bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predictors of Nurse Practitioners' Autonomy: Effects of Organizational, Ethical, and Market Characteristics
Authors: Ulrich Connie , Soeken Karen , Miller Nancy 
Published: February 2008

PurposeTo identify the predictors of autonomy of nurse practitioners (NPs) affiliated directly and/or indirectly with managed‐care systems (e.g., HMOs).Data SourcesA mailed survey sent to a stratified random sample of 254 NPs certified and licensed to practice in the state of Maryland. The measures consisted of selected organizational characteristics; market factors of HMO penetration and percentage of client population enrolled in managed care; and factors of ethical concern, such as ethical ideology, ethics education, and autonomy. The County Surveyor Database was used to assess market penetration in the state.ConclusionsAlthough NPs were ethically concerned about their autonomy in a managed‐care environment (70.2%), actual autonomy scores were high. The higher the percentage of HMO penetration, percentage of client population enrolled in managed care, and perceived ethical concern, the lower the perceived autonomy of NPs.Implications for PracticeFindings may be used for future research to address the complexity of variables that influence the autonomous practice of NPs.
Estimation of walrus populations on sea ice with infrared imagery and aerial photography
Authors: Udevitz Mark S. , Burn Douglas M. , Webber Marc A. 
Published: February 2008

AbstractPopulation sizes of ice‐associated pinnipeds have often been estimated with visual or photographic aerial surveys, but these methods require relatively slow speeds and low altitudes, limiting the area they can cover. Recent developments in infrared imagery and its integration with digital photography could allow substantially larger areas to be surveyed and more accurate enumeration of individuals, thereby solving major problems with previous survey methods. We conducted a trial survey in April 2003 to estimate the number of Pacific walruses (Odobenus rosmarus divergens) hauled out on sea ice around St. Lawrence Island, Alaska. The survey used high altitude infrared imagery to detect groups of walruses on strip transects. Low altitude digital photography was used to determine the number of walruses in a sample of detected groups and calibrate the infrared imagery for estimating the total number of walruses. We propose a survey design incorporating this approach with satellite radio telemetry to estimate the proportion of the population in the water and additional low‐level flights to estimate the proportion of the hauled‐out population in groups too small to be detected in the infrared imagery. We believe that this approach offers the potential for obtaining reliable population estimates for walruses and other ice‐associated pinnipeds.
Changes in diets of individual Baltic ringed seals (Phoca hispida botnica) during their breeding season inferred from stable isotope analysis of multiple tissues
Authors: Sinisalo Tuula , Jones Roger I. , Helle Eero , Valtonen E. Tellervo 
Published: February 2008

AbstractThe stable isotope ratios (δ13C and δ15N) of three tissues with different metabolic rates (plasma, liver, and muscle) were used to investigate temporal variation in diet among nine individual Baltic ringed seals (Phoca hispida botnica Gmelin) from the Bothnian Bay, northeast Baltic Sea. The isotope values from plasma should reflect the most recent diet, values from liver the diet of the past weeks prior to sampling, and values from muscle should integrate diet over almost the entire breeding season of the ringed seals. In general, δ13C values of liver were more enriched in 13C than were those of either muscle or plasma, suggesting that the diet of the seals may have included a higher proportion of 13C‐enriched benthic prey in April. Females showed more variable δ13C values than males, suggesting possible gender differences in diet or in foraging locations. The differences that were apparent between females possibly reflect individual variation in the onset and duration of parturition and lactation, both of which likely restrict female foraging. Previous data from parasite infections and from alimentary tract contents of the same seals were linked to the isotope data to assist in drawing inferences about changes in the diets of individual seals.
Using form analysis techniques to improve photogrammetric mass‐estimation methods
Authors: Proffitt Kelly M. , Garrott Robert A. , Rotella Jay J. , Lele Subhash 
Published: February 2008

