMiter), which uses the same block of zinc oxide as the porcelain type, but its housing is made of silicon rubber, a polymer. The new lightweight insulation material shows a number of properties superior to the porcelain, such as enhanced product safety and ease of handling. It is also more durable, resilient, yet solid and compact, water-repellent, lightweight, resistant to aging or light or ultra-violet radiation, as well as fire, has good electrical properties, and is environmentally friendly since it does not contain any substances harmful to the environment. These properties make this new type of surge arrester highly suitable for use in earthquake-prone areas; it can also replace more expensive and maintenance-intensive equipment. Having successfully broken into the lower voltage systems, these new type of surge arresters are now rapidly gaining ground at the higher voltage levels. ABB, the developer of PEXLIM, has already supplied these arresters to North America for use in an 800-kV grid. As further proof of its growing popularity, last year PEXLIM made up over half of the surge arrester production for applications up to and including 245 kV. 1 tab., 6 figs.

  19. A basis function approach for exploring the seasonal and spatial features of storm surge events

    Science.gov (United States)

    Wu, Wenyan; Westra, Seth; Leonard, Michael

    2017-07-01

    Storm surge is a significant contributor to flooding in coastal and estuarine regions. To represent the statistical characteristics of storm surge over a climatologically diverse region, we propose the use of basis functions that capture the temporal progression of individual storm surge events. This extends statistical analyses of surge from considering only the peak to a more multifaceted approach that also includes decay rate and duration. Our results show that there is seasonal variation in storm surge along the Australian coastline. During the dominant storm surge seasons, the peak and duration of storm surge events tend to increase simultaneously at a number of locations, with implications for flood damage assessments and evacuation planning. By combining the dynamic and statistical features of storm surge, it is possible to better understand the factors that can lead to flood risk along the coastline, including estuarine areas that are also affected by fluvial floods.

  20. 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.

    India and its neighbourhood is threatened by the possibility of storm surge floods whenever a tropical cyclone approaches. Storm surge disasters cause heavy loss of life and property, damage to the coastal structures and agriculture nwhich lead...

  1. Effect of Coupling Wave and Flow Dynamics on Hurricane Surge and Inundation

    Science.gov (United States)

    2012-01-01

    impacted hurricanes - both by the wind fields as well as by the accompanying surge. Forecasting the extent of the inundation is critical for local...estimate local surge hazards; and in the other, ensemble model runs are used to determine surge values from a set of parameterized storms [Irish et...with the storm surge to create the storm tide. The extent of coastal inundation - flooding of inland surface that is not normally submerged, is

  2. Brief Communication: On the magnitude and frequency of Khurdopin glacier surge events

    OpenAIRE

    D. J. Quincey; Luckman, A.

    2014-01-01

    The return periods of Karakoram glacier surges are poorly quantified. Here, we present evidence of an historic surge of the Khurdopin Glacier that began in the mid-1970s and peaked in 1979. Measured surface displacements reached >5 km a−1, two orders of magnitude faster than during quiescence. The Khurdopin Glacier next surged in the late 1990s, equating to a return period of 20 years. Surge evolution in the two events shows remarkable similarity suggesting a common trigger....

  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. Single-molecule spectroscopy on RC-LH1 complexes of Rhodopseudomonas acidophila strain 10050.

    Science.gov (United States)

    Böhm, Paul S; Southall, June; Cogdell, Richard J; Köhler, Jürgen

    2013-03-21

    We have revisited the RC-LH1 complex from Rhodopseudomonas (Rps.) acidophila for single-molecule spectroscopy. For the current study the pigment-protein complexes were stabilized in the detergent buffer solution using a relatively mild detergent (dodecyl-β-D-maltoside (DDM) instead of lauryldimethylamine N-oxide (LDAO)). This leads to a significant reduction of the fraction of broken/dissociated RC-LH1 complexes with respect to previous studies and has allowed us to investigate a sufficiently large sample of individual RC-LH1 complexes. For most of the complexes the fluorescence-excitation spectra exhibit a narrow spectral feature at the red end of the spectrum. Analysis of the statistics of the spectral properties yields a close resemblance with the results obtained on RC-LH1 complexes from Rps. palustris for which a low-resolution X-ray structure is available. Based on this comparison we come to the conclusion that for both species the RC-LH1 complex can be described by the same structural model, that is, an overall elliptical assembly of pigments that features a gap.

  5. Physics of GAM-initiated L-H transition in a tokamak

    Science.gov (United States)

    Askinazi, L. G.; Belokurov, A. A.; Bulanin, V. V.; Gurchenko, A. D.; Gusakov, E. Z.; Kiviniemi, T. P.; Lebedev, S. V.; Kornev, V. A.; Korpilo, T.; Krikunov, S. V.; Leerink, S.; Machielsen, M.; Niskala, P.; Petrov, A. V.; Tukachinsky, A. S.; Yashin, A. Yu; Zhubr, N. A.

    2017-01-01

    Based on experimental observations using the TUMAN-3M and FT-2 tokamaks, and the results of gyrokinetic modeling of the interplay between turbulence and the geodesic acoustic mode (GAM) in these installations, a simple model is proposed for the analysis of the conditions required for L-H transition triggering by a burst of radial electric field oscillations in a tokamak. In the framework of this model, one-dimensional density evolution is considered to be governed by an anomalous diffusion coefficient dependent on radial electric field shear. The radial electric field is taken as the sum of the oscillating term and the quasi-stationary one determined by density and ion temperature gradients through a neoclassical formula. If the oscillating field parameters (amplitude, frequency, etc) are properly adjusted, a transport barrier forms at the plasma periphery and sustains after the oscillations are switched off, manifesting a transition into the high confinement mode with a strong inhomogeneous radial electric field and suppressed transport at the plasma edge. The electric field oscillation parameters required for L-H transition triggering are compared with the GAM parameters observed at the TUMAN-3M (in the discharges with ohmic L-H transition) and FT-2 tokamaks (where no clear L-H transition was observed). It is concluded based on this comparison that the GAM may act as a trigger for the L-H transition, provided that certain conditions for GAM oscillation and tokamak discharge are met.

  6. FSH inhibits the augmentation by oestradiol of the pituitary responsiveness to GnRH in the female rat

    NARCIS (Netherlands)

    Schuiling, GA; Valkhof, N; Koiter, TR

    1999-01-01

    The effect of follicle stimulating hormone (FSH) treatment on the pituitary response to gonadotrophin-releasing hormone (GnRH) was studied in rats in various reproductive conditions. A 3-day treatment of cycling rats with FSH (Metrodin(R); 10 IU/injection) lowered the spontaneous pre-ovulatory LH-su

  7. Intermittent suckling enables estrus and pregnancy during lactation in sows: Effects of stage of lactation and lactation during early pregnancy

    NARCIS (Netherlands)

    Gerritsen, R.; Soede, N.M.; Hazeleger, W.; Langendijk, P.; Dieleman, S.J.; Taverne, M.A.M.; Kemp, B.

    2009-01-01

    Previously we demonstrated that pre-ovulatory LH and post-ovulatory progesterone (P4) concentrations in plasma were low and embryo development was retarded when sows were induced to ovulate during lactation by submitting them to intermittent suckling (IS). The present study investigated whether this

  8. 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,...

  9. 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...

  10. THE STUDY OF ALLOCATION OF SURGE BUNKER IN MINE HAULAGE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    王喜富; 张幼蒂; 张达贤

    1997-01-01

    Based on the function analysis of surge bunker in mine haulage system, the authors raise the calculation methods of the total output of a mine haulage system. Taking the maximum of system's total throughput as a objective, the method of determining the surge bunker's rational size is put forward. Also, the problems of rational position of surge bunker are analysesed.

  11. A model study of Abrahamsenbreen, a surging glacier in northern Spitsbergen

    NARCIS (Netherlands)

    Oerlemans, J.; van Pelt, W. J. J.

    2015-01-01

    The climate sensitivity of Abrahamsenbreen, a 20 km long surge-type glacier in northern Spitsbergen, is studied with a simple glacier model. A scheme to describe the surges is included, which makes it possible to account for the effect of surges on the total mass budget of the glacier. A climate rec

  12. GnRH-induced Ca2+ signaling patterns and gonadotropin secretion in pituitary gonadotrophs. Functional adaptations to both ordinary and extraordinary physiological demands

    Directory of Open Access Journals (Sweden)

    María Luisa eDurán-Pastén

    2013-09-01

    Full Text Available Pituitary gonadotrophs are a small fraction of the anterior pituitary population, yet they synthesize gonadotropins: luteinizing (LH and follicle stimulating (FSH, essential for gametogenesis and steroidogenesis. LH is secreted via a regulated pathway while FSH release is mostly constitutive and controlled by synthesis. Although gonadotrophs fire action potentials spontaneously, the intracellular Ca2+ rises produced do not influence secretion, which is mainly driven by Gonadotropin Releasing Hormone (GnRH, a decapeptide synthesized in the hypothalamus and released in a pulsatile manner into the hypophyseal portal circulation. GnRH binding to G protein coupled receptors triggers Ca2+ mobilization from InsP3-sensitive intracellular pools, generating the global Ca2+ elevations necessary for secretion. Ca2+ signaling responses to increasing [GnRH] vary in stereotyped fashion from subthreshold to baseline spiking (oscillatory, to biphasic (spike-oscillatory or spike-plateau. This progression varies somewhat in gonadotrophs from different species and biological preparations. Both baseline spiking and biphasic GnRH-induced Ca2+ signals control LH/FSH synthesis and exocytosis. Estradiol and testosterone regulate gonadotropin secretion through feedback mechanisms, while FSH synthesis and release are influenced by activin, inhibin and follistatin. Adaptation to physiological events like the estrous cycle, involves changes in GnRH sensitivity and LH/FSH synthesis: in proestrus, estradiol feedback regulation abruptly changes from negative to positive, causing the pre-ovulatory LH surge. Similarly, when testosterone levels drop after orquiectomy the lack of negative feedback on pituitary and hypothalamus boosts both GnRH and LH secretion, gonadotrophs GnRH sensitivity increases and Ca2+ signaling patterns change. In addition, gonadotrophs proliferate and grow. These plastic changes denote a more vigorous functional adaptation in response to an extraordinary

  13. 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 pregnancy outcome. Progesterone concentration was measured on stimulation day 1 and on the day of HCG administration in 475 patients who underwent IVF/intracytoplasmic sperm injection treatment following ovarian stimulation with gonadotrophin-releasing hormone (GnRH) agonist and recombinant FSH...... 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...

  14. Building and Analyzing SURGEDAT: The World's Most Comprehensive Storm Surge Database

    Science.gov (United States)

    Needham, H.; Keim, B.

    2012-12-01

    SURGEDAT, the world's most comprehensive tropical storm surge database, has identified and mapped the location and height of hundreds of global storm surge events. This project originated with a study that identified more than 200 tropical surge events along the U.S. Gulf Coast. Spatial analysis of these data reveal that the central and western Gulf Coast observe more frequent and higher magnitude surges, whereas much of the eastern Gulf Coast, including the west coast of Florida, experiences less storm surge activity. Basin-wide return period analysis of these data estimate a 100-year return period of 8.20m, and a 10-year return period of 4.95m. Return period analysis of 10 sub-regions within the basin reveal that the highest surge levels occur in the Southeast Louisiana/ Mississippi zone, which includes the New Orleans metropolitan area. The 100-year surge level in this zone is estimated to be 7.67m. The Southeast Texas/ Southwest Louisiana zone, which includes the Houston metropolitan area, has the second highest surge levels, with a 100-year storm surge estimate of 6.30m. Surge levels are lower on the west coast of Florida, where the 100-year surge level is estimated between three and four meters. Expansion of this work includes mapping all high water marks for each surge event and the creation of a search-by-location web tool, which enables users to see the entire storm surge history for specific locations. In addition, the dataset has expanded internationally and now includes more than 500 surge events, as surges have now been identified in all the major ocean basins that experience tropical cyclones. International partnerships are sought to further expand this work, particularly in Australia, China, Japan, Philippines, India, Bangladesh, Myanmar, Mexico and various countries in Oceania and the Caribbean.; ;

  15. Waves of accelerated motion in a glacier approaching surge: the mini-surges of Variegated Glacier, Alaska, U.S.A.

    OpenAIRE

    Kamb, Barclay; Engelhardt, Hermann

    1987-01-01

    Periods of dramatically accelerated motion, in which the flow velocity increases suddenly from about 55 cm/d to a peak of 100-300 cm/d and then decreases gradually over the course of a day, occurred repeatedly during June and July 1978-81 in Variegated Glacier (Alaska), a surging-type glacier that surged in 1982-83. These "mini-surges" appear to be related mechanistically to the main surge. The flow-velocity peak propagates down-glacier as a wave at a speed of about 0.3 km/h, over a reach of ...

  16. Veränderungen kognitiver Funktionen unter LH-RH-Therapie bzw. unter Bicalutamid-Monotherapie

    Directory of Open Access Journals (Sweden)

    Brössner C

    2009-01-01

    Full Text Available Einleitung: Androgendeprivationstherapie mit LH-RH-Agonisten bzw. Androgenrezeptorblockade mit Bicalutamid wurde zur Standardtherapie beim fortgeschrittenen Prostatakarzinom. Der Großteil der existierenden Literatur beschreibt unter LH-RH-Gabe und damit verbundener Senkung des Testosteronspiegels eine Verschlechterung bestimmter kognitiver Gedächtnisleistungen. Ziel unserer prospektiven, konsekutiven Studie ist es, kognitive und emotionale Funktionen sowie die Lebensqualität bei Männern unter LH-RH bzw. unter Bicalutamid-Monotherapie zu untersuchen. Methoden: In Gruppe A wurden 15 Männer (mean 70,5 a; 57–81 inkludiert, die ein LH-RHAnalogon für 1 Jahr erhielten. In Gruppe B wurden 12 Männer (mean 69,3 a; 56–80 unter Bicalutamid-Monotherapie (150 mg/d für 1 Jahr inkludiert. Zum Zeitpunkt der kognitiven Testung waren alle Patienten frei von klinischer Metastasierung und die PSA-Werte waren 0,5 ng/ml. Für die Untersuchung der kognitiven Leistungen wurde eine umfangreiche neuropsychologische alters-, geschlechts- und bildungskorrigierte Testbatterie eingesetzt: Tests für Aufmerksamkeit (ZVT, Stroop-Test, Gedächtnis (NAI, WMS-R, Demenz (MMSE, Lebensqualität (WHOQOL-BREF, Wahrnehmung (Mosaik-Test, Sprache (LPS 50 Depression (BDI sowie für Angst (STAI wurden durchgeführt. Ergebnisse: In Gruppe A (unter LH-RH fanden wir signifikante Defizite im topografischen (T = 39,3 und visuellen Langzeitgedächtnis (T = 35,6. Das visuelle und verbale Arbeitsgedächtnis zeigte in dieser Gruppe grenzwertige Defizite (T = 40,67 und T = 41,67. In Gruppe B (Bicalutamid konnten wir dagegen bei keinem der Patienten ein kognitives Defizit feststellen. Schlussfolgerung: Unsere Daten suggerieren einen signifikanten negativen Einfluss der LH-RHLangzeittherapie auf bestimmte kognitive Funktionen. Im Gegensatz dazu fanden wir keine Veränderungen unter Bicalutamid-Monotherapie.

  17. Analysis on Lightning Surge Propagation in Wind Farm

    Science.gov (United States)

    Yasuda, Yoh; Hara, Takehisa; Funabashi, Toshihisa

    Wind power generation is expected to become more important in the future distribution system. Although several prospective reports such as IEC 61400-24 and NREL SR-500-31115 indicate on insulation scheme and grounding design for lightning protection, it still seems that there are not many investigations on the problems. This paper therefore discusses lightning surge analysis using wind farm model with 2 or 10 ideal wind turbines. Changing parameters such as grounding resistance and lightning strike points, several cases were studied. As the result of the analysis using digital simulator ARENE, it is clear that the surge tends to propagate toward the end of a distribution line in a wind farm and there is possibility of insulation accidents at the other wind turbines when lightning attacks a wind turbine.

  18. RESEARCH ON THE CONDITION TO SET A TAILRACE SURGE TANK

    Institute of Scientific and Technical Information of China (English)

    ZHAO Gui-lian; YANG jian-dong; XU Yuan-jie; LI Jin-ping

    2004-01-01

    When using the draft-tube vacuum to be less than 8.0m as the rule to set a tailrace surge tank, a mixing function that describes the process of water-hammer vacuum and velocity-head vacuum varied with time is proposed, on the assumption that the guide vane of the hydraulic turbine and the turbine discharge were all changed linearly. An exact maximum of the draft-tube vacuum for the first-phase water-hammer and the last-phase water-hammer is obtained. Finally a much more reasonable formula of critical tailrace length is derived. The results of two cases show that the formula proposed can determine correctly and reasonably whether a tailrace surge tank is needed or not, and are more suitable for project design than the formula suggested by the specification.

  19. Dynamic stall on a pitching and surging airfoil

    Science.gov (United States)

    Dunne, Reeve; McKeon, Beverley J.

    2015-08-01

    Vertical axis wind turbine blades undergo dynamic stall due to the large angle of attack variation they experience during a turbine rotation. The flow over a single blade was modeled using a sinusoidally pitching and surging airfoil in a non-rotating frame with a constant freestream flow at a mean chord Reynolds number of . Two-dimensional, time-resolved velocity fields were acquired using particle image velocimetry. Vorticity contours were used to visualize shear layer and vortex activity. A low-order model of dynamic stall was developed using dynamic mode decomposition, from which primary and secondary dynamic separation modes were identified. The interaction between these two modes was able to capture the physics of dynamic stall and as such can be extended to other turbine configurations and problems in unsteady aerodynamics. Results from the linear pitch/surge frame are extrapolated to the rotating VAWT frame to investigate the behavior of identified flow structures.

  20. 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

  1. Rapid Response Measurements of Hurricane Waves and Storm Surge

    Science.gov (United States)

    Gravois, U.

    2010-12-01

    Andrew (1992), Katrina (2005), and Ike (2008) are recent examples of extensive damage that resulted from direct hurricane landfall. Some of the worst damages from these hurricanes are caused by wind driven waves and storm surge flooding. The potential for more hurricane disasters like these continues to increase as a result of population growth and real estate development in low elevation coastal regions. Observational measurements of hurricane waves and storm surge play an important role in future mitigation efforts, yet permanent wave buoy moorings and tide stations are more sparse than desired. This research has developed a rapid response method using helicopters to install temporary wave and surge gauges ahead of hurricane landfall. These temporary installations, with target depths from 10-15 m and 1-7 km offshore depending on the local shelf slope, increase the density of measurement points where the worst conditions are expected. The method has progressed to an operational state and has successfully responded to storms Ernesto (2006), Noel (2007), Fay (2008), Gustav (2008), Hanna (2008) and Ike (2008). The temporary gauges are pressure data loggers that measure at 1 Hz continuously for 12 days and are post-processed to extract surge and wave information. For the six storms studied, 45 out of 49 sensors were recovered by boat led scuba diver search teams, with 43 providing useful data for an 88 percent success rate. As part of the 20 sensor Hurricane Gustav response, sensors were also deployed in lakes and bays inLouisiana, east of the Mississippi river delta. Gustav was the largest deployment to date. Generally efforts were scaled back for storms that were not anticipated to be highly destructive. For example, the cumulative total of sensors deployed for Ernesto, Noel, Fay and Hanna was only 20. Measurement locations for Gustav spanned over 800 km of exposed coastline from Louisiana to Florida with sensors in close proximity to landfall near Cocodrie

  2. Source of a Prominent Poleward Surge During Solar Cycle 24

    CERN Document Server

    Yeates, A R; van Driel-Gesztelyi, L

    2015-01-01

    As an observational case study, we consider the origin of a prominent poleward surge of leading polarity, visible in the magnetic butterfly diagram during Solar Cycle 24. A new technique is developed for assimilating individual regions of strong magnetic flux into a surface flux transport model. By isolating the contribution of each of these regions, the model shows the surge to originate primarily in a single high-latitude activity group consisting of a bipolar active region present in Carrington Rotations 2104-05 (November 2010-January 2011) and a multipolar active region in Rotations 2107-08 (February-April 2011). This group had a strong axial dipole moment opposed to Joy's law. On the other hand, the modelling suggests that the transient influence of this group on the butterfly diagram will not be matched by a large long-term contribution to the polar field, because of its location at high latitude. This is in accordance with previous flux transport models.

  3. Hindbrain lactate regulates preoptic gonadotropin-releasing hormone (GnRH) neuron GnRH-I protein but not AMPK responses to hypoglycemia in the steroid-primed ovariectomized female rat.

    Science.gov (United States)

    Shrestha, P K; Briski, K P

    2015-07-09

    Steroid positive-feedback activation of the gonadotropin-releasing hormone (GnRH)-pituitary luteinizing hormone (LH) neuroendocrine axis propagates the pre ovulatory LH surge, a crucial component of female reproduction. Our work shows that this key event is restrained by inhibitory metabolic input from hindbrain A2 noradrenergic neurons. GnRH neurons express the ultra-sensitive energy sensor adenosine 5'-monophosphate-activated protein kinase (AMPK); here, we investigated the hypothesis that GnRH nerve cell AMPK and peptide neurotransmitter responses to insulin-induced hypoglycemia are controlled by hindbrain lack of the oxidizable glycolytic end-product L-lactate. Data show that hypoglycemic inhibition of LH release in steroid-primed ovariectomized female rats was reversed by coincident caudal hindbrain lactate infusion. Western blot analyses of laser-microdissected A2 neurons demonstrate hypoglycemic augmentation [Fos, estrogen receptor-beta (ER-β), phosphoAMPK (pAMPK)] and inhibition (dopamine-beta-hydroxylase, GLUT3, MCT2) of protein expression in these cells, responses that were normalized by insulin plus lactate treatment. Hypoglycemia diminished rostral preoptic GnRH nerve cell GnRH-I protein and pAMPK content; the former, but not the latter response was reversed by lactate. Results implicate caudal hindbrain lactoprivic signaling in hypoglycemia-induced suppression of the LH surge, demonstrating that lactate repletion of that site reverses decrements in A2 catecholamine biosynthetic enzyme and GnRH neuropeptide precursor protein expression. Lack of effect of lactate on hypoglycemic patterns of GnRH AMPK activity suggests that this sensor is uninvolved in metabolic-inhibition of positive-feedback-stimulated hypophysiotropic signaling to pituitary gonadotropes.

  4. 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 pregnancy outcome. Progesterone concentration was measured on stimulation day 1 and on the day of HCG administration in 475 patients who underwent IVF/intracytoplasmic sperm injection treatment following ovarian stimulation with gonadotrophin-releasing hormone (GnRH) agonist and recombinant FSH...

  5. Controlling near shore nonlinear surging waves through bottom boundary conditions

    CERN Document Server

    Mukherjee, Abhik; Kundu, Anjan

    2016-01-01

    Instead of taking the usual passive view for warning of near shore surging waves including extreme waves like tsunamis, we aim to study the possibility of intervening and controlling nonlinear surface waves through the feedback boundary effect at the bottom. It has been shown through analytic result that the controlled leakage at the bottom may regulate the surface solitary wave amplitude opposing the hazardous variable depth effect. The theoretical results are applied to a real coastal bathymetry in India.

  6. Wildlife Poaching: Africa’s Surging Trafficking Threat

    Science.gov (United States)

    2014-05-01

    called keratin, an inert substance that is similar in composition to human fingernails and hair. Some of the consequences of wildlife trafficking are...of the few central figures to have been convicted is a Thai trafficker named Chumlong Lem- tongthai, who worked for businesses in Thailand and Laos...4 1 Wildlife Poaching: Africa’s Surging Trafficking Threat By Bradley anderson and Johan Jooste u Spikes in the prices of ivory and rhino horn have

  7. Enkephalin surges in dorsal neostriatum as a signal to eat

    OpenAIRE

    DiFeliceantonio, Alexandra G.; Mabrouk, Omar S.; Kennedy, Robert T.; C. Berridge, Kent

    2012-01-01

    Compulsive over-consumption of rewards characterizes disorders ranging from binge eating to drug addiction. Here, we provide evidence that enkephalin surges in an anteromedial quadrant of dorsal neostriatum contribute to generating intense consumption of palatable food. In ventral striatum, mu opioid circuitry contributes an important component of motivation to consume rewards [1–4]. In dorsal neostriatum, mu opioid receptors are concentrated within striosomes that receive inputs from limbic ...

  8. Population vulnerability to storm surge flooding in coastal Virginia, USA.

    Science.gov (United States)

    Liu, Hua; Behr, Joshua G; Diaz, Rafael

    2016-07-01

    This study aims to assess the vulnerability of populations to storm surge flooding in 12 coastal localities of Virginia, USA. Population vulnerability is assessed by way of 3 physical factors (elevation, slope, and storm surge category), 3 built-up components (road availability, access to hospitals, and access to shelters), and 3 household conditions (storm preparedness, financial constraints to recovering from severe weather events, and health fragility). Fuzzy analysis is used to generate maps illustrating variation in several types of population vulnerability across the region. When considering physical factors and household conditions, the most vulnerable neighborhoods to sea level rise and storm surge flooding are largely found in urban areas. However, when considering access to critical infrastructure, we find rural residents to be more vulnerable than nonrural residents. These detailed assessments can inform both local and state governments in catastrophic planning. In addition, the methodology may be generalized to assess vulnerability in other coastal corridors and communities. The originality is highlighted by evaluating socioeconomic conditions at refined scale, incorporating a broader range of human perceptions and predispositions, and employing a geoinformatics approach combining physical, built-up, and socioeconomic conditions for population vulnerability assessment. Integr Environ Assess Manag 2016;12:500-509. © 2015 SETAC. © 2015 SETAC.

  9. Mass balance, runoff and surges of Bering Glacier, Alaska

    Directory of Open Access Journals (Sweden)

    W. Tangborn

    2013-05-01

    Full Text Available The historical net, ablation and accumulation daily balances, as well as runoff of Bering Glacier, Alaska are determined for the 1951–2011 period with the PTAA (precipitation-temperature-area-altitude model, using daily precipitation and temperature observations collected at the Cordova and Yakutat weather stations, together with the area-altitude distribution of the glacier. The model mean annual balance for this 61 yr period is −0.6 m w.e., the accumulation balance is +1.4 and the ablation balance is −2.0 m w.e. Average annual runoff is 2.5 m w.e. Periodic surges of this glacier transport large volumes of ice to lower elevations where the ablation rate is higher, producing more negative balances and increasing runoff. Runoff from Bering Glacier (derived from simulated ablation and precipitation as rain is highly correlated with four of the glacier surges that have occurred since 1951. Ice volume loss for the 1972–2003 period measured with the PTAA model is 2.7 km3 w.e. a−1 and closely agrees with losses for the same period measured with the geodetic method. It is proposed that the timing and magnitude of daily snow accumulation and runoff, both of which are controlled by the glacier's area-altitude distribution and are calculated with the PTAA model, can be used to determine the probability that a glacier will surge.

  10. New insights in the ongoing surge of the Austfonna icecap

    Science.gov (United States)

    Schellenberger, T.; Dunse, T.; Kääb, A.; Hagen, J. O.; Schuler, T.; Reijmer, C.

    2014-12-01

    Basin-3, a major drainage basin of the Austfonna icecap in NE-Svalbard switched to full surge mode in autumn 2012 after a multiannual, stepwise acceleration of its northern branch. A time series of velocity maps from repeat TerraSAR-X acquisitions revealed a maximum speed at the terminus of >18 m d-1 around the turn of the year 2012. The frontal ablation of Basin-3 was estimated to 4.2±1.6 Gt a-1 between April 2012 and May 2013, tripling the total dynamic mass loss from the largest icecap in the Eurasian arctic. Today, TerraSAR-X, Radarsat-2 and GPS data show that the surge is still ongoing. While the speed at the calving front dropped to 10 m d-1 until July 2014, areas further inland continued to accelerate after the climax, and 10 m d-1 were also measured ~20 km inland in summer 2014. This development will be further investigated by exploiting a time series of velocity maps based on Radarsat-2 Fine Beam data starting from July 2014, which will, other than the TerraSAR-X data, cover almost the entire fast flowing part of the basin. By combining both datasets we will extend the estimation of the frontal ablation and related sea-level rise contribution of the Basin-3 surge.

  11. 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.

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

    Science.gov (United States)

    Andersen, O. B.; Cheng, Y.; Deng, X.; Steward, M.; Gharineiat, Z.

    2015-03-01

    The combination of the coarse temporal sampling by satellite altimeters in the deep ocean with the high temporal sampling at sparsely located tide gauges along the coast has been used to improve the forecast of high water for the North Sea along the Danish Coast and for the northeast coast 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 selected several representative high water events on the two continents based on tide gauge recordings and investigated the capability of satellite altimetry to capture these events in the sea surface height data. Due to the lack of recent surges in the North Sea we focused on general high water level and found that in the presence of two or more satellites we could capture more than 90% of the high water sea level events. In the Great Barrier Reef section of the northeast Australian coast, we have investigated several large tropical cyclones; one of these being Cyclone Larry, which hit the Queensland coast in March 2006 and caused both loss of lives as well as huge devastation. Here we demonstrate the importance of integrating tide gauges with satellite altimetry for forecasting high water at the city of Townsville in northeast Australia.

  13. Surge dynamics in the Nathorstbreen glacier system, Svalbard

    Directory of Open Access Journals (Sweden)

    M. Sund

    2013-10-01

    Full Text Available Nathorstbreen glacier system (NGS recently experienced the largest surge in Svalbard since 1936, and is examined using spatial and temporal observations from DEM differencing, time-series of surface velocities from satellite synthetic aperture radar (SAR and other sources. The upper basins with maximum accumulation during quiescence correspond to regions of initial lowering. Initial speed-up exceeds quiescent velocities by a factor of several tens of times. This suggests that polythermal glaciers surges are initiated in the temperate area before mass is displaced downglacier. Subsequent downglacier mass displacement coincides with areas of 100–200 times increased velocities (stage 2. After > 5 yr the joint NGS terminus advanced abruptly into tidewater during winter. The advance was followed by upglacier propagation of crevasses, indicating a re-action following from the already displaced mass and extending flow. NGS advanced ca. 15 km, while another ca. 3 km length was lost due to calving. Surface lowering of ca. 50 m was observed in some upglacier areas and during 5 yr the total area increased by 20%. Maximum measured flow rates were at least 25 m d−1, 2500 times quiescence, while average velocities were about 10 m d−1. The surges of Zawadzkibreen cycle with ca. 70 yr periods.

  14. Mass balance, runoff and surges of the Bering Glacier, Alaska

    Directory of Open Access Journals (Sweden)

    W. Tangborn

    2012-12-01

    Full Text Available The historical net, ablation and accumulation daily balances and runoff of the Bering Glacier, Alaska are determined for the 1951–2011 period with the PTAA (precipitation-temperature-area-altitude model, using daily precipitation and temperature observations collected at the Cordova and Yakutat weather stations, together with the area-altitude distribution of the glacier. The mean annual balance for this 61-yr period is −0.6 mwe, the accumulation balance is +1.4 and the ablation balance is −2.0 mwe. Periodic surges of this glacier transport large volumes of ice to lower elevations where the ablation rate is higher, producing more negative balances and increasing runoff. During the 1993–1995 surge the average ablation balance is −3.3 mwe, over a meter greater than the 1951–2011 average. Runoff from the Bering Glacier (derived from simulated ablation and precipitation as rain is highly correlated with the four glacier surges that have been observed since 1951. Ice volume loss for the 1972–2003 period measured with the PTAA model is 2.3 km3 we a−1 and closely agrees with losses for the same period measured with the geodetic method.

  15. H{α} Surges Aroused by Newly-emerging Satellite Bipolar Magnetic Field

    Science.gov (United States)

    Wang, J. F.; Zhou, T. H.; Ji, H. S.

    2013-07-01

    An Hα surge event occurred at AR NOAA 11259 on 2011 July 22. According to the BBSO (Big Bear Solar Observatory) Hα line-center observations, three surges continuously ejected from the same region to the north of the main-sunspot of AR 11259. All of surges ejected along a straight trajectory, and looked like the reversed Eiffel Tower. The first and second surges had the same process. Two bright points firstly appeared to the north of the main-sunspot. After several minutes, a surge appeared between the two bright points, and then rapidly ejected when the two points got most brightness.When the surge reached the maximum height, it disappeared quickly. However, the third surge appeared without bright points, and its height was only half of the others. Compared with SDO/HMI (Solar Dynamics Observatory/Helioseismic and Magnetic Imager) line-of-sight magnetogram, more than one hour before the first surge appeared, a satellite bipolar magnetic field emerged from the surge-ejection region. The newly-emerging positive magnetic flux showed a distinct decrease several minutes earlier than the ejection of the surges. We assumed that the surges was associated with the reconnection between the newly-emerging bipolar magnetic field and the existing (sunspot) magnetic field.

  16. Field assessment of surge and continuous furrow irrigation methods in relation to tillage systems

    Science.gov (United States)

    Mattar, Mohamed A.; El-Saadawy, Mohamed A.; Helmy, Mamdouh A.; Sorour, Hussien M.

    2017-04-01

    Surge flow irrigation is one of the irrigation techniques for controlling furrow irrigation. The aim of this study was to investigate the effect of surge furrow irrigation on water management compared with continuous irrigation for different tillage systems. An experimental field was treated with various tillage systems (mouldboard plough, chisel plough and rotary plough) and water irrigation application methods (continuous flow, control) in which irrigation water was applied continuously, and surge flow (3-surges, 4-surges and 5-surges) in which irrigation water was applied intermittently until it reached the tail end of the furrow. The results showed that water savings obtained using the surge technique were 18.58, 11.84 and 18.93% lower water use than with continuous flow, for the mouldboard, chisel and rotary ploughs, respectively. The 3-surges treatment with the rotary plough reduced the advance time by 25.36% from that for continuous irrigation. The 4-surges treatment with the mouldboard plough had the highest water application efficiency (88.13%). The 3-surges treatment with the rotary plough had the highest distribution uniformity (85.01%). The rotary plough did not cause as much soil aeration around the root system as the other tillage systems. The field research provided information about surge flow, aimed at reducing advance times and increasing irrigation efficiency.

  17. Can we use crevasse fill ridges for identifying undocumented surge behavior in Svalbard?

    Science.gov (United States)

    Farnsworth, W. R.; Ingolfsson, O.; Schomacker, A.; Retelle, M.

    2015-12-01

    Documenting glaciers that exhibit surge type behavior is crucial, especially as we attempt to use evidence of ice front fluctuations for reconstructing past climate oscillations. Controversy exists regarding the relationship between surge activity and climatic processes such as mass balance. This project identifies undocumented surge type glaciers in Svalbard based on the presence of crevasse fill ridges (CFRs) visible in glacier forelands. Although it is acknowledged that many Svalbard outlet glaciers surge, estimates vary greatly as to the actual number of surge- type glaciers in Svalbard, and their distribution pattern is not well understood. A detailed survey of recent (2008-2011), high resolution imagery from Toposvalbard, provided by the Norwegian Polar Institute, allowed for a rapid analysis of Svalbard outlet glaciers. Using CFRs as indicators of surge behavior has almost doubled the amount of potential surge-type glaciers in central Spitsbergen. This method also highlights numerous other glaciers of potential surge type behavior throughout the archipelago. Limits to the CFR identification method are discussed. Additionally as the forelands of previously reported surge type glaciers were analyzed for CFRs, it was evident that the surge indicators were only present in approximately half of the forelands. Numerous factors control the formation and preservation of CFRs including; glacier size, bedrock lithology, subglacial sediments and clast size as well as glacial fluvial run-off. This poster focuses on the controlling factors for CFR formation and preservation as well as other potential methods for effectively identifying surge behavior.

