DURATION LIMIT OF LASER PULSES EMITTED FROM A Ce-DOPED CRYSTAL SHORT CAVITY

Directory of Open Access Journals (Sweden)

Le Hoang Hai

2017-11-01

Full Text Available Based on the rate equation set for broadband cavities, the dependence of pulse duration on cavity and pumping parameters is analyzed. The cavity uses a Ce-doped crystal as a gain medium. Computation results show the variation of the pulse width with the change of cavity length, mirror reflectivity, pumping energy and pumping pulse duration. A significant influence of multiple-pulse operation in limiting pulse duration is realized and a pulse-width of the order 200 ps is found to be the limit for the direct generation of ultraviolet single picosecond pulses from a Ce:LLF short cavity.

Arousal and exposure duration affect forward step initiation

Directory of Open Access Journals (Sweden)

Daniëlle eBouman

2015-11-01

Full Text Available Emotion influences parameters of goal-directed whole-body movements in several ways. For instance, previous research has shown that approaching (moving toward pleasant stimuli is easier compared to approaching unpleasant stimuli. However, some studies found that when emotional pictures are viewed for a longer time, approaching unpleasant stimuli may in fact be facilitated. The effect of viewing duration may modulate whole-body approach movement in previous research but this has not been investigated before. In the current study, participants initiated a step forward after viewing neutral, high-arousal pleasant and high-arousal unpleasant stimuli. The viewing duration of the stimuli was set to 7 different durations, varying from 100 to 4000ms. Valence and arousal scores were collected for all stimuli.The results indicate that both viewing duration and the arousal of the stimuli influence kinematic parameters in forward gait initiation. Specifically, longer viewing duration, compared to shorter viewing duration, (a diminished the step length and peak velocity in both neutral and emotional stimuli, (b increased reaction time in neutral stimuli and, (c decreased reaction time in pleasant and unpleasant stimuli. Strikingly, no differences were found between high-arousal pleasant and high-arousal unpleasant stimuli. In other words, the valence of the stimuli did not influence kinematic parameters of forward step initiation. In contrast, the arousal level (neutral: low; pleasant and unpleasant: high explained the variance found in the results. The kinematics of forward gait initiation seemed to be reflected in the subjective arousal scores, but not the valence scores. So it seems arousal affects forward gait initiation parameters more strongly than valence. In addition, longer viewing duration seemed to cause diminished alertness, affecting GI parameters. These results shed new light on the prevailing theoretical interpretations regarding approach

An Adaptive Pseudospectral Method for Fractional Order Boundary Value Problems

Directory of Open Access Journals (Sweden)

Mohammad Maleki

2012-01-01

Full Text Available An adaptive pseudospectral method is presented for solving a class of multiterm fractional boundary value problems (FBVP which involve Caputo-type fractional derivatives. The multiterm FBVP is first converted into a singular Volterra integrodifferential equation (SVIDE. By dividing the interval of the problem to subintervals, the unknown function is approximated using a piecewise interpolation polynomial with unknown coefficients which is based on shifted Legendre-Gauss (ShLG collocation points. Then the problem is reduced to a system of algebraic equations, thus greatly simplifying the problem. Further, some additional conditions are considered to maintain the continuity of the approximate solution and its derivatives at the interface of subintervals. In order to convert the singular integrals of SVIDE into nonsingular ones, integration by parts is utilized. In the method developed in this paper, the accuracy can be improved either by increasing the number of subintervals or by increasing the degree of the polynomial on each subinterval. Using several examples including Bagley-Torvik equation the proposed method is shown to be efficient and accurate.

Auditory stimulus timing influences perceived duration of co-occurring visual stimuli

Directory of Open Access Journals (Sweden)

Vincenzo eRomei

2011-09-01

Full Text Available There is increasing interest in multisensory influences upon sensory-specific judgements, such as when auditory stimuli affect visual perception. Here we studied whether the duration of an auditory event can objectively affect the perceived duration of a co-occurring visual event. On each trial, participants were presented with a pair of successive flashes and had to judge whether the first or second was longer. Two beeps were presented with the flashes. The order of short and long stimuli could be the same across audition and vision (audiovisual congruent or reversed, so that the longer flash was accompanied by the shorter beep and vice versa (audiovisual incongruent; or the two beeps could have the same duration as each other. Beeps and flashes could onset synchronously or asynchronously. In a further control experiment, the beep durations were much longer (tripled than the flashes. Results showed that visual duration-discrimination sensitivity (d' was significantly higher for congruent (and significantly lower for incongruent audiovisual synchronous combinations, relative to the visual only presentation. This effect was abolished when auditory and visual stimuli were presented asynchronously, or when sound durations tripled those of flashes. We conclude that the temporal properties of co-occurring auditory stimuli influence the perceived duration of visual stimuli and that this can reflect genuine changes in visual sensitivity rather than mere response bias.

Absence of an increase in the duration of the circadian melatonin secretory episode in totally blind human subjects

Science.gov (United States)

Klerman, E. B.; Zeitzer, J. M.; Duffy, J. F.; Khalsa, S. B.; Czeisler, C. A.

2001-01-01

The daily rhythm of melatonin influences multiple physiological measures, including sleep tendency, circadian rhythms, and reproductive function in seasonally breeding mammals. The biological signal for photoperiodic changes in seasonally breeding mammals is a change in the duration of melatonin secretion, which in a natural environment reflects the different durations of daylight across the year, with longer nights leading to a longer duration of melatonin secretion. These seasonal changes in the duration of melatonin secretion do not simply reflect the known acute suppression of melatonin secretion by ocular light exposure, but also represent long-term changes in the endogenous nocturnal melatonin episode that persist in constant conditions. As the eyes of totally blind individuals do not transmit ocular light information, we hypothesized that the duration of the melatonin secretory episode in blind subjects would be longer than those in sighted individuals, who are exposed to light for all their waking hours in an urban environment. We assessed the melatonin secretory profile during constant posture, dim light conditions in 17 blind and 157 sighted adults, all of whom were healthy and using no prescription or nonprescription medications. The duration of melatonin secretion was not significantly different between blind and sighted individuals. Healthy blind individuals after years without ocular light exposure do not have a longer duration of melatonin secretion than healthy sighted individuals.

Effect of introduction of electronic patient reporting on the duration of ambulance calls.

Science.gov (United States)

Kuisma, Markku; Väyrynen, Taneli; Hiltunen, Tuomas; Porthan, Kari; Aaltonen, Janne

2009-10-01

We examined the effect of the change from paper records to the electronic patient records (EPRs) on ambulance call duration. We retrieved call duration times 6 months before (group 1) and 6 months after (group 2) the introduction of EPR. Subgroup analysis of group 2 was fulfilled depending whether the calls were made during the first or last 3 months after EPR introduction. We analyzed 37 599 ambulance calls (17 950 were in group 1 and 19 649 were in group 2). The median call duration in group 1 was 48 minutes and in group 2 was 49 minutes (P = .008). In group 2, call duration was longer during the first 3 months after EPR introduction. In multiple linear regression analysis, urgency category (P introduction was noticed, reflecting adaptation process to a new way of working.

ParaExp Using Leapfrog as Integrator for High-Frequency Electromagnetic Simulations

Science.gov (United States)

Merkel, M.; Niyonzima, I.; Schöps, S.

2017-12-01

Recently, ParaExp was proposed for the time integration of linear hyperbolic problems. It splits the time interval of interest into subintervals and computes the solution on each subinterval in parallel. The overall solution is decomposed into a particular solution defined on each subinterval with zero initial conditions and a homogeneous solution propagated by the matrix exponential applied to the initial conditions. The efficiency of the method depends on fast approximations of this matrix exponential based on recent results from numerical linear algebra. This paper deals with the application of ParaExp in combination with Leapfrog to electromagnetic wave problems in time domain. Numerical tests are carried out for a simple toy problem and a realistic spiral inductor model discretized by the Finite Integration Technique.

Self-adaptive numerical integrator for analytic functions

International Nuclear Information System (INIS)

Garribba, S.; Quartapelle, L.; Reina, G.

1978-01-01

A new adaptive algorithm for the integration of analytical functions is presented. The algorithm processes the integration interval by generating local subintervals whose length is controlled through a feedback loop. The control is obtained by means of a relation derived on an analytical basis and valid for an arbitrary integration rule: two different estimates of an integral are used to compute the interval length necessary to obtain an integral estimate with accuracy within the assigned error bounds. The implied method for local generation of subintervals and an effective assumption of error partition among subintervals give rise to an adaptive algorithm provided with a highly accurate and very efficient integration procedure. The particular algorithm obtained by choosing the 6-point Gauss-Legendre integration rule is considered and extensive comparisons are made with other outstanding integration algorithms

Dietary specialization is linked to reduced species durations in North American fossil canids

Science.gov (United States)

Balisi, Mairin; Casey, Corinna; Van Valkenburgh, Blaire

2018-04-01

How traits influence species persistence is a fundamental question in ecology, evolution and palaeontology. We test the relationship between dietary traits and both species duration and locality coverage over 40 million years in North American canids, a clade with considerable ecomorphological disparity and a dense fossil record. Because ecomorphological generalization-broad resource use-may enable species to withstand disturbance, we predicted that canids of average size and mesocarnivory would exhibit longer durations and wider distributions than specialized larger or smaller species. Second, because locality coverage might reflect dispersal ability and/or survivability in a range of habitats, we predicted that high coverage would correspond with longer durations. We find a nonlinear relationship between species duration and degree of carnivory: species at either end of the carnivory spectrum tend to have shorter durations than mesocarnivores. Locality coverage shows no relationship with size, diet or duration. To test whether generalization (medium size, mesocarnivory) corresponds to an adaptive optimum, we fit trait evolution models to previously generated canid phylogenies. Our analyses identify no single optimum in size or diet. Instead, the primary model of size evolution is a classic Cope's Rule increase over time, while dietary evolution does not conform to a single model.

Sleep duration is associated with sperm chromatin integrity among young men in Chongqing, China.

Science.gov (United States)

Wang, Xiaogang; Chen, Qing; Zou, Peng; Liu, Taixiu; Mo, Min; Yang, Huan; Zhou, Niya; Sun, Lei; Chen, Hongqiang; Ling, Xi; Peng, Kaige; Ao, Lin; Yang, Huifang; Cao, Jia; Cui, Zhihong

2017-10-09

This study explores whether sleep duration is associated with sperm chromatin integrity. To do so, we conducted a three-phase panel study of 796 male volunteers from colleges in Chongqing (China) from 2013 to 2015. Sleep duration was measured using a modified Munich Chronotype Questionnaire. Sperm DNA integrity was examined via Sperm Chromatin Structure Assay and Comet assay. Setting 7-7.5 h day -1 of sleep duration as a reference, either longer or shorter sleep duration was associated negatively with high DNA stainability (HDS) (P = 0.009), which reflected the immaturity of sperm chromatin. The volunteers with > 9.0 h day -1 sleep and those with ≤ 6.5 h day -1 sleep had 40.7 and 30.3% lower HDS than did volunteers with 7-7.5 h day -1 sleep. No association was found between sleep duration and DNA fragmentation index or Comet assay parameters. This study suggests that sleep duration is associated with sperm chromatin integrity. Further studies are required to validate these findings and investigate the mechanism underlying this association. © 2017 European Sleep Research Society.

Pulse duration discriminator

International Nuclear Information System (INIS)

Kosakovskij, L.F.

1980-01-01

Basic circuits of a discriminator for discrimination of pulses with the duration greater than the preset one, and of a multifunctional discriminator allowing to discriminate pulses with the duration greater (tsub(p)>tsub(s)) and lesser (tsub(p) tsub(s) and with the duration tsub(p) [ru

Price duration versus trading volume in high-frequency data for selected DAX companies

Directory of Open Access Journals (Sweden)

Christoph Mitterer

2016-12-01

Full Text Available The properties of the time series of durations between consecutive trades of a particular stock have been studied by many contributors in the literature of financial econometrics. Among them are highly prominent scientists like Engle (2000 and Gourieroux and Jasiak (2001. The importance of this topic, accompanied by the growing availability of (ultra-high-frequency data, has prompted an increase of contributions in recent years. Intensive research based on high-frequency data has several financial motivations. First of all, it is linked with microstructure theory. Secondly, it contributes to the literature on stochastic time deformation. But the most important need for research on the dynamics of trade durations is the necessity to manage liquidity risk. The reason is that durations between the following trades are a widely accepted measures of market liquidity. In addition, their volatility reflects the liquidity risk.

Duration of Untreated Cardiac Arrest and Clinical Relevance of Animal Experiments: The Relationship Between the "No-Flow" Duration and the Severity of Post-Cardiac Arrest Syndrome in a Porcine Model.

Science.gov (United States)

Babini, Giovanni; Grassi, Luigi; Russo, Ilaria; Novelli, Deborah; Boccardo, Antonio; Luciani, Anita; Fumagalli, Francesca; Staszewsky, Lidia; Fiordaliso, Fabio; De Maglie, Marcella; Salio, Monica; Zani, Davide D; Letizia, Teresa; Masson, Serge; Luini, Mario V; Pravettoni, Davide; Scanziani, Eugenio; Latini, Roberto; Ristagno, Giuseppe

2018-02-01

The study investigated the effect of untreated cardiac arrest (CA), that is, "no-flow" time, on postresuscitation myocardial and neurological injury, and survival in a pig model to identify an optimal duration that adequately reflects the most frequent clinical scenario. An established model of myocardial infarction followed by CA and cardiopulmonary resuscitation was used. Twenty-two pigs were subjected to three no-flow durations: short (8-10 min), intermediate (12-13 min), and long (14-15 min). Left ventricular ejection fraction (LVEF) was assessed together with thermodilution cardiac output (CO) and high sensitivity cardiac troponin T (hs-cTnT). Neurological impairment was evaluated by neurological scores, serum neuron specific enolase (NSE), and histopathology. More than 60% of animals survived when the duration of CA was ≤13 min, compared to only 20% for a duration ≥14 min. Neuronal degeneration and neurological scores showed a trend toward a worse recovery for longer no-flow durations. No animals achieved a good neurological recovery for a no-flow ≥14 min, in comparison to a 56% for a duration ≤13 min (P = 0.043). Serum NSE levels significantly correlated with the no-flow duration (r = 0.892). Longer durations of CA were characterized by lower LVEF and CO compared to shorter durations (P flow time, the higher was the number of defibrillations delivered (P = 0.043). The defibrillations delivered significantly correlated with LVEF and plasma hs-cTnT. Longer no-flow durations caused greater postresuscitation myocardial and neurological dysfunction and reduced survival. An untreated CA of 12-13 min may be an optimal choice for a clinically relevant model.

The temporal-relevance temporal-uncertainty model of prospective duration judgment.

Science.gov (United States)

Zakay, Dan

2015-12-15

A model aimed at explaining prospective duration judgments in real life settings (as well as in the laboratory) is presented. The model is based on the assumption that situational meaning is continuously being extracted by humans' perceptual and cognitive information processing systems. Time is one of the important dimensions of situational meaning. Based on the situational meaning, a value for Temporal Relevance is set. Temporal Relevance reflects the importance of temporal aspects for enabling adaptive behavior in a specific moment in time. When Temporal Relevance is above a certain threshold a prospective duration judgment process is evoked automatically. In addition, a search for relevant temporal information is taking place and its outcomes determine the level of Temporal Uncertainty which reflects the degree of knowledge one has regarding temporal aspects of the task to be performed. The levels of Temporal Relevance and Temporal Uncertainty determine the amount of attentional resources allocated for timing by the executive system. The merit of the model is in connecting timing processes with the ongoing general information processing stream. The model rests on findings in various domains which indicate that cognitive-relevance and self-relevance are powerful determinants of resource allocation policy. The feasibility of the model is demonstrated by analyzing various temporal phenomena. Suggestions for further empirical validation of the model are presented. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of nuclear track on reflectivity for insulating material

International Nuclear Information System (INIS)

Liu Cunxiong; Ni Bangfa; Tian Weizhi; Hu Lian; Xiao Caijin; Wang Pingsheng; Zhang Guiying; Huang Donghui; Lu Peng; Yang Weitao

2009-01-01

Polyester and CR-39 samples were irradiated with sulphur ion from HI-13 tandem accelerator. Ultraviolet light with wavelength 360 nm was used to sensitize the polymer before chemical etching by NaOH solution with different temperatures and time duration. The latent track was then developed into nanometer to micrometer pore with certain depth. Samples were coated with thin layer of silver and magnesium fluoride using the vacuum evaporator. The reflectivity and transmission index were measured for all polymer samples, untreated and treated with above-mentioned procedure, within the wavelength of visible light. Solid state nuclear track and coating can reduce reflectivity of tested polymer materials greatly, and the reflectivity can be 1% or lower. (authors)

Incidental learning during rapid information processing on the symbol-digit modalities test.

Science.gov (United States)

Denney, Douglas R; Hughes, Abbey J; Elliott, Jacquelyn K; Roth, Alexandra K; Lynch, Sharon G

2015-06-01

The Symbol--Digit Modalities Test (SDMT) is widely used to assess processing speed in MS patients. We developed a computerized version of the SDMT (c-SDMT) that scored participants' performance during subintervals over the course of the usual 90-s time period and also added an incidental learning test (c-ILT) to assess how well participants learned the symbol-digit associations while completing the c-SDMT. Patients with MS (n = 65) achieved lower scores than healthy controls (n = 38) on both the c-SDMT and c-ILT, and the scores on the two tests were correlated. However, no increase in the rate of item completion occurred for either group over the course of the c-SDMT, and the difference between groups was the same during each subinterval. Therefore, it seems implausible that controls completed more items on the c-SDMT because they were more adept at learning the symbol-digit associations as the test ensued. Instead, MS patients' poorer incidental learning performance appears to reflect the greater attentional burden that tasks requiring rapid serial processing of information impose upon them. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Discounted Duration Calculus

DEFF Research Database (Denmark)

Ody, Heinrich; Fränzle, Martin; Hansen, Michael Reichhardt

2016-01-01

To formally reason about the temporal quality of systems discounting was introduced to CTL and LTL. However, these logic are discrete and they cannot express duration properties. In this work we introduce discounting for a variant of Duration Calculus. We prove decidability of model checking...... for a useful fragment of discounted Duration Calculus formulas on timed automata under mild assumptions. Further, we provide an extensive example to show the usefulness of the fragment....

Longer duration of obesity is associated with a reduction in urinary angiotensinogen in prepubertal children.

Science.gov (United States)

Morato, Manuela; Correia-Costa, Liane; Sousa, Teresa; Cosme, Dina; Schaefer, Franz; Areias, José Carlos; Guerra, António; Afonso, Alberto Caldas; Barros, Henrique; Azevedo, Ana; Albino-Teixeira, António

2017-08-01

We aimed to study the impact of obesity on urinary excretion of angiotensinogen (U-AGT) in prepubertal children, focusing on the duration of obesity and gender. Also, we aimed to evaluate whether plasma angiotensinogen (P-AGT) and hydrogen peroxide (H 2 O 2 ) play a role in the putative association. Cross-sectional evaluation of 305 children aged 8-9 years (160 normal weight, 86 overweight, and 59 obese). Anthropometric measurements and 24-h ambulatory blood pressure monitoring were performed. Angiotensinogen (AGT) was determined by a commercial enzyme-linked immunosorbent assay (ELISA) kit and H 2 O 2 by a microplate fluorometric assay. U-AGT and P-AGT levels were similar across body mass index (BMI) groups and between sexes. However, boys who were overweight/obese since the age of 4 years presented lower levels of U-AGT compared with those of normal weight at the same age. In children who were overweight/obese since the age of 4, urinary H 2 O 2 decreased with P-AGT. A higher duration of obesity was associated with decreased U-AGT in boys, thus reflecting decreased intrarenal activity of the renin-angiotensin system. Also, children with a longer duration of obesity showed an inverse association between urinary H 2 O 2 and P-AGT. Future studies should address whether these results reflect an early compensatory mechanism to limit obesity-triggered renal dysfunction.

Self-reflection of extremely short light pulses in nonlinear optical waveguides

Science.gov (United States)

Kurasov, Alexander E.; Kozlov, Sergei A.

2004-07-01

An equation describing the generation of reflected radiation during the propagation of high-intensity extremely short pulses in a nonlinear optical waveguide is derived. The phenomena taking place during the strong self-inducted changes of the temporal structure of the forward wave are studied. It is shown that the duration of the backward pulse is much greater than the duration of the forward pulse and that the main part of the energy of the backward wave is carried by lower frequencies than the central frequency of the forward wave.

Measurements of the dependence of damage thresholds on laser wavelength, pulse duration and film thickness

International Nuclear Information System (INIS)

Rainer, F.; Vercimak, C.L.; Carniglia, C.K.; Milam, D.; Hart, T.T.

1985-01-01

Results of three experiments are described. The authors used 351-nm and 355-nm pulses with durations of 0.6, 1, 5 and 9 ns to measure thresholds for a variety of antireflectance and high reflectance coatings. The functional form t/sup m/, with t the pulse duration, was used to scale fluence thresholds measured at 0.6 ns to those measured at 9.0 ns. Values of the coefficient m ranged from 0.10 to 0.51. The average value was 0.30. In the second experiment, they measured thresholds at 1064 nm, 527 nm and 355 nm for single-frequency high reflectance ZrO/sub 2//SiO/sub 2/ coatings. Coatings for all three frequencies were deposited simultaneously by use of masks in the coating chamber. Thresholds varied from 2-4 J/cm/sup 2/ at 355 nm to 7-10 J/cm/sup 2/ at 1064 nm. The third experiment measured thresholds at 355 nm for antireflection coatings made with layer thicknesses varying from greater than one wavelength to less than a quarterwavelength. A significant variation of threshold with coating thickness was not observed, but the median thresholds increased slightly as coating thickness increased

Effect of reflective surfaces on a greenhouse lettuce crop

Energy Technology Data Exchange (ETDEWEB)

Warman, P.R.; Mayhew, W.J.

1979-01-01

The Canadian greenhouse industry is an important segment of horticultural production, providing employment for thousands of people. Continuing increases in the costs of conventional fuel supplies, however, has placed the industry in some jeopardy since the cost of heating during the winter months is also escalating. In response to this problem the Brace Research Institute has developed a single roofed greenhouse designed to capture and store the sun's energy, and to increase the amount of downward solar radiation inside the greenhouse through the use of specularly-reflecting back and side walls. The research investigated the effect of a reflective surface on plant growth, development, and nutritional uptake during fall and the early months of winter. The inside walls of the greenhouse were lined with aluminized polyester to act as a reflective surface and flat black roofing felt paper to provide a non-reflecting surface. Grand Rapids Forcing lettuce was planted from seed into a peat-vermiculite bed and total solar radiation was monitored on the horizontal. Over the duration of the experiment, the reflective side of the greenhouse received more than twice as much solar radiation as the non-reflective side leading to significantly larger plant yields on the reflective side. There were no significant differences in the uptake of the plant macronutrients, N, P, K, Ca, and Mg.

On the X-ray reflectivity by poly allyl diglycol carbonate (PADC)

International Nuclear Information System (INIS)

Ghazaly, M. El

2011-01-01

X-ray reflectivity via the poly allyl diglycol carbonate (CR-39 polymer sheet) was investigated. X-ray reflectivity was measured for a pristine and a chemically etched CR-39 detector in 6.25N NaOH at (70 ± 0.5) .deg. C for different durations. Far from the spectral peak, the reflectivity of the CR-39 polymer sheet has a wide peak at 2θ = 20.1 .deg. , and its intensity is decreased by increasing the etching time. Moreover, the integrated counts under the peaks, C(t e ), vary linearly as a function of the etching time t e . Data are fitted using a linear function C(t e ) = A+Bt e , with fitting parameters A = (3271 ± 170) and B = (- 960 ± 84). The reflectivity deterioration is attributed to the increase of CR-39 surface's roughness due to the chemical etching. The rocking curves of X-ray reflectivity were measured for a pristine and an etched CR-39 polymer sheet. Specular reflections are observed, as well as Yoneda wings, which broaden and move away from the specular reflections due to the increase in the CR-39 surface's roughness.

FTIR spectroscopy and reflectance of modern charcoals and fungal decayed woods: implications for studies of inertinite in coals

Energy Technology Data Exchange (ETDEWEB)

Guo, Y.; Bustin, R.M. [University of British Columbia, Vancouver, BC (Canada). Dept. of Earth and Ocean Sciences

1998-09-01

The chemical and physical characteristics of laboratory produced charcoals, natural charcoals, fungal decayed woods and inertinite from a variety of Western Canadian coals were investigated using FTIR and standard petrologic techniques. The studies confirm and extend earlier work in showing that almost all inertinite macerals can be attributed to wildfire in peat swamps, and that variation in the petrological characteristics of inertinite are a product of temperature, duration of heating and the nature of the initial plant material. The relationships between reflectance and temperature, as well as heating duration of charcoal formation are established as a reference for the examination of inertinite, and the probable temperature of inertinite precursor (fossil charcoal) formation in paleo-widlfire. Fungi do not directly contribute to the formation of charcoal and inertinite apart from the fungal bodies themselves (funginite: sclerotia and hyphae) and perhaps by increasing the extent of shrinkage and cracking (increasing surface area) of the plant materials and thus susceptibility to charring. Evidence of fungal activity progressively decreases with increasing degree of charing in response to duration of heating or increased charing temperature. The reflectance values and FTIR spectral characteristics of inertinites in Western Canadian coal suggest that most inertinite formed by wildfires at temperatures over 400{degree}C. The great abundance of semifusinite in Western Canadian coal may reflect frequent but short duration wildfires in precursor peat swamps. 44 refs., 16 figs., 6 tabs.

A piecewise modeling approach for climate sensitivity studies: Tests with a shallow-water model

Science.gov (United States)

Shao, Aimei; Qiu, Chongjian; Niu, Guo-Yue

2015-10-01

In model-based climate sensitivity studies, model errors may grow during continuous long-term integrations in both the "reference" and "perturbed" states and hence the climate sensitivity (defined as the difference between the two states). To reduce the errors, we propose a piecewise modeling approach that splits the continuous long-term simulation into subintervals of sequential short-term simulations, and updates the modeled states through re-initialization at the end of each subinterval. In the re-initialization processes, this approach updates the reference state with analysis data and updates the perturbed states with the sum of analysis data and the difference between the perturbed and the reference states, thereby improving the credibility of the modeled climate sensitivity. We conducted a series of experiments with a shallow-water model to evaluate the advantages of the piecewise approach over the conventional continuous modeling approach. We then investigated the impacts of analysis data error and subinterval length used in the piecewise approach on the simulations of the reference and perturbed states as well as the resulting climate sensitivity. The experiments show that the piecewise approach reduces the errors produced by the conventional continuous modeling approach, more effectively when the analysis data error becomes smaller and the subinterval length is shorter. In addition, we employed a nudging assimilation technique to solve possible spin-up problems caused by re-initializations by using analysis data that contain inconsistent errors between mass and velocity. The nudging technique can effectively diminish the spin-up problem, resulting in a higher modeling skill.

Perception of social interaction compresses subjective duration in an oxytocin-dependent manner.

Science.gov (United States)

Liu, Rui; Yuan, Xiangyong; Chen, Kepu; Jiang, Yi; Zhou, Wen

2018-05-22

Communication through body gestures permeates our daily life. Efficient perception of the message therein reflects one's social cognitive competency. Here we report that such competency is manifested temporally as shortened subjective duration of social interactions: motion sequences showing agents acting communicatively are perceived to be significantly shorter in duration as compared with those acting noncommunicatively. The strength of this effect is negatively correlated with one's autistic-like tendency. Critically, intranasal oxytocin administration restores the temporal compression effect in socially less proficient individuals, whereas the administration of atosiban, a competitive antagonist of oxytocin, diminishes the effect in socially proficient individuals. These findings indicate that perceived time, rather than being a faithful representation of physical time, is highly idiosyncratic and ingrained with one's personality trait. Moreover, they suggest that oxytocin is involved in mediating time perception of social interaction, further supporting the role of oxytocin in human social cognition. © 2018, Liu et al.

Word Durations in Non-Native English

Science.gov (United States)

Baker, Rachel E.; Baese-Berk, Melissa; Bonnasse-Gahot, Laurent; Kim, Midam; Van Engen, Kristin J.; Bradlow, Ann R.

2010-01-01

In this study, we compare the effects of English lexical features on word duration for native and non-native English speakers and for non-native speakers with different L1s and a range of L2 experience. We also examine whether non-native word durations lead to judgments of a stronger foreign accent. We measured word durations in English paragraphs read by 12 American English (AE), 20 Korean, and 20 Chinese speakers. We also had AE listeners rate the `accentedness' of these non-native speakers. AE speech had shorter durations, greater within-speaker word duration variance, greater reduction of function words, and less between-speaker variance than non-native speech. However, both AE and non-native speakers showed sensitivity to lexical predictability by reducing second mentions and high frequency words. Non-native speakers with more native-like word durations, greater within-speaker word duration variance, and greater function word reduction were perceived as less accented. Overall, these findings identify word duration as an important and complex feature of foreign-accented English. PMID:21516172

The effect of building facade reflectivity on urban dwellers in tropics.

Science.gov (United States)

Ishak, N. M.; Hien, W. N.; Jenatabadi, H. S.; Ignatius, M.; Yaman, R.

2018-02-01

With the rapid growth and use of modern architecture practices for high-rise buildings, highly reflective materials have been adopted extensively for aesthetical reasons. However, outdoor glare from highly reflective facades might cause thermal and visual problems towards the occupants of neighbouring buildings and outdoor dwellers, particularly pedestrians. In tropical countries, this negative impact can be greater due to the higher solar radiation received throughout the year. At the present, there are few building guidelines limiting outdoor glare, or daylight reflectance from a building facade. This study aims to introduce a framework for outdoor glare studies that focus on perceived glare from highly reflective facades by pedestrians in Singapore. The introduced framework includes age, glare time, glare duration, avoidance and sensitiveness. For this study, the survey is carried out with the application of Structural Equation Modelling (SEM). This paper is helpful for planners, designers, and engineers to estimate the sensitivity of pedestrians’ discomfort glare and towards the creation of sustainable architecture in Singapore.

Ultra-low reflection porous silicon nanowires for solar cell applications

KAUST Repository

Najar, Adel

2012-01-01

High density vertically aligned Porous Silicon NanoWires (PSiNWs) were fabricated on silicon substrate using metal assisted chemical etching process. A linear dependency of nanowire length to the etching time was obtained and the change in the growth rate of PSiNWs by increasing etching durations was shown. A typical 2D bright-field TEM image used for volume reconstruction of the sample shows the pores size varying from 10 to 50 nm. Furthermore, reflectivity measurements show that the 35% reflectivity of the starting silicon wafer drops to 0.1% recorded for more than 10 μm long PSiNWs. Models based on cone shape of nanowires located in a circular and rectangular bases were used to calculate the reflectance employing the Transfert Matrix Formalism (TMF) of the PSiNWs layer. Using TMF, the Bruggeman model was used to calculate the refractive index of PSiNWs layer. The calculated reflectance using circular cone shape fits better the measured reflectance for PSiNWs. The remarkable decrease in optical reflectivity indicates that PSiNWs is a good antireflective layer and have a great potential to be utilized in radial or coaxial p-n heterojunction solar cells that could provide orthogonal photon absorption and enhanced carrier collection. ©2012 Optical Society of America.

An investigation into the strength of the association and agreement levels between subjective and objective sleep duration in adolescents.

Directory of Open Access Journals (Sweden)

Teresa Arora

Full Text Available The majority of adolescent sleep research has utilized self-reported sleep duration and some have based information on a solitary question. Whilst some have claimed to have validated sleep survey data with objective actigraphy measures in adolescents, the statistical approach applied only demonstrates the strength of the association between subjective and objective sleep duration data and does not reflect if these different methods actually agree.Data were collected as part of the Midlands Adolescents Schools Sleep Education Study (MASSES. Adolescents (n=225 aged 11-13 years provided estimates for weekday, weekend and combined sleep duration based on self-reported survey data, a 7-day sleep diary, and wrist-worn actigraphy.We assessed the strength of the relationship as well as agreement levels between subjective and objectively determined sleep duration (weekday, weekend and combined. Subjective diary sleep duration was significantly correlated with actigraphy estimates for weekday and weekend sleep duration r=0.30, p ≤ 0.001 and r=0.31, p ≤ 0.001 respectively. Pitman's test demonstrated no significant difference in the variance between weekend sleep duration (r=0.09, p=0.16 and combined sleep duration (r=0.12, p=0.08 indicating acceptable agreement between actigraphy and sleep diary sleep duration only. Self-reported sleep duration estimates (weekday, weekend and combined did not agree with actigraphy determined sleep duration.Sleep diaries are a cost-effective alternative to survey/questionnaire data. Self-reported measures of sleep duration in adolescents do not agree with actigraphy measures and should be avoided where possible. Previous adolescent sleep studies that have utilized self-reported survey data may not provide a complete representation of sleep on the outcome measure of interest.

Reflecting reflection in supervision

DEFF Research Database (Denmark)

Lystbæk, Christian Tang

associated with reflection and an exploration of alternative conceptions that view reflection within the context of settings which have a more group- and team-based orientation. Drawing on an action research project on health care supervision, the paper questions whether we should reject earlier views...... of reflection, rehabilitate them in order to capture broader connotations or move to new ways of regarding reflection that are more in keeping with not only reflective but also emotive, normative and formative views on supervision. The paper presents a critical perspective on supervision that challenge...... the current reflective paradigm I supervision and relate this to emotive, normative and formative views supervision. The paper is relevant for Nordic educational research into the supervision and guidance...

Speaker-specific variability of phoneme durations

CSIR Research Space (South Africa)

Van Heerden, CJ

2007-11-01

Full Text Available The durations of phonemes varies for different speakers. To this end, the correlations between phonemes across different speakers are studied and a novel approach to predict unknown phoneme durations from the values of known phoneme durations for a...

Synthesizing controllers from duration calculus

DEFF Research Database (Denmark)

Fränzle, Martin

1996-01-01

Duration Calculus is a logic for reasoning about requirements for real-time systems at a high level of abstraction from operational detail, which qualifies it as an interesting starting point for embedded controller design. Such a design activity is generally thought to aim at a control device...... the physical behaviours of which satisfy the requirements formula, i.e. the refinement relation between requirements and implementations is taken to be trajectory inclusion. Due to the abstractness of the vocabulary of Duration Calculus, trajectory inclusion between control requirements and controller designs...... for embedded controller design and exploit this fact for developing an automatic procedure for controller synthesis from specifications formalized in Duration Calculus. As far as we know, this is the first positive result concerning feasibility of automatic synthesis from dense-time Duration Calculus....

Model-checking dense-time Duration Calculus

DEFF Research Database (Denmark)

Fränzle, Martin

2004-01-01

Since the seminal work of Zhou Chaochen, M. R. Hansen, and P. Sestoft on decidability of dense-time Duration Calculus [Zhou, Hansen, Sestoft, 1993] it is well-known that decidable fragments of Duration Calculus can only be obtained through withdrawal of much of the interesting vocabulary...... of this logic. While this was formerly taken as an indication that key-press verification of implementations with respect to elaborate Duration Calculus specifications were also impossible, we show that the model property is well decidable for realistic designs which feature natural constraints...... suitably sparser model classes we obtain model-checking procedures for rich subsets of Duration Calculus. Together with undecidability results also obtained, this sheds light upon the exact borderline between decidability and undecidability of Duration Calculi and related logics....

Duration of inhibition of ventral tegmental area dopamine neurons encodes a level of conditioned fear.

Science.gov (United States)

Mileykovskiy, Boris; Morales, Marisela

2011-05-18

It is widely accepted that midbrain dopamine (DA) neurons encode actual and expected reward values by phasic alterations in firing rate. However, how DA neurons encode negative events in the environment is still unclear because some DA neurons appear to be depressed and others excited by aversive stimuli. Here, we show that exposing fear-conditioned rats to stimuli predicting electrical shock elicited three types of biphasic responses, each of which contained an inhibitory pause, in neurochemically identified ventral tegmental area (VTA) DA neurons. The duration of the inhibitory pause in these responses of VTA DA neurons was in direct proportion to the increase in respiratory rate reflecting the level of conditioned fear. Our results suggest that the duration of inhibition of VTA DA neurons encodes negative emotional values of signals predicting aversive events in the environment.

Similarity analysis of spectra obtained via reflectance spectrometry in legal medicine.

Science.gov (United States)

Belenki, Liudmila; Sterzik, Vera; Bohnert, Michael

2014-02-01

In the present study, a series of reflectance spectra of postmortem lividity, pallor, and putrefaction-affected skin for 195 investigated cases in the course of cooling down the corpse has been collected. The reflectance spectrometric measurements were stored together with their respective metadata in a MySQL database. The latter has been managed via a scientific information repository. We propose similarity measures and a criterion of similarity that capture similar spectra recorded at corpse skin. We systematically clustered reflectance spectra from the database as well as their metadata, such as case number, age, sex, skin temperature, duration of cooling, and postmortem time, with respect to the given criterion of similarity. Altogether, more than 500 reflectance spectra have been pairwisely compared. The measures that have been used to compare a pair of reflectance curve samples include the Euclidean distance between curves and the Euclidean distance between derivatives of the functions represented by the reflectance curves at the same wavelengths in the spectral range of visible light between 380 and 750 nm. For each case, using the recorded reflectance curves and the similarity criterion, the postmortem time interval during which a characteristic change in the shape of reflectance spectrum takes place is estimated. The latter is carried out via a software package composed of Java, Python, and MatLab scripts that query the MySQL database. We show that in legal medicine, matching and clustering of reflectance curves obtained by means of reflectance spectrometry with respect to a given criterion of similarity can be used to estimate the postmortem interval.

Determinants of long-duration commuting and long-duration commuters' perceptions and attitudes toward commuting time: Evidence from Kunming, China

Directory of Open Access Journals (Sweden)

Mingwei He

2017-04-01

Full Text Available Understanding the commuting patterns of long-duration commuters and the possible changes in these patterns can help policymakers adopt the more reasonable land use and transportation policies. With Kunming in China as a case study, the determinants of long-duration commuting trips were identified based on logistic regression model. The results indicated that age, education level, number of workers, presence of retirees, and residential location have a significant impact on the occurrence of long-duration commuting trips. The ideal commuting times and tolerance thresholds of commuting time of long-duration commuters were also investigated. The statistical results revealed the distributions of ideal commuting times and tolerance thresholds of commuting time of both short- and long-duration commuters. The average tolerance threshold of commuting time and the average ideal commuting time of long-duration commuters were greater than those of short-duration commuters. For 97.2% of the long-duration commuters, their actual commuting time was longer than the ideal commuting time; this finding indicates that most long-duration commuters are dissatisfied with their commuting time. The actual commuting time of 40.1% long-duration commuters exceeded their tolerance thresholds; these commuters are eager to reduce their commuting time.

Resting-state connectivity of the sustained attention network correlates with disease duration in idiopathic generalized epilepsy.

Directory of Open Access Journals (Sweden)

Mona Maneshi

Full Text Available INTRODUCTION: In idiopathic generalized epilepsy (IGE, a normal electroencephalogram between generalized spike and wave (GSW discharges is believed to reflect normal brain function. However, some studies indicate that even excluding GSW-related errors, IGE patients perform poorly on sustained attention task, the deficit being worse as a function of disease duration. We hypothesized that at least in a subset of structures which are normally involved in sustained attention, resting-state functional connectivity (FC is different in IGE patients compared to controls and that some of the changes are related to disease duration. METHOD: Seeds were selected based on a sustained attention study in controls. Resting-state functional magnetic resonance imaging (fMRI data was obtained from 14 IGE patients and 14 matched controls. After physiological noise removal, the mean time-series of each seed was used as a regressor in a general linear model to detect regions that showed correlation with the seed. In patients, duration factor was defined based on epilepsy duration. Between-group differences weighted by the duration factor were evaluated with mixed-effects model. Correlation was then evaluated in IGE patients between the FC, averaged over each significant cluster, and the duration factor. RESULTS: Eight of 18 seeds showed significant difference in FC across groups. However, only for seeds in the medial superior frontal and precentral gyri and in the medial prefrontal area, average FC taken over significant clusters showed high correlation with the duration factor. These 3 seeds showed changes in FC respectively with the premotor and superior frontal gyrus, the dorsal premotor, and the supplementary motor area plus precentral gyrus. CONCLUSION: Alterations of FC in IGE patients are not limited to the frontal areas. However, as indicated by specificity analysis, patients with long history of disease show changes in FC mainly within the frontal areas.

Duration of orthognathic-surgical treatment.

Science.gov (United States)

Paunonen, Jaakko; Helminen, Mika; Peltomäki, Timo

2017-07-01

The objective of this study was to determine the duration of orthognathic-surgical treatment conducted with conventional pre- and post-surgical orthodontic treatment phases. The study material was comprised of the files of 185 consecutive patients treated in Oral and Maxillofacial Unit, Tampere University Hospital, Finland, in 2007-2014. The files were reviewed and the following data was obtained: gender and age of patients, ICD-10 diagnosis, type of malocclusion, duration of pre- and post-surgical orthodontic treatment and type of operation. Total treatment duration (median) from placement of separating rings for banding until fixed orthodontic appliances were removed and retention period started was 31.1 months, of which pre-surgical orthodontics took 24.4 months and postsurgical 6.4 months. Treatment duration (median) was in BSSO was 32.1, LeFort 1 30.1 and bimaxillary osteotomy 29.7 months. Orthodontic extractions were performed in 35 patients (19%). If the orthodontic treatment included tooth extraction, the duration of pre-surgical treatment was on average 10 months longer, which is a statistically highly significant difference (p pre-surgical orthodontic treatment prolong treatment time by an average of 8-9 months.

The effective reflection of a pulse sequence from a four-wave mirror with thermal nonlinearity under parametric feedback

Science.gov (United States)

Barashkov, M. S.; Bel'Diugin, I. M.; Zolotarev, M. V.; Kruzhilin, Iu. I.; Krymskii, M. I.

1989-04-01

A four-wave mirror with thermal nonlinearity has been experimentally realized with the interaction of corunning waves under parametric feedback with a nonreciprocal element. The effective reflection of a sequence of pulses with duration of about 300 ns from a neodymium-glass laser with maximal reflection coefficients greater than 30 has been demonstrated. The quality of the radiation reflected from the mirror is studied. A significant reduction in the steady-state lasing threshold has been shown with thermal nonlinearity at small angles of the interacting beam convergence, compared to the case of counterrunning convergence.

From Sleep Duration to Childhood Obesity

DEFF Research Database (Denmark)

Börnhorst, Claudia; Hense, Sabrina; Ahrens, Wolfgang

2012-01-01

Sleep duration has been identified as risk factor for obesity already in children. Besides investigating the role of fat mass (FM), this study addressed the question whether endocrine mechanisms act as intermediates in the association between sleep duration and overweight/obesity. Within...... the framework of the IDEFICS study, the present research was conducted in 609 German resident children aged 2–9 years with information on fasting insulin, C-reactive protein and cortisol levels next to anthropometric measurements and parental questionnaires. Emphasising methodological aspects, an age......-specific measure of sleep duration was derived to account for alteration in sleep duration during childhood/period of growth. Multivariate linear regression and quantile regression models confirmed an inverse relationship between sleep duration and measures of overweight/obesity. The estimate for the association...

Ultra-low reflection porous silicon nanowires for solar cell applications

OpenAIRE

Najar , Adel; Charrier , Joël; Pirasteh , Parastesh; Sougrat , R.

2012-01-01

International audience; High density vertically aligned Porous Silicon NanoWires (PSiNWs) were fabricated on silicon substrate using metal assisted chemical etching process. A linear dependency of nanowire length to the etching time was obtained and the change in the growth rate of PSiNWs by increasing etching durations was shown. A typical 2D bright-field TEM image used for volume reconstruction of the sample shows the pores size varying from 10 to 50 nm. Furthermore, reflectivity measuremen...

Effects of spectral complexity and sound duration on automatic complex-sound pitch processing in humans - a mismatch negativity study.

Science.gov (United States)

Tervaniemi, M; Schröger, E; Saher, M; Näätänen, R

2000-08-18

The pitch of a spectrally rich sound is known to be more easily perceived than that of a sinusoidal tone. The present study compared the importance of spectral complexity and sound duration in facilitated pitch discrimination. The mismatch negativity (MMN), which reflects automatic neural discrimination, was recorded to a 2. 5% pitch change in pure tones with only one sinusoidal frequency component (500 Hz) and in spectrally rich tones with three (500-1500 Hz) and five (500-2500 Hz) harmonic partials. During the recordings, subjects concentrated on watching a silent movie. In separate blocks, stimuli were of 100 and 250 ms in duration. The MMN amplitude was enhanced with both spectrally rich sounds when compared with pure tones. The prolonged sound duration did not significantly enhance the MMN. This suggests that increased spectral rather than temporal information facilitates pitch processing of spectrally rich sounds.

Incorporating Duration Information in Activity Recognition

Science.gov (United States)

Chaurasia, Priyanka; Scotney, Bryan; McClean, Sally; Zhang, Shuai; Nugent, Chris

Activity recognition has become a key issue in smart home environments. The problem involves learning high level activities from low level sensor data. Activity recognition can depend on several variables; one such variable is duration of engagement with sensorised items or duration of intervals between sensor activations that can provide useful information about personal behaviour. In this paper a probabilistic learning algorithm is proposed that incorporates episode, time and duration information to determine inhabitant identity and the activity being undertaken from low level sensor data. Our results verify that incorporating duration information consistently improves the accuracy.

Duration of surgical-orthodontic treatment.

Science.gov (United States)

Häll, Birgitta; Jämsä, Tapio; Soukka, Tero; Peltomäki, Timo

2008-10-01

To study the duration of surgical-orthodontic treatment with special reference to patients' age and the type of tooth movements, i.e. extraction vs. non-extraction and intrusion before or extrusion after surgery to level the curve of Spee. The material consisted files of 37 consecutive surgical-orthodontic patients. The files were reviewed and gender, diagnosis, type of malocclusion, age at the initiation of treatment, duration of treatment, type of tooth movements (extraction vs. non-extraction and levelling of the curve of Spee before or after operation) and type of operation were retrieved. For statistical analyses two sample t-test, Kruskal-Wallis and Spearman rank correlation tests were used. Mean treatment duration of the sample was 26.8 months, of which pre-surgical orthodontics took on average 17.5 months. Patients with extractions as part of the treatment had statistically and clinically significantly longer treatment duration, on average 8 months, than those without extractions. No other studied variable seemed to have an impact on the treatment time. The present small sample size prevents reliable conclusions to be made. However, the findings suggest, and patients should be informed, that extractions included in the treatment plan increase chances of longer duration of surgical-orthodontic treatment.

The periodicity of sleep duration – an infradian rhythm in spontaneous living

Directory of Open Access Journals (Sweden)

Wong SN

2013-01-01

Full Text Available Shi Ngar Wong, Mark Halaki, Chin Moi ChowDiscipline of Exercise and Sport Science, University of Sydney, Sydney, NSW, AustraliaAbstract: The sleep–wake cycle is a process not only dictated by homeostatic and circadian factors but also by social and environmental influences. Thus, the total sleep time partly reflects sleep need, which is integral to the dynamics of sleep loss recovery. This study explored the nature of the observed oscillations in total sleep time in healthy adults under spontaneous living conditions. Actigraph-measured sleep data for 13 healthy young male adults were collected over 14 consecutive days and analyzed for habitual sleep duration. The total sleep time periodicity was modeled using the cosinor method for each individual across the 14 days. The findings confirm the existence of periodicity in habitual sleep duration as there were clear periodic patterns in the majority of the participants. Although exclusive to each individual, the observed oscillations may be a resultant response of homeostatic sleep need, circadian timing, and/or social and environmental influences. These findings instigate further indepth studies into the periodicity of sleep duration in healthy individuals to provide a better understanding of sleep need in short versus long sleepers, in predicting work performance, and reducing sleepiness-related accidents following shift work, and how this periodicity may impact sleep treatment outcome in clinical populations.Keywords: sleep regulation, homeostasis, habitual sleep, spontaneous living, healthy males

[Individual variability in the duration of the second phase of the mixed dentition].

Science.gov (United States)

Löhr, E

1994-02-01

With a collection of dental casts from a longitudinal study of 175 orthodontically untreated probands (100 children without and 75 children with premature loss of deciduous molars and/or canines) serving as a base, the duration of the second period of mixed dentition was determined to be in relation to the probands the period of time between the gingival emergence of the first permanent buccal tooth and the full eruption of the set of teeth. The second period of mixed dentition in boys without premature loss of deciduous molars and canines lasts on an average 3.6 +/- 1.1 years and in girls 3.8 +/- 1.0 years. In cases of premature loss of deciduous molars and/or canines, the period of dentition is distinctly longer than under normal development conditions. The outside parameters (boys: Xmin = 0.9 years, Xmax = 6.2 years; girls: Xmin = 2.6 years, Xmax = 8.6 years), reflect a high degree of variability. The duration of the second period of mixed dentition is significantly affected by "the point in time of inception" and by the criteria "morphologically intact support zones" and "premature loss of deciduous molars and/or canines". Even given such data, however, it is not possible to make a sufficiently reliable prediction on an individual basis of the duration of the dentition.

The effect of predictability on subjective duration.

Directory of Open Access Journals (Sweden)

Vani Pariyadath

2007-11-01

Full Text Available Events can sometimes appear longer or shorter in duration than other events of equal length. For example, in a repeated presentation of auditory or visual stimuli, an unexpected object of equivalent duration appears to last longer. Illusions of duration distortion beg an important question of time representation: when durations dilate or contract, does time in general slow down or speed up during that moment? In other words, what entailments do duration distortions have with respect to other timing judgments? We here show that when a sound or visual flicker is presented in conjunction with an unexpected visual stimulus, neither the pitch of the sound nor the frequency of the flicker is affected by the apparent duration dilation. This demonstrates that subjective time in general is not slowed; instead, duration judgments can be manipulated with no concurrent impact on other temporal judgments. Like spatial vision, time perception appears to be underpinned by a collaboration of separate neural mechanisms that usually work in concert but are separable. We further show that the duration dilation of an unexpected stimulus is not enhanced by increasing its saliency, suggesting that the effect is more closely related to prediction violation than enhanced attention. Finally, duration distortions induced by violations of progressive number sequences implicate the involvement of high-level predictability, suggesting the involvement of areas higher than primary visual cortex. We suggest that duration distortions can be understood in terms of repetition suppression, in which neural responses to repeated stimuli are diminished.

Dependence of Optical Properties of SEL-Deposited Silver Gallium Selenide Thin Films on the On-Line Growth Parameter: Annealing Duration

International Nuclear Information System (INIS)

Bhuiyan, M.R.A.; Firoz Hasan, S.M.

2005-01-01

Silver gallium selenide (AGS) composite thin films were formed onto ultrasonically and chemically cleaned glass substrates by successive on-line thermal evaporation of individual elements and post-deposition annealing at 300 0 C for various durations in vacuum. The annealing duration was varied between 5 and 20 minutes. The structural and optical properties of the films were ascertained by x-ray diffraction (XRD) and uv-vis-nir spectrophotometry (photon wavelength ranging between 300 and 2500 nm), respectively. The diffractogram indicated that these films were polycrystalline in nature having tetragonal structure with lattice parameters, a ∼ 6.0034 A and c ∼ 10.9165 A. The optical transmittance and reflectance were utilized to compute the absorption coefficient, refractive index and energy gap of the films. Dependence of the optical and structural properties of the films on various annealing durations has been analyzed. The nature of the optical transitions has been direct allowed with band gap energies ranging between 1.713 and 1.757 eV and refractive indices between 1.596 and 3.351 depending on photon energy as well as annealing duration. (authors)

Comparison between intensity- duration thresholds and cumulative rainfall thresholds for the forecasting of landslide

Science.gov (United States)

Lagomarsino, Daniela; Rosi, Ascanio; Rossi, Guglielmo; Segoni, Samuele; Catani, Filippo

2014-05-01

This work makes a quantitative comparison between the results of landslide forecasting obtained using two different rainfall threshold models, one using intensity-duration thresholds and the other based on cumulative rainfall thresholds in an area of northern Tuscany of 116 km2. The first methodology identifies rainfall intensity-duration thresholds by means a software called MaCumBA (Massive CUMulative Brisk Analyzer) that analyzes rain-gauge records, extracts the intensities (I) and durations (D) of the rainstorms associated with the initiation of landslides, plots these values on a diagram, and identifies thresholds that define the lower bounds of the I-D values. A back analysis using data from past events can be used to identify the threshold conditions associated with the least amount of false alarms. The second method (SIGMA) is based on the hypothesis that anomalous or extreme values of rainfall are responsible for landslide triggering: the statistical distribution of the rainfall series is analyzed, and multiples of the standard deviation (σ) are used as thresholds to discriminate between ordinary and extraordinary rainfall events. The name of the model, SIGMA, reflects the central role of the standard deviations in the proposed methodology. The definition of intensity-duration rainfall thresholds requires the combined use of rainfall measurements and an inventory of dated landslides, whereas SIGMA model can be implemented using only rainfall data. These two methodologies were applied in an area of 116 km2 where a database of 1200 landslides was available for the period 2000-2012. The results obtained are compared and discussed. Although several examples of visual comparisons between different intensity-duration rainfall thresholds are reported in the international literature, a quantitative comparison between thresholds obtained in the same area using different techniques and approaches is a relatively undebated research topic.

In situ reflectivity investigations of solid/liquid interface during laser backside etching

International Nuclear Information System (INIS)

Boehme, R.; Otto, T.; Zimmer, K.

2006-01-01

In situ reflectivity measurements of the solid/liquid interface with a pump-probe setup were performed during laser-induced backside wet etching (LIBWE) of fused silica with KrF excimer laser using toluene as absorbing liquid. The intensity, the temporal shape, and the duration of the reflected light measured in dependence on the laser fluence are discussed referring to the surface modification and the bubble formation. The vaporisation of the superheated liquid at the solid interface causes a considerable increase of the reflectivity and gives information about the bubble lifetime. The alterations of the reflectivity after bubbles collapse can be explained with the changed optical properties due to surface modifications of the solid surface. Comparative studies of the reflectivity at different times and the etch rate behaviour in dependence on the laser fluence show that the in situ measured surface modification begins just at the etch threshold fluence and correlates further with etch rate behaviour and the etched surface appearance. The already observed surface modification at LIBWE due to a carbon deposition and structural changes of the near surface region are approved by the changes of the interface reflectivity and emphasizes the importance of the modified surface region in the laser-induced backside wet etching process

Effect of maceration duration on physicochemical characteristics, organic acid, phenolic compounds and antioxidant activity of red wine from Vitis vinifera L. Karaoglan.

Science.gov (United States)

Kocabey, N; Yilmaztekin, M; Hayaloglu, A A

2016-09-01

Effects of different maceration times (5, 10 and 15 days) on composition, phenolic compounds and antioxidant activities of red wines made from the Vitis vinifera L. Karaoglan grown in Malatya were investigated. Maceration duration changed some chemical constituents and color of Karaoglan red wines. A linear relationship was observed between antioxidant activity of wine and maceration duration. Major organic acid was tartaric acid which was at the highest concentration in wine macerated for 10 days. A total of 25 phenolic compounds was determined in wine samples. Within these phenolics; procyanidin B2, trans -caftaric acid, gallic acid, trans -caffeic acid, (+) catechin, (-) epicatechin and quercetin-3- O -glucoside were the most abundant phenolics regardless of maceration duration. In general, extended maceration duration resulted in increase in the concentration of phenolic compounds, reflecting the antioxidant activities of wine. In conclusion, the highest concentrations of total and individual phenolic compounds as well as antioxidant activities were found in wines macerated for 15 days.

Geostatistical interpolation of available copper in orchard soil as influenced by planting duration.

Science.gov (United States)

Fu, Chuancheng; Zhang, Haibo; Tu, Chen; Li, Lianzhen; Luo, Yongming

2018-01-01

Mapping the spatial distribution of available copper (A-Cu) in orchard soils is important in agriculture and environmental management. However, data on the distribution of A-Cu in orchard soils is usually highly variable and severely skewed due to the continuous input of fungicides. In this study, ordinary kriging combined with planting duration (OK_PD) is proposed as a method for improving the interpolation of soil A-Cu. Four normal distribution transformation methods, namely, the Box-Cox, Johnson, rank order, and normal score methods, were utilized prior to interpolation. A total of 317 soil samples were collected in the orchards of the Northeast Jiaodong Peninsula. Moreover, 1472 orchards were investigated to obtain a map of planting duration using Voronoi tessellations. The soil A-Cu content ranged from 0.09 to 106.05 with a mean of 18.10 mg kg -1 , reflecting the high availability of Cu in the soils. Soil A-Cu concentrations exhibited a moderate spatial dependency and increased significantly with increasing planting duration. All the normal transformation methods successfully decreased the skewness and kurtosis of the soil A-Cu and the associated residuals, and also computed more robust variograms. OK_PD could generate better spatial prediction accuracy than ordinary kriging (OK) for all transformation methods tested, and it also provided a more detailed map of soil A-Cu. Normal score transformation produced satisfactory accuracy and showed an advantage in ameliorating smoothing effect derived from the interpolation methods. Thus, normal score transformation prior to kriging combined with planting duration (NSOK_PD) is recommended for the interpolation of soil A-Cu in this area.

