bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparison of digital radiography systems in terms of effective detective quantum efficiency
Authors: Bertolini Marco , Nitrosi Andrea , Rivetti Stefano , Lanconelli Nico , Pattacini Pierpaolo , Ginocchi Vladimiro , Iori Mauro 
Published: April 2012

Purpose:The purpose of this study is to compare digital radiography systems using the metric effective detective quantum efficiency (eDQE), which better reflects digital radiography imaging system performance under clinical operating conditions, in comparison with conventional metrics such as modulation transfer function (MTF), normalized noise power spectra (NNPS), and detective quantum efficiency (DQE).Methods:The eDQE was computed by the calculation of the MTF, the NNPS, the phantom attenuation and scatter, and estimation of x‐ray flux. The physical characterization of the systems was obtained with the standard beam conditions RQA5 and RQA9, using the PA Chest phantom proposed by AAPM Report # 31 simulating the attenuation and scatter characteristics of the adult human thorax. The MTF (eMTF) was measured by using an edge test placed at the frontal surface of the phantom, the NNPS (eNNPS) was calculated from images of the phantom acquired at three different exposure levels covering the operating range of the system (E0, which is the exposure at which a system is normally operated, 1/3 E0, and 3 E0), and scatter measurements were assessed by using a beam‐stop technique. The integral of DQE (IDQE) and eDQE (IeDQE) was calculated over the whole spatial frequency range.Results:The eMTF results demonstrate degradation due to magnification and the presence of scattered radiation. The eNNPS was influenced by the grid presence, and in some systems, it contained structured noise. At typical clinical exposure levels, the magnitude of eDQE(0) with respect to DQE(0) at RQA9 beam conditions was 13%, 17%, 16%, 36%, and 24%, respectively, for Carestream DRX‐1, Carestream DRX‐1C, Carestream Direct View CR975, Philips Digital Diagnost VM, and GE Revolution XR/d. These results were confirmed by the ratio of IeDQE and IDQE in the same conditions.Conclusions:The authors confirm the robustness and reproducibility of the eDQE method. As expected, the DR systems performed better than the CR systems due to their superior signal‐to‐noise transfer characteristics. The results of this study suggest the eDQE method may provide an opportunity to more accurately assess the clinical performance of digital radiographic imaging systems by accounting for factors such as the presence of scatter, use of an antiscatter grid, and magnification and focal spot blurring effects, which are not reflected in conventional DQE measures.
Effect of body mass index and physical exercise on risk of knee and hip osteoarthritis: longitudinal data from the Norwegian HUNT Study
Authors: Mork Paul Jarle , Holtermann Andreas , Nilsen Tom Ivar Lund 
Published: April 2012

BackgroundMechanical joint stress imposed by high body mass index (BMI) is associated with increased risk of knee and hip osteoarthritis. This prospective study investigated the independent and joint association of BMI and physical exercise on risk of knee and hip osteoarthritis.MethodsThe study includes 15 191 women and 14 766 men in the Norwegian HUNT Study without pain or physical impairment at baseline. Occurrence of self-reported physician-diagnosed osteoarthritis was assessed at 11 years of follow-up.ResultsBMI was positively related to risk of knee osteoarthritis (Ptrend<0.001), with an RR of 4.37 (95% CI 3.01 to 6.33) in women and 2.78 (95% CI 1.59 to 4.84) in men, comparing obese and normal weight persons. No clear association was observed for hip osteoarthritis. Obesity increased the risk of severe activity-limiting osteoarthritis, with an RR of 2.30 (95% CI 1.68 to 3.15) and 2.50 (95% CI 1.56 to 4.03) in women and men, respectively. Physical exercise did not modify the above associations (Pinteraction>0.34). Exercise intensity was not associated with risk of osteoarthritis in any BMI category; that is, obese persons reporting high-intensity exercise had an RR of 1.28 (95% CI 0.59 to 2.79) for severe osteoarthritis compared with inactive persons.ConclusionHigh BMI increases the risk of knee osteoarthritis and severe osteoarthritis. Physical exercise does not increase the risk of osteoarthritis at any level of BMI, suggesting that exercise could be encouraged also among individuals with excessive body mass, without concern for an increased risk of osteoarthritis.
Beneficiaries With Cardiovascular Disease and the Part D Coverage Gap
Authors: Polinski Jennifer M. , Shrank William H. , Glynn Robert J. , Huskamp Haiden A. , Roebuck M. Christopher , Schneeweiss Sebastian 
Published: April 2012

Background—
Medicare Part D improved access to cardiovascular medications. Increased cardiovascular drug use and resulting health improvements could be derailed when beneficiaries enter the coverage gap and must pay 100% of drug costs. The coverage gap remains the subject of Congressional debate; evidence regarding its impact on cardiovascular drug use and health outcomes is needed.

