bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hepatitis B Vaccination Coverage Levels Among Healthcare Workers in the United States, 2002-2003
Authors: Simard Edgar P. , Miller Jeremy T. , George Prethibha A. , Wasley Annemarie , Alter Miriam J. , Bell Beth P. , Finelli Lyn 
Published: June 2007

Background.Hepatitis B virus (HBV) infection is a well recognized risk for healthcare workers (HCWs), and routine vaccination of HCWs has been recommended since 1982. By 1995, the level of vaccination coverage among HCWs was only 67%.Objective.To obtain an accurate estimate of hepatitis B vaccination coverage levels among HCWs and to describe the hospital characteristics and hepatitis B vaccination policies associated with various coverage levels.Design.Cross-sectional survey.Methods.A representative sample of 425 of 6,116 American Hospital Association member hospitals was selected to participate, using probability-proportional-to-size methods during 2002-2003. The data collected included information regarding each hospital's hepatitis B vaccination policies. Vaccination coverage levels were estimated from a systematic sample of 25 HCWs from each hospital whose medical records were reviewed for demographic and vaccination data. The main outcome measure was hepatitis B vaccination coverage levels.Results.Among at-risk HCWs, 75% had received 3 or more doses of the hepatitis B vaccine, corresponding to an estimated 2.5 million vaccinated hospital-based HCWs. The coverage level was 81% among staff physicians and nurses. Compared with nurses, coverage was significantly lower among phlebotomists (71.1%) and nurses' aides and/or other patient care staff (70.9%; P < .05). Hepatitis B vaccination coverage was highest among white HCWs (79.5%) and lowest among black HCWs (67.6%; P < .05). Compared with HCWs who worked in hospitals that required vaccination only of HCWs with identified risk for exposure to blood or other potentially infectious material, hepatitis B vaccination coverage was significantly lower among HCWs who worked in hospitals that required vaccination of HCWs without identified risk for exposure to blood or other potentially infectious material (76.6% vs 62.4%; P < .05).Conclusions.In the United States, an estimated 75% of HCWs have been vaccinated against hepatitis B. Important differences in coverage levels exist among various demographic groups. Hospitals need to identify methods to improve hepatitis B vaccination coverage levels and should consider developing targeted vaccination programs directed at unvaccinated, at-risk HCWs who have frequent or potential exposure to blood or other potentially infectious material.
Role of Environmental Surveillance in Determining the Risk of Hospital-Acquired Legionellosis: A National Surveillance Study With Clinical Correlations
Authors: Stout Janet E. , Muder Robert R. , Mietzner Sue , Wagener Marilyn M. , Perri Mary Beth , DeRoos Kathleen , Goodrich Dona , Arnold William , Williamson Theresa , Ruark Ola , Treadway Christine , Eckstein Elizabeth C. , Marshall Debra , Rafferty Mary Ellen , Sarro Kathleen , Page Joann , Jenkins Robert , Oda Gina , Shimoda Kathleen J. , Zervos Marcus J. , Bittner Marvin , Camhi Sharon L. , Panwalker Anand P. , Donskey Curtis J. , Nguyen Minh-Hong , Holodniy Mark , Yu Victor L. ,   Legionella Study Group
Published: June 2007