  18. Evaluation on performance of Beckman Coulter LH-750 hematocyte analyzer%Beckman Coulter LH-750血细胞分析仪性能评价

    Institute of Scientific and Technical Information of China (English)

    张伟; 木合布力·艾沙

    2011-01-01

    目的 系统评价LH-750全自动血细胞分析仪的性能.方法 选用定值质控全血连续重复测定,选取白细胞、红细胞、血小板计数、血小板压积和血红蛋白5个主要参数以评价仪器的精密度、准确度和不确定度;高、低值样品连续重复3次评价仪器的携带污染率;将全血按比例稀释并进行检测,作线性范围的评价;以两种不同的进样模式测定标本,计算偏倚率;同一份标本分别用LH-750和Sysmex1000i同时检测,观察两者之间的相关性.结果 质控物测定结果CV≤2.96%,携带污染率小于或等于0.56%,LH-750线性较好,与Sysmex1000i测定的结果比较,相关性良好(r≥0.996 6).结论 LH-750型血细胞分析仪的准确性、精密度均良好,携带污染率低且线性较好,与sysmex1000i具有良好的一致性,能满足血液分析的一般要求.%Objective To evaluate the performance of Beckman Coulter LH 750 automated hematology analyzer. Methods Rating quality control whole blood was successively and repetitively to evaluate the accuracy, precision and uncertainty which obey to the standard of ICSH and NCCLS; high and low value serum specimens were determined for successive 3 times to investigate the carry over rate. Dilute the blood by the same proportion to measure line range; Detect the samples with two different sampling modes and compared. Detect the sample with LH 750 and sysmexl000i hematology analyzer respectively and compared. Results The result of quality control specimen showed CV was below 2.96 % , and the carry over rate was below 0.6 %. The result correlated well with those obtained on Sysmexl000i(r>0. 996 ). Conclusion Beckman Coulter LH 750 hematocyte analyzer possess high precision and accuracy,low carry over rate, excellent line range,and closely correlative to sysmexl000i and achieves the clinical demand for hematological analysis.

  19. Regulation of luteinizing hormone (LH) subunit biosynthesis in cultured male anterior pituitary cells: effects of GnRH and testosterone

    Energy Technology Data Exchange (ETDEWEB)

    Krummen, L.A.

    1988-01-01

    The purpose of this study was to evaluate the direct effects of testosterone (T) on LH subunit apoprotein synthesis, glycosylation and release by the male pituitary. Cells from 1 wk castrate rats were cultured for 48 h in steroid-free medium followed by 48h in media /+-/10nM T. The cells were then incubated for 2, 4, 6, 8, or 12h in media containing (/sup 35/S)-methionine (/sup 35/S-Met) or (/sup 3/H)-glucosamine (/sup 3/H-Gln), /+-/1nM GnRH (exp 1) or in media containing precursors /+-/ 10nM T and/or 1nM GnRH (exp 2). Radiolabeled precursor incorporation into LH subunits was determined by immunoprecipitation followed by SDS-PAGE. In experiment 1, precursor incorporation into total protein (TP) and LH subunits increased linearly with time for at least 8h. GnRH did not effect precursor incorporation in to TP or /sup 35/S-Met labeling of LH subunits, but stimulated a linear, time-dependent accumulation of /sup 3/H-Gln into total LH subunits and the release of RIA-LH and radiolabeled subunits into media. Based on these results, the effects of T on LH subunit biosynthesis were studied during an 8h incubation. In experiment 2, GnRH enhanced the total /sup 3/H-Gln incorporation (but not /sup 35/S-Met incorporation) into both LH subunits. GnRH stimulated the release of /sup 35/S-Met LH..cap alpha.. and /sup 3/H-Gln LH subunits into media and increased the relative glycosylation of secreted LH subunits without altering the relative glycosylation of intracellular LH subunits. T inhibited RIA-LH release and incorporation of both precursors into total and secreted LH subunits (/+-/GnRH). However, only the relative glycosylation of secreted LH..cap alpha.. was reduced by T (/+-/GnRh).

  20. 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.

  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. Ovulation Prediction by using Urine LH Rapid Determination Combinedwith Cervical Mucus Score

    Institute of Scientific and Technical Information of China (English)

    吴宇芬; 狄文; 桂彪; 张惠英; 金忆; 肖宇红; 丁青; 王寒正; 孙志达; 沈维雄

    1993-01-01

    Infertility may be induced by many causes. It is partly due to the inappropriate time of intercourse from ignorance of the date of ovulation by the infertile couples.Basal body temperature, cervical mucus, B-ultrasonography, blood LH ( luteinizing hormone ) and sex-steroid hormone assay are the common methods used for monitoring ovulation.

  3. 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...

  4. 2-bromopalmitate inhibition of stimulatory effect on LH in isolated luteal cells.

    Science.gov (United States)

    Tan, C H; Robinson, J

    1982-04-05

    The effect of 2-bromopalmitate, an inhibitor of fatty acids oxidation, on progesterone synthesis in isolated luteal cells was studied. Incubation of the cells with increasing concentrations (0 - 2 mM) of the inhibitor resulted in an initial enhancement of progesterone synthesis, both in the presence and absence of LH (1 microgram/ml). In the LH-treated cells, this stimulation in steroid synthesis becomes markedly impaired at 2 mM 2-bromopalmitate. In the control cells, however, progesterone synthesis was sustained at the elevated level. At high concentrations of 2-bromopalmitate, the stimulatory effect of LH (relative to the controls) on steroidogenesis was progressively diminished, until it was completely abolished at an inhibitor concentration of 2 mM. The oxidation of labelled palmitic acid by luteal cells was also effectively inhibited by 2-bromopalmitate (1 mM). The results indicate that the steroidogenic effect of LH is mediated, in part, by fatty acid oxidation, and were explained in terms of the interaction between carbohydrate and fatty acid oxidation in supporting ovarian steroidogenesis.

  5. A General Approach to L(h, k)-Label Interconnection Networks

    Institute of Scientific and Technical Information of China (English)

    Tiziana Calamoneri; Saverio Caminiti; Rossella Petreschi

    2008-01-01

    Given two non-negative integers h and k, an L(h, k)-labelin9 of a graph G = (V, E) is a function from the set V to a set of colors, such that adjacent nodes take colors at distance at least h, and nodes at distance 2 take colors at distanceat least k. The aim of the L(h, k)-labeling problem is to minimize the greatest used color. Since the decisional version of this problem is NP-complete, it is important to investigate particular classes of graphs for which the problem can be efficiently solved. It is well known that the most common interconnection topologies, such as Butterfly-like, Benes, CCC, Trivalent Cayley networks, are all characterized by a similar structure: they have nodes organized as a matrix and connections are divided into layers. So we naturally introduce a new class of graphs, called (l×n)-multistage graphs, containing the most common interconnection topologies, on which we study the L(h, k)-labeling. A general algorithm for L(h, k)-labeling these graphs is presented, and from this method an efficient L(2, 1)-labeling for Butterfly and CCC networks is derived. Finally we describe a possible generalization of our approach.

  6. LH receptor gene expression is essentially absent in breast tumor tissue: Implications for treatment

    NARCIS (Netherlands)

    T.M. Kuijper (Martijn); K. Ruigrok-Ritstier (Kirsten); M. Verhoef-Post (Miriam); D. Piersma (Djura); M.W.P. Bruysters (Martijn); P.M.J.J. Berns (Els); A.P.N. Themmen (Axel)

    2009-01-01

    textabstractWorldwide, breast cancer is the most frequently occurring malignancy in women. Early age at full term pregnancy has a protective effect against breast cancer. Evidence coming from a rat breast cancer model suggests a possible role for the pregnancy hormone hCG, a ligand of the LH recepto

  7. 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...

  8. 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

    2013-07-01

    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.

  9. Carotenoid-bacteriochlorophyll energy transfer in LH2 complexes studied with 10-fs time resolution.

    Science.gov (United States)

    Polli, Dario; Cerullo, Giulio; Lanzani, Guglielmo; De Silvestri, Sandro; Hashimoto, Hideki; Cogdell, Richard J

    2006-04-01

    In this report, we present a study of carotenoid-bacteriochlorophyll energy transfer processes in two peripheral light-harvesting complexes (known as LH2) from purple bacteria. We use transient absorption spectroscopy with approximately 10 fs temporal resolution, which is necessary to observe the very fast energy relaxation processes. By comparing excited-state dynamics of the carotenoids in organic solvents and inside the LH2 complexes, it has been possible to directly evaluate their energy transfer efficiency to the bacteriochlorophylls. In the case of okenone in the LH2 complex from Chromatium purpuratum, we obtained an energy transfer efficiency of etaET2=63+/-2.5% from the optically active excited state (S2) and etaET1=61+/-2% from the optically dark state (S1); for rhodopin glucoside contained in the LH2 complex from Rhodopseudomonas acidophila these values become etaET2=49.5+/-3.5% and etaET1=5.1+/-1%. The measurements also enabled us to observe vibrational energy relaxation in the carotenoids' S1 state and real-time collective vibrational coherence initiated by the ultrashort pump pulses. Our results are important for understanding the dynamics of early events of photosynthesis and relating it to the structural arrangement of the chromophores.

  10. De testosteron produktietest. Een specifieke in vitro biologische bepaling van luteiniserend hormoon (LH)

    NARCIS (Netherlands)

    van Ginkel LA; Loeber JG

    1983-01-01

    Een in vitro biologische bepaling voor luteiniserend hormoon (LH), de testosteron produktietest (TPA) in muize Leydig cellen, werd opgezet. De meting van het geproduceerde testosteron vindt plaats met behulp van een radioimmunochemische methode. De dosis-werkingscurve geeft, indien de testosteron

  11. Heat loads on JET plasma facing components from ICRF and LH wave absorption in the SOL

    Science.gov (United States)

    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.; Petrzilka, V.; Portafaix, C.; Rimini, F.; Sirinelli, A.; Riccardo, V.; Vizvary, Z.; Widdowson, A.; Zastrow, K.-D.; EFDA Contributors, JET

    2011-10-01

    In JET, lower hybrid (LH) and ion cyclotron resonance frequency (ICRF) wave absorption in the scrape-off layer can lead to enhanced heat fluxes on some plasma facing components (PFCs). Experiments have been carried out to characterize these heat loads in order to: (i) prepare JET operation with the Be wall which has a reduced power handling capability as compared with the carbon wall and (ii) better understand the physics driving these wave absorption phenomena and propose solutions for next generation systems to reduce them. When using ICRF, hot spots are observed on the antenna structures and on limiters close to the powered antennas and are explained by acceleration of ions in RF-rectified sheath potentials. High temperatures up to 800 °C can be reached on locations where a deposit has built up on tile surfaces. Modelling which takes into account the fast thermal response of surface layers can reproduce well the surface temperature measurements via infrared (IR) imaging, and allow evaluation of the heat fluxes local to active ICRF antennas. The flux scales linearly with the density at the antenna radius and with the antenna voltage. Strap phasing corresponding to wave spectra with lower kpar values can lead to a significant increase in hot spot intensity in agreement with antenna modelling that predicts, in that case, an increase in RF sheath rectification. LH absorption in front of the antenna through electron Landau damping of the wave with high Npar components generates hot spots precisely located on PFCs magnetically connected to the launcher. Analysis of the LH hot spot surface temperature from IR measurements allows a quantification of the power flux along the field lines: in the worst case scenario it is in the range 15-30 MW m-2. The main driving parameter is the LH power density along the horizontal rows of the launcher, the heat fluxes scaling roughly with the square of the LH power density. The local electron density in front of the grill increases

  12. Increased basal and pulsatile secretion of FSH and LH in young men with 47,XXY or 46,XX karyotypes

    DEFF Research Database (Denmark)

    Aksglaede, L.; Jensen, Rikke Bodin Beck; Carlsen, E.;

    2008-01-01

    basal, pulsatile, and total LH and FSH secretion were associated with significantly more LH peaks per 24 h in comparison with healthy controls. Thus, our data indicate that in patients with Klinefelter syndrome and XX male karyotypes the entire hypothalamic-pituitary-gonadal axis has undergone...

  13. Effect of Photo-Oxidation on Energy Transfer in Light Harvesting Complex (LH2) from Rhodobacter Sphaeroides 601

    Institute of Scientific and Technical Information of China (English)

    LIU Kang-Jun; LIU Wei-Min; YAN Yong-Li; DONG Zhi-Wei; LIU Yuan; XU Chun-He; QIAN Shi-Xiong

    2006-01-01

    @@ We study the photo-oxidation of bacteriochlorophylls (BChls) in peripheral light harvesting complexes (LH2) from rhodobacter sphaeroides by using the steady absorption and the femtosecond pump-probe measurement, to realize the detailed dynamics of LH2 in the presence of photo-oxidation.

  14. The involvement of luteinizing hormone (LH) and Pregnancy-Associated Glycoprotein family (PAG) in pregnancy maintenance in the pig.

    Science.gov (United States)

    Panasiewicz, Grzegorz; Majewska, Marta; Szafrańska, Bozena

    2004-07-01

    The paper presents the effect of in vivo immuno-neutralization of porcine luteinizing hormone (pLH) by species-homologous porcine antiserum (anti-pLH) administrations on pregnancy maintenance and immunodetection of the PAG proteins in precipitated plasma proteins of pregnant gilts. Pregnant gilts were passively immunized with 100 ml of porcine anti-pLH (titer 1:10 000) by multiple intravenous infusions performed from 37(th) to 42(nd) day post coitum (dpc; 12-h intervals). Blood samples of pregnant gilts were taken 12 times daily from 35 until 50 dpc. Concentrations of progesterone (P(4)) and pLH were determined by radioimmunoassays in systemic blood plasma of treated gilts and control pregnant gilts. The immuno-neutralization of peripheral pLH with the use of homologous anti-pLH serum resulted in a significant reduction (ppLH) did not affect the pregnancy maintenance. Thus, the maintenance of mid-pregnancy in gilts may depend also on other than LH luteotrophic factors. In addition, Western analysis of precipitated plasma proteins of pregnant pigs suggests a role of the PAG family during pregnancy in the pig.

  15. A SELF-PRIMING EFFECT OF LHRH ON LH SECRETION IN DISPERSED ANTERIOR PITUITARY CELLS OF ADULT MALE RAT

    Institute of Scientific and Technical Information of China (English)

    QUZhi-Chao; GUOJing; GUOJian

    1989-01-01

    LHRH self-priming effect is simply defmed as an enhancement of LH response to LHRH, i. e., a second challenge with LHRH elicits more LH secretion as compared to the first challenge. The present study is to observe whether this phenomenon exists in perfused anterior pituitary (AP) cells of adult male rat. Dispersed AP cells of adult SD

  16. A STUDY ON SERUM FSH, LH AND PROLACTIN LEVELS AMONG INFERTILE WOMEN

    Directory of Open Access Journals (Sweden)

    Prasad Bheem, Parmar Dinesh, Sharma Nc

    2015-10-01

    Full Text Available Background: Study of hormonal imbalance and its implications in female infertility are an interesting area that requires to be explored in recent time. Hormonal imbalance can associated with irregular menstrual cycle, Amenorrhea, obesity and infertility in women. Other medical conditions such as polycystic ovarian syndrome, Endometriosis, stress, sexually transmitted diseases and chromosomal anomalies may be responsible for infertility in females. Objective: The aim of the present study was to evaluate the serum levels of Follicle Stimulating hormone (FSH, Luteinizing hormone (LH and Prolactin hormone in infertile women that were referred from different infertility clinics and centres. Materials and Methods: This study comprises total 176 female subjects with age ranging from 20 to 40 years and divided in two groups. The total number of 88 infertile women along with 88 fertile women as controls was included for the present study. Serum FSH, LH and Prolactin levels were estimated by enzyme-linked immunosorbent assay (ELISA methods. Results: The results showed maximum infertile women were found between the age group of 30-40 years. The Serum FSH, LH and Prolactin levels among infertile women was 8.77±4.65, 7.64±5.16 and 18.59±7.50 respectively. Whereas, levels of FSH, LH and Prolactin in fertile women showed that 6.71±4.12, 5.66±3.17 and 13.44±5.82 respectively. Conclusion: In this study, we found that the hormone levels have statistically significant with female infertility. The elevated levels of FSH, LH and Prolactin may be one of the important causes for infertility in women.

  17. The unexpected, long-lasting, UV rebrightening of the superluminous supernova ASASSN-15lh

    Science.gov (United States)

    Godoy-Rivera, D.; Stanek, K. Z.; Kochanek, C. S.; Chen, Ping; Dong, Subo; Prieto, J. L.; Shappee, B. J.; Jha, S. W.; Foley, R. J.; Pan, Y.-C.; Holoien, T. W.-S.; Thompson, Todd. A.; Grupe, D.; Beacom, J. F.

    2017-04-01

    Given its peak luminosity and early-time spectra, ASASSN-15lh was classified as the most luminous supernova ever discovered. Here, we report a UV rebrightening of ASASSN-15lh observed with Swift during our follow-up campaign. The rebrightening began at t ≃ 90 d (observer frame) after the primary peak and was followed by a ∼120-d long plateau in the bolometric luminosity, before starting to fade again at t ≃ 210 d. ASASSN-15lh rebrightened in the Swift UV bands by ΔmUVW2 ≃ -1.75 mag, ΔmUVM2 ≃ -1.25 mag and ΔmUVW1 ≃ -0.8 mag, but did not rebrighten in the optical bands. Throughout its initial decline, subsequent rebrightening and renewed decline, the spectra did not show evidence of interactions between the ejecta and circumstellar medium such as narrow emission lines. There are hints of weak Hα emission at late-times, but Margutti et al. have shown that it is narrow line emission consistent with star formation in the host nucleus. By fitting a blackbody, we find that during the rebrightening, the effective photospheric temperature increased from TBB ≃ 11 000 K to TBB ≃ 18 000 K. Over the ∼ 550 d since its detection, ASASSN-15lh has radiated ∼1.7 -1.9 × 1052 erg. Although its physical nature remains uncertain, the evolution of ASASSN-15lh's photospheric radius, its radiated energy and the implied event rate, are all more similar to those of H-poor superluminous supernovae than to tidal disruption events.

  18. Superovulation of goats with purified pFSH supplemented with defined amounts of pLH.

    Science.gov (United States)

    Nowshari, M A; Backers, J F; Holtz, W

    1995-03-01

    The superovulatory response of goats treated with purified pFSH supplemented with 30, 40 or 50% pLH was compared. Sixty-four Boer goat does were synchronized by progestagen-containing ear implant, randomly allotted to 3 groups and, beginning 2 d before implant removal, treated with purified pFSH supplemented with 30, 40 or 50% pLH. Each animal received 16 Armour Units of pFSH administered in 6 descending doses at 12-h intervals. Along with the last 2 injections, the does received 5 mg PGF(2alpha). Embryos were flushed either surgically or after slaughter on Day 5 or 6 after the last day of standing estrus. The percentage of animals responding to treatment was not different among groups treated with pFSH supplemented with 30, 40 or 50% pLH (76, 71 and 63%, respectively). The corresponding data for number of ovulations was 11.3 +/- 1.6, 16.3 +/- 1.8 and 16.4 +/- 2.6, for number of ova and embryos recovered 8.1 +/- 1.9, 12.0 +/- 1.5 and 13.5 +/- 2.9 and for number of transferable embryos 6.6 +/- 1.9, 9.1 +/- 1.5 and 7.1 +/- 2.1 (x +/- SEM). Results confirm the earlier finding of a good response of goats to pFSH preparations with a high FSH:LH ratio, and, although group differences were statistically nonsignificant (P > 0.05), they suggest that supplementation with approximately 40% pLH may be close to the optimum.

  19. The Unexpected, Long-Lasting, UV Rebrightening of the Super-Luminous Supernova ASASSN-15lh

    Science.gov (United States)

    Godoy-Rivera, D.; Stanek, K. Z.; Kochanek, C. S.; Chen, Ping; Dong, Subo; Prieto, J. L.; Shappee, B. J.; Jha, S. W.; Foley, R. J.; Pan, Y.-C.; Holoien, T. W.-S.; Thompson, Todd. A.; Grupe, D.; Beacom, J. F.

    2017-01-01

    Given its peak luminosity and early-time spectra, ASASSN-15lh was classified as the most luminous supernova (SN) ever discovered (Dong et al. 2016).. Here we report a UV rebrightening of ASASSN-15lh observed with Swift during our follow-up campaign. The rebrightening began at t ≃ 90 days (observer frame) after the primary peak and was followed by a ˜120-day long plateau in the bolometric luminosity, before starting to fade again at t ≃ 210 days. ASASSN-15lh rebrightened in the Swift UV bands by ΔmUVW2 ≃ -1.75 mag, ΔmUVM2 ≃ -1.25 mag, and ΔmUVW1 ≃ -0.8 mag, but did not rebrighten in the optical bands. Throughout its initial decline, subsequent rebrightening, and renewed decline, the spectra did not show evidence of interactions between the ejecta and circumstellar medium (CSM) such as narrow emission lines. There are hints of weak Hα emission at late-times, but Margutti et al. (2016) have shown that it is narrow line emission consistent with star formation in the host nucleus. By fitting a blackbody we find that during the rebrightening the effective photospheric temperature increased from TBB ≃ 11000 K to TBB ≃ 18000 K. Over the ˜ 550 days since its detection, ASASSN-15lh has radiated ˜1.7 - -1.9 × 1052 ergs. Although its physical nature remains uncertain, the evolution of ASASSN-15lh's photospheric radius, its radiated energy, and the implied event rate, are all more similar to those of H-poor superluminous supernovae (SLSNe-I) than to tidal disruption events (TDEs).

  20. THEORETICAL,NUMERICAL AND EXPERIMENTAL STUDY OF WATER HAMMER IN PIPE SYSTEM WITH COLUMN SURGE CHAMBER

    Institute of Scientific and Technical Information of China (English)

    Zhou Ze-xuan; Tan Soon Keat

    2003-01-01

    A new kind of governing equations for water hammer based on the elastic column theory was proposed and adopted to analyse water hammer phenomenon in the pipe system with a vertical column surge chamber and water level fluctuation in the surge chamber during pressure transient. The wrongness existing in the classical governing equations for water hammer was analysed. A typical reservoir-valve pipe system was chosen as an example to verify the new governing equations numerically and experimentally. The finite difference method based on the method of characteristics was used to solve numerically the nonlinear characteristic equations. The temporal evolutions of transient volume flux and head and of water level fluctuation for various surge chamber configurations were worked out, assuming that the air in the surge chamber are compressible. The relevant experiment was conducted to verify the new governing equations and numerical method. The numerical and experimental results show that the new governing equations are valid and the conventional assumption that the pressure head at the base of a surge chamber equals that of the static head above it during pressure transient is not always valid. The surge chamber generally reises the period of transient pressure wave in pipe system, reduces the maximum pressure envelope and lifts the minimum envelope substantially. The water level fluctuation in the surge chamber was numerically and experimentally observed. Increasing the size of the surge chamber and/or decreasing the initial air pressure in the surge chamber enhance the effectiveness of the surge chamber in suppressing pressure wave.

  1. Effect of hurricane paths on storm surge response at Tianjin, China

    Science.gov (United States)

    Feng, Xingru; Yin, Baoshu; Yang, Dezhou

    2012-06-01

    A hurricane induced storm surge simulation system was developed for Tianjin coast, which consists of a hurricane model and a storm surge model. The peak storm surge result of the simulation agreed well with that of the observation. Three observed paths (Rita, Mimie and WINNIE) and a hypothetical path (Rita2) were chosen as the selective hurricane paths according to their positions relative to Tianjin. The sensitivity of Tianjin storm surge to the four paths was investigated using the validated storm surge simulation system. Three groups of experiments were done. In group one, the models were forced by the wind field and air pressure; in group two and three the models were forced by the wind only and the air pressure only respectively. In the experiments, the hurricane moved with a fixed speed and an intensity of 50 year return period. The simulation results show that path of the type Rita2 is the easiest to cause storm surge disaster in Tianjin, and the effect of air pressure forcing is most evident for path of the type Rita in Tianjin storm surge process. The above conclusions were analyzed through the evolution of the wind fields and the air pressure distributions. Comparing the experiment results of Group one, two and three, it can be seen that the storm surge is mainly induced by the wind forcing and the nonlinear interaction between the effect of wind forcing and air pressure forcing on the storm surge tends to weaken the storm surge.

  2. Direct Surge Margin Control for Aeroengines Based on Improved SVR Machine and LQR Method

    Directory of Open Access Journals (Sweden)

    Haibo Zhang

    2013-01-01

    Full Text Available A novel scheme of high stability engine control (HISTEC on the basis of an improved linear quadratic regulator (ILQR, called direct surge margin control, is derived for super-maneuver flights. Direct surge margin control, which is different from conventional control scheme, puts surge margin into the engine closed-loop system and takes surge margin as controlled variable directly. In this way, direct surge margin control can exploit potential performance of engine more effectively with a decrease of engine stability margin which usually happened in super-maneuver flights. For conquering the difficulty that aeroengine surge margin is undetectable, an approach based on improved support vector regression (SVR machine is proposed to construct a surge margin prediction model. The surge margin modeling contains two parts: a baseline model under no inlet distortion states and the calculation for surge margin loss under supermaneuvering flight conditions. The previous one is developed using neural network method, the inputs of which are selected by a weighted feature selection algorithm. Considering the hysteresis between pilot input and angle of attack output, an online scrolling window least square support vector regression (LSSVR method is employed to firstly estimate inlet distortion index and further compute surge margin loss via some empirical look-up tables.

  3. LH and hCG Action on the Same Receptor Results in Quantitatively and Qualitatively Different Intracellular Signalling

    Science.gov (United States)

    Casarini, Livio; Lispi, Monica; Longobardi, Salvatore; Milosa, Fabiola; La Marca, Antonio; Tagliasacchi, Daniela; Pignatti, Elisa; Simoni, Manuela

    2012-01-01

    Human luteinizing hormone (hLH) and chorionic gonadotropin (hCG) act on the same receptor (LHCGR) but it is not known whether they elicit the same cellular and molecular response. This study compares for the first time the activation of cell-signalling pathways and gene expression in response to hLH and hCG. Using recombinant hLH and recombinant hCG we evaluated the kinetics of cAMP production in COS-7 and hGL5 cells permanently expressing LHCGR (COS-7/LHCGR, hGL5/LHCGR), as well as cAMP, ERK1/2, AKT activation and progesterone production in primary human granulosa cells (hGLC). The expression of selected target genes was measured in the presence or absence of ERK- or AKT-pathways inhibitors. In COS-7/LHCGR cells, hCG is 5-fold more potent than hLH (cAMP ED50: 107.1±14.3 pM and 530.0±51.2 pM, respectively). hLH maximal effect was significantly faster (10 minutes by hLH; 1 hour by hCG). In hGLC continuous exposure to equipotent doses of gonadotropins up to 36 hours revealed that intracellular cAMP production is oscillating and significantly higher by hCG versus hLH. Conversely, phospho-ERK1/2 and -AKT activation was more potent and sustained by hLH versus hCG. ERK1/2 and AKT inhibition removed the inhibitory effect on NRG1 (neuregulin) expression by hLH but not by hCG; ERK1/2 inhibition significantly increased hLH- but not hCG-stimulated CYP19A1 (aromatase) expression. We conclude that: i) hCG is more potent on cAMP production, while hLH is more potent on ERK and AKT activation; ii) hGLC respond to equipotent, constant hLH or hCG stimulation with a fluctuating cAMP production and progressive progesterone secretion; and iii) the expression of hLH and hCG target genes partly involves the activation of different pathways depending on the ligand. Therefore, the LHCGR is able to differentiate the activity of hLH and hCG. PMID:23071612

  4. Assessment of Spatial Distribution and Submerged Scope for Storm Surge in the Pearl River Delta Region

    Institute of Scientific and Technical Information of China (English)

    LI Kuo; LI Guo-sheng

    2011-01-01

    The aim of this study was to explore the spatial distribution and submerged scope for storm surge in the Pearl River Delta (PRD) region.Based on the data of storm surges in the PRD region in the past 30 years, the return periods of 12 tide-gauge stations for storm surges were calculated separately with the methods of Gumbel and Pearson-iii.The data of another six tide-gauge stations in Guangdong Coast was quoted to depict the overall features of storm surges in Guangdong.Using least-square method, the spatial distribution models of storm surges in different retum periods were established to reveal the distribution rule of the set-up values of storm surges.The spatial distribution curves of storm surges in different retum periods in the PRD Region were drawn up based on the models and the terrain of Guangdong Coast.According to the curves, the extreme set-up values of storm surges in 1 000,100, 10 a return periods were determined on each spot of Guangdong Coast.Applying the spatial analysis technology of ArcGIS, with the topography data of the PRD Region, the submerged scopes of flood caused by storm surge in 1 000, 100, 10 a return periods were drawn up.The loss caused by storm surges was estimated.Results showed that the storm surges and the topography of PRD region jointly led to the serious flood in the PRD region.This assessment would be useful for the planning and design department to make decision and provide government scientific basis for storm surge prediction, coastal engineering designing and the prevention of storm surge disaster.

  5. Surges of outlet glaciers from the Drangajökull ice cap, northwest Iceland

    Science.gov (United States)

    Brynjólfsson, Skafti; Schomacker, Anders; Korsgaard, Niels J.; Ingólfsson, Ólafur

    2016-09-01

    Surface elevation and volume changes of the Drangajökull surge-type glaciers, Reykjarfjarðarjökull and Leirufjarðarjökull, were studied by comparing digital elevation models that pre-date and post-date their most recent surges. Annual glacier-frontal measurements were used to estimate average ice velocities during the last surge of the glaciers. The observations show a distinct ice discharge, most of which was from the upper reservoir areas, down to the receiving areas during the surges. The surface draw-down in the reservoir areas was usually 10-30 m during the surges, while the thickening of the receiving areas was significantly more variable, on the order of 10-120 m. Despite a negative geodetic net mass balance derived from the digital elevation models, the reservoir areas have been gaining mass since the surge terminations. This surface thickening along with considerable ablation of the receiving areas will most likely return the glacier surface profiles to the pre-surge stage. Our results indicate that (a) greatest surface thinning in the upper reservoir areas of Drangajökull rather than proximal to the equilibrium line during Vatnajökull surges and (b) development of Drangajökull surges that resembles Svalbard surge-type glaciers rather than Vatnajökull surge-type glaciers. The contrasting surge characteristics could be explained by differences in glacier geometry, topography and substratum of the Drangajökull and Vatnajökull surge-type glaciers.

  6. 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...... is investigated with bifurcation theory of dynamical systems. The analysis shows that the model contains three types of transitions: an oscillating transition, a sharp transition with hysteresis, and a smooth transition. The model is recognized as a slow-fast system. A reduced 2-ODE model consisting of the full...... model restricted to the flow on the critical manifold is found to contain all the same dynamics as the full model. This means that all the dynamics in the system is essentially 2-dimensional, and a minimal model of the L-H transition could be a 2-ODE model....

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

    Science.gov (United States)

    Dam, Magnus; Brøns, Morten; Juul Rasmussen, Jens; Naulin, Volker; Xu, Guosheng

    2013-10-01

    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 is investigated with bifurcation theory of dynamical systems. The analysis shows that the model contains three types of transitions: an oscillating transition, a sharp transition with hysteresis, and a smooth transition. The model is recognized as a slow-fast system. A reduced 2-ODE model consisting of the full model restricted to the flow on the critical manifold is found to contain all the same dynamics as the full model. This means that all the dynamics in the system is essentially 2-dimensional, and a minimal model of the L-H transition could be a 2-ODE model.

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

    Energy Technology Data Exchange (ETDEWEB)

    Dam, Magnus; Brøns, Morten [Department of Applied Mathematics and Computer Science, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Juul Rasmussen, Jens; Naulin, Volker [Association Euratom-DTU, Department of Physics, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde (Denmark); Xu, Guosheng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2013-10-15

    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 is investigated with bifurcation theory of dynamical systems. The analysis shows that the model contains three types of transitions: an oscillating transition, a sharp transition with hysteresis, and a smooth transition. The model is recognized as a slow-fast system. A reduced 2-ODE model consisting of the full model restricted to the flow on the critical manifold is found to contain all the same dynamics as the full model. This means that all the dynamics in the system is essentially 2-dimensional, and a minimal model of the L-H transition could be a 2-ODE model.

  9. In vitro effect of leptin on anterior pituitary cells LH secretory activity during early pregnancy in pig.

    Science.gov (United States)

    Siawrys, G; Gajewska, A

    2017-03-28

    Leptin modulates reproductive activity but its potential influence on LH secretion from anterior pituitary (AP) cells during implantation period in pigs (days 14-16 of pregnancy) remained unexplored. This study focused on determination whether leptin affects basal and GnRH-induced LH secretion and intracellular accumulation and whether leptin receptor (OB-Rb) mRNA is expressed in the AP gland during implantation in pigs. Four individual AP glands were developed into separate primary cultures. 2×105 cells/ml were preincubated (72 h) and next, for 3.5 h, experimentally treated with GnRH (100 ng/ml), leptin (10-11, 10-9, 10-7, 10-6 M) alone, or given in respective combinations with GnRH. In the AP gland, OB-Rb mRNA expression was determined by real-time PCR method. Leptin activated LH secretion and its concentration-dependent effect was observed as stimulation shown in a full range tested (culture 1) and exhibited only at 10-6 M (culture 2). A pooled data analysis revealed that basal LH secretion increased at 10-9, 10-7 and 10-6 M, but GnRH-induced LH release decreased at 10-6 M. Leptin down-regulated GnRH-induced LH secretion in all cultures, but only culture 3 exhibited sensitivity for all concentrations tested. Basal LH accumulation was activated in culture 1 (at 10-11 M) and inhibited in culture 4 (at 10-9 M). In the presence of GnRH leptin up-regulated LH accumulation with individual culture leptin-sensitivity (culture 1-3), while down-regulated LH accumulation in culture 4. Obtained data indicate that OB-Rb mRNA is expressed in the AP gland and leptin alone and in combination with GnRH specifically modulates LH activity during early pregnancy in pigs.

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

    Science.gov (United States)

    Bathi, Jejal Reddy; Das, Himangshu S

    2016-02-19

    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.

  11. Two parametric tropical cyclone models for storm surge modeling

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-li

    2010-01-01

    In this paper,the two parametric tropical cyclone models for storm surge modeling are further developed.The analytical expressions of tangential and radial velocity distribution are derived from the governing momentum equations,based on the general symmetric pressure distribution proposed by Holland and Fujita.On the basis of the data of several tropical cyclones that occurred in East China Ocean,the shape parameter in pressure model is estimated.Finally,the Fred cyclone(typhoon 199417)is calculated,and comparisons of measured and calculated air pressures and wind speed are presented.