Insomnia with objective short sleep duration is associated with longer duration of insomnia in the Freiburg Insomnia Cohort compared to insomnia with normal sleep duration, but not with hypertension.

Science.gov (United States)

Johann, Anna F; Hertenstein, Elisabeth; Kyle, Simon D; Baglioni, Chiara; Feige, Bernd; Nissen, Christoph; McGinness, Alastair J; Riemann, Dieter; Spiegelhalder, Kai

2017-01-01

To replicate the association between insomnia with objective short sleep duration and hypertension, type 2 diabetes and duration of insomnia. Retrospective case-control study. Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg. 328 patients with primary insomnia classified according to DSM-IV criteria (125 males, 203 females, 44.3 ± 12.2 years). N/A. All participants were investigated using polysomnography, blood pressure measurements, and fasting routine laboratory. Insomnia patients with short sleep duration (insomnia compared to those with normal sleep duration (≥ 6 hours) in the first night of laboratory sleep. Insomnia patients who were categorised as short sleepers in either night were not more likely to suffer from hypertension (systolic blood pressure of ≥ 140 mm Hg, diastolic blood pressure of ≥ 90 mm Hg, or a previously established diagnosis). Data analysis showed that insomnia patients with objective short sleep duration were not more likely to suffer from type 2 diabetes (fasting plasma glucose level of ≥ 126 mg/dl, or a previously established diagnosis). However, the diabetes analysis was only based on a very small number of diabetes cases. As a new finding, insomnia patients who were categorised as short sleepers in either night presented with increases in liver enzyme levels. The finding on insomnia duration supports the concept of two distinct sub-groups of insomnia, namely insomnia with, and without, objectively determined short sleep duration. However, our data challenges previous findings that insomnia patients with short sleep duration are more likely to suffer from hypertension.

Developing Project Duration Models in Software Engineering

Institute of Scientific and Technical Information of China (English)

Pierre Bourque; Serge Oligny; Alain Abran; Bertrand Fournier

2007-01-01

Based on the empirical analysis of data contained in the International Software Benchmarking Standards Group(ISBSG) repository, this paper presents software engineering project duration models based on project effort. Duration models are built for the entire dataset and for subsets of projects developed for personal computer, mid-range and mainframeplatforms. Duration models are also constructed for projects requiring fewer than 400 person-hours of effort and for projectsre quiring more than 400 person-hours of effort. The usefulness of adding the maximum number of assigned resources as asecond independent variable to explain duration is also analyzed. The opportunity to build duration models directly fromproject functional size in function points is investigated as well.

Duration Adaptation Occurs Across the Sub- and Supra-Second Systems.

Science.gov (United States)

Shima, Shuhei; Murai, Yuki; Hashimoto, Yuki; Yotsumoto, Yuko

2016-01-01

After repetitive exposure to a stimulus of relatively short duration, a subsequent stimulus of long duration is perceived as being even longer, and after repetitive exposure to a stimulus of relatively long duration, a subsequent stimulus of short duration is perceived as being even shorter. This phenomenon is called duration adaptation, and has been reported only for sub-second durations. We examined whether duration adaptation also occurs for supra-second durations (Experiment 1) and whether duration adaptation occurs across sub- and supra-second durations (Experiment 2). Duration adaptation occurred not only for sub-second durations, but also for supra-second durations and across sub- and supra-second durations. These results suggest that duration adaptation involves an interval-independent system or two functionally related systems that are associated with both the sub- and supra-second durations.

Satellite-Based Sunshine Duration for Europe

Directory of Open Access Journals (Sweden)

Bodo Ahrens

2013-06-01

Full Text Available In this study, two different methods were applied to derive daily and monthly sunshine duration based on high-resolution satellite products provided by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT Satellite Application Facility on Climate Monitoring using data from Meteosat Second Generation (MSG SEVIRI (Spinning Enhanced Visible and Infrared Imager. The satellite products were either hourly cloud type or hourly surface incoming direct radiation. The satellite sunshine duration estimates were not found to be significantly different using the native 15-minute temporal resolution of SEVIRI. The satellite-based sunshine duration products give additional spatial information over the European continent compared with equivalent in situ-based products. An evaluation of the satellite sunshine duration by product intercomparison and against station measurements was carried out to determine their accuracy. The satellite data were found to be within ±1 h/day compared to high-quality Baseline Surface Radiation Network or surface synoptic observations (SYNOP station measurements. The satellite-based products differ more over the oceans than over land, mainly because of the treatment of fractional clouds in the cloud type-based sunshine duration product. This paper presents the methods used to derive the satellite sunshine duration products and the performance of the different retrievals. The main benefits and disadvantages compared to station-based products are also discussed.

The Reflective Learning Continuum: Reflecting on Reflection

Science.gov (United States)

Peltier, James W.; Hay, Amanda; Drago, William

2005-01-01

The importance of reflection to marketing educators is increasingly recognized. However, there is a lack of empirical research that considers reflection within the context of both the marketing and general business education literature. This article describes the use of an instrument that can be used to measure four identified levels of a…

Development and comparison of different intensity duration ...

African Journals Online (AJOL)

Nigerian Journal of Technology ... Microsoft Excel software was used to develop exponential, logarithmic and power intensity-duration-frequency models for return period (T) of duration-frequency models for return period (T) of between 2 years and 100 years using rainfall intensity data for durations of 2, 5, 10, 15, 30, 60, ...

Sleep Duration and Area-Level Deprivation in Twins.

Science.gov (United States)

Watson, Nathaniel F; Horn, Erin; Duncan, Glen E; Buchwald, Dedra; Vitiello, Michael V; Turkheimer, Eric

2016-01-01

We used quantitative genetic models to assess whether area-level deprivation as indicated by the Singh Index predicts shorter sleep duration and modifies its underlying genetic and environmental contributions. Participants were 4,218 adult twin pairs (2,377 monozygotic and 1,841 dizygotic) from the University of Washington Twin Registry. Participants self-reported habitual sleep duration. The Singh Index was determined by linking geocoding addresses to 17 indicators at the census-tract level using data from Census of Washington State and Census Tract Cartographic Boundary Files from 2000 and 2010. Data were analyzed using univariate and bivariate genetic decomposition and quantitative genetic interaction models that assessed A (additive genetics), C (common environment), and E (unique environment) main effects of the Singh Index on sleep duration and allowed the magnitude of residual ACE variance components in sleep duration to vary with the Index. The sample had a mean age of 38.2 y (standard deviation [SD] = 18), and was predominantly female (62%) and Caucasian (91%). Mean sleep duration was 7.38 h (SD = 1.20) and the mean Singh Index score was 0.00 (SD = 0.89). The heritability of sleep duration was 39% and the Singh Index was 12%. The uncontrolled phenotypic regression of sleep duration on the Singh Index showed a significant negative relationship between area-level deprivation and sleep length (b = -0.080, P sleep duration. For the quasi-causal bivariate model, there was a significant main effect of E (b(0E) = -0.063; standard error [SE] = 0.30; P sleep duration were significant for both A (b(0Au) = 0.734; SE = 0.020; P deprivation has a quasi-causal association with sleep duration, with greater deprivation being related to shorter sleep. As area-level deprivation increases, unique genetic and nonshared environmental residual variance in sleep duration increases. © 2016 Associated Professional Sleep Societies, LLC.

Sleep Duration and Area-Level Deprivation in Twins

Science.gov (United States)

Watson, Nathaniel F.; Horn, Erin; Duncan, Glen E.; Buchwald, Dedra; Vitiello, Michael V.; Turkheimer, Eric

2016-01-01

Study Objectives: We used quantitative genetic models to assess whether area-level deprivation as indicated by the Singh Index predicts shorter sleep duration and modifies its underlying genetic and environmental contributions. Methods: Participants were 4,218 adult twin pairs (2,377 monozygotic and 1,841 dizygotic) from the University of Washington Twin Registry. Participants self-reported habitual sleep duration. The Singh Index was determined by linking geocoding addresses to 17 indicators at the census-tract level using data from Census of Washington State and Census Tract Cartographic Boundary Files from 2000 and 2010. Data were analyzed using univariate and bivariate genetic decomposition and quantitative genetic interaction models that assessed A (additive genetics), C (common environment), and E (unique environment) main effects of the Singh Index on sleep duration and allowed the magnitude of residual ACE variance components in sleep duration to vary with the Index. Results: The sample had a mean age of 38.2 y (standard deviation [SD] = 18), and was predominantly female (62%) and Caucasian (91%). Mean sleep duration was 7.38 h (SD = 1.20) and the mean Singh Index score was 0.00 (SD = 0.89). The heritability of sleep duration was 39% and the Singh Index was 12%. The uncontrolled phenotypic regression of sleep duration on the Singh Index showed a significant negative relationship between area-level deprivation and sleep length (b = −0.080, P sleep duration. For the quasi-causal bivariate model, there was a significant main effect of E (b0E = −0.063; standard error [SE] = 0.30; P sleep duration were significant for both A (b0Au = 0.734; SE = 0.020; P sleep duration, with greater deprivation being related to shorter sleep. As area-level deprivation increases, unique genetic and nonshared environmental residual variance in sleep duration increases. Citation: Watson NF, Horn E, Duncan GE, Buchwald D, Vitiello MV, Turkheimer E. Sleep duration and area

Unemployment Duration over the Business Cycle

DEFF Research Database (Denmark)

Rosholm, Michael

1996-01-01

In this paper I study the way in which individual unemployment durations vary over the business cycle, as measured by the aggregate unemployment rate. I decompose the cyclical variations in observed unemployment durations into a composition al and a general part. The compositional part consists...

Sociosexuality, Morningness–Eveningness, and Sleep Duration

Directory of Open Access Journals (Sweden)

Christoph Randler

2016-01-01

Full Text Available Morningness–eveningness is the preference for different times of day for activity and sleep. Here, we addressed the effects of sleep behavior and morningness–eveningness on sociosexuality. Three hundred students (M age = 22.75 years, with 95% between 18 and 28 participated online, answering questions about morningness–eveningness (rMEQ [Reduced Morningness–Eveningness Questionnaire], midpoint of sleep on free days (MSF, sleep duration, and the Sociosexuality Orientation Inventory–Revised (SOI-R. The SOI-R contains three subscales, Behavior, Attitude, and Desire. Evening orientation and short sleep duration were related to a higher total SOI-R and to the three subscales. Based on the linear models, the strongest effect on sociosexuality was produced by gender (27% explained variance while age accounted for 6% of variance. Nonadditive variance explained by sleep–wake behavior was 7% (MSF, 4% (sleep duration, and 4% (rMEQ scores; 3% rMEQ-based typology. Older age was related to less-restricted sociosexuality, and men were less restricted than women in Attitude and Desire. Sleep duration and rMEQ scores were associated with Attitude and Desire; but only MSF was significantly related to Behavior. The data show that sleep–wake variables are associated with sociosexuality, with evening orientation and shorter sleep duration being related to a less-restricted sociosexuality.

Association between subjective actual sleep duration, subjective sleep need, age, body mass index, and gender in a large sample of young adults.

Science.gov (United States)

Kalak, Nadeem; Brand, Serge; Beck, Johannes; Holsboer-Trachsler, Edith; Wollmer, M Axel

2015-01-01

Poor sleep is a major health concern, and there is evidence that young adults are at increased risk of suffering from poor sleep. There is also evidence that sleep duration can vary as a function of gender and body mass index (BMI). We sought to replicate these findings in a large sample of young adults, and also tested the hypothesis that a smaller gap between subjective sleep duration and subjective sleep need is associated with a greater feeling of being restored. A total of 2,929 university students (mean age 23.24±3.13 years, 69.1% female) took part in an Internet-based survey. They answered questions related to demographics and subjective sleep patterns. We found no gender differences in subjective sleep duration, subjective sleep need, BMI, age, or feeling of being restored. Nonlinear associations were observed between subjective sleep duration, BMI, and feeling of being restored. Moreover, a larger discrepancy between subjective actual sleep duration and subjective sleep need was associated with a lower feeling of being restored. The present pattern of results from a large sample of young adults suggests that males and females do not differ with respect to subjective sleep duration, BMI, or feeling of being restored. Moreover, nonlinear correlations seemed to provide a more accurate reflection of the relationship between subjective sleep and demographic variables.

Morphology and phase structures of CW laser-induced oxide layers on iron surface with evolving reflectivity and colors

Energy Technology Data Exchange (ETDEWEB)

Wu, Taotao, E-mail: wutaotao@nint.ac.cn; Wang, Lijun; Wei, Chenghua; Zhou, Menglian; He, Minbo; Wu, Lixiong

2016-11-30

Highlights: • Firstly, iron samples with different color features were obtained by continuous wave laser irradiation depending on progressive durations. The real-time reflectivity and temperature of samples were measured. The color and the reflectivity evolution were related. They were both caused by the forming oxide films. • Secondly, laser-induced oxidation process of iron was studied by microscope, X-ray diffraction and Raman spectrum. The first formed magnetite made the surface reflectivity decline rapidly and caused the “positive feedback” effect because of molecular absorption. The later formed hematite oscillated the reflectivity by interference effect. • Lastly, the laser-induced oxide films were thin, orientated and badly crystallized. The Wagner oxidation theory was incapable of describing the non-isothermal and early stage oxidation process. So we emphasized that a precise oxidation model depending on the experiment and the optical constants of the laser-induced oxides must be studied. - Abstract: Laser-induced oxidation will change the laser reflectivity and color features of metal surface. Both changes can be theoretically calculated based on the oxidation kinetics and the optical constants of oxides. For the purpose of calculation, the laser-induced oxidation process of pure polycrystalline iron was studied. Samples with various color features were obtained by continuous wave Nd:YAG fiber laser (1.06 μm) irradiation depending on progressive durations in the intensity of 1.90 W/cm{sup 2}. The real-time reflectivity and temperature were measured with integral sphere and thermocouples. The irradiated surface morphology and phase structures were characterized by microscope, X-ray diffraction and Raman spectrum. It was found that the first formed magnetite made the surface reflectivity decline rapidly and caused the “positive feedback” effect because of molecular absorption. The later formed hematite oscillated the reflectivity by

Challenging Narcissus, or Reflecting on Reflecting.

Science.gov (United States)

Achilles, C. M.

The concept of reflective practice and teaching people to be reflective practitioners is examined. The document begins with a look at professional knowledge according to three prominent professionals in the educational administration field: Schon, Schein, and Achilles. "Reflective" strategies that could be incorporated into courses and…

Sleep Duration and Breast Cancer Phenotype

International Nuclear Information System (INIS)

Khawaja, A.; Rao, S.

2013-01-01

Emerging evidence suggests that short sleep is associated with an increased risk of cancer; however, little has been done to study the role of sleep on tumor characteristics. In this study, we evaluated the relationship between sleep duration and tumor phenotype in 972 breast cancer patients. Sleep duration was inversely associated with tumor grade (univariate P= 0.032), particularly in postmenopausal women (univariate P= 0.018). This association did not reach statistical significance after adjustments for age, race, body mass index, hormone replacement therapy use, alcohol consumption, smoking, and physical activity in the entire study sample (P= 0.052), but it remained statistically significant (P= 0.049) among post-menopausal patients. We did not observe a statistically significant association between sleep duration and stage at diagnosis, ER, or HER2 receptor status. These results present a modest association between short duration of sleep and higher grade breast cancer in post-menopausal women. Further work needs to be done to validate these findings.

Effects of pulse duration on magnetostimulation thresholds

Energy Technology Data Exchange (ETDEWEB)

Saritas, Emine U., E-mail: saritas@ee.bilkent.edu.tr [Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720-1762 (United States); Department of Electrical and Electronics Engineering, Bilkent University, Bilkent, Ankara 06800 (Turkey); National Magnetic Resonance Research Center (UMRAM), Bilkent University, Bilkent, Ankara 06800 (Turkey); Goodwill, Patrick W. [Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720-1762 (United States); Conolly, Steven M. [Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720-1762 (United States); Department of EECS, University of California, Berkeley, California 94720-1762 (United States)

2015-06-15

Purpose: Medical imaging techniques such as magnetic resonance imaging and magnetic particle imaging (MPI) utilize time-varying magnetic fields that are subject to magnetostimulation limits, which often limit the speed of the imaging process. Various human-subject experiments have studied the amplitude and frequency dependence of these thresholds for gradient or homogeneous magnetic fields. Another contributing factor was shown to be number of cycles in a magnetic pulse, where the thresholds decreased with longer pulses. The latter result was demonstrated on two subjects only, at a single frequency of 1.27 kHz. Hence, whether the observed effect was due to the number of cycles or due to the pulse duration was not specified. In addition, a gradient-type field was utilized; hence, whether the same phenomenon applies to homogeneous magnetic fields remained unknown. Here, the authors investigate the pulse duration dependence of magnetostimulation limits for a 20-fold range of frequencies using homogeneous magnetic fields, such as the ones used for the drive field in MPI. Methods: Magnetostimulation thresholds were measured in the arms of six healthy subjects (age: 27 ± 5 yr). Each experiment comprised testing the thresholds at eight different pulse durations between 2 and 125 ms at a single frequency, which took approximately 30–40 min/subject. A total of 34 experiments were performed at three different frequencies: 1.2, 5.7, and 25.5 kHz. A solenoid coil providing homogeneous magnetic field was used to induce stimulation, and the field amplitude was measured in real time. A pre-emphasis based pulse shaping method was employed to accurately control the pulse durations. Subjects reported stimulation via a mouse click whenever they felt a twitching/tingling sensation. A sigmoid function was fitted to the subject responses to find the threshold at a specific frequency and duration, and the whole procedure was repeated at all relevant frequencies and pulse durations

Effects of pulse duration on magnetostimulation thresholds

International Nuclear Information System (INIS)

Saritas, Emine U.; Goodwill, Patrick W.; Conolly, Steven M.

2015-01-01

Purpose: Medical imaging techniques such as magnetic resonance imaging and magnetic particle imaging (MPI) utilize time-varying magnetic fields that are subject to magnetostimulation limits, which often limit the speed of the imaging process. Various human-subject experiments have studied the amplitude and frequency dependence of these thresholds for gradient or homogeneous magnetic fields. Another contributing factor was shown to be number of cycles in a magnetic pulse, where the thresholds decreased with longer pulses. The latter result was demonstrated on two subjects only, at a single frequency of 1.27 kHz. Hence, whether the observed effect was due to the number of cycles or due to the pulse duration was not specified. In addition, a gradient-type field was utilized; hence, whether the same phenomenon applies to homogeneous magnetic fields remained unknown. Here, the authors investigate the pulse duration dependence of magnetostimulation limits for a 20-fold range of frequencies using homogeneous magnetic fields, such as the ones used for the drive field in MPI. Methods: Magnetostimulation thresholds were measured in the arms of six healthy subjects (age: 27 ± 5 yr). Each experiment comprised testing the thresholds at eight different pulse durations between 2 and 125 ms at a single frequency, which took approximately 30–40 min/subject. A total of 34 experiments were performed at three different frequencies: 1.2, 5.7, and 25.5 kHz. A solenoid coil providing homogeneous magnetic field was used to induce stimulation, and the field amplitude was measured in real time. A pre-emphasis based pulse shaping method was employed to accurately control the pulse durations. Subjects reported stimulation via a mouse click whenever they felt a twitching/tingling sensation. A sigmoid function was fitted to the subject responses to find the threshold at a specific frequency and duration, and the whole procedure was repeated at all relevant frequencies and pulse durations

Type III Radio Burst Duration and SEP Events

Science.gov (United States)

Gopalswamy, N.; Makela, P.; Xie, H.

2010-01-01

Long-duration (>15 min), low-frequency (25 MeV. The 1-MHz duration of the type III burst (28 rein) is near the median value of type III durations found for gradual SEP events and ground level enhancement (GLE) events. Yet, there was no sign of SEP events. On the other hand, two other type III bursts from the same active region had similar duration but accompanied by WAVES type 11 bursts; these bursts were also accompanied by SEP events detected by SOHO/ERNE. This study suggests that the type III burst duration may not be a good indicator of an SEP event, consistent with the statistical study of Cliver and Ling (2009, ApJ ).

Duration of patients’ visits to the hospital emergency department

Directory of Open Access Journals (Sweden)

Karaca Zeynal

2012-11-01

Full Text Available Abstract Background Length of stay is an important indicator of quality of care in Emergency Departments (ED. This study explores the duration of patients’ visits to the ED for which they are treated and released (T&R. Methods Retrospective data analysis and multivariate regression analysis were conducted to investigate the duration of T&R ED visits. Duration for each visit was computed by taking the difference between admission and discharge times. The Healthcare Cost and Utilization Project (HCUP State Emergency Department Databases (SEDD for 2008 were used in the analysis. Results The mean duration of T&R ED visit was 195.7 minutes. The average duration of ED visits increased from 8 a.m. until noon, then decreased until midnight at which we observed an approximately 70-minute spike in average duration. We found a substantial difference in mean duration of ED visits (over 90 minutes between Mondays and other weekdays during the transition time from the evening of the day before to the early morning hours. Black / African American patients had a 21.4-minute longer mean duration of visits compared to white patients. The mean duration of visits at teaching hospitals was substantially longer than at non-teaching hospitals (243.8 versus 175.6 minutes. Hospitals with large bed size were associated with longer duration of visits (222.2 minutes when compared to hospitals with small bed size (172.4 minutes or those with medium bed size (166.5 minutes. The risk-adjusted results show that mean duration of visits on Mondays are longer by about 4 and 9 percents when compared to mean duration of visits on non-Monday workdays and weekends, respectively. Conclusions The duration of T&R ED visits varied significantly by admission hour, day of the week, patient volume, patient characteristics, hospital characteristics and area characteristics.

Association between QRS duration and obstructive sleep apnea.

Science.gov (United States)

Gupta, Shuchita; Cepeda-Valery, Beatriz; Romero-Corral, Abel; Shamsuzzaman, Abu; Somers, Virend K; Pressman, Gregg S

2012-12-15

Both obstructive sleep apnea (OSA) and prolonged QRS duration are associated with hypertension, heart failure, and sudden cardiac death. However, possible links between QRS duration and OSA have not been explored. Cross-sectional study of 221 patients who underwent polysomnography at our center. Demographics, cardiovascular risk factors and ECG were collected to explore a relationship between OSA and QRS duration. The apnea-hypopnea index (AHI) was positively correlated with QRS duration (r = 0.141, p = 0.03). Patients were divided into 3 groups: AHI 30 (55). The mean QRS duration prolonged significantly as OSA worsened (AHI 30, 95 ± 19.9 ms, p = 0.001). QRS ≥ 100 ms was present in 12.7% of patients with severe OSA compared with 0% in the rest of the sample (p < 0.0001). After adjustment for age, race, and cardiovascular risk factors, this association remained significant in women but not in men. QRS duration and OSA were significantly associated. Severity of OSA independently predicted prolonged QRS in women but not men. Nevertheless, prolongation of QRS duration in either sex may potentiate arrhythmic risks associated with OSA.

Sleep Duration and Depressive Symptoms: A Gene-Environment Interaction

Science.gov (United States)

Watson, Nathaniel F.; Harden, Kathryn Paige; Buchwald, Dedra; Vitiello, Michael V.; Pack, Allan I.; Strachan, Eric; Goldberg, Jack

2014-01-01

Objective: We used quantitative genetic models to assess whether sleep duration modifies genetic and environmental influences on depressive symptoms. Method: Participants were 1,788 adult twins from 894 same-sex twin pairs (192 male and 412 female monozygotic [MZ] pairs, and 81 male and 209 female dizygotic [DZ] pairs] from the University of Washington Twin Registry. Participants self-reported habitual sleep duration and depressive symptoms. Data were analyzed using quantitative genetic interaction models, which allowed the magnitude of additive genetic, shared environmental, and non-shared environmental influences on depressive symptoms to vary with sleep duration. Results: Within MZ twin pairs, the twin who reported longer sleep duration reported fewer depressive symptoms (ec = -0.17, SE = 0.06, P sleep duration interaction effect on depressive symptoms (a'c = 0.23, SE = 0.08, P sleep duration and depressive symptoms. Among individuals with sleep duration within the normal range (7-8.9 h/night), the total heritability (h2) of depressive symptoms was approximately 27%. However, among individuals with sleep duration within the low (sleep duration extremes (5 h/night: h2 = 53%; 10 h/night: h2 = 49%). Conclusion: Genetic contributions to depressive symptoms increase at both short and long sleep durations. Citation: Watson NF; Harden KP; Buchwald D; Vitiello MV; Pack AI; Stachan E; Goldberg J. Sleep duration and depressive symptoms: a gene-environment interaction. SLEEP 2014;37(2):351-358. PMID:24497663

duration diabetes mellitus

African Journals Online (AJOL)

... group, type of diabetes, age of onset and duration of diabetes), presence of retinopathy, markers of nephropathy and biochemical variables. ... type 2 diabetes and for each ethnic group. Results. ... time of diabetes diagnosis in blacks than Indians. In the type ... countries, minority groups and disadvantaged communities in.

Adaptation to an Illusory Duration: Nothing Like the Real Thing?

Directory of Open Access Journals (Sweden)

John Hotchkiss

2012-05-01

Full Text Available Recent work has shown that adapting to a visual or auditory stimulus of a particular duration leads to a repulsive distortion of the perceived duration of a subsequently presented test stimulus. This distortion seems to be modality-specific and manifests itself as an expansion or contraction of perceived duration dependent upon whether the test stimulus is longer or shorter than the adapted duration. It has been shown (Berger et al 2003, Journal of Vision 3, 406–412 that perceived events can be as effective as actual events in inducing improvements in performance. In light of this, we investigated whether an illusory visual duration was capable of inducing a duration after-effect in a visual test stimulus that was actually no different in duration from the adaptor. Pairing a visual stimulus with a concurrent auditory stimulus of subtly longer or shorter duration expands or contracts the duration of the visual stimulus. We mapped out this effect and then chose two auditory durations (one long, one short that produced the maximum distortion in the perceived duration of the visual stimulus. After adapting to this bimodal stimulus, our participants were asked to reproduce a visual duration. Group data showed that participants, on average, reproduced the physical duration of the visual test stimulus accurately; in other words, there was no consistent effect of adaptation to an illusory duration.

Sleep Quality, Sleep Duration, and the Risk of Coronary Heart Disease: A Prospective Cohort Study With 60,586 Adults.

Science.gov (United States)

Lao, Xiang Qian; Liu, Xudong; Deng, Han-Bing; Chan, Ta-Chien; Ho, Kin Fai; Wang, Feng; Vermeulen, Roel; Tam, Tony; Wong, Martin C S; Tse, L A; Chang, Ly-Yun; Yeoh, Eng-Kiong

2018-01-15

There is limited information on the relationship between risk of cardiovascular disease and the joint effects of sleep quality and sleep duration, especially from large, prospective, cohort studies. This study is to prospectively investigate the joint effects of sleep quality and sleep duration on the development of coronary heart disease. This study examined 60,586 adults aged 40 years or older. A self-administered questionnaire was used to collect information on sleep quality and sleep duration as well as a wide range of potential confounders. Events of coronary heart disease were self-reported in subsequent medical examinations. Two types of Sleep Score (multiplicative and additive) were constructed to reflect the participants' sleep profiles, considering both sleep quality and sleep duration. The Cox regression model was used to estimate the hazard ratio (HR) and the 95% confidence interval (CI). A total of 2,740 participants (4.5%) reported new events of coronary heart disease at follow-up. For sleep duration, participants in the group of 8 h/d) did not reach statistical significance (HR: 1.11, 95% CI: 0.98-1.26). For sleep quality, both dreamy sleep (HR: 1.21, 95% CI: 1.10-1.32) and difficult to fall asleep/use of sleeping pills or drugs (HR: 1.40, 95% CI: 1.25-1.56) were associated with an increased risk of the disease. Participants in the lowest quartile of multiplicative Sleep Score (HR: 1.31, 95% CI: 1.16-1.47) and of additive sleep score (HR: 1.31, 95% CI: 1.16-1.47) were associated with increased risk of coronary heart disease compared with those in the highest quartile. Both short sleep duration and poor sleep quality are associated with the risk of coronary heart disease. The association for long sleep duration does not reach statistical significance. Lower Sleep Score (poorer sleep profile) increases the risk of coronary heart disease, suggesting the importance of considering sleep duration and sleep quality together when developing strategies to

On the Limitation of Warranty Duration.

OpenAIRE

Emons, Winand

1989-01-01

This paper analyzes the frequently-observed phenomenon that firms offer product warranties that are of much shorter duration than the life expectancy of these products. It is shown that competitive equilibria may entail limitation of warranty duration if firms face adverse selection problems with respect to different consumers. Copyright 1989 by Blackwell Publishing Ltd.

Earth-Space Links and Fade-Duration Statistics

Science.gov (United States)

Davarian, Faramaz

1996-01-01

In recent years, fade-duration statistics have been the subject of several experimental investigations. A good knowledge of the fade-duration distribution is important for the assessment of a satellite communication system's channel dynamics: What is a typical link outage duration? How often do link outages exceeding a given duration occur? Unfortunately there is yet no model that can universally answer the above questions. The available field measurements mainly come from temperate climatic zones and only from a few sites. Furthermore, the available statistics are also limited in the choice of frequency and path elevation angle. Yet, much can be learned from the available information. For example, we now know that the fade-duration distribution is approximately lognormal. Under certain conditions, we can even determine the median and other percentiles of the distribution. This paper reviews the available data obtained by several experimenters in different parts of the world. Areas of emphasis are mobile and fixed satellite links. Fades in mobile links are due to roadside-tree shadowing, whereas fades in fixed links are due to rain attenuation.

Optimal sequence of landfills in solid waste management

Energy Technology Data Exchange (ETDEWEB)

Andre, F.J. [Universidad Pablo de Olavide (Spain); Cerda, E. [Universidad Complutense de Madrid (Spain)

2001-07-01

Given that landfills are depletable and replaceable resources, the right approach, when dealing with landfill management, is that of designing an optimal sequence of landfills rather than designing every single landfill separately. In this paper, we use Optimal Control models, with mixed elements of both continuous-and discrete-time problems, to determine an optimal sequence of landfills, as regarding their capacity and lifetime. The resulting optimization problems involve splitting a time horizon of planning into several subintervals, the length of which has to be decided. In each of the subintervals some costs, the amount of which depends on the value of the decision variables, have to be borne. The obtained results may be applied to other economic problems such as private and public investments, consumption decisions on durable goods, etc. (Author)

Atypical pattern of discriminating sound features in adults with Asperger syndrome as reflected by the mismatch negativity.

Science.gov (United States)

Kujala, T; Aho, E; Lepistö, T; Jansson-Verkasalo, E; Nieminen-von Wendt, T; von Wendt, L; Näätänen, R

2007-04-01

Asperger syndrome, which belongs to the autistic spectrum of disorders, is characterized by deficits of social interaction and abnormal perception, like hypo- or hypersensitivity in reacting to sounds and discriminating certain sound features. We determined auditory feature discrimination in adults with Asperger syndrome with the mismatch negativity (MMN), a neural response which is an index of cortical change detection. We recorded MMN for five different sound features (duration, frequency, intensity, location, and gap). Our results suggest hypersensitive auditory change detection in Asperger syndrome, as reflected in the enhanced MMN for deviant sounds with a gap or shorter duration, and speeded MMN elicitation for frequency changes.

Strong motion duration and earthquake magnitude relationships

International Nuclear Information System (INIS)

Salmon, M.W.; Short, S.A.; Kennedy, R.P.

1992-06-01

Earthquake duration is the total time of ground shaking from the arrival of seismic waves until the return to ambient conditions. Much of this time is at relatively low shaking levels which have little effect on seismic structural response and on earthquake damage potential. As a result, a parameter termed ''strong motion duration'' has been defined by a number of investigators to be used for the purpose of evaluating seismic response and assessing the potential for structural damage due to earthquakes. This report presents methods for determining strong motion duration and a time history envelope function appropriate for various evaluation purposes, for earthquake magnitude and distance, and for site soil properties. There are numerous definitions of strong motion duration. For most of these definitions, empirical studies have been completed which relate duration to earthquake magnitude and distance and to site soil properties. Each of these definitions recognizes that only the portion of an earthquake record which has sufficiently high acceleration amplitude, energy content, or some other parameters significantly affects seismic response. Studies have been performed which indicate that the portion of an earthquake record in which the power (average rate of energy input) is maximum correlates most closely with potential damage to stiff nuclear power plant structures. Hence, this report will concentrate on energy based strong motion duration definitions

Call Duration Characteristics based on Customers Location

Directory of Open Access Journals (Sweden)

Žvinys Karolis

2014-05-01

Full Text Available Nowadays a lot of different researches are performed based on call duration distributions (CDD analysis. However, the majority of studies are linked with social relationships between the people. Therefore the scarcity of information, how the call duration is associated with a user's location, is appreciable. The goal of this paper is to reveal the ties between user's voice call duration and the location of call. For this reason we analyzed more than 5 million calls from real mobile network, which were made over the base stations located in rural areas, roads, small towns, business and entertainment centers, residential districts. According to these site types CDD’s and characteristic features for call durations are given and discussed. Submitted analysis presents the users habits and behavior as a group (not an individual. The research showed that CDD’s of customers being them in different locations are not equal. It has been found that users at entertainment, business centers are tend to talk much shortly, than people being at home. Even more CDD can be distorted strongly, when machinery calls are evaluated. Hence to apply a common CDD for a whole network it is not recommended. The study also deals with specific parameters of call duration for distinguished user groups, the influence of network technology for call duration is considered.

The Frequency and Duration of Uterine Contractions during Labour

African Journals Online (AJOL)

1974-04-17

Apr 17, 1974 ... n-e;.l. Fig. 12. Indian primigravidas: duration of contractions. Fig. 11. Indian multiparas: duration of contractions. Fig. 10. Black primigravidas (all ages): duration of con- tractiom. Indian multiparas: Fig. 11 shows the duration of con- tractions in labour of Indian multiparas studied. Again, the pattern is similar to ...

The Duration of Motor Responses Evoked with Intracortical Microstimulation in Rats Is Primarily Modulated by Stimulus Amplitude and Train Duration.

Directory of Open Access Journals (Sweden)

Meghan Watson

Full Text Available Microstimulation of brain tissue plays a key role in a variety of sensory prosthetics, clinical therapies and research applications, however the effects of stimulation parameters on the responses they evoke remain widely unknown. In particular, the effects of parameters when delivered in the form of a stimulus train as opposed to a single pulse are not well understood despite the prevalence of stimulus train use. We aimed to investigate the contribution of each parameter of a stimulus train to the duration of the motor responses they evoke in forelimb muscles. We used constant-current, biphasic, square wave pulse trains in acute terminal experiments under ketamine anaesthesia. Stimulation parameters were systematically tested in a pair-wise fashion in the caudal forelimb region of the motor cortex in 7 Sprague-Dawley rats while motor evoked potential (MEP recordings from the forelimb were used to quantify the influence of each parameter in the train. Stimulus amplitude and train duration were shown to be the dominant parameters responsible for increasing the total duration of the MEP, while interphase interval had no effect. Increasing stimulus frequency from 100-200 Hz or pulse duration from 0.18-0.34 ms were also effective methods of extending response durations. Response duration was strongly correlated with peak time and amplitude. Our findings suggest that motor cortex intracortical microstimulations are often conducted at a higher frequency rate and longer train duration than necessary to evoke maximal response duration. We demonstrated that the temporal properties of the evoked response can be both predicted by certain response metrics and modulated via alterations to the stimulation signal parameters.

Mental Summation of Temporal Duration within and across Senses.

Directory of Open Access Journals (Sweden)

Kohske Takahashi

Full Text Available Perceiving, memorizing, and estimating temporal durations are key cognitive functions in everyday life. In this study, a duration summation paradigm was used to examine whether summation of temporal durations introduces an underestimation or overestimation bias, and whether this bias is common to visual and auditory modalities. Two within- or across-modality stimuli were presented sequentially for variable durations. Participants were asked to reproduce the sum of the two durations (0.6-1.1 s. We found that the sum of two durations was overestimated regardless of stimulus modalities. A subsequent control experiment indicated that the overestimation bias arose from the summation process, not perceptual or memory processes. Furthermore, we observed strong positive correlations between the overestimation bias for different sensory modalities within participants. These results suggest that the sum of two durations is overestimated, and that supra-modal processes may be responsible for this overestimation bias.

[Associations of the work duration, sleep duration and number of holidays with an exaggerated blood pressure response during an exercise stress test among workers].

Science.gov (United States)

Michishita, Ryoma; Ohta, Masanori; Ikeda, Masaharu; Jiang, Ying; Yamato, Hiroshi

2016-01-01

It has been reported that an exaggerated systolic blood pressure (ESBP) response during exercise, even if resting blood pressure is normal, is associated with an increased risk of future hypertension and cardiovascular disease (CVD). This study was designed to investigate the relationships of work duration, sleep duration and number of holidays with blood pressure response during an exercise stress test among normotensive workers. The subjects were 362 normotensive workers (79 males and 283 females; age, 49.1 years). A multi-stage graded submaximal exercise stress test was performed on each subject using an electric bicycle ergometer. The workload was increased every 3 minutes, and blood pressure was measured at rest and during the last 1 minute of each stage. In this study, an ESBP response during exercise was defined according to the criteria of the Framingham Study (peak systolic blood pressure ≥210 mmHg in males, or ≥190 mmHg in females). Working environments, work duration, sleep duration, number of holidays, and physical activity during commuting and work, and leisure time exercise duration were evaluated using a questionnaire. An ESBP response during exercise was observed in 94 (26.0%) workers. The adjusted odds ratio for the prevalence of an ESBP response during exercise was found to be significantly higher with an increase in work duration, decreases in sleep duration and number of holidays (pwork duration with lowest sleep duration and number of holidays groups had significantly higher adjusted odds ratio for the prevalence of an ESBP response during exercise than the lowest work duration with highest sleep duration and number of holidays groups (pwork duration, short sleep duration and small number of holidays.

Seismic reflection imaging, accounting for primary and multiple reflections

Science.gov (United States)

Wapenaar, Kees; van der Neut, Joost; Thorbecke, Jan; Broggini, Filippo; Slob, Evert; Snieder, Roel

2015-04-01

Imaging of seismic reflection data is usually based on the assumption that the seismic response consists of primary reflections only. Multiple reflections, i.e. waves that have reflected more than once, are treated as primaries and are imaged at wrong positions. There are two classes of multiple reflections, which we will call surface-related multiples and internal multiples. Surface-related multiples are those multiples that contain at least one reflection at the earth's surface, whereas internal multiples consist of waves that have reflected only at subsurface interfaces. Surface-related multiples are the strongest, but also relatively easy to deal with because the reflecting boundary (the earth's surface) is known. Internal multiples constitute a much more difficult problem for seismic imaging, because the positions and properties of the reflecting interfaces are not known. We are developing reflection imaging methodology which deals with internal multiples. Starting with the Marchenko equation for 1D inverse scattering problems, we derived 3D Marchenko-type equations, which relate reflection data at the surface to Green's functions between virtual sources anywhere in the subsurface and receivers at the surface. Based on these equations, we derived an iterative scheme by which these Green's functions can be retrieved from the reflection data at the surface. This iterative scheme requires an estimate of the direct wave of the Green's functions in a background medium. Note that this is precisely the same information that is also required by standard reflection imaging schemes. However, unlike in standard imaging, our iterative Marchenko scheme retrieves the multiple reflections of the Green's functions from the reflection data at the surface. For this, no knowledge of the positions and properties of the reflecting interfaces is required. Once the full Green's functions are retrieved, reflection imaging can be carried out by which the primaries and multiples are

Mathematical-model study of servo system with pulse-duration control of micromovements

International Nuclear Information System (INIS)

Dement'eva, M.A.; Leonov, A.P.; Popov, V.V.; Skugarevskii, A.I.; Ustinov, E.A.; Chernyavskii, N.N.

1988-01-01

A number of digital servo systems with pulse-duration control have been developed at the Institute of High Energy Physics for the instruments of the scanning and measurement system and various experimental setups. They are based on stock transistor bridge stages, whose loads are high-speed servomotors with printed-circuit armature windings. Study of these servo systems by traditional methods, which are based on Laplace transforms, or by mean values with expansion of the current pulse into a Fourier transform yields approximate results and does not reflect the actual processes that take place in a pulse servo system. They attempt to develop a method and extend it to the study of high-speed servo systems in the area of micromovements and quasistationary velocity without position or velocity feedback

An investigation of the spatial selectivity of the duration after-effect.

Science.gov (United States)

Maarseveen, Jim; Hogendoorn, Hinze; Verstraten, Frans A J; Paffen, Chris L E

2017-01-01

Adaptation to the duration of a visual stimulus causes the perceived duration of a subsequently presented stimulus with a slightly different duration to be skewed away from the adapted duration. This pattern of repulsion following adaptation is similar to that observed for other visual properties, such as orientation, and is considered evidence for the involvement of duration-selective mechanisms in duration encoding. Here, we investigated whether the encoding of duration - by duration-selective mechanisms - occurs early on in the visual processing hierarchy. To this end, we investigated the spatial specificity of the duration after-effect in two experiments. We measured the duration after-effect at adapter-test distances ranging between 0 and 15° of visual angle and for within- and between-hemifield presentations. We replicated the duration after-effect: the test stimulus was perceived to have a longer duration following adaptation to a shorter duration, and a shorter duration following adaptation to a longer duration. Importantly, this duration after-effect occurred at all measured distances, with no evidence for a decrease in the magnitude of the after-effect at larger distances or across hemifields. This shows that adaptation to duration does not result from adaptation occurring early on in the visual processing hierarchy. Instead, it seems likely that duration information is a high-level stimulus property that is encoded later on in the visual processing hierarchy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Computer use, sleep duration and health symptoms

DEFF Research Database (Denmark)

Nuutinen, Teija; Roos, Eva; Ray, Carola

2014-01-01

OBJECTIVES: This study investigated whether computer use is associated with health symptoms through sleep duration among 15-year olds in Finland, France and Denmark. METHODS: We used data from the WHO cross-national Health Behaviour in School-aged Children study collected in Finland, France...... and Denmark in 2010, including data on 5,402 adolescents (mean age 15.61 (SD 0.37), girls 53 %). Symptoms assessed included feeling low, irritability/bad temper, nervousness, headache, stomachache, backache, and feeling dizzy. We used structural equation modeling to explore the mediating effect of sleep...... duration on the association between computer use and symptom load. RESULTS: Adolescents slept approximately 8 h a night and computer use was approximately 2 h a day. Computer use was associated with shorter sleep duration and higher symptom load. Sleep duration partly mediated the association between...

Reflection and Non-Reflection of Particle Wavepackets

Science.gov (United States)

Cox, Timothy; Lekner, John

2008-01-01

Exact closed-form solutions of the time-dependent Schrodinger equation are obtained, describing the propagation of wavepackets in the neighbourhood of a potential. Examples given include zero reflection, total reflection and partial reflection of the wavepacket, for the sech[superscript 2]x/a, 1/x[superscript 2] and delta(x) potentials,…

Factors affecting gestation duration in the bitch.

Science.gov (United States)

Eilts, Bruce E; Davidson, Autumn P; Hosgood, Giselle; Paccamonti, Dale L; Baker, David G

2005-07-15

A retrospective analysis was performed to determine the effects of age, breed, parity, and litter size on the duration of gestation in the bitch. Bitches at two locations were monitored from breeding to whelping. A total of 764 litters whelped from 308 bitches (36 large hounds, 34 Golden Retrievers, 23 German Shepherd Dogs (GSD), and 215 Labrador Retrievers). By breed, the number of whelpings was 152, 72, 58, and 482 for the hounds, Golden Retrievers, German Shepherd Dogs, and Labrador Retrievers, respectively. Whelping was predicted to be 57 d from the first day of cytologic diestrus in the hounds or 65 d from the initial progesterone rise in the other breeds. The average gestation duration (calculated as 8 d prior to Day 1 of cytologic diestrus in hounds or measured from the initial progesterone rise in other breeds) by breed (days +/- S.D.) was 66.0 +/- 2.8, 64.7 +/- 1.5, 63.6 +/- 2.1, and 62.9 +/- 1.3 for the hounds, Golden Retrievers, German Shepherd Dogs, and Labrador Retrievers, respectively. The relationship of age, breed, parity, and litter size with the difference in gestation duration was evaluated using log linear modeling. Age or parity had no effect on gestation duration. Compared to Labrador Retrievers, the German Shepherd Dogs, Golden Retrievers and hounds were more likely to have a longer gestation duration; three, four and nearly eight times as likely, respectively. Bitches whelping four or fewer pups were significantly more likely to have a longer gestation duration than those whelping five or more pups; the prolongation averaging 1 d.

Economic impact of antidepressant treatment duration in naturalistic conditions.

Science.gov (United States)

Tournier, M; Crott, R; Gaudron, Y; Verdoux, H

2013-05-01

To assess the economic impact of the duration of antidepressant drug treatment in a real-life setting. A historical fixed cohort study included 27 917 patients aged 18 and over with a new antidepressant treatment registered in the national insurance database. The economic impact concerned healthcare expenditure in the first 3 months after treatment discontinuation. Generalized linear models were used to compare two groups of treatment duration: adjustment for care costs before and during treatment episode, gender, age, chronic diseases, welfare and prescriber specialty, total healthcare costs (in log) [-0.06 (-0.14;0.01) P = 0.11] and psychiatric care costs (in square root) [-0.08 (-0.41;0.25) P = 0.6] were similar in both groups. Non-psychiatric care costs were significantly lower in the 'long treatment duration' group compared with the 'short treatment duration' group [-11.4 (-15.8; -7.0) P costs over the antidepressant treatment episode were larger in the 'long treatment duration' group compared with the 'short treatment duration' group. With regard to healthcare costs and global health, antidepressant drug treatments of short duration appear less effective than treatment of recommended duration. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

Effect of reflective practice education on self-reflection, insight, and reflective thinking among experienced nurses: a pilot study.

Science.gov (United States)

Asselin, Marilyn E; Fain, James A

2013-01-01

A mixed-method study was conducted to determine whether nurses' participation in a reflective practice continuing education program using a structured reflection model makes a difference in nurses' self-reflection, insight, and reflective thinking about clinical practice situations. Findings suggested that use of structured reflection using question cues, written narratives, and peer-facilitated reflection increased nurses' engagement in self-reflection and enhanced reflective thinking in practice. Including reflective practice education in novice orientation and preceptor training may be beneficial.

High-voltage variable-duration pulse generator

International Nuclear Information System (INIS)

Anisimova, T.E.; Akkuratov, E.V.; Gromovenko, V.M.; Nikonov, Yu.P.; Malinin, A.N.

1988-01-01

A high-voltage generator is described that allows pulse duration tau to be varied within wide limits and has high efficiency (at least 50% for tau = 0.5 tau/sub max/) and an amplitude of up to 5 kV, a repetition frequency of up to 200 Hz,and a variable duration of 0-30 μsec. The generator is used in the controller of an electron accelerator

Duration of therapy – Does it matter?

DEFF Research Database (Denmark)

Kramer Schmidt, Lotte; Bojesen, Anders Bo; Nielsen, Anette Søgaard

2018-01-01

Background The recommendations in clinical guidelines for duration of therapy for alcohol use disorder (AUD) are based on consensus decisions. In reality, we do not know the optimal duration of an alcohol treatment course. Methods A systematic review and meta-regression of randomized controlled...... project in itself may influence outcome in studies of psychosocial treatment for alcohol use disorder....... across studies. Treatment outcome was defined as long-term alcohol use measured in percentage of days abstinent (PDA), percentage of heavy days drinking (PHD), and/or proportion of participants abstinent (ABS). Results 48 studies encompassing 8984 participants. Mean planned duration of therapy: 18 (8...

A direct method for numerical solution of a class of nonlinear Volterra integro-differential equations and its application to the nonlinear fission and fusion reactor kinetics

International Nuclear Information System (INIS)

Nakahara, Yasuaki; Ise, Takeharu; Kobayashi, Kensuke; Itoh, Yasuyuki

1975-12-01

A new method has been developed for numerical solution of a class of nonlinear Volterra integro-differential equations with quadratic nonlinearity. After dividing the domain of the variable into subintervals, piecewise approximations are applied in the subintervals. The equation is first integrated over a subinterval to obtain the piecewise equation, to which six approximate treatments are applied, i.e. fully explicit, fully implicit, Crank-Nicolson, linear interpolation, quadratic and cubic spline. The numerical solution at each time step is obtained directly as a positive root of the resulting algebraic quadratic equation. The point reactor kinetics with a ramp reactivity insertion, linear temperature feedback and delayed neutrons can be described by one of this type of nonlinear Volterra integro-differential equations. The algorithm is applied to the Argonne benchmark problem and a model problem for a fast reactor without delayed neutrons. The fully implicit method has been found to be unconditionally stable in the sense that it always gives the positive real roots. The cubic spline method is divergent, and the other four methods are intermediate in between. From the estimation of the stability, convergency, accuracy and CPU time, it is concluded that the Crank-Nicolson method is best, then the linear interpolation method comes closely next to it. Discussions are also made on the possibility of applying the algorithm to the fusion reactor kinetics in the form of a nonlinear partial differential equation. (auth.)

Effect of electroless etching parameters on the growth and reflection properties of silicon nanowires

International Nuclear Information System (INIS)

Ozdemir, Baris; Unalan, Husnu Emrah; Kulakci, Mustafa; Turan, Rasit

2011-01-01

Vertically aligned silicon nanowire (Si NW) arrays have been fabricated over large areas using an electroless etching (EE) method, which involves etching of silicon wafers in a silver nitrate and hydrofluoric acid based solution. A detailed parametric study determining the relationship between nanowire morphology and time, temperature, solution concentration and starting wafer characteristics (doping type, resistivity, crystallographic orientation) is presented. The as-fabricated Si NW arrays were analyzed by field emission scanning electron microscope (FE-SEM) and a linear dependency of nanowire length to both temperature and time was obtained and the change in the growth rate of Si NWs at increased etching durations was shown. Furthermore, the effects of EE parameters on the optical reflectivity of the Si NWs were investigated in this study. Reflectivity measurements show that the 42.8% reflectivity of the starting silicon wafer drops to 1.3%, recorded for 10 μm long Si NW arrays. The remarkable decrease in optical reflectivity indicates that Si NWs have a great potential to be utilized in radial or coaxial p-n heterojunction solar cells that could provide orthogonal photon absorption and enhanced carrier collection.

Effect of electroless etching parameters on the growth and reflection properties of silicon nanowires.

Science.gov (United States)

Ozdemir, Baris; Kulakci, Mustafa; Turan, Rasit; Unalan, Husnu Emrah

2011-04-15

Vertically aligned silicon nanowire (Si NW) arrays have been fabricated over large areas using an electroless etching (EE) method, which involves etching of silicon wafers in a silver nitrate and hydrofluoric acid based solution. A detailed parametric study determining the relationship between nanowire morphology and time, temperature, solution concentration and starting wafer characteristics (doping type, resistivity, crystallographic orientation) is presented. The as-fabricated Si NW arrays were analyzed by field emission scanning electron microscope (FE-SEM) and a linear dependency of nanowire length to both temperature and time was obtained and the change in the growth rate of Si NWs at increased etching durations was shown. Furthermore, the effects of EE parameters on the optical reflectivity of the Si NWs were investigated in this study. Reflectivity measurements show that the 42.8% reflectivity of the starting silicon wafer drops to 1.3%, recorded for 10 µm long Si NW arrays. The remarkable decrease in optical reflectivity indicates that Si NWs have a great potential to be utilized in radial or coaxial p-n heterojunction solar cells that could provide orthogonal photon absorption and enhanced carrier collection.

Effect of electroless etching parameters on the growth and reflection properties of silicon nanowires

Science.gov (United States)

Ozdemir, Baris; Kulakci, Mustafa; Turan, Rasit; Emrah Unalan, Husnu

2011-04-01

Vertically aligned silicon nanowire (Si NW) arrays have been fabricated over large areas using an electroless etching (EE) method, which involves etching of silicon wafers in a silver nitrate and hydrofluoric acid based solution. A detailed parametric study determining the relationship between nanowire morphology and time, temperature, solution concentration and starting wafer characteristics (doping type, resistivity, crystallographic orientation) is presented. The as-fabricated Si NW arrays were analyzed by field emission scanning electron microscope (FE-SEM) and a linear dependency of nanowire length to both temperature and time was obtained and the change in the growth rate of Si NWs at increased etching durations was shown. Furthermore, the effects of EE parameters on the optical reflectivity of the Si NWs were investigated in this study. Reflectivity measurements show that the 42.8% reflectivity of the starting silicon wafer drops to 1.3%, recorded for 10 µm long Si NW arrays. The remarkable decrease in optical reflectivity indicates that Si NWs have a great potential to be utilized in radial or coaxial p-n heterojunction solar cells that could provide orthogonal photon absorption and enhanced carrier collection.

Damping of Crank–Nicolson error oscillations

DEFF Research Database (Denmark)

Britz, Dieter; Østerby, Ole; Strutwolf, J.

2003-01-01

The Crank–Nicolson (CN) simulation method has an oscillatory response to sharp initial transients. The technique is convenient but the oscillations make it less popular. Several ways of damping the oscillations in two types of electrochemical computations are investigated. For a simple one......-dimensional system with an initial singularity, subdivision of the first time interval into a number of equal subintervals (the Pearson method) works rather well, and so does division with exponentially increasing subintervals, where however an optimum expansion parameter must be found. This method can...... be computationally more expensive with some systems. The simple device of starting with one backward implicit (BI, or Laasonen) step does damp the oscillations, but not always sufficiently. For electrochemical microdisk simulations which are two-dimensional in space and using CN, the use of a first BI step is much...

Analysis of the Swift Gamma-Ray Bursts duration

International Nuclear Information System (INIS)

Horvath, I.; Veres, P.; Balazs, L. G.; Kelemen, J.; Bagoly, Z.; Tusnady, G.

2008-01-01

Two classes of gamma-ray bursts have been identified in the BATSE catalogs characterized by durations shorter and longer than about 2 seconds. There are, however, some indications for the existence of a third type of burst. Swift satellite detectors have different spectral sensitivity than pre-Swift ones for gamma-ray bursts. Therefore it is worth to reanalyze the durations and their distribution and also the classification of GRBs. Using The First BAT Catalog the maximum likelihood estimation was used to analyzed the duration distribution of GRBs. The three log-normal fit is significantly (99.54% probability) better than the two for the duration distribution. Monte-Carlo simulations also confirm this probability (99.2%).

25 CFR 211.27 - Duration of leases.

Science.gov (United States)

2010-04-01

... duration shall be measured from the date of approval by the Secretary. (b) An oil and gas or geothermal... duration without actual production of oil, gas, or geothermal resources. Provided, that this extension does... drilling is continued with reasonable diligence until the well is completed to production or abandoned...

14 CFR 1203.407 - Duration of classification.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Duration of classification. 1203.407... PROGRAM Guides for Original Classification § 1203.407 Duration of classification. (a) Information shall be... date or event for declassification shall be set by the original classification authority at the time...

5 CFR 831.642 - Marriage duration requirements.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Marriage duration requirements. 831.642... REGULATIONS (CONTINUED) RETIREMENT Survivor Annuities Eligibility § 831.642 Marriage duration requirements. (a... in paragraph (b) of this section; or (2) A child was born of the marriage, as explained in paragraph...

Duration estimates within a modality are integrated sub-optimally

Directory of Open Access Journals (Sweden)

Ming Bo eCai

2015-08-01

Full Text Available Perceived duration can be influenced by various properties of sensory stimuli. For example, visual stimuli of higher temporal frequency are perceived to last longer than those of lower temporal frequency. How does the brain form a representation of duration when each of two simultaneously presented stimuli influences perceived duration in different way? To answer this question, we investigated the perceived duration of a pair of dynamic visual stimuli of different temporal frequencies in comparison to that of a single visual stimulus of either low or high temporal frequency. We found that the duration representation of simultaneously occurring visual stimuli is best described by weighting the estimates of duration based on each individual stimulus. However, the weighting performance deviates from the prediction of statistically optimal integration. In addition, we provided a Bayesian account to explain a difference in the apparent sensitivity of the psychometric curves introduced by the order in which the two stimuli are displayed in a two-alternative forced-choice task.

Excessive daytime sleepiness, nocturnal sleep duration and ...

African Journals Online (AJOL)

Background and objectives. Short nocturnal sleep duration resulting in sleep debt may be a cause of excessive daytime sleepiness (EDS). Severity of depression (psychopathology) has been found to be directly related to EDS. There is an association between sleep duration and mental health, so there may therefore be an ...

5 CFR 843.303 - Marriage duration requirements.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Marriage duration requirements. 843.303... Former Spouse Benefits § 843.303 Marriage duration requirements. (a) The current spouse of a retiree, an... marriage, as explained in paragraph (c) of this section; or (3) The death of the retiree, employee, or...

