Associations between prolonged sedentary time and breaks in sedentary time with cardiometabolic risk in 10-14-year-old children: The HAPPY study.

Science.gov (United States)

Bailey, Daniel P; Charman, Sarah J; Ploetz, Thomas; Savory, Louise A; Kerr, Catherine J

2017-11-01

This study examines the association between prolonged sedentary time and breaks in sedentary time with cardiometabolic risk in 10-14-year-old children. This cross-sectional design study analysed accelerometry-determined sedentary behaviour and physical activity collected over 7 days from 111 (66 girls) UK schoolchildren. Objective outcome measures included waist circumference, fasting lipids, fasting glucose, blood pressure, and cardiorespiratory fitness. Logistic regression was used for the main data analysis. After adjustment for confounders, the odds of having hypertriglyceridaemia (P = 0.03) and an increased clustered cardiometabolic risk score (P = 0.05) were significantly higher in children who engaged in more prolonged sedentary bouts per day. The number of breaks in sedentary time per day was not associated with any cardiometabolic risk factor, but longer mean duration of daily breaks in sedentary time were associated with a lower odds of having abdominal adiposity (P = 0.04) and elevated diastolic blood pressure (P = 0.01). These associations may be mediated by engagement in light activity. This study provides evidence that avoiding periods of prolonged uninterrupted sedentary time may be important for reducing cardiometabolic disease risk in children.

Typewriting rate as a function of reaction time.

Science.gov (United States)

Hayes, V; Wilson, G D; Schafer, R L

1977-12-01

This study was designed to determine the relationship between reaction time and typewriting rate. Subjects were 24 typists ranging in age from 19 to 39 yr. Reaction times (.001 sec) to a light were recorded for each finger and to each alphabetic character and three punctuation marks. Analysis of variance yielded significant differences in reaction time among subjects and fingers. Correlation between typewriting rate and average reaction time to the alphabetic characters and three punctuation marks was --.75. Correlation between typewriting rate and the difference between the reaction time of the hands was --.42. Factors influencing typewriting rate may include reaction time of the fingers, difference between the reaction time of the hands, and reaction time to individual keys on the typewriter. Implications exist for instructional methodology and further research.

A detailed description of the short-term musculoskeletal and cognitive effects of prolonged standing for office computer work.

Science.gov (United States)

Baker, Richelle; Coenen, Pieter; Howie, Erin; Lee, Jeremy; Williamson, Ann; Straker, Leon

2018-07-01

Due to concerns about excessive sedentary exposure for office workers, alternate work positions such as standing are being trialled. However, prolonged standing may have health and productivity impacts, which this study assessed. Twenty adult participants undertook two hours of laboratory-based standing computer work to investigate changes in discomfort and cognitive function, along with muscle fatigue, movement, lower limb swelling and mental state. Over time, discomfort increased in all body areas (total body IRR [95% confidence interval]: 1.47[1.36-1.59]). Sustained attention reaction time (β = 18.25[8.00-28.51]) deteriorated, while creative problem solving improved (β = 0.89[0.29-1.49]). There was no change in erector spinae, rectus femoris, biceps femoris or tibialis anterior muscle fatigue; low back angle changed towards less  lordosis, pelvis movement increased, lower limb swelling increased and mental state decreased. Body discomfort was positively correlated with mental state. The observed changes suggest replacing office work sitting with standing should be done with caution. Practitioner Summary: Standing is being used to replace sitting by office workers; however, there are health risks associated with prolonged standing. In a laboratory study involving 2 h prolonged standing discomfort increased (all body areas), reaction time and mental state deteriorated while creative problem-solving improved. Prolonged standing should be undertaken with caution.

Effect of prolonging radiation delivery time on retention of gammaH2AX

International Nuclear Information System (INIS)

Moiseenko, Vitali; Banáth, Judit P; Duzenli, Cheryl; Olive, Peggy L

2008-01-01

Compared to conventional external beam radiotherapy, IMRT requires significantly more time to deliver the dose. Prolonging dose delivery potentially increases DNA repair which would reduce the biological effect. We questioned whether retention of γH2AX, a measure of lack of repair of DNA damage, would decrease when dose delivery was protracted. Exponentially growing SiHa cervical carinoma cells were irradiated with 6 MV photons in a water tank using a VarianEX linear accelerator. Cells held at 37°C received 2 Gy in 0.5 min and 4 Gy in 1 min. To evaluate effect of dose delivery prolongation, 2 and 4 Gy were delivered in 30 and 60 min. After 24 h recovery, cells were analyzed for clonogenic survival and for residual γH2AX as measured using flow cytometry. Increasing the dose delivery time from 0.5 or 1 min to 30 or 60 min produced a signficant increase in cell survival from 0.45 to 0.48 after 2 Gy, and from 0.17 to 0.20 after 4 Gy. Expression of residual γH2AX decreased from 1.27 to 1.22 relative to background after 2 Gy and 1.46 to 1.39 relative to background after 4 Gy, but differences were not statistically significant. The relative differences in the slopes of residual γH2AX versus dose for acute versus prolonged irradiation bordered on significant (p = 0.055), and the magnitude of the change was consistent with the observed increase in surviving fraction. These results support the concept that DNA repair underlies the increase in survival observed when dose delivery is prolonged. They also help to establish the limits of sensitivity of residual γH2AX, as measured using flow cytometry, for detecting differences in response to irradiation

The Significance of Prolonged and Saddleback Fever in Hospitalised Adult Dengue.

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Deborah Hl Ng

Full Text Available Dengue fever is gaining importance in Singapore with an increase in the number of cases and mortality in recent years. Although prolonged and saddleback fever have been reported in dengue fever, there are no specific studies on their significance in dengue. This study aims to examine the prevalence of prolonged and saddleback fever in dengue as well as their associations with dengue severity. A total of 2843 polymerase-chain reaction (PCR confirmed dengue patients admitted to Tan Tock Seng Hospital from 2004 to 2008 were included in the study. Sixty-nine percent of them were male with a median age of 34 years. Prolonged fever (fever > 7 days duration was present in 572 (20.1% of patients. Dengue hemorrhagic fever (DHF, dengue shock syndrome (DSS and severe dengue (SD were significantly more likely to occur in patients with prolonged fever. Mucosal bleeding, anorexia, diarrhea, abdominal pain, nausea or vomiting, lethargy, rash, clinical fluid accumulation, hepatomegaly, nosocomial infection, leukopenia, higher neutrophil count, higher hematocrit, higher alanine transaminase (ALT and aspartate transaminase (AST, higher creatinine, lower protein and prolonged activated partial thromboplastin time (APTT were significantly associated with prolonged fever but not platelet count or prothrombin time (PT. Saddleback fever was present in 165 (5.8%. Although DHF and SD were more likely to occur in patients in those with saddleback fever, DSS was not. Compared with prolonged fever, saddleback fever did not show many significant associations except for diarrhea, abdominal pain, clinical fluid accumulation, hematocrit and platelet change, and lower systolic blood pressure. This study demonstrates that prolonged fever may be associated with various warning signs and more severe forms of dengue (SD, DSS, DHF, while saddleback fever showed associations with DHF and SD but not DSS. The presence of prolonged or saddleback fever in dengue patients should therefore

[Pathophysiology of prolonged hypokinesia].

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Kovalenko, E A

1976-01-01

Hypokinesia is an important problem in modern medicine. In the pathogenetic effect of prolonged hypokinesia the main etiological factor is diminished motor activity; of major importance are disorders in the energy and plastic metabolism which affect the muscle system; the contributing factors are cardiovascular deconditioning and orthostatic intolerance. This is attributed to a decreased oxygen supply and eliminated hydrostatic influences during a prolonged recumbency. Blood redistribution in the vascular bed is related to the Gauer-Henry reflex and subsequent changes in the fluid-electrolyte balance. Decreased load on the bone system induces changes in the protein-phosphate-calcium metabolism, diminished bone density and increased calcium content in the blood and urine. Changes in the calcium metabolism are systemic. The activity of the higher nervous system and reflex functions is lowered. Changes in the function of the autonomic nervous system which include a noticeable decline of its adaptive-trophic role as a result of the decrease of afferent and efferent impulsation are of great importance. Changes in the hormonal function involve a peculiar stress-reaction which develops at an early stage of hypokinesia as a response to an unusual situation. Prolonged hypokinesia may result in a disturbed function of the pituitary-adrenal system. It is assumed that prolonged hypokinesia may induce a specific disease of hypokinesia during which man cannot lead a normal mode of life and work.

Cybersickness provoked by head-mounted display affects cutaneous vascular tone, heart rate and reaction time.

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Nalivaiko, Eugene; Davis, Simon L; Blackmore, Karen L; Vakulin, Andrew; Nesbitt, Keith V

2015-11-01

Evidence from studies of provocative motion indicates that motion sickness is tightly linked to the disturbances of thermoregulation. The major aim of the current study was to determine whether provocative visual stimuli (immersion into the virtual reality simulating rides on a rollercoaster) affect skin temperature that reflects thermoregulatory cutaneous responses, and to test whether such stimuli alter cognitive functions. In 26 healthy young volunteers wearing head-mounted display (Oculus Rift), simulated rides consistently provoked vection and nausea, with a significant difference between the two versions of simulation software (Parrot Coaster and Helix). Basal finger temperature had bimodal distribution, with low-temperature group (n=8) having values of 23-29 °C, and high-temperature group (n=18) having values of 32-36 °C. Effects of cybersickness on finger temperature depended on the basal level of this variable: in subjects from former group it raised by 3-4 °C, while in most subjects from the latter group it either did not change or transiently reduced by 1.5-2 °C. There was no correlation between the magnitude of changes in the finger temperature and nausea score at the end of simulated ride. Provocative visual stimulation caused prolongation of simple reaction time by 20-50 ms; this increase closely correlated with the subjective rating of nausea. Lastly, in subjects who experienced pronounced nausea, heart rate was elevated. We conclude that cybersickness is associated with changes in cutaneous thermoregulatory vascular tone; this further supports the idea of a tight link between motion sickness and thermoregulation. Cybersickness-induced prolongation of reaction time raises obvious concerns regarding the safety of this technology. Copyright © 2015 Elsevier Inc. All rights reserved.

Cardiovascular drugs inducing QT prolongation: facts and evidence.

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Taira, Carlos A; Opezzo, Javier A W; Mayer, Marcos A; Höcht, Christian

2010-01-01

Acquired QT syndrome is mainly caused by the administration of drugs that prolong ventricular repolarization. On the other hand, the risk of drug-induced torsades de pointes is increased by numerous predisposing factors, such as genetic predisposition, female sex, hypokalemia and cardiac dysfunction. This adverse reaction is induced by different chemical compounds used for the treatment of a variety of pathologies, including arrhythmias. As it is known, antiarrhythmic agents and other cardiovascular drugs can prolong the QT interval, causing this adverse reaction. Of the 20 most commonly reported drugs, 10 were cardiovascular agents and these appeared in 348 of the reports (46%). Class Ia antiarrhythmic agents have frequently been linked to inducing arrhythmia, including torsades de pointes. Sotalol and amiodarone, class III antiarrhythmics, are known to prolong the QT interval by blocking I(Kr). Due to the severity of events caused by the therapeutic use of these drugs, in this work of revision the cardiovascular drugs that present this property and the factors and evidence will be mentioned.

The in vivo study on the radiobiologic effect of prolonged delivery time to tumor control in C57BL mice implanted with Lewis lung cancer

International Nuclear Information System (INIS)

Wang, Xin; Xiong, Xiao-Peng; Lu, Jiade; Zhu, Guo-Pei; He, Shao-Qin; Hu, Chao-Su; Ying, Hong-Mei

2011-01-01

High-precision radiation therapy techniques such as IMRT or sterotactic radiosurgery, delivers more complex treatment fields than conventional techniques. The increased complexity causes longer dose delivery times for each fraction. The purpose of this work is to explore the radiobiologic effect of prolonged fraction delivery time on tumor response and survival in vivo. 1-cm-diameter Lewis lung cancer tumors growing in the legs of C57BL mice were used. To evaluate effect of dose delivery prolongation, 18 Gy was divided into different subfractions. 48 mice were randomized into 6 groups: the normal control group, the single fraction with 18 Gy group, the two subfractions with 30 min interval group, the seven subfractions with 5 min interval group, the two subfractions with 60 min interval group and the seven subfractions with 10 min interval group. The tumor growth tendency, the tumor growth delay and the mice survival time were analyzed. The tumor growth delay of groups with prolonged delivery time was shorter than the group with single fraction of 18 Gy (P < 0.05). The tumor grow delay of groups with prolonged delivery time 30 min was longer than that of groups with prolonged delivery time 60 min P < 0.05). There was no significant difference between groups with same delivery time (P > 0.05). Compared to the group with single fraction of 18 Gy, the groups with prolonged delivery time shorten the mice survival time while there was no significant difference between the groups with prolonged delivery time 30 min and the groups with prolonged delivery time 60 min. The prolonged delivery time with same radiation dose shorten the tumor growth delay and survival time in the mice implanted with Lewis lung cancer. The anti-tumor effect decreased with elongation of the total interfractional time

Prolonged displacement may compromise resilience in Eritrean ...

African Journals Online (AJOL)

Objective: to assess the impact of prolonged displacement on the resilience of Eritrean mothers. Methods: an adapted SOC scale (short form) was administered. Complementary qualitative data were gathered from study participants' spontaneous reactions to and commentaries on the SOC scale. Results: Displaced ...

Predicting time on prolonged benefits for injured workers with acute back pain.

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Steenstra, Ivan A; Busse, Jason W; Tolusso, David; Davilmar, Arold; Lee, Hyunmi; Furlan, Andrea D; Amick, Ben; Hogg-Johnson, Sheilah

2015-06-01

Some workers with work-related compensated back pain (BP) experience a troubling course of disability. Factors associated with delayed recovery among workers with work-related compensated BP were explored. This is a cohort study of workers with compensated BP in 2005 in Ontario, Canada. Follow up was 2 years. Data was collected from employers, employees and health-care providers by the Workplace Safety and Insurance Board (WSIB). Exclusion criteria were: (1) no-lost-time claims, (2) >30 days between injury and claim filing, (3) benefits duration, and (4) age >65 years. Using proportional hazard models, we examined the prognostic value of information collected in the first 4 weeks after injury. Outcome measures were time on benefits during the first episode and time until recurrence after the first episode. Of 6,657 workers, 1,442 were still on full benefits after 4 weeks. Our final model containing age, physical demands, opioid prescription, union membership, availability of a return-to-work program, employer doubt about work-relatedness of injury, worker's recovery expectations, participation in a rehabilitation program and communication of functional ability was able to identify prolonged claims to a fair degree [area under the curve (AUC) = .79, 95% confidence interval (CI) .74-.84]. A model containing age, sex, physical demands, opioid prescription and communication of functional ability was less successful at predicting time until recurrence (AUC = .61, 95% CI .57, .65). Factors contained in information currently collected by the WSIB during the first 4 weeks on benefits can predict prolonged claims, but not recurrent claims.

QT interval prolongation associated with sibutramine treatment

Science.gov (United States)

Harrison-Woolrych, Mira; Clark, David W J; Hill, Geraldine R; Rees, Mark I; Skinner, Jonathan R

2006-01-01

Aims To investigate a possible association of sibutramine with QT interval prolongation. Methods Post-marketing surveillance using prescription event monitoring in the New Zealand Intensive Medicines Monitoring Programme (IMMP) identified a case of QT prolongation and associated cardiac arrest in a patient taking sibutramine for 25 days. This patient was further investigated, including genotyping for long QT syndrome. Other IMMP case reports suggesting arrhythmias associated with sibutramine were assessed and further reports were obtained from the World Health Organisation (WHO) adverse drug reactions database. Results The index case displayed a novel mutation in a cardiac potassium channel subunit gene, KCNQ1, which is likely to prolong cardiac membrane depolarization and increase susceptibility to long QT intervals. Assessment of further IMMP reports identified five additional patients who experienced palpitations associated with syncope or presyncopal symptoms, one of whom had a QTc at the upper limit of normal. Assessment of reports from the WHO database identified three reports of QT prolongation and one fatal case of torsade de pointes in a patient also taking cisapride. Conclusions This case series suggests that sibutramine may be associated with QT prolongation and related dysrhythmias. Further studies are required, but in the meantime we would recommend that sibutramine should be avoided in patients with long QT syndrome and in patients taking other medicines that may prolong the QT interval. PMID:16542208

Observation of prolonged coherence time of the collective spin wave of an atomic ensemble in a paraffin-coated 87Rb vapor cell

International Nuclear Information System (INIS)

Jiang Shuo; Luo Xiaoming; Chen Liqing; Ning Bo; Chen Shuai; Wang Jingyang; Zhong Zhiping; Pan Jianwei

2009-01-01

We report a prolonged coherence time of the collective spin wave of a thermal 87 Rb atomic ensemble in a paraffin-coated cell. The spin wave is prepared through a stimulated Raman process. The long coherence time is achieved by prolonging the lifetime of the spins with paraffin coating and minimize dephasing with optimal experimental configuration. The observation of the long-time-delayed-stimulated Stokes signal in the writing process suggests the prolonged lifetime of the prepared spins; a direct measurement of the decay of anti-Stokes signal in the reading process shows the coherence time is up to 300 μs after minimizing dephasing. This is 100 times longer than the reported coherence time in the similar experiments in thermal atomic ensembles based on the Duan-Lukin-Cirac-Zoller and its improved protocols. This prolonged coherence time sets the upper limit of the memory time in quantum repeaters based on such protocols, which is crucial for the realization of long-distance quantum communication. The previous reported fluorescence background in the writing process due to collision in a sample cell with buffer gas is also reduced in a cell without buffer gas.

Impact of Azithromycin on Pregnancy Prolongation in Women at Risk of Preterm Labor: A Time-to-Event Analysis.

Science.gov (United States)

Goyer, Isabelle; Ferland, Gabrielle; Ruo, Ni; Morin, Caroline; Brochet, Marie-Sophie; Morin, Lucie; Ferreira, Ema

2016-09-13

Since 2006, the empiric use of azithromycin in women at risk of premature birth has become prevalent in our institution without any evidence of its efficacy. Although antibiotics can prolong pregnancy in preterm prolonged rupture of membranes, no published data are available for women with intact membranes. To describe the purpose of adding azithromycin to the usual treatments (cerclage, tocolysis, rest, etc.) to prolong pregnancy in women with intact membranes who are at risk of or already in preterm labour. A retrospective observational cohort study was done at a Mother-Child University Hospital Centre. Patients admitted to obstetric ward who received azithromycin between January 1 st , 2006 and August 1 st , 2010 were included. A total of 127 exposed women were matched to 127 controls through medical records and pharmacy software. A time-to-event analysis was done to compare gestational age at the time of the recorded composite event (delivery, or rupture of membranes, or second intervention to prolong pregnancy). To compare proportions of composite event at different time points, χ 2 tests were used. Patients who received azithromycin had a more severe condition at presentation. Once adjusted for confounding factors, prolongation of pregnancy (HR =1.049; CI 95%: 0.774-1.421 [p=0.758]) and gestational age at the event (HR=1.200; CI 95%: 0.894-1.609 [p=0.225]) did not differ between the groups. The proportions of women with an event ≥7 days post-diagnosis or ≥37 gestational weeks were similar. Azithromycin was added to medical therapy in a more at-risk population and no clear benefit was measured.

The Eschenmoser coupling reaction under continuous-flow conditions

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Singh, Sukhdeep; Köhler, J Michael; Schober, Andreas

2011-01-01

Summary The Eschenmoser coupling is a useful carbon–carbon bond forming reaction which has been used in various different synthesis strategies. The reaction proceeds smoothly if S-alkylated ternary thioamides or thiolactames are used. In the case of S-alkylated secondary thioamides or thiolactames, the Eschenmoser coupling needs prolonged reaction times and elevated temperatures to deliver valuable yields. We have used a flow chemistry system to promote the Eschenmoser coupling under enhanced reaction conditions in order to convert the demanding precursors such as S-alkylated secondary thioamides and thiolactames in an efficient way. Under pressurized reaction conditions at about 220 °C, the desired Eschenmoser coupling products were obtained within 70 s residence time. The reaction kinetics was investigated and 15 examples of different building block combinations are given. PMID:21915222

The Eschenmoser coupling reaction under continuous-flow conditions

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Sukhdeep Singh

2011-08-01

Full Text Available The Eschenmoser coupling is a useful carbon–carbon bond forming reaction which has been used in various different synthesis strategies. The reaction proceeds smoothly if S-alkylated ternary thioamides or thiolactames are used. In the case of S-alkylated secondary thioamides or thiolactames, the Eschenmoser coupling needs prolonged reaction times and elevated temperatures to deliver valuable yields. We have used a flow chemistry system to promote the Eschenmoser coupling under enhanced reaction conditions in order to convert the demanding precursors such as S-alkylated secondary thioamides and thiolactames in an efficient way. Under pressurized reaction conditions at about 220 °C, the desired Eschenmoser coupling products were obtained within 70 s residence time. The reaction kinetics was investigated and 15 examples of different building block combinations are given.

Progranulin inhibits platelet aggregation and prolongs bleeding time in rats.

Science.gov (United States)

Al-Yahya, A M; Al-Masri, A A; El Eter, E A; Hersi, A; Lateef, R; Mawlana, O

2018-05-01

Several adipokines secreted by adipose tissue have an anti-thrombotic and anti-atherosclerotic function. Recently identified adipokine progranulin was found to play a protective role in atherosclerosis. Bearing in mind the central role of platelets in inflammation and atherosclerosis, we aimed, in this study, to examine the effect of progranulin on platelet function and coagulation profile in rats. Healthy male albino Wistar rats weighing (250-300 g) were divided into 4 groups. Three groups were given increasing doses of progranulin (0.001 µg, 0.01 µg, and 0.1 µg) intraperitoneally, while the control group received phosphate-buffered saline (PBS). Bleeding time, prothrombin time, activated partial thromboplastin time and platelet aggregation responses to adenosine diphosphate and arachidonic acid were assessed. Administration of progranulin resulted in a significant inhibition of platelet aggregation in response to both adenosine diphosphate, and arachidonic acid. Bleeding time, prothrombin time and activated partial thromboplastin time were significantly prolonged in all groups that received progranulin, in particular, the 0.1 µg dose, in comparison to the control group. This preliminary data is first suggesting that the antiplatelet and anticoagulant action of progranulin could have a physiological protective function against thrombotic disorders associated with obesity and atherosclerosis. However, these results merit further exploration.

The in vivo study on the radiobiologic effect of prolonged delivery time to tumor control in C57BL mice implanted with Lewis lung cancer

Directory of Open Access Journals (Sweden)

Zhu Guo-Pei

2011-01-01

Full Text Available Abstract Background High-precision radiation therapy techniques such as IMRT or sterotactic radiosurgery, delivers more complex treatment fields than conventional techniques. The increased complexity causes longer dose delivery times for each fraction. The purpose of this work is to explore the radiobiologic effect of prolonged fraction delivery time on tumor response and survival in vivo. Methods 1-cm-diameter Lewis lung cancer tumors growing in the legs of C57BL mice were used. To evaluate effect of dose delivery prolongation, 18 Gy was divided into different subfractions. 48 mice were randomized into 6 groups: the normal control group, the single fraction with 18 Gy group, the two subfractions with 30 min interval group, the seven subfractions with 5 min interval group, the two subfractions with 60 min interval group and the seven subfractions with 10 min interval group. The tumor growth tendency, the tumor growth delay and the mice survival time were analyzed. Results The tumor growth delay of groups with prolonged delivery time was shorter than the group with single fraction of 18 Gy (P 0.05. Compared to the group with single fraction of 18 Gy, the groups with prolonged delivery time shorten the mice survival time while there was no significant difference between the groups with prolonged delivery time 30 min and the groups with prolonged delivery time 60 min. Conclusions The prolonged delivery time with same radiation dose shorten the tumor growth delay and survival time in the mice implanted with Lewis lung cancer. The anti-tumor effect decreased with elongation of the total interfractional time.

The Effect of Sports and Physical Activity on Elderly Reaction Time and Response Time

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Abdolrahman Khezri

2014-07-01

Full Text Available Objectives: Physical activities ameliorate elderly motor and cognitive performance. The aim of this research is to study the effect of sport and physical activity on elderly reaction time and response time. Methods & Materials: The research method is causal-comparative and its statistical population consists of 60 active and non-active old males over 60 years residing at Mahabad city. Reaction time was measured by reaction timer apparatus, made in Takei Company (YB1000 model. Response time was measured via Nelson’s Choice- Response Movement Test. At first, reaction time and then response time was measured. For data analysis, descriptive statistic, K-S Test and One Sample T Test were used Results K-S Test show that research data was parametric. According to the results of this research, physical activity affected reaction time and response time. Results: of T test show that reaction time (P=0.000 and response time (P=0.000 of active group was statistically shorter than non- active group. Conclusion: The result of current study demonstrate that sport and physical activity, decrease reaction and response time via psychomotor and physiological positive changes.

Effect of prolonged gelling time on the intrinsic properties of barium alginate microcapsules and its biocompatibility.

Science.gov (United States)

Vaithilingam, Vijayaganapathy; Kollarikova, Gabriella; Qi, Meirigeng; Lacik, Igor; Oberholzer, Jose; Guillemin, Gilles J; Tuch, Bernard E

2011-01-01

Pericapsular fibrotic overgrowth (PFO) may be attributed to an immune response against microcapsules themselves or to antigen shedding through microcapsule pores from encapsulated islet tissue. Modification of microcapsules aimed at reducing pore size should prevent PFO and improve graft survival. This study investigated the effect of increased gelling time (20 vs. 2 min) in barium chloride on intrinsic properties of alginate microcapsules and tested their biocompatibility in vivo. Prolonged gelling time affected neither permeability nor size of the microcapsules. However, prolonged gelling time for 20 min produced brittle microcapsules compared to 2 min during compression test. Encapsulation of human islets in both types of microcapsules affected neither islet viability nor function. The presence of PFO when transplanted into a large animal model such as baboon and its absence in small animal models such as rodents suggest that the host immune response towards alginate microcapsules is species rather than alginate specific.

9. Nuclear power plant service life prolongation

International Nuclear Information System (INIS)

Evropin, S.V.

1998-01-01

The problem of prolongation of nuclear power plant service life duration is discussed. A schematic diagram of the program developed in the course of activities dealing with NPP service time prolongation is shown and analyzed in details. It is shown that the basic moment when determining the strategy for NPP service time prolongation is the positive confirmation of the agreement between the NPP safety provisions and modern safety requirements. The other very important aspect of the problem is engineering substantiation of the measures assuring the reactor operation prolongation. The conclusion is made that available methods of recovering reactor materials properties, main components repair and replacement, the modern techniques for nondestructive testing of metals and NPP pipelines, as well as the developed approaches to reactor facility safety improvements make the prolongation of the Russian NPP service lifetimes possible from engineering viewpoint and economically desirable

Prolonged sedentary time and physical activity in workplace and non-work contexts: a cross-sectional study of office, customer service and call centre employees.

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Thorp, Alicia A; Healy, Genevieve N; Winkler, Elisabeth; Clark, Bronwyn K; Gardiner, Paul A; Owen, Neville; Dunstan, David W

2012-10-26

To examine sedentary time, prolonged sedentary bouts and physical activity in Australian employees from different workplace settings, within work and non-work contexts. A convenience sample of 193 employees working in offices (131), call centres (36) and customer service (26) was recruited. Actigraph GT1M accelerometers were used to derive percentages of time spent sedentary (customer service workers were typically the least sedentary and the most active at work. The workplace is a key setting for prolonged sedentary time, especially for some occupational groups, and the potential health risk burden attached requires investigation. Future workplace regulations and health promotion initiatives for sedentary occupations to reduce prolonged sitting time should be considered.

Finite-time barriers to reaction front propagation

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Locke, Rory; Mahoney, John; Mitchell, Kevin

2015-11-01

Front propagation in advection-reaction-diffusion systems gives rise to rich geometric patterns. It has been shown for time-independent and time-periodic fluid flows that invariant manifolds, termed burning invariant manifolds (BIMs), serve as one-sided dynamical barriers to the propagation of reaction front. More recently, theoretical work has suggested that one-sided barriers, termed burning Lagrangian Coherent structures (bLCSs), exist for fluid velocity data prescribed over a finite time interval, with no assumption on the time-dependence of the flow. In this presentation, we use a time-varying fluid ``wind'' in a double-vortex channel flow to demonstrate that bLCSs form the (locally) most attracting or repelling fronts.

The effects of acute bout of cycling on auditory & visual reaction times.

Science.gov (United States)

Ashnagar, Zinat; Shadmehr, Azadeh; Jalaei, Shohreh

2015-04-01

The purpose of this study was to investigate the effects of an acute bout of cycling exercise on auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction time. 29 subjects were randomly divided into experimental and control groups. The subjects of the experimental group carried out a single bout of submaximal cycling exercise. The auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction times were measured before and after the exercise session. The reaction time tests were taken from the subjects by using Speed Anticipation and Reaction Tester (SART) software. In the control group, the reaction time tests were performed by the subjects with an interval of 30 min. In the experimental group, the percentage changes of mean auditory choice and complex choice reaction time values were significantly decreased in comparison with the control group (P visual choice and complex choice reaction times were decreased after the exercise, the changes were not significant (P > 0.05). An acute bout of cycling exercise improved the speed of auditory and visual reaction times in healthy young females. However, these positive changes were significantly observed only in the auditory reaction time tests in comparison with the control group. Copyright © 2014 Elsevier Ltd. All rights reserved.

Autonomous Vehicles: Disengagements, Accidents and Reaction Times.

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Vinayak V Dixit

Full Text Available Autonomous vehicles are being viewed with scepticism in their ability to improve safety and the driving experience. A critical issue with automated driving at this stage of its development is that it is not yet reliable and safe. When automated driving fails, or is limited, the autonomous mode disengages and the drivers are expected to resume manual driving. For this transition to occur safely, it is imperative that drivers react in an appropriate and timely manner. Recent data released from the California trials provide compelling insights into the current factors influencing disengagements of autonomous mode. Here we show that the number of accidents observed has a significantly high correlation with the autonomous miles travelled. The reaction times to take control of the vehicle in the event of a disengagement was found to have a stable distribution across different companies at 0.83 seconds on average. However, there were differences observed in reaction times based on the type of disengagements, type of roadway and autonomous miles travelled. Lack of trust caused by the exposure to automated disengagements was found to increase the likelihood to take control of the vehicle manually. Further, with increased vehicle miles travelled the reaction times were found to increase, which suggests an increased level of trust with more vehicle miles travelled. We believe that this research would provide insurers, planners, traffic management officials and engineers fundamental insights into trust and reaction times that would help them design and engineer their systems.

Autonomous Vehicles: Disengagements, Accidents and Reaction Times.

Science.gov (United States)

Dixit, Vinayak V; Chand, Sai; Nair, Divya J

2016-01-01

Autonomous vehicles are being viewed with scepticism in their ability to improve safety and the driving experience. A critical issue with automated driving at this stage of its development is that it is not yet reliable and safe. When automated driving fails, or is limited, the autonomous mode disengages and the drivers are expected to resume manual driving. For this transition to occur safely, it is imperative that drivers react in an appropriate and timely manner. Recent data released from the California trials provide compelling insights into the current factors influencing disengagements of autonomous mode. Here we show that the number of accidents observed has a significantly high correlation with the autonomous miles travelled. The reaction times to take control of the vehicle in the event of a disengagement was found to have a stable distribution across different companies at 0.83 seconds on average. However, there were differences observed in reaction times based on the type of disengagements, type of roadway and autonomous miles travelled. Lack of trust caused by the exposure to automated disengagements was found to increase the likelihood to take control of the vehicle manually. Further, with increased vehicle miles travelled the reaction times were found to increase, which suggests an increased level of trust with more vehicle miles travelled. We believe that this research would provide insurers, planners, traffic management officials and engineers fundamental insights into trust and reaction times that would help them design and engineer their systems.

Autonomous Vehicles: Disengagements, Accidents and Reaction Times

Science.gov (United States)

Dixit, Vinayak V.; Chand, Sai; Nair, Divya J.

2016-01-01

Autonomous vehicles are being viewed with scepticism in their ability to improve safety and the driving experience. A critical issue with automated driving at this stage of its development is that it is not yet reliable and safe. When automated driving fails, or is limited, the autonomous mode disengages and the drivers are expected to resume manual driving. For this transition to occur safely, it is imperative that drivers react in an appropriate and timely manner. Recent data released from the California trials provide compelling insights into the current factors influencing disengagements of autonomous mode. Here we show that the number of accidents observed has a significantly high correlation with the autonomous miles travelled. The reaction times to take control of the vehicle in the event of a disengagement was found to have a stable distribution across different companies at 0.83 seconds on average. However, there were differences observed in reaction times based on the type of disengagements, type of roadway and autonomous miles travelled. Lack of trust caused by the exposure to automated disengagements was found to increase the likelihood to take control of the vehicle manually. Further, with increased vehicle miles travelled the reaction times were found to increase, which suggests an increased level of trust with more vehicle miles travelled. We believe that this research would provide insurers, planners, traffic management officials and engineers fundamental insights into trust and reaction times that would help them design and engineer their systems. PMID:27997566

Sleep restriction may lead to disruption in physiological attention and reaction time

Directory of Open Access Journals (Sweden)

Arbind Kumar Choudhary

2016-07-01

Full Text Available Sleepiness is the condition where for some reason fails to go into a sleep state and will have difficulty in remaining awake even while carrying out activities. Sleep restriction occurs when an individual fails to get enough sleep due to high work demands. The mechanism between sleep restriction and underlying brain physiology deficits is not well assumed. The objective of the present study was to investigate the mental attention (P300 and reaction time [visual (VRT and auditory (ART] among night watchmen, at subsequent; first (1st day, fourth (4th day and seventh (7th day of restricted sleep period. After exclusion and inclusion criteria, the study was performed among 50 watchmen (age=18–35 years (n=50 after providing written informed consent and divided into two group. Group I-(Normal sleep (n=28 working in day time and used to have normal sleep in night (≥8 h; Group II-(Restricted sleep (n=22 - working in night time and used to have less sleep in night (≤3 h. Statistical significance between the different groups was determined by the independent student ʻtʼ test and the significance level was fixed at p≤0.05. We observed that among all normal and restricted sleep watchmen there was not any significant variation in Karolinska Sleepiness Scale (KSS score, VRT and ART, along with latency and amplitude of P300 on 1st day of restricted sleep. However at subsequent on 4th day and 7th day of restricted sleep, there was significant increase in (KSSscore, and prolongation of VRT and ART as well as alteration in latency and amplitude of P300 wave in restricted sleep watchmen when compare to normal sleep watchmen. The present finding concludes that loss of sleep has major impact in dynamic change in mental attention and reaction time among watchmen employed in night shift. Professional regulations and work schedules should integrate sleep schedules before and during the work period as an essential dimension for their healthy life.

Sleep restriction may lead to disruption in physiological attention and reaction time.

Science.gov (United States)

Choudhary, Arbind Kumar; Kishanrao, Sadawarte Sahebrao; Dadarao Dhanvijay, Anup Kumar; Alam, Tanwir

2016-01-01

Sleepiness is the condition where for some reason fails to go into a sleep state and will have difficulty in remaining awake even while carrying out activities. Sleep restriction occurs when an individual fails to get enough sleep due to high work demands. The mechanism between sleep restriction and underlying brain physiology deficits is not well assumed. The objective of the present study was to investigate the mental attention (P300) and reaction time [visual (VRT) and auditory (ART)] among night watchmen, at subsequent; first (1st) day, fourth (4th) day and seventh (7th) day of restricted sleep period. After exclusion and inclusion criteria, the study was performed among 50 watchmen (age=18-35 years) (n=50) after providing written informed consent and divided into two group. Group I-(Normal sleep) (n=28) working in day time and used to have normal sleep in night (≥8 h); Group II-(Restricted sleep) (n=22) - working in night time and used to have less sleep in night (≤3 h). Statistical significance between the different groups was determined by the independent student ' t ' test and the significance level was fixed at p≤0.05. We observed that among all normal and restricted sleep watchmen there was not any significant variation in Karolinska Sleepiness Scale (KSS) score, VRT and ART, along with latency and amplitude of P300 on 1st day of restricted sleep. However at subsequent on 4th day and 7th day of restricted sleep, there was significant increase in (KSS)score, and prolongation of VRT and ART as well as alteration in latency and amplitude of P300 wave in restricted sleep watchmen when compare to normal sleep watchmen. The present finding concludes that loss of sleep has major impact in dynamic change in mental attention and reaction time among watchmen employed in night shift. Professional regulations and work schedules should integrate sleep schedules before and during the work period as an essential dimension for their healthy life.

No Evidence of Reaction Time Slowing in Autism Spectrum Disorder

Science.gov (United States)

Ferraro, F. Richard

2016-01-01

A total of 32 studies comprising 238 simple reaction time and choice reaction time conditions were examined in individuals with autism spectrum disorder (n?=?964) and controls (n?=?1032). A Brinley plot/multiple regression analysis was performed on mean reaction times, regressing autism spectrum disorder performance onto the control performance as…

Ringer's lactate, but not hydroxyethyl starch, prolongs the food intolerance time after major abdominal surgery; an open-labelled clinical trial.

Science.gov (United States)

Li, Yuhong; He, Rui; Ying, Xiaojiang; Hahn, Robert G

2015-05-06

The infusion of large amounts of Ringer's lactate prolongs the functional gastrointestinal recovery time and increases the number of complications after open abdominal surgery. We performed an open-labelled clinical trial to determine whether hydroxyethyl starch or Ringer's lactate exerts these adverse effects when the surgery is performed by laparoscopy. Eighty-eight patients scheduled for major abdominal cancer surgery (83% by laparoscopy) received a first-line fluid treatment with 9 ml/kg of either 6% hydroxyethyl starch 130/0.4 (Voluven) or Ringer's lactate, just after induction of anaesthesia; this was followed by a second-line infusion with 12 ml/kg of either starch or Ringer's lactate over 1 hour. Further therapy was managed at the discretion of the attending anaesthetist. Outcome data consisted of postoperative gastrointestinal recovery time, complications and length of hospital stay. The order of the infusions had no impact on the outcome. Both the administration of ≥ 2 L of Ringer's lactate and the development of a surgical complication were associated with a longer time period of paralytic ileus and food intolerance (two-way ANOVA, P food intolerance time amounted to 2 days each. The infusion of ≥ 1 L of hydroxyethyl starch did not adversely affect gastrointestinal recovery. Ringer's lactate, but not hydroxyethyl starch, prolonged the gastrointestinal recovery time in patients undergoing laparoscopic cancer surgery. Surgical complications prolonged the hospital stay.

In vivo relaxation time measurements on a murine tumor model--prolongation of T1 after photodynamic therapy.

Science.gov (United States)

Liu, Y H; Hawk, R M; Ramaprasad, S

1995-01-01

RIF tumors implanted on mice feet were investigated for changes in relaxation times (T1 and T2) after photodynamic therapy (PDT). Photodynamic therapy was performed using Photofrin II as the photosensitizer and laser light at 630 nm. A home-built proton solenoid coil in the balanced configuration was used to accommodate the tumors, and the relaxation times were measured before, immediately after, and up to several hours after therapy. Several control experiments were performed untreated tumors, tumors treated with Photofrin II alone, or tumors treated with laser light alone. Significant increases in T1s of water protons were observed after PDT treatment. In all experiments, 31P spectra were recorded before and after the therapy to study the tumor status and to confirm the onset of PDT. These studies show significant prolongation of T1s after the PDT treatment. The spin-spin relaxation measurements, on the other hand, did not show such prolongation in T2 values after PDT treatment.

Prolonged excretion of a low-pathogenicity H5N2 avian influenza virus strain in the Pekin duck

Science.gov (United States)

Carranza-Flores, José Manuel; Padilla-Noriega, Luis; Loza-Rubio, Elizabeth

2013-01-01

H5N2 strains of low-pathogenicity avian influenza virus (LPAIV) have been circulating for at least 17 years in some Mexican chicken farms. We measured the rate and duration of viral excretion from Pekin ducks that were experimentally inoculated with an H5N2 LPAIV that causes death in embryonated chicken eggs (A/chicken/Mexico/2007). Leghorn chickens were used as susceptible host controls. The degree of viral excretion was evaluated with real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) using samples from oropharyngeal and cloacal swabs. We observed prolonged excretion from both species of birds lasting for at least 21 days. Prolonged excretion of LPAIV A/chicken/Mexico/2007 is atypical. PMID:23820212

Comparison of Sprint Reaction and Visual Reaction Times of Athletes in Different Branches

Science.gov (United States)

Akyüz, Murat; Uzaldi, Basar Basri; Akyüz, Öznur; Dogru, Yeliz

2017-01-01

The aims of this study are to analyse sprint reaction and visual reaction times of female athletes of different branches competing in Professional leagues and to show the differences between them. 42 voluntary female athletes from various branches of Professional leagues of Istanbul (volleyball, basketball, handball) were included in the…

Comparing of the Reaction Time in Substance-Dependent and Non-Dependent Individuals

Directory of Open Access Journals (Sweden)

Mohammad Narimani

2012-11-01

Full Text Available Aim: The aim of this study was to compare the simple, selective, and discrimination reaction time in substance-dependent and non-dependent individuals. Method: In this causal-comparative study, the population included of 425 males (opium and crystal dependents who were referred to addiction rehabilitation centers in Tabriz. By random sampling, 16 opium dependents, 16 crystal dependents, and 16 non-dependent individuals with no history of dependency as the compare group were selected. All groups peered in age, and marital status. For gathering data, “Addicts Admit Questionnaire” and laboratory device known as the "Reaction Time Assay" have been used. Results: The results of this study showed that there are significant differences among all groups in simple reaction time, choice reaction time and reaction time to auditory stimuli, but no significant difference in discrimination reaction time and reaction time to visual stimulus observed. Conclusion: The reaction time of substance-dependent groups is slower than non-dependent groups.

Nuclear energy as a 'golden bridge'? Constitutional legal problems of the negotiation of the prolongation of the running time against skimming of profits

International Nuclear Information System (INIS)

Waldhoff, Christian; Aswege, Hanka von

2010-01-01

The coalition agreement of Christian Demographic Union (CDU), Christian Social Union (CSU) and Free Democratic Party (FDP) from 26th October, 2009 characterizes the nuclear energy as a bridge technology. The coalition parties explain to prolong the running times of German nuclear power stations up to a reliable replacement by renewable energies. The conditions for the prolongation of the running times are to be regulated in agreement with energy supply companies. In the contribution under consideration, the authors report on the fiscal legal problems of the skimming of profits. Constitutional legal problems of the earmaking of a skimming of profits as well as a consensual agreement are discussed in this contribution. In the result, a financial constitutionally reliable way for the skimming of added profits due to prolongation of the running time is not evident. The legal earmaking of the duty advent for the promotion of renewable energies increases the constitutional doubts.

Reaction paths based on mean first-passage times

International Nuclear Information System (INIS)

Park, Sanghyun; Sener, Melih K.; Lu Deyu; Schulten, Klaus

2003-01-01

Finding representative reaction pathways is important for understanding the mechanism of molecular processes. We propose a new approach for constructing reaction paths based on mean first-passage times. This approach incorporates information about all possible reaction events as well as the effect of temperature. As an application of this method, we study representative pathways of excitation migration in a photosynthetic light-harvesting complex, photosystem I. The paths thus computed provide a complete, yet distilled, representation of the kinetic flow of excitation toward the reaction center, thereby succinctly characterizing the function of the system

Force, reaction time, and precision of Kung Fu strikes.

Science.gov (United States)

Neto, Osmar Pinto; Bolander, Richard; Pacheco, Marcos Tadeu Tavares; Bir, Cynthia

2009-08-01

The goal was to compare values of force, precision, and reaction time of several martial arts punches and palm strikes performed by advanced and intermediate Kung Fu practitioners, both men and women. 13 Kung Fu practitioners, 10 men and three women, participated. Only the men, three advanced and seven intermediate, were considered for comparisons between levels. Reaction time values were obtained using two high speed cameras that recorded each strike at 2500 Hz. Force of impact was measured by a load cell. For comparisons of groups, force data were normalized by participant's body mass and height. Precision of the strikes was determined by a high speed pressure sensor. The results show that palm strikes were stronger than punches. Women in the study presented, on average, lower values of reaction time and force but higher values of precision than men. Advanced participants presented higher forces than intermediate participants. Significant negative correlations between the values of force and precision and the values of force and reaction time were also found.

Verbal Processing Reaction Times in "Normal" and "Poor" Readers.

Science.gov (United States)

Culbertson, Jack; And Others

After it had been determined that reaction time (RT) was a sensitive measure of hemispheric dominance in a verbal task performed by normal adult readers, the reaction times of three groups of subjects (20 normal reading college students, 12 normal reading third graders and 11 poor reading grade school students) were compared. Ss were exposed to…

Additive effects of acetic acid upon hydrothermal reaction of amylopectin

International Nuclear Information System (INIS)

Sugano, Motoyuki; Katoh, Harumi; Komatsu, Akihiro; Kobayashi, Hiroshi; Okado, Kohta; Kakuta, Yusuke; Hirano, Katsumi

2012-01-01

It is well known that over 0.8 kg kg −1 of starch is consisted of amylopectin (AP). In this study, production of glucose for raw material of ethanol by hydrothermal reaction of AP as one of the model compound of food is discussed. Further, additive effects of acetic acid upon hydrothermal reactions of AP are also investigated. During hydrothermal reaction of AP, production of glucose occurred above 453 K, and the glucose yield increased to 0.48 kg kg −1 at 473 K. Upon hydrothermal reaction of AP at 473 K, prolongation of the holding time was not effective for the increase of the glucose yield. Upon hydrothermal reaction of AP at 473 K for 0 s, the glucose yield increased significantly by addition between 0.26 mol L −1 and 0.52 mol L −1 of acetic acid. However, the glucose yield decreased and the yield of the other constituents increased with the increases of concentration of acetic acid from 0.65 mol L −1 to 3.33 mol L −1 . It was considered that hydrolysis of AP to yield glucose was enhanced due to the increase of the amount of proton derived from acetic acid during hydrothermal reaction with 0.52 mol L −1 of acetic acid. -- Highlights: ► Glucose production by hydrothermal reaction of amylopectin (AP) at 473 K. ► Glucose yield increased to 0.48 kg kg -1 at 473 K. ► Prolongation of holding time was not effective for glucose yield. ► Glucose yield increased significantly by acetic acid (0.26–0.52 mol L-1) addition. ► Hydrolysis of AP to glucose was enhanced due to increase of proton from acetic acid.

Parental Internet Use and Lifestyle Factors as Correlates of Prolonged Screen Time of Children in Japan: Results From the Super Shokuiku School Project.

Science.gov (United States)

Yamada, Masaaki; Sekine, Michikazu; Tatsuse, Takashi

2018-03-24

Prolonged screen time (ST), which includes TV viewing and gaming on smartphones and computers, is linked to poor health. Our aim was to explore the associations between school children with prolonged ST and parental internet use (IU) and lifestyles in Japan. Children aged 6 to 13 years from the Super Shokuiku School Project, were surveyed using questionnaires in 2016. The survey assessed the grade, sex, and lifestyle of 1,659 children and parental internet use (IU) and lifestyle using Breslow's seven health behaviors. IU consisted of internet surfing and gaming on personal computers (PC), smartphones, or consoles. Three or more hours of ST was defined as prolonged ST, and its correlates were analyzed using logistic regression. Of all, 643 (38.8%) children spent ≥2 hours/day of ST on a week day, whilst 153 (9.2%) children spent ≥3 hours/day. Prolonged ST was significantly associated with children in higher grade (odds ratio [OR] 1.74; 95% confidence interval [CI], 1.20-2.51), boys (OR 2.16; 95% CI, 1.49-3.14), skipping breakfast (OR 1.88; 95% CI, 1.05-3.35), late bedtime (OR 1.80; 95% CI, 1.15-2.82), physical inactivity (OR 1.79; 95% CI, 1.12-2.87), father's IU ≥2 hours/day (OR 2.35; 95% CI, 1.52-3.63), mother's prolonged IU ≥2 hours/day (OR 2.55; 95% CI, 1.43-4.52), mothers with unhealthy behaviors (OR 1.81; 95% CI, 1.05-3.13), no rule setting governing screen time (OR 2.41; 95% CI, 1.63-3.58), and mothers with full-time employment (OR 1.95; 95% CI, 1.06-3.64). Prolonged ST among Japanese children was strongly associated with parental IU, no set rules for ST, and mother's unhealthy lifestyles. To reduce children's ST, parental engagement is warranted in the intervention strategy.

Mantra, music and reaction times: a study of its applied aspects

Directory of Open Access Journals (Sweden)

Varun Malhotra, Rinku Garg, Usha Dhar, Neera Goel, Yogesh Tripathy, Iram Jaan, Sachit Goyal, Sumit Arora

2014-11-01

Full Text Available Aims &Objectives: The mechanism of the effects of music is still under scientific study and needs to be understood in a better way. We designed this study to see how music affects reaction time and concentration. The aim of our study was to study the effect of Gayatri mantra on reaction time. Material and Methods: 30 healthy subjects were selected for the study. Baseline record of Visual online Reaction time test was taken. Online visual reaction time was measured during listening to Gayatri Mantra was taken. Results:The reaction times decreased significantly p<0.001. Conclusion: Listening to music at work area reduces distractions, helps increase concentration and delays fatigue. It can be used to heal tinnitus, as an educational tool to develop children with special needs, Alzheimers disease, to improve motor skills in Parkinsonism and help alleviate pain after surgery.

Substrate-Coated Illumination Droplet Spray Ionization: Real-Time Monitoring of Photocatalytic Reactions

Science.gov (United States)

Zhang, Hong; Li, Na; Zhao, Dandan; Jiang, Jie; You, Hong

2017-09-01

Real-time monitoring of photocatalytic reactions facilitates the elucidation of the mechanisms of the reactions. However, suitable tools for real-time monitoring are lacking. Herein, a novel method based on droplet spray ionization named substrate-coated illumination droplet spray ionization (SCI-DSI) for direct analysis of photocatalytic reaction solution is reported. SCI-DSI addresses many of the analytical limitations of electrospray ionization (ESI) for analysis of photocatalytic-reaction intermediates, and has potential for both in situ analysis and real-time monitoring of photocatalytic reactions. In SCI-DSI-mass spectrometry (MS), a photocatalytic reaction occurs by loading sample solutions onto the substrate-coated cover slip and by applying UV light above the modified slip; one corner of this slip adjacent to the inlet of a mass spectrometer is the high-electric-field location for launching a charged-droplet spray. After both testing and optimizing the performance of SCI-DSI, the value of this method for in situ analysis and real-time monitoring of photocatalytic reactions was demonstrated by the removal of cyclophosphamide (CP) in TiO2/UV. Reaction times ranged from seconds to minutes, and the proposed reaction intermediates were captured and identified by tandem mass spectrometry. Moreover, the free hydroxyl radical (·OH) was identified as the main radicals for CP removal. These results show that SCI-DSI is suitable for in situ analysis and real-time monitoring of CP removal under TiO2-based photocatalytic reactions. SCI-DSI is also a potential tool for in situ analysis and real-time assessment of the roles of radicals during CP removal under TiO2-based photocatalytic reactions. Graphical Abstract[Figure not available: see fulltext.

Reaction time for processing visual stimulus in a computer-assisted rehabilitation environment.

Science.gov (United States)

Sanchez, Yerly; Pinzon, David; Zheng, Bin

2017-10-01

To examine the reaction time when human subjects process information presented in the visual channel under both a direct vision and a virtual rehabilitation environment when walking was performed. Visual stimulus included eight math problems displayed on the peripheral vision to seven healthy human subjects in a virtual rehabilitation training (computer-assisted rehabilitation environment (CAREN)) and a direct vision environment. Subjects were required to verbally report the results of these math calculations in a short period of time. Reaction time measured by Tobii Eye tracker and calculation accuracy were recorded and compared between the direct vision and virtual rehabilitation environment. Performance outcomes measured for both groups included reaction time, reading time, answering time and the verbal answer score. A significant difference between the groups was only found for the reaction time (p = .004). Participants had more difficulty recognizing the first equation of the virtual environment. Participants reaction time was faster in the direct vision environment. This reaction time delay should be kept in mind when designing skill training scenarios in virtual environments. This was a pilot project to a series of studies assessing cognition ability of stroke patients who are undertaking a rehabilitation program with a virtual training environment. Implications for rehabilitation Eye tracking is a reliable tool that can be employed in rehabilitation virtual environments. Reaction time changes between direct vision and virtual environment.

Acute physical exercise under hypoxia improves sleep, mood and reaction time.

Science.gov (United States)

de Aquino-Lemos, Valdir; Santos, Ronaldo Vagner T; Antunes, Hanna Karen Moreira; Lira, Fabio S; Luz Bittar, Irene G; Caris, Aline V; Tufik, Sergio; de Mello, Marco Tulio

2016-02-01

This study aimed to assess the effect of two sessions of acute physical exercise at 50% VO2peak performed under hypoxia (equivalent to an altitude of 4500 m for 28 h) on sleep, mood and reaction time. Forty healthy men were randomized into 4 groups: Normoxia (NG) (n = 10); Hypoxia (HG) (n = 10); Exercise under Normoxia (ENG) (n = 10); and Exercise under Hypoxia (EHG) (n = 10). All mood and reaction time assessments were performed 40 min after awakening. Sleep was reassessed on the first day at 14 h after the initiation of hypoxia; mood and reaction time were measured 28 h later. Two sessions of acute physical exercise at 50% VO2peak were performed for 60 min on the first and second days after 3 and 27 h, respectively, after starting to hypoxia. Improved sleep efficiency, stage N3 and REM sleep and reduced wake after sleep onset were observed under hypoxia after acute physical exercise. Tension, anger, depressed mood, vigor and reaction time scores improved after exercise under hypoxia. We conclude that hypoxia impairs sleep, reaction time and mood. Acute physical exercise at 50% VO2peak under hypoxia improves sleep efficiency, reversing the aspects that had been adversely affected under hypoxia, possibly contributing to improved mood and reaction time.

Patients with prolonged effect of succinylcholine or mivacurium had novel mutations in the butyrylcholinesterase gene

DEFF Research Database (Denmark)

Wichmann, Sine; Færk, Gitte; Bundgaard, Jens R.

2016-01-01

with prolonged duration of action to succinylcholine and mivacurium. Patients were studied if they had equivocal phenotypes on the basis of BChE activity, biochemical inhibitor reactions and with pedigree if possible. Complete nucleotide sequencing was performed to describe the genotype and pedigree was used......Introduction Mutations in the butyrylcholinesterase enzyme (BChE) can result in prolonged duration of action of the neuromuscular blocking agents, succinylcholine and mivacurium, as BChE hydrolyses these drugs. Hereditary low BChE activity can cause extensively prolonged apnoea during general...... anaesthesia when these drugs are used. The aim of this study was to describe novel mutations in the butyrylcholinesterase gene (BCHE) in patients who have experienced prolonged duration of action of mivacurium or succinylcholine. Methods The Danish Cholinesterase Research Unit registers patients...

The Simplest Chronoscope V: A Theory of Dual Primary and Secondary Reaction Time Systems.

Science.gov (United States)

Montare, Alberto

2016-12-01

Extending work by Montare, visual simple reaction time, choice reaction time, discriminative reaction time, and overall reaction time scores obtained from college students by the simplest chronoscope (a falling meterstick) method were significantly faster as well as significantly less variable than scores of the same individuals from electromechanical reaction timers (machine method). Results supported the existence of dual reaction time systems: an ancient primary reaction time system theoretically activating the V5 parietal area of the dorsal visual stream that evolved to process significantly faster sensory-motor reactions to sudden stimulations arising from environmental objects in motion, and a secondary reaction time system theoretically activating the V4 temporal area of the ventral visual stream that subsequently evolved to process significantly slower sensory-perceptual-motor reactions to sudden stimulations arising from motionless colored objects. © The Author(s) 2016.

Hormone supply of the organism in prolonged emotional stress

Science.gov (United States)

Amiragova, M. G.; Stulnikov, B. V.; Svirskaya, R. I.

1980-01-01

The effect of prolonged emotional stress of varying genesis on the hormonal function of the pancreas, thyroid gland, and adrenal cortex was studied. The amount of the hormonal secretion was found to depend on the type of adaptation activity and its duration. High secretion of the hormones observed outside the adaptation activity was examined as an index of the phase transition of defense reactions to the phase of overstress.

Conformational regulation of charge recombination reactions in a photosynthetic bacterial reaction center

DEFF Research Database (Denmark)

Katona, Gergely; Snijder, Arjan; Gourdon, Pontus Emanuel

2005-01-01

In bright light the photosynthetic reaction center (RC) of Rhodobacter sphaeroides stabilizes the P(+)(870).Q(-)(A) charge-separated state and thereby minimizes the potentially harmful effects of light saturation. Using X-ray diffraction we report a conformational change that occurs within the cy...... the cytoplasmic domain of this RC in response to prolonged illumination with bright light. Our observations suggest a novel structural mechanism for the regulation of electron transfer reactions in photosynthesis....

Prolonged Shedding of Human Coronavirus in Hematopoietic Cell Transplant Recipients: Risk Factors and Viral Genome Evolution.

Science.gov (United States)

Ogimi, Chikara; Greninger, Alexander L; Waghmare, Alpana A; Kuypers, Jane M; Shean, Ryan C; Xie, Hu; Leisenring, Wendy M; Stevens-Ayers, Terry L; Jerome, Keith R; Englund, Janet A; Boeckh, Michael

2017-07-15

Recent data suggest that human coronavirus (HCoV) pneumonia is associated with significant mortality in hematopoietic cell transplant (HCT) recipients. Investigation of risk factors for prolonged shedding and intrahost genome evolution may provide critical information for development of novel therapeutics. We retrospectively reviewed HCT recipients with HCoV detected in nasal samples by polymerase chain reaction (PCR). HCoV strains were identified using strain-specific PCR. Shedding duration was defined as time between first positive and first negative sample. Logistic regression analyses were performed to evaluate factors for prolonged shedding (≥21 days). Metagenomic next-generation sequencing (mNGS) was conducted when ≥4 samples with cycle threshold values of Genome changes were consistent with the expected molecular clock of HCoV. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Effect of Nicotine on Audio and Visual Reaction Time in Dipping ...

African Journals Online (AJOL)

Nicotine through blood is harmful and as there are fewer studies in India with respect to nicotines influence on reaction time especially in the smokeless tobacco users we studied this. Reaction time is a measure of the sensorimotor integration in a person. We used a PC 1000 Hz reaction timer to record the audio and visual ...