Methods and Results—
We followed 122 255 Medicare beneficiaries with cardiovascular conditions with linked prescription and medical claims who reached the coverage gap spending threshold in 2006 or 2007. Beneficiaries entered the study on reaching the threshold and were followed until an event, the catastrophic coverage spending threshold, or year's end. We matched 3980 beneficiaries who reached the threshold and received no financial assistance (exposed) to 3980 with financial assistance during the gap period (unexposed), using propensity score and high-dimensional propensity score approaches. We compared rates of cardiovascular drug discontinuation, drug switching, and death or hospitalization for acute coronary syndrome (ACS) plus revascularization, congestive heart failure, or atrial fibrillation. In propensity score-matched analyses, exposed beneficiaries were more likely to discontinue (hazard ratio, 1.57; 95% confidence interval, 1.39 to 1.79; risk difference,13.76; 95% confidence interval, 10.99 to 16.54 drugs/100 person-years) but no more or less likely to switch cardiovascular drugs. There were no significant differences in rates of death (propensity score-matched hazard ratio,1.23; 95% confidence interval, 0.89 to 1.71) or other outcomes.

Conclusions—
Part D beneficiaries with cardiovascular conditions with no financial assistance during the coverage gap were at increased risk for cardiovascular drug discontinuation; however, the impact of this difference on health outcomes is not clear.
Association of Fetuin-A With Incident Diabetes Mellitus in Community-Living Older Adults
Authors: Ix Joachim H. , Biggs Mary L. , Mukamal Kenneth J. , Kizer Jorge R. , Zieman Susan J. , Siscovick David S. , Mozaffarian Dariush , Jensen Majken K. , Nelson Lauren , Ruderman Neil , Djousse Luc 
Published: April 2012

Background—
The liver-secreted protein fetuin-A induces peripheral insulin resistance in vitro. In a pilot study, we observed that higher fetuin-A levels were associated with diabetes mellitus in older persons. However, this finding has not been confirmed in large cohorts. We sought to confirm the association of fetuin-A with incident diabetes mellitus in older persons and to determine whether the association differs by age, sex, and race and among persons with cardiovascular disease (CVD).

Methods and Results—

Among 3710 community-living individuals ≥65 years of age without diabetes mellitus at baseline, fetuin-A was measured in serum collected in 1992 to 1993. Participants were followed up for 10.6 years (median) for incident diabetes mellitus. Cox regression models evaluated the association of fetuin-A with incident diabetes mellitus. Interaction terms evaluated heterogeneity by age, sex, race, and CVD. Mean age was 75 years; 60 were female; 15 were black; and 16 had CVD. Mean fetuin-A concentrations were 0.47±0.10 g/L. During follow-up, 305 incident diabetes cases occurred. Each 0.10-g/L (SD)-greater fetuin-A was associated with 19 higher risk of diabetes mellitus (hazard ratio, 1.19; 95 confidence interval, 1.06–1.33) after adjustment for demographics, lifestyle factors, albumin, kidney function, and CVD. Further adjustment for potential mediators (body mass index, waist circumference, hypertension, lipids, and C-reactive protein) moderately attenuated the association (hazard ratio, 1.13; 95 confidence interval, 1.00–1.28). Results were similar by sex, race, and CVD status but were stronger in persons <75 years old (
P
for interaction=0.01).

Conclusions—
Higher fetuin-A is associated with incident diabetes mellitus in older persons regardless of sex, race, or prevalent CVD status. The association may be attenuated in those ≥75 years of age.
Mean and Variability of the Tropical Atlantic Ocean in the CCSM4*
Authors: Muñoz Ernesto , Weijer Wilbert , Grodsky Semyon A. , Bates Susan C. , Wainer Ilana 
Published: April 2012

