Association between report of insomnia and daytime functioning

ObjectivesThe relationship between reports of insomnia and daytime functioning was investigated using hierarchical regression. The presence or absence of a report of insomnia was the predictor of primary interest. A number of covariates were included in the model: demographic variables, health variables, and quantitative sleep parameters.MethodsData were collected from a community sample in the Memphis, Tennessee area. Data from 734 volunteers, ranging in age from 20 to 96 years were analyzed. The sample included 235 individuals who reported having chronic insomnia and 499 individuals who reported no sleep problems. Participants completed a 2-week sleep diary, a battery of daytime functioning questionnaires, and a medical disorders checklist. Demographic information was also collected. The daytime functioning assessment included the Beck Depression Inventory, the State-Trait Anxiety Inventory, the Epworth Sleepiness Scale, the Insomnia Impact Scale, and the Fatigue Severity Scale. The hierarchical regression model included four sets. The first three sets consisted of 18 variables capturing demographic, health, and sleep diary parameters. The fourth set included a single dichotomous variable representing the presence or absence of a report of insomnia.ResultsReports of insomnia were a significant predictor of all five daytime functioning measures, which is consistent with previous research. We also showed that reports of insomnia were able to uniquely explain a significant amount of variability in self-reported daytime functioning after controlling for demographics, health, and sleep diary variables. The pattern of individual variables that reached significance in the first three sets varied depending on which daytime functioning measure was predicted, however, age, the presence of pain, the presence of mental health problems, SOL, and WASO were the most commonly significant predictors of poor daytime functioning from these sets across measures.ConclusionsIndividuals’ perceptions of their sleep are related to differences in their reported daytime functioning, which are not accounted for by demographic factors, health surveys, or quantitative sleep assessments. Reports of insomnia may be related to a set of common cognitive factors among individuals who report having insomnia which cause them to be distressed with their sleep and increase their dissatisfaction with daytime functioning. Relevance of the findings to insomnia research and clinical management are discussed.     

Scattering Analysis of AlGaN/AlN/GaN Heterostructures with Fe-Doped GaN Buffer

The results of the study of the influence of Fe segregation into the unintentionally doped GaN channel layer in AlGaN/AlN/GaN heterostructures with Fe-doped GaN buffer layer on the electrical properties of two-dimensional electron gas are presented. A set of several samples was grown by metal-organic vapor-phase epitaxy and characterized by the van der Pauw method. The dependence of concentration and mobility of the two-dimensional electron gas on the channel layer thickness was analyzed theoretically by self-consistent solving of 1D Poisson and Schrödinger equations and scattering rate calculations within the momentum relaxation time approximation. It was found that both concentration and mobility decreases were responsible for the increase in the sheet resistance in the structures with a thinner channel layer, with a drop in mobility being not only due to ionized impurity scattering, but also due to a combined effect of weakening of screening, lower carrier energy and change in form-factors on scattering by interface roughness, dislocations and polar optical phonons.     

Application of a SF-4Spectrophotometer to a study of the passage of ultraviolet rays through animal fur

Summary This paper describes a method and the results obtained in investigations on penetration of ultraviolet light in the range 220–400 m through the fur of animals; we used a special unit incorporating a SF-4 spectrophotometer which operated with a FÉU-18 type photoelectron multiplier. A spectrophotometric study was made of samples of fur taken as biopsy specimens of freshly killed animals.(Presented by Active Member AMN SSSR A. V. Lebedinskii) Translated from Byulleten Éksperimental'noi Biologii i Meditsiny, Vol. 56, No. 9, pp. 124–126, September, 1963     

Antiherpetic activity of 5-alkynyl derivatives of 2'-deoxyuridine

A series of new 5-alkynyl-2'-deoxyuridines have been synthesized and their antiherpetic activity was tested in the cultured Vero cells on a model of herpes simplex virus type 1, including its acyclovir-resistant strains. Some test compounds were found to have a significant specific antiherpetic activity. Nucleoside XIV showed the greatest activity. Compounds IV and X also has displayed a significant activity against the herpes simplex virus type 1 strain that is highly resistant to acyclovir. Examining the combined action of substance II with acyclovir and ganciclovir has revealed a synergetic effect.