bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robust statistical methods for analysis of biomarkers measured with batch/experiment‐specific errors
Authors: Long Qi , Flanders W. Dana , Fedirko Veronika , Bostick Roberd M. 
Published: December 2009

AbstractIn many biological studies, biomarkers are measured with errors. In addition, study samples are often divided and measured in separate batches, and data collected from different experiments are used in a single analysis. Generally speaking, the structure of the measurement error is unknown and is not easy to ascertain. While the conditions under which the measurements are taken vary from one batch/experiment to another, they are often held steady within each batch/experiment. Thus, the measurement error can be considered batch/experiment specific, that is, fixed within each batch/experiment, which results into a rank‐preserving property within each batch/experiment. Under this condition, we study robust statistical methods for analyzing the association between an outcome variable and predictors measured with error, and evaluating the diagnostic or predictive accuracy of these biomarkers. Our methods require no assumptions on the structure and distribution of the measurement error, which are often unrealistic. Compared with existing methods that are predicated on normality and additive structure of measurement errors, our methods still yield valid inferences under departure from these assumptions. The proposed methods are easy to implement using off‐shelf software. Simulation studies show that under various measurement error structures, the performance of the proposed methods is satisfactory even for a fairly small sample size, whereas existing methods under misspecified structures and a naive approach exhibited substantial bias. Our methods are illustrated using a biomarker validation case–control study for colorectal neoplasms. Copyright © 2009 John Wiley & Sons, Ltd.
Specification of covariance structure in longitudinal data analysis for randomized clinical trials
Authors: Lu Kaifeng , Mehrotra Devan V. 
Published: December 2009

AbstractMisspecification of the covariance structure for repeated measurements in longitudinal analysis may lead to biased estimates of the regression parameters and under or overestimation of the corresponding standard errors in the presence of missing data. The so‐called sandwich estimator can ‘correct’ the variance, but it does not reduce the bias in point estimates. Removing all assumptions from the covariance structure (i.e. using an unstructured (UN) covariance) will remove such biases. However, an excessive amount of missing data may cause convergence problems for iterative algorithms, such as the default Newton–Raphson algorithm in the popular SAS PROC MIXED. This article examines, both through theory and simulations, the existence and the magnitude of these biases. We recommend the use of UN covariance as the default strategy for analyzing longitudinal data from randomized clinical trials with moderate to large number of subjects and small to moderate number of time points. We also present an algorithm to assist in the convergence when the UN covariance is used. Copyright © 2009 John Wiley & Sons, Ltd.
Conversion of Ancestral Fibroblasts to Induced Pluripotent Stem Cells
Authors: Araki Ryoko , Jincho Yuko , Hoki Yuko , Nakamura Miki , Tamura Chihiro , Ando Shunsuke , Kasama Yasuji , Abe Masumi 
Published: December 2009

Abstract
The emergence of induced pluripotent stem cells (iPSCs) from an ancestral somatic cell is one of the most important processes underlying their generation, but the mechanism has yet to be identified. This is principally because these cells emerge at a low frequency, about 0.1% in the case of fibroblasts, and in a stochastic manner. In our current study, we succeeded in identifying ancestral fibroblasts and the subsequent processes leading to their conversion to iPSCs. The ancestral fibroblasts were found to divide several times in a morphologically symmetric manner, maintaining a fibroblastic shape, and then gradually transform into embryonic stem-like cells. Interestingly, this conversion occurred within 48 hours after gene introduction in most iPSC generations. This is the first report to directly observe a cell lineage conversion of somatic cells to stem cells and provides a critical new insight into the “black box” of iPSCs, that is, the first three days of their generation.
Determination of Deep Frying Soybean Oil Disposal Point by a Sensory Method
Authors: Ravelli Débora , Matsuoka Carla Romero , Della Modesta Regina Célia , Vieira Thais Maria Ferreira de Souza , Regitano‐d'Arce Marisa Aparecida Bismara 
Published: December 2009

