bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diffusion of arylpropionate non‐steroidal anti‐inflammatory drugs into the cerebrospinal fluid: a quantitative structure–activity relationship approach
Authors: Péhourcq Fabienne , Matoga Myriam , Bannwarth Bernard 
Published: November 2004

AbstractA quantitative structure–activity relationship (QSAR) analysis of a series of arylpropionic acid non‐steroidal anti‐inflammatory drugs (NSAIDs) has been performed to determine which physicochemical properties of these compounds are involved in their diffusion into the cerebrospinal fluid (CSF). The penetration of eight arylpropionic acid derivatives into CSF was studied in male Wistar rats. After intraperitoneal administration of each compound (5 mg/kg), blood and CSF samples were collected at different times (0.5, 1, 3 and 6 h). The fraction unbound to plasma protein was determined using ultrafiltration. The areas under the curve of the free plasma (AUCF) and CSF (AUCCSF) concentrations were calculated according to the trapezoidal rule. The overall drug transit into CSF was estimated by the ratio RAUC (AUCCSF : AUCF). The lipophilicity was expressed as the chromatographic capacity factor (log kIAM) determined by high‐performance liquid chromatography on an immobilized artificial membrane (IAM) column. A significant parabolic relationship was sought between lipophilicity (log kIAM) and the capacity of diffusion across the blood–brain barrier (log RAUC) (r = 0.928; P < 0.01). The arylpropionic acid NSAIDs exhibiting a lipophilicity value between 1.1 and 1.7 entered the CSF easily (RAUC > 1). The molecular weight (MW) was included in this parabolic relationship by means of a multiple regression analysis. This physicochemical parameter improved the correlation (r = 0.976; P < 0.005). Based on our findings, diffusion of arylpropionic acid NSAIDs into CSF appears to depend primarily on their lipophilicity and MW.
Effects of atipamezole — a selective α2‐adrenoceptor antagonist — on cardiac parasympathetic regulation in human subjects
Authors: Penttilä J. , Kaila T. , Helminen A. , Anttila M. , Karhuvaara S. , Huhtala S. , Scheinin H. 
Published: November 2004

Summary 1 This double‐blind, cross‐over, placebo‐controlled study on six healthy male volunteers was designed to evaluate the effects of α2‐adrenoceptor antagonism on cardiac parasympathetic regulation. 2 The subjects received atipamezole intravenously as a three‐step infusion, which aimed at steady‐state serum concentrations of 10, 30 and 90 ng ml−1 at 50‐min intervals. 3 Drug effects were assessed with repeated recordings of blood pressure and electrocardiogram, in which the high‐frequency (0.15–0.40 Hz) R‐R interval variation is supposed to reflect cardiac parasympathetic efferent neuronal activity. 4 At the end of the three steps of the infusion, the mean (±SD) concentrations of atipamezole were 10.5 (3.9), 26.8 (5.6) and 81.3 (21.1) ng ml−1. 5 Within this concentration range, atipamezole appeared to reduce slightly the high‐frequency R‐R interval fluctuations, indicating a minor vagolytic effect in the heart. 6 Atipamezole increased systolic and diastolic arterial pressure, on average by 20 and 14 mmHg (maxima at the second step of the infusion), which evidently reflects an overall sympathetic augmentation.
Comparison of noradrenaline and lysosphingolipid‐induced vasoconstriction in mouse and rat small mesenteric arteries
Authors: Hedemann J. , Fetscher C. , Michel M. C. 
Published: November 2004

