bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pulsatile In Vitro Simulation of the Pediatric Univentricular Circulation for Evaluation of Cardiopulmonary Assist Scenarios
Authors: Dur Onur , Lara Mikhail , Arnold Dorian , Vandenberghe Stijn , Keller Bradley B. , DeGroff Curt , Pekkan Kerem 
Published: November 2009

AbstractThe characteristic depressed hemodynamic state and gradually declining circulatory function in Fontan patients necessitates alternative postoperative management strategies incorporating a system level approach. In this study, the single‐ventricle Fontan circulation is modeled by constructing a practical in vitro bench‐top pulsatile pediatric flow loop which demonstrates the ability to simulate a wide range of clinical scenarios. The aim of this study is to illustrate the utility of a novel single‐ventricle flow loop to study mechanical cardiac assist to Fontan circulation to aid postoperative management and clinical decision‐making of single ventricle patients. Two different pediatric ventricular assist devices, Medos and Pediaflow Gen‐0, are anastomosed in two nontraditional configurations: systemic venous booster (SVB) and pulmonary arterial booster (PAB). Optimum ventricle assist device strategy is analyzed under normal and pathological (pulmonary hypertension) conditions. Our findings indicate that the Medos ventricular assist device in SVB configuration provided the highest increase in pulmonary (46%) and systemic (90%) venous flow under normal conditions, whereas for the hypertensive condition, highest pulmonary (28%) and systemic (55%) venous flow augmentation were observed for the Pediaflow ventricular assist device inserted as a PAB. We conclude that mechanical cardiac assist in the Fontan circulation effectively results in flow augmentation and introduces various control modalities that can facilitate patient management. Assisted circulation therapies targeting single‐ventricle circuits should consider disease state specific physiology and hemodynamics on the optimal configuration decisions.
Valve Surgery in Congenital Heart Disease
Authors: Luciani Giovanni Battista 
Published: November 2009

AbstractCongenital valve disease (CVD) occurs in isolated form or as part of complex malformations and presents distinct epidemiology, including: young age at onset; high prevalence of associated pathology; history of prior operations; critical clinical presentation. Therefore, multiple interventions are often needed, highlighting the palliative character of CVD surgery. At the same time, long‐term survival and satisfactory quality of life expectations must be satisfied in a young, active patient population. The present study analyzes the unique aspects of surgery for CVD by reviewing clinical experience with 565 consecutive patients operated during a 7‐year period. Treatment options and outcome are assessed with reference to the ability of respecting the unique demands of patients with CVD. In addition, future developments of CVD management are discussed.
Primary Care Providers' Views of Challenges and Rewards of Dementia Care Relative to Other Conditions
Authors: Harris Dorothy P. , Chodosh Joshua , Vassar Stefanie D. , Vickrey Barbara G. , Shapiro Martin F. 
Published: November 2009

OBJECTIVES: To compare primary care providers' (PCPs') perceptions about dementia and its care within their healthcare organization with perceptions of other common chronic conditions and to explore factors associated with differences.DESIGN: Cross‐sectional survey.SETTING: Three California healthcare organizations.PARTICIPANTS: One hundred sixty‐four PCPs.MEASUREMENTS: PCPs' views about primary care for dementia were analyzed and compared with views about care for heart disease, diabetes mellitus, and selected other conditions. Differences in views about conditions according to PCP type (internists, family physicians) were assessed. Multivariate analysis examined relationships between provider and practice characteristics and views about dementia care.RESULTS: More PCPs strongly agreed that older patients with dementia are difficult to manage (23.8%) than for heart disease (5.0%) or diabetes mellitus (6.3%); PCPs can improve quality of life for heart disease (58.9%) and diabetes mellitus (61.6%) than for dementia (30.9%); older patients should be routinely screened for heart disease (63.8%) and diabetes mellitus (67.7%) than dementia (55.5%); and their organizations have expertise/referral resources to manage diabetes mellitus (49.4%) and heart disease (51.8%) than dementia (21.1%). More PCPs reported almost effortless organizational care coordination for heart disease (13.0%) or diabetes mellitus (13.7%) than for dementia (5.6%), and a great deal or many opportunities for improvement in their ability to manage dementia (50.6%) than incontinence, depression, or hypertension (7.4–34.0%; all P<.05). Internists' views regarding dementia care were less optimistic than those of family physicians, but PCP type was unrelated to views on diabetes mellitus or heart disease.CONCLUSION: Improving primary care management of dementia should directly address PCP concerns about expertise and referral resources, difficulty of care provision, and PCP views about prospects for patient improvement.
El Consentimiento Informado Voluntario en la Investigación y la Asistencia Clínica: Una Actualización
Authors: Cahana Alex , Hurst Samia A. 
Published: November 2009

