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Sample records for nonhormonal estrus synchronization

  1. Influence of hormonal and nonhormonal estrus synchronization methods on follicular and oocyte quality in primiparous lactating does at early postpartum period.

    PubMed

    Arias-Alvarez, M; García-García, R M; Torres-Rovira, L; González-Bulnes, A; Rebollar, P G; Lorenzo, P L

    2010-01-01

    High-yield lactating does need effective estrus synchronization methods to improve their reproductive outcome by enhancing ovarian function. The aim of the current work was to analyze ovarian follicular and oocyte characteristics of hormonal and nonhormonal estrus synchronization regimes in primiparous lactating rabbit does (Oryctolagus cuniculus) in the early postpartum period (Day 11). Females were randomly treated with either (1) a hormonal standard treatment with 25 IU equine chorionic gonadotropin (eCG) 48h before artificial insemination (eCG group) or (2) an alternative nonhormonal treatment consisting of doe-litter separation 24h before artificial insemination (Bio group). No significant differences were found in serum estradiol and progesterone concentrations between experimental groups. During the histologic study, the Bio group presented a higher number of primordial (P<0.05) and primary follicles (P=0.07) compared with that of the eCG group, whereas secondary and antral follicular populations were similar. Rates of late atretic follicles assessed by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling technique were not different between treatments, but the eCG group showed a significantly higher number of mid-atretic follicles compared with that of the Bio group. Nuclear in vitro oocyte maturation (IVM), measured as metaphase II rate, and in vitro steroidogenic response of cumulus-oocyte complexes, measured by ELISA, did not show significant differences between treatments. However, confocal study showed that cytoplasmic maturation of oocytes, in terms of cortical granule migration rate, was significantly higher in the Bio group compared with that after the eCG treatment. In conclusion, transient doe-litter separation seems to improve ovarian response in terms of follicular health and oocyte competence compared with that after the eCG treatment. Therefore, a 24-h-long transient weaning could be an alternative nonhormonal method for

  2. Synchronization of estrus and fertility in zebu beef heifers treated with three estrus synchronization protocols.

    PubMed

    Corbet, N J; Miller, R G; Bindon, B M; Burrow, H M; D'Occhio, M J; Entwistle, K W; Fitzpatrick, L A; Wilkins, J F; Kinder, J E

    1999-02-01

    The effects on estrus and fertility of 3 estrus synchronization protocols were studied in Brahman beef heifers. In Treatment 1 (PGF protocol; n=234), heifers received 7.5 mg, i.m. prostianol on Day 0 and were inseminated after observed estrus until Day 5. Treatment 2 (10-d NOR protocol; n = 220) consisted of norgestomet (NOR; 3 mg, s.c. implant and 3 mg, i.m.) and estradiol valerate (5 mg, i.m.) treatment on Day -10, NOR implant removal and 400 IU, i.m. PMSG on Day 0, and AI after observed estrus through to Day 5. Treatment 3 (14-d NOR+PGF protocol; n = 168) constituted a NOR implant (3 mg, sc) on Day -14, NOR implant removal on Day 0, PGF on Day 16, and AI after observed estrus through to Day 21. All heifers were examined for return to estrus at the next cycle and inseminated after observed estrus. The heifers were then exposed to bulls for at least 21 d. During the period of estrus observation (5 d) after treatment, those heifers treated with the PGF protocol had a lower (P<0.01) rate of estrual response (58%) than heifers treated with the 10-d NOR (87%) or 14-d NOR+PGF (88%) protocol. Heifers treated with the 10-d NOR protocol displayed estrus earlier and had a closer synchrony of estrus than heifers treated with either the PGF or the 14-d NOR+PGF protocol. Heifers treated with the 14-d NOR+PGF protocol had higher (P<0.05) conception and calving rates (51 and 46%) to AI at the induced estrus than heifers treated with the PGF (45 and 27%) or the 10-d NOR (38 and 33%) protocol. Calving rate to 2 rounds of AI was greater (P<0.05) for heifers treated with the 14-d NOR-PGF (50%) protocol than heifers treated with the 10-d NOR (38%) but not the PGF (43%) protocol. Breeding season calving rates were similar among the 3 protocols. The results show that the 14-d NOR+PGF estrus synchronization protocol induced a high incidence of estrus with comparatively high fertility in Brahman heifers. PMID:10729049

  3. Estrus induction and synchronization in canids and felids.

    PubMed

    Kutzler, M A

    2007-08-01

    Indications for estrus induction in the dog and cat include potential missed breeding opportunities or conception failure, the treatment of primary or secondary anestrus, out-of-season breeding (feline) and synchronization of ovulation for embryo transfer programs. Reported methods for estrus induction in bitches and queens include the use of synthetic estrogens (diethylstilbesterol), dopamine agonists (bromocriptine and cabergoline), GnRH agonists (lutrelin, buserelin, fertirelin, deslorelin, and leuprolide), exogenous gonadotropins (LH, FSH, hCG, PMSG, and human menopausal gonadotropin) and opiate antagonists (naloxone). These methods vary widely in efficacy of inducing estrus as well as in the fertility of the induced estrus. The applicability of some of these methods for clinical practice is questionable. This review will summarize published reports on estrus induction in canids and felids, both wild and domestic, and provide an update on research using a long-acting injectable deslorelin preparation in bitches.

  4. Continuous presence of male on estrus onset, estrus duration, and ovulation in estrus-synchronized Boer goats.

    PubMed

    Romano, Juan E; Alkar, Abdalhamid; Fuentes-Hernández, Victor O; Amstalden, Marcel

    2016-04-15

    The objectives of the present study were to assess the effect of permanent contact of teasers without copulation on the interval from controlled internal drug release (CIDR) removal to estrus onset, estrus duration, ovulation time, number of ovulations, and interval from CIDR removal to ovulation time on estrus-synchronized Boer goats. During the fall season, a controlled randomized design experiment with two groups, control (CON; n = 18) and treatment (TRE; n = 18), was performed. The TRE group was maintained permanently in a pen with an aproned buck immediately after CIDR removal. The CON group was maintained in a different pen without permanent exposure to the male. All females were estrus synchronized with CIDR maintained in the vagina for 7 days and received 50 μg of GnRH im at device insertion and 5 mg of natural prostaglandin F-2α at device removal. Females were considered to be in estrus when they accepted mounting by the aproned bucks. Estrus was detected four times a day after CIDR removal (at 6 AM, 12 noon, 6 PM, and 12 midnight) using bucks with canvas apron as teasers. The ovulation time and number of ovulations were assessed by transrectal ultrasonography starting 24 hours after estrus onset and repeated every 6 hours until complete ovulation was detected. The estrus onset for the CON group was 44.0 ± 8.3 hours and for the TRE group, it was 37.0 ± 7.7 hours (P = 0.01). Estrus duration from the CON group was 43.7 ± 9.2 hours and for the TRE group, it was 38.3 ± 6.6 hours (P = 0.05). The first, last, and mean ovulation times for the CON group were 32.4 ± 5.3, 38.4 ± 3.4, and 35.4 ± 3.9 hours, and for the TRE group, the times were 31.8 ± 2.8, 36.7 ± 3.0, and 35.8 ± 3.6 hours, respectively (P = 0.85, P = 0.23, and P = 0.82, respectively). The number of ovulations for the CON and TRE groups was 2.6 ± 0.7 and 2.6 ± 0.6 ovulations, respectively (P = 0.96). The interval time for CIDR removal

  5. Evaluation of short estrus synchronization methods in dairy cows.

    PubMed

    Cirit, Umüt; Bacinoglu, Suleyman; Taş, Muzaffer; Demir, Kamber; Baş, Ahmet; Ak, Kemal; Ileri, Irfan Kamuran

    2008-12-01

    In the present study, two new short estrus synchronization methods have been developed for lactating dairy cows. The study was completed in three consecutive phases. In experiment (Exp) 1, 32 cows, that were not detected in estrus since calving between the 50th and 84th post-partum days, were treated with PGF2alpha (PGF, d-cloprostenol, 0.150 mg), estradiol propionate (EP, 2mg) and GnRH (lecirelina, 50 microg) at 24h intervals, respectively, and timed artificial insemination (TAI) was performed 48 h after PGF. Different from Exp 1, EP and GnRH were given at 48 and 60 h, respectively after PGF in Exp 2 (n=20), instead of 24 and 48 h. Ovulations were investigated by ultrasound for 7 days starting from the day of PGF treatment, and ovulation rates were compared with the ones obtained in Exp 1. In Exp 3, cows were given the same treatments as Exp 2, but treatments started at certain estrus stages. Cows detected in estrus and with a confirmed ovulation (n=27) after the second PGF given 11 days apart were assigned to three treatment groups. Treatment was initiated at Day 3 (group metestrus, n=9), Day 12 (group diestrus, n=9) and Day 18 (group proestrus, n=9) after ovulation. All cows included in Exp 3 were TAI between 16 and 20 h after GnRH treatment. In Exp 2 and 3, blood samples were obtained once every 2 days, starting from Day 0 to the 10th day after GnRH injection, and once every 4 days between the 10th and the 22nd days after GnRH to examine post-treatment luteal development. During the study, animals exhibiting natural estrus were inseminated and served as controls (n=85). The rate of estrus was found to be significantly higher in cows with an active corpus luteum (CL) at the start of Exp 1 (72.7% vs. 30.0%, P<0.05) and the pregnancy rate tended to be higher than cows without an active CL (40.9% vs. 10.0%, P=0.08). Compared to those in Exp 1, cows in Exp 2 had higher rates of synchronized ovulation (94.1% vs. 59.1%, P=0.013). In Exp 3, estrus (P<0.001) and

  6. Estrus synchronization affects WNT signaling in the porcine reproductive tract and embryos.

    PubMed

    Kiewisz, Jolanta; Kaczmarek, Monika M; Morawska, Ewa; Blitek, Agnieszka; Kapelanski, Wojciech; Ziecik, Adam J

    2011-12-01

    The purpose of the study was to investigate an effect of estrus synchronization with prostaglandin (PG) F(2α) and PMSG/hCG on WNT4, WNT5A, WNT7A, β-catenin (CTNNB1) and E-cadherin (CDH1) gene expression. The weight of the uterus, morphometrical parameters of the endometrium and the number of CL were recorded. The analysis of estradiol (E(2)), prostaglandin (PG) F(2α) and E(2) content in the uterine luminal flushings (ULFs) and progesterone (P(4)) level in the blood serum were conducted. RNA was isolated from endometrial, luteal and embryonic tissue of pregnant non-synchronized (Control; n = 15) and pregnant synchronized (PGF(2α)/PMSG/hCG; n = 15) pigs. Whereas there was no change in uterine weight, differences in height of endometrial surface and glandular epithelium were found. However, height of the endometrium, number of the glands and capillaries were unaffected. The total number of the CLs was higher (P < 0.05) in animals treated with PGF(2α)/PMSG/hCG. The amount of E(2) and P(4) was lower (P < 0.05, P < 0.001, respectively) in pregnant gilts administrated with PGF(2α)/PMSG/hCG. The concentration of PGF(2α) in ULFs was not affected by hormonal management, while PGE(2) was higher (P < 0.01) in hormonally in comparison to non-hormonally treated pigs. The content of WNT4 mRNA in conceptuses increased on particular Days studied in Control and PGF(2α)/PMSG/hCG administered animals. WNT7A and CTNNB1 were affected by PGF(2α)/PMSG/hCG treatment in both conceptuses (P < 0.001, P < 0.05) and endometrial tissue (P < 0.001, P < 0.01). The PGF(2α)/PMSG/hCG treatment resulted in elevated expression of WNT4 (P < 0.001) and CTNNB1 (P < 0.05) in luteal tissue in comparison to the Control gilts. Moreover, luteal amount of WNT5A mRNA was higher in PGF(2α)/PMSG/hCG animals in comparison to the Control group (P < 0.05). Presented data show that exogenous hormones administration can affect gene expression in the porcine reproductive tract and embryo.

  7. Effect of estrus synchronization treatment after luteolysis on Holstein heifers as embryo transfer recipients.

    PubMed

    Yoshida, Tatsuyuki; Sato, Taro; Chiba, Koji; Yoshimura, Itaru; Osada, Masahiro; Okada, Konosuke; Furuta, Hiroki; Ohta, Akihiko; Ushijima, Hitoshi

    2012-07-01

    This study was designed to evaluate the effect of estrus synchronization treatments on recipient heifers for embryo transfer (ET). Holstein heifers were separated into the following three groups: (i) an administration of 50 µg GnRH (gonadotropin-releasing hormone) analog was given to heifers at a random stage of the estrus cycle, followed 7 days later by two administrations of 7.5 mg prostaglandin F2 alfa analog (PG) as control; (ii) another administration of 100 µg GnRH was given to the control group at 48 h after the administration of PG as the second GnRH group; and (iii) an administration of 0.75 mg estradiol benzoate (E2) was given to the control group at 24 h after the administration of PG as the E2 group. Each method caused estrus synchronization. Fresh embryos were nonsurgically transferred into the suitable recipients that had a functional corpora lutea (CL) 7 days after estrus. The E2 group showed a significantly higher (P < 0.01) rate of estrus synchronization (98.9%) at 1-3 days after PG administration and the final pregnancy rate of the E2 group (50.6%) was also significantly higher than the other groups (37.1%, P < 0.05 and 30.9%, P < 0.01, respectively). These findings demonstrate that E2 administration 24 h after PG protocol is effective for estrus synchronization of Holstein heifers, thus improving the productivity of ET.

  8. Efficacy of four synchronization protocols on the estrus behavior and conception in native Korean cattle (Hanwoo).

    PubMed

    Lee, Myeung-Sik; Rahman, Md Saidur; Kwon, Woo-Sung; Chung, Hak-Jae; Yang, Boh-Suk; Pang, Myung-Geol

    2013-11-01

    Ineffective estrus detection is the foremost limiting factor in the fertility of farmed cattle worldwide. Failure to detect estrus or erroneous diagnosis of estrus results in great economic losses in Korea each year. This study was carried out in order to comprehensively describe the estrus behaviors and conception rates of different estrus synchronization protocols applied to 40 cycling native Korean cattle (Hanwoo). The cows were grouped into four (n = 10) and treated with the following protocols: (1) Day -15: controlled intravaginal drug-releasing device (CIDR) for 12 days; Day -5: prostaglandin F2α (PGF2α), (2) ovulation synchronization (OVS): Day -15: GnRH; Day -6: PGF2α; Day -4: GnRH, (3) Day -15: progesterone-releasing intravaginal device for 12 days; Day -5: PGF2α; and (4) Day -15: PGF2α; Day -4: PGF2α. Artificial insemination was performed 12 hours after the detection of estrus using frozen-thawed semen. Estrus signs were compared using a charge-coupled device camera (CCDC) and a control method (direct visual observation). The pregnancy of the cows was determined by transrectal ultrasonography at Days 25 to 30 postinsemination. The results indicated that the day of estrus return was significantly earlier using the CCDC method compared with direct visualization (P < 0.05). Mounting of other cows was the most predominant sign of estrus among the flock (P < 0.05), as analyzed using the CCDC. In the OVS group, a lower rate of mounting was observed than in the other three groups. Moreover, significantly fewer estrus behaviors were noticed in the OVS protocol group (P < 0.05). Both first service conception and overall conception rates were significantly higher (P < 0.05) in the CIDR and OVS treatment groups. In conclusion, the CIDR and OVS protocols appear to be the best practice for the synchronization of estrus for reproductive competence through the CCDC in Hanwoo cows. However, CIDR has a practical advantage over OVS with respect to estrus detection

  9. Efficacy of four synchronization protocols on the estrus behavior and conception in native Korean cattle (Hanwoo).

    PubMed

    Lee, Myeung-Sik; Rahman, Md Saidur; Kwon, Woo-Sung; Chung, Hak-Jae; Yang, Boh-Suk; Pang, Myung-Geol

    2013-11-01

    Ineffective estrus detection is the foremost limiting factor in the fertility of farmed cattle worldwide. Failure to detect estrus or erroneous diagnosis of estrus results in great economic losses in Korea each year. This study was carried out in order to comprehensively describe the estrus behaviors and conception rates of different estrus synchronization protocols applied to 40 cycling native Korean cattle (Hanwoo). The cows were grouped into four (n = 10) and treated with the following protocols: (1) Day -15: controlled intravaginal drug-releasing device (CIDR) for 12 days; Day -5: prostaglandin F2α (PGF2α), (2) ovulation synchronization (OVS): Day -15: GnRH; Day -6: PGF2α; Day -4: GnRH, (3) Day -15: progesterone-releasing intravaginal device for 12 days; Day -5: PGF2α; and (4) Day -15: PGF2α; Day -4: PGF2α. Artificial insemination was performed 12 hours after the detection of estrus using frozen-thawed semen. Estrus signs were compared using a charge-coupled device camera (CCDC) and a control method (direct visual observation). The pregnancy of the cows was determined by transrectal ultrasonography at Days 25 to 30 postinsemination. The results indicated that the day of estrus return was significantly earlier using the CCDC method compared with direct visualization (P < 0.05). Mounting of other cows was the most predominant sign of estrus among the flock (P < 0.05), as analyzed using the CCDC. In the OVS group, a lower rate of mounting was observed than in the other three groups. Moreover, significantly fewer estrus behaviors were noticed in the OVS protocol group (P < 0.05). Both first service conception and overall conception rates were significantly higher (P < 0.05) in the CIDR and OVS treatment groups. In conclusion, the CIDR and OVS protocols appear to be the best practice for the synchronization of estrus for reproductive competence through the CCDC in Hanwoo cows. However, CIDR has a practical advantage over OVS with respect to estrus detection.

  10. Effects of timed artificial insemination following estrus synchronization in postpartum beef cattle.

    PubMed

    Malik, A; Wahid, H; Rosnina, Y; Kasim, A; Sabri, M

    2012-01-01

    The objectives of this study were to evaluate estrus response and pregnancy rates resulting from timed artificial insemination (AI) following estrus synchronization using CIDR in postpartum beef cattle. A total of 100 cows were randomly divided into three groups. Groups 1, 2 and 3 were artificially inseminated at 48-50 h (n=30), 53-55 h (n=30) and 58-60 h (n=40) after CIDR removal, respectively. Estrus synchronization was carried out using a CIDR containing 1.38 mg progesterone. All cows were given 2 mg estradiol benzoate, intramuscularly on the day of CIDR insertion (D 0). The CIDR was removed after 8 days and 125 μg of prostaglandin F2α (PGF2α) was injected intramuscularly. One day after CIDR removal all cows were given 1 mg of estradiol benzoate intramuscularly (D 9). Cows were observed visually for estrus after removal of CIDR. Between 30 and 32 days after timed AI, pregnancy was determined using transrectal ultrasonography. The first estrus observation which is approximately 32 h after CIDR removal showed no significant difference (P>0.05) among the three groups. The onset response of estrus after 32 h removal of CIDR was less than 10% in all three groups 6.6% (G1), 6.8% (G2) and 7.3% (G3). Furthermore, percentages of estrus response (D 10) following CIDR removal were 76.6%, 75.0% and 77.5%. The difference between on D 9 and D 10 estrus response were statistically significant (P<0.05). The pregnancy rates were 23.3% (G1), 26.6% (G2) and 37.5% (G3), which were not significant (P>0.05).

  11. Effects of timed artificial insemination following estrus synchronization in postpartum beef cattle

    PubMed Central

    Malik, A.; Wahid, H.; Rosnina, Y.; Kasim, A.; Sabri, M.

    2012-01-01

    The objectives of this study were to evaluate estrus response and pregnancy rates resulting from timed artificial insemination (AI) following estrus synchronization using CIDR in postpartum beef cattle. A total of 100 cows were randomly divided into three groups. Groups 1, 2 and 3 were artificially inseminated at 48-50 h (n=30), 53-55 h (n=30) and 58-60 h (n=40) after CIDR removal, respectively. Estrus synchronization was carried out using a CIDR containing 1.38 mg progesterone. All cows were given 2 mg estradiol benzoate, intramuscularly on the day of CIDR insertion (D 0). The CIDR was removed after 8 days and 125 μg of prostaglandin F2α (PGF2α) was injected intramuscularly. One day after CIDR removal all cows were given 1 mg of estradiol benzoate intramuscularly (D 9). Cows were observed visually for estrus after removal of CIDR. Between 30 and 32 days after timed AI, pregnancy was determined using transrectal ultrasonography. The first estrus observation which is approximately 32 h after CIDR removal showed no significant difference (P>0.05) among the three groups. The onset response of estrus after 32 h removal of CIDR was less than 10% in all three groups 6.6% (G1), 6.8% (G2) and 7.3% (G3). Furthermore, percentages of estrus response (D 10) following CIDR removal were 76.6%, 75.0% and 77.5%. The difference between on D 9 and D 10 estrus response were statistically significant (P<0.05). The pregnancy rates were 23.3% (G1), 26.6% (G2) and 37.5% (G3), which were not significant (P>0.05). PMID:26623282

  12. Estrus synchronization with pseudopregnant gilts induced by a single treatment of estradiol dipropionate.

    PubMed

    Noguchi, Michiko; Yoshioka, Koji; Suzuki, Chie; Arai, Sachiko; Itoh, Seigo; Wada, Yasunori

    2010-08-01

    The aims of this study were to determine whether a single treatment of estradiol dipropionate (EDP) could induce pseudopregnancy in gilts and to determine the effectiveness of PGF(2alpha) treatment on estrus synchronization in EDP-induced pseudopregnant gilts. In experiment 1, gilts were treated with 20 mg of EDP (n=11) or vehicle (n=5) on Day 12 (Day 0=onset of estrus). Establishment of pseudopregnancy was defined as a lack of estrus and maintenance of the plasma progesterone concentration above 1 ng/ml between Days 12 and 36. Nine of 11 gilts (82%) treated with EDP became pseudopregnant. The plasma estradiol-17beta level was significantly higher in the EDP-treated gilts than in the control gilts until Day 29. In experiment 2, PGF(2alpha) was administered twice with a 24-h interval from Day 36 in pseudopregnant gilts (n=6) or Day 10 in cyclic gilts (control; n=5). Estrus after PGF(2alpha) treatment was observed in 83% of the pseudopregnant gilts. The interval from the day of the first PGF(2alpha) treatment to the onset of estrus and the peak of the LH surge was significantly shorter in the pseudopregnant gilts than in the control gilts. In experiment 3, six pseudopregnant gilts were bred by artificial insemination at the estrus after PGF(2alpha) treatment. The farrowing rate and average litter size did not differ between the PGF(2alpha)-treated pseudopregnant and cyclic gilts. These results indicate that a single treatment of EDP on Day 12 of the estrous cycle can induce pseudopregnancy in pigs and that a convenient protocol for administering PGF(2alpha) to EDP-induced pseudopregnant pigs is available for estrus synchronization programs in cyclic pigs.

  13. Determination of anti-Müllerian hormone at estrus during a synchronized and a natural bovine estrous cycle.

    PubMed

    Pfeiffer, K E; Jury, L J; Larson, J E

    2014-01-01

    Anti-Müllerian hormone (AMH) has been correlated with phenotypic indicators of fertility. However, the effects of exogenous hormones used during estrus synchronization on AMH have not been evaluated. Therefore, the objective of this experiment was to determine whether concentrations of AMH at estrus are similar between a synchronized compared with a natural estrous cycle. Nulliparous dairy and beef heifers (n = 68) were synchronized with the Select Synch + controlled internal drug release (CIDR) protocol (GnRH + CIDR-7 d-CIDR removal + PG). Heifers were observed for expression of estrus every 6 h until 84 h after the injection of PG. Visual detection of the subsequent estrus, considered natural estrus, occurred every 6 h from day 16 to 24 after synchronized estrus. At the time of standing estrus, ovarian structures in heifers were evaluated by transrectal ultrasonography. Blood samples were collected at estrus for analysis of concentrations of AMH during the synchronized and natural estrous cycles. The GLM and CORR procedures of SAS were used to analyze data. Concentrations of AMH between natural and synchronized estrus were positively correlated (r = 0.67; P < 0.001). Mean concentration of AMH did not differ (P > 0.05) between the natural (0.0543 ± 0.0076 ng/mL) or synchronized (0.0428 ± 0.0076 ng/mL) estrous cycles. In conclusion, concentrations of AMH were similar between natural and synchronized estrous cycles. Concentrations of AMH in natural and synchronized estrous cycles were highly correlated within individual heifers and varied among heifers with beef heifers having increased (P < 0.05) concentrations of AMH compared with dairy heifers (0.0638 ± 0.01 and 0.0402 ± 0.01 ng/mL, respectively).

  14. Supplementation with rumen-protected L-arginine-HCl increased fertility in sheep with synchronized estrus.

    PubMed

    de Chávez, Julio Agustín Ruiz; Guzmán, Adrian; Zamora-Gutiérrez, Diana; Mendoza, Germán David; Melgoza, Luz María; Montes, Sergio; Rosales-Torres, Ana María

    2015-08-01

    The aim of the present study was to evaluate the effects of L-arginine-HCl supplementation on ovulation rate, fertility, prolificacy, and serum VEGF concentrations in ewes with synchronized oestrus. Thirty Suffolk ewes with a mean body weight of 45 ± 3 kg and a mean body condition score (BCS) of 2.4 ± 0.28 were synchronized for estrus presentation with a progestin-containing sponge (20 mg Chronogest® CR) for 9 days plus PGF2-α (Lutalyse; Pfizer, USA) on day 7 after the insertion of the sponge. The ewes were divided into two groups; i.e., a control group (n = 15) that was fed on the native pasture (basal diet) and an L-arginine-HCl group (n = 15) that received 7.8 g of rumen-protected L-arginine-HCl from day 5 of the sponge insertion until day 25 after mating plus the basal diet. The L-arginine-HCl was administered daily via an esophageal probe between days 5 and 9 of the synchronization protocol and every third day subsequently. Blood samples were drawn from the jugular vein every 6 days throughout the entire experimental period. The results revealed that the L-arginine-HCl supplementation increased fertility during the synchronized estrus (P = 0.05). However, no effects were observed on the final BCS (P = 0.78), estrus presentation (P = 0.33), multiple ovulations (P = 0.24), prolificacy (P = 0.63), or serum VEGF concentration. In conclusion, L-arginine-HCl supplementation during the period used in this study increased fertility in sheep with synchronized estrus possibly due to improved embryo-fetal survival during early pregnancy.

  15. Supplementation with rumen-protected L-arginine-HCl increased fertility in sheep with synchronized estrus.

    PubMed

    de Chávez, Julio Agustín Ruiz; Guzmán, Adrian; Zamora-Gutiérrez, Diana; Mendoza, Germán David; Melgoza, Luz María; Montes, Sergio; Rosales-Torres, Ana María

    2015-08-01

    The aim of the present study was to evaluate the effects of L-arginine-HCl supplementation on ovulation rate, fertility, prolificacy, and serum VEGF concentrations in ewes with synchronized oestrus. Thirty Suffolk ewes with a mean body weight of 45 ± 3 kg and a mean body condition score (BCS) of 2.4 ± 0.28 were synchronized for estrus presentation with a progestin-containing sponge (20 mg Chronogest® CR) for 9 days plus PGF2-α (Lutalyse; Pfizer, USA) on day 7 after the insertion of the sponge. The ewes were divided into two groups; i.e., a control group (n = 15) that was fed on the native pasture (basal diet) and an L-arginine-HCl group (n = 15) that received 7.8 g of rumen-protected L-arginine-HCl from day 5 of the sponge insertion until day 25 after mating plus the basal diet. The L-arginine-HCl was administered daily via an esophageal probe between days 5 and 9 of the synchronization protocol and every third day subsequently. Blood samples were drawn from the jugular vein every 6 days throughout the entire experimental period. The results revealed that the L-arginine-HCl supplementation increased fertility during the synchronized estrus (P = 0.05). However, no effects were observed on the final BCS (P = 0.78), estrus presentation (P = 0.33), multiple ovulations (P = 0.24), prolificacy (P = 0.63), or serum VEGF concentration. In conclusion, L-arginine-HCl supplementation during the period used in this study increased fertility in sheep with synchronized estrus possibly due to improved embryo-fetal survival during early pregnancy. PMID:25991464

  16. Comparison of long-term progestin-based estrus synchronization protocols in beef heifers.

    PubMed

    Mallory, D A; Wilson, D J; Busch, D C; Ellersieck, M R; Smith, M F; Patterson, D J

    2010-11-01

    Two experiments evaluated long-term progestin-based estrus-synchronization programs on the basis of potential for use in facilitating fixed-time AI in estrous cycling and prepubertal beef heifers. In Exp. 1, heifers were assigned to 1 of 2 treatments by age, BW, and estrous cyclicity status. Heifers assigned to the melengestrol acetate-PGF(2α) protocol (MGA-PG; n = 50) received MGA (0.5 mg·animal(-1)·d(-1)) in a 1.0-kg carrier from d 0 to 13 and were administered PGF(2α) (25 mg, intramuscularly) 19 d after MGA withdrawal (d 32). Heifers assigned to the Show-Me-Synch protocol (n = 49) received a controlled internal drug release (CIDR) insert (1.38 g of progesterone) from d 2 to 16 followed by PGF(2α) administration 16 d after CIDR removal (d 32). All heifers were fitted with HeatWatch estrus-detection transmitters at the time of progestin removal for continuous estrus detection through the synchronized period after PGF(2α). In Exp. 2, heifers (n = 396) were assigned to the same 2 treatments described in Exp. 1 by age, BW, and reproductive tract score. Heifers in Exp. 2, however, were fitted with HeatWatch estrus-detection transmitters at PGF(2α) to characterize estrus-distribution patterns during the synchronized period after PGF(2α). Heifers in both experiments were inseminated approximately 12 h after the onset of estrus. In Exp. 1, estrous response after PGF(2α) and mean interval to estrus after PGF(2α) did not differ between MGA-PG and Show-Me-Synch treatments (P = 0.97). The variance for interval to estrus after PGF(2α) tended (P = 0.06) to be reduced among MGA-PG-treated heifers compared with Show-Me-Synch-treated heifers. Conception to AI, AI pregnancy, and final pregnancy rates did not differ (P > 0.1) between treatments. In Exp. 2, estrous response after PGF(2α) was greater (P = 0.01) among Show-Me-Synch-treated heifers (92%) compared with MGA-PG-treated heifers (85%); however, mean interval to estrus after PGF(2α) did not differ (P = 0

  17. Comparison of two methods of synchronization of estrus in brown brocket deer (Mazama gouazoubira).

    PubMed

    Zanetti, Eveline Dos Santos; Polegato, Bruna Furlan; Duarte, José Maurício Barbanti

    2010-02-01

    This study aimed to establish a protocol for synchronization of estrus in brown brocket deer (Mazama gouazoubira). Two groups of hinds (n=3) were submitted to two different protocols: Treatment 1 received an intravaginal progesterone (CIDR) device for 8 days, followed by 265microg injection of cloprostenol at the time of removal; and Treatment 2 received two injections of 265microg of cloprostenol 11 days apart. After 30 days, each group of three hinds received the other treatment. Treatment efficacy was evaluated by reproductive behavior, fecal progestin and estrogen concentration and the observation of CL by laparoscopy 6 days after the end of estrus. All the hinds (100%) had estrous behavior upon the completion of treatment, but a significant difference occurred between the time of onset, 70.5+/-5.0h for Treatment 1 and 52.3+/-5.6h for Treatment 2. The mean estrus duration time (34.7+/-4.50 and 37.0+/-8.11h), ovulation rates (5/6 and 4/6), mean CL size (4.85+/-0.74 and 3.21+/-0.19mm) and mean fecal progestin concentration at 6 days after the end of estrus (865.53+/-76.59 and 1073.35+/-106.82ng/g feces) were not significantly different between treatments. There was no difference in fecal estrogen concentrations throughout the treatment and the greatest values of the estrogen:progestin ratio coincided with estrous behavior. Although fertility was not evaluated directly, both treatments were effective in synchronizing estrus in the species M. gouazoubira, with the formation of functional corpora lutea.

  18. [Synchronization of estrus in heifers using Chlorsuperlutin (CSL) vaginal tampons].

    PubMed

    Zaoral, J; Ríha, J

    1979-08-01

    A pilot experiment with heifer heat synchronization with chlorsuperlutin-soked intravaginal tampons was conducted with 254 heifers in six herds in the North Moravian region. The rubber-foam tampons, cylindrical in shape (diameter 70 mm, height 70-90 mm), were introduced into the cranial part of the vagina, using an applicator and a vaginal speculum. Sixteen days after introduction, the tampons were removed by pulling the silon thread with which the tampons were cross-stitched. The heifers were inseminated on the second to fifth day after the removal of the tampons. The average performance in the application of the tampons was 38.5 tampons per hour, and in their removal 20.7 tampons per hour. The retention rate of the tampons was 97.6%; out of this, 79.8% of the tampons were pulled out by the silon thread. The signs of heat were good, 87.9% of the heifers could be inseminated intrauterinally. All the heifers with retained tampons were inseminated. The conception rate after the first insemination was 32.7%, after the second insemination 56.4%, and after two inseminations 68.1%. Out of the synchronized heifers, 8.1% were culled for slaughter. The drawbacks of this treatment include the low conception rate of the synchronized heifers, a high requirement for repeated insemination in the synchronized oestrus, and, consequently, a high sperm consumption.

  19. Estrous synchronization and fertility in gilts after 14- or 18-day feeding of altrenogest beginning at estrus or diestrus.

    PubMed

    Stevenson, J S; Davis, D L

    1982-07-01

    A synthetic progestogen (altrenogest) was used to synchronize estrus in 160 Yorkshire and Duroc x Yorkshire gilts (6 to 11 mo old) in four trials. Gilts were fed 15 mg altrenogest for 14 or 18 d beginning either at or near estrus (d -1, 0, +1 or +2) or at diestrus (d +3 to +21). Mean intervals to estrus after treatment did not differ between 14- and 18-d treatments (5.4 +/- .1 vs 5.3 +/- .1 d, respectively), but were slightly longer (P less than .01) in gilts beginning treatment at or near estrus than in diestrus (5.6 +/- .1 vs 5.2 +/- .1, respectively). Average intervals to estrus were similar between treatment groups and among stages of the cycle even though more gilts (P less than .01) beginning treatment at estrus had serum progesterone concentrations greater than 2 ng/ml at the end of progestogen treatment. Although more 18- than 14-d treated gilts (P less than .05) were in estrus on d 5 post-treatment, proportions in estrus from 3 to 10 d post-treatment were similar (greater than 98%). Neither stage of estrous cycle at onset of treatment nor duration of progestogen treatment affected percentages of gilts farrowing (greater than 73%), average gestation length (116.5 d), or total (10.3), live (9.7) and dead (.6) pigs at birth after artificial insemination at the post-treatment estrus. We concluded that 14-d feeding of altrenogest effectively synchronized fertile estrus in gilts regardless of stage of estrous cycle at the onset of progestogen treatment. Although 18-d treatment of gilts with altrenogest improved estrous synchronization precision compared to 14-d treatment, there was no advantage of the 18-d treatment for subsequent farrowing responses.

  20. Male-induced estrus synchronization in the female Siberian hamster (Phodopus sungorus sungorus).

    PubMed

    Dodge, James C; Kristal, Mark B; Badura, Lori L

    2002-11-01

    Olfactory cues play an integral role in the organization of events that mediate reproductive success. In a variety of species, priming pheromones, in particular, are important for ensuring reproductive fitness. To date, very little research has focused on how male-emitted priming pheromones, such as those that regulate the onset of puberty and estrus synchronization in females, affect the reproductive physiology of the female Siberian hamster (Phodopus sungorus sungorus). This lack of research may be due to the physiology of the Phodopus genus; vaginal cytology cannot be used as a reliable indicator of estrus or ovulation. Using a jugular cannulation technique to determine estrous stage by blood analysis of prolactin and luteinizing hormone, we sought to determine if male priming pheromones affect estrous cyclicity in the female Siberian hamster and, if so, whether the production of these priming pheromones is androgen dependent. Our results showed that females exposed to bedding from mature, intact males showed a significantly higher incidence of proestrus 3 days later than did females exposed to the bedding of mature, gonadectomized males. Therefore, we found that not only do male Siberian hamsters emit chemical signals that induce estrus synchronization, but also that this ability is likely to be androgen dependent.

  1. Estrus synchronization and fixed-time artificial insemination in sheep under field conditions of a semi-arid tropical region.

    PubMed

    De, Kalyan; Kumar, Davendra; Sethi, Debabrata; Gulyani, Rajiv; Naqvi, Syed Mohammed Khursheed

    2015-02-01

    A study was conducted to assess the success of estrus synchronization and fixed-time artificial insemination (FTAI) in sheep under field conditions of a semi-arid tropical region. A total of 471 ewes belonging to 17 farmers of four villages in Tonk district of Rajasthan (Jelmiya, Dhani Jaisinghpura, Tantiya and Bheepur) were synchronized for estrus during the years 2011 and 2012. Synchronization of estrus was done by AVIKESIL-S, cost-effective intra-vaginal sponges developed by the Institute and eCG protocol. The sponges were kept in situ in the vagina for 12 days and 200 IU eCG (Folligon, Intervet) was administered intramuscularly at the time of sponge withdrawal on the 12th day. Fixed-time cervical insemination was performed twice in ewes exhibiting estrus (restlessness, shaking of tail, slightly swollen vulva, moist and reddish cervical external os), 48 and 56 h after sponge removal, using liquid chilled semen of Patanwadi/Malpura rams containing 100 million sperm per dose. The estrus response recorded was 79.4 % (374/471) and lambing rate was 60.42 % (226/374). It may be concluded from the encouraging results of the present study that FTAI can be used effectively to take advantage of both the genetic improvement and economic benefit that can be realized by the use of estrus synchronization in conjunction with artificial insemination (AI).

  2. Methods to reduce or eliminate detection of estrus in a melengestrol acetate-PGF2alpha protocol for synchronization of estrus in beef heifers.

    PubMed

    Johnson, S K; Day, M L

    2004-10-01

    Three experiments were conducted to evaluate methods to decrease or eliminate the detection of estrus inherent to a melengestrol acetate (MGA)-PGF2alpha (PGF) protocol for synchronization of estrus in heifers. In each experiment, all heifers received 0.5 mg of MGA x animal(-1) x d(-1) for 14 d (d -32 to -19) and PGF (25 mg, i.m.; d 0, 0 h) 19 d after the last feeding of MGA (MGA-PGF protocol). In Exp. 1, heifers (n = 709) were assigned to each of the following protocols: 1) the MGA-PGF protocol with AI 6 to 12 h after detection of estrus (estrus AI; MGA-PGF); 2) MGA-PGF plus 100 microg, i.m. of GnRH on d -7 (1x GnRH) and estrus AI; or 3) MGA-PGF, GnRH on d -7, and GnRH (100 microg, i.m.) at 48 h after PGF, coincident with insemination (2x GnRH-TB48). In Exp. 2, heifers (n = 559) received the MGA-PGF protocol and were inseminated by either estrus AI or fixed-time AI (TAI) at 60 h, coincident with an injection of GnRH (GnRH-TB60). In Exp. 3, all heifers (n = 460) received the MGA-PGF protocol and were inseminated by estrus AI when detected up to 73 h. Heifers not observed in estrus by 73 h received TAI between 76 and 80 h. Half the heifers inseminated by TAI received no further treatment (TB80), and the remaining half was injected with GnRH at insemination (GnRH-TB80). Variance associated with the interval to estrus and the proportion in estrus from d 0 to 5 was similar for 1x GnRH and MGA-PGF treatments in Exp. 1. Pregnancy rate (d 0 to 5) did not differ for the MGA-PGF and 1x GnRH treatments (62.5 and 60.4%, respectively), and both were greater (P < 0.05) than TAI pregnancy rate in the 2x GnRH-TB48 treatment (42.3%). In Exp. 2, the peak estrous response occurred 60 h after PGF. Pregnancy rate during the synchrony period was greater (P < 0.05) for the MGA-PGF (255/401; 63.6%) than the GnRH-TB60 (74/158; 46.6%) treatment. In Exp. 3, 75.7% of heifers (348/460) were detected in estrus by 73 h and were inseminated, with a conception rate of 74.4%. Pregnancy rates after

  3. Short communication: estrus synchronization using progestogens or cloprostenol in tropical hair sheep.

    PubMed

    Alavez Ramírez, Alejandro; Arroyo Ledezma, Jaime; Montes Pérez, Ruben; Zamora Bustillos, Roberto; Navarrete Sierra, Luis Fernando; Magaña Sevilla, Hector

    2014-12-01

    The objective of the experiment was to compare the use of a PGF2α analogue (Cloprostenol) IM, with an intravaginal progestagen sponge, flurogestone acetate (FGA), and equine chorionic gonadotropin (eCG) IM application protocol. A total of 30 cyclical hair ewes (54.07 ± 0.5 kg live weight, body condition score 3.5 ± 0.5, and age 3 ± 1 years) were used. For the control group ewes (n = 15), intravaginal sponges (IS) impregnated with 20 mg of FGA were inserted for 12 days with 500 IU of eCG IM at sponges withdrawal. For the PG group ewes (Treatment group n = 15), two injections of Cloprostenol (75 mcg) were given 12 days apart. The presence of estrus was detected using two rams with 8 h interval beginning at the end of the treatment. Progesterone concentrations in blood were measured by solid phase radioimmunoassay. A student's t test was performed to analyze the duration of estrus and the interval between the ends of the treatment and the onset of estrus (ET-OE) presentation. Progesterone levels were compared with two-way ANOVA, with treatment, and day of menstrual cycle as fixed factors. Treatment costs ratio was calculated by dividing the total costs of FGA IS application between total costs of Cloprostenol application. Significant differences (P < 0.05) were found in the (ET-OE) interval and estrus duration. For the control group, estrus was presented at 30 + 8.2 h; in treatment group, at 44 h after the last application, duration of estrus was 54.9 + 8.34 h, and 41 + 1.83 h for the control and treatment group, pregnancy rates were 53.3 and 60.0 %, respectively. Significant differences (P < 0.001) were found from days 9 to 13 on Progesterone levels in both treatments. Treatment costs of Cloprostenol protocol were 2.63 cheaper than FGA including disposable material, biological products, and labor. It was concluded that Cloprostenol could be an effective tool in estrus synchronization in hair sheep in tropical areas.

  4. The economic effects of an estrus synchronization protocol using prostaglandin in beef heifers.

    PubMed

    Holm, D E; Thompson, P N; Irons, P C

    2008-12-01

    We estimated the effect of estrus synchronization on reproduction, production and economic outcomes in 272 beef heifers randomly allocated to a synchronized Test group or an unsynchronized Control group. The Test group received AI upon estrus detection for 6 days followed by PGF2 treatment of heifers that had not shown estrus by day 6 (PGF/6). In both groups AI was continued for 50 days, followed by a 42-day bull breeding period. Heifers were followed through their second breeding season and until they had weaned their first calves. Synchronization resulted in a reduction in median days to first insemination (8 vs. 11 in the Test and Control groups, respectively, P<0.01) and median days to calving of calves born to AI (14 vs. 20, P=0.04). There was no significant difference in pregnancy rate to the AI period (60.0% vs. 51.8%, P=0.18), final pregnancy rate (82.2% vs. 83.2%, P=0.87) or pregnancy rate to the subsequent breeding season (96.0% vs. 95.0%, P=1.00). Although mean calf weaning mass was not significantly different (207.0 kg vs. 201.4 kg, P=0.32), the total mass of calves weaned in this study was 14,843 kg vs. 13,060 kg and the benefit: cost ratio for synchronization was 2.8. It was therefore concluded that a PGF/6 protocol may affect the total mass of calves weaned by changing days to calving, weaning rate, the ratio of male: female calves born and/or the birth mass of calves.

  5. Effect of the combination of male effect with PGF2α on estrus synchronization of hair sheep in Mexican tropic.

    PubMed

    Alavez-Ramírez, Alejandro; Montes-Pérez, Rubén; Aguilar-Caballero, Armando Jacinto; Ortega-Pacheco, Antonio

    2016-03-01

    The aim of this study was to evaluate the "male effect" at the end of protocol with prostaglandins (PG) on estrus synchronization of hair sheep during breeding season (November-December) in Yucatan, Mexico. Twenty female Pelibuey sheep (weighting 38.2 ± 1.6 kg and body condition score of 2.5 ± 0.5) were randomly distributed in two groups (n = 10). Group T1 (control, PG), two doses of 50 μg of cloprostenol with 12 days between applications were applied; in the second group T2 (PG-ME), ewes received the same PG protocol plus the introduction of a male at the end of treatment. The interval of end treatment-onset of estrus was analyzed using survival test; the number of sheep with presence/absence of estrus was analyzed using Fisher's exact test. Ewes in estrus for groups T1 and T2 were 5 vs. 8, respectively. No significant differences were found as regards the interval end of treatment-onset of estrus (P > 0.05), as well as in total proportion of ewes with estrus and likewise in the duration of it (P > 0.05). We conclude that the protocol based on double dose of PGF2α with interval of 12 days combined with the male effect is efficient to induce luteolysis and estrus synchronization in hair sheep.

  6. Estrus synchronization and fertility behavior in Black Bengal goats following either progesterone or prostaglandin treatment.

    PubMed

    Ishwar, A K; Pandey, J N

    1990-11-01

    Thirty-six Black Bengal female goats were in the study. They were divided into three groups of 12 goats each. Group I served as the control, Group II was treated with progesterone, Group III was administered prostaglandin F2alpha. There was 100% estrus synchronization in the PGF2alpha treated group and 90% in the progesterone treated group. The total number of kids produced in the PGF2 alpha treated group was 15 followed by 12 in the progesterone - treated group and 6 in the control group. The gestation length was found to be similar in all three groups. PMID:16726900

  7. Efficiency of different hormonal treatments for estrus synchronization in tropical Santa Inês sheep.

    PubMed

    Texeira, Tarcísio Alves; da Fonseca, Jeferson Ferreira; de Souza-Fabjan, Joanna Maria Gonçalves; de Rezende Carvalheira, Luciano; de Moura Fernandes, Daniel Andrews; Brandão, Felipe Zandonadi

    2016-03-01

    The aim of this study was to evaluate the effect of (i) the duration of hormone treatment with progestogen sponges during the seasonal anestrus and (ii) the administration of two doses of prostaglandin at 7 days apart during the breeding season on reproductive parameters of Santa Inês ewes. In experiment 1, 32 ewes received intravaginal MAP sponges for 6 (G6 days), 9 (G9 days), or 12 (G12days) days and 75 μg D-cloprostenol i.m. and 300 IU eCG i.m. 1 day before sponge removal. In experiment 2, 23 ewes received two doses of 0.48-mg sodium cloprostenol i.m. 7 days apart. Ovarian follicular dynamic was assessed through transrectal ultrasonography. Blood samples were collected daily to determine progesterone concentrations. In experiment 1, estrus and ovulation rates did not differ (P > 0.05) among protocols and between cyclic and acyclic ewes at the beginning of the experiment. The G9 days treatment showed a lower dispersion of ovulations in relation to onset of estrus when compared to G6 days and G12 days. In experiment 2, all ewes exhibit estrus and ovulated after the second dose of prostaglandin, although ewes that were in diestrus at D0 showed subluteal concentrations of progesterone during the follicle development stage of the treatment. In conclusion, the use of progestogen device during 9 days promotes lower dispersion of ovulation when compared to its use for 6 or 12 days, and the protocol of two doses of prostaglandin 7 days apart synchronizes estrus efficiently but results in follicular development under low progesterone concentrations.

  8. Recent advances in the synchronization of estrus and ovulation in dairy cows.

    PubMed

    Macmillan, Keith L

    2010-01-01

    Synchronization programs have become standard components in the current breeding management of cows in the dairy herds of most dairy industries. Many are based on protocols that allow timed inseminations (TAI) so as to circumvent the practical difficulties associated with estrus detection. These difficulties are exacerbated in modern herds of high producing cows either because of increasing herd size in which individual animal monitoring is difficult and often subjective, or because small intensively managed herds are milked in robotic systems that minimize animal: staff interactions. Additional reasons arise from high producing cows having less obvious symptoms of estrus, partly because of housing systems combined with intensive feeding and milking, partly because of higher metabolic clearance rates of reproductive hormones like estradiol and partly because of the increasing prevalence of prolonged post-partum anestrus and reproductive tract pathology. The most recently developed programs include protocols for resynchronization following first or subsequent inseminations. These re-synchronization protocols may involve selected forms of hormonal intervention during the diestrous and pro-estrous periods following TAI, or following pregnancy diagnosis by ultrasound from 28 days after TAI. The latter form of re-synchronization has become increasingly important with the recognition that late embryonic/early foetal death has become a major factor compromising the reproductive performance of high producing Holstein cows in many dairy industries. Although cows detected in estrus without any hormonal treatment before insemination have higher conception rates than those inseminated following synchronization and TAI, the low detection rates combined with embryonic death means that intervals from calving to conception (days open) are usually less when synchronization programs have been successfully implemented. One of the significant factors affecting a program's success is

  9. Recent advances in the synchronization of estrus and ovulation in dairy cows.

    PubMed

    Macmillan, Keith L

    2010-01-01

    Synchronization programs have become standard components in the current breeding management of cows in the dairy herds of most dairy industries. Many are based on protocols that allow timed inseminations (TAI) so as to circumvent the practical difficulties associated with estrus detection. These difficulties are exacerbated in modern herds of high producing cows either because of increasing herd size in which individual animal monitoring is difficult and often subjective, or because small intensively managed herds are milked in robotic systems that minimize animal: staff interactions. Additional reasons arise from high producing cows having less obvious symptoms of estrus, partly because of housing systems combined with intensive feeding and milking, partly because of higher metabolic clearance rates of reproductive hormones like estradiol and partly because of the increasing prevalence of prolonged post-partum anestrus and reproductive tract pathology. The most recently developed programs include protocols for resynchronization following first or subsequent inseminations. These re-synchronization protocols may involve selected forms of hormonal intervention during the diestrous and pro-estrous periods following TAI, or following pregnancy diagnosis by ultrasound from 28 days after TAI. The latter form of re-synchronization has become increasingly important with the recognition that late embryonic/early foetal death has become a major factor compromising the reproductive performance of high producing Holstein cows in many dairy industries. Although cows detected in estrus without any hormonal treatment before insemination have higher conception rates than those inseminated following synchronization and TAI, the low detection rates combined with embryonic death means that intervals from calving to conception (days open) are usually less when synchronization programs have been successfully implemented. One of the significant factors affecting a program's success is

  10. Cloprostenol and pregnant mare serum gonadotropin promote estrus synchronization, uterine development, and follicle-stimulating hormone receptor expression in mice.

    PubMed

    Wei, S; Gong, Z; An, L; Zhang, T; Dai, H; Chen, S

    2015-06-29

    This study investigated the effects of pregnant mare se-rum gonadotropin (PMSG) and cloprostenol (CLO) on estrus induc-tion and synchronization, uterine development, and follicle-stimulating hormone receptor (FSHR) expression in mice. A total of 105 Kunming pre-puberty mice were divided into seven subgroups. Three PMSG sub-groups were injected intraperitoneally with 10, 20, and 40 IU PMSG twice (on days 0 and 4), and three CLO subgroups were injected intra-peritoneally with 10, 15, and 20 μg cloprostenol acetate twice (on days 0 and 4). The results showed that 93.33 and 66.67% of synchronized mice displayed estrus within 18.68-37.59 h following CLO and PMSG exposure, respectively. Estrus numbers, estrus onset time, and estrus rates in CLO and PMSG groups were greater than in control groups (CG) (P < 0.05). Uterine weights of the PMSG group were higher than that of CLO and CG groups, and the uterine horn longitudinal diameters in experimental mice were greater than CG. Expression levels of FSHR proteins in CLO and PMSG groups increased slightly when compared to CG. In conclusion, CLO and PMSG administration did not clearly af-fect the expression of uterine FSHR proteins in mice. Moreover, PMSG and CLO treatments synchronized estrus and enhanced the uterine de-velopment of mice. The efficacy of CLO on estrus synchronization was greater than PMSG, and the effects of PMSG on uterine development were stronger than CLO. These results have important significance re-garding the modulation of animal reproductive functions.

  11. Different influence of ovine estrus synchronization treatments on caruncular early angiogenesis.

    PubMed

    Ruiz-González, I; Sánchez, M A; García-Fernández, R A; García-Palencia, P; Sánchez, B; González-Bulnes, A; Flores, J M

    2013-03-01

    The present study compares two protocols for ovine estrus synchronization by assessing the caruncular angiogenic response to the establishment of pregnancy. The analysis consisted of the immunohistochemical evaluation of Vascular Endothelial Growth Factor (VEGF), Platelet Endothelial Cell Adhesion Molecule-1 (PECAM-1, CD31) and Von Willebrand Factor (vWF) in ovine caruncular stroma. A flock of thirty-eight adult ewes was divided in two groups and synchronized with either progestagens (Group P) or prostaglandin analogues (Group PG). Immunohistochemistry was performed in uterine samples obtained from pregnant ewes (P, n=15; PG, n=13) on days 15 post coitus (pc), 17pc and 21pc (day 0 =day of estrus). Each factor was assessed by total vascular density (TVD, total positive blood vessels/mm2), capillary vascular density (CVD, positive blood capillaries/mm2) and arteriolar vascular density (AVD, positive arterioles/mm2). Group P demonstrated higher VEGF-CVD (P=0.045) when compared to prostaglandin treated animals. Vascular CD31-expression decreased on days 15pc and 21pc (TVD, P=0.007 and CVD, P=0.014) in both groups. vWF analysis did not show significant differences between groups or days of study. These results demonstrate a different influence of progestagen-based and prostaglandin analogues-based synchronization treatments over VEGF vascular expression during caruncular development taking place in response to pregnancy establishment. In addition, observations pointed out in this study support the involvement of CD31 in the angiogenic stimulus that occurs during early maternal placentation in the ewe.

  12. Efficacy of Heatsynch protocol for induction of estrus, synchronization of ovulation and timed artificial insemination in yaks (Poephagus grunniens L.).

    PubMed

    Sarkar, M; Sengupta, D H; Bora, B Dutta; Rajkhoa, J; Bora, S; Bandopadhaya, S; Ghosh, M; Ahmed, F A; Saikia, P; Mohan, Krishna; Prakash, B S

    2008-03-01

    The objective of this study was to test the efficacy of induction of estrus, synchronization of ovulation and timed artificial insemination in anestrous yaks using the Heatsynch protocol. In Experiment 1, 10 anestrous yaks were administered an analogue of gonadotropin releasing hormone (GnRH) followed by prostaglandin (PG)F2alpha 7 days later and then estradiol cyponate (ECP) 24 h after that. Ovulation was detected by rectal palpation at 2h intervals beginning at the initial signs of estrus. Blood samples were collected at 2h intervals beginning at the time of ECP injection up to 2h after the occurrence of ovulation for the determination of LH and progesterone. All the animals responded to the Heatsynch protocol with expression of estrus and synchronization of ovulation. The mean time interval from the ECP injection to ovulation was 59.4+/-2.62 h (range 50-72 h). The interval from the LH peak to ovulation was 30.2+/-2.3 h. The high degree of synchrony in ovulation could be attributed to the synchrony in the timing of LH peaks. In Experiment 2, 10 anestrous yaks were treated with the Heatsynch protocol (as in Experiment 1) and TAI was performed at 48 and 60 h after the ECP treatment. Concurrently, 16 cycling yaks were inseminated approximately 12 h after detection of spontaneous estrus. Pregnancy rates were similar in both groups, 40% for TAI and 43.75% for yaks inseminated following spontaneous estrus (p>0.05). From this study, two conclusions can be drawn. First, the Heatsynch protocol can be successfully used to induce and synchronize estrus in anestrous yaks and, second, ovulation following the Heatsynch protocol is synchronized adequately to permit the use of fixed time AI in this species.

  13. Estrus response and follicular development in Boer does synchronized with flugestone acetate and PGF2α or their combination with eCG or FSH.

    PubMed

    Bukar, Muhammad Modu; Yusoff, Rosnina; Haron, Abd Wahid; Dhaliwal, Gurmeet Kaur; Khan, Mohd Azam Goriman; Omar, Mohammed Ariff

    2012-10-01

    The effects of different estrus synchronization techniques on follicular development and estrus response were studied in 81 nulliparous Boer does. The does were divided into nine groups. Eight of the nine groups were synchronized with prostaglandin F2-alpha (PGF(2α)) or flugestone acetate (FGA) or their combinations, and the ninth group was a control group. In addition to the above combinations, four of the eight synchronized groups were given 5 mg follicle-stimulating hormone (FSH) and the remaining four groups were administered 300 IU equine chorionic gonadotrophin (eCG). Posttreatment follicular development was monitored until ovulation occurred using a real-time B-mode ultrasound scanner (Aloka, 500 SSD, Japan), with a 7.5-MHz transrectal linear probe. All the does from the synchronized groups that were given eCG exhibited oestrus while only 88.9% of the does synchronized with FSH showed estrus. The estrus response was observed to be the least among the does synchronized with PGF(2α) + FSH (33.3%) combination followed closely by the FGA + FSH (42.9%) combinations. It was observed that the combinations of FGA + PGF(2α) + FSH resulted in increased percentage of estrus response, duration of estrus, and ovulation. The number of follicles was higher (P < 0.05) in FSH-synchronized groups than the eCG-synchronized groups. It was concluded that the best estrus synchronization protocol in goats is the FGA + eCG with or without PGF(2α). However, the PGF(2α) + FGA + FSH method of estrus synchronization is the most promising combination for further development as a better alternative to estrus synchronization with eCG in does.

  14. Administration of Luteinizing Hormone Releasing Hormone Agonist for Synchronization of Estrus and Generation of Pseudopregnancy for Embryo Transfer in Rats

    PubMed Central

    Borjeson, Tiffany M; Pang, Jassia; Fox, James G; García, Alexis

    2014-01-01

    In the past decade, the use of genetically engineered rats has increased exponentially; therefore, the ability to perform embryo transfer (ET) in rats to rederive, reanimate, or create mutant rat lines is increasingly important. However, the successful generation of pseudopregnant female rats for ET represents a limiting factor. We here evaluated the subcutaneous administration of 40 µg luteinizing hormone releasing hormone agonist (LHRHa) for estrus synchronization during the development and implementation of a rat ET program. Our first experiment assessed endogenous estrus cycling patterns by examining vaginal cytology without administration of LHRHa in 5-wk-old peripubertal Sprague–Dawley female rats. These rats then received LHRHa at approximately 7 wk of age; 57% of the rats were synchronized in proestrus or estrus as assessed by vaginal cytology 96 h later. In a second experiment, 8-wk-old virgin, unmanipulated Sprague–Dawley female rats received LHRHa; 55% were synchronized in proestrus or estrus 96 h later. Copulatory plugs were confirmed in 28% and 82% of the rats that had been synchronized in the first and second experiments, respectively, and mated with vasectomized male rats. Embryo transfer surgery was performed, and live pups were born from both fresh and cryopreserved transgenic rat embryos. Our results indicate that subcutaneous administration of 40 µg LHRHa followed by examination of vaginal cytology 96 h later is an effective technique to generate multiple pseudopregnant recipient rats for use in an ET program. PMID:24827564

  15. Administration of luteinizing hormone releasing hormone agonist for synchronization of estrus and generation of pseudopregnancy for embryo transfer in rats.

    PubMed

    Borjeson, Tiffany M; Pang, Jassia; Fox, James G; García, Alexis

    2014-05-01

    In the past decade, the use of genetically engineered rats has increased exponentially; therefore, the ability to perform embryo transfer (ET) in rats to rederive, reanimate, or create mutant rat lines is increasingly important. However, the successful generation of pseudopregnant female rats for ET represents a limiting factor. We here evaluated the subcutaneous administration of 40 μg luteinizing hormone releasing hormone agonist (LHRHa) for estrus synchronization during the development and implementation of a rat ET program. Our first experiment assessed endogenous estrus cycling patterns by examining vaginal cytology without administration of LHRHa in 5-wk-old peripubertal Sprague-Dawley female rats. These rats then received LHRHa at approximately 7 wk of age; 57% of the rats were synchronized in proestrus or estrus as assessed by vaginal cytology 96 h later. In a second experiment, 8-wk-old virgin, unmanipulated Sprague-Dawley female rats received LHRHa; 55% were synchronized in proestrus or estrus 96 h later. Copulatory plugs were confirmed in 28% and 82% of the rats that had been synchronized in the first and second experiments, respectively, and mated with vasectomized male rats. Embryo transfer surgery was performed, and live pups were born from both fresh and cryopreserved transgenic rat embryos. Our results indicate that subcutaneous administration of 40 μg LHRHa followed by examination of vaginal cytology 96 h later is an effective technique to generate multiple pseudopregnant recipient rats for use in an ET program.

  16. The effect of estrus synchronization treatments on somatic cell count of transitional-anestrus Awassi ewes' milk.

    PubMed

    Talafha, A Q; Lafi, S Q; Ababneh, M M

    2009-02-01

    Fifty-three transitional-anestrus Awassi ewes, randomly assigned to three groups: fluorogestone acetate (FGA, n = 18), FGA-Prostaglandin (FGA-PGF, n = 18) and control (n = 17), were used to examine the effect of estrus synchronization protocols and steroid hormones concentrations on milk somatic cell count (SCC). Intravaginal FGA sponge was inserted for 13 days and 600 IU equine chorionic gonadotropin was administered for ewes of FGA and FGA-PGF groups at the time of sponge removal (day 0). In addition, 10 mg was administered to ewes of FGA-PGF group on day 0. Blood and milk samples were collected from all ewes on days -13, -6, 0, 1, 2, 7 and 14. Estradiol had significant positive correlation with the SCC during the periods of sponge insertion (P = 0.015, r = 0.235) and within two days (P = 0.063 r = 0.23) after sponge removal with no correlation with SCC of both udder halves during the luteal phase. Progesterone concentrations, on the other hand, had a significant positive correlation (P < 0.001; r = 0.420) with the SCC of both udder halves during the luteal phase of the experiment, but not during the periods of sponge insertion and expected estrus. SCC returned under the influence of endogenous progesterone on days 7 and 14 to pre-synchronization values. In conclusion, sheep milk SCC is affected significantly with induction of estrus and steroid hormones concentrations. However, peak SCC recorded during estrus was far below the upper limit of the current standard for normal milk. With the current standards for SCC of 1,000,000/ml as legal limit for abnormal milk control programs in sheep, estrus synchronization programs and the estrus status should not be considered when bulk-tank milk SCC is being investigated, but should be considered during the process of setting new standards.

  17. Effects of progestagen exposure duration on estrus synchronization and conception rates of crossbreed ewes undergoing fixed time artificial insemination.

    PubMed

    Blaschi, Wanessa; Lunardelli, Paula A; Marinho, Luciana S R; Max, Marilu C; Santos, Gustavo M G; Silva-Santos, Katia C; Melo-Sterza, Fabiana A; Baldassarre, Hernan; Rigo, Thales R; Seneda, Marcelo M

    2014-01-01

    Synchronization of estrus and ovulation are of paramount importance in modern livestock improvement programs. These methods are critical for assisted reproduction technologies, including artificial insemination and embryo transfer, that can increase productivity. In the current study, subcutaneous implants containing norgestomet were placed for long (14 days), medium (9 days), and short (5 days) periods of time in 70 crossbred ewes undergoing fixed-time artificial insemination. The resulting effects on estrus synchronization and conception rates were subsequently evaluated. Among the synchronized ewes, 85.7% (60/70) underwent estrus over a period of 72 h after progestagen treatment ceased. The shortest mean interval between withdrawal of the device and onset of estrus (34.2 ± 8.9 h) was observed in the G14 days of P4 group (p < 0.05). The conception rate of the G14 days of P4 group was statistically higher than that of the other groups (83.3% vs. 60.9% vs. 47.8%; p < 0.05). In conclusion, 14 days of norgestomet treatment produced higher conception rates and a greater number of pregnancies at the beginning of the breeding season.

  18. Estrus synchronization and conception rate after a progesterone releasing intravaginal device (PRID) treatment from the early luteal phase in heifers.

    PubMed

    Kuroiwa, Takenobu; Ishibashi, Ai; Fukuda, Masaharu; Kim, Seungjoon; Tanaka, Tomomi; Kamomae, Hideo

    2005-10-01

    The objective of the present study was to evaluate estrus synchronization and conception rate after progesterone releasing intravaginal device (PRID) treatment from the early luteal phase in the presence or absence of estradiol benzoate (EB) in heifers. Heifers (n=11) were assigned randomly to two treatments; insertion of a PRID containing 1.55 g progesterone with a capsule attached including 10 mg EB (P+EB; n=6) and the PRID withdrawn the EB capsule (P-EB; n=5). The PRID was inserted into the vagina on Day 2 of the estrous cycle (Day 0 was the day of ovulation) and was left for 12 days. The proportion of heifers exhibiting standing estrus within 3 days after PRID removal was 83.3% (5/6) for the P+EB group, and 80.0% (4/5) for the P-EB group, respectively. Conception rate by artificial insemination on synchronized estrus was 80.0% (4/5) in the P+EB group, and 100% (4/4) in the P-EB treatment group, respectively. These results suggest that a PRID treatment from 2 days after ovulation for 12 days in the presence or absence of EB has an effect on the synchronization of estrus and produces a beneficial conception rate in heifers.

  19. Differences between Brahman and Holstein cows in response to estrus synchronization, superovulation and resistance of embryos to heat shock.

    PubMed

    Krininger, C E; Block, J; Al-Katanani, Y M; Rivera, R M; Chase, C C; Hansen, P J

    2003-09-15

    Embryos from Bos indicus are more resistant to elevated culture temperature (i.e. heat shock) than embryos from some Bos taurus breeds. The present experiment was designed to determine if Brahman embryos have greater resistance to heat shock than Holstein embryos at a stage in development before the embryonic genome was fully activated. A second objective was to test breed effects on estrus synchronization and superovulation responses. A total of 29 Brahman and 24 Holstein cows were subjected to estrus synchronization using gonadotropin releasing hormone (GnRH) and prostaglandin F2alpha (PGF2alpha) superovulation. Embryos were collected at 48 h and day 5 after insemination. There was a tendency for a lower proportion of Brahmans to be detected in standing estrus than Holsteins. There were no differences between breeds in the proportion of cows detected in estrus using both tailpaint and standing estrus as criteria or in interval from PGF2alpha to estrus. The degree of synchrony in estrus was greater for Brahmans. Superovulation response was generally similar between breeds. At 48 h after insemination, there was a tendency for a greater proportion of Brahman oocytes to have undergone cleavage. Uncleaved oocytes were cultured for an additional 24 h-at this time, cleavage rate was similar between breeds. When embryos reached the 2-4-cell stage, they were heat-shocked for 4.5 h at 41 degrees C. This heat shock reduced the proportion of embryos that developed to the blastocyst stage but there was no breedxtreatment interaction. At day 5 after insemination, the number of embryos recovered was too low to allow comparison of breed effects. In conclusion, genetic effects on cellular thermotolerance that make Brahman embryos more resistant to heat shock are not expressed at the 2-4-cell stage. There were few differences between Brahman and Holstein in response to estrus synchronization and superovulation. The fact that cleavage tended to occur earlier in Brahman than

  20. Peripheral serum progesterone and luteinizing hormone concentrations of goats during synchronization of estrus and ovulation with prostaglandin F2 alpha.

    PubMed

    Ott, R S; Nelson, D R; Hixon, J E

    1980-09-01

    Prostaglandin F2 alpha (PGF2 alpha) (2 doses, 11 days apart) was given to 20 mixed-breed dairy does to synchronize estrus and ovulation. The dose of PGF2 alpha used was the free-acid equivalent of 8 mg which was divided between 2 injections at 0800 and 1200 hours. At the initiation of treatments, does were from day 0 (estrus) to day 18 of the estrous cycle. Seventeen of the doses exhibited estrus within a mean (+/- SE) interval of 53 +/- 2 hours after the first 0800-hour injection. Peripheral progesterone concentrations determined at daily intervals indicated that PGF2 alpha was luteolytic as early as day 4 of the cycle. Does were in the 8th to 12th days of the cycle at the time of the 2nd treatments with PGF2 alpha. Estrus was observed in all 20 does at 50 +/- 1 hour after the 0800-hour injections. Serum progesterone concentrations confirmed that luteolysis occurred in all of the does. In 19 does, concentrations of luteinizing hormone characteristic of a preovulatory peak were observed 55 +/- 2 hours after the 2nd 0800-hour injection. One doe did not demonstrate a luteinizing hormone peak within the 72-hour period. Laparotomies were performed 6 days after estrus, and ovaries were examined for corpora lutea. The mean number of corpora lutea was 2.0 +/- 1.0. PMID:7192524

  1. Comparative efficacy of different estrus synchronization protocols on estrus induction response, fertility and plasma progesterone and biochemical profile in crossbred anestrus cows

    PubMed Central

    Dhami, A. J.; Nakrani, B. B.; Hadiya, K. K.; Patel, J. A.; Shah, R. G.

    2015-01-01

    Aim: To evaluate estrus induction response and fertility including plasma progesterone and biochemical profile following use of three standard hormonal protocols in anestrus crossbred cows. Materials and Methods: The study was carried out on 40 true anestrus and 10 normal cyclic cows. 10 anestrus cows each were treated with standard intravaginal controlled internal drug release (CIDR) device, Ovsynch (GPG) protocol, and Norgestomet ear implant with fixed-time artificial insemination (FTAI). 10 anestrus cows were kept as untreated control while 10 cows exhibiting the first estrus within 90 days postpartum without any treatment served as normal cyclic control. Blood samples were obtained from treated cows on day 0, 7, 9 (AI) of treatment and day 21 post-AI, and from control groups on the day of AI and day 21 post-AI for estimation of plasma progesterone, protein, cholesterol, calcium, and inorganic phosphorus profile. Results: The use of CIDR, Ovsynch, and Norgestomet ear implant protocols resulted in 100% estrus induction with conception rates at induced estrus of 60%, 50%, and 50%, and the overall of three cycles as 80%, 80%, and 70%. In untreated anestrus control (n=10), only three cows exhibited spontaneous estrus within 90 days of follow-up and conceived giving the first service and overall conception rates of 66.66% and 30.00%, respectively. In normal cyclic control (n=10), the conception rates at first and overall of three cycles were 50% and 80%. The overall mean plasma progesterone (P4) concentrations in anestrus cows studied on day 0 (initiation), 7 (prostaglandin injection and/or removal of implant), 9 (FTAI) of treatment and on day 21 post-AI revealed that the values on day 7 and 21 were significantly (p<0.01) higher than other two periods in all three groups. The concentrations were significantly (p<0.05) higher in conceived than non-conceived group on day 21 post-AI in CIDR (4.36±0.12 vs. 1.65±0.82 ng/ml) and Ovsynch (4.85±0.62 vs. 1.59±0.34 ng

  2. Effect of estrus synchronization on daily somatic cell count variation in goats according to lactation number and udder health status.

    PubMed

    Mehdid, A; Díaz, J R; Martí, A; Vidal, G; Peris, C

    2013-07-01

    Two repeated experiments were carried out in 2 different years to study the effect of estrus on somatic cell count (SCC) in dairy goats. In the first year, 36 Murciano-Granadina goats were used [12 primiparous and 24 multiparous; 22 healthy and 14 with an intramammary infection (IMI)] and, after a 6-d pre-experimental period, were divided into 2 groups according to lactation number, udder health status, SCC, and milk production. One group was kept as a control, whereas the other received an estrus synchronization hormonal treatment lasting 11d. At 24, 48, and 72h after cessation of the hormone treatment, goats were placed in contact with a buck to confirm that they were in estrus. For 32 consecutive days (6 pre-experimental, 11 in hormone treatment, and 15 post-treatment) the SCC per gland and udder were monitored in all animals. In the second year, we repeated the same experimental design using a total of 38 Murciano-Granadina breed goats (12 primiparous and 26 multiparous; 26 healthy and 12 with IMI). Throughout this experiment, milk yield and composition were also recorded daily for each goat. Upon termination of the hormonal treatment, the SCC in udder milk increased significantly in the treatment group compared with the control group over 3 consecutive days. This increase was observed for year (1 and 2), parity (primiparous and multiparous), and udder health status (healthy and IMI). The log10 SCC (cells/mL) increased from 5.5±0.09 before estrus to 6.04±0.09 during treatment; therefore, the geometric mean of the SCC increased 3.5 times during treatment. The maximum values obtained in healthy glands of primiparous goats (geometric mean=0.37 million cells/mL) were lower than in healthy glands (1.1 million cells/mL) or infected glands (1.7 million cells/mL) of multiparous goats. The increase in SCC observed during estrus (200% increase in geometric means) could not be explained by the changes in milk production, which only fell by 13%. During estrus, the

  3. Effect of estrus synchronization protocols on plasma progesterone profile and fertility in postpartum anestrous Kankrej cows.

    PubMed

    Bhoraniya, Haresh Laljibhai; Dhami, Arjunbhai J; Naikoo, Mehrajuddin; Parmar, Bhupendra C; Sarvaiya, Nareshbhai P

    2012-08-01

    The study was aimed at induction/synchronization of estrus in postpartum anestrous Kankrej cows of zebu cattle maintained at an organized farm. The study included use of different hormone protocols, viz., Ovsynch, CIDR (controlled internal drug release), Ovsynch plus CIDR, and Heatsynch with estimation of plasma progesterone on days 0, 7, 9/11 (artificial insemination--AI) and on day 20 post-AI following fixed time insemination. Thirty selected anestrous animals were divided into five equal groups (four treatment and one control), and the findings were compared with the normal cyclic control group of six cows. All the protocols were initiated in cows with postpartum anestrous period of more than 4 months, considering the day of first GnRH injection or CIDR insertion as day 0. The animals were bred by fixed time artificial insemination. Pregnancy was confirmed per rectum on day 60 post-AI in non-return cases. The conception rates at induced/first heat in Ovsynch, CIDR, Ovsynch + CIDR, and Heatsynch protocols were 33.33, 66.66, 50.00 and 16.67%, respectively. The corresponding overall conception rates of three cycles post-treatment were 50.00% (3/6), 100.00% (6/6), 66.66% (4/6), and 50.00% (3/6). In normal cyclic and anestrous control groups, the pooled pregnancy rates were 83.33% (5/6) and 16.67% (1/6), respectively. The pooled mean plasma progesterone (nanograms per milliliter) concentrations were significantly (P < 0.05) higher on day 7 in Ovsynch (5.727 ± 1.26), CIDR (4.37 ± 0.66), Ovsynch plus CIDR (3.55 ± 0.34), and Heatsynch (5.92 ± 1.11) protocols as compared with their corresponding values obtained on days 0, 9/11 (AI), and on day 20 post-AI. In anestrous control group, the mean progesterone concentration at the beginning of experiment was 0.67 ± 0.33 ng/ml, which was at par with values of all other groups. The overall plasma progesterone levels on the day of initiating treatment were low in all groups, with smooth small inactive ovaries palpated per

  4. Pregnancy rate in dairy cows treated with progesterone for six days during estrus synchronization with PGF2α.

    PubMed

    Orozco, M; Gutiérrez, C G; López, R; Aguilar, C; Roque, C; Hernández-Cerón, J

    2016-03-01

    The present study evaluated the effect of progesterone supplementation during a double PGF2α injection synchronization protocol on pregnancy per artificial insemination (P/AI) and on the incidence of twin births. Seven hundred and eighty three dairy cows were synchronized with two injections of PGF2α 14 days apart, starting on day 35 postpartum for their first postpartum insemination. Six days before the second PGF2α injection, cows were treated either with a progesterone-releasing intravaginal device (PRID-Delta) and an intramuscular injection of 500mg of progesterone (n=387) or served as control (n=396) and did not receive progesterone treatment. Cows were inseminated 12h after being detected in estrus. Pregnancy was diagnosed 40-45 days later by transrectal palpation. Progesterone administration improved (P<0.05) the percentage of cows detected in estrus in multiparous [(192/255) 75% vs (161/267) 60%], but not in primiparous cows [93/132 (70%) vs 90/129 (70%)]. Progesterone treatment increased P/AI in multiparous [53/192 (28%) vs 27/161 (17%)] but not in primiparous cows [25/93 (27%) vs 29/90 (32%)]. The incidence of twin births tended to be lower (P=0.09) in cows treated with progesterone [1/74 (1%)] than in the control group [4/53 (7%)]. It is concluded that progesterone administration during estrus synchronization with two PGF2α injections in dairy cows improves estral response and increases P/AI in multiparous, but not in primiparous cows, and tended to decrease the incidence of twin births.