Summary 1 We have compared vasoconstriction responses in isolated mesenteric small arteries from mice and rats as elicited by KCl, noradrenaline and the lysosphingolipids sphingosine‐1‐phosphate (S1P) and sphingosylphosphorylcholine (SPC). 2 Contractile responses to KCl and noradrenaline, but not those of S1P or SPC, were significantly related to vessel diameter in both species. 3 When comparing vessels of similar diameter, contractile responses for KCl and the three agonists were much smaller in mice than in rats, e.g. 8.3 ± 0.4 vs. 14.7 ± 0.7 mn for noradrenaline. 4 Based upon the antagonist rank order of potency of prazosin (pKB 8.80) > B8805‐033 (pKB 7.89) > yohimbine (pKB 6.18) ≈ BMY 7378 (pA2 6.03), noradrenaline responses in mice were mediated solely via α1A‐adrenoceptors, similar to what repeatedly has been shown in rats. 5 The S1P3 receptor antagonist suramin (100 μm) significantly inhibited responses to S1P and SPC in rats but not in mice, and did not affect noradrenaline responses in either species. 6 We conclude that for any given diameter, mouse mesenteric arteries develop less contraction in response to various stimuli. Noradrenaline acts via α1A‐adrenoceptors in both species. Responses to S1P and SPC differ between both species with regard to suramin‐sensitivity indicating involvement of different receptor subtypes for lysosphingolipids in both species.
Between air and water: the plunge dive of the Cape Gannet Morus capensis
Authors: Ropert‐Coudert Yan , Grémillet David , Ryan Peter , Kato Akiko , Naito Yasuhiko , Le Maho Yvon 
Published: November 2004

Gannets have one of the most spectacular prey‐capture behaviours of all marine predators, plummeting from up to 30 m into the water, where they seize fish with their razor‐sharp beaks. However, there is little detailed information on this brief behaviour. In January and December 2002, we monitored the biomechanics of plunge diving in 25 free‐ranging Cape Gannets Morus capensis using a recently developed, rapid‐sampling acceleration and depth recorder. Our data provide the first detailed description of this highly specialized foraging technique. We recorded no or a very low deceleration when Gannets entered the water, which underlines the remarkable streamlining of this large bird. Birds use their momentum to travel underwater at an average descent rate of 2.87 m/s (sd = ±1.53) before actively braking once they attain the desired depth (range 0.3–9.7 m). We show that Gannets sometimes used either their wings or feet for underwater propulsion during the course of 9.4% of the dives that had undulations in their depth profiles. After chasing prey, birds developed an upward momentum before gliding passively back to the surface, making use of their buoyancy to complete the dive at the lowest possible energy cost.
Relationships between home‐range size, sex and season with reference to the mating system of the Houbara Bustard Chlamydotis undulata undulata
Authors: Hingrat Yves , Jalme Michel Saint , Ysnel Frédéric , Lacroix Fredéric , Seabury John , Rautureau Pierrick 
Published: November 2004

This paper presents observations of Houbara Bustard Chlamydotis undulata undulata home‐range, in the semi‐desert steppe of eastern Morocco. Home‐ranges were calculated from radiotagged birds using the fixed kernel method (LSCV). The mean annual home‐range of males (17 km2) was smaller than that of females (146 km2; P < 0.001). The majority of male home‐ranges had a unimodal distribution (86%), whereas 67% of female home‐ranges were multimodal. Consequently, the amplitude of female movements was larger (mean: 44 km/13 km; P < 0.002). In spring, male home‐ranges decreased in size around display sites (8 km2) and many of them overlapped considerably. Display sites show an aggregative distribution (P < 0.001) and a single female reproductive range may contain the display sites of several males. The data fulfil the definition of an exploded lek social structure. In our study, C. u. undulata appears to be sedentary with relatively limited home‐ranges. Successive years of fidelity to home‐ranges indicate that adults are not nomadic.
A combinatorial auction improves school meals in Chile: a case of OR in developing countries
Authors: Epstein Rafael , Henríquez Lysette , Catalán Jaime , Weintraub Gabriel Y. , Martínez Cristián , Espejo Francisco 
Published: November 2004

