bluuebunny/crossref_metadata_2025 huggingface dataset:
Recurrence of lymphoedema‐associated cellulitis (erysipelas) under prophylactic antibiotherapy: a retrospective cohort study
Authors: Vignes S , Dupuy A
Published: June 2006

Objective  To identify the predictors of successful antibiotic prophylactic treatment using benzathin‐penicillin G to prevent recurrence of erysipelas in patients with secondary upper limb lymphoedema.

Design  A retrospective cohort study.

Setting and patients  Patients with secondary arm lymphoedema were recruited in a single lymphology unit between 1990 and 2003. All patients had had at least three recurrences of erysipelas. Patients were given 2.4 MU benzathin‐penicillin G intramuscularly at 14‐day intervals. For each patient, the following data were recorded: characteristics of breast cancer treatment (type of surgery, radiotherapy, hormone therapy), number of erysipelas recurrences before inclusion, patient characteristics including body mass index (BMI) and lymphoedema volume at inclusion.

Main outcome measures  The outcome studied was the occurrence of erysipelas on the affected arm under antibiotic prophylactic treatment.

Results  With a 4.2‐year median follow‐up from the onset of antibiotic prophylactic treatment, 23 of 48 women experienced recurrence of erysipelas. The median duration of erysipelas recurrence‐free period under this treatment was 2.7 years. The estimated rate of recurrence was 26%[95% confidence interval (CI) 13–38%] at 1 year and 36% (95% CI 22–50%) at 2 years. No patient stopped the treatment because of side‐effects. No predictive factor of erysipelas recurrence under antibiotic prophylactic treatment was identified.

Conclusions  Antibiotic prophylaxis using benzathin‐penicillin is a well‐tolerated treatment of erysipelas recurrence in patients with upper limb lymphoedema secondary to breast cancer. The rate of erysipelas recurrence was 26% at 1 year in patients who had a history of at least one erysipelas. We did not find any predictor of erysipelas recurrence.
Disappointing results and low tolerability of photodynamic therapy with topical 5‐aminolaevulinic acid in psoriasis. A randomized, double‐blind phase I/II study
Authors: Schleyer V , Radakovic‐Fijan S , Karrer S , Zwingers T , Tanew A , Landthaler M , Szeimies RM
Published: June 2006

Background  Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well‐documented trials.

Objective  A prospective randomized, double‐blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque‐type psoriasis.

Methods  In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm2 and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI).

Results  The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA‐treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation.

Conclusion  Topical ALA PDT did not prove to be an appropriate treatment option for plaque‐type psoriasis due to disappointing clinical efficacy, the time‐consuming treatment procedure and its unfavourable adverse event profile.
Impaired balance in developmental dyslexia? A meta‐analysis of the contending evidence
Authors: Rochelle Kim S.H. , Talcott Joel B.
Published: June 2006

Background:  Developmental dyslexia is typically defined by deficits in phonological skills, but it is also associated with anomalous performance on measures of balance. Although balance assessments are included in several screening batteries for dyslexia, the association between impairments in literacy and deficits in postural stability could be due to the high co‐occurrence of dyslexia with other developmental disorders in which impairments of motor behaviour are also prevalent.

Methods:  We identified 17 published studies that compared balance function between dyslexia and control samples and obtained effect‐sizes for each. Contrast and association analyses were used to quantify the influence of hypothesised moderator variables on differences in effects across studies.

Results:  The mean effect‐size of the balance deficit in dyslexia was .64 (95% CI = .44–.78) with heterogeneous findings across the population of studies. Probable co‐occurrence of other developmental disorders and variability in intelligence scores in the dyslexia samples were the strongest moderator variables of effect‐size.

Conclusions:  Balance deficits are associated with dyslexia, but these effects are apparently more strongly related to third variables other than to reading ability. Deficits of balance may indicate increased risk of developmental disorder, but are unlikely to be uniquely associated with dyslexia.
Macroscopic anatomy of the omasum of free‐ranging moose (Alces alces) and muskoxen (Ovibos moschatus) and a comparison of the omasal laminal surface area in 34 ruminant species
Authors: Clauss M. , Hofmann R. R. , Hummel J. , Adamczewski J. , Nygren K. , Pitra C. , Streich W.J. , Reese S.
Published: June 2006