  5. Use of intravaginal progesterone-releasing inserts in a synchronization protocol before timed AI and for synchronizing return to estrus in Holstein heifers.

    PubMed

    Rivera, H; Lopez, H; Fricke, P M

    2005-03-01

    Holstein heifers (n = 189) were submitted to a 42-d artificial insemination (AI) period in which they underwent AI after once-daily evaluation of rubbed tail chalk. At the onset of the AI period (d 0), heifers were assigned randomly to receive synchronization of ovulation and timed AI (TAI; d 0: 100 mug of GnRH; d 6: 25 mg of PGF(2alpha); d 8: 100 mug of GnRH + TAI) either without (GPG; n = 95), or with inclusion of a CIDR insert (CIDR; n = 94) from d 0 to 6. No CIDR heifers received AI before d 8 compared with 24% of GPG heifers, and pregnancy rate per AI (PR/AI) at 30 d after TAI did not differ between treatments. To synchronize return to estrus for heifers failing to conceive after TAI, heifers (n = 166) receiving TAI to first service were randomly assigned to receive no further treatment (control; n = 85) or receive a new CIDR insert between 14 and 20 d after TAI (Resynch; n = 81). No Resynch heifers received AI during CIDR treatment compared with 35% of control heifers, and the proportion of heifers receiving AI within 72 h after the day of CIDR removal was 78 vs. 50% for Resynch vs. control heifers, respectively. No treatment x inseminator interaction was detected at first or second AI; however, overall PR/AI was modest for heifers throughout the experiment due to poor performance of 2 of the 3 herd inseminators (14, 6, and 58% PR/AI, respectively). Inclusion of CIDR inserts suppressed estrus during the TAI protocol with no reduction in PR/ AI. Resynchronization of estrus using CIDR inserts resulted in tighter synchrony of estrus among nonpregnant heifers compared with untreated controls. PMID:15738230

  6. Estrus synchronization in sheep and goats using combinations of GnRH, progestagen and prostaglandin F2alpha.

    PubMed

    Titi, H H; Kridli, R T; Alnimer, M A

    2010-08-01

    The objective of this experiment was to evaluate the effect of GnRH, progestagen and prostaglandin F(2alpha) on estrus synchronization in sheep and goats. Sixty Awassi ewes and 53 Damascus does were used in the study. The experiment started at the beginning of the breeding season (June/July). The same treatments were applied to sheep and goats as follows: no treatment (CON), 14-day progestagen sponges and 600 IU equine chorionic gonadotropin (S), gonadotropin releasing hormone followed 5 days later by prostaglandin F(2alpha) (GP) and gonadotropin releasing hormone, progestagen sponges for 5 days and prostaglandin F(2alpha) on the day of sponge removal (GSP). None of the ewes in the S group lambed from mating during the induced cycle. A greater lambing rate (p < 0.05) was observed in the GSP group compared with the CON and S groups while the GP group was intermediate. The number of lambs born per lambed ewe was similar among the CON, GP and GSP groups. However, the number of lambs per exposed ewe was greater (p < 0.05) in the GSP than the remaining groups. The induced cycle kidding rate was 77% for all treatments combined. Similar kidding rate were observed among treatments. The numbers of kids born per kidded and exposed doe from mating during the induced estrus were also similar among treatments. Greater numbers of multiple births were observed in the GP and GSP than in the S group. In conclusion, a combination of GnRH, progestagen sponges and PGF(2alpha) can be effective in synchronizing estrus and improving fecundity in sheep and goats. Although the use of GnRH-PGF(2alpha) was effective, the addition of progestagen sponges at the time of GnRH administration appeared to improve reproductive parameters.

  7. In vitro assessment of progesterone and prostaglandin e(2) production by the corpus luteum in cattle following pharmacological synchronization of estrus.

    PubMed

    Skarzynski, Dariusz Jan; Siemieniuch, Marta Jolanta; Pilawski, Wojciech; Woclawek Potocka, Izabela; Bah, Mamadou Moussa; Majewska, Magdalena; Jaroszewski, Jerzy Jan

    2009-04-01

    We studied the secretory function of the corpus luteum (CL) in cows following different estrus synchronization protocols. Estrus was synchronized using one (n=4) or two injections (n=5) of prostaglandin F(2alpha) (PGF(2alpha); dinoprost), two injections of different analogues of PGF(2alpha) (aPGF(2alpha)), luprostiol (n=5) and cloprostenol (n=5), at eleven-day intervals, a gestagen implant (norgestomet, n=5, for 10 days) or norgestomet together with a subsequent dinoprost injection on the day of implant removal (n=5). CL samples were collected by ovariectomy on Day 7-8 of the estrous cycle. Luteal strips were stimulated with LH (100 ng/ml) or prostaglandin E(2) (PGE(2), 10(-6)M) for 24 h in culture media. The progesterone (P(4)) and PGE(2) concentrations in the media were measured by enzyme immunoassay. In the control CL (spontaneous estrus; n=5), LH and PGE(2) stimulated P(4) and PGE(2) (P<0.001). The effects of both factors on P(4) were reduced in the CL following dinoprost- and cloprostenol-synchronized estrus (P<0.05) and were absent in the luprostiol-synchronized CL (P>0.05). In the norgestomet-synchronized CL, the stimulatory effects of LH and PGE(2) were higher compared with the CL synchronized by aPGF(2alpha) (P<0.05). Pharmacological manipulation of the estrous cycle using aPGF(2alpha) may cause lower P(4) secretion. Estrus synchronization inhibited CL sensitivity to luteotropic factors. Therefore, attention should be focused on the estrous synchronization method in both in vivo and in vitro studies of CL functions in cattle.

  8. Estrus synchronization in beef heifers with progestin-based protocols. I. Differences in response based on pubertal status at the initiation of treatment.

    PubMed

    Wood-Follis, S L; Kojima, F N; Lucy, M C; Smith, M F; Patterson, D J

    2004-11-01

    Two progestin-based protocols for estrus synchronization in replacement beef heifers were compared on the basis of estrous response, interval to and synchrony of estrus, and pregnancy rate. The objective was to determine, whether addition of GnRH to a melengestrol acetate (MGA)-prostaglandin F2alpha (PGF2alpha) estrus synchronization protocol would improve synchrony of estrus without compromising fertility in yearling beef heifers. Heifers at two locations (Location 1, n = 60 and Location 2, n = 64) were assigned randomly to one of two treatments by breed and pubertal status. Heifers were defined as, pubertal when concentrations of progesterone in serum were elevated (> or = 1 ng/mL) in either one of two samples obtained 10 and 1 day prior to treatment initiation. Prior to MGA administration, 18/60 (30%) and 36/64 (56%) of the heifers at Locations 1 and 2, respectively, were pubertal. Heifers in both treatments were fed MGA (0.5 mg/head/day in 1.8 kg/head/day supplement) for 14 days followed by 25 mg of PGF2alpha i.m. (MGA-PGF2alpha) 19 days after MGA withdrawal (Day 33 of treatment). One-half of the heifers at each location received 100 microg of GnRH i.m. 12 days after MGA withdrawal (Day 26 of treatment; MGA Select). The control group received only MGA-PGF2alpha. Heifers were observed for signs of behavioral estrus continuously during daylight hours for 7 days beginning on the day PGF2alpha was administered. Heifers were inseminated 12 h after observed estrus. There was a treatment by location by pubertal status interaction (P < 0.05) for interval to estrus. Compared to the respective control treatment at each location, prepubertal heifers assigned to the MGA Select protocol at Location 1 had longer intervals to estrus, whereas at Location 2, prepubertal heifers assigned to the MGA-PGF2alpha protocol had longer intervals to estrus. The higher number of pubertal heifers at Location 2 was associated with a reduced variance in the interval to estrus among MGA

  9. Estrus synchronization in microminipig using estradiol dipropionate and prostaglandin F2α

    PubMed Central

    NOGUCHI, Michiko; IKEDO, Tomonobu; KAWAGUCHI, Hiroaki; TANIMOTO, Akihide

    2016-01-01

    The induction of pseudopregnancy by the exogenous administration of estradiol dipropionate (EDP) was investigated in cyclic Microminipigs (MMpigs) and the effects of exogenous administration of prostaglandin (PG) F2α on estrus exhibition were assessed in pseudopregnant MMpigs. In experiment 1, ovariectomized MMpigs were given a single intramuscular injection of 0.5, 1.5, or 2.5 mg of EDP. The estradiol-17β level at each of these doses was significantly higher 1 to 3 days after EDP administration than on the day of the injection. In experiment 2, animals were given 1.5 mg of EDP once at 9 to 12 days after the end of estrus (D0) and then no (1.5 mg × 1 group), one (D0 and D4; 1.5 mg × 2 group), or two (D0, D4 and D7; 1.5 mg × 3 group) additional treatments. The pseudopregnancy rate was significantly higher in the 1.5 mg × 3 than in the 1.5 mg × 1 group. In experiment 3, PGF2α was administered twice between 26 and 28 days after EDP treatment to five pseudopregnant gilts with a 24-h interval between the two injections. Estrus after PGF2α treatment and LH surge were observed in 100% and 80% pseudopregnant MMpigs, respectively. The interval from the day of the first PGF2α treatment to the onset of estrus was 6.5 ± 0.2 days. These results indicate that multiple EDP treatments are required for induction of pseudopregnancy in MMpigs and estrus exhibition can be controlled in MMpigs by treatment with EDP and PGF2α. PMID:27151362

  10. Estrus synchronization in microminipig using estradiol dipropionate and prostaglandin F2α.

    PubMed

    Noguchi, Michiko; Ikedo, Tomonobu; Kawaguchi, Hiroaki; Tanimoto, Akihide

    2016-08-25

    The induction of pseudopregnancy by the exogenous administration of estradiol dipropionate (EDP) was investigated in cyclic Microminipigs (MMpigs) and the effects of exogenous administration of prostaglandin (PG) F2α on estrus exhibition were assessed in pseudopregnant MMpigs. In experiment 1, ovariectomized MMpigs were given a single intramuscular injection of 0.5, 1.5, or 2.5 mg of EDP. The estradiol-17β level at each of these doses was significantly higher 1 to 3 days after EDP administration than on the day of the injection. In experiment 2, animals were given 1.5 mg of EDP once at 9 to 12 days after the end of estrus (D0) and then no (1.5 mg × 1 group), one (D0 and D4; 1.5 mg × 2 group), or two (D0, D4 and D7; 1.5 mg × 3 group) additional treatments. The pseudopregnancy rate was significantly higher in the 1.5 mg × 3 than in the 1.5 mg × 1 group. In experiment 3, PGF2α was administered twice between 26 and 28 days after EDP treatment to five pseudopregnant gilts with a 24-h interval between the two injections. Estrus after PGF2α treatment and LH surge were observed in 100% and 80% pseudopregnant MMpigs, respectively. The interval from the day of the first PGF2α treatment to the onset of estrus was 6.5 ± 0.2 days. These results indicate that multiple EDP treatments are required for induction of pseudopregnancy in MMpigs and estrus exhibition can be controlled in MMpigs by treatment with EDP and PGF2α.

  11. Estrus synchronization in microminipig using estradiol dipropionate and prostaglandin F2α.

    PubMed

    Noguchi, Michiko; Ikedo, Tomonobu; Kawaguchi, Hiroaki; Tanimoto, Akihide

    2016-08-25

    The induction of pseudopregnancy by the exogenous administration of estradiol dipropionate (EDP) was investigated in cyclic Microminipigs (MMpigs) and the effects of exogenous administration of prostaglandin (PG) F2α on estrus exhibition were assessed in pseudopregnant MMpigs. In experiment 1, ovariectomized MMpigs were given a single intramuscular injection of 0.5, 1.5, or 2.5 mg of EDP. The estradiol-17β level at each of these doses was significantly higher 1 to 3 days after EDP administration than on the day of the injection. In experiment 2, animals were given 1.5 mg of EDP once at 9 to 12 days after the end of estrus (D0) and then no (1.5 mg × 1 group), one (D0 and D4; 1.5 mg × 2 group), or two (D0, D4 and D7; 1.5 mg × 3 group) additional treatments. The pseudopregnancy rate was significantly higher in the 1.5 mg × 3 than in the 1.5 mg × 1 group. In experiment 3, PGF2α was administered twice between 26 and 28 days after EDP treatment to five pseudopregnant gilts with a 24-h interval between the two injections. Estrus after PGF2α treatment and LH surge were observed in 100% and 80% pseudopregnant MMpigs, respectively. The interval from the day of the first PGF2α treatment to the onset of estrus was 6.5 ± 0.2 days. These results indicate that multiple EDP treatments are required for induction of pseudopregnancy in MMpigs and estrus exhibition can be controlled in MMpigs by treatment with EDP and PGF2α. PMID:27151362

  12. Reproductive hormone profiles in sows on estrus synchronization using estradiol dipropionate and prostaglandin F(2α)-analogue and the reproductive performance in female pigs on commercial farms.

    PubMed

    Noguchi, Michiko; Kashiwai, Shinsuke; Itoh, Seigo; Okumura, Hanako; Kure, Katsumasa; Suzuki, Chie; Yoshioka, Koji

    2013-01-01

    Changes in ovarian structures and hormonal profiles in estradiol dipropionate (EDP)-induced pseudopregnant sows following PGF2α-analogue (PGF2α-A) administration and practicality of the estrus synchronization protocol using EDP and PGF2α-A on estrus expression and reproductive performance in commercial conditions were investigated. Pseudopregnancy was defined as absence of estrus maintained for at least 20 days after EDP treatment in this study. When 4 pseudopregnant sows induced by 20 mg EDP were treated with PGF2α-A as 0.175 mg cloprostenol twice at a 24-hr interval between 20 and 28 days after EDP treatment, plasma progesterone concentrations rapidly decreased after treatment. The luteinizing hormone surge and ovulation were detected in all sows. The number of ovulated follicles was 17.3 ± 1.1 (SEM). On commercial farms, 94.2% of 52 gilts and 95.2% of 21 sows received EDP became pseudopregnant. When these pseudopregnant females (48 gilts and 20 sows) were treated with PGF2α-A as described above, estrus was detected in all females at 6.1 ± 0.3 days for gilts and 5.5 ± 0.2 days for sows after the first PGF2α-A treatment. There were no significant differences in farrowing rate (85.0 - 100%), average total litter size (10.0 - 11.4), average born alive litter size (9.4 - 10.3) and average piglet birth weight (1.56 - 1.71 kg) between PGF2α-A treated pseudopregnant female pigs that were inseminated during synchronized estrus and females inseminated during spontaneous estrus. This study indicates that estrus synchronization programs using EDP and PGF2α-A are available as practical and convenient procedures for commercial pig farms.

  13. Physiology and Endocrinology Symposium: Harnessing basic knowledge of factors controlling puberty to improve synchronization of estrus and fertility in heifers.

    PubMed

    Perry, G A

    2012-04-01

    The development of replacement heifers is a major economic investment for all beef and dairy operations. The costs associated with heifer development cannot be recovered if heifers do not conceive and remain productive in the herd; therefore, heifers need to conceive early in the breeding season or risk being culled. Previous research has reported up to a 21% increase in fertility from pubertal estrus to the third estrus of a heifer. The use of reproductive tract scores to determine pubertal status has demonstrated that peripubertal and pubertal heifers have increased pregnancy success to estrous synchronization compared with heifers that were prepubertal. The development of RIA has allowed accurate measurement of peripheral blood hormone concentrations associated with the pubertal process and luteal formation. This basic knowledge has increased our understanding of the mechanisms that control puberty in heifers. In addition, understanding the hormonal changes that occur during the estrous cycle has allowed for the development of estrous synchronization protocols that result in increased control of follicular growth, regression of luteal tissue, and ovulation. Transrectal ultrasonography has increased our understanding of follicular waves; this understanding led to research investigating the endocrine regulation of follicular waves and development of methods to synchronize follicular waves for purposes of fixed-time AI. Current topics of research include the effect of antral follicle count on fertility and the effect of maternal nutrition (on the fetus in utero) on subsequent reproductive potential of a heifer (i.e., fetal programming). Advancements in genomic technologies will likely provide a powerful tool for selecting heifers at birth that will have a greater probability of being reproductively successful if managed correctly. Therefore, knowledge gained through basic research on factors that control puberty has improved and will continue to improve heifer

  14. Comparison of two timed artificial insemination system schemes to synchronize estrus and ovulation in Nellore cattle.

    PubMed

    Ferraz Junior, Marcos V C; Pires, Alexandre V; Biehl, Marcos V; Santos, Marcelo H; Barroso, José P R; Gonçalves, José R S; Sartori, Roberto; Day, Michael L

    2016-11-01

    The aim of this study was to evaluate the reproductive performance of 411 Nellore cows (198 nulliparous, 80 primiparous, and 133 multiparous) submitted to the 5dCO-Synch + P4 or 7dEB + P4 systems. The 5dCO-Synch + P4 system consisted of insertion of an intravaginal progesterone (P4) insert and 100 μg of GnRH (intramuscularly [i.m.]) on Day 0. On Day 5, the P4 insert was removed, and two doses of 25 mg of PGF2α (i.m.) were administered 6 hours apart. Cows not detected in estrus until 55 hours after insert removal received 100 μg of GnRH i.m. 17 hours later (i.e., 72 hours after P4 removal). The 7dEB + P4 system consisted of insertion of a P4 insert and 2 mg of estradiol benzoate (i.m.) on Day 0. On Day 7, the P4 insert was removed and 25 mg of PGF2α, 0.6 mg of estradiol cypionate, and 300 IU of eCG were administered i.m. In both systems, artificial insemination (AI) was performed according to estrus detection (i.e., cows detected in estrus until 55 hours after insert removal were inseminated at 55 hours and cows detected in estrus later or those not detected in estrus were inseminated at 72 hours). Estrus-detection risk was greater (P < 0.05) in 7dEB + P4 (80.4%) than 5dCO-Synch + P4 system (36.4%). Progesterone concentration 10 days after AI was greater (P < 0.05) in 7dEB + P4 than 5dCO-Synch + P4 system in primiparous and multiparous but did not differ between systems in nulliparous cows. Pregnancy per AI was greater (P < 0.05) in 7dEB + P4 (49.7%) than 5dCO-Synch + P4 (35.4%) system. Primiparous had lower estrus-detection risk (25.0%), ovulation risk (76.6%), and pregnancy per AI (28.7%) than multiparous or nulliparous cows. In conclusion, reproductive performance was reduced with the 5dCO-Synch + P4 in comparison with the 7dEB + P4 system in Nellore cows. Moreover, the reproductive traits observed for primiparous cows indicate that more attention is required when timed AI programs are started early after calving.

  15. Short communication: Drug residues in goat milk after prophylactic use of antibiotics in intravaginal sponges for estrus synchronization.

    PubMed

    Romero, T; Balado, J; Althaus, R L; Beltrán, M C; Molina, M P

    2016-01-01

    The aim of this study was to determine whether the prophylactic use of antibiotics in intravaginal sponges used for estrus synchronization in goats may result in the presence of inhibitors in milk and, therefore, of positive results by microbial screening tests. Ninety-eight Murciano-Granadina goats were used, divided into 7 groups of 14 animals. Intravaginal sponges were placed in 6 groups using 2 concentrations of 3 different antibiotics: doxycycline, oxytetracycline, and sulfathiazole-framycetin. The sponges of the control group were placed without antibiotics. Milk samples were collected daily until 7 d posttreatment and analyzed using 3 microbial tests. Positive samples were retested by specific receptor-binding assays to confirm the positive results. Vaginal status was evaluated by visual assessment of the external aspect of the sponges after removal. The microbial test response was not affected by either day posttreatment or dose of antibiotic used, except for oxytetracycline at the higher concentration. Moreover, no positive results were obtained using receptor-binding assays, suggesting that residues, if present in milk, did not exceed the regulatory (safety) levels established for these drugs. The occurrence of soiled sponges was higher in the control group. With respect to the dose of antibiotics used, no significant differences were found for the lower dose administered. However, a significant increase in the percentage of clean sponges was observed for the higher dose of doxycycline. We conclude that the prophylactic use of low doses of doxycycline, oxytetracycline, or sulfathiazole in intravaginal sponges used for synchronization of estrus helps to reduce clinical vaginitis in dairy goats and does not seem to be the cause of positive results in microbial inhibitor tests used to detect antibiotics in goat milk. PMID:26585470

  16. Short communication: Drug residues in goat milk after prophylactic use of antibiotics in intravaginal sponges for estrus synchronization.

    PubMed

    Romero, T; Balado, J; Althaus, R L; Beltrán, M C; Molina, M P

    2016-01-01

    The aim of this study was to determine whether the prophylactic use of antibiotics in intravaginal sponges used for estrus synchronization in goats may result in the presence of inhibitors in milk and, therefore, of positive results by microbial screening tests. Ninety-eight Murciano-Granadina goats were used, divided into 7 groups of 14 animals. Intravaginal sponges were placed in 6 groups using 2 concentrations of 3 different antibiotics: doxycycline, oxytetracycline, and sulfathiazole-framycetin. The sponges of the control group were placed without antibiotics. Milk samples were collected daily until 7 d posttreatment and analyzed using 3 microbial tests. Positive samples were retested by specific receptor-binding assays to confirm the positive results. Vaginal status was evaluated by visual assessment of the external aspect of the sponges after removal. The microbial test response was not affected by either day posttreatment or dose of antibiotic used, except for oxytetracycline at the higher concentration. Moreover, no positive results were obtained using receptor-binding assays, suggesting that residues, if present in milk, did not exceed the regulatory (safety) levels established for these drugs. The occurrence of soiled sponges was higher in the control group. With respect to the dose of antibiotics used, no significant differences were found for the lower dose administered. However, a significant increase in the percentage of clean sponges was observed for the higher dose of doxycycline. We conclude that the prophylactic use of low doses of doxycycline, oxytetracycline, or sulfathiazole in intravaginal sponges used for synchronization of estrus helps to reduce clinical vaginitis in dairy goats and does not seem to be the cause of positive results in microbial inhibitor tests used to detect antibiotics in goat milk.

  17. Synchronization of estrus and artificial insemination in replacement beef heifers using gonadotropin-releasing hormone, prostaglandin F2alpha, and progesterone.

    PubMed

    Lamb, G C; Larson, J E; Geary, T W; Stevenson, J S; Johnson, S K; Day, M L; Ansotegui, R P; Kesler, D J; DeJarnette, J M; Landblom, D G

    2006-11-01

    We evaluated whether a fixed-time AI (TAI) protocol could yield pregnancy rates similar to a protocol requiring detection of estrus, or detection of estrus and AI plus a clean-up TAI for heifers not detected in estrus, and whether adding an injection of GnRH at controlled internal drug release (CIDR) insertion would enhance fertility in CIDR-based protocols. Estrus in 2,075 replacement beef heifers at 12 locations was synchronized, and AI was preceded by 1 of 4 treatments arranged as a 2 x 2 factorial design: 1) Estrus detection + TAI (ETAI) (n = 516): CIDR for 7 d plus 25 mg of prostaglandin F2alpha (PG) at CIDR insert removal, followed by detection of estrus for 72 h and AI for 84 h after PG (heifers not detected in estrus by 84 h received 100 microg of GnRH and TAI); 2) G+ETAI (n = 503): ETAI plus 100 microg GnRH at CIDR insertion; 3) Fixed-time AI (FTAI) (n = 525): CIDR for 7 d plus 25 mg of PG at CIDR removal, followed in 60 h by a second injection of GnRH and TAI; 4) G+FTAI (n = 531): FTAI plus 100 microg of GnRH at CIDR insertion. Blood samples were collected (d -17 and -7, relative to PG) to determine ovarian status. For heifers in ETAI and G+ETAI treatments, a minimum of twice daily observations for estrus began on d 0 and continued for at least 72 h. Inseminations were performed according to the a.m.-p.m. rule. Pregnancy was diagnosed by transrectal ultrasonography. The percentage of heifers exhibiting ovarian cyclic activity at the initiation of treatments was 89%. Pregnancy rates among locations across treatments ranged from 38 to 74%. Pregnancy rates were 54.7, 57.5, 49.3, and 53.1% for ETAI, G+ETAI, FTAI, and G+FTAI treatments, respectively. Although pregnancy rates were similar among treatments, a tendency (P = 0.065) occurred for pregnancy rates in the G+ETAI treatment to be greater than in the FTAI treatment. We concluded that the G+FTAI protocol yielded pregnancy rates similar to protocols that combine estrus detection and TAI. Further, the G

  18. Synchronization of estrus and ovulation in sows not conceiving in a scheduled fixed-time insemination program.

    PubMed

    Kauffold, Johannes; Beckjunker, Jochen; Kanora, Alain; Zaremba, Wolfgang

    2007-01-01

    A field study was conducted to investigate the effectiveness of a treatment with altrenogest, eCG and hCG or the GnRH-analogue D-Phe(6)-LHRH to synchronize estrus and ovulation of sows diagnosed as non-pregnant in order to reintegrate them back into a scheduled fixed-time insemination program. Sows (n=531) diagnosed as non-pregnant by ultrasonography on days 21-35 after insemination were subjected to one of three treatments: (1) 16 mg altrenogest/day/animal orally for 15 days to block follicular growth, followed by injection of 1000 IU eCG intramuscularly (i.m.) 24h after withdrawal of altrenogest to stimulate follicular growth and 500 IU hCG i.m. 78-80 h after eCG to induce ovulation; (2) similar to (1) except that 20mg altrenogest and 800 IU eCG were used and (3) similar to (2) except that 50 microg D-Phe(6)-LHRH was used to induce ovulation. Females were artificially inseminated (AI) twice at 24 and 40 h, respectively, after hCG/D-Phe(6)-LHRH. Success of treatments was checked by ultrasonography of the ovaries. Rates of conception and farrowing (CR, FR), and number of total and live born piglets (TB, LB) were recorded and compared to those of synchronized first served sows. Females had differing ovarian structures prior to treatment. Altrenogest effectively blocked follicular growth in >80% of the females irrespective of dosage, but 16 mg increased the development of polycystic ovarian degeneration. Four to 18% of the females still had corpora lutea after altrenogest. Most females ovulated either between both inseminations or thereafter (P<0.05). Females treated with D-Phe(6)-LHRH tended to ovulate earlier than those injected with hCG. The CR and FR were up to 25% lower for sows diagnosed as non-pregnant than for sows after first service (P<0.05). Among sows diagnosed as non-pregnant the CR was higher in females treated with D-Phe(6)-LHRH (P<0.05). No differences were found in regard to numbers of TB and LB. In conclusion, a treatment with 20mg altrenogest per

  19. Synchronization of ovarian follicular waves with a gonadotropin-releasing hormone agonist to increase the precision of estrus in cattle: a review.

    PubMed

    Twagiramungu, H; Guilbault, L A; Dufour, J J

    1995-10-01

    Treatment with GnRH and PGF2 alpha is a practical method for controlling ovarian follicular and luteal functions and increasing the precision of estrus synchronization in cyclic and acyclic postpartum cows and heifers. This method reduces considerably the period of time needed for estrus detection; it synchronizes the estrous cycle of 70 to 80% of the cyclic cows to within a 4-d interval without any detrimental effect on the fertility rate (65 to 85%). Moreover, resumption of ovarian activity and normal fertility in acyclic cows in favored. Administration of GnRH eliminates the large follicles by ovulation or atresia and induces emergence of a new follicular wave within 3 to 4 d after treatment at any stage of the estrous cycle, but it limits further growth of these emerging follicles by increasing atresia. The precision of estrus and the unaltered fertility rate is due to the synchronized selection of a new larger growing follicle, which becomes the ovulatory follicle after PGF(2 alpha)-induced luteolysis 6 d after GnRH treatment. Also, fixed-time AI programs without the need for estrus detection may be possible using a second injection of GnRH in a GnRH-PGF(2 alpha)-GnRH protocol to ovulate the selected follicle at a precise time. We describe a physiological model to explain how the precision of estrus is improved following PGF(2 alpha)-induced luteolysis, via the effect of pretreatment with GnRH on follicular development and luteal functions in cattle. Application of this model to the development of reliable methods of fixed-time insemination is also explored. PMID:8617687

  20. Photoperiod length and the estrus synchronization protocol used before AI affect the twin pregnancy rate in dairy cattle.

    PubMed

    Andreu-Vázquez, C; Garcia-Ispierto, I; López-Gatius, F

    2012-10-01

    This study addresses potential management risk factors affecting the incidence of twin pregnancies in high-producing dairy cows. Special attention was paid to the estrus synchronization protocol used before the AI resulting in pregnancy. Possible factors affecting the twin pregnancy rate were analyzed through binary logistic regression procedures on 2015 pregnant cows from July 2010 to July 2011. Twin pregnancy was recorded in 361 of the 2015 pregnancy diagnoses made (17.9%). Twin pregnancy rates differed among herds (P < 0.001) and ranged from 12.4% to 23.9%. Based on the odds ratios, the risk of twin pregnancy was reduced by factors of 0.65 or 0.71 when AI was performed during the warm season or an increasing photoperiod, respectively and increased by a factor of 1.11 for each unit increase in lactation number; by factors of 4.57 or 6.33 in cows that received a progesterone-releasing intravaginal device (PRID) plus 500 or 750 IU of equine chorionic gonadotropin (eCG) 28 days before the pregnancy AI, respectively; by a factor of 2.39 in cows with an ovarian cyst diagnosed in the 14 days prior to AI and treated with prostaglandins (PG); by factors of 1.94 or 3.91 in cows that received two PG doses during the 14 days prior to AI or cows that following failed PRID treatment had received PG started over the 28 days prior to AI, respectively; and by a factor of 2.58 in cows that had previously delivered twins compared to cows delivering singletons. Our results indicate that cow factors, such as lactation number and previous twining, as well as environmental factors, such as photoperiod and season and management related to synchronization protocols affect significantly the incidence of twin pregnancies.

  1. The 9-day CIDR-PG protocol: Incorporation of PGF2α pretreatment into a long-term progestin-based estrus synchronization protocol for postpartum beef cows.

    PubMed

    Thomas, Jordan M; Bishop, Brianne E; Abel, Jillian M; Ellersieck, Mark R; Smith, Michael F; Patterson, David J

    2016-06-01

    A pilot experiment was designed to test the hypothesis that administration of PGF2α before progestin treatment would allow for a reduced duration of progestin treatment in a long-term progestin-based estrus synchronization protocol. A modified presynchronization treatment was compared with a standard long-term controlled internal drug release (CIDR) treatment, and treatments were compared on the basis of ovarian follicular dynamics, estrous response rate, synchrony of estrus expression, and pregnancy rates resulting from timed artificial insemination (TAI) in postpartum beef cows. Estrous was synchronized for 85 cows, with cows assigned to one of two treatments based on age, days postpartum, and body condition score. Cows assigned to the 14-day CIDR-PG protocol received a CIDR insert (1.38 g progesterone) on Day 0, CIDR removal on Day 14, and administration of PGF2α (25 mg im) on Day 30. Cows assigned to the 9-day CIDR-PG protocol received PGF2α concurrent with CIDR insertion on Day 5, PGF2α concurrent with CIDR removal on Day 14, and administration of PGF2α on Day 30. In both treatments, split-time AI was performed based on estrous response. At 72 hours after PGF2α (Day 33), cows having expressed estrus received TAI; cows that failed to express estrus by 72 hours received TAI 24 hours later (96 hours after PGF2α on Day 34), with GnRH (100 μg im) administered to nonestrous cows. Estrus-detection transmitters were used from CIDR removal until AI to determine onset time of estrus expression both after CIDR removal and after PGF2α. Ovarian ultrasonography was performed at CIDR removal on Day 14, PGF2α on Day 30, and AI on Days 33 or 34. At CIDR removal on Day 14, diameter of the largest follicle present on the ovary was similar between treatments. The proportion of cows expressing estrus after CIDR removal tended to be higher (P = 0.09) among cows assigned to the 9-day CIDR-PG treatment (93%; 40 of 43) than among cows assigned to the 14-day CIDR

  2. [Insertion and removal of intravaginal tampons during estrus synchronization in heifers].

    PubMed

    Zaoral, J; Hlavová, V; Janda, A

    1978-12-01

    In eight trials, 197 heifers were synchronized with gestagen chlorsuperlutin (CSL). The intravaginal tampons soaked with chlorsuperlutin were introduced in the vagina by means of an applier by a vaginal speculum. Silon threads were attached to the tampons, by which they were pulled out after treatment. The mentioned method of application removes the great physical exertion needed for manual application and increases labour productivity in tampon application by about 200%. The hazard of tampon contamination is reduced to the minimum. Of the two tampon types tested (ester and ether type) the ester type was found to be better for not needing sterilization if the disinfectant Aseptin is dropped upon it prior to application. The retention of the tampons was 94.9%. Eighty-four per cent of the retained tampons could be removed by pulling the silon threads. About 40 to 60% of CSL is excreted from the tampons during the treatment. If the initial content of CSL is increased, its excretion is raised as well.

  3. Use of fluorogestone acetate sponges or controlled internal drug release for estrus synchronization in ewes: Effects of hormonal profiles and reproductive performance.

    PubMed

    Swelum, Ayman Abdel-Aziz; Alowaimer, Abdullah Nasser; Abouheif, Mohamed Ahmed

    2015-09-01

    This study was carried out using 300 multiparous Najdi ewes during breeding season to compare the effects of fluorogestone acetate (FGA) sponges and controlled internal drug release (CIDR) dispensers to synchronize estrus on reproductive performance and hormonal profiles. Ewes were equally and randomly allotted into group A (FGA) and group B (CIDR); intravaginal progestagen was administered for 14-day period with intramuscular administration of 600-IU eCG at withdrawal time. Estrus was detected using a vasectomized ram starting 12 hours after progestagen withdrawal and repeated every 12 hours up to 84 hours. Blood samples were collected at the time of progestagen withdrawal (0 hour), 24 hours, and 48 hours. Follicle-stimulating hormone, LH, estradiol, and progesterone serum concentrations were measured using commercial ELISA kits and microtitrimetric plates. Timed laparoscopic insemination was performed 48 hours after progestagen withdrawal. Pregnancy and the number of fetuses were diagnosed by ultrasonography on Day 23 after insemination and confirmed on Days 35 and 60. The results revealed that the retention, vaginal discharge, and drawstring breakage rates after progestagen removal were significantly (P ≤ 0.05) higher in the FGA group (94.00, 98.58, and 9.22, respectively) than those in the CIDR group. On the other hand, pregnancy, fertility, twinning rates, and fecundity were significantly (P ≤ 0.05) higher in the CIDR group (77.86, 75.57, 34.34, and 1.02, respectively) than in the FGA group. Estrus responses in FGA and CIDR groups increased gradually to attain their significantly (P ≤ 0.05) higher percentages after 48 hours of progestagen withdrawal (91.49 and 92.37, respectively); thereafter, they decreased. The overall estrus responses and prolificacy did not differ between the FGA and CIDR groups. Follicle-stimulating hormone was significantly higher in the FGA group at 24 and 48 hours after progestagen withdrawal, whereas LH was significantly higher

  4. The effect of estrus synchronization treatment on somatic cell count of transitional-anestrus local-Damascus cross breed goats' milk.

    PubMed

    Talafha, A Q; Lafi, S Q; Ababneh, M M

    2008-04-01

    An experiment was conducted to examine the effect of estrus synchronization protocols and steroid hormones concentrations on somatic cell count (SCC) of transitional-anestrus local-Damascus cross goats' milk. Fifty-six goats (2-4-year old) were randomly assigned to three groups: fluorogestone acetate (FGA, n = 19), FGA-Prostaglandin (FGA-PGF, n = 19) and control (n = 18) groups. Intravaginal sponge containing 40 mg FGA was inserted for 13 days and an injection of 600 IU equine chorionic gonadotropin (eCG) was administered for goats of FGA and FGA-PGF groups at the time of sponge removal (day 0). In addition, goats of FGA-PGF group were injected with 10 mg dinoprost tromethamine (PGF2alpha) on day 0. Five fertile local-Damascus cross bucks were turned-in with all goats on day 0. Blood and milk samples were collected from all goats on days -13 (beginning of experiment), -6, 0, 1, 2, 7, 13 and 20 (end of the experiment). Four-year old and second-parity goats had significantly higher (p < 0.05) SCC of both udder halves than 2- and 3-year old and first-parity goats, respectively. There was a significant effect (p < 0.05) for treatment and number of kids born in the last kidding season on SCC of both udder halves. Neither estradiol nor progesterone concentrations were correlated with SCC in goats in this experiment. The SCC of both udder halves and left udder halves in goats of the control and FGA groups, respectively, increased significantly (p < 0.05) after sponge removal and buck introduction when compared with day 0, with no differences in the FGA-PGF group. This increase in SCC of the control and FGA groups coincided with peak estrus behavior. However, SCC was far below the upper limit of the current standard for normal milk. In conclusion, induction of estrus with progestagen based programs and buck introduction may cause temporary significant increase in SCC. However, the SCC values during this period of temporary increase were still in the range of acceptable

  5. Conception rates to artificial insemination in primiparous, suckled cows exposed to the biostimulatory effect of bulls before and during a gonadotropin-releasing hormone-based estrus synchronization protocol.

    PubMed

    Berardinelli, J G; Joshi, P S; Tauck, S A

    2007-03-01

    The objective of these studies was to evaluate whether exposing primiparous, suckled beef cows to the biostimulatory effect of bulls alters breeding performance associated with an estrus synchronization protocol that included GnRH followed 7 d later by PGF(2alpha) and fixed-time AI (TAI). This was a composite analysis of 3 experiments that evaluated (1) the effects of bull exposure at different days after calving (yr 1); (2) the biostimulatory effects of bull excretory products (yr 2); and (3) the biostimulatory effects of familiar and unfamiliar bulls (yr 3) on the resumption of ovarian cycling activity. In all studies, cows were exposed (biostimulated; n = 94) or not exposed (nonbiostimulated; n = 67) to bulls or excretory products of bulls for at least 60 d before the beginning of the estrus synchronization protocol. Average calving day did not differ among years and was 52 +/- 5 d. Year did not affect the proportions of biostimulated and nonbiostimulated cows that were cycling at the beginning of the estrus synchronization protocol; however, a greater (P < 0.001) proportion of biostimulated than nonbiostimulated cows were cycling at this time. In each year, cows were given GnRH followed by PGF(2alpha) 7 d later. Cows were observed for estrus twice daily (am and pm) after PGF(2alpha). Cows that exhibited estrus before 54, 60, and 64 h after PGF(2alpha) were inseminated by AI 12 h later in yr 1, 2, and 3, respectively. Cows that failed to show estrus were given GnRH and TAI at 62, 72, and 72 h after PGF(2alpha) in yr 1, 2, and 3, respectively. Conception rates were determined by transrectal ultrasonography 35 d after TAI in each year. The percentages of cows that exhibited estrus after PGF(2alpha) and before TAI, the interval from PGF(2alpha) to estrus, and the percentages of cows inseminated 12 h after estrus or at TAI did not differ between biostimulated and nonbiostimulated cows and were 51%, 54.7 +/- 7.3 h, 35%, and 65%, respectively. Conception rates for

  6. Progesterone status, parity, body condition, and days postpartum before estrus or ovulation synchronization in suckled beef cattle influence artificial insemination pregnancy outcomes.

    PubMed

    Stevenson, J S; Hill, S L; Bridges, G A; Larson, J E; Lamb, G C

    2015-05-01

    Our objective was to assess the effects of progesterone before initiating an estrus- or ovulation-synchronization program in addition to the influence of parity, BCS, and days postpartum on resulting pregnancy rates per AI. Experimental data were combined from 73 herd-year studies consisting of more than 8,500 suckled beef cows exposed to variants of the CO-Synch program. Blood was harvested from samples collected at 10 and 0 d before the onset of CO-Synch, and progesterone concentrations of the samples were determined. The progesterone environment preceding synchronization was assessed in 3 ways on the basis of progesterone concentrations measured in the 2 defined blood samples. All binomial logistic regression models used procedure GLIMMIX in SAS and included the fixed effects of program duration, inclusion of progesterone via an intravaginal insert, parity, days postpartum at AI, BCS, and appropriate interactions. In addition, model 1 included 3 categories of progesterone concentrations (low [<1 ng/mL], medium [1.00 to 3.99 ng/mL], and high [≥4.00 ng/mL] concentrations) at 10 and 0 d before synchronization and their interaction. Model 2 included 4 categories defining the stage of the estrous cycle (late diestrus, early diestrus, and proestrus-estrus-metestrus) or anestrus, at which cows started the synchronization program. Model 3 defined cows as cycling or noncycling at the onset of the program. Significant effects of progesterone supplementation, which hormone was used to initiate the timed AI program, parity, BCS, days postpartum, and progesterone status assessed in 3 ways were consistent in nearly all models. Progesterone status at the onset of synchronization was not important to pregnancy outcomes in multiparous cows, whereas pregnancy rate per AI was suppressed in primiparous cows that began in a low-progesterone environment (proestrus, estrus, metestrus, or anestrus). A significant 3-way interaction of parity, BCS, and days postpartum in 2 models

  7. Effects of physiological and/or disease status on the response of postpartum dairy cows to synchronization of estrus using an intravaginal progesterone device.

    PubMed

    McNally, Julie C; Crowe, Mark A; Roche, James F; Beltman, Marijke E

    2014-12-01

    Progesterone treatments are used to increase submission rates in postpartum dairy cows; however, in many cases the protocol is used as a blanket therapy for all cows without regard for physiological or disease state. The objective of this study was to identify the physiological or disease classes of cows that respond well (or not) to synchronization of estrus via progesterone. Dairy cows (n = 402) were monitored peri and postpartum to establish their physiological or disease status. Animals were classified as having negative energy balance, clinical lameness, uterine infection (UI), anovulatory anestrus, high somatic cell counts, and healthy (H). Blood samples were collected at five different time points and analyzed for metabolites. All animals received an 8-day controlled internal drug release protocol, which included GnRH at insertion and PGF2α the day before removal. Response to the protocol was determined by visual observation of estrus synchronization. Conception rate was determined by ultrasonography between Days 32 and 35 after artificial insemination. Animals without UI were 1.9 times more likely to respond and two times more likely to be confirmed pregnant than those with UI. There was no relationship between negative energy balance and clinical lameness in the visual estrous response, but both conditions were associated with reduced conception rates. Dairy cows in anovulatory anestrus responded successfully to the protocol in both estrous response and conception rates. High glutathione peroxidase concentrations had a positive effect on conception rates, whereas high non-esterified fatty acids and beta-hydroxybutyrate had a negative effect on the estrous response. In conclusion, disease and physiological states of dairy cows determined the response to progesterone-based synchronization. The more disease or physiological problems the cows had, the lower the estrous response and conception rates; cows with these problems were not ideal candidates for

  8. Differences in uterine immunoexpression of PR, ERα and OTR when comparing prostaglandin- to progestagen-based protocols for ovine estrus synchronization.

    PubMed

    Ruiz-González, I; Sánchez, M A; García-Palencia, P; Sánchez, B; García-Fernández, R A; González-Bulnes, A; Flores, J M

    2012-07-01

    The aim of this work was to compare PR, ERα and OTR uterine expression between days 9 and 21 of pregnancy in ewes whose estrus had been synchronized with two different protocols. Sixty-four adult Manchega ewes were synchronized with either conventional progestagens (P) or prostaglandin analogues (PG), and mated. Uterine samples were obtained from pregnant animals (group P, n=24; group PG, n=25) on days 9 post coitus (pc), 13pc, 15pc, 17pc and 21pc. Immunohistochemical detection of progesterone receptor (PR), estrogen receptor-α (ERα) and oxytocin receptor (OTR) was assessed in different uterine cell compartments including luminal and glandular epithelium, stroma and myometrium. Interaction day × treatment was obtained when assessing PR expression in the caruncular stroma (P=0.027) and myometrium (P=0.000), as well as for ERα in the superficial stroma (P=0.05). Significant "day post coitus" effect was found regarding to PR (P<0.01, with the exception of the superficial stroma, deep stroma and myometrium), ERα (P<0.01), and OTR (P<0.05, except in the deep compartments). No significant "treatment" effect was found for PR, ERα or OTR protein immunoexpression. This study supports the implication of PR, ERα and OTR within days 9-21 of the ovine pregnancy. Moreover, different expression pattern of PR and ERα proteins has been found between treatments in various compartments studied. Collectively, these results indicate that PR, ERα and OTR expression during early pregnancy is similar between ewes treated with either progestagens or prostaglandin analogues-based protocols for estrus synchronization.

  9. Progesterone, follicular, and estrual responses to progesterone-based estrus and ovulation synchronization protocols at five stages of the estrous cycle.

    PubMed

    Stevenson, J S

    2008-12-01

    the most consistent (estrus vs. TAI) pregnancies per AI (65.4%) compared with other cycle days. Compared with controls, more progesterone-treated heifers ovulated by 96 h after insert removal. Application of the progesterone insert reduced variance of the interval to estrus after insert removal (or PGF(2alpha) injection in controls) by 1.6-fold compared with controls. These results do not support the use of GnRH in a progesterone-based synchronization protocol.

  10. Expression of cumulus-oocyte complex genes and embryonic development in goats subjected to progestogen-based estrus synchronization.

    PubMed

    Thammasiri, Jiratti; Navanukraw, Chainarong; Uriyapongson, Suthipong; Khanthusaeng, Vilaivan; Kamollirt, Chuchat

    2016-07-15

    The objective was to investigate the effect of short-term (7 days) and long-term (14 days) progesterone-based estrus synchronization on number of follicles, progesterone concentrations, cumulus-oocyte complex (COC) gene expression, and embryonic development in goats. Nulliparous Thai-native goats (n = 45) were randomly assigned to one of two estrus synchronization treatments. Goats were treated with intravaginal sponges containing 60-mg medroxyprogesterone acetate (MAP; Synchrogest esponjas, Spain) during 7 or 14 days (short-term or long-term protocol, respectively). Multiple follicular development was induced by intramuscularly injections of 300-IU eCG in both groups (1 day before sponge withdrawal). An ovariectomy was performed at 24 hours after sponge removal to evaluate number of follicle and collect oocyte for IVF. Oocyte quality (healthy or nonhealthy) was determined by morphology of COCs before IVM. Recovery of COCs and total cellular RNA isolation were applied to determine apoptosis-related gene expression. After IVF, embryos were evaluated during the eight-day culture as numbers of cleaved oocyte, morula, and blastocyst embryo. Total numbers of follicles and oocytes were similar for both treatments. Plasma progesterone concentrations were not different during MAP insertion period (P > 0.05). However, goats that received the short-term protocol had a greater number of 4 to 6-mm follicle, healthy oocytes, cleaved oocytes, and morula embryos than goats that received the long-term protocol (P < 0.01). In addition, the expression of B-cell lymphoma 2 messenger RNA was greater (P < 0.05) in COCs derived from the 7 days MAP-treated when compared to the 14 days MAP-treated goats. These data highlight that the 7-day progestin-based treatment may contribute to quality of oocytes and embryonic development in goats.

  11. New estrus synchronization and artificial insemination protocol for goats based on male exposure, progesterone and cloprostenol during the non-breeding season.

    PubMed

    López-Sebastian, A; González-Bulnes, A; Carrizosa, J A; Urrutia, B; Díaz-Delfa, C; Santiago-Moreno, J; Gómez-Brunet, A

    2007-11-01

    This study assesses the effectiveness of a method designed to induce and synchronize ovulation in goats during the non-breeding season, allowing for systematic timed artificial insemination (AI), without the need for prior estrus detection. This method (IMA.PRO2) induces ovulation through the "male effect" and a single 25 mg dose of progesterone given at the time of buck exposure, and early lysis of the induced corpus luteum by the administration of 75 microg of cloprostenol 9 days later. The method was tested in three separate experiments. In experiment 1, estrus was detected in 87.5% of the treated goats 37.0 +/- 1.4 h after cloprostenol administration, with the preovulatory LH surge occurring 40.5 +/- 1.6 h after the cloprostenol injection. In experiment 2, data from 503 does revealed no significant differences in fertility rates between two groups inseminated 48 h (65.5+/-4.0%) or 52 h (63+/-3.0%) after receiving cloprostenol. In experiment 3, 2184 does, comprising 37 replicate groups on 12 farms, were randomly assigned to two trial subgroups. Does in the first subgroup were treated with the IMA.PRO2 method and goats from the second group were given intravaginal progestagens for 11 days, plus 350 IU of eCG and 75 microg of cloprostenol on Day 9 of this treatment. Goats from both subgroups were cervically inseminated at the same time, 50 h after cloprostenol administration in the first group and 46 h after sponge removal in the second. The pregnancy rate achieved with the new method was 64.6%, significantly higher than the yield observed for the use of progestagens plus eCG (46.8%, P<0.01). The simple method proposed as an alternative to the use of progestagen-eCG treatment provides good pregnancy rates to AI undertaken at a fixed time point, and reduces the amount of hormone needed to synchronize estrus in the animals. PMID:17889303

  12. ASAS centennial paper: Contributions in the Journal of Animal Science to the development of protocols for breeding management of cattle through synchronization of estrus and ovulation.

    PubMed

    Lauderdale, J W

    2009-02-01

    American Society of Animal Science members, publishing in Journal of Animal Science (JAS), completed research that resulted in understanding the estrous cycle of cattle, which led to the ability to inseminate cattle on a given day with pregnancy rates similar to those achieved by 21-d breeding by a fertile and sound bull. Research published in JAS led to understanding estrus, ovulation, the estrous cycle, and postpartum interval for cattle (1930s through 1960s) and hormonal factors affecting corpus luteum lifespan of cattle (1950s through 1980s). Research during the 1940s to 1960s, using gonadotropins and progesterone to manage the estrous cycle of cattle, established the concepts for estrous synchronization and stimulated commercial research directed at developing cost-effective progestogen estrous synchronization products, leading to commercially available products from 1967 through today (Repromix, melengestrol acetate, Syncro-Mate-B, controlled internal drug release). Prostaglandin F(2alpha) products were approved for estrous synchronization (1970s, 1980s), and GnRH products were approved for use in cattle to treat ovarian follicular cysts (1970s, 1980s). Research published in JAS was essential for understanding the biology of and potential value of both PGF(2alpha) and GnRH and contributed both to new knowledge and scientific bases for future Food and Drug Administration Center for Veterinary Medicine approval of those products. Research during the1980s through 2000s led to understanding ovarian follicular waves and described the timing of follicular recruitment, selection, dominance, and atresia; this research was essential for the ability to effectively manage follicles to achieve success with timed AI. The knowledge gained through research published in JAS resulted in development of the numerous estrous synchronization and breeding management protocols that are cost-effective and meet the breeding management needs of most beef and dairy enterprises.

  13. Fertility in Angus cross beef cows following 5-day CO-Synch + CIDR or 7-day CO-Synch + CIDR estrus synchronization and timed artificial insemination.

    PubMed

    Whittier, William D; Currin, John F; Schramm, Holly; Holland, Sarah; Kasimanickam, Ramanathan K

    2013-12-01

    The present study determined whether a 5-day CO-Synch + controlled internal drug release (CIDR) protocol with two doses of PGF2α would improve timed artificial insemination (AI) pregnancy rate compared with 7-day CO-Synch + CIDR protocol in beef cows. Angus cross beef cows (N = 1817) at 12 locations were randomly assigned to 5-day CO-Synch + CIDR or 7-day CO-Synch + CIDR groups. All cows received 100 μg of GnRH and a CIDR insert on Day 0. Cows (n = 911) in the 5-day CO-Synch + CIDR group received two doses of 25 mg PGF, the first dose given on Day 5 at CIDR removal and the second dose 6 hours later, and 100 μg GnRH on Day 8 and were inseminated concurrently, 72 hours after CIDR removal. Cows (n = 906) in 7-day CO-Synch + CIDR group received 25 mg of PGF at CIDR removal on Day 7, and 100 μg GnRH on Day 10 and were inseminated concurrently, 66 to 72 hours after CIDR removal. All cows were fitted with a heat detector aid at CIDR removal and were observed twice daily until insemination for estrus and heat detector aid status. Accounting for estrus expression at or before AI (P < 0.0001) and body condition score (P < 0.01), cows in the 5-day CO-Synch + CIDR group had greater AI pregnancy rate compared with cows in the 7-day CO-Synch + CIDR group (58.1% vs. 55.1%; P = 0.04). More cows that exhibited estrus at or before AI became pregnant compared with cows that did not [65.7% (681/1037) vs. 44.5% (347/780); P < 0.0001]. The AI pregnancy rate was lesser for cows with body condition ≤4 [≤4 - 49.3% (101/219), 5-6 - 57.9%; >6 - 55.8%]. The mean AI pregnancy rate difference between treatment groups and projected economic outcome varied among locations. In conclusion, cows synchronized with the 5-day CO-Synch + CIDR protocol had greater AI pregnancy rate than those that received the 7-day CO-Synch + CIDR protocol.

  14. Estrus synchronization and ovarian hyper-stimulation treatments have negligible effects on cumulus oocyte complex gene expression whereas induction of ovulation causes major expression changes.

    PubMed

    Agca, Cansu; Yakan, Akin; Agca, Yuksel

    2013-02-01

    The effects of exogenous hormones, used for estrus synchronization and ovarian hyper stimulation, on cumulus oocyte complexes (COCs) gene expression in sexually mature rats were determined using microarrays. Gene expression in COCs collected from GnRH (G(trt)), GnRH + eCG (G + E(trt)), and GnRH + eCG + hCG (G + E + H(trt)) treatments were compared to COCs from naturally cycling (NC) rats before the preovulatory luteninizing hormone surge. There was no significant difference in gene expression among NC, G(trt), and G + E(trt); however, over 2,600 genes were significantly different between NC and G + E + H(trt) (P < 0.05). Genes upregulated in G + E + H(trt) encode for: proteins that are involved in prostaglandin synthesis (Ptgs2, Pla2g4a, and Runx1) and cholesterol biosynthesis (Hmgcr, Sc4mol, and Dhcr24); receptors that allow cholesterol uptake (Ldlr and Scarb1), regulate progesterone synthesis (Star), and inactivate estrogen (Sult1e1); and downstream effectors of LH signal (Pgr, Cebpb, Creb3l1, Areg, Ereg, and Adamts1). Conversely, G + E + H(trt) downregulated genes encoding proteins involved in: DNA replication and cell cycle progression (Ccne2, Orc5l, Rad50, and Mcm6); reproductive developmental process; and granulosa cell expansion (Gdf9, Bmp15, Amh, Amhr2, Bmpr1b, Tgfb2, Foxl2, Pde3a, Esr2, Fshr, Ybx2, Ccnd2, Ccnb1ip1, and Zp3); maternal effect genes required for embryo development (Zar1, Npm2, Nlrp5, Dnmt1, H1foo, and Zfp57); amino acid degradation; and ketogenesis (Hmgcs2, and Cpt1b). These results from the rat show that hormones used for estrus synchronization (G(trt)) and ovarian hyper stimulation (G + E(trt)) had minimal effects on gene expression, whereas induction of ovulation (G + E + H(trt)) caused major changes in gene expression of rat COCs. This study provides comprehensive information about regulated genes during late follicle development and ovulation induction.

  15. Ovarian follicular dynamics and hormonal profiles in heifer and mixed-parity Mediterranean Italian buffaloes (Bubalus bubalis) following an estrus synchronization protocol.

    PubMed

    Presicce, Giorgio Antonio; Senatore, Elena Maria; Bella, Antonino; De Santis, Giuseppe; Barile, Vittoria Lucia; De Mauro, Guillermo Javier; Terzano, Giuseppina Maria; Stecco, Romana; Parmeggiani, Albamaria

    2004-05-01

    The primary objective was to elucidate ovarian follicular dynamics and hormonal profiles in nulliparous heifer (HE; n = 11 ) and mixed-parity (MP; n=10 ) Mediterranean Italian water buffaloes (Bubalus bubalis) following an estrus synchronization protocol. Both groups received a progesterone releasing intravaginal device (PRID) implant for 10 days; a luteolytic dose of synthetic prostaglandin was given 7 days after PRID insertion. Daily ultrasound monitoring and collection of blood to determine plasma concentrations estradiol and progesterone started 1 day after PRID removal and lasted for 55 and 65 days in HE and MP buffaloes, respectively. Data analysis was restricted to the first 5 days after PRID removal and to one estrus cycle following induced ovulation. The HE buffaloes were not inseminated and only one ovulated within 5 days after PRID removal; the remainder ovulated between 8 and 48 days after PRID removal (except one in which ovulation was never detected). All HP buffaloes were inseminated 72, 96 and 120 h after PRID removal; seven buffaloes ovulated within 5 days after PRID removal and two were pregnant. Mean diameter of the largest follicle was significantly smaller in HE than MP buffaloes the first 4 days after PRID removal. There was a parity by time interaction ( P=0.0047 ) for plasma progesterone concentrations; progesterone was higher in HE than MP buffaloes 1 day after PRID removal, but the converse was true 2 days after PRID removal. After induced ovulation, HE buffaloes exhibited a one-wave ( n=5; length of cycle, 8-12 days), two-wave ( n=4; range: 20-26 days) or three-wave cycle ( n=1; 25 days). In contrast, all non-pregnant MP buffaloes ( n=8 ) had a two-wave cycle (range: 19-25 days). For buffaloes with two-wave cycles, the growth rate and diameter of the largest follicle was significantly smaller in HE than MP buffaloes for both the first follicular wave (1.3mm versus 1.7 mm per day and 10.5 mm versus 13.3 mm, respectively) and the second

  16. Ovarian follicular dynamics and hormonal profiles in heifer and mixed-parity Mediterranean Italian buffaloes (Bubalus bubalis) following an estrus synchronization protocol.

    PubMed

    Presicce, Giorgio Antonio; Senatore, Elena Maria; Bella, Antonino; De Santis, Giuseppe; Barile, Vittoria Lucia; De Mauro, Guillermo Javier; Terzano, Giuseppina Maria; Stecco, Romana; Parmeggiani, Albamaria

    2004-05-01

    The primary objective was to elucidate ovarian follicular dynamics and hormonal profiles in nulliparous heifer (HE; n = 11 ) and mixed-parity (MP; n=10 ) Mediterranean Italian water buffaloes (Bubalus bubalis) following an estrus synchronization protocol. Both groups received a progesterone releasing intravaginal device (PRID) implant for 10 days; a luteolytic dose of synthetic prostaglandin was given 7 days after PRID insertion. Daily ultrasound monitoring and collection of blood to determine plasma concentrations estradiol and progesterone started 1 day after PRID removal and lasted for 55 and 65 days in HE and MP buffaloes, respectively. Data analysis was restricted to the first 5 days after PRID removal and to one estrus cycle following induced ovulation. The HE buffaloes were not inseminated and only one ovulated within 5 days after PRID removal; the remainder ovulated between 8 and 48 days after PRID removal (except one in which ovulation was never detected). All HP buffaloes were inseminated 72, 96 and 120 h after PRID removal; seven buffaloes ovulated within 5 days after PRID removal and two were pregnant. Mean diameter of the largest follicle was significantly smaller in HE than MP buffaloes the first 4 days after PRID removal. There was a parity by time interaction ( P=0.0047 ) for plasma progesterone concentrations; progesterone was higher in HE than MP buffaloes 1 day after PRID removal, but the converse was true 2 days after PRID removal. After induced ovulation, HE buffaloes exhibited a one-wave ( n=5; length of cycle, 8-12 days), two-wave ( n=4; range: 20-26 days) or three-wave cycle ( n=1; 25 days). In contrast, all non-pregnant MP buffaloes ( n=8 ) had a two-wave cycle (range: 19-25 days). For buffaloes with two-wave cycles, the growth rate and diameter of the largest follicle was significantly smaller in HE than MP buffaloes for both the first follicular wave (1.3mm versus 1.7 mm per day and 10.5 mm versus 13.3 mm, respectively) and the second

  17. LH peak and ovulation after two different estrus synchronization treatments in buffalo cows in the daylight-lengthening period.

    PubMed

    Barile, V L; Terzano, G M; Pacelli, C; Todini, L; Malfatti, A; Barbato, O

    2015-07-15

    The aim of this study was to determine the timing of ovulation in relation to the LH peak after synchronization using PRID or Ovsynch protocols, to assess the effects of the period of treatment on these parameters and to provide information concerning how to use the two main protocols for fixed-time artificial insemination in buffalo. Forty-eight lactating Italian Mediterranean buffalo cows were used. The buffaloes were treated in various periods as follows: February to March (n = 12 PRID, n = 12 Ovsynch), end of the breeding season, May to June (n = 12 PRID, n = 12 Ovsynch), beginning of low-breeding season according to Italian environmental conditions. To determine the LH, blood samples were taken at 4-hour intervals, starting 24 hours from PRID removal (PRID group) or 12 hours from (PGF2α) injection (Ovsynch group) up to 108 hours. The ovaries were monitored by transrectal ultrasonography to verify ovulation. The LH-ovulation interval was similar in both groups (30.10 ± 1.05 and 32.77 ± 1.15 hours, respectively, in PRID and Ovsynch group). In the PRID group, the timing of ovulation in relation to device removal was 76.83 ± 3.65 hours with a high level of variability among the animals. In the Ovsynch group, we observed a better synchronization of LH peaks and ovulations, and the timing of ovulation in relation to the last GnRH injection was 35.67 ± 1.15 hours. The percentage of animals reaching the LH peak and ovulation was lower (P ≤ 0.05) in May to June (respectively 75.0% and 54.1%) compared to February to March (respectively 95.8% and 83.3%), indicating a reduction of hypothalamus-pituitary responsiveness to the synchronization treatments in the daylight-lengthening period. PMID:25958084

  18. LH peak and ovulation after two different estrus synchronization treatments in buffalo cows in the daylight-lengthening period.

    PubMed

    Barile, V L; Terzano, G M; Pacelli, C; Todini, L; Malfatti, A; Barbato, O

    2015-07-15

    The aim of this study was to determine the timing of ovulation in relation to the LH peak after synchronization using PRID or Ovsynch protocols, to assess the effects of the period of treatment on these parameters and to provide information concerning how to use the two main protocols for fixed-time artificial insemination in buffalo. Forty-eight lactating Italian Mediterranean buffalo cows were used. The buffaloes were treated in various periods as follows: February to March (n = 12 PRID, n = 12 Ovsynch), end of the breeding season, May to June (n = 12 PRID, n = 12 Ovsynch), beginning of low-breeding season according to Italian environmental conditions. To determine the LH, blood samples were taken at 4-hour intervals, starting 24 hours from PRID removal (PRID group) or 12 hours from (PGF2α) injection (Ovsynch group) up to 108 hours. The ovaries were monitored by transrectal ultrasonography to verify ovulation. The LH-ovulation interval was similar in both groups (30.10 ± 1.05 and 32.77 ± 1.15 hours, respectively, in PRID and Ovsynch group). In the PRID group, the timing of ovulation in relation to device removal was 76.83 ± 3.65 hours with a high level of variability among the animals. In the Ovsynch group, we observed a better synchronization of LH peaks and ovulations, and the timing of ovulation in relation to the last GnRH injection was 35.67 ± 1.15 hours. The percentage of animals reaching the LH peak and ovulation was lower (P ≤ 0.05) in May to June (respectively 75.0% and 54.1%) compared to February to March (respectively 95.8% and 83.3%), indicating a reduction of hypothalamus-pituitary responsiveness to the synchronization treatments in the daylight-lengthening period.

  19. Effects of season and ovarian status on the outcome of long-term progesterone-based estrus synchronization protocols and ovulatory follicle development in Santa Inês ewes under subtropical conditions.

    PubMed

    Oliveira, M E F; Ayres, H; Oliveira, L G; Barros, F F P C; Oba, E; Bicudo, S D; Bartlewski, P M; Fonseca, J F; Vicente, W R R

    2016-02-01

    This study set out to investigate the efficiency of long-term estrus synchronization protocols and ovulatory follicle dynamics in ultrasonographically monitored Santa Inês ewes during lengthening (LD; September-October) and shortening photoperiods (SD; April-May), and the transitional period (TP; January). In addition, the influence of ovarian status (e.g., size of antral follicles and/or presence of corpora lutea) at the outset of the estrus synchronization protocols on the ensuing development of ovulatory follicles was examined. Seventy sexually mature Santa Inês ewes were subjected to one of the two estrus synchronization regimens; on Day 0 (random day of the estrous cycle or anovulatory period), the ewes were fitted with an intravaginal progesterone (P4)-releasing (controlled intrauterine drug release [CIDR]) device, which was left in place for 14 days (G-1CIDR, n = 35) or replaced on Day 7 (G-2CIDR, n = 35), and received an intramuscular injection of 10 mg of PGF2α. The ewes allocated to the G-1CIDR group had mean serum P4 concentrations less than 2 ng/mL during the last 4 days of the synchronization protocol. There were no differences (P > 0.05) in mean ovulation rates between the two protocols tested nor among the ewes varying in ovarian status or studied at different times of the year, but ovulations occurred ∼ 12 hours later in the TP compared with the SD period (P < 0.05). Ovulatory follicles emerged earlier (P < 0.05) in the G-1CIDR group than in the G-2CIDR group (Day 8.3 ± 0.5 vs. 9.2 ± 0.4) and during LD (Day 7.1 ± 0.6) compared with the TP (Day 9.1 ± 0.6) and SD (Day 9.9 ± 0.5 of the protocol). In conclusion, the replacement of CIDR devices prevented the occurrence of lower-than-normal luteal phase levels of P4 at the end of the 14-day estrus synchronization protocol. However, although this procedure and seasonal influences altered certain growth characteristics of ovulatory follicles, there were no effects of these factors on the mean

  20. Control of estrus and ovulation in beef heifers.

    PubMed

    Patterson, David J; Thomas, Jordan M; Martin, Neal T; Nash, Justin M; Smith, Michael F

    2013-11-01

    Expanded use of artificial insemination (AI) and/or adoption of emerging reproductive technologies for beef heifers and cows require precise methods of estrous-cycle control. New protocols for inducing and synchronizing a fertile estrus in replacement beef heifers and postpartum beef cows in which progestins are used provide new opportunities for beef producers to synchronize estrus and ovulation and to facilitate fixed-time AI. This article reviews the various estrous synchronization protocols currently available for use in replacement beef heifers. New methods of inducing and synchronizing estrus now create the opportunity to significantly expand the use of AI in the United States cowherd. PMID:24182437

  1. Control of estrus and ovulation in beef heifers.

    PubMed

    Patterson, David J; Thomas, Jordan M; Martin, Neal T; Nash, Justin M; Smith, Michael F

    2013-11-01

    Expanded use of artificial insemination (AI) and/or adoption of emerging reproductive technologies for beef heifers and cows require precise methods of estrous-cycle control. New protocols for inducing and synchronizing a fertile estrus in replacement beef heifers and postpartum beef cows in which progestins are used provide new opportunities for beef producers to synchronize estrus and ovulation and to facilitate fixed-time AI. This article reviews the various estrous synchronization protocols currently available for use in replacement beef heifers. New methods of inducing and synchronizing estrus now create the opportunity to significantly expand the use of AI in the United States cowherd.

  2. Effect of estradiol cypionate and amount of progesterone in the intravaginal device on synchronization of estrus, ovulation and on pregnancy rate in beef cows treated with FTAI based protocols.

    PubMed

    Uslenghi, Gastón; Chaves, Santiago González; Cabodevila, Jorge; Callejas, Santiago

    2014-02-01

    Three experiments were conducted to evaluate the effect of estradiol cypionate (ECP) and amount of progesterone in the intravaginal device (PID) on synchronization of estrus and ovulation, follicular dynamics, luteal dynamics and function and on pregnancy rate in beef cows treated with fixed-time artificial insemination (FTAI) based protocols. In Experiment 1, we evaluated the synchronization of ovulation using 1mg of ECP at PID removal (day 8 after PID insertion) or 1mg of estradiol benzoate (EB) 24h later, in cows treated with 0.558 or 1g of progesterone (P4). The final subgroups were: 0.558g+ECP: n=10; 0.558g+EB: n=11; 1g+ECP: n=10; 1g+EB: n=10. Ovarian ultrasonic examinations were performed to detect the dominant follicle and ovulation. There was no effect of treatments on the diameter of dominant follicle at any time, and on the mean interval to estrus and to ovulation (P>0.05); however, ECP treated cows had scattered distribution of estrus (P<0.03) and ovulation (P<0.03). In Experiment 2, cows received the following treatments: 0.558gP4+ECP: n=52; 0.558gP4+EB: n=52; 1gP4+ECP: n=50; 1gP4+EB: n=52; and FTAI. Pregnancy rate did not differ (P>0.05) between progesterone content (0.558g: 52.9%, 55/104; 1g: 56.9%, 58/102) but differed between estradiol esters (P<0.05; ECP: 48.9%, 49/102; EB: 61.5%, 64/104). In Experiment 3, cows received: 0.558gP4+ECP: n=55; 0.558gP4+EB: n=53; 1gP4+ECP: n=54; 1gP4+EB: n=53; and FTAI. Pregnancy rate did not differ (P>0.05) between progesterone content (0.558g: 48.1%, 52/108; 1g: 53.3%, 57/107) and estradiol esters (ECP: 47.7%, 52/109; EB: 53.8%, 57/106). In conclusion, ECP administration at device removal and progesterone content of PID has no influence on the synchronization of estrus, follicular dynamics, luteal dynamics and function. However, ECP administration affected the synchronization of ovulation and pregnancy rate in non-suckling beef cows, but did not affected pregnancy rate in suckling beef cows. Future studies should

  3. Effects of breed and progestin source on estrus synchronization and rates of fertility and fecundity in Iranian Sanjabi and Lori ewes.

    PubMed

    Moeini, M M; Moghaddam, A A; Bahirale, A; Hajarian, H

    2007-11-01

    A trial was conducted to evaluate the effects of FGA (Fluorogestone acetate) and CIDR (Controlled internal drug release) on the induction of estrus and pregnancy and fecundity rates of the Sanjabi and Lori sheep. A total of 360 Sanjabi and Lori sheep were randomly grouped into two treatments with intravaginal devices inserted for 13 days: Group FGA (40 mg FGA, n = 180) and Group CIDR (n = 180). All ewes received an i.m. injection of 400 IU eCG (equine chorionic gonadotrophin) at devices removal. Estrous was assessed by exposing all ewes to vasectomized rams at 12 h intervals. Cervical artificial insemination was performed 12 h after estrus onset. The overall estrus response was 72.5%. The source of progestin did not influence the efficiency of estrus response but a significant difference (p<0.05) was found between the breed groups (Lori: 88.6%, Sanjabi: 58.3%). Among the sheep that received either CIDR or FGA, estrus response was significantly (p<0.05) higher in the Lori (CIDR: 82.2%, FGA: 91.1%) than in the Sanjabi (CIDR: 64.4%, FGA: 52.2%) breed. The lambing and fecundity rates for all groups were 60.2% and 1.2 +/- 0.03, respectively. No significant differences in term of the lambing and fecundity rates were recorded between CIDR and FGA groups and among Lori and Sanjabi breed. The results of this study indicate the source of progestin or sheep breed did not influence the pregnancy and fecundity rates. The sheep breed influences the estrous response rate while the source of progestin did not affect the estrous response.

  4. Environmental, genetic and social factors affecting the expression of estrus in beef cows.

    PubMed

    Landaeta-Hernández, Antonio J; Yelich, Joel V; Lemaster, J Willard; Fields, Michael J; Tran, Than; Chase, Chad C; Rae, D Owen; Chenoweth, Peter J

    2002-03-01

    Genetic, social and environmental factors affecting behavioral estrus were evaluated in Angus (n = 10), Brahman (n = 10) and Senepol (n = 10) cows during a PGF2alpha synchronized estrus and subsequent spontaneous estrus. Cows were equally stratified by breed to two groups of 15. Both groups were pre-synchronized with a modified two-injection PGF2alpha protocol. At the start of the experiment, cows were treated with 25 mg PGF2alpha followed by a second and third administration of 12.5 mg PGF2alpha, 11 and 12 days later to induce synchronized estrus. The subsequent estrus was designated as spontaneous estrus. Behavioral estrus data including the onset and end of estrus, estrous duration and the total number of mounts received for the synchronized and spontaneous estruses were collected using HeatWatch". Interval from the third PGF2alpha, treatment to the onset of a HeatWatch" estrus occurred earlier (P < 0.05) in Angus (31 +/- 5 h) than Brahman (53 +/- 7 h) or Senepol (53 +/- 4 h) cows, with dominant Senepol and Brahman cows taking longer to exhibit estrus after PGF2alpha than subordinate cows. The duration of the synchronized estrus tended to be shorter (P < 0.06) in Senepol (12 +/- 3 h) than in Angus (19 +/- 2 h) or Brahman (17 +/- 2 h) cows. Behavioral estrus data between the two periods were confounded by greater temperature-humidity index (THI) values during spontaneous estrus. The THI during spontaneous estrus appeared (P = 0.09) to affect the duration of estrus (9 +/- 1 h versus 16 +/- 1 h) and did affect (P < 0.0001) the total number of mounts received (8 +/- 4 mounts versus 34 +/- 4 mounts) during spontaneous estrus compared to synchronized estrus. Breed had no effect (P > 0.10) on the duration and total number of mounts received during synchronized and spontaneous estruses. In conclusion, type of estrus (synchronized or spontaneous), THI, social dominance and breed exerted significant effects on characteristics associated with behavioral estrus in beef

  5. Efficacy of PGF(2alpha) to synchronize estrus in water buffalo cows (Bubalus bubalis) is dependent upon plasma progesterone concentration, corpus luteum size and ovarian follicular status before treatment.