AbstractThe Chilean State delivers essential meal services at schools for low‐income students. Junta Nacional de Auxilio Escolar y Becas, the institution in charge of covering 1,300,000 children, leases the meal service to private enterprises. We developed an integer linear programming model to assign the meal contracts, in a process known as combinatorial auctions. The resulting model, which is NP‐hard, led to significant improvements in efficiency and also contributed to making the process more transparent. The results are apparent in substantial improvements in quality and coverage of the service, and important savings to the country, which are equivalent to feeding 300,000 children in addition. We developed techniques to solve the combinatorial models and also to analyze and compare multiple scenarios to find robust solutions. For the objective function of this problem, we analyzed several options to consider different kinds of social benefits. In this paper, we describe the problem, the methodology and the results. We also present empirical results based on 6 years of experience. Finally, we discuss the relevance and impact of using operations research in these central issues in developing countries.
Network service scheduling and routing
Authors: Groves G. , Le Roux J. , Van Vuuren J. H. 
Published: November 2004

AbstractReal‐life vehicle routing problems generally have both routing and scheduling aspects to consider. Although this fact is well acknowledged, few heuristic methods exist that address both these complicated aspects simultaneously. We present a graph theoretic heuristic to determine an efficient service route for a single service vehicle through a transportation network that requires a subset of its edges to be serviced, each a specified (potentially different) number of times. The times at which each of these edges are to be serviced should additionally be as evenly spaced over the scheduling time window as possible, thus introducing a scheduling consideration to the problem. Our heuristic is based on the tabu search method, used in conjunction with various well‐known graph theoretic algorithms, such as those of Floyd (for determining shortest routes) and Frederickson (for solving the rural postman problem). This heuristic forms the backbone of a decision support system that prompts the user for certain parameters from the physical situation (such as the service frequencies and travel times for each network link as well as bounds in terms of acceptability of results) after which a service routing schedule is suggested as output. The decision support system is applied to a special case study, where a service routing schedule is sought for the South African national railway system by Spoornet (the semi‐privatised South African national railways authority and service provider) as part of their rationalisation effort, in order to remain a lucrative company.
Logistics of tractor distribution in an agriculture‐driven economy: an Indian case study
Authors: Raghuram G. 
Published: November 2004

AbstractThis paper examines critical decision areas in the context of outbound logistics and their analytical resolution (using operational research models) for a tractor company, which was among the market leaders in the tractor industry in India. Customer preferences and demands had changed in the context of the competitive environment. The challenges lay in increasing service levels to the customer through improvements in supply chain management and supporting infrastructure. Apart from value through improved service levels, cost savings of Rs 22 million per year (benchmarked against a profit before tax of Rs 1 billion per year) could be extracted through a better distribution structure involving a new central despatch yard and revised stockyard locations.
Physical and Sensory Functioning over Time and Satisfaction with Care: The Implications of Getting Better or Getting Worse
Authors: Iezzoni Lisa I. , Davis Roger B. , Soukup Jane , O'Day Bonnie 
Published: November 2004

Objective. To determine whether those persons whose sensory or physical functioning improved or worsened over one year are more or less satisfied with their health care.Data Sources. 1996 and 1997 Medicare Current Beneficiary Survey (MCBS).Study Design. The MCBS surveys a nationally representative, longitudinal panel of Medicare beneficiaries about their sociodemographic attributes; vision, hearing, and various mobility functions; and 10 items representing satisfaction with and access to health care. Using multivariable logistic regression and controlling for sociodemographic factors, we computed adjusted odds ratios of dissatisfaction with care, examining the effects of changes in sensory or physical functioning. Analyses accounted for MCBS sampling weights.Data Extraction Methods. We identified 9,974 community‐dwelling respondents, 18 years old and over who answered the 1996 and 1997 MCBS. We assessed five categories of sensory or physical functioning (vision; hearing; walking; reaching overhead; and grasping and writing) and compared 1996 and 1997 responses to identify those whose functioning improved or worsened.Principal Findings. Worsened functioning was strongly associated with older age, low income, and low educational attainment. Improved functioning was rarely significantly associated with satisfaction; an exception involved substantially lower rates of dissatisfaction with “ease and convenience” of getting to physicians. Worsened functioning was often statistically significantly associated with dissatisfaction, always with adjusted odds ratios >1.0. Across all five functional categories, persons whose functioning worsened displayed significantly greater dissatisfaction with overall quality, ease, and costs or care.Conclusions. Persons whose functioning improved rarely reported better satisfaction than did those whose functioning did not improve, while those whose functioning worsened expressed more systematic reservations about their care.
Elevated Depressive Symptoms among Caregiving Grandparents
Authors: Blustein Jan , Chan Sewin , Guanais Frederico C 
Published: November 2004