The function of the ‘third compartment’ of the ruminant forestomach, the omasum, has been debated for a long time. To date, it is assumed that its major function is fluid reabsorption. In order to investigate differences in this organ between ruminant feeding types, we first compared macroscopic measurements of the omasa of free‐ranging muskoxenOvibos moschatus[n=6, mean body mass (BM) 207 kg, range 180–221], a grazer, and free‐ranging mooseAlces alces(n=11, mean BM 291 kg, range 144–418), a strict browser. Despite the similar BM range, omasa of muskoxen contained more ingesta, had a higher empty organ weight, had more third‐ and fourth‐order laminae, and represented a higher proportion of the total forestomach weight. In particular, the surface area of the omasal leaves – the area available for fluid absorption – was significantly larger in muskoxen (10 933±940 cm2) than in moose (2228±885 cm2). In order to test whether the difference in available surface area is a true functional correlate of feeding type, additional data on the omasal laminar surface area were generated for 83 individuals of 19 species. These data were supplemented with data on 13 additional species from the literature. The percentage of grass (%grass) in the natural diet was used to characterize the feeding type; the phylogenetic tree used for a controlled statistical evaluation was entirely based on mitochondrial DNA information. Regardless of phylogenetic control in the statistical treatment, there was a significant positive correlation of both BM and %grass in the natural diet with omasal laminar surface area. The data suggest that certain ruminant species that ingest more grass have larger omasal leaf surface areas, possibly indicating a higher need for water reabsorption distal to the ruminoreticulum, which could be explained as a consequence of the more distinct rumen contents stratification in these species.
Young Europeans abroad in Scotland: an exploration of how their attitudes to consumer credit reflect dimensions of culture
Authors: McKinnon Sabine , Schröder Monika J.A.
Published: June 2006

Nineteen young Europeans from across the Continent took part in in‐depth interviews where a wide range of consumer‐related issues were explored. These issues ranged from specific consumer behaviours and consumer value gained to consumer protection and other aspects of policy. Respondents were postgraduates studying at Scottish universities or young professionals currently working in Scotland. The interviews were structured around a number of key themes that were developed both from the literature and from an in‐depth pilot study. One of these themes was designed to explore the respondents’ attitudes towards saving and borrowing, in particular, consumer credit; and this forms the focus for the current paper. The theme had been developed initially with reference to Hofstede’s cultural dimension of ‘uncertainty avoidance’. However, it also successfully illuminated some of the other cultural dimensions in Hofstede’s typology. As anticipated, respondents tended to benchmark consumer culture in their home country against that of the host country (Scotland). What was surprising was the consensus with which they considered the Scottish/British consumers to be the ‘odd ones out’. This observed convergence appears to indicate that historical cultural differences between continental and Anglo‐Saxon cultures survive and may be stronger and more sustained than any differences between the post‐World War II socialist and market democracies.
Detergents, clothing and the consumer with sensitive skin
Authors: Rowe Helen Debra
Published: June 2006

A typical detergent formulation for domestic garment washing is a complex formulation comprising: surfactants, builders, bleaches and auxiliary agents. Repeated exposure to surfactants can cause damage to the lipid film layer of the skin. Textile constructions used in clothing are also complex. Most apparel fabrics will be subject to a laundering process containing detergent at some time in the life cycle and thus it can be surmised that the combination of clothing and detergent is likely to be the cause of some skin problems. Certain fibre types show higher absorption rates than others. If surfactants present in domestic detergents are preferentially absorbed into the fabric during laundering and inadequately removed by rinsing a build‐up of the surfactant may exacerbate skin irritation. This paper offers a review of the debate on the effects of detergents on skin disorders plus recent research on clothing and detergents.
Consumers’ everyday food choice strategies in Finland
Authors: Järvelä Katja , Mäkelä Johanna , Piiroinen Sanna
Published: June 2006

In developed countries, choosing and purchasing food is today perhaps more complex than ever. In recent years, European consumers have experienced several food crises. We face a rapidly expanding range of novel food products, the food chain has become longer, and the origin of food more anonymous. At the same time, consumers confront increasing amounts of information on food every day. Consumers build their conceptions of modern food‐related risks on the basis of their everyday knowledge and coping strategies. Hence, the focus of this paper is on consumers’ food choices and everyday practices in relation to food safety and quality as well as food‐related risks. The paper is based on a Finnish study1 examining consumers’ food choices. The data for the study were collected in September 2004 using an Internet‐based food diary accompanied by open‐ended questions on food‐related views and strategies. Altogether, 92 consumers completed the diary. The method combining the tradition of dietary intake and food consumption surveys with open‐ended questions was developed in order to gain an insight both on the types of foods purchased and on consumers’ conceptions of food‐related issues. In this paper, we focus on the key findings of the study as regards to consumers’ notions on food quality and safety issues and the practices they use in their everyday lives. We found eight everyday strategies consumers use. We suggest, first, that the strategies are important in simplifying food choice and making daily life easier, and second, that consumers use food‐related information flexibly in creating these strategies.
Child–mother nutrition and health status in rural Kenya: the role of intra‐household resource allocation and education
Authors: Marinda Pamela A.
Published: June 2006

There exists gender bias in resource ownership in many parts of Kenya with women being more disadvantaged. Resource ownership and control within the household has differential impacts on the health and overall well‐being of male and female members. This paper examines intra‐household resource ownership and how it affects nutrition and health status of household members. Data from a household survey containing detailed gender‐disaggregated information on resource ownership as well as food and anthropometry were collected from a rural Kenyan district and used in the analysis. Results showed that male members of the household had more access to education, income and land than the females. Mothers’ education, household income, frequency of illness and nutrient intake were the most important factors that contributed to the nutritional status of children. The education and household’s economic status were important determinants of child morbidity. Malnutrition and poor health of children and women is linked to the existing poverty in the study region, therefore emphasis needs to be put on eradication of discrimination against women in accessing education and accessing land, which will contribute to an increase in household incomes. Government policies need to focus on promotion of nutrition education through adult education programmes and incorporating it in the school curricula. Improvement of health‐care facilities in rural areas is also paramount to improving health and nutrition in these areas.
Leisure book reading and purchasing: an analysis of Turkish consumers
Authors: Ozturk Sevgi Ayse , Sevim Nurdan , Eroglu Elif
Published: June 2006