  12. Probabilistic modelling of sea surges in coastal urban areas

    Science.gov (United States)

    Georgiadis, Stylianos; Jomo Danielsen Sørup, Hjalte; Arnbjerg-Nielsen, Karsten; Nielsen, Bo Friis

    2016-04-01

    Urban floods are a major issue for coastal cities with severe impacts on economy, society and environment. A main cause for floods are sea surges stemming from extreme weather conditions. In the context of urban flooding, certain standards have to be met by critical infrastructures in order to protect them from floods. These standards can be so strict that no empirical data is available. For instance, protection plans for sub-surface railways against floods are established with 10,000 years return levels. Furthermore, the long technical lifetime of such infrastructures is a critical issue that should be considered, along with the associated climate change effects in this lifetime. We present a case study of Copenhagen where the metro system is being expanded at present with several stations close to the sea. The current critical sea levels for the metro have never been exceeded and Copenhagen has only been severely flooded from pluvial events in the time where measurements have been conducted. However, due to the very high return period that the metro has to be able to withstand and due to the expectations to sea-level rise due to climate change, reliable estimates of the occurrence rate and magnitude of sea surges have to be established as the current protection is expected to be insufficient at some point within the technical lifetime of the metro. The objective of this study is to probabilistically model sea level in Copenhagen as opposed to extrapolating the extreme statistics as is the practice often used. A better understanding and more realistic description of the phenomena leading to sea surges can then be given. The application of hidden Markov models to high-resolution data of sea level for different meteorological stations in and around Copenhagen is an effective tool to address uncertainty. For sea surge studies, the hidden states of the model may reflect the hydrological processes that contribute to coastal floods. Also, the states of the hidden Markov

  13. 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

  14. Surge-tectonic evolution of southeastern Asia: a geohydrodynamics approach

    Science.gov (United States)

    Meyerhoff, Arthur A.

    The repeated need for ad hoc modifications in plate-tectonic models to explain the evolution of southeastern Asia reveals their inability to fully explain the complex features and dynamics of this region. As one example, the hypothesis does not provide a mechanism to explain the 180° turns and twists along the strike of several foldbelts and island arcs in the region (e.g. Banda arc). Convection-cell configuration renders such 180° contortions and Rayleigh-Bénard-type convection impossible. However, during the last 10 years, new data bearing on the convection-cell problem have become available in the form of seismotomographic images of the earth's interior. These images show that (i) mantle diapirs as proposed by traditional plate-tectonic models do not exist; (ii) there is no discernible pattern of upper or lower mantle convection, and thus no longer an adequate mechanism to move plates; and (iii) the lithosphere above a depth of about 80 km is permeated by an interconnected network of low-velocity channels. Seismic-reflection studies of the low-velocity channels discovered on the seismotomographic images reveal that these channels have walls with a 7.1-7.8 km s -1 P-wave velocity. Commonly, the interiors of the channels are acoustically transparent, with much slower P-wave velocities, in places as low as 5.4 km s -1. The author and co-workers have interpreted the low velocities as evidence for the presence of partial melt in the channels, and they postulated that this melt moves preferentially eastward as a result of the earth's rotation. They named these channels "surge channels" and their new hypothesis for earth dynamics "surge tectonics". Surge channels underlie every type of tectonic belt, which includes mid-ocean ridges, aseismic ridges, continental rifts, strike-slip fracture zones, and foldbelts. In southeastern Asia, surge channels—mainly foldbelts—lie between all platform and cratonic massifs. These massifs, platforms, and tectonics belts

  15. 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...

  16. 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

  17. Production of specific antisera for radioimmunoassay of human luteinizing hormone (LH) in the presence of human chorionic gonadotropin (hCG). [/sup 125/I

    Energy Technology Data Exchange (ETDEWEB)

    Thorell, J.I.; Jeppsson, S.; Holmstrom, B.

    1976-09-01

    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 /sup 125/I-LH was used in a double antibody assay. The LH standard (MRC/68/40) efficiently inhibited the binding of /sup 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 /sup 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.

  18. Simulation of Storm Surge and Wave Due to Typhoon Isewan (5915)

    Institute of Scientific and Technical Information of China (English)

    Jin-Hee YUK; Kyeong Ok KIM; Han Soo LEE; Byung Ho CHOI

    2015-01-01

    An integrally coupled wave-tide-surge model was developed and then applied to the simulation of the wave-typhoon surge for the typhoon Isewan (typhoon Vera (5915)), which is the strongest typhoon that has struck Japan and caused incalculable damage. An integrally coupled tide-surge-wave model using identical and homogeneous meshes in an unstructured grid system was used to correctly resolve the physics of wave-circulation interaction in both models. All model components were validated independently. The storm surge and wave properties such as the surge height, the significant wave height, wave period and direction were reproduced reasonably under the meteorological forcing, which was reprocessed to be close to the observations. The resulting modeling system can be used extensively for the prediction of the storm surge and waves and the usual barotropic forecast.

  19. Effectiveness of installing two pairs of distribution surge arresters in parallel

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Hitoshi; Asakawa, Akira; Yokoyama, Shigeru [Central Research Institute of Electric Power Industry (Japan); Nakada, Kazuo [Hokurika Electric Power Co. (Japan)

    1999-07-01

    Lightning strokes with a large amount of energy sometimes occur on the Sea of Japan coast in winter. Winter lightning often damages overhead power distribution lines, in particular, those supplying power to high structures located in mountainous areas. We have investigated that the ratio of surge arrester outages with respect to all damaged installations on such power distribution lines is largest at approximately 50%. We have examined the effectiveness of installing two pairs of surge arresters in parallel on a single pole as a method for preventing distribution surge arrester outages experimentally. We have clarified that to install surge arresters in parallel is effective in reducing the energy absorbed by surge arresters if these surge arresters have almost the same discharge voltage and voltage-current characteristics. (author)

  20. L-H power threshold studies in JET with Be/W and C wall

    Science.gov (United States)

    Maggi, C. F.; Delabie, E.; Biewer, T. M.; Groth, M.; Hawkes, N. C.; Lehnen, M.; de la Luna, E.; McCormick, K.; Reux, C.; Rimini, F.; Solano, E. R.; Andrew, Y.; Bourdelle, C.; Bobkov, V.; Brix, M.; Calabro, G.; Czarnecka, A.; Flanagan, J.; Lerche, E.; Marsen, S.; Nunes, I.; Van Eester, D.; Stamp, M. F.; EFDA Contributors, JET

    2014-02-01

    A comparison of the L-H power threshold (Pthr) in JET with all carbon, JET-C, and beryllium/tungsten wall (the ITER-like choice), JET-ILW, has been carried out in experiments with slow input power ramps and matched plasma shapes, divertor configuration and IP/BT pairs. The low density dependence of the L-H power threshold, namely an increase below a minimum density ne,min, which was first observed in JET with the MkII-GB divertor and C wall and subsequently not observed with the current MkII-HD geometry, is observed again with JET-ILW. At plasma densities above ne,min, Pthr is reduced by ˜30%, and by ˜40% when the radiation from the bulk plasma is subtracted (Psep), with JET-ILW compared to JET-C. At the L-H transition the electron temperature at the edge, where the pedestal later develops, is also lower with JET-ILW, for a given edge density. With JET-ILW the minimum density is found to increase roughly linearly with magnetic field, n_{e,min} \\sim B_{T}^{4/5} , while the power threshold at the minimum density scales as P_{sep,\\min} \\sim B_{T}^{5/2} . The H-mode power threshold in JET-ILW is found to be sensitive both to variations in main plasma shape (Psep decreases with increasing lower triangularity and increases with upper triangularity) and in divertor configuration. When the data are recast in terms of Psep and Zeff or subdivertor neutral pressure a linear correlation is found, pointing to a possible role of Zeff and/or subdivertor neutral pressure in the L-H transition physics. Depending on the chosen divertor configuration, Pthr can be up to a factor of two lower than the ITPA scaling law for densities above ne,min. A shallow edge radial electric field well is observed at the L-H transition. The edge impurity ion poloidal velocity remains low, close to its L-mode values, ⩽5 km s-1 ± 2-3 km s-1, at the L-H transition and throughout the H-mode phase, with no measureable increase within the experimental uncertainties. The edge toroidal rotation

  1. Effect of PSD on Acoustic Cavitation Surge in Inlet Pipe of Turbopump

    OpenAIRE

    吉田, 義樹; 藤原, 徹也; 南里, 秀明; Yoshida, Yoshiki; Fujiwara, Tetsuya; Nanri, Hideaki

    2013-01-01

    To investigate the effect of PSD on acoustic cavitation surge in turbopump, we conducted analyses with the resistance of PSD as a parameter. Consequently, we found that patterns of the acoustic cavitation surge were classified into three types by the value of the resistance. (1) First (the resistance of the PSD is smaller.), when the frequency of the inertial cavitation surge between the PSD and the turbopump coincides with the acoustic natural frequencies between the tank and the PSD, the ac...

  2. 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.

  3. 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.

  4. The 1982 eruptions of El Chichon volcano, Mexico (3): Physical properties of pyroclastic surges

    Science.gov (United States)

    Sigurdsson, H.; Carey, S. N.; Fisher, R. V.

    1987-04-01

    Two major pyroclastic surges generated during the 4 April 1982 eruption of El Chichon devastated an area of 153 km2 with a quasi-radial distribution around the volcano. The hot surge clouds carbonized wood throughout their extent and were too hot to allow accretionary lapilli formation by vapor condensation. Field evidence indicates voidage fraction of 0.99 in the surge cloud with extensive entrainment of air. Thermal calculations indicate that heat content of pyroclasts can heat entrained air and maintain high temperatures in the surge cloud. The dominant bed form of the surge deposits are sand waves shaped in dune forms with vertical form index of 10 20, characterized by stoss-side erosion and lee-side deposition of 1 10 cm reversely graded laminae. A systematic decrease in maximum lithic diameter with distance from source is accompanied by decrease in wavelength and amplitude. Modal analysis indicates fractionation of glass and pumice from the surge cloud relative to crystals, resulting in loss of at least 10% 25% of the cloud mass due to winnowing out of fines during surge emplacement. Greatest fractionation from the -1.0 0.0-∅ grain sizes reflects relatively lower pumice particle density in this range and segregation in the formative stages of the surge cloud. Extensive pumice rounding indicates abrasion during bed-load transport. Flow of pyroclastic debris in the turbulent surge cloud was by combination of bed-load and suspended-load transport. The surges are viewed as expanding pyroclastic gravity flows, which entrain and mix with air during transport. The balance between sedimentation at the base of the surge cloud and expansion due to entrainment of air contributed to low cloud density and internal turbulence, which persisted to the distal edge of the surge zone.

  5. A surge of Perseibreen, Svalbard, examined using aerial photography and ASTER high resolution satellite imagery

    OpenAIRE

    Dowdeswell, Julian A.; Benham, Toby J.

    2003-01-01

    The identification of surge activity is important in assessing the duration of the active and quiescent phases of the surge cycle of Svalbard glaciers. Satellite and aerial photographic images are used to identify and describe the form and flow of Perseibreen, a valley glacier of 59 km2 on the east coast of Spitsbergen. Heavy surface crevassing and a steep ice front, indicative of surge activity, were first observed on Perseibreen in April 2002. Examination of high resolution (15 m) Advanced ...

  6. 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

  7. Projections of extreme storm surge levels along Europe

    Science.gov (United States)

    Vousdoukas, Michalis I.; Voukouvalas, Evangelos; Annunziato, Alessandro; Giardino, Alessio; Feyen, Luc

    2016-11-01

    Storm surges are an important coastal hazard component and it is unknown how they will evolve along Europe's coastline in view of climate change. In the present contribution, the hydrodynamic model Delft3D-Flow was forced by surface wind and atmospheric pressure fields from a 8-member climate model ensemble in order to evaluate dynamics in storm surge levels (SSL) along the European coastline (1) for the baseline period 1970-2000; and (2) during this century under the Representative Concentration Pathways RCP4.5 and RCP8.5. Validation simulations, spanning from 2008 to 2014 and driven by ERA-Interim atmospheric forcing, indicated good predictive skill (0.06 m relative sea level rise (RSLR), can be further enforced by an increase of the extreme SSL, which can exceed 30 % of the RSLR, especially for the high return periods and pathway RCP8.5. This implies that the combined effect could increase even further anticipated impacts of climate change for certain European areas and highlights the necessity for timely coastal adaptation and protection measures. The dataset is publicly available under this link: http://data.jrc.ec.europa.eu/collection/LISCOAST.

  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. 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.

  10. Blunting post-meal glucose surges in people with diabetes

    Institute of Scientific and Technical Information of China (English)

    Elsamma; Chacko

    2016-01-01

    Worldwide, the morbidity and mortality associated with non-communicable diseases have been climbing steadily- with costs aggressively keeping pace. This letter highlights a decidedly low-cost way to address the challenges posed by diabetes. High levels of postprandial blood glucose are disproportionately linked to much of the microvascular damage which, in the end, leads to macrovascular complications and organ failures. Systematically controlling post-meal glucose surges is a critical element of overall glycemic management indiabetes. Diet, exercise and medications form a triad of variables that individuals engaged in diabetes selfmanagement may manipulate to achieve their targeted glucose levels. As a rule, diabetes patients in developing countries as well as those living in the pockets of poverty in the western world cannot afford special diets, medications, glucometers and supplies, lab tests and office visits. Exercise is the one option that is readily accessible to all. Decades of research in laboratory settings, viewed holistically, have established that light to moderate aerobic exercise for up to 60 min starting 30 min after the first bite into a meal can blunt the ensuing glucose surge effectively. Moderate resistance exercise, moderate endurance exercise or a combination of the two, practiced post-meal has also been found to improve many cardio-metabolic markers: Glucose, high density lipoprotein, triglycerides, and markers of oxidative stress. On the other hand, pre-breakfast exercise and high-intensity exercise in general have been decidedly counterproductive.

  11. Avoiding compressor surge during emergency shutdown hybridturbine systems

    Energy Technology Data Exchange (ETDEWEB)

    Pezzini, Paolo [University of Genova, Italy; Tucker, David [U.S. DOE; Traverso, Alberto [University of Genova, Italy

    2013-01-01

    A new emergency shutdown procedure for a direct-fired fuel cell turbine hybrid power system was evaluated using a hardware-based simulation of an integrated gasifier/fuel cell/turbine hybrid cycle (IGFC), implemented through the Hybrid Performance (Hyper) project at the National Energy Technology Laboratory, U.S. Department of Energy (NETL). The Hyper facility is designed to explore dynamic operation of hybrid systems and quantitatively characterize such transient behavior. It is possible to model, test, and evaluate the effects of different parameters on the design and operation of a gasifier/fuel cell/gas turbine hybrid system and provide a means of quantifying risk mitigation strategies. An open-loop system analysis regarding the dynamic effect of bleed air, cold air bypass, and load bank is presented in order to evaluate the combination of these three main actuators during emergency shutdown. In the previous Hybrid control system architecture, catastrophic compressor failures were observed when the fuel and load bank were cut off during emergency shutdown strategy. Improvements were achieved using a nonlinear fuel valve ramp down when the load bank was not operating. Experiments in load bank operation show compressor surge and stall after emergency shutdown activation. The difficulties in finding an optimal compressor and cathode mass flow for mitigation of surge and stall using these actuators are illustrated.

  12. 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)

  13. 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.

  14. Regional frequency analysis of extreme storm surges along the French coast

    Directory of Open Access Journals (Sweden)

    L. Bardet

    2011-06-01

    Full Text Available A good knowledge of extreme storm surges is necessary to ensure protection against flood. In this paper we introduce a methodology to determine time series of skew surges in France as well as a statistical approach for estimating extreme storm surges. With the aim to cope with the outlier issue in surge series, a regional frequency analysis has been carried out for the surges along the Atlantic coast and the Channel coast. This methodology is not the current approach used to estimate extreme surges in France. First results showed that the extreme events identified as outliers in at-site analyses do not appear to be outliers any more in the regional empirical distribution. Indeed the regional distribution presents a curve to the top with these extreme events that a mixed exponential distribution seems to recreate. Thus, the regional approach appears to be more reliable for some sites than at-site analyses. A fast comparison at a given site showed surge estimates with the regional approach and a mixed exponential distribution are higher than surge estimates with an at-site fitting. In the case of Brest, the 1000-yr return surge is 167 cm in height with the regional approach instead of 126 cm with an at-site analysis.

  15. Brief Communication: Twelve-year cyclic surging episode at Donjek Glacier in Yukon, Canada

    Directory of Open Access Journals (Sweden)

    T. Abe

    2015-11-01

    Full Text Available Surge-type glaciers repeat their short active phase and much longer quiescent phase usually every several decades or longer, but detailed observations of the evolution cycles have been limited to a few glaciers. Here we report three surging episodes in 1989, 2001, and 2013 at Donjek Glacier in the Yukon, indicating remarkably regular and short repeat cycles of 12 years. The surging area is limited within the ~ 20 km section from the terminus, where the flow width significantly narrows than upstream, suggesting a strong control of the valley constriction on the surge dynamics.

  16. Dynamics of surge-type glaciers in West Kunlun Shan, Northwestern Tibet

    Science.gov (United States)

    Yasuda, Takatoshi; Furuya, Masato

    2015-11-01

    Here we examine 31 glaciers in the West Kunlun Shan of the northwestern Tibetan Plateau and identify 9 as surge type. The method is based on satellite synthetic aperture radar and Landsat optical images, the former going back to 1992, the latter to 1972. To identify surge-type glaciers, we consider temporal changes in velocity, changes in glacier terminus position, propagation of a surge bulge, presence of looped and/or contoured medial moraines, and extensive crevassing. Other than the nine surge-type glaciers, we identify two that have likely surged, and six that may be surge type. But no glacier surges more than once during the observation period, meaning that the recurrence interval exceeds 42 years. In addition, we examine the evolution of the surface velocities at two surging glaciers with the unprecedented temporal resolution of down to 11 days over ˜7 years. The results show clear seasonal modulations by as much as ˜200% in early winter against those in early summer. This seasonal modulation in surface velocity suggests the presence of surface meltwater that reroutes through the englacial and subglacial drainage systems. Thus, our findings suggest that the hydrological processes originating in the surface meltwater play an important role in maintaining the yearlong active surging phase.

  17. Brief Communication: Twelve-year cyclic surging episodes at Donjek Glacier in Yukon, Canada

    Science.gov (United States)

    Abe, Takahiro; Furuya, Masato; Sakakibara, Daiki

    2016-07-01

    Surge-type glaciers repeat their short active phase and their much longer quiescent phase usually every several decades or longer, but detailed observations of the evolution cycles have been limited to only a few glaciers. Here we report three surging episodes in 1989, 2001, and 2013 at Donjek Glacier in the Yukon, Canada, indicating remarkably regular and short repeat cycles of 12 years. The surging area is limited within the ˜ 20 km section from the terminus, originating in an area where the flow width significantly narrows downstream, suggesting a strong control of the valley constriction on the surge dynamics.

  18. Brief Communication: Twelve-year cyclic surging episode at Donjek Glacier in Yukon, Canada

    Science.gov (United States)

    Abe, T.; Furuya, M.; Sakakibara, D.

    2015-11-01

    Surge-type glaciers repeat their short active phase and much longer quiescent phase usually every several decades or longer, but detailed observations of the evolution cycles have been limited to a few glaciers. Here we report three surging episodes in 1989, 2001, and 2013 at Donjek Glacier in the Yukon, indicating remarkably regular and short repeat cycles of 12 years. The surging area is limited within the ~ 20 km section from the terminus, where the flow width significantly narrows than upstream, suggesting a strong control of the valley constriction on the surge dynamics.

  19. The Anti-surge Capacity of the Surge Arresters for Information System%信息系统避雷器的抗浪涌能力

    Institute of Scientific and Technical Information of China (English)

    谭克勤

    2001-01-01

    The paper describes the basic characteristics about lightning over-voltage, the technology measures of anti-lightning, and the usage and classification of surge arresters. The paper forcus on the Anti-surge capacity of the various surge arresters.%阐述了雷电过电压的基本特性及防雷技术措施,避雷器的用途和分类,重点论述了各种信息系统避雷器的抗浪涌能力。

  20. Discontinuation of rLH two days before hCG may increase the number of oocytes retrieved in IVF

    Directory of Open Access Journals (Sweden)

    Session Donna R

    2010-03-01

    Full Text Available Abstract Background Administration of recombinant luteinizing hormone (rLH in controlled ovarian hyperstimulation may benefit a subpopulation of patients. However, late follicular phase administration of high doses of rLH may also reduce the size of the follicular cohort and promote monofollicular development. Methods To determine if rLH in late follicular development had a negative impact on follicular growth and oocyte yield, IVF patients in our practice who received rFSH and rLH for the entire stimulation were retrospectively compared with those that had the rLH discontinued at least two days prior to hCG trigger. Results The two groups had similar baseline characteristics before stimulation with respect to age, FSH level and antral follicle count. However, the group which had the rLH discontinued at least two days prior to their hCG shot, had a significantly higher number of oocytes retrieved, including a higher number of MII oocytes and number of 2PN embryos. Conclusions When using rLH for controlled ovarian hyperstimulation, administering it from the start of stimulation and stopping it in the late follicular phase, at least two days prior to hCG trigger, may increase oocyte and embryo yield.

  1. Ca(2+)-binding reduces conformational flexibility of RC-LH1 core complex from thermophile Thermochromatium tepidum.

    Science.gov (United States)

    Jakob-Grun, Selma; Radeck, Jara; Braun, Paula

    2012-03-01

    The light-harvesting complex, LH1, of thermophile purple bacteria Thermochromatium tepidum consists of an array of α- and β-polypeptides which assemble the photoactive bacteriochlorophyll and closely interact with the membrane-lipids. In this study, we investigated the effect of calcium and manganese ions on the protein structure and thermostability of the reaction centre (RC)-LH1/lipid complex. The binding of Ca(2+), but not Mn(2+) is shown to shift the LH1 Q ( y ) absorption maximum from ~889 to 915 nm and to significantly raise the thermostability of the RC-LH1 complex. The ATR-FTIR spectra indicate that interaction of Ca(2+) as monitored by the carboxylates' vibration of aspartate residues, but not Mn(2+) induces changes in the α-helix packing arrangement. The reduced rate of (1)H/(2)H exchange of proteins' amide protons shows that the accessibility to (2)H(2)O is significantly lowered in Ca(2+)-substituted RC-LH1/lipid complexes. In particular, exchange with the associated lipid molecules, is significantly retarded. These results suggest that the thermostability of the RC-LH1 complex is raised by the distinct interaction with calcium cations which reduces the RC-LH1/lipid dynamics, particularly, at the membrane-water interface.

  2. Luteinizing Hormone-Induced RUNX1 Regulates the Expression of Genes in Granulosa Cells of Rat Periovulatory Follicles

    Science.gov (United States)

    Jo, Misung; Curry, Thomas E.

    2006-01-01

    The LH surge induces specific transcription factors that regulate the expression of a myriad of genes in periovulatory follicles to bring about ovulation and luteinization. The present study determined 1) the localization of RUNX1, a nuclear transcription factor, 2) regulation of Runx1 mRNA expression, and 3) its potential function in rat ovaries. Up-regulation of mRNA and protein for RUNX1 is detected in preovulatory follicles after human chorionic gonadotropin (hCG) injection in gonadotropin-treated immature rats as well as after the LH surge in cycling animals by in situ hybridization and immunohistochemical and Western blot analyses. The regulation of Runx1 mRNA expression was investigated in vitro using granulosa cells from rat pre-ovulatory ovaries. Treatments with hCG, forskolin, or phorbol 12 myristate 13-acetate stimulated Runx1 mRNA expression. The effects of hCG were reduced by inhibitors of protein kinase A, MAPK kinase, or p38 kinase, indicating that Runx1 expression is regulated by the LH-initiated activation of these signaling mediators. In addition, hCG-induced Runx1 mRNA expression was inhibited by a progesterone receptor antagonist and an epidermal growth factor receptor tyrosine kinase inhibitor, whereas amphiregulin stimulated Runx1 mRNA expression, demonstrating that the expression is mediated by the activation of the progesterone receptor and epidermal growth factor receptor. Finally, knockdown of Runx1 mRNA by small interfering RNA decreased progesterone secretion and reduced levels of mRNA for Cyp11a1, Hapln1, Mt1a, and Rgc32. The hormonally regulated expression of Runx1 in periovulatory follicles, its involvement in progesterone production, and regulation of preovulatory gene expression suggest important roles of RUNX1 in the periovulatory process. PMID:16675540

  3. 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.

  4. Do FSH/LH ratio and gonadal hormone levels predict clinical improvement in postmenopausal schizophrenia women?

    Science.gov (United States)

    González-Rodríguez, Alexandre; Bernardo, Miquel; Penadés, Rafael; Arias, Bárbara; Ruiz Cortés, Victoria; Seeman, Mary V; Catalán, Rosa

    2017-07-12

    Menopause is a process characterized by a decline in estrogen levels and is therefore a period of biological vulnerability for psychotic relapse in women with schizophrenia. Our goal was to correlate not only gonadal hormone levels but also follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels with improvement in specific clinical symptoms. Thirty-seven acutely ill postmenopausal schizophrenia women with a newly initiated, clinically determined change in antipsychotic medication participated in a 12-week prospective observational outcome study. Scales used were the PANSS scale for psychotic symptoms, the PSP for functioning, and CGI for global clinical impression. Circulating FSH, LH, estradiol, progesterone, and testosterone serum levels were determined by chemiluminescent immunoassay. Partial correlational analyses were performed along with a Bonferroni significance correction (p schizophrenia symptom domains, we recommend further investigation of pituitary, adrenal, and gonadal hormone ratios as potential markers of clinical improvement in this population.

  5. THE MOST LUMINOUS SUPERNOVA ASASSN-15LH: SIGNATURE OF A NEWBORN RAPIDLY ROTATING STRANGE QUARK STAR

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Z. G.; Wang, S. Q.; Wang, J. S. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Wang, L. J. [Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Yu, Y. W., E-mail: dzg@nju.edu.cn [Institute of Astrophysics, Central China Normal University, Wuhan 430079 (China)

    2016-02-01

    In this paper we show that the most luminous supernova discovered very recently, ASASSN-15lh, could have been powered by a newborn ultra-strongly magnetized pulsar, which initially rotates near the Kepler limit. We find that if this pulsar is a neutron star, its rotational energy could be quickly lost as a result of gravitational-radiation-driven r-mode instability; if it is a strange quark star (SQS), however, this instability is highly suppressed due to a large bulk viscosity associated with the nonleptonic weak interaction among quarks and thus most of its rotational energy could be extracted to drive ASASSN-15lh. Therefore, we conclude that such an ultra-energetic supernova provides a possible signature for the birth of an SQS.

  6. Regulation of post-Golgi LH3 trafficking is essential for collagen homeostasis

    Science.gov (United States)

    Banushi, Blerida; Forneris, Federico; Straatman-Iwanowska, Anna; Strange, Adam; Lyne, Anne-Marie; Rogerson, Clare; Burden, Jemima J.; Heywood, Wendy E.; Hanley, Joanna; Doykov, Ivan; Straatman, Kornelis R.; Smith, Holly; Bem, Danai; Kriston-Vizi, Janos; Ariceta, Gema; Risteli, Maija; Wang, Chunguang; Ardill, Rosalyn E.; Zaniew, Marcin; Latka-Grot, Julita; Waddington, Simon N.; Howe, S. J.; Ferraro, Francesco; Gjinovci, Asllan; Lawrence, Scott; Marsh, Mark; Girolami, Mark; Bozec, Laurent; Mills, Kevin; Gissen, Paul

    2016-01-01

    Post-translational modifications are necessary for collagen precursor molecules (procollagens) to acquire final shape and function. However, the mechanism and contribution of collagen modifications that occur outside the endoplasmic reticulum and Golgi are not understood. We discovered that VIPAR, with its partner proteins, regulate sorting of lysyl hydroxylase 3 (LH3, also known as PLOD3) into newly identified post-Golgi collagen IV carriers and that VIPAR-dependent sorting is essential for modification of lysines in multiple collagen types. Identification of structural and functional collagen abnormalities in cells and tissues from patients and murine models of the autosomal recessive multisystem disorder Arthrogryposis, Renal dysfunction and Cholestasis syndrome caused by VIPAR and VPS33B deficiencies confirmed our findings. Thus, regulation of post-Golgi LH3 trafficking is essential for collagen homeostasis and for the development and function of multiple organs and tissues. PMID:27435297

  7. Successful treatment of unilateral cryptorchid boys risking infertility with LH-RH analogue

    Directory of Open Access Journals (Sweden)

    Faruk Hadziselimovic

    2008-06-01

    Full Text Available INTRODUCTION: Infertility is the primary concern for boys with uni- or bilateral undescended testes. An early and seemingly successful orchiopexy does not improve fertility in a substantial number of cryptorchid males. We confirmed that LH-RH analogue (LH-RHa treatment induces an increase in and maturation of the germ cells; however, it was uncertain if treatment would improve the chance of fertility later in life. MATERIALS AND METHODS: Thirty unilateral cryptorchid boys, with an average age of 3 years at the time of surgery, were included in the study. Testicular biopsy showed that they had impaired testicular maturation and were therefore at high risk for infertility. Fifteen of the 30 unilateral cryptorchid boys were treated with 10 µg LH-RHa (Buserelin nasal spray, administered on alternate days for a period of 6 months, following orchiopexy. The control group consisted of 15 cryptorchid boys who had been treated by Schoemakers type of orchiopexy, alone. After puberty, the ejaculates of both groups were analyzed. RESULTS: All males in the untreated group were severely oligospermic, with 20% being azoospermic. In contrast, 86% of the treated ex-cryptorchid males had a sperm concentration within the normal range; this was significantly different from the sperm concentration found in the untreated group (p = 0.000008. CONCLUSION: For the first time, we demonstrate that infertility in cryptorchidism can be successfully corrected when suitably treated with a LH-RHa. Sperm parameters normalized following therapy in the majority of cryptorchid males who, untreated, would have remained infertile. This innovative hormonal treatment will have a profound effect on the current recommended surgical treatment of boys with undescended testes.

  8. Space-based LH 2 propellant storage system: subscale ground testing results

    Science.gov (United States)

    Liggett, M. W.

    An orbital cryogenic liquid storage facility will be one of the essential elements of the US Space Program to realize the benefits of space-based cryogenic propulsion vehicles such as NASA's space transfer vehicle (STV) for transporting personnel and scientific packages from a space station in low earth orbit (LEO) to geosynchronous orbit (GEO), the moon and beyond. Long-term thermal control of LH 2 and LO 2 storage cryotanks is a key technical objective for many NASA and SDI programmes. Improved retention using refrigeration, boil-off vapour-cooled shields (VCSs), multilayer superinsulation (MLI) and para-ortho (P-O) hydrogen conversion are the required state-of-the-art techniques. The cryotank system level development testing (CSLDT) programme has supported the development of these technologies. Under the programme, trade studies and analyses were followed by the design and construction of a subscale LH 2 storage facility test article for steady-state and transient thermal tests. A two-stage gaseous helium (GHe) refrigerator was integrated with the test article and used to reduce boil-off and/or decrease the time required between passive test configuration steady-state conditions. The LH 2 tank, mounted in a vacuum chamber, was thermally shielded from the chamber wall by MLI blankets and two VCSs. The VCSs were cooled with either LH 2 boil-off gas (through an optional P-O converter) or refrigerated GHe. The CSLDT test article design, assembly and results from 400 hours of thermal tests are presented along with important conclusions. A comparison of predicted and measured steady-state boil-off rates is provided for 10 test configurations, and the system time constant is addressed. Also presented are some of the unique issues and challenges encountered during these tests that are related to instrumentation and control.

  9. Extreme Supernova Models for the Super-luminous Transient ASASSN-15lh

    Science.gov (United States)

    Chatzopoulos, E.; Wheeler, J. C.; Vinko, J.; Nagy, A. P.; Wiggins, B. K.; Even, W. P.

    2016-09-01

    The recent discovery of the unprecedentedly super-luminous transient ASASSN-15lh (or SN 2015L) with its UV-bright secondary peak challenges all the power-input models that have been proposed for super-luminous supernovae. Here we examine some of the few viable interpretations of ASASSN-15lh in the context of a stellar explosion, involving combinations of one or more power inputs. We model the light curve of ASASSN-15lh with a hybrid model that includes contributions from magnetar spin-down energy and hydrogen-poor circumstellar interaction. We also investigate models of pure circumstellar interaction with a massive hydrogen-deficient shell and discuss the lack of interaction features in the observed spectra. We find that, as a supernova, ASASSN-15lh can be best modeled by the energetic core-collapse of an ˜40 M ⊙ star interacting with a hydrogen-poor shell of ˜20 M ⊙. The circumstellar shell and progenitor mass are consistent with a rapidly rotating pulsational pair-instability supernova progenitor as required for strong interaction following the final supernova explosion. Additional energy injection by a magnetar with an initial period of 1-2 ms and magnetic field of 0.1-1 × 1014 G may supply the excess luminosity required to overcome the deficit in single-component models, but this requires more fine-tuning and extreme parameters for the magnetar, as well as the assumption of efficient conversion of magnetar energy into radiation. We thus favor a single-input model where the reverse shock formed in a strong SN ejecta-circumstellar matter interaction following a very powerful core-collapse SN explosion can supply the luminosity needed to reproduce the late-time UV-bright plateau.

  10. [Cytological changes in hypophysis of immatur rats after administration of anti-LH antibodies (author's transl)].

    Science.gov (United States)

    Perez, R L; Bardia-Deu, R; Monastirsky, R A; Lawzewitsch, I V

    1975-01-01

    In the present work, cytological changes produced in rats' pars distalis were studied by administration of anti-LH antibodies. The anti-LH sera was obtained by active immunization of adult rabbits using bovine LH hormone with Freund's complete adjuvant. Newborn albino Wistar male and female rats were daily and subcutaneously inoculated with 0.1 ml. to 0.8 ml of anti-LH sera from the first 24 hr. on during 5 weeks. For controls, a similar schedule of inoculations with normal rabbit serum was used. At weekly intervals during the treatment, 5 lots of rats were sacrificed and the rest after a recovery period of 95 days. At the end of the 2nd week of immunization, both male and female animals showed degranulated gonadotroph cells in the central part of the pars distalis; at the 3rd week these cells were hypertrophied and presented developed Golgi complex. At the 4th week, the first large vacuoles of "castration" were seen in the gonadotroph cells of male pars distalis, besides in the females the degranulation of gonadotrophs continued. During the last week of treatment, the gonadotrophs of the male animals presented a highly dilated Golgi complex, more "castration-like cells" and numerous mitosis figures. The gonadotrophs of females pars distalis presented degranulation, but not vacuoles. After the recovery period the gonadotrophs of male rats were similar to those of the control hypophisis and did not show castration vacuoles in their cytoplasm. In female rats, the gonadotrophic cells showed "castration-like vacuoles" and a raised number of mitosis cells compared to control pituitaries. The significance of these findings will be discussed.

  11. 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.

  12. Simulations of the L-H transition on experimental advanced superconducting Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Weiland, Jan [Department Applied Physics, Chalmers University of Technology and Euratom-VR Association, S41296 Gothenburg (Sweden)

    2014-12-15

    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{sub 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.

  13. 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.