AbstractMeasurements of degradation in frying oils are mainly based on physico‐chemical properties. Total polar compounds (TPC) and free fatty acids (FFA) content in frying oils are used as a guide for discarding used oils. The purpose of this study was to evaluate the efficacy of a sensory method in detecting degradation in soybean oils used in potato chips deep frying. The sensory evaluation of oil samples was determined by a trained panel; after rigorous selection and training steps. Free fatty acid, TPC and Rancimat induction period (IP) were quantified in the same samples. The proposed sensory method was sensitive to small differences in rancidity. The selected and trained sensory panel discarded oil samples with 0.175% FFA as oleic acid, 18.92% TPC, and 0.20 h IP. According to the results achieved in this research sensorial trained panel response is sensitive and accurate in refusing deteriorated frying oils. Besides this, soybean oil can be used for deep frying procedures and safely discarded according to the panel response, although presenting up to 7% linolenic acid.
Juvenile osteochondritis of femoral condyles: Treatment with transchondral drilling. Analysis of 40 cases
Authors: Hayan Rammal , Phillipe Gicquel , Ludovic Schneider , Claude Karger , Jean-Michel Clavert 
Published: December 2009

Introduction Osteochondritis dissecans (OCD) of the femoral condyle is a rare lesion. Materials and methods A retrospective study (level IV evidence) analyzing a series of 40 pediatric cases with juvenile femoral condyles osteochondritis treated by arthroscopic multiple transchondral drilling between February 1999 and June 2008 was undertaken. This lesion affected the medial condyle in 87.5% of cases. The average age at treatment was 13.4 years. Our study took into account the location of the lesion and its radiological evolutionary stage. The average follow up was 14.8 months. The postoperative evaluation was based on the clinical and radiological scores of Hughston. Results Good clinical and radiological results in 97.5 and 95% of cases, respectively were obtained, with a significant correlation ( P < 0.001) between clinical scores and radiological Hughston scores. The closed nature of the growth plate during surgery has a significant deleterious effect ( P < 0.001) on the clinical and radiological score of Hughston. Conclusion All patients presenting juvenile condylar osteochondritis with open growth plate during treatment had good clinical and radiological results, confirming the validity and effectiveness of multiple transchondral drilling in this type of lesion.
Verbal fluency as a possible predictor for psychosis
Authors: Becker H.E. , Nieman D.H. , Dingemans P.M. , van de Fliert J.R. , De Haan L. , Linszen D.H. 
Published: December 2009

AbstractBackgroundNeurocognitive abnormalities are prevalent in both first episode schizophrenia patients and in ultra high risk (UHR) patients.AimTo compare verbal fluency performance at baseline in UHR in patients that did and did not make the transition to psychosis.MethodBaseline verbal fluency performance in UHR-patients (n = 47) was compared to match first episode patients (n = 69) and normal controls (n = 42).ResultsVerbal fluency (semantic category) scores in UHR-patients did not differ significantly from the score in first episode schizophrenia patients. Both the UHR group (p < 0.003) and the patient group (p < 0.0001) performed significantly worse than controls. Compared to the non-transition group, the transition group performed worse on verbal fluency, semantic category (p < 0.006) at baseline.ConclusionsVerbal fluency (semantic category) is disturbed in UHR-patients that make the transition to psychosis and could contribute to an improved prediction of transition to psychosis in UHR-patients.
Do treatment and illness beliefs influence adherence to medication in patients with bipolar affective disorder? A preliminary cross-sectional study
Authors: Hou R. , Cleak V. , Peveler R. 
Published: December 2009

AbstractAdherence to medication is essential for achieving good outcomes for patients with bipolar affective disorder. This study tested whether treatment and illness beliefs are important predictors of adherence to medication. Results indicate that beliefs are predictive, and may be a suitable target for modification in efforts to change behaviour.
Long‐term effects of high lipid and high energy diet on serum lipid, brain fatty acid composition, and memory and learning ability in mice
Authors: Yu Huanling , Bi Yanxia , Ma Weiwei , He Lingling , Yuan Linhong , Feng Jinfang , Xiao Rong 
Published: December 2009

