bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ecological factors and human threats both drive wildfowl population declines
Authors: Long P. R. , Székely T. , Kershaw M. , O'Connell M. 
Published: January 2007

AbstractMany wildfowl species are declining and 34 out of 159 extant species are globally threatened, some of which are the subject of specific conservation programmes. Here we investigate which factors predict declining population trends across 154 species of Anseriformes. First we show that there are proportionately fewer declining wildfowl populations in North America, Europe and Australasia than in south and central America, Africa and Asia. Second, we use phylogenetic comparative analyses to test whether population size, global range size and ecological, life‐history and sexually‐selected traits predict population trends. We also consider anthropogenic threats, and human impacts within the breeding and non‐breeding ranges of species. Using phylogenetically independent contrasts we show that small population size and small global ranges are the most important intrinsic factors that predispose wildfowl species to declining populations. Many wildfowl are hunted but, contrary to expectation, hunting did not influence population trends. Declining populations were associated with high International Union for the Conservation of Nature (IUCN) threat category, although the relationship is not very strong (r=0.134, n=129 contrasts) possibly because the IUCN criteria integrate population size, range size and an assessment of threat. Two extrinsic factors were significant predictors of population declines: the increase in area of agricultural land within a species' range (an indirect measure of wetland loss), and the total number of different threat processes such as habitat loss and pollution that threaten a species. Taken together, our results strongly suggest that both anthropogenic threats and intrinsic ecological factors are influencing population declines in wildfowl.
Pollen limitation meets resource allocation: towards a comprehensive methodology
Authors: Wesselingh Renate A. 
Published: January 2007

SummaryThe standard method of measuring pollen limitation is to add pollen to a number of flowers, preferably to a whole plant, and to compare fruit and seed set with that of naturally pollinated flowers on other plants. In 25 yr of research, this method has yielded valuable data, but it is difficult to use in large plants. This has caused a bias in the available data towards smaller, herbaceous plants with relatively few flowers. I argue that, in order to widen our knowledge of how pollen limitation affects plants, we should go beyond whole‐plant pollen addition and change our concept of how a flowering plant functions. The traditional method does not take into account the variation in and dynamics of resource allocation and pollen availability. The concept of integrated physiological units (IPUs) does, but, although it has been applied to pollination biology, it has not received the attention it deserves. I use this article to present its merits again, to propose a step‐by‐step methodology for studying pollen limitation, and to examine factors influencing possible plant strategies.
Caesarean delivery and risk of stillbirth in subsequent pregnancy: a retrospective cohort study in an English population
Authors: Gray R , Quigley MA , Hockley C , Kurinczuk JJ , Goldacre M , Brocklehurst P 
Published: January 2007

Objective Two recent studies indicate an increased risk of stillbirth in the pregnancy that follows a pregnancy delivered by caesarean section. In this study, we report an analysis designed to test the hypothesis that delivery by caesarean section is a risk factor for explained or unexplained stillbirth in any subsequent pregnancy. We also report on the proportion of stillbirths in our study population, which may have been attributable to previous delivery by caesarean section.Design Retrospective cohort study.Population Linked statistical data set of 81 784 singleton deliveries registered in Oxfordshire and West Berkshire between 1968 and 1989.Methods The crude and adjusted hazard ratios for stillbirth in deliveries following a previous delivery by caesarean section, compared with no previous caesarean, were estimated using Cox regression.Main outcome measure Stillbirth.Results The unadjusted hazard ratios for all, explained, and unexplained stillbirths were 1.54 (95% CI 1.04–2.29); 2.13 (1.22–3.72); and 1.19 (0.68–2.09), respectively. After adjustment for maternal age, parity, social class, previous adverse outcome of pregnancy, body mass indexand smoking the hazard ratios were 1.58 (0.95–2.63), 2.08 (1.00–4.31) and 1.24 (0.60–2.56).Conclusions Pregnancies in women following a pregnancy delivered by caesarean section are at an increased risk of stillbirth. In our study, the risk appears to be mainly concentrated in the subgroup of explained stillbirths. However, there are sufficient inconsistencies in the developing literature about stillbirth risk that further research is needed.
Modulation of inflammation in brain: a matter of fat
Authors: Farooqui Akhlaq A. , Horrocks Lloyd A. , Farooqui Tahira 
Published: January 2007