  14. Testosterone and LH Seric Level Dynamics in Male Rats after Potassium Dichromate Intake (Two Generation Study

    Directory of Open Access Journals (Sweden)

    Jelena Rankov

    2010-05-01

    Full Text Available The aim of this study was the evaluation of potassium dichromate impact on biochemical biomarkers for testicular function (serum testosterone and LH level (two generations experiment. Males and females from F0 generation were exposed to potassium dichromate three months before mating. F1 generation was represented by male pups, resulted from F0 generation, exposed to potassium dichromate in utero, in suckling period (via milk and water and until sexual maturity. All the animals were divided in four groups: three experimental and one control, exposed to Cr VI trough drinking water, as follows E1: 25 ppm (LOAEL; E2: 50 ppm: E3: 75 ppm; control group received tap water without chromium content. The study was performed in compliance with national and international law regarding animal welfare and ethics in animal experiments. In male rats, from F0 and F1 generation, exposure to Cr VI determined: significant decrease of testosterone and significant increase of LH seric level in all experimental groups comparative to control one, indirectly, respectively, directly correlated to exposure level. Comparative to F0 generation, in F1 generation seric testosterone level was lower, significantly only in E1 and E3 groups, and LH seric level was significantly higher.

  15. ASASSN-15lh: A Superluminous Ultraviolet Rebrightening Observed by Swift and Hubble

    CERN Document Server

    Brown, Peter J; Cooke, Jeff; Olaes, Melanie; Quimby, Robert M; Baade, Dietrich; Gehrels, Neil; Hoeflich, Peter; Maund, Justyn; Mould, Jeremy; Patat, Ferdinando; Wang, Lifan; Wheeler, J Craig

    2016-01-01

    We present and discuss ultraviolet (UV) and optical photometry from the Ultraviolet/Optical Telescope (UVOT) and X-ray limits from the X-Ray Telescope on Swift and imaging polarimetry and UV/optical spectroscopy with the Hubble Space Telescope (HST) of ASASSN-15lh. It has been classified as a hydrogen-poor superluminous supernova (SLSN I) more luminous than any other supernova observed. From the polarimetry we determine that the explosion was only mildly asymmetric. We find the flux of ASASSN-15lh to increase strongly into the UV, with a UV luminosity a hundred times greater than the hydrogen-rich, UV-bright SLSN II SN~2008es. A late rebrightening -- most prominent at shorter wavelengths -- is seen about two months after the peak brightness, which by itself is as bright as a superluminous supernova. ASASSN-15lh is not detected in the X-rays in individual observations or when the data are summed into two separate bins for the early phase and the rebrightening. The HST UV spectrum during the rebrightening is do...

  16. [Secondary amenorrhea and LH hypersecretion. An unusual report of a granulosa cell ovarian tumor].

    Science.gov (United States)

    Arteaga, E; Campusano, C; Fernández, C

    1993-04-01

    Granulosa cell ovarian tumors are infrequent. Since they originate from the gonadal stroma, they retain a high secretory potential and some of their clinical manifestations may be secondary to the production of sexual steroids. A 36 year old woman with an ovarian tumor presenting as a secondary amenorrhea is reported. This patient had a positive progesterone test and her hormonal profile showed a maintained LH hypersecretion (> 75 mUl/ml) which, joined to the presence of a hypophyseal microadenoma lead to suspect the presence of a gonadotrophin secreting tumor. The absence of LH response to TRH and its adequate suppression using oral contraceptives discarded this diagnosis. The histopathology of the excised ovarian tumor demonstrated that it is was a granulosa cell tumor. The physiopathological explanation of the case is based on the maintained levels of estrogens produced by the tumor that, through a positive feed-back mechanism similar to that of the polycystic ovary syndrome, produced a tonic LH elevation and GnRH hyper response. After the tumor excision, ovulatory cycles resumed and the patient became pregnant, facts that confirm the postulated hypothesis.

  17. The Unexpected, Long-Lasting, UV Rebrightening of the Super-Luminous Supernova ASASSN-15lh

    CERN Document Server

    Godoy-Rivera, D; Kochanek, C S; Chen, Ping; Dong, Subo; Prieto, J L; Shappee, B J; Jha, S W; Foley, R J; Pan, Y -C; Holoien, T W -S; Thompson, Todd A; Grupe, D; Beacom, J F

    2016-01-01

    ASASSN-15lh is the most luminous supernova (SN) ever discovered (Dong et al. 2016), based on its peak bolometric luminosity. Here we report a UV rebrightening of ASASSN-15lh observed with {\\it Swift} during our follow-up photometric campaign. The rebrightening began at $t \\simeq 90$ days (observer frame) after the primary peak and was followed by a $\\sim 120$-day long plateau in the bolometric luminosity, before starting to fade again at $t\\simeq 210$ days. The SN rebrightened in the {\\it Swift} UV bands by $\\Delta m_{UVW2} \\simeq -1.75$ mag, $\\Delta m_{UVM2} \\simeq -1.25$ mag, and $\\Delta m_{UVW1} \\simeq -0.8$ mag, but did not rebrighten in the optical bands. Throughout its initial decline, subsequent rebrightening, and renewed decline, the spectra of ASASSN-15lh did not show evidence of interactions between the ejecta and circumstellar medium (CSM) such as narrow emission lines. There are hints of weak, broad, transient H$\\alpha$ emission at late times, but the feature could also be an artifact. By fitting ...

  18. Efficiency of superstimulatory protocol P-36 associated with the administration of eCG and LH in Nelore cows.

    Science.gov (United States)

    Oliveira, A C S; Mattos, M C C; Bastos, M R; Trinca, L A; Razza, E M; Satrapa, R A; Sartori, R; Barros, Ciro M

    2014-09-15

    Recent work with P-36 demonstrates that the replacement of the last two doses of Follicle-Stimulating Hormone (FSH) with equine chorionic gonadotropin (eCG) increases embryo yields. However, it is unclear if the positive effect of eCG is related to its FSH-like activity, LH-like activity, or both. This study aimed to verify the replacement of eCG with pLH on the last day of superstimulatory treatment. Twenty-five Nelore cows were allocated to four groups: P-36 (control), P-36/eCG, P-36/LH2, and P-36/LH4. All animals underwent four treatments in a crossover design. The control group cows were superstimulated with decreasing doses of porcine Follicle-Stimulating Hormone (pFSH, 133 mg, im). In the P-36/eCG, P-36/LH2, and P-36/LH4 groups, the last two doses of pFSH were replaced in the former group by two doses of eCG (200 IU each dose, im) and in the latter two groups by two doses of pLH (1 and 2 mg each dose, im), respectively. Donors received fixed-time artificial insemination 12 and 24 hours after pLH. Embryo flushing was performed on D16. Data were analyzed by ANOVA (Proc Mixed, SAS). There was a trend of decreasing ovulation rate when comparing groups LH2 and eCG (P = 0.06). However, there was no significant difference in the mean number of viable embryos among groups P-36 (3.3 ± 0.7), P-36/eCG (4.5 ± 0.5), P-36/LH2 (3.7 ± 0.8), and P-36/LH4 (4.2 ± 1.0). It is concluded that the replacement of eCG by pLH on the last day of superstimulatory treatment can be performed with no significant variation in the production of viable embryos.

  19. Combined beta FSH and beta LH response to TRH in patients with clinically non-functioning pituitary adenomas.

    Science.gov (United States)

    Somjen, D; Tordjman, K; Kohen, F; Baz, M; Razon, N; Ouaknine, G; Stern, N

    1997-05-01

    'Paradoxical' responses of LH, FSH, alpha-subunits and beta LH to TRH have previously been reported in individuals with clinically non-functioning pituitary tumours (NFT). The present study was designed to assess the in vivo and in vitro responses of beta FSH to TRH in NFT. We further examined the possibility that a TRH challenge with combined measurement of beta FSH and beta LH will identify a common anomalous secretory pattern in patients with NFT. Forty patients with NFT underwent a standard TRH test (400 micrograms intravenously). Blood samples for the determination of beta FSH, beta LH, FSH and LH were collected prior to TRH as well as 15, 30, 45, 60 and 90 minutes following injection. Additionally, cultured adenomatous cells from eight to these patients were exposed to TRH in the absence and presence of octreotide and gonadotropin subunits were determined. TRH elicited a marked rise in circulating beta FSH in 29 of 40 individuals and in beta LH in 28 of 36 patients with NFT. In a subgroup of eight individuals whose tumours were harvested during surgery and cultured for 7-21 days, TRH increased beta FSH or beta LH and alpha-subunit release in cultured adenomatous cells in all cases, including tumours from subjects not responding to TRH in vivo. In this subgroup of patients octreotide inhibited basal beta FSH secretion but not basal beta LH secretion both in vivo and in primary cultures of NFT cells. Both the in vivo and in vitro beta FSH, beta LH and alpha-subunit responses to TRH were entirely inhibited by octreotide. In all, 38 of the 40 subjects could be identified by either elevated basal beta FSH or beta LH levels and/or an abnormal rise in either beta FSH or beta LH in response to TRH. The measurement of basal and TRH-stimulated beta-FSH and beta-LH levels identifies an abnormal hormonal secretory pattern in the vast majority (> 90%) of patients with clinically nonfunctioning pituitary tumours.

  20. 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

  1. 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

  2. Zinc Oxide Surge Arresters and HVDC 125kV-upgrade 500kV Converter Stations

    Science.gov (United States)

    Shirakawa, Shingo; Kobayashi, Takayuki; Matsushita, Yoshinao; Sakai, Takehisa; Suzuki, Hironori; Ozaki, Yuzo

    Gapless Metal (Zinc) Oxide Surge Arresters for a.c. systems contribute to the insulation co-ordination based on the suppression of lightning surges and switching surges. These gapless metal oxide surge arresters using ZnO elements are effective to HVDC systems. This paper describes basic characteristics of ZnO (zinc oxide) elements for d.c. systems and applications of gapless surge arresters to HVDC 125kV frequency converters, HVDC 250kV, upgrade HVDC 500kV converter stations, and HVDC 500kV cables of Japan through the experience of developments and applications of gapless metal oxide surge arresters.

  3. 基于LH-OAT的SWMM模型参数敏感性分析%An Analysis of Parameter Sensitivity of SWMM Model Based on LH-OAT Method

    Institute of Scientific and Technical Information of China (English)

    朱嘉祺; 徐向阳; 何爽

    2014-01-01

    为了消除SWMM模型计算过程中的不确定性,明确参数对径流模拟的影响,进行了参数敏感性分析.通过LH-OAT敏感性分析方法,辨析出不同参数在昭通市应用时对径流模拟结果的影响程度,确定对其影响较大的若干敏感参数,为参数的率定提供参考.研究结果表明对径流系数影响最大的参数是入渗衰减系数,对洪峰流量影响最大的参数是不渗透性.提高了SWMM模型在金沙江流域应用的可靠性.

  4. Hybrid simulation of metal oxide surge-arrester thermal behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Huang, L.; Raghuveer, M.R. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Electrical and Computer Engineering

    1996-01-01

    A finite-difference-based technique for simulating the thermal behaviour of a metal oxide surge arrester (MOSA) was described. The improved hybrid thermal modelling technique was claimed to accurately represent heat-transfer modes. Fin theory was used to represent arrester sheds. The proposed model, which relies on simple measurements at the arrester terminals, yields the temporal variation of temperature in a MOSA in both the axial and radial direction. The thermal behaviour of a MOSA under steady-state and transient conditions can be simulated using such a model under different environmental conditions. The accuracy of the modelling technique was demonstrated experimentally by measurements conducted on an arrester. 15 refs., 7 figs.

  5. Designs for surge immunity in critical electronic facilities

    Science.gov (United States)

    Roberts, Edward F., Jr.

    1991-01-01

    In recent years, Federal Aviation Administration (FAA) embarked on a program replacing older tube type electronic equipment with newer solid state equipment. This replacement program dramatically increased the susceptibility of the FAA's facilities to lightning related damages. The proposal is presented of techniques which may be employed to lessen the susceptibility of new FAA electronic facility designs to failures resulting from lightning related surges and transients as well as direct strikes. The general concept espoused is one of a consistent system approach employing both perimeter and internal protection. It compares the technique presently employed to reduce electronic noise with other techniques which reduce noise while lowering susceptibility to lightning related damage. It is anticipated that these techniques will be employed in the design of an Air Traffic Control Tower in a high isokeraunic area. This facility would be subjected to rigorous monitoring over a multi-year period to provide quantitative data hopefully supporting the advantage of this design.

  6. Designs for surge immunity in critical electronic facilities

    Science.gov (United States)

    Roberts, Edward F., Jr.

    1991-08-01

    In recent years, Federal Aviation Administration (FAA) embarked on a program replacing older tube type electronic equipment with newer solid state equipment. This replacement program dramatically increased the susceptibility of the FAA's facilities to lightning related damages. The proposal is presented of techniques which may be employed to lessen the susceptibility of new FAA electronic facility designs to failures resulting from lightning related surges and transients as well as direct strikes. The general concept espoused is one of a consistent system approach employing both perimeter and internal protection. It compares the technique presently employed to reduce electronic noise with other techniques which reduce noise while lowering susceptibility to lightning related damage. It is anticipated that these techniques will be employed in the design of an Air Traffic Control Tower in a high isokeraunic area. This facility would be subjected to rigorous monitoring over a multi-year period to provide quantitative data hopefully supporting the advantage of this design.

  7. SAPS onset timing during substorms and the westward traveling surge

    Science.gov (United States)

    Mishin, Evgeny, V.

    2016-07-01

    We present multispacecraft observations in the magnetosphere and conjugate ionosphere of the onset time of subauroral polarization streams (SAPS) and tens of keV ring current injections on the duskside in three individual substorms. This is probably the first unequivocal determination of the substorm SAPS onset timing. The time lag between the SAPS and substorm onsets is much shorter than the gradient-curvature drift time of ˜10 keV ions in the plasmasphere. It seemingly depends on the propagation time of substorm-injected plasma from the dipolarization onset region to the plasmasphere, as well as on the SAPS position. These observations suggest that fast onset SAPS and ring current injections are causally related to the two-loop system of the westward traveling surge.

  8. Recent Trends of Technology of Zinc-Oxide Surge Arrester for Electric Power System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.S.; Kim, K.U.; Cho, H.G. [Korea Electrotechnology Research Institute (Korea); Park, T.G. [Changwon National University (Korea); Park, S.H. [KEPCO (Korea)

    1999-05-01

    Metal-oxide surge arresters were developed in the late 1970s, and were immediately recognized as significant breakthrough in over-voltage protection of power system. Work was continued throughout the world on the design, development and application of metal-oxide surge arresters. (author). 6 refs., 1 fig., 6 tabs.

  9. Validating the calculated reliability and availability in Dutch storm surge barriers (and other infrastructural works)

    NARCIS (Netherlands)

    Kleijn van Willigen, G.K.; Meerveld, H. van

    2016-01-01

    The reliability and availability of the Dutch storm surge barriers are calculated by probabilistic risk assessment and various underlying risk analysis methods. These calculations, however, focus on the numerical probability of the storm surge barrier functioning adequately, and the implementation o

  10. INCREASED FLEXIBILITY OF TURBO-COMPRESSORS IN NATURAL GAS TRANSMISSION THROUGH DIRECT SURGE CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Robert J. Mckee; Danny M. Deffenbaugh

    2003-12-01

    This annual progress report describes the second year's technical progress in a three-year program. This report summarizes what is known about internal flows as surge precursors in centrifugal compressors and focuses on accessing factors that affect pre-surge detection. An attempt is made in this analysis to identify and quantify factors concerning compressor design and operations that affect the detection of pre-surge conditions. This progress report presents results from recent laboratory tests conducted during the course of this second year. This project is co-funded by the Gas Machinery Research Council (GMRC) and by Siemens Energy and Automation (Siemens). The most recently available measured pre-surge internal flow data is parameterized to help identify factors that affect the indications that a compressor is approaching surge. Theoretical arguments are applied to access the factors that influence surge precursors and surge initiation in different centrifugal compressors. This work is considered a step in accessing the factors that affect the success or limitations of pre-surge detection in natural gas pipeline compressors.

  11. 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.

  12. Extreme storm surges: a comparative study of frequency analysis approaches

    Directory of Open Access Journals (Sweden)

    Y. Hamdi

    2013-11-01

    Full Text Available In France, nuclear facilities were designed to very low probabilities of failure. Nevertheless, exceptional climatic events have given rise to surges much larger than observations (outliers and had clearly illustrated the potential to underestimate the extreme water levels calculated with the current statistical methods. The objective of the present work is to conduct a comparative study of three approaches including the Annual Maxima (AM, the Peaks-Over Threshold (POT and the r-Largest Order Statistics (r-LOS. These methods are illustrated in a real analysis case study. All the data sets were screened for outliers. Non-parametric tests for randomness, homogeneity and stationarity of time series were used. The shape and scale parameters stability plots, the mean excess residual life plot and the stability of the standard errors of return levels were used to select optimal thresholds and r values for the POT and r-LOS method, respectively. The comparison of methods was based on: (i the uncertainty degrees, (ii the adequacy criteria and tests and (iii the visual inspection. It was found that the r-LOS and POT methods have reduced the uncertainty on the distributions parameters and return level estimates and have systematically shown values of the 100 and 500 yr return levels smaller than those estimated with the AM method. Results have also shown that none of the compared methods has allowed a good fitting at the right tail of the distribution in the presence of outliers. As a perspective, the use of historical information was proposed in order to increase the representativity of outliers in data sets. Findings are of practical relevance not only to nuclear energy operators in France, for applications in storm surge hazard analysis and flood management, but also for the optimal planning and design of facilities to withstand extreme environmental conditions, with an appropriate level of risk.

  13. Extreme storm surges: a comparative study of frequency analysis approaches

    Science.gov (United States)

    Hamdi, Y.; Bardet, L.; Duluc, C.-M.; Rebour, V.

    2014-08-01

    In France, nuclear facilities were designed around very low probabilities of failure. Nevertheless, some extreme climatic events have given rise to exceptional observed surges (outliers) much larger than other observations, and have clearly illustrated the potential to underestimate the extreme water levels calculated with the current statistical methods. The objective of the present work is to conduct a comparative study of three approaches to extreme value analysis, including the annual maxima (AM), the peaks-over-threshold (POT) and the r-largest order statistics (r-LOS). These methods are illustrated in a real analysis case study. All data sets were screened for outliers. Non-parametric tests for randomness, homogeneity and stationarity of time series were used. The shape and scale parameter stability plots, the mean excess residual life plot and the stability of the standard errors of return levels were used to select optimal thresholds and r values for the POT and r-LOS method, respectively. The comparison of methods was based on (i) the uncertainty degrees, (ii) the adequacy criteria and tests, and (iii) the visual inspection. It was found that the r-LOS and POT methods have reduced the uncertainty on the distribution parameters and return level estimates and have systematically shown values of the 100 and 500-year return levels smaller than those estimated with the AM method. Results have also shown that none of the compared methods has allowed a good fit at the right tail of the distribution in the presence of outliers. As a perspective, the use of historical information was proposed in order to increase the representativeness of outliers in data sets. Findings are of practical relevance, not only to nuclear energy operators in France, for applications in storm surge hazard analysis and flood management, but also for the optimal planning and design of facilities to withstand extreme environmental conditions, with an appropriate level of risk.

  14. Progesterone (CIDR)-based timed AI protocols using GnRH, porcine LH or estradiol cypionate for dairy heifers: ovarian and endocrine responses and pregnancy rates.

    Science.gov (United States)

    Ambrose, J D; Kastelic, J P; Rajamahendran, R; Aali, M; Dinn, N

    2005-10-15

    The overall objective was to compare the efficacy of GnRH, porcine LH (pLH) and estradiol cypionate (ECP), in a modified Ovsynch/fixed-time AI (FTAI) protocol that included a controlled internal drug [progesterone] release (CIDR) device. In Experiment 1, heifers received a CIDR on Day -10, and PGF (25mg) on Day -3. At CIDR insertion, heifers received 100 microg of GnRH (n=6), 0.5mg of ECP (n=6), 5.0mg of pLH (n=6) or 2 mL of saline (n=7); these treatments were repeated on Day -1, except for ECP, that was repeated on Day -2, concurrent with CIDR-removal. The 5.0 mg pLH was the least effective with a longer interval to ovulation than the other groups combined (102 versus 64 h; PpLH compared to all other groups (4.5 versus 10.3 ng/mL; PpLH (n=6; pLH-low), 25.0 mg pLH (n=6, pLH-high), or 100 microg GnRH (n=5; control). Heifers in the pLH-high group had greater (PpLH treatments did not differ (P>0.10). Area under the curve for LH (ng/32 h) was at least 50% greater (PpLH-treated heifers compared to GnRH-treated heifers (mean, 41.3, 56.3 and 20.3 for pLH-low, pLH-high and GnRH, respectively). Ovulation occurred in 15 of 17 heifers. Progesterone concentrations were higher on Days 9 and 14 in heifers given 25mg of pLH, suggesting enhanced CL function. In Experiment 3, 240 heifers were assigned to CIDR-based Ovsynch/FTAI protocols. The first and second hormonal treatments (with an intervening PGF treatment on Day -3) were GnRH/GnRH (100 microg), ECP/ECP (0.5 mg), pLH/pLH (12.5 mg) or GnRH/ECP, respectively; pregnancy rates were 58.7, 66.1, 45.9 and 48.3%, respectively (ECP/ECP>both pLH/pLH and GnRH/ECP; P

  15. Identifying surging glaciers in the Central Karakoram for improved climate change impact assessment

    Science.gov (United States)

    Paul, Frank; Bolch, Tobias; Mölg, Nico; Rastner, Philipp

    2015-04-01

    Several recent studies have investigated glacier changes in the Karakoram mountain range, a region where glaciers behave differently (mass gain and advancing tongues) compared to most other regions in the world. Attribution of this behaviour to climate change is challenging, as many glaciers in the Karakoram are of surge type and have actively surged in the recent past. The measured changes in length, area, volume or velocity in this region are thus depending on the time-period analysed and include non-climatic components. Hence, a proper analysis of climate change impacts on glaciers in this region requires a separation of the surging from the non-surging glaciers. This is challenging as the former often lack the typical surface characteristics such as looped moraines (e.g. when they are steep and small) and/or they merge (during a surge) with a larger non-surging glacier and create looped moraines on its surface. By analysing time series of satellite images that are available since 1961, the heterogeneous behaviour of glaciers in the Karakoram can be revealed. In this study, we have analysed changes in glacier terminus positions in the Karakoram over different time periods from 1961 to 2014 for several hundred glaciers using Corona KH-4 and KH-4B, Hexagon KH-9, Terra ASTER, and Landsat MSS, TM, ETM+ and OLI satellite data. For the last 15 years, high-speed animations of image time-series reveal details of glacier flow and surge dynamics that are otherwise difficult to detect. For example, several of the larger glaciers with surging tributaries (e.g. Panmah, Sarpo Laggo, Skamri, K2 glacier) are stationary and downwasting despite the mass contributions from the surging glaciers. The analysis of the entire time series reveals a complex pattern of changes through time with retreating, advancing, surging and stationary glaciers that are partly regionally clustered. While most of the non-surging glaciers show only small changes in terminus position (±100 m or less

  16. 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

  17. A novel carboxyl-terminal heptapeptide initiates the regulated secretion of LH from unique sub-domains of the ER.

    Directory of Open Access Journals (Sweden)

    Albina Jablonka-Shariff

    Full Text Available The coordinated secretion of LH and FSH are critical for reproductive functions. After translocation into the endoplasmic reticulum (ER, their biosynthetic routes diverge at a determinative step prior to sorting in the regulated (LH and constitutive (FSH secretion pathways. Recently, we identified a C-terminal heptapeptide sequence, present only in the LHβ subunit, as a critical signal for entry of the LH dimer into the regulated pathway. We showed that an LHβ mutant lacking the heptapeptide (LHβΔT assembled more efficiently with the α subunit than wild-type LHβ subunit, and this LHΔT dimer was secreted constitutively. Thus, an association exists between the presence of the C-terminal heptapeptide and sorting of the LH heterodimer to the regulated pathway. To study how this delayed LHβ subunit assembly is related to the trafficking of LH, we exploited the single subunit transfection model in rat somatotrope-derived GH3 cells with the use of immunofluorescence confocal microscopy. The LHβ subunit showed a distinct immunofluorescent localization as compared to the FSHβ subunit and LHβ mutants. The wild-type LHβ subunit exhibited a perinuclear staining corresponding to the ER/nuclear envelope region. In contrast, the wild-type FSHβ subunit and the mutants LHβΔT and LHβL119A displayed no detectable perinuclear staining; only peripheral ER puncta were observed. Also, no perinuclear fluorescence was detected in cells expressing the LH heterodimer. We propose that the C-terminal heptapeptide is responsible for delayed heterodimer assembly within an ER sub-domain of the nuclear envelope, as an early partitioning event necessary for the entrance of LH into the regulated secretory pathway, whereas FSHβ does not traverse the nuclear envelope region. These data suggest that, at least for LH, the molecular decision to enter the regulated secretory pathway is a pre-Golgi event controlled by the novel C-terminal heptapeptide.

  18. Directional Storm Surge in Enclosed Seas: The Red Sea, the Adriatic, and Venice

    Directory of Open Access Journals (Sweden)

    Carl Drews

    2015-05-01

    Full Text Available Storm surge is dependent on wind direction, with maximum surge heights occurring when strong winds blow onshore. It is less obvious what happens when a port city is situated at the end of a long narrow gulf, like Venice at the northwestern end of the Adriatic Sea. Does the narrow marine approach to the port city limit the dangerous wind direction to a span of only a few degrees? This modeling study shows that the response in surge height to wind direction is a sinusoidal curve for port cities at the end of a long inlet, as well as for cities exposed along a straight coastline. Surge height depends on the cosine of the angle between the wind direction and the major axis of the narrow gulf. There is no special protection from storm surge afforded by a narrow ocean-going approach to a port city.

  19. 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

    Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract C23A-0580 Multi-temporal DEMs (Digital Elevation Models) of glaciers and ice streams have successfully been used for extraction of changes in ice volume over time. In this study, we analysed DEMs of the Brúarjökull glacier forefield (Iceland......) 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...... margin, where the impact of four surges is evident. Thus, the landscape at Brúarjökull is a product of multiple generations of superimposed landforms associated with extensive sediment transport through subglacial deformation....

  20. 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....... These statistics are very sensitive to the assessments of past events, and to future sea level change. The probability of a major storm surge from the Baltic Sea hitting the Copenhagen metropolitan area is officially determined by the Danish Coastal Authority based on tide gauge records. We have a long history......, but with the revised statistics using historic evidence, much larger events can be expected. Further, we assess the very large impact of sea level rise on the storm surge statistics. As an example, according to the official statistics of southern Copenhagen, the flooding of a present day 100 year event...

  1. Multivariate extreme value analysis of storm surges in SCS on peak over threshold method

    Directory of Open Access Journals (Sweden)

    Y. Luo

    2015-11-01

    Full Text Available We use a novel statistical approach-MGPD to analyze the joint probability distribution of storm surge events at two sites and present a warning method for storm surges at two adjacent positions in Beibu Gulf, using the sufficiently long field data on surge levels at two sites. The methodology also develops the procedure of application of MGPD, which includes joint threshold and Monte Carlo simulation, to handle multivariate extreme values analysis. By comparing the simulation result with analytic solution, it is shown that the relative error of the Monte Carlo simulation is less than 8.6 %. By running MGPD model based on long data at Beihai and Dongfang, the simulated potential surge results can be employed in storm surge warnings of Beihai and joint extreme water level predictions of two sites.

  2. Construction and Characterization of B850-Only LH2 Energy Transfer System in Purple Bacteria%紫细菌B800缺失LH2能量传递模型的构建及性质

    Institute of Scientific and Technical Information of China (English)

    李凯; 赵春贵; 岳慧英; 杨素萍; 曲音波; 焦念志

    2015-01-01

    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 incu‐bated in 10 mmo · L -1 Tris‐HCl (pH 8.0) buffer are selectively released from their binding sites of LH2 of Rhodobacter azoto‐formans(A‐LH2)by0.08% (W/V)SDS.B850‐onlyA‐LH2wasconstructedafterremovingfreeBChlmixingwith10% meth‐yl 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 LH 2 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 un‐changed after P‐LH2 was incubated .P‐LH2 αandβsubunits 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 LH 2 .%构建B800缺失L H2对于阐明光合作用中光能传递的分子机制与捕光复合体组装机制具有重要意义。采用吸收光谱、荧光光谱、分子筛层析、超滤和SDS‐PAGE等方法研究了紫细菌两个典型种外周捕光复合体(LH2)约800 nm特征光谱(B800

  3. Cloning and structural and expressional characterization of BcpLH gene preferentially expressed in folding leaf of Chinese cabbage

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Vegetative growth of Chinese cabbage undergoes the four successive stages which are characterized with the definite types of juvenile,rosette,folding and head leaves.From shoot tips of Chinese cabbage at early folding stage,we constructed a cDNA library and screened the differentially expressed cDNA clones using the cDNAs derived from developing folding leaves and rosette leaves as probes.One complete length of cDNA clone is designated as BcpLH.Computer alignment matched BcpLH to the domains of double-stranded RNA binding (DBRM) and the homologous regions were recognized between BcpLH and human and mouse double-stranded RNA-binding protein TRBP.PCR expression analysis shows that during vegetative growth BcpLH gene was expressed preferentially in folding leaves at folding stage.Transcripts of BcpLH gene were increased when plants were sprayed with IAA.It is deduced that BcpLH gene may be related to initiation of folding leaf and leafy head and induced by auxin in the aspect of transcriptional expression.

  4. LH/hCG-Receptor Expression May Have a Negative Prognostic Value in Low-Risk Endometrial Cancer.

    Science.gov (United States)

    Noci, Ivo; Sorbi, Flavia; Mannini, Luca; Projetto, Elisabetta; Pillozzi, Serena; Ghizzoni, Viola; Lottini, Tiziano; Moncini, Daniela; Baroni, Gianna; Mungai, Francesco; Arcangeli, Annarosa; Fambrini, Massimiliano

    2016-01-01

    A 51 year-old woman was diagnosed with endometrial cancer (EC) and underwent surgical staging. Pathological evaluation showed a 2 cm × 1 cm G2 endometrioid EC with a 30% myometrial deep invasion (FIGO Stage 1A). The patient was classified as low risk of recurrence, and no adjuvant treatment was offered. Six months after surgery, the patient developed an early vescico-vaginal recurrence, and chemotherapy treatment was started. Few months later, a subsequent involvement of vaginal wall, ileum, and omentum was detected, and the patient underwent second surgery. LH/hCG-receptor (LH/hCG-R) expression has been previously reported to be associated with an invasive phenotype in EC cells. Moreover, in a preclinical mouse model of EC behaves as a prometastatic molecular device. We analyzed the expression level of LH/hCG-R in cancer specimens collected during surgeries. Molecular and immunohistochemical analyses showed a strong expression of both mRNA and protein for LH/hCG-R in all specimens. LH/hCG-R expression may be assessed together with other clinicopathological parameters in order to better predict the risk of recurrence in low-risk EC patients. Further clinical trials are warranted in order to validate LH/hCG-R as biomarker in EC.

  5. A new dynamical index for classification of cold surge types over East Asia

    Science.gov (United States)

    Park, Tae-Won; Ho, Chang-Hoi; Jeong, Jee-Hoon; Heo, Jin-Woo; Deng, Yi

    2015-11-01

    The cold surges over East Asia can be classified into wave-train type and blocking type according to their dynamic origins. In the present study, two dynamic indices are proposed to objectively identify cold surge types using potential temperature ( θ) on the dynamic tropopause at 2-potential vorticity units (2-PVU) surface. The two indices are designed to represent primary characteristics of the two types of cold surge. The wave-train index ( WI) is defined as a difference of anomalous θ on the 2-PVU surface between the western North Pacific and northeast China, which captures a southward (northward) intrusion of cold (warm) air mass related to the trough-ridge pattern. The blocking index ( BI) is defined as a difference of anomalous θ between the subarctic region and northeast China, which indicates air mass overturning related to a reversal of the usual meridional θ gradient commonly observed in the occurrence of blocking type cold surge. Composite analyses based on the distribution of the WI and BI clearly demonstrate the dynamic evolutions of corresponding cold surge types. The wave-train cold surge is associated with a southeastward expansion of the Siberian High and northerly wind near surface, which is caused by growing baroclinic waves. During the blocking cold surge, a geopotential height dipole indicating the subarctic blocking and deepening of East Asian coastal trough induces a southward expansion of the Siberian High and northeasterly wind. Compared to the wave-train type, the blocking cold surge exhibits a longer duration and stronger intensity. In the new framework of these dynamic indices, we can detect a third type of cold surge when both the wave-train and the blocking occur together. In addition, we can exclude the events that do not have the essential features of the upper tropospheric disturbances or the subarctic anticyclonic circulation, which are responsible for cold surge occurrence, using the new indices.

  6. Global reconstructed daily surge levels from the 20th Century Reanalysis (1871-2010)

    Science.gov (United States)

    Cid, Alba; Camus, Paula; Castanedo, Sonia; Méndez, Fernando J.; Medina, Raúl

    2017-01-01

    Studying the effect of global patterns of wind and pressure gradients on the sea level variation (storm surge) is a key issue in understanding the recent climate change effect on the dynamical state of the ocean. The analysis of the spatial and temporal variability of storm surges from observations is a difficult task to accomplish since observations are not homogeneous in time, scarce in space, and moreover, their temporal coverage is limited. A recent global surge database developed by AVISO (DAC, Dynamic Atmospheric Correction) fulfilled the lack of data in terms of spatial coverage, but not regarding time extent, since it only includes the last two decades (1992-2014). In this work, we use the 20th Century Reanalysis V2 (20CR), which spans the years 1871 to 2010, to statistically reconstruct daily maximum surge levels at a global scale. A multivariate linear regression model is fitted between daily mean ERA-interim sea level pressure fields and daily maximum surge levels from DAC. Following, the statistical model is used to reconstruct daily surges using mean sea level pressure fields from 20CR. The verification of the statistical model shows good agreements between DAC levels and the reconstructed surge levels from the 20CR. The validation of the reconstructed surge with tide gauges, distributed throughout the domain, shows good accuracy both in terms of high correlations and small errors. A time series comparison is also depicted at specific tide gauges for the beginning of the 20th century, showing a high concordance. Therefore, this work provides to the scientific community, a daily database of maximum surge levels; which correspond to an extension of the DAC database, from 1871 to 2010. This database can be used to improve the knowledge on historical storm surge conditions, allowing the study of their temporal and spatial variability.

  7. Spatial distribution of erosion and deposition during a glacier surge: Brúarjökull, Iceland

    Science.gov (United States)

    Korsgaard, Niels J.; Schomacker, Anders; Benediktsson, Ívar Örn; Larsen, Nicolaj K.; Ingólfsson, Ólafur; Kjær, Kurt H.