Tracking studies all over the world report a decline in time devoted to reading in all age groups. There is a common stereotype indicating that people prefer other leisure activities to reading books. Low levels of book readership and book purchasing has always been a matter of discussion in Turkey. Accordingly, the aim of this study was to develop a better understanding of Turkish people’s involvement with books. To achieve this aim, a research survey via self‐administered questionnaire to collect data about leisure time reading, book purchasing and related attitudes was prepared. The sample represents 601 people from eight cities. It was found that around 80% of the sample had read at least one book within the last 6 months, and 58% had purchased a book for her‐ or himself. In addition, a Likert scale with 26 items was utilized to understand the attitudes of respondents to book reading, purchasing and book marketing activities. A factor analysis was also used to check the possibility of reducing the number of attitude items on the scale. Four factors emerged as a result of the factor analysis, labelled as ‘high involvement in books’, ‘preference towards more visual products’, ‘economy factor’ and ‘books must be heavily promoted’. Furthermore, ANOVA and t‐tests were performed to analyse whether attitudes change with demographic variables. Contrary to common beliefs about book readership, this study has revealed favourable attitudes towards book reading and purchasing.
Quebec young adults’ use of and knowledge of credit
Authors: Lachance Marie J. , Beaudoin Pierre , Robitaille Jean
Published: June 2006

This research aimed to study young adults’ use of and knowledge of credit. A large representative sample of Quebec young adults aged 18–29 years participated in a telephone survey. Results reveal that their use of credit has increased remarkably over the last decade. The mean score on the credit knowledge scale used in this study is 49.4% for the entire group. Ordinary least squares (OLS) regression analysis show that credit knowledge is positively related to personal income, number of debts, amount of total debt, number of credit cards and favourable attitude towards credit and debts. Young adults reporting either personal experience or family and relatives as their main source of learning about personal finances were found to have a lower level of knowledge about credit in general than those reporting having learned of this subject from courses, the media or financial counsellors. The learning of basic knowledge about credit and personal finances, with stress on the sensible use of credit, should be part of the educational agenda for young consumers.
The central issue? Visceral fat mass is a good marker of insulin resistance and metabolic disturbance in women with polycystic ovary syndrome
Authors: Lord J , Thomas R , Fox B , Acharya U , Wilkin T
Published: June 2006

Objective  To establish whether visceral fat mass is the most significant variable correlating with insulin resistance and other metabolic parameters in women with polycystic ovary syndrome (PCOS).

Design  Prospective cross‐sectional trial.

Setting  Reproductive medicine clinic.

Population  Forty women with anovulatory PCOS.

Methods  Measurements were taken at recruitment, and analysis was performed to define correlations between the outcome measures and the explanatory variables.

Main outcome measures  Visceral and subcutaneous fat by computed tomography scan, insulin resistance, anthropometric measures, markers of the metabolic syndrome and androgens.

Results  Strong linear correlation of visceral fat to insulin resistance (r= 0.68, P < 0.001) was observed. There were also statistically significant correlations with fasting insulin (r= 0.73, P < 0.001), homeostasis model assessment β‐cell function (r= 0.50, P= 0.007), triglycerides (r= 0.45, P= 0.003), high‐density lipoprotein cholesterol (r=−0.42, P= 0.007), urate (r= 0.47, P= 0.002), Sex hormone binding globulin (r=−0.39, P= 0.01) and luteinising hormone (r=−0.32, P= 0.02). There were no significant correlations of testosterone with fat distribution or metabolic parameters. Insulin resistance showed closest correlation to visceral fat mass (r= 0.68, P < 0.001), then to waist circumference (r= 0.62, P < 0.001), with the weakest correlation being waist:hip ratio (r= 0.36, P= 0.01). The best regression model for predicting insulin resistance is with visceral fat mass and triglycerides as the explanatory variables (r= 0.72, P < 0.001).

Conclusions  Visceral fat is the most significant variable correlating with metabolic dysfunction in women with PCOS. Our data support the hypothesis that visceral fat either causes insulin resistance or is a very early effect of it. It also implies that reducing visceral fat should reduce insulin resistance which may account for the observations that exercise and weight loss appear to be more effective interventions than pharmacological treatments. The best anthropometric measure of insulin resistance is waist circumference.
Rates of neonatal death and cerebral palsy associated with fetal growth restriction among very low birthweight infants. A temporal analysis
Authors: Spinillo A , Gardella B , Preti E , Zanchi S , Stronati M , Fazzi E
Published: June 2006

Objective  To assess whether changes over time in neonatal survival and infants’ neurodevelopmental outcome among very low birthweight (VLBW) infants was correlated with the obstetric aetiology of VLBW.