Examining the Reaction Times of International Level Badminton Players Under 15

Directory of Open Access Journals (Sweden)

Mehmet Fatih Yüksel

2018-03-01

Full Text Available This research was conducted to examine the simple visual and auditory reaction times of badminton players of the national teams and to examine the possible effects of reaction-time average values of badminton players under the age of 15 who participated in the fifth International Rumi Child Sport Games. In total, 48 players (male = 24; female = 24 from six countries (Turkey, Azerbaijan, Bulgaria, Macedonia, Serbia, Georgia participated in the study. Stature, bodyweight, BMI, dominant and non-dominant hand visual and auditory reaction time values of the participants were detected. At the end of the study, it was determined that there were statistically significant differences between the countries in terms of male dominant and non-dominant hand visual reaction values, and male dominant hand auditory reaction values. It was also determined that there were statistically significant differences between the countries in terms of female bodyweight, BMI, dominant and non-dominant hand visual reaction values, and female non-dominant hand auditory reaction values. There was statistically significant difference between female and male players with regards to dominant and non-dominant hand visual, and non-dominant hand auditory reaction values. In conclusion, it was determined that the reaction times of the top ranking countries in the fifth International Rumi Child Sport Games under-15 were at a better level, and it can be concluded that this factor played an important role for success alongside with technique and tactic features.

Electrophysiological Correlates of Changes in Reaction Time Based on Stimulus Intensity

Science.gov (United States)

Lakhani, Bimal; Vette, Albert H.; Mansfield, Avril; Miyasike-daSilva, Veronica; McIlroy, William E.

2012-01-01

Background Although reaction time is commonly used as an indicator of central nervous system integrity, little is currently understood about the mechanisms that determine processing time. In the current study, we are interested in determining the differences in electrophysiological events associated with significant changes in reaction time that could be elicited by changes in stimulus intensity. The primary objective is to assess the effect of increasing stimulus intensity on the latency and amplitude of afferent inputs to the somatosensory cortex, and their relation to reaction time. Methods Median nerve stimulation was applied to the non-dominant hand of 12 healthy young adults at two different stimulus intensities (HIGH & LOW). Participants were asked to either press a button as fast as possible with their dominant hand or remain quiet following the stimulus. Electroencephalography was used to measure somatosensory evoked potentials (SEPs) and event related potentials (ERPs). Electromyography from the flexor digitorum superficialis of the button-pressing hand was used to assess reaction time. Response time was the time of button press. Results Reaction time and response time were significantly shorter following the HIGH intensity stimulus compared to the LOW intensity stimulus. There were no differences in SEP (N20 & P24) peak latencies and peak-to-peak amplitude for the two stimulus intensities. ERPs, locked to response time, demonstrated a significantly larger pre-movement negativity to positivity following the HIGH intensity stimulus over the Cz electrode. Discussion This work demonstrates that rapid reaction times are not attributable to the latency of afferent processing from the stimulated site to the somatosensory cortex, and those latency reductions occur further along the sensorimotor transformation pathway. Evidence from ERPs indicates that frontal planning areas such as the supplementary motor area may play a role in transforming the elevated sensory

The analysis of false prolongation of the activated partial thromboplastin time (activator: silica): Interference of C-reactive protein.

Science.gov (United States)

Liu, Jie; Li, Fanfan; Shu, Kuangyi; Chen, Tao; Wang, Xiaoou; Xie, Yaoqi; Li, Shanshan; Zhang, Zhaohua; Jin, Susu; Jiang, Minghua

2018-05-13

To investigate the effect of C-reactive protein on the activated partial thromboplastin time (APTT) (different activators) in different detecting systems. The C-reactive protein and coagulation test of 112 patients with the infectious disease were determined by automation protein analyzer IMMAG 800 and automation coagulation analyzer STA-R Evolution, respectively. The pooled plasma APTT with different concentrations of C-reactive protein was measured by different detecting system: STA-R Evolution (activator: silica, kaolin), Sysmex CS-2000i (activator: ellagic acid), and ACL TOP 700 (activator: colloidal silica). In addition, the self-made platelet lysate (phospholipid) was added to correct the APTT prolonged by C-reactive protein (150 mg/L) on STA-R Evolution (activator: silica) system. The good correlation between C-reactive protein and APTT was found on the STA-R Evolution (activator: silica) system. The APTT on the STA-R Evolution (activator: silica) system was prolonged by 24.6 second, along with increasing C-reactive protein concentration. And the APTT of plasma containing 150 mg/L C-reactive protein was shortened by 3.4-6.9 second when the plasma was mixed with self-made platelet lysate. However, the APTT was prolonged unobviously on other detecting systems including STA-R Evolution (activator: kaolin), Sysmex CS-2000i, and ACL TOP 700. C-reactive protein interferes with the detection of APTT, especially in STA-R Evolution (activator: silica) system. The increasing in C-reactive protein results in a false prolongation of the APTT (activator: silica), and it is most likely that C-reactive protein interferes the coagulable factor binding of phospholipid. © 2018 Wiley Periodicals, Inc.

Choice reaction time in patients with post-operative cognitive dysfunction

DEFF Research Database (Denmark)

Steinmetz, J.; Rasmussen, L.S.

2008-01-01

BACKGROUND: Post-operative cognitive dysfunction (POCD) is detected by administration of a neuropsychological test battery. Reaction time testing is at present not included as a standard test. Choice reaction time (CRT) data from the first International Study of Post-operative Cognitive Dysfunction...... in nine countries. CRT was measured 52 times using the four boxes test. Patients performed the test before surgery (n=1083), at 1 week (n=926) and at 3 months (n=852) post-operatively. CRT for the individual patient was determined as the median time of correct responses. The usefulness of the CRT...... had a significantly longer CRT. ROC curves revealed that a reaction time of 813 ms was the most appropriate cut-off at 1 week and 762 ms at 3 months but the positive predictive value for POCD was low: 34.4% and 14.7%, respectively. CONCLUSIONS: Post-operative cognitive dysfunction is associated...

Enhanced Bacterial α(2,6-Sialyltransferase Reaction through an Inhibition of Its Inherent Sialidase Activity by Dephosphorylation of Cytidine-5'-Monophosphate.

Directory of Open Access Journals (Sweden)

Ji-Yeon Kang

Full Text Available Bacterial α(2,6-sialyltransferases (STs from Photobacterium damsela, Photobacterium sp. JT-ISH-224, and P. leiognathi JT-SHIZ-145 were recombinantly expressed in Escherichia coli and their ST activities were compared directly using a galactosylated bi-antennary N-glycan as an acceptor substrate. In all ST reactions, there was an increase of sialylated glycans at shorter reaction times and later a decrease in prolonged reactions, which is related with the inherent sialidase activities of bacterial STs. These sialidase activities are greatly increased by free cytidine monophosphate (CMP generated from a donor substrate CMP-N-acetylneuraminic acid (CMP-Neu5Ac during the ST reactions. The decrease of sialylated glycans in prolonged ST reaction was prevented through an inhibition of sialidase activity by simple treatment of alkaline phosphatase (AP, which dephosphorylates CMP to cytidine. Through supplemental additions of AP and CMP-Neu5Ac to the reaction using the recombinant α(2,6-ST from P. leiognathi JT-SHIZ-145 (P145-ST, the content of bi-sialylated N-glycan increased up to ~98% without any decrease in prolonged reactions. This optimized P145-ST reaction was applied successfully for α(2,6-sialylation of asialofetuin, and this resulted in a large increase in the populations of multi-sialylated N-glycans compared with the reaction without addition of AP and CMP-Neu5Ac. These results suggest that the optimized reaction using the recombinant P145-ST readily expressed from E. coli has a promise for economic glycan synthesis and glyco-conjugate remodeling.

Influence of a Prolonged Tennis Match Play on Serve Biomechanics.

Directory of Open Access Journals (Sweden)

Caroline Martin

Full Text Available The aim of this study was to quantify kinematic, kinetic and performance changes that occur in the serve throughout a prolonged tennis match play. Serves of eight male advanced tennis players were recorded with a motion capture system before, at mid-match, and after a 3-hour tennis match. Before and after each match, electromyographic data of 8 upper limb muscles obtained during isometric maximal voluntary contraction were compared to determine the presence of muscular fatigue. Vertical ground reaction forces, rating of perceived exertion, ball speed, and ball impact height were measured. Kinematic and upper limb kinetic variables were computed. The results show decrease in mean power frequency values for several upper limb muscles that is an indicator of local muscular fatigue. Decreases in serve ball speed, ball impact height, maximal angular velocities and an increase in rating of perceived exertion were also observed between the beginning and the end of the match. With fatigue, the majority of the upper limb joint kinetics decreases at the end of the match. No change in timing of maximal angular velocities was observed between the beginning and the end of the match. A prolonged tennis match play may induce fatigue in upper limb muscles, which decrease performance and cause changes in serve maximal angular velocities and joint kinetics. The consistency in timing of maximal angular velocities suggests that advanced tennis players are able to maintain the temporal pattern of their serve technique, in spite of the muscular fatigue development.

Prolonged unexplained fatigue in paediatrics

NARCIS (Netherlands)

Bakker, R.J.

2010-01-01

Prolonged Unexplained Fatigue in Paediatrics. Fatigue, as the result of mental or physical exertion, will disappear after rest, drinks and food. Fatigue as a symptom of illness will recover with the recovering of the illness. But when fatigue is ongoing for a long time, and not the result of

Coexistence of Ureaplasma and chorioamnionitis is associated with prolonged mechanical ventilation.

Science.gov (United States)

Jung, Euiseok; Choi, Chang Won; Kim, Su Yeong; Sung, Tae-Jung; Kim, Haeryoung; Park, Kyoung Un; Kim, Han-Suk; Kim, Beyong Il; Choi, Jung-Hwan

2017-01-01

Both histologic chorioamnionitis (HCAM) and Ureaplasma infection are considered important contributors to perinatal lung injury. We tested the hypothesis that coexistence of maternal HCAM and perinatal Ureaplasma exposure increases the risk of prolonged mechanical ventilation in extremely low-birthweight (ELBW) infants. A retrospective cohort study was carried out of all ELBW infants born between January 2008 and December 2013 at a single academic center. Placental pathology and gastric fluid Ureaplasma data were available for all infants. Culture and polymerase chain reaction were used to detect Ureaplasma in gastric fluid. Prolonged mechanical ventilation was defined as mechanical ventilation that began within 28 days after birth and continued. Of 111 ELBW infants enrolled, 84 survived beyond 36 weeks of postmenstrual age (PMA) and were included in the analysis. Eighteen infants (21.4%) had both HCAM and Ureaplasma exposure. Seven infants (8.3%) required mechanical ventilation beyond 36 weeks of PMA. Coexistence of HCAM and Ureaplasma in gastric fluid was significantly associated with prolonged mechanical ventilation after adjustment for gestational age, sex, mode of delivery, and use of macrolide antibiotics (OR, 8.7; 95%CI: 1.1-67.2). Coexistence of maternal HCAM and perinatal Ureaplasma exposure significantly increases the risk of prolonged mechanical ventilation in ELBW infants. © 2016 Japan Pediatric Society.

Prolonged response without prolonged chemotherapy: a lesson from PCV chemotherapy in low-grade gliomas

Science.gov (United States)

Peyre, Matthieu; Cartalat-Carel, Stéphanie; Meyronet, David; Ricard, Damien; Jouvet, Anne; Pallud, Johan; Mokhtari, Karima; Guyotat, Jacques; Jouanneau, Emmanuel; Sunyach, Marie-Pierre; Frappaz, Didier; Honnorat, Jérôme; Ducray, François

2010-01-01

Previous studies with temozolomide suggest that a prolonged duration of chemotherapy is important for treating low-grade gliomas (LGGs). PCV (procarbazine, CCNU, vincristine) chemotherapy has demonstrated efficacy in treating LGGs, but this therapy cannot be used for a prolonged period because of the cumulative toxicity. The aim of the present study was to evaluate the impact of first-line PCV chemotherapy on LGGs growth kinetics. The mean tumor diameter (MTD) of 21 LGGs was measured on serial magnetic resonance images before (n=13), during, and after PCV onset (n=21). During PCV treatment, a decrease in the MTD was observed in all patients. After PCV discontinuation, an ongoing decrease in MTD was observed in 20 of the 21 patients. Median duration of the MTD decrease was 3.4 years (range, 0.8–7.7) after PCV onset and 2.7 years (range, 0–7) after the end of PCV treatment with 60% of LGGs, demonstrating an ongoing and prolonged (>2 years) response despite chemotherapy no longer being administered. According to McDonald's criteria, the rates of partial and minor responses were 5% and 38% at the end of PCV but 38% and 42% at the time of maximal MTD decrease, which occurred after a median period of 3.4 years after PCV onset. These results challenge the idea that a prolonged duration of chemotherapy is necessary for treating LGGs and raise the issue of understanding the mechanisms involved in the persistent tumor volume decrease once chemotherapy is terminated. PMID:20488959

Estimating Reaction Rate Coefficients Within a Travel-Time Modeling Framework

Energy Technology Data Exchange (ETDEWEB)

Gong, R [Georgia Institute of Technology; Lu, C [Georgia Institute of Technology; Luo, Jian [Georgia Institute of Technology; Wu, Wei-min [Stanford University; Cheng, H. [Stanford University; Criddle, Craig [Stanford University; Kitanidis, Peter K. [Stanford University; Gu, Baohua [ORNL; Watson, David B [ORNL; Jardine, Philip M [ORNL; Brooks, Scott C [ORNL

2011-03-01

A generalized, efficient, and practical approach based on the travel-time modeling framework is developed to estimate in situ reaction rate coefficients for groundwater remediation in heterogeneous aquifers. The required information for this approach can be obtained by conducting tracer tests with injection of a mixture of conservative and reactive tracers and measurements of both breakthrough curves (BTCs). The conservative BTC is used to infer the travel-time distribution from the injection point to the observation point. For advection-dominant reactive transport with well-mixed reactive species and a constant travel-time distribution, the reactive BTC is obtained by integrating the solutions to advective-reactive transport over the entire travel-time distribution, and then is used in optimization to determine the in situ reaction rate coefficients. By directly working on the conservative and reactive BTCs, this approach avoids costly aquifer characterization and improves the estimation for transport in heterogeneous aquifers which may not be sufficiently described by traditional mechanistic transport models with constant transport parameters. Simplified schemes are proposed for reactive transport with zero-, first-, nth-order, and Michaelis-Menten reactions. The proposed approach is validated by a reactive transport case in a two-dimensional synthetic heterogeneous aquifer and a field-scale bioremediation experiment conducted at Oak Ridge, Tennessee. The field application indicates that ethanol degradation for U(VI)-bioremediation is better approximated by zero-order reaction kinetics than first-order reaction kinetics.

Saline Flush After Rocuronium Bolus Reduces Onset Time and Prolongs Duration of Effect: A Randomized Clinical Trial.

Science.gov (United States)

Ishigaki, Sayaka; Masui, Kenichi; Kazama, Tomiei

2016-03-01

Circulatory factors modify the onset time of neuromuscular-blocking drugs. Therefore, we hypothesized that infusion of a saline flush immediately after rocuronium administration would shorten the onset time without influencing the duration of the rocuronium effect. Forty-eight patients were randomly allocated to the control or saline flush group. Anesthesia was induced and maintained with propofol and remifentanil, and all patients received 0.6 mg/kg rocuronium in 10 mL of normal saline. In the saline flush group, 20 mL normal saline was immediately infused after rocuronium administration. Neuromuscular blockade was assessed using acceleromyography at the adductor pollicis muscle with train-of-four (TOF) stimulation. The neuromuscular indices for rocuronium were calculated as follows: the latent onset time, defined as the time from the start of rocuronium infusion until first occurrence of depression of the first twitch of the TOF (T1) ≥5%; onset time, defined as the time from the start of rocuronium infusion until first occurrence of depression of the T1 ≥95%; clinical duration, defined as the time from the start of rocuronium administration until T1 recovered to 25% of the final T1 value; recovery index, defined as the time for recovery of T1 from 25% to 75% of the final T1 value; and the total recovery time, defined as the time from the start of rocuronium administration until reaching a TOF ratio of 0.9. Significance was designated at P rocuronium bolus by 17%, 24%, and 14%, respectively. In addition, the recovery phase was significantly prolonged in the saline flush group. The mean clinical duration (5th-95th percentile range) in the saline flush group and control group was 35 minutes (27-63 minutes) and 31 minutes (19-48 minutes; P = 0.032), respectively; the recovery index was 13 minutes (8-25 minutes) and 10 minutes (7-19 minutes; P = 0.019), respectively; and the total recovery time was 61 minutes (44-108 minutes) and 50 minutes (35-93 minutes; P = 0

A Comparative Study of Simple Auditory Reaction Time in Blind (Congenitally) and Sighted Subjects

OpenAIRE

Gandhi, Pritesh Hariprasad; Gokhale, Pradnya A.; Mehta, H. B.; Shah, C. J.

2013-01-01

Background: Reaction time is the time interval between the application of a stimulus and the appearance of appropriate voluntary response by a subject. It involves stimulus processing, decision making, and response programming. Reaction time study has been popular due to their implication in sports physiology. Reaction time has been widely studied as its practical implications may be of great consequence e.g., a slower than normal reaction time while driving can have grave results. Objective:...

A comparative study of simple auditory reaction time in blind (congenitally) and sighted subjects.

Science.gov (United States)

Gandhi, Pritesh Hariprasad; Gokhale, Pradnya A; Mehta, H B; Shah, C J

2013-07-01

Reaction time is the time interval between the application of a stimulus and the appearance of appropriate voluntary response by a subject. It involves stimulus processing, decision making, and response programming. Reaction time study has been popular due to their implication in sports physiology. Reaction time has been widely studied as its practical implications may be of great consequence e.g., a slower than normal reaction time while driving can have grave results. To study simple auditory reaction time in congenitally blind subjects and in age sex matched sighted subjects. To compare the simple auditory reaction time between congenitally blind subjects and healthy control subjects. STUDY HAD BEEN CARRIED OUT IN TWO GROUPS: The 1(st) of 50 congenitally blind subjects and 2(nd) group comprises of 50 healthy controls. It was carried out on Multiple Choice Reaction Time Apparatus, Inco Ambala Ltd. (Accuracy±0.001 s) in a sitting position at Government Medical College and Hospital, Bhavnagar and at a Blind School, PNR campus, Bhavnagar, Gujarat, India. Simple auditory reaction time response with four different type of sound (horn, bell, ring, and whistle) was recorded in both groups. According to our study, there is no significant different in reaction time between congenital blind and normal healthy persons. Blind individuals commonly utilize tactual and auditory cues for information and orientation and they reliance on touch and audition, together with more practice in using these modalities to guide behavior, is often reflected in better performance of blind relative to sighted participants in tactile or auditory discrimination tasks, but there is not any difference in reaction time between congenitally blind and sighted people.

Prolonged sitting in cars: prevalence, socio-demographic variations, and trends.

Science.gov (United States)

Sugiyama, Takemi; Merom, Dafna; van der Ploeg, Hidde P; Corpuz, Grace; Bauman, Adrian; Owen, Neville

2012-10-01

Prolonged sitting is detrimentally associated with health outcomes. However, the prevalence and characteristics of those who sit in cars for long periods are not well understood. This study examined the population prevalence, socio-demographic variations, and trends for prolonged sitting in cars among adults. Using the Sydney Greater Metropolitan Area Household Travel Survey, the prevalence of prolonged sitting time in cars (≥2 h/day) was calculated for four 3-year periods (1997-99, 2000-02, 2003-05, and 2006-08) for each population subgroup. Trends were calculated as the mean change in prevalence between adjacent survey periods. Cars were used for 66% of the total trips recorded (n=336,505). The prevalence of prolonged sitting time in cars was 16-18% in men, and 10-12% in women. Relatively higher prevalence rates were found among middle-age groups (men: 20-22%, women: 12-15%), full-time workers (men: 21-24%, women: 14-15%), those with higher income (men: 21-25%, women: 14-16%), couples with children (men: 20-21%, women: 12-14%), and those living in outer suburbs (men: 20-23%, women: 12-13%). Trends were stable in men, but increasing in women. Several subgroups (older age; living in regional suburbs) also showed increasing trends. These findings provide evidence to inform integrated approaches to measurement and policy development on prolonged car use among the public health, urban planning, and transport sectors. Copyright © 2012 Elsevier Inc. All rights reserved.

Time behaviour of the reaction front in the catalytic A + B → B + C reaction-diffusion processes

International Nuclear Information System (INIS)

Nicolini, F.G.; Rodriguez, M.A.; Wio, H.S.

1994-07-01

The problem of the time evolution of the position and width of a reaction front between initially separated reactants for the catalytic reaction A + B → B + C (C inert) is treated within a recently introduced Galanin-like scheme. (author). 6 refs

QRTEngine: An easy solution for running online reaction time experiments using Qualtrics.

Science.gov (United States)

Barnhoorn, Jonathan S; Haasnoot, Erwin; Bocanegra, Bruno R; van Steenbergen, Henk

2015-12-01

Performing online behavioral research is gaining increased popularity among researchers in psychological and cognitive science. However, the currently available methods for conducting online reaction time experiments are often complicated and typically require advanced technical skills. In this article, we introduce the Qualtrics Reaction Time Engine (QRTEngine), an open-source JavaScript engine that can be embedded in the online survey development environment Qualtrics. The QRTEngine can be used to easily develop browser-based online reaction time experiments with accurate timing within current browser capabilities, and it requires only minimal programming skills. After introducing the QRTEngine, we briefly discuss how to create and distribute a Stroop task. Next, we describe a study in which we investigated the timing accuracy of the engine under different processor loads using external chronometry. Finally, we show that the QRTEngine can be used to reproduce classic behavioral effects in three reaction time paradigms: a Stroop task, an attentional blink task, and a masked-priming task. These findings demonstrate that QRTEngine can be used as a tool for conducting online behavioral research even when this requires accurate stimulus presentation times.

Characteristics of scrub typhus, murine typhus, and Q fever among elderly patients: Prolonged prothrombin time as a predictor for severity.

Science.gov (United States)

Chang, Ko; Lee, Nan-Yao; Ko, Wen-Chien; Lin, Wei-Ru; Chen, Yen-Hsu; Tsai, Jih-Jin; Chen, Tun-Chieh; Lin, Chun-Yu; Chang, Ya-Ting; Lu, Po-Liang

2017-06-22

The clinical manifestations of scrub typhus, murine typhus and acute Q fever in the elderly are not clear. We conducted a retrospective study to identify the characteristics of the elderly aged ≥65 years with a comparison group aged 18-64 years among patients with scrub typhus, murine typhus, or acute Q fever who were serologically confirmed at three hospitals in Taiwan during 2002-2011. Among 441 cases, including 187 cases of scrub typhus, 166 acute Q fever, and 88 murine typhus, 68 (15.4%) cases were elderly patients. The elderly had a higher severe complication rate (10.3% vs. 3.5%, p = 0.022), but did not have a significantly higher mortality rate (1.47% vs. 0.54%, p = 0.396). Compared with those without severe complications, we found the elderly (p = 0.022), dyspnea (p = 0.006), less relative bradycardia (p = 0.004), less febrile illness (p = 0.004), prolonged prothrombin time (PT) (p = 0.002), higher levels of initial C-reactive protein (p = 0.039), blood leukocyte counts (p = 0.01), and lower platelet counts (p = 0.012) are significantly associated with severe complications. Only prolonged prothrombin time was associated with severe complications in multivariate analysis (p = 0.018, CI 95% 0.01-0.66). Among clinical symptoms and laboratory data, multivariate analysis revealed chills was less frequently occurred in the elderly (p = 0.012, 95% confidence interval [CI]: 1.33-9.99). The elderly cases with scrub typhus, murine typhus, or acute Q fever would be more likely to have severe complications, for which prothrombin time prolongation is an important predictor for severe complications. Copyright © 2017. Published by Elsevier B.V.

Analysis of Relationship between Levofloxacin and Corrected QT Prolongation Using a Clinical Data Warehouse.

Science.gov (United States)

Park, Man Young; Kim, Eun Yeob; Lee, Young Ho; Kim, Woojae; Kim, Ku Sang; Sheen, Seung Soo; Lim, Hong Seok; Park, Rae Woong

2011-03-01

The aim of this study was to examine whether or not levofloxacin has any relationship with QT prolongation in a real clinical setting by analyzing a clinical data warehouse of data collected from different hospital information systems. Electronic prescription data and medical charts from 3 different hospitals spanning the past 9 years were reviewed, and a clinical data warehouse was constructed. Patients who were both administrated levofloxacin and given electrocardiograms (ECG) were selected. The correlations between various patient characteristics, concomitant drugs, corrected QT (QTc) prolongation, and the interval difference in QTc before and after levofloxacin administration were analyzed. A total of 2,176 patients from 3 different hospitals were included in the study. QTc prolongation was found in 364 patients (16.7%). The study revealed that age (OR 1.026, p data seem to be essential to adverse drug reaction surveillance in future.

The time dependence of rate constants of esub(aq)sup(-) reactions

International Nuclear Information System (INIS)

Burcl, R.; Byakov, V.M.; Grafutin, V.I.

1982-01-01

Published data about the time dependence of rate constants k(esub(aq)sup(-)+Ac) of esub(aq)sup(-) reactions with the acceptor Ac are analyzed, using the results of rate constant k(Ps+Ac) measurements for positronium reactions. It is shown that neither esub(aq)sup(-) nor Ps reaction rate constants depend on time in the observable range. Experimentally found concentration dependence of k(esub(aq)sup(-)+Ac) is due to other factors, connected with the existence of electric charge of esub(aq)sup(-), e.g. ionic strength, tunnelling effect etc. (author)

Correlating defect density with growth time in continuous graphene films.

Science.gov (United States)

Kang, Cheong; Jung, Da Hee; Nam, Ji Eun; Lee, Jin Seok

2014-12-01

We report that graphene flakes and films which were synthesized by copper-catalyzed atmospheric pressure chemical vapor deposition (APCVD) method using a mixture of Ar, H2, and CH4 gases. It was found that variations in the reaction parameters, such as reaction temperature, annealing time, and growth time, influenced the domain size of as-grown graphene. Besides, the reaction parameters influenced the number of layers, degree of defects and uniformity of the graphene films. The increase in growth temperature and annealing time tends to accelerate the graphene growth rate and increase the diffusion length, respectively, thereby increasing the average size of graphene domains. In addition, we confirmed that the number of pinholes reduced with increase in the growth time. Micro-Raman analysis of the as-grown graphene films confirmed that the continuous graphene monolayer film with low defects and high uniformity could be obtained with prolonged reaction time, under the appropriate annealing time and growth temperature.

Time-reversal asymmetry: polarization and analyzing power in nuclear reactions

International Nuclear Information System (INIS)

Rioux, C.; Roy, R.; Slobodrian, R.J.; Conzett, H.E.

1984-01-01

Measurements of the proton polarization in the reactions 7 Li( 3 He, p vector) 9 Be and 9 Be( 3 He, p vector) 11 B and of the analyzing powers in the inverse reactions, initiated by polarized protons at the same center-of-mass energies, show significant differences. This implies the failure of the polarization-analyzing-power theorem and, prima facie, of time-reversal invariance in these reactions. The reaction 2 H( 3 He, p vector) 4 He and its inverse have also been investigated and show smaller differences. A discussion of instrumental asymmetries is presented

Time asymmetry: Polarization and analyzing power in the nuclear reactions

International Nuclear Information System (INIS)

Rioux, C.; Roy, R.; Slobodrian, R.J.; Conzett, H.E.

1983-01-01

Measurements of the proton polarization in the reactions 7 Li( 3 He, p vector) 9 Be and 9 Be( 3 He, p vector) 11 B and of the analyzing powers of the inverse reactions, initiated by polarized protons at the same c.m. energies, show significant differences which imply the failure of the polarization-analyzing-power theorem and, prima facie, of time-reversal invariance in these reactions. The reaction 2 H( 3 He, p vector) 4 He and its inverse have also been investigated and show some smaller differences. A discussion of the instrumental asymmetries is presented. (orig.)

Investigation of the speed of reaction on external stimulus in schizophrenic psychosis.

Science.gov (United States)

Zampera, E

1997-06-01

In 30 schizophrenic examinees, the latention time was measured. This time is referred to as an interval between the start of the stimulus and the response to the stimulus in the skin-galvanic reflex. Elementary stimulation has been applied, using device's timer tone and clapping of hands, which should simulate and associate the thunderclap. The intensity of psychosis was measured according to the Metric scale of psychotic behavior by Rogina, while the intensity of anxiety was measured by psychological tests: Rorschach's psycho-diagnostic test and Spillberger's questionnaire for anxiety. The reaction to the stimulus and latention time were registered using polygraph unit in order to record skin-galvanic reflex. The research was performed at two separate time points: prior to the therapy with derivatives of the phenothiazine group (the experimental examination group), and 25 days after the therapy (control group). The research has shown that the latention time in schizophrenic examinees does not significantly differ from the corresponding time in healthy controls, and it averages 2.30 seconds. Furthermore, no statistically significant difference in latention time before and after the therapy was observed. However, before the therapy started, i.e. in experimental group," the examinees who were psychotic to a greater extent have shown longer latention than those less psychotic. Additional finding was that the examinees from experimental group who were more anxious according to psychological tests have also shown longer latention time. After the therapy, the reaction to the external stimulus was stronger, which was expressed in increased reaction amplitude in skin-galvanic reflex. The latention time was prolonged, especially in case of examinees that were psychotic to a smaller extent before the therapy. We can conclude that so-called transformed psychotic anxiety was replaced after the therapy with a "new" anxiety-existential fear, i.e. the stronger anxious expectation

Single-molecule stochastic times in a reversible bimolecular reaction

Science.gov (United States)

Keller, Peter; Valleriani, Angelo

2012-08-01

In this work, we consider the reversible reaction between reactants of species A and B to form the product C. We consider this reaction as a prototype of many pseudobiomolecular reactions in biology, such as for instance molecular motors. We derive the exact probability density for the stochastic waiting time that a molecule of species A needs until the reaction with a molecule of species B takes place. We perform this computation taking fully into account the stochastic fluctuations in the number of molecules of species B. We show that at low numbers of participating molecules, the exact probability density differs from the exponential density derived by assuming the law of mass action. Finally, we discuss the condition of detailed balance in the exact stochastic and in the approximate treatment.

Auditory and visual reaction time and peripheral field of vision in helmet users

Directory of Open Access Journals (Sweden)

Abbupillai Adhilakshmi

2016-12-01

Full Text Available Background: The incidence of fatal accidents are more in two wheeler drivers compared to four wheeler drivers. Head injury is of serious concern when recovery and prognosis of the patients are warranted, helmets are being used for safety purposes by moped, scooters and motorcycle drivers. Although, helmets are designed with cushioning effect to prevent head injuries but there are evidences of increase risk of neck injuries and reduced peripheral vision and hearing in helmet users. A complete full coverage helmets provide about less than 3 percent restrictions in horizontal peripheral visual field compared to rider without helmet. The standard company patented ergonomically designed helmets which does not affect the peripheral vision neither auditory reaction time. Objective: This pilot study aimed to evaluate the peripheral field of vision and auditory and visual reaction time in a hypertensive, diabetic and healthy male and female in order to have a better insight of protective characteristics of helmet in health and disease. Method: This pilot study carried out on age matched male of one healthy, one hypertensive and one diabetic and female subject of one healthy, one hypertensive and one diabetics. The field of vision was assessed by Lister’s perimeter whereas auditory and visual reaction time was recorded with response analyser. Result : Gender difference was not noted in peripheral field of vision but mild difference was found in auditory reaction time for high frequency and visual reaction time for both red and green colour in healthy control. But lateral and downward peripheral visual field was found reduced whereas auditory and visual reaction time was found increased in both hypertensive and diabetic subject in both sexes. Conclusion: Peripheral vision, auditory reaction time and visual reaction time in hypertensive and diabetics may lead to vulnerable accident. Helmet use has proven to reduce extent of injury in motorcyclist and

Multifragment emission times in Xe induced reactions

Energy Technology Data Exchange (ETDEWEB)

Moroni, A. [INFN and Dipartimento di Fisica, Via Celoria 16, 20133 Milano (Italy); Bowman, D.R. [AECL Research, Chalk River Laboratories, Chalk River, Ont. (Canada); Bruno, M. [Dipartimento di Fisica and INFN, Via Irnerio 46, 40126 Bologna (Italy); Buttazzo, P. [Dipartimento di Fisica and INFN, Via A. Valerio 2, 34127 Trieste (Italy); Celano, L. [INFN, Via Amendola 173, 70126 Bari (Italy); Colonna, N. [INFN, Via Amendola 173, 70126 Bari (Italy); D`Agostino, M. [Dipartimento di Fisica and INFN, Via Irnerio 46, 40126 Bologna (Italy); Dinius, J.D. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Ferrero, A. [INFN and Dipartimento di Fisica, Via Celoria 16, 20133 Milano (Italy); Fiandri, M.L. [Dipartimento di Fisica and INFN, Via Irnerio 46, 40126 Bologna (Italy); Gelbke, K. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Glasmacher, T. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Gramegna, F. [INFN Laboratori Nazionali di Legnaro, Via Romea 4, 35020 Legnaro (Italy); Handzy, D.O. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Horn, D. [AECL Research, Chalk River Laboratories, Chalk River, Ont. (Canada); Hsi Wenchien [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Huang, M. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Iori, I. [INFN and Dipartimento di Fisica, Via Celoria 16, 20133 Milano (Italy); Lisa, M. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Lynch, W.G. [NSCL, Michigan State University, E. Lansing, 48824 MI (United States); Margagliotti, G.V. [Dipartimento di Fisica and INFN, Via A. Valerio 2, 34127 Trieste (Italy); Mastinu, P.F. [Dipartimento di Fisica and INFN, Via Irnerio 46, 40126 Bologna (Italy); Milazzo, P.M. [Dipartimento di Fisica and INFN, Via Irnerio 46, 40126 Bologna (Italy); Montoya, C.

1995-02-06

Multifragment emission is studied in {sup 129}Xe+{sup nat}Cu reactions. The emission process for central collisions occurs on a time scale of similar 200fm/c at 30MeV/n. Intermediate-mass-fragment yields, velocity correlation functions and emission velocities of Z=6 fragments are compared with predictions of statistical decay models. ((orig.)).

Analysis of NPP pipes and equipment damage in life time prolongation

International Nuclear Information System (INIS)

Tkachev, V.V.; Zheltukhin, K.K.

2008-01-01

Paper describes a procedure to calculate the probability of pipes and equipment failure taking account of both the service records of the structures under various conditions and their aging. The parameters characterizing applied loads, failures, as well as metal strength, mechanical and thermal properties serve as the arbitrary values used in the described procedure. Paper presents an example of the probability calculation of failure of the RBMK emergency feed pump recirculation pipes when their service life is prolonged [ru

The drug efficacy and adverse reactions in a mouse model of oral squamous cell carcinoma treated with oxaliplatin at different time points during a day

Directory of Open Access Journals (Sweden)

Yang K

2013-06-01

Full Text Available Kai Yang,1,2 Ningbo Zhao,1 Dan Zhao,1,2 Dan Chen,1 Yadong Li1 1Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 2Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, People’s Republic of China Background: Recent studies have shown that the growth and proliferation of cancer cells in vivo exhibit circadian rhythm, and the efficacy and adverse reactions of platinum-based anticancer drugs administered at different times of the day vary significantly on colon cancer. However, since the circadian rhythms of growth and proliferation of various cancer cells often differ, the question of whether the administration of platinum anticancer drugs at different times of the day exerts significantly different efficacy and adverse effects on oral cancers remains to be elucidated. This study has compared the efficacy and adverse effects of oxaliplatin (L-OHP administration at different times during a day on oral squamous cell carcinoma in mice and has analyzed cellular circadian rhythms. Methods: The mouse model for oral squamous cell carcinoma was established in 75 nude mice, housed in a 12 hour light/12 hour dark cycle environment. The mice were randomly divided into five groups; four experimental groups were intravenously injected with L-OHP at four time points within a 24-hour period (4, 10, 16, and 22 hours after lights on [HALO]. The control group was intravenously injected with the same volume of saline. Treatment efficacy and adverse reactions were compared on the seventh day after the injection, at 22 HALO. The existence of circadian rhythms was determined by cosine analysis. Results: Only injections of L-OHP at 16 and 22 HALO significantly prolonged animal survival time. The adverse reactions in mice injected with L-OHP at 16 and 22 HALO were significantly less than those observed in mice administered L-OHP at 4 and 10 HALO

Prolongation of rat islet allograft survival by direct ultraviolet irradiation of the graft

International Nuclear Information System (INIS)

Lau, H.; Reemtsma, K.; Hardy, M.A.

1984-01-01

Ultraviolet irradiation of rat dendritic cells completely abrogated their allostimulatory capacity in a mixed lymphocyte reaction. Rat islets of Langerhans similarly irradiated remained hormonally functional when transplanted into syngeneic diabetic rats. Allogeneic transplantation across a major histocompatibility barrier of islets initially treated in vitro with ultraviolet irradiation resulted in prolonged allograft survival without the use of any immunosuppressive agents

Delta-electron spectroscopy: An aid for the determination of reaction times in heavy ion reactions

International Nuclear Information System (INIS)

Skapa, H.

1983-01-01

For the systems I->Au and I->Bi at an incident energy of 6.2 MeV/u (I->Au) and 6.6 MeV/u (I->Bi) the emission probability of delta electrons was determined. In an energy range from 150 KeV to 1000 KeV electrons were spectroscoped in coincidence to elastically, quasielastically, and deep inelastically scattered ions. In deep inelastic reaction between reaction products with high and without a mean mass drift was discriminated. The contribution of the conversion electrons, determined from gamma spectra, extends in the range of deep inelastic reactions of about 60%. While the ratio of conversion electrons for deep inelastic events with large to such without mass drift shows a flat, monotoneous growth for the ratio of the measured emission probabilities a oscillation-like structure with about 400 KeV width results. An interpretation of this structure as interference effect by nuclear time delay yields for the case of large mass drift a nuclear retention time of 7.5 x 10 -21 s. (orig./HSI) [de

Vision and Vestibular System Dysfunction Predicts Prolonged Concussion Recovery in Children.

Science.gov (United States)

Master, Christina L; Master, Stephen R; Wiebe, Douglas J; Storey, Eileen P; Lockyer, Julia E; Podolak, Olivia E; Grady, Matthew F

2018-03-01

Up to one-third of children with concussion have prolonged symptoms lasting beyond 4 weeks. Vision and vestibular dysfunction is common after concussion. It is unknown whether such dysfunction predicts prolonged recovery. We sought to determine which vision or vestibular problems predict prolonged recovery in children. A retrospective cohort of pediatric patients with concussion. A subspecialty pediatric concussion program. Four hundred thirty-two patient records were abstracted. Presence of vision or vestibular dysfunction upon presentation to the subspecialty concussion program. The main outcome of interest was time to clinical recovery, defined by discharge from clinical follow-up, including resolution of acute symptoms, resumption of normal physical and cognitive activity, and normalization of physical examination findings to functional levels. Study subjects were 5 to 18 years (median = 14). A total of 378 of 432 subjects (88%) presented with vision or vestibular problems. A history of motion sickness was associated with vestibular dysfunction. Younger age, public insurance, and presence of headache were associated with later presentation for subspecialty concussion care. Vision and vestibular problems were associated within distinct clusters. Provocable symptoms with vestibulo-ocular reflex (VOR) and smooth pursuits and abnormal balance and accommodative amplitude (AA) predicted prolonged recovery time. Vision and vestibular problems predict prolonged concussion recovery in children. A history of motion sickness may be an important premorbid factor. Public insurance status may represent problems with disparities in access to concussion care. Vision assessments in concussion must include smooth pursuits, saccades, near point of convergence (NPC), and accommodative amplitude (AA). A comprehensive, multidomain assessment is essential to predict prolonged recovery time and enable active intervention with specific school accommodations and targeted rehabilitation.

Time asymmetry: Polarization and analyzing power in the nuclear reactions

Energy Technology Data Exchange (ETDEWEB)

Rioux, C.; Roy, R.; Slobodrian, R.J. (Laval Univ., Quebec City (Canada). Lab. de Physique Nucleaire); Conzett, H.E. (California Univ., Berkeley (USA). Lawrence Berkeley Lab.)

1983-02-28

Measurements of the proton polarization in the reactions /sup 7/Li(/sup 3/He, p vector)/sup 9/Be and /sup 9/Be(/sup 3/He, p vector)/sup 11/B and of the analyzing powers of the inverse reactions, initiated by polarized protons at the same c.m. energies, show significant differences which imply the failure of the polarization-analyzing-power theorem and, prima facie, of time-reversal invariance in these reactions. The reaction /sup 2/H(/sup 3/He, p vector)/sup 4/ He and its inverse have also been investigated and show some smaller differences. A discussion of the instrumental asymmetries is presented.

Neutron Scattering in Hydrogenous Moderators, Studied by Time Dependent Reaction Rate Method

Energy Technology Data Exchange (ETDEWEB)

Larsson, L G; Moeller, E; Purohit, S N

1966-03-15

The moderation and absorption of a neutron burst in water, poisoned with the non-1/v absorbers cadmium and gadolinium, has been followed on the time scale by multigroup calculations, using scattering kernels for the proton gas and the Nelkin model. The time dependent reaction rate curves for each absorber display clear differences for the two models, and the separation between the curves does not depend much on the absorber concentration. An experimental method for the measurement of infinite medium reaction rate curves in a limited geometry has been investigated. This method makes the measurement of the time dependent reaction rate generally useful for thermalization studies in a small geometry of a liquid hydrogenous moderator, provided that the experiment is coupled to programs for the calculation of scattering kernels and time dependent neutron spectra. Good agreement has been found between the reaction rate curve, measured with cadmium in water, and a calculated curve, where the Haywood kernel has been used.

Effect of dual task activity on reaction time in males and females.

Science.gov (United States)

Kaur, Manjinder; Nagpal, Sangeeta; Singh, Harpreet; Suhalka, M L

2014-01-01

The present study was designed to compare the auditory and visual reaction time on an Audiovisual Reaction Time Machine with the concomitant use of mobile phones in 52 women and 30 men in the age group of 18-40 years. Males showed significantly (p multitasking, in hand held (24.38% & 18.70% respectively) and hands free modes (36.40% & 18.40% respectively) of the use of cell phone. VRT increased non significantly during multitasking in both the groups. However, the multitasking per se has detrimental effect on the reaction times in both the groups studied. Hence, it should best be avoided in crucial and high attention demanding tasks like driving.

Caffeine Reduces Reaction Time and Improves Performance in Simulated-Contest of Taekwondo

Science.gov (United States)

Santos, Victor G. F.; Santos, Vander R. F.; Felippe, Leandro J. C.; Almeida, Jose W.; Bertuzzi, Rômulo; Kiss, Maria A. P. D. M.; Lima-Silva, Adriano E.

2014-01-01

The aim of this study was to investigate the effects of caffeine on reaction time during a specific taekwondo task and athletic performance during a simulated taekwondo contest. Ten taekwondo athletes ingested either 5 mg·kg−1 body mass caffeine or placebo and performed two combats (spaced apart by 20 min). The reaction-time test (five kicks “Bandal Tchagui”) was performed immediately prior to the first combat and immediately after the first and second combats. Caffeine improved reaction time (from 0.42 ± 0.05 to 0.37 ± 0.07 s) only prior to the first combat (P = 0.004). During the first combat, break times during the first two rounds were shorter in caffeine ingestion, followed by higher plasma lactate concentrations compared with placebo (P = 0.029 and 0.014, respectively). During the second combat, skipping-time was reduced, and relative attack times and attack/skipping ratio was increased following ingestion of caffeine during the first two rounds (all P Caffeine resulted in no change in combat intensity parameters between the first and second combat (all P > 0.05), but combat intensity was decreased following placebo (all P caffeine reduced reaction time in non-fatigued conditions and delayed fatigue during successive taekwondo combats. PMID:24518826

Investigating the combined effects of heat and lighting on students reaction time in laboratory condition

Directory of Open Access Journals (Sweden)

Zohre Mohebian

2016-12-01

Full Text Available Introduction: In many workplaces there is exposure to heat and light simultaneously. This study investigated the combined effect of heat and lighting on some cognitive performance, i.e. reaction time. Methodology: the present semi-experimental study was conducted 2015 on 33 healthy students (16 girls and 17 boys with a mean age of 22.1 in the thermal stress chamber. The reaction time parameter by the reaction time measurement device, after exposure to different heat surfaces (dry temperatures 22 °C and 37 °C and lighting surfaces (200, 500 and 1500 lux. Data were analyzed using ANOVA test in SPSS-20. Results: The results showed that the average simple, diagnostic, two-color selective, two-sound selective reaction times and reaction time error increased after combined exposure to heat and lighting and showed a significant difference (P<0.05. The maximum score of reaction time belong to temperature of 37 c° and lighting of 1500 lux, the minimum score of reaction time belong to temperature of 22 °c and lighting of 1500 lux.

Overwork accelerates thrombotic reaction: implications for the pathogenesis of Karoshi.

Science.gov (United States)

Otsui, Kazunori; Yamamoto, Junichiro; Inoue, Nobutaka

2018-02-01

Work-related stressors are potential causes of cardiovascular diseases (CVDs) and stroke; however, the pathophysiological mechanisms by which occupational stress induces and exacerbates CVDs remain unclear. The global thrombosis test (GTT) is a novel in vitro assay for evaluating both thrombotic reactions and subsequent thrombolysis. The time required to form an occlusive thrombus with the GTT, called as the occlusion time (OT), and the time to lyse the thrombus, the lysis time (LT), are markers of thrombotic and thrombolytic reactions, respectively. We investigated the impact of work-related stress on the thrombotic and thrombolytic reactions in 46 healthy medical residents. Off-duty or on-duty blood samples were collected on the mornings of non-work days or after the night duty on the emergent room respectively. The duration of sleep was significantly shorter during night duty than during off-duty nights [2.25 (1.0, 3.0) h vs. 6.0 (5.0, 7.0) h; p < 0.001]. Baseline OT was 310.3 (260.9, 437.7) s. whereas the on-duty OT was significantly shortened [284.2 (230.5, 355.8) s; p < 0.01]. LT was significantly prolonged during overwork conditions compared with off-duty conditions [1547 (1346, 1908) s vs. 1470 (1219, 1692) s; p < 0.05]. Overwork accelerates the thrombotic reactions. These reactions might explain the pathogenesis of overwork-related CVDs. The GTT is a good tool for evaluating of the level of fatigue.

Poststimulation time interval-dependent effects of motor cortex anodal tDCS on reaction-time task performance.

Science.gov (United States)

Molero-Chamizo, Andrés; Alameda Bailén, José R; Garrido Béjar, Tamara; García López, Macarena; Jaén Rodríguez, Inmaculada; Gutiérrez Lérida, Carolina; Pérez Panal, Silvia; González Ángel, Gloria; Lemus Corchero, Laura; Ruiz Vega, María J; Nitsche, Michael A; Rivera-Urbina, Guadalupe N

2018-02-01

Anodal transcranial direct current stimulation (tDCS) induces long-term potentiation-like plasticity, which is associated with long-lasting effects on different cognitive, emotional, and motor performances. Specifically, tDCS applied over the motor cortex is considered to improve reaction time in simple and complex tasks. The timing of tDCS relative to task performance could determine the efficacy of tDCS to modulate performance. The aim of this study was to compare the effects of a single session of anodal tDCS (1.5 mA, for 15 min) applied over the left primary motor cortex (M1) versus sham stimulation on performance of a go/no-go simple reaction-time task carried out at three different time points after tDCS-namely, 0, 30, or 60 min after stimulation. Performance zero min after anodal tDCS was improved during the whole course of the task. Performance 30 min after anodal tDCS was improved only in the last block of the reaction-time task. Performance 60 min after anodal tDCS was not significantly different throughout the entire task. These findings suggest that the motor cortex excitability changes induced by tDCS can improve motor responses, and these effects critically depend on the time interval between stimulation and task performance.

Prolonged warm ischemia time is associated with graft failure and mortality after kidney transplantation.

Science.gov (United States)

Tennankore, Karthik K; Kim, S Joseph; Alwayn, Ian P J; Kiberd, Bryce A

2016-03-01

Warm ischemia time is a potentially modifiable insult to transplanted kidneys, but little is known about its effect on long-term outcomes. Here we conducted a study of United States kidney transplant recipients (years 2000-2013) to determine the association between warm ischemia time (the time from organ removal from cold storage to reperfusion with warm blood) and death/graft failure. Times under 10 minutes were potentially attributed to coding error. Therefore, the 10-to-under-20-minute interval was chosen as the reference group. The primary outcome was mortality and graft failure (return to chronic dialysis or preemptive retransplantation) adjusted for recipient, donor, immunologic, and surgical factors. The study included 131,677 patients with 35,901 events. Relative to the reference patients, times of 10 to under 20, 20 to under 30, 30 to under 40, 40 to under 50, 50 to under 60, and 60 and more minutes were associated with hazard ratios of 1.07 (95% confidence interval, 0.99-1.15), 1.13 (1.06-1.22), 1.17 (1.09-1.26), 1.20 (1.12-1.30), and 1.23 (1.15-1.33) for the composite event, respectively. Association between prolonged warm ischemia time and death/graft failure persisted after stratification by donor type (living vs. deceased donor) and delayed graft function status. Thus, warm ischemia time is associated with adverse long-term patient and graft survival after kidney transplantation. Identifying strategies to reduce warm ischemia time is an important consideration for future study. Copyright © 2015 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Continuous performance task in ADHD: Is reaction time variability a key measure?

Science.gov (United States)

Levy, Florence; Pipingas, Andrew; Harris, Elizabeth V; Farrow, Maree; Silberstein, Richard B

2018-01-01

To compare the use of the Continuous Performance Task (CPT) reaction time variability (intraindividual variability or standard deviation of reaction time), as a measure of vigilance in attention-deficit hyperactivity disorder (ADHD), and stimulant medication response, utilizing a simple CPT X-task vs an A-X-task. Comparative analyses of two separate X-task vs A-X-task data sets, and subgroup analyses of performance on and off medication were conducted. The CPT X-task reaction time variability had a direct relationship to ADHD clinician severity ratings, unlike the CPT A-X-task. Variability in X-task performance was reduced by medication compared with the children's unmedicated performance, but this effect did not reach significance. When the coefficient of variation was applied, severity measures and medication response were significant for the X-task, but not for the A-X-task. The CPT-X-task is a useful clinical screening test for ADHD and medication response. In particular, reaction time variability is related to default mode interference. The A-X-task is less useful in this regard.

Time-dependent--S-matrix Hartree-Fock theory of complex reactions

International Nuclear Information System (INIS)

Griffin, J.J.; Lichtner, P.C.; Dworzecka, M.

1980-01-01

Some limitations of the conventional time-dependent Hartree-Fock method for describing complex reactions are noted, and one particular ubiquitous defect is discussed in detail: the post-breakup spurious cross channel correlations which arise whenever several asymptotic reaction channels must be simultaneously described by a single determinant. A reformulated time-dependent--S-matrix Hartree-Fock theory is proposed, which obviates this difficulty. Axiomatic requirements minimal to assure that the time-dependent--S-matrix Hartree-Fock theory represents an unambiguous and physically interpretable asymptotic reaction theory are utilized to prescribe conditions upon the definition of acceptable asymptotic channels. That definition, in turn, defines the physical range of the time-dependent--S-matrix Hartree-Fock theory to encompass the collisions of mathematically well-defined ''time-dependent Hartree-Fock droplets.'' The physical properties of these objects then circumscribe the content of the Hartree-Fock single determinantal description. If their periodic vibrations occur for continuous ranges of energy then the resulting ''classical'' time-dependent Hartree-Fock droplets are seen to be intrinsically dissipative, and the single determinantal description of their collisions reduces to a ''trajectory'' theory which can describe the masses and relative motions of the fragments but can provide no information about specific asymptotic excited states beyond their constants of motion, or the average properties of the limit, if it exists, of their equilibrization process. If, on the other hand, the periodic vibrations of the time-dependent Hartree-Fock droplets are discrete in energy, then the time-dependent--S-matrix Hartree-Fock theory can describe asymptotically the time-average properties of the whole spectrum of such periodic vibrations

QT Interval Prolongation Associated with Intramuscular Ziprasidone in Chinese Patients: A Case Report and a Comprehensive Literature Review with Meta-Analysis

Directory of Open Access Journals (Sweden)

Xian-Bin Li

2014-01-01

Full Text Available Intramuscular (IM ziprasidone has been associated with QTc interval prolongations in patients with preexisting risk factors. A 23-year-old male Chinese schizophrenia patient experienced an increase of QTc interval of 83 milliseconds (ms after receiving 20 mg IM ziprasidone (baseline and increased QT/QTc were, respectively, 384/418 and 450/501. This was rated as a probable adverse drug reaction (ADR by the Liverpool ADR causality assessment tool. A systematic review including all types of trials reporting the effect of IM ziprasidone on the QTc interval prolongation identified 19 trials with a total of 1428 patients. Mean QTc change from baseline to end of each study was −3.7 to 12.8 ms after IM ziprasidone. Four randomized trials (3 of 4 published in Chinese were used to calculate a meta-analysis of QTc interval prolongation which showed no significant differences between IM ziprasidone and IM haloperidol groups (risk ratio 0.49 to 4.31, 95% confidence interval 0.09 to 19.68, P = 0.06 to 0.41. However, our review included two cases of patients who experienced symptoms probably related to QTc prolongation after IM ziprasidone. Thus, careful screening and close monitoring, including baseline ECG, should be considered in patients receiving IM ziprasidone for the first time.

Simulation of biochemical reactions with time-dependent rates by the rejection-based algorithm

Energy Technology Data Exchange (ETDEWEB)

Thanh, Vo Hong, E-mail: vo@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Priami, Corrado, E-mail: priami@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Department of Mathematics, University of Trento, Trento (Italy)

2015-08-07

We address the problem of simulating biochemical reaction networks with time-dependent rates and propose a new algorithm based on our rejection-based stochastic simulation algorithm (RSSA) [Thanh et al., J. Chem. Phys. 141(13), 134116 (2014)]. The computation for selecting next reaction firings by our time-dependent RSSA (tRSSA) is computationally efficient. Furthermore, the generated trajectory is exact by exploiting the rejection-based mechanism. We benchmark tRSSA on different biological systems with varying forms of reaction rates to demonstrate its applicability and efficiency. We reveal that for nontrivial cases, the selection of reaction firings in existing algorithms introduces approximations because the integration of reaction rates is very computationally demanding and simplifying assumptions are introduced. The selection of the next reaction firing by our approach is easier while preserving the exactness.

Effect of Colour of Object on Simple Visual Reaction Time in Normal Subjects

Directory of Open Access Journals (Sweden)

Sunita B. Kalyanshetti

2014-01-01

Full Text Available The measure of simple reaction time has been used to evaluate the processing speed of CNS and the co-ordination between the sensory and motor systems. As the reaction time is influenced by different factors; the impact of colour of objects in modulating the reaction time has been investigated in this study. 200 healthy volunteers (female gender 100 and male gender100 of age group 18-25 yrs were included as subjects. The subjects were presented with two visual stimuli viz; red and green light by using an electronic response analyzer. Paired‘t’ test for comparison of visual reaction time for red and green colour in male gender shows p value<0.05 whereas in female gender shows p<0.001. It was observed that response latency for red colour was lesser than that of green colour which can be explained on the basis of trichromatic theory.

Using the rate of bacterial clearance determined by real-time polymerase chain reaction as a timely surrogate marker to evaluate the appropriateness of antibiotic usage in critical patients with Acinetobacter baumannii bacteremia.

Science.gov (United States)

Chuang, Yu-Chung; Chang, Shan-Chwen; Wang, Wei-Kung

2012-08-01

Bacteremia caused by Acinetobacter baumannii is becoming more frequent among critically ill patients, and has been associated with high mortality and prolonged hospital stay. Multidrug resistance and delay in blood culture have been shown to be significant barriers to appropriate antibiotic treatment. Quantitative polymerase chain reaction assays were recently used to monitor bacterial loads; we hypothesized that the rate of bacterial clearance determined by quantitative polymerase chain reaction can be used as a timely surrogate marker to evaluate the appropriateness of antibiotic usage. Prospective observational study. University hospital and research laboratory. Patients with culture-proven A. baumannii bacteremia in the intensive care units were prospectively enrolled from April 2008 to February 2009. Plasmid Oxa-51/pCRII-TOPO, which contained a 431-bp fragment of the A. baumannii-specific Oxa-51 gene in a pCRII-TOPO vector, was used as the standard. Sequential bacterial DNA loads in the blood were measured by a quantitative polymerase chain reaction assay. We enrolled 51 patients with A. baumannii bacteremia, and examined 318 sequential whole blood samples. The initial mean bacterial load was 2.15 log copies/mL, and the rate of bacterial clearance was 0.088 log copies/mL/day. Multivariate linear regression using the generalized estimation equation approach revealed that the use of immunosuppressants was an independent predictor for slower bacterial clearance (coefficient, 1.116; pcritical patients. These findings highlight the importance of appropriate antibiotic usage and development of effective antibiotics against A. baumannii in an era of emerging antibiotic resistance. The rate of bacterial clearance could serve as a timely surrogate marker for evaluating the appropriateness of antibiotics.

Prolongation of rat heart allografts by donor-specific blood transfusion treated with ultraviolet irradiation

International Nuclear Information System (INIS)

Oluwole, S.F.; Iga, C.; Lau, H.; Hardy, M.A.