ResumenEl consentimiento informado es importante: en la investigación, permite que los sujetos puedan tomar una decisión informada y voluntaria de participar—o de no participar—en un proyecto en el cual se arriesgarán personalmente para beneficio de terceros. Tanto en la investigación como en la asistencia clínica, el consentimiento informado implica consentir que otros intervengan en la esfera privada de un individuo. El consentimiento informado generalmente comprende los elementos de revelación de información, capacidad de decisión, y actuación voluntaria. Para cada elemento existen dificultades y posibles mejoras. Sin embargo, la calidad del consentimiento informado y las estrategias de mejoramiento han sido objeto de investigación sólo recientemente. Este artículo presenta algunos resultados de estos recientes estudios, resumiendo su impacto sobre el consentimiento informado en los ámbitos de la investigación y la asistencia médica. Aunque muchos de los datos sufren de limitaciones, los resultados sugieren que el elemento de revelación de información ha mejorado, aún cuando sigue aplicándose en forma dispareja, a menudo con bajo entendimiento por parte de pacientes y sujetos de investigación. Es más, la confianza es importante para impulsar la participación en ensayos de investigación, de modo que las falsas expectativas, al generar desconfianza, arriesgan el esfuerzo. Aunque el mejoramiento de las planillas de consentimiento no parece tener efecto sobre el entendimiento, el mejoramiento del proceso actual de consentimiento puede tener un impacto positivo. Finalmente, disponiendo de mejor información se puede reducir la ansiedad, con muy poco impacto negativo sobre el nivel de reclutamiento de sujetos.
Resultados Basados en la Evidencia para la Investigación y Práctica Clínica del Dolor
Authors: Gatchel Robert J. , Theodore Brian R. 
Published: November 2009

ResumenEl crecimiento en la medicina basada en la evidencia ha creado la necesidad de obtener resultados confiables basados en evidencia para documentar reacciones a un tratamiento o para evaluar la eficacia y rendimiento económico de distintas modalidades de tratamientos. Según el modelo biopsicosocial, el dolor se conceptualiza como una compleja interacción de múltiples factores biológicos, psicológicos y sociales, que en conjunto juegan un papel en el desarrollo, agudización y prolongación del dolor. Por consiguiente, los resultados asociados con la gestión del dolor son por necesidad de naturaleza compleja y multifactorial. El presente artículo desarrolla dos categorías generales de resultados basados en la evidencia en la gestión del dolor: resultados reportados por pacientes y resultados objetivos. Los resultados reportados por pacientes se explican en el ámbito de las medidas de dolor, la calidad de vida relacionada con la salud, y los modelos psico‐sociales. Los resultados objetivos se desarrollan en el ámbito ocupacional y el grado de utilización de los servicios de salud. Cada sección elabora singulares modelos de cada una de las medida de resultados y destaca su concordancia con normas actuales de evidencia y con el estado actual de conocimiento en la investigación del dolor.
IMMUNOHEMATOLOGY: Identification and evaluation of false‐negative antibody screens
Authors: Powers Amy , Chandrashekar Sarayu , Mohammed Monique , Uhl Lynne 
Published: November 2009

