269 research outputs found

    Evaluation of binomial double sums involving absolute values

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    We show that double sums of the form i,j=nnisjt(ikjk)β(2nn+i)(2nn+j) \sum_{i,j=-n} ^{n} |i^sj^t(i^k-j^k)^\beta| \binom {2n} {n+i} \binom {2n} {n+j} can always be expressed in terms of a linear combination of just four functions, namely (4n2n)\binom {4n}{2n}, (2nn)2{\binom {2n}n}^2, 4n(2nn)4^n\binom {2n}n, and 16n16^n, with coefficients that are rational in nn. We provide two different proofs: one is algorithmic and uses the second author's computer algebra package Sigma; the second is based on complex contour integrals. In many instances, these results are extended to double sums of the above form where (2nn+j)\binom {2n}{n+j} is replaced by (2mm+j)\binom {2m}{m+j} with independent parameter mm.Comment: AmS-LaTeX, 42 pages; substantial revision: several additional and more general results, see Proposition 11 and Theorems 15-1

    Ecological knowledge, leadership, and the evolution of menopause in killer whales

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    This is the final version of the article. Available from Elsevier via the DOI in this record.There is another record in ORE for this publication: http://hdl.handle.net/10871/16488Classic life-history theory predicts that menopause should not occur because there should be no selection for survival after the cessation of reproduction [1]. Yet, human females routinely live 30 years after they have stopped reproducing [2]. Only two other species-killer whales (Orcinus orca) and short-finned pilot whales (Globicephala macrorhynchus) [3, 4]-have comparable postreproductive lifespans. In theory, menopause can evolve via inclusive fitness benefits [5, 6], but the mechanisms by which postreproductive females help their kin remain enigmatic. One hypothesis is that postreproductive females act as repositories of ecological knowledge and thereby buffer kin against environmental hardships [7, 8]. We provide the first test of this hypothesis using a unique long-term dataset on wild resident killer whales. We show three key results. First, postreproductively aged females lead groups during collective movement in salmon foraging grounds. Second, leadership by postreproductively aged females is especially prominent in difficult years when salmon abundance is low. This finding is critical because salmon abundance drives both mortality and reproductive success in resident killer whales [9, 10]. Third, females are more likely to lead their sons than they are to lead their daughters, supporting predictions of recent models [5] of the evolution of menopause based on kinship dynamics. Our results show that postreproductive females may boost the fitness of kin through the transfer of ecological knowledge. The value gained from the wisdom of elders can help explain why female resident killer whales and humans continue to live long after they have stopped reproducing.This research was funded by a Natural Environment Research Council grant (NE/K01286X/1) to D.P.C., D.W.F., and M.A.C

    BRIEF REPORT: Brief Instrument to Assess Geriatrics Knowledge of Surgical and Medical Subspecialty House Officers

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    Initiatives are underway to increase geriatrics training in nonprimary care disciplines. However, no validated instrument exists to measure geriatrics knowledge of house officers in surgical specialties and medical subspecialties. METHODS : A 23-item multiple-choice test emphasizing inpatient care and common geriatric syndromes was developed through expert panels and pilot testing, and administered to 305 residents and fellows at 4 institutions in surgical disciplines (25% of respondents), emergency medicine (29%), medicine subspecialties (19%), internal medicine (12%), and other disciplines (15%). RESULTS : Three items decreased internal reliability. The remaining 20 items covered 17 topic areas. Residents averaged 62% correct on the test. Internal consistency was appropriate (Cronbach's Α coefficient=0.60). Validity was supported by the use of expert panels to develop content, and by overall differences in scores by level of training ( P <.0001) and graded improvement in test performance, with 58%, 63%, 62%, and 69% correct responses among HO1, HO2, HO3, and HO4s, respectively. CONCLUSIONS : This reliable, valid measure of clinical geriatrics knowledge can be used by a wide variety of surgical and medical graduate medical education programs to guide curriculum reform or evaluate program performance to meet certification requirements. The instrument is now available on the web.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73902/1/j.1525-1497.2006.00433.x.pd

    Childhood tuberculosis deskguide and monitoring: An intervention to improve case management in Pakistan

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    Background: Childhood tuberculosis (TB) has been a neglected area in national TB control programme (NTCP) in high burden countries. The NTP Pakistan adapted the global approaches by developing and piloting its policy guideline on childhood TB in ten districts of the country. We developed an intervention package including a deskguide and a monitoring tool and tested with the ongoing childhood TB care in a district. The objective of our study was to measure effectiveness of intervention package with deskguide and monitoring tool by comparing TB case finding and treatment outcomes among districts in 2008, and performance assessment in intervention district. Method: An intervention study with cohort design within a routine TB control programme comparing case findings and treatment outcomes before and after the intervention, and in districts with and without intervention. We enrolled all children below 15 years registered at all nine public sector hospitals in three districts of Pakistan. The data was collected from hospital TB records. Results: In eight months during 2007 there were 164 childhood TB cases notified, and after intervention in 2008 a total of 194 cases were notified. In intervention district case finding doubled (110% increase) and correct treatment practice significantly increased in eight months. Successful outcomes were significantly higher in intervention district (37,100%) compared to control district A (18, 18%, p < 0.05) and control district B (41, 72%, p < 0.05). Conclusion: Childhood TB deskguide and structured monitoring was associated with improved case management and it augmented NTP policy. More development and implementation in all health services of the district are indicated.publishedVersio