AbstractNumerical characterization of animal body forms using elliptical Fourier decomposition may be a useful analytic technique in a variety of marine mammal investigations. Using data collected from the Weddell seal (Leptonychotes weddellii), we describe the method of body form characterization using elliptical Fourier analysis and demonstrated usefulness of the technique in photogrammetric mass‐estimation modeling. We compared photogrammetric mass‐estimation models developed from (1) standard morphometric measurement covariates, (2) elliptical Fourier coefficient covariates, and (3) a combination of morphometric and Fourier coefficient covariates and found that mass‐estimation models employing a combination of morphometric measurements and Fourier coefficients outperformed models containing only one covariate type. Inclusion of Fourier coefficients in photogrammetric mass‐estimation models employing standard morphometric measurements reduced the width of the prediction interval by 24.4%. Increased precision of photogrammetric mass‐estimation models employing Fourier coefficients as model covariates may expand the range of ecological questions that can be addressed with estimated mass measurements.
Ontogenetic diet changes in bottlenose dolphins (Tursiops truncatus) reflected through stable isotopes
Authors: Knoff Amanda , Hohn Aleta , Macko Stephen 
Published: February 2008

AbstractThe ability of stable isotope analysis to provide insight into ontogenetic dietary changes was examined using bottlenose dolphin tooth and skin samples. Teeth were subsampled to compare tissue produced early in life (outer tooth) to that produced later in life (inner tooth). Outer tooth had significantly higher δ15N values than the corresponding inner sample from the same tooth (n= 60, P= 0.0041), indicating that there was a temporal shift to a lower δ15N diet. There were no significant δ13C differences. Higher δ15N values in young have previously been attributed to the period of suckling. Analysis of skin tissue from stranded animals of different developmental stages similarly indicated that the δ15N values were significantly higher in young animals. Further comparisons indicated that the primary influence for this difference was animals with lengths less than or equal to the largest neonatal dolphin. This difference likely reflects an ontogenetic dietary shift from a sole reliance on milk to a combination of milk and prey species during the first year of life.
Removal of iron dextran (Cosmofer®) during hemodialysis
Authors: CHEN YUQING , WANG MEI 
Published: February 2008

SUMMARYIntravenous iron dextran is widely used in hemodialysis patients receiving erythropoietin (EPO) therapy because of its significant convenience in clinical practice. However, the amount of iron removed by hemodialysis in vivo is unknown. The purpose of this study was to measure the removal of iron dextran in patients undergoing hemodialysis. Six patients were enrolled in this study. All were stable patients treated by hemodialysis for at least 1 month. Both F6 (polysulphone membrane) and GFSplus12 (hemophane membrane) dialyzers were used sequentially in each patient. Each patient received 2 mL of low‐molecular‐weight iron dextran (Cosmofer® aktieselskab/aksjeselskap and supplied by Zhuhai Schwarz Pharma Company Ltd) intravenously, containing 100 mg of elemental iron, administered during the second hour of dialysis over 30 to 60 minutes. A baseline sample of fresh dialysate was collected before the commencement of dialysis. A control sample of spent dialysate was collected during the first hour of dialysis, before the infusion of low‐molecular‐weight iron dextran. Then, all spent dialysate after the iron dextran infusion until the end of dialysis was collected. The samples were treated with lanthanum nitrate solution, and the iron content was measured using an atomic‐absorptive spectrum method. The iron concentration in the control group was 4.31 ± 2.55 µg/L. After the infusion of iron dextran, the iron concentration in the spent dialysate increased significantly, irrespective of whether an F6 or GFSplus12 dialyzer was used. However, the amount of iron eliminated through the dialyzer was minimal, less than 3% of the infusion dose. There was no significant difference in removal of iron through either the F6 or GFSplus12 dialyzer. These results indicate that the removal of iron dextran by hemodialysis when using either a polysulfphone or hemophane membrane dialyzer is negligible. It is time‐efficient and convenient to administer low‐molecular‐weight iron dextran during hemodialysis.
Pelvic surgery in a child with hemophilia C: a rare disease, a real challenge, a simple solution
Authors: HOLTAN ANDERS , KONGSGAARD Ulf E. , BROSSTAD FRANK 
Published: February 2008

