975 resultados para repeat synchronization


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Using a panel of 21 OECD countries and 40 years of annual data, we find that countries with similar government budget positions tend to have business cycles that fluctuate more closely. That is, fiscal convergence (in the form of persistently similar ratios of government surplus/deficit to GDP) is systematically associated with more synchronized business cycles. We also find evidence that reduced fiscal deficits increase business cycle synchronization. The Maastricht "convergence criteria," used to determine eligibility for EMU, encouraged fiscal convergence and deficit reduction. They may thus have indirectly moved Europe closer to an optimum currency area, by reducing countries’ abilities to create idiosyncratic fiscal shocks. Our empirical results are economically and statistically significant, and robust.

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A világ 115 országának - köztük 21 OECD-tagország - 40 évnyi adatait vizsgálva, arra a következtetésre jutottunk, hogy a hasonló állami költségvetési pozíciójú országok konjunktúraciklusai között szorosabb együttmozgás mutatható ki. Azaz, a fiskális konvergenciát (amelyet a költségvetési egyenleg GDP-hez viszonyt arányának konvergenciájaként definiáltunk) összehangoltabb konjunktúraciklusokkal lehet összefüggésbe hozni. Kutatásaink során arra is találtunk bizonyítékot, hogy a kisebb mértékű költségvetési deficitek növelik a konjunktúraciklusok együttmozgását. A maastrichti konvergenciakritériumok - amelyek az európai monetáris unió követelményeinek való megfelelést hivatottak meghatározni - a fiskális konvergenciát és a költségvetési deficit csökkentését ösztönözték, s ezzel közvetett módon hozzásegítették Európát egy optimális valutaövezet létrehozásához azáltal, hogy csökkent az egyes országok lehetősége a felelőtlen fiskális politika által gerjesztett sokkhatások létrehozására. Az általunk feltárt empirikus eredmények gazdasági és statisztikai szempontból is szignifikánsak és robusztusak. _____ Using panels of 115 countries of world – including 21 OECD countries – and 40 years of annual data, the authors find that countries with similar government budget positions tend to have business cycles that fluctuate more closely. Thus fiscal convergence (in the form of persistently similar ratios of government surplus/deficit to GDP) is systemati-cally associated with more strongly synchronized business cycles. Evidence is also found that reduced fiscal deficits increase business-cycle synchronization. The Maastricht "con-vergence criteria", used to determine eligibility for EMU, encouraged fiscal convergence and deficit reduction. So they may, indirectly, have moved Europe closer to an optimum currency area, by reducing countries abilities to create idiosyncratic fiscal shocks. The empirical results of the study are economically and statistically significant, and robust.

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The purpose of this research was to demonstrate the applicability of reduced-size STR (Miniplex) primer sets to challenging samples and to provide the forensic community with new information regarding the analysis of degraded and inhibited DNA. The Miniplex primer sets were validated in accordance with guidelines set forth by the Scientific Working Group on DNA Analysis Methods (SWGDAM) in order to demonstrate the scientific validity of the kits. The Miniplex sets were also used in the analysis of DNA extracted from human skeletal remains and telogen hair. In addition, a method for evaluating the mechanism of PCR inhibition was developed using qPCR. The Miniplexes were demonstrated to be a robust and sensitive tool for the analysis of DNA with as low as 100 pg of template DNA. They also proved to be better than commercial kits in the analysis of DNA from human skeletal remains, with 64% of samples tested producing full profiles, compared to 16% for a commercial kit. The Miniplexes also produced amplification of nuclear DNA from human telogen hairs, with partial profiles obtained from as low as 60 pg of template DNA. These data suggest smaller PCR amplicons may provide a useful alternative to mitochondrial DNA for forensic analysis of degraded DNA from human skeletal remains, telogen hairs, and other challenging samples. In the evaluation of inhibition by qPCR, the effect of amplicon length and primer melting temperature was evaluated in order to determine the binding mechanisms of different PCR inhibitors. Several mechanisms were indicated by the inhibitors tested, including binding of the polymerase, binding to the DNA, and effects on the processivity of the polymerase during primer extension. The data obtained from qPCR illustrated a method by which the type of inhibitor could be inferred in forensic samples, and some methods of reducing inhibition for specific inhibitors were demonstrated. An understanding of the mechanism of the inhibitors found in forensic samples will allow analysts to select the proper methods for inhibition removal or the type of analysis that can be performed, and will increase the information that can be obtained from inhibited samples.

