bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relation between Polarization Phenomenon and Space-Charge-Limited Currents in Rutile Single Crystals (TiO2)
Authors: Cardon F. 
Published: May 2005

A considerable depolarization current was observed in rutile single crystals. It was ascribed to electrons trapped at the positive electrode in levels which probably exist only in superficial layers of the crystal. The charge piled up corresponds to, at minimum, 1014/cm2 elementary charges e. The dependence of the depolarization current on the depolarization time, I ∼ 1/t, could be explained by assuming that the time dependence is governed by the probability of electron transitions from traps to the conduction band and these under the influence of the strong electric field of the space charge.
Assuming that there are also 1014/cm2 ionized donors at the negative electrode, the observed current-voltage characteristics in thin flakes can be explained by taking into account that this gives rise to a field of the order of 106 V/cm at the negative electrode. Electrons then can enter the crystal by field emission from the negative electrode, but the current will be space-charge-limited in the bulk of the crystal. This explains the observed I ∼ V2 dependence.
Some Properties of the Long-Time Values of the Probability Densities for Moderately Dense Gases
Authors: Piccirelli Robert A. 
Published: May 2005

It has been argued that, for sufficiently large times, the n-particle probability densities of a moderately dense, simple gas become time-independent functionals of the one-particle probability densities. Proofs are given for several properties of the power series representation of these functionals. In particular, it is shown that the equilibrium value of the n-particle functional is identical to the usual equilibrium probability density term by term, and that the corresponding generalized Boltzmann collision integral vanishes as it should. The Green-Cohen form of the functional is shown to be a formal power series solution of Bogoliubov's functional differential hierarchy. Moreover, a proof is given that the Bogoliubov and Green-Cohen forms of the functional are formally identical term by term. It is argued that the higher terms of these two series probably diverge together.
In the course of the discussion, several new properties of the coefficient operators of the power series for the functional are derived. Moreover, an integral equation for the n-particle functional is derived which may have solutions not representable as functional power series in the one-particle probability density.
Permeability and Diffusivity of Hydrogen Through a Palladium Tube
Authors: Katz O. M. , Gulbransen E. A. 
Published: May 2005

A palladium diffusion tube which supplies high purity hydrogen was constructed for use in a high vacuum glass system. Temperatures of 213–379°C and back pressures from 1 to 2 atm H2 were used. In this range the permeability was proportional to the square root of pressure and an exponential function of reciprocal temperature. The tube had a long life if it was kept above 150°C while exposed to the gas.Diffusion coefficients obtained from the permeability experiments were in very good agreement with previous results. The equation for diffusion was DHPd = 4.31×10−3e−5600/RT. The large amounts of hydrogen obtained were reproducible to ±2% of the mean.
Interactions between the solitary endoparasitoid, Meteorus gyrator (Hymenoptera: Braconidae) and its host, Lacanobia oleracea (Lepidoptera: Noctuidae), infected with the entomopathogenic microsporidium, Vairimorpha necatrix (Microspora: Microsporidia)
Authors: Down R.E. , Smethurst F. , Bell H.A. , Edwards J.P. 
Published: May 2005

AbstractInfection of Lacanobia oleracea(Linnaeus) larvae with the microsporidium Vairimorpha necatrix(Kramer) resulted in significant effects on the survival and development of the braconid parasitoid, Meteorus gyrator(Thunberg). Female M. gyrator did not show any avoidance of V. necatrix-infected hosts when they were selecting hosts for oviposition. When parasitism occurred at the same time as infection by the pathogen, or up to four days later, no significant detrimental effects on the parasitoid were observed. However, when parasitism occurred six to eight days after infection, a greater proportion(12.5–14%) of hosts died before parasitoid larvae egressed. Successful eclosion of adult wasps was also reduced. When parasitism and infection were concurrent, parasitoid larval development was significantly faster in infected hosts, and cocoons were significantly heavier. However, as the time interval between infection and parasitism increased, parasitoid larval development was significantly extended by up to two days, and the cocoons formed were significantly (c. 20%) smaller. Vairimorpha necatrix spores were ingested by the developing parasitoid larvae, accumulated in the occluded midgut, and were excreted in the meconium upon pupation.
Reliability and validity of a questionnaire to measure personal, social and environmental correlates of fruit and vegetable intake in 10–11-year-old children in five European countries
Authors: De Bourdeaudhuij I , Klepp K-I , Due P , Rodrigo C Perez , de Almeida MDV , Wind M , Krølner R , Sandvik C , Brug J 
Published: May 2005