SUMMARYCoagulation factor XI deficiency, also called hemophilia C, is the least common type of hemophilia in Norway. It differs from hemophilia A and B in its unpredictable clinical pattern. Patients often have no spontaneous bleeding tendency, but they can have serious and life‐threatening bleedings when suffering trauma or undergoing surgical procedures. We report the case of a child with a hitherto undiagnosed factor XI deficiency. She had previously experienced excessive bleeding and required transfusion of saline‐adenine‐glucose erythrocytes after minor surgery. The patient was planned to a major surgical procedure with partial pelvic resection (hemipelvectomy) because of an Ewing sarcoma. Routine preoperative coagulation tests showed a moderately elevated international normalized ratio and a substantially prolonged activated partial thromboplastin time, which were due to a factor XI level at 0.2% of normal. Perioperative management of the patient was planned in collaboration with a coagulation specialist. In addition to replacement of erythrocytes, two different mechanisms were targeted for correcting the hemostatic defect. Substitution of factor XI was done by infusion of plasma, and inhibition of fibrinolysis was achieved by systemic and local administration of tranexamic acid. Surgery was then performed without excessive bleeding, and the patient did not require postoperative blood transfusions.
Different Pathways to Acquiring Resistance Genes Illustrated by the Recent Evolution of IncW Plasmids
Authors: Revilla Carlos , Garcillán-Barcia M. Pilar , Fernández-López Raúl , Thomson Nicholas R. , Sanders Mandy , Cheung Martin , Thomas Christopher M. , de la Cruz Fernando 
Published: February 2008

ABSTRACT

DNA sequence analysis of five IncW plasmids (R388, pSa, R7K, pIE321, and pIE522) demonstrated that they share a considerable portion of their genomes and allowed us to define the IncW backbone. Among these plasmids, the backbone is stable and seems to have diverged recently, since the overall identity among its members is higher than 95%. The only gene in which significant variation was observed was
trwA
; the changes in the coding sequence correlated with parallel changes in the corresponding TrwA binding sites at
oriT
, suggesting a functional connection between both sets of changes. The present IncW plasmid diversity is shaped by the acquisition of antibiotic resistance genes as a consequence of the pressure exerted by antibiotic usage. Sequence comparisons pinpointed the insertion events that differentiated the five plasmids analyzed. Of greatest interest is that a single acquisition of a class I integron platform, into which different gene cassettes were later incorporated, gave rise to plasmids R388, pIE522, and pSa, while plasmids R7K and pIE321 do not contain the integron platform and arose in the antibiotic world because of the insertion of several antibiotic resistance transposons.
Relationship between Antimalarial Activity and Heme Alkylation for Spiro- and Dispiro-1,2,4-Trioxolane Antimalarials
Authors: Creek Darren J. , Charman William N. , Chiu Francis C. K. , Prankerd Richard J. , Dong Yuxiang , Vennerstrom Jonathan L. , Charman Susan A. 
Published: February 2008

ABSTRACT

The reaction of spiro- and dispiro-1,2,4-trioxolane antimalarials with heme has been investigated to provide further insight into the mechanism of action for this important class of antimalarials. A series of trioxolanes with various antimalarial potencies was found to be unreactive in the presence of Fe(III) hemin, but all were rapidly degraded by reduced Fe(II) heme. The major reaction product from the heme-mediated degradation of biologically active trioxolanes was an alkylated heme adduct resulting from addition of a radical intermediate. Under standardized reaction conditions, a correlation (
R
2
= 0.88) was found between the extent of heme alkylation and in vitro antimalarial activity, suggesting that heme alkylation may be related to the mechanism of action for these trioxolanes. Significantly less heme alkylation was observed for the clinically utilized artemisinin derivatives compared to the equipotent trioxolanes included in this study.
Safety, Tolerance, and Pharmacokinetic Studies of OPT-80 in Healthy Volunteers following Single and Multiple Oral Doses
Authors: Shue Y. K. , Sears P. S. , Shangle S. , Walsh R. B. , Lee C. , Gorbach S. L. , Okumu F. , Preston R. A. 
Published: February 2008