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Cannabis sativa is the most frequently used of all illicit drugs in the United States. Cannabis has been used throughout history for its stems in the production of hemp fiber, for its seed for oil and food, and for its buds and leaves as a psychoactive drug. Short tandem repeats (STRs), were chosen as molecular markers because of their distinct advantages over other genetic methods. STRs are co-dominant, can be standardized such that reproducibility between laboratories can be easily achieved, have a high discrimination power and can be multiplexed. ^ In this study, six STR markers previously described for Cannabis were multiplexed into one reaction. The multiplex reaction was able to individualize 98 Cannabis samples (14 hemp and 84 marijuana, authenticated as originating from 33 of the 50 United States) and detect 29 alleles averaging 4.8 alleles per loci. The data did not relate the samples from the same state to each other. This is the first study to report a single reaction six-plex and apply it to the analysis of almost 100 Cannabis samples of known geographic collection site. ^

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Breast cancer is the second leading cause of cancer death in United States women, estimated to be diagnosed in 1 out of 8 women in their lifetime. Screening mammography detects breast cancer in its pre-clinical stages when treatment strategies have the greatest chance of success, and is currently the only population-wide prevention method proven to reduce the morbidity and mortality associated with breast cancer. Research has shown that the majority of women are not screened annually, with estimates ranging front 6% - 30% of eligible women receiving all available annual mammograms over a 5-year or greater time frame. Health behavior theorists believe that perception of risk/susceptibility to a disease influences preventive health behavior, in this case, screening mammography The purpose of this dissertation is to examine the association between breast cancer risk perception and repeat screening mammography using a structural equation modeling (SEM) framework. A series of SEM multivariate regressions were conducted using self-reported, nationally representative data from the 2005 National Health Interview Survey. Interaction contrasts were tested to measure the potential moderating effects of variables which have been shown to be predictive of mammography use (physician recommendation, economic barriers, structural barriers, race/ethnicity) on the association between breast cancer risk perception and repeat mammography, while controlling for the covariates of age, income, region, nativity, and educational level. Of the variables tested for moderation, results of the SEM analyses identify physician recommendation as the only moderator of the relationship between risk perception and repeat mammography, thus the potentially most effective point of intervention to increase mammography screening, and decrease the morbidity and mortality associated with breast cancer. These findings expand the role of the physician from recommendation to one of attenuating the effect of risk perception and increasing repeat screening. The long range application of the research is the use of the SEM methodology to identify specific points of intervention most likely to increase preventive behavior in population-wide research, allowing for the most effective use of intervention funds.^

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Every year, 16 million women aged 15 to 19 years give birth globally. Adolescent births account for 11% of all births globally and 23% of the overall burden of disability and diseases due to pregnancy and childbirth. In the United States, 750,000 adolescents (15-19 years) become pregnant each year, making the United States the developed country with the highest rates of adolescent pregnancy. The economic burden of adolescent pregnancy in the U. S. is $7-15 billion per year. Adolescent pregnancy brings risks associated with pregnancy induced hypertension, preterm infants, maternal and neonatal mortality. Social factors include poverty, low educational levels, alcohol, and drug use. Between 30-50% of adolescent mothers who have a first birth before age 18 years will have a second child within 12 to 24 months. Subsequent adolescent pregnancies compound fetal and maternal risks. Many vulnerable adolescent mothers succumb to external pressures and have a repeat adolescent pregnancy while others are able to overcome the challenges of an adolescent pregnancy and prevent a repeat adolescent pregnancy. This cross sectional survey designed study investigated the effects of resilience and social influences on contraceptive use or abstinence by Black and Hispanic adolescent parenting mothers to prevent a repeat adolescent pregnancy. 140 adolescent mothers were recruited from three postpartum units of a tertiary hospital system in Miami, Florida. The Wagnild and Young Resilience Scale and the Adolescent Social Influence Scale were used to measure resilience and social influences, respectively. Demographic data, length of labor, plan for contraceptive use or abstinence were measured by an investigator developed instrument. Point biserial correlation showed a significant positive correlation between Black adolescent mothers' resilience and contraceptive use (r =.366, p2(11, N=133) = 27.08, p =.004. (OR = .28). These results indicate a need for interventional strategies to maximize resilience in parenting adolescents to prevent a repeat adolescent pregnancy.

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A 21.6 Gbit/s 1.78 bit/s/Hz OFDM signal is transmitted over 50 Km of fiber without using DSP in the transmitter or the receiver. The synchronization scheme only requires one PLL to synchronize all the subcarriers.

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In this article we present a numerical study of the collective dynamics in a population of coupled semiconductor lasers with a saturable absorber, operating in the excitable regime under the action of additive noise. We demonstrate that temporal and intensity synchronization takes place in a broad region of the parameter space and for various array sizes. The synchronization is robust and occurs even for a set of nonidentical coupled lasers. The cooperative nature of the system results in a self-organization process which enhances the coherence of the single element of the population too and can have broad impact for detection purposes, for building all-optical simulators of neural networks and in the field of photonics-based computation.

