850 resultados para Adjusted Average Time to Signal
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Time to flowering and maturity is an important adaptive feature in annual crops, including cowpeas (Vigna unguiculata (L.) Walp.). In West and Central Africa, photoperiod is the most important environmental variable affecting time to flowering in cowpea. The inheritance of time from sowing to flowering (f) in cowpeas was studied by crossing a photoperiod-sensitive genotype Kanannnado to a photoperiod-insensitive variety IT97D-941-1. Sufficient seed of F-1, F-2, F-3 and backcross populations were generated. The parental, F-1, F-2, F-3 and the backcross populations were screened for f under long natural days (mean daylength 13.4 h per day) in the field and the parents, F-1, F-2 and backcross populations under short day (10 h per day) conditions. The result of the screening showed that photoperiod in the field was long enough to delay flowering of photoperiod-sensitive genotypes. Photoperiod-sensitivity was found to be partially dominant to insensitivity. Frequency distribution of the trait in the various populations indicated quantitative inheritance. Additive (d) and additive x dominance (j) interactions were the most important gene actions conditioning time to flowering. A narrow sense heritability of 86% was estimated for this trait. This will result in 26 days gain in time to flowering with 5% selection intensity from the F-2 to F-3 generation. At least seven major gene pairs, with an average delay of 6 days each, were estimated to control time to flowering in this cross.
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Statement of problem. The use of ultrasonic tips has become an alternative for cavity preparation. However, there are concerns about this type of device, particularly with respect to intrapulpal temperatures and cavity preparation time.Purpose. The purpose of this study was to analyze pulpal temperature increases generated by an ultrasonic cavity preparation with chemical vapor deposition (CVD) tips, in comparison to preparation with a high-speed handpiece with a diamond rotary cutting instrument. The time required to complete the cavity preparation with each system was also evaluated.Material and methods. Thermocouples were positioned in the pulp chamber of 20 extracted human third molars. Slot-type cavities (3 x 3 x 2 mm) were prepared on the buccal and the lingual surfaces of each tooth. The test groups were: high-speed cavity preparation with diamond rotary cutting instruments (n = 20) and ultrasonic cavity preparation with CVD points (n = 20). During cavity preparation, the increases In pulpal temperature, and the time required for the preparation, were recorded and analyzed by Student's t test for paired samples (alpha = .05).Results. The average pulpal temperature increases were 4.3 degrees C for the high-speed preparation and 3.8 degrees C for the ultrasonic preparation, which were statistically similar (P = .052). However, significant differences were found (P < .001) for the time expended (3.3 minutes for the high-speed bur and 13.77 minutes for the ultrasound device).Conclusions. The intrapulpal temperatures produced during cavity preparation by ultrasonic tips versus high-speed bur preparation were similar. However, the use of the ultrasonic device required 4 times longer for the completion of a cavity preparation.
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Objective The purpose of this study was to identify the clinical factors associated with time to hCG remission among women with low-risk postmolar GTN. Methods This study included a non-concurrent cohort of 328 patients diagnosed with low-risk postmolar GTN according to FIGO 2002 criteria. Associations of time to hCG remission with history of prior mole, molar histology, time to persistence, use of D&C at persistence, presence of metastatic disease, FIGO score, hCG values at persistence, type of first line therapy and use of multiagent chemotherapy were investigated with both univariate and multivariate analyses. Results Overall median time to remission was 46 days. Ten percent of the patients required multi-agent chemotherapy to achieve hCG remission. Multivariate analysis incorporating the variables significant on univariate analysis confirmed that complete molar histology (HR 1.45), metastatic disease (HR 1.66), use of multi-agent therapy (HR 2.00) and FIGO score (HR 1.82) were associated with longer time to remission. There was a linear relationship between FIGO score and time to hCG remission. Each 1-point increment in FIGO score was associated with an average 17-day increase in hCG remission time (95% CI: 12.5-21.6). Conclusions Complete mole histology prior to GTN, presence of metastatic disease, use of multi-agent therapy and higher FIGO score were independent factors associated with longer time to hCG remission in low-risk GTN. Identifying the prognostic factors associated with time to remission and effective counseling may help improve treatment planning and reduce anxiety in patients and their families. © 2013 Elsevier Inc. All rights reserved.