ABSTRACT

Current therapies for
Clostridium difficile
infection (CDI) are encumbered by treatment failures and recurrences. Due to its high in vitro activity against
C. difficile
but low activity against the typical intestinal flora, minimal absorption, and durable cure in the hamster model of
C. difficile
infection, OPT-80 was considered for clinical development as a therapy for CDI. This trial consisted of two phases. Four single oral doses of OPT-80 (100, 200, 300, and 450 mg) were administered in a crossover manner to 16 healthy volunteers in a double-blind, placebo-controlled phase 1A study; a 1- to 2-week washout interval separated the treatments. In the double-blind phase 1B study, 24 healthy subjects were randomized to receive OPT-80 (150, 300, or 450 mg) or placebo for 10 days. In both studies, OPT-80's safety and tolerability were evaluated and the concentrations of OPT-80 and its primary metabolite (OP-1118) in plasma and feces were determined. OPT-80 levels in the urine were also analyzed for the phase 1A study. In both the single-dose and the multiple-dose studies, OPT-80 was well tolerated by all subjects in all dose groups. Maximal plasma concentrations were near or below the limit of quantification (5 ng/ml) across the dose range; urine concentrations were below the detection limit. The fecal total recovery of OPT-80 plus its major metabolite, OP-1118, approximated 100%. The tolerability, high fecal concentration, and low systemic exposure data from these studies support the further clinical development of OPT-80 as an oral therapy for CDI.
Role of the AheABC Efflux Pump in
Aeromonas hydrophila
Intrinsic Multidrug Resistance
Authors: Hernould Mathieu , Gagné Séverine , Fournier Michel , Quentin Claudine , Arpin Corinne 
Published: February 2008

ABSTRACT

Gene inactivation and complementation experiments showed that the tripartite AheABC efflux pump of
Aeromonas hydrophila
extruded at least 13 substrates, including nine antibiotics. The use of phenylalanine-arginine-β-naphthylamide (PAβN) revealed an additional system(s) contributing to intrinsic resistance. This is the first analysis of the role of multidrug efflux systems in
Aeromonas
spp.
Recovery of Humoral Immunity Is Critical for Successful Antiviral Therapy in Disseminated Mouse Adenovirus Type 1 Infection
Authors: Lenaerts L. , Kelchtermans H. , Geboes L. , Matthys P. , Verbeken E. , De Clercq E. , Naesens L. 
Published: February 2008

ABSTRACT
Severe adenovirus infections in transplant recipients undergoing immunosuppressive therapy are of increasing concern. Controversy exists on the contribution of antiviral therapy and the host immune response to recovery from these infections. Here, we established a systemic mouse adenovirus type 1 (MAV-1) infection in cyclophosphamide (CyP)-treated BALB/c mice. CyP was administered at 100 mg per kg of body weight every other day for 2, 3, or 4 weeks, thereby inducing general but reversible leukopenia, with a major suppression of the B-cell numbers and functionality that was more pronounced than that seen with T cells. The outcome of MAV-1 infection was dependent on the duration of CyP therapy, as the mice with the most severe immunosuppression were the most vulnerable to MAV-1-induced hemorrhagic enteritis and mortality. The protective effect of concomitant antiviral therapy with cidofovir depended on the level of immunosuppression. The combination of cidofovir treatment with the withdrawal of immunosuppression was the most successful regimen for increasing survival rates. Survival was clearly correlated with the clearance of virus and increased titers of MAV-1-specific antibodies in sera. In addition, the passive transfer of MAV-1-specific immunoglobulin G into MAV-1-infected SCID BALB/c mice caused a marked delay in mortality, the extent of the delay being dependent on the titer of MAV-1-specific antibodies. Based on the critical role of the humoral immune response in the early defense against disseminated adenovirus infection, the concomitant use of adenovirus-specific immunoglobulins and antiviral therapy should be considered for transplant patients at risk for severe adenovirus infections.
Malaria Treatment with Atovaquone-Proguanil in Malaria-Immune Adults: Implications for Malaria Intervention Trials and for Pre-Exposure Prophylaxis of Malaria
Authors: Polhemus Mark E. , Remich Shon , Ogutu Bernhards , Waitumbi John , Lievens Marc , Ballou W. Ripley , Heppner D. Gray 
Published: February 2008

ABSTRACT

Eighty adults in areas of Kenya where malaria is holoendemic received presumptive treatment with atovaquone-proguanil and were followed closely. The time to the first
Plasmodium falciparum
parasitemia was 32 days. This prolonged prophylaxis period has implications for study design when used in malaria intervention trials and cautiously suggests clinical investigation of potential preexposure prophylaxis of malaria.
Iron-Regulated Biofilm Formation inStaphylococcus aureusNewman Requiresicaand the Secreted Protein Emp
Authors: Johnson Miranda , Cockayne Alan , Morrissey Julie A. 
Published: February 2008