AbstractNeuroinflammation is a host defense mechanism associated with neutralization of an insult and restoration of normal structure and function of brain. Neuroinflammation is a hallmark of all major CNS diseases. The main mediators of neuroinflammation are microglial cells. These cells are activated during a CNS injury. Microglial cells initiate a rapid response that involves cell migration, proliferation, release of cytokines/chemokines and trophic and/or toxic effects. Cytokines/chemokines stimulate phospholipases A2 and cyclooxygenases. This results in breakdown of membrane glycerophospholipids with the release of arachidonic acid (AA) and docosahexaenoic acid (DHA). Oxidation of AA produces pro‐inflammatory prostaglandins, leukotrienes, and thromboxanes. One of the lyso‐glycerophospholipids, the other products of reactions catalyzed by phospholipase A2, is used for the synthesis of pro‐inflammatory platelet‐activating factor. These pro‐inflammatory mediators intensify neuroinflammation. Lipoxin, an oxidized product of AA through 5‐lipoxygenase, is involved in the resolution of inflammation and is anti‐inflammatory. Docosahexaenoic acid is metabolized to resolvins and neuroprotectins. These lipid mediators inhibit the generation of prostaglandins, leukotrienes, and thromboxanes. Levels of prostaglandins, leukotrienes, and thromboxanes are markedly increased in acute neural trauma and neurodegenerative diseases. Docosahexaenoic acid and its lipid mediators prevent neuroinflammation by inhibiting transcription factor NFκB, preventing cytokine secretion, blocking the synthesis of prostaglandins, leukotrienes, and thromboxanes, and modulating leukocyte trafficking. Depending on its timing and magnitude in brain tissue, inflammation serves multiple purposes. It is involved in the protection of uninjured neurons and removal of degenerating neuronal debris and also in assisting repair and recovery processes. The dietary ratio of AA to DHA may affect neurodegeneration associated with acute neural trauma and neurodegenerative diseases. The dietary intake of docosahexaenoic acid offers the possibility of counter‐balancing the harmful effects of high levels of AA‐derived pro‐inflammatory lipid mediators.
The effect of environmental variables on soil characteristics at different scales in the transition zone of the Loess Plateau in China
Authors: Liu S. L. , Guo X. D. , Fu B. J. , Lian G. , Wang J. 
Published: January 2007

AbstractAs a result of human disturbance and topographic variability, land use mosaics are characteristic of the transition zone of the Loess Plateau in Shaanxi Province, China. Soils are particularly sensitive to change when land degradation processes are dominant. An understanding of the influences of environmental variables is required to inform land management and agricultural production. In this study the relationships between land type, topography and soil properties were analysed for Hengshan County at two different scales using detrended canonical correspondence analysis. The results show that variations in soil properties are strongly influenced by topography, land use and vegetation. Slope, elevation and aspect are also of importance at the county and small catchment scales of analysis. Though land use type proved to be of lesser importance than topographic factors, ANOVA analysis showed that there were significant differences in soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), available nitrogen, available potassium and clay %. Areas under vegetables had significantly higher SOM and TN content at the catchment scale. The results will enhance our ability to predict spatial and temporal changes in soils. In addition, it is shown that soil fertility could be improved by land reform and management in the hilly‐gully area.
Qualitative Data Analysis for Health Services Research: Developing Taxonomy, Themes, and Theory
Authors: Bradley Elizabeth H. , Curry Leslie A. , Devers Kelly J. 
Published: January 2007

Objective. To provide practical strategies for conducting and evaluating analyses of qualitative data applicable for health services researchers.Data Sources and Design. We draw on extant qualitative methodological literature to describe practical approaches to qualitative data analysis. Approaches to data analysis vary by discipline and analytic tradition; however, we focus on qualitative data analysis that has as a goal the generation of taxonomy, themes, and theory germane to health services research.Principle Findings. We describe an approach to qualitative data analysis that applies the principles of inductive reasoning while also employing predetermined code types to guide data analysis and interpretation. These code types (conceptual, relationship, perspective, participant characteristics, and setting codes) define a structure that is appropriate for generation of taxonomy, themes, and theory. Conceptual codes and subcodes facilitate the development of taxonomies. Relationship and perspective codes facilitate the development of themes and theory. Intersectional analyses with data coded for participant characteristics and setting codes can facilitate comparative analyses.Conclusions. Qualitative inquiry can improve the description and explanation of complex, real‐world phenomena pertinent to health services research. Greater understanding of the processes of qualitative data analysis can be helpful for health services researchers as they use these methods themselves or collaborate with qualitative researchers from a wide range of disciplines.
Hospice Care: What Services Do Patients and Their Families Receive?
Authors: Carlson Melissa D. A. , Morrison R. Sean , Holford Theodore R. , Bradley Elizabeth H. 
Published: January 2007