Design  A cohort study of 773 VLBW infants.

Setting  A University hospital in Northern Italy.

Population  All the VLBW infants born over a 20‐year period (1983–2002) at a single institution.

Methods  Evaluation of neonatal mortality and neurodevelopmental outcome of the surviving infants at 2 years of corrected age. Logistic regression analysis was used to compare the improvements of neonatal outcome associated with obstetric risk factors over time.

Main outcome measures  The risk reduction of neonatal death or cerebral palsy associated with each obstetric category responsible for VLBW over time.

Results  The overall rates of neonatal mortality and cerebral palsy were 38.7% (43/111) and 17% (9/53) in the period 1983–87 and 13.7% (34/24) and 6.3% (13/205) in the period 1998–2002, respectively. The adjusted decrement per 5‐year period was 33.1% (95% CI = 7.9–51.4) for neonatal death and 29.1% (95% CI = 25.3–32.7) for cerebral palsy, respectively. The adjusted rise in the rate of intact survival at 2 years of corrected age was 7.6% (95% CI = 3.1–12.3) per quinquennium. In logistic models with neonatal death or cerebral palsy as a combined outcome variable, and gestational age, corticosteroid use, surfactant use, and time of birth as explanatory variables, fetal growth restriction (P < 0.001) and pre‐eclampsia (P= 0.011) interacted significantly with period of birth. The adjusted decrement in the rate of neonatal death or cerebral palsy as a combined variable was 27.5% per 5 years (95% CI = 13–39.6) in the overall population, 54.5% per 5 years (95% CI = 46.8–61.2) (P < 0.001 compared with overall population) among growth‐restricted infants and 50.3% per 5 years (95% CI = 42.5–57.1) (P= 0.003 compared with overall population) in infants born to mothers with pre‐eclampsia.

Conclusions  Over a period of 20 years, the decrement in the rate of neonatal death or cerebral palsy was higher in growth‐restricted fetuses than in other VLBW infants. This reduction was not obtained at the expense of an increased rate of neurodevelopmental impairments in surviving infants.
Protease‐activated receptor‐1 protects rat astrocytes from apoptotic cell death via JNK‐mediated release of the chemokine GRO/CINC‐1
Authors: Wang Yingfei , Luo Weibo , Stricker Rolf , Reiser Georg
Published: June 2006

Thrombin at low doses is an endogenous mediator of protection in ischaemic and haemorrhagic models of stroke. However, the mechanism of thrombin‐induced protection remains unclear. Recently accumulating evidence has shown that astrocytes play an important role in the brain after injury. We report that thrombin and thrombin receptor agonist peptide (TRag) up‐regulated secretion of the chemokine growth‐regulated oncogene/cytokine‐induced neutrophil chemoattractant‐1 (GRO/CINC‐1) in primary rat astrocytes in a concentration‐dependent manner. However, we found no increase of interleukin (IL)‐6, IL‐1β and tumour necrosis factor‐α secretion. Protease‐activated receptor 1 (PAR‐1)‐induced GRO/CINC‐1 release was mainly mediated by c‐Jun N‐terminal kinase (JNK) activation. Extracellular signal‐regulated kinase 1/2 might be partially involved, but not p38 mitogen‐activated protein kinase. Further studies demonstrated that PAR‐1 activation, as well as application of recombinant GRO/CINC‐1, protected astrocytes from C2‐ceramide‐induced cell death. Protection occurred with suppression of cytochrome c release from mitochondria. The inhibition of cytochrome c release was largely reduced by the antagonist of chemokine receptor CXCR2, SB‐332235. Importantly, a specific JNK inhibitor significantly abolished the protective action of PAR‐1. These results demonstrate for the first time that PAR‐1 plays an important role in anti‐apoptosis in the brain by regulating the release of chemokine GRO/CINC‐1, which gives a feedback through its receptor CXCR2 to preserve astrocytes from toxic insults.
Up‐regulation of NMDA receptor subunit and post‐synaptic density protein expression in the thalamus of elderly patients with schizophrenia
Authors: Clinton Sarah M. , Haroutunian Vahram , Meador‐Woodruff James H.
Published: June 2006