    PubMed

    Brito, L F C; Satrapa, R; Marson, E P; Kastelic, J P

    2002-09-16

    This study was conducted to identify factors affecting PGF(2alpha) efficacy to synchronize estrus in water buffalo cows. After detection of a corpus luteum (CL) by rectal palpation, cows were treated (im) with dinoprost (12.5, 25 or 50mg) or D(+) cloprostenol (75, 150 or 300 microg) in a total of 66 treatments. Blood samples were collected 0, 24 and 48 h after treatment and ultrasound examinations and observations for estrus were performed daily to the day of ovulation or to 6 days after treatment. No PGF(2alpha) dose-response pattern was observed and overall rates of luteal regression (progesterone <1.0 ng/ml at 48 h), estrus, no detected behavioral estrus with ovulation occurring, and ovulation were 71.2, 36.4, 19.7 and 54.5%, respectively. To analyze plasma progesterone concentrations and ovarian dynamics, cows were divided in three groups according to their response to treatment. Cows that failed to have ovulations from a follicle after treatment (Group A, n = 30) had (P < 0.05) a lower plasma progesterone concentration (2.98 ng/ml) and smaller CL area (CLA; 187.3 mm(2)) before treatment as compared with cows that had an ovulation from a follicle (4.43 ng/ml and 223.7 mm(2), respectively; Groups B and C, n = 36). In cows that failed to ovulate, plasma progesterone concentration decreased in the first 24 h, but did not decline further and was >1.0 ng/ml 48 h after treatment. Moreover, no significant change in CLA after treatment was detected, indicating that treatment induced only partial luteolysis. In cows that ovulated, plasma progesterone concentration and CLA decreased continuously from treatment to ovulation (consistent with complete luteolysis). Threshold values of 2.8 ng/ml for plasma progesterone concentration and 189 mm(2) for CLA were identified as the best predictors of ovulation before treatment (83.3 and 80.6% sensitivity and 58.6 and 65.5% specificity, respectively, with positive and negative predictive values around 71%). When the origin of the

  6. Effect of gonadotropin-releasing hormone or prostaglandin F(2α)-based estrus synchronization programs for first or subsequent artificial insemination in lactating dairy cows.

    PubMed

    Bruno, R G S; Farias, A M; Hernández-Rivera, J A; Navarrette, A E; Hawkins, D E; Bilby, T R

    2013-03-01

    The objective was to evaluate the effects of GnRH or PGF(2α)-based synchronization and resynchronization programs on fertility in lactating dairy cows. For experiment 1, cows (n=1,521) were presynchronized with 2 injections of PGF given at 36 and 50 DIM and assigned to 1 of 3 protocols: Ovsynch [OVS; n=552; GnRH injection, PGF(2α) injection 7 d later, GnRH injection 56 h later, and timed artificial insemination (TAI) 16 h later] beginning at 14 d after presynchronization (PS), GnRH-GnRH-PGF(2α)-GnRH (GGPG; n=402) treatment with a GnRH injection given 7 d after PS and OVS 7 d later, or PGF(2α)-GnRH-PGF(2α)-GnRH (P7GPG; n=567) treatment with a PGF(2α) injection given 7 d after PS and OVS beginning 7 d later. Experiment 2 cows (n=2,327) were assigned to 1 of 3 resynchronization protocols 7 d before nonpregnancy diagnosis (NPD): GGPG cows (n=458) received a GnRH injection at enrollment and OVS at NPD; P7GPG cows (n=940) received a PGF(2α) injection at NPD and OVS 7 d later; and P11GPG cows (n=929) received a PGF(2α) injection 3 d after NPD and OVS 11 d later. In both experiments, cows were artificially inseminated upon estrus detection (ED). In experiment 1, 52.3% of cows were artificially inseminated upon ED, with GGPG having reduced ED (GGPG=46.8 vs. OVS=50.7 and P7GPG=57.7%). Treatments did not affect overall pregnancy per artificial insemination (P/AI) at 36 and 66 d after AI (OVS=34.1 and 32.3, P7GPG=34.6 and 31.9, and GGPG=31.3 and 28.1%, respectively) or pregnancy loss but cows artificially inseminated upon ED had higher P/AI than cows undergoing TAI (ED cows=37.9 vs. TAI cows=28.8%). Treatment did not affect P/AI for cows artificially inseminated upon ED or TAI at 36 and 66 d after AI (OVS=34.1 and 32.3, P7GPG=34.6 and 31.9, and GGPG=31.3 and 28.1%). Median days in milk at first AI was affected by treatment (P7GPG=59 vs. OVS=68 and GGPG=68 d). In experiment 2, GGPG reduced ED (GGPG=23.3 vs. P7GPG=74.9 and P11GPG=79.6%). Treatment did not affect overall

  7. New approaches to male non-hormonal contraception.

    PubMed

    Nya-Ngatchou, Jean-Jacques; Amory, John K

    2013-03-01

    A non-hormonal male contraceptive is a contraceptive that does not involve the administration of hormones or hormone blockers. This review will focus on the use of lonidamine derivatives and inhibitors of retinoic acid biosynthesis and function as approaches to male non-hormonal contraception. Two current lonidamine derivatives, adjudin and H2-gamendazole, are in development as male contraceptives. These potent anti-spermatogenic compounds impair the integrity of the apical ectoplasmic specialization, resulting in premature spermiation and infertility. Another approach to male contraceptive development is the inhibition of retinoic acid in the testes, as retinoic acid signaling is necessary for spermatogenesis. The administration of the retinoic acid receptor antagonist BMS-189453 reversibly inhibits spermatogenesis in mice. Similarly, oral dosing of WIN 18,446, which inhibits testicular retinoic acid biosynthesis, effectively contracepts rabbits. Hopefully, one of these approaches to non-hormonal male contraception will prove to be safe and effective in future clinical trials.

  8. Evaluation of reproductive and economic outcomes of dairy heifers inseminated at induced estrus or at fixed time after a 5-day or 7-day progesterone insert-based ovulation synchronization protocol.

    PubMed

    Lopes, G; Johnson, C R; Mendonça, L G D; Silva, P R B; Moraes, J G N; Ahmadzadeh, A; Dalton, J C; Chebel, R C

    2013-03-01

    The objectives of the current experiment were to evaluate the reproductive performance and economic outcome of 3 synchronization strategies for first artificial insemination (AI) of dairy heifers. Holstein heifers from 2 herds (site A, California, n=415; site B, Idaho, n=425) were assigned to 1 of 3 treatments. Heifers assigned to the AI on estrus (AIE) treatment received an injection of 25mg of PGF(2α) at enrollment (d 0) and every 11 d thereafter until AI occurred. Heifers assigned to the CIDR5 treatment received a controlled internal drug release insert (CIDR) containing 1.38 g of progesterone, which was removed 5 d later concomitantly with an injection of 25mg of PGF(2α), and received fixed-time AI (TAI) concomitantly with an injection of 100 μg of GnRH 53 to 60 h later. Heifers assigned to the CIDR7 treatment received a CIDR insert, which was removed 7 d later concomitantly with an injection of 25mg of PGF(2α), and received TAI concomitantly with an injection of 100 μg of GnRH 53 to 60 h later. Heifers were observed for estrus and inseminated up to 98 and 73 d after enrollment in sites A and B, respectively. Thereafter, heifers were moved to pens with bulls and considered failure to conceive to AI if still not pregnant at the end of the observation period. Economic outcomes were based on cost of synchronization protocol (CIDR treatment=$11, PGF(2α) or GnRH treatments=$2.5/treatment, estrous detection=$0.80/heifer per day), rearing cost ($2.75/heifer per day), and economic loss if a heifer did not conceive to first AI ($150). Input cost of the reproductive programs=synchronization protocol cost + semen cost + rearing cost + replacement cost. Pregnancy per AI (P/AI) 38 ± 3 d after first AI was greatest for AIE heifers (61.1%) followed by CIDR5 (44.8%) and CIDR7 (35.7%) heifers. Furthermore, P/AI 73 ± 7 d after first AI was greatest for AIE (58.8%) and tended to be greater for CIDR5 (42%) than for CIDR7 (34.1%) heifers. The percentage of heifers that had

  9. The efficiency of vaginal temperature measurement for detection of estrus in Japanese Black cows

    PubMed Central

    SAKATANI, Miki; TAKAHASHI, Masashi; TAKENOUCHI, Naoki

    2016-01-01

    Recently, weak estrous behavior was assumed to be the cause of a decline in breeding efficiency in cattle. The present study investigated the effect of measuring the vaginal temperature on the detection of estrus in Japanese Black cows. First, the effect of hormone administration to cows with a functional corpus luteum on the vaginal temperature was evaluated by continuous measurement using a temperature data logger. After 24 h of cloprostenol (PG) treatment, the vaginal temperature was significantly lower than on day 7 after estrus, and the low values were maintained until the beginning of estrus (P < 0.05). The cows that received PG and exogenous progesterone (CIDR) did not show a temperature decrease until the CIDR was removed. This finding suggested that the vaginal temperature change reflected the progesterone concentration. The rate of detection of natural estrus was lower for a pedometer than for the vaginal temperature (P < 0.05); synchronization of estrus resulted in a high estrus detection rate regardless of the detection method. In a subsequent experiment, the effect of vaginal temperature measurement and the use of a pedometer on estrus detection was evaluated in the cool and hot seasons. The average activities during non-estrus and the activity increase ratio (estrus/non-estrus) changed according to season (P < 0.01, P < 0.05). However, the average vaginal temperatures during estrus and non-estrus were not affected by season. The estrus detection rate of the pedometer was lower in summer and lower than that obtained using the vaginal temperature. These results indicated that vaginal temperature measurement might be effective for detecting estrus regardless of estrous behavior. PMID:26853785

  10. Expression of estrus before fixed-time AI affects conception rates and factors that impact expression of estrus and the repeatability of expression of estrus in sequential breeding seasons.

    PubMed

    Richardson, Brittany N; Hill, Scott L; Stevenson, Jeffery S; Djira, Gemechis D; Perry, George A

    2016-03-01

    Expression of estrus after PG and before fixed-time AI has been reported to change the uterine environment, increase accessory sperm numbers, fertilization rates, and overall embryo survival. Thus, expression of estrus can strongly impact overall pregnancy success. Because of variation in percentage of beef females detected in estrus and number of animals per study, it can be difficult to detect a significant effect of estrus on pregnancy success. Thus, a meta-analysis was conducted using data from 10,116 beef females in 22 studies that utilized variations of the 5 most common fixed-time AI protocols (CO-Synch, 7-day CO-Synch+CIDR, 5-day CIDR, PG 6-day CIDR, and the 14-day CIDR protocols) to examine the effect of detection in standing estrus on subsequent fixed-time AI pregnancy success. A random-effects model was used to combine the studies/herds. The overall model indicated a positive effect of estrus on conception rates with cows detected in estrus before fixed-time AI having a 27% greater (P<0.05; 95% CI=22-32%) conception rate compared with those not detected in estrus. Next we determined factors that influenced expression of estrus. Data were available on 547 cows synchronized with a CIDR based fixed-time AI protocols and observed for estrus before AI during 2-4 breeding seasons. Analysis of these cows indicated that days postpartum (P=0.22) did not impact estrous expression. In contrast, BCS influenced estrous expression (P=0.04) with cows in a BCS of ≤4 (51±5%) having decreased expression of estrus compared to cows with a BCS>4 (≥70±4%). Initiation of estrous cycles before the breeding season also influenced estrous expression (P=0.03), with anestrous cows having greater expression of estrus compared with estrus-cycling cows (78±5% vs. 70±5%, respectively). In conclusion, among all currently recommended fixed-time AI protocols, cows detected in estrus before fixed-time AI had improved conception rates, with BCS and estrus-cycling status having the

  11. Behavioral and hormonal pattern of repeat breeder cows around estrus.

    PubMed

    Sood, P; Zachut, M; Dube, H; Moallem, U

    2015-06-01

    Repeat breeder (RB) cows were compared with normal (CTRL) ones with respect to behavioral estrus intensity, endocrine patterns and concentrations of plasma estradiol, progesterone and LH around estrus, and ovulation timing. A total of 27 and 31 cycles in 12 RB and 18 CTRL cows, respectively, were synchronized by means of the Ovsynch protocol followed by a single PG injection after 7 days. Behavioral estrus and ovulation were observed in 81.5 and 83.8% of the synchronized cycles in the RB and CTRL cows respectively. The RB and CTRL groups had similar estrus durations of 21.4 and 19.6 h respectively, but estrus was more intense in the RB, as indicated by numerically higher overall activity indexes and higher peak neck activity. The interval from PG injection to estrus onset (considered as proestrus) was 8.2 h shorter in RB than in CTRL cows, at 47.9 and 56.1 h respectively (P<0.007), but the average preovulatory follicle size was similar. The estradiol concentration at peak was numerically higher (21%) and the AUC tended to be higher in the RB cows than in the CTRL cows. LH secretion during the period from 18 to 3 h before the LH peak was also lower in RB than in CTRL cows: 2.5 and 4.6 ng/ml respectively (P<0.01). In conclusion, the behavioral estrus was more intense in the RB cows; nevertheless, short proestrus and subdued LH concentrations before the LH peak, which could impair oocyte competence and development, were first reported in RB cows.

  12. Nonpuberal estrus in beef heifers.

    PubMed

    Rutter, L M; Randel, R D

    1986-10-01

    The frequency of occurrence of behavioral estrus without subsequent development of functional luteal tissue (termed nonpuberal estrus, NPE), was determined in 43 Simmental X Hereford-Brahman heifers. Blood samples were collected weekly from the start of the study to first behavioral estrus and then daily from d 1 (d 0 = estrus) through d 14 following first and subsequently observed estrous behaviors. All blood samples were analyzed for serum progesterone (P4) concentrations by radioimmunoassay. More heifers (62.8%) exhibited NPE than had luteal development after their first behavioral estrus (37.2%). There was a tendency for fewer light-weight heifers (less than or equal to 240 kg at the start of the experiment) to exhibit a puberal first estrus compared with the heavy-weight (greater than 240 kg at the start of the experiment) heifers (31.2% vs 68.8%, respectively; P = .12). Heifers that had a puberal first estrus were older (376 +/- 12 d vs 334 +/- 9 d, P less than .05) compared with heifers that had NPE. Weight at first behavioral estrus was similar between heifers that had a puberal first estrus and those that had NPE (298 +/- 8 kg and 289 +/- 6 kg, respectively). More heifers that had a puberal first estrus also had an elevation in serum P4 concentrations before that first estrus (64.3% vs 20.0%, P less than .05), and the serum P4 elevation was greater (2.5 +/- .4 ng vs 1.2 +/- .1 ng, P less than .05) than heifers that had NPE. We have concluded from these results that NPE is a common occurrence in heifers approaching puberty.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3771388

  13. Nonpuberal estrus in beef heifers.

    PubMed

    Rutter, L M; Randel, R D

    1986-10-01

    The frequency of occurrence of behavioral estrus without subsequent development of functional luteal tissue (termed nonpuberal estrus, NPE), was determined in 43 Simmental X Hereford-Brahman heifers. Blood samples were collected weekly from the start of the study to first behavioral estrus and then daily from d 1 (d 0 = estrus) through d 14 following first and subsequently observed estrous behaviors. All blood samples were analyzed for serum progesterone (P4) concentrations by radioimmunoassay. More heifers (62.8%) exhibited NPE than had luteal development after their first behavioral estrus (37.2%). There was a tendency for fewer light-weight heifers (less than or equal to 240 kg at the start of the experiment) to exhibit a puberal first estrus compared with the heavy-weight (greater than 240 kg at the start of the experiment) heifers (31.2% vs 68.8%, respectively; P = .12). Heifers that had a puberal first estrus were older (376 +/- 12 d vs 334 +/- 9 d, P less than .05) compared with heifers that had NPE. Weight at first behavioral estrus was similar between heifers that had a puberal first estrus and those that had NPE (298 +/- 8 kg and 289 +/- 6 kg, respectively). More heifers that had a puberal first estrus also had an elevation in serum P4 concentrations before that first estrus (64.3% vs 20.0%, P less than .05), and the serum P4 elevation was greater (2.5 +/- .4 ng vs 1.2 +/- .1 ng, P less than .05) than heifers that had NPE. We have concluded from these results that NPE is a common occurrence in heifers approaching puberty.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Expression of estrus improves fertility and decreases pregnancy losses in lactating dairy cows that receive artificial insemination or embryo transfer.

    PubMed

    Pereira, M H C; Wiltbank, M C; Vasconcelos, J L M

    2016-03-01

    The objective was to evaluate if expression of estrus by dairy cattle altered fertility in timed artificial insemination (AI; n=5,430) or timed embryo transfer (ET; n=2,003) programs that used estradiol and progesterone (P4) to synchronize ovulation. Ovarian ultrasonography was performed on d 0 (time of AI) and 7 to determine ovulatory follicle diameter and ovulation. Only cows with a visible corpus luteum on d 7 were used in this study. At the time of controlled internal drug release removal, all cows received a tail-head device for detection of estrus and were considered in estrus when the paint of the device was completely removed by d 0. Circulating P4 concentrations were evaluated on d 7. Pregnancies per AI (P/AI) or ET (P/ET) were determined by ultrasonography on d 32 and 60. At d-32 pregnancy diagnosis, cows with expression of estrus had increased P/AI [no estrus=25.5% (222/846) vs. estrus=38.9% (1,785/4,584)] and P/ET [no estrus=32.7% (193/606) vs. estrus=46.2% (645/1,397)]. Similarly, at d-60 pregnancy diagnosis, expression of estrus increased P/AI [no estrus=20.1% (179/846) vs. estrus=33.3% (1,530/4,584)] and P/ET [no estrus=25.1% (150/606) vs. estrus=37.5% (525/1,397)]. Pregnancy loss was lower in cows that expressed estrus in timed AI [TAI; no estrus=20.1% (43/222) vs. estrus 14.4% (255/1,785)] and timed ET [TET; no estrus=22.7% (43/193) vs. estrus=18.6% (120/645)] compared with cows with no estrus. Independent of expression of estrus cows ovulating either too small or too large of follicles had lower P/AI. No effect of ovulatory follicle diameter on P/ET was noted in cows that expressed estrus; although, cows that did not express estrus tended to have lower P/ET if they ovulated larger follicles. In cows that showed estrus, follicle diameter did not affect pregnancy loss, but cows that did not show estrus and ovulated larger follicles tended to have greater pregnancy loss after TAI and had greater pregnancy loss on TET. A positive effect of d-7 P4

  15. Relationship of ruminal temperature with parturition and estrus of beef cows.

    PubMed

    Cooper-Prado, M J; Long, N M; Wright, E C; Goad, C L; Wettemann, R P

    2011-04-01

    Spring-calving Angus cows (n = 30) were used to evaluate changes in ruminal temperature (RuT) related to parturition and estrus. Cows were synchronized and artificially inseminated with semen from a single sire. Temperature boluses were placed in the rumen at 7.0 ± 0.2 mo of gestation. Boluses were programmed to transmit RuT every 15 min. Cows (BW = 623 ± 44 kg, BCS = 4.9 ± 0.4) calved during 3 wk, and estrus was synchronized at 77 ± 7 d after calving with PGF(2α). Cows were observed every 12 h to detect estrus. Daily average ambient temperatures ranged from 2 to 22 °C during parturition (February to March) and 17 to 25 °C during estrus (May to June). Ruminal temperature from 7 d before to 3 d after parturition and 2 d before to 2 d after visual detection of estrus was analyzed using the MIXED procedure. Ruminal temperatures <37.72 °C were attributed to water consumption and excluded from analyses. Day did not influence (P = 0.36) RuT from d -2 to -7 before parturition (38.94 ± 0.05 °C). Ruminal temperature decreased (P < 0.001) from d -2 to d -1 before parturition (38.88 ± 0.05 to 38.55 ± 0.05 °C, respectively). Ruminal temperature was not influenced (P = 0.23) by day from 1 d before to 3 d after parturition (38.49 ± 0.05 °C). Ruminal temperature at 0 to 8 h after detection of estrus (38.98 ± 0.09 °C) was greater (P < 0.001) compared with RuT at the same daily hour of the day before (38.37 ± 0.11 °C) or the day after estrus (38.30 ± 0.09 °C). Ambient temperature did not influence (P > 0.30) RuT at parturition or estrus. Ruminal temperature decreased the day before parturition and increased at estrus in spring-calving beef cows and has potential use as a predictor of parturition and estrus.

  16. Effect of copulation on estrus duration and ovulation time in goats.

    PubMed

    Romano, Juan E; Alkar, Abdalhamid; Amstalden, Marcel

    2016-01-15

    The objective of the present study was to evaluate the effect of copulation on estrus duration and ovulation in goats. During the fall season, 14 multiparous Boer does were estrous synchronized with controlled internal drug release (300 mg), maintained in the vagina for 7 days, and received 50 μg of intramuscular GnRH device insertion and 5 mg of natural intramuscular PGF2α at device removal. The does were randomly divided into two equal groups: a treatment group (TRE; n = 7) and a control group (CON; n = 7). The TRE group received two copulas by fertile bucks within the first 4 hours of estrus onset, and the CON group received only mounts by the same males equipped with canvas aprons. Estrus detection was performed every 12 hours after controlled internal drug release removal within the first 24 hours and then every 4 hours for 5 days. Estrus was defined when a doe accepted mounting by the bucks equipped with canvas aprons. Each doe in estrus got the first transrectal ultrasonography at 24 hours after estrus onset and then every 4 hours until all the preovulatory follicles ovulated. Estrus onset for the TRE and CON groups was 40.3 ± 17.4 (mean ± standard deviation) and 43.3 ± 12.2 hours (P = 0.72), respectively. Estrus duration for the same groups was 28.6 ± 5.4 and 36.7 ± 5.3 hours (P = 0.02), respectively. The mean ovulation time for the TRE and CON groups was 31.4 ± 2.2 and 35.7 ± 3.7 hours (P = 0.04), respectively. The proportion of ovulations that occurred after the end of estrus in the TRE group was higher than in the CON group (86% vs. 33%, respectively; P = 0.05). The number of ovulations for the TRE group was 2.1 ± 0.7; for the CON group, there were 2.2 ± 0.5 ovulations (P = 0.92). It was concluded that copulation by a buck at the beginning of estrus reduced estrus duration and hastened the ovulation time in Boer goats.

  17. Determining Proportion of Exfoliative Vaginal Cell during Various Stages of Estrus Cycle Using Vaginal Cytology Techniques in Aceh Cattle

    PubMed Central

    Siregar, Tongku N.; Melia, Juli; Rohaya; Thasmi, Cut Nila; Masyitha, Dian; Wahyuni, Sri; Rosa, Juliana; Nurhafni; Panjaitan, Budianto; Herrialfian

    2016-01-01

    The aim of this study was to investigate the period of estrus cycle in aceh cattle, Indonesia, based on vaginal cytology techniques. Four healthy females of aceh cattle with average weight of 250–300 kg, age of 5–7 years, and body condition score of 3-4 were used. All cattle were subjected to ultrasonography analysis for the occurrence of corpus luteum before being synchronized using intramuscular injections of PGF2 alpha 25 mg. A vaginal swab was collected from aceh cattle, stained with Giemsa 10%, and observed microscopically. Period of estrus cycle was predicted from day 1 to day 24 after estrus synchronization was confirmed using ultrasonography analysis at the same day. The result showed that parabasal, intermediary, and superficial epithelium were found in the vaginal swabs collected from proestrus, metestrus, and diestrus aceh cattle. Proportions of these cells in the particular period of estrus cycle were 36.22, 32.62, and 31.16 (proestrus); 21.33, 32.58, and 46.09 (estrus); 40.75, 37.58, and 21.67 (metestrus); and 41.07, 37.38, and 21.67 (diestrus), respectively. In conclusion, dominant proportion of superficial cell that occurred in estrus period might be used as the base for determining optimal time for insemination. PMID:26977335

  18. Expression and detection of estrus in dairy cows: the role of new technologies.

    PubMed

    Fricke, P M; Carvalho, P D; Giordano, J O; Valenza, A; Lopes, G; Amundson, M C

    2014-05-01

    Despite the widespread adoption of hormonal synchronization protocols that allow for timed artificial insemination (AI), detection of estrus plays an important role in the reproductive management program on most dairies in the United States. Increased physical activity is a secondary sign of estrus in dairy cattle, and a new generation of electronic systems that continuously monitor physical activity to predict timing of AI have been developed and marketed to the dairy industry. A variety of management and physiologic challenges inhibit detection of behavioral estrus on farms, but the prevalence of anouvular cows near the end of the voluntary waiting period is particularly problematic. Only 70% of lactating Holstein cows were detected in estrus when using an activity monitoring system, with the remaining 20% of cows classified as anovular and 10% ovulating without showing signs of activity. Mean time of AI in relation to ovulation based on the activity monitoring system was acceptable for most of the cows with increased activity, however, variability in the duration of estrus and timing of AI in relation to ovulation could result in poor pregnancy outcomes in some cows. Use of a Presynch-Ovsynch protocol for submission of cows for first AI has been widely adopted by dairies in the United States, and a combined approach in which AI based on activity is followed by submission of cows not detected with activity to timed AI after synchronization of ovulation may be an effective strategy for submission of cows to first AI. Based on a field trial on a large commercial dairy in the United States, the activity monitoring system detected 70% of cows with increased activity after the second PGF2α injection of a Presynch-Ovsynch protocol, however, cows inseminated to increased activity had fewer pregnancies per AI (P/AI) compared with cows with increased activity after the second PGF2α injection that received timed AI after completing the Presynch-Ovsynch protocol. Based on

  19. Non-hormonal male contraception: A review and development of an Eppin based contraceptive.

    PubMed

    O'Rand, Michael G; Silva, Erick J R; Hamil, Katherine G

    2016-01-01

    Developing a non-hormonal male contraceptive requires identifying and characterizing an appropriate target and demonstrating its essential role in reproduction. Here we review the development of male contraceptive targets and the current therapeutic agents under consideration. In addition, the development of EPPIN as a target for contraception is reviewed. EPPIN is a well characterized surface protein on human spermatozoa that has an essential function in primate reproduction. EPPIN is discussed as an example of target development, testing in non-human primates, and the search for small organic compounds that mimic contraceptive antibodies; binding EPPIN and blocking sperm motility. Although many hurdles remain before the success of a non-hormonal male contraceptive, continued persistence should yield a marketable product.

  20. Synchronization and Artificial Insemination Strategies in Beef Cattle.

    PubMed

    Lamb, Graham Clifford; Mercadante, Vitor R G

    2016-07-01

    Utilization of estrus or ovulation synchronization and fixed-timed artificial insemination (TAI) has facilitated the widespread utilization of artificial insemination (AI) and can greatly impact the economic viability of cow-calf systems by enhancing weaning weights. Implementation of TAI programs by beef producers results in limited frequency of handling cattle and elimination of the need to detect estrus. Continued use of intensive reproductive management tools such as estrus synchronization and AI will result positive changes to calving distribution, pregnancy rates, and subsequent calf value. PMID:27140297

  1. Estrus behavior and fecal steroid profiles in the Asiatic lion (Panthera leo persica) during natural and gonadotropin-induced estrus.

    PubMed

    Umapathy, Govindhaswamy; Sontakke, Sadanand D; Srinivasu, K; Kiran, Thomas; Kholkute, S D; Shivaji, S

    2007-10-01

    In this paper the behavior of the Asiatic lion was studied during natural and gonadotropin-induced estrus in relation to fecal estradiol and progesterone concentration. The average length of estrus was 5.4 days and no significant difference was observed between natural and gonadotropin-induced estrus. Vocalization and rolling were the major estrus behavioral activities of Asiatic lions and the frequency of these activities were similar in both natural and gonadotropin-induced estrus and treatment with exogenous gonadotropin did not alter estrus behavioral activities. A significant positive correlation was observed between fecal estradiol and frequency of estrus behavior during natural and gonadotropin-induced estrus. Following gonadotropin treatment estrus could be induced in 69% of animals and these induced animals ovulated following hCG treatment. This study reports for the first time the successful use of the non-invasive fecal steroid assay for monitoring the induction of estrus and ovulation in the Asiatic lion.

  2. Behavioral and physiological changes around estrus events identified using multiple automated monitoring technologies.

    PubMed

    Dolecheck, K A; Silvia, W J; Heersche, G; Chang, Y M; Ray, D L; Stone, A E; Wadsworth, B A; Bewley, J M

    2015-12-01

    This study included 2 objectives. The first objective was to describe estrus-related changes in parameters automatically recorded by the CowManager SensOor (Agis Automatisering, Harmelen, the Netherlands), DVM bolus (DVM Systems LLC, Greeley, CO), HR Tag (SCR Engineers Ltd., Netanya, Israel), IceQube (IceRobotics Ltd., Edinburgh, UK), and Track a Cow (Animart Inc., Beaver Dam, WI). This objective was accomplished using 35 cows in 3 groups between January and June 2013 at the University of Kentucky Coldstream Dairy. We used a modified Ovsynch with G7G protocol to partially synchronize ovulation, ending after the last PGF2α injection (d 0) to allow estrus expression. Visual observation for standing estrus was conducted for four 30-min periods at 0330, 1000, 1430, and 2200h on d 2, 3, 4, and 5. Eighteen of the 35 cows stood to be mounted at least once during the observation period. These cows were used to compare differences between the 6h before and after the first standing event (estrus) and the 2wk preceding that period (nonestrus) for all technology parameters. Differences between estrus and nonestrus were observed for CowManager SensOor minutes feeding per hour, minutes of high ear activity per hour, and minutes ruminating per hour; twice daily DVM bolus reticulorumen temperature; HR Tag neck activity per 2h and minutes ruminating per 2h; IceQube lying bouts per hour, minutes lying per hour, and number of steps per hour; and Track a Cow leg activity per hour and minutes lying per hour. No difference between estrus and nonestrus was observed for CowManager SensOor ear surface temperature per hour. The second objective of this study was to explore the estrus detection potential of machine-learning techniques using automatically collected data. Three machine-learning techniques (random forest, linear discriminant analysis, and neural network) were applied to automatically collected parameter data from the 18 cows observed in standing estrus. Machine learning

  3. The male effect, mounting behavior, and the onset of estrus in farmed muskoxen.

    PubMed

    Rowell, J E; Sousa, M C; Shipka, M P

    2003-11-01

    Muskox farming is an emerging industry in Alaska. For such an endeavor to succeed, it is necessary to develop fundamental husbandry tools specifically for this species. This study examined the role of the bull in the onset of seasonal ovarian activity and the synchrony of estrus and tested the efficacy of a radiotelemetric estrus detection system. Twenty parous female muskoxen, ranging in age from 4 to 15 yr, were divided into three groups (balanced by age and body weight). Groups received early bull exposure (EBE; August 1, n = 7), late bull exposure (LBE; August 22, n = 6), or remained physically isolated from a bull (NBE; n = 7). Just before bull introduction, radiotelemetry transmitters were attached to the rump of muskox cows in the EBE and LBE groups. Plasma samples were collected from all the cows twice weekly and analyzed for progesterone (P4). The mean date of onset of seasonal ovarian activity was earlier in the EBE and LBE groups than in the NBE group (P < 0.001) and was earlier in EBE (P < 0.021) than in LBE. All EBE and LBE cows conceived to the first fertile cycle, giving 100% fertility. The time interval for the onset of ovarian activity between the first and last cow within each group was 7 d in the EBE group, 12 d in the LBE group, and 24 d in the NBE group. Radiotelemetry correctly identified estrus 95% of the time (18 of 19 instances). Mean length of estrus for each cow, calculated from the time of first mount until last mount, was 771 +/- 98 min (range = 4 to 1,508 min). Mean number of mounts during estrus was 8.89 +/- 1.29 (range = 3 to 25 mounts). Length of estrus at the first short cycle did not differ from the length of the first fertile estrus between, or within, individuals. Estrous behavior was initiated more frequently during the night (2300 to 0500; P < 0.05). Bull introduction can be used as a simple, low-cost management tool for synchronizing estrus in farmed muskoxen. Radiotelemetry was an effective tool for identifying breeding

  4. The male effect, mounting behavior, and the onset of estrus in farmed muskoxen.

    PubMed

    Rowell, J E; Sousa, M C; Shipka, M P

    2003-11-01

    Muskox farming is an emerging industry in Alaska. For such an endeavor to succeed, it is necessary to develop fundamental husbandry tools specifically for this species. This study examined the role of the bull in the onset of seasonal ovarian activity and the synchrony of estrus and tested the efficacy of a radiotelemetric estrus detection system. Twenty parous female muskoxen, ranging in age from 4 to 15 yr, were divided into three groups (balanced by age and body weight). Groups received early bull exposure (EBE; August 1, n = 7), late bull exposure (LBE; August 22, n = 6), or remained physically isolated from a bull (NBE; n = 7). Just before bull introduction, radiotelemetry transmitters were attached to the rump of muskox cows in the EBE and LBE groups. Plasma samples were collected from all the cows twice weekly and analyzed for progesterone (P4). The mean date of onset of seasonal ovarian activity was earlier in the EBE and LBE groups than in the NBE group (P < 0.001) and was earlier in EBE (P < 0.021) than in LBE. All EBE and LBE cows conceived to the first fertile cycle, giving 100% fertility. The time interval for the onset of ovarian activity between the first and last cow within each group was 7 d in the EBE group, 12 d in the LBE group, and 24 d in the NBE group. Radiotelemetry correctly identified estrus 95% of the time (18 of 19 instances). Mean length of estrus for each cow, calculated from the time of first mount until last mount, was 771 +/- 98 min (range = 4 to 1,508 min). Mean number of mounts during estrus was 8.89 +/- 1.29 (range = 3 to 25 mounts). Length of estrus at the first short cycle did not differ from the length of the first fertile estrus between, or within, individuals. Estrous behavior was initiated more frequently during the night (2300 to 0500; P < 0.05). Bull introduction can be used as a simple, low-cost management tool for synchronizing estrus in farmed muskoxen. Radiotelemetry was an effective tool for identifying breeding

  5. Efficiency of the OVATEC unit for estrus detection and calf sex control in beef cows.

    PubMed

    Wehner, G R; Wood, C; Tague, A; Barker, D; Hubert, H

    1997-03-01

    Seventy five spring calving Gelbvieh and Angus cows were utilized over a three year period to evaluate the usefulness of the OVATEC intravaginal probe for indicating the onset of estrus and providing the possibility to influence the sex of the offspring by choosing a breeding time in relation to critical changes in cervical mucus conductivity. Cows were randomly assigned by breed each year into one of four treatments: (1) probed and inseminated when impedance values declined, creating conditions expected to favor X-bearing sperm and with it an increase in the conception of females (PF); (2) probed and inseminated when impedance values were rebounding, expected to favor Y-bearing sperms and with it an increase in the conception of males (PB); (3) standing estrus (AI); or (4) natural service by bull (NS). Cows grazed or were fed hay from tall fescue-legume pastures. Lutalyse was used to synchronize estrus in a two injection scheme. Vaginal probe readings were taken at first injection, second injection and every 12 h thereafter for 6 days. Visual observations for estrus were obtained for PF, PB and AI every 12 h postsecond injection. Rectal palpations of ovaries were obtained at standing heat in all but NS treatments. In cycling cows, probe readings increased prediction of estrus onset (P < 0.10) compared to visual observations and were similar (P > 0.95) to rectal palpations in all probed cows. PF cows delivered heifer calves at greater rates (P < 0.025) than all other treatments whereas PB cows delivered bulls at greater rates (P < 0.05) than all other treatments. Heifer to bull ratios were not different (P > 0.95) for AI or NS treatments. The results of this study indicate that the potential exists for increasing female offspring conceptions utilizing cervical mucus conductivity as a gauge for insemination times. PMID:9231244

  6. Trypanosoma cruzi: the development of estrus cycle and parasitemia in female mice maintained with or without male pheromones.

    PubMed

    Schuster, J P; Schaub, G A

    2001-12-01

    Female BALB/c or C57B1/6 mice, kept in small groups of three or five animals with or without male odor, all had a similar progesterone and corticosterone level, mean number of estrus and duration of estrus cycle. However, if males were kept in the same room, the mean duration of the estrus cycle was longer for both strains; and C57B1/6 females had a significantly higher number of estrus than BALB/c mice and showed a tendency to synchronize the estrus cycle within a group. After infection of females of both mouse strains with vector-derived metacyclic trypomastigotes of Trypanosoma cruzi, anestrus with intense phlegm production occurred during the acute phase of infection and this was positively correlated with higher parasitemia. Within individual groups of BALB/c mice, the female with the relatively highest corticosterone and progesterone level had the lowest parasitemia. In groups kept separate from male pheromones, one or two females in each group developed high parasitemias.

  7. Estrus response and fertility of Menz and crossbred ewes to single prostaglandin injection protocol.

    PubMed

    Mekuriaw, Zeleke; Assefa, Habtemariam; Tegegne, Azage; Muluneh, Dagne

    2016-01-01

    Natural lambing in sheep in Ethiopia occurs throughout the year in a scattered manner negatively affecting survival and growth rates of the lambs born during the unfavorable season of the year. Thus, controlling the time of mating artificially using exogenous source of hormones is considered as one of the ways to mitigated problems related to haphazard lambing. To this end, an experiment was conducted to evaluate efficacy of prostaglandin-based estrus synchronization protocol in local and crossbred ewes. A total of 160 ewes (80 local and 80 crossbreds) which lambed at least once and aged 3-5 years were used. Lutalyse® (dinoprost tromethamine sterile solution equivalent to 5 mg dinoprost per ml) and its analog, Synchromate® (cloprostenol sodium equivalent to 0.250 mg cloprostenol per ml), were tested at different doses. The treatments used were intramuscular injection of (1) 2.50 ml of Lutalyse® (12.5 mg dinoprost tromethamine), (2) 2 ml of Lutalyse® (10.0 mg dinoprost tromethamine), (3) 1 ml of Synchromate® (0.25 mg of cloprostenol Sodium), and (4) 0.8 ml of Synchromate® (0.20 mg of cloprostenol Sodium). Forty ewes (20 local and 20 crossbreds) were allocated per treatment. Following injection of the respective hormones, rams of known fertility were introduced into the flock for the duration of 96 h at the ratio of one ram to 10 ewes. All estrus synchronization protocols except treatment 4 (0.8 ml of Synchromate®) induced estrus (heat) in majority (55-65%) of local and crossbred ewes within 96 h post-hormone injection. The time interval from hormone administration to onset of estrus was also more or less similar for all treatment groups except for treatment group 4 which showed heat quicker. The highest lambing rate was recorded in local ewes (84.62% (11/13) treated with 2.5 ml of Lutalyse®, whereas the least was obtained in crossbreds (33.33% (3/9) treated with 0.8 ml Synchromate®. In conclusion, even though 2.5 ml and 2 ml of Lutalyse® or 1 ml of

  8. Estrus response and fertility of Menz and crossbred ewes to single prostaglandin injection protocol.

    PubMed

    Mekuriaw, Zeleke; Assefa, Habtemariam; Tegegne, Azage; Muluneh, Dagne

    2016-01-01

    Natural lambing in sheep in Ethiopia occurs throughout the year in a scattered manner negatively affecting survival and growth rates of the lambs born during the unfavorable season of the year. Thus, controlling the time of mating artificially using exogenous source of hormones is considered as one of the ways to mitigated problems related to haphazard lambing. To this end, an experiment was conducted to evaluate efficacy of prostaglandin-based estrus synchronization protocol in local and crossbred ewes. A total of 160 ewes (80 local and 80 crossbreds) which lambed at least once and aged 3-5 years were used. Lutalyse® (dinoprost tromethamine sterile solution equivalent to 5 mg dinoprost per ml) and its analog, Synchromate® (cloprostenol sodium equivalent to 0.250 mg cloprostenol per ml), were tested at different doses. The treatments used were intramuscular injection of (1) 2.50 ml of Lutalyse® (12.5 mg dinoprost tromethamine), (2) 2 ml of Lutalyse® (10.0 mg dinoprost tromethamine), (3) 1 ml of Synchromate® (0.25 mg of cloprostenol Sodium), and (4) 0.8 ml of Synchromate® (0.20 mg of cloprostenol Sodium). Forty ewes (20 local and 20 crossbreds) were allocated per treatment. Following injection of the respective hormones, rams of known fertility were introduced into the flock for the duration of 96 h at the ratio of one ram to 10 ewes. All estrus synchronization protocols except treatment 4 (0.8 ml of Synchromate®) induced estrus (heat) in majority (55-65%) of local and crossbred ewes within 96 h post-hormone injection. The time interval from hormone administration to onset of estrus was also more or less similar for all treatment groups except for treatment group 4 which showed heat quicker. The highest lambing rate was recorded in local ewes (84.62% (11/13) treated with 2.5 ml of Lutalyse®, whereas the least was obtained in crossbreds (33.33% (3/9) treated with 0.8 ml Synchromate®. In conclusion, even though 2.5 ml and 2 ml of Lutalyse® or 1 ml of

  9. Video tracking analysis of behavioral patterns during estrus in goats

    PubMed Central

    ENDO, Natsumi; RAHAYU, Larasati Puji; ARAKAWA, Toshiya; TANAKA, Tomomi

    2015-01-01

    Here, we report a new method for measuring behavioral patterns during estrus in goats based on video tracking analysis. Data were collected from cycling goats, which were in estrus (n = 8) or not in estrus (n = 8). An observation pen (2.5 m × 2.5 m) was set up in the corner of the female paddock with one side adjacent to a male paddock. The positions and movements of goats were tracked every 0.5 sec for 10 min by using a video tracking software, and the trajectory data were used for the analysis. There were no significant differences in the durations of standing and walking or the total length of movement. However, the number of approaches to a male and the duration of staying near the male were higher in goats in estrus than in goats not in estrus. The proposed evaluation method may be suitable for detailed monitoring of behavioral changes during estrus in goats. PMID:26560676

  10. The estrus detection problem: new concepts, technologies, and possibilities.

    PubMed

    Senger, P L

    1994-09-01

    The single most important problem limiting high reproductive efficiency in the national dairy herd is poor detection of estrus. Failure to detect estrus or erroneous diagnosis of estrus results in an estimated annual loss of over $300 million to the dairy industry in the US. New technologies for the solution of this problem must be more effective than visual observation and aids currently used to detect estrus. Ideally, technologies that provide the solution for detection problems should provide the following: continuous (24 h/d) surveillance of the cow, accurate and automatic identification of cows in estrus, operation for the productive lifetime of the cow, minimized labor requirements, and high accuracy in identifying the appropriate physiologic or behavioral events that correlate highly with ovulation. New approaches are aimed at providing automation of detection of estrus using electronic technology. Pedometry, implantable impedance sensors, and surface-applied and implantable pressure sensors are in various stages of development and use.

  11. Relationship between growth of the preovulatory follicle and its steroidogenic activity on the onset and expression of estrus behavior in CIDR-treated Bos indicus cows: an observational study.

    PubMed

    Diaz, Daniel; Galina, Carlos S; Fiordelisio, Tatiana; Rubio, Ivette; Alarcon, Marco A; Rodriguez, Ana D; Orihuela, Agustin

    2012-09-10

    Estrus synchronization induces cows to gather in sexually active groups (SAGs) composed of females displaying mounting activity. Although this technique promotes the enhancement of sexual behavior, there are cows in estrus (CE) that delay estrus expression and also cows not displaying estrus (CNDE) even in the presence of a preovulatory follicle (PF). To elucidate the physiological mechanisms of the delay in the onset of estrus or absence of estrus behavior, an observational study was undertaken in 17 Bos indicus cows treated with exogenous progesterone (CIDR) to synchronize estrus and to monitor follicular growth and its steroidogenic activity. After SAGs formation, cows were ovariectomized at 24, 48, and 72 h post-CIDR. Among ovariectomized groups there were only 9 CE which: 1) showed differences in the onset of estrus; 2) displayed distinctive follicular growth patterns; and 3) at 72 h produced the highest intrafollicular estradiol concentration, and showed a linear trend to increase expression of P450scc and P450arom. Comparison of CE vs. CNDE showed that: 1) both groups had progesterone levels indicative of cyclic activity, and a PF which grew at a similar rate and size; 2) CE showed a stronger association between time and growth; and 3) CE produced more intrafollicular estradiol and progesterone, together with the expression of higher levels of P450arom. Results suggest that pending on the pattern of growth of the PF and its steroidogenic potential to produce estradiol, the onset and expression of estrus behavior may be delayed probably until the establishment of the appropriate conditions to ensure ovulation.

  12. Faecal chemical cues in water buffalo that facilitate estrus detection.

    PubMed

    Karthikeyan, Kandasamy; Muniasamy, Samuthirapandi; SankarGanesh, Devaraj; Achiraman, Shanmugam; Ramesh Saravanakumar, Veluchamy; Archunan, Govindaraju

    2013-05-01

    Chemo-signals are among the reliable non-invasive methods for estrus detection in mammals. Water buffalo is a silent heat animal and, hence, there is search for chemo-signals which would be effective non-invasive indicators of estrus state. We analyzed the faecal chemical cues during the estrous cycle in buffalo and to find the estrus-specific faecal volatile compounds adopting bull behavior assay. The faecal samples were collected at three phases of the estrous cycle (i.e., proestrus, estrus and postestrus) and subjected to gas chromatography-mass spectrometry analyses. We found 27 volatile compounds in the faeces of buffaloes, of which 4-methyl phenol (4mp) and trans-verbenol (tv) were found only in estrus faeces. The faecal samples of estrus buffaloes and the estrus-specific compound(s) (4mp+tv) at three different concentrations were tested for behavioral responses (flehmen and mounting behavior) in the bull. The bulls exhibited repeated flehmen when exposed to a combination of the two compounds (i.e., 4mp+tv) as compared to the individual compounds or raw faecal sample collected from buffalo when in estrus (P<0.05). However, higher number of mounting behavior was recorded when bulls were exposed to 4mp followed by a combination of the two compounds (4mp+tv) and trans-verbenol (P<0.05), in that order. By contrast, less number of mounting behavior was exhibited by bulls when exposed to the control sample (i.e., Hexadecanoic acid) (P<0.05). As inferred from the bull behavior assay, the present study suggests that the two compounds, 4 methyl phenol and trans-verbenol would be reliable indicators of estrus in buffaloes.

  13. Mechanisms of nonhormonal activation of adenylate cyclase based on target analysis

    SciTech Connect

    Verkman, A.S.; Ausiello, D.A.; Jung, C.Y.; Skorecki, K.L.

    1986-08-12

    Radiation inactivation was used to examine the mechanism of activation of adenylate cyclase in the cultured renal epithelial cell line LLC-PK1 with hormonal (vasopressin) and nonhormonal (GTP, forskolin, fluoride, and chloride) activating ligands. Intact cells were frozen, irradiated at -70 degrees C (0-14 Mrad), thawed, and assayed for adenylate cyclase activity in the presence of activating ligands. The ln (adenylate cyclase activity) vs. radiation dose relation was linear (target size 162 kDa) for vasopressin- (2 microM) stimulated activity and concave downward for unstimulated (10 mM Mn/sup 2 +/), NaF- (10 mM) stimulated, and NaCl- (100 mM) stimulated activities. Addition of 2 microM vasopressin did not alter the ln activity vs. dose relation for NaF- (10 mM) stimulated activity. The dose-response relations for adenylate cyclase activation and for transition in the ln activity vs. dose curve shape were measured for vasopressin and NaF. On the basis of our model for adenylate cyclase subunit interactions reported previously (Verkman, A. S., Skorecki, K. L., and Ausiello, D. A. (1986) Am. J. Physiol. 260, C103-C123) and of new mathematical analyses, activation mechanisms for each ligand are proposed. In the unstimulated state, equilibrium between alpha beta and alpha + beta favors alpha beta; dissociated alpha binds to GTP (rate-limiting step), which then combines with the catalytic (C) subunit to form active enzyme. Vasopressin binding to receptor provides a rapid pathway for GTP binding to alpha. GTP and its analogues accelerate the rate of alpha GTP formation. Forskolin inhibits the spontaneous deactivation of activated C. Activation by fluoride may occur without alpha beta dissociation or GTP addition through activation of C by an alpha beta-F complex.

  14. Synchronicity from synchronized chaos

    DOE PAGES

    Duane, Gregory

    2015-04-01

    The synchronization of loosely-coupled chaotic oscillators, a phenomenon investigated intensively for the last two decades, may realize the philosophical concept of “synchronicity”—the commonplace notion that related events mysteriously occur at the same time. When extended to continuous media and/or large discrete arrays, and when general (non-identical) correspondences are considered between states, intermittent synchronous relationships indeed become ubiquitous. Meaningful synchronicity follows naturally if meaningful events are identified with coherent structures, defined by internal synchronization between remote degrees of freedom; a condition that has been posited as necessary for synchronizability with an external system. The important case of synchronization between mind andmore » matter is realized if mind is analogized to a computer model, synchronizing with a sporadically observed system, as in meteorological data assimilation. Evidence for the ubiquity of synchronization is reviewed along with recent proposals that: (1) synchronization of different models of the same objective process may be an expeditious route to improved computational modeling and may also describe the functioning of conscious brains; and (2) the nonlocality in quantum phenomena implied by Bell’s theorem may be explained in a variety of deterministic (hidden variable) interpretations if the quantum world resides on a generalized synchronization “manifold”.« less

  15. Synchronicity from synchronized chaos

    SciTech Connect

    Duane, Gregory

    2015-04-01

    The synchronization of loosely-coupled chaotic oscillators, a phenomenon investigated intensively for the last two decades, may realize the philosophical concept of “synchronicity”—the commonplace notion that related events mysteriously occur at the same time. When extended to continuous media and/or large discrete arrays, and when general (non-identical) correspondences are considered between states, intermittent synchronous relationships indeed become ubiquitous. Meaningful synchronicity follows naturally if meaningful events are identified with coherent structures, defined by internal synchronization between remote degrees of freedom; a condition that has been posited as necessary for synchronizability with an external system. The important case of synchronization between mind and matter is realized if mind is analogized to a computer model, synchronizing with a sporadically observed system, as in meteorological data assimilation. Evidence for the ubiquity of synchronization is reviewed along with recent proposals that: (1) synchronization of different models of the same objective process may be an expeditious route to improved computational modeling and may also describe the functioning of conscious brains; and (2) the nonlocality in quantum phenomena implied by Bell’s theorem may be explained in a variety of deterministic (hidden variable) interpretations if the quantum world resides on a generalized synchronization “manifold”.

  16. Influence of lameness on follicular growth, ovulation, reproductive hormone concentrations and estrus behavior in dairy cows

    PubMed Central

    Morris, M.J.; Kaneko, K.; Walker, S.L.; Jones, D.N.; Routly, J.E.; Smith, R.F.; Dobson, H.

    2011-01-01

    The objective of this study was to examine the effect of a chronic stressor, lameness, on reproductive parameters. Seventy cows 30–80 days post-partum were scored for lameness and follicular phases synchronized with GnRH followed seven days later by prostaglandin (PG). Fifteen Lame animals did not respond to GnRH ovarian stimulation. Milk progesterone for 5 days prior to PG was lower in the remaining Lame cows than Healthy herdmates. Fewer Lame cows ovulated (26/37 versus 17/18; P = 0.04) and the interval from PG to ovulation was shorter in Lame cows. In Subset 1 (20 animals), the LH pulse frequency was similar in ovulating animals (Lame and Healthy) but lower in Lame non-ovulators. An LH surge always preceded ovulation but lameness did not affect the interval from PG to LH surge onset or LH surge concentrations. Before the LH surge, estradiol was lower in non-ovulating cows compared to those that ovulated and estradiol concentrations were positively correlated with LH pulse frequency. In Subset 2 (45 cows), Lame ovulating cows had a less intense estrus than Healthy cows, although Lame cows began estrus and stood-to-be-mounted earlier than Healthy cows. In conclusion, we have identified several parameters to explain poor fertility in some chronically stressed animals. From 30 to 80 days post-partum, there was a graded effect that ranged from 29% Lame cows with absence of ovarian activity, whereas another 21% Lame cows failed to express estrus or ovulate a low estrogenic follicle; in 50% cows, many reproductive parameters were unaffected by lameness. PMID:21601262

  17. A new class of non-hormonal contragestational agents: pharmacodynamic-pharmacokinetic relationships.

    PubMed

    Assandri, A; Omodei-Salé, A; Galliani, G

    1982-01-01

    As part of a research program designed to find new potential antifertility agents, new non-hormonal, non-prostaglandin-like compounds belonging to the class of 2-phenyl-triazole (5,1-a) isoindoles Ia and the corresponding dehydro-isoquinolines Ib were identified in the laboratories of the Departments of Pharmacokinetics, Organic Chemsitry, and Endocrinology (Gruppo Lepetit, Milan, Italy). These new structures were shown to be effective at nontoxic doses in several animal species as post-implantation, early pregnancy termination agents. Starting from these leader compounds, studies designed to clarify simultaneously both their spectrum of activity and the structure-activity relationships were undertaken. Following this initial explorative phase, keeping in mind that an antifertility agent must be highly effective over a period of time sufficiently long to block a dynamic process such as pregnancy, selected compounds were studied in depth in order to determine the relationships between their bioavailability and their effectiveness. This manuscript reviews the multidisciplinary research which led to the selection of the 1st generation compounds that have not only the very high potencies but also the diverse kinetic characteristics to make them suitable for potential use in animals and in humans. In the development of these new contragestational agents, it was apparent early that the achievement of the biological effect would be strictly dependent upon prolonged availability. Thus, in the primary screening, the period of treatment in pregnancy (most effective time), the route (subcutaneous), and the schedule of treatment (multiple daily doses) chosen, were those least affected by kinetic and metabolic factors. Structure-activity relationships studies in 2 species with marked differences in sensitivity (rat, hamster) made it possible to ascertain the key portions of the molecules and the types of substituents that could either improve the activity or reduce the species

  18. Persistent dominant follicle alters pattern of oviductal secretory proteins from cows at estrus.

    PubMed

    Binelli, M; Hampton, J; Buhi, W C; Thatcher, W W

    1999-07-01

    The experimental objective was to compare synthesis of oviductal secretory proteins of dairy cows bearing a persistent dominant follicle (PDF) versus a fresh dominant follicle (FDF) at estrus. On Day 7 after synchronized estrus (Day 0), cows received an intravaginal progesterone device and injection of prostaglandin F2alpha (PGF2alpha). On Day 9, cows received an injection of a GnRH agonist (FDF group; n = 3) or received no injection (PDF group, n = 3). On Day 16, all cows received PGF2alpha, and progesterone devices were removed. At slaughter on Day 18 or Day 19, oviducts ipsilateral and contralateral to the dominant follicle were divided into infundibulum, ampulla, and isthmus regions. Explants from oviductal regions were cultured in minimal essential medium supplemented with [3H]leucine for 24 h. Two-dimensional fluorographs of proteins in conditioned media were analyzed by densitometry. Rate of incorporation of [3H]leucine into macromolecules was greater in the infundibulum, ampulla, and isthmus of FDF cows (p < 0.01). Overall, intensities of radiolabeled secretory protein (P) 2 and P13 were greater for FDF than for PDF. In the ampulla, P14 was more intense for FDF while P7 was more intense for PDF. Abundance of P1 in the isthmus was greater for PDF cows. Across regions, P5, P6, P8, P9, and P11 were more intense for PDF than for FDF in the ipsilateral side. In the contralateral side, P19 was more intense for PDF than for FDF, whereas P6, P8, P9, and P11 were more intense for FDF. Differences in biosynthetic activity and in secreted oviductal proteins from cows bearing a PDF may contribute to the decrease in fertility associated with a PDF.

  19. Lameness, Activity Time-Budgets, and Estrus Expression in Dairy Cattle

    PubMed Central

    Walker, S. L.; Smith, R. F.; Routly, J. E.; Jones, D. N.; Morris, M. J.; Dobson, H.

    2009-01-01

    The aim of the present study was to identify specific behavioral patterns that contribute to diminished estrus expression in lame cows. Behavioral scan and focal sampling were used to examine the effect of lameness on daily activity budgets, sexual behavior, feeding activities, and body condition score. A total of 59 milking cows (51.8 ± 1.4 d postpartum) were monitored on a commercial dairy farm for 5 d following estrus synchronization. Overall, lame cows (n = 39) spent proportionately less time elevated on their feet and more time lying down compared with nonlame cows (n = 20). This included lame cows spending less time walking or standing. Overall, the total proportion of scans in which an estrous behavior was observed was very small but tended to be smaller for lame compared with nonlame cows. Throughout a day, lame cows displayed a lower proportion of estrous behaviors in the early morning. Lameness did not affect durations of drinking, grazing, or ruminating, or how these behavioral states fluctuated throughout the day. Similarly, rumination chewing rates were the same for lame and nonlame cows, and there was no association between lameness and dominance/displacement while feeding at a feed-fence. Lame cows did, however, have a slower bite rate at pasture and had a lower body condition score. Lame cows were also nearer the rear of the herd, both as they left the field and when entering the milking parlor. In conclusion, lame cows have longer lying times and spend less time standing, walking, and expressing an estrous behavior. Lame cows also have a lower bite rate at pasture and are more likely to be of lower body condition score. PMID:19038930

  20. Non-hormonal treatment of vulvo-vaginal atrophy-related symptoms in post-menopausal women.

    PubMed

    Tersigni, C; Di Simone, N; Tempestilli, E; Cianfrini, F; Russo, R; Moruzzi, M C; Amar, I D; Fiorelli, A; Scambia, G; Villa, P

    2015-01-01

    In post-menopausal period vulvo-vaginal atrophy (VVA)-related symptoms may seriously affect women's quality of life. Hormonal replacement therapy effectively relieves these symptoms but it is not always safe or accepted, and a non-hormonal treatment is often needed instead. Over a period of 12 weeks, we tested the effect of a twice-a-week vulvo-vaginal application of a hyaluronic acid, AC collagen, isoflavones and vitamins-based cream (Perilei Pausa) on 35 women in post-menopausal period, reporting VVA-related symptoms. After 12 weeks of treatment with Perilei Pausa a significant improvement in vaginal dryness, vulvo-vaginal itching, dyspareunia (P < 0.001), dysuria (P = 0.02), nocturia (P = 0.009) and pollakiuria (P = 0.005) was reported by the women. Colposcopical score assessing the intensity of atrophic colpitis, cervico-vaginal paleness and petechiae was also reduced (P = 0.037, P = 0.016 and P = 0.032, respectively). No significant difference in terms of maturation value of cervico-vaginal epithelium was observed. In conclusion, Perilei Pausa may represent an effective and safe alternative treatment of symptomatic VVA in post-menopausal women.

  1. Selecting Female Mice in Estrus and Checking Plugs.

    PubMed

    Behringer, Richard; Gertsenstein, Marina; Nagy, Kristina Vintersten; Nagy, Andras

    2016-01-01

    The female mouse estrous cycle is divided into four phases: proestrus (development of ovarian follicles), estrus (ovulation), metestrus (formation of corpora lutea), and diestrus (beginning of follicle development for next ovulation and elimination of previous oocytes). The appearance of the epithelium of the external genitalia is used to identify the stage of the estrous cycle of a female mouse. This is usually easier to see in strains with either no or only light skin pigmentation. By examining the color, moistness, and degree of swelling of the vagina, females in estrus can readily be identified. To set up the matings, females are examined in the afternoon, and those in estrus are placed into the cages with males (one or two females in each cage with one male). Usually, 50% or more of the selected females will mate. The presence of a vaginal copulation plug next morning indicates that mating has occurred, but it does not mean that a pregnancy will result even if proven breeder fertile males were used. It is important to check vaginal plugs early in the morning because they fall out or are no longer detectable ~12 h after mating or sometimes earlier. PMID:27480722

  2. Fertility in Gyr Cows (Bos indicus) with Fixed Time Artificial Insemination and Visual Estrus Detection Using a Classification Table

    PubMed Central

    Ramírez-Iglesia, Lilido Nelson; Roman Bravo, Rafael María; Díaz de Ramirez, Adelina; Torres, Leandro J.

    2014-01-01

    The aim of this research was to compare two artificial insemination protocols (AIP): hormonal synchronization with fixed time artificial insemination (SC-FTAI) and the use of a table based on visual observation of estrus signs (VO) in order to identify cows in natural or spontaneous estrus being assigned to AI (NSE-IA). Two groups were formed: in the first group 109 cows were assigned to SC-FTAI, in which a commercial protocol is used; the second one included 108 randomly chosen cows, which were assigned to NSE-AI and in this group a modified table was used. Response variable was first service fertility rate (FSF), which was coded 1 for pregnant and 0 for empty. Predictor variables were AIP, postpartum anestrus, daily milk yield, body condition score at AI and calving number. Statistical analyses included association chi-square tests and logistic regression. Results showed an overall 41.94% FSF and a significant association was detected (P < 0.05) between FSF and daily milk yield; pregnancy rates were 42.20% and 41.67% for the SC-FTAI and NSE-IA groups, respectively (P > 0.05). The odds ratio for the effect of AIP was only 1.050, suggesting no differences in FSF between groups. The NSE-AI protocol can enhance both the technique of VO and reproductive efficiency. Further validation of the table is required. PMID:26464929

  3. Pharmacodynamic model of the rat estrus cycle in relation to endocrine disruptors.

    PubMed

    Andersen, M E; Clewell, H J; Gearhart, J; Allen, B C; Barton, H A

    1997-10-24

    Several strains of laboratory rats have a high background incidence of mammary tumors and develop a persistent, anovulatory estrus condition at about 12 mo of age. The increased tumor incidence is believed to be associated with elevated estradiol (E2) and prolactin during the period of persistent estrus. A pharmacodynamic estrus cycle (PD-EC) model for the Sprague-Dawley rats has been developed in an attempt to analyze the physiological basis of early-onset persistent estrus and to examine the potential sites of interactions in the hypothalamic-pituitary-ovarian axis for endocrine-modulating xenobiotics that accelerate the onset of persistent estrus. This initial estrus cycle model focused solely on cyclical changes in E2 and luteinizing hormone (LH). An LH surge was scheduled when a hypothetical estrus cycle-related protein (EC-RP) under transcriptional control by the E2 receptor reached a critical concentration. In the model, aging-related cumulative hypothalamic E2 exposure impaired the LH surge by reducing the rate of production of the EC-RP. The progressively decreasing intercycle resynthesis rate leads first to longer, variable-length cycles and finally to persistent estrus at about 12 mo of age. This model construct is consistent with early-onset persistent estrus related to neonatal E2 exposures, with acyclicity associated with high-dose E2 exposure in the adult, and with persistent estrus conditions associated with exposures to xenobiotic endocrine modulators that are either weak E2 antagonists or weak E2 agonists. With further development these pharmacodynamic estrus cycle models should be useful in aiding risk assessments for compounds causing mammary-tissue tumors associated with persistent estrus states.

  4. Use of a domestic Korean black goat (Capra hircus coreanae) with its chest crayon-harnessed in detecting estrus of Himalayan tahrs (Hemitragus jemlahicus)

    PubMed Central

    Yong, Hwanyul

    2014-01-01

    The reliability of a Korean black goat (Capra hircus coreanae) to detect estrus in Himalayan tahrs (Hemitragus jemlahicus) for an artificial breeding program was investigated. Estrus in six female Himalayan tahrs was synchronized using fluorogestone acetate (FGA) sponges. Thirteen days later, 200 IU of PMSG and 100 IU of hCG were injected before removing the sponges and simultaneously injecting 5 mg of PGF2α the next day. Penetration of the cervical canal and the thickness and location of red crayon marks were examined 40~43 h later. Two females treated with sponges containing 60 or 45 mg of FGA had estrogen levels of 8.7 and 11.1 pg/mL, respectively. No red marks were found on the backs of these two tahrs. The remaining females had higher levels of estradiol, and the red crayon marks were clearly shown. The cervical folds of these tahrs were readily penetrated and the insemination gun was smoothly inserted into the uterine body. In conclusion, a Korean domestic goat with its chest crayon-harnessed was successfully used to detect estrus of Himalayan tahrs. This technique might be utilized as a part of breeding programs for wild goats and avoid the need for a vasectomy of conspecific males. PMID:24690603

  5. Effect of vaccination with a multivalent modified-live viral vaccine on reproductive performance in synchronized beef heifers.

    PubMed

    Walz, Paul H; Edmondson, Misty A; Riddell, Kay P; Braden, Timothy D; Gard, Julie A; Bayne, Jenna; Joiner, Kellye S; Galik, Patricia K; Zuidhof, Sjoert; Givens, M Daniel

    2015-03-15

    Prebreeding vaccination should provide fetal and abortive protection against bovine viral diarrhea virus (BVDV) and bovine herpesvirus 1 (BoHV-1) but not impede reproduction when administered to cattle before estrus synchronization and breeding. The objective was to assess reproductive performance when naive beef heifers were vaccinated with modified-live viral (MLV) vaccine 2 days after unsynchronized estrus, and then revaccinated with MLV vaccine at 10 or 31 days before synchronized natural breeding. Sixty beef heifers naive to BVDV and BoHV-1 were randomly assigned to one of four treatment groups. Groups A and B (n = 20 per group) were vaccinated with MLV vaccine containing BVDV and BoHV-1 at 2 days after initial detected estrus, and then revaccinated 30 days later, which corresponded to 10 days (group A) or 31 days (group B) before synchronized natural breeding. Groups C and D (n = 10 per group) served as controls and were vaccinated with an inactivated vaccine that did not contain BVDV or BoHV-1 at the same time points as groups A and B, respectively. Estrous behavior was assessed using radio frequency technology. Estrus synchronization was performed, with initiation occurring at revaccination (groups A and C) or 21 days after revaccination (groups B and D). After synchronization, heifers were submitted to a bull breeding pasture for 45 days. At the end of the breeding period, heifers were assessed for pregnancy using ultrasonography. Progesterone concentrations were evaluated at estrus and 10 days after unsynchronized and synchronized estrus, at initial pregnancy check, and at the end of the study. All pregnant heifers in groups A and B and five pregnant heifers in group C were euthanized between 44 and 62 days of gestation and ovarian and conceptus tissues were assayed for BVDV and BoHV-1. Vaccination with MLV vaccine did not result in significant negative reproductive impact based on the duration of interestrus intervals, proportion of heifers

  6. Analysis of non-hormonal nutritional supplements for anabolic-androgenic steroids - results of an international study.

    PubMed

    Geyer, H; Parr, M K; Mareck, U; Reinhart, U; Schrader, Y; Schänzer, W

    2004-02-01

    Several recent studies have shown evidence of some nutritional supplements containing prohibited anabolic androgenic steroids, so-called prohormones, which were not declared on the label. Therefore, a broad-based investigation of the international nutritional supplement market was initiated to clarify the extent of this problem. From October 2000 until November 2001, 634 non-hormonal nutritional supplements were purchased in 13 countries from 215 different suppliers. Most supplements were bought in shops in the respective countries (578 samples = 91.2 %) and on the internet (52 samples = 8.2 %). 289 supplements were from prohormone-selling companies and 345 supplements came from companies which do not offer prohormones. After isolation from the supplement matrix 11 different anabolic androgenic steroids, mainly prohormones of testosterone and nandrolone, were analysed by gas-chromatography/mass spectrometry. Out of the 634 samples analysed 94 (14.8 %) contained anabolic androgenic steroids not declared on the label ("positive supplements"). We could not obtain reliable data for 66 samples (10.4 %) due to matrix effects. In relation to the total number of products purchased per country, most of the positive supplements were bought in the Netherlands (25.8 %), in Austria (22.7 %), in the UK (18.8 %) and the USA (18.8 %). According to the label, all positive supplements were from companies located in only five countries: the USA, the Netherlands, the UK, Italy and Germany. 21.1 % of the nutritional supplements from prohormone-selling companies contained anabolic androgenic steroids, whereas 9.6 % of the supplements from companies not selling prohormones were positive. The positive supplements showed anabolic androgenic steroid concentrations of 0.01 micro g/g up to 190 micro g/g. The administration of supplements containing nandrolone prohormones adding up to a total uptake of more than 1 micro g resulted in positive doping results for norandrosterone for several

  7. Application of electronic estrus detection technologies to reproductive management of cattle.

    PubMed

    Rorie, R W; Bilby, T R; Lester, T D

    2002-01-01

    Artificial insemination and embryo transfer programs are dependent on efficient and accurate detection of estrus. Visual observation is accurate at detecting animals in estrus, but efficiency ranges from approximately 50 to 70%. Electronic technologies have been developed in attempts to improve estrus detection efficiency. Commercially available electronic devices for estrus detection are based on changes in physical activity (pedometers), changes in electrical resistance of reproductive tract secretions (intravaginal resistance probes) or mounting activity (mount detectors). All of the commercially available electronic estrus detection devices can improve the efficiency of estrus detection in cattle. Pedometers are most applicable to lactating dairy cattle and have greater accuracy and efficiency when combined with visual observation. Intravaginal resistance measurement is perhaps the least practical method of estrus detection because of labor and animal handling requirements. Individual resistance measurement may have practical application for confirming other inconclusive signs of estrus. Mount monitors have the broadest application to beef and dairy cattle. HeatWatch, the only real-time radiotelometric system available, requires the least labor and animal handling and provides data on the time and duration of each mount. The less expensive stand-alone mount monitors also provide the necessary information for optimum timing of insemination and embryo transfer, but are more labor intensive. PMID:11775966

  8. Spectral pattern of urinary water as a biomarker of estrus in the giant panda.

    PubMed

    Kinoshita, Kodzue; Miyazaki, Mari; Morita, Hiroyuki; Vassileva, Maria; Tang, Chunxiang; Li, Desheng; Ishikawa, Osamu; Kusunoki, Hiroshi; Tsenkova, Roumiana

    2012-01-01

    Near infrared spectroscopy (NIRS) has been successfully used for non-invasive diagnosis of diseases and abnormalities where water spectral patterns are found to play an important role. The present study investigates water absorbance patterns indicative of estrus in the female giant panda. NIR spectra of urine samples were acquired from the same animal on a daily basis over three consecutive putative estrus periods. Characteristic water absorbance patterns based on 12 specific water absorbance bands were discovered, which displayed high urine spectral variation, suggesting that hydrogen-bonded water structures increase with estrus. Regression analysis of urine spectra and spectra of estrone-3-glucuronide standard concentrations at these water bands showed high correlation with estrogen levels. Cluster analysis of urine spectra grouped together estrus samples from different years. These results open a new avenue for using water structure as a molecular mirror for fast estrus detection. PMID:23181188

  9. Spectral pattern of urinary water as a biomarker of estrus in the giant panda

    NASA Astrophysics Data System (ADS)

    Kinoshita, Kodzue; Miyazaki, Mari; Morita, Hiroyuki; Vassileva, Maria; Tang, Chunxiang; Li, Desheng; Ishikawa, Osamu; Kusunoki, Hiroshi; Tsenkova, Roumiana

    2012-11-01

    Near infrared spectroscopy (NIRS) has been successfully used for non-invasive diagnosis of diseases and abnormalities where water spectral patterns are found to play an important role. The present study investigates water absorbance patterns indicative of estrus in the female giant panda. NIR spectra of urine samples were acquired from the same animal on a daily basis over three consecutive putative estrus periods. Characteristic water absorbance patterns based on 12 specific water absorbance bands were discovered, which displayed high urine spectral variation, suggesting that hydrogen-bonded water structures increase with estrus. Regression analysis of urine spectra and spectra of estrone-3-glucuronide standard concentrations at these water bands showed high correlation with estrogen levels. Cluster analysis of urine spectra grouped together estrus samples from different years. These results open a new avenue for using water structure as a molecular mirror for fast estrus detection.

  10. Comparison of fertility, regular returns-to-estrus, and calving interval between Ovsynch and CO-synch + CIDR protocols in dairy cows.

    PubMed

    Azevedo, C; Maia, I; Canada, N; Simões, J

    2014-10-01

    The main aims of the present study were to compare the pregnancy rate (PR), regular returns-to-estrus, and calving interval of a CO-Synch + controlled internal drug release (CIDR) device, commonly used to synchronize ovulations in beef cows, with the classical Ovsynch protocol in high-producing dairy cows. Holstein-Friesian cows (n = 128) from six commercial dairy herds, ≥40 days postpartum and not previously inseminated, were randomly assigned to one of two treatments. Cows submitted to Ovsynch protocol (group OS as control group; n = 66) received 10 μg of a GnRH analogue 7 days before and 48 hours after 25 mg PGF2α, followed by artificial insemination (AI) 16 hours after the second GnRH administration. Cows submitted to CO-Synch + CIDR (1.38 g of progesterone) inserted for 7 days beginning at the first GnRH administration (group CoS + CD; n = 62) had the second administration of GnRH concurrent with AI, 64 hours after CIDR removal/PGF2α administration. Nonpregnant cows with return-to-estrus between 18 and 24 days after first AI were reinseminated (second AI). Logistic regressions were used to analyze PR and returns-to-estrus. No effect of group or herd was observed in PR at first timed AI. However, the sum of cows pregnant at first AI and nonpregnant cows with regular returns-to-estrus and the total PR (first + second AI) were influenced by group treatment. Overall, cows of group CoS + CD (total PR = 56.5%) were 2.1 times more likely to became pregnant after AI and until first regular returns-to-estrus than cows of group OS. The calving interval was lower in group CoS + CD (425.9 ± 78.8 days; ±SD) than in group OS (475.3 ± 83.7 days). The CO-Synch + CIDR protocol was reliable to use in dairy herds and provided reproductive advantages when compared with Ovsynch protocol.