    2015-12-01

    Time-series of digital elevation models (DEMs) of the forefield of the Brúarjökull surge-type glacier in Iceland were used to quantify the volume of material that was mobilized by the 1963-1964 surge. The DEMs were produced by stereophotogrammetry on aerial photographs from before the surge (1961) and after (1988 and 2003). The analysis was performed on two DEMs of Difference (DoDs), i.e., a 1961-2003 DoD documenting the impact of the surge and a 1988-2003 DoD documenting the post-surge modification of the juvenile surging glacier landsystem. Combined with a digital geomorphological map, the DoDs allow us to quantify the impact of the surge on a landsystem scale down to individual landforms. A total of 34.2 ± 11.3 × 106 m3 of material was mobilized in the 30.7-km2 study area as a result of the most recent surge event. Of these, 17.4 ± 6.6 × 106 m3 of the material were eroded and 16.8 ± 4.7 × 106 m3 were deposited. More than half of the deposited volume was ice-cored landforms. This study demonstrates that although the total mobilized mass volume is high, the net volume gain of ice and sediment deposited as landforms in the forefield caused by the surge is low. Furthermore, deposition of new dead-ice from the 1963-1964 surge constitutes as much as 64% of the volume gain in the forefield. The 1988-2003 DoD is used to quantify the melt-out of this dead-ice and other paraglacial modification of the recently deglaciated forefield of Brúarjökull.

  8. 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

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

    Science.gov (United States)

    Kjaer, K. H.; Schomacker, A.; Korsgaard, N. J.; Benediktsson, I. O.

    2008-12-01

    Multi-temporal DEMs (Digital Elevation Models) of glaciers and ice streams have successfully been used for extraction of changes in ice volume over time. In this study, we analysed DEMs of the Brúarjökull glacier forefield (Iceland) 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. The surge-type glacier Brúarjökull has experienced six surges during the last four centuries; these are the largest surges known to have occurred in Iceland. During the most recent surge in 1963-64, the glacier advanced 8 km over a period of c. 3 months with a maximum ice flow velocity of 5 m/hr, and 700 km3 of ice were moved downglacier. The continued recession of Brúarjökull since the 1963-64 surge reveals a young landscape consisting of widely spaced and elongated bedrock hills interspaced with shallow sedimentary basins. The majority of the forefield is covered with a basal till sheet 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 sequence that was coupled to the glacier. Elevation differences between the terrain surface in 1945 and 2003 confirm this scenario as huge quantities of sediment was eroded, deformed and transported during the last surge event. On the scale of individual landforms, it appears for a drumlin surface that is has been lowered 20 m from 1945-2003. Dead-ice melting can explain roughly 8 m of this lowering. Thus, the drumlin must have experienced 12 m of subglacial erosion during the 1964 surge. The imprint of at least four landform generations is

  10. CFD investigation of thermal and pressurization performance in LH2 tank during discharge

    Science.gov (United States)

    Wang, Lei; Li, Yanzhong; Li, Cui; Zhao, Zhixiang

    2013-10-01

    Predictions of thermal and pressurization performance in a liquid hydrogen (LH2) tank during liquid discharge is of significance to the design and optimization of a rocket pressurization system. In this paper, a computational fluid dynamic (CFD) model is introduced to simulate the pressurized discharge event of LH2 tank. The wall region together with the fluid region is simultaneously considered as the computational domain, and low-Re k-ε model is applied to account for the fluid-wall heat exchange effect. Liquid-vapor phase change effect is also involved in the model. Comparison of the numerical results with existing experimental data suggests that the CFD model has a good adaptability in pressurization computation. Detailed characteristics, such as pressurant gas requirement, pressure altering history, and temperature distribution inside the tank, can be obtained by the model. The difference of pressurant gas, selecting helium or vapor H2, may result in the variations in pressure and temperature histories. Pressurization by vapor H2 supplies a higher pressure and also a temperature rise, which is significant to consider the selection of pressurant gas. The influences of phase change effect and injector structure on pressurization behaviors are also analyzed. The computational results show that liquid-vapor phase change has a slight influence on the pressurization behaviors. Significant pressure decay at the beginning stage of process may occur in the case of no-diffuser injector application since the incoming gas is excessively cooled by cold LH2. The results show that the present CFD model has a good adaptability in the prediction of pressurization behaviors and is a useful tool for the design and optimization of a pressurization system.

  11. Edge radial electric field formation after the L-H transition on JT-60U

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, K.; Matsunaga, G.; Honda, M.; Miyato, N.; Urano, H.; Kamada, Y.; Itoh, K. [Japan Atomic Energy Agency (JAEA), Naka (Japan); Ida, K. [National Institute for Fusion Science (NIFS), Toki (Japan); Collaboration: The JT-60 team

    2014-06-15

    Spatio-temporal measurements of the impurity ion temperature, density, and rotation profiles around the plasma edge region have been made in the JT-60U tokamak, allowing the determination of radial electric field, E{sub r}, with the key dimensionless parameter (poloidal Mach number, U{sub pm)} at the L-H transition in a number of operational regimes. We found that there is variation in the L-H transition in terms of its time-scale; not only ''hard'' type transition with a faster time-scale than that seen in the plasma transport (as represented by an energy confinement time, τ{sub E}) as seen in the many conventional tokamaks, but also ''soft'' one with a slow time-scale (∼τ{sub E}) is possible solution, including a complex multi-stage E{sub r} transition in the later H-phase. The most important point is that the critical condition for the L-H transition predicted by ion-orbit loss model could be applicable only for ''hard'' transition (occurred at U{sub pm} ≥ 1), and not necessary for ''slow'' one (occurred even at U{sub pm} < 1). Characteristics of the turbulent density fluctuation with the frequency range of 100 kHz at the plasma edge region, in addition to a uniform toroidal MHD oscillation (i.e., n = 0), during ELM-free H-phase are also reported. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Effects of dose and duration of continuous GnRH-agonist treatment on induction of estrus in beagle dogs: competing and concurrent up-regulation and down-regulation of LH release.

    Science.gov (United States)

    Concannon, P W; Temple, M; Montanez, A; Newton, L

    2006-10-01

    Dose-response estrus-induction trials were conducted during anestrus in 93 treated and 6 control bitches, a continuous administration of the GnRH-agonist lutrelin with a potency 150 x GnRH, and at six different doses from 0.2 to 4.8 microg/kg/d for 7-14 days in 15 groups of six to eight dogs each in defined stages of natural or pharmacologically determined anestrus. Agonist treatment induced clinically and cytologically normal proestrus (in 89% of cases) within 4.8 +/- 0.2 x days, and resulted in behavioral estrus (71%), spontaneous late-proestrus LH (and FSH) surges, ovulation (59%) and pregnancy (44%) in a dose dependent manner. Outcomes of ovulation and pregnancy in most cases required that the dose be sufficiently large enough to routinely stimulate a large initial increase in LH and FSH (i.e., > or = 0.6 microg/kg/d), and of sufficient duration (i.e., > 7 days) to ensure that supra-basal gonadotropin levels persistedntil no longer needed for spontaneous continuation of an induced proestrus. Success additionally required that the GnRH dose be modest enough (i.e., induction results, including pregnancy rates of 100% in six bitches treated in natural-anestrus bitches, six bitches in which anestrus had been advanced by a luteolytic prostaglandin treatment and in six bitches in which anestrus had been extended by progesterone implants administered for 3 months. Although lutrelin is not commercially available, these results provide guidelines for the development of estrus-inducing protocols with other GnRH-agonists of known biopotencies.

  13. 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.

  14. 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

    postnatally, to mimic the physiological development, would improve testicular growth and fertility potential later in life. DESIGN: Our patient presented with micropenis. Serum hormone concentrations were measured monthly after delivery: LH and testosterone were undetectable, and FSH and inhibin B were below...... to values within normal limits (0.7-1.88 IU/l, 0.17-3.24 IU/l, 121-268 pg/ml and 40-55 pmol/l respectively), whereas serum testosterone remained undetectable. Penile length increased from 1.6 to 2.4 cm and testicular volume, assessed by ultrasound, increased by 170%. No significant adverse events were...

  15. Reconnaissance Level Studies on a Storm Surge Barrier for Flood Risk Reduction in the Houston-Galveston Bay

    NARCIS (Netherlands)

    Jonkman, S.N.; Mooyaart, L.F.; Van Ledden, M.; Stoeten, K.J.; De Vries, P.A.L.; Lendering, K.T.; Van der Toorn, A.; Willems, A.

    2014-01-01

    The Houston - Galveston area is at significant risk from hurricane induced storm surges. This paper summarizes ongoing studies on flood risk reduction for the region. Firstly, based on a simplified probabilistic hurricane surge model , the return periods of surges within the bay have been estimated.

  16. A preliminary study on the intensity of cold wave storm surges of Laizhou Bay

    Science.gov (United States)

    Li, Xue; Dong, Sheng

    2016-12-01

    Dike failure and marine losses are quite prominent in Laizhou Bay during the period of cold wave storm surges because of its open coastline to the north and flat topography. In order to evaluate the intensity of cold wave storm surge, the hindcast of marine elements induced by cold waves in Laizhou Bay from 1985 to 2004 is conducted using a cold wave storm surge-wave coupled model and the joint return period of extreme water level, concomitant wave height, and concomitant wind speed are calculated. A new criterion of cold wave storm surge intensity based on such studies is developed. Considering the frequency of cold wave, this paper introduces a Poisson trivariate compound reconstruction model to calculate the joint return period, which is closer to the reality. By using the newly defined cold wave storm surge intensity, the `cold wave grade' in meteorology can better describe the severity of cold wave storm surges and the warning level is well corresponding to different intensities of cold wave storm surges. Therefore, it provides a proper guidance to marine hydrological analysis, disaster prevention and marine structure design in Laizhou Bay.

  17. Study on the storm surges induced by cold waves in the Northern East China Sea

    Science.gov (United States)

    Mo, Dongxue; Hou, Yijun; Li, Jian; Liu, Yahao

    2016-08-01

    Cold wave, a kind of severe weather system, can bring strong wind and induce significant sea level rise to the Northern East China Sea. Based on CFSR data, the study shows the monthly distributions of invaded days and the spatiotemporal distributions of cold-wave wind direction and wind speed. A three-dimensional numerical model (ROMS) was developed to study storm surges induced by cold waves. The role of wind direction, wind speed, wind duration, extratropical cyclone and tide-surge interaction is investigated by conducting different sensitivity experiments. The results indicate that storm surges mainly happen at the coasts perpendicular to the wind directions. Surge range and time lag are related to the geometry of the basin and the continental shelf. The response of the sea-level fluctuations to cold wave indicates that there is a positive correlation between crests and wind speed, a negative correlation between troughs and wind speed, but no obvious correlations to wind duration. Coupled weather cold waves, which yield a larger range and a multi-peak structure of surges, can be classified according to cold wave tracks and extratropical cyclones. The tide-surge interaction has an obvious and different effect on the magnitudes and phases of storm surges for different tidal stages.

  18. Cold Surge Activity Over the Gulf of Mexico in a Warmer Climate

    Directory of Open Access Journals (Sweden)

    Edgar Perez Perez

    2014-08-01

    Full Text Available Cold surges are a dominant feature of midlatitude tropical interaction. During the North Hemisphere (NH winter, midlatitude waves propagating from the Rocky Mountains into the Gulf of Mexico result in cold surges, also known as Nortes or Tehuantepecers, associated with severe weather over the southern part of Mexico. The magnitude of their intense surface winds, precipitation and drops in surface temperature depends on the characteristics of the midlatitude wave propagating into the tropics. The high spatial resolution (20km X 20km version of the TL959L60-AGC Model of the Meteorological Research Institute of Japan is used to examine changes in cold surge activity under the A1B greenhouse gas emission scenario for the 2080 - 2099 period. The model realistically reproduces the spatial and temporal characteristics of cold surges for the 1980 - 1989 control period. The effect of changes in baroclinicity, static stability and mean flow over North America suggest that in a warmer climate, increased cold surge activity over the Gulf of Mexico would occur. However, these systems would have shorter wavelength (higher phase speeds and shorter lifespans that could reduce the total amount of winter precipitation. The increased frequency of cold surges over the Gulf of Mexico would be a consequence of weaker baroclinicity and static stability in the lower troposphere over the cold surge genesis region, along with more dominant westerly winds, resulting from ENSO-like conditions in the atmospheric circulations over North America.

  19. Winter speed-up of two surging glaciers in West Kunlun Shan, Northwestern Tibet

    Science.gov (United States)

    Yasuda, T.; Furuya, M.

    2015-12-01

    We detected winter speed-up of two surging glaciers in the West Kunlun Shan (WKS), based on satellite Synthetic Aperture Radar (SAR) images since 2007. Surging glacier is a surge-type glacier in the active phase, flowing rapidly and transporting ice masses into the down-glaciers. The WKS is located in northwestern Tibetan Plateau (TP) and is one of the driest and the coldest place around TP. Accumulation and ablation mostly occur in summer season from May to August [Zhang et al., 1989; Maussion et al., 2014]. Zhang et al. (1989) estimated the annual average precipitation and temperature near the equilibrium line altitude (5930 m) is 300 mm and -13.9 deg. C, respectively. Under this sub-polar environment, polythermal glaciers exist in the WKS [Aniya, 2008]. We detected development of two surging flow with unprecedented temporal resolution up to 11 days. The two surging initiated around 2000 and continued by 2015. Surging flow accelerated at least 200 m/year. Moreover, it seasonally fluctuated their flow speed up to 200% in early winter against those in spring to early summer. The observed seasonal modulation in the surface velocities strongly suggests the presence of surface meltwater and subsequent rerouting through englacial and subglacial drainage system under a years-long surging glacier in the sub-polar environment.

  20. Partially Deglycosylated Equine LH Preferentially Activates β-Arrestin-Dependent Signaling at the Follicle-Stimulating Hormone Receptor

    Science.gov (United States)

    Wehbi, Vanessa; Tranchant, Thibaud; Durand, Guillaume; Musnier, Astrid; Decourtye, Jérémy; Piketty, Vincent; Butnev, Vladimir Y.; Bousfield, George R.; Crépieux, Pascale; Maurel, Marie-Christine; Reiter, Eric

    2010-01-01

    Deglycosylated FSH is known to trigger poor Gαs coupling while efficiently binding its receptor. In the present study, we tested the possibility that a deglycosylated equine LH (eLHdg) might be able to selectively activate β-arrestin-dependent signaling. We compared native eLH to an eLH derivative [i.e. truncated eLHβ (Δ121-149) combined with asparagine56-deglycosylated eLHα (eLHdg)] previously reported as an antagonist of cAMP accumulation at the FSH receptor (FSH-R). We confirmed that, when used in conjunction with FSH, eLHdg acted as an antagonist for cAMP accumulation in HEK-293 cells stably expressing the FSH-R. Furthermore, when used alone at concentrations up to 1 nm, eLHdg had no detectable agonistic activity on cAMP accumulation, protein kinase A activity or cAMP-responsive element-dependent transcriptional activity. At higher concentrations, however, a weak agonistic action was observed with eLHdg, whereas eLH led to robust responses whatever the concentration. Both eLH and eLHdg triggered receptor internalization and led to β-arrestin recruitment. Both eLH and eLHdg triggered ERK and ribosomal protein (rp) S6 phosphorylation at 1 nm. The depletion of endogenous β-arrestins had only a partial effect on eLH-induced ERK and rpS6 phosphorylation. In contrast, ERK and rpS6 phosphorylation was completely abolished at all time points in β-arrestin-depleted cells. Together, these results show that eLHdg has the ability to preferentially activate β-arrestin-dependent signaling at the FSH-R. This finding provides a new conceptual and experimental framework to revisit the physiological meaning of gonadotropin structural heterogeneity. Importantly, it also opens a field of possibilities for the development of selective modulators of gonadotropin receptors. PMID:20107152

  1. Partially deglycosylated equine LH preferentially activates beta-arrestin-dependent signaling at the follicle-stimulating hormone receptor.

    Science.gov (United States)

    Wehbi, Vanessa; Tranchant, Thibaud; Durand, Guillaume; Musnier, Astrid; Decourtye, Jérémy; Piketty, Vincent; Butnev, Vladimir Y; Bousfield, George R; Crépieux, Pascale; Maurel, Marie-Christine; Reiter, Eric

    2010-03-01

    Deglycosylated FSH is known to trigger poor Galphas coupling while efficiently binding its receptor. In the present study, we tested the possibility that a deglycosylated equine LH (eLHdg) might be able to selectively activate beta-arrestin-dependent signaling. We compared native eLH to an eLH derivative [i.e. truncated eLHbeta (Delta121-149) combined with asparagine56-deglycosylated eLHalpha (eLHdg)] previously reported as an antagonist of cAMP accumulation at the FSH receptor (FSH-R). We confirmed that, when used in conjunction with FSH, eLHdg acted as an antagonist for cAMP accumulation in HEK-293 cells stably expressing the FSH-R. Furthermore, when used alone at concentrations up to 1 nM, eLHdg had no detectable agonistic activity on cAMP accumulation, protein kinase A activity or cAMP-responsive element-dependent transcriptional activity. At higher concentrations, however, a weak agonistic action was observed with eLHdg, whereas eLH led to robust responses whatever the concentration. Both eLH and eLHdg triggered receptor internalization and led to beta-arrestin recruitment. Both eLH and eLHdg triggered ERK and ribosomal protein (rp) S6 phosphorylation at 1 nM. The depletion of endogenous beta-arrestins had only a partial effect on eLH-induced ERK and rpS6 phosphorylation. In contrast, ERK and rpS6 phosphorylation was completely abolished at all time points in beta-arrestin-depleted cells. Together, these results show that eLHdg has the ability to preferentially activate beta-arrestin-dependent signaling at the FSH-R. This finding provides a new conceptual and experimental framework to revisit the physiological meaning of gonadotropin structural heterogeneity. Importantly, it also opens a field of possibilities for the development of selective modulators of gonadotropin receptors.

  2. Downregulation of LH and FSH receptors after hCG and eCG treatments in the porcine oviduct.

    Science.gov (United States)

    Małysz-Cymborska, I; Andronowska, A

    2016-10-01

    The influence of induction of ovulation and superovulation with eCG and hCG on LH and FSH receptor levels in porcine oviducts on day 3 postcoitum was studied. In experiment I, gilts were assigned into cyclic (control; n = 5) and inseminated (n = 5) groups. In experiment II, there were 3 groups of animals: inseminated (n = 5), induced ovulation/inseminated (750 IU eCG, 500 IU hCG; n = 5) and superovulated/inseminated (1500 IU eCG, 1000 IU hCG; n = 5) gilts. Oviduct tissues were collected 3 d after insemination or PBS infusion. The messenger RNA (mRNA) expression of FSH receptor (FSHR) and luteinizing hormone/chorionic gonadotropin receptor (LH/CGR) was measured by real-time reverse transcription PCR and protein levels using Western blots. Localization of LH/CGR and FSHR-positive cells was studied by immunohistochemical staining. Insemination by itself did not influence mRNA and protein levels of LH/CGR. However, FSHR mRNA expression in the isthmus and ampulla of the oviduct was affected by insemination (P hCG and eCG did not affect LH/CGR and FSHR mRNA expression, either in the isthmus or in the ampulla. Nevertheless, superovulation decreased LH/CGR protein level in the oviductal ampulla (P hCG, especially in high doses, can change LH/CGR and FSHR levels in porcine oviducts. This may in turn alter many signaling pathways, eg, PGs or vascular endothelial growth factor synthesis, and consequently disturb the oviductal environment, with possible detrimental effects on fertilization and/or embryonic development. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Effect of kisspeptin-10, LH and hCG on serum testosterone concentrations in stallions, donkeys and mules.

    Science.gov (United States)

    Akhtar, Rana Waseem; Shah, Syed Aftab Hussain; Qureshi, Irfan Zia

    2017-07-21

    This study was conducted to determine the response of serum testosterone (T) in male equines (stallions, donkeys and mules) after administering intravenous doses of kisspeptin-10 (KP-10), human chorionic gonadotropin (hCG) and luteinizing hormone (LH) and saline as a control. The animals were divided into four groups of three each: Group I, 3 ml of 0.95% saline; Group II, 50 μg KP-10; Group III, 2500 IU hCG and group IV, 400 μg LH. The administration of KP-10 and hCG to stallions resulted in a significant increase in serum T concentration at 240 min; whereas it was significantly higher at 30, 60, 120, and 240 min with LH treatment as compared to pre-dose concentrations. Both KP-10 and hCG significantly elevated the T concentrations in donkeys at 120 and 240 min, respectively; whereas it was significantly higher at 60, 120, and 240 min with LH treatment as compared to pre-dose concentration. Both KP-10 and LH elevated T in donkeys at 240 min as compared to the control and hCG concentrations. After 120 and 240 min, T concentrations in mules were higher (p hCG and LH as compared to the control. In conclusion, the administration of KP-10, hCG and LH elevate the serum T concentration in normal male equines. It is suggested that KP-10 may be useful in situations where an increase in T is desired. Further work is required to determine the effect of KP-10 on T in male equids with reproductive abnormalities before it can be used in clinical situations. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. [The response of free alpha-subunit of glycoprotein hormones to LH-RH administration (author's transl)].

    Science.gov (United States)

    Hamamoto, T; Nishimura, R; Ashitaka, Y; Tojo, S

    1982-05-20

    The responses of immunoreactive free alpha-subunit of glycoprotein hormones to LH-RH administration were studied in normal men and women, and in patients with hypergonadotropic hypogonadism, hypogonadotropic hypogonadism, trophoblastic disease and isolated ectopic alpha-subunit producing tumor. In patients with hypergonadotropic hypergonadism, basal levels of serum alpha-subunit were elevated and the responses to LH-RH were also excessive compared to those of normal men and women. Conversely, in hypogonadotropic hypogonadism, basal levels of alpha-subunit were significantly low and its response to LH-RH was barely detectable. The response of alpha-subunit to constant intravenous infusion of LH-RH (1 microgram/kg/h) was studied in 4 normal men. Both LH and alpha-subunit revealed biphasic patterns of elevation. Its releasing pattern suggests the possibility that two pools of gonadotropin are involved in the production and secretion of alpha-subunit. In patients with trophoblastic disease secreting low levels of hCG (18 mIU/ml), the responses of alpha-subunit as well as pituitary gonadotropin to LH-RH were normal. However, in cases of high concentrations of hCG (1000 mIU/ml), the responses of alpha-subunit and gonadotropin were suppressed. After the administration of LH-RH to a patient with an isolated ectopic alpha-subunit producing tumor, the serum concentration of pituitary gonadotropin increased within the normal range, although that of alpha-subunit did not show a significant change. These results suggest that the production of alpha-subunit by tumors may be autonomous in contrast with a regulatory production in the pituitary.

  5. Slab entrainment and surge dynamics of the 2015 Valleé de la Sionne avalanches

    Science.gov (United States)

    Köhler, Anselm; McElwaine, Jim; Sovilla, Betty

    2016-04-01

    On 3 February 2015 five avalanches were artificially released at the Valleé de la Sionne test site in the west of Switzerland. The dense parts of the avalanches were tracked by the GEODAR Mark 2 radar system at 111 Hz framerate with 0.75 m down slope resolution. The data show that these avalanche contain several internal surges and that the avalanche front is repeatedly overtaken by some of these surges. We show that these surges exist on different scale. While the major surges originates from secondary triggered slab releases and occur all over the avalanche. The minor surges are only found in the energetic part of a well developed powder snow avalanche. The mass of the major surges can be as huge as the initial released mass, this has a dramatic effect on the mass distribution inside the avalanche and effects the front velocity and run out. Furthermore, the secondary released snow slabs are an important entrainment mechanism and up to 50 percent of the mass entered the avalanche via slab entrainment. We analyse the dynamics of the leading edge and the minor surges in more detail using a simple one dimensional model with frictional resistance and quadratic velocity dependent drag. These models fit the data well for the start and middle of avalanche but cannot capture the slowing and overtaking of the minor surge. We find much higher friction coefficients to describe the surging. We propose that this data can only be explained by changes in the snow surface. These effects are not included in current models yet, but the data presented here will enable the development and verification of such models.

  6. The influence of coastal wetlands on hurricane surge in Corpus Christi, TX

    Science.gov (United States)

    Ferreira, C.; Irish, J. L.; Olivera, F.

    2010-12-01

    The State of Texas has historically faced hurricane-related damage episodes, with Ike being the most recent example. It is expected that, in the future, hurricanes will intensify due to climate change causing greater surges, while the attenuating effect of wetlands on storm surges will also be modified due to sea level rise changes in wetland vegetation type and spatial location. Numerical analysis of storm surges is an important instrument to predict and simulate flooding extent and magnitude in coastal areas. Most operational surge models account for the influence of wetlands and other vegetation by momentum loss due to friction at the bottom and by reduction of imposed wind stress. A coupled hydrodynamic model (ADCIRC) and wave model (SWAN) was employed, and wetlands were characterized using Manning’s n, surface canopy, and surface roughness. The wetlands parameters were developed from: 1) the National Land Cover Dataset (NLCD) 1992 and 2001; 2) the National Wetlands Inventory (NWI) 2001. The calibrated coupled model for two historical hurricanes, Bret and Beulah, was used to simulate the storm surge for each scenario. Preliminary results for the sensitivity analyses, for hurricane Bret, comparing the scenarios with parameters developed from NLCD and NWI datasets with four hypothetical scenarios considering very high and low Manning’s n and wind stress (surface canopy) values showed that, for areas inside Nueces Bay, the storm surge high could vary up to four times depending on the parameter selection, for areas inside Corpus Christi Bay, the storm surge high varied around three times and behind the barrier island the storm surge high variation was less than three times. This study is a first step for an evaluation of the impact that sea level rise, climate changed wetlands, wetlands restoration, land use change, and wetlands degradation have on hurricane related surge elevation and extent in the city of Corpus Christi.

  7. A global record of large storm surges and loss of life

    Science.gov (United States)

    Bouwer, Laurens; Jonkman, Sebastiaan

    2017-04-01

    Storm surges can cause very high numbers of loss of life (fatalities) in single events, and these events are expected to increase due to sea-level rise and increasing population in coastal zones. However, compared to fatalities from fresh water flooding, for storm surges these fatality numbers are not consistently recorded, and often neglected in scientific assessments. In order to assess the impacts of major coastal storm surge events at the global level, we have developed a record of these events and associated loss of life. Information was compiled from the EM-DAT database for the period 1900-2013, using the two key categories of "Tropical cyclone" and "Storm surge/coastal flood", complemented with other databases and sources of information, and records of observed surge levels. We find that globally, each year on average about 8,500 people are killed and 1.3 million people are affected by storm surges. The occurrence of very substantial loss of life (>10,000 persons) from single events has decreased over time, which is in contrast with the slight increasing trends in fatalities observed for fresh water flooding. Also, there is a consistent and strong decrease in event mortality, which is the fraction of the people exposed to surges that lose their life, for all global regions, except South-East Asia. Thus, reduction in vulnerability to loss of life over time plays a significant role in storm surge impacts. We also find that for the same coastal surge water level, mortality appears to have decreased over time, showing the robustness of this finding. This quantified decline can be attributed to risk reduction efforts over the last decades, including improved forecasting, early warning and evacuation, but also improved coastal protection. These results have important implications for assessment studies on current and projected future coastal flood risk, as historical mortality fractions may not be valid to assess impacts from future events.

  8. The evolution of a submarine landform record following recent and multiple surges of Tunabreen glacier, Svalbard

    Science.gov (United States)

    Flink, Anne Elina; Noormets, Riko; Kirchner, Nina; Benn, Douglas I.; Luckman, Adrian; Lovell, Harold

    2015-01-01

    This study focuses on the glacial landform record associated with recent surge events of Tunabreen - a calving tidewater glacier in Tempelfjorden, Spitsbergen. Submarine geomorphology and recent terminal fluctuations of Tunabreen's glacier front were studied using high-resolution multibeam-bathymetric data and a range of published and remote-sensing sources, including topographic maps, satellite images and aerial photographs. The retreat moraines in the inner part of Tempelfjorden have been correlated with glacier terminus positions during retreat from the 2004 surge maximum. Glacier surface velocity and ice-front positions derived from high-resolution TerraSAR-X satellite data show ice movements at the glacier front during minor advances of the front in winter when calving is suppressed. This suggests that the moraines have formed annually during quiescent phase winter advances. Tunabreen has experienced three surges since the Little Ice Age (LIA). This is in contrast with most Svalbard surging glaciers which have long quiescent phases and have typically only undergone one or two surges during this time. The landform record in Tempelfjorden is distinguished from previously studied glacier-surge landsystems by four, well-preserved sets of landform assemblages generated by the LIA advance and three subsequent surges, all of which partly modify earlier landform records. Based on the unique landform record in Tempelfjorden, a new conceptual landsystem model for frequently surging glaciers has been put forward improving our understanding of the dynamics of the surging glaciers and, most importantly, how they can be distinguished from the climatically-controlled glaciers in the geological record.

  9. Developing an early warning system for storm surge inundation in the Philippines

    Directory of Open Access Journals (Sweden)

    J. Tablazon

    2014-10-01

    Full Text Available 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

  10. Impact of Low-Level Southerly Surges on Mixed Rossby Gravity Waves over the Central Pacific.

    Science.gov (United States)

    Fukutomi, Y.

    2014-12-01

    This study examines dynamical impacts of lower-tropospheric southerly wind surges originating in midlatitudes of the Southern Hemisphere (SH) on the development of mixed Rossby gravity (MRG) waves over the central Pacific during June-August 1979-2012, through the statistical analysis of the JRA-55 products and NOAA outgoing long wave radiation data. The central Pacific MRG waves are identified by an extended EOF (EEOF) analysis on 2-8-day filtered daily 850-hPa meridional wind anomalies during June-August 1979-2012. Composite analysis based on the leading EEOF time coefficients is able to capture the development of the MRG waves associated with a southerly surge originating in the SH extratropics. As a weak clockwise gyre as a part of an off-equatorial easterly wavetrain moves eastward and southeastward from the off-equatorial eastern Pacific into the equatorial central Pacific, the southerly surge penetrates into the equatorial tropics at around 150W. Then, the clockwise gyre develops into a MRG-type gyre over the central Pacific. A transition from an easterly wave-type gyre into a MRG-type gyre occurs associated with the southerly surge. The southerly surge forms a cross-equatorial flow on the western flank of the MRG-type gyre. The gyre is amplified when the southerly surge reaches the equatorial tropics. At the same time, convection coupled with the MRG-type gyre is enhanced. The southerly surges are originated in the midlatitude South Pacific, and they are induced by synoptic-scale baroclinic disturbances propagating along the SH midlatitude westerly jet. An eddy vorticity budget analysis indicates that the southerly surge plays an important role in spinning up the MRG-type gyre through transient advection of absolute vorticiy. A case study of a MRG-wave event in mid-July 2006 also illustrates development of a MRG wave associated with the southerly surge and an easterly wave-to-MRG wave transition.

  11. Identification of storm surge events over the German Bight from atmospheric reanalysis and climate model data

    Science.gov (United States)

    Befort, D. J.; Fischer, M.; Leckebusch, G. C.; Ulbrich, U.; Ganske, A.; Rosenhagen, G.; Heinrich, H.

    2015-06-01

    A new procedure for the identification of storm surge situations for the German Bight is developed and applied to reanalysis and global climate model data. This method is based on the empirical approach for estimating storm surge heights using information about wind speed and wind direction. Here, we hypothesize that storm surge events are caused by high wind speeds from north-westerly direction in combination with a large-scale wind storm event affecting the North Sea region. The method is calibrated for ERA-40 data, using the data from the storm surge atlas for Cuxhaven. It is shown that using information of both wind speed and direction as well as large-scale wind storm events improves the identification of storm surge events. To estimate possible future changes of potential storm surge events, we apply the new identification approach to an ensemble of three transient climate change simulations performed with the ECHAM5/MPIOM model under A1B greenhouse gas scenario forcing. We find an increase in the total number of potential storm surge events of about 12 % [(2001-2100)-(1901-2000)], mainly based on changes of moderate events. Yearly numbers of storm surge relevant events show high interannual and decadal variability and only one of three simulations shows a statistical significant increase in the yearly number of potential storm surge events between 1900 and 2100. However, no changes in the maximum intensity and duration of all potential events is determined. Extreme value statistic analysis confirms no frequency change of the most severe events.

  12. Identification of storm surge events over the German Bight from atmospheric reanalysis and climate model data

    Directory of Open Access Journals (Sweden)

    D. J. Befort

    2015-06-01

    Full Text Available A new procedure for the identification of storm surge situations for the German Bight is developed and applied to reanalysis and global climate model data. This method is based on the empirical approach for estimating storm surge heights using information about wind speed and wind direction. Here, we hypothesize that storm surge events are caused by high wind speeds from north-westerly direction in combination with a large-scale wind storm event affecting the North Sea region. The method is calibrated for ERA-40 data, using the data from the storm surge atlas for Cuxhaven. It is shown that using information of both wind speed and direction as well as large-scale wind storm events improves the identification of storm surge events. To estimate possible future changes of potential storm surge events, we apply the new identification approach to an ensemble of three transient climate change simulations performed with the ECHAM5/MPIOM model under A1B greenhouse gas scenario forcing. We find an increase in the total number of potential storm surge events of about 12 % [(2001–2100–(1901–2000], mainly based on changes of moderate events. Yearly numbers of storm surge relevant events show high interannual and decadal variability and only one of three simulations shows a statistical significant increase in the yearly number of potential storm surge events between 1900 and 2100. However, no changes in the maximum intensity and duration of all potential events is determined. Extreme value statistic analysis confirms no frequency change of the most severe events.

  13. Surge Capacity of Hospitals in Emergencies and Disasters With a Preparedness Approach: A Systematic Review.

    Science.gov (United States)

    Sheikhbardsiri, Hojjat; Raeisi, Ahmad Reza; Nekoei-Moghadam, Mahmood; Rezaei, Fatemeh

    2017-03-07

    Surge capacity is one of the most important components of hospital preparedness for responding to emergencies and disasters. The ability to provide health and medical care during a sudden increase in the number of patients or victims of disasters is a main concern of hospitals. We aimed to perform a systematic review of hospital surge capacity in emergencies and disasters with a preparedness approach. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The key words "surge," "surge capacity," "preparedness," "hospital emergency department," "hospital," "surge capability," "emergency," "hazard," "disaster," "catastrophe," "crisis," and "tragedy" were used in combination with the Boolean operators OR and AND. The Google Scholar, ISI Web of Science, Science Direct, PubMed, Scopus, Ovid, Pro Quest, and Wiley databases were searched. A total of 1008 articles were extracted and 17 articles were selected for final review of surge capacity based on the objective of the study. Seventeen studies (1 randomized controlled trial, 2 qualitative studies, and 14 cross-sectional studies) investigated the surge capacity of hospitals in emergencies and disasters to evaluate the best evidence to date. The results of selected articles indicated that there are various ways to increase the capacity of hospitals in 4 domains: staff, stuff, structure, and system. Surge capacity is a basic element of disaster preparedness programs. Results of the current study could help health field managers in hospitals to prepare for capacity-building based on surge capacity components to improve and promote hospital preparedness programs. (Disaster Med Public Health Preparedness. 2017;page 1 of 9).