Background: Non‐ABO alloantibodies are frequently implicated in hemolytic transfusion reactions and are a leading cause of transfusion‐related mortality. Detection of clinically significant non‐ABO alloantibodies is reliant on an antibody screen, which is prone to clerical, technical, and reagent error. Data on the frequency of false‐negative antibody screens due to the occurrence of these errors are scarce, and the true incidence of false‐negative antibody screens in everyday practice is unknown.STUDY DESIGN AND METHODS: Monitoring for false‐negative antibody screens is routinely performed in our institution. All cases of false‐negative antibody screens involving clinically significant antibodies were identified through review of the blood bank quality assurance records from 2004 to 2007. The clinical impact was recorded in each case.RESULTS: Twenty‐one cases of false‐negative antibody screens due to clinically significant antibodies were detected. Sources of error included testing error (12 cases), reagent red blood cell (RBC) failure (one case), and reagent limitations (one case). The cause of error was inconclusive in seven cases. Nine patients were found to have received antigen‐incompatible blood as a consequence of these errors, resulting in a single nonfatal hemolytic transfusion reaction.CONCLUSIONS: The identification and investigation of false‐negative antibody screens is a valuable quality assurance measure which can serve to monitor staff performance, identify cases of reagent RBC failure, and identify patients who have received antigen‐incompatible blood at risk for hemolytic transfusion reactions.
Characteristics of Work Interruptions During Medication Administration
Authors: Biron Alain D. , Lavoie‐Tremblay Mélanie , Loiselle Carmen G. 
Published: November 2009

Abstract Objective: To document characteristics of nurses’ work interruptions (WIs) during medication administration. Design: A descriptive observational study design was used along with a sample of 102 medication administration rounds. Data were collected on a single medical unit using a unit dose distribution system during fall 2007. Method: Data collection on WIs relied on direct structured observation. The following WI characteristics were recorded: source, secondary task, location, management strategies, and duration. Results: 374 WIs were observed over 59 hours 2 minutes of medication administration time (6.3 WI/hr). During the preparation phase, nurse colleagues (n= 36; 29.3%) followed by system failures such as missing medication or equipment (n= 28; 22.8%) were the most frequent source of WIs. Nurses were interrupted during the preparation phase mostly to solve system failures (n= 33; 26.8%) or for care coordination (n= 30; 24.4%). During the administration phase, the most frequent sources of WIs were self‐initiation (n= 41; 16.9%) and patients (n= 39; 16.0%). The most frequent secondary task undertaken during the administration phase was direct patient care (n= 105; 43.9%). WIs lasted 1 min 32 s on average, and were mostly handled immediately (n= 357; 98.3%). Conclusions: The process of medication administration is not protected against WIs, which poses significant risks. Clinical Relevance: Interventions to reduce WIs during the medication administration process should target nurses and system failures to maximize medication administration safety.
Depressive Symptoms Among HIV‐Positive Pregnant Women in Thailand
Authors: Ross Ratchneewan , Sawatphanit Wilaiphan , Zeller Richard 
Published: November 2009

Abstract Purpose: To examine predictors of depressive symptoms among human immunodeficiency virus (HIV)‐positive, pregnant women in Thailand. Design: Correlational, cross‐sectional study. Methods: Data were collected at prenatal clinics in five hospitals in Thailand from January 2004 to January 2006. One hundred twenty‐seven HIV‐positive pregnant women completed questionnaires in Thai on depressive symptoms, self‐esteem, emotional support, physical symptoms, and demographics. Simultaneous multiple regression was used to analyze predictors of depressive symptoms. Findings: Seventy‐eight percent of the 127 participants reported depressive symptoms to some degree. Physical symptoms (β= .192, p<.05) were positively associated with depressive symptoms, but self‐esteem (β=−.442, p<.001), emotional support (β=−.193, p<.01), and financial status (β=−.209, p<.01) were negatively correlated with depressive symptoms. Conclusions: The study results have added new knowledge about depressive symptoms and their predictors in HIV‐positive pregnant women in Thailand. Clinical Relevance: Depressive symptoms have been associated with faster progression to acquired immunodeficiency syndrome among HIV‐positive individuals. The high rate of depression in our study suggests that HIV‐positive pregnant women in Thailand should all be screened for depressive symptoms. Causes of physical symptoms should be identified and treated. Emotional support and self‐esteem should be strengthened for HIV‐positive pregnant Thai women.
Evaluation of a Patient Care Delivery Model: Patient Outcomes in Acute Cardiac Care
Authors: Meyer Raquel M. , Wang Sping , Li Xiaoqiang , Thomson Donna , O’Brien‐Pallas Linda 
Published: November 2009