1985-01-01

The effect of donor-specific blood transfusion was compared to that of UVB-irradiated donor-specific blood transfusion on heart allograft survival in inbred rats with major histocompatibility differences. In one series ACI rats received heterotopic heart grafts from Lewis rats and 1 mL transfusion of donor-type blood at 1, 2, and 3 weeks prior to the transplantation. Fifty percent of the grafts were permanently accepted (survival greater than 200 days). Following UVB-irradiated donor-specific blood transfusion, 55% of the grafts survived indefinitely. In a mixed lymphocyte reaction ACI lymphocytes are weak responders to Lewis lymphocytes. In another series, Lewis rats received ACI hearts. Donor-specific transfusions at 1, 2, and 3 weeks prior to transplantation did not significantly alter the survival of heart allografts. Lewis lymphocytes react strongly to ACI stimulator cells in a mixed lymphocyte reaction. However, when the donor blood was UVB-irradiated prior to transfusion, the ACI allograft survival was significantly prolonged in this ACI-to-Lewis strain combination. When Lewis rats received W/F hearts following either donor-specific or UVB-irradiated donor-specific transfusions, the hearts' survival was similarly and significantly prolonged, but did not become permanent. Mixed lymphocyte reaction reveals that the stimulation index of Lewis lymphocytes against W/F lymphocytes is greater than that of ACI versus Lewis, but is less than that between Lewis responder cells against ACI stimulators

Challenge for real-time and real-space resolved spectroscopy of surface chemical reactions. Aiming at trace of irreversible and inhomogeneous reactions

International Nuclear Information System (INIS)

Amemiya, Kenta

2015-01-01

A novel experimental technique, time-resolved wavelength-dispersive soft X-ray imaging spectroscopy, is proposed in order to achieve real-time and real-space resolved spectroscopy for the observation of irreversible and inhomogeneous surface chemical reactions. By combining the wavelength-dispersed soft X rays, in which the X-ray wavelength (photon energy) changes as a function of position on the sample, with the photoelectron emission microscope, the soft X-ray absorption spectra are separately obtained at different positions on the sample without scanning the X-ray monochromator. Therefore, the real-time resolved measurement of site-selective soft X-ray absorption spectroscopy is realized in one event without repeating the chemical reaction. It is expected that the spatial distribution of different chemical species is traced during the surface chemical reaction, which is essential to understand the reaction mechanism. (author)

Prolongation of bleeding time and inhibition of platelet aggregation by low-dose acetylsalicylic acid in patients with cerebrovascular disease

DEFF Research Database (Denmark)

Boysen, G; Boss, A H; Ødum, Niels

1984-01-01

the bleeding time averaged 11.2 minutes in contrast to 7.0 minutes in the placebo group, p less than 0.001. This study confirms our previous findings of platelet inhibition by low-dose acetylsalicylic acid in patients with cerebrovascular disease. The prolongation of the bleeding time demonstrates that we......Platelet aggregation and bleeding time was measured in 43 cerebrovascular patients participating in a controlled double-blind study of low-dose acetylsalicylic acid. In 19 patients with satisfactory inhibition of the platelet aggregation obtained by 50 to 70 mg acetylsalicylic acid per day...... are dealing not merely with an in vitro phenomenon but with a significant in vivo effect. The study provides the rationale for clinical evaluations of low-dose acetylsalicylic acid in stroke prophylaxis....

Time-dependent, many-body scattering theory and nuclear reaction applications

International Nuclear Information System (INIS)

Levin, F.S.

1977-01-01

The channel component state form of the channel coupling array theory of many-body scattering is briefly reviewed. These states obey a non-hermitian matrix equation whose exact solution yields the Schroedinger eigenstates, eigenvalues and scattering amplitudes. A time-dependent formulation of the theory is introduced in analogy to the time-dependent Schrodinger equation and several consequences of the development are noted. These include an interaction picture, a single (matrix) S operator, and the usual connection between the t = 0 time-dependent and the time-independent scattering states. Finally, the channel component states (psi/sub j/) are shown to have the useful property that only psi/sub j/ has (two-body) outgoing waves in channel j: psi/sub m/, m not equal to j, is asymptotically zero in two-body channel j. This formalism is then considered as a means for direct nuclear reaction analysis. Typical bound state approximations are introduced and it is shown that a DWBA amplitude occurs in only one channel. The non-time-reversal invariance of the approximate theory is noted. Results of calculations based on a realistic model for two sets of light-ion induced, one-particle transfer reactions are discussed and compared with the coupled reaction channel (CRC) results using the CRC procedure of Cotanch and Vincent. Angular distributions for the two calculational methods are found to be similar in shape and magnitude. Higher ordercorrections are small as are time-reversal non-invariant effects. Post- and prior-type CRC calculations are seen to differ; the latter are closer to the full CRC results

Relativistic nucleus-nucleus collisions: Zone of reactions and space-time structure of fireball

International Nuclear Information System (INIS)

Anchishkin, D.; Muskeyev, A.; Yezhov, S.

2010-01-01

A zone of reactions is determined and then exploited as a tool in studying the space-time structure of an interacting system formed in a collision of relativistic nuclei. The time dependence of the reaction rates integrated over spatial coordinates is also considered. Evaluations are made with the help of the microscopic transport model UrQMD. The relation of the boundaries of different zones of reactions and the hypersurfaces of sharp chemical and kinetic freeze-outs is discussed.

Temporal Frequency Modulates Reaction Time Responses to First-Order and Second-Order Motion

Science.gov (United States)

Hutchinson, Claire V.; Ledgeway, Tim

2010-01-01

This study investigated the effect of temporal frequency and modulation depth on reaction times for discriminating the direction of first-order (luminance-defined) and second-order (contrast-defined) motion, equated for visibility using equal multiples of direction-discrimination threshold. Results showed that reaction times were heavily…

Rates and risks for prolonged grief disorder in a sample of orphaned and widowed genocide survivors.

Science.gov (United States)

Schaal, Susanne; Jacob, Nadja; Dusingizemungu, Jean-Pierre; Elbert, Thomas

2010-07-06

The concept of Prolonged Grief Disorder (PGD) has been defined in recent years by Prigerson and co-workers, who have developed and empirically tested consensus and diagnostic criteria for PGD. Using these most recent criteria defining PGD, the aim of this study was to determine rates of and risks for PGD in survivors of the 1994 Rwandan genocide who had lost a parent and/or the husband before, during or after the 1994 events. The PG-13 was administered to 206 orphans or half orphans and to 194 widows. A regression analysis was carried out to examine risk factors of PGD. 8.0% (n = 32) of the sample met criteria for PGD with an average of 12 years post-loss. All but one person had faced multiple losses and the majority indicated that their grief-related loss was due to violent death (70%). Grief was predicted mainly by time since the loss, by the violent nature of the loss, the severity of symptoms of posttraumatic stress disorder (PTSD) and the importance given to religious/spiritual beliefs. By contrast, gender, age at the time of bereavement, bereavement status (widow versus orphan), the number of different types of losses reported and participation in the funeral ceremony did not impact the severity of prolonged grief reactions. A significant portion of the interviewed sample continues to experience grief over interpersonal losses and unresolved grief may endure over time if not addressed by clinical intervention. Severity of grief reactions may be associated with a set of distinct risk factors. Subjects who lose someone through violent death seem to be at special risk as they have to deal with the loss experience as such and the traumatic aspects of the loss. Symptoms of PTSD may hinder the completion of the mourning process. Religious beliefs may facilitate the mourning process and help to find meaning in the loss. These aspects need to be considered in the treatment of PGD.

Hippocampal Abnormalities after Prolonged Febrile Convulsions

Directory of Open Access Journals (Sweden)

J Gordon Millichap

2003-11-01

Full Text Available Hippocampal volume and T2 relaxation times were determined in an MRI study of 14 children with prolonged febrile convulsions (PFC who were investigated, 1 within 5 days of a PFC, and 2 at follow-up 4-8 months after the acute study, at the Institute of Child Health, University College, and Great Ormond Street Hospital, London, UK.

Effects of uncertainty, transmission type, driver age and gender on brake reaction and movement time.

Science.gov (United States)

Warshawsky-Livne, Lora; Shinar, David

2002-01-01

Braking time (BT) is a critical component in safe driving, and various approaches have been applied to minimize it. This study analyzed the components of BT in order to assess the effects of age, gender, vehicle transmission type, and event uncertainty, on its two primary components, perception-reaction time and brake-movement time. Perception-reaction time and brake-movement time were measured at the onset of lights for 72 subjects in a simulator. The six experimental conditions were three levels of uncertainty conditions (none, some, and some + false alarms) and two types of transmission (manual and automatic). The 72 subjects, half male and half female, were further divided into three age groups (mean of 23, 30, and 62 years). Each subject had 10 trials in each of the three levels of uncertainty conditions. Transmission type did not significantly affect either perception-reaction time or brake-movement time. Perception-reaction time increased significantly from 0.32 to 0.42 s (P brake-movement time did not change. Perception-reaction time increased (from 0.35 to 0.43 s) with age but brake-movement time did not change with age. Gender did not affect perception-reaction time but did affect brake-movement time (males 0.19 s vs. females 0.16 s). At 90 km/h, a car travels 0.25 m in 0.01 s. Consequently, even such small effects multiplied by millions of vehicle-kilometers can contribute to significant savings in lives and damages.

SALIVARY ANTIMICROBIAL PROTEIN RESPONSE TO PROLONGED RUNNING

Directory of Open Access Journals (Sweden)

Suzanne Schneider

2013-01-01

Full Text Available Prolonged exercise may compromise immunity through a reduction of salivary antimicrobial proteins (AMPs. Salivary IgA (IgA has been extensively studied, but little is known about the effect of acute, prolonged exercise on AMPs including lysozyme (Lys and lactoferrin (Lac. Objective: To determine the effect of a 50-km trail race on salivary cortisol (Cort, IgA, Lys, and Lac. Methods: 14 subjects: (6 females, 8 males completed a 50km ultramarathon. Saliva was collected pre, immediately after (post and 1.5 hrs post race ( 1.5. Results: Lac concentration was higher at 1.5 hrs post race compared to post exercise (p0.05. IgA concentration, secretion rate, and IgA/Osm were lower 1.5 hrs post compared to pre race (p<0.05. Cort concentration was higher at post compared to 1.5 (p<0.05, but was unaltered from pre race levels. Subjects finished in 7.81 ± 1.2 hrs. Saliva flow rate did not differ between time points. Saliva Osm increased at post (p<0.05 compared to pre race. Conclusions: The intensity could have been too low to alter Lys and Lac secretion rates and thus, may not be as sensitive as IgA to changes in response to prolonged running. Results expand our understanding of the mucosal immune system and may have implications for predicting illness after prolonged running.

Spatial variability of excess mortality during prolonged dust events in a high-density city: a time-stratified spatial regression approach.

Science.gov (United States)

Wong, Man Sing; Ho, Hung Chak; Yang, Lin; Shi, Wenzhong; Yang, Jinxin; Chan, Ta-Chien

2017-07-24

Dust events have long been recognized to be associated with a higher mortality risk. However, no study has investigated how prolonged dust events affect the spatial variability of mortality across districts in a downwind city. In this study, we applied a spatial regression approach to estimate the district-level mortality during two extreme dust events in Hong Kong. We compared spatial and non-spatial models to evaluate the ability of each regression to estimate mortality. We also compared prolonged dust events with non-dust events to determine the influences of community factors on mortality across the city. The density of a built environment (estimated by the sky view factor) had positive association with excess mortality in each district, while socioeconomic deprivation contributed by lower income and lower education induced higher mortality impact in each territory planning unit during a prolonged dust event. Based on the model comparison, spatial error modelling with the 1st order of queen contiguity consistently outperformed other models. The high-risk areas with higher increase in mortality were located in an urban high-density environment with higher socioeconomic deprivation. Our model design shows the ability to predict spatial variability of mortality risk during an extreme weather event that is not able to be estimated based on traditional time-series analysis or ecological studies. Our spatial protocol can be used for public health surveillance, sustainable planning and disaster preparation when relevant data are available.

Smoking prolongs the infectivity of patients with tuberculosis.

LENUS (Irish Health Repository)

Siddiqui, U A

2010-10-01

We sought to establish if smokers on anti-tuberculosis treatment are more likely to have a prolonged period of infectivity, compared to non-smoking tuberculosis patients, in a low tuberculosis prevalence country. We conducted a cross-sectional, retrospective study in Ireland that recruited 53 microbiologically confirmed cases of pulmonary tuberculosis (PTB). The age-sex adjusted odds ratios (AOR) suggest that the infectivity status of PTB on treatment was four times more likely to be prolonged beyond 6-8 weeks, if the cases had a smoking history (AOR: 4.42; 95% CI: 1.23; 15.9). Smoking was associated with delayed sputum smear conversion in PTB patients on treatment.

Time-resolved FTIR emission studies of laser photofragmentation and radical reactions

Energy Technology Data Exchange (ETDEWEB)

Leone, S.R. [Univ. of Colorado, Boulder (United States)

1993-12-01

Recent studies have focused specifically on collision processes, such as single collision energy transfer, reaction dynamics, and radical reactions. The authors employ novel FTIR techniques in the study of single collision energy transfer processes using translationally fast H atom, as well as radical-radical reactions, e.g. CH{sub 3} + O, CF{sub 3} + H(D), and Cl + C{sub 2}H{sub 5}. The fast atoms permit unique high energy regions of certain transition states of combustion species to be probed for the first time.

Licence prolongations of US nuclear power plants; Les prolongations de licence des centrales nucleaires americaines

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-04-01

Licences of US nuclear reactors were initially attributed for a 40 years duration. However, the vast majority of the reactors can benefit of a licence prolongation for a period of 20 years maximum. This article recalls first the procedure to follow for the licence prolongation demands (safety analysis, components aging, environmental impact statement), and then it makes a status of the accepted prolongations, of the demands under examination, and of the demands that should be presented in the next 5 years. (J.S.)

Subchondral insufficiency fracture of the knee: a non-traumatic injury with prolonged recovery time.

Science.gov (United States)

Gourlay, Margaret L; Renner, Jordan B; Spang, Jeffrey T; Rubin, Janet E

2015-06-08

Subchondral insufficiency fractures are non-traumatic fractures that occur immediately below the cartilage of a joint. Although low bone density may be present concurrently, it is not the underlying cause of subchondral insufficiency fractures in the majority of patients. Patients with subchondral insufficiency fracture characteristically have unremarkable plain radiographs, while MRI examination may reveal extensive bone marrow oedema and subchondral bone collapse. This article presents a 51-year-old postmenopausal woman, a physician, who had subchondral insufficiency fractures of the knee associated with prolonged standing during clinical work. She was treated with partial weight bearing on crutches until 14 months after the injury, viscosupplementation at 4 months to treat osteoarthritis and teriparatide treatment to improve bone healing at 7 months. By 26 months after the injury, she tolerated independent walking with a fabric knee support but still experienced mild posterolateral knee pain and numbness on prolonged standing. 2015 BMJ Publishing Group Ltd.

Survival without sequelae after prolonged cardiopulmonary resuscitation after electric shock.

Science.gov (United States)

Motawea, Mohamad; Al-Kenany, Al-Sayed; Hosny, Mostafa; Aglan, Omar; Samy, Mohamad; Al-Abd, Mohamed

2016-03-01

"Electrical shock is the physiological reaction or injury caused by electric current passing through the human body. It occurs upon contact of a human body part with any source of electricity that causes a sufficient current through the skin, muscles, or hair causing undesirable effects ranging from simple burns to death." Ventricular fibrillation is believed to be the most common cause of death after electrical shock. "The ideal duration of cardiac resuscitation is unknown. Typically prolonged cardiopulmonary resuscitation is associated with poor neurologic outcomes and reduced long term survival. No consensus statement has been made and traditionally efforts are usually terminated after 15-30 minutes." The case under discussion seems worthy of the somewhat detailed description given. It is for a young man who survived after 65 minutes after electrical shock (ES) after prolonged high-quality cardiopulmonary resuscitation (CPR), multiple defibrillations, and artificial ventilation without any sequelae. Early start of adequate chest compressions and close adherence to advanced cardiac life support protocols played a vital role in successful CPR.

Prolonged bone marrow T1-relaxation in patients with polycythemia vera

DEFF Research Database (Denmark)

Jensen, K E; Grube, T; Thomsen, C

1988-01-01

In vitro as well as in vivo studies have shown prolonged T1 relaxation times in patients with acute leukemia. The mechanism behind this finding is not known. In order to evaluate if this was specific for leukemia we examined eight patients with polycythemia vera, representing a condition with a r......In vitro as well as in vivo studies have shown prolonged T1 relaxation times in patients with acute leukemia. The mechanism behind this finding is not known. In order to evaluate if this was specific for leukemia we examined eight patients with polycythemia vera, representing a condition...

Vestibular stimulation after head injury: effect on reaction times and motor speech parameters

DEFF Research Database (Denmark)

Engberg, A

1989-01-01

Earlier studies by other authors indicate that vestibular stimulation may improve attention and dysarthria in head injured patients. In the present study of five severely head injured patients and five controls, the effect of vestibular stimulation on reaction times (reflecting attention) and some...... motor speech parameters (reflecting dysarthria) was investigated. After eight weeks with regular stimulation, it was concluded that reaction time changes were individual and consistent for a given subject. Only occasionally were they shortened after stimulation. However, reaction time was lengthened...... in three cases, prohibiting further stimulation in one case. Motion sickness was prohibitive in a second case. However, after-stimulation increase of phonation time and/or vital capacity was found in one patient and four controls. Oral diadochokinetic rates were slowed in several cases. Collectively, when...

Ways to Optimize Therapy of Prolonged Conjugation Jaundice in Infants

Directory of Open Access Journals (Sweden)

O.G. Shadrin

2015-09-01

Full Text Available The article is devoted to the optimization of the treatment of prolonged conjugation jaundice. Inclusion of ursodeoxycholic acid in the treatment of neonatal prolonged conjugation jaundice in a dose of 15–20 mg/kg of body mass per day increases the terms of regression of clinical and paraclinical signs of jaundice as much as 2 times and leads to cytolysis normalization. The preparation has a sufficient level of safety, there were not revealed side effects whilst its application.

Quality of drug label information on QT interval prolongation

DEFF Research Database (Denmark)

Warnier, Miriam J; Holtkamp, Frank A; Rutten, Frans H

2014-01-01

BACKGROUND: Information regarding QT-prolongation in the drug label may vary between products. This could lead to suboptimal risk minimization strategies. OBJECTIVE: To systematically assess the variation in the extent and content of information on QT prolongation in the summary of product......-prolongation'/'QT-prolongation') and the advice on cautionary measures pertaining to QT-prolongation in the label were examined, as well as their association. RESULTS: Of the 175 screened products, 44 contained information on QT in the SPC ('no QT-prolongation': 23%, 'unclear drug-QT association': 43%, 'possibly QT-prolongation': 16%, 'QT......-prolongation': 18%). 62% contained advices to act with caution in patients with additional risk factors for QT-prolongation. Products that more likely to have QT-prolonging properties according to the SPC provided more information on QT-prolongation in the SPC ('no prolongation': 10% and for the category 'QT...

Behavioral changes over time in post-traumatic stress disorder: Insights from a rat model of single prolonged stress.

Science.gov (United States)

Wu, Zhuoyun; Tian, Qing; Li, Feng; Gao, Junqiao; Liu, Yan; Mao, Meng; Liu, Jing; Wang, Shuyan; Li, Genmao; Ge, Dongyu; Mao, Yingqiu; Zhang, Wei; Liu, Zhaolan; Song, Yuehan

2016-03-01

Post-traumatic stress disorder (PTSD) is manifested as a persistent mental and emotional condition after potentially life-threatening events. Different animal models of PTSD have been developed for neuro-pathophysiology and pharmacological evaluations. A single prolonged stress (SPS) induced animal model has demonstrated to result in specific neuro-endocrinological dysregulation, and behavior abnormalities observed in PTSD. However, animal studies of PTSD have mostly been performed at one time point after SPS exposure. To better understand the development of PTSD-like behaviors in the SPS animal model, and to identify an optimal period of study, we examined depressive behavior, anxiety-like behavior, physical activity and body weight in SPS model rats for two weeks. Our results confirmed the SPS-induced PTSD-like behavior and physical activity observed in previous studies, and indicated that the most pronounced symptomatic behavior changes were observed on day 1 and 7 after SPS exposure, which may involve stress-induced acute hormone changes and unclear secondary neurobiological changes, respectively. These results provide a solid basis for further investigation into the neuro-pathophysiology of or neuropharmacology for PTSD using the SPS rat model. However, for chronic (pharmacological) studies longer than 7 days, a prolonged PTSD animal model should be developed, perhaps using enhanced stimulation. Copyright © 2016 Elsevier B.V. All rights reserved.

The effects of reactants ratios, reaction temperatures and times on Maillard reaction products of the L-ascorbic acid/L-glutamic acid system

Directory of Open Access Journals (Sweden)

Yong-Yan ZHOU

2016-01-01

Full Text Available Abstract The transformation law of the Maillard reaction products with three different reactants ratios - equimolar reactants, excess L-glutamic acid and excess L-ascorbic acid reaction respectively, five different temperatures, and different time conditions for the L-ascorbic acid / L-glutamic acid system were investigated. Results showed that, the increase of the reaction time and temperature led to the increase of the browning products, uncoloured intermediate products, as well as aroma compounds. Compared with the equimolar reaction system, the excess L-ascorbic acid reaction system produced more browning products and uncoloured intermediate products, while the aroma compounds production remained the same. In the excess L-glutamic acid system, the uncoloured intermediate products increased slightly, the browning products remained the same, while the aroma compounds increased.

The formation of illite from nontronite by mesophilic and thermophilic bacterial reaction

Science.gov (United States)

Jaisi, Deb P.; Eberl, Dennis D.; Dong, Hailiang; Kim, Jinwook

2011-01-01

The formation of illite through the smectite-to-illite (S-I) reaction is considered to be one of the most important mineral reactions occurring during diagenesis. In biologically catalyzed systems, however, this transformation has been suggested to be rapid and to bypass the high temperature and long time requirements. To understand the factors that promote the S-I reaction, the present study focused on the effects of pH, temperature, solution chemistry, and aging on the S-I reaction in microbially mediated systems. Fe(III)-reduction experiments were performed in both growth and non-growth media with two types of bacteria: mesophilic (Shewanella putrefaciens CN32) and thermophilic (Thermus scotoductus SA-01). Reductive dissolution of NAu-2 was observed and the formation of illite in treatment with thermophilic SA-01 was indicated by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). A basic pH (8.4) and high temperature (65°C) were the most favorable conditions for the formation of illite. A long incubation time was also found to enhance the formation of illite. K-nontronite (non-permanent fixation of K) was also detected and differentiated from the discrete illite in the XRD profiles. These results collectively suggested that the formation of illite associated with the biologically catalyzed smectite-to-illite reaction pathway may bypass the prolonged time and high temperature required for the S-I reaction in the absence of microbial activity.

Primiparous women's preferences for care during a prolonged latent phase of labour.

Science.gov (United States)

Ängeby, Karin; Wilde-Larsson, Bodil; Hildingsson, Ingegerd; Sandin-Bojö, Ann-Kristin

2015-10-01

To investigate primiparous women's preferences for care during a prolonged latent phase of labour. A qualitative study based on focus groups and individual interviews and analysed with inductive content analysis. Sixteen primiparous women with a prolonged latent phase of labour >18 hours were interviewed in five focus groups (n = 11) or individually (n = 5). One main category emerged "Beyond normality - a need of individual adapted guidance in order to understand and manage an extended latent phase of labour" which covers the women's preferences during the prolonged latent phase. Five categories were generated from the data: "A welcoming manner and not being rejected", "Individually adapted care", "Important information which prepares for reality and coping", "Participation and need for feedback" and "Staying nearby the labour ward or being admitted for midwifery support". Women with a prolonged latent phase of labour sought to use their own resources, but their needs for professional support increased as time passed. A welcoming attitude from an available midwife during the latent phase created a feeling of security, and personally adapted care was perceived positively. Women with a prolonged latent phase of labour preferred woman-centred care. Midwives play an important role in supporting these women. Women's need for midwifery-support increases as the time spent in latent phase increases. Copyright © 2015 Elsevier B.V. All rights reserved.

A critical review of Richard Lynn's reports on reaction time and race.

Science.gov (United States)

Thomas, Drew M

2011-01-01

In the early 1990s, psychologist Richard Lynn published papers documenting average reaction times and decision times in samples of nine-year-olds taken from across the world. After summarizing these data, Lynn interpreted his results as evidence of national and racial differences in decision time and general intelligence. Others have also interpreted Lynn's data as evidence of racial differences in decision time and intelligence. However, comparing Lynn's summaries with his original reports shows that Lynn misreported and omitted some of his own data. Once these errors are fixed the rankings of nations in Lynn's datasets are unstable across different decision time measures. This instability, as well as within-race heterogeneity and between-race overlap in decision times, implies that Lynn's reaction time data do not permit generalizations about the decision times and intelligence of people of different races.

The decreased influence of overall treatment time on the response of human breast tumor xenografts following prolongation of the potential doubling time (T{sub pot})

Energy Technology Data Exchange (ETDEWEB)

Sarkaria, Jann N; Fowler, John F; Lindstrom, Mary J; Jordan, V Craig; Mulcahy, R Timothy

1995-02-15

Purpose: Repopulation during fractionated radiotherapy has been postulated to result in a significant loss in local control in rapidly proliferating tumors. Clinical data suggest that accelerated fractionation schedules can overcome the influence of repopulation by limiting the overall treatment time. Unfortunately, accelerated therapy frequently leads to increased acute reactions, which may become dose limiting. An alternative to accelerated fractionation would be to decrease the rate of repopulation during therapy. To test the potential efficacy of this alternative, we examined the effect of reducing tumor proliferation rate on the response of MCF-7 human breast carcinoma xenografts treated with a short vs. a long course of fractionated therapy. To reduce the proliferation rate, we deprived nude mice transplanted with MCF-7 xenografts of the growth-stimulating hormone estradiol (E{sub 2}). We have previously reported that E{sub 2} deprivation increases the potential doubling time (T{sub pot}) for MCF-7 xenografts from a mean of 2.6 days to 5.3 days (p < 0.001). Methods and Materials: E{sub 2}-stimulated and E{sub 2}-deprived MCF-7 breast carcinoma xenografts were clamped hypoxically and irradiated with four fractions of 5 Gy each, using either a short (3-day) or long (9-day) treatment course. E{sub 2} stimulation was restored in all animals at the completion of irradiation. Radiation response was determined by regrowth time and regrowth delay of the irradiated tumors as compared to unirradiated controls. Results: Prolongation of therapy in rapidly proliferating, E{sub 2}-stimulated tumors (T{sub pot} {approx} 2.6 days) resulted in a significant decrease in regrowth time in two identical experiments. With results pooled for analysis, the regrowth times for the short and long treatments were 62 and 32 days, respectively (combined p < 0.001). The shorter regrowth times suggest that there was less overall tumor damage with the longer fractionated radiotherapy course

Prolonged pregnancy: Methods, Causal Determinants and Outcome

DEFF Research Database (Denmark)

Olesen, Annette Wind

Summary Prolonged pregnancy, defined as a pregnancy with a gestational length of 294 days or more, is a frequent condition. It is associated with an increased risk of fetal and maternal complications. Little is known about the aetiology of prolonged pregnancy. The aims of the thesis were 1......) to study the incidence of prolonged pregnancy as a function of methods for determining gestational age; 2) to determine the risk of obstetrical and fetal complications in prolonged pregnancy; 3) to validate the self-reported gestational age in the National Birth Cohort; 4) to determine whether...... the risk of recurrence of prolonged pregnancy as a function of change in male partner and social conditions (IV). The National Birth Cohort provided data for the study on prenatal risk indicators of prolonged pregnancy in a follow-up design (V). The self-reported gestational ages from this database...

Prolonged CT urography in duplex kidney.

Science.gov (United States)

Gong, Honghan; Gao, Lei; Dai, Xi-Jian; Zhou, Fuqing; Zhang, Ning; Zeng, Xianjun; Jiang, Jian; He, Laichang

2016-05-13

Duplex kidney is a common anomaly that is frequently associated with multiple complications. Typical computed tomography urography (CTU) includes four phases (unenhanced, arterial, parenchymal and excretory) and has been suggested to considerably aid in the duplex kidney diagnosi. Unfortunately, regarding duplex kidney with prolonged dilatation, the affected parenchyma and tortuous ureters demonstrate a lack of or delayed excretory opacification. We used prolonged-delay CTU, which consists of another prolonged-delay phase (1- to 72-h delay; mean delay: 24 h) to opacify the duplicated ureters and affected parenchyma. Seventeen patients (9 males and 8 females; age range: 2.5-56 y; mean age: 40.4 y) with duplex kidney were included in this study. Unenhanced scans did not find typical characteristics of duplex kidney, except for irregular perirenal morphology. Duplex kidney could not be confirmed on typical four-phase CTU, whereas it could be easily diagnosed in axial and CT-3D reconstruction using prolonged CTU (prolonged-delay phase). Between January 2005 and October 2010, in this review board-approved study (with waived informed consent), 17 patients (9 males and 8 females; age range: 2.5 ~ 56 y; mean age: 40.4 y) with suspicious duplex kidney underwent prolonged CTU to opacify the duplicated ureters and confirm the diagnosis. Our results suggest the validity of prolonged CTU to aid in the evaluation of the function of the affected parenchyma and in the demonstration of urinary tract malformations.

Physical attraction to reliable, low variability nervous systems: Reaction time variability predicts attractiveness.

Science.gov (United States)

Butler, Emily E; Saville, Christopher W N; Ward, Robert; Ramsey, Richard

2017-01-01

The human face cues a range of important fitness information, which guides mate selection towards desirable others. Given humans' high investment in the central nervous system (CNS), cues to CNS function should be especially important in social selection. We tested if facial attractiveness preferences are sensitive to the reliability of human nervous system function. Several decades of research suggest an operational measure for CNS reliability is reaction time variability, which is measured by standard deviation of reaction times across trials. Across two experiments, we show that low reaction time variability is associated with facial attractiveness. Moreover, variability in performance made a unique contribution to attractiveness judgements above and beyond both physical health and sex-typicality judgements, which have previously been associated with perceptions of attractiveness. In a third experiment, we empirically estimated the distribution of attractiveness preferences expected by chance and show that the size and direction of our results in Experiments 1 and 2 are statistically unlikely without reference to reaction time variability. We conclude that an operating characteristic of the human nervous system, reliability of information processing, is signalled to others through facial appearance. Copyright © 2016 Elsevier B.V. All rights reserved.

Delay differential equations and the dose-time dependence of early radiotherapy reactions

International Nuclear Information System (INIS)

Fenwick, John D.

2006-01-01

The dose-time dependence of early radiotherapy reactions impacts on the design of accelerated fractionation schedules--oral mucositis, for example, can be dose limiting for short treatments designed to avoid tumor repopulation. In this paper a framework for modeling early reaction dose-time dependence is developed. Variation of stem cell number with time after the start of a radiation schedule is modeled using a first-order delay differential equation (DDE), motivated by experimental observations linking the speed of compensatory proliferation in early reacting tissues to the degree of tissue damage. The modeling suggests that two types of early reaction radiation response are possible, stem cell numbers either monotonically approaching equilibrium plateau levels or overshooting before returning to equilibrium. Several formulas have been derived from the delay differential equation, predicting changes in isoeffective total radiation dose with schedule duration for different types of fractionation scheme. The formulas have been fitted to a wide range of published animal early reaction data, the fits all implying a degree of overshoot. Results are presented illustrating the scope of the delay differential model: most of the data are fitted well, although the model struggles with a few datasets measured for schedules with distinctive dose-time patterns. Ways of extending the current model to cope with these particular dose-time patterns are briefly discussed. The DDE approach is conceptually more complex than earlier descriptive dose-time models but potentially more powerful. It can be used to study issues not addressed by simpler models, such as the likely effects of increasing or decreasing the dose-per-day over time, or of splitting radiation courses into intense segments separated by gaps. It may also prove useful for modeling the effects of chemoirradiation

Delay differential equations and the dose-time dependence of early radiotherapy reactions.

Science.gov (United States)

Fenwick, John D

2006-09-01

The dose-time dependence of early radiotherapy reactions impacts on the design of accelerated fractionation schedules--oral mucositis, for example, can be dose limiting for short treatments designed to avoid tumor repopulation. In this paper a framework for modeling early reaction dose-time dependence is developed. Variation of stem cell number with time after the start of a radiation schedule is modeled using a first-order delay differential equation (DDE), motivated by experimental observations linking the speed of compensatory proliferation in early reacting tissues to the degree of tissue damage. The modeling suggests that two types of early reaction radiation response are possible, stem cell numbers either monotonically approaching equilibrium plateau levels or overshooting before returning to equilibrium. Several formulas have been derived from the delay differential equation, predicting changes in isoeffective total radiation dose with schedule duration for different types of fractionation scheme. The formulas have been fitted to a wide range of published animal early reaction data, the fits all implying a degree of overshoot. Results are presented illustrating the scope of the delay differential model: most of the data are fitted well, although the model struggles with a few datasets measured for schedules with distinctive dose-time patterns. Ways of extending the current model to cope with these particular dose-time patterns are briefly discussed. The DDE approach is conceptually more complex than earlier descriptive dose-time models but potentially more powerful. It can be used to study issues not addressed by simpler models, such as the likely effects of increasing or decreasing the dose-per-day over time, or of splitting radiation courses into intense segments separated by gaps. It may also prove useful for modeling the effects of chemoirradiation.

Assessment of pedophilic sexual interest with an attentional choice reaction time task.

Science.gov (United States)

Mokros, Andreas; Dombert, Beate; Osterheider, Michael; Zappalà, Angelo; Santtila, Pekka

2010-10-01

Choice-reaction time (CRT) is an experimental information-processing paradigm. Based on an interference effect in visual attention, the CRT method has been shown to be suitable for measuring sexual orientation in men and women. The present study assessed the potential of the CRT to identify deviant (i.e., pedophilic) sexual interest. Participants were patients from forensic-psychiatric hospitals: 21 child molesters and 21 non-sex offenders. The dependent variable was reaction time in an ostensible seek-and-locate task (i.e., identifying the position of a dot superimposed on a picture of a person). There was an interaction effect between stimulus age category and participant group status: Child molesters took longer to respond to pictures of children relative to pictures of adults. Non-sex offenders showed an opposite pattern (i.e., longer reaction times with pictures of adults than with pictures of children). In addition, the data supported the notion of sexual content induced delay: Subjects took longer for the task with nude stimuli than with clothed ones. A subtractive preference index, derived from the reaction times for child and adult stimulus material, allowed distinguishing participants from both groups almost perfectly (ROC-AUC = .998). We conclude that a match of sexual interest with properties of visual stimuli led to a cognitive interference effect: Attentional resources were drawn from the ostensible task of locating the dot towards exploring the picture. This opens up the possibility of using this interference effect (i.e., the delay of response times) for diagnostic purposes.

Development of an Internal Real-Time Wireless Diagnostic Tool for a Proton Exchange Membrane Fuel Cell.

Science.gov (United States)

Lee, Chi-Yuan; Chen, Chia-Hung; Tsai, Chao-Hsuan; Wang, Yu-Syuan

2018-01-13

To prolong the operating time of unmanned aerial vehicles which use proton exchange membrane fuel cells (PEMFC), the performance of PEMFC is the key. However, a long-term operation can make the Pt particles of the catalyst layer and the pollutants in the feedstock gas bond together (e.g., CO), so that the catalyst loses reaction activity. The performance decay and aging of PEMFC will be influenced by operating conditions, temperature, flow and CO concentration. Therefore, this study proposes the development of an internal real-time wireless diagnostic tool for PEMFC, and uses micro-electro-mechanical systems (MEMS) technology to develop a wireless and thin (PEMFC; (5) customized design and development. The flexible integrated microsensor is embedded in the PEMFC, three important physical quantities in the PEMFC, which are the temperature, flow and CO, can be measured simultaneously and instantly, so as to obtain the authentic and complete reaction in the PEMFC to enhance the performance of PEMFC and to prolong the service life.

Real time monitoring of accelerated chemical reactions by ultrasonication-assisted spray ionization mass spectrometry.

Science.gov (United States)

Lin, Shu-Hsuan; Lo, Ta-Ju; Kuo, Fang-Yin; Chen, Yu-Chie

2014-01-01

Ultrasonication has been used to accelerate chemical reactions. It would be ideal if ultrasonication-assisted chemical reactions could be monitored by suitable detection tools such as mass spectrometry in real time. It would be helpful to clarify reaction intermediates/products and to have a better understanding of reaction mechanism. In this work, we developed a system for ultrasonication-assisted spray ionization mass spectrometry (UASI-MS) with an ~1.7 MHz ultrasonic transducer to monitor chemical reactions in real time. We demonstrated that simply depositing a sample solution on the MHz-based ultrasonic transducer, which was placed in front of the orifice of a mass spectrometer, the analyte signals can be readily detected by the mass spectrometer. Singly and multiply charged ions from small and large molecules, respectively, can be observed in the UASI mass spectra. Furthermore, the ultrasonic transducer used in the UASI setup accelerates the chemical reactions while being monitored via UASI-MS. The feasibility of using this approach for real-time acceleration/monitoring of chemical reactions was demonstrated. The reactions of Girard T reagent and hydroxylamine with steroids were used as the model reactions. Upon the deposition of reactant solutions on the ultrasonic transducer, the intermediate/product ions are readily generated and instantaneously monitored using MS within 1 s. Additionally, we also showed the possibility of using this reactive UASI-MS approach to assist the confirmation of trace steroids from complex urine samples by monitoring the generation of the product ions. Copyright © 2014 John Wiley & Sons, Ltd.

Transcriptional dynamics with time-dependent reaction rates

Science.gov (United States)

Nandi, Shubhendu; Ghosh, Anandamohan

2015-02-01

Transcription is the first step in the process of gene regulation that controls cell response to varying environmental conditions. Transcription is a stochastic process, involving synthesis and degradation of mRNAs, that can be modeled as a birth-death process. We consider a generic stochastic model, where the fluctuating environment is encoded in the time-dependent reaction rates. We obtain an exact analytical expression for the mRNA probability distribution and are able to analyze the response for arbitrary time-dependent protocols. Our analytical results and stochastic simulations confirm that the transcriptional machinery primarily act as a low-pass filter. We also show that depending on the system parameters, the mRNA levels in a cell population can show synchronous/asynchronous fluctuations and can deviate from Poisson statistics.

Transcriptional dynamics with time-dependent reaction rates

International Nuclear Information System (INIS)

Nandi, Shubhendu; Ghosh, Anandamohan

2015-01-01

Transcription is the first step in the process of gene regulation that controls cell response to varying environmental conditions. Transcription is a stochastic process, involving synthesis and degradation of mRNAs, that can be modeled as a birth–death process. We consider a generic stochastic model, where the fluctuating environment is encoded in the time-dependent reaction rates. We obtain an exact analytical expression for the mRNA probability distribution and are able to analyze the response for arbitrary time-dependent protocols. Our analytical results and stochastic simulations confirm that the transcriptional machinery primarily act as a low-pass filter. We also show that depending on the system parameters, the mRNA levels in a cell population can show synchronous/asynchronous fluctuations and can deviate from Poisson statistics. (paper)

Errors in Postural Preparation Lead to Increased Choice Reaction Times for Step Initiation in Older Adults

Science.gov (United States)

Nutt, John G.; Horak, Fay B.

2011-01-01

Background. This study asked whether older adults were more likely than younger adults to err in the initial direction of their anticipatory postural adjustment (APA) prior to a step (indicating a motor program error), whether initial motor program errors accounted for reaction time differences for step initiation, and whether initial motor program errors were linked to inhibitory failure. Methods. In a stepping task with choice reaction time and simple reaction time conditions, we measured forces under the feet to quantify APA onset and step latency and we used body kinematics to quantify forward movement of center of mass and length of first step. Results. Trials with APA errors were almost three times as common for older adults as for younger adults, and they were nine times more likely in choice reaction time trials than in simple reaction time trials. In trials with APA errors, step latency was delayed, correlation between APA onset and step latency was diminished, and forward motion of the center of mass prior to the step was increased. Participants with more APA errors tended to have worse Stroop interference scores, regardless of age. Conclusions. The results support the hypothesis that findings of slow choice reaction time step initiation in older adults are attributable to inclusion of trials with incorrect initial motor preparation and that these errors are caused by deficits in response inhibition. By extension, the results also suggest that mixing of trials with correct and incorrect initial motor preparation might explain apparent choice reaction time slowing with age in upper limb tasks. PMID:21498431

Hydrogen desorption reactions of Li-N-H hydrogen storage system: Estimation of activation free energy

International Nuclear Information System (INIS)

Matsumoto, Mitsuru; Haga, Tetsuya; Kawai, Yasuaki; Kojima, Yoshitsugu

2007-01-01

The dehydrogenation reactions of the mixtures of lithium amide (LiNH 2 ) and lithium hydride (LiH) were studied under an Ar atmosphere by means of temperature programmed desorption (TPD) technique. The dehydrogenation reaction of the LiNH 2 /LiH mixture was accelerated by addition of 1 mol% Ti(III) species (k = 3.1 x 10 -4 s -1 at 493 K), and prolonged ball-milling time (16 h) further enhanced reaction rate (k = 1.1 x 10 -3 s -1 at 493 K). For the hydrogen desorption reaction of Ti(III) doped samples, the activation energies estimated by Kissinger plot (95 kJ mol -1 ) and Arrhenius plot (110 kJ mol -1 ) were in reasonable agreement. The LiNH 2 /LiH mixture without Ti(III) species, exhibited slower hydrogen desorption process and the kinetic traces deviated from single exponential behavior. The results indicated the Ti(III) additives change the hydrogen desorption reaction mechanism of the LiNH 2 /LiH mixture

The influenced of reaction time on the degradation of palm oil empty fruit bunch (EFB) in hydrothermal carbonization

Science.gov (United States)

Sarwono, Rakhman; Kurniawan, Hendris Hendarsyah

2017-11-01

Hydrothermal carbonization (HTC) of empty fruit bunch (EFB) of palm oil in different reaction times were investigated. Experiments were carried out in an autoclave at different reaction time of 3,6,9, 15, 20, 25 and 40 hours. With a fixed solid/liquid ratio of 5 gram of EFB in 50 ml water as a solvent, and temperature reaction of 250 °C. Increase the reaction time the soluble products are also increased. The liquid products were analyzed using GCMS to determine the chemical composition. The chemical composition were greatly affected by the reaction time. The main component was glycolic acid, by increasing the reaction time made the varieties of chemical compositions in liquid products, especially for the glycolic acid component, it was decreased slightly. The higher heating value (HHV) also increase slighly by increasing the reaction time both solid and liquid products.

Competitive autocatalytic reactions in chaotic flows with diffusion: Prediction using finite-time Lyapunov exponents

International Nuclear Information System (INIS)

Schlick, Conor P.; Umbanhowar, Paul B.; Ottino, Julio M.; Lueptow, Richard M.

2014-01-01

We investigate chaotic advection and diffusion in autocatalytic reactions for time-periodic sine flow computationally using a mapping method with operator splitting. We specifically consider three different autocatalytic reaction schemes: a single autocatalytic reaction, competitive autocatalytic reactions, which can provide insight into problems of chiral symmetry breaking and homochirality, and competitive autocatalytic reactions with recycling. In competitive autocatalytic reactions, species B and C both undergo an autocatalytic reaction with species A such that A+B→2B and A+C→2C. Small amounts of initially spatially localized B and C and a large amount of spatially homogeneous A are advected by the velocity field, diffuse, and react until A is completely consumed and only B and C remain. We find that local finite-time Lyapunov exponents (FTLEs) can accurately predict the final average concentrations of B and C after the reaction completes. The species that starts in the region with the larger FTLE has, with high probability, the larger average concentration at the end of the reaction. If B and C start in regions with similar FTLEs, their average concentrations at the end of the reaction will also be similar. When a recycling reaction is added, the system evolves towards a single species state, with the FTLE often being useful in predicting which species fills the entire domain and which is depleted. The FTLE approach is also demonstrated for competitive autocatalytic reactions in journal bearing flow, an experimentally realizable flow that generates chaotic dynamics

Influence of prolonged cold ischemia in renal transplantation.

NARCIS (Netherlands)

Vliet, J.A. van der; Warle, M.C.; Cheung, C.L.; Teerenstra, S.; Hoitsma, A.J.

2011-01-01

van der Vliet JA, Warle MC, Cheung CLS, Teerenstra S, Hoitsma AJ. Influence of prolonged cold ischemia in renal transplantation. Clin Transplant 2011: 25: E612-E616. (c) 2011 John Wiley & Sons A/S. Abstract: Aim: To determine to what extent current cold ischemia times (CITs) affect the results of

On the deduction of chemical reaction pathways from measurements of time series of concentrations.

Science.gov (United States)

Samoilov, Michael; Arkin, Adam; Ross, John

2001-03-01

We discuss the deduction of reaction pathways in complex chemical systems from measurements of time series of chemical concentrations of reacting species. First we review a technique called correlation metric construction (CMC) and show the construction of a reaction pathway from measurements on a part of glycolysis. Then we present two new improved methods for the analysis of time series of concentrations, entropy metric construction (EMC), and entropy reduction method (ERM), and illustrate (EMC) with calculations on a model reaction system. (c) 2001 American Institute of Physics.

Effects of prolonged wakefulness combined with alcohol and hands-free cell phone divided attention tasks on simulated driving.

Science.gov (United States)

Iudice, A; Bonanni, E; Gelli, A; Frittelli, C; Iudice, G; Cignoni, F; Ghicopulos, I; Murri, L

2005-03-01

Simulated driving ability was assessed following administration of alcohol, at an estimated blood level of 0.05%, and combined prolonged wakefulness, while participants were undertaking divided attention tasks over a hands-free mobile phone. Divided attention tasks were structured to provide a sustained cognitive workload to the subjects. Twenty three young healthy individuals drove 10 km simulated driving under four conditions in a counterbalanced, within-subject design: alcohol, alcohol and 19 h wakefulness, alcohol and 24 h wakefulness, and while sober. Study measures were: simulated driving, self-reported sleepiness, critical flicker fusion threshold (CFFT), Stroop word-colour interference test (Stroop) and simple visual reaction times (SVRT). As expected, subjective sleepiness was highly correlated with both sleep restriction and alcohol consumption. The combination of alcohol and 24 h sustained wakefulness produced the highest driving impairment, significantly beyond the alcohol effect itself. Concurrent alcohol and 19 h wakefulness significantly affected only driving time-to-collision. No significant changes of study measures occurred following alcohol intake in unrestricted sleep conditions. CFFT, SVRT and Stroop results showed a similar trend in the four study conditions. Thus apparently 'safe' blood alcohol levels in combination with prolonged wakefulness resulted in significant driving impairments. In normal sleep conditions alcohol effects on driving were partially counteracted by the concomitant hands-free phone based psychometric tasks. 2005 John Wiley & Sons, Ltd.

On the search for an appropriate metric for reaction time to suprathreshold increments and decrements.

Science.gov (United States)

Vassilev, Angel; Murzac, Adrian; Zlatkova, Margarita B; Anderson, Roger S

2009-03-01

Weber contrast, DeltaL/L, is a widely used contrast metric for aperiodic stimuli. Zele, Cao & Pokorny [Zele, A. J., Cao, D., & Pokorny, J. (2007). Threshold units: A correct metric for reaction time? Vision Research, 47, 608-611] found that neither Weber contrast nor its transform to detection-threshold units equates human reaction times in response to luminance increments and decrements under selective rod stimulation. Here we show that their rod reaction times are equated when plotted against the spatial luminance ratio between the stimulus and its background (L(max)/L(min), the larger and smaller of background and stimulus luminances). Similarly, reaction times to parafoveal S-cone selective increments and decrements from our previous studies [Murzac, A. (2004). A comparative study of the temporal characteristics of processing of S-cone incremental and decremental signals. PhD thesis, New Bulgarian University, Sofia, Murzac, A., & Vassilev, A. (2004). Reaction time to S-cone increments and decrements. In: 7th European conference on visual perception, Budapest, August 22-26. Perception, 33, 180 (Abstract).], are better described by the spatial luminance ratio than by Weber contrast. We assume that the type of stimulus detection by temporal (successive) luminance discrimination, by spatial (simultaneous) luminance discrimination or by both [Sperling, G., & Sondhi, M. M. (1968). Model for visual luminance discrimination and flicker detection. Journal of the Optical Society of America, 58, 1133-1145.] determines the appropriateness of one or other contrast metric for reaction time.

Reaction time, processing speed and sustained attention in schizophrenia: impact on social functioning.

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Lahera, Guillermo; Ruiz, Alicia; Brañas, Antía; Vicens, María; Orozco, Arantxa

Previous studies have linked processing speed with social cognition and functioning of patients with schizophrenia. A discriminant analysis is needed to determine the different components of this neuropsychological construct. This paper analyzes the impact of processing speed, reaction time and sustained attention on social functioning. 98 outpatients between 18 and 65 with DSM-5 diagnosis of schizophrenia, with a period of 3 months of clinical stability, were recruited. Sociodemographic and clinical data were collected, and the following variables were measured: processing speed (Trail Making Test [TMT], symbol coding [BACS], verbal fluency), simple and elective reaction time, sustained attention, recognition of facial emotions and global functioning. Processing speed (measured only through the BACS), sustained attention (CPT) and elective reaction time (but not simple) were associated with functioning. Recognizing facial emotions (FEIT) correlated significantly with scores on measures of processing speed (BACS, Animals, TMT), sustained attention (CPT) and reaction time. The linear regression model showed a significant relationship between functioning, emotion recognition (P=.015) and processing speed (P=.029). A deficit in processing speed and facial emotion recognition are associated with worse global functioning in patients with schizophrenia. Copyright © 2017 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

Five different tests of reaction time evaluated in HIV seropositive men.

Science.gov (United States)

Dunlop, O; Bjørklund, R A; Abdelnoor, M; Myrvang, B

1992-09-01

In an attempt to develop a short neuropsychological test battery five different tests of reaction time were assessed according to their ability to discriminate between HIV seropositive men and healthy controls. In all tests a patient group with clinical symptoms was slower than the control group. In the complex reaction time test, which has a large cognitive aspect, even a clinically "asymptomatic" group was slower than the control group. The movement test, a new test with a large motor component, identified most slow responders, defining approximately half of the patients with clinical symptoms and one third of the "asymptomatic" patients as such. A test battery consisting of three tests is suggested for serial assessment and screening.

Sex hormone manipulation slows reaction time and increases labile mood in healthy women

DEFF Research Database (Denmark)

Stenbæk, D. S.; Fisher, P M; Budtz-Jørgensen, E.

2016-01-01

: In a randomized controlled double-blinded trial, 61 healthy women (mean age 24.3±4.9 years) were tested with measures of affective verbal memory, reaction time, mental distress, and serotonin transporter binding at baseline and at follow-up after receiving gonadotropin-releasing hormone agonist (GnRHa) or placebo...... intervention. Women also reported daily mood profiles during intervention. We tested direct effects of intervention and indirect effects through changes in serotonin transporter binding on verbal affective memory, simple reaction time and self-reported measures of mental distress, and further effects of Gn......RHa on daily mood. RESULTS: GnRHa induced an increase in simple reaction time (p=0.03) and more pronounced fluctuations in daily self-reported mood in a manner dependent on baseline mood (p=0.003). Verbal affective memory recall, overall self-perceived mental distress, and serotonin transporter binding were...

QT Prolongation due to Graves’ Disease

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Zain Kulairi

2017-01-01

Full Text Available Hyperthyroidism is a highly prevalent disease affecting over 4 million people in the US. The disease is associated with many cardiac complications including atrial fibrillation and also less commonly with ventricular tachycardia and fibrillation. Many cardiac pathologies have been extensively studied; however, the relationship between hyperthyroidism and rate of ventricular repolarization manifesting as a prolonged QTc interval is not well known. Prolonged QTc interval regardless of thyroid status is a risk factor for cardiovascular mortality and life-threatening ventricular arrhythmia. The mechanism regarding the prolongation of the QT interval in a hyperthyroid patient has not been extensively investigated although its clinical implications are relevant. Herein, we describe a case of prolonged QTc in a patient who presented with signs of hyperthyroidism that was corrected with return to euthyroid status.

Mix and Inject: Reaction Initiation by Diffusion for Time-Resolved Macromolecular Crystallography

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Marius Schmidt

2013-01-01

Full Text Available Time-resolved macromolecular crystallography unifies structure determination with chemical kinetics, since the structures of transient states and chemical and kinetic mechanisms can be determined simultaneously from the same data. To start a reaction in an enzyme, typically, an initially inactive substrate present in the crystal is activated. This has particular disadvantages that are circumvented when active substrate is directly provided by diffusion. However, then it is prohibitive to use macroscopic crystals because diffusion times become too long. With small micro- and nanocrystals diffusion times are adequately short for most enzymes and the reaction can be swiftly initiated. We demonstrate here that a time-resolved crystallographic experiment becomes feasible by mixing substrate with enzyme nanocrystals which are subsequently injected into the X-ray beam of a pulsed X-ray source.

Intraindividual variability in reaction time predicts cognitive outcomes 5 years later.

Science.gov (United States)

Bielak, Allison A M; Hultsch, David F; Strauss, Esther; Macdonald, Stuart W S; Hunter, Michael A

2010-11-01

Building on results suggesting that intraindividual variability in reaction time (inconsistency) is highly sensitive to even subtle changes in cognitive ability, this study addressed the capacity of inconsistency to predict change in cognitive status (i.e., cognitive impairment, no dementia [CIND] classification) and attrition 5 years later. Two hundred twelve community-dwelling older adults, initially aged 64-92 years, remained in the study after 5 years. Inconsistency was calculated from baseline reaction time performance. Participants were assigned to groups on the basis of their fluctuations in CIND classification over time. Logistic and Cox regressions were used. Baseline inconsistency significantly distinguished among those who remained or transitioned into CIND over the 5 years and those who were consistently intact (e.g., stable intact vs. stable CIND, Wald (1) = 7.91, p < .01, Exp(β) = 1.49). Average level of inconsistency over time was also predictive of study attrition, for example, Wald (1) = 11.31, p < .01, Exp(β) = 1.24. For both outcomes, greater inconsistency was associated with a greater likelihood of being in a maladaptive group 5 years later. Variability based on moderately cognitively challenging tasks appeared to be particularly sensitive to longitudinal changes in cognitive ability. Mean rate of responding was a comparable predictor of change in most instances, but individuals were at greater relative risk of being in a maladaptive outcome group if they were more inconsistent rather than if they were slower in responding. Implications for the potential utility of intraindividual variability in reaction time as an early marker of cognitive decline are discussed. (c) 2010 APA, all rights reserved

Exhaustion from prolonged gambling

Directory of Open Access Journals (Sweden)

Fatimah Lateef

2013-01-01

Full Text Available Complaints of fatigue and physical exhaustion are frequently seen in the acute medical setting, especially amongst athletes, army recruits and persons involved in strenuous and exertional physical activities. Stress-induced exhaustion, on the other hand, is less often seen, but can present with very similar symptoms to physical exhaustion. Recently, three patients were seen at the Department of Emergency Medicine, presenting with exhaustion from prolonged involvement in gambling activities. The cases serve to highlight some of the physical consequences of prolonged gambling.

The design of an energy harvesting device for prolonging the working time of DC equipment

Science.gov (United States)

Wen, Yayuan; Deng, Huaxia; Zhang, Jin; Yu, Liandong

2016-01-01

Energy harvesting (EH) derives from the idea of converting the ambient energy into electric energy, which can solve the problem of DC supply for some electronic equipment. PZT is a typical piezoelectric material of inorganic, which has been developed as EH devices to transfer ambient vibration energy into electric energy. However, these PZT devices require relatively violent excitation, and easy to be fatigue fracture under the resonance condition. In this paper, PVDF, which is a kind of soft piezoelectric polymer, is adopted for developing transducer. The PVDF devices are flexible and have longer life time than PZT devices under the harmonic environment. The EH researches are mainly focused on the development of energy transfer efficiency either by the mechanical structure of transducer or the improvement of circuit. However, the practicality and stability of the EH devices are important in the practical engineering applications. In this paper, a charge amplifier is introduced in the circuit in order to guarantee the stability of the battery charging under small ambient vibration conditions. The model of the mechanical structure of PVDF and the electric performance of circuit are developed. The experimental results and simulation show that the stability of battery charging is improved and the working time of DC equipment is prolonged.

An analytic algorithm for the space-time fractional reaction-diffusion equation

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M. G. Brikaa

2015-11-01

Full Text Available In this paper, we solve the space-time fractional reaction-diffusion equation by the fractional homotopy analysis method. Solutions of different examples of the reaction term will be computed and investigated. The approximation solutions of the studied models will be put in the form of convergent series to be easily computed and simulated. Comparison with the approximation solution of the classical case of the studied modeled with their approximation errors will also be studied.

Striatal lesions produce distinctive impairments in reaction time performance in two different operant chambers.

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Brasted, P J; Döbrössy, M D; Robbins, T W; Dunnett, S B

1998-08-01

The dorsal striatum plays a crucial role in mediating voluntary movement. Excitotoxic striatal lesions in rats have previously been shown to impair the initiation but not the execution of movement in a choice reaction time task in an automated lateralised nose-poke apparatus (the "nine-hole box"). Conversely, when a conceptually similar reaction time task has been applied in a conventional operant chamber (or "Skinner box"), striatal lesions have been seen to impair the execution rather than the initiation of the lateralised movement. The present study was undertaken to compare directly these two results by training the same group of rats to perform a choice reaction time task in the two chambers and then comparing the effects of a unilateral excitotoxic striatal lesion in both chambers in parallel. Particular attention was paid to adopting similar parameters and contingencies in the control of the task in the two test chambers. After striatal lesions, the rats showed predominantly contralateral impairments in both tasks. However, they showed a deficit in reaction time in the nine-hole box but an apparent deficit in response execution in the Skinner box. This finding confirms the previous studies and indicates that differences in outcome are not simply attributable to procedural differences in the lesions, training conditions or tasks parameters. Rather, the pattern of reaction time deficit after striatal lesions depends critically on the apparatus used and the precise response requirements for each task.

Opposite effects of sleep deprivation on the continuous reaction times in patients with liver cirrhosis and normal persons.

Science.gov (United States)

Lauridsen, Mette Munk; Frøjk, Jesper; de Muckadell, Ove B Schaffalitzky; Vilstrup, Hendrik

2014-09-01

The continuous reaction times (CRT) method describes arousal functions. Reaction time instability in a patient with liver disease indicates covert hepatic encephalopathy (cHE). The effects of sleep deprivation are unknown although cirrhosis patients frequently suffer from sleep disorders. The aim of this study was to determine if sleep deprivation influences the CRT test. Eighteen cirrhosis patients and 27 healthy persons were tested when rested and after one night's sleep deprivation. The patients filled out validated sleep quality questionnaires. Seven patients (38%) had unstable reaction times (a CRTindex sleep that was not related to their CRT tests before or after the sleep deprivation. In the healthy participants, the sleep deprivation slowed their reaction times by 11% (p sleep deprivation normalized or improved the reaction time stability of the patients with a CRTindex below 1.9 and had no effect in the patients with a CRTindex above 1.9. There was no relation between reported sleep quality and reaction time results. Thus, in cirrhosis patients, sleep disturbances do not lead to 'falsely' slowed and unstable reaction times. In contrast, the acute sleep deprivation slowed and destabilized the reaction times of the healthy participants. This may have negative consequences for decision-making.

