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Sample records for estrous synchronization protocols

  1. Concentrations of steroid hormones, estrous, ovarian and reproductive responses in sheep estrous synchronized with different prostaglandin-based protocols.

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    Fierro, S; Viñoles, C; Olivera-Muzante, J

    2016-04-01

    To determine estrous, ovarian and reproductive responses after different prostaglandin (PG)-based protocols, ewes were assigned to groups PG10, PG12, PG14 or PG16 (twoPG injections administered 10, 12, 14 or 16 days apart; respectively). Experiment I (n=132) was conducted to evaluate the estrous response, ovulation rate (OR), conception and fertility. Experiment II (n=24) was conducted to evaluate ovarian follicle growth, steroid concentrations and the interval from the second PG injection to estrus (PG-estrus) and ovulation (PG-ovulation). Estrous response was less with the PG16 (P0.05). From 8 to 4 days before estrus, progesterone (P4) concentrations were greater for the PG14 and PG16 than for the PG10 and PG12 (P<0.05) groups. There were more days where concentrations of P4 were above 3.18 nmol/L with the PG14 and PG16 than PG10 and PG12 (P<0.05) treatments. Use of the PG14 and PG16 treatments resulted in greater estradiol (E2) at estrus and 12h later than use of the PG10 and PG12 treatments. A positive correlation was observed between the duration of the luteal phase and maximum E2 concentrations, and between duration of the luteal phase and days with E2 concentrations above 10 pmol/L. Conception and fertility were greater with use of the PG14 compared with PG10 and PG12 (P<0.05) treatments. The administration of two PG injections 10, 12, 14 or 16 days apart resulted in different durations of the luteal phase that were positively associated with E2 concentrations and the reproductive outcome. The shorter luteal phases were associated with greater synchrony in time of estrus. The intervals for the variables PG-estrus, PG-ovulation and OR were similar among groups. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Evaluation of two progestogen-based estrous synchronization protocols in yearling heifers of Bos indicus × Bos taurus breeding.

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    McKinniss, E N; Esterman, R D; Woodall, S A; Austin, B R; Hersom, M J; Thatcher, W W; Yelich, J V

    2011-06-01

    Yearling Bos indicus × Bos taurus heifers (n = 410) from three locations, were synchronized with either the Select Synch/CIDR+timed-AI (SSC+TAI) or 7-11+timed-AI (7-11+TAI) treatments. On Day 0 of the experiment, within each location, heifers were equally distributed to treatments by reproductive tract score (RTS; Scale 1-5: 1 = immature, 5 = estrous cycling) and body condition score. The 7-11+TAI treatment consisted of melengestrol acetate (0.5 mg/head/d) from Days 0 to 7, with PGF(2α) (25 mg im) on Day 7, GnRH (100 μg im) on Day 11, and PGF(2α) (25 mg im) on Day 18. The SSC+TAI heifers received the same carrier supplement (without MGA) from Days 0 to 7, and on Day 11 they were given 100 μg GnRH and an intravaginal CIDR (containing 1.38 g progesterone). The CIDR were removed on Day 18, concurrent with 25 mg PGF(2α) im For both treatments, estrus was visually detected for 1 h twice daily (0700 and 1600 h) for 72 h after PGF(2α), with AI done 6 to 12 h after a detected estrus. Non-responders were timed-AI and received GnRH (100 μg im) 72 to 76 h post PGF(2α). The 7-11+TAI heifers had a greater (P conception rate (47.0 vs 31.3%), and synchronized pregnancy rate (33.5 vs 24.8%) compared to SSC+TAI heifers, respectively. Heifers exhibiting estrus at 60 h (61.7%) had a greater (P conception rate compared to heifers that exhibited estrus at ≤ 36 (35.3%), 48 (31.6%), and 72 h (36.2%), which were similar (P > 0.05) to each other. As RTS increased from ≤ 2 to ≥ 3, estrous response, conception rate, synchronized pregnancy rate, and 30 d pregnancy rate all increased (P rates compared to SSC+TAI treatment in yearling Bos indicus × Bos taurus heifers. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Induction and estrous synchronization during the non-breeding season in Saanen goats

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    Anamaria Luciana Blaga Petrean

    2016-11-01

    Full Text Available The purpose of this study was to perform the induction and estrous synchronization of Saanen goats in the non-breeding season. The study was conducted from July 2014 - April 2015 on 77 Saanen goats, aged between 1.5 to 5 years. The goats were divided into three experimental groups: in group I (n =37 goats intravaginal sponge (Ovigest containing 60 mg of MPA was left in the vagina for 14 days. Immediately after sponge removal the animals received two injections: prostaglandin (Prosolvin at the dose of 0.75 mg (1 ml/animal and PMSG hormone (Folligon at the dose of 500 IU/animal. In group II (n=20 induction and estrous synchronization was performed using synthetic prostaglandin (Proliz - 1 ml containing 0.2 mg isopropyl ester of cloprostenol and 9 mg benzyl alcohol at the dose of 0.5 ml/animal. The group III (n=20 was considered the control group and estrous synchronization was performed using fertile bucks. In group I the results showed that all goats expressed signs of estrous. The average value of the estrous interval was 33 hours and the average of estrous duration was 20 hours. The number of kids obtained in group I was 94, and prolificacy was P (% = 2.54. In group II and III was not observed occurrence of estrous. Induction and estrous synchronization show economic benefits by shortening the time needed for pregnancy installation, possibility of births grouping, preparation and organization of mating, only if we use a hormone associated protocol and we rigorous respect therapy steps.

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

    Science.gov (United States)

    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  0.1) 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 compared to heifers in HRTS-DPGF group (P reproductive performance was reduced compared with other protocols used in this study. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Effects of GnRH administration on ovulation and fertility in ewes subjected to estrous synchronization

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    Amanda dos Santos Cavalcanti

    2012-06-01

    Full Text Available The objective of this study was to verify the effects of GnRH on ovulation and pregnancy of ewes subjected to a short-term synchronization of estrus. Santa Inês and crossbred Santa Inês/Dorper ewes received 60 mg MAP sponges during 6 days plus 300 IU eCG and 30 µg d-cloprostenol 24 h prior to sponge withdrawal (SW. Ewes were assigned to receive 0.9% NaCl solution (Tcontrol; n = 32 or 25 µg GnRH (licerelin, T GnRH; n = 34 24 hours after SW. Each group was assigned to intrauterine insemination by laparoscopy (n = 25 or to natural mating (n = 41. Artificial insemination was performed with a single dose of fresh semen. For controlled mating, females were exposed to males 12, 24, 36 and 48 hours after SW. Ten females per treatment were subjected to transrectal ultrasound examination at 12-hour intervals (SW to 60 hours after. Estrous response (100.0% vs 95.2%, interval from SW to estrus (32.9±7.4 vs 29.8±6.9 hours, estrous length (37.4±9.0 vs 31.5±10.4 hours, pregnancy rates (57.0% vs 41.0%, ovulation rate (100.0% vs 90.0%, number of ovulations/ewe (1.1±0.3 vs 1.2±0.4, maximum follicular diameter (6.4±0.7 vs 6.1±0.6 mm, interval from SW to ovulation (59.1±3.5 vs 58.4±3.5 hours did not differ between Tcontrol and T GnRH, respectively. Administration of GnRH 24 hours after SW does not improve ovulation or pregnancy rate in estrous synchronization in ewes.

  6. Characterization of endocrine events during the periestrous period in sheep after estrous synchronization with controlled internal drug release (CIDR) device.

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    Van Cleeff, J; Karsch, F J; Padmanabhan, V

    1998-01-01

    The Controlled Internal Drug Releasing (CIDR) device is an intravaginal pessary containing progesterone (P4) designed for synchronizing estrus in ruminants. To date, there has been little information available on the timing, duration, and quality of the follicular phase after CIDR removal and how those characteristics compare with natural periovulatory endocrine events. The present communication relates the results of methods we used to characterize the endocrine events that followed CIDR synchronization. Breeding-season ewes were given an injection (10 mg) of Lutalyse (PGF2 alpha), and then studied during three consecutive estrous cycles, beginning in the luteal phase after the estrus induced by PGF2 alpha. Cycle 1 estrus was synchronized with 1 CIDR (Type G) inserted for 8 d beginning 10 d after PGF2 alpha. Cycles 2 and 3 were synchronized with two CIDRs for 8 d beginning 10 d after previous CIDR removal. Cycle 1 estrous behavior and serum gonadotropins showed a follicular phase (the interval from CIDR withdrawal to gonadotropin surge [surge] peak) of 38.2 +/- 1.5 hr. Two CIDRs lengthened the interval to 46.2 +/- 1.5 hr (P synchronization concentrated surges within a 24-hr period in 92% of the ewes in Cycles 1 and 2. Cycles 3 ewes were euthanized at estimated luteal, early follicular, late follicular, LH surge, and secondary FSH rise timepoints. Endocrine data and ovaries showed that 88% of the ewes synchronized with two CIDRs were in the predicted stage of the estrous cycle. These data demonstrate that the CIDR device applied during the luteal phase effectively synchronizes estrus and results in a CIDR removal-to-surge interval of similar length to a natural follicular phase.

  7. Starting Ovsynch protocol on day 6 of first postpartum estrous cycle increased fertility in dairy cows by affecting ovarian response during heat stress.

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    Dirandeh, E

    2014-10-01

    The objective was to compare fertility in cows using an Ovsynch protocol starting on day 6 of first postpartum estrous cycle with an Ovsynch protocol initiated at random stages of the estrous cycle during heat stress (temperature-humidity index (THI)=77-83). Cows (n=459) at the beginning of the lactation period were randomly assigned to time-of-ovulation synchronization treatments: (1) control, Ovsynch (first GnRH treatment, PGF2α treatment 7 days later, second GnRH treatment 56 h later, and TAI 16 h later), initiated at random stages of the estrous cycle (40 ± 2 days postpartum, n=224) and (2) Ovsynch initiated on day 6 of first postpartum estrous cycle (estrus=day 0) based on detection of the first estrus after day 30 postpartum (O6, 35 ± 2 postpartum, n=235). Statistical analyses were conducted using SAS. The percentage of cows responding to the initial GnRH injection using the Ovsynch protocol was greater with the O6 treatment compared to the control treatment (60.4% compared with 52.6%). The percentage of cows having a corpus luteum (CL) on the day of the PGF2α injection was not different among treatments (control=87.0% and O6=90.2%, respectively). Also more cows in the O6 treatment group responded to the second GnRH injection of the Ovsynch protocol compared with control treatments (82.5% compared with 75.8%). Treatment affected the percentage of cows diagnosed pregnant at 32 ± 0.7 days and 60 ± 3 days after the resynchronized timing of AI but pregnancy losses (5.3% compared with 6.8%) did not differ between treatment groups. It is concluded that initiating the Ovsynch protocol 6 days after estrus during the first 40 days postpartum resulted in a greater pregnancy rate at the synchronized estrus and increased fertility compared with control cows during heat stress. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Seasonality, estrous cycle characterization, estrus synchronization, semen cryopreservation, and artificial insemination in the Pacific white-sided dolphin (Lagenorhynchus obliquidens).

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    Robeck, T R; Steinman, K J; Greenwell, M; Ramirez, K; Van Bonn, W; Yoshioka, M; Katsumata, E; Dalton, L; Osborn, S; O'Brien, J K

    2009-08-01

    The reproductive physiology of the Pacific white-sided dolphin, Lagenorhynchus obliquidens, was characterized to facilitate the development of artificial insemination (AI) using cryopreserved spermatozoa. Specific objectives were to: 1) describe reproductive seasonality of the Pacific white sided dolphins; 2) describe urinary LH and ovarian steroid metabolites during the estrous cycle; 3) correlate LH and ovarian steroidal metabolite patterns to ultrasound-monitored follicular growth and ovulation; and 4) assess the efficacy of synchronizing estrus, sperm collection/cryopreservation, and intrauterine insemination. Ovulations (64%, n=37) and conceptions (83%, n=18) occurred from August to October. Peak mean serum testosterone (24 ng/ml), cross-sectional testicular area (41.6 cm(2)), and sperm concentration (144.3 x 10(7) sperm/ml) occurred in July, August, and September respectively. Spermatozoa were only found in ejaculates from July to October. Estrous cycles (n=22) were 31 d long and were comprised of a 10 d follicular and 21 d luteal phase. Ovulation occurred 31.2 h after the onset of the LH surge and 19.3 h after the LH peak. Follicular diameter and circumference within 12 h of ovulation were 1.52 and 4.66 cm respectively. Estrus synchronization attempts with altrenogest resulted in 17 (22%) ovulatory cycles with ovulation occurring 21 d post-altrenogest. Ten AI attempts using cryopreserved semen resulted in five pregnancies (50%). The mean gestation length was 356 days (range 348-367). These data provide new information on the Pacific white-sided dolphin's reproductive physiology and collectively enabled the first application of AI in this species.

  9. Increased cleavage and blastocyst rate in ewes treated with bovine somatotropin 5 days before the end of progestin-based estrous synchronization.

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    Montero-Pardo, A; Hernández-Cerón, J; Rojas-Maya, S; Valencia, J; Rodríguez-Cortez, A; Gutiérrez, C G

    2011-05-01

    Treatment with bovine somatotropin (bST) during estrous synchronization increased fertility and prolificacy in sheep. In the present study, a single dose of bST 5 days before the end of progestin treatment improved cleavage and embryo development. Stage of estrous cycle was synchronized in ewes (n=32) with progestin and superovulation was induced by use of FSH. Five days before the end of progestin treatment, ewes were randomly assigned to two groups: bST group (n=16) received a depot injection of 125 mg of bST sc (Lactotropina, Elanco, México) and the control group (n=16) received saline solution. Estrous was detected with rams fitted with an apron every 2 h and estrous sheep were mated every 8 h whilst in estrous. Embryos were recovered on Day 7 post mating, assessed microscopically and fixed in 4% paraformaldehyde. Cell number in blastocysts was counted after Hoechst 33342 staining. Plasma concentrations of IGF-I, insulin and progesterone were determined in eight sheep per group from the day of bST treatment to the day of embryo recovery. Cleavage rate, percentage of transferable embryos (transferable embryos/cleaved) and percentage of embryos reaching the blastocyst stage (blastocyst/cleaved) were compared between groups by logistic regression. IGF-I, insulin and progesterone plasma concentrations were analyzed by ANOVA for repeated measurements and cell number by ANOVA. Cleavage rate was greater (Psheep. Plasma concentrations of IGF-I and insulin were greater (Pprogesterone concentrations (P=0.5). It is concluded that bST injection 5 days before progestin removal increases cleavage rate and the proportion of embryos that reach the blastocyst stage. These effects are associated with an increase in IGF-I and insulin concentrations. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. A single dose of bovine somatotropin 5 days before the end of progestin-based estrous synchronization increases prolificacy in sheep.

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    Carrillo, F; Hernández-Cerón, J; Orozco, V; Hernández, J A; Gutiérrez, C G

    2007-11-01

    Bovine somatotropin (bST) enhances ovarian follicular and embryonic development in sheep and cattle. In the present study, the objective was to assess whether bST given 5 days before the end of progestin-based estrous synchronization improves prolificacy and lambing rate in sheep. Pelibuey ewes (n=92) exhibiting estrous cycles at regular intervals received an intravaginal sponge containing 45mg of FGA for 12 days. Five days before sponge withdrawal, ewes were treated with either 125mg of bST sc (bST group; n=47) or saline solution (control; n=45). After the sponge was removed, ewes were observed for estrus and subsequently mated twice. Lambing rate and prolificacy was determined at birth. Blood samples were taken from the time of treatment until day 15 after estrus in eight ewes from the bST group and nine from the control group. Concentrations of IGF-I were determined by immunoradiometric assay and progesterone by RIA. Treatment with bST increased (P0.05). IGF-I concentrations were greater (PProgesterone concentrations did not vary (P>0.05) between groups. It is concluded that a single dose of bST 5 days before progestin withdrawal increases lambing rate and prolificacy in sheep. These effects are associated with an increase in circulating concentrations of IGF-I.

  11. Permanent synchronization of camcorders via LANC protocol

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    Vrancic, Damir; Smith, Steven L.

    2006-02-01

    A device, which keeps two camcorders permanently in synchronization, has been developed. The mentioned device uses LANC (CONTROL-L) camcorder's inputs for synchronization. It enables controlling of two camcorders simultaneously via built-in buttons, by using external LANC remote controller and/or by the PC via serial (RS232) communication. Since device requires LANC inputs on camcorders or ACC inputs on still cameras, it can be used on some camcorders produced by manufacturers Sony and Canon or some still cameras produced by Sony. The device initially synchronizes camcorders or still cameras by applying arbitrarily delayed power-up pulses on LANC (ACC) inputs. Then, on user demand, the camcorders can be permanently synchronized (valid only for some camcorders produced by Sony). The effectiveness of the proposed device is demonstrated by several experiments on three types of camcorders (DCR-TRV900E, HDR-HC1, HVR-Z1U) and one type of still camera (DSC-V1). The electronic schemes, PCB layouts, firmware and communication programs are freely available (under GPL licence).

  12. Computer network time synchronization the network time protocol

    CERN Document Server

    Mills, David L

    2006-01-01

    What started with the sundial has, thus far, been refined to a level of precision based on atomic resonance: Time. Our obsession with time is evident in this continued scaling down to nanosecond resolution and beyond. But this obsession is not without warrant. Precision and time synchronization are critical in many applications, such as air traffic control and stock trading, and pose complex and important challenges in modern information networks.Penned by David L. Mills, the original developer of the Network Time Protocol (NTP), Computer Network Time Synchronization: The Network Time Protocol

  13. A Self-Stabilizing Synchronization Protocol for Arbitrary Digraphs

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    Malekpour, Mahyar R.

    2011-01-01

    This paper presents a self-stabilizing distributed clock synchronization protocol in the absence of faults in the system. It is focused on the distributed clock synchronization of an arbitrary, non-partitioned digraph ranging from fully connected to 1-connected networks of nodes while allowing for differences in the network elements. This protocol does not rely on assumptions about the initial state of the system, other than the presence of at least one node, and no central clock or a centrally generated signal, pulse, or message is used. Nodes are anonymous, i.e., they do not have unique identities. There is no theoretical limit on the maximum number of participating nodes. The only constraint on the behavior of the node is that the interactions with other nodes are restricted to defined links and interfaces. This protocol deterministically converges within a time bound that is a linear function of the self-stabilization period. We present an outline of a deductive proof of the correctness of the protocol. A bounded model of the protocol was mechanically verified for a variety of topologies. Results of the mechanical proof of the correctness of the protocol are provided. The model checking results have verified the correctness of the protocol as they apply to the networks with unidirectional and bidirectional links. In addition, the results confirm the claims of determinism and linear convergence. As a result, we conjecture that the protocol solves the general case of this problem. We also present several variations of the protocol and discuss that this synchronization protocol is indeed an emergent system.

  14. ESTROUS SYNCHRONIZATION TO FIXED-TIME ARTIFICIAL INSEMINATION ASSOCIATED TO TEMPORARY OR DEFINITIVE EARLY WEANNING IN BEEF COWS SINCRONIZAÇÃO DE ESTROS PARA IATF ASSOCIADA AO DESMAME TEMPORÁRIO OU ANTECIPADO EM VACAS DE CORTE

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    Reinaldo Leopoldino Souza Neto

    2009-09-01

    Full Text Available The objective of this experiment was to determine the reproductive performance of suckled beef cows in programs of artificial insemination (AI submitted to definitive early or temporary weaning (EW or TW and estrous synchronization protocol to fixed-time artificial insemination (FTAI. Two-hundred and five Angus x Nelore cows body with condition score 2.6±0.4 and post-partum period between 54 and 122 days were used in the trial. After EW, one-hundred, fifty three cows were separated three groups according to the AI or FTAI protocol. A group of cows was artificial inseminated according estrous detection after 10 days of definitive weaning during a period of 30 days (EW-AI, n= 53. Estrous synchronization programs to FTAI were carried out in two groups in different moments after EW. In the group EW-FTAI (n= 50, cows were treated at the moment calves were removed while in EW-FTAI 10 (n= 50 the hormonal treatment began 10 days later.  The hormonal treatment consisted of an intravaginal implant containing 1,9g of Progesterone, for 8 days, and an injection of  Estradiol benzoate (EB, 2mg, im. When the dispositives were removed, 75mcg of Cloprostenol were injected, im, and after 24 hours, 1mg of EB, im. Cows were fixed-time artificial inseminated 52 to 56 hours after implants removal. In TW-FTAI group (n= 52, cows were treated with the same hormonal therapy, but a temporary weaning of 60 hours was done after the implant removal and the FTAI moment. The breeding season was 60 days in EW-FTAI and TW-FTAI groups, 50 days in EW-FTAI10 group and 30 days in EW-AI group. In a sample of 20% of cows ovaries were scanned by ultrasound and it was determined that 55% of the cows were in anestrous. Follicular diameters were determined at beginning of hormonal treatment and at FTAI moment in cows submitted to estrous synchronization (EW-FTAI= 10, EW-FTAI10= 10 and TW-FTAI= 10 by ultrasound. The means of follicular diameters were not different (P>0.05 between groups

  15. A proportional integral estimator-based clock synchronization protocol for wireless sensor networks.

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    Yang, Wenlun; Fu, Minyue

    2017-11-01

    Clock synchronization is an issue of vital importance in applications of WSNs. This paper proposes a proportional integral estimator-based protocol (EBP) to achieve clock synchronization for wireless sensor networks. As each local clock skew gradually drifts, synchronization accuracy will decline over time. Compared with existing consensus-based approaches, the proposed synchronization protocol improves synchronization accuracy under time-varying clock skews. Moreover, by restricting synchronization error of clock skew into a relative small quantity, it could reduce periodic re-synchronization frequencies. At last, a pseudo-synchronous implementation for skew compensation is introduced as synchronous protocol is unrealistic in practice. Numerical simulations are shown to illustrate the performance of the proposed protocol. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  16. Evaluation of Two Estrus Synchronization Protocols in Dairy Cattle at North Shoa Zone Ethiopia

    OpenAIRE

    Chanyalew, Yeshimebet; Zewde, Tesfaye; Gatew, Hulunim; Girma, Lina; Kassa, Getachew; Demis, Chekol; Bihon, Amare; Tsegaye, Yeshak

    2017-01-01

    This study was initiated to change the hesitation of the farmer on the effectiveness of estrus synchronization under their (Ethiopian small holder) livestock management system using two synchronization protocols. Non-pregnant animals with normal reproductive tract and that fulfilled the preconditions for estrus synchronization were considered for treatment & assigned into two synchronization protocols (single PGF2α injection; and double PGF2α injection). Among 94 (27 heifer and 67 cows) synch...

  17. A Self-Stabilizing Hybrid-Fault Tolerant Synchronization Protocol

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    Malekpour, Mahyar R.

    2014-01-01

    In this report we present a strategy for solving the Byzantine general problem for self-stabilizing a fully connected network from an arbitrary state and in the presence of any number of faults with various severities including any number of arbitrary (Byzantine) faulty nodes. Our solution applies to realizable systems, while allowing for differences in the network elements, provided that the number of arbitrary faults is not more than a third of the network size. The only constraint on the behavior of a node is that the interactions with other nodes are restricted to defined links and interfaces. Our solution does not rely on assumptions about the initial state of the system and no central clock nor centrally generated signal, pulse, or message is used. Nodes are anonymous, i.e., they do not have unique identities. We also present a mechanical verification of a proposed protocol. A bounded model of the protocol is verified using the Symbolic Model Verifier (SMV). The model checking effort is focused on verifying correctness of the bounded model of the protocol as well as confirming claims of determinism and linear convergence with respect to the self-stabilization period. We believe that our proposed solution solves the general case of the clock synchronization problem.

  18. Bit Level Synchronized MAC Protocol for Multireader RFID Networks

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    Namboodiri Vinod

    2010-01-01

    Full Text Available The operation of multiple RFID readers in close proximity results in interference between the readers. This issue is termed the reader collision problem and cannot always be solved by assigning them to different frequency channels due to technical and regulatory limitations. The typical solution is to separate the operation of such readers across time. This sequential operation, however, results in a long delay to identify all tags. We present a bit level synchronized (BLSync MAC protocol for multi-reader RFID networks that allows multiple readers to operate simultaneously on the same frequency channel. The BLSync protocol solves the reader collision problem by allowing all readers to transmit the same query at the same time. We analyze the performance of using the BLSync protocol and demonstrate benefits of 40%–50% in terms of tag reading delay for most settings. The benefits of BLSync, first demonstrated through analysis, are then validated and quantified through simulations on realistic reader-tag layouts.

  19. Byzantine-fault tolerant self-stabilizing protocol for distributed clock synchronization systems

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    Malekpour, Mahyar R. (Inventor)

    2010-01-01

    A rapid Byzantine self-stabilizing clock synchronization protocol that self-stabilizes from any state, tolerates bursts of transient failures, and deterministically converges within a linear convergence time with respect to the self-stabilization period. Upon self-stabilization, all good clocks proceed synchronously. The Byzantine self-stabilizing clock synchronization protocol does not rely on any assumptions about the initial state of the clocks. Furthermore, there is neither a central clock nor an externally generated pulse system. The protocol converges deterministically, is scalable, and self-stabilizes in a short amount of time. The convergence time is linear with respect to the self-stabilization period.

  20. On the theoretical gap between synchronous and asynchronous MPC protocols

    DEFF Research Database (Denmark)

    Beerliová-Trubíniová, Zuzana; Hirt, Martin; Nielsen, Jesper Buus

    2010-01-01

    that in the cryptographic setting (with setup), the sole reason for it is the distribution of inputs: given an oracle for input distribution, cryptographically-secure asynchronous MPC is possible with the very same condition as synchronous MPC, namely t ..., we show that such an input-distribution oracle can be reduced to an oracle that allows each party to synchronously broadcast one single message. This means that when one single round of synchronous broadcast is available, then asynchronous MPC is possible at the same condition as synchronous MPC...

  1. Implementation of anomaly detection algorithms for detecting transmission control protocol synchronized flooding attacks

    CSIR Research Space (South Africa)

    Mkuzangwe, NNP

    2015-08-01

    Full Text Available This work implements two anomaly detection algorithms for detecting Transmission Control Protocol Synchronized (TCP SYN) flooding attack. The two algorithms are an adaptive threshold algorithm and a cumulative sum (CUSUM) based algorithm...

  2. Microbiological and functional evaluation of an alternative device (OB® for estrous synchronization in ewes Avaliação microbiológica e funcional de um dispositivo vaginal alternativo (OB® para sincronização de cio em ovelhas

    Directory of Open Access Journals (Sweden)

    Leonardo Tondello Martins

    2010-02-01

    Full Text Available The use of synthetic progestagens released by vaginal devices is an important tool to overcome the reproductive seasonality in sheep, but cost and/or subsequent vaginitis are limiting factors for their use. To identify economic, simple and innocuous alternative vaginal devices for estrous synchronization/induction protocols in sheep, this study aimed to evaluate the microbiological and functional viability of the human vaginal tampons (OB® impregnated with medroxyprogesterone acetate (MAP on reproductive performance of ewes. The study compared them with commercial vaginal inserts (CIDR® and polyurethane sponges impregnated with MAP. In Experiment 1, the device loss rate, the degree of vaginitis during the device removal, the count and identification of bacterial colonies at the device insertion and removal, and efficiency in estrous synchronization and estrus temporal distribution were evaluated. Pubertal ewes at the beginning of the breeding season were randomly allocated to three experimental groups: CIDR®, PSP (polyurethane sponge and OB®. No device losses occurred in any group, but the use of OB® caused milder signs of vaginitis than polyurethane sponges, with a similar vaginal bacterial growth and microbiota than the CIDR group. The estrus distribution was more disperse in the CIDR than PSP or OB groups. In Experiment 2, pregnancy rates using CIDR® or OB® devices were compared, with estrus manifestation (85.4% and 89.8% and pregnancy rates (58.3% and 49.0% being similar between groups (P>0.05, respectively. In conclusion, the use of human intra-vaginal tampons (OB® impregnated with MAP was proven highly hygienic, practical and effective as a low-cost alternative for estrous synchronization and AI in sheep.O uso de progestágeno sintético liberado por pessários vaginais é uma importante ferramenta para suplantar a sazonalidade reprodutiva em ovelhas. Todavia, seu uso é limitado pelo custo ou pelas subsequentes vaginites. Na busca

  3. The use of prostaglandins in controlling estrous cycle of the ewe: a review.

    Science.gov (United States)

    Fierro, Sergio; Gil, Jorge; Viñoles, Carolina; Olivera-Muzante, Julio

    2013-02-01

    This review considers the use of prostaglandin F(2α) and its synthetic analogues (PG) for controlling the estrous cycle of the ewe. Aspects such as phase of the estrus cycle, PG analogues, PG doses, ovarian follicle development pattern, CL formation, progesterone synthesis, ovulation rate, sperm transport, embryo quality, and fertility rates after PG administration are reviewed. Furthermore, protocols for estrus synchronization and their success in timed AI programs are discussed. Based on available information, the ovine CL is refractory to PG treatment for up to 2 days after ovulation. All PG analogues are effective when an appropriate dose is given; in that regard, there is a positive association between the dose administered and the proportion of ewes detected in estrus. Follicular response after PG is dependent on the phase of the estrous cycle at treatment. Altered sperm transport and low pregnancy rates are generally reported. However, reports on alteration of the steroidogenic capacity of preovulatory follicles, ovulation rate, embryo quality, recovery rates, and prolificacy, are controversial. Although various PG-based protocols can be used for estrus synchronization, a second PG injection improves estrus response when the stage of the estrous cycle at the first injection is unknown. The estrus cycle after PG administration has a normal length. Prostaglandin-based protocols for timed AI achieved poor reproductive outcomes, but increasing the interval between PG injections might increase pregnancy rates. Attempts to improve reproductive outcomes have been directed to provide a synchronized LH surge: use of different routes of AI (cervical or intrauterine), different PG doses, and increased intervals between PG injections. Finally we present our point of view regarding future perspectives on the use of PG in programs of controlled sheep reproduction. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Space Network Time Distribution and Synchronization Protocol Development for Mars Proximity Link

    Science.gov (United States)

    Woo, Simon S.; Gao, Jay L.; Mills, David

    2010-01-01

    Time distribution and synchronization in deep space network are challenging due to long propagation delays, spacecraft movements, and relativistic effects. Further, the Network Time Protocol (NTP) designed for terrestrial networks may not work properly in space. In this work, we consider the time distribution protocol based on time message exchanges similar to Network Time Protocol (NTP). We present the Proximity-1 Space Link Interleaved Time Synchronization (PITS) algorithm that can work with the CCSDS Proximity-1 Space Data Link Protocol. The PITS algorithm provides faster time synchronization via two-way time transfer over proximity links, improves scalability as the number of spacecraft increase, lowers storage space requirement for collecting time samples, and is robust against packet loss and duplication which underlying protocol mechanisms provide.

  5. Distributed synchronization of networked drive-response systems: A nonlinear fixed-time protocol.

    Science.gov (United States)

    Zhao, Wen; Liu, Gang; Ma, Xi; He, Bing; Dong, Yunfeng

    2017-11-01

    The distributed synchronization of networked drive-response systems is investigated in this paper. A novel nonlinear protocol is proposed to ensure that the tracking errors converge to zeros in a fixed-time. By comparison with previous synchronization methods, the present method considers more practical conditions and the synchronization time is not dependent of arbitrary initial conditions but can be offline pre-assign according to the task assignment. Finally, the feasibility and validity of the presented protocol have been illustrated by a numerical simulation. Copyright © 2017. Published by Elsevier Ltd.

  6. Re-verification of a Lip Synchronization Protocol using Robust Reachability

    Directory of Open Access Journals (Sweden)

    Piotr Kordy

    2010-03-01

    Full Text Available The timed automata formalism is an important model for specifying and analysing real-time systems. Robustness is the correctness of the model in the presence of small drifts on clocks or imprecision in testing guards. A symbolic algorithm for the analysis of the robustness of timed automata has been implemented. In this paper, we re-analyse an industrial case lip synchronization protocol using the new robust reachability algorithm. This lip synchronization protocol is an interesting case because timing aspects are crucial for the correctness of the protocol. Several versions of the model are considered: with an ideal video stream, with anchored jitter, and with non-anchored jitter.

  7. A Self-Stabilizing Distributed Clock Synchronization Protocol for Arbitrary Digraphs

    Science.gov (United States)

    Malekpour, Mahyar R.

    2011-01-01

    This report presents a self-stabilizing distributed clock synchronization protocol in the absence of faults in the system. It is focused on the distributed clock synchronization of an arbitrary, non-partitioned digraph ranging from fully connected to 1-connected networks of nodes while allowing for differences in the network elements. This protocol does not rely on assumptions about the initial state of the system, other than the presence of at least one node, and no central clock or a centrally generated signal, pulse, or message is used. Nodes are anonymous, i.e., they do not have unique identities. There is no theoretical limit on the maximum number of participating nodes. The only constraint on the behavior of the node is that the interactions with other nodes are restricted to defined links and interfaces. We present an outline of a deductive proof of the correctness of the protocol. A model of the protocol was mechanically verified using the Symbolic Model Verifier (SMV) for a variety of topologies. Results of the mechanical proof of the correctness of the protocol are provided. The model checking results have verified the correctness of the protocol as they apply to the networks with unidirectional and bidirectional links. In addition, the results confirm the claims of determinism and linear convergence. As a result, we conjecture that the protocol solves the general case of this problem. We also present several variations of the protocol and discuss that this synchronization protocol is indeed an emergent system.

  8. Estrous cycle regulatory mechanisms of the uterus are altered in cows that do not demonstrate behavioral estrus during an ovulation induction protocol

    Science.gov (United States)

    Estrus is the start of an estrous cycle in cows, and triggers several precisely timed events including receptivity to the bull, ovulation, conception, formation of the corpus luteum, and recognition of pregnancy. In the absence of a pregnancy signal, the corpus luteum (CL) must regress in response ...

  9. Investigation of implementing a synchronization protocol under multiprocessors hierarchical scheduling

    NARCIS (Netherlands)

    Nemati, F.; Behnam, M.; Bril, R.J.

    2009-01-01

    In the multi-core and multiprocessor domain, there has been considerable work done on scheduling techniques assuming that real-time tasks are independent. In practice a typical real-time system usually share logical resources among tasks. However, synchronization in the multiprocessor area has not

  10. An Energy-efficient Clock Synchronization Protocol for Wireless Sensor Networks

    OpenAIRE

    Albu, Roxana; Labit, Yann; Thierry, Gayraud; Pascal, Berthou

    2010-01-01

    5p.; International audience; The behavior of Wireless Sensor Networks (WSN) is nowadays widely analyzed. One of the most important issues is related to their energy consumption, as this has a major impact on the network lifetime. Another important application requirement is to ensure data sensing synchronization, which leads to additional energy consumption as a high number of messages is sent and received at each node. Our proposal consists in implementing a combined synchronization protocol...

  11. Software Modules for the Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol

    Science.gov (United States)

    Woo, Simon S.; Veregge, John R.; Gao, Jay L.; Clare, Loren P.; Mills, David

    2012-01-01

    The Proximity-1 Space Link Interleaved Time Synchronization (PITS) protocol provides time distribution and synchronization services for space systems. A software prototype implementation of the PITS algorithm has been developed that also provides the test harness to evaluate the key functionalities of PITS with simulated data source and sink. PITS integrates time synchronization functionality into the link layer of the CCSDS Proximity-1 Space Link Protocol. The software prototype implements the network packet format, data structures, and transmit- and receive-timestamp function for a time server and a client. The software also simulates the transmit and receive-time stamp exchanges via UDP (User Datagram Protocol) socket between a time server and a time client, and produces relative time offsets and delay estimates.

  12. Computer network time synchronization the network time protocol on earth and in space

    CERN Document Server

    Mills, David L

    2010-01-01

    Carefully coordinated, reliable, and accurate time synchronization is vital to a wide spectrum of fields-from air and ground traffic control, to buying and selling goods and services, to TV network programming. Ill-gotten time could even lead to the unimaginable and cause DNS caches to expire, leaving the entire Internet to implode on the root servers.Written by the original developer of the Network Time Protocol (NTP), Computer Network Time Synchronization: The Network Time Protocol on Earth and in Space, Second Edition addresses the technological infrastructure of time dissemination, distrib

  13. An energy efficient and dynamic time synchronization protocol for wireless sensor networks

    Science.gov (United States)

    Zhang, Anran; Bai, Fengshan

    2017-01-01

    Time synchronization is an important support technology of WSN(Wireless Sensor Network), and plays an irreplaceable role in the development of WSN. In view of the disadvantage of the traditional timing sync protocol for sensor networks (TPSN), we present a Physical Timing-sync Protocol (PTPSN) that aims at reducing the energy consumption of the synchronization process and realizes a dynamic Network. The algorithm broadcasts reference message to select some nodes in specific area. The receiver calculate offset of every selected node, and then calculate the average of offset to compensate for clock skew . At the same time ,we add time-filter process to ensure the security of the algorithm for time synchronization. The experiment results show that our algorithm is efficient in both saving energy consumption and dynamic network, and it can effectively resist attacks.

  14. A Self-Stabilizing Hybrid Fault-Tolerant Synchronization Protocol

    Science.gov (United States)

    Malekpour, Mahyar R.

    2015-01-01

    This paper presents a strategy for solving the Byzantine general problem for self-stabilizing a fully connected network from an arbitrary state and in the presence of any number of faults with various severities including any number of arbitrary (Byzantine) faulty nodes. The strategy consists of two parts: first, converting Byzantine faults into symmetric faults, and second, using a proven symmetric-fault tolerant algorithm to solve the general case of the problem. A protocol (algorithm) is also present that tolerates symmetric faults, provided that there are more good nodes than faulty ones. The solution applies to realizable systems, while allowing for differences in the network elements, provided that the number of arbitrary faults is not more than a third of the network size. The only constraint on the behavior of a node is that the interactions with other nodes are restricted to defined links and interfaces. The solution does not rely on assumptions about the initial state of the system and no central clock nor centrally generated signal, pulse, or message is used. Nodes are anonymous, i.e., they do not have unique identities. A mechanical verification of a proposed protocol is also present. A bounded model of the protocol is verified using the Symbolic Model Verifier (SMV). The model checking effort is focused on verifying correctness of the bounded model of the protocol as well as confirming claims of determinism and linear convergence with respect to the self-stabilization period.

  15. A distributed Synchronous reservation multiple access control protocol for mobile Ad hoc networks

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yanling; SUN Xianpu; LI Jiandong

    2007-01-01

    This study proposes a new multiple access control protocol named distributed synchronous reservation multiple access control protocol.in which the hidden and exposed terminal problems are solved,and the quality of service(QoS)requirements for real-time traffic are guaranteed.The protocol is founded on time division multiplex address and a different type of traffic is assigned to difierent priority,according to which a node should compete for and reserve the free slots in a different method.Moreover,there is a reservation acknowledgement process before data transmit in each reserved slot,so that the intruded terminal problem is solved.The throughput and average packets drop probability of this protocol are analyzed and simulated in a fully connected network.the results of which indicate that this protocol is efficient enough to support the real-time traffic.and it is more suitable to MANETs.

  16. A Group Neighborhood Average Clock Synchronization Protocol for Wireless Sensor Networks

    Science.gov (United States)

    Lin, Lin; Ma, Shiwei; Ma, Maode

    2014-01-01

    Clock synchronization is a very important issue for the applications of wireless sensor networks. The sensors need to keep a strict clock so that users can know exactly what happens in the monitoring area at the same time. This paper proposes a novel internal distributed clock synchronization solution using group neighborhood average. Each sensor node collects the offset and skew rate of the neighbors. Group averaging of offset and skew rate value are calculated instead of conventional point-to-point averaging method. The sensor node then returns compensated value back to the neighbors. The propagation delay is considered and compensated. The analytical analysis of offset and skew compensation is presented. Simulation results validate the effectiveness of the protocol and reveal that the protocol allows sensor networks to quickly establish a consensus clock and maintain a small deviation from the consensus clock. PMID:25120163

  17. A Group Neighborhood Average Clock Synchronization Protocol for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Lin Lin

    2014-08-01

    Full Text Available Clock synchronization is a very important issue for the applications of wireless sensor networks. The sensors need to keep a strict clock so that users can know exactly what happens in the monitoring area at the same time. This paper proposes a novel internal distributed clock synchronization solution using group neighborhood average. Each sensor node collects the offset and skew rate of the neighbors. Group averaging of offset and skew rate value are calculated instead of conventional point-to-point averaging method. The sensor node then returns compensated value back to the neighbors. The propagation delay is considered and compensated. The analytical analysis of offset and skew compensation is presented. Simulation results validate the effectiveness of the protocol and reveal that the protocol allows sensor networks to quickly establish a consensus clock and maintain a small deviation from the consensus clock.

  18. Survey is based on Synchronized and Asynchronized Approach of MAC Protocols in WSN

    Directory of Open Access Journals (Sweden)

    Soni Chaurasia

    2010-07-01

    Full Text Available A wireless network is made of spatially distributed autonomous devices. These devices are called sensors. The sensor is used for monitoring physical or environmental conditions. The potential application of wireless sensor network is environmental monitoring, healthcare applications and tactical systems. In this paper focus is on the MAC protocol for WSN. Wireless sensor network is deployed for wide range to send and receive data with the help of medium. Here literature survey of MAC protocol based on the synchronized and asynchronized approach is described which is used to meet different objective like access a medium, statistical channel allocation, spectrum utilization

  19. Inhibition of angiotensin-converting enzyme increases oestradiol production in ewes submitted to oestrous synchronization protocol.

    Science.gov (United States)

    Costa, A s; Junior, A S; Viana, G E N; Muratori, M C S; Reis, A M; Costa, A P R

    2014-10-01

    This study aimed at evaluating the effects of angiotensin-converting enzyme inhibitor (enalapril) and angiotensin II antagonist (valsartan) on the oestradiol and progesterone production in ewes submitted to oestrous synchronization protocol. The animals were weighed and randomly divided into three groups (n = 7). A pre-experiment conducted to verify the effectiveness and toxicity of enalapril (0.5 mg/kg LW) and valsartan (2.2 mg/kg LW) showed that, in the doses used, these drugs were effective in reducing blood pressure without producing toxic effects. In the experiment, all animals were subjected to oestrous synchronization protocol during 12 days. On D10, D11 and D12, animals received saline, enalapril or valsartan (same doses of the pre-experiment), according to the group randomly divided. The hormonal analysis showed an increase in oestradiol on the last day of the protocol (D12) in animals that received enalapril (p progesterone in any of the treatments. It is concluded that valsartan and enalapril are safe and effective subcutaneously for use in sheep and that the angiotensin-converting enzyme (ACE) inhibition with enalapril leads to an increase in oestradiol production near ovulation without changing the concentration of progesterone. This shows that ACE inhibition may be a useful tool in reproductive biotechnologies involving induction and synchronization of oestrus and ovulation in sheep. © 2014 Blackwell Verlag GmbH.

  20. Model Checking a Self-Stabilizing Distributed Clock Synchronization Protocol for Arbitrary Digraphs

    Science.gov (United States)

    Malekpour, Mahyar R.

    2011-01-01

    This report presents the mechanical verification of a self-stabilizing distributed clock synchronization protocol for arbitrary digraphs in the absence of faults. This protocol does not rely on assumptions about the initial state of the system, other than the presence of at least one node, and no central clock or a centrally generated signal, pulse, or message is used. The system under study is an arbitrary, non-partitioned digraph ranging from fully connected to 1-connected networks of nodes while allowing for differences in the network elements. Nodes are anonymous, i.e., they do not have unique identities. There is no theoretical limit on the maximum number of participating nodes. The only constraint on the behavior of the node is that the interactions with other nodes are restricted to defined links and interfaces. This protocol deterministically converges within a time bound that is a linear function of the self-stabilization period.

  1. Synchronization of Estrus in Cattle: A Review

    Directory of Open Access Journals (Sweden)

    R. Islam

    2011-06-01

    Full Text Available Numbers of estrus synchronization programmes are available in cattle based on the use of various hormones like progesterone, prostaglandin F2a and their various combinations with other hormones like estrogen and Gonadotrophin Releasing hormone (GnRH. Selection of appropriate estrus synchronization protocol should be made on the basis of management capabilities and expectations of the farmer. Synchronization of oestrus can be accomplished with the injection of prostaglandin F2a alone, but it needs proper detection of the ovarian status of the cows as prostaglandin F2a is active in only functional corpus luteum in between 8 to 17 days of estrous cycle. Progesterone may reduce fertility up to 14 percent, but short time progesterone exposure (less than 14 days is beneficial. Addition of GnRH in the Progesterone or Prostaglandin based synchronization programme is helpful for more synchrony in estrus as GnRH may be helpful to synchronize the oestrous cycle in delayed pubertal heifers and post partum cows (Post partum anoestrum and further a single, timed artificial insemination is possible with this method. New methods of synchronizing estrus in which the GnRH-PG protocol is preceded by progesterone treatment offer effective synchronization of estrus with high fertility. [Vet. World 2011; 4(3.000: 136-141

  2. Model Checking A Self-Stabilizing Synchronization Protocol for Arbitrary Digraphs

    Science.gov (United States)

    Malekpour, Mahyar R.

    2012-01-01

    This report presents the mechanical verification of a self-stabilizing distributed clock synchronization protocol for arbitrary digraphs in the absence of faults. This protocol does not rely on assumptions about the initial state of the system, other than the presence of at least one node, and no central clock or a centrally generated signal, pulse, or message is used. The system under study is an arbitrary, non-partitioned digraph ranging from fully connected to 1-connected networks of nodes while allowing for differences in the network elements. Nodes are anonymous, i.e., they do not have unique identities. There is no theoretical limit on the maximum number of participating nodes. The only constraint on the behavior of the node is that the interactions with other nodes are restricted to defined links and interfaces. This protocol deterministically converges within a time bound that is a linear function of the self-stabilization period. A bounded model of the protocol is verified using the Symbolic Model Verifier (SMV) for a subset of digraphs. Modeling challenges of the protocol and the system are addressed. The model checking effort is focused on verifying correctness of the bounded model of the protocol as well as confirmation of claims of determinism and linear convergence with respect to the self-stabilization period.

  3. Fault-Tolerant Self-Stabilizing Distributed Clock Synchronization Protocol for Arbitrary Digraphs

    Science.gov (United States)

    Malekpour, Mahyar R. (Inventor)

    2014-01-01

    A self-stabilizing network in the form of an arbitrary, non-partitioned digraph includes K nodes having a synchronizer executing a protocol. K-1 monitors of each node may receive a Sync message transmitted from a directly connected node. When the Sync message is received, the logical clock value for the receiving node is set to between 0 and a communication latency value (gamma) if the clock value is less than a minimum event-response delay (D). A new Sync message is also transmitted to any directly connected nodes if the clock value is greater than or equal to both D and a graph threshold (T(sub S)). When the Sync message is not received the synchronizer increments the clock value if the clock value is less than a resynchronization period (P), and resets the clock value and transmits a new Sync message to all directly connected nodes when the clock value equals or exceeds P.

  4. Control of the estrous cycle to improve fertility for fixed-time artificial insemination in beef cattle: a review.

    Science.gov (United States)

    Lamb, G C; Dahlen, C R; Larson, J E; Marquezini, G; Stevenson, J S

    2010-04-01

    Early estrus-synchronization protocols focused on regressing the corpus luteum (CL) with an injection of PGF(2alpha) followed by detection of estrus or involved the use of exogenous progestins that prevent estrus from occurring. Later, protocols combining the use of PGF(2alpha) and exogenous progestins were developed. Gonadotropin-releasing hormone was utilized to control follicular waves, synchronize ovulation, or to luteinize large dominant follicles. Our research aimed to develop reliable protocols that 1) relied solely on fixed-timed AI (TAI); 2) required a maximum of 3 animal handlings, and 3) were successful in estrous-cycling and noncycling females. In cows, insertion of an intravaginal progesterone insert during the 7-d interval between the initial GnRH and PGF(2alpha) injections enhanced pregnancy rates by 9 to 10%. In a multi-location study, a TAI protocol yielded pregnancy rates similar to a protocol involving detection of estrus plus a fixed-time clean-up AI for females not detected in estrus (54 vs. 58%, respectively, for cows and 53 vs. 57%, respectively, for heifers). Initiation of estrous cycles in noncycling cows is likely the primary manner in which beef producers may improve fertility in response to estrus synchronization and TAI protocols. Treatment of noncycling females with progesterone and GnRH increases the percentage of cycling females and improves fertility to a TAI, but inducing cyclicity with hCG failed to enhance fertility in TAI protocols. Supplementing progesterone after TAI failed to increase pregnancy rates in beef cattle. In contrast, administration of hCG 7 d after TAI induced an accessory CL, increased progesterone, and tended to enhance pregnancy rates. Development of TAI protocols that reduce the hassle factors associated with ovulation synchronization and AI provide cattle producers efficient and effective tools for capturing selective genetic traits of economic consequences. Location variables, however, which may include

  5. Using Ovsynch protocol versus Cosynch protocol in dairy cows

    Directory of Open Access Journals (Sweden)

    Ion Valeriu Caraba

    2013-10-01

    Full Text Available As a research on the reproductive physiology and endocrinology surrounding the estrous cycle in dairy cattle has been compiled, several estrous synchronization programs have been developed for use with dairy cows. These include several programs that facilitate the mass breeding of all animals at a predetermined time (timed-AI rather than the detection of estrus. We studied on 15 dary cows which were synchronized by Ovsynch and Cosynch programs. The estrus response for cows in Ovsynch protocol was of 63%. Pregnancy per insemination at 60 days was of 25%. Estrus response for cow in Cosynch protocol was of 57%. Pregnancy per insemination at 60 days was of 57%. Synchronization of ovulation using Ovsynch protocols can provide an effective way to manage reproduction in lactating dairy cows by eliminating the need for estrus detection. These are really efficient management programs for TAI of dairy cows that are able to reduce both the labour costs and the extra handling to daily estrus detection and AI.

  6. Effect of different estrus synchronization protocols on some reproductive traits in Nubian goats

    International Nuclear Information System (INIS)

    Salim, M. A.; Abu Eissa, H. I.; Abu Nikaila, A.M.; Adam, A. A.

    2009-01-01

    The effect of estrus synchronization protocol on the conception rates and actual kidding percentage together with litter size, birth weight twinning rates, sex of kids and sex ratio in Nubian goats were investigated. Eighteen Nubian goats were divided into three equal groups. The animals in group one were treated with vaginal sponges (VSP) impregnated with 45 mg flurogestone acetate (FGA) for 18 days followed by a single dose of 400 i.u. of pregnant mare serum gonadotrophin (PMSG) upon removal of the VSP. The second group was subjected to a double injects of 7.5 mg prostaglandin (PGF 2 u) given eleven days apart. For the third group, a vasectomies buck was suddenly introduced and kept with goats for 15 days to initiate estrus. Intact bucks were used to detect heat and mate with goats in the the groups. Dose treated with PGF 2 u and those subjected to the buck effect showed significantly higher pregnancy rates (66.6%) than those treated with VSP + PMSG. (33.3%). However, the protocols of synchronization had on effect on the kidding rates, litter size and birth weight. The type of birth comprised both singletons and twins, but none of three groups. (Author)

  7. Estrous of Goats Undergone Superovulation Induction with Anti-inhibin

    Directory of Open Access Journals (Sweden)

    TN Siregar

    2009-01-01

    Full Text Available Estrous performance of goats underlying superovulation induction with anti-inhibin was done using anti-inhibin induction on rabbit. Twenty four goats used in this research that divided four groups namely P0 (control, P1 (immunization at days of 4 cycle, P2 (immunization at days of 9 cycle and P3 (immunization at days of 13 cycle. Immunization on groups was done with injection of 500 μg antibody against inhibin after synchronize before that. Estrous synchronization using injection 0.5 ml cloprostenol (EstronTM, Bioveta two times with interval 10 days. Twenty four hours after immunization, all of goats injection of cloprostenol with same doses. Estrous observation was done after injection of cloprostenol later three times a days. Collection of blood was done at estrous (to analyze of estradiol concentration and at days of 7 cycle (to analyze of progesterone concentration. All f goats after treatment showed estrous behavior as swelling around the vulva and redness, a thin mucous discharge from vulva, social behaviors, and showed mounted. Awal of estrous on P0, P1, P2, and P3 groups were 35.00+7.01; 28.67+4,50; 27.67+4.76; and 29.67+5.86 hours, respectively and revealed no significant difference between control and treatment groups. Duration of estrous on P0, P1, P2, and P3 were 36.67+3.27; 49.33+3.20; 50.33+10.23; and 53.67+11.96 hours, respectively and revealed significant difference (P<0.05 between P2 and P3 with P0 and P1. Length of cycle on P0, P1, P2, and P3 groups were 20.33+1.75; 19.33+0.82; 19.33+2.50; and 20.83+2.56, respectively and revealed no significant difference between control and treatment groups. (Animal Production 11(1: 34-39 (2009 Key Words: anti-inhibin, goats, superovulation, synchronization

  8. Effect of consecutive re-synchronization protocols on pregnancy rate in buffalo (Bubalus bubalis) heifers out of the breeding season.

    Science.gov (United States)

    Neglia, Gianluca; Capuano, Massimo; Balestrieri, Anna; Cimmino, Roberta; Iannaccone, Francesco; Palumbo, Francesco; Presicce, Giorgio A; Campanile, Giuseppe

    2018-06-01

    The combined effect of six consecutive timed artificial inseminations (TAIs) on pregnancy rates, following two different synchronization protocols on buffalo heifers, over a period of seven months typically characterized by low breeding performances, were investigated in this study. A total of 2189 TAIs were performed on 1463 buffalo heifers within a large buffalo farm in the south of Italy. Individual animals were allowed to undergo synchronization protocol (either a slightly modified Ovsynch or Progesterone treatment) and TAI until establishment of pregnancy or else for not more than six consecutive times. Semen of seven proven bulls was used throughout the study, which was carried out from March to September of the same year. Therefore, other than the effect given by consecutive TAIs over time, a monthly and a seasonal effect could also be tested, once the entire period was split into a Low Breeding Season (LBS) from March to June, and a Transition to Breeding Season (TBS) from July to September. From the data recorded in this study and the statistical analysis performed, it can be stated that the two protocols for the synchronization of ovulation were similar in efficiency in determining pregnancies with an overall fertility rate of 89.4% when the comparison was run both on a monthly basis or when months were grouped into two different seasons. In addition, an average of 1.83 AI/pregnancy was reported, slightly higher for the Ovsynch when compared to the Progesterone protocol: 1.91 vs 1.70, respectively. Finally, when considering the number of progressive synchronization treatments implemented over time as covariate, neither Ovsynch nor Progesterone treatment significantly affected pregnancy rates following the first of the six synchronization sessions. However, repeating the synchronization procedure, the progesterone based protocol resulted in significantly higher probability of success in terms of established pregnancies during the second and third re-synchronization

  9. Factors affecting synchronization and conception rate after the Ovsynch protocol in lactating Holstein cows.

    Science.gov (United States)

    Galvão, K N; Santos, J E P

    2010-06-01

    Objectives were to evaluate risk factors affecting ovulatory responses and conception rate to the Ovsynch protocol. Holstein cows, 466, were submitted to the Ovsynch protocol [day 0, GnRH-1; day 7, prostaglandin (PG) F(2alpha); day 9, GnRH-2] and 103 cows were inseminated 12 h after GnRH-2. Information on parity, days in milk at GnRH-1, body condition, milk yield, exposure to heat stress, pre-synchronization with PGF(2alpha) and the use of progesterone insert from GnRH-1 to PGF(2alpha) was collected. Ovaries were scanned to determine responses to treatments. Overall, 54.7%, 10.6%, 2.2%, 81.1%, 9.0%, 91.5% and 36.9% of the cows ovulated to GnRH-1, multiple ovulated to GnRH-1, ovulated before GnRH-2, ovulated to GnRH-2, multiple ovulated to GnRH-2, experienced corpus luteum (CL) regression and conceived, respectively. Ovulation to GnRH-1 was greater in cows without a CL at GnRH-1, cows with follicles >19 mm and cows not pre-synchronized with PGF(2alpha) 14 days before GnRH-1. Multiple ovulations to GnRH-1 increased in cows without CL at GnRH-1 and cows with follicles Conception rate at 42 days after AI increased in cows with body condition score > 2.75 and cows that ovulated to GnRH-2. Strategies that optimize ovulation to GnRH-2, such as increased ovulation to GnRH-1, should improve response to the Ovsynch protocol.

  10. Surveillance and management of estrous cycle in Awassi and Lacaune ewes during out of season

    Directory of Open Access Journals (Sweden)

    Liviu Bogdan

    2016-11-01

    Full Text Available The purpose of this study was to increase fertility in sheep by applying modern biotechnology: induction and synchronization of estrous in non- breeding season. The ewes were divided into 3 equal batches. In all batches intravaginal sponge (Veramix/Intervet containing 60 mg of MPA was left in the vagina for 14 days. Immediately after removal of the sponge an injections of prostaglandin (Dinolytic/Pfizer at the dose of 12.5 mg (2,5ml/animal was administered in batch II. Batch III received two injections: PMSG hormone (Folligon/Intervet at the dose of 500 IU/animal and prostaglandin (Dinolytic/Pfizer at the dose of 12.5 mg (2,5 ml/animal. The research focused on several directions: assessment of estrous manifestation; occurrence of estrous interval after completion of hormonal therapy; duration of estrous; appreciation of gestation after the first and second estrous clinically manifested; percentage of fecundity. From the results obtained it follows that induction and synchronization of estrous in non-breeding season showed economic advantages by shortening the time needed for the installation of gestation, the possibility of lambing distribution, preparation and organization of mating.