  11. Detection of estrus in Indian blackbuck: behavioural, hormonal and urinary volatiles evaluation.

    PubMed

    Archunan, Govindaraju; Rajagopal, Thangavel

    2013-01-15

    The determination of the reproductive status is one of the most important factors for effective wild life conservation and management, and effective use of assisted reproductive techniques like artificial insemination, in vitro fertilization/embryo transfer depends on the knowledge of the basic reproductive physiology. In this context the reproductive status of female blackbucks (Antelope cervicapra L.) was assessed by behaviour and determination, sex steroid hormones in faeces and urinary volatile compounds. The male and female blackbucks exhibited as many as 31 different reproductive/courtship behaviour patterns. Particularly, the males showed a more extensive repertoire: i.e. 23 behavioural patterns by territorial males, 11 by bachelor males and 4 by females. The behaviours such as, mounting, Flehmen, clockwise and anticlockwise movements were significantly higher in male blackbuck when exposed to estrus. By contrast, such courtship behaviours were completely absent in male when exposed to diestrus. It clearly indicates that, the estrus female produces specific chemical cues (pheromone) through urine, which would involve in attracting the conspecifics. In addition, the average faecal oestrogen concentration was significantly higher (p<0.05) during the estrus faecal than the proestrus and diestrus periods. In contrast, the faecal progesterone concentration was significantly higher (p<0.05) during the diestrus faecal sample than that of proestrus and estrus faecal sample. Twenty-eight volatiles are identified, across the three reproductive phases (i.e. proestrus, estrus and diestrus) of sexually mature and prepubertal females. Amongst, the compounds 2-methyl-3-butyn-2-ol, 3,7-dimethylnonane, 3-phenyl-2-propen-1-ol and 2-hydroxybenzoic acid occurred only during estrus which may be considered as marker for detection of estrus which would ultimately help for artificial insemination in captive condition. The findings of the present study suggest that the non

  12. Behavioral effects of interleukin-1 beta: modulation by gender, estrus cycle, and progesterone.

    PubMed

    Avitsur, R; Donchin, O; Barak, O; Cohen, E; Yirmiya, R

    1995-09-01

    Endogenous release or exogenous administration of the cytokine Interleukin-1 (IL-1) produces several behavioral alterations, including suppression of locomotion and exploration. Because there are bidirectional interactions between IL-1 and the hypothalamic-pituitary-gonadal axis, we investigated possible differences between males and females in various phases of the estrus cycle in the behavioral effects of IL-1. In addition, we assessed the role of progesterone in mediating estrus cycle-dependent differences in these effects. Female rats in either the estrus or the non-estrus phase of their cycle and male rats were injected with either IL-1 beta (2 or 5 micrograms/kg) or saline. Activity in the open field test was measured 2 h later by counting the number of line crossings and rearings. In saline-injected rats, nonestrus females performed less line crossings than estrus females. IL-1 produced a significant dose-dependent reduction of line crossing in males and estrus females. In contrast, in nonestrus females the lower dose of IL-1 had no effect, and the effect of the higher dose was significantly smaller in nonestrus than in estrus females. The higher dose of IL-1 suppressed rearing in all three groups, but the effect of the lower dose on the number of rearings was significant only in estrus females. In a second experiment, ovariectomized females were injected with either progesterone (2 mg/rat) or oil, followed 2 h later by an injection of either IL-1 beta (2 micrograms/kg) or saline. Activity was measured continuously by a biotelemetric system. IL-1 reduced activity in progesterone-treated ovariectomized females but not in oil-injected controls. These findings suggest that changes in progesterone secretion along the estrus cycle modulate the behavioral responsiveness to IL-1 in female rats.

  13. Litter loss triggers estrus in a nonsocial seasonal breeder

    PubMed Central

    Steyaert, Sam MJG; Swenson, Jon E; Zedrosser, Andreas

    2014-01-01

    Sexually selected infanticide (SSI) is often presumed to be rare among seasonal breeders, because it would require a near immediate return to estrus after the loss of an entire litter during the mating season. We evaluated changes in reproductive strategies and the reproductive fate of females that experienced litter loss during the mating season in a seasonal breeder with strong evidence for SSI, the brown bear. First, we used a long-term demographic dataset (1986–2011) to document that a large majority of females (>91%) that lose their entire litter during the mating season in fact do enter estrus, mate, and give birth during the subsequent birthing season. Second, we used high-resolution movement data (2005–2011) to evaluate how females changed reproductive strategies after losing their entire litter during the mating season. We hypothesized that females would shift from the sedentary lifestyle typical for females with cubs-of-the-year to a roam-to-mate behavior typical for receptive females in no more than a few (∼3) days after litter loss. We found that females with cubs-of-the-year moved at about 1/3 of the rate and in a less bimodal diurnal pattern than receptive females during the mating season. The probability of litter loss was positively related with movement rate, suggesting that being elusive and sedentary is a strategy to enhance cub survival rather than a relic of cub mobility itself. The movement patterns of receptive females and females after litter loss were indistinguishable within 1–2 days after the litter loss, and we illustrate that SSI can significantly reduce the female interbirth interval (50–85%). Our results suggest that SSI can also be advantageous for males in seasonally breeding mammals. We propose that infanticide as a male reproductive strategy is more prevalent among mammals with reproductive seasonality than observed or reported. PMID:24558586

  14. Synchronous demodulator

    NASA Technical Reports Server (NTRS)

    Sutton, John F. (Inventor)

    1991-01-01

    A synchronous demodulator includes a switch which is operated in synchronism with an incoming periodic signal and both divides and applies that signal to two signal channels. The two channels each include a network for computing and holding, for a predetermined length of time, the average signal value on that channel and applies those valves, in the form of two other signals, to the inputs of a differential amplifier. The networks may be R-C networks. The output of the differential amplifier may or may not form the output of the synchronous detector and may or may not be filtered. The output will not include a periodic signal due to the presence of a dc offset. Additionally, the output will not contain any substantial ripple due to periodic components in the input signal. In a somewhat more complex version, containing twice the structural components of the above synchronous demodulator with a more complex switching mechanism, essentially all ripple due to periodic components in the input signal are eliminated.

  15. Synchronizing Fireflies

    ERIC Educational Resources Information Center

    Zhou, Ying; Gall, Walter; Nabb, Karen Mayumi

    2006-01-01

    "Imagine a tenth of a mile of river front with an unbroken line of trees with fireflies on ever leaf flashing in synchronism. ... Then, if one's imagination is sufficiently vivid, he may form some conception of this amazing spectacle." So wrote the naturalist Hugh Smith. In this article we consider how one might model mathematically the…

  16. Saliva ferning, an unorthodox estrus detection method in water buffaloes (Bubalus bubalis).

    PubMed

    Ravinder, R; Kaipa, Onnureddy; Baddela, Vijay Simha; Singhal Sinha, Eshu; Singh, Prashant; Nayan, Varij; Velagala, Chandra Sekhar Naidu; Baithalu, Rubina Kumari; Onteru, Suneel Kumar; Singh, Dheer

    2016-09-15

    Estrus detection is a major problem in buffalo husbandry because of inconsistent expression of estrous signs at different seasons, and a high prevalence of the silent heat and postpartum anestrus in this species. Around 50% of the estrus events in buffaloes are currently undetected in the field conditions, resulting in a huge economic loss. Although the cervicovaginal fluid fern patterns confirm the estrus for a breeding decision, the fluid discharge is absent during the silent-heat condition. Therefore, the present study focused on the crystallization patterns of the saliva as an alternative method for estrus detection in buffaloes. Saliva is a body fluid available regularly, and its ferning ability before ovulation was established in women. In this study, eight female nonpregnant Murrah buffaloes (Bubalus bubalis) were considered during two experimental periods of 3 months each. One period was in summer with five animals, and another period was in rainy season with three animals. Estrus was determined by the estrus symptoms, ovarian ultrasonography, and salivary estradiol (E2) to progesterone (P4) ratio. A total of 450 saliva samples were collected from these animals on the daily basis. The salivary smear was prepared with 20 μL of the cell-free saliva on a clean glass slide, and its microscopic images were captured at a magnification of × 200. The images were used for fractal analysis as the salivary crystallization or fern patterns follow the fractal geometry. Saliva at estrus showed a typical symmetrical fern-like crystallization patterns with significantly (P < 0.05) lower fractal dimension values. Salivary estradiol levels and E2/P4 ratio were significantly (P < 0.05) higher at the estrus stage than those at the diestrus stage. An average period of an estrous cycle was 21.7 ± 2.7 days (n = 18 estrous cycles) in buffaloes on the basis of distinct salivary crystallization patterns. The proportion of estrus detection by the salivary fern patterns

  17. Saliva ferning, an unorthodox estrus detection method in water buffaloes (Bubalus bubalis).

    PubMed

    Ravinder, R; Kaipa, Onnureddy; Baddela, Vijay Simha; Singhal Sinha, Eshu; Singh, Prashant; Nayan, Varij; Velagala, Chandra Sekhar Naidu; Baithalu, Rubina Kumari; Onteru, Suneel Kumar; Singh, Dheer

    2016-09-15

    Estrus detection is a major problem in buffalo husbandry because of inconsistent expression of estrous signs at different seasons, and a high prevalence of the silent heat and postpartum anestrus in this species. Around 50% of the estrus events in buffaloes are currently undetected in the field conditions, resulting in a huge economic loss. Although the cervicovaginal fluid fern patterns confirm the estrus for a breeding decision, the fluid discharge is absent during the silent-heat condition. Therefore, the present study focused on the crystallization patterns of the saliva as an alternative method for estrus detection in buffaloes. Saliva is a body fluid available regularly, and its ferning ability before ovulation was established in women. In this study, eight female nonpregnant Murrah buffaloes (Bubalus bubalis) were considered during two experimental periods of 3 months each. One period was in summer with five animals, and another period was in rainy season with three animals. Estrus was determined by the estrus symptoms, ovarian ultrasonography, and salivary estradiol (E2) to progesterone (P4) ratio. A total of 450 saliva samples were collected from these animals on the daily basis. The salivary smear was prepared with 20 μL of the cell-free saliva on a clean glass slide, and its microscopic images were captured at a magnification of × 200. The images were used for fractal analysis as the salivary crystallization or fern patterns follow the fractal geometry. Saliva at estrus showed a typical symmetrical fern-like crystallization patterns with significantly (P < 0.05) lower fractal dimension values. Salivary estradiol levels and E2/P4 ratio were significantly (P < 0.05) higher at the estrus stage than those at the diestrus stage. An average period of an estrous cycle was 21.7 ± 2.7 days (n = 18 estrous cycles) in buffaloes on the basis of distinct salivary crystallization patterns. The proportion of estrus detection by the salivary fern patterns

  18. Estrous synchronization in captive collared peccaries (Pecari tajacu) using a prostaglandin F2α analog.

    PubMed

    Maia, Keilla Moreira; Peixoto, Gislayne Christianne Xavier; Campos, Lívia Batista; Silva, Andréia Maria da; Castelo, Thibério de Souza; Ricarte, Aracely Rafaelle Fernandes; Silva, Alexandre Rodrigues

    2014-12-01

    We verify the efficiency of a protocol for estrus synchronization in captive female collared peccaries (Pecaricari tajacu) using the prostaglandin analog D-cloprostenol. Five adult female collared peccaries received an intramuscular administration of 60 µg D-cloprostenol, which procedure was repeated after a 9-day interval. For 10 days after second the D-cloprostenol administration, females were monitored for changes in external genitalia, ovarian ultrasonography, vaginal cytology and reproductive hormonal dosage. As a result, four females synchronized their estrous at 9.5 ± 0.5 days after the second administration of the prostaglandin analog. Such females showed external signs of estrus, including vulvar opening, hyperemic vaginal mucosa, and vaginal mucus, concomitant with an increase in the proportion of superficial cells (52.2 ± 9.9%) verified through vaginal cytology. An estrogen peak of 22.7 ± 3.4 pg/ml was detected by hormonal dosage, and the presence of anechoic follicles measuring 0.29 ± 0.05 × 0.32 ± 0.07 mm were detected in the ovary by ultrasonography. Given these findings, we suggest that D-cloprostenol may be effective for use in estrus synchronization in collared peccaries.

  19. Ovarian reaction and estrus manifestation in delayed puberty gilts after treatment with equine chorionic gonadotropin

    PubMed Central

    2012-01-01

    Background Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement gilts at large breeding farm units in Vojvodina. It is imperative to determine if these gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty gilts following injection with eCG. Methods Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic) gilts, and 120 sexually mature (cyclic) gilts were injected with a single injection of 400 IU eCG + 200 IU human chorionic gonadotropin (hCG) or with 1000 IU eCG (cyclic gilts), at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty gilts (estrus not detected until 8 month of age, av. 258 days) were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of gilts (n = 60) was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10th. Results Ovulations were induced in 90% of acyclic (sexually immature) and, on average, 93.3% of cyclic (sexually mature) gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature) gilts and in 95% (19/20) of the cyclic (sexually mature) gilts, treated with eCG on day 17 after

  20. The detection of estrus in cattle raised under tropical conditions: what we know and what we need to know.

    PubMed

    Galina, Carlos S; Orihuela, Agustín

    2007-06-01

    Lack of accuracy in estrus detection in cattle is a major constraint affecting the implementation of techniques such as artificial insemination (AI) and embryo transfer (ET). For this reason clinicians have opted to pharmacologically manipulate the estrus cycle. The advantages and shortcomings of using this approach to improve the implementation of AI and ET are discussed in this review. Moreover, in order to highlight the reasons why estrus detection is difficult in cows kept at grazing in the tropics, this review underlines social and behavioral traits hindering the capacity of the casual observer to accurately identify cows in estrus. PMID:17482614

  1. Estrus detection using radiotelemetry or visual observation and tail painting for dairy cows on pasture.

    PubMed

    Xu, Z Z; McKnight, D J; Vishwanath, R; Pitt, C J; Burton, L J

    1998-11-01

    The efficiency and accuracy of estrus detection using HeatWatch (DDx Inc., Denver, CO) or visual observation were compared in an autumn-calving Friesian herd (n = 48 per group) and a spring-calving Jersey herd (n = 50 per group) grazing on pasture. Cows in the group monitored by the HeatWatch system were fitted with a pressure-sensitive transmitter that signaled mounting activities associated with estrus. Visual observation was carried out for about 20 min before the morning and afternoon milkings and was aided by a strip of paint applied over the tailhead. Ovarian cyclicity was monitored with progesterone concentrations in milk samples collected twice a week. The efficiency and accuracy of estrus detection were, respectively, 98.4 and 97.6% for visual observation and 91.7 and 100% for HeatWatch detection. Autumn-calving herds differed from spring-calving herds in duration of estrus (9.7 vs. 7.3 h), number of mounts (13.6 vs. 8.5), total duration of mounts (36.8 vs. 19.9 s), and mean duration of a mount (2.6 vs. 2.3 s). There was no significant variation in the distribution of the time of onset of estrus or mounting activities at different hours of the day. Conception rate was similar for AI after estrus detection with HeatWatch (65.8%) or after visual observation (65.0%). The highest conception rate was obtained when AI was carried out between 12 and 18 h after the first mount. Both the HeatWatch system and visual observation plus tail painting can be used for estrus detection of dairy cows on pasture.

  2. Uterine glycogen metabolism in mink during estrus, embryonic diapause and pregnancy.

    PubMed

    Dean, Matthew; Hunt, Jason; McDougall, Lisa; Rose, Jack

    2014-01-01

    We have determined uterine glycogen content, metabolizing enzyme expression and activity in the mink, a species that exhibits obligatory embryonic diapause, resulting in delayed implantation. Gross uterine glycogen concentrations were highest in estrus, decreased 50% by diapause and 90% in pregnancy (P ≤ 0.05). Endometrial glycogen deposits, which localized primarily to glandular and luminal epithelia, decreased 99% between estrus and diapause (P ≤ 0.05) and were nearly undetectable in pregnancy. Glycogen synthase and phosphorylase proteins were most abundant in the glandular epithelia. Glycogen phosphorylase activity (total) in uterine homogenates was higher during estrus and diapause, than pregnancy. While glycogen phosphorylase protein was detected during estrus and diapause, glycogen synthase was almost undetectable after estrus, which probably contributed to a higher glycogenolysis/glycogenesis ratio during diapause. Uterine glucose-6-phosphatase 3 gene expression was greater during diapause, when compared to estrus (P ≤ 0.05) and supports the hypothesis that glucose-6-phosphate resulting from phosphorylase activity was dephosphorylated in preparation for export into the uterine lumen. The relatively high amount of hexokinase-1 protein detected in the luminal epithelia during estrus and diapause may have contributed to glucose trapping after endometrial glycogen reserves were depleted. Collectively, our findings suggest to us that endometrial glycogen reserves may be an important source of energy, supporting uterine and conceptus metabolism up to the diapausing blastocyst stage. As a result, the size of uterine glycogen reserves accumulated prior to mating may in part, determine the number of embryos that survive to the blastocyst stage, and ultimately litter size. PMID:25225159

  3. Short communication: Comparison of estrus characteristics in Holstein heifers by 2 activity monitoring systems.

    PubMed

    Silper, B F; Madureira, A M L; Kaur, M; Burnett, T A; Cerri, R L A

    2015-05-01

    Two activity monitoring systems-Heatime (SCR Engineers Ltd., Netanya, Israel) and IceTag (IceRobotics Ltd., Edinburgh, UK)-were compared on their ability to detect and quantify estrus expression. Holstein heifers (n=57) were fitted with Heatime (HT) and IceTag (IT) sensors from 12 mo of age until confirmation of pregnancy. Upon detection of high activity by HT, ovaries were scanned by ultrasound, a blood sample was collected for analysis of plasma estradiol, and signs of estrus (clear vaginal mucus, uterine muscle tone, visual mounting activity, standing to be mounted, or rump showing signs of repeated acceptance of mounts) were recorded. Because only estrus episodes detected by HT (n=111) were further evaluated, only the positive predictive value was measured. Heifers were housed in groups of 24 in a freestall pen. Data were analyzed using Proc CORR and GLM of SAS (SAS Institute Inc., Cary, NC). The positive predictive value was 84.7% (94/111) for HT and 98.7% (74/75) for IT. Estrus duration was recorded by HT as 14.3±4.1h [mean ± standard deviation (SD)] and by IT as 15.0±4.0h; duration measurements were correlated (r=0.60). The mean duration difference was 0.74±3.52h. Recordings of onset and end of estrus by IT were 3.5±4.3h and 2.9±4.9h earlier than those by HT. The overlap in duration was 9h. Measurements of estrus intensity were correlated (r=0.63). Peak activity was 77.3±19.5 index value (approximately 7.7 SD from basal activity) on HT. The relative increase in activity measured by IT was 360±170% baseline value. Measurements of intensity and duration from HT were correlated (r=0.64) but those from IT were not (r=0.13). Plasma estradiol concentration (11.2±4.6pg/mL) was not correlated with preovulatory follicle diameter or with duration or intensity of estrus. Diameter of preovulatory follicle (15.7±2.6mm) had no correlation with duration of estrus and was only weakly correlated with intensity measured by either system. Baseline steps/hour was

  4. Short communication: Comparison of estrus characteristics in Holstein heifers by 2 activity monitoring systems.

    PubMed

    Silper, B F; Madureira, A M L; Kaur, M; Burnett, T A; Cerri, R L A

    2015-05-01

    Two activity monitoring systems-Heatime (SCR Engineers Ltd., Netanya, Israel) and IceTag (IceRobotics Ltd., Edinburgh, UK)-were compared on their ability to detect and quantify estrus expression. Holstein heifers (n=57) were fitted with Heatime (HT) and IceTag (IT) sensors from 12 mo of age until confirmation of pregnancy. Upon detection of high activity by HT, ovaries were scanned by ultrasound, a blood sample was collected for analysis of plasma estradiol, and signs of estrus (clear vaginal mucus, uterine muscle tone, visual mounting activity, standing to be mounted, or rump showing signs of repeated acceptance of mounts) were recorded. Because only estrus episodes detected by HT (n=111) were further evaluated, only the positive predictive value was measured. Heifers were housed in groups of 24 in a freestall pen. Data were analyzed using Proc CORR and GLM of SAS (SAS Institute Inc., Cary, NC). The positive predictive value was 84.7% (94/111) for HT and 98.7% (74/75) for IT. Estrus duration was recorded by HT as 14.3±4.1h [mean ± standard deviation (SD)] and by IT as 15.0±4.0h; duration measurements were correlated (r=0.60). The mean duration difference was 0.74±3.52h. Recordings of onset and end of estrus by IT were 3.5±4.3h and 2.9±4.9h earlier than those by HT. The overlap in duration was 9h. Measurements of estrus intensity were correlated (r=0.63). Peak activity was 77.3±19.5 index value (approximately 7.7 SD from basal activity) on HT. The relative increase in activity measured by IT was 360±170% baseline value. Measurements of intensity and duration from HT were correlated (r=0.64) but those from IT were not (r=0.13). Plasma estradiol concentration (11.2±4.6pg/mL) was not correlated with preovulatory follicle diameter or with duration or intensity of estrus. Diameter of preovulatory follicle (15.7±2.6mm) had no correlation with duration of estrus and was only weakly correlated with intensity measured by either system. Baseline steps/hour was

  5. Control of estrus and ovulation: Fertility to timed insemination of gilts and sows.

    PubMed

    De Rensis, F; Kirkwood, R N

    2016-10-01

    It is possible to control follicular development in gilts and sows with the use of hormones including the progestogen altrenogest, GnRH, eCG, hCG, and porcine luteinizing hormone (pLH). These hormones can be used to develop protocols for control of estrus with artificial insemination (AI) timed to estrus detection (timed artificial insemination; TAI) or to control estrus and ovulation with insemination at a fixed time without the requirement of estrus detection (fixed-timed artificial insemination; FTAI). In cyclic gilts, double TAI after protocols based on altrenogest and eCG plus hCG administration can achieve a 70% of farrowing rate. Valuable results can be obtained in weaned sows by the utilization of protocols based on eCG administration at weaning and then GnRH or pLH at estrus onset followed by single or double TAI. In cyclic gilts, single or double FTAI regardless of estrus expression can be applied after protocols based on altrenogest administration followed by eCG and then GnRH, hCG, or pLH some hours later; farrowing rates are similar to control animals inseminated at estrus detection. With sows, a protocol based on eCG administration at weaning and hCG, GnRH, or pLH some hours later followed by single or double FTAI can give fertility rates comparable to control animal inseminated at estrus. Most recently, injection or vaginal deposition of GnRH 96 hours after weaning followed by a single FTAI 24 to 30 hours later is resulting in reproductive performance not different to animals subject to multiple inseminations after natural estrus. It is possible to apply FTAI in lactating sows. The protocols are based on eCG during lactation followed by hCG and FTAI. These protocols will induce ovulation during lactation, but pregnancy rates are reduced. However, in the future, a better knowledge on the effect of hormone administration on follicular dynamics during lactation may allow the development of more effective protocols. PMID:27287469

  6. A structural study of the bovine vaginal fluid at estrus.

    PubMed

    Rutllant, J; López-Gatius, F; Camón, J; López-Béjar, M; López-Plana, C

    1999-01-01

    The present study describes the structural components of the bovine vaginal fluid at estrus by scanning electron microscopy (SEM) following critical point- and freeze-drying preparation procedures. Confocal scanning laser microscopy (CLSM) was also used to evaluate the structural integrity of samples, and a control sample was assessed by adding sperm to the vaginal fluid. Samples were collected from 10 cows at the time of artificial insemination, prepared for SEM by using critical point- and freeze-drying procedures, gold coated, and observed by SEM. Mesh size and filament thickness were measured with an image analyzer. Of the 10 samples processed, 4 were considered altered following critical point drying. Compaction and lack of filaments were observed in these samples. A small area of one sample showed a honey comb-like structure when freeze drying was used. Nonoriented filaments with different thicknesses and with a network-like structure were observed throughout the remainder of the samples. Filaments throughout all samples were also observed by CSLM. After critical point drying, the mesh area ranged from 0.8 to 101.4 microns 2; the minor axis from 0.7 to 10.8 microns; and filament thickness from 40 to 442 nm. Using freeze drying, the mesh area ranged from 0.9 to 493.8 microns 2; the minor axis from 0.7 to 27.5 microns; and filament thickness from 40 to 800 nm. When samples were freeze dried, mesh values were similar to the interstrand channels observed by CSLM. In sperm-vaginal fluid samples, following critical point- or freeze-drying procedures, spermatozoa were oriented randomly in the vaginal fluid and did not seem to alter filamentous structure. Our data suggest that the freeze-drying procedure better preserves the true structural dimensions of the vaginal fluid. Furthermore, the filamentous structure of the vaginal fluid does not appear to impede sperm transport. PMID:10390865

  7. Factors affecting expression of estrus measured by activity monitors and conception risk of lactating dairy cows.

    PubMed

    Madureira, A M L; Silper, B F; Burnett, T A; Polsky, L; Cruppe, L H; Veira, D M; Vasconcelos, J L M; Cerri, R L A

    2015-10-01

    The objective of this study was to determine risk-factors affecting increase in physical activity during estrus and pregnancy per artificial insemination (P/AI) in lactating dairy cows. Cows were monitored continuously by 2 automated activity monitors [a collar-mounted accelerometer (HT; Heatime, SCR Engineers, Netanya, Israel) and a leg-mounted pedometer (BO; Boumatic Heat-seeker-TX, Boumatic Dairy Equipment, Madison, WI)]. When an increase in activity was detected, body condition score (BCS) and blood samples were collected, ovaries were scanned by ultrasonography, and, if the cow was eligible for breeding, artificial insemination was performed. Milk production and health-related data were recorded throughout the experimental period. Pregnancy diagnosis was performed at 42 ± 7 d of gestation. Data were analyzed using Pearson correlation, ANOVA, and logistic regression. A total of 1,099 true events of estrus from 318 lactating Holstein cows were recorded, averaging 3.46 ± 1.1 events per cow. Positive predictive value for estrus episodes detected by the HT and BO systems were 89.6 and 85.5%, respectively. Mean peak activity at estrus (PA) recorded by the HT system was 71.6 ± 20.7 index-value, and 334.3 ± 155.7% relative increase by the BO system. Compared with primiparous, multiparous cows expressed estrus with lower PA (69.3 ± 0.8 vs. 75.9 ± 1.1 index for HT; 323.9 ± 6.0 vs. 354.8 ± 8.48% for BO) and shorter duration (DU; 10.7 ± 0.2 vs. 12.0 ± 0.3 h); DU was measured by HT only. Lower BCS was associated with decreased PA measured by both systems, estrus DU, and P/AI. Peak activity was weakly correlated with milk production on the day of artificial insemination (r = -0.20); however, when categorized into quartiles, the highest-yield cows had lower PA and DU. Follicle diameter was not correlated with PA or DU, but cows with greater concentrations of estradiol had higher PA. Cows with greater PA in both systems had greater P/AI than those with lower PA (36

  8. Factors affecting expression of estrus measured by activity monitors and conception risk of lactating dairy cows.

    PubMed

    Madureira, A M L; Silper, B F; Burnett, T A; Polsky, L; Cruppe, L H; Veira, D M; Vasconcelos, J L M; Cerri, R L A

    2015-10-01

    The objective of this study was to determine risk-factors affecting increase in physical activity during estrus and pregnancy per artificial insemination (P/AI) in lactating dairy cows. Cows were monitored continuously by 2 automated activity monitors [a collar-mounted accelerometer (HT; Heatime, SCR Engineers, Netanya, Israel) and a leg-mounted pedometer (BO; Boumatic Heat-seeker-TX, Boumatic Dairy Equipment, Madison, WI)]. When an increase in activity was detected, body condition score (BCS) and blood samples were collected, ovaries were scanned by ultrasonography, and, if the cow was eligible for breeding, artificial insemination was performed. Milk production and health-related data were recorded throughout the experimental period. Pregnancy diagnosis was performed at 42 ± 7 d of gestation. Data were analyzed using Pearson correlation, ANOVA, and logistic regression. A total of 1,099 true events of estrus from 318 lactating Holstein cows were recorded, averaging 3.46 ± 1.1 events per cow. Positive predictive value for estrus episodes detected by the HT and BO systems were 89.6 and 85.5%, respectively. Mean peak activity at estrus (PA) recorded by the HT system was 71.6 ± 20.7 index-value, and 334.3 ± 155.7% relative increase by the BO system. Compared with primiparous, multiparous cows expressed estrus with lower PA (69.3 ± 0.8 vs. 75.9 ± 1.1 index for HT; 323.9 ± 6.0 vs. 354.8 ± 8.48% for BO) and shorter duration (DU; 10.7 ± 0.2 vs. 12.0 ± 0.3 h); DU was measured by HT only. Lower BCS was associated with decreased PA measured by both systems, estrus DU, and P/AI. Peak activity was weakly correlated with milk production on the day of artificial insemination (r = -0.20); however, when categorized into quartiles, the highest-yield cows had lower PA and DU. Follicle diameter was not correlated with PA or DU, but cows with greater concentrations of estradiol had higher PA. Cows with greater PA in both systems had greater P/AI than those with lower PA (36

  9. Autoclaved, previously used intravaginal progesterone devices induces estrus and ovulation in anestrous Toggenburg goats.

    PubMed

    Souza, J M G; Torres, C A A; Maia, A L R S; Brandão, F Z; Bruschi, J H; Viana, J H M; E Oba; Fonseca, J F

    2011-11-01

    Intravaginal progesterone devices are used worldwide for estrus induction in goats. Reused devices are able to induce estrus; however, this can be a health risk within a flock. The objective was to compare new and previously used (and autoclaved) progesterone-releasing intravaginal devices for induction of estrus and ovulation in seasonally anestrous Toggenburg goats. Anestrous goats (n=42) received new intravaginal devices containing 0.3g progesterone (CONTROL), or similar devices previously used for either 6 (USED6) or 12d (USED12) and subsequently autoclaved. All goats received 5mg dinoprost at device insertion and 200 IU eCG 5d later, and all devices were removed after 6d. After device removal, estrus was monitored and females displaying signs of estrus were mated by fertile bucks. Transrectal ovarian ultrasonography was performed after device removal until detection of ovulation. Blood samples were collected for determination of plasma progesterone concentration at different times. There was no difference (P>0.05) among groups CONTROL, USED6 or USED12 for: estrus response (87, 100 or 100%, respectively); duration of estrus (32.3±2.3, 25.2±3.4 or 27.3±4.1h); ovulation rate (100, 88 or 100%); number of ovulations (1.5±0.2, 1.9±0.3 or 1.7±0.3); and pregnancy rate (60, 58 or 67%). Plasma progesterone (P4) concentrations were greater (P<0.05) in CONTROL than in USED6-treated and USED12-treated goats (7.2±1.2, 4.7±0.7 and 4.3±0.6 ng/mL, respectively) at 6h after device insertion; these differences were maintained until 4d after device insertion (3.4±0.4, 2.3±0.2, and 2.5±0.2 ng/mL). Overall, plasma progesterone concentrations were greater (P<0.05) in nulliparous than in lactating goats (3.1±0.8 compared to 2.4±0.6 ng/mL, respectively). In conclusion, autoclaved, previously used intravaginal progesterone-releasing devices resulted in significant lesser plasma progesterone concentrations than new devices, but were similarly effective in inducing estrus

  10. Cycle-Related Changes in Mood, Sexual Desire, and Sexual Activity in Oral Contraception-Using and Nonhormonal-Contraception-Using Couples.

    PubMed

    Elaut, Els; Buysse, Ann; De Sutter, Petra; Gerris, Jan; De Cuypere, Griet; T'Sjoen, Guy

    2016-01-01

    Findings on women's sexuality across the menstrual cycle are inconsistent. One relatively consistent finding is a midcycle and premenstrual peak in sexual desire in freely cycling women. Results on the cycle-related effects on sexual behavior are less clear. Large proportions of reproductive-aged women use combined oral contraception (COC), but studies on potential cycle-related shifts in sexual desire and behavior are sparse. A prospective diary study assessed sexual desire, sexual behavior, and mood in 89 heterosexual couples. Women were using one of four contraceptive methods: (1) nonhormonal contraception, (2) low-dose COC containing 20 mcg ethinylestradiol and 75 mcg gestoden or desogestrel, (3) COC containing 35 mcg ethinylestradiol and 2 mg cyproteronacetate, and (4) COC containing 30 mcg ethinylestradiol and 3 mg drospirenone. No cycle effects of sexual desire were established in the COC group, but frequency of sexual intercourse declined in the last days of active pill taking. These results were similar in both female and male partners. Negative affect did not covary with sexual desire.

  11. Relationship of follicle size and concentrations of estradiol among cows exhibiting or not exhibiting estrus during a fixed-time AI protocol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cows exhibiting estrus near the time of fixed-time AI had greater pregnancy success than cows showing no estrus. The objective of this study was to determine the relationship between follicle size and peak estradiol concentration between cows that did or did not exhibit estrus during a fixed-time AI...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. Estrus response and fertility after a single cloprostenol treatment in dairy cows with various ovarian structures.

    PubMed

    Hatvani, Csilla; Balogh, Orsolya G; Endrődi, Tamás; Abonyi-Tóth, Zsolt; Holló, István; Kastelic, John P; Gábor, György

    2013-07-01

    The objective of this study was to determine rates of estrus and conception in lactating multiparous Holstein cows given 500 μg of cloprostenol intramuscularly after detection of the following ≥ 60 d after parturition: a solid corpus luteum (CL), a CL with a nonechodense cavity ≤ 20 mm in diameter (CLcav), a luteal cyst (cavity > 20 mm in diameter and a luteinized wall > 3 mm in diameter), or a follicular cyst (cavity > 20 mm and a luteinized wall ≤ 3 mm in diameter). The estrus rates were 335/419 (80.0%), 183/223 (82.1%), 170/182 (93.4%), and 44/87 (50.6%), respectively (P < 0.0001), and the conception rates 30 to 36 d after insemination among the estrous cows with an apparently normal mucus discharge were 130/285 (45.6%), 44/141 (31.2%), 39/79 (49.4%), and 19/30 (63.3%), respectively (P < 0.002). Compared with a solid CL, a CLcav did not affect the estrus rate but significantly reduced the conception rate (P < 0.05), and the estrus rates were significantly higher and lower in cows with a luteal or follicular cyst, respectively (P < 0.05). PMID:24101799

  14. Estrus response and fertility after a single cloprostenol treatment in dairy cows with various ovarian structures

    PubMed Central

    Hatvani, Csilla; Balogh, Orsolya G.; Endrődi, Tamás; Abonyi-Tóth, Zsolt; Holló, István; Kastelic, John P.; Gábor, György

    2013-01-01

    The objective of this study was to determine rates of estrus and conception in lactating multiparous Holstein cows given 500 μg of cloprostenol intramuscularly after detection of the following ≥ 60 d after parturition: a solid corpus luteum (CL), a CL with a nonechodense cavity ≤ 20 mm in diameter (CLcav), a luteal cyst (cavity > 20 mm in diameter and a luteinized wall > 3 mm in diameter), or a follicular cyst (cavity > 20 mm and a luteinized wall ≤ 3 mm in diameter). The estrus rates were 335/419 (80.0%), 183/223 (82.1%), 170/182 (93.4%), and 44/87 (50.6%), respectively (P < 0.0001), and the conception rates 30 to 36 d after insemination among the estrous cows with an apparently normal mucus discharge were 130/285 (45.6%), 44/141 (31.2%), 39/79 (49.4%), and 19/30 (63.3%), respectively (P < 0.002). Compared with a solid CL, a CLcav did not affect the estrus rate but significantly reduced the conception rate (P < 0.05), and the estrus rates were significantly higher and lower in cows with a luteal or follicular cyst, respectively (P < 0.05). PMID:24101799

  15. Effects of fixed time AI and AI at detected estrus on conception rate in smallholder zebu and crossbred heifers and cows subjected to double PGF2α administration.

    PubMed

    Gugssa, Tadesse; Ashebir, Gebregiorgis; Yayneshet, Tesfay

    2016-08-01

    The study was conducted to evaluate estrus response, time to the onset of estrus, and conception rate at fixed time AI and AI at detected estrus in local and crossbred heifers and cows subjected to double administration of PGF2α. One hundred twenty local (heifers, n = 27; cows, n = 33) and crossbreds (heifers, n = 21; cows, n = 39) were used for the study. About 63 and 85.7 % of the local and crossbred heifers, respectively, exhibited estrus. Similarly, all crossbred cows and 90.9 % of local cows showed estrus. Most heifers came to estrus between 48 and 72 h while cows exhibited behavioral signs of estrus between 72 and 96 h. AI at detected estrus resulted in higher conception rate than fixed time AI. Pregnancy per artificial insemination was higher in AI at detected estrus than fixed time AI. Accurate estrus detection followed by insemination are crucial factors in maximizing pregnancy, and this study has demonstrated that conception rate in smallholder heifers and cows should be inseminated following estrus detection to maximize the conception rate of the animals. PMID:27184042

  16. The effect of subclinical ketosis on activity at estrus and reproductive performance in dairy cattle.

    PubMed

    Rutherford, Andrew J; Oikonomou, Georgios; Smith, Robert F

    2016-06-01

    Our aims were to investigate the influence of subclinical ketosis (SCK) on physical activity at estrus using a neck accelerometer device and on future reproductive performance. Two hundred three Holstein-Friesian cows were studied on 3dairy farms in Northwest England between September 2013 and March 2014. Seventeen percent (35 of 203) of the enrolled cows were affected with SCK between 7 and 21d in milk, defined as a blood β-hydroxybutyrate concentration of 1.2 to 2.9mmol/L. Time to event analyses and multivariable regression analyses were used to assess the effect of SCK on reproductive performance and activity at estrus. The SCK cows exhibited a lower peak activity (measured as the number of standard deviations above mean activity) and shorter duration in activity clusters associated with first estrus and first insemination postpartum, compared with non-SCK cows. Peak activity and cluster duration associated with the insemination that led to a pregnancy were not different between SCK and non-SCK cows. Calving to first estrus, calving to first insemination, and calving to pregnancy intervals were prolonged in SCK cows. First insemination was 4.3 times (95% confidence interval=1.6 to 15.0) less likely to be successful in SCK cows compared with non-SCK cows. Adjusted mean number of inseminations per pregnancy was 2.8 for SCK cows and 2.0 for non-SCK cows. The current study confirms the long-lasting effects of SCK on reproductive efficiency. Furthermore, it is indicated that physical activity around estrus is reduced by SCK in early lactation, but this negative effect appears to diminish as cows progress through lactation.

  17. Therapeutic Effects of Pre-Gelatinized Maca (Lepidium Peruvianum Chacon) used as a Non-Hormonal Alternative to HRT in Perimenopausal Women - Clinical Pilot Study

    PubMed Central

    Meissner, H. O.; Reich-Bilinska, H.; Mscisz, A.; Kedzia, B.

    2006-01-01

    significant increase in E2 and FSH, Progesterone and ACTH levels, and reduction in blood pressure, body weight, Triglycerides and Cholesterol levels. There was a distinctive placebo effect observed at the beginning of the study. Conclusions: The results showed that in addition to reduction in body weight, blood pressure and increasing serum HDL and Iron, pre-gelatinized Maca-GO may be a valuable non-hormonal plant preparation for balancing levels of hormones (FSH, E2, PG and ACTH) and alleviating negative physiological and psychological symptoms (frequency of hot flushes, incidence in night sweating, interrupted sleep pattern, nervousness, depression and heart palpitations) experienced by women in perimenopausal stage. It appears that Maca-GO may act as a toner of hormonal processes, leading to alleviation of discomfort felt by perimenopausal women, hence, its potential use as non-hormonal alternative to HRT program. PMID:23674976

  18. Is slow follicular growth the cause of silent estrus in water buffaloes?

    PubMed

    Awasthi, M K; Kavani, F S; Siddiquee, G M; Sarvaiya, N P; Derashri, H J

    2007-06-01

    The present experiment was conducted to study the growth profile of the ovulatory follicle in relation to the expression of estrus following administration of PGF(2alpha) to subestrus buffaloes. After detection of a mature corpus luteum by examination per rectum, confirmed by ultrasound scanning, subestrus buffaloes (n=20) were treated (Day 0) with single dose of Dinoprost tromethamin (25 mg, i.m.). Blood samples were collected at 0, 24 and 48 h after treatment for estimation of plasma progesterone concentration. Growth profile of the ovulatory follicle was monitored daily through ultrasound scanning starting from Day 0 until ovulation and the regression profile of CL was monitored at 0, 24 and 48 h of treatment. Estrus was detected by exposure to a fertile buffalo bull three times a day until expression of overt estrus or ovulation. Behavioral estrus was recorded in 14 animals and 6 animals ovulated silently. Sixteen animals including six animals with silent estrus ovulated from the dominant follicle present at treatment (Group A) and remaining four animals ovulated from the dominant follicle of succeeding follicular wave (Group B). The intervals from treatment to estrus (6.5+/-0.25 versus 3.2+/-0.27 days, P<0.001) and treatment to ovulation (7.5+/-0.25 versus 5.4+/-0.46 days, P<0.005) were significantly longer in animals of Group B compared with animals of Group A. Significant differences were observed in growth profile of the ovulatory follicle between animals of Groups A and B with respect to size of the follicle on Day 0 (9.8+/-0.7 versus 5.3+/-0.45 mm, P<0.001), daily growth rate (0.97+/-0.07 versus 1.6+/-0.2 mm/day, P<0.01) and increase in diameter (4.1+/-0.6 versus 7.8+/-0.7 mm, P<0.01). The animals with silent estrus (subgroup A-2) had significantly smaller diameter of the ovulatory follicle on Day 0 (7.7+/-0.4 versus 11.0+/-0.7 mm, P<0.005), its daily growth rate was significantly slower (0.7+/-0.02 versus 1.1+/-0.1 mm/day, P<0.01) and they recorded

  19. Factors affecting gestation length and estrus cycle characteristics in Spanish donkey breeds reared in southern Spain.

    PubMed

    Galisteo, J; Perez-Marin, C C

    2010-08-01

    This paper investigated gestation length and estrus cycle characteristics in three different Spanish donkey breeds (Andalusian, Zamorano-Leones, and Catalonian) kept on farm conditions in southern Spain, using data for ten consecutive breeding seasons. Gestation length was measured in 58 pregnancies. Ovarian ultrasonography was used to detect the ovulation, in order to ascertain true gestation length (ovulation-parturition). Pregnancy was diagnosed approximately 14-18 d after ovulation and confirmed on approximately day 60. Average gestation length was 362 +/-15.3 (SD) d, and no significant differences were observed between the three different breeds. Breeding season had a significant effect (P < 0.01), with longer gestation lengths when jennies were covered during the early period. Breed, age of jenny, year of birth, foal gender, month of breeding, and type of gestation had no significant effect on gestation length. After parturition, foal-heat was detected in 53.8% of the postpartum cycles studied (n = 78), and ovulation occurred on day 13.2 +/- 2.7. The duration of foal-heat was 4.7 +/-1.7 d, with a pregnancy rate of 40.5%. When subsequent estrus cycles were analyzed, the interovulatory interval (n = 68) and estrus duration (n = 258) were extended to a mean 23.8 +/- 3.5 and 5.7 +/- 2.2 d, respectively. Both variables were influenced by the year of study (P < 0.03 and P < 0.001), whereas month and season of ovulation (P < 0.005 and P < 0.009, respectively) affected only interovulatory intervals. Estrus duration was significantly longer than that observed at the foal-heat (P < 0.006), and the pregnancy rate was 65.8%. This study provides reference values for true gestation length and estrus cycle characteristics in Spanish jennies. Breeding season affected gestation length in farm conditions. Also, seasonal influence was observed on the length of the estrus cycle (i.e., interovulatory interval), although foal-heat was not affected by environmental factors.

  20. Timed artificial insemination with estradiol cypionate or insemination at estrus in high-producing dairy cows.

    PubMed

    Cerri, R L A; Santos, J E P; Juchem, S O; Galvão, K N; Chebel, R C

    2004-11-01

    A total of 799 Holstein cows from 3 herds were randomly assigned at 37 +/- 3 d in milk (DIM) to timed artificial insemination (AI) or insemination at detected estrus. Cows were presynchronized with injections of PGF(2alpha) at 37 and 51 DIM. At 65 DIM, cows received an injection of GnRH, followed 7 d later by PGF(2alpha). Cows in the estrus-detected group were inseminated after being observed in estrus during the 7 d after the last PGF(2alpha). Cows in the timed AI group received an injection of 1 mg of estradiol cypionate (ECP) 24 h after the last PGF(2alpha). If detected in estrus or=1 ng/mL; L = <1 ng/mL), resulting in 8 combinations (LLL, LHL, LLH, LHH, HHH, HHL, HLH, and HLL). Conception rates and pregnancy rates were higher for cows in the timed AI group than in the estrus-detected group at 30, 44, and 58 d (e.g., at 58 d, pregnancy rates were 42.2% for multiparous cows or 34.4% for primiparous cows in the group receiving ECP and timed AI compared with only 20.8 or 18.8% for respective parity subgroups for the treatment group inseminated only at detected estrus). Pregnancy losses were 11.5% from 30 to 58 d and did not differ between treatments. Cyclic cows within both treatments had higher estrous responses, conception rates, and pregnancy rates. Cows that responded to presynchronization and to luteolysis (HHL) had the highest conception and pregnancy rates, followed by cows classified as LHL. Use of 1 mg of ECP to induce

  1. Use of an electronic activity detection system to characterize estrus activity in crossbred beef heifers differing in follicle number

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased numbers of antral follicles have been associated with decreased calving day, increased fertility, increased serum estradiol concentrations, increased serum progesterone concentrations, and increased estrus behavior in cattle. In addition, cows with increased fertility have been shown to h...

  2. Inverse anticipating chaos synchronization.

    PubMed

    Shahverdiev, E M; Sivaprakasam, S; Shore, K A

    2002-07-01

    We derive conditions for achieving inverse anticipating synchronization where a driven time-delay chaotic system synchronizes to the inverse future state of the driver. The significance of inverse anticipating chaos in delineating synchronization regimes in time-delay systems is elucidated. The concept is extended to cascaded time-delay systems.

  3. Pre-service ultrasonic and manual evaluation of the reproductive organs of dairy cows presumed to be in estrus.

    PubMed

    Hansar, Endris; Lemma, Alemayehu; Yilma, Tefera

    2014-01-01

    Manual and ultrasonic evaluation of the the reproductive organs of 62 dairy cows and heifers belonging to smallholder farms was conducted. The objective was to assess the efficiency of visual estrus detection method in the dairy animals that were presented for artificial insemination. Data were collected on reproductive status, body condition, estrus signs, and findings of rectal examination. Thirty-three animals were inseminated after ultrasonic evaluation while 29 animals were inseminated after manual evaluation through rectal palpation. Pregnancy diagnosis was performed using ultrasound 30 days post insemination. The most frequently observed estrus signs by the dairy owners were mucus discharge (83.9%) and mounting (67.7%) while the most frequently confirmed physical signs of estrus by rectal examination were cervical opening (88.7%), and uterine turgidity (82.3%). The overall mean (±SD) diameter of the largest follicle was 12.9 ± 3.4 mm with an average number of 3.5 follicles per ovary. The overall pregnancy rate was 29%. Evaluation of post-insemination records showed a significant difference (P < 0.05) in the diameter of largest follicle between the pregnant (14.7 mm) and non-pregnant (12.1 mm) animals. The mean (±SD) time interval between the first observed estrus sign to service were 10.5 ± 7.0 hrs and 14.5 ± 10.0 hrs for pregnant and non-pregnant, respectively. The low pregnancy rate, delayed time of insemination, and the difference in the size of dominant follicle indicate the incompatibility between visual estrus detection and optimal time of insemination. This confirms the significance of improving estrus detection and the need for combining estrus signs with pre-service evaluation of the reproductive organs either manually or using ultrasound.

  4. Effects of different five-day progesterone-based synchronization protocols on the estrous response and follicular/luteal dynamics in dairy cows.

    PubMed

    López-Gatius, Fernando; López-Helguera, Irene; De Rensis, Fabio; Garcia-Ispierto, Irina

    2015-01-01

    This study compared the responses shown by lactating dairy cows to four different P4-based protocols for AI at estrus. Cows with no estrous signs 96 h after progesterone intravaginal device (PRID) removal were subjected to fixed-time AI (FTAI), and their data were also included in the study. In Experiment I, follicular/luteal and endometrial dynamics were assessed every 12 h from the beginning of treatment until AI. The estrous response was examined in Experiment II, and fertility was assessed in both experiments. The protocols consisted of a PRID fitted for five days, along with the administration of different combinations of gonadotropin releasing hormone (GnRH), equine chorionic gonadotropin and a single or double dose (24 h apart) of prostaglandin F2α. In Experiment I (40 cows), animals receiving GnRH at the start of treatment showed a significantly higher ovulation rate during the PRID insertion period while estrus was delayed. In Experiment II (351 cows), according to the odds ratios, cows showing luteal activity at the time of treatment were less likely to show estrus than cows with no signs of luteal activity. Treatment affected the estrous response and the interval from PRID removal to estrus but did not affect conception rates 28-34 days post AI. Primiparous cows displayed a better estrous response than multiparous cows. Our findings reveal acceptable results of 5-day P4-based protocols for AI at estrus in high-producing dairy cows. Time from treatment to estrus emerged as a good guide for FTAI after a 5-day P4-based synchronization protocol.

  5. Effects of different five-day progesterone-based synchronization protocols on the estrous response and follicular/luteal dynamics in dairy cows

    PubMed Central

    LÓPEZ-GATIUS, Fernando; LÓPEZ-HELGUERA, Irene; DE RENSIS, Fabio; GARCIA-ISPIERTO, Irina

    2015-01-01

    This study compared the responses shown by lactating dairy cows to four different P4-based protocols for AI at estrus. Cows with no estrous signs 96 h after progesterone intravaginal device (PRID) removal were subjected to fixed-time AI (FTAI), and their data were also included in the study. In Experiment I, follicular/luteal and endometrial dynamics were assessed every 12 h from the beginning of treatment until AI. The estrous response was examined in Experiment II, and fertility was assessed in both experiments. The protocols consisted of a PRID fitted for five days, along with the administration of different combinations of gonadotropin releasing hormone (GnRH), equine chorionic gonadotropin and a single or double dose (24 h apart) of prostaglandin F2α. In Experiment I (40 cows), animals receiving GnRH at the start of treatment showed a significantly higher ovulation rate during the PRID insertion period while estrus was delayed. In Experiment II (351 cows), according to the odds ratios, cows showing luteal activity at the time of treatment were less likely to show estrus than cows with no signs of luteal activity. Treatment affected the estrous response and the interval from PRID removal to estrus but did not affect conception rates 28–34 days post AI. Primiparous cows displayed a better estrous response than multiparous cows. Our findings reveal acceptable results of 5-day P4-based protocols for AI at estrus in high-producing dairy cows. Time from treatment to estrus emerged as a good guide for FTAI after a 5-day P4-based synchronization protocol. PMID:26211922

  6. Progestin-impregnated intravaginal sponges for estrus induction and synchronization influences on goats vaginal flora and antimicrobial susceptibility.

    PubMed

    Penna, Bruno; Libonati, Hugo; Director, Ariel; Sarzedas, Ana Clara; Martins, Gabriel; Brandão, Felipe Z; Fonseca, Jeferson; Lilenbaum, Walter

    2013-11-01

    The objective was to characterize vaginal bacteria, their antimicrobial sensitivity, and the incidence of vaginitis, in goats before and after insertion of intravaginal sponges containing progesterone. Sponges were inserted in 37 Saanen goats and removed after 6, 9 or 12d (G6, G9 and G12). At sponge removal, all goats had clinical signs of vaginitis. Sampling was conducted just before sponge insertion and at 0, 24, 48, and 72 h after sponge removal. Vaginal secretions were subjected to standard bacteriological procedures, including isolation of bacteria, subculture, and determination of sensitivity to antimicrobials (gentamicin, cefalotin, tetracycline, ciprofloxacin, trimethoprim-sulfamethoxazole, amoxicillin and clavulanic acid, penicillin G and cefoxitin). Ciprofloxacin, gentamicin, tetracycline and trimethoprim-sulfamethoxazole were the most effective for coliforms (100% sensitivity), whereas ciprofloxacin, gentamicin and tetracycline were the most effective for cocci (100, 98.6 and 97.2% sensitivity, respectively). In contrast, the least effective antimicrobials were cefalotin for the coliforms, and penicillin for the cocci (37.5 and 64.4% sensitivity, respectively), regardless of duration of implant presence and interval from implant removal to sampling. In conclusion, insertion of intravaginal progestin-impregnated sponges induced clinical vaginitis in goats. Members of Staphylococcus genus were the most frequently recovered species of the vaginal samples cultured, and all isolates were resistant to several antimicrobials.

  7. A new automatic synchronizer

    SciTech Connect

    Malm, C.F.

    1995-12-31

    A phase lock loop automatic synchronizer, PLLS, matches generator speed starting from dead stop to bus frequency, and then locks the phase difference at zero, thereby maintaining zero slip frequency while the generator breaker is being closed to the bus. The significant difference between the PLLS and a conventional automatic synchronizer is that there is no slip frequency difference between generator and bus. The PLL synchronizer is most advantageous when the penstock pressure fluctuates the grid frequency fluctuates, or both. The PLL synchronizer is relatively inexpensive. Hydroplants with multiple units can economically be equipped with a synchronizer for each unit.

  8. Timely estrus in wild brown mouse lemur females at Ranomafana National Park, southeastern Madagascar.

    PubMed

    Blanco, Marina B

    2011-06-01

    The small-bodied nocturnal mouse lemurs (genus Microcebus) occupy a variety of habitats in Madagascar. Gray (M. murinus) and brown (M. rufus) mouse lemurs have been widely studied both in the wild and captivity. Whereas captive studies revealed an endogenous regulation of reproduction entrained by photoperiod, field studies have suggested that reproductive activation could be affected by additional climatic, physical, or social conditions. I collected data on wild brown mouse lemur females at Ranomafana between 2004 and 2008 to determine: 1) the timing of estrus and estrous periodicities across multiple seasons, and 2) whether additional factors such as body mass, age, or rainfall are correlated with onset of reproduction. In mouse lemur females at Ranomafana, the first seasonal estrus occurs 3-4 weeks after the vernal equinox. I report ~1 month's intra-population variation in the timing of estrus and inter-annual estrous intervals with periodicities of ~365 days. There were significant differences between the onset of reproduction across years. Estrous onset was uncorrelated with body mass, but there was an apparent age effect. There was a significant negative correlation between August rainfall and onset of reproduction when 2004 data were removed from the analysis. Results from this study are consistent with the notion that timing of estrus is photoperiod-dependent. As in captivity, intra-population variation in estrous onset is ~4 weeks in length. In the wild, variation in estrous onset and polyestry (multiple reproductive opportunities per year) appear to be favored under the highly unpredictable conditions of Madagascar's environments. In the wild, variation in estrous onset and polyestry (multiple reproductive opportunities per year) appear to be favored under the highly unpredictable conditions of Madagascar's environments. PMID:21469075

  9. Conference lecture: influence of stress on estrus, gametes and early embryo development in the sow.

    PubMed

    Einarsson, S; Brandt, Y; Rodriguez-Martinez, H; Madej, A

    2008-11-01

    Systems with loose-housed sows have become common. Regrouping, which is commonly done after weaning and may coincide with many important reproductive events, causes stressful situations with elevated blood cortisol concentrations. Depending on group size, approximately 2-7 d are required for a new group of sows to become relatively stable. In a series of studies, the social stress after regrouping was simulated with repeated adrenocorticotrophic hormone (ACTH) treatments for approximately 48h. Sows were allocated into control and experimental groups, fitted with jugular catheters, and blood samples were collected every 2 or 4h. Follicular development and ovulation were monitored by transrectal ultrasonography every 4h. Simulated stress during pro-estrus prolonged estrus and disturbed the follicular growth and ovulation. Giving ACTH during estrus elevated concentrations of cortisol and progesterone, and changed the intraluminal environment, including exaggerated amounts of mucus in the UTJ and isthmus. Although ACTH had no effect on the time of ovulation (relative to onset of standing estrus), or on embryo development, fewer oocytes/embryos were retrieved from the ACTH group than from the control group (51% vs. 81%, P<0.05), and there was a tendency towards faster embryo transportation to the uterus. Short-term fasting after ovulation had an unfavourable effect on sperm numbers in UTJ/isthmus, cleavage rate of fertilized ova, as well as ova transport through the isthmic part of the oviduct. Treatment with ACTH after ovulation reduced numbers of spermatozoa at the zona pellucida and retarded cleavage rate of fertilized ova. Therefore, the timing of stress seemed to be an important factor regarding effects on reproductive events. PMID:18786720

  10. Synchronization of clocks

    NASA Astrophysics Data System (ADS)

    Kapitaniak, Marcin; Czolczynski, Krzysztof; Perlikowski, Przemysław; Stefanski, Andrzej; Kapitaniak, Tomasz

    2012-08-01

    In this report we recall the famous Huygens’ experiment which gave the first evidence of the synchronization phenomenon. We consider the synchronization of two clocks which are accurate (show the same time) but have pendula with different masses. It has been shown that such clocks hanging on the same beam can show the almost complete (in-phase) and almost antiphase synchronizations. By almost complete and almost antiphase synchronization we defined the periodic motion of the pendula in which the phase shift between the displacements of the pendula is respectively close (but not equal) to 0 or π. We give evidence that almost antiphase synchronization was the phenomenon observed by Huygens in XVII century. We support our numerical studies by considering the energy balance in the system and showing how the energy is transferred between the pendula via oscillating beam allowing the pendula’s synchronization. Additionally we discuss the synchronization of a number of different pendulum clocks hanging from a horizontal beam which can roll on the parallel surface. It has been shown that after a transient, different types of synchronization between pendula can be observed; (i) the complete synchronization in which all pendula behave identically, (ii) pendula create three or five clusters of synchronized pendula. We derive the equations for the estimation of the phase differences between phase synchronized clusters. The evidence, why other configurations with a different number of clusters are not observed, is given.

  11. Study of male effect on feeding and estrus behavior of Afshari ewes.

    PubMed

    Asgari Safdar, Amir Hossein; Sadeghi, Ali Asghar

    2015-01-01

    This study was conducted to evaluate the male effect on the manifestation of estrus and feeding behavior of Afshari ewes during their breeding season. The study consists of 48 Afshari ewes, 3 years old, 67 ± 2 kg live weight, body condition score 3, along with 10 Afshari rams. The study was for a period of 6 weeks in a complementary randomized design. Ewes were equally divided into three treatments (T₁, T₂, and T₃) along with a control (T₄) with six animals in each group. Variable factors of treatments was the distance of the ram box (from the ewes), which was determined to be the T₁(0-5 m), T₂(10-15 m), and T₃(25-30 m). Exposure of the ewes to the rams resulted in an earlier manifestation of estrus signs (p < 0.05). Moreover, the total recorded estrus signs were significantly affected by the distance from the rams (p < 0.05). The result of this study showed differences in feed intake of the ewes due to the distance from the rams (p < 0.05). In the other words, the distance of the ewes from the rams significantly affected feed intake of the Afshari ewes.

  12. Induction of estrus in cattle by intraovarian injection of prostaglandin F2alpha.

    PubMed

    Rayos, A A; Abalos, J A; Cruz, S F; Kanagawa, H

    1990-09-01

    An effective, reduced dosage (1/10 to 1/20 the systemic dose) method for administering prostaglandin F2alpha in heifers to induce estrus is presented in this study. The PGF2alpha was injected intraovarially in five heifers at a dose of 2 mg and in another five heifers at a dose of 1 mg. Five additional heifers were injected intraovarially with 0.5 ml of distilled water and served as the controls. Regression of the corpus luteum (CL) occurred in all PGF2alpha-treated heifers resulting in marked decline of the peripheral levels of progesterone 24 h after treatment. Estrus was expressed 1 to 3 d later. Regression of the CL, estrus, and decline in the peripheral levels of progesterone were not observed in the control heifers. Conception rates in the heifers given either 2 mg and 1 mg PGF(2alpha) were 60 and 100%, respectively. Seven calves were born at the end of the normal gestation period while one calf was aborted.

  13. Synchronization of chaotic systems

    SciTech Connect

    Pecora, Louis M.; Carroll, Thomas L.

    2015-09-15

    We review some of the history and early work in the area of synchronization in chaotic systems. We start with our own discovery of the phenomenon, but go on to establish the historical timeline of this topic back to the earliest known paper. The topic of synchronization of chaotic systems has always been intriguing, since chaotic systems are known to resist synchronization because of their positive Lyapunov exponents. The convergence of the two systems to identical trajectories is a surprise. We show how people originally thought about this process and how the concept of synchronization changed over the years to a more geometric view using synchronization manifolds. We also show that building synchronizing systems leads naturally to engineering more complex systems whose constituents are chaotic, but which can be tuned to output various chaotic signals. We finally end up at a topic that is still in very active exploration today and that is synchronization of dynamical systems in networks of oscillators.

  14. Synchronization of chaotic systems.

    PubMed

    Pecora, Louis M; Carroll, Thomas L

    2015-09-01

    We review some of the history and early work in the area of synchronization in chaotic systems. We start with our own discovery of the phenomenon, but go on to establish the historical timeline of this topic back to the earliest known paper. The topic of synchronization of chaotic systems has always been intriguing, since chaotic systems are known to resist synchronization because of their positive Lyapunov exponents. The convergence of the two systems to identical trajectories is a surprise. We show how people originally thought about this process and how the concept of synchronization changed over the years to a more geometric view using synchronization manifolds. We also show that building synchronizing systems leads naturally to engineering more complex systems whose constituents are chaotic, but which can be tuned to output various chaotic signals. We finally end up at a topic that is still in very active exploration today and that is synchronization of dynamical systems in networks of oscillators.

  15. Synchronized ovulation for first insemination improves reproductive performance and reduces cost per pregnancy in dairy heifers.

    PubMed

    Silva, T V; Lima, F S; Thatcher, W W; Santos, J E P

    2015-11-01

    The objectives were to evaluate the effects of synchronizing estrus and ovulation to implement a timed artificial insemination (AI) at first insemination on reproductive performance and cost per pregnancy in dairy heifers. Six hundred eleven Holsteins heifers at approximately 400 d of age from 3 farms were enrolled in the study. Six days before moving to the breeding pens, heifers were allocated randomly to AI after detected estrus from study d 0 to 84 (CON, n=306), or to timed AI for first AI followed by detected estrus for the remainder of the 84-d study (TAI, n=305). Heifers receiving TAI were enrolled in the 5-d timed AI protocol on study d -6 (d -6, GnRH and a progesterone insert; d -1, PGF2α and insert removal; d 0, PGF2α; d 2, GnRH + AI), and they were allowed to be bred the day before scheduled timed AI if detected in estrus. Starting on study d 0, estrus was detected daily. Heifers in estrus were inseminated on the same morning as detected estrus. Control heifers not inseminated by study d 7 received PGF2α and this treatment was repeated every 2 wk until AI. The study lasted 84 d to allow a period of breeding equivalent to four 21-d estrous cycles. A herd budget accounting for inputs for both treatments was created to determine the cost per pregnancy. Sensitivity analysis compared economic differences between the 2 treatments under different input scenarios when detection of estrus after the first AI varied from 50 to 80%. Interval to first AI was 8 d shorter for TAI than for CON. Pregnancy at first AI did not differ between treatments (CON=58.3 vs. TAI=62.8%). In contrast, TAI increased pregnancy per AI (P/AI) compared with CON in heifers inseminated with sex-sorted semen (CON=31.6 vs. TAI=54.8%). The 21-d cycle insemination rate was greater for TAI (91.4%) than for CON (82.4%), even when evaluated after the first 21 d in the study (CON=68.2 vs. TAI=77.1%). The increased insemination rate improved the 21-d cycle pregnancy rate from 47.9% in CON to 57

  16. Impacts of incorporation of follicle stimulating hormone into an estrous synchronization protocol for timed artificial insemination of crossbred beef cattle.

    PubMed

    Gentry, G T; Walker, R S; Gentry, L R

    2016-05-01

    One-hundred-eighty crossbred beef cows and 66 crossbred beef heifers across three locations were stratified by body weight (BW), body condition score (BCS), and age (within location) to evaluate administration of follicle stimulating hormone (FSH) on Day 2 using a modified 7-day CO-Synch plus CIDR(®) protocol (Day 0=CIDR insertion) with timed-artificial insemination (TAI) at 72 h (cows) or 54 h (heifers) following CIDR removal. Estrous response following CIDR removal was determined using an Estrotect patch and TAI and final pregnancy rates were determined by transrectal ultrasonography 42-45 days following TAI and ≥ 45 days following removal of clean-up bulls. Estrous response rate, TAI and final pregnancy rates for cows were not affected (P ≥ 0.65) by treatment. Cows that exhibited estrus had greater (P<0.01) TAI pregnancy rate (66%) than cows not exhibiting estrus (38%). There was an estrous response by postpartum length interaction (P=0.02) where cows exhibiting estrus and ≥ 55 days postpartum had greater TAI pregnancy rates (75%) compared to cows not exhibiting estrus and < 55 days postpartum (39%) or ≥ 55 days postpartum (28%). For heifers, timed AI (P=0.46) and final pregnancy rates (P=0.45) were similar across treatments and estrous response had no effect (P=0.30) on TAI pregnancy rates. In conclusion, the addition of FSH to the CO-Synch plus CIDR estrous synchronization protocol did not increase TAI pregnancy rates in beef cows or heifers. However, a positive estrous response to the synchronization protocol was associated with increased TAI pregnancy rates in cows.

  17. Synchronizing large systolic arrays

    SciTech Connect

    Fisher, A.L.; Kung, H.T.

    1982-04-01

    Parallel computing structures consist of many processors operating simultaneously. If a concurrent structure is regular, as in the case of systolic array, it may be convenient to think of all processors as operating in lock step. Totally synchronized systems controlled by central clocks are difficult to implement because of the inevitable problem of clock skews and delays. An alternate means of enforcing necessary synchronization is the use of self-timed, asynchronous schemes, at the cost of increased design complexity and hardware cost. Realizing that different circumstances call for different synchronization methods, this paper provides a spectrum of synchronization models; based on the assumptions made for each model, theoretical lower bounds on clock skew are derived, and appropriate or best-possible synchronization schemes for systolic arrays are proposed. This paper represents a first step towards a systematic study of synchronization problems for large systolic arrays.

  18. Synchronization via Hydrodynamic Interactions

    NASA Astrophysics Data System (ADS)

    Kendelbacher, Franziska; Stark, Holger

    2013-12-01

    An object moving in a viscous fluid creates a flow field that influences the motion of neighboring objects. We review examples from nature in the microscopic world where such hydrodynamic interactions synchronize beating or rotating filaments. Bacteria propel themselves using a bundle of rotating helical filaments called flagella which have to be synchronized in phase. Other micro-organisms are covered with a carpet of smaller filaments called cilia on their surfaces. They beat highly synchronized so that metachronal waves propagate along the cell surfaces. We explore both examples with the help of simple model systems and identify generic properties for observing synchronization by hydrodynamic interactions.

  19. Synchronous Energy Technology

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The synchronous technology requirements for large space power systems are summarized. A variety of technology areas including photovoltaics, thermal management, and energy storage, and power management are addressed.

  20. Frame synchronization in PCM telemetry.

    NASA Technical Reports Server (NTRS)

    Peavey, B.

    1971-01-01

    The frame synchronization performance characteristics are defined that can be measured under actual operating conditions. The frame synchronization process is explained, and test data on the performance of frame synchronizers and frame synchronization codes are presented. The application of frame synchronization methods in specific cases is considered in the light of code selection, frame length, and data recovery.

  1. Ovarian activity and estrus behavior in early postpartum cows grazing Leucaena leucocephala in the tropics.

    PubMed

    Bottini-Luzardo, Maria; Aguilar-Perez, Carlos; Centurion-Castro, Fernando; Solorio-Sanchez, Francisco; Ayala-Burgos, Armin; Montes-Perez, Ruben; Muñoz-Rodriguez, David; Ku-Vera, Juan

    2015-12-01

    The legume Leucaena leucocephala (Leucaena) is widely used to supplement forage in silvopastoral livestock systems in Latin America. Little is known about its possible effects on the cow reproductive dynamic. The aim was to evaluate the effect of Leucaena foliage intake on re-establishment of ovarian activity and estrus behavior in early postpartum (7-90 days) cows. Twenty-four multiparous Bos taurus × Bos indicus cows were divided into two homogenous groups and assigned to one of two treatments: a silvopastoral system (SS, n = 12), consisting of an association of Cynodon nlemfuensis grass and L. leucocephala; and a control system (CS, n = 12), consisting of C. nlemfuensis alone. Intake of Leucaena in the SS ranged from 3.80 to 6.43 kg DM/cow/day. Plasma mimosine concentrations ranged from 1270 to 1530 μg/mL, and those for 2,3-dihydroxypyridine (DHP) from 147 to 729 μg/mL. No 3,4-DHP was detected in plasma. No difference (P > 0.05) between treatments was observed for the number of cows exhibiting small, medium, or dominant follicles, or estrus behavior. The number of cows which re-established ovarian cyclicity (n = 6) was lower (P < 0.05) in the SS than in the CS (n = 9). Corpus luteum lifespan was longer (P < 0.05) in the SS than in the CS. Intake of Leucaena affected the number of cows exhibiting ovarian cyclicity and extended corpus luteum life, but did not affect follicular development and estrus behavior. PMID:26210396

  2. Ovarian activity and estrus behavior in early postpartum cows grazing Leucaena leucocephala in the tropics.

    PubMed

    Bottini-Luzardo, Maria; Aguilar-Perez, Carlos; Centurion-Castro, Fernando; Solorio-Sanchez, Francisco; Ayala-Burgos, Armin; Montes-Perez, Ruben; Muñoz-Rodriguez, David; Ku-Vera, Juan

    2015-12-01

    The legume Leucaena leucocephala (Leucaena) is widely used to supplement forage in silvopastoral livestock systems in Latin America. Little is known about its possible effects on the cow reproductive dynamic. The aim was to evaluate the effect of Leucaena foliage intake on re-establishment of ovarian activity and estrus behavior in early postpartum (7-90 days) cows. Twenty-four multiparous Bos taurus × Bos indicus cows were divided into two homogenous groups and assigned to one of two treatments: a silvopastoral system (SS, n = 12), consisting of an association of Cynodon nlemfuensis grass and L. leucocephala; and a control system (CS, n = 12), consisting of C. nlemfuensis alone. Intake of Leucaena in the SS ranged from 3.80 to 6.43 kg DM/cow/day. Plasma mimosine concentrations ranged from 1270 to 1530 μg/mL, and those for 2,3-dihydroxypyridine (DHP) from 147 to 729 μg/mL. No 3,4-DHP was detected in plasma. No difference (P > 0.05) between treatments was observed for the number of cows exhibiting small, medium, or dominant follicles, or estrus behavior. The number of cows which re-established ovarian cyclicity (n = 6) was lower (P < 0.05) in the SS than in the CS (n = 9). Corpus luteum lifespan was longer (P < 0.05) in the SS than in the CS. Intake of Leucaena affected the number of cows exhibiting ovarian cyclicity and extended corpus luteum life, but did not affect follicular development and estrus behavior.

  3. Precise clock synchronization protocol

    NASA Astrophysics Data System (ADS)

    Luit, E. J.; Martin, J. M. M.

    1993-12-01

    A distributed clock synchronization protocol is presented which achieves a very high precision without the need for very frequent resynchronizations. The protocol tolerates failures of the clocks: clocks may be too slow or too fast, exhibit omission failures and report inconsistent values. Synchronization takes place in synchronization rounds as in many other synchronization protocols. At the end of each round, clock times are exchanged between the clocks. Each clock applies a convergence function (CF) to the values obtained. This function estimates the difference between its clock and an average clock and corrects its clock accordingly. Clocks are corrected for drift relative to this average clock during the next synchronization round. The protocol is based on the assumption that clock reading errors are small with respect to the required precision of synchronization. It is shown that the CF resynchronizes the clocks with high precision even when relatively large clock drifts are possible. It is also shown that the drift-corrected clocks remain synchronized until the end of the next synchronization round. The stability of the protocol is proven.

  4. EEG synchronization and migraine

    NASA Astrophysics Data System (ADS)

    Stramaglia, Sebastiano; Angelini, Leonardo; Pellicoro, Mario; Hu, Kun; Ivanov, Plamen Ch.

    2004-03-01

    We investigate phase synchronization in EEG recordings from migraine patients. We use the analytic signal technique, based on the Hilbert transform, and find that migraine brains are characterized by enhanced alpha band phase synchronization in presence of visual stimuli. Our findings show that migraine patients have an overactive regulatory mechanism that renders them more sensitive to external stimuli.

  5. Disorder induces explosive synchronization.

    PubMed

    Skardal, Per Sebastian; Arenas, Alex

    2014-06-01

    We study explosive synchronization, a phenomenon characterized by first-order phase transitions between incoherent and synchronized states in networks of coupled oscillators. While explosive synchronization has been the subject of many recent studies, in each case strong conditions on the heterogeneity of the network, its link weights, or its initial construction are imposed to engineer a first-order phase transition. This raises the question of how robust explosive synchronization is in view of more realistic structural and dynamical properties. Here we show that explosive synchronization can be induced in mildly heterogeneous networks by the addition of quenched disorder to the oscillators' frequencies, demonstrating that it is not only robust to, but moreover promoted by, this natural mechanism. We support these findings with numerical and analytical results, presenting simulations of a real neural network as well as a self-consistency theory used to study synthetic networks.

  6. Synchronous Discrete Harmonic Oscillator

    SciTech Connect

    Antippa, Adel F.; Dubois, Daniel M.

    2008-10-17

    We introduce the synchronous discrete harmonic oscillator, and present an analytical, numerical and graphical study of its characteristics. The oscillator is synchronous when the time T for one revolution covering an angle of 2{pi} in phase space, is an integral multiple N of the discrete time step {delta}t. It is fully synchronous when N is even. It is pseudo-synchronous when T/{delta}t is rational. In the energy conserving hyperincursive representation, the phase space trajectories are perfectly stable at all time scales, and in both synchronous and pseudo-synchronous modes they cycle through a finite number of phase space points. Consequently, both the synchronous and the pseudo-synchronous hyperincursive modes of time-discretization provide a physically realistic and mathematically coherent, procedure for dynamic, background independent, discretization of spacetime. The procedure is applicable to any stable periodic dynamical system, and provokes an intrinsic correlation between space and time, whereby space-discretization is a direct consequence of background-independent time-discretization. Hence, synchronous discretization moves the formalism of classical mechanics towards that of special relativity. The frequency of the hyperincursive discrete harmonic oscillator is ''blue shifted'' relative to its continuum counterpart. The frequency shift has the precise value needed to make the speed of the system point in phase space independent of the discretizing time interval {delta}t. That is the speed of the system point is the same on the polygonal (in the discrete case) and the circular (in the continuum case) phase space trajectories.

  7. Serum estradiol-17beta, vaginal cytology and vulval appearance as predictors of estrus cyclicity in the female collared peccary (Tayassu tajacu) from the eastern Amazon region.

    PubMed

    Mayor, Pedro; Galvez, Hugo; Guimaraes, Diva Anelie; Lopez-Gatius, Fernando; Lopez-Bejar, Manel

    2007-01-01

    This report describes the characteristics of estrus in the female collared peccary (Tayassu tajacu) from the eastern Amazon. Two consecutive experiments were performed. The objective of the first experiment was to assess the efficacy of estrus diagnosis by serum estradiol-17beta measurements, vaginal cytology and vulval appearance. The second experiment was designed to evaluate the effectiveness of these features for predicting the period of mating acceptance. In Experiment 1, we monitored 56 presumptive estruses in 14 captive females. Estrus was characterized by the reddish and tumescent appearance of the vulva, the presence of vaginal mucus and vaginal opening, which persisted for 4, 4, 2, and 2 days, respectively. In vaginal smears, superficial plus intermediate cells became predominant (accounting for 60% of all cells) for a 4-day period, from 2 days before the estradiol-17beta peak. Superficial cells did not attain their maximum density (45% of all cells) until approximately 1 day before the serum estradiol-17beta peak. Following estrus, superficial and intermediate cells were notably reduced and the appearance of the vulval appearance was characterized by a pale, non-tumescent vulva and vaginal closure. A complete concordance in estrus diagnosis by the 3 methodologies was observed in 35 (62.5%) of the total 56 estrus predictions. In Experiment 2, mating was confirmed in 10 out of the 14 cyclic females. Sexual receptivity was observed in the last third of the period during which secondary estrus signs were shown. In conclusion, examining the vulval appearance and taking a vaginal smear constitutes a useful method of detecting estrus and predicting the period of male acceptance of the collared peccary female. Estrus was indicated by a predominance of superficial cells, and a proportion of superficial plus intermediate cells higher than 60% in the vaginal smear.