  14. Thermal structure of Svalbard glaciers and implications for thermal switch models of glacier surging

    Science.gov (United States)

    Sevestre, Heïdi; Benn, Douglas I.; Hulton, Nicholas R. J.; Bælum, Karoline

    2015-10-01

    Switches between cold- and warm-based conditions have long been invoked to explain surges of High Arctic glaciers. Here we compile existing and new data on the thermal regime of six glaciers in Svalbard to test the applicability of thermal switch models. Two of the large glaciers of our sample are water terminating while one is land terminating. All three have a well-known surge history. They have a thick basal layer of temperate ice, superimposed by cold ice. A cold terminus forms during quiescence but is mechanically removed by calving on tidewater glaciers. The other three glaciers are relatively small and are either entirely cold or have a diminishing warm core. All three bear evidence of former warm-based thermal regimes and, in two cases, surge-like behavior during the Little Ice Age. In Svalbard, therefore, three types of glaciers have switched from slow to fast flow: (1) small glaciers that underwent thermal cycles during and following the Little Ice Age (switches between cold- and warm-based conditions), (2) large terrestrial glaciers which remain warm based throughout the entire surge cycle but develop cold termini during quiescence, and (3) large tidewater glaciers that remain warm based throughout the surge cycle. Our results demonstrate that thermal switching cannot explain the surges of large glaciers in Svalbard. We apply the concept of enthalpy cycling to the spectrum of surge and surge-like behavior displayed by these glaciers and demonstrate that all Svalbard surge-type glaciers can be understood within a single conceptual framework.

  15. Switching surge overvoltages on a feeding system of a MAGLEV train; Jiki fujoshiki tetsudo no kidenkei ni okeru kaihei surge kaden`atsu

    Energy Technology Data Exchange (ETDEWEB)

    Muragishi, H. [Nippon Yusoki Co. Ltd., Kyoto (Japan); Nakamura, Y.; Muraoka, N.; Ametani, A. [Doshisha Univ., Kyoto (Japan)

    1997-04-20

    Discussions using simulations were given on surge overvoltages and earth fault surge overvoltage associated with operation of a section switchgear in a feeding system of a MAGLEV train. Results of the discussions may be summarized as follows: throw-in surge overvoltage caused by the section switchgear is about 25 kV at maximum on the coil and about 15 kV on the cable sheath. The coil overvoltage increases as the closer to 90 degrees the throw-in phase approaches, and the greater the power supply frequency increases. The cable sheath overvoltage, however, is not affected by these environments. Breaking surge overvoltage caused by the section switchgear reaches 115 kV on the coil and about the same value on the cable sheath when the breaking current is 50 A. Earth fault surge overvoltage due to cable fault is 24 kV at maximum on the coil, while it reaches 32 kV on the cable sheath. The cable sheath overvoltage depends largely on sheath installing conditions. These overvoltages can be suppressed sufficiently lower than insulation levels of each device by installing arresters. 17 refs., 18 figs.

  16. Pharmacokinetics of the Podoviridae phage LH-01 in mice infected with Klebsiella pneumoniae%肺炎克雷伯菌短尾噬菌体LH-01药代动力学研究

    Institute of Scientific and Technical Information of China (English)

    陈松建; 张改; 靳静; 李振江; 王书伟; 李亚辉; 王小亭; 王进; 王中全

    2016-01-01

    目的 探讨噬菌体LH-01在小鼠体内的药代动力学及其影响因素. 方法 观察LH-01在小鼠体内的代谢过程和LH-01中和抗体产生规律.建立小鼠败血症感染模型,使用高剂量和低剂量LH-01进行治疗,观察小鼠健康评分(0~5),同时检测小鼠外周血和主要脏器内活菌数和噬菌体滴度变化规律. 结果 噬菌体LH 01在小鼠体内具有较低的清除率,活性噬菌体可在小鼠体内持续存在数天,10d后完全消失.2周时外周血LH-01中和抗体效价为1∶8,5周时最高为1∶1 024.用高剂量组(1010 PFU/ml)和低价量(104 PFU/ml)的噬菌体LH-01尾静脉注射治疗小鼠败血症,两组组小鼠健康评分最终差异无统计学意义(P>0.05),最终生存率均为100%,而对照组为0%.治疗组小鼠外周血和脏器(肝脏、脾脏和肺脏)中的菌落数显著少于对照组菌落数(P<0.01),尤以脾脏中菌落数减少最显著.LH-01治疗中具有自我放大效应,高剂量和低剂量治疗组小鼠外周血、肝脏和肺脏中的噬菌体滴度与噬菌体对照组相比均显著升高(P<0.01),尤以外周血增加最为明显. 结论 LH-01具有杀菌效率高、自我增殖能力强、活性维持时间长、中和抗体产生晚等良好的药代动力学特性,可试用于多重耐药肺炎克雷伯菌感染的治疗.%Objective To investigate the pharmacokinetics of the phage LH-01 and factors influencing its pharmacokinetics in mice.Methods Changes in the pharmacokinetics of the phage LH-01 were observed in different tissues of mice,and the titer of phage-neutralizing antibodies in serum was also determined.After mice with pneumoniae-induced septicemia were treated with different doses of LH-01 (high and low),the health of those mice was assessed on a scale of 0 to 5 points.The number of phage particles and/or surviving bacterial cells in the organs (PFU/g or CFU/g) and blood (PFU/ml or CFU/ml) were measured.Results Phage LH-01 was still viable in vivo

  17. Time-frequency analysis of the Surge Onset in the Centrifugal Blower

    Directory of Open Access Journals (Sweden)

    Liskiewicz Grzegorz

    2015-09-01

    Full Text Available Time frequency analysis of the surge onset was performed in the centrifugal blower. A pressure signal was registered at the blower inlet, outlet and three locations at the impeller shroud. The time-frequency scalograms were obtained by means of the Continuous Wavelet Transform (CWT. The blower was found to successively operate in four different conditions: stable working condition, inlet recirculation, transient phase and deep surge. Scalograms revealed different spectral structures of aforementioned phases and suggest possible ways of detecting the surge predecessors.

  18. Association between the rate of the morning surge in blood pressure and cardiovascular events and stroke

    Institute of Scientific and Technical Information of China (English)

    LUO Yu; WANG Yan-li; WU Ying-biao; XU Yao; Geoffrey A.Head; Macgrathy Barry; LIANG Yu-lu

    2013-01-01

    Background The exaggerated surge in morning blood pressure (BP) that many patients experience upon awakening may be closely related to target organ damage and may be a predictor of cardiovascular complications.However,no previous studies have evaluated the rate of this surge independently of the evening period.It remains unclear whether the rate of increase experienced during the surge is a significant or independent determinant of cardiovascular events.Methods We randomly selected 340 ambulatory BP monitoring (ABPM) patients.All subjects without type 2 diabetes mellitus were divided into two groups:hypertensive group (n=170) and normotensive group (n=170).We analyzed ambulatory blood pressure recordings using a double logistic curve-fitting procedure to determine whether the magnitude of the surge in BP and heart rate (HR) in the morning is related to the level of BP in hypertensive individuals.We evaluated the association between the rate of the morning surge in systolic BP (SBP) and the incidence of myocardial infarction and stroke in normotensive and hypertensive subjects.Results Comparisons between hypertensive and normotensive subjects showed that the rates of the morning surges in SBP,mean BP (MBP),and diastolic BP (DBP) were greater in the hypertensive group (P <0.05) than in the normotensive group.The rate of morning surge in BP was found to be correlated with the daytime SBP (r=0.236,P <0.01),the difference between the day and night plateau (r=0.249,P <0.01),and the night SBP (r=-0.160,P <0.05),respectively.After controlling for age,sex,and mean systolic pressure within 24 hours (24 h SBP),the rate of morning surge in SBP was closely correlated with daytime SBP (r=0.463,P <0.001),night SBP (r=-0.173,P <0.05),and the difference between the day and night plateau (r=0.267,P <0.001).Logistic regression analysis revealed that the rate of morning surge in SBP was an independent determinant of myocardial infarction (OR=1.266,95% CI=1.153-1.389,P

  19. Photoperiod influences the central effects of ghrelin on food intake, GH and LH secretion in sheep.

    Science.gov (United States)

    Harrison, Joanne L; Miller, David W; Findlay, Patricia A; Adam, Clare L

    2008-01-01

    Ghrelin is a circulating peptide, primarily secreted by the gut, that has reported actions within the hypothalamo-pituitary axis to stimulate food intake, inhibit GnRH/LH secretion and stimulate GH secretion in monogastric species. Here, we examine responses to centrally administered ghrelin in a seasonal ruminant. Estradiol-implanted castrated male sheep with indwelling intracerebroventricular (i.c.v.) cannulae were kept with unrestricted food for 16 weeks in long day photoperiod (LD, 16 h light/day) then 16 weeks in short days (SD, 8 h light/day). In week 16 of each photoperiod they were given a control (saline) i.c.v. injection on day 1 and ghrelin i.c.v. injection on day 2. Mean circulating endogenous plasma ghrelin concentrations showed no diurnal pattern and were similar between the photoperiods. Central ghrelin injection increased voluntary food intake 2-fold in the first hour after administration in LD but not in SD, decreased LH pulse frequency and amplitude in SD but not in LD, and stimulated GH release in both photoperiods, although there was a 1.5-fold larger response in LD. Therefore, central injection of ghrelin to sheep acutely stimulated food intake in LD, suppressed reproductive neuroendocrine output in SD, and stimulated GH secretion irrespective of photoperiod, although more pronounced in LD. These data indicate that photoperiod can influence hypothalamic appetite and reproductive neuroendocrine responses to ghrelin in seasonal species.

  20. Dependence of the L-H power threshold on magnetic balance and heating method in NSTX

    Science.gov (United States)

    Maingi, R.; Biewer, T.; Meyer, H.; Bell, R.; Leblanc, B.; Chang, C. S.

    2007-11-01

    H-mode access is a critical issue for next step devices, such as the International Thermonuclear Experimental Reactor (ITER), which is projected to have a modest heating power margin over the projected L-H power threshold (PLH). The importance of a second X-point in setting the value of PLH has been clarified in recent experiments on several tokamaks. Specifically a reduction of PLH was observed when the magnetic configuration was changed from single null (SN) to double null (DN) in the MAST, NSTX, and ASDEX-Upgrade devices [1]. Motivated by these results, detailed PLH studies on NSTX have compared discharges with neutral beam and rf heating, as a function of drsep. Similar PLH values and edge parameters are observed with the two heating methods in the same magnetic configuration, with PLH ˜ 0.6 MW lowest in DN and increasing to ˜ 1.1 MW and 2-4 MW in lower-SN and upper-SN configurations respectively (ion grad-B-drift towards lower X-point). The evolution of the experimental profiles of parameters in L-mode before the L/H transition will be compared with simulations using the XGC code (C.S. Chang). [1] MEYER, H. et al., Nucl. Fusion 46 (2006) 64.

  1. X-rays from the location of the Bactrian Transient ASASSN-15lh

    CERN Document Server

    Margutti, R; 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

    2016-01-01

    We present the detection of persistent soft X-ray radiation with L_x ~ 10^41-10^42 erg/s 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 time-scales detected at the time of the re-brightening 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 of the ejecta opacity at later times. As a result, UV radiatio...

  2. The Unusual Super-luminous Supernovae SN 2011kl and ASASSN-15lh

    Science.gov (United States)

    Bersten, Melina C.; Benvenuto, Omar G.; Orellana, Mariana; Nomoto, Ken'ichi

    2016-01-01

    Two recently discovered very luminous supernovae (SNe) present stimulating cases to explore the extents of the available theoretical models. SN 2011kl represents the first detection of a supernova explosion associated with an ultra-long duration gamma-ray burst. ASASSN-15lh was even claimed as the most luminous SN ever discovered, challenging the scenarios so far proposed for stellar explosions. Here we use our radiation hydrodynamics code in order to simulate magnetar-powered SNe. To avoid explicitly assuming neutron star properties, we adopt the magnetar luminosity and spin-down timescale as free parameters of the model. We find that the light curve (LC) of SN 2011kl is consistent with a magnetar power source, as previously proposed, but we note that some amount of 56Ni (≳ 0.08{M}⊙ ) is necessary to explain the low contrast between the LC peak and tail. For the case of ASASSN-15lh, we find physically plausible magnetar parameters that reproduce the overall shape of the LC provided the progenitor mass is relatively large (an ejecta mass of ≈ 6{M}⊙ ). The ejecta hydrodynamics of this event is dominated by the magnetar input, while the effect is more moderate for SN 2011kl. We conclude that a magnetar model may be used for the interpretation of these events and that the hydrodynamical modeling is necessary to derive the properties of powerful magnetars and their progenitors.

  3. The Unusual Super-Luminous Supernovae SN 2011kl and ASASSN-15lh

    CERN Document Server

    Bersten, Melina C; Orellana, Mariana; Nomoto, Ken'ichi

    2016-01-01

    Two recently discovered very luminous supernovae (SNe) present stimulating cases to explore the extents of the available theoretical models. SN 2011kl represents the first detection of a supernova explosion associated with an ultra-long duration gamma ray burst. ASASSN-15lh was even claimed as the most luminous SN ever discovered, challenging the scenarios so far proposed for stellar explosions. Here we use our radiation hydrodynamics code in order to simulate magnetar powered SNe. To avoid explicitly assuming neutron star properties we adopt the magnetar luminosity and spin-down timescale as free parameters of the model. We find that the light curve (LC) of SN 2011kl is consistent with a magnetar power source, as previously proposed, but we note that some amount of 56^Ni (> 0.08 M_sun) is necessary to explain the low contrast between the LC peak and tail. For the case of ASASSN-15lh we find physically plausible magnetar parameters that reproduce the overall shape of the LC provided the progenitor mass is rel...

  4. Impact of Resonant Magnetic Perturbations on the L-H Transition on MAST

    CERN Document Server

    Scannell, R; Carr, M; Hawke, J; Henderson, S S; O'Gorman, T; Patel, A; Shaw, A; Thornton, A

    2014-01-01

    The impact of resonant magnetic perturbations (RMPs) on the power required to access H-mode is examined experimentally on MAST. Applying RMP in n=2,3,4 and 6 configurations causes significant delays to the timing of the L-H transition at low applied fields and prevents the transition at high fields. The experiment was primarily performed at RMP fields sufficient to cause moderate increases in ELM frequency, f mitigated/f natural~3. To obtain H-mode with RMPs at this field, an increase of injected beam power is required of at least 50% for n=3 and n=4 RMP and 100% for n=6 RMP. In terms of power threshold, this corresponds to increases of at least 20% for n=3 and n=4 RMPs and 60% for n=6 RMPs. This 'RMP affected' power threshold is found to increase with RMP magnitude above a certain minimum perturbed field, below which there is no impact on the power threshold. Extrapolations from these results indicate large increases in the L-H power threshold will be required for discharges requiring large mitigated ELM fre...

  5. Leptin regulation of inward membrane currents, electrical activity and LH release in isolated bovine gonadotropes.

    Science.gov (United States)

    Domínguez-Mancera, Belisario; Barrientos-Morales, Manuel; Cervantes-Acosta, Patricia; Hernández-Beltrán, Antonio; Rodríguez-Andrade, Araceli; González-Ramírez, Ricardo; Monjaraz, Eduardo; Felix, Ricardo

    2017-09-09

    Leptin, a peptide hormone produced by adipocytes, is recognized as one of the signals involved in the onset of reproductive activity. The leptin receptor has been found in hypothalamic neurons and pituitary gonadotropes, suggesting that the hormone may act at both sites to stimulate the secretion of GnRH and consequently, FSH and LH. In response to a stimulus such as a hypothalamic secretagogue, gonadotropes respond with changes in electrical activity, intracellular Ca(2+) and hormone release. The main aim of this report was to investigate whether leptin promotes a change in the electrical and secretory activities of bovine gonadotropes. After 48 h of treatment with leptin (10 nM) significant changes in the action potential properties were observed in gonadotropes, which included an increase in amplitude, time-to-pike and post-hyperpolarization, as well as a decrease in firing threshold. Likewise, leptin induced a significant (∼1.3-fold) up-regulation of voltage-gated Na(+) channel current density, and a selective increase (∼2.1-fold) in Ca(2+) current density through high voltage-activated channels. Consistent with this, leptin enhanced GnRH-induced secretion of LH measured by ELISA. We suggest that leptin enhances membrane expression of voltage-gated Na(+) and Ca(2+) channels, which results in a modulation of the action potential properties and an increase in hormone release from gonadotropes. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. 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.

  7. Nivmar: a storm surge forecasting system for Spanish waters

    Directory of Open Access Journals (Sweden)

    Enrique Álvarez Fanjul

    2001-07-01

    Full Text Available In this paper, a storm surge prediction system for the Spanish Waters is presented. The system, named Nivmar, is based on the ocean circulation Hamsom model and on the harmonical prediction of tides computed from data measured by the tide gauge network Redmar, managed by Puertos del Estado. Nivmar is executed twice a day, running Hamsom forced by meteorological fields derived from the INM (Instituto Nacional de Meteorología operational application of Hirlam atmospheric model. Data from Redmar tide gauges is used to to forecast the tidal elevations, to validate the system and to perform data assimilation, correcting systematic errors in the mean sea level due to physicals processes that are not included in the ocean model (i. e. steric height. The forecast horizon is 48 hours. In order to validate the system with measured data from Redmar a very stormy 5 months period was selected. Results from this test (November 95 to March 96 are presented. Data from this experiment shown that Nivmar is able to correctly predict sea level in the region. A simple data assimilation scheme for sea level is described and results from its application are studied. Finally, special focus is made in future plans and potential developments and applications of the system.

  8. Southeastern Regional Pediatric Disaster Surge Network: a public health partnership.

    Science.gov (United States)

    Ginter, Peter M; Rucks, Andrew C; Duncan, W Jack; Wingate, Martha S; Beeman, S Kenn; Reeves, Jane; West, Maury A

    2010-01-01

    In the event of a natural or man-made disaster involving large numbers of children, resources in the Southeastern U.S. are extremely limited. This article chronicles the efforts of the Alabama Department of Public Health, the Mississippi State Department of Health, and the South Central Center for Public Health Preparedness in conjunction with more than 40 organizations to develop a voluntary network of health-care providers, public health departments, volunteers, and emergency responders from Alabama, Florida, Louisiana, Mississippi, and Tennessee. The purpose of the Southeastern Regional Pediatric Disaster Surge Network (the Network) is to improve the pediatric preparedness response strategies of public health, emergency response, and pediatric providers in the event of large-scale emergencies or disasters that overwhelm local or state pediatric resources. The planning and development of the Network is proceeding through three general phases--information sharing, mutual goal setting and collective action, and long-term formal linkages. In Phase 1, critical planning tasks to be undertaken in the development of the Network were identified. In Phase 2, the agencies developed a draft operational handbook that served as the basis for a formal memorandum of understanding. In Phase 3, participants will engage in exercises and evaluations that will further identify and work out logistical and operational details.

  9. Effect of ovine luteinizing hormone (oLH) charge isoforms on VEGF and cAMP production.

    Science.gov (United States)

    Montero-Pardo, Arnulfo; Diaz, Daniel; Olivares, Aleida; González-Padilla, Everardo; Murcia, Clara; Gómez-Chavarín, Margarita; Gutiérrez-Ospina, Gabriel; Perera-Marín, Gerardo

    2015-12-01

    Although an increase in VEGF expression and synthesis in association with LH has been established; it is unknown if all LH isoforms act similarly. This study evaluated the production of cAMP and VEGF among LH isoforms in two in vitro bioassays. The LH was obtained from hypophyses and the group of isoforms was isolated by chromatofocusing. cAMP production was assessed using the in vitro bioassay of HEK-293 cells and VEGF production was evaluated in granulosa cells. Immunological activity was measured with a homologous RIA. Immunoactivity and bioactivity for each isoform were compared against a standard, by estimating the IC50 and the EC50. The basic isoforms were more immunoactive than the standard. The neutral and the moderately acidic had an immunological activity similar to the standard. The acidic isoform was the least immunoreactive. cAMP production at the EC50 dose was similar among the basic isoforms, the moderately acidic and the standard; for the neutral and the acidic, the EC50 dose was higher. It was observed that compared with the control, VEGF production at the lowest LH dose was no different in the standard and each isoform. In the intermediate dose, a positive response was caused in the standard and the neutral and basic isoforms. Although the acidic isoform showed a dose-dependent response, it was not significant relative to the control. In conclusion, the basic isoform generated the greatest cAMP and VEGF production, similar to the reference standard, and the acidic the smallest.

  10. Spectral heterogeneity and carotenoid-to-bacteriochlorophyll energy transfer in LH2 light-harvesting complexes from Allochromatium vinosum.

    Science.gov (United States)

    Magdaong, Nikki M; LaFountain, Amy M; Hacking, Kirsty; Niedzwiedzki, Dariusz M; Gibson, George N; Cogdell, Richard J; Frank, Harry A

    2016-02-01

    Photosynthetic organisms produce a vast array of spectral forms of antenna pigment-protein complexes to harvest solar energy and also to adapt to growth under the variable environmental conditions of light intensity, temperature, and nutrient availability. This behavior is exemplified by Allochromatium (Alc.) vinosum, a photosynthetic purple sulfur bacterium that produces different types of LH2 light-harvesting complexes in response to variations in growth conditions. In the present work, three different spectral forms of LH2 from Alc. vinosum, B800-820, B800-840, and B800-850, were isolated, purified, and examined using steady-state absorption and fluorescence spectroscopy, and ultrafast time-resolved absorption spectroscopy. The pigment composition of the LH2 complexes was analyzed by high-performance liquid chromatography, and all were found to contain five carotenoids: lycopene, anhydrorhodovibrin, spirilloxanthin, rhodopin, and rhodovibrin. Spectral reconstructions of the absorption and fluorescence excitation spectra based on the pigment composition revealed significantly more spectral heterogeneity in these systems compared to LH2 complexes isolated from other species of purple bacteria. The data also revealed the individual carotenoid-to-bacteriochlorophyll energy transfer efficiencies which were correlated with the kinetic data from the ultrafast transient absorption spectroscopic experiments. This series of LH2 complexes allows a systematic exploration of the factors that determine the spectral properties of the bound pigments and control the rate and efficiency of carotenoid-to-bacteriochlorophyll energy transfer.

  11. The effect of nutrition on the neural mechanisms potentially involved in melatonin-stimulated LH secretion in female Mediterranean goats.

    Science.gov (United States)

    Zarazaga, Luis A; Celi, Irma; Guzmán, José Luis; Malpaux, Benoît

    2011-12-01

    This research examines which neural mechanisms among the endogenous opioid, dopaminergic, serotonergic and excitatory amino acid systems are involved in the stimulation of LH secretion by melatonin implantation and their modulation by nutritional level. Female goats were distributed to two experimental groups that received either 1.1 (group H; n=24) or 0.7 (group L; n=24) times their nutritional maintenance requirements. Half of each group was implanted with melatonin after a long-day period. Plasma LH concentrations were measured twice per week. The effects of i.v. injections of naloxone, pimozide, cyproheptadine and N-methyl-d,l-aspartate (NMDA) on LH secretion were assessed the day before melatonin implantation and again on days 30 and 45. The functioning of all but the dopaminergic systems was clearly modified by the level of nutrition, melatonin implantation and time elapsed since implantation. Thirty days after implantation, naloxone increased LH concentrations irrespective of the level of nutrition (Pgoats (HM; Pnutritional level and melatonin implantation. Endogenous opioids seem to be most strongly involved in the inhibition of LH secretion on days 30 and 45 after melatonin implantation. However, the serotonergic mechanism appears to be most influenced by nutritional level.

  12. Differential effects of the persistent DDT metabolite methylsulfonyl-DDE in nonstimulated and LH-stimulated neonatal porcine Leydig cells.

    Science.gov (United States)

    Castellanos, Cesilie Granum; Sørvik, Irene Beate; Tanum, Marte Bruu; Verhaegen, Steven; Brandt, Ingvar; Ropstad, Erik

    2013-03-15

    3-Methylsulfonyl-DDE (MeSO₂-DDE) is a potent adrenal toxicant formed from the persistent insecticide DDT. MeSO₂-DDE is widely present in human plasma, milk and fat, and in tissues of marine mammals. In the present study, we investigated endocrine-disrupting properties of MeSO₂-DDE in primary neonatal porcine Leydig cells. Unstimulated and LH-stimulated cells were exposed to MeSO₂-DDE at concentrations ranging from 0.6 to 20 μM for 48 h. Cell viability, hormone secretion and expression of steroidogenesis related genes were recorded. Secretion of testosterone and estradiol was increased in a concentration-dependent fashion in unstimulated Leydig cells, while in LH-stimulated cells, secretion of testosterone, estradiol and progesterone was decreased. The expression of important steroidogenic genes was down-regulated both in unstimulated and LH-stimulated cells. Notably, no significant impairment of cell viability occurred at any exposure except the highest concentration (20 μM) in LH-stimulated cells. This indicated that the effects on hormone secretion and gene expression were not caused by cytotoxicity. We conclude that the adrenal toxicant MeSO₂-DDE disrupts hormone secretion in a complex fashion in neonatal porcine Leydig cells. The different endocrine responses in unstimulated and LH-stimulated cells imply that the endocrine disruptive activity of MeSO₂-DDE is determined by the physiological status of the Leydig cells.

  13. Progesterone (PR), oestrogen (ER-α and ER-β) and oxytocin (OTR) gene expression in the oviduct and uterus of pregnant and non-pregnant bitches.

    Science.gov (United States)

    Derussi, A A P; de Souza, R W A; Volpato, R; Guaitolini, C R F; Ackermann, C L; Taffarel, M O; Cardoso, G S; Dal-Pai-Silva, M; Lopes, M D

    2012-12-01

    The aim was to assess hormone receptor gene expression in the oviduct and uterus during canine pregnancy. Nineteen pregnant bitches divided into four groups were ovariohysterectomized (OVH) at either day 8, 12, 21 or 60 of pregnancy, and five non-pregnant females underwent OVH 12 days after the pre-ovulatory Luteinizant Hormone (LH) surge and served as controls. RT-qPCR for progesterone (PR), oestrogen (ER-α and ER-β) and oxytocin (OTR) receptors was performed on the oviduct and uterine tissue. The mRNA PR expression in the uterus during early stages of pregnancy and the luteal phase was higher than at other times. The mRNA ER-β expression in the oviduct during early pregnancy was less than in non-pregnant bitches. In the uterus, the mRNA ER-β expression was higher in the initial stages of pregnancy. The ER-α expression was higher in the oviduct and uterus in advanced stages of pregnancy. The mRNA OTR expression in the oviduct was lower than in the uterus in control group. The expression of this receptor in oviduct and the uterus was higher in the final stages of pregnancy, when compared with other phases. These data suggested that the serum progesterone concentrations probably exert a direct control on the PR and ER (α and β) expression and indirectly on OTR expression in the bitch oviduct and uterus.

  14. Lightning arrester models enabling highly accurate lightning surge analysis; Koseidona kaminari surge kaiseki wo kano ni suru hiraiki model

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, T. [Chubu Electric Power Co. Inc., Nagoya (Japan); Funabashi, T.; Hagiwara, T.; Watanabe, H. [Meidensha Corp., Tokyo (Japan)

    1998-12-28

    Introduced herein are a dynamic behavior model for lightning arresters designed for power stations and substations and a flashover model for a lightning arresting device designed for transmission, both developed by the author et al. The author et al base their zinc oxide type lightning arrester model on the conventional static V-I characteristics, and supplement them with difference in voltage between static and dynamic characteristics. The model is easily simulated using EMTP (Electromagnetic Transients Program) etc. There is good agreement between the results of calculation performed using this model and actually measured values. Lightning arresting devices for transmission have come into practical use, and their effectiveness is introduced on various occasions. For the proper application of such devices, an analysis model capable of faithfully describing the flashover characteristics of arcing horns installed in great numbers along transmission lines, and of lightning arresting devices for transmission, are required. The author et al have newly developed a flashover model for the devices and uses the model for the analysis of lightning surges. It is found that the actually measured values of discharge characteristics of lightning arresting devices for transmission agree well with the values calculated by use of the model. (NEDO)

  15. Multi-Output Artificial Neural Network for Storm Surge Prediction in North Carolina

    CERN Document Server

    Bezuglov, Anton; Santiago, Reinaldo

    2016-01-01

    During hurricane seasons, emergency managers and other decision makers need accurate and `on-time' information on potential storm surge impacts. Fully dynamical computer models, such as the ADCIRC tide, storm surge, and wind-wave model take several hours to complete a forecast when configured at high spatial resolution. Additionally, statically meaningful ensembles of high-resolution models (needed for uncertainty estimation) cannot easily be computed in near real-time. This paper discusses an artificial neural network model for storm surge prediction in North Carolina. The network model provides fast, real-time storm surge estimates at coastal locations in North Carolina. The paper studies the performance of the neural network model vs. other models on synthetic and real hurricane data.

  16. More Research Shows Big Surge in U.S. Opioid Use, Addictions

    Science.gov (United States)

    ... Research Shows Big Surge in U.S. Opioid Use, Addictions Report from major insurer shows more than 20 ... Health News on Health Disparities Opioid Abuse and Addiction Recent Health News Related MedlinePlus Health Topics Health ...

  17. 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...

  18. 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...

  19. 3D Simulations of a Pyroclastic Surge as an Example of a Compressible Suspension Flow

    National Research Council Canada - National Science Library

    ISHIMINE, Yasuhiro

    2004-01-01

    .... As a conspicuous example of such a flow, we present three-dimensional numerical simulations of a pyroclastic surge, which spreads laterally over the ground surface during some volcanic eruptions...

  20. Lethal thermal impact at periphery of pyroclastic surges: evidences at Pompeii

    National Research Council Canada - National Science Library

    Mastrolorenzo, Giuseppe; Petrone, Pierpaolo; Pappalardo, Lucia; Guarino, Fabio M

    2010-01-01

    The evaluation of mortality of pyroclastic surges and flows (PDCs) produced by explosive eruptions is a major goal in risk assessment and mitigation, particularly in distal reaches of flows that are often heavily urbanized...

  1. Lethal Thermal Impact at Periphery of Pyroclastic Surges: Evidences at Pompeii: e11127

    National Research Council Canada - National Science Library

    Giuseppe Mastrolorenzo; Pierpaolo Petrone; Lucia Pappalardo; Fabio M Guarino

    2010-01-01

      Background The evaluation of mortality of pyroclastic surges and flows (PDCs) produced by explosive eruptions is a major goal in risk assessment and mitigation, particularly in distal reaches of flows that are often heavily urbanized...

  2. 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.

  3. 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.

  4. nowCOAST's Map Service for NOAA NWS NHC Potential Storm Surge Flooding Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Map Information: This nowCOAST map service provides maps depicting the latest official NWS Potential Storm Surge Flooding Map for any significant landfalling...

  5. Global reconstructed daily storm surge levels from the 20th century reanalysis (1871-2010)

    Science.gov (United States)

    Cid, Alba; Camus, Paula; Castanedo, Sonia; Mendez, Fernando; Medina, Raul

    2015-04-01

    The study of global patterns of wind and pressure gradients, and more specifically, their effect on the sea level variation (storm surge), is a key issue in the understanding of recent climate changes. The local effect of storm surges on coastal areas (zones particularly vulnerable to climate variability and changes in sea level), is also of great interest in, for instance, flooding risk assessment. Studying the spatial and temporal variability of storm surges from observations is a difficult task to accomplish since observations are not homogeneous in time and scarce in space, and moreover, their temporal coverage is limited. The development of a global storm surge database (DAC, Dynamic Atmospheric Correction by Aviso, Carrère and Lyard, 2003) fulfils the lack of data in terms of spatial coverage, but not regarding time extent since it only includes last couple of decades (1992-2014). In this work, we propose the use of the 20CR ensemble (Compo et al., 2011) which spans from 1871 to 2010 to statistically reconstruct storm surge at a global scale and for a long period of time. Therefore, the temporal and spatial variability of storm surges can be fully studied and with much less effort than performing a dynamical downscaling. The statistical method chosen to carry out the reconstruction is based on multiple linear regression between an atmospheric predictor and the storm surge level at daily scale (Camus et al., 2014). The linear regression model is calibrated and validated using daily mean sea level pressure fields (and gradients) from the ERA-interim reanalysis and daily maxima surges from DAC. The obtained daily database of maximum daily surges has allowed us to estimate global trends at a centennial scale and analyse the effect of the changing climate on storm surges during the 20th century. Hence, this work improves the knowledge on historical storm-surge conditions and provides helpful information to the community concern on marine climate evolution and

  6. On the 'real' mass loss of some surging glaciers in the central Karakoram

    Science.gov (United States)

    Paul, Frank

    2016-04-01

    Several assessments of the mass changes of surging glaciers in the central Karakoram (and elsewhere) have shown near-zero changes over the typically decadal-long observation periods. This is in line with the theory that during a surge mass from a reservoir area is moved down-glacier to a receiving area with limited overall change. The resulting elevation changes of the glacier surface as determined by differencing DEMs from two points in time show a typical pattern (decreasing at higher, increasing at lower elevations) with a possible strong frontal advance (km scale) of the terminus. However, this is only half of the story as the observed mass gain at lower elevations is ultimately also a loss. This loss can only be determined when it is calculated separately and when sufficiently precise DEMs from the beginning and the end of a surge are available for each individual glacier. As the latter are hard to obtain, this study presents a simplified geomorphometric approach to approximate a potential maximum surge volume for 20 glaciers with a channel-like glacier fore field. By assuming a semi-elliptical cross-section of the channels, simple measurements of their average width, height and length in Google Earth provide the volume. Further glacier-specific parameters are taken from a recently compiled glacier inventory (area, slope) and Google Earth (minimum length and highest/lowest elevations) to obtain characteristics such as elevation ranges and volume. The average annual specific volume loss for each glacier is then determined by dividing the calculated surge volumes by the respective glacier area and the duration of a full surge cycle (obtained in a previous study). Which glacier area (minimum?) and surge duration (only the active phase?) have to be taken for this calculation is likely a matter of debate. With surge distances between about 1 and 5 km and channel widths (heights) between 300 and 700 (50 and 125) m, the surge volumes vary between 15 and 250 (mean 80

  7. Brazilian production development of class 2 polymeric surge arresters for transmission line application

    Energy Technology Data Exchange (ETDEWEB)

    Dellallibera, Adriano A. [Industria Eletromecanica Balestro, Mogi Mirim, SP (Brazil)], E-mail: adrianoad@balestro.com; Andrade, Antonio Donizetti de; Bezerra, Ana Cristina Guara; Duarte, Jose Vicente Pereira; Gois, Paulo Marcio Batista; Markiewicz, Rubens Leopoldo [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil)], Emails: andonize@cemig.com.br, anacris@cemig.com.br, vicente@cemig.com.br, pgois@cemig.com.br, rlmark@cemig.com.br

    2007-07-01

    This paper shows the steeps of Brazilian class 2 ZnO lightning surge arrester development and production, aiming to attend the goal of CEMIG transmission lines performance improvement against lightning discharges action. The description of CEMIG transmission lines performance, before and after the ZnO lightning arresters installation, the necessity of use of ZnO lightning surge arrester, the prototypes manufacture, tests, problems and solutions are presented. (author)

  8. Application and Analysis for Surge Arrester on Lightning Protection of Distribution Network

    Directory of Open Access Journals (Sweden)

    Wang Daxing

    2016-01-01

    Full Text Available In order to effectively reduce lightning stroke outage rate, effect of lightning protection with surge arrester on transmission line has been generally acknowledged relative to other lightning protection measures. This article introduces in such aspects as the working principle of line surge arrester and effect of lightning protection, and also explores application for lightning arrester of distribution network to achieve difference lightning protection and improve the lightning protection performance of distribution network.