  11. Therapy of ovarian inactivity in postpartum Bulgarian Murrah buffaloes by PRID and Ovsynch estrus synchronization protocols

    Institute of Scientific and Technical Information of China (English)

    Stanimir Yotov; Anatoli Atanasov; Yordanka Ilieva

    2012-01-01

    Objective:The aim of the present study was to assess therapeutical effect of modified Ovsynch and PRID estrus synchronization protocols in Bulgarian Murrah buffalo with inactive ovaries during the low-breeding season. Methods:The study was carried out in 46 Bulgarian Murrah buffaloes with small inactive ovaries established by two consecutive transrectal ultrasonographies on Day 40 and 50 postpartum. At the start of the therapy the buffaloes were randomly divided into three groups. Group I (n=18) was treated by PRID-based protocol;Group II (n=18) was treated by Ovsynch based protocol and Group III (control;n=10) was injected intramuscular with saline at the same days as in the first two groups and fertile bull was introduced after that. The animals in the different groups were submitted to ultrasound examination at day of artificial insemination or bull introduction. Ovulation was determined 7 days post insemination by ultrasound. The pregnancy diagnosis was done 30 days after insemination. Mean diameter of the largest follicles at the start of therapy and the day of AI was registered. In the hormonal treated buffaloes estrus clinical sings, ovulation rate and pregnancy rate after AI were determined. In the control group pregnancy rate after spontaneous estrus was established. The mean diameter of the largest follicles determined on Days 40 and 50 after calving was not over 9 mm for all buffaloes. Results:At day of AI the average diameters of the preo-vulatory follicles in PRID and Ovsynch treated buffaloes were significantly (P<0.01) greater than these on Day 0. The cases of a clear uterine mucus discharge during the induced estrus were significant more (P<0.05) for Group I (94.4%) than Group II (66.7%). The pregnancy rate after AI (56.6%and 38.8%) in PRID and Ovsynch program was significant higher (P<0.05) than pregnancy rate after spontaneous estrus (10%) in the control group. Conclusions:the treatment of buffalo ovarian inactivity could start on Day 50

  12. GnRH and prostaglandin-based synchronization protocols as alternatives to progestogen-based treatments in sheep.

    Science.gov (United States)

    Rekik, M; Haile, A; Abebe, A; Muluneh, D; Goshme, S; Ben Salem, I; Hilali, M El-Dine; Lassoued, N; Chanyalew, Y; Rischkowsky, B

    2016-12-01

    The study investigated, for cycling sheep, synchronizing protocols simultaneously to the standard "P" protocol using progestogens priming with intravaginal devices and gonadotropin. In November 2014, 90 adult Menz ewes were assigned to either the "P" protocol, "PGF" treatment where oestrus and ovulation were synchronized using two injections of prostaglandin 11 days apart or a "GnRH" treatment where the ewes had their oestrus and ovulation synchronized with GnRH (day 0)-prostaglandin (day 6)-GnRH (day 9) sequence. The ewes were naturally mated at the induced oestrus and the following 36 days. Plasma progesterone revealed that 92% of the ewes were ovulating before synchronization and all, except one, ovulated in response to the applied treatments. All "P" ewes exhibited oestrus during the 96-hr period after the end of the treatments in comparison with only 79.3% and 73.3% for "PGF" and "GnRH" ewes, respectively (p sheep after the rainy season when most animals are spontaneously cycling. © 2016 Blackwell Verlag GmbH.

  13. Conceptus development and transcriptome at preimplantation stages in lactating dairy cows of distinct genetic groups and estrous cyclic statuses.

    Science.gov (United States)

    Ribeiro, E S; Monteiro, A P A; Bisinotto, R S; Lima, F S; Greco, L F; Ealy, A D; Thatcher, W W; Santos, J E P

    2016-06-01

    The objectives were to compare development and transcriptome of preimplantation conceptuses 15 d after synchronized ovulation and artificial insemination (AI) according to the genetic background of the cow and estrous cyclicity at the initiation of the synchronization program. On d 39±3 postpartum, Holstein cows that were anovular (HA; n=10), Holstein cows that were estrous cyclic (HC; n=25), and Jersey/Holstein crossbred cows that were estrous cyclic (CC; n=25) were randomly selected in a grazing herd and subjected to the Ovsynch protocol. All cows were inseminated on d 49±3 postpartum, which was considered study d 0. Blood was sampled and analyzed for concentrations of progesterone, estradiol, insulin, and insulin-like growth factor 1 (IGF-1) on study d -10, -3, -1, 7, and 15 relative to AI. On study d 15, uteri were flushed and recovered fluid had IFN-τ concentrations measured and subjected to metabolomic analysis. Morphology of the recovered conceptuses was evaluated, and mRNA was extracted and subjected to transcriptome microarray analysis. Compared with HC, CC presented greater concentrations of progesterone and estradiol in plasma, with corpora lutea and preovulatory follicles of similar size. Conceptuses from CC were larger, tended to secrete greater amounts of IFN-τ, and had greater transcript expression of peroxisome proliferator-activated receptor gamma (PPARγ), an important transcription factor that coordinates lipid metabolism and elongation at preimplantation development. In addition, pregnant CC had greater concentrations of anandamide in the uterine flush, which might be important for elongation of the conceptus and early implantation. Conceptuses from HA were also longer and secreted greater amounts of IFN-τ than conceptuses from HC, likely because of the distinct progesterone profiles before and after AI. Nonetheless, anovular cows had reduced concentrations of IGF-1 in plasma, and their conceptuses presented remarkable transcriptomic

  14. A protocol for hit and control synchronous transfer for the front-end electronics at the CBM experiment

    International Nuclear Information System (INIS)

    Kasinski, K.; Szczygiel, R.; Zabolotny, W.; Lehnert, J.; Schmidt, C.J.; Müller, W.F.J.

    2016-01-01

    The Silicon Tracking System, Muon Chamber, Transition Radiation Detector and Time-Of-Flight among others are the detector systems of the Compressed Baryonic Matter (CBM) experiment at the FAIR facility. These detector systems will be built with tens of thousands of front-end ASICs exposed to high radiation doses and difficult environmental and interference conditions. A CERN's GBTx-based solution was chosen for combining data from multiple front-end ASICs into an optical link before further concentration and preprocessing in the common Data Processing Board data hub. This paper presents the protocol design addressing the DAQ system requirements, simplifying the ASIC's back-end design and presents its adaptation for the STS and MUCH detector's conditions. A specific link synchronization technique, hit data bandwidth optimization and time synchronization method for the self-triggered front-end chip are presented.

  15. A protocol for hit and control synchronous transfer for the front-end electronics at the CBM experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kasinski, K., E-mail: kasinski@agh.edu.pl [AGH University of Science and Technology, Department of Measurement and Electronics, Av. Mickiewicza 30, 30-059 Cracow (Poland); Szczygiel, R. [AGH University of Science and Technology, Department of Measurement and Electronics, Av. Mickiewicza 30, 30-059 Cracow (Poland); Zabolotny, W. [Institute of Electronic Systems, Warsaw University of Technology, ul. Nowowiejska 15/19, 00-665 Warsaw (Poland); Lehnert, J.; Schmidt, C.J. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64-291 Darmstadt (Germany); Müller, W.F.J. [FAIR Facility for Antiproton and Ion Research in Europe GmbH, Planckstrasse 1, 64-291 Darmstadt (Germany)

    2016-11-01

    The Silicon Tracking System, Muon Chamber, Transition Radiation Detector and Time-Of-Flight among others are the detector systems of the Compressed Baryonic Matter (CBM) experiment at the FAIR facility. These detector systems will be built with tens of thousands of front-end ASICs exposed to high radiation doses and difficult environmental and interference conditions. A CERN's GBTx-based solution was chosen for combining data from multiple front-end ASICs into an optical link before further concentration and preprocessing in the common Data Processing Board data hub. This paper presents the protocol design addressing the DAQ system requirements, simplifying the ASIC's back-end design and presents its adaptation for the STS and MUCH detector's conditions. A specific link synchronization technique, hit data bandwidth optimization and time synchronization method for the self-triggered front-end chip are presented.

  16. Split-time artificial insemination in beef cattle: I-Using estrous response to determine the optimal time(s) at which to administer GnRH in beef heifers and postpartum cows.

    Science.gov (United States)

    Bishop, B E; Thomas, J M; Abel, J M; Poock, S E; Ellersieck, M R; Smith, M F; Patterson, D J

    2016-09-01

    Two experiments evaluated timing of GnRH administration in beef heifers and cows on the basis of estrous status during split-time artificial insemination (AI) after controlled internal drug release (CIDR) based protocols. In experiment 1, estrus was synchronized for 816 pubertal and prepubertal or peripubertal heifers using the 14-day CIDR-PGF2α (PG) protocol, and in experiment 2, estrus was synchronized for 622 lactating cows using the 7-day CO-Synch + CIDR protocol. For both experiments, estrus detection aids (Estrotect) were applied at PG, with estrus recorded at 66 and 90 hours after PG. Treatments were balanced across locations for heifers using reproductive tract score and weight; whereas for cows, treatments were assigned and balanced to treatment according to age, body condition score, and days postpartum. Timing of AI for heifers and cows was on the basis of estrus expression 66 hours after PG. Females in each treatment that exhibited estrus before 66 hours were inseminated at 66 hours, whereas AI was delayed 24 hours until 90 hours after PG for females failing to exhibit estrus before 66 hours. Females in treatment one received GnRH 66 hours after PG irrespective of estrus expression; however, in treatment 2, GnRH was administered coincident with delayed AI only to females not detected in estrus at 66 hours after PG. Among heifers, there was no effect of treatment on overall estrous response (P = 0.49) or AI pregnancy rate (P = 0.54). Pregnancy rate for heifers inseminated at 66 hours was not influenced by GnRH (P = 0.65), and there were no differences between treatments in estrous response during the 24 hours delay period (P = 0.22). Cows in treatment 2 had a greater (P = 0.04) estrous response during the 24-hour delay period resulting in a greater overall estrous response (P = 0.04), but this did not affect AI pregnancy rate at 90 hours (P = 0.51) or total AI pregnancy rate (P = 0.89). Pregnancy rate resulting from AI for

  17. Study, design and realization of a fault-tolerant and predictable synchronous communication protocol on off-the-shelf components

    International Nuclear Information System (INIS)

    Chabrol, D.

    2006-06-01

    This PhD thesis contributes to the design and realization of safety-critical real-time systems on multiprocessor architectures with distributed memory. They are essential to compute systems that have to ensure complex and critical functions. This PhD thesis deals with communication media management. The communication management conditions strongly the capability of the system to fulfill the timeliness property and the dependability requirements. Our contribution includes: - The design of predictable and fault-tolerant synchronous communication protocol; - The study and the definition of the execution model to have a efficient and safe communications management; - The proposal of a method to generate automatically the communications scheduling. Our approach is based on a communication model that allows the analysis of the feasibility, before execution, of a distributed safe-critical real-time system with timeliness and safety requirements. This leads to the definition of an execution model based on a time-triggered and parallel communication management. A set of linear constraints system is generated automatically to compute the network scheduling and the network load with timeliness fulfillment. Then, the proposed communication interface is based on an advanced version of TDMA protocol which allows to use proprietary components (TTP, FlexRay) as well as standard components (Ethernet). The concepts presented in this thesis lead to the realisation and evaluation of a prototype within the framework of the OASIS project done at the CEA/List. (author)

  18. A Review Of Estrus Synchronization Technology In Cattle | Anyam ...

    African Journals Online (AJOL)

    Manipulation of the oestrous cycle by the use of synchronizing agents to enhance the function of the reproductive organs has proved beneficial to livestock production. Estrus synchronization has enabled a large number of cows to be bred at the same time with subsequent calving at a predictable time. Various estrous cycle ...

  19. Evaluation of response to super-ovulation, estrous synchronization ...

    African Journals Online (AJOL)

    Ethiopian Journal of Agricultural Sciences ... For embryo recipient about 113 females of pure Boran and Holstein Friesian x Boran crossbred cows and heifers ... All data were analyzed using frequency distribution and Chi-square test. Results ...

  20. Mouse estrous cycle identification tool and images.

    Directory of Open Access Journals (Sweden)

    Shannon L Byers

    Full Text Available The efficiency of producing timed pregnant or pseudopregnant mice can be increased by identifying those in proestrus or estrus. Visual observation of the vagina is the quickest method, requires no special equipment, and is best used when only proestrus or estrus stages need to be identified. Strain to strain differences, especially in coat color can make it difficult to determine the stage of the estrous cycle accurately by visual observation. Presented here are a series of images of the vaginal opening at each stage of the estrous cycle for 3 mouse strains of different coat colors: black (C57BL/6J, agouti (CByB6F1/J and albino (BALB/cByJ. When all 4 stages (proestrus, estrus, metestrus, and diestrus need to be identified, vaginal cytology is regarded as the most accurate method. An identification tool is presented to aid the user in determining the stage of estrous when using vaginal cytology. These images and descriptions are an excellent resource for learning how to determine the stage of the estrous cycle by visual observation or vaginal cytology.

  1. Effects of a progesterone-based oestrous synchronization protocol in 51- to 57-day postpartum high-producing dairy cows.

    Science.gov (United States)

    Garcia-Ispierto, I; López-Gatius, F; Bech-Sàbat, G; Yániz, J L; Angulo, E; Maris, C; Floc'h, S; Martino, A

    2010-10-01

    The aim of this study was to investigate the effect of applying a progesterone-based oestrous synchronization protocol at 51-57 days postpartum in high-producing dairy cows. The data analysed were derived from 1345 lactating cows. Cows between 51 and 57 days postpartum were assigned to the groups: control, PRID (receiving a progesterone-releasing intravaginal device for 9 days, and prostaglandin F(2α) 24 h before PRID removal) or GnRH-PRID (the same as the PRID group plus GnRH at PRID insertion). Oestrus was detected by using pedometers and confirmed by examination of the genital tract at AI. Oestrous and conception rates before days 71-77 postpartum, pregnancy loss in early pregnant cows or the cumulative conception rate registered on day 120 postpartum were considered as the dependent variables in four consecutive logistic regression analyses. Based on the odds ratios, the oestrous rate increased by a factor of 1.73 in cows showing oestrus before treatment for each unit increase in the number of previous oestruses; decreased by a factor of 0.44 in the control group with respect to the treatment groups; and by a factor of 0.61 in cows without luteal structures at treatment with respect to cows with corpora lutea. The conception rates of cows inseminated before days 71-77 postpartum remained similar across the groups, whereas the likelihood of pregnancy loss for cows becoming pregnant during this period was 0.11 times lower in the PRID group than in the control. Based on the odds ratio, the likelihood of a higher cumulative conception rate on day 120 postpartum: increased in cows showing oestrus before treatment by a factor of 1.41 for each unit increase in the number of previous oestruses, was reduced 0.56-fold in control cows compared with treated cows, and was also reduced by a factor of 0.98 for each kilogram of milk production increase recorded at treatment. In conclusion, although oestrous synchronization programmes performed in this study did not improve

  2. Cytological Characteristics of Mucose Cell and Vaginal Temperature and pH During Estrous Cycle in Local Sheep

    Directory of Open Access Journals (Sweden)

    Siti Darodjah Rasad

    2017-09-01

    Full Text Available Aim of this study was to examine the characteristics cytology of mucous cell-,temperature- and pH vagina during estrous cycle in local sheep.  31local sheep were synchronized with vaginal sponge consist of 20  mg  progesterone hormone before carried out observations of cytology of cells from the vaginal mucose through vaginal swabs, temperature and pH of the vagina.  Vaginal swabs were collected daily at 7 am for a weeks.Vaginal temperature and pH measurement is carried out twice a day, at 07.00 am and 15.00 pm for a weeks after vaginal swabs. Smears of the swab were then prepared on glass slide and they were stained with Giemsa.  Vaginal epithelial cells; Parabasal, intermediate and superficial cells were counted and their percentages during pro-estrous, estrous and di-estrous were determined. Di-estrous was characterized by the absent of superficial cells in the epithelial vagina. Pro-estrous was characterized by the increasing progressively of intermediate/superficial cells in epithelial vagina, whereas estrous was characterized by the presence of superficial/cornification cells in most epithelial vagina. Based on the dominance of superficial cell, the number of sheep identified as estrous is highest on third day, with 52%.  Observation on vaginal temperature also resulting that the highest temperature values obtained on the third day of 39,08±0.28°C.  It could be effected of the vaginal pH during the observation. Underthe influence ofestrogen, the epithelial vaginalcellssynthesizeand accumulateglycogenin large quantitiesdepositedin the lumen ofvagina. Vaginal bacteriametabolizethe glycogenformlactic acid, which causesvaginal pHis low.The pH conditions prevent from pathogenic microorganisms and fungi. Increased estrogenal so cause cell proliferation through the thickening of the epithelium lining of the vagina so that the cells differentiate.Increasing of glycogenin the superficial cells, and  ceratin cells found in the cytoplasm of

  3. Comparison of estrus synchronization by controlled internal drug release device (CIDR) and adhesive transdermal progestin patch in postpartum beef cows.

    Science.gov (United States)

    Kajaysri, Jatuporn; Chumchoung, Chaiwat; Wutthiwitthayaphong, Supphathat; Suthikrai, Wanvipa; Sangkamanee, Praphai

    2017-09-15

    Estrous synchronization with progesterone based protocols has been essentially used in cattle industry. Although intravaginal devices have been commonly used, this technique may induce vaginitis. This study aimed at examining the efficiency of novel transdermal progestin patch on follicle development and comparing the progestin patch versus CIDR device on estrous synchronization, complication at treated site and pregnancy in beef cattle. In experiment 1, seven beef cows were treated with an adhesive transdermal progestin patch on the ventral surface of the proximal part of the tail for 7 days. The cows were daily examined the follicular development using ultrasonography starting on Day 0 till 3 days after hormone removal. Experiment 2, forty beef cows were divided into two equal groups (20 cows per group). The cows randomly allocated to received either vaginal insertion of CIDR (n = 20) or treated with an adhesive transdermal progestin patch (n = 20). The levels of plasma progesterone during the experiment and the numbers of standing estrous cows were recorded. Timed artificial inseminated (TAI) was performed at 60 h after CIDR or patch termination. Pregnancy rates were determined at 60 days after TAI. Experiment 1 revealed that the novel transdermal progestin patch could efficiently control follicular growth. All the seven treated cows had dominant follicle upon dermal patch removal indicating the effectiveness of the progestin patch. In experiment 2, the percentages of cows exhibited standing estrus were similar between transdermal patch (72.22%) and CIDR (70.00%). The levels of plasma progesterone during CIDR treatment were significantly higher (4.06 ± 1.65 ng/mL on Day 1 and 3.62 ± 1.60 ng/mL on Day 7) compared with transdermal patch (2.60 ± 1.43 ng/mL on Day 1 and 1.81 ± 1.57 ng/mL on Day 7). Three cows treated with CIDR (15%) developed vaginitis while none of cows had physically dermal reaction at adhesive site. Cows synchronized with

  4. Follicular dynamics, interval to ovulation and fertility after AI in short-term progesterone and PGF2α oestrous synchronization protocol in sheep.

    Science.gov (United States)

    Cox, J F; Allende, R; Lara, E; Leiva, A; Díaz, T; Dorado, J; Saravia, F

    2012-12-01

    The study was aimed to assess the influence that short-term progesterone treatments have on follicular dynamics, oestrus and ovulation in sheep. The treatment was tested thereafter in a field trial to assess its fertility after AI with fresh semen. In a first experiment, 12 ewes without CL were grouped to receive a new (n = 6) or used CIDR (n = 6) for 7 days and blood samples were obtained to follow plasma progesterone profiles. In a second experiment, 39 cycling ewes were synchronized by a 7-day P4+PGF2α protocol using a new (n = 20) or a 7-day used CIDR (n = 19). Half of both groups received 400 IU eCG and half remained untreated as controls. Ultrasound ovarian examination and oestrous detection were used to compare follicular dynamics, oestrus and ovulation in both groups. In a third experiment, 288 ewes in 3 farms were synchronized by the short-term P4+PGF2α+eCG protocol and ewes were AI with fresh semen 24 h after oestrous detection. Lambing performance was used to test the fertility of the treatment. In Experiment 1, ewes with new inserts presented higher P4 concentration than ewes with used inserts throughout the sampling period (p 0.10). However, ewes treated with eCG show shorter interval to oestrus (p = 0.004) and tend to have larger mature CL (p = 0.06). In Experiment 3, oestrous presentation and lambing performance after AI with fresh semen was considered normal compared to published results. Results suggest that the oestrous synchronization protocol based on P4+PGF2α allows little control of follicular dynamics without compromising fertility after AI with fresh semen provided that eCG is added at the end of the treatment. © 2012 Blackwell Verlag GmbH.

  5. Evaluation of pregnancy rates of Bos indicus cows subjected to different synchronization ovulation protocols using injectable progesterone or an intravaginal device

    Directory of Open Access Journals (Sweden)

    Jefferson Tadeu Campos

    2016-12-01

    Full Text Available This study evaluated the pregnancy rate in Nelore cows (Bos indicus that were subjected to fixed-time artificial insemination (FTAI using different protocols consisting of injectable progesterone (P4 or an intravaginal device (impregnated with P4. Multiparous cows 72-84 months in age, 30-45 days postpartum, were selected on the basis of the absence of a corpus luteum (CL and follicles < 8 mm after transrectal palpation and ultrasound examinations. On a random day of the estrus cycle (D0, the selected animals (n = 135 were randomly assigned to one of three experimental groups (n = 45 each. Group I (injectable P4/FTAI 36 hours received 250 mg of injectable P4 and 2 mg EB on D0; on D7, they received 500 µg of cloprostenol; on D8, 300 IU of eCG and 1 mg of EB were administered; and finally, FTAI was performed 36 hours after the application of EB. Group II (injectable P4/FTAI 48 hours received the same protocol as Group I, except that the FTAI was performed 48 hours after ovulation induction. The animals of Group III (Control/CIDR received a conventional protocol for FTAI using an intravaginal device (D0: P4 and 2 mg EB; D8: device removal, 500 µg cloprostenol, 300 IU eCG, 1 mg EB; and FTAI performed 48 hours after removal of the device. The results showed that cows synchronized with the conventional protocol for FTAI (Control/CIDR had a higher pregnancy rate (60 %, 27/45 than those synchronized with an injectable P4/FTAI 36 hours (33.33 %; 15/45, P = 0.010. However, the group receiving injectable P4 group/FTAI 48 hours had a similar pregnancy rate (48.9 %; 22/45; P = 0.290 when compared to both the group receiving the conventional protocol and that receiving injectable P4/FTAI 36 hours (P = 0.134. Although the injectable P4 may affect pregnancy rate with the FTAI performed in 36 hours, we found similar pregnancy rates from cows inseminated 48 hours after induction ovulation, considering injectable or intravaginal P4. Therefore, we suggest that

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

    Science.gov (United States)

    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...

  7. Synchronicity from Synchronized Chaos

    Directory of Open Access Journals (Sweden)

    Gregory S. Duane

    2015-03-01

    Full Text Available 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 eventsmysteriously 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”.

  8. Luteal function during the estrous cycle in arginine-treated ewes fed different planes of nutrition.

    Science.gov (United States)

    Bass, Casie S; Redmer, Dale A; Kaminski, Samantha L; Grazul-Bilska, Anna T

    2017-03-01

    Functions of corpus luteum (CL) are influenced by numerous factors including hormones, growth and angiogenic factors, nutritional plane and dietary supplements such as arginine (Arg), a semi-essential amino acid and precursor for proteins, polyamines and nitric oxide (NO). The aim of this study was to determine if Arg supplementation to ewes fed different planes of nutrition influences: (1) progesterone (P4) concentrations in serum and luteal tissue, (2) luteal vascularity, cell proliferation, endothelial NO synthase (eNOS) and receptor (R) soluble guanylate cyclase β protein and mRNA expression and (3) luteal mRNA expression for selected angiogenic factors during the estrous cycle. Ewes (n = 111) were categorized by weight and randomly assigned to one of three nutritional planes: maintenance control (C), overfed (2× C) and underfed (0.6× C) beginning 60 days prior to onset of estrus. After estrus synchronization, ewes from each nutritional plane were assigned randomly to one of two treatments: Arg or saline. Serum and CL were collected at the early, mid and late luteal phases. The results demonstrated that: (1) nutritional plane affected ovulation rates, luteal vascularity, cell proliferation and NOS3, GUCY1B3, vascular endothelial growth factor (VEGF) and VEGFR2 mRNA expression, (2) Arg affected luteal vascularity, cell proliferation and NOS3, GUCY1B3, VEGF and VEGFR2 mRNA expression and (3) luteal vascularity, cell proliferation and the VEGF and NO systems depend on the stage of the estrous cycle. These data indicate that plane of nutrition and/or Arg supplementation can alter vascularization and expression of selected angiogenic factors in luteal tissue during the estrous cycle in sheep. © 2017 Society for Reproduction and Fertility.

  9. Gonadorelin at the outset and/or end of an ovulation synchronization progesterone estradiol benzoate-based protocol in Nellore females

    Directory of Open Access Journals (Sweden)

    Carla Cristian Campos

    2016-02-01

    Full Text Available This study aimed to evaluate the effects of gonadorelin (GnRH, used both at the outset of a timed artificial insemination (TAI protocol to synchronize follicular wave recruitment and at the end to synchronize ovulation, on the conception rate (CR in Nellore cows. The experiment was conducted on two beef cattle farms in the Vale do Araguaia, MT. The body condition score (BCS evaluation and ultrasound examination to determine ovarian status [follicle diameter < 10 mm, ? 10 mm or presence of corpus luteum (CL] were performed at the beginning (Day 0 of the TAI protocol. Multiparous cows (n = 494 were subjected to the following protocol: Day 0 – insertion of intravaginal progesterone device (P4 DIB®, MSD previously used for 8 or 16 days and IM administration of 2.0 mg of estradiol benzoate (EB, Gonadiol®, MSD; Day 8 – P4 device withdrawal, IM injection of 300 IU of equine chorionic gonadotropin (eCG, Folligon®, MSD, 1.0 mg of estradiol cypionate (ECP®, Zoetis and 0.265 mg of Sodium cloprostenol (PGF2?, Ciosin®, MSD; Day 10 – TAI, performed by a single inseminator. Animals were randomly assigned to one of four groups: control (n = 126, GnRH D0 (n = 123, GnRH D10 (n = 123 and GnRH D0 + D10 (n = 122. Animals treated with GnRH received 50 mcg of gonadorelin (GnRH, Cystorelin®, Merial. Pregnancy was diagnosed by ultrasound 39 ± 10 days after TAI. Data were analyzed using the GLIMMIX procedure of SAS program (P < 0.05. The overall CR was 42.71%. Effect of treatment was not detected (P = 0.2482 on CR, which was 36.89% ± 0.19 (47/126 for the control group, 46.08% ± 0.19 (56/123 for GnRH D0, 48.30% ± 0.18 (61/123 for GnRH D10 and 38.48% ± 0.19 (47/122 for GnRH D0 + D10. An effect of farm was detected; the CR was 47.32% ± 0.13 at Farm A and was 38.24% ± 0.13 at Farm B (P = 0.0249. No effects of the interaction between farm and treatment were observed (P = 0.7662, nor of those among ovarian condition and treatment (P = 0.1225 on CR. Cows with

  10. Fertility after implementation of long- and short-term progesterone-based ovulation synchronization protocols for fixed-time artificial insemination in beef heifers.

    Science.gov (United States)

    Kasimanickam, R; Schroeder, S; Hall, J B; Whittier, W D

    2015-04-15

    .4%, and 62.1%, respectively (P < 0.05). In conclusion, heifers synchronized for fixed-time AI with LT and ST protocols resulted in a similar AI pregnancy rate. Approximately, 55% of the herd was pregnant to one insemination in 33 days with the LT protocol compared with just 8 days with the ST protocol. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Validation of a mathematical model of the bovine estrous cycle for cows with different estrous cycle characteristics.

    Science.gov (United States)

    Boer, H M T; Butler, S T; Stötzel, C; Te Pas, M F W; Veerkamp, R F; Woelders, H

    2017-11-01

    A recently developed mechanistic mathematical model of the bovine estrous cycle was parameterized to fit empirical data sets collected during one estrous cycle of 31 individual cows, with the main objective to further validate the model. The a priori criteria for validation were (1) the resulting model can simulate the measured data correctly (i.e. goodness of fit), and (2) this is achieved without needing extreme, probably non-physiological parameter values. We used a least squares optimization procedure to identify parameter configurations for the mathematical model to fit the empirical in vivo measurements of follicle and corpus luteum sizes, and the plasma concentrations of progesterone, estradiol, FSH and LH for each cow. The model was capable of accommodating normal variation in estrous cycle characteristics of individual cows. With the parameter sets estimated for the individual cows, the model behavior changed for 21 cows, with improved fit of the simulated output curves for 18 of these 21 cows. Moreover, the number of follicular waves was predicted correctly for 18 of the 25 two-wave and three-wave cows, without extreme parameter value changes. Estimation of specific parameters confirmed results of previous model simulations indicating that parameters involved in luteolytic signaling are very important for regulation of general estrous cycle characteristics, and are likely responsible for differences in estrous cycle characteristics between cows.

  12. Programmable synchronous communications module

    International Nuclear Information System (INIS)

    Horelick, D.

    1979-10-01

    The functional characteristics of a programmable, synchronous serial communications CAMAC module with buffering in block format are described. Both bit and byte oriented protocols can be handled in full duplex depending on the program implemented. The main elements of the module are a Signetics 2652 Multi-Protocol Communications Controller, a Zilog Z-808 8 bit microprocessor with PROM and RAM, and FIFOs for buffering

  13. Neurosecretory cells of the amygdaloid complex during estrous cycle.

    Science.gov (United States)

    Akhmadeev, A V; Kalimullina, L B

    2005-02-01

    Ultrastructure of neurosecretory cells of the dorsomedial nucleus of the cerebral amygdaloid complex (one of the main zones of sexual dimorphism) was studied in different phases of the estrous cycle. The characteristics of the "light" and "dark" cells change depending on the concentrations of sex steroids during estrus and metestrus.

  14. Study, design and realization of a fault-tolerant and predictable synchronous communication protocol on off-the-shelf components; Etude, conception et mise en oeuvre d'un protocole de communication synchrone tolerant aux fautes et predictible sur des composants reseaux standards

    Energy Technology Data Exchange (ETDEWEB)

    Chabrol, D

    2006-06-15

    This PhD thesis contributes to the design and realization of safety-critical real-time systems on multiprocessor architectures with distributed memory. They are essential to compute systems that have to ensure complex and critical functions. This PhD thesis deals with communication media management. The communication management conditions strongly the capability of the system to fulfill the timeliness property and the dependability requirements. Our contribution includes: - The design of predictable and fault-tolerant synchronous communication protocol; - The study and the definition of the execution model to have a efficient and safe communications management; - The proposal of a method to generate automatically the communications scheduling. Our approach is based on a communication model that allows the analysis of the feasibility, before execution, of a distributed safe-critical real-time system with timeliness and safety requirements. This leads to the definition of an execution model based on a time-triggered and parallel communication management. A set of linear constraints system is generated automatically to compute the network scheduling and the network load with timeliness fulfillment. Then, the proposed communication interface is based on an advanced version of TDMA protocol which allows to use proprietary components (TTP, FlexRay) as well as standard components (Ethernet). The concepts presented in this thesis lead to the realisation and evaluation of a prototype within the framework of the OASIS project done at the CEA/List. (author)

  15. The synchronized trial on expectant mothers with depressive symptoms by omega-3 PUFAs (SYNCHRO): Study protocol for a randomized controlled trial.

    Science.gov (United States)

    Nishi, Daisuke; Su, Kuan-Pin; Usuda, Kentaro; Chiang, Yi-Ju Jill; Guu, Tai-Wei; Hamazaki, Kei; Nakaya, Naoki; Sone, Toshimasa; Sano, Yo; Tachibana, Yoshiyuki; Ito, Hiroe; Isaka, Keiich; Hashimoto, Kenji; Hamazaki, Tomohito; Matsuoka, Yutaka J

    2016-09-15

    Maternal depression can be harmful to both mothers and their children. Omega-3 polyunsaturated fatty acid (PUFA) supplementation has been investigated as an alternative intervention for pregnant women with depressive symptoms because of the supporting evidence from clinical trials in major depression, the safety advantage, and its anti-inflammatory and neuroplasticity effects. This study examines the efficacy of omega-3 PUFA supplementation for pregnant women with depressive symptoms in Taiwan and Japan, to provide evidence available for Asia. The rationale and protocol of this trial are reported here. The Synchronized Trial on Expectant Mothers with Depressive Symptoms by Omega-3 PUFAs (SYNCHRO) is a multicenter, double-blind, parallel group, randomized controlled trial. Participants will be randomized to either the omega-3 PUFAs arm (1,200 mg eicosapentaenoic acid and 600 mg docosahexaenoic acid daily) or placebo arm. Primary outcome is total score on the Hamilton Rating Scale for Depression (HAMD) at 12 weeks after the start of the intervention. We will randomize 56 participants to have 90 % power to detect a 4.7-point difference in mean HAMD scores with omega-3 PUFAs compared with placebo. Because seafood consumption varies across countries and this may have a major effect on the efficacy of omega-3 PUFA supplementation, 56 participants will be recruited at each site in Taiwan and Japan, for a total number of 112 participants. Secondary outcomes include depressive symptoms at 1 month after childbirth, diagnosis of major depressive disorder, changes in omega-3 PUFAs concentrations and levels of biomarkers at baseline and at 12 weeks' follow-up, and standard obstetric outcomes. Data analyses will be by intention to treat. The trial was started in June 2014 and is scheduled to end in February 2018. The trial is expected to provide evidence that can contribute to promoting mental health among mothers and children in Asian populations. Clinicaltrials.gov: NCT

  16. Neural Synchronization and Cryptography

    Science.gov (United States)

    Ruttor, Andreas

    2007-11-01

    Neural networks can synchronize by learning from each other. In the case of discrete weights full synchronization is achieved in a finite number of steps. Additional networks can be trained by using the inputs and outputs generated during this process as examples. Several learning rules for both tasks are presented and analyzed. In the case of Tree Parity Machines synchronization is much faster than learning. Scaling laws for the number of steps needed for full synchronization and successful learning are derived using analytical models. They indicate that the difference between both processes can be controlled by changing the synaptic depth. In the case of bidirectional interaction the synchronization time increases proportional to the square of this parameter, but it grows exponentially, if information is transmitted in one direction only. Because of this effect neural synchronization can be used to construct a cryptographic key-exchange protocol. Here the partners benefit from mutual interaction, so that a passive attacker is usually unable to learn the generated key in time. The success probabilities of different attack methods are determined by numerical simulations and scaling laws are derived from the data. They show that the partners can reach any desired level of security by just increasing the synaptic depth. Then the complexity of a successful attack grows exponentially, but there is only a polynomial increase of the effort needed to generate a key. Further improvements of security are possible by replacing the random inputs with queries generated by the partners.

  17. Estrous behavior in dairy cows: identification of underlying mechanisms and gene functions

    NARCIS (Netherlands)

    Boer, H.M.T.; Veerkamp, R.F.; Beerda, B.; Woelders, H.

    2010-01-01

    Selection in dairy cattle for a higher milk yield has coincided with declined fertility. One of the factors is reduced expression of estrous behavior. Changes in systems that regulate the estrous behavior could be manifested by altered gene expression. This literature review describes the current

  18. Female presence and estrous state influence mouse ultrasonic courtship vocalizations.

    Directory of Open Access Journals (Sweden)

    Jessica L Hanson

    Full Text Available The laboratory mouse is an emerging model for context-dependent vocal signaling and reception. Mouse ultrasonic vocalizations are robustly produced in social contexts. In adults, male vocalization during courtship has become a model of interest for signal-receiver interactions. These vocalizations can be grouped into syllable types that are consistently produced by different subspecies and strains of mice. Vocalizations are unique to individuals, vary across development, and depend on social housing conditions. The behavioral significance of different syllable types, including the contexts in which different vocalizations are made and the responses listeners have to different types of vocalizations, is not well understood. We examined the effect of female presence and estrous state on male vocalizations by exploring the use of syllable types and the parameters of syllables during courtship. We also explored correlations between vocalizations and other behaviors. These experimental manipulations produced four main findings: 1 vocalizations varied among males, 2 the production of USVs and an increase in the use of a specific syllable type were temporally related to mounting behavior, 3 the frequency (kHz, bandwidth, and duration of syllables produced by males were influenced by the estrous phase of female partners, and 4 syllable types changed when females were removed. These findings show that mouse ultrasonic courtship vocalizations are sensitive to changes in female phase and presence, further demonstrating the context-sensitivity of these calls.

  19. Follicular synchronization using transdermal estradiol patch and GnRH antagonists in the luteal phase; does it increase oocyte yield in poor responders to gonadotropin stimulation for in vitro fertilization (IVF)? A comparative study with microdose flare-up protocol.

    Science.gov (United States)

    Ata, Baris; Zeng, Xing; Son, Weon Y; Holzer, Hananel; Tan, Seang L

    2011-11-01

    The aim of this retrospective study was to compare the oocyte yield with the luteal estradiol patch (LPA) - GnRH antagonist and microdose (MD) flare-up protocols in anticipated poor responders. Fifty-seven women who underwent IVF treatment following stimulation with LPA or MD protocols at McGill Reproductive Centre were matched for age and markers of ovarian reserve. Numbers of oocytes collected (6 vs 7), mature oocytes collected (5 vs 5), and oocyte maturation rates (72% vs 74%) were similar. The numbers of good quality embryos available (2 vs 1) and embryos transferred (3 vs 3) were likewise similar. Embryo implantation rate of 16.7% and clinical pregnancy rate of 38.9% achieved in the LPA group were almost 50% higher than the corresponding figures at 10.3% and 22.2% in the MD group; however, the differences were not statistically significant (p > 0.05 for all comparisons). Although the results do not suggest an increased oocyte yield or follicular synchronization with the LPA protocol, the observed trend toward higher embryo implantation and clinical pregnancy rates requires further research.

  20. Development of a synchronous subset of AADL

    DEFF Research Database (Denmark)

    Filali, Mamoun; Lawall, Julia

    2010-01-01

    We study the definition and the mapping of an AADL subset: the so called synchronous subset. We show that the data port protocol used for delayed and immediate connections between periodic threads can be interpreted in a  synchronous way. In this paper, we formalize this interpretation and study ...... the development of its mapping such that the original synchronous semantics is preserved. For that purpose, we use refinements through the Event B method....

  1. Heart rate patterns during courtship and mating in rams and in estrous and nonestrous ewes ().

    Science.gov (United States)

    Orihuela, A; Omaña, J C; Ungerfeld, R

    2016-02-01

    The aim of this study was to compare the heart rate (HR) patterns in rams mated with estrous or nonestrous ewes and in mated estrous and nonestrous ewes () during courtship and mating. For this purpose, HR and behavior were recorded using a radio telemetry recording system and a closed-circuit television system with video recording, respectively. Rams were joined with either an estrous ( = 10) or a nonestrous ( = 10) ewe that was restrained in a stanchion by the neck. Data were continuously recorded until each ram performed 3 ejaculations. Eight days later, the HR of the 10 estrous and 10 nonestrous ewes was recorded during mating. Although the time between entrance into the yard and the first ejaculation was similar across rams, rams that mounted estrous ewes were faster at attaining their second (3min5s ± 17 s vs. 5min28s ± 18 s) and third (7min58s ± 45 s vs. 12 min ± 1min14s) ejaculations (all ewes. In all cases, HR reached maximum values immediately after each ejaculation and the HR pattern was similar across ejaculations (first, second, and third). Although HR was similar between estrous and nonestrous ewes before mating, nonestrous ewes had higher HR ( ewes displayed shorter interejaculation periods but HR did not differ between groups of rams during any ejaculation (first, second, or third), 2) HR for both groups of rams peaked shortly after each ejaculation, and 3) HR increased more in nonestrous than in estrous ewes while mating.

  2. Hamster activity and estrous cycles: control by a single versus multiple circadian oscillator(s).

    OpenAIRE

    Carmichael, M S; Nelson, R J; Zucker, I

    1981-01-01

    Running activity onset and estrous onset were recorded for hamsters exposed to progressively shorter daily light/dark (T) cycles. The period of the estrous cycle was a quadruple multiple of the period of the activity rhythm during entrainment to T cycles of 23.5-21.5 hr. There was no evidence of desynchronization of the activity and estrus rhythms. The very short estrous periods shown during exposure to short T cycles indicate that an intrinsic 96-hr interval for ovarian follicular maturation...

  3. EFFECT OF BYPASS FAT IN PRODUCTIVE AND REPRODUCTIVE PARAMETERS OF FEMALE CATTLE CROSSES INDICA SYNCHRONIZED WITH A CRESTAR® MODIFIED PROTOCOL - GUASDUALITO– VENEZUELA

    Directory of Open Access Journals (Sweden)

    Quintero AD

    2015-12-01

    Full Text Available The objetive of this study was to evaluate the effect of bypass fat in productive and reproductive parameters in bovine females indicates crosses in the Fundación livestock farm; of the parish Guasdualito Venezuela, Apure state, making a modification to Crestar® protocol. The fat by pass was provided by 52 days, to cows with an average of 3 was provided7 years of age, with no health problems and body condition from 2.75 to 3.5 (scale 1-5. The animals were inseminated into two groups and found that the average final body condition in the Gyr and crossbred cows improved; there is a positive correlation strong between the intensity and duration of heat and that the presence of the calves contributes to find animals with jealousy of short duration and low intensity.

  4. Neonatal handling induces anovulatory estrous cycles in rats

    Directory of Open Access Journals (Sweden)

    Gomes C.M.

    1999-01-01

    Full Text Available Since previous work has shown that stimulation early in life decreases sexual receptiveness as measured by the female lordosis quotient, we suggested that neonatal handling could affect the function of the hypothalamus-pituitary-gonadal axis. The effects of neonatal handling on the estrous cycle and ovulation were analyzed in adult rats. Two groups of animals were studied: intact (no manipulation, N = 10 and handled (N = 11. Pups were either handled daily for 1 min during the first 10 days of life or left undisturbed. At the age of 90 days, a vaginal smear was collected daily at 9:00 a.m. and analyzed for 29 days; at 9:00 a.m. on the day of estrus, animals were anesthetized with thiopental (40 mg/kg, ip, the ovaries were removed and the oviduct was dissected and squashed between 2 glass slides. The number of oocytes of both oviductal ampullae was counted under the microscope. The average numbers for each phase of the cycle (diestrus I, diestrus II, proestrus and estrus during the period analyzed were compared between the two groups. There were no significant differences between intact and handled females during any of the phases. However, the number of handled females that showed anovulatory cycles (8 out of 11 was significantly higher than in the intact group (none out of 10. Neonatal stimulation may affect not only the hypothalamus-pituitary-adrenal axis, as previously demonstrated, but also the hypothalamus-pituitary-gonadal axis in female rats.

  5. On Synchronization Primitive Systems.

    Science.gov (United States)

    The report studies the question: what synchronization primitive should be used to handle inter-process communication. A formal model is presented...between these synchronization primitives. Although only four synchronization primitives are compared, the general methods can be used to compare other... synchronization primitives. Moreover, in the definitions of these synchronization primitives, conditional branches are explicitly allowed. In addition

  6. Glycosaminoglycan Distribution in the Rat Uterine Cervix During the Estrous Cycle

    Science.gov (United States)

    Cubas, Jairo Jose Matozinho; Simões, Ricardo Santos; Oliveira-Filho, Ricardo Martins; Simões, Manuel Jesus; Baracat, Edmund C; Soares, José Maria

    2010-01-01

    OBJECTIVE: To analyze the amount of glycosaminoglycans in the uterine cervix during each phase of the rat estrous cycle. DESIGN: Based on vaginal smears, forty female, regularly cycling rats were divided into four groups (n = 10 for each group): GI – proestrous, GII – estrous, GIII – metaestrous and GIV – diestrous. Animals were sacrificed at each phase of the cycle, and the cervix was immediately removed and submitted to biochemical extraction and determination of sulfated glycosaminoglycans and hyaluronic acid. The results were analyzed by ANOVA followed by the Bonferroni post-hoc test. RESULTS: The uterine cervix had the highest amount of total sulfated glycosaminoglycans and dermatan sulfate during the estrous phase (8.90 ± 0.55 mg/g of cetonic extract, phyaluronic acid in the uterine cervix during the estrous cycle. CONCLUSION: Our data suggest that the amount of total sulfated glycosaminoglycans may be influenced by hormonal fluctuations related to the estrous cycle, with dermatan sulfate and heparan sulfate being the glycosaminoglycans most sensitive to hormonal change. PMID:20668628

  7. Synchronization of metronomes

    Science.gov (United States)

    Pantaleone, James

    2002-10-01

    Synchronization is a common phenomenon in physical and biological systems. We examine the synchronization of two (and more) metronomes placed on a freely moving base. The small motion of the base couples the pendulums causing synchronization. The synchronization is generally in-phase, with antiphase synchronization occurring only under special conditions. The metronome system provides a mechanical realization of the popular Kuramoto model for synchronization of biological oscillators, and is excellent for classroom demonstrations and an undergraduate physics lab.

  8. Permutation parity machines for neural synchronization

    International Nuclear Information System (INIS)

    Reyes, O M; Kopitzke, I; Zimmermann, K-H

    2009-01-01

    Synchronization of neural networks has been studied in recent years as an alternative to cryptographic applications such as the realization of symmetric key exchange protocols. This paper presents a first view of the so-called permutation parity machine, an artificial neural network proposed as a binary variant of the tree parity machine. The dynamics of the synchronization process by mutual learning between permutation parity machines is analytically studied and the results are compared with those of tree parity machines. It will turn out that for neural synchronization, permutation parity machines form a viable alternative to tree parity machines

  9. Kappa opioid receptors in rat spinal cord vary across the estrous cycle.

    Science.gov (United States)

    Chang, P C; Aicher, S A; Drake, C T

    2000-04-07

    Kappa opioid receptors (KORs) were immunocytochemically localized in the lumbosacral spinal cord of female rats in different stages of the estrous cycle to examine the influence of hormonal status on receptor density. KOR labeling was primarily in fine processes and a few neuronal cell bodies in the superficial dorsal horn and the dorsolateral funiculus. Quantitative light microscopic densitometry of the superficial dorsal horn revealed that rats in diestrus had significantly lower KOR densities than those in proestrus or estrus. This suggests that female reproductive hormones regulate spinal KOR levels, which may contribute to variations in analgesic effectiveness of KOR agonists across the estrous cycle.

  10. Overview of Cell Synchronization.

    Science.gov (United States)

    Banfalvi, Gaspar

    2017-01-01

    The widespread interest in cell synchronization is maintained by the studies of control mechanism involved in cell cycle regulation. During the synchronization distinct subpopulations of cells are obtained representing different stages of the cell cycle. These subpopulations are then used to study regulatory mechanisms of the cycle at the level of macromolecular biosynthesis (DNA synthesis, gene expression, protein synthesis), protein phosphorylation, development of new drugs, etc. Although several synchronization methods have been described, it is of general interest that scientists get a compilation and an updated view of these synchronization techniques. This introductory chapter summarizes: (1) the basic concepts and principal criteria of cell cycle synchronizations, (2) the most frequently used synchronization methods, such as physical fractionation (flow cytometry, dielectrophoresis, cytofluorometric purification), chemical blockade, (3) synchronization of embryonic cells, (4) synchronization at low temperature, (5) comparison of cell synchrony techniques, (6) synchronization of unicellular organisms, and (7) the effect of synchronization on transfection.

  11. Synchronization in Quantum Key Distribution Systems

    Directory of Open Access Journals (Sweden)

    Anton Pljonkin

    2017-10-01

    Full Text Available In the description of quantum key distribution systems, much attention is paid to the operation of quantum cryptography protocols. The main problem is the insufficient study of the synchronization process of quantum key distribution systems. This paper contains a general description of quantum cryptography principles. A two-line fiber-optic quantum key distribution system with phase coding of photon states in transceiver and coding station synchronization mode was examined. A quantum key distribution system was built on the basis of the scheme with automatic compensation of polarization mode distortions. Single-photon avalanche diodes were used as optical radiation detecting devices. It was estimated how the parameters used in quantum key distribution systems of optical detectors affect the detection of the time frame with attenuated optical pulse in synchronization mode with respect to its probabilistic and time-domain characteristics. A design method was given for the process that detects the time frame that includes an optical pulse during synchronization. This paper describes the main quantum communication channel attack methods by removing a portion of optical emission. This paper describes the developed synchronization algorithm that takes into account the time required to restore the photodetector’s operation state after the photon has been registered during synchronization. The computer simulation results of the developed synchronization algorithm were analyzed. The efficiency of the developed algorithm with respect to synchronization process protection from unauthorized gathering of optical emission is demonstrated herein.

  12. All in good time : dynamics of the bovine estrous cycle investigated with a mathematical model

    NARCIS (Netherlands)

    Boer, H.M.T.

    2012-01-01

    Bovine fertility is subject of extensive research in animal sciences, especially since a decline in dairy cow fertility has been observed during the last decades. One factor is reduced expression of estrous behavior. Fertility is a complex process, regulated by interactions between brain and

  13. Role of estrogens in anterior pituitary gland remodeling during the estrous cycle.

    Science.gov (United States)

    Zárate, S; Zaldivar, V; Jaita, G; Magri, L; Radl, D; Pisera, D; Seilicovich, A

    2010-01-01

    In this review, we analyze the action of estrogens leading to the remodeling of the anterior pituitary gland, especially during the estrous cycle. Proliferation and death of anterior pituitary cells and especially lactotropes is regulated by estrogens, which act by sensitizing these cells to both mitotic and apoptotic stimuli such as TNF-alpha, FasL and dopamine. During the estrous cycle, the changing pattern of gonadal steroids is thought to modulate both cell proliferation and death in the anterior pituitary gland, estrogens being key players in cell turnover. The mechanisms involved in estrogen-modulated cell renewal in the anterior pituitary gland during the estrous cycle could include an increase in the expression of proapoptotic cytokines as well as the increase in the Bax/Bcl-2 ratio at proestrus, when estrogen levels are highest and a peak of apoptosis, in particular of lactotropes, is evident in this gland. Estrogens exert rapid antimitogenic and proapoptotic actions in the anterior pituitary through membrane-associated estrogen receptors, a mechanism that might also be involved in remodeling of this gland during the estrous cycle. Copyright (c) 2010 S. Karger AG, Basel.

  14. The rodent estrous cycle: Characterization of vaginal cytology and its utility in toxicological studies

    Science.gov (United States)

    An evaluation of the estrous cycle in laboratory rodents can be a useful measure of the integrity of the hypothalamic-pituitary-ovarian reproductive axis. It can also serve as a way of insuring that animals exhibiting abnormal cycling patterns are disincluded from a study prior t...

  15. Expression of progesterone receptor membrane component-1 in bovine reproductive system during estrous cycle

    Directory of Open Access Journals (Sweden)

    A.M. Luciano

    2011-09-01

    Full Text Available Several reports suggest the participation of progesterone receptor membrane component 1 (PGRMC1 in progesterone signaling in the reproductive system. This study aimed at investigating the presence and localization of PGRMC1 in bovine ovary, oviduct and uterus, during the follicular and luteal phases of the estrous cycle. In the ovary, PGRMC1 has been detected in surface germinal epithelium, granulosa cells, theca cells and in the germinal vesicle of the oocytesat all stages of folliculogenesis. In the corpus luteum the expression of PGRMC1 was influenced by the stage of the estrous cycle. In the oviducts and in the uterus horns, PGRMC1 was immunolocalized in the luminal epithelium, in the muscle layer cells and in the endothelial cells. In the uterus, PGRMC1 was intensely localized also in the glandular endometrium. However, in the oviducts and in the uterus horns, the localization of PGRMC1 was independent on the stage of the estrous cycle and on whether evaluating the ipsilateral or the contralateral organ. In conclusion, the present immunohistochemical study showed that PGRMC1 is located in various compartments of the bovine female reproductive organs. With the exception of the corpora lutea, PGRMC1 localization showed similar pattern during different stage of the estrous cycle.

  16. Ventromedial hypothalamic glucose sensing and glucose homeostasis vary throughout the estrous cycle.

    Science.gov (United States)

    Santiago, Ammy M; Clegg, Deborah J; Routh, Vanessa H

    2016-12-01

    17β-Estradiol (17βE) regulates glucose homeostasis in part by centrally mediated mechanisms. In female rodents, the influence of the ovarian cycle on hypoglycemia counterregulation and glucose tolerance is unclear. We found previously that in prepubertal females, 17βE modulates glucose sensing in nonadapting glucose-inhibited (GI) and adapting GI (AdGI) neurons within the ventrolateral portion of the ventromedial nucleus (VL-VMN). Nonadapting GI neurons persistently decrease their activity as glucose increases while AdGI neurons transiently respond to a glucose increase. To begin to understand if endogenous fluctuations in estrogen levels across the estrous cycle impact hypothalamic glucose sensing and glucose homeostasis, we assessed whether hypoglycemia counterregulation and glucose tolerance differed across the phases of the estrous cycle. We hypothesized that the response to insulin-induced hypoglycemia (IIH) and/or glucose tolerance would vary throughout the estrous cycle according to changes in 17βE availability. Moreover, that these changes would correlate with estrous-dependent changes in the glucose sensitivity of VL-VMN glucose-sensing neurons (GSNs). These hypotheses were tested in female mice by measuring the response to IIH, glucose tolerance and the glucose sensitivity of VL-VMN GSNs during each phase of the estrous cycle. Furthermore, a physiological brain concentration of 17βE seen during proestrus was acutely applied to brain slices isolated on the day of diestrous and the response to low glucose in VL-VMN GSNs was assayed. The response to IIH was strongest during diestrous. The response of nonadapting GI and AdGI neurons to a glucose decrease from 2.5 to 0.5mM also peaked during diestrous; an effect which was blunted by the addition of 17βE. In contrast, the glucose sensitivity of the subpopulation of GSNs which are excited by glucose (GE) was not affected by estrous phase or exogenous 17βE application. These data suggest that physiological

  17. Ventromedial hypothalamic glucose sensing and glucose homeostasis vary throughout the estrous cycle

    Science.gov (United States)

    Santiago, Ammy M.; Clegg, Deborah J.; Routh, Vanessa H.

    2016-01-01

    Objective 17β-Estradiol (17βE) regulates glucose homeostasis in part by centrally mediated mechanisms. In female rodents, the influence of the ovarian cycle on hypoglycemia counterregulation and glucose tolerance is unclear. We found previously that in prepubertal females, 17βE modulates glucose sensing in nonadapting glucose-inhibited (GI) and adapting GI (AdGI) neurons within the ventrolateral portion of the ventromedial nucleus (VL-VMN). Nonadapting GI neurons persistently decrease their activity as glucose increases while AdGI neurons transiently respond to a glucose increase. To begin to understand if endogenous fluctuations in estrogen levels across the estrous cycle impact hypothalamic glucose sensing and glucose homeostasis, we assessed whether hypoglycemia counterregulation and glucose tolerance differed across the phases of the estrous cycle. We hypothesized that the response to insulin-induced hypoglycemia (IIH) and/or glucose tolerance would vary throughout the estrous cycle according to changes in 17βE availability. Moreover, that these changes would correlate with estrous-dependent changes in the glucose sensitivity of VL-VMN glucose-sensing neurons (GSNs). Methods These hypotheses were tested in female mice by measuring the response to IIH, glucose tolerance and the glucose sensitivity of VL-VMN GSNs during each phase of the estrous cycle. Furthermore, a physiological brain concentration of 17βE seen during proestrus was acutely applied to brain slices isolated on the day of diestrous and the response to low glucose in VL-VMN GSNs was assayed. Results The response to IIH was strongest during diestrous. The response of nonadapting GI and AdGI neurons to a glucose decrease from 2.5 to 0.5mM also peaked during diestrous; an effect which was blunted by the addition of 17βE. In contrast, the glucose sensitivity of the subpopulation of GSNs which are excited by glucose (GE) was not affected by estrous phase or exogenous 17βE application. Conclusion

  18. PROGESTERONE AND ESTRADIOL PROFILES DURING ESTROUS CYCLE AND GESTATION IN DWARF GOATS (CAPRA HIRCUS

    Directory of Open Access Journals (Sweden)

    S. A. KHANUM, M. HUSSAIN AND R. KAUSAR

    2008-01-01

    Full Text Available Serum progesterone and estradiol profiles during estrous cycle, gestation and parturition in four Dwarf goat females (Capra hircus were monitored. Blood sampling was carried out daily during estrous cycle and on alternate days during gestation till parturition. Observations regarding length of estrous cycle, gestation length, litter size and birth weight of kids were recorded. With the initiation of cyclicity, estradiol attained higher levels (7.7 ± 1.7 pg/ml at estrus phase and dropped down to the lower levels within 3 to 4 days post-estrus. Concomitantly, progesterone started to increase from the mean basal value of 0.1 ± 0.03 ng/ml on day-0 to 3.0 ± 0.9 ng/ml on day-6 of estrous cycle and reached the peak value of 7.7 ± 0.6 ng/ml on day-12. From day-15, a decline was observed in progesterone values till the end of the cycle. A second estradiol rise of 14.0 ± 1.2pg/ml was observed on day-18 of the cycle. The mean estrous cycle length was 18.2 ± 2.1 days. During gestation, higher progesterone levels were maintained in the range of 4.3–11.0 ng/ml. Estradiol remained at lower concentrations for 30-50 days of gestation, then gradually increased and reached 270 ± 13.0 pg/ml a few days before parturition. It dropped again to basal values within 1-2 days postpartum. The mean gestation length in Dwarf goats was 144.8 ± 3.9 days and the litter size was 1.8 ± 0.5. It was concluded that Dwarf goat is a prolific breed, having a short gestation length with multiple births being common.

  19. Time Synchronization and Distribution Mechanisms for Space Networks

    Science.gov (United States)

    Woo, Simon S.; Gao, Jay L.; Clare, Loren P.; Mills, David L.

    2011-01-01

    This work discusses research on the problems of synchronizing and distributing time information between spacecraft based on the Network Time Protocol (NTP), where NTP is a standard time synchronization protocol widely used in the terrestrial network. The Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol was designed and developed for synchronizing spacecraft that are in proximity where proximity is less than 100,000 km distant. A particular application is synchronization between a Mars orbiter and rover. Lunar scenarios as well as outer-planet deep space mother-ship-probe missions may also apply. Spacecraft with more accurate time information functions as a time-server, and the other spacecraft functions as a time-client. PITS can be easily integrated and adaptable to the CCSDS Proximity-1 Space Link Protocol with minor modifications. In particular, PITS can take advantage of the timestamping strategy that underlying link layer functionality provides for accurate time offset calculation. The PITS algorithm achieves time synchronization with eight consecutive space network time packet exchanges between two spacecraft. PITS can detect and avoid possible errors from receiving duplicate and out-of-order packets by comparing with the current state variables and timestamps. Further, PITS is able to detect error events and autonomously recover from unexpected events that can possibly occur during the time synchronization and distribution process. This capability achieves an additional level of protocol protection on top of CRC or Error Correction Codes. PITS is a lightweight and efficient protocol, eliminating the needs for explicit frame sequence number and long buffer storage. The PITS protocol is capable of providing time synchronization and distribution services for a more general domain where multiple entities need to achieve time synchronization using a single point-to-point link.