Abstract
This study analyzes important aspects of the tropical Atlantic Ocean from simulations of the fourth version of the Community Climate System Model (CCSM4): the mean sea surface temperature (SST) and wind stress, the Atlantic warm pools, the principal modes of SST variability, and the heat budget in the Benguela region. The main goal was to assess the similarities and differences between the CCSM4 simulations and observations. The results indicate that the tropical Atlantic overall is realistic in CCSM4. However, there are still significant biases in the CCSM4 Atlantic SSTs, with a colder tropical North Atlantic and a hotter tropical South Atlantic, that are related to biases in the wind stress. These are also reflected in the Atlantic warm pools in April and September, with its volume greater than in observations in April and smaller than in observations in September. The variability of SSTs in the tropical Atlantic is well represented in CCSM4. However, in the equatorial and tropical South Atlantic regions, CCSM4 has two distinct modes of variability, in contrast to observed behavior. A model heat budget analysis of the Benguela region indicates that the variability of the upper-ocean temperature is dominated by vertical advection, followed by meridional advection.
Testing of the Tropically Excited Arctic Warming Mechanism (TEAM) with Traditional El Niño and La Niña
Authors: Lee Sukyoung 
Published: April 2012

AbstractBy analyzing El Niño and La Niña composites with 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) data, evidence is presented here that the surface air temperature of the Arctic winter (December–February) is anomalously warm during La Niña and cold during El Niño. Surface and top-of-the-atmosphere energy fluxes were used to calculate the composite zonal-mean poleward moist static energy transport. The result shows that the La Niña warming in the Arctic is associated with an increased poleward energy transport in the extratropics. The opposite characteristics are found for El Niño. Because the total tropical convective heating is more localized during La Niña than El Niño, these findings suggest that the Arctic surface air temperature anomalies associated with ENSO may be attributed to the tropically excited Arctic warming mechanism (TEAM). In the tropics, consistent with previous studies, the anomalous poleward energy transport is positive during El Niño and negative during La Niña. Given the debate over whether a warmer world would take on more El Niño–like or La Niña–like characteristics, the findings of this study underscore the need for further investigation of tropical influence on polar climate.
Singaporean adolescents’ perceptions of violence: Implications for practice
Authors: Nair Sudha , Osman Mohammad Maliki 
Published: April 2012

Culture, religion and ethnicity appear to impact how adolescents view their experiences of interpersonal violence. Despite the fact that these adolescents were third and fourth generation Singaporeans of Chinese, Indian and Malay descent, this qualitative study showed that while they did not condone the violence; their acceptance of it was largely governed by their interpretation of the scriptures, their ability to externalize control and responsibility to an external source like ‘God’ or ‘fate’, and the intergenerational transmission of culture in which they were socialized. A convenience sampling method was chosen to interview 52 adolescents who had grown up exposed to interpersonal violence. The study’s objective was to determine whether culture, religion and ethnicity influenced their understanding of the perpetration of interpersonal violence. It answered the research question: What meanings do adolescents give to their life experiences in relation to growing up exposed to interpersonal violence? With increasing globalization and the cultural diversity in our societies, social workers must be ethnically and culturally sensitive to the worldviews of adolescents from differing backgrounds, if they are to engage them successfully. From a policy perspective, gender education which includes issues of equality and respect needs to be consciously developed in the school’s curricula. Early outreach programmes are critical to identify these young victims of abuse before shame and loyalty issues in adolescence set in.
Impact of Alternative Coding Schemes on Incidence Rates of Key Complications After Total Hip Arthroplasty
Authors: Cram Peter , Ibrahim Said A. , Lu Xin , Wolf Brian R. 
Published: April 2012