AbstractObjectivesTo investigate the internal consistency of the scales and the test–retest reliability and predictive validity of behaviour theory-based constructs measuring personal, social and environmental correlates of fruit and vegetable intake in 10–11-year-old children.DesignTest–retest with one-week interval.SettingFive European countries: Norway, Spain, Denmark, Portugal, Belgium.SubjectsThree hundred and twenty-six children completed the questionnaire during class hours.ResultsFor the total sample across all countries, the test–retest reliability was good to very good (intra-class correlation coefficient (ICC) >0.60) for 12 out of the 15 fruit constructs and also for 12 out of the 15 vegetable constructs. Acceptable ICCs, ranging between 0.50 and 0.59, were found for the remaining constructs. Test–retest reliability was comparable across countries. Only in Portugal were some significantly lower ICCs found for some constructs (knowledge and barriers related to fruit, general self-efficacy related to fruit and vegetables) compared with the other countries. Cronbach'sαvalues were moderate to high (range 0.52 to 0.89) with the exception of the general self-efficacy scale, which had a value below 0.50 for both fruit (α= 0.42) and vegetables (α= 0.49). Spearman correlations with intake ranged between -0.16 and 0.54 for personal determinants and between 0.05 and 0.38 for environmental determinants. Compared with other studies, predictive validity can be considered moderate to good.ConclusionsThe questionnaire provides a reliable, valid and easy-to-administer tool for assessing personal, social and environmental factors of potential influence on fruit and vegetable intake in 10–11-year-olds.
Overweight in urban, low-income, African American and Hispanic children attending Los Angeles elementary schools: research stimulating action
Authors: Slusser Wendelin M , Cumberland William G , Browdy Ben L , Winham Donna M , Neumann Charlotte G 
Published: May 2005

AbstractObjectiveThis study was undertaken to establish the prevalence and severity of nutritional problems among low-income children of elementary school age in the Los Angeles Unified School District (LAUSD) in order to collect baseline data to inform policy-makers.Design and methodsA cross-sectional survey of children in 14 elementary schools was conducted from January to June, 1998. Nine hundred and nineteen children were measured and interviewed. The planning, design and data analysis were carried out in collaboration with key LAUSD policy-makers.ResultsMore than 35% of the sample was classified as being at risk for overweight or overweight according to body mass index.ConclusionThere is a high prevalence of children who are at risk for overweight or who are overweight in Los Angeles. This finding has triggered the development of multiple school-based intervention programmes.
Reproducibility of a short semi-quantitative food group questionnaire and its performance in estimating nutrient intake compared with a 7-day diet diary in the Million Women Study
Authors: Roddam Andrew W , Spencer Elizabeth , Banks Emily , Beral Valerie , Reeves Gillian , Appleby Paul , Barnes Isobel , Whiteman David C , Keyal Timothy J 
Published: May 2005