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We studied the time interval between starting tuberculosis treatment and commencing antiretroviral treatment (ART) in HIV-infected patients (n = 1433; median CD4 count 71 cells per microliter, interquartile range: 32-132) attending 3 South African township ART services between 2002 and 2008. The overall median delay was 2.66 months (interquartile range: 1.58-4.17). In adjusted analyses, delays varied between treatment sites but were shorter for patients with lower CD4 counts and those treated in more recent calendar years. During the most recent period (2007-2008), 4.7%, 19.7%, and 51.1% of patients started ART within 2, 4, and 8 weeks of tuberculosis treatment, respectively. Operational barriers must be tackled to permit further acceleration of ART initiation as recommended by 2010 WHO ART guidelines.
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BACKGROUND AND PURPOSE: The effect of thrombolysis depends on the time from stroke onset to treatment and therefore also on the time when patients come to the hospital. This study was designed to analyze the variables that influence the time from symptom onset to admission (TTA) to the stroke unit. METHODS: We evaluated the medical records of 615 consecutive stroke or transient ischemic attack (TIA) patients admitted to our neurological department within 48 hours after symptom onset. RESULTS: The median TTA was 180 minutes. Referral by emergency medical services (EMS; P<0.001), high National Institutes of Health Stroke Scale (NIHSS) scores (P<0.001), strokes in the carotid territory (P<0.001), and strokes not attributable to small vessel disease (P<0.001) were associated with shorter prehospital delays. The TTA was adjusted for travel times (adjTTA), and all these variables remained significantly associated with time to admission. In addition, patients with previous experience with stroke or TIA had longer adjTTA (P=0.028). Regression analysis confirmed the independent association between referral by EMS (P=0.010), high NIHSS scores (P<0.001), carotid territory stroke (P<0.001), and first-ever cerebrovascular event (P=0.022) with shorter adjTTA. CONCLUSIONS: Factors such as NIHSS scores and stroke location influence the time to admission but, unlike referral pathways, cannot be modified. Educational programs and stroke campaigns should therefore not only teach typical and less common stroke symptoms and signs but also that EMS provides the fastest means of transportation to a stroke unit and the best chances to get treatment early.
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BACKGROUND About 80% of patients with Crohn's disease (CD) require bowel resection and up to 65% will undergo a second resection within 10 years. This study reports clinical risk factors for resection surgery (RS) and repeat RS. METHODS Retrospective cohort study, using data from patients included in the Swiss Inflammatory Bowel Disease Cohort. Cox regression analyses were performed to estimate rates of initial and repeated RS. RESULTS Out of 1,138 CD cohort patients, 417 (36.6%) had already undergone RS at the time of inclusion. Kaplan-Meier curves showed that the probability of being free of RS was 65% after 10 years, 42% after 20 years, and 23% after 40 years. Perianal involvement (PA) did not modify this probability to a significant extent. The main adjusted risk factors for RS were smoking at diagnosis (hazard ratio (HR) = 1.33; p = 0.006), stricturing with vs. without PA (HR = 4.91 vs. 4.11; p < 0.001) or penetrating disease with vs. without PA (HR = 3.53 vs. 4.58; p < 0.001). The risk factor for repeat RS was penetrating disease with vs. without PA (HR = 3.17 vs. 2.24; p < 0.05). CONCLUSION The risk of RS was confirmed to be very high for CD in our cohort. Smoking status at diagnosis, but mostly penetrating and stricturing diseases increase the risk of RS.
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Performance on interval timing is often explained by the assumption of an internal clock based on neural counting. According to this account, a neural pacemaker generates pulses, and the number of pulses relating to a physical time interval is recorded by a counter. Thus, the number of accumulated pulses is the internal representation of this interval. Several studies demonstrated that large visual stimuli are perceived to last longer than smaller ones presented for the same duration. The present study was designed to investigate whether nontemporal visual stimulus size directly affects the internal clock. For this purpose, a temporal reproduction task was applied. Sixty participants were randomly assigned to one of two experimental conditions with stimulus size being experimentally varied within either the target or the reproduction interval. A direct effect of nontemporal stimulus size on the pacemaker-counter system should become evident irrespective of whether stimulus size was experimentally varied within the target or the reproduction interval. An effect of nontemporal stimulus size on reproduced duration only occurred when stimulus size was varied during the target interval. This finding clearly argues against the notion that nontemporal visual stimulus size directly affects the internal clock. Furthermore, our findings ruled out a decisional bias as a possible cause of the observed differential effect of stimulus size on reproduced duration. Rather the effect of stimulus size appeared to originate from the memory stage of temporal information processing at which the timing signal from the pacemaker-counter component is encoded in reference memory.