Is Reaction Time Variability in ADHD Mainly at Low Frequencies?

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Karalunas, Sarah L.; Huang-Pollock, Cynthia L.; Nigg, Joel T.

2013-01-01

Background: Intraindividual variability in reaction times (RT variability) has garnered increasing interest as an indicator of cognitive and neurobiological dysfunction in children with attention deficit hyperactivity disorder (ADHD). Recent theory and research has emphasized specific low-frequency patterns of RT variability. However, whether…

Prolonged ventilation post cardiac surgery - tips and pitfalls of the prediction game

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Knapik Piotr

2011-11-01

Full Text Available Abstract Background Few available models aim to identify patients at risk of prolonged ventilation after cardiac surgery. We compared prediction models developed in ICU in two adjacent periods of time, when significant changes were observed both in population characteristics and the perioperative management. Methods We performed a retrospective review of two cohorts of patients in our department in two subsequent time periods (July 2007 - December 2008, n = 2165; January 2009 - July 2010, n = 2192. The study was approved by the Institutional Ethics Committee and the individual patient consent was not required. Patients were divided with regard to ventilation time of more or less than 48 hours. Preoperative and procedure-related variables for prolonged ventilation were identified and multivariate logistic regression analysis was performed separately for each cohort. Results Most recent patients were older, with more co-morbidities, more frequently undergoing off-pump surgery. At the beginning of 2009 we also changed the technique of postoperative ventilation. Percentage of patients with prolonged ventilation decreased from 5.7% to 2.4% (p Conclusions Prediction models for postoperative ventilation should be regularly updated, particularly when major changes are noted in patients' demographics and surgical or anaesthetic technique.

Safety information on QT-interval prolongation

DEFF Research Database (Denmark)

Warnier, Miriam J; Holtkamp, Frank A; Rutten, Frans H

2014-01-01

Prolongation of the QT interval can predispose to fatal ventricular arrhythmias. Differences in QT-labeling language can result in miscommunication and suboptimal risk mitigation. We systematically compared the phraseology used to communicate on QT-prolonging properties of 144 drugs newly approve...

Large-time behavior of solutions to a reaction-diffusion system with distributed microstructure

NARCIS (Netherlands)

Muntean, A.

2009-01-01

Abstract We study the large-time behavior of a class of reaction-diffusion systems with constant distributed microstructure arising when modeling diffusion and reaction in structured porous media. The main result of this Note is the following: As t ¿ 8 the macroscopic concentration vanishes, while

Optimism in prolonged grief and depression following loss: A three-wave longitudinal study.

Science.gov (United States)

Boelen, Paul A

2015-06-30

There is considerable evidence that optimism, the predisposition to have generalized favorable expectancies for the future, is associated with numerous desirable outcomes. Few studies have examined the association of optimism with emotional distress following the death of a loved one. Doing so is important, because optimism may be an important target for interventions for post-loss psychopathology. In the current study, we examined the degree to which optimism, assessed in the first year post-loss (Time 1, T1), was associated with symptom levels of prolonged grief and depression six months (Time 2, T2) and fifteen months (Time 3, T3) later, controlling for baseline symptoms and also taking into account positive automatic cognitions at T1. Findings showed that higher optimism at T1 was associated with lower concurrent prolonged grief and depression severity. Higher optimism at T1 was also inversely related with depression symptom severity at T2 and T3, but not prolonged grief severity at T2 and T3. Implications of these findings are discussed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

K X-rays and nuclear reaction times in the deep inelastic reactions U+U and U+Pb at 7.5 MeV/amu

International Nuclear Information System (INIS)

Stoller, C.

1985-01-01

The K-shell ionisation probability of the heavy reaction products emerging from binary deep inelastic collisions of U + U and U + Pb at 7.5 MeV/amu has been measured as a function of the total kinetic energy loss - Q. After subtraction of the ionisation probability due to internal conversion of γ-rays, a strongly Q-dependent Psub(K) is found, in agreement with theoretical predictions relating the change in ionisation probability to the nuclear sticking time. The deduced nuclear reaction times are in qualitative agreement with predictions from nuclear models of deep inelastic reactions. (orig.)

In vivo assessment of catheter positioning accuracy and prolonged irradiation time on liver tolerance dose after single-fraction 192Ir high-dose-rate brachytherapy

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Kropf Siegfried

2011-09-01

Full Text Available Abstract Background To assess brachytherapy catheter positioning accuracy and to evaluate the effects of prolonged irradiation time on the tolerance dose of normal liver parenchyma following single-fraction irradiation with 192 Ir. Materials and methods Fifty patients with 76 malignant liver tumors treated by computed tomography (CT-guided high-dose-rate brachytherapy (HDR-BT were included in the study. The prescribed radiation dose was delivered by 1 - 11 catheters with exposure times in the range of 844 - 4432 seconds. Magnetic resonance imaging (MRI datasets for assessing irradiation effects on normal liver tissue, edema, and hepatocyte dysfunction, obtained 6 and 12 weeks after HDR-BT, were merged with 3D dosimetry data. The isodose of the treatment plan covering the same volume as the irradiation effect was taken as a surrogate for the liver tissue tolerance dose. Catheter positioning accuracy was assessed by calculating the shift between the 3D center coordinates of the irradiation effect volume and the tolerance dose volume for 38 irradiation effects in 30 patients induced by catheters implanted in nearly parallel arrangement. Effects of prolonged irradiation were assessed in areas where the irradiation effect volume and tolerance dose volume did not overlap (mismatch areas by using a catheter contribution index. This index was calculated for 48 irradiation effects induced by at least two catheters in 44 patients. Results Positioning accuracy of the brachytherapy catheters was 5-6 mm. The orthogonal and axial shifts between the center coordinates of the irradiation effect volume and the tolerance dose volume in relation to the direction vector of catheter implantation were highly correlated and in first approximation identically in the T1-w and T2-w MRI sequences (p = 0.003 and p p = 0.001 and p = 0.004, respectively. There was a significant shift of the irradiation effect towards the catheter entry site compared with the planned dose

Secular slowing auditory simple reaction time in Sweden (1959-1985

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Guy Madison

2016-08-01

Full Text Available There are indications that simple reaction time might have slowed in Western countries, based on both cohort- and multi-study comparisons. A possible limitation of the latter method in particular is measurement error stemming from methods variance, which results from the fact that instruments and experimental conditions change over time and between studies. We therefore set out to measure the simple auditory reaction time (SRT of 7,081 individuals (2,997 males and 4,084 females born in Sweden 1959-1985 (subjects were aged between 27 and 54 years at time of measurement. Depending on cut-offs and adjustment for ageing related slowing on SRT, the data suggest that SRT has increased between 3 and 16 ms in the 27 birth years covered in the present sample. The slowing is unlikely to be explained by attrition, as evaluated by comparing the general intelligence × birth-year interactions and standard deviations for both male participants and dropouts, utilizing military conscript cognitive ability data. The present result is consistent with previous studies employing alternative methods, and may result from several synergistic factors, such as possible recent micro-evolutionary trends favouring lower g in Sweden and the effects of industrially produced neurotoxic substances on peripheral nerve conduction velocity.

Interference between postural control and spatial vs. non-spatial auditory reaction time tasks in older adults.

Science.gov (United States)

Fuhrman, Susan I; Redfern, Mark S; Jennings, J Richard; Furman, Joseph M

2015-01-01

This study investigated whether spatial aspects of an information processing task influence dual-task interference. Two groups (Older/Young) of healthy adults participated in dual-task experiments. Two auditory information processing tasks included a frequency discrimination choice reaction time task (non-spatial task) and a lateralization choice reaction time task (spatial task). Postural tasks included combinations of standing with eyes open or eyes closed on either a fixed floor or a sway-referenced floor. Reaction times and postural sway via center of pressure were recorded. Baseline measures of reaction time and sway were subtracted from the corresponding dual-task results to calculate reaction time task costs and postural task costs. Reaction time task cost increased with eye closure (p = 0.01), sway-referenced flooring (p vision x age interaction indicated that older subjects had a significant vision X task interaction whereas young subjects did not. However, when analyzed by age group, the young group showed minimal differences in interference for the spatial and non-spatial tasks with eyes open, but showed increased interference on the spatial relative to non-spatial task with eyes closed. On the contrary, older subjects demonstrated increased interference on the spatial relative to the non-spatial task with eyes open, but not with eyes closed. These findings suggest that visual-spatial interference may occur in older subjects when vision is used to maintain posture.

Genetic influence on prolonged gestation

DEFF Research Database (Denmark)

Laursen, Maja; Bille, Camilla; Olesen, Annette Wind

2004-01-01

OBJECTIVE: The purpose of this study was to test a possible genetic component to prolonged gestation. STUDY DESIGN: The gestational duration of single, first pregnancies by both female and male twins was obtained by linking the Danish Twin Registry, The Danish Civil Registration System, and the D...... factors. CONCLUSION: Maternal genes influence prolonged gestation. However, a substantial paternal genetic influence through the fetus was not found....

Stress reactions involving the pars interarticularis in young athletes

Energy Technology Data Exchange (ETDEWEB)

Jackson, D.W.; Wiltse, L.L.; Dingeman, R.D.; Hayes, M.

A stress reaction involving the pars interarticularis of the lumbar spine was confirmed in seven young athletes with a positive technetium pyrophosphate bone scan. No pars defects were detectable on their lumbosacral roentgenograms, which included oblique views. The return to normal levels of radioactive uptake on repeat bone scans correlated closely with their clinical course. If the bony reaction is recognized early, it may heal at a subroentgenographic level and prevent the development of lumbar spondylolysis. These early lesions usually show unilateral increased uptake at one lumbar level on the bone scan and, initially, the athlete localizes the pain to the corresponding unilateral lumbar paraspinous area. The ''one-legged hyperextension test'' is positive on the ipsilateral side and aggravates the pain. Treatment consists of avoiding the aggravating activities and resting. The average time for return to pain-free competition was 7.3 months. These developing defects may be the source of considerable prolonged disability in the young athlete, particularly if undiagnosed and untreated.

Stress reactions involving the pars interarticularis in young athletes

International Nuclear Information System (INIS)

Jackson, D.W.; Wiltse, L.L.; Dingeman, R.D.; Hayes, M.

1981-01-01

A stress reaction involving the pars interarticularis of the lumbar spine was confirmed in seven young athletes with a positive technetium pyrophosphate bone scan. No pars defects were detectable on their lumbosacral roentgenograms, which included oblique views. The return to normal levels of radioactive uptake on repeat bone scans correlated closely with their clinical course. If the bony reaction is recognized early, it may heal at a subroentgenographic level and prevent the development of lumbar spondylolysis. These early lesions usually show unilateral increased uptake at one lumbar level on the bone scan and, initially, the athlete localizes the pain to the corresponding unilateral lumbar paraspinous area. The ''one-legged hyperextension test'' is positive on the ipsilateral side and aggravates the pain. Treatment consists of avoiding the aggravating activities and resting. The average time for return to pain-free competition was 7.3 months. These developing defects may be the source of considerable prolonged disability in the young athlete, particularly if undiagnosed and untreated

An investigation of leg and trunk strength and reaction times of hard-style martial arts practitioners.

Science.gov (United States)

Donovan, Oliver O; Cheung, Jeanette; Catley, Maria; McGregor, Alison H; Strutton, Paul H

2006-01-01

The purpose of this study was to investigate trunk and knee strength in practitioners of hard-style martial arts. An additional objective was to examine reaction times in these participants by measuring simple reaction times (SRT), choice reaction times (CRT) and movement times (MT). Thirteen high-level martial artists and twelve sedentary participants were tested under isokinetic and isometric conditions on an isokinetic dynamometer. Response and movement times were also measured in response to simple and choice auditory cues. Results indicated that the martial arts group generated a greater body-weight adjusted peak torque with both legs at all speeds during isokinetic extension and flexion, and in isometric extension but not flexion. In isokinetic and isometric trunk flexion and extension, martial artists tended to have higher peak torques than controls, but they were not significantly different (p > 0.05). During the SRT and CRT tasks the martial artists were no quicker in lifting their hand off a button in response to the stimulus [reaction time (RT)] but were significantly faster in moving to press another button [movement time (MT)]. In conclusion, the results reveal that training in a martial art increases the strength of both the flexors and extensors of the leg. Furthermore, they have faster movement times to auditory stimuli. These results are consistent with the physical aspects of the martial arts. Key PointsMartial artists undertaking hard-style martial arts have greater strength in their knee flexor and extensor muscles as tested under isokinetic testing. Under isometric testing conditions they have stronger knee extensors only.The trunk musculature is generally higher under both conditions of testing in the martial artists, although not significantly.The total reaction times of the martial artists to an auditory stimulus were significantly faster than the control participants. When analysed further it was revealed that the decrease in reaction time

Thin liquid films with time-dependent chemical reactions sheared by an ambient gas flow

Science.gov (United States)

Bender, Achim; Stephan, Peter; Gambaryan-Roisman, Tatiana

2017-08-01

Chemical reactions in thin liquid films are found in many industrial applications, e.g., in combustion chambers of internal combustion engines where a fuel film can develop on pistons or cylinder walls. The reactions within the film and the turbulent outer gas flow influence film stability and lead to film breakup, which in turn can lead to deposit formation. In this work we examine the evolution and stability of a thin liquid film in the presence of a first-order chemical reaction and under the influence of a turbulent gas flow. Long-wave theory with a double perturbation analysis is used to reduce the complexity of the problem and obtain an evolution equation for the film thickness. The chemical reaction is assumed to be slow compared to film evolution and the amount of reactant in the film is limited, which means that the reaction rate decreases with time as the reactant is consumed. A linear stability analysis is performed to identify the influence of reaction parameters, material properties, and environmental conditions on the film stability limits. Results indicate that exothermic reactions have a stabilizing effect whereas endothermic reactions destabilize the film and can lead to rupture. It is shown that an initially unstable film can become stable with time as the reaction rate decreases. The shearing of the film by the external gas flow leads to the appearance of traveling waves. The shear stress magnitude has a nonmonotonic influence on film stability.

Chemical interesterification of soybean oil and fully hydrogenated soybean oil: Influence of the reaction time

International Nuclear Information System (INIS)

Ribeiro, Ana Paula Badan; Masuchi, Monise Helen; Grimaldi, Renato; Goncalves, Lireny Aparecida Guaraldo

2009-01-01

Chemical interesterification is an important alternative to produce zero trans fats. In practice, however, excessive reaction times are used to ensure complete randomization. This work evaluated the influence of the reaction time on the interesterification of soybean oil/fully hydrogenated soybean oil blend, carried out in the following conditions: 100 deg C, 500 rpm stirring speed, 0.4% (w/w) sodium methoxide catalyst. The triacylglycerol composition, solid fat content and melting point analysis showed that the reaction was very fast, reaching the equilibrium within 5 min. This result suggests the interesterification can be performed in substantially lower times, with reduction in process costs. (author)

Analysis of agility, reaction time and balance variables at badminton players aged 9-14 years

Directory of Open Access Journals (Sweden)

Seydi Ahmet Ağaoğlu

2017-12-01

Full Text Available Aim: The aim of this study was investigated agility, static and dynamic balance and reaction time variables of badminton players aged between 9-14 and relate with among variables. Material and Methods: In Samsun, 19 males (sport age, 3.42±1.64 years and 12 females (3.00±1.28 years active badminton players were voluntarily participated in who are in 9-14 ages range. Agility was measured by “T” test, CSMI-Tecnobody Pk-252 isokinetic balance system measuring instrument was used to test static balance and dynamic balance and Mozart Lafayette reaction measuring instrument was used to test visual and auditory reaction times of players. Spearman correlation analysis was applied so as to correlation analysis. The level of significance was taken as p<0.05. Results: For female athletes, a positive relation was determined between the agility and the perimeter (mm used (r=0.727; p<0.01 through the static balance measure double foot and eyes are open. For male athletes, a positive relation was determined between the visual reaction time and the perimeter (mm used (r=0.725; p<0.01 through the static balance measure dominant foot and eyes are open. For male and female athletes were not found any correlation between reaction time and dynamic balance. Conclusion: It was determined that audio (ears and visual (eyes reaction time was effective on balance. While badminton players are closed eyes, audio sensors are more influence on balance test through measure dominant foot.

Risk factors for QTc interval prolongation

NARCIS (Netherlands)

Heemskerk, Charlotte P.M.; Pereboom, Marieke; van Stralen, Karlijn; Berger, Florine A.; van den Bemt, Patricia M.L.A.; Kuijper, Aaf F.M.; van der Hoeven, Ruud T M; Mantel-Teeuwisse, Aukje K.; Becker, Matthijs L

2018-01-01

Purpose: Prolongation of the QTc interval may result in Torsade de Pointes, a ventricular arrhythmia. Numerous risk factors for QTc interval prolongation have been described, including the use of certain drugs. In clinical practice, there is much debate about the management of the risks involved. In

Sidestep and crossover lower limb kinematics during a prolonged sport-like agility test.

Science.gov (United States)

Potter, Danielle; Reidinger, Kellie; Szymialowicz, Rebecca; Martin, Thomas; Dione, Donald; Feinn, Richard; Wallace, David; Garbalosa, Juan C

2014-10-01

Non-contact anterior cruciate ligament (ACL) injuries in athletes occur more often towards the end of athletic competitions. However, the exact mechanisms of how prolonged activity increases the risk for ACL injuries are not clear. To determine the effect of prolonged activity on the hip and knee kinematics observed during self-selected cutting maneuvers performed in a timed agility test. Nineteen female Division I collegiate soccer players completed a self-selected cutting agility test until they were unable to meet a set performance time (one standard deviation of the average baseline trial). Using the 3D dimensional coordinate data the cut type was identified by the principle investigators. The 3D hip and knee angles at 32ms post heel strike were analyzed using a two-factor, linear mixed model to assess the effect of prolonged activity and cut type on the recorded mean hip and knee angles. Athletes performed either sidestep or crossover cuts. An effect of cut type and prolonged activity was seen at the hip and knee. During the prolonged activity trials, the knee was relatively more adducted and both the hip and knee were less flexed than during the baseline trials regardless of cut type. Regardless of activity status, during sidestep cuts, the hip was more internally rotated and abducted, and less flexed than during crossover cuts while the knee was more abducted and less flexed during the sidestep than crossover cuts. During a sport-like agility test, prolonged activity appears to predispose the athlete to position their knee in a more extended and abducted posture and their hip in a more extended posture. This position has been suggested to place stress on the ACL and potentially increase the risk for injury. Clinicians may want to consider the effects of prolonged activity on biomechanical risk factors for sustaining ACL injuries in the design of intervention strategies to prevent ACL injuries. Level 4.

Changes of the rats’ heart rate variability caused by chlorpromazine modulation of central noradrenergic neurotransmission during prolonged stress

Directory of Open Access Journals (Sweden)

O. Z. Мelnikova

2012-03-01

Full Text Available It’s established that under the prolonged stress there were changes of geometric and spectral indices of the rats’ heart rate variability (HRV, manifestations of which depended on duration of stressful factors acting and represented the stress reaction development from the stage of anxiety to the exhaustion phase. Application of chlorpromazine at the beginning and against the background of stress blocked the central alpha adrenoceptors and contributed to renewal of the most HRV indices into the limits of control values at the end of experiment. The results of research show that the modulation of functional state of central noradrenergic system plays a great role in the changes of HRV during prolonged stress.

Does listening to music with an audio ski helmet impair reaction time to peripheral stimuli?

Science.gov (United States)

Ruedl, G; Pocecco, E; Wolf, M; Schöpf, S; Burtscher, M; Kopp, M

2012-12-01

With the recent worldwide increase in ski helmet use, new market trends are developing, including audio helmets for listening to music while skiing or snowboarding. The aim of this study was to evaluate whether listening to music with an audio ski helmet impairs reaction time to peripheral stimuli. A within-subjects design study using the Compensatory-Tracking-Test was performed on 65 subjects (36 males and 29 females) who had a mean age of 23.3 ± 3.9 years. Using repeated measures analysis of variance, we found significant differences in reaction times between the 4 test conditions (p=0.039). The lowest mean reaction time (± SE) was measured for helmet use while listening to music (507.9 ± 13.2 ms), which was not different from helmet use alone (514.6 ± 12.5 ms) (p=0.528). However, compared to helmet use while listening to music, reaction time was significantly longer for helmet and ski goggles used together (535.8 ± 14.2 ms, p=0.005), with a similar trend for helmet and ski goggles used together while listening to music (526.9 ± 13.8 ms) (p=0.094). In conclusion, listening to music with an audio ski helmet did not increase mean reaction time to peripheral stimuli in a laboratory setting. © Georg Thieme Verlag KG Stuttgart · New York.

Time-resolved imaging of purely valence-electron dynamics during a chemical reaction

DEFF Research Database (Denmark)

Hockett, Paul; Bisgaard, Christer Z.; Clarkin, Owen J.

2011-01-01

Chemical reactions are manifestations of the dynamics of molecular valence electrons and their couplings to atomic motions. Emerging methods in attosecond science can probe purely electronic dynamics in atomic and molecular systems(1-6). By contrast, time-resolved structural-dynamics methods...... such as electron(7-10) or X-ray diffraction(11) and X-ray absorption(12) yield complementary information about the atomic motions. Time-resolved methods that are directly sensitive to both valence-electron dynamics and atomic motions include photoelectron spectroscopy(13-15) and high-harmonic generation(16......,17): in both cases, this sensitivity derives from the ionization-matrix element(18,19). Here we demonstrate a time-resolved molecular-frame photoelectron-angular-distribution (TRMFPAD) method for imaging the purely valence-electron dynamics during a chemical reaction. Specifically, the TRMFPADs measured during...

The Influence of Different Performance Level of Fencers on Simple and Choice Reaction Time

Directory of Open Access Journals (Sweden)

Štefan Balkó

2016-09-01

Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n4p391   In many sport disciplines reaction time plays a key role in the sport performance. It is good to point out for example ball games or fighting sports (fencing, karate etc.. The research is focused on detection of the differences in the simple and choice reaction time during visual stimulation among elite, sub-elite fencers and beginners. For the measurement a Fitrosword device and the SWORD software were used. An additional stimulus was added during measuring which should increase the overall number of stimuli, but shouldn’t force fencer to any reaction whatsoever. The results from presented study can be compared with Hicks law. The next focus of the study was to identify the difference in reaction time during two different movement tasks with different complexity movement requirements. The research was built up on a hypothesis that the results will differ among different performance groups of fencers. The difference however was overt among beginners and elite fencers (p = 0.0088, d = 0.5 in reaction time during different movement tasks (direct hit vs. lunge. The results of this research could be useful to trainers for training process organisation and increase the effectivity of muscle coordination during several movements in fencing.

Effect of age, gender and body mass index on visual and auditory reaction times in Indian population.

Science.gov (United States)

Nikam, Lalita H; Gadkari, Jayshree V

2012-01-01

The effect of Age. Gender and Body Mass Index (BMI) on the Visual (VRT) and Auditory reaction time (ART) was studied in 30 males and 30 females in the age group of 18-20 years along with 30 males and 30 females in the age group of 65-75 years. Statistical analysis of the data by one-way ANOVA and post-hoc by Tukey-HSD test showed that BMI, VRT and ART were significantly higher in old than young individuals. Females had higher BMI and longer reaction times than males. There was significant positive correlation between BMI and reaction times (VRT and ART) in both males and females by Pearson correlation analysis. Older individuals should be more careful and vigilant about the injuries and falls due to increased reaction time. Longer reaction times and higher BMI in females could be attributed to fluid and salt retention due to female sex hormones affecting sensorimotor co-ordination.

Intraindividual Stepping Reaction Time Variability Predicts Falls in Older Adults With Mild Cognitive Impairment

OpenAIRE

Bunce, D; Haynes, BI; Lord, SR; Gschwind, YJ; Kochan, NA; Reppermund, S; Brodaty, H; Sachdev, PS; Delbaere, K

2017-01-01

Background: Reaction time measures have considerable potential to aid neuropsychological assessment in a variety of health care settings. One such measure, the intraindividual reaction time variability (IIV), is of particular interest as it is thought to reflect neurobiological disturbance. IIV is associated with a variety of age-related neurological disorders, as well as gait impairment and future falls in older adults. However, although persons diagnosed with Mild Cognitive Impairment (MCI)...

Intermedin A, a New Labdane Diterpene Isolated from Alpinia intermedia, Prolonged the Survival Time of P-388D1 Tumor-Bearing CDF1 Mice.

Science.gov (United States)

Chen, Lih-Geeng; Su, Pei-Jung; Tsai, Po-Wei; Yang, Ling-Ling; Wang, Ching-Chiung

2017-01-01

Eight ethanolic extracts of indigenous Taiwanese plants of the genus Alpinia were tested for tumor cytotoxicity against AGS, Hep G2, HeLa, KB, and HL-60 cells. Among the 50 % and 95 % EtOH extracts of eight Alpinia species, the cytotoxic effects of Alpinia intermedia leaves were the strongest. When the leaf extract of A. intermedia was partitioned using n -hexane and aqueous solvents, the n -hexane layer showed a greater cytotoxic effect and could prolong the survival time of P-388D 1 tumor-bearing CDF1 mice. Two new labdane diterpene derivatives, intermedin A ( 1 ) and intermedin B ( 2 ), and coronarin E ( 3 ) were isolated from the n -hexane layer of A. intermedia . Intermedin A induced apoptosis in HL-60 cells at 30 µg/mL and significantly prolonged the survival time of P-388D 1 tumor-bearing CDF 1 mice by 48.7 % at 20 mg/kg of body weight. We suggest that intermedin A is a major compound of A. intermedia and has a cytotoxic effect on HL-60 and P-388D 1 cells. Georg Thieme Verlag KG Stuttgart · New York.

The influence of a consumer-wearable activity tracker on sedentary time and prolonged sedentary bouts: secondary analysis of a randomized controlled trial.

Science.gov (United States)

Sloan, Robert A; Kim, Youngdeok; Sahasranaman, Aarti; Müller-Riemenschneider, Falk; Biddle, Stuart J H; Finkelstein, Eric A

2018-03-22

A recent meta-analysis surmised pedometers were a useful panacea to independently reduce sedentary time (ST). To further test and expand on this deduction, we analyzed the ability of a consumer-wearable activity tracker to reduce ST and prolonged sedentary bouts (PSB). We originally conducted a 12-month randomized control trial where 800 employees from 13 organizations were assigned to control, activity tracker, or one of two activity tracker plus incentive groups designed to increase step count. The primary outcome was accelerometer measured moderate-to-vigorous physical activity. We conducted a secondary analysis on accelerometer measured daily ST and PSB bouts. A general linear mixed model was used to examine changes in ST and prolonged sedentary bouts, followed by between-group pairwise comparisons. Regression analyses were conducted to examine the association of changes in step counts with ST and PSB. The changes in ST and PSB were not statistically significant and not different between the groups (P consumer-wearable activity trackers as a means to reduce sedentary behavior. Trial registration NCT01855776 Registered: August 8, 2012.

Preferential processing of tactile events under conditions of divided attention: Effects of divided attention on reaction time

OpenAIRE

Hanson, James V. M.; Whitaker, David; Heron, James

2009-01-01

Differences in transduction and transmission latencies of visual, auditory and tactile events cause corresponding differences in simple reaction time. As reaction time is usually measured in unimodal blocks, it is unclear whether such latency differences also apply when observers monitor multiple sensory channels. We investigate this by comparing reaction time when attention is focussed on a single modality, and when attention is divided between multiple modalities. Results show that tactile ...

Diet-consumer nitrogen isotope fractionation for prolonged fasting arthropods.

Science.gov (United States)

Mizota, Chitoshi; Yamanaka, Toshiro

2011-12-01

Nitrogen acquisition for cellular metabolism during diapause is a primary concern for herbivorous arthropods. Analyses of naturally occurring stable isotopes of nitrogen help elucidate the mechanism. Relevant articles have cited (58 times up to mid-June 2011) anomalously elevated δ(15)N (per mil deviation of (15)N/(14)N, relative to atmospheric nitrogen=0 ‰) values (diet-consumer nitrogen isotope fractionation; up to 12 ‰) for a prolonged fasting raspberry beetle (Byturus tomentosus Degeer (Coleoptera: Byturidae)), which feeds on red raspberries (Rubus idaeus: δ(15)N= ~ +2 ‰). Biologists have hypothesised that extensive recycling of amino acid nitrogen is responsible for the prolonged fasting. Since this hypothesis was proposed in 1995, scientists have integrated biochemical and molecular knowledge to support the mechanism of prolonged diapausing of animals. To test the validity of the recycling hypothesis, we analysed tissue nitrogen isotope ratios for four Japanese arthropods: the shield bug Parastrachia japonensis Scott (Hemiptera: Cydnidae), the burrower bug Canthophorus niveimarginatus Scott (Hemiptera: Cydnidae), leaf beetle Gastrophysa atrocyanea Motschulsky (Coleoptera: Chrysomelidae) and the Japanese oak silkworm Antheraea yamamai (Lepidoptera: Saturniidae), all of which fast for more than 6 months as part of their life-history strategy. Resulting diet-consumer nitrogen isotope discrimination during fasting ranged from 0 to 7‰, as in many commonly known terrestrial arthropods. We conclude that prolonged fasting of arthropods does not always result in anomalous diet-consumer nitrogen isotope fractionation, since the recycling process is closed or nearly closed with respect to nitrogen isotopes.

Prolongation of islet allograft survival

International Nuclear Information System (INIS)

Lacy, P.E.; Davie, J.M.; Finke, E.H.; Scharp, D.W.

1979-01-01

Pretreatment of donor rats with irradiation and silica followed by in vitro culture of the islets for 1 to 2 days prolonged survival of allografts across a minor histocompatibility barrier if hand-picked, clean islets were used for transplantation. Pretreatment of donor rats with irradiation and silica in conjunction with a single injection of antilymphocyte serum (ALS) into the recipient produced a prolongation of survival of hand-picked islets transplanted across a major histocompatibility barrier

Immediate effects of different treatments for the wrist joints of subdominant hands, using electromechanical reaction time.

Science.gov (United States)

Hu, Chunying; Huang, Qiuchen; Yu, Lili; Zhou, Yue; Gu, Rui; Cui, Yao; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

2016-08-01

[Purpose] The aim of this study was to examine the immediate effects of muscle strength training and neuromuscular joint facilitation distal resistance training on wrist joints by using electromechanical reaction time. [Subjects and Methods] The subjects were 12 healthy young people (24.2 ± 3.1 years, 169.7 ± 6.5 cm, 65.3 ± 12.6 kg). Two kinds of isotonic contraction techniques were applied on the wrist joint: the wrist joint extension muscle strength training and the wrist joint extension pattern of neuromuscular joint facilitation. The electromechanical reaction time, premotor time, and motor time of the left upper limb were measured before and after each intervention session of muscle strength training and neuromuscular joint facilitation. [Results] The neuromuscular joint facilitation group showed significant shortening of the electromechanical reaction time and motor time after the intervention. [Conclusion] These results suggest that the electromechanical reaction time and motor time of the wrist joint can be improved by neuromuscular joint facilitation together with proximal resistance training, which can be used as a new form of exercise for improving the functions of subdominant hand wrist joints.

Prolonged pain and disability are common after rib fractures.

Science.gov (United States)

Fabricant, Loic; Ham, Bruce; Mullins, Richard; Mayberry, John

2013-05-01

The contribution of rib fractures to prolonged pain and disability may be underappreciated and undertreated. Clinicians are traditionally taught that the pain and disability of rib fractures resolves in 6 to 8 weeks. This study was a prospective observation of 203 patients with rib fractures at a level 1 trauma center. Chest wall pain was evaluated by the McGill Pain Questionnaire (MPQ) pain rating index (PRI) and present pain intensity (PPI). Prolonged pain was defined as a PRI of 8 or more at 2 months after injury. Prolonged disability was defined as a decrease in 1 or more levels of work or functional status at 2 months after injury. Predictors of prolonged pain and disability were determined by multivariate analysis. One hundred forty-five male patients and 58 female patients with a mean injury severity score (ISS) of 20 (range, 1 to 59) had a mean of 5.4 rib fractures (range, 1 to 29). Forty-four (22%) patients had bilateral fractures, 15 (7%) had flail chest, and 92 (45%) had associated injury. One hundred eighty-seven patients were followed 2 months or more. One hundred ten (59%) patients had prolonged chest wall pain and 142 (76%) had prolonged disability. Among 111 patients with isolated rib fractures, 67 (64%) had prolonged chest wall pain and 69 (66%) had prolonged disability. MPQ PPI was predictive of prolonged pain (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.4 to 2.5), and prolonged disability (OR, 2.2; 95% CI, 1.5 to 3.4). The presence of significant associated injuries was predictive of prolonged disability (OR, 5.9; 95% CI, 1.4 to 29). Prolonged chest wall pain is common, and the contribution of rib fractures to disability is greater than traditionally expected. Further investigation into more effective therapies that prevent prolonged pain and disability after rib fractures is needed. Copyright © 2013 Elsevier Inc. All rights reserved.

The reaction times of drivers aged 20 to 80 during a divided attention driving.

Science.gov (United States)

Svetina, Matija

2016-11-16

Many studies addressing age-related changes in driving performance focus on comparing young vs. older drivers, which might lead to the biased conclusion that driving performance decreases only after the age of 65. The main aim of the study was to show that changes in driving performance are progressive throughout the adult years. A sample of 351 drivers aged 20 to 80 was assessed for their reaction times while driving between road cones. The drivers were exposed to 2 conditions varying according to task complexity. In single task conditions, the drivers performed a full stopping maneuver at a given signal; in dual task conditions, the drivers were distracted before the signal for stopping maneuver was triggered. Reaction times were compared across conditions and age groups. The results showed that both reaction times and variability of driving performance increased progressively between the ages of 20 and 80. The increase in both reaction times and variability was greater in the complex task condition. The high-performing quarter of elderly drivers performed equally well or better than younger drivers did. The data clearly supported the claim that driving performance changes steadily across age groups: both mean reaction time and interindividual variability progressively increase with age. In addition, a significant group of older drivers was identified who did not show the expected age-related decrease in performance. The findings have important implications, suggesting that in relation to driving, aging is a progressive phenomenon and may lead to variety of driving performance; age-related studies of driving performance should put more emphasis on investigating changes across the whole driver age range rather than only comparing younger and older drivers.

Mitigating prolonged QT interval in cancer nanodrug development for accelerated clinical translation.

Science.gov (United States)

Ranjan, Amalendu P; Mukerjee, Anindita; Helson, Lawrence; Vishwanatha, Jamboor K

2013-12-14

Cardiac toxicity is the foremost reason for drug discontinuation from development to clinical evaluation and post market surveillance [Fung 35:293-317, 2001; Piccini 158:317-326 2009]. The Food and Drug Administration (FDA) has rejected many potential pharmaceutical agents due to QT prolongation effects. Since drug development and FDA approval takes an enormous amount of time, money and effort with high failure rates, there is an increased focus on rescuing drugs that cause QT prolongation. If these otherwise safe and potent drugs were formulated in a unique way so as to mitigate the QT prolongation associated with them, these potent drugs may get FDA approval for clinical use. Rescuing these compounds not only benefit the patients who need them but also require much less time and money thus leading to faster clinical translation. In this study, we chose curcumin as our drug of choice since it has been shown to posses anti-tumor properties against various cancers with limited toxicity. The major limitations with this pharmacologically active drug are (a) its ability to prolong QT by inhibiting the hERG channel and (b) its low bioavailability. In our previous studies, we found that lipids have protective actions against hERG channel inhibition and therefore QT prolongation. Results of the manual patch clamp assay of HEK 293 cells clearly illustrated that our hybrid nanocurcumin formulation prevented the curcumin induced inhibition of hERG K+ channel at concentrations higher than the therapeutic concentrations of curcumin. Comparing the percent inhibition, the hybrid nanocurcumin limited inhibition to 24.8% at a high curcumin equivalent concentration of 18 μM. Liposomal curcumin could only decrease this inhibition upto 30% only at lower curcumin concentration of 6 μM but not at 18 μM concentration. Here we show a curcumin encapsulated lipopolymeric hybrid nanoparticle formulation which could protect against QT prolongation and also render increased

Analysis of interaction of some systems of the organism in the prolonged time after radiation exposure

International Nuclear Information System (INIS)

Akoev, I.G.

1978-01-01

Prolonged observations have been carried out of the composition of the form elements of white and red blood and hemoglobin content in dogs irradiated with the 400 R dose as well as of the nine factors of the punctate of bone marrow characterizing the division and ripening of red and white sprouts. On the base of comparison of dynamics of these fourteen indices the following conclusions on the sequence of inclusion and exclusion of hemopoiesis reserves have been made. The primacy of hemopoiesis to the red side exists always when there is an insufficient quantity of erythrocytes and hemoglobin in them important for organism. The first reserve to be mobilized and mostly used is the expansion of hemopoiesis spring-board, the second-accelerated passage of cells of the dividingand dividing-ripening pools. Later and for a very short time the number of mitoses increases in erythroblasts which directly reflects the reduction of their generative cycle

Prolonged hemodynamic response during incidental facial emotion processing in inter-episode bipolar I disorder.

Science.gov (United States)

Rosenfeld, Ethan S; Pearlson, Godfrey D; Sweeney, John A; Tamminga, Carol A; Keshavan, Matcheri S; Nonterah, Camilla; Stevens, Michael C

2014-03-01

This fMRI study examined whether hemodynamic responses to affectively-salient stimuli were abnormally prolonged in remitted bipolar disorder, possibly representing a novel illness biomarker. A group of 18 DSM-IV bipolar I-diagnosed adults in remission and a demographically-matched control group performed an event-related fMRI gender-discrimination task in which face stimuli had task-irrelevant neutral, happy or angry expressions designed to elicit incidental emotional processing. Participants' brain activation was modeled using a "fully informed" SPM5 basis set. Mixed-model ANOVA tested for diagnostic group differences in BOLD response amplitude and shape within brain regions-of-interest selected from ALE meta-analysis of previous comparable fMRI studies. Bipolar-diagnosed patients had a generally longer duration and/or later-peaking hemodynamic response in amygdala and numerous prefrontal cortex brain regions. Data are consistent with existing models of bipolar limbic hyperactivity, but the prolonged frontolimbic response more precisely details abnormalities recognized in previous studies. Prolonged hemodynamic responses were unrelated to stimulus type, task performance, or degree of residual mood symptoms, suggesting an important novel trait vulnerability brain dysfunction in bipolar disorder. Bipolar patients also failed to engage pregenual cingulate and left orbitofrontal cortex-regions important to models of automatic emotion regulation-while engaging a delayed dorsolateral prefrontal cortex response not seen in controls. These results raise questions about whether there are meaningful relationships between bipolar dysfunction of specific ventromedial prefrontal cortex regions believed to automatically regulate emotional reactions and the prolonged responses in more lateral aspects of prefrontal cortex.

Prolonged delirium misdiagnosed as a mood disorder.

Science.gov (United States)

Cao, Fei; Salem, Haitham; Nagpal, Caesa; Teixeira, Antonio L

2017-01-01

Delirium can be conceptualized as an acute decline in cognitive function that typically lasts from hours to a few days. Prolonged delirium can also affect patients with multiple predisposing and/or precipitating factors. In clinical practice, prolonged delirium is often unrecognized, and can be misdiagnosed as other psychiatric disorders. We describe a case of a 59-year-old male presenting with behavioral and cognitive symptoms that was first misdiagnosed as a mood disorder in a general hospital setting. After prolonged delirium due to multiple factors was confirmed, the patient was treated accordingly with symptomatic management. He evolved with progressive improvement of his clinical status. Early diagnosis and management of prolonged delirium are important to improve patient prognosis and avoid iatrogenic measures.

Socio-demographic correlates of prolonged television viewing time in Australian men and women: the AusDiab study.

Science.gov (United States)

Clark, Bronwyn Kay; Sugiyama, Takemi; Healy, Genevieve N; Salmon, Jo; Dunstan, David W; Shaw, Jonathan E; Zimmet, Paul Z; Owen, Neville

2010-09-01

Sedentary behaviors, particularly television viewing (TV) time, are associated with adverse health outcomes in adults, independent of physical activity levels. These associations are stronger and more consistent for women than for men. Multivariate regression models examined the sociodemographic correlates of 2 categories of TV time (≥ 2 hours/day and ≥ 4 hours/day); in a large, population-based sample of Australian adults (4950 men, 6001 women; mean age 48.1 years, range 25-91) who participated in the 1999/2000 Australian Diabetes, Obesity, and Lifestyle (AusDiab) study. Some 46% of men and 40% of women watched ≥ 2 hours TV/day; 9% and 6% respectively watched ≥ 4 hours/day. For both men and women, ≥ 2 hours TV/day was associated with less than tertiary education, living outside of state capital cities, and having no paid employment. For women, mid and older age (45-64 and 65+) were also significant correlates of ≥ 2 hours TV/day. Similar patterns of association were observed in those viewing ≥ 4 hours/day. Prolonged TV time is associated with indices of social disadvantage and older age. These findings can inform the understanding of potential contextual influences and guide preventive initiatives.

Extensive deep vein thrombosis following prolonged gaming ('gamer's thrombosis'): a case report.

Science.gov (United States)

Chang, Hsien-Cheng Leon; Burbridge, Hayley; Wong, Conroy

2013-10-08

The average time spent playing video games is increasing. Prolonged immobility associated with gaming may therefore be an important risk factor for venous thromboembolism. We report a case of deep vein thrombosis associated with prolonged playing of PlayStation® games. A 31-year-old Caucasian man, an exterior painter, presented with a three-day history of left leg pain and swelling after playing PlayStation® games for almost eight hours a day for four consecutive days. Doppler ultrasound of the left leg confirmed extensive left leg deep venous thrombosis requiring thrombolysis and anticoagulation. Video gaming should be considered a risk factor for venous thromboembolism. Further studies are needed to estimate the degree of risk associated with prolonged periods of playing video games, and education for preventing venous thrombosis should be provided to gamers.

Dominant Lid Tectonics behaviour of continental lithosphere in Precambrian times: Palaeomagnetism confirms prolonged quasi-integrity and absence of supercontinent cycles

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J.D.A. Piper

2018-01-01

Full Text Available Although Plate Tectonics cannot be effectively tested by palaeomagnetism in the Precambrian aeon due to the paucity of high precision poles spanning such a long time period, the possibility of Lid Tectonics is eminently testable because it seeks accordance of the wider dataset over prolonged intervals of time; deficiencies and complexities in the data merely contribute to dispersion. Accordance of palaeomagnetic poles across a quasi-integral continental crust for time periods of up to thousands of millions of years, together with recognition of very long intervals characterised by minimal polar motions (∼2.6–2.0, ∼1.5–1.25 and ∼0.75–0.6 Ga has been used to demonstrate that Lid Tectonics dominated this aeon. The new PALEOMAGIA database is used to refine a model for the Precambrian lid incorporating a large quasi-integral crescentric core running from South-Central Africa through Laurentia to Siberia with peripheral cratons subject to reorganisation at ∼2.1, ∼1.6 and ∼1.1 Ga. The model explains low levels of tidal friction, reduced heat balance, unique petrologic and isotopic signatures, and the prolonged crustal stability of Earth's “Middle Age”, whilst density concentrations of the palaeomagnetic poles show that the centre of the continental lid was persistently focussed near Earth's rotation axis from ∼2.8 to 0.6 Ga. The exception was the ∼2.7–2.2 Ga interval defined by ∼90° polar movements which translated the periphery of the lid to the rotation pole for this quasi-static period, a time characterised by glaciation and low levels of magmatic activity; the ∼2.7 Ga shift correlates with key interval of mid-Archaean crustal growth to some 60–70% of the present volume and REE signatures whilst the ∼2.2 Ga shift correlates with the Lomagundi δ13 C and Great Oxygenation events. The palaeomagnetic signature of breakup of the lid at ∼0.6 Ga is recorded by the world-wide Ediacaran development of passive

Licence prolongations of US nuclear power plants

International Nuclear Information System (INIS)

2004-04-01

Licences of US nuclear reactors were initially attributed for a 40 years duration. However, the vast majority of the reactors can benefit of a licence prolongation for a period of 20 years maximum. This article recalls first the procedure to follow for the licence prolongation demands (safety analysis, components aging, environmental impact statement), and then it makes a status of the accepted prolongations, of the demands under examination, and of the demands that should be presented in the next 5 years. (J.S.)

Measurement of Visual Reaction Times Using Hand-held Mobile Devices

Science.gov (United States)

Mulligan, Jeffrey B.; Arsintescu, Lucia; Flynn-Evans, Erin

2015-01-01

Modern mobile devices provide a convenient platform for collecting research data in the field. But,because the working of these devices is often cloaked behind multiple layers of proprietary system software, it can bedifficult to assess the accuracy of the data they produce, particularly in the case of timing. We have been collecting datain a simple visual reaction time experiment, as part of a fatigue testing protocol known as the Psychomotor Vigilance Test (PVT). In this protocol, subjects run a 5-minute block consisting of a sequence of trials in which a visual stimulus appears after an unpredictable variable delay. The subject is required to tap the screen as soon as possible after the appearance of the stimulus. In order to validate the reaction times reported by our program, we had subjects perform the task while a high-speed video camera recorded both the display screen, and a side view of the finger (observed in a mirror). Simple image-processing methods were applied to determine the frames in which the stimulus appeared and disappeared, and in which the finger made and broke contact with the screen. The results demonstrate a systematic delay between the initial contact by the finger and the detection of the touch by the software, having a value of 80 +- 20 milliseconds.

The use of real-time polymerase chain reaction for rapid diagnosis of skeletal tuberculosis.

Science.gov (United States)

Kobayashi, Naomi; Fraser, Thomas G; Bauer, Thomas W; Joyce, Michael J; Hall, Gerri S; Tuohy, Marion J; Procop, Gary W

2006-07-01

We identified Mycobacterium tuberculosis DNA using real-time polymerase chain reaction on a specimen from an osteolytic lesion of a femoral condyle, in which the frozen section demonstrated granulomas. The process was much more rapid than is possible with culture. The rapid detection of M tuberculosis and the concomitant exclusion of granulomatous disease caused by nontuberculous mycobacteria or systemic fungi are necessary to appropriately treat skeletal tuberculosis. The detection and identification of M tuberculosis by culture may require several weeks using traditional methods. The real-time polymerase chain reaction method used has been shown to be rapid and reliable, and is able to detect and differentiate both tuberculous and nontuberculous mycobacteria. Real-time polymerase chain reaction may become a diagnostic standard for the evaluation of clinical specimens for the presence of mycobacteria; this case demonstrates the potential utility of this assay for the rapid diagnosis of skeletal tuberculosis.

THE INFLUENCE OF BALL VELOCITY AND COURT ILLUMINATION ON REACTION TIME FOR TENNIS VOLLEY

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Jui-hung Tu

2010-03-01

Full Text Available The he purpose of this study is to examine the effects of ball velocity, court illumination, and volley type on the reaction time (RT of a tennis athlete for a volley stroke. Eights cases with two different ball velocities (high and low, two volley types (forehand and backhand and two court illumination levels (dark and bright were studied. The 30 participating subjects consisted of 18 male and 12 female college tennis athletes (age: 24 ± 3.2 yr, with a United States Tennis Association (USTA ranking above 2.5. In order to ensure the validity of real-world correlations, the experiments were designed to simulate real competition situations. Reaction times were measured for volley strokes in response to different approaching ball velocities (high: 25.05 ± 0.37 m/s and low: 17.56 ± 0.92 m·s-1 for several volley types (forehand and backhand and court illumination levels (55649 ± 4292 lux and 363.24 ± 6.53 lux on the court. During the tests, the signals from an electromyogram sensor and a 3-axis accelerometer (± 50 g were recorded using an NI DAQ card (NI PXI-6251 and then analyzed to determine reaction time (RT, premotor reaction time (PRT, and motor reaction time (MRT through the LabVIEW system. Subsequent 3-way ANOVA analysis indicated no RT, PRT, or MRT interaction between ball velocity, volley type and illumination. The ball velocity and illumination parameters did affect RT and PRT values significantly with p < 0.05, no significant variation in MRT was observed across any implemented experimental conditions. All experimental results indicate that ball velocity and illumination levels strongly affect the value of PRT, but have no significant effect on the value of MRT, the changes in RT were dominated by PRT

Predictive factors for oropharyngeal dysphagia after prolonged orotracheal intubation.

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Oliveira, Ana Carolina Martins de; Friche, Amélia Augusta de Lima; Salomão, Marina Silva; Bougo, Graziela Chamarelli; Vicente, Laélia Cristina Caseiro

2017-09-13

Lesions in the oral cavity, pharynx and larynx due to endotracheal intubation can cause reduction in the local motility and sensitivity, impairing the swallowing process, resulting in oropharyngeal dysphagia. To verify the predictive factors for the development of oropharyngeal dysphagia and the risk of aspiration in patients with prolonged orotracheal intubation admitted to an intensive care unit. This is an observational, analytical, cross-sectional and retrospective data collection study of 181 electronic medical records of patients submitted to prolonged orotracheal intubation. Data on age; gender; underlying disease; associated comorbidities; time and reason for orotracheal intubation; Glasgow scale on the day of the Speech Therapist assessment; comprehension; vocal quality; presence and severity of dysphagia; risk of bronchoaspiration; and the suggested oral route were collected. The data were analyzed through logistic regression. The level of significance was set at 5%, with a 95% Confidence Interval. The prevalence of dysphagia in this study was 35.9% and the risk of aspiration was 24.9%. As the age increased, the altered vocal quality and the degree of voice impairment increased the risk of the presence of dysphagia by 5-; 45.4- and 6.7-fold, respectively, and of aspiration by 6-; 36.4- and 4.8-fold. The increase in the time of orotracheal intubation increased the risk of aspiration by 5.5-fold. Patients submitted to prolonged intubation who have risk factors associated with dysphagia and aspiration should be submitted to an early speech-language/audiology assessment and receive appropriate and timely treatment. The recognition of these predictive factors by the entire multidisciplinary team can minimize the possibility of clinical complications inherent to the risk of dysphagia and aspiration in extubated patients. Copyright © 2017. Published by Elsevier Editora Ltda.

Diagnosis of penicillin allergy revisited: the value of case history, skin testing, specific IgE and prolonged challenge.

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Hjortlund, J; Mortz, C G; Skov, P S; Bindslev-Jensen, C

2013-08-01

Skin testing in duplicate, correlation between case history of immediate and nonimmediate reactions and challenge outcome and prolonged oral treatment with penicillin in the diagnostic evaluation of allergic reactions to β-lactam antibiotics, mimicking real-life situations, have only been addressed in few studies. A total of 342 patients suspected of having β-lactam allergy were investigated according to the European Network for Drug Allergy (ENDA) guidelines and patients found to be negative in the ENDA program were supplemented with a 7-day oral treatment with penicillin. Skin testing with penicillins was performed in duplicate. Patients with case histories of reactions to other β-lactams were also subsequently challenged with the culprit drug. Nineteen patients were IgE-sensitized to penicillin. Then, intracutaneous tests (ICTs) were performed, in which 35 patients tested positive for allergy, 21 with delayed and 14 with immediate reactions. Only three patients tested positive for the major (PPL) and/or minor (MDM) penicillin determinants, all being positive for penicillin G in ICT. The remaining 291 patients were challenged with penicillin: 10 tested positive in single-dose challenge and 23 tested positive in the 7-day challenge. A total of 17 of 78 patients with a negative penicillin challenge tested positive during challenges with other β-lactams. We found no correlation between case histories of immediate and nonimmediate reactions and reaction time during challenge. The data suggest that case history is often insufficient to discriminate between immediate reactors and nonimmediate reactors. A 7-day challenge with the culprit β-lactam may yield more positive reactions than the accepted one- or 2-day challenge. Interpretation of skin testing should be made with caution. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Editor's Choice - Prolonged ICU Length of Stay after AAA Repair: Analysis of Time Trends and Long-term Outcome.

Science.gov (United States)

Gavali, H; Mani, K; Tegler, G; Kawati, R; Covaciu, L; Wanhainen, A

2017-08-01

The aim of the study was to investigate the frequency and outcome of prolonged intensive care unit (ICU) length of stay (LOS) after abdominal aortic aneurysm (AAA) repair in the endovascular era. All patients operated on for AAA between 1999 and 2013 at Uppsala University hospital were identified. Data were retrieved from the Swedish Vascular registry, the Swedish Intensive Care registry, the National Population registry, and case records. Prolonged ICU LOS was defined as ≥ 48 h during the primary hospital stay. Patients surviving ≥ 48 h after AAA surgery were included in the analysis. A total of 725 patients were identified, of whom 707 (97.5%) survived ≥ 48 h; 563 (79.6%) underwent intact AAA repair and 144 (20.4%) ruptured AAA repair. A total of 548 patients (77.5%) required AAA repairs in 1999 to 7.3% in 2013 (p < .001) whereas the use of endovascular aortic repair (EVAR) increased from 6.9% in 1999 to 78.0% in 2013 (p < .001). The 30 day survival rate was 98.2% for those with < 48 h ICU stay versus 93.0% for 2-6 days versus 81.8% for ≥ 7 days (p < .001); the corresponding 90 day survival was 97.1% versus 86.1% versus 63.6% (p < .001) respectively. For patients surviving 90 days after repair, there was no difference in long-term survival between the groups. During the period of progressively increasing use of EVAR, a simultaneous significant reduction in frequency of prolonged ICU LOS occurred. Although prolonged ICU LOS was associated with a high short-term mortality, long-term outcome among those surviving the initial 90 days was less affected. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Individual Differences in Components of Reaction Time Distributions and Their Relations to Working Memory and Intelligence

Science.gov (United States)

Schmiedek, Florian; Oberauer, Klaus; Wilhelm, Oliver; Suss, Heinz-Martin; Wittmann, Werner W.

2007-01-01

The authors bring together approaches from cognitive and individual differences psychology to model characteristics of reaction time distributions beyond measures of central tendency. Ex-Gaussian distributions and a diffusion model approach are used to describe individuals' reaction time data. The authors identified common latent factors for each…

The influence of gymnastics in motor coordination and reaction time in urban public bus drivers

Directory of Open Access Journals (Sweden)

Stela Paula Mezzomo

2014-12-01

Full Text Available This study investigated the influence of labour gymnastics (LG on bus drivers' basic skills such as reaction time and gross motor coordination. Sixty male bus drivers (37.06 ± 7.66 years old from two bus lines in the city of Santa Maria (RS took part of this study. The participants were split into two groups, experimental group (EG and control group (CG. Subjects that were part of the EG took part in a LG intervention program, 2-3 times a week, over a year. Gross motor coordination was assessed by BURPEE Protocol (Johnson & Nelson, 1979, whereas reaction time by software providing a visual stimulus. Data normality was checked through Shapiro-Wilk test, which pointed to normal distribution only for the variables simple reaction time (SRT and choice reaction time (CRT in the EG. Therefore the non-parametric Mann-Whitney U test was selected to compare differences between groups. A statistically significant difference for gross motor coordination was found (z= −2.525, p= 0.012, suggesting the effectiveness of LG to improve motor skills. As regards SRT and CRT, no significant difference was found, in spite of better outcomes having been recorded after the LG program.

TIMES-SS - A mechanistic evaluation of an external validation study using reaction chemistry principles

DEFF Research Database (Denmark)

Roberts, David W.; Patlewicz, Grace; Dimitrov, Sabcho D.

2007-01-01

The TImes MEtabolism Simulator platform used for predicting skin sensitization (TIMES-SS) is a hybrid expert system that was developed at Bourgas University using funding and data from a consortium comprised of industry and regulators. TIMES-SS encodes structure-toxicity and structure...... chemicals in the murine local lymph node assay (LLNA) and then compared with predictions made by TIMES-SS. The results were promising with an overall good concordance (83%) between experimental and predicted values. The LLNA results were evaluated with respect to reaction chemistry principles...... for sensitization. Additional testing on a further four chemicals was carried out to explore some of the specific reaction chemistry findings in more detail. Improvements for TIMES-SS, where appropriate, were put forward together with proposals for further research work. TIMES-SS is a promising tool to aid...

Existence and Stability of Traveling Waves for Degenerate Reaction-Diffusion Equation with Time Delay

Science.gov (United States)

Huang, Rui; Jin, Chunhua; Mei, Ming; Yin, Jingxue

2018-01-01

This paper deals with the existence and stability of traveling wave solutions for a degenerate reaction-diffusion equation with time delay. The degeneracy of spatial diffusion together with the effect of time delay causes us the essential difficulty for the existence of the traveling waves and their stabilities. In order to treat this case, we first show the existence of smooth- and sharp-type traveling wave solutions in the case of c≥c^* for the degenerate reaction-diffusion equation without delay, where c^*>0 is the critical wave speed of smooth traveling waves. Then, as a small perturbation, we obtain the existence of the smooth non-critical traveling waves for the degenerate diffusion equation with small time delay τ >0 . Furthermore, we prove the global existence and uniqueness of C^{α ,β } -solution to the time-delayed degenerate reaction-diffusion equation via compactness analysis. Finally, by the weighted energy method, we prove that the smooth non-critical traveling wave is globally stable in the weighted L^1 -space. The exponential convergence rate is also derived.

Existence and Stability of Traveling Waves for Degenerate Reaction-Diffusion Equation with Time Delay

Science.gov (United States)

Huang, Rui; Jin, Chunhua; Mei, Ming; Yin, Jingxue

2018-06-01

This paper deals with the existence and stability of traveling wave solutions for a degenerate reaction-diffusion equation with time delay. The degeneracy of spatial diffusion together with the effect of time delay causes us the essential difficulty for the existence of the traveling waves and their stabilities. In order to treat this case, we first show the existence of smooth- and sharp-type traveling wave solutions in the case of c≥c^* for the degenerate reaction-diffusion equation without delay, where c^*>0 is the critical wave speed of smooth traveling waves. Then, as a small perturbation, we obtain the existence of the smooth non-critical traveling waves for the degenerate diffusion equation with small time delay τ >0. Furthermore, we prove the global existence and uniqueness of C^{α ,β }-solution to the time-delayed degenerate reaction-diffusion equation via compactness analysis. Finally, by the weighted energy method, we prove that the smooth non-critical traveling wave is globally stable in the weighted L^1-space. The exponential convergence rate is also derived.