Being a reflective teacher——reflection on group management

Institute of Scientific and Technical Information of China (English)

Pan; Lehui

2015-01-01

<正>Introduction According to Pollard and Triggs(1997),reflective teaching is a process through which the capacity to make such professional judgments can be developed and maintained.Then what is a reflective teacher?Reflective teacher is someone who reflects systematically on her practice in a constant attempt to improve

20 CFR 336.2 - Duration of normal unemployment benefits.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Duration of normal unemployment benefits. 336... UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL AND EXTENDED BENEFITS Normal Benefits § 336.2 Duration of normal unemployment benefits. (a) 130 compensable day limitation. A qualified employee who has satisfied the waiting...

The impact of attention on judgments of frequency and duration.

Directory of Open Access Journals (Sweden)

Isabell Winkler

Full Text Available Previous studies that examined human judgments of frequency and duration found an asymmetrical relationship: While frequency judgments were quite accurate and independent of stimulus duration, duration judgments were highly dependent upon stimulus frequency. A potential explanation for these findings is that the asymmetry is moderated by the amount of attention directed to the stimuli. In the current experiment, participants' attention was manipulated in two ways: (a intrinsically, by varying the type and arousal potential of the stimuli (names, low-arousal and high-arousal pictures, and (b extrinsically, by varying the physical effort participants expended during the stimulus presentation (by lifting a dumbbell vs. relaxing the arm. Participants processed stimuli with varying presentation frequencies and durations and were subsequently asked to estimate the frequency and duration of each stimulus. Sensitivity to duration increased for pictures in general, especially when processed under physical effort. A large effect of stimulus frequency on duration judgments was obtained for all experimental conditions, but a similar large effect of presentation duration on frequency judgments emerged only in the conditions that could be expected to draw high amounts of attention to the stimuli: when pictures were judged under high physical effort. Almost no difference in the mutual impact of frequency and duration was obtained for low-arousal or high-arousal pictures. The mechanisms underlying the simultaneous processing of frequency and duration are discussed with respect to existing models derived from animal research. Options for the extension of such models to human processing of frequency and duration are suggested.

The impact of attention on judgments of frequency and duration.

Science.gov (United States)

Winkler, Isabell; Glauer, Madlen; Betsch, Tilmann; Sedlmeier, Peter

2015-01-01

Previous studies that examined human judgments of frequency and duration found an asymmetrical relationship: While frequency judgments were quite accurate and independent of stimulus duration, duration judgments were highly dependent upon stimulus frequency. A potential explanation for these findings is that the asymmetry is moderated by the amount of attention directed to the stimuli. In the current experiment, participants' attention was manipulated in two ways: (a) intrinsically, by varying the type and arousal potential of the stimuli (names, low-arousal and high-arousal pictures), and (b) extrinsically, by varying the physical effort participants expended during the stimulus presentation (by lifting a dumbbell vs. relaxing the arm). Participants processed stimuli with varying presentation frequencies and durations and were subsequently asked to estimate the frequency and duration of each stimulus. Sensitivity to duration increased for pictures in general, especially when processed under physical effort. A large effect of stimulus frequency on duration judgments was obtained for all experimental conditions, but a similar large effect of presentation duration on frequency judgments emerged only in the conditions that could be expected to draw high amounts of attention to the stimuli: when pictures were judged under high physical effort. Almost no difference in the mutual impact of frequency and duration was obtained for low-arousal or high-arousal pictures. The mechanisms underlying the simultaneous processing of frequency and duration are discussed with respect to existing models derived from animal research. Options for the extension of such models to human processing of frequency and duration are suggested.

Observed and Unobserved Heterogeneity in the Duration Dependency Parameter

DEFF Research Database (Denmark)

Rosholm, Michael

2000-01-01

We present a duration model, which allows for non-homogenous duration dependence with respect to observed and unobserved variables. The model is examined in a simulation study, and it is estimated on unemployment spells of a sample of Danish workers. Udgivelsesdato: MAR......We present a duration model, which allows for non-homogenous duration dependence with respect to observed and unobserved variables. The model is examined in a simulation study, and it is estimated on unemployment spells of a sample of Danish workers. Udgivelsesdato: MAR...

A Jump Diffusion Model for Volatility and Duration

DEFF Research Database (Denmark)

Wei, Wei; Pelletier, Denis

by the market microstructure theory. Traditional measures of volatility do not utilize durations. I adopt a jump diffusion process to model the persistence of intraday volatility and conditional duration, and their interdependence. The jump component is disentangled from the continuous part of the price......, volatility and conditional duration process. I develop a MCMC algorithm for the inference of irregularly spaced multivariate process with jumps. The algorithm provides smoothed estimates of the latent variables such as spot volatility, jump times and jump sizes. I apply this model to IBM data and I find...... meaningful relationship between volatility and conditional duration. Also, jumps play an important role in the total variation, but the jump variation is smaller than traditional measures that use returns sampled at lower frequency....

Short sleep duration and large variability in sleep duration are independently associated with dietary risk factors for obesity in Danish school children

DEFF Research Database (Denmark)

Kjeldsen, J S; Hjorth, M F; Andersen, Rikke

2014-01-01

Background:Lack of sleep and increased consumption of energy-dense foods and sugar-sweetened beverages (SSB) have all been suggested as factors contributing to the increased prevalence of overweight and obesity.Objective:To evaluate whether objectively measured sleep duration (average and day......-to-day variability) as well as parent-reported sleep problems are independently associated with proposed dietary risk factors for overweight and obesity in 8-11 year old children.Design:In this cross-sectional study data on sleep duration and day-to-day variability in sleep duration were measured in 676 Danish...... and ethnicity).Conclusion:Our study suggests that short sleep duration, high sleep duration variability, and experiencing sleep problems are all associated with a poor, obesity-promoting diet in children.International Journal of Obesity accepted article preview online, 8 August 2013. doi:10.1038/ijo.2013.147....

Associations between sleep duration, sleep quality and diabetic retinopathy.

Directory of Open Access Journals (Sweden)

Nicholas Y Q Tan

Full Text Available Abnormal durations of sleep have been associated with risk of diabetes. However, it is not clear if sleep duration is associated with diabetic retinopathy (DR.In a cross-sectional study, we included 1,231 (Malay, n = 395; Indian, n = 836 adults (mean age 64.4 ± 9.0 years, 50.4% female with diabetes from the second visit of two independent population-based cohort studies (2011-15 in Singapore. Self-reported habitual sleep duration was categorized as short (<6 h, normal (6≤ h <8, and long (≥8 h. Questionnaires were administered to detect risk of obstructive sleep apnea (OSA, excessive daytime sleepiness, and insomnia, all of which may indicate poor quality of sleep. The associations between sleep-related characteristics with moderate DR and vision-threatening DR (VTDR were analysed using logistic regression models adjusted for potential confounders.Prevalence of moderate DR and VTDR in the study population were 10.5% and 6.3% respectively. The mean duration of sleep was 6.4 ± 1.5 h. Compared to normal sleep duration, both short and long sleep durations were associated with moderate DR with multivariable odds ratio (95% confidence interval of 1.73 (1.03-2.89 and 2.17 (1.28-3.66 respectively. Long sleep duration (2.37 [1.16-4.89], high risk of OSA (2.24 [1.09-4.75], and excessive daytime sleepiness (3.27 [1.02-10.30] were separately associated with VTDR.Sleep duration had a U-shaped association with moderate DR; long sleep duration, excessive daytime sleepiness and high risk of OSA were positively associated with VTDR.

Szegö Kernels and Asymptotic Expansions for Legendre Polynomials

Directory of Open Access Journals (Sweden)

Roberto Paoletti

2017-01-01

Full Text Available We present a geometric approach to the asymptotics of the Legendre polynomials Pk,n+1, based on the Szegö kernel of the Fermat quadric hypersurface, leading to complete asymptotic expansions holding on expanding subintervals of [-1,1].

Duration of Load Effects on Different Sized Timber Beams

DEFF Research Database (Denmark)

Andreasen, Lotte; Hoffmeyer, Preben

1997-01-01

This is the final report submitted to EC in connection with a project on duration of load. The report contains the results of the experimental work on duration of load for beams and notched beams of LVL and of glulam. The report also contains experimental results from duration of load experiments...

Breastfeeding duration and associated factors between 1960 and 2000

Directory of Open Access Journals (Sweden)

Danielle Soares de Oliveira

Full Text Available Abstract Objective: To describe a historical series on the median duration of breastfeeding in a population of mothers whose children were born from the 1960s onwards, identifying factors associated with the interruption of breastfeeding in each decade. Methods: Data were analyzed from the Pró-Saúde Study, a longitudinal epidemiological investigation started in 1999 among technical and administrative employees of a university in the state of Rio de Janeiro. Breastfeeding duration was collected in two study phases: Phase 1 (1999, and phase 4 (2011-2012. Of these, those who had at least one child and reported the duration of breastfeeding for the first child were selected (n = 1539. To analyze the duration of breastfeeding, survival curves were constructed using the Kaplan-Meier method and the effect of covariates on the duration of breastfeeding was estimated by Cox regression model. Results: It was found that the median duration of breastfeeding was higher in the 1990s and 2000s and lower in the 1970s, compared to the 1960s. In addition, there was an association between higher income and maternal age with breastfeeding interruption, which was focused in the 1970s. Conclusion: There was shorter duration of breastfeeding in the 1970s compared to the 1960s. Increased duration and prevalence of breastfeeding from the 1970s onwards coincided with the national trend and the promotion of this practice since 1980.

Magnitude and duration of stretch modulate fibroblast remodeling.

Science.gov (United States)

Balestrini, Jenna L; Billiar, Kristen L

2009-05-01

Mechanical cues modulate fibroblast tractional forces and remodeling of extracellular matrix in healthy tissue, healing wounds, and engineered matrices. The goal of the present study is to establish dose-response relationships between stretch parameters (magnitude and duration per day) and matrix remodeling metrics (compaction, strength, extensibility, collagen content, contraction, and cellularity). Cyclic equibiaxial stretch of 2-16% was applied to fibroblast-populated fibrin gels for either 6 h or 24 h/day for 8 days. Trends in matrix remodeling metrics as a function of stretch magnitude and duration were analyzed using regression analysis. The compaction and ultimate tensile strength of the tissues increased in a dose-dependent manner with increasing stretch magnitude, yet remained unaffected by the duration in which they were cycled (6 h/day versus 24 h/day). Collagen density increased exponentially as a function of both the magnitude and duration of stretch, with samples stretched for the reduced duration per day having the highest levels of collagen accumulation. Cell number and failure tension were also dependent on both the magnitude and duration of stretch, although stretch-induced increases in these metrics were only present in the samples loaded for 6 h/day. Our results indicate that both the magnitude and the duration per day of stretch are critical parameters in modulating fibroblast remodeling of the extracellular matrix, and that these two factors regulate different aspects of this remodeling. These findings move us one step closer to fully characterizing culture conditions for tissue equivalents, developing improved wound healing treatments and understanding tissue responses to changes in mechanical environments during growth, repair, and disease states.

BRIEF COMMUNICATIONS: Strong reflection of a series of pulses from a four-wave mirror with thermal nonlinearity under parametric feedback conditions

Science.gov (United States)

Barashkov, M. S.; Bel'dyugin, Igor'M.; Zolotarev, M. V.; Kruzhilin, Yu I.; Krymskiĭ, M. I.; Oshkin, S. P.; Starkov, G. S.; Umnov, A. F.; Kharchenko, M. A.

1989-04-01

A four-wave mirror exhibiting a thermal nonlinearity was used in a study of the interaction of concurrent waves under parametric feedback conditions in the presence of a nonreciprocal element. Strong reflection of a series of pulses of ~ 300 ns duration from a neodymium glass laser was demonstrated: the maximum reflection coefficient was in excess of 30. An analysis was made of the quality of the radiation reflected from this four-mirror parametric feedback system. A considerable reduction was observed in the steady-state threshold for the operation of this mirror with a thermal nonlinearity when the angles of convergence of the interacting beams were small compared with the case of head-on collision of the waves.

Associations between insomnia, sleep duration and poor work ability.

Science.gov (United States)

Lian, Yulong; Xiao, Jing; Liu, Yan; Ning, Li; Guan, Suzhen; Ge, Hua; Li, Fuye; Liu, Jiwen

2015-01-01

The aim of this study was to examine the independent and joint effect of insomnia and objective sleep duration on poor work ability. In this cross-sectional study, a total of 2820 Chinese manufacturing workers were categorized as insomnia patients and individuals with normal sleeping pattern by interview according to DSM-IV criteria. Sleep duration was classified into four categories: ≥7h, 6-7h, 5-6h, and Work ability was assessed using the Chinese Work Ability Index (WAI) questionnaire. Regression analysis examined the independent and joint association of sleep duration and insomnia with poor work ability, after adjusting for various confounding factors. Insomnia and objective short sleep duration were both independently associated with poor work ability. Compared with the normal sleeping and ≥7h sleep duration group, the highest risk of poor work ability was in the insomnia patients with work ability. Objective sleep duration should be taken into consideration when assessing the work ability of people with insomnia. Copyright © 2014 Elsevier Inc. All rights reserved.

Learning from clinical placement experience: Analysing nursing students' final reflections in a digital storytelling activity.

Science.gov (United States)

Paliadelis, Penny; Wood, Pamela

2016-09-01

This paper reports on the learning potential of a reflective activity undertaken by final year nursing students, in which they were asked to recount two meaningful events that occurred during their clinical placements over the duration of their 3-year nursing degree program and reflect on how these events contributed to their learning to become beginning level Registered Nurses (RNs). This descriptive qualitative study gathered narratives from 92 students as individual postings in an online forum created within the University's learning management system. An analysis of the students' reflections are the focus of this paper particularly in relation to the value of reflecting on the identified events. Four themes emerged that clearly highlight the way in which these students interpreted and learned from both positive and negative clinical experiences, their strong desire to fit into their new role and their ability to re-imagine how they might respond to clinical events when they become Registered Nurses. The findings of this study may contribute to developing nursing curricula that better prepares final year students for the realities of practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

20 CFR 625.7 - Disaster Unemployment Assistance: Duration.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Disaster Unemployment Assistance: Duration... DISASTER UNEMPLOYMENT ASSISTANCE § 625.7 Disaster Unemployment Assistance: Duration. DUA shall be payable... unemployment which begin during a Disaster Assistance Period. ...

Differential Changes in QTc Duration during In-Hospital Haloperidol Use

Science.gov (United States)

Blom, Marieke T.; Bardai, Abdennasser; van Munster, Barbara C.; Nieuwland, Mei-Ing; de Jong, Hendrik; van Hoeijen, Daniel A.; Spanjaart, Anne M.; de Boer, Anthonius; de Rooij, Sophia E.; Tan, Hanno L.

2011-01-01

Aims To evaluate changes in QT duration during low-dose haloperidol use, and determine associations between clinical variables and potentially dangerous QT prolongation. Methods In a retrospective cohort study in a tertiary university teaching hospital in The Netherlands, all 1788 patients receiving haloperidol between 2005 and 2007 were studied; ninety-seven were suitable for final analysis. Rate-corrected QT duration (QTc) was measured before, during and after haloperidol use. Clinical variables before haloperidol use and at the time of each ECG recording were retrieved from hospital charts. Mixed model analysis was used to estimate changes in QT duration. Risk factors for potentially dangerous QT prolongation were estimated by logistic regression analysis. Results Patients with normal before-haloperidol QTc duration (male ≤430 ms, female ≤450 ms) had a significant increase in QTc duration of 23 ms during haloperidol use; twenty-three percent of patients rose to abnormal levels (male ≥450 ms, female ≥470 ms). In contrast, a significant decrease occurred in patients with borderline (male 430–450 ms, female 450–470 ms) or abnormal before-haloperidol QTc duration (15 ms and 46 ms, respectively); twenty-three percent of patients in the borderline group, and only 9% of patients in the abnormal group obtained abnormal levels. Potentially dangerous QTc prolongation was independently associated with surgery before haloperidol use (ORadj 34.9, p = 0.009) and before-haloperidol QTc duration (ORadj 0.94, p = 0.004). Conclusion QTc duration during haloperidol use changes differentially, increasing in patients with normal before-haloperidol QTc duration, but decreasing in patients with prolonged before-haloperidol QTc duration. Shorter before-haloperidol QTc duration and surgery before haloperidol use predict potentially dangerous QTc prolongation. PMID:21961030

Association between sleep duration and blood pressure in adolescents.

Science.gov (United States)

Paciência, Inês; Barros, Henrique; Araújo, Joana; Ramos, Elisabete

2013-08-01

In adults, sleep has an important role in the development of cardiovascular diseases. However, in young adolescents, the effect is unclear. The purpose of this cross-sectional study was to evaluate the association between sleep duration and blood pressure (BP) in subjects of 13 years of age. We evaluated 1771 adolescents as part of a population-based cohort (Epidemiological Health Investigation of Teenagers). Sleep duration was estimated based on the difference between self-reported usual bedtimes and wake-up times, and adolescents were classified into three categories: 8.5 h (reference class), >8.5 h and sleep duration, the odds ratios (ORs) and 95% confidence intervals (95% CIs) were computed by fitting binary logistic regression models with adjustments for caffeine intake and depressive symptoms in females and for caffeine intake and sports activities in males. The mean (s.d.) sleep duration was 9.0 (0.80) h per day. The prevalence of high BP was 32.5%, higher in males (35.3%) than in females (30.1%, P=0.019). After adjustment, in females, a positive association was found between sleep duration and high BP (>8.5 and sleep duration and BP. Sleep duration was positively associated with BP in both sexes, although after adjustment for potential confounders, this association was significant only for female adolescents.

Modulating action duration to establish non-conventional communication

DEFF Research Database (Denmark)

Vesper, Cordula; Schmitz, Laura; Knoblich, Günther

2017-01-01

communication. The current study investigated whether systematic modulations of action duration provide a sufficient basis for communication. The results of three experiments demonstrate that knowledgeable actors spontaneously and systematically adjusted the duration of their actions to communicate task...

Reflective photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Lentine, Anthony L.; Nielson, Gregory N.; Cruz-Campa, Jose Luis; Okandan, Murat; Goeke, Ronald S.

2018-03-06

A photovoltaic module includes colorized reflective photovoltaic cells that act as pixels. The colorized reflective photovoltaic cells are arranged so that reflections from the photovoltaic cells or pixels visually combine into an image on the photovoltaic module. The colorized photovoltaic cell or pixel is composed of a set of 100 to 256 base color sub-pixel reflective segments or sub-pixels. The color of each pixel is determined by the combination of base color sub-pixels forming the pixel. As a result, each pixel can have a wide variety of colors using a set of base colors, which are created, from sub-pixel reflective segments having standard film thicknesses.

A New Method for Start-up of Isolated Boost Converters Using Magnetic- and Winding-Integration

DEFF Research Database (Denmark)

Lindberg-Poulsen, Kristian; Ouyang, Ziwei; Sen, Gökhan

2012-01-01

. The traditional added flyback winding coupled to the boost inductor is thus eliminated from the circuit, bringing substantial cost savings, increased efficiency and simplified design. Each subinterval of the converter operation is described through electrical and magnetic circuit diagrams, and the concept...

Duration of load revisited

DEFF Research Database (Denmark)

Hoffmeyer, Preben; Sørensen, John Dalsgaard

2007-01-01

A duration of load study representing 13 years of testing was recently terminated. Preliminary results have been published over the years. This paper represents the final account of the study, which was focused on the influ-ence of moisture content on time to failure for structural timber subject...

Expressing Intervals in Automated Service Negotiation

Science.gov (United States)

Clark, Kassidy P.; Warnier, Martijn; van Splunter, Sander; Brazier, Frances M. T.

During automated negotiation of services between autonomous agents, utility functions are used to evaluate the terms of negotiation. These terms often include intervals of values which are prone to misinterpretation. It is often unclear if an interval embodies a continuum of real numbers or a subset of natural numbers. Furthermore, it is often unclear if an agent is expected to choose only one value, multiple values, a sub-interval or even multiple sub-intervals. Additional semantics are needed to clarify these issues. Normally, these semantics are stored in a domain ontology. However, ontologies are typically domain specific and static in nature. For dynamic environments, in which autonomous agents negotiate resources whose attributes and relationships change rapidly, semantics should be made explicit in the service negotiation. This paper identifies issues that are prone to misinterpretation and proposes a notation for expressing intervals. This notation is illustrated using an example in WS-Agreement.

Statistical analysis of random duration times

International Nuclear Information System (INIS)

Engelhardt, M.E.

1996-04-01

This report presents basic statistical methods for analyzing data obtained by observing random time durations. It gives nonparametric estimates of the cumulative distribution function, reliability function and cumulative hazard function. These results can be applied with either complete or censored data. Several models which are commonly used with time data are discussed, and methods for model checking and goodness-of-fit tests are discussed. Maximum likelihood estimates and confidence limits are given for the various models considered. Some results for situations where repeated durations such as repairable systems are also discussed

Associated Information Increases Subjective Perception of Duration.

Science.gov (United States)

Schweitzer, Richard; Trapp, Sabrina; Bar, Moshe

2017-08-01

Our sense of time is prone to various biases. For instance, one factor that can dilate an event's perceived duration is the violation of predictions; when a series of repeated stimuli is interrupted by an unpredictable oddball. On the other hand, when the probability of a repetition itself is manipulated, predictable conditions can also increase estimated duration. This suggests that manipulations of expectations have different or even opposing effects on time perception. In previous studies, expectations were generated because stimuli were repeated or because the likelihood of a sequence or a repetition was varied. In the natural environment, however, expectations are often built via associative processes, for example, the context of a kitchen promotes the expectation of plates, appliances, and other associated objects. Here, we manipulated such association-based expectations by using oddballs that were either contextually associated or nonassociated with the standard items. We find that duration was more strongly overestimated for contextually associated oddballs. We reason that top-down attention is biased toward associated information, and thereby dilates subjective duration for associated oddballs. Based on this finding, we propose an interplay between top-down attention and predictive processing in the perception of time.

Effect of caffeine on prospective and retrospective duration judgements.

Science.gov (United States)

Gruber, Ronald P; Block, Richard A

2003-07-01

The effects of caffeine on prospective and retrospective duration judgements were evaluated in a double-blind placebo-controlled experiment. After taking either 200 mg caffeine or a placebo, participants touched a 17-sided polygon for 15 s. Then they verbally estimated the number of angles and the duration. Participants in the prospective group were told in advance they would be making a duration estimate, whereas those in the retrospective group were not told. Caffeine reduced duration estimates in the prospective condition but not in the retrospective condition. The effect of caffeine on very long duration comparisons (the past year compared with a year at one-half and one-quarter of one's age) was also evaluated, but none was found. The findings do not support the hypothesis that caffeine affects duration experience by increasing the internal clock rate as a result of its dopamine D(2) agonist properties. The hypothesis that caffeine produces its effect by enhancing memory was considered and rejected. The most parsimonious explanation is that caffeine increased arousal level, which led to a narrowing of the focus of attention to the most salient task. Copyright 2003 John Wiley & Sons, Ltd.

Relationship between coronal holes and high speed streams at L1: arrival times, durations, and intensities

Science.gov (United States)

Luo, B.; Bu, X.; Liu, S.; Gong, J.

2017-12-01

Coronal holes are sources of high-speed steams (HSS) of solar wind. When coronal holes appear at mid/low latitudes on the Sun, consequential HSSs may impact Earth and cause recurrent geospace environment disturbances, such as geomagnetic storms, relativistic electron enhancements at the geosynchronous orbit, and thermosphere density enhancements. Thus, it is of interests for space weather forecasters to predict when (arrival times), how long (time durations), and how severe (intensities) HSSs may impact Earth when they notice coronal holes on the sun and are anticipating their geoeffectiveness. In this study, relationship between coronal holes and high speed streams will be statistically investigated. Several coronal hole parameters, including passage times of solar central meridian, coronal hole longitudinal widths, intensities reflected by mean brightness, are derived using Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images for years 2011 to 2016. These parameters will be correlated with in-situ solar wind measurements measured at the L1 point by the ACE spacecraft, which can give some results that are useful for space weather forecaster in predicting the arrival times, durations, and intensities of coronal hole high-speed streams in about 3 days advance.

Reflection of an electromagnetic pulse from a subcritical waveguide taper and from a supercritical-density plasma in a waveguide

International Nuclear Information System (INIS)

Rukhadze, Anri A; Tarakanov, V P

2006-01-01

Two related problems are studied by numerical simulations using the KARAT code: the reflection of the TM 01 mode of an electromagnetic pulse from the subcritical taper of the section of a circular waveguide and the reflection of the same pulse from a 'cold' collisionless plasma with a density increasing up to a supercritical value along the waveguide axis. It is shown that in the former case the pulse is totally reflected with an insignificant distortion of its shape, in accordance with the linear theory. In the latter case, the character of reflection depends substantially on the plasma density increase length, the pulse duration, and the wave field amplitude, a significant field deceleration and amplitude growth occurring near the critical point; the pulse absorption in the plasma far exceeds the absorption due to the linear transformation of the incident transverse wave to the longitudinal plasma oscillations. (laser applications and other topics in quantum electronics)

Shortened duration of untreated first episode of psychosis

DEFF Research Database (Denmark)

Larsen, Tor Ketil; McGlashan, T H; Johannessen, Jan Olav

2001-01-01

OBJECTIVE: This study examined whether duration of untreated psychosis can be shortened in patients with first episodes of DSM-IV schizophrenia spectrum disorders and whether shorted duration alters patient appearance at treatment. METHOD: Two study groups were ascertained in the same Norwegian h...

Association between sleep duration and overweight: the importance of parenting.

NARCIS (Netherlands)

de Jong, E.; Stocks, T.; Visscher, T.L.S.; Hira Sing, R.A.; Seidell, J.C.; Renders, C.M.

2012-01-01

Objective:Sleep duration has been related to overweight in children, but determinants of sleep duration are unclear. The aims were to investigate the association between sleep duration and childhood overweight adjusted for family characteristics and unhealthy behaviours, to explore determinants of

Measuring Chemotherapy Appointment Duration and Variation Using Real-Time Location Systems.

Science.gov (United States)

Barysauskas, Constance M; Hudgins, Gina; Gill, Katie Kupferberg; Camuso, Kristen M; Bagley, Janet; Rozanski, Sheila; Kadish, Sarah

Clinical schedules drive resource utilization, cost, and patient wait time. Accurate appointment duration allocation ensures appropriate staffing ratios to daily caseloads and maximizes scarce resources. Dana-Farber Cancer Institute (DFCI) infusion appointment duration is adjusted by regimen using a consensus method of experts including pharmacists, nurses, and administrators. Using real-time location system (RTLS), we examined the accuracy of observed appointment duration compared with the scheduled duration. Appointment duration was calculated using RTLS at DFCI between August 1, 2013, and September 30, 2013. Duration was defined as the total time a patient occupied an infusion chair. The top 10 administered infusion regimens were investigated (n = 805). Median observed appointment durations were statistically different than the scheduled durations. Appointment durations were shorter than scheduled 98% (C), 95% (I), and 75% (F) of the time and longer than scheduled 77% (A) and 76% (G) of the time. Fifty-six percent of the longer than scheduled (A) appointments were at least 30 minute longer. RTLS provides reliable and unbiased data to improve schedule accuracy. Replacing consensus with system-based data may improve clinic flow, relieve staff stress, and increase patient satisfaction. Further investigation is warranted to elucidate factors that impact variation in appointment duration.

Duration Calculus: Logical Foundations

DEFF Research Database (Denmark)

Hansen, Michael Reichhardt; Chaochen, Zhou

1997-01-01

The Duration Calculus (abbreviated DC) represents a logical approach to formal design of real-time systems, where real numbers are used to model time and Boolean valued functions over time are used to model states and events of real-time systems. Since it introduction, DC has been applied to many...

Implications on visual apperception: energy, duration, structure and synchronization.

Science.gov (United States)

Bókkon, I; Vimal, Ram Lakhan Pandey

2010-07-01

Although primary visual cortex (V1 or striate) activity per se is not sufficient for visual apperception (normal conscious visual experiences and conscious functions such as detection, discrimination, and recognition), the same is also true for extrastriate visual areas (such as V2, V3, V4/V8/VO, V5/M5/MST, IT, and GF). In the lack of V1 area, visual signals can still reach several extrastriate parts but appear incapable of generating normal conscious visual experiences. It is scarcely emphasized in the scientific literature that conscious perceptions and representations must have also essential energetic conditions. These energetic conditions are achieved by spatiotemporal networks of dynamic mitochondrial distributions inside neurons. However, the highest density of neurons in neocortex (number of neurons per degree of visual angle) devoted to representing the visual field is found in retinotopic V1. It means that the highest mitochondrial (energetic) activity can be achieved in mitochondrial cytochrome oxidase-rich V1 areas. Thus, V1 bear the highest energy allocation for visual representation. In addition, the conscious perceptions also demand structural conditions, presence of adequate duration of information representation, and synchronized neural processes and/or 'interactive hierarchical structuralism.' For visual apperception, various visual areas are involved depending on context such as stimulus characteristics such as color, form/shape, motion, and other features. Here, we focus primarily on V1 where specific mitochondrial-rich retinotopic structures are found; we will concisely discuss V2 where smaller riches of these structures are found. We also point out that residual brain states are not fully reflected in active neural patterns after visual perception. Namely, after visual perception, subliminal residual states are not being reflected in passive neural recording techniques, but require active stimulation to be revealed.

Partnership duration, concurrency, and HIV in sub-Saharan Africa.

Science.gov (United States)

Sawers, Larry; Isaac, Alan

2017-07-01

A widely accepted explanation for the exceptionally high HIV prevalence in sub-Saharan Africa is the practice of long-term overlapping heterosexual partnering. This article shows that long-duration concurrent partnering can be protective against HIV transmission rather than promoting it. Monogamous partnering prevents sexual transmission to anyone outside the partnership and, in an initially concordant-seronegative partnership, prevents sexual acquisition of HIV by either partner. Those protections against transmission and acquisition last as long as the partnership persists without new outside partnerships. Correspondingly, these two protective effects characterise polygynous partnerships, whether or not the polygyny is formal or informal, until a partner initiates a new partnership. Stable and exclusive unions of any size protect against HIV transmission, and more durable unions provide a longer protective effect. Survey research provides little information on partnership duration in sub-Saharan Africa and sheds no light on the interaction of duration, concurrency, and HIV. This article shows how assumptions about partnership duration in individual-based sexual-network models affect the contours of simulated HIV epidemics. Longer mean partnership duration slows the pace at which simulated epidemics grow. With plausible assumptions about partnership duration and at levels of concurrency found in the region, simulated HIV epidemics grow slowly or not at all. Those results are consistent with the hypothesis that long-duration partnering is protective against HIV and inconsistent with the hypothesis that long-term concurrency drives the HIV epidemics in sub-Saharan Africa.

Human responses to bright light of different durations.

Science.gov (United States)

Chang, Anne-Marie; Santhi, Nayantara; St Hilaire, Melissa; Gronfier, Claude; Bradstreet, Dayna S; Duffy, Jeanne F; Lockley, Steven W; Kronauer, Richard E; Czeisler, Charles A

2012-07-01

Light exposure in the early night induces phase delays of the circadian rhythm in melatonin in humans. Previous studies have investigated the effect of timing, intensity, wavelength, history and pattern of light stimuli on the human circadian timing system. We present results from a study of the duration–response relationship to phase-delaying bright light. Thirty-nine young healthy participants (16 female; 22.18±3.62 years) completed a 9-day inpatient study. Following three baseline days, participants underwent an initial circadian phase assessment procedure in dim light (light pulse (∼10,000 lux) of 0.2 h, 1.0 h, 2.5 h or 4.0 h duration during a 4.5 h controlled-posture episode centred in a 16 h wake episode. After another 8 h sleep episode, participants completed a second circadian phase assessment. Phase shifts were calculated from the difference in the clock time of the dim light melatonin onset (DLMO) between the initial and final phase assessments. Exposure to varying durations of bright light reset the circadian pacemaker in a dose-dependent, non-linear manner. Per minute of exposure, the 0.2 h duration was over 5 times more effective at phase delaying the circadian pacemaker (1.07±0.36 h) as compared with the 4.0 h duration (2.65±0.24 h). Acute melatonin suppression and subjective sleepiness also had a dose-dependent response to light exposure duration. These results provide strong evidence for a non-linear resetting response of the human circadian pacemaker to light duration.

Drought Duration Biases in Current Global Climate Models

Science.gov (United States)

Moon, Heewon; Gudmundsson, Lukas; Seneviratne, Sonia

2016-04-01

Several droughts in the recent past are characterized by their increased duration and intensity. In particular, substantially prolonged droughts have brought major societal and economic losses in certain regions, yet climate change projections of such droughts in terms of duration is subject to large uncertainties. This study analyzes the biases of drought duration in state-of-the-art global climate model (GCM) simulations from the 5th phase of Coupled Model Intercomparison Project (CMIP5). Drought durations are defined as negative precipitation anomalies and evaluated with three observation-based datasets in the period of 1901-2010. Large spread in biases of GCMs is commonly found in all regions, with particular strong biases in North East Brazil, Africa, Northern Australia, Central America, Central and Northern Europe, Sahel and Asia. Also in most regions, the interquartile range of bias lies below 0, meaning that the GCMs tend to underestimate drought durations. Meanwhile in some regions such as Western South America, the Amazon, Sahel, West and South Africa, and Asia, considerable inconsistency among the three observation-based datasets were found. These results indicate substantial uncertainties and errors in current GCMs for simulating drought durations as well as a large spread in observation-based datasets, both of which are found to be particularly strong in those regions that are often considered to be hot spots of projected future drying. The underlying sources of these uncertainties need to be identified in further study and will be applied to constrain GCM-based drought projections under climate change.

Factors associated with sleep duration in Brazilian high school students.

Science.gov (United States)

Gomes Felden, Érico Pereira; Barbosa, Diego Grasel; Junior, Geraldo Jose Ferrari; Santos, Manoella De Oliveira; Pelegrini, Andreia; Silva, Diego Augusto Santos

2017-01-01

The aim of this study was to investigate the factors associated with short sleep duration on southern Brazilian high school students. Our study was comprised of 1,132 adolescents aged 14 to 19 years, enrolled in public high schools in São José, Brazil. The students answered a questionnaire about working (work and workload), health perception, smoking, school schedule, sleep (duration and daytime sleepiness), and socio-demographics data. The results showed that more than two thirds of adolescent workers had short sleep duration (76.7%), and those with a higher workload (more than 20 hours) had a shorter sleep duration (7.07 hours) compared to non-workers (7.83 hours). In the analysis of factors associated with short sleep duration, adolescents who worked (OR = 2.12, 95% CI 1.53 to 2.95) were more likely to have short sleep duration compared to those who did not work. In addition, older adolescents (17-19 years) and students with poor sleep quality were 40% and 55% more likely to have short sleep duration compared to younger adolescents (14-16 years) and students with good sleep quality, respectively. Adolescents with daytime sleepiness were more likely to have short sleep duration (OR = 1.49, 95% CI 1.06 to 2.07) compared to those without excessive daytime sleepiness. In addition students of the morning shift (OR = 6.02, 95% CI 4.23 to 8.57) and evening shift (OR = 2.16, 95% CI 1.45 to 3.22) were more likely to have short sleep duration compared to adolescents of the afternoon shift. Thereby adolescents who are workers, older, attended morning and evening classes and have excessive daytime sleepiness showed risk factors for short sleep duration. In this sense, it is pointed out the importance of raising awareness of these risk factors for short sleep duration of students from public schools from São José, located in southern Brazil.

Surface sterilization and duration of seed storage influenced ...

African Journals Online (AJOL)

The effects of factorial combinations of four storage duration (in days after seed extraction) and surface sterilization with three dilution levels of sodium hypochlorite on seedling emergence and seedling quality of African breadfruit were studied. Storage duration significantly influenced days to seedling emergence, ...

Illusory conjunctions of pitch and duration in unfamiliar tone sequences.

Science.gov (United States)

Thompson, W F; Hall, M D; Pressing, J

2001-02-01

In 3 experiments, the authors examined short-term memory for pitch and duration in unfamiliar tone sequences. Participants were presented a target sequence consisting of 2 tones (Experiment 1) or 7 tones (Experiments 2 and 3) and then a probe tone. Participants indicated whether the probe tone matched 1 of the target tones in both pitch and duration. Error rates were relatively low if the probe tone matched 1 of the target tones or if it differed from target tones in pitch, duration, or both. Error rates were remarkably high, however, if the probe tone combined the pitch of 1 target tone with the duration of a different target tone. The results suggest that illusory conjunctions of these dimensions frequently occur. A mathematical model is presented that accounts for the relative contribution of pitch errors, duration errors, and illusory conjunctions of pitch and duration.

Association between sleep duration and overweight: the importance of parenting.

Science.gov (United States)

de Jong, E; Stocks, T; Visscher, T L S; HiraSing, R A; Seidell, J C; Renders, C M

2012-10-01

Sleep duration has been related to overweight in children, but determinants of sleep duration are unclear. The aims were to investigate the association between sleep duration and childhood overweight adjusted for family characteristics and unhealthy behaviours, to explore determinants of sleep duration and to determine with sleep competing activities. A cross-sectional study was carried out in 2006 among 4072 children aged 4-13 years in the city of Zwolle, The Netherlands. In these children, data were available on measured height, weight and waist circumference, and from a parental questionnaire, on socio-demographic characteristics, child's sleep duration, nutrition, physical activity and sedentary behaviour. Associations were studied in 2011 using logistic and linear regression analyses, adjusted for potential confounders. Short sleep duration was associated with overweight for 4-8-year-old boys (odds ratio (OR):3.10; 95% confidence interval (CI):1.15-8.40), 9-13-year-old boys (OR:4.96; 95% CI:1.35-18.16) and 9-13-year-old girls (OR:4.86; 95% CI:1.59-14.88). Among 4-8-year-old girls no statistically significant association was found. Determinants for short sleep duration were viewing television during a meal, permission to have candy without asking, not being active with their caregiver and a late bedtime. For all children, short sleep duration was strongly associated with more television viewing and computer use. Association between sleep duration and overweight is not explained by socio-demographic variables, drinking sugared drinks and eating snacks. Parents have a key role in stimulating optimal sleep duration. Improving parenting skills and knowledge to offer children more structure, and possibly with that, increase sleeping hours, may be promising in prevention of overweight.

Optical observations of Magnetosphere-Ionosphere coupling: Inter-hemispheric electron reflections within pulsating aurora

Science.gov (United States)

Samara, M.; Michell, R.; Khazanov, G. V.; Grubbs, G. A., II

2017-12-01

Magnetosphere-Ionosphere coupling is exhibited in reflected primary and secondary electrons which constitute the second step in the formation of the total precipitating electron distribution. While they have largely been missing from the current theoretical studies of particle precipitation, ground based observations point to the existence of a reflected electron population. We present evidence that pulsating aurora is caused by electrons bouncing back and forth between the two hemispheres. This means that these electrons are responsible for some of the total light in the aurora, a possibility that has largely been ignored in theoretical models. Pulsating auroral events imaged optically at high time resolution present direct observational evidence in agreement with the inter-hemispheric electron bouncing predicted by the SuperThermal Electron Trans-port (STET) model. Immediately following each of the `pulsation-on' times are equally spaced, and subsequently fainter pulsations, which can be explained by the primary precipitating electrons reflecting upwards from the ionosphere, traveling to the opposite hemisphere, and reflecting upwards again. The high time-resolution of these data, combined with the short duration of the `pulsation-on' time ( 1 s) and the relatively long spacing between pulsations ( 6 to 9 s) made it possible to observe the faint optical pulses caused by the reflected electrons coming from the opposite hemisphere. These results are significant and have broad implications because they highlight that the formation of the auroral electron distributions within regions of diffuse and pulsating aurora contain contributions from reflected primary and secondary electrons. These processes can ultimately lead to larger fluxes than expected when considering only the primary injection of magnetospheric electrons.

Study on the preheating duration of Cu{sub 2}SnS{sub 3} thin films using RF magnetron sputtering technique for photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Dong, Yuchen; He, Jun; Li, Xinran; Chen, Ye; Sun, Lin, E-mail: lsun@ee.ecnu.edu.cn; Yang, Pingxiong; Chu, Junhao

2016-04-25

Cu{sub 2}SnS{sub 3} (CTS) thin films are prepared by sulfurization the stacked metallic precursors deposited by raido-frequency magnetron sputtering method on molybdenum-coated soda lime glass substrates. The details of sulfurization process and the effect of preheating duration on the properties of CTS thin films have been investigated. It is found that the content of element tin strongly depend on the preheating duration. X-ray diffraction patterns identify that the CTS thin films exhibit the monoclinic structure. Raman scattering spectra make a further confirmation for the crystal structure. Fourier transform infrared reflectance spectroscopy (FTIR) is first used to study the properties of CTS thin films. The assigned active modes in Raman scattering spectra is consistent with the analysis in FTIR. Morphology analysis reveals long preheating duration would make the quality of films deteriorate. The thin film solar cell (TFSC) fabricated using the CTS absorber layer synthesized at preheating duration of 15 min shows that a power conversion efficiency up to 0.76% for a 0.19 cm{sup 2} area. The electrical characterization of CTS TFSC is first studied by electrochemical impedance spectroscopy, which implies the existence of MoS{sub x} and defects in the CTS/CdS interface. - Highlights: • CTS thin films and solar cells prepared by RF magnetron sputtering. • Preheating duration is a critical way to remain the Sn content in CTS thin film. • XRD, Raman, FTIR and XPS confirmed the single phase of CTS thin film. • The device characterization of CTS solar cell has been systematically investigated.

Expectation, information processing, and subjective duration.

Science.gov (United States)

Simchy-Gross, Rhimmon; Margulis, Elizabeth Hellmuth

2018-01-01

In research on psychological time, it is important to examine the subjective duration of entire stimulus sequences, such as those produced by music (Teki, Frontiers in Neuroscience, 10, 2016). Yet research on the temporal oddball illusion (according to which oddball stimuli seem longer than standard stimuli of the same duration) has examined only the subjective duration of single events contained within sequences, not the subjective duration of sequences themselves. Does the finding that oddballs seem longer than standards translate to entire sequences, such that entire sequences that contain oddballs seem longer than those that do not? Is this potential translation influenced by the mode of information processing-whether people are engaged in direct or indirect temporal processing? Two experiments aimed to answer both questions using different manipulations of information processing. In both experiments, musical sequences either did or did not contain oddballs (auditory sliding tones). To manipulate information processing, we varied the task (Experiment 1), the sequence event structure (Experiments 1 and 2), and the sequence familiarity (Experiment 2) independently within subjects. Overall, in both experiments, the sequences that contained oddballs seemed shorter than those that did not when people were engaged in direct temporal processing, but longer when people were engaged in indirect temporal processing. These findings support the dual-process contingency model of time estimation (Zakay, Attention, Perception & Psychophysics, 54, 656-664, 1993). Theoretical implications for attention-based and memory-based models of time estimation, the pacemaker accumulator and coding efficiency hypotheses of time perception, and dynamic attending theory are discussed.

Duration-frequency relationships of heavy rainfall in Santa Catarina, Brazil

Directory of Open Access Journals (Sweden)

Álvaro José Back

2012-06-01

Full Text Available The purpose of this study was to adjust equations that establish relationships between rainfall events with different duration and data from weather stations in the state of Santa Catarina, Brazil. In this study, the relationships between different duration heavy rainfalls from 13 weather stations of Santa Catarina were analyzed. From series of maximum annual rainfalls, and using the Gumbel-Chow distribution, the maximum rainfall for durations between 5 min and 24 h were estimated considering return periods from 2 to 100 years. The data fit to the Gumbel-Chow model was verified by the Kolmogorov-Smirnov test at 5 % significance. The coefficients of Bell's equation were adjusted to estimate the relationship between rainfall duration t (min and the return period T (y in relation to the maximum rainfall with a duration of 1 hour and a 10 year return period. Likewise, the coefficients of Bell's equation were adjusted based on the maximum rainfall with a duration of 1 day and a 10 year return period. The results showed that these relationships are viable to estimate short-duration rainfall events at locations where there are no rainfall records.

Separate representation of stimulus frequency, intensity, and duration in auditory sensory memory: an event-related potential and dipole-model analysis.

Science.gov (United States)

Giard, M H; Lavikahen, J; Reinikainen, K; Perrin, F; Bertrand, O; Pernier, J; Näätänen, R

1995-01-01

Abstract The present study analyzed the neural correlates of acoustic stimulus representation in echoic sensory memory. The neural traces of auditory sensory memory were indirectly studied by using the mismatch negativity (MMN), an event-related potential component elicited by a change in a repetitive sound. The MMN is assumed to reflect change detection in a comparison process between the sensory input from a deviant stimulus and the neural representation of repetitive stimuli in echoic memory. The scalp topographies of the MMNs elicited by pure tones deviating from standard tones by either frequency, intensity, or duration varied according to the type of stimulus deviance, indicating that the MMNs for different attributes originate, at least in part, from distinct neural populations in the auditory cortex. This result was supported by dipole-model analysis. If the MMN generator process occurs where the stimulus information is stored, these findings strongly suggest that the frequency, intensity, and duration of acoustic stimuli have a separate neural representation in sensory memory.

Quantifying Reflection

DEFF Research Database (Denmark)

Alcock, Gordon Lindsay

2013-01-01

´ These are all based on Blooms taxonomy and levels of competence and form a major part of individual student and group learning portfolios. Key Words :Project-Based learning, Reflective Portfolios, Self assessment, Defining learning gains, Developing learning strategies , Reflections on and for learning....... It contrasts the students’ self-assessment in a range of ‘product’ skills such as Revit, Structural Design, Mathematics of construction, Technical Installations; as well as ‘process’ competencies such as ‘Working in a team’, Sharing knowledge, Maintaining a portfolio and Reflecting ON learning and FOR learning......This paper documents 1st semester student reflections on “learning to learn” in a team-based PBL environment with quantitative and qualitative student reflective feedback on the learning gains of 60 Architectural Technology and Construction Management students at VIA University College, Denmark...

Temperature-reflection I

DEFF Research Database (Denmark)

McGady, David A.

2017-01-01

-temperature path integrals for quantum field theories (QFTs) should be T-reflection invariant. Because multi-particle partition functions are equal to Euclidean path integrals for QFTs, we expect them to be T-reflection invariant. Single-particle partition functions though are often not invariant under T......In this paper, we revisit the claim that many partition functions are invariant under reflecting temperatures to negative values (T-reflection). The goal of this paper is to demarcate which partition functions should be invariant under T-reflection, and why. Our main claim is that finite...... that T-reflection is unrelated to time-reversal. Finally, we study the interplay between T-reflection and perturbation theory in the anharmonic harmonic oscillator in quantum mechanics and in Yang-Mills in four-dimensions. This is the first in a series of papers on temperature-reflections....

40 CFR 40.125-1 - Limitations on duration.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Limitations on duration. 40.125-1 Section 40.125-1 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE RESEARCH AND DEMONSTRATION GRANTS § 40.125-1 Limitations on duration. (a) [Reserved] (b) No...

Time-order errors and standard-position effects in duration discrimination: An experimental study and an analysis by the sensation-weighting model.

Science.gov (United States)

Hellström, Åke; Rammsayer, Thomas H

2015-10-01

Studies have shown that the discriminability of successive time intervals depends on the presentation order of the standard (St) and the comparison (Co) stimuli. Also, this order affects the point of subjective equality. The first effect is here called the standard-position effect (SPE); the latter is known as the time-order error. In the present study, we investigated how these two effects vary across interval types and standard durations, using Hellström's sensation-weighting model to describe the results and relate them to stimulus comparison mechanisms. In Experiment 1, four modes of interval presentation were used, factorially combining interval type (filled, empty) and sensory modality (auditory, visual). For each mode, two presentation orders (St-Co, Co-St) and two standard durations (100 ms, 1,000 ms) were used; half of the participants received correctness feedback, and half of them did not. The interstimulus interval was 900 ms. The SPEs were negative (i.e., a smaller difference limen for St-Co than for Co-St), except for the filled-auditory and empty-visual 100-ms standards, for which a positive effect was obtained. In Experiment 2, duration discrimination was investigated for filled auditory intervals with four standards between 100 and 1,000 ms, an interstimulus interval of 900 ms, and no feedback. Standard duration interacted with presentation order, here yielding SPEs that were negative for standards of 100 and 1,000 ms, but positive for 215 and 464 ms. Our findings indicate that the SPE can be positive as well as negative, depending on the interval type and standard duration, reflecting the relative weighting of the stimulus information, as is described by the sensation-weighting model.

Auditory cortical and hippocampal-system mismatch responses to duration deviants in urethane-anesthetized rats.

Directory of Open Access Journals (Sweden)

Timo Ruusuvirta

Full Text Available Any change in the invariant aspects of the auditory environment is of potential importance. The human brain preattentively or automatically detects such changes. The mismatch negativity (MMN of event-related potentials (ERPs reflects this initial stage of auditory change detection. The origin of MMN is held to be cortical. The hippocampus is associated with a later generated P3a of ERPs reflecting involuntarily attention switches towards auditory changes that are high in magnitude. The evidence for this cortico-hippocampal dichotomy is scarce, however. To shed further light on this issue, auditory cortical and hippocampal-system (CA1, dentate gyrus, subiculum local-field potentials were recorded in urethane-anesthetized rats. A rare tone in duration (deviant was interspersed with a repeated tone (standard. Two standard-to-standard (SSI and standard-to-deviant (SDI intervals (200 ms vs. 500 ms were applied in different combinations to vary the observability of responses resembling MMN (mismatch responses. Mismatch responses were observed at 51.5-89 ms with the 500-ms SSI coupled with the 200-ms SDI but not with the three remaining combinations. Most importantly, the responses appeared in both the auditory-cortical and hippocampal locations. The findings suggest that the hippocampus may play a role in (cortical manifestation of MMN.

Mitochondrial DNA Copy Number in Sleep Duration Discordant Monozygotic Twins.

Science.gov (United States)

Wrede, Joanna E; Mengel-From, Jonas; Buchwald, Dedra; Vitiello, Michael V; Bamshad, Michael; Noonan, Carolyn; Christiansen, Lene; Christensen, Kaare; Watson, Nathaniel F

2015-10-01

Mitochondrial DNA (mtDNA) copy number is an important component of mitochondrial function and varies with age, disease, and environmental factors. We aimed to determine whether mtDNA copy number varies with habitual differences in sleep duration within pairs of monozygotic twins. Academic clinical research center. 15 sleep duration discordant monozygotic twin pairs (30 twins, 80% female; mean age 42.1 years [SD 15.0]). Sleep duration was phenotyped with wrist actigraphy. Each twin pair included a "normal" (7-9 h/24) and "short" (sleeping twin. Fasting peripheral blood leukocyte DNA was assessed for mtDNA copy number via the n-fold difference between qPCR measured mtDNA and nuclear DNA creating an mtDNA measure without absolute units. We used generalized estimating equation linear regression models accounting for the correlated data structure to assess within-pair effects of sleep duration on mtDNA copy number. Mean within-pair sleep duration difference per 24 hours was 94.3 minutes (SD 62.6 min). We found reduced sleep duration (β = 0.06; 95% CI 0.004, 0.12; P sleep efficiency (β = 0.51; 95% CI 0.06, 0.95; P sleep duration was associated with a decrease in mtDNA copy number of 0.06. Likewise, a 1% decrease in actigraphy-defined sleep efficiency was associated with a decrease in mtDNA copy number of 0.51. Reduced sleep duration and sleep efficiency were associated with reduced mitochondrial DNA copy number in sleep duration discordant monozygotic twins offering a potential mechanism whereby short sleep impairs health and longevity through mitochondrial stress. © 2015 Associated Professional Sleep Societies, LLC.

Rhythm-based heartbeat duration normalization for atrial fibrillation detection.

Science.gov (United States)

Islam, Md Saiful; Ammour, Nassim; Alajlan, Naif; Aboalsamh, Hatim

2016-05-01

Screening of atrial fibrillation (AF) for high-risk patients including all patients aged 65 years and older is important for prevention of risk of stroke. Different technologies such as modified blood pressure monitor, single lead ECG-based finger-probe, and smart phone using plethysmogram signal have been emerging for this purpose. All these technologies use irregularity of heartbeat duration as a feature for AF detection. We have investigated a normalization method of heartbeat duration for improved AF detection. AF is an arrhythmia in which heartbeat duration generally becomes irregularly irregular. From a window of heartbeat duration, we estimate the possible rhythm of the majority of heartbeats and normalize duration of all heartbeats in the window based on the rhythm so that we can measure the irregularity of heartbeats for both AF and non-AF rhythms in the same scale. Irregularity is measured by the entropy of distribution of the normalized duration. Then we classify a window of heartbeats as AF or non-AF by thresholding the measured irregularity. The effect of this normalization is evaluated by comparing AF detection performances using duration with the normalization, without normalization, and with other existing normalizations. Sensitivity and specificity of AF detection using normalized heartbeat duration were tested on two landmark databases available online and compared with results of other methods (with/without normalization) by receiver operating characteristic (ROC) curves. ROC analysis showed that the normalization was able to improve the performance of AF detection and it was consistent for a wide range of sensitivity and specificity for use of different thresholds. Detection accuracy was also computed for equal rates of sensitivity and specificity for different methods. Using normalized heartbeat duration, we obtained 96.38% accuracy which is more than 4% improvement compared to AF detection without normalization. The proposed normalization

10 CFR 451.6 - Duration of incentive payments.

Science.gov (United States)

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Duration of incentive payments. 451.6 Section 451.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION RENEWABLE ENERGY PRODUCTION INCENTIVES § 451.6 Duration of incentive... part with respect to a qualified renewable energy facility for 10 consecutive fiscal years. Such period...

Syllable Durations of Preword and Early Word Vocalizations.

Science.gov (United States)

Robb, Michael P.; Saxman, John H.

1990-01-01

The continuity in development of syllable duration patterns was examined in seven young children as they progressed from preword to multiword periods of vocalization development. Results revealed no systematic increase or decrease in the duration of bisyllables produced by the children as a group, whereas lengthening of final syllables was…

Theory of reflection reflection and transmission of electromagnetic, particle and acoustic waves

CERN Document Server

Lekner, John

2016-01-01

This book deals with the reflection of electromagnetic and particle waves by interfaces. The interfaces can be sharp or diffuse. The topics of the book contain absorption, inverse problems, anisotropy, pulses and finite beams, rough surfaces, matrix methods, numerical methods,  reflection of particle waves and neutron reflection. Exact general results are presented, followed by long wave reflection, variational theory, reflection amplitude equations of the Riccati type, and reflection of short waves. The Second Edition of the Theory of Reflection is an updated and much enlarged revision of the 1987 monograph. There are new chapters on periodically stratified media, ellipsometry, chiral media, neutron reflection and reflection of acoustic waves. The chapter on anisotropy is much extended, with a complete treatment of the reflection and transmission properties of arbitrarily oriented uniaxial crystals. The book gives a systematic and unified treatment reflection and transmission of electromagnetic and particle...

Cultivating Reflective Practitioners in Technology Preparation: Constructing TPACK through Reflection

Directory of Open Access Journals (Sweden)

Liangyue Lu

2013-12-01

Full Text Available Teaching is a complex profession, which is further complicated by the integration of technology into classrooms. Reflection can help teachers unpack the complexity in their practice. Reflection can be an effective instructional strategy in helping preservice teachers develop technological pedagogical content knowledge (TPACK, the complex and dynamic knowledge necessary for effective technology integration into instruction. In this study, reflective activities were integrated into a Learning By Design (LBD environment, which was created to help preservice teachers develop TPACK. This paper investigated the participants’ TPACK development and examined how reflection helped them construct TPACK. Through content analysis of the participants’ reflective journals, the researcher found that the preservice teachers developed initial TPACK awareness. However, their reflection in technology knowledge and the content aspects of TPACK were limited and superficial. Interviews with the participants showed reflection helped the preservice teachers remember what they learned by describing and elaborating on their in-class experiences, pushed them to think about how to apply what they learned in their future classrooms, and helped them become more reflective and open-minded about using technology in classrooms. Finally, the researcher discussed this study’s implications for teacher educators and researchers.

Rethinking non-inferiority: a practical trial design for optimising treatment duration.

Science.gov (United States)

Quartagno, Matteo; Walker, A Sarah; Carpenter, James R; Phillips, Patrick Pj; Parmar, Mahesh Kb

2018-06-01

Background Trials to identify the minimal effective treatment duration are needed in different therapeutic areas, including bacterial infections, tuberculosis and hepatitis C. However, standard non-inferiority designs have several limitations, including arbitrariness of non-inferiority margins, choice of research arms and very large sample sizes. Methods We recast the problem of finding an appropriate non-inferior treatment duration in terms of modelling the entire duration-response curve within a pre-specified range. We propose a multi-arm randomised trial design, allocating patients to different treatment durations. We use fractional polynomials and spline-based methods to flexibly model the duration-response curve. We call this a 'Durations design'. We compare different methods in terms of a scaled version of the area between true and estimated prediction curves. We evaluate sensitivity to key design parameters, including sample size, number and position of arms. Results A total sample size of ~ 500 patients divided into a moderate number of equidistant arms (5-7) is sufficient to estimate the duration-response curve within a 5% error margin in 95% of the simulations. Fractional polynomials provide similar or better results than spline-based methods in most scenarios. Conclusion Our proposed practical randomised trial 'Durations design' shows promising performance in the estimation of the duration-response curve; subject to a pending careful investigation of its inferential properties, it provides a potential alternative to standard non-inferiority designs, avoiding many of their limitations, and yet being fairly robust to different possible duration-response curves. The trial outcome is the whole duration-response curve, which may be used by clinicians and policymakers to make informed decisions, facilitating a move away from a forced binary hypothesis testing paradigm.