  9. An Analysis of Air Force Systems Command’s Industrial Surge Preparedness Planning.

    Science.gov (United States)

    1987-09-01

    have you taken related to suroe preparedness planning? Only three participants stated that they had taken the * basic production management courses AFIT...program phase was/(will) surge planning initially (be) put on contract? a. Suroe not applicable b. Concept Exploration c. Demonstration/Validation d...constantly. (2) Bad answers - Surge is problem in avionics only if suroes requires more test equipment to build upon to suroe rate. 7 esl equipment at least

  10. 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.

  11. Application and Analysis for Surge Arrester on Lightning Protection of Distribution Network

    Directory of Open Access Journals (Sweden)

    Wang Daxing

    2015-01-01

    Full Text Available In order to effectively reduce lightning stroke outage rate, effect of lightning protection with surge arrester on transmission line has been generally acknowledged relative to other lightning protection measures. This article introduces in such aspects as the working principle of line surge arrester and effect of lightning protection, and also explores application for lightning arrester of distribution network to achieve difference lightning protection and improve the lightning protection performance of distribution network.

  12. A time series of TanDEM-X digital elevation models to monitor a glacier surge

    Science.gov (United States)

    Wendt, Anja; Mayer, Christoph; Lambrecht, Astrid; Floricioiu, Dana

    2016-04-01

    Bivachny Glacier, a tributary of the more than 70 km long Fedchenko Glacier in the Pamir Mountains, Central Asia, is a surge-type glacier with three known surges during the 20th century. In 2011, the most recent surge started which, in contrast to the previous ones, evolved down the whole glacier and reached the confluence with Fedchenko Glacier. Spatial and temporal glacier volume changes can be derived from high-resolution digital elevation models (DEMs) based on bistatic InSAR data from the TanDEM-X mission. There are nine DEMs available between 2011 and 2015 covering the entire surge period in time steps from few months up to one year. During the surge, the glacier surface elevation increased by up to 130 m in the lower part of the glacier; and change rates of up to 0.6 m per day were observed. The surface height dataset was complemented with glacier surface velocity information from TerraSAR-X/ TanDEM-X data as well as optical Landsat imagery. While the glacier was practically stagnant in 2000 after the end of the previous surge in the 1990s, the velocity increase started in 2011 in the upper reaches of the ablation area and successively moved downwards and intensified, reaching up to 4.0 m per day. The combination of surface elevation changes and glacier velocities, both of high temporal and spatial resolution, provides the unique opportunity to describe and analyse the evolution of the surge in unprecedented detail. Especially the relation between the mobilization front and the local mass transport provides insight into the surge dynamics.

  13. Singlet-triplet fission of carotenoid excitation in light-harvesting LH2 complexes of purple phototrophic bacteria.

    Science.gov (United States)

    Klenina, I B; Makhneva, Z K; Moskalenko, A A; Gudkov, N D; Bolshakov, M A; Pavlova, E A; Proskuryakov, I I

    2014-03-01

    The current generally accepted structure of light-harvesting LH2 complexes from purple phototrophic bacteria conflicts with the observation of singlet-triplet carotenoid excitation fission in these complexes. In LH2 complexes from the purple bacterium Allochromatium minutissimum, a drop in the efficiency of carotenoid triplet generation is demonstrated, which correlates with the extent of selective photooxidation of bacteriochlorophylls absorbing at ~850 nm. We conclude that singlet-triplet fission of carotenoid excitation proceeds with participation of these excitonically coupled bacteriochlorophylls. In the framework of the proposed mechanism, the contradiction between LH2 structure and photophysical properties of carotenoids is eliminated. The possibility of singlet-triplet excitation fission involving a third mediator molecule was not considered earlier.

  14. Performance of metal oxide gapless surge arresters for HVDC systems

    Energy Technology Data Exchange (ETDEWEB)

    Diseko, N.L.

    1990-09-01

    An examination of the electrical stresses which may be imposed upon metal oxide surge arresters in a dc converter station is undertaken by means of simulation of the dc system and associated ac systems in the time domain using a digital computer program. Detailed models of a dc link are developed for temporary overvoltage stresses and steep front stresses. The most critical stresses for each type of dc station arrester due to converter faults and converter malfunctions are identified. The energy stresses were generally determined to be dependent on the converter control and protection strategies adopted during the faults. The arrester energy stresses for faults on both the line side and valve side busses of the converter transformer were determined to be sensitive to the instant of fault application and the duration of the fault. The arrester stresses for ac bus faults were analyzed in detail to determine their statistical distribution relative to the point on wave at which the fault occurred in each affected phase, and to the instant of fault clearance in each phase. Generally, the highest stresses occur for sequential fault occurrence in the phases compared with simultaneous faults. The studies indicate that the stresses in the arresters in a dc pile experiencing the worst duty depend on the number of arresters represented. Modelling only one arrester of a series-connected group does not provide correct results when the fault condition imposes duty on more than one of the arresters in the group. The study also indicates that the highest stresses do not necessarily occur in the single arrester connected across the valve with the highest prospective overvoltage. Hence the capability to represent all valve arresters within one pole is necessary when determining the most onerous stresses. 11 refs., 79 figs., 28 tabs.

  15. 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)

    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.

  16. 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.

  17. Linkage of Rainfall-Runoff and Hurricane Storm Surge in Galveston Bay

    Science.gov (United States)

    Deitz, R.; Christian, J.; Wright, G.; Fang, N.; Bedient, P.

    2012-12-01

    In conjunction with the SSPEED Center, large rainfall events in the upper Gulf of Mexico are being studied in an effort to help design a surge gate to protect the Houston Ship Channel during hurricane events. The ship channel is the world's second largest petrochemical complex and the Coast Guard estimates that a one-month closure would have a $60 billion dollar impact on the national economy. In this effort, statistical design storms, such as the 24-hour PMP, as well as historical storms, like Hurricane Ike, Hurricane Katrina, and Hurricane Rita, are being simulated in a hydrologic/hydraulic model using radar and rain gauge data. VfloTM, a distributed hydrologic model, is being used to quantify the effect that storm size, intensity, and location has on timing and peak flows in the in the upper drainage area. These hydrographs were input to a hydraulic model with various storm surges from Galveston Bay. Results indicate that there is a double peak phenomenon with flows from the west draining days earlier than flows from the north. With storm surge typically lasting 36-48 hours, this indicates the flows from the west are interacting with the storm surge, whereas flows from the north would arrive once the storm surge is receding. Gate operations were optimized in the model to account for the relative timing of upland runoff and hurricane surge, and to quantify the capability of the gate structure to protect the Ship Channel industry.

  18. 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.

  19. 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.

  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.

    Directory of Open Access Journals (Sweden)

    Edward B Barbier

    Full Text Available 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. 3D Simulation of Storm Surge Disaster Based on Scenario Analysis

    Institute of Scientific and Technical Information of China (English)

    王晓玲; 孙小沛; 张胜利; 孙蕊蕊; 李瑞金; 朱泽彪

    2016-01-01

    The occurrence of storm surge disaster is often accompanied with floodplain, overflow, dike breach and other complex phenomena, while current studies on storm surge flooding are more concentrated on the 1D/2D numerical simulation of single disaster scenario (floodplain, overflow or dike breach), ignoring the composite ef-fects of various phenomena. Therefore, considering the uncertainty in the disaster process of storm surge, scenario analysis was firstly proposed to identify the composite disaster scenario including multiple phenomena by analyzing key driving forces, building scenario matrix and deducing situation logic. Secondly, by combining the advantages of k-ωand k-εmodels in the wall treatment, a shear stress transmission k-ωmodel coupled with VOF was proposed to simulate the 3D flood routing for storm surge disaster. Thirdly, risk degree was introduced to make the risk analysis of storm surge disaster. Finally, based on the scenario analysis, four scenarios with different storm surge intensity (100-year and 200-year frequency) were identified in Tianjin Binhai New Area. Then, 3D numerical simulation and risk map were made for the case.

  3. 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

    2017-05-01

    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.

  4. An ensemble study of extreme North Sea storm surges in a changing climate

    Directory of Open Access Journals (Sweden)

    A. Sterl

    2009-05-01

    Full Text Available The height of storm surges is extremely important for a low-lying country like the Netherlands. By law, part of the coastal defence system has to withstand a water level that on average occurs only once every 10 000 years. The question then arises whether and how climate change affects the heights of extreme storm surges. Published research points to only small changes. However, due to the limited amount of data available results are usually limited to relatively frequent extremes like the annual 99%-ile. We here report on results from a 17-member ensemble of North Sea water levels spaning the period 1950–2100. It was created by forcing a surge model of the North Sea with meteorological output from a state-of-the-art global climate model which has been driven by greenhouse gas emissions following the SRES A1b scenario. The large ensemble size enables us to calculate 10 000 year return water levels with a low statistical uncertainty. We find no statistically significant change in the 10 000 year return values of surge heights along the Dutch during the 21st century. Also a higher sea level resulting from global warming does not impact the height of the storm surges. As a side effect of our simulations we also obtain results on the interplay between surge and tide.

  5. Annual bed statistics give a misleading picture of hospital surge capacity.

    Science.gov (United States)

    DeLia, Derek

    2006-10-01

    I describe how annual hospital surge capacity is affected by within-year variation in patient volume and bed supply. Surge capacity was measured as the percentage and total number of hospital beds that are not occupied by patients. Administrative data were used to calculate these bed statistics for 78 hospitals in New Jersey--statewide and by emergency planning regions--in 2003. Annual bed statistics were compared to more refined calculations for each day of the year. Calculated numbers of empty beds were compared to federal disaster planning benchmarks. Annual bed statistics showed no major limitations on surge capacity. Statewide occupancy rates were well below 80% (ie, more than 20% of beds were empty), and the number of empty beds that were set up and staffed (ie, maintained) was well above federal disaster planning benchmarks. In contrast, daily bed statistics reveal long periods in 2003 when regional and statewide surge capacity was severely strained. Strained capacity was most likely to occur on Tuesdays through Fridays and least likely to occur on weekends. On 212 days, statewide occupancy of maintained beds met or exceeded 85%. This occupancy rate met or exceeded 90% and 95% on 88 and 4 days, respectively. On 288 days, the statewide number of empty maintained beds fell below the federal planning benchmark. Annual bed statistics give a misleading picture of hospital surge capacity. Analysis of surge capacity should account for daily variation in patient volume and within-year variation in bed supply.

  6. The influence of season of lambing and lactation on reproductive activity and plasma LH concentrations in Merino ewes.

    Science.gov (United States)

    Restall, B J; Starr, B G

    1977-03-01

    Groups of Merino ewes which were lactating for 40 days (Group I) or had had their lambs removed at birth (Group II) after lambing in the winter (June) or spring (November) were fed on a high plane of nutrition. Ovarian inspections were carried out at 15 and 30 days after lambing and plasma LH levels were measured at 6-h intervals for 20-30 days. First ovulation was earlier in ewes lambing in the winter (16-6 days, range 11-26) than in the spring (24-7 days, range 15-30) but there was no difference in the number of ewes ovulating. LH levels were higher in winter-lambing ewes (2-79 +/- 3-4 ng/ml) than in those lambing in the spring (1-78 +/- 0-23 ng/ml). LH peaks were usually associated with an ovulation in spring lambing ewes but were not consistently so in the others. More ewes ovulated in Group II (72%) than in Group I (40%) but the mean time of first ovulation was similar. In the winter-lambing ewes the mean daily LH concentration was 2-40 +/- 0-32 ng/ml in Group I and 3-18 +/- 0-31 ng/ml in Group II but there were no differences between the spring-lambing ewes, (I, 1-75 +/- 0-20 ng/ml; II, 1-80 +/- 0-26 ng/ml). There were more elevations in LH levels in Group II ewes (64%) than in Group I ewes (43-8%). After lambing the LH levels increased slowly, indicating a gradual recovery of pituitary function.

  7. Developmental Programming: Insulin Sensitizer Prevents the GnRH-Stimulated LH Hypersecretion in a Sheep Model of PCOS.

    Science.gov (United States)

    Cardoso, Rodolfo C; Burns, Ashleigh; Moeller, Jacob; Skinner, Donal C; Padmanabhan, Vasantha

    2016-12-01

    Prenatal testosterone (T) treatment recapitulates the reproductive and metabolic phenotypes of polycystic ovary syndrome in female sheep. At the neuroendocrine level, prenatal T treatment results in disrupted steroid feedback on gonadotropin release, increased pituitary sensitivity to GnRH, and subsequent LH hypersecretion. Because prenatal T-treated sheep manifest functional hyperandrogenism and hyperinsulinemia, gonadal steroids and/or insulin may play a role in programming and/or maintaining these neuroendocrine defects. Here, we investigated the effects of prenatal and postnatal treatments with an androgen antagonist (flutamide [F]) or an insulin sensitizer (rosiglitazone [R]) on GnRH-stimulated LH secretion in prenatal T-treated sheep. As expected, prenatal T treatment increased the pituitary responsiveness to GnRH leading to LH hypersecretion. Neither prenatal interventions nor postnatal F treatment normalized the GnRH-stimulated LH secretion. Conversely, postnatal R treatment completely normalized the GnRH-stimulated LH secretion. At the tissue level, gestational T increased pituitary LHβ, androgen receptor, and insulin receptor-β, whereas it reduced estrogen receptor (ER)α protein levels. Although postnatal F normalized pituitary androgen receptor and insulin receptor-β, it failed to prevent an increase in LHβ expression. Contrarily, postnatal R treatment restored ERα and partially normalized LHβ pituitary levels. Immunohistochemical findings confirmed changes in pituitary ERα expression to be specific to gonadotropes. In conclusion, these findings indicate that increased pituitary responsiveness to GnRH in prenatal T-treated sheep is likely a function of reduced peripheral insulin sensitivity. Moreover, results suggest that restoration of ERα levels in the pituitary may be one mechanism by which R prevents GnRH-stimulated LH hypersecretion in this sheep model of polycystic ovary syndrome-like phenotype.

  8. Spectroscopic studies of two spectral variants of light-harvesting complex 2 (LH2) from the photosynthetic purple sulfur bacterium Allochromatium vinosum

    National Research Council Canada - National Science Library

    Niedzwiedzki, Dariusz M; Bina, David; Picken, Nichola; Honkanen, Suvi; Blankenship, Robert E; Holten, Dewey; Cogdell, Richard J

    2012-01-01

    Two spectral forms of the peripheral light-harvesting complex (LH2) from the purple sulfur photosynthetic bacterium Allochromatium vinosum were purified and their photophysical properties characterized...

  9. Recombinant LH supplementation to recombinant FSH during the final days of controlled ovarian stimulation for in vitro fertilization. A multicentre, prospective, randomized, controlled trial

    DEFF Research Database (Denmark)

    Nyboeandersen, A; Al Humaidan, Peter Samir Heskjær; Fried, G

    2008-01-01

    either rFSH (Gonal-F) alone (n = 261) or to continue after Day 6 of stimulation with both rFSH (Gonal-F) and rLH (Luveris) (n = 265) from Day 6. The starting dose of rFSH was 150-225 IU/day according to age below or above 35 years. RESULTS: Ongoing pregnancy rate at week 10-12 was 28.7% after rFSH alone...... and 27.2% after rFSH + rLH. This showed no evidence of a difference. Administration of rLH significantly (P....9% low Day 1 LH; 22.1% low Day 6 LH) versus rFSH + rLH (25.0% low Day 1 LH; 28.9% low Day 6 LH). CONCLUSIONS: Supplementing rFSH with daily doses of 75-150 IU of rLH during the second half of the follicular phase showed no evidence of increasing the ongoing pregnancy rates in the general population...

  10. Cold basal conditions during surges control flow of fringing Arctic ice caps in Greenland

    Science.gov (United States)

    Cook, Samuel; Christoffersen, Poul; Todd, Joe; Palmer, Steven

    2017-04-01

    Fringing ice caps separated from larger ice sheets are rarely studied, yet they are an important part of earth's cryosphere, which has become the largest source of global sea-level rise. Understanding marginal ice caps is crucial for being able to predict sea-level change as they are responsible for up to 20% of Greenland's mass loss for 2003-2008. Studies of fringing ice caps can furthermore provide useful insights into processes operating on glaciers that surge. Surging has been the focus of much recent glaciological work, especially with reference to thermal evolution of polythermal glaciers in High Mountain Asia and the High Arctic. This has shown that the classic divide between hydrologically-controlled surges ('hard-bed') in Alaska and thermally-regulated ('soft-bed') surges elsewhere is less stark than previously assumed. Studying marginal ice caps can therefore be valuable in several ways. The largest fringing ice cap in Greenland is Flade Isblink. Previous work has established that this ice cap is showing a range of dynamic behaviour, including subglacial lake drainage and varied patterns of mass-balance change. In particular, a substantial surge, assumed to be caused by a version of the thermally-regulated mechanism, occurred between 1996 and 2000, making the ice cap a useful case study for investigating this process. Here we investigate the surge on Flade Isblink using the open-source, Full-Stokes model Elmer/Ice to invert for basal conditions and englacial temperatures using the adjoint method. We specifically study steady-state conditions representative of the active surge phase in 2000, and the subsequent quiescent phase, using patterns of surface velocity observed in 2000, 2005, 2008 and 2015. Under constant geometry, temperature and geothermal heat, it is shown that surging increases basal freezing rates by over 60% across an area that is twice as large as the area over which the bed freezes in the quiescent phase. The process responsible for this

  11. Plasma transport properties at the L-H transition and high performance phase of JET discharges

    Energy Technology Data Exchange (ETDEWEB)

    Balet, B.; Cordey, J.G.; Erba, M.; Jones, T.T.C.; Lomas, P.J.; Smeulders, P.; Springmann, E.M.; Stubberfield, P.M.; Taroni, A.; Thomsen, K. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Parail, V.V. [Kurchatov Institute, Moscow (Russian Federation)

    1994-07-01

    Numerical analysis are performed which show that both electron and ion thermal diffusivities are reduced by one order of magnitude everywhere, not only in a narrow region near separatrix during the L-H transition. There is no separate H-VH transition on JET, this transition coincides with the cessation of ELMs. In the ELM free phase ion transport in the core is close to its neoclassical value, but probably rises towards plasma edge (however still remaining much less than it was in L-mode). The best agreement with experiment is obtained with the model which simultaneously takes into account both the global reduction of Bohm type anomalous transport in plasma core and formation of temperature pedestal near plasma edge. (authors). 6 refs., 5 figs.

  12. Locality effects on bifurcation paradigm of L-H transition in tokamak plasmas

    Directory of Open Access Journals (Sweden)

    Boonyarit Chatthong

    2015-12-01

    Full Text Available The locality effects on bifurcation paradigm of L-H transition phenomenon in magnetic confinement plasmas are investigated. One dimensional thermal transport equation with both neoclassical and anomalous transports effects included is considered, where a flow shear due to pressure gradient component is included as a transport suppression mechanism. Three different locally driven models for anomalous transport are considered, including a constant transport model, pressure gradient driven transport model, and critical pressure gradient threshold transport model. Local stability analysis shows that the transition occurs at a threshold flux with hysteresis nature only if ratio of anomalous strength over neoclassical transport exceeds a critical value. The depth of the hysteresis loop depends on both neoclassical and anomalous transports, as well as the suppression strength. The reduction of the heat flux required to maintain H-mode can be as low as a factor of two, which is similar to experimental evidence.

  13. NSTX ELM Pacing and L-H Threshold Experiments for ITER

    Science.gov (United States)

    Canik, J. M.; Maingi, R.; Sontag, A. C.; Gerhardt, S. P.; Kaye, S.; Bell, R. E.; Gates, D.; Goldston, R.; Leblanc, B. P.; Menard, J.; Park, J.-K.; Evans, T.; Osborne, T.; Sabbagh, S.; Unterberg, E. A.

    2009-11-01

    We present a summary of recent edge-localized mode (ELM) pacing and L-H power threshold (PLH) experiments performed in NSTX in support of ITER. ELM triggering using 3D magnetic perturbations was used to perform pacing during ELM-free H-modes induced by lithium conditioning, mitigating the impurity accumulation typically observed in these conditions. The waveform of the applied field has been tailored to provide high reliability triggering at frequencies of >60 Hz to reduce the average ELM size. ELM pacing was also performed using vertical position oscillations, with the ELM frequency increased to ˜30 Hz from a natural frequency of ˜15 Hz. PLH is reduced by ˜50% at low triangularity, and also decreased by ˜50% during discharge with thick lithium wall coatings. PLH was observed to increase strongly with plasma current during sustained H-modes. The influence of heating method, non-axisymmetric fields, and magnetic balance on PLH will be presented.

  14. Multilayer-MCTDH approach to the energy transfer dynamics in the LH2 antenna complex

    Science.gov (United States)

    Shibl, Mohamed F.; Schulze, Jan; Al-Marri, Mohammed J.; Kühn, Oliver

    2017-09-01

    The multilayer multiconfiguration time-dependent Hartree method is used to study the coupled exciton-vibrational dynamics in a high-dimensional nonameric model of the LH2 antenna complex of purple bacteria. The exciton-vibrational coupling is parametrized within the Huang-Rhys model according to phonon and intramolecular vibrational modes derived from an experimental bacteriochlorophyll spectral density. In contrast to reduced density matrix approaches, the Schrödinger equation is solved explicitly, giving access to the full wave function. This facilitates an unbiased analysis in terms of the coupled dynamics of excitonic and vibrational degrees of freedom. For the present system, we identify spectator modes for the B800 to B800 transfer and we find a non-additive effect of phonon and intramolecular vibrational modes on the B800 to B850 exciton transfer.

  15. Statistical theory of L-H transition and its implication to threshold database

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Sanae-I. [Kyushu Univ., Research Institute for Applied Mechanics, Kasuga, Fukuoka (Japan); Itoh, Kimitaka; Toda, Shinichiro [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 analyzed in view of describing L-H transitions of toroidal 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. (author)

  16. A theory of lead-time in probabilistic excitation of L/H transition

    Energy Technology Data Exchange (ETDEWEB)

    Toda, Shinichiro; Itoh, Sanae-I.; Yagi, Masatoshi [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics; Itoh, Kimitaka [National Inst. for Fusion Science, Toki, Gifu (Japan); Fukuyama, Atsushi [Kyoto Univ. (Japan). Dept. of Nuclear Engineering

    2000-07-01

    A quantity of a lead-time, t{sub lead}, is newly introduced to examine the probabilistic occurrence of the L/H transition. The lead-time is a time period during which a transition is likely to occur. We show that the lead-time has the statistical distribution as a function of the distance from critical parameter, e.g.|n{sub c} - n{sub c0}|when the density is a key parameter for transition. It has the dependence like t{sub lead} {proportional_to}|n{sub c} - n{sub c0}|{sup 2} if the background noise distribution is given as P (n{sub c}) {proportional_to}|n{sub c} - n{sub c0}|{sup -2}. (author)

  17. Assessment of the LH wave for demo in pulsed and steady state scenario

    Energy Technology Data Exchange (ETDEWEB)

    Cardinali, A.; Barbato, E.; Castaldo, C.; Cesario, R.; Marinucci, M.; Ravera, G. L.; Tuccillo, A. A. [Associazione Euratom-ENEA sulla Fusione, C.R. Frascati, Via Enrico Fermi, 45 00044, Frascati, Roma (Italy); Ceccuzzi, S. [Associazione Euratom-ENEA sulla Fusione, C.R. Frascati, Via Enrico Fermi, 45 00044, Frascati, Roma, Italy and Department of Engineering, Roma Tre University, Via Vito Volterra, 62, 00146, Roma (Italy); Mirizzi, F.; Panaccione, L. [Consorzio CREATE, Universita degli Studi di Napoli Federico II, Via Claudio 21, 80125, Napoli (Italy); Santini, F.; Schettini, G. [Department of Engineering, Roma Tre University, Via Vito Volterra, 62, 00146, Roma (Italy)

    2014-02-12

    The Lower Hybrid Current Drive (LHCD) has been analysed in DEMO tokamak plasma in the 'pulsed and steady state regime' considering two plasma scenarios characterized, respectively, by flat density profile and peaked density profiles. We have obtained LH deposition profiles in cases of neglecting the effect of spectral broadening produced by PI at the edge. By comparing the Power Deposition Profiles for both DEMO scenarios ('flat' and 'peaked'), the SOL of DEMO does not play any role in the absorption of the LH wave. In all cases the deposition is localized inside the separatrix layer r/a≤1. By lowering the parallel wave-number peak of the power spectrum from 1.8 to 1.5, the accessibility condition in both case prevents the power from reaching the deposition layer apart from a small fraction which pertains to the higher n∥ of the power spectrum. The spectrum centred at 1.8 is suggested to be useful in DEMO. More realistically, as supported by available data of LHCD in a wide range of operating densities, the effect of parametric decay instability (PDI) can produce a spectral broadening which should be included in the simulations. Further studies would be necessary for assessing the temperature profiles in the SOL at reactor-graded conditions. This is because, if the SOL temperature is at least of the order of 50 to 100 eV, the effect of PDI broads the spectrum up to n∥≤10, and the deposition profile is slightly wider but not much shifted outwards.

  18. 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.

  19. 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

    2015-02-01

    Full Text Available Super Typhoon Haiyan entered the Philippine Area of Responsibility (PAR 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, the flagship disaster mitigation program of the Department of Science and Technology (DOST, 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. One product of this study is a list of the 30 most vulnerable coastal areas that can be used as 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.

  20. Simulated storm surge effects on freshwater coastal wetland soil porewater salinity and extractable ammonium levels: Implications for marsh recovery after storm surge

    Science.gov (United States)

    McKee, M.; White, J. R.; Putnam-Duhon, L. A.

    2016-11-01

    Coastal wetland systems experience both short-term changes in salinity, such as those caused by wind-driven tides and storm surge, and long-term shifts caused by sea level rise. Salinity increases associated with storm surge are known to have significant effects on soil porewater chemistry, but there is little research on the effect of flooding length on salt penetration depth into coastal marsh soils. A simulated storm surge was imposed on intact soil columns collected from a non-vegetated mudflat and a vegetated marsh site in the Wax Lake Delta, LA. Triplicate intact cores were continuously exposed to a 35 salinity water column (practical salinity scale) for 1, 2, and 4 weeks and destructively sampled in order to measure porewater salinity and extractable NH4sbnd N at two cm depth intervals. Salinity was significantly higher in the top 8 cm for both the marsh and mudflat cores after one week of flooding. After four weeks of flooding, salinity was significantly higher in marsh and mudflat cores compared to the control (no salinity) cores throughout the profile for both sites. Extractable ammonium levels increased significantly in the marsh cores throughout the experiment, but there was only a marginally (p coastal marsh soil in just one week. This vertical intrusion of salt can potentially negatively impact macrophytes and associated microbial communities for significantly longer term post-storm surge.

  1. Twelve-year cyclic surging episode at Donjek Glacier in Yukon, Canada

    Science.gov (United States)

    Furuya, M.; Abe, T.; Sakakibara, D.

    2015-12-01

    Surge-type glaciers exhibit several-fold to orders-of-magnitude speed-up during the short active phase, resulting in km-scale terminus advance. Although there are many surge-type glaciers near the border of Alaska and the Yukon, the generation mechanisms remain uncertain because of limited and few continuous observations. To better understand the surge dynamics and predict the next event, it is essential to examine the entire surge cycles. Here we use Landsat optical imageries to reveal the long-term evolutions, and report three surging episodes at Donjek Glacier in Yukon, Canada. Using the Landsat images, we found three surging events in 1989, 2001, and 2013. In the 2001 event, the surface speed significantly increased by up to 4.5 m/d; during the quiescent phases it was ~0.5 m/d at the terminus. While the duration of active phase is about 4~5 and 2~3 year in the 2001 and 2013 events, the period in the 1989 event is unclear because of the lack of high temporal resolution data. Remarkably, the surging area is limited to the ~20-km section from the terminus instead of the entire glacier. Moreover, we examined the terminus area changes from 1975 to 2014. Although the area has been secularly decreasing probably due to the tread of global warming, it has also revealed four significant fluctuations during the nearly forty years. Comparing the speed and the area changes, the three speed-up events correspond to the terminus area fluctuations with a few time lags. It turns out that the surge event has been quite regularly repeating every twelve years. Although the behavior is rather similar to that in Svalbard glaciers in terms of maximum speed and unclear initiation season, the recurrence interval is much shorter than other nearby surges. Considering that the surge events seem to have initiated around significantly narrower area than upstream, the strong valley constriction may control the regularity as well as the twelve-year recurrence time.

  2. The eSurge-Venice project: altimeter and scatterometer satellite data to improve the storm surge forecasting in the city of Venice

    Science.gov (United States)

    Zecchetto, Stefano; De Biasio, Francesco; Umgiesser, Georg; Bajo, Marco; Vignudelli, Stefano; Papa, Alvise; Donlon, Craig; Bellafiore, Debora

    2013-04-01

    On the framework of the Data User Element (DUE) program, the European Space Agency is funding a project to use altimeter Total Water Level Envelope (TWLE) and scatterometer wind data to improve the storm surge forecasting in the Adriatic Sea and in the city of Venice. The project will: a) Select a number of Storm Surge Events occurred in the Venice lagoon in the period 1999-present day b) Provide the available satellite Earth Observation (EO) data related to the Storm Surge Events, mainly satellite winds and altimeter data, as well as all the available in-situ data and model forecasts c) Provide a demonstration Near Real Time service of EO data products and services in support of operational and experimental forecasting and warning services d) Run a number of re-analysis cases, both for historical and contemporary storm surge events, to demonstrate the usefulness of EO data The re-analysis experiments, based on hindcasts performed by the finite element 2-D oceanographic model SHYFEM (https://sites.google.com/site/shyfem/), will 1. use different forcing wind fields (calibrated and not calibrated with satellite wind data) 2. use Storm Surge Model initial conditions determined from altimeter TWLE data. The experience gained working with scatterometer and Numerical Weather Prediction (NWP) winds in the Adriatic Sea tells us that the bias NWP-Scatt wind is negative and spatially and temporally not uniform. In particular, a well established point is that the bias is higher close to coasts then offshore. Therefore, NWP wind speed calibration will be carried out on each single grid point in the Adriatic Sea domain over the period of a Storm Surge Event, taking into account of existing published methods. Point #2 considers two different methodologies to be used in re-analysis tests. One is based on the use of the TWLE values from altimeter data in the Storm Surge Model (SSM), applying data assimilation methodologies and trying to optimize the initial conditions of the

  3. Blockade of LH release and ovulation in the rabbit with inhibitory analogues of luteinizing hormone releasing hormone.

    Science.gov (United States)

    Phelps, C P; Coy, D H; Schally, A V; Sawyer, C H

    1977-06-01

    Plasma LH levels and ovulation were studied in female rabbits following administration of several inhibitory analogues of luteinizing hormone-releasing hormone (LHRH) before and after mating with experienced males. Administration of (D-Phe2, D-Leu6)-LHRH (1.5 mg/kg sc) to does 30 min before mating did not prevent either LH release or ovulation. However, a single sc injection of (D-Phe2, L-Phe3, D-Phe6y-LHRH (6 mg/kg) given 30 min before mating in 4 rabbits resulted in a 30-60 min delay in the coitus-induced release of LH when compared with post-coital changes in the same animals injected with vehicle; however, all of the does ovulated. When multiple dosages of 4 mg/kg (D-Phe2, L-Phe3, D-Phe6)-LHRH were administered 3-5 times at half-hourly intervals beginning 30 min prior to mating there was a considerable reduction in plasma LH elevations at 0.5, 1.0, 2.0 and 4.0 h after mating and 3/5 treated rabbits showed partial or complete blockade of ovulation. Quite similar results were obtained with the same dosage of (D-Phe2, D-Trp3, D-Phe6)-LHRH. An early sharp peak in LH release and full ovulation were stimulated in 6 out of 6 does by a single iv injection of synthetic LHRH (500 ng/kg). However, in another experiment, three half-hourly sc injections (4 mg/kg) of (D-Phe2, L-Phe3, D-Phe6)-LHRH beginning 30 min before administering LHRH markedly reduced the rise in plasma LH (P less than 0.01) and completely blocked ovulation in all of the same 6 animals. An unsuccessful attempt was made to provide a test animal for LHRH analogue investigations by implanting 4 cm of silastic tubing filled with crystalline estradiol (E2) sc in ovariectomized (OVX) AND INTACT DOES. In OVX does the silastic E2 implants resulted in a progressive decline in the ability to release LH in response to mating at 6 and at 20 days after implantation. With ovaries present, the E2 implant permitted post-coital LH release and ovulation at 4 d but not at 30 d post-implantation. At 30 d after removal of

  4. Diagnostic Value of LH/FSH Ratio on Polycystic Ovary Syndrome%LH/FSH比值对多囊卵巢综合征的诊断价值分析

    Institute of Scientific and Technical Information of China (English)

    刘红霞

    2016-01-01

    目的:探讨LH/FSH比值对多囊卵巢综合征的临床诊断意义.方法:选择2013年11月-2015年11月期间本院收治的90例多囊卵巢综合征患者作为观察组,再选择同期体检的60例健康女性为对照组,基于2组LH及FSH常规临检结果分析两组LH/FSH比值的差异.结果:对照组相比,观察组患者LH/FSH比值显著增高,组间比较,差异具有统计学意义(P<0.05).结论:LH/FSH比值升高为多囊卵巢综合征患者重要生殖内分泌改变特征,对多囊卵巢综合征诊断具有较大临床价值.

  5. 基于LH-M10实验箱的模拟智能家居控制系统%Simulate Control System of Smart Home Based on LH-M10 Experiment Box

    Institute of Scientific and Technical Information of China (English)

    舒展

    2016-01-01

    智能家居是家庭自动化的高级阶段,是科技发展的必然结果。基于LH-M10实验箱的模拟智能家居控制系统的设计与开发,设计利用LH-M10实验箱的硬件设备,涵盖了信息数据采集、信息数据处理和信息数据反馈等多个方面,从原理层面实现了智能家居系统中具有代表性的模块展示,并结合智能家居的发展趋势,对此系统后续的研发拓展进行了展望。%Smart homewhich is the advanced stage of Home Automation, is the inevitable result of the development of science and technology. The design and development of this system which named simulate control system of smart home based on LH-M10 experiment box, is using LH-M10 experiment box hardware, and is the demo implement of the typical modules in smart home system. Also this system coversinformation data collection, procession, and feedback. After considering the trend of smart home, the further researching plan has been prospected.

  6. Mapping Risks Due To Storm Surges Within The Coastal Zone

    Science.gov (United States)

    Mai, S.; Zimmermann, C.