Numerous studies have described structural and functional abnormalities of the thalamus in schizophrenia, but surprisingly few studies have examined neurochemical abnormalities that accompany these pathological changes. We previously identified abnormalities of multiple molecules associated with glutamatergic neurotransmission, including changes in NMDA receptor subunit transcripts and binding sites and NMDA receptor‐associated post‐synaptic density (PSD) protein transcripts in the thalamus of elderly patients with schizophrenia. In the present study, we performed western blot analysis to determine whether protein levels of NMDA receptor subunits (NR1, NR2A, NR2B) and associated PSD proteins (NF‐L, PSD95, SAP102) are altered in schizophrenia. Thalamic tissue from each subject was grossly dissected into two regions: a dorsomedial region containing limbic‐associated dorsomedial, anterior and central medial thalamic nuclei; and a ventral thalamus region that primarily consisted of the ventral lateral nucleus. We observed increased protein expression of the NR2B NMDA receptor subunit and its associated intracellular protein, PSD95, in the dorsomedial thalamus of patients with schizophrenia, but the other molecules were unchanged, and we found no changes in the ventral thalamus. These data provide additional evidence of thalamic neurochemical abnormalities, particularly in thalamic nuclei which project to limbic regions of the brain. Further, these findings provide additional evidence of NMDA receptor alterations in schizophrenia, which may play an important role in the neurobiology of the illness.
Isolation and characterization of 125 microsatellite DNA markers in the blacklip abalone, Haliotis rubra
Authors: BARANSKI MATTHEW , ROURKE MEAGHAN , LOUGHNAN SHANNON , AUSTIN CHRIS , ROBINSON NICK
Published: June 2006

Australian abalone species are subject to wild harvest and aquaculture production. This study characterized 125 polymorphic microsatellite markers in the blacklip abalone, Haliotis rubra, and evaluated cross‐species amplification in Haliotis laevigata and Haliotis coccoradiata. Segregation analysis of a mapping family revealed non‐amplifying polymerase chain reaction null alleles at 34 loci. Cross‐species amplification was achieved for 89 loci.
Laser‐assisted microdissection of polytene chromosomes from Diptera for the development of molecular markers
Authors: POST RORY J. , KRÜGER ANDREAS , SOMIARI STELLA B.
Published: June 2006

The structural details visible under the light microscope have made polytene chromosomes from Diptera much used in studies of the taxonomy, evolution and genetics of important biological models such as Drosophila and Chironomus, and the medical entomology of important disease vectors such as blackflies and mosquitoes. This paper describes the isolation of sections of polytene chromosomes from preserved wild‐caught blackflies using off‐the‐shelf laser microdissection microscopy and subsequent analysis of the DNA using polymerase chain reaction. This allows a direct link between the visible structure of the genome and the unknown DNA sequence, facilitating the development of molecular markers for population cytogenetics and cytotaxonomy.
Co‐amplification of cytochrome b and D‐loop mtDNA fragments for the identification of degraded DNA samples
Authors: YANG DONGYA Y. , SPELLER CAMILLA F.
Published: June 2006

We propose a simple and effective approach to simultaneously co‐amplify both cytochrome b and D‐loop fragments to evaluate DNA preservation and to monitor possible contaminations in the analysis of degraded animal DNA samples. We have applied this approach to over 200 ancient salmon samples and 25 ancient whale DNA samples, clearly demonstrating its multiple benefits for analysis of degraded DNA samples, and the ease in which co‐amplification can be optimized for different taxa. This simple, cost‐efficient and genomic DNA‐saving approach can be used routinely in the analysis of minute and degraded DNA samples in wildlife forensics, food inspection, conservation biology and ancient faunal remains.
aflpdat: a collection of r functions for convenient handling of AFLP data
Authors: EHRICH DOROTHEE
Published: June 2006

aflpdat is a collection of R functions that facilitates the handling of dominant genotypic data. It converts data from a standard tab‐separated table to the input formats of the following programs: arlequin, structure, treecon, paup and hickory. In addition, it calculates the proportion of polymorphic markers in each population, and estimates gene diversity as the average proportion of pairwise differences between individuals with confidence intervals based on bootstrapping across markers. It also produces summary tables of marker frequencies and the presence or absence of markers in each population. aflpdat can be downloaded from http://www.nhm.uio.no/ncb/.
Isolation of polymorphic microsatellite loci in Hemerocallis fulva and Hemerocallis citrina (Hemerocallidaceae)
Authors: MIYAKE TAKASHI , YAHARA TETSUKAZU
Published: June 2006

Twenty microsatellite loci were isolated from a hybrid of two daylilies, Hemerocallis fulva and Hemerocallis citrina. We characterized individuals from two H. fulva populations and two H. citrina populations in Japan and observed three to 20 alleles per locus in H. fulva and one to 19 alleles per locus in H. citrina. Mean observed heterozygosity within populations ranged from 0.35 to 0.85 in H. fulva and from 0 to 0.95 in H. citrina. In about a half of the loci, the observed heterozygosity did not deviate from Hardy–Weinberg equilibrium. These loci are proved useful in studying gene flow and qualitative trait loci mapping using the two species.
Treatment of Uncorrected Refractive Error Improves Vision‐Specific Quality of Life
Authors: Coleman Anne L. , Yu Fei , Keeler Emmett , Mangione Carol M.
Published: June 2006

OBJECTIVES: To evaluate the benefit of eyeglasses and magnifiers in elderly patients with uncorrected refractive errors.

DESIGN: A single‐center, randomized, prospective, controlled trial (September 2001 to August 2003).

SETTING: Los Angeles County, California.

PARTICIPANTS: One hundred thirty‐one community‐dwelling persons aged 65 and older who had habitual distance visual acuity of 20/32 or worse and whose distant visual acuity, near visual acuity, or both could be improved with eyeglasses, a magnifier, or both by two lines of acuity or more.