AbstractObjectivesTo assess the short- and long-term reproducibility of a short food group questionnaire, and to compare its performance for estimating nutrient intakes in comparison with a 7-day diet diary.DesignParticipants for the reproducibility study completed the food group questionnaire at two time points, up to 2 years apart. Participants for the performance study completed both the food group questionnaire and a 7-day diet diary a few months apart. Reproducibility was assessed by kappa statistics and percentage change between the two questionnaires; performance was assessed by kappa statistics, rank correlations and percentages of participants classified into the same and opposite thirds of intake.SettingA random sample of participants in the Million Women Study, a population-based prospective study in the UK.SubjectsIn total, 12 221 women aged 50–64 years.ResultsIn the reproducibility study, 75% of the food group items showed at least moderate agreement for all four time-point comparisons. Items showing fair agreement or worse tended to be those where few respondents reported eating them more than once a week, those consumed in small amounts and those relating to types of fat consumed. Compared with the diet diary, the food group questionnaire showed consistently reasonable performance for the nutrients carbohydrate, saturated fat, cholesterol, total sugars, alcohol, fibre, calcium, riboflavin, folate and vitamin C.ConclusionsThe short food group questionnaire used in this study has been shown to be reproducible over time and to perform reasonably well for the assessment of a number of dietary nutrients.
Effect of iron supplementation on mental and motor development in children: systematic review of randomised controlled trials
Authors: Sachdev HPS , Gera Tarun , Nestel Penelope 
Published: May 2005

AbstractObjectiveTo evaluate the effect of iron supplementation on mental and motor development in children through a systematic review of randomised controlled trials (RCTs).Data sourcesElectronic databases, personal files, hand search of reviews, bibliographies of books, abstracts and proceedings of international conferences.Review methodsRCTs with interventions that included oral or parenteral iron supplementation, fortified formula milk or cereals were evaluated. The outcomes studied were mental and motor development scores and various individual development tests employed, including Bayley mental and psychomotor development indices and intelligence quotient.ResultsThe pooled estimate (random effects model) of mental development score standardised mean difference (SMD) was 0.30 (95% confidence interval (CI) 0.15 to 0.46,P< 0.001;P< 0.001 for heterogeneity). Initial anaemia and iron-deficiency anaemia were significant explanatory variables for heterogeneity. The pooled estimate of Bayley Mental Development Index (weighted mean difference) in younger children (<27 months old) was 0.95 (95% CI −0.56 to 2.46,P= 0.22;P= 0.016 for heterogeneity). For intelligence quotient scores (≥8 years age), the pooled SMD was 0.41 (95% CI 0.20 to 0.62,P< 0.001;P= 0.07 for heterogeneity). There was no effect of iron supplementation on motor development score (SMD 0.09, 95% CI -0.08 to 0.26,P= 0.28;P= 0.028 for heterogeneity).ConclusionsIron supplementation improves mental development score modestly. This effect is particularly apparent for intelligence tests above 7 years of age and in initially anaemic or iron-deficient anaemic subjects. There is no convincing evidence that iron treatment has an effect on mental development in children below 27 months of age or on motor development.
The CATCH Kids Club: a pilot after-school study for improving elementary students’ nutrition and physical activity
Authors: Kelder Steve , Hoelscher Deanna M , Barroso Cristina S , Walker Joey L , Cribb Peter , Hu Shaohua 
Published: May 2005

AbstractBackgroundAlthough many school-based diet and physical activity interventions have been designed and evaluated, relatively few have been tested for the after-school setting. After-school day-care programmes at either elementary schools or private locations provide a ready-made opportunity for health programmes that may be difficult to incorporate into an already-full school day. The purpose of this paper is to report on a pilot study of an after-school adaptation of the CATCH (Coordinated Approach To Child Health) elementary school programme called the CATCH Kids Club (CKC).MethodsThe CKC was pilot-tested and formatively evaluated in 16 Texas after-school programmes: eight in El Paso and eight in Austin (four intervention and four reference sites each). Evaluation consisted of direct observation of moderate to vigorous physical activity during play time, self-reported food intake and physical activity, and focus group interviews with after-school programme staff.ResultsStudents responded well to the physical activity and snack components and were less interested in the five-module education component. Routine staff training was a key variable in achieving proper implementation; the ideal would be a full day with repeated follow-up model teaching visits. Staff turnover was a logistic issue, as was programme leader readiness and interest in conducting the programme. Strong and significant effects were observed for the physical activity but not for the education component. The results of the physical education component suggest it is feasible, effective and ready for larger-scale evaluation or dissemination.
A theory for particle size segregation in shallow granular free-surface flows
Authors: Gray J.M.N.T , Thornton A.R 
Published: May 2005