A controlled study on batted ball speed and available pitcher reaction time in slowpitch softball

Science.gov (United States)

McDowell, M; Ciocco, M

2005-01-01

Objectives: To investigate safety risks in slowpitch softball by conducting laboratory and experimental studies on the performance of high tech softball bats with polyurethane softballs. To compare the results with the recommended safety standards. Methods: ASTM standard compression testing of seven softball models was conducted. Using these seven softball models, bat/ball impact testing was performed using seven adult male softball players and six high tech softball bat models to determine mean batted ball speeds. Over 500 bat/ball impact measurements were recorded and analysed. Available pitcher reaction time was calculated from the mean batted ball speed measurements. Results: According to the United States Specialty Sports Association and the Amateur Softball Association, the maximum initial batted ball speed should be 137.2 km/h, which corresponds to a minimum pitcher reaction time of 0.420 second. These experiments produced mean batted ball speeds of 134.0–159.7 km/h, which correspond to available pitcher reaction times of 0.409–0.361 second. Conclusion: The use of high tech softball bats with polyurethane softballs can result in batted ball speeds that exceed the recommended safety limits, which correspond to decreased available pitcher reaction times. PMID:15793092

The cortisol awakening response is associated with performance of a serial sequence reaction time task.

Science.gov (United States)

Hodyl, Nicolette A; Schneider, Luke; Vallence, Ann-Maree; Clow, Angela; Ridding, Michael C; Pitcher, Julia B

2016-02-01

There is emerging evidence of a relationship between the cortisol awakening response (CAR) and the neural mechanisms underlying learning and memory. The aim of this study was to determine whether the CAR is associated with acquisition, retention and overnight consolidation or improvement of a serial sequence reaction time task. Salivary samples were collected at 0, 15, 30 and 45 min after awakening in 39 healthy adults on 2 consecutive days. The serial sequence reaction time task was repeated each afternoon. Participants completed the perceived stress scale and provided salivary samples prior to testing for cortisol assessment. While the magnitude of the CAR (Z score) was not associated with either baseline performance or the timed improvement during task acquisition of the serial sequence task, a positive correlation was observed with reaction times during the stable performance phase on day 1 (r=0.373, p=0.019). Residuals derived from the relationship between baseline and stable phase reaction times on day 1 were used as a surrogate for the degree of learning: these residuals were also correlated with the CAR mean increase on day 1 (r=0.357, p=0.048). Task performance on day 2 was not associated with the CAR obtained on this same day. No association was observed between the perceived stress score, cortisol at testing or task performance. These data indicate that a smaller CAR in healthy adults is associated with a greater degree of learning and faster performance of a serial sequence reaction time task. These results support recognition of the CAR as an important factor contributing to cognitive performance throughout the day. Copyright © 2015 Elsevier B.V. All rights reserved.

Factoring out nondecision time in choice reaction time data: Theory and implications.

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Verdonck, Stijn; Tuerlinckx, Francis

2016-03-01

Choice reaction time (RT) experiments are an invaluable tool in psychology and neuroscience. A common assumption is that the total choice response time is the sum of a decision and a nondecision part (time spent on perceptual and motor processes). While the decision part is typically modeled very carefully (commonly with diffusion models), a simple and ad hoc distribution (mostly uniform) is assumed for the nondecision component. Nevertheless, it has been shown that the misspecification of the nondecision time can severely distort the decision model parameter estimates. In this article, we propose an alternative approach to the estimation of choice RT models that elegantly bypasses the specification of the nondecision time distribution by means of an unconventional convolution of data and decision model distributions (hence called the D*M approach). Once the decision model parameters have been estimated, it is possible to compute a nonparametric estimate of the nondecision time distribution. The technique is tested on simulated data, and is shown to systematically remove traditional estimation bias related to misspecified nondecision time, even for a relatively small number of observations. The shape of the actual underlying nondecision time distribution can also be recovered. Next, the D*M approach is applied to a selection of existing diffusion model application articles. For all of these studies, substantial quantitative differences with the original analyses are found. For one study, these differences radically alter its final conclusions, underlining the importance of our approach. Additionally, we find that strongly right skewed nondecision time distributions are not at all uncommon. (c) 2016 APA, all rights reserved).

Photonuclear reactions triggered by lightning discharge.

Science.gov (United States)

Enoto, Teruaki; Wada, Yuuki; Furuta, Yoshihiro; Nakazawa, Kazuhiro; Yuasa, Takayuki; Okuda, Kazufumi; Makishima, Kazuo; Sato, Mitsuteru; Sato, Yousuke; Nakano, Toshio; Umemoto, Daigo; Tsuchiya, Harufumi

2017-11-22

Lightning and thunderclouds are natural particle accelerators. Avalanches of relativistic runaway electrons, which develop in electric fields within thunderclouds, emit bremsstrahlung γ-rays. These γ-rays have been detected by ground-based observatories, by airborne detectors and as terrestrial γ-ray flashes from space. The energy of the γ-rays is sufficiently high that they can trigger atmospheric photonuclear reactions that produce neutrons and eventually positrons via β + decay of the unstable radioactive isotopes, most notably 13 N, which is generated via 14 N + γ →  13 N + n, where γ denotes a photon and n a neutron. However, this reaction has hitherto not been observed conclusively, despite increasing observational evidence of neutrons and positrons that are presumably derived from such reactions. Here we report ground-based observations of neutron and positron signals after lightning. During a thunderstorm on 6 February 2017 in Japan, a γ-ray flash with a duration of less than one millisecond was detected at our monitoring sites 0.5-1.7 kilometres away from the lightning. The subsequent γ-ray afterglow subsided quickly, with an exponential decay constant of 40-60 milliseconds, and was followed by prolonged line emission at about 0.511 megaelectronvolts, which lasted for a minute. The observed decay timescale and spectral cutoff at about 10 megaelectronvolts of the γ-ray afterglow are well explained by de-excitation γ-rays from nuclei excited by neutron capture. The centre energy of the prolonged line emission corresponds to electron-positron annihilation, providing conclusive evidence of positrons being produced after the lightning.

Prolonged Activated Clotting Time after Protamine Administration Does Not Indicate Residual Heparinization after Cardiopulmonary Bypass in Pediatric Open Heart Surgery.

Science.gov (United States)

Yamamoto, Tomohiro; Wolf, Hans-Gerd; Sinzobahamvya, Nicodème; Asfour, Boulos; Hraska, Victor; Schindler, Ehrenfried

2015-08-01

In open heart surgery, heparinization is commonly neutralized using an empirical heparin:protamine ratio ranging between 1:1 and 1:1.5. However, these ratios may result in protamine overdose that should be avoided for its negative side effects on the coagulation system. This study aimed to indicate the appropriate treatment for prolonged activated clotting time (ACT) after protamine administration following cardiopulmonary bypass (CPB) in pediatric open heart surgery by investigating the underlying reasons for it. Twenty-seven children (open heart surgery were included. Heparin was administered only before CPB (400 IU/kg) and in the pump priming volume for CPB (2,000 IU) and was neutralized by 1:1 protamine after CPB. The blood heparin concentration was measured using anti-Xa assay. ACT and blood concentrations of heparin, coagulation factors, thrombin-antithrombin complex, and prothrombin fragment 1 + 2 were assessed. A rotational thromboelastometry (ROTEM; Tem International GmbH, München, Bayern, Germany) was used to confirm the coagulation status and residual heparin after protamine administration. Anti-Xa assay showed that there is no residual heparin in the blood after 1:1 protamine administration. Nevertheless, ACT (128.89 ± 3.09 seconds before heparin administration) remained prolonged (177.14 ± 5.43 seconds at 10 minutes after protamine, 182.00 ± 5.90 seconds at 30 minutes after protamine). The blood concentrations of coagulation factors were significantly lower than those before heparin administration (p < 0.01). The low FIBTEM MCF of ROTEM (4.43 ± 0.32 mm) at 10 minutes after protamine indicated low fibrinogen concentration. Prolonged ACT after heparin neutralization by 1:1 protamine administration does not necessarily indicate residual heparin, but low blood concentrations of coagulation factors should be considered as a reason as well. Accordingly, supply of coagulation factors instead of additional protamine should be

Prenatal risk indicators of a prolonged pregnancy

DEFF Research Database (Denmark)

Olesen, Annette Wind; Westergaard, Jes Grabow; Olsen, Jørn

2006-01-01

BACKGROUND: Few prenatal risk factors of prolonged pregnancy, a pregnancy of 42 weeks or more, are known. The objective was to examine whether sociodemographic, reproductive, toxicologic, or medical health conditions were associated with the risk of prolonged pregnancy. METHODS: Data from...

A study of the predictive model on the user reaction time using the information amount and its similarity

International Nuclear Information System (INIS)

Lee, Sung Jin; Heo, Gyun Young; Chang, Soon Heung

2004-01-01

There are lots of studies on the user interface evaluation since it started. Recent studies focus on the contextual information of the user interface. We knew that the user reaction time increases as the amount of information increases. But, the relation between the contextual information and the user reaction time may be unknown. In this study, we proposed the similarity as one of the contextual information. We can expect that the similarity decreases the user reaction time. The goal of this study is to find some correlation about the user reaction time with both the information amount and the similarity. The experiment was performed with 20 participants. The results of experiment demonstrated our proposals

Does UTI cause prolonged jaundice in otherwise well infants?

Science.gov (United States)

Chowdhury, Tanzila; Kisat, Hamudi; Tullus, Kjell

2015-07-01

The symptoms of urinary tract infections in infants are very non-specific and have historically included prolonged hyperbilirubinaemia. We studied the results of routine urine samples in 319 infants with prolonged jaundice. Convincing findings of UTI was not found in any of these children even if one of them was treated with antibiotics after four consecutive urine cultures with different bacteria. A urine culture might thus not be an appropriate investigation in a child with prolonged jaundice without any other symptoms of UTI. • The symptoms of UTI in infancy are very non-specific. • Old studies suggest that prolonged hyperbilirubinaemia is one such symptom; more modern studies give more conflicting results. What is New: • Our study could not confirm that children with prolonged jaundice have an increased risk of UTI. • Routine urine testing is thus not needed in otherwise healthy infants with prolonged jaundice.

Reaction-time-resolved measurements of laser-induced fluorescence in a shock tube with a single laser pulse

Science.gov (United States)

Zabeti, S.; Fikri, M.; Schulz, C.

2017-11-01

Shock tubes allow for the study of ultra-fast gas-phase reactions on the microsecond time scale. Because the repetition rate of the experiments is low, it is crucial to gain as much information as possible from each individual measurement. While reaction-time-resolved species concentration and temperature measurements with fast absorption methods are established, conventional laser-induced fluorescence (LIF) measurements with pulsed lasers provide data only at a single reaction time. Therefore, fluorescence methods have rarely been used in shock-tube diagnostics. In this paper, a novel experimental concept is presented that allows reaction-time-resolved LIF measurements with one single laser pulse using a test section that is equipped with several optical ports. After the passage of the shock wave, the reactive mixture is excited along the center of the tube with a 266-nm laser beam directed through a window in the end wall of the shock tube. The emitted LIF signal is collected through elongated sidewall windows and focused onto the entrance slit of an imaging spectrometer coupled to an intensified CCD camera. The one-dimensional spatial resolution of the measurement translates into a reaction-time-resolved measurement while the species information can be gained from the spectral axis of the detected two-dimensional image. Anisole pyrolysis was selected as the benchmark reaction to demonstrate the new apparatus.

Effect of reaction time on the characteristics of catalytically grown boron nitride nanotubes

Energy Technology Data Exchange (ETDEWEB)

Mohamed, Norani Muti, E-mail: noranimuti-mohamed@petronas.com.my, E-mail: pervaiz-pas@yahoo.com, E-mail: shuaib-penang@yahoo.com, E-mail: zainabh@petronas.com.my; Ahmad, Pervaiz, E-mail: noranimuti-mohamed@petronas.com.my, E-mail: pervaiz-pas@yahoo.com, E-mail: shuaib-penang@yahoo.com, E-mail: zainabh@petronas.com.my; Saheed, Mohamed Shuaib Mohamed, E-mail: noranimuti-mohamed@petronas.com.my, E-mail: pervaiz-pas@yahoo.com, E-mail: shuaib-penang@yahoo.com, E-mail: zainabh@petronas.com.my; Burhanudin, Zainal Arif, E-mail: noranimuti-mohamed@petronas.com.my, E-mail: pervaiz-pas@yahoo.com, E-mail: shuaib-penang@yahoo.com, E-mail: zainabh@petronas.com.my [Center of Innovative Nanostructures and Nanodevices (COINN), Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Tronoh, Perak (Malaysia)

2014-10-24

The paper reports on the growth of boron nitride nanotube (BNNTs) on Si substrate by catalytic chemical vapor deposition technique and the effect of reaction time and temperature on the size and purity were investigated. Scanning electron microscopy image revealed the bamboo-like BNNTs of multiwalled type with interlayer spacing of 0.34 nm. EDX analysis described the presence of a small percentage of Mg in the sample, indicating the combination of base-tip growth model for the sample synthesized at 1200°C. The reaction time has an effect of extending the length of the BNNTs until the catalyst is oxidized or covered by growth precursor.

Effect of reaction time on the characteristics of catalytically grown boron nitride nanotubes

International Nuclear Information System (INIS)

Mohamed, Norani Muti; Ahmad, Pervaiz; Saheed, Mohamed Shuaib Mohamed; Burhanudin, Zainal Arif

2014-01-01

The paper reports on the growth of boron nitride nanotube (BNNTs) on Si substrate by catalytic chemical vapor deposition technique and the effect of reaction time and temperature on the size and purity were investigated. Scanning electron microscopy image revealed the bamboo-like BNNTs of multiwalled type with interlayer spacing of 0.34 nm. EDX analysis described the presence of a small percentage of Mg in the sample, indicating the combination of base-tip growth model for the sample synthesized at 1200°C. The reaction time has an effect of extending the length of the BNNTs until the catalyst is oxidized or covered by growth precursor

Real-time TaqMan polymerase chain reaction to quantify the effects ...

African Journals Online (AJOL)

TaqMan polymerase chain reaction was developed to quantify the number of Bifidobacterium. We used this assay to detect genomic DNA of Bifidobacterium in the intestinal tract digesta of piglets, including duodenum, jejunum, ileum, cecum and colon. Our results indicated that, developed new real-time quantitative PCR ...

The Winter Procedure as Management for Prolonged Low-Flow Priapism: A Case Report

Directory of Open Access Journals (Sweden)

Hsi-Lin Hsiao

2007-10-01

Full Text Available Priapism is a prolonged penile erection that is not associated with sexual stimulation. Although the time course has not been formally defined, it is usually considered to be one that lasts for more than 4–6 hours. Low-flow (ischemic priapism is usually associated with sickle cell disease, hemoglobinopathies, neoplastic syndrome, anticoagulant therapy, psychotropic medication or idiopathic causes. Here, we report a case of prolonged low-flow priapism lasting for 2 weeks, which was successfully treated with the Winter procedure after several attempts of conservative treatment. Although the potency remains unclear and the patient needs a longer period of follow-up, the case reported here still shows that prolonged low-flow priapism can be successfully treated with the Winter procedure when conservative treatments fail.

Global exponential stability of reaction-diffusion recurrent neural networks with time-varying delays

International Nuclear Information System (INIS)

Liang Jinling; Cao Jinde

2003-01-01

Employing general Halanay inequality, we analyze the global exponential stability of a class of reaction-diffusion recurrent neural networks with time-varying delays. Several new sufficient conditions are obtained to ensure existence, uniqueness and global exponential stability of the equilibrium point of delayed reaction-diffusion recurrent neural networks. The results extend and improve the earlier publications. In addition, an example is given to show the effectiveness of the obtained result

Pharmacokinetics of prolonged-release tacrolimus and implications for use in solid organ transplant recipients.

Science.gov (United States)

Tanzi, Maria G; Undre, Nasrullah; Keirns, James; Fitzsimmons, William E; Brown, Malcolm; First, M Roy

2016-08-01

Prolonged-release tacrolimus was developed as a once-daily formulation with ethylcellulose as the excipient, resulting in slower release and reduction in peak concentration (Cmax ) for a given dose compared with immediate-release tacrolimus, which is administered twice daily. This manuscript reviews pharmacokinetic information on prolonged-release tacrolimus in healthy subjects, in transplant recipients converted from immediate-release tacrolimus, and in de novo kidney and liver transplant recipients. As with the immediate-release formulation, prolonged-release tacrolimus shows a strong correlation between trough concentration (Cmin ) and area under the 24-hour time-concentration curve (AUC24 ), indicating that trough whole blood concentrations provide an accurate measure of drug exposure. We present the pharmacokinetic similarities and differences between the two formulations, so that prescribing physicians will have a better understanding of therapeutic drug monitoring in patients receiving prolonged-release tacrolimus. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Co-Liquefaction of Elbistan Lignite with Manure Biomass; Part 3 - Effect of Reaction Time and Temperature

Science.gov (United States)

Koyunoglu, Cemil; Karaca, Hüseyin

2017-12-01

Most of the liquefaction process were carried out in a batch reactor, in which the residence time of the liquefaction products is long enough to favour the retrogressive reactions. To minimize retrogressive reactions, the liquefaction of coal was carried out in a flowing solvent reactor in which a fixed bed of coal is continuously permeated by hot solvent. Solvent flowing through the coal bed carries the liquefaction products out of the reactor. Unlike experiments carried out under similar conditions in a batch reactor no increase in solid residue is observed during long time high temperature runs in the flowing solvent reactor. There is a greater appreciation of the importance of retrograde, or polymerization, reactions. If the free radicals formed when coal breaks down are not quickly capped with hydrogen, they react with each other to form large molecules that are much harder to break down than the original coal. Reaction time impacts both the co-liquefaction cost and the product yield. So as to study this idea, the experiments of Elbistan Lignite (EL) with manure co-liquefaction carried out by changing the reaction time from 30 to 120 minutes. As a result, the greatest oil products yields obtained at 60 minutes. Therefore, by thinking about the oil products yield values acquired, the optimal reaction time was obtained to be 60 minutes for Elbistan lignite (EL) with manure liquefied with the temperature of 350°C and 400°C. Above 425°C did not examine because solvent (tetraline) loses its function after 425 °C. The obtained optimum temperature found 400°C due to higher total conversion of liquefaction products and also oil+gas yields.

Studies of the reactions of hydrogen atoms by time-resolved E. S. R. spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Fessenden, R W; Verma, N C [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Chemistry

1977-01-01

Time-resolved e.s.r. spectroscopy has been used to follow directly the reactions of H atoms produced by pulse radiolysis of acid solutions. Detailed analysis of the time profile of the e.s.r. signal was carried out by means of modified Bloch equations. The increased signal found when a scavenger for OH such as t-butyl alcohol is present is shown to be mainly the result of slower H atom decay by radical-radical reaction. The reaction H + OH does not appear to produce any signal polarization. The decay curves observed in the presence of solute are readily accounted for by the treatment, and good plots of pseudo first-order rate constant against solute concentration are obtained. The absolute rate constants for reaction with H atoms are for methanol 2.5 x10/sup 6/, for ethanol 2.1 X 10/sup 7/, for isopropanol 6.8 x 10/sup 7/, and for succinic acid 3.0 x 10/sup 6/ dm/sup 3/ mol/sup -1/s/sup -1/. These values are in good agreement with the earlier chemical measurements.

Prolonged labour as indication for emergency caesarean section

DEFF Research Database (Denmark)

Maaløe, Nanna; Sorensen, B L; Onesmo, R

2012-01-01

To audit the quality of obstetric management preceding emergency caesarean sections for prolonged labour.......To audit the quality of obstetric management preceding emergency caesarean sections for prolonged labour....

Prolonged Pregnancy: Methods, Causal Determinants and Outcome

DEFF Research Database (Denmark)

Olesen, Annette Wind

) to study the incidence of prolonged pregnancy as a function of methods for determining gestational age; 2) to determine the risk of obstetrical and fetal complications in prolonged pregnancy; 3) to validate the self-reported gestational age in the National Birth Cohort; 4) to determine whether...... an ultrasound scan in the first or second trimester, or menstrual history was best at predicting the day of delivery; 5) to study the risk of recurrence of prolonged pregnancy as a function of change in male partner, social status and municipality; and 6) to detect prenatal risk indicators of prolonged...... of perinatal and obstetrical complications was high in post-term delivery compared to term delivery (OR between 1.2 and 3.1). The risk of perinatal death (OR=1.36 (1.08-1.72)) was also higher in the post-term group (I). The self-reported gestational ages in the National Birth Cohort correlated well with data...

The effects of sodium bicarbonate during prolonged cardiopulmonary resuscitation.

Science.gov (United States)

Weng, Yi-Ming; Wu, Shih-Hao; Li, Wen-Cheng; Kuo, Chan-Wei; Chen, Shou-Yen; Chen, Jih-Chang

2013-03-01

This study was performed to determine the effects of sodium bicarbonate injection during prolonged cardiopulmonary resuscitation (for >15 minutes). The retrospective cohort study consisted of adult patients who presented to the emergency department (ED) with the diagnosis of cardiac arrest in 2009. Data were retrieved from the institutional database. A total of 92 patients were enrolled in the study. Patients were divided into 2 groups based on whether they were treated (group1, n = 30) or not treated (group 2, n = 62) with sodium bicarbonate. There were no significant differences in demographic characteristics between groups. The median time interval between the administration of CPR and sodium bicarbonate injection was 36.0 minutes (IQR: 30.5-41.8 minutes). The median amount of bicarbonate injection was 100.2 mEq (IQR: 66.8-104.4). Patients who received a sodium bicarbonate injection during prolonged CPR had a higher percentage of return of spontaneous circulation, but not statistical significant (ROSC, 40.0% vs. 32.3%; P = .465). Sustained ROSC was achieved by 2 (6.7%) patients in the sodium bicarbonate treatment group, with no survival to discharge. No significant differences in vital signs after ROSC were detected between the 2 groups (heart rate, P = .124; systolic blood pressure, P = .094). Sodium bicarbonate injection during prolonged CPR was not associated with ROSC after adjust for variables by regression analysis (Table 3; P = .615; odds ratio, 1.270; 95% confidence interval: 0.501-3.219) The administration of sodium bicarbonate during prolonged CPR did not significantly improve the rate of ROSC in out-of-hospital cardiac arrest. Copyright © 2013 Elsevier Inc. All rights reserved.

High resolution time-of-flight spectrometer for crossed molecular beam study of elementary chemical reactions

International Nuclear Information System (INIS)

Qiu Minghui; Che Li; Ren Zefeng; Dai Dongxu; Wang Xiuyan; Yang Xueming

2005-01-01

In this article, we describe an apparatus in our laboratory for investigating elementary chemical reactions using the high resolution time-of-flight Rydberg tagging method. In this apparatus, we have adopted a rotating source design so that collision energy can be changed for crossed beam studies of chemical reactions. Preliminary results on the HI photodissociation and the F atom reaction with H 2 are reported here. These results suggest that the experimental apparatus is potentially a powerful tool for investigating state-to-state dynamics of elementary chemical reactions

Risks predicting prolonged hospital discharge boarding in a regional acute care hospital.

Science.gov (United States)

Shaikh, Sajid A; Robinson, Richard D; Cheeti, Radhika; Rath, Shyamanand; Cowden, Chad D; Rosinia, Frank; Zenarosa, Nestor R; Wang, Hao

2018-01-30

Prolonged hospital discharge boarding can impact patient flow resulting in upstream Emergency Department crowding. We aim to determine the risks predicting prolonged hospital discharge boarding and their direct and indirect effects on patient flow. Retrospective review of a single hospital discharge database was conducted. Variables including type of disposition, disposition boarding time, case management consultation, discharge medications prescriptions, severity of illness, and patient homeless status were analyzed in a multivariate logistic regression model. Hospital charges, potential savings of hospital bed hours, and whether detailed discharge instructions provided adequate explanations to patients were also analyzed. A total of 11,527 admissions was entered into final analysis. The median discharge boarding time was approximately 2 h. Adjusted Odds Ratio (AOR) of patients transferring to other hospitals was 7.45 (95% CI 5.35-10.37), to court or law enforcement custody was 2.51 (95% CI 1.84-3.42), and to a skilled nursing facility was 2.48 (95% CI 2.10-2.93). AOR was 0.57 (95% CI 0.47-0.71) if the disposition order was placed during normal office hours (0800-1700). AOR of early case management consultation was 1.52 (95% CI 1.37-1.68) versus 1.73 (95% CI 1.03-2.89) for late consultation. Eighty-eight percent of patients experiencing discharge boarding times within 2 h of disposition expressed positive responses when questioned about the quality of explanations of discharge instructions and follow-up plans based on satisfaction surveys. Similar results (86% positive response) were noted among patients whose discharge boarding times were prolonged (> 2 h, p = 0.44). An average charge of $6/bed/h was noted in all hospital discharges. Maximizing early discharge boarding (≤ 2 h) would have resulted in 16,376 hospital bed hours saved thereby averting $98,256.00 in unnecessary dwell time charges in this study population alone. Type of disposition, case

RKC time-stepping for advection-diffusion-reaction problems

International Nuclear Information System (INIS)

Verwer, J.G.; Sommeijer, B.P.; Hundsdorfer, W.

2004-01-01

The original explicit Runge-Kutta-Chebyshev (RKC) method is a stabilized second-order integration method for pure diffusion problems. Recently, it has been extended in an implicit-explicit manner to also incorporate highly stiff reaction terms. This implicit-explicit RKC method thus treats diffusion terms explicitly and the highly stiff reaction terms implicitly. The current paper deals with the incorporation of advection terms for the explicit method, thus aiming at the implicit-explicit RKC integration of advection-diffusion-reaction equations in a manner that advection and diffusion terms are treated simultaneously and explicitly and the highly stiff reaction terms implicitly

Prolonged ultraviolet light-induced erythema and the cutaneous carcinoma phenotype

International Nuclear Information System (INIS)

Tanenbaum, L.; Parrish, J.A.; Haynes, H.A.; Fitzpatrick, T.B.; Pathak, M.A.

1976-01-01

A considerable amount of evidence exists in support of the role of ultraviolet radiation as a major etiologic factor in human skin cancer, both melanoma and carcinoma types. On the basis of epidemiologic studies a phenotype has been described which helps to identify the persons who are more susceptible to skin cancer. In an attempt to further define this population, patients with cutaneous carcinoma and a normal control group were exposed to artificial ultraviolet light (UVL) and the erythema and tanning responses of each group were measured over a 21-day period. UVL-induced erythema was prolonged in a significantly higher percentage of patients with skin cancer than in control patients, lasting two to three weeks after single exposures to 6 and 8 times the patient's minimal erythema dose. The presence of prolonged erythema correlated with this history of previous skin cancer but did not correlate with other established risk factors for cutaneous carcinoma, i.e., fair skin, light hair and light eyes, easy sunburning and poor tanning, and Celtic ancestry. Prolonged erythema following UVL radiation may therefore represent an additional risk factor and help to identify the skin cancer-susceptible population

Development of an Internal Real-Time Wireless Diagnostic Tool for a Proton Exchange Membrane Fuel Cell

Directory of Open Access Journals (Sweden)

Chi-Yuan Lee

2018-01-01

Full Text Available To prolong the operating time of unmanned aerial vehicles which use proton exchange membrane fuel cells (PEMFC, the performance of PEMFC is the key. However, a long-term operation can make the Pt particles of the catalyst layer and the pollutants in the feedstock gas bond together (e.g., CO, so that the catalyst loses reaction activity. The performance decay and aging of PEMFC will be influenced by operating conditions, temperature, flow and CO concentration. Therefore, this study proposes the development of an internal real-time wireless diagnostic tool for PEMFC, and uses micro-electro-mechanical systems (MEMS technology to develop a wireless and thin (<50 μm flexible integrated (temperature, flow and CO microsensor. The technical advantages are (1 compactness and three wireless measurement functions; (2 elastic measurement position and accurate embedding; (3 high accuracy and sensitivity and quick response; (4 real-time wireless monitoring of dynamic performance of PEMFC; (5 customized design and development. The flexible integrated microsensor is embedded in the PEMFC, three important physical quantities in the PEMFC, which are the temperature, flow and CO, can be measured simultaneously and instantly, so as to obtain the authentic and complete reaction in the PEMFC to enhance the performance of PEMFC and to prolong the service life.

QRTEngine: An easy solution for running online reaction time experiments using Qualtrics

NARCIS (Netherlands)

Barnhoorn, Jonathan Sebastiaan; Haasnoot, Erwin; Bocanegra, Bruno R.; van Steenbergen, Henk

2015-01-01

Performing online behavioral research is gaining increased popularity among researchers in psychological and cognitive science. However, the currently available methods for conducting online reaction time experiments are often complicated and typically require advanced technical skills. In this

Prolonged QRS Widening After Aripiprazole Overdose.

Science.gov (United States)

Mazer-Amirshahi, Maryann; Porter, Robert; Dewey, Kayla

2018-05-05

Aripiprazole is an atypical antipsychotic with a long half-life. Overdose can result in protracted somnolence and cardiac disturbances, particularly QT interval prolongation. This is a single case report of a 14-year-old boy who took an overdose of aripiprazole and developed QRS widening. A 14-year-old boy intentionally ingested 20 tablets of aripiprazole (5 mg). He was brought to the emergency department when his ingestion was discovered. The patient's vital signs were as follows: temperature, 37.7°C; heart rate, 108 beats/min; blood pressure, 138/98 mm Hg; and respirations, 16 breaths/min. Activated charcoal was administered within 90 minutes of ingestion. Initial electrocardiogram (EKG) showed sinus tachycardia, with a QRS of 138 ms and QT interval of 444 ms. QRS duration was 90 ms on an EKG performed 3 months earlier. A bolus of sodium bicarbonate was administered, and the patient was transferred to the pediatric intensive care unit. Repeat EKG demonstrated a QRS of 156 ms, and a sodium bicarbonate infusion was initiated. The patient continued to have QRS prolongation for the next 8 days, reaching a peak of 172 ms 3 days postingestion. Despite aggressive treatment with sodium bicarbonate, there was persistent QRS prolongation; however, the patient did not have any dysrhythmias and remained hemodynamically stable. The patient was discharged 9 days postingestion when the QRS duration normalized to 82 ms. Genetic testing revealed that the patient was a CYP2D6 poor metabolizer. This case suggests that aripiprazole toxicity may possibly be associated with QRS prolongation without associated dysrhythmias or cardiovascular compromise. In addition, toxicity may be prolonged in patients who are CYP2D6 poor metabolizers.

In-situ nanoelectrospray for high-throughput screening of enzymes and real-time monitoring of reactions.

Science.gov (United States)

Yang, Yuhan; Han, Feifei; Ouyang, Jin; Zhao, Yunling; Han, Juan; Na, Na

2016-01-01

The in-situ and high-throughput evaluation of enzymes and real-time monitoring of enzyme catalyzed reactions in liquid phase is quite significant in the catalysis industry. In-situ nanoelectrospray, the direct sampling and ionization method for mass spectrometry, has been applied for high-throughput evaluation of enzymes, as well as the on-line monitoring of reactions. Simply inserting a capillary into a liquid system with high-voltage applied, analytes in liquid reaction system can be directly ionized at the capillary tip with small volume consumption. With no sample pre-treatment or injection procedure, different analytes such as saccharides, amino acids, alkaloids, peptides and proteins can be rapidly and directly extracted from liquid phase and ionized at the capillary tip. Taking irreversible transesterification reaction of vinyl acetate and ethanol as an example, this technique has been used for the high-throughput evaluation of enzymes, fast optimizations, as well as real-time monitoring of reaction catalyzed by different enzymes. In addition, it is even softer than traditional electrospray ionization. The present method can also be used for the monitoring of other homogenous and heterogeneous reactions in liquid phases, which will show potentials in the catalysis industry. Copyright © 2015 Elsevier B.V. All rights reserved.

Prolonging the viability of Lactobacillus plantarum through the addition of prebiotics into the medium.

Science.gov (United States)

Altieri, Clelia; Bevilacqua, Antonio; Sinigaglia, Milena

2011-08-01

This article reports on the effects of prebiotics on the growth/death kinetics, metabolism, and biomass production by 2 strains of Lactobacillus plantarum (c19 and DSMZ 2601, isolated from table olives and purchased from a Public Collection, respectively). The research was divided into 3 different steps, in order to highlight the optimal combination for cell viability and experiments were performed under the conditions of an accelerated shelf life test; thus, 3 combinations were pointed out (fructooligosaccharides [FOS], 5 g/L; glucose + inulin, 2.5 + 2.5 g/L; glucose + FOS, 2.5 + 2.5 g/L). A sample containing only glucose was used as control. The results highlighted that the 3 combinations aforementioned prolonged cell viability over the time both under low and high inoculum conditions (3 and 9 log CFU/mL, respectively); however, FOS alone caused a reduction of biomass production, even if cell number was not affected by this compound. Therefore, as a final result of this research, the combination glucose + FOS could be proposed as a suitable mean to achieve an optimal production of biomass and prolong cell viability over the time. Food producers require a prolonged viability of probiotic bacteria in functional foods; this goal is usually achieved by refrigeration. In this article, the prolongation of cell viability through the addition of prebiotics was proposed. © 2011 Institute of Food Technologists®

The Relationship between Cellular Phone Use, Performance, and Reaction Time among College Students: Implications for Cellular Phone Use while Driving

Science.gov (United States)

Szyfman, Adam; Wanner, Gregory; Spencer, Leslie

2003-01-01

Two studies were performed to determine the relationship between cellular phone use and either reaction time or performance among college students. In the first study 60 undergraduates completed a computerized reaction time test. Mean reaction times were significantly higher when participants were talking on a cellular phone, either handheld or on…

Opposite effects of sleep deprivation on the continuous reaction times in patients with liver cirrhosis and normal persons

DEFF Research Database (Denmark)

Lauridsen, Mette Munk; Frøjk, Jesper; de Muckadell, Ove B Schaffalitzky

2014-01-01

of this study was to determine if sleep deprivation influences the CRT test. Eighteen cirrhosis patients and 27 healthy persons were tested when rested and after one night's sleep deprivation. The patients filled out validated sleep quality questionnaires. Seven patients (38 %) had unstable reaction times (a...... CRTindex change in the other patients' reaction speed or stability. Seven patients (38 %) reported poor sleep that was not related to their CRT tests before...... or after the sleep deprivation. In the healthy participants, the sleep deprivation slowed their reaction times by 11 % (p persons (25 %) destabilized them. The acute sleep deprivation normalized or improved the reaction time stability of the patients with a CRTindex below 1.9 and had...

Chemical dynamics in the gas phase: Time-dependent quantum mechanics of chemical reactions

Energy Technology Data Exchange (ETDEWEB)

Gray, S.K. [Argonne National Laboratory, IL (United States)

1993-12-01

A major goal of this research is to obtain an understanding of the molecular reaction dynamics of three and four atom chemical reactions using numerically accurate quantum dynamics. This work involves: (i) the development and/or improvement of accurate quantum mechanical methods for the calculation and analysis of the properties of chemical reactions (e.g., rate constants and product distributions), and (ii) the determination of accurate dynamical results for selected chemical systems, which allow one to compare directly with experiment, determine the reliability of the underlying potential energy surfaces, and test the validity of approximate theories. This research emphasizes the use of recently developed time-dependent quantum mechanical methods, i.e. wave packet methods.

Effect of prolonged isothermal heat treatment on the mechanical behavior of advanced NANOBAIN steel

Science.gov (United States)

Avishan, Behzad

2017-09-01

The microstructural evolution and consequent changes in strength and ductility of advanced NANOBAIN steel during prolonged isothermal heat-treatment stages were investigated. The microstructure and mechanical properties of nanostructured bainite were not expected to be influenced by extending the heat-treatment time beyond the optimum value because of the autotempering phenomenon and high tempering resistance. However, experimental results indicated that the microstructure was thermodynamically unstable and that prolonged austempering resulted in carbon depletion from high-carbon retained austenite and carbide precipitations. Therefore, austenite became thermally less stable and partially transformed into martensite during cooling to room temperature. Prolonged austempering did not lead to the typical tempering sequence of bainite, and the sizes of the microstructural constituents were independent of the extended heat-treatment times. This independence, in turn, resulted in almost constant ultimate tensile strength values. However, microstructural variations enhanced the yield strength and the hardness of the material at extended isothermal heat-treatment stages. Finally, although microstructural changes decreased the total elongation and impact toughness, considerable combinations of mechanical properties could still be achieved.

The effects of reward and punishment on reaction times and autonomic activity in hyperactive and normal children.

Science.gov (United States)

Firestone, P; Douglas, V

1975-01-01

The performance of hyperactive and control children was compared on a delayed reaction time task under three reinforcement conditions: reward, punishment, and reward plus punishment. Hyperactives had slower and more variable reaction times, suggesting an attentional deficit. Although each of the three reinforcement conditons was successful in improving reaction times for both subject groups, reward led to a significant increase in impulsive responses in the hyperactive children. Autonomic data revealed that reward also increased arousal to a greater extent than punishment or reward plus punishment. Although resting skin conductance was not different in the two groups of subjects, hyperactives produced fewer specific autonomic responses to signal stimuli.

Characterizing Information Processing With a Mobile Device: Measurement of Simple and Choice Reaction Time.

Science.gov (United States)

Burke, Daniel; Linder, Susan; Hirsch, Joshua; Dey, Tanujit; Kana, Daniel; Ringenbach, Shannon; Schindler, David; Alberts, Jay

2017-10-01

Information processing is typically evaluated using simple reaction time (SRT) and choice reaction time (CRT) paradigms in which a specific response is initiated following a given stimulus. The measurement of reaction time (RT) has evolved from monitoring the timing of mechanical switches to computerized paradigms. The proliferation of mobile devices with touch screens makes them a natural next technological approach to assess information processing. The aims of this study were to determine the validity and reliability of using of a mobile device (Apple iPad or iTouch) to accurately measure RT. Sixty healthy young adults completed SRT and CRT tasks using a traditional test platform and mobile platforms on two occasions. The SRT was similar across test modality: 300, 287, and 280 milliseconds (ms) for the traditional, iPad, and iTouch, respectively. The CRT was similar within mobile devices, though slightly faster on the traditional: 359, 408, and 384 ms for traditional, iPad, and iTouch, respectively. Intraclass correlation coefficients ranged from 0.79 to 0.85 for SRT and from 0.75 to 0.83 for CRT. The similarity and reliability of SRT across platforms and consistency of SRT and CRT across test conditions indicate that mobile devices provide the next generation of assessment platforms for information processing.

Rapid quantification of semen hepatitis B virus DNA by real-time polymerase chain reaction

Science.gov (United States)

Qian, Wei-Ping; Tan, Yue-Qiu; Chen, Ying; Peng, Ying; Li, Zhi; Lu, Guang-Xiu; Lin, Marie C.; Kung, Hsiang-Fu; He, Ming-Ling; Shing, Li-Ka

2005-01-01

AIM: To examine the sensitivity and accuracy of real-time polymerase chain reaction (PCR) for the quantification of hepatitis B virus (HBV) DNA in semen. METHODS: Hepatitis B viral DNA was isolated from HBV carriers’ semen and sera using phenol extraction method and QIAamp DNA blood mini kit (Qiagen, Germany). HBV DNA was detected by conventional PCR and quantified by TaqMan technology-based real-time PCR (quantitative polymerase chain reaction (qPCR)). The detection threshold was 200 copies of HBV DNA for conventional PCR and 10 copies of HBV DNA for real time PCR per reaction. RESULTS: Both methods of phenol extraction and QIAamp DNA blood mini kit were suitable for isolating HBV DNA from semen. The value of the detection thresholds was 500 copies of HBV DNA per mL in the semen. The viral loads were 7.5 × 107 and 1.67 × 107 copies of HBV DNA per mL in two HBV infected patients’ sera, while 2.14 × 105 and 3.02 × 105 copies of HBV DNA per mL in the semen. CONCLUSION: Real-time PCR is a more sensitive and accurate method to detect and quantify HBV DNA in the semen. PMID:16149152

A parametric duration model of the reaction times of drivers distracted by mobile phone conversations.

Science.gov (United States)

Haque, Md Mazharul; Washington, Simon

2014-01-01

The use of mobile phones while driving is more prevalent among young drivers-a less experienced cohort with elevated crash risk. The objective of this study was to examine and better understand the reaction times of young drivers to a traffic event originating in their peripheral vision whilst engaged in a mobile phone conversation. The CARRS-Q advanced driving simulator was used to test a sample of young drivers on various simulated driving tasks, including an event that originated within the driver's peripheral vision, whereby a pedestrian enters a zebra crossing from a sidewalk. Thirty-two licensed drivers drove the simulator in three phone conditions: baseline (no phone conversation), hands-free and handheld. In addition to driving the simulator each participant completed questionnaires related to driver demographics, driving history, usage of mobile phones while driving, and general mobile phone usage history. The participants were 21-26 years old and split evenly by gender. Drivers' reaction times to a pedestrian in the zebra crossing were modelled using a parametric accelerated failure time (AFT) duration model with a Weibull distribution. Also tested where two different model specifications to account for the structured heterogeneity arising from the repeated measures experimental design. The Weibull AFT model with gamma heterogeneity was found to be the best fitting model and identified four significant variables influencing the reaction times, including phone condition, driver's age, license type (provisional license holder or not), and self-reported frequency of usage of handheld phones while driving. The reaction times of drivers were more than 40% longer in the distracted condition compared to baseline (not distracted). Moreover, the impairment of reaction times due to mobile phone conversations was almost double for provisional compared to open license holders. A reduction in the ability to detect traffic events in the periphery whilst distracted

Influence of reaction time on the structure of polyaniline synthesized on a pre-pilot scale

Directory of Open Access Journals (Sweden)

Maria Alice Carvalho Mazzeu

Full Text Available Abstract The aim of this work is to follow the structural variations of polyaniline (PAni obtained by chemical oxidation on a pre-pilot scale, with different reaction times. Synthesis of PAni is well known, but when it is carried out on a pre-pilot scale, several factors can lead to structural changes and understanding these changes is important to improve controls on the synthesis process. The polymers formed were characterized by spectroscopic techniques (Raman spectroscopy, Fourier Transform Infrared - FTIR and UV-Visible. Degree of oxidation and yield were calculated for each reaction time. The analysis by FTIR, the calculated degree of oxidation and the yield showed significant changes in polymer structure at reaction times of 65 and 80 min. This result was attributed to the excessive oxidation of PAni, with the breaking of its polymer chain. The changes observed in the structure of PAni gave subsidies to the optimization of the process of obtaining polyaniline by chemical synthesis.

Reaction times to weak test lights. [psychophysics biological model

Science.gov (United States)

Wandell, B. A.; Ahumada, P.; Welsh, D.

1984-01-01

Maloney and Wandell (1984) describe a model of the response of a single visual channel to weak test lights. The initial channel response is a linearly filtered version of the stimulus. The filter output is randomly sampled over time. Each time a sample occurs there is some probability increasing with the magnitude of the sampled response - that a discrete detection event is generated. Maloney and Wandell derive the statistics of the detection events. In this paper a test is conducted of the hypothesis that the reaction time responses to the presence of a weak test light are initiated at the first detection event. This makes it possible to extend the application of the model to lights that are slightly above threshold, but still within the linear operating range of the visual system. A parameter-free prediction of the model proposed by Maloney and Wandell for lights detected by this statistic is tested. The data are in agreement with the prediction.

Assumption-free analysis of quantitative real-time polymerase chain reaction (PCR) data

NARCIS (Netherlands)

Ramakers, Christian; Ruijter, Jan M.; Deprez, Ronald H. Lekanne; Moorman, Antoon F. M.

2003-01-01

Quantification of mRNAs using real-time polymerase chain reaction (PCR) by monitoring the product formation with the fluorescent dye SYBR Green I is being extensively used in neurosciences, developmental biology, and medical diagnostics. Most PCR data analysis procedures assume that the PCR

Inconsistency in reaction time across the life span.

Science.gov (United States)

Williams, Benjamin R; Hultsch, David F; Strauss, Esther H; Hunter, Michael A; Tannock, Rosemary

2005-01-01

Inconsistency in latency across trials of 2-choice reaction time data was analyzed in 273 participants ranging in age from 6 to 81 years. A U-shaped curve defined the relationship between age and inconsistency, with increases in age associated with lower inconsistency throughout childhood and higher inconsistency throughout adulthood. Differences in inconsistency were independent of practice, fatigue, and age-related differences in mean level of performance. Evidence for general and specific variability-producing processes was found in those aged less than 21 years, whereas only a specific process, such as attentional blocks, was evident for those 21 years and older. The findings highlight the importance of considering moment-to-moment changes in performance in psychological research. 2005 APA

The value of the Widal test in the diagnosis of Prolonged Septicemic Salmonellosis

Directory of Open Access Journals (Sweden)

José Roberto Lambertucci

1985-04-01

Full Text Available Twenty patients with prolonged septicemic salmonellosis (Group 1 and 20 with schistosomiasis mansoni (Group 2 were selected for this study. In both groups, the Widal test was done using antigens of the sample Ty 901 (S. typhi. The test was also applied in 6 group 1 patients with antigens prepared from salmonellae isolated from these patients (autoantigens. Titres over 1:200 were considered significant. Ten group 1 patients (50% were positive for antigen "H" and 5 (25% were positive for antigen "O". Three patients with negative "H" and "O" reactions became positive with high titres when using autoantigens. Two other cases maintained the same positive titres and one case showed a fourfold increase in titres when the test was done 'with antigens of the Salmonella isolated. The Widal test was positive in most patients infected with group D Salmonellae. Considering titres above 1:200, all cases were negative in Group 2. The authors conclude that the Widal test has low positivity in prolonged septicemic salmonellosis. The test may be valuable in the diagnosis of this disease when using S. paratyphi "A" and "B" antigens and a mixture of Salmonella antigens taken from other groups.

On null tests of time-reversal invariance in scattering and reactions

International Nuclear Information System (INIS)

Conzett, H.E.

1993-01-01

There have been suggestions in the literature, both recently and in the more distant past, that, in the lowest-order Born approximation, time-reversal (T)-odd experimental observables in certain reactions are required by T-symmetry to vanish. These observables are the final-state spin-correlation coefficient C xy in the reaction e + e - → τ + τ - and the target analysing power A oy in the inclusive process ep → eX with a polarized proton target. These assertions are in direct conflict with a theorem that states that there can be no null-test of T-symmetry in such processes; that is, T-symmetry does not require any single observable to vanish. This talk addresses the resolution of that conflict

Nuclear energy as a 'golden bridge'? Constitutional legal problems of the negotiation of the prolongation of the running time against skimming of profits; Kernenergie als 'goldene Bruecke'? Verfassungsrechtliche Probleme der Aushandlung von Laufzeitverlaengerungen gegen Gewinnabschoepfungen

Energy Technology Data Exchange (ETDEWEB)

Waldhoff, Christian; Aswege, Hanka von [Bonn Univ. (Germany). Lehrstuhl fuer Oeffentliches Recht

2010-07-15

The coalition agreement of Christian Demographic Union (CDU), Christian Social Union (CSU) and Free Democratic Party (FDP) from 26th October, 2009 characterizes the nuclear energy as a bridge technology. The coalition parties explain to prolong the running times of German nuclear power stations up to a reliable replacement by renewable energies. The conditions for the prolongation of the running times are to be regulated in agreement with energy supply companies. In the contribution under consideration, the authors report on the fiscal legal problems of the skimming of profits. Constitutional legal problems of the earmaking of a skimming of profits as well as a consensual agreement are discussed in this contribution. In the result, a financial constitutionally reliable way for the skimming of added profits due to prolongation of the running time is not evident. The legal earmaking of the duty advent for the promotion of renewable energies increases the constitutional doubts.

Collection of human reaction times and supporting health related data for analysis of cognitive and physical performance

Directory of Open Access Journals (Sweden)

Petr Brůha

2018-04-01

Full Text Available Smoking, excessive drinking, overeating and physical inactivity are well-established risk factors decreasing human physical performance. Moreover, epidemiological work has identified modifiable lifestyle factors, such as poor diet and physical and cognitive inactivity that are associated with the risk of reduced cognitive performance. Definition, collection and annotation of human reaction times and suitable health related data and metadata provides researchers with a necessary source for further analysis of human physical and cognitive performance. The collection of human reaction times and supporting health related data was obtained from two groups comprising together 349 people of all ages - the visitors of the Days of Science and Technology 2016 held on the Pilsen central square and members of the Mensa Czech Republic visiting the neuroinformatics lab at the University of West Bohemia. Each provided dataset contains a complete or partial set of data obtained from the following measurements: hands and legs reaction times, color vision, spirometry, electrocardiography, blood pressure, blood glucose, body proportions and flexibility. It also provides a sufficient set of metadata (age, gender and summary of the participant's current life style and health to allow researchers to perform further analysis. This article has two main aims. The first aim is to provide a well annotated collection of human reaction times and health related data that is suitable for further analysis of lifestyle and human cognitive and physical performance. This data collection is complemented with a preliminarily statistical evaluation. The second aim is to present a procedure of efficient acquisition of human reaction times and supporting health related data in non-lab and lab conditions. Keywords: Reaction time, Health related data, Cognitive and physical performance, Chronic disease, Data acquisition, Data collection, Software for data collection

Effects of Fatigue on Driving Safety: A Comparison of Brake Reaction Times in Night Float and Postcall Physicians in Training.

Science.gov (United States)

Talusan, Paul G; Long, Theodore; Halim, Andrea; Guliani, Laura; Carroll, Nicole; Reach, John

2014-12-01

Concerns about duty hour and resident safety have fostered discussion about postshift fatigue and driving impairment. We assessed how converting to a night float schedule for overnight coverage affected driving safety for trainees. Brake reaction times were measured for internal medicine and orthopaedic surgery resident volunteers after a traditional 28-hour call shift and after a night float shift. We conducted matched paired t tests of preshift and postshift reaction time means. Participants also completed the Epworth Sleepiness Scale pre- and postshift. From June to July 2013, we enrolled 58 interns and residents (28 orthopaedic surgery, 30 internal medicine). We included 24 (41%) trainees on night float rotations and 34 (59%) trainees on traditional 28-hour call shifts. For all residents on night float rotations, there was no significant difference pre- and postshift. An increase in reaction times was noted among trainees on 28-hour call rotations. This included no effect on reaction times for internal medicine trainees pre- and postshift, and an increase in reaction times for orthopaedic trainees. For both night float and traditional call groups, there were significant increases in the Epworth Sleepiness Scale. Trainees on traditional 28-hour call rotations had significantly worse postshift brake reaction times, whereas trainees on night float rotations had no difference. Orthopaedic trainees had significant differences in brake reaction times after a traditional call shift.

Marked QTc prolongation and Torsades de Pointes in patients with chronic inflammatory arthritis

Directory of Open Access Journals (Sweden)

Pietro Enea Lazzerini

2016-09-01

Full Text Available Mounting evidence indicates that in chronic inflammatory arthritis (CIA, QTc prolongation is frequent and correlates with systemic inflammatory activation. Notably, basic studies demonstrated that inflammatory cytokines induce profound changes in potassium and calcium channels resulting in a prolonging effect on cardiomyocyte action potential duration (APD, thus on the QT interval on the electrocardiogram. Moreover, it has been demonstrated that in RA patients the risk of SCD is significantly increased when compared to non-RA subjects. Conversely, to date no data are available about Torsades de Pointes (TdP prevalence in CIA, and the few case reported considered CIA only an incidental concomitant disease, not contributing factor to TdP development.We report three patients with active CIA developing marked QTc prolongation, in two cases complicated with TdP degenerating to cardiac arrest. In these patients, a blood sample was obtained within 24h from TdP/marked QTc prolongation occurrence and levels of IL-6, TNF-alpha and IL-1 were evaluated. In all three cases, IL-6 was markedly elevated, ~10 to 100 times more than reference values. Moreover, one patient also showed high circulating levels of TNF-alpha and IL-1. In conclusion, active CIA may represent a currently overlooked QT-prolonging risk factor, potentially contributing in the presence of other classical risk factors to TdP occurrence. In particular, a relevant role may be played by elevated circulating IL-6 levels via direct electrophysiological effects on the heart. This observation should be carefully kept in mind, particularly when recognizable risk factors are already present and/or the addition of QT-prolonging drugs is required.

Theoretical Time Dependent Thermal Neutron Spectra and Reaction Rates in H2O and D2O

International Nuclear Information System (INIS)

Purohit, S.N.

1966-04-01

The early theoretical and experimental time dependent neutron thermalization studies were limited to the study of the transient spectrum in the diffusion period. The recent experimental measurements of the time dependent thermal neutron spectra and reaction rates, for a number of moderators, have generated considerable interest in the study of the time dependent Boltzmann equation. In this paper we present detailed results for the time dependent spectra and the reaction rates for resonance detectors using several scattering models of H 2 O and D 2 O. This study has been undertaken in order to interpret the integral time dependent neutron thermalization experiments in liquid moderators which have been performed at the AB Atomenergi. The proton gas and the deuteron gas models are inadequate to explain the measured reaction rates in H 2 O and D 2 O. The bound models of Nelkin for H 2 O and of Butler for D 2 O give much better agreement with the experimental results than the gas models. Nevertheless, some disagreement between theoretical and experimental results still persists. This study also indicates that the bound model of Butler and the effective mass 3. 6 gas model of Brown and St. John give almost identical reaction rates. It is also surprising to note that the calculated reaction rate for Cd for the Butler model appears to be in better agreement with the experimental results of D 2 O than of the Nelkin model with H 2 O experiments. The present reaction rate studies are sensitive enough so as to distinguish between the gas model and the bound model of a moderator. However, to investigate the details of a scattering law (such as the effect of the hindered rotations in H 2 O and D 2 O and the weights of different dynamical modes) with the help of these studies would require further theoretical as well as experimental investigations. Theoretical results can be further improved by improving the source for thermal neutrons, the group structure and the scattering

Synthesis of ferrofluids based on cobalt ferrite nanoparticles: Influence of reaction time on structural, morphological and magnetic properties

Energy Technology Data Exchange (ETDEWEB)

Amirabadizadeh, Ahmad; Salighe, Zohre; Sarhaddi, Reza, E-mail: reza.sarhaddi@birjand.ac.ir; Lotfollahi, Zahra

2017-07-15

Highlights: • Ferrofluids based on cobalt ferrite nanoparticles were synthesized by co-precipitation method. • The crystallite and particle size of cobalt ferrite can be controlled effectively by reaction time. • The ferrofluids have lower values of saturation magnetization and coercivity as compared to nanoparticles. • By increasing the size of nanoparticles, the narrower and sharper spikes of ferrofluids are formed. - Abstract: In this work, for first time the ferrofluids based on the cobalt ferrite (CoFe{sub 2}O{sub 4}) nanoparticles were prepared by the co-precipitation method at different reaction times (0.5–6.5 h). Crystal structure, morphology and magnetic properties of the cobalt ferrite nanoparticles and the ferrofluids based on the nanoparticles were studied by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM). The XRD patterns of CoFe{sub 2}O{sub 4} nanoparticles synthesized at different reaction times indicated that all samples are single phase in accordance with inverse cubic spinel structure with space group Fd-3m, and no impurity phase was observed. By increasing the reaction time to 3.5 h, the lattice parameter and the average crystallites size increased and then afterwards decreased by increasing the reaction time. The microscopic studies indicated the formation of nanosized particles with nearly spherical in shape, whereas the average particle size for all samples is found to be less than 50 nm. The results of VSM also showed that the saturation magnetization and coercivity field of the cobalt ferrite nanoparticles and the ferrofluids were influenced by reaction time, whereas the ferrofluids have lower values of magnetic parameters than that of nanoparticles.

A novel approach to sports concussion assessment: Computerized multilimb reaction times and balance control testing.

Science.gov (United States)

Vartiainen, Matti V; Holm, Anu; Lukander, Jani; Lukander, Kristian; Koskinen, Sanna; Bornstein, Robert; Hokkanen, Laura

2016-01-01

Mild traumatic brain injuries (MTBI) or concussions often result in problems with attention, executive functions, and motor control. For better identification of these diverse problems, novel approaches integrating tests of cognitive and motor functioning are needed. The aim was to characterize minor changes in motor and cognitive performance after sports-related concussions with a novel test battery, including balance tests and a computerized multilimb reaction time test. The cognitive demands of the battery gradually increase from a simple stimulus response to a complex task requiring executive attention. A total of 113 male ice hockey players (mean age = 24.6 years, SD = 5.7) were assessed before a season. During the season, nine concussed players were retested within 36 hours, four to six days after the concussion, and after the season. A control group of seven nonconcussed players from the same pool of players with comparable demographics were retested after the season. Performance was measured using a balance test and the Motor Cognitive Test battery (MotCoTe) with multilimb responses in simple reaction, choice reaction, inhibition, and conflict resolution conditions. The performance of the concussed group declined at the postconcussion assessment compared to both the baseline measurement and the nonconcussed controls. Significant changes were observed in the concussed group for the multilimb choice reaction and inhibition tests. Tapping and balance showed a similar trend, but no statistically significant difference in performance. In sports-related concussions, complex motor tests can be valuable additions in assessing the outcome and recovery. In the current study, using subtasks with varying cognitive demands, it was shown that while simple motor performance was largely unaffected, the more complex tasks induced impaired reaction times for the concussed subjects. The increased reaction times may reflect the disruption of complex and integrative cognitive

Exercise improves gait, reaction time and postural stability in older adults with type 2 diabetes and neuropathy.

Science.gov (United States)

Morrison, Steven; Colberg, Sheri R; Parson, Henri K; Vinik, Aaron I

2014-01-01

For older adults with type 2 diabetes (T2DM), declines in balance and walking ability are risk factors for falls, and peripheral neuropathy magnifies this risk. Exercise training may improve balance, gait and reduce the risk of falling. This study investigated the effects of 12weeks of aerobic exercise training on walking, balance, reaction time and falls risk metrics in older T2DM individuals with/without peripheral neuropathy. Adults with T2DM, 21 without (DM; age 58.7±1.7years) and 16 with neuropathy (DM-PN; age 58.9±1.9years), engaged in either moderate or intense supervised exercise training thrice-weekly for 12weeks. Pre/post-training assessments included falls risk (using the physiological profile assessment), standing balance, walking ability and hand/foot simple reaction time. Pre-training, the DM-PN group had higher falls risk, slower (hand) reaction times (232 vs. 219ms), walked at a slower speed (108 vs. 113cm/s) with shorter strides compared to the DM group. Following training, improvements in hand/foot reaction times and faster walking speed were seen for both groups. While falls risk was not significantly reduced, the observed changes in gait, reaction time and balance metrics suggest that aerobic exercise of varying intensities is beneficial for improving dynamic postural control in older T2DM adults with/without neuropathy. Copyright © 2014 Elsevier Inc. All rights reserved.