  8. Abortion and subsequent excretion of chlamydiae from the reproductive tract of sheep during estrus.

    PubMed Central

    Papp, J R; Shewen, P E; Gartley, C J

    1994-01-01

    Chlamydia psittaci serovar 1 infection in pregnant sheep typically causes abortion or the birth of weak lambs. Eight sheep that experienced chlamydia-induced abortion during their first pregnancy were successfully rebred yearly for the past 2 years. Chlamydia-specific lipopolysaccharide was detectable for approximately 3 weeks in vaginal swabs taken from the experimentally infected sheep following abortion. There was no evidence of chlamydiae in vaginal, placental, or neonatal samples obtained immediately after each subsequent successful pregnancy. Sera collected from the experimentally infected sheep had persistent, high antibody levels to C. psittaci, suggesting continued exposure of the immune system to the organism. Examination of vaginal specimens obtained during various stages of the estrus cycle revealed detectable levels of chlamydiae only when the animal was near ovulation. Chlamydiae were not detected in swabs from sheep that did not experience abortion. Enhanced chlamydial excretion during the periovulation period of sheep may provide sufficient stimulation of the immune system to account for the persistent antibody response. Furthermore, the association between estrus and chlamydial shedding has important implications for transmission of infection to other ewes during breeding. PMID:8063395

  9. Synchronization of Swimming Microorganisms

    NASA Astrophysics Data System (ADS)

    Elfring, Gwynn; Lauga, Eric

    2009-11-01

    Flagellated eukaryotic cells (such as spermatozoa) have been observed to synchronize their flagella when swimming in close proximity. Using a 2D model, we find that hydrodynamic interactions alone can lead to synchronization if the waveforms of the flagella display front-back asymmetry. Depending on the nature of the asymmetry, the phase-locked conformation can minimize or maximize the energy dissipated by the co-swimming cells. We show that due to kinematic reversibility, this front-back asymmetry is necessary for synchronization in a Newtonian fluid, and discuss the differences in a non-Newtonian fluid.

  10. Synchronization in complex networks

    SciTech Connect

    Arenas, A.; Diaz-Guilera, A.; Moreno, Y.; Zhou, C.; Kurths, J.

    2007-12-12

    Synchronization processes in populations of locally interacting elements are in the focus of intense research in physical, biological, chemical, technological and social systems. The many efforts devoted to understand synchronization phenomena in natural systems take now advantage of the recent theory of complex networks. In this review, we report the advances in the comprehension of synchronization phenomena when oscillating elements are constrained to interact in a complex network topology. We also overview the new emergent features coming out from the interplay between the structure and the function of the underlying pattern of connections. Extensive numerical work as well as analytical approaches to the problem are presented. Finally, we review several applications of synchronization in complex networks to different disciplines: biological systems and neuroscience, engineering and computer science, and economy and social sciences.

  11. Advanced synchronous luminescence system

    DOEpatents

    Vo-Dinh, Tuan

    1997-01-01

    A method and apparatus for determining the condition of tissue or otherwise making chemical identifications includes exposing the sample to a light source, and using a synchronous luminescence system to produce a spectrum that can be analyzed for tissue condition.

  12. Avoided Crossing and Synchronization

    NASA Astrophysics Data System (ADS)

    Sekii, T.; Shibahashi, H.

    2013-12-01

    We examine avoided crossing of stellar pulsations in the nonlinear regime, where synchronization may occur, based on a simple model of weakly coupled van der Pol oscillators with close frequencies. For this simple case, avoided crossing is unaffected in the sense that there is a frequency difference between the symmetric and antisymmetric modes, but as a result of synchronization, unlike the linear oscillations case, the system can vibrate in only one of the modes.

  13. Synchronization of cells.

    PubMed

    Sonoda, Eiichiro

    2006-01-01

    Synchronization of cells is essential to study cell cycle specific events. If, for example, one suspects that a given DNA repair pathway is used in a particular cell cycle phase, the protocol can be used to enrich cells in each phase of the cell cycle and analyze the cellular response to DNA damage. Synchronization is also useful, when a gene is essential for a particular phase of the cell cycle. If a gene is, for example, essential for mitosis, synchronization of the cells in G1 phase with concomitant inactivation of the gene enables us to study the function of the gene in interphase, and to follow synchronous cell cycle progression to M phase. Two synchronization methods: centrifugal elutriation to enrich G1, S or G2 phase cells and nocodazole-mimocine sequential treatment to enrich cells at the G1/S boundary are described. Centrifugal elutriation can be achieved in less time (0.5-2 h) and with very little physiological stress to the cells whereas synchronization by drugs, such as nocodazole and mimocine, may result in unfavorable side effects.

  14. A pre-synchronization program at early postpartum might increase the chances of Bos indicus cows cycling prior to 50 days regardless of the length of calf separation

    PubMed Central

    PÉREZ-TORRES, Libia; RUBIO, Ivette; CORRO, Manuel; COHEN, Abraham; ORIHUELA, Agustín; GALINA, Carlos S.; PABLOS, J. Luis

    2015-01-01

    The aim of this study was to establish if pre-synchronization would enhance the number of animals cycling prior to conventional breeding at 45 days irrespective of the length of calf separation. Multiparous Bos indicus cows were allotted in four groups (n = 10). Control group (C) dams remained with their calves; groups G24, G48 and G72, which were partially weaned for 24, 48 and 72 h, respectively, were estrus synchronized using a controlled internal drug. These procedures were performed at 25 days and again at 45 days postpartum. The number of follicles, presence of a corpus luteum and back fat thickness (BFT) were determined by ultrasound. The proportion of cows with estrus and ovulation at day 25 postpartum was statistically different between the control and treated groups, with the values being 20, 60, 50 and 70 for the control, G24, G48 and G72 groups respectively (P < 0.05). At days 45 postpartum, the proportion of cows with estrus and ovulation was different in group G48 compared with the other groups (P <0.05). The average BFT and body condition score for the four experimental groups in the two periods were similar (P >0.05). Animals with a higher proportion of follicles from 17 to 21 mm, BFT values above 3.5 mm and a regular body condition were significantly different regardless of whether the dams remained with their calves or were separated, regardless of the length of this event. It can be concluded that (1) a pre-synchronization program at day 25 could trigger the onset of ovarian activity and facilitate a breeding program at day 50 and (2) temporary weaning enhances the effect of a pre-synchronization program. PMID:25739397

  15. A pre-synchronization program at early postpartum might increase the chances of Bos indicus cows cycling prior to 50 days regardless of the length of calf separation.

    PubMed

    Pérez-Torres, Libia; Rubio, Ivette; Corro, Manuel; Cohen, Abraham; Orihuela, Agustín; Galina, Carlos S; Pablos, J Luis

    2015-01-01

    The aim of this study was to establish if pre-synchronization would enhance the number of animals cycling prior to conventional breeding at 45 days irrespective of the length of calf separation. Multiparous Bos indicus cows were allotted in four groups (n = 10). Control group (C) dams remained with their calves; groups G24, G48 and G72, which were partially weaned for 24, 48 and 72 h, respectively, were estrus synchronized using a controlled internal drug. These procedures were performed at 25 days and again at 45 days postpartum. The number of follicles, presence of a corpus luteum and back fat thickness (BFT) were determined by ultrasound. The proportion of cows with estrus and ovulation at day 25 postpartum was statistically different between the control and treated groups, with the values being 20, 60, 50 and 70 for the control, G24, G48 and G72 groups respectively (P < 0.05). At days 45 postpartum, the proportion of cows with estrus and ovulation was different in group G48 compared with the other groups (P <0.05). The average BFT and body condition score for the four experimental groups in the two periods were similar (P >0.05). Animals with a higher proportion of follicles from 17 to 21 mm, BFT values above 3.5 mm and a regular body condition were significantly different regardless of whether the dams remained with their calves or were separated, regardless of the length of this event. It can be concluded that (1) a pre-synchronization program at day 25 could trigger the onset of ovarian activity and facilitate a breeding program at day 50 and (2) temporary weaning enhances the effect of a pre-synchronization program.

  16. First postpartum estrus and pregnancy in the female collared peccary (Tayassu tajacu) from the amazon.

    PubMed

    Mayor, Pedro; Guimaraes, Diva Anelie; Lopez-Gatius, Fernando; Lopez-Bejar, Manel

    2006-11-01

    The onset of sexual cycle postpartum was described in the collared peccary (Tayassu tajacu). Serum progesterone and 17beta-estradiol profiles, vaginal smears and external genitalia were analyzed in 20 animals housed with their piglets during the first postpartum month. The appearance of external genitalia showed no variation in any of the females: a shallow, reddish vulva, and vaginal mucus were constant features throughout the study. Based on hormonal profiles and vaginal smear cell patterns, 16 (80%) of the 20 peccaries showed signs of estrus and were considered cycling. The remaining four females (20%) did no show signs of estrus confirmed by low levels of progesterone (0.9+/-0.4 ng/mL) during the first postpartum month. In the cycling peccaries, a serum 17beta-estradiol peak (53.4+/-8.1 pg/mL) was observed on Day 7+/-1 postpartum, along with a linear increase in progesterone concentration from 3 (4.3+/-2.6 ng/mL) to 11 (30.8+/-4.9 ng/mL) days after this estradiol peak. Proportions of the different cells of the vaginal epithelium also changed in these females: superficial plus intermediate cells amounted to 76% of the cell total between Days 6 and 9 postpartum, corresponding to the estradiol peak. Nine (56%) of the 16 cycling females mated, indicated by the presence of sperm cells in their vaginal smears, and 6 (67%) became pregnant, reaching term. Non-pregnant cycling females (n=10) showed a steady decrease in serum progesterone concentration from 11 to 23 days after the estradiol peak, when basal levels were attained and a new estradiol peak registered, indicating the resumption of cyclicity in these females. The time interval between the two estradiol peaks was 23.5+/-2.1 days in these females. In pregnant females, progesterone concentrations continued to rise to levels of 60 ng/mL (n=6) 23 days after mating. These findings indicate that the lactating collared peccary female can become cycling and fertile during the early postpartum period, and that a

  17. Synchronization between beating cilia.

    PubMed

    Gheber, L; Priel, Z

    1989-01-01

    A novel quantitative parameter is proposed to define and measure the degree of synchronization between two small ciliary areas. These areas can be close to or far from one another. The Pearson correlation factor is used to define the degree of synchronization by a single number. This approach is based on a computerized, dual photoelectric method which simulataneously measures the scattered light from two small areas on the ciliary epithelium or its tissue culture. The measurements were performed on tissue culture from frog's palate epithelium. It was found that: (a) the degree of synchronization decreases, as a function of distance; (b) the correlation is fairly high even at relatively large separations, when measured on the same patch; (c) on a given patch the synchronization factor is independent of the direction of the metachronal wave; (d) close disconnected ciliary cells exhibit fairly high correlation; (e) disconnected randomly choosen ciliary cells at relatively large separation distances exhibit relatively low correlation, smaller by a factor of 2 than the correlation factor at the same distances when measured along the metachronal wave; (f) the average frequencies' ratio and the metachronal wavelength can be used as first-order indicators of ciliary synchronization; (g) there is a spread of metachronal wavelengths even over a single well-organized patch.

  18. Synchronization between beating cilia.

    PubMed Central

    Gheber, L; Priel, Z

    1989-01-01

    A novel quantitative parameter is proposed to define and measure the degree of synchronization between two small ciliary areas. These areas can be close to or far from one another. The Pearson correlation factor is used to define the degree of synchronization by a single number. This approach is based on a computerized, dual photoelectric method which simulataneously measures the scattered light from two small areas on the ciliary epithelium or its tissue culture. The measurements were performed on tissue culture from frog's palate epithelium. It was found that: (a) the degree of synchronization decreases, as a function of distance; (b) the correlation is fairly high even at relatively large separations, when measured on the same patch; (c) on a given patch the synchronization factor is independent of the direction of the metachronal wave; (d) close disconnected ciliary cells exhibit fairly high correlation; (e) disconnected randomly choosen ciliary cells at relatively large separation distances exhibit relatively low correlation, smaller by a factor of 2 than the correlation factor at the same distances when measured along the metachronal wave; (f) the average frequencies' ratio and the metachronal wavelength can be used as first-order indicators of ciliary synchronization; (g) there is a spread of metachronal wavelengths even over a single well-organized patch. PMID:2930819

  19. Optimistic barrier synchronization

    NASA Technical Reports Server (NTRS)

    Nicol, David M.

    1992-01-01

    Barrier synchronization is fundamental operation in parallel computation. In many contexts, at the point a processor enters a barrier it knows that it has already processed all the work required of it prior to synchronization. The alternative case, when a processor cannot enter a barrier with the assurance that it has already performed all the necessary pre-synchronization computation, is treated. The problem arises when the number of pre-sychronization messages to be received by a processor is unkown, for example, in a parallel discrete simulation or any other computation that is largely driven by an unpredictable exchange of messages. We describe an optimistic O(log sup 2 P) barrier algorithm for such problems, study its performance on a large-scale parallel system, and consider extensions to general associative reductions as well as associative parallel prefix computations.

  20. Synchronous trifocal colorectal cancer

    PubMed Central

    Charalampoudis, Petros; Kykalos, Stylianos; Stamopoulos, Paraskevas; Kouraklis, Gregory

    2016-01-01

    Synchronous colorectal cancers (SCRCs) have been increasingly diagnosed due to emerging diagnostic modalities. The presence of three or more synchronous colorectal cancers has, however, only rarely been reported. A 76-year-old white man presented for management of two concurrent colorectal adenocarcinomas in the left colon evidenced on total colonoscopy. Preoperative abdominal ultrasonography and thoracoabdominal computed tomography were negative for metastatic disease. The patient underwent an elective left hemicolectomy. The pathology report ultimately showed the presence of three moderately differentiated, distinct colorectal cancers. The patient experienced an uneventful recovery. PMID:27695171

  1. Synchronous trifocal colorectal cancer

    PubMed Central

    Charalampoudis, Petros; Kykalos, Stylianos; Stamopoulos, Paraskevas; Kouraklis, Gregory

    2016-01-01

    Synchronous colorectal cancers (SCRCs) have been increasingly diagnosed due to emerging diagnostic modalities. The presence of three or more synchronous colorectal cancers has, however, only rarely been reported. A 76-year-old white man presented for management of two concurrent colorectal adenocarcinomas in the left colon evidenced on total colonoscopy. Preoperative abdominal ultrasonography and thoracoabdominal computed tomography were negative for metastatic disease. The patient underwent an elective left hemicolectomy. The pathology report ultimately showed the presence of three moderately differentiated, distinct colorectal cancers. The patient experienced an uneventful recovery.

  2. Estrus induction and fertility rates in response to exogenous hormonal administration in postpartum anestrous and subestrus bovines and buffaloes.

    PubMed

    Honparkhe, M; Singh, Jagir; Dadarwal, D; Dhaliwal, G S; Kumar, Ajeet

    2008-12-01

    A total of 130 animals (82 cattle, 48 buffaloes) with histories of anestrous 60-90 days post-partum and belonging to different agroclimatic zones of Punjab were subjected to rectal palpation and blood samplings at least three times at weekly intervals. The body condition score (BCS) of each animal was also recorded. The animals were divided into two groups; viz., true anestrous (Gp-I) and subestrus (Gp-II) through rectal palpation of ovaries and plasma progesterone (P4) concentrations. Furthermore, the Gp I and II animals were divided into treatment (Gp Ia, 40 cattle and 16 buffaloes; Gp IIa, 12 cattle and 14 buffaloes) and control groups (Gp Ib, 20 cattle and 8 buffaloes; Gp IIb, 10 cattle and 10 buffaloes). True anestrous animals (Gp Ia) were treated with 3 injections of hydroxyprogesterone caproate (750 mg, i.m.) at 72-hr intervals followed by injection of equine chorionic gonadotropin (eCG; 750 I.U., i.m.) 72 hr after the last progesterone injection. The animals were bred at the first estrus after the induced one. The first service conception rate (FSCR), overall conception rate (OCR), services per conception and pregnancy rate of the true anestrous treated cattle (Gp Ia) were 44.4%, 48.0%, 2.08 and 60.0%, respectively. In the true anestrous control cattle (Gp Ib), only five that were observed to be in estrus failed to conceive. In the anestrous treated buffaloes (Gp Ia), the FSCR, OCR, services per conception and pregnancy rate were 50.0%, 62.5%, 1.6 and 62.5%, respectively. No buffalo amongst true anestrous control (Gp Ib) showed estrus. The subestrus animals (Gp IIa) were administered Prostaglandin F(2alpha) (PGF(2alpha); 25 mg Dinoprost, i.m.) and bred at induced estrus. Amongst the Gp IIa animals, all cattle (100%) and twelve buffaloes (85.7%) responded to treatment. Of these animals, the FSCR and pregnancy rate at induced estrus in the cattle were 50.0% each, whereas they were 66.6% and 57.1%, respectively, in the buffaloes. The subestrus control animals

  3. Enhance of the estrus and ovulation sychronism in ewes using protocols with progesterone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estrous synchronization in combination with artificial insemination is an important biotechnology that enables greater and more efficient use of cryopreserved germplasm. However, when using this technology fertility rates after fixed-time artificial insemination (FTAI) still exist because of variati...

  4. Synchronized time stamp support

    SciTech Connect

    Kowalkowski, J.

    1994-02-16

    New software has been added to IOC core to maintain time stamps. The new software has the ability to maintain time stamps over all IOCs on a network. The purpose of this paper is to explain how EPICS will synchronize the time stamps. In addition, this paper will explain how to configure and use the new EPICS time stamp support software.

  5. Advanced synchronous luminescence system

    DOEpatents

    Vo-Dinh, T.

    1997-02-04

    A method and apparatus are disclosed for determining the condition of tissue or otherwise making chemical identifications includes exposing the sample to a light source, and using a synchronous luminescence system to produce a spectrum that can be analyzed for tissue condition. 14 figs.

  6. Synchronous semiconductor memory device

    SciTech Connect

    Onno, C.; Hirata, M.

    1989-11-21

    This patent describes a synchronous semiconductor memory device. It comprises: first latch means for latching a write command in synchronism with clock signal; second latch means for latching a write data in synchronism with the clock signal and for outputting two write process signals based on the write data latched thereby; pulse generating means for generating an internal write pulse signal based on the write command latched by the first latch means. The internal write pulse signal having a semiconductor memory device; write control means supplied with the internal write pulse signal and the write process signals for controlling write and read operations of the synchronous semiconductor memory device; memory means for storing the write data latched by the second latch means; and noise preventing means coupled to the second latch means and the write control means for supplying the write process signals to the write control means only in the write mode responsive to the internal write pulse signal and for setting the write process signals to fixed potentials during a time other than the write mode.

  7. Estimating synchronization signal phase

    NASA Astrophysics Data System (ADS)

    Lyons, Robert G.; Lord, John D.

    2015-03-01

    To read a watermark from printed images requires that the watermarking system read correctly after affine distortions. One way to recover from affine distortions is to add a synchronization signal in the Fourier frequency domain and use this synchronization signal to estimate the applied affine distortion. Using the Fourier Magnitudes one can estimate the linear portion of the affine distortion. To estimate the translation one must first estimate the phase of the synchronization signal and then use phase correlation to estimate the translation. In this paper we provide a new method to measure the phase of the synchronization signal using only the data from the complex Fourier domain. This data is used to compute the linear portion, so it is quite convenient to estimate the phase without further data manipulation. The phase estimation proposed in this paper is computationally simple and provides a significant computational advantage over previous methods while maintaining similar accuracy. In addition, the phase estimation formula gives a general way to interpolate images in the complex frequency domain.

  8. [Mechanism of the development of permanent estrus in rats after transplantation of the ovaries into a low temperature medium].

    PubMed

    Vunder, P A; Smetanina, M D

    1983-03-01

    Autotransplantation of the ovaries to the ears of adult rats induces permanent estrus following 5-7 days. Autotransplantation of the ovaries beneath the renal capsules makes the sexual cycle return to normal after the same period. Autotransplantation of the ovaries to the ears of infantile rats brings about pubertas precox followed by normal sexual cycle. Permanent estrus ensues only after 4 months. Transplantation of the ovaries from infantile rats to adult ones and vice versa has shown that age-related differences in the alterations seen in the sexual cycle in response to gonadal transplantation to the ears are caused by age-related differences in the recipients, precisely by those in the cyclic center. PMID:6681996

  9. Reproduction in free-ranging Propithecus verreauxi: estrus and the relationship between multiple partner matings and fertilization.

    PubMed

    Brockman, D K; Whitten, P L

    1996-05-01

    Female sifaka mate selectively with one or more resident and/or non-resident males during the breeding season. Various adaptive explanations have been advanced to explain why female primates mate with multiple males including that 1) females seek to confuse paternity and thereby forestall male infanticide and/or ensure male infant care or 2) females seek to ensure fertilization. Assessing the power of fertilization insurance to explain mating patterns in females requires information on the temporal relationship between mating and ovarian hormones. The hormonal correlates of reproduction and mating in free-ranging Propithecus verreauxi were investigated using excreted steroids as indices of reproductive state. Solid-phase extraction and radioimmunoassay techniques were used to measure unconjugated estradiol (E(2)) and progesterone (P(4)) in 485 desiccated fecal samples collected from five female sifaka before and during the breeding season at Beza Mahafaly, Madagascar. Results suggest that behavioral estrus was characterized by 10 to 15-day elevations in E(2); hormonal activity was observed to be similar to pseudo-estrus reported for other lemur species; apparent conception was associated with sustained P4 elevations beginning 1 to 3 days post-estrus with gestational phase elevations of E2 beginning 42 to 45 days post-conception; and mating with multiple partners appeared not to be a prerequisite to fertilization, as conception resulted from both monoandrous and polyandrous matings. These preliminary data suggest that fertilization insurance is not adequate to explain polyandrous mating in sifaka at Beza Mahafaly.

  10. Synchronization and hydrodynamic interactions

    NASA Astrophysics Data System (ADS)

    Powers, Thomas; Qian, Bian; Breuer, Kenneth

    2008-03-01

    Cilia and flagella commonly beat in a coordinated manner. Examples include the flagella that Volvox colonies use to move, the cilia that sweep foreign particles up out of the human airway, and the nodal cilia that set up the flow that determines the left-right axis in developing vertebrate embryos. In this talk we present an experimental study of how hydrodynamic interactions can lead to coordination in a simple idealized system: two nearby paddles driven with fixed torques in a highly viscous fluid. The paddles attain a synchronized state in which they rotate together with a phase difference of 90 degrees. We discuss how synchronization depends on system parameters and present numerical calculations using the method of regularized stokeslets.

  11. Alternative programs for synchronizing and resynchronizing ovulation in beef cattle.

    PubMed

    Bó, Gabriel A; de la Mata, José Javier; Baruselli, Pietro S; Menchaca, Alejo

    2016-07-01

    Fixed-time artificial insemination (FTAI) has been regarded as the most useful method to increase the number of cows inseminated in a given herd. The main treatments for FTAI in beef cattle are based on the use of progesterone-releasing devices and GnRH or estradiol to synchronize follicle wave emergence, with a mean pregnancy per AI (P/AI) around 50%. However, more recent protocols based on GnRH (named 5-day Co-Synch) or estradiol (named J-Synch) that reduce the period of progesterone device insertion and extend the period from device removal to FTAI have been reported to improve P/AI in beef cattle. Furthermore, treatments to resynchronize ovulation for a second FTAI in nonpregnant cows have provided the opportunity to do sequential inseminations and achieve high P/AI in a breeding season, reducing or even eliminating the need for clean-up bulls. In summary, FTAI protocols have facilitated the widespread application of AI in beef cattle, primarily by eliminating the necessity of estrus detection in beef herds. PMID:27180326

  12. Socially synchronized circadian oscillators

    PubMed Central

    Bloch, Guy; Herzog, Erik D.; Levine, Joel D.; Schwartz, William J.

    2013-01-01

    Daily rhythms of physiology and behaviour are governed by an endogenous timekeeping mechanism (a circadian ‘clock’). The alternation of environmental light and darkness synchronizes (entrains) these rhythms to the natural day–night cycle, and underlying mechanisms have been investigated using singly housed animals in the laboratory. But, most species ordinarily would not live out their lives in such seclusion; in their natural habitats, they interact with other individuals, and some live in colonies with highly developed social structures requiring temporal synchronization. Social cues may thus be critical to the adaptive function of the circadian system, but elucidating their role and the responsible mechanisms has proven elusive. Here, we highlight three model systems that are now being applied to understanding the biology of socially synchronized circadian oscillators: the fruitfly, with its powerful array of molecular genetic tools; the honeybee, with its complex natural society and clear division of labour; and, at a different level of biological organization, the rodent suprachiasmatic nucleus, site of the brain's circadian clock, with its network of mutually coupled single-cell oscillators. Analyses at the ‘group’ level of circadian organization will likely generate a more complex, but ultimately more comprehensive, view of clocks and rhythms and their contribution to fitness in nature. PMID:23825203

  13. Synchronization of Eukaryotic Flagella

    NASA Astrophysics Data System (ADS)

    Goldstein, Raymond E.

    2012-11-01

    From unicellular organisms as small as a few microns to the largest vertebrates on earth we find groups of beating flagella or cilia that exhibit striking spatio-temporal organization. This may take the form of precise frequency and phase locking as frequently found in the swimming of green algae, or beating with long-wavelength phase modulations known as metachronal waves, seen in ciliates and in our respiratory systems. The remarkable similarity in the underlying molecular structure of flagella across the whole eukaryotic world leads naturally to the hypothesis that a similarly universal mechanism might be responsible for synchronization. Although this mechanism is poorly understood, one appealing hypothesis is that it results from hydrodynamic interactions between flagella. In this talk I will describe a synthesis of recent experimental and theoretical studies of this issue that have provided the strongest evidence to date for the hydrodynamic origin of flagellar synchronization. At the unicellular level this includes studies of the beating of the two flagella of the wild type unicellular alga Chlamydomonas reinhardtii in their native state and under conditions of regrowth following autotomy, and of the flagellar dominance mutant ptx1, which displays unusual anti-phase synchronization. Analysis of the related multicellular organism Volvox carteri shows it to be an ideal model organism for the study of metachronal waves. Supported by BBSRC, EPSRC, ERC, and The Wellcome Trust.

  14. Digital Synchronizer without Metastability

    NASA Technical Reports Server (NTRS)

    Simle, Robert M.; Cavazos, Jose A.

    2009-01-01

    A proposed design for a digital synchronizing circuit would eliminate metastability that plagues flip-flop circuits in digital input/output interfaces. This metastability is associated with sampling, by use of flip-flops, of an external signal that is asynchronous with a clock signal that drives the flip-flops: it is a temporary flip-flop failure that can occur when a rising or falling edge of an asynchronous signal occurs during the setup and/or hold time of a flip-flop. The proposed design calls for (1) use of a clock frequency greater than the frequency of the asynchronous signal, (2) use of flip-flop asynchronous preset or clear signals for the asynchronous input, (3) use of a clock asynchronous recovery delay with pulse width discriminator, and (4) tying the data inputs to constant logic levels to obtain (5) two half-rate synchronous partial signals - one for the falling and one for the rising edge. Inasmuch as the flip-flop data inputs would be permanently tied to constant logic levels, setup and hold times would not be violated. The half-rate partial signals would be recombined to construct a signal that would replicate the original asynchronous signal at its original rate but would be synchronous with the clock signal.

  15. Emergency Response Synchronization Matrix

    1999-06-01

    An emergency response to a disaster is complex, requiring the rapid integration, coordination, and synchronization of multiple levels of governmental and non-governmental organizations from numerous jurisdictions into a unified community response. For example, a community’s response actions to a fixed site hazardous materials incident could occur in an area extending from an on-site storage location to points 25 or more miles away. Response actions are directed and controlled by local governments and agencies situated withinmore » the response area, as well as by state and federal operaticns centers quite removed from the area of impact. Time is critical and the protective action decision-making process is greatly compressed. The response community must carefully plan and coordinate response operations in order to have confidence that they will be effectively implemented when faced with the potentially catastrophic nature of such releases. A graphical depiction of the entire response process via an emergency response synchronization matrix is an effective tool in optimizing the planning, exercising, and implementation of emergency plans. This system—based approach to emergency planning depicts how a community organizes its response tasks across space and time in relation to hazard actions. It provides the opportunity to make real—time adjustments as necessary for maximizing the often limited resources in protecting area residents. A response must involve the entire community and must not be limited by individual jurisdictions and organizations acting on their own without coordination, integration, and synchronization.« less

  16. Estrous synchronization strategies to optimize beef heifer reproductive performance after reproductive tract scoring.

    PubMed

    Kasimanickam, Ramanathan K; Whittier, William D; Hall, John B; Kastelic, John P

    2016-08-01

    Three experiments comparing four estrous synchronization protocols were conducted to determine estrous expression rate and artificial insemination pregnancy rate (AI-PR) in heifers with a range (1-5) of reproductive tract scores (RTSs). At enrollment (Day 0), 1783 Angus cross beef heifers from six locations were given body condition score and RTS. The four protocols were: (1) HRTS-DPGF group-heifers with RTS 5 received prostaglandin F2α (PGF; Dinoprost 25 mg; im) on Days 0 and 14; (2) HRTS-CIDR-PGF group-heifers with RTS 5 received a CIDR (1.3-g progesterone) insert on Day 7, followed by CIDR removal and PGF on Day 14; (3) LRTS-CIDR-PGF group-heifers with RTS 4 or less received a CIDR insert on Day 7, followed by CIDR removal and PGF on Day 14; and (4) HRTS-Select-Synch group-heifers with RTS 5 received 100 μg of gonadorelin diacetate tetrahydrate (gonadotropin releasing homone; im) on Day 7 and PGF on Day 14. In all groups, heifers observed in estrus were artificially inseminated (within 120 hours after PGF) using the AM-PM rule. In Experiment 1, estrus expression rates were 82.2% (282/343) and 88.5% (184/208) for HRTS-DPGF and LRTS-CIDR-PGF, respectively (P < 0.05), whereas AI-PR were 51.3% (176/343) and 59.1% (123/208; P < 0.1). In Experiment 2, estrus expression rates were 79.6 (168/211), 86.9 (186/214) and 84.2% (176/209) for HRTS-DPGF, HRTS-CIDR-PGF, and LRTS-CIDR-PGF groups (P > 0.1) and AI-PR were 52.1 (110/211), 60.3 (129/214), and 58.4% (122/209; P > 0.05). In Experiment 3, estrus expression rates were 77.5 (131/169), 85.5 (142/166), and 83.3% (219/263) for HRTS-DPGF, HRTS-Select-Synch and LRTS-CIDR-PGF (P > 0.05) and AI-PR were 53.3 (90/169), 60.2 (100/166), and 58.6% (154/263; P > 0.1). Overall, estrus expression rates for HRTS-DPGF, HRTS-Select-Synch, LRTS-CIDR-PGF, and HRTS-CIDR-PGF groups were 80.4 (581/723), 85.5 (142/166), 85.1 (579/680), and 86.9% (186/214), respectively; higher for heifers in LRTS-CIDR-PGF and HRTS-CIDR-PGF groups

  17. Enhancing bull sexual behavior using estrus-specific molecules identified in cow urine.

    PubMed

    Le Danvic, Chrystelle; Gérard, Olivier; Sellem, Eli; Ponsart, Claire; Chemineau, Philippe; Humblot, Patrice; Nagnan-Le Meillour, Patricia

    2015-06-01

    Deficiencies in bull mating behavior have implications for bovine artificial insemination activities. The aim of this study was to identify the compounds present in fluids emitted by cows during estrus, which could enhance bull libido. Chemical analysis of urine samples from cows led to the characterization of molecules varying specifically at the preestrous and estrous stages. The synthetic counterpart molecules (1,2-dichloroethylene, squalene, coumarin, 2-butanone, oleic acid) were used to investigate the biological effects on male sexual behavior and sperm production. When presented to males, 2-butanone and oleic acid synthetic molecules significantly lowered mounting reaction time and ejaculation time (-33% and 21% after 2-butanone inhalation, respectively, P < 0.05). The "squalene +1,2-dichloroethylene" combination induced a 9% increase of sperm quantity (P < 0.05). This study suggests that the identified estrous-specific molecules could be part of the chemical signals involved in male and female mating behavior and may be used for a wide range of applications. The identification of these molecules may have implications for the cattle breeding industry.

  18. Enhancing bull sexual behavior using estrus-specific molecules identified in cow urine.

    PubMed

    Le Danvic, Chrystelle; Gérard, Olivier; Sellem, Eli; Ponsart, Claire; Chemineau, Philippe; Humblot, Patrice; Nagnan-Le Meillour, Patricia

    2015-06-01

    Deficiencies in bull mating behavior have implications for bovine artificial insemination activities. The aim of this study was to identify the compounds present in fluids emitted by cows during estrus, which could enhance bull libido. Chemical analysis of urine samples from cows led to the characterization of molecules varying specifically at the preestrous and estrous stages. The synthetic counterpart molecules (1,2-dichloroethylene, squalene, coumarin, 2-butanone, oleic acid) were used to investigate the biological effects on male sexual behavior and sperm production. When presented to males, 2-butanone and oleic acid synthetic molecules significantly lowered mounting reaction time and ejaculation time (-33% and 21% after 2-butanone inhalation, respectively, P < 0.05). The "squalene +1,2-dichloroethylene" combination induced a 9% increase of sperm quantity (P < 0.05). This study suggests that the identified estrous-specific molecules could be part of the chemical signals involved in male and female mating behavior and may be used for a wide range of applications. The identification of these molecules may have implications for the cattle breeding industry. PMID:25817331

  19. Amygdala Kindling Alters Estrus Cycle and Ovarian Morphology in the Rat.

    PubMed

    Pan, Juan; Zhang, Lingwu; Wang, Feng; Liu, Dan; Li, P Andy; Sun, Tao

    2013-11-01

    The objective of this study is to explore the effects of amygdala kindling on estrus cycle and ovarian morphology. Thirty-five female rats at the age of 8 weeks were randomly designated to electrode kindled, sham-kindled, and normal controls. Kindled rats were implanted with kindling electrodes in the left basolateral amygdala and kindled by brief suprathreshold stimulations with a bipolar electrode. Estrous cycles were daily monitored through vaginal smears. Electrographic and behavioral seizures were recorded and ovarian morphology was evaluated by light and electron microscopies. Our results showed that the kindled rats lost their ovarian periodicity displayed significant ovarian enlargement. H&E staining revealed increased number of growing follicles and total follicles, as well as polycysts in the ovaries of the kindled animals compared to sham and control animals. Ultrastructural study detected numerous apoptotic granulosa cells in growing follicles and thecal cell hyperplasia with secretary granules in the thecal cells in the kindled rats. The results suggest that amygdala kindling is a risk factor for the development of polycystic ovary syndrome.

  20. Amygdala Kindling Alters Estrus Cycle and Ovarian Morphology in the Rat

    PubMed Central

    Pan, Juan; Zhang, Lingwu; Wang, Feng; Liu, Dan

    2014-01-01

    The objective of this study is to explore the effects of amygdala kindling on estrus cycle and ovarian morphology. Thirty-five female rats at the age of 8 weeks were randomly designated to electrode kindled, sham-kindled, and normal controls. Kindled rats were implanted with kindling electrodes in the left basolateral amygdala and kindled by brief suprathreshold stimulations with a bipolar electrode. Estrous cycles were daily monitored through vaginal smears. Electrographic and behavioral seizures were recorded and ovarian morphology was evaluated by light and electron microscopies. Our results showed that the kindled rats lost their ovarian periodicity displayed significant ovarian enlargement. H&E staining revealed increased number of growing follicles and total follicles, as well as polycysts in the ovaries of the kindled animals compared to sham and control animals. Ultrastructural study detected numerous apoptotic granulosa cells in growing follicles and thecal cell hyperplasia with secretary granules in the thecal cells in the kindled rats. The results suggest that amygdala kindling is a risk factor for the development of polycystic ovary syndrome. PMID:25285307

  1. Amygdala Kindling Alters Estrus Cycle and Ovarian Morphology in the Rat.

    PubMed

    Pan, Juan; Zhang, Lingwu; Wang, Feng; Liu, Dan; Li, P Andy; Sun, Tao

    2013-11-01

    The objective of this study is to explore the effects of amygdala kindling on estrus cycle and ovarian morphology. Thirty-five female rats at the age of 8 weeks were randomly designated to electrode kindled, sham-kindled, and normal controls. Kindled rats were implanted with kindling electrodes in the left basolateral amygdala and kindled by brief suprathreshold stimulations with a bipolar electrode. Estrous cycles were daily monitored through vaginal smears. Electrographic and behavioral seizures were recorded and ovarian morphology was evaluated by light and electron microscopies. Our results showed that the kindled rats lost their ovarian periodicity displayed significant ovarian enlargement. H&E staining revealed increased number of growing follicles and total follicles, as well as polycysts in the ovaries of the kindled animals compared to sham and control animals. Ultrastructural study detected numerous apoptotic granulosa cells in growing follicles and thecal cell hyperplasia with secretary granules in the thecal cells in the kindled rats. The results suggest that amygdala kindling is a risk factor for the development of polycystic ovary syndrome. PMID:25285307

  2. Expression of estrus modifies the gene expression profile in reproductive tissues on Day 19 of gestation in beef cows.

    PubMed

    Davoodi, S; Cooke, R F; Fernandes, A C C; Cappellozza, B I; Vasconcelos, J L M; Cerri, R L A

    2016-03-01

    The aim of this study was to test the effect of expression of estrus at artificial insemination (AI) on endometrium, conceptus, and CL gene expression of beef cows. Thirty-six multiparous nonlactating Nelore cows were enrolled on an estradiol- and progesterone (P4)-based timed AI protocol (AI = Day 0) and then slaughtered for the endometrium, CL, and conceptus collection on Day 19. The animals were retrospectively grouped on the basis of cows that (1) showed signs of estrus near AI (n = 19; estrus) and (2) did not show any signs of estrus (n = 17; nonestrus). Body condition score, blood sampling, and ultrasound examination were performed on Days 0, 7, and 18 of the experiment followed by messenger RNA extraction and quantitative reverse transcription polymerase chain reaction analysis of 58 target genes. Data were checked for normality and analyzed by ANOVA for repeated measures using proc GLM, MIXED, and UNIVARIATE of SAS. Only pregnant cows were included in the analyses (n = 12; nonestrus, n = 11). Estrous expression had no correlation with parameters such as body condition score, preovulatory follicle and CL diameter, P4 concentration in plasma on Days 7 and 18 after AI, and interferon-tau concentration in the uterine flushing (P > 0.15); however, a significant increase was observed in conceptus size from cows that expressed estrus (P = 0.02; 38.3 ± 2.8 vs. 28.2 ± 2.9 mm). The majority of transcripts affected by estrous expression in the endometrium belong to the immune system and adhesion molecule family (MX1, MX2, MYL12A, MMP19, CXCL10, IGLL1, and SLPI; P ≤ 0.05), as well as those related with prostaglandin synthesis (OTR and COX-2; P ≤ 0.05). Genes related to apoptosis, P4 synthesis, and prostaglandin receptor were downregulated (CYP11A, BAX, and FPr; P < 0.05) in the CL tissue of cows that expressed estrus. In addition, four genes were identified as differentially expressed in the 19-day-old conceptus from cows that expressed estrus (ISG15, PLAU, BMP15

  3. Breeding capacity, behavior and fertility of bulls with Brahman genetic influence during synchronized breeding of beef females.

    PubMed

    Williams, G L

    1988-07-01

    The objective of this experiment was to evaluate the feasibility of using bulls of Brahman-derived breeds for synchronized breeding of females treated with Syncro-Mate-B (SMB). Suckled, postpartum cows (n = 261) and virgin heifers (n = 227) were given the standard SMB treatment. Calves were removed from cows for 48 h beginning at implant removal, and individual bulls were placed in pens with 15 to 20 females (x = 1:15.7 ) for 48 h beginning at implant removal. Bulls (n = 31) were 18 to 36 mo of age and had scored satisfactorily on a breeding soundness evaluation (BSE). The mean +/- SEM percentage of females in estrus, percentage of estrous females serviced and percentage of total females serviced were 77.2 +/- 2.4, 72.9 +/- 2.9 and 55.7 +/- 3%, respectively. Total average services per bull was 23.6 +/- 1.6; however, average number of individuals serviced was only 8.6 +/- 0.42. Mean +/- SEM percentage of females conceiving of those serviced, percentage conceiving of those in estrus and percentage conceiving of total females available were 57.3 +/- 3.7, 40.6 +/- 2.6 and 32.6 +/- 2.5%, respectively. Mean BSE scores of eight Simbrah bulls tested immediately before and 5 d after synchronized breeding did not differ (P > 0.05). These data suggest that the conception rate of Brahman-influenced bulls servicing SMB-synchronized cows is within the normal range. However, the total number of individual females serviced and the total pregnancy rate under the protocol employed was low. This occurred because all estrous females were not inseminated, and some bulls exhibited unpredicted low fertility.

  4. Breeding capacity, behavior and fertility of bulls with Brahman genetic influence during synchronized breeding of beef females.

    PubMed

    Williams, G L

    1988-07-01

    The objective of this experiment was to evaluate the feasibility of using bulls of Brahman-derived breeds for synchronized breeding of females treated with Syncro-Mate-B (SMB). Suckled, postpartum cows (n = 261) and virgin heifers (n = 227) were given the standard SMB treatment. Calves were removed from cows for 48 h beginning at implant removal, and individual bulls were placed in pens with 15 to 20 females (x = 1:15.7 ) for 48 h beginning at implant removal. Bulls (n = 31) were 18 to 36 mo of age and had scored satisfactorily on a breeding soundness evaluation (BSE). The mean +/- SEM percentage of females in estrus, percentage of estrous females serviced and percentage of total females serviced were 77.2 +/- 2.4, 72.9 +/- 2.9 and 55.7 +/- 3%, respectively. Total average services per bull was 23.6 +/- 1.6; however, average number of individuals serviced was only 8.6 +/- 0.42. Mean +/- SEM percentage of females conceiving of those serviced, percentage conceiving of those in estrus and percentage conceiving of total females available were 57.3 +/- 3.7, 40.6 +/- 2.6 and 32.6 +/- 2.5%, respectively. Mean BSE scores of eight Simbrah bulls tested immediately before and 5 d after synchronized breeding did not differ (P > 0.05). These data suggest that the conception rate of Brahman-influenced bulls servicing SMB-synchronized cows is within the normal range. However, the total number of individual females serviced and the total pregnancy rate under the protocol employed was low. This occurred because all estrous females were not inseminated, and some bulls exhibited unpredicted low fertility. PMID:16726447

  5. Psychic energy and synchronicity.

    PubMed

    Zabriskie, Beverley

    2014-04-01

    Given Jung's interest in physics' formulations of psychic energy and the concept of time, overlaps and convergences in the themes addressed in analytical psychology and in quantum physics are to be expected. These are informed by the active intersections between the matter of mind and mindfulness re matter. In 1911, Jung initiated dinners with Einstein. Jung's definition of libido in the pivotal 1912 Fordham Lectures reveals the influence of these conversations. Twenty years later, a significant period in physics, Wolfgang Pauli contacted Jung. Their collaboration led to the theory of synchronicity.

  6. Sun synchronous solar refrigeration

    NASA Astrophysics Data System (ADS)

    The primary goal of this project was to prototype a complete Sun Synchronous Solar Powered Refrigerator. The key element to the technology is the development of the hermetic motor compressor assembly. The prototype was to be developed to either the stage where Polar Products could receive additional venture capital or to the point whereby Polar could use their own capital to manufacture the systems. Our goal was to construct a prototype which would be the next step to a proven and market ready product. To demonstrate the technology under laboratory conditions was a very minimal goal.

  7. Single fixed-time artificial insemination in gilts and weaned sows using pLH at estrus onset administered through vulvar submucosal route.

    PubMed

    Ulguim, R R; Fontana, D L; Bernardi, M L; Wentz, I; Bortolozzo, F P

    2016-09-01

    This study evaluated the use of a single fixed-time artificial insemination (FTAI) in gilts and weaned sows using 2.5 mg of porcine luteinizing hormone (pLH) administered through vulvar submucosal route, at the onset of estrus. In experiment 1 (Exp.1), 318 pubertal gilts were assigned to two groups: control-G-no hormonal application and artificial inseminations (AIs) at 12, 36, and 60 hours after the onset of estrus if they were still in standing estrus; and FTAI-G-use of pLH at the onset of estrus and a single FTAI 12 hours later. In experiment 2 (Exp. 2), 309 weaned sows were assigned to three groups: Control-S-no hormone application and AIs at 0, 24, and 48 hours after the onset of estrus if they were still in standing estrus; FTAI-NH-no hormone application and a single FTAI at 24 hours after the onset of estrus, and FTAI-pLH-use of pLH at the onset of estrus and a single FTAI 24 hours later. Transabdominal real time B-mode ultrasonography was performed to determine whether the insemination had been performed within 24 hours before ovulation, considered as the optimal interval. In Exp. 1, ultrasound evaluation (12-hour intervals) was carried out to determine the interval between the onset of estrus and ovulation. In both experiments, 2 × 10(9) sperm cells in 80 mL were used to perform cervical and postcervical deposition of semen in gilts and sows, respectively. Compared with control-G, FTAI-G gilts had shorter (P < 0.05) duration of estrus (57.7 vs. 61.2 hours) and interval between the onset of estrus and ovulation (36.3 vs. 42.3 hours). The adjusted farrowing rate (AFR) was lower (P < 0.05) in FTAI-G (86.0%) compared with control-G (93.5%), but total piglets born (TPB) did not differ between these groups (12.3 vs. 12.5 piglets). Within the FTAI-G group, the AFR was lower (P < 0.05) in the presence (50.0%) than in the absence (94.9%) of semen backflow during AI. Also in the FTAI-G group, the insemination outside the optimal interval reduced (P

  8. Delayed onset of persistent estrus in aged rats raised from parathyroidectomized mothers.

    PubMed

    Fujii, T; Yamamoto, N

    1983-01-01

    Descendants of rats possessing lower responsiveness to the removal of the parathyroid gland [4] were examined for the aging process of the hypothalamic-pituitary-ovarian axis. The first generation rats of these descendants were born to mothers parathyroidectomized (Px) on the fifth day of gestation and subsequent generation rats were developed by brother-sister mating without any special treatment. More than 50% of the eighth to tenth generation (F8-F10) offsprings of the Px-rats showed regular 4-day estrous cycles at 15-16 months of age, while nearly 80% of normal F8-F10 rats developed persistent estrus at 13-14 months of age. In 14-15 month-old Px-offspring rats the LH and FSH surges occurred at 1630-1730 h of proestrus to a similar extent as those shown in 3-4 month-old normal rats. The release of LH and FSH following a single injection of luteinizing hormone-releasing hormone (LHRH) in 13 month-old Px-offspring rats was nearly normal, reaching a maximal level at 15 min as in young adult rats. In 13 month-old normal rats, serum LH measured after an injection of LHRH increased progressively until 60 min. The ovaries of the Px-offspring rats were heavier than those of age-matched normal rats and included well-developed corpora lutea and follicles in several sizes. The results suggest a delay in the aging process of the hypothalamic-pituitary-ovarian axis of the Px-offspring rats.

  9. Digitized synchronous demodulator

    NASA Technical Reports Server (NTRS)

    Woodhouse, Christopher E. (Inventor)

    1990-01-01

    A digitized synchronous demodulator is constructed entirely of digital components including timing logic, an accumulator, and means to digitally filter the digital output signal. Indirectly, it accepts, at its input, periodic analog signals which are converted to digital signals by traditional analog-to-digital conversion techniques. Broadly, the input digital signals are summed to one of two registers within an accumulator, based on the phase of the input signal and medicated by timing logic. At the end of a predetermined number of cycles of the inputted periodic signals, the contents of the register that accumulated samples from the negative half cycle is subtracted from the accumulated samples from the positive half cycle. The resulting difference is an accurate measurement of the narrow band amplitude of the periodic input signal during the measurement period. This measurement will not include error sources encountered in prior art synchronous demodulators using analog techniques such as offsets, charge injection errors, temperature drift, switching transients, settling time, analog to digital converter missing code, and linearity errors.

  10. Synchronized dynamic dose reconstruction

    SciTech Connect

    Litzenberg, Dale W.; Hadley, Scott W.; Tyagi, Neelam; Balter, James M.; Ten Haken, Randall K.; Chetty, Indrin J.

    2007-01-15

    Variations in target volume position between and during treatment fractions can lead to measurable differences in the dose distribution delivered to each patient. Current methods to estimate the ongoing cumulative delivered dose distribution make idealized assumptions about individual patient motion based on average motions observed in a population of patients. In the delivery of intensity modulated radiation therapy (IMRT) with a multi-leaf collimator (MLC), errors are introduced in both the implementation and delivery processes. In addition, target motion and MLC motion can lead to dosimetric errors from interplay effects. All of these effects may be of clinical importance. Here we present a method to compute delivered dose distributions for each treatment beam and fraction, which explicitly incorporates synchronized real-time patient motion data and real-time fluence and machine configuration data. This synchronized dynamic dose reconstruction method properly accounts for the two primary classes of errors that arise from delivering IMRT with an MLC: (a) Interplay errors between target volume motion and MLC motion, and (b) Implementation errors, such as dropped segments, dose over/under shoot, faulty leaf motors, tongue-and-groove effect, rounded leaf ends, and communications delays. These reconstructed dose fractions can then be combined to produce high-quality determinations of the dose distribution actually received to date, from which individualized adaptive treatment strategies can be determined.

  11. Synchronization Dynamics in Complex Networks

    NASA Astrophysics Data System (ADS)

    Zhou, Changsong; Zemanová, Lucia; Kurths, Jürgen

    Previous chapters have discussed tools from graph theory and their contribution to our understanding of the structural organization of mammalian brains and its functional implications. The brain functions are mediated by complicated dynamical processes which arise from the underlying complex neural networks, and synchronization has been proposed as an important mechanism for neural information processing. In this chapter, we discuss synchronization dynamics on complex networks. We first present a general theory and tools to characterize the relationship of some structural measures of networks to their synchronizability (the ability of the networks to achieve complete synchronization) and to the organization of effective synchronization patterns on the networks. Then, we study synchronization in a realistic network of cat cortical connectivity by modeling the nodes (which are cortical areas composed of large ensembles of neurons) by a neural mass model or a subnetwork of interacting neurons. We show that if the dynamics is characterized by well-defined oscillations (neural mass model and subnetworks with strong couplings), the synchronization patterns can be understood by the general principles discussed in the first part of the chapter. With weak couplings, the model with subnetworks displays biologically plausible dynamics and the synchronization pattern reveals a hierarchically clustered organization in the network structure. Thus, the study of synchronization of complex networks can provide insights into the relationship between network topology and functional organization of complex brain networks.

  12. Robust Sliding Window Synchronizer Developed

    NASA Technical Reports Server (NTRS)

    Chun, Kue S.; Xiong, Fuqin; Pinchak, Stanley

    2004-01-01

    The development of an advanced robust timing synchronization scheme is crucial for the support of two NASA programs--Advanced Air Transportation Technologies and Aviation Safety. A mobile aeronautical channel is a dynamic channel where various adverse effects--such as Doppler shift, multipath fading, and shadowing due to precipitation, landscape, foliage, and buildings--cause the loss of symbol timing synchronization.

  13. RAM-Based frame synchronizer

    NASA Technical Reports Server (NTRS)

    Niswander, J. K.; Stattel, R. J.

    1980-01-01

    Frame synchronizer for serial telemetry is rapidly reconfigured for changing formats. Synchronizer generates signals marking data-word boundaries, beginning of each frame, and beginning of each paragraph. Also derived are search, check, and lock status signals. Existing unit is assembled from standard random-access memory elements and MOS and low-power-Schottky logic.

  14. Digital synchronization and communication techniques

    NASA Technical Reports Server (NTRS)

    Lindsey, William C.

    1992-01-01

    Information on digital synchronization and communication techniques is given in viewgraph form. Topics covered include phase shift keying, modems, characteristics of open loop digital synchronizers, an open loop phase and frequency estimator, and a digital receiver structure using an open loop estimator in a decision directed architecture.

  15. Chua's Circuit: Control and Synchronization

    NASA Astrophysics Data System (ADS)

    Irimiciuc, Stefan-Andrei; Vasilovici, Ovidiu; Dimitriu, Dan-Gheorghe

    Chaos-based data encryption is one of the most reliable methods used in secure communications. This implies a good control of a chaotic system and a good synchronization between the involved systems. Here, experimental results are shown on the control and synchronization of Chua's circuits. The control of the chaotic circuit was achieved by using the switching method. The influence of the control signal characteristics (amplitude, frequency and shape) on the system's states was also investigated. The synchronization of two similar chaotic circuits was studied, emphasizing the importance of the chaotic state characteristics of the Master system in respect to those of Slave system. It was shown that the synchronization does not depend on the chaotic state type, neither on the dimension (x, y or z) used for synchronization.

  16. Twin engine synchronizer

    SciTech Connect

    Kobus, J.R.

    1988-05-03

    This patent describes an apparatus for synchronizing the speeds of two engines, each having its own throttle level connected by an associated cable to a respective hand throttle lever, comprising moving means carried by the throttle lever of one of the engines for moving the throttle lever of the one engine independently of its associated cable and its respective hand throttle lever to increase or decrease the speed of the one engine until the speed of the one engine matches the speed of the other engine. The moving means moves the throttle lever of the one engine without moving its associated cable or its respective hand throttle lever, and actuating means mounted remote from the throttle lever of the one engine for actuating the moving means.

  17. Synchronization in neural nets

    NASA Technical Reports Server (NTRS)

    Vidal, Jacques J.; Haggerty, John

    1988-01-01

    The paper presents an artificial neural network concept (the Synchronizable Oscillator Networks) where the instants of individual firings in the form of point processes constitute the only form of information transmitted between joining neurons. In the model, neurons fire spontaneously and regularly in the absence of perturbation. When interaction is present, the scheduled firings are advanced or delayed by the firing of neighboring neurons. Networks of such neurons become global oscillators which exhibit multiple synchronizing attractors. From arbitrary initial states, energy minimization learning procedures can make the network converge to oscillatory modes that satisfy multi-dimensional constraints. Such networks can directly represent routing and scheduling problems that consist of ordering sequences of events.

  18. Nutritional recommendations for synchronized swimming.

    PubMed

    Robertson, Sherry; Benardot, Dan; Mountjoy, Margo

    2014-08-01

    The sport of synchronized swimming is unique, because it combines speed, power, and endurance with precise synchronized movements and high-risk acrobatic maneuvers. Athletes must train and compete while spending a great amount of time underwater, upside down, and without the luxury of easily available oxygen. This review assesses the scientific evidence with respect to the physiological demands, energy expenditure, and body composition in these athletes. The role of appropriate energy requirements and guidelines for carbohydrate, protein, fat, and micronutrients for elite synchronized swimmers are reviewed. Because of the aesthetic nature of the sport, which prioritizes leanness, the risks of energy and macronutrient deficiencies are of significant concern. Relative Energy Deficiency in Sport and disordered eating/eating disorders are also of concern for these female athletes. An approach to the healthy management of body composition in synchronized swimming is outlined. Synchronized swimmers should be encouraged to consume a well-balanced diet with sufficient energy to meet demands and to time the intake of carbohydrate, protein, and fat to optimize performance and body composition. Micronutrients of concern for this female athlete population include iron, calcium, and vitamin D. This article reviews the physiological demands of synchronized swimming and makes nutritional recommendations for recovery, training, and competition to help optimize athletic performance and to reduce risks for weight-related medical issues that are of particular concern for elite synchronized swimmers. PMID:24667278

  19. Synchronization in growing heterogeneous media

    NASA Astrophysics Data System (ADS)

    Chen, W.; Cheng, S. C.; Avalos, E.; Drugova, O.; Osipov, G.; Lai, Pik-Yin; Chan, C. K.

    2009-04-01

    Synchronization of heterogeneous systems that consist of oscillatory and passive elements are studied in cardiac myocytes/fibroblasts co-cultures. It is found that beating clusters of cardiac myocytes surrounded by fibroblasts will be formed. The beatings of the cardiac myocyte clusters are not correlated at early times, but get synchronized as the cultures mature. This synchronization can be understood by a Kuramoto model with a time-increasing coupling strength. Our findings show that the growth of the coupling strength between clusters is linear, while the overall wave dynamics of the system is controlled by the passive fibroblast in the system which presumably is growing exponentially.

  20. Time synchronized video systems

    NASA Technical Reports Server (NTRS)

    Burnett, Ron

    1994-01-01

    The idea of synchronizing multiple video recordings to some type of 'range' time has been tried to varying degrees of success in the past. Combining this requirement with existing time code standards (SMPTE) and the new innovations in desktop multimedia however, have afforded an opportunity to increase the flexibility and usefulness of such efforts without adding costs over the traditional data recording and reduction systems. The concept described can use IRIG, GPS or a battery backed internal clock as the master time source. By converting that time source to Vertical Interval Time Code or Longitudinal Time Code, both in accordance with the SMPTE standards, the user will obtain a tape that contains machine/computer readable time code suitable for use with editing equipment that is available off-the-shelf. Accuracy on playback is then determined by the playback system chosen by the user. Accuracies of +/- 2 frames are common among inexpensive systems and complete frame accuracy is more a matter of the users' budget than the capability of the recording system.

  1. Noncoherent Symbol Synchronization Techniques

    NASA Technical Reports Server (NTRS)

    Simon, Marvin

    2005-01-01

    Traditional methods for establishing symbol synchronization (sync) in digital communication receivers assume that carrier sync has already been established, i.e., the problem is addressed at the baseband level assuming that a 'perfect' estimate of carrier phase is available. We refer to this approach as coherent symbol sync. Since, for NRZ signaling, a suppressed carrier sync loop such as an I-Q Costas loop includes integrate-and-dump (I and D) filters in its in-phase (1) and quadrature (Q) arms, the traditional approach is to first track the carrier in the absence of symbol sync information, then feed back the symbol sync estimate to these filters, and then iterate between the two to a desirable operating level In this paper, we revisit the symbol sync problem by examining methods for obtaining such sync in the absence of carrier phase information, i.e., so-called noncoherent symbol sync loops. We compare the performance of these loops with that of a well-known coherent symbol sync loop and examine the conditions under which one is preferable over the other.

  2. Synchronization by small time delays

    NASA Astrophysics Data System (ADS)

    Pruessner, G.; Cheang, S.; Jensen, H. J.

    2015-02-01

    Synchronization is a phenomenon observed in all of the living and in much of the non-living world, for example in the heart beat, Huygens' clocks, the flashing of fireflies and the clapping of audiences. Depending on the number of degrees of freedom involved, different mathematical approaches have been used to describe it, most prominently integrate-and-fire oscillators and the Kuramoto model of coupled oscillators. In the present work, we study a very simple and general system of smoothly evolving oscillators, which continue to interact even in the synchronized state. We find that under very general circumstances, synchronization generically occurs in the presence of a (small) time delay. Strikingly, the synchronization time is inversely proportional to the time delay.

  3. Synchronous identification of friendly targets

    SciTech Connect

    Telle, John M.; Roger, Stutz A.

    1998-01-01

    A synchronous communication targeting system for use in battle. The present invention includes a transceiver having a stabilizing oscillator, a synchronous amplifier and an omnidirectional receiver, all in electrical communication with each other. A remotely located beacon is attached to a blackbody radiation source and has an amplitude modulator in electrical communication with a optical source. The beacon's amplitude modulator is set so that the optical source transmits radiation frequency at approximately the same or lower amplitude than that of the blackbody radiation source to which the beacon is attached. The receiver from the transceiver is adapted to receive frequencies approximately at or below blackbody radiation signals and sends such signals to the synchronous amplifier. The synchronous amplifier then rectifies and amplifies those signals which correspond to the predetermined frequency to therefore identify whether the blackbody radiation source is friendly or not.

  4. Optimistic barrier synchronization. Contractor report

    SciTech Connect

    Nicol, D.M.

    1992-07-01

    Barrier synchronization is a fundamental operation in parallel computation. In many contexts, at the point a processor enters a barrier it knows that is has already processed all work required of it prior to the synchronization. This paper treats the alternative case, when a processor cannot enter a barrier with the assurance that it has already performed all necessary pre-synchronization computation. The proble marises when the number of pre-synchronization messages to be received by a processor is unknown, for example, in a parallel discrete simulation or any other computation that is largely driven by an unpredictable exchange of messages. The authors describe an optimistic O(log2P) barrier algorithm for such problems, study its performance on a large-scale parallel system, and consider extensions to general associative reductions, as well as associative parallel prefix computations.

  5. Engineering synchronization of chaotic oscillators

    SciTech Connect

    Padmanaban, E.; Dana, Syamal K.

    2011-04-19

    We propose a controller based coupling design for engineering synchronization in chaotic oscillators for unidirectional as well as bi-directional mode. In the synchronization regimes, it is possible to amplify/ attenuate a chaotic attractor with respect to other chaotic attractors. Numerical examples are presented for a Lorenz system, a Roessler oscillator, and a Sprott system. Physical implementation of the scheme is done in electronic circuit to design the controller for verification of the theory.

  6. Synchronous reactive programming in Ptolemy

    SciTech Connect

    Boulanger, F.; Vidal-Naquet, G.

    1996-12-31

    Synchronous reactive languages allow a high level deterministic description of reactive systems such as control-command systems. Their well defined mathematical semantics makes it possible to check formal properties on the control of a system. In previous work, we developed an object-oriented execution model for synchronous reactive modules. This model is implemented as a set of tools and a C++ class library, and allows us to use object-oriented methodologies and tools for the design of complex applications with both transformational and reactive parts. Among these design tools, the Ptolemy system stands as an object-oriented framework that supports various execution models, or {open_quotes}domains{close_quotes}. We are currently working on a translator from the output format of the Lustre and Esterel compilers to the Ptolemy language. Since no existing domain matches the reactive synchronous execution model, we also plan to develop a SEC (Synchronous Execution and Communication) domain. Such a domain will provide support for the execution of synchronous modules in Ptolemy. One of the most interesting features of Ptolemy is the communication between domains. Therefore we discuss the interface of the SEC domain to other domains to determine the meaning of communications between them. The main goal is to allow the use of synchronous reactive modules for the control of the behavior of data-flow or discrete event processes.

  7. Cardiorespiratory synchronization during Zen meditation.

    PubMed

    Cysarz, Dirk; Büssing, Arndt

    2005-09-01

    The impact of meditation on cardiorespiratory synchronization with respect to breathing oscillations and the modulations of heart rate induced by respiration (respiratory sinus arrhythmia, RSA) was investigated in this study. Four different exercises (spontaneous breathing, mental task, Zen meditation, and Kinhin meditation) were consecutively performed by nine subjects mainly without any experience in meditation. An electrocardiogram and a respiratory trace were recorded simultaneously. On this basis the degree of cardiorespiratory synchronization was quantified by a technique which has been adopted from the analysis of weakly coupled chaotic oscillators. Both types of meditation showed a high degree of synchronization, whereas heartbeat and respiration were hardly synchronized during spontaneous breathing. During the mental task exercise the extent of synchronization was slightly higher than during spontaneous breathing. These results were largely determined by the breathing frequency because the two types of meditation induce low breathing frequencies which led to a pronounced and in-phase RSA. During the meditation the low breathing frequencies led to a decrease in the high frequency of heart rate variability, whereas the low frequency and the extent of RSA increased. The heart rate primarily reflected the degree of physical effort. The high degree of cardiorespiratory synchronization during meditation in unexperienced meditators suggests that the physiological implications of meditation does not require prior experience in meditation.

  8. Reproductive outcomes of Alpine goats primed with progesterone and treated with human chorionic gonadotropin during the anestrus-to-estrus transition season.

    PubMed

    Alvarado-Espino, A S; Meza-Herrera, C A; Carrillo, E; González-Álvarez, V H; Guillen-Muñoz, J M; Ángel-García, O; Mellado, M; Véliz-Deras, F G

    2016-04-01

    This study aimed to determine the possible effects of a single injection of human chorionic gonadotropin (hCG) as a means for estrus induction in acyclic French-Alpine goats during the reproductive transition period at 25°N, 103°W. The potential effects of hCG upon ovarian function and reproductive performance of goats were also assessed. Multiparous acyclic French-Alpine goats (n = 39; 37.4 ± 8 .5 kg) were primed with 20mg progesterone (P4) 1 day prior to hCG administration. Thereafter, does were treated either with saline (hCG-0; n = 10), 50 (hCG-50; n = 9), 100 (hCG-100; n = 10), or 300 IU of hCG (hCG-300; n = 10). Ovarian structures and pregnancy were monitored by transrectal ultrasonography. In addition, after hCG application, goats were monitored twice daily (0800 and 1800 h) to detect estrus signs, with the use of aproned, sexually active bucks treated with testosterone. Goats were bred 12h after the onset of estrus. Two days after hCG administration, the number of large follicles was higher (P < 0.05) in the hCG-50 and hCG-300 groups (1.7 ± 0.1 and 1.8 ± 0.2, respectively) compared with the hCG-100 and hCG-0 groups (1.4 ± 0.2 and 1.1 ± 0.1, respectively). Although none of the hCG-0-goats depicted estrus, the estrus response from the hCG-50, hCG-100, and hCG-300 groups over the 7-d breeding period was 67%, 100%, and 90%, respectively (P > 0.05), being always accompanied by ovulation. Pregnancy rate (67, 100, and 70%), kidding rate (55%, 80%, and 70%), and litter size (1.6 ± 0.5, 1.5 ± 0.5, and 1.5 ± 0.5) for hCG-50, hCG-100, and hCG-300, respectively, did not differ among the hCG-treated does. Therefore, the combined use of P4-priming plus a 100-IU hCG injection is an effective protocol for inducing estrus in non-cycling Alpine goats during the anestrus-to-estrus transition period, which is of key importance for both goat producers and industrializers. PMID:26944772

  9. Estrus behavior, ovarian dynamics, and progesterone secretion in Criollo cattle during estrous cycles with two and three follicular waves.

    PubMed

    Quezada-Casasola, Andrés; Avendaño-Reyes, Leonel; Macías-Cruz, Ulises; Ramírez-Godínez, José Alejandro; Correa-Calderón, Abelardo

    2014-04-01

    In beef and dairy cattle, the number of follicular waves affects endocrine, ovarian, and behavioral events during a normal estrous cycle. However, in Mexican-native Criollo cattle, a shortly and recently domesticated breed, the association between wave patterns and follicular development has not been studied. The objective of this study was to evaluate the effect of number of follicular waves in an estrous cycle on development of anovulatory and ovulatory follicles, corpus luteum (CL) development and functionality, as well as estrual behavior in Criollo cows. Ovarian follicular activities of 22 cycling multiparous Criollo cows were recorded daily by transrectal ultrasound examinations during a complete estrous cycle. Additionally, blood samples were collected daily to determine serum progesterone concentrations. Only two- (n = 17, 77.3%) and three-wave follicular (n = 5, 22.7%) patterns were observed. Duration of estrus, length of estrous cycle, and length of follicular and luteal phases were similar (P > 0.05) between cycles of two and three waves. Two-wave cows ovulated earlier (P < 0.05) after detection of estrus than three-wave cows. Detected day and maximum diameter of first anovulatory follicle were not affected (P > 0.05) by number of waves. Growth rate of first dominant follicle was higher (P < 0.05) in three-wave cycles. Onset of regression of the first dominant follicle was earlier (P < 0.01) in cycles with three waves than in those with two waves. In two-wave cycles, ovulatory follicles were detected earlier (P < 0.01) and had lower (P < 0.01) growth rate than in three-wave cycles. Development (i.e., maximum diameter and volume) and functionality (minimum and maximum progesterone concentration) of CL were similar (P > 0.05) between two- and three-wave patterns. In conclusion, Criollo cows have two or three follicular waves per estrous cycle, which alters partially ovulatory follicle development and ovulation time after detection of estrus. Length of

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

    PubMed

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

    2009-12-01

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

  11. The period of the follicular phase during which the uterus of mares shows estrus-like echotexture influences the subsequent pregnancy rate.

    PubMed

    Mateu-Sánchez, S; Newcombe, J R; Garcés-Narro, C; Cuervo-Arango, J

    2016-10-01

    The interval from both spontaneous and prostaglandin (PGF)-induced luteolysis to ovulation is greatly variable in mares. Several reports have shown a positive association between the length of the interval from PGF treatment to ovulation (ITO) and the subsequent pregnancy rate (PR). However, it is not known whether this association also occurs in estrous cycles with spontaneous luteolysis. The main objective of this study was to determine the effect of the duration of estrus-like echotexture of the uterus during the follicular phase on the subsequent PR in both spontaneous and PGF-induced cycles. A total of 768 estrous cycles from 325 thoroughbred mares were analyzed (401 estruses were induced with exogenous PGF and 367 cycles were not treated with PGF). The following factors were taken into account to determine the effect on PR: age of the mare, stallion, year of breeding, month of season, reproductive status of the mare, use of PGF treatment, duration of follicular phase with estrus-like echotexture, interovulatory interval (IOI; in spontaneous cycles), and ITO (in PGF-induced cycles). The age of the mare (P = 0.017), mare status (P = 0.031), the ITO (P = 0.041), and the duration of the follicular phase with estrus-like echotexture (P < 0.001) influenced the PR. The PR increased with the duration of estrus and of endometrial edema in both PGF-induced and spontaneous cycles. The correlation between the duration of endometrial edema and the IOI and ITO was positive (r = 0.5) and significant (P < 0.05). PMID:27298152

  12. The period of the follicular phase during which the uterus of mares shows estrus-like echotexture influences the subsequent pregnancy rate.

    PubMed

    Mateu-Sánchez, S; Newcombe, J R; Garcés-Narro, C; Cuervo-Arango, J

    2016-10-01

    The interval from both spontaneous and prostaglandin (PGF)-induced luteolysis to ovulation is greatly variable in mares. Several reports have shown a positive association between the length of the interval from PGF treatment to ovulation (ITO) and the subsequent pregnancy rate (PR). However, it is not known whether this association also occurs in estrous cycles with spontaneous luteolysis. The main objective of this study was to determine the effect of the duration of estrus-like echotexture of the uterus during the follicular phase on the subsequent PR in both spontaneous and PGF-induced cycles. A total of 768 estrous cycles from 325 thoroughbred mares were analyzed (401 estruses were induced with exogenous PGF and 367 cycles were not treated with PGF). The following factors were taken into account to determine the effect on PR: age of the mare, stallion, year of breeding, month of season, reproductive status of the mare, use of PGF treatment, duration of follicular phase with estrus-like echotexture, interovulatory interval (IOI; in spontaneous cycles), and ITO (in PGF-induced cycles). The age of the mare (P = 0.017), mare status (P = 0.031), the ITO (P = 0.041), and the duration of the follicular phase with estrus-like echotexture (P < 0.001) influenced the PR. The PR increased with the duration of estrus and of endometrial edema in both PGF-induced and spontaneous cycles. The correlation between the duration of endometrial edema and the IOI and ITO was positive (r = 0.5) and significant (P < 0.05).

  13. Synchronization configurations of two coupled double pendula

    NASA Astrophysics Data System (ADS)

    Koluda, Piotr; Perlikowski, Przemyslaw; Czolczynski, Krzysztof; Kapitaniak, Tomasz

    2014-04-01

    We consider the synchronization of two self-excited double pendula hanging from a horizontal beam which can roll on the parallel surface. We show that such pendula can obtain four different robust synchronous configurations. Our approximate analytical analysis allows to derive the synchronization conditions and explains the observed types of synchronizations. We consider the energy balance in the system and show how the energy is transferred between the pendula via the oscillating beam allowing the pendula' synchronization.

  14. Noncoherent DTTLs for Symbol Synchronization

    NASA Technical Reports Server (NTRS)

    Simon, Marvin; Tkacenko, Andre

    2007-01-01

    Noncoherent data-transition tracking loops (DTTLs) have been proposed for use as symbol synchronizers in digital communication receivers. [Communication- receiver subsystems that can perform their assigned functions in the absence of synchronization with the phases of their carrier signals ( carrier synchronization ) are denoted by the term noncoherent, while receiver subsystems that cannot function without carrier synchronization are said to be coherent. ] The proposal applies, more specifically, to receivers of binary phase-shift-keying (BPSK) signals generated by directly phase-modulating binary non-return-to-zero (NRZ) data streams onto carrier signals having known frequencies but unknown phases. The proposed noncoherent DTTLs would be modified versions of traditional DTTLs, which are coherent. The symbol-synchronization problem is essentially the problem of recovering symbol timing from a received signal. In the traditional, coherent approach to symbol synchronization, it is necessary to establish carrier synchronization in order to recover symbol timing. A traditional DTTL effects an iterative process in which it first generates an estimate of the carrier phase in the absence of symbol-synchronization information, then uses the carrier-phase estimate to obtain an estimate of the symbol-synchronization information, then feeds the symbol-synchronization estimate back to the carrier-phase-estimation subprocess. In a noncoherent symbol-synchronization process, there is no need for carrier synchronization and, hence, no need for iteration between carrier-synchronization and symbol- synchronization subprocesses. The proposed noncoherent symbolsynchronization process is justified theoretically by a mathematical derivation that starts from a maximum a posteriori (MAP) method of estimation of symbol timing utilized in traditional, coherent DTTLs. In that MAP method, one chooses the value of a variable of interest (in this case, the offset in the estimated symbol

  15. How Synchronization Protects from Noise

    PubMed Central

    Tabareau, Nicolas; Slotine, Jean-Jacques; Pham, Quang-Cuong

    2010-01-01

    The functional role of synchronization has attracted much interest and debate: in particular, synchronization may allow distant sites in the brain to communicate and cooperate with each other, and therefore may play a role in temporal binding, in attention or in sensory-motor integration mechanisms. In this article, we study another role for synchronization: the so-called “collective enhancement of precision”. We argue, in a full nonlinear dynamical context, that synchronization may help protect interconnected neurons from the influence of random perturbations—intrinsic neuronal noise—which affect all neurons in the nervous system. More precisely, our main contribution is a mathematical proof that, under specific, quantified conditions, the impact of noise on individual interconnected systems and on their spatial mean can essentially be cancelled through synchronization. This property then allows reliable computations to be carried out even in the presence of significant noise (as experimentally found e.g., in retinal ganglion cells in primates). This in turn is key to obtaining meaningful downstream signals, whether in terms of precisely-timed interaction (temporal coding), population coding, or frequency coding. Similar concepts may be applicable to questions of noise and variability in systems biology. PMID:20090826

  16. Bodily synchronization underlying joke telling

    PubMed Central

    Schmidt, R. C.; Nie, Lin; Franco, Alison; Richardson, Michael J.

