bluuebunny/crossref_metadata_2025_split huggingface dataset:
Psychometric properties of the Arabic version of Quality of Life Index
Authors: Halabi Jehad O. 
Published: August 2006

Aim. This paper reports a study to translate the English language version of the Quality of Life Index into Arabic and estimate its reliability and content validity.Background. Quality of life has become an important concern in health care and social policy. It is a difficult construct to define and measure, as it is determined by cultural, ethical, personal and religious values. The generic Ferrans and Powers Quality of Life Index was developed to measure quality of life of healthy individuals. Specific versions of the index were developed for particular diseases, such as diabetes, cancer and end‐stage kidney disease. The instruments were initially developed for English‐speaking clients and were later translated into several languages and used within a variety of cultures. However, there were no Arabic versions of the tool available to measure the quality of life of general populations or of people with particular diseases.Method. The Quality of Life Index was translated into Arabic using two of the techniques suggested in the literature for translation – back translation and bilingual technique. The same process was followed in the translation of the original scale and various disease‐specific versions of the instrument. The work took place between 1995 and 2004.Findings. The translated Arabic Quality of Life Index demonstrated a high degree of accuracy of translation and estimates of content validity. Subsequent to the translation of the original scale into Arabic, 13 disease‐related versions of the instrument were translated and are ready for use with clients who speak Arabic. Four of the versions have been used to collect data from clients. The results revealed high estimates of reliability for the generic, diabetes, cancer and dialysis versions.Conclusion. The Arabic version of the Quality of Life Index is highly reliable and has sufficient content validity for measuring quality of life of Arabic‐speaking clients.
Learning‐dependent changes in sleep spindles and Stage 2 sleep
Authors: FOGEL STUART M. , SMITH CARLYLE T. 
Published: August 2006

SummaryIt has become increasingly clear that sleep is necessary for efficient memory consolidation. Recently, it has been found that Stage 2 sleep disruption impairs procedural memory performance, and that memory performance is correlated with the duration of Stage 2 sleep; but the mechanisms involved in synaptic plasticity for procedural memory during sleep have not been identified. The present study examined the learning‐dependent changes in sleep, including Stage 2 sleep spindles. Following an intense period of simple motor procedural learning, the duration of Stage 2 sleep and spindle density increased. There were no changes observed in the duration of any other stage of sleep or in the density of rapid eye movements. These findings support the hypothesis that sleep spindles are involved in the off‐line reprocessing of simple motor procedural memory during Stage 2 sleep.
Duration of sleep and breast cancer risk in a large population‐based case–control study
Authors: McELROY JANE A. , NEWCOMB POLLY A. , TITUS‐ERNSTOFF LINDA , TRENTHAM‐DIETZ AMY , HAMPTON JOHN M. , EGAN KATHLEEN M. 
Published: August 2006

SummaryOne important function of sleep may be its contribution to the maintenance of the immune system and regulation of the circadian rhythms by melatonin. Researchers have speculated that disruption of immune functions involving cortisol levels and natural killer cell activity may increase breast cancer risk whereas increased melatonin exposure may protect against breast cancer. We conducted a multistate population‐based case–control study of 4033 women with invasive breast cancer and 5314 community women without breast cancer in which we inquired about women's sleep habits in the recent past and during adult lifetime. Relative to women who slept 7.0–7.9 h/night, the multivariate odds ratio for developing breast cancer among women who slept an average of 9 h or more per night approximately 2 years prior to interview was 1.13 (95% CI 0.93–1.37). The multivariate‐adjusted odds ratio for the continuous term was 1.06 (95% CI 1.01–1.11), suggesting a 6% increase in risk for every additional hour of sleep. Similar patterns were observed for average lifetime adult sleep duration. We found little evidence that sleeping few hours per night was associated with breast cancer risk. The results of this study suggest that increasing sleep duration is modestly associated with an increased breast cancer risk. In contrast, short duration of sleep (<7 h/night) is not substantially associated with increased risk. Further research in this area is warranted.
Dry mouth upon awakening in obstructive sleep apnea
Authors: OKSENBERG ARIE , FROOM PAUL , MELAMED SAMUEL 
Published: August 2006