  20. Stages of chaotic synchronization.

    Science.gov (United States)

    Tang, D. Y.; Dykstra, R.; Hamilton, M. W.; Heckenberg, N. R.

    1998-09-01

    In an experimental investigation of the response of a chaotic system to a chaotic driving force, we have observed synchronization of chaos of the response system in the forms of generalized synchronization, phase synchronization, and lag synchronization to the driving signal. In this paper we compare the features of these forms of synchronized chaos and study their relations and physical origins. We found that different forms of chaotic synchronization could be interpreted as different stages of nonlinear interaction between the coupled chaotic systems. (c) 1998 American Institute of Physics.

  1. Highly Accurate Timestamping for Ethernet-Based Clock Synchronization

    OpenAIRE

    Loschmidt, Patrick; Exel, Reinhard; Gaderer, Georg

    2012-01-01

    It is not only for test and measurement of great importance to synchronize clocks of networked devices to timely coordinate data acquisition. In this context the seek for high accuracy in Ethernet-based clock synchronization has been significantly supported by enhancements to the Network Time Protocol (NTP) and the introduction of the Precision Time Protocol (PTP). The latter was even applied to instrumentation and measurement applications through the introduction of LXI....

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

    Science.gov (United States)

    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%, Pbody condition score (BCS) was 3.75 at dry period and 3.0 at the day of Ovsynch. In conclusion, Ovsynch/TAI is an effective tool for the reproductive management of dairy cows. A steady and sufficient conception rate after Ovsynch/TAI could be expected by taking the factors affecting the conception rate into the consideration.

  3. Clock Synchronization for Multihop Wireless Sensor Networks

    Science.gov (United States)

    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…

  4. STUDYING BUSINESS CYCLES SYNCHRONIZATION

    Directory of Open Access Journals (Sweden)

    N. Servetnyk

    2014-06-01

    Full Text Available The paper researches business cycles synchronization. The fluctuations in post-Soviet countries are considered. The study examines different measures of synchronization in groups of countries according to some criteria.

  5. Clock synchronization and dispersion

    International Nuclear Information System (INIS)

    Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo; Wong, Franco N C

    2002-01-01

    We present a method to defeat effects of dispersion of timing signals when synchronizing clocks. It is based on the recently proposed 'conveyor belt synchronization' scheme and on the quantum dispersion cancellation effect

  6. Cell Division Synchronization

    Science.gov (United States)

    The report summarizes the progress in the design and construction of automatic equipment for synchronizing cell division in culture by periodic...Concurrent experiments in hypothermic synchronization of algal cell division are reported.

  7. The vaginal microbiome is stable in prepubertal and sexually mature Ellegaard Göttingen Minipigs throughout an estrous cycle

    DEFF Research Database (Denmark)

    Lorenzen, Emma; Kudirkiene, Egle; Gutman, Nicole

    2015-01-01

    in prepubertal and sexually mature Göttingen Minipigs during an estrous cycle. The dominating phyla in the vaginal microbiota consisted of Firmicutes, Proteobacteria, Actinobacteria, Bacteriodetes and Tenericutes. The most abundant bacterial families were Enterobacteriaceae, unclassified families from...

  8. Synchronization of Multipoint Hoists

    Science.gov (United States)

    A contractor has conceived an electrohydraulic feedback system that will provide position synchronization of four aircraft cargo hoists. To... synchronized hoist system. Test results show that the feedback system concept provides adequate synchronization control; i.e., the platform pitch and roll

  9. Role of Peripheral Alpha2 Adrenergic Receptors in Tonic Pain During Different Stages of Estrous Cycle in Rats

    OpenAIRE

    AR Abyazi Shelmani; M Taherianfard

    2007-01-01

    Introduction: Estrogen and progesterone are supposed to modify pain sensitivity. However, the actual role of each of these steroid hormones in this respect is not well known. Plasma concentrations of these hormones show variation during estrous cycle. The role of alpha2 receptors in tonic pain has been pointed out. The aim of the present study was to investigate the agonist and antagonist effect of alpha2 adrenergic receptors on tonic pain sensitivity during all stages of estrous cycle in fem...

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

    Science.gov (United States)

    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) by number of waves. Growth rate of first dominant follicle was higher (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 estrous cycle, as well as CL development and functionality, was not affected by number of follicular waves.

  11. Presence of the acute phase protein, bikunin, in the endometrium of gilts during estrous cycle and early pregnancy.

    Science.gov (United States)

    Hettinger, A M; Allen, M R; Zhang, B R; Goad, D W; Malayer, J R; Geisert, R D

    2001-08-01

    Noninvasive, epitheliochorial placental attachment in the pig is regulated through endometrial production of protease inhibitors. The objective of the present study was to determine if the light-chain serine protease inhibitor of the inter-alpha-trypsin inhibitor family, bikunin, is produced by the porcine endometrium during the estrous cycle and early pregnancy. Western blot analysis revealed the presence of bikunin in uterine flushings of gilts collected during the luteal phase of the estrous cycle and early pregnancy (Days 12-18). However, bikunin unbound to the inter-alpha-trypsin heavy chains was detected only in endometrial explant culture medium obtained from estrus and pregnant (Days 12, 15, and 18) gilts. Endometrial bikunin gene expression was lowest on Day 10 of the estrous cycle and pregnancy, followed by a 30- to 77-fold increase on Day 15 of the estrous cycle and pregnancy. Bikunin gene expression decreased on Day 18 of the estrous cycle, whereas endometrial bikunin gene expression continued to increase in pregnant gilts. Bikunin mRNA was localized to the uterine glands between Days 15 and 18 of the estrous cycle and pregnancy. In addition to its role as a protease inhibitor, bikunin functions in stabilization of the extracellular matrix, which suggests that bikunin could be involved with facilitating placental attachment to the uterine epithelial surface in the pig.

  12. Synchronization of chaotic systems

    International Nuclear Information System (INIS)

    Pecora, Louis M.; Carroll, Thomas L.

    2015-01-01

    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

  13. Influence of personality, age, sex, and estrous state on chimpanzee problem-solving success

    DEFF Research Database (Denmark)

    Hopper, Lydia M; Price, Sara A; Freeman, Hani D

    2014-01-01

    Despite the importance of individual problem solvers for group- and individual-level fitness, the correlates of individual problem-solving success are still an open topic of investigation. In addition to demographic factors, such as age or sex, certain personality dimensions have also been revealed...... as reliable correlates of problem-solving by animals. Such correlates, however, have been little-studied in chimpanzees. To empirically test the influence of age, sex, estrous state, and different personality factors on chimpanzee problem-solving, we individually tested 36 captive chimpanzees with two novel...... with the luteinizing hormone surge of a female's estrous cycle) and again when it was detumescent. Although we found no correlation between the chimpanzees' success with either puzzle and their age or sex, the chimpanzees' personality ratings did correlate with responses to the novel foraging puzzles. Specifically...

  14. Glycoproteins of mouse vaginal epithelium: differential expression related to estrous cyclicity

    DEFF Research Database (Denmark)

    Horvat, B; Multhaupt, H A; Damjanov, I

    1993-01-01

    We used lectin overlay blotting and SDS-PAGE to analyze the estrous cycle-specific expression of mouse vaginal epithelial glycoproteins. Seven lectins chosen for their differential carbohydrate-binding specificity revealed 15 glycoproteins that showed cycle-related expression. Each lectin had...... in proestrus, coincident with the transformation of two superficial layers of vaginal squamous epithelium into mucinous cuboidal cells. Electron microscopic lectin histochemistry revealed the glycoproteins in the mucinous granules of surface cuboidal cells and in the lumen of the vagina. Our results illustrate...... the complexity of glycoconjugate synthesis in mouse vagina and reveal the distinct cycle-specific patterns of individual glycoprotein expression. These cyclic glycoproteins could serve as vaginal biochemical markers for the specific phases of the estrous cycle....

  15. Spontaneous group synchronization of movements and respiratory rhythms.

    Directory of Open Access Journals (Sweden)

    Erwan Codrons

    Full Text Available We tested whether pre-assigned arm movements performed in a group setting spontaneously synchronized and whether synchronization extended to heart and respiratory rhythms. We monitored arm movements, respiration and electrocardiogram at rest and during spontaneous, music and metronome-associated arm-swinging. No directions were given on whether or how the arm swinging were to be synchronized between participants or with the external cues. Synchronization within 3 groups of 10 participants studied collectively was compared with pseudo-synchronization of 3 groups of 10 participants that underwent an identical protocol but in an individual setting. Motor synchronization was found to be higher in the collective groups than in the individuals for the metronome-associated condition. On a repetition of the protocol on the following day, motor synchronization in the collective groups extended to the spontaneous, un-cued condition. Breathing was also more synchronized in the collective groups than in the individuals, particularly at rest and in the music-associated condition. Group synchronization occurs without explicit instructions, and involves both movements and respiratory control rhythms.

  16. Effects of breed and ram exposure on Spring estrous behavior and Summer fertility in domestic ewes

    OpenAIRE

    Nugent, Russell A., III

    1987-01-01

    The present studies were conducted to check the effects of acute ram introduction into a flock of anestrus ewes in Virginia. Ewes were bled via jugular venipuncture twice weekly and serum samples were radioimmunoassayed for progesterone (P4) content as an indicator of estrous activity. All rams were fitted with crayon equipped marking harnesses for use as an indicator of mating behavior in ewes. The first study tested the effects of introduction of vasectomized rams in...

  17. Effects of the estrous cycle and ovarian hormones on behavioral indices of anxiety in female rats.

    Science.gov (United States)

    Mora, S; Dussaubat, N; Díaz-Véliz, G

    1996-10-01

    The influence of the estrous cycle and the effects of exogenous administration of estradiol and progesterone on level of anxiety were studied in intact and ovariectomized rats. Intact Sprague-Dawley female rats were classified according to the stages of estrous cycle. Another group of rats was ovariectomized bilaterally and, 14 days after surgery, they received estradiol benzoate (10 micrograms/kg, s.c.) and/or progesterone (25 mg/kg, s.c.) or corn oil (1 ml/kg). The behavioral tests began 3 h after estradiol or 6 h after progesterone and consisted of: (1) exploration of an elevated plus-maze; and (2) retention of a passive avoidance response. Open-arm exploration of the plus-maze varied according to light intensity and the stages of the estrous cycle. There was a slight increase in open-arm exploration by rats in metestrus, under high light intensity. Low light intensity increased the exploration of the open arms by rats in proestrus and estrus, compared to the other phases of the cycle. Retention of the passive avoidance response was inhibited during proestrus and estrus. Progesterone increased open-arm exploration of the plus-maze under high light conditions, whereas estradiol antagonized this effect. Retention of passive avoidance was inhibited after estradiol or progesterone injection. These results suggest that the behavioral indices of anxiety can vary across the estrous cycle, that low light intensities have anxiolytic-like effects, and that the sensitivity to this effect is higher during proestrus and estrus. This could be explained through modulatory effects of ovarian hormones upon behavioral indices of anxiety.

  18. Early postnatal treatment with clomipramine induces female sexual behavior and estrous cycle impairment.

    Science.gov (United States)

    Molina-Jiménez, Tania; Limón-Morales, Ofelia; Bonilla-Jaime, Herlinda

    2018-03-01

    Administration of clomipramine (CMI), a tricyclic antidepressant, in early stages of development in rats, is considered an animal model for the study of depression. This pharmacological manipulation has induced behavioral and physiological alterations, i.e., less pleasure-seeking behaviors, despair, hyperactivity, cognitive dysfunction, alterations in neurotransmitter systems and in HPA axis. These abnormalities in adult male rats are similar to the symptoms observed in major depressive disorders. One of the main pleasure-seeking behaviors affected in male rats treated with CMI is sexual behavior. However, to date, no effects of early postnatal CMI treatment have been reported on female reproductive cyclicity and sexual behavior. Therefore, we explored CMI administration in early life (8-21 PN) on the estrous cycle and sexual behavior of adult female rats. Compared to the rats in the early postnatal saline treatment (CTRL group), the CMI rats had fewer estrous cycles, fewer days in the estrous stage, and longer cycles during a 20-day period of vaginal cytology analysis. On the behavioral test, the CMI rats displayed fewer proceptive behaviors (hopping, darting) and had lower lordosis quotients. Also, they usually failed to display lordosis and only rarely manifested marginal or normal lordosis. In contrast, the CTRL rats tended to display normal lordosis. These results suggest that early postnatal CMI treatment caused long-term disruptions of the estrous cycle and female sexual behavior, perhaps by alteration in the hypothalamic-pituitary-gonadal (HPG) axes and in neuronal circuits involved in the regulation of the performance and motivational of sexual behavior as the noradrenergic and serotonergic systems. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Hormone-dependence of sarin lethality in rats: Sex differences and stage of the estrous cycle

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Carl D., E-mail: carl.d.smith179.mil@mail.mil; Wright, Linnzi K.M.; Garcia, Gregory E.; Lee, Robyn B.; Lumley, Lucille A.

    2015-09-15

    Chemical warfare nerve agents (CWNAs) are highly toxic compounds that cause a cascade of symptoms and death, if exposed casualties are left untreated. Numerous rodent models have investigated the toxicity and mechanisms of toxicity of CWNAs, but most are limited to male subjects. Given the profound physiological effects of circulating gonadal hormones in female rodents, it is possible that the daily cyclical fluctuations of these hormones affect females' sensitivity to the lethal effects of CWNAs, and previous reports that included female subjects did not control for the stage of the hormonal cycle. The aim of the current study was to determine the 24-hour median lethal dose (LD{sub 50}) of the CWNA sarin in male, ovariectomized (OVEX) female, and female rats during different stages of the estrous cycle (diestrus, proestrus, and estrus). Additionally, baseline activity levels of plasma acetylcholinesterase, butyrylcholinesterase, and carboxylesterase were measured to determine differences among the groups. Results indicated that females in proestrus had a significantly higher LD{sub 50} of sarin compared to OVEX and estrous females. Although some sex differences were observed in the activity levels of plasma esterases, they were not consistent and likely not large enough to significantly affect the LD{sub 50}s. These results suggest that hormonal cyclicity can influence the outcome of CWNA-related studies using female rodents, and that this variability can be minimized by controlling for the stage of the cycle. Additional research is necessary to determine the precise mechanism of the observed differences because it is unlikely to be solely explained by plasma esterase activity. - Highlights: • The LD{sub 50} of sarin was determined in female rats throughout the stages of the estrous cycle. • Females in proestrus had a significantly higher LD{sub 50} compared to estrous or ovariectomized females. • No sex differences were observed between male and female

  20. Effects of Simulated Hypogravity and Diet on Estrous Cycling in Rats

    Science.gov (United States)

    Tou, Janet C.; Grindeland, Richard E.; Baer, Lisa A.; Wade, Charles E.

    2003-01-01

    Environmental factors can disrupt ovulatory cycles. The study objective was to determine the effect of diet and simulated hypogravity on rat estrous cycles. Age 50 d Sprague-Dawley rats were randomly assigned to he fed either a purified or chow diet. Only normal cycling rats were used. Experimental rats (n=9-10/group) were kept as ambulatory controls (AC) or subjected to 40 d simulated hypogravity using a disuse atrophy hindlimb suspension (HLS) model. There was no effect on estrous cycles of AC fed either diet. At day 18, HLS rats fed either diet, had lengthened estrous cycles due to prolonged diestrus. HLS rats fed purified diet also had reduced time in estrus. Plasma estradiol was reduced in HLS rats fed purified diet but there was no effect on progesterone. This may have occurred because blood was collected from rats in estrus. Urinary progesterone collected during initial HLS was elevated in rats fed purified diet. In AC, corticosterone was elevated in chow vs purified diet fed rats. Differences were particularly striking following the application of a stressor with HLS/chow-fed rats displaying an enhanced stress response. Results emphasize the importance of diet selection when measuring endocrine-sensitive endpoints. HLS is a useful model for investigating the effects of environment on reproduction and providing insight about the impact extreme environment such as spaceflight on female reproductive health.

  1. Estrous cycle and food availability affect feeding induced by amygdala 5-HT receptor blockade.

    Science.gov (United States)

    Parker, Graham C; Bishop, Christopher; Coscina, Donald V

    2002-04-01

    We have recently reported that bilateral infusions of the 5-HT receptor antagonist metergoline (MET) into the posterior basolateral amygdala (pBLA) elicit feeding in female rats tested at mid-light cycle. The present study was performed to determine whether (1) testing at two different phases of the estrous cycle, and/or (2) the palatability of the food might modify this effect. Subjects were 18 adult females with bilateral pBLA cannulae. Following familiarization with Froot Loops cereal, a within-subjects design tested all animals for 1- and 2-h food intake under 2 Drug (0.3 nmol MET vs. Vehicle), 2 Estrous Cycle (diestrus vs. estrus) and 2 Food (lab chow vs. Froot Loops) conditions. Rats weighed more at diestrus than at proestrus (Pestrus (Pestrus. A three-way interaction (Pestrus than in diestrus to lab chow but not Froot Loops. These data suggest pBLA MET differentially affects feeding over the estrous cycle depending on the palatability of food available.

  2. Evaluation of salivary electrolytes during estrous cycle in Murrah buffaloes with reference to estrus detection

    Directory of Open Access Journals (Sweden)

    Indu Devi

    2016-10-01

    Full Text Available Aim: Timely estrus detection is one of the critical factors for increasing reproductive efficiency in buffaloes. In recent decades, saliva has become a more popular as a noninvasive source for determining physiological status of animals by various biochemical electrolytes. This study was designed to assess and correlate changes in different salivary minerals concentration (calcium, inorganic phosphorus, magnesium, sodium, potassium, and chloride during different stages of the estrous cycle in Murrah buffaloes. Materials and Methods: The saliva samples were collected during the different phases of the estrous cycle from 20 Murrah buffaloes in early morning hours and were assayed using respective minerals assay kits. Results: The concentrations of calcium (8.76±0.08-12.11±0.11 mg/dl, inorganic phosphorus (6.56±0.13-14.72±4.50 mg/dl, magnesium (2.27±0.14-5.79±0.15 mg/dl, sodium (139.47±0.31-159.62±1.22 mmol/L, potassium (12.40±0.22-26.85±1.22 mmol/L, and chloride (109.28±0.41-137.07±0.68 mmol/L varied during the different phases of estrous cycle. The concentration of calcium, inorganic phosphorus, magnesium, sodium, potassium, and chloride in saliva were significantly (p<0.01 higher during estrus phase compared to other phases of the estrous cycle. All these minerals were positively and significantly (p<0.0001 related to estrogen concentration while salivary concentrations of calcium, magnesium, sodium, and chloride showed a significant (p<0.0001 negative correlation with progesterone level in blood plasma. Conclusion: These preliminary findings indicate that there are definite variations in salivary mineral and electrolyte concentrations during different phases of the estrous cycle. These results may be used as an aid for estrus detection/ confirmation in buffaloes although validation of the results using a large number of animals is required.

  3. Synchronization of Concurrent Processes

    Science.gov (United States)

    1975-07-01

    Pettersen Stanford Ur.iversity Artificial Intelligence Laboratory ABSTRACT Th oaoer gives an overview of commonly used synchronization primitives and...wr.ters . ut.l.z.ng the DroDo4d synchronization primitive . The solution is simpler and shorter than other known S’ms The first sections of the paper...un reicr»» side il nrcttaary and Identity by block number) Scheduling, process scheduling, synchronization , mutual exclusion, semaphores , critical

  4. Adaptive Backoff Synchronization Techniques

    Science.gov (United States)

    1989-07-01

    Percentage of synchronization and non- synchronisation references that cause invalidations in directory schemes with 2, 3, 4, 5, and 64 pointers...processors to arrive. The slight relative increase of synchronisation overhead in all cases when going from two to five pointers is because synchronization ...MASSACHUSETTS INSTITUTE OF TECHNOLOGY VLSI PUBLICATIONS q~JU VLSI Memo No. 89-547 It July 1989 Adaptive Backoff Synchronization Techniques Anant

  5. Synchronization on effective networks

    International Nuclear Information System (INIS)

    Zhou Tao; Zhao Ming; Zhou Changsong

    2010-01-01

    The study of network synchronization has attracted increasing attentionrecently. In this paper, we strictly define a class of networks, namely effective networks, which are synchronizable and orientable networks. We can prove that all the effective networks with the same size have the same spectra, and are of the best synchronizability according to the master stability analysis. However, it is found that the synchronization time for different effective networks can be quite different. Further analysis shows that the key ingredient affecting the synchronization time is the maximal depth of an effective network: the larger depth results in a longer synchronization time. The secondary factor is the number of links. The increasing number of links connecting nodes in the same layer (horizontal links) will lead to longer synchronization time, whereas the increasing number of links connecting nodes in neighboring layers (vertical links) will accelerate the synchronization. Our analysis of the relationship between the structure and synchronization properties of the original and effective networks shows that the purely directed effective network can provide an approximation of the original weighted network with normalized input strength. Our findings provide insights into the roles of depth, horizontal and vertical links in the synchronizing process, and suggest that the spectral analysis is helpful yet insufficient for the comprehensive understanding of network synchronization.

  6. Synchronization on effective networks

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Tao [Web Sciences Center, University of Electronic Science and Technology of China, Chengdu 610054 (China); Zhao Ming [Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China); Zhou Changsong, E-mail: cszhou@hkbu.edu.h [Department of Physics, Hong Kong Baptist University, Kowloon Tong (Hong Kong)

    2010-04-15

    The study of network synchronization has attracted increasing attentionrecently. In this paper, we strictly define a class of networks, namely effective networks, which are synchronizable and orientable networks. We can prove that all the effective networks with the same size have the same spectra, and are of the best synchronizability according to the master stability analysis. However, it is found that the synchronization time for different effective networks can be quite different. Further analysis shows that the key ingredient affecting the synchronization time is the maximal depth of an effective network: the larger depth results in a longer synchronization time. The secondary factor is the number of links. The increasing number of links connecting nodes in the same layer (horizontal links) will lead to longer synchronization time, whereas the increasing number of links connecting nodes in neighboring layers (vertical links) will accelerate the synchronization. Our analysis of the relationship between the structure and synchronization properties of the original and effective networks shows that the purely directed effective network can provide an approximation of the original weighted network with normalized input strength. Our findings provide insights into the roles of depth, horizontal and vertical links in the synchronizing process, and suggest that the spectral analysis is helpful yet insufficient for the comprehensive understanding of network synchronization.

  7. OMEGA SYSTEM SYNCHRONIZATION.

    Science.gov (United States)

    TIME SIGNALS, * SYNCHRONIZATION (ELECTRONICS)), NETWORKS, FREQUENCY, STANDARDS, RADIO SIGNALS, ERRORS, VERY LOW FREQUENCY, PROPAGATION, ACCURACY, ATOMIC CLOCKS, CESIUM, RADIO STATIONS, NAVAL SHORE FACILITIES

  8. Role of Peripheral Alpha2 Adrenergic Receptors in Tonic Pain During Different Stages of Estrous Cycle in Rats

    Directory of Open Access Journals (Sweden)

    AR Abyazi Shelmani

    2007-12-01

    Full Text Available Introduction: Estrogen and progesterone are supposed to modify pain sensitivity. However, the actual role of each of these steroid hormones in this respect is not well known. Plasma concentrations of these hormones show variation during estrous cycle. The role of alpha2 receptors in tonic pain has been pointed out. The aim of the present study was to investigate the agonist and antagonist effect of alpha2 adrenergic receptors on tonic pain sensitivity during all stages of estrous cycle in female rats. Methods: Xylasine as alpha2 agonist and yohimbin as alpha2 antagonist were used via intraperitoneal route (IP. Adult rats weighing 180-200 grams were used. Animals were maintained on 12h reverse light/dark cycle for 7 days prior to the experiment. Water and food was available ad libitum. Formalin test was performed by subcutaneous injection of 50 l formalin (2.5% solution into the hind paw. Formalin test was performed in all stages of estrous cycle for 60 minutes. Animals were divided into four groups; 1- control group (intact animal, 2- Sham group (animals received 0.2 ml normal saline by IP route, 3- Agonist groups (animals received 0.2 ml xylasine 1, 3 mg/kg body weight by IP route and 4- Antagonist group (animals received 0.2 ml yohimbine 1, 3 mg/kg body weight by IP route. Data were statistically analyzed using 2 way ANOVA test followed by Tukey's test as post-hoc test. P<0.05 was considered significant. Results: Results showed that xylasine significantly (p<0.05 decreases pain sensitivity in all stages of estrous cycle. Analgesic effect of xylasine was maximum in estrus stage of estrous cycle and minimum in metestrus stage of estrous cycle. Yohimbine significantly (p<0.05 increases pain sensitivity in all stages of estrous cycle. Hyperalgesic effect of yohimbine was maximum in metestrus stage of estrous cycle and minimum in estrus stage of estrous cycle. Conclusion: These results indicate that alpha2 adrenergic system and endogenous

  9. LEVEL OF ESTRADIOL 17-β SERUM AND OVARIAN FOLLICULARE DYNAMICS IN SHORT ESTROUS CYCLE OF BALI CATTLE

    Directory of Open Access Journals (Sweden)

    C.M Airin

    2014-09-01

    Full Text Available The aims of the research were to confirm the short estrous cycles and determine the blood level ofestradiol 17-β and ovarian follicukar dynamics in these cases. The research was conducted using sevenBali cattle, approximately 2 years of age, kept in healthy condition with normal estrous cycles.Observation of estrus symptoms was performed daily. Ovarian follicles was examined and measuredusing ultrasonography started at the estrus day. Blood samples were collected from jugular vein, bloodsample collection and ultrasonographical examination of the ovaries were performed daily in the sametime. Serum level of estradiol 17-β was performed using EIA. The short cycle estrus were observed in 4Bali cattle (n=7 among natural estrous cycle. They have only one wave ovarian follicular developmentwhereas the maximal size of ovarian follicles ovulation likes the normal cycle The duration of shortestrous cycle was 7-10 days with normal usual estrus behavior. The peak of blood serum level was107.77 ± 55.94 pg/ml when the diameter dominant follicle of short estrous cycle was reached 10.5 ±0.38 mm. It can be concluded that the short estrous cycles may occur in Bali cattle after puberty amongnormal cycles.

  10. Synchronicity and Leadership

    NARCIS (Netherlands)

    Merry, Philip

    2017-01-01

    LAY SUMMARY SYNCHRONICITY AND LEADERSHIP TILBURG PHD DISSERTATION, PHILIP MERRY World’s First PhD to Research Synchronicity And Leadership Using Grounded Theory OUT OF THE BLUE COINCIDENCES: research topic Most people have had the experience of thinking of someone and then, almost magically have

  11. Synchronization of hyperchaotic oscillators

    DEFF Research Database (Denmark)

    Tamasevicius, A.; Cenys, A.; Mykolaitis, G.

    1997-01-01

    Synchronization of chaotic oscillators is believed to have promising applications in secure communications. Hyperchaotic systems with multiple positive Lyapunov exponents (LEs) have an advantage over common chaotic systems with only one positive LE. Three different types of hyperchaotic electronic...... oscillators are investigated demonstrating synchronization by means of only one properly selected variable....

  12. RUN LENGTH SYNCHRONIZATION TECHNIQUES

    Science.gov (United States)

    An important aspect of digital communications is the problem of determining efficient methods for acquiring block synchronization . In this paper we...utilizes an N-digit sync sequence as prefix to the data blocks. The results of this study show that this technique is a practical method for acquiring block synchronization .

  13. Fear extinction in an obsessive-compulsive disorder animal model: Influence of sex and estrous cycle.

    Science.gov (United States)

    Reimer, Adriano Edgar; de Oliveira, Amanda Ribeiro; Diniz, Juliana Belo; Hoexter, Marcelo Queiroz; Miguel, Euripedes Constantino; Milad, Mohammed Ragib; Brandão, Marcus Lira

    2018-03-15

    Obsessive-compulsive disorder (OCD) is a neuropsychiatric condition that affects men and women equally, but with a sexually dimorphic pattern of development. Reproductive cycle events can influence symptom severity of OCD in females, indicating that ovarian hormones or their interaction with distinct neurotransmitter systems may play a role in OCD pathophysiology. Clinical studies and animal models have confirmed the importance of the serotonergic (5-HT) system in the neurobiology and treatment of OCD. Accordingly, the non-selective 5-HT2c agonist, meta-chlorophenylpiperazine (mCPP), exacerbates symptoms in untreated OCD patients. In rodents, it evokes repetitive behaviors that engage brain areas that are homologous with those found to be dysfunctional in OCD patients. These regions, including the medial prefrontal and anterior cingulate cortices, are also involved in fear inhibition, which is impaired in OCD. Here, we treated rats with mCPP (0.5 and 3.0 mg/kg) to evaluate its influence on self-grooming behavior and assess potential fear extinction retention deficits, taking into account sex differences and females' estrous cycle. We found that mCPP exacerbated grooming in male and female rats, irrespective of the estrous cycle phase. Fear extinction retention, however, was impaired only in females. Moreover, females undergoing fear extinction training during the metestrus/diestrus phases of the estrous cycle were more sensitive to the impairments induced by mCPP. Our results indicate that mCPP can induce OCD-like symptoms, exacerbating self-grooming and impairing fear extinction. It suggests that changes in 5-HT signaling through 5-HT2c receptors may have an important role in the OCD pathophysiology and that the influence of gonadal hormones in OCD should be further investigated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Effects of adrenalectomy and constant light on the rat estrous cycle.

    Science.gov (United States)

    Hoffmann, J C

    1978-01-01

    Adult female ARS/Sprague-Dawley rats were allowed to acclimatize to a a lighting schedule of 12L:12D (LD) for 5 weeks. At that time, half the animals were adrenalectomized, and all rats remained in LD for an additional 4 to 5 weeks. Subsequently, half of the control and half of the adrenalectomized rats were exposed to constant light (LL) for an additional 8 weeks, at which time all animals were sacificed. Operated rats with regenerated adrenal tissue, determined either by macroscopic examination or serum corticosterone assay (about 50% of the rats), were excluded from all data calculations. Acute disturbances of estrous cycle length were minor. The long-term effects revealed a significant increase in 5-day cycles among the adrenalectomized rats, although the majority of cycles recorded (80%) were still 4 days in length. None of the rats in LD showed spontaneous persistent estrus. Adrenalectomy did not affect the number of ova shed. When placed in LL, the adrenalectomized rats continued to cycle longer than the unoperated controls, but all rats showed persistent estrus (5 or more consecutive days of vaginal cornification) within 7--8 weeks. Adrenalectomized rats had significantly higher body weights than controls. Relative uterine weight was decreased in these animals in both lighting regimens but only reached statistical significance in LD. Ovarian weight, by contrast, was significantly increased among adrenalectomized rats in LD but was identical in both groups in LL. Adrenal weight of intact rats was not altered by LL. Since estrous cycles can continue for at least 6 months in the absence of the adrenal gland, the persistent estrus that occurs in LL is not merely due to the loss of a diurnal rhythm of corticosteroids. Indeed, when adrenalectomized rats are placed in LL, they continue to show estrous cycles longer than do intact rats. Adrenalectomy does appear to increase the length of the cycle in some animals, and the hormonal basis for this warrants further

  15. Endoscopic monitoring the estrous phase of Arabian mares with assaying its biopsy

    Directory of Open Access Journals (Sweden)

    Mohamed Fathi

    2017-01-01

    Full Text Available Objective: To evaluate the changes occur in the vagina, cervix and endometrium during the pre- ovulatory period in Arabian mares by using endoscope as a diagnostic tool as well as the availability of taking an endoscopic biopsy during this stage.Methods: Ten cyclic and healthy arabian mares were subjected to ultrasound scanning of their ovaries to estimate the diameter of the preovulatory follicles, collection of blood samples for estimating the hormonal levels (Estradiol-17 β and progestrone for confirming the estrous phase, endoscopic monitoring their vagina, cervix and endometrium, the availability of taking biopsical samples and histological examination of the obtained samples.Results: The obtained data revealed that, the mean diameter of the preovulatory follicles was (3.95±0.34 cm, the plasma estradiol and progestrone levels were (85.98±5.26 pg/mL and (0.73±0.23 ng/mL, respectively, endoscopic monitoring the vagina, cervix and endometrium revealed hyperemic vaginal mucous membrane, soft and opened cervical ostium with abundant estrous mucous and folding, hyperemic and edematous appearance of the endometrium, respectively and the histological features of the biopsical endometrial samples revealed that, The lamina propria-sub mucosa was packed with simple or branched tubular glands lined with simple columnar epithelium showing oval or rounded dark nuclei with different degrees of secretory activities of the glands.Conclusions: The endoscope proved to be a reliable tool for confirming the estrous phase in mares and monitoring the gross features of the vagina, the cervix and the endometrium, in addition to the availability of taking biopsical smears.

  16. Estrous cycle fluctuations in sex and ingestive behavior are accentuated by exercise or cold ambient temperatures.

    Science.gov (United States)

    Abdulhay, Amir; Benton, Noah A; Klingerman, Candice M; Krishnamoorthy, Kaila; Brozek, Jeremy M; Schneider, Jill E

    2014-06-01

    This article is part of a Special Issue "Energy Balance". In female Syrian hamsters (Mesocricetus auratus), low circulating levels of ovarian steroids are associated with increased food hoarding and decreased sexual motivation, but these effects are exaggerated in food-restricted females. To determine whether cold ambient temperature has the same effects as food restriction, groups of hamsters were fed ad libitum while they were housed at either 5 °C or 22 °C, and then tested for behavior for 90 min on each day of the estrous cycle. In females housed at 22 °C, high levels of sexual motivation and low levels of food hoarding were seen every day of the estrous cycle. In females housed at 5 °C, high levels of sexual motivation were restricted to the periovulatory day. On the three nonestrous days, these females showed high levels of food hoarding, but not food intake. A separate cohort of females were provided with access to running wheels and housed at 22 °C. They showed high levels of sexual motivation restricted to the periovulatory day, similar to the pattern of sexual motivation seen in cold-housed females. Unlike cold-housed females, those with running wheels showed low levels of food hoarding and high levels of food intake. Food restriction, cold housing, and access to wheels had no significant effect on plasma estradiol or progesterone concentrations, but significantly decreased plasma leptin concentrations. All three energetic challenges unmask estrous cycle fluctuations in sexual motivation that are obscured in laboratory conditions, i.e., isolation in a small cage with an overabundance of food. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Synchronous colonic tumours of dual pathology.

    Science.gov (United States)

    Basu, S; Selvachandran, S N; Cade, D

    2001-05-01

    Synchronous colonic tumours of dual pathology are extremely rare. A review of the literature revealed that few cases have been reported to date. Because of their rarity and lack of specific symptoms, preoperative diagnosis is not easy and there is no protocol as yet for the ideal management of these cases. We present such a case which was treated by a combination of surgery and chemotherapy.

  18. Insulin binding characteristics in canine muscle tissue: effects of the estrous cycle phases

    Directory of Open Access Journals (Sweden)

    Álan G. Pöppl

    Full Text Available Abstract: Hormonal fluctuations during the different estrous cycle are a well-recognized cause of insulin resistance in bitches, and little is known about insulin receptor binding or post-binding defects associated with insulin resistance in dogs. To evaluate insulin binding characteristics in muscle tissue of bitches during the estrous cycle, 17 owned bitches were used in the study (six in anestrus, five in estrus, and six in diestrus. An intravenous glucose tolerance test (IVGTT was performed in all patients by means of injection of 1mL/kg of a glucose 50% solution (500mg/kg, with blood sample collection for glucose determination at 0, 3, 5, 7, 15, 30, 45 and 60 minutes after glucose infusion. Muscle samples, taken after spaying surgery, were immediately frozen in liquid nitrogen and then stored at -80 ºC until the membranes were prepared by sequential centrifugation after being homogenized. For binding studies, membranes were incubated in the presence of 20,000cpm of human 125I-insulin and in increasing concentrations of unlabeled human regular insulin for cold saturation. The IVGTT showed no differences among bitches during the estrous cycle regarding baseline glycemia or glycemic response after glucose infusion. Two insulin binding sites - high-affinity and low-affinity ones - were detected by Scatchard analysis, and significant statistical differences were observed in the dissociation constant (Kd1 and maximum binding capacity (Bmax1 of the high-affinity binding sites. The Kd1 for the anestrus group (6.54±2.77nM/mg of protein was smaller (P<0.001 than for the estrus (28.54±6.94nM/mg of protein and diestrus (15.56±3.88nM/mg of protein groups. Bmax1 in the estrus (0.83±0.42nM/mg of protein and diestrus (1.24±0.24nM/mg of protein groups were also higher (P<0.001 than the values observed in anestrus (0.35±0.06nM/mg of protein. These results indicate modulation of insulin binding characteristics during different phases of the estrous

  19. Estrous correlated modulations of circadian and ultradian wheel-running activity rhythms in LEW/Ztm rats

    OpenAIRE

    Wollnik, Franziska; Turek, Fred W.

    1988-01-01

    Estrogen treatment alters the expression of ultradian activity rhythms in male and female LEW/Ztm rats. This finding raises the possibility that the expression of ultradian rhythms may vary on different days of the estrous cycle. To test this hypothesis, we recorded the circadian and ultradian wheel-running activity rhythms of entrained (LD 12:12) and free-running sexually mature LEW/Ztm females during their 4- or 5-day estrous cycle. The mean daily activity, the duration of activity, the cir...

  20. Expression of progesterone receptor protein in the ovine uterus during the estrous cycle: Effects of nutrition, arginine and FSH.

    Science.gov (United States)

    Grazul-Bilska, Anna T; Thammasiri, Jiratti; Kraisoon, Aree; Reyaz, Arshi; Bass, Casie S; Kaminski, Samantha L; Navanukraw, Chainarong; Redmer, Dale A

    2018-03-01

    To evaluate expression of progesterone receptor (PGR) AB in follicle stimulating hormone (FSH)-treated or non-treated sheep administered with arginine (Arg) or saline (Sal) fed a control (C), excess (O) or restricted (U) diet, uterine tissues were collected at the early, mid and/or late luteal phases. In exp. 1, ewes from each diet were randomly assigned to one of two treatments, Arg or Sal administration three times daily from day 0 of the first estrous cycle until uterine tissue collection. In exp. 2, ewes were injected twice daily with FSH on days 13-15 of the first estrous cycle. Uterine tissues were immunostained to detect PGR followed by image analysis. PGR were detected in luminal epithelium (LE), endometrial glands (EG), endometrial stroma (ES), myometrium (Myo), and endometrial and myometrial blood vessels. The percentage of PR-positive cells and/or intensity of staining were affected by phase of the estrous cycle, plane of nutrition, and/or FSH but not by Arg. In exp. 1, percentage of PGR-positive cells in LE and EG but not in ES and Myo was greater at the early and mid than late luteal phase, was not affected by plane of nutrition, and was similar in LE and EG. Intensity of staining was affected by phase of the estrous cycle and plane of nutrition in LE, EG and Myo, and was the greatest in LE, less in EG, and least in ES and Myo. In exp. 2, percentage of PGR-positive cells in LE, EG, ES and Myo was affected by phase of the estrous cycle, but not by plane of nutrition; was greater at the early than mid luteal phase; and was greatest in LE and EG, less in luminal (superficial) ES and Myo and least in deep ES. Intensity of staining was affected by phase of the estrous cycle and plane of nutrition in all compartments but ES, and was the greatest in LE and luminal EG, less in deep EG, and least in ES and Myo. Comparison of data for FSH (superovulated) and Sal-treated (non-superovulated) ewes demonstrated that FSH affected PR expression in all evaluated

  1. Effect of summer heat environment on body temperature, estrous cycles and blood antioxidant levels in Japanese Black cow.

    Science.gov (United States)

    Sakatani, Miki; Balboula, Ahmed Z; Yamanaka, Kenichi; Takahashi, Masashi

    2012-05-01

    This study investigated the effect of summer heat environment on estrous cycles and blood antioxidant levels in Japanese Black cows. A total of 13 non-lactating Japanese Black cows (summer: 9, winter: 4) were examined. Body temperature was measured rectally and intravaginally using a thermometer and data logger, respectively. Estrous behavior was monitored using a radiotelemetric pedometer that recorded walking activity. Rectal temperatures were higher during summer than winter (Pstress, and also reduces signs of estrus in Japanese Black cows. © 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

  2. Asynchronized synchronous machines

    CERN Document Server

    Botvinnik, M M

    1964-01-01

    Asynchronized Synchronous Machines focuses on the theoretical research on asynchronized synchronous (AS) machines, which are "hybrids” of synchronous and induction machines that can operate with slip. Topics covered in this book include the initial equations; vector diagram of an AS machine; regulation in cases of deviation from the law of full compensation; parameters of the excitation system; and schematic diagram of an excitation regulator. The possible applications of AS machines and its calculations in certain cases are also discussed. This publication is beneficial for students and indiv

  3. Distributed Synchronization Control of Multiagent Systems With Unknown Nonlinearities.

    Science.gov (United States)

    Su, Shize; Lin, Zongli; Garcia, Alfredo

    2016-01-01

    This paper revisits the distributed adaptive control problem for synchronization of multiagent systems where the dynamics of the agents are nonlinear, nonidentical, unknown, and subject to external disturbances. Two communication topologies, represented, respectively, by a fixed strongly-connected directed graph and by a switching connected undirected graph, are considered. Under both of these communication topologies, we use distributed neural networks to approximate the uncertain dynamics. Decentralized adaptive control protocols are then constructed to solve the cooperative tracker problem, the problem of synchronization of all follower agents to a leader agent. In particular, we show that, under the proposed decentralized control protocols, the synchronization errors are ultimately bounded, and their ultimate bounds can be reduced arbitrarily by choosing the control parameter appropriately. Simulation study verifies the effectiveness of our proposed protocols.

  4. Randomized, controlled trial comparing synchronized intermittent mandatory ventilation and synchronized intermittent mandatory ventilation plus pressure support in preterm infants.

    Science.gov (United States)

    Reyes, Zenaida C; Claure, Nelson; Tauscher, Markus K; D'Ugard, Carmen; Vanbuskirk, Silvia; Bancalari, Eduardo

    2006-10-01

    Prolonged mechanical ventilation is associated with lung injury in preterm infants. In these infants, weaning from synchronized intermittent mandatory ventilation may be delayed by their inability to cope with increased respiratory loads. The addition of pressure support to synchronized intermittent mandatory ventilation can offset these loads and may facilitate weaning. The purpose of this work was to compare synchronized intermittent mandatory ventilation and synchronized intermittent mandatory ventilation plus pressure support in weaning from mechanical ventilation and the duration of supplemental oxygen dependency in preterm infants with respiratory failure. Preterm infants weighing 500 to 1000 g at birth who required mechanical ventilation during the first postnatal week were randomly assigned to synchronized intermittent mandatory ventilation or synchronized intermittent mandatory ventilation plus pressure support. In both groups, weaning followed a set protocol during the first 28 days. Outcomes were assessed during the first 28 days and until discharge or death. There were 107 infants enrolled (53 synchronized intermittent mandatory ventilation plus pressure support and 54 synchronized intermittent mandatory ventilation). Demographic and perinatal data, mortality, and morbidity did not differ between groups. During the first 28 days, infants in the synchronized intermittent mandatory ventilation plus pressure support group reached minimal ventilator settings and were extubated earlier than infants in the synchronized intermittent mandatory ventilation group. Total duration of mechanical ventilation, duration of oxygen dependency, and oxygen need at 36 weeks' postmenstrual age alone or combined with death did not differ between groups. However, infants in synchronized intermittent mandatory ventilation plus pressure support within the 700- to 1000-g birth weight strata had a shorter oxygen dependency. The results of this study suggest that the addition of

  5. C/EBPβ Isoforms Expression in the Rat Brain during the Estrous Cycle

    Directory of Open Access Journals (Sweden)

    Valeria Hansberg-Pastor

    2015-01-01

    Full Text Available The CCAAT/enhancer-binding protein beta (C/EBPβ is a transcription factor expressed in different areas of the brain that regulates the expression of several genes involved in cell differentiation and proliferation. This protein has three isoforms (LAP1, LAP2, and LIP with different transcription activation potential. The role of female sex hormones in the expression pattern of C/EBPβ isoforms in the rat brain has not yet been described. In this study we demonstrate by western blot that the expression of the three C/EBPβ isoforms changes in different brain areas during the estrous cycle. In the cerebellum, LAP2 content diminished on diestrus and proestrus and LIP content diminished on proestrus and estrus days. In the prefrontal cortex, LIP content was higher on proestrus and estrus days. In the hippocampus, LAP isoforms presented a switch on diestrus day, since LAP1 content was the highest while that of LAP2 was the lowest. The LAP2 isoform was the most abundant one in all the three brain areas. The LAP/LIP ratio changed throughout the cycle and was tissue specific. These results suggest that C/EBPβ isoforms expression changes in a tissue-specific manner in the rat brain due to the changes in sex steroid hormone levels presented during the estrous cycle.

  6. Hormonal fluctuations during the estrous cycle modulate Heme Oxygenase-1 expression in the uterus

    Directory of Open Access Journals (Sweden)

    Maria Laura Zenclussen

    2014-03-01

    Full Text Available Deletion of the Heme Oxygenase-1 (Hmox1 locus in mice results in intrauterine lethality. The expression of the heme catabolyzing enzyme encoded by this gene, namely HO 1, is required to successfully support reproductive events. We have previously observed that HO-1 acts at several key events in reproduction ensuring pregnancy. HO-1 defines ovulation, positively influences implantation and placentation and ensures fetal growth and survival. Here, we embarked on a study aimed to determine whether hormonal changes during the estrous cycle in the mouse define HO-1 expression, thus influencing receptivity. We analyzed the serum levels of progesterone and estrogen by ELISA and HO-1 mRNA expression in uterus by real time RT-PCR at the metestrus, proestrus, estrus and diestrus phases of the estrous cycle. Further, we studied the HO-1 protein expression by Western Blot upon hormone addition to cultured uterine AN3 cells. We observed that HO-1 variations in uterine tissue correlated to changes in hormonal levels at different phases of the estrus cycle. In vitro, HO-1 protein levels in AN3 cells augmented after the addition of physiological concentrations of progesterone and estradiol, which confirmed our in vivo observations. Our data suggest an important role for hormones in HO-1 regulation in uterus that has a significant impact in receptivity and later on blastocyst implantation.

  7. Synchronization of networks

    Indian Academy of Sciences (India)

    We study the synchronization of coupled dynamical systems on networks. The dynamics is .... Such a time-varying topology can occur in social networks, computer networks, WWW ... This has the effect of reducing the spread of the transverse ...

  8. Synchronization in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. DIFFRACTION SYNCHRONIZATION OF LASERS,

    Science.gov (United States)

    semiconductor lasers while suppressing parasitic generation in the plane of the mirror. The diffraction coupling coefficient of open resonators is calculated, and the stability conditions of the synchronized system is determined.

  10. Traffic signal synchronization.

    Science.gov (United States)

    Huang, Ding-wei; Huang, Wei-neng

    2003-05-01

    The benefits of traffic signal synchronization are examined within the cellular automata approach. The microsimulations of traffic flow are obtained with different settings of signal period T and time delay delta. Both numerical results and analytical approximations are presented. For undersaturated traffic, the green-light wave solutions can be realized. For saturated traffic, the correlation among the traffic signals has no effect on the throughput. For oversaturated traffic, the benefits of synchronization are manifest only when stochastic noise is suppressed.

  11. Files synchronization from a large number of insertions and deletions

    Science.gov (United States)

    Ellappan, Vijayan; Kumari, Savera

    2017-11-01

    Synchronization between different versions of files is becoming a major issue that most of the applications are facing. To make the applications more efficient a economical algorithm is developed from the previously used algorithm of “File Loading Algorithm”. I am extending this algorithm in three ways: First, dealing with non-binary files, Second backup is generated for uploaded files and lastly each files are synchronized with insertions and deletions. User can reconstruct file from the former file with minimizing the error and also provides interactive communication by eliminating the frequency without any disturbance. The drawback of previous system is overcome by using synchronization, in which multiple copies of each file/record is created and stored in backup database and is efficiently restored in case of any unwanted deletion or loss of data. That is, to introduce a protocol that user B may use to reconstruct file X from file Y with suitably low probability of error. Synchronization algorithms find numerous areas of use, including data storage, file sharing, source code control systems, and cloud applications. For example, cloud storage services such as Drop box synchronize between local copies and cloud backups each time users make changes to local versions. Similarly, synchronization tools are necessary in mobile devices. Specialized synchronization algorithms are used for video and sound editing. Synchronization tools are also capable of performing data duplication.

  12. Protecting Clock Synchronization: Adversary Detection through Network Monitoring

    Directory of Open Access Journals (Sweden)

    Elena Lisova

    2016-01-01

    Full Text Available Nowadays, industrial networks are often used for safety-critical applications with real-time requirements. Such applications usually have a time-triggered nature with message scheduling as a core property. Scheduling requires nodes to share the same notion of time, that is, to be synchronized. Therefore, clock synchronization is a fundamental asset in real-time networks. However, since typical standards for clock synchronization, for example, IEEE 1588, do not provide the required level of security, it raises the question of clock synchronization protection. In this paper, we identify a way to break synchronization based on the IEEE 1588 standard, by conducting a man-in-the-middle (MIM attack followed by a delay attack. A MIM attack can be accomplished through, for example, Address Resolution Protocol (ARP poisoning. Using the AVISPA tool, we evaluate the potential to perform a delay attack using ARP poisoning and analyze its consequences showing both that the attack can, indeed, break clock synchronization and that some design choices, such as a relaxed synchronization condition mode, delay bounding, and using knowledge of environmental conditions, can make the network more robust/resilient against these kinds of attacks. Lastly, a Configuration Agent is proposed to monitor and detect anomalies introduced by an adversary performing attacks targeting clock synchronization.

  13. Glucose intolerance develops prior to increased adiposity and accelerated cessation of estrous cyclicity in female growth-restricted rats

    Science.gov (United States)

    Intapad, Suttira; Dasinger, John Henry; Brown, Andrew D.; Fahling, Joel M.; Esters, Joyee; Alexander, Barbara T.

    2015-01-01

    Background The incidence of metabolic disease increases in early menopause. Low birth weight influences the age at menopause. Thus, this study tested the hypothesis that intrauterine growth restriction programs early reproductive aging and impaired glucose homeostasis in female rats. Methods Estrous cyclicity, body composition, and glucose homeostasis were determined in female control and growth-restricted rats at 6 and 12 months of age; sex steroids at 12 months. Results Glucose intolerance was present at 6 months of age prior to cessation of estrous cyclicity and increased adiposity in female growth-restricted rats. However, female growth-restricted rats exhibited persistent estrus and a significant increase in adiposity, fasting glucose and testosterone at 12 months of age (Pgrowth-restricted rats (Pgrowth programmed glucose intolerance that developed prior to early estrous acyclicity; yet, fasting glucose levels were elevated in conjunction with increased adiposity, accelerated cessation of estrous cyclicity and a shift towards testosterone excess at 12 months of age in female growth-restricted rats. PMID:26854801

  14. Stress and estrous cycle affect strategy but not performance of female C57BL/6J mice

    NARCIS (Netherlands)

    ter Horst, J.P.; Kentrop, J.; de Kloet, E.R.; Oitzl, M.S.

    2013-01-01

    Stress induces a switch in learning strategies of male C57BL/6J mice from predominantly spatial to more stimulus-response learning. To study generalization of these findings over sex, we investigated female C57BL/6J mice at three phases of the estrous cycle under non stress and acute (10 min)

  15. Estrogen-dependent expression of sine oculis homeobox 1 in the mouse uterus during the estrous cycle

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sijeong [Department of Biomedical Science, CHA University, Seongnam-si, Gyeonggi-do 13488 (Korea, Republic of); Kwon, Hwang [Fertility Center of CHA Bundang Medical Center, Seongnam-si, Gyeonggi-do 13496 (Korea, Republic of); Yoon, Hyemin [Department of Biomedical Science, CHA University, Seongnam-si, Gyeonggi-do 13488 (Korea, Republic of); Park, Miseon [Fertility Center of CHA Gangnam Medical Center, Seoul 06135 (Korea, Republic of); Kim, Hye-Ryun; Song, Haengseok [Department of Biomedical Science, CHA University, Seongnam-si, Gyeonggi-do 13488 (Korea, Republic of); Hong, Kwonho, E-mail: kwonho.hong@dankook.ac.kr [Department of Nanobiomedical Science & BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan-si, Chungcheongnam-do 31116 (Korea, Republic of); Choi, Youngsok, E-mail: youngsokchoi@cha.ac.kr [Department of Biomedical Science, CHA University, Seongnam-si, Gyeonggi-do 13488 (Korea, Republic of); Fertility Center of CHA Gangnam Medical Center, Seoul 06135 (Korea, Republic of)

    2016-04-08

    The sine oculis homeobox 1 (SIX1) is a member of the Six gene family. SIX1 is involved in tissue development by regulating proliferation, apoptosis, and differentiation. However, function of SIX1 in the uterus remains unknown. Here, we found that Six1 expression is regulated along the estrous cycle in mouse uterus. Six1 expression was significantly increased at estrus stage and decreased at the rest of stages. SIX1 is detected in the luminal and glandular epithelium of uterine endometrium at the estrus stage. Estrogen injection increased Six1 expression in the ovariectomized mouse uterus, whereas progesterone had no effect on its expression. Estrogen receptor antagonist inhibited estrogen-induced Six1 expression. Our findings imply that SIX1 may play a role as an important regulator to orchestrate the dynamic of uterine endometrium in response to estrogen level during the estrous cycle. These results will give us a better understanding of uterine biology. - Highlights: • Six1 expression is regulated during the estrous cycle in mouse uterus. • Six1 is highly expressed at the estrus stage of estrous cycle. • SIX1 is detected in luminal/glandular epithelium of the uterus at the estrus stage. • Estrogen stimulates Six1 expression in an estrogen receptor-dependent manner.

  16. Assessment of estrous cycle, ovarian and uterine tissue and fetal parameters of Wistar rats treated with Topiramate

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Cherici Camargo

    2017-01-01

    Full Text Available Topiramate (TPM is included in the newer generation of antiepileptic drugs and is known to have multiple mechanisms of action. The drug has also been used for reducing body weight. Its effect on reproductive tissues and estrous cycle deserve greater attention. Then, this study aimed to investigate possible effects of the drug on ovarian and uterine tissues, estrous cycle and some fetal parameters of non-epileptic Wistar rats. In Experiment I, females received tap water (C - Control group; n=8 or Topiramate (TPM group; 100 mg/kg; n=8, orally for 6 weeks. The estrous cycle and food consumption were monitored. Ovarian and uterine sections were examined under light microscopy. In Experiment II, pregnant rats of C and TPM groups received treatments during the pre-implantation, implantation or organogenesis period. In females of Experiment I, TPM had no effect on the food consumption, final body weight, weekly body weight and estrous cycle. Ovarian and uterine weight was similar in both groups. The kinetics of folliculogenesis was unaffected by treatment with the drug. There was a significant (p<0.05 decrease in endometrial thickness of TPM-group. In Experiment II, fetal weight was decreased (p<0.05 in all periods of TPM exposure. There was no effect of treatment on fetal external morphology. In conclusion, the findings indicate that TPM promotes discrete alterations in the uterine tissue, and causes decrease on the fetus weight after exposure in different gestational periods.

  17. Enhancing Time Synchronization Support in Wireless Sensor Networks

    Science.gov (United States)

    Tavares Bruscato, Leandro; Heimfarth, Tales; Pignaton de Freitas, Edison

    2017-01-01

    With the emerging Internet of Things (IoT) technology becoming reality, a number of applications are being proposed. Several of these applications are highly dependent on wireless sensor networks (WSN) to acquire data from the surrounding environment. In order to be really useful for most of applications, the acquired data must be coherent in terms of the time in which they are acquired, which implies that the entire sensor network presents a certain level of time synchronization. Moreover, to efficiently exchange and forward data, many communication protocols used in WSN rely also on time synchronization among the sensor nodes. Observing the importance in complying with this need for time synchronization, this work focuses on the second synchronization problem, proposing, implementing and testing a time synchronization service for low-power WSN using low frequency real-time clocks in each node. To implement this service, three algorithms based on different strategies are proposed: one based on an auto-correction approach, the second based on a prediction mechanism, while the third uses an analytical correction mechanism. Their goal is the same, i.e., to make the clocks of the sensor nodes converge as quickly as possible and then to keep them most similar as possible. This goal comes along with the requirement to keep low energy consumption. Differently from other works in the literature, the proposal here is independent of any specific protocol, i.e., it may be adapted to be used in different protocols. Moreover, it explores the minimum number of synchronization messages by means of a smart clock update strategy, allowing the trade-off between the desired level of synchronization and the associated energy consumption. Experimental results, which includes data acquired from simulations and testbed deployments, provide evidence of the success in meeting this goal, as well as providing means to compare these three approaches considering the best synchronization

  18. Enhancing Time Synchronization Support in Wireless Sensor Networks.

    Science.gov (United States)

    Tavares Bruscato, Leandro; Heimfarth, Tales; Pignaton de Freitas, Edison

    2017-12-20

    With the emerging Internet of Things (IoT) technology becoming reality, a number of applications are being proposed. Several of these applications are highly dependent on wireless sensor networks (WSN) to acquire data from the surrounding environment. In order to be really useful for most of applications, the acquired data must be coherent in terms of the time in which they are acquired, which implies that the entire sensor network presents a certain level of time synchronization. Moreover, to efficiently exchange and forward data, many communication protocols used in WSN rely also on time synchronization among the sensor nodes. Observing the importance in complying with this need for time synchronization, this work focuses on the second synchronization problem, proposing, implementing and testing a time synchronization service for low-power WSN using low frequency real-time clocks in each node. To implement this service, three algorithms based on different strategies are proposed: one based on an auto-correction approach, the second based on a prediction mechanism, while the third uses an analytical correction mechanism. Their goal is the same, i.e., to make the clocks of the sensor nodes converge as quickly as possible and then to keep them most similar as possible. This goal comes along with the requirement to keep low energy consumption. Differently from other works in the literature, the proposal here is independent of any specific protocol, i.e., it may be adapted to be used in different protocols. Moreover, it explores the minimum number of synchronization messages by means of a smart clock update strategy, allowing the trade-off between the desired level of synchronization and the associated energy consumption. Experimental results, which includes data acquired from simulations and testbed deployments, provide evidence of the success in meeting this goal, as well as providing means to compare these three approaches considering the best synchronization

  19. Chaotic map based key agreement with/out clock synchronization

    International Nuclear Information System (INIS)

    Han, S.; Chang, E.