    2014-01-01

    Advances in video and time series analysis have greatly enhanced our ability to study the bodily synchronization that occurs in natural interactions. Past research has demonstrated that the behavioral synchronization involved in social interactions is similar to dynamical synchronization found generically in nature. The present study investigated how the bodily synchronization in a joke telling task is spread across different nested temporal scales. Pairs of participants enacted knock–knock jokes and times series of their bodily activity were recorded. Coherence and relative phase analyses were used to evaluate the synchronization of bodily rhythms for the whole trial as well as at the subsidiary time scales of the whole joke, the setup of the punch line, the two-person exchange and the utterance. The analyses revealed greater than chance entrainment of the joke teller’s and joke responder’s movements at all time scales and that the relative phasing of the teller’s movements led those of the responder at the longer time scales. Moreover, this entrainment was greater when visual information about the partner’s movements was present but was decreased particularly at the shorter time scales when explicit gesturing in telling the joke was performed. In short, the results demonstrate that a complex interpersonal bodily “dance” occurs during structured conversation interactions and that this “dance” is constructed from a set of rhythms associated with the nested behavioral structure of the interaction. PMID:25177287

  17. Remote synchronization in star networks.

    PubMed

    Bergner, A; Frasca, M; Sciuto, G; Buscarino, A; Ngamga, E J; Fortuna, L; Kurths, J

    2012-02-01

    We study phase synchronization in a network motif with a starlike structure in which the central node's (the hub's) frequency is strongly detuned against the other peripheral nodes. We find numerically and experimentally a regime of remote synchronization (RS), where the peripheral nodes form a phase synchronized cluster, while the hub remains free with its own dynamics and serves just as a transmitter for the other nodes. We explain the mechanism for this RS by the existence of a free amplitude and also show that systems with a fixed or constant amplitude, such as the classic Kuramoto phase oscillator, are not able to generate this phenomenon. Further, we derive an analytic expression which supports our explanation of the mechanism.

  18. Cluster synchronization in oscillatory networks

    NASA Astrophysics Data System (ADS)

    Belykh, Vladimir N.; Osipov, Grigory V.; Petrov, Valentin S.; Suykens, Johan A. K.; Vandewalle, Joos

    2008-09-01

    Synchronous behavior in networks of coupled oscillators is a commonly observed phenomenon attracting a growing interest in physics, biology, communication, and other fields of science and technology. Besides global synchronization, one can also observe splitting of the full network into several clusters of mutually synchronized oscillators. In this paper, we study the conditions for such cluster partitioning into ensembles for the case of identical chaotic systems. We focus mainly on the existence and the stability of unique unconditional clusters whose rise does not depend on the origin of the other clusters. Also, conditional clusters in arrays of globally nonsymmetrically coupled identical chaotic oscillators are investigated. The design problem of organizing clusters into a given configuration is discussed.

  19. Chaotic synchronization system and electrocardiogram

    NASA Astrophysics Data System (ADS)

    Pei, Liuqing; Dai, Xinlai; Li, Baodong

    1997-01-01

    A mathematical model of chaotic synchronization of the heart-blood flow coupling dynamics is proposed, which is based on a seven dimension nonlinear dynamical system constructed by three subsystems of the sinoatrial node natural pacemaker, the cardiac relaxation oscillator and the dynamics of blood-fluid in heart chambers. The existence and robustness of the self-chaotic synchronization of the system are demonstrated by both methods of theoretical analysis and numerical simulation. The spectrum of Lyapunov exponent, the Lyapunov dimension and the Kolmogorov entropy are estimated when the system was undergoing the state of self-chaotic synchronization evolution. The time waveform of the dynamical variable, which represents the membrane potential of the cardiac integrative cell, shows a shape which is similar to that of the normal electrocardiogram (ECG) of human, thus implies that the model possesses physiological significance functionally.

  20. Digital data detection and synchronization

    NASA Technical Reports Server (NTRS)

    Noack, T. L.; Morris, J. F.

    1973-01-01

    The primary accomplishments have been in the analysis and simulation of receivers and bit synchronizers. It has been discovered that tracking rate effects play, a rather fundamental role in both receiver and synchronizer performance, but that data relating to recorder time-base-error, for the proper characterization of this phenomenon, is in rather short supply. It is possible to obtain operationally useful tape recorder time-base-error data from high signal-to-noise ratio tapes using synchronizers with relatively wideband tracking loops. Low signal-to-noise ratio tapes examined in the same way would not be synchronizable. Additional areas of interest covered are receiver false lock, cycle slipping, and other unusual phenomena, which have been described to some extent in this and earlier reports and simulated during the study.

  1. State observer for synchronous motors

    DOEpatents

    Lang, Jeffrey H.

    1994-03-22

    A state observer driven by measurements of phase voltages and currents for estimating the angular orientation of a rotor of a synchronous motor such as a variable reluctance motor (VRM). Phase voltages and currents are detected and serve as inputs to a state observer. The state observer includes a mathematical model of the electromechanical operation of the synchronous motor. The characteristics of the state observer are selected so that the observer estimates converge to the actual rotor angular orientation and velocity, winding phase flux linkages or currents.

  2. Synchronization with sound propagation delays

    NASA Astrophysics Data System (ADS)

    Haché, A.

    2010-04-01

    Complex systems that synchronize with acoustic signals, like chanting crowds and musical ensembles, have the intrinsic ability to maintain synchrony without external aid or visual cues, even when spread over wide areas. According to two models, the counterintuitive self-synchronization happens when the system's components have a spatial distribution that is sufficiently uniform. The roles of system size and density are examined for arrangements in 1, 2 and 3 dimensions. Asynchrony is predicted to become vanishingly small at high densities, and results suggest ways on how to minimize asynchrony in real-world situations.

  3. Optimized multiparty quantum clock synchronization

    SciTech Connect

    Ben-Av, Radel; Exman, Iaakov

    2011-07-15

    A multiparty protocol for distributed quantum clock synchronization has been claimed to provide universal limits on the clock accuracy, viz., that accuracy monotonically decreases with the number n of party members. But this is only true for synchronization when one limits oneself to W states. This work shows that the usage of Z (Symmetric Dicke) states, a generalization of W states, results in improved accuracy, having a maximum when Left-Floor n/2 Right-Floor of its members have their qubits with a |1> eigenstate.

  4. Pattern of induced estrus and conception rate following Ovsynch and Ovsynch based gonadotropin-releasing hormone treatments initiated on day 6 of estrous cycle in repeat breeding crossbred cows

    PubMed Central

    Ahmed, N.; Kathiresan, D.; Ahmed, F. A.; Lalrintluanga, K.; Mayengbam, P.; Gali, J. M.

    2016-01-01

    Aim: The aim was to evaluate the estrus response, incidence of accessory corpus luteum formation and fertility following different hormonal protocols in repeat breeding crossbred cows. Materials and Methods: This study was carried out on 24 repeat breeding crossbred cows allotted into four groups. Cows of Group I was not given any treatment, Group II was treated with gonadotropin-releasing hormone (GnRH) injection on day 6 post-estrus, Group III was treated with Ovsynch protocol, and Group IV was treated with Ovsynch based GnRH treatment. Estrus responses such as duration, onset, percentage, and intensity of estrus were recorded during the study. The incidence of accessory corpus luteum was recorded per rectally on day 7 after first and additional GnRH of Ovsynch treatment. The conception rate for all groups was calculated by the absence of estrus and on day 45 after artificial insemination (AI) per rectum. Serum samples were collected at AI and day 12 post-AI in Group I and II. Serum samples were also collected at GnRH, Prostaglandin F2α (PGF2α), timed AI (TAI) and day 12 post-TAI in Group III and IV. Results: Ovsynch and Ovsynch based GnRH treatments are resulted in 100.00% induction of estrus after the PGF2α injection. Onset of induced estrus after the PGF2α injection for Group III and IV was recorded as 48.750±0.713 and 51.472±1.989 h, respectively, and it was not significant. There was no significant difference in duration of estrus among the groups. The incidence of intermediate estrus intensity was found to be highest. All the cows showed the incidence of formation of accessory corpus luteum subsequent to GnRH treatment on day 6 of the estrous cycle in Group II, III, and IV. The conception rate was 0.00%, 16.67%, 50.00%, and 50.00% in Group I, II, III, and IV, respectively. Conclusion: Ovsynch and Ovsynch based GnRH treatments initiated on day 6 of estrous cycle capable of responding with a higher percentage of ovulation and formation of accessory

  5. Fermi Timing and Synchronization System

    SciTech Connect

    Wilcox, R.; Staples, J.; Doolittle, L.; Byrd, J.; Ratti, A.; Kaertner, F.X.; Kim, J.; Chen, J.; Ilday, F.O.; Ludwig, F.; Winter, A.; Ferianis, M.; Danailov, M.; D'Auria, G.

    2006-07-19

    The Fermi FEL will depend critically on precise timing of its RF, laser and diagnostic subsystems. The timing subsystem to coordinate these functions will need to reliably maintain sub-100fs synchronicity between distant points up to 300m apart in the Fermi facility. The technology to do this is not commercially available, and has not been experimentally demonstrated in a working facility. Therefore, new technology must be developed to meet these needs. Two approaches have been researched by different groups working with the Fermi staff. At MIT, a pulse transmission scheme has been developed for synchronization of RF and laser devices. And at LBL, a CW transmission scheme has been developed for RF and laser synchronization. These respective schemes have advantages and disadvantages that will become better understood in coming years. This document presents the work done by both teams, and suggests a possible system design which integrates them both. The integrated system design provides an example of how choices can be made between the different approaches without significantly changing the basic infrastructure of the system. Overall system issues common to any synchronization scheme are also discussed.

  6. Synchronization by elastic neuronal latencies

    NASA Astrophysics Data System (ADS)

    Vardi, Roni; Timor, Reut; Marom, Shimon; Abeles, Moshe; Kanter, Ido

    2013-01-01

    Psychological and physiological considerations entail that formation and functionality of neuronal cell assemblies depend upon synchronized repeated activation such as zero-lag synchronization. Several mechanisms for the emergence of this phenomenon have been suggested, including the global network quantity, the greatest common divisor of neuronal circuit delay loops. However, they require strict biological prerequisites such as precisely matched delays and connectivity, and synchronization is represented as a stationary mode of activity instead of a transient phenomenon. Here we show that the unavoidable increase in neuronal response latency to ongoing stimulation serves as a nonuniform gradual stretching of neuronal circuit delay loops. This apparent nuisance is revealed to be an essential mechanism in various types of neuronal time controllers, where synchronization emerges as a transient phenomenon and without predefined precisely matched synaptic delays. These findings are described in an experimental procedure where conditioned stimulations were enforced on a circuit of neurons embedded within a large-scale network of cortical cells in vitro, and are corroborated and extended by simulations of circuits composed of Hodgkin-Huxley neurons with time-dependent latencies. These findings announce a cortical time scale for time controllers based on tens of microseconds stretching of neuronal circuit delay loops per spike. They call for a reexamination of the role of the temporal periodic mode in brain functionality using advanced in vitro and in vivo experiments.

  7. Tweaking synchronization by connectivity modifications

    NASA Astrophysics Data System (ADS)

    Schultz, Paul; Peron, Thomas; Eroglu, Deniz; Stemler, Thomas; Ramírez Ávila, Gonzalo Marcelo; Rodrigues, Francisco A.; Kurths, Jürgen

    2016-06-01

    Natural and man-made networks often possess locally treelike substructures. Taking such tree networks as our starting point, we show how the addition of links changes the synchronization properties of the network. We focus on two different methods of link addition. The first method adds single links that create cycles of a well-defined length. Following a topological approach, we introduce cycles of varying length and analyze how this feature, as well as the position in the network, alters the synchronous behavior. We show that in particular short cycles can lead to a maximum change of the Laplacian's eigenvalue spectrum, dictating the synchronization properties of such networks. The second method connects a certain proportion of the initially unconnected nodes. We simulate dynamical systems on these network topologies, with the nodes' local dynamics being either discrete or continuous. Here our main result is that a certain number of additional links, with the relative position in the network being crucial, can be beneficial to ensure stable synchronization.

  8. Tweaking synchronization by connectivity modifications.

    PubMed

    Schultz, Paul; Peron, Thomas; Eroglu, Deniz; Stemler, Thomas; Ramírez Ávila, Gonzalo Marcelo; Rodrigues, Francisco A; Kurths, Jürgen

    2016-06-01

    Natural and man-made networks often possess locally treelike substructures. Taking such tree networks as our starting point, we show how the addition of links changes the synchronization properties of the network. We focus on two different methods of link addition. The first method adds single links that create cycles of a well-defined length. Following a topological approach, we introduce cycles of varying length and analyze how this feature, as well as the position in the network, alters the synchronous behavior. We show that in particular short cycles can lead to a maximum change of the Laplacian's eigenvalue spectrum, dictating the synchronization properties of such networks. The second method connects a certain proportion of the initially unconnected nodes. We simulate dynamical systems on these network topologies, with the nodes' local dynamics being either discrete or continuous. Here our main result is that a certain number of additional links, with the relative position in the network being crucial, can be beneficial to ensure stable synchronization.

  9. Tweaking synchronization by connectivity modifications.

    PubMed

    Schultz, Paul; Peron, Thomas; Eroglu, Deniz; Stemler, Thomas; Ramírez Ávila, Gonzalo Marcelo; Rodrigues, Francisco A; Kurths, Jürgen

    2016-06-01

    Natural and man-made networks often possess locally treelike substructures. Taking such tree networks as our starting point, we show how the addition of links changes the synchronization properties of the network. We focus on two different methods of link addition. The first method adds single links that create cycles of a well-defined length. Following a topological approach, we introduce cycles of varying length and analyze how this feature, as well as the position in the network, alters the synchronous behavior. We show that in particular short cycles can lead to a maximum change of the Laplacian's eigenvalue spectrum, dictating the synchronization properties of such networks. The second method connects a certain proportion of the initially unconnected nodes. We simulate dynamical systems on these network topologies, with the nodes' local dynamics being either discrete or continuous. Here our main result is that a certain number of additional links, with the relative position in the network being crucial, can be beneficial to ensure stable synchronization. PMID:27415259

  10. PCM synchronization by word stuffing

    NASA Technical Reports Server (NTRS)

    Butman, S.

    1969-01-01

    When a transmitted word, consisting of a number of pulses, is detected and removed from the data stream, the space left by the removal is eliminated by a memory buffer. This eliminates the need for a clock synchronizer thereby removing instability problems.

  11. Sports Medicine Meets Synchronized Swimming.

    ERIC Educational Resources Information Center

    Wenz, Betty J.; And Others

    This collection of articles contains information about synchronized swimming. Topics covered include general physiology and cardiovascular conditioning, flexibility exercises, body composition, strength training, nutrition, coach-athlete relationships, coping with competition stress and performance anxiety, and eye care. Chapters are included on…

  12. Speed control for synchronous motors

    NASA Technical Reports Server (NTRS)

    Packard, H.; Schott, J.

    1981-01-01

    Feedback circuit controls fluctuations in speed of synchronous ac motor. Voltage proportional to phase angle is developed by phase detector, rectified, amplified, compared to threshold, and reapplied positively or negatively to motor excitation circuit. Speed control reduces wow and flutter of audio turntables and tape recorders, and enhances hunting in gyroscope motors.

  13. Effects of P.G. 600 on the onset of estrus and ovulation rate in gilts treated with Regu-mate.

    PubMed

    Estienne, M J; Harper, A F; Horsley, B R; Estienne, C E; Knight, J W

    2001-11-01

    Three experiments assessed the onset of estrus and ovulation rate in gilts treated with gonadotropins after the withdrawal of an orally active progestin. In Exp. 1, all cycling gilts received the progestin (Regu-mate; Intervet America Inc., Millsboro, DE) at a rate of 15 mg/d for 18 d. Twenty-four hours after the last feeding of Regu-mate, 32 gilts received an i.m. injection of 400 I.U. PMSG and 200 I.U. hCG (P.G. 600, Intervet America, Inc.), and 32 gilts received an i.m. injection of deionized water. The percentage of gilts displaying estrus < or = 7 d (P = 0.64) and the injection-to-estrus interval (P = 0.37) were similar for P.G. 600-treated gilts (93.8% and 4.1 +/- 0.1 d) and controls (90.6% and 4.3 +/- 0.1 d). Ovulation rate was greater (P < 0.01) in P.G. 600-treated gilts (28.8 +/- 1.1) compared with controls (17.4 +/- 1.1). In Exp. 2, 58 cycling gilts received Regu-mate (15 mg/d) for 18 d. Twenty-four hours after Regu-mate withdrawal, gilts received i.m. P.G. 600 or water (n = 29/treatment). Gilts were bred via AI 12 and 24 h after first detection of estrus. The percentage of gilts displaying estrus < or = 7 d (P = 0.45) and the injection-to-estrus interval (P = 0.27) were similar for P.G. 600-treated gilts (82.7% and 4.0 +/- 0.1 d) and controls (89.7% and 4.2 +/- 0.1 d). Ovulation rate was greater (P < 0.01) in P.G. 600-treated gilts (26.2 +/- 1.8) compared with controls (18.1 +/- 1.7). Pregnancy rate (P = 0.71) and the number of live embryos at d 30 postmating (P = 0.40) were similar for P.G. 600-treated gilts (91.7% and 15.6 +/- 1.2) and controls (88.5% and 14.1 +/- 1.2). In Exp. 3, prepubertal gilts (142.6 +/- 0.7 d of age) received Regumate (15 mg/d) (n = 20) or a control diet not including Regu-mate (n = 20) for 18 d. Twenty-four hours after Regu-mate withdrawal, all gilts received i.m. P.G. 600. The percentage of gilts displaying estrus < or = 7 d (P = 0.49) and the P.G. 600-to-estrus interval (P = 0.69) were similar for Regu-mate-fed gilts (95% and

  14. Sensorimotor Synchronization across the Life Span

    ERIC Educational Resources Information Center

    Drewing, Knut; Aschersleben, Gisa; Li, Shu-Chen

    2006-01-01

    The present study investigates the contribution of general processing resources as well as other more specific factors to the life-span development of sensorimotor synchronization and its component processes. Within a synchronization tapping paradigm, a group of 286 participants, 6 to 88 years of age, were asked to synchronize finger taps with…

  15. High speed synchronizer card utilizing VLSI technology

    NASA Technical Reports Server (NTRS)

    Speciale, Nicholas; Wunderlich, Kristin

    1988-01-01

    A generic synchronizer card capable of providing standard NASA communication block telemetry frame synchronization and quality control was fabricated using VLSI technology. Four VLSI chip sets are utilized to shrink all the required functions into a single synchronizer card. The application of VLSI technology to telemetry systems resulted in an increase in performance and a decrease in cost and size.

  16. Delay synchronization of temporal Boolean networks

    NASA Astrophysics Data System (ADS)

    Wei, Qiang; Xie, Cheng-jun; Liang, Yi; Niu, Yu-jun; Lin, Da

    2016-01-01

    This paper investigates the delay synchronization between two temporal Boolean networks base on semi-tensor product method, which improve complete synchronization. Necessary and sufficient conditions for delay synchronization are drawn base on algebraic expression of temporal Boolean networks. A example is presented to show the effectiveness of theoretical analysis.

  17. Supplementation of dextrose to the diet during the weaning to estrus interval affects subsequent variation in within-litter piglet birth weight.

    PubMed

    Van den Brand, H; Soede, N M; Kemp, B

    2006-02-01

    Effects of supplementation of dextrose to the diet of sows during the weaning-to-estrus interval (WEI) on subsequent litter size and within-litter variation were investigated. After weaning, 223 sows (first to fifth parity) were fed 3.5 kg/d. Half of the sows additionally received 150 g of dextrose per day as topdressing on the feed. WEI and estrus duration were determined as well as subsequent pregnancy rate and litter size. Piglets were weighed individually at birth and at weaning (day 26.4; S.D.: 2.5). Supplementation of dextrose to the diet during the WEI did not affect WEI (106 h), pregnancy rate (88.2%), farrowing rate (84.2%), subsequent litter size (total born: 13.70), or birth weight (1599 g). The within-litter variation in birth weight was lower in sows on the dextrose treatment (CV: 17.5% versus 21.2% for the dextrose and control group, respectively, P=0.03). From this experiment, we concluded that addition of dextrose during the weaning to estrus interval did not increase litter size, but seems to affect the uniformity in birth weight of the litter. PMID:15967602

  18. [Variation of plasma INH B, ACT A and FSH concentrations during an estrus cycle in Dazu black goat and Sannen dairy goat].

    PubMed

    Zhang, Chao; Luo, Yan-Mei; Zhang, Jia-Hua; He, Jing-Jing; Jin, Lu; Zhao, Zhong-Quan

    2011-06-01

    To study the relationship between the concentrations of INH B (Inhibin B), ACT A (Activin A), and FSH (Follicle stimulating hormone) in blood plasma and fecundity, Dazu black goat with high productivity and Sannen dairy goat with low productivity were used as experiment objects in this research. The concentrations of INH B, ACT A, and FSH in blood plasma were measured by enzyme-linked immunosorbent assay (ELISA) in order to study the secretion rule of INH B, ACT A, and FSH during an estrus cycle of two goat breeds. The results indicated that the secretion of FSH showed a positive correlation with ACT A and a negative correlation with INH B. The mean concentration of FSH in Dazu black goat was higher than that in Sanen dairy goat during a estrous cycle. However, during the time from obviously estrus to ovulation, the mean concentration of FSH in Dazu black goat was significantly higher than that in Sannen dairy goat (0.01estrus cycle, the differences in INH B, ACT A, and FSH might be the reason for fecundity differences. Activin A might not be responsible for the number of eggs ovulated of goats. The main effect of ACT A may be extention of follicular stage. Inhibin B indirectly influences ovulation by regulation of FSH level.

  19. Role of the adrenal gland and adrenal-mediated chemosignals in suppression of estrus in the house mouse: the lee-boot effect revisited.

    PubMed

    Ma, W; Miao, Z; Novotny, M V

    1998-12-01

    Mature female mice, grouped in the absence of a male stimulus, exhibit a suppressed estrous cycle (the so-called Lee-Boot effect). We have designed a series of experiments to elucidate the involvement of the adrenal gland in this phenomenon. Our initial results indicate that adrenalectomized mice exhibit a regular estrous cycle in either isolated or grouped conditions. A single, intact mouse caged with five adrenalectomized females showed repeated normal cycles. When the urine samples from group-caged intact mice or group-caged adrenalectomized mice were applied to the external nares of singly caged females, estrous cycles were inhibited in the animals receiving urine from the intact mice but not from the adrenalectomized mice. In addition, corticosterone therapy restored the function of estrus suppression in grouped, adrenalectomized mice. We had previously shown that the urinary excretion of several volatile compounds (2-heptanone, trans-5-hepten-2-one, trans-4-hepten-2-one, pentyl acetate, cis-2-penten-1-yl acetate, and 2,5-dimethylpyrazine) was adrenal mediated (Science 1986; 231:722-725). A further testing of these compounds in relation to estrus suppression has now revealed that a mixture of these compounds is effective, but removing 2, 5-dimethylpyrazine from the mixture abolished the biological response. The overall results of this study show conclusively an important role of the adrenal gland and adrenal-mediated urinary metabolites in estrus suppression. PMID:9828173

  20. JSAR Innovative Technology Award. Development of ovulation synchronization and fixed time artificial insemination in dairy cows.

    PubMed

    Yamada, Kyoji

    2005-04-01

    Recently, reproductive management has become more difficult as a result of increased herd size. Problems with missing estrous signs and decrease in conception rate by artificial insemination (AI) performed at wrong timing have caused low AI conception rates. In 1995, ovulation synchronization and fixed-time AI (Ovsynch/TAI) was developed in the USA as a new reproductive technology, which was accepted as an useful reproductive management tool in many countries. However, no information on the use of Ovsynch/TAI was available in Japan. It was, therefore, warranted to show the ovulation rate and conception rate after Ovsynch/TAI using gonadotropin releasing hormone analogue (GnRH-A, fertirelin acetate) and prostaglandin F2alpha (PGF2alpha)-THAM, both were commercially available in this country. The conception rate after Ovsynch/TAI has been known to vary among different herds and individuals. Investigation and analysis of factors affecting the conception rate was also warranted to improve the conception rate. A series of experiments were carried out to establish Ovsynch/TAI using domestically produced GnRH-A and PGF2alpha and to study factors affecting conception rate after Ovsynch protocol. Ovsynch using 100 microg GnRH-A and 25 mg PGF2alpha were observed using ultrasonography. As a result, a high synchronization rate of ovulation at 16 to 20 h after the second GnRH injection was confirmed. The conception rate after Ovsynch/TAI was compared in 87 cows with the conception rate after AI at estrus induced by PGF2alpha (139 cows). Conception rate after Ovsynch/TAI was higher than the figure after AI at induced estrus (59.1% vs 20.9%, P<0.05). The dose of GnRH-A was also studied and a practical dose of GnRH-A was found to be 50 microg per cow. To clarify some factors affecting the conception rate after Ovsynch/TAI, 1,558 cows were investigated for the state of their ovaries, days after calving, parity, season, ovarian cyclicity postpartum and nutritional state at the day

  1. Targeting engineering synchronization in chaotic systems

    NASA Astrophysics Data System (ADS)

    Bhowmick, Sourav K.; Ghosh, Dibakar

    2016-07-01

    A method of targeting engineering synchronization states in two identical and mismatch chaotic systems is explained in detail. The method is proposed using linear feedback controller coupling for engineering synchronization such as mixed synchronization, linear and nonlinear generalized synchronization and targeting fixed point. The general form of coupling design to target any desire synchronization state under unidirectional coupling with the help of Lyapunov function stability theory is derived analytically. A scaling factor is introduced in the coupling definition to smooth control without any loss of synchrony. Numerical results are done on two mismatch Lorenz systems and two identical Sprott oscillators.

  2. Experience dependent plasticity alters cortical synchronization

    PubMed Central

    Kilgard, M.P.; Vazquez, J.L.; Engineer, N.D.; Pandya, P.K.

    2008-01-01

    Theories of temporal coding by cortical neurons are supported by observations that individual neurons can respond to sensory stimulation with millisecond precision and that activity in large populations is often highly correlated. Synchronization is highest between neurons with overlapping receptive fields and modulated by both sensory stimulation and behavioral state. It is not yet clear whether cortical synchronization is an epiphenomenon or a critical component of efficient information transmission. Experimental manipulations that generate receptive field plasticity can be used to test the relationship between synchronization and receptive fields. Here we demonstrate that increasing receptive field size in primary auditory cortex by repeatedly pairing a train of tones with nucleus basalis (NB) stimulation increases synchronization, and decreasing receptive field size by pairing different tone frequencies with NB stimulation decreases synchronization. These observations seem to support the conclusion that neural synchronization is simply an artifact caused by common inputs. However, pairing tone trains of different carrier frequencies with NB stimulation increases receptive field size without increasing synchronization, and environmental enrichment increases synchronization without increasing receptive field size. The observation that receptive fields and synchronization can be manipulated independently suggests that common inputs are only one of many factors shaping the strength and temporal precision of cortical synchronization and supports the hypothesis that precise neural synchronization contributes to sensory information processing. PMID:17317055

  3. Comparison of the pregnancy rates and costs per calf born after fixed-time artificial insemination or artificial insemination after estrus detection in Bos indicus heifers.

    PubMed

    Edwards, S A A; Bo, G A; Chandra, K A; Atkinson, P C; McGowan, M R

    2015-01-01

    This study compared pregnancy rates (PRs) and costs per calf born after fixed-time artificial insemination (FTAI) or AI after estrus detection (i.e., estrus detection and AI, EDAI), before and after a single PGF2α treatment in Bos indicus (Brahman-cross) heifers. On Day 0, the body weight, body condition score, and presence of a CL (46% of heifers) were determined. The heifers were then alternately allocated to one of two FTAI groups (FTAI-1, n = 139) and (FTAI-2, n = 141) and an EDAI group (n = 273). Heifers in the FTAI groups received an intravaginal progesterone-releasing device (IPRD; 0.78 g of progesterone) and 1 mg of estradiol benzoate intramuscularly (im) on Day 0. Eight days later, the IPRD was removed and heifers received 500 μg of PGF2α and 300 IU of eCG im; 24 hours later, they received 1 mg estradiol benzoate im and were submitted to FTAI 30 to 34 hours later (54 and 58 hours after IPRD removal). Heifers in the FTAI-2 group started treatment 8 days after those in the FTAI-1 group. Heifers in the EDAI group were inseminated approximately 12 hours after the detection of estrus between Days 4 and 9 at which time the heifers that had not been detected in estrus received 500 μg of PGF2α im and EDAI continued until Day 13. Heifers in the FTAI groups had a higher overall PR (proportion pregnant as per the entire group) than the EDAI group (34.6% vs. 23.2%; P = 0.003), however, conception rate (PR of heifers submitted for AI) tended to favor the estrus detection group (34.6% vs. 44.1%; P = 0.059). The cost per AI calf born was estimated to be $267.67 and $291.37 for the FTAI and EDAI groups, respectively. It was concluded that in Brahman heifers typical of those annually mated in northern Australia FTAI compared with EDAI increases the number of heifers pregnant and reduces the cost per calf born.

  4. Comparison of the pregnancy rates and costs per calf born after fixed-time artificial insemination or artificial insemination after estrus detection in Bos indicus heifers.

    PubMed

    Edwards, S A A; Bo, G A; Chandra, K A; Atkinson, P C; McGowan, M R

    2015-01-01

    This study compared pregnancy rates (PRs) and costs per calf born after fixed-time artificial insemination (FTAI) or AI after estrus detection (i.e., estrus detection and AI, EDAI), before and after a single PGF2α treatment in Bos indicus (Brahman-cross) heifers. On Day 0, the body weight, body condition score, and presence of a CL (46% of heifers) were determined. The heifers were then alternately allocated to one of two FTAI groups (FTAI-1, n = 139) and (FTAI-2, n = 141) and an EDAI group (n = 273). Heifers in the FTAI groups received an intravaginal progesterone-releasing device (IPRD; 0.78 g of progesterone) and 1 mg of estradiol benzoate intramuscularly (im) on Day 0. Eight days later, the IPRD was removed and heifers received 500 μg of PGF2α and 300 IU of eCG im; 24 hours later, they received 1 mg estradiol benzoate im and were submitted to FTAI 30 to 34 hours later (54 and 58 hours after IPRD removal). Heifers in the FTAI-2 group started treatment 8 days after those in the FTAI-1 group. Heifers in the EDAI group were inseminated approximately 12 hours after the detection of estrus between Days 4 and 9 at which time the heifers that had not been detected in estrus received 500 μg of PGF2α im and EDAI continued until Day 13. Heifers in the FTAI groups had a higher overall PR (proportion pregnant as per the entire group) than the EDAI group (34.6% vs. 23.2%; P = 0.003), however, conception rate (PR of heifers submitted for AI) tended to favor the estrus detection group (34.6% vs. 44.1%; P = 0.059). The cost per AI calf born was estimated to be $267.67 and $291.37 for the FTAI and EDAI groups, respectively. It was concluded that in Brahman heifers typical of those annually mated in northern Australia FTAI compared with EDAI increases the number of heifers pregnant and reduces the cost per calf born. PMID:25284281

  5. Structural elucidation of estrus urinary lipocalin protein (EULP) and evaluating binding affinity with pheromones using molecular docking and fluorescence study

    PubMed Central

    Rajesh, Durairaj; Muthukumar, Subramanian; Saibaba, Ganesan; Siva, Durairaj; Akbarsha, Mohammad Abdulkader; Gulyás, Balázs; Padmanabhan, Parasuraman; Archunan, Govindaraju

    2016-01-01

    Transportation of pheromones bound with carrier proteins belonging to lipocalin superfamily is known to prolong chemo-signal communication between individuals belonging to the same species. Members of lipocalin family (MLF) proteins have three structurally conserved motifs for delivery of hydrophobic molecules to the specific recognizer. However, computational analyses are critically required to validate and emphasize the sequence and structural annotation of MLF. This study focused to elucidate the evolution, structural documentation, stability and binding efficiency of estrus urinary lipocalin protein (EULP) with endogenous pheromones adopting in-silico and fluorescence study. The results revealed that: (i) EULP perhaps originated from fatty acid binding protein (FABP) revealed in evolutionary analysis; (ii) Dynamic simulation study shows that EULP is highly stable at below 0.45 Å of root mean square deviation (RMSD); (iii) Docking evaluation shows that EULP has higher binding energy with farnesol and 2-iso-butyl-3-methoxypyrazine (IBMP) than 2-naphthol; and (iv) Competitive binding and quenching assay revealed that purified EULP has good binding interaction with farnesol. Both, In-silico and experimental studies showed that EULP is an efficient binding partner to pheromones. The present study provides impetus to create a point mutation for increasing longevity of EULP to develop pheromone trap for rodent pest management. PMID:27782155

  6. Analysis of remote synchronization in complex networks.

    PubMed

    Gambuzza, Lucia Valentina; Cardillo, Alessio; Fiasconaro, Alessandro; Fortuna, Luigi; Gómez-Gardeñes, Jesus; Frasca, Mattia

    2013-12-01

    A novel regime of synchronization, called remote synchronization, where the peripheral nodes form a phase synchronized cluster not including the hub, was recently observed in star motifs [Bergner et al., Phys. Rev. E 85, 026208 (2012)]. We show the existence of a more general dynamical state of remote synchronization in arbitrary networks of coupled oscillators. This state is characterized by the synchronization of pairs of nodes that are not directly connected via a physical link or any sequence of synchronized nodes. This phenomenon is almost negligible in networks of phase oscillators as its underlying mechanism is the modulation of the amplitude of those intermediary nodes between the remotely synchronized units. Our findings thus show the ubiquity and robustness of these states and bridge the gap from their recent observation in simple toy graphs to complex networks. PMID:24387542

  7. Synchronous clock stopper for microprocessor

    NASA Technical Reports Server (NTRS)

    Kitchin, David A. (Inventor)

    1985-01-01

    A synchronous clock stopper circuit for inhibiting clock pulses to a microprocessor in response to a stop request signal, and for reinstating the clock pulses in response to a start request signal thereby to conserve power consumption of the microprocessor when used in an environment of limited power. The stopping and starting of the microprocessor is synchronized, by a phase tracker, with the occurrences of a predetermined phase in the instruction cycle of the microprocessor in which the I/O data and address lines of the microprocessor are of high impedance so that a shared memory connected to the I/O lines may be accessed by other peripheral devices. The starting and stopping occur when the microprocessor initiates and completes, respectively, an instruction, as well as before and after transferring data with a memory. Also, the phase tracker transmits phase information signals over a bus to other peripheral devices which signals identify the current operational phase of the microprocessor.

  8. Multiobjective synchronization of coupled systems

    NASA Astrophysics Data System (ADS)

    Tang, Yang; Wang, Zidong; Wong, W. K.; Kurths, Jürgen; Fang, Jian-an

    2011-06-01

    In this paper, multiobjective synchronization of chaotic systems is investigated by especially simultaneously minimizing optimization of control cost and convergence speed. The coupling form and coupling strength are optimized by an improved multiobjective evolutionary approach that includes a hybrid chromosome representation. The hybrid encoding scheme combines binary representation with real number representation. The constraints on the coupling form are also considered by converting the multiobjective synchronization into a multiobjective constraint problem. In addition, the performances of the adaptive learning method and non-dominated sorting genetic algorithm-II as well as the effectiveness and contributions of the proposed approach are analyzed and validated through the Rössler system in a chaotic or hyperchaotic regime and delayed chaotic neural networks.

  9. Parallel integrated frame synchronizer chip

    NASA Technical Reports Server (NTRS)

    Ghuman, Parminder Singh (Inventor); Solomon, Jeffrey Michael (Inventor); Bennett, Toby Dennis (Inventor)

    2000-01-01

    A parallel integrated frame synchronizer which implements a sequential pipeline process wherein serial data in the form of telemetry data or weather satellite data enters the synchronizer by means of a front-end subsystem and passes to a parallel correlator subsystem or a weather satellite data processing subsystem. When in a CCSDS mode, data from the parallel correlator subsystem passes through a window subsystem, then to a data alignment subsystem and then to a bit transition density (BTD)/cyclical redundancy check (CRC) decoding subsystem. Data from the BTD/CRC decoding subsystem or data from the weather satellite data processing subsystem is then fed to an output subsystem where it is output from a data output port.

  10. Synchronous network of distant telescopes

    NASA Astrophysics Data System (ADS)

    Zhilyaev, B.; Svyatogorov, O.; Verlyuk, I.; Andreev, M.; Sergeev, A.; Lovkaya, M.; Antov, A.; Konstantinova-Antova, R.; Bogdanovski, R.; Avgoloupis, S.; Seiradakis, J.; Contadakis, M. E.

    The Synchronous Network of distant Telescopes (SNT) represents an innovative approach in observational astrophysics. The authors present an unique existing realization of the SNT-conception. It was founded within the international collaboration between astronomical observatories of Ukraine, Russia, Bulgaria and Greece. All the telescopes of the Network are equipped with standardized photometric systems (based on photo-multipliers). The unified timing systems (based on GPS-receivers) synchronize all the apertures to UTC with an accuracy of 1 microsecond and better. The essential parts of the SNT are the original software for operating and data processing. The described international Network successfully works for more than 10 years. The obtained unique observational data made it possible to discover new fine-scale features and flare-triggered phenomena in flaring red dwarfs, as well as the recently found high-frequency variability in some chromospherically active stars.

  11. Producing Newborn Synchronous Mammalian Cells

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R.; Helmstetter, Charles E.; Thornton, Maureen

    2008-01-01

    A method and bioreactor for the continuous production of synchronous (same age) population of mammalian cells have been invented. The invention involves the attachment and growth of cells on an adhesive-coated porous membrane immersed in a perfused liquid culture medium in a microgravity analog bioreactor. When cells attach to the surface divide, newborn cells are released into the flowing culture medium. The released cells, consisting of a uniform population of synchronous cells are then collected from the effluent culture medium. This invention could be of interest to researchers investigating the effects of the geneotoxic effects of the space environment (microgravity, radiation, chemicals, gases) and to pharmaceutical and biotechnology companies involved in research on aging and cancer, and in new drug development and testing.

  12. Conveyor-belt clock synchronization

    SciTech Connect

    Giovannetti, Vittorio; Maccone, Lorenzo; Shapiro, Jeffrey H.; Wong, Franco N.C.; Lloyd, Seth

    2004-10-01

    A protocol for synchronizing distant clocks is proposed that does not rely on the arrival times of the signals which are exchanged, and an optical implementation based on coherent-state pulses is described. This protocol is not limited by any dispersion that may be present in the propagation medium through which the light signals are exchanged. Possible improvements deriving from the use of quantum-mechanical effects are also addressed.

  13. The LASSO experiment. [clock synchronization

    NASA Technical Reports Server (NTRS)

    Serene, B.

    1979-01-01

    An international coordinated experimental assessment of a system which promises to provide a synchronization of clocks bound to time and frequency standard laboratories, with an accuracy of one nanosecond using existing or near ground-based laser stations via a geostationary satellite (SIRIO-2) is detailed. The system performance and the technical details concerning the on-board equiment, the ground segment, and the operational configuration are discussed. Finally, the future prospects of the LASSO experiment and possible implementations are examined together.

  14. Digital-data receiver synchronization

    DOEpatents

    Smith, Stephen F.; Turner, Gary W.

    2005-08-02

    Digital-data receiver synchronization is provided with composite phase-frequency detectors, mutually cross-connected comparison feedback or both to provide robust reception of digital data signals. A single master clock can be used to provide frequency signals. Advantages can include fast lock-up time in moderately to severely noisy conditions, greater tolerance to noise and jitter when locked, and improved tolerance to clock asymmetries.

  15. Network synchronization in hippocampal neurons.

    PubMed

    Penn, Yaron; Segal, Menahem; Moses, Elisha

    2016-03-22

    Oscillatory activity is widespread in dynamic neuronal networks. The main paradigm for the origin of periodicity consists of specialized pacemaking elements that synchronize and drive the rest of the network; however, other models exist. Here, we studied the spontaneous emergence of synchronized periodic bursting in a network of cultured dissociated neurons from rat hippocampus and cortex. Surprisingly, about 60% of all active neurons were self-sustained oscillators when disconnected, each with its own natural frequency. The individual neuron's tendency to oscillate and the corresponding oscillation frequency are controlled by its excitability. The single neuron intrinsic oscillations were blocked by riluzole, and are thus dependent on persistent sodium leak currents. Upon a gradual retrieval of connectivity, the synchrony evolves: Loose synchrony appears already at weak connectivity, with the oscillators converging to one common oscillation frequency, yet shifted in phase across the population. Further strengthening of the connectivity causes a reduction in the mean phase shifts until zero-lag is achieved, manifested by synchronous periodic network bursts. Interestingly, the frequency of network bursting matches the average of the intrinsic frequencies. Overall, the network behaves like other universal systems, where order emerges spontaneously by entrainment of independent rhythmic units. Although simplified with respect to circuitry in the brain, our results attribute a basic functional role for intrinsic single neuron excitability mechanisms in driving the network's activity and dynamics, contributing to our understanding of developing neural circuits.

  16. Network synchronization in hippocampal neurons

    PubMed Central

    Penn, Yaron; Segal, Menahem; Moses, Elisha

    2016-01-01

    Oscillatory activity is widespread in dynamic neuronal networks. The main paradigm for the origin of periodicity consists of specialized pacemaking elements that synchronize and drive the rest of the network; however, other models exist. Here, we studied the spontaneous emergence of synchronized periodic bursting in a network of cultured dissociated neurons from rat hippocampus and cortex. Surprisingly, about 60% of all active neurons were self-sustained oscillators when disconnected, each with its own natural frequency. The individual neuron’s tendency to oscillate and the corresponding oscillation frequency are controlled by its excitability. The single neuron intrinsic oscillations were blocked by riluzole, and are thus dependent on persistent sodium leak currents. Upon a gradual retrieval of connectivity, the synchrony evolves: Loose synchrony appears already at weak connectivity, with the oscillators converging to one common oscillation frequency, yet shifted in phase across the population. Further strengthening of the connectivity causes a reduction in the mean phase shifts until zero-lag is achieved, manifested by synchronous periodic network bursts. Interestingly, the frequency of network bursting matches the average of the intrinsic frequencies. Overall, the network behaves like other universal systems, where order emerges spontaneously by entrainment of independent rhythmic units. Although simplified with respect to circuitry in the brain, our results attribute a basic functional role for intrinsic single neuron excitability mechanisms in driving the network’s activity and dynamics, contributing to our understanding of developing neural circuits. PMID:26961000

  17. Network synchronization in hippocampal neurons.

    PubMed

    Penn, Yaron; Segal, Menahem; Moses, Elisha

    2016-03-22

    Oscillatory activity is widespread in dynamic neuronal networks. The main paradigm for the origin of periodicity consists of specialized pacemaking elements that synchronize and drive the rest of the network; however, other models exist. Here, we studied the spontaneous emergence of synchronized periodic bursting in a network of cultured dissociated neurons from rat hippocampus and cortex. Surprisingly, about 60% of all active neurons were self-sustained oscillators when disconnected, each with its own natural frequency. The individual neuron's tendency to oscillate and the corresponding oscillation frequency are controlled by its excitability. The single neuron intrinsic oscillations were blocked by riluzole, and are thus dependent on persistent sodium leak currents. Upon a gradual retrieval of connectivity, the synchrony evolves: Loose synchrony appears already at weak connectivity, with the oscillators converging to one common oscillation frequency, yet shifted in phase across the population. Further strengthening of the connectivity causes a reduction in the mean phase shifts until zero-lag is achieved, manifested by synchronous periodic network bursts. Interestingly, the frequency of network bursting matches the average of the intrinsic frequencies. Overall, the network behaves like other universal systems, where order emerges spontaneously by entrainment of independent rhythmic units. Although simplified with respect to circuitry in the brain, our results attribute a basic functional role for intrinsic single neuron excitability mechanisms in driving the network's activity and dynamics, contributing to our understanding of developing neural circuits. PMID:26961000

  18. Intonation contour in synchronous speech

    NASA Astrophysics Data System (ADS)

    Wang, Bei; Cummins, Fred

    2003-10-01

    Synchronous Speech (Syn-S), obtained by having pairs of speakers read a prepared text together, has been shown to result in interesting properties in the temporal domain, especially in the reduction of inter-speaker variability in supersegmental timing [F. Cummins, ARLO 3, 7-11 (2002)]. Here we investigate the effect of synchronization among speakers on the intonation contour, with a view to informing models of intonation. Six pairs of speakers (all females) read a short text (176 words) both synchronously and solo. Results show that (1) the pitch accent height above a declining baseline is reduced in Syn-S, compared with solo speech, while the pitch accent location is consistent across speakers in both conditions; (2) in contrast to previous findings on duration matching, there is an asymmetry between speakers, with one speaker exerting a stronger influence on the observed intonation contour than the other; (3) agreement on the boundaries of intonational phrases is greater in Syn-S and intonation contours are well matched from the first syllable of the phrase and throughout.

  19. Synchronizer of transmission for vehicles

    SciTech Connect

    Katayama, N.

    1986-02-25

    A synchronizer of a transmission for vehicles is described comprising: a double-mesh prevention member provided on a shift-and-select lever shaft and adapted to restrict the movement of fork shafts of the transmission. The double-mesh prevention member has at least two engaging portions for engaging first and second forward fork shafts, a first gap between the first engaging portion and the first forward fork shaft is greater than a second gap between the second engaging portion and the second forward fork shaft; a pin carried by the first forward fork shaft and biased substantially radially outwardly from the first forward fork shaft by resilient means; and a cam provided on the shift-and-select lever shaft, the cam is shaped and adapted to engage the pin, when the shift-and-select lever shaft is operated to shift to the reverse position, to press the pin so as to move the first forward fork shaft axially until the first forward fork shaft engages the first engaging portion, and thereafter to press the pin radially into the first forward fork shaft; whereby, upon shifting to the reverse position, the first forward fork shaft is moved by the pin and cam to put a synchronizer for forward gears into effect, thereby to attain synchronization between an input shaft and an output shaft of the transmission, but is prevented by the first engaging portion from moving far enough to engage a forward gear.

  20. Temporal integration in sensorimotor synchronization.

    PubMed

    Mates, J; Müller, U; Radil, T; Pöppel, E

    1994-01-01

    Abstract The concept of a temporal integration process in the timing mechanisms in the brain, postulated on the basis of experimental observations from various paradigms (for a review see P$oUppel, 1978), has been explored in a sensorimotor synchronization task. Subjects synchronized their finger taps to sequences of auditory stimuli with interstimulus-onset intervals (ISIs) between 300 and 4800 msec in different trials. Each tonal sequence consisted of 110 stimuli; the tones had a frequency of 500 Hz and a duration of 100 msec. As observed previously, response onsets preceded onsets of the stimuli by some tens of milliseconcls for ISIs in the range from about 600 to 1800 msec. For ISIs longer than or equal to 2400 msec, the ability to time the response sequence in such a way that the response 5 were placed right ahead of the stimuli started to break clown, i.e., the task was fulfilled by reactions to the stimuli rather than by advanced responses. This observation can he understood within the general framework of a temporal integration puce 55 that is supposed to have a maximal capacity (integration interval) of approximately 3 sec. Only if successive stimuli fall within one integration period, can motor programs be initiated properly by a prior stimulus and thus lead to an appropriate synchronization between the stimulus sequence and corresponding motor acts.

  1. Embryonic mortality in buffaloes synchronized and mated by AI during the seasonal decline in reproductive function.

    PubMed

    Campanile, Giuseppe; Neglia, Gianluca; Gasparrini, Bianca; Galiero, Giorgio; Prandi, Alberto; Di Palo, Rossella; D'Occhio, Michael J; Zicarelli, Luigi

    2005-05-01

    The aim was to determine the factors that contribute to embryonic mortality in buffaloes mated by AI during a period of increasing day length which corresponds to a natural decline in reproductive activity. Italian Mediterranean buffalo cows (n=243) showing regular estrous cycles were synchronized using the Ovsynch-TAI program and mated by AI at 16 and 40 h after the second injection of GnRH. Blood samples were collected on Days 10 and 20 after the first AI and assayed for progesterone (P4). Pregnancy diagnosis was undertaken on Days 26 and 40 after the first AI using rectal ultrasonography. Buffaloes with a conceptus on Day 26 but not on Day 40 were judged to have undergone embryonic mortality and for these animals uterine fluid was recovered by flushing and analysed for common infectious agents. Estrus synchronization was achieved in 86% of buffaloes and the pregnancy rate on Day 40 was 34%. Embryonic mortality between Days 26 and 40 occurred in 45% of buffaloes and was associated with the presence of significant infectious agents in only 10 buffaloes (8%). Concentrations of P4 on Day 10 after AI were higher (P<0.05) in buffaloes that established a pregnancy than in buffaloes that showed embryonic mortality that was not associated with infectious agents. Similarly, on Day 20 after AI P4 concentrations were higher (P<0.01) in pregnant buffaloes compared with non-pregnant buffaloes and buffaloes that had embryonic mortality. It is concluded that a reduced capacity for P4 secretion can explain around 50% of embryonic mortalities in buffaloes synchronised and mated by AI during a period of low reproductive activity and that other as yet unidentified factors also have a significant effect on embryonic survival. PMID:15826694

  2. Synchronization transition in networked chaotic oscillators: the viewpoint from partial synchronization.

    PubMed

    Fu, Chenbo; Lin, Weijie; Huang, Liang; Wang, Xingang

    2014-05-01

    Synchronization transition in networks of nonlocally coupled chaotic oscillators is investigated. It is found that in reaching the state of global synchronization the networks can stay in various states of partial synchronization. The stability of the partial synchronization states is analyzed by the method of eigenvalue analysis, in which the important roles of the network topological symmetry on synchronization transition are identified. Moreover, for networks possessing multiple topological symmetries, it is found that the synchronization transition can be divided into different stages, with each stage characterized by a unique synchronous pattern of the oscillators. Synchronization transitions in networks of nonsymmetric topology and nonidentical oscillators are also investigated, where the partial synchronization states, although unstable, are found to be still playing important roles in the transitions.

  3. Effect of prostaglandin F2alpha at the time of AI on progesterone levels and pregnancy rate in synchronized Italian Mediterranean buffaloes.

    PubMed

    Neglia, G; Natale, A; Esposito, G; Salzillo, F; Adinolfi, L; Campanile, G; Francillo, M; Zicarelli, L

    2008-05-01

    The aims of this study were to evaluate the effects of an intravenous or intramuscular PGF2alpha analogue administration on the day of estrus on progesterone concentration and pregnancy rate in buffaloes undergoing artificial insemination (AI). To this end, two experiments were carried out. The first study was performed on 72 Mediterranean buffaloes synchronized by the Ovsynch-TAI Program. On the day of estrus only animals considered in heat were divided into four groups: Groups IVC and IMC received, respectively, an intravenous or intramuscular injection of cloprostenol (0.524 mg), whereas control Groups IVS and IMS received the same injections of saline. Milk samples were collected daily from each animal to assess progesterone concentration in the whey by RIA method. In addition on alternate days, buffaloes underwent transrectal ultrasound analysis. The second study was carried out on 385 buffaloes synchronized by the Ovsynch-TAI Program. On the day of AI, animals were divided in four groups, as described in experiment 1. Pregnancy rate was evaluated either on day 26 or day 45 and embryonic mortality rate was recorded. Statistical analysis was performed by ANOVA and chi2 test. A higher (P<0.05) progesterone concentration was recorded on day 11 (Day 0=estrus day) in Groups IVC and IMC compared to Groups IVS and IMS (351.6+/-129.7 and 355.8+/-112.2 pg ml(-1) vs. 239.8+/-81.1 and 243.6+/-90.5 pg ml(-1), respectively). Furthermore, a larger CL was recorded on the same day in treated vs. control groups (1.25+/-0.15 and 1.27+/-0.17 cm, respectively, in Groups IVC and IMC vs. 1.08+/-0.14 and 1.05+/-0.13 cm in IVS and IMS). In the second study, a higher pregnancy rate was observed in treated (IVC+IMC) vs. control (IVS+IMS) groups (46.7% vs. 30.7%; P<0.01), while no differences were recorded between treated groups. From these data, it can be concluded that either intravenous or intramuscular administration of PGF2alpha at the time of AI can enhance progesterone levels and

  4. Spectral Analysis of Synchronization in Mobile Networks

    NASA Astrophysics Data System (ADS)

    Fujiwara, Naoya; Kurths, Jürgen; Díaz-Guilera, Albert

    2011-09-01

    We here analyze a system consisting of agents moving in a two-dimensional space that interact with other agents if they are within a finite range. Considering the motion and the interaction of the agents, the system can be understood as a network with a time-dependent topology. Dynamically, the agents are assumed to be identical oscillators, and the system will eventually reach a state of complete synchronization. In a previous work, we have shown that two qualitatively different mechanisms leading to synchronization in such mobile networks exist, namely global synchronization and local synchronization, depending on the parameters that characterize the oscillatory dynamics and the motion of the agents [1]. In this contribution we show that the spectral pattern differs between the two synchronization mechanisms. For global synchronization the spectrum is flat, which means that all eigenmodes contribute identically. For local synchronization, instead, the synchronization dynamics is determined mostly by the eigenmodes whose eigenvalues are close to zero. This result suggests that the global synchronization mechanism achieves fast synchronization by efficiently using the fast decaying eigenmodes (larger eigenvalues).

  5. Influence of estrus expression prior to fixed-time AI on embryo survival to maternal recognition of pregnancy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estradiol has been reported to play a critical role in pregnancy establishment and embryonic survival. Our objective was to focus on the role of preovulatory estradiol in embryo survival from fertilization to maternal recognition of pregnancy. Beef cows (n = 29) were synchronized with the CO-Synch p...

  6. Synchronizing noisy nonidentical oscillators by transient uncoupling

    NASA Astrophysics Data System (ADS)

    Tandon, Aditya; Schröder, Malte; Mannattil, Manu; Timme, Marc; Chakraborty, Sagar

    2016-09-01

    Synchronization is the process of achieving identical dynamics among coupled identical units. If the units are different from each other, their dynamics cannot become identical; yet, after transients, there may emerge a functional relationship between them—a phenomenon termed "generalized synchronization." Here, we show that the concept of transient uncoupling, recently introduced for synchronizing identical units, also supports generalized synchronization among nonidentical chaotic units. Generalized synchronization can be achieved by transient uncoupling even when it is impossible by regular coupling. We furthermore demonstrate that transient uncoupling stabilizes synchronization in the presence of common noise. Transient uncoupling works best if the units stay uncoupled whenever the driven orbit visits regions that are locally diverging in its phase space. Thus, to select a favorable uncoupling region, we propose an intuitive method that measures the local divergence at the phase points of the driven unit's trajectory by linearizing the flow and subsequently suppresses the divergence by uncoupling.

  7. A chimeric path to neuronal synchronization

    SciTech Connect

    Essaki Arumugam, Easwara Moorthy; Spano, Mark L.

    2015-01-15

    Synchronization of neuronal activity is associated with neurological disorders such as epilepsy. This process of neuronal synchronization is not fully understood. To further our understanding, we have experimentally studied the progression of this synchronization from normal neuronal firing to full synchronization. We implemented nine FitzHugh-Nagumo neurons (a simplified Hodgkin-Huxley model) via discrete electronics. For different coupling parameters (synaptic strengths), the neurons in the ring were either unsynchronized or completely synchronized when locally coupled in a ring. When a single long-range connection (nonlocal coupling) was introduced, an intermediate state known as a chimera appeared. The results indicate that (1) epilepsy is likely not only a dynamical disease but also a topological disease, strongly tied to the connectivity of the underlying network of neurons, and (2) the synchronization process in epilepsy may not be an “all or none” phenomenon, but can pass through an intermediate stage (chimera)

  8. Spatio-temporal synchronization of recurrent epidemics.

    PubMed Central

    He, Daihai; Stone, Lewi

    2003-01-01

    Long-term spatio-temporal datasets of disease incidences have made it clear that many recurring epidemics, especially childhood infections, tend to synchronize in-phase across suburbs. In some special cases, epidemics between suburbs have been found to oscillate in an out-of-phase ('antiphase') relationship for lengthy periods. Here, we use modelling techniques to help explain the presence of in-phase and antiphase synchronization. The nonlinearity of the epidemic dynamics is often such that the intensity of the outbreak influences the phase of the oscillation thereby introducing 'shear', a factor that is found to be important for generating antiphase synchronization. By contrast, the coupling between suburbs via the immigration of infectives tends to enhance in-phase synchronization. The emerging synchronization depends delicately on these opposite factors. We use theoretical results from continuous time models to provide a framework for understanding the relationship between synchronization patterns for different model structures. PMID:12965019

  9. A chimeric path to neuronal synchronization

    NASA Astrophysics Data System (ADS)

    Essaki Arumugam, Easwara Moorthy; Spano, Mark L.

    2015-01-01

    Synchronization of neuronal activity is associated with neurological disorders such as epilepsy. This process of neuronal synchronization is not fully understood. To further our understanding, we have experimentally studied the progression of this synchronization from normal neuronal firing to full synchronization. We implemented nine FitzHugh-Nagumo neurons (a simplified Hodgkin-Huxley model) via discrete electronics. For different coupling parameters (synaptic strengths), the neurons in the ring were either unsynchronized or completely synchronized when locally coupled in a ring. When a single long-range connection (nonlocal coupling) was introduced, an intermediate state known as a chimera appeared. The results indicate that (1) epilepsy is likely not only a dynamical disease but also a topological disease, strongly tied to the connectivity of the underlying network of neurons, and (2) the synchronization process in epilepsy may not be an "all or none" phenomenon, but can pass through an intermediate stage (chimera).

  10. Explosive synchronization coexists with classical synchronization in the Kuramoto model.

    PubMed

    Danziger, Michael M; Moskalenko, Olga I; Kurkin, Semen A; Zhang, Xiyun; Havlin, Shlomo; Boccaletti, Stefano

    2016-06-01

    Explosive synchronization has recently been reported in a system of adaptively coupled Kuramoto oscillators, without any conditions on the frequency or degree of the nodes. Here, we find that, in fact, the explosive phase coexists with the standard phase of the Kuramoto oscillators. We determine this by extending the mean-field theory of adaptively coupled oscillators with full coupling to the case with partial coupling of a fraction f. This analysis shows that a metastable region exists for all finite values of f > 0, and therefore explosive synchronization is expected for any perturbation of adaptively coupling added to the standard Kuramoto model. We verify this theory with GPU-accelerated simulations on very large networks (N ∼ 10(6)) and find that, in fact, an explosive transition with hysteresis is observed for all finite couplings. By demonstrating that explosive transitions coexist with standard transitions in the limit of f → 0, we show that this behavior is far more likely to occur naturally than was previously believed. PMID:27369869

  11. Explosive synchronization coexists with classical synchronization in the Kuramoto model.

    PubMed

    Danziger, Michael M; Moskalenko, Olga I; Kurkin, Semen A; Zhang, Xiyun; Havlin, Shlomo; Boccaletti, Stefano

    2016-06-01

    Explosive synchronization has recently been reported in a system of adaptively coupled Kuramoto oscillators, without any conditions on the frequency or degree of the nodes. Here, we find that, in fact, the explosive phase coexists with the standard phase of the Kuramoto oscillators. We determine this by extending the mean-field theory of adaptively coupled oscillators with full coupling to the case with partial coupling of a fraction f. This analysis shows that a metastable region exists for all finite values of f > 0, and therefore explosive synchronization is expected for any perturbation of adaptively coupling added to the standard Kuramoto model. We verify this theory with GPU-accelerated simulations on very large networks (N ∼ 10(6)) and find that, in fact, an explosive transition with hysteresis is observed for all finite couplings. By demonstrating that explosive transitions coexist with standard transitions in the limit of f → 0, we show that this behavior is far more likely to occur naturally than was previously believed.

  12. Explosive synchronization coexists with classical synchronization in the Kuramoto model

    NASA Astrophysics Data System (ADS)

    Danziger, Michael M.; Moskalenko, Olga I.; Kurkin, Semen A.; Zhang, Xiyun; Havlin, Shlomo; Boccaletti, Stefano

    2016-06-01

    Explosive synchronization has recently been reported in a system of adaptively coupled Kuramoto oscillators, without any conditions on the frequency or degree of the nodes. Here, we find that, in fact, the explosive phase coexists with the standard phase of the Kuramoto oscillators. We determine this by extending the mean-field theory of adaptively coupled oscillators with full coupling to the case with partial coupling of a fraction f. This analysis shows that a metastable region exists for all finite values of f > 0, and therefore explosive synchronization is expected for any perturbation of adaptively coupling added to the standard Kuramoto model. We verify this theory with GPU-accelerated simulations on very large networks (N ˜ 106) and find that, in fact, an explosive transition with hysteresis is observed for all finite couplings. By demonstrating that explosive transitions coexist with standard transitions in the limit of f → 0, we show that this behavior is far more likely to occur naturally than was previously believed.

  13. Effects of synchronization treatments on ovarian follicular dynamics, corpus luteum growth, and circulating steroid hormone concentrations in lactating dairy cows.

    PubMed

    Herlihy, M M; Crowe, M A; Diskin, M G; Butler, S T

    2012-02-01

    Lactating dairy cows (n=57) ≥45 d postpartum at first service were enrolled in a randomized complete block design study to evaluate treatments to synchronize estrus and ovulation. At 10 d before artificial insemination (AI), animals were randomly assigned to 1 of 3 treatments: (1) d -10 GnRH (GnRH1; 10 μg of buserelin, i.m.) and controlled internal drug release insert [CIDR, 1.38 g of progesterone (P4)]; d -3 PGF(2α) (PGF; 25 mg of dinoprost, i.m.); d -2 CIDR out; and AI at observed estrus (CIDR_OBS); (2) same as CIDR_OBS, but GnRH (GnRH2) 36 h after CIDR out and timed AI (TAI) 18 h later (CIDR_TAI); or (3) same as CIDR_TAI, but no CIDR (Ovsynch). Transrectal ultrasound was used to assess follicle size before ovulation and on d 4, 8, and 15 after the presumptive day of estrus (d 0) to measure the corpus luteum (CL). Blood samples were collected to determine concentrations of estradiol (E2; d -10, -9, -3, -2, -1, and 0) and P4 (d -10, -9, -2, -1, 0, 1, 4, 6, 8, 11, and 15). No treatment differences were observed in either circulating concentrations of P4 or the ovulatory response to GnRH1 at the onset of synchronization treatments. Circulating concentrations of P4 were greater for CIDR_OBS and CIDR_TAI compared with Ovsynch at 24 h after CIDR insertion (5.34 and 4.98 vs. 1.75 ng/mL) and immediately before CIDR removal (1.65 and 1.48 vs. 0.40 ng/mL). Peak circulating concentrations of E2 were greater for CIDR_OBS compared with Ovsynch (3.85 vs. 2.39 pg/mL), but CIDR_TAI (2.82 pg/mL) did not differ from either CIDR_OBS or Ovsynch. The interval from PGF injection to peak circulating E2 did not differ between CIDR_TAI and Ovsynch (52.1 vs. 49.8 h). Both CIDR_TAI and Ovsynch, however, had shorter intervals from PGF injection to peak circulating E2 concentrations compared with CIDR_OBS (67.8 h). The diameter of the dominant follicle before ovulation was greater for CIDR_OBS compared with Ovsynch (18.5 vs. 16.0 mm) but CIDR_TAI (17.1 mm) did not differ from either of

  14. Nondestructive synchronous beam current monitor

    SciTech Connect

    Covo, Michel Kireeff

    2014-12-15

    A fast current transformer is mounted after the deflectors of the Berkeley 88-Inch Cyclotron. The measured signal is amplified and connected to the input of a lock-in amplifier. The lock-in amplifier performs a synchronous detection of the signal at the cyclotron second harmonic frequency. The magnitude of the signal detected is calibrated against a Faraday cup and corresponds to the beam intensity. It has exceptional resolution, long term stability, and can measure the beam current leaving the cyclotron as low as 1 nA.

  15. Synchronous Sampling for Distributed Experiments

    NASA Astrophysics Data System (ADS)

    Wittkamp, M.; Ettl, J.

    2015-09-01

    Sounding Rocket payloads, especially for atmospheric research, often consists of several independent sensors or experiments with different objectives. The data of these sensors can be combined in the post processing to improve the scientific results of the flight. One major requirement for this data-correlation is a common timeline for the measurements of the distributed experiments. Within this paper we present two ways to achieve absolute timing for asynchronously working experiments. The synchronization process is using the Global Positioning System (GPS) and a standard serial communication protocol for transport of timestamps and flight-states.

  16. Relevance of ovarian signaling for the early behavioral transition from estrus to pregnancy in the female rabbit.

    PubMed

    Hoffman, K L; González-Mariscal, G

    2007-11-01

    During estrus, the female domestic rabbit (Oryctolagus cuniculus) displays scent marking behavior (chinning), which is immediately inhibited after mating, temporarily recovers, and then declines and remains inhibited across pregnancy. Chinning is inhibited by progesterone (P) and the activation of the progesterone receptor (PR), but it is unlikely that P participates in the "acute" (immediate) or "early" inhibition of chinning (24 to 96 h post-mating, before plasma P levels rise). Since PR is activated in a ligand-independent manner by a variety of signaling molecules, some of which (e.g., GnRH) are also associated with reflexive ovulation in this species, we hypothesized that neurochemical/neuroendocrine signals associated with mating activate PR, resulting in the inhibition of chinning. In Experiment 1, we tested whether the PR antagonist, RU486 (20 mg, injected s.c. at -1 h, or at -7 h and +3 h relative to mating) prevented the post-mating inhibition of chinning in intact females. RU486 did not prevent the post-mating decline in chinning, indicating that PR activation associated with mating is not necessary for this effect. In Experiment 2, we used ovariectomized (OVX), estradiol benzoate (EB)-treated females to test the hypothesis that ovarian signaling is necessary for the post-mating inhibition of chinning. The acute inhibition of chinning occurred in OVX females, but the early inhibition was absent. We conclude that ovarian signaling is necessary for the early, but not acute, post-mating inhibition of chinning. The PR seems not to participate in either of these phases.

  17. Mutual synchronization of weakly coupled gyrotrons

    SciTech Connect

    Rozental, R. M.; Glyavin, M. Yu.; Sergeev, A. S.; Zotova, I. V.; Ginzburg, N. S.

    2015-09-15

    The processes of synchronization of two weakly coupled gyrotrons are studied within the framework of non-stationary equations with non-fixed longitudinal field structure. With the allowance for a small difference of the free oscillation frequencies of the gyrotrons, we found a certain range of parameters where mutual synchronization is possible while a high electronic efficiency is remained. It is also shown that synchronization regimes can be realized even under random fluctuations of the parameters of the electron beams.

  18. Desynchronization of stochastically synchronized chemical oscillators

    SciTech Connect

    Snari, Razan; Tinsley, Mark R. E-mail: kshowalt@wvu.edu; Faramarzi, Sadegh; Showalter, Kenneth E-mail: kshowalt@wvu.edu; Wilson, Dan; Moehlis, Jeff; Netoff, Theoden Ivan

    2015-12-15

    Experimental and theoretical studies are presented on the design of perturbations that enhance desynchronization in populations of oscillators that are synchronized by periodic entrainment. A phase reduction approach is used to determine optimal perturbation timing based upon experimentally measured phase response curves. The effectiveness of the perturbation waveforms is tested experimentally in populations of periodically and stochastically synchronized chemical oscillators. The relevance of the approach to therapeutic methods for disrupting phase coherence in groups of stochastically synchronized neuronal oscillators is discussed.

  19. Complexity and synchronization in stochastic chaotic systems

    NASA Astrophysics Data System (ADS)

    Son Dang, Thai; Palit, Sanjay Kumar; Mukherjee, Sayan; Hoang, Thang Manh; Banerjee, Santo

    2016-02-01

    We investigate the complexity of a hyperchaotic dynamical system perturbed by noise and various nonlinear speech and music signals. The complexity is measured by the weighted recurrence entropy of the hyperchaotic and stochastic systems. The synchronization phenomenon between two stochastic systems with complex coupling is also investigated. These criteria are tested on chaotic and perturbed systems by mean conditional recurrence and normalized synchronization error. Numerical results including surface plots, normalized synchronization errors, complexity variations etc show the effectiveness of the proposed analysis.

  20. Fertility of holstein dairy heifers after synchronization of ovulation and timed AI or AI after removed tail chalk.

    PubMed

    Rivera, H; Lopez, H; Fricke, P M

    2004-07-01

    Nonlactating Holstein dairy heifers (n=352) 13 mo of age were managed using a 42-d artificial insemination (AI) breeding period in which they received AI after removed tail chalk evaluated once daily. At AI breeding period onset (d 0), heifers were randomly assigned to receive synchronization of ovulation (100 microg of GnRH, d 0; 25 mg of PGF2alpha, d 6; 100 microg of GnRH, d 8) and timed AI (TAI; d 8) and AI after removed tail chalk for the entire AI breeding period (GPG; n=175), or AI after removed tail chalk for the entire AI breeding period (TC; n=177). As expected, 17.7% (31/175) of GPG heifers received AI after removed tail chalk before scheduled TAI. Pregnancy rate per artificial insemination (PR/AI) at approximately 30 d after first AI tended to be greater for TC (46.5%) than for GPG (38.3%) heifers. No treatment x inseminator interaction was detected; however, overall PR/AI was low for heifers in both treatments due to variation among the 3 inseminators (24.8, 30.0, and 58.0%). Pregnancy loss from approximately 30 to approximately 75 d after first AI was 10% and did not differ between treatments. Based on survival analysis, days to first AI was greater for TC than for GPG heifers, whereas days to pregnancy across the 42-d AI breeding period did not differ between treatments. Overall, 81.2% of GPG heifers receiving TAI synchronized luteal regression and ovulated within 48 h after the second GnRH injection. We conclude that this synchronization protocol can yield acceptable fertility in dairy heifers if AI to estrus is conducted between treatment with GnRH and PGF2alpha and AI efficiency is optimized. PMID:15328217

  1. Tape-recorded Lectures With Slide Synchronization

    ERIC Educational Resources Information Center

    Goodhue, D.

    1969-01-01

    Describes "Taped Explanation Slide Synchronization" programs used for individual study or group showing in college zoology. Discusses preparation of programs, class organization, equipment, and costs. (EB)

  2. Phase synchronization of two anharmonic nanomechanical oscillators.

    PubMed

    Matheny, Matthew H; Grau, Matt; Villanueva, Luis G; Karabalin, Rassul B; Cross, M C; Roukes, Michael L

    2014-01-10

    We investigate the synchronization of oscillators based on anharmonic nanoelectromechanical resonators. Our experimental implementation allows unprecedented observation and control of parameters governing the dynamics of synchronization. We find close quantitative agreement between experimental data and theory describing reactively coupled Duffing resonators with fully saturated feedback gain. In the synchronized state we demonstrate a significant reduction in the phase noise of the oscillators, which is key for sensor and clock applications. Our work establishes that oscillator networks constructed from nanomechanical resonators form an ideal laboratory to study synchronization--given their high-quality factors, small footprint, and ease of cointegration with modern electronic signal processing technologies. PMID:24483899

  3. Robustness of optimal synchronization in real networks.

    PubMed

    Ravoori, Bhargava; Cohen, Adam B; Sun, Jie; Motter, Adilson E; Murphy, Thomas E; Roy, Rajarshi

    2011-07-15

    Experimental studies can provide powerful insights into the physics of complex networks. Here, we report experimental results on the influence of connection topology on synchronization in fiber-optic networks of chaotic optoelectronic oscillators. We find that the recently predicted nonmonotonic, cusplike synchronization landscape manifests itself in the rate of convergence to the synchronous state. We also observe that networks with the same number of nodes, same number of links, and identical eigenvalues of the coupling matrix can exhibit fundamentally different approaches to synchronization. This previously unnoticed difference is determined by the degeneracy of associated eigenvectors in the presence of noise and mismatches encountered in real-world conditions. PMID:21838362

  4. Phase synchronization of two anharmonic nanomechanical oscillators.

    PubMed

    Matheny, Matthew H; Grau, Matt; Villanueva, Luis G; Karabalin, Rassul B; Cross, M C; Roukes, Michael L

    2014-01-10

    We investigate the synchronization of oscillators based on anharmonic nanoelectromechanical resonators. Our experimental implementation allows unprecedented observation and control of parameters governing the dynamics of synchronization. We find close quantitative agreement between experimental data and theory describing reactively coupled Duffing resonators with fully saturated feedback gain. In the synchronized state we demonstrate a significant reduction in the phase noise of the oscillators, which is key for sensor and clock applications. Our work establishes that oscillator networks constructed from nanomechanical resonators form an ideal laboratory to study synchronization--given their high-quality factors, small footprint, and ease of cointegration with modern electronic signal processing technologies.

  5. Calculation principles for a synchronous electromagnetic clutch

    NASA Technical Reports Server (NTRS)

    Panasenkov, M. A.

    1978-01-01

    A detailed explanation of the calculation principles, for a synchronous salient-pole electromagnetic clutch with lumped excitation windings is supplied by direct current. Practical recommendations are given.

  6. Pilotless Frame Synchronization Using LDPC Code Constraints

    NASA Technical Reports Server (NTRS)

    Jones, Christopher; Vissasenor, John

    2009-01-01

    A method of pilotless frame synchronization has been devised for low- density parity-check (LDPC) codes. In pilotless frame synchronization , there are no pilot symbols; instead, the offset is estimated by ex ploiting selected aspects of the structure of the code. The advantag e of pilotless frame synchronization is that the bandwidth of the sig nal is reduced by an amount associated with elimination of the pilot symbols. The disadvantage is an increase in the amount of receiver data processing needed for frame synchronization.

  7. Coupled lasers: phase versus chaos synchronization.

    PubMed

    Reidler, I; Nixon, M; Aviad, Y; Guberman, S; Friesem, A A; Rosenbluh, M; Davidson, N; Kanter, I

    2013-10-15

    The synchronization of chaotic lasers and the optical phase synchronization of light originating in multiple coupled lasers have both been extensively studied. However, the interplay between these two phenomena, especially at the network level, is unexplored. Here, we experimentally compare these phenomena by controlling the heterogeneity of the coupling delay times of two lasers. While chaotic lasers exhibit deterioration in synchronization as the time delay heterogeneity increases, phase synchronization is found to be independent of heterogeneity. The experimental results are found to be in agreement with numerical simulations for semiconductor lasers.

  8. Variety of synchronous regimes in neuronal ensembles

    NASA Astrophysics Data System (ADS)

    Komarov, M. A.; Osipov, G. V.; Suykens, J. A. K.