Objective. To determine the degree to which patients and families enrolled with hospice received services across key categories of palliative care, the extent of hospice‐level variability in services delivered, and changes over time in services delivered.Data Source. Nationally representative sample of 9,409 discharged patients from 2,066 hospices in the National Home and Hospice Care Survey.Study Design. Observational, cross‐sectional study conducted from 1992 to 2000. The primary outcome is the receipt of services across five key categories of palliative care: nursing care, physician care, medication management, psychosocial care, and caregiver support.Data Collection. Data were obtained via interview with the hospice staff member most familiar with the patient's care, in conjunction with medical record review.Principle Findings. In 2000, 22 percent of patients enrolled with hospice received services across five key categories of palliative care. There was marked variation across hospices in service delivery. One‐third of hospices provided patients and families services in one or two of the five key categories of palliative care, whereas 14 percent of hospices provided services across five key categories of palliative care. In multivariable analysis, the odds of receiving any additional hospice service was significantly greater in later compared with earlier years (odds ratio=1.10, 95 percent confidence interval 1.01–1.20). Nevertheless, the percentages of patients in 2000 receiving medication management (59 percent), respite care (7 percent), and physician services (30 percent) remained low.Conclusions. Hospice care for patients and families varies substantially across hospices. Whereas some hospices provide services across the key categories of palliative care, other hospices do not provide this breadth of services. Greater understanding of the causes of variation in service delivery as well as its impact on patient and family outcomes and satisfaction with end‐of‐life care is a critical subject for future research. Changes in Medicare's reimbursement policies may help hospices increase the range of services provided to patients and families.
Notes from the Field: Jumpstarting the IRB Approval Process in Multicenter Studies
Authors: Blustein Jan , Regenstein Marsha , Siegel Bruce , Billings John 
Published: January 2007

Objective. To identify strategies that facilitate readiness for local Institutional Review Board (IRB) review, in multicenter studies.Study Setting. Eleven acute care hospitals, as they applied to participate in a foundation‐sponsored quality improvement collaborative.Study Design. Case series.Data Collection/Extraction. Participant observation, supplemented with review of written and oral communications.Principal Findings. Applicant hospitals responded positively to efforts to engage them in early planning for the IRB review process. Strategies that were particularly effective were the provisions of application templates, a modular approach to study description, and reliance on conference calls to collectively engage prospective investigators, local IRB members, and the evaluation/national program office teams. Together, these strategies allowed early identification of problems, clarification of intent, and relatively timely completion of the local IRB review process, once hospitals were selected to participate in the learning collaborative.Conclusions. Engaging potential collaborators in planning for IRB review may help expedite and facilitate review, without compromising the fairness of the grant‐making process or the integrity of human subjects protection.
Time Allocation in Primary Care Office Visits
Authors: Tai‐Seale Ming , McGuire Thomas G. , Zhang Weimin 
Published: January 2007

Objectives. To use an innovative videotape analysis method to examine how clinic time was spent during elderly patients' visits to primary care physicians. Secondary objectives were to identify the factors that influence time allocations.Data Sources. A convenience sample of 392 videotapes of routine office visits conducted between 1998 and 2000 from multiple primary care practices in the United States, supplemented by patient and physician surveys.Research Design. Videotaped visits were examined for visit length and time devoted to specific topics—a novel approach to study time allocation. A survival analysis model analyzed the effects of patient, physician, and physician practice setting on how clinic time was spent.Principal Findings. Very limited amount of time was dedicated to specific topics in office visits. The median visit length was 15.7 minutes covering a median of six topics. About 5 minutes were spent on the longest topic whereas the remaining topics each received 1.1 minutes. While time spent by patient and physician on a topic responded to many factors, length of the visit overall varied little even when contents of visits varied widely. Macro factors associated with each site had more influence on visit and topic length than the nature of the problem patients presented.Conclusions. Many topics compete for visit time, resulting in small amount of time being spent on each topic. A highly regimented schedule might interfere with having sufficient time for patients with complex or multiple problems. Efforts to improve the quality of care need to recognize the time pressure on both patients and physicians, the effects of financial incentives, and the time costs of improving patient–physician interactions.
Factors Associated with the Income Distribution of Full‐Time Physicians: A Quantile Regression Approach
Authors: Shih Ya‐Chen Tina , Konrad Thomas R. 
Published: January 2007

Objective. Physician income is generally high, but quite variable; hence, physicians have divergent perspectives regarding health policy initiatives and market reforms that could affect their incomes. We investigated factors underlying the distribution of income within the physician population.Data Sources. Full‐time physicians (N=10,777) from the restricted version of the 1996–1997 Community Tracking Study Physician Survey (CTS‐PS), 1996 Area Resource File, and 1996 health maintenance organization penetration data.Study Design. We conducted separate analyses for primary care physicians (PCPs) and specialists. We employed least square and quantile regression models to examine factors associated with physician incomes at the mean and at various points of the income distribution, respectively. We accounted for the complex survey design for the CTS‐PS data using appropriate weighted procedures and explored endogeneity using an instrumental variables method.Principal Findings. We detected widespread and subtle effects of many variables on physician incomes at different points (10th, 25th, 75th, and 90th percentiles) in the distribution that were undetected when employing regression estimations focusing on only the means or medians. Our findings show that the effects of managed care penetration are demonstrable at the mean of specialist incomes, but are more pronounced at higher levels. Conversely, a gender gap in earnings occurs at all levels of income of both PCPs and specialists, but is more pronounced at lower income levels.Conclusions. The quantile regression technique offers an analytical tool to evaluate policy effects beyond the means. A longitudinal application of this approach may enable health policy makers to identify winners and losers among segments of the physician workforce and assess how market dynamics and health policy initiatives affect the overall physician income distribution over various time intervals.
The Role of the Intracarotid Amobarbital Procedure in Predicting Verbal Memory Decline after Temporal Lobe Resection
Authors: Baxendale Sallie , Thompson Pamela , Harkness William , Duncan John 
Published: January 2007