Changes in tumor cell response due to prolonged dose delivery times in fractionated radiation therapy

International Nuclear Information System (INIS)

Paganetti, Harald

2005-01-01

Purpose: Dynamic radiation therapy, such as intensity-modulated radiation therapy, delivers more complex treatment fields than conventional techniques. The increased complexity causes longer dose delivery times for each fraction. The cellular damage after a full treatment may depend on the dose rate, because sublethal radiation damage can be repaired more efficiently during prolonged dose delivery. The goal of this study was to investigate the significance of this effect in fractionated radiation therapy. Methods and Materials: The lethal/potentially lethal model was used to calculate lesion induction rates for repairable and nonrepairable lesions. Dose rate effects were analyzed for 9 different cell lines (8 human tumor xenografts and a C3H10T1/2 cell line). The effects of single-fraction as well as fractionated irradiation for different dose rates were studied. Results: Significant differences can be seen for dose rates lower than about 0.1 Gy/min for all cell lines considered. For 60 Gy delivered in 30 fractions, the equivalent dose is reduced by between 1.3% and 12% comparing 2 Gy delivery over 30 min per fraction with 2 Gy delivery over 1 min per fraction. The effect is higher for higher doses per fraction. Furthermore, the results show that dose rate effects do not show a simple correlation with the α/β ratio for ratios between 3 Gy and 31 Gy. Conclusions: If the total dose delivery time for a treatment fraction in radiation therapy increases to about 20 min, a correction for dose rate effects may have to be considered in treatment planning. Adjustments in effective dose may be necessary when comparing intensity-modulated radiation therapy with conventional treatment plans

Lipase-catalyzed glycerolysis of fats and oils in ionic liquids: a further study on the reaction system

DEFF Research Database (Denmark)

Guo, Zheng; Xu, Xuebing

2006-01-01

Candida antarctica lipase B-catalyzed glycerolysis of sunflower oil in a tetraammonium-based ionic liquid (IL) was studied to elucidate its distinct characteristics and to evaluate the contributions of important parameters. Mass transfer limitations and occurring partial phase separation were found...... and enzyme loading study. Interestingly, increasing water activity resulted in a decreasing initial reaction rate and a prolonged induction period, which possibly resulted from an elevated solvation barrier and the phase separation at higher water content. Studies on thermodynamics of glycerolysis show......) equation, and the viscosity of the mixture is strongly agitation-dependent. A comparable diffusion time constant of the oil molecule in the IL to that of the reaction shows that the glycerolysis in the IL is controlled both diffusionally and kinetically, as experimentally verified by agitation effect...

Combined effect of whole-body vibration and ambient lighting on human discomfort, heart rate, and reaction time.

Science.gov (United States)

Monazzam, Mohammad Reza; Shoja, Esmaeil; Zakerian, Seyed Abolfazl; Foroushani, Abbas Rahimi; Shoja, Mohsen; Gharaee, Masoumeh; Asgari, Amin

2018-03-12

This study aimed to investigate the effect of whole-body vibration and ambient lighting, as well as their combined effect on human discomfort, heart rate, and reaction time in laboratory conditions. 44 men were recruited with an average age of 25.4 ± 1.9 years. Each participant was subjected to 12 experimental steps, each step lasting five minutes for four different vibration accelerations in X, Y, and Z axes at a fixed frequency; three different lighting intensities of 50, 500, and 1000 lx were also considered. At each step, a visual computerized reaction test was taken from subjects and their heart rate recorded by pulse oximeter. In addition, the discomfort rate of subjects was measured using Borg scale. Increasing vibration acceleration significantly increased the discomfort rate and heart beat but not the reaction time. Lack of lighting caused more discomfort in the subjects, but there was no significant correlation between lighting intensity with heart rate and reaction time. The results also showed that the combined effect of vibration and lighting had no significant effect on any of the discomfort, heart rate, and reaction time variables. Whole-body vibration is an important factor in the development of human subjective and physiological reactions compared to lighting. Therefore, consideration of the level of vibration to which an individual is exposed in workplaces subject to vibration plays an important role in reducing the level of human discomfort, but its interaction with ambient lighting does not have a significant effect on human subjective and physiological responses.

Extensive deep vein thrombosis following prolonged gaming (‘gamer’s thrombosis’): a case report

Science.gov (United States)

2013-01-01

Introduction The average time spent playing video games is increasing. Prolonged immobility associated with gaming may therefore be an important risk factor for venous thromboembolism. We report a case of deep vein thrombosis associated with prolonged playing of PlayStation® games. Case presentation A 31-year-old Caucasian man, an exterior painter, presented with a three-day history of left leg pain and swelling after playing PlayStation® games for almost eight hours a day for four consecutive days. Doppler ultrasound of the left leg confirmed extensive left leg deep venous thrombosis requiring thrombolysis and anticoagulation. Conclusions Video gaming should be considered a risk factor for venous thromboembolism. Further studies are needed to estimate the degree of risk associated with prolonged periods of playing video games, and education for preventing venous thrombosis should be provided to gamers. PMID:24192285

Pharmacometabolomic approach to predict QT prolongation in guinea pigs.

Directory of Open Access Journals (Sweden)

Jeonghyeon Park

Full Text Available Drug-induced torsades de pointes (TdP, a life-threatening arrhythmia associated with prolongation of the QT interval, has been a significant reason for withdrawal of several medicines from the market. Prolongation of the QT interval is considered as the best biomarker for predicting the torsadogenic risk of a new chemical entity. Because of the difficulty assessing the risk for TdP during drug development, we evaluated the metabolic phenotype for predicting QT prolongation induced by sparfloxacin, and elucidated the metabolic pathway related to the QT prolongation. We performed electrocardiography analysis and liquid chromatography-mass spectroscopy-based metabolic profiling of plasma samples obtained from 15 guinea pigs after administration of sparfloxacin at doses of 33.3, 100, and 300 mg/kg. Principal component analysis and partial least squares modelling were conducted to select the metabolites that substantially contributed to the prediction of QT prolongation. QTc increased significantly with increasing dose (r = 0.93. From the PLS analysis, the key metabolites that showed the highest variable importance in the projection values (>1.5 were selected, identified, and used to determine the metabolic network. In particular, cytidine-5'-diphosphate (CDP, deoxycorticosterone, L-aspartic acid and stearic acid were found to be final metabolomic phenotypes for the prediction of QT prolongation. Metabolomic phenotypes for predicting drug-induced QT prolongation of sparfloxacin were developed and can be applied to cardiac toxicity screening of other drugs. In addition, this integrative pharmacometabolomic approach would serve as a good tool for predicting pharmacodynamic or toxicological effects caused by changes in dose.

Intraindividual Stepping Reaction Time Variability Predicts Falls in Older Adults With Mild Cognitive Impairment.

Science.gov (United States)

Bunce, David; Haynes, Becky I; Lord, Stephen R; Gschwind, Yves J; Kochan, Nicole A; Reppermund, Simone; Brodaty, Henry; Sachdev, Perminder S; Delbaere, Kim

2017-06-01

Reaction time measures have considerable potential to aid neuropsychological assessment in a variety of health care settings. One such measure, the intraindividual reaction time variability (IIV), is of particular interest as it is thought to reflect neurobiological disturbance. IIV is associated with a variety of age-related neurological disorders, as well as gait impairment and future falls in older adults. However, although persons diagnosed with Mild Cognitive Impairment (MCI) are at high risk of falling, the association between IIV and prospective falls is unknown. We conducted a longitudinal cohort study in cognitively intact (n = 271) and MCI (n = 154) community-dwelling adults aged 70-90 years. IIV was assessed through a variety of measures including simple and choice hand reaction time and choice stepping reaction time tasks (CSRT), the latter administered as a single task and also with a secondary working memory task. Logistic regression did not show an association between IIV on the hand-held tasks and falls. Greater IIV in both CSRT tasks, however, did significantly increase the risk of future falls. This effect was specific to the MCI group, with a stronger effect in persons exhibiting gait, posture, or physiological impairment. The findings suggest that increased stepping IIV may indicate compromised neural circuitry involved in executive function, gait, and posture in persons with MCI increasing their risk of falling. IIV measures have potential to assess neurobiological disturbance underlying physical and cognitive dysfunction in old age, and aid fall risk assessment and routine care in community and health care settings. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Prolonged transition time between colostrum and mature milk in a bear, the giant panda, Ailuropoda melanoleuca

OpenAIRE

Griffiths, Katharine; Rong, Hou; Wang, Hairui; Zhang, Zhihe; Zhang, Tong; Watson, David G.; Burchmore, Richard; Loeffler, I.Kati; Kennedy, Malcolm

2015-01-01

Bears produce the most altricial neonates of any placental mammal. We hypothesized that the transition from colostrum to mature milk in bears reflects a temporal and biochemical adaptation for altricial development and immune protection. Comparison of bear milks with milks of other eutherians yielded distinctive protein profiles. Proteomic and metabolomic analysis of serial milk samples collected from six giant pandas showed a prolonged transition from colostrum to main-phase lactation over a...

On the use of adjustable distraction as a measure to determine sustained attention during movie clips

DEFF Research Database (Denmark)

Nordahl, Rolf; Korsgaard, Dannie

2009-01-01

Secondary task reaction time has been applied to measure the cognitive effects of movies, but has generally not produced convincing results when utilized to measure presence. We hypothesize that mixed results could be due to factors which prolong simple reaction time. This paper seeks to investig......Secondary task reaction time has been applied to measure the cognitive effects of movies, but has generally not produced convincing results when utilized to measure presence. We hypothesize that mixed results could be due to factors which prolong simple reaction time. This paper seeks...

Topical Drug Formulations for Prolonged Corneal Anesthesia

Science.gov (United States)

Wang, Liqiang; Shankarappa, Sahadev A.; Tong, Rong; Ciolino, Joseph B.; Tsui, Jonathan H.; Chiang, Homer H.; Kohane, Daniel S.

2013-01-01

Purpose Ocular local anesthetics (OLA’s) currently used in routine clinical practice for corneal anesthesia are short acting and their ability to delay corneal healing makes them unsuitable for long-term use. In this study, we examined the effect on the duration of corneal anesthesia of the site-1 sodium channel blocker tetrodotoxin (TTX), applied with either proparacaine or the chemical permeation enhancer OTAB. The effect of test solutions on corneal healing was also studied. Methods Solutions of TTX, proparacaine, and OTAB, singly or in combination were applied topically to the rat cornea. The blink response, an indirect measure of corneal sensitivity, was recorded using a Cochet-Bonnet esthesiometer, and the duration of corneal anesthesia calculated. The effect of test compounds on the rate of corneal epithelialization was studied in vivo following corneal debridement. Results Combination of TTX and proparacaine resulted in corneal anesthesia that was 8–10 times longer in duration than that from either drug administered alone, while OTAB did not prolong anesthesia. The rate of corneal healing was moderately delayed following co-administration of TTX and proparacaine. Conclusion Co-administration of TTX and proparacaine significantly prolonged corneal anesthesia but in view of delayed corneal re-epithelialization, caution is suggested in use of the combination. PMID:23615270

Illumination of Nanoliter-NMR Spectroscopy Chips for Real-Time Photochemical Reaction Monitoring

NARCIS (Netherlands)

Gomez, M.V.; Juan, Alberto; Jiménez-Márquez, Francisco; La Hoz, De Antonio; Velders, Aldrik H.

2018-01-01

We report the use of a small-volume nuclear-magnetic-resonance (NMR)-spectroscopy device with integrated fiber-optics for the real-time detection of UV-vis-light-assisted chemical reactions. An optical fiber is used to guide the light from LEDs or a laser diode positioned safely outside the magnet

DHA- RICH FISH OIL IMPROVES COMPLEX REACTION TIME IN FEMALE ELITE SOCCER PLAYERS

Directory of Open Access Journals (Sweden)

José F. Guzmán

2011-06-01

Full Text Available Omega-3 fatty acids (n-3 has shown to improve neuromotor function. This study examined the effects of docosahexaenoic acid (DHA on complex reaction time, precision and efficiency, in female elite soccer players. 24 players from two Spanish female soccer Super League teams were randomly selected and assigned to two experimental groups, then administered, in a double-blind manner, 3.5 g·day-1 of either DHA-rich fish oil (FO =12 or olive oil (OO = 12 over 4 weeks of training. Two measurements (pre- and post-treatment of complex reaction time and precision were taken. Participants had to press different buttons and pedals with left and right hands and feet, or stop responding, according to visual and auditory stimuli. Multivariate analysis of variance displayed an interaction between supplement administration (pre/post and experimental group (FO/OO on complex reaction time (FO pre = 0.713 ± 0.142 ms, FO post = 0.623 ± 0.109 ms, OO pre = 0.682 ± 1.132 ms, OO post = 0.715 ± 0.159 ms; p = 0.004 and efficiency (FO pre = 40.88 ± 17.41, FO post = 57.12 ± 11.05, OO pre = 49.52 ± 14.63, OO post = 49. 50 ± 11.01; p = 0.003. It was concluded that after 4 weeks of supplementation with FO, there was a significant improvement in the neuromotor function of female elite soccer players

RD50 Prolongation Request 2018

CERN Document Server

Casse, Gianluigi

2018-01-01

With this document, we request the prolongation of the CERN RD50 research program for 5 years. A very brief historical review of the RD50 research program since the RD50 project approval by the Research Board in the year 2002 is presented and the biggest RD50 achievements are highlighted. The present composition of the collaboration, its organizational structure, and the research methodology are described. The role of RD50 in the present various upgrade and research programs of the LHC Experiments community is given and the overall work plan explained. Finally, a detailed 5-years work program with precise milestones and deliverables for the various research activities is presented. We conclude with our prolongation request towards the LHCC.

High-dose radiation therapy alone for inoperable non-small cell lung cancer. Experience with prolonged overall treatment times

International Nuclear Information System (INIS)

Willers, H.; Wuerschmidt, F.; Buenemann, H.; Heilmann, H.P.

1998-01-01

The purpose of this study was to determine the impact of overall treatment time on long-term survival after high-dose radiation therapy alone for inoperable non-small cell lung cancer (NSCLC). Between 1978 and 1990, 229 patients with stage I-III disease and Karnofsky Performance Scores of 80-100 received a conventionally fractionated total dose of 70 Gy through a split-course technique. After a first treatment course of 40 or 50 Gy, a rest aging was performed and only patients without any contraindications, such as newly diagnosed distant metastases or serious deterioration of performance status, were given a second course. In 83% of patients this break lasted for 4-6 weeks. Overall treatment time ranged between 7 and 24 weeks (median 12 weeks). Median follow-up time was 6.6 years (range 4.0-9.3 years). Actuarial overall survival rates at 2 and 5 years were 28% and 7% respectively. Complete radiological tumor response was observed in 31% of patients, and was found to be the strongest positive predictor of survival with 2- and 5-year rates of 50% and 12% respectively compared with 17% and 4% for patients without complete response. Treatment duration was not found to be a significant prognostic factor in univariate or multivariate analysis. For overall treatment times of 7-11 weeks (n=50), 12 weeks (n=79) and >12 weeks (n=100), 5-year survival was 4%, 6%, and 8%, respectively (p=0.6). To conclude, in our experience and in contrast to other studies, prolonged overall treatment times in radiation therapy alone for inoperable NSCLC had no negative impact on long-term survival. It is hypothesized that accelerated tumor cell repopulation is absent in a significant number of these patients with the time-factor playing no apparent role for outcome of treatment. (orig.)

Prolonged Remission in Neuromyelitis Optica Following Cessation of Rituximab Treatment.

Science.gov (United States)

Weinfurtner, Kelley; Graves, Jennifer; Ness, Jayne; Krupp, Lauren; Milazzo, Maria; Waubant, Emmanuelle

2015-09-01

Neuromyelitis optica is an autoimmune disease characterized by acute episodes of transverse myelitis and optic neuritis. Several small, open-label studies suggest rituximab, a monoclonal antibody against CD20, prevents relapses in neuromyelitis optica; however, there is little consensus on timing or duration of treatment. Here we report four patients with severe relapsing neuromyelitis optica who were stabilized on rituximab and, after discontinuing treatment, continued to experience prolonged remission of their disease. Remission ranged from 4.5 to 10.5 years total, including 3 to 9 years off all therapies. The patients had sustained clinical responses despite normal B-lymphocyte levels and, in at least 2 patients, continued seropositivity for aquaporin-4 antibodies. These cases suggest that rituximab may induce prolonged remission in certain neuromyelitis optica patients, and they highlight the need for further elucidation of rituximab's mechanism in neuromyelitis optica. © The Author(s) 2014.

Atraumatic femoral neck fracture secondary to prolonged lactation induced osteomalacia

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Dhammapal Sahebrao Bhamare

2013-01-01

Full Text Available Presenting a case of atraumatic fracture neck femur secondary to 2 years of prolonged lactation. A 26-year-old lactating mother presented with pain in left hip from last 12 months. She was apparently alright before and during pregnancy. Plain radiograph showed a complete undisplaced fracture of femoral neck. Osteomalacia was diagnosed by radiological and serological investigations. The fracture was fixed using AO type cannulated cancellous screws. The fracture showed good clinical and radiological union at 3 months. Literature review shows that this is a first case of atraumatic fracture of neck femur due to prolonged lactational osteomalacia. It showed that even apparently healthy Indians are susceptible to osteomalacia, more so during pregnancy and lactation and can be presented as atraumatic fracture. Although considered relatively stable, a compression type incomplete fracture neck femur may progress to a complete fracture if not treated in time.

Visual but not motor processes predict simple visuomotor reaction time of badminton players.

Science.gov (United States)

Hülsdünker, Thorben; Strüder, Heiko K; Mierau, Andreas

2018-03-01

The athlete's brain exhibits significant functional adaptations that facilitate visuomotor reaction performance. However, it is currently unclear if the same neurophysiological processes that differentiate athletes from non-athletes also determine performance within a homogeneous group of athletes. This information can provide valuable help for athletes and coaches aiming to optimize existing training regimes. Therefore, this study aimed to identify the neurophysiological correlates of visuomotor reaction performance in a group of skilled athletes. In 36 skilled badminton athletes, electroencephalography (EEG) was used to investigate pattern reversal and motion onset visual-evoked potentials (VEPs) as well as visuomotor reaction time (VMRT) during a simple reaction task. Stimulus-locked and response-locked event-related potentials (ERPs) in visual and motor regions as well as the onset of muscle activation (EMG onset) were determined. Correlation and multiple regression analyses identified the neurophysiological parameters predicting EMG onset and VMRT. For pattern reversal stimuli, the P100 latency and age best predicted EMG onset (r = 0.43; p = .003) and VMRT (r = 0.62; p = .001). In the motion onset experiment, EMG onset (r = 0.80; p badminton players while motor-related processes, although differentiating athletes from non-athletes, are not associated simple with visuomotor reaction performance.

Type I photosensitized reactions of oxopurines. Kinetics and thermodynamics of the reaction with triplet benzophenone by time-resolved photoacoustic spectroscopy

Science.gov (United States)

Murgida, Daniel H.; Erra Balsells, Rosa; Crippa, Pier Raimondo; Viappiani, Cristiano

1998-09-01

Benzophenone photosensitized reactions of caffeine, theophylline and theobromine were investigated in acetonitrile by time-resolved laser-induced photoacoustics. In the three cases global quenching rate constants of triplet benzophenone were measured as a function of temperature and it was observed that this is a non-activated process. Besides, for theobromine and theophylline heats for NH hydrogen abstraction reactions were determined. In agreement with semiempirical calculation predictions, hydrogen abstraction is thermodynamically more favorable and faster for theophylline (Δ H=-265 kJ mol -1, kr=9.6×10 8 M -1 s -1) than for theobromine (Δ H=-168 kJ mol -1, kr=3.7×10 8 M -1 s -1).

Brain mapping after prolonged cycling and during recovery in the heat.

Science.gov (United States)

De Pauw, Kevin; Roelands, Bart; Marusic, Uros; Tellez, Helio Fernandez; Knaepen, Kristel; Meeusen, Romain

2013-11-01

The aim of this study was to determine the effect of prolonged intensive cycling and postexercise recovery in the heat on brain sources of altered brain oscillations. After a max test and familiarization trial, nine trained male subjects (23 ± 3 yr; maximal oxygen uptake = 62.1 ± 5.3 ml·min(-1)·kg(-1)) performed three experimental trials in the heat (30°C; relative humidity 43.7 ± 5.6%). Each trial consisted of two exercise tasks separated by 1 h. The first was a 60-min constant-load trial, followed by a 30-min simulated time trial (TT1). The second comprised a 12-min simulated time trial (TT2). After TT1, active recovery (AR), passive rest (PR), or cold water immersion (CWI) was applied for 15 min. Electroencephalography was measured at baseline and during postexercise recovery. Standardized low-resolution brain electromagnetic tomography was applied to accurately pinpoint and localize altered electrical neuronal activity. After CWI, PR and AR subjects completed TT2 in 761 ± 42, 791 ± 76, and 794 ± 62 s, respectively. A prolonged intensive cycling performance in the heat decreased β activity across the whole brain. Postexercise AR and PR elicited no significant electrocortical differences, whereas CWI induced significantly increased β3 activity in Brodmann areas (BA) 13 (posterior margin of insular cortex) and BA 40 (supramarginal gyrus). Self-paced prolonged exercise in the heat seems to decrease β activity, hence representing decreased arousal. Postexercise CWI increased β3 activity at BA 13 and 40, brain areas involved in somatosensory information processing.

Fermionic covariant prolongation structure theory for supernonlinear evolution equation

International Nuclear Information System (INIS)

Cheng Jipeng; Wang Shikun; Wu Ke; Zhao Weizhong

2010-01-01

We investigate the superprincipal bundle and its associated superbundle. The super(nonlinear)connection on the superfiber bundle is constructed. Then by means of the connection theory, we establish the fermionic covariant prolongation structure theory of the supernonlinear evolution equation. In this geometry theory, the fermionic covariant fundamental equations determining the prolongation structure are presented. As an example, the supernonlinear Schroedinger equation is analyzed in the framework of this fermionic covariant prolongation structure theory. We obtain its Lax pairs and Baecklund transformation.

Research of influence of time of reaction of the driver on the calculation of the capacity of the highway

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Anastasiya SHEVTSOVA

2015-09-01

Full Text Available In the work we performed a review of studies of foreign scholars on changing the reaction time of the driver depending on various road conditions, namely the change in the response time when using the traffic light regulation. Earlier by the authors of this article have already been carried out research in the field of throughput of a site of a highway with traffic regulation, which showed that this value depends on the time of reaction of the driver. In this article the estimation of how much bandwidth the highway using different result obtained in the course of analysis, time value of reaction of the driver and is a direct correlation bandwidth from the time of reaction of the driver. The values obtained allow to conclude that taking into account the psycho-physiological characteristics of drivers (response time will have a significant impact on the throughput and the various methods of organization and reorganization of sections of the road network, implementation of which is used investigated the amount of bandwidth.

Inflammation and prolonged QT time: results from the Cardiovascular Disease, Living and Ageing in Halle (CARLA study.

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Daniel Medenwald

Full Text Available Previous research found an association of CRP with QT time in population based samples. Even more, there is evidence of a substantial involvement of the tumor necrosis factor-alpha system in the pathophysiology of cardiac arrhythmia, while the role of Interleukin 6 remains inconclusive.To determine the association between inflammation with an abnormally prolonged QT-time (APQT in men and women of the elderly general population.Data descend from the baseline examination of the prospective, population-based Cardiovascular Disease, Living and Ageing in Halle (CARLA Study. After exclusion of subjects with atrial fibrillation and missing ECG recording the final study cohort consisted of 919 men and 797 women. Blood parameters of inflammation were the soluble TNF-Receptor 1 (sTNF-R1, the high-sensitive C-reactive protein (hsCRP, and Interleukin 6 (IL-6. In accordance with major cardiologic societies we defined an APQT above a QT time of 460 ms in women and 450 ms in men. Effect sizes and the corresponding 95% confidence intervals (CI were estimated by performing multiple linear and logistic regression analyses including the analysis of sex differences by interaction terms.After covariate adjustment we found an odds ratio (OR of 1.89 (95% CI: 1.13, 3.17 per 1000 pg/mL increase of sTNF-R1 in women, and 0.74 (95% CI: 0.48, 1.15 in men. In the covariate adjusted linear regression sTNF-R1 was again positively associated with QT time in women (5.75 ms per 1000 pg/mL, 95% CI: 1.32, 10.18, but not in men. Taking possible confounders into account IL-6 and hsCRP were not significantly related to APQT in both sexes.Our findings from cross-sectional analyses give evidence for an involvement of TNF-alpha in the pathology of APQT in women.

Prolonged Intermittent Renal Replacement Therapy.

Science.gov (United States)

Edrees, Fahad; Li, Tingting; Vijayan, Anitha

2016-05-01

Prolonged intermittent renal replacement therapy (PIRRT) is becoming an increasingly popular alternative to continuous renal replacement therapy in critically ill patients with acute kidney injury. There are significant practice variations in the provision of PIRRT across institutions, with respect to prescription, technology, and delivery of therapy. Clinical trials have generally demonstrated that PIRRT is non-inferior to continuous renal replacement therapy regarding patient outcomes. PIRRT offers cost-effective renal replacement therapy along with other advantages such as early patient mobilization and decreased nursing time. However, due to lack of standardization of the procedure, PIRRT still poses significant challenges, especially pertaining to appropriate drug dosing. Future guidelines and clinical trials should work toward developing consensus definitions for PIRRT and ensure optimal delivery of therapy. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

A reaction time experiment on adult attachment: The development of a measure for neurophysiological settings

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Theresia Wichmann

2016-11-01

Full Text Available In the last decades, there has been an increase of experimental research on automatic unconscious processes concerning the evaluation of the self and others. Previous research investigated implicit aspects of romantic attachment using self-report measures as explicit instruments for assessing attachment style. There is a lack of experimental procedures feasible for neurobiological settings. We developed a reaction time experiment (RT using a narrative attachment measure with an implicit nature and were interested to capture automatic processes, when the individuals’ attachment system is activated. We aimed to combine attachment methodology with knowledge from implicit measures by using a decision reaction time paradigm. This should serve as a means to capture implicit aspects of attachment. This experiment evaluated participants’ response to prototypic attachment sentences in association with their own attachment classification, measured with the Adult Attachment Projective Picture System (AAP.First the AAP was administered as the standardized interview procedure to 30 healthy participants, which were classified into a secure or insecure group. In the following experimental session, both experimenter and participants were blind with respect to classifications. 128 prototypically secure or insecure sentences related to the 8 pictures of the AAP were presented to the participants. Their response and reaction times were recorded. Based on the response (accept, reject a continuous security scale was defined. Both the AAP classification and security scale were related to the reaction times. Differentiated study hypotheses were confirmed for insecure sentences, which were accepted faster by participants from the insecure attachment group (or with lower security scale, and rejected faster by participants form secure attachment group (or with higher security scale. The elaborating unconscious processes were more activated by insecure sentences with

Effect of reaction time on structural, morphology and optical properties of ZnO nanoflakes prepared by chemical bath deposition method

Energy Technology Data Exchange (ETDEWEB)

Molefe, F.V.; Koao, L.F., E-mail: koaolf@qwa.ufs.ac.za; Dolo, J.J.; Dejene, B.F.

2014-04-15

ZnO nanoflakes have been successfully synthesized by the chemical bath deposition (CBD) method for different reaction times. X-ray diffraction (XRD) results confirm the initial formation of the cubic ZnO structure. However, increasing the reaction time resulted into the emergence of the well-known hexagonal wurtzite structure of ZnO. Scanning electron microscopy images showed the presence of agglomerated nanoflakes. The morphology was found not to depend on synthesis time. UV–vis spectra showed a partially increase in the percentage reflectance and the absorption edges red shifted to the higher wavelength with an increase in synthesis time. The highest band gap energy was obtained for ZnO synthesized for 1 min, with its estimated band gap energy of 3.91±0.08 eV. The estimated band gap decreased with an increase in the reaction time. The photoluminescent intensity of the emission peak at 473 nm decreased with an increase in reaction time.

Entropy-based critical reaction time for mixing-controlled reactive transport

DEFF Research Database (Denmark)

Chiogna, Gabriele; Rolle, Massimo

2017-01-01

Entropy-based metrics, such as the dilution index, have been proposed to quantify dilution and reactive mixing in solute transport problems. In this work, we derive the transient advection dispersion equation for the entropy density of a reactive plume. We restrict our analysis to the case where...... the concentration distribution of the transported species is Gaussian and we observe that, even in case of an instantaneous complete bimolecular reaction, dilution caused by dispersive processes dominates the entropy balance at early times and results in the net increase of the entropy density of a reactive species...

Considerations for the independent reaction times and step-by-step methods for radiation chemistry simulations

Science.gov (United States)

Plante, Ianik; Devroye, Luc

2017-10-01

Ionizing radiation interacts with the water molecules of the tissues mostly by ionizations and excitations, which result in the formation of the radiation track structure and the creation of radiolytic species such as H.,.OH, H2, H2O2, and e-aq. After their creation, these species diffuse and may chemically react with the neighboring species and with the molecules of the medium. Therefore radiation chemistry is of great importance in radiation biology. As the chemical species are not distributed homogeneously, the use of conventional models of homogeneous reactions cannot completely describe the reaction kinetics of the particles. Actually, many simulations of radiation chemistry are done using the Independent Reaction Time (IRT) method, which is a very fast technique to calculate radiochemical yields but which do not calculate the positions of the radiolytic species as a function of time. Step-by-step (SBS) methods, which are able to provide such information, have been used only sparsely because these are time-consuming in terms of calculation. Recent improvements in computer performance now allow the regular use of the SBS method in radiation chemistry. The SBS and IRT methods are both based on the Green's functions of the diffusion equation (GFDE). In this paper, several sampling algorithms of the GFDE and for the IRT method are presented. We show that the IRT and SBS methods are exactly equivalent for 2-particles systems for diffusion and partially diffusion-controlled reactions between non-interacting particles. We also show that the results obtained with the SBS simulation method with periodic boundary conditions are in agreement with the predictions by classical reaction kinetics theory, which is an important step towards using this method for modelling of biochemical networks and metabolic pathways involved in oxidative stress. Finally, the first simulation results obtained with the code RITRACKS (Relativistic Ion Tracks) are presented.

Neural network approach to time-dependent dividing surfaces in classical reaction dynamics

Science.gov (United States)

Schraft, Philippe; Junginger, Andrej; Feldmaier, Matthias; Bardakcioglu, Robin; Main, Jörg; Wunner, Günter; Hernandez, Rigoberto

2018-04-01

In a dynamical system, the transition between reactants and products is typically mediated by an energy barrier whose properties determine the corresponding pathways and rates. The latter is the flux through a dividing surface (DS) between the two corresponding regions, and it is exact only if it is free of recrossings. For time-independent barriers, the DS can be attached to the top of the corresponding saddle point of the potential energy surface, and in time-dependent systems, the DS is a moving object. The precise determination of these direct reaction rates, e.g., using transition state theory, requires the actual construction of a DS for a given saddle geometry, which is in general a demanding methodical and computational task, especially in high-dimensional systems. In this paper, we demonstrate how such time-dependent, global, and recrossing-free DSs can be constructed using neural networks. In our approach, the neural network uses the bath coordinates and time as input, and it is trained in a way that its output provides the position of the DS along the reaction coordinate. An advantage of this procedure is that, once the neural network is trained, the complete information about the dynamical phase space separation is stored in the network's parameters, and a precise distinction between reactants and products can be made for all possible system configurations, all times, and with little computational effort. We demonstrate this general method for two- and three-dimensional systems and explain its straightforward extension to even more degrees of freedom.

An unusual case of prolonged post-endoscopic retrograde cholangiopancreatography jaundice.

Science.gov (United States)

Tziatzios, Georgios; Gkolfakis, Paraskevas; Papanikolaou, Ioannis S; Dimitriadis, George; Triantafyllou, Konstantinos

2016-04-01

Despite the effectiveness of endoscopic retrograde cholangiopancreatography (ERCP) for the treatment of choledocholithiasis, various complications have been described. We herein report the first case of prolonged post-ERCP jaundice due to toxicity of the contrast agent Iobitridol (®XENETIX, Guerbet, Roissy CdG Cedex, France) in a patient who underwent ERCP with sphincterectomy and common bile duct stone removal. While clinical improvement and normalization of aminotransferases and cholestatic enzymes after the procedure, an unexplained increase of direct bilirubin was noticed. A second ERCP was performed one week later, excluding possible remaining choledocholithiasis. Nevertheless, serum direct bilirubin increased further up to 15 mg/dL. Other potential causes of direct hyperbilirubinemia were ruled out and patient's liver biopsy was compatible with drug-induced liver toxicity. Additionally, the cause-result time connection between the use of Iobitridol and bilirubin increase indicated the possibility of a toxic effect related to the repeated use of the particular contrast agent. Iobitridol, a contrast agent, can induce prolonged direct hyperbilirubinemia.

Evolution of perceived footwear comfort over a prolonged running session.

Science.gov (United States)

Hintzy, F; Cavagna, J; Horvais, N

2015-12-01

The purpose of this study was to investigate the subjective perception of overall footwear comfort over a prolonged running session. Ten runners performed two similar sessions consisting of a 13-km trail run (5 laps of 2.6 km) as fast as possible. The overall footwear comfort was evaluated before running and at the end of each lap with a 150-mm visual analogic scale, as well as speed, heart rate and rate of perceived exertion. The results showed that both overall footwear comfort and speed decreased consistently during the run session, and significantly after 44 min of running (i.e. the 3rd lap). It could be hypothesized that the deterioration of overall footwear comfort was explained by mechanical and energetical parameter changes with time and/or fatigue occurring at the whole body, foot and footwear levels. These results justify the use of a prolonged running test for running footwear comfort evaluation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mechanically activated SHS reaction in the Fe-Al system: in-situ time resolved diffraction using synchrotron radiation

International Nuclear Information System (INIS)

Gaffet, E.; Charlot, F.; Klein, D.; Bernard, F.; Niepce, J.C.

1998-01-01

The mechanical activation self propagating high temperature synthesis (M.A.S.H.S.) processing is a new way to produce nanocrystalline iron aluminide intermetallic compounds. This process is maily the combination of two steps; in the one hand, a mechanical activation where the Fe - Al powder mixture was milled during a short time at given energy and frequency of shocks and in the other hand, a self propagating high temperature synthesis (S.H.S.) reaction, for which the exothermicity of the Fe + Al reaction is used. This fast propagated MASHS reaction has been in-situ investigated using the time resolved X-ray diffraction (TRXRD) using a X-ray synchrotron beam and an infrared thermography camera, allowing the coupling of the materials structure and the temperature field. The effects of the initial mean compositions, of the milling conditions as well as of the compaction parameters on the MASHS reaction are reported. (orig.)

Designing driver assistance systems with crossmodal signals: multisensory integration rules for saccadic reaction times apply.

Directory of Open Access Journals (Sweden)

Rike Steenken

Full Text Available Modern driver assistance systems make increasing use of auditory and tactile signals in order to reduce the driver's visual information load. This entails potential crossmodal interaction effects that need to be taken into account in designing an optimal system. Here we show that saccadic reaction times to visual targets (cockpit or outside mirror, presented in a driving simulator environment and accompanied by auditory or tactile accessories, follow some well-known spatiotemporal rules of multisensory integration, usually found under confined laboratory conditions. Auditory nontargets speed up reaction time by about 80 ms. The effect tends to be maximal when the nontarget is presented 50 ms before the target and when target and nontarget are spatially coincident. The effect of a tactile nontarget (vibrating steering wheel was less pronounced and not spatially specific. It is shown that the average reaction times are well-described by the stochastic "time window of integration" model for multisensory integration developed by the authors. This two-stage model postulates that crossmodal interaction occurs only if the peripheral processes from the different sensory modalities terminate within a fixed temporal interval, and that the amount of crossmodal interaction manifests itself in an increase or decrease of second stage processing time. A qualitative test is consistent with the model prediction that the probability of interaction, but not the amount of crossmodal interaction, depends on target-nontarget onset asynchrony. A quantitative model fit yields estimates of individual participants' parameters, including the size of the time window. Some consequences for the design of driver assistance systems are discussed.

Reaction Time Variability in Children With ADHD Symptoms and/or Dyslexia

OpenAIRE

Gooch, Debbie; Snowling, Margaret J.; Hulme, Charles

2012-01-01

Reaction time (RT) variability on a Stop Signal task was examined among children with attention deficit hyperactivity disorder (ADHD) symptoms and/or dyslexia in comparison to typically developing (TD) controls. Children’s go-trial RTs were analyzed using a novel ex-Gaussian method. Children with ADHD symptoms had increased variability in the fast but not the slow portions of their RT distributions compared to those without ADHD symptoms. The RT distributions of children with d...

Implementation of Prolonged Exposure in the Army: Is Consultation Necessary for Effective Dissemination

Science.gov (United States)

2015-10-01

to hiring websites and local advertisements , and several candidates were identified. An initial part-time offer was made to Loreli Leos, LPC in July...2015). Prolonged exposure vs eye movement desensitization and reprocessing vs waiting list for posttraumatic stress disorder in patients with a

Effects of neuromuscular training on the reaction time and electromechanical delay of the peroneus longus muscle.

Science.gov (United States)

Linford, Christena W; Hopkins, J Ty; Schulthies, Shane S; Freland, Brent; Draper, David O; Hunter, Iain

2006-03-01

To examine the influence of a 6-week neuromuscular training program on the electromechanical delay and reaction time of the peroneus longus muscle. A 2 x 2 pre-post factorial design. Human performance research center biomechanics laboratory. Thirty-six healthy, physically active, college-age subjects were recruited for this study and 26 completed it. There were 5 men and 8 women in the treatment group (mean age +/- standard deviation, 21.9+/-2.1 y; height, 173.7+/-11.1cm; weight, 67.4+/-17.8 kg) and 6 men and 7 women in the control group (age, 21.8+/-2.3 y; height, 173.7+/-11.9 cm; weight, 70.8+/-19.4 kg). Subjects were not currently experiencing any lower-extremity pathology and had no history of injuries requiring treatment to either lower extremity. Subjects in the treatment group completed a 6-week neuromuscular training program involving various therapeutic exercises. Subjects in the control group were asked to continue their normal physical activity during the 6-week period. The electromechanical delay of the peroneus longus was determined by the onset of force contribution after artificial activation, as measured by electromyographic and forceplate data. Reaction time was measured after a perturbation during walking. Data were analyzed using two 2 x 2 analyses of covariance (covariate pretest score). Group (treatment, control) and sex (male, female) were between-subject factors. Neuromuscular training caused a decrease in reaction time to perturbation during walking compared with controls (F=4.030, P=.029), while there was a trend toward an increase in electromechanical delay (F=4.227, P=.052). There was no significant difference between sexes or the interaction of sex and treatment in either reaction time or electromechanical delay. The 6-week training program significantly reduced reaction time of the peroneus longus muscle in healthy subjects. Neuromuscular training may have a beneficial effect on improving dynamic restraint during activity.

Management of prolonged pregnancy

International Nuclear Information System (INIS)

Iqbal, S.

2004-01-01

Objective: To compare two strategies for management of prolonged pregnancy (= or >294 days) i.e. induction (intervention) versus expectant management (non-intervention) and evaluate the associated feto-maternal risks. Subjects and Methods: One hundred cases of uncomplicated prolonged gestation were selected. The gestational age was confirmed by ultrasound in first trimester. One group (50 patients) was managed by intervention i.e. induction of labour (group A) and other group (50 patients) by non-intervention i.e. expectant management (group B). In group A intervention was done at 42 weeks. In expectant group, the methods of monitoring were fetal kick charting recorded daily by the patient, and ultrasound for amniotic fluid index. The biophysical profile score and NST (non stress test) were performed once a week till 42 weeks and then twice weekly. Results: The frequency of prolonged pregnancy was found to be 10.9%. There was no significant difference in the number of spontaneous vaginal deliveries between the two groups. The rate of LSCS (lower segment caesarean section) was higher in intervention group ( 30% versus 18% ). The neonatal depression at birth was more in group B ( 10% versus 4%) and at 5 minutes almost same between two groups (4% versus 2%). There were 11 cases of meconium aspiration syndrome, leading to one neonatal death. Among nine perinatal deaths two were neonatal deaths. Seven cases of intrauterine deaths in which antepartum deaths occurred because of non compliance of patients. No cause could be detected for the other three fetuses. Conclusion: There was increased LSCS rate in group A. However in expectant group B perinatal mortality was about twice more as compared to intervention group. Active early intervention at 42 weeks is warranted to reduce perinatal morbidity and mortality. (author)

Prolonged labour associated with lower expression of syndecan 3 and connexin 43 in human uterine tissue

Directory of Open Access Journals (Sweden)

Malmström Anders

2006-05-01

Full Text Available Abstract Background Prolonged labour is associated with greater morbidity and mortality for mother and child. Connexin 43 is a major myometrial gap junction protein found in human myometrium. Syndecan 3 seems to prevail in the human uterus among heparan sulphate proteoglycans, showing the most significant increase during labour. The aims of the present study were to investigate syndecan 3 and connexin 43 mRNA expressions and protein distributions in human uterine tissue during normal and prolonged labour. Methods Uterine isthmic biopsies were collected from non-pregnant (n = 7, term pregnant women not in labour (n = 14, in normal labour (n = 7 and in prolonged labour (n = 7. mRNA levels of syndecan 3 and connexin 43 were determined by real time RT-PCR. The localization and expression were demonstrated by immunohistochemistry and confocal microscopy. Results In women with prolonged labour, the mRNA expressions of syndecan 3 and Connexin 43 were considerably lower than the expression level at normal labour (p Conclusion The high expression of syndecan 3 and connexin 43 and their co-localization to the smooth muscle bundles during normal labour, together with the significant reduction in prolonged labour, may indicate a role for these proteins in the co-ordination of myometrial contractility.

Time-resolved resonance fluorescence spectroscopy for study of chemical reactions in laser-induced plasmas.

Science.gov (United States)

Liu, Lei; Deng, Leimin; Fan, Lisha; Huang, Xi; Lu, Yao; Shen, Xiaokang; Jiang, Lan; Silvain, Jean-François; Lu, Yongfeng

2017-10-30

Identification of chemical intermediates and study of chemical reaction pathways and mechanisms in laser-induced plasmas are important for laser-ablated applications. Laser-induced breakdown spectroscopy (LIBS), as a promising spectroscopic technique, is efficient for elemental analyses but can only provide limited information about chemical products in laser-induced plasmas. In this work, time-resolved resonance fluorescence spectroscopy was studied as a promising tool for the study of chemical reactions in laser-induced plasmas. Resonance fluorescence excitation of diatomic aluminum monoxide (AlO) and triatomic dialuminum monoxide (Al 2 O) was used to identify these chemical intermediates. Time-resolved fluorescence spectra of AlO and Al 2 O were used to observe the temporal evolution in laser-induced Al plasmas and to study their formation in the Al-O 2 chemistry in air.

Time variation in the reaction-zone structure of two-phase spray detonations.

Science.gov (United States)

Pierce, T. H.; Nicholls, J. A.

1973-01-01

A detailed theoretical analysis of the time-varying detonation structure in a monodisperse spray is presented. The theory identifies experimentally observed reaction-zone overpressures as deriving from blast waves formed therein by the explosive ignition of the spray droplets, and follows in time the motion, change in strength, and interactions of these blast waves with one another, and with the leading shock. The results are compared with experimental data by modeling the motion of a finite-size circular pressure transducer through the theoretical data field in an x-t space.

Analysis of Choice Stepping with Visual Interference Can Detect Prolonged Postural Preparation in Older Adults with Mild Cognitive Impairment at High Risk of Falling.

Science.gov (United States)

Uemura, Kazuki; Hasegawa, Takashi; Tougou, Hiroki; Shuhei, Takahashi; Uchiyama, Yasushi

2015-01-01

We aimed to clarify postural control deficits in older adults with mild cognitive impairment (MCI) at high risk of falling by addressing the inhibitory process. This study involved 376 community-dwelling older adults with MCI. Participants were instructed to execute forward stepping on the side indicated by the central arrow while ignoring the 2 flanking arrows on each side (→→→→→, congruent, or →→←→→, incongruent). Initial weight transfer direction errors [anticipatory postural adjustment (APA) errors], step execution times, and divided phases (reaction, APA, and swing phases) were measured from vertical force data. Participants were categorized as fallers (n = 37) and non-fallers (n = 339) based on fall experiences in the last 12 months. There were no differences in the step execution times, swing phases, step error rates, and APA error rates between groups, but fallers had a significantly longer APA phase relative to non-fallers in trials of the incongruent condition with APA errors (p = 0.005). Fallers also had a longer reaction phase in trials with the correct APA, regardless of the condition (p = 0.01). Analyses of choice stepping with visual interference can detect prolonged postural preparation as a specific falling-associated deficit in older adults with MCI. © 2015 S. Karger AG, Basel.

A Study of Correlations among Image Resolution, Reaction Time, and Extent of Motion in Remote Motor Interactions

Directory of Open Access Journals (Sweden)

Zoltán Rusák

2014-01-01

Full Text Available Motor interaction in virtual sculpting, dance trainings, and physiological rehabilitation requires close virtual proximity of users, which may be hindered by low resolution of images and system latency. This paper reports on the results of our investigation aiming to explore the pros and cons of using ultrahigh 4K resolution displays (4096 × 2160 pixels in remote motor interaction. 4K displays are able to overcome the problem of visible pixels and they are able to show more accurate image details on the level of textures, shadows, and reflections. It was our assumption that such image details can not only satisfy visual comfort of the users, but also provide detailed visual cues and improve the reaction time of users in motor interaction. To validate this hypothesis, we explored the relationships between the reaction time of subjects responding to a series of action-reaction type of games and resolution of the image used in an experiment. The results of our experiment showed that the subjects’ reaction time is significantly shorter in 4K images than in HD or VGA images in motor interaction with small motion envelope.

Muscle Reaction Time During a Simulated Lateral Ankle Sprain After Wet-Ice Application or Cold-Water Immersion.

Science.gov (United States)

Thain, Peter K; Bleakley, Christopher M; Mitchell, Andrew C S

2015-07-01

Cryotherapy is used widely in sport and exercise medicine to manage acute injuries and facilitate rehabilitation. The analgesic effects of cryotherapy are well established; however, a potential caveat is that cooling tissue negatively affects neuromuscular control through delayed muscle reaction time. This topic is important to investigate because athletes often return to exercise, rehabilitation, or competitive activity immediately or shortly after cryotherapy. To compare the effects of wet-ice application, cold-water immersion, and an untreated control condition on peroneus longus and tibialis anterior muscle reaction time during a simulated lateral ankle sprain. Randomized controlled clinical trial. University of Hertfordshire human performance laboratory. A total of 54 physically active individuals (age = 20.1 ± 1.5 years, height = 1.7 ± 0.07 m, mass = 66.7 ± 5.4 kg) who had no injury or history of ankle sprain. Wet-ice application, cold-water immersion, or an untreated control condition applied to the ankle for 10 minutes. Muscle reaction time and muscle amplitude of the peroneus longus and tibialis anterior in response to a simulated lateral ankle sprain were calculated. The ankle-sprain simulation incorporated a combined inversion and plantar-flexion movement. We observed no change in muscle reaction time or muscle amplitude after cryotherapy for either the peroneus longus or tibialis anterior (P > .05). Ten minutes of joint cooling did not adversely affect muscle reaction time or muscle amplitude in response to a simulated lateral ankle sprain. These findings suggested that athletes can safely return to sporting activity immediately after icing. Further evidence showed that ice can be applied before ankle rehabilitation without adversely affecting dynamic neuromuscular control. Investigation in patients with acute ankle sprains is warranted to assess the clinical applicability of these interventions.

Reduced linear noise approximation for biochemical reaction networks with time-scale separation: The stochastic tQSSA+

Science.gov (United States)

Herath, Narmada; Del Vecchio, Domitilla

2018-03-01

Biochemical reaction networks often involve reactions that take place on different time scales, giving rise to "slow" and "fast" system variables. This property is widely used in the analysis of systems to obtain dynamical models with reduced dimensions. In this paper, we consider stochastic dynamics of biochemical reaction networks modeled using the Linear Noise Approximation (LNA). Under time-scale separation conditions, we obtain a reduced-order LNA that approximates both the slow and fast variables in the system. We mathematically prove that the first and second moments of this reduced-order model converge to those of the full system as the time-scale separation becomes large. These mathematical results, in particular, provide a rigorous justification to the accuracy of LNA models derived using the stochastic total quasi-steady state approximation (tQSSA). Since, in contrast to the stochastic tQSSA, our reduced-order model also provides approximations for the fast variable stochastic properties, we term our method the "stochastic tQSSA+". Finally, we demonstrate the application of our approach on two biochemical network motifs found in gene-regulatory and signal transduction networks.

Successful desensitization protocol for hypersensitivity reaction probably caused by dabrafenib in a patient with metastatic melanoma.

Science.gov (United States)

Bar-Sela, Gil; Abu-Amna, Mahmoud; Hadad, Salim; Haim, Nissim; Shahar, Eduardo

2015-09-01

Vemurafenib and dabrafenib are both orally bioavailable small molecule agents that block mitogen activated protein kinase signalling in patients with melanoma and BRAF(V600E) mutation. Generalized hypersensitivity reactions to vemurafenib or dabrafenib have not been described. Continuing vemurafenib or dabrafenib therapy despite hypersensitivity reaction is especially important in patients with melanoma and BRAF(V600E) mutation, in whom this mutation plays a critical role in tumour growth. Desensitization protocols to overcome hypersensitivity reactions by gradual reintroduction of small amounts of the offending drug up to full therapeutic doses are available for many anti-cancer agents, including vemurafenib but, to the best of our knowledge, have not been reported for dabrafenib. We describe a patient with metastatic melanoma who developed Type I hypersensitivity reaction to vemurafenib and to subsequent treatment with dabrafenib, and who was successfully treated by drug desensitization which allowed safe prolonged continuation of dabrafenib. The development of hypersensitivity reactions for both dabrafenib and vemurafinib in the current case could be because these drugs have a similar chemical structure and cause a cross-reactivity. However, hypersensitivity reaction to a non-medicinal ingredient shared by the two drugs is also possible. Oral desensitization appears to be an option for patients with hypersensitivity Type I to dabrafenib. This approach may permit clinicians to safely administer dabrafenib to patients who experience hypersensitivity reactions to this life-prolonging medication. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Prolonged job strain and subsequent risk of cancer in women–a longitudinal study, based on the Danish Nurse Cohort

DEFF Research Database (Denmark)

Vesterlund, Gitte K.; Høeg, Beverley L.; Johansen, Christoffer

2017-01-01

Background: The role of psychological stress in cancer risk is continuously debated. Stress at work is the most common form of stress and previous studies have shown inconsistent results regarding cancer risk. In this longitudinal study, we examined the association between prolonged job strain......-related, digestive and lung cancers according to level of prolonged job strain. The women were followed from 1 January 2000 until cancer diagnosis, emigration, death or 31 December 2013 (mean follow-up 13 years) and models were adjusted for potential confounders. Effect modification was examined according to working...... nightshifts and full time. Results: No significant differences in the risk of overall cancer or any of the cancer subgroups were identified in relation to prolonged busyness, speed, influence, or overall job strain. Effect modification by working full time was observed when examining job influence in relation...

Development of prolonged standing strain index to quantify risk levels of standing jobs.

Science.gov (United States)

Halim, Isa; Omar, Abdul Rahman

2012-01-01

Many occupations in industry such as metal stamping workers, electronics parts assembly operators, automotive industry welders, and lathe operators require working in a standing posture for a long time. Prolonged standing can contribute to discomfort and muscle fatigue particularly in the back and legs. This study developed the prolonged standing strain index (PSSI) to quantify the risk levels caused by standing jobs, and proposed recommendations to minimize the risk levels. Risk factors associated with standing jobs, such as working posture, muscles activity, standing duration, holding time, whole-body vibration, and indoor air quality, were the basis for developing the PSSI. All risk factors were assigned multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness. multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness.

Use of a microwave cavity to reduce reaction times in radiolabelling with [11C]cyanide

International Nuclear Information System (INIS)

Thorell, J.-O.; Stone-Elander, S.; Elander, N.

1992-01-01

Advantages of using a microwave cavity over thermal treatment are demonstrated for radiolabelling reactions with [ 11 C]cyanide. For comparison purposes, two literature syntheses involving typical cyanide chemistry at rather vigorous conditions were investigated: cyano-de-halogenation with subsequent hydrolysis of the nitrile and the Bucher-Strecker synthesis of an aromatic amino acid. Comparable yields were obtained with intensities <100 W in reaction times that were 1/15 to 1/20th those used in thermal methods. Even rates of slower nucleophilic substitutions could be increased by manipulating the polarity of the medium. For the short-lived radionuclide carbon-11, such time gains result in radioactivity gains at the end-of-synthesis on the order of 70-100%. (Author)

Monitoring Acidophilic Microbes with Real-Time Polymerase Chain Reaction (PCR) Assays

Energy Technology Data Exchange (ETDEWEB)

Frank F. Roberto

2008-08-01

Many techniques that are used to characterize and monitor microbial populations associated with sulfide mineral bioleaching require the cultivation of the organisms on solid or liquid media. Chemolithotrophic species, such as Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans, or thermophilic chemolithotrophs, such as Acidianus brierleyi and Sulfolobus solfataricus can grow quite slowly, requiring weeks to complete efforts to identify and quantify these microbes associated with bioleach samples. Real-time PCR (polymerase chain reaction) assays in which DNA targets are amplified in the presence of fluorescent oligonucleotide primers, allowing the monitoring and quantification of the amplification reactions as they progress, provide a means of rapidly detecting the presence of microbial species of interest, and their relative abundance in a sample. This presentation will describe the design and use of such assays to monitor acidophilic microbes in the environment and in bioleaching operations. These assays provide results within 2-3 hours, and can detect less than 100 individual microbial cells.

[REAL TIME POLYMERASE CHAIN REACTION IN TULAREMIA LABORATORY DIAGNOSTICS].

Science.gov (United States)

Kormilitsyna, M I; Mescheryakova, I S; Mikhailova, T V; Dobrovolsky, A A

2015-01-01

Enhancement of tularemia laboratory diagnostics by F. tularensis DNA determination in blood sera of patients using real time polymerase chain reaction (RT-PCR). 39 blood sera of patients obtained during transmissive epidemic outbreak of tularemia in Khanty-Mansiysk in 2013 were studied in agglutination reaction, passive hemagglutination, RT-PCR. Specific primers and fluorescent probes were used: ISFTu2F/R+ISFTu2P, Tu14GF/R+tul4-PR2. Advantages of using RT-PCR for early diagnostics of tularemia, when specific antibodies are not detected using traditional immunologic methods, were established. Use of a combination of primers and ISFTu2F/R+ISFTu2P probe allowed to detect F. tularensis DNA in 100% of sera, whereas Tul4G F/R+tul4-PR2 combination--92% of sera. The data were obtained when DNA was isolated from sera using "Proba Rapid" express method. Clinical-epidemiologic diagnosis oftularemia was confirmed by both immune-serologic and RT-PCR methods when sera were studied 3-4 weeks after the onset of the disease. RT-PCR with ISFTu2F/R primers and fluorescent probe ISFTu2P, having high sensitivity and specificity, allows to determine F. tularensis DNA in blood sera of patients at both the early stage and 3-4 weeks after the onset of the disease.

Emerging Object Representations in the Visual System Predict Reaction Times for Categorization

Science.gov (United States)

Ritchie, J. Brendan; Tovar, David A.; Carlson, Thomas A.

2015-01-01

Recognizing an object takes just a fraction of a second, less than the blink of an eye. Applying multivariate pattern analysis, or “brain decoding”, methods to magnetoencephalography (MEG) data has allowed researchers to characterize, in high temporal resolution, the emerging representation of object categories that underlie our capacity for rapid recognition. Shortly after stimulus onset, object exemplars cluster by category in a high-dimensional activation space in the brain. In this emerging activation space, the decodability of exemplar category varies over time, reflecting the brain’s transformation of visual inputs into coherent category representations. How do these emerging representations relate to categorization behavior? Recently it has been proposed that the distance of an exemplar representation from a categorical boundary in an activation space is critical for perceptual decision-making, and that reaction times should therefore correlate with distance from the boundary. The predictions of this distance hypothesis have been born out in human inferior temporal cortex (IT), an area of the brain crucial for the representation of object categories. When viewed in the context of a time varying neural signal, the optimal time to “read out” category information is when category representations in the brain are most decodable. Here, we show that the distance from a decision boundary through activation space, as measured using MEG decoding methods, correlates with reaction times for visual categorization during the period of peak decodability. Our results suggest that the brain begins to read out information about exemplar category at the optimal time for use in choice behaviour, and support the hypothesis that the structure of the representation for objects in the visual system is partially constitutive of the decision process in recognition. PMID:26107634

Crystal phase evolution of TiO2 nanoparticles with reaction time in acidic solutions studied via freeze-drying method

International Nuclear Information System (INIS)

Shin, Hyunho; Jung, Hyun Suk; Hong, Kug Sun; Lee, Jung-Kun

2005-01-01

The crystal phase evolution of TiO 2 nanoparticles, during hydrolysis and condensation of titanium tetraisopropoxide, was quenched at various reaction times by a freeze-drying method, followed by various characterizations. Three types of solutions with different acid input times were studied: (1) addition in infinite time (no addition) (2) addition at 24h after the hydrolysis/condensation reaction started, and (3) addition from the beginning of the reaction. The acid-free solution yielded amorphous TiO 2 , which transformed to anatase very slowly. The acid input in 24h resulted in a fast transformation of amorphous to a metastable anatase having a highly distorted atomic arrangement: thereby its transformation to a more stable phase, rutile, was suitable. The acid addition from the beginning of the reaction yielded the formation of a relatively stable anatase from the hydrolysis seed, thereby the subsequent transformation to rutile was sluggish

Relationships between Static and Dynamic Balance and Anticipation Time, Reaction Time in School Children at the Age of 10-12 Years

Science.gov (United States)

Bozkurt, Sinan; Erkut, Oya; Akkoç, Orkun

2017-01-01

The aim of this study is to investigate the relationship between anticipation time, reaction time and balance characteristics in school children at the age of 10-12 years. 11 males and 12 females, 23 students in total, studying at Istanbul Sancaktepe Ibn-i Sina Elementary School, whose average age was 11.06 years, average height was 142.78 cm and…

Phenol hydroxylation on Al-Fe modified-bentonite: Effect of Fe loading, temperature and reaction time

Science.gov (United States)

Widi, R. K.; Budhyantoro, A.; Christianto, A.