Duration of coming life associated with disablement owing to ophthalmothology

Directory of Open Access Journals (Sweden)

N. M. Rustamova

2014-07-01

Full Text Available It was conducted the comparison of the middle duration of coming life associated with disablement owing to the different groups of eye disease in work. The difference between the duration of coming life of country population and the patient’ age were used as the gauge of life duration associated with disablement at the moment of the primary recognition by an invalid. It was determined that the middle duration of coming life associated with disablement changed and shook in the groups from 11,31 to 36,37 years for men and from 17,58 to 42,37 years for women subject to the reason of disablement. It is considered that the middle duration of coming life associated with disablement is integral criterion for an estimation of the medico-social burden of disease. It is differed 3 degrees of heaviness of the medico-social burden. The moderate heaviness of the medico-social burden (the middle duration of coming lif associated with disablement less than 20 years is characteristic for diabetic retinopathy, glaucoma and uveitis and the high degree of heaviness (the middle duration of coming life associated with disablement more than 30 years for disease of eyeball, visual nerve, eye traumas, myopia and anophthalmia.

Duration of coming life associated with disablement owing to ophthalmothology

Directory of Open Access Journals (Sweden)

N. M. Rustamova

2013-01-01

Full Text Available It was conducted the comparison of the middle duration of coming life associated with disablement owing to the different groups of eye disease in work. The difference between the duration of coming life of country population and the patient’ age were used as the gauge of life duration associated with disablement at the moment of the primary recognition by an invalid. It was determined that the middle duration of coming life associated with disablement changed and shook in the groups from 11,31 to 36,37 years for men and from 17,58 to 42,37 years for women subject to the reason of disablement. It is considered that the middle duration of coming life associated with disablement is integral criterion for an estimation of the medico-social burden of disease. It is differed 3 degrees of heaviness of the medico-social burden. The moderate heaviness of the medico-social burden (the middle duration of coming lif associated with disablement less than 20 years is characteristic for diabetic retinopathy, glaucoma and uveitis and the high degree of heaviness (the middle duration of coming life associated with disablement more than 30 years for disease of eyeball, visual nerve, eye traumas, myopia and anophthalmia.

Single-electron transport driven by surface acoustic waves: Moving quantum dots versus short barriers

DEFF Research Database (Denmark)

Utko, Pawel; Hansen, Jørn Bindslev; Lindelof, Poul Erik

2007-01-01

We have investigated the response of the acoustoelectric-current driven by a surface-acoustic wave through a quantum point contact in the closed-channel regime. Under proper conditions, the current develops plateaus at integer multiples of ef when the frequency f of the surface-acoustic wave...... or the gate voltage V-g of the point contact is varied. A pronounced 1.1 MHz beat period of the current indicates that the interference of the surface-acoustic wave with reflected waves matters. This is supported by the results obtained after a second independent beam of surface-acoustic wave was added......, traveling in opposite direction. We have found that two sub-intervals can be distinguished within the 1.1 MHz modulation period, where two different sets of plateaus dominate the acoustoelectric-current versus gate-voltage characteristics. In some cases, both types of quantized steps appeared simultaneously...

40 CFR 166.45 - Duration of crisis exemption.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Duration of crisis exemption. 166.45... EXEMPTION OF FEDERAL AND STATE AGENCIES FOR USE OF PESTICIDES UNDER EMERGENCY CONDITIONS Crisis Exemptions § 166.45 Duration of crisis exemption. A crisis exemption may be authorized for: (a) Only as long as is...

Modeling Spatial Dependence of Rainfall Extremes Across Multiple Durations

Science.gov (United States)

Le, Phuong Dong; Leonard, Michael; Westra, Seth

2018-03-01

Determining the probability of a flood event in a catchment given that another flood has occurred in a nearby catchment is useful in the design of infrastructure such as road networks that have multiple river crossings. These conditional flood probabilities can be estimated by calculating conditional probabilities of extreme rainfall and then transforming rainfall to runoff through a hydrologic model. Each catchment's hydrological response times are unlikely to be the same, so in order to estimate these conditional probabilities one must consider the dependence of extreme rainfall both across space and across critical storm durations. To represent these types of dependence, this study proposes a new approach for combining extreme rainfall across different durations within a spatial extreme value model using max-stable process theory. This is achieved in a stepwise manner. The first step defines a set of common parameters for the marginal distributions across multiple durations. The parameters are then spatially interpolated to develop a spatial field. Storm-level dependence is represented through the max-stable process for rainfall extremes across different durations. The dependence model shows a reasonable fit between the observed pairwise extremal coefficients and the theoretical pairwise extremal coefficient function across all durations. The study demonstrates how the approach can be applied to develop conditional maps of the return period and return level across different durations.

In-Hospital Haloperidol Use and Perioperative Changes in QTc-Duration.

Science.gov (United States)

Blom, M T; Jansen, S; de Jonghe, A; van Munster, B C; de Boer, A; de Rooij, S E; Tan, H L; van der Velde, N

2015-05-01

Haloperidol may prolong ECG QTc-duration but is often prescribed perioperatively to hip-fracture patients. We aimed to determine (1) how QTc-duration changes perioperatively, (2) whether low-dose haloperidol-use influences these changes, and (3) which clinical variables are associated with potentially dangerous perioperative QTc-prolongation (PD-QTc; increase >50 ms or to >500 ms). Prospective cohort study. Tertiary university teaching-hospital. Patients enrolled in a randomized controlled clinical trial of melatonin versus placebo on occurrence of delirium in hip-fracture patients. Data from ECGs made before and after hip surgery (1-3 days and/or 4-6 days post-surgery) were analyzed. QTc-duration was measured by hand, blinded for haloperidol and pre/post-surgery status. Clinical variables were measured at baseline. Mixed model analysis was used to estimate changes in QTc-duration. Risk-factors for PD-QTc were estimated by logistic regression analysis. We included 89 patients (mean age 84 years, 24% male); 39 were treated with haloperidol. Patients with normal pre-surgery QTc-duration (male ≤430 ms, female ≤450 ms) had a significant increase (mean 12 ms, SD 28) in QTc-duration. A significant decrease (mean 19 ms, SD 34) occurred in patients with prolonged pre-surgery QTc-duration (male >450ms, female >470 ms). Haloperidol-use did not influence the perioperative course of the QTc-interval (p=0.351). PD-QTc (n=8) was not associated with any of the measured risk-factors. QTc-duration changed differentially, increasing in patients with normal, but decreasing in patients with abnormal baseline QTc-duration. PD-QTc was not associated with haloperidol-use or other risk-factors. Low-dose oral haloperidol did not affect perioperative QTc-interval.

Limit Stress Spline Models for GRP Composites | Ihueze | Nigerian ...

African Journals Online (AJOL)

Spline functions were established on the assumption of three intervals and fitting of quadratic and cubic splines to critical stress-strain responses data. Quadratic ... of data points. Spline model is therefore recommended as it evaluates the function at subintervals, eliminating the error associated with wide range interpolation.

Reflecting on reflection in interprofessional education: implications for theory and practice.

Science.gov (United States)

Clark, Phillip G

2009-05-01

Interprofessional education (IPE) involves learning, and learning requires reflection. Educators need to "reflect more on reflection" if they are to be effective teachers in ensuring the learning outcomes essential for teamwork and interprofessional practice (IPP), including incorporating both theory and practice into the development of educational interventions. First, this discussion surveys the IPE-relevant literature on reflection, and then defines and refines the multidimensional concept of reflection as it relates to IPE in developing and implementing teamwork learning programs and experiences. Second, specific methods to promote reflection are presented and explored, including self-assessments, journaling, and written papers. Actual samples from student journals and assignments provide examples of the impacts of using these methods on participant reflection and learning. Finally, implications for an expanded understanding and application of reflection for IPE will be discussed, and recommendations made for educational practice and research in this area.

Background music as a quasi clock in retrospective duration judgments.

Science.gov (United States)

Bailey, Nicole; Areni, Charles S

2006-04-01

The segmentation-change model of time perception proposes that individuals engaged in cognitive tasks during a given interval of time retrospectively estimate duration by recalling events that occurred during the interval and inferring each event's duration. Previous research suggests that individuals can recall the number of songs heard during an interval and infer the length of each song, exactly the conditions that foster estimates of duration based on the segmentation-change model. The results of a laboratory experiment indicated that subjects who solved word-search puzzles for 20 min. estimated the duration of the interval to be longer when 8 short songs (background, regardless of whether the musical format was Contemporary Dance or New Age. Assuming each song represented a distinct segment in memory, these results are consistent with the segmentation-change model. These results suggest that background music may not always reduce estimates of duration by drawing attention away from the passage of time. Instead, background music may actually expand the subjective length of an interval by creating accessible traces in memory, which are retrospectively used to infer duration.

[Sleep duration among school-age children in Hungary and Romania].

Science.gov (United States)

Sólyom, Réka; Lendvai, Zsófia; Pásti, Krisztina; Szeifert, Lilla; Szabó, J Attila

2013-10-06

Children's sleep duration is decreasing in the last decade. Despite of the well known negative consequences, there are no data on children's sleep duration in Hungary and Romania. The aim of the authors was to assess sleep duration of school-age children in Hungary and Romania. A self-edited questionnaire was used for the study. 2446 children were enrolled. All elementary and secondary schools in a Hungarian city, and one elementary and secondary school in a Romanian city took part in the study. Mean sleep duration was 8.3 ± 1.2 hours on weekdays. There was a significant difference between the two countries (Hungary vs. Romania, 8.5 ± 1.2 hours vs. 7.8 ± 0.9 hours, p = 0.001). Age correlated with sleep duration on weekdays (r= -0.605, p = 0.001), but not during weekend. This is the first study on children's sleep duration in Hungary and Romania. The difference between countries may be due to the difference in mean age or cultural and/or geographical differences.

20 CFR 410.213 - Duration of entitlement; child.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Duration of entitlement; child. 410.213...; Filing of Claims and Evidence § 410.213 Duration of entitlement; child. (a) An individual is entitled to benefits as a child for each month beginning with the first month in which all of the conditions of...

Nonlocal multi-scale traffic flow models: analysis beyond vector spaces

Directory of Open Access Journals (Sweden)

Peter E. Kloeden

2016-08-01

Full Text Available Abstract Realistic models of traffic flow are nonlinear and involve nonlocal effects in balance laws. Flow characteristics of different types of vehicles, such as cars and trucks, need to be described differently. Two alternatives are used here, $$L^p$$ L p -valued Lebesgue measurable density functions and signed Radon measures. The resulting solution spaces are metric spaces that do not have a linear structure, so the usual convenient methods of functional analysis are no longer applicable. Instead ideas from mutational analysis will be used, in particular the method of Euler compactness will be applied to establish the well-posedness of the nonlocal balance laws. This involves the concatenation of solutions of piecewise linear systems on successive time subintervals obtained by freezing the nonlinear nonlocal coefficients to their values at the start of each subinterval. Various compactness criteria lead to a convergent subsequence. Careful estimates of the linear systems are needed to implement this program.

Risk-Sensitive Multiagent Decision-Theoretic Planning Based on MDP and One-Switch Utility Functions

Directory of Open Access Journals (Sweden)

Wei Zeng

2014-01-01

Full Text Available In high stakes situations decision-makers are often risk-averse and decision-making processes often take place in group settings. This paper studies multiagent decision-theoretic planning under Markov decision processes (MDPs framework with considering the change of agent’s risk attitude as his wealth level varies. Based on one-switch utility function that describes agent’s risk attitude change with his wealth level, we give the additive and multiplicative aggregation models of group utility and adopt maximizing expected group utility as planning objective. When the wealth level approaches infinity, the characteristics of optimal policy are analyzed for the additive and multiplicative aggregation model, respectively. Then a backward-induction method is proposed to divide the wealth level interval from negative infinity to initial wealth level into subintervals and determine the optimal policy in states and subintervals. The proposed method is illustrated by numerical examples and the influences of agent’s risk aversion parameters and weights on group decision-making are also analyzed.

The relationship between duration of psoriasis, vascular inflammation, and cardiovascular events

DEFF Research Database (Denmark)

Egeberg, Alexander; Skov, Lone; Joshi, Aditya A.

2017-01-01

of psoriasis duration [hazard ratio, 1.010; 95% confidence interval, 1.007-1.013]). Limitations These studies utilized observational data. Conclusion We found detrimental effects of psoriasis duration on vascular inflammation and MACE, suggesting that cumulative duration of exposure to low-grade chronic......Background Psoriasis is associated with risk of cardiovascular (CV) disease (CVD) and a major adverse CV event (MACE). Whether psoriasis duration affects risk of vascular inflammation and MACEs has not been well characterized. Objectives We utilized two resources to understand the effect...... of psoriasis duration on vascular disease and CV events: (1) a human imaging study and (2) a population-based study of CVD events. Methods First, patients with psoriasis (N = 190) underwent fludeoxyglucose F 18 positron emission tomography/computed tomography (duration effect reported as a β...

Examining Duration of Binge Eating Episodes in Binge Eating Disorder

Science.gov (United States)

Schreiber-Gregory, Deanna N.; Lavender, Jason M.; Engel, Scott G.; Wonderlich, Steve A.; Crosby, Ross D.; Peterson, Carol B.; Simonich, Heather; Crow, Scott; Durkin, Nora; Mitchell, James E.

2013-01-01

Objective The primary goal of this paper is to examine and clarify characteristics of binge eating in individuals with binge eating disorder (BED), particularly the duration of binge eating episodes, as well as potential differences between individuals with shorter compared to longer binge eating episodes. Method Two studies exploring binge eating characteristics in BED were conducted. Study 1 examined differences in clinical variables among individuals (N = 139) with BED who reported a short (binge duration. Study 2 utilized an ecological momentary assessment (EMA) design to examine the duration and temporal pattern of binge eating episodes in the natural environment in a separate sample of nine women with BED. Results Participants in Study 1 who were classified as having long duration binge eating episodes displayed greater symptoms of depression and lower self-esteem, but did not differ on other measures of eating disorder symptoms, compared to those with short duration binge eating episodes. In Study 2, the average binge episode duration was approximately 42 minutes, and binge eating episodes were most common during the early afternoon and evening hours, as well as more common on weekdays versus weekends. Discussion Past research on binge episode characteristics, particularly duration, has been limited to studies of binge eating episodes in BN. This study contributes to the existing literature on characteristics of binge eating in BED. PMID:23881639

Effects of Chk1 inhibition on the temporal duration of radiation-induced G2 arrest in HeLa cells

International Nuclear Information System (INIS)

Nahar, Kamrun; Goto, Tatsuaki; Kaida, Atsushi; Deguchi, Shifumi; Miura, Masahiko

2014-01-01

Chk1 inhibitor acts as a potent radiosensitizer in p53-deficient tumor cells by abrogating the G2/M check-point. However, the effects of Chk1 inhibitor on the duration of G2 arrest have not been precisely analyzed. To address this issue, we utilized a cell-cycle visualization system, fluorescent ubiquitination-based cell-cycle indicator (Fucci), to analyze the change in the first green phase duration (FGPD) after irradiation. In the Fucci system, G1 and S/G2/M cells emit red and green fluorescence, respectively; therefore, G2 arrest is reflected by an elongated FGPD. The system also allowed us to differentially analyze cells that received irradiation in the red or green phase. Cells irradiated in the green phase exhibited a significantly elongated FGPD relative to cells irradiated in the red phase. In cells irradiated in either phase, Chk1 inhibitor reduced FGPD almost to control levels. The results of this study provide the first clear information regarding the effects of Chk1 inhibition on radiation-induced G2 arrest, with special focus on the time dimension. (author)

Duration of dual antiplatelet therapy in acute coronary syndrome.

Science.gov (United States)

Wilson, Simon John; Newby, David E; Dawson, Dana; Irving, John; Berry, Colin

2017-04-01

Despite a large volume of evidence supporting the use of dual antiplatelet therapy in patients with acute coronary syndrome, there remains major uncertainty regarding the optimal duration of therapy. Clinical trials have varied markedly in the duration of therapy, both across and within trials. Recent systematic reviews and meta-analyses suggest that shorter durations of dual antiplatelet therapy are superior because the avoidance of atherothrombotic events is counterbalanced by the greater risks of excess major bleeding with apparent increases in all-cause mortality with longer durations. These findings did not show significant heterogeneity according to whether patients had stable or unstable coronary heart disease. Moreover, the potential hazards and benefits may differ when applied to the general broad population of patients encountered in everyday clinical practice who have markedly higher bleeding and atherothrombotic event rates. Clinicians lack definitive information regarding the duration of therapy in patients with acute coronary syndrome and risk scores do not appear to be sufficiently robust to address these concerns. We believe that there is a pressing need to undertake a broad inclusive safety trial of shorter durations of therapy in real world populations of patients with acute coronary syndrome. The clinical evidence would further inform future research into strategies for personalised medicine. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Incident Duration Modeling Using Flexible Parametric Hazard-Based Models

Directory of Open Access Journals (Sweden)

Ruimin Li

2014-01-01

Full Text Available Assessing and prioritizing the duration time and effects of traffic incidents on major roads present significant challenges for road network managers. This study examines the effect of numerous factors associated with various types of incidents on their duration and proposes an incident duration prediction model. Several parametric accelerated failure time hazard-based models were examined, including Weibull, log-logistic, log-normal, and generalized gamma, as well as all models with gamma heterogeneity and flexible parametric hazard-based models with freedom ranging from one to ten, by analyzing a traffic incident dataset obtained from the Incident Reporting and Dispatching System in Beijing in 2008. Results show that different factors significantly affect different incident time phases, whose best distributions were diverse. Given the best hazard-based models of each incident time phase, the prediction result can be reasonable for most incidents. The results of this study can aid traffic incident management agencies not only in implementing strategies that would reduce incident duration, and thus reduce congestion, secondary incidents, and the associated human and economic losses, but also in effectively predicting incident duration time.

Fluctuation behaviors of financial return volatility duration

Science.gov (United States)

Niu, Hongli; Wang, Jun; Lu, Yunfan

2016-04-01

It is of significantly crucial to understand the return volatility of financial markets because it helps to quantify the investment risk, optimize the portfolio, and provide a key input of option pricing models. The characteristics of isolated high volatility events above certain threshold in price fluctuations and the distributions of return intervals between these events arouse great interest in financial research. In the present work, we introduce a new concept of daily return volatility duration, which is defined as the shortest passage time when the future volatility intensity is above or below the current volatility intensity (without predefining a threshold). The statistical properties of the daily return volatility durations for seven representative stock indices from the world financial markets are investigated. Some useful and interesting empirical results of these volatility duration series about the probability distributions, memory effects and multifractal properties are obtained. These results also show that the proposed stock volatility series analysis is a meaningful and beneficial trial.

Regional flow duration curves for ungauged sites in Sicily

Directory of Open Access Journals (Sweden)

F. Viola

2011-01-01

Full Text Available Flow duration curves are simple and powerful tools to deal with many hydrological and environmental problems related to water quality assessment, water-use assessment and water allocation. Unfortunately the scarcity of streamflow data enables the use of these instruments only for gauged basins. A regional model is developed here for estimating flow duration curves at ungauged basins in Sicily, Italy. Due to the complex ephemeral behavior of the examined region, this study distinguishes dry periods, when flows are zero, from wet periods using a three parameters power law to describe the frequency distribution of flows. A large dataset of streamflows has been analyzed and the parameters of flow duration curves have been derived for about fifty basins. Regional regression equations have been developed to derive flow duration curves starting from morphological basin characteristics.

14 CFR 21.181 - Duration.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Duration. 21.181 Section 21.181 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION... those alterations performed in accordance with an applicable consensus standard and authorized by the...

Scaling in the distribution of intertrade durations of Chinese stocks

Science.gov (United States)

Jiang, Zhi-Qiang; Chen, Wei; Zhou, Wei-Xing

2008-10-01

The distribution of intertrade durations, defined as the waiting times between two consecutive transactions, is investigated based upon the limit order book data of 23 liquid Chinese stocks listed on the Shenzhen Stock Exchange in the whole year 2003. A scaling pattern is observed in the distributions of intertrade durations, where the empirical density functions of the normalized intertrade durations of all 23 stocks collapse onto a single curve. The scaling pattern is also observed in the intertrade duration distributions for filled and partially filled trades and in the conditional distributions. The ensemble distributions for all stocks are modeled by the Weibull and the Tsallis q-exponential distributions. Maximum likelihood estimation shows that the Weibull distribution outperforms the q-exponential for not-too-large intertrade durations which account for more than 98.5% of the data. Alternatively, nonlinear least-squares estimation selects the q-exponential as a better model, in which the optimization is conducted on the distance between empirical and theoretical values of the logarithmic probability densities. The distribution of intertrade durations is Weibull followed by a power-law tail with an asymptotic tail exponent close to 3.

Grain-filling duration and grain yield relationships in wheat mutants

International Nuclear Information System (INIS)

Larik, A.S.

1987-01-01

Nine stable mutants of bread wheat along with their mother cultivars were investigated for grain-filling characteristics in relation to grain yield. Significant differences among mutants for grain-filling duration and grain-filling index were observed. Inspite of the consistent differences in grain-filling duration there was no significant association between grain-filling duration and grain yield in C-591 and Nayab mutants. Failure to detect an yield advantage due to differences in grain-filling duration in these genotypes suggests that any advantage derived from alteration of grain-filling period may have been outweighed by the coincident changes in length of the vegetative period. Other factors such as synchrony of anthesis may have limited out ability to find an association between grainfilling duration and grain yield. On the contrary, significant association between grain-filling duration and grain yield displayed by indus-66 indus-66 mutants derived from gamma rays, shows the ability of gamma rays to induce functional alternations in the pattern of gene arrangements controlling these traits. Thus, the vaability observed in these physiological traits suggests that selection for these traits could be useful in improving grain yield. (author)

Effects of Word Frequency and Transitional Probability on Word Reading Durations of Younger and Older Speakers.

Science.gov (United States)

Moers, Cornelia; Meyer, Antje; Janse, Esther

2017-06-01

High-frequency units are usually processed faster than low-frequency units in language comprehension and language production. Frequency effects have been shown for words as well as word combinations. Word co-occurrence effects can be operationalized in terms of transitional probability (TP). TPs reflect how probable a word is, conditioned by its right or left neighbouring word. This corpus study investigates whether three different age groups-younger children (8-12 years), adolescents (12-18 years) and older (62-95 years) Dutch speakers-show frequency and TP context effects on spoken word durations in reading aloud, and whether age groups differ in the size of these effects. Results show consistent effects of TP on word durations for all age groups. Thus, TP seems to influence the processing of words in context, beyond the well-established effect of word frequency, across the entire age range. However, the study also indicates that age groups differ in the size of TP effects, with older adults having smaller TP effects than adolescent readers. Our results show that probabilistic reduction effects in reading aloud may at least partly stem from contextual facilitation that leads to faster reading times in skilled readers, as well as in young language learners.

Mitochondrial DNA Copy Number in Sleep Duration Discordant Monozygotic Twins

DEFF Research Database (Denmark)

Wrede, Joanna E; Mengel-From, Jonas; Buchwald, Dedra

2015-01-01

STUDY OBJECTIVES: Mitochondrial DNA (mtDNA) copy number is an important component of mitochondrial function and varies with age, disease, and environmental factors. We aimed to determine whether mtDNA copy number varies with habitual differences in sleep duration within pairs of monozygotic twins...... structure to assess within-pair effects of sleep duration on mtDNA copy number. MEASUREMENTS AND RESULTS: Mean within-pair sleep duration difference per 24 hours was 94.3 minutes (SD 62.6 min). We found reduced sleep duration (β = 0.06; 95% CI 0.004, 0.12; P sleep efficiency (β = 0.51; 95% CI 0.......06, 0.95; P DNA copy number within twin pairs. Thus every 1-minute decrease in actigraphy-defined sleep duration was associated with a decrease in mtDNA copy number of 0.06. Likewise, a 1% decrease in actigraphy-defined sleep efficiency was associated...

Cardiometabolic factors and disease duration in patients with Parkinson's disease.

Science.gov (United States)

Cassani, Erica; Cereda, Emanuele; Barichella, Michela; Madio, Carmen; Cancello, Raffaella; Caccialanza, Riccardo; Zini, Michela; Cilia, Roberto; Pezzoli, Gianni

2013-01-01

Previous studies have reported that patients with Parkinson's disease (PD) have a favorable cardiometabolic risk profile. The aim of this study was to investigate the relationship between cardiometabolic risk factors and the duration of disease. One hundred and fifty patients with PD (56.7% men) were studied, measuring body mass index (BMI), waist circumference (WC), body fat percentage (BF%) by impedance, fasting glucose, serum lipids, and transaminases. In sex- and age-adjusted correlation models, duration of PD was inversely related to BMI (r = -0.20; P HDL) levels were positively correlated with disease duration (P HDL-cholesterol ratio was also inversely associated with duration of PD (P HDL levels and total HDL-cholesterol ratio were favorably associated with duration of PD. This factor may contribute to cardiometabolic protection in PD. The mechanisms underlying this association deserve further investigation. Copyright © 2013 Elsevier Inc. All rights reserved.

Reducing the duration of untreated first-episode psychosis

DEFF Research Database (Denmark)

Melle, Ingrid; Larsen, Tor K; Haahr, Ulrik

2004-01-01

Most studies on first-episode psychosis show an association between a long duration of untreated psychosis (DUP) and poorer short-term outcome, but the mechanisms of this relationship are poorly understood.......Most studies on first-episode psychosis show an association between a long duration of untreated psychosis (DUP) and poorer short-term outcome, but the mechanisms of this relationship are poorly understood....

Particle Astrophysics in NASA's Long Duration Balloon Program

International Nuclear Information System (INIS)

Gorham, Peter W.

2013-01-01

A century after Viktor Hess' discovery of cosmic rays, balloon flights still play a central role in the investigation of cosmic rays over nearly their entire spectrum. We report on the current status of NASA balloon program for particle astrophysics, with particular emphasis on the very successful Antarctic long-duration balloon program, and new developments in the progress toward ultra-long duration balloons

New fat suppression RF pulse with shorter duration

International Nuclear Information System (INIS)

Yamaguchi, Kojiro; Ukai, Hiroyuki

2010-01-01

The fat suppression radio frequency pulse currently employed for MRI, which selectively saturates the frequency of the fat, has the narrow-band frequency characteristics. Therefore, the application duration for the pulse employed tends to be prolonged. In the present study, we designed a new fat suppression radiofrequency (RF) pulse using the Laguerre function in order to shorten the duration for fat suppression RF pulse and conducted an evaluation with the clinical equipment. The length of the RF pulse that we created allowed to reduce the duration by 47.3% compared with that employed for the clinical equipment. In addition, in the MR imaging evaluation, the new pulse was confirmed to have the fat suppression effect equivalent to that employed for the clinical equipment. (author)

Dual-Priced Modal Transition Systems with Time Durations

DEFF Research Database (Denmark)

Beneš, Nikola; Kretínsky, Jan; Larsen, Kim Guldstrand

2012-01-01

Modal transition systems are a well-established specification formalism for a high-level modelling of component-based software systems. We present a novel extension of the formalism called modal transition systems with durations where time durations are modelled as controllable or uncontrollable...... intervals. We further equip the model with two kinds of quantitative aspects: each action has its own running cost per time unit, and actions may require several hardware components of different costs. We ask the question, given a fixed budget for the hardware components, what is the implementation...... with the cheapest long-run average reward. We give an algorithm for computing such optimal implementations via a reduction to a new extension of mean payoff games with time durations and analyse the complexity of the algorithm....

Modelling the Reduction of Project Making Duration

Directory of Open Access Journals (Sweden)

Oleinik Pavel

2017-01-01

Full Text Available The article points out why earlier patterns of investment process were ineffective in developing the construction projects and shows sources for reducing of its total duration. It describes the procedure of statistical modeling and obtaining medium-term time parameters required for modern pattern of project-making; offers design formulas for assessment of total time required for project-making as well as for its main stages; reveals advantage of modern system of project-making against traditional one by comparing indicators of their duration.

Low-activity waste feed delivery -- Minimum duration between successive batches

International Nuclear Information System (INIS)

Peters, B.B.

1998-01-01

The purpose of this study is to develop a defensible basis for establishing what ''minimum duration'' will provide acceptable risk mitigation for low-activity waste feed delivery to the privatization vendors. The study establishes a probabilistic-based duration for staging of low-activity waste feed batches. A comparison is made of the durations with current feed delivery plans and potential privatization vendor facility throughput rates

Low-activity waste feed delivery -- Minimum duration between successive batches

Energy Technology Data Exchange (ETDEWEB)

Peters, B.B.

1998-08-25

The purpose of this study is to develop a defensible basis for establishing what ``minimum duration`` will provide acceptable risk mitigation for low-activity waste feed delivery to the privatization vendors. The study establishes a probabilistic-based duration for staging of low-activity waste feed batches. A comparison is made of the durations with current feed delivery plans and potential privatization vendor facility throughput rates.

Peer group reflection helps clinical teachers to critically reflect on their teaching.

Science.gov (United States)

Boerboom, Tobias B B; Jaarsma, Debbie; Dolmans, Diana H J M; Scherpbier, Albert J J A; Mastenbroek, Nicole J J M; Van Beukelen, Peter

2011-01-01

Student evaluations can help clinical teachers to reflect on their teaching skills and find ways to improve their teaching. Studies have shown that the mere presentation of student evaluations is not a sufficient incentive for teachers to critically reflect on their teaching. We evaluated and compared the effectiveness of two feedback facilitation strategies that were identical except for a peer reflection meeting. In this study, 54 clinical teachers were randomly assigned to two feedback strategies. In one strategy, a peer reflection was added as an additional step. All teachers completed a questionnaire evaluating the strategy that they had experienced. We analysed the reflection reports and the evaluation questionnaire. Both strategies stimulated teachers to reflect on feedback and formulate alternative actions for their teaching practice. The teachers who had participated in the peer reflection meeting showed deeper critical reflection and more concrete plans to change their teaching. All feedback strategies were considered effective by the majority of the teachers. Strategies with student feedback and self-assessment stimulated reflection on teaching and helped clinical teachers to formulate plans for improvement. A peer reflection meeting seemed to enhance reflection quality. Further research should establish whether it can have lasting effects on teaching quality.

Instrumental variable estimation of treatment effects for duration outcomes

NARCIS (Netherlands)

G.E. Bijwaard (Govert)

2007-01-01

textabstractIn this article we propose and implement an instrumental variable estimation procedure to obtain treatment effects on duration outcomes. The method can handle the typical complications that arise with duration data of time-varying treatment and censoring. The treatment effect we

Media for Reflection

DEFF Research Database (Denmark)

Knudsen, Morten

2016-01-01

This article develops the concept media for reflection in the interest of conceptualizing the interpretative frames that enable and limit reflection in management and leadership education. The concept ‘media for reflection’ allows us to conceptualize the social and cultural mediation of reflection...... without reducing reflection to an effect of the social structures and cultural norms in which it is embedded. Based on the developed theoretical framework, this article analyses how a renaissance ‘mirror for princes’ and contemporary research-based management education mediate reflection. The content...... of the mediations is analysed as well as the societal and organizational background. Furthermore, the means by which the two media enable and limit reflection in different ways is compared. Finally, the article discusses possible implications of the analysis in terms of management and leadership education....

The relationship between duration of psoriasis, vascular inflammation, and cardiovascular events.

Science.gov (United States)

Egeberg, Alexander; Skov, Lone; Joshi, Aditya A; Mallbris, Lotus; Gislason, Gunnar H; Wu, Jashin J; Rodante, Justin; Lerman, Joseph B; Ahlman, Mark A; Gelfand, Joel M; Mehta, Nehal N

2017-10-01

Psoriasis is associated with risk of cardiovascular (CV) disease (CVD) and a major adverse CV event (MACE). Whether psoriasis duration affects risk of vascular inflammation and MACEs has not been well characterized. We utilized two resources to understand the effect of psoriasis duration on vascular disease and CV events: (1) a human imaging study and (2) a population-based study of CVD events. First, patients with psoriasis (N = 190) underwent fludeoxyglucose F 18 positron emission tomography/computed tomography (duration effect reported as a β-coefficient). Second, MACE risk was examined by using nationwide registries (adjusted hazard ratios in patients with psoriasis (n = 87,161) versus the general population (n = 4,234,793). In the human imaging study, patients were young, of low CV risk by traditional risk scores, and had a high prevalence of cardiometabolic diseases. Vascular inflammation by fludeoxyglucose F 18 positron emission tomography/computed tomography was significantly associated with disease duration (β = 0.171, P = .002). In the population-based study, psoriasis duration had strong relationship with MACE risk (1.0% per additional year of psoriasis duration [hazard ratio, 1.010; 95% confidence interval, 1.007-1.013]). These studies utilized observational data. We found detrimental effects of psoriasis duration on vascular inflammation and MACE, suggesting that cumulative duration of exposure to low-grade chronic inflammation may accelerate vascular disease development and MACEs. Providers should consider inquiring about duration of disease to counsel for heightened CVD risk in psoriasis. Copyright © 2017 American Academy of Dermatology, Inc. All rights reserved.

Sleep duration, nap habits, and mortality in older persons.

Science.gov (United States)

Cohen-Mansfield, Jiska; Perach, Rotem

2012-07-01

To examine the effect of nighttime sleep duration on mortality and the effect modification of daytime napping on the relationship between nighttime sleep duration and mortality in older persons. Prospective survey with 20-yr mortality follow-up. The Cross-Sectional and Longitudinal Aging Study, a multidimensional assessment of a stratified random sample of the older Jewish population in Israel conducted between 1989-1992. There were 1,166 self-respondent, community-dwelling participants age 75-94 yr (mean, 83.40, standard deviation, 5.30). Nighttime sleep duration, napping, functioning (activities of daily living, instrumental activities of daily living, Orientation Memory Concentration Test), health, and mortality. Duration of nighttime sleep of more than 9 hr was significantly related to increased mortality in comparison with sleeping 7-9 hr (hazard ratio [HR] = 1.31, P habits, and mortality in older persons. SLEEP 2012;35(7):1003-1009.

Retinal arterioles narrow with increasing duration of anti-retroviral therapy in HIV infection: a novel estimator of vascular risk in HIV?

Directory of Open Access Journals (Sweden)

Sophia Pathai

Full Text Available HIV infection is associated with an increased risk of age-related morbidity mediated by immune dysfunction, atherosclerosis and inflammation. Changes in retinal vessel calibre may reflect cumulative structural damage arising from these mechanisms. The relationship of retinal vessel calibre with clinical and demographic characteristics was investigated in a population of HIV-infected individuals in South Africa.Case-control study of 491 adults ≥30 years, composed of 242 HIV-infected adults and 249 age- and gender-matched HIV-negative controls. Retinal vessel calibre was measured using computer-assisted techniques to determine mean arteriolar and venular diameters of each eye.The median age was 40 years (IQR: 35-48 years. Among HIV-infected adults, 87.1% were receiving highly active antiretroviral therapy (HAART (median duration, 58 months, their median CD4 count was 468 cells/µL, and 84.3% had undetectable plasma viral load. Unadjusted mean retinal arteriolar diameters were 163.67±17.69 µm in cases and 161.34±17.38 µm in controls (p = 0.15. Unadjusted mean venular diameters were 267.77±18.21 µm in cases and 270.81±18.98 µm in controls (p = 0.07. Age modified the effect of retinal arteriolar and venular diameters in relation to HIV status, with a tendency towards narrower retinal diameters in HIV cases but not in controls. Among cases, retinal arteriolar diameters narrowed with increasing duration of HAART, independently of age (167.83 µm 6 years, p-trend = 0.02, and with a HIV viral load >10,000 copies/mL while on HAART (p = 0.05. HIV-related venular changes were not detected.Narrowing of retinal arteriolar diameters is associated with HAART duration and viral load, and may reflect heightened inflammatory and pro-atherogenic states of the systemic vasculature. Measurement of retinal vascular calibre could be an innovative non-invasive method of estimating vascular risk in HIV-infected individuals.

Perceived duration of visual and tactile stimuli depends on perceived speed

Directory of Open Access Journals (Sweden)

Alice eTomassini

2011-09-01

Full Text Available It is known that the perceived duration of visual stimuli is strongly influenced by speed: faster moving stimuli appear to last longer. To test whether this is a general property of sensory systems we asked participants to reproduce the duration of visual and tactile gratings, and visuo-tactile gratings moving at a variable speed (3.5 – 15 cm/s for three different durations (400, 600 and 800 ms. For both modalities, the apparent duration of the stimulus increased strongly with stimulus speed, more so for tactile than for visual stimuli. In addition, visual stimuli were perceived to last approximately 200 ms longer than tactile stimuli. The apparent duration of visuo-tactile stimuli lay between the unimodal estimates, as the Bayesian account predicts, but the bimodal precision of the reproduction did not show the theoretical improvement. A cross-modal speed-matching task revealed that visual stimuli were perceived to move faster than tactile stimuli. To test whether the large difference in the perceived duration of visual and tactile stimuli resulted from the difference in their perceived speed, we repeated the time reproduction task with visual and tactile stimuli matched in apparent speed. This reduced, but did not completely eliminate the difference in apparent duration. These results show that for both vision and touch, perceived duration depends on speed, pointing to common strategies of time perception.

Estimating Drilling Cost and Duration Using Copulas Dependencies Models

Directory of Open Access Journals (Sweden)

M. Al Kindi

2017-03-01

Full Text Available Estimation of drilling budget and duration is a high-level challenge for oil and gas industry. This is due to the many uncertain activities in the drilling procedure such as material prices, overhead cost, inflation, oil prices, well type, and depth of drilling. Therefore, it is essential to consider all these uncertain variables and the nature of relationships between them. This eventually leads into the minimization of the level of uncertainty and yet makes a "good" estimation points for budget and duration given the well type. In this paper, the copula probability theory is used in order to model the dependencies between cost/duration and MRI (mechanical risk index. The MRI is a mathematical computation, which relates various drilling factors such as: water depth, measured depth, true vertical depth in addition to mud weight and horizontal displacement. In general, the value of MRI is utilized as an input for the drilling cost and duration estimations. Therefore, modeling the uncertain dependencies between MRI and both cost and duration using copulas is important. The cost and duration estimates for each well were extracted from the copula dependency model where research study simulate over 10,000 scenarios. These new estimates were later compared to the actual data in order to validate the performance of the procedure. Most of the wells show moderate - weak relationship of MRI dependence, which means that the variation in these wells can be related to MRI but to the extent that it is not the primary source.

Cognitive Assessment in Long-Duration Space Flight

Science.gov (United States)

Kane, Robert; Seaton, Kimberly; Sipes, Walter

2011-01-01

This slide presentation reviews the development and use of a tool for assessing spaceflight cognitive ability in astronauts. This tool. the Spaceflight Cognitive Assessment Tool for Windows (WinSCAT) has been used to provide ISS flight surgeons with an objective clinical tool to monitor the astronauts cognitive status during long-duration space flight and allow immediate feedback to the astronaut. Its use is medically required for all long-duration missions and it contains a battery of five cognitive assessment subtests that are scheduled monthly and compared against the individual preflight baseline.

Development of an empirical correlation for combustion durations in spark ignition engines

International Nuclear Information System (INIS)

Bayraktar, Hakan; Durgun, Orhan

2004-01-01

Development of an empirical correlation for combustion duration is presented. For this purpose, the effects of variations in compression ratio engine speed, fuel/air equivalence ratio and spark advance on combustion duration have been determined by means of a quasi-dimensional SI engine cycle model previously developed by the authors. Burn durations at several engine operating conditions were calculated from the turbulent combustion model. Variations of combustion duration with each operating parameter obtained from the theoretical results were expressed by second degree polynomial functions. By using these functions, a general empirical correlation for the burn duration has been developed. In this correlation, the effects of engine operating parameters on combustion duration were taken into account. Combustion durations predicted by means of this correlation are in good agreement with those obtained from experimental studies and a detailed combustion model

Rhythmic constraints in durational control

NARCIS (Netherlands)

Grover, C.N.; Terken, J.M.B.

1994-01-01

Two potential factors in durational control are addressed. First, we investigate whether lengthening a syllable implies lengthening all of its constituent phonemes in a regular way. Analysis of a small corpus of syllables shows that this is not the case. Second, we investigate the influence of

Rent control and unemployment duration

DEFF Research Database (Denmark)

Svarer, Michael; Rosholm, Michael; Munch, Jakob Roland

2005-01-01

In this paper we analyse how rent control affects the duration of individual unemployment. In atheoretical search model we distinguish between two effects of rent control. On one hand, rentcontrol reduces housing mobility and hence mobility in the labour market. On the other hand, tomaintain rent...

Beyond the Margins: Reflective Writing and Development of Reflective Capacity in Medical Education

Science.gov (United States)

Reis, Shmuel P.

2010-01-01

Reflective capacity has been described as an essential characteristic of professionally competent clinical practice, core to ACGME competencies. Reflection has been recently linked to promoting effective use of feedback in medical education and associated with improved diagnostic accuracy, suggesting promising outcomes. There has been a proliferation of reflective writing pedagogy within medical education to foster development of reflective capacity, extend empathy with deepened understanding of patients’ experience of illness, and promote practitioner well-being. At Alpert Med, “interactive” reflective writing with guided individualized feedback from interdisciplinary faculty to students’ reflective writing has been implemented in a Doctoring course and Family Medicine clerkship as an educational method to achieve these aims. Such initiatives, however, raise fundamental questions of reflection definition, program design, efficacy of methods, and outcomes assessment. Within this article, we consider opportunities and challenges associated with implementation of reflective writing curricula for promotion of reflective capacity within medical education. We reflect upon reflection. PMID:20407840

Sleep Duration and School Readiness of Chinese Preschool Children.

Science.gov (United States)

Tso, Winnie; Rao, Nirmala; Jiang, Fan; Li, Albert Martin; Lee, So-Lun; Ho, Frederick Ka-Wing; Li, Sophia Ling; Ip, Patrick

2016-02-01

To examine the average sleep duration in Chinese preschoolers and to investigate the association between sleep duration and school readiness. This is a cross-sectional study that included 553 Chinese children (mean age = 5.46 years) from 20 preschools in 2 districts of Hong Kong. Average daily sleep duration in the last week was reported by parents and school readiness as measured by the teacher-rated Chinese Early Development Instrument (CEDI). Most Chinese preschoolers had 9-10 hours of sleep per day. Only 11% of preschoolers had the recommended 11-12 hours of sleep per day. This group was associated with more "very ready" CEDI domains. Sleep deprivation (≤7 hours per day) was associated with a lower CEDI total score, lower scores in the emotional maturity and language/cognitive domain, and prosocial behaviors subdomain but a greater score in the hyperactivity/inattention subdomain. Children with a lower family socioeconomic index, lower maternal education level, infrequent parent-child interactions, and who used electronic devices for more than 3 hours per day had shortened sleep durations. Optimal sleep duration was associated with better school readiness in preschool children, whereas sleep deprivation was associated with lower school readiness, more hyperactivity and inattention, and less prosocial behavior. Copyright © 2016 Elsevier Inc. All rights reserved.

P-wave duration and the risk of atrial fibrillation

DEFF Research Database (Denmark)

Nielsen, Jonas B; Kühl, Jørgen T; Pietersen, Adrian

2015-01-01

BACKGROUND: Results on the association between P-wave duration and the risk of atrial fibrillation (AF) are conflicting. OBJECTIVE: The purpose of this study was to obtain a detailed description of the relationship between P-wave duration and the risk of AF. METHODS: Using computerized analysis o...

Frequency, duration and predictors of bronchiolitis episodes of care among infants ≥32 weeks gestation in a large integrated healthcare system: a retrospective cohort study

Directory of Open Access Journals (Sweden)

Flaherman Valerie J

2012-06-01

Full Text Available Abstract Background Bronchiolitis is common in the first two years of life and is the most frequent cause of hospitalization in this age group. No previous studies have used an episode-of-care analysis to describe the frequency, duration, and predictors of bronchiolitis episodes of care during the first two years. Methods We conducted a retrospective cohort study of 123,264 infants ≥32 weeks gestation born at 6 Northern California Kaiser Permanente hospitals between 1996 and 2002. We used electronic medical records to concatenate hospital, emergency department and outpatient health care encounters for bronchiolitis into discrete episodes of care. We used descriptive statistics to report frequency and duration of bronchiolitis episodes and used logistic regression to assess the effect of gestational age and other clinical and demographic predictors on the outcome of bronchiolitis episodes. Results Among all infants, the rate of bronchiolitis episodes was 162 per 1000 children during the first 2 years of life; approximately 40% required >1 day of medical attention with a mean duration of 7.0 ± 5.9 days. Prematurity was associated with increased risk of bronchiolitis episodes and longer duration. Bronchiolitis episodes rates per 1000 infants were 246 for 32–33 weeks gestational age, 204 for 34–36 weeks, and 148–178 for >36 weeks. Male gender, African-American and Hispanic race/ethnicity, and parental history of asthma were associated with an increased risk of having a bronchiolitis episode and/or longer duration. Conclusions Bronchiolitis episodes of care are frequent during the first two years of life and the duration ranges from 1 to 27 days. Prematurity was associated with more frequent and longer duration of bronchiolitis episodes of care, which may reflect illness severity and/or perceived vulnerability.

Supervision for superheroes: the case for reflective professional supervision for senior doctors.

Science.gov (United States)

Austin, Helen

2016-05-06

The practice of medicine is inherently stressful with regular exposure to trauma and the distress of others. There is a culture in medicine that doctors should not be affected by such things, although it is well recognised that doctors have higher rates of depression, anxiety, suicide, and substance abuse than the general public. Reflective professional supervision is a forum where the complexities of the interpersonal interactions that underpin the provision of healthcare can be explored in a supportive and confidential setting. It is argued that this is a process that should continue for the duration of a doctor's career, with potential benefits including enhanced job satisfaction and resilience, better workplace communication and improved interpersonal skills.

Striatal activation reflects urgency in perceptual decision making.

Science.gov (United States)

van Maanen, Leendert; Fontanesi, Laura; Hawkins, Guy E; Forstmann, Birte U

2016-10-01

Deciding between multiple courses of action often entails an increasing need to do something as time passes - a sense of urgency. This notion of urgency is not incorporated in standard theories of speeded decision making that assume information is accumulated until a critical fixed threshold is reached. Yet, it is hypothesized in novel theoretical models of decision making. In two experiments, we investigated the behavioral and neural evidence for an "urgency signal" in human perceptual decision making. Experiment 1 found that as the duration of the decision making process increased, participants made a choice based on less evidence for the selected option. Experiment 2 replicated this finding, and additionally found that variability in this effect across participants covaried with activation in the striatum. We conclude that individual differences in susceptibility to urgency are reflected by striatal activation. By dynamically updating a response threshold, the striatum is involved in signaling urgency in humans. Copyright © 2016 Elsevier Inc. All rights reserved.

13 CFR 107.830 - Minimum duration/term of financing.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Minimum duration/term of financing... INVESTMENT COMPANIES Financing of Small Businesses by Licensees Structuring Licensee's Financing of An Eligible Small Business: Terms and Conditions of Financing § 107.830 Minimum duration/term of financing. (a...

Evolution of the Cerro Prieto geothermal system as interpreted from vitrinite reflectance under isothermal conditions

Energy Technology Data Exchange (ETDEWEB)

Barker, C.E. (US Geological Survey, Denver, CO); Pawlewicz, M.J.; Bostick, N.H.; Elders, W.A.

1981-01-01

Temperature estimates from reflectance data in the Cerro Prieto system correlate with modern temperature logs and temperature estimates from fluid inclusion and oxygen isotope geothermometry indicating that the temperature in the central portion of the Cerro Prieto System is now at its historical maximum. Isoreflectance lines formed by contouring vitrinite reflectance data for a given isothermal surface define an imaginary surface that indicates an apparent duration of heating in the system. The 250/sup 0/C isothermal surface has a complex dome-like form suggesting a localized heat source that has caused shallow heating in the central portion of this system. Isoreflectance lines relative to this 250/sup 0/C isothermal surface define a zone of low reflectance roughly corresponding to the crest of the isothermal surface. Comparison of these two surfaces suggest that the shallow heating in the central portion of Cerro Prieto is young relative to the heating (to 250/sup 0/C) on the system margins. Laboratory and theoretical models of hydrothermal convection cells suggest that the form of the observed 250/sup 0/C isothermal surface and the reflectance surface derived relative to it results from the convective rise of thermal fluids under the influence of a regional hydrodynamic gradient that induces a shift of the hydrothermal heating effects to the southwest.

Short-term memory for event duration: modality specificity and goal dependency.

Science.gov (United States)

Takahashi, Kohske; Watanabe, Katsumi

2012-11-01

Time perception is involved in various cognitive functions. This study investigated the characteristics of short-term memory for event duration by examining how the length of the retention period affects inter- and intramodal duration judgment. On each trial, a sample stimulus was followed by a comparison stimulus, after a variable delay period (0.5-5 s). The sample and comparison stimuli were presented in the visual or auditory modality. The participants determined whether the comparison stimulus was longer or shorter than the sample stimulus. The distortion pattern of subjective duration during the delay period depended on the sensory modality of the comparison stimulus but was not affected by that of the sample stimulus. When the comparison stimulus was visually presented, the retained duration of the sample stimulus was shortened as the delay period increased. Contrarily, when the comparison stimulus was presented in the auditory modality, the delay period had little to no effect on the retained duration. Furthermore, whenever the participants did not know the sensory modality of the comparison stimulus beforehand, the effect of the delay period disappeared. These results suggest that the memory process for event duration is specific to sensory modality and that its performance is determined depending on the sensory modality in which the retained duration will be used subsequently.

Insomnia with short sleep duration and mortality: the Penn State cohort.

Science.gov (United States)

Vgontzas, Alexandros N; Liao, Duanping; Pejovic, Slobodanka; Calhoun, Susan; Karataraki, Maria; Basta, Maria; Fernández-Mendoza, Julio; Bixler, Edward O

2010-09-01

Because insomnia with objective short sleep duration is associated with increased morbidity, we examined the effects of this insomnia subtype on all-cause mortality. Longitudinal. Sleep laboratory. 1,741 men and women randomly selected from Central Pennsylvania. Participants were studied in the sleep laboratory and were followed-up for 14 years (men) and 10 years (women). "Insomnia" was defined by a complaint of insomnia with duration > or = 1 year. "Normal sleeping" was defined as absence of insomnia. Polysomnographic sleep duration was classified into two categories: the "normal sleep duration group" subjects who slept > or = 6 h and the "short sleep duration group" subjects who slept insomnia" group, (OR = 4.00, CI 1.14-13.99) after adjusting for diabetes, hypertension, and other confounders. Furthermore, there was a marginally significant trend (P = 0.15) towards higher mortality risk from insomnia and short sleep in patients with diabetes or hypertension (OR = 7.17, 95% CI 1.41-36.62) than in those without these comorbid conditions (OR = 1.45, 95% CI 0.13-16.14). In women, mortality was not associated with insomnia and short sleep duration. Insomnia with objective short sleep duration in men is associated with increased mortality, a risk that has been underestimated.

Parareal in Time for Dynamic Simulations of Power Systems

Energy Technology Data Exchange (ETDEWEB)

Gurrala, Gurunath [ORNL; Dimitrovski, Aleksandar D [ORNL; Pannala, Sreekanth [ORNL; Simunovic, Srdjan [ORNL; Starke, Michael R [ORNL

2015-01-01

In recent years, there have been significant developments in parallel algorithms and high performance parallel computing platforms. Parareal in time algorithm has become popular for long transient simulations (e.g., molecular dynamics, fusion, reacting flows). Parareal is a parallel algorithm which divides the time interval into sub-intervals and solves them concurrently. This paper investigates the applicability of the parareal algorithm to power system dynamic simulations. Preliminary results on the application of parareal for multi-machine power systems are reported in this paper. Two widely used test systems, WECC 3-generator 9-bus system, New England 10-generator 39- bus system, is used to explore the effectiveness of the parareal. Severe 3 phase bus faults are simulated using both the classical and detailed models of multi-machine power systems. Actual Speedup of 5-7 times is observed assuming ideal parallelization. It has been observed that the speedup factors of the order of 20 can be achieved by using fast coarse approximations of power system models. Dependency of parareal convergence on fault duration and location has been observed.

Socioeconomic differentials in divorce risk by duration of marriage

Directory of Open Access Journals (Sweden)

2002-11-01

Full Text Available Using register-based data on Finnish first marriages that were intact at the end of 1990 (about 2.1 million marriage-years and followed up for divorce in 1991-1993 (n = 21,204, this research explored the possibility that the effect of spouses' socioeconomic position on divorce risk varies according to duration of marriage. The comparatively high divorce risks for spouses with little formal education and for spouses in manual worker occupations were found to be specific to marriages of relatively short duration. In contrast, such factors as unemployment, wife's high income, and living in a rented dwelling were found to increase divorce risk at all marital durations.

Reflection groups

International Nuclear Information System (INIS)

Eggermont, G.

2006-01-01

In 2005, PISA organised proactive meetings of reflection groups on involvement in decision making, expert culture and ethical aspects of radiation protection.All reflection group meetings address particular targeted audiences while the output publication in book form is put forward

Determinants of sick-leave duration : A tool for managers?

NARCIS (Netherlands)

Flach, P.A.; Krol, B.; Groothoff, J.W.

AIMS: To provide managers with tools to manage episodes of sick-leave of their employees, the influence of factors such as age, gender, duration of tenure, working full-time or part-time, cause and history of sick-leave, salary and education on sick-leave duration was studied. METHOD: In a

Terrestrial irradiation-sunshine duration clustering and prediction

International Nuclear Information System (INIS)

Sen, Zekai; Oeztopal, Ahmet

2003-01-01

The relationship between terrestrial irradiance and sunshine duration is not crisp and there are scatters around a general trend, which most often is expressed to occur in the form of a linear expression. This study presents a way of grouping the solar irradiation-sunshine duration data into convenient seasonal subgroups and then makes predictions within each of the groups quantitatively. In the classical Angstroem or other approaches, the seasonal variations are not considered, and therefore, rather global parameter estimations are obtained. However, the seasonal methodology of this paper provides more detailed interpretations in addition to seasonal effects and parameter estimations

Estimates of leaf area index from spectral reflectance of wheat under different cultural practices and solar angle

Science.gov (United States)

Asrar, G.; Kanemasu, E. T.; Yoshida, M.

1985-01-01

The influence of management practices and solar illumination angle on the leaf area index (LAI) was estimated from measurements of wheat canopy reflectance evaluated by two methods, a regression formula and an indirect technique. The date of planting and the time of irrigation in relation to the stage of plant growth were found to have significant effects on the development of leaves in spring wheat. A reduction in soil moisture adversely affected both the duration and magnitude of the maximum LAI for late planting dates. In general, water stress during vegetative stages resulted in a reduction in maximum LAI, while water stress during the reproductive period shortened the duration of green LAI in spring wheat. Canopy geometry and solar angle also affected the spectral properties of the canopies, and hence the estimated LAI. Increase in solar zenith angles resulted in a general increase in estimated LAI obtained from both methods.

Duration of unemployment and suicide in Australia over the period 1985-2006: an ecological investigation by sex and age during rising versus declining national unemployment rates.

Science.gov (United States)

Milner, Allison; Page, Andrew; LaMontagne, Anthony D

2013-03-01

The relationship between unemployment and suicide may be sensitive to demographic factors, national unemployment rates, and length of time without employment. This study investigated these factors in relation to suicide in Australia for the period 1985-2006, in an ecological study. The outcome variable was annual suicide rate by age group, sex and the eight states and territories over 22 years of observation (total observations=1760). The main predictor variable was the average duration of unemployment in the population, categorised into three time periods (4 weeks). Poisson regression models were used to investigate the relationship between duration of unemployment and suicide over the years 1985-2006 in a series of cross-sectional analyses. Interaction analyses indicated significant differences during periods of declining or increasing labour market opportunity and by age group. During periods of declining unemployment rates in the country, longer durations of unemployment were associated with higher male suicide rates. During periods of increasing unemployment in the country, longer unemployment duration was associated with lower male suicide rates. Effect modification was also apparent by age-group, with stronger associations between unemployment duration and male suicide evident in those aged 25-34 and 55-64, and weaker associations in those aged 15-24 and 44-54 years. Longer length of unemployment was not associated with an increase in female suicide rates. The labour market opportunities in Australia modified the effect of duration of unemployment on suicide, and the effect was more prominent in men and older age groups. This may reflect social norms and acceptability about unemployment, as well as life-stage influences associated with transitions into and out of the labour market.