SummaryThe aim was to assess the significance of dry mouth upon awakening as a symptom of obstructive sleep apnea (OSA). The participants were 668 consecutive adults referred for polysomnographic evaluation (PSG) because of snoring and suspected OSA, and 582 adults who were attending a general health check‐up. Data were obtained from self‐administered questionnaires and PSG evaluation. The participants were asked to answer the following question: ‘During the last month, did you experience waking up in the morning with a dry mouth?’. The response scale consisted of five categories: ‘never’, ‘rarely’, ‘sometimes’, often’, or ‘almost always’. We classified patients as having dry mouth upon awakening complaint only if they reported experiencing the symptom ‘almost always’. The prevalence of dry mouth upon awakening was twofold higher in patients with OSA (31.4%) than in primary snorers (16.4%, P < 0.001), and increased linearly from 22.4%, to 34.5%, and 40.7% in mild, moderate, and severe OSA respectively (P < 0.001). The prevalence of dry mouth upon awakening in the control group was 3.2%. Logistic regression results indicated that this symptom significantly differentiated OSA patients from primary snorers after adjusting for age, BMI, gender, hypertension, and other classical OSA symptoms (OR 2.33, 95% CI 1.34–4.07). Dry mouth upon awakening appears as a significant symptom of OSA. We suggest that increased sleep time spent with an open mouth is a likely explanation for these findings.
What predicts patients’ perceptions of improvement in insomnia?
Authors: VINCENT NORAH , PENNER STEPHANIE , LEWYCKY SAMANTHA 
Published: August 2006

SummaryAlthough there has been considerable research into the effectiveness of individual cognitive behavioral treatment for chronic insomnia, less is known about patients’ perceptions of what constitutes actual improvement. This study utilized 70 outpatients (mean age = 49.7 years, SD = 12.0) with insomnia who completed a 6‐week cognitive behavioral group for sleep. Participants completed a number of primary (Pittsburgh Sleep Quality Index) and secondary measures (the Dysfunctional Beliefs about Sleep Scale, Insomnia Severity Index, Beck Depression Inventory, Penn State Worry Questionnaire) at pre‐ and post‐treatment. Perceived improvement was measured using the Clinical Global Improvement Scale (CGI). Results were analyzed using a combination of Logistic Regression analysis and receiver operating curve characteristic analysis (ROC). Results demonstrated that sleep quality and sleep duration were the most sensitive primary measures, or best predicted perceived improvement, whereas sleep efficiency was the most specific primary measure, or best predicted perceived lack of improvement (defined as only mild improvement). Of the secondary measures, results showed that daytime impairment was the most sensitive predictor of perceived improvement and that mood was the most specific predictor of perceived lack of improvement. Implications of these findings are that sleep quality, sleep duration, and sleep efficiency may offer different types of information and the choice of measure for predicting global improvement in insomnia will depend on the needs of the researcher/clinician.
Epidemiological aspects of self‐reported sleep onset latency in Japanese junior high school children
Authors: ALEXANDRU GAINA , MICHIKAZU SEKINE , SHIMAKO HAMANISHI , XIAOLI CHEN , HITOMI KANAYAMA , TAKASHI YAMAGAMI , ROBERT WILLIAMS W. , SADANOBU KAGAMIMORI 
Published: August 2006

SummaryThe purpose of this study was to investigate the relationships between sleep onset latency (SOL) and other sleep–wake patterns and media use habits in Japanese schoolchildren. A total of 9718 junior high school children responded (12.8 years) and 9199 questionnaires were used in the present analyses. The questionnaire assessed sleep–wake patterns, TV viewing and videogame habits. Overall, 72.1% of the subjects reported short SOL (≤20 min). Long SOL subjects (>20 min) were strongly associated with disturbed sleep manifested especially by increased risk of night awakenings, decreased sleep depth, and bad sleep in general (overall sleep quality). Prolonged SOL was also associated with daytime sleepiness, difficulties in falling asleep, bad morning feeling and sleep insufficiency. We found a U‐shaped relationship between sleep period and SOL. Increase in bedtime was accompanied by increased risk of prolonged SOL. The impact of ultra‐short and ultra‐long SOL (≤5 and ≥40 min) was also analysed. Long durations of watching television and playing videogame were significantly associated with prolonged SOL. After adjustment for sex, girls presented significantly higher risk of prolonged SOL. Body mass index adjustment did not reveal any significant results. SOL presents a significant component of sleep–wake habits; poor sleep hygiene and insufficient sleep time significantly increase SOL. Parents, healthcare practitioners and children themselves should be aware of the potentially negative influence of prolonged SOL. Additionally, the optimal coherent sleep–wake schedule must be promoted in parallel with the limitation on the viewing TV and game practices.
Sleep in healthy seniors: a diary study of the relation between bedtime and the amount of sleep obtained
Authors: MONK TIMOTHY H. , THOMPSON WESLEY K. , BUYSSE DANIEL J. , HALL MARTICA , NOFZINGER ERIC A. , REYNOLDS CHARLES F. 
Published: August 2006