Abstract
Granular materials composed of a mixture of grain sizes are notoriously prone to segregation during shaking or transport. In this paper, a binary mixture theory is used to formulate a model for kinetic sieving of large and small particles in thin, rapidly flowing avalanches, which occur in many industrial and geophysical free-surface flows. The model is based on a simple percolation idea, in which the small particles preferentially fall into underlying void space and lever large particles upwards. Exact steady-state solutions have been constructed for general steady uniform velocity fields, as well as time-dependent solutions for plug-flow, that exploit the decoupling of material columns in the avalanche. All the solutions indicate the development of concentration shocks, which are frequently observed in experiments. A shock-capturing numerical algorithm is formulated to solve general problems and is used to investigate segregation in flows with weak shear.
Active sites and states in the heterogeneous catalysis of carbon–hydrogen bonds
Authors: Somorjai Gabor A , Marsh Anderson L 
Published: May 2005

C–H bond activation for several alkenes (ethylene, propylene, isobutene, cyclohexene and 1-hexene) and alkanes (methane, ethane,
n
-hexane, 2-methylpentane and 3-methylpentane) has been studied on the (111) crystal face of platinum as a function of temperature at low (<10
−6
Torr) and high (≥1 Torr) pressures in the absence and presence of hydrogen pressures (≥10 Torr). Sum frequency generation (SFG) vibrational spectroscopy has been used to characterize the adsorbate structures and high pressure scanning tunnelling microscopy (HP-STM) has been used to monitor their surface mobility under reaction conditions during hydrogenation, dehydrogenation and CO poisoning. C–H bond dissociation occurs at low temperatures, approximately 250 K, for all of these molecules, although only at high pressures for the weakly bound alkanes because of their low desorption temperatures. Bond dissociation is known to be surface structure sensitive and we find that it is also accompanied by the restructuring of the metal surface. The presence of hydrogen slows down dehydrogenation and for some of the molecules it influences the molecular rearrangement, thus altering reaction selectivity. Surface mobility of adsorbates is essential to produce catalytic activity. When surface diffusion is inhibited by CO adsorption, ordered surface structures form and the reaction is poisoned. Ethylene hydrogenation is surface structure insensitive, while cyclohexene hydrogenation and dehydrogenation are structure sensitive.
n
-Hexane and other C
6
alkanes form either upright or flat-lying molecules on the platinum surface which react to produce branched isomers or benzene, respectively.
Activation of oxygen at metal surfaces
Authors: Carley A.F , Davies P.R , Roberts M.W 
Published: May 2005

Oxygen chemisorption at metal surfaces has been shown through a combination of scanning tunnelling microscopy and photoelectron spectroscopy to involve transient states that provide low energy pathways for a wide range of surface reactions including the catalytic oxidation of ammonia and hydrocarbons. The kinetically ‘hot’ transients are disordered and mobile, become unreactive when they form ordered structures, and are characterized by non-classical kinetic behaviour.The role of surface additives (caesium) in controlling oxygen structures and the implications of oxygen transients for theory and reaction mechanisms in applied catalysis are considered.
Effect of Race and Sex on Primary Care Physicians' Diagnosis and Treatment of Late‐Life Depression
Authors: Kales Helen C. , Neighbors Harold W. , Valenstein Marcia , Blow Frederic C. , McCarthy John F. , Ignacio Rosalinda V. , Taylor Kiran K.‐K. , Gillon Leah , Mellow Alan M. 
Published: May 2005