AbstractObjectiveIt is well known that high lipid and high energy diet is harmful to health. But the different effects of high lipid diet composed of either saturated fatty acids or unsaturated fatty acids have not been distinguished.MethodEighteen pregnant C57BL/6j (22–25 g) mice were randomly divided into three groups of six each and fed with chow or high lipid diet composed of either flaxseed oil (chow diet 84%, cholesterol 0.2%, flaxseed oil 15.8%) or lard fat (chow diet 84%, cholesterol 0.2%, lard fat 15.8%). After weaning, the offspring were fed the same diet as their mothers were fed during the experiment, and their spatial memory and learning ability were evaluated by Morris water maze when they were 8 weeks old. Next, the blood and tissues were sampled when they were 9 weeks old. Serum lipids were determined using kits, and brain fatty acids were measured using a gas chromatograph.ResultsCompared to chow diet (control), high flaxseed oil diet (HFO) increased high density lipoprotein cholesterol level (HDL‐C) in the mothers but not in offspring; high lard fat diet (HLF) increased serum total cholesterol level (TC) and low density lipoprotein cholesterol level (LDL‐C) both in mothers and offspring. Brain fatty acids profile was altered by HLF compared with chow diet. Polyunsaturated fatty acids and long‐chain polyunsaturated fatty acids content were significantly lower in the HLF group than in the control group, but saturated fatty acids content were significantly higher in HLF group than those in control group. The changed fatty acids composition affected the spatial memory and learning ability of adult offspring.ConclusionsA long‐term high lard diet increased offspring serum TC and LDL‐C levels and affected the brain's fatty acid composition, and memory and learning ability. The polyunsaturated fatty acid content of the brain may be correlated with serum cholesterol levels.
Urinary incontinence in hospital‐based nurses working in Turkey
Authors: Yağmur Yurdagül , Ulukoca Neşe 
Published: December 2009

AbstractObjectiveTo determine the changes in quality of life due to urinary incontinence in female hospital‐based nurses working in Turkey and whether professional help was sought by the nurses. Another aim was to determine the prevalence of urinary incontinence and its risk factors in working nurses.MethodsData were collected through administration of a questionnaire and the Incontinence Quality‐of‐Life Instrument. The data were analyzed via χ2 test, t test, one‐way analysis of variance, and binary logistic regression analysis.ResultsThe prevalence of urinary incontinence was 21.5%. Explanatory variables for developing urinary incontinence were age, parity, and recurrent urinary tract infections. Nurses with stress incontinence or urge incontinence had better quality of life than did those with mixed incontinence.ConclusionIn the present study, urinary incontinence was common in working nurses, and had a negative impact on their general quality of life.
Prepregnancy body mass index, gestational weight gain, and pregnancy outcomes in China
Authors: Chen Zhenyu , Du Juan , Shao Ling , Zheng Liqiang , Wu Meiyan , Ai Mo , Zhang Yinling 
Published: December 2009

AbstractObjectiveTo look for associations between pregnancy outcomes and prepregnancy body mass index and gestational weight gain among Han women from Shenyang province, China.MethodA total of 2586 women were distributed across 4 prepregnancy categories according to the Chinese classification of body mass index, and to 4 end‐of‐pregnancy categories according to median weekly gestational weight gain.ResultsThe risks for gestational hypertension, pre‐eclampsia, gestational diabetes, and preterm premature rupture of membranes were higher for those who were overweight or obese before becoming pregnant (P < 0.05). Moreover, a gestational weight gain of 0.50 kg per week or greater was associated with a higher risk for gestational hypertension, preterm premature rupture of membranes, and fetal macrosomia (P < 0.05). Women in the highest quartile for weight gain (≥ 0.59 kg per week) were at higher risk for pre‐eclampsia (P < 0.05).ConclusionA high prepregnancy body mass index and excessive gestational weight gain were associated with increased risks for adverse pregnancy outcomes.
Effects of defoliation on grain yield and water use of winter wheat
Authors: SHAO L. , ZHANG X. , HIDEKI A. , TSUJI W. , CHEN S. 
Published: December 2009