SummaryThe aim of this study was to determine whether naturally occurring inter‐individual and intra‐individual differences in bedtime selection in the elderly might be lawfully related to the amount of sleep that is obtained. A total of 128 seniors (63f, 65m) aged 70–92 years each provided a week of sleep diary data yielding a total of 896 subject‐nights for analysis. From each subject‐night the diary was used to derive measures of time in bed (TIB) and total sleep time (TST). These measures were used as dependent variables in mixed‐effect linear models (nights nested within subjects) with the independent variable being bedtime for that subject‐night, arbitrarily expressed as minutes since 19:00 hours. Although there were strong inter‐individual and intra‐individual differences, for both genders, bedtime had a statistically significant effect (P < 0.001) on both TIB and TST. We observed that later bedtimes were associated with less time in bed and less time asleep. On average between 7 and 8 min of less TIB and TST were associated with each 10‐min delay in bedtime from 19:00 hours. These results are interpreted in terms of increases in sleep being derived from living in a better harmony with an earlier peaking circadian pacemaker characteristic of older age, although other possible mechanisms are also considered (e.g. age‐dependent alterations in phase angle and homeostatic sleep need).
Effects of two nights sleep deprivation and two nights recovery sleep on response inhibition
Authors: DRUMMOND SEAN P. A. , PAULUS MARTIN P. , TAPERT SUSAN F. 
Published: August 2006

SummaryThis study examined the effects of two nights of total sleep deprivation (TSD) and two nights of recovery sleep on response inhibition. Thirty‐eight young, healthy adults performed a Go‐NoGo task at 14 : 00 after: (1) a normal night of sleep; (2) each of two consecutive nights of TSD; and (3) each of two consecutive nights of recovery sleep; they also performed the task at 05 : 00 during the first night of sleep deprivation. We hypothesized that TSD would lead to an impaired ability to withhold a response that would be reversed with recovery sleep. Subjects did experience a significant increase in false positive responses throughout all of TSD, errors of omission (i.e. missed ‘go’ targets) were not significant until after the second night of TSD. Both components (withholding a response and automatic responding) of the task returned to baseline levels after one night of recovery sleep. These data suggest that individuals experience difficulty in withholding an inappropriate response during TSD, even when they are able to attend to the incoming stimuli and respond accurately to appropriate stimuli.
Sleep bruxism is associated to micro‐arousals and an increase in cardiac sympathetic activity
Authors: HUYNH N. , KATO T. , ROMPRÉ P. H. , OKURA K. , SABER M. , LANFRANCHI P. A. , MONTPLAISIR J. Y. , LAVIGNE G. J. 
Published: August 2006

SummarySleep bruxism (SB) subjects show a higher incidence of rhythmic masticatory muscle activity (RMMA) than control subjects. RMMA is associated with sleep micro‐arousals. This study aims to: (i) assess RMMA/SB episodes in relation to sleep cycles; (ii) establish if RMMA/SB and micro‐arousals occur in relation to the slow wave activity (SWA) dynamics; (iii) analyze the association between RMMA/SB and autonomic cardiac activity across sleep cycles. Two nights of polygraphic recordings were made in three study groups (20 subjects each): moderate to high SB, low SB and control. RMMA episodes were considered to occur in clusters when several groups of RMMA or non‐specific oromotor episodes were separated by less than 100 s. Correlations between sleep, RMMA/SB index and heart rate variability variables were assessed for the first four sleep cycles of each study group. Statistical analyses were done with SYSTAT and SPSS. It was observed that 75.8% of all RMMA/SB episodes occurred in clusters. Micro‐arousal and SB indexes were highest during sleep cycles 2 and 3 (P < 0.001). Within each cycle, micro‐arousal and RMMA/SB indexes showed an increase before each REM sleep (P ≤ 0.02). The cross‐correlation plot for micro‐arousal index showed positive association from 4 min preceding SB onset in the moderate to high SB subjects (P ≤ 0.06). The cross‐correlation plot revealed that SWA decreases following SB onset (P ≤ 0.05). Further cross‐correlation analysis revealed that a shift in sympatho‐vagal balance towards increased sympathetic activity started 8 min preceding SB onset (P ≤ 0.03). In moderate to severe SB subjects, a clear increase in sympathetic activity precedes SB onset.
Development of the Sleep Quality Scale
Authors: YI HYERYEON , SHIN KYUNGRIM , SHIN CHOL 
Published: August 2006