INTERVENTION: Sixty‐six were randomized to receive a prescription and voucher for free eyeglasses, a magnifier, or both immediately, and 65 were randomized to receive a prescription and voucher after the 3‐month follow‐up visit (the control group).

MEASUREMENTS: Primary outcome was vision‐specific functioning as measured using the 25‐item National Eye Institute—Visual Functioning Questionnaire (NEI‐VFQ). Secondary outcomes were distance and near visual acuity and overall functioning as measured using the Rosow‐Breslau function questionnaire.

RESULTS: In the intention‐to‐treat analysis of 3‐month follow‐up data, participants who received the eyeglasses prescription and voucher immediately had greater improvement in NEI‐VFQ composite scores than the control group (P<.01). They also had greater improvement in perceptions of their general vision (P<.01), distance visual acuity (P=.03), near visual acuity (P=.04), and mental health (P=.02).

CONCLUSION: Correction of uncorrected refractive error, one of the leading causes of visual impairment in older people, improved the vision‐specific quality of life of community‐dwelling older persons.
A General Approach for Two‐Stage Analysis of Multilevel Clustered Non‐Gaussian Data
Authors: Chervoneva Inna , Iglewicz Boris , Hyslop Terry
Published: June 2006

Summary In this article, we propose a two‐stage approach to modeling multilevel clustered non‐Gaussian data with sufficiently large numbers of continuous measures per cluster. Such data are common in biological and medical studies utilizing monitoring or image‐processing equipment. We consider a general class of hierarchical models that generalizes the model in the global two‐stage (GTS) method for nonlinear mixed effects models by using any square‐root‐n‐consistent and asymptotically normal estimators from stage 1 as pseudodata in the stage 2 model, and by extending the stage 2 model to accommodate random effects from multiple levels of clustering. The second‐stage model is a standard linear mixed effects model with normal random effects, but the cluster‐specific distributions, conditional on random effects, can be non‐Gaussian. This methodology provides a flexible framework for modeling not only a location parameter but also other characteristics of conditional distributions that may be of specific interest. For estimation of the population parameters, we propose a conditional restricted maximum likelihood (CREML) approach and establish the asymptotic properties of the CREML estimators. The proposed general approach is illustrated using quartiles as cluster‐specific parameters estimated in the first stage, and applied to the data example from a collagen fibril development study. We demonstrate using simulations that in samples with small numbers of independent clusters, the CREML estimators may perform better than conditional maximum likelihood estimators, which are a direct extension of the estimators from the GTS method.
Local Influence Diagnostics for Quasi‐Likelihood and Lognormal Estimates of a Biological Reference Point from Some Fish Stock and Recruitment Models
Authors: Cadigan N. G.
Published: June 2006

SummaryWe present local influence diagnostics to measure the sensitivity of a biological limit reference point (LRP) estimated from fitting a model to stock and recruitment data. LRPs are low levels of stock size that the management of commercial fisheries should avoid with high probability. The LRP we examine is the stock size at which recruitment is 50% of the maximum (S50%). We derive analytic equations to describe the effects onS50%of changing the weight that observations are given in estimation. We derive equations for the Ricker, Beverton–Holt, and hockey‐stick stock‐recruit models, and four estimation methods including the error sums of squares method on log responses and three quasi‐likelihood methods. We conclude from case studies that the hockey‐stick model produces the most robust estimates.
Estimation of the Mean from Sums with Unknown Numbers of Summands
Authors: Ninan Ipe , Arancio Ottavio , Rabinowitz Daniel
Published: June 2006

Summary Using dye intensity measurements at synaptic terminals to examine neurotransmitter release leads to the problem of estimating an expectation when, instead of observing independent random variables with the same expectation, one observes, with error, independent random sums of independent variables with the same expectation—but with the number of summands in the random sums unobserved. Here, a relatively convenient nonparametric approach to estimation is presented. Data from an experiment in which cationic styrylpyridinium dye FM4‐64 was used in cultured mouse hippocampal neurons are used to illustrate the approach.
Polynomial Spline Estimation and Inference of Proportional Hazards Regression Models with Flexible Relative Risk Form
Authors: Huang Jianhua Z. , Liu Linxu
Published: June 2006

SummaryThe Cox proportional hazards model usually assumes an exponential form for the dependence of the hazard function on covariate variables. However, in practice this assumption may be violated and other relative risk forms may be more appropriate. In this article, we consider the proportional hazards model with an unknown relative risk form. Issues in model interpretation are addressed. We propose a method to estimate the relative risk form and the regression parameters simultaneously by first approximating the logarithm of the relative risk form by a spline, and then employing the maximum partial likelihood estimation. An iterative alternating optimization procedure is developed for efficient implementation. Statistical inference of the regression coefficients and of the relative risk form based on parametric asymptotic theory is discussed. The proposed methods are illustrated using simulation and an application to the Veteran's Administration lung cancer data.
Motor Unit Number Estimation—A Bayesian Approach
Authors: Ridall P. Gareth , Pettitt Anthony N. , Henderson Robert D. , McCombe Pamela A.
Published: June 2006