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Rainfall variability occurs over a wide range of temporal scales. Knowledge and understanding of such variability can lead to improved risk management practices in agricultural and other industries. Analyses of temporal patterns in 100 yr of observed monthly global sea surface temperature and sea level pressure data show that the single most important cause of explainable, terrestrial rainfall variability resides within the El Nino-Southern Oscillation (ENSO) frequency domain (2.5-8.0 yr), followed by a slightly weaker but highly significant decadal signal (9-13 yr), with some evidence of lesser but significant rainfall variability at interclecadal time scales (15-18 yr). Most of the rainfall variability significantly linked to frequencies tower than ENSO occurs in the Australasian region, with smaller effects in North and South America, central and southern Africa, and western Europe. While low-frequency (LF) signals at a decadal frequency are dominant, the variability evident was ENSO-like in all the frequency domains considered. The extent to which such LF variability is (i) predictable and (ii) either part of the overall ENSO variability or caused by independent processes remains an as yet unanswered question. Further progress can only be made through mechanistic studies using a variety of models.
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The epidemic of obesity is impacting an increasing proportion of children, adolescents and adults with a common feature being low levels of physical activity (PA). Despite having more knowledge than ever before about the benefits of PA for health and the growth and development of youngsters, we are only paying lip-service to the development of motor skills in children. Fun, enjoyment and basic skills are the essential underpinnings of meaningful participation in PA. A concurrent problem is the reported increase in sitting time with the most common sedentary behaviors being TV viewing and other screen-based games. Limitations of time have contributed to a displacement of active behaviors with inactive pursuits, which has contributed to reductions in activity energy expenditure. To redress the energy imbalance in overweight and obese children, we urgently need out-of-the-box multisectoral solutions. There is little to be gained from a shame and blame mentality where individuals, their parents, teachers and other groups are singled out as causes of the problem. Such an approach does little more than shift attention from the main game of prevention and management of the condition, which requires a concerted, whole-of-government approach (in each country). The failure to support and encourage all young people to participate in regular PA will increase the chance that our children will live shorter and less healthy lives than their parents. In short, we need novel environmental approaches to foster a systematic increase in PA. This paper provides examples of opportunities and challenges for PA strategies to prevent obesity with a particular emphasis on the school and home settings.
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A hip fracture causes permanent changes to life style for older people. Further, two important mortality indicators found post operatively for this group include, the time until surgery after fracture, and pre-operative health status prior to surgery, yet no research is available investigating relationships between time to surgery and health status. The researchers aimed to establish the health status risks for patients aged over 65 years with a non-pathological hip fracture to guide nursing care interventions. A prospective cohort design was used to investigate relationships between time to surgery and measures on pre-operative health status indicators including, skin integrity risk, vigor, mental state, bowel function and continence. Twenty-nine patients with a mean age in years of 81.93 (SD,9.49), were recruited. The mean number of hours from time 1 assessment to surgery was 52.72 (SD,58.35) and the range was 1 hour to 219 hours. At Time 2, the mean scores of vigor and skin integrity risk were significantly higher, indicating poorer health status. A change in health status occurred but possibly due to the small sample size it was difficult to relate this result to time. However the results informed preoperative care prior to surgery, for this group.
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The phase of an analytic signal constructed from the autocorrelation function of a signal contains significant information about the shape of the signal. Using Bedrosian's (1963) theorem for the Hilbert transform it is proved that this phase is robust to multiplicative noise if the signal is baseband and the spectra of the signal and the noise do not overlap. Higher-order spectral features are interpreted in this context and shown to extract nonlinear phase information while retaining robustness. The significance of the result is that prior knowledge of the spectra is not required.
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The statutory demand procedure has been a part of our corporate law from its earliest modern formulations and it has been suggested, albeit anecdotally, that under the current regime, it gives rise to more litigation than any other part of the Corporations Act. Despite this there has been a lack of consideration of the underlying policy behind the procedure in both the case law and literature; both of which are largely centred on the technical aspects of the process. The purpose of this article is to examine briefly the process of the statutory demand in the context of the current insolvency law in Australia. This paper argues that robust analysis of the statutory demand regime is overdue. The paper first sets out to discover if there is a policy justification for the process and to articulate what that may be. Second, it will briefly examine the current legislation and argue that the structure actually encourages litigation which is arguably undesirable in the context of insolvency. In particular we will ask if the current rigid legal regime is appropriate for dealing efficiently with the highly charged atmosphere of contested insolvency. Third, it will examine suggested reforms in this area as to whether they might be a way forward.