    2009-01-01

    In order to address Bergamo et al.'s attack, Xiao et al. proposed a key agreement protocol using chaotic maps. Han then presented three attacks on Xiao et al.'s protocol. To enhance the security of key agreement based on chaotic maps, Chang et al. proposed a new key agreement using passphrase, which works in clock synchronization environment. However, their protocol still has some issues: one is its passphrase is not easy to remember and much longer than password; the second one is it cannot resist guessing attack if the constructed passphrase is easy to remember and also has already existed in some rational dictionaries; the third one is it cannot work without clock synchronization. In this paper, we will present two different key agreement protocols, which can resist guessing attack. The first one works in clock synchronization environment. The second one can work without clock synchronization. They both use authenticated password for secure communications. The protocols are secure against replaying attacks and a shared session key can be established.

  20. Different enzymatic antioxidative pathways operate within the sheep caruncular and intercaruncular endometrium throughout the estrous cycle and early pregnancy.

    Science.gov (United States)

    Al-Gubory, K H; Faure, P; Garrel, C

    2017-09-01

    There has been a growing interest in the role played by antioxidant enzymes in the regulation of endometrial function in mammals. However, little is known about enzymatic antioxidative pathways involved in conditioning the cyclic and early pregnant endometrium for conceptus attachment and implantation in domestic ruminants. We aimed to investigate changes in activities of superoxide dismutase 1 and 2 (SOD1, SOD2), glutathione peroxidase (GPX), glutathione reductase (GR) and catalase (CAT) in sheep caruncles (CAR) and intercaruncles (ICAR) endometrial tissues of cyclic and early pregnant ewes. Irrespective of day of cycle or pregnancy, CAR demonstrated higher activities of SOD1 and SOD2 than in ICAR. On day 12 of the estrous cycle, ICAR demonstrated higher activity of GPX and GR than in CAR tissues. On days 12 and 16 the estrous cycle, ICAR demonstrated higher activity of CAT than in CAR. CAR demonstrated higher activity of GPX on day 18 than on days 4, 8, 12 and 16 of the estrous cycle. CAR demonstrated higher activity of CAT on day 18 than on days 4, 8, 12 and 16 of the estrous cycle. ICAR demonstrated higher activity of CAT on day 18 than on days 4, 8, and 16 of the estrous cycle. The activity of CAT in ICAR increased from days 4 and 8 to day 12 of the estrous cycle. The activity of SOD2 in CAR increased from day 16 to day 18 of pregnancy. On day 12 of pregnancy, CAR demonstrated higher activity of GPX than in ICAR. On day 16 of pregnancy, ICAR demonstrated higher activity of GPX than in CAR. The activity of GPX in ICAR increased from day 12 to day 16 of pregnancy. The activity of GPX in CAR increased from day 16 to day 18 of pregnancy. The activity of GR in CAR and ICAR increased from days 12 and 16 to day 18 of pregnancy. On days 16 and 18 of pregnancy, ICAR demonstrated higher activity of CAT than in CAR. The activity of CAT in CAR decreased from day 12 to days 16 and 18 of pregnancy. The activity of CAT in ICAR decreased from day 12 to day 16 of pregnancy and

  1. Estrous cycle characterisation and artificial insemination using frozen-thawed spermatozoa in the bottlenose dolphin (Tursiops truncatus).

    Science.gov (United States)

    Robeck, T R; Steinman, K J; Yoshioka, M; Jensen, E; O'Brien, J K; Katsumata, E; Gili, C; McBain, J F; Sweeney, J; Monfort, S L

    2005-05-01

    The reproductive endocrinology of the bottlenose dolphin, Tursiops truncatus, was characterized to facilitate the development of artificial insemination using cryopreserved spermatozoa. Specific objectives were: (i) to determine the excretory dynamics of urinary luteinizing hormone (LH) and ovarian steroid metabolites during the estrous cycle; (ii) to evaluate the effect of an exogenously administered synthetic progesterone analog (altrenogest) on reproductive hormone excretion; (iii) to correlate follicular growth and ovulation (as determined by transabdominal ultrasound) to urinary LH and ovarian steroid metabolites; (iv) examine the in vivo fertilisation capacity of cryopreserved semen, and (v) to develop an intrauterine insemination technique. Based on urinary endocrine monitoring of natural estrous cycles (2 consecutive cycles) and nine post altrenogest cycles in ten females, estrous cycles were found to be 36 days long and comprised of an 8 day and 19 day follicular and luteal phase, respectively. Peak estrogen conjugates (EC; 5.4+/-3.8 ng/mg creatinine (Cr)) occurred 8 h prior to the LH surge (70.9+/-115.7 ng/mg Cr). The time of ovulation, as determined by ultrasonography, occurred 32.1+/-8.9 h and 24.3+/-7.0 h after the onset of the LH surge and LH peak, respectively. Mean preovulatory follicular diameter and circumference were 2.1+/-0.5 cm and 6.5+/-1.5 cm, respectively. Of the 27 estrous synchronisation attempts, 13 resulted in an ovulatory cycle, with ovulation occurring 21 days post-altrenogest treatment. Intrauterine (4 of 5) and intracornual (1 of 3) inseminations conducted across eight estrous cycles resulted in five pregnancies (63%), one pregnancy resulted from the use of liquid stored semen, whereas four were achieved using cryopreserved semen. These data provide new information on female bottlenose dolphin reproductive physiology, and demonstrate that the combination of endocrine monitoring and serial ultrasonography contributed to successful AI

  2. Continuous exposure to sexually active rams extends estrous activity in ewes in spring.

    Science.gov (United States)

    Abecia, J A; Chemineau, P; Flores, J A; Keller, M; Duarte, G; Forcada, F; Delgadillo, J A

    2015-12-01

    Sexual activity in sheep is under photoperiodic control, which is the main environmental factor responsible for the seasonality of reproduction. However, other natural environmental factors such as presence of conspecifics can slightly influence the timing of onset and offset of the breeding season. In goats, we have found that the continuous presence of bucks that were rendered sexually active out of season by previous exposure to long days, prevented goats from displaying seasonal anestrus, which suggests that the relative contribution of photoperiod in controlling seasonal anestrus should be reevaluated in small ruminant species. The aim of this study was to assess whether the presence of sexually active rams that had been stimulated by artificial photoperiod and melatonin implants, reduces seasonal anestrus in sheep, by prolonging ovulatory activity in spring. Ewes were assigned to one of two groups (n = 16 and 15), which were housed in two separate barns, and kept in contact, either with the treated or the control rams between March and July. Vasectomized rams were either exposed to 2 months of long days followed by the insertion of three subcutaneous melatonin implants (treated rams, n = 8), or exposed to natural light conditions (control rams, n = 2). Estrus was monitored daily, and weekly plasma progesterone analyses indicated ovulatory activity. Ewes that were exposed to treated rams exhibited a higher proportion of monthly estrus than ewes exposed to the control rams (P ewes (one ewe was not considered because of the presence of persistent CL) exposed to stimulated rams exhibited estrous behavior in a cyclic manner. In contrast, all ewes exposed to control rams stopped estrous activity for a period of time during the study, such that this group exhibited a significantly longer anestrous season (mean ± standard error of the mean 89 ± 9 days) than did the ewes housed with treated rams (26 ± 10 days; P ewes housed with treated rams, 13 of

  3. Robust Timing Synchronization in Aeronautical Mobile Communication Systems

    Science.gov (United States)

    Xiong, Fu-Qin; Pinchak, Stanley

    2004-01-01

    the rankings of the Gardner Zero-Crossing Detector and both versions of the Early-Late Gate Synchronizer. The least robust models are the high and low-sample-rate Sliding Window Synchronizers. Consequently, the recommended replacement synchronizer for NASA's Advanced Air Transportation Technologies mobile aeronautical communications system is the high-sample-rate Modified Sliding Window Synchronizer. By incorporating this synchronizer into their system, NASA can be assured that their system will be operational in extremely adverse conditions. The quick convergence time of the MSWS should allow the use of high-level protocols. However, if NASA feels that reduced system complexity is the most important aspect of their replacement synchronizer, the Gardner Zero-Crossing Detector would be the best choice.

  4. Extension of Pairwise Broadcast Clock Synchronization for Multicluster Sensor Networks

    Directory of Open Access Journals (Sweden)

    Bruce W. Suter

    2008-01-01

    Full Text Available Time synchronization is crucial for wireless sensor networks (WSNs in performing a number of fundamental operations such as data coordination, power management, security, and localization. The Pairwise Broadcast Synchronization (PBS protocol was recently proposed to minimize the number of timing messages required for global network synchronization, which enables the design of highly energy-efficient WSNs. However, PBS requires all nodes in the network to lie within the communication ranges of two leader nodes, a condition which might not be available in some applications. This paper proposes an extension of PBS to the more general class of sensor networks. Based on the hierarchical structure of the network, an energy-efficient pair selection algorithm is proposed to select the best pairwise synchronization sequence to reduce the overall energy consumption. It is shown that in a multicluster networking environment, PBS requires a far less number of timing messages than other well-known synchronization protocols and incurs no loss in synchronization accuracy. Moreover, the proposed scheme presents significant energy savings for densely deployed WSNs.

  5. Improved SIRAP analysis for synchronization in hierarchical scheduled real-time systems

    NARCIS (Netherlands)

    Behnam, M.; Bril, R.J.; Nolte, T.

    2009-01-01

    We present our ongoing work on synchronization in hierarchical scheduled real-time systems, where tasks are scheduled using fixed-priority pre-emptive scheduling. In this paper, we show that the original local schedulability analysis of the synchronization protocol SIRAP [4] is very pessimistic when

  6. A Semantics of Synchronization.

    Science.gov (United States)

    1980-09-01

    suggestion of having very hungry philosophers. One can easily imagine the complexity of the equivalent implementation using semaphores . Synchronization types...Edinburgh, July 1978. [STAR79] Stark, E.W., " Semaphore Primitives and Fair Mutual Exclusion," TM-158, Laboratory for Computer Science, M.I.T., Cambridge...AD-AQ91 015 MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR COMPUTE--ETC F/S 9/2 A SEMANTICS OF SYNCHRONIZATION .(U) .C SEP 80 C A SEAQUIST N00015-75

  7. Pulse Synchronization System (PSS)

    International Nuclear Information System (INIS)

    1977-06-01

    This document is intended to serve as an operations manual, as well as a documentation of the backup analyses pertinent to the design as delivered. A history of earlier unsuccessful versions of the Pulse Synchronization System (PSS) is not included. The function of the PSS is to synchronize the time of arrival at the fusion target of laser pulses that are propagated through the 20 amplifier chains of the SHIVA laser. The positional accuracy requirement is +-1.5 mm (+-5 psec), and is obtained by the PSS with a wide margin factor

  8. Synchronization of Budding Yeast by Centrifugal Elutriation.

    Science.gov (United States)

    Rosebrock, Adam P

    2017-01-03

    In yeast, cell size is normally tightly linked to cell cycle progression. Centrifugal elutriation is a method that fractionates cells based on the physical properties of cell size-fluid drag and buoyant density. Using a specially modified centrifuge and rotor system, cells can be physically separated into one or more cohorts of similar size and therefore cell cycle position. Small G 1 daughters are collected first, followed by successively larger cells. Elutriated populations can be analyzed immediately or can be returned to medium and permitted to synchronously progress through the cell cycle. This protocol describes two different elutriation methods. In the first, one or more fractions of synchronized cells are obtained from an asynchronous starting population, reincubated, and followed prospectively across a time series. In the second, an asynchronous starting population is separated into multiple fractions of similarly sized cells, and each cohort of similarly sized cells can be analyzed separately without further growth. © 2017 Cold Spring Harbor Laboratory Press.

  9. A Shared Scratchpad Memory with Synchronization Support

    DEFF Research Database (Denmark)

    Hansen, Henrik Enggaard; Maroun, Emad Jacob; Kristensen, Andreas Toftegaard

    2017-01-01

    Multicore processors usually communicate via shared memory, which is backed up by a shared level 2 cache and a cache coherence protocol. However, this solution is not a good fit for real-time systems, where we need to provide tight guarantees on execution and memory access times. In this paper, we...... propose a shared scratchpad memory as a time-predictable communication and synchronization structure, instead of the level 2 cache. The shared on-chip memory is accessed via a time division multiplexing arbiter, isolating the execution time of load and store instructions between processing cores....... Furthermore, the arbiter supports an extended time slot where an atomic load and store instruction can be executed to implement synchronization primitives. In the evaluation we show that a shared scratchpad memory is an efficient communication structure for a small number of processors; in our setup, 9 cores...

  10. Dietary Deficiency of Essential Amino Acids Rapidly Induces Cessation of the Rat Estrous Cycle

    Science.gov (United States)

    Bannai, Makoto; Ichimaru, Toru; Nakano, Sayako; Murata, Takuya; Higuchi, Takashi; Takahashi, Michio

    2011-01-01

    Reproductive functions are regulated by the sophisticated coordination between the neuronal and endocrine systems and are sustained by a proper nutritional environment. Female reproductive function is vulnerable to effects from dietary restrictions, suggesting a transient adaptation that prioritizes individual survival over reproduction until a possible future opportunity for satiation. This adaptation could also partially explain the existence of amenorrhea in women with anorexia nervosa. Because amino acid nutritional conditions other than caloric restriction uniquely alters amino acid metabolism and affect the hormonal levels of organisms, we hypothesized that the supply of essential amino acids in the diet plays a pivotal role in the maintenance of the female reproductive system. To test this hypothesis, we examined ovulatory cyclicity in female rats under diets that were deficient in threonine, lysine, tryptophan, methionine or valine. Ovulatory cyclicity was monitored by daily cytological evaluations of vaginal smears. After continuous feeding of the deficient diet, a persistent diestrus or anovulatory state was induced most quickly by the valine-deficient diet and most slowly by the lysine-deficient diet. A decline in the systemic insulin-like growth factor 1 level was associated with a dietary amino acid deficiency. Furthermore, a paired group of rats that were fed an isocaloric diet with balanced amino acids maintained normal estrous cyclicity. These disturbances of the estrous cycle by amino acid deficiency were quickly reversed by the consumption of a normal diet. The continuous anovulatory state in this study is not attributable to a decrease in caloric intake but to an imbalance in the dietary amino acid composition. With a shortage of well-balanced amino acid sources, reproduction becomes risky for both the mother and the fetus. It could be viewed as an adaptation to the diet, diverting resources away from reproduction and reallocating them to

  11. Genomic priming of the antisecretory response to estrogen in rat distal colon throughout the estrous cycle.

    LENUS (Irish Health Repository)

    O'Mahony, Fiona

    2009-11-01

    The secretion of Cl(-) across distal colonic crypt cells provides the driving force for the movement of fluid into the luminal space. 17beta-Estradiol (E2) produces a rapid and sustained reduction in secretion in females, which is dependent on the novel protein kinase C delta (PKC delta) isozyme and PKA isoform I targeting of KCNQ1 channels. This sexual dimorphism in the E2 response is associated with a higher expression level of PKC delta in female compared with the male tissue. The present study revealed the antisecretory response is regulated throughout the female reproductive (estrous) cycle and is primed by genomic regulation of the kinases. E2 (1-10 nm) decreased cAMP-dependent secretion in colonic epithelia during the estrus, metestrus, and diestrus stages. A weak inhibition of secretion was demonstrated in the proestrus stage. The expression levels of PKC delta and PKA fluctuated throughout the estrous cycle and correlated with the potency of the antisecretory effect of E2. The expression of PKC delta and PKA were up-regulated by estrogen at a transcriptional level via a PKC delta-MAPK-cAMP response element-binding protein-regulated pathway indicating a genomic priming of the antisecretory response. PK Cdelta was activated by the membrane-impermeant E2-BSA, and this response was inhibited by the estrogen receptor antagonist ICI 182,780. The 66-kDa estrogen receptor-alpha isoform was present at the plasma membrane of female colonic crypt cells with a lower abundance found in male colonic crypts. The study demonstrates estrogen regulation of intestinal secretion both at a rapid and transcriptional level, demonstrating an interdependent relationship between both nongenomic and genomic hormone responses.

  12. Global synchronization algorithms for the Intel iPSC/860

    Science.gov (United States)

    Seidel, Steven R.; Davis, Mark A.

    1992-01-01

    In a distributed memory multicomputer that has no global clock, global processor synchronization can only be achieved through software. Global synchronization algorithms are used in tridiagonal systems solvers, CFD codes, sequence comparison algorithms, and sorting algorithms. They are also useful for event simulation, debugging, and for solving mutual exclusion problems. For the Intel iPSC/860 in particular, global synchronization can be used to ensure the most effective use of the communication network for operations such as the shift, where each processor in a one-dimensional array or ring concurrently sends a message to its right (or left) neighbor. Three global synchronization algorithms are considered for the iPSC/860: the gysnc() primitive provided by Intel, the PICL primitive sync0(), and a new recursive doubling synchronization (RDS) algorithm. The performance of these algorithms is compared to the performance predicted by communication models of both the long and forced message protocols. Measurements of the cost of shift operations preceded by global synchronization show that the RDS algorithm always synchronizes the nodes more precisely and costs only slightly more than the other two algorithms.

  13. Estrous cycle modulation of extracellular serotonin in mediobasal hypothalamus: role of the serotonin transporter and terminal autoreceptors.

    Science.gov (United States)

    Maswood, S; Truitt, W; Hotema, M; Caldarola-Pastuszka, M; Uphouse, L

    1999-06-12

    In vivo microdialysis was used to examine extracellular serotonin (5-HT) in the mediobasal hypothalamus (MBH) of male and female Fischer (CDF-344) rats. Females from the stages of diestrus, proestrus, and estrus were used. Additionally, ovariectomized rats, primed subcutaneously (s.c.) with estradiol benzoate or estradiol benzoate plus progesterone were examined. Extracellular 5-HT in the MBH varied with stage of the estrous cycle and with the light/dark cycle. Proestrous females had the highest microdialysate concentrations of 5-HT during the light portion of the light/dark cycle and lowest concentrations during the dark portion of the cycle. Diestrous females had the highest levels during the dark portion of the cycle, while males and estrous females showed little change between light and dark portions of the cycle. In ovariectomized rats, there was no effect of 2.5 microg or 25 microg estradiol benzoate (s.c.) on extracellular 5-HT; but the addition of 500 microg progesterone, 48 h after estrogen priming, reduced microdialysate 5-HT near the threshold for detection. In intact females and in males, reverse perfusion with 3 microM fluoxetine, a selective serotonin reuptake inhibitor (SSRI), or 2 microM methiothepin, a 5-HT receptor antagonist, increased microdialysate concentrations of 5-HT. Estrous females and males showed nearly a 4-fold increase in microdialysate 5-HT in response to fluoxetine while smaller responses were seen in diestrous and proestrous rats. In contrast, proestrous rats showed the largest response to methiothepin. Estrous females showed a delayed response to methiothepin, but there was no methiothepin-induced increase in extracellular 5-HT in males. These findings are discussed in reference to the suggestion that extracellular 5-HT in the MBH is regulated in a manner that is gender and estrous cycle dependent. The 5-HT terminal autoreceptor may exert a greater role in proestrous females; the serotonin transporter appears to play a more active

  14. Calcium and magnesium concentrations in uterine fluid and blood serum during the estrous cycle in the bovine

    Directory of Open Access Journals (Sweden)

    Sayed Mortaza Alavi-Shoushtari

    2012-06-01

    Full Text Available To investigate uterine and serum Ca++ and Mg++ variations during the estrous cycle in the bovine, 66 genital tracts and blood samples were collected from Urmia abattoir, Urmia, Iran. The phase of the estrous cycle was determined by examination of the structures present on ovaries and uterine tonicity. Of the collected samples, 17 were pro-estrus, 12 estrus, 14 metestrus and 23 diestrus. The uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. The mean ± SEM concentration of serum Ca++ in pro-estrus, estrus, metestrus and diestrus was 5.77 ± 0.69, 8.87 ± 1.83, 10.95 ± 1.52, 11.09 ± 1.08 mg dL-1, and the mean concentration of uterine fluid Ca++ was 4.40 ± 0.72, 3.15 ± 0.67, 5.89 ± 0.88, 8.63 ± 0.97 mg dL-1, respectively. The mean concentration of serum Mg++ in pro-estrus, estrus, metestrus and diestrus was 3.53 ± 0.30, 4.20 ± 0.52, 3.49 ± 0.38, 3.39 ± 0.29 mg dL-1, and mean concentration of uterine fluid Mg++ was 5.27 ± 0.42, 4.92 ± 0.60, 5.56 ± 0.30, 5.88 ± 0.36 mg dL-1, respectively. The serum and uterine fluid Ca++ in pro-estrus were significantly different from those of the metestrus and diestrus. In all stages of estrous cycle the mean concentration of serum Ca++ was higher than that in the uterine fluid. The difference between serum and uterine fluid Ca++ in estrus, metestrus and diestrus was significant. There was no significant difference between serum Mg++ content nor was it different from uterine fluid Mg++ content at any stages of estrous cycle. In all stages of estrous cycle the uterine fluid Mg++ was higher than that of the serum. These results suggest that during the estrous cycle in the cow, Ca++ is passively secreted in uterine fluids and is mostly dependent on blood serum Ca++ variations but Mg++ is secreted independently and does not follow variations in the serum concentrations.

  15. Synchronization of networks

    Indian Academy of Sciences (India)

    We study the synchronization of coupled dynamical systems on networks. The dynamics is governed by a local nonlinear oscillator for each node of the network and interactions connecting different nodes via the links of the network. We consider existence and stability conditions for both single- and multi-cluster ...

  16. Heartbeat synchronized with ventilation

    Science.gov (United States)

    Schäfer, Carsten; Rosenblum, Michael G.; Kurths, Jürgen; Abel, Hans-Henning

    1998-03-01

    It is widely accepted that cardiac and respiratory rhythms in humans are unsynchronised. However, a newly developed data analysis technique allows any interaction that does occur in even weakly coupled complex systems to be observed. Using this technique, we found long periods of hidden cardiorespiratory synchronization, lasting up to 20 minutes, during spontaneous breathing at rest.

  17. Synchronous, bilateral tonsillar carcinomas

    DEFF Research Database (Denmark)

    Nami Saber, Camelia; Grønhøj, Christian; Jensen, David Hebbelstrup

    2017-01-01

    INTRODUCTION: The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing, but data on the incidence of synchronous, bilateral tonsillar squamous cell carcinomas (BiTSCCs) is sparse. In this study, we report the incidence and tumour characteristics of BiTSCCs in a population-base...

  18. Presence of a Temperature Gradient Among Genital Tract Portions and the Thermal Changes Within These Portions Over the Estrous Cycle in Beef Cows

    OpenAIRE

    EL-SHEIKH ALI, Hossam; KITAHARA, Go; TAMURA, Youji; KOBAYASHI, Ikuo; HEMMI, Koichiro; TORISU, Shidow; SAMESHIMA, Hiroshi; HORII, Yoichiro; ZAABEL, Samy; KAMIMURA, Shunichi

    2012-01-01

    Abstract The aim of the present study was to describe the temperature of the different portions of the female genital tract and their relation to rectal temperature and to investigate the effect of steroid hormones profiles on these variables over the estrous cycle in cattle. Four nonpregnant Japanese Black cows were investigated daily over two successive estrous cycles using a digital thermometer with a long probe and rounded-end sensor to record the temperature of the rectum (RT), vagina (V...

  19. Injuries in synchronized skating.

    Science.gov (United States)

    Dubravcic-Simunjak, S; Kuipers, H; Moran, J; Simunjak, B; Pecina, M

    2006-06-01

    Synchronized skating is a relatively new competitive sport and data about injuries in this discipline are lacking. Therefore the purpose of this study was to investigate the frequency and pattern of acute and overuse injuries in synchronized skaters. Before and during the World Synchronized Skating Championship 2004, a questionnaire inquiring about the frequency of injuries in this skating discipline was given to 23 participating teams. A total of 514 women and 14 men senior skaters completed the questionnaires (100 % response). Two hundred and eighteen (42.4 %) female and 6 (42.9 %) male skaters had suffered from acute injuries during their synchronized skating career. As some skaters had suffered from more than one injury, the total number of acute injuries in females was 398 and in males 14. In female skaters 19.8 % of acute injuries were head injuries, 7.1 % trunk, 33.2 % upper, and 39.9 % lower extremity injuries. In male skaters 14.3 % were head injuries, 28.6 % upper, and 57.1 % lower extremity injuries, with no report of trunk injuries. Sixty-nine female and 2 male skaters had low back problems and 112 female and 2 male skaters had one or more overuse syndromes during their skating career. Of 155 overuse injuries in female skaters, 102 (65.8 %) occurred during their figure skating career, while 53 injuries (34.2 %) only occurred when they skated in synchronized skating teams. In male skaters, out of 5 overuse injuries, 4 (80 %) occurred in their figure skating career, while 1 (20 %) occurred during their synchronized skating career. Out of the total of 412 injuries, 338 (82 %) occurred during on-ice practice, while 74 (18 %) happened during off-ice training. Ninety-one (26.9 %) acute injures occurred while practicing individual elements, and 247 (73.1 %) on-ice injuries occurred while practicing different team elements. We conclude that injuries in synchronized skating should be of medical concern due to an increasing number of acute injuries, especially

  20. Instructor's guide : - synchronized skating school

    OpenAIRE

    Mokkila, Eveliina

    2011-01-01

    The starting point to the Instructor’s guide for synchronized skating school was the situation that Turun Riennon Taitoluistelu figure skating club constantly struggles to get enough skaters to the Beginner team in synchronized skating. The guidebook was written to guide the skating school instructors towards providing more synchronized skating teaching in their lessons. As a result from introducing synchronized skating more in the skating school, it is expected to have more children conti...

  1. Synchronizing Strategies under Partial Observability

    DEFF Research Database (Denmark)

    Larsen, Kim Guldstrand; Laursen, Simon; Srba, Jiri

    2014-01-01

    Embedded devices usually share only partial information about their current configurations as the communication bandwidth can be restricted. Despite this, we may wish to bring a failed device into a given predetermined configuration. This problem, also known as resetting or synchronizing words, has...... been intensively studied for systems that do not provide any information about their configurations. In order to capture more general scenarios, we extend the existing theory of synchronizing words to synchronizing strategies, and study the synchronization, short-synchronization and subset...

  2. Synchronous message-based communication for distributed heterogeneous systems

    International Nuclear Information System (INIS)

    Wilkinson, N.; Dohan, D.

    1992-01-01

    The use of a synchronous, message-based real-time operating system (Unison) as the basis of transparent interprocess and inter-processor communication over VME-bus is described. The implementation of a synchronous, message-based protocol for network communication between heterogeneous systems is discussed. In particular, the design and implementation of a message-based session layer over a virtual circuit transport layer protocol using UDP/IP is described. Inter-process communication is achieved via a message-based semantic which is portable by virtue of its ease of implementation in other operating system environments. Protocol performance for network communication among heterogeneous architecture is presented, including VMS, Unix, Mach and Unison. (author)

  3. Time Error Analysis of SOE System Using Network Time Protocol

    International Nuclear Information System (INIS)

    Keum, Jong Yong; Park, Geun Ok; Park, Heui Youn

    2005-01-01

    To find the accuracy of time in the fully digitalized SOE (Sequence of Events) system, we used a formal specification of the Network Time Protocol (NTP) Version 3, which is used to synchronize time keeping among a set of distributed computers. Through constructing a simple experimental environments and experimenting internet time synchronization, we analyzed the time errors of local clocks of SOE system synchronized with a time server via computer networks

  4. Estrous cycle influences the expression of neuronal nitric oxide synthase in the hypothalamus and limbic system of female mice

    Directory of Open Access Journals (Sweden)

    Viglietti-Panzica Carla

    2009-07-01

    Full Text Available Abstract Background Nitric oxide plays an important role in the regulation of male and female sexual behavior in rodents, and the expression of the nitric oxide synthase (NOS is influenced by testosterone in the male rat, and by estrogens in the female. We have here quantitatively investigated the distribution of nNOS immunoreactive (ir neurons in the limbic hypothalamic region of intact female mice sacrificed during different phases of estrous cycle. Results Changes were observed in the medial preoptic area (MPA (significantly higher number in estrus and in the arcuate nucleus (Arc (significantly higher number in proestrus. In the ventrolateral part of the ventromedial nucleus (VMHvl and in the bed nucleus of the stria terminalis (BST no significant changes have been observed. In addition, by comparing males and females, we observed a stable sex dimorphism (males have a higher number of nNOS-ir cells in comparison to almost all the different phases of the estrous cycle in the VMHvl and in the BST (when considering only the less intensely stained elements. In the MPA and in the Arc sex differences were detected only comparing some phases of the cycle. Conclusion These data demonstrate that, in mice, the expression of nNOS in some hypothalamic regions involved in the control of reproduction and characterized by a large number of estrogen receptors is under the control of gonadal hormones and may vary according to the rapid variations of hormonal levels that take place during the estrous cycle.

  5. Male goat vocalizations stimulate the estrous behavior and LH secretion in anestrous goats that have been previously exposed to bucks.

    Science.gov (United States)

    Delgadillo, José Alberto; Vielma, Jesús; Hernandez, Horacio; Flores, José Alfredo; Duarte, Gerardo; Fernández, Ilda Graciela; Keller, Matthieu; Gelez, Hélène

    2012-09-01

    We investigated whether live vocalizations emitted by bucks interacting with anestrous females stimulate secretion of LH, estrous behavior and ovulation in anestrous goats. In experiment 1, bucks rendered sexually active by exposure to long days followed by natural photoperiod were exposed in a light-proof-building to five anestrous females. Buck vocalizations were reproduced through a microphone-amplifier-loudspeaker system to an open pen where one group of goats (n=6) was exposed for 10 days to these live vocalizations. Another group of females (n=6) was isolated from males and vocalizations. The proportion of goats displaying estrous behavior was significantly higher in females exposed to buck vocalizations than in females isolated from males. The proportion of goats that ovulated did not differ between the 2 groups (exposed to males versus isolated). In experiment 2, female goats that either had previous contact with males (n=7), or no previous contact with males (n=7) were exposed to live buck vocalizations, reproduced as described in experiment 1, for 5 days. The number and amplitude of LH pulses did not differ between groups before exposition to buck vocalizations. Five days of exposure to male vocalizations significantly increased LH pulsatility only in females that had previous contact with males, while LH pulse amplitude was not modified. We concluded that live buck vocalizations can stimulate estrous behavior and LH secretion in goats if they have had previous contact with bucks. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Synchronizing XPath Views

    DEFF Research Database (Denmark)

    Pedersen, Dennis; Pedersen, Torben Bach

    2004-01-01

    The increasing availability of XML-based data sources, e.g., for publishing data on the WWW, means that more and more applications (data consumers) rely on accessing and using XML data. Typically, the access is achieved by defining views over the XML data, and accessing data through these views....... However, the XML data sources are often independent of the data consumers and may change their schemas without notification, invalidating the XML views defined by the data consumers. This requires the view definitions to be updated to reflect the new structure of the data sources, a process termed view...... synchronization. XPath is the most commonly used language for retrieving parts of XML documents, and is thus an important cornerstone for XML view definitions. This paper presents techniques for discovering schema changes in XML data sources and synchronizing XPath-based views to reflect these schema changes...

  7. LHC synchronization test successful

    CERN Multimedia

    The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.Picture:http://lhc-injection-test.web.cern.ch/lhc-injection-test/

  8. A method of high accuracy clock synchronization by frequency following with VCXO

    International Nuclear Information System (INIS)

    Ma Yichao; Wu Jie; Zhang Jie; Song Hongzhi; Kong Yang

    2011-01-01

    In this paper, the principle of the synchronous protocol of the IEEE1588 is analyzed, and the factors that affect the accuracy of synchronization is summarized. Through the hardware timer in a microcontroller, we give the exactly the time when a package is sent or received. So synchronization of the distributed clocks can reach 1 μs in this way. Another method to improve precision of the synchronization is to replace the traditional fixed frequency crystal of the slave device, which needs to follow up the master clock, by an adjustable VCXO. So it is possible to fine tune the frequency of the distributed clocks, and reduce the drift of clock, which shows great benefit for the clock synchronization. A test measurement shows the synchronization of distribute clocks can be better than 10 ns using this method, which is more accurate than the method realized by software. (authors)

  9. A Cryptographic Moving-Knife Cake-Cutting Protocol

    Directory of Open Access Journals (Sweden)

    Yoshifumi Manabe

    2012-02-01

    Full Text Available This paper proposes a cake-cutting protocol using cryptography when the cake is a heterogeneous good that is represented by an interval on a real line. Although the Dubins-Spanier moving-knife protocol with one knife achieves simple fairness, all players must execute the protocol synchronously. Thus, the protocol cannot be executed on asynchronous networks such as the Internet. We show that the moving-knife protocol can be executed asynchronously by a discrete protocol using a secure auction protocol. The number of cuts is n-1 where n is the number of players, which is the minimum.

  10. A Novel Method of Clock Synchronization in Distributed Systems

    Science.gov (United States)

    Li, Gun; Niu, Meng-jie; Chai, Yang-shun; Chen, Xin; Ren, Yan-qiu

    2017-04-01

    Time synchronization plays an important role in the spacecraft formation flight and constellation autonomous navigation, etc. For the application of clock synchronization in a network system, it is not always true that all the observed nodes in the network are interconnected, therefore, it is difficult to achieve the high-precision time synchronization of a network system in the condition that a certain node can only obtain the measurement information of clock from a single neighboring node, but cannot obtain it from other nodes. Aiming at this problem, a novel method of high-precision time synchronization in a network system is proposed. In this paper, each clock is regarded as a node in the network system, and based on the definition of different topological structures of a distributed system, the three control algorithms of time synchronization under the following three cases are designed: without a master clock (reference clock), with a master clock (reference clock), and with a fixed communication delay in the network system. And the validity of the designed clock synchronization protocol is proved by both stability analysis and numerical simulation.

  11. A new approach for global synchronization in hierarchical scheduled real-time systems

    NARCIS (Netherlands)

    Behnam, M.; Nolte, T.; Bril, R.J.

    2009-01-01

    We present our ongoing work to improve an existing synchronization protocol SIRAP for hierarchically scheduled real-time systems. A less pessimistic schedulability analysis is presented which can make the SIRAP protocol more efficient in terms of calculated CPU resource needs. In addition and for

  12. Whole-body metabolism varies across the estrous cycle in Sprague-Dawley rats.

    Science.gov (United States)

    Parker, G C; McKee, M E; Bishop, C; Coscina, D V

    2001-10-01

    Food intake in rats and other mammals is lowest at estrus and highest at diestrus. While much is known about the effects of different estrous phases on energy intake, as well as some of the metabolic effects the associated hormones exert, little has been reported about changes in whole-body metabolism that accompany those phases. This study investigates how energy expenditure (EE) and respiratory quotient (RQ) vary in intact female Sprague-Dawley rats (n=12) tested mid-light cycle over 2 h on days associated with estrus vs. diestrus. Rats showed small but reliable decreases in body weight on days associated with estrus, but not diestrus. EE was significantly increased by approximately 21% on the day associated with estrus compared to diestrus. At the same time, RQ was significantly decreased by approximately 7% on the day associated with estrus, indicating a relative shift to fat over carbohydrate as the energy substrate to support energetic needs. Future investigations of ingestive processes can integrate the present findings to investigate how gender differences in feeding and metabolism contribute to regulatory behaviors.

  13. Exploiting Schemas in Data Synchronization

    DEFF Research Database (Denmark)

    Foster, J. Nathan; Greenwald, Michael B.; Kirkegaard, Christian

    2005-01-01

    Increased reliance on optimistic data replication has led to burgeoning interest in tools and frameworks for disconnected updates to replicated data.We have implemented a generic synchronization framework, called HARMONY, that can be used to build state-based synchronizers for a wide variety...... of tree-structureddata formats. A novel feature of this framework is that the synchronization process - in particular, the recognition of conflicts - is driven by the schema of the structures being synchronized.We formalize HARMONY's synchronization algorithm, state a simple and intuitive specification......, and illustrate, using simple address books as a case study, how it can be used to synchronize trees representing a variety of specific forms of applicationdata, including sets, records, tuples, and relations....

  14. Content-based intermedia synchronization

    Science.gov (United States)

    Oh, Dong-Young; Sampath-Kumar, Srihari; Rangan, P. Venkat

    1995-03-01

    Inter-media synchronization methods developed until now have been based on syntactic timestamping of video frames and audio samples. These methods are not fully appropriate for the synchronization of multimedia objects which may have to be accessed individually by their contents, e.g. content-base data retrieval. We propose a content-based multimedia synchronization scheme in which a media stream is viewed as hierarchial composition of smaller objects which are logically structured based on the contents, and the synchronization is achieved by deriving temporal relations among logical units of media object. content-based synchronization offers several advantages such as, elimination of the need for time stamping, freedom from limitations of jitter, synchronization of independently captured media objects in video editing, and compensation for inherent asynchronies in capture times of video and audio.

  15. Finite-Time and Fixed-Time Cluster Synchronization With or Without Pinning Control.

    Science.gov (United States)

    Liu, Xiwei; Chen, Tianping

    2018-01-01

    In this paper, the finite-time and fixed-time cluster synchronization problem for complex networks with or without pinning control are discussed. Finite-time (or fixed-time) synchronization has been a hot topic in recent years, which means that the network can achieve synchronization in finite-time, and the settling time depends on the initial values for finite-time synchronization (or the settling time is bounded by a constant for any initial values for fixed-time synchronization). To realize the finite-time and fixed-time cluster synchronization, some simple distributed protocols with or without pinning control are designed and the effectiveness is rigorously proved. Several sufficient criteria are also obtained to clarify the effects of coupling terms for finite-time and fixed-time cluster synchronization. Especially, when the cluster number is one, the cluster synchronization becomes the complete synchronization problem; when the network has only one node, the coupling term between nodes will disappear, and the synchronization problem becomes the simplest master-slave case, which also includes the stability problem for nonlinear systems like neural networks. All these cases are also discussed. Finally, numerical simulations are presented to demonstrate the correctness of obtained theoretical results.

  16. Physical Layer Ethernet Clock Synchronization

    Science.gov (United States)

    2010-11-01

    42 nd Annual Precise Time and Time Interval (PTTI) Meeting 77 PHYSICAL LAYER ETHERNET CLOCK SYNCHRONIZATION Reinhard Exel, Georg...oeaw.ac.at Nikolaus Kerö Oregano Systems, Mohsgasse 1, 1030 Wien, Austria E-mail: nikolaus.keroe@oregano.at Abstract Clock synchronization ...is a service widely used in distributed networks to coordinate data acquisition and actions. As the requirement to achieve tighter synchronization

  17. The Synchronic Fallacy

    DEFF Research Database (Denmark)

    Hansen, Erik W.

    , to exist, in order to underline the cognitive basis of man's (comprehension of) existence. A theory of history (existence) is set up on the basis of the traditional dualistic sign function, and the traditional sound-law concept and sound development are reinterpreted in terms of the theory's system...... of definitions. Historical linguistics ('change') is not dependent on an arbitrary synchronic theory. The two language universals polysemy and synonymy are reinterpreted and defined in accordance with the advanced definitions. Louis Hjelmslev's glossematic theory is the general horizon of the argument...

  18. Control of synchronous motors

    CERN Document Server

    Louis, Jean-Paul

    2013-01-01

    Synchronous motors are indubitably the most effective device to drive industrial production systems and robots with precision and rapidity. Their control law is thus critical for combining at the same time high productivity to reduced energy consummation. As far as possible, the control algorithms must exploit the properties of these actuators. Therefore, this work draws on well adapted models resulting from the Park's transformation, for both the most traditional machines with sinusoidal field distribution and for machines with non-sinusoidal field distribution which are more and more used in

  19. Psychic energy and synchronicity.

    Science.gov (United States)

    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. © 2014, The Society of Analytical Psychology.

  20. Laser Megajoule synchronization system

    International Nuclear Information System (INIS)

    Luttmann, M.; Pastor, J.F; Drouet, V.; Prat, M.; Raimbourg, J.; Adolf, A.

    2011-01-01

    This paper describes the synchronisation system under development on the Laser Megajoule (LMJ) in order to synchronize the laser quads on the target to better than 40 ps rms. Our architecture is based on a Timing System (TS) which delivers trigger signals with jitter down to 15 ps rms coupled with an ultra precision timing system with 5 ps rms jitter. In addition to TS, a sensor placed at the target chamber center measures the arrival times of the 3 omega nano joule laser pulses generated by front end shots. (authors)

  1. The expression pattern of microRNAs in granulosa cells of subordinate and dominant follicles during the early luteal phase of the bovine estrous cycle.

    Directory of Open Access Journals (Sweden)

    Dessie Salilew-Wondim

    Full Text Available This study aimed to investigate the miRNA expression patterns in granulosa cells of subordinate (SF and dominant follicle (DF during the early luteal phase of the bovine estrous cycle. For this, miRNA enriched total RNA isolated from granulosa cells of SF and DF obtained from heifers slaughtered at day 3 and day 7 of the estrous cycle was used for miRNAs deep sequencing. The results revealed that including 17 candidate novel miRNAs, several known miRNAs (n = 291-318 were detected in SF and DF at days 3 and 7 of the estrous cycle of which 244 miRNAs were common to all follicle groups. The let-7 families, bta-miR-10b, bta-miR-26a, bta-miR-99b and bta-miR-27b were among abundantly expressed miRNAs in both SF and DF at both days of the estrous cycle. Further analysis revealed that the expression patterns of 16 miRNAs including bta-miR-449a, bta-miR-449c and bta-miR-222 were differentially expressed between the granulosa cells of SF and DF at day 3 of the estrous cycle. However, at day 7 of the estrous cycle, 108 miRNAs including bta-miR-409a, bta-miR-383 and bta-miR-184 were differentially expressed between the two groups of granulosa cell revealing the presence of distinct miRNA expression profile changes between the two follicular stages at day 7 than day 3 of the estrous cycle. In addition, unlike the SF, marked temporal miRNA expression dynamics was observed in DF groups between day 3 and 7 of the estrous cycle. Target gene prediction and pathway analysis revealed that major signaling associated with follicular development including Wnt signaling, TGF-beta signaling, oocyte meiosis and GnRH signaling were affected by differentially expressed miRNAs. Thus, this study highlights the miRNA expression patterns of granulosa cells in subordinate and dominant follicles that could be associated with follicular recruitment, selection and dominance during the early luteal phase of the bovine estrous cycle.

  2. Accelerated testing for synchronous orbits

    Science.gov (United States)

    Mcdermott, P.

    1981-01-01

    Degradation of batteries during synchronous orbits is analyzed. Discharge and recharge rates are evaluated. The functional relationship between charge rate and degradation is mathematically determined.

  3. Medical issues in synchronized skating.

    Science.gov (United States)

    Abbott, Kristin; Hecht, Suzanne

    2013-01-01

    Synchronized skating is a unique sport of team skating and currently represents the largest competitive discipline in U.S. Figure Skating. Synchronized skating allows skaters to compete as part of a team with opportunities to represent their country in international competitions. As the popularity of the sport continues to grow, more of these athletes will present to sports medicine clinics with injuries and illnesses related to participation in synchronized skating. The purpose of this article is to review the common injuries and medical conditions affecting synchronized skaters.

  4. Synchronized dynamic dose reconstruction

    International Nuclear Information System (INIS)

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

    2007-01-01

    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

  5. SLAC synchronous condenser

    International Nuclear Information System (INIS)

    Corvin, C.

    1995-06-01

    A synchronous condenser is a synchronous machine that generates reactive power that leads real power by 90 degrees in phase. The leading reactive power generated by the condenser offsets or cancels the normal lagging reactive power consumed by inductive and nonlinear loads at the accelerator complex. The quality of SLAC's utility power is improved with the addition of the condenser. The inertia of the condenser's 35,000 pound rotor damps and smoothes voltage excursions on two 12 kilovolt master substation buses, improving voltage regulation site wide. The condenser absorbs high frequency transients and noise in effect ''scrubbing'' the electric system power at its primary distribution source. In addition, the condenser produces a substantial savings in power costs. Federal and investor owned utilities that supply electric power to SLAC levy a monthly penalty for lagging reactive power delivered to the site. For the 1993 fiscal year this totaled over $285,000 in added costs for the year. By generating leading reactive power on site, thereby reducing total lagging reactive power requirements, a substantial savings in electric utility bills is achieved. Actual savings of $150,000 or more a year are possible depending on experimental operations

  6. FPGA based fast synchronous serial multi-wire links synchronization

    Science.gov (United States)

    Pozniak, Krzysztof T.

    2013-10-01

    The paper debates synchronization method of multi-wire, serial link of constant latency, by means of pseudo-random numbers generators. The solution was designed for various families of FPGA circuits. There were debated synchronization algorithm and functional structure of parameterized transmitter and receiver modules. The modules were realized in VHDL language in a behavioral form.

  7. Time Stamp Synchronization of PEFP Distributed Control Systems

    International Nuclear Information System (INIS)

    Song, Young Gi; An, Eun Mi; Kwon, Hyeok Jung; Cho, Yong Sub

    2010-01-01

    Proton Engineering Frontier Project (PEFP) proton linac consists of several types of control systems, such as soft Input Output Controllers (IOC) and embedded IOC based on Experimental Physics Industrial Control System (EPICS) for each subsection of PEFP facility. One of the important factors is that IOC's time clock is synchronized. The synchronized time and time stamp can be achieved with Network Time Protocol (NTP) and EPICS time stamp record without timing hardware. The requirement of the time accuracy of IOCs is less than 1 second. The main objective of this study is to configure a master clock and produce Process Variable (PV) time stamps using local CPU time synchronized from the master clock. The distributed control systems are attached on PEFP control network

  8. Bioremediation protocols

    National Research Council Canada - National Science Library

    Sheehan, David

    1997-01-01

    ..., .. . . . . .. ,. . . .. . . . . . . . .. . . . . .. . . .. . .. 3 2 Granular Nina Sludge Christiansen, Consortia lndra for Bioremediation, M. Mathrani, and Birgitte K. Ahring . 23 PART II PROTOCOLS...

  9. Food deprivation and leptin prioritize ingestive and sex behavior without affecting estrous cycles in Syrian hamsters.

    Science.gov (United States)

    Schneider, Jill E; Casper, Janelle F; Barisich, Amanda; Schoengold, Candace; Cherry, Sandeep; Surico, Justine; DeBarba, Ashley; Fabris, Frank; Rabold, Elizabeth

    2007-03-01

    Energy consumption is critical for the energetically expensive processes related to reproduction, and thus, mechanisms that increase ingestive behavior are directly linked to reproductive success. Similarly, the mechanisms that inhibit hunger and ingestive behavior might be most adaptive when these mechanisms cause individuals to stop foraging, hoarding and eating in order to find and court potential mates. In the laboratory, ingestive behaviors are typically studied separately from reproductive behaviors even though it is likely that these behaviors evolved under conditions in which both food and mates were available. We examined the choice between paracopulatory and ingestive behaviors in a semi-natural environment in which both food and potential mates were available. Intact female Syrian hamsters showed a high preference for males on days 3 and 4 (day 4 being the day of ovulation and estrous behavior), and a 48-h period of food deprivation significantly decreased preference for sex and increased preference for eating and food hoarding on day 3 in 89% of the hamsters, although none became anestrous. The same period of food deprivation significantly decreased the level of vaginal marking without significant effects on plasma estradiol concentrations. Next, hamsters were either food deprived (FD) or fed ad libitum, and half of each group was treated with vehicle or the adipocyte hormone leptin. The percentage of females with a low preference for sex was significantly greater in the FD compared to the ad libitum-fed groups, and leptin treatment prevented this effect. Metabolic fuels, possibly acting through leptin and other hormones, might influence sensitivity to estradiol or enhance the downstream effects of estradiol, thereby increasing motivation for sex and decreasing the relative motivation to forage, hoard and eat food.

  10. Estrous cycle affects the neurochemical and neurobehavioral profile of carvacrol-treated female rats

    International Nuclear Information System (INIS)

    Trabace, L.; Zotti, M.; Morgese, M.G.; Tucci, P.; Colaianna, M.; Schiavone, S.; Avato, P.; Cuomo, V.

    2011-01-01

    Carvacrol is the major constituent of essential oils from aromatic plants. It showed antimicrobial, anticancer and antioxidant properties. Although it was approved for food use and included in the chemical flavorings list, no indication on its safety has been estimated. Since the use of plant extracts is relatively high among women, aim of this study was to evaluate carvacrol effects on female physiology and endocrine profiles by using female rats in proestrus and diestrus phases. Serotonin and metabolite tissue content in prefrontal cortex and nucleus accumbens, after carvacrol administration (0.15 and 0.45 g/kg p.o.), was measured. Drug effects in behavioral tests for alterations in motor activity, depression, anxiety-related behaviors and endocrine alterations were also investigated. While in proestrus carvacrol reduced serotonin and metabolite levels in both brain areas, no effects were observed in diestrus phase. Only in proestrus phase, carvacrol induced a depressive-like behavior in forced swimming test, without accompanying changes in ambulation. The improvement of performance in FST after subchronic treatment with fluoxetine (20 mg/kg) suggested a specific involvement of serotonergic system. No differences were found across the groups with regard to self-grooming behavior. Moreover, in proestrus phase, carvacrol reduced only estradiol levels without binding hypothalamic estradiol receptors. Our study showed an estrous-stage specific effect of carvacrol on depressive behaviors and endocrine parameters, involving serotonergic system. Given the wide carvacrol use not only as feed additive, but also as cosmetic essence and herbal remedy, our results suggest that an accurate investigation on the effects of its chronic exposure is warranted. - Highlights: → Carvacrol induced a depressive-like phenotype in rats, depending on ovarian cyclicity. → Carvacrol selectively reduced serotonin content in female rats in proestrus phase. → Carvacrol reduced serotonin

  11. Synchronization dynamics of two different dynamical systems

    International Nuclear Information System (INIS)

    Luo, Albert C.J.; Min Fuhong

    2011-01-01

    Highlights: → Synchronization dynamics of two distinct dynamical systems. → Synchronization, de-synchronization and instantaneous synchronization. → A controlled pendulum synchronizing with the Duffing oscillator. → Synchronization invariant set. → Synchronization parameter map. - Abstract: In this paper, synchronization dynamics of two different dynamical systems is investigated through the theory of discontinuous dynamical systems. The necessary and sufficient conditions for the synchronization, de-synchronization and instantaneous synchronization (penetration or grazing) are presented. Using such a synchronization theory, the synchronization of a controlled pendulum with the Duffing oscillator is systematically discussed as a sampled problem, and the corresponding analytical conditions for the synchronization are presented. The synchronization parameter study is carried out for a better understanding of synchronization characteristics of the controlled pendulum and the Duffing oscillator. Finally, the partial and full synchronizations of the controlled pendulum with periodic and chaotic motions are presented to illustrate the analytical conditions. The synchronization of the Duffing oscillator and pendulum are investigated in order to show the usefulness and efficiency of the methodology in this paper. The synchronization invariant domain is obtained. The technique presented in this paper should have a wide spectrum of applications in engineering. For example, this technique can be applied to the maneuvering target tracking, and the others.

  12. Histomorphometric and functional studies of the rat thyroid throughout the estrous cycle Histomorfometria e função tireoidiana no ciclo estral da rata

    Directory of Open Access Journals (Sweden)

    R. Serakides

    2002-02-01

    Full Text Available The influence of the estrous cycle on the thyroid gland was studied. Twenty one five-to-seven-month-old Wistar female rats were divided according to the stage of the estrous cycle in two groups: metaestrus-diestrus and proestrus-estrus. After gross inspection, the thyroids were weighed, sampled, and processed for staining with hematoxilyn-eosin. Seric concentrations of total T4, free T4, total T3, TSH, progesterone, and estradiol were measured. The values of estradiol were significantly higher in the proestrus-estrus stage. However, no significant differences in the plasmatic concentrations of progesterone, free T4, total T4 and TSH throughout the cycle were found. The results of the morphometric study of the thyroid did not indicate any significant differences between the groups. These findings suggest that there is no thyreotrophic effect of estrogen during the estrous cycle in rats.

  13. Business cycle synchronization in Europe

    DEFF Research Database (Denmark)

    Bergman, Ulf Michael; Jonung, Lars

    2011-01-01

    In this paper we study business cycle synchronization in the three Scandinavian countries Denmark, Norway and Sweden prior to, during and after the Scandinavian Currency Union 1873–1913. We find that the degree of synchronization tended to increase during the currency union, thus supporting earlier...

  14. Biologically Inspired Intercellular Slot Synchronization

    Directory of Open Access Journals (Sweden)

    Alexander Tyrrell

    2009-01-01

    Full Text Available The present article develops a decentralized interbase station slot synchronization algorithm suitable for cellular mobile communication systems. The proposed cellular firefly synchronization (CelFSync algorithm is derived from the theory of pulse-coupled oscillators, common to describe synchronization phenomena in biological systems, such as the spontaneous synchronization of fireflies. In order to maintain synchronization among base stations (BSs, even when there is no direct link between adjacent BSs, some selected user terminals (UTs participate in the network synchronization process. Synchronization emerges by exchanging two distinct synchronization words, one transmitted by BSs and the other by active UTs, without any a priori assumption on the initial timing misalignments of BSs and UTs. In large-scale networks with inter-BS site distances up to a few kilometers, propagation delays severely affect the attainable timing accuracy of CelFSync. We show that by an appropriate combination of CelFSync with the timing advance procedure, which aligns uplink transmission of UTs to arrive simultaneously at the BS, a timing accuracy within a fraction of the inter-BS propagation delay is retained.

  15. Introduction to media synchronization (Mediasync)

    NARCIS (Netherlands)

    M.A. Montagud Climent (Mario); P.S. Cesar Garcia (Pablo Santiago); F. Boronat (Fernando); A.J. Jansen (Jack)

    2018-01-01

    textabstractMedia synchronization is a core research area in multimedia systems. This chapter introduces the area by providing key definitions, classifications, and examples. It also discusses the relevance of different types of media synchronization to ensure satisfactory Quality of Experience

  16. Distributed Synchronization in Communication Networks

    Science.gov (United States)

    2018-01-24

    synchronization. Secondly, it is known that identical oscillators with sin() coupling functions are guaranteed to synchronize in phase on a complete...provide sufficient conditions for phase- locking , i.e., convergence to a stable equilibrium almost surely. We additionally find conditions when the

  17. [Synchronous sigmoideum- and caecum volvulus].

    Science.gov (United States)

    Berg, Anna Korsgaard; Perdawood, Sharaf Karim

    2015-09-21

    This case presents a synchronous sigmoid- and caecum volvulus in a 69-year old man with Parkinson's disease, hypertension and previous history of colonic volvulus. On admission the patient had abdominal pain, nausea, vomiting and constipation. The CT scan showed a sigmoid volvulus with a dilated caecum. The synchronous sigmoideum- and caecum volvulus was diagnosed intraoperatively. Total colectomy and ileostomy was performed.

  18. Digital synchronization and communication techniques

    Science.gov (United States)

    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.

  19. Spatial learning of female mice: a role of the mineralocorticoid receptor during stress and the estrous cycle

    Directory of Open Access Journals (Sweden)

    Judith P Ter Horst

    2013-05-01

    Full Text Available Corticosterone facilitates behavioral adaptation to a novel experience in a coordinate manner via mineralocorticoid (MR and glucocorticoid receptors (GR. Initially, MR mediates corticosterone action on appraisal processes, risk assessment and behavioral flexibility and then, GR activation promotes consolidation of the new information into memory. Here, we studied on the circular holeboard (CHB the spatial performance of female mice with genetic deletion of MR from the forebrain (MRCaMKCre and their wild type littermates (MRflox/flox mice over the estrous cycle and in response to an acute stressor. The estrous cycle had no effect on the spatial performance of MRflox/flox mice and neither did the acute stressor. However, the MRCaMKCre mutants needed significantly more time to find the exit and made more hole visit errors than the MRflox/flox mice, especially when in proestrus and estrus. In addition, stressed MRCaMKCre mice in estrus had a shorter exit latency than the control estrus MRCaMKCre mice. About 70% of the female MRCaMKCre and MRflox/flox mice used a hippocampal (spatial, extra maze cues rather than the caudate nucleus (stimulate-response, S-R, intra-maze cue strategy and this preference did neither change over the estrous cycle nor after stress. However, stressed MRCaMKCre mice using the S-R strategy needed significantly more time to find the exit hole as compared to the spatial strategy using mice suggesting that the MR could be needed for the stress-induced strategy switch towards a spatial strategy. In conclusion, the results suggest that loss of MR interferes with performance of a spatial task especially when estrogen levels are high suggesting a strong interaction between stress and sex hormones.

  20. Plasma concentration of progesterone and 17β-estradiol of black-rumped agouti (Dasyprocta prymnolopha) during the estrous cycle

    International Nuclear Information System (INIS)

    Guimaraes, Diva Anelie; Ramos, Rosemar Luz; Ohashi, Otavio Mitio; Garcia, Gary Wayne; Gomes Vale, William

    2011-01-01

    The hormonal profile of progesterone and 17 β-estradiol has been evaluated during the estrous cycle of the agouti (Dasyprocta prymnolopha). The hormones were analyzed by radioimmunoassay. Blood samples were collected without sedation twice a week. The concentrations of progesterone were as follows: proestrus 0.78±0.39 ng/ml, estrus 2.83±2.34 ng/ml, metestrus 1.49±1.24 ng/ml, diestrus 3.71±1.48 ng/ml. An increase in the progesterone level was observed during a period of 24 h in the estrous phase. The average 17 β-estradiol levels were as follows: proestrus 2 030.98±961.00 pg/ml, estrus 1 910.56±650.54 pg/ml, metestrus 1 724.83±767.28 pg/ml, diestrus 1 939.94±725.29 pg/ml. The current results have suggested that the progesterone plasma concentration during the estrous cycle in the agouti has a similar increasing, stabilizing and decreasing pattern, as in domestic mammals. Agoutis have two phases of follicular development, as two periods of 17β-estradiol peaks were observed, the first one in the metestrus and the second during the proestrus. Spontaneous ovulation seems to occur after the progesterone peak, indicating that this hormone has been associated with the ovulatory process. A more detailed investigation is needed for better understanding of how progesterone influenced ovulation. Studies on the involvement of progesterone in follicular rupture can be carried out, using steroid biosynthesis inhibitors and observing the effect of this hormone on ovarian activity of proteolytic enzymes in the follicular wall. (author)

  1. Effects of thyroid status on NEI concentration in specific brain areas related to reproduction during the estrous cycle.