Marked exacerbation of orthostatic intolerance after long- vs. short-duration spaceflight in veteran astronauts

Science.gov (United States)

Meck, J. V.; Reyes, C. J.; Perez, S. A.; Goldberger, A. L.; Ziegler, M. G.

2001-01-01

OBJECTIVE: The incidence of postflight orthostatic intolerance after short-duration spaceflight is about 20%. However, the incidence after long-duration spaceflight was unknown. The purpose of this study was to test the hypothesis that orthostatic intolerance is more severe after long-duration than after short-duration flight. METHODS: We performed tilt tests on six astronauts before and after long-duration (129-190 days) spaceflights and compared these data with data obtained during stand tests before and after previous short-duration missions. RESULTS: Five of the six astronauts studied became presyncopal during tilt testing after long-duration flights. Only one had become presyncopal during stand testing after short-duration flights. We also compared the long-duration flight tilt test data to tilt test data from 20 different astronauts who flew on the short-duration Shuttle missions that delivered and recovered the astronauts to and from the Mir Space Station. Five of these 20 astronauts became presyncopal on landing day. Heart rate responses to tilt were no different between astronauts on long-duration flights and astronauts on short-duration flights, but long-duration subjects had lower stroke volumes and cardiac outputs than short-duration presyncopal subjects, suggesting a possible decrease in cardiac contractile function. One subject had subnormal norepinephrine release with upright posture after the long flight but not after the short flight. Plasma volume losses were not greater after long flights. CONCLUSION: Long-duration spaceflight markedly increases orthostatic intolerance, probably with multiple contributing factors.

Liberating Moral Reflection

Science.gov (United States)

Horell, Harold D.

2013-01-01

The author argues that if we are to foster life-giving and liberating moral reflection, we must first liberate moral reflection from distortions; specifically, from the distorting effects of moral insensitivity, destructive moral relativism, and confusions resulting from a failure to understand the dynamics of moral reflection. The author proposes…

How Hearing Impairment Affects Sentence Comprehension: Using Eye Fixations to Investigate the Duration of Speech Processing

DEFF Research Database (Denmark)

Wendt, Dorothea; Kollmeier, Birger; Brand, Thomas

2015-01-01

; this measure uses eye fixations recorded while the participant listens to a sentence. Eye fixations toward a target picture (which matches the aurally presented sentence) were measured in the presence of a competitor picture. Based on the recorded eye fixations, the single target detection amplitude, which...... reflects the tendency of the participant to fixate the target picture, was used as a metric to estimate the duration of sentence processing. The single target detection amplitude was calculated for sentence structures with different levels of linguistic complexity and for different listening conditions......: in quiet and in two different noise conditions. Participants with hearing impairment spent more time processing sentences, even at high levels of speech intelligibility. In addition, the relationship between the proposed online measure and listener-specific factors, such as hearing aid use and cognitive...

Reflection ciphers

DEFF Research Database (Denmark)

Boura, Christina; Canteaut, Anne; Knudsen, Lars Ramkilde

2017-01-01

study the necessary properties for this coupling permutation. Special care has to be taken of some related-key distinguishers since, in the context of reflection ciphers, they may provide attacks in the single-key setting.We then derive some criteria for constructing secure reflection ciphers...

20 CFR 702.402 - Employer's duty to furnish; duration.

Science.gov (United States)

2010-04-01

... Care and Supervision § 702.402 Employer's duty to furnish; duration. It is the duty of the employer to furnish appropriate medical care (as defined in § 702.401(a)) for the employee's injury, and for such... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Employer's duty to furnish; duration. 702.402...

Duration of gestation in pregnant dogs carrying cloned fetuses.

Science.gov (United States)

Kim, Min Jung; Oh, Hyun Ju; Park, Jung Eun; Kim, Geon A; Park, Eun Jung; Jo, Young Kwang; Lee, Byeong Chun

2013-01-15

The aim of this study was to investigate gestation duration and the physiologic characteristics of pregnant dogs bearing cloned fetuses, especially in the prepartum period. A retrospective study was performed to compare gestation duration in females pregnant with cloned (somatic cell nuclear transfer) fetuses (cloned group) with those bearing noncloned fetuses (control group), and effects of litter size, birth weight, and breed of somatic cell donors on gestation duration in the cloned group were evaluated. Clinical delivery onset signs associated with serum progesterone concentration and rectal temperature were also compared in both groups. The gestation duration calculated from day of ovulation was significantly longer in the cloned (62.8 ± 0.3 days) versus the control group (60.9 ± 0.5 days; P dogs bearing cloned fetuses might be because of the smaller litter size in this group. Also, the weaker drop in serum progesterone levels in the prepartum period in cloned dog pregnancies indicates that the parturition signaling process might be altered resulting in longer gestation periods. Copyright © 2013 Elsevier Inc. All rights reserved.

Sleep Duration and Quality in Pregnant Women: A Cross-Sectional Survey in China

Directory of Open Access Journals (Sweden)

Xianglong Xu

2017-07-01

Full Text Available Objectives: Good maternal health and fetal development require sufficient and good quality of sleep during pregnancy. This study investigated sleep duration and quality in pregnant women, assessing factors with possibly influence on sleep. Method: A cross-sectional survey was conducted on pregnant women between June and August in 2015 in 16 hospitals in five provinces in China. A total of 2345 pregnant women aged 18 years and older were surveyed. Insufficient sleeping duration was defined as sleeping of less than 7 h per day. Excessive sleep duration was defined as sleeping of more than 9 h per day. Results: A total of 561 (23.9% participants reported insufficient sleeping duration, whereas 485 (20.9% claimed excessive sleep duration. A total of 358 (15.2% of pregnant women reported problems regarding sleep quality. Compared to pregnant women with sufficient sleeping duration, those with insufficient sleeping duration were prone to have poor sleep quality, whereas those with excessive sleeping duration featured low possibility of poor sleep quality. High-risk groups of insufficient sleep duration include women of Han nationality, with siblings, in their first trimester of pregnancy, receiving care in low-capacity/quality hospital settings, and with daily or 1–3 days of secondhand smoke exposure. High-risk groups of excessive sleep duration include women living in rural areas, unemployed, in their third trimester of pregnancy, and receiving care in medium-capacity/quality hospital settings. High-risk groups of poor sleep quality include women of non-Han nationality, low income level, in their third trimester of pregnancy, and with insufficient sleep duration. Conclusions: Insufficient/excessive sleep duration and poor sleep quality commonly occur during pregnancy in China. Findings provide a better understanding of the influencing factors of insufficient/excessive sleep duration and poor quality of sleep. These findings have some implications

Genetic Associations with Gestational Duration and Spontaneous Preterm Birth

DEFF Research Database (Denmark)

Zhang, G.; Feenstra, B.; Bacelis, J.

2017-01-01

. METHODS: We performed a genomewide association study in a discovery set of samples obtained from 43,568 women of European ancestry using gestational duration as a continuous trait and term or preterm (... of 8643 women) to test for replication of genomic loci that had significant genomewide association (Pdiscovery set. RESULTS: In the discovery and replication data sets, four loci (EBF1, EEFSEC, AGTR2, and WNT4) were...... significantly associated with gestational duration. Functional analysis showed that an implicated variant in WNT4 alters the binding of the estrogen receptor. The association between variants in ADCY5 and RAP2C and gestational duration had suggestive significance in the discovery set and significant evidence...

Can we predict the duration of an interglacial?

Directory of Open Access Journals (Sweden)

P. C. Tzedakis

2012-09-01

Full Text Available Differences in the duration of interglacials have long been apparent in palaeoclimate records of the Late and Middle Pleistocene. However, a systematic evaluation of such differences has been hampered by the lack of a metric that can be applied consistently through time and by difficulties in separating the local from the global component in various proxies. This, in turn, means that a theoretical framework with predictive power for interglacial duration has remained elusive. Here we propose that the interval between the terminal oscillation of the bipolar seesaw and three thousand years (kyr before its first major reactivation provides an estimate that approximates the length of the sea-level highstand, a measure of interglacial duration. We apply this concept to interglacials of the last 800 kyr by using a recently-constructed record of interhemispheric variability. The onset of interglacials occurs within 2 kyr of the boreal summer insolation maximum/precession minimum and is consistent with the canonical view of Milankovitch forcing pacing the broad timing of interglacials. Glacial inception always takes place when obliquity is decreasing and never after the obliquity minimum. The phasing of precession and obliquity appears to influence the persistence of interglacial conditions over one or two insolation peaks, leading to shorter (~ 13 kyr and longer (~ 28 kyr interglacials. Glacial inception occurs approximately 10 kyr after peak interglacial conditions in temperature and CO₂, representing a characteristic timescale of interglacial decline. Second-order differences in duration may be a function of stochasticity in the climate system, or small variations in background climate state and the magnitude of feedbacks and mechanisms contributing to glacial inception, and as such, difficult to predict. On the other hand, the broad duration of an interglacial may be determined by the phasing of astronomical parameters and the history of

Evaluation of retro-reflective coating performance by reflectance and perceived relative brightness measurements

International Nuclear Information System (INIS)

Luse, Kaiva; Pausus, Anete; Karitans, Varis; Ozolins, Maris; Tukisa, Madara

2011-01-01

Retro-reflective properties of six types and five different colors or retro-reflective materials were discussed in this paper. Reflectance optical indicatrix of samples was determined and compared to obtained psychophyisical data of perceived brightness of human observer. Microscopic structure of the retro-reflective active regions of RR's was studied. Statistically significant differences in reflectivity and brightness of various types and colors of RR's were found.

Secondhand Smoke Exposure, Restless Sleep, and Sleep Duration in Adolescents

Directory of Open Access Journals (Sweden)

Jennifer Schwartz

2014-01-01

Full Text Available Purpose. To examine whether secondhand smoke (SHS exposure is associated with restless sleep and/or nighttime sleep duration among adolescents. Methods. Data were analyzed from 1,592 adolescents who completed an internet-delivered survey as part of the British Columbia Adolescent Substance Use Survey cohort study. Ordinal logistic and linear regression models were used to examine associations between frequency of SHS exposure in the past month and frequency of restless sleep and nighttime sleep duration, respectively. Results. SHS exposure was significantly positively associated with restless sleep and significantly negatively associated with sleep duration. In fully adjusted models, compared with students who reported never being exposed to SHS in the past month, students who reported a low, medium, or high frequency of SHS exposure were 1.53, 1.76, and 2.51 times as likely, respectively, to report more frequent restless sleep (OR=1.53, 95% CI 1.08–2.16; OR=1.76, 95% CI 1.22–2.53; OR=2.51, 95% CI 1.59–3.98. With regard to sleep duration, as frequency of SHS exposure increased by one category, nighttime sleep duration during the week and weekend decreased by 4 minutes (B=-0.06, 95% CI=-0.01–-0.11 and 6 minutes (B=-0.09, 95% CI=-0.03–-0.14, respectively. Conclusions. This study suggests that frequency of SHS exposure has a significant dose-response relationship with restless sleep and sleep duration in adolescents.

Changing word usage predicts changing word durations in New Zealand English.

Science.gov (United States)

Sóskuthy, Márton; Hay, Jennifer

2017-09-01

This paper investigates the emergence of lexicalized effects of word usage on word duration by looking at parallel changes in usage and duration over 130years in New Zealand English. Previous research has found that frequent words are shorter, informative words are longer, and words in utterance-final position are also longer. It has also been argued that some of these patterns are not simply online adjustments, but are incorporated into lexical representations. While these studies tend to focus on the synchronic aspects of such patterns, our corpus shows that word-usage patterns and word durations are not static over time. Many words change in duration and also change with respect to frequency, informativity and likelihood of occurring utterance-finally. Analysis of changing word durations over this time period shows substantial patterns of co-adaptation between word usage and word durations. Words that are increasing in frequency are becoming shorter. Words that are increasing/decreasing in informativity show a change in the same direction in duration (e.g. increasing informativity is associated with increasing duration). And words that are increasingly appearing utterance-finally are lengthening. These effects exist independently of the local effects of the predictors. For example, words that are increasing utterance-finally lengthen in all positions, including utterance-medially. We show that these results are compatible with a number of different views about lexical representations, but they cannot be explained without reference to a production-perception loop that allows speakers to update their representations dynamically on the basis of their experience. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

The Effect of Task Duration on Event-Based Prospective Memory: A Multinomial Modeling Approach

Directory of Open Access Journals (Sweden)

Hongxia Zhang

2017-11-01

Full Text Available Remembering to perform an action when a specific event occurs is referred to as Event-Based Prospective Memory (EBPM. This study investigated how EBPM performance is affected by task duration by having university students (n = 223 perform an EBPM task that was embedded within an ongoing computer-based color-matching task. For this experiment, we separated the overall task’s duration into the filler task duration and the ongoing task duration. The filler task duration is the length of time between the intention and the beginning of the ongoing task, and the ongoing task duration is the length of time between the beginning of the ongoing task and the appearance of the first Prospective Memory (PM cue. The filler task duration and ongoing task duration were further divided into three levels: 3, 6, and 9 min. Two factors were then orthogonally manipulated between-subjects using a multinomial processing tree model to separate the effects of different task durations on the two EBPM components. A mediation model was then created to verify whether task duration influences EBPM via self-reminding or discrimination. The results reveal three points. (1 Lengthening the duration of ongoing tasks had a negative effect on EBPM performance while lengthening the duration of the filler task had no significant effect on it. (2 As the filler task was lengthened, both the prospective and retrospective components show a decreasing and then increasing trend. Also, when the ongoing task duration was lengthened, the prospective component decreased while the retrospective component significantly increased. (3 The mediating effect of discrimination between the task duration and EBPM performance was significant. We concluded that different task durations influence EBPM performance through different components with discrimination being the mediator between task duration and EBPM performance.

Sperm Competition Risk and Sexual Coercion Predict Copulatory Duration in Humans

Directory of Open Access Journals (Sweden)

Nicole Barbaro

2015-12-01

Full Text Available A man whose romantic partner is sexually unfaithful is at risk of sperm competition and cuckoldry—unwitting investment in offspring to whom he is genetically unrelated. Men, therefore, may have evolved mechanisms to solve the adaptive problems of sperm competition and cuckoldry. The current research investigates another potential anti-cuckoldry tactic: reducing in-pair copulation (IPC duration, thereby more quickly placing his sperm into competition. We hypothesize that IPC duration will be negatively correlated with female infidelity (Hypothesis 1. We further hypothesize that IPC duration will be negatively correlated with sexual coercion (Hypothesis 2. Results of Study 1 (men’s reports, n = 410 indicate that both men’s perceptions of female infidelity and men’s sexual coercion predict shorter IPC duration. Results of Study 2 (women’s reports, n = 455 did not provide statistical support for the study hypotheses. The current research provides an initial investigation of men’s adjustment of copulatory duration and suggests that men reduce IPC duration and ejaculate more quickly at the couple’s most recent copulation, in response to greater risk of sperm competition and in the context of sexual coercion.

The Effect of Different Recovery Duration on Repeated Anaerobic Performance in Elite Cyclists

Directory of Open Access Journals (Sweden)

Harbili Sultan

2015-12-01

Full Text Available This study investigated the effect of recovery duration on repeated anaerobic performance in elite cyclists. The study followed a cross-over design protocol. Twelve elite male cyclists were randomly assigned to three groups (with recovery duration of 1, 2 and 3 min, respectively. All the subjects performed 4 repeated Wingate tests (4 × 30 s WT at 48 h intervals for three different recovery periods. No significant interaction was observed between the effects of recovery duration and repetition (p>0.05, whereas there was a significant main effect of repetition on peak power, mean power, and a fatigue index (p0.05. In contrast, mean power decreased significantly in repeated WTs with 1, 2 and 3 min recovery duration (p0.05. In a 4 × 30 s WT, peak power decreased in cycles with 1 and 2 min recovery duration, but remained unchanged with 3 min recovery duration, whereas mean power decreased in all recovery duration procedures. The WT with 1 min recovery duration caused greater fatigue. Although recovery duration affected both peak power and mean power, the effect on peak power was greater.

Reflective writing: the student nurse's perspective on reflective writing and poetry writing.

Science.gov (United States)

Coleman, Dawn; Willis, Diane S

2015-07-01

Reflective writing is a mandatory part of nurse education but how students develop their skills and use reflection as part of their experiential learning remains relatively unknown. Understanding reflective writing in all forms from the perspective of a student nurse is therefore important. To explore the use of reflective writing and the use of poetry in pre-registered nursing students. A qualitative design was employed to explore reflective writing in pre-registered nursing students. A small university in Scotland. BSc (Hons) Adult and Mental Health Pre-registration Student Nurses. Two focus groups were conducted with 10 student nurses during March 2012. Data was analysed thematically using the framework of McCarthy (1999). Students found the process of reflective writing daunting but valued it over time. Current educational methods, such as assessing reflective accounts, often lead to the 'narrative' being watered down and the student feeling judged. Despite this, reflection made students feel responsible for their own learning and research on the topic. Some students felt the use of models of reflection constricting, whilst poetry freed up their expression allowing them to demonstrate the compassion for their patient under their care. Poetry writing gives students the opportunity for freedom of expression, personal satisfaction and a closer connection with their patients, which the more formal approach to reflective writing did not offer. There is a need for students to have a safe and supportive forum in which to express and have their experiences acknowledged without the fear of being judged. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Feasibility of the current-duration approach to studying human fecundity

DEFF Research Database (Denmark)

Slama, Rémy; Ducot, Béatrice; Carstensen, Lisbeth

2006-01-01

of unprotected intercourse was defined for 69 women (5.7%). An additional 15 women (1.2%) were planning to start trying to become pregnant within the next 6 months. Parametric methods allowed, based on current duration of unprotected intercourse, estimation of fecundity as if the couples had been followed...... up (current-duration design). To illustrate the feasibility of the current-duration design, we contacted a random sample of 1204 French women age 18 to 44 years in 2004 and recruited those who were currently having unprotected sexual intercourse. The current duration since the beginning...... prospectively. The estimated proportion of couples not pregnant after 12 months of unprotected intercourse was 34% (95% confidence interval [CI] = 15-54%). The accelerated-failure time model allows study of the influence of environmental factors on fecundity. As an illustration, tobacco smoking by the woman...

The Impact of Mission Duration on a Mars Orbital Mission

Science.gov (United States)

Arney, Dale; Earle, Kevin; Cirillo, Bill; Jones, Christopher; Klovstad, Jordan; Grande, Melanie; Stromgren, Chel

2017-01-01

Performance alone is insufficient to assess the total impact of changing mission parameters on a space mission concept, architecture, or campaign; the benefit, cost, and risk must also be understood. This paper examines the impact to benefit, cost, and risk of changing the total mission duration of a human Mars orbital mission. The changes in the sizing of the crew habitat, including consumables and spares, was assessed as a function of duration, including trades of different life support strategies; this was used to assess the impact on transportation system requirements. The impact to benefit is minimal, while the impact on cost is dominated by the increases in transportation costs to achieve shorter total durations. The risk is expected to be reduced by decreasing total mission duration; however, large uncertainty exists around the magnitude of that reduction.

JACEE long duration balloon flights

International Nuclear Information System (INIS)

Burnett, T.; Iwai, J.; Lord, J.J.; Strausz, S.; Wilkes, R.J.; Dake, S.; Oda, H.; Miyamura, O.; Fuki, M.; Jones, W.V.; Gregory, J.; Hayashi, T.; Takahashi, U.; Tominaga, Y.; Wefel, J.P.; Fountain, W.; Derrickson, J.; Parnell, T.A.; Roberts, E.; Tabuki, T.; Watts, J.W.

1989-01-01

JACEE balloon-borne emulsion chamber detectors are used to observe the spectra and interactions of cosmic ray protons and nuclei in the energy range 1-100A TeV. Experience with long duration mid-latitude balloon flights and characteristics of the detector system that make it ideal for planned Antarctic balloon flights are discussed. 5 refs., 2 figs

Evaluation of retro-reflective coating performance by reflectance and perceived relative brightness measurements

Energy Technology Data Exchange (ETDEWEB)

Luse, Kaiva; Pausus, Anete; Karitans, Varis; Ozolins, Maris; Tukisa, Madara, E-mail: kaiva.luse@gmail.com [University of Latvia, Optometry and Vision Science Department, Kengaraga street 8, Riga LV-1063 (Latvia)

2011-06-23

Retro-reflective properties of six types and five different colors or retro-reflective materials were discussed in this paper. Reflectance optical indicatrix of samples was determined and compared to obtained psychophyisical data of perceived brightness of human observer. Microscopic structure of the retro-reflective active regions of RR's was studied. Statistically significant differences in reflectivity and brightness of various types and colors of RR's were found.

Sleep Duration and Academic Performance Among Student Pharmacists.

Science.gov (United States)

Zeek, Megan L; Savoie, Matthew J; Song, Matthew; Kennemur, Leanna M; Qian, Jingjing; Jungnickel, Paul W; Westrick, Salisa C

2015-06-25

To identify sleep patterns and frequency of daytime sleepiness and to assess the association between sleep duration and academic performance among student pharmacists. A cross-sectional design was used. An anonymous self-administered paper questionnaire was administered to first-year through third-year students at a pharmacy school. Questionnaires were completed by 364 student pharmacists (79.4% response rate and 93.8% cooperation rate). More than half of student pharmacists obtained less than 7 hours of sleep at night during a typical school week (54.7%) and a large majority on the night prior to an examination (81.7%). Almost half (47.8%) felt daytime sleepiness almost every day. Longer sleep duration the night prior to an examination was associated with higher course grades and semester grade point averages (GPAs). A majority of student pharmacists had suboptimal durations of sleep, defined as fewer than 7 hours. Adequate sleep the night prior to an examination was positively associated with student course grades and semester GPAs.

Thermotolerance and responses to short duration heat stress in tropical and temperate species

Science.gov (United States)

Marias, D.; Meinzer, F. C.; Still, C. J.

2017-12-01

phenotypically plastic and representative of the environment in which plants were grown, whereas iWUE appeared to reflect ecotypic differentiation and the climate of origin. Considering leaf age, heat stress duration, methodology, functional type, and climate of origin improves our understanding of physiological responses to short term heat stress.

Reflection as Self-Assessment

Science.gov (United States)

Pappas, Marjorie L.

2010-01-01

In this article, the author discusses how reflection can be used as self-assessment. Reflection involves not only thinking about a learning experience, but also questioning parts of the experience. Reflection is thinking about what one knows from the learning experience, what one might do differently the next time. Reflection is wondering about…

Common metabolic constraints on dive duration in endothermic and ectothermic vertebrates

Directory of Open Access Journals (Sweden)

April Hayward

2016-10-01

Full Text Available Dive duration in air-breathing vertebrates is thought to be constrained by the volume of oxygen stored in the body and the rate at which it is consumed (i.e., “oxygen store/usage hypothesis”. The body mass-dependence of dive duration among endothermic vertebrates is largely supportive of this model, but previous analyses of ectothermic vertebrates show no such body mass-dependence. Here we show that dive duration in both endotherms and ectotherms largely support the oxygen store/usage hypothesis after accounting for the well-established effects of temperature on oxygen consumption rates. Analyses of the body mass and temperature dependence of dive duration in 181 species of endothermic vertebrates and 29 species of ectothermic vertebrates show that dive duration increases as a power law with body mass, and decreases exponentially with increasing temperature. Thus, in the case of ectothermic vertebrates, changes in environmental temperature will likely impact the foraging ecology of divers.

Influence of the laser pulse duration on laser-produced plasma properties

International Nuclear Information System (INIS)

Drogoff, B Le; Margot, J; Vidal, F; Laville, S; Chaker, M; Sabsabi, M; Johnston, T W; Barthelemy, O

2004-01-01

In the framework of laser-induced plasma spectroscopy (LIPS) applications, time-resolved characteristics of laser-produced aluminium plasmas in air at atmospheric pressure are investigated for laser pulse durations ranging from 100 fs to 270 ps. Measurements show that for delays after the laser pulse longer than ∼100 ns, the plasma temperature increases slightly with the laser pulse duration, while the electron density is independent of it. In addition, as the pulse duration increases, the plasma radiation emission lasts longer and the spectral lines arise later from the continuum emission. The time dependence of the continuum emission appears to be similar whatever the duration of the laser pulse is, while the temporal evolution of the line emission seems to be affected mainly by the plasma temperature. Finally, as far as spectrochemical applications (such as LIPS) of laser-produced plasmas are concerned, this study highlights the importance of the choice of appropriate temporal gating parameters for each laser pulse duration

In-Hospital Haloperidol Use and Perioperative Changes in QTc-Duration

NARCIS (Netherlands)

Blom, M T; de Jonghe, A; van Munster, B C; de Rooij, S E; Tan, H L; van der Velde, Nathalie; Jansen, S.

2015-01-01

OBJECTIVES: Haloperidol may prolong ECG QTc-duration but is often prescribed perioperatively to hip-fracture patients. We aimed to determine (1) how QTc-duration changes perioperatively, (2) whether low-dose haloperidol-use influences these changes, and (3) which clinical variables are associated

How Changes in Financial Incentives Affect the Duration of Unemployment

NARCIS (Netherlands)

Lalive, R.; van Ours, J.C.; Zweimüller, J.

2004-01-01

This paper studies how changes in the two key parameters of unemployment insurance - the benefit replacement rate (RR) and the potential duration of benefits (PBD) - affect the duration of unemployment.In 1989, the Austrian government made unemployment insurance more generous by changing,

Designing a Reflective Teacher Education Course and Its Contribution to ELT Teachers' Reflectivity

Science.gov (United States)

Tajik, Leila; Pakzad, Kazem

2016-01-01

Researchers in the present study planned a reflective teacher education course and documented the contribution of such a course to improving teachers' reflectivity. Five English teachers took part in the reflective teacher education course designed by the researchers. To record how the course could help improve reflective teaching, researchers…

Sleep duration and RSA suppression as predictors of internalizing and externalizing behaviors.

Science.gov (United States)

Cho, Sunghye; Philbrook, Lauren E; Davis, Elizabeth L; Buss, Kristin A

2017-01-01

Although the conceptual interplay among the biological and clinical features of sleep, arousal, and emotion regulation has been noted, little is understood about how indices of sleep duration and parasympathetic reactivity operate jointly to predict adjustment in early childhood. Using a sample of 123 toddlers, the present study examined sleep duration and RSA reactivity as predictors of internalizing and externalizing behaviors. Parents reported on children's sleep duration and adjustment. RSA reactivity was assessed via children's responses to fear-eliciting stimuli and an inhibitory control challenge. Findings demonstrated that greater RSA suppression to both types of tasks in combination with longer sleep duration was concurrently associated with less internalizing. In contrast, greater RSA augmentation to an inhibitory control task in the context of shorter sleep duration predicted more externalizing 1 year later. The significance of duration of toddlers' sleep as well as the context in which physiological regulatory difficulties occurs is discussed. © 2016 Wiley Periodicals, Inc.

Prevalence of Healthy Sleep Duration among Adults--United States, 2014.

Science.gov (United States)

Liu, Yong; Wheaton, Anne G; Chapman, Daniel P; Cunningham, Timothy J; Lu, Hua; Croft, Janet B

2016-02-19

To promote optimal health and well-being, adults aged 18-60 years are recommended to sleep at least 7 hours each night (1). Sleeping disease, stroke, frequent mental distress, and all-cause mortality (2-4). Insufficient sleep impairs cognitive performance, which can increase the likelihood of motor vehicle and other transportation accidents, industrial accidents, medical errors, and loss of work productivity that could affect the wider community (5). CDC analyzed data from the 2014 Behavioral Risk Factor Surveillance System (BRFSS) to determine the prevalence of a healthy sleep duration (≥ 7 hours) among 444,306 adult respondents in all 50 states and the District of Columbia. A total of 65.2% of respondents reported a healthy sleep duration; the age-adjusted prevalence of healthy sleep was lower among non-Hispanic blacks, American Indians/Alaska Natives, Native Hawaiians/Pacific Islanders, and multiracial respondents, compared with non-Hispanic whites, Hispanics, and Asians. State-based estimates of healthy sleep duration prevalence ranged from 56.1% in Hawaii to 71.6% in South Dakota. Geographic clustering of the lowest prevalence of healthy sleep duration was observed in the southeastern United States and in states along the Appalachian Mountains, and the highest prevalence was observed in the Great Plains states. More than one third of U.S. respondents reported typically sleeping sleep health; worksite shift policies that ensure healthy sleep duration for shift workers, particularly medical professionals, emergency response personnel, and transportation industry personnel; and opportunities for health care providers to discuss the importance of healthy sleep duration with patients and address reasons for poor sleep health.

Breastfeeding Duration and Authoritative Feeding Practices in First-Time Mothers.

Science.gov (United States)

Jansen, Elena; Mallan, Kimberley M; Byrne, Rebecca; Daniels, Lynne A; Nicholson, Jan M

2016-08-01

Longer breastfeeding duration appears to have a protective effect against childhood obesity. This effect may be partially mediated by maternal feeding practices during the first years of life. However, the few studies that have examined links between breastfeeding duration and subsequent feeding practices have yielded conflicting results. Using a large sample of first-time mothers and a newly validated, comprehensive measure of maternal feeding (the Feeding Practices and Structure Questionnaire), this study examined associations between breastfeeding duration and maternal feeding practices at child age 24 months. Mothers (n = 458) enrolled in the NOURISH trial provided data on breastfeeding at child age 4, 14, and 24 months, and on feeding practices at 24 months. Structural equation modeling was used to examine associations between breastfeeding duration and 5 nonresponsive and 4 structure-related "authoritative" feeding practices, adjusting for a range of maternal and child characteristics. The model showed acceptable fit (χ(2)/df = 1.68; root mean square error of approximation = .04, comparative fit index = .91, and Tucker-Lewis index = .89) and longer breastfeeding duration was negatively associated with 4 out of 5 nonresponsive feeding practices and positively associated with 3 out of 4 structure-related feeding practices. Overall, these results suggest that mothers who breastfeed longer reported using more appropriate feeding practices. These data demonstrate an association between longer breastfeeding duration and authoritative feeding practices characterized by responsiveness and structure, which may partly account for the apparent protective effect of breastfeeding on childhood obesity. © The Author(s) 2015.

Self-Reflection

DEFF Research Database (Denmark)

Fausing, Bent

2016-01-01

will take a look at the establishing of the modern self and possibilities of self-reflection, too. My examples will be from the so-called dark-selfies and from a new selfie form, which merge the present with the previous progressing into the future. I will discuss the media reflections as loos and/or gain...

Personal Reflections

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education. Personal Reflections. Articles in Resonance – Journal of Science Education. Volume 6 Issue 3 March 2001 pp 90-93 Personal Reflections. Why did I opt for Career in Science? Jayant V Narlikar · More Details Fulltext PDF. Volume 9 Issue 8 August 2004 pp 89-89 ...

Context-Dependent Neural Modulations in the Perception of Duration.

Science.gov (United States)

Murai, Yuki; Yotsumoto, Yuko

2016-01-01

Recent neuroimaging studies have revealed that distinct brain networks are recruited in the perception of sub- and supra-second timescales, whereas psychophysical studies have suggested that there are common or continuous mechanisms for perceiving these two durations. The present study aimed to elucidate the neural implementation of such continuity by examining the neural correlates of peri-second timing. We measured neural activity during a duration reproduction task using functional magnetic resonance imaging. Our results replicate the findings of previous studies in showing that separate neural networks are recruited for sub-versus supra-second time perception: motor systems including the motor cortex and the supplementary motor area for sub-second perception, and the frontal, parietal, and auditory cortical areas for supra-second perception. We further found that the peri-second perception activated both the sub- and supra-second networks, and that the timing system that processed duration perception in previous trials was more involved in subsequent peri-second processing. These results indicate that the sub- and supra-second timing systems overlap at around 1 s, and cooperate to optimally encode duration based on the hysteresis of previous trials.

An hp symplectic pseudospectral method for nonlinear optimal control

Science.gov (United States)

Peng, Haijun; Wang, Xinwei; Li, Mingwu; Chen, Biaosong

2017-01-01

An adaptive symplectic pseudospectral method based on the dual variational principle is proposed and is successfully applied to solving nonlinear optimal control problems in this paper. The proposed method satisfies the first order necessary conditions of continuous optimal control problems, also the symplectic property of the original continuous Hamiltonian system is preserved. The original optimal control problem is transferred into a set of nonlinear equations which can be solved easily by Newton-Raphson iterations, and the Jacobian matrix is found to be sparse and symmetric. The proposed method, on one hand, exhibits exponent convergence rates when the number of collocation points are increasing with the fixed number of sub-intervals; on the other hand, exhibits linear convergence rates when the number of sub-intervals is increasing with the fixed number of collocation points. Furthermore, combining with the hp method based on the residual error of dynamic constraints, the proposed method can achieve given precisions in a few iterations. Five examples highlight the high precision and high computational efficiency of the proposed method.

Detecting long-duration cloud contamination in hyper-temporal NDVI imagery

NARCIS (Netherlands)

Ali, A.; de Bie, C.A.J.M.; Skidmore, A.K.

2013-01-01

Cloud contamination impacts on the quality of hyper-temporal NDVI imagery and its subsequent interpretation. Short-duration cloud impacts are easily removed by using quality flags and an upper envelope filter, but long-duration cloud contamination of NDVI imagery remains. In this paper, an approach

Measurements of plasma mirror reflectivity and focal spot quality for tens of picosecond laser pulses

Science.gov (United States)

Forestier-Colleoni, Pierre; Williams, Jackson; Scott, Graeme; Mariscal, Dereck. A.; McGuffey, Christopher; Beg, Farhat N.; Chen, Hui; Neely, David; Ma, Tammy

2017-10-01

The Advanced Radiographic Capability (ARC) laser at the NIF (LLNL) is high-energy ( 4 kJ) with a pulse length of 30ps, and is capable of focusing to an intensity of 1018W/cm2 with a 100 μm focal spot. The ARC laser is at an intensity which can be used to produce proton beams. However, for applications such as radiography and warm dense matter creation, a higher laser intensity may be desired to generate more energetic proton beams. One possibility to increase the intensity is to decrease the focused spot size by employing a smaller f-number optic. But it is difficult to implement such an optic or to bring the final focusing parabola closer to the target within the complicated NIF chamber geometry. A proposal is to use ellipsoidal plasma mirrors (PM) for fast focusing of the ARC laser light, thereby increasing the peak intensity. There is uncertainty, however, in the survivability and reflectivity of PM at such long pulse durations. Here, we show experimental results from the Titan laser to study the reflectivity of flat PM as a function of laser pulse length. A calorimeter was used to measure the PM reflectivity. We also observed degradation of the far and near field energy distribution of the laser after the reflection by the PM for pulse-lengths beyond 10ps. Contract DE-AC52-07NA27344. Funded by the LLNL LDRD program: tracking code 17-ERD-039.

Interest Rate Risk Management using Duration Gap Methodology

Directory of Open Access Journals (Sweden)

Dan Armeanu

2008-01-01

Full Text Available The world for financial institutions has changed during the last 20 years, and become riskier and more competitive-driven. After the deregulation of the financial market, banks had to take on extensive risk in order to earn sufficient returns. Interest rate volatility has increased dramatically over the past twenty-five years and for that an efficient management of this interest rate risk is strong required. In the last years banks developed a variety of methods for measuring and managing interest rate risk. From these the most frequently used in real banking life and recommended by Basel Committee are based on: Reprising Model or Funding Gap Model, Maturity Gap Model, Duration Gap Model, Static and Dynamic Simulation. The purpose of this article is to give a good understanding of duration gap model used for managing interest rate risk. The article starts with a overview of interest rate risk and explain how this type of risk should be measured and managed within an asset-liability management. Then the articles takes a short look at methods for measuring interest rate risk and after that explains and demonstrates how can be used Duration Gap Model for managing interest rate risk in banks.The world for financial institutions has changed during the last 20 years, and become riskier and more competitive-driven. After the deregulation of the financial market, banks had to take on extensive risk in order to earn sufficient returns. Interest rate volatility has increased dramatically over the past twenty-five years and for that an efficient management of this interest rate risk is strong required. In the last years banks developed a variety of methods for measuring and managing interest rate risk. From these the most frequently used in real banking life and recommended by Basel Committee are based on: Reprising Model or Funding Gap Model, Maturity Gap Model, Duration Gap Model, Static and Dynamic Simulation. The purpose of this article is to give a

Urbanization effect on trends in sunshine duration in China

Directory of Open Access Journals (Sweden)

Y. Wang

2017-07-01

Full Text Available There is an ongoing debate on whether the observed decadal variations in surface solar radiation, known as dimming and brightening periods, are a large-scale or solely local phenomenon. We investigated this issue using long-term sunshine duration records from China, which experienced a rapid increase in urbanization during the past decades. Over the period 1960–2013, 172 pairs of urban and nearby rural stations were analyzed. Urban and rural sunshine duration trends show similar spatial patterns during a dimming phase (1960–1989 and a subsequent period during which trends were leveling off (1990–2013. This indicates that rather than local effects, the trends in sunshine duration are on more of a national or regional scale in China. Nevertheless, in the dimming phase, the declining rate of sunshine duration in rural areas is around two-thirds of that in urban areas. The ratio of rural to urban dimming generally increases from a minimum of 0.39 to a maximum of 0.87 with increasing indices of urbanization calculated based on the year 2013. It reaches a maximum when the urbanization level exceeds 50 %, the urban population exceeds 20 million, or the population density becomes higher than 250 person km−2. After the transition into the leveling-off period, sunshine duration trends are no longer significantly affected by urbanization. Meanwhile, the number of laws and regulations related to air pollution and investment in pollution treatment have been increasing in China.

Operative Duration and Risk of Surgical Site Infection in Neurosurgery.

Science.gov (United States)

Bekelis, Kimon; Coy, Shannon; Simmons, Nathan

2016-10-01

The association of surgical duration with the risk of surgical site infection (SSI) has not been quantified in neurosurgery. We investigated the association of operative duration in neurosurgical procedures with the incidence of SSI. We performed a retrospective cohort study involving patients who underwent neurosurgical procedures from 2005 to 2012 and were registered in the American College of Surgeons National Quality Improvement Project registry. To control for confounding, we used multivariable regression models and propensity score conditioning. During the study period there were 94,744 patients who underwent a neurosurgical procedure and met the inclusion criteria. Of these patients, 4.1% developed a postoperative SSI within 30 days. Multivariable logistic regression showed an association between longer operative duration with higher incidence of SSI (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.16-1.20). Compared with procedures of moderate duration (third quintile, 40th-60th percentile), patients undergoing the longest procedures (>80th percentile) had higher odds (OR, 2.07; 95% CI, 1.86-2.31) of developing SSI. The shortest procedures (operative duration was associated with increased incidence of SSI for neurosurgical procedures. These results can be used by neurosurgeons to inform operative management and to stratify patients with regard to SSI risk. Copyright © 2016 Elsevier Inc. All rights reserved.

Insomnia in patients on hemodialysis for a short versus long duration

Directory of Open Access Journals (Sweden)

Tomita T

2016-09-01

Full Text Available Tetsu Tomita,1 Norio Yasui-Furukori,1 Masaki Oka,1 Takaaki Shimizu,2 Aya Nagashima,2 Kento Mitsuhashi,2 Hisao Saito,3 Kazuhiko Nakamura1 1Department of Neuropsychiatry, Graduate School of Medicine, 2School of Medicine, Hirosaki University, 3Department of Urology, Oyokyo Kidney Research Institute, Hirosaki, Japan Background: Many studies have investigated insomnia and the factors associated with this condition in hemodialysis (HD patients, although the influence of HD duration has not been thoroughly investigated. In the present study, we investigated the factors, especially the duration of HD, associated with insomnia in HD patients.Patients and methods: A total of 138 patients undergoing HD were recruited, and the Japanese version of the Pittsburgh Sleep Quality Index (PSQI was used to assess the quality of sleep. Subjects with a total PSQI score up to 4 and those with a score of at least 5 were identified as normal subjects and subjects with insomnia, respectively. Additionally, we assessed restless legs syndrome, depression using the Center for Epidemiologic Studies Depression Scale, and health-related quality of life (QOL using the Short Form 8 Health Survey. We divided the subjects into two groups according to the median HD duration.Results: The prevalence rate of insomnia was 54.3% among all the subjects. Twenty-one subjects (15.2% had depression, 26 (18.8% had restless legs syndrome, and 75 (54.3% had insomnia. The median HD duration was 4 years. The scores of components 1 and 4 of the PSQI, subjective sleep quality and habitual sleep efficiency, did not show a significant difference between the normal and insomnia groups. The score of component 7, daytime dysfunction, showed a significant difference between the short and long HD duration groups. In multiple regression analysis, the score of the Short Form 8 Health Survey showed a significant association with the PSQI score in the long HD duration group, but no variable showed a

Duration in Production Contracts

OpenAIRE

MacDonald, James M.; Korb, Penelope J.

2006-01-01

We use 2003 and 2004 ARMS data to analyze variations in contract duration among growers of broilers who hold production contracts. Most contracts cover just a single flock, but many extend for 1-2 years, and a significant minority of broiler contracts specify lengths of 5, 10, and even 15 years. We find that grower debt and production volume are inversely related to the choice of a short term (a year or less) contract, while lengthy prior experience with the contractor promotes short term con...

Twelve months of active musical training in 8- to 10-year-old children enhances the preattentive processing of syllabic duration and voice onset time.

Science.gov (United States)

Chobert, Julie; François, Clément; Velay, Jean-Luc; Besson, Mireille

2014-04-01

Musical training has been shown to positively influence linguistic abilities. To follow the developmental dynamics of this transfer effect at the preattentive level, we conducted a longitudinal study over 2 school years with nonmusician children randomly assigned to music or to painting training. We recorded the mismatch negativity (MMN), a cortical correlate of preattentive mismatch detection, to syllables that differed in vowel frequency, vowel duration, and voice onset time (VOT), using a test-training-retest procedure and 3 times of testing: before training, after 6 months and after 12 months of training. While no between-group differences were found before training, enhanced preattentive processing of syllabic duration and VOT, as reflected by greater MMN amplitude, but not of frequency, was found after 12 months of training in the music group only. These results demonstrate neuroplasticity in the child brain and suggest that active musical training rather than innate predispositions for music yielded the improvements in musically trained children. These results also highlight the influence of musical training for duration perception in speech and for the development of phonological representations in normally developing children. They support the importance of music-based training programs for children's education and open new remediation strategies for children with language-based learning impairments.

Speaker-Sex Discrimination for Voiced and Whispered Vowels at Short Durations

OpenAIRE

Smith, David R. R.

2016-01-01

Whispered vowels, produced with no vocal fold vibration, lack the periodic temporal fine structure which in voiced vowels underlies the perceptual attribute of pitch (a salient auditory cue to speaker sex). Voiced vowels possess no temporal fine structure at very short durations (below two glottal cycles). The prediction was that speaker-sex discrimination performance for whispered and voiced vowels would be similar for very short durations but, as stimulus duration increases, voiced vowel pe...

Duration and extent of dysphagia following pediatric airway reconstruction.

Science.gov (United States)

Miller, Claire Kane; Linck, Jessica; Willging, Jay Paul

2009-04-01

Patients who undergo open airway reconstruction procedures are likely to experience some degree of post-operative dysphagia. This retrospective review describes the duration of post-operative dysphagia and the use of compensatory strategies in a group of 30 pediatric patients. A retrospective chart review of pediatric patients referred for post-operative swallowing assessment following airway reconstruction during a six-month period was completed. Age, sex, surgical procedure, stent type, co-morbid factors, duration of dysphagia, and use of compensatory dietary modifications and swallowing strategies was summarized and compared. Dysphagia was generally of short duration (1-5 days) in patients undergoing single stage procedures with anterior or anterior/posterior grafts. Duration of swallowing difficulty was increased in patients undergoing posterior grafts in combination with T tubes (10-14 days). The longest duration of difficulty (>2 weeks) occurred in patients who had anterior and posterior grafting with T tubes, combined with additional procedures such as vocal fold lateralization, epiglottic petiole repositioning, and/or arytenoidectomy. There was a greater likelihood of oral feeding difficulty post-operatively in patients presenting with pre-operative feeding issues such as oral aversion or specific texture refusal, and the pre-morbid need for supplemental tube feeding to supplement oral intake. Compensatory swallowing strategies were effective in decreasing aspiration associated with swallowing in oral feeders post-operatively, and in facilitating return to baseline swallowing skills. The duration of dysphagia overall was increased in patients undergoing anterior/posterior grafts in conjunction with in-dwelling T tubes, especially when combined with additional procedures. Compensatory strategies to assist with swallowing were found to be effective in the post-operative phase and included the use of a modified supraglottic swallowing sequence to assist with

The effects of odor and body posture on perceived duration

NARCIS (Netherlands)

Schreuder, E.; Hoeksma, M.R.; Smeets, M.A.M.; Semin, G.R.

2014-01-01

This study reports an examination of the internal clock model, according to which subjective time duration is influenced by attention and arousal state. In a time production task, we examine the hypothesis that an arousing odor and an upright body posture affect perceived duration. The experimental

Breastfeeding Duration Predicts Greater Maternal Sensitivity over the Next Decade

Science.gov (United States)

Weaver, Jennifer M.; Schofield, Thomas J.; Papp, Lauren M.

2018-01-01

The current study represents the first longitudinal investigation of the potential effects of breastfeeding duration on maternal sensitivity over the following decade. This study also examined whether infant attachment security at 24 months would mediate longitudinal relations between breastfeeding duration and changes in maternal sensitivity over…

Grammatical Aspect in uences Event Duration Estimations: Evidence from Dutch

NARCIS (Netherlands)

Flecken, M.E.P.; Gerwien, J.; Knauff, M.; Pauen, M.; Sebanz, N.; Wachsmuth, I.

2013-01-01

This study investigates the effect of grammatical aspect marking in Dutch sentences, on speakers’ estimations of the duration of highly familiar, everyday events. We first established the ‘inherent’ or natural duration of different events (Exp. 1). This was then used for the manipulation of aspect

Association Between Sleep Duration and Health Outcome in Elderly Taiwanese

Directory of Open Access Journals (Sweden)

Meng-Ting Tsou

2011-12-01

Conclusion: A U-shaped relationship was observed between the self-reported sleep duration with risk prevalence and health outcome in the elderly population, although not all results showed a significant difference. A progressively higher change was observed during short and long sleep durations in our study.

Preliminary project definition for long duration. Tests of coal fired MHD generators

International Nuclear Information System (INIS)

Van der Laken, R.A.

1992-01-01

In its final report the Faraday Working Group recommended the CEC amongst others to explore the possibility of a long duration test of a 'state-of-the-art', MHD-generator in order to remove uncertainties concerning the lifetime and availability of such a generator design. The duration of the test should be several thousands of hours, considerably more than the duration tests carried out until now. The scope of the present study is to prepare a project definition document for a long duration test of a coal fired, state-of-the-art MHD-generator

Do writing and storytelling skill influence assessment of reflective ability in medical students' written reflections?

Science.gov (United States)

Aronson, Louise; Niehaus, Brian; DeVries, Charlie D; Siegel, Jennifer R; O'Sullivan, Patricia S

2010-10-01

Increasingly, students are asked to write reflections as part of their medical education, but some question the influence of other factors on the evaluation of these reflections. In this pilot study, the investigators determined whether scores from a validated rubric to measure reflective ability were affected by irrelevant variance resulting from writing or storytelling ability. Students in clerkships wrote reflections on professionalism. All were given identical prompts, with half receiving additional structured guidelines on reflection. Sixty reflections, 30 from each group, were randomly chosen and scored for reflection, writing, and storytelling by trained raters using validated rubrics. There was no correlation between reflection and either writing (r = 0.049, P = .35) or storytelling (r = 0.14, P = .13). The guidelines increased reflection, but not writing or storytelling scores. Reflection is a distinct construct unaffected by learners' writing or storytelling skills. These findings support reflective ability as a distinct skill.

SHORT-DURATION GAMMA-RAY BURSTS FROM OFF-AXIS COLLAPSARS

International Nuclear Information System (INIS)

Lazzati, Davide; Morsony, Brian J.; Begelman, Mitchell C.

2010-01-01

We present two-dimensional (2D) high-resolution hydrodynamic simulations of the relativistic outflows of long-duration gamma-ray burst (GRB) progenitors. We analyze the properties of the outflows at wide off-axis angles, produced by the expansion of the hot cocoon that surrounds the jet inside the progenitor star. We find that the cocoon emission at wide angles may have properties similar to those of the subclass of short-duration GRBs with persistent X-ray emission. We compute the predicted duration distribution, redshift distribution, and afterglow brightness, and we find that they are all in agreement with the observed properties of short GRBs with persistent emission. We suggest that a supernova component, the properties of the host galaxies, and late afterglow observations can be used as a crucial test to verify this model.

On measuring charged particle bunch duration in linear accelerators

International Nuclear Information System (INIS)

Lomize, L.G.; Malykh, N.I.; Khizhnyj, V.I.; Yampol'skij, E.S.

1977-01-01

The process of measuring short bunches is simulated by means of cavity resonators in which HF fields are excited by both positive and negative ion bunches flying through them. The simulation is aimed to assess optimum operation of a linear accelerator. A set of bunches of chance form and duration is simulated. Then the simulation of the process of restoring the duration and shape of a bunch according to data obtained from a limited number of resonators is realized. The use of 3-4 resonators tuned to 3, 6, 9 and 12-th harmonics of bunch repetition rate is shown to be sufficient for determining bunch duration with an accuracy of several per cent. When data on harmonic phases is available, one can obtain information on beam asymmetry

Association of sleep duration with blood glucose level of Gujarati Indian adolescents.

Science.gov (United States)

Patel, Minal C; Shaikh, Wasim A; Singh, S K

2012-01-01

Recently studies conducted in various parts of the world indicate short sleep duration as a novel risk factor for development of type 2 diabetes. However, ethnic differences exist in the etiopathogenesis of diseases, the current study was undertaken to study the effect of sleep duration on the blood glucose level of Gujarati Indian adolescents. A randomized, non-experimental, cross-sectional study was done on the voluntary participants n = 332 Gujarati adolescent boys and girls of age group 13-20 years studying at the schools and colleges in the Anand district. The participants were assessed for their sleep duration, body composition and blood glucose level. The sleep duration was reported by the subjects as the number of hours they slept on most of the nights in a week over the last one-year. The observations of the study were then analyzed after grouping them into: 1) Adequate sleep duration at night, ASDN (> or = 7 hrs) and 2) Inadequate sleep duration at night, ISDN (blood glucose level between the ASDN group and ISDN group in both boys and girls. However, gender difference exists in the body composition and blood glucose level. The current study indicates that inadequate sleep duration at night (blood glucose level of the Gujarati Indian adolescents of age group 13-20 years.

Characteristics of snow cover duration across the northeast United States of America

Science.gov (United States)

Leathers, Daniel J.; Luff, Barbara L.

1997-11-01

The presence or absence of a snow cover affects a myriad of environmental and societal systems through its modification of the surface radiation balance and its ultimate impact on near-surface air temperatures. Daily snow cover data were collected for a network of 91 stations covering the northeast USA from Maine, south through to West Virginia. The snow cover data along with ancillary temperature, snowfall and precipitation data were used to investigate the characteristics of snow cover duration in this region and the effects of the snow cover on boundary layer climate variables for the snow cover seasons 1948-1949 through to 1987-1988.Results indicate that snow cover duration is variable in both space and time. The duration of a snow cover of 2.5 cm or greater varies from greater than 100 days in northern New England to less than 20 days across areas of Delaware, Maryland and West Virginia. Temporally, snow cover duration for the region as a whole was very short from the late 1940s through to the mid-1950s. From the late 1950s to the end of the period snow cover duration has varied around a consistent mean value. No long-term trends in snow cover duration are apparent in the record for the northeast USA.Principal components analysis and clustering techniques were utilized to isolate spatially coherent regions in which snow cover duration has varied similarly over the period of record. This analysis resulted in the identification of four snow-cover-duration regions across the northeast USA: including (i) the West Virginia area, (ii) the mid-Atlantic from southern New England through to western Pennsylvania, (iii) western and central New York and (iv) northern New England. Snow cover duration is shown to be highly associated with snowfall and temperature but not strongly related to total liquid precipitation. The intra-annual variability of snow cover duration is also investigated for each region.

Duration reproduction with sensory feedback delay: Differential involvement of perception and action time

Directory of Open Access Journals (Sweden)

Stephanie eGanzenmüller

2012-10-01

Full Text Available Previous research has shown that voluntary action can attract subsequent, delayed feedback events towards the action, and adaptation to the sensorimotor delay can even reverse motor-sensory temporal-order judgments. However, whether and how sensorimotor delay affects duration reproduction is still unclear. To investigate this, we injected an onset- or offset-delay to the sensory feedback signal from a duration reproduction task. We compared duration reproductions within (visual, auditory modality and across audiovisual modalities with feedback signal onset- and offset-delay manipulations. We found that the reproduced duration was lengthened in both visual and auditory feedback signal onset-delay conditions. The lengthening effect was evident immediately, on the first trial with the onset delay. However, when the onset of the feedback signal was prior to the action, the lengthening effect was diminished. In contrast, a shortening effect was found with feedback signal offset-delay, though the effect was weaker and manifested only in the auditory offset-delay condition. These findings indicate that participants tend to mix the onset of action and the feedback signal more when the feedback is delayed, and they heavily rely on motor-stop signals for the duration reproduction. Furthermore, auditory duration was overestimated compared to visual duration in crossmodal feedback conditions, and the overestimation of auditory duration (or the underestimation of visual duration was independent of the delay manipulation.

Bond portfolio's duration and investment term-structure management problem

OpenAIRE

Liu, Daobai

2006-01-01

In the considered bond market, there are N zero-coupon bonds transacted continuously, which will mature at equally spaced dates. A duration of bond portfolios under stochastic interest rate model is introduced, which provides a measurement for the interest rate risk. Then we consider an optimal bond investment term-structure management problem using this duration as a performance index, and with the short-term interest rate process satisfying some stochastic differential ...

Noise frame duration, masking potency and whiteness of temporal noise.

Science.gov (United States)

Kukkonen, Heljä; Rovamo, Jyrki; Donner, Kristian; Tammikallio, Marja; Raninen, Antti

2002-09-01

Because of the limited contrast range, increasing the duration of the noise frame is often the only option for increasing the masking potency of external, white temporal noise. This, however, reduces the high-frequency cutoff beyond which noise is no longer white. This study was conducted to determine the longest noise frame duration that produces the strongest masking effect and still mimics white noise on the detection of sinusoidal flicker. Contrast energy thresholds (E(th)) were measured for flicker at 1.25 to 20 Hz in strong, purely temporal (spatially uniform), additive, external noise. The masking power of white external noise, characterized by its spectral density at zero frequency N0, increases with the duration of the noise frame. For short noise frame durations, E(th) increased in direct proportion to N0, keeping the nominal signal-to-noise ratio [SNR = (E(th)/N0)(0.5)] constant at threshold. The masking effect thus increased with the duration of the noise frame and the noise mimicked white noise. When noise frame duration and N0 increased further, the nominal SNR at threshold started to decrease, indicating that noise no longer mimicked white noise. The minimum number of noise frames per flicker cycle needed to mimic white noise decreased with increasing flicker frequency from 8.3 at 1.25 Hz to 1.6 at 20 Hz. The critical high-frequency cutoff of detection-limiting temporal noise in terms of noise frames per signal cycle depends on the temporal frequency of the signal. This is opposite to the situation in the spatial domain and must be taken into consideration when temporal signals are masked with temporal noise.

Relationships between school start time, sleep duration, and adolescent behaviors.

Science.gov (United States)

Wahlstrom, Kyla L; Berger, Aaron T; Widome, Rachel

2017-06-01

The objectives were 2-fold: (1) to examine how high school start times relate to adolescent sleep duration, and (2) to test associations between sleep duration and mental health- and substance use-related issues and behaviors in teens. This study examines selected questions from survey data collected between 2010 and 2013 high school students. Respondents included more than 9000 students in grades 9 to 12 in 8 high schools in 5 school districts across the United States. The survey instrument is the 97-item Teen Sleep Habits Survey. Logistic regression models were used to calculate adjusted odds ratios and 95% confidence intervals. Because of clustering within schools and the use of repeated measures, generalized estimating equations were used to account for variance inflation. Greater sleep duration was associated with fewer reports of various mental health- and substance use-related issues and behaviors (all P values sleep reported, there was a 28% reduction in the adjusted odds of a participant reporting that he or she felt "unhappy, sad, or depressed." Later wake-up times were associated with a reduction in risk for some, but not all factors. Later start times were significantly associated with greater sleep duration. Given that later start times allow for greater sleep duration and that adequate sleep duration is associated with more favorable mental health- and substance use-related issues and behaviors, it is important that school districts prioritize exploring and implementing policies, such as delayed start times, that may increase the amount of sleep of adolescent students, which is needed for their optimal development. Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

Total Breast-Feeding Duration and Dental Caries in Healthy Urban Children.