SUMMARYField and pot experiments were conducted to investigate the effects of defoliation on crop performance and the possibility of using defoliation as a method for conserving soil moisture. The study was conducted during 2006–2008, over two growing seasons of winter wheat (Triticum aestivumL.) in the North China Plain. Three levels of defoliation (mild, moderate and severe) were imposed on winter wheat in the field during the following crop phases and conditions: at heading, at anthesis under water deficit conditions and at anthesis under two or three levels of irrigation. Additional pot experiments with three levels of defoliation under two water regimes were arranged. The results showed that both the intensity of defoliation and the timing of defoliation significantly reduced grain production. Under wet conditions the reduction was over 20%, while under dry conditions the reduction wasc. 12%. Yield reduction was greater for defoliation at heading than at anthesis and it was mainly caused by a reduction in kernel weight. Mild defoliation (top three leaves retained) did not affect grain yield. Moderate defoliation (top two leaves retained) slightly reduced grain production. Root length density in the topsoil profile was significantly reduced by severe defoliation at anthesis under wet conditions, but it increased under dry conditions. Dry matter remobilization to grains under moderate and mild defoliation was increased and resulted in a relatively higher harvest index (HI). The photosynthetic rate of the leaves remaining after defoliation was enhanced under all soil moisture conditions. Although defoliation reduced the seasonal water use (ET), the yield reduction was much greater than the reduction in ET under severe defoliation, resulting in lower water use efficiency (WUE). The results show that conserving soil moisture by removing leaves might not be an economic choice. Under the conditions of the present study, the WUE of winter wheat was not improved by defoliation; however, in very dry conditions the reduction in ET by defoliation might help the crop survive.
Temperamental and acute symptoms of borderline personality disorder: associations with normal personality traits and dynamic relations over time
Authors: Hopwood C. J. , Donnellan M. B. , Zanarini M. C. 
Published: December 2009

BackgroundRecent research suggests the utility of distinguishing temperamental and acute symptoms of borderline personality disorder (BPD). Temperamental symptoms, such as chronic anger and odd thinking, remit relatively slowly and have been hypothesized to reflect a hyperbolic predisposition to emotional pain and negativistic cognitions, whereas acute symptoms, such as substance abuse and chaotic relationships, remit relatively quickly and have been hypothesized to represent the consequences of maladaptations to triggering environmental events.MethodThe relationships of temperamental and acute BPD symptoms with normal personality traits and stability and dynamic associations over time across these symptom sets were tested in a 10-year longitudinal study of 362 patients with personality disorders.ResultsTemperamental symptoms were associated with high neuroticism, whereas acute symptoms were associated with low agreeableness. These symptoms had similar rank-order stabilities and relative changes in symptom sets were reciprocally linked in a cross-lagged path model suggesting dynamic associations between temperamental and acute symptoms over time.ConclusionsThe distinction between temperamental and acute BPD symptoms is supported by differential relations of these symptom sets to normal personality traits. Moreover, these symptoms appear to be linked in a mutually reinforcing dynamic over time. This distinction should be kept in mind in future studies of the aetiology of BPD and in diagnostic and treatment considerations.
Childhood adversity, adult stressful life events, and risk of past-year psychiatric disorder: a test of the stress sensitization hypothesis in a population-based sample of adults
Authors: McLaughlin K. A. , Conron K. J. , Koenen K. C. , Gilman S. E. 
Published: December 2009