Objective.Hospital-acquired Legionella pneumonia has a fatality rate of 28%, and the source is the water distribution system. Two prevention strategies have been advocated. One approach to prevention is clinical surveillance for disease without routine environmental monitoring. Another approach recommends environmental monitoring even in the absence of known cases of Legionella pneumonia. We determined the Legionella colonization status of water systems in hospitals to establish whether the results of environmental surveillance correlated with discovery of disease. None of these hospitals had previously experienced endemic hospital-acquired Legionella pneumonia.Design.Cohort study.Setting.Twenty US hospitals in 13 states.Interventions.Hospitals performed clinical and environmental surveillance for Legionella from 2000 through 2002. All specimens were shipped to the Special Pathogens Laboratory at the Veterans Affairs Pittsburgh Medical Center.Results.Legionella pneumophila and Legionella anisa were isolated from 14 (70%) of 20 hospital water systems. Of 676 environmental samples, 198 (29%) were positive for Legionella species. High-level colonization of the water system (30% or more of the distal outlets were positive for L. pneumophila) was demonstrated for 6 (43%) of the 14 hospitals with positive findings. L. pneumophila serogroup 1 was detected in 5 of these 6 hospitals, whereas 1 hospital was colonized with L. pneumophila serogroup 5. A total of 633 patients were evaluated for Legionella pneumonia from 12 (60%) of the 20 hospitals: 377 by urinary antigen testing and 577 by sputum culture. Hospital-acquired Legionella pneumonia was identified in 4 hospitals, all of which were hospitals with L. pneumophila serogroup 1 found in 30% or more of the distal outlets. No cases of disease due to other serogroups or species (L. anisa) were identified.Conclusion.Environmental monitoring followed by clinical surveillance was successful in uncovering previously unrecognized cases of hospital-acquired Legionella pneumonia.
Parity, pregnancy and neonatal outcomes in women treated for hyperprolactinaemia compared with a control group
Authors: Berinder Katarina , Hulting Anna‐Lena , Granath Fredrik , Hirschberg Angelica Lindén , Akre Olof 
Published: June 2007

SummaryObjective  Infertility is a common problem in women with hyperprolactinaemia. There are limited data on the fertility and pregnancy course among these women. The objective was to study parity, pregnancy and neonatal outcomes in women with hyperprolactinaemia as compared with a control group.Design  Register study.Patients  Two hundred and seventy‐one female patients treated for primary hyperprolactinaemia were identified in the hospital record archives between 1974 and 2002. For each patient four comparison subjects, matched by sex, birth year and county of residence were identified in the Register of Population. Data were retrieved from the Swedish medical birth register and were analysed using logistic regression and analysis of variance.Measurements  Parity, maternal age at first delivery, weeks of gestation, induction of labour, caesarean delivery, multiple birth, Apgar score, birth weight, length, sex, congenital malformations, neonatal care.Results  One hundred and sixty‐two deliveries in the hyperprolactinaemia group and 1220 deliveries in the control group were analysed. Patients with hyperprolactinaemia were significantly older at their first pregnancy than their controls: 29·0 (± 4·4) and 27·2 (± 4·8) years, respectively (P = 0·0002). Furthermore, parity was inversely associated with hyperprolactinaemia status (P for trend = 0·0009). The odds of having three or more children were threefold lower among the patients (OR 0·31 (95% CI 0·16, 0·60)). There were no differences between patients and controls with respect to pregnancy complications, delivery or neonatal outcome variables.Conclusions  We found no evidence of increased risk of pregnancy complications or adverse pregnancy outcomes in women with treated hyperprolactinaemia. However, the patients were older at their first pregnancy and had a reduced overall parity.
Proportion of type 1 and type 2 amiodarone‐induced thyrotoxicosis has changed over a 27‐year period in Italy
Authors: Bogazzi Fausto , Bartalena Luigi , Dell’Unto Enrica , Tomisti Luca , Rossi Giuseppe , Pepe Pasquale , Tanda Maria Laura , Grasso Lucia , Macchia Enrico , Aghini‐Lombardi Fabrizio , Pinchera Aldo , Martino Enio 
Published: June 2007