Background: Administrative data are commonly used to examine orthopedic outcomes including total hip arthroplasty (THA), but little is known about how minor analytic decisions impact results. Our objective was to examine how the rates of 3 adverse outcomes (deep vein thrombosis [DVT], pulmonary embolism [PE], and hemorrhage) varied with subtle adjustments to our analytic method.Methods: We used Medicare Part A data to identify all beneficiaries who underwent primary or revision THA during 2007 to 2008. We used 2 published algorithms (Katz/Cram and Patient Safety Indicators [PSIs]) to identify cases of DVT, PE, and hemorrhage occurring at 3 different points in time; index admission; 30-day readmission; and index admission plus readmission. We used the kappa statistic to compare the agreement between methods. We examined variation in complication rates across hospitals using regression models that adjusted for differences in patient demographics and comorbidity. Results: Among 202 773 primary and 40 973 revision THA patients, the agreement between the Katz/Cram and PSI methods was excellent for DVT and PE at all time points (kappa 0.95-1.0) but poor for hemorrhage (kappa 0.07-0.29). The incidence of DVT during the index admission among the primary THA cohort was 0.40% using the Katz/Cram method and 0.37% using the PSI method. The incidence of hemorrhage during the index admission among the primary THA cohort was 1.29% using the Katz/Cram method and 0.05% using the PSI method. We found significant variation in hospital rates of all 3 complications (DVT, PE, and hemorrhage). For example, the mean rate of hemorrhage at index admission or readmission for revision THA was 5.7% (standard deviation: 12.8%); we found 137 hospitals with hemorrhage rates of 25% or higher among their revision THA patients. Discussion: We found important differences in the rates of THA complications depending upon the coding algorithms and time frame employed. Our results suggest that administrative data can be used to evaluate THA complications but that methodology should be carefully considered.
Osteopontin is a prognostic factor for survival of acute myeloid leukemia patients
Authors: Liersch Ruediger , Gerss Joachim , Schliemann Christoph , Bayer Michael , Schwöppe Christian , Biermann Christoph , Appelmann Iris , Kessler Torsten , Löwenberg Bob , Büchner Thomas , Hiddemann Wolfgang , Müller-Tidow Carsten , Berdel Wolfgang E. , Mesters Rolf 
Published: April 2012

Abstract
Osteopontin (OPN) is a glycoprotein that is secreted by osteoblasts and hematopoietic cells. OPN suppresses the proliferation of hematopoietic stem cells in vitro and may regulate the hematopoietic stem cell pool. Increased serum OPN concentrations occur in chronic myeloid leukemia, multiple myeloma, and acute myeloid leukemia (AML). In the present study, we analyzed the prognostic impact of OPN in AML by investigating the expression and relevance of OPN in newly diagnosed AML patients from 2 large study groups (the German AML Cooperative Group and the Dutch-Belgian Hematology Oncology Cooperative group). IHC (n = 84), ELISAs of blood/BM sera (n = 41), and microarray data for mRNA levels (n = 261) were performed. Expression of OPN protein was increased in AML patients both in BM blasts (IHC) and in BM serum (ELISA) compared with healthy controls. Patients expressing high levels of OPN within the BM (IHC) experienced shortened overall survival (OS; P = .025). Multivariate analysis identified karyotype, blast clearance (day 16), and the level of OPN expression as independent prognostic factors for OS. This prompted us to analyze microarray data from 261 patients from a third cohort. The analysis confirmed OPN as a prognostic marker. In summary, high OPN mRNA expression indicated decreased event-free survival (P = .0002) and OS (P = .001). The prognostic role of OPN was most prominent in intermediate-risk AML. These data provide evidence that OPN expression is an independent prognostic factor in AML.
High prevalence of antibiotic resistance in commensal Escherichia coli among children in rural Vietnam
Authors: Dyar Oliver James , Hoa Nguyen Quynh , Trung Nguyen V , Phuc Ho D , Larsson Mattias , Chuc Nguyen TK , Lundborg Cecilia Stålsby 
Published: April 2012

Abstract

Background
Commensal bacteria represent an important reservoir of antibiotic resistance genes. Few community-based studies of antibiotic resistance in commensal bacteria have been conducted in Southeast Asia. We investigated the prevalence of resistance in commensal Escherichia coli in preschool children in rural Vietnam, and factors associated with carriage of resistant bacteria.

Methods
We tested isolates of E. coli from faecal samples of 818 children aged 6-60 months living in FilaBavi, a demographic surveillance site near Hanoi. Daily antibiotic use data was collected for participating children for three weeks prior to sampling and analysed with socioeconomic and demographic characteristics extracted from FilaBavi's re-census survey 2007. Descriptive statistics were generated, and a logistic regression model was used to identify contributions of the examined factors.

Results
High prevalences of resistance were found to tetracycline (74%), co-trimoxazole (68%), ampicillin (65%), chloramphenicol (40%), and nalidixic acid (27%). Two isolates were resistant to ciprofloxacin. Sixty percent of isolates were resistant to three or more antibiotics. Recent sulphonamide use was associated with co-trimoxazole resistance [OR 3.2, 95% CI 1.8-5.7], and beta-lactam use with ampicillin resistance [OR 1.8, 95% CI 1.3-2.4]. Isolates from children aged 6-23 months were more likely to be resistant to ampicillin [OR 1.8, 95% CI 1.3-2.4] and co-trimoxazole [OR 1.5, 95% CI 1.1-2.0]. Associations were identified between geographical areas and tetracycline and ampicillin resistance.