Science.gov (United States)

Wong, Peter D; Birken, Catherine S; Parkin, Patricia C; Venu, Isvarya; Chen, Yang; Schroth, Robert J; Maguire, Jonathon L

2017-04-01

To determine if there is an association between longer breast-feeding duration and dental caries in healthy urban children. We conducted a cross-sectional study of urban children aged 1 to 6 years recruited through The Applied Research Group for Kids (TARGet Kids!) practice-based research network between September 2011 and August 2013. The main outcome measure was parental report of dental caries. The adjusted predicted probability of dental caries was 7%, 8%, 11%, and 16% with total duration of breast-feeding duration of 12, 18, 24, and 36 months, respectively. In the adjusted logistic regression analyses, relative to breast-feeding 0 to 5 months, the odds of dental caries with total breast-feeding duration >24 months was 2.75 (95% confidence interval 1.61-4.72). Among healthy urban children, longer breast-feeding duration was associated with higher odds of dental caries. These findings support heightened awareness and enhanced anticipatory guidance for preventive dental care, particularly among children who breast-feed beyond 2 years of age. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Association of Sleep Duration with Obesity among US High School Students

Directory of Open Access Journals (Sweden)

Richard Lowry

2012-01-01

Full Text Available Increasing attention is being focused on sleep duration as a potential modifiable risk factor associated with obesity in children and adolescents. We analyzed data from the national Youth Risk Behavior Survey to describe the association of obesity (self-report BMI ≥95th percentile with self-reported sleep duration on an average school night, among a representative sample of US high school students. Using logistic regression to control for demographic and behavioral confounders, among female students, compared to 7 hours of sleep, both shortened (≤4 hours of sleep; adjusted odds ratio (95% confidence interval, AOR = 1.50 (1.05–2.15 and prolonged (≥9 hours of sleep; AOR = 1.54 (1.13–2.10 sleep durations were associated with increased likelihood of obesity. Among male students, there was no significant association between obesity and sleep duration. Better understanding of factors underlying the association between sleep duration and obesity is needed before recommending alteration of sleep time as a means of addressing the obesity epidemic among adolescents.

Effects of annealing temperature and duration on the morphological and optical evolution of self-assembled Pt nanostructures on c-plane sapphire.

Science.gov (United States)

Sui, Mao; Li, Ming-Yu; Kunwar, Sundar; Pandey, Puran; Zhang, Quanzhen; Lee, Jihoon

2017-01-01

Metallic nanostructures (NSs) have been widely adapted in various applications and their physical, chemical, optical and catalytic properties are strongly dependent on their surface morphologies. In this work, the morphological and optical evolution of self-assembled Pt nanostructures on c-plane sapphire (0001) is demonstrated by the control of annealing temperature and dwelling duration with the distinct thickness of Pt films. The formation of Pt NSs is led by the surface diffusion, agglomeration and surface and interface energy minimization of Pt thin films, which relies on the growth parameters such as system temperature, film thickness and annealing duration. The Pt layer of 10 nm shows the formation of overlaying NPs below 650°C and isolated Pt nanoparticles above 700°C based on the enhanced surface diffusion and Volmer-Weber growth model whereas larger wiggly nanostructures are formed with 20 nm thick Pt layers based on the coalescence growth model. The morphologies of Pt nanostructures demonstrate a sharp distinction depending on the growth parameters applied. By the control of dwelling duration, the gradual transition from dense Pt nanoparticles to networks-like and large clusters is observed as correlated to the Rayleigh instability and Ostwald ripening. The various Pt NSs show a significant distinction in the reflectance spectra depending on the morphology evolution: i.e. the enhancement in UV-visible and NIR regions and the related optical properties are discussed in conjunction with the Pt NSs morphology and the surface coverage.

KINEMATICS OF A MECHANISM WITH STOPPINGS, BASED ON A HYPOCYCLOID WITH 6 BRANCHES

Directory of Open Access Journals (Sweden)

Liliana LUCA

2010-10-01

Full Text Available They are studied the positions, velocities and accelerations of a mechanism based on planetary gear and a RRP dyad. The mechanism ensures the plunger stop on a certain subinterval of the cycle, although the leading element is rotating. Because of the approximation of the hypocycloid shortened arc with six branches, by a circle arc, errors occur.

Long Duration Space Shelter Shielding, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Physical Sciences Inc. (PSI) has developed fiber reinforced ceramic composites for radiation shielding that can be used for external walls in long duration manned...

Effects of Short- and Long-Duration Space Flight on Neuromuscular Function

Science.gov (United States)

Buxton, Roxanne E.; Spiering, Barry A.; Ryder, Jeffrey W.; Ploutz-Snyder, Lori L.; Bloomberg, Jacob J.

2010-01-01

The Functional Task Tests (FTT) is an interdisciplinary study designed to correlate the changes in functional tasks (such as emergency egress, ladder climbing, and hatch opening) with changes in neuromuscular, cardiovascular, and sensorimotor function. One aspect of the FTT, the neuromuscular function test, is used to investigate the neuromuscular component underlying changes in the ability of astronauts to perform functional tasks (representative of critical mission tasks) safely and quickly after flight. PURPOSE: To describe neuromuscular function after short- and long-duration space flight. METHODS: To date, 5 crewmembers on short-duration (10- to 15-day) missions and 3 on long-duration missions have participated. Crewmembers were assessed 30 days before flight, on landing day (short-duration subjects only) and 1, 6, and 30 days after landing. The interpolated twitch technique, which utilizes a combination of maximal voluntary contractions and electrically evoked contractions, was used to assess the maximal voluntary isometric force (MIF) and central activation capacity of the knee extensors. Leg-press and bench-press devices were used to assess MIF and maximal dynamic power of the lower and upper body respectively. Specifically, power was measured during concentric-only ballistic throws of the leg-press sled and bench-press bar loaded to 40% and 30% of MIF respectively. RESULTS: Data are currently being collected from both Shuttle and ISS crewmembers. Emerging data indicate that measures of knee extensor muscle function are decreased with long-duration flight. DISCUSSION: The relationships between flight duration, neural drive, and muscle performance are of particular interest. Ongoing research will add to the current sample size and will focus on defining changes in muscle performance measures after long-duration space flight.

Near zero reflection by nanostructured anti-reflection coating design for Si substrates

Science.gov (United States)

Al-Fandi, Mohamed; Makableh, Yahia F.; Khasawneh, Mohammad; Rabady, Rabi

2018-05-01

The nanostructure design of near zero reflection coating for Si substrates by using ZnO Nanoneedles (ZnONN) is performed and optimized for the visible spectral range. The design investigates the ZnONN tip to body ratio effect on the anti-reflection coating properties. Different tip to body ratios are used on Si substrates. Around zero reflection is achieved by the Nanoneedles structure design presented in this work, leading to minimal reflection losses from the Si surface. The current design evolves a solution to optical losses and surface contamination effects associated with Si solar cells.

Behavioral Profiles Associated with Objective Sleep Duration in Young Children with Insomnia Symptoms.

Science.gov (United States)

Calhoun, Susan L; Fernandez-Mendoza, Julio; Vgontzas, Alexandros N; Mayes, Susan D; Liao, Duanping; Bixler, Edward O

2017-02-01

Based on previous studies reporting on the association of objective sleep duration and physiologic changes (i.e., increased cortisol) in children, we examined the role of objective sleep duration on differentiating behavioral profiles in children with insomnia symptoms. Seven hundred children (ages 5-12, 47.8% male) from the Penn State Child Cohort underwent a nine-hour polysomnography and parent completed Pediatric Behavior Scale. Insomnia symptoms were defined as parent report of difficulty falling and/or staying asleep, sleep disordered breathing as an AHI of ≥1, and objective short sleep duration as a total sleep time insomnia symptoms demonstrated more overall behavioral problems than controls. Significant interactions between insomnia symptoms and objective sleep duration on scores of externalizing behaviors, mood variability and school problems were found. Profile analyses showed that children with insomnia symptoms and normal sleep duration were associated with clinically elevated externalizing behaviors, inattention, mood variability, and school problems, while children with insomnia and short sleep duration were associated with an overall elevated profile in which internalizing behaviors were more prominent. Childhood insomnia symptoms are associated with a wide array of behavioral problems, for which objective sleep duration is useful in differentiating behavioral profiles. Children with insomnia symptoms and normal sleep duration had a behavioral profile consistent with limit-setting and rule-breaking behaviors, while children with insomnia symptoms and short sleep duration had a behavioral profile more consistent with internalizing behaviors resembling that of psychophysiological disorders.

Reliability-Based Modeling of Moisture and Load-Duration Effects

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Svensson, Staffan

2005-01-01

Load duration effects with respect to reduction of load bearing capacity are very important for structural timber. This paper describes how the load duration effects combined with moisture content and variations c an be determined on basis of simulation of realizations of the time varying load...... and moisture processes. Permanent and snow load sand moisture variations are considered and stochastic models are formulated in accordance with the load models in the Danish structural codes. A damage accumulation model based on fracture mechanics that accounts for both load duration and moisture effects...... is derived. The parameters in the model are fitted to data relevant for Nordic structural timber using the Maximum Likelihood method. The probability of failure as function of time is estimated for representative limit states based on: a) short term strength and b) long term damage accumulation...

Application of the specular and diffuse reflection analysis for in vitro diagnostics of dental erosion: correlation with enamel softening, roughness, and calcium release

Science.gov (United States)

Rakhmatullina, Ekaterina; Bossen, Anke; Höschele, Christoph; Wang, Xiaojie; Beyeler, Barbara; Meier, Christoph; Lussi, Adrian

2011-10-01

We present assembly and application of an optical reflectometer for the analysis of dental erosion. The erosive procedure involved acid-induced softening and initial substance loss phases, which are considered to be difficult for visual diagnosis in a clinic. Change of the specular reflection signal showed the highest sensitivity for the detection of the early softening phase of erosion among tested methods. The exponential decrease of the specular reflection intensity with erosive duration was compared to the increase of enamel roughness. Surface roughness was measured by optical analysis, and the observed tendency was correlated with scanning electron microscopy images of eroded enamel. A high correlation between specular reflection intensity and measurement of enamel softening (r2 >= -0.86) as well as calcium release (r2 >= -0.86) was found during erosion progression. Measurement of diffuse reflection revealed higher tooth-to-tooth deviation in contrast to the analysis of specular reflection intensity and lower correlation with other applied methods (r2 = 0.42-0.48). The proposed optical method allows simple and fast surface analysis and could be used for further optimization and construction of the first noncontact and cost-effective diagnostic tool for early erosion assessment in vivo.

Production and Perception of Distortion in Word-Initial Friction Duration

Science.gov (United States)

Jovicic, Slobodan T.; Kasic, Zorca; Punisic, Silvana

2010-01-01

The purpose of the present study was to investigate (a) the distortion in production of word-initial friction duration in fricative /[esh]/, and (b) the perceptual discrimination between typical (normal) and atypical (prolonged or lengthened) friction duration. In the first experiment 80 school aged children pronounced word /[esh]uma/, 40 of them…

Postgraduate Education to Support Organisation Change: A Reflection on Reflection

Science.gov (United States)

Stewart, Jim; Keegan, Anne; Stevens, Pam

2008-01-01

Purpose: This paper aims to explore how teaching and assessing reflective learning skills can support postgraduate practitioners studying organisational change and explores the challenges for tutors in assessing these journals. Design/methodology/approach: Assessment criteria were developed from the literature on reflective practice and…

PSA Duration: Conquering the Prepayment Risk of Mortgage Portfolios

OpenAIRE

Boleslav Gulko

1996-01-01

Money managers have little control over the values of their individual holdings, but they have considerable control over the risk exposure of their portfolios. This article introduces new tools for the risk management of mortgage portfolios. We extend the traditional duration analysis to two dimensions, interest rates and mortgage prepayments, and develop independent hedging rules for the interest rate risk and the prepayment risk. In particular, we define the PSA duration as a formal measure...

Formation of plasmonic silver nanoparticles using rapid thermal annealing at low temperature and study in reflectance reduction of Si surface

Science.gov (United States)

Barman, Bidyut; Dhasmana, Hrishikesh; Verma, Abhishek; Kumar, Amit; Pratap Chaudhary, Shiv; Jain, V. K.

2017-09-01

This work presents studies of plasmonic silver nanoparticles (AgNPs) formation at low temperatures (200 °C-300 °C) onto Si surface by sputtering followed with rapid thermal processing (RTP) for different time durations(5-30 min). The study reveals that 20 min RTP at all temperatures show minimum average size of AgNPs (60.42 nm) with corresponding reduction in reflectance of Si surface from 40.12% to mere 1.15% only in wavelength region 300-800 nm for RTP at 200 °C. A detailed supporting growth mechanism is also discussed. This low temperature technique can be helpful in achieving efficiency improvement in solar cells via reflectance reduction with additional features such as reproducibility, minimal time and very good adhesion without damaging underlying layers device parameters.

Loss aversion and duration of residence

Directory of Open Access Journals (Sweden)

Philip S. Morrison

2016-10-01

Full Text Available Background: Studies of internal migration ask who moves, why they move, and what are the consequences - to themselves, their origin, and their destination. By contrast, studies of those who stay for very long durations are less common, despite the fact that most people move relatively infrequently. Objective: We argue that staying is the dominant, preferred state and that moving is simply an adjustment toward a desired state of stability (or equilibrium. The core of our argument, already recognized in the literature, is that migration is risky. However, we extend the argument to loss aversion as developed within prospect theory. Prospect theory posits that existing possessions, including the dwelling and existing commodities, are attributed a value well beyond their purchase price and that this extends the average period of staying among the loss-averse. Methods: Applying prospect theory has several challenges, including measurement of the reference point and potential degrees of gain and loss households face in deciding to change residence, as well as their own degree of loss aversion. The growing number of large panel sets should make it possible to estimate the degree to which endowment effects are likely to extend durations of residence as predicted by prospect theory. Conclusions: Rational expectations models of mobility focus on the changes in the level of consumption of residential services. By contrast, prospect theory focuses on potential gains and losses relative to the existing dwelling - the reference point. As we confront increasing durations of residence in contemporary society, an application of prospect theory is likely to yield important advantages over existing models of mobility and staying.

Sequential fitting-and-separating reflectance components for analytical bidirectional reflectance distribution function estimation.

Science.gov (United States)

Lee, Yu; Yu, Chanki; Lee, Sang Wook

2018-01-10

We present a sequential fitting-and-separating algorithm for surface reflectance components that separates individual dominant reflectance components and simultaneously estimates the corresponding bidirectional reflectance distribution function (BRDF) parameters from the separated reflectance values. We tackle the estimation of a Lafortune BRDF model, which combines a nonLambertian diffuse reflection and multiple specular reflectance components with a different specular lobe. Our proposed method infers the appropriate number of BRDF lobes and their parameters by separating and estimating each of the reflectance components using an interval analysis-based branch-and-bound method in conjunction with iterative K-ordered scale estimation. The focus of this paper is the estimation of the Lafortune BRDF model. Nevertheless, our proposed method can be applied to other analytical BRDF models such as the Cook-Torrance and Ward models. Experiments were carried out to validate the proposed method using isotropic materials from the Mitsubishi Electric Research Laboratories-Massachusetts Institute of Technology (MERL-MIT) BRDF database, and the results show that our method is superior to a conventional minimization algorithm.

Subjective sleep quality and sleep duration of patients in a psychiatric hospital

Directory of Open Access Journals (Sweden)

Matthias J. Müller

2016-07-01

Full Text Available Sleep complaints and sleep disturbances are highly prevalent in patients with psychiatric disorders. During hospitalization the patients’ condition may be even worse but little is known about the subjective sleep quality in psychiatric hospitals. Thus, we have investigated subjective sleep quality and mean sleep duration in patients with different psychiatric disorders at the end of hospitalization. For a period of one year, inpatients of a psychiatric hospital with diagnosis of substance use disorder (SUD, schizophrenia (SCZ, or anxiety/depressive disorders (AND were routinely asked to fill in an easily comprehensible sleep quality questionnaire at the end of their hospitalization. Age, gender, subjective sleep quality, and sleep duration were analyzed; sleep duration was classified according to age-specific recommendations. Data of n=309 patients (age 52.1±17.9y, 56.1% women were analyzed (n=63 SUD, n=50 SCZ, n=196 AND. Mean sleep duration was 7.0±2.0 h; 20.7% of patients had sleep durations below and 4.5% above age-specific recommendations. Non-restorative sleep during hospitalization was reported “almost always” in 38.2% (n=118, and “occasionally” in 30.1% (n=93. Subjective sleep quality was significantly associated with sleep duration (rs=−0.31, P<0.0005, but not with age, gender or diagnostic subgroup. The study showed that a great proportion of patients reported poor subjective sleep quality during hospitalization, regardless of age, gender and psychiatric diagnosis. As sleep quality was significantly associated with short sleep duration, a first step could be to take care to achieve recommended age-specific sleep durations in psychiatric hospitals.

Caffeine consumption, insomnia, and sleep duration: Results from a nationally representative sample.

Science.gov (United States)

Chaudhary, Ninad S; Grandner, Michael A; Jackson, Nicholas J; Chakravorty, Subhajit

2016-01-01

Insomnia symptoms have been individually associated with both caffeine consumption and sleep duration abnormalities in prior studies. The goal of this study was to determine whether caffeine consumption was associated with insomnia symptoms from a population perspective and whether this relationship depended on habitual sleep duration. Data were extracted from the 2007-2008 National Health and Nutritional Examination Survey (N = 4730). Caffeine consumption was quantified as mg/d from 2 typical days of use, 7 to 10 d apart. Insomnia symptoms were evaluated using frequencies of difficulty falling asleep (DFA), difficulty staying asleep (DSA), non-restorative sleep (NRS), and daytime sleepiness (DS). Habitual sleep duration was assessed as the hours of sleep obtained on a typical night. Binomial logistic regression analysis evaluated the relationships of individual insomnia and sleepiness symptoms (DFA, DSA, NRS, and DS) with caffeine consumption and sleep duration variables, after adjusting for covariates. The mean ± SD caffeine consumption was 176.6 ± 201 mg/d. Mean habitual sleep duration was 6.8 ± 1.4 h. Insomnia symptoms were prevalent in 19.1% to 28.4% of the respondents. Although caffeine consumption was associated with all insomnia symptoms in the unadjusted models, the adjusted models demonstrated a trend toward significance with DSA. Sleep duration was inversely associated with the insomnia symptoms in unadjusted and adjusted analysis. Finally, NRS was associated with an interaction between increased caffeine consumption and sleep duration. The association between caffeine use and insomnia symptoms depends on habitual sleep duration at a population level. Copyright © 2016 Elsevier Inc. All rights reserved.

The Limited Impact of Exposure Duration on Holistic Word Processing.

Science.gov (United States)

Chen, Changming; Abbasi, Najam Ul Hasan; Song, Shuang; Chen, Jie; Li, Hong

2016-01-01

The current study explored the impact of stimuli exposure duration on holistic word processing measured by the complete composite paradigm (CPc paradigm). The participants were asked to match the cued target parts of two characters which were presented for either a long (600 ms) or a short duration (170 ms). They were also tested by two popular versions of the CPc paradigm: the "early-fixed" task where the attention cue was visible from the beginning of each trial at a fixed position, and the "delayed-random" task where the cue showed up after the study character at random locations. The holistic word effect, as indexed by the alignment × congruency interaction, was identified in both tasks and was unaffected by the stimuli duration in both tasks. Meanwhile, the "delayed-random" task did not bring about larger holistic word effect than the "early-fixed" task. These results suggest the exposure duration (from around 150 to 600 ms) has a limited impact on the holistic word effect, and have methodological implications for experiment designs in this field.

Characteristics of Epileptiform Discharge Duration and Interdischarge Interval in Genetic Generalized Epilepsies

Directory of Open Access Journals (Sweden)

Udaya Seneviratne

2018-02-01

Full Text Available We sought to investigate (1 the characteristics of epileptiform discharge (ED duration and interdischarge interval (IDI and (2 the influence of vigilance state on the ED duration and IDI in genetic generalized epilepsy (GGE. In a cohort of patients diagnosed with GGE, 24-h ambulatory EEG recordings were performed prospectively. We then tabulated durations, IDI, and vigilance state in relation to all EDs captured on EEGs. We used K-means cluster analysis and finite mixture modeling to quantify and characterize the groups of ED duration and IDI. To investigate the influence of sleep, we calculated the mean, median, and SEM in each population from all subjects for sleep state and wakefulness separately, followed by the Kruskal–Wallis test to compare the groups. We analyzed 4,679 EDs and corresponding IDI from 23 abnormal 24-h ambulatory EEGs. Our analysis defined two populations of ED durations and IDI: short and long. In all populations, both ED durations and IDI were significantly longer in wakefulness. Our results highlight different characteristics of ED populations in GGE and the influence by the sleep–wake cycle.

Examining Hurricane Track Length and Stage Duration Since 1980

Science.gov (United States)

Fandrich, K. M.; Pennington, D.

2017-12-01

Each year, tropical systems impact thousands of people worldwide. Current research shows a correlation between the intensity and frequency of hurricanes and the changing climate. However, little is known about other prominent hurricane features. This includes information about hurricane track length (the total distance traveled from tropical depression through a hurricane's final category assignment) and how this distance may have changed with time. Also unknown is the typical duration of a hurricane stage, such as tropical storm to category one, and if the time spent in each stage has changed in recent decades. This research aims to examine changes in hurricane stage duration and track lengths for the 319 storms in NOAA's National Ocean Service Hurricane Reanalysis dataset that reached Category 2 - 5 from 1980 - 2015. Based on evident ocean warming, it is hypothesized that a general increase in track length with time will be detected, thus modern hurricanes are traveling a longer distance than past hurricanes. It is also expected that stage durations are decreasing with time so that hurricanes mature faster than in past decades. For each storm, coordinates are acquired at 4-times daily intervals throughout its duration and track lengths are computed for each 6-hour period. Total track lengths are then computed and storms are analyzed graphically and statistically by category for temporal track length changes. The stage durations of each storm are calculated as the time difference between two consecutive stages. Results indicate that average track lengths for Cat 2 and 3 hurricanes are increasing through time. These findings show that these hurricanes are traveling a longer distance than earlier Cat 2 and 3 hurricanes. In contrast, average track lengths for Cat 4 and 5 hurricanes are decreasing through time, showing less distance traveled than earlier decades. Stage durations for all Cat 2, 4 and 5 storms decrease through the decades but Cat 3 storms show a

Psychophysiology of duration estimation in experienced mindfulness meditators and matched controls

Directory of Open Access Journals (Sweden)

Simone eOtten

2015-08-01

Full Text Available Recent research suggests that bodily signals and interoception are strongly related to our sense of time. Mindfulness meditators train to be aware of their body states and therefore could be more accurate at interval timing. In this study, n = 22 experienced mindfulness meditators and n = 22 matched controls performed both, an acoustic and a visual duration reproduction task of 8 s, 14s and 20s intervals, while heart rate and skin conductance were continuously assessed. In addition, participants accomplished a heart-beat perception task and two selective attention tasks. Results revealed no differences between meditators and controls with respect to performance in duration reproduction or attentional capacities. Additionally no group difference in heart beat perception scores was found. Across all subjects, correlational analyses revealed several associations between performance in the duration reproduction tasks and psychophysiological changes, the latter being also related to heart beat perception scores. Furthermore, former findings of linearly increasing cardiac periods and decreasing skin conductance levels during the auditory duration estimation task (Meissner and Wittmann, 2011 could be replicated, and these changes could also be observed during a visual duration reproduction task. In contrast to our earlier findings, the heart-beat perception test was not related with timing performance. Overall, although experienced meditators did not differ from matched controls with respect to duration reproduction and interoceptive awareness, this study adds significantly to the emerging view that time perception is related to autonomic regulation and awareness of body states.

Reflection and Reflective Practice Discourses in Coaching: A Critical Analysis

Science.gov (United States)

Cushion, Christopher J.

2018-01-01

Reflection and reflective practice is seen as an established part of coaching and coach education practice. It has become a "taken-for-granted" part of coaching that is accepted enthusiastically and unquestioningly, and is assumed to be "good" for coaching and coaches. Drawing on sociological concepts, a primarily Foucauldian…

Sleep duration in elderly obese patients correlated negatively with intake fatty

Directory of Open Access Journals (Sweden)

Santana Aline

2012-08-01

Full Text Available Abstract Study objectives The purpose of the present study was to evaluate the relationship between sleep duration and dietary habits in elderly obese patients treated at an institute of cardiology. Methods The fifty-eight volunteers were elderly patients with obesity (classified as obese according to BMI of both genders, between 60 and 80 years of age. All participants were subjected to assessments of food intake, anthropometry, level of physical activity, and duration of sleep. Results The men had significantly greater weight, height, and waist circumference than women. Sleep durations were correlated with dietary nutrient compositions only in men. We found a negative association between short sleep and protein intake (r = -0.43; p = 0.02, short sleep and monounsaturated fatty acids intake (r = -0.40; p = 0.03, and short sleep and cholesterol dietary intake (r = -0.50; p = 0.01. Conclusions We conclude that mainly in men, volunteers that had short sleep duration showed a preference for high energy-density as fatty food, at least in part, may explain the relationship between short sleep duration and the development of metabolic abnormalities.

Understanding social capital in sports clubs: participation, duration and social trust

DEFF Research Database (Denmark)

Elmose-Østerlund, Karsten; Van der Roest, Jan-Willem

2017-01-01

A central claim in Robert Putnam’s theory of social capital is that participation in voluntary organizations can foster social trust among members that are active and engaged. Based on this claim, this article examines how duration of membership and member participation impacts upon levels...... of social trust among sports club members. The results show that neither participation nor duration impacts on levels of social trust – a result found in survey studies conducted in Denmark and the Netherlands. Sophisticated participation measures and the inclusion of duration of membership set this study...... apart from previous studies on social capital. The fact that no correlation can be identified between participation and duration on one side and social trust on the other adds weight to the claim that, even though numerous studies find higher levels of social trust among members of voluntary...

The effects of core-reflected waves on finite fault inversions with teleseismic body wave data

Science.gov (United States)

Qian, Yunyi; Ni, Sidao; Wei, Shengji; Almeida, Rafael; Zhang, Han

2017-11-01

Teleseismic body waves are essential for imaging rupture processes of large earthquakes. Earthquake source parameters are usually characterized by waveform analyses such as finite fault inversions using only turning (direct) P and SH waves without considering the reflected phases from the core-mantle boundary (CMB). However, core-reflected waves such as ScS usually have amplitudes comparable to direct S waves due to the total reflection from the CMB and might interfere with the S waves used for inversion, especially at large epicentral distances for long duration earthquakes. In order to understand how core-reflected waves affect teleseismic body wave inversion results, we develop a procedure named Multitel3 to compute Green's functions that contain turning waves (direct P, pP, sP, direct S, sS and reverberations in the crust) and core-reflected waves (PcP, pPcP, sPcP, ScS, sScS and associated reflected phases from the CMB). This ray-based method can efficiently generate synthetic seismograms for turning and core-reflected waves independently, with the flexibility to take into account the 3-D Earth structure effect on the timing between these phases. The performance of this approach is assessed through a series of numerical inversion tests on synthetic waveforms of the 2008 Mw7.9 Wenchuan earthquake and the 2015 Mw7.8 Nepal earthquake. We also compare this improved method with the turning-wave only inversions and explore the stability of the new procedure when there are uncertainties in a priori information (such as fault geometry and epicentre location) or arrival time of core-reflected phases. Finally, a finite fault inversion of the 2005 Mw8.7 Nias-Simeulue earthquake is carried out using the improved Green's functions. Using enhanced Green's functions yields better inversion results as expected. While the finite source inversion with conventional P and SH waves is able to recover large-scale characteristics of the earthquake source, by adding PcP and ScS phases

Obtaining local reflectivity at two-way travel time by filtering acoustic reflection data

NARCIS (Netherlands)

Slob, E.C.; Zhang, L.; Wapenaar, C.P.A.; Mihai Popovici, A.; Fomel, S.

2017-01-01

A modified implementation of Marchenko redatuming leads to a filter that removes internal multiples from reflection data. It produces local reflectivity at two-way travel time. The method creates new primary reflections resulting from emitted events that eliminate internal multiples. We call these

Hours of television viewing and sleep duration in children: a multicenter birth cohort study.

Science.gov (United States)

Marinelli, Marcella; Sunyer, Jordi; Alvarez-Pedrerol, Mar; Iñiguez, Carmen; Torrent, Maties; Vioque, Jesús; Turner, Michelle C; Julvez, Jordi

2014-05-01

This study used longitudinal data to examine potential associations between hours of television viewing and sleep duration in children. To examine the association between hours of television viewing and sleep duration in preschool and school-aged children. Longitudinal, multicenter study among birth cohorts in Menorca, Sabadell, and Valencia from the Spanish Infancia y Medio Ambiente (environment and childhood) project. The study sample included 1713 children (468 from Menorca, 560 from Sabadell, and 685 from Valencia). Parent-reported child television viewing duration measured in hours per day at 2 and 4 years of age in Sabadell and Valencia and at 6 and 9 years of age in Menorca. Parent-reported child sleep duration measured in hours per day at 2 and 4 years of age in Sabadell and Valencia and at 6 and 9 years of age in Menorca. In cross-sectional analysis, children with longer periods of television viewing reported at baseline (≥ 1.5 hours per day) had shorter sleep duration. Longitudinally, children with reported increases in television viewing duration over time (from <1.5 to ≥ 1.5 hours per day) had a reduction in sleep duration at follow-up visits. Results were similar when examining television viewing duration as a continuous variable, with each 1 hour per day of increased viewing decreasing sleep duration at follow-up visits (β = -0.11; 95% CI, -0.18 to -0.05). Associations were similar when television viewing duration was assessed during weekends and after adjusting for potential intermediate factors (child executive function and attention-deficit/hyperactivity disorder symptoms) and confounders (child physical activity level, parental mental health status, maternal IQ, and maternal marital status). Children spending longer periods watching television had shorter sleep duration. Changes in television viewing duration were inversely associated with changes in sleep duration in longitudinal analysis. Parents should consider avoiding long periods of

Influence of median surgeon operative duration on adverse outcomes in bariatric surgery.

Science.gov (United States)

Reames, Bradley N; Bacal, Daniel; Krell, Robert W; Birkmeyer, John D; Birkmeyer, Nancy J O; Finks, Jonathan F

2015-01-01

Evidence suggests that prolonged operative time adversely affects surgical outcomes. However, whether faster surgeons have better outcomes is unclear, as a surgeon׳s speed could reflect skill and efficiency, but may alternatively reflect haste. This study evaluates whether median surgeon operative time is associated with adverse surgical outcomes after laparoscopic Roux-en-Y gastric bypass. We performed a retrospective cohort study using statewide clinical registry data from the years 2006 to 2012. Surgeons were ranked by their median operative time and grouped into terciles. Multivariable logistic regression with robust standard errors was used to evaluate the influence of median surgeon operative time on 30-day surgical outcomes, adjusting for patient and surgeon characteristics, trainee involvement, concurrent procedures, and the complex interaction between these variables. A total of 16,344 patients underwent surgery during the study period. Compared to surgeons in the fastest tercile, slow surgeons required 53 additional minutes to complete a gastric bypass procedure (median [interquartile range] 139 [133-150] versus 86 [69-91], Ppatient characteristic only, slow surgeons had significantly higher adjusted rates of any complication, prolonged length of stay, emergency department visits or readmissions, and venous thromboembolism (VTE). After further adjustment for surgeon characteristics, resident involvement, and the interaction between these variables, slow surgeons had higher rates of any complication (10.5% versus 7.1%, P=.039), prolonged length of stay (14.0% versus 4.4%, P=.002), and VTE (0.39% versus .22%, P<.001). Median surgeon operative duration is independently associated with adjusted rates of certain adverse outcomes after laparoscopic Roux-en-Y gastric bypass. Improving surgeon efficiency while operating may reduce operative time and improve the safety of bariatric surgery. Copyright © 2015 American Society for Bariatric Surgery. Published by

Reflective Practices for Teacher Education

Directory of Open Access Journals (Sweden)

Paulus Kuswandono

2017-01-01

Full Text Available Studies on reflective practice in teacher education are increasingly getting more attention at least in the last 2 decades. This article discusses concepts of reflection and how it is implemented in educating pre-service teachers on their early stage of professional learning. The purposes of doing the reflection for pre-service teachers are not only for illuminating their professional learning experiences, but also to critically reflect their vocation as teachers, including the values which may be dictated to them through rigid regulations. Reflection in teacher education is crucial as it connects well with learning in that learners use reflection to exercise their mind and to evaluate their learning experiences. Besides, this article also highlights some perceived difficulties to implement reflective practice, as well as ways how to promote reflection.   DOI: https://doi.org/10.24071/llt.2012.150102

Seismic reflection response from cross-correlations of ambient vibrations on non-conventional hidrocarbon reservoir

Science.gov (United States)

Huerta, F. V.; Granados, I.; Aguirre, J.; Carrera, R. Á.

2017-12-01

Nowadays, in hydrocarbon industry, there is a need to optimize and reduce exploration costs in the different types of reservoirs, motivating the community specialized in the search and development of alternative exploration geophysical methods. This study show the reflection response obtained from a shale gas / oil deposit through the method of seismic interferometry of ambient vibrations in combination with Wavelet analysis and conventional seismic reflection techniques (CMP & NMO). The method is to generate seismic responses from virtual sources through the process of cross-correlation of records of Ambient Seismic Vibrations (ASV), collected in different receivers. The seismic response obtained is interpreted as the response that would be measured in one of the receivers considering a virtual source in the other. The acquisition of ASV records was performed in northern of Mexico through semi-rectangular arrays of multi-component geophones with instrumental response of 10 Hz. The in-line distance between geophones was 40 m while in cross-line was 280 m, the sampling used during the data collection was 2 ms and the total duration of the records was 6 hours. The results show the reflection response of two lines in the in-line direction and two in the cross-line direction for which the continuity of coherent events have been identified and interpreted as reflectors. There is certainty that the events identified correspond to reflections because the time-frequency analysis performed with the Wavelet Transform has allowed to identify the frequency band in which there are body waves. On the other hand, the CMP and NMO techniques have allowed to emphasize and correct the reflection response obtained during the correlation processes in the frequency band of interest. The results of the processing and analysis of ASV records through the seismic interferometry method have allowed us to see interesting results in light of the cross-correlation process in combination with

Catheter based mid-infrared reflectance and reflectance generated absorption spectroscopy

Science.gov (United States)

Holman, Hoi-Ying N

2013-10-29

A method of characterizing conditions in a tissue, by (a) providing a catheter that has a light source that emits light in selected wavenumbers within the range of mid-IR spectrum; (b) directing the light from the catheter to an area of tissue at a location inside a blood vessel of a subject; (c) collecting light reflected from the location and generating a reflectance spectra; and (d) comparing the reflectance spectra to a reference spectra of normal tissue, whereby a location having an increased number of absorbance peaks at said selected wavenumbers indicates a tissue inside the blood vessel containing a physiological marker for atherosclerosis.

Sunshine Duration Variability in Haihe River Basin, China, during 1966–2015

Directory of Open Access Journals (Sweden)

Jing Ren

2017-10-01

Full Text Available Sunshine can have a profound impact on the systematic change in climate elements, such as temperature and wind speed, and in turn affects many aspects of the human society. In recent years, there has been a substantial interest in the variation of sunshine duration due to the dramatic global climate change. Hence, there is a need to better understand the variation of sunshine duration in order to cope with climate change. This study aimed to analyze the variation of sunshine duration in Haihe River basin, China, and its relationship with temperature, wind speed and low-level cloudiness. The annual, seasonal and monthly changes of sunshine duration were analyzed based on the data collected from 33 meteorological stations over the Haihe River basin during 1966–2015. It is evident that the annual, seasonal and monthly sunshine duration shows a decreasing trend over time. In addition, the annual sunshine duration is lower with a higher climate tendency rate in the southern and eastern coastal regions than that in the northwestern regions. It is negatively correlated with temperature (r = −0.50 and low-level cloudiness (r = −0.29, but positively with wind speed (r = 0.61. Wind speed may be one of the important causes of the decrease of sunshine duration in the Haihe River basin during 1966–2015. These changes may have significant implications for the hydrological cycle in the area.

Studies of the Reflection, Refraction and Internal Reflection of Light

Science.gov (United States)

Lanchester, P. C.

2014-01-01

An inexpensive apparatus and associated experiments are described for studying the basic laws of reflection and refraction of light at an air-glass interface, and multiple internal reflections within a glass block. In order to motivate students and encourage their active participation, a novel technique is described for determining the refractive…

Self-rumination, self-reflection, and depression: self-rumination counteracts the adaptive effect of self-reflection.

Science.gov (United States)

Takano, Keisuke; Tanno, Yoshihiko

2009-03-01

Self-focused attention has adaptive and maladaptive aspects: self-reflection and self-rumination [Trapnell, P. D., & Campbell, J. D. (1999). Private self-consciousness and the Five-Factor Model of personality: distinguishing rumination from reflection. Journal of Personality and Social Psychology, 76, 284-304]. Although reflection is thought to be associated with problem solving and the promotion of mental health, previous researches have shown that reflection does not always have an adaptive effect on depression. Authors have examined the causes behind this inconsistency by modeling the relationships among self-reflection, self-rumination, and depression. One hundred and eleven undergraduates (91 men and 20 women) participated in a two-time point assessment with a 3-week interval. Statistical analysis with structural equation modeling showed that self-reflection significantly predicted self-rumination, whereas self-rumination did not predict self-reflection. With regard to depression, self-reflection was associated with a lower level of depression; self-rumination, with a higher level of depression. The total effect of self-reflection on depression was almost zero. This result indicates that self-reflection per se has an adaptive effect, which is canceled out by the maladaptive effect of self-rumination, because reflectors are likely to ruminate and reflect simultaneously.

The duration perception of loading applications in smartphone: Effects of different loading types.

Science.gov (United States)

Zhao, Wenguo; Ge, Yan; Qu, Weina; Zhang, Kan; Sun, Xianghong

2017-11-01

The loading time of a smartphone application is an important issue, which affects the satisfaction of phone users. This study evaluated the effects of black loading screen (BLS) and animation loading screen (ALS) during application loading on users' duration perception and satisfaction. A total of 43 volunteers were enrolled. They were asked to complete several tasks by clicking the icons of each application, such as camera or message. The duration of loading time for each application was manipulated. The participants were asked to estimate the duration, evaluate the loading speed and their satisfaction. The results showed that the estimated duration increased and the satisfaction for loading period declined along with the loading time increased. Compared with the BLS, the ALS prolonged the estimated duration, and lowered the evaluation of speed and satisfaction. We also discussed the tendency and key inflection points of the curves involving the estimated duration, speed evaluation and satisfaction with the loading time. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Sleep, work, and study: sleep duration in working and non-working students].

Science.gov (United States)

Pereira, Erico Felden; Bernardo, Maria Perpeto Socorro Leite; D'Almeida, Vânia; Louzada, Fernando Mazzilli

2011-05-01

The aim of this study was to investigate the duration of sleep and associated factors in working and non-working students. Data were analyzed on the sleep-wake cycle in 863 teenage students in São Paulo, Brazil. Adjusted analyses were performed to compare sleep duration in working and non-working students. 18.4% of the group worked, and 52% of the working students slept eight hours or less per night. Prevalence of short sleep duration was higher in working students of both sexes (males, p = 0.017; females, p Working students showed short sleep duration in the analysis adjusted for socioeconomic status, but short sleep was more frequent in older adolescents (p = 0.004) and in lower (p = 0.001) and middle (p = 0.011) socioeconomic classes. Although more working students were in night school, in the model adjusted for gender and socioeconomic status, working students in afternoon courses showed higher prevalence of short sleep duration (PR = 2.53; 95%CI: 1.68-4.12).

[Sleep duration and functional limitations in older adult].

Science.gov (United States)

Eumann Mesas, Arthur; López-García, Esther; Rodríguez-Artalejo, Fernando

2011-04-30

To examine the association between sleep duration and functional limitation in older adults from Spain. Cross-sectional study with 3,708 individuals representative of the non-institutionalized population aged ≥ 60 years in Spain. Sleep duration was self-reported, and the functional limitations in the instrumental activities of daily living (IADL) were assessed. Functional limitations in IADL were identified in 1,424 (38.4%) participants. In analyses adjusted for sociodemographic and lifestyle variables, the percentage of participants with limitation in IADL was higher in those who slept ≤ 5 hours (odds ratio [OR]=1.56; 95% confidence interval [CI]=1.18-2.06) or ≥ 10 hours (OR=2.08; 95%CI=1.67-2.60; p for trendlimitations held even after adjustment for comorbidity and sleep quality (OR=1.77; 95%CI=1.38-2.28) while the association between short sleep (≤ 5 hours) and functional limitation no longer held after this adjustment (OR=1.10; 95%CI=0.80-1.50). In older adults, long sleep duration is a marker of functional limitations independent of comorbidity. Copyright © 2010 Elsevier España, S.L. All rights reserved.

The effect of acupuncture duration on analgesia and peripheral sensory thresholds

Directory of Open Access Journals (Sweden)

Schulteis Gery

2008-05-01

Full Text Available Abstract Background Acupuncture provides a means of peripheral stimulation for pain relief. However, the detailed neuronal mechanisms by which acupuncture relieves pain are still poorly understood and information regarding optimal treatment settings is still inadequate. Previous studies with a short burst of unilateral electroacupuncture (EA in the Tendinomuscular Meridians (TMM treatment model for pain demonstrated a transient dermatomally correlated bilateral analgesic effect with corresponding peripheral modality-specific sensory threshold alterations. However, the impact of EA duration on the analgesic effect in this particular treatment model is unknown. To obtain mechanistically and clinically important information regarding EA analgesia, this current prospective cross-over study assesses the effects of EA duration on analgesia and thermal sensory thresholds in the TMM treatment model. Methods Baseline peripheral sensory thresholds were measured at pre-marked testing sites along the medial aspects (liver and spleen meridians of bilateral lower extremities. A 5-second hot pain stimulation was delivered to the testing sites and the corresponding pain Visual Analog Scale (VAS scores were recorded. Three different EA (5Hz stimulation durations (5, 15 and 30 minutes were randomly tested at least one week apart. At the last 10 seconds of each EA session, 5 seconds of subject specific HP stimulation was delivered to the testing sites. The corresponding pain and EA VAS scores of de qi sensation (tingling during and after the EA were recorded. The measurements were repeated immediately, 30 and 60 minutes after the EA stimulation. A four-factor repeat measures ANOVA was used to assess the effect of stimulation duration, time, location (thigh vs. calf and side (ipsilateral vs. contralateral of EA on sensory thresholds and HP VAS scores. Results A significant (P Conclusion Longer durations of EA stimulation provide a more sustainable analgesic benefit

Born reflection kernel analysis and wave-equation reflection traveltime inversion in elastic media

KAUST Repository

Wang, Tengfei

2017-08-17

Elastic reflection waveform inversion (ERWI) utilize the reflections to update the low and intermediate wavenumbers in the deeper part of model. However, ERWI suffers from the cycle-skipping problem due to the objective function of waveform residual. Since traveltime information relates to the background model more linearly, we use the traveltime residuals as objective function to update background velocity model using wave equation reflected traveltime inversion (WERTI). The reflection kernel analysis shows that mode decomposition can suppress the artifacts in gradient calculation. We design a two-step inversion strategy, in which PP reflections are firstly used to invert P wave velocity (Vp), followed by S wave velocity (Vs) inversion with PS reflections. P/S separation of multi-component seismograms and spatial wave mode decomposition can reduce the nonlinearity of inversion effectively by selecting suitable P or S wave subsets for hierarchical inversion. Numerical example of Sigsbee2A model validates the effectiveness of the algorithms and strategies for elastic WERTI (E-WERTI).

Short-term memory for auditory and visual durations: evidence for selective interference effects.

Science.gov (United States)

Rattat, Anne-Claire; Picard, Delphine

2012-01-01

The present study sought to determine the format in which visual, auditory and auditory-visual durations ranging from 400 to 600 ms are encoded and maintained in short-term memory, using suppression conditions. Participants compared two stimulus durations separated by an interval of 8 s. During this time, they performed either an articulatory suppression task, a visuospatial tracking task or no specific task at all (control condition). The results showed that the articulatory suppression task decreased recognition performance for auditory durations but not for visual or bimodal ones, whereas the visuospatial task decreased recognition performance for visual durations but not for auditory or bimodal ones. These findings support the modality-specific account of short-term memory for durations.

Principles of neutron reflection

International Nuclear Information System (INIS)

Felcher, G.P.

1988-08-01

Neutron reflection is perhaps the most developed branch of slow neutrons optics, which in itself is a direct consequence of the undulatory nature of the neutron. After reviewing the basic types of interactions (nuclear and magnetic) between neutrons and matter, the formalism is introduced to calculate the reflectivity from a sample composed of stacked flat layers and, inversely, to calculate the stacking from reflectivity measurements. Finally, a brief survey of the applications of neutron reflection is given, both in technology and in fundamental research. 32 refs., 6 figs

Storage array reflection considerations

International Nuclear Information System (INIS)

Haire, M.J.; Jordan, W.C.; Taylor, R.G.

1997-01-01

The assumptions used for reflection conditions of single containers are fairly well established and consistently applied throughout the industry in nuclear criticality safety evaluations. Containers are usually considered to be either fully water-reflected (i.e. surrounded by 6 to 12 in. of water) for safety calculations or reflected by 1 in. of water for nominal (structural material and air) conditions. Tables and figures are usually available for performing comparative evaluations of containers under various loading conditions. Reflection considerations used for evaluating the safety of storage arrays of fissile material are not as well established

Clinical significance of mobile health assessed sleep duration and variability in bipolar disorder.

Science.gov (United States)

Kaufmann, Christopher N; Gershon, Anda; Eyler, Lisa T; Depp, Colin A

2016-10-01

Sleep disturbances are prevalent, persistent, and impairing features of bipolar disorder. However, the near-term and cumulative impact of the severity and variability of sleep disturbances on symptoms and functioning remains unclear. We examined self-reported daily sleep duration and variability in relation to mood symptoms, medication adherence, cognitive functioning, and concurrent daily affect. Forty-one outpatients diagnosed with bipolar disorder were asked to provide daily reports of sleep duration and affect collected via ecological momentary assessment with smartphones over eleven weeks. Measures of depressive and manic symptoms, medication adherence, and cognitive function were collected at baseline and concurrent assessment of affect were collected daily. Analyses examined whether sleep duration or variability were associated with baseline measures and changes in same-day or next-day affect. Greater sleep duration variability (but not average sleep duration) was associated with greater depressive and manic symptom severity, and lower medication adherence at baseline, and with lower and more variable ratings of positive affect and higher ratings of negative affect. Sleep durations shorter than 7-8 h were associated with lower same-day ratings of positive and higher same-day ratings of negative affect, however this did not extend to next-day affect. Greater cumulative day-to-day sleep duration variability, but not average sleep duration, was related to more severe mood symptoms, lower self-reported medication adherence and higher levels of negative affect. Bouts of short- or long-duration sleep had transient impact on affect. Day-to-day sleep variability may be important to incorporate into clinical assessment of sleep disturbances in bipolar disorder. Copyright © 2016 Elsevier Ltd. All rights reserved.

Duration of liquid water habitats on early Mars

International Nuclear Information System (INIS)

Mckay, C.P.; Davis, W.L.

1991-01-01

The duration of ice-covered lakes after the initial freezing of the early Mars is presently estimated via a climate model whose critical parameter is the existence of peak seasonal temperatures above freezing, and in which the variability of insolation is included. Under conditions in which meltwater was supplied by an ice source, it is found that water habitats could have been maintained under relatively thin ice sheets for as many as 700 million years after the onset of below-freezing global temperatures. The duration of such habitats on the early Mars therefore exceeds the upper limit of the time envisioned for the emergence of aquatic life on earth. 45 refs

On nuclear reaction duration at the range of overlapping resonances

International Nuclear Information System (INIS)

Olkhovsky, V.S.

1981-01-01

Nuclear reaction duration above the threshold of overlapping resonances is investigated and its importance to obtain a new information on a collision mechanism is evidenced. It is shown also that the duration of resonant nuclear reactions is asymptotically decreasing according to the law[E 2 n(E)] -1 when the energy E and the number of open channels n(E) are increasing [ru

Concurrent schedules of wheel-running reinforcement: choice between different durations of opportunity to run in rats.

Science.gov (United States)

Belke, Terry W

2006-02-01

How do animals choose between opportunities to run of different durations? Are longer durations preferred over shorter durations because they permit a greater number of revolutions? Are shorter durations preferred because they engender higher rates of running? Will longer durations be chosen because running is less constrained? The present study reports on three experiments that attempted to address these questions. In the first experiment, five male Wistar rats chose between 10-sec and 50-sec opportunities to run on modified concurrent variable-interval (VI) schedules. Across conditions, the durations associated with the alternatives were reversed. Response, time, and reinforcer proportions did not vary from indifference. In a second experiment, eight female Long-Evans rats chose between opportunities to run of equal (30 sec) and unequal durations (10 sec and 50 sec) on concurrent variable-ratio (VR) schedules. As in Experiment 1, between presentations of equal duration conditions, 10-sec and 50-sec durations were reversed. Results showed that response, time, and reinforcer proportions on an alternative did not vary with reinforcer duration. In a third experiment, using concurrent VR schedules, durations were systematically varied to decrease the shorter duration toward 0 sec. As the shorter duration decreased, response, time, and reinforcer proportions shifted toward the longer duration. In summary, differences in durations of opportunities to run did not affect choice behavior in a manner consistent with the assumption that a longer reinforcer is a larger reinforcer.

Pump pulse duration dependence of coherent phonon amplitudes in antimony

Energy Technology Data Exchange (ETDEWEB)

Misochko, O. V., E-mail: misochko@issp.ac.ru [Russian Academy of Sciences, Institute of Solid State Physics (Russian Federation)

2016-08-15

Coherent optical phonons of A{sub 1k} and E{sub k} symmetry in antimony have been studied using the femtosecond pump–probe technique. By varying the pump-pulse duration and keeping the probe duration constant, it was shown that the amplitude of coherent phonons of both symmetries exponentially decreases with increasing pulse width. It was found that the amplitude decay rate for the fully symmetric phonons with larger frequency is greater than that of the doubly degenerate phonons, whereas the frequency and lifetime for coherent phonons of both symmetries do not depend on the pump-pulse duration. Based on this data, the possibility of separation between dynamic and kinematic contributions to the generation mechanism of coherent phonons is discussed.

Evaluation of the Planned Outage Durations in EU-APR

Energy Technology Data Exchange (ETDEWEB)

Jung, Byung Joon; Lee, Keun Sung [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

EU-APR has been designed to comply with European Utility Requirements (EUR) and nuclear design requirements of the European countries. And it is modified and improved from its original design of APR1400. The whole duration varies depending on items for additional process. Refueling and regular maintenance outage is comprised of basic processes and Main turbine-generator outage includes dismantling inspection of main generator and high pressure turbine as a critical path in addition to basic processes. In-Service Inspection Outage includes Automatic ultrasonic inspection on the upper side/lower side of a nuclear reactor as a critical path in addition to basic processes. The planned outage durations of EU-APR are optimized according to the above results. And they are complied with EUR Requirement (EUR 2.2.7.2.2 B), respectively. In addition, outage duration can be reduced with improved operating technology and more maintenance friendly environment including betterment of filling, drain and ventilation.

Estimating pediatric general anesthesia exposure: Quantifying duration and risk.

Science.gov (United States)

Bartels, Devan Darby; McCann, Mary Ellen; Davidson, Andrew J; Polaner, David M; Whitlock, Elizabeth L; Bateman, Brian T

2018-05-02

Understanding the duration of pediatric general anesthesia exposure in contemporary practice is important for identifying groups at risk for long general anesthesia exposures and designing trials examining associations between general anesthesia exposure and neurodevelopmental outcomes. We performed a retrospective cohort analysis to estimate pediatric general anesthesia exposure duration during 2010-2015 using the National Anesthesia Clinical Outcomes Registry. A total of 1 548 021 pediatric general anesthetics were included. Median general anesthesia duration was 57 minutes (IQR: 28-86) with 90th percentile 145 minutes. Children aged 3 hours. High ASA physical status and care at a university hospital were associated with longer exposure times. While the vast majority (94%) of children undergoing general anesthesia are exposed for risk for longer exposures. These findings may help guide the design of future trials aimed at understanding neurodevelopmental impact of prolonged exposure in these high-risk groups. © 2018 John Wiley & Sons Ltd.

Fixation distance and fixation duration to vertical road signs.

Science.gov (United States)

Costa, Marco; Simone, Andrea; Vignali, Valeria; Lantieri, Claudio; Palena, Nicola

2018-05-01

The distance of first-fixation to vertical road signs was assessed in 22 participants while driving a route of 8.34 km. Fixations to road signs were recorded by a mobile eye-movement-tracking device synchronized to GPS and kinematic data. The route included 75 road signs. First-fixation distance and fixation duration distributions were positively skewed. Median distance of first-fixation was 51 m. Median fixation duration was 137 ms with a modal value of 66 ms. First-fixation distance was linearly related to speed and fixation duration. Road signs were gazed at a much closer distance than their visibility distance. In a second study a staircase procedure was used to test the presentation-time threshold that lead to a 75% accuracy in road sign identification. The threshold was 35 ms, showing that short fixations to a road signs could lead to a correct identification. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of the Planned Outage Durations in EU-APR

International Nuclear Information System (INIS)

Jung, Byung Joon; Lee, Keun Sung

2016-01-01

EU-APR has been designed to comply with European Utility Requirements (EUR) and nuclear design requirements of the European countries. And it is modified and improved from its original design of APR1400. The whole duration varies depending on items for additional process. Refueling and regular maintenance outage is comprised of basic processes and Main turbine-generator outage includes dismantling inspection of main generator and high pressure turbine as a critical path in addition to basic processes. In-Service Inspection Outage includes Automatic ultrasonic inspection on the upper side/lower side of a nuclear reactor as a critical path in addition to basic processes. The planned outage durations of EU-APR are optimized according to the above results. And they are complied with EUR Requirement (EUR 2.2.7.2.2 B), respectively. In addition, outage duration can be reduced with improved operating technology and more maintenance friendly environment including betterment of filling, drain and ventilation

Compound muscle action potential duration in critical illness neuromyopathy.

Science.gov (United States)

Kramer, Christopher L; Boon, Andrea J; Harper, C Michel; Goodman, Brent P

2018-03-01

We sought to determine the specificity of compound muscle action potential (CMAP) durations and amplitudes in a large critical illness neuromyopathy (CINM) cohort relative to controls with other neuromuscular conditions. Fifty-eight patients with CINM who had been seen over a 17-year period were retrospectively studied. Electrodiagnostic findings of the CINM cohort were compared with patients with axonal peripheral neuropathy and myopathy due to other causes. Mean CMAP durations were prolonged, and mean CMAP amplitudes were severely reduced both proximally and distally in all nerves studied in the CINM cohort relative to the control groups. The specificity of prolonged CMAP durations for CINM approached 100% if they were encountered in more than 1 nerve. Prolonged, low-amplitude CMAPs occur more frequently and with greater severity in CINM patients than in neuromuscular controls with myopathy and axonal neuropathy and are highly specific for the diagnosis of CINM. Muscle Nerve 57: 395-400, 2018. © 2017 Wiley Periodicals, Inc.

Sleep duration of underserved minority children in a cross-sectional study

Science.gov (United States)

Short sleep duration has been shown to associate with increased risk of obesity. Childhood obesity is more prevalent among underserved minority children. The study measured the sleep duration of underserved minority children living in a large US urban environment using accelerometry and its relation...