SummarySleep quality affects health and the overall quality of life. As the factors that influence sleep quality and their relative importance vary among individuals, a self‐report method is essential. Although various questionnaires have been used to assess sleep quality, few all‐inclusive assessment scales have been developed. Therefore, the purpose of this study was to develop an instrument for measuring sleep quality and to study its validity and reliability. A Sleep Quality Scale (SQS) was developed using item analysis and factor analysis on items with content validity. SQS, composed of 28 items and six factors, accounted for 62.6% of the total variance. The difference of SQS score between insomniacs and normal subjects confirmed the construct validity (t = −13.8, P = 0.000). Concurrent validity was identified by the significant correlation of SQS with the Pittsburgh Sleep Quality Index (r = 0.72, P = 0.000). The Cronbach's alpha coefficient was 0.92 for internal consistency and the correlation coefficient was 0.81 for test–retest reliability at a 2‐week interval. The developed SQS was therefore confirmed to be a valid and reliable instrument for the comprehensive assessment of sleep quality.
Frequent lapses of responsiveness during an extended visuomotor tracking task in non‐sleep‐deprived subjects
Authors: PEIRIS MALIK T. R. , JONES RICHARD D. , DAVIDSON PAUL R. , CARROLL GRANT J. , BONES PHILIP J. 
Published: August 2006

SummaryWe investigated the occurrence of lapses of responsiveness (lapses) in 15 non‐sleep‐deprived subjects performing a 1D continuous tracking task during normal working hours. Tracking behaviour, facial video, and electroencephalogram (EEG) were recorded simultaneously during two 1‐h sessions. Rate and duration were estimated for lapses identified by a tracking flat spot and/or video sleep. Fourteen of the 15 subjects had one or more lapses, with an overall rate of 39.3 ± 12.9 lapses per hour (mean ± SE) and a lapse duration of 3.4 ± 0.5 s. We also found that subjects’ performance improved towards the end of the 1‐h long session, even though no external temporal cues were available. Spectral power was found to be higher during lapses in the delta, theta, and alpha bands, and lower in the beta, gamma, and higher bands, but correlations between changes in EEG power and lapses were low. In conclusion, lapses are a frequent phenomenon in normal subjects – even when not sleep‐deprived – engaged in an extended monotonous continuous visuomotor task. This is of particular importance to the transport sector in which there is a need to maintain sustained attention for extended periods of time and in which lapses can lead to multiple‐fatality accidents.
Expression of ABA 8′‐hydroxylases in relation to leaf water relations and seed development in bean
Authors: Yang Seung Hwan , Zeevaart Jan A.D. 
Published: August 2006

SummaryIn plants, the level of abscisic acid (ABA) is determined by synthesis and catabolism. Hydroxylation of ABA at the 8′ position is the key step in ABA catabolism. This reaction is catalyzed by ABA 8′‐hydroxylase, a cytochrome P450 (CYP). The cDNAs of PvCYP707A1 and PvCYP707A2 were isolated from bean (Phaseolus vulgaris L.) axes treated with (+)‐ABA and that of PvCYP707A3 from dehydrated bean leaves. The recombinant PvCYP707A proteins expressed in yeast were biochemically characterized. Yeast strains over‐expressing any of the three PvCYP707As were able to convert ABA to phaseic acid (PA). The microsomal fractions from these yeast strains also exhibited ABA 8′‐hydroxylase activity. Expression of PvCYP707A3 in primary leaves was strongly increased by water stress, whereas PvCYP707A1 and PvCYP707A2 mRNA levels were rapidly increased by rehydration of water‐stressed leaves. Northern blot analysis of PvCYP707As in bean showed a high level of expression in the mature fruits, senescent leaves, roots, seed coats and axes. All three PvCYP707As were expressed at varying intensities throughout seed development. Imbibed seeds also had high PvCYP707A mRNA levels. Thus, expression of PvCYP707As is both environmentally and developmentally regulated. Transgenic Nicotiana sylvestris plants over‐expressing PvCYP707As displayed a wilty phenotype, and had reduced ABA levels and increased PA levels. These results demonstrate that expression of PvCYP707As is the major mechanism by which ABA catabolism is regulated in bean.
Visualization of PtdIns3P dynamics in living plant cells
Authors: Vermeer Joop E.M. , van Leeuwen Wessel , Tobeña‐Santamaria Rafa , Laxalt Ana M. , Jones David R. , Divecha Nullin , Gadella Theodorus W.J. , Munnik Teun 
Published: August 2006