    The coast protection at the Wadden Sea coastline of Lower Saxony, Germany, is mainly guaranteed by sea dikes. In case of a failure of these dikes a total area of approx. 7.130 km2 is endangered from inundation. Besides that approx. 1.3 million people and economic values of 150 billion Euro are at risk. The consequences of dike failure show a large spatial variability. However today's design of sea dikes does not take into account the spatial variability, i.e. coastal areas with high losses in case of dike failure are not protected better than those with low. In order to improve this sit- uation a scheme for risk analysis was developed and applied at the estuaries Jade and Weser including the cities Wilhelmshaven, Bremerhaven, Bremen and Cuxhaven. The scheme of risk analysis comprises on the one hand a calculation of the probability of dike failure and a determination of the area flooded in case of dike breaching and on the other hand a register of all values, i.e. houses, industrial estates and infrastructure, within the hinterland. The different steps are integrated and linked to a Geographical Information System GIS using ARCVIEW. Within the developed design scheme failure of sea dikes is related to wave overtop- ping. Therefore the probability of failure is determined from the joined probability of tidal high water-levels and waves. The statistics of latter are calculated from the wind statistics using the numerical wave model SWAN. The time dependent flooding process after dike breaches is calculated with the numer- ical model MIKE 21 HD providing information on the depth, velocity and duration of the inundation. The sensitivity of the calculations of the inundation characteristics with respect to the width of the dike breach, the surface roughness and the character- istics of the storm surge is evaluated. The inundation depth and speed is used to estimate the damage factor, i.e. the ratio of the expected loss after inundation and the maximum possible loss. The

  7. Morning blood pressure surge: the reliability of different definitions.

    Science.gov (United States)

    Stergiou, George S; Mastorantonakis, Stylianos E; Roussias, Leonidas G

    2008-08-01

    Preliminary evidence suggests that the morning surge (MS) in blood pressure (BP) is an independent predictor of cerebrovascular disease. However, the optimal definition of MS is uncertain. To compare the reproducibility of several MS definitions used in the literature, 132 untreated hypertensives were assessed with ambulatory BP monitoring twice, 2 weeks apart. Five MS definitions were compared. MS-1: the average BP of the first hour after rising minus the average BP of the first hour before rising; MS-2: BP 2 h after rising minus that of 2 h before rising; MS-3: BP 3 h after rising minus that of 3 h before rising; MS-4: BP 2 h after rising minus the average BP during sleep; MS-5: BP 2 h after rising minus the average BP of 3 consecutive readings, centered on the lowest reading during sleep. The reproducibility of each MS definition was assessed using the concordance correlation coefficient (CCC), the standard deviation of differences (SDD) and the coefficient of variation (CV) between repeated MS assessments, and the agreement in detecting "surgers," defined as subjects at the top quartile (Q4) of the MS distribution. CCCs were 0.20/0.30, 0.43/0.45, 0.53/0.51, 0.51/0.47, and 0.46/0.48 (systolic/diastolic) for MS-1 to MS-5 respectively; SDDs were 14.3/11.4, 12.1/9.9, 11.2/9.5, 10.3/8.2, and 11.9/9.8, respectively; CVs were 0.49/0.57, 0.44/0.39, 0.37/0.35, 0.36/0.31, and 0.27/0.24, respectively; and the agreement in detecting "surgers" was 69%/70%, 71%/76%, 75%/75%, 81%/83%, and 74%/75%, with kappa of 0.18/0.20, 0.23/0.36, 0.33/0.33, 0.49/0.53 and 0.29/0.31, respectively. There are important differences in the reproducibility of MS calculated by different methods. MS4 appears to provide the most reproducible definition of MS.

  8. Selection of gonadotrophin surge attenuating factor phage antibodies by bioassay

    Directory of Open Access Journals (Sweden)

    Mason Helen D

    2005-09-01

    Full Text Available Abstract Background 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. Methods 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. Results 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. Conclusion This study demonstrates that the combination of

  9. Alterations in bone morphogenetic protein 15, growth differentiation factor 9, and gene expression in granulosa cells in preovulatory follicles of dairy cows given porcine LH.

    Science.gov (United States)

    Behrouzi, Amir; Colazo, Marcos Germán; Ambrose, Divakar Justus

    2016-04-15

    In a previous work, using porcine LH (pLH) in lieu of GnRH for synchronizing ovulation in dairy cows improved pregnancy rates without increasing plasma progesterone concentrations after ovulation. The LH profile is known to remain elevated above basal concentrations (≥1 ng/mL) for up to 20 hours in pLH-treated cows compared to less than 6 hours in GnRH-treated cows. Because LH triggers a cascade of signaling networks in the preovulatory follicle to promote final maturation and support oocyte competence, we hypothesized that dissimilar LH profiles will differentially regulate the intrafollicular factors and expression of downstream genes associated with improved oocyte competence. Specific objectives were to determine differences in the abundance of oocyte-secreted factors in the preovulatory follicular fluid and target genes in granulosa cells associated with oocyte competence, in response to exogenous porcine LH or GnRH-induced endogenous bovine LH exposure, in dairy cows. Follicular contents were aspirated by a transvaginal ultrasound-guided procedure from the preovulatory follicle of cyclic, nonlactating Holstein cows 21 ± 1 hour after administration of either pLH (25-mg) or GnRH (100-μg). Mature forms of bone morphogenetic protein 15, growth differentiation factor 9, and transforming growth factorβ1 were approximately 2-fold more abundant in pLH-treated cows which were exposed to an extended, low LH profile, than in GnRH-treated cows that had a short, high LH profile. The relative abundance of messenger RNA for cyclooxygenase-2, LH receptor, and progesterone receptor in granulosa cells, was about two-, eight-, and two-fold higher, respectively, in cows subjected to pLH than GnRH treatment. We infer that the improved pregnancy rate after pLH-induced ovulation reported previously, occurred through greater activation of intrafollicular transforming growth factor-β1 superfamily members, as these proteins promote cumulus expansion and oocyte competence.

  10. Mitigation of hurricane storm surge impacts: Modeling scenarios over wide continental shelves

    Science.gov (United States)

    Lima Rego, Joao; Li, Chunyan

    2010-05-01

    The improvement of present understanding of surge dynamics over wide and shallow shelves is vital for the improvement of our ability to forecast storm surge impacts to coastal regions, particularly the low-lying land areas that are most vulnerable to hurricane flooding (e.g. the Northern Gulf of Mexico, coastal Bangladesh, the Southeast China sea). Given the increase of global sea-surface temperature, both the total number and proportion of intense tropical cyclones have increased notably since 1970 (Emanuel, 2005; Nature). Therefore, more intense hurricanes may hit densely populated coastal regions, and this problem may be aggravated by the prospect of accelerated sea-level rise in the 21st century. This presentation offers a review of recent work on hurricane-induced storm surge. The finite-volume coastal ocean model ("FVCOM", by Chen et al., 2003; J. Atmos. Ocean Tech.) was applied to the storm surge induced by Hurricanes Rita and Ike along the coasts of Louisiana and Texas in 2005 and 2008, respectively, to study coastal storm surge dynamics. The sensitivity analysis of Rego and Li (2009; Geophys. Res. Lett.) demonstrated how stronger, wider or faster tropical cyclones would affect coastal flooding. Li, Weeks and Rego (2009; Geophys. Res. Lett) looked into how hurricane flooding and receding dynamics differ, concluding that the overland flow in the latter stage is of considerable importance. Rego and Li (2010; J. Geophys. Res.) showed how extreme events may result of a combination of non-extreme factors, by studying the nonlinear interaction of tide and hurricane surge. The ability of models to reproduce these extreme events and to proactive plan for damage reduction is covered in Rego and Li's (2010; J. Marine Syst.) study of how barrier island systems protect coastal bays from offshore surge propagation. Here we combine these results for a wider perspective on how hurricane flooding could be mitigated under changing conditions.

  11. Studies on scaled models for gas entrainment in the surge tank of LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Ramdasu, D.; Shivakumar, N.S.; Padmakumar, G.; Anand Babu, C.; Vaidyanathan, G. [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Rammohan, S.; Sreekala, S.K.; Manikandan, S.; Saseendran, S. [Fluid Control Research Institute, Palghat (India)

    2007-07-01

    This paper presents the studies carried out in the different scale models of Surge tank used in the secondary circuit of Liquid metal fast breeder reactor (LMFBR). Surge tank acquires importance because of its ability to take care of pressure surges in case of a sodium water reaction in Steam Generators (SG). The blanket of argon cover gas above the sodium free surface in the surge tank acts as a cushion for the surges. At the same time, argon gas is a source of entrainment into the sodium which is undesirable from the consideration of effective heat transfer in Inter mediate Heat Exchanger and SG, cavitation in pumps and operational problems of continuous feed and bleed of cover gas, thus leading to unfavourable reactor operating conditions. To investigate the phenomenon of gas entrainment in surge tank, hydraulic experiments were conducted in water using 1/38, 1/32, 1/22 and 1/12 scale models with Froude similarity. The minimum height of liquid column required to avoid gas entrainment was determined using different types of internal devices. Experiments were carried out in the 5/8 scale model to confirm the results of the smaller scale models. It was found that free surface height to avoid gas entrainment varies for different scale models. The combination of Pepper pot with ring plate was found to be the most effective in avoiding gas entrainment at H/D equals 1.28 where H is the height of liquid column in the tank from tank bottom and D is the inner diameter of surge tank.

  12. 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.

  13. Investigating changes in basal conditions of Variegated Glacier prior and during its 1982–1983 surge

    Directory of Open Access Journals (Sweden)

    O. Gagliardini

    2011-05-01

    Full Text Available The Variegated Glacier (Alaska is known to surge periodically after a sufficient amount of cumulative mass balance is reached, but this observation is difficult to link with changes in the basal conditions. Here, using a 10-year dataset, consisting in surface topography and surface velocity observations along a flow line for 25 dates, we have reconstructed the evolution of the basal conditions prior and during the 1982–1983 surge. The model solves the full-Stokes problem along the central flow line using the finite element method. For the 25 dates of the dataset, the basal friction parameter distribution is inferred using the inverse method proposed by Arthern and Gudmundson (2010. This method is here slightly modified by incorporating a regularisation term in the cost function to avoid short wave length changes in the friction parameter. Our results indicate that dramatic changes in the basal conditions occurred between 1973 to 1983. Prior to the surge, periodical changes can be observed between winter and summer, with a regular increase of the sliding from 1973 to 1982. During the surge, the basal friction decreased dramatically and an area of very low friction moved from the upper part of the glacier to its terminus. Using a more complex friction law, these changes in basal sliding are then interpreted in terms of basal water pressure. It confirms that dramatic changes took place in the subglacial drainage system of Variegated Glacier, moving from a relatively efficient drainage system prior to the surge to an inefficient one during the surge. By reconstructing the water pressure evolution at the base of the glacier it is possible to infer realistic scenarios for the hydrological history leading to the occurrence of a surge.

  14. Tsivat Basin conduit system persists through two surges, Bering Piedmont Glacier, Alaska

    Science.gov (United States)

    Fleisher, P.J.; Cadwell, D.H.; Muller, E.H.

    1998-01-01

    The 1993-1995 surge of Bering Glacier, Alaska, occurred in two distinct phases. Phase 1 of the surge began on the eastern sector in July, 1993 and ended in July, 1994 after a powerful outburst of subglacial meltwater into Tsivat Lake basin on the north side of Weeping Peat Island. Within days, jokulhlaup discharge built a 1.5 km2 delta of ice blocks (25-30 m) buried in outwash. By late October 1994, discharge temporarily shifted to a vent on Weeping Peat Island, where a second smaller outburst dissected the island and built two new sandar. During phase 2, which began in spring 1995 and ended within five months, continuous discharge issued from several vents along the ice front on Weeping Peat Island before returining to the Tsivat Basin. Surge related changes include a five- to six-fold increase in meltwater turbidity; the redirection of supercooled water in two ice-contact lakes; and an increase in the rate of glaciolacustrine sedimentation. US Geological Survey aerial photos by Austin Post show large ice blocks in braided channels indicating excessive subglacial discharge in a similar position adjacent to Weeping Peat Island during the 1966-1967 surge. During the subsequent three decades of retreat, the location of ice-marginal, subglacial discharge vents remained aligned on a linear trend that describes the position of a persistent subglacial conduit system. The presence of a major conduit system, possibly stabilized by subglacial bedrock topography, is suggested by: 1) high-level subglacial meltwater venting along the northern side of Weeping Peat Island during the 1966-1967 surge, 2) persistent low-level discharge between surges, and 3) the recurrence of localizing meltwater outbursts associated with both phases of the 1993-1005 surge.

  15. Chicken granulosa cells show differential expression of epidermal growth factor (EGF) and luteinizing hormone (LH) receptor messenger RNA and differential responsiveness to EGF and LH dependent upon location of granulosa cells to the germinal disc.

    Science.gov (United States)

    Yao, H H; Bahr, J M

    2001-06-01

    Granulosa cells in the chicken follicle exhibit different phenotypes according to their location relative to the germinal disc (GD). Granulosa cells proximal to the GD (referred to as proximal granulosa cells) are more proliferative, whereas granulosa cells distal to the GD (referred to as distal granulosa cells) are more differentiated. We have shown that epidermal growth factor (EGF) derived from the GD stimulated proliferation of granulosa cells proximal to the GD, whereas extraovarian LH promoted differentiation. We tested the hypothesis that phenotypic differences of granulosa cells are the result of differential responsiveness of granulosa cells to EGF and LH. We found that both granulosa and theca layers of chicken preovulatory follicles expressed mRNA for EGF receptor (EGFr) by polymerase chain reaction (PCR) analysis. However, only the granulosa layer showed differential expression of EGFr and LH receptor (LHr) mRNA. Competitive reverse transcription-PCR revealed that proximal granulosa cells expressed more EGFr mRNA but less LHr mRNA than distal granulosa cells. In addition, proximal granulosa cells proliferated more in response to EGF than their distal counterparts. We further demonstrated that EGF decreased LHr mRNA expression by granulosa cells in a dose-dependent manner, whereas EGF and LH had no effect on EGFr mRNA expression except at one dose of LH (15 ng/ml) that stimulated EGFr mRNA expression. Our findings suggest that EGF derived from the GD influences the phenotypes of granulosa cells. Granulosa cells proximal to the GD exhibit a proliferative phenotype possibly because they are exposed to and are more responsive to GD-derived EGF. Furthermore, GD-derived EGF decreases LHr mRNA expression by proximal granulosa cells and therefore results in less differentiated granulosa cell phenotype. In contrast, granulosa cells distal to the GD are not under the influence of EGF and exhibit a more differentiated phenotype.

  16. A mathematical model for LH release in response to continuous and pulsatile exposure of gonadotrophs to GnRH

    Directory of Open Access Journals (Sweden)

    Reed Michael C

    2004-09-01

    Full Text Available Abstract In a previous study, a model was developed to investigate the release of luteinizing hormone (LH from pituitary cells in response to a short pulse of gonadotropin-releasing hormone (GnRH. The model included: binding of GnRH to its receptor (R, dimerization and internalization of the hormone receptor complex, interaction with a G protein, production of inositol 1,4,5-trisphosphate (IP3, release of calcium from the endoplasmic reticulum (ER, entrance of calcium into the cytosol via voltage gated membrane channels, pumping of calcium out of the cytosol via membrane and ER pumps, and release of LH. The extended model, presented in this paper, also includes the following physiologically important phenomena: desensitization of calcium channels; internalization of the dimerized receptors and recycling of some of the internalized receptors; an increase in Gq concentration near the plasma membrane in response to receptor dimerization; and basal rates of synthesis and degradation of the receptors. With suitable choices of the parameters, good agreement with a variety of experimental data of the LH release pattern in response to pulses of various durations, repetition rates, and concentrations of GnRH were obtained. The mathematical model allows us to assess the effects of internalization and desensitization on the shapes and time courses of LH response curves.

  17. Variation in LH pulsatility during 24 h after a postweaning altrenogest treatment in relation to follicle development in primiparous sows

    NARCIS (Netherlands)

    Leeuwen, van J.J.J.; Martens, M.R.T.M.; Jourquin, J.; Draincourt, M.A.; Kemp, B.; Soede, N.M.

    2011-01-01

    This study assessed pulsatile release of LH during altrenogest treatment after weaning in primiparous sows and related this to follicle development, estrus and ovulation rate. Weaned sows (n = 10) received altrenogest 20 mg/day from D-1 to D13 (weaning = D0) at 0800 h. On D13, blood samples were col

  18. Electrochemical stimulation of plasma LH and hypothalamic norepinephrine concentrations at short- and long-term intervals after hypothalamic knife cuts.

    Science.gov (United States)

    Phelps, C P; Saporta, S

    1985-11-18

    Norepinephrine (NE) concentrations in several diencephalic locations were studied in female rats in conjunction with luteinizing hormone (LH) release after medial preoptic area (MPOA) stimulation at short (7 days) and longer time intervals after surgical interruption of anterior or anterolateral neural connections of mediobasal hypothalamus (MBH). Concentrations of diencephalic NE were altered in two general ways after brain surgery: (1) transient early postoperative increases in some regions which appeared unrelated to the type of surgery performed; and (2) other specific decreases in NE concentration which were related to the types of surgery performed and whether a particular ascending noradrenergic pathway was interrupted. At 180 days after surgery, these two types of change in NE concentrations were no longer present. Maximum increases in plasma LH concentrations observed after electrochemical stimulation of the MPOA at either 7 or 180 days after MBH deafferentation also varied according to: (1) the postoperative interval studied; and (2) the location of pathway interruption. Interruption of anterior MBH pathways showed only a transient (7 day interval) reduction in LH release after MPOA stimulation, whereas when both lateral and anterior pathways were severed, there was a more nearly permanent (180 day interval) disruption of LH release after stimulation. The results of these studies support the contention that anterolateral MBH neural connections may constitute a dynamic neural substrate contributing to a gradual improvement in neuroendocrine function observed after early surgical disconnections.

  19. Fluorescence polarization measures energy funneling in single light-harvesting antennas--LH2 vs conjugated polymers.

    Science.gov (United States)

    Camacho, Rafael; Tubasum, Sumera; Southall, June; Cogdell, Richard J; Sforazzini, Giuseppe; Anderson, Harry L; Pullerits, Tõnu; Scheblykin, Ivan G

    2015-10-19

    Numerous approaches have been proposed to mimic natural photosynthesis using artificial antenna systems, such as conjugated polymers (CPs), dendrimers, and J-aggregates. As a result, there is a need to characterize and compare the excitation energy transfer (EET) properties of various natural and artificial antennas. Here we experimentally show that EET in single antennas can be characterized by 2D polarization imaging using the single funnel approximation. This methodology addresses the ability of an individual antenna to transfer its absorbed energy towards a single pool of emissive states, using a single parameter called energy funneling efficiency (ε). We studied individual peripheral antennas of purple bacteria (LH2) and single CP chains of 20 nm length. As expected from a perfect antenna, LH2s showed funneling efficiencies close to unity. In contrast, CPs showed lower average funneling efficiencies, greatly varying from molecule to molecule. Cyclodextrin insulation of the conjugated backbone improves EET, increasing the fraction of CPs possessing ε = 1. Comparison between LH2s and CPs shows the importance of the protection systems and the protein scaffold of LH2, which keep the chromophores in functional form and at such geometrical arrangement that ensures excellent EET.

  20. Fluorescence polarization measures energy funneling in single light-harvesting antennas—LH2 vs conjugated polymers

    Science.gov (United States)

    Camacho, Rafael; Tubasum, Sumera; Southall, June; Cogdell, Richard J.; Sforazzini, Giuseppe; Anderson, Harry L.; Pullerits, Tõnu; Scheblykin, Ivan G.

    2015-01-01

    Numerous approaches have been proposed to mimic natural photosynthesis using artificial antenna systems, such as conjugated polymers (CPs), dendrimers, and J-aggregates. As a result, there is a need to characterize and compare the excitation energy transfer (EET) properties of various natural and artificial antennas. Here we experimentally show that EET in single antennas can be characterized by 2D polarization imaging using the single funnel approximation. This methodology addresses the ability of an individual antenna to transfer its absorbed energy towards a single pool of emissive states, using a single parameter called energy funneling efficiency (ε). We studied individual peripheral antennas of purple bacteria (LH2) and single CP chains of 20 nm length. As expected from a perfect antenna, LH2s showed funneling efficiencies close to unity. In contrast, CPs showed lower average funneling efficiencies, greatly varying from molecule to molecule. Cyclodextrin insulation of the conjugated backbone improves EET, increasing the fraction of CPs possessing ε = 1. Comparison between LH2s and CPs shows the importance of the protection systems and the protein scaffold of LH2, which keep the chromophores in functional form and at such geometrical arrangement that ensures excellent EET. PMID:26478272

  1. 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.

  2. A probabilistic storm surge risk model for the German North Sea and Baltic Sea coast

    Science.gov (United States)

    Grabbert, Jan-Henrik; Reiner, Andreas; Deepen, Jan; Rodda, Harvey; Mai, Stephan; Pfeifer, Dietmar

    2010-05-01

    The German North Sea coast is highly exposed to storm surges. Due to its concave bay-like shape mainly orientated to the North-West, cyclones from Western, North-Western and Northern directions together with astronomical tide cause storm surges accumulating the water in the German bight. Due to the existence of widespread low-lying areas (below 5m above mean sea level) behind the defenses, large areas including large economic values are exposed to coastal flooding including cities like Hamburg or Bremen. The occurrence of extreme storm surges in the past like e.g. in 1962 taking about 300 lives and causing widespread flooding and 1976 raised the awareness and led to a redesign of the coastal defenses which provide a good level of protection for today's conditions. Never the less the risk of flooding exists. Moreover an amplification of storm surge risk can be expected under the influence of climate change. The Baltic Sea coast is also exposed to storm surges, which are caused by other meteorological patterns. The influence of the astronomical tide is quite low instead high water levels are induced by strong winds only. Since the exceptional extreme event in 1872 storm surge hazard has been more or less forgotten. Although such an event is very unlikely to happen, it is not impossible. Storm surge risk is currently (almost) non-insurable in Germany. The potential risk is difficult to quantify as there are almost no historical losses available. Also premiums are difficult to assess. Therefore a new storm surge risk model is being developed to provide a basis for a probabilistic quantification of potential losses from coastal inundation. The model is funded by the GDV (German Insurance Association) and is planned to be used within the German insurance sector. Results might be used for a discussion of insurance cover for storm surge. The model consists of a probabilistic event driven hazard and a vulnerability module, furthermore an exposure interface and a financial

  3. Impacts of land cover changes on hurricane storm surge in the lower Chesapeake Bay

    Science.gov (United States)

    Denton, M.; Lawler, S.; Ferreira, C.

    2013-12-01

    The Chesapeake Bay is the largest estuary in the United States with more than 150 rivers draining into the bay's tidal wetlands. Coastal wetlands and vegetation play an important role in shaping the hydrodynamics of storm surge events by retaining water and slowing the propagation of storm surge. In this way coastal wetlands act as a natural barrier to inland flooding, particularly against less intense storms. Threats to wetlands come from both land development (residential or commercial/industrial) and sea level rise. The lower region of the Chesapeake Bay near its outlet is especially vulnerable to flooding from Atlantic storm surge brought in by hurricanes, tropical storms and nor'easters (e.g., hurricanes Isabel [2003] and Sandy [2012]). This region is also intensely developed with nearly 1.7 million residents within the greater Hampton Roads metropolitan area. Anthropogenic changes to land cover in the lower bay can directly impact basin drainage and storm surge propagation with impacts reaching beyond the immediate coastal zone to affect flooding in inland areas. While construction of seawall barriers around population centers may provide storm surge protection to a specifically defined area, these barriers deflect storm surge rather than attenuate it, underscoring the importance of wetlands. To analyze these impacts a framework was developed combining numerical simulations with a detailed hydrodynamic characterization of flow through coastal wetland areas. Storm surges were calculated using a hydrodynamic model (ADCIRC) coupled to a wave model (SWAN) forced by an asymmetric hurricane vortex model using the FEMA region 3 unstructured mesh (2.3 million nodes) under a High Performance Computing (HPC) environment. Multiple model simulations were performed using historical hurricanes data and hypothetical storms to compare the predicted storm surge inundation with various levels of wetland reduction and/or beach hardening. These data were combined and overlaid

  4. EFFECT OF INVIVO PRETREATMENT WITH ESTRADIOL AND EITHER GNRH, GNRH AGONISTIC ANALOG OR GNRH ANTAGONISTIC ANALOG ON GNRH-STIMULATED SECRETION OF LH INVITRO

    NARCIS (Netherlands)

    SCHUILING, GA; KOITER, TR; MOES, H

    1991-01-01

    In vivo treatment with GnRH or with GnRH agonistic analog (AG), but not with GnRH antagonistic analog (ANT), depleted the LH stores of the rat pituitary gland. This depletion was potentiated by oestradiol. Oestradiol augmented the in vitro LH response of the pituitary gland to GnRH. This augmenting

  5. A common polymorphic allele of the LH beta-subunit gene is associated with higher exogenous FSH consumption during controlled ovarian stimulation for assisted reproductive technology

    DEFF Research Database (Denmark)

    Alviggi, Carlo; Pettersson, Kim; Longobardi, Salvatore

    2013-01-01

    a long GnRH-agonist down-regulation protocol received an individualized dose of r-hFSH (100 IU and 375 IU s.c. daily) according to antral follicle count, baseline FSH, body mass index and age. The LH genotype was assessed in all patients by immunofluorometric assay. RESULTS: V-betaLH was present in 11...

  6. Ghrelin suppresses nocturnal secretion of luteinizing hormone (LH) and thyroid stimulating hormone (TSH) in patients with major depression.

    Science.gov (United States)

    Kluge, Michael; Schmidt, Doreen; Uhr, Manfred; Steiger, Axel

    2013-09-01

    Major depression is associated with various endocrine disturbances. Apart from the well-known hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, also the function of the hypothalamic-pituitary-gonadal (HPG) axis and of the hypothalamic-pituitary-thyroid (HPT) axis may be altered compared to healthy subjects. The orexigenic hormone ghrelin is involved in mood regulation and may have antidepressant effects. In addition, it has been shown to suppress secretion of luteinizing hormone (LH) and thyroid stimulating hormone (TSH) in healthy subjects. Aim of this study was therefore to test the effect of ghrelin on the activity of the HPG and HPT axis in patients with major depression. Therefore, secretion profiles of LH and TSH were determined in 14 unmedicated patients with major depression (7 women) twice, receiving 50 μg ghrelin or placebo at 2200, 2300, 0000, and 0100 h. LH secretion after ghrelin injection as assessed by the AUC (4.05 ± 1.18 mlIU min/ml) was significantly (P = 0.049) lower than after placebo injection (4.75 ± 1.33 mlIU min/ml) during the predefined intervention period (2220-0200 h). In addition, LH pulses occurred significantly (P = 0.045) less frequently after ghrelin injection (3.2 ± 1.4) than after placebo injection (3.9 ± 1.7). Mean TSH plasma levels were significantly lower at 0240 h and from 0320 until 0420 h after ghrelin injection than after placebo injection. In conclusion, ghrelin suppressed nocturnal secretion of LH and TSH in patients with major depression. However, these effects were weaker than previously shown in healthy subjects.

  7. The origin of the split B800 absorption peak in the LH2 complexes from Allochromatium vinosum.

    Science.gov (United States)

    Löhner, Alexander; Carey, Anne-Marie; Hacking, Kirsty; Picken, Nichola; Kelly, Sharon; Cogdell, Richard; Köhler, Jürgen

    2015-01-01

    The absorption spectrum of the high-light peripheral light-harvesting (LH) complex from the photosynthetic purple bacterium Allochromatium vinosum features two strong absorptions around 800 and 850 nm. For the LH2 complexes from the species Rhodopseudomonas acidophila and Rhodospirillum molischianum, where high-resolution X-ray structures are available, similar bands have been observed and were assigned to two pigment pools of BChl a molecules that are arranged in two concentric rings (B800 and B850) with nine (acidophila) or eight (molischianum) repeat units, respectively. However, for the high-light peripheral LH complex from Alc. vinosum, the intruiging feature is that the B800 band is split into two components. We have studied this pigment-protein complex by ensemble CD spectroscopy and polarisation-resolved single-molecule spectroscopy. Assuming that the high-light peripheral LH complex in Alc. vinosum is constructed on the same modular principle as described for LH2 from Rps. acidophila and Rsp. molischianum, we used those repeat units as a starting point for simulating the spectra. We find the best agreement between simulation and experiment for a ring-like oligomer of 12 repeat units, where the mutual arrangement of the B800 and B850 rings resembles those from Rsp. molischianum. The splitting of the B800 band can be reproduced if both an excitonic coupling between dimers of B800 molecules and their interaction with the B850 manifold are taken into account. Such dimers predict an interesting apoprotein organisation as discussed below.

  8. Comparison of platelet counts by sysmex XE 2100 and LH-750 with the international flow reference method in thrombocytopenic patients

    Directory of Open Access Journals (Sweden)

    Tina Dadu

    2013-01-01

    Full Text Available Background: There are several methods for counting platelets, of which the international flow reference method (IRM is considered to be the gold standard. We compared the platelet count given by this method to the count given by automated analyzers using other methods, such as optical fluorescence and impedance. Aims: The aim of this study is to compare the platelet counts obtained by Sysmex XE 2100 by Impedance (Sysmex-I, optical florescence (Sysmex-O and reported (Sysmex-R based on the switching algorithm and LH-750 by Impedance (LH-750 with the IRM in thrombocytopenic blood samples. To calculate the sensitivity, specificity, positive predictive value (PPV and negative predictive value (NPV of various technologies at the clinically relevant transfusion thresholds of 10 × 10 9 /l and 20 × 10 9 /l. Materials and Methods: A total of 118 blood samples with platelet count of <50 × 10 9 /l were selected for the study. Platelet counts of all samples were analyzed by all methods using the Sysmex analyzer, LH-750 and IRM in parallel within 6 h of collection. Statistical Analysis Used: Pearson correlation, bland Altman analysis, sensitivity and specificity, PPV and NPV. Results and Conclusions: Sysmex-R had the least Bias and 95% limits of agreement (95%LA range and thus correlated best with IRM values. LH-750 had a higher Bias compared to Sysmex-O and Sysmex-R, but a strikingly similar 95% LA ensures similar results in all three methods. In fact, in the oncology subset, it had the narrowest 95% LA, which made it the best performer in this subgroup. Of the three Sysmex results, Sysmex-I had the highest bias, widest 95% LA and highest potential risk of over transfusion. Hence, Sysmex-R and LH-750 were found to be reliable tools for estimation of platelet count in thrombocytopenic patients.

  9. Breast Cancer and Estrogen Biosynthesis in Adipose Tissue

    Science.gov (United States)

    1998-10-01

    displaced inconspicuous nuclei (Fig. 1). Fibroblasts, on the other hand, are spindly cells with eosinophilic cytoplasms and dark and elongated nuclei...pre-ovulatory stage. During this stage, increasing stimulation of cAMP by FSH elevates expression of CYP19, CYP11A (P450scc) and LH receptor in granu ...aromatase expression occurs in a number of human tissues and cell types, including the syncytiotrophoblast of the placenta (13), ovarian granu - losa

  10. Swift snowmelt and floods (lahars) caused by great pyroclastic surge at Mount St Helens volcano, Washington, 18 May 1980

    Science.gov (United States)

    Waitt, R.B.

    1989-01-01

    The initial explosions at Mount St. Helens, Washington, on the moring of 18 May 1980 developed into a huge pyroclastic surge that generated catastrophic floods off the east and west flanks of the volcano. Near-source surge deposits on the east and west were lithic, sorted, lacking in accretionary lapilli and vesiculated ash, not plastered against upright obstacles, and hot enough to char wood - all attributes of dry pyroclastic surge. Material deposited at the surge base on steep slopes near the volcano transformed into high-concentration lithic pyroclastic flows whose deposits contain charred wood and other features indicating that these flows were hot and dry. Stratigraphy shows that even the tail of the surge had passed the east and west volcano flanks before the geomorphically distinct floods (lahars) arrived. This field evidence undermines hypotheses that the turbulent surge was itself wet and that its heavy components segregated out to transform directly into lahars. Nor is there evidence that meters-thick snow-slab avalanches intimately mixed with the surge to form the floods. The floods must have instead originated by swift snowmelt at the base of a hot and relatively dry turbulent surge. Impacting hot pyroclasts probably transferred downslope momentum to the snow surface and churned snow grains into the surge base. Melting snow and accumulating hot surge debris may have moved initially as thousands of small thin slushflows. As these flows removed the surface snow and pyroclasts, newly uncovered snow was partly melted by the turbulent surge base; this and accumulating hot surge debris in turn began flowing, a self-sustaining process feeding the initial flows. The flows thus grew swiftly over tens of seconds and united downslope into great slushy ejecta-laden sheetfloods. Gravity accelerated the floods to more than 100 km/h as they swept down and off the volcano flanks while the snow component melted to form great debris-rich floods (lahars) channeled into

  11. Mass Balance Evolution of Black Rapids Glacier, Alaska, 1980–2100, and Its Implications for Surge Recurrence

    OpenAIRE

    Christian Kienholz; Regine Hock; Martin Truffer; Peter Bieniek; Richard Lader

    2017-01-01

    Surge-type Black Rapids Glacier, Alaska, has undergone strong retreat since it last surged in 1936–1937. To assess its evolution during the late Twentieth and Twenty-first centuries and determine potential implications for surge likelihood, we run a simplified glacier model over the periods 1980–2015 (hindcasting) and 2015–2100 (forecasting). The model is forced by daily temperature and precipitation fields, with downscaled reanalysis data used for the hindcasting. A constant climate scenario...

  12. A new on-line leakage current monitoring system of ZnO surge arresters

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bok-Hee [Research Center for Next-Generation High Voltage and Power Technology, Inha University, 253 Yonghyun-dong, Nam-ku, Incheon 402-751 (Korea, Republic of)]. E-mail: bhlee@inha.ac.kr; Kang, Sung-Man [Research Center for Next-Generation High Voltage and Power Technology, Inha University, 253 Yonghyun-dong, Nam-ku, Incheon 402-751 (Korea, Republic of)

    2005-05-15

    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. 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)

  14. Co-ordination of spark-gap protection with zinc-oxide surge arresters

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, A.; German, D.M.; Waters, R.T. [Cardiff Univ., School of Engineering, Cardiff (United Kingdom); Abdul-Malek, Z. [University of Technology (Malaysia)

    2001-01-01

    Zinc-oxide (ZnO) surge arresters are now well established as a very efficient and reliable form of overvoltage protection against both fast surges, such as those generated by lightning and gas-insulated switchgear, and high-energy surges generated by switching operations and temporary faults on the network. The addition of ZnO surge arresters to existing protection schemes reinforces the system's reliability and the security of supply. The protection characteristics of the parallel configuration formed by arresters and existing spark gaps at distribution voltages are studied. Tests on various spark-gap geometries, with and without surge arresters in parallel, have been carried out to determine breakdown characteristics, probability curves and voltage-time characteristics for different impulse shapes. It is found that the introduction of the arrester in the circuit modifies the prospective impulse which results in the shift of the breakdown characteristics towards higher voltages. A proposed circuit model, based on laboratory test data, is used to simulate such parallel configurations. Good agreement between test and simulated results is obtained. As a result of these tests, it is recommended that gap-sparkover characteristics based on short-tail (about 5{mu}s) impulses are used for insulation co-ordination. The role of parallel airgaps in preserving the arrester energy-rating limits is also discussed. (Author)

  15. Effective Installations Technique of Grounding Conductors for Metal Oxide Surge Arresters

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.H.; Kang, S.M. [Inha University, Inchon (Korea); Ryu, I.S. [Korea Electric Power Corporation, Seoul (Korea)

    2002-06-01

    This paper deals with the effects of grounding conductors for metal oxide surge arresters. When surge arresters are improperly installed, the results can cause costly damage of electrical equipments. In particular, the route of surge arrester connection is very important because bends and links of leads increase the impedances to lightning surges and tend to nullify the effectiveness of a grounding conductor. Therefore, there is a need to know how effe