    Science.gov (United States)

    Ayala, Carolina; Pennacchio, Gisela Erika; Soaje, Marta; Carreño, Norma Beatriz; Bittencourt, Jakson Cioni; Jahn, Graciela Alma; Celis, María Ester; Valdez, Susana Ruth

    2013-11-01

    We previously showed that short-term hypo- and hyperthyroidism induce changes in neuropeptide glutamic-acid-isoleucine-amide (NEI) concentrations in discrete brain areas in male rats. To investigate the possible effects of hypo- and hyperthyroidism on NEI concentrations mainly in hypothalamic areas related to reproduction and behavior, female rats were sacrificed at different days of the estrous cycle. Circulating luteinizing hormone (LH), estradiol and progesterone concentrations were measured in control, hypothyroid (hypoT, treated with PTU during 7-9 days) and hyperthyroid (hyperT, l-T4 during 4-7 days) animals. Both treatments blunted the LH surge. Hypo- and hyperthyroidism increased estradiol concentrations during proestrus afternoon (P-PM), although hypoT rats showed lower values compared to control during proestrus morning (P-AM). Progesterone levels were higher in all groups at P-PM and in the hyperT during diestrus morning (D2). NEI concentrations were lower in hypoT rats during the estrous cycle except in estrus (E) in the peduncular part of the lateral hypothalamus (PLH). They were also reduced by both treatments in the perifornical part of the lateral hypothalamus (PeFLH) during P-PM. Hypothyroidism led to higher NEI concentrations during P-PM in the organum vasculosum of the lamina terminalis and anteroventral periventricular nucleus (OVLT+AVPV). The present results indicate that NEI concentration is regulated in a complex manner by hypo- and hyperthyroidism in the different areas studied, suggesting a correlation between NEI values and the variations of gonadal steroid levels during estrous cycle. These changes could be, in part, responsible for the alterations observed in the hypothalamic-pituitary-gonadal axis in these pathologies. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. [Profile of sulphated glycosaminoglycans content in the murine uterus during the different phases of the estrous cycle].

    Science.gov (United States)

    Gomes, Regina Célia Teixeira; Simões, Ricardo Santos; Soares, José Maria; Nader, Helena Bonciani; Simões, Manuel de Jesus; Baracat, Edmund C

    2007-01-01

    Identification and quantitation of sulphated glycosaminoglycans (GAGs) in the uterus of female mice during the estrous cycle. Four groups (n = 10 each) of virgin, 100-day old female mice were assembled according to the estrous cycle phase: proestrus, estrus, metaestrus and diestrus. Samples of the median portion of uterine horns were processed for light microscopy examination (H/E and Alcian blue + PAS). The GAGs were extracted and characterized by agarose gel electrophoresis. Data were analyzed by the unpaired Student's t-test. At light microscopy GAGs appear in all layers of the uterus, especially in the endometrium, between collagen fibers, in the basal membrane and around fibroblasts. Biochemical analyses disclosed presence of dermatan sulphate (DS), chondroitin sulphate (CS and heparan sulphate (HS) during all estral cycle phases. There was no clear electrophoretic separation between DS and CS, thus these two GAGs were considered together (DS+CS) (proestrus = 0.854 +/- 0.192; estrus = 1.073 +/- 0.254; metaestrus = 1.003 +/- 0.255; diestrus = 0.632 +/- 0.443 microg/mg). HS was as follows: proestrus = 0.092 +/- 0.097; estrus = 0.180 +/- 0.141; metaestrus = 0.091 +/- 0.046; diestrus = 0.233 +/- 0.147 microg/mg. The uterine content of DS+CS peaked at estrus (estrogenic action) and that of HS at diestrus (progestagen action). Due to a constant turnover process, there are definite alterations in the uterine profile of GAGs content during the estrous cycle in mice, which may be modulated by female sex hormones.

  3. Self-stabilizing Synchronization in Mobile Sensor Networks with Covering

    Science.gov (United States)

    Beauquier, Joffroy; Burman, Janna

    Synchronization is widely considered as an important service in distributed systems which may simplify protocol design. Phase clock is a general synchronization tool that provides a form of a logical time. This paper presents a self-stabilizing (a tolerating state-corrupting transient faults) phase clock algorithm suited to the model of population protocols with covering. This model has been proposed recently for sensor networks with a very large, possibly unknown number of anonymous mobile agents having small memory. Agents interact in pairs in an asynchronous way subject to the constraints expressed in terms of the cover times of agents. The cover time expresses the "frequency" of an agent to communicate with all the others and abstracts agent's communication characteristics (e.g. moving speed/patterns, transmitting/receiving capabilities). We show that a phase clock is impossible in the model with only constant-state agents. Hence, we assume an existence of resource-unlimited agent - the base station.

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

    Science.gov (United States)

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

    1979-01-01

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

  5. ObliviSync: Practical Oblivious File Backup and Synchronization

    OpenAIRE

    Aviv, Adam J.; Choi, Seung Geol; Mayberry, Travis; Roche, Daniel S.

    2016-01-01

    Oblivious RAM (ORAM) protocols are powerful techniques that hide a client's data as well as access patterns from untrusted service providers. We present an oblivious cloud storage system, ObliviSync, that specifically targets one of the most widely-used personal cloud storage paradigms: synchronization and backup services, popular examples of which are Dropbox, iCloud Drive, and Google Drive. This setting provides a unique opportunity because the above privacy properties can be achieved with ...

  6. Synchronization challenges in packet-based Cloud-RAN fronthaul for mobile networks

    DEFF Research Database (Denmark)

    Checko, Aleksandra; Juul, Anders Christian; Christiansen, Henrik Lehrmann

    2015-01-01

    In this paper, we look at reusing existing packet-based network (e.g. Ethernet) to possibly decrease deployment costs of fronthaul Cloud Radio Access Network (C-RAN) network and cost of Baseband Unit (BBU) resources. The challenge of this solution is that it requires mobile traffic (until now...... transmitted over synchronous protocols) to traverse the asynchronous Ethernet without losing synchronization. We analyze synchronization requirements of mobile networks and present an overview of solutions that fulfill them in traditional mobile networks. Then we elaborate on challenges that packet-based...... fronthaul imposes. We analyze possible contributions to frequency and phase error. We verify the feasibility of using the IEEE 1588v2 also know as Precision Time Protocol (PTP) for providing accurate phase and frequency synchronization. The study is based on simulations made in OPNET modeler. Thereby we...

  7. Bouncing Ball with a Uniformly Varying Velocity in a Metronome Synchronization Task.

    Science.gov (United States)

    Huang, Yingyu; Gu, Li; Yang, Junkai; Wu, Xiang

    2017-09-21

    Sensorimotor synchronization (SMS), a fundamental human ability to coordinate movements with external rhythms, has long been thought to be modality specific. In the canonical metronome synchronization task that requires tapping a finger along with an isochronous sequence, a well-established finding is that synchronization is much more stable to an auditory sequence consisting of auditory tones than to a visual sequence consisting of visual flashes. However, recent studies have shown that periodically moving visual stimuli can substantially improve synchronization compared with visual flashes. In particular, synchronization of a visual bouncing ball that has a uniformly varying velocity was found to be not less stable than synchronization of auditory tones. Here, the current protocol describes the application of the bouncing ball with a uniformly varying velocity in a metronome synchronization task. The usage of the bouncing ball in sequences with different inter-onset intervals (IOI) is included. The representative results illustrate synchronization performance of the bouncing ball, as compared with the performances of auditory tones and visual flashes. Given its comparable synchronization performance to that of auditory tones, the bouncing ball is of particular importance for addressing the current research topic of whether modality-specific mechanisms underlay SMS.

  8. Synchronization of S phase in Schizosaccharomyces pombe cells by transient exposure to M-factor pheromone

    DEFF Research Database (Denmark)

    Nielsen, Olaf

    2016-01-01

    A well-characterized S phase, a unicellular lifestyle, and a plethora of mutations in key components of DNA metabolism make fission yeast a particularly attractive system in which to study DNA replication. However, synchronization of passage through a normal S phase has proved challenging. This p....... This protocol describes how combining nitrogen starvation with M-factor mating pheromone treatment presents a highly effective method for synchronizing passage through an ostensibly normal S phase....

  9. Generalized synchronization between chimera states

    Science.gov (United States)

    Andrzejak, Ralph G.; Ruzzene, Giulia; Malvestio, Irene

    2017-05-01

    Networks of coupled oscillators in chimera states are characterized by an intriguing interplay of synchronous and asynchronous motion. While chimera states were initially discovered in mathematical model systems, there is growing experimental and conceptual evidence that they manifest themselves also in natural and man-made networks. In real-world systems, however, synchronization and desynchronization are not only important within individual networks but also across different interacting networks. It is therefore essential to investigate if chimera states can be synchronized across networks. To address this open problem, we use the classical setting of ring networks of non-locally coupled identical phase oscillators. We apply diffusive drive-response couplings between pairs of such networks that individually show chimera states when there is no coupling between them. The drive and response networks are either identical or they differ by a variable mismatch in their phase lag parameters. In both cases, already for weak couplings, the coherent domain of the response network aligns its position to the one of the driver networks. For identical networks, a sufficiently strong coupling leads to identical synchronization between the drive and response. For non-identical networks, we use the auxiliary system approach to demonstrate that generalized synchronization is established instead. In this case, the response network continues to show a chimera dynamics which however remains distinct from the one of the driver. Hence, segregated synchronized and desynchronized domains in individual networks congregate in generalized synchronization across networks.

  10. Protocol synchronization of estrus and ovulation in sheep

    OpenAIRE

    Almeida, Marcelo Ferreira de

    2009-01-01

    Objetivou-se testar o protocolo hormonal para IATF (inseminação artificial em tempo fixo) com progesterona por 6 dias aplicando-se eCG (gonadotrofina Coriônica Eqüina) ou BE (Benzoato de Estradiol) e indução de estros utilizando-se: esponjas vaginais impregnadas com MAP (acetato de medroxiprogesterona) por 6, 9 e 14 dias ou dose única de PGF2a ou efeito macho. Experimento 1: No D0 cada ovelha (n=31) recebeu CIDR sendo divididas aleatoriamente em 3 grupos: G-C (controle) CIDR por 9 dias e na r...

  11. SAL and PVS Model of TTEthernet Synchronization Protocol

    Data.gov (United States)

    National Aeronautics and Space Administration — Timed-Triggered Ethernet (or TTEthernet)is a communication infrastructure that enables the use of Ethernet in real-time, distributed systems. TTEthernet is...

  12. Effect of different oestrus synchronizations protocols on the ...

    African Journals Online (AJOL)

    internal-drug-release-device (CIDR) and equine chorionic gonadotropin (eCG) on reproductive efficiency of Dammar ewes in winter. Data of forty-one ewes were divided into two groups; for long CIDR treatment (12 days, LT, n=25) and for short ...

  13. Three types of generalized synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Yang Junzhong [School of Science, Beijing University of Posts and Telecomunications, Beijing 100876 (China)]. E-mail: jzyang@bupt.edu.cn; Hu Gang [China Center for Advanced Science and Technology (CCAST) (World Laboratory), PO Box 8730, Beijing 100080 (China) and Department of Physics, Beijing Normal University, Beijing 100875 (China)]. E-mail: ganghu@bnu.edu.cn

    2007-02-05

    The roles played by drive and response systems on generalized chaos synchronization (GS) are studied. And the generalized synchronization is classified, based on these roles, to three distinctive types: the passive GS which is mainly determined by the response system and insensitive to the driving signal; the resonant GS where phase synchronization between the drive and response systems is preceding GS; and the interacting GS where both the drive and response have influences on the status of GS. The features of these GS types and the possible changes from one types to others are investigated.

  14. Three types of generalized synchronization

    International Nuclear Information System (INIS)

    Yang Junzhong; Hu Gang

    2007-01-01

    The roles played by drive and response systems on generalized chaos synchronization (GS) are studied. And the generalized synchronization is classified, based on these roles, to three distinctive types: the passive GS which is mainly determined by the response system and insensitive to the driving signal; the resonant GS where phase synchronization between the drive and response systems is preceding GS; and the interacting GS where both the drive and response have influences on the status of GS. The features of these GS types and the possible changes from one types to others are investigated

  15. The vaginal microbiome is stable in prepubertal and sexually mature Ellegaard Göttingen Minipigs throughout an estrous cycle.

    Science.gov (United States)

    Lorenzen, Emma; Kudirkiene, Egle; Gutman, Nicole; Grossi, Anette Blak; Agerholm, Jørgen Steen; Erneholm, Karin; Skytte, Christina; Dalgaard, Marlene Danner; Bojesen, Anders Miki

    2015-10-28

    Although the pig has been introduced as an advanced animal model of genital tract infections in women, almost no knowledge exists on the porcine vaginal microbiota, especially in barrier-raised Göttingen Minipigs. In women, the vaginal microbiota plays a crucial role for a healthy vaginal environment and the fate of sexually transmitted infections such as Chlamydia trachomatis infections. Therefore, knowledge on the vaginal microbiota is urgently needed for the minipig model. The aim of this study was to characterize the microbiota of the anterior vagina by 16 s rRNA gene sequencing in prepubertal and sexually mature Göttingen Minipigs during an estrous cycle. The dominating phyla in the vaginal microbiota consisted of Firmicutes, Proteobacteria, Actinobacteria, Bacteriodetes and Tenericutes. The most abundant bacterial families were Enterobacteriaceae, unclassified families from Gammaproteobacteria, Clostridiales Family XI Incertae Sedis, Paenibacillaceae, Lactobacillaceae, Ruminococcaceae and Syntrophaceae. We found a higher abundance of Lactobacillaceae in the prepubertal Göttingen Minipigs compared to sexually mature non-pregnant Göttingen Minipigs. However, correlation tests and diversity parameters revealed a very stable vaginal microbiota in the Göttingen Minipigs, both before and after sexual maturity and on different days throughout an estrous cycle. The vaginal microbiota in Göttingen Minipigs was not dominated by lactobacilli, as it is in women and according to our results the minipig vaginal microbiota is very stable, in opposite to women. These differences should be considered when using the minipig as a model of the genital tract in women.

  16. Comparative Studies of Estrous Synchronization, Ovulation Induction, Luteal Function and Embryo Cryopreservation in Domestic Sheep and Application to Related Nondomestic Ungulate Species

    Science.gov (United States)

    1989-12-20

    swine vesicular disease virus (SVDV, Singh, 1987) from porcine embryos, which also appear permeable to a variety of viruses (porcine parvovirus ...for follicular maturation. In contrast, when MAP pessaries are used, the removal of the sponge results in a more attenuated decline in circulating...porcine parvovirus on development of fertilized pig eggs in vitro. Br. Vet. J. 135: 249-254, 1979. Wright, J.M. Non-surgical embryo transfer in

  17. Noncoherent Symbol Synchronization Techniques

    Science.gov (United States)

    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.

  18. Cross-spectrum symbol synchronization

    Science.gov (United States)

    Mccallister, R. D.; Simon, M. K.

    1981-01-01

    A popular method of symbol synchronization exploits one aspect of generalized harmonic analysis, normally referred to as the cross-spectrum. Utilizing nonlinear techniques, the input symbol energy is effectively concentrated onto multiples of the symbol clock frequency, facilitating application of conventional phase lock synchronization techniques. A general treatment of the cross-spectrum technique is developed and shown to be applicable across a broad class of symbol modulation formats. An important specific symbol synchronization application is then treated, focusing the general development to provide both insight and quantitative measure of the performance impact associated with variation in these key synchronization parameters: symbol modulation format, symbol transition probability, symbol energy to noise density ratio, and symbol rate to filter bandwidth ratio.

  19. Principles of synchronous digital hierarchy

    CERN Document Server

    Jain, Rajesh Kumar

    2012-01-01

    The book presents the current standards of digital multiplexing, called synchronous digital hierarchy, including analog multiplexing technologies. It is aimed at telecommunication professionals who want to develop an understanding of digital multiplexing and synchronous digital hierarchy in particular and the functioning of practical telecommunication systems in general. The text includes all relevant fundamentals and provides a handy reference for problem solving or defining operations and maintenance strategies. The author covers digital conversion and TDM principles, line coding and digital

  20. Synchronous Half-Wave Rectifier

    Science.gov (United States)

    Rippel, Wally E.

    1989-01-01

    Synchronous rectifying circuit behaves like diode having unusually low voltage drop during forward-voltage half cycles. Circuit particularly useful in power supplies with potentials of 5 Vdc or less, where normal forward-voltage drops in ordinary diodes unacceptably large. Fabricated as monolithic assembly or as hybrid. Synchronous half-wave rectifier includes active circuits to attain low forward voltage drop and high rectification efficiency.

  1. Hybrid synchronization of hyperchaotic Lu system

    Indian Academy of Sciences (India)

    In this paper, we study the hybrid synchronization between two identical hyperchaotic Lu systems. Hybrid synchronization of hyperchaotic Lu system is achieved through synchronization of two pairs of states and anti-synchronization of the other two pairs of states. Active controls are designed to achieve hybrid ...

  2. Estrous cycle-dependent neural plasticity in the caudal brainstem in the female golden hamster : Ultrastructural and immunocytochemical studies of axo-dendritic relationships and dynamic remodeling

    NARCIS (Netherlands)

    Gerrits, P. O.; Kortekaas, R.; Veening, J. G.; de Weerd, H.; Algra, A.; Mouton, L. J.; van der Want, J. J. L.

    2008-01-01

    During the short four-day estrous cycle of the female hamster various behavioral (lordosis, vocalization and aggression) and autonomic adaptations occur. Presumably, these changes are under ovarian control. Recently, we described a distinct estrogen receptor-alpha immunoreactive (ER-alpha-IR) cell

  3. Estrous cycle-dependent neural plasticity in the caudal brainstem in the female golden hamster: ultrastructural and immunocytochemical studies of axo-dendritic relationships and dynamic remodeling.

    NARCIS (Netherlands)

    Gerrits, P.O.; Kortekaas, R.; Veening, J.G.; Weerd, H. de; Algra, A.; Mouton, L.J.; Want, J.J. van der

    2008-01-01

    During the short four-day estrous cycle of the female hamster various behavioral (lordosis, vocalization and aggression) and autonomic adaptations occur. Presumably, these changes are under ovarian control. Recently, we described a distinct estrogen receptor-alpha immunoreactive (ER-alpha-IR) cell

  4. Estrous cycle dependent changes in expression and distribution of Fas, Fas ligand, Bcl-2, Bax, and pro- and active caspase-3 in the rat ovary

    NARCIS (Netherlands)

    Slot, K.A.; Voorendt, M.; Boer-Brouwer, de M.; Vugt, van H.H.; Teerds, K.J.

    2006-01-01

    In the present investigation, the localization of proteins involved in ovarian apoptosis were studied throughout the estrous cycle in the presence of fluctuating hormone levels. Fas, Fas ligand, Bcl-2, Bax and caspase-3 mRNA expression and proteins were detected in all ovarian tissue extracts,

  5. Synchronization and anti-synchronization coexist in Chen-Lee chaotic systems

    International Nuclear Information System (INIS)

    Chen, J.-H.; Chen, H.-K.; Lin, Y.-K.

    2009-01-01

    This study demonstrates that synchronization and anti-synchronization can coexist in Chen-Lee chaotic systems by direct linear coupling. Based on Lyapunov's direct method, a linear controller was designed to assure that two different types of synchronization can simultaneously be achieved. Further, the hybrid projective synchronization of Chen-Lee chaotic systems was studied using a nonlinear control scheme. The nonlinear controller was designed according to the Lyapunov stability theory to guarantee the hybrid projective synchronization, including synchronization, anti-synchronization, and projective synchronization. Finally, numerical examples are presented in order to illustrate the proposed synchronization approach.

  6. Distribution and quantitative changes in amounts of aquaporin 1, 5 and 9 in the pig uterus during the estrous cycle and early pregnancy

    Directory of Open Access Journals (Sweden)

    Skowronski Mariusz T

    2010-09-01

    Full Text Available Abstract Background Aquaporins (AQPs are a family of membrane channel proteins that facilitate bulk water transport. To date, 11 isoforms of AQPs have been reported to be expressed in the female and male reproductive systems. The purpose of our study was to determine the localization and quantitative changes in the expression of AQP1, 5 and 9 within the pig uterus during different stages of the estrous cycle and early pregnancy. Methods Immunoperoxidase and semi-quantitative immunoblotting techniques were used to examine the distribution and changes in amounts of AQP1, AQP5 and AQP9 in uteral cells of pigs at the early (Days 2-4, middle (10-12, late (14-16 stage of the luteal phase and late (18-20 stage of the follicular phase of the estrous cycle as well as on Days 14-16 and 30-32 of gestation (the onset and the end of implantation process. Results The results demonstrated that AQP1, 5, and 9 were clearly detected in all studied stages of the estrous cycle and pregnancy. AQP1 was localized within uterine blood vessels. In cyclic gilts, endometrial and myometrial expression of AQP1 protein did not change significantly but increased during gestation. AQP5 was localized in smooth muscle cells and uterine epithelial cells. Endometrial expression of AQP5 protein did not change significantly between Days 2-4 and 10-12 of the estrous cycle but increased on Days 14-16 and 18-20 as well as during early pregnancy. Myometrial expression of AQP5 did not differ significantly during the estrous cycle but increased in the pregnancy. The anti-AQP9 antibody labeled uterine epithelial cells of uterus. Endometrial expression of AQP9 did not change significantly between Days 2-4 and 10-12 of the estrous cycle but increased on Days 14-16 and 18-20 as well as during early pregnancy. Conclusions The results suggest that a functional and distinctive collaboration exists among diverse AQPs in water handling during the different uterine phases in the estrous cycle and

  7. Outer Synchronization of Complex Networks by Impulse

    International Nuclear Information System (INIS)

    Sun Wen; Yan Zizong; Chen Shihua; Lü Jinhu

    2011-01-01

    This paper investigates outer synchronization of complex networks, especially, outer complete synchronization and outer anti-synchronization between the driving network and the response network. Employing the impulsive control method which is uncontinuous, simple, efficient, low-cost and easy to implement in practical applications, we obtain some sufficient conditions of outer complete synchronization and outer anti-synchronization between two complex networks. Numerical simulations demonstrate the effectiveness of the proposed impulsive control scheme. (general)

  8. Unidirectional synchronization of Hodgkin-Huxley neurons

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo-Perez, Octavio [Division de Matematicas Aplicadas y Sistemas, Computacionales, IPICYT, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosi (Mexico)]. E-mail: octavio@ipicyt.edu.mx; Femat, Ricardo [Division de Matematicas Aplicadas y Sistemas, Computacionales, IPICYT, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosi (Mexico)]. E-mail: rfemat@ipicyt.edu.mx

    2005-07-01

    Synchronization dynamics of two noiseless Hodgkin-Huxley (HH) neurons under the action of feedback control is studied. The spiking patterns of the action potentials evoked by periodic external modulations attain synchronization states under the feedback action. Numerical simulations for the synchronization dynamics of regular-irregular desynchronized spiking sequences are displayed. The results are discussed in context of generalized synchronization. It is also shown that the HH neurons can be synchronized in face of unmeasured states.

  9. Sexual odor preference and dopamine release in the nucleus accumbens by estrous olfactory cues in sexually naïve and experienced male rats.

    Science.gov (United States)

    Fujiwara, Masaya; Chiba, Atsuhiko

    2018-03-01

    Sexual behavior is a natural reward that activates mesolimbic dopaminergic system. Microdialysis studies have shown that extracellular level of dopamine (DA) in the nucleus accumbens (NAcc) significantly increases during copulation in male rats. The NAcc DA level is also known to be increased during the presentation of a sexually receptive female before mating. This rise in DA was probably associated with sexual motivation elicited by incentive stimuli from the receptive female. These microdialysis studies, however, did not thoroughly investigated if olfactory stimuli from estrous females could significantly increase the extracellular DA in the NAcc of male rats. The present study was designed to examine systematically the relationship between the expression of preference for the olfactory stimuli from estrous females and the effects of these stimuli on the extracellular DA levels in the NAcc measured by in vivo microdialysis in male Long-Evans (LE) rats. We used two types of olfactory stimuli, either airborne odors (volatile stimuli) or soiled bedding (volatile plus nonvolatile stimuli). The sexually experienced male rats, which experienced six ejaculations, significantly preferred both of these olfactory stimuli from estrous females as opposed to males. Exposure to these female olfactory stimuli gradually increased extracellular DA in the NAcc, which reached significantly higher level above baseline during the period following the removal of the stimuli although not during the 15-min stimulus presentation period. The sexually naïve male rats, on the other hand, showed neither preference for olfactory stimuli from estrous females nor increase in the NAcc DA after exposure to these stimuli. These data suggest that in male LE rats olfactory stimuli from estrous females in and of themselves can be conditional cues that induce both incentive motivation and a significant increase in the NAcc DA probably as a result of being associated with sexual reward through

  10. Sensorimotor-correlated discharge recorded from ensembles of cerebellar Purkinje cells varies across the estrous cycle of the rat.

    Science.gov (United States)

    Smith, S S

    1995-09-01

    1. In the present study, locomotor-correlated activity of cerebellar Purkinje cells, recorded using arrays of microwires chronically implanted in adult female rats, was examined across estrous-cycle-associated fluctuations in endogenous sex steroids. Ongoing studies from this laboratory have shown that systemic and local administration of the sex steroid 17 beta-estradiol (E2) augments excitatory responses of cerebellar Purkinje cells to iontophoretically applied glutamate, recorded in vivo from anesthetized female rats. In addition, this steroid potentiated discharge correlated with limb movement. For the present study, extracellular single-unit activity was recorded from as many as 5-11 Purkinje cells simultaneously during treadmill locomotion paradigms. Motor modulation of activity was recorded across three to five consecutive estrous cycles from behaviorally identified cohorts of neurons to test the hypothesis that fluctuations in endogenous sex steroids alter motor modulation of Purkinje cell discharge. 2. Locomotor-associated discharge correlated with treadmill locomotion was increased by a mean of 47% on proestrus, when E2 levels are elevated, relative to diestrus 1. These changes in discharge rate during treadmill locomotion were of significantly greater magnitude than corresponding cyclic alterations in discharge during stationary periods. 3. Correlations with the circadian cycle were also significant, because peak levels of locomotor-associated discharge on the night of behavioral estrus, following elevations in circulating E2, were on average 67% greater than corresponding discharge recorded during the light (proestrus). 4. Alterations in the step cycle were also observed across the estrous cycle: significant decreases in the duration of the flexion phase (by 265 ms, P estrus compared with diestrus. 5. When recorded on estrus, Purkinje cell discharge correlated with the stance or flexion phase of the step cycle was greater in magnitude and preceded the

  11. The effect of cooling management on blood flow to the dominant follicle and estrous cycle length at heat stress.

    Science.gov (United States)

    Honig, Hen; Ofer, Lior; Kaim, Moshe; Jacobi, Shamay; Shinder, Dima; Gershon, Eran

    2016-07-15

    The use of ultrasound imaging for the examination of reproductive organs has contributed substantially to the fertility management of dairy cows around the world. This method has many advantages such as noninvasiveness and immediate availability of information. Adding Doppler index to the ultrasound imaging examination, improved the estimation of blood volume and flow rate to the ovaries in general and to the dominant follicle in particular. The aim of this study was to examine changes in the blood flow to the dominant follicle and compare them to the follicular development throughout the cycle. We further set out to examine the effects of different types of cooling management during the summer on the changes in blood flow to the dominant follicle. For this purpose, 24 Israeli-Holstein dairy cows, under heat stress, were randomly assigned one of two groups: one was exposed to five cooling sessions per day (5CS) and the other to eight cooling sessions per day (8CS). Blood flow to the dominant follicle was measured daily using Doppler index throughout the estrous cycle. No differences in the preovulatory dominant follicle diameter were detected between the two cooling management regimens during the cycle. However, the length of the first follicular wave was significantly longer, whereas the second follicular wave was nonsignificantly shorter in the 5CS group as compared to the 8CS group. In addition, no difference in blood flow was found during the first 18 days of the cycle between the two groups. However, from Day 20 until ovulation a higher rate of blood flow was measured in the ovaries of cows cooled 8 times per day as compared to the 5CS group. No differences in progesterone levels were noted. Finally, the estrous cycle length was shorter in the 8CS group as compared to the 5CS group. Our data suggest that blood flow to the dominant follicle and estrous cycle length is affected by heat stress. Using the appropriate cooling management during heat stress can

  12. A Novel Time Synchronization Method for Dynamic Reconfigurable Bus

    Directory of Open Access Journals (Sweden)

    Zhang Weigong

    2016-01-01

    Full Text Available UM-BUS is a novel dynamically reconfigurable high-speed serial bus for embedded systems. It can achieve fault tolerance by detecting the channel status in real time and reconfigure dynamically at run-time. The bus supports direct interconnections between up to eight master nodes and multiple slave nodes. In order to solve the time synchronization problem among master nodes, this paper proposes a novel time synchronization method, which can meet the requirement of time precision in UM-BUS. In this proposed method, time is firstly broadcasted through time broadcast packets. Then, the transmission delay and time deviations via three handshakes during link self-checking and channel detection can be worked out referring to the IEEE 1588 protocol. Thereby, each node calibrates its own time according to the broadcasted time. The proposed method has been proved to meet the requirement of real-time time synchronization. The experimental results show that the synchronous precision can achieve a bias less than 20 ns.

  13. A synchronous serial bus for multidimensional array acoustic logging tool

    Science.gov (United States)

    Men, Baiyong; Ju, Xiaodong; Lu, Junqiang; Qiao, Wenxiao

    2016-12-01

    In high-temperature and spatial borehole applications, a distributed structure is employed in a multidimensional array acoustic logging tool (MDALT) based on a phased array technique for electronic systems. However, new challenges, such as synchronous multichannel data acquisition, multinode real-time control and bulk data transmission in a limited interval, have emerged. To address these challenges, we developed a synchronous serial bus (SSB) in this study. SSB works in a half-duplex mode via a master-slave architecture. It also consists of a single master, several slaves, a differential clock line and a differential data line. The clock line is simplex, whereas the data line is half-duplex and synchronous to the clock line. A reliable communication between the master and the slaves with real-time adjustment of synchronisation is achieved by rationally designing the frame format and protocol of communication and by introducing a scramble code and a Hamming error-correcting code. The control logic of the master and the slaves is realized in field programmable gate array (FPGA) or complex programmable logic device (CPLD). The clock speed of SSB is 10 MHz, the effective data rate of the bulk data transmission is over 99%, and the synchronous errors amongst the slaves are less than 10 ns. Room-temperature test, high-temperature test (175 °C) and field test demonstrate that the proposed SSB is qualified for MDALT.

  14. Bodily Synchronization Underlying Joke Telling

    Directory of Open Access Journals (Sweden)

    R. C. Schmidt

    2014-08-01

    Full Text Available 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.

  15. Vestibular hearing and neural synchronization.

    Science.gov (United States)

    Emami, Seyede Faranak; Daneshi, Ahmad

    2012-01-01

    Objectives. Vestibular hearing as an auditory sensitivity of the saccule in the human ear is revealed by cervical vestibular evoked myogenic potentials (cVEMPs). The range of the vestibular hearing lies in the low frequency. Also, the amplitude of an auditory brainstem response component depends on the amount of synchronized neural activity, and the auditory nerve fibers' responses have the best synchronization with the low frequency. Thus, the aim of this study was to investigate correlation between vestibular hearing using cVEMPs and neural synchronization via slow wave Auditory Brainstem Responses (sABR). Study Design. This case-control survey was consisted of twenty-two dizzy patients, compared to twenty healthy controls. Methods. Intervention comprised of Pure Tone Audiometry (PTA), Impedance acoustic metry (IA), Videonystagmography (VNG), fast wave ABR (fABR), sABR, and cVEMPs. Results. The affected ears of the dizzy patients had the abnormal findings of cVEMPs (insecure vestibular hearing) and the abnormal findings of sABR (decreased neural synchronization). Comparison of the cVEMPs at affected ears versus unaffected ears and the normal persons revealed significant differences (P < 0.05). Conclusion. Safe vestibular hearing was effective in the improvement of the neural synchronization.

  16. Sex and estrous cycle-dependent rapid protein kinase signaling actions of estrogen in distal colonic cells.

    LENUS (Irish Health Repository)

    O'Mahony, Fiona

    2008-10-01

    Previous studies from our laboratory demonstrated that 17beta-estradiol (E2) rapidly inhibits Cl(-) secretion in rat and human distal colonic epithelium. The inhibition has been shown to occur via targeting of a basolateral K(+) channel identified as the KCNQ1 (KvLQT1) channel. E2 indirectly modulates the channel activity via a cascade of second messengers which are rapidly phosphorylated in response to E2. The anti-secretory mechanism may be the manner by which E2 induces fluid retention in the intestine during periods of high circulating plasma E2. Here we review the sex-dependent and estrous cycle regulation of this novel rapid response to E2. The inhibition of KCNQ1 channel activity and Cl(-) secretion will be of interest in the future in the investigation of the retentive effects of estrogen in female tissue and also in the study of secretory disorders and drugable targets of the intestine.

  17. The vaginal microbiome is stable in prepubertal and sexually mature Ellegaard Göttingen Minipigs throughout an estrous cycle

    DEFF Research Database (Denmark)

    Lorenzen, Emma; Kudirkiene, Egle; Gutman, Nicole

    2015-01-01

    Although the pig has been introduced as an advanced animal model of genital tract infections in women, almost no knowledge exists on the porcine vaginal microbiota, especially in barrier-raised Göttingen Minipigs. In women, the vaginal microbiota plays a crucial role for a healthy vaginal...... environment and the fate of sexually transmitted infections such as Chlamydia trachomatis infections. Therefore, knowledge on the vaginal microbiota is urgently needed for the minipig model. The aim of this study was to characterize the microbiota of the anterior vagina by 16 s rRNA gene sequencing...... in prepubertal and sexually mature Göttingen Minipigs during an estrous cycle. The dominating phyla in the vaginal microbiota consisted of Firmicutes, Proteobacteria, Actinobacteria, Bacteriodetes and Tenericutes. The most abundant bacterial families were Enterobacteriaceae, unclassified families from...

  18. Cyclic estrous-like behavior in a spayed cat associated with excessive sex-hormone production by an adrenocortical carcinoma.

    Science.gov (United States)

    Meler, Erika N; Scott-Moncrieff, J Catharine; Peter, Augustine T; Bennett, Sara; Ramos-Vara, Jose; Salisbury, S Kathleen; Naughton, James F

    2011-06-01

    A 15-year-old, spayed female domestic shorthair cat was evaluated for 1-year duration of cyclic intermittent estrous behavior. Diagnostic testing performed before referral, including baseline progesterone concentration, human chorionic gonadotropin (hCG) hormone stimulation test and surgical exploratory laparotomy, had remained inconclusive for a remnant ovary. Evaluation of sex hormones before and after adrenocorticotropic hormone (ACTH) administration revealed increased basal concentrations of androstenedione, estradiol, progesterone, and 17α-hydroxyprogesterone and normal ACTH-stimulated hormone concentrations. Enlargement of the right adrenal gland was identified by abdominal ultrasound. The cat underwent an adrenalectomy and histopathology of the excised adrenal gland was consistent with an adrenocortical carcinoma. Clinical signs resolved immediately following surgery, and most hormone concentrations declined to within or below the reference interval (RI) by 2 months after surgery. Copyright © 2011 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.

  19. Effects of the estrous cycle, pregnancy and interferon tau on expression of cyclooxygenase two (COX-2 in ovine endometrium

    Directory of Open Access Journals (Sweden)

    Bazer Fuller W

    2003-08-01

    Full Text Available Abstract In sheep, the uterus produces luteolytic pulses of prostaglandin F2α (PGF on Days 15 to 16 of estrous cycle to regress the corpus luteum (CL. These PGF pulses are produced by the endometrial lumenal epithelium (LE and superficial ductal glandular epithelium (sGE in response to binding of pituitary and/or luteal oxytocin to oxytocin receptors (OTR and liberation of arachidonic acid, the precursor of PGF. Cyclooxygenase-one (COX-1 and COX-2 are rate-limiting enzymes in PGF synthesis, and COX-2 is the major form expressed in ovine endometrium. During pregnancy recognition, interferon tau (IFNτ, produced by the conceptus trophectoderm, acts in a paracrine manner to suppress development of the endometrial epithelial luteolytic mechanism by inhibiting transcription of estrogen receptor α (ERα (directly and OTR (indirectly genes. Conflicting studies indicate that IFNτ increases, decreases or has no effect on COX-2 expression in bovine and ovine endometrial cells. In Study One, COX-2 mRNA and protein were detected solely in endometrial LE and sGE of both cyclic and pregnant ewes. During the estrous cycle, COX-2 expression increased from Days 10 to 12 and then decreased to Day 16. During early pregnancy, COX-2 expression increased from Days 10 to 12 and remained higher than in cyclic ewes. In Study Two, intrauterine infusion of recombinant ovine IFNτ in cyclic ewes from Days 11 to 16 post-estrus did not affect COX-2 expression in the endometrial epithelium. These results clearly indicate that IFNτ has no effect on expression of the COX-2 gene in the ovine endometrium. Therefore, antiluteolytic effects of IFNτ are to inhibit ERα and OTR gene transcription, thereby preventing endometrial production of luteolytic pulses of PGF. Indeed, expression of COX-2 in the endometrial epithelia as well as conceptus is likely to have a beneficial regulatory role in implantation and development of the conceptus.

  20. VEGF, VEGFR-1 and VEGFR-2 immunoreactivity in the porcine arteries of vascular subovarian plexus (VSP during the estrous cycle.

    Directory of Open Access Journals (Sweden)

    A Andronowska

    2006-04-01

    Full Text Available Abstract: Vascular endothelial growth factor (VEGF is an important angiogenic factor in the female reproductive tract. It binds to cell surface through ligand-stimulatable tyrosine kinase receptors, the most important being VEGFR-1 (flt-1 and VEGFR-2 (flk-1. The broad ligament of the uterus is a dynamic organ consisting of specialized complexes of blood vessels connected functionally to the uterus, oviduct and ovary. Endothelial cells form an inner coating of the vessel walls and thus they stay under the influence of various modulators circulating in blood including ovarian steriods involved in developmental changes in the female reproductive system. The aim of the present study was to immunolocalize VEGF and its two receptors: VEGFR-1 and VEGFR-2 in the broad ligament of the uterus in the area of vascular subovarian plexus during different phases of the estrous cycle in pig and to determine the correlation between immunoreactivity of the investigated factors and phases of the estrous cycle. The study was performed on cryostat sections of vascular subovarian plexus stained immunohistochemically by ABC method. Specific polyclonal antibodies: anti-VEGF, anti-VEGFR-1 and anti-VEGFR-2 were used. Data were subjected to one-way analysis of variance. Our study revealed the presence of VEGF and its receptors in endothelial and smooth muscle cells of VSP arteries. All agents displayed phase-related differences in immunoreactivity suggesting the modulatory effect of VEGF, VEGFR-1 and VEGFR-2 on the arteries of the VSP in the porcine broad ligament of the uterus.

  1. SPEEDES - A multiple-synchronization environment for parallel discrete-event simulation

    Science.gov (United States)

    Steinman, Jeff S.

    1992-01-01

    Synchronous Parallel Environment for Emulation and Discrete-Event Simulation (SPEEDES) is a unified parallel simulation environment. It supports multiple-synchronization protocols without requiring users to recompile their code. When a SPEEDES simulation runs on one node, all the extra parallel overhead is removed automatically at run time. When the same executable runs in parallel, the user preselects the synchronization algorithm from a list of options. SPEEDES currently runs on UNIX networks and on the California Institute of Technology/Jet Propulsion Laboratory Mark III Hypercube. SPEEDES also supports interactive simulations. Featured in the SPEEDES environment is a new parallel synchronization approach called Breathing Time Buckets. This algorithm uses some of the conservative techniques found in Time Bucket synchronization, along with the optimism that characterizes the Time Warp approach. A mathematical model derived from first principles predicts the performance of Breathing Time Buckets. Along with the Breathing Time Buckets algorithm, this paper discusses the rules for processing events in SPEEDES, describes the implementation of various other synchronization protocols supported by SPEEDES, describes some new ones for the future, discusses interactive simulations, and then gives some performance results.

  2. Linear Synchronous Motor Repeatability Tests

    International Nuclear Information System (INIS)

    Ward, C.R.

    2002-01-01

    A cart system using linear synchronous motors was being considered for the Plutonium Immobilization Plant (PIP). One of the applications in the PIP was the movement of a stack of furnace trays, filled with the waste form (pucks) from a stacking/unstacking station to several bottom loaded furnaces. A system was ordered to perform this function in the PIP Ceramic Prototype Test Facility (CPTF). This system was installed and started up in SRTC prior to being installed in the CPTF. The PIP was suspended and then canceled after the linear synchronous motor system was started up. This system was used to determine repeatability of a linear synchronous motor cart system for the Modern Pit Facility

  3. A synchronous game for binary constraint systems

    Science.gov (United States)

    Kim, Se-Jin; Paulsen, Vern; Schafhauser, Christopher

    2018-03-01

    Recently, Slofstra proved that the set of quantum correlations is not closed. We prove that the set of synchronous quantum correlations is not closed, which implies his result, by giving an example of a synchronous game that has a perfect quantum approximate strategy but no perfect quantum strategy. We also exhibit a graph for which the quantum independence number and the quantum approximate independence number are different. We prove new characterisations of synchronous quantum approximate correlations and synchronous quantum spatial correlations. We solve the synchronous approximation problem of Dykema and the second author, which yields a new equivalence of Connes' embedding problem in terms of synchronous correlations.

  4. Control of non-conventional synchronous motors

    CERN Document Server

    Louis, Jean-Paul

    2013-01-01

    Classical synchronous motors are the most effective device to drive industrial production systems and robots with precision and rapidity. However, numerous applications require efficient controls in non-conventional situations. Firstly, this is the case with synchronous motors supplied by thyristor line-commutated inverters, or with synchronous motors with faults on one or several phases. Secondly, many drive systems use non-conventional motors such as polyphase (more than three phases) synchronous motors, synchronous motors with double excitation, permanent magnet linear synchronous motors,

  5. Simulating synchronization in neuronal networks

    Science.gov (United States)

    Fink, Christian G.

    2016-06-01

    We discuss several techniques used in simulating neuronal networks by exploring how a network's connectivity structure affects its propensity for synchronous spiking. Network connectivity is generated using the Watts-Strogatz small-world algorithm, and two key measures of network structure are described. These measures quantify structural characteristics that influence collective neuronal spiking, which is simulated using the leaky integrate-and-fire model. Simulations show that adding a small number of random connections to an otherwise lattice-like connectivity structure leads to a dramatic increase in neuronal synchronization.

  6. Synchronous-flux-generator (SFG)

    Energy Technology Data Exchange (ETDEWEB)

    Zweygbergk, S.V.; Ljungstroem, O. (ed.)

    1976-01-01

    The synchronous machine is the most common rotating electric machine for producing electric energy in a large scale, but it is also used for other purposes. One well known everyday example is its use as driving motor in the electric synchronous clock. One has in this connection made full use of one of the main qualities of this kind of machine--its rotating speed is bound to the frequency of the feeding voltage, either if it is working as a motor or as a generator. Characteristics are discussed.

  7. Bandwidth Efficient Hybrid Synchronization for Wireless Sensor Network

    DEFF Research Database (Denmark)

    Dnyaneshwar, Mantri; Prasad, Neeli R.; Prasad, Ramjee

    2015-01-01

    Data collection and transmission are the fundamental operations of Wireless Sensor Networks (WSNs). A key challenge in effective data collection and transmission is to schedule and synchronize the activities of the nodes with the global clock. This paper proposes the Bandwidth Efficient Hybrid...... in the network and then perform the pair-wise synchronization. With the mobility of node, the structure frequently changes causing an increase in energy consumption. To mitigate the problem BESDA aggregate data with the notion of a global timescale throughout the network and schedule based time-division multiple...... accesses (TDMA) techniques as MAC layer protocol. It reduces the collision of packets. Simulation results show that BESDA is energy efficient, with increased throughput, and has less delay as compared with state-of-the-art....

  8. GPS Synchronization of Smart Distributed Converters for Microgrid Applications

    Directory of Open Access Journals (Sweden)

    Tarek A. Youssef

    2018-03-01

    Full Text Available In this paper, a smart distributed DC/DC converter synchronization advanced technique and phase angle optimization algorithm are proposed using to reduce the DC bus overall ripple. A global positioning system-based scheme is used to synchronize the carrier among the distributed converters. The carrier phase angle optimization among the different converters is inspired by Carrier-Sense Multiple Access protocol. The proposed system is simulated and analyzed using Matlab/Simulink program. As a proof of concept of the proposed technique, two case studies have been investigated under equal and unequal load sharing among the distributed generators. The proposed algorithm shows a significant reduction in the DC bus voltage ripple. To prove the concept, a laboratory test-bed has been built and the proposed algorithm has been implemented to validate the theoretical and simulation results. The close agreement between the experimental and simulation results demonstrates the effectiveness and validity of the proposed algorithm.

  9. Public channel cryptography: chaos synchronization and Hilbert's tenth problem.

    Science.gov (United States)

    Kanter, Ido; Kopelowitz, Evi; Kinzel, Wolfgang

    2008-08-22

    The synchronization process of two mutually delayed coupled deterministic chaotic maps is demonstrated both analytically and numerically. The synchronization is preserved when the mutually transmitted signals are concealed by two commutative private filters, a convolution of the truncated time-delayed output signals or some powers of the delayed output signals. The task of a passive attacker is mapped onto Hilbert's tenth problem, solving a set of nonlinear Diophantine equations, which was proven to be in the class of NP-complete problems [problems that are both NP (verifiable in nondeterministic polynomial time) and NP-hard (any NP problem can be translated into this problem)]. This bridge between nonlinear dynamics and NP-complete problems opens a horizon for new types of secure public-channel protocols.

  10. Design of Timing Synchronization Software on EAST-NBI

    International Nuclear Information System (INIS)

    Zhao Yuanzhe; Hu Chundong; Sheng Peng; Zhang Xiaodan

    2013-01-01

    To ensure the uniqueness and recognition of data and make it easy to analyze and process the data of all subsystems of the neutral beam injector (NBI), it is required that all subsystems have a unified system time. In this paper, the timing synchronization software is presented which is related to many kinds of technologies, such as shared memory, multithreading, TCP protocol and so on. Shared memory helps the server save the information of clients and system time, multithreading can deal with different clients with different threads, the server works under Linux operating system, the client works under Linux operating system and Windows operating system. With the help of this design, synchronization of all subsystems can be achieved in less than one second, and this accuracy is enough for the NBI system and the reliability of data is thus ensured. (fusion engineering)

  11. White Rabbit Precision Time Protocol on Long-Distance Fiber Links

    NARCIS (Netherlands)

    Dierikx, E.F.; Dierikx, A.E.; Fordell, T.; Myyry, J.; Koponen, P.; Merimaa, M.; Pinkert, T.J.; Koelemeij, J.C.J.; Peek, H.Z.; Smets, R.

    2016-01-01

    The application of White Rabbit precision time protocol (WR-PTP) in long-distance optical fiber links has been investigated. WR-PTP is an implementation of PTP in synchronous Ethernet optical fiber networks, originally intended for synchronization of equipment within a range of 10 km. This paper

  12. Body condition loss and increased serum levels of nonesterified fatty acids enhance progesterone levels at estrus and reduce estrous activity and insemination rates in postpartum dairy cows.

    Science.gov (United States)

    Lüttgenau, J; Purschke, S; Tsousis, G; Bruckmaier, R M; Bollwein, H

    2016-03-01

    Data from 96 Holstein Friesian cows on a commercial dairy farm were used to investigate whether body condition and serum levels of nonesterified fatty acids (NEFAs) postpartum (pp) affect progesterone (P4) levels, estrous activity, and fertility in dairy cows. The examination period started 14 days before the expected calving date and ended either when a cow was inseminated or at a maximum of 90 days pp. Body condition score (BCS; 1-5 scale) and backfat thickness (BFT) were determined every 2 weeks. Blood for analysis of NEFA and P4 concentrations was sampled weekly during the first 35 days pp and then every 48 hours until an ovulation was observed. Transrectal ultrasonography of the ovaries started at 21 days pp and was performed after blood sampling. If cows were not inseminated because of silent ovulation, sampling and ultrasonography continued on Days 7, 14, and 18 after ovulation and again every 48 hours until the next ovulation. Estrous activity was continuously measured with the Heatime estrus detection system. Pregnancy controls were performed ultrasonographically 28 and 42 days after AI. Cows with increased NEFA levels at 28 days pp had an increased risk of maintaining minimum P4 levels above 0.4 ng/mL at first recognized estrus (P = 0.03). Higher NEFA levels at Day 7 were associated with lower probability for a cow to have elevated P4 levels (≥2 ng/mL) by Day 35 pp, indicating delayed commencement of luteal activity (C-LA). Estrous activity was not influenced (P > 0.10) by minimum P4 concentrations at estrus, but more animals with C-LA until Day 35 pp showed estrous activity compared to cows without C-LA throughout this period (P = 0.006). Estrous activity was lower in cows with a low BCS 14 days pp (P = 0.02) and with a low BFT 42 days pp (P = 0.03). Moreover, the probability to exhibit estrus was reduced with higher NEFA levels at 21 days pp (P = 0.01). Eighty-five cows were inseminated and 37 (44%) got pregnant after insemination. Higher NEFA levels

  13. Measurement of Survival Time in Brachionus Rotifers: Synchronization of Maternal Conditions.

    Science.gov (United States)

    Kaneko, Gen; Yoshinaga, Tatsuki; Gribble, Kristin E; Welch, David M; Ushio, Hideki

    2016-07-22

    Rotifers are microscopic cosmopolitan zooplankton used as models in ecotoxicological and aging studies due to their several advantages such as short lifespan, ease of culture, and parthenogenesis that enables clonal culture. However, caution is required when measuring their survival time as it is affected by maternal age and maternal feeding conditions. Here we provide a protocol for powerful and reproducible measurement of the survival time in Brachionus rotifers following a careful synchronization of culture conditions over several generations. Empirically, poor synchronization results in early mortality and a gradual decrease in survival rate, thus resulting in weak statistical power. Indeed, under such conditions, calorie restriction (CR) failed to significantly extend the lifespan of B. plicatilis although CR-induced longevity has been demonstrated with well-synchronized rotifer samples in past and present studies. This protocol is probably useful for other invertebrate models, including the fruitfly Drosophila melanogaster and the nematode Caenorhabditis elegans, because maternal age effects have also been reported in these species.

  14. Cryptographic Protocols:

    DEFF Research Database (Denmark)

    Geisler, Martin Joakim Bittel

    cryptography was thus concerned with message confidentiality and integrity. Modern cryptography cover a much wider range of subjects including the area of secure multiparty computation, which will be the main topic of this dissertation. Our first contribution is a new protocol for secure comparison, presented...... implemented the comparison protocol in Java and benchmarks show that is it highly competitive and practical. The biggest contribution of this dissertation is a general framework for secure multiparty computation. Instead of making new ad hoc implementations for each protocol, we want a single and extensible...... in Chapter 2. Comparisons play a key role in many systems such as online auctions and benchmarks — it is not unreasonable to say that when parties come together for a multiparty computation, it is because they want to make decisions that depend on private information. Decisions depend on comparisons. We have...

  15. Pinning Synchronization of Switched Complex Dynamical Networks

    Directory of Open Access Journals (Sweden)

    Liming Du

    2015-01-01

    Full Text Available Network topology and node dynamics play a key role in forming synchronization of complex networks. Unfortunately there is no effective synchronization criterion for pinning synchronization of complex dynamical networks with switching topology. In this paper, pinning synchronization of complex dynamical networks with switching topology is studied. Two basic problems are considered: one is pinning synchronization of switched complex networks under arbitrary switching; the other is pinning synchronization of switched complex networks by design of switching when synchronization cannot achieved by using any individual connection topology alone. For the two problems, common Lyapunov function method and single Lyapunov function method are used respectively, some global synchronization criteria are proposed and the designed switching law is given. Finally, simulation results verify the validity of the results.

  16. Fermi Timing and Synchronization System

    International Nuclear Information System (INIS)

    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.

    2006-01-01

    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

  17. Epidemic Synchronization in Robotic Swarms

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Nielsen, Jens Frederik Dalsgaard; Ngo, Trung Dung

    2009-01-01

    Clock synchronization in swarms of networked mobile robots is studied in a probabilistic, epidemic framework. In this setting communication and synchonization is considered to be a randomized process, taking place at unplanned instants of geographical rendezvous between robots. In combination...... as an infinite-dimensional optimal controlproblem. Illustrative numerical examples are given and commented....

  18. Fermi Timing and Synchronization System

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Main injector synchronous timing system

    International Nuclear Information System (INIS)

    Blokland, W.; Steimel, J.

    1998-01-01

    The Synchronous Timing System is designed to provide sub-nanosecond timing to instrumentation during the acceleration of particles in the Main Injector. Increased energy of the beam particles leads to a small but significant increase in speed, reducing the time it takes to complete a full turn of the ring by 61 nanoseconds (or more than 3 rf buckets). In contrast, the reference signal, used to trigger instrumentation and transmitted over a cable, has a constant group delay. This difference leads to a phase slip during the ramp and prevents instrumentation such as dampers from properly operating without additional measures. The Synchronous Timing System corrects for this phase slip as well as signal propagation time changes due to temperature variations. A module at the LLRF system uses a 1.2 Gbit/s G-Link chip to transmit the rf clock and digital data (e.g. the current frequency) over a single mode fiber around the ring. Fiber optic couplers at service buildings split off part of this signal for a local module which reconstructs a synchronous beam reference signal. This paper describes the background, design and expected performance of the Synchronous Timing System. copyright 1998 American Institute of Physics

  20. Main injector synchronous timing system

    International Nuclear Information System (INIS)

    Blokland, Willem; Steimel, James

    1998-01-01

    The Synchronous Timing System is designed to provide sub-nanosecond timing to instrumentation during the acceleration of particles in the Main Injector. Increased energy of the beam particles leads to a small but significant increase in speed, reducing the time it takes to complete a full turn of the ring by 61 nanoseconds (or more than 3 rf buckets). In contrast, the reference signal, used to trigger instrumentation and transmitted over a cable, has a constant group delay. This difference leads to a phase slip during the ramp and prevents instrumentation such as dampers from properly operating without additional measures. The Synchronous Timing System corrects for this phase slip as well as signal propagation time changes due to temperature variations. A module at the LLRF system uses a 1.2 Gbit/s G-Link chip to transmit the rf clock and digital data (e.g. the current frequency) over a single mode fiber around the ring. Fiber optic couplers at service buildings split off part of this signal for a local module which reconstructs a synchronous beam reference signal. This paper describes the background, design and expected performance of the Synchronous Timing System

  1. Generalized synchronization via impulsive control

    International Nuclear Information System (INIS)

    Zhang Rong; Xu Zhenyuan; Yang, Simon X.; He Xueming

    2008-01-01

    This paper demonstrates theoretically that two completely different systems can implement GS via impulsive control, moreover by using impulsive control, for a given manifold y = H(x) we construct a response system to achieve GS with drive system and the synchronization manifold is y = H(x). Our theoretical results are supported by numerical examples

  2. Learning through synchronous electronic discussion

    NARCIS (Netherlands)

    Kanselaar, G.; Veerman, A.L.; Andriessen, J.E.B.

    2000-01-01

    This article reports a study examining university student pairs carrying out an electronic discussion task in a synchronous computer mediated communication (CMC) system (NetMeeting). The purpose of the assignment was to raise students' awareness concerning conceptions that characterise effective

  3. Epidemic Synchronization in Robotic Swarms

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Nielsen, Jens Frederik Dalsgaard; Ngo, Trung Dung

    2009-01-01

    Clock synchronization in swarms of networked mobile robots is studied in a probabilistic, epidemic framework. In this setting communication and synchonization is considered to be a randomized process, taking place at unplanned instants of geographical rendezvous between robots. In combination wit...

  4. Digital device for synchronous storage

    International Nuclear Information System (INIS)

    Kobzar', Yu.M.; Kovtun, V.G.; Pashechko, N.I.

    1991-01-01

    Synchronous storage digital device for IR electron-photon emission spectrometer operating with analogue-to-digital converter F4223 or monocrystal converter K572PV1 is described. The device accomplished deduction of noise-background in each storage cycle. Summation and deduction operational time equals 90 ns, device output code discharge - 20, number of storages -2 23

  5. Neural synchronization via potassium signaling

    DEFF Research Database (Denmark)

    Postnov, Dmitry E; Ryazanova, Ludmila S; Mosekilde, Erik

    2006-01-01

    Using a relatively simple model we examine how variations of the extracellular potassium concentration can give rise to synchronization of two nearby pacemaker cells. With the volume of the extracellular space and the rate of potassium diffusion as control parameters, the dual nature of this reso...

  6. Anti-synchronization of chaotic oscillators

    International Nuclear Information System (INIS)

    Kim, Chil-Min; Rim, Sunghwan; Kye, Won-Ho; Ryu, Jung-Wan; Park, Young-Jai

    2003-01-01

    We have observed anti-synchronization phenomena in coupled identical chaotic oscillators. Anti-synchronization can be characterized by the vanishing of the sum of relevant variables. We have qualitatively analyzed its base mechanism by using the dynamics of the difference and the sum of the relevant variables in coupled chaotic oscillators. Near the threshold of the synchronization and anti-synchronization transition, we have obtained the novel characteristic relation

  7. Robust synchronization of chaotic systems via feedback

    Energy Technology Data Exchange (ETDEWEB)

    Femat, Ricardo [IPICYT, San Luis Potosi (Mexico). Dept. de Matematicas Aplicadas; Solis-Perales, Gualberto [Universidad de Guadalajara, Centro Univ. de Ciencias Exactas e Ingenierias (Mexico). Div. de Electronica y Computacion

    2008-07-01

    This volume includes the results derived during last ten years about both suppression and synchronization of chaotic -continuous time- systems. Along this time, the concept was to study how the intrinsic properties of dynamical systems can be exploited to suppress and to synchronize the chaotic behaviour and what synchronization phenomena can be found under feedback interconnection. A compilation of these findings is described in this book. This book shows a perspective on synchronization of chaotic systems. (orig.)

  8. Two novel synchronization criterions for a unified chaotic system

    International Nuclear Information System (INIS)

    Tao Chaohai; Xiong Hongxia; Hu Feng

    2006-01-01

    Two novel synchronization criterions are proposed in this paper. It includes drive-response synchronization and adaptive synchronization schemes. Moreover, these synchronization criterions can be applied to a large class of chaotic systems and are very useful for secure communication

  9. 40 CFR 93.128 - Traffic signal synchronization projects.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Traffic signal synchronization... synchronization projects. Traffic signal synchronization projects may be approved, funded, and implemented without... include such regionally significant traffic signal synchronization projects. ...