Thoughts on Reflection (Editorial

Directory of Open Access Journals (Sweden)

Denise Koufogiannakis

2010-06-01

Full Text Available There has been some acknowledgement in the published literature that reflection is a crucial element of the evidence based library and information practice (EBLIP model we have adopted (Booth 2004, 2006; Grant 2007; Helliwell 2007. As we work through a problem and try to incorporate the best available evidence into our decision making, reflection is required at several stages, including the very identification of the problem through to our assessment of the process itself and what we have learned in order to inform future practice. However, reflection and reflective writing have not fully been integrated into the process we espouse, and very little has been done to look more closely at this element of the model and how it can be integrated into professional learning.In a recently published research article, Sen (2010 confirms the relationship between reflection and several aspects of professional practice. These include critical review and decision making, two aspects that are tied closely to the evidence based process. Sen notes: Students were more likely to show evidence of learning, self‐development, the ability to review issues crucially, awareness of their own mental functions, ability to make decision [sic] and being empowered when they had mastered the art of reflective practice and the more deeply analytical reflective writing. (p.84 EBLIP (the journal tries to incorporate elements of reflection within the articles we publish. While we clearly believe in the need for our profession to do quality research and publish that research so that it can be accessible to practitioners, we also know that research cannot be looked at in isolation. Our evidence summaries are one way of reflecting critically on previously published research, and in the same vein, our classics bring older research studies back to the foreground. This work needs to continue to be discussed and looked at for its impact on our profession.More directly, the Using

Different duration of Colchicine for preventing recurrence of Gouty arthritis

Directory of Open Access Journals (Sweden)

H Karimzadeh

2006-05-01

Full Text Available Background: Gout is a Common recurrent clinical syndrome characterized by increased serum uric acid and recurrent attacks of acute arthritis. Colchicine is used for Prophylaxis against recurrence of arthritis, but the duration of its administration has mentioned variable. In this study, optimal duration of prophylactic colchicine for prevention of gouty arthritis was assessed. Methods : In a clinical trial 190 patients with gouty arthritis divided randomly to group 1,2and 3 and received colchicine for 3 to 6, 7 to 9 and 10 to 12 months then colchicine discontinued and the patients followed one year for recurrence of arthritis. Result assessed by survival analysis with Kaplan –Meier method. Results: The probability of recurrence of arthritis (in order of duration of colchicine prophylaxis was 54%, 27.5% and 23%, respectively. The difference between group one and others was statistically significant, but between group 2 and 3 was not statistically significant. Conclusion: The most suitable duration of colchicine prophylaxis that accompanied with lower recurrence rate was 7-9 months, which seems more cost -effective than 10-12 months regimen. Key words: Gout, Colchicine, Arthritis, Recurrence

On a Possible Unified Scaling Law for Volcanic Eruption Durations.

Science.gov (United States)

Cannavò, Flavio; Nunnari, Giuseppe

2016-03-01

Volcanoes constitute dissipative systems with many degrees of freedom. Their eruptions are the result of complex processes that involve interacting chemical-physical systems. At present, due to the complexity of involved phenomena and to the lack of precise measurements, both analytical and numerical models are unable to simultaneously include the main processes involved in eruptions thus making forecasts of volcanic dynamics rather unreliable. On the other hand, accurate forecasts of some eruption parameters, such as the duration, could be a key factor in natural hazard estimation and mitigation. Analyzing a large database with most of all the known volcanic eruptions, we have determined that the duration of eruptions seems to be described by a universal distribution which characterizes eruption duration dynamics. In particular, this paper presents a plausible global power-law distribution of durations of volcanic eruptions that holds worldwide for different volcanic environments. We also introduce a new, simple and realistic pipe model that can follow the same found empirical distribution. Since the proposed model belongs to the family of the self-organized systems it may support the hypothesis that simple mechanisms can lead naturally to the emergent complexity in volcanic behaviour.

The Reflective Foundation

DEFF Research Database (Denmark)

Lunde Jørgensen, Ida

Private foundations and cultural philanthropy by élites is viewed with increasing skepticism in recent years, begging the question of the extent to which foundations reflect on their role vis a vis wider societal norms. Through the prism of the New Carlsberg Foundation, financed by the brewery...... Carlsberg A/S, the paper seeks to elucidate the way in which one culturally significant foundation from Denmark has reflected on - and legitimated - its work and investments at critical moments in the past decades. The paper indicates a foundation with a high degree of reflection on the wider societal...

Dependence of the duration of geomagnetic polarity reversals on site latitude.

Science.gov (United States)

Clement, Bradford M

2004-04-08

An important constraint on the processes governing the geodynamo--the flow in the outer core responsible for generating Earth's magnetic field--is the duration of geomagnetic polarity reversals; that is, how long it takes for Earth's magnetic field to reverse. It is generally accepted that Earth's magnetic field strength drops to low levels during polarity reversals, and the field direction progresses through a 180 degrees change while the field is weak. The time it takes for this process to happen, however, remains uncertain, with estimates ranging from a few thousand up to 28,000 years. Here I present an analysis of the available sediment records of the four most recent polarity reversals. These records yield an average estimate of about 7,000 years for the time it takes for the directional change to occur. The variation about this mean duration is not random, but instead varies with site latitude, with shorter durations observed at low-latitude sites, and longer durations observed at mid- to high-latitude sites. Such variation of duration with site latitude is predicted by simple geometrical reversal models, in which non-dipole fields are allowed to persist while the axial dipole decays through zero and then builds in the opposite direction, and provides a constraint on numerical dynamo models.

Ocular Counter Rolling in Astronauts After Short- and Long-Duration Spaceflight.

Science.gov (United States)

Reschke, Millard F; Wood, Scott J; Clément, Gilles

2018-05-17

Ocular counter-rolling (OCR) is a reflex generated by the activation of the gravity sensors in the inner ear that stabilizes gaze and posture during head tilt. We compared the OCR measures that were obtained in 6 astronauts before, during, and after a spaceflight lasting 4-6 days with the OCR measures obtained from 6 astronauts before and after a spaceflight lasting 4-9 months. OCR in the short-duration fliers was measured using the afterimage method during head tilt at 15°, 30°, and 45°. OCR in the long-duration fliers was measured using video-oculography during whole body tilt at 25°. A control group of 7 subjects was used to compare OCR measures during head tilt and whole body tilt. No OCR occurred during head tilt in microgravity, and the response returned to normal within 2 hours of return from short-duration spaceflight. However, the amplitude of OCR was reduced for several days after return from long-duration spaceflight. This decrease in amplitude was not accompanied by changes in the asymmetry of OCR between right and left head tilt. These results indicate that the adaptation  of otolith-driven reflexes to microgravity is a long-duration process.

Global volcanic earthquake swarm database and preliminary analysis of volcanic earthquake swarm duration

Directory of Open Access Journals (Sweden)

S. R. McNutt

1996-06-01

Full Text Available Global data from 1979 to 1989 pertaining to volcanic earthquake swarms have been compiled into a custom-designed relational database. The database is composed of three sections: 1 a section containing general information on volcanoes, 2 a section containing earthquake swarm data (such as dates of swarm occurrence and durations, and 3 a section containing eruption information. The most abundant and reliable parameter, duration of volcanic earthquake swarms, was chosen for preliminary analysis. The distribution of all swarm durations was found to have a geometric mean of 5.5 days. Precursory swarms were then separated from those not associated with eruptions. The geometric mean precursory swarm duration was 8 days whereas the geometric mean duration of swarms not associated with eruptive activity was 3.5 days. Two groups of precursory swarms are apparent when duration is compared with the eruption repose time. Swarms with durations shorter than 4 months showed no clear relationship with the eruption repose time. However, the second group, lasting longer than 4 months, showed a significant positive correlation with the log10 of the eruption repose period. The two groups suggest that different suites of physical processes are involved in the generation of volcanic earthquake swarms.

Early visual cortex reflects initiation and maintenance of task set

Science.gov (United States)

Elkhetali, Abdurahman S.; Vaden, Ryan J.; Pool, Sean M.

2014-01-01

The human brain is able to process information flexibly, depending on a person's task. The mechanisms underlying this ability to initiate and maintain a task set are not well understood, but they are important for understanding the flexibility of human behavior and developing therapies for disorders involving attention. Here we investigate the differential roles of early visual cortical areas in initiating and maintaining a task set. Using functional Magnetic Resonance Imaging (fMRI), we characterized three different components of task set-related, but trial-independent activity in retinotopically mapped areas of early visual cortex, while human participants performed attention demanding visual or auditory tasks. These trial-independent effects reflected: (1) maintenance of attention over a long duration, (2) orienting to a cue, and (3) initiation of a task set. Participants performed tasks that differed in the modality of stimulus to be attended (auditory or visual) and in whether there was a simultaneous distractor (auditory only, visual only, or simultaneous auditory and visual). We found that patterns of trial-independent activity in early visual areas (V1, V2, V3, hV4) depend on attended modality, but not on stimuli. Further, different early visual areas play distinct roles in the initiation of a task set. In addition, activity associated with maintaining a task set tracks with a participant's behavior. These results show that trial-independent activity in early visual cortex reflects initiation and maintenance of a person's task set. PMID:25485712

Toward tsunami early warning system in Indonesia by using rapid rupture durations estimation

International Nuclear Information System (INIS)

Madlazim

2012-01-01

Indonesia has Indonesian Tsunami Early Warning System (Ina-TEWS) since 2008. The Ina-TEWS has used automatic processing on hypocenter; Mwp, Mw (mB) and Mj. If earthquake occurred in Ocean, depth 7, then Ina-TEWS announce early warning that the earthquake can generate tsunami. However, the announcement of the Ina-TEWS is still not accuracy. Purposes of this research are to estimate earthquake rupture duration of large Indonesia earthquakes that occurred in Indian Ocean, Java, Timor sea, Banda sea, Arafura sea and Pasific ocean. We analyzed at least 330 vertical seismogram recorded by IRIS-DMC network using a direct procedure for rapid assessment of earthquake tsunami potential using simple measures on P-wave vertical seismograms on the velocity records, and the likelihood that the high-frequency, apparent rupture duration, T dur . T dur can be related to the critical parameters rupture length (L), depth (z), and shear modulus (μ) while T dur may be related to wide (W), slip (D), z or μ. Our analysis shows that the rupture duration has a stronger influence to generate tsunami than Mw and depth. The rupture duration gives more information on tsunami impact, Mo/μ, depth and size than Mw and other currently used discriminants. We show more information which known from the rupture durations. The longer rupture duration, the shallower source of the earthquake. For rupture duration greater than 50 s, the depth less than 50 km, Mw greater than 7, the longer rupture length, because T dur is proportional L and greater Mo/μ. Because Mo/μ is proportional L. So, with rupture duration information can be known information of the four parameters. We also suggest that tsunami potential is not directly related to the faulting type of source and for events that have rupture duration greater than 50 s, the earthquakes generated tsunami. With available real-time seismogram data, rapid calculation, rupture duration discriminant can be completed within 4–5 min after an earthquake

Predicting the duration of the Syrian insurgency

Directory of Open Access Journals (Sweden)

Ulrich Pilster

2014-08-01

Full Text Available While there were several relatively short uprisings in Northern Africa and the Middle East during the Arab Spring, the dispute between the rebels and government forces in Syria has evolved into a full-scale civil war. We try to predict the length of the Syrian insurgency with a three-stage technique. Using out-of-sample techniques, we first assess the predictive capacity of 69 explanatory variables for insurgency duration. After determining the model with the highest predictive power, we categorize Syria according to the variables in this final model. Based on in-sample approaches, we then predict the duration of the Syrian uprising for three different scenarios. The most realistic point prediction is 5.12 years from the insurgency’s start, which suggests an end date between the end of 2016 and early 2017.

Reflection-type hologram for atoms

International Nuclear Information System (INIS)

Shimizu, Fujio; Fujita, Jun-ichi

2002-01-01

A cold metastable neon atomic beam was manipulated with a reflective amplitude hologram that was encoded on a silicon surface. A black-and-white pattern of atoms was reconstructed on a microchannel plate detector. The hologram used the enhanced quantum reflection developed by authors and was made of a two-dimensional array of rectangular low and high reflective cells. The surface of the high reflective cell was composed of regularly spaced roof-shaped ridges, while the low reflective cell was simply a flat surface. The hologram was the first demonstration of reflective atom-optical elements that used universal interaction between a neutral atom and solid surface

Building a Shared Definitional Model of Long Duration Human Spaceflight

Science.gov (United States)

Orr, M.; Whitmire, A.; Sandoval, L.; Leveton, L.; Arias, D.

2011-01-01

In 1956, on the eve of human space travel Strughold first proposed a simple classification of the present and future stages of manned flight that identified key factors, risks and developmental stages for the evolutionary journey ahead. As we look to optimize the potential of the ISS as a gateway to new destinations, we need a current shared working definitional model of long duration human space flight to help guide our path. Initial search of formal and grey literature augmented by liaison with subject matter experts. Search strategy focused on both the use of term long duration mission and long duration spaceflight, and also broader related current and historical definitions and classification models of spaceflight. The related sea and air travel literature was also subsequently explored with a view to identifying analogous models or classification systems. There are multiple different definitions and classification systems for spaceflight including phase and type of mission, craft and payload and related risk management models. However the frequently used concepts of long duration mission and long duration spaceflight are infrequently operationally defined by authors, and no commonly referenced classical or gold standard definition or model of these terms emerged from the search. The categorization (Cat) system for sailing was found to be of potential analogous utility, with its focus on understanding the need for crew and craft autonomy at various levels of potential adversity and inability to gain outside support or return to a safe location, due to factors of time, distance and location.

Rats do not respond differently in the presence of stimuli signaling wheel-running reinforcers of different durations.

Science.gov (United States)

Belke, Terry W

2007-05-01

Rats were exposed to a fixed interval 30 s schedule that produced opportunities to run of equal or unequal durations to assess the effect of differences in duration on responding. Each duration was signaled by a different stimulus. Wheel-running reinforcer duration pairs were 30 s 30 s, 50 s 10 s, and 55 s 5 s. An analysis of median postreinforcement pause duration and mean local lever-pressing rates broken down by previous reinforcer duration and duration of signaled upcoming reinforcer showed that postreinforcement pause duration was affected by the duration of the previous reinforcer but not by the stimulus signaling the duration of the upcoming reinforcer. Local lever-pressing rates were not affected by either previous or upcoming reinforcer duration. In general, the results are consistent with indifference between these durations obtained using a concurrent choice procedure.

Speaker-Sex Discrimination for Voiced and Whispered Vowels at Short Durations.

Science.gov (United States)

Smith, David R R

2016-01-01

Whispered vowels, produced with no vocal fold vibration, lack the periodic temporal fine structure which in voiced vowels underlies the perceptual attribute of pitch (a salient auditory cue to speaker sex). Voiced vowels possess no temporal fine structure at very short durations (below two glottal cycles). The prediction was that speaker-sex discrimination performance for whispered and voiced vowels would be similar for very short durations but, as stimulus duration increases, voiced vowel performance would improve relative to whispered vowel performance as pitch information becomes available. This pattern of results was shown for women's but not for men's voices. A whispered vowel needs to have a duration three times longer than a voiced vowel before listeners can reliably tell whether it's spoken by a man or woman (∼30 ms vs. ∼10 ms). Listeners were half as sensitive to information about speaker-sex when it is carried by whispered compared with voiced vowels.

Reflective journal writing: how it promotes reflective thinking in clinical nursing education: a students' perspective.

Science.gov (United States)

Kok, J; Chabeli, M M

2002-08-01

According to the outcomes-based education and training system of education (OBET) in the country and the South African Nursing Council, education should focus on "creating" reflective learners and practitioners. This article seeks to determine the effectiveness of reflective journal writing in promoting the reflective thinking of learners in clinical nursing education and to validate the guidelines described in a bigger study on how to facilitate reflective thinking using reflective journal writing. A qualitative, contextual, explorative, descriptive research design was used to determine the learners' perceptions on whether reflective journal writing did promote their higher-level thinking skills during the six-month placement in a psychiatric clinical practice using the reflective diaries. From a population of seventeen fourth-year students, six volunteered to participate in a focus group interview. The data was analysed by means of the descriptive method of open coding of Tesch (in Creswell, 1994:154-156). Positive and negative results from the perceptions of the participants and a literature review served as a basis for deducing and describing guidelines for the effective use of reflective journal writing in promoting reflective thinking in clinical nursing education. The positive perception was the development of problem-solving skills attained through reflection by using analytical critical thinking, synthesis and the evaluation of situations. Self-evaluation leading to intellectual growth and self-awareness indicated a positive perception. Negative perceptions were that reflective journal writing is time consuming, content based with a lack of clear expectations from the teacher, and distrust of students about the information written. Guba's model of ensuring trustworthiness in qualitative research as described in Krefting (1991:215-222) was employed. It is concluded that reflective journal writing in clinical nursing education does promote reflective

Storage array reflection considerations

International Nuclear Information System (INIS)

Haire, M.J.; Jordan, W.C.; Taylor, R.G.

1997-01-01

The assumptions used for reflection conditions of single containers are fairly well established and consistently applied throughout the industry in nuclear criticality safety evaluations. Containers are usually considered to be either fully water reflected (i.e., surrounded by 6 to 12 in. of water) for safety calculations or reflected by 1 in. of water for nominal (structural material and air) conditions. Tables and figures are usually available for performing comparative evaluations of containers under various loading conditions. Reflection considerations used for evaluating the safety of storage arrays of fissile material are not as well established. When evaluating arrays, it has become more common for analysts to use calculations to demonstrate the safety of the array configuration. In performing these calculations, the analyst has considerable freedom concerning the assumptions made for modeling the reflection of the array. Considerations are given for the physical layout of the array with little or no discussion (or demonstration) of what conditions are bounded by the assumed reflection conditions. For example, an array may be generically evaluated by placing it in a corner of a room in which the opposing walls are far away. Typically, it is believed that complete flooding of the room is incredible, so the array is evaluated for various levels of water mist interspersed among array containers. This paper discusses some assumptions that are made regarding storage array reflection

Work-family conflict, cardiometabolic risk and sleep duration in nursing employees

Science.gov (United States)

Berkman, Lisa F.; Liu, Sze Yan; Hammer, Leslie; Moen, Phyllis; Klein, Laura Cousino; Kelly, Erin; Fay, Martha; Davis, Kelly; Durham, Mary; Karuntzos, Georgia; Buxton, Orfeu M.

2015-01-01

The study investigates the associations of work-family conflict and other work and family conditions with objectively-measured outcomes cardiometabolic risk and sleep duration in a study of employees in nursing homes. Multilevel analyses are used to assess cross-sectional associations between employee and job characteristics and health in analyses of 1,524 employees in 30 extended care facilities in a single company. We examine work and family conditions in relation to two major study health outcomes: 1) a validated, Framingham cardiometabolic risk score based on measured blood pressure, cholesterol, glycosylated hemoglobin (HbA1c), body mass index (BMI), and self-reported tobacco consumption, and 2) wrist actigraphy-based measures of sleep duration. In fully-adjusted multi-level models, Work-To-Family conflict, but not Family-to-Work conflict was positively associated with cardiometabolic risk. Having a lower-level occupation (nursing assistants vs. nurses) was also associated with increased cardiometabolic risk, while being married and having younger children at home was protective. A significant age by Work-To-Family conflict interaction revealed that higher Work-To-Family conflict was more strongly associated with increased cardiometabolic risk in younger employees. With regard to sleep duration, high Family-To-Work Conflict was significantly associated with shorter sleep duration. In addition, working long hours and having younger children at home were both independently associated with shorter sleep duration. High Work-To-Family Conflict was associated with longer sleep duration. These results indicate that different dimensions of work-family conflict (i.e., Work-To-Family Conflict and Family-To-Work Conflict) may both pose threats to cardiometabolic risk and sleep duration for employees. This study contributes to the research on work- family conflict suggesting that Work-To-Family and Family-To-Work conflict are associated with specific outcomes. Translating

Regional estimation of rainfall intensity-duration-frequency curves using generalized least squares regression of partial duration series statistics

DEFF Research Database (Denmark)

Madsen, H.; Mikkelsen, Peter Steen; Rosbjerg, Dan

2002-01-01

A general framework for regional analysis and modeling of extreme rainfall characteristics is presented. The model is based on the partial duration series (PDS) method that includes in the analysis all events above a threshold level. In the PDS model the average annual number of exceedances...

Unveiling the Progenitors of Short-duration Gamma-ray Bursts

Science.gov (United States)

Fong, Wen-Fai

2016-03-01

Gamma-ray bursts (GRBs) are relativistic explosions which originate at cosmological distances, and are among the most luminous transients in the universe. Following the prompt gamma-ray emission, a fading synchrotron ``afterglow'' is detectable at lower energies. While long-duration GRBs (duration >2 sec) are linked to the deaths of massive stars, the progenitors of short-duration GRBs (duration black hole. Such merging systems are also important to understand because they are premier candidates for gravitational wave detections with current facilities and are likely sites of heavy element nucleosynthesis. The launch of NASA's Swift satellite in 2004, with its rapid multi-wavelength monitoring and localization capabilities, led to the first discoveries of short GRB afterglows and therefore robust associations to host galaxies. At a detection rate of roughly 10 events per year, the growing number of well-localized short GRBs has enabled comprehensive population studies of their afterglows and environments for the first time. In this talk, I describe my multi-wavelength observational campaign to address testable predictions for the progenitors of short GRBs. My work comprises several lines of independent evidence to demonstrate that short GRBs originate from the mergers of two compact objects, and also provides the first constraints on the explosion properties for a large sample of events. With the direct detection of gravitational waves from compact object mergers on the horizon, these studies provide necessary inputs to inform the next decade of joint electromagnetic-gravitational wave search strategies.

Reflectance Modeling

Science.gov (United States)

Smith, J. A.; Cooper, K.; Randolph, M.

1984-01-01

A classical description of the one dimensional radiative transfer treatment of vegetation canopies was completed and the results were tested against measured prairie (blue grama) and agricultural canopies (soybean). Phase functions are calculated in terms of directly measurable biophysical characteristics of the canopy medium. While the phase functions tend to exhibit backscattering anisotropy, their exact behavior is somewhat more complex and wavelength dependent. A Monte Carlo model was developed that treats soil surfaces with large periodic variations in three dimensions. A photon-ray tracing technology is used. Currently, the rough soil surface is described by analytic functions and appropriate geometric calculations performed. A bidirectional reflectance distribution function is calculated and, hence, available for other atmospheric or canopy reflectance models as a lower boundary condition. This technique is used together with an adding model to calculate several cases where Lambertian leaves possessing anisotropic leaf angle distributions yield non-Lambertian reflectance; similar behavior is exhibited for simulated soil surfaces.

Sleep Duration and Patterns in Chinese Older Adults: a Comprehensive Meta-analysis.

Science.gov (United States)

Lu, Li; Wang, Shi-Bin; Rao, Wen-Wang; Ungvari, Gabor S; Ng, Chee H; Chiu, Helen F K; Zhang, Juan; Kou, Changgui; Jia, Fu-Jun; Xiang, Yu-Tao

2017-01-01

This meta-analysis examined the mean sleep duration and patterns in Chinese older adult population. A literature search was systematically conducted covering major English (PubMed, Embase and PsycINFO) and Chinese (Chinese National Knowledge Infrastructure (CNKI), WanFang and SinoMed) databases. Data in studies with the mean and standard deviation of sleep duration and/or the proportion of short and long sleep durations in Chinese older adults were extracted and pooled using random-effects models. Subgroup analyses were conducted according to gender, region, area, survey time and sample size. A total of 36 studies with 150,616 subjects were included for analyses. The pooled mean sleep duration of 21 studies with available data was 6.82 hours/day (95% CI: 6.59-7.05 hours/day). The estimated proportions of sleep duration 8 hours/day) and 17.6% (95% CI: 12.4%-22.9%) (>9 hours/day). Given the adverse effects of unhealthy sleep patterns, health professionals should pay more attention to sleep patterns in this population in China.

20 CFR 663.420 - Can the duration and amount of ITA's be limited?

Science.gov (United States)

2010-04-01

... Training Accounts § 663.420 Can the duration and amount of ITA's be limited? (a) Yes, the State or Local Board may impose limits on ITA's, such as limitations on the dollar amount and/or duration. (b) Limits... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Can the duration and amount of ITA's be...

Changes in Sleep Duration During Transition to Statutory Retirement: A Longitudinal Cohort Study.

Science.gov (United States)

Myllyntausta, Saana; Salo, Paula; Kronholm, Erkki; Aalto, Ville; Kivimäki, Mika; Vahtera, Jussi; Stenholm, Sari

2017-07-01

This study examined whether sleep duration changes during the transition from full-time work to statutory retirement and, if this were the case, which preretirement factors, including sociodemographic, work, lifestyle, and health factors, predict these changes. Data from repeated surveys of the Finnish Public Sector study, linked to records of retirement, were used. The study population consisted of 5785 participants who retired on a statutory basis in 2000-2011 and who had responded to surveys on sleep duration at least once immediately before and after their retirement (mean number of repeat study waves 3.6). Linear regression analyses with generalized estimating equations were used to examine changes in sleep duration around retirement. Before retirement there was a slight decrease in sleep duration. During the 4-year retirement transition, sleep duration increased from 7 hours 0 minutes (95% confidence interval [CI] 6 hours 54 minutes to 7 hours 6 minutes) to 7 hours and 22 minutes (95% CI 7 hours 16 minutes to 7 hours 27 minutes); thus, mean increase being 22 minutes. Increase in sleep duration was greatest in those who were short sleepers, heavy drinkers, or had sleep difficulties. After the retirement transition, sleep duration remained at approximately the same level, as no significant changes were observed. This longitudinal study suggests that transition from full-time work to statutory retirement is associated with an increase in sleep duration. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

The Duration of Energy Deposition on Unresolved Flaring Loops in the Solar Corona

Science.gov (United States)

Reep, Jeffrey W.; Polito, Vanessa; Warren, Harry P.; Crump, Nicholas A.

2018-04-01

Solar flares form and release energy across a large number of magnetic loops. The global parameters of flares, such as the total energy released, duration, physical size, etc., are routinely measured, and the hydrodynamics of a coronal loop subjected to intense heating have been extensively studied. It is not clear, however, how many loops comprise a flare, nor how the total energy is partitioned between them. In this work, we employ a hydrodynamic model to better understand the energy partition by synthesizing Si IV and Fe XXI line emission and comparing to observations of these lines with the Interface Region Imaging Spectrograph (IRIS). We find that the observed temporal evolution of the Doppler shifts holds important information on the heating duration. To demonstrate this, we first examine a single loop model, and find that the properties of chromospheric evaporation seen in Fe XXI can be reproduced by loops heated for long durations, while persistent redshifts seen in Si IV cannot be reproduced by any single loop model. We then examine a multithreaded model, assuming both a fixed heating duration on all loops and a distribution of heating durations. For a fixed heating duration, we find that durations of 100–200 s do a fair job of reproducing both the red- and blueshifts, while a distribution of durations, with a median of about 50–100 s, does a better job. Finally, we compare our simulations directly to observations of an M-class flare seen by IRIS, and find good agreement between the modeled and observed values given these constraints.

34 CFR 600.10 - Date, extent, duration, and consequence of eligibility.

Science.gov (United States)

2010-07-01

... 34 Education 3 2010-07-01 2010-07-01 false Date, extent, duration, and consequence of eligibility... EDUCATION ACT OF 1965, AS AMENDED General § 600.10 Date, extent, duration, and consequence of eligibility... statutory and regulatory requirements governing its eligibility. (e) Consequence of eligibility. (1) If, as...

The effects of static stretch duration on the flexibility of hamstring ...

African Journals Online (AJOL)

The effects of static stretch duration on the flexibility of hamstring muscles. NA Odunaiya, TK Hamzat, OF Ajayi. Abstract. The effects of duration of a static stretching protocol (Intervention) on hamstrings tightness were evaluated. Sixty purposively sampled subjects with unilateral hamstring tightness that had no history of low ...

Sleep duration is significantly associated with carotid artery atherosclerosis incidence in a Japanese population.

Science.gov (United States)

Abe, Tsueko; Aoki, Toshinari; Yata, Syogo; Okada, Masahiko

2011-08-01

Previous studies have indicated that sleep duration is associated with total mortality in a U-shaped fashion. The purpose of the current study was to examine the relationship between self-reported sleep duration and carotid artery atherosclerosis in a Japanese population. In 2009-2010, a total of 2498 participants (1195 men, 1303 women; age range, 23-92 years) were recruited from members of a Japanese community receiving annual health check-up at a local health center who agreed to participate in the study. Exclusion criteria were as follows: age <40 or ≥85 years; and more than one missing value from either laboratory data or questionnaire responses. A total of 2214 participants were entered into the study. Carotid artery arteriosclerosis was evaluated ultrasonographically and quantified as intima-medial thickness (IMT). The presence of carotid artery atherosclerosis was defined as IMT≥1.2 mm. Sleep durations were compared with IMT measurements after controlling for confounding factors such as age, sex, lipid profile, fasting plasma glucose, hemoglobin A1c, blood pressure, alcohol intake, and smoking habit. Sleep duration ≥7 h correlated significantly with the incidence of IMT≥1.2 m when compared with a sleep duration of 6 h (multivariate-adjusted odds ratio, 1.263; 95% confidence interval, 1.031-1.546, P=0.024). Shorter sleep duration ≤5 h did not correlate significantly with the risk compared with a sleep duration of 6 h. Long sleep duration (≥7 h) correlated significantly with the incidence of carotid artery atherosclerosis compared with a sleep duration of 6 h, but shorter sleep duration did not. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Short Operative Duration and Surgical Site Infection Risk in Hip and Knee Arthroplasty Procedures.

Science.gov (United States)

Dicks, Kristen V; Baker, Arthur W; Durkin, Michael J; Anderson, Deverick J; Moehring, Rebekah W; Chen, Luke F; Sexton, Daniel J; Weber, David J; Lewis, Sarah S

2015-12-01

To determine the association (1) between shorter operative duration and surgical site infection (SSI) and (2) between surgeon median operative duration and SSI risk among first-time hip and knee arthroplasties. Retrospective cohort study A total of 43 community hospitals located in the southeastern United States. Adults who developed SSIs according to National Healthcare Safety Network criteria within 365 days of first-time knee or hip arthroplasties performed between January 1, 2008 and December 31, 2012. Log-binomial regression models estimated the association (1) between operative duration and SSI outcome and (2) between surgeon median operative duration and SSI outcome. Hip and knee arthroplasties were evaluated in separate models. Each model was adjusted for American Society of Anesthesiology score and patient age. A total of 25,531 hip arthroplasties and 42,187 knee arthroplasties were included in the study. The risk of SSI in knee arthroplasties with an operative duration shorter than the 25th percentile was 0.40 times the risk of SSI in knee arthroplasties with an operative duration between the 25th and 75th percentile (risk ratio [RR], 0.40; 95% confidence interval [CI], 0.38-0.56; Poperative duration did not demonstrate significant association with SSI for hip arthroplasties (RR, 1.04; 95% CI, 0.79-1.37; P=.36). Knee arthroplasty surgeons with shorter median operative durations had a lower risk of SSI than surgeons with typical median operative durations (RR, 0.52; 95% CI, 0.43-0.64; Poperative durations were not associated with a higher SSI risk for knee or hip arthroplasty procedures in our analysis.

Antenatal breastfeeding education for increasing breastfeeding duration

Science.gov (United States)

Lumbiganon, Pisake; Martis, Ruth; Laopaiboon, Malinee; Festin, Mario R; Ho, Jacqueline J; Hakimi, Mohammad

2014-01-01

Background Breastfeeding (BF) is well recognised as the best food for infants. The impact of antenatal BF education on the duration of BF has not been evaluated. Objectives To evaluate the effectiveness of antenatal BF education for increasing BF initiation and duration. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (21 April 2010), CENTRAL (The Cochrane Library 2010, Issue 2), MEDLINE (1966 to April 2010) and SCOPUS (January 1985 to April 2010). We contacted experts and searched reference lists of retrieved articles. We updated the search of the Pregnancy and Childbirth Group’s Trials Register on 28 September 2011 and added the results to the awaiting classification section of the review. Selection criteria All identified published, unpublished and ongoing randomised controlled trials (RCTs) assessing the effect of formal antenatal BF education or comparing two different methods of formal antenatal BF education, on duration of BF. We excluded RCTs that also included intrapartum or postpartum BF education. Data collection and analysis We assessed all potential studies identified as a result of the search strategy. Two review authors extracted data from each included study using the agreed form and assessed risk of bias. We resolved discrepancies through discussion. Main results We included 17 studies with 7131 women in the review and 14 studies involving 6932 women contributed data to the analyses. We did not do any meta-analysis because there was only one study for each comparison. Five studies compared a single method of BF education with routine care. Peer counselling significantly increased BF initiation. Three studies compared one form of BF education versus another. No intervention was significantly more effective than another intervention in increasing initiation or duration of BF. Seven studies compared multiple methods versus a single method of BF education. Combined BF educational interventions were not

[Duration of breast feeding after mandatory early discharge].

Science.gov (United States)

Kierkegaard, O

1993-08-23

A trial arrangement for mandatory early discharge for all normal multiparae was started in 1990 and the duration of breastfeeding was investigated by a questionnaire. 89 mothers who stayed at the hospital were compared to 113 mothers who were discharged within 24 hours after delivery. The latter group was also compared to 122 early discharged mothers who delivered 14-17 months after the trial arrangement had started. The three groups were comparable in all aspects. After four weeks a large proportion of the later discharged mothers were still breastfeeding compared to the other two groups (p < 0.001). This difference disappeared later, hence when comparing the total duration of breastfeeding no differences were found between the three groups.

Sleep duration and age-related changes in brain structure and cognitive performance.

Science.gov (United States)

Lo, June C; Loh, Kep Kee; Zheng, Hui; Sim, Sam K Y; Chee, Michael W L

2014-07-01

To investigate the contribution of sleep duration and quality to age-related changes in brain structure and cognitive performance in relatively healthy older adults. Community-based longitudinal brain and cognitive aging study using a convenience sample. Participants were studied in a research laboratory. Relatively healthy adults aged 55 y and older at study commencement. N/A. Participants underwent magnetic resonance imaging and neuropsychological assessment every 2 y. Subjective assessments of sleep duration and quality and blood samples were obtained. Each hour of reduced sleep duration at baseline augmented the annual expansion rate of the ventricles by 0.59% (P = 0.007) and the annual decline rate in global cognitive performance by 0.67% (P = 0.050) in the subsequent 2 y after controlling for the effects of age, sex, education, and body mass index. In contrast, global sleep quality at baseline did not modulate either brain or cognitive aging. High-sensitivity C-reactive protein, a marker of systemic inflammation, showed no correlation with baseline sleep duration, brain structure, or cognitive performance. In healthy older adults, short sleep duration is associated with greater age-related brain atrophy and cognitive decline. These associations are not associated with elevated inflammatory responses among short sleepers. Lo JC, Loh KK, Zheng H, Sim SK, Chee MW. Sleep duration and age-related changes in brain structure and cognitive performance.

Path durations for use in the stochastic‐method simulation of ground motions

Science.gov (United States)

Boore, David M.; Thompson, Eric M.

2014-01-01

The stochastic method of ground‐motion simulation assumes that the energy in a target spectrum is spread over a duration DT. DT is generally decomposed into the duration due to source effects (DS) and to path effects (DP). For the most commonly used source, seismological theory directly relates DS to the source corner frequency, accounting for the magnitude scaling of DT. In contrast, DP is related to propagation effects that are more difficult to represent by analytic equations based on the physics of the process. We are primarily motivated to revisit DT because the function currently employed by many implementations of the stochastic method for active tectonic regions underpredicts observed durations, leading to an overprediction of ground motions for a given target spectrum. Further, there is some inconsistency in the literature regarding which empirical duration corresponds to DT. Thus, we begin by clarifying the relationship between empirical durations and DT as used in the first author’s implementation of the stochastic method, and then we develop a new DP relationship. The new DP function gives significantly longer durations than in the previous DP function, but the relative contribution of DP to DT still diminishes with increasing magnitude. Thus, this correction is more important for small events or subfaults of larger events modeled with the stochastic finite‐fault method.

Effects of methylprednisolone on the duration of rocuronium-induced neuromuscular block

Science.gov (United States)

Geng, Weilian; Nie, Yuyan; Huang, Shaoqiang

2017-01-01

Abstract Background: We aim to investigate whether intraoperative use of methylprednisolone could affect the duration of rocuronium-induced neuromuscular blockade. Methods: A double blind, randomized, placebo-controlled trial was conducted. A total of 136 patients underwent gynecologic laparoscopic surgery were randomly divided into 3 groups: pregroup, receiving intravenous injection of methylprednisolone (40 mg) 30 minutes before induction of anesthesia; postgroup, receiving intravenous injection of methylprednisolone (40 mg) immediately after induction of anesthesia and intubation; and control group, receiving intravenous injection of normal saline. Patients were intravenously administrated with rocuronium 0.6 mg/kg, and changes in adductor policies evoked twitch responses were measured by ulnar nerve stimulator. Results: We found that all patients achieved maximum blockade effects, and there was no difference in onset time among the 2 groups. For time required to achieve train-of-four ratio (TOFR) 90%, pregroup (64.50 ± 10.52 minutes) and postgroup (65.29 ± 11.64 minutes) were significantly shorter than that of the control group (71.04 ± 10.55 minutes, P = .027), whereas clinical duration and total duration were significantly shorter in the 2 groups received methylprednisolone than the control group. However, there was no significant difference between the 2 treatment groups either in clinical duration and total duration of muscle relaxants, or time required to achieve TOFR 90%. No significant difference was found in recovery index among the 3 groups. Conclusion: Our findings suggest that a single intravenous injection of methylprednisolone, no matter preoperatively or intraoperatively, could shorten the duration of rocuronium-induced neuromuscular blockade. PMID:28953616

Reflection Revisited: The Class Collage

Science.gov (United States)

Sommers, Jeff

2011-01-01

Through the regular use of what Donald Schon has termed reflection-in-action and reflection-on-action, students can learn to improve their "reflection-in-presentation," in Kathleen Blake Yancey's term. Students are often asked to do this type of reflection-in-presentation as a capstone to first-year or basic writing courses. However, a number of…

Techniques for the estimation of global irradiation from sunshine duration and global irradiation estimation for Italian locations

International Nuclear Information System (INIS)

Jain, P.C.

1984-04-01

Angstrom equation H=H 0 (a+bS/S 0 ) has been fitted using the least-square method to the global irradiation and the sunshine duration data of 31 Italian locations for the duration 1965-1974. Three more linear equations: i) the equation H'=H 0 (a+bS/S 0 ), obtained by incorporating the effect of the multiple reflections between the earth's surface and the atmosphere, ii) the equation H=H 0 (a+bS/S' 0 ), obtained by incorporating the effect of not burning of the sunshine recorder chart when the elevation of the sun is less than 5 deg., and iii) the equation H'=H 0 (a+bS/S' 0 ), obtained by incorporating both the above effects simultaneously, have also each been fitted to the same data. Good correlation with correlation coefficients around 0.9 or more are obtained for most of the locations with all the four equations. Substantial spatial scatter is obtained in the values of the regression parameters. The use of any of the three latter equations does not result in any advantage over that of the simpler Angstrom equation; it neither results in a decrease in the spatial scatter in the values of the regression parameters nor does it yield better correlation. The computed values of the regression parameters in the Angstrom equation yield estimates of the global irradiation that are on the average within +- 4% of the measured values for most of the locations. (author)

Effect of Load Duration on Timber Structures in Denmark

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Stang, Birgitte Friis Dela; Svensson, Staffan

2003-01-01

. The parameters in these models are fitted by the Maximum Likelihood Method using data relevant for Danish structural timber and the statistical uncertainty is quantified. The reliability is evaluated using representative shortand long-term limit states, and the load duration factor kmod is estimated using......Load duration effects are estimated on basis of simulation of realizations of wind, snow and imposed loads in accordance with the load models in the Danish structural codes. Three damage accumulation models are considered, namely Gerhards model, Barret & Foschi's model and Foschi & Yao's model...

Long-term duration of function of ovarian tissue transplants

DEFF Research Database (Denmark)

Andersen, Claus; Silber, Sherman J; Berghold, Stinne Holm

2012-01-01

These three case reports describe the long-term duration of function of ovarian cortical tissue grafts among patients in a university fertility preservation programme in Europe and in a private practice programme in the USA. One woman underwent sterilizing cancer treatment and had frozen ovarian...... or to alleviate its symptoms. These three case reports describe the long-term duration of function of ovarian cortical tissue grafts among patients in a university fertility preservation programme in Europe and in a private practice programme in the USA. One woman underwent sterilizing cancer treatment and had...

Sleep Duration Associated with the Lowest Risk of Depression/Anxiety in Adolescents.

Science.gov (United States)

Ojio, Yasutaka; Nishida, Atsushi; Shimodera, Shinji; Togo, Fumiharu; Sasaki, Tsukasa

2016-08-01

To investigate sleep duration associated with the least depression/anxiety in adolescence. Grades 7-12 Japanese students (n = 18,250, aged 12-18 y) from public junior high/high schools were studied in a cross-sectional design. Due to missing/implausible data, 15,637 out of the 18,250 students were statistically analyzed. Relationship between sleep duration on school nights and depression/anxiety, measured using self-report questionnaires, including the General Health Questionnaire-12 (GHQ-12), were studied by sex and grade, controlling for bedtime regularity. When sleep duration was classified by 1-h intervals, rate of adolescents with a GHQ-12 score ≥ 4 was the lowest in males and females who slept 8.5-9.5 h and 7.5-8.5 h, respectively, (designated "references") in both grades 7-9 and 10-12. The rate was significantly higher than the references in both males and females who slept Sleep duration for the minimum GHQ-12 score was estimated to be 8.8 and 8.5 h in males, and 8.0 and 7.5 h in females, in grades 7-9 and 10-12, respectively, using the General Additive Model. Sleep duration of ≥ 8.5 h on school nights may be associated with the lowest risk of depression/anxiety on average in male adolescents. Although the duration was estimated to be shorter in females (≥ 7.5 h) than males, this should be interpreted carefully. Most adolescents may currently be sleeping less than the optimal duration. A commentary on this article appears in this issue on page 1491. © 2016 Associated Professional Sleep Societies, LLC.

Reflection: A Socratic approach.

Science.gov (United States)

Van Seggelen-Damen, Inge C M; Van Hezewijk, René; Helsdingen, Anne S; Wopereis, Iwan G J H

2017-12-01

Reflection is a fuzzy concept. In this article we reveal the paradoxes involved in studying the nature of reflection. Whereas some scholars emphasize its discursive nature, we go further and underline its resemblance to the self-biased dialogue Socrates had with the slave in Plato's Meno . The individual and internal nature of the reflection process creates difficulty for studying it validly and reliably. We focus on methodological issues and use Hans Linschoten's view of coupled systems to identify, analyze, and interpret empirical research on reflection. We argue that researchers and research participants can take on roles in several possible system couplings. Depending on who controls the manipulation of the stimulus, who controls the measuring instrument, who interprets the measurement and the response, different types of research questions can be answered. We conclude that reflection may be validly studied by combining different couplings of experimenter, manipulation, stimulus, participant, measurement, and response.

Application of the specular and diffuse reflection analysis for in vitro diagnostics of dental erosion: correlation with enamel softening, roughness, and calcium release

Science.gov (United States)

Rakhmatullina, Ekaterina; Bossen, Anke; Höschele, Christoph; Wang, Xiaojie; Beyeler, Barbara; Meier, Christoph; Lussi, Adrian

2011-01-01

We present assembly and application of an optical reflectometer for the analysis of dental erosion. The erosive procedure involved acid-induced softening and initial substance loss phases, which are considered to be difficult for visual diagnosis in a clinic. Change of the specular reflection signal showed the highest sensitivity for the detection of the early softening phase of erosion among tested methods. The exponential decrease of the specular reflection intensity with erosive duration was compared to the increase of enamel roughness. Surface roughness was measured by optical analysis, and the observed tendency was correlated with scanning electron microscopy images of eroded enamel. A high correlation between specular reflection intensity and measurement of enamel softening (r2 ≥ −0.86) as well as calcium release (r2 ≥ −0.86) was found during erosion progression. Measurement of diffuse reflection revealed higher tooth-to-tooth deviation in contrast to the analysis of specular reflection intensity and lower correlation with other applied methods (r2 = 0.42–0.48). The proposed optical method allows simple and fast surface analysis and could be used for further optimization and construction of the first noncontact and cost-effective diagnostic tool for early erosion assessment in vivo. PMID:22029364

Short sleep duration and obesity among Australian children

Directory of Open Access Journals (Sweden)

Gill Tiffany K

2010-10-01

Full Text Available Abstract Background There is limited information on sleep duration and obesity among Australian children. The objective of the study is to cross-sectionally examine the relationship between sleep duration and obesity in Australian children aged 5 to 15 years. Methods Data were collected using the South Australian Monitoring and Surveillance System between January 2004 and December 2008. Each month a representative random sample of South Australians are selected from the Electronic White Pages with interviews conducted using Computer Assisted Telephone Interviewing (CATI. Within each household, the person who was last to have a birthday was selected for interview. Parents reported the number of hours their children slept each day. Obesity was defined according to the International Obesity Task Force (IOTF definition based on BMI calculated from reported body weight and height. Results Overall, parents of 3495 children aged 5-15 years (mean 10.7 years, 50.3% boys were interviewed. The prevalence of obesity was 7.7% (8.9% in boys, 6.6% in girls. In multivariate analysis after adjusting for sociodemographic variables, intake of fruit and vegetables, physical activity and inactivity, the odds ratio (OR for obesity comparing sleeping Conclusion Short sleep duration is associated with increased obesity in children especially among younger age groups and boys.

Predictive Models of Duration of Ground Delay Programs in New York Area Airports

Science.gov (United States)

Kulkarni, Deepak

2011-01-01

Initially planned GDP duration often turns out to be an underestimate or an overestimate of the actual GDP duration. This, in turn, results in avoidable airborne or ground delays in the system. Therefore, better models of actual duration have the potential of reducing delays in the system. The overall objective of this study is to develop such models based on logs of GDPs. In a previous report, we described descriptive models of Ground Delay Programs. These models were defined in terms of initial planned duration and in terms of categorical variables. These descriptive models are good at characterizing the historical errors in planned GDP durations. This paper focuses on developing predictive models of GDP duration. Traffic Management Initiatives (TMI) are logged by Air Traffic Control facilities with The National Traffic Management Log (NTML) which is a single system for automated recoding, coordination, and distribution of relevant information about TMIs throughout the National Airspace System. (Brickman, 2004 Yuditsky, 2007) We use 2008-2009 GDP data from the NTML database for the study reported in this paper. NTML information about a GDP includes the initial specification, possibly one or more revisions, and the cancellation. In the next section, we describe general characteristics of Ground Delay Programs. In the third section, we develop models of actual duration. In the fourth section, we compare predictive performance of these models. The final section is a conclusion.

Verifying duration properties of timed transition systems

DEFF Research Database (Denmark)

Liu, Zhiming; Ravn, Anders P.; Li, Xiaoshan

1998-01-01

This paper proposes a method for formal real-time systems development:Requirements and high level design decisions are time interval properties and are therefore specified in the Duration Calculus (DC), while implementations are described bytimed transition systems (TTS). A link from implementati...

Re-thinking reflection in supervision

DEFF Research Database (Denmark)

Lystbæk, Christian Tang

The paper presents a socio-cultural perspective on supervision in professional education, which challenges the current reflective paradigm and move the debate on reflection in supervision in professional education and learning towards a recognition of context, power dynamics and ideological...... of reflective practice has been formalized by regulatory bodies as a way to develop the professionalism of both individual professional practitioners as students through continuing professional developmental processes. Consequently, reflection is often used as a `tool´ for personal and professional development...... al., 2010). This conceptual paper presents a critical, socio-cultural perspective on the current paradigm or dogma of reflective practice within supervision in professional education and learning. The purpose I to challenge the dogma and critically to analyze and move the debate on reflection...

Demystifying the reflective clinical journal

International Nuclear Information System (INIS)

Milinkovic, Danielle; Field, Nikki

2005-01-01

Student learning on clinical placement is a complex issue and cannot be defined solely by just doing things. Reflection during clinical practice is essential if the student is going to learn from the experience. Therefore it is important for educators to include as part of clinical education programs learning strategies that encourage reflection. The reflective clinical journal is an educational tool that is employed by the School of Medical Radiation Sciences at the University of Sydney to encourage reflection of undergraduate radiation therapy students whilst on clinical placement. This discussion paper explores the key concepts of reflection and the reflective clinical journal. Due to the paucity of information about this issue in radiation therapy the literature reviewed is from across all areas of the health sciences

A survey of relationship between anxiety, depression and duration of infertility

Directory of Open Access Journals (Sweden)

Shariat Mamak

2004-11-01

Full Text Available Abstract Background A cross sectional study was designed to survey the relationship between anxiety/depression and duration/cause of infertility, in Vali-e-Asr Reproductive Health Research Center, Tehran, Iran. Methods After obtaining their consents, 370 female patients with different infertility causes participated in, and data gathered by Beck Depression Inventory(BDI and Cattle questionnaires for surveying anxiety and depression due to the duration of infertility. This was studied in relation to patients' age, educational level, socio-economic status and job (patients and their husbands. Results Age range was 17–45 years and duration and cause of infertility was 1–20 years. This survey showed that 151 women (40.8% had depression and 321 women (86.8% had anxiety. Depression had a significant relation with cause of infertility, duration of infertility, educational level, and job of women. Anxiety had a significant relationship with duration of infertility and educational level, but not with cause of infertility, or job. Findings showed that anxiety and depression were most common after 4–6 years of infertility and especially severe depression could be found in those who had infertility for 7–9 years. Conclusions Adequate attention to these patients psychologically and treating them properly, is of great importance for their mental health and will improve quality of their lives.

Breastfeeding Duration: A Survival Analysis—Data from a Regional Immunization Survey

Directory of Open Access Journals (Sweden)

E. Robert

2014-01-01

Full Text Available Objective. To report the duration of and factors associated with exclusive and any breastfeeding among the French-speaking community of Belgium (Wallonia. Material and Methods. A two-stage cluster sample was drawn from the population of children aged 18–24 months living in the area in 2012. Anamnestic data on breastfeeding and sociodemographic information were collected from 525 mothers. Cox’s proportional hazards model was used to identify factors associated with discontinuing breastfeeding. Results and Discussion. Only 35.1% of the women were satisfied with their duration of any breastfeeding. At 3 months, 54.1% of the infants were breastfed, of which 40.6% exclusively, with these percentages falling to 29.1% and 12.6% at 6 months. Exclusive and any breastfeeding durations were independently positively associated (P3 months. Exclusive BF duration was associated with higher parental income and the prenatal decision to breastfeed. The duration of any breastfeeding was associated with the mothers’ age of ≥30 years and whether they were exclusively breastfeeding at discharge from the maternity unit. Conclusions. Programs promoting and supporting BF should concentrate on training prenatal health-care professionals. Prenatal professional advice may promote adherence to WHO BF guidelines. The benefits of exclusive BF should be emphasized. Pregnant women should be discouraged from introducing supplementary feeding in the maternity ward.

'Combined reflectance stratigraphy' - subdivision of loess successions by diffuse reflectance spectrometry (DRS)

Science.gov (United States)

Szeberényi, Jozsef; Bradak-Hayashi, Balázs; Kiss, Klaudia; Kovács, József; Varga, György; Balázs, Réka; Szalai, Zoltán; Viczián, István

2016-04-01

The different varieties of loess (and intercalated paleosol layers) together constitute one of the most widespread terrestrial sediments, which was deposited, altered, and redeposited in the course of the changing climatic conditions of the Pleistocene. To reveal more information about Pleistocene climate cycles and/or environments the detailed lithostratigraphical subdivision and classification of the loess variations and paleosols are necessary. Beside the numerous method such as various field measurements, semi-quantitative tests and laboratory investigations, diffuse reflectance spectroscopy (DRS) is one of the well applied method on loess/paleosol sequences. Generally, DRS has been used to separate the detrital and pedogenic mineral component of the loess sections by the hematite/goethite ratio. DRS also has been applied as a joint method of various environmental magnetic investigations such as magnetic susceptibility- and isothermal remanent magnetization measurements. In our study the so-called "combined reflectance stratigraphy method" were developed. At First, complex mathematical method was applied to compare the results of the spectral reflectance measurements. One of the most preferred multivariate methods is cluster analysis. Its scope is to group and compare the loess variations and paleosol based on the similarity and common properties of their reflectance curves. In the Second, beside the basic subdivision of the profiles by the different reflectance curves of the layers, the most characteristic wavelength section of the reflectance curve was determined. This sections played the most important role during the classification of the different materials of the section. The reflectance value of individual samples, belonged to the characteristic wavelength were depicted in the function of depth and well correlated with other proxies like grain size distribution and magnetic susceptibility data. The results of the correlation showed the significance of

The association between mental health, chronic disease and sleep duration in Koreans: a cross-sectional study.

Science.gov (United States)

Lee, Min-Su; Shin, Joon-Shik; Lee, Jinho; Lee, Yoon Jae; Kim, Me-riong; Park, Ki Byung; Shin, Dongjin; Cho, Jae-Heung; Ha, In-Hyuk

2015-12-01

Sleep duration holds considerable importance as an indicator of mental/physical health. The objective of this study was to investigate the association between sleep duration, mental health, and chronic disease prevalence in Koreans. Of 31,596 subjects eligible for the Korean National Health and Nutrition Examination Survey V (2010-2012), 17,638 participants who answered items on sleep duration (aged ≥ 19 yrs) were analyzed in a cross-sectional study. Association between sleep duration, mental health, and chronic disease prevalence was assessed using logistic regression, and adjusted for various socioeconomic and lifestyle characteristics. Short or long sleep duration showed correlations with mental health, and items of significance showed gender-specific patterns. Women displayed significant associations with stress and depressive symptoms, and men with stress, thoughts of suicide, and psychiatric counseling. While stress was related with short sleep duration in both genders, depressive symptoms showed a relationship with long duration in men, and short duration in women. Prevalence of any chronic disease was associated with ≤ 6 h sleep when adjusted for factors including mental health, and among chronic diseases, cancer and osteoarthritis showed associations with short sleep duration, while diabetes and dyslipidemia were associated with normal sleep duration. Mental health problems were associated with sleep duration with gender-specific patterns. Associations with osteoarthritis, cancer, diabetes, dyslipidemia and abnormal sleep duration persisted after adjustment for mental health.

No supernovae detected in two long-duration gamma-ray bursts.

Science.gov (United States)

Watson, D; Fynbo, J P U; Thöne, C C; Sollerman, J

2007-05-15

There is strong evidence that long-duration gamma-ray bursts (GRBs) are produced during the collapse of a massive star. In the standard version of the collapsar model, a broad-lined and luminous Type Ic core-collapse supernova (SN) accompanies the GRB. This association has been confirmed in observations of several nearby GRBs. Recent observations show that some long-duration GRBs are different. No SN emission accompanied the long-duration GRBs 060505 and 060614 down to limits fainter than any known Type Ic SN and hundreds of times fainter than the archetypal SN 1998bw that accompanied GRB 980425. Multi-band observations of the early afterglows, as well as spectroscopy of the host galaxies, exclude the possibility of significant dust obscuration. Furthermore, the bursts originated in star-forming galaxies, and in the case of GRB 060505, the burst was localized to a compact star-forming knot in a spiral arm of its host galaxy. We find that the properties of the host galaxies, the long duration of the bursts and, in the case of GRB 060505, the location of the burst within its host, all imply a massive stellar origin. The absence of an SN to such deep limits therefore suggests a new phenomenological type of massive stellar death.

The effects of odour and body posture on perceived duration

Directory of Open Access Journals (Sweden)

Eliane eSchreuder

2014-02-01

Full Text Available This study reports an examination of the internal clock model, according to which subjective time duration is influenced by attention and arousal state. In a time production task, we examine the hypothesis that an arousing odour and an upright body posture affect perceived duration.The experimental task was performed while participants were exposed to an odour and either sitting upright (arousing condition or lying down in a relaxing chair (relaxing condition. They were allocated to one of three experimental odour conditions: rosemary (arousing condition, peppermint (relaxing condition and no odour (control condition. The predicted effects of the odours were not borne out by the results. Self-reported arousal and pleasure states were measured before, during (after each body posture condition and post experimentally. Heart rate and skin conductance were measured before and during the experiment. As expected, odour had an effect on perceived duration. When participants were exposed to rosemary odour, they produced significantly shorter time intervals than in the no odour condition. This effect, however, could not be explained by increased arousal. There was no effect of body posture on perceived duration, even though body posture did induce arousal. The results do not support the proposed arousal mechanism of the internal clock model.

Understanding the role of sleep quality and sleep duration in commercial driving safety.

Science.gov (United States)

Lemke, Michael K; Apostolopoulos, Yorghos; Hege, Adam; Sönmez, Sevil; Wideman, Laurie

2016-12-01

Long-haul truck drivers in the United States suffer disproportionately high injury rates. Sleep is a critical factor in these outcomes, contributing to fatigue and degrading multiple aspects of safety-relevant performance. Both sleep duration and sleep quality are often compromised among truck drivers; however, much of the efforts to combat fatigue focus on sleep duration rather than sleep quality. Thus, the current study has two objectives: (1) to determine the degree to which sleep impacts safety-relevant performance among long-haul truck drivers; and (2) to evaluate workday and non-workday sleep quality and duration as predictors of drivers' safety-relevant performance. A non-experimental, descriptive, cross-sectional design was employed to collect survey and biometric data from 260 long-haul truck drivers. The Trucker Sleep Disorders Survey was developed to assess sleep duration and quality, the impact of sleep on job performance and accident risk, and other relevant work organization characteristics. Descriptive statistics assessed work organization variables, sleep duration and quality, and frequency of engaging in safety-relevant performance while sleepy. Linear regression analyses were conducted to evaluate relationships between sleep duration, sleep quality, and work organization variables with safety composite variables. Drivers reported long work hours, with over 70% of drivers working more than 11h daily. Drivers also reported a large number of miles driven per week, with an average of 2,812.61 miles per week, and frequent violations of hours-of-service rules, with 43.8% of drivers "sometimes to always" violating the "14-h rule." Sleep duration was longer, and sleep quality was better, on non-workdays compared on workdays. Drivers frequently operated motor vehicles while sleepy, and sleepiness impacted several aspects of safety-relevant performance. Sleep quality was better associated with driving while sleepy and with job performance and concentration

Association between sleep duration and sarcopenia among community-dwelling older adults: A cross-sectional study.