ABSTRACTStaphylococcus aureusbiofilm formation is induced in iron-restricted growth conditions in vitro. In this study, we showed that Emp and Eap play important roles in low-iron-induced biofilm formation ofS. aureusNewman. Eap and Emp are secreted proteins which are non-covalently attached to theS. aureuscell surface and have previously been implicated in a number of aspects ofS. aureuspathogenesis. We showed here that the transcription of these important virulence factors is induced by growth in low-iron medium, reflective of the in vivo environment. Our results show that iron regulation of Eap and Emp is Fur independent. However, Fur is required for full induction ofeapandempexpression in low-iron conditions. In this study, we demonstrated that in addition to Fur, low-iron-induced biofilm formation requires Sae, Agr, and SarA. In iron-restricted growth conditions, Sae and Agr are essential for Emp and Eap expression and hence for biofilm formation, whereas SarA appears to have a less-significant role. We also showed that expression of theicaoperon is required for biofilm formation in iron-restricted growth conditions. We demonstrated that in fact,icais required for the expression of the important multifunctional virulence determinantseapandemp.
What Should Be Considered When Simulating Doppler Velocities Measured by Ground-Based Weather Radars?
Authors: Caumont Olivier , Ducrocq Véronique 
Published: February 2008

Abstract
A sophisticated and flexible simulator of Doppler velocities measured by ground-based weather radars is appended to a high-resolution nonhydrostatic atmospheric model. Sensitivity experiments are conducted by using different configurations for each of the physical processes that is modeled by the simulator. It is concluded that neglecting the vertical beam broadening effect or the weighting by reflectivities yields errors of the same order on the simulated reflectivities. Neglecting hydrometeor fall speeds has a much smaller impact. It is also shown that neglecting both the beam broadening effect and the weighting by reflectivities yields errors of the same order as occur when only one of these effects is neglected.
Drag of the Water Surface at Very Short Fetches: Observations and Modeling
Authors: Caulliez Guillemette , Makin Vladimir , Kudryavtsev Vladimir 
Published: February 2008

AbstractThe specific properties of the turbulent wind stress and the related wind wave field are investigated in a dedicated laboratory experiment for a wide range of wind speeds and fetches, and the results are analyzed using the wind-over-waves coupling model. Compared to long-fetch ocean wave fields, wind wave fields observed at very short fetches are characterized by higher significant dominant wave steepness but a much smaller macroscale wave breaking rate. The surface drag dependence on fetch and wind then closely follows the dominant wave steepness dependence. It is found that the dimensionless roughness length z*0 varies not only with wind forcing (or inverse wave age) but also with fetch. At a fixed fetch, when gravity waves develop, z*0 decreases with wind forcing according to a −1/2 power law. Taking into account the peculiarities of laboratory wave fields, the WOWC model predicts the measured wind stress values rather well. The relative contributions to surface drag of the equilibrium-range wave-induced stress and the airflow separation stress due to wave breaking remain small, even at high wind speeds. At moderate to strong winds, the form drag resulting from dominant waves represents the major wind stress component.
Measurements of the Transmission Loss of a Radome at Different Rain Intensities
Authors: Kurri Mikko , Huuskonen Asko 
Published: February 2008

Abstract
Results on the transmission loss of a dry and a wet C-band weather radar radome at different rain intensities are presented. Two methods were used in the study, both carried out under laboratory conditions. In the first method, the complex permittivity of a dry radome is measured and the transmission loss calculated. To analyze the transmission loss of a wet radome, the thickness of a continuous water layer on the surface of a radome at different rain intensities and the complex permittivity of water are calculated. In the second method, the transmission loss is measured as a free space transmission measurement with a 1.3-m2 piece of a radome panel. The piece is measured as dry and as doused by a rain system designed for the measurements. The measurements are performed with a dirty, cleaned, and waxed radome to examine the effects of maintenance measures with an old radome on the transmission loss. Because the transmission loss as a function of rain intensity is measured with a small piece of radome, a method is developed to scale the free space measurements for a complete 6.7-m-diameter radome with equal dielectric properties. Results of the one-way transmission loss of a dry radome with the permittivity and free space measurements are in a good agreement (0.34 and 0.35 dB, respectively). According to the analysis, a continuous water layer on a radome has a significant influence on the transmission loss. A 3-dB two-way transmission loss caused by a dirty radome is observed at a rain intensity of 15.1 mm h−1. Waxing gives promising results in reducing the wet radome loss because the waxing prevents the formation of a continuous water layer on the surface of the radome.