Objective. To determine whether caregiving grandparents are at an increased risk for depressive symptoms.Data Source. National sample (n=10,293) of grandparents aged 53–63 years in 1994, and their spouse/partners, who took part in the Health and Retirement Study (HRS).Study Design. Grandparents were surveyed in 1994 and resurveyed every two years thereafter, through 2000. Over that period, 977 had a grandchild move in or out of their home. These grandparents served as their own controls to assess the impact of having a grandchild in the home.Data Extraction. Depressive symptoms were measured using an abbreviated form of the Center for Epidemiologic Studies—Depression (CES‐D) scale, scored 1–8, with a score ≥4 associated with depression “caseness.”Principal Findings. At the time of the 1994 interview, 8.2 percent of grandparents had a grandchild in their home. However, there was substantial variation across demographic groups (e.g., 29.4 percent of single nonwhite grandmothers, but only 2.0 percent of single white grandfathers had a grandchild in residence). The impact of having a grandchild in the home varied by grandparent demographic group, with single grandparents and those without coresident adult children experiencing the greatest probability of elevation in depressive symptoms when a grandchild was in residence. For example, single nonwhite grandmothers experienced an 8 percentage point increase in the probability of having a CES‐D score ≥4 when a grandchild was in their home, compared to when a grandchild was not in their home, controlling for changes in health care, income, and household composition over time (95 percent CI=0.1 to 15.0 percentage points).Conclusions. Grandparents have a greater probability of elevated depressive symptoms when a grandchild is in their home, versus when a grandchild is not in their home. Single women of color bear a disproportionate burden of the depression associated with caring for grandchildren. Since an increasing number of grandparents function as a de facto safety net keeping their grandchildren out of formal foster care, identifying strategies to support the health and well‐being of caregiving grandparents is an emerging priority.
Predicting Lawsuits against Nursing Homes in the United States, 1997–2001
Authors: Johnson Christopher E. , Dobalian Aram , Burkhard Janet , Hedgecock Deborah K. , Harman Jeffrey 
Published: November 2004

Objectives. To examine how nursing home characteristics impacted the number of lawsuits filed against the facilities in the United States during 1997–2001.Data Sources/Study Setting. A stratified random sample of 2,378 nursing home in 45 states from 1997–2001. Data were obtained from Westlaw's Adverse Filings: Lawsuits database, the Centers for Medicare and Medicaid Services' (CMS) Online Survey, Certification, and Reporting (OSCAR) database, state complaint surveys, and through primary data.Study Design. Negative binomial regression was used to explain total lawsuit variance by year. Explanatory variables included (a) facility characteristics—including staffing, number of beds, multistate system membership, for‐profit ownership, (b) quality indicators—including total number and type of quality survey deficiencies, pressure sore development, and (c) market area—state has resident rights statutes, state complaint information. Resident acuity levels and year effects were controlled for.Data Collection/Extraction Methods. Nursing homes were identified and linked to Westlaw data that was searched for the number of lawsuits filed against the home, and then linked to OSCAR data and a primary data analysis of multistate chain membership.Principal Findings. Staffing levels for certified nursing assistants (CNAs) and registered nurses (RNs) and multistate chain membership were negatively related with higher numbers of lawsuits. More deficiencies on the licensing survey, larger, for‐profit nursing homes, and being located in resident rights states were positively related with higher numbers of lawsuits.Conclusion. This study suggests that nursing homes that meet long‐stay staffing standards and minimum quality indicators, are nonprofit, smaller, and not located in resident rights states will experience fewer lawsuits.
Specificity and Sensitivity of Claims‐Based Algorithms for Identifying Members of Medicare+Choice Health Plans That Have Chronic Medical Conditions
Authors: Rector Thomas S. , Wickstrom Steven L. , Shah Mona , Thomas Greeenlee N. , Rheault Paula , Rogowski Jeannette , Freedman Vicki , Adams John , Escarce José J. 
Published: November 2004