Science.gov (United States)

Hu, Xiaoyi; Jiang, Jiaojiao; Wang, Haozhong; Zhang, Lei; Dong, Birong; Yang, Ming

2017-03-01

Both sleep disorders and sarcopenia are common among older adults. However, little is known about the relationship between these 2 conditions.This study aimed to investigate the possible association between sleep duration and sarcopenia in a population of Chinese community-dwelling older adults.Community-dwelling older adults aged 60 years or older were recruited. Self-reported sleep duration, anthropometric data, gait speed, and handgrip strength were collected by face-to-face interviews. Sarcopenia was defined according to the recommended algorithm of the Asian Working Group for Sarcopenia (AWGS).We included 607 participants aged 70.6 ± 6.6 years (range, 60-90 years) in the analyses. The prevalence of sarcopenia in the whole study population was 18.5%. In women, the prevalence of sarcopenia was significantly higher in the short sleep duration group (hours) and long sleep duration group (>8 hours) compared with women in the normal sleep duration group (6-8 hours; 27.5%, 22.2% and 13.9%, respectively; P = .014). Similar results were found in men; however, the differences between groups were not statistically significant (18.5%, 20.6%, and 13.0%, respectively; P = .356). After adjustments for the potential confounding factors, older women having short sleep duration (OR: 4.34; 95% CI: 1.74-10.85) or having long sleep duration (OR: 2.50; 95% CI: 1.05-6.99) had greater risk of sarcopenia compared with women having normal sleep duration. With comparison to men with normal sleep duration, the adjusted OR for sarcopenia was 2.12 (0.96-8.39) in the short sleep duration group and 2.25 (0.88-6.87) in the long sleep duration group, respectively.A U-shape relationship between self-reported sleep duration and sarcopenia was identified in a population of Chinese community-dwelling older adults, especially in women.

Reflective optics

CERN Document Server

Korsch, Dietrich

1991-01-01

This is the first book dedicated exclusively to all-reflective imaging systems. It is a teaching tool as well as a practical design tool for anyone who specializes in optics, particularly for those interested in telescopes, infrared, and grazing-incidence systems. The first part of the book describes a unified geometric optical theory of all-reflective imaging systems (from near-normal to grazing incidence) developed from basic principles. The second part discusses correction methods and a multitude of closed-form solutions of well-corrected systems, supplemented with many conventional and unc

Reliability-Based Calibration of Load Duration Factors for Timber Structures

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Svensson, Staffan; Stang, Birgitte Friis Dela

2005-01-01

John Dalsgaard Sørensen, Staffan Svensson, Birgitte Dela Stang : Reliability-Based Calibration of Load Duration Factors for Timber Structures     Abstract :   The load bearing capacity of timber structures decrease with time depending on the type of load and timber. Based on representative limit...... states and stochastic models for timber structures, load duration factors are calibrated using probabilistic methods. Load duration e.ects are estimated on basis of simulation of realizations of wind, snow and imposed loads in accordance with the load models in the Danish structural codes. Three damage...... accumulation models are considered, namely Gerhards model, Barrett and Foschi _ s model and Foschi and Yao _ s model. The parameters in these models are .tted by the Maximum Likelihood Method using data relevant for Danish structural timber and the statistical uncertainty is quanti .ed. The reliability...

Gaze Duration Biases for Colours in Combination with Dissonant and Consonant Sounds: A Comparative Eye-Tracking Study with Orangutans.

Science.gov (United States)

Mühlenbeck, Cordelia; Liebal, Katja; Pritsch, Carla; Jacobsen, Thomas

2015-01-01

Research on colour preferences in humans and non-human primates suggests similar patterns of biases for and avoidance of specific colours, indicating that these colours are connected to a psychological reaction. Similarly, in the acoustic domain, approach reactions to consonant sounds (considered as positive) and avoidance reactions to dissonant sounds (considered as negative) have been found in human adults and children, and it has been demonstrated that non-human primates are able to discriminate between consonant and dissonant sounds. Yet it remains unclear whether the visual and acoustic approach-avoidance patterns remain consistent when both types of stimuli are combined, how they relate to and influence each other, and whether these are similar for humans and other primates. Therefore, to investigate whether gaze duration biases for colours are similar across primates and whether reactions to consonant and dissonant sounds cumulate with reactions to specific colours, we conducted an eye-tracking study in which we compared humans with one species of great apes, the orangutans. We presented four different colours either in isolation or in combination with consonant and dissonant sounds. We hypothesised that the viewing time for specific colours should be influenced by dissonant sounds and that previously existing avoidance behaviours with regard to colours should be intensified, reflecting their association with negative acoustic information. The results showed that the humans had constant gaze durations which were independent of the auditory stimulus, with a clear avoidance of yellow. In contrast, the orangutans did not show any clear gaze duration bias or avoidance of colours, and they were also not influenced by the auditory stimuli. In conclusion, our findings only partially support the previously identified pattern of biases for and avoidance of specific colours in humans and do not confirm such a pattern for orangutans.

Self-reported Sleep Duration and Subclinical Atherosclerosis in a General Population of Japanese Men

Science.gov (United States)

Suzuki, Sentaro; Arima, Hisatomi; Miyazaki, Soichiro; Fujiyoshi, Akira; Kadota, Aya; Takashima, Naoyuki; Hisamatsu, Takashi; Kadowaki, Sayaka; Zaid, Maryam; Torii, Sayuki; Horie, Minoru; Murata, Kiyoshi; Miura, Katsuyuki; Ueshima, Hirotsugu

2018-01-01

Aim: There are few data regarding associations between sleep duration and subclinical atherosclerosis in Japan. The aim of this study was to evaluate associations of self-reported sleep duration with calcification in the coronary arteries (CAC) and carotid intima media thickness (IMT) in Japanese men. Methods: This was a cross-sectional survey of 1093 randomly selected men from Kusatsu City, Japan. Average sleep duration on weekdays was estimated through questionnaire; CAC by computed tomography; and carotid IMT by ultrasonography. Results: The prevalence of CAC was 50.0% for participants with sleep duration 0.1). Conclusion: Self-reported sleep duration was not associated with increased CAC or carotid IMT in a general population of Japanese men. PMID:28747590

Effects of Internal Clock and Memory Disorders on Duration Reproductions and Duration Productions in Patients with Parkinson's Disease

Science.gov (United States)

Perbal, S.; Deweer, B.; Pillon, B.; Vidailhet, M.; Dubois, B.; Pouthas, V.

2005-01-01

Patients with Parkinson's disease (PD) exhibit deficits in perceptual and motor timing as well as impairments in memory and attentional processes that are related to dysfunction of dopaminergic systems in the basal ganglia. The aim of the present study was to assess the relationships existing between impaired duration judgments and defective…

Centimeter-Level Positioning Using an Efficient New Baseband Mixing and Despreading Method for Software GNSS Receivers

Directory of Open Access Journals (Sweden)

G. Lachapelle

2007-10-01

Full Text Available This paper presents an efficient new method for performing the baseband mixing and despreading operations in a software-based GNSS receiver, and demonstrates that the method is capable of providing measurements for centimeter-level positioning accuracy. The method uses a single frequency carrier replica for the baseband mixing process, enabling all satellites to perform mixing simultaneously and yielding considerable computational savings. To compensate for signal-to-noise ratio (SNR losses caused by using a single frequency carrier replica, the integration interval after despreading is divided into subintervals, and the output from each subinterval then compensated for the known frequency error. Using this approach, receiver processing times are shown to be reduced by approximately 21% relative to the next fastest method when tracking seven satellites. The paper shows the mathematical derivation of the new algorithm, discusses practical considerations, and demonstrates its performance using simulations and real data. Results show that the new method is able to generate pseudorange and carrier phase measurements with the same accuracy as traditional methods. Stand-alone positioning accuracy is at the meter level, while differential processing can produce fixed ambiguity carrier phase positions accurate to the centimeter level.

Association between Screen Viewing Duration and Sleep Duration, Sleep Quality, and Excessive Daytime Sleepiness among Adolescents in Hong Kong

Directory of Open Access Journals (Sweden)

Yim Wah Mak

2014-10-01

Full Text Available Screen viewing is considered to have adverse impacts on the sleep of adolescents. Although there has been a considerable amount of research on the association between screen viewing and sleep, most studies have focused on specific types of screen viewing devices such as televisions and computers. The present study investigated the duration with which currently prevalent screen viewing devices (including televisions, personal computers, mobile phones, and portable video devices are viewed in relation to sleep duration, sleep quality, and daytime sleepiness among Hong Kong adolescents (N = 762. Television and computer viewing remain prevalent, but were not correlated with sleep variables. Mobile phone viewing was correlated with all sleep variables, while portable video device viewing was shown to be correlated only with daytime sleepiness. The results demonstrated a trend of increase in the prevalence and types of screen viewing and their effects on the sleep patterns of adolescents.

Relationship between sleep duration and dietary intake in 4- to 14-year-old Danish children

DEFF Research Database (Denmark)

Hoppe, Camilla; Rothausen, Berit Worm; Biltoft-Jensen, Anja Pia

2013-01-01

A negative association between sleep duration and BMI has been observed in children. However, knowledge about the association between sleep duration and diet is limited. The objective was to examine the association between sleep duration and intake of foods and nutrients in children. In the present...... crosssectional study, dietary intake and sleep duration were recorded by the parents for seven consecutive days in a food and sleep record in a representative sample of 802 4- to 14-year-old children. No sex differences were found regarding age and sleep duration. Sleep duration was negatively correlated to age...... (ρ = –0·68; P duration was not associated with energy intake (b = –0·015; P = 0·20), but there was a trend towards a positive association with intake of dietary fibre (b = 0·006; P = 0·05) and vegetables (b = 0...

Induced abortion and subsequent pregnancy duration

DEFF Research Database (Denmark)

Zhou, Wei Jin; Sørensen, Henrik Toft; Olsen, Jørn

1999-01-01

OBJECTIVE: To examine whether induced abortion influences subsequent pregnancy duration. METHODS: Women who had their first pregnancies during 1980, 1981, and 1982 were identified in three Danish national registries. A total of 15,727 women whose pregnancies were terminated by first-trimester ind......OBJECTIVE: To examine whether induced abortion influences subsequent pregnancy duration. METHODS: Women who had their first pregnancies during 1980, 1981, and 1982 were identified in three Danish national registries. A total of 15,727 women whose pregnancies were terminated by first......-trimester induced abortions were compared with 46,026 whose pregnancies were not terminated by induced abortions. All subsequent pregnancies until 1994 were identified by register linkage. RESULTS: Preterm and post-term singleton live births were more frequent in women with one, two, or more previous induced...... abortions. After adjusting for potential confounders and stratifying by gravidity, the odds ratios of preterm singleton live births in women with one, two, or more previous induced abortions were 1.89 (95% confidence interval [CI] 1.70, 2.11), 2.66 (95% CI 2.09, 3.37), and 2.03 (95% CI 1.29, 3...

Duration in Poverty-Related Programs and Number of Child Maltreatment Reports.

Science.gov (United States)

Kim, Hyunil; Drake, Brett

2017-02-01

This study examined the relationship of a family's duration in poverty-related programs (i.e., Aid to Families with Dependent Children/Temporary Assistance for Needy Families and Medicaid) to the subject child's number of maltreatment reports while considering race and baseline neighborhood poverty. Children from a large Midwestern metropolitan area were followed through a linked cross-sector administrative database from birth to age 15. Generalized multilevel models were employed to account for the multilevel structure of the data (i.e., nesting of families within neighborhoods). The data showed a unique and significant contribution of duration in poverty-related programs to the number of maltreatment reports. The predicted number of maltreatment reports increased by between 2.5 and 3.7 times, as duration in poverty-related programs increased from 0 to 9 years. This relationship was consistent between Whites and non-Whites (over 98% Black), but non-Whites showed a significantly lower number of total maltreatment reports while controlling for duration in poverty-related programs. We were unable to find a significant association between child maltreatment reports and baseline neighborhood poverty.

Reflective Practice for Psychology Students: The Use of Reflective Journal Feedback in Higher Education

Science.gov (United States)

Bruno, Andreina; Dell'Aversana, Giuseppina

2017-01-01

Reflective journals have emerged as an effective means of monitoring and developing reflective practice in higher education, as part of a wider metacognitive strategy to transform traditional learning approaches. In addition, assessment procedures of reflective journals appear to be an important factor in enhancing commitment to learning and…

Guided and Unguided Student Reflections

OpenAIRE

Matheson, Amanda; Wood, Laura; Franklin, Scott V.

2017-01-01

Self-reflection is important metacognitive skill, enabling students to build coherence into their learning and embed content in a broader context. While various pedagogical techniques exist to encourage student reflection, little research has examined the differences between formally guided, partially guided and unguided reflections. This study focuses on student responses to online Guided Reflection Forms (GRFs) from students in a first-semester non-physics class and, separately, a sophomore...

Effectuation And Reflection-In-Action

DEFF Research Database (Denmark)

Gertsen, Frank; Lervang, Johan-Ulrik; Maack, Karl

2013-01-01

Our main aim is to facilitate a reflective methodology for MSc thesis students in practical entrepreneurship that draws on the ideas of ‘reflection-in-action’ while simultaneously making use of the effectuation logics.......Our main aim is to facilitate a reflective methodology for MSc thesis students in practical entrepreneurship that draws on the ideas of ‘reflection-in-action’ while simultaneously making use of the effectuation logics....

Interactive vs passive screen time and nighttime sleep duration among school-aged children.

Science.gov (United States)

Yland, Jennifer; Guan, Stanford; Emanuele, Erin; Hale, Lauren

2015-09-01

Insufficient sleep among school-aged children is a growing concern, as numerous studies have shown that chronic short sleep duration increases the risk of poor academic performance and specific adverse health outcomes. We examined the association between weekday nighttime sleep duration and 3 types of screen exposure: television, computer use, and video gaming. We used age 9 data from an ethnically diverse national birth cohort study, the Fragile Families and Child Wellbeing Study, to assess the association between screen time and sleep duration among 9-year-olds, using screen time data reported by both the child (n = 3269) and by the child's primary caregiver (n= 2770). Within the child-reported models, children who watched more than 2 hours of television per day had shorter sleep duration by approximately 11 minutes per night compared to those who watched less than 2 hours of television (β = -0.18; P computer use were associated with reduced sleep duration. For both child- and parent-reported screen time measures, we did not find statistically significant differences in effect size across various types of screen time. Screen time from televisions and computers is associated with reduced sleep duration among 9-year-olds, using 2 sources of estimates of screen time exposure (child and parent reports). No specific type or use of screen time resulted in significantly shorter sleep duration than another, suggesting that caution should be advised against excessive use of all screens.

Short Sleep Duration is Associated with Obesity in Hispanic Manufacturing Workers.

Science.gov (United States)

Benham, Grant; Ghaddar, Suad F; Talavera-Garza, Liza

2017-01-01

The present study examined the relationship between obesity and sleep duration among Hispanic manufacturing workers. Two hundred and twenty eight Hispanic workers from eight manufacturing plants completed an in-person interview that included measures of demographics, health literacy, and sleep duration. Height and weight were directly assessed. A logistic regression, controlling for gender, education, age, income, physical activity levels, self-reported health status, and health literacy, indicated that workers who slept six hours or less were significantly more likely to be obese than those sleeping seven to nine hours (OR: 1.90, 95% CI: 1.04-3.47). Our results extend previous research on the association between sleep duration and obesity to an understudied population of Hispanic workers.

Effects of farm management practices and transport duration on stress response and meat quality traits of suckling goat kids.

Science.gov (United States)

Alcalde, M J; Suárez, M D; Rodero, E; Álvarez, R; Sáez, M I; Martínez, T F

2017-09-01

Studies aimed to assess up to what extent farming and transport previous to slaughtering might affect physiology and meat quality in young goat kids are needed, with the ultimate purpose of promoting practices that minimize stress in these animals. In this regard the effects of on-farm management and transport duration on some physiological responses and meat quality parameters in goat kids were assessed. Two farms representing 'high' and 'low' welfare-friendly management practices were selected. In total, 32 suckling kids were withdrawn from each farm, transported by road for 2 or 6 h, and then slaughtered. Blood samples were collected both on-farm and in the slaughterhouse, and biochemistry, cell counts and haematocrit were determined. After slaughtering, carcass quality parameters were measured. Longissimus dorsi muscle was dissected and pH, colour parameters, water holding capacity and shear force were measured throughout 8-day ageing period. Results indicate that, regardless its duration, transport caused significant effects on some blood parameters suggesting stress in live animals, like glucose, cortisol or creatine kinase. Despite the marked stress status in animals, this condition was not decisively reflected on L. dorsi quality parameters, but some effects were observed regarding fat cover in carcasses and colour parameters. The results suggest that postmortem changes throughout ageing were more decisive in terms of meat quality than stressful management either on-farm or during transport.

Refining estimates of prescription durations by using observed covariates in pharmacoepidemiological databases

DEFF Research Database (Denmark)

Støvring, Henrik; Pottegård, Anton; Hallas, Jesper

2017-01-01

, patient sex and patient age as covariates. Results: The estimated prescription durations increased with redeemed amount and age. Women generally had longer prescription durations, which increased more with age than men. For 70-year-old women redeeming 300+ pills, we predicted a 95th percentile...... of the inter-arrival density of 225 (95%CI: 201, 249) days. For 50-year-old men redeeming 100 pills, the corresponding prediction was 97 (88, 106) days. Conclusions: The algorithm allows estimation of prescription durations based on the reverse WTD, which can depend upon observed covariates. Statistical...

Behavioral conflict, anterior cingulate cortex, and experiment duration: implications of diverging data.

Science.gov (United States)

Erickson, Kirk I; Milham, Michael P; Colcombe, Stanley J; Kramer, Arthur F; Banich, Marie T; Webb, Andrew; Cohen, Neal J

2004-02-01

We investigated the relationship between behavioral measures of conflict and the degree of activity in the anterior cingulate cortex (ACC). We reanalyzed an existing data set that employed the Stroop task using functional magnetic resonance imaging [Milham et al., Brain Cogn 2002;49:277-296]. Although we found no changes in the behavioral measures of conflict from the first to the second half of task performance, we found a reliable reduction in the activity of the anterior cingulate cortex. This result suggests the lack of a strong relationship between behavioral measurements of conflict and anterior cingulate activity. A concomitant increase in dorsolateral prefrontal cortex activity was also found, which may reflect a tradeoff in the neural substrates involved in supporting conflict resolution, detection, or monitoring processes. A second analysis of the data revealed that the duration of an experiment can dramatically affect interpretations of the results, including the roles in which particular regions are thought to play in cognition. These results are discussed in relation to current conceptions of ACC's role in attentional control. In addition, we discuss the implication of our results with current conceptions of conflict and of its instantiation in the brain. Hum. Brain Mapping 21:96-105, 2004. Copyright 2003 Wiley-Liss, Inc.

Creation, Identity and Reflection

Directory of Open Access Journals (Sweden)

Alina Beatrice Cheşcă

2015-05-01

Full Text Available The paper “Creation, Identity and Reflection” approaches the identification in the “mirror” of reality with creation, in other words seeking the authors’ identity in the reflected images. Reflection means attempting to find oneself, the mirror being the main principle of creation. Many characters become interesting only when they step into the world beyond the mirror, when their faces are doubled by the other self or when their selves are returned by other characters. The narcissistic concept of the mirror, i.e. the reflection in the mirror and the representation of the mirror itself, is a recurrent one in literature, but the reflection of the self which is not the self (as it is a reflection does not necessarily appear in a mirror or in a photograph or portrait. Sometimes, the not-self is returned to the self by another person or character. As far as Oscar Wilde’s theories are concerned, the main idea is that people are interesting for their masks, not for their inner nature. What Wilde calls “inner nature” is the characters’ un-reflected self and the mask is the reflection, the self in the mirror. Some characters’ relationships develop within a fiction that they dramatically try to preserve and protect with the risk of suffering. They refuse to take off the masks which define them in the others’ minds and hearts; the narcissistic individuals (both artists and characters seek and love their own image which they project upon facts, thus creating a fictive realm.

Tonic immobility and factors influencing its duration in rats.

Science.gov (United States)

Tikal, K

1991-01-01

The author developed a method for inducing tonic immobility (paroxysmal inhibition) in rats and mice. By means of a plexiglass plate and plexiglass box the rat is immobilised, rotated at 180 degrees and subjected to constant pressure corresponding to the weight of the plexiglass plate. This way it is possible to prolong substantially tonic immobility in rats without using foregoing time consuming and interfering, so called sensitizing procedures. The duration of TI can be influenced by pharmacologic and nonpharmacological interventions. A longer duration of TI appeared to be typical for rats tending to react in other situations with anxiety, motor inhibition and submission.

intensity, duration and frequency of rainstorms in lokoja

African Journals Online (AJOL)

Shuaibu et al.

This study analyzed the Intensity, duration and frequency (IDF) of rainstorms in Lokoja. ... INTRODUCTION. Rainfall worldwide has certain characteristics where it occurs. ..... State University of Science and Technology, Port. Harcourt, Nigeria.

The Cognitive Representation of Time and Duration

NARCIS (Netherlands)

Ulrich, Rolf; Rattat, Anne-Claire; Ogden, Ruth; Van Rijn, Hedderik; Bratzke, Daniel

How do people represent the duration of an event in memory and which mechanisms except timing are involved in processing and maintaining temporal information within the cognitive system? The speakers of this symposium will address this and related questions. Anne-Claire Rattat focuses on long-term

On pulse duration of self-terminating lasers

International Nuclear Information System (INIS)

Bokhan, P A

2011-01-01

The problem of the maximum pulse duration τ max of self-terminating lasers is considered. It is shown that the duration depends on the transition probability in the laser channel, on the decay rate of the resonant state in all other channels, and on the excitation rate of the metastable state. As a result, τ max is found to be significantly shorter than previously estimated. The criteria for converting the 'self-terminating' lasing to quasi-cw lasing are determined. It is shown that in the case of nonselective depopulation of the metastable state, for example in capillary lasers or in a fast flow of the active medium gas, it is impossible to obtain continuous lasing. Some concrete examples are considered. It is established that in several studies of barium vapour lasers (λ = 1.5 μm) and nitrogen lasers (λ = 337 nm), collisional lasing is obtained by increasing the relaxation rate of the metastable state in collisions with working particles (barium atoms and nitrogen molecules). (lasers)

Femoral Head Bone Loss Following Short and Long-Duration Spaceflight

Science.gov (United States)

Blaber, Elizabeth A.; Cheng-Campbell, Margareth A.; Almeida, Eduardo A. C.

2016-01-01

Exposure to mechanical unloading during spaceflight is known to have significant effects on the musculoskeletal system. Our ongoing studies with the mouse bone model have identified the failure of normal stem cell-based tissue regeneration, in addition to tissue degeneration, as a significant concern for long-duration spaceflight, especially in the mesenchymal and hematopoietic tissue lineages. The 30-day BionM1 and the 37-day Rodent Research 1 (RR1) missions enabled the possibility of studying these effects in long-duration microgravity experiments. We hypothesized that the inhibition of stem cell-based tissue regeneration in short-duration spaceflight would continue during long-duration spaceflight and furthermore would result in significant tissue alterations. MicroCT analysis of BionM1 femurs revealed 31 decrease in bone volume ratio, a 14 decrease in trabecular thickness, and a 20 decrease in trabecular number in the femoral head of space-flown mice. Furthermore, high-resolution MicroCT and immunohistochemical analysis of spaceflight tissues revealed a severe disruption of the epiphyseal boundary, resulting in endochondral ossification of the femoral head and perforation of articular cartilage by bone. This suggests that spaceflight in microgravity may cause rapid induction of an aging-like phenotype with signs of osteoarthritic disease in the hip joint. However, mice from RR1 exhibited significant bone loss in the femoral head but did not exhibit the severe aging and disease-like phenotype observed during BionM1. This may be due to increased physical activity in the RH hardware. Immunohistochemical analysis of the epiphyseal plate and investigation of cellular proliferation and differentiation pathways within the marrow compartment and whole bone tissue is currently being conducted to determine alterations in stem cell-based tissue regeneration between these experiments. Our results show that the observed inhibition of stem cell-based tissue regeneration

The association between sleep duration and physical performance in Chinese community-dwelling elderly.

Science.gov (United States)

Fu, Liyuan; Jia, Liye; Zhang, Wen; Han, Peipei; Kang, Li; Ma, Yixuan; Yu, Hairui; Zhai, Tianqi; Chen, Xiaoyu; Guo, Qi

2017-01-01

Physical performance is an important healthy factor in elder people. Good living habits, which include sleep, can maintain physical strength and physical performance. The aim of the present study was to conduct a cross-sectional study to determine the association between total sleep duration and physical performance. Our study population comprised residents of the township central hospital in the suburban of Tianjin, China. We measured muscle strength, walk speed and balance function by grip, 4-m walk test and timed up and go test (TUGT). We divided sleep duration into four groups 8-9h, >9h. A total 898 participants had completed data (392 men and 506 women, mean age 67.71 years). In man, adjusted sleep duration was associated with lower grip in > 9 h group, the mean value (95% CI) was 0.429 (0.409, 0.448), and longer TUGT time was also associated with long sleep duration, 10.46s (9.97 s, 10.95 s). In women, adjusted slower 4-m walk speed present an inverse U-shaped relation with sleep duration, by 0.93 m/s (0.86 m/s, 0.98 m/s), 0.97 m/s (0.96 m/s, 1.00 m/s), 0.97 m/s (0.95 m/s, 0.99 m/s) and 0.92 m/s (0.89 m/s, 0.96 m/s); longer TUGT time were associated with long sleep duration (> 9 h), by 11.23 s (10.70 s, 11.77 s). In Chinese community-dwelling elderly, lower muscle strength and lower balance function were associated with long sleep duration in men. Slower walk speed and lower balance function were associated with long sleep duration in women.

Maternal plasma cholesterol and duration of pregnancy: A prospective cohort study in Ghana.

Science.gov (United States)

Oaks, Brietta M; Stewart, Christine P; Laugero, Kevin D; Adu-Afarwuah, Seth; Lartey, Anna; Vosti, Stephen A; Ashorn, Per; Dewey, Kathryn G

2017-10-01

Low plasma cholesterol may be associated with preterm birth; however, results are mixed and limited primarily to high-income countries. Our objective was to determine whether maternal plasma lipid concentrations are associated with pregnancy duration. We performed a nested cohort (n = 320) study of pregnant Ghanaian women enrolled in a randomized controlled trial. Total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, and triglyceride concentrations were analyzed in plasma at ≤20and 36 weeks gestation as continuous variables and also categorized into low, referent, or high (90th percentile). At ≤20 weeks, plasma lipid concentrations were not associated with pregnancy duration. At 36 weeks, total cholesterol and triglyceride concentrations were not associated with pregnancy duration. Higher HDL-C at 36 weeks was associated with a longer pregnancy duration (adjusted β-coefficient ± standard error: 0.05 ± 0.02 days mg -1 /dL, p = .02); pregnancy duration was 5.9 ± 2.0 (mean ± standard error) days shorter among women with low HDL-C compared with the referent group (10th-90th percentile) (p = .02) and 8.6 ± 2.6 days shorter when compared with the high HDL-C group (p = .003). Pregnancy duration was 4.9 ± 2.1 days longer among women with low low-density lipoprotein cholesterol at 36 weeks gestation when compared with the referent group (p = .051). Our data suggest that low HDL-C in the third trimester of pregnancy is associated with a shorter duration of pregnancy in this study population but do not support the hypothesis that low total cholesterol is associated with a shorter pregnancy duration. © 2016 John Wiley & Sons Ltd.

High-throughput metataxonomic characterization of the raw milk microbiota identifies changes reflecting lactation stage and storage conditions.

Science.gov (United States)

Doyle, Conor J; Gleeson, David; O'Toole, Paul W; Cotter, Paul D

2017-08-16

Low temperature is used to control the growth of bacteria in milk, both pre- and post-pasteurization. As the duration of refrigerated storage extends, psychrotrophs dominate the milk microbiota, that can produce heat stable lipases which negatively impact the organoleptic qualities of milk. Here we examine the influence that refrigeration temperature (2°C, 4°C and 6°C) and storage duration (96h) have on the microbiota composition (16S profiling) of raw bulk tank milk (BTM). To reflect a proposed change to current farming practices, raw milk was blended after each milking (8 milkings) and stored for five consecutive days in each temperature-specific tank. Here 16S rRNA-based microbiota compositional analysis was performed after milk was collected on day 1 and again after the final addition of milk at day 5. In addition to assessing the impact of the duration and temperature of storage, the influence of lactation stage, i.e. mid- versus late-lactation, on the microbiota of the blended BTM was also examined. Overall, both temperature and length of storage had surprisingly little influence on the raw milk microbiota, other than an increase in proportions of Gammaproteobacteria in the blended milk samples collected after pooling on day 5, and in samples stored at 6°C. However, lactation stage had a considerable influence on microbiota composition, with milk from mid-lactation containing higher proportions of Bacteroides, Faecalibacterium, Campylobacter and Rhodanobacter, and late-lactation milk containing higher proportions of Actinobacteria. Overall, the study demonstrates that current temperature and storage duration practises impact the microbiota of raw milk, but these impacts are modest relative to the more considerable differences between mid and late-lactation milk. Copyright © 2017 Elsevier B.V. All rights reserved.

Noise frame duration, masking potency and whiteness of temporal noise

OpenAIRE

Kukkonen, Helja; Rovamo, Jyrki; Donner, Kristian; Tammikallio, Marja; Raninen, Antii

2002-01-01

PURPOSE. Because of the limited contrast range, increasing the duration of the noise frame is often the only option for increasing the masking potency of external, white temporal noise. This, however, reduces the high-frequency cutoff beyond which noise is no longer white. This study was conducted to determine the longest noise frame duration that produces the strongest masking effect and still mimics white noise on the detection of sinusoidal flicker. \\ud \\ud METHODS. Contrast energy thresho...

Sleep duration and ischemic heart disease and all-cause mortality

DEFF Research Database (Denmark)

Garde, Anne Helene; Hansen, Åse Marie; Holtermann, Andreas

2013-01-01

This prospective study aimed to examine if sleep duration is a risk indicator for ischemic heart disease (IHD) and all-cause mortality, and how perceived stress during work and leisure time and use of tranquilizers/hypnotics modifies the association.......This prospective study aimed to examine if sleep duration is a risk indicator for ischemic heart disease (IHD) and all-cause mortality, and how perceived stress during work and leisure time and use of tranquilizers/hypnotics modifies the association....

Two Types of Long-duration Quasi-static Evolution of Solar Filaments

Science.gov (United States)

Xing, C.; Li, H. C.; Jiang, B.; Cheng, X.; Ding, M. D.

2018-04-01

In this Letter, we investigate the long-duration quasi-static evolution of 12 pre-eruptive filaments (four active region (AR) and eight quiescent filaments), mainly focusing on the evolution of the filament height in 3D and the decay index of the background magnetic field. The filament height in 3D is derived through two-perspective observations of Solar Dynamics Observatory (SDO) and Solar TErrestrial RElations Observatory (STEREO). The coronal magnetic field is reconstructed using the potential field source surface model. A new finding is that the filaments we studied show two types of long-duration evolution: one type comprises a long-duration static phase and a short, slow rise phase with a duration of less than 12 hr and a speed of 0.1–0.7 km s‑1, while the other one only presents a slow rise phase but with an extremely long duration of more than 60 hr and a smaller speed of 0.01–0.2 km s‑1. At the moment approaching the eruption, the decay index of the background magnetic field at the filament height is similar for both AR and quiescent filaments. The average value and upper limit are ∼0.9 and ∼1.4, close to the critical index of torus instability. Moreover, the filament height and background magnetic field strength are also found to be linearly and exponentially related with the filament length, respectively.

[Interaction between quality and duration of sleep on the prevalence of type 2 diabetes].

Science.gov (United States)

Zhang, Pan; Lou, Peian; Chang, Guiqiu; Zhang, Lei; Chen, Peipei; Li, Ting; Qiao, Cheng; Dong, Zongmei

2014-09-01

To explore the effects related to quality and duration of sleep and their interactions on the prevalence of type-2 diabetes (T2DM). 9 622 people aged 18 years and over were recruited for our cross-sectional study during March 2013 to May 2013. Unconditional logistic regression was used to analyze the relationship between quality and duration of sleep on T2DM. Bootstrap was used to calculate the relative excess risk of interaction (RERI), the attributable proportion (AP) of interaction and the synergy index (SI). 95% confidence intervals (CI) of RERI, AP and SI were estimated. Concerning the comparison between cases and controls on both individual and total scores, other scores were all significantly different (P quality was higher than that in volunteers with good sleeping quality (P quality and short duration (OR = 4.78, 95% CI:3.32-6.99; P quality and 6-8 h sleep duration. The risk of T2DM still increased in people who had poor sleep or long duration (OR = 1.92, 95% CI:1.18-3.31; P interaction between poor sleep quality and short sleep duration, while 0.33 (-0.12-1.13), 0.17 (-0.03-0.51), 1.56 (0.76-2.74) for the interaction between good sleep quality and long sleep duration. Our results suggested that there were additive interactions between poor quality and shorter duration of sleep.

Relationship between Self-Reported Dietary Nutrient Intake and Self-Reported Sleep Duration among Japanese Adults

Directory of Open Access Journals (Sweden)

Yoko Komada

2017-02-01

Full Text Available Several studies have reported that short sleep duration is a risk factor for obesity and metabolic disease. Moreover, both sleep duration and sleep timing might independently be associated with dietary nutrient intake. In this study, we investigated the associations between self-reported sleep duration and dietary nutrient intake, with and without adjustments for variations in sleep timing (i.e., the midpoint of sleep. We conducted a questionnaire survey, comprising a validated brief self-administered diet history questionnaire (BDHQ and the Japanese version of the Pittsburgh Sleep Quality Index (PSQI among 1902 healthy Japanese adults and found that the dietary intakes of several nutrients correlated with sleep duration among men regardless of adjustment for the midpoint of sleep. Particularly, (1 small but significant correlations were observed between sleep duration and the percentage of energy from protein, regardless of adjustment for the midpoint of sleep; (2 energy-adjusted intakes of sodium, vitamin D, and vitamin B12 also significantly correlated with sleep duration; and (3 intakes of bread, pulses, and fish and shellfish correlated with sleep duration. In contrast, no significant correlations were observed between sleep duration and dietary intakes among women. This study revealed that after controlling for the midpoint of sleep, sleep duration correlated significantly with the dietary intake of specific nutrients and foods in a population of Japanese men.

How to play hot and cold on a line

NARCIS (Netherlands)

Haverkort, H.J.; Kübel, D.; Langetepe, E.; Schwarzwald, B.; Ellen, F.; Kolokolova, A.; Sack, J.-R.

2017-01-01

Suppose we are searching for a target point t in the unit interval. To pinpoint the location of t, we issue query points q 1 ,…,q n ∈[0,1] q1,…,qn∈[0,1] . As a response, we obtain an ordering of the query points by distance to t. This restricts possible locations of t to a subinterval. We define the

Laser-driven short-duration heating angioplasty: dilatation performance in cadaver atherosclerotic femoral arteries

Science.gov (United States)

Shimazaki, Natsumi; Naruse, Sho; Arai, Tsunenori; Imanishi, Nobuaki; Aiso, Sadakazu

2013-03-01

The purpose of this study was to investigate the artery dilatation performance of the short-duration heating balloon catheter in cadaver stenotic arteries. We designed a prototype short-duration heating balloon catheter that can heat artery media to around 60 °C in 15-25 s by a combination of laser-driven heat generation and continuous fluid irrigation in the balloon. We performed ex vivo short-duration heating dilatation in the cadaver atherosclerotic femoral arteries (initial percent diameter stenosis was 36-98%), with the maximum balloon temperature of 65+/-5 °C, laser irradiation duration of 25 s, and balloon dilatation pressure of 3.5 atm. The artery lumen configurations before and after the dilatations were assessed with a commercial IVUS system. After the short-duration heating dilatations, the percent diameter stenosis was reduced below 30% without any artery tears or dissections. We estimated that the artery media temperature was raised to around 60 °C in which plaque thickness was below 0.8 mm by a thermal conduction calculation. The estimated maximum temperature in artery adventitia and surrounding tissue was up to 45 °C. We found that the short-duration heating balloon could sufficiently dilate the cadaver stenotic arteries, without thermal injury in artery adventitia and surroundings.

Effect of winter cold duration on spring phenology of the orange tip butterfly, Anthocharis cardamines.

Science.gov (United States)

Stålhandske, Sandra; Lehmann, Philipp; Pruisscher, Peter; Leimar, Olof

2015-12-01

The effect of spring temperature on spring phenology is well understood in a wide range of taxa. However, studies on how winter conditions may affect spring phenology are underrepresented. Previous work on Anthocharis cardamines (orange tip butterfly) has shown population-specific reaction norms of spring development in relation to spring temperature and a speeding up of post-winter development with longer winter durations. In this experiment, we examined the effects of a greater and ecologically relevant range of winter durations on post-winter pupal development of A. cardamines of two populations from the United Kingdom and two from Sweden. By analyzing pupal weight loss and metabolic rate, we were able to separate the overall post-winter pupal development into diapause duration and post-diapause development. We found differences in the duration of cold needed to break diapause among populations, with the southern UK population requiring a shorter duration than the other populations. We also found that the overall post-winter pupal development time, following removal from winter cold, was negatively related to cold duration, through a combined effect of cold duration on diapause duration and on post-diapause development time. Longer cold durations also lead to higher population synchrony in hatching. For current winter durations in the field, the A. cardamines population of southern UK could have a reduced development rate and lower synchrony in emergence because of short winters. With future climate change, this might become an issue also for other populations. Differences in winter conditions in the field among these four populations are large enough to have driven local adaptation of characteristics controlling spring phenology in response to winter duration. The observed phenology of these populations depends on a combination of winter and spring temperatures; thus, both must be taken into account for accurate predictions of phenology.

Short sleep duration and dietary intake: epidemiological evidence, mechanisms, and health implications

Science.gov (United States)

Links between short sleep duration and obesity, type 2 diabetes, hypertension, and cardiovascular disease may be mechanistically mediated through changes in dietary intake. This review aims to provide an overview of recent epidemiologic studies on the relationships between habitual short sleep durat...

Students’ Learning through Reflective Journaling

OpenAIRE

Alvyda Liuolienė; Regina Metiūnienė

2011-01-01

The aim of the article is to get acquainted with the types of journals used in education to help students to learn. The paper presents some ways of fostering student’s learning through reflective journaling. It also describes the key aspects of a new method ARRIVE cycle in connection with teachers preparation to use reflective journals in a classroom. The article also presents self-assessment in reflective journaling and students’ need to self-evaluate their learning process. Reflective journ...

Selectively reflective transparent sheets

Science.gov (United States)

Waché, Rémi; Florescu, Marian; Sweeney, Stephen J.; Clowes, Steven K.

2015-08-01

We investigate the possibility to selectively reflect certain wavelengths while maintaining the optical properties on other spectral ranges. This is of particular interest for transparent materials, which for specific applications may require high reflectivity at pre-determined frequencies. Although there exist currently techniques such as coatings to produce selective reflection, this work focuses on new approaches for mass production of polyethylene sheets which incorporate either additives or surface patterning for selective reflection between 8 to 13 μ m. Typical additives used to produce a greenhouse effect in plastics include particles such as clays, silica or hydroxide materials. However, the absorption of thermal radiation is less efficient than the decrease of emissivity as it can be compared with the inclusion of Lambertian materials. Photonic band gap engineering by the periodic structuring of metamaterials is known in nature for producing the vivid bright colors in certain organisms via strong wavelength-selective reflection. Research to artificially engineer such structures has mainly focused on wavelengths in the visible and near infrared. However few studies to date have been carried out to investigate the properties of metastructures in the mid infrared range even though the patterning of microstructure is easier to achieve. We present preliminary results on the diffuse reflectivity using FDTD simulations and analyze the technical feasibility of these approaches.

Duration and speed of speech events: A selection of methods

Directory of Open Access Journals (Sweden)

Gibbon Dafydd

2015-07-01

Full Text Available The study of speech timing, i.e. the duration and speed or tempo of speech events, has increased in importance over the past twenty years, in particular in connection with increased demands for accuracy, intelligibility and naturalness in speech technology, with applications in language teaching and testing, and with the study of speech timing patterns in language typology. H owever, the methods used in such studies are very diverse, and so far there is no accessible overview of these methods. Since the field is too broad for us to provide an exhaustive account, we have made two choices: first, to provide a framework of paradigmatic (classificatory, syntagmatic (compositional and functional (discourse-oriented dimensions for duration analysis; and second, to provide worked examples of a selection of methods associated primarily with these three dimensions. Some of the methods which are covered are established state-of-the-art approaches (e.g. the paradigmatic Classification and Regression Trees, CART , analysis, others are discussed in a critical light (e.g. so-called ‘rhythm metrics’. A set of syntagmatic approaches applies to the tokenisation and tree parsing of duration hierarchies, based on speech annotations, and a functional approach describes duration distributions with sociolinguistic variables. Several of the methods are supported by a new web-based software tool for analysing annotated speech data, the Time Group Analyser.

Improved attenuation correction for respiratory gated PET/CT with extended-duration cine CT: a simulation study

Science.gov (United States)

Zhang, Ruoqiao; Alessio, Adam M.; Pierce, Larry A.; Byrd, Darrin W.; Lee, Tzu-Cheng; De Man, Bruno; Kinahan, Paul E.

2017-03-01

Due to the wide variability of intra-patient respiratory motion patterns, traditional short-duration cine CT used in respiratory gated PET/CT may be insufficient to match the PET scan data, resulting in suboptimal attenuation correction that eventually compromises the PET quantitative accuracy. Thus, extending the duration of cine CT can be beneficial to address this data mismatch issue. In this work, we propose to use a long-duration cine CT for respiratory gated PET/CT, whose cine acquisition time is ten times longer than a traditional short-duration cine CT. We compare the proposed long-duration cine CT with the traditional short-duration cine CT through numerous phantom simulations with 11 respiratory traces measured during patient PET/CT scans. Experimental results show that, the long-duration cine CT reduces the motion mismatch between PET and CT by 41% and improves the overall reconstruction accuracy by 42% on average, as compared to the traditional short-duration cine CT. The long-duration cine CT also reduces artifacts in PET images caused by misalignment and mismatch between adjacent slices in phase-gated CT images. The improvement in motion matching between PET and CT by extending the cine duration depends on the patient, with potentially greater benefits for patients with irregular breathing patterns or larger diaphragm movements.

Nitrous oxide-related postoperative nausea and vomiting depends on duration of exposure.

Science.gov (United States)

Peyton, Philip J; Wu, Christine Yx

2014-05-01

Inclusion of nitrous oxide in the gas mixture has been implicated in postoperative nausea and vomiting (PONV) in numerous studies. However, these studies have not examined whether duration of exposure was a significant covariate. This distinction might affect the future place of nitrous oxide in clinical practice. PubMed listed journals reporting trials in which patients randomized to a nitrous oxide or nitrous oxide-free anesthetic for surgery were included, where the incidence of PONV within the first 24 postoperative hours and mean duration of anesthesia was reported. Meta-regression of the log risk ratio for PONV with nitrous oxide (lnRR PONVN2O) versus duration was performed. Twenty-nine studies in 27 articles met the inclusion criteria, randomizing 10,317 patients. There was a significant relationship between lnRR PONVN2O and duration (r = 0.51, P = 0.002). Risk ratio PONV increased 20% per hour of nitrous oxide after 45 min. The number needed to treat to prevent PONV by avoiding nitrous oxide was 128, 23, and 9 where duration was less than 1, 1 to 2, and over 2 h, respectively. The risk ratio for the overall effect of nitrous oxide on PONV was 1.21 (CIs, 1.04-1.40); P = 0.014. This duration-related effect may be via disturbance of methionine and folate metabolism. No clinically significant effect of nitrous oxide on the risk of PONV exists under an hour of exposure. Nitrous oxide-related PONV should not be seen as an impediment to its use in minor or ambulatory surgery.

Association between QRS duration on prehospital ECG and mortality in patients with suspected STEMI

DEFF Research Database (Denmark)

Hansen, Rikke; Frydland, Martin; Møller-Helgestad, Ole Kristian

2017-01-01

BACKGROUND: QRS duration has previously shown association with mortality in patients with acute myocardial infarction treated with thrombolytics, less is known in patients with suspected ST segment elevation myocardial infarction (STEMI) when assessing QRS duration on prehospital ECG. Thus......, the objective was to investigate the prognostic effect of QRS duration on prehospital ECG and presence of classic left and right bundle branch block (LBBB/RBBB) for all-cause mortality in patients with suspected STEMI. METHOD: In total 2105 consecutive patients (mean age 64±13years, 72% men) with suspected...... STEMI were prospectively included. QRS duration was registered from automated QRS measurement on prehospital ECG and patients were divided according to quartiles of QRS duration (111ms). Primary endpoint was all-cause 30-day mortality. Predictors of all-cause mortality were...

Perioperative self-reflection among surgical residents.

Science.gov (United States)

Peshkepija, Andi N; Basson, Marc D; Davis, Alan T; Ali, Muhammad; Haan, Pam S; Gupta, Rama N; Hardaway, John C; Nebeker, Cody A; McLeod, Michael K; Osmer, Robert L; Anderson, Cheryl I

2017-09-01

We studied prevalence and predictors of meaningful self-reflection among surgical residents and with prompting/structured interventions, sought to improve/sustain resident skills. Residents from six programs recorded 1032 narrative self-reflective comments (120 residents), using a web-based platform. If residents identified something learned or to be improved, self-reflection was deemed meaningful. Independent variables PGY level, resident/surgeon gender, study site/Phase1: July2014-August2015 vs. Phase2: September2015-September2016) were analyzed. Meaningful self-reflection was documented in 40.6% (419/1032) of entries. PGY5's meaningfully self-reflected less than PGY1-4's, 26.1% vs. 49.6% (p = 0.002). In multivariate analysis, resident narratives during Phase 2 were 4.7 times more likely to engage in meaningful self-reflection compared to Phase1 entries (p self-reflection, compared to Phase1. Surgical residents uncommonly practice meaningful self-reflection, even when prompted, and PGY5/chief residents reflect less than more junior residents. Substantial/sustained improvements in resident self-reflection can occur with both training and interventions. Copyright © 2017 Elsevier Inc. All rights reserved.

Personal growth following long-duration spaceflight

Science.gov (United States)

Suedfeld, Peter; Brcic, Jelena; Johnson, Phyllis J.; Gushin, Vadim

2012-10-01

IntroductionSalutogenesis and posttraumatic growth represent personal growth and improved functioning as a result of experiencing major challenging events. These developments are not simply resilience (a return to a baseline level of well-being), but positive change in such characteristics as self-understanding, relations with others, personal values, and life goals. Space agencies and space psychologists, primarily concerned with deleterious effects and their countermeasures, have not paid much attention to such beneficial long-term aftereffects of spaceflight. PurposeTo document what changes veterans of the Soviet/Russian space program report as a consequence of their experiences. MethodTwenty retired male cosmonauts Mir and/or ISS cosmonauts filled out relevant self-report questionnaires. Results: Although there was little change in the relative rankings of a list of values, the scale showed an overall increase in the rated importance of all personal values, although only the increase in Self-Direction reached statistical significance. Responses to one of two post-space growth questionnaires based on the Post-Traumatic Growth Inventory (PTGI) were compared to the means of two comparison groups: 152 first-time mothers, and 926 respondents who had experienced various forms of trauma. The cosmonauts reported higher scores on the dimension of New Possibilities when compared to the new mothers and the traumatized group, and higher scores on Personal Strength and Overall PTG compared to the latter. Respondents who had spent more than a year in space, and those who flew on both Mir and ISS, were the most likely to report positive change in the domain Appreciation of Life. The other post-space career questionnaire reflected major changes in Perceptions of the Earth and of Space, and increases on a number of other dimensions, including New Possibilities and Changes in Daily Life, with positive scores that significantly exceeded the original report. DiscussionIt appears

Short sleep duration and dietary intake: epidemiologic evidence, mechanisms, and health implications

Science.gov (United States)

Links between short sleep duration and obesity, type 2 diabetes, hypertension, and cardiovascular disease may be mediated through changes in dietary intake. This review provides an overview of recent epidemiologic studies on the relations between habitual short sleep duration and dietary intake in a...

24 CFR 266.606 - Mortgage insurance premium: Duration and method of paying.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Mortgage insurance premium... AFFORDABLE MULTIFAMILY PROJECT LOANS Contract Rights and Obligations Mortgage Insurance Premiums § 266.606 Mortgage insurance premium: Duration and method of paying. (a) Duration of payments. Mortgage insurance...

ANALYSIS OF THE DURATION OF UNEMPLOYMENT IN ROMANIA

Directory of Open Access Journals (Sweden)

ROMANESCU GEORGE OCTAVIAN

2016-06-01

Full Text Available In the context of industrialization and expansion of wage labor is the difference between work and employment. The rigidity of the labor supply and its persistent surplus is explained by the very high compensation or unemployment benefits, through trade union action or error preset number of employees, which leads to greater gap between supply and demand for labor. Adjustment policies of employment in the future will be increasingly less state policy, of general application, and increasingly more political will and enterprise branch, the subject of an active social dialogue between employers and trade unions, dialogue resulted in agreements of limited duration and subject to revision depending on the economic and social situation. The duration of work and organizational modalities they will depend on this social dialogue.

Modeling and Forecasting Persistent Financial Durations

Czech Academy of Sciences Publication Activity Database

Žikeš, F.; Baruník, Jozef; Shenai, N.

2017-01-01

Roč. 36, č. 10 (2017), s. 1081-1110 ISSN 0747-4938 R&D Projects: GA ČR GA13-32263S EU Projects: European Commission 612955 - FINMAP Institutional support: RVO:67985556 Keywords : price durations * long memory * multifractal models * realized volatility * Whittle estimation Subject RIV: AH - Economics OBOR OECD: Applied Economics , Econometrics Impact factor: 1.333, year: 2016 http://library.utia.cas.cz/separaty/2014/E/barunik-0434201.pdf

On the reflection point where light reflects to a known destination on quadratic surfaces.

Science.gov (United States)

Gonçalves, Nuno

2010-01-15

We address the problem of determining the reflection point on a specular surface where a light ray that travels from a source to a target is reflected. The specular surfaces considered are those expressed by a quadratic equation. So far, there is no closed form explicit equation for the general solution of this determination of the reflection point, and the usual approach is to use the Snell law or the Fermat principle whose equations are derived in multidimensional nonlinear minimizations. We prove in this Letter that one can impose a set of three restrictions to the reflection point that can impose a set of three restrictions that culminates in a very elegant formalism of searching the reflection point in a unidimensional curve in space. This curve is the intersection of two quadratic equations. Some applications of this framework are also discussed.

Association between sleep duration and obesity is modified by dietary macronutrients intake in Korean.

Science.gov (United States)

Doo, Miae; Kim, Yangha

2016-01-01

Short sleep duration has been reported to be inversely associated with risk of obesity. The effects of sleep duration on obesity-related variables and the interaction of sleep duration and dietary macronutrients consumption on risk of obesity were analysed in 14,111 subjects aged 20-79 from the Korean National Health and Nutrition Examination Survey. Sleep restriction to less than 7h per day resulted in higher body mass index, plasma triglyceride level, and obesity prevalence for women, but not for men. Protein intake was significantly lower in subjects with lower sleep duration for both men and women. The subjects with short sleep duration were significantly higher fat consumption for men, whereas carbohydrate consumption for women. Among subjects whose carbohydrate consumption was above the median, subjects with sleep duration of less than 7h per day increased their odds of being obese (OR=1.255, 95% CI: 1.073-1.476, Pmacronutrients consumption in women subjects. Copyright © 2015 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

Monitoring the Impacts of Forest Management on Snowpack Duration

Science.gov (United States)

O'Halloran, T.; Tyler, S.; Gaffney, R.; Pai, H.

2017-12-01

Seasonal snowpack constitutes a significant portion of the hydrologic budget in mountain watersheds and influences dynamic (e.g., runoff magnitude and timing, soil moisture availability) and energetic processes (e.g., surface-atmosphere energy fluxes, ground temperature). Altered forest structure can affect snow accumulation and ablation. As part of a long-term monitoring project, this work examines the impact of forest management practices on snow cover in Lassen National Forest, California. We deployed a fiber optic distributed temperature sensing (DTS) cable and multiple meteorological stations in thinned, clear-cut, and untreated areas of forest. The DTS data was collected at 1 meter spatial intervals every 4 hours from February to May 2017. To determine snow cover, daily temperature variations were examined along locations of the DTS cable associated with our areas of interest. Between the various treatments, snow duration was greater in both clear-cut and untreated forest compared to the thinned area. However, snow duration varied by only six days. We also investigated other meteorological forcings, such as average winter temperature and precipitation, which coupled with forest modifications could explain snow duration in our study.

Reflection in Russian Educational Psychology.

Science.gov (United States)

Nelissen, Jo M. C.; Tomic, Welko

This paper discusses the cultural-historical school founded by Vygotsky, Luria, and Leontiev as the theoretical background of Russian educational psychologists who have been studying how children learn to reflect. Two approaches to reflection are examined within the cultural-historical tradition: first, reflection--like other higher psychological…

Self-reflection, gender and science achievement

Science.gov (United States)

Shoop, Kathleen A.

Drawing on socio-cognitive learning theory, this study compared achievement scores of 134 male and female high school biology students randomly assigned to groups which either used self-reflection, used self-reflection and received feedback, or did not self-reflect. Following a pretest, the teacher provided self-reflection strategy instruction to students in the two intervention groups and then subsequently provided in-class self-reflection time for these groups. The posttest concluded the unit; the retention measure was five weeks later. A quasi-experimental 3 x 3 x 2 (time x intervention x gender) factorial repeated-measures control group design was used for this study; a repeated measures ANOVA and several one-way ANOVA's were used to answer the research questions. Results from the repeated-measures ANOVA revealed significant results for Time and Time x Intervention, with the reflection group demonstrating significantly lower gains from pretest to posttest than the other two groups. The ANOVA examining differences between those who reflected and those who reflected and received feedback provided significant results with similar results for the difference between the control group and the reflection group. For teachers and students this study provides several areas of practical significance. Primarily, teachers may find lower student achievement if students regularly self-reflect but do not receive feedback for their reflection.

The influence of stimulus phase duration on discomfort and electrically induced torque of quadriceps femoris

Directory of Open Access Journals (Sweden)

Richard E. Liebano

2013-10-01

Full Text Available BACKGROUND: Although a number of studies have compared the influence of different electrical pulse parameters on maximum electrically induced torque (MEIT and discomfort, the role of phase duration has been poorly investigated. OBJECTIVE: To examine the variation in muscle torque and discomfort produced when electrically stimulating quadriceps femoris using pulsed current with three different phase durations in order to establish whether there are any advantages or disadvantages in varying the phase duration over the range examined. METHOD: This is a two repeated-measures, within-subject study conducted in a research laboratory. The study was divided into 2 parts with 19 healthy young adults in each part.In part 1, MEIT was determined for each phase duration (400, 700, and 1000 µs, using a biphasic pulsed current at a frequency of 50 Hz. In part 2, stimulus amplitude was increased until the contractions reached 40% of maximum voluntary isometric contraction (MVIC and the associated discomfort produced by each phase duration was measured. RESULTS: In part 1 of the study, we found that the average MEITs generated with each phase duration (400, 700, and 1000 µs were 55.0, 56.3, and 58.0% of MVIC respectively, but the differences were not statistically significant (p=.45. In part 2, we found a statistically significant increase in discomfort over the same range of phase durations. The results indicate that, for a given level of torque production, discomfort increases with increasing phase duration (p=.008. CONCLUSIONS: Greater muscle torque cannot be produced by increasing the stimulus phase duration over the range examined. Greater discomfort is produced by increasing the stimulus phase duration.

Learning the language of time: Children's acquisition of duration words.

Science.gov (United States)

Tillman, Katharine A; Barner, David

2015-05-01

Children use time words like minute and hour early in development, but take years to acquire their precise meanings. Here we investigate whether children assign meaning to these early usages, and if so, how. To do this, we test their interpretation of seven time words: second, minute, hour, day, week, month, and year. We find that preschoolers infer the orderings of time words (e.g., hour>minute), but have little to no knowledge of the absolute durations they encode. Knowledge of absolute duration is learned much later in development - many years after children first start using time words in speech - and in many children does not emerge until they have acquired formal definitions for the words. We conclude that associating words with the perception of duration does not come naturally to children, and that early intuitive meanings of time words are instead rooted in relative orderings, which children may infer from their use in speech. Copyright © 2015 Elsevier Inc. All rights reserved.

Operating room scheduling and surgeon assignment problem under surgery durations uncertainty.