  10. Effect of a postnatal high-fat diet exposure on puberty onset, estrous cycle regularity, and kisspeptin expression in female rats

    DEFF Research Database (Denmark)

    Lie, Maria Elena Klibo; Overgaard, Agnete; Mikkelsen, Jens D

    2013-01-01

    Kisspeptin, encoded by Kiss1, plays a key role in pubertal maturation and reproduction as a positive upstream regulator of the hypothalamic-pituitary-gonadal (HPG) axis. To examine the role of high-fat diet (HFD) on puberty onset, estrous cycle regularity, and kisspeptin expression, female rats...... were exposed to HFD in distinct postnatal periods. Three groups of rats were exposed to HFD containing 60% energy from fat during the pre-weaning period (postnatal day (PND) 1-16, HFD PND 1-16), post-weaning period (HFD PND 21-34), or during both periods (HFD PND 1-34). Puberty onset, evaluated...... that postnatal HFD exposure induced irregular estrous cycles, but had no effect on puberty onset or kisspeptin....

  11. Synchronization of indirectly coupled Lorenz oscillators

    Indian Academy of Sciences (India)

    Synchronization of indirectly coupled Lorenz oscillators: An experimental study. Amit Sharma Manish Dev Shrimali. Synchronization, Coupled Systems and Networks Volume 77 Issue 5 November 2011 pp 881-889 ... The in-phase and anti-phase synchronization of indirectly coupled chaotic oscillators reported in Phys. Rev ...

  12. Control synchronization of differential mobile robots

    NARCIS (Netherlands)

    Nijmeijer, H.; Rodriguez Angeles, A.; Allgoewer, F.

    2004-01-01

    In this paper a synchronization controller for differential mobile robots is proposed. The synchronization goal is to control the angular position of each wheel to a desired trajectory and at the same time the differential (or synchronization) error between the angular positions of the two wheels.

  13. Chaos synchronization based on contraction principle

    International Nuclear Information System (INIS)

    Wang Junwei; Zhou Tianshou

    2007-01-01

    This paper introduces contraction principle. Based on such a principle, a novel scheme is proposed to synchronize coupled systems with global diffusive coupling. A rigorous sufficient condition on chaos synchronization is derived. As an example, coupled Lorenz systems with nearest-neighbor diffusive coupling are investigated, and numerical simulations are given to validate the proposed synchronization approach

  14. Global chaos synchronization of coupled parametrically excited ...

    Indian Academy of Sciences (India)

    In this paper, we study the synchronization behaviour of two linearly coupled parametrically excited chaotic pendula. The stability of the synchronized state is examined using Lyapunov stability theory and linear matrix inequality (LMI); and some sufficient criteria for global asymptotic synchronization are derived from which ...

  15. Synchronization of coupled nonidentical multidelay feedback systems

    International Nuclear Information System (INIS)

    Hoang, Thang Manh; Nakagawa, Masahiro

    2007-01-01

    We present the lag synchronization of coupled nonidentical multidelay feedback systems, in which the synchronization signal is the sum of nonlinearly transformed components of delayed state variable. The sufficient condition for synchronization is considered by the Krasovskii-Lyapunov theory. The specific examples will demonstrate and verify the effectiveness of the proposed model

  16. Synchronization and comparison of Lifelog audio recordings

    DEFF Research Database (Denmark)

    Nielsen, Andreas Brinch; Hansen, Lars Kai

    2008-01-01

    as a preprocessing step to select and synchronize recordings before further processing. The two methods perform similarly in classification, but fingerprinting scales better with the number of recordings, while cross-correlation can offer sample resolution synchronization. We propose and investigate the benefits...... of combining the two. In particular we show that the combination allows sample resolution synchronization and scalability....

  17. Immunochemical protocols

    National Research Council Canada - National Science Library

    Pound, John D

    1998-01-01

    ... easy and important refinements often are not published. This much anticipated 2nd edition of Immunochemzcal Protocols therefore aims to provide a user-friendly up-to-date handbook of reliable techniques selected to suit the needs of molecular biologists. It covers the full breadth of the relevant established immunochemical methods, from protein blotting and immunoa...

  18. New type of chaos synchronization in discrete-time systems: the F-M synchronization

    Directory of Open Access Journals (Sweden)

    Ouannas Adel

    2018-04-01

    Full Text Available In this paper, a new type of synchronization for chaotic (hyperchaotic maps with different dimensions is proposed. The novel scheme is called F – M synchronization, since it combines the inverse generalized synchronization (based on a functional relationship F with the matrix projective synchronization (based on a matrix M. In particular, the proposed approach enables F – M synchronization with index d to be achieved between n-dimensional drive system map and m-dimensional response system map, where the synchronization index d corresponds to the dimension of the synchronization error. The technique, which exploits nonlinear controllers and Lyapunov stability theory, proves to be effective in achieving the F – M synchronization not only when the synchronization index d equals n or m, but even if the synchronization index d is larger than the map dimensions n and m. Finally, simulation results are reported, with the aim to illustrate the capabilities of the novel scheme proposed herein.

  19. New type of chaos synchronization in discrete-time systems: the F-M synchronization

    Science.gov (United States)

    Ouannas, Adel; Grassi, Giuseppe; Karouma, Abdulrahman; Ziar, Toufik; Wang, Xiong; Pham, Viet-Thanh

    2018-04-01

    In this paper, a new type of synchronization for chaotic (hyperchaotic) maps with different dimensions is proposed. The novel scheme is called F - M synchronization, since it combines the inverse generalized synchronization (based on a functional relationship F) with the matrix projective synchronization (based on a matrix M). In particular, the proposed approach enables F - M synchronization with index d to be achieved between n-dimensional drive system map and m-dimensional response system map, where the synchronization index d corresponds to the dimension of the synchronization error. The technique, which exploits nonlinear controllers and Lyapunov stability theory, proves to be effective in achieving the F - M synchronization not only when the synchronization index d equals n or m, but even if the synchronization index d is larger than the map dimensions n and m. Finally, simulation results are reported, with the aim to illustrate the capabilities of the novel scheme proposed herein.

  20. Fos Expression in the Olfactory Pathway of High- and Low-Sexually Performing Rams Exposed to Urine from Estrous or Ovariectomized Ewes

    Science.gov (United States)

    Mirto, AJ; Austin, KJ; Uthlaut, VA; Roselli, CE; Alexander, BM

    2015-01-01

    Exposure to estrous ewe urine stimulates investigation and mounting activity in sexually active but not sexually inactive rams. It was hypothesized sexual indifference may result from an inability to detect olfactory cues or an interruption of the pathway from detection of the olfactory stimulus to the motor response. Sexually active (n=4) and inactive (n=3) rams were exposed to urine from estrous ewes. An additional group of sexually active rams (n=3) were exposed to urine from ovariectomized ewes. Rams were exsanguinated following 1 h of exposure to stimulus. Neural activity was determined in tissues of interest by the presence of fos and fos-related proteins detected by immunohistochemistry procedures. Sexually active rams exposed to urine from ovariectomized ewes had more (P ≤ 0.05) fos-positive cells in the olfactory bulb, but fewer (P = 0.03) fos-positive cells in the cortical amygdala compared to sexually active rams exposed to urine from estrous ewes. Sexually inactive rams had similar (P ≥ 0.13) numbers of fos positive neurons in the olfactory bulb and medial amygdala but fewer (P ≤ 0.04) in the central amygdala, bed nucleus of the stria terminalis and the medial preoptic area compared to sexually active rams exposed to urine from estrous ewes. Sexual inactivity was not associated with decreased hypothalamic function since fos activity was similar (P ≥ 0.14) among groups in the suprachiasmatic and ventral medial nucleus. Sexual inactivity is not likely due to an impaired ability to detect or process olfactory stimuli by the main olfactory bulb and medial-cortical amygdala. Sexually inactive rams may have reduced attentiveness to sexual stimuli and/or decreased responsiveness of regions in the brain which regulate reproductive behaviors. PMID:28348447

  1. Voluntary Exercise Improves Estrous Cyclicity in Prenatally Androgenized Female Mice Despite Programming Decreased Voluntary Exercise: Implications for Polycystic Ovary Syndrome (PCOS).

    Science.gov (United States)

    Homa, Lori D; Burger, Laura L; Cuttitta, Ashley J; Michele, Daniel E; Moenter, Suzanne M

    2015-12-01

    Prenatal androgen (PNA) exposure in mice produces a phenotype resembling lean polycystic ovary syndrome. We studied effects of voluntary exercise on metabolic and reproductive parameters in PNA vs vehicle (VEH)-treated mice. Mice (8 wk of age) were housed individually and estrous cycles monitored. At 10 weeks of age, mice were divided into groups (PNA, PNA-run, VEH, VEH-run, n = 8-9/group); those in the running groups received wheels allowing voluntary running. Unexpectedly, PNA mice ran less distance than VEH mice; ovariectomy eliminated this difference. In ovary-intact mice, there was no difference in glucose tolerance, lower limb muscle fiber types, weight, or body composition among groups after 16 weeks of running, although some mitochondrial proteins were mildly up-regulated by exercise in PNA mice. Before running, estrous cycles in PNA mice were disrupted with most days in diestrus. There was no change in cycles during weeks 1-6 of running (10-15 wk of age). In contrast, from weeks 11 to 16 of running, cycles in PNA mice improved with more days in proestrus and estrus and fewer in diestrus. PNA programs reduced voluntary exercise, perhaps mediated in part by ovarian secretions. Exercise without weight loss improved estrous cycles, which if translated could be important for fertility in and counseling of lean women with polycystic ovary syndrome.

  2. Chaos synchronization of coupled hyperchaotic system

    International Nuclear Information System (INIS)

    Yang Lixin; Chu Yandong; Zhang Jiangang; Li Xianfeng

    2009-01-01

    Chaos synchronization, as an important topic, has become an active research subject in nonlinear science. Over the past two decades, chaos synchronization between nonlinear systems has been extensively studied, and many types of synchronization have been announced. This paper introduces synchronization of coupled hyperchaotic system, based on the Lapunov stability theory, asymptotic stability of the system is guaranteed by means of Lapunov function. The numerical simulation was provided in order to show the effectiveness of this method for the synchronization of the chaotic hyperchaotic Chen system and Rossler system.

  3. Adaptive feedback synchronization of Lue system

    International Nuclear Information System (INIS)

    Han, X.; Lu, J.-A.; Wu, X.

    2004-01-01

    This letter further improves and extends the works of Chen and Lue [Chaos, Solitons and Fractals 14 (2002) 643] and Wang et al. [Phys. Lett. A 312 (2003) 34]. In detail, the linear feedback synchronization and adaptive feedback synchronization for Lue system are discussed. And the lower bound of the feedback gain in linear feedback synchronization is presented. The adaptive feedback synchronization with only one controller is designed, which improves the proof in the work by Wang et al. The adaptive synchronization with two controllers for completely uncertain Lue system is also discussed, which extends the work of Chen and Lue. Also, numerical simulations show the effectiveness of these methods

  4. Targeting engineering synchronization in chaotic systems

    Science.gov (United States)

    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.

  5. Analysis of remote synchronization in complex networks

    Science.gov (United States)

    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.

  6. Producing Newborn Synchronous Mammalian Cells

    Science.gov (United States)

    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.

  7. DE-Sync: A Doppler-Enhanced Time Synchronization for Mobile Underwater Sensor Networks.

    Science.gov (United States)

    Zhou, Feng; Wang, Qi; Nie, DongHu; Qiao, Gang

    2018-05-25

    Time synchronization is the foundation of cooperative work among nodes of underwater sensor networks; it takes a critical role in the research and application of underwater sensor networks. Although numerous time synchronization protocols have been proposed for terrestrial wireless sensor networks, they cannot be directly applied to underwater sensor networks. This is because most of them typically assume that the propagation delay among sensor nodes is negligible, which is not the case in underwater sensor networks. Time synchronization is mainly affected by a long propagation delay among sensor nodes due to the low propagation speed of acoustic signals. Furthermore, sensor nodes in underwater tend to experience some degree of mobility due to wind or ocean current, or some other nodes are on self-propelled vehicles, such as autonomous underwater vehicles (AUVs). In this paper, we propose a Doppler-enhanced time synchronization scheme for mobile underwater sensor networks, called DE-Sync. Our new scheme considers the effect of the clock skew during the process of estimating the Doppler scale factor and directly substitutes the Doppler scale factor into linear regression to achieve the estimation of the clock skew and offset. Simulation results show that DE-Sync outperforms existing time synchronization protocols in both accuracy and energy efficiency.

  8. Fecal estrogen, progestagen and glucocorticoid metabolites during the estrous cycle and pregnancy in the giant anteater (Myrmecophaga tridactyla): evidence for delayed implantation.

    Science.gov (United States)

    Knott, Katrina K; Roberts, Beth M; Maly, Morgan A; Vance, Carrie K; Debeachaump, Jennifer; Majors, Jackie; Riger, Peter; Decaluwe, Heather; Kouba, Andrew J

    2013-08-27

    Declining numbers of wild giant anteaters highlight the importance of sustainable captive populations. Unfortunately, captive reproductive management is limited by the lack of external physical indicators of female reproductive status and the aggressive behavior of males. We examined the endocrinology of the estrous cycle and pregnancy, and whether delayed implantation is a gestational strategy for giant anteaters as described for other xenarthrans. Feces were collected from seven captive females 3-5 times weekly and mating was recorded. Concentrations of estrogen (estrone-glucuronide, E1, and estradiol-17β, E2), progestagen (20-oxo-progestagens, P4), and glucocorticoid (GC) metabolites were examined in fecal extracts by enzyme immunoassay. Estrous cycles for nulliparous females (6 cycles, n = 2) compared to the multiparous female (6 cycles, n = 1) were shorter (47.3 +/- 4.3 days versus 62.5 +/- 2.6 days) with relatively lower luteal phase concentrations of P4 (49.4 +/- 2.9 ng/g versus 136.8 +/- 1.8 ng/g). The four remaining females had unclear ovarian activity: two females exhibited apparent luteal activity but unclear fluctuations in estrogens, while the other two females had parallel fecal P4 and estrogens concentrations. Pregnancy ranged 171-183 days with females returning to estrus post-partum as early as 60 days (n = 3, 1.8-4 years of age at mating). Delayed implantation was indicated by a biphasic elevation in fecal P4 metabolites: the initial 4-fold increase occurred for 81-105 days and was followed by a 26-fold secondary rise in P4 metabolites lasting 66-94 days prior to parturition. Fecal GC was correlated with fecal estrogens and greatest during estrus, late pregnancy, and six days prior to parturition (estrous cycle GC, 14.4-62.8 ng/g; pregnancy GC, 13.6-232.7 ng/g). Estrous cycles of giant anteaters occurred year-round, but were shorter and more intermittent in younger nulliparous animals compared to a multiparous female. A pronounced

  9. Distributed-observer-based cooperative control for synchronization of linear discrete-time multi-agent systems.

    Science.gov (United States)

    Liang, Hongjing; Zhang, Huaguang; Wang, Zhanshan

    2015-11-01

    This paper considers output synchronization of discrete-time multi-agent systems with directed communication topologies. The directed communication graph contains a spanning tree and the exosystem as its root. Distributed observer-based consensus protocols are proposed, based on the relative outputs of neighboring agents. A multi-step algorithm is presented to construct the observer-based protocols. In light of the discrete-time algebraic Riccati equation and internal model principle, synchronization problem is completed. At last, numerical simulation is provided to verify the effectiveness of the theoretical results. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  10. Major role of suckling stimulation for inhibition of estrous behaviors in lactating rabbits: acute and chronic effects.

    Science.gov (United States)

    García-Dalmán, Cipatli; González-Mariscal, Gabriela

    2012-01-01

    Lactation in rabbits induces anestrus: sexual receptivity and scent-marking (chinning) are reduced despite the brevity of suckling (one daily nursing bout, lasting around 3 min). The mechanisms underlying this effect are unknown but, as chinning, lordosis, and ambulation in an open field are immediately inhibited by the peripheral stimulation received during mating we hypothesized that, across lactation, suckling stimulation would provoke a similar effect. To test this possibility we provided litters of 1, 3, 5, or 10 pups across lactation days 1-15 and quantified chinning and ambulation frequencies, the lordosis quotient, and milk output. Baseline chinning frequency, determined before the daily nursing bout, was low across lactation days 1-15 in does nursing 3, 5 or 10 pups but it increased steadily across days 1-10 in rabbits suckling one pup. Yet, a single young was sufficient to abolish chinning for about 1h, after which this behavior rose again. Suckling litters of all sizes reduced (but did not abolish) ambulation frequency, both chronically (baseline levels declined across days 1-5) and acutely. Sexual receptivity was significantly reduced on lactation day 15 only in does that had nursed 10 pups. Large litter size promoted a larger milk output and a normal duration of nursing episodes. Results support a major role of suckling stimulation for the suppression of estrous behaviors and ambulation through as yet unidentified mechanisms. Copyright © 2011. Published by Elsevier Inc.

  11. Suppression of anomalous synchronization and nonstationary behavior of neural network under small-world topology

    Science.gov (United States)

    Boaretto, B. R. R.; Budzinski, R. C.; Prado, T. L.; Kurths, J.; Lopes, S. R.

    2018-05-01

    It is known that neural networks under small-world topology can present anomalous synchronization and nonstationary behavior for weak coupling regimes. Here, we propose methods to suppress the anomalous synchronization and also to diminish the nonstationary behavior occurring in weakly coupled neural network under small-world topology. We consider a network of 2000 thermally sensitive identical neurons, based on the model of Hodgkin-Huxley in a small-world topology, with the probability of adding non local connection equal to p = 0 . 001. Based on experimental protocols to suppress anomalous synchronization, as well as nonstationary behavior of the neural network dynamics, we make use of (i) external stimulus (pulsed current); (ii) biologic parameters changing (neuron membrane conductance changes); and (iii) body temperature changes. Quantification analysis to evaluate phase synchronization makes use of the Kuramoto's order parameter, while recurrence quantification analysis, particularly the determinism, computed over the easily accessible mean field of network, the local field potential (LFP), is used to evaluate nonstationary states. We show that the methods proposed can control the anomalous synchronization and nonstationarity occurring for weak coupling parameter without any effect on the individual neuron dynamics, neither in the expected asymptotic synchronized states occurring for large values of the coupling parameter.

  12. A simple carrier frequency offset synchronization strategy for multiple relay cooperative diversity ofdm system

    International Nuclear Information System (INIS)

    Mudassar, I.; Cheema, A.; Shoab, A.

    2014-01-01

    Cooperative Diversity Orthogonal Frequency Division Modulation (CD-OFDM) systems are very sensitive to synchronization errors. In CD-OFDM, synchronization is more complex because all cooperative nodes (CNs) have their own frequency oscillator and different channel path which results in different timing and carrier frequency offset (CFO) for each node. Consequently, each node has to be synchronized separately without affecting the synchronization process of other nodes. All CNs transmit simultaneously during cooperation phase (C-phase) and their aggregate signal is received at the destination node. A unique frequency domain (FD) preamble is proposed for each CN during C-phase that will allow simple separation of cooperative nodes. These FD multiplexed preambles make the synchronization problem identical to OFDMA uplink. OFDMA system typically uses highly complex iterative CFO estimators for uplink synchronization. However, a simple one-shot CFO estimator is proposed that uses repeated preamble of two OFDM symbol duration. The proposed method is computationally efficient because it relies on FFT operation for user separation and interference mitigation. Subsequently, time domain (TD) multiplication is used for CFO correction of each CN. Furthermore, a CD-OFDM protocol for data transmission is presented that suites the proposed estimator and harnesses spatial diversity. The proposed estimator shows good statistical results during simulations in AWGN and Rayleigh environments. During evaluation, estimator variance, mean square error and symbol error rate are used as performance measure. (author)

  13. Synchronous implementation of optoelectronic NOR and XNOR logic gates using parallel synchronization of three chaotic lasers

    International Nuclear Information System (INIS)

    Yan Sen-Lin

    2014-01-01

    The parallel synchronization of three chaotic lasers is used to emulate optoelectronic logic NOR and XNOR gates via modulating the light and the current. We deduce a logical computational equation that governs the chaotic synchronization, logical input, and logical output. We construct fundamental gates based on the three chaotic lasers and define the computational principle depending on the parallel synchronization. The logic gate can be implemented by appropriately synchronizing two chaotic lasers. The system shows practicability and flexibility because it can emulate synchronously an XNOR gate, two NOR gates, and so on. The synchronization can still be deteceted when mismatches exist with a certain range. (general)

  14. Study protocol

    DEFF Research Database (Denmark)

    Smith, Benjamin E; Hendrick, Paul; Bateman, Marcus

    2017-01-01

    avoidance behaviours, catastrophising, self-efficacy, sport and leisure activity participation, and general quality of life. Follow-up will be 3 and 6 months. The analysis will focus on descriptive statistics and confidence intervals. The qualitative components will follow a thematic analysis approach....... DISCUSSION: This study will evaluate the feasibility of running a definitive large-scale trial on patients with patellofemoral pain, within the NHS in the UK. We will identify strengths and weaknesses of the proposed protocol and the utility and characteristics of the outcome measures. The results from...... this study will inform the design of a multicentre trial. TRIAL REGISTRATION: ISRCTN35272486....

  15. dynamic-threshold-limited timed-token (dtltt) protocol

    African Journals Online (AJOL)

    2013-03-01

    Mar 1, 2013 ... Token (STOGSTT) Media Access Control (MAC) protocol for channel capacity allocation to the asynchronous traffic in ... Keywords: multi-access, multiservice, network, synchronous, asynchronous, traffic, timed-token. 1. Introduction .... Messages generated in the system at run time may be classified as ...

  16. Partial Synchronization Manifolds for Linearly Time-Delay Coupled Systems

    OpenAIRE

    Steur, Erik; van Leeuwen, Cees; Michiels, Wim

    2014-01-01

    Sometimes a network of dynamical systems shows a form of incomplete synchronization characterized by synchronization of some but not all of its systems. This type of incomplete synchronization is called partial synchronization. Partial synchronization is associated with the existence of partial synchronization manifolds, which are linear invariant subspaces of C, the state space of the network of systems. We focus on partial synchronization manifolds in networks of system...

  17. Design Aspects of An Energy-Efficient, Lightweight Medium Access Control Protocol for Wireless Sensor Networks

    NARCIS (Netherlands)

    van Hoesel, L.F.W.; Havinga, Paul J.M.

    2006-01-01

    This document gives an overview of the most relevant design aspects of the lightweight medium access control (LMAC) protocol [16] for wireless sensor networks (WSNs). These aspects include selfconfiguring and localized operation of the protocol, time synchronization in multi-hop networks, network

  18. Communication protocol in chassis detecting wireless transmission system based on WiFi

    Science.gov (United States)

    In chassis detecting wireless transmission system, the wireless network communication protocol plays a key role in the information exchange and synchronization between the host and chassis PDA. This paper presents a wireless network transmission protocol based on TCP/IP which makes the rules of info...

  19. Nonlinearity induced synchronization enhancement in mechanical oscillators

    Science.gov (United States)

    Czaplewski, David A.; Lopez, Omar; Guest, Jeffrey R.; Antonio, Dario; Arroyo, Sebastian I.; Zanette, Damian H.

    2018-05-08

    An autonomous oscillator synchronizes to an external harmonic force only when the forcing frequency lies within a certain interval, known as the synchronization range, around the oscillator's natural frequency. Under ordinary conditions, the width of the synchronization range decreases when the oscillation amplitude grows, which constrains synchronized motion of micro- and nano-mechanical resonators to narrow frequency and amplitude bounds. The present invention shows that nonlinearity in the oscillator can be exploited to manifest a regime where the synchronization range increases with an increasing oscillation amplitude. The present invention shows that nonlinearities in specific configurations of oscillator systems, as described herein, are the key determinants of the effect. The present invention presents a new configuration and operation regime that enhances the synchronization of micro- and nano-mechanical oscillators by capitalizing on their intrinsic nonlinear dynamics.

  20. A chimeric path to neuronal synchronization

    Science.gov (United States)

    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).

  1. Continuous and discontinuous transitions to synchronization.

    Science.gov (United States)

    Wang, Chaoqing; Garnier, Nicolas B

    2016-11-01

    We describe how the transition to synchronization in a system of globally coupled Stuart-Landau oscillators changes from continuous to discontinuous when the nature of the coupling is moved from diffusive to reactive. We explain this drastic qualitative change as resulting from the co-existence of a particular synchronized macrostate together with the trivial incoherent macrostate, in a range of parameter values for which the latter is linearly stable. In contrast to the paradigmatic Kuramoto model, this particular state observed at the synchronization transition contains a finite, non-vanishing number of synchronized oscillators, which results in a discontinuous transition. We consider successively two situations where either a fully synchronized state or a partially synchronized state exists at the transition. Thermodynamic limit and finite size effects are briefly discussed, as well as connections with recently observed discontinuous transitions.

  2. Synchronization in complex networks with switching topology

    International Nuclear Information System (INIS)

    Wang, Lei; Wang, Qing-guo

    2011-01-01

    This Letter investigates synchronization issues of complex dynamical networks with switching topology. By constructing a common Lyapunov function, we show that local and global synchronization for a linearly coupled network with switching topology can be evaluated by the time average of second smallest eigenvalues corresponding to the Laplacians of switching topology. This result is quite powerful and can be further used to explore various switching cases for complex dynamical networks. Numerical simulations illustrate the effectiveness of the obtained results in the end. -- Highlights: → Synchronization of complex networks with switching topology is investigated. → A common Lyapunov function is established for synchronization of switching network. → The common Lyapunov function is not necessary to monotonically decrease with time. → Synchronization is determined by the second smallest eigenvalue of its Laplacian. → Synchronization criterion can be used to investigate various switching cases.

  3. A chimeric path to neuronal synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Essaki Arumugam, Easwara Moorthy; Spano, Mark L. [School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287-9709 (United States)

    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)

  4. Synchronizing noisy nonidentical oscillators by transient uncoupling

    Energy Technology Data Exchange (ETDEWEB)

    Tandon, Aditya, E-mail: adityat@iitk.ac.in; Mannattil, Manu, E-mail: mmanu@iitk.ac.in [Department of Physics, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016 (India); Schröder, Malte, E-mail: malte@nld.ds.mpg.de [Network Dynamics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen (Germany); Timme, Marc, E-mail: timme@nld.ds.mpg.de [Network Dynamics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen (Germany); Department of Physics, Technical University of Darmstadt, 64289 Darmstadt (Germany); Chakraborty, Sagar, E-mail: sagarc@iitk.ac.in [Department of Physics, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016 (India); Mechanics and Applied Mathematics Group, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016 (India)

    2016-09-15

    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.

  5. A chimeric path to neuronal synchronization

    International Nuclear Information System (INIS)

    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)

  6. Synchronization

    Indian Academy of Sciences (India)

    abnormally low heart rate known as bradycardia. This results in symptoms like fatigue, dizziness and fainting. In such cases ... cycle. Owing to this interaction, the flashing frequencies get entrained and the phases of the fireflies are locked.

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

    Energy Technology Data Exchange (ETDEWEB)

    Danziger, Michael M., E-mail: michael.danziger@biu.ac.il; Havlin, Shlomo [Department of Physics, Bar-Ilan University, Ramat Gan (Israel); Moskalenko, Olga I.; Kurkin, Semen A. [Faculty of Nonlinear Processes, Saratov State University, Astrakhanskaya, 83, Saratov 410012 (Russian Federation); Saratov State Technical University, Politehnicheskaya, 77, Saratov 410054 (Russian Federation); Zhang, Xiyun [Department of Physics, East China Normal University, Shanghai 200062 (China); Boccaletti, Stefano [CNR-Institute of Complex Systems, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence (Italy); The Italian Embassy in Israel, 25 Hamered Street, 68125 Tel Aviv (Israel)

    2016-06-15

    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{sup 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.

  8. Adaptive Synchronization of Robotic Sensor Networks

    OpenAIRE

    Yıldırım, Kasım Sinan; Gürcan, Önder

    2014-01-01

    The main focus of recent time synchronization research is developing power-efficient synchronization methods that meet pre-defined accuracy requirements. However, an aspect that has been often overlooked is the high dynamics of the network topology due to the mobility of the nodes. Employing existing flooding-based and peer-to-peer synchronization methods, are networked robots still be able to adapt themselves and self-adjust their logical clocks under mobile network dynamics? In this paper, ...

  9. Method for Converter Synchronization with RF Injection

    OpenAIRE

    Joshua P. Bruckmeyer; Ivica Kostanic

    2015-01-01

    This paper presents an injection method for synchronizing analog to digital converters (ADC). This approach can eliminate the need for precision routed discrete synchronization signals of current technologies, such as JESD204. By eliminating the setup and hold time requirements at the conversion (or near conversion) clock rate, higher sample rate systems can be synchronized. Measured data from an existing multiple ADC conversion system was used to evaluate the method. Coherent beams were simu...

  10. The synchronization of three fractional differential systems

    International Nuclear Information System (INIS)

    Li Changpin; Yan Jianping

    2007-01-01

    In this paper, a new method is proposed and applied to the synchronization of fractional differential systems (or 'differential systems with fractional orders'), where both drive and response systems have the same dimensionality and are coupled by the driving signal. The present technique is based on the stability criterion of linear fractional systems. This method is implemented in (chaos) synchronization of the fractional Lorenz system, Chen system and Chua circuit. Numerical simulations show the present synchronization method works well

  11. Fitness for synchronization of network motifs

    DEFF Research Database (Denmark)

    Vega, Y.M.; Vázquez-Prada, M.; Pacheco, A.F.

    2004-01-01

    We study the synchronization of Kuramoto's oscillators in small parts of networks known as motifs. We first report on the system dynamics for the case of a scale-free network and show the existence of a non-trivial critical point. We compute the probability that network motifs synchronize, and fi...... that the fitness for synchronization correlates well with motifs interconnectedness and structural complexity. Possible implications for present debates about network evolution in biological and other systems are discussed....

  12. Synchronizing a class of uncertain chaotic systems

    International Nuclear Information System (INIS)

    Chen Maoyin; Zhou Donghua; Shang Yun

    2005-01-01

    This Letter deals with the synchronization of a class of uncertain chaotic systems in the drive-response framework. A robust adaptive observer based response system is designed to synchronize a given chaotic system with unknown parameters and external disturbances. Lyapunov stability ensures the global synchronization between the drive and response systems even if Lipschitz constants on function matrices and bounds on uncertainties are unknown. Numerical simulation of Genesio-Tesi system verifies the effectiveness of this scheme

  13. Impulsive synchronization of Chen's hyperchaotic system

    International Nuclear Information System (INIS)

    Haeri, Mohammad; Dehghani, Mahsa

    2006-01-01

    In this Letter the impulsive synchronization of the Chen's hyperchaotic systems is discussed. Some new and sufficient conditions on varying impulsive distance are established in order to guarantee the synchronizabillity of the systems using the synchronization method. In particular, some simple conditions are derived in synchronizing the systems by equal impulsive distances. Two illustrative examples are provided to show the feasibility and the effectiveness of the proposed method. The boundaries of the stable regions are also estimated

  14. A True Open-Loop Synchronization Technique

    DEFF Research Database (Denmark)

    Golestan, Saeed; Vidal, Ana; Yepes, Alejandro G.

    2016-01-01

    Synchronization techniques can be broadly classified into two major categories: Closed-loop and open-loop methods. The open-loop synchronization (OLS) techniques, contrary to the closed-loop ones, are unconditionally stable and benefit from a fast dynamic response. Their performance, however, tends...... is to develop a true OLS (and therefore, unconditionally stable) technique without any need for the calculation of sine and cosine functions. The effectiveness of the proposed synchronization technique is confirmed through the simulation and experimental results....

  15. A single phase synchronous micromotor

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, T.

    1982-01-25

    The excitation winding of a synchronous micromotor, wound on a bobin made of an electricity insulating material (EIM), is located in a cylindrical mount, whose exterior walls are thicker than the interior ones. From above the mount is covered by a pole top with comb poles. The rotor poles are made of a permanent magnet, seated on a bushing which rotates on a shaft. The stable rotation of the rotor is supported by a stop bearing and a guide bearing, where the latter consists of a magnetic part and a nonmagnetic part.

  16. Synchronous Oscillations in Microtubule Polymerization

    Science.gov (United States)

    Carlier, M. F.; Melki, R.; Pantaloni, D.; Hill, T. L.; Chen, Y.

    1987-08-01

    Under conditions where microtubule nucleation and growth are fast (i.e., high magnesium ion and tubulin concentrations and absence of glycerol), microtubule assembly in vitro exhibits an oscillatory regime preceding the establishment of steady state. The amplitude of the oscillations can represent >50% of the maximum turbidity change and oscillations persist for up to 20 periods of 80 s each. Oscillations are accompanied by extensive length redistribution of microtubules. Preliminary work suggests that the oscillatory kinetics can be simulated using a model in which many microtubules undergo synchronous transitions between growing and rapidly depolymerizing phases, complicated by the kinetically limiting rate of nucleotide exchange on free tubulin.

  17. Seamless Image Mosaicking via Synchronization

    Science.gov (United States)

    Santellani, E.; Maset, E.; Fusiello, A.

    2018-05-01

    This paper proposes an innovative method to create high-quality seamless planar mosaics. The developed pipeline ensures good robustness against many common mosaicking problems (e.g., misalignments, colour distortion, moving objects, parallax) and differs from other works in the literature because a global approach, known as synchronization, is used for image registration and colour correction. To better conceal the mosaic seamlines, images are cut along specific paths, computed using a Voronoi decomposition of the mosaic area and a shortest path algorithm. Results obtained on challenging real datasets show that the colour correction mitigates significantly the colour variations between the original images and the seams on the final mosaic are not evident.

  18. Efficient Synchronization Primitives for GPUs

    OpenAIRE

    Stuart, Jeff A.; Owens, John D.

    2011-01-01

    In this paper, we revisit the design of synchronization primitives---specifically barriers, mutexes, and semaphores---and how they apply to the GPU. Previous implementations are insufficient due to the discrepancies in hardware and programming model of the GPU and CPU. We create new implementations in CUDA and analyze the performance of spinning on the GPU, as well as a method of sleeping on the GPU, by running a set of memory-system benchmarks on two of the most common GPUs in use, the Tesla...

  19. A hash based mutual RFID tag authentication protocol in telecare medicine information system.

    Science.gov (United States)

    Srivastava, Keerti; Awasthi, Amit K; Kaul, Sonam D; Mittal, R C

    2015-01-01

    Radio Frequency Identification (RFID) is a technology which has multidimensional applications to reduce the complexity of today life. Everywhere, like access control, transportation, real-time inventory, asset management and automated payment systems etc., RFID has its enormous use. Recently, this technology is opening its wings in healthcare environments, where potential applications include patient monitoring, object traceability and drug administration systems etc. In this paper, we propose a secure RFID-based protocol for the medical sector. This protocol is based on hash operation with synchronized secret. The protocol is safe against active and passive attacks such as forgery, traceability, replay and de-synchronization attack.

  20. Synchronization of coupled metronomes on two layers

    Science.gov (United States)

    Zhang, Jing; Yu, Yi-Zhen; Wang, Xin-Gang

    2017-12-01

    Coupled metronomes serve as a paradigmatic model for exploring the collective behaviors of complex dynamical systems, as well as a classical setup for classroom demonstrations of synchronization phenomena. Whereas previous studies of metronome synchronization have been concentrating on symmetric coupling schemes, here we consider the asymmetric case by adopting the scheme of layered metronomes. Specifically, we place two metronomes on each layer, and couple two layers by placing one on top of the other. By varying the initial conditions of the metronomes and adjusting the friction between the two layers, a variety of synchronous patterns are observed in experiment, including the splay synchronization (SS) state, the generalized splay synchronization (GSS) state, the anti-phase synchronization (APS) state, the in-phase delay synchronization (IPDS) state, and the in-phase synchronization (IPS) state. In particular, the IPDS state, in which the metronomes on each layer are synchronized in phase but are of a constant phase delay to metronomes on the other layer, is observed for the first time. In addition, a new technique based on audio signals is proposed for pattern detection, which is more convenient and easier to apply than the existing acquisition techniques. Furthermore, a theoretical model is developed to explain the experimental observations, and is employed to explore the dynamical properties of the patterns, including the basin distributions and the pattern transitions. Our study sheds new lights on the collective behaviors of coupled metronomes, and the developed setup can be used in the classroom for demonstration purposes.

  1. Pilotless Frame Synchronization Using LDPC Code Constraints

    Science.gov (United States)

    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.

  2. Synchronization Analysis of the Supermarket Refrigeration System

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Chen, Liang; Larsen, Lars Finn Sloth

    2009-01-01

    is analyzed using the bifurcation and chaos theory. It is demonstrated that the system can have a complex chaotic behavior, which is far from the synchronization. This shows that making the system chaotic is a good choice for a de-synchronization strategy. The positive maximum Lyapunov exponent is usually...... taken as an indication of the existence of chaos. It is used in the paper as a measure of performance for the tendency of the system to synchronize, that is, the higher value of the maximum Lyapunov exponent the lower risk for synchronization....

  3. Acoustophoretic Synchronization of Mammalian Cells in Microchannels

    DEFF Research Database (Denmark)

    Thévoz, P.; Adams, J.D.; Shea, H.

    2010-01-01

    We report the first use of ultrasonic standing waves to achieve cell cycle phase synchronization in mammalian cells in a high-throughput and reagent-free manner. The acoustophoretic cell synchronization (ACS) device utilizes volume-dependent acoustic radiation force within a microchannel to selec......We report the first use of ultrasonic standing waves to achieve cell cycle phase synchronization in mammalian cells in a high-throughput and reagent-free manner. The acoustophoretic cell synchronization (ACS) device utilizes volume-dependent acoustic radiation force within a microchannel...

  4. Price synchronization in retailing: some empirical evidence

    Directory of Open Access Journals (Sweden)

    Marcelo Resende

    2014-06-01

    Full Text Available The paper investigates the synchronization of price changes in the context of retail tire dealers in São Paulo-Brazil and selected items in supermarkets for cleaning supplies and food in Rio de Janeiro-Brazil. Results indicate similar and non-negligible synchronization for different brands, although magnitudes are distant from a perfect synchronization pattern. We find interesting patterns in inter-firm competition, with similar magnitudes across different tire types. Intra-chain synchronization is substantial, indicating that a common price adjustment policy tends to be sustained for each chain across different products.

  5. Beyond protocols

    DEFF Research Database (Denmark)

    Vanderhoeven, Sonia; Branquart, Etienne; Casaer, Jim

    2017-01-01

    Risk assessment tools for listing invasive alien species need to incorporate all available evidence and expertise. Beyond the wealth of protocols developed to date, we argue that the current way of performing risk analysis has several shortcomings. In particular, lack of data on ecological impact...... information on risk and the exploration of improved methods for decision making on biodiversity management. This is crucial for efficient conservation resource allocation and uptake by stakeholders and the public......., transparency and repeatability of assessments as well as the incorporation of uncertainty should all be explicitly considered. We recommend improved quality control of risk assessments through formalized peer review with clear feedback between assessors and reviewers. Alternatively, a consensus building...

  6. IEEE 1588 Time Synchronization Board in MTCA.4 Form Factor

    Science.gov (United States)

    Jabłoński, G.; Makowski, D.; Mielczarek, A.; Orlikowski, M.; Perek, P.; Napieralski, A.; Makijarvi, P.; Simrock, S.

    2015-06-01

    Distributed data acquisition and control systems in large-scale scientific experiments, like e.g. ITER, require time synchronization with nanosecond precision. A protocol commonly used for that purpose is the Precise Timing Protocol (PTP), also known as IEEE 1588 standard. It uses the standard Ethernet signalling and protocols and allows obtaining timing accuracy of the order of tens of nanoseconds. The MTCA.4 is gradually becoming the platform of choice for building such systems. Currently there is no commercially available implementation of the PTP receiver on that platform. In this paper, we present a module in the MTCA.4 form factor supporting this standard. The module may be used as a timing receiver providing reference clocks in an MTCA.4 chassis, generating a Pulse Per Second (PPS) signal and allowing generation of triggers and timestamping of events on 8 configurable backplane lines and two front panel connectors. The module is based on the Xilinx Spartan 6 FPGA and thermally stabilized Voltage Controlled Oscillator controlled by the digital-to-analog converter. The board supports standalone operation, without the support from the host operating system, as the entire control algorithm is run on a Microblaze CPU implemented in the FPGA. The software support for the card includes the low-level API in the form of Linux driver, user-mode library, high-level API: ITER Nominal Device Support and EPICS IOC. The device has been tested in the ITER timing distribution network (TCN) with three cascaded PTP-enabled Hirschmann switches and a GPS reference clock source. An RMS synchronization accuracy, measured by direct comparison of the PPS signals, better than 20 ns has been obtained.

  7. Differential expression of secretogranin II and chromogranin A genes in the female rat pituitary through sexual maturation and estrous cycle

    International Nuclear Information System (INIS)

    Anouar, Y.; Duval, J.

    1991-01-01

    Secretogranin II (SgII) is a protein of pituitary secretory granules released by LHRH-stimulated gonadotrope cells. Estrogens and androgens are modulators of SgII release. Experiments were performed to determine the regulation of expression of the SgII gene in the female rat pituitary, during sexual maturation and according to the estrous cycle. Age- and cycle-related changes in SgII mRNA content were estimated through cytoplasmic slot blot; SgII content was determined by western blotting; maturation of the protein was controlled through [35S]sulfate labeling. Variations in chromogranin A (CgA), another protein of secretory granules, were analyzed in the same experimental conditions to assess the specificity of SgII regulation. The pituitary SgII concentration increased between days 7 and 21 (2.2-fold) and then declined to the initial 7-day-old value. Simultaneously, the CgA concentration went through a maximum between days 14 and 21 and then strongly dropped to barely detectable levels in the adult pituitary. The SgII mRNA concentration followed roughly the same pattern as the protein. Moreover, the sulfation level remained constant between days 14 and 60. These results demonstrated a regulatory mechanism operating, during sexual maturation, on the SgII gene and not on the protein processing or on storage/release steps. In the 4-day cycling females, the pituitary SgII mRNA and protein contents were the lowest during estrus. They then increased to their highest values in diestrus II. Moreover, the sulfation level of SgII was significantly higher during estrus than during any other stage. Due to its low content level, variations in pituitary CgA could not be demonstrated during the cycle

  8. Diet-induced obesity reduces core body temperature across the estrous cycle and pregnancy in the rat.

    Science.gov (United States)

    Crew, Rachael C; Waddell, Brendan J; Maloney, Shane K; Mark, Peter J

    2018-04-16

    Obesity during pregnancy causes adverse maternal and fetal health outcomes and programs offspring for adult-onset diseases, including cardiovascular disease. Obesity also disrupts core body temperature (T c ) regulation in nonpregnant rodents; however, it is unknown whether obesity alters normal maternal T c adaptations to pregnancy. Since T c is influenced by the circadian system, and both obesity and pregnancy alter circadian biology, it was hypothesized that obesity disrupts the normal rhythmic patterns of T c before and during gestation. Obesity was induced by cafeteria (CAF) feeding in female Wistar rats for 8 weeks prior to and during gestation, whereas control (CON) animals had free access to chow. Intraperitoneal temperature loggers measured daily T c profiles throughout the study, while maternal body composition and leptin levels were assessed near term. Daily temperature profiles were examined for rhythmic features (mesor, amplitude and acrophase) by cosine regression analysis. CAF animals exhibited increased fat mass (93%) and associated hyperleptinemia (3.2-fold increase) compared to CON animals. CAF consumption reduced the average T c (by up to 0.29°C) across the estrous cycle and most of pregnancy; however, T c for CAF and CON animals converged toward the end of gestation. Obesity reduced the amplitude of T c rhythms at estrus and proestrus and on day 8 of pregnancy, but increased the amplitude at day 20 of pregnancy. Photoperiod analysis revealed that obesity reduced T c exclusively in the light period during pre-pregnancy but only during the dark period in late gestation. In conclusion, obesity alters rhythmic T c profiles and reduces the magnitude of the T c decline late in rat gestation, which may have implications for maternal health and fetal development.

  9. Expression of estrogen receptor α 36 (ESR36) in the hamster ovary throughout the estrous cycle: effects of gonadotropins.

    Science.gov (United States)

    Chakraborty, Prabuddha; Roy, Shyamal K

    2013-01-01

    Estradiol-17β (E) plays an important role in ovarian follicular development. Evidence indicates that some of the effect of E is mediated by the transmembrane estrogen receptor. In this study, we examined the spatio-temporal expression of recently discovered ERα36 (ESR36), a splice variant of Esr1 and a receptor for non-genomic E signaling, in the hamster ovary during the estrous cycle and the role of gonadotropins and ovarian steroid hormones in ESR36 expression. ESR36 expression was high on estrus (D1:0900 h) and declined precipitously by proestrus (D4:0900 h) and remained low up to D4:1600 h. Immunofluorescence findings corroborated immunoblot findings and revealed that ESR36 was expressed only in the cell membrane of both follicular and non-follicular cells, except the oocytes. Ovarian ESR36 was capable of binding to the E-affinity matrix, and have different molecular weight than that of the ESR1 or GPER. Hypophysectomy (Hx) resulted in a marked decline in ESR36 protein levels. FSH and LH, alone or combined, markedly upregulated ESR36 protein in Hx hamsters to the levels observed in D1 hamsters, but neither E nor P had any effect. Inhibition of the gonadotropin surge by phenobarbital treatment on D4:1100 h attenuated ESR36 expression in D1:0900 h ovaries, but the decline was restored by either FSH or LH replacement on D4 afternoon. This is the first report to show that ESR36, which is distinct from ESR1 or GPER is expressed in the plasma membrane of ovarian follicular and non-follicular cells, binds to E and its expression is regulated directly by the gonadotropins. In light of our previous findings, the results suggest that ovarian cells contain at least two distinct membrane estrogen receptors, such as GPER and ESR36, and strongly suggest for a non-genomic action of E regulating ovarian follicular functions.

  10. Working and reference memory across the estrous cycle of rat: a long-term study in gonadally intact females.

    Science.gov (United States)

    Pompili, Assunta; Tomaz, Carlos; Arnone, Benedetto; Tavares, Maria Clotilde; Gasbarri, Antonella

    2010-11-12

    The results of many studies conducted over the past two decades suggested a role of estrogen on mammal's ability to learn and remember. In the present paper, we analyzed the influence that the endogenous fluctuation of estrogen, naturally present across the different phases of estrous cycle of female rats, can exert over the performance of tasks utilized to assess memory. In particular, we analyzed the performances in an eight arms radial maze task, dependent upon working memory, and in a water maze (WM) task, dependent upon spatial reference memory. The water maze is aversively motivated by the desire to escape onto a safe platform, whereas the radial arm maze (RAM) is motivated by food reward. The difference in reinforcement may affect the speed of learning, the strategy adopted and the necessity for accurate navigation. Therefore, coherent results obtained through the two different tasks can be due to mnemonic factors. The study was conducted during a long period of time, 14 months, utilizing gonadally intact females, without pharmacological and surgical treatments. In order to evaluate the post-acquisition phase we first trained the animals to reach the criterion in performing tasks, and then we submitted them to experimental phase. Our results show that estrogen can have an effect on memory processes, and that this effect may be different in relation to different kinds of memory. In fact, in our study, estrogen selectively improved working memory, but not reference memory, during post-acquisition performance of a RAM task with four baited and four un-baited arms. Moreover, WM performances showed that estrogen have a negative effect on spatial reference memory. (c) 2010 Elsevier B.V. All rights reserved.

  11. Measuring virgin female aggression in the female intruder test (FIT): effects of oxytocin, estrous cycle, and anxiety.

    Science.gov (United States)

    de Jong, Trynke R; Beiderbeck, Daniela I; Neumann, Inga D

    2014-01-01

    The costs of violence and aggression in our society have stimulated the scientific search for the predictors and causes of aggression. The majority of studies have focused on males, which are considered to be more aggressive than females in most species. However, rates of offensive behavior in girls and young women are considerable and are currently rising in Western society. The extrapolation of scientific results from males to young, non-maternal females is a priori limited, based on the profound sex differences in brain areas and functioning of neurotransmitters involved in aggression. Therefore, we established a paradigm to assess aggressive behavior in young virgin female rats, i.e. the female intruder test (FIT). We found that approximately 40% of un-manipulated adult (10-11 weeks old) female Wistar rats attack an intruder female during the FIT, independent of their estrous phase or that of their intruder. In addition, adolescent (7-8 weeks old) female rats selected for high anxiety behavior (HABs) displayed significantly more aggression than non-selected (NAB) or low-anxiety (LAB) rats. Intracerebroventricular infusion of oxytocin (OXT, 0.1 µg/5 µl) inhibited aggressive behavior in adult NAB and LAB, but not HAB females. Adolescent NAB rats that had been aggressive towards their intruder showed increased pERK immunoreactivity (IR) in the hypothalamic attack area and reduced pERK-IR in OXT neurons in the paraventricular hypothalamic nucleus compared to non-aggressive NAB rats. Taken together, aggressive behavior in young virgin female rats is partly dependent on trait anxiety, and appears to be under considerable OXT control.

  12. Measuring virgin female aggression in the female intruder test (FIT: effects of oxytocin, estrous cycle, and anxiety.

    Directory of Open Access Journals (Sweden)

    Trynke R de Jong

    Full Text Available The costs of violence and aggression in our society have stimulated the scientific search for the predictors and causes of aggression. The majority of studies have focused on males, which are considered to be more aggressive than females in most species. However, rates of offensive behavior in girls and young women are considerable and are currently rising in Western society. The extrapolation of scientific results from males to young, non-maternal females is a priori limited, based on the profound sex differences in brain areas and functioning of neurotransmitters involved in aggression. Therefore, we established a paradigm to assess aggressive behavior in young virgin female rats, i.e. the female intruder test (FIT. We found that approximately 40% of un-manipulated adult (10-11 weeks old female Wistar rats attack an intruder female during the FIT, independent of their estrous phase or that of their intruder. In addition, adolescent (7-8 weeks old female rats selected for high anxiety behavior (HABs displayed significantly more aggression than non-selected (NAB or low-anxiety (LAB rats. Intracerebroventricular infusion of oxytocin (OXT, 0.1 µg/5 µl inhibited aggressive behavior in adult NAB and LAB, but not HAB females. Adolescent NAB rats that had been aggressive towards their intruder showed increased pERK immunoreactivity (IR in the hypothalamic attack area and reduced pERK-IR in OXT neurons in the paraventricular hypothalamic nucleus compared to non-aggressive NAB rats. Taken together, aggressive behavior in young virgin female rats is partly dependent on trait anxiety, and appears to be under considerable OXT control.

  13. Synchronization of random bit generators based on coupled chaotic lasers and application to cryptography.

    Science.gov (United States)

    Kanter, Ido; Butkovski, Maria; Peleg, Yitzhak; Zigzag, Meital; Aviad, Yaara; Reidler, Igor; Rosenbluh, Michael; Kinzel, Wolfgang

    2010-08-16

    Random bit generators (RBGs) constitute an important tool in cryptography, stochastic simulations and secure communications. The later in particular has some difficult requirements: high generation rate of unpredictable bit strings and secure key-exchange protocols over public channels. Deterministic algorithms generate pseudo-random number sequences at high rates, however, their unpredictability is limited by the very nature of their deterministic origin. Recently, physical RBGs based on chaotic semiconductor lasers were shown to exceed Gbit/s rates. Whether secure synchronization of two high rate physical RBGs is possible remains an open question. Here we propose a method, whereby two fast RBGs based on mutually coupled chaotic lasers, are synchronized. Using information theoretic analysis we demonstrate security against a powerful computational eavesdropper, capable of noiseless amplification, where all parameters are publicly known. The method is also extended to secure synchronization of a small network of three RBGs.

  14. Thymosin-∞1 in the ovary and the levels of thymosin-∞1 and T lymphocytes during estrous cycle in swine

    International Nuclear Information System (INIS)

    Vakharia, D.D.; Kinder, J.E.; Wise, T.H.

    1986-01-01

    Experimental evidence in rodents has emphasized the role of thymic hormones, particularly thymosin-α 1 (ThA1), thymosin-β 4 and T lymphocytes, in regulation of ovarian development. Similar information is unavailable for farm animals including swine. Serum and follicular fluid (FF) ThA1 levels and percentage of peripheral blood (PB) T lymphocyte population during different phases of the estrous cycle were determined. T lymphocytes in PB were enumerated by the sheep erythrocyte rosette test. Percentage of T lymphocyte population at both early luteal (EL) and mid luteal phases (ML) were significantly (P<0.01) higher than during late luteal phase (LL). ThA1 measured by radioimmunoassay in FF of follicles of diameter <8 mm was significantly (P<0.01) higher than serum levels. Culture supernatants of corpus luteum (CL) and cells derived from follicles of diameter <8 mm (CF) contained significant amounts of ThA1 suggesting release of ThA1 from CL and CF. Germinal epithelium, follicular basal membrane, theca cells, granulosa cells and cells in CL stained positive for ThA1 by immunofluorescence test. Gilt estrous cycle phase was determined either by observing ovary morphology or counting the days after estrous. ThA1 levels in follicular fluid were significantly (P<0.01) higher during luteal phase than during follicular phase. Levels during ML or LL were significantly (P<0.01) higher than EL. ThA1 secreted by ovary may have a regulatory role in cyclicity of gilts and follicle development

  15. EFFECT OF POST-MATING GNRH TREATMET ON SERUM PROGESTERONE, LUTEINIZING HORMONE LEVELS, DURATION OF ESTROUS CYCLE AND PREGNANCY RATES IN COWS

    Directory of Open Access Journals (Sweden)

    H. YILDIZ, E. KAYGUSUZOĞLU, M. KAYA1 AND M. ÇENESIZ1

    2009-07-01

    Full Text Available Pregnancy rate, estrous cycle lenght, serum progesterone and luteinizing hormone (LH concentrations were determined in gonadotropin releasing hormone (GnRH; 10.5 μg synthetic gonadotrophin releasing hormone agonist, receptal administered cows on day 12 post-mating (n=9 compared to control cows (n=8. Their oestrous cycles were synchronised by intramuscular administration of prostaglandin F2 alpha (its analog, cloprostenol twice at 11 days interval. Estrous exhibited cows were mated naturally. Blood samples were collected every two days from all animals. Serum progesterone and LH concentrations were measured by ELISA method. GnRH administration significantly increased serum LH concentration which reached peak levels 2-3 h after treatment. However, serum progesterone concentration was not affected. There were no differences in mean progesterone concentrations on days 12 to 24 post-mating between GnRH administrated and control pregnant cows. However, in non pregnant animals, progesterone concentrations on days 16 in the treated group were lower than control group (P<0.01. Pregnancy diagnosis in animals made by B-mode ultrasonography between the 30th and 35th day showed that 77.7% of treated cows were pregnant compared to 50% in control group. Duration of the estrous cycle in the non-pregnant animals was not affected by the treatment (control, 21.3 ± 0.8 days; treated, 22.5 ± 0.5 days. In conclusion, this study supports the use of GnRH on day 12 post-mating as a method for enhancing pregnancy rates in lactating dairy cattle.

  16. Comparison of follicular dynamics, superovulatory response, and embryo recovery between estradiol based and conventional superstimulation protocol in buffaloes (Bubalus bubalis

    Directory of Open Access Journals (Sweden)

    Narinder Singh

    2015-08-01

    Full Text Available Aim: To evaluate the follicular dynamics, superovulatory response, and embryo recovery following superstimulatory treatment initiated at estradiol-17β induced follicular wave emergence and its comparison with conventional superstimulatory protocol in buffaloes. Materials and Methods: Six normal cycling pluriparous buffaloes, lactating, 90-180 days post-partum, and weighing between 500 and 660 kg were superstimulated twice with a withdrawal period of 35 days in between two treatments. In superstimulation protocol-1 (estradiol group buffaloes were administered estradiol-17β (2 mg, i.m. and eazibreed controlled internal drug release (CIDR was inserted intravaginally (day=0 at the random stage of the estrous cycle. On the day 4, buffaloes were superstimulated using follicle stimulating hormone (FSH 400 mg, divided into 10 tapering doses given at 12 hourly intervals. Prostaglandin F2α analogs (PGF2α was administered at day 7.5 and day 8, and CIDR was removed with the second PGF2α injection. In superstimulation protocol - 2 (conventional group buffaloes were superstimulated on the 10th day of the estrous cycle with same FSH dose regimen and similar timings for PGF2α injections. In both groups, half of the buffaloes were treated with luteinizing hormone (LH 25 mg and other half with 100 ug buserelin; gonadotrophin releasing hormone (GnRH analog at 12 h after the end of FSH treatment. All buffaloes in both protocols were inseminated twice at 12 and 24 h of LH/GnRH treatment. Daily ultrasonography was performed to record the size and number of follicles and superovulatory response. Results: Significantly higher number of small follicles (8 mm, corpora lutea, and transferable embryos was higher in buffaloes superstimulated at estradiol-induced follicular wave compared to the conventional protocol: Further the percentage of transferable embryos was significantly higher in buffaloes administered with LH compared to GnRH.

  17. Stable Density and Dynamics of Dendritic Spines of Cortical Neurons Across the Estrous Cycle While Expressing Differential Levels of Sensory-Evoked Plasticity

    Directory of Open Access Journals (Sweden)

    Bailin H. Alexander

    2018-03-01

    Full Text Available Periodic oscillations of gonadal hormone levels during the estrous cycle exert effects on the female brain, impacting cognition and behavior. While previous research suggests that changes in hormone levels across the cycle affect dendritic spine dynamics in the hippocampus, little is known about the effects on cortical dendritic spines and previous studies showed contradictory results. In this in vivo imaging study, we investigated the impact of the estrous cycle on the density and dynamics of dendritic spines of pyramidal neurons in the primary somatosensory cortex of mice. We also examined if the induction of synaptic plasticity during proestrus, estrus, and metestrus/diestrus had differential effects on the degree of remodeling of synapses in this brain area. We used chronic two-photon excitation (2PE microscopy during steady-state conditions and after evoking synaptic plasticity by whisker stimulation at the different stages of the cycle. We imaged apical dendritic tufts of layer 5 pyramidal neurons of naturally cycling virgin young female mice. Spine density, turnover rate (TOR, survival fraction, morphology, and volume of mushroom spines remained unaltered across the estrous cycle, and the values of these parameters were comparable with those of young male mice. However, while whisker stimulation of female mice during proestrus and estrus resulted in increases in the TOR of spines (74.2 ± 14.9% and 75.1 ± 12.7% vs. baseline, respectively, sensory-evoked plasticity was significantly lower during metestrus/diestrus (32.3 ± 12.8%. In males, whisker stimulation produced 46.5 ± 20% increase in TOR compared with baseline—not significantly different from female mice at any stage of the cycle. These results indicate that, while steady-state density and dynamics of dendritic spines of layer 5 pyramidal neurons in the primary somatosensory cortex of female mice are constant during the estrous cycle, the susceptibility of these neurons to

  18. Estrous cycle dependent fluctuations of regulatory neuropeptides in the lower urinary tract of female rats upon colon-bladder cross-sensitization.