Objective. To examine the effects of varying diagnostic and pharmaceutical criteria on the performance of claims‐based algorithms for identifying beneficiaries with hypertension, heart failure, chronic lung disease, arthritis, glaucoma, and diabetes.Study Setting. Secondary 1999–2000 data from two Medicare+Choice health plans.Study Design. Retrospective analysis of algorithm specificity and sensitivity.Data Collection. Physician, facility, and pharmacy claims data were extracted from electronic records for a sample of 3,633 continuously enrolled beneficiaries who responded to an independent survey that included questions about chronic diseases.Principal Findings. Compared to an algorithm that required a single medical claim in a one‐year period that listed the diagnosis, either requiring that the diagnosis be listed on two separate claims or that the diagnosis to be listed on one claim for a face‐to‐face encounter with a health care provider significantly increased specificity for the conditions studied by 0.03 to 0.11. Specificity of algorithms was significantly improved by 0.03 to 0.17 when both a medical claim with a diagnosis and a pharmacy claim for a medication commonly used to treat the condition were required. Sensitivity improved significantly by 0.01 to 0.20 when the algorithm relied on a medical claim with a diagnosis or a pharmacy claim, and by 0.05 to 0.17 when two years rather than one year of claims data were analyzed. Algorithms that had specificity more than 0.95 were found for all six conditions. Sensitivity above 0.90 was not achieved all conditions.Conclusions. Varying claims criteria improved the performance of case‐finding algorithms for six chronic conditions. Highly specific, and sometimes sensitive, algorithms for identifying members of health plans with several chronic conditions can be developed using claims data.
Impacts of Informal Caregiver Availability on Long‐term Care Expenditures in OECD Countries
Authors: Yoo Byung‐Kwang , Bhattacharya Jay , McDonald Kathryn M. , Garber Alan M. 
Published: November 2004

Objective. To quantify the effects of informal caregiver availability and public funding on formal long‐term care (LTC) expenditures in developed countries.Data Source/Study Setting. Secondary data were acquired for 15 Organization for Economic Cooperation and Development (OECD) countries from 1970 to 2000.Study Design. Secondary data analysis, applying fixed‐ and random‐effects models to time‐series cross‐sectional data. Outcome variables are inpatient or home heath LTC expenditures. Key explanatory variables are measures of the availability of informal caregivers, generosity in public funding for formal LTC, and the proportion of the elderly population in the total population.Data Collection/Extraction Method. Aggregated macro data were obtained from OECD Health Data, United Nations Demographic Yearbooks, and U.S. Census Bureau International Data Base.Principal Findings. Most of the 15 OECD countries experienced growth in LTC expenditures over the study period. The availability of a spouse caregiver, measured by male‐to‐female ratio among the elderly, is associated with a $28,840 (1995 U.S. dollars) annual reduction in formal LTC expenditure per additional elderly male. Availability of an adult child caregiver, measured by female labor force participation and full‐time/part‐time status shift, is associated with a reduction of $310 to $3,830 in LTC expenditures. These impacts on LTC expenditure vary across countries and across time within a country.Conclusions. The availability of an informal caregiver, particularly a spouse caregiver, is among the most important factors explaining variation in LTC expenditure growth. Long‐term care policies should take into account behavioral responses: decreased public funding in LTC may lead working women to leave the labor force to provide more informal care.