SummaryAll muscle contractions are dependent on the functioning of motor units. In diseases such as amyotrophic lateral sclerosis (ALS), progressive loss of motor units leads to gradual paralysis. A major difficulty in the search for a treatment for these diseases has been the lack of a reliable measure of disease progression. One possible measure would be an estimate of the number of surviving motor units. Despite over 30 years of motor unit number estimation (MUNE), all proposed methods have been met with practical and theoretical objections. Our aim is to develop a method of MUNE that overcomes these objections. We record the compound muscle action potential (CMAP) from a selected muscle in response to a graded electrical stimulation applied to the nerve. As the stimulus increases, the threshold of each motor unit is exceeded, and the size of the CMAP increases until a maximum response is obtained. However, the threshold potential required to excite an axon is not a precise value but fluctuates over a small range leading to probabilistic activation of motor units in response to a given stimulus. When the threshold ranges of motor units overlap, there may be alternation where the number of motor units that fire in response to the stimulus is variable. This means that increments in the value of the CMAP correspond to the firing of different combinations of motor units. At a fixed stimulus, variability in the CMAP, measured as variance, can be used to conduct MUNE using the “statistical” or the “Poisson” method. However, this method relies on the assumptions that the numbers of motor units that are firing probabilistically have the Poisson distribution and that all single motor unit action potentials (MUAP) have a fixed and identical size. These assumptions are not necessarily correct. We propose to develop a Bayesian statistical methodology to analyze electrophysiological data to provide an estimate of motor unit numbers. Our method of MUNE incorporates the variability of the threshold, the variability between and within single MUAPs, and baseline variability. Our model not only gives the most probable number of motor units but also provides information about both the population of units and individual units. We use Markov chain Monte Carlo to obtain information about the characteristics of individual motor units and about the population of motor units and the Bayesian information criterion for MUNE. We test our method of MUNE on three subjects. Our method provides a reproducible estimate for a patient with stable but severe ALS. In a serial study, we demonstrate a decline in the number of motor unit numbers with a patient with rapidly advancing disease. Finally, with our last patient, we show that our method has the capacity to estimate a larger number of motor units.
Generalized Additive Modeling with Implicit Variable Selection by Likelihood‐Based Boosting
Authors: Tutz Gerhard , Binder Harald
Published: June 2006

SummaryThe use of generalized additive models in statistical data analysis suffers from the restriction to few explanatory variables and the problems of selection of smoothing parameters. Generalized additive model boosting circumvents these problems by means of stagewise fitting of weak learners. A fitting procedure is derived which works for all simple exponential family distributions, including binomial, Poisson, and normal response variables. The procedure combines the selection of variables and the determination of the appropriate amount of smoothing. Penalized regression splines and the newly introduced penalized stumps are considered as weak learners. Estimates of standard deviations and stopping criteria, which are notorious problems in iterative procedures, are based on an approximate hat matrix. The method is shown to be a strong competitor to common procedures for the fitting of generalized additive models. In particular, in high‐dimensional settings with many nuisance predictor variables it performs very well.
A Goodness‐of‐Fit Test for Multinomial Logistic Regression
Authors: Goeman Jelle J. , le Cessie Saskia
Published: June 2006

Summary This article presents a score test to check the fit of a logistic regression model with two or more outcome categories. The null hypothesis that the model fits well is tested against the alternative that residuals of samples close to each other in covariate space tend to deviate from the model in the same direction. We propose a test statistic that is a sum of squared smoothed residuals, and show that it can be interpreted as a score test in a random effects model. By specifying the distance metric in covariate space, users can choose the alternative against which the test is directed, making it either an omnibus goodness‐of‐fit test or a test for lack of fit of specific model variables or outcome categories.
Extension of the Rank Sum Test for Clustered Data: Two‐Group Comparisons with Group Membership Defined at the Subunit Level
Authors: Rosner Bernard , Glynn Robert J. , Lee Mei‐Ling T.
Published: June 2006

Summary The Wilcoxon rank sum test is widely used for two‐group comparisons for nonnormal data. An assumption of this test is independence of sampling units both between and within groups. In ophthalmology, data are often collected on two eyes of an individual, which are highly correlated. In ophthalmological clinical trials, randomization is usually performed at the subject level, but the unit of analysis is the eye. If the eye is used as the unit of analysis, then a modification to the usual Wilcoxon rank sum variance formula must be made to account for the within‐cluster dependence. For some clustered data designs, where the unit of analysis is the subunit, group membership may be defined at the subunit level. For example, in some randomized ophthalmologic clinical trials, different treatments may be applied to fellow eyes of some patients, while the same treatment may be applied to fellow eyes of other patients. In general, binary eye‐specific covariates may be present (scored as exposed or unexposed) and one wishes to compare nonnormally distributed outcomes between exposed and unexposed eyes using the Wilcoxon rank sum test while accounting for the clustering. In this article, we present a corrected variance formula for the Wilcoxon rank sum statistic in the setting of eye (subunit)‐specific covariates. We apply it to compare ocular itching scores in ocular allergy patients between eyes treated with active versus placebo eye drops, where some patients receive the same eye drop in both eyes, while other patients receive different eye drops in fellow eyes. We also present comparisons between the clustered Wilcoxon test and each of the signed rank tests and mixed model approaches and show dramatic differences in power in favor of the clustered Wilcoxon test for some designs.
Optimization of Two‐Stage Genetic Designs Where Data Are Combined Using an Accurate and Efficient Approximation for Pearson's Statistic
Authors: Bukszár József , van den Oord Edwin J. C. G.
Published: June 2006