Conclusions
We present high prevalence of carriage of commensal E. coli resistant to commonly used antibiotics. The identified associations with recent antibiotic use, age, and geographical location might contribute to our understanding of carriage of antibiotic resistant commensal bacteria.
Seroprevalence of avian influenza A (H5N1) virus among poultry workers in Jiangsu Province, China: an observational study
Authors: Huo Xiang , Zu Rongqiang , Qi Xian , Qin Yuanfang , Li Liang , Tang Fenyang , Hu Zhibin , Zhu Fengcai 
Published: April 2012

Abstract

Background
Since 2003 to 06 Jan 2012, the number of laboratory confirmed human cases of infection with avian influenza in China was 41 and 27 were fatal. However, the official estimate of the H5N1 case-fatality rate has been described by some as an over estimation since there may be numerous undetected asymptomatic/mild cases of H5N1 infection. This study was conducted to better understand the real infection rate and evaluate the potential risk factors for the zoonotic spread of H5N1 viruses to humans.

Methods
A seroepidemiological survey was conducted in poultry workers, a group expected to have the highest level of exposure to H5N1-infected birds, from 3 counties with habitat lakes of wildfowl in Jiangsu province, China. Serum specimens were collected from 306 participants for H5N1 serological test. All participants were interviewed to collect information about poultry exposures.

Results
The overall seropositive rate was 2.61% for H5N1 antibodies. The poultry number was found associated with a 2.39-fold significantly increased subclinical infection risk after adjusted with age and gender.

Conclusions
Avian-to -human transmission of avian H5N1 virus remained low. Workers associated with raising larger poultry flocks have a higher risk on seroconversion.
New insights into Escherichia coli metabolism: carbon scavenging, acetate metabolism and carbon recycling responses during growth on glycerol
Authors: Martínez-Gómez Karla , Flores Noemí , Castañeda Héctor M , Martínez-Batallar Gabriel , Hernández-Chávez Georgina , Ramírez Octavio T , Gosset Guillermo , Encarnación Sergio , Bolivar Francisco 
Published: April 2012

Abstract

Background
Glycerol has enhanced its biotechnological importance since it is a byproduct of biodiesel synthesis. A study of Escherichia coli physiology during growth on glycerol was performed combining transcriptional-proteomic analysis as well as kinetic and stoichiometric evaluations in the strain JM101 and certain derivatives with important inactivated genes.

Results
Transcriptional and proteomic analysis of metabolic central genes of strain JM101 growing on glycerol, revealed important changes not only in the synthesis of MglB, LamB and MalE proteins, but also in the overexpression of carbon scavenging genes: lamB, malE, mglB, mglC, galP and glk and some members of the RpoS regulon (pfkA, pfkB, fbaA, fbaB, pgi, poxB, acs, actP and acnA). Inactivation of rpoS had an important effect on stoichiometric parameters and growth adaptation on glycerol. The observed overexpression of poxB, pta, acs genes, glyoxylate shunt genes (aceA, aceB, glcB and glcC) and actP, suggested a possible carbon flux deviation into the PoxB, Acs and glyoxylate shunt. In this scenario acetate synthesized from pyruvate with PoxB was apparently reutilized via Acs and the glyoxylate shunt enzymes. In agreement, no acetate was detected when growing on glycerol, this strain was also capable of glycerol and acetate coutilization when growing in mineral media and derivatives carrying inactivated poxB or pckA genes, accumulated acetate. Tryptophanase A (TnaA) was synthesized at high levels and indole was produced by this enzyme, in strain JM101 growing on glycerol. Additionally, in the isogenic derivative with the inactivated tnaA gene, no indole was detected and acetate and lactate were accumulated. A high efficiency aromatic compounds production capability was detected in JM101 carrying pJLBaroG

fbr

tktA, when growing on glycerol, as compared to glucose.

Conclusions
The overexpression of several carbon scavenging, acetate metabolism genes and the absence of acetate accumulation occurred in JM101 cultures growing on glycerol. To explain these results it is proposed that in addition to the glycolytic metabolism, a gluconeogenic carbon recycling process that involves acetate is occurring simultaneously in this strain when growing on glycerol. Carbon flux from glycerol can be efficiently redirected in JM101 strain into the aromatic pathway using appropriate tools.