SummaryTo investigate PtdIns3P localization and function in plants, a fluorescent PtdIns3P‐specific biosensor (YFP–2xFYVE) was created. On lipid dot blots it bound specifically and with high affinity to PtdIns3P. Transient expression in cowpea protoplasts labelled vacuolar membranes and highly motile structures undergoing fusion and fission. Stable expression in tobacco BY‐2 cells labelled similar motile structures, but labelled vacuolar membranes hardly at all. YFP–2xFYVE fluorescence strongly co‐localized with the pre‐vacuolar marker AtRABF2b, partially co‐localized with the endosomal tracer FM4‐64, but showed no overlap with the Golgi marker STtmd–CFP. Treatment of cells with wortmannin, a PI3 kinase inhibitor, caused the YFP–2xFYVE fluorescence to redistribute into the cytosol and nucleus within 15 min. BY‐2 cells expressing YFP–2xFYVE contained twice as much PtdIns3P as YFP‐transformed cells, but this had no effect on cell‐growth or stress‐induced phospholipid signalling responses. Upon treatment with wortmannin, PtdIns3P levels were reduced by approximately 40% within 15 min in both cell lines. Stable expression of YFP–2xFYVE in Arabidopsis plants labelled different subcellular structures in root compared with shoot tissues. In addition labelling the motile structures common to all cells, YFP–2xFYVE strongly labelled the vacuolar membrane in leaf epidermal and guard cells, suggesting that cell differentiation alters the distribution of PtdIns3P. In dividing BY‐2 cells, YFP–2xFYVE‐labelled vesicles surrounded the newly formed cell plate, suggesting a role for PtdIns3P in cytokinesis. Together, these data show that YFP–2xFYVE may be used as a biosensor to specifically visualize PtdIns3P in living plant cells.
The evolution of cooperation and altruism – a general framework and a classification of models
Authors: Lehmann L. , Keller L. 
Published: August 2006

AbstractOne of the enduring puzzles in biology and the social sciences is the origin and persistence of intraspecific cooperation and altruism in humans and other species. Hundreds of theoretical models have been proposed and there is much confusion about the relationship between these models. To clarify the situation, we developed a synthetic conceptual framework that delineates the conditions necessary for the evolution of altruism and cooperation. We show that at least one of the four following conditions needs to be fulfilled: direct benefits to the focal individual performing a cooperative act; direct or indirect information allowing a better than random guess about whether a given individual will behave cooperatively in repeated reciprocal interactions; preferential interactions between related individuals; and genetic correlation between genes coding for altruism and phenotypic traits that can be identified. When one or more of these conditions are met, altruism or cooperation can evolve if the cost-to-benefit ratio of altruistic and cooperative acts is greater than a threshold value. The cost-to-benefit ratio can be altered by coercion, punishment and policing which therefore act as mechanisms facilitating the evolution of altruism and cooperation. All the models proposed so far are explicitly or implicitly built on these general principles, allowing us to classify them into four general categories.
The ductile‐to‐brittle transition in steels controlled by particle cracking
Authors: ORTNER S. R. 
Published: August 2006

ABSTRACTFracture initiation sites in a number of MnMoNi steels have been assessed, leading to the development of a model describing cleavage fracture in these steels. The weak links in all the steels are iron carbides. The model finds an effective upper limit (rmax) to the carbide size distribution, apparently dependent on the final quench. Carbide cracking is strain‐controlled, and microcrack extension is stress‐controlled. Fulfillment of the criteria for particle cracking and microcrack extension leads to predictions of fracture toughness that increase with temperature and, ultimately, become infinite. The model predicts quantitatively the effects on fracture toughness of heat treatments that induce changes in segregation, in particle size distributions and flow properties. After a severe quench, the rmax criterion results in the apparent domination of fracture by a critical stress.