SummaryContext  Two main forms of amiodarone‐induced thyrotoxicosis (AIT) exist. Type 1 AIT is a form of iodine‐induced hyperthyroidism. Its management is complex and includes thionamides, potassium perchlorate and, occasionally, thyroidectomy. Type 2 AIT is a destructive thyroiditis, responds to glucocorticoids, and usually does not require further thyroid treatment once euthyroidism has been restored.Objective  To assess retrospectively the prevalence and relative proportion of type 1 and type 2 AIT over a 27‐year period at a tertiary referral centre in Italy.Patients  Consecutive AIT patients (n = 215) seen at the department of endocrinology of the University of Pisa between 1980 and 2006.Results  Type 1 AIT constituted the most frequent AIT form (60%) during the first years covered by this study. The annual mean number of type 1 AIT patients was 3·6 at the beginning of the study period, and 2·5 during the later years. In contrast, the mean annual number of new cases of type 2 AIT progressively increased from 2·4 to 12·5. Likewise, the proportion of type 2 AIT increased in a significant linear manner (P < 0·0001), currently accounting for 89% of AIT cases. Type 2 AIT patients showed a male preponderance, higher serum FT4/FT3 ratio (P < 0·002), lower 3‐h and 24‐h thyroidal radioactive iodine uptake values (P < 0·0001), and received a higher cumulative dose of amiodarone (P < 0·0001) than type 1 AIT patients.Conclusions  Over a 27‐year period, the epidemiology of AIT changed, as the prevalence of type 2 AIT progressively increased and that of type 1 remained constant. Thus, under most circumstances, endocrinologists nowadays deal with type 2 AIT, which is a destructive thyroiditis, generally treated successfully with glucocorticoids. Although no additional treatment is usually required after the destructive process subsides, periodic assessment of thyroid function is warranted, because of the occurrence of hypothyroidism (up to 17%) during long‐term follow‐up of these patients.
Role of the endothelin axis in the proliferation of human thyroid cancer cells
Authors: Donckier Julian E. , Mertens‐Strijthagen Jeannine , Flamion Bruno 
Published: June 2007

SummaryObjective  Endothelin‐1 (ET‐1) may play a role in carcinogenesis. ET‐1 axis is overexpressed in thyroid carcinoma. We investigated the expression and the production of ET‐1 by thyroid cancer cells as well as the effect of ET‐1 receptor antagonism on cell proliferation.Design  Human papillary and follicular thyroid carcinoma cell lines were cultured.Measurements  (i) Prepro‐ET‐1, ET‐1 receptors (ETA R and ETB R) and ET‐1 converting enzyme (ECE) by reverse transcriptase polymerase chain reaction (RT‐PCR); (ii) the presence of ETA R by western blot; (iii) ET‐1 concentrations in medium by an enzyme immunometric assay; (iiii) the proliferation of cells by BrdU and tritiated thymidine incorporation.Results  RT‐PCR detected the presence of mRNA for prepro‐ET‐1, ETA R and ECE in papillary and follicular carcinoma cells. ETB R was only expressed by follicular cells. ETA R was also detected in both cell types by western blot. Measurements of ET‐1 concentrations demonstrated a secretion of active ET‐1 by the cells. ETA R antagonism with atrasentan reduced cell proliferation by 16% in papillary carcinoma cells (P < 0·05) and by 51% in follicular carcinoma cells (P < 0·001).Conclusions  Papillary and follicular carcinoma cells express all components of the ET‐1 axis. ETA R antagonism exerts antiproliferative effects, which opens up new therapeutic perspectives in thyroid carcinoma.
Modelling magnetic fields due to steel drum accumulations
Authors: Furness Peter 
Published: June 2007

ABSTRACTModelling the magnetic fields produced by accumulations of steel drums is a problem that is relevant to the detection and evaluation of disposal sites containing materials that are potentially hazardous to the environment. Accurate modelling is possible with existing integral equation techniques but these are numerically intensive due to the need to solve very large systems of linear equations. Use of an approximate iterative technique for the solution of the equations (system iteration) allows the integral equation technique to be extended to modelling the magnetic effect of substantially large accumulations, comprising up to several hundred drums, on very moderate computing facilities. However, even this process remains time‐consuming and suggests the use of more rapid, if less accurate, modifications. Several are available.Surprisingly, quite reasonable results can also be achieved with a very basic approximation that represents each drum by a discrete dipole located at its centroid. The dipole moments are found from the magnetic behaviour of single drums exposed to a uniform inducing field, which can be conveniently defined by a dyadic drum apparent susceptibility. The basic discrete dipole model for drum accumulations can be substantially improved by using a first‐order accommodation of the depolarizing effect produced by the shape of the accumulation.All of the above modelling techniques require details of individual drum locations and orientation. This information is generally unavailable to geophysical practitioners involved in environmental surveys and so prompts the idea of models that represent drum accumulations as a continuous distribution of magnetization. The convenience of neglecting details of drum location and orientation comes at the cost of some loss in accuracy of the modelled responses. However, for accumulations buried sufficiently deep and in which the drums are uniformly distributed, the total field magnetic anomaly is found to be reasonably approximated by the effect of a continuous magnetization, expressible in terms of an effective isotropic susceptibility. Again, the basic model can be improved by the accommodation of demagnetization effects due to the shape of the accumulation.
Towards a collaborative, global infrastructure for biodiversity assessment
Authors: Guralnick Robert P. , Hill Andrew W. , Lane Meredith 
Published: June 2007