    2008-09-01

    We consider a Hodgkin-Huxley-type model of oscillatory activity in neurons of the snail Helix pomatia. This model has a distinctive feature: It demonstrates multistability in oscillatory and silent modes that is typical for the thalamocortical neurons. A single neuron cell can demonstrate a variety of oscillatory activity: Regular and chaotic spiking and bursting behavior. We study collective phenomena in small and large arrays of nonidentical cells coupled by models of electrical and chemical synapses. Two single elements coupled by electrical coupling show different types of synchronous behavior, in particular in-phase and antiphase synchronous regimes. In an ensemble of three inhibitory synaptically coupled elements, the phenomenon of sequential synchronous dynamics is observed. We study the synchronization phenomena in the chain of nonidentical neurons at different oscillatory behavior coupled with electrical and chemical synapses. Various regimes of phase synchronization are observed: (i) Synchronous regular and chaotic spiking; (ii) synchronous regular and chaotic bursting; and (iii) synchronous regular and chaotic bursting with different numbers of spikes inside the bursts. We detect and study the effect of collective synchronous burst generation due to the cluster formation and the oscillatory death.

  9. Synchronization and Partial Synchronization Experiments with Networks of Time-Delay Coupled Hindmarsh-Rose Neurons

    NASA Astrophysics Data System (ADS)

    Steur, Erik; Murguia, Carlos; Fey, Rob H. B.; Nijmeijer, Henk

    2016-06-01

    We study experimentally synchronization and partial synchronization in networks of Hindmarsh-Rose model neurons that interact through linear time-delay couplings. Our experimental setup consists of electric circuit board realizations of the Hindmarsh-Rose model neuron and a coupling interface in which the interaction between the circuits is defined. With this experimental setup we test the predictive value of theoretical results about synchronization and partial synchronization in networks.

  10. Effects of breed, age, season, and multiple ovulations on cyclic, PGF2α-induced, and postpartum estrus characteristics in Spanish jennies.

    PubMed

    Perez-Marin, C C; Galisteo, I; Perez-Rico, A; Galisteo, J

    2016-04-01

    This retrospective, population-based, cross-sectional study analyzed data for a total of 104 jennies reared in southern Spain over the period 1995 to 2014. Intervals to ovulation and incidence of multiple ovulation and pregnancy were charted for spontaneous, PGF2α-induced, and postpartum estrous cycles. In spontaneous estrous cycles, the interovulatory interval varied as a function of breed (P < 0.03) and month of ovulation (P < 0.01), and duration of estrus signs was longer in older jennies (0.04). Spontaneous cycles were also associated with higher ovulation rates from September to January (P < 0.006). When PGF2α was used to induce the estrus, not only did estrus signs last longer in old (P < 0.004) and in polyovular (0.02) jennies but old jennies also displayed significantly higher ovulation rates (P < 0.03). In postpartum jennies, no variations were observed as a function of any of the independent variables analyzed. Comparison of ovulation rates between different types of cycle revealed that postpartum jennies exhibited significantly lower ovulation rates (1.32 ± 0.07) and a lower incidence of multiple ovulation (30.4%) than spontaneous (1.62 ± 0.04, 55.0%) and PGF2α-induced (1.74 ± 0.08, 65.5%) groups. No differences were observed in the incidence of ovulation or pregnancy depending on the location of ovulation in polyovular cycles, and ovulation occurred at similar rates in the right and left ovaries. These findings shed further light on reproductive physiology in jennies and may be of value in improving animal management. PMID:26747577

  11. Gait synchronization in Caenorhabditis elegans

    PubMed Central

    Yuan, Jinzhou; Raizen, David M.; Bau, Haim H.

    2014-01-01

    Collective motion is observed in swarms of swimmers of various sizes, ranging from self-propelled nanoparticles to fish. The mechanisms that govern interactions among individuals are debated, and vary from one species to another. Although the interactions among relatively large animals, such as fish, are controlled by their nervous systems, the interactions among microorganisms, which lack nervous systems, are controlled through physical and chemical pathways. Little is known, however, regarding the mechanism of collective movements in microscopic organisms with nervous systems. To attempt to remedy this, we studied collective swimming behavior in the nematode Caenorhabditis elegans, a microorganism with a compact nervous system. We evaluated the contributions of hydrodynamic forces, contact forces, and mechanosensory input to the interactions among individuals. We devised an experiment to examine pair interactions as a function of the distance between the animals and observed that gait synchronization occurred only when the animals were in close proximity, independent of genes required for mechanosensation. Our measurements and simulations indicate that steric hindrance is the dominant factor responsible for motion synchronization in C. elegans, and that hydrodynamic interactions and genotype do not play a significant role. We infer that a similar mechanism may apply to other microscopic swimming organisms and self-propelled particles. PMID:24778261

  12. High accuracy time transfer synchronization

    NASA Technical Reports Server (NTRS)

    Wheeler, Paul J.; Koppang, Paul A.; Chalmers, David; Davis, Angela; Kubik, Anthony; Powell, William M.

    1995-01-01

    In July 1994, the U.S. Naval Observatory (USNO) Time Service System Engineering Division conducted a field test to establish a baseline accuracy for two-way satellite time transfer synchronization. Three Hewlett-Packard model 5071 high performance cesium frequency standards were transported from the USNO in Washington, DC to Los Angeles, California in the USNO's mobile earth station. Two-Way Satellite Time Transfer links between the mobile earth station and the USNO were conducted each day of the trip, using the Naval Research Laboratory(NRL) designed spread spectrum modem, built by Allen Osborne Associates(AOA). A Motorola six channel GPS receiver was used to track the location and altitude of the mobile earth station and to provide coordinates for calculating Sagnac corrections for the two-way measurements, and relativistic corrections for the cesium clocks. This paper will discuss the trip, the measurement systems used and the results from the data collected. We will show the accuracy of using two-way satellite time transfer for synchronization and the performance of the three HP 5071 cesium clocks in an operational environment.

  13. High accuracy time transfer synchronization

    NASA Astrophysics Data System (ADS)

    Wheeler, Paul J.; Koppang, Paul A.; Chalmers, David; Davis, Angela; Kubik, Anthony; Powell, William M.

    1995-05-01

    In July 1994, the U.S. Naval Observatory (USNO) Time Service System Engineering Division conducted a field test to establish a baseline accuracy for two-way satellite time transfer synchronization. Three Hewlett-Packard model 5071 high performance cesium frequency standards were transported from the USNO in Washington, DC to Los Angeles, California in the USNO's mobile earth station. Two-Way Satellite Time Transfer links between the mobile earth station and the USNO were conducted each day of the trip, using the Naval Research Laboratory(NRL) designed spread spectrum modem, built by Allen Osborne Associates(AOA). A Motorola six channel GPS receiver was used to track the location and altitude of the mobile earth station and to provide coordinates for calculating Sagnac corrections for the two-way measurements, and relativistic corrections for the cesium clocks. This paper will discuss the trip, the measurement systems used and the results from the data collected. We will show the accuracy of using two-way satellite time transfer for synchronization and the performance of the three HP 5071 cesium clocks in an operational environment.

  14. Coronal Modeling and Synchronic Maps

    NASA Astrophysics Data System (ADS)

    Linker, Jon A.; Lionello, R.; Mikic, Z.; Riley, P.; Downs, C.; Henney, C. J.; Arge, C.

    2013-07-01

    MHD simulations of the solar corona rely on maps of the solar magnetic field (typically measured at the photosphere) for input as boundary conditions. These "synoptic" maps (available from a number of ground-based and space-based solar observatories), which are perhaps better described as "diachronic," are built up over a solar rotation. A well-known problem with this approach is that the maps contain data that is as much as 27 days old. The Sun's magnetic flux is always evolving, and these changes in the flux affect coronal and heliospheric structure. Flux evolution models can in principle provide a more accurate specification, by estimating the likely state of the photospheric magnetic field on unobserved portions of the Sun. The Air Force Data Assimilative Photospheric flux Transport (ADAPT) model (Arge et al. 2010), which incorporates data assimilation techniques into the Worden and Harvey (2000) flux evolution model, is especially well-suited for this purpose. In this presentation we describe the use of such "synchronic" maps with coronal models. We compare results using synchronic maps versus the traditional synoptic maps. Research supported by AFOSR, NASA, and NSF.

  15. Synchronously pumped nuclear magnetic oscillator

    NASA Astrophysics Data System (ADS)

    Korver, Anna; Thrasher, Daniel; Bulatowicz, Michael; Walker, Thad

    2015-05-01

    We present progress towards a synchronously pumped nuclear magnetic oscillator. Alkali frequency shifts and quadrupole shifts are the dominant systematic effects in dual Xe isotope co-magnetometers. By synchronously pumping the Xe nuclei using spin-exchange with an oscillating Rb polarization, the Rb and Xe spins precess transverse to the longitudinal bias field. This configuration is predicted to be insensitive to first order quadrupole interactions and alkali spin-exchange frequency shifts. A key feature that allows co-precession of the Rb and Xe spins, despite a ~ 1000 fold ratio of their gyromagnetic ratios, is to apply the bias field in the form of a sequence of Rb 2 π pulses whose repetition frequency is equal to the Rb Larmor frequency. The 2 π pulses result in an effective Rb magnetic moment of zero, while the Xe precession depends only on the time average of the pulsed field amplitude. Polarization modulation of the pumping light at the Xe NMR frequency allows co-precession of the Rb and Xe spins. We will present our preliminary experimental studies of this new approach to NMR of spin-exchange pumped Xe. Support by the NSF and Northrop Grumman Co.

  16. Using Synchronous Technology to Enrich Student Learning

    ERIC Educational Resources Information Center

    Wang, Charles Xiaoxue; Jaeger, David; Liu, Jinxia; Guo, Xiaoning; Xie, Nan

    2013-01-01

    To explore the potential applications of synchronous technology to enrich student learning, faculty members from an American regional state university and a Chinese regional university collaborated to find appropriate ways to integrate synchronous technology (e.g., Adobe Connect) into an educational technology program in the American university…

  17. Examining Interactivity in Synchronous Virtual Classrooms

    ERIC Educational Resources Information Center

    Martin, Florence; Parker, Michele A.; Deale, Deborah F.

    2012-01-01

    Interaction is crucial to student satisfaction in online courses. Adding synchronous components (virtual classroom technologies) to online courses can facilitate interaction. In this study, interaction within a synchronous virtual classroom was investigated by surveying 21 graduate students in an instructional technology program in the…

  18. Synchronization Properties of Random Piecewise Isometries

    NASA Astrophysics Data System (ADS)

    Gorodetski, Anton; Kleptsyn, Victor

    2016-08-01

    We study the synchronization properties of the random double rotations on tori. We give a criterion that show when synchronization is present in the case of random double rotations on the circle and prove that it is always absent in dimensions two and higher.

  19. Interference, Integration and the Synchronic Fallacy.

    ERIC Educational Resources Information Center

    Mackey, William F.

    The purposes of this paper are to examine the effects of synchronic description in distinguishing between interference and integration in cases of language contact, and to suggest alternative methods of description suitable for the analysis of systems in motion. The "synchronic fallacy" is defined here as the belief that one can describe a…

  20. Quasars as very-accurate clock synchronizers

    NASA Technical Reports Server (NTRS)

    Hurd, W. J.; Goldstein, R. M.

    1975-01-01

    Quasars can be employed to synchronize global data communications, geophysical measurements, and atomic clocks. It is potentially two to three orders of magnitude better than presently-used Moon-bounce system. Comparisons between quasar and clock pulses are used to develop correction or synchronization factors for station clocks.

  1. Development of Network Synchronization Predicts Language Abilities.

    PubMed

    Doesburg, Sam M; Tingling, Keriann; MacDonald, Matt J; Pang, Elizabeth W

    2016-01-01

    Synchronization of oscillations among brain areas is understood to mediate network communication supporting cognition, perception, and language. How task-dependent synchronization during word production develops throughout childhood and adolescence, as well as how such network coherence is related to the development of language abilities, remains poorly understood. To address this, we recorded magnetoencephalography while 73 participants aged 4-18 years performed a verb generation task. Atlas-guided source reconstruction was performed, and phase synchronization among regions was calculated. Task-dependent increases in synchronization were observed in the theta, alpha, and beta frequency ranges, and network synchronization differences were observed between age groups. Task-dependent synchronization was strongest in the theta band, as were differences between age groups. Network topologies were calculated for brain regions associated with verb generation and were significantly associated with both age and language abilities. These findings establish the maturational trajectory of network synchronization underlying expressive language abilities throughout childhood and adolescence and provide the first evidence for an association between large-scale neurophysiological network synchronization and individual differences in the development of language abilities.

  2. Complete synchronization and generalized synchronization of one-way coupled time-delay systems.

    PubMed

    Zhan, Meng; Wang, Xingang; Gong, Xiaofeng; Wei, G W; Lai, C-H

    2003-09-01

    The complete synchronization and generalized synchronization (GS) of one-way coupled time-delay systems are studied. We find that GS can be achieved by a single scalar signal, and its synchronization threshold for different delay times shows the parameter resonance effect, i.e., we can obtain stable synchronization at a smaller coupling if the delay time of the driven system is chosen such that it is in resonance with the driving system. Near chaos synchronization, the desynchronization dynamics displays periodic bursts with the period equal to the delay time of the driven system. These features can be easily applied to the recovery of time-delay systems.

  3. An economic evaluation of estrous synchronization and timed artificial insemination in suckled beef cows.

    PubMed

    Rodgers, J C; Bird, S L; Larson, J E; Dilorenzo, N; Dahlen, C R; Dicostanzo, A; Lamb, G C

    2012-11-01

    Partial budget analysis was used to determine the economic outcome of estrus synchronization (ES) and timed artificial insemination (TAI) in commercial cow-calf production. Suckled beef cows (n = 1,197) from 8 locations were assigned randomly within each location to 1 of 2 treatment groups: 1) cows were inseminated artificially after synchronization of ovulation using the CO-Synch + CIDR protocol, which includes a 100-μg injection of GnRH (OvaCyst; TevaAnimal Health, St. Joseph, MO) when a controlled internal drug-releasing device (CIDR; Pfizer Animal Health, New York, NY) containing 1.38 g of progesterone was inserted. The CIDR was removed 7 d later, and cows received a 25-mg injection of PGF(2α) (PGF; Lutalyse; Pfizer Animal Health), followed in 66 h with TAI and a second 100-μg injection of GnRH (TAI; n = 582), and 2) cows were exposed to natural service (NS) without estrous synchronization (Control; n = 615). Within each herd, cows from both treatments were maintained together in similar pastures and were exposed to bulls 12 h after the last cow in the TAI treatment was inseminated. Overall, the percentage of cows exposed to treatments that subsequently weaned a calf was greater (P < 0.05) for TAI (84%) than Control (78%) cows. In addition, survival analysis demonstrated that cumulative calving distribution differed (P < 0.05) between the TAI and Control treatments. Weaning weights per cow exposed to treatments were greater (P < 0.01) for cows in the TAI treatment (193.4 ± 4.3 kg) than those cows in the Control treatment (175.9 ± 4.3 kg). Overall, increased returns plus decreased costs ($82.32) minus decreased returns plus increased costs ($33.18) resulted in a $49.14 advantage per exposed cow in the TAI treatment compared with the Control treatment. Location greatly influenced weaned calf weights, which may have been a result of differing management, nutrition, genetic selection, production goals, and environments. We concluded that ES and TAI had a

  4. Amplitude dynamics favors synchronization in complex networks

    NASA Astrophysics Data System (ADS)

    Gambuzza, Lucia Valentina; Gómez-Gardeñes, Jesus; Frasca, Mattia

    2016-04-01

    In this paper we study phase synchronization in random complex networks of coupled periodic oscillators. In particular, we show that, when amplitude dynamics is not negligible, phase synchronization may be enhanced. To illustrate this, we compare the behavior of heterogeneous units with both amplitude and phase dynamics and pure (Kuramoto) phase oscillators. We find that in small network motifs the behavior crucially depends on the topology and on the node frequency distribution. Surprisingly, the microscopic structures for which the amplitude dynamics improves synchronization are those that are statistically more abundant in random complex networks. Thus, amplitude dynamics leads to a general lowering of the synchronization threshold in arbitrary random topologies. Finally, we show that this synchronization enhancement is generic of oscillators close to Hopf bifurcations. To this aim we consider coupled FitzHugh-Nagumo units modeling neuron dynamics.

  5. Amplitude dynamics favors synchronization in complex networks

    PubMed Central

    Gambuzza, Lucia Valentina; Gómez-Gardeñes, Jesus; Frasca, Mattia

    2016-01-01

    In this paper we study phase synchronization in random complex networks of coupled periodic oscillators. In particular, we show that, when amplitude dynamics is not negligible, phase synchronization may be enhanced. To illustrate this, we compare the behavior of heterogeneous units with both amplitude and phase dynamics and pure (Kuramoto) phase oscillators. We find that in small network motifs the behavior crucially depends on the topology and on the node frequency distribution. Surprisingly, the microscopic structures for which the amplitude dynamics improves synchronization are those that are statistically more abundant in random complex networks. Thus, amplitude dynamics leads to a general lowering of the synchronization threshold in arbitrary random topologies. Finally, we show that this synchronization enhancement is generic of oscillators close to Hopf bifurcations. To this aim we consider coupled FitzHugh-Nagumo units modeling neuron dynamics. PMID:27108847

  6. Clustering versus non-clustering phase synchronizations

    SciTech Connect

    Liu, Shuai; Zhan, Meng

    2014-03-15

    Clustering phase synchronization (CPS) is a common scenario to the global phase synchronization of coupled dynamical systems. In this work, a novel scenario, the non-clustering phase synchronization (NPS), is reported. It is found that coupled systems do not transit to the global synchronization until a certain sufficiently large coupling is attained, and there is no clustering prior to the global synchronization. To reveal the relationship between CPS and NPS, we further analyze the noise effect on coupled phase oscillators and find that the coupled oscillator system can change from CPS to NPS with the increase of noise intensity or system disorder. These findings are expected to shed light on the mechanism of various intriguing self-organized behaviors in coupled systems.

  7. Synchronization of oscillators coupled through an environment

    NASA Astrophysics Data System (ADS)

    Katriel, Guy

    2008-11-01

    We study synchronization of oscillators that are indirectly coupled through their interaction with an environment. We give criteria for the stability or instability of a synchronized oscillation. Using these criteria we investigate synchronization of systems of oscillators which are weakly coupled, in the sense that the influence of the oscillators on the environment is weak. We prove that arbitrarily weak coupling will synchronize the oscillators, provided that this coupling is of the ‘right’ sign. We illustrate our general results by applications to a model of coupled GnRH neuron oscillators proposed by Khadra and Li [A. Khadra, Y.X. Li, A model for the pulsatile secretion of gonadotropin-releasing hormone from synchronized hypothalamic neurons, Biophys. J. 91 (2006) 74-83.], and to indirectly weakly-coupled λ- ω oscillators.

  8. Hydrodynamic synchronization of colloidal oscillators

    PubMed Central

    Kotar, Jurij; Leoni, Marco; Bassetti, Bruno; Lagomarsino, Marco Cosentino; Cicuta, Pietro

    2010-01-01

    Two colloidal spheres are maintained in oscillation by switching the position of an optical trap when a sphere reaches a limit position, leading to oscillations that are bounded in amplitude but free in phase and period. The interaction between the oscillators is only through the hydrodynamic flow induced by their motion. We prove that in the absence of stochastic noise the antiphase dynamical state is stable, and we show how the period depends on coupling strength. Both features are observed experimentally. As the natural frequencies of the oscillators are made progressively different, the coordination is quickly lost. These results help one to understand the origin of hydrodynamic synchronization and how the dynamics can be tuned. Cilia and flagella are biological systems coupled hydrodynamically, exhibiting dramatic collective motions. We propose that weakly correlated phase fluctuations, with one of the oscillators typically precessing the other, are characteristic of hydrodynamically coupled systems in the presence of thermal noise. PMID:20385848

  9. Pulse code modulated signal synchronizer

    NASA Technical Reports Server (NTRS)

    Kobayashi, H. S. (Inventor)

    1974-01-01

    A bit synchronizer for a split phase PCM transmission is reported that includes three loop circuits which receive incoming phase coded PCM signals. In the first loop, called a Q-loop, a generated, phase coded, PCM signal is multiplied with the incoming signals, and the frequency and phase of the generated signal are nulled to that of the incoming subcarrier signal. In the second loop, called a B-loop, a circuit multiplies a generated signal with incoming signals to null the phase of the generated signal in a bit phase locked relationship to the incoming signal. In a third loop, called the I-loop, a phase coded PCM signal is multiplied with the incoming signals for decoding the bit information from the PCM signal. A counter means is used for timing of the generated signals and timing of sample intervals for each bit period.

  10. Collapse of Synchronization in a Memristive Network

    NASA Astrophysics Data System (ADS)

    Lü, Mi; Wang, Chun-Ni; Tang, Jun; Ma, Jun

    2015-12-01

    For an oscillating circuit or coupled circuits, damage in electric devices such as inductor, resistance, memristor even capacitor can cause breakdown or collapse of the circuits. These damage could be associated with external attack or aging in electric devices, and then the bifurcation parameters could be deformed from normal values. Resonators or signal generators are often synchronized to produce powerful signal series and this problem could be investigated by using synchronization in network. Complete synchronization could be induced by linear coupling in a two-dimensional network of identical oscillators when the coupling intensity is beyond certain threshold. The collective behavior and synchronization state are much dependent on the bifurcation parameters. Any slight fluctuation in parameter and breakdown in bifurcation parameter can cause transition of synchronization even collapse of synchronization in the network. In this paper, a two-dimensional network composed of the resonators coupled with memristors under nearest-neighbor connection is designed, and the network can reach complete synchronization by carefully selecting coupling intensity. The network keeps synchronization after certain transient period, then a bifurcation parameter in a resonator is switched from the previous value and the adjacent resonators (oscillators) are affected in random. It is found that the synchronization area could be invaded greatly in a diffusive way. The damage area size is much dependent on the selection of diffusive period of damage and deformation degree in the parameter. Indeed, the synchronization area could keep intact at largest size under intermediate deformation degree and coupling intensity. Supported by the National Natural Science of China under Grant Nos. 11265008 and 11365014

  11. Technical note: use of slow-release estradiol and prostaglandin F2alpha to induce pseudopregnancy and control estrus in gilts.

    PubMed

    Cushman, R A; Davis, P E; Boonyaprakob, U; Hedgpeth, V S; Burns, P J; Britt, J H

    1999-11-01

    We determined whether a single injection of slow-release estradiol-17beta (SRE2) would induce pseudopregnancy in gilts and whether PGF2alpha would regress the corpora lutea (CL) of pseudopregnancy. Crossbred gilts (n = 40) were induced to ovulate by treatment with 400 IU of hCG + 200 IU of eCG (PG600, Intervet, Millsboro, DE) given at 180 d of age (d = 0). On d 14, gilts were injected i.m. with one of five doses (n = 8 gilts/dose) of SRE2 (0, 12.5, 25, 50, or 100 mg). Blood samples were collected before SRE2 and twice weekly until d 73 to monitor serum progesterone (P4) and estradiol (E2). On d 59, gilts received (i.m.) 10 mg of PGF2alpha (Lutalyse, Pharmacia Upjohn, Kalamazoo, MI) and were checked for estrus for 7 d. On d 62, mammary development was scored (0 = no development; 1 = some development; 2 = teat and gland development) by a neutral observer. Treatment with SRE2 increased (P < .05) peak E2 concentrations, duration of luteal function, and mammary gland score. There were no differences (chi-square, P > .05) among doses of SRE2 in the percentage of pseudopregnant gilts that showed luteolysis after PGF2alpha. We conclude that a single injection of SRE2 can induce pseudopregnancy and that the CL can be regressed with PGF2alpha, providing a simple method for controlling estrus in gilts.

  12. V123 BEAM SYNCHRONOUS ENCODER MODULE.

    SciTech Connect

    KERNER,T.; CONKLING,C.R.; OERTER,B.

    1999-03-29

    The V123 Synchronous Encoder Module transmits events to distributed trigger modules and embedded decoders around the RHIC rings where they are used to provide beam instrumentation triggers [1,2,3]. The RHIC beam synchronous event link hardware is mainly comprised of three VMEbus board designs, the central input modules (V201), and encoder modules (V123), and the distributed trigger modules (V124). Two beam synchronous links, one for each ring, are distributed via fiber optics and fanned out via twisted wire pair cables. The V123 synchronizes with the RF system clock derived from the beam bucket frequency and a revolution fiducial pulse. The RF system clock is used to create the beam synchronous event link carrier and events are synchronized with the rotation fiducial. A low jitter RF clock is later recovered from this carrier by phase lock loops in the trigger modules. Prioritized hardware and software triggers fill up to 15 beam event code transmission slots per revolution while tracking the ramping RF acceleration frequency and storage frequency. The revolution fiducial event is always the first event transmitted which is used to synchronize the firing of the abort kicker and to locate the first bucket for decoders distributed about the ring.

  13. System Synchronizes Recordings from Separated Video Cameras

    NASA Technical Reports Server (NTRS)

    Nail, William; Nail, William L.; Nail, Jasper M.; Le, Doung T.

    2009-01-01

    A system of electronic hardware and software for synchronizing recordings from multiple, physically separated video cameras is being developed, primarily for use in multiple-look-angle video production. The system, the time code used in the system, and the underlying method of synchronization upon which the design of the system is based are denoted generally by the term "Geo-TimeCode(TradeMark)." The system is embodied mostly in compact, lightweight, portable units (see figure) denoted video time-code units (VTUs) - one VTU for each video camera. The system is scalable in that any number of camera recordings can be synchronized. The estimated retail price per unit would be about $350 (in 2006 dollars). The need for this or another synchronization system external to video cameras arises because most video cameras do not include internal means for maintaining synchronization with other video cameras. Unlike prior video-camera-synchronization systems, this system does not depend on continuous cable or radio links between cameras (however, it does depend on occasional cable links lasting a few seconds). Also, whereas the time codes used in prior video-camera-synchronization systems typically repeat after 24 hours, the time code used in this system does not repeat for slightly more than 136 years; hence, this system is much better suited for long-term deployment of multiple cameras.

  14. Periodic and aperiodic synchronization in skilled action.

    PubMed

    Cummins, Fred

    2011-01-01

    Synchronized action is considered as a manifestation of shared skill. Most synchronized behaviors in humans and other animals are based on periodic repetition. Aperiodic synchronization of complex action is found in the experimental task of synchronous speaking, in which naive subjects read a common text in lock step. The demonstration of synchronized behavior without a periodic basis is presented as a challenge for theoretical understanding. A unified treatment of periodic and aperiodic synchronization is suggested by replacing the sequential processing model of cognitivist approaches with the more local notion of a task-specific sensorimotor coordination. On this view, skilled action is the imposition of constraints on the co-variation of movement and sensory flux such that the boundary conditions that define the skill are met. This non-cognitivist approach originates in the work of John Dewey. It allows a unification of the treatment of sensorimotor synchronization in simple rhythmic behavior and in complex skilled behavior and it suggests that skill sharing is a uniquely human trait of considerable import.

  15. Transition to complete synchronization and global intermittent synchronization in an array of time-delay systems.

    PubMed

    Suresh, R; Senthilkumar, D V; Lakshmanan, M; Kurths, J

    2012-07-01

    We report the nature of transitions from the nonsynchronous to a complete synchronization (CS) state in arrays of time-delay systems, where the systems are coupled with instantaneous diffusive coupling. We demonstrate that the transition to CS occurs distinctly for different coupling configurations. In particular, for unidirectional coupling, locally (microscopically) synchronization transition occurs in a very narrow range of coupling strength but for a global one (macroscopically) it occurs sequentially in a broad range of coupling strength preceded by an intermittent synchronization. On the other hand, in the case of mutual coupling, a very large value of coupling strength is required for local synchronization and, consequently, all the local subsystems synchronize immediately for the same value of the coupling strength and, hence, globally, synchronization also occurs in a narrow range of the coupling strength. In the transition regime, we observe a type of synchronization transition where long intervals of high-quality synchronization which are interrupted at irregular times by intermittent chaotic bursts simultaneously in all the systems and which we designate as global intermittent synchronization. We also relate our synchronization transition results to the above specific types using unstable periodic orbit theory. The above studies are carried out in a well-known piecewise linear time-delay system.

  16. Transition to complete synchronization and global intermittent synchronization in an array of time-delay systems

    NASA Astrophysics Data System (ADS)

    Suresh, R.; Senthilkumar, D. V.; Lakshmanan, M.; Kurths, J.

    2012-07-01

    We report the nature of transitions from the nonsynchronous to a complete synchronization (CS) state in arrays of time-delay systems, where the systems are coupled with instantaneous diffusive coupling. We demonstrate that the transition to CS occurs distinctly for different coupling configurations. In particular, for unidirectional coupling, locally (microscopically) synchronization transition occurs in a very narrow range of coupling strength but for a global one (macroscopically) it occurs sequentially in a broad range of coupling strength preceded by an intermittent synchronization. On the other hand, in the case of mutual coupling, a very large value of coupling strength is required for local synchronization and, consequently, all the local subsystems synchronize immediately for the same value of the coupling strength and, hence, globally, synchronization also occurs in a narrow range of the coupling strength. In the transition regime, we observe a type of synchronization transition where long intervals of high-quality synchronization which are interrupted at irregular times by intermittent chaotic bursts simultaneously in all the systems and which we designate as global intermittent synchronization. We also relate our synchronization transition results to the above specific types using unstable periodic orbit theory. The above studies are carried out in a well-known piecewise linear time-delay system.

  17. Physiological Synchronization in a Vigilance Dual Task.

    PubMed

    Guastello, Stephen J

    2016-01-01

    The synchronization of autonomic arousal levels and other physio-logical responses between people is a potentially important component of work team performance, client-therapist relationships, and other types of human interaction. This study addressed several problems: What statistical models are viable for identifying synchronization for loosely coupled human systems? How is the level of synchronization related to psychosocial variables such as empathy, subjective ratings of workload, and actual performance? Participants were 70 undergraduates who worked in pairs on a vigilance dual task in which they watched a virtual reality security camera, rang a bell when they saw the target intruder, and completed a jig-saw puzzle. Event rates either increased or decreased during the 90 min work period. The average R2 values for each person were .66, .66, .62, and .53 for the linear autoregressive model, linear autoregressive model with a synchronization component, the nonlinear autoregressive model, and the nonlinear autoregressive model with a synchronization component, respectively. All models were more accurate at a lag of 20 sec compared to 50 sec or customized lag lengths. Although the linear models were more accurate overall, the nonlinear synchronization parameters were more often related to psychological variables and performance. In particular, greater synchronization was observed with the nonlinear model when the target event rate increased, compared to when it decreased, which was expected from the general theory of synchronization. Nonlinear models were also more effective for uncovering inhibitory or dampening relationships between the co-workers as well as mutually excitatory relationships. Future research should explore the comparative model results for tasks that induce higher levels of synchronization and involve different types of internal group coordination.

  18. Synchronization of Boolean Networks with Different Update Schemes.

    PubMed

    Zhang, Hao; Wang, Xingyuan; Lin, Xiaohui

    2014-01-01

    In this paper, the synchronizations of Boolean networks with different update schemes (synchronized Boolean networks and asynchronous Boolean networks) are investigated. All nodes in Boolean network are represented in terms of semi-tensor product. First, we give the concept of inner synchronization and observe that all nodes in a Boolean network are synchronized with each other. Second, we investigate the outer synchronization between a driving Boolean network and a corresponding response Boolean network. We provide not only the concept of traditional complete synchronization, but also the anti-synchronization and get the anti-synchronization in simulation. Third, we extend the outer synchronization to asynchronous Boolean network and get the complete synchronization between an asynchronous Boolean network and a response Boolean network. Consequently, theorems for synchronization of Boolean networks and asynchronous Boolean networks are derived. Examples are provided to show the correctness of our theorems.

  19. Synchronous Behavior of Two Coupled Biological Neurons

    SciTech Connect

    Elson, R.C.; Selverston, A.I.; Elson, R.C.; Selverston, A.I.; Huerta, R.; Rulkov, N.F.; Rabinovich, M.I.; Abarbanel, H.D.; Selverston, A.I.; Huerta, R.; Abarbanel, H.D.

    1998-12-01

    We report experimental studies of synchronization phenomena in a pair of biological neurons that interact through naturally occurring, electrical coupling. When these neurons generate irregular bursts of spikes, the natural coupling synchronizes slow oscillations of membrane potential, but not the fast spikes. By adding artificial electrical coupling we studied transitions between synchrony and asynchrony in both slow oscillations and fast spikes. We discuss the dynamics of bursting and synchronization in living neurons with distributed functional morphology. {copyright} {ital 1998} {ital The American Physical Society}

  20. Synchronization of eukaryotic cells by periodic forcing.

    PubMed

    Battogtokh, Dorjsuren; Aihara, Kazuyuki; Tyson, John J

    2006-04-14

    We study a cell population described by a minimal mathematical model of the eukaryotic cell cycle subject to periodic forcing that simultaneously perturbs the dynamics of the cell cycle engine and cell growth, and we show that the population can be synchronized in a mode-locked regime. By simplifying the model to two variables, for the phase of cell cycle progression and the mass of the cell, we calculate the Lyapunov exponents to obtain the parameter window for synchronization. We also discuss the effects of intrinsic mitotic fluctuations, asymmetric division, and weak mutual coupling on the pace of synchronization. PMID:16712125

  1. Multistability of synchronous regimes in rotator ensembles.

    PubMed

    Kryukov, A K; Petrov, V S; Osipov, G V; Kurths, J

    2015-12-01

    We study collective dynamics in rotator ensembles and focus on the multistability of synchronous regimes in a chain of coupled rotators. We provide a detailed analysis of the number of coexisting regimes and estimate in particular, the synchronization boundary for different types of individual frequency distribution. The number of wave-based regimes coexisting for the same parameters and its dependence on the chain length are estimated. We give an analytical estimation for the synchronization frequency of the in-phase regime for a uniform individual frequency distribution. PMID:26723160

  2. Quantum Clock Synchronization with a Single Qudit

    PubMed Central

    Tavakoli, Armin; Cabello, Adán; Żukowski, Marek; Bourennane, Mohamed

    2015-01-01

    Clock synchronization for nonfaulty processes in multiprocess networks is indispensable for a variety of technologies. A reliable system must be able to resynchronize the nonfaulty processes upon some components failing causing the distribution of incorrect or conflicting information in the network. The task of synchronizing such networks is related to Byzantine agreement (BA), which can classically be solved using recursive algorithms if and only if less than one-third of the processes are faulty. Here we introduce a nonrecursive quantum algorithm, based on a quantum solution of the detectable BA, which achieves clock synchronization in the presence of arbitrary many faulty processes by using only a single quantum system. PMID:25613754

  3. Quantum clock synchronization with a single qudit.

    PubMed

    Tavakoli, Armin; Cabello, Adán; Żukowski, Marek; Bourennane, Mohamed

    2015-01-23

    Clock synchronization for nonfaulty processes in multiprocess networks is indispensable for a variety of technologies. A reliable system must be able to resynchronize the nonfaulty processes upon some components failing causing the distribution of incorrect or conflicting information in the network. The task of synchronizing such networks is related to Byzantine agreement (BA), which can classically be solved using recursive algorithms if and only if less than one-third of the processes are faulty. Here we introduce a nonrecursive quantum algorithm, based on a quantum solution of the detectable BA, which achieves clock synchronization in the presence of arbitrary many faulty processes by using only a single quantum system.

  4. Quantum Clock Synchronization with a Single Qudit

    NASA Astrophysics Data System (ADS)

    Tavakoli, Armin; Cabello, Adán; Żukowski, Marek; Bourennane, Mohamed

    2015-01-01

    Clock synchronization for nonfaulty processes in multiprocess networks is indispensable for a variety of technologies. A reliable system must be able to resynchronize the nonfaulty processes upon some components failing causing the distribution of incorrect or conflicting information in the network. The task of synchronizing such networks is related to Byzantine agreement (BA), which can classically be solved using recursive algorithms if and only if less than one-third of the processes are faulty. Here we introduce a nonrecursive quantum algorithm, based on a quantum solution of the detectable BA, which achieves clock synchronization in the presence of arbitrary many faulty processes by using only a single quantum system.

  5. Synchronization regimes in conjugate coupled chaotic oscillators.

    PubMed

    Karnatak, Rajat; Ramaswamy, Ram; Prasad, Awadhesh

    2009-09-01

    Nonlinear oscillators that are mutually coupled via dissimilar (or conjugate) variables display distinct regimes of synchronous behavior. In identical chaotic oscillators diffusively coupled in this manner, complete synchronization occurs only by chaos suppression when the coupled subsystems drive each other into a regime of periodic dynamics. Furthermore, the coupling does not vanish but acts as an "internal" drive. When the oscillators are mismatched, phase synchronization occurs, while in a master slave configuration, generalized synchrony results. These effects are demonstrated in a system of coupled chaotic Rossler oscillators.

  6. Paths to synchronization on complex networks.

    PubMed

    Gómez-Gardeñes, Jesús; Moreno, Yamir; Arenas, Alex

    2007-01-19

    The understanding of emergent collective phenomena in natural and social systems has driven the interest of scientists from different disciplines during decades. Among these phenomena, the synchronization of a set of interacting individuals or units has been intensively studied because of its ubiquity in the natural world. In this Letter, we show how for fixed coupling strengths local patterns of synchronization emerge differently in homogeneous and heterogeneous complex networks, driving the process towards a certain global synchronization degree following different paths. The dependence of the dynamics on the coupling strength and on the topology is unveiled. This study provides a new perspective and tools to understand this emerging phenomena. PMID:17358685

  7. Enhancing synchronization based on complex gradient networks.

    PubMed

    Wang, Xingang; Lai, Ying-Cheng; Lai, Choy Heng

    2007-05-01

    The ubiquity of scale-free networks in nature and technological applications and the finding that such networks may be more difficult to synchronize than homogeneous networks pose an interesting phenomenon for study in network science. We argue and demonstrate that, in the presence of some proper gradient fields, scale-free networks can be more synchronizable than homogeneous networks. The gradient structure can in fact arise naturally in any weighted and asymmetrical networks; based on this we propose a coupling scheme that permits effective synchronous dynamics on the network. The synchronization scheme is verified by eigenvalue analysis and by direct numerical simulations using networks of nonidentical chaotic oscillators. PMID:17677146

  8. Conditional ramsey spectroscopy with synchronized atoms.

    PubMed

    Xu, Minghui; Holland, M J

    2015-03-13

    We investigate Ramsey spectroscopy performed on a synchronized ensemble of two-level atoms. The synchronization is induced by the collective coupling of the atoms to a heavily damped mode of an optical cavity. We show that, in principle, with this synchronized system it is possible to observe Ramsey fringes indefinitely, even in the presence of spontaneous emission and other sources of individual-atom dephasing. This could have important consequences for atomic clocks and a wide range of precision metrology applications. PMID:25815931

  9. Using GLONASS signal for clock synchronization

    NASA Technical Reports Server (NTRS)

    Gouzhva, Yuri G.; Gevorkyan, Arvid G.; Bogdanov, Pyotr P.; Ovchinnikov, Vitaly V.

    1994-01-01

    Although in accuracy parameters GLONASS is correlated with GPS, using GLONASS signals for high-precision clock synchronization was, up to the recent time, of limited utility due to the lack of specialized time receivers. In order to improve this situation, in late 1992 the Russian Institute of Radionavigation and Time (RMT) began to develop a GLONASS time receiver using as a basis the airborne ASN-16 receiver. This paper presents results of estimating user clock synchronization accuracy via GLONASS signals using ASN-16 receiver in the direct synchronization and common-view modes.

  10. Synchronization Phenomena and Epoch Filter of Electroencephalogram

    NASA Astrophysics Data System (ADS)

    Matani, Ayumu

    Nonlinear electrophysiological synchronization phenomena in the brain, such as event-related (de)synchronization, long distance synchronization, and phase-reset, have received much attention in neuroscience over the last decade. These phenomena contain more electrical than physiological keywords and actually require electrical techniques to capture with electroencephalography (EEG). For instance, epoch filters, which have just recently been proposed, allow us to investigate such phenomena. Moreover, epoch filters are still developing and would hopefully generate a new paradigm in neuroscience from an electrical engineering viewpoint. Consequently, electrical engineers could be interested in EEG once again or from now on.

  11. Synchronization System for Next Generation Light Sources

    SciTech Connect

    Zavriyev, Anton

    2014-03-27

    An alternative synchronization technique – one that would allow explicit control of the pulse train including its repetition rate and delay is clearly desired. We propose such a scheme. Our method is based on optical interferometry and permits synchronization of the pulse trains generated by two independent mode-locked lasers. As the next generation x-ray sources will be driven by a clock signal derived from a mode-locked optical source, our technique will provide a way to synchronize x-ray probe with the optical pump pulses.

  12. Complex Synchronization Phenomena in Ecological Systems

    NASA Astrophysics Data System (ADS)

    Stone, Lewi; Olinky, Ronen; Blasius, Bernd; Huppert, Amit; Cazelles, Bernard

    2002-07-01

    Ecological and biological systems provide us with many striking examples of synchronization phenomena. Here we discuss a number of intriguing cases and attempt to explain them taking advantage of a modelling framework. One main focus will concern synchronized ecological end epidemiological cycles which have Uniform Phase growth associated with their regular recurrence, and Chaotic Amplitudes - a feature we term UPCA. Examples come from different areas and include decadal cycles of small mammals, recurrent viral epidemics such as childhood infections (eg., measles), and seasonally driven phytoplankton blooms observed in lakes and the oceans. A more detailed theoretical analysis of seasonally synchronized chaotic population cycles is presented.

  13. Synchronization Analysis of Nonstationary Bivariate Time Series

    NASA Astrophysics Data System (ADS)

    Kurths, J.

    First the concept of synchronization in coupled complex systems is presented and it is shown that synchronization phenomena are abundant in science, nature, engineer- ing etc. We use this concept to treat the inverse problem and to reveal interactions between oscillating systems from observational data. First it is discussed how time varying phases and frequencies can be estimated from time series and second tech- niques for detection and quantification of hidden synchronization is presented. We demonstrate that this technique is effective for the analysis of systems' interrelation from noisy nonstationary bivariate data and provides other insights than traditional cross correlation and spectral analysis. For this, model examples and geophysical data are discussed.

  14. Temperature synchronized molecular layer epitaxy

    NASA Astrophysics Data System (ADS)

    Kurabayashi, T.; Nishizawa, J.

    1994-12-01

    This paper reports the first results on a modified molecular layer epitaxy (MLE) technique to deposit epitaxial GaAs films by changing the substrate temperature for alternate TEG (or TMG) and AsH 3 injection. This method of temperature synchronized molecular layer epitaxy (TSMLE) is a new concept for MLE and atomic layer epitaxy (ALE). The growth rates and the doping phenomena showed different characteristics to the conventional methods which were performed at a constant temperature. This method was effective not only for the study of monolayer growth, but also for device application, especially for the heavily doped p-type layer of which carrier concentration is 10 20 cm -3 order. Carbon doped p-type layer was achieved by TMG-AsH 3 TSMLE. The carbon concentration increased by decreasing the temperature during AsH 3 injection and by increasing the temperature during TMG injection. Zn-doped layer was achieved by TEG-AsH 3 TSMLE using DEZn as a dopant gas for p-type layer fabrication. To doped heavily, DEZn injected after AsH 3 injection and the temperature during AsH 3 injection had a suitable value at 393°C.

  15. Transition from anticipatory to lag synchronization via complete synchronization in time-delay systems.

    PubMed

    Senthilkumar, D V; Lakshmanan, M

    2005-01-01

    The existence of anticipatory, complete, and lag synchronization in a single system having two different time delays, that is, feedback delay tau1 and coupling delay tau2, is identified. The transition from anticipatory to complete synchronization and from complete to lag synchronization as a function of coupling delay tau2 with a suitable stability condition is discussed. In particular, it is shown that the stability condition is independent of the delay times tau1 and tau2. Consequently, for a fixed set of parameters, all the three types of synchronizations can be realized. Further, the emergence of exact anticipatory, complete, or lag synchronization from the desynchronized state via approximate synchronization, when one of the system parameters (b2) is varied, is characterized by a minimum of the similarity function and the transition from on-off intermittency via periodic structure in the laminar phase distribution.

  16. High Efficiency Synchronous Rectification in Spacecraft

    NASA Technical Reports Server (NTRS)

    Krauhamer, S.; Das, R.; Vorperian, V.; White, J.; Bennett, J.; Rogers, D.

    1993-01-01

    This paper examines the implementaion of MOSFETs as synchronous rectifiers which results in a substantial improvement in power processing efficency and therefore may result in significant reduction of spacecraft mass and volum for the same payload.

  17. Controlling synchronous patterns in complex networks.

    PubMed

    Lin, Weijie; Fan, Huawei; Wang, Ying; Ying, Heping; Wang, Xingang

    2016-04-01

    Although the set of permutation symmetries of a complex network could be very large, few of them give rise to stable synchronous patterns. Here we present a general framework and develop techniques for controlling synchronization patterns in complex network of coupled chaotic oscillators. Specifically, according to the network permutation symmetry, we design a small-size and weighted network, namely the control network, and use it to control the large-size complex network by means of pinning coupling. We argue mathematically that for any of the network symmetries, there always exists a critical pinning strength beyond which the unstable synchronous pattern associated to this symmetry can be stabilized. The feasibility of the control method is verified by numerical simulations of both artificial and real-world networks and demonstrated experimentally in systems of coupled chaotic circuits. Our studies show the controllability of synchronous patterns in complex networks of coupled chaotic oscillators.

  18. Synchronization in chaotic oscillators by cyclic coupling

    NASA Astrophysics Data System (ADS)

    Olusola, O. I.; Njah, A. N.; Dana, S. K.

    2013-07-01

    We introduce a type of cyclic coupling to investigate synchronization of chaotic oscillators. We derive analytical solutions of the critical coupling for stable synchronization under the cyclic coupling for the Rössler system and the Lorenz oscillator as paradigmatic illustration. Based on the master stability function (MSF) approach, the analytical results on critical coupling are verified numerically. An enhancing effect in terms of lowering the critical coupling or enlarging the synchronization window in a critical coupling space is noticed. The cyclic coupling is also applied in other models, Hindmarsh-Rose model, Sprott system, Chen system and forced Duffing system to confirm the enhancing effect. The cyclic coupling allows tuning of two coupling constants in reverse directions when an optimal control of synchronization is feasible.

  19. Synchronous correlation matrices and Connes' embedding conjecture

    NASA Astrophysics Data System (ADS)

    Dykema, Kenneth J.; Paulsen, Vern

    2016-01-01

    In the work of Paulsen et al. [J. Funct. Anal. (in press); preprint arXiv:1407.6918], the concept of synchronous quantum correlation matrices was introduced and these were shown to correspond to traces on certain C*-algebras. In particular, synchronous correlation matrices arose in their study of various versions of quantum chromatic numbers of graphs and other quantum versions of graph theoretic parameters. In this paper, we develop these ideas further, focusing on the relations between synchronous correlation matrices and microstates. We prove that Connes' embedding conjecture is equivalent to the equality of two families of synchronous quantum correlation matrices. We prove that if Connes' embedding conjecture has a positive answer, then the tracial rank and projective rank are equal for every graph. We then apply these results to more general non-local games.

  20. Method and system for downhole clock synchronization

    DOEpatents

    Hall, David R.; Bartholomew, David B.; Johnson, Monte; Moon, Justin; Koehler, Roger O.

    2006-11-28

    A method and system for use in synchronizing at least two clocks in a downhole network are disclosed. The method comprises determining a total signal latency between a controlling processing element and at least one downhole processing element in a downhole network and sending a synchronizing time over the downhole network to the at least one downhole processing element adjusted for the signal latency. Electronic time stamps may be used to measure latency between processing elements. A system for electrically synchronizing at least two clocks connected to a downhole network comprises a controlling processing element connected to a synchronizing clock in communication over a downhole network with at least one downhole processing element comprising at least one downhole clock. Preferably, the downhole network is integrated into a downhole tool string.

  1. Remote bistatic receiver synchronization using DLL techniques

    NASA Astrophysics Data System (ADS)

    Aguasca, A.; Broquetas, A.; Fdez de Muniain, J.; Ambros, A.

    An experimental staggered pulse repetition frequency synchronizer, based on a delay-lock loop (DLL) was tested using a transmitter signal simulator that simulates the staggering sequence windowed by the antenna beam. The measured system performance ensures synchronization with a 30-ms direct illumination, with an accumulated delay error in the order of the resolution cell positioning error in range. An artificial time expansion of the received pulses is performed in order to reduce the acquisition time synchronization. A bistatic radar synchronization method based on DLL was is analyzed by linearization of the different parts and signals involved. The parameters that degrade system performance are obtained. And some solutions are represented in order to minimize their effects.

  2. Dynamic visuomotor synchronization: quantification of predictive timing.

    PubMed

    Maruta, Jun; Heaton, Kristin J; Kryskow, Elisabeth M; Maule, Alexis L; Ghajar, Jamshid

    2013-03-01

    When a moving target is tracked visually, spatial and temporal predictions are used to circumvent the neural delay required for the visuomotor processing. In particular, the internally generated predictions must be synchronized with the external stimulus during continuous tracking. We examined the utility of a circular visual-tracking paradigm for assessment of predictive timing, using normal human subjects. Disruptions of gaze-target synchronization were associated with anticipatory saccades that caused the gaze to be temporarily ahead of the target along the circular trajectory. These anticipatory saccades indicated preserved spatial prediction but suggested impaired predictive timing. We quantified gaze-target synchronization with several indices, whose distributions across subjects were such that instances of extremely poor performance were identifiable outside the margin of error determined by test-retest measures. Because predictive timing is an important element of attention functioning, the visual-tracking paradigm and dynamic synchronization indices described here may be useful for attention assessment.

  3. Optimal Synchronization of a Memristive Chaotic Circuit

    NASA Astrophysics Data System (ADS)

    Kountchou, Michaux; Louodop, Patrick; Bowong, Samuel; Fotsin, Hilaire; Kurths, Jurgen

    2016-06-01

    This paper deals with the problem of optimal synchronization of two identical memristive chaotic systems. We first study some basic dynamical properties and behaviors of a memristor oscillator with a simple topology. An electronic circuit (analog simulator) is proposed to investigate the dynamical behavior of the system. An optimal synchronization strategy based on the controllability functions method with a mixed cost functional is investigated. A finite horizon is explicitly computed such that the chaos synchronization is achieved at an established time. Numerical simulations are presented to verify the effectiveness of the proposed synchronization strategy. Pspice analog circuit implementation of the complete master-slave-controller systems is also presented to show the feasibility of the proposed scheme.

  4. Expression and secretion of plasma membrane Ca2+-ATPase 4a (PMCA4a) during murine estrus: association with oviductal exosomes and uptake in sperm.

    PubMed

    Al-Dossary, Amal A; Strehler, Emanuel E; Martin-Deleon, Patricia A

    2013-01-01

    PMCA4, a membrane protein, is the major Ca(2+) efflux pump in murine sperm where its deletion leads to a severe loss of hyperactivated motility and to male infertility. We have previously shown that the PMCA4b splice variant interacts with CASK (Ca(2+/)CaM-dependent serine kinase) in regulating sperm Ca(2+). More recently we detected that PMCA4a isoform, in addition to its presence in testis, is secreted in the epididymal luminal fluid and transferred to sperm. Here we show that Pmca4 mRNA is expressed in both the 4a and 4b variants in the vagina, uterus, and oviduct. Immunofluorescence reveals that PMCA4a is similarly expressed and is elevated during estrus, appearing in the glandular and luminal epithelia. Western analysis detected PMCA4a in all tissues and in the luminal fluids (LF) of the vagina (VLF), uterus (ULF), and the oviduct (OLF) collected during estrus. It was ~9- and 4-fold higher in OLF than in VLF and ULF, and only marginally present in LF collected at metestrus/diestrus. Fractionation of the LF collected at estrus, via ultracentrifugation, revealed that 100% of the PMCA4a resides in the vesicular fraction of the ULF and OLF. Transmission electron microscopy (TEM) revealed that OLF vesicles have an exosomal orientation (with the cytoplasmic-side inward), a size range of 25-100 nm, with the characteristic CD9 biomarker. Thus, we dubbed these vesicles "oviductosomes", to which PMCA4a was immunolocalized. Incubation of caudal sperm in the combined LF or exosomes resulted in up to a ~3-fold increase of sperm PMCA4a, as detected by flow cytometry, indicating in vitro uptake. Our results are consistent with the increased requirement of Ca(2+) efflux in the oviduct. They show for the first time the presence of oviductal exosomes and highlight their role, along with uterosomes and vaginal exosomes, in post-testicular sperm acquisition of PMCA4a which is essential for hyperactivated motility and fertility. PMID:24244642

  5. Flagellar Synchronization Independent of Hydrodynamic Interactions

    NASA Astrophysics Data System (ADS)

    Friedrich, Benjamin M.; Jülicher, Frank

    2012-09-01

    Inspired by the coordinated beating of the flagellar pair of the green algae Chlamydomonas, we study theoretically a simple, mirror-symmetric swimmer, which propels itself at low Reynolds number by a revolving motion of a pair of spheres. We show that perfect synchronization between these two driven spheres can occur due to the motion of the swimmer and local hydrodynamic friction forces. Hydrodynamic interactions, though crucial for net propulsion, contribute little to synchronization for this free-moving swimmer.

  6. Synchronized Flashing Lights For Approach And Docking

    NASA Technical Reports Server (NTRS)

    Book, Michael L.; Howard, Richard T.; Bryan, Thomas C.; Bell, Joseph L.

    1994-01-01

    Proposed optoelectronic system for guiding vehicle in approaching and docking with another vehicle includes active optical targets (flashing lights) on approached vehicle synchronized with sensor and image-processing circuitry on approaching vehicle. Conceived for use in automated approach and docking of two spacecraft. Also applicable on Earth to manually controlled and automated approach and docking of land vehicles, aircraft, boats, and submersible vehicles, using GPS or terrestrial broadcast time signals for synchronization. Principal advantage: optical power reduced, with consequent enhancement of safety.

  7. Experimental network synchronization via plastic optical fiber

    NASA Astrophysics Data System (ADS)

    Arellano-Delgado, A.; López-Gutiérrez, R. M.; Cruz-Hernández, C.; Posadas-Castillo, C.; Cardoza-Avendaño, L.; Serrano-Guerrero, H.

    2013-03-01

    In this paper, network synchronization of coupled Chua's circuits in star configuration is experimentally studied. In particular, plastic optical fiber (POF) is used in the network like communication channels among chaotic nodes to achieve synchronization. The master signal is sent to multiple slaves through a fiber optical coupler with corresponding electrical/optical and optical/electrical stages. An application to encrypted chaotic communication to transmit analogical signal and image messages to multiple receivers is also given.

  8. Empirical synchronized flow in oversaturated city traffic

    NASA Astrophysics Data System (ADS)

    Kerner, Boris S.; Hemmerle, Peter; Koller, Micha; Hermanns, Gerhard; Klenov, Sergey L.; Rehborn, Hubert; Schreckenberg, Michael

    2014-09-01

    Based on a study of anonymized GPS probe vehicle traces measured by personal navigation devices in vehicles randomly distributed in city traffic, empirical synchronized flow in oversaturated city traffic has been revealed. It turns out that real oversaturated city traffic resulting from speed breakdown in a city in most cases can be considered random spatiotemporal alternations between sequences of moving queues and synchronized flow patterns in which the moving queues do not occur.

  9. Automated ILA design for synchronous sequential circuits

    NASA Technical Reports Server (NTRS)

    Liu, M. N.; Liu, K. Z.; Maki, G. K.; Whitaker, S. R.

    1991-01-01

    An iterative logic array (ILA) architecture for synchronous sequential circuits is presented. This technique utilizes linear algebra to produce the design equations. The ILA realization of synchronous sequential logic can be fully automated with a computer program. A programmable design procedure is proposed to fullfill the design task and layout generation. A software algorithm in the C language has been developed and tested to generate 1 micron CMOS layouts using the Hewlett-Packard FUNGEN module generator shell.

  10. Synchronization of coupled large-scale Boolean networks

    SciTech Connect

    Li, Fangfei

    2014-03-15

    This paper investigates the complete synchronization and partial synchronization of two large-scale Boolean networks. First, the aggregation algorithm towards large-scale Boolean network is reviewed. Second, the aggregation algorithm is applied to study the complete synchronization and partial synchronization of large-scale Boolean networks. Finally, an illustrative example is presented to show the efficiency of the proposed results.

  11. An algorithm for the automatic synchronization of Omega receivers

    NASA Technical Reports Server (NTRS)

    Stonestreet, W. M.; Marzetta, T. L.

    1977-01-01

    The Omega navigation system and the requirement for receiver synchronization are discussed. A description of the synchronization algorithm is provided. The numerical simulation and its associated assumptions were examined and results of the simulation are presented. The suggested form of the synchronization algorithm and the suggested receiver design values were surveyed. A Fortran of the synchronization algorithm used in the simulation was also included.

  12. Optimal synchronization of directed complex networks

    NASA Astrophysics Data System (ADS)

    Skardal, Per Sebastian; Taylor, Dane; Sun, Jie

    2016-09-01

    We study optimal synchronization of networks of coupled phase oscillators. We extend previous theory for optimizing the synchronization properties of undirected networks to the important case of directed networks. We derive a generalized synchrony alignment function that encodes the interplay between the network structure and the oscillators' natural frequencies and serves as an objective measure for the network's degree of synchronization. Using the generalized synchrony alignment function, we show that a network's synchronization properties can be systematically optimized. This framework also allows us to study the properties of synchrony-optimized networks, and in particular, investigate the role of directed network properties such as nodal in- and out-degrees. For instance, we find that in optimally rewired networks, the heterogeneity of the in-degree distribution roughly matches the heterogeneity of the natural frequency distribution, but no such relationship emerges for out-degrees. We also observe that a network's synchronization properties are promoted by a strong correlation between the nodal in-degrees and the natural frequencies of oscillators, whereas the relationship between the nodal out-degrees and the natural frequencies has comparatively little effect. This result is supported by our theory, which indicates that synchronization is promoted by a strong alignment of the natural frequencies with the left singular vectors corresponding to the largest singular values of the Laplacian matrix.

  13. Frame Synchronization Without Attached Sync Markers

    NASA Technical Reports Server (NTRS)

    Hamkins, Jon

    2011-01-01

    We describe a method to synchronize codeword frames without making use of attached synchronization markers (ASMs). Instead, the synchronizer identifies the code structure present in the received symbols, by operating the decoder for a handful of iterations at each possible symbol offset and forming an appropriate metric. This method is computationally more complex and doesn't perform as well as frame synchronizers that utilize an ASM; nevertheless, the new synchronizer acquires frame synchronization in about two seconds when using a 600 kbps software decoder, and would take about 15 milliseconds on prototype hardware. It also eliminates the need for the ASMs, which is an attractive feature for short uplink codes whose coding gain would be diminished by the overheard of ASM bits. The lack of ASMs also would simplify clock distribution for the AR4JA low-density parity-check (LDPC) codes and adds a small amount to the coding gain as well (up to 0.2 dB).

  14. Synchronization in a semiclassical Kuramoto model.

    PubMed

    Hermoso de Mendoza, Ignacio; Pachón, Leonardo A; Gómez-Gardeñes, Jesús; Zueco, David

    2014-11-01

    Synchronization is a ubiquitous phenomenon occurring in social, biological, and technological systems when the internal rythms of their constituents are adapted to be in unison as a result of their coupling. This natural tendency towards dynamical consensus has spurred a large body of theoretical and experimental research in recent decades. The Kuramoto model constitutes the most studied and paradigmatic framework in which to study synchronization. In particular, it shows how synchronization appears as a phase transition from a dynamically disordered state at some critical value for the coupling strength between the interacting units. The critical properties of the synchronization transition of this model have been widely studied and many variants of its formulations have been considered to address different physical realizations. However, the Kuramoto model has been studied only within the domain of classical dynamics, thus neglecting its applications for the study of quantum synchronization phenomena. Based on a system-bath approach and within the Feynman path-integral formalism, we derive equations for the Kuramoto model by taking into account the first quantum fluctuations. We also analyze its critical properties, the main result being the derivation of the value for the synchronization onset. This critical coupling increases its value as quantumness increases, as a consequence of the possibility of tunneling that quantum fluctuations provide. PMID:25493855

  15. Synchronization of mobile chaotic oscillator networks

    NASA Astrophysics Data System (ADS)

    Fujiwara, Naoya; Kurths, Jürgen; Díaz-Guilera, Albert

    2016-09-01

    We study synchronization of systems in which agents holding chaotic oscillators move in a two-dimensional plane and interact with nearby ones forming a time dependent network. Due to the uncertainty in observing other agents' states, we assume that the interaction contains a certain amount of noise that turns out to be relevant for chaotic dynamics. We find that a synchronization transition takes place by changing a control parameter. But this transition depends on the relative dynamic scale of motion and interaction. When the topology change is slow, we observe an intermittent switching between laminar and burst states close to the transition due to small noise. This novel type of synchronization transition and intermittency can happen even when complete synchronization is linearly stable in the absence of noise. We show that the linear stability of the synchronized state is not a sufficient condition for its stability due to strong fluctuations of the transverse Lyapunov exponent associated with a slow network topology change. Since this effect can be observed within the linearized dynamics, we can expect such an effect in the temporal networks with noisy chaotic oscillators, irrespective of the details of the oscillator dynamics. When the topology change is fast, a linearized approximation describes well the dynamics towards synchrony. These results imply that the fluctuations of the finite-time transverse Lyapunov exponent should also be taken into account to estimate synchronization of the mobile contact networks.

  16. Quantum synchronization in an optomechanical system based on Lyapunov control

    NASA Astrophysics Data System (ADS)

    Li, Wenlin; Li, Chong; Song, Heshan

    2016-06-01

    We extend the concepts of quantum complete synchronization and phase synchronization, which were proposed in A. Mari et al., Phys. Rev. Lett. 111, 103605 (2013), 10.1103/PhysRevLett.111.103605, to more widespread quantum generalized synchronization. Generalized synchronization can be considered a necessary condition or a more flexible derivative of complete synchronization, and its criterion and synchronization measure are proposed and analyzed in this paper. As examples, we consider two typical generalized synchronizations in a designed optomechanical system. Unlike the effort to construct a special coupling synchronization system, we purposefully design extra control fields based on Lyapunov control theory. We find that the Lyapunov function can adapt to more flexible control objectives, which is more suitable for generalized synchronization control, and the control fields can be achieved simply with a time-variant voltage. Finally, the existence of quantum entanglement in different generalized synchronizations is also discussed.

  17. Nonlinear Chemical Dynamics and Synchronization

    NASA Astrophysics Data System (ADS)

    Li, Ning

    Alan Turing's work on morphogenesis, more than half a century ago, continues to motivate and inspire theoretical and experimental biologists even today. That said, there are very few experimental systems for which Turing's theory is applicable. In this thesis we present an experimental reaction-diffusion system ideally suited for testing Turing's ideas in synthetic "cells" consisting of microfluidically produced surfactant-stabilized emulsions in which droplets containing the Belousov-Zhabotinsky (BZ) oscillatory chemical reactants are dispersed in oil. The BZ reaction has become the prototype of nonlinear dynamics in chemistry and a preferred system for exploring the behavior of coupled nonlinear oscillators. Our system consists of a surfactant stabilized monodisperse emulsion of drops of aqueous BZ solution dispersed in a continuous phase of oil. In contrast to biology, here the chemistry is understood, rate constants are measured and interdrop coupling is purely diffusive. We explore a large set of parameters through control of rate constants, drop size, spacing, and spatial arrangement of the drops in lines and rings in one-dimension (1D) and hexagonal arrays in two-dimensions (2D). The Turing model is regarded as a metaphor for morphogenesis in biology but not for prediction. Here, we develop a quantitative and falsifiable reaction-diffusion model that we experimentally test with synthetic cells. We quantitatively establish the extent to which the Turing model in 1D describes both stationary pattern formation and temporal synchronization of chemical oscillators via reaction-diffusion and in 2D demonstrate that chemical morphogenesis drives physical differentiation in synthetic cells.

  18. Luteinizing hormone and progesterone concentrations and induction of estrus after use of norgestomet ear implants or constant infusion of gonadotropin-releasing hormone in anestrous, nonlactating dairy goats.

    PubMed

    Bretzlaff, K N; Nuti, L C; Scarfe, A D; Elmore, R G; Capehart, J; Varner, D D; Weston, P G

    1991-09-01

    Plasma luteinizing hormone and progesterone concentrations, time to onset of estrus, and pregnancy rates were determined in nonlactating anestrous does given 1 of 4 treatments: subcutaneous ear implants containing 3 mg of norgestomet for 9 days (NOR; n = 6); subcutaneous administration, using osmotic minipumps, of 250 ng of gonadotropin-releasing hormone (GnRH)/h for 48 hours (GnRH; n = 6); 3 mg of NOR for 9 days, followed immediately by 250 ng of GnRH/h for 48 hours (NOR + GnRH; n = 6); or no treatment (control; n = 6). During the 72-hour period after removal of NOR or insertion of GnRH pumps, 6 of 6, 0 of 6, 6 of 6, and 3 of 6 does were observed in estrus at a mean (+/- 13.8) hours in groups NOR, GnRH, NOR + GnRH, and control, respectively. Time from end of treatment to peak concentrations of luteinizing hormone were 56 +/- 4.0, 28 +/- 4.7, 34 +/- 4.3, and 41 +/- 9.7 hours (mean +/- SE) for NOR, GnRH, NOR +/- GnRH, and control, respectively. Peak concentrations of luteinizing hormone were significantly greater and occurred significantly later in does given NOR. Progesterone concentrations in does that became pregnant increased to concentrations greater than or equal to 1.0 ng/ml 3 to 5 days after breeding and remained high. Functional corpora lutea (CL) was found in 6 does that did not become pregnant, 1 CL was associated with pseudopregnancy and 1 CL was associated with ovulation prior to placement of the GnRH pumps. Functional CL failed to form in 10 of the 12 doses in groups GnRH and control.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1952326

  19. Differences in Retinal Structure and Function between Aging Male and Female Sprague-Dawley Rats are Strongly Influenced by the Estrus Cycle

    PubMed Central

    Chaychi, Samaneh; Polosa, Anna; Lachapelle, Pierre

    2015-01-01

    Purpose Biological sex and age are considered as two important factors that may influence the function and structure of the retina, an effect that might be governed by sexual hormones such as estrogen. The purpose of this study was to delineate the influence that biological sex and age exert on the retinal function and structure of rodents and also clarify the effect that the estrus cycle might exert on the retinal function of female rats. Method The retinal function of 50 normal male and female albino Sprague-Dawley (SD) rats was investigated with the electroretinogram (ERG) at postnatal day (P) 30, 60, 100, 200, and 300 (n = 5–6 male and female rats/age). Following the ERG recording sessions, retinal histology was performed in both sexes. In parallel, the retinal function of premenopausal and menopausal female rats aged P540 were also compared. Results Sex and age-related changes in retinal structure and function were observed in our animal model. However, irrespective of age, no significant difference was observed in ERG and retinal histology obtained from male and female rats. Notwithstanding the above we did however notice that between P60 and P200 there was a gradual increase in ERG amplitudes of female rats compared to males. Furthermore, the ERG of premenopausal female rats aged 18 months old (P540) was larger compared to age-matched menopausal female rats as well as that of male rats. Conclusion Our results showed that biological sex and age can influence the retinal function and structure of albino SD rats. Furthermore, we showed that cycled female rats have better retinal function compared to the menopausal female rats suggesting a beneficial effect of the estrus cycle on the retinal function. PMID:26317201

  20. Markers of criticality in phase synchronization.

    PubMed

    Botcharova, Maria; Farmer, Simon F; Berthouze, Luc

    2014-01-01

    The concept of the brain as a critical dynamical system is very attractive because systems close to criticality are thought to maximize their dynamic range of information processing and communication. To date, there have been two key experimental observations in support of this hypothesis: (i) neuronal avalanches with power law distribution of size and (ii) long-range temporal correlations (LRTCs) in the amplitude of neural oscillations. The case for how these maximize dynamic range of information processing and communication is still being made and because a significant substrate for information coding and transmission is neural synchrony it is of interest to link synchronization measures with those of criticality. We propose a framework for characterizing criticality in synchronization based on an analysis of the moment-to-moment fluctuations of phase synchrony in terms of the presence of LRTCs. This framework relies on an estimation of the rate of change of phase difference and a set of methods we have developed to detect LRTCs. We test this framework against two classical models of criticality (Ising and Kuramoto) and recently described variants of these models aimed to more closely represent human brain dynamics. From these simulations we determine the parameters at which these systems show evidence of LRTCs in phase synchronization. We demonstrate proof of principle by analysing pairs of human simultaneous EEG and EMG time series, suggesting that LRTCs of corticomuscular phase synchronization can be detected in the resting state and experimentally manipulated. The existence of LRTCs in fluctuations of phase synchronization suggests that these fluctuations are governed by non-local behavior, with all scales contributing to system behavior. This has important implications regarding the conditions under which one should expect to see LRTCs in phase synchronization. Specifically, brain resting states may exhibit LRTCs reflecting a state of readiness facilitating

  1. Markers of criticality in phase synchronization

    PubMed Central

    Botcharova, Maria; Farmer, Simon F.; Berthouze, Luc

    2014-01-01

    The concept of the brain as a critical dynamical system is very attractive because systems close to criticality are thought to maximize their dynamic range of information processing and communication. To date, there have been two key experimental observations in support of this hypothesis: (i) neuronal avalanches with power law distribution of size and (ii) long-range temporal correlations (LRTCs) in the amplitude of neural oscillations. The case for how these maximize dynamic range of information processing and communication is still being made and because a significant substrate for information coding and transmission is neural synchrony it is of interest to link synchronization measures with those of criticality. We propose a framework for characterizing criticality in synchronization based on an analysis of the moment-to-moment fluctuations of phase synchrony in terms of the presence of LRTCs. This framework relies on an estimation of the rate of change of phase difference and a set of methods we have developed to detect LRTCs. We test this framework against two classical models of criticality (Ising and Kuramoto) and recently described variants of these models aimed to more closely represent human brain dynamics. From these simulations we determine the parameters at which these systems show evidence of LRTCs in phase synchronization. We demonstrate proof of principle by analysing pairs of human simultaneous EEG and EMG time series, suggesting that LRTCs of corticomuscular phase synchronization can be detected in the resting state and experimentally manipulated. The existence of LRTCs in fluctuations of phase synchronization suggests that these fluctuations are governed by non-local behavior, with all scales contributing to system behavior. This has important implications regarding the conditions under which one should expect to see LRTCs in phase synchronization. Specifically, brain resting states may exhibit LRTCs reflecting a state of readiness facilitating

  2. Markers of criticality in phase synchronization.

    PubMed

    Botcharova, Maria; Farmer, Simon F; Berthouze, Luc

    2014-01-01

    The concept of the brain as a critical dynamical system is very attractive because systems close to criticality are thought to maximize their dynamic range of information processing and communication. To date, there have been two key experimental observations in support of this hypothesis: (i) neuronal avalanches with power law distribution of size and (ii) long-range temporal correlations (LRTCs) in the amplitude of neural oscillations. The case for how these maximize dynamic range of information processing and communication is still being made and because a significant substrate for information coding and transmission is neural synchrony it is of interest to link synchronization measures with those of criticality. We propose a framework for characterizing criticality in synchronization based on an analysis of the moment-to-moment fluctuations of phase synchrony in terms of the presence of LRTCs. This framework relies on an estimation of the rate of change of phase difference and a set of methods we have developed to detect LRTCs. We test this framework against two classical models of criticality (Ising and Kuramoto) and recently described variants of these models aimed to more closely represent human brain dynamics. From these simulations we determine the parameters at which these systems show evidence of LRTCs in phase synchronization. We demonstrate proof of principle by analysing pairs of human simultaneous EEG and EMG time series, suggesting that LRTCs of corticomuscular phase synchronization can be detected in the resting state and experimentally manipulated. The existence of LRTCs in fluctuations of phase synchronization suggests that these fluctuations are governed by non-local behavior, with all scales contributing to system behavior. This has important implications regarding the conditions under which one should expect to see LRTCs in phase synchronization. Specifically, brain resting states may exhibit LRTCs reflecting a state of readiness facilitating

  3. Synchronization controller design of two coupling permanent magnet synchronous motors system with nonlinear constraints.

    PubMed

    Deng, Zhenhua; Shang, Jing; Nian, Xiaohong

    2015-11-01

    In this paper, two coupling permanent magnet synchronous motors system with nonlinear constraints is studied. First of all, the mathematical model of the system is established according to the engineering practices, in which the dynamic model of motor and the nonlinear coupling effect between two motors are considered. In order to keep the two motors synchronization, a synchronization controller based on load observer is designed via cross-coupling idea and interval matrix. Moreover, speed, position and current signals of two motor all are taken as self-feedback signal as well as cross-feedback signal in the proposed controller, which is conducive to improving the dynamical performance and the synchronization performance of the system. The proposed control strategy is verified by simulation via Matlab/Simulink program. The simulation results show that the proposed control method has a better control performance, especially synchronization performance, than that of the conventional PI controller.

  4. Spatial synchronization using watermark key structure

    NASA Astrophysics Data System (ADS)

    Lin, Eugene T.; Delp, Edward J., III

    2004-06-01

    Recently, we proposed a method for constructing a template for efficient temporal synchronization in video watermarking. Our temporal synchronization method uses a state machine key generator for producing the watermark embedded in successive frames of video. A feature extractor allows the watermark key schedule to be content dependent, increasing the difficulty of copy and ownership attacks. It was shown that efficient synchronization can be achieved by adding temporal redundancy into the key schedule. In this paper, we explore and extend the concepts of our temporal synchronization method to spatial synchronization. The key generator is used to construct the embedded watermark of non-overlapping blocks of the video, creating a tiled structure. The autocorrelation of the tiled watermark contains local maxima or peaks with a grid-like structure, where the distance between the peaks indicates the scale of the watermark and the orientation of the peaks indicate the watermark rotation. Experimental results are obtained using digital image watermarks. Scaling and rotation attacks are investigated.