Objectives: To examine primary care physician (PCP) contributions toward racial and sex differences in the diagnosis and treatment of late‐life depression.Design: Survey using a computerized instrument incorporating video interviews and text, with volunteer PCPs randomly assigned to one of four standardized video vignettes of an elderly patient depicting late‐life depression. Vignettes differed only in the patient/actor's race (white/African‐American) or sex.Setting: American Academy of Family Physicians meeting, San Diego, California, 2002.Participants: One hundred seventy‐eight U.S.‐practicing postresidency PCPs who were asked to participate in a clinical decision‐making study.Measurements: The computerized survey instrument assessed PCPs' diagnoses, first‐line treatment and management recommendations, and judgment of personal characteristics/behaviors for the patients in the vignettes.Results: Eighty‐five percent of all PCPs correctly diagnosed the elderly patient(s) with major depression. There were no significant differences in the diagnosis of depression, treatment recommendations, or PCP assessment of most patient characteristics by the race or sex of the patient/actor in the vignette, but PCP characteristics, most notably the location of medical school training (U.S. vs international), affected the likelihood of a depression diagnosis and treatment recommendations.Conclusion: Given standardized symptom‐pictures, PCPs are just as likely to diagnose and treat depression in African‐American as in white older people, suggesting that bias based simply on apparent patient race is not a likely explanation for the lower rates of depression diagnosis and treatment in older African Americans. PCPs who have trained at international medical schools may benefit from targeted training initiatives on the diagnosis and treatment of late‐life depression.
Effects of Behavioral and Drug Therapy on Nocturia in Older Incontinent Women
Authors: Johnson Theodore M. , Burgio Kathryn L. , Redden David T. , Wright Kate Clark , Goode Patricia S. 
Published: May 2005

Objectives: To examine changes in nocturia from a multicomponent behavioral training program or drug therapy in older women with urge or mixed (urge‐predominant) urinary incontinence.Design: A secondary analysis of data from a prospective, randomized clinical trial.Setting: Parent trial was an outpatient research protocol in Alabama.Participants: One hundred ninety‐seven women (aged 55–92) with incontinence and urodynamic evidence of bladder dysfunction. At baseline, 131 women (66% of participants) had nocturia.Intervention: In the parent study, participants received behavioral training, including four sessions of biofeedback‐assisted pelvic floor muscle exercises, drug treatment (oxybutynin IR titrated from 2.5 mg per day to 5.0 mg three times a day), or placebo.Measurements: Participant‐completed bladder diaries were used to calculate changes in nocturia.Results: Behavioral training reduced nocturia by a median 0.50 episodes per night and was significantly more effective than drug treatment (median reduction=0.30 episodes; P=.02) and placebo (median reduction=0.00 episodes; P<.001). Also, drug treatment was more effective than control (P=.007).Conclusion: Both behavioral training and drug treatment reduced nocturia more than placebo, but behavioral training was the most effective.
Community‐Acquired Pneumonia in Patients Receiving Home Care
Authors: Marrie Thomas J. , Huang Jane Q. 
Published: May 2005

Objectives: To describe the features of community‐acquired pneumonia (CAP) requiring hospitalization in subjects receiving home care.Design: Prospective study from November 15, 2000, to November 14, 2002.Setting: Six hospitals in the Edmonton, Canada, area.Participants: Two thousand four hundred sixty‐four subjects aged 17 years and older with CAP, 21.9% of whom were receiving home care.Measurements: Pneumonia attack rates, demographic features, severity of illness, medication, length of stay, mortality, in hospital complications, and time to achieve physiological stability.Results: The overall rate of CAP requiring a visit to an emergency department in home care recipients was 25 per 1,000 person years, 90.8% of whom were admitted to the hospital for treatment. Patients who were receiving home care at the time of admission were older and less likely to be current tobacco smokers, had higher in‐hospital mortality (11%) and a longer length of stay, were receiving more medications, and had more comorbidity and fewer symptoms except for shortness of breath and altered mental state than those who were not receiving home care. Home care patients had four times as many myocardial infarctions and recurrent aspiration as the non‐home care patients. Falls occurred five times more often, and urinary catheters were inserted twice as often. Except for oxygen saturation, time to achieve physiological stability was the same for the two groups of patients. Half (51.2%) of the home care patients passed the get‐up‐and‐go test, compared with 75% (P<.001) of the non‐home care patients.Conclusion: Home care patients with CAP had an 11% mortality rate and a higher rate of complications than those who did not receive home care.