Summary:  Purpose: The aim of this study was to compare the utility of baseline neuropsychological measures and scores from the intracarotid amobarbital procedure (IAP) in the prediction of postoperative memory decline in temporal lobe epilepsy surgery patients. Methods: Logistic regression analyses were used to determine the relation between demographic variables, baseline neuropsychological scores, and scores from the IAP (using mixed verbal and nonverbal stimuli) and postoperative deterioration in verbal learning and verbal recall in 91 patients (48 right, RTL; 43 left, LTL) who had undergone a standard anterior temporal lobe resection for the relief of medically intractable epilepsy and who had been followed up 1 year postoperatively. Results: In the RTL group, the IAP scores were not significant predictors of a postoperative decline in verbal learning or recall. In the LTL group, postoperative decline in verbal learning was associated with good preoperative baseline scores, an older age at the time of surgery, and an unexpected asymmetry on the IAP. Baseline neuropsychological scores and scores from the IAP were associated with a significant postoperative decline in verbal recall in the LTL group. Conclusions: Scores from the IAP using mixed stimuli were not helpful in the prediction of postoperative verbal memory decline in RTL patients. The significance of IAP scores in predicting verbal memory deficits in LTL patients may be task specific.
Coronary Sinus and Fossa Ovalis Ablation: Effect on Interatrial Conduction and Atrial Fibrillation
Authors: OTT PETER , KIRK MALCOLM M. , KOO CHARLES , HE DING SHENG , BHATTACHARYA BAISHALI , BUXTON ALFRED 
Published: January 2007

Background: Interatrial conduction occurs via discrete pathways along the coronary sinus musculature, fossa ovalis region, and Bachman's bundle. We assessed the feasibility of altering interatrial conduction by selectively ablating two of these conduction pathways using a novel mesh electrode ablation catheter. Methods: Circular radiofrequency energy catheter ablation lesions were created in the proximal coronary sinus in four dogs and in both the fossa ovalis and the proximal coronary sinus regions in seven pigs. Interatrial conduction was assessed by analyzing intracardiac electrogram and noncontact isopotential mapping data. Inducibility of atrial fibrillation was assessed before and after ablation (in six pigs). Results: Ablation lesions in the proximal coronary sinus eliminated interatrial conduction along the coronary sinus musculature in four dogs and five of seven pigs. Ablation lesions in the fossa ovalis region eliminated interatrial conduction via midseptal pathways in six of seven pigs. Atrial fibrillation, inducible in five of seven pigs at baseline, was rendered noninducible in all five. There was no adverse effect on AV nodal conduction. Conclusions: (1) Using a novel mesh electrode ablation catheter, we were able to ablate interatrial conduction pathways along the proximal coronary sinus and fossa ovalis regions. (2) This altered interatrial conduction and altered atrial fibrillation inducibility and maintenance. (3) Catheter ablation of interatrial conduction pathways may be useful in the therapy of atrial fibrillation.
Anemia management in chronic kidney disease
Authors: GILLESPIE Barbara S. , INRIG Jula K. , SZCZECH Lynda A. 
Published: January 2007

AbstractAnemia is common in chronic kidney disease (CKD) due to a state of erythropoietin deficiency. Erythropoietin therapy has been used for approximately 20 years to correct anemia in CKD and to improve both subjective and objective outcomes. Guidelines that establish a hemoglobin (Hb) goal for anemia correction in CKD patients are largely based on observational data. Controversy still exists, however, because outcomes have not been consistent with various degrees of anemia correction. The number of prospective randomized trials investigating the effects of anemia correction on cardiovascular (CV) morbidity and mortality in CKD patients, an already high‐risk group, is limited. With respect to improving CV outcomes in the CKD population, the currently available trial data caution against raising Hb levels in CKD patients to approach more “normal” physiologic ranges. The disappointing experience with the trial data must be weighed against the beneficial associations of erythropoietin therapy that have been generated from observational data. Establishing the ideal target Hb ranges for anemia correction in CKD patients remains a dynamic process and leaves many gray areas to be further elucidated. Here, we present a case that underscores the need to consider the study design when reviewing the data at a population level in order to determine what is most appropriate for our patient.