Abstract Purpose: To evaluate the influence of nurse staffing and work environment variables on patient outcomes by testing a conceptual model. Design: A prospective, correlational design with cross‐sectional and longitudinal components was conducted in Canadian cardiac and cardiovascular care inpatient units. Methods: Data were collected from multiple sources. Hierarchical linear modeling was used to examine relationships among variables. Conclusions: The findings indicate that patient outcomes are influenced not only by patient and nurse characteristics, but also by organizational staffing practices. Organizations that manage the complexity of work conditions and target staffing utilization levels between 80% and 88% at the unit level can optimize patient outcomes. Clinical Relevance: Empirical validation of the model provides evidence to inform management decisions about hospital nurse staffing.
Structural change in the West German agricultural sector
Authors: Huettel Silke , Margarian Anne 
Published: November 2009

AbstractThis article explains regionally differentiated patterns of structural change based on a theoretical framework dealing with strategic interaction of farms on the land market. The main research question focuses on the causes of regionally persistent structures. An empirical Markov chain model is defined for the West German agricultural sector. The model is used to explain the probabilities of farm growth, decline, or exit in terms of the current and former regional farm size structure. Further, the impact of variables describing the regional farm structure, thereby indicating market power of the large, the potential of high competition for land within a region, and possibly high rents of the status quo in combination with sunk costs, is quantified. The results confirm the relevance of strategic interaction as a crucial determinant of persistent regional differences in the farm size structure over time.
Smallholders, institutional services, and commercial transformation in Ethiopia
Authors: Gebremedhin Berhanu , Jaleta Moti , Hoekstra Dirk 
Published: November 2009

AbstractThis article examines the role of institutional services of credit, input supply, and extension in the overall commercial transformation process of smallholder agriculture in Ethiopia. Survey data collected in 2006 from 309 sample households in three districts of Ethiopia are used for the analyses. Tobit regression models are used to measure the effect of access to services on the intensity of inputs use for fertilizer and agrochemicals. A probit model is used to measure these effects on the adoption of improved seeds. Intensity of use of seeds is analyzed using an ordinary least squares model. Logarithmic Cobb–Douglass functions are estimated to analyze the effect of access to services on crop productivity. Heckman's two‐stage estimation is used to examine determinants of household market participation and the extents of participation. Results show that access to institutional support services plays a significant role in enhancing smallholder productivity and market orientation. Our results imply that expanding and strengthening the institutional services is critical for the intensification and market orientation of smallholder agriculture in Ethiopia. In particular, appropriate incentives and regulatory systems are urgently needed to encourage the involvement of the private sector in the provision of agricultural services.
The growth of family farms in Hungary
Authors: Bakucs Lajos Zoltán , Fertő Imre 
Published: November 2009

AbstractThe article investigates the validity of Gibrat's Law for Hungarian family farms using FADN data collected between 2001 and 2007. Gibrat's Law states that the growth rate of firms will be independent of their initial size. Regression results allow us to reject Gibrat's Law for all quantiles. Evidence suggests that smaller farms tend to grow faster than larger ones. Results do not support the hypothesis of “disappearing middle” in Hungarian agriculture. We study a number of socio‐economic factors that can help to explain farm growth. We find that total subsidies received by a farm and the farm operator's age are the most significant factors correlated with farm growth.
Small U.S. dairy farms: can they compete?
Authors: Nehring Richard , Gillespie Jeffrey , Sandretto Carmen , Hallahan Charlie 
Published: November 2009