AbstractBiodiversity data are rapidly becoming available over the Internet in common formats that promote sharing and exchange. Currently, these data are somewhat problematic, primarily with regard to geographic and taxonomic accuracy, for use in ecological research, natural resources management and conservation decision‐making. However, web‐based georeferencing tools that utilize best practices and gazetteer databases can be employed to improve geographic data. Taxonomic data quality can be improved through web‐enabled valid taxon names databases and services, as well as more efficient mechanisms to return systematic research results and taxonomic misidentification rates back to the biodiversity community. Both of these are under construction. A separate but related challenge will be developing web‐based visualization and analysis tools for tracking biodiversity change. Our aim was to discuss how such tools, combined with data of enhanced quality, will help transform today's portals to raw biodiversity data into nexuses of collaborative creation and sharing of biodiversity knowledge.
The underestimated importance of belowground carbon input for forest soil animal food webs
Authors: Pollierer Melanie M. , Langel Reinhard , Körner Christian , Maraun Mark , Scheu Stefan 
Published: June 2007

AbstractThe present study investigated the relative importance of leaf and root carbon input for soil invertebrates. Experimental plots were established at the Swiss Canopy Crane (SCC) site where the forest canopy was enriched with13C depleted CO2at a target CO2concentration ofc. 540 p.p.m. We exchanged litter between labelled and unlabelled areas resulting in four treatments: (i) leaf litter and roots labelled, (ii) only leaf litter labelled, (iii) only roots labelled and (iv) unlabelled controls. In plots with only13C‐labelled roots most of the soil invertebrates studied were significantly depleted in13C, e.g. earthworms, chilopods, gastropods, diplurans, collembolans, mites and isopods, indicating that these taxa predominantly obtain their carbon from belowground input. In plots with only13C‐labelled leaf litter only three taxa, including, e.g. juvenileGlomerisspp. (Diplopoda), were significantly depleted in13C suggesting that the majority of soil invertebrates obtain its carbon from roots. This is in stark contrast to the view that decomposer food webs are based on litter input from aboveground.
A latitudinal gradient in large‐scale beta diversity for vascular plants in North America
Authors: Qian Hong , Ricklefs Robert E. 
Published: June 2007

AbstractSpecies turnover, or beta diversity, has been predicted to decrease with increasing latitude, but few studies have tested this relationship. Here, we examined the beta diversity–latitude relationship for vascular plants at a continental scale, based on complete species lists of native vascular plants for entire states or provinces in North America (north of Mexico). We calculated beta diversity as the slope of the relationship between the natural logarithm of the Jaccard index (lnJ ) for families, genera or species, and both geographic distance and climate difference within five latitude zones. We found that beta diversity decreased from south to north; within latitude zones, it decreased from species to genera and families. Geographic and climatic distance explained about the same proportion of the variance in lnJ in zones south of c. 50°N. North of this latitude, nearly all the explained variance in lnJ was attributable to geographic distance. Therefore, decreasing beta diversity from south to north reflects decreasing climate differentiation within more northerly latitude zones, and primarily post‐glacial dispersal limitation north of 50°N.
Modelling the Dynamic Dependence Structure in Multivariate Financial Time Series
Authors: ŞErban Mihaela , Brockwell Anthony , Lehoczky John , Srivastava Sanjay 
Published: June 2007