    Directory of Open Access Journals (Sweden)

    Xiao-Qing Pan

    Full Text Available Co-morbidity of bladder, bowel, and non-specific pelvic pain symptoms is highly prevalent in women. Little evidence is present on modulation of pelvic pain syndromes by sex hormones, therefore, the objective of this study was to clarify the effects of hormonal fluctuations within the estrous cycle on regulatory neuropeptides in female rats using a model of neurogenic bladder dysfunction. The estrous cycle in female rats (Sprague-Dawley, 230-250 g was assessed by vaginal smears and weight of uterine horns. Neurogenic bladder dysfunction was induced by a single inflammatory insult to the distal colon. Protein expression of calcitonin gene related peptide (CGRP, substance P (SP, nerve growth factor (NGF, and brain derived neurotrophic factor (BDNF in the pelvic organs, sensory ganglia and lumbosacral spinal cord was compared in rats in proestrus (high estrogen vs diestrus (low estrogen. Under normal physiological conditions, concentration of SP and CGRP was similar in the distal colon and urinary bladder during all phases of the estrous cycle, however, acute colitis induced a significant up-regulation of CGRP content in the colon (by 63% and urinary bladder (by 54%, p≤0.05 to control of rats in proestrus. These changes were accompanied by a significant diminution of CGRP content in L6-S2 DRG after colonic treatment, likely associated with its release in the periphery. In rats with high estrogen at the time of testing (proestrus, experimental colitis caused a significant up-regulation of BDNF colonic content from 26.1±8.5 pg/ml to 83.4±32.5 pg/ml (N = 7, p≤0.05 to control and also induced similar effects on BDNF in the urinary bladder which was also up-regulated by 5-fold in rats in proestrus (p≤0.05 to respective control. Our results demonstrate estrous cycle dependent fluctuations of regulatory neuropeptides in the lower urinary tract upon colon-bladder cross-sensitization, which may contribute to pain fluctuations in female patients

  19. Impulsive Synchronization and Adaptive-Impulsive Synchronization of a Novel Financial Hyperchaotic System

    Directory of Open Access Journals (Sweden)

    Xiuli Chai

    2013-01-01

    Full Text Available The impulsive synchronization and adaptive-impulsive synchronization of a novel financial hyperchaotic system are investigated. Based on comparing principle for impulsive functional differential equations, several sufficient conditions for impulsive synchronization are derived, and the upper bounds of impulsive interval for stable synchronization are estimated. Furthermore, a nonlinear adaptive-impulsive control scheme is designed to synchronize the financial system using invariant principle of impulsive dynamical systems. Moreover, corresponding numerical simulations are presented to illustrate the effectiveness and feasibility of the proposed methods.

  20. Synchronization of coupled chaotic dynamics on networks

    Indian Academy of Sciences (India)

    We review some recent work on the synchronization of coupled dynamical systems on a variety of networks. When nodes show synchronized behaviour, two interesting phenomena can be observed. First, there are some nodes of the floating type that show intermittent behaviour between getting attached to some clusters ...

  1. Synchronization and emergence in complex systems

    Indian Academy of Sciences (India)

    ... complex systems. Fatihcan M Atay. Synchronization, Coupled Systems and Networks Volume 77 Issue 5 November 2011 pp 855-863 ... We show how novel behaviour can emerge in complex systems at the global level through synchronization of the activities of their constituent units. Two mechanisms are suggested for ...

  2. Dependence of synchronization frequency of Kuramoto oscillators ...

    Indian Academy of Sciences (India)

    Kuramoto oscillators have been proposed earlier as a model for interacting systems that exhibit synchronization. In this article, we study the difference between networks with symmetric and asymmetric distribution of natural frequencies. We first indicate that synchronization frequency of oscillators in a completely connected ...

  3. Synchronization of oscillators in complex networks

    Indian Academy of Sciences (India)

    Theory of identical or complete synchronization of identical oscillators in arbitrary networks is introduced. In addition, several graph theory concepts and results that augment the synchronization theory and a tie in closely to random, semirandom, and regular networks are introduced. Combined theories are used to explore ...

  4. Synchronized Data Aggregation for Wireless Sensor Network

    DEFF Research Database (Denmark)

    Dnyaneshwar, Mantri; Prasad, Neeli R.; Prasad, Ramjee

    2014-01-01

    Wireless Sensor Networks (WSNs) are used for monitoring and data collection purposes. A key challenge in effective data collection is to schedule and synchronize the activities of the nodes with global clock. This paper proposes the Synchronized Data Aggregation Algorithm (SDA) using spanning tree...

  5. A clock synchronization skeleton based on RTAI

    NARCIS (Netherlands)

    Huang, Y.; Visser, P.M.; Broenink, Johannes F.

    2006-01-01

    This paper presents a clock synchronization skeleton based on RTAI (Real Time Application Interface). The skeleton is a thin layer that provides unified but extendible interfaces to the underlying operating system, the synchronization algorithms and the upper level applications in need of clock

  6. Analytical treatment for synchronizing chaos through unidirectional ...

    Indian Academy of Sciences (India)

    Abstract. The idea of synchronization can be explicitly demonstrated by both numerical and ana- lytical means on a nonlinear electronic circuit. Also, we introduce a scheme to obtain various logic gate structures, using synchronization of chaotic systems. By a small change in the response param- eter of unidirectionally ...

  7. Synchronization of oscillators in complex networks

    Indian Academy of Sciences (India)

    Abstract. Theory of identical or complete synchronization of identical oscillators in arbitrary networks is introduced. In addition, several graph theory concepts and results that augment the synchronization theory and a tie in closely to random, semirandom, and regular networks are introduced. Combined theories are used to ...

  8. Identical synchronization of coupled Rossler systems

    DEFF Research Database (Denmark)

    Yanchuk, S.; Maistrenko, Y.; Mosekilde, Erik

    1999-01-01

    Analyzing the transverse stability of low periodic orbits embedded in the synchronized chaotic state for a system of two coupled Rössler oscillators, we obtain the conditions for synchronization and determine the coupling parameters for which riddled basins of attraction may arise. It is shown how...

  9. Chaos synchronization of nonlinear Bloch equations

    International Nuclear Information System (INIS)

    Park, Ju H.

    2006-01-01

    In this paper, the problem of chaos synchronization of Bloch equations is considered. A novel nonlinear controller is designed based on the Lyapunov stability theory. The proposed controller ensures that the states of the controlled chaotic slave system asymptotically synchronizes the states of the master system. A numerical example is given to illuminate the design procedure and advantage of the result derived

  10. Communicating via robust synchronization of chaotic lasers

    International Nuclear Information System (INIS)

    Lopez-Gutierrez, R.M.; Posadas-Castillo, C.; Lopez-Mancilla, D.; Cruz-Hernandez, C.

    2009-01-01

    In this paper, the robust synchronization problem for coupled chaotic Nd:YAG lasers is addressed. We resort to complex systems theory to achieve chaos synchronization. Based on stability theory, it is shown that the state trajectories of the perturbed error synchronization are ultimately bounded, provided the unperturbed synchronization error system is exponentially stable, and some conditions on the bounds of the perturbation terms are satisfied. So that, encoding, transmission, and decoding in chaotic optical communications are presented. We analyze the transmission and recovery of encrypted information when parameter mismatches are considered. Computer simulations are provided to show the effectiveness of this robustness synchronization property, we present the encrypted transmission of image messages, and we show that, the transmitted image is faithfully recovered.

  11. Communicating via robust synchronization of chaotic lasers

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Gutierrez, R.M. [Engineering Faculty, Baja California Autonomous University (UABC), Km. 103 Carret. Tij-Ens., 22860 Ensenada, B.C. (Mexico); Posadas-Castillo, C. [Engineering Faculty, Baja California Autonomous University (UABC), Km. 103 Carret. Tij-Ens., 22860 Ensenada, B.C. (Mexico); FIME, Autonomous University of Nuevo Leon (UANL), Pedro de Alba, S.N., Cd. Universitaria, San Nicolas de los Garza, NL (Mexico); Lopez-Mancilla, D. [Departamento de Ciencias Exactas y Tecnologicas, Centro Universitario de los Lagos, Universidad de Guadalajara (CULagos-UdeG), Enrique Diaz de Leon s/n, 47460 Lagos de Moreno, Jal. (Mexico); Cruz-Hernandez, C. [Electronics and Telecommunications Department, Scientific Research and Advanced Studies of Ensenada (CICESE), Km. 107 Carret. Tij-Ens., 22860 Ensenada, B.C. (Mexico)], E-mail: ccruz@cicese.mx

    2009-10-15

    In this paper, the robust synchronization problem for coupled chaotic Nd:YAG lasers is addressed. We resort to complex systems theory to achieve chaos synchronization. Based on stability theory, it is shown that the state trajectories of the perturbed error synchronization are ultimately bounded, provided the unperturbed synchronization error system is exponentially stable, and some conditions on the bounds of the perturbation terms are satisfied. So that, encoding, transmission, and decoding in chaotic optical communications are presented. We analyze the transmission and recovery of encrypted information when parameter mismatches are considered. Computer simulations are provided to show the effectiveness of this robustness synchronization property, we present the encrypted transmission of image messages, and we show that, the transmitted image is faithfully recovered.

  12. Synchronization in networks with heterogeneous coupling delays

    Science.gov (United States)

    Otto, Andreas; Radons, Günter; Bachrathy, Dániel; Orosz, Gábor

    2018-01-01

    Synchronization in networks of identical oscillators with heterogeneous coupling delays is studied. A decomposition of the network dynamics is obtained by block diagonalizing a newly introduced adjacency lag operator which contains the topology of the network as well as the corresponding coupling delays. This generalizes the master stability function approach, which was developed for homogenous delays. As a result the network dynamics can be analyzed by delay differential equations with distributed delay, where different delay distributions emerge for different network modes. Frequency domain methods are used for the stability analysis of synchronized equilibria and synchronized periodic orbits. As an example, the synchronization behavior in a system of delay-coupled Hodgkin-Huxley neurons is investigated. It is shown that the parameter regions where synchronized periodic spiking is unstable expand when increasing the delay heterogeneity.

  13. Chaos synchronization based on intermittent state observer

    Institute of Scientific and Technical Information of China (English)

    Li Guo-Hui; Zhou Shi-Ping; Xu De-Ming

    2004-01-01

    This paper describes the method of synchronizing slave to the master trajectory using an intermittent state observer by constructing a synchronizer which drives the response system globally tracing the driving system asymptotically. It has been shown from the theory of synchronization error-analysis that a satisfactory result of chaos synchronization is expected under an appropriate intermittent period and state observer. Compared with continuous control method,the proposed intermittent method can target the desired orbit more efficiently. The application of the method is demonstrated on the hyperchaotic Rossler systems. Numerical simulations show that the length of the synchronization interval rs is of crucial importance for our scheme, and the method is robust with respect to parameter mismatch.

  14. Effects of frustration on explosive synchronization

    Science.gov (United States)

    Huang, Xia; Gao, Jian; Sun, Yu-Ting; Zheng, Zhi-Gang; Xu, Can

    2016-12-01

    In this study, we consider the emergence of explosive synchronization in scale-free networks by considering the Kuramoto model of coupled phase oscillators. The natural frequencies of oscillators are assumed to be correlated with their degrees and frustration is included in the system. This assumption can enhance or delay the explosive transition to synchronization. Interestingly, a de-synchronization phenomenon occurs and the type of phase transition is also changed. Furthermore, we provide an analytical treatment based on a star graph, which resembles that obtained in scale-free networks. Finally, a self-consistent approach is implemented to study the de-synchronization regime. Our findings have important implications for controlling synchronization in complex networks because frustration is a controllable parameter in experiments and a discontinuous abrupt phase transition is always dangerous in engineering in the real world.

  15. A precise time synchronization method for 5G based on radio-over-fiber network with SDN controller

    Science.gov (United States)

    He, Linkuan; Wei, Baoguo; Yang, Hui; Yu, Ao; Wang, Zhengyong; Zhang, Jie

    2018-02-01

    There is an increasing demand on accurate time synchronization with the growing bandwidth of network service for 5G. In 5G network, it's necessary for base station to achieve accurate time synchronization to guarantee the quality of communication. In order to keep accuracy time for 5G network, we propose a time synchronization system for satellite ground station based on radio-over-fiber network (RoFN) with software defined optical network (SDON) controller. The advantage of this method is to improve the accuracy of time synchronization of ground station. The IEEE 1588 time synchronization protocol can solve the problems of high cost and lack of precision. However, in the process of time synchronization, distortion exists during the transmission of digital time signal. RoF uses analog optical transmission links and therefore analog transmission can be implemented among ground stations instead of digital transmission, which means distortion and bandwidth waste in the process of digital synchronization can be avoided. Additionally, the thought of SDN, software defined network, can optimize RoFN with centralized control and simplifying base station. Related simulation had been carried out to prove its superiority.

  16. Variance based OFDM frame synchronization

    Directory of Open Access Journals (Sweden)

    Z. Fedra

    2012-04-01

    Full Text Available The paper deals with a new frame synchronization scheme for OFDM systems and calculates the complexity of this scheme. The scheme is based on the computing of the detection window variance. The variance is computed in two delayed times, so a modified Early-Late loop is used for the frame position detection. The proposed algorithm deals with different variants of OFDM parameters including guard interval, cyclic prefix, and has good properties regarding the choice of the algorithm's parameters since the parameters may be chosen within a wide range without having a high influence on system performance. The verification of the proposed algorithm functionality has been performed on a development environment using universal software radio peripheral (USRP hardware.

  17. Concurrent systems and time synchronization

    Science.gov (United States)

    Burgin, Mark; Grathoff, Annette

    2018-05-01

    In the majority of scientific fields, system dynamics is described assuming existence of unique time for the whole system. However, it is established theoretically, for example, in relativity theory or in the system theory of time, and validated experimentally that there are different times and time scales in a variety of real systems - physical, chemical, biological, social, etc. In spite of this, there are no wide-ranging scientific approaches to exploration of such systems. Therefore, the goal of this paper is to study systems with this property. We call them concurrent systems because processes in them can go, events can happen and actions can be performed in different time scales. The problem of time synchronization is specifically explored.

  18. Synchronization of world economic activity

    Science.gov (United States)

    Groth, Andreas; Ghil, Michael

    2017-12-01

    Common dynamical properties of business cycle fluctuations are studied in a sample of more than 100 countries that represent economic regions from all around the world. We apply the methodology of multivariate singular spectrum analysis (M-SSA) to identify oscillatory modes and to detect whether these modes are shared by clusters of phase- and frequency-locked oscillators. An extension of the M-SSA approach is introduced to help analyze structural changes in the cluster configuration of synchronization. With this novel technique, we are able to identify a common mode of business cycle activity across our sample, and thus point to the existence of a world business cycle. Superimposed on this mode, we further identify several major events that have markedly influenced the landscape of world economic activity in the postwar era.

  19. Using Integer Clocks to Verify the Timing-Sync Sensor Network Protocol

    Science.gov (United States)

    Huang, Xiaowan; Singh, Anu; Smolka, Scott A.

    2010-01-01

    We use the UPPAAL model checker for Timed Automata to verify the Timing-Sync time-synchronization protocol for sensor networks (TPSN). The TPSN protocol seeks to provide network-wide synchronization of the distributed clocks in a sensor network. Clock-synchronization algorithms for sensor networks such as TPSN must be able to perform arithmetic on clock values to calculate clock drift and network propagation delays. They must be able to read the value of a local clock and assign it to another local clock. Such operations are not directly supported by the theory of Timed Automata. To overcome this formal-modeling obstacle, we augment the UPPAAL specification language with the integer clock derived type. Integer clocks, which are essentially integer variables that are periodically incremented by a global pulse generator, greatly facilitate the encoding of the operations required to synchronize clocks as in the TPSN protocol. With this integer-clock-based model of TPSN in hand, we use UPPAAL to verify that the protocol achieves network-wide time synchronization and is devoid of deadlock. We also use the UPPAAL Tracer tool to illustrate how integer clocks can be used to capture clock drift and resynchronization during protocol execution

  20. Chaos synchronization between Chen system and Genesio system

    International Nuclear Information System (INIS)

    Wu Xianyong; Guan Zhihong; Wu Zhengping; Li Tao

    2007-01-01

    This Letter presents two synchronization schemes between two different chaotic systems. Active control synchronization and adaptive synchronization between Chen system and Genesio system are studied, different controllers are designed to synchronize the drive and response systems, active control synchronization is used when system parameters are known; adaptive synchronization is employed when system parameters are unknown or uncertain. Simulation results show the effectiveness of the proposed schemes

  1. Protocolos de produção in vitro de embriões na raça Gir In vitro embryo production protocols in Gir breed

    Directory of Open Access Journals (Sweden)

    A.A. Ramos

    2006-06-01

    Full Text Available Avaliaram-se os efeitos de dois protocolos de punção folicular na quantidade/qualidade dos oócitos e na produção in vitro de embriões, em vacas da raça Gir, não-lactantes. O ciclo estral foi sincronizado com cloprostenol e ao longo do experimento os animais receberam implantes auriculares de norgestomet, renovados a cada 14 dias. Os animais foram submetidos aos protocolos I (sem estimulação hormonal, com punção folicular duas vezes/semana e II (pré-tratamento com 250 UI de FSH em doses decrescentes, três dias antes da punção folicular. Os oócitos recuperados foram levados ao laboratório em meio TALP-Hepes e submetidos à maturação. Na fecundação in vitro utilizou-se sêmen de touro Gir, previamente capacitado. Após 22 horas de fecundação, os prováveis zigotos foram co-cultivados com células da granulosa em CR2aa acrescido de 10% de soro fetal bovino. A taxa de clivagem foi avaliada 72 horas pós-fecundação e a de blastocisto 192 horas pós-fecundação. O número total de folículos foi maior (P0,05. O número de oócitos de grau I e a taxa de clivagem foram maiores (PThe effect of two ovum pick-up protocols on amount/quality of oocytes retrived and on in vitro embryo production of Gyr cows was evaluated in non-lactating cycling cows with good body and reproductive conditions. Estrous cycles were synchronized with cloprostenol. During the experiment, animals received norgestomet ear implants, replaced every 14 days. Animals were submitted to protocol I (without hormonal estimulation and protocol II (pre-stimulation with 250 IU of FSH three days before aspiration. Recovered oocytes were transported in Talp-Hepes to the laboratory, classified and maturated. Twenty two hours after fertilization, presumptive zygotes were co-culture with granulosa cells in CR2aa supplemented with 10% of fetal calf serum. Cleavage rate was assessed at 72 hours post-fertilization, and blastocyst production 192 hours post-fertilization. The

  2. Communicating systems with UML 2 modeling and analysis of network protocols

    CERN Document Server

    Barrera, David Garduno

    2013-01-01

    This book gives a practical approach to modeling and analyzing communication protocols using UML 2. Network protocols are always presented with a point of view focusing on partial mechanisms and starting models. This book aims at giving the basis needed for anybody to model and validate their own protocols. It follows a practical approach and gives many examples for the description and analysis of well known basic network mechanisms for protocols.The book firstly shows how to describe and validate the main protocol issues (such as synchronization problems, client-server interactions, layer

  3. A Self-Organizing Interaction and Synchronization Method between a Wearable Device and Mobile Robot.

    Science.gov (United States)

    Kim, Min Su; Lee, Jae Geun; Kang, Soon Ju

    2016-06-08

    In the near future, we can expect to see robots naturally following or going ahead of humans, similar to pet behavior. We call this type of robots "Pet-Bot". To implement this function in a robot, in this paper we introduce a self-organizing interaction and synchronization method between wearable devices and Pet-Bots. First, the Pet-Bot opportunistically identifies its owner without any human intervention, which means that the robot self-identifies the owner's approach on its own. Second, Pet-Bot's activity is synchronized with the owner's behavior. Lastly, the robot frequently encounters uncertain situations (e.g., when the robot goes ahead of the owner but meets a situation where it cannot make a decision, or the owner wants to stop the Pet-Bot synchronization mode to relax). In this case, we have adopted a gesture recognition function that uses a 3-D accelerometer in the wearable device. In order to achieve the interaction and synchronization in real-time, we use two wireless communication protocols: 125 kHz low-frequency (LF) and 2.4 GHz Bluetooth low energy (BLE). We conducted experiments using a prototype Pet-Bot and wearable devices to verify their motion recognition of and synchronization with humans in real-time. The results showed a guaranteed level of accuracy of at least 94%. A trajectory test was also performed to demonstrate the robot's control performance when following or leading a human in real-time.

  4. Selection of G1 Phase Yeast Cells for Synchronous Meiosis and Sporulation.

    Science.gov (United States)

    Stuart, David T

    2017-01-01

    Centrifugal elutriation is a procedure that allows the fractionation of cell populations based upon their size and shape. This allows cells in distinct cell cycle stages can be captured from an asynchronous population. The technique is particularly helpful when performing an experiment to monitor the progression of cells through the cell cycle or meiosis. Yeast sporulation like gametogenesis in other eukaryotes initiates from the G1 phase of the cell cycle. Conveniently, S. cerevisiae arrest in G1 phase when starved for nutrients and so withdrawal of nitrogen and glucose allows cells to abandon vegetative growth in G1 phase before initiating the sporulation program. This simple starvation protocol yields a partial synchronization that has been used extensively in studies of progression through meiosis and sporulation. By using centrifugal elutriation it is possible to isolate a homogeneous population of G1 phase cells and induce them to sporulate synchronously, which is beneficial for investigating progression through meiosis and sporulation. An additionally benefit of this protocol is that cell populations can be isolated based upon size and both large and small cell populations can be tested for progression through meiosis and sporulation. Here we present a protocol for purification of G1 phase diploid cells for examining synchronous progression through meiosis and sporulation.

  5. Ovarian matrix metalloproteinases are differentially regulated during the estrous cycle but not during short photoperiod induced regression in Siberian hamsters (Phodopus sungorus

    Directory of Open Access Journals (Sweden)

    Vrooman Lisa A

    2010-06-01

    Full Text Available Abstract Background Matrix metalloproteinases (MMPs are implicated as mediators for ovarian remodeling events, and are involved with ovarian recrudescence during seasonal breeding cycles in Siberian hamsters. However, involvement of these proteases as the photoinhibited ovary undergoes atrophy and regression had not been assessed. We hypothesized that 1 MMPs and their tissue inhibitors, the TIMPs would be present and differentially regulated during the normal estrous cycle in Siberian hamsters, and that 2 MMP/TIMP mRNA and protein levels would increase as inhibitory photoperiod induced ovarian degeneration. Methods MMP-2, -9, -14 and TIMP-1 and -2 mRNA and protein were examined in the stages of estrous (proestrus [P], estrus [E], diestrus I [DI], and diestrus II [DII] in Siberian hamsters, as well as after exposure to 3, 6, 9, and 12 weeks of inhibitory short photoperiod (SD. Results MMP-9 exhibited a 1.6-1.8 fold decrease in mRNA expression in DII (p Conclusions Although MMPs appear to be involved in the normal ovarian estrus cycle at the protein level in hamsters, those examined in the present study are unlikely to be key players in the slow atrophy of tissue as seen in Siberian hamster ovarian regression.

  6. Presence of a temperature gradient among genital tract portions and the thermal changes within these portions over the estrous cycle in beef cows.

    Science.gov (United States)

    El-Sheikh Ali, Hossam; Kitahara, Go; Tamura, Youji; Kobayashi, Ikuo; Hemmi, Koichiro; Torisu, Shidow; Sameshima, Hiroshi; Horii, Yoichiro; Zaabel, Samy; Kamimura, Shunichi

    2013-01-01

    The aim of the present study was to describe the temperature of the different portions of the female genital tract and their relation to rectal temperature and to investigate the effect of steroid hormones profiles on these variables over the estrous cycle in cattle. Four nonpregnant Japanese Black cows were investigated daily over two successive estrous cycles using a digital thermometer with a long probe and rounded-end sensor to record the temperature of the rectum (RT), vagina (VT), cervix (CT), uterine body (UBT) and uterine horns (UHT). Blood samples were collected immediately before temperature recording to assay peripheral levels of progesterone (P(4)) and estradiol-17β (E(2)). Moreover, transrectal ultrasonography was carried out after temperature recording to monitor the ovulatory follicle and track ovulation. During the experiment, the ambient temperature and relative humidity were recorded for further calculation of the temperature humidity index (THI). The temperature within the genital tracts in these cows progressively increased towards the uterine horns from the vagina. The VT, CT, UBT and UHTs were significantly higher in association with peripheral P(4) concentrations greater than 4 ng/ml (mid-luteal phase) when compared with lower peripheral P(4) concentrations. The VT was more significantly (Pfemale genital tract in bovine.

  7. V123 Beam Synchronous Encoder Module

    International Nuclear Information System (INIS)

    Kerner, T.; Conkling, C. R.; Oerter, B.

    1999-01-01

    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 fiberoptic 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

  8. Bursting synchronization in clustered neuronal networks

    International Nuclear Information System (INIS)

    Yu Hai-Tao; Wang Jiang; Deng Bin; Wei Xi-Le

    2013-01-01

    Neuronal networks in the brain exhibit the modular (clustered) property, i.e., they are composed of certain subnetworks with differential internal and external connectivity. We investigate bursting synchronization in a clustered neuronal network. A transition to mutual-phase synchronization takes place on the bursting time scale of coupled neurons, while on the spiking time scale, they behave asynchronously. This synchronization transition can be induced by the variations of inter- and intracoupling strengths, as well as the probability of random links between different subnetworks. Considering that some pathological conditions are related with the synchronization of bursting neurons in the brain, we analyze the control of bursting synchronization by using a time-periodic external signal in the clustered neuronal network. Simulation results show a frequency locking tongue in the driving parameter plane, where bursting synchronization is maintained, even in the presence of external driving. Hence, effective synchronization suppression can be realized with the driving parameters outside the frequency locking region. (interdisciplinary physics and related areas of science and technology)

  9. Oxytocin Removes Estrous Female vs. Male Preference of Virgin Male Rats: Mediation of the Supraoptic Nucleus Via Olfactory Bulbs

    Directory of Open Access Journals (Sweden)

    Xiao-Yu Liu

    2017-10-01

    Full Text Available Social functions of oxytocin (OT have been explored extensively; however, relationship between the effect of intranasally applied OT (nasal OT on the social preference (SP and intracerebral actions of endogenous OT remains unclear. To resolve this question, we first observed effects of nasal OT on the SP of virgin young adult male rats toward unfamiliar virgin estrous female (EF vs. virgin male rats. The results showed that the test male rats exhibited significantly more times and longer duration accessing the female than the male, which were acutely eliminated by nasal OT. Then, we examined the approaches mediating nasal OT effects on the activity of potential brain targets in Western blots and found that nasal OT activated the olfactory bulbs (OBs and the supraoptic nucleus (SON, but not the piriform cortex, amygdala and hippocampus as shown by significant changes in the expression of c-Fos and/or phosphorylated extracellular signal-regulated protein kinase (pERK 1/2. Moreover, microinjection of TTX into the OBs blocked nasal OT-evoked increases in pERK1/2 levels as well as the molecular association between ERK1/2 and OT-neurophysin in the SON. Electrolytic lesions of the lateral olfactory tract did not significantly change the basal levels of pERK 1/2 in the SON; however, upon nasal OT, pERK 1/2 levels in the SON reduced significantly. Lastly, microinjection of L-aminoadipic acid (gliotoxin into the SON to reduce OT levels reduced the duration of the test male’s accessing the EF and blocked the nasal OT-evoked increase in the duration of test male’s accessing the male while significantly increasing pERK1/2 levels in the amygdala. These findings reveal for the first time that nasal OT acutely eliminates virgin males’ SP to EFs via the OB-SON route and that OT neurons could mediate the social effects of nasal OT by suppressing social phobia generated in the amygdala.

  10. Expression of estrogen receptor α 36 (ESR36 in the hamster ovary throughout the estrous cycle: effects of gonadotropins.

    Directory of Open Access Journals (Sweden)

    Prabuddha Chakraborty

    Full Text Available Estradiol-17β (E plays an important role in ovarian follicular development. Evidence indicates that some of the effect of E is mediated by the transmembrane estrogen receptor. In this study, we examined the spatio-temporal expression of recently discovered ERα36 (ESR36, a splice variant of Esr1 and a receptor for non-genomic E signaling, in the hamster ovary during the estrous cycle and the role of gonadotropins and ovarian steroid hormones in ESR36 expression. ESR36 expression was high on estrus (D1:0900 h and declined precipitously by proestrus (D4:0900 h and remained low up to D4:1600 h. Immunofluorescence findings corroborated immunoblot findings and revealed that ESR36 was expressed only in the cell membrane of both follicular and non-follicular cells, except the oocytes. Ovarian ESR36 was capable of binding to the E-affinity matrix, and have different molecular weight than that of the ESR1 or GPER. Hypophysectomy (Hx resulted in a marked decline in ESR36 protein levels. FSH and LH, alone or combined, markedly upregulated ESR36 protein in Hx hamsters to the levels observed in D1 hamsters, but neither E nor P had any effect. Inhibition of the gonadotropin surge by phenobarbital treatment on D4:1100 h attenuated ESR36 expression in D1:0900 h ovaries, but the decline was restored by either FSH or LH replacement on D4 afternoon. This is the first report to show that ESR36, which is distinct from ESR1 or GPER is expressed in the plasma membrane of ovarian follicular and non-follicular cells, binds to E and its expression is regulated directly by the gonadotropins. In light of our previous findings, the results suggest that ovarian cells contain at least two distinct membrane estrogen receptors, such as GPER and ESR36, and strongly suggest for a non-genomic action of E regulating ovarian follicular functions.

  11. Implementation of IEEE-1588 timing and synchronization for ATCA control and data acquisition systems

    International Nuclear Information System (INIS)

    Correia, Miguel; Sousa, Jorge; Combo, Álvaro; Rodrigues, António P.; Carvalho, Bernardo B.; Batista, António J.N.; Gonçalves, Bruno; Correia, Carlos M.B.A.; Varandas, Carlos A.F.

    2012-01-01

    Highlights: ► IEEE-1588 over Ethernet protocol is implemented for the synchronization of all clock signals of an ATCA AMC carrier module. ► The ATCA hardware consists of an AMC quad-carrier main-board with PCI Express switching. ► IEEE-1588 is to be implemented on a Virtex-6 FPGA. ► Timing signals on the ATX-AMC4-PTP are managed and routed by a crosspoint-switch implemented on a Virtex-6 FPGA. ► Each clock signal source may be independently located (on each of the AMC cards, RTM or ATCA backplane). - Abstract: Control and data acquisition (C and DA) systems for Fusion experiments are required to provide accurate timing and synchronization (T and S) signals to all of its components. IPFN adopted PICMG's Advanced Telecommunications Computing Architecture (ATCA) industry standard to develop C and DA instrumentation. ATCA was chosen not only for its high throughput characteristics but also for its high availability (HA) features which become of greater importance in steady-state operation scenarios. However, the specified ATCA clock and synchronization interface may be too limited for the timing and synchronization needs in advanced Physics experiments. Upcoming specification extensions, developed by the “xTCA for Physics” workgroups, will contemplate, among others, a complementary timing specification, developed by the PICMG xTCA for Physics IO, Timing and Synchronization Technical Committee. The IEEE-1588 Precision Time Protocol (PTP) over Ethernet is one of the protocols, proposed by the Committee, aiming for precise synchronization of clocks in measurement and control systems, based on low jitter and slave-to-slave skew criteria. The paper presents an implementation of IEEE-1588 over Ethernet, in an ATCA hardware platform. The ATCA hardware consists of an Advanced Mezzanine Card (AMC) quad-carrier front board with PCI Express switching. IEEE-1588 is to be implemented on a Virtex-6 FPGA. Ethernet connectivity with the remote master clock is located on

  12. The cost of conservative synchronization in parallel discrete event simulations

    Science.gov (United States)

    Nicol, David M.

    1990-01-01

    The performance of a synchronous conservative parallel discrete-event simulation protocol is analyzed. The class of simulation models considered is oriented around a physical domain and possesses a limited ability to predict future behavior. A stochastic model is used to show that as the volume of simulation activity in the model increases relative to a fixed architecture, the complexity of the average per-event overhead due to synchronization, event list manipulation, lookahead calculations, and processor idle time approach the complexity of the average per-event overhead of a serial simulation. The method is therefore within a constant factor of optimal. The analysis demonstrates that on large problems--those for which parallel processing is ideally suited--there is often enough parallel workload so that processors are not usually idle. The viability of the method is also demonstrated empirically, showing how good performance is achieved on large problems using a thirty-two node Intel iPSC/2 distributed memory multiprocessor.

  13. Fuzzy stability and synchronization of hyperchaos systems

    International Nuclear Information System (INIS)

    Wang Junwei; Xiong Xiaohua; Zhao Meichun; Zhang Yanbin

    2008-01-01

    This paper studies stability and synchronization of hyperchaos systems via a fuzzy-model-based control design methodology. First, we utilize a Takagi-Sugeno fuzzy model to represent a hyperchaos system. Second, we design fuzzy-model-based controllers for stability and synchronization of the system, based on so-called 'parallel distributed compensation (PDC)'. Third, we reduce a question of stabilizing and synchronizing hyperchaos systems to linear matrix inequalities (LMI) so that convex programming techniques can solve these LMIs efficiently. Finally, the generalized Lorenz hyperchaos system is employed to illustrate the effectiveness of our designing controller

  14. Transmission delays in hardware clock synchronization

    Science.gov (United States)

    Shin, Kang G.; Ramanathan, P.

    1988-01-01

    Various methods, both with software and hardware, have been proposed to synchronize a set of physical clocks in a system. Software methods are very flexible and economical but suffer an excessive time overhead, whereas hardware methods require no time overhead but are unable to handle transmission delays in clock signals. The effects of nonzero transmission delays in synchronization have been studied extensively in the communication area in the absence of malicious or Byzantine faults. The authors show that it is easy to incorporate the ideas from the communication area into the existing hardware clock synchronization algorithms to take into account the presence of both malicious faults and nonzero transmission delays.

  15. Synchronization Of Parallel Discrete Event Simulations

    Science.gov (United States)

    Steinman, Jeffrey S.

    1992-01-01

    Adaptive, parallel, discrete-event-simulation-synchronization algorithm, Breathing Time Buckets, developed in Synchronous Parallel Environment for Emulation and Discrete Event Simulation (SPEEDES) operating system. Algorithm allows parallel simulations to process events optimistically in fluctuating time cycles that naturally adapt while simulation in progress. Combines best of optimistic and conservative synchronization strategies while avoiding major disadvantages. Algorithm processes events optimistically in time cycles adapting while simulation in progress. Well suited for modeling communication networks, for large-scale war games, for simulated flights of aircraft, for simulations of computer equipment, for mathematical modeling, for interactive engineering simulations, and for depictions of flows of information.

  16. The least channel capacity for chaos synchronization.

    Science.gov (United States)

    Wang, Mogei; Wang, Xingyuan; Liu, Zhenzhen; Zhang, Huaguang

    2011-03-01

    Recently researchers have found that a channel with capacity exceeding the Kolmogorov-Sinai entropy of the drive system (h(KS)) is theoretically necessary and sufficient to sustain the unidirectional synchronization to arbitrarily high precision. In this study, we use symbolic dynamics and the automaton reset sequence to distinguish the information that is required in identifying the current drive word and obtaining the synchronization. Then, we show that the least channel capacity that is sufficient to transmit the distinguished information and attain the synchronization of arbitrarily high precision is h(KS). Numerical simulations provide support for our conclusions.

  17. Adaptive H∞ Chaos Anti-synchronization

    International Nuclear Information System (INIS)

    Ahn, Choon Ki

    2010-01-01

    A new adaptive H ∞ anti-synchronization (AHAS) method is proposed for chaotic systems in the presence of unknown parameters and external disturbances. Based on the Lyapunov theory and linear matrix inequality formulation, the AHAS controller with adaptive laws of unknown parameters is derived to not only guarantee adaptive anti-synchronization but also reduce the effect of external disturbances to an H ∞ norm constraint. As an application of the proposed AHAS method, the H ∞ anti-synchronization problem for Genesio–Tesi chaotic systems is investigated. (general)

  18. Analysis of Synchronization for Coupled Hybrid Systems

    DEFF Research Database (Denmark)

    Li, Zheng; Wisniewski, Rafal

    2006-01-01

    In the control systems with coupled multi-subsystem, the subsystems might be synchronized (i.e. all the subsystems have the same operation states), which results in negative influence to the whole system. For example, in the supermarket refrigeration systems, the synchronized switch of each...... subsystem will cause low efficiency, inferior control performance and a high wear on the compressor. This paper takes the supermarket refrigeration systems as an example to analyze the synchronization and its coupling strengths of coupled hybrid systems, which may provide a base for further research...... of control strategies. This paper combines topology and section mapping theories together to show a new way of analyzing hybrid systems...

  19. Chaos synchronization of the energy resource system

    International Nuclear Information System (INIS)

    Li Xiuchun; Xu Wei; Li Ruihong

    2009-01-01

    This paper presents the chaos synchronization problem for new dynamical system (that is, energy resource demand-supply system), where the controller is designed using two different control methods. Firstly, based on stability criterion of linear system, chaotic synchronization is achieved with the help of the active theory, and accordingly, the simulation results are given for verifying the feasibility of the method. Secondly, based on Lyapunov stability theory, on the assumption that all the parameters of the system are unknown, adaptive control approach is proposed to make the states of two chaotic systems asymptotic synchronization. In the end, numerical simulations are used to show the effectiveness of the proposed control method.

  20. Synchronization of two coupled turbulent fires

    Science.gov (United States)

    Takagi, Kazushi; Gotoda, Hiroshi; Miyano, Takaya; Murayama, Shogo; Tokuda, Isao T.

    2018-04-01

    We numerically study the scale-free nature of a buoyancy-induced turbulent fire and synchronization of two coupled turbulent fires. A scale-free structure is detected in weighted networks between vortices, while its lifetime obeys a clear power law, indicating intermittent appearances, disappearances, and reappearances of the scale-free property. A significant decrease in the distance between the two fire sources gives rise to a synchronized state in the near field dominated by the unstable motion of large-scale of transverse vortex rings. The synchronized state vanishes in the far field forming well-developed turbulent plumes, regardless of the distance between the two fire sources.

  1. Synchronization System for Next Generation Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Zavriyev, Anton [MagiQ Technologies, Inc., Somerville, MA (United States)

    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.

  2. Usability of synchronization for cognitive modeling

    International Nuclear Information System (INIS)

    Diebner, Hans H.; Grond, Florian

    2005-01-01

    We discuss the synchronization features of a previously introduced adaptive system for dynamics recognition in more detail. We investigate the usability of synchronization for modeling and parameter estimations. It is pointed out inhowfar the adaptive system based on synchronization can become a powerful tool in modeling. The adaptive system can store modules of pre-adapted dynamics and is potentially capable of undergoing self-modification. We compare the stored modules with pre-knowledge that a modeler puts into his or her models. In this sense the adaptive system functions like an expert system

  3. Synchronous ethernet and IEEE 1588 in telecoms next generation synchronization networks

    CERN Document Server

    2013-01-01

    This book addresses the multiple technical aspects of the distribution of synchronization in new generation telecommunication networks, focusing in particular on synchronous Ethernet and IEEE1588 technologies. Many packet network engineers struggle with understanding the challenges that precise synchronization distribution can impose on networks. The usual “why”, “when” and particularly “how” can cause problems for many engineers. In parallel to this, some other markets have identical synchronization requirements, but with their own design requirements, generating further questions. This book attempts to respond to the different questions by providing background technical information. Invaluable information on state of-the-art packet network synchronization and timing architectures is provided, as well as an unbiased view on the synchronization technologies that have been internationally standardized over recent years, with the aim of providing the average reader (who is not skilled in the art) wi...

  4. Mac protocols for wireless sensor network (wsn): a comparative study

    International Nuclear Information System (INIS)

    Arshad, J.; Akram, Q.; Saleem, Y.

    2014-01-01

    Data communication between nodes is carried out under Medium Access Control (MAC) protocol which is defined at data link layer. The MAC protocols are responsible to communicate and coordinate between nodes according to the defined standards in WSN (Wireless Sensor Networks). The design of a MAC protocol should also address the issues of energy efficiency and transmission efficiency. There are number of MAC protocols that exist in the literature proposed for WSN. In this paper, nine MAC protocols which includes S-MAC, T-MAC, Wise-MAC, Mu-MAC, Z-MAC, A-MAC, D-MAC, B-MAC and B-MAC+ for WSN have been explored, studied and analyzed. These nine protocols are classified in contention based and hybrid (combination of contention and schedule based) MAC protocols. The goal of this comparative study is to provide a basis for MAC protocols and to highlight different mechanisms used with respect to parameters for the evaluation of energy and transmission efficiency in WSN. This study also aims to give reader a better understanding of the concepts, processes and flow of information used in these MAC protocols for WSN. A comparison with respect to energy reservation scheme, idle listening avoidance, latency, fairness, data synchronization, and throughput maximization has been presented. It was analyzed that contention based MAC protocols are less energy efficient as compared to hybrid MAC protocols. From the analysis of contention based MAC protocols in term of energy consumption, it was being observed that protocols based on preamble sampling consume lesser energy than protocols based on static or dynamic sleep schedule. (author)

  5. Kajian Literatur Sinkronisasi Waktu Dengan Network Time Protocol Untuk Pemantauan Aktivitas Jaringan Telekomunikasi

    Directory of Open Access Journals (Sweden)

    Ahmad Budi Setiawan

    2015-12-01

    Abstract Network providers are providing services or networks that enable the implementation of electronic transactions. Each network operator is required to align the time in electronic transactions. The purpose is to provide time alignment of the time standard and provide a time frame for all forms of electronic transactions with the principles of accuracy and traceability. Indonesian Time Alignment System uses the principle of traceability and accuracy principles. The protocols used in the alignment of the time server in Indonesia-based Network Time Protocol. This study discusses the implementation of time synchronization with a network time protocol as a form of telecommunications network security monitoring. The method used in this study is a descriptive narrative on the implementation of time synchronization. Results of this study are input to the policy in the security of electronic transactions through time synchronization

  6. Coexistence and switching of anticipating synchronization and lag synchronization in an optical system

    International Nuclear Information System (INIS)

    Wu, Liang; Zhu, Shiqun

    2003-01-01

    The chaotic synchronization between two bi-directionally coupled external cavity single-mode semiconductor lasers is investigated. Numerical simulation shows that anticipating synchronization and lag synchronization coexist and switch between each other in certain parameter regime. The anticipating time with different effects that were discussed quite differently in the previous theoretical analysis and experimental observation is determined by the involved parameters in the system

  7. A Lightweight Medium Access Protocol (LMAC) for Wireless Sensor Networks: Reducing Preamble Transmissions and Transceiver State Switches

    NARCIS (Netherlands)

    van Hoesel, L.F.W.; Havinga, Paul J.M.

    2004-01-01

    In this paper, we present an energy-efficient medium access protocol designed for wireless sensor networks. Although the protocol uses TDMA to give nodes in the WSN the opportunity to communicate collision-free, the network is self-organizing in terms of time slot assignment and synchronization. The

  8. On synchronization of three chaotic systems

    International Nuclear Information System (INIS)

    Yan Jianping; Li Changpin

    2005-01-01

    In this paper, a simple but efficient method is applied to the synchronization of three chaotic systems, i.e., the chaotic Lorenz, Chua, and Chen systems. Numerical simulations show this method works very well

  9. Robust adaptive synchronization of general dynamical networks ...

    Indian Academy of Sciences (India)

    Robust adaptive synchronization; dynamical network; multiple delays; multiple uncertainties. ... Networks such as neural networks, communication transmission networks, social rela- tionship networks etc. ..... a very good effect. Pramana – J.

  10. Multivalued synchronization by Poincaré coupling

    Science.gov (United States)

    Ontañón-García, L. J.; Campos-Cantón, E.; Femat, R.; Campos-Cantón, I.; Bonilla-Marín, M.

    2013-10-01

    This work presents multivalued chaotic synchronization via coupling based on the Poincaré plane. The coupling is carried out by an underdamped signal, triggered every crossing event of the trajectory of the master system through a previously defined Poincaré plane. A master-slave system is explored, and the synchronization between the systems is detected via the auxiliary system approach and the maximum conditional Lyapunov exponent. Due to the response to specific conditions two phenomena may be obtained: univalued and multivalued synchronization. Since the Lyapunov exponent is not enough to detect these two phenomena, the distance between the pieces of trajectories of the slave and auxiliary systems with different initial conditions is also used as a tool for the detection of multivalued synchronization. Computer simulations using the benchmark chaotic systems of Lorenz and Rössler are used to exemplify the approach proposed.

  11. New GOES satellite synchronized time code generation

    Science.gov (United States)

    Fossler, D. E.; Olson, R. K.

    1984-01-01

    The TRAK Systems' GOES Satellite Synchronized Time Code Generator is described. TRAK Systems has developed this timing instrument to supply improved accuracy over most existing GOES receiver clocks. A classical time code generator is integrated with a GOES receiver.

  12. Synchronization in complex networks with adaptive coupling

    International Nuclear Information System (INIS)

    Zhang Rong; Hu Manfeng; Xu Zhenyuan

    2007-01-01

    Generally it is very difficult to realized synchronization for some complex networks. In order to synchronize, the coupling coefficient of networks has to be very large, especially when the number of coupled nodes is larger. In this Letter, we consider the problem of synchronization in complex networks with adaptive coupling. A new concept about asymptotic stability is presented, then we proved by using the well-known LaSalle invariance principle, that the state of such a complex network can synchronize an arbitrary assigned state of an isolated node of the network as long as the feedback gain is positive. Unified system is simulated as the nodes of adaptive coupling complex networks with different topologies

  13. Synchronous correlation matrices and Connes’ embedding conjecture

    Energy Technology Data Exchange (ETDEWEB)

    Dykema, Kenneth J., E-mail: kdykema@math.tamu.edu [Department of Mathematics, Texas A& M University, College Station, Texas 77843-3368 (United States); Paulsen, Vern, E-mail: vern@math.uh.edu [Department of Mathematics, University of Houston, Houston, Texas 77204 (United States)

    2016-01-15

    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.

  14. Some Considerations on Seriality and Synchronicity

    OpenAIRE

    Elena Nechita

    2010-01-01

    This paper presents an overview of the results that have been obtained lately on seriality and synchronicity and their link, in the light of the new theories and within the frame of complexity science.

  15. Some Considerations on Seriality and Synchronicity

    Directory of Open Access Journals (Sweden)

    Elena Nechita

    2010-01-01

    Full Text Available This paper presents an overview of the results that have been obtained lately on seriality and synchronicity and their link, in the light of the new theories and within the frame of complexity science.

  16. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.

    1996-01-01

    The purpose of Phase 1 of the study is to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. The systems we consider are high data rate space communication systems. Also...... components. Node synchronization performed within a Viterbi decoder is discussed, and algorithms for frame synchronization are described and analyzed. We present a list of system configurations that we find potentially useful. Further, the high level architecture of units that contain frame synchronization...... and various other functions needed in a complete system is presented. Two such units are described, one for placement before the Viterbi decoder and another for placement after the decoder. The high level architectures of three possible implementations of Viterbi decoders are described: The first...

  17. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.

    1998-01-01

    The study has been divided into two phases. The purpose of Phase 1 of the study was to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. After selection of which specific...... potentially useful.Algorithms for frame synchronization are described and analyzed. Further, the high level architecture of units that contain frame synchronization and various other functions needed in a complete system is presented. Two such units are described, one for placement before the Viterbi decoder...... towards a realization in an FPGA.Node synchronization performed within a Viterbi decoder is discussed, and the high level architectures of three possible implementations of Viterbi decoders are described: The first implementation uses a number of commercially available decoders while the the two others...

  18. Dependence of synchronization frequency of Kuramoto oscillators ...

    Indian Academy of Sciences (India)

    2Department of Theoretical Physics, Physical Research Laboratory, ... on the sine of the phase difference between the oscillators and hence, ... we study the change in synchronization frequency as the symmetry is changed under the limit of.

  19. Dreams: a framework for distributed synchronous coordination

    NARCIS (Netherlands)

    Proença, J.; Clarke, D.; Vink, de E.P.; Arbab, F.

    2012-01-01

    Synchronous coordination systems, such as Reo, exchange data via indivisible actions, while distributed systems are typically asynchronous and assume that messages can be delayed or get lost. To combine these seemingly contradictory notions, we introduce the Dreams framework. Coordination patterns

  20. Pitch Synchronous Segmentation of Speech Signals

    Data.gov (United States)

    National Aeronautics and Space Administration — The Pitch Synchronous Segmentation (PSS) that accelerates speech without changing its fundamental frequency method could be applied and evaluated for use at NASA....

  1. SYNCHRONIZATION OF OVULATION IN BEEF HERDS ...

    African Journals Online (AJOL)

    IMPROVED CONCEPTION RATE AFTER AND INTERRUPTED COURSE ... with normal first insemination figures uncomplicated by synchronization and ... get her pregnant again so that she can consistently recalve ... Delayed ovulation may also contribute towards lower .... Effect of syttdtottizotbn on genad hcrd fatility.

  2. Synchronized flow in oversaturated city traffic.

    Science.gov (United States)

    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. E 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. Stochastic synchronization in finite size spiking networks

    Science.gov (United States)

    Doiron, Brent; Rinzel, John; Reyes, Alex

    2006-09-01

    We study a stochastic synchronization of spiking activity in feedforward networks of integrate-and-fire model neurons. A stochastic mean field analysis shows that synchronization occurs only when the network size is sufficiently small. This gives evidence that the dynamics, and hence processing, of finite size populations can be drastically different from that observed in the infinite size limit. Our results agree with experimentally observed synchrony in cortical networks, and further strengthen the link between synchrony and propagation in cortical systems.

  4. Stochastic Hydrodynamic Synchronization in Rotating Energy Landscapes

    OpenAIRE

    Koumakis, N.; Di Leonardo, R.

    2013-01-01

    Hydrodynamic synchronization provides a general mechanism for the spontaneous emergence of coherent beating states in independently driven mesoscopic oscillators. A complete physical picture of those phenomena is of definite importance to the understanding of biological cooperative motions of cilia and flagella. Moreover, it can potentially suggest novel routes to exploit synchronization in technological applications of soft matter. We demonstrate that driving colloidal particles in rotating ...

  5. Synchronous and Asynchronous ATM Multiplexor Properties Comparsion

    OpenAIRE

    Jan Zabka

    2006-01-01

    The article is aimed to ATM multiplexor computer model utilisation. Based on simulation runs we try to review aspects of use a synchronous and asynchronous ATM multiplexors. ATM multiplexor is the input queuing model with three inputs. Synchronous multiplexor works without an input priority. Multiplexor inputs are served periodically. Asynchronous multiplexor model supports several queuing and priority mechanisms. CLR and CTD are basic performance parameters. Input cell flows are genera...

  6. Projective synchronization based on suitable separation

    International Nuclear Information System (INIS)

    Li Guohui; Xiong Chuan; Sun Xiaonan

    2007-01-01

    A new approach for constructing a projective-synchronized chaotic slave system is proposed in this paper. This method is based on suitable separation by decomposing the system as the linear part and the nonlinear one. From matrix measure theory, some simple but efficient criteria are derived for projective synchronization of chaotic system. Numerical simulations for the Lorenz system show that this control method works very well

  7. Full state hybrid projective synchronization in hyperchaotic systems

    International Nuclear Information System (INIS)

    Chu Yandong; Chang Yingxiang; Zhang Jiangang; Li Xianfeng; An Xinlei

    2009-01-01

    In this letter, we investigate the full state hybrid projective synchronization (FSHPS) which includes complete synchronization, anti-synchronization and projective synchronization as its special items. Based on Lyapunov stability theory a controller can be designed for achieving the FSHPS of hyperchaotic systems. Numerical simulations are provided to verify the effectiveness of the proposed scheme.

  8. Complete synchronization of two Chen-Lee systems

    International Nuclear Information System (INIS)

    Sheu, L-J; Chen, J-H; Chen, H-K; Tam, L-M; Lao, S-K; Chen, W-C; Lin, K-T

    2008-01-01

    This study demonstrates that complete synchronization of two Chen-Lee chaotic systems can be easily achieved. The upper bound of the Chen-Lee chaotic system is estimated numerically. A controller is designed to synchronize two chaotic systems. Sufficient conditions for synchronization are obtained using Lyapunov's direct method. Two numerical examples are presented to verify the proposed synchronization approach

  9. Nonlinear observer based phase synchronization of chaotic systems

    International Nuclear Information System (INIS)

    Meng Juan; Wang Xingyuan

    2007-01-01

    This Letter analyzes the phase synchronization problem of autonomous chaotic systems. Based on the nonlinear state observer algorithm and the pole placement technique, a phase synchronization scheme is designed. The phase synchronization of a new chaotic system is achieved by using this observer controller. Numerical simulations further demonstrate the effectiveness of the proposed phase synchronization scheme

  10. Frame Synchronization Without Attached Sync Markers

    Science.gov (United States)

    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).

  11. Synchronization of mobile chaotic oscillator networks

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, Naoya, E-mail: fujiwara@csis.u-tokyo.ac.jp [Center for Spatial Information Science, The University of Tokyo, 277-8568 Chiba (Japan); Kurths, Jürgen [Potsdam Institute for Climate Impact Research (PIK), 14473 Potsdam, Germany and Institute for Complex Systems and Mathematical Biology, University of Aberdeen, Aberdeen (United Kingdom); Díaz-Guilera, Albert [Departament de Física de la Matèria Condensada, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain and Universitat de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, Barcelona (Spain)

    2016-09-15

    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.

  12. Synchronization of mobile chaotic oscillator networks

    International Nuclear Information System (INIS)

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

    2016-01-01

    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.

  13. Synchronization of mobile chaotic oscillator networks.

    Science.gov (United States)

    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.

  14. Explosive synchronization transitions in complex neural networks

    Science.gov (United States)

    Chen, Hanshuang; He, Gang; Huang, Feng; Shen, Chuansheng; Hou, Zhonghuai

    2013-09-01

    It has been recently reported that explosive synchronization transitions can take place in networks of phase oscillators [Gómez-Gardeñes et al. Phys. Rev. Lett. 106, 128701 (2011)] and chaotic oscillators [Leyva et al. Phys. Rev. Lett. 108, 168702 (2012)]. Here, we investigate the effect of a microscopic correlation between the dynamics and the interacting topology of coupled FitzHugh-Nagumo oscillators on phase synchronization transition in Barabási-Albert (BA) scale-free networks and Erdös-Rényi (ER) random networks. We show that, if natural frequencies of the oscillations are positively correlated with node degrees and the width of the frequency distribution is larger than a threshold value, a strong hysteresis loop arises in the synchronization diagram of BA networks, indicating the evidence of an explosive transition towards synchronization of relaxation oscillators system. In contrast to the results in BA networks, in more homogeneous ER networks, the synchronization transition is always of continuous type regardless of the width of the frequency distribution. Moreover, we consider the effect of degree-mixing patterns on the nature of the synchronization transition, and find that the degree assortativity is unfavorable for the occurrence of such an explosive transition.

  15. Fault-tolerant clock synchronization in distributed systems

    Science.gov (United States)

    Ramanathan, Parameswaran; Shin, Kang G.; Butler, Ricky W.

    1990-01-01

    Existing fault-tolerant clock synchronization algorithms are compared and contrasted. These include the following: software synchronization algorithms, such as convergence-averaging, convergence-nonaveraging, and consistency algorithms, as well as probabilistic synchronization; hardware synchronization algorithms; and hybrid synchronization. The worst-case clock skews guaranteed by representative algorithms are compared, along with other important aspects such as time, message, and cost overhead imposed by the algorithms. More recent developments such as hardware-assisted software synchronization and algorithms for synchronizing large, partially connected distributed systems are especially emphasized.

  16. Quantum synchronization in an optomechanical system based on Lyapunov control.

    Science.gov (United States)

    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)PRLTAO0031-900710.1103/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. Expression of glutamic acid decarboxylase (GAD) mRNA in the preoptic region of the brain during the estrous cycle of the ewe

    International Nuclear Information System (INIS)

    Pompolo, S.; Clarke, I.J.; Scott, C.J.

    2001-01-01

    Full text: Gamma-aminobutyric acid (GABA) is thought to regulate gonadotropin releasing hormone (GnRH) neurones located in the preoptic area (POA). GABA neurons in this region,express estrogen receptors, and synapse with GnRH cells. Reduced levels of GABA are thought to be permissive of the preovulatory LH surge. We aimed to determine whether the function of GABA changes across the ovine estrous cycle. GAD is an enzyme that synthesises GABA. We measured mRNA levels for the GAD-65 transcript in the diagonal band of Broca (dbB), POA and bed nucleus of stria terminalis (BnST) of ewes (4/group) that were killed (overdose of Pentobarbital) during the luteal (L), follicular (F) or estrous (E) phase of the estrous cycle. Brains were perfused and processed for in situ hybridisation.Sections (20 μm) were hybridised with an 35 S-labelled GAD-65 probe and the number of silver grains/cell was counted. Grains/cell were similar across the cycle in dbB and the ventral BnST. In the dorsal and lateral BnST, GAD expression was greater (P<0.05) in the L (65 ± 3;SEM) than in F (56 ± 30), with a return to luteal phase levels at estrus (70 ± 3). Expression in the POA was lower (P<0.05) during estrus (54 ± 3) than during the luteal phase (70 ± 4). These data show that expression of GAD-65 is lower in some regions of BnST at the time of the cycle (follicular) when estrogen initiates events that lead to the preovulatory LH surge. Expression in the POA is lower at estrus (during the GnRH/LH surge) than during the luteal phase:this could be permissive of the surge. Higher GAD-65 expression in the luteal phase could be due to high progesterone levels at this time of the cycle. Copyright (2001) Australian Neuroscience Society

  18. Semi-quantitative ultrastructural analysis of the localization and neuropeptide content of gonadotropin releasing hormone nerve terminals in the median eminence throughout the estrous cycle of the rat.