AbstractThe U.S. dairy industry is undergoing rapid structural change, evolving from a structure including many small farmers in the Upper Midwest and Northeast to one that includes very large farms in new production regions. Small farms are struggling to retain competitiveness via improved management and low‐input systems. Using data from USDA's Agricultural Resource Management Survey, we determine the extent of U.S. conventional and pasture‐based milk production during 2003–2007, and estimate net returns, scale efficiency, and technical efficiency associated with the systems across different operation sizes. We compare the financial performance of small conventional and pasture‐based producers with one another and with large‐scale producers. A stochastic production frontier is used to analyze performance over the period for conventional and pasture technologies identified using a binomial logit model. Large conventional farms generally outperformed smaller farms using most economic measures—technical efficiency, various profitability measures, and returns to scale.
A maximum stellar surface density in dense stellar systems
Authors: Hopkins Philip F. , Murray Norman , Quataert Eliot , Thompson Todd A. 
Published: November 2009

Abstract
We compile observations of the surface mass density profiles of dense stellar systems, including globular clusters in the Milky Way and nearby galaxies, massive star clusters in nearby starbursts, nuclear star clusters in dwarf spheroidals and late-type discs, ultra-compact dwarfs, and galaxy spheroids spanning the range from low-mass ‘cusp’ bulges and ellipticals to massive ‘core’ ellipticals. We show that in all cases the maximum stellar surface density attained in the central regions of these systems is similar, Σmax ∼ 1011 M⊙ kpc−2 (∼20 g cm−2), despite the fact that the systems span ∼7 orders of magnitude in total stellar mass M* and ∼5 in effective radius Re, and have a wide range in effective surface density M*/R2e. The surface density limit is reached on a wide variety of physical scales in different systems and is thus not a limit on three-dimensional stellar density. Given the very different formation mechanisms involved in these different classes of objects, we argue that a single piece of physics likely determines Σmax. The radiation fields and winds produced by massive stars can have a significant influence on the formation of both star clusters and galaxies, while neither supernovae nor black hole accretion is important in star cluster formation. We thus conclude that feedback from massive stars likely accounts for the observed Σmax, plausibly because star formation reaches an Eddington-like flux that regulates the growth of these diverse systems. This suggests that current models of galaxy formation, which focus on feedback from supernovae and active galactic nuclei, are missing a crucial ingredient.
Infrastructure Financing and Operation in the Contemporary City
Authors: O'NEILL PHILLIP M. 
Published: November 2009

AbstractThe provision of large economic infrastructure in Australian cities is widely seen to be in crisis. This paper examines the reasons why crisis has arisen in the urban infrastructure sector and what might be done to redress this. The analysis and the argument are based on a resuscitation of the ideas and ideals of infrastructure provision and how these have been eroded. The paper shows how these ideas/ideals once underpinned the formulation of state role, governance and regulation systems, financial arrangements, and even community need and expectation. Critical to this was an acceptance of the ideals of universality, access, bundling and free positive externalities, and the belief that these should be assembled necessarily as part of any urban infrastructure roll‐out. This package became instinctive in post‐war economic and urban management. Yet this instinct has been lost as governments shift from models of infrastructure provision to infrastructure procurement where a major role for the private sector is now common. While such an involvement has its benefits, there are concerns for the urban condition when privatisation of infrastructure construction, delivery and operation becomes dominant. Citing Graham and Marvin (2001), the paper argues that, where once infrastructure was the key device for integrating the elements of the city and its people, the way it is now being delivered produces a splintered urbanism. There is an urgent need, then, to re‐think what infrastructure means in today's urban context and thereafter to re‐assess the criteria for deciding what infrastructure is to be provided, in what form it should be provided, who should provide it, who should pay, and who should operate it.