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Trinucleotide repeat (TNR) expansion is the cause of more than 40 types of human neurodegenerative diseases such as Huntington’s disease. Recent studies have linked TNR expansion with oxidative DNA damage and base excision repair (BER). In this research, we provided the first evidence that oxidative DNA damage can induce CAG repeat deletion/contraction via BER. We found that BER of an oxidized DNA base lesion, 8-oxoguanine in a CAG repeat tract, resulted in the formation of a CTG hairpin at the template strand. DNA polymerase β (pol b) then skipped over the hairpin creating a 5’-flap that was cleaved by flap endonuclease 1 (FEN1) leading to CAG repeat deletion. To further investigate whether BER may help to shorten an expanded TNR tract, we examined BER in a CAG repeat hairpin loop. We found that 8-oxoguanine DNA glycosylase removed the oxidized base located in the loop region of the hairpin leaving an abasic site. Apurinic/apyrimidinic (AP) endonuclease 1 then incised the 5’-end of the abasic site leaving a nick in the loop. This further converted the hairpin into an intermediate with a 3’-flap and a 5’-flap. As a 5’-3’ endonuclease, FEN1 cleaved the 5’-flap, whereas a 3’-5’ endonuclease, Mus81/Eme1, removed the 3’-flap. The coordination between FEN1 and Mus81/Eme1 ultimately resulted in removal of a CAG repeat hairpin attenuating or preventing TNR expansion. To further explore if pol β bypass of an oxidized base lesion, 5’,8-cyclodeoxyadenosine, may affect TNR instability, we examined pol β DNA synthesis in bypassing this base lesion and found that the lesion preferentially induced TNR deletion during BER and Okazaki fragment maturation. The repeat deletion was mediated by the formation of a loop in the template strand induced specifically by the damage. Pol β then skipped over the loop structure creating a 5’-flap that was efficiently removed by FEN1 leading to repeat deletion. Our study demonstrates that pol β-mediated BER plays an important role in mediating TNR deletion and removing a TNR hairpin to prevent TNR expansion. Our research provides a molecular basis for further developing BER as a target for prevention and treatment of neurodegenerative diseases caused by TNR expansion.

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Following inspections in 2013 of all police forces, Her Majesty’s Inspectorate of Constabulary found that one-third of forces could not provide data on repeat victims of domestic abuse (DA) and concluded that in general there were ambiguities around the term ‘repeat victim’ and that there was a need for consistent and comparable statistics on DA. Using an analysis of police-recorded DA data from two forces, an argument is made for including both offences and non-crime incidents when identifying repeat victims of DA. Furthermore, for statistical purposes the counting period for repeat victimizations should be taken as a rolling 12 months from first recorded victimization. Examples are given of summary statistics that can be derived from these data down to Community Safety Partnership level. To reinforce the need to include both offences and incidents in analyses, repeat victim chronologies from policerecorded data are also used to briefly examine cases of escalation to homicide as an example of how they can offer new insights and greater scope for evaluating risk and effectiveness of interventions.

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The synchronization of oscillatory activity in networks of neural networks is usually implemented through coupling the state variables describing neuronal dynamics. In this study we discuss another but complementary mechanism based on a learning process with memory. A driver network motif, acting as a teacher, exhibits winner-less competition (WLC) dynamics, while a driven motif, a learner, tunes its internal couplings according to the oscillations observed in the teacher. We show that under appropriate training the learner motif can dynamically copy the coupling pattern of the teacher and thus synchronize oscillations with the teacher. Then, we demonstrate that the replication of the WLC dynamics occurs for intermediate memory lengths only. In a unidirectional chain of N motifs coupled through teacher-learner paradigm the time interval required for pattern replication grows linearly with the chain size, hence the learning process does not blow up and at the end we observe phase synchronized oscillations along the chain. We also show that in a learning chain closed into a ring the network motifs come to a consensus, i.e. to a state with the same connectivity pattern corresponding to the mean initial pattern averaged over all network motifs.

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To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independent method is used to cross-check that indeed we reach a nanosecond-scale timing accuracy by this correction. First, we operate a "beacon transmitter" which emits defined sine waves detected by AERA antennas recorded within the physics data. The relative phasing of these sine waves can be used to correct for GPS clock drifts. In addition to this, we observe radio pulses emitted by commercial airplanes, the position of which we determine in real time from Automatic Dependent Surveillance Broadcasts intercepted with a software-defined radio. From the known source location and the measured arrival times of the pulses we determine relative timing offsets between radio detector stations. We demonstrate with a combined analysis that the two methods give a consistent timing calibration with an accuracy of 2 ns or better. Consequently, the beacon method alone can be used in the future to continuously determine and correct for GPS clock drifts in each individual event measured by AERA.