    Science.gov (United States)

    Prevot, V; Dutoit, S; Croix, D; Tramu, G; Beauvillain, J C

    1998-05-01

    The ultrastructural appearance of gonadotropin releasing hormone-immunoreactive elements was studied in the external zone of the median eminence of adult female Wistar rats. On the one hand, the purpose of the study was to determine the distribution of gonadotropin releasing hormone terminals towards the parenchymatous basal lamina at the level of hypothalamo-hypophyseal portal vessels, throughout the estrous cycle. On the other hand, we have semi-quantified the gonadotropin releasing hormone content in nerve terminals or preterminals during this physiological condition. A morphometric study was coupled to a colloidal 15 mn gold postembedding immunocytochemistry procedure. Animals were killed at 09.00 on diestrus II, 0.900, 10.00, 13.00, 17.00 and 18.00 on proestrus and 09.00 on estrus (n = 4-8 rats/group). A preliminary light microscopic study was carried out to identify an antero-posterior part of median eminence strongly immunostained by anti-gonadotropin releasing hormone antibodies but which was, in addition, easily spotted. This last condition was necessary to make a good comparison between each animal. Contacts between gonadotropin releasing hormone nerve terminals and the basal lamina were observed only the day of proestrus. Such contacts, however, were rare and in the great majority of cases, gonadotropin releasing hormone terminals are separated from basal lamina by tanycytic end feet. The morphometric analysis showed no significant variation in average distance between gonadotropin releasing hormone terminals and capillaries throughout the estrous cycle. Consequently, it did not appear that a large neuroglial plasticity exists during the estrous cycle. However, the observation of contacts only on proestrus together with some ultrastructural images evoke the possibility of a slight plasticity. The semi-quantitative results show that the content of gonadotropin releasing hormone in the nerve endings presented two peaks on proestrus: one at 09.00 (23 +/- 5

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

    Directory of Open Access Journals (Sweden)

    Samuel Gebremedhn

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

  20. Clock Synchronization in Wireless Sensor Networks: A New Model and Analysis Approach Based on Networked Control Perspective

    Directory of Open Access Journals (Sweden)

    Wang Ting

    2014-01-01

    Full Text Available Motivated by the importance of the clock synchronization in wireless sensor networks (WSNs, this paper proposes a new research approach and model approach, which quantitatively analyzes clock synchronization from the perspective of modern control theory. Two kinds of control strategies are used as examples to analyze the effect of the control strategy on clock synchronization from different perspectives, namely, the single-step optimal control and the LQG global optimal control. The proposed method establishes a state space model for clock relationship, thus making dimension extension and parameter identification easier, and is robust to changes under the condition of node failures and new nodes. And through the design of different control strategies and performance index functions, the method can satisfy various requirements of the synchronization precision, convergence speed, energy consumption and the computational complexity, and so on. Finally, the simulations show that the synchronization accuracy of the proposed method is higher than that of the existing protocol, and the former convergence speed of the synchronization error is faster.

  1. Chaos synchronization in autonomous chaotic system via hybrid feedback control

    International Nuclear Information System (INIS)

    Yang Lixin; Chu Yandong; Zhang Jiangang; Li Xianfeng; Chang Yingxiang

    2009-01-01

    This paper presents the synchronization of chaos by designing united controller. First, this method is implemented in synchronization of a simple system, then we realize the synchronization of Lue hyperchaotic system, we also take tracking control to realize the synchronization of Lue hyperchaotic system. Comparing with results, we can find that hybrid feedback control approach is more effective than tracking control for hyperchaotic system. Numerical simulations show the united synchronization method works well.

  2. Synchronization of Coupled Neurons Controlled by a Pacemaker

    International Nuclear Information System (INIS)

    Li Mei-Sheng; Zhang Hong-Hui; Zhao Yong; Shi Xia

    2011-01-01

    We investigate synchronization of Hindmarsh—Rose neurons with gap junctions under the control of a pacemaker. In a ring Hindmarsh—Rose neuronal network, the coupled neurons with the pacemaker can occur in synchronization more easily than those without the pacemaker. Furthermore, the pacemaker can induce phase synchronization or nearly-complete synchronization of nonidentical neurons. This synchronization can occur more easily when time delay is considered. Theses results can be helpful to understand the activities of the real neuronal system. (general)

  3. Chaos synchronizations of chaotic systems via active nonlinear control

    International Nuclear Information System (INIS)

    Huang, J; Xiao, T J

    2008-01-01

    This paper not only investigates the chaos synchronization between two LCC chaotic systems, but also discusses the chaos synchronization between LCC system and Genesio system. Some novel active nonlinear controllers are designed to achieve synchronizations between drive and response systems effectively. Moreover, the sufficient conditions of synchronizations are derived by using Lyapunov stability theorem. Numerical simulations are presented to verify the theoretical analysis, which shows that the synchronization schemes are global effective

  4. Guide to Synchronization of Video Systems to IRIG Timing

    Science.gov (United States)

    1992-07-01

    and industry. 1-2 CHAPTER 2 SYNCHRONISATION Before delving into the details of synchronization , a review is needed of the reasons for synchronizing ... Synchronization of Video Systems to IRIG Timing Optical Systems Group Range Commanders Council White Sands Missile Range, NM 88002-5110 RCC Document 456-92 Range...This document addresses a broad field of video synchronization to IRIG timing with emphasis on color synchronization . This document deals with

  5. Fast Self-Synchronization between LowVoltage Microgrid and Inverter using Virtual Synchronous Converter

    Directory of Open Access Journals (Sweden)

    Md Ruhul Amin

    2017-12-01

    Full Text Available In this paper, a fast self-synchronization known as virtual synchronous converter (VSCon between single-phase microgrid and inverter in low-voltage microgrid, has been developed in Matlab/Simulink. The idea is to any phase locked loop (PLL circuit for inverter-microgrid synchronization in order to improve the synchronization time. As known, it is difficult and lengthy process to tune the PLL gain parameters to reach suitable performance for synchronizing among the voltage, phase-angle and frequency between them. Due to this problem, a fast self synchronization technique is needed in order to minimize the time losses at the microgrid connection. Therefore, the VSCon has been developed which is based on the synchronous generator mathematical model but in virtual environment representation. It has been applied in the inverter control for generating switching pattern to the inverter switches in order to respond to the grid voltage for improve the synchronization. For a prove of concept, several simulation tests in MATLAB models have been conducted, in order to see the effectiveness of this VSCon. First test has been conducted, when a 240V, 50Hz frequency grid source is used for observing the self-synchronization the system with the power flows output. Furthermore, the next test is conducted when the grid frequency is changed from the rated frequency at 50Hz to 51Hz and the result shows the VSCon in inverter control takes nearly 40ms to synchronize to this new frequency value. The test on grid phase-angle delay also been tested when ac grid voltage has 150 phase delay. As from all the results, the improved inverter control with VSCon structure is able to have fast and self-synchronized between the invertergrid connection before the power from the inverter can be transferred.

  6. USE OF SODIUM CLOPROSTENOL AND OESTRADIOL BENZOATE IN BEEF CATTLE FEMALES INSEMINATED IN FIXED-TIME WITH OR WITHOUT ESTROUS RETECTION UTILIZAÇÃO DE CLOPROSTENOL SÓDICO E BENZOATO DE ESTRADIOL EM VACAS DE CORTE INSEMINADAS EM TEMPO-FIXO OU COM OBSERVAÇÃO DE CIO

    Directory of Open Access Journals (Sweden)

    Nelson José Laurino Dionello

    2007-12-01

    Full Text Available

    The aim of this study was to evaluate the use of a prostaglandin F2α analogue (PGF2α and oestradiol benzo-ate (ODB in estrus synchronization programs. A hundred and eighty five non-lactating females divided in 4 groups were used. G1 (44 and G2 (46 received two applications of PGF2α (D0 and D11 and G3 (26 and G4 (37 received one application after 5 days of estrous detection. G1 and G3 also received a 1 mg ODB application 48 hours after the PGF2α. The pregnancy rate at AI was 42,2% for G1, 47,8% for G2, 32,1% for G3 e 57,6% for G4 (p>0,05 and of 38,4% and 51,4% for animals submitted to FTAI and estrous detection, respectively (p>0,05. This results show that pregnancy rates of females fixed time inseminated didn’t differ of that inseminated after estrus detection.

    Key-words: Beef cattle, estrus synchronization, fixed time artificial insemination, prostaglandin.

    O objetivo deste estudo foi avaliar o emprego de um análogo da prostaglandina F2α (PGF2α em associação ao benzoato de estradiol (BE em programas de sincronização de cios. Utilizaram-se 185 fêmeas não-lactantes divididas em quatro grupos. O G1 (44 e o G2 (46 receberam duas aplicações de PGF2α (D0 e D11 e os animais do G3 (26 e G4 (37 uma aplicação de PGF2α, após cinco dias de detecção de cio. O G1 e o G3 receberam 1mg de BE 48 horas após a PGF2α. A taxa de prenhez na IA foi de 42,2% no G1, 47,8% no G2, 32,1% no G3 e 57,6% no G4 (p>0,05 e de 38,4% e 51,4% para animais submetidos à IATF e à detecção de cio, respectivamente (p>0,05. Notou-se que a taxa de prenhez nas fêmeas inseminadas em tempo-fixo não diferiu daquelas que foram inseminadas após a detecção de cio.

    Palavras-chaves: Bovinos de corte, inseminação artificial em tempo fixo, prostaglandina, sincronização de cios.

  7. LHRH incorporation in normal and denervated pineal gland, and in pineal gland of rats with constant estrous-anovulatory syndrome: a preliminary study

    International Nuclear Information System (INIS)

    Trentini, G.P.; DeGaetani, C.F.; DiGregorio, C.; Botticelli, C.S.

    1980-01-01

    Pineal gland and superior sympathetic cervical ganglia accumulated intravenously injected 3 H-LHRH in an amount significantly higher than anterior and posterior hypothalamus, cerebral cortex and pituitary gland, the latter a specific target for LHRH. The prior administration of unlabelled LHRH significantly decreased the 3 H-LHRH incorporation only in pineal and pituitary gland. Autoradiography showed that the radiolabel was localized at the level of the pinealocytes, with a seemingly, prevalent distribution of grains on the cellular contours. Pineal incorporation of LHRH was not significantly modified by either acute or chronic bilateral cervical ganglionectomy, although acute ganglioectomy resulted in a slight decrease in LHRH accumulation by pineal gland. Constant estrous anovulatory syndromes induced by either frontal hypothalamic deafferentation, or continuous illumination or neonatal androgenization did not appear to modify the LHRH incorporation in either pineal gland or cervical ganglia. Basing on these results, the pineal gland is supposed to be a target organ for LHRH. (author)

  8. Breaking projective chaos synchronization secure communication using filtering and generalized synchronization

    International Nuclear Information System (INIS)

    Alvarez, G.; Li Shujun; Montoya, F.; Pastor, G.; Romera, M.

    2005-01-01

    This paper describes the security weaknesses of a recently proposed secure communication method based on chaotic masking using projective synchronization of two chaotic systems. We show that the system is insecure and how to break it in two different ways, by high-pass filtering and by generalized synchronization

  9. Pinning-controlled synchronization of complex networks with bounded or unbounded synchronized regions

    International Nuclear Information System (INIS)

    Yan-Li, Zou; Guan-Rong, Chen

    2009-01-01

    This paper studies pinning-controlled synchronization of complex networks with bounded or unbounded synchronized regions. To study a state-feedback pinning-controlled network with N nodes, it first converts the controlled network to an extended network of N+1 nodes without controls. It is shown that the controlled synchronizability of the given network is determined by the real part of the smallest nonzero eigenvalue of the coupling matrix of its extended network when the synchronized region is unbounded; but it is determined by the ratio of the real parts of the largest and the smallest nonzero eigenvalues of the coupling matrix when the synchronized region is bounded. Both theoretical analysis and numerical simulation show that the portion of controlled nodes has no critical values when the synchronized region is unbounded, but it has a critical value when the synchronized region is bounded. In the former case, therefore, it is possible to control the network to achieve synchronization by pinning only one node. In the latter case, the network can achieve controlled synchronization only when the portion of controlled nodes is larger than the critical value. (general)

  10. Vertical Protocol Composition

    DEFF Research Database (Denmark)

    Groß, Thomas; Mödersheim, Sebastian Alexander

    2011-01-01

    The security of key exchange and secure channel protocols, such as TLS, has been studied intensively. However, only few works have considered what happens when the established keys are actually used—to run some protocol securely over the established “channel”. We call this a vertical protocol.......e., that the combination cannot introduce attacks that the individual protocols in isolation do not have. In this work, we prove a composability result in the symbolic model that allows for arbitrary vertical composition (including self-composition). It holds for protocols from any suite of channel and application...

  11. Sex and estrous cycle-dependent changes in neurosteroid and benzodiazepine effects on food consumption and plus-maze learning behaviors in rats.

    Science.gov (United States)

    Reddy, D S; Kulkarni, S K

    1999-01-01

    Experiments were designed to investigate the influence of estrous cycle and gender of the rat on the effects of a gamma-aminobutyric acid type A (GABA(A)) receptor active neurosteroid, 3alpha-hydroxy-5alpha-pregnan-20-one (allopregnanolone), the benzodiazepine, triazolam, and a GABA(A) receptor antagonistic neurosteroid, delta5-androsten-3beta-ol-17-one sulfate (dehydroepiandrosterone sulfate), on food intake and elevated plus-maze learning behaviors. Allopregnanolone (0.25 mg/kg, s.c.) and triazolam (0.25 mg/kg, i.p.) produced a hyperphagic effect, while dehydroepiandrosterone sulfate (5 mg/kg, s.c.) elicited an anorectic effect. However, allopregnanolone was more potent in diestrous females, whereas triazolam exhibited significantly higher hyperphagic potency in estrus females. The extent of anorexia following dehydroepiandrosterone sulfate was alike in male and female rats. The triazolam- and allopregnanolone-induced hyperphagic effect was blocked by bicuculline (1 mg/kg, i.p.), a selective GABA(A) receptor antagonist. In contrast to triazolam, the hyperphagic effect of allopregnanolone was insensitive to flumazenil (5 mg/kg, i.p.), a benzodiazepine antagonist. Vehicle-treated diestrous rats displayed moderately higher latencies in the elevated plus-maze learning task than estrus or proestrus females. Although allopregnanolone and triazolam elicited equipotent learning deficits in plus-maze learning in male and female rats, the magnitude of impairment-induced by triazolam was significantly higher in diestrous females than proestrus females. Dehydroepiandrosterone sulfate enhanced memory performance only in male rats. Although the use of the elevated plus-maze as a learning paradigm with benzodiazepines and neurosteroids may be sensitive to changes in anxiety, the differential data suggest that neurosteroid-induced effects are at least partly specific to learning behavior. These results confirm the role of estrous cycle and sex of rats in modifying the potency of

  12. Influence of continuous illumination on estrous cycle of rats: time course of changes in levels of gonadotropins and ovarian steroids until occurrence of persistent estrus.

    Science.gov (United States)

    Takeo, Y

    1984-08-01

    Plasma concentrations of LH, FSH, 17 beta-estradiol, estrone and progesterone were determined chronologically by radioimmunoassays in two groups of adult female rats exposed to continuous illumination (LL). Group 1 rats showing vaginal estrous cycles were sacrificed at 3- to 6-hour intervals during late proestrus through early estrus of the first 5 cycles after exposure to LL. Group 2 animals which displayed persistent vaginal estrus in an early period of exposure to LL were killed on the 2nd, 3rd, 4th, 5th and 7th days of vaginal estrus. In Group 1 rats, surges of the hormones, except estrone, took place in all the 5 cycles. The occurrence of peak hormone levels in each cycle was invariably delayed after transfer of animals to LL. According to regression analyses, the lengths of secretion cycles of LH, FSH, 17 beta-estradiol and progesterone in rats under LL were 100.89, 100.46, 101.14 and 101.06 h, respectively. Elevation of 17 beta-estradiol levels was observed prior to the LH surge, and peaks of progesterone and FSH occurred following it. However, the secretion patterns of these hormones appear to be disrupted with length of exposure to LL. In group 2 rats, the mean concentration of LH during persistent estrus was approximately similar to that on the morning of the days of proestrus of the 4-day cycles of rats placed under an alternating 12-hour light-dark regimen (LD), whereas the mean FSH concentration was continuously low. While the concentrations of 17 beta-estradiol and estrone in persistent-estrous rats were elevated, progesterone levels remained low.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Influence of body condition and bovine somatotropin on estrous behavior, reproductive performance, and concentrations of serum somatotropin and plasma fatty acids in postpartum Brahman-influenced cows.

    Science.gov (United States)

    Flores, R; Looper, M L; Rorie, R W; Lamb, M A; Reiter, S T; Hallford, D M; Kreider, D L; Rosenkrans, C F

    2007-05-01

    Ninety-nine multiparous Brahman-influenced (1/4 to 3/8 Brahman) cows were managed to achieve low (BCS = 4.3 +/- 0.1; n = 50) or moderate (BCS = 6.1 +/- 0.1; n = 49) body condition (BC) to determine the influence of bovine somatotropin (bST) on estrous characteristics, reproductive performance, and concentrations of serum GH and plasma NEFA. Beginning 32 d postpartum, cows within each BC were assigned randomly to treatment with or without bST. Non-bST-treated cows received no treatment, and treated cows were administered bST (Posilac, 500 mg s.c.) on d -35, -21, and -7 before initiation of the breeding season. On d -7, all cows received an intravaginal, controlled internal drug-releasing (CIDR) device. On d 0 (initiation of the 70-d breeding season), the CIDR were removed and cows received prostaglandin F2alpha (PGF2alpha). Blood samples were collected from the median caudal vein of the cows at each bST treatment and at d -28 and 0. Estrous behavior was monitored by radiotelemetry during the first 30 d of the breeding season. Growth hormone was increased (P conception rate tended (P = 0.07) to be greater for bST-low BC cows than non-bST-treated cows in low or moderate BC. On d 0, NEFA were greater (P conception rate during the first 30 d of breeding and pregnancy rates during the first 3 d of breeding in postpartum Brahman-influenced cows.

  14. Influence of sex and estrous cycle on synaptic responses of the medial vestibular nuclei in rats: role of circulating 17β-estradiol.

    Science.gov (United States)

    Grassi, Silvarosa; Frondaroli, Adele; Scarduzio, Mariangela; Dieni, Cristina V; Brecchia, Gabriele; Boiti, Cristiano; Pettorossi, Vito E

    2012-02-10

    We investigated the possible influence of sex and estrous cycle on the synaptic responses of neurons in the medial vestibular nucleus (MVN) and their long-term modifications. In brain stem slices of male and female rats during proestrus (PE) and diestrus (DE), we evaluated the field potential evoked in the MVN by vestibular afferent stimulation. Here we find that in PE females the field potential had a lower threshold and higher amplitude than in DE females and in males and also that the stimulus-response curve was shifted to the left. Such difference is related to the level and cyclic fluctuation of circulating 17β-estradiol (E(2)). This is supported by the exogenous administration of E(2) in DE females and males, with low levels of circulating E(2) that enhanced the field potential amplitude to values close to those of PE females. Sex and estrous cycle also influence the MVN synaptic plasticity. This has been shown by investigating the effect of testosterone (T) on the induction of long-term effects, since T is the precursor for the neural synthesis of E(2) (estrogenic pathway), which is involved in the induction of fast long-term potentiation (LTP), or of 5α-dihydrotestosterone (DHT, androgenic pathway) which mediates slow LTP and long-term depression (LTD). We found that T mostly induced LTD in PE females and no effect in DE females, while it only provoked fast LTP in males. We suggest that high level of circulating E(2) may interfere with the conversion of T, by inhibiting the neural estrogenic pathway and facilitating the androgenic one. On the whole these results demonstrate an influence of circulating E(2) on vestibular synaptic transmission and plasticity that in some cases may contribute to the sex and menstrual cycle dependence of symptoms in human vestibular pathology. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Collagen and Glycosaminoglycan Profiles in the Canine Cervix during Different Stages of the Estrous Cycle and in Open- and Closed-Cervix Pyometra

    Science.gov (United States)

    LINHARATTANARUKSA, Pichanun; SRISUWATANASAGUL, Sayamon; PONGLOWHAPAN, Suppawiwat; KHALID, Muhammad; CHATDARONG, Kaywalee

    2013-01-01

    ABSTRACT The extracellular matrix of the cervix that comprises collagen, elastin, proteoglycans and glycosaminoglycans (GAGs) is thought to have an essential role in cervical relaxation. This study investigated the proportion of collagen and smooth muscle as well as the GAGs in cervices obtained from healthy bitches at different stages of the estrous cycle and bitches with open- and closed-cervix pyometra. Cervices were collected after ovariohysterectomy. The proportion of collagen to smooth muscle was determined using Masson’s trichrome staining. Alcian blue staining was used to evaluate the relative distribution of cervical GAGs. The proportion of cervical collagen relative to smooth muscle was higher at estrus compared to anestrus (P≤0.05). It was also higher (P≤0.05) in bitches with open- compared to those with closed-cervix pyometra. Overall, hyaluronan (HA) was the predominant GAG in the canine cervix. In the luminal epithelium, the staining intensity for HA was stronger in estrus than in anestrus (P≤0.05), but not in diestrus (P>0.05). On the contrary, the intensity for the combined keratan sulfate (KS) and heparan sulfate (HS) was stronger in anestrus than in estrus and diestrus (P≤0.05). In bitches with pyometra, the staining intensity of the stroma for KS and HS was weaker in open- compared to closed-cervix pyometra (P≤0.05). Collectively, the different profiles of collagen and GAG suggest that the metabolism of both collagen and GAGs in the canine cervix is associated with hormonal statuses during the estrous cycle and cervical patency of bitches with pathological uterine conditions, such as pyometra. PMID:24152876

  16. Symbol synchronization and sampling frequency synchronization techniques in real-time DDO-OFDM systems

    Science.gov (United States)

    Chen, Ming; He, Jing; Cao, Zizheng; Tang, Jin; Chen, Lin; Wu, Xian

    2014-09-01

    In this paper, we propose and experimentally demonstrate a symbol synchronization and sampling frequency synchronization techniques in real-time direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) system, over 100-km standard single mode fiber (SSMF) using a cost-effective directly modulated distributed feedback (DFB) laser. The experiment results show that the proposed symbol synchronization based on training sequence (TS) has a low complexity and high accuracy even at a sampling frequency offset (SFO) of 5000-ppm. Meanwhile, the proposed pilot-assisted sampling frequency synchronization between digital-to-analog converter (DAC) and analog-to-digital converter (ADC) is capable of estimating SFOs with an accuracy of technique can also compensate SFO effects within a small residual SFO caused by deviation of SFO estimation and low-precision or unstable clock source. The two synchronization techniques are suitable for high-speed DDO-OFDM transmission systems.

  17. Leader-follower consensus and synchronization in numerosity-constrained networks with dynamic leadership.

    Science.gov (United States)

    Roy, Subhradeep; Abaid, Nicole

    2016-11-01

    In this work, we study leader-follower consensus and synchronization protocols over a stochastically switching network. The agents representing the followers can communicate with any other agent, whereas the agents serving as leaders are restricted to interact only with the other leaders. The model incorporates the phenomenon of numerosity, which limits the perceptual capacity of the agents while allowing for shuffling with whom each individual interacts at each time step. We derive closed form expressions for necessary and sufficient conditions for consensus, the rate of convergence to consensus, and conditions for stochastic synchronization in terms of the asymptotic convergence factor. We provide simulation results to validate the theoretical findings and to illustrate the dependence of this factor on system parameters. The closed form results enable us to study the factors affecting the feasibility of consensus. We show that agents' traits can be chosen for an engineered system to maximize the convergence speed and that protocol speed is enhanced as the proportion of the leaders increases in certain cases. These results may find application in the design and control of an engineered leader-follower system, where consensus or synchronization at the fastest possible rate is desired.

  18. Leader-follower consensus and synchronization in numerosity-constrained networks with dynamic leadership

    Science.gov (United States)

    Roy, Subhradeep; Abaid, Nicole

    2016-11-01

    In this work, we study leader-follower consensus and synchronization protocols over a stochastically switching network. The agents representing the followers can communicate with any other agent, whereas the agents serving as leaders are restricted to interact only with the other leaders. The model incorporates the phenomenon of numerosity, which limits the perceptual capacity of the agents while allowing for shuffling with whom each individual interacts at each time step. We derive closed form expressions for necessary and sufficient conditions for consensus, the rate of convergence to consensus, and conditions for stochastic synchronization in terms of the asymptotic convergence factor. We provide simulation results to validate the theoretical findings and to illustrate the dependence of this factor on system parameters. The closed form results enable us to study the factors affecting the feasibility of consensus. We show that agents' traits can be chosen for an engineered system to maximize the convergence speed and that protocol speed is enhanced as the proportion of the leaders increases in certain cases. These results may find application in the design and control of an engineered leader-follower system, where consensus or synchronization at the fastest possible rate is desired.

  19. Versatile synchronized real-time MEG hardware controller for large-scale fast data acquisition

    Science.gov (United States)

    Sun, Limin; Han, Menglai; Pratt, Kevin; Paulson, Douglas; Dinh, Christoph; Esch, Lorenz; Okada, Yoshio; Hämäläinen, Matti

    2017-05-01

    Versatile controllers for accurate, fast, and real-time synchronized acquisition of large-scale data are useful in many areas of science, engineering, and technology. Here, we describe the development of a controller software based on a technique called queued state machine for controlling the data acquisition (DAQ) hardware, continuously acquiring a large amount of data synchronized across a large number of channels (>400) at a fast rate (up to 20 kHz/channel) in real time, and interfacing with applications for real-time data analysis and display of electrophysiological data. This DAQ controller was developed specifically for a 384-channel pediatric whole-head magnetoencephalography (MEG) system, but its architecture is useful for wide applications. This controller running in a LabVIEW environment interfaces with microprocessors in the MEG sensor electronics to control their real-time operation. It also interfaces with a real-time MEG analysis software via transmission control protocol/internet protocol, to control the synchronous acquisition and transfer of the data in real time from >400 channels to acquisition and analysis workstations. The successful implementation of this controller for an MEG system with a large number of channels demonstrates the feasibility of employing the present architecture in several other applications.

  20. PERFIL CITOLÓGICO VAGINAL DE OVELHAS DA RAÇA SANTA INÊS NO ACOMPANHAMENTO DO CICLO ESTRAL VAGINAL CYTOLOGY PROFILE FOR ACCOMPANIMENT TO ESTROUS CYCLE IN BREED SANTA INÊS EWES

    Directory of Open Access Journals (Sweden)

    José Adamir Torres de Souza

    2007-09-01

    Full Text Available

    O objetivo deste trabalho foi investigar o perfil citológico vaginal em ovelhas da raça Santa Inês, durante um ciclo estral completo. Selecionaram-se cinco fêmeas cíclicas criadas em sistema semi-intensivo, na Fazenda Pe-dras Santa em Araguaína, TO. Prepararam-se os esfregaços vaginais diariamente nas ovelhas cujo estro foi detectado por um rufião. Confeccionou-se um esfregaço vaginal por fêmea, em lâminas de vidro secas à temperatura ambiente e fixadas em álcool a 95%. Em seguida, foram coradas pelo método panótico rápido. As lâminas foram observadas ao microscópio óptico de luz com aumentos de 10 x e 40 x para contagem de 100 células por lâmina. Analisaram-se as características morfológicas e tintoriais das células epiteliais ao longo do ciclo estral, levando em consideração tanto as variáveis de cada fase do ciclo estral – proestro, estro, metaestro e diestro –, bem como os tipos celulares encon-trados – basal, parabasal, intermediária e anucleada. Os valores foram estudados por meio de ANOVA, ao nível de probabilidade de 5% pelo teste de Tukey. Na fase de estro, notou-se uma diferença do tipo celular superficial anucleada sobre os demais tipos (P<0,05. Concluiu-se que, através da citologia vaginal esfoliativa, podem-se diferenciar as fases do ciclo estral em ovelhas da raça Santa Inês.

    PALAVRAS-CHAVES: Ciclo estral, citologia vaginal, epitélio vaginal, ovelhas.

    The objective of this work was to establish a vaginal cytological profile in ewe of the Race Saint Inês, during a complete estrous cycle. Five created cyclical females in half-intensive system had been selected, in the Farm Rocks Saint, Araguaína, TO. The vaginal smears had been made daily during the estrous cycle, detected for a ruffian. One was confectioned vaginal smears for female, in dry glass slides to the ambient temperature and settled in alcohol 95% and in followed. They had been staining by the fast panótico method

  1. Synchronized High-Speed Vision Sensor Network for Expansion of Field of View

    Directory of Open Access Journals (Sweden)

    Akihito Noda

    2018-04-01

    Full Text Available We propose a 500-frames-per-second high-speed vision (HSV sensor network that acquires frames at a timing that is precisely synchronized across the network. Multiple vision sensor nodes, individually comprising a camera and a PC, are connected via Ethernet for data transmission and for clock synchronization. A network of synchronized HSV sensors provides a significantly expanded field-of-view compared with that of each individual HSV sensor. In the proposed system, the shutter of each camera is controlled based on the clock of the PC locally provided inside the node, and the shutters are globally synchronized using the Precision Time Protocol (PTP over the network. A theoretical analysis and experiment results indicate that the shutter trigger skew among the nodes is a few tens of microseconds at most, which is significantly smaller than the frame interval of 1000-fps-class high-speed cameras. Experimental results obtained with the proposed system comprising four nodes demonstrated the ability to capture the propagation of a small displacement along a large-scale structure.

  2. Multi-application inter-tile synchronization on ultra-high-resolution display walls

    KAUST Repository

    Nam, Sungwon

    2010-01-01

    Ultra-high-resolution tiled-display walls are typically driven by a cluster of computers. Each computer may drive one or more displays. Synchronization between the computers is necessary to ensure that animated imagery displayed on the wall appears seamless. Most tiled-display middleware systems are designed around the assumption that only a single application instance is running in the tiled display at a time. Therefore synchronization can be achieved with a simple solution such as a networked barrier. When a tiled display has to support multiple applications at the same time, however, the simple networked barrier approach does not scale. In this paper we propose and experimentally validate two synchronization algorithms to achieve low-latency, intertile synchronization for multiple applications with independently varying frame rates. The two-phase algorithm is more generally applicable to various highresolution tiled display systems. The one-phase algorithm provides superior results but requires support for the Network Time Protocol and is more CPU-intensive. Copyright 2010 ACM.

  3. Blending Online Asynchronous and Synchronous Learning

    Directory of Open Access Journals (Sweden)

    Lisa C. Yamagata-Lynch

    2014-04-01

    Full Text Available 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 learning environments. The primary research question of this study was: How can the designer/instructor optimize learning experiences for students who are studying about online learning environments in a blended online course relying on both synchronous and asynchronous technologies? I relied on student reflections of course activities during the beginning, middle, and the end of the semester as the primary data source to obtain their insights regarding course experiences. Through the experiences involved in designing and teaching the course and engaging in this study I found that there is room in the instructional technology research community to address strategies for facilitating online synchronous learning that complement asynchronous learning. Synchronous online whole class meetings and well-structured small group meetings can help students feel a stronger sense of connection to their peers and instructor and stay engaged with course activities. In order to provide meaningful learning spaces in synchronous learning environments, the instructor/designer needs to balance the tension between embracing the flexibility that the online space affords to users and designing deliberate structures that will help them take advantage of the flexible space.

  4. Emergent explosive synchronization in adaptive complex networks

    Science.gov (United States)

    Avalos-Gaytán, Vanesa; Almendral, Juan A.; Leyva, I.; Battiston, F.; Nicosia, V.; Latora, V.; Boccaletti, S.

    2018-04-01

    Adaptation plays a fundamental role in shaping the structure of a complex network and improving its functional fitting. Even when increasing the level of synchronization in a biological system is considered as the main driving force for adaptation, there is evidence of negative effects induced by excessive synchronization. This indicates that coherence alone cannot be enough to explain all the structural features observed in many real-world networks. In this work, we propose an adaptive network model where the dynamical evolution of the node states toward synchronization is coupled with an evolution of the link weights based on an anti-Hebbian adaptive rule, which accounts for the presence of inhibitory effects in the system. We found that the emergent networks spontaneously develop the structural conditions to sustain explosive synchronization. Our results can enlighten the shaping mechanisms at the heart of the structural and dynamical organization of some relevant biological systems, namely, brain networks, for which the emergence of explosive synchronization has been observed.

  5. Adaptive Control Algorithm of the Synchronous Generator

    Directory of Open Access Journals (Sweden)

    Shevchenko Victor

    2017-01-01

    Full Text Available The article discusses the the problem of controlling a synchronous generator, namely, maintaining the stability of the control object in the conditions of occurrence of noise and disturbances in the regulatory process. The model of a synchronous generator is represented by a system of differential equations of Park-Gorev, where state variables are computed relative to synchronously rotating d, q-axis. Management of synchronous generator is proposed to organize on the basis of the position-path control using algorithms to adapt with the reference model. Basic control law directed on the stabilizing indicators the frequency generated by the current and the required power level, which is achieved by controlling the mechanical torque on the shaft of the turbine and the value of the excitation voltage of the synchronous generator. Modification of the classic adaptation algorithm using the reference model, allowing to minimize the error of the reference regulation and the model under investigation within the prescribed limits, produced by means of the introduction of additional variables controller adaptation in the model. Сarried out the mathematical modeling of control provided influence on the studied model of continuous nonlinear and unmeasured the disturbance. Simulation results confirm the high level accuracy of tracking and adaptation investigated model with respect to the reference, and the present value of the loop error depends on parameters performance of regulator.

  6. Chaotic synchronization of two complex nonlinear oscillators

    International Nuclear Information System (INIS)

    Mahmoud, Gamal M.; Mahmoud, Emad E.; Farghaly, Ahmed A.; Aly, Shaban A.

    2009-01-01

    Synchronization is an important phenomenon commonly observed in nature. It is also often artificially induced because it is desirable for a variety of applications in physics, applied sciences and engineering. In a recent paper [Mahmoud GM, Mohamed AA, Aly SA. Strange attractors and chaos control in periodically forced complex Duffing's oscillators. Physica A 2001;292:193-206], a system of periodically forced complex Duffing's oscillators was introduced and shown to display chaotic behavior and possess strange attractors. Such complex oscillators appear in many problems of physics and engineering, as, for example, nonlinear optics, deep-water wave theory, plasma physics and bimolecular dynamics. Their connection to solutions of the nonlinear Schroedinger equation has also been pointed out. In this paper, we study the remarkable phenomenon of chaotic synchronization on these oscillator systems, using active control and global synchronization techniques. We derive analytical expressions for control functions and show that the dynamics of error evolution is globally stable, by constructing appropriate Lyapunov functions. This means that, for a relatively large set initial conditions, the differences between the drive and response systems vanish exponentially and synchronization is achieved. Numerical results are obtained to test the validity of the analytical expressions and illustrate the efficiency of these techniques for inducing chaos synchronization in our nonlinear oscillators.

  7. Synchronization coupled systems to complex networks

    CERN Document Server

    Boccaletti, Stefano; del Genio, Charo I; Amann, Andreas

    2018-01-01

    A modern introduction to synchronization phenomena, this text presents recent discoveries and the current state of research in the field, from low-dimensional systems to complex networks. The book describes some of the main mechanisms of collective behaviour in dynamical systems, including simple coupled systems, chaotic systems, and systems of infinite-dimension. After introducing the reader to the basic concepts of nonlinear dynamics, the book explores the main synchronized states of coupled systems and describes the influence of noise and the occurrence of synchronous motion in multistable and spatially-extended systems. Finally, the authors discuss the underlying principles of collective dynamics on complex networks, providing an understanding of how networked systems are able to function as a whole in order to process information, perform coordinated tasks, and respond collectively to external perturbations. The demonstrations, numerous illustrations and application examples will help advanced graduate s...

  8. Method of synchronizing independent functional unit

    Science.gov (United States)

    Kim, Changhoan

    2018-03-13

    A system for synchronizing parallel processing of a plurality of functional processing units (FPU), a first FPU and a first program counter to control timing of a first stream of program instructions issued to the first FPU by advancement of the first program counter; a second FPU and a second program counter to control timing of a second stream of program instructions issued to the second FPU by advancement of the second program counter, the first FPU is in communication with a second FPU to synchronize the issuance of a first stream of program instructions to the second stream of program instructions and the second FPU is in communication with the first FPU to synchronize the issuance of the second stream program instructions to the first stream of program instructions.

  9. Designing Learning Resources in Synchronous Learning Environments

    DEFF Research Database (Denmark)

    Christiansen, Rene B

    2015-01-01

    Computer-mediated Communication (CMC) and synchronous learning environments offer new solutions for teachers and students that transcend the singular one-way transmission of content knowledge from teacher to student. CMC makes it possible not only to teach computer mediated but also to design...... and create new learning resources targeted to a specific group of learners. This paper addresses the possibilities of designing learning resources within synchronous learning environments. The empirical basis is a cross-country study involving students and teachers in primary schools in three Nordic...... Countries (Denmark, Sweden and Norway). On the basis of these empirical studies a set of design examples is drawn with the purpose of showing how the design fulfills the dual purpose of functioning as a remote, synchronous learning environment and - using the learning materials used and recordings...

  10. Adaptive elimination of synchronization in coupled oscillator

    Science.gov (United States)

    Zhou, Shijie; Ji, Peng; Zhou, Qing; Feng, Jianfeng; Kurths, Jürgen; Lin, Wei

    2017-08-01

    We present here an adaptive control scheme with a feedback delay to achieve elimination of synchronization in a large population of coupled and synchronized oscillators. We validate the feasibility of this scheme not only in the coupled Kuramoto’s oscillators with a unimodal or bimodal distribution of natural frequency, but also in two representative models of neuronal networks, namely, the FitzHugh-Nagumo spiking oscillators and the Hindmarsh-Rose bursting oscillators. More significantly, we analytically illustrate the feasibility of the proposed scheme with a feedback delay and reveal how the exact topological form of the bimodal natural frequency distribution influences the scheme performance. We anticipate that our developed scheme will deepen the understanding and refinement of those controllers, e.g. techniques of deep brain stimulation, which have been implemented in remedying some synchronization-induced mental disorders including Parkinson disease and epilepsy.

  11. Phase synchronization in train connection timetables

    Energy Technology Data Exchange (ETDEWEB)

    Fretter, Christoph; Mueller-Hannemann, Matthias [Martin Luther Universitaet, Halle-Wittenberg (Germany); Krumov, Lachezar; Weihe, Karsten [TU Darmstadt (Germany); Huett, Marc-Thorsten [Jacobs University, Bremen (Germany)

    2010-07-01

    Train connection timetables are an important research topic in algorithmics. Finding optimal or near-optimal timetables under the subsidiary conditions of minimizing travel times and other criteria is an important contribution to the functioning of public transportation. In addition to efficiency (given, e.g. by minimal average travel times), the robustness of the timetable, i.e. a minimization of delay propagation, is an important criterion. Here we study the balance of efficiency and robustness in train connection timetables from the perspective of synchronization, exploiting the fact that a major part of the trains run nearly periodically. We find that synchronization is highest at intermediate-sized stations. We argue that this synchronization perspectives opens a new avenue towards an understanding of train connection timetables by representing them as spatiotemporal phase patterns. Robustness and efficiency can then be viewed as properties of this phase pattern.

  12. Synchronous characterization of semiconductor microcavity laser beam.

    Science.gov (United States)

    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.

  13. Synthesizing Modular Invariants for Synchronous Code

    Directory of Open Access Journals (Sweden)

    Pierre-Loic Garoche

    2014-12-01

    Full Text Available In this paper, we explore different techniques to synthesize modular invariants for synchronous code encoded as Horn clauses. Modular invariants are a set of formulas that characterizes the validity of predicates. They are very useful for different aspects of analysis, synthesis, testing and program transformation. We describe two techniques to generate modular invariants for code written in the synchronous dataflow language Lustre. The first technique directly encodes the synchronous code in a modular fashion. While in the second technique, we synthesize modular invariants starting from a monolithic invariant. Both techniques, take advantage of analysis techniques based on property-directed reachability. We also describe a technique to minimize the synthesized invariants.

  14. Trigger delay compensation of beam synchronous sampling

    International Nuclear Information System (INIS)

    Steimel, J.

    1996-05-01

    One of the problems of providing beam feedback in a large accelerator is the lack of beam synchronous trigger signals far from the RF signal source. IF single bucket resolutions are required, a cable extending from the RF source to the other side of the accelerator will not provide a synchronous signal if the RF frequency changes significantly with respect to the cable delay. This paper offers a solution to this problem by locking to the RF, at the remote location, using a digital phase locked loop. Then, the digitized frequency value is used to calculate the phase shift required to remain synchronized to the beam. Results are shown for phase lock to the Fermilab Main Ring RF. 1 ref., 4 figs

  15. Suppression of synchronous resonance for VSGs

    DEFF Research Database (Denmark)

    Yang, Dongsheng; Wu, Heng; Wang, Xiongfei

    2017-01-01

    The virtual synchronous generator (VSG) is an attractive interfacing technique for high-penetration renewable generation. By incorporating the inertia control, the grid-connected voltage-source converter can behave in a similar way with the SGs, which is helpful to enhance the stability of the po......The virtual synchronous generator (VSG) is an attractive interfacing technique for high-penetration renewable generation. By incorporating the inertia control, the grid-connected voltage-source converter can behave in a similar way with the SGs, which is helpful to enhance the stability...... of the power system. However, it is reported that the synchronous frequency resonance (SFR) can be aroused in the VSG due to the resonance peaks in the power control loops at the fundamental frequency. By modelling the power control loop in the dq domain, the mechanism underlying the SFR is studied. It reveals...

  16. Adaptive elimination of synchronization in coupled oscillator

    International Nuclear Information System (INIS)

    Zhou, Shijie; Lin, Wei; Ji, Peng; Feng, Jianfeng; Zhou, Qing; Kurths, Jürgen

    2017-01-01

    We present here an adaptive control scheme with a feedback delay to achieve elimination of synchronization in a large population of coupled and synchronized oscillators. We validate the feasibility of this scheme not only in the coupled Kuramoto’s oscillators with a unimodal or bimodal distribution of natural frequency, but also in two representative models of neuronal networks, namely, the FitzHugh–Nagumo spiking oscillators and the Hindmarsh–Rose bursting oscillators. More significantly, we analytically illustrate the feasibility of the proposed scheme with a feedback delay and reveal how the exact topological form of the bimodal natural frequency distribution influences the scheme performance. We anticipate that our developed scheme will deepen the understanding and refinement of those controllers, e.g. techniques of deep brain stimulation, which have been implemented in remedying some synchronization-induced mental disorders including Parkinson disease and epilepsy. (paper)

  17. Pinning synchronization of a mobile agent network

    International Nuclear Information System (INIS)

    Wang, Lei; Sun, You-xian

    2009-01-01

    We investigate the problem of controlling a group of mobile agents in a plane in order to move them towards a desired orbit via pinning control, in which each agent is associated with a chaotic oscillator coupled with those of neighboring agents, and the pinning strategy is to have the common linear feedback acting on a small fraction of agents by random selection. We explore the effects of the pinning probability, feedback gains and agent density in the pinning synchronization of a mobile agent network under a fast-switching constraint, and perform numerical simulations for validation. In particular, we show that there exists a critical pinning density for network synchronization with an unbounded region: above the threshold, the dynamical network can be controlled by pinning; below it, anarchy prevails. And for the network with a single bounded synchronization region, pinning control has little effect as regards enhancing network synchronizability

  18. Robust outer synchronization between two nonlinear complex networks with parametric disturbances and mixed time-varying delays

    Science.gov (United States)

    Zhang, Chuan; Wang, Xingyuan; Luo, Chao; Li, Junqiu; Wang, Chunpeng

    2018-03-01

    In this paper, we focus on the robust outer synchronization problem between two nonlinear complex networks with parametric disturbances and mixed time-varying delays. Firstly, a general complex network model is proposed. Besides the nonlinear couplings, the network model in this paper can possess parametric disturbances, internal time-varying delay, discrete time-varying delay and distributed time-varying delay. Then, according to the robust control strategy, linear matrix inequality and Lyapunov stability theory, several outer synchronization protocols are strictly derived. Simple linear matrix controllers are designed to driver the response network synchronize to the drive network. Additionally, our results can be applied on the complex networks without parametric disturbances. Finally, by utilizing the delayed Lorenz chaotic system as the dynamics of all nodes, simulation examples are given to demonstrate the effectiveness of our theoretical results.

  19. Measures of Quantum Synchronization in Continuous Variable Systems

    Science.gov (United States)

    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.

  20. Analysis of ECT Synchronization Performance Based on Different Interpolation Methods

    Directory of Open Access Journals (Sweden)

    Yang Zhixin

    2014-01-01

    Full Text Available There are two synchronization methods of electronic transformer in IEC60044-8 standard: impulsive synchronization and interpolation. When the impulsive synchronization method is inapplicability, the data synchronization of electronic transformer can be realized by using the interpolation method. The typical interpolation methods are piecewise linear interpolation, quadratic interpolation, cubic spline interpolation and so on. In this paper, the influences of piecewise linear interpolation, quadratic interpolation and cubic spline interpolation for the data synchronization of electronic transformer are computed, then the computational complexity, the synchronization precision, the reliability, the application range of different interpolation methods are analyzed and compared, which can serve as guide studies for practical applications.

  1. On synchronized regions of discrete-time complex dynamical networks

    International Nuclear Information System (INIS)

    Duan Zhisheng; Chen Guanrong

    2011-01-01

    In this paper, the local synchronization of discrete-time complex networks is studied. First, it is shown that for any natural number n, there exists a discrete-time network which has at least left floor n/2 right floor +1 disconnected synchronized regions for local synchronization, which implies the possibility of intermittent synchronization behaviors. Different from the continuous-time networks, the existence of an unbounded synchronized region is impossible for discrete-time networks. The convexity of the synchronized regions is also characterized based on the stability of a class of matrix pencils, which is useful for enlarging the stability region so as to improve the network synchronizability.

  2. Synchronous gastric neuroendocrine carcinoma and hepatocellular carcinoma

    DEFF Research Database (Denmark)

    Ewertsen, Caroline; Henriksen, Birthe Merete; Hansen, Carsten Palnæs

    2009-01-01

    of synchronous gastric NEC and hepatocellular carcinoma in a patient with several other precancerous lesions is presented. The patient had anaemia, and a gastric tumour and two duodenal polyps were identified on upper endoscopy. A CT scan of the abdomen revealed several lesions in the liver. The lesions were...... invisible on B-mode sonography and real-time sonography fused with CT was used to identify and biopsy one of the lesions. Histology showed hepatocellular carcinoma. A literature search showed that only one case of a hepatocellular carcinoma synchronous with a gastric NEC has been reported previously. TRIAL...

  3. Characteristics of silent countingin synchronized swimmers

    Directory of Open Access Journals (Sweden)

    Sergey V. Leonov

    2012-01-01

    Full Text Available This article describes the temporal characteristics of silent counting as used duringa competition by the Russian youth team of synchronized swimmers. Theathletes listened to the music that accompanied their performance at the competition.Diff erent indices of silent counting were defi ned, such as the beginningand cessation of diff erent periods of counting, counting frequency, the stabilityof the temporal structure of silent counting, the degree of synchronization of silentcounting at diff erent moments during the sports program. We studied therelationship of these characteristics of counting with expert estimates of the athletes’sense of tempo, coordination of movements, and choreographic abilities.

  4. Multithreading for synchronization tolerance in matrix factorization

    International Nuclear Information System (INIS)

    Buttari, Alfredo; Dongarra, Jack; Husbands, Parry; Kurzak, Jakub; Yelick, Katherine

    2007-01-01

    Physical constraints such as power, leakage and pin bandwidth are currently driving the HPC industry to produce systems with unprecedented levels of concurrency. In these parallel systems, synchronization and memory operations are becoming considerably more expensive than before. In this work we study parallel matrix factorization codes and conclude that they need to be re-engineered to avoid unnecessary (and expensive) synchronization. We propose the use of multithreading combined with intelligent schedulers and implement representative algorithms in this style. Our results indicate that this strategy can significantly outperform traditional codes

  5. Carrier and symbol synchronization system performance study

    Science.gov (United States)

    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.

  6. GPS synchronized power system phase angle measurements

    Science.gov (United States)

    Wilson, Robert E.; Sterlina, Patrick S.

    1994-09-01

    This paper discusses the use of Global Positioning System (GPS) synchronized equipment for the measurement and analysis of key power system quantities. Two GPS synchronized phasor measurement units (PMU) were installed before testing. It was indicated that PMUs recorded the dynamic response of the power system phase angles when the northern California power grid was excited by the artificial short circuits. Power system planning engineers perform detailed computer generated simulations of the dynamic response of the power system to naturally occurring short circuits. The computer simulations use models of transmission lines, transformers, circuit breakers, and other high voltage components. This work will compare computer simulations of the same event with field measurement.

  7. Modulated Field Synchronous Generator for Wind Turbines

    Directory of Open Access Journals (Sweden)

    Petru Chioncel

    2013-01-01

    Full Text Available This paper presents a modern electromechanical conversion systemsolution as the modulated field synchronous generator, offering on theone hand, an output voltage with constant frequency in terms of speedvariation of the wind turbine and on the other hand an advantagepower / weight ratio due to the high frequency for which the magneticcircuit of the electric machine is sized. The mathematical model of the modulated field synchronous generator is implemented in MatLABmodeling language, highlighting the command structure on thetransistors bases of the inverter transistors, through which thefunctioning of the electric machine can be studied, especially in terms of the frequency of the delivered voltage.

  8. The transition to chaotic phase synchronization

    DEFF Research Database (Denmark)

    Mosekilde, E.; Laugesen, J. L.; Zhusubaliyev, Zh. T.

    2012-01-01

    The transition to chaotic phase synchronization for a periodically driven spiral-type chaotic oscillator is known to involve a dense set of saddle-node bifurcations. By following the synchronization transition through the cascade of period-doubling bifurcations in a forced Ro¨ssler system...... to the torus doubling bifurcations that take place outside this domain. By examining a physiology-based model of the blood flow regulation to the individual functional unit (nephron) of the kidney we demonstrate how a similar bifurcation structure may arise in this system as a response to a periodically...

  9. Synchronous generator wind energy conversion control system

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, A.L.R. [Wind Energy Group, Recife (Brazil); Lima, A.M.N.; Jacobina, C.B.; Simoes, F.J. [DEE, Campina Grande (Brazil)

    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.

  10. Synchronous Control of Modular Multilevel Converters

    DEFF Research Database (Denmark)

    Oleschuk, Valentin; Blaabjerg, Frede; Bose, Bimal K.

    2002-01-01

    A novel method of direct synchronous pulsewidth modulation (PWM) is applied for control of modular multilevel converters consisting from three standard triphase inverter modules along with an 0.33 p.u. output transformer. The proposed method provides synchronisation of the voltage waveforms...... for each module and the composed voltage at the output of the converter. Multilevel output voltage of the converter has quarter-wave symmetry during the whole range including the zone of overmodulation. Both continuous and discontinuous versions of synchronous PWM, based on vector approach...

  11. Control of bursting synchronization in networks of Hodgkin-Huxley-type neurons with chemical synapses.

    Science.gov (United States)

    Batista, C A S; Viana, R L; Ferrari, F A S; Lopes, S R; Batista, A M; Coninck, J C P

    2013-04-01

    Thermally sensitive neurons present bursting activity for certain temperature ranges, characterized by fast repetitive spiking of action potential followed by a short quiescent period. Synchronization of bursting activity is possible in networks of coupled neurons, and it is sometimes an undesirable feature. Control procedures can suppress totally or partially this collective behavior, with potential applications in deep-brain stimulation techniques. We investigate the control of bursting synchronization in small-world networks of Hodgkin-Huxley-type thermally sensitive neurons with chemical synapses through two different strategies. One is the application of an external time-periodic electrical signal and another consists of a time-delayed feedback signal. We consider the effectiveness of both strategies in terms of protocols of applications suitable to be applied by pacemakers.

  12. Impact of Loss Synchronization on Reliable High Speed Networks: A Model Based Simulation

    Directory of Open Access Journals (Sweden)

    Suman Kumar

    2014-01-01

    Full Text Available Contemporary nature of network evolution demands for simulation models which are flexible, scalable, and easily implementable. In this paper, we propose a fluid based model for performance analysis of reliable high speed networks. In particular, this paper aims to study the dynamic relationship between congestion control algorithms and queue management schemes, in order to develop a better understanding of the causal linkages between the two. We propose a loss synchronization module which is user configurable. We validate our model through simulations under controlled settings. Also, we present a performance analysis to provide insights into two important issues concerning 10 Gbps high speed networks: (i impact of bottleneck buffer size on the performance of 10 Gbps high speed network and (ii impact of level of loss synchronization on link utilization-fairness tradeoffs. The practical impact of the proposed work is to provide design guidelines along with a powerful simulation tool to protocol designers and network developers.

  13. Outer synchronization of complex networks with internal delay and coupling delay via aperiodically intermittent pinning control

    Science.gov (United States)

    Zhang, Chuan; Wang, Xingyuan; Wang, Chunpeng; Xia, Zhiqiu

    This paper concerns the outer synchronization problem between two complex delayed networks via the method of aperiodically intermittent pinning control. Apart from previous works, internal delay and coupling delay are both involved in this model, and the designed intermittent controllers can be aperiodic. The main work in this paper can be summarized as follows: First, two cases of aperiodically intermittent control with constant gain and adaptive gain are implemented, respectively. The intermittent control and pinning control are combined to reduce consumptions further. Then, based on the Lyapunov stability theory, synchronization protocols are given by strict derivation. Especially, the designed controllers are indeed simple and valid in application of theory to practice. Finally, numerical examples put the proposed control methods to the test.

  14. An adaptive transmission protocol for managing dynamic shared states in collaborative surgical simulation.

    Science.gov (United States)

    Qin, J; Choi, K S; Ho, Simon S M; Heng, P A

    2008-01-01

    A force prediction algorithm is proposed to facilitate virtual-reality (VR) based collaborative surgical simulation by reducing the effect of network latencies. State regeneration is used to correct the estimated prediction. This algorithm is incorporated into an adaptive transmission protocol in which auxiliary features such as view synchronization and coupling control are equipped to ensure the system consistency. We implemented this protocol using multi-threaded technique on a cluster-based network architecture.

  15. Blocking Optimality in Distributed Real-Time Locking Protocols

    Directory of Open Access Journals (Sweden)

    Björn Bernhard Brandenburg

    2014-09-01

    Full Text Available Lower and upper bounds on the maximum priority inversion blocking (pi-blocking that is generally unavoidable in distributed multiprocessor real-time locking protocols (where resources may be accessed only from specific synchronization processors are established. Prior work on suspension-based shared-memory multiprocessor locking protocols (which require resources to be accessible from all processors has established asymptotically tight bounds of Ω(m and Ω(n maximum pi-blocking under suspension-oblivious and suspension-aware analysis, respectively, where m denotes the total number of processors and n denotes the number of tasks. In this paper, it is shown that, in the case of distributed semaphore protocols, there exist two different task allocation scenarios that give rise to distinct lower bounds. In the case of co-hosted task allocation, where application tasks may also be assigned to synchronization processors (i.e., processors hosting critical sections, Ω(Φ · n maximum pi-blocking is unavoidable for some tasks under any locking protocol under both suspension-aware and suspension-oblivious schedulability analysis, where Φ denotes the ratio of the maximum response time to the shortest period. In contrast, in the case of disjoint task allocation (i.e., if application tasks may not be assigned to synchronization processors, only Ω(m and Ω(n maximum pi-blocking is fundamentally unavoidable under suspension-oblivious and suspension-aware analysis, respectively, as in the shared-memory case. These bounds are shown to be asymptotically tight with the construction of two new distributed real-time locking protocols that ensure O(m and O(n maximum pi-blocking under suspension-oblivious and suspension-aware analysis, respectively.

  16. The French dosimetry protocol

    International Nuclear Information System (INIS)

    Dutreix, A.

    1985-01-01

    After a general introduction the protocol is divided in five sections dealing with: determination of the quality of X-ray, γ-ray and electron beams; the measuring instrument; calibration of the reference instrument; determination of the reference absorbed dose in the user's beams; determination of the absorbed dose in water at other points, in other conditions. The French protocol is not essentially different from the Nordic protocol and it is based on the experience gained in using both the American and the Nordic protocols. Therefore, only the main difference with the published protocols are discussed. (Auth.)

  17. Protocol Implementation Generator

    DEFF Research Database (Denmark)

    Carvalho Quaresma, Jose Nuno; Probst, Christian W.

    2010-01-01

    Users expect communication systems to guarantee, amongst others, privacy and integrity of their data. These can be ensured by using well-established protocols; the best protocol, however, is useless if not all parties involved in a communication have a correct implementation of the protocol and a...... Generator framework based on the LySatool and a translator from the LySa language into C or Java....... necessary tools. In this paper, we present the Protocol Implementation Generator (PiG), a framework that can be used to add protocol generation to protocol negotiation, or to easily share and implement new protocols throughout a network. PiG enables the sharing, verification, and translation...

  18. Injuries and medical issues in synchronized Olympic sports.

    Science.gov (United States)

    Mountjoy, Margo

    2009-01-01

    Spectators of the Olympic Games can enjoy a wide variety of sports, including strength, team, timed, endurance, and artistic sports. In the Olympic program, there are two synchronized events: synchronized diving and synchronized swimming. The precision of the synchronization of the athlete's movements and skills is an added feature of entertainment. Synchronized athletes have additional training requirements to perfect the synchronization of their skills. The physical demands on the athlete from the repetition of training required for the perfection of synchronization result in injuries unique to these sports. Although both traumatic and overuse injuries occur, overuse injuries are more common. As these disciplines are artistic, judged sports, these athletes also are susceptible to eating disorders and the female athlete triad. This article reviews the training regimen of these athletes and outlines the injuries and health concerns that are common in the synchronized sports.

  19. Hybrid synchronization of two independent chaotic systems on ...

    Indian Academy of Sciences (India)

    Keywords. Hybrid synchronization; complex network; information source; chaotic system. ... encryption and decryption through synchronization. However, the ... Certainly, if the two systems are different, the security would be improved. How.

  20. Making sense of media synchronicity in humanitarian crises

    NARCIS (Netherlands)

    Muhren, W.J.; van den Eede, G.G.P.; van de Walle, B.A.

    2009-01-01

    This paper reintroduces concepts from sensemaking in media synchronicity theory (MST). It focuses on how media should support synchronicity to fit communication needs when making sense of a humanitarian crisis situation. Findings from interviews with senior management of humanitarian aid