Summary There is an increasing interest in the use of two‐stage case‐control studies to reduce genotyping costs in the search for genes underlying common disorders. Instead of analyzing the data from the second stage separately, a more powerful test can be performed by combining the data from both stages. However, standard tests cannot be used because only the markers that are significant in the first stage are selected for the second stage and the test statistics at both stages are dependent because they partly involve the same data. Theoretical approximations are not available for commonly used test statistics and in this specific context simulations can be problematic because of the computational burden. We therefore derived a cost‐effective, that is, accurate but fast in terms of central processing unit (CPU) time, approximation for the distribution of Pearson's statistic on 2 ×m contingency tables in two‐stage design with combined data. We included this approximation in an iterative method for designing optimal two‐stage studies. Simulations supported the accuracy of our approximation. Numerical results confirmed that the use of two‐stage designs reduces the genotyping burden substantially. Compared to not combining data, combining the data decreases the required sample sizes on average by 15% and the genotyping burden by 5%.
Determinants of farmers' preference for alternative animal health service providers in Kenya: a proportional hazard application
Authors: Irungu P. , Omiti J. M. , Mugunieri L. G.
Published: June 2006

One hundred and eighty farmers in the semiarid Makueni district, Kenya, were surveyed using a structured questionnaire. The objective was to assess factors that influence farmers' preference for alternative veterinary service providers following the liberalization of veterinary services. A proportional hazard model was fitted to the data because of its ability to accommodate simultaneously the attributes of both the chooser and the choice. Of the three service providers considered in the study, community‐based animal health workers were the most preferred followed by veterinary surgeons and animal health assistants. Farmers' age and education level were inversely but significantly related to the probability of choosing any of the three service providers. Distance to the preferred service provider was the main choice‐specific attribute with a significant impact on the choice probability. A high preference for community‐based animal health workers was noted suggesting the possibility of poorly trained animal health workers dominating the veterinary services market in remote areas of Kenya. Efforts geared toward the legalization of community‐based animal health workers in Kenya and elsewhere in the developing countries should first address the constraints that hinder the penetration of professional veterinary service providers in remote areas.
An option perspective on generating and maintaining plant variety rights in China
Authors: Koo Bonwoo , Pardey Philip G. , Qian Keming , Zhang Yi
Published: June 2006

Notwithstanding the ambiguous research and productivity promoting effects of plant variety protections (PVPs) even in developed countries, many developing countries have adopted PVPs in the past few years, in part to comply with their Trade‐Related Aspects of Intellectual Property Rights (TRIPS) obligations. Seeking and maintaining PVPs reserves options to an expected revenue stream from the future sale of protected varieties, the value of which varies for a host of reasons. In this article we empirically examine the pattern of PVP applications in China since its PVP laws were first introduced in 1997. We place those PVP rights in the context of China's present and likely future seed markets to identify the economic incentives and institutional influences on decisions to develop and apply for varietal rights.
Prices of American Pinot Noir wines: climate, craftsmanship, critics
Authors: Haeger John W. , Storchmann Karl
Published: June 2006

Pinot Noir, a variety originating from Burgundy in France, is the most expensive category of table wine produced in North America. This article is aimed at analyzing its price determinants and focuses on climate, critical scores, and variables related to the winemaker. The main findings are as follows: (1) Pinot Noir prices are mainly determined by temperature and precipitation. General temperature increases are not beneficial. In fact, the optimal climate is similar to that in Burgundy. (2) The second most important variable is the winemaker. His or her skill and reputation have a significant impact on prices. (3) Expert knowledge, in the form of critical scores, has little explanatory value.
Do stronger intellectual property rights induce more agricultural trade?: a dynamic panel data model applied to seed trade
Authors: Yang Chih‐Hai , Woo Rhung‐Jieh
Published: June 2006

Do stronger intellectual property rights (IPRs) induce more agricultural trade? Based on panel data for 60 countries during 1990–2000 and using a dynamic panel data model, this article assesses whether and how national differences in IPRs affect the trade flow of planting seeds imports from the United States. The empirical results show that whether or not a country adheres to IPRs agreements has no discernible impact on planting seeds that are imported from the United States, implying that the strengthening of IPRs seems not to induce more agricultural trade. This result sheds some light on the debate in the theoretical literature on the importance of IPRs and trade.