  5. Disrupted Intrinsic Local Synchronization in Poststroke Aphasia.

    PubMed

    Yang, Mi; Li, Jiao; Yao, Dezhong; Chen, Huafu

    2016-03-01

    Evidence has accumulated from the task-related and task-free (i.e., resting state) studies that alternations of intrinsic neural networks exist in poststroke aphasia (PSA) patients. However, information is lacking on the changes in the local synchronization of spontaneous functional magnetic resonance imaging blood-oxygen level-dependent fluctuations in PSA at rest. We investigated the altered intrinsic local synchronization using regional homogeneity (ReHo) on PSA (n = 17) and age- and sex-matched healthy controls (HCs) (n = 20). We examined the correlations between the abnormal ReHo values and the aphasia severity and language performance in PSA. Compared with HCs, the PSA patients exhibited decreased intrinsic local synchronization in the right lingual gyrus, the left calcarine, the left cuneus, the left superior frontal gyrus (SFG), and the left medial of SFG. The local synchronization (ReHo value) in the left medial of SFG was positively correlated with aphasia severity (r = 0.55, P = 0.027) and the naming scores of Aphasia Battery of Chinese (r = 0.66, P = 0.005). This result is consistent with the important role of this value in language processing even in the resting state. The pathogenesis of PSA may be attributed to abnormal intrinsic local synchronous in multiple brain regions. PMID:26986152

  6. Model bridging chimera state and explosive synchronization

    NASA Astrophysics Data System (ADS)

    Zhang, Xiyun; Bi, Hongjie; Guan, Shuguang; Liu, Jinming; Liu, Zonghua

    2016-07-01

    Global synchronization and partial synchronization are the two distinctive forms of synchronization in coupled oscillators and have been well studied in recent decades. Recent attention on synchronization is focused on the chimera state (CS) and explosive synchronization (ES), but little attention has been paid to their relationship. Here we study this topic by presenting a model to bridge these two phenomena, which consists of two groups of coupled oscillators, and its coupling strength is adaptively controlled by a local order parameter. We find that this model displays either CS or ES in two limits. In between the two limits, this model exhibits both CS and ES, where CS can be observed for a fixed coupling strength and ES appears when the coupling is increased adiabatically. Moreover, we show both theoretically and numerically that there are a variety of CS basin patterns for the case of identical oscillators, depending on the distributions of both the initial order parameters and the initial average phases. This model suggests a way to easily observe CS, in contrast to other models having some (weak or strong) dependence on initial conditions.

  7. Model bridging chimera state and explosive synchronization.

    PubMed

    Zhang, Xiyun; Bi, Hongjie; Guan, Shuguang; Liu, Jinming; Liu, Zonghua

    2016-07-01

    Global synchronization and partial synchronization are the two distinctive forms of synchronization in coupled oscillators and have been well studied in recent decades. Recent attention on synchronization is focused on the chimera state (CS) and explosive synchronization (ES), but little attention has been paid to their relationship. Here we study this topic by presenting a model to bridge these two phenomena, which consists of two groups of coupled oscillators, and its coupling strength is adaptively controlled by a local order parameter. We find that this model displays either CS or ES in two limits. In between the two limits, this model exhibits both CS and ES, where CS can be observed for a fixed coupling strength and ES appears when the coupling is increased adiabatically. Moreover, we show both theoretically and numerically that there are a variety of CS basin patterns for the case of identical oscillators, depending on the distributions of both the initial order parameters and the initial average phases. This model suggests a way to easily observe CS, in contrast to other models having some (weak or strong) dependence on initial conditions. PMID:27575120

  8. Disrupted Intrinsic Local Synchronization in Poststroke Aphasia

    PubMed Central

    Yang, Mi; Li, Jiao; Yao, Dezhong; Chen, Huafu

    2016-01-01

    Abstract Evidence has accumulated from the task-related and task-free (i.e., resting state) studies that alternations of intrinsic neural networks exist in poststroke aphasia (PSA) patients. However, information is lacking on the changes in the local synchronization of spontaneous functional magnetic resonance imaging blood–oxygen level-dependent fluctuations in PSA at rest. We investigated the altered intrinsic local synchronization using regional homogeneity (ReHo) on PSA (n = 17) and age- and sex-matched healthy controls (HCs) (n = 20). We examined the correlations between the abnormal ReHo values and the aphasia severity and language performance in PSA. Compared with HCs, the PSA patients exhibited decreased intrinsic local synchronization in the right lingual gyrus, the left calcarine, the left cuneus, the left superior frontal gyrus (SFG), and the left medial of SFG. The local synchronization (ReHo value) in the left medial of SFG was positively correlated with aphasia severity (r = 0.55, P = 0.027) and the naming scores of Aphasia Battery of Chinese (r = 0.66, P = 0.005). This result is consistent with the important role of this value in language processing even in the resting state. The pathogenesis of PSA may be attributed to abnormal intrinsic local synchronous in multiple brain regions. PMID:26986152

  9. Robust microcircuit synchronization by inhibitory connections

    PubMed Central

    Szücs, Attila; Huerta, Ramon; Rabinovich, Mikhail I.; Selverston, Allen I.

    2009-01-01

    SUMMARY Microcircuits in different brain areas share similar architectural and biophysical properties with compact motor network known as central pattern generators (CPGs). Consequently, CPGs have been suggested as valuable biological models for the understanding of microcircuit dynamics and particularly, their synchronization. In the present paper we use a well known compact motor network, the lobster pyloric CPG to study principles of intercircuit synchronization. We couple separate pyloric circuits obtained from two animals via artificial synapses and observe how their synchronization depends on the topology and kinetic parameters of the computer-generated synapses. Stable in-phase synchronization appears when electrically coupling the pacemaker groups of the two networks, but reciprocal inhibitory connections produce more robust and regular cooperative activity. Contralateral inhibitory connections offer effective synchronization and flexible setting of the burst phases of the interacting networks. We also show that a conductance-based mathematical model of the coupled circuits correctly reproduces the observed dynamics illustrating the generality of the phenomena. PMID:19217380

  10. Synchronization in time-varying networks.

    PubMed

    Kohar, Vivek; Ji, Peng; Choudhary, Anshul; Sinha, Sudeshna; Kurths, Jüergen

    2014-08-01

    We study the stability of the synchronized state in time-varying complex networks using the concept of basin stability, which is a nonlocal and nonlinear measure of stability that can be easily applied to high-dimensional systems [P. J. Menck, J. Heitzig, N. Marwan, and J. Kurths, Nature Phys. 9, 89 (2013)]. The time-varying character is included by stochastically rewiring each link with the average frequency f. We find that the time taken to reach synchronization is lowered and the stability range of the synchronized state increases considerably in dynamic networks. Further we uncover that small-world networks are much more sensitive to link changes than random ones, with the time-varying character of the network having a significant effect at much lower rewiring frequencies. At very high rewiring frequencies, random networks perform better than small-world networks and the synchronized state is stable over a much wider window of coupling strengths. Lastly we show that the stability range of the synchronized state may be quite different for small and large perturbations, and so the linear stability analysis and the basin stability criterion provide complementary indicators of stability. PMID:25215786

  11. Microscopic dynamics of synchronization in driven colloids

    PubMed Central

    Juniper, Michael P.N.; Straube, Arthur V.; Besseling, Rut; Aarts, Dirk G.A.L.; Dullens, Roel P.A.

    2015-01-01

    Synchronization of coupled oscillators has been scrutinized for over three centuries, from Huygens' pendulum clocks to physiological rhythms. One such synchronization phenomenon, dynamic mode locking, occurs when naturally oscillating processes are driven by an externally imposed modulation. Typically only averaged or integrated properties are accessible, leaving underlying mechanisms unseen. Here, we visualize the microscopic dynamics underlying mode locking in a colloidal model system, by using particle trajectories to produce phase portraits. Furthermore, we use this approach to examine the enhancement of mode locking in a flexible chain of magnetically coupled particles, which we ascribe to breathing modes caused by mode-locked density waves. Finally, we demonstrate that an emergent density wave in a static colloidal chain mode locks as a quasi-particle, with microscopic dynamics analogous to those seen for a single particle. Our results indicate that understanding the intricate link between emergent behaviour and microscopic dynamics is key to controlling synchronization. PMID:25994921

  12. Synchronous characterization of semiconductor microcavity laser beam

    SciTech Connect

    Wang, T. Lippi, G. L.

    2015-06-15

    We report on a high-resolution double-channel imaging method used to synchronously map the intensity- and optical-frequency-distribution of a laser beam in the plane orthogonal to the propagation direction. The synchronous measurement allows us to show that the laser frequency is an inhomogeneous distribution below threshold, but that it becomes homogeneous across the fundamental Gaussian mode above threshold. The beam’s tails deviations from the Gaussian shape, however, are accompanied by sizeable fluctuations in the laser wavelength, possibly deriving from manufacturing details and from the influence of spontaneous emission in the very low intensity wings. In addition to the synchronous spatial characterization, a temporal analysis at any given point in the beam cross section is carried out. Using this method, the beam homogeneity and spatial shape, energy density, energy center, and the defects-related spectrum can also be extracted from these high-resolution pictures.

  13. Brain activities during synchronized tapping task.

    PubMed

    Hiroyasu, Tomoyuki; Murakami, Akiho; Mao Gto; Yokouchi, Hisatake

    2015-01-01

    This study aims to investigate how people process information about other people to determine a response during human-to-human cooperative work. As a preliminary study, the mechanism of cooperative work was examined using interaction between a machine and a human. This machine was designed to have an "other person" model that simulates an emotional model of another person. The task performed in the experiment was a synchronized tapping task. Two models were prepared for this experiment, a simple model that does not employ the other person model and a synchronized model that employs the other person model. Subjects performed cooperative work with these machines. During the experiment, brain activities were measured using functional near-infrared spectroscopy. It was observed that the left inferior frontal gyrus was activated more with the synchronized model than the simple model. PMID:26737670

  14. Noise Induced Jumping Dynamics Between Synchronized Modes

    NASA Astrophysics Data System (ADS)

    Algar, Shannon D.; Stemler, Thomas; de Saedeleer, Bernard

    Synchronization is a common phenomenon whereby a dynamical system follows the pacemaker provided by an external forcing. Often, such systems have multiple synchronization modes, which are equivalent solutions. We investigate the specific case of two to one synchronization produced by the periodic forcing of a van der Pol oscillator where two possible modes, shifted by one period of the modulation, exist. By studying the flow and the local Lyapunov exponents along the orbit we give an explanation of the noise induced jumps observed in a stochastic forced oscillator. While this investigation gives results that are specific to this system, the framework presented is more general and can be applied to any system showing similar jumping dynamics.

  15. Synchronous characterization of semiconductor microcavity laser beam.

    PubMed

    Wang, T; Lippi, G L

    2015-06-01

    We report on a high-resolution double-channel imaging method used to synchronously map the intensity- and optical-frequency-distribution of a laser beam in the plane orthogonal to the propagation direction. The synchronous measurement allows us to show that the laser frequency is an inhomogeneous distribution below threshold, but that it becomes homogeneous across the fundamental Gaussian mode above threshold. The beam's tails deviations from the Gaussian shape, however, are accompanied by sizeable fluctuations in the laser wavelength, possibly deriving from manufacturing details and from the influence of spontaneous emission in the very low intensity wings. In addition to the synchronous spatial characterization, a temporal analysis at any given point in the beam cross section is carried out. Using this method, the beam homogeneity and spatial shape, energy density, energy center, and the defects-related spectrum can also be extracted from these high-resolution pictures.

  16. Phase synchronization in time-delay systems.

    PubMed

    Senthilkumar, D V; Lakshmanan, M; Kurths, J

    2006-09-01

    Though the notion of phase synchronization has been well studied in chaotic dynamical systems without delay, it has not been realized yet in chaotic time-delay systems exhibiting non-phase-coherent hyperchaotic attractors. In this paper we report identification of phase synchronization in coupled time-delay systems exhibiting hyperchaotic attractor. We show that there is a transition from nonsynchronized behavior to phase and then to generalized synchronization as a function of coupling strength. These transitions are characterized by recurrence quantification analysis, by phase differences based on a transformation of the attractors, and also by the changes in the Lyapunov exponents. We have found these transitions in coupled piecewise linear and in Mackey-Glass time-delay systems.

  17. Elastic interactions synchronize beating in cardiomyocytes.

    PubMed

    Cohen, Ohad; Safran, Samuel A

    2016-07-13

    Motivated by recent experimental results, we study theoretically the synchronization of the beating phase and frequency of two nearby cardiomyocyte cells. Each cell is represented as an oscillating force dipole in an infinite, viscoelastic medium and the propagation of the elastic signal within the medium is predicted. We examine the steady-state beating of two nearby cells, and show that elastic interactions result in forces that synchronize the phase and frequency of beating in a manner that depends on their mutual orientation. The theory predicts both in-phase and anti-phase steady-state beating depending on the relative cell orientations, as well as how synchronized beating varies with substrate elasticity and the inter-cell distance. These results suggest how mechanics plays a role in cardiac efficiency, and may be relevant for the design of cardiomyocyte based micro devices and other biomedical applications.

  18. The Scheme of Beam Synchronization in MEIC

    SciTech Connect

    Zhang, Yuhong; Derbenev, Yaroslav S.; Hutton, Andrew M.

    2013-06-01

    Synchronizing colliding beams at single or multiple collision points is a critical R&D issue in the design of a medium energy electron-ion collider (MEIC) at Jefferson Lab. The path-length variation due to changes in the ion energy, which varies over 20 to 100 GeV, could be more than several times the bunch spacing. The scheme adopted in the present MEIC baseline is centered on varying the number of bunches (i.e., harmonic number) stored in the collider ring. This could provide a set of discrete energies for proton or ions such that the beam synchronization condition is satisfied. To cover the ion energy between these synchronized values, we further propose to vary simultaneously the electron ring circumference and the frequency of the RF systems in both collider rings. We also present in this paper the requirement of frequency tunability of SRF cavities to support the scheme.

  19. Maximum entropy model for business cycle synchronization

    NASA Astrophysics Data System (ADS)

    Xi, Ning; Muneepeerakul, Rachata; Azaele, Sandro; Wang, Yougui

    2014-11-01

    The global economy is a complex dynamical system, whose cyclical fluctuations can mainly be characterized by simultaneous recessions or expansions of major economies. Thus, the researches on the synchronization phenomenon are key to understanding and controlling the dynamics of the global economy. Based on a pairwise maximum entropy model, we analyze the business cycle synchronization of the G7 economic system. We obtain a pairwise-interaction network, which exhibits certain clustering structure and accounts for 45% of the entire structure of the interactions within the G7 system. We also find that the pairwise interactions become increasingly inadequate in capturing the synchronization as the size of economic system grows. Thus, higher-order interactions must be taken into account when investigating behaviors of large economic systems.

  20. Elastic interactions synchronize beating in cardiomyocytes.

    PubMed

    Cohen, Ohad; Safran, Samuel A

    2016-07-13

    Motivated by recent experimental results, we study theoretically the synchronization of the beating phase and frequency of two nearby cardiomyocyte cells. Each cell is represented as an oscillating force dipole in an infinite, viscoelastic medium and the propagation of the elastic signal within the medium is predicted. We examine the steady-state beating of two nearby cells, and show that elastic interactions result in forces that synchronize the phase and frequency of beating in a manner that depends on their mutual orientation. The theory predicts both in-phase and anti-phase steady-state beating depending on the relative cell orientations, as well as how synchronized beating varies with substrate elasticity and the inter-cell distance. These results suggest how mechanics plays a role in cardiac efficiency, and may be relevant for the design of cardiomyocyte based micro devices and other biomedical applications. PMID:27352146

  1. Synchronization trigger control system for flow visualization

    NASA Technical Reports Server (NTRS)

    Chun, K. S.

    1987-01-01

    The use of cinematography or holographic interferometry for dynamic flow visualization in an internal combustion engine requires a control device that globally synchronizes camera and light source timing at a predefined shaft encoder angle. The device is capable of 0.35 deg resolution for rotational speeds of up to 73 240 rpm. This was achieved by implementing the shaft encoder signal addressed look-up table (LUT) and appropriate latches. The developed digital signal processing technique achieves 25 nsec of high speed triggering angle detection by using direct parallel bit comparison of the shaft encoder digital code with a simulated angle reference code, instead of using angle value comparison which involves more complicated computation steps. In order to establish synchronization to an AC reference signal whose magnitude is variant with the rotating speed, a dynamic peak followup synchronization technique has been devised. This method scrutinizes the reference signal and provides the right timing within 40 nsec. Two application examples are described.

  2. Measuring synchronization of stochastic oscillators in biology

    NASA Astrophysics Data System (ADS)

    Deng, Z.; Arsenault, S.; Mao, L.; Arnold, J.

    2016-09-01

    A fundamental problem in physics is measuring and modeling the synchronization of coupled stochastic oscillators. The problem is relatively recent in biology, where it has become possible to measure stochastic oscillators in single cells. A variety of synchronization measures have been proposed to describe a field of coupled stochastic oscillators. We introduce a synchronization measure new to this problem (but old to Genetics) called the intraclass correlation (ICC). The ICC is simple to interpret and has a statistical framework for inference. We illustrate ICC behaviour in the Kuramoto phase-locking model and on a field of over 25,000 oscillators in single cells measured every half-hour over a ten day interval.

  3. Synchronous characterization of semiconductor microcavity laser beam.

    PubMed

    Wang, T; Lippi, G L

    2015-06-01

    We report on a high-resolution double-channel imaging method used to synchronously map the intensity- and optical-frequency-distribution of a laser beam in the plane orthogonal to the propagation direction. The synchronous measurement allows us to show that the laser frequency is an inhomogeneous distribution below threshold, but that it becomes homogeneous across the fundamental Gaussian mode above threshold. The beam's tails deviations from the Gaussian shape, however, are accompanied by sizeable fluctuations in the laser wavelength, possibly deriving from manufacturing details and from the influence of spontaneous emission in the very low intensity wings. In addition to the synchronous spatial characterization, a temporal analysis at any given point in the beam cross section is carried out. Using this method, the beam homogeneity and spatial shape, energy density, energy center, and the defects-related spectrum can also be extracted from these high-resolution pictures. PMID:26133832

  4. Intra-layer synchronization in multiplex networks

    NASA Astrophysics Data System (ADS)

    Gambuzza, L. V.; Frasca, M.; Gómez-Gardeñes, J.

    2015-04-01

    We study synchronization of N oscillators indirectly coupled through a medium which is inhomogeneous and has its own dynamics. The system is formalized in terms of a multilayer network, where the top layer is made of disconnected oscillators and the bottom one, modeling the medium, consists of oscillators coupled according to a given topology. The different dynamics of the medium and the top layer is accounted for by including a frequency mismatch between them. We show a novel regime of synchronization as intra-layer coherence does not necessarily require inter-layer coherence. This regime appears under mild conditions on the bottom layer: arbitrary topologies may be considered, provided that they support synchronization of the oscillators of the medium. The existence of a density-dependent threshold as in quorum-sensing phenomena is also demonstrated.

  5. Clocking and synchronization circuits in multiprocessor systems

    SciTech Connect

    Jeong, Deog-Kyoon.

    1989-01-01

    Microprocessors based on RISC (Reduced Instruction Set Computer) concepts have demonstrated an ability to provide more computing power at a given level of integration than conventional microprocessors. The next step is multiprocessors composed of RISC processing elements. Communication bandwidth among such microprocessors is critical in achieving efficient hardware utilization. This thesis focuses on the communication capability of VLSI circuits and presents new circuit techniques as a guide to build an interconnection network of VLSI microprocessors. Two of the most prominent problems in a synchronous system, which most of the current computer systems are based on, have been clock skew and synchronization failure. A new concept called self-timed systems solves such problems but has not been accepted in microprocessor implementations yet because of its complex design procedure and increased overhead. With this in mind, this thesis concentrates on a system in which individual synchronous subsystems are connected asynchronously. Synchronous subsystems operate with a better control over clock skew using a phase locked loop (PLL) technique. Communication among subsystems is done asynchronously with a controlled synchronization failure rate. One advantage is that conventional VLSI design methodologies which are more efficient can still be applied. Circuit techniques for PLL-based clock generation are described along with stability criteria. The main objective of the circuit is to realize a zero delay buffer. Experimental results show the feasibility of such circuits in VLSI. Synchronizer circuit configurations in both bipolar and MOS technology that best utilize each device, or overcome the technology limit using a bandwidth doubling technique are shown. Interface techniques including handshake mechanisms in such a system are also described.

  6. Measures of quantum synchronization in continuous variable systems.

    PubMed

    Mari, A; Farace, A; Didier, N; Giovannetti, V; Fazio, R

    2013-09-01

    We introduce and characterize two different measures which quantify the level of synchronization of coupled continuous variable quantum systems. The two measures allow us to extend to the quantum domain the notions of complete and phase synchronization. The Heisenberg principle sets a universal bound to complete synchronization. The measure of phase synchronization is, in principle, unbounded; however, in the absence of quantum resources (e.g., squeezing) the synchronization level is bounded below a certain threshold. We elucidate some interesting connections between entanglement and synchronization and, finally, discuss an application based on quantum optomechanical systems. PMID:25166668

  7. Decoding and synchronization of error correcting codes

    NASA Astrophysics Data System (ADS)

    Madkour, S. A.

    1983-01-01

    Decoding devices for hard quantization and soft decision error correcting codes are discussed. A Meggit decoder for Reed-Solomon polynominal codes was implemented and tested. It uses 49 TTL logic IC. A maximum binary frequency of 30 Mbit/sec is demonstrated. A soft decision decoding approach was applied to hard decision decoding, using the principles of threshold decoding. Simulation results indicate that the proposed schema achieves satisfactory performance using only a small number of parity checks. The combined correction of substitution and synchronization errors is analyzed. The algorithm presented shows the capability of convolutional codes to correct synchronization errors as well as independent additive errors without any additional redundancy.

  8. Carrier and symbol synchronization system performance study

    NASA Technical Reports Server (NTRS)

    Lindsey, W. C.

    1976-01-01

    Results pertinent to predicting the performance of convolutionally encoded binary phase-shift keyed communication links were presented. The details of the development are provided in four sections. These sections are concerned with developing the bit error probability performance degradations due to PN despreading by a time-shared delay locked loop, the Costas demodulation process, symbol synchronization effects and cycle slipping phenomena in the Costas loop. In addition, Costas cycle slipping probabilities are studied as functions of Doppler count time and signal-to-noise conditions. The effect of cycle slipping in the symbol synchronizer is also studied as a function of channel Doppler and other frequency uncertainties.

  9. Stochastic synchronization of neural activity waves.

    PubMed

    Kilpatrick, Zachary P

    2015-04-01

    We demonstrate that waves in distinct layers of a neuronal network can become phase locked by common spatiotemporal noise. This phenomenon is studied for stationary bumps, traveling waves, and breathers. A weak noise expansion is used to derive an effective equation for the position of the wave in each layer, yielding a stochastic differential equation with multiplicative noise. Stability of the synchronous state is characterized by a Lyapunov exponent, which we can compute analytically from the reduced system. Our results extend previous work on limit-cycle oscillators, showing common noise can synchronize waves in a broad class of models.

  10. Carrying Synchronous Voice Data On Asynchronous Networks

    NASA Technical Reports Server (NTRS)

    Bergman, Larry A.

    1990-01-01

    Buffers restore synchronism for internal use and permit asynchronism in external transmission. Proposed asynchronous local-area digital communication network (LAN) carries synchronous voice, data, or video signals, or non-real-time asynchronous data signals. Network uses double buffering scheme that reestablishes phase and frequency references at each node in network. Concept demonstrated in token-ring network operating at 80 Mb/s, pending development of equipment operating at planned data rate of 200 Mb/s. Technique generic and used with any LAN as long as protocol offers deterministic (or bonded) access delays and sufficient capacity.

  11. Onset of synchronization in complex gradient networks.

    PubMed

    Wang, Xingang; Huang, Liang; Guan, Shuguang; Lai, Ying-Cheng; Lai, Choy Heng

    2008-09-01

    Recently, it has been found that the synchronizability of a scale-free network can be enhanced by introducing some proper gradient in the coupling. This result has been obtained by using eigenvalue-spectrum analysis under the assumption of identical node dynamics. Here we obtain an analytic formula for the onset of synchronization by incorporating the Kuramoto model on gradient scale-free networks. Our result provides quantitative support for the enhancement of synchronization in such networks, further justifying their ubiquity in natural and in technological systems. PMID:19045491

  12. Synchronous generator wind energy conversion control system

    SciTech Connect

    Medeiros, A.L.R.; Lima, A.M.N.; Jacobina, C.B.; Simoes, F.J.

    1996-12-31

    This paper presents the performance evaluation and the design of the control system of a WECS (Wind Energy Conversion System) that employs a synchronous generator based on its digital simulation. The WECS discussed in this paper is connected to the utility grid through two Pulse Width Modulated (PWM) power converters. The structure of the proposed WECS enables us to achieve high performance energy conversion by: (i) maximizing the wind energy capture and (ii) minimizing the reactive power flowing between the grid and the synchronous generator. 8 refs., 19 figs.

  13. Cycle slipping in phase synchronization systems

    NASA Astrophysics Data System (ADS)

    Yang, Ying; Huang, Lin

    2007-02-01

    Cycle slipping is a characteristically nonlinear phenomenon in phase synchronization systems, which is highly dependent of the initial state of the system. Slipping a cycle means that the phase error is increased to such an extent that the generator to be synchronized slips one complete cycle with respect to the input phase. In this Letter, a linear matrix inequality (LMI) based approach is proposed and the estimation of the number of cycles which slips a solution of the system is obtained by solving a quasi-convex optimization problem of LMI. Applications to phase locked loops demonstrate the validity of the proposed approach.

  14. A relativistic analysis of clock synchronization

    NASA Technical Reports Server (NTRS)

    Thomas, J. B.

    1974-01-01

    The relativistic conversion between coordinate time and atomic time is reformulated to allow simpler time calculations relating analysis in solar-system barycentric coordinates (using coordinate time) with earth-fixed observations (measuring earth-bound proper time or atomic time.) After an interpretation of terms, this simplified formulation, which has a rate accuracy of about 10 to the minus 15th power, is used to explain the conventions required in the synchronization of a world wide clock network and to analyze two synchronization techniques-portable clocks and radio interferometry. Finally, pertinent experiment tests of relativity are briefly discussed in terms of the reformulated time conversion.

  15. Synchronization of Asynchronous Switched Boolean Network.

    PubMed

    Zhang, Hao; Wang, Xingyuan; Lin, Xiaohui

    2015-01-01

    In this paper, the complete synchronizations for asynchronous switched Boolean network with free Boolean sequence controllers and close-loop controllers are studied. First, the basic asynchronous switched Boolean network model is provided. With the method of semi-tensor product, the Boolean dynamics is translated into linear representation. Second, necessary and sufficient conditions for ASBN synchronization with free Boolean sequence control and close-loop control are derived, respectively. Third, some illustrative examples are provided to show the efficiency of the proposed methods.

  16. Clock synchronization by the Symphonie and Laser Synchronization from Stationary Orbit (LASSO) geostationary satellites

    NASA Astrophysics Data System (ADS)

    Brunet, M.

    The use of atomic clocks is described, and the use of satellites to assure their intercontinental synchronization is discussed. The Symphonie satellites assure a transatlantic (France-Canada) synchronization in the 4 to 6 GHz band with nanosec accuracy. Atmospheric and relativistic effects are corrected to within 5 nsec, but instrument delay calibration remains a problem. The Laser Synchronization from Stationary Orbit (LASSO) experiment is based on the measurement of the time it takes a laser pulse to complete the return journey from a ground station to the satellite. The LASSO was designed for the SIRIO-2 satellite, whose launch failed, and is now proposed for Meteosat-2.

  17. Compatibility of Motion Facilitates Visuomotor Synchronization

    ERIC Educational Resources Information Center

    Hove, Michael J.; Spivey, Michael J.; Krumhansl, Carol L.

    2010-01-01

    Prior research indicates that synchronized tapping performance is very poor with flashing visual stimuli compared with auditory stimuli. Three finger-tapping experiments compared flashing visual metronomes with visual metronomes containing a spatial component, either compatible, incompatible, or orthogonal to the tapping action. In Experiment 1,…

  18. Synchronicity and the meaning-making psyche.

    PubMed

    Colman, Warren

    2011-09-01

    This paper contrasts Jung's account of synchronicity as evidence of an objective principle of meaning in Nature with a view that emphasizes human meaning-making. All synchronicities generate indicative signs but only where this becomes a 'living symbol' of a transcendent intentionality at work in a living universe does synchronicity generate the kind of symbolic meaning that led Jung to posit the existence of a Universal Mind. This is regarded as a form of personal, experiential knowledge belonging to the 'imaginal world of meaning' characteristic of the 'primordial mind', as opposed to the 'rational world of knowledge' in which Jung attempted to present his experiences as if they were empirically and publicly verifiable. Whereas rational knowledge depends on a form of meaning in which causal chains and logical links are paramount, imaginal meaning is generated by forms of congruent correspondence-a feature that synchronicity shares with metaphor and symbol-and the creation of narratives by means of retroactive organization of its constituent elements. PMID:21884094

  19. Synchronous transfer circuits for redundant systems

    NASA Technical Reports Server (NTRS)

    Nagano, S.

    1978-01-01

    Circuit arrangements for flip-flops, counters, and clock drivers in redundant systems ensure that control is synchronously transferred to surviving components when failure occurs. In addition to original application to spacecraft systems, redundant circuits have terrestrial uses in power generators, solar-energy converters, computers, vehicle controllers, and other systems demanding high reliability.

  20. Circuit increases capability of hysteresis synchronous motor

    NASA Technical Reports Server (NTRS)

    Markowitz, I. N.

    1967-01-01

    Frequency and phase detector circuit enables a hysteresis synchronous motor to drive a load of given torque value at a precise speed determined by a stable reference. This technique permits driving larger torque loads with smaller motors and lower power drain.

  1. Digital phase shifter synchronizes local oscillators

    NASA Technical Reports Server (NTRS)

    Ali, S. M.

    1978-01-01

    Digital phase-shifting network is used as synchronous frequency multiplier for applications such as phase-locking two signals that may differ in frequency. Circuit has various phase-shift capability. Possible applications include data-communication systems and hybrid digital/analog phase-locked loops.

  2. Synchronized flow in oversaturated city traffic

    NASA Astrophysics Data System (ADS)

    Kerner, Boris S.; Klenov, Sergey L.; Hermanns, Gerhard; Hemmerle, Peter; Rehborn, Hubert; Schreckenberg, Michael

    2013-11-01

    Based on numerical simulations with a stochastic three-phase traffic flow model, we reveal that moving queues (moving jams) in oversaturated city traffic dissolve at some distance upstream of the traffic signal while transforming into synchronized flow. It is found that, as in highway traffic [Kerner, Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.85.036110 85, 036110 (2012)], such a jam-absorption effect in city traffic is explained by a strong driver's speed adaptation: Time headways (space gaps) between vehicles increase upstream of a moving queue (moving jam), resulting in moving queue dissolution. It turns out that at given traffic signal parameters, the stronger the speed adaptation effect, the shorter the mean distance between the signal location and the road location at which moving queues dissolve fully and oversaturated traffic consists of synchronized flow only. A comparison of the synchronized flow in city traffic found in this Brief Report with synchronized flow in highway traffic is made.

  3. Student Perceptions of Online Synchronous Courses.

    ERIC Educational Resources Information Center

    Cereijo, Maria Victora Perez; Tyler-Wood, Tandra; Young, Jon

    This study identified student reasons for participating in synchronous Web-based learning environments. Students were interviewed after completing a series of surveys designed to elicit their perceptions of the strengths and weaknesses of the delivery methodology. Responses indicated that both convenience and learning enhancement were considered…

  4. An Online Synchronous Test for Professional Interpreters

    ERIC Educational Resources Information Center

    Chen, Nian-Shing; Ko, Leong

    2010-01-01

    This article is based on an experiment designed to conduct an interpreting test for multiple candidates online, using web-based synchronous cyber classrooms. The test model was based on the accreditation test for Professional Interpreters produced by the National Accreditation Authority of Translators and Interpreters (NAATI) in Australia.…

  5. Clock Synchronization for Multihop Wireless Sensor Networks

    ERIC Educational Resources Information Center

    Solis Robles, Roberto

    2009-01-01

    In wireless sensor networks, more so generally than in other types of distributed systems, clock synchronization is crucial since by having this service available, several applications such as media access protocols, object tracking, or data fusion, would improve their performance. In this dissertation, we propose a set of algorithms to achieve…

  6. Synchronous Computer-Mediated Communication and Interaction

    ERIC Educational Resources Information Center

    Ziegler, Nicole

    2016-01-01

    The current study reports on a meta-analysis of the relative effectiveness of interaction in synchronous computer-mediated communication (SCMC) and face-to-face (FTF) contexts. The primary studies included in the analysis were journal articles and dissertations completed between 1990 and 2012 (k = 14). Results demonstrate that interaction in SCMC…

  7. Synchronicity and the meaning-making psyche.

    PubMed

    Colman, Warren

    2011-09-01

    This paper contrasts Jung's account of synchronicity as evidence of an objective principle of meaning in Nature with a view that emphasizes human meaning-making. All synchronicities generate indicative signs but only where this becomes a 'living symbol' of a transcendent intentionality at work in a living universe does synchronicity generate the kind of symbolic meaning that led Jung to posit the existence of a Universal Mind. This is regarded as a form of personal, experiential knowledge belonging to the 'imaginal world of meaning' characteristic of the 'primordial mind', as opposed to the 'rational world of knowledge' in which Jung attempted to present his experiences as if they were empirically and publicly verifiable. Whereas rational knowledge depends on a form of meaning in which causal chains and logical links are paramount, imaginal meaning is generated by forms of congruent correspondence-a feature that synchronicity shares with metaphor and symbol-and the creation of narratives by means of retroactive organization of its constituent elements.

  8. Synchronization in Disordered Josephson Junction Arrays

    NASA Astrophysics Data System (ADS)

    Trees, B. R.; Dissanayake, S. T. M.

    2002-03-01

    We have studied the dynamics of a ladder array of overdamped Josephson junctions with periodic boundary conditions. The junctions have critical current and resistive disorder, are current biased above the critical current, and their voltages oscillate with nonidentical bare frequencies. We have been interested in the onset of synchronization in the rung junctions of the ladder, in which nearest neighbor interactions of strength α renormalize the bare frequencies to a common value. The degree of synchronization of the array is measured by an order parameter, r (0<= r<= 1), as a function of α and the spread of bare frequencies. For a given frequency spread, a synchronization phase transition is clearly visible with an increase in α. We have also determined that a time-averaged version of the resistively-shunted junction equations can be used as an accurate description of the dynamics of the junctions. The solutions to the averaged equations exhibit phase slips between pairs of junctions for certain ranges of values of α and also demonstrate that the relationship between the array size, N, and the critical coupling strength for the onset of synchronization scales as N^2. This research was partially funded by a grant to Ohio Wesleyan University from the McGregor Foundation to support student research.

  9. Angular Synchronization by Eigenvectors and Semidefinite Programming

    PubMed Central

    Singer, A.

    2010-01-01

    The angular synchronization problem is to obtain an accurate estimation (up to a constant additive phase) for a set of unknown angles θ1, …, θn from m noisy measurements of their offsets θi − θj mod 2π. Of particular interest is angle recovery in the presence of many outlier measurements that are uniformly distributed in [0, 2π) and carry no information on the true offsets. We introduce an efficient recovery algorithm for the unknown angles from the top eigenvector of a specially designed Hermitian matrix. The eigenvector method is extremely stable and succeeds even when the number of outliers is exceedingly large. For example, we successfully estimate n = 400 angles from a full set of m=(4002) offset measurements of which 90% are outliers in less than a second on a commercial laptop. The performance of the method is analyzed using random matrix theory and information theory. We discuss the relation of the synchronization problem to the combinatorial optimization problem Max-2-Lin mod L and present a semidefinite relaxation for angle recovery, drawing similarities with the Goemans-Williamson algorithm for finding the maximum cut in a weighted graph. We present extensions of the eigenvector method to other synchronization problems that involve different group structures and their applications, such as the time synchronization problem in distributed networks and the surface reconstruction problems in computer vision and optics. PMID:21179593

  10. Synchronous bilateral breast cancer in a male

    PubMed Central

    Rubio Hernández, María Caridad; Díaz Prado, Yenia Ivet; Pérez, Suanly Rodríguez; Díaz, Ronald Rodríguez; Aleaga, Zaili Gutiérrez

    2013-01-01

    Male breast cancer, which represents only 1% of all breast cancers, is occasionally associated with a family history of breast cancer. Sporadic male breast cancers presenting with another primary breast cancer are extremely rare. In this article, we report on a 70-year-old male patient with bilateral multifocal and synchronous breast cancer and without a family history of breast cancer. PMID:24319497

  11. Blending Online Asynchronous and Synchronous Learning

    ERIC Educational Resources Information Center

    Yamagata-Lynch, Lisa C.

    2014-01-01

    In this article I will share a qualitative self-study about a 15-week blended 100% online graduate level course facilitated through synchronous meetings on Blackboard Collaborate and asynchronous discussions on Blackboard. I taught the course at the University of Tennessee (UT) during the spring 2012 semester and the course topic was online…

  12. VLBI clock synchronization. [for atomic clock rate

    NASA Technical Reports Server (NTRS)

    Counselman, C. C., III; Shapiro, I. I.; Rogers, A. E. E.; Hinteregger, H. F.; Knight, C. A.; Whitney, A. R.; Clark, T. A.

    1977-01-01

    The potential accuracy of VLBI (very long baseline interferometry) for clock epoch and rate comparisons was demonstrated by results from long- and short-baseline experiments. It was found that atomic clocks at widely separated sites (several thousand kilometers apart) can be synchronized to within several nanoseconds from a few minutes of VLBI observations and to within one nanosecond from several hours of observations.

  13. Behavior Matching in Multimodal Communication Is Synchronized

    ERIC Educational Resources Information Center

    Louwerse, Max M.; Dale, Rick; Bard, Ellen G.; Jeuniaux, Patrick

    2012-01-01

    A variety of theoretical frameworks predict the resemblance of behaviors between two people engaged in communication, in the form of coordination, mimicry, or alignment. However, little is known about the time course of the behavior matching, even though there is evidence that dyads synchronize oscillatory motions (e.g., postural sway). This study…

  14. Complete chaotic synchronization in mutually coupled time-delay systems.

    PubMed

    Landsman, Alexandra S; Schwartz, Ira B

    2007-02-01

    Complete chaotic synchronization of end lasers has been observed in a line of mutually coupled, time-delayed system of three lasers, with no direct communication between the end lasers. The present paper uses ideas from generalized synchronization to explain the complete synchronization in the presence of long coupling delays, applied to a model of mutually coupled semiconductor lasers in a line. These ideas significantly simplify the analysis by casting the stability in terms of the local dynamics of each laser. The variational equations near the synchronization manifold are analyzed, and used to derive the synchronization condition that is a function of parameters. The results explain and predict the dependence of synchronization on various parameters, such as time delays, strength of coupling and dissipation. The ideas can be applied to understand complete synchronization in other chaotic systems with coupling delays and no direct communication between synchronized subsystems.

  15. A Simple Circuit for Demonstrating Regular and Synchronized Chaos.

    ERIC Educational Resources Information Center

    Carroll, Thomas L.

    1995-01-01

    Discusses the physics behind the synchronization of chaos. Describes an easy to build an electronic circuit which can be used to demonstrate chaos and the synchronization of chaos. Contains 19 references. (JRH)

  16. Generalized synchronization in mutually coupled oscillators and complex networks.

    PubMed

    Moskalenko, Olga I; Koronovskii, Alexey A; Hramov, Alexander E; Boccaletti, Stefano

    2012-09-01

    We introduce a concept of generalized synchronization, able to encompass the setting of collective synchronized behavior for mutually coupled systems and networking systems featuring complex topologies in their connections. The onset of the synchronous regime is confirmed by the dependence of the system's Lyapunov exponents on the coupling parameter. The presence of a generalized synchronization regime is verified by means of the nearest neighbor method.

  17. Transmission of chimeric HIV by mating in conventional mice: prevention by pre-exposure antiretroviral therapy and reduced susceptibility during estrus.

    PubMed

    Hadas, Eran; Chao, Wei; He, Hongxia; Saini, Manisha; Daley, Eleen; Saifuddin, Mohammed; Bentsman, Galina; Ganz, Eric; Volsky, David J; Potash, Mary Jane

    2013-09-01

    Heterosexual transmission accounts for the majority of new human immunodeficiency virus (HIV) cases worldwide. The current approach to investigate HIV heterosexual transmission in animals involves application of virus stock to the vaginal surface, a method that does not reproduce the physiological conditions of vaginal intercourse that influence the rate of transmission. We have previously described efficient infection of conventional mice using EcoHIV/NL4-3 and EcoHIV/NDK, chimeric HIV molecular clones constructed to express all HIV structural and regulatory genes except envelope, which is replaced by a rodent-tropic envelope gene. Here we investigated whether EcoHIV/NDK-infected male mice transmit virus to females during coitus, and the sensitivity of this transmission to HIV pre-exposure prophylaxis and the estrus state. Our general approach was to allow mating between EcoHIV/NDK-infected male mice and uninfected females for 1-7 nights. At 1-6 weeks after mating, mice were euthanized and virus burdens were measured by quantitative PCR (qPCR) amplification of HIV RNA or DNA in peritoneal macrophages, inguinal lymph node cells, spleen cells or vas deferens, or by ELISA for antibodies to HIV Gag. We found that 70-100% of female mice mated to EcoHIV/NDK-infected males acquired infection. Pericoital treatment of females with either 2',3'-dideoxcytidine (ddC) or tenofovir largely prevented their EcoHIV/NDK infection by mating (P<0.05 and P<0.003, respectively). In males, T cells were dispensable for virus transmission. The rate of EcoHIV/NDK sexual transmission to females in estrus declined sharply (P=0.003) but their infection by injection was unaffected, indicating that the local environment in the female reproductive tract influences susceptibility to HIV. We conclude that this system of EcoHIV/NDK transmission during mouse mating reproduces key features of heterosexual transmission of HIV in humans and can be used to investigate its biology and control.

  18. Broadband Criticality of Human Brain Network Synchronization

    PubMed Central

    Kitzbichler, Manfred G.; Smith, Marie L.; Christensen, Søren R.; Bullmore, Ed

    2009-01-01

    Self-organized criticality is an attractive model for human brain dynamics, but there has been little direct evidence for its existence in large-scale systems measured by neuroimaging. In general, critical systems are associated with fractal or power law scaling, long-range correlations in space and time, and rapid reconfiguration in response to external inputs. Here, we consider two measures of phase synchronization: the phase-lock interval, or duration of coupling between a pair of (neurophysiological) processes, and the lability of global synchronization of a (brain functional) network. Using computational simulations of two mechanistically distinct systems displaying complex dynamics, the Ising model and the Kuramoto model, we show that both synchronization metrics have power law probability distributions specifically when these systems are in a critical state. We then demonstrate power law scaling of both pairwise and global synchronization metrics in functional MRI and magnetoencephalographic data recorded from normal volunteers under resting conditions. These results strongly suggest that human brain functional systems exist in an endogenous state of dynamical criticality, characterized by a greater than random probability of both prolonged periods of phase-locking and occurrence of large rapid changes in the state of global synchronization, analogous to the neuronal “avalanches” previously described in cellular systems. Moreover, evidence for critical dynamics was identified consistently in neurophysiological systems operating at frequency intervals ranging from 0.05–0.11 to 62.5–125 Hz, confirming that criticality is a property of human brain functional network organization at all frequency intervals in the brain's physiological bandwidth. PMID:19300473

  19. Synchronous Control Method and Realization of Automated Pharmacy Elevator

    NASA Astrophysics Data System (ADS)

    Liu, Xiang-Quan

    Firstly, the control method of elevator's synchronous motion is provided, the synchronous control structure of double servo motor based on PMAC is accomplished. Secondly, synchronous control program of elevator is implemented by using PMAC linear interpolation motion model and position error compensation method. Finally, the PID parameters of servo motor were adjusted. The experiment proves the control method has high stability and reliability.

  20. 21 CFR 892.1970 - Radiographic ECG/respirator synchronizer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic ECG/respirator synchronizer. 892.1970... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1970 Radiographic ECG/respirator synchronizer. (a) Identification. A radiographic ECG/respirator synchronizer is a device intended to be used...

  1. 21 CFR 892.1410 - Nuclear electrocardiograph synchronizer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nuclear electrocardiograph synchronizer. 892.1410... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1410 Nuclear electrocardiograph synchronizer. (a) Identification. A nuclear electrocardiograph synchronizer is a device intended for use...

  2. 21 CFR 892.1410 - Nuclear electrocardiograph synchronizer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nuclear electrocardiograph synchronizer. 892.1410... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1410 Nuclear electrocardiograph synchronizer. (a) Identification. A nuclear electrocardiograph synchronizer is a device intended for use...

  3. 21 CFR 892.1410 - Nuclear electrocardiograph synchronizer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nuclear electrocardiograph synchronizer. 892.1410... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1410 Nuclear electrocardiograph synchronizer. (a) Identification. A nuclear electrocardiograph synchronizer is a device intended for use...

  4. 21 CFR 892.1410 - Nuclear electrocardiograph synchronizer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nuclear electrocardiograph synchronizer. 892.1410... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1410 Nuclear electrocardiograph synchronizer. (a) Identification. A nuclear electrocardiograph synchronizer is a device intended for use...

  5. 21 CFR 892.1410 - Nuclear electrocardiograph synchronizer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nuclear electrocardiograph synchronizer. 892.1410... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1410 Nuclear electrocardiograph synchronizer. (a) Identification. A nuclear electrocardiograph synchronizer is a device intended for use...

  6. New diagnostic potentialities of cardiorespiratory synchronization in children.

    PubMed

    Potyagailo, E G; Pokrovskii, V M

    2003-11-01

    The study demonstrated that the method of cardiorespiratory synchronization provides valuable information on the nature of arrhythmia and helps to evaluate the regulatory adaptive potentialities of a child. The width of synchronization range and the latency of synchronization at the lower boundary are the indicators of regulatory adaptive potentialities. PMID:14968176

  7. 21 CFR 892.1970 - Radiographic ECG/respirator synchronizer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiographic ECG/respirator synchronizer. 892.1970... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1970 Radiographic ECG/respirator synchronizer. (a) Identification. A radiographic ECG/respirator synchronizer is a device intended to be used...

  8. Feedback Controller Design for the Synchronization of Boolean Control Networks.

    PubMed

    Liu, Yang; Sun, Liangjie; Lu, Jianquan; Liang, Jinling

    2016-09-01

    This brief investigates the partial and complete synchronization of two Boolean control networks (BCNs). Necessary and sufficient conditions for partial and complete synchronization are established by the algebraic representations of logical dynamics. An algorithm is obtained to construct the feedback controller that guarantees the synchronization of master and slave BCNs. Two biological examples are provided to illustrate the effectiveness of the obtained results.

  9. The linear synchronization measures of uterine EMG signals: Evidence of synchronized action potentials during propagation.

    PubMed

    Domino, Malgorzata; Pawlinski, Bartosz; Gajewski, Zdzislaw

    2016-11-01

    Evaluation of synchronization between myoelectric signals can give new insights into the functioning of the complex system of porcine myometrium. We propose a model of uterine contractions according to the hypothesis of action potentials similarity which is possible to detect during propagation in the uterine wall. We introduce similarity measures based on the concept of synchronization as used in matching linear signals such as electromyographic (EMG) time series data. The aim was to present linear measures to assess synchronization between contractions in different topographic regions of the uterus. We use the cross-correlation function (ƒx,y[l], ƒy,z[l]) and the cross-coherence function (Cxy[ƒ], Cyz[ƒ]) to assess synchronization between three data series of a diestral uterine EMG bundles in porcine reproductive tract. Spontaneous uterine activity was recorded using telemetry method directly by three-channel transmitter and three silver bipolar needle electrodes sutured on different topographic regions of the reproductive tract in the sow. The results show the usefulness of the cross-coherence function in that synchronization between uterine horn and corpus uteri for multiple action potentials (bundles) could be observed. The EMG bundles synchronization may be used to investigate the direction and velocity of EMG signals propagation in porcine reproductive tract. PMID:27570104

  10. Clinical Inquiry: Which nonhormonal treatments are effective for hot flashes?

    PubMed

    Kelsberg, Gary; Maragh, Leticia; Safranek, Sarah

    2016-05-01

    Selective serotonin reuptake inhibitors (SSRIs [fluoxetine, sertraline, paroxetine]) and the selective norepinephrine reuptake inhibitor (SNRI) venlafaxine, as well as clonidine and gabapentin, reduce hot flashes by about 25% (approximately one per day) in women with and without a history of breast cancer. No studies compare medications against each other to determine a single best option. PMID:27275942

  11. Delivering non-hormonal contraceptives to men: advances and obstacles

    PubMed Central

    Mruk, Dolores D.; Cheng, C. Yan

    2014-01-01

    There have been major advances in male contraceptive research during the past two decades. However, for a contraceptive to be used by men, its safety requires more stringent scrutiny than therapeutic compounds for treatment of illnesses because the contraceptives will be used by healthy individuals for an extended period of time, perhaps decades. A wide margin is therefore required between the effective dose range and doses that cause toxicity. It might be preferable that a male contraceptive, in particular a non-hormone-based compound, is delivered specifically and/or directly to the testis and has a rapid metabolic clearance rate, reducing the length of exposure in the liver and kidney. In this article, we highlight the latest developments regarding contraceptive delivery to men and with the aim of providing useful information for investigators in future studies. PMID:18191256

  12. Genes in the GABA Pathway Increase in the Lateral Thalamus of Sprague-Dawley Rats During the Proestrus/Estrus Phase.

    PubMed

    Umorin, Mikhail; Stinson, Crystal; Bellinger, Larry L; Kramer, Phillip R

    2016-05-01

    Pain can vary over the estrous cycle as a result of changes in estradiol concentration but the mechanism causing this variation is unclear. Because the thalamus is important in pain control, gene expression in the lateral thalamus (ventral posteromedial, ventral posterolateral, reticular thalamic nuclei) was screened at different phases of the estrous cycle. Gene expression changes in Sprague-Dawley rats were further analyzed by real-time PCR and ELISA and plasma estradiol levels were measured by RIAs at different phases of the estrous cycle. Our results indicated that both the RNA and protein expression of glutamate decarboxylase 1 and 2 (GAD1, GAD2), GABA(A) receptor-associated protein like 1 (GABARAPL1), and vesicular GABA transporter (VGAT) significantly increased in the lateral thalamus when plasma estradiol levels were elevated. Estradiol levels were elevated during the proestrus and estrus phases of the estrous cycle. Estrogen receptor α (ERα) was observed to be co-localized in thalamic cells and thalamic infusion of an ERα antagonist significantly reduced GAD1 and VGAT transcript. GAD1, GAD2, GABARAPL1, and VGAT have been shown to effect neuronal responses suggesting that attenuation of pain during the estrous cycle can be dependent, in part, through estradiol induced changes in thalamic gene expression. PMID:26388520

  13. Prenatal exposure to the phytoestrogen daidzein resulted in persistent changes in ovarian surface epithelial cell height, folliculogenesis, and estrus phase length in adult Sprague-Dawley rat offspring.

    PubMed

    Talsness, Chris; Grote, Konstanze; Kuriyama, Sergio; Presibella, Kenia; Sterner-Kock, Anja; Poça, Katia; Chahoud, Ibrahim

    2015-01-01

    Daidzein (DZ), an isoflavone with the potential to interfere with estrogen signaling, is found in soy products, which have gained popularity due to purported beneficial effects on the cardiovascular and skeletal systems and potential antineoplastic properties. However, the ingestion of phytoestrogens has been associated with impaired reproductive function in many species. The aim of this study was to determine the long-term effects on the ovaries of rat offspring exposed to DZ or ethinyl estradiol (EE) during prenatal development. Gravid rats were administered either vehicle or 5 or 60 mg DZ/kg body weight/d or 0.002 mg 17-α EE /kg body weight/d on gestational days 6-21. Ovarian-related endpoints were investigated during adulthood in female offspring. The mean cell height of the ovarian surface epithelium was significantly reduced in all treated groups. Alterations in folliculogenesis included increased follicular atresia, a reduction in secondary and tertiary follicle numbers, and cyst formation. An elevated prevalence of a slightly prolonged estrus phase was also observed. The morphological changes to the ovarian surface epithelium are consistent with an antiproliferative effect, while ovarian folliculogenesis was adversely affected. The effects of the high dose DZ were similar to those observed with 17-α EE. PMID:26039681

  14. Illumination-based synchronization of high-speed vision sensors.

    PubMed

    Hou, Lei; Kagami, Shingo; Hashimoto, Koichi

    2010-01-01

    To acquire images of dynamic scenes from multiple points of view simultaneously, the acquisition time of vision sensors should be synchronized. This paper describes an illumination-based synchronization method derived from the phase-locked loop (PLL) algorithm. Incident light to a vision sensor from an intensity-modulated illumination source serves as the reference signal for synchronization. Analog and digital computation within the vision sensor forms a PLL to regulate the output signal, which corresponds to the vision frame timing, to be synchronized with the reference. Simulated and experimental results show that a 1,000 Hz frame rate vision sensor was successfully synchronized with 32 μs jitters.

  15. Studying synchronization to a musical beat in nonhuman animals.

    PubMed

    Patel, Aniruddh D; Iversen, John R; Bregman, Micah R; Schulz, Irena

    2009-07-01

    The recent discovery of spontaneous synchronization to music in a nonhuman animal (the sulphur-crested cockatoo Cacatua galerita eleonora) raises several questions. How does this behavior differ from nonmusical synchronization abilities in other species, such as synchronized frog calls or firefly flashes? What significance does the behavior have for debates over the evolution of human music? What kinds of animals can synchronize to musical rhythms, and what are the key methodological issues for research in this area? This paper addresses these questions and proposes some refinements to the "vocal learning and rhythmic synchronization hypothesis." PMID:19673824

  16. Isochronal chaos synchronization of delay-coupled optoelectronic oscillators.

    PubMed

    Illing, Lucas; Panda, Cristian D; Shareshian, Lauren

    2011-07-01

    We study experimentally chaos synchronization of nonlinear optoelectronic oscillators with time-delayed mutual coupling and self-feedback. Coupling three oscillators in a chain, we find that the outer two oscillators always synchronize. In contrast, isochronal synchronization of the mediating middle oscillator is found only when self-feedback is added to the middle oscillator. We show how the stability of the isochronal solution of any network, including the case of three coupled oscillators, can be determined by measuring the synchronization threshold of two unidirectionally coupled systems. In addition, we provide a sufficient condition that guarantees global asymptotic stability of the synchronized solution.

  17. Synchronization of two self-excited double pendula

    NASA Astrophysics Data System (ADS)

    Koluda, P.; Perlikowski, P.; Czolczynski, Krzysztof; Kapitaniak, T.

    2014-04-01

    We consider the synchronization of two self-excited double pendula. We show that such pendula hanging on the same beam can have four different synchronous configurations. Our approximate analytical analysis allows us to derive the synchronization conditions and explain the observed types of synchronization. We consider an energy balance in the system and describe how the energy is transferred between the pendula via the oscillating beam, allowing thus the pendula synchronization. Changes and stability ranges of the obtained solutions with increasing and decreasing masses of the pendula are shown using path-following.

  18. Frequency synchronization of a frequency-hopped MFSK communication system

    NASA Technical Reports Server (NTRS)

    Huth, G. K.; Polydoros, A.; Simon, M. K.

    1981-01-01

    This paper presents the performance of fine-frequency synchronization. The performance degradation due to imperfect frequency synchronization is found in terms of the effect on bit error probability as a function of full-band or partial-band noise jamming levels and of the number of frequency hops used in the estimator. The effect of imperfect fine-time synchronization is also included in the calculation of fine-frequency synchronization performance to obtain the overall performance degradation due to synchronization errors.

  19. 21 CFR 529.1940 - Progesterone intravaginal inserts.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... synchronization of estrus in suckled beef cows and replacement beef and dairy heifers; for advancement of first... heifers. (B) For synchronization of estrus in lactating dairy cows. (C) For synchronization of the return... days. (ii) Indications for use. For induction of estrus in ewes (sheep) during seasonal anestrus....

  20. Synchronization of two identical and non-identical Rulkov models

    NASA Astrophysics Data System (ADS)

    Sun, Huijing; Cao, Hongjun

    2016-11-01

    In this paper, the synchronization of two chaotic Rulkov map-based neurons is taken into account. Firstly, based on the master stability function (MSF) analysis, the complete synchronization of two electrical coupled chaotic Rulkov neurons is investigated in detail. The two-dimensional parameter-space plot that displays directly the values of the MSF in different colors is numerically obtained. The numerical values of the MSF show that the two electrical coupled Rulkov neurons are likely to achieve the complete synchronization when each single neuron is in a silent state or a period-1 bursting state, while are unable to reach the complete synchronous state when each single neuron is in a chaotic bursting state or a spiking state. Secondly, Pearson's correlation coefficient is employed to measure the synchronization degree, which demonstrates the nonexistence of the complete synchronization for non-identical electrical coupled Rulkov neurons. Importantly, the complete synchronization can not be reached with the increase of the electrical coupling strength, which is different from the continuous-time neuronal models. Finally, based on the active control method, a synchronization scheme is presented to study the complete synchronization for two Rulkov neurons no matter whether they are identical or not. The scheme is also applied to investigate the anticipated synchronization and the lag synchronization for any two Rulkov neurons. Numerical simulations verify the correctness of our analytical results and the effectiveness of our methods.

  1. Spontaneous synchronization of arm motion between Japanese macaques.

    PubMed

    Nagasaka, Yasuo; Chao, Zenas C; Hasegawa, Naomi; Notoya, Tomonori; Fujii, Naotaka

    2013-01-01

    Humans show spontaneous synchronization of movements during social interactions; this coordination has been shown to facilitate smooth communication. Although human studies exploring spontaneous synchronization are increasing in number, little is known about this phenomenon in other species. In this study, we examined spontaneous behavioural synchronization between monkeys in a laboratory setting. Synchronization was quantified by changes in button-pressing behaviour while pairs of monkeys were facing one another. Synchronization between the monkeys was duly observed and it was participant-partner dependent. Further tests confirmed that the speed of button pressing changed to harmonic or sub-harmonic levels in relation to the partner's speed. In addition, the visual information from the partner induced a higher degree of synchronization than auditory information. This study establishes advanced tasks for testing social coordination in monkeys, and illustrates ways in which monkeys coordinate their actions to establish synchronization.

  2. System and method for time synchronization in a wireless network

    DOEpatents

    Gonia, Patrick S.; Kolavennu, Soumitri N.; Mahasenan, Arun V.; Budampati, Ramakrishna S.

    2010-03-30

    A system includes multiple wireless nodes forming a cluster in a wireless network, where each wireless node is configured to communicate and exchange data wirelessly based on a clock. One of the wireless nodes is configured to operate as a cluster master. Each of the other wireless nodes is configured to (i) receive time synchronization information from a parent node, (ii) adjust its clock based on the received time synchronization information, and (iii) broadcast time synchronization information based on the time synchronization information received by that wireless node. The time synchronization information received by each of the other wireless nodes is based on time synchronization information provided by the cluster master so that the other wireless nodes substantially synchronize their clocks with the clock of the cluster master.

  3. Prescribed performance synchronization for fractional-order chaotic systems

    NASA Astrophysics Data System (ADS)

    Liu, Heng; Li, Sheng-Gang; Sun, Ye-Guo; Wang, Hong-Xing

    2015-09-01

    In this paper the synchronization for two different fractional-order chaotic systems, capable of guaranteeing synchronization error with prescribed performance, is investigated by means of the fractional-order control method. By prescribed performance synchronization we mean that the synchronization error converges to zero asymptotically, with convergence rate being no less than a certain prescribed function. A fractional-order synchronization controller and an adaptive fractional-order synchronization controller, which can guarantee the prescribed performance of the synchronization error, are proposed for fractional-order chaotic systems with and without disturbances, respectively. Finally, our simulation studies verify and clarify the proposed method. Project supported by the National Natural Science Foundation of China (Grant Nos. 11401243 and 61403157), the Fundamental Research Funds for the Central Universities of China (Grant No. GK201504002), and the Natural Science Foundation for the Higher Education Institutions of Anhui Province of China (Grant No. KJ2015A256).

  4. Signal processing techniques for synchronization of wireless sensor networks

    NASA Astrophysics Data System (ADS)

    Lee, Jaehan; Wu, Yik-Chung; Chaudhari, Qasim; Qaraqe, Khalid; Serpedin, Erchin

    2010-11-01

    Clock synchronization is a critical component in wireless sensor networks, as it provides a common time frame to different nodes. It supports functions such as fusing voice and video data from different sensor nodes, time-based channel sharing, and sleep wake-up scheduling, etc. Early studies on clock synchronization for wireless sensor networks mainly focus on protocol design. However, clock synchronization problem is inherently related to parameter estimation, and recently, studies of clock synchronization from the signal processing viewpoint started to emerge. In this article, a survey of latest advances on clock synchronization is provided by adopting a signal processing viewpoint. We demonstrate that many existing and intuitive clock synchronization protocols can be interpreted by common statistical signal processing methods. Furthermore, the use of advanced signal processing techniques for deriving optimal clock synchronization algorithms under challenging scenarios will be illustrated.

  5. Synchronization in networks of spatially extended systems

    SciTech Connect

    Filatova, Anastasiya E.; Hramov, Alexander E.; Koronovskii, Alexey A.; Boccaletti, Stefano

    2008-06-15

    Synchronization processes in networks of spatially extended dynamical systems are analytically and numerically studied. We focus on the relevant case of networks whose elements (or nodes) are spatially extended dynamical systems, with the nodes being connected with each other by scalar signals. The stability of the synchronous spatio-temporal state for a generic network is analytically assessed by means of an extension of the master stability function approach. We find an excellent agreement between the theoretical predictions and the data obtained by means of numerical calculations. The efficiency and reliability of this method is illustrated numerically with networks of beam-plasma chaotic systems (Pierce diodes). We discuss also how the revealed regularities are expected to take place in other relevant physical and biological circumstances.

  6. Application of synchronous fluorescence to parchment characterization.

    PubMed

    Dolgin, Bella; Bulatov, Valery; Schechter, Israel

    2009-12-01

    A nondestructive method for quantitative parchment characterization and sensitive indication of its deterioration stage was developed. Synchronous fluorescence (SF) measurements were applied for the first time to parchment samples. The method provides detailed spectral features, which are useful for parchment characterization. The discrimination of parchment samples into groups (modern, historical, and artificially aged) was successfully performed. The SF spectra could be resolved into specific fluorophores, which were related to the parchment condition. The spectral data indicate a continuous change in the collagen-to-gelatin ratio during the aging process. Depth-resolved synchronous fluorescence spectra were also measured. The data indicate that parchments possess a layered structure, and the dominant fluorophore in the upper layer is different from those in the lower layers. Layer-resolved profiling allows for quantifying the contribution of each fluorophore in each given layer. This way, significant differences between modern, artificially aged, and historical samples can be observed.

  7. Statistical modeling approach for detecting generalized synchronization

    NASA Astrophysics Data System (ADS)

    Schumacher, Johannes; Haslinger, Robert; Pipa, Gordon

    2012-05-01

    Detecting nonlinear correlations between time series presents a hard problem for data analysis. We present a generative statistical modeling method for detecting nonlinear generalized synchronization. Truncated Volterra series are used to approximate functional interactions. The Volterra kernels are modeled as linear combinations of basis splines, whose coefficients are estimated via l1 and l2 regularized maximum likelihood regression. The regularization manages the high number of kernel coefficients and allows feature selection strategies yielding sparse models. The method's performance is evaluated on different coupled chaotic systems in various synchronization regimes and analytical results for detecting m:n phase synchrony are presented. Experimental applicability is demonstrated by detecting nonlinear interactions between neuronal local field potentials recorded in different parts of macaque visual cortex.

  8. Pursuit and Synchronization in Hydrodynamic Dipoles

    NASA Astrophysics Data System (ADS)

    Kanso, Eva; Tsang, Alan Cheng Hou

    2015-10-01

    We study theoretically the behavior of a class of hydrodynamic dipoles. This study is motivated by recent experiments on synthetic and biological swimmers in microfluidic Hele-Shaw type geometries. Under such confinement, a swimmer's hydrodynamic signature is that of a potential source dipole, and the long-range interactions among swimmers are obtained from the superposition of dipole singularities. Here, we recall the equations governing the positions and orientations of interacting asymmetric swimmers in doubly periodic domains and focus on the dynamics of pairs of swimmers. We obtain two families of "relative equilibria"-type solutions that correspond to pursuit and synchronization of the two swimmers. Interestingly, the pursuit mode is stable for large-tail swimmers, whereas the synchronization mode is stable for large-head swimmers. These results have profound implications on the collective behavior reported in several recent studies on populations of confined microswimmers.

  9. Noise suppressions in synchronized chaos lidars.

    PubMed

    Wu, Wen-Ting; Liao, Yi-Huan; Lin, Fan-Yi

    2010-12-01

    The noise suppressions in the chaos lidar (CLIDAR) and the synchronized chaos lidar (S-CLIDAR) systems with the optoelectronic feedback (OEF) and optical feedback (OF) schemes are studied numerically. Compared with the CLIDAR system, the S-CLIDAR system with the OEF scheme has better correlation coefficients in the large noise regime for SNR < 15 dB. For the S-CLIDAR system with the OF scheme, better detections are also achieved in wide ranges depending on the levels of the phase noise presented in the channel. To have the best synchronization and detection quality, the optimized conditions for the coupling and feedback strengths in the S-CLIDAR system are also discussed.

  10. Synchronized charge oscillations in correlated electron systems

    PubMed Central

    Shukla, Nikhil; Parihar, Abhinav; Freeman, Eugene; Paik, Hanjong; Stone, Greg; Narayanan, Vijaykrishnan; Wen, Haidan; Cai, Zhonghou; Gopalan, Venkatraman; Engel-Herbert, Roman; Schlom, Darrell G.; Raychowdhury, Arijit; Datta, Suman

    2014-01-01

    Strongly correlated phases exhibit collective carrier dynamics that if properly harnessed can enable novel functionalities and applications. In this article, we investigate the phenomenon of electrical oscillations in a prototypical MIT system, vanadium dioxide (VO2). We show that the key to such oscillatory behaviour is the ability to induce and stabilize a non-hysteretic and spontaneously reversible phase transition using a negative feedback mechanism. Further, we investigate the synchronization and coupling dynamics of such VO2 based relaxation oscillators and show, via experiment and simulation, that this coupled oscillator system exhibits rich non-linear dynamics including charge oscillations that are synchronized in both frequency and phase. Our approach of harnessing a non-hysteretic reversible phase transition region is applicable to other correlated systems exhibiting metal-insulator transitions and can be a potential candidate for oscillator based non-Boolean computing.

  11. Synchronous and Cogged Fan Belt Performance Assessment

    SciTech Connect

    Cutler, D.; Dean, J.; Acosta, J.

    2014-02-01

    The GSA Regional GPG Team commissioned the National Renewable Energy Laboratory (NREL) to perform monitoring of cogged V-belts and synchronous belts on both a constant volume and a variable air volume fan at the Byron G. Rodgers Federal Building and U.S. Courthouse in Denver, Colorado. These motor/fan combinations were tested with their original, standard V-belts (appropriately tensioned by an operation and maintenance professional) to obtain a baseline for standard operation. They were then switched to the cogged V-belts, and finally to synchronous belts. The power consumption by the motor was normalized for both fan speed and air density changes. This was necessary to ensure that the power readings were not influenced by a change in rotational fan speed or by the power required to push denser air. Finally, energy savings and operation and maintenance savings were compiled into an economic life-cycle cost analysis of the different belt options.

  12. Forced synchronization of autonomous dynamical Boolean networks

    SciTech Connect

    Rivera-Durón, R. R. Campos-Cantón, E.; Campos-Cantón, I.; Gauthier, Daniel J.

    2015-08-15

    We present the design of an autonomous time-delay Boolean network realized with readily available electronic components. Through simulations and experiments that account for the detailed nonlinear response of each circuit element, we demonstrate that a network with five Boolean nodes displays complex behavior. Furthermore, we show that the dynamics of two identical networks display near-instantaneous synchronization to a periodic state when forced by a common periodic Boolean signal. A theoretical analysis of the network reveals the conditions under which complex behavior is expected in an individual network and the occurrence of synchronization in the forced networks. This research will enable future experiments on autonomous time-delay networks using readily available electronic components with dynamics on a slow enough time-scale so that inexpensive data collection systems can faithfully record the dynamics.

  13. Electro-hydrodynamic synchronization of piezoelectric flags

    NASA Astrophysics Data System (ADS)

    Xia, Yifan; Doaré, Olivier; Michelin, Sébastien

    2016-08-01

    Hydrodynamic coupling of flexible flags in axial flows may profoundly influence their flapping dynamics, in particular driving their synchronization. This work investigates the effect of such coupling on the harvesting efficiency of coupled piezoelectric flags, that convert their periodic deformation into an electrical current. Considering two flags connected to a single output circuit, we investigate using numerical simulations the relative importance of hydrodynamic coupling to electrodynamic coupling of the flags through the output circuit due to the inverse piezoelectric effect. It is shown that electrodynamic coupling is dominant beyond a critical distance, and induces a synchronization of the flags' motion resulting in enhanced energy harvesting performance. We further show that this electrodynamic coupling can be strengthened using resonant harvesting circuits.

  14. Another look at synchronized neutrino oscillations

    NASA Astrophysics Data System (ADS)

    Akhmedov, Evgeny; Mirizzi, Alessandro

    2016-07-01

    In dense neutrino backgrounds present in supernovae and in the early Universe neutrino oscillations may exhibit complex collective phenomena, such as synchronized oscillations, bipolar oscillations and spectral splits and swaps. We consider in detail possible decoherence effects on the simplest of these phenomena - synchronized neutrino oscillations that can occur in a uniform and isotropic neutrino gas. We develop an exact formalism of spectral moments of the flavour spin vectors describing such a system and then apply it to find analytical approaches that allow one to study decoherence effects on its late-time evolution. This turns out to be possible in part due to the existence of the (previously unknown) exact conservation law satisfied by the quantities describing the considered neutrino system. Interpretation of the decoherence effects in terms of neutrino wave packet separation is also given, both in the adiabatic and non-adiabatic regimes of neutrino flavour evolution.

  15. Anticipated synchronization in neuronal network motifs

    NASA Astrophysics Data System (ADS)

    Matias, F. S.; Gollo, L. L.; Carelli, P. V.; Copelli, M.; Mirasso, C. R.

    2013-01-01

    Two identical dynamical systems coupled unidirectionally (in a so called master-slave configuration) exhibit anticipated synchronization (AS) if the one which receives the coupling (the slave) also receives a negative delayed self-feedback. In oscillatory neuronal systems AS is characterized by a phase-locking with negative time delay τ between the spikes of the master and of the slave (slave fires before the master), while in the usual delayed synchronization (DS) regime τ is positive (slave fires after the master). A 3-neuron motif in which the slave self-feedback is replaced by a feedback loop mediated by an interneuron can exhibits both AS and DS regimes. Here we show that AS is robust in the presence of noise in a 3 Hodgkin-Huxley type neuronal motif. We also show that AS is stable for large values of τ in a chain of connected slaves-interneurons.

  16. Synchronous imaging of coherent plasma fluctuations

    NASA Astrophysics Data System (ADS)

    Haskey, S. R.; Thapar, N.; Blackwell, B. D.; Howard, J.

    2014-03-01

    A new method for imaging high frequency plasma fluctuations is described. A phase locked loop and field programmable gate array are used to generate gating triggers for an intensified CCD camera. A reference signal from another diagnostic such as a magnetic probe ensures that the triggers are synchronous with the fluctuation being imaged. The synchronous imaging technique allows effective frame rates exceeding millions per second, good signal to noise through the accumulation of multiple exposures per frame, and produces high resolution images without generating excessive quantities of data. The technique can be used to image modes in the MHz range opening up the possibility of spectrally filtered high resolution imaging of MHD instabilities that produce sufficient light fluctuations. Some examples of projection images of plasma fluctuations on the H-1NF heliac obtained using this approach are presented here.

  17. Synchronous imaging of coherent plasma fluctuations.

    PubMed

    Haskey, S R; Thapar, N; Blackwell, B D; Howard, J

    2014-03-01

    A new method for imaging high frequency plasma fluctuations is described. A phase locked loop and field programmable gate array are used to generate gating triggers for an intensified CCD camera. A reference signal from another diagnostic such as a magnetic probe ensures that the triggers are synchronous with the fluctuation being imaged. The synchronous imaging technique allows effective frame rates exceeding millions per second, good signal to noise through the accumulation of multiple exposures per frame, and produces high resolution images without generating excessive quantities of data. The technique can be used to image modes in the MHz range opening up the possibility of spectrally filtered high resolution imaging of MHD instabilities that produce sufficient light fluctuations. Some examples of projection images of plasma fluctuations on the H-1NF heliac obtained using this approach are presented here.

  18. Social argumentation in online synchronous communication

    NASA Astrophysics Data System (ADS)

    Angiono, Ivan

    In education, argumentation has an increasing importance because it can be used to foster learning in various fields including philosophy, history, sciences, and mathematics. Argumentation is also at the heart of scientific inquiry. Many educational technology researchers have been interested in finding out how technologies can be employed to improve students' learning of argumentation. Therefore, many computer-based tools or argumentation systems have been developed to assist students in their acquisition of argumentation skills. While the argumentation systems incorporating online debating tools present a good resource in formal settings, there is limited research revealing what argumentative skills students are portraying in informal online settings without the presence of a moderator. This dissertation investigates the nature of argumentative practices in a massively multiplayer online game where the system successfully incorporates the authentic use of online synchronous communication tools and the patterns that emerge from the interplay between a number of contextual variables including synchronicity, interest, authenticity, and topical knowledge.

  19. Hidden imperfect synchronization of wall turbulence

    NASA Astrophysics Data System (ADS)

    Tardu, Sedat F.

    2010-03-01

    Instantaneous amplitude and phase concept emerging from analytical signal formulation is applied to the wavelet coefficients of streamwise velocity fluctuations in the buffer layer of a near wall turbulent flow. Experiments and direct numerical simulations show both the existence of long periods of inert zones wherein the local phase is constant. These regions are separated by random phase jumps. The local amplitude is globally highly intermittent, but not in the phase locked regions wherein it varies smoothly. These behaviors are reminiscent of phase synchronization phenomena observed in stochastic chaotic systems. The lengths of the constant phase inert (laminar) zones reveal a type I intermittency behavior, in concordance with saddle-node bifurcation, and the periodic orbits of saddle nature recently identified in Couette turbulence. The imperfect synchronization is related to the footprint of coherent Reynolds shear stress producing eddies convecting in the low buffer.

  20. EEG phase synchronization during hypnosis induction.

    PubMed

    Baghdadi, G; Nasrabadi, A M

    2012-05-01

    Hypnosis is a mental state or set of attitudes usually induced by a procedure known as hypnotic induction. In order to provide the basic physiological conditions for potentially successful hypnosis treatment of medical and psychological problems, the determination of a subject's hypnotizability level is important. Currently, the hypnotizability level is determined using different standard subjective tests. To avoid the different drawbacks of these subjective clinical tests, a practical objective method based on the correlation between electroencephalograph (EEG) phase synchronization and hypnosis susceptibility levels is presented in this study. This method can be used by clinicians instead of the traditional subjective methods to classify hypnotizability level. Thirty-two subjects with different hypnosis susceptibility levels contributed to this research. Using statistical analyses, it was concluded that, in highly hypnotizable people, the EEG phase synchronization between different paired channels, located on the frontal lobe, is significantly different from that in subjects with medium or low hypnotizability.