2017-11-01

The present work reflects the study of the phenol hydroxylation reactions to synthesize hydroquinone and catechol on Al-Fe modified-bentonite. This study started with synthesizes the catalyst material based on the modified bentonite. Natural bentonite from Pacitan, Indonesia was intercalated with Cetyl-TetramethylammoniumBromida (CTMA-Br) followed by pillarization using Alumina. The pillared bentonite was then impregnated with Fe solution (0.01 M, 0.05 M, and 0.1 M). The solid material obtained was calcined at 723 K for 4 hours. All the materials were characterized using BET N2 adsorption. Their catalytic activity and selectivity were studied for phenol hydroxylation using H2O2 (30%). The reaction conditions of this reaction were as follows: ratio of phenol/H2O2 = 1:1 (molar ratio), concentration of phenol = 1 M and ratio of catalyst/phenol was 1:10. Reaction temperatures were varied at 333, 343 and 353 K. The reaction time was also varied at 3, 4 and 5 hours. The result shows that the materials have potential catalyst activity.

Effects on the development of Dipylidium caninum and on the host reaction to this parasite in the adult flea (Ctenocephalides felis felis).

Science.gov (United States)

Pugh, R E

1987-01-01

Temperature was found to be a major factor affecting the development of Dipylidium caninum and the presence of a host reaction of adult Ctenocephalides felis felis to D. caninum. Adult fleas reared at 30-32 degrees C contained fully developed metacestodes when they emerged from their cocoons. However at lower temperatures, D. caninum could not complete development until the flea hosts had spent some time on their mammalian hosts. It was the surface temperature of the mammals (31-36 degrees C) and not the fleas' blood meals which resulted in the metacestodes completing their development. This development of D. caninum was therefore independent of the flea development. At 20 degrees C, a larger and more prolonged host reaction was mounted than at higher temperatures. The larval flea diet had a small effect on the subsequent cestode development and the adult fleas' reaction to it.

Cold Ischemia Time is an Important Risk Factor for Post-Liver Transplant Prolonged Length of Stay.

Science.gov (United States)

Pan, Evelyn T; Yoeli, Dor; Galvan, N Thao N; Kueht, Michael L; Cotton, Ronald T; O'Mahony, Christine A; Goss, John A; Rana, Abbas

2018-02-24

Risk analysis of cold ischemia time (CIT) in liver transplantation has largely focused on patient and graft survival. Post-transplant length of stay is a sensitive marker of morbidity and cost. We hypothesize that CIT is a risk factor for post-transplant prolonged length of stay (PLOS) and aim to conduct an hour-by-hour analysis of CIT and PLOS. We retrospectively reviewed all adult, first-time liver transplants between March 2002 and September 2016 in the United Network for Organ Sharing database. 67,426 recipients were categorized by hourly CIT increments. Multivariable logistic regression of PLOS (defined as > 30 days), CIT groups, and an extensive list of confounding variables was performed. Linear regression between length of stay and CIT as continuous variables was also performed. CIT 1-6 hours was protective against PLOS, while CIT greater than 7 hours was associated with increased odds for PLOS. The lowest odds for PLOS were observed with 1-2 (odds ratio (OR) = 0.65, 95% confidence interval (CI) 0.45-0.92) and 2-3 hours (OR = 0.65, 95% CI 0.55-0.78) of CIT. OR for PLOS steadily increased with increasing CIT, reaching the greatest odds for PLOS with 13-14 hours (OR = 2.05, 95% CI 1.57-2.67) and 15-16 hours (OR = 2.06, 95% CI 1.27-3.33) of CIT. Linear regression revealed a positive correlation between length of stay and cold ischemia time with a correlation coefficient of +0.35 (p < 0.001). Post-liver transplant length of stay is sensitive to CIT, with substantial increase in the odds of PLOS observed with nearly every additional hour of cold ischemia. We conclude that CIT should be minimized to protect against the morbidity and cost associated with post-transplant PLOS. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

Directional errors of movements and their correction in a discrete tracking task. [pilot reaction time and sensorimotor performance

Science.gov (United States)

Jaeger, R. J.; Agarwal, G. C.; Gottlieb, G. L.

1978-01-01

Subjects can correct their own errors of movement more quickly than they can react to external stimuli by using three general categories of feedback: (1) knowledge of results, primarily visually mediated; (2) proprioceptive or kinaesthetic such as from muscle spindles and joint receptors, and (3) corollary discharge or efference copy within the central nervous system. The effects of these feedbacks on simple reaction time, choice reaction time, and error correction time were studied in four normal human subjects. The movement used was plantarflexion and dorsiflexion of the ankle joint. The feedback loops were modified, by changing the sign of the visual display to alter the subject's perception of results, and by applying vibration at 100 Hz simultaneously to both the agonist and antagonist muscles of the ankle joint. The central processing was interfered with when the subjects were given moderate doses of alcohol (blood alcohol concentration levels of up to 0.07%). Vibration and alcohol increase both the simple and choice reaction times but not the error correction time.

The mineralogic evolution of the Martian surface through time: Implications from chemical reaction path modeling studies

Science.gov (United States)

Plumlee, G. S.; Ridley, W. I.; Debraal, J. D.; Reed, M. H.

1993-01-01

Chemical reaction path calculations were used to model the minerals that might have formed at or near the Martian surface as a result of volcano or meteorite impact driven hydrothermal systems; weathering at the Martian surface during an early warm, wet climate; and near-zero or sub-zero C brine-regolith reactions in the current cold climate. Although the chemical reaction path calculations carried out do not define the exact mineralogical evolution of the Martian surface over time, they do place valuable geochemical constraints on the types of minerals that formed from an aqueous phase under various surficial and geochemically complex conditions.

The impact of prolonged violent video-gaming on adolescent sleep: an experimental study.

Science.gov (United States)

King, Daniel L; Gradisar, Michael; Drummond, Aaron; Lovato, Nicole; Wessel, Jason; Micic, Gorica; Douglas, Paul; Delfabbro, Paul

2013-04-01

Video-gaming is an increasingly prevalent activity among children and adolescents that is known to influence several areas of emotional, cognitive and behavioural functioning. Currently there is insufficient experimental evidence about how extended video-game play may affect adolescents' sleep. The aim of this study was to investigate the short-term impact of adolescents' prolonged exposure to violent video-gaming on sleep. Seventeen male adolescents (mean age = 16 ± 1 years) with no current sleep difficulties played a novel, fast-paced, violent video-game (50 or 150 min) before their usual bedtime on two different testing nights in a sleep laboratory. Objective (polysomnography-measured sleep and heart rate) and subjective (single-night sleep diary) measures were obtained to assess the arousing effects of prolonged gaming. Compared with regular gaming, prolonged gaming produced decreases in objective sleep efficiency (by 7 ± 2%, falling below 85%) and total sleep time (by 27 ± 12 min) that was contributed by a near-moderate reduction in rapid eye movement sleep (Cohen's d = 0.48). Subjective sleep-onset latency significantly increased by 17 ± 8 min, and there was a moderate reduction in self-reported sleep quality after prolonged gaming (Cohen's d = 0.53). Heart rate did not differ significantly between video-gaming conditions during pre-sleep game-play or the sleep-onset phase. Results provide evidence that prolonged video-gaming may cause clinically significant disruption to adolescent sleep, even when sleep after video-gaming is initiated at normal bedtime. However, physiological arousal may not necessarily be the mechanism by which technology use affects sleep. © 2012 European Sleep Research Society.

Prolonged displacement may compromise resilience in Eritrean mothers.

Science.gov (United States)

Almedom, Astier; Tesfamichael, Berhe; Mohammed, Zein; Mascie-Taylor, Nick; Muller, Jocelyn; Alemu, Zemui

2005-12-01

to assess the impact of prolonged displacement on the resilience of Eritrean mothers. an adapted SOC scale (short form) was administered. Complementary qualitative data were gathered from study participants' spontaneous reactions to and commentaries on the SOC scale. Displaced women's SOC scores were significantly less than those of the non-displaced: Mean = 54.84; SD = 6.48 in internally displaced person (IDP) camps, compared to non-displaced urban and rural/pastoralist: Mean = 48. 94, SD = 11.99; t = 3.831, p urban (non-displaced). Rural but traditionally mobile (pastoralist or transhumant) communities scored more or less the same as the urban non-displaced--i.e., significantly higher than those in IDP camps (p urban and pastoralist/transhumant groups were similar, while women in IDP camps were lower scoring--RR = .268, p < .001. The implications of these findings for health policy are critical. It is incumbent on the international health institutions including the World Health Organization and regional as well as local players to address the plight of internally displaced women, their families and communities in Eritrea and other places of dire conditions such as, for example Darfur in the Sudan.

Reaction time, impulsivity, and attention in hyperactive children and controls: a video game technique.

Science.gov (United States)

Mitchell, W G; Chavez, J M; Baker, S A; Guzman, B L; Azen, S P

1990-07-01

Maturation of sustained attention was studied in a group of 52 hyperactive elementary school children and 152 controls using a microcomputer-based test formatted to resemble a video game. In nonhyperactive children, both simple and complex reaction time decreased with age, as did variability of response time. Omission errors were extremely infrequent on simple reaction time and decreased with age on the more complex tasks. Commission errors had an inconsistent relationship with age. Hyperactive children were slower, more variable, and made more errors on all segments of the game than did controls. Both motor speed and calculated mental speed were slower in hyperactive children, with greater discrepancy for responses directed to the nondominant hand, suggesting that a selective right hemisphere deficit may be present in hyperactives. A summary score (number of individual game scores above the 95th percentile) of 4 or more detected 60% of hyperactive subjects with a false positive rate of 5%. Agreement with the Matching Familiar Figures Test was 75% in the hyperactive group.

Time scale in quasifission reactions

Energy Technology Data Exchange (ETDEWEB)

Back, B.B.; Paul, P.; Nestler, J. [and others

1995-08-01

The quasifission process arises from the hindrance of the complete fusion process when heavy-ion beams are used. The strong dissipation in the system tends to prevent fusion and lead the system towards reseparation into two final products of similar mass reminiscent of a fission process. This dissipation slows down the mass transfer and shape transformation and allows for the emission of high energy {gamma}-rays during the process, albeit with a low probability. Giant Dipole {gamma} rays emitted during this time have a characteristic spectral shape and may thus be discerned in the presence of a background of {gamma} rays emitted from the final fission-like fragments. Since the rate of GDR {gamma} emission is very well established, the strength of this component may therefore be used to measure the timescale of the quasifission process. In this experiment we studied the reaction between 368-MeV {sup 58}Ni and a {sup 165}Ho target, where deep inelastic scattering and quasifission processes are dominant. Coincidences between fission fragments (detected in four position-sensitive avalanche detectors) and high energy {gamma} rays (measured in a 10{close_quotes} x 10{close_quotes} actively shielded NaI detector) were registered. Beams were provided by the Stony Brook Superconducting Linac. The {gamma}-ray spectrum associated with deep inelastic scattering events is well reproduced by statistical cooling of projectile and target-like fragments with close to equal initial excitation energy sharing. The y spectrum associated with quasifission events is well described by statistical emission from the fission fragments alone, with only weak evidence for GDR emission from the mono-nucleus. A 1{sigma} limit of t{sub ss} < 11 x 10{sup -21} s is obtained for the mono-nucleus lifetime, which is consistent with the lifetime obtained from quasifission fragment angular distributions. A manuscript was accepted for publication.

Characterizing prolonged heat effects on mortality in a sub-tropical high-density city, Hong Kong

Science.gov (United States)

Ho, Hung Chak; Lau, Kevin Ka-Lun; Ren, Chao; Ng, Edward

2017-11-01

Extreme hot weather events are likely to increase under future climate change, and it is exacerbated in urban areas due to the complex urban settings. It causes excess mortality due to prolonged exposure to such extreme heat. However, there is lack of universal definition of prolonged heat or heat wave, which leads to inadequacies of associated risk preparedness. Previous studies focused on estimating temperature-mortality relationship based on temperature thresholds for assessing heat-related health risks but only several studies investigated the association between types of prolonged heat and excess mortality. However, most studies focused on one or a few isolated heat waves, which cannot demonstrate typical scenarios that population has experienced. In addition, there are limited studies on the difference between daytime and nighttime temperature, resulting in insufficiency to conclude the effect of prolonged heat. In sub-tropical high-density cities where prolonged heat is common in summer, it is important to obtain a comprehensive understanding of prolonged heat for a complete assessment of heat-related health risks. In this study, six types of prolonged heat were examined by using a time-stratified analysis. We found that more consecutive hot nights contribute to higher mortality risk while the number of consecutive hot days does not have significant association with excess mortality. For a day after five consecutive hot nights, there were 7.99% [7.64%, 8.35%], 7.74% [6.93%, 8.55%], and 8.14% [7.38%, 8.88%] increases in all-cause, cardiovascular, and respiratory mortality, respectively. Non-consecutive hot days or nights are also found to contribute to short-term mortality risk. For a 7-day-period with at least five non-consecutive hot days and nights, there was 15.61% [14.52%, 16.70%] increase in all-cause mortality at lag 0-1, but only -2.00% [-2.83%, -1.17%] at lag 2-3. Differences in the temperature-mortality relationship caused by hot days and hot nights

Effect of prolonged mixing time on concrete properties

International Nuclear Information System (INIS)

Mohd Noorul Ikhsan Mohamed; Sidek, H.A.A.; Wahab, Z.A.

2009-01-01

The correlation between workability, compressive strength and mixing time of fresh concrete has been studied. The concrete samples used in the study are normal concrete of grade 30. The mix design of the concrete samples was estimated using software called Calcrete. Three concrete cubes of 150 mm size were cast immediately after mixing. The same grade of concrete was prepared with the mixing time of 30 minutes to 5 hours. All of the concrete samples were cured for 28 days under room temperature before they were compressed using a compression machine. Result shows that the compressive strength of concrete decreases when mixing time is increased. (author)

Development of Capillary Loop Convective Polymerase Chain Reaction Platform with Real-Time Fluorescence Detection

Directory of Open Access Journals (Sweden)

Wen-Pin Chou

2017-02-01

Full Text Available Polymerase chain reaction (PCR has been one of the principal techniques of molecular biology and diagnosis for decades. Conventional PCR platforms, which work by rapidly heating and cooling the whole vessel, need complicated hardware designs, and cause energy waste and high cost. On the other hand, partial heating on the various locations of vessels to induce convective solution flows by buoyancy have been used for DNA amplification in recent years. In this research, we develop a new convective PCR platform, capillary loop convective polymerase chain reaction (clcPCR, which can generate one direction flow and make the PCR reaction more stable. The U-shaped loop capillaries with 1.6 mm inner diameter are designed as PCR reagent containers. The clcPCR platform utilizes one isothermal heater for heating the bottom of the loop capillary and a CCD device for detecting real-time amplifying fluorescence signals. The stable flow was generated in the U-shaped container and the amplification process could be finished in 25 min. Our experiments with different initial concentrations of DNA templates demonstrate that clcPCR can be applied for precise quantification. Multiple sample testing and real-time quantification will be achieved in future studies.

Psychotropic Pharmacotherapy Associated With QT Prolongation Among Veterans With Posttraumatic Stress Disorder.

Science.gov (United States)

Stock, Eileen M; Zeber, John E; McNeal, Catherine J; Banchs, Javier E; Copeland, Laurel A

2018-04-01

In 2012, the Food and Drug Administration issued Drug Safety Communications on several drugs associated with QT prolongation and fatal ventricular arrhythmias. Among these was citalopram, a selective serotonin reuptake inhibitor (SSRI) approved for depression and commonly used for posttraumatic stress disorder (PTSD). Evaluation of the risk for QT prolongation among other psychotropic drugs for individuals with PTSD remains limited. Explore psychotropic drugs associated with QT prolongation among veterans with PTSD. Patients in the Veterans Health Administration in 2006-2009 with PTSD and QT prolongation (176 cases) were matched 1:4 on age, gender, visit date and setting, and physical comorbidity. Classification trees assessed QT prolongation risk among prescribed medications (n=880). Receipt of any drug with known risk of QT prolongation varied by group (23% QT cases vs 15% control, prisks included ziprasidone (3% vs 1%, p=0.02) and buspirone (6% vs 2%, p=0.01). Increased risk was not observed for the SSRIs, citalopram and fluoxetine. Classification trees found that sotalol and amitriptyline carried greater risk among cardiac patients and methadone, especially if prescribed with quetiapine, among noncardiac patients. Per adjusted survival model, patients with QT prolongation were at increased risk for death (hazard ratio=1.60; 95% CI=1.04-2.44). Decision models are particularly advantageous when exploring nonlinear relationships or nonadditive interactions. These findings may potentially affect clinical decision-making concerning treatment for PTSD. For patients at higher risk of QT prolongation, antidepressants other than amitriptyline should be considered. Medications for comorbid conditions should also be closely monitored for heightened QT prolongation risk.

On the time behaviour of the concentration of pyrazinium radical cations in the early stage of the Maillard reaction

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Stoesser, Reinhard; Klein, Jeannette; Peschke, Simone; Zehl, Andrea; Cämmerer, Bettina; Kroh, Lothar W.

2007-08-01

During the early stage of the Maillard reaction pyrazinium radical cations were detected by ESR within the reaction system D-glucose/glycine. The spectra were characterized by completely resolved hyperfine structure. The partial pressure of oxygen and the radical concentrations were measured directly in the reaction mixture by ESR using solutions of the spin probe TEMPOL and of DPPH, respectively. There are quantitative and qualitative relations of the actual concentration of the radical ions to the partial pressure of oxygen, the temperature-time regime and the mechanical mixing of the reaction system. These macroscopic parameters significantly affect both the induction period and the velocity of the time-dependent formation of free radicals. From in situ variations of p(O 2) and p(Ar) including the connected mixing effects caused by the passing the gases through the reaction mixture, steric and chemical effects of the stabilization of the radical ions were established. The determination of suitable and relevant conditions for stabilization and subsequent radical reactions contributes to the elucidation of the macroscopically known antioxidant activity of Maillard products.

Cerebral activation related to implicit sequence learning in a Double Serial Reaction Time task

NARCIS (Netherlands)

van der Graaf, FHCE; Maguire, RP; Leenders, KL; de Jong, BM

2006-01-01

Using functional magnetic resonance imaging (fMRI), we examined the distribution of cerebral activations related to implicitly learning a series of fixed stimulus-response combinations. In a novel - bimanual - variant of the Serial Reaction Time task (SRT), simultaneous finger movements of the two

QT Prolongation Complicated with Torsades de Pointes in Prosthetic Mitral Valve Endocarditis: A Case Report

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A. Tounsi

2012-01-01

Full Text Available We present the case of a 49-year-old male patient with prosthetic mitral valve endocarditis associated with QT prolongation and torsades de pointes. He was asymptomatic until the end of January 2012, when he was admitted to our hospital emergency unit because of syncope, fever, and suspicion of endocarditis. Cardiologic evaluation was requested and the transthoracic (TTE and transesophageal (TEE echocardiograms revealed vegetations on the prosthetic mitral valve. All cultures were positive for methicillin-sensitive Staphylococcus aureus. The corrected QT (QTc interval was markedly prolonged upon admission (QTc 540 ms. He experienced torsades de pointes (TdP several times and he was recovered after bystander cardiopulmonary resuscitation. The clinical course and the long QTc interval with deep inverted T wave were completely normalized 4 weeks after. He continued on triple antibiotic therapy for 45 days with a good revolution. The clinical features and the possible mechanisms of QT prolongation (inflammation, infection of this patient are discussed.

The relationship between everyday problem solving and inconsistency in reaction time in older adults.

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Burton, Catherine L; Strauss, Esther; Hultsch, David F; Hunter, Michael A

2009-09-01

The purpose of the present study was to investigate whether inconsistency in reaction time (RT) is predictive of older adults' ability to solve everyday problems. A sample of 304 community dwelling non-demented older adults, ranging in age from 62 to 92, completed a measure of everyday problem solving, the Everyday Problems Test (EPT). Inconsistency in latencies across trials was assessed on four RT tasks. Performance on the EPT was found to vary according to age and cognitive status. Both mean latencies and inconsistency were significantly associated with EPT performance, such that slower and more inconsistent RTs were associated with poorer everyday problem solving abilities. Even after accounting for age, education, and mean level of performance, inconsistency in reaction time continued to account for a significant proportion of the variance in EPT scores. These findings suggest that indicators of inconsistency in RT may be of functional relevance.

Prolonged social withdrawal disorder: a hikikomori case in Spain.

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Ovejero, Santiago; Caro-Cañizares, Irene; de León-Martínez, Victoria; Baca-Garcia, Enrique

2014-09-01

The Japanese term hikikomori means literally 'to be confined'. Social withdrawal can be present in severe psychiatric disorders; however, in Japan, hikikomori is a defined nosologic entity. There have been only a few reported cases in occidental culture. We present a case report of a Spanish man with prolonged social withdrawal lasting for 4 years. This is a case of prolonged social withdrawal not bound to culture, as well as the second case of hikikomori reported in Spain. We propose prolonged social withdrawal disorder as a disorder not linked to culture, in contrast to hikikomori. Further documentation of this disorder is still needed to encompass all cases reported in Japan and around the world. © The Author(s) 2013.

Theoretical Time Dependent Thermal Neutron Spectra and Reaction Rates in H{sub 2}O and D{sub 2}O

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Purohit, S N

1966-04-15

The early theoretical and experimental time dependent neutron thermalization studies were limited to the study of the transient spectrum in the diffusion period. The recent experimental measurements of the time dependent thermal neutron spectra and reaction rates, for a number of moderators, have generated considerable interest in the study of the time dependent Boltzmann equation. In this paper we present detailed results for the time dependent spectra and the reaction rates for resonance detectors using several scattering models of H{sub 2}O and D{sub 2}O. This study has been undertaken in order to interpret the integral time dependent neutron thermalization experiments in liquid moderators which have been performed at the AB Atomenergi. The proton gas and the deuteron gas models are inadequate to explain the measured reaction rates in H{sub 2}O and D{sub 2}O. The bound models of Nelkin for H{sub 2}O and of Butler for D{sub 2}O give much better agreement with the experimental results than the gas models. Nevertheless, some disagreement between theoretical and experimental results still persists. This study also indicates that the bound model of Butler and the effective mass 3. 6 gas model of Brown and St. John give almost identical reaction rates. It is also surprising to note that the calculated reaction rate for Cd for the Butler model appears to be in better agreement with the experimental results of D{sub 2}O than of the Nelkin model with H{sub 2}O experiments. The present reaction rate studies are sensitive enough so as to distinguish between the gas model and the bound model of a moderator. However, to investigate the details of a scattering law (such as the effect of the hindered rotations in H{sub 2}O and D{sub 2}O and the weights of different dynamical modes) with the help of these studies would require further theoretical as well as experimental investigations. Theoretical results can be further improved by improving the source for thermal neutrons, the

Heart Rate Variability Frequency Domain Alterations among Healthy Nurses Exposed to Prolonged Work Stress.

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Borchini, Rossana; Veronesi, Giovanni; Bonzini, Matteo; Gianfagna, Francesco; Dashi, Oriana; Ferrario, Marco Mario

2018-01-11

The deregulation of the autonomic nervous system assessed through the heart rate variability (HRV) analysis is a promising pathway linking work stress and cardiovascular diseases. We aim to investigate the associations between HRV High Frequency (HF) and Low Frequency (LF) powers and work stress in a sample of 36 healthy nurses. Perceived work stress was assessed twice one year apart, using the Job Content and Effort Reward Imbalance questionnaires. This allows to classify nurses in three exposure groups: "prolonged high stress" (PHS), "recent high stress" (RHS) and "stable low stress" (SLS). A 24-h ECG monitoring was later performed during a working day (WD) and a subsequent resting day (RD). Statistically significantly lower ( p working periods. In the subsequent resting periods, HF means showed increases over time in the RHS (beta = +0.41, p working and resting periods. Our study evidences that both prolonged and recent perceived high work stress were associated with a reduction of HF and LF powers during work. In addition, prolonged stress was associated with a lack of recovery during not-working and resting periods.

Effects of upper respiratory tract illnesses, ibuprofen and caffeine on reaction time and alertness.

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Smith, Andrew P; Nutt, David J

2014-05-01

Compared with healthy individuals, those with upper respiratory tract illnesses (URTIs) report reduced alertness and have slower reaction times. It is important to evaluate medication that can remove this behavioural malaise. The aim of this study was to compare the effects of a combination of ibuprofen plus caffeine with ibuprofen and caffeine alone, and placebo on malaise associated with URTIs, as measured by psychomotor performance and mood testing. Volunteers were randomly assigned to one of four medication conditions as follows: 200 mg ibuprofen and 100 mg caffeine; 200 mg ibuprofen; 100 mg caffeine; placebo. A single oral dose was given and testing followed for 3 h. Efficacy variables were based on the volunteers' performance, measured by psychomotor performance and mood. The pre-drug results confirmed that those with an URTI had a more negative mood and impaired performance. Results from the simple reaction time task, at both 55- and 110-min post-dosing, showed that a single-dose of caffeinated products (I200/C100 and CAF100) led to significantly faster reaction times than IBU200 and placebo. These effects were generally confirmed with the other performance tasks. Subjective measures showed that the combination of ibuprofen and caffeine was superior to the other conditions. There were no serious adverse events reported, and study medication was well tolerated. The results from the post-drug assessments suggest that a combination of ibuprofen and caffeine was the optimum treatment for malaise associated with URTIs in that it had significant effects on objective performance and subjective measures.

Defining futile life-prolonging treatments through Neo-Socratic Dialogue.

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Aizawa, Kuniko; Asai, Atsushi; Bito, Seiji

2013-12-09

In Japan, people are negative towards life-prolonging treatments. Laws that regulate withholding or discontinuing life-prolonging treatments and advance directives do not exist. Physicians, however, view discontinuing life-prolonging treatments negatively due to fears of police investigations. Although ministerial guidelines were announced regarding the decision process for end-of-life care in 2007, a consensus could not be reached on the definition of end-of-life and conditions for withholding treatment. We established a forum for extended discussions and consensus building on this topic. We used the Neo-Socratic Dialogue (NSD) method which promotes philosophical discussion based on a case-study to address a question and formulate a consensus and answer in a group. The question chosen for the dialogue was: "What is a life-prolonging treatment?" A series of dialogues took place over a period of one and a half days. It was carried out by three groups in 2010 and 2011. Seven participants with diverse backgrounds were recruited per group. We analyzed the content of the discussion. Based on three case studies concerning different opinions about treatment options for an older dementia patient, a patient demanding chemotherapy, and a severely ill neonate, conditions for futile life-prolonging treatment were elucidated through NSD. Such treatments are those carried out for the sole purpose of prolonging life and are detrimental to the patient, and should be decided based foremost on the patient's lack of desire for treatment, the consensus of those involved, and through social acceptance. These arguments are essentially consistent with ones on medical futility in the United States. By expressing the objective of healthcare and the requirement of social acceptance, participants were also able to elucidate issues related to the awareness of those involved and the medical environment. Compared to the end-of-life guidelines in Japan, the objective of treatment, its effects

Ventricular Cycle Length Characteristics Estimative of Prolonged RR Interval during Atrial Fibrillation

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CIACCIO, EDWARD J.; BIVIANO, ANGELO B.; GAMBHIR, ALOK; EINSTEIN, ANDREW J.; GARAN, HASAN

2014-01-01

Background When atrial fibrillation (AF) is incessant, imaging during a prolonged ventricular RR interval may improve image quality. It was hypothesized that long RR intervals could be predicted from preceding RR values. Methods From the PhysioNet database, electrocardiogram RR intervals were obtained from 74 persistent AF patients. An RR interval lengthened by at least 250 ms beyond the immediately preceding RR interval (termed T0 and T1, respectively) was considered prolonged. A two-parameter scatterplot was used to predict the occurrence of a prolonged interval T0. The scatterplot parameters were: (1) RR variability (RRv) estimated as the average second derivative from 10 previous pairs of RR differences, T13–T2, and (2) Tm–T1, the difference between Tm, the mean from T13 to T2, and T1. For each patient, scatterplots were constructed using preliminary data from the first hour. The ranges of parameters 1 and 2 were adjusted to maximize the proportion of prolonged RR intervals within range. These constraints were used for prediction of prolonged RR in test data collected during the second hour. Results The mean prolonged event was 1.0 seconds in duration. Actual prolonged events were identified with a mean positive predictive value (PPV) of 80% in the test set. PPV was >80% in 36 of 74 patients. An average of 10.8 prolonged RR intervals per 60 minutes was correctly identified. Conclusions A method was developed to predict prolonged RR intervals using two parameters and prior statistical sampling for each patient. This or similar methodology may help improve cardiac imaging in many longstanding persistent AF patients. PMID:23998759

Intrathecal tramadol as and adjuvant in subrachnoid block to prolong the duration of analgesia

International Nuclear Information System (INIS)

Zahid, F.; Tarar, H. M.; Tariq, M.; Nazir, H.; Zafar, I.; Munir, S.

2017-01-01

Objective: To assess the effect of intrathecal tramadol added to bupivacaine to prolong the duration of analgesia in subarachnoid block for lower limb orthopedic surgeries. Study Design: Randomized controlled trial. Place and Duration of Study: Anesthesia department of Combined Military Hospital Sialkot, from Nov 2015 to Apr 2016. Material and Methods: Patients were selected by non-probability consecutive sampling. One hundred and fifty patients from American Society of Anesthesiologists (ASA) I, II and III category fulfilling inclusion criteria undergoing various lower limb orthopedic surgeries were divided into two groups by lottery system. Group tramadol bupivacaine (TB) received 25mg (1 ml) of tramadol plus 2ml (10mg) of 0.5 percent bupivacaine while group bupivacaine alone (SB) received 1 ml normal saline plus 2ml (10mg) of 0.5 percent bupivacaine. Time to first analgesia request was noted as a measure of duration of analgesia. Time of onset of sensory block level and peak sensory block level and time to reach the peak sensory block level were also noted. Quality of anesthesia was compared among two groups. Data were analyzed by using SPSS version 22. Results: Four patients were excluded from the study. The duration of anesthesia was effectively prolonged in group TB 181.56 ± 12.42 mins as compared to group SB 120.93 ± 15.54 mins. VAS score was significantly lower in group TB. Higher peak sensory block levels (T6) were achieved in group TB as compared to group SB. However time to reach the peak sensory block levels were significantly longer in group TB. (4.5 ± 0.47mins vs 3.09 ± 0.54 mins). Conclusion: This study showed that intrathecal tramadol (25mg) can safely be used along with bupivacaine in subarachnoid blockade to prolong the duration of analgesia and improve the quality of anesthesia as well. (author)

Women's experiences of becoming a mother after prolonged labour.

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Nystedt, Astrid; Högberg, Ulf; Lundman, Berit

2008-08-01

This paper is a report of a study to explore women's experiences of becoming a mother after prolonged labour. The negativity associated with a complicated labour such as prolonged labour can lead to a struggle to become a healthy mother and could restrict the process of becoming a mother. Interviews were conducted in 2004 with 10 mothers who had been through a prolonged labour with assisted vaginal or caesarean delivery 1-3 months previously. Thematic content analysis was used. Three themes were formulated, describing women's experiences as fumbling in the dark, struggling for motherhood and achieving confidence in being a mother. The difficulties and suffering involved in becoming a mother after a prolonged labour were interpreted to be like 'fumbling in the dark'. Women experienced bodily fatigue, accompanied by feelings of illness and detachment from the child. Having the child when in this condition entailed a struggle to become a mother. In spite of these experiences and the desire to achieve confidence in being a mother, the reassurance of these women regarding their capacity for motherhood was crucial: it was central to their happiness as mothers, encouraged interaction and relationship with the child, and contributed to their adaptation to motherhood. Women experiencing prolonged labour may be comparable with the experience of and recovery from illness, which could contribute to difficulties transitioning to motherhood and limit a woman's ability to be emotionally available for the child.

Rate of information processing and reaction time of aircraft pilots and non-pilots

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Werner Barkhuizen

2002-09-01

Full Text Available Reaction time and rate of information processing are cited as critical components in the make-up of pilots. A need was identified to establish the validity of various chronometric measures in the selection of pilots. Fifty-eight military and commercial pilots and twenty non-pilots were subjected to Schepers’ Computerised Information Processing Test Battery, which measures reaction time, form discrimination time, colour discrimination time, rate of information processing (perceptual and rate of information processing (conceptual. Five hypotheses and one postulate were formulated and tested. The results indicate that pilots could be differentiated from non-pilots with 92,3% accuracy. However, the results need to be cross-validated before they are used for selection. Opsomming Reaksietyd en tempo van inligtingverwerking word as kritieke komponente in die samestelling van vlieëniers beskou. ‘n Behoefte is geïdentifiseer om die geldigheid van verskeie chronometriese metinge in vlieënierskeuring te bepaal. Agt en vyftig militêre en kommersiële vlieëniers en twintig nie-vlieëniers is onderwerp aan Schepers se Gerekenariseerde Inligtingverwerkingstoets-battery wat reaksietyd, vormdiskriminasietyd, kleurdiskriminasietyd, tempo van inligtingverwerking (perseptueel en tempo van inligtingverwerking (konseptueel meet. Vyf hipoteses en een postulaat is gestel en getoets. Die resultate dui daarop dat vlieëniers met 92,3% akkuraatheid van nievlieëniers onderskei kan word. Die resultate behoort egter eers gekruisvalideer te word voordat dit finaal vir keuring gebruik kan word.

Reproducibility of frequency-dependent low frequency fluctuations in reaction time over time and across tasks.

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Liu, Zan-Zan; Qu, Hui-Jie; Tian, Zhuo-Ling; Han, Meng-Jian; Fan, Yi; Ge, Lie-Zhong; Zang, Yu-Feng; Zhang, Hang

2017-01-01

Increased levels of reaction time variability (RTV) are characteristics of sustained attention deficits. The clinical significance of RTV has been widely recognized. However, the reliability of RTV measurements has not been widely studied. The present study aimed to assess the test-retest reliability of RTV conventional measurements, e.g., the standard deviation (SD), the coefficient of variation (CV), and a new measurement called the amplitude of low frequency fluctuation (ALFF) of RT. In addition, we aimed to assess differences and similarities of these measurements between different tasks. Thirty-seven healthy college students participated in 2 tasks, i.e., an Eriksen flanker task (EFT) and a simple reaction task (SRT), twice over a mean interval of 56 days. Conventional measurements of RTV including RT-SD and RT-CV were assessed first. Then the RT time series were converted into frequency domains, and RT-ALFF was further calculated for the whole frequency band (0.0023-0.167 Hz) and for a few sub-frequency bands including Slow-6 (frequency bands (Slow-3), but SRT RT-ALFF values showed slightly higher ICC values than EFT values in lower frequency bands (Slow-5 and Slow-4). 2) RT-ALFF magnitudes in each sub-frequency band were greater for the SRT than those for the EFT. 3) The RT-ALFF in the Slow-4 of the EFT was found to be correlated with the RT-ALFF in the Slow-5 of the SRT for both two visits, but no consistently significant correlation was found between the same frequency bands. These findings reveal good test-retest reliability for conventional measurements and for the RT-ALFF of RTV. The RT-ALFF presented frequency-dependent similarities across tasks. All of our results reveal the presence of different frequency structures between the two tasks, and thus the frequency-dependent characteristics of different tasks deserve more attention in future studies.

Does a 'tight' hamstring predict low back pain reporting during prolonged standing?

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Raftry, Sean M; Marshall, Paul W M

2012-06-01

The purpose of this study was to investigate the relationship between hamstring passive stiffness and extensibility in asymptomatic individuals with the reporting of low back pain during 2-h prolonged standing. Twenty healthy participants with no history of low back pain (mean±SD, age 22.6±2.7 years, height 1.74±0.09 m, weight 76.2±14.8 kg). Low back pain (VAS score; mm) was continuously monitored during 2-h prolonged standing. Hamstring extensibility, passive stiffness, and stretch tolerance were measured before and after prolonged standing using an instrumented straight leg raise (iSLR). Ten participants reported a clinically relevant increase (Δ VAS>10mm) in low back pain during prolonged standing. Hamstring extensiblity (leg°(max)), passive stiffness (Nm.°(-1)), and stretch tolerance (VAS; mm) were no different between pain developers and non-pain developers. No changes in hamstring measures were observed following 2-h prolonged standing. No relationship was observed in this study between measures of hamstring extensibility and the reporting of low back pain during prolonged standing. There is no evidence to recommend hamstring extensibility interventions (i.e. passive stretching) as a means of reducing pain reporting in occupations requiring prolonged standing. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Immediate Effect of Neuromuscular Joint Facilitation (NJF) Treatment on Electromechanical Reaction Times of Hip Flexion.

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Huo, Ming; Wang, Hongzhao; Ge, Meng; Huang, Qiuchen; Li, Desheng; Maruyama, Hitoshi

2013-11-01

[Purpose] The aim of this study was to investigate the change in electromechanical reaction times (EMG-RT) of hip flexion of younger persons after neuromuscular joint facilitation (NJF) treatment. [Subjects] The subjects were 39 healthy young people, who were divided into two groups: a NJF group and a proprioceptive neuromuscular facilitation (PNF) group. The NJF group consisted of 16 subjects (7 males, 9 females), and the PNF group consisted of 23 subjects (10 males, 13 females). [Methods] Participants in the NJF group received NJF treatment. We measured the EMG-RT, the premotor time (PMT) and the motor time (MT) during hip flexion movement before and after the intervention in both groups. [Results] There were no significant differences among the results of the PNF group. For the NJF group, there were significant differences in PMT and EMG-RT after NJF treatment. [Conclusion] These results suggest that there is an immediate effect of NJF intervention on electromechanical reaction times of hip flexion.

Possible gabapentin and ketamine interaction causing prolonged central nervous system depression during post-operative recovery following cervical laminoplasty: a case report

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Bejnarowicz Robert P

2011-04-01

Full Text Available Abstract Introduction The drugs gabapentin and ketamine are used frequently in the peri-operative setting. There is poor documentation whether or not gabapentin and ketamine interact to cause prolonged depression of the central nervous system. Case Presentation The following is a case report in which a patient, a 58-year-old African-American man, with a history of post-traumatic stress disorder and chronic pain underwent a cervical laminoplasty procedure. The patient presented post-operatively in a dissociative state with paralysis, anarthria and preservation of consciousness. All organic causes were excluded, with the exception of prolonged central nervous system depression from a gabapentin/ketamine drug interaction. A new onset conversion disorder could also not be excluded. Conclusion Although this case by itself is not enough evidence to substantiate a true adverse reaction between gabapentin and ketamine, it is enough to warrant further investigation.

Development of time-resolved electron momentum spectroscopy. Toward real-time imaging of frontier electrons in molecular reactions

International Nuclear Information System (INIS)

Yamazaki, M.; Takahashi, M.

2016-01-01

This report will introduce a new experimental technique to readers, which we would like to propose towards advances in the field of molecular reaction dynamics. It is time-resolved electron momentum spectroscopy and aims to take in momentum space snapshots of the rapid change of molecular orbitals, which is the driving force behind any structural changes occurring in transient molecules. Following a description of the working principle of the technique, some preliminary result will be presented in order to illustrate the current performance of the apparatus. (author)

Fellatio by fruit bats prolongs copulation time.

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Min Tan

Full Text Available Oral sex is widely used in human foreplay, but rarely documented in other animals. Fellatio has been recorded in bonobos Pan paniscus, but even then functions largely as play behaviour among juvenile males. The short-nosed fruit bat Cynopterus sphinx exhibits resource defence polygyny and one sexually active male often roosts with groups of females in tents made from leaves. Female bats often lick their mate's penis during dorsoventral copulation. The female lowers her head to lick the shaft or the base of the male's penis but does not lick the glans penis which has already penetrated the vagina. Males never withdrew their penis when it was licked by the mating partner. A positive relationship exists between the length of time that the female licked the male's penis during copulation and the duration of copulation. Furthermore, mating pairs spent significantly more time in copulation if the female licked her mate's penis than if fellatio was absent. Males also show postcopulatory genital grooming after intromission. At present, we do not know why genital licking occurs, and we present four non-mutually exclusive hypotheses that may explain the function of fellatio in C. sphinx.

Variability in reaction time performance of younger and older adults.

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Hultsch, David F; MacDonald, Stuart W S; Dixon, Roger A

2002-03-01

Age differences in three basic types of variability were examined: variability between persons (diversity), variability within persons across tasks (dispersion), and variability within persons across time (inconsistency). Measures of variability were based on latency performance from four measures of reaction time (RT) performed by a total of 99 younger adults (ages 17--36 years) and 763 older adults (ages 54--94 years). Results indicated that all three types of variability were greater in older compared with younger participants even when group differences in speed were statistically controlled. Quantile-quantile plots showed age and task differences in the shape of the inconsistency distributions. Measures of within-person variability (dispersion and inconsistency) were positively correlated. Individual differences in RT inconsistency correlated negatively with level of performance on measures of perceptual speed, working memory, episodic memory, and crystallized abilities. Partial set correlation analyses indicated that inconsistency predicted cognitive performance independent of level of performance. The results indicate that variability of performance is an important indicator of cognitive functioning and aging.

Mathematical Modeling and Dynamic Simulation of Metabolic Reaction Systems Using Metabolome Time Series Data

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Kansuporn eSriyudthsak

2016-05-01

Full Text Available The high-throughput acquisition of metabolome data is greatly anticipated for the complete understanding of cellular metabolism in living organisms. A variety of analytical technologies have been developed to acquire large-scale metabolic profiles under different biological or environmental conditions. Time series data are useful for predicting the most likely metabolic pathways because they provide important information regarding the accumulation of metabolites, which implies causal relationships in the metabolic reaction network. Considerable effort has been undertaken to utilize these data for constructing a mathematical model merging system properties and quantitatively characterizing a whole metabolic system in toto. However, there are technical difficulties between benchmarking the provision and utilization of data. Although hundreds of metabolites can be measured, which provide information on the metabolic reaction system, simultaneous measurement of thousands of metabolites is still challenging. In addition, it is nontrivial to logically predict the dynamic behaviors of unmeasurable metabolite concentrations without sufficient information on the metabolic reaction network. Yet, consolidating the advantages of advancements in both metabolomics and mathematical modeling remain to be accomplished. This review outlines the conceptual basis of and recent advances in technologies in both the research fields. It also highlights the potential for constructing a large-scale mathematical model by estimating model parameters from time series metabolome data in order to comprehensively understand metabolism at the systems level.

Mathematical Modeling and Dynamic Simulation of Metabolic Reaction Systems Using Metabolome Time Series Data.

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Sriyudthsak, Kansuporn; Shiraishi, Fumihide; Hirai, Masami Yokota

2016-01-01

The high-throughput acquisition of metabolome data is greatly anticipated for the complete understanding of cellular metabolism in living organisms. A variety of analytical technologies have been developed to acquire large-scale metabolic profiles under different biological or environmental conditions. Time series data are useful for predicting the most likely metabolic pathways because they provide important information regarding the accumulation of metabolites, which implies causal relationships in the metabolic reaction network. Considerable effort has been undertaken to utilize these data for constructing a mathematical model merging system properties and quantitatively characterizing a whole metabolic system in toto. However, there are technical difficulties between benchmarking the provision and utilization of data. Although, hundreds of metabolites can be measured, which provide information on the metabolic reaction system, simultaneous measurement of thousands of metabolites is still challenging. In addition, it is nontrivial to logically predict the dynamic behaviors of unmeasurable metabolite concentrations without sufficient information on the metabolic reaction network. Yet, consolidating the advantages of advancements in both metabolomics and mathematical modeling remain to be accomplished. This review outlines the conceptual basis of and recent advances in technologies in both the research fields. It also highlights the potential for constructing a large-scale mathematical model by estimating model parameters from time series metabolome data in order to comprehensively understand metabolism at the systems level.

What prolongs a butterfly's life?: Trade-offs between dormancy, fecundity and body size.

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Elena Haeler

Full Text Available In butterflies, life span often increases only at the expense of fecundity. Prolonged life span, on the other hand, provides more opportunities for oviposition. Here, we studied the association between life span and summer dormancy in two closely related species of Palearctic Meadow Brown butterflies, the endemic Maniola nurag and the widespread M. jurtina, from two climatic provenances, a Mediterranean and a Central European site, and tested the relationships between longevity, body size and fecundity. We experimentally induced summer dormancy and hence prolonged the butterflies' life in order to study the effects of such a prolonged life. We were able to modulate longevity only in Mediterranean females by rearing them under summer photoperiodic conditions (light 16 h : dark 8 h, thereby more than doubling their natural life span, to up to 246 days. Central European individuals kept their natural average live span under all treatments, as did Mediterranean individuals under autumn treatment (light 11: dark 13. Body size only had a significant effect in the smaller species, M. nurag, where it affected the duration of dormancy and lifetime fecundity. In the larger species, M. jurtina, a prolonged adult life span did, surprisingly, not convey any fecundity loss. In M. nurag, which generally deposited fewer eggs, extended life had a fecundity cost. We conclude that Mediterranen M. jurtina butterflies have an extraordinary plasticity in aging which allows them to extend life span in response to adverse environmental conditions and relieve the time limitation on egg-laying while maintaining egg production at equal levels.

Comparing Young and Elderly Serial Reaction Time Task Performance on Repeated and Random Conditions

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Fatemeh Ehsani

2012-07-01

Full Text Available Objectives: Acquisition motor skill training in elderly is at great importance. The main purpose of this study was to compare young and elderly performance in serial reaction time task on different repeated and random conditions. Methods & Materials: A serial reaction time task by using software was applied for studying motor learning in 30 young and 30 elderly. Each group divided randomly implicitly and explicitly into subgroups. A task 4 squares with different colors appeared on the monitor and subjects were asked to press its defined key immediately after observing it. Subjects practiced 8 motor blocks (4 repeated blocks, then 2 random blocks and 2 repeated blocks. Block time that was dependent variable measured and Independent-samples t- test with repeated ANOVA measures were used in this test. Results: young groups performed both repeated and random sequences significantly faster than elderly (P0.05. Explicit older subgroup performed 7,8 blocks slower than 6 block with a significant difference (P<0.05. Conclusion: Young adults discriminate high level performance than elderly in both repeated and random practice. Elderly performed random practice better than repeated practice.

Time-resolved FTIR [Fourier transform infrared] emission studies of laser photofragmentation and chain reactions

International Nuclear Information System (INIS)

Leone, S.R.

1990-01-01

Recent progress is described resulting from the past three years of DOE support for studies of combustion-related photofragmentation dynamics, energy transfer, and reaction processes using a time-resolved Fourier transform infrared (FTIR) emission technique. The FTIR is coupled to a high repetition rate excimer laser which produces radicals by photolysis to obtain novel, high resolution measurements on vibrational and rotational state dynamics. The results are important for the study of numerous radical species relevant to combustion processes. The method has been applied to the detailed study of photofragmentation dynamics in systems such as acetylene, which produces C 2 H; chlorofluoroethylene to study the HF product channel; vinyl chloride and dichloroethylene, which produce HCl; acetone, which produces CO and CH 3 ; and ammonia, which produces NH 2 . In addition, we have recently demonstrated use of the FTIR technique for preliminary studies of energy transfer events under near single collision conditions, radical-radical reactions, and laser-initiated chain reaction processes

Integrating reaction and analysis: investigation of higher-order reactions by cryogenic trapping

Directory of Open Access Journals (Sweden)

Skrollan Stockinger

2013-09-01

Full Text Available A new approach for the investigation of a higher-order reaction by on-column reaction gas chromatography is presented. The reaction and the analytical separation are combined in a single experiment to investigate the Diels–Alder reaction of benzenediazonium-2-carboxylate as a benzyne precursor with various anthracene derivatives, i.e. anthracene, 9-bromoanthracene, 9-anthracenecarboxaldehyde and 9-anthracenemethanol. To overcome limitations of short reaction contact times at elevated temperatures a novel experimental setup was developed involving a cooling trap to achieve focusing and mixing of the reactants at a defined spot in a fused-silica capillary. This trap functions as a reactor within the separation column in the oven of a gas chromatograph. The reactants are sequentially injected to avoid undefined mixing in the injection port. An experimental protocol was developed with optimized injection intervals and cooling times to achieve sufficient conversions at short reaction times. Reaction products were rapidly identified by mass spectrometric detection. This new approach represents a practical procedure to investigate higher-order reactions at an analytical level and it simultaneously provides valuable information for the optimization of the reaction conditions.

Prismatic displacement effect of progressive multifocal glasses on reaction time and accuracy in elderly people.

Science.gov (United States)

Ellison, Ashton C; Campbell, A John; Robertson, M Clare; Sanderson, Gordon F

2014-01-01

Multifocal glasses (bifocals, trifocals, and progressives) increase the risk of falling in elderly people, but how they do so is unclear. To explain why glasses with progressive addition lenses increase the risk of falls and whether this can be attributed to false projection, this study aimed to 1) map the prismatic displacement of a progressive lens, and 2) test whether this displacement impaired reaction time and accuracy. The reaction times of healthy ≥75-year-olds (31 participants) were measured when grasping for a bar and touching a black line. Participants performed each test twice, wearing their progressives and new, matched single vision (distance) glasses in random order. The line and bar targets were positioned according to the maximum and minimum prismatic displacement effect through the progressive lens, mapped using a focimeter. Progressive spectacle lenses have large areas of prismatic displacement in the central visual axis and edges. Reaction time was faster for progressives compared with single vision glasses with a centrally-placed horizontal grab bar (mean difference 101 ms, P=0.011 [repeated measures analysis]) and a horizontal black line placed 300 mm below center (mean difference 80 ms, P=0.007). There was no difference in accuracy between the two types of glasses. Older people appear to adapt to the false projection of progressives in the central visual axis. This adaptation means that swapping to new glasses or a large change in prescription may lead to a fall. Frequently updating glasses may be more beneficial.

Enzyme reactions and their time resolved measurements

International Nuclear Information System (INIS)

Hajdu, Janos

1990-01-01

This paper discusses experimental strategies in data collection with the Laue method and summarises recent results using synchrotron radiation. Then, an assessment is made of the progress towards time resolved studies with protein crystals and the problems that remain. The paper consists of three parts which respectively describe some aspects of Laue diffraction, recent examples of structural results from Laue diffraction, and kinetic Laue crystallography. In the first part, characteristics of Laue diffraction is discussed first, focusing on the harmonics problems, spatials problem, wavelength normalization, low resolution hole, data completeness, and uneven coverage of reciprocal space. Then, capture of the symmetry unique reflection set is discussed focusing on the effect of wavelength range on the number of reciprocal lattice points occupying diffracting positions, effect of crystal to film distance and the film area and shape on the number of reflections captured, and effect of crystal symmetry on the number of unique reflections within the number of reflections captured. The second part addresses the determination of the structure of turkey egg white lysozyme, and calcium binding in tomato bushy stunt virus. The third part describes the initiation of reactions in enzyme crystals, picosecond Laue diffraction at high energy storage rings, and detectors. (N.K.)

Reaction rate and composition dependence of the stability of thermonuclear burning on accreting neutron stars

International Nuclear Information System (INIS)

Keek, L.; Cyburt, R. H.; Heger, A.

2014-01-01

The stability of thermonuclear burning of hydrogen and helium accreted onto neutron stars is strongly dependent on the mass accretion rate. The burning behavior is observed to change from Type I X-ray bursts to stable burning, with oscillatory burning occurring at the transition. Simulations predict the transition at a 10 times higher mass accretion rate than observed. Using numerical models we investigate how the transition depends on the hydrogen, helium, and CNO mass fractions of the accreted material, as well as on the nuclear reaction rates of 3α and the hot-CNO breakout reactions 15 O(α, γ) 19 Ne and 18 Ne(α, p) 21 Na. For a lower hydrogen content the transition is at higher accretion rates. Furthermore, most experimentally allowed reaction rate variations change the transition accretion rate by at most 10%. A factor 10 decrease of the 15 O(α, γ) 19 Ne rate, however, produces an increase of the transition accretion rate of 35%. None of our models reproduce the transition at the observed rate, and depending on the true 15 O(α, γ) 19 Ne reaction rate, the actual discrepancy may be substantially larger. We find that the width of the interval of accretion rates with marginally stable burning depends strongly on both composition and reaction rates. Furthermore, close to the stability transition, our models predict that X-ray bursts have extended tails where freshly accreted fuel prolongs nuclear burning.

Strength of figure-ground activity in monkey primary visual cortex predicts saccadic reaction time in a delayed detection task.

Science.gov (United States)

Supèr, Hans; Lamme, Victor A F

2007-06-01

When and where are decisions made? In the visual system a saccade, which is a fast shift of gaze toward a target in the visual scene, is the behavioral outcome of a decision. Current neurophysiological data and reaction time models show that saccadic reaction times are determined by a build-up of activity in motor-related structures, such as the frontal eye fields. These structures depend on the sensory evidence of the stimulus. Here we use a delayed figure-ground detection task to show that late modulated activity in the visual cortex (V1) predicts saccadic reaction time. This predictive activity is part of the process of figure-ground segregation and is specific for the saccade target location. These observations indicate that sensory signals are directly involved in the decision of when and where to look.

Cell phone ringtone, but not landline phone ringtone, affects complex reaction time

OpenAIRE

Radosław Zajdel; Justyna Zajdel; Janusz Śmigielski; Dariusz Nowak

2013-01-01

Introduction: Legislation systems of most countries prohibited using the handheld mobile phone while driving due to the fact that it disturbs concentration and causes hand involvement. Every phone owner is accustomed to the ringtone of his phone and almost involuntarily endeavors to pick it up or check who calls. This engages one’s psychomotor skills, which in our opinion contributes to the attenuation of reaction time needed for performing other crucial functions. Objectives: The aim of the ...

Acute glucoregulatory and vascular outcomes of three strategies for interrupting prolonged sitting time in postmenopausal women: A pilot, laboratory-based, randomized, controlled, 4-condition, 4-period crossover trial.

Directory of Open Access Journals (Sweden)

Jacqueline Kerr

Full Text Available Prolonged sitting is associated with cardiometabolic and vascular disease. Despite emerging evidence regarding the acute health benefits of interrupting prolonged sitting time, the effectiveness of different modalities in older adults (who sit the most is unclear.In preparation for a future randomized controlled trial, we enrolled 10 sedentary, overweight or obese, postmenopausal women (mean age 66 years ±9; mean body mass index 30.6 kg/m2 ±4.2 in a 4-condition, 4-period crossover feasibility pilot study in San Diego to test 3 different sitting interruption modalities designed to improve glucoregulatory and vascular outcomes compared to a prolonged sitting control condition. The interruption modalities included: a 2 minutes standing every 20 minutes; b 2 minutes walking every hour; and c 10 minutes standing every hour. During each 5-hr condition, participants consumed two identical, standardized meals. Blood samples, blood pressure, and heart rate were collected every 30 minutes. Endothelial function of the superficial femoral artery was measured at baseline and end of each 5-hr condition using flow-mediated dilation (FMD. Participants completed each condition on separate days, in randomized order. This feasibility pilot study was not powered to detect statistically significant differences in the various outcomes, however, analytic methods (mixed models were used to test statistical significance within the small sample size.Nine participants completed all 4 study visits, one participant completed 3 study visits and then was lost to follow up. Net incremental area under the curve (iAUC values for postprandial plasma glucose and insulin during the 5-hr sitting interruption conditions were not significantly different compared to the control condition. Exploratory analyses revealed that the 2-minute standing every 20 minutes and the 2-minute walking every hour conditions were associated with a significantly lower glycemic response to the second

Diverse definitions of prolonged labour and its consequences with sometimes subsequent inappropriate treatment

Science.gov (United States)

2014-01-01

Background Prolonged labour very often causes suffering from difficulties that may have lifelong implications. This study aimed to explore the prevalence and treatment of prolonged labour and to compare birth outcome and women’s experiences of prolonged and normal labour. Method Women with spontaneous onset of labour, living in a Swedish county, were recruited two months after birth, to a cross-sectional study. Women (n = 829) completed a questionnaire that investigated socio-demographic and obstetric background, birth outcome and women’s feelings and experiences of birth. The prevalence of prolonged labour, as defined by a documented ICD-code and inspection of partogram was calculated. Four groups were identified; women with prolonged labour as identified by documented ICD-codes or by partogram inspection but no ICD-code; women with normal labour augmented with oxytocin or not. Results Every fifth woman experienced a prolonged labour. The prevalence with the documented ICD-code was (13%) and without ICD-code but positive partogram was (8%). Seven percent of women with prolonged labour were not treated with oxytocin. Approximately one in three women (28%) received oxytocin augmentation despite having no evidence of prolonged labour. The length of labour differed between the four groups of women, from 7 to 23 hours. Women with a prolonged labour had a negative birth experience more often (13%) than did women who had a normal labour (3%) (P women with prolonged labour were emergency Caesarean section (OR 9.0, 95% CI 1.2-3.0) and to strongly agree with the following statement ‘My birth experience made me decide not to have any more children’ (OR 41.3, 95% CI 4.9-349.6). The factors that contributed most strongly to a negative birth experience in women with normal labour were less agreement with the statement ‘It was exiting to give birth’ (OR 0.13, 95% CI 0.34-0.5). Conclusions There is need for increased clinical skill in identification and classification

Improvement of attention span and reaction time with hyperbaric oxygen treatment in patients with toxic injury due to mold exposure.

Science.gov (United States)

Ezra, N; Dang, K; Heuser, G

2011-01-01

It is, by now, well established that mold toxins (mycotoxins) can cause significant adverse health effects. In this study, 15 subjects who developed an attention deficit disorder (ADD) and slowing of reaction time at the time of exposure to mold toxins were identified. Deficits in attention span and reaction time were documented not only by taking a careful history, but also by performing a Test of Variables of Attention (TOVA). The TOVA test provides an objective measure of these two variables. It was found that mold-exposed subjects show statistically significant decreases in attention span and significant increases in reaction time to stimuli compared to controls. After ten sessions of hyperbaric oxygen treatment (HBOT), a statistically significant improvement was seen in both measures. This preliminary study suggests promising outcomes in treating mold-exposed patients with hyperbaric oxygen.

Prolonged fasting activates Nrf2 in post-weaned elephant seals.