Abstract.  The dependence structure in multivariate financial time series is of great importance in portfolio management. By studying daily return histories of 17 exchange‐traded index funds, we identify important features of the data, and we propose two new models to capture these features. The first is an extension of the multivariate BEKK (Baba, Engle, Kraft, Kroner) model, which includes a multivariate t‐type error distribution with different degrees of freedom. We demonstrate that this error distribution is able to accommodate different levels of heavy‐tailed behaviour and thus provides a better fit than models based on a multivariate t‐with a common degree of freedom. The second model is copula based, and can be regarded as an extension of the standard and the generalized dynamic conditional correlation model [Engle, Journal of Business and Economics Statistics (2002) Vol. 17, 425–446; Cappiello et al. (2003) Working paper, UCSD] to a Student copula. Model comparison is carried out using criteria including the Akaike information criteria and Bayesian information criteria. We also evaluate the two models from an asset‐allocation perspective using a three‐asset portfolio as an example, constructing optimal portfolios based on the Markowitz theory. Our results indicate that, for our data, the proposed models both outperform the standard BEKK model, with the copula model performing better than the extension of the BEKK model.
Short‐term impact of grassland fire on the endangered pygmy bluetongue lizard
Authors: Fenner A. L. , Bull C. M. 
Published: June 2007

AbstractWildfires may be beneficial to overall biodiversity in continuous habitat, but may have more severe impacts on individual species that are confined to small fragments of suitable habitat. The pygmy bluetongue lizard Tiliqua adelaidensis, is now confined to a few isolated fragments of previously extensive native grasslands in South Australia. A grassland fire that burned through the entire area of one population in December 2005 did not kill adult lizards, nor affect the subsequent fecundity of females, but was followed by significant reductions in activity and foraging and a decline in body condition relative to another population in an unburned site. While the study was not, and should not be replicated, our observations suggest that fire has a negative short‐term impact on isolated populations of this species.
Diving behaviour of Elseya albagula from a naturally flowing and hydrologically altered habitat
Authors: Gordos M. A. , Hamann M. , Schauble C. S. , Limpus C. J. , Franklin C. E. 
Published: June 2007

AbstractThis study investigated the diving behaviour and performance of the bimodally respiring turtle Elseya albagula within the Burnett River, central Qld, Australia. Diving parameters were recorded using pressure‐sensitive time‐depth recorders for turtles residing within a free flowing versus regulated reach. Maximum submergence time recorded for El. albagula (greater than 3 hours) is among the longest recorded for a voluntarily diving vertebrate, and is attributed to the turtle's ability to respire aquatically. Median dive times logged for El. albagula within the regulated reach (6.7 min) were threefold longer than values recorded for turtles residing within a naturally flowing creek (1.9 min), with discrepancies in dive duration possibly due to the variable hydrologic flows recorded below the weir. No correlation was observed between dive duration and subsequent surfacing intervals, suggesting that dives remained aerobic throughout the study. Despite considerable differences in the magnitude and daily variation of water flow between the two locations, similar diel activity and surfacing trends were recorded for El. albagula. Turtles undertook deep resting dives (>1.5 m) during the day before moving into shallower habitats (<1.0 m) for the night, while the crepuscular hours were characterized by elevated surfacing frequencies attributed to periods of increased activity possibly associated with foraging.
Genetic evaluation of the captive breeding program of the Persian wild ass
Authors: Nielsen R. K. , Pertoldi C. , Loeschcke V. 
Published: June 2007

AbstractDuring the last century, many species have become endangered and conservation in terms of captive breeding has been crucial for their survival. Classical management of captive species is based on recorded genealogies. However, if pedigrees are incomplete or inaccurate, it can bias the interpretation of the results obtained from analyses based on such data. In this investigation, 12 microsatellite loci were investigated to evaluate the studbook information of the critically endangered Persian wild ass, Equus hemionus onager. Relatedness and inbreeding coefficients were calculated in order to compare the same coefficients estimated from the recorded studbook. A significant correlation between coefficients obtained by microsatellites and the studbook validates the recorded studbook as a reasonable tool for future genetic management. Furthermore, a Bayesian‐based method divided the captive onager population into four subgroups that indicate departure from random mating, and thus minor rotation of animals between zoos. Lastly, analyses for inferring past demographic changes revealed a gradual population decline and inbreeding over several generations. This may indicate a low genetic load in captive onagers as a consequence of some degree of purging. Consequently, the risk of inbreeding depression should currently be minimal in the captive breeding program. Therefore, it is recommended to increase the connectivity between the four subgroups of onagers in order to reduce the risk of demographic and genetic stochasticity. This study underlines the importance of using molecular markers to evaluate genetic management of captive breeding programs.