BackgroundChildhood adversity (CA) is associated with adult mental disorders, but the mechanisms underlying this association remain inadequately understood. Stress sensitization, whereby CA increases vulnerability to mental disorders following adult stressful life events, has been proposed as a potential mechanism. We provide a test of the stress sensitization hypothesis in a national sample.MethodWe investigated whether the association between past-year stressful life events and the 12-month prevalence of major depression, post-traumatic stress disorder (PTSD), other anxiety disorders, and perceived stress varies according to exposure to CA. We used data from the National Epidemiological Survey of Alcohol and Related Conditions (NESARC) (n=34 653).ResultsPast-year stressful life events were associated with an increased risk of major depression, PTSD, anxiety disorders, and perceived stress. However, the magnitude of the increased risk varied according to respondents' history of CA. For example, past-year major stressors were associated with a 27.3% increase in the 12-month risk of depression among individuals with ⩾3 CAs and a 14.8% increased risk among individuals without CAs. Stress sensitization effects were present for depression, PTSD, and other anxiety disorders in women and men, although gender differences were found in the threshold of past-year stress needed to trigger such effects. Stress sensitization was most evident among individuals with ⩾3 CAs.ConclusionsCA is associated with increased vulnerability to the deleterious mental health effects of adult stressors in both men and women. High levels of CA may represent a general diathesis for multiple types of psychopathology that persists throughout the life course.
The Envisioning of Cells
Authors: Parnes Ohad 
Published: December 2009

The ArgumentMicroscopical consideration played a crucial role in German physiology in the period of, grosso modo, 1780–1830. Specifically, a conception of material change was established, according to which all life is grounded in the process of the generation of microscopical forms out of an amorphous, primitive generative substance. Embryological development, tissue growth, and the generation of microorganisms were all considered to be the manifestation of this fundamental developmental process. In contrast to the common historiography, I try to understand Theodor Schwann's 1838 discovery of the cell theory in terms of the epistemological categories he applied to the prevailing conceptions of life and living matter. I argue that Schwann was able to discern cells not because of any superior microscopical methods, but rather as part of his wider investigative endeavor to explicate life processes according to specific causal agents. I argue that Schwann was able to demonstrate the existence of cells only when he considered animal tissues in terms of a causal relation between specific material agents and their effect, that is, the developmental history of tissue.
Wonders, Logic, and Microscopy in the Eighteenth Century: A History of the Rotifer
Authors: Ratcliff M. J. 
Published: December 2009

The ArgumentContrary to the dominant historiography of microscopy, which tends to maintain that there was no microscopical program in the Enlightenment, this paper argues that there was such a program and attempts to illustrate one aspect of its dynamic character. The experiments, observations, and interpretations on rotifers and their management by scholars of that period show that there did exist a precise axis of research that can be followed historically. Indeed, the various controversies these scholars engaged in imply that they performed accurate microscopical experiments and observations and also carefully interpreted their visual data. Furthermore, the kinds of phenomena presented by the rotifer and other microscopic entities, such as their morphology or their revival from desiccation, helped to improve methodology on the use of the microscope. The paper also argues that this sort of inquiry is not fundamentally different from other research in the natural sciences of the eighteenth century.
Surveillance for outbreaks of influenza-like illness in the institutionalized elderly
Authors: ROSEWELL A. , CHIU C. , LINDLEY R. , DWYER D. E. , MOFFATT C. R. M. , SHINEBERG C. , CLARKE E. , BOOY R. , MacINTYRE C. R. 
Published: December 2009

SUMMARYRespiratory outbreaks are common in aged-care facilities (ACFs), are both underreported and frequently identified late, and are often associated with considerable burden of illness and death. There is emerging evidence that active surveillance coupled with early and systematic intervention can reduce this burden. Active surveillance for influenza-like illness and rapid diagnosis of influenza were established in 16 ACFs in Sydney, Australia, prior to the winter of 2006. A point-of-care influenza test and laboratory direct immunofluorescence tests for common respiratory viruses were used for diagnosis. We achieved early identification of seven respiratory disease outbreaks, two of which were caused by influenza. For the influenza outbreaks, antiviral treatment and prophylaxis were initiated 4–6 days from symptom onset in the primary case. A simple active surveillance system for influenza was successfully implemented and resulted in early detection of influenza and other respiratory disease outbreaks. This enabled earlier implementation of prevention and control measures and increased the potential effectiveness of anti-influenza chemoprophylaxis.