Science.gov (United States)

Vázquez-Medina, José Pablo; Soñanez-Organis, José G; Rodriguez, Ruben; Viscarra, Jose A; Nishiyama, Akira; Crocker, Daniel E; Ortiz, Rudy M

2013-08-01

Elephant seals naturally experience prolonged periods of absolute food and water deprivation (fasting). In humans, rats and mice, prolonged food deprivation activates the renin-angiotensin system (RAS) and increases oxidative damage. In elephant seals, prolonged fasting activates RAS without increasing oxidative damage likely due to an increase in antioxidant defenses. The mechanism leading to the upregulation of antioxidant defenses during prolonged fasting remains elusive. Therefore, we investigated whether prolonged fasting activates the redox-sensitive transcription factor Nrf2, which controls the expression of antioxidant genes, and if such activation is potentially mediated by systemic increases in RAS. Blood and skeletal muscle samples were collected from seals fasting for 1, 3, 5 and 7 weeks. Nrf2 activity and nuclear content increased by 76% and 167% at week 7. Plasma angiotensin II (Ang II) and transforming growth factor β (TGF-β) were 5000% and 250% higher at week 7 than at week 1. Phosphorylation of Smad2, an effector of Ang II and TGF signaling, increased by 120% at week 7 and by 84% in response to intravenously infused Ang II. NADPH oxidase 4 (Nox4) mRNA expression, which is controlled by smad proteins, increased 430% at week 7, while Nox4 protein expression, which can activate Nrf2, was 170% higher at week 7 than at week 1. These results demonstrate that prolonged fasting activates Nrf2 in elephant seals and that RAS stimulation can potentially result in increased Nox4 through Smad phosphorylation. The results also suggest that Nox4 is essential to sustain the hormetic adaptive response to oxidative stress in fasting seals.

Task modulation of the effects of brightness on reaction time and response force.

Science.gov (United States)

Jaśkowski, Piotr; Włodarczyk, Dariusz

2006-08-01

Van der Molen and Keuss [van der Molen, M.W., Keuss, P.J.G., 1979. The relationship between reaction time and intensity in discrete auditory tasks. Quarterly Journal of Experimental Psychology 31, 95-102; van der Molen, M.W., Keuss, P.J.G., 1981. Response selection and the processing of auditory intensity. Quarterly Journal of Experimental Psychology 33, 177-184] showed that paradoxically long reaction times (RT) occur with extremely loud auditory stimuli when the task is difficult (e.g. needs a response choice). It was argued that this paradoxical behavior of RT is due to active suppression of response prompting to prevent false responses. In the present experiments, we demonstrated that such an effect can also occur for visual stimuli provided that they are large enough. Additionally, we showed that response force exerted by participants on response keys monotonically grew with intensity for large stimuli but was independent of intensity for small visual stimuli. Bearing in mind that only large stimuli are believed to be arousing this pattern of results supports the arousal interpretation of the negative effect of loud stimuli on RT given by van der Molen and Keuss.

AORN Ergonomic Tool 4: Solutions for Prolonged Standing in Perioperative Settings.

Science.gov (United States)

Hughes, Nancy L; Nelson, Audrey; Matz, Mary W; Lloyd, John

2011-06-01

Prolonged standing during surgical procedures poses a high risk of causing musculoskeletal disorders, including back, leg, and foot pain, which can be chronic or acute in nature. Ergonomic Tool 4: Solutions for Prolonged Standing in Perioperative Settings provides recommendations for relieving the strain of prolonged standing, including the use of antifatigue mats, supportive footwear, and sit/stand stools, that are based on well-accepted ergonomic safety concepts, current research, and access to new and emerging technology. Published by Elsevier Inc.

The difference between the perception of absolute and relative motion: A reaction time study

NARCIS (Netherlands)

J.B.J. Smeets (Jeroen); E. Brenner (Eli)

1994-01-01

textabstractWe used a reaction-time paradigm to examine the extent to which motion detection depends on relative motion. In the absence of relative motion, the responses could be described by a simple model based on the detection of a fixed change in position. If relative motion was present, the

Tetrodotoxin-Bupivacaine-Epinephrine Combinations for Prolonged Local Anesthesia

Directory of Open Access Journals (Sweden)

Christina Bognet

2011-12-01

Full Text Available Currently available local anesthetics have analgesic durations in humans generally less than 12 hours. Prolonged-duration local anesthetics will be useful for postoperative analgesia. Previous studies showed that in rats, combinations of tetrodotoxin (TTX with bupivacaine had supra-additive effects on sciatic block durations. In those studies, epinephrine combined with TTX prolonged blocks more than 10-fold, while reducing systemic toxicity. TTX, formulated as Tectin, is in phase III clinical trials as an injectable systemic analgesic for chronic cancer pain. Here, we examine dose-duration relationships and sciatic nerve histology following local nerve blocks with combinations of Tectin with bupivacaine 0.25% (2.5 mg/mL solutions, with or without epinephrine 5 µg/mL (1:200,000 in rats. Percutaneous sciatic blockade was performed in Sprague-Dawley rats, and intensity and duration of sensory blockade was tested blindly with different Tectin-bupivacaine-epinephrine combinations. Between-group comparisons were analyzed using ANOVA and post-hoc Sidak tests. Nerves were examined blindly for signs of injury. Blocks containing bupivacaine 0.25% with Tectin 10 µM and epinephrine 5 µg/mL were prolonged by roughly 3-fold compared to blocks with bupivacaine 0.25% plain (P < 0.001 or bupivacaine 0.25% with epinephrine 5 µg/mL (P < 0.001. Nerve histology was benign for all groups. Combinations of Tectin in bupivacaine 0.25% with epinephrine 5 µg/mL appear promising for prolonged duration of local anesthesia.

MRI findings of prolonged post-traumatic sternal pain

International Nuclear Information System (INIS)

Grosse, Alexandra; Grosse, Claudia; Anderson, Suzanne; Steinbach, Lynne

2007-01-01

The objective of this study was to characterize the different causes of prolonged sternal pain following thoracic trauma with involvement of the sternum and to define criteria for sternal nonunion diagnosis using MRI. Five patients with abnormalities of the sternum were evaluated for prolonged sternal pain following thoracic trauma using MRI. MR images were evaluated by two radiologists in consensus. The patients were selected from the radiology database, which included 8 patients with post-traumatic prolonged sternal pain. Two patients (n = 2) revealed a sternal nonunion after sternal fracture. One patient had a sternal fracture with delayed union and minor displacement of the sternal halves. Abnormal signal intensity alterations adjacent to and within the manubrio-sternal joint were evident in 2 patients and considered due to trauma-related changes in the manubrio-sternal joint. The 3 patients who were not included in the study had no abnormalities of the sternum: 1 of them proved to have a well-healed sternal fracture and nonunion of a rib fracture, 1 had subtle Tietze's syndrome, and 1 patient revealed no pathological findings on imaging. Various factors may be responsible for prolonged sternal pain following thoracic trauma, and these can be viewed with MRI. In cases of sternal nonunion there was common fluid-like signal in the fracture interspace between the bony edges, and the bone marrow adjacent to the nonunion showed altered signal intensity. MRI identified sternal nonunion and other trauma-related abnormalities of the sternum following chest trauma. (orig.)

Accuracy of real-time polymerase chain reaction for Toxoplasma gondii in amniotic fluid.

Science.gov (United States)

Wallon, Martine; Franck, Jacqueline; Thulliez, Philippe; Huissoud, Cyril; Peyron, François; Garcia-Meric, Patricia; Kieffer, François

2010-04-01

To provide clinicians with information about the accuracy of real-time polymerase chain reaction (PCR) analysis of amniotic fluid for the prenatal diagnosis of congenital Toxoplasma infection. This was a prospective cohort study of women with Toxoplasma infection identified by prenatal screening in three centers routinely carrying out real-time PCR for the detection of Toxoplasma gondii in amniotic fluid. The data available were gestational age at maternal infection, types and dates of maternal treatment, results of amniocentesis and neonatal work-up and definitive infectious status of the child. We estimated sensitivity, specificity and positive and negative predictive values both overall and per trimester of pregnancy at the time of maternal infection. Polymerase chain reaction analysis was carried out on amniotic fluid for 261 of the 377 patients included (69%). It was accurate with the exception of four negative results in children who were infected. Overall sensitivity and negative predictive value were 92.2% (95% confidence interval [CI] 81-98%) and 98.1% (95% CI 95-99.5%), respectively. There was no significant association with the trimester of pregnancy during which maternal infection occurred. Specificity and positive predictive values of 100% were obtained for all trimesters. Real-time PCR analysis significantly improves the detection of T. gondii on amniotic fluid. It provides an accurate tool to predict fetal infection and to decide on appropriate treatment and surveillance. However, postnatal follow-up remains necessary in the first year of life to fully exclude infection in children for whom PCR results were negative. III.

The driver and passenger effects of isocitrate dehydrogenase 1 and 2 mutations in oncogenesis and survival prolongation.

Science.gov (United States)

Molenaar, Remco J; Radivoyevitch, Tomas; Maciejewski, Jaroslaw P; van Noorden, Cornelis J F; Bleeker, Fonnet E

2014-12-01

Mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) are key events in the development of glioma, acute myeloid leukemia (AML), chondrosarcoma, intrahepatic cholangiocarcinoma (ICC), and angioimmunoblastic T-cell lymphoma. They also cause D-2-hydroxyglutaric aciduria and Ollier and Maffucci syndromes. IDH1/2 mutations are associated with prolonged survival in glioma and in ICC, but not in AML. The reason for this is unknown. In their wild-type forms, IDH1 and IDH2 convert isocitrate and NADP(+) to α-ketoglutarate (αKG) and NADPH. Missense mutations in the active sites of these enzymes induce a neo-enzymatic reaction wherein NADPH reduces αKG to D-2-hydroxyglutarate (D-2HG). The resulting D-2HG accumulation leads to hypoxia-inducible factor 1α degradation, and changes in epigenetics and extracellular matrix homeostasis. Such mutations also imply less NADPH production capacity. Each of these effects could play a role in cancer formation. Here, we provide an overview of the literature and discuss which downstream molecular effects are likely to be the drivers of the oncogenic and survival-prolonging properties of IDH1/2 mutations. We discuss interactions between mutant IDH1/2 inhibitors and conventional therapies. Understanding of the biochemical consequences of IDH1/2 mutations in oncogenesis and survival prolongation will yield valuable information for rational therapy design: it will tell us which oncogenic processes should be blocked and which "survivalogenic" effects should be retained. Copyright © 2014 Elsevier B.V. All rights reserved.

Reaction of chickens to graduated length of exposure to stress

Science.gov (United States)

Nvota, J.; Grom, A.; Faberova, A.

1980-01-01

The reactions of 60 day old chickens Arbor Acres 60 X Vantress to immobilization stress lasting 1/2, 1, 2, 4 hours and to application of ACTH, manifested by activity changes in the systems hypophysis-adrenal gland and hypophysis-thyroid gland were studied. The highest activity increase in the two neuro-endocrine systems of the chickens was found to occur after 1/2 hour exposure to stress. With prolonged stress the responses weakened and after 4 hours most of the values gradually regressed to their initial level. The responses of both systems were synchronized. Reactions of the chickens differed from those of laboratory rats in which an increased activity of the hypophysis-adrenal gland system coincided with attenuation of the hypophysis-thyroid gland system.

Binaural Sound Reduces Reaction Time in a Virtual Reality Search Task

DEFF Research Database (Denmark)

Høeg, Emil Rosenlund; Gerry, Lynda; Thomsen, Lui Albæk

2017-01-01

Salient features in a visual search task can direct attention and increase competency on these tasks. Simple cues, such as color change in a salient feature, called the "pop-out effect" can increase task solving efficiency [6]. Previous work has shown that nonspatial auditory signals temporally...... synched with a pop-out effect can improve reaction time in a visual search task, called the "pip and pop effect" [14]. This paper describes a within-group study on the effect of audiospatial attention in virtual reality given a 360-degree visual search. Three cue conditions were compared (no sound, stereo...

Physiology Of Prolonged Bed Rest

Science.gov (United States)

Greenleaf, John E.

1991-01-01

Report describes physiological effects of prolonged bed rest. Rest for periods of 24 hours or longer deconditions body to some extent; healing proceeds simultaneously with deconditioning. Report provides details on shifts in fluid electrolytes and loss of lean body mass, which comprises everything in body besides fat - that is, water, muscle, and bone. Based on published research.

Age and Sex Differences in Intra-Individual Variability in a Simple Reaction Time Task

Science.gov (United States)

Ghisletta, Paolo; Renaud, Olivier; Fagot, Delphine; Lecerf, Thierry; de Ribaupierre, Anik

2018-01-01

While age effects in reaction time (RT) tasks across the lifespan are well established for level of performance, analogous findings have started appearing also for indicators of intra-individual variability (IIV). Children are not only slower, but also display more variability than younger adults in RT. Yet, little is known about potential…

Metabolic responses to prolonged work during treadmill and water immersion running.

Science.gov (United States)

Frangolias, D D; Rhodes, E C; Taunton, J E; Belcastro, A N; Coutts, K D

2000-12-01

The primary aim of this study was to compare the physiological responses to prolonged treadmill (TM) and water immersion to the neck (WI) running at threshold intensity. Ten endurance runners performed TM and WI running VO2max tests. Subjects completed submaximal performance tests at ventilatory threshold (Tvent) intensities under TM and WI conditions and responses at 15 and 42 minutes examined. VO2 was lower in WI (p<0.05) at maximal effort and Tvent. The Tvent VO2 intensities interpolated from the TM and WI VO2max tests were performed in both TM (i.e., TM@TM(tvent),TM@WI(tvent), corresponding to 77.6 and 71.3% respectively of TM VO2max) and WI conditions (i.e., WI@TM(tvent), WI@WI(tvent), corresponding to 85.5% and 78.2% respectively of WI VO2max). Each of the dependent variables was analyzed using a 3-way repeated measures ANOVA (2 conditions X 2 exercise intensities X 7 time points during exercise). VO2max values were significantly lower in the WI (52.4(5.1) ml.kg(-1) min(-1)) versus TM (59.7(6.5) ml.kg(-1) min(-1)) condition. VO2 during submaximal tests were similar during the TM and WI conditions. HR and [BLa] responses to exercise at and above WI(tvent) were similar during short-term exercise, but values tended to be lower during prolonged exercise in the WI condition. There were no statistical differences in VE responses in the 2 conditions, however as with HR and [BLa] an upward trend was noted with TM exercise over the 42 minute duration of the tests. RPE at WI(tvent) was similar for TM and WI exercise sessions, however, RPE at TM(tvent) was higher during WI compared to TM running. Cardiovascular drift was observed during prolonged TM but not WI running. Results suggest differences in metabolic responses to prolonged submaximal exercise in WI, however it can be used effectively for cross training.

The influence of prolonged gamma irradiation on morpho functional indexes of blood capillaries of ovary in 20-day foetuses white rat

International Nuclear Information System (INIS)

Ablekovskaya, O.N.; Amvros'ev, A.P.

1999-01-01

It was studied the character and direction of structural transformations of blood capillaries of micro circulatory channel of 20-days white rat foetus in normal conditions and after prolonged action of gamma-radiation in the whole period of embryogenesis (absorbed dose 0,43 Gy).The peculiarities of reactions of hemo capillaries and their cell structure to gamma-rays action in embryogenesis were revealed. It was shown the decrease of diameters of capillaries, diminution of section area of cytoplasm of endotheliocytes, extension of the size of nuclei of these cells. Polyploid endotheliocytes were found in the experimental conditions. Prenatal irradiation in doses leaded to reduction of the number of microvessels and mitochondria in cytoplasm of cells of blood capillaries in ovary of rat foetus. These results revealed that low dose prolonged action of gamma-radiation during the period of embryogenesis changed the morphological parameters of important synthetic, transport and energy processes in capillary cells of ovary in fetal period of ontogenesis

Reaction Times to Consecutive Automation Failures: A Function of Working Memory and Sustained Attention.

Science.gov (United States)

Jipp, Meike

2016-12-01

This study explored whether working memory and sustained attention influence cognitive lock-up, which is a delay in the response to consecutive automation failures. Previous research has demonstrated that the information that automation provides about failures and the time pressure that is associated with a task influence cognitive lock-up. Previous research has also demonstrated considerable variability in cognitive lock-up between participants. This is why individual differences might influence cognitive lock-up. The present study tested whether working memory-including flexibility in executive functioning-and sustained attention might be crucial in this regard. Eighty-five participants were asked to monitor automated aircraft functions. The experimental manipulation consisted of whether or not an initial automation failure was followed by a consecutive failure. Reaction times to the failures were recorded. Participants' working-memory and sustained-attention abilities were assessed with standardized tests. As expected, participants' reactions to consecutive failures were slower than their reactions to initial failures. In addition, working-memory and sustained-attention abilities enhanced the speed with which participants reacted to failures, more so with regard to consecutive than to initial failures. The findings highlight that operators with better working memory and sustained attention have small advantages when initial failures occur, but their advantages increase across consecutive failures. The results stress the need to consider personnel selection strategies to mitigate cognitive lock-up in general and training procedures to enhance the performance of low ability operators. © 2016, Human Factors and Ergonomics Society.

Manual Choice Reaction Times in the Rate-Domain

Directory of Open Access Journals (Sweden)

Chris eHarris

2014-06-01

Full Text Available Over the last 150 years, human manual reaction times (RTs have been recorded countless times. Yet, our understanding of them remains remarkably poor. RTs are highly variable with positively skewed frequency distributions, often modelled as an inverse Gaussian distribution reflecting a stochastic rise to threshold (diffusion process. However, latency distribution of saccades are very close to the reciprocal Normal, suggesting that ‘rate’ (reciprocal RT may be the more fundamental variable. We explored whether this phenomenon extends to choice manual RTs. We recorded two-alternative choice RTs from 24 subjects, each with 4 blocks of 200 trials with two task difficulties (easy vs. difficult discrimination and two instruction sets (urgent vs. accurate. We found that rate distributions were, indeed, very close to Normal, shifting to lower rates with increasing difficulty and accuracy, and for some blocks subjects they appeared to become left-truncated, but still close to Normal. Using autoregressive techniques, we found temporal sequential dependencies for lags of at least 3. We identified a transient and steady-state component in each block. Because rates were Normal, we were able to estimate autoregressive weights using the Box-Jenkins technique, and convert to a moving average model using z-transforms to show explicit dependence on stimulus input. We also found a spatial sequential dependence for the previous 3 lags depending on whether the laterality of previous trials was repeated or alternated. This was partially dissociated from temporal dependency as it only occurred in the easy tasks. We conclude that 2-alternative choice manual RT distributions are close to reciprocal Normal and not the inverse Gaussian. This is not consistent with stochastic rise to threshold models, and we propose a simple optimality model in which reward is maximized to yield to an optimal rate, and hence an optimal time to respond. We discuss how it might be

Common genetic influences on intelligence and auditory simple reaction time in a large Swedish sample

NARCIS (Netherlands)

Madison, G.; Mosing, M.A.; Verweij, K.J.H.; Pedersen, N.L.; Ullén, F.

2016-01-01

Intelligence and cognitive ability have long been associated with chronometric performance measures, such as reaction time (RT), but few studies have investigated auditory RT in this context. The nature of this relationship is important for understanding the etiology and structure of intelligence.

Testing a potential alternative to traditional identification procedures: Reaction time-based concealed information test does not work for lineups with cooperative witnesses.

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Sauerland, Melanie; Wolfs, Andrea C F; Crans, Samantha; Verschuere, Bruno

2017-11-27

Direct eyewitness identification is widely used, but prone to error. We tested the validity of indirect eyewitness identification decisions using the reaction time-based concealed information test (CIT) for assessing cooperative eyewitnesses' face memory as an alternative to traditional lineup procedures. In a series of five experiments, a total of 401 mock eyewitnesses watched one of 11 different stimulus events that depicted a breach of law. Eyewitness identifications in the CIT were derived from longer reaction times as compared to well-matched foil faces not encountered before. Across the five experiments, the weighted mean effect size d was 0.14 (95% CI 0.08-0.19). The reaction time-based CIT seems unsuited for testing cooperative eyewitnesses' memory for faces. The careful matching of the faces required for a fair lineup or the lack of intent to deceive may have hampered the diagnosticity of the reaction time-based CIT.

Routine maintenance prolongs ESP time between failures

International Nuclear Information System (INIS)

Hurst, T.; Lannom, R.W.; Divine, D.L.

1992-01-01

This paper reports that routine maintenance of electric submersible motors (ESPs) significantly lengthened the mean time between motor failures (MTBF), decreased operating costs, and extended motor run life in the Sacroc Unit of the Kelly-Snyder field in West Texas. After the oil price boom of the early 1980s. rapidly eroding profit margins from producing properties caused a much stronger focus on reducing operating costs. In Sacroc, ESP operating life and repair costs became a major target of cost reduction efforts. The routine ESP maintenance program has been in place for over 3 years

Assessment of Muscle Fatigue Associated with Prolonged Standing in the Workplace

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Omar, Abdul Rahman; Saman, Alias Mohd; Othman, Ibrahim

2012-01-01

Objectives The objectives of this study were to determine the psychological fatigue and analyze muscle activity of production workers who are performing processes jobs while standing for prolonged time periods. Methods The psychological fatigue experienced by the workers was obtained through questionnaire surveys. Meanwhile, muscle activity has been analyzed using surface electromyography (sEMG) measurement. Lower extremities muscles include: erector spinae, tibialis anterior, and gastrocnemius were concurrently measured for more than five hours of standing. Twenty male production workers in a metal stamping company participated as subjects in this study. The subjects were required to undergo questionnaire surveys and sEMG measurement. Results Results of the questionnaire surveys found that all subjects experienced psychological fatigue due to prolonged standing jobs. Similarly, muscle fatigue has been identified through sEMG measurement. Based on the non-parametric statistical test using the Spearman's rank order correlation, the left erector spinae obtained a moderate positive correlation and statistically significant (rs = 0.552, p fatigue and to muscle fatigue among the production workers. PMID:22953228

Real-Time Polymerase Chain Reaction: Applications in Diagnostic Microbiology

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Kordo B. A. Saeed

2013-11-01

Full Text Available The polymerase chain reaction (PCR has revolutionized the detection of DNA and RNA. Real-Time PCR (RT-PCR is becoming the gold standard test for accurate, sensitive and fast diagnosis for a large range of infectious agents. Benefits of this procedure over conventional methods for measuring RNA include its sensitivity, high throughout and quantification. RT-PCR assays have advanced the diagnostic abilities of clinical laboratories particularly microbiology and infectious diseases. In this review we would like to briefly discuss RT-PCR in diagnostic microbiology laboratory, beginning with a general introduction to RT-PCR and its principles, setting up an RT PCR, including multiplex systems and the avoidance and remediation of contamination issues. A segment of the review would be devoted to the application of RT-PCR in clinical practice concentrating on its role in the diagnosis and treatment of infectious diseases.

Prolonged fasting of children before anaesthesia is common in private practice.

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Buller, Y; Sims, C

2016-01-01

Fasting guidelines for children are well established. Despite these guidelines, previous studies have shown children are often fasted for prolonged periods before anaesthesia, potentially causing discomfort and distress. Moreover, recent publications indicate shorter fasting times for oral clear fluids in children may be safe. We audited fasting times of children having elective surgery at a local large private hospital that provides care for both adults and children. We gave feedback and education to our caregivers, then repeated the audit. Data were collected from 307 children (age 6.0 ± 4.1 years) in an initial eight-week audit, and from 153 children (age 6.7 ± 4.5 years) in a follow-up four-week audit. We found fasting durations were excessive in many children. Sixty-two percent of children in each audit fasted longer than four hours for clear fluids. Children on morning lists fasted longer than children on afternoon lists. Fasting from solids was also excessively long. In the initial audit, 30% fasted more than 12 hours for solids, including 18 who last ate more than 16 hours before surgery. Data from the follow-up audit were similar. We conclude that fasting of children at our hospital is excessive, despite our efforts to shorten the duration. We suspect that our hospital is not the only one with a high incidence of prolonged fasting for children and suggest possible solutions.

Detecting drug-induced prolongation of the QRS complex: New insights for cardiac safety assessment

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Cros, C., E-mail: caroline.cros@hotmail.co.uk [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Skinner, M., E-mail: Matthew.Skinner@astrazeneca.com [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Moors, J. [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Lainee, P. [Sanofi-Aventis R and D, 371, rue du Pr Joseph Blayac, 34184 Montpellier Cedex 04 (France); Valentin, J.P. [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom)

2012-12-01

Background: Drugs slowing the conduction of the cardiac action potential and prolonging QRS complex duration by blocking the sodium current (I{sub Na}) may carry pro-arrhythmic risks. Due to the frequency-dependent block of I{sub Na}, this study assesses whether activity-related spontaneous increases in heart rate (HR) occurring during standard dog telemetry studies can be used to optimise the detection of class I antiarrhythmic-induced QRS prolongation. Methods: Telemetered dogs were orally dosed with quinidine (class Ia), mexiletine (class Ib) or flecainide (class Ic). QRS duration was determined standardly (5 beats averaged at rest) but also prior to and at the plateau of each acute increase in HR (3 beats averaged at steady state), and averaged over 1 h period from 1 h pre-dose to 5 h post-dose. Results: Compared to time-matched vehicle, at rest, only quinidine and flecainide induced increases in QRS duration (E{sub max} 13% and 20% respectively, P < 0.01–0.001) whereas mexiletine had no effect. Importantly, the increase in QRS duration was enhanced at peak HR with an additional effect of + 0.7 ± 0.5 ms (quinidine, NS), + 1.8 ± 0.8 ms (mexiletine, P < 0.05) and + 2.8 ± 0.8 ms (flecainide, P < 0.01) (calculated as QRS at basal HR-QRS at high HR). Conclusion: Electrocardiogram recordings during elevated HR, not considered during routine analysis optimised for detecting QT prolongation, can be used to sensitise the detection of QRS prolongation. This could prove useful when borderline QRS effects are detected. Analysing during acute increases in HR could also be useful for detecting drug-induced effects on other aspects of cardiac function. -- Highlights: ► We aimed to improve detection of drug-induced QRS prolongation in safety screening. ► We used telemetered dogs to test class I antiarrhythmics at low and high heart rate. ► At low heart rate only quinidine and flecainide induced an increase in QRS duration. ► At high heart rate the effects of two

Detecting drug-induced prolongation of the QRS complex: New insights for cardiac safety assessment

International Nuclear Information System (INIS)

Cros, C.; Skinner, M.; Moors, J.; Lainee, P.; Valentin, J.P.

2012-01-01

Background: Drugs slowing the conduction of the cardiac action potential and prolonging QRS complex duration by blocking the sodium current (I Na ) may carry pro-arrhythmic risks. Due to the frequency-dependent block of I Na , this study assesses whether activity-related spontaneous increases in heart rate (HR) occurring during standard dog telemetry studies can be used to optimise the detection of class I antiarrhythmic-induced QRS prolongation. Methods: Telemetered dogs were orally dosed with quinidine (class Ia), mexiletine (class Ib) or flecainide (class Ic). QRS duration was determined standardly (5 beats averaged at rest) but also prior to and at the plateau of each acute increase in HR (3 beats averaged at steady state), and averaged over 1 h period from 1 h pre-dose to 5 h post-dose. Results: Compared to time-matched vehicle, at rest, only quinidine and flecainide induced increases in QRS duration (E max 13% and 20% respectively, P < 0.01–0.001) whereas mexiletine had no effect. Importantly, the increase in QRS duration was enhanced at peak HR with an additional effect of + 0.7 ± 0.5 ms (quinidine, NS), + 1.8 ± 0.8 ms (mexiletine, P < 0.05) and + 2.8 ± 0.8 ms (flecainide, P < 0.01) (calculated as QRS at basal HR-QRS at high HR). Conclusion: Electrocardiogram recordings during elevated HR, not considered during routine analysis optimised for detecting QT prolongation, can be used to sensitise the detection of QRS prolongation. This could prove useful when borderline QRS effects are detected. Analysing during acute increases in HR could also be useful for detecting drug-induced effects on other aspects of cardiac function. -- Highlights: ► We aimed to improve detection of drug-induced QRS prolongation in safety screening. ► We used telemetered dogs to test class I antiarrhythmics at low and high heart rate. ► At low heart rate only quinidine and flecainide induced an increase in QRS duration. ► At high heart rate the effects of two out of three

Dissociation between mental fatigue and motivational state during prolonged mental activity.

Science.gov (United States)

Gergelyfi, Mónika; Jacob, Benvenuto; Olivier, Etienne; Zénon, Alexandre

2015-01-01

Mental fatigue (MF) is commonly observed following prolonged cognitive activity and can have major repercussions on the daily life of patients as well as healthy individuals. Despite its important impact, the cognitive processes involved in MF remain largely unknown. An influential hypothesis states that MF does not arise from a disruption of overused neural processes but, rather, is caused by a progressive decrease in motivation-related task engagement. Here, to test this hypothesis, we measured various neural, autonomic, psychometric and behavioral signatures of MF and motivation (EEG, ECG, pupil size, eye blinks, Skin conductance responses (SCRs), questionnaires and performance in a working memory (WM) task) in healthy volunteers, while MF was induced by Sudoku tasks performed for 120 min. Moreover extrinsic motivation was manipulated by using different levels of monetary reward. We found that, during the course of the experiment, the participants' subjective feeling of fatigue increased and their performance worsened while their blink rate and heart rate variability (HRV) increased. Conversely, reward-induced EEG, pupillometric and skin conductance signal changes, regarded as indicators of task engagement, remained constant during the experiment, and failed to correlate with the indices of MF. In addition, MF did not affect a simple reaction time task, despite the strong influence of extrinsic motivation on this task. Finally, alterations of the motivational state through monetary incentives failed to compensate the effects of MF. These findings indicate that MF in healthy subjects is not caused by an alteration of task engagement but is likely to be the consequence of a decrease in the efficiency, or availability, of cognitive resources.

Dissociation between mental fatigue and motivational state during prolonged mental activity

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Monika eGergelyfi

2015-07-01

Full Text Available Mental fatigue (MF is commonly observed following prolonged cognitive activity and can have major repercussions on the daily life of patients as well as healthy individuals. Despite its important impact, the cognitive processes involved in MF remain largely unknown. An influential hypothesis states that MF does not arise from a disruption of overused neural processes but, rather, is caused by a progressive decrease in motivation-related task engagement.Here, to test this hypothesis, we measured various neural, autonomic, psychometric and behavioral signatures of MF and motivation (EEG, ECG, pupil size, eye blinks, skin conductance responses, questionnaires and performance in a working memory task in healthy volunteers, while MF was induced by Sudoku tasks performed for 120 minutes. Moreover extrinsic motivation was manipulated by using different levels of monetary reward. We found that, during the course of the experiment, the participants’ subjective feeling of fatigue increased and their performance worsened while their blink rate and heart rate variability increased. Conversely, reward-induced EEG, pupillometric and skin conductance signal changes, regarded as indicators of task engagement, remained constant during the experiment, and failed to correlate with the indices of MF. In addition, MF did not affect a simple reaction time task, despite the strong influence of extrinsic motivation on this task. Finally, alterations of the motivational state through monetary incentives failed to compensate the effects of MF. These findings indicate that MF in healthy subjects is not caused by an alteration of task engagement but is likely to be the consequence of a decrease in the efficiency, or availability, of cognitive resources.

Characteristics of Prolonged Concussion Recovery in a Pediatric Subspecialty Referral Population

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Corwin, Daniel J.; Zonfrillo, Mark R.; Master, Christina L.; Arbogast, Kristy B.; Grady, Matthew F.; Robinson, Roni L.; Goodman, Arlene M.; Wiebe, Douglas J.

2014-01-01

Objective To identify pre-existing characteristics associated with prolonged recovery from concussion in a sample of patients referred to a pediatric sports medicine clinic. Study design This was a retrospective, exploratory cohort study of 247 patients age 5-18 years old with concussion referred to a tertiary pediatric hospital-affiliated sports medicine clinic from July 1, 2010, through December 31, 2011. A random sample of all eligible patient visits (3740) was chosen for further review and abstraction. Statistical comparisons between subsets of patients were conducted using exact chi-square tests, logistic regression, quantile regression, and Kaplan Meier survival curves. Results The median time until returning to school part-time was 12 days (interquartile range (IQR) 6-21); until returning to school full-time without accommodations was 35 days (IQR 11-105); until becoming symptom-free was 64 days (IQR 18-119); and until being fully cleared to return to sports was 75 days (IQR 30-153). 73% of all patients were symptomatic for >4 weeks, 73% were prescribed some form of school accommodation, and 61% reported a decline in grades. Characteristics associated with a prolonged recovery included a history of depression or anxiety; an initial complaint of dizziness; abnormal convergence or symptom provocation following oculomotor examination on physical examination; and history of prior concussion. Conclusion Pediatric and adolescent patients with concussion may experience cognitive and emotional morbidity that can last for several months following injury. Clinicians should consider specific pre-existing characteristics and presenting symptoms that may be associated with a more complicated recovery for concussion patients. PMID:25262302

Is prolonged cold ischemia a contraindication to using kidneys from acute kidney injury donors?

Science.gov (United States)

Orlando, Giuseppe; Khan, Muhammad A; El-Hennawy, Hany; Farney, Alan C; Rogers, Jeffrey; Reeves-Daniel, Amber; Gautreaux, Michael D; Doares, William; Kaczmorski, Scott; Stratta, Robert J

2018-03-01

To determine the impact of prolonged cold ischemia time (CIT) on the outcome of acute kidney injury (AKI) renal grafts, we therefore performed a single-center retrospective analysis in adult patients receiving kidney transplantation (KT) from AKI donors. Outcomes were stratified according to duration of CIT. A total of 118 patients receiving AKI grafts were enrolled. Based on CIT, patients were stratified as follows: (i) 20 hours (P = NS). In the nine patients with CIT >40 hours, the 4-year DCGS rate was 100%. We conclude that prolonged CIT in AKI grafts may not adversely influence outcomes and so discard of AKI kidneys because of projected long CIT is not warranted when donors are wisely triaged. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

MRI findings of prolonged post-traumatic sternal pain

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Grosse, Alexandra; Grosse, Claudia; Anderson, Suzanne [University Hospital of Berne, Department of Diagnostic, Pediatric and Interventional Radiology, Berne (Switzerland); Steinbach, Lynne [University of California San Francisco, Department of Radiology, San Francisco, CA (United States)

2007-05-15

The objective of this study was to characterize the different causes of prolonged sternal pain following thoracic trauma with involvement of the sternum and to define criteria for sternal nonunion diagnosis using MRI. Five patients with abnormalities of the sternum were evaluated for prolonged sternal pain following thoracic trauma using MRI. MR images were evaluated by two radiologists in consensus. The patients were selected from the radiology database, which included 8 patients with post-traumatic prolonged sternal pain. Two patients (n = 2) revealed a sternal nonunion after sternal fracture. One patient had a sternal fracture with delayed union and minor displacement of the sternal halves. Abnormal signal intensity alterations adjacent to and within the manubrio-sternal joint were evident in 2 patients and considered due to trauma-related changes in the manubrio-sternal joint. The 3 patients who were not included in the study had no abnormalities of the sternum: 1 of them proved to have a well-healed sternal fracture and nonunion of a rib fracture, 1 had subtle Tietze's syndrome, and 1 patient revealed no pathological findings on imaging. Various factors may be responsible for prolonged sternal pain following thoracic trauma, and these can be viewed with MRI. In cases of sternal nonunion there was common fluid-like signal in the fracture interspace between the bony edges, and the bone marrow adjacent to the nonunion showed altered signal intensity. MRI identified sternal nonunion and other trauma-related abnormalities of the sternum following chest trauma. (orig.)

The incidence of hyponatremia during prolonged ultraendurance exercise.

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Noakes, T D; Norman, R J; Buck, R H; Godlonton, J; Stevenson, K; Pittaway, D

1990-04-01

Recent studies have shown that potentially fatal hyponatremia can develop during prolonged exercise. To determine the incidence of hyponatremia in athletes competing in ultradistance events, we measured serum sodium levels in 315 of 626 (50%) runners who were treated for collapse after two 90 km ultramarathon footraces (total starters 20,335; total finishers 18,031) and in 101 of 147 (69%) finishers in a 186 km ultratriathlon. In both races the athletes drank fluids with low sodium chloride content (less than 6.8 mmol.l-1). Hyponatremia (serum sodium level less than 130 mmol.l-1) was identified in 27 of 315 (9%) collapsed runners in the 90 km races and in none of the triathletes. In response to diuretic therapy, the runner with the most severe hyponatremia (serum sodium level = 112 mmol.l-1) excreted in excess of 7.5 l dilute urine during the first 17 h of hospitalization. These data suggest that, although symptomatic hyponatremia occurs in less than 0.3% of competitors during prolonged exercise even when they ingest little sodium chloride, it is found in a significant proportion (9%) of collapsed runners. A regulated contraction of the extracellular fluid volume would explain why the majority of athletes maintain normal serum sodium levels even though they develop a significant sodium chloride deficit during prolonged exercise. Alternatively, sodium chloride losses during prolonged exercise may be substantially less than are currently believed. Physicians treating collapsed ultradistance athletes need to be aware that as many as 10% or more of such patients may be hyponatremic.

Difficult OptEase Filter Retrievals After Prolonged Indwelling Times

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Van Ha, Thuong G., E-mail: tgvanha@radiology.bsd.uchicago.edu; Kang, Lisa; Lorenz, Jonathan; Zangan, Steven; Navuluri, Rakesh; Straus, Christopher; Funaki, Brian [University of Chicago, Section of Interventional Radiology, Department of Radiology (United States)

2013-08-01

PurposeThe OptEase vena cave filter (Cordis, Piscataway, NJ) is commercially available as a retrievable or permanent filter with short recommended indwelling time, presumably due to extensive contact of the filter side struts with the inferior vena cava wall and subsequent neointimal hyperplasia leading to incorporation. Our purpose was to evaluate OptEase filter retrievals with a long indwelling time period that required unconventional retrieval techniques.Materials and MethodsWe retrospectively reviewed patients who underwent OptEase filter retrieval with long undwelling times requiring additional maneuvers for retrieval. Techniques used included rigid endobronchial forceps dissection and wire-through-loop snare. Each patient underwent postretrieval venogram to evaluate for possible complications. In addition, patients had clinical follow-up 2 weeks after the retrieval procedure.ResultsThere were three patients (2 women, 1 man; average age 64 years) who underwent OptEase filter retrieval. The mean indwelling time was 6.4 months. The indwelling filters were successfully retrieved. There were no complications. Postprocedural follow-up showed no clinical pathology.ConclusionUnconventional techniques aided in the retrieval of OptEase filters with long indwelling times.

Difficult OptEase Filter Retrievals After Prolonged Indwelling Times

International Nuclear Information System (INIS)

Van Ha, Thuong G.; Kang, Lisa; Lorenz, Jonathan; Zangan, Steven; Navuluri, Rakesh; Straus, Christopher; Funaki, Brian

2013-01-01

PurposeThe OptEase vena cave filter (Cordis, Piscataway, NJ) is commercially available as a retrievable or permanent filter with short recommended indwelling time, presumably due to extensive contact of the filter side struts with the inferior vena cava wall and subsequent neointimal hyperplasia leading to incorporation. Our purpose was to evaluate OptEase filter retrievals with a long indwelling time period that required unconventional retrieval techniques.Materials and MethodsWe retrospectively reviewed patients who underwent OptEase filter retrieval with long undwelling times requiring additional maneuvers for retrieval. Techniques used included rigid endobronchial forceps dissection and wire-through-loop snare. Each patient underwent postretrieval venogram to evaluate for possible complications. In addition, patients had clinical follow-up 2 weeks after the retrieval procedure.ResultsThere were three patients (2 women, 1 man; average age 64 years) who underwent OptEase filter retrieval. The mean indwelling time was 6.4 months. The indwelling filters were successfully retrieved. There were no complications. Postprocedural follow-up showed no clinical pathology.ConclusionUnconventional techniques aided in the retrieval of OptEase filters with long indwelling times

EFFECT OF TIME AND TEMPERATURE ON ISOMERIZATION REACTION OF ?-PINENEUSING CATALYST ZR 4+ Nanik Wijayati, Supartono, Nuni Widiarti, Tri Handayani /NATURAL ZEOLITE

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Nanik Wijayati

2016-03-01

Full Text Available Effects of time and temperature on ?-pinene isomerization reaction using catalysts Zr/natural zeolitewas studied. Characterization of the catalysts include: crystallinity, observed using X-Ray Diffraction, count Zr 4+ carried observed using X-Ray Fluorescence, area and porosity catalyst was observed using the Surface Area Analyzer, and acidity catalyst observed through gravimetric method. Isomerization reaction carried out in a batch reactor with temperature variations 90, 120 and 150 C and reaction time variations of 60, 90, 120, 150 and 180 minutes. Best results of isomerisation in this study was obtained at 150 derajat C with a reaction time of 180 minutes. Kindsof isomer obtained was observed using GCMS. Catalyst characterization results indicate that modification of the catalyst by cation Zr increases the acidity from 2.76 to 6.64 mmol/g and does not damage the crystal structure significantly. The highest product conversion in this research is 9.24%, less than the maximum results caused by pre-treatment of the catalyst produces a low area. Thus, temperature and reaction time affect the concentration of ? pinene isomerization product in addition to the effect of the catalyst used.

Development of a test for recording both visual and auditory reaction times, potentially useful for future studies in patients on opioids therapy.

Science.gov (United States)

Miceli, Luca; Bednarova, Rym; Rizzardo, Alessandro; Samogin, Valentina; Della Rocca, Giorgio

2015-01-01

Italian Road Law limits driving while undergoing treatment with certain kinds of medication. Here, we report the results of a test, run as a smartphone application (app), assessing auditory and visual reflexes in a sample of 300 drivers. The scope of the test is to provide both the police force and medication-taking drivers with a tool that can evaluate the individual's capacity to drive safely. The test is run as an app for Apple iOS and Android mobile operating systems and facilitates four different reaction times to be assessed: simple visual and auditory reaction times and complex visual and auditory reaction times. Reference deciles were created for the test results obtained from a sample of 300 Italian subjects. Results lying within the first three deciles were considered as incompatible with safe driving capabilities. Performance is both age-related (r>0.5) and sex-related (female reaction times were significantly slower than those recorded for male subjects, Psafely.

Finding the optimal dose of vitamin K1 to treat vitamin K deficiency and to avoid anaphylactoid reactions.

Science.gov (United States)

Mi, Yan-Ni; Ping, Na-Na; Li, Bo; Xiao, Xue; Zhu, Yan-Bing; Cao, Lei; Ren, Jian-Kang; Cao, Yong-Xiao

2017-10-01

Vitamin K1 injection induces severe dose-related anaphylactoid reactions and overdose for the treatment of vitamin K deficiency. We aimed to find an optimal and small dose of vitamin K1 injection to treat vitamin K deficiency and avoid anaphylactoid reactions in animal. Rats were administered a vitamin K-deficient diet and gentamicin to establish vitamin K deficiency model. Behaviour tests were performed in beagle dogs to observe anaphylactoid reactions. The results showed an increased protein induced by vitamin K absence or antagonist II (PIVKA-II) levels, a prolonging of prothrombin time (PT) and activated partial thromboplastin time (APTT) and a decrease in vitamin K-dependent coagulation factor (F) II, VII, IX and X activities in the model group. In vitamin K1 0.01 mg/kg group, the liver vitamin K1 levels increased fivefold and the liver vitamin K2 levels increased to the normal amount. Coagulation markers PT, APTT, FVII and FIX activities returned to normal. Both in the 0.1 and 1.0 mg/kg vitamin K1 groups, coagulation functions completely returned to normal. Moreover, the amount of liver vitamin K1 was 40 (0.1 mg/kg) or 100 (1.0 mg/kg) times as in normal. Vitamin K2 was about 4 (0.1 mg/kg) or 5 (1.0 mg/kg) times as the normal amount. There was no obvious anaphylactoid symptom in dogs with the dose of 0.03 mg/kg, which is equivalent to the dose of 0.01 mg/kg in rats. These results demonstrated that a small dose of vitamin K1 is effective to improve vitamin K deficiency and to prevent anaphylactoid reactions, simultaneously. © 2017 Société Française de Pharmacologie et de Thérapeutique.

The Link between Hypersensitivity Syndrome Reaction Development and Human Herpes Virus-6 Reactivation

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Joshua C. Pritchett

2012-01-01

Data Sources and Extraction. Drugs identified as causes of (i idiosyncratic reactions, (ii drug-induced hypersensitivity, drug-induced hepatotoxicity, acute liver failure, and Stevens-Johnson syndrome, and (iii human herpes virus reactivation in PubMed since 1997 have been collected and discussed. Results. Data presented in this paper show that HHV-6 reactivation is associated with more severe organ involvement and a prolonged course of disease. Conclusion. This analysis of HHV-6 reactivation associated with drug-induced severe cutaneous reactions and hepatotoxicity will aid in causality assessment and clinical diagnosis of possible life-threatening events and will provide a basis for further patient characterization and therapy.

Monitoring of need for recovery and prolonged fatigue within the working population: Evaluation of reliability and agreement over time.

Science.gov (United States)

Hoofs, H; Jansen, N W H; Jansen, M W J; Kant, I J

2017-01-01

Need for recovery (NFR) and prolonged fatigue are two important concepts for monitoring short- and long-term outcomes of psychological job demands within employees. For effective monitoring it is, however, important to gain insight in the reproducibility of the instruments that are used. The objective was to assess reproducibility of the NFR scale and Checklist Individual Strength (CIS), measuring NFR and prolonged fatigue respectively, in the working population. Longitudinal data from the Maastricht Cohort Study (MCS) study was used, capturing 12,140 employees from 45 different companies at baseline. A 'working' and 'returning to work' sample was conceived for different intervals; 4-month, 1-year, and 2-year. Reliability, assessed with the interclass correlation, was high within employees with a stable work environment for the NFR scale (0.78) and CIS (0.75). The smallest detectable change, assessing the agreement, was 41.20 for the NFR scale and 31.10 for the CIS. Reliability was satisfactory for both the NFR scale and CIS. The agreement of both scales to detect a changes within employees was, however, less optimal. It is, therefore, suggested that, ideally, both instruments are placed within a broader range of instruments to effectively monitor the outcomes of psychological job demands.

Management of children with prolonged diarrhea [version 1; referees: 3 approved

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Antonietta Giannattasio

2016-02-01

Full Text Available Prolonged diarrhea is usually defined as acute-onset diarrhea lasting 7 days or more, but less than 14 days. Its trend has been declining in recent years because of improvement in the management of acute diarrhea, which represents the ideal strategy to prevent prolonged diarrhea. The pathogenesis of prolonged diarrhea is multifactorial and essentially based on persistent mucosal damage due to specific infections or sequential infections with different pathogens, host-related factors including micronutrient and/or vitamin deficiency, undernutrition and immunodeficiency, high mucosal permeability due to previous infectious processes and nutrient deficiency with consequential malabsorption, and microbiota disruption. Infections seem to play a major role in causing prolonged diarrhea in both developing and developed areas. However, single etiologic pathogens have not been identified, and the pattern of agents varies according to settings, host risk factors, and previous use of antibiotics and other drugs. The management of prolonged diarrhea is complex. Because of the wide etiologic spectrum, diagnostic algorithms should take into consideration the age of the patient, clinical and epidemiological factors, and the nutritional status and should always include a search for enteric pathogens. Often, expensive laboratory evaluations are of little benefit in guiding therapy, and an empirical approach may be effective in the majority of cases. The presence or absence of weight loss is crucial for driving the initial management of prolonged diarrhea. If there is no weight loss, generally there is no need for further evaluation. If weight loss is present, empiric anti-infectious therapy or elimination diet may be considered once specific etiologies have been excluded.

The Oxford-Diamond In Situ Cell for studying chemical reactions using time-resolved X-ray diffraction

Science.gov (United States)

Moorhouse, Saul J.; Vranješ, Nenad; Jupe, Andrew; Drakopoulos, Michael; O'Hare, Dermot

2012-08-01

A versatile, infrared-heated, chemical reaction cell has been assembled and commissioned for the in situ study of a range of chemical syntheses using time-resolved energy-dispersive X-ray diffraction (EDXRD) on Beamline I12 at the Diamond Light Source. Specialized reactor configurations have been constructed to enable in situ EDXRD investigation of samples under non-ambient conditions. Chemical reactions can be studied using a range of sample vessels such as alumina crucibles, steel hydrothermal autoclaves, and glassy carbon tubes, at temperatures up to 1200 °C.

Development of a test for recording both visual and auditory reaction times, potentially useful for future studies in patients on opioids therapy

Directory of Open Access Journals (Sweden)

Miceli L

2015-02-01

Full Text Available Luca Miceli,1 Rym Bednarova,2 Alessandro Rizzardo,1 Valentina Samogin,1 Giorgio Della Rocca1 1Department of Anesthesia and Intensive Care Medicine, University of Udine, 2Department of Pain Medicine and Palliative Care, Hospital of Latisana, Latisana, Udine, Italy Objective: Italian Road Law limits driving while undergoing treatment with certain kinds of medication. Here, we report the results of a test, run as a smartphone application (app, assessing auditory and visual reflexes in a sample of 300 drivers. The scope of the test is to provide both the police force and medication-taking drivers with a tool that can evaluate the individual’s capacity to drive safely. Methods: The test is run as an app for Apple iOS and Android mobile operating systems and facilitates four different reaction times to be assessed: simple visual and auditory reaction times and complex visual and auditory reaction times. Reference deciles were created for the test results obtained from a sample of 300 Italian subjects. Results lying within the first three deciles were considered as incompatible with safe driving capabilities. Results: Performance is both age-related (r>0.5 and sex-related (female reaction times were significantly slower than those recorded for male subjects, P<0.05. Only 21% of the subjects were able to perform all four tests correctly. Conclusion: We developed and fine-tuned a test called Safedrive that measures visual and auditory reaction times through a smartphone mobile device; the scope of the test is two-fold: to provide a clinical tool for the assessment of the driving capacity of individuals taking pain relief medication; to promote the sense of social responsibility in drivers who are on medication and provide these individuals with a means of testing their own capacity to drive safely. Keywords: visual reaction time, auditory reaction time, opioids, Safedrive

Prolonged grieving after abortion: a descriptive study.

Science.gov (United States)

Brown, D; Elkins, T E; Larson, D B

1993-01-01

Although flawed by methodological problems, the research literature tends to provide support for the assumption that induced abortion in the 1st trimester is not accompanied by enduring negative psychological sequelae. In cases where such sequelae are reported, the morbidity is attributed to a pre-existing psychiatric condition or circumstances precipitating the choice of abortion. However, detailed descriptive letters from 45 women prepared in response to a request by a pastor of an upper-middle-class Protestant congregation in Florida indicate that prolonged grieving after abortion may be more widespread phenomenon than previously believed. Letter writers ranged in age from 25-60 years; 75% were unmarried at the time of the procedure and 29% aborted before the legalization of abortion in the US. The most frequently cited long-term sequela, especially among those who felt coerced to abort, was a continued feeling of guilt. Fantasies about the aborted fetus was the next most frequently mentioned experience. Half of the letter writers referred to their abortions, as "murder" and 44% voiced regret about their decision to abort. Other long-term effects included depression (44%), feelings of loss (31%), shame (27%), and phobic responses to infants (13%). For 42% of these women, the adverse psychological effects of abortion endured over 10 years. Since letter-writers came from a self-selected population group with a known bias against abortion and only negative experiences were solicited, these experiences must be regarded as subjectives and anecdotal. However, they draw attention to the need for methodologically sound studies of a possible prolonged grief syndrome among a small percentage of women who have abortions, especially when coercion is involved.

Reaction time inconsistency in a spatial stroop task: age-related differences through childhood and adulthood.

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Williams, Benjamin R; Strauss, Esther H; Hultsch, David F; Hunter, Michael A

2007-07-01

Age-related differences in inconsistency of reaction time (RT) across the life span were examined on a task with differing levels of demand on executive control. A total of 546 participants, aged 5 to 76 years, completed a spatial Stroop task that permitted observations under three conditions (congruent, incongruent, and neutral) according to the correspondence between the required response (based on stimulus direction) and stimulus location. An interference effect was observed across all ages. Analyses of neutral condition data replicated previous research demonstrating RT inconsistency follows a U-shaped developmental curve across the life span. The relationship between age and inconsistency, however, depended on condition: inconsistency in the congruent condition was higher than inconsistency in both the neutral and incongruent conditions across middle-aged groups. Reaction time inconsistency may reflect processing efficiency that is maximal in young adulthood and may also be sensitive to fluctuations in performance that reflect momentarily highly efficient responding.

Prolonged-release melatonin versus placebo for benzodiazepine discontinuation in patients with schizophrenia or bipolar disorder

DEFF Research Database (Denmark)

Baandrup, Lone; Lindschou, Jane; Winkel, Per

2016-01-01

OBJECTIVES: We assessed if prolonged-release melatonin can facilitate withdrawal of long-term benzodiazepine usage in patients with schizophrenia or bipolar disorder. METHODS: Randomised, placebo-controlled, blinded, parallel superiority trial of 24 weeks duration. Participants were randomised...... to prolonged-release melatonin 2 mg daily versus matching placebo and were continuously guided to gradually reduce their usual benzodiazepine dosage. The primary outcome was mean benzodiazepine daily dosage at 24 weeks. Secondary outcomes included pattern of benzodiazepine dosage over time, benzodiazepine...... cessation proportion, and benzodiazepine withdrawal symptoms. RESULTS: In total, 86 patients (21-74 years) were enrolled: 42 were randomised to melatonin versus 44 to placebo. We found no significant effect of melatonin on mean benzodiazepine dosage at 24 weeks (melatonin group 8.01 mg versus placebo group...

Time to buy or just buying time? The market reaction to bank rescue packages

OpenAIRE

Michael R King

2009-01-01

This paper reviews the market reaction to bank rescue packages announced in six countries between October 2008 and January 2009. The study distinguishes the impact on creditors as seen in the change of CDS spreads from the impact on shareholders as seen in the movement of bank stock prices. Government interventions benefited creditors at the expense of shareholders, with bank CDS spreads narrowing around the announcements in all cases. Despite a brief positive reaction, bank stock prices cont...

A transformation theory of stochastic evolution in Red Moon methodology to time evolution of chemical reaction process in the full atomistic system.

Science.gov (United States)

Suzuki, Yuichi; Nagaoka, Masataka

2017-05-28

Atomistic information of a whole chemical reaction system, e.g., instantaneous microscopic molecular structures and orientations, offers important and deeper insight into clearly understanding unknown chemical phenomena. In accordance with the progress of a number of simultaneous chemical reactions, the Red Moon method (a hybrid Monte Carlo/molecular dynamics reaction method) is capable of simulating atomistically the chemical reaction process from an initial state to the final one of complex chemical reaction systems. In the present study, we have proposed a transformation theory to interpret the chemical reaction process of the Red Moon methodology as the time evolution process in harmony with the chemical kinetics. For the demonstration of the theory, we have chosen the gas reaction system in which the reversible second-order reaction H 2 + I 2  ⇌ 2HI occurs. First, the chemical reaction process was simulated from the initial configurational arrangement containing a number of H 2 and I 2 molecules, each at 300 K, 500 K, and 700 K. To reproduce the chemical equilibrium for the system, the collision frequencies for the reactions were taken into consideration in the theoretical treatment. As a result, the calculated equilibrium concentrations [H 2 ] eq and equilibrium constants K eq at all the temperatures were in good agreement with their corresponding experimental values. Further, we applied the theoretical treatment for the time transformation to the system and have shown that the calculated half-life τ's of [H 2 ] reproduce very well the analytical ones at all the temperatures. It is, therefore, concluded that the application of the present theoretical treatment with the Red Moon method makes it possible to analyze reasonably the time evolution of complex chemical reaction systems to chemical equilibrium at the atomistic level.

The Effects of Repeated Testing, Simulated Malingering, and Traumatic Brain Injury on Visual Choice Reaction Time

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David L Woods

2015-11-01

Full Text Available Choice reaction time (CRT, the time required to discriminate and respond appropriately to different stimuli, is a basic measure of attention and processing speed. Here, we describe the reliability and clinical sensitivity of a new CRT test that presents lateralized visual stimuli and adaptively adjusts stimulus onset asynchronies (SOAs using a staircase procedure. Experiment 1 investigated the test-retest reliability in three test sessions at weekly intervals. Performance in the first test session was accurately predicted from age and computer-use regression functions obtained in a previously studied normative cohort. Central processing time (CentPT, the difference between the CRTs and simple reaction time latencies measured in a separate experiment, accounted for 55% of CRT latency and more than 50% of CRT latency variance. Performance improved significantly across the three test sessions. High intraclass correlation coefficients (ICCs were seen for CRTs (0.90, CentPTs (0.87, and an omnibus performance measure (0.81 that combined CRT and minimal SOA (mSOA z-scores. Experiment 2 investigated performance in the same participants when instructed to feign symptoms of traumatic brain injury (TBI: 87% produced abnormal omnibus z-scores. Simulated malingerers showed greater elevations in simple than choice reaction times, and hence reduced CentPTs. Latency-consistency z-scores, based on the difference between the CRTs obtained and those predicted from CentPT latencies, discriminated malingering participants from controls with high sensitivity and specificity. Experiment 3 investigated CRT test performance in military veterans who had suffered combat-related TBI and symptoms of post-traumatic stress disorder and revealed small but significant deficits in performance. The results indicate that the new CRT test shows high test-retest reliability, can assist in detecting participants performing with suboptimal effort, and is sensitive to the effects of

Age-related differences in the neural correlates of trial-to-trial variations of reaction time

Directory of Open Access Journals (Sweden)

Nancy E. Adleman

2016-06-01

Full Text Available Intra-subject variation in reaction time (ISVRT is a developmentally-important phenomenon that decreases from childhood through young adulthood in parallel with the development of executive functions and networks. Prior work has shown a significant association between trial-by-trial variations in reaction time (RT and trial-by-trial variations in brain activity as measured by the blood-oxygenated level-dependent (BOLD response in functional magnetic resonance imaging (fMRI studies. It remains unclear, however, whether such “RT-BOLD” relationships vary with age. Here, we determined whether such trial-by-trial relationships vary with age in a cross-sectional design. We observed an association between age and RT-BOLD relationships in 11 clusters located in visual/occipital regions, frontal and parietal association cortex, precentral/postcentral gyrus, and thalamus. Some of these relationships were negative, reflecting increased BOLD associated with decreased RT, manifesting around the time of stimulus presentation and positive several seconds later. Critically for present purposes, all RT-BOLD relationships increased with age. Thus, RT-BOLD relationships may reflect robust, measurable changes in the brain-behavior relationship across development.

Examining the stability of dual-task posture and reaction time measures in older adults over five sessions: a pilot study.