    The AQUA-FONTIS study: protocol of a multidisciplinary, cross-sectional and prospective longitudinal study for developing standardized diagnostics and classification of non-thyroidal illness syndrome

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    <p>Abstract</p> <p>Background</p> <p>Non-thyroidal illness syndrome (NTIS) is a characteristic functional constellation of thyrotropic feedback control that frequently occurs in critically ill patients. Although this condition is associated with significantly increased morbidity and mortality, there is still controversy on whether NTIS is caused by artefacts, is a form of beneficial adaptation, or is a disorder requiring treatment. Trials investigating substitution therapy of NTIS revealed contradictory results. The comparison of heterogeneous patient cohorts may be the cause for those inconsistencies.</p> <p>Objectives</p> <p>Primary objective of this study is the identification and differentiation of different functional states of thyrotropic feedback control in order to define relevant evaluation criteria for the prognosis of affected patients. Furthermore, we intend to assess the significance of an innovative physiological index approach (SPINA) in differential diagnosis between NTIS and latent (so-called "sub-clinical") thyrotoxicosis.</p> <p>Secondary objective is observation of variables that quantify distinct components of NTIS in the context of independent predictors of evolution, survival or pathophysiological condition and influencing or disturbing factors like medication.</p> <p>Design</p> <p>The <b>a</b>pproach to a <b>qua</b>ntitative <b>f</b>ollow-up <b>o</b>f <b>n</b>on-<b>t</b>hyroidal <b>i</b>llness <b>s</b>yndrome (AQUA FONTIS study) is designed as both a cross-sectional and prospective longitudinal observation trial in critically ill patients. Patients are observed in at least two evaluation points with consecutive assessments of thyroid status, physiological and clinical data in additional weekly observations up to discharge. A second part of the study investigates the neuropsychological impact of NTIS and medium-term outcomes.</p> <p>The study design incorporates a two-module structure that covers a reduced protocol in form of an observation trial before patients give informed consent. Additional investigations are performed if and after patients agree in participation.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov NCT00591032</p

    Phenomenological Implications of Deflected Mirage Mediation: Comparison with Mirage Mediation

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    We compare the collider phenomenology of mirage mediation and deflected mirage mediation, which are two recently proposed "mixed" supersymmetry breaking scenarios motivated from string compactifications. The scenarios differ in that deflected mirage mediation includes contributions from gauge mediation in addition to the contributions from gravity mediation and anomaly mediation also present in mirage mediation. The threshold effects from gauge mediation can drastically alter the low energy spectrum from that of pure mirage mediation models, resulting in some cases in a squeezed gaugino spectrum and a gluino that is much lighter than other colored superpartners. We provide several benchmark deflected mirage mediation models and construct model lines as a function of the gauge mediation contributions, and discuss their discovery potential at the LHC.Comment: 29 pages, 9 figure

    Optimizing care in osteoporosis: The Canadian quality circle project

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    <p>Abstract</p> <p>Background</p> <p>While the Osteoporosis Canada 2002 Canadian guidelines provided evidence based strategies in preventing, diagnosing, and managing this condition, publication and distribution of guidelines have not, in and of themselves, been shown to alter physicians clinical approaches. We hypothesize that primary care physicians enrolled in the Quality Circle project would change their patient management of osteoporosis in terms of awareness of osteoporosis risk factors and bone mineral density testing in accordance with the guidelines.</p> <p>Methods</p> <p>The project consisted of five Quality Circle phases that included: 1) Training & Baseline Data Collection, 2) First Educational Intervention & First Follow-Up Data Collection 3) First Strategy Implementation Session, 4) Final Educational Intervention & Final Follow-up Data Collection, and 5) Final Strategy Implementation Session. A total of 340 circle members formed 34 quality circles and participated in the study. The generalized estimating equations approach was used to model physician awareness of risk factors for osteoporosis and appropriate utilization of bone mineral density testing pre and post educational intervention (first year of the study). Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated.</p> <p>Results</p> <p>After the 1<sup>st </sup>year of the study, physicians' certainty of their patients' risk factor status increased. Certainty varied from an OR of 1.4 (95% CI: 1.1, 1.8) for prior vertebral fracture status to 6.3 (95% CI: 2.3, 17.9) for prior hip fracture status. Furthermore, bone mineral density testing increased in high risk as compared with low risk patients (OR: 1.4; 95% CI: 1.2, 1.7).</p> <p>Conclusion</p> <p>Quality Circle methodology was successful in increasing both physicians' awareness of osteoporosis risk factors and appropriate bone mineral density testing in accordance with the 2002 Canadian guidelines.</p

    High caseload of childhood tuberculosis in hospitals on Java Island, Indonesia: a cross sectional study

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    Background Childhood tuberculosis (TB) has been neglected in the fight against TB. Despite implementation of Directly Observed Treatment Shortcourse (DOTS) program in public and private hospitals in Indonesia since 2000, the burden of childhood TB in hospitals was largely unknown. The goals of this study were to document the caseload and types of childhood TB in the 0-4 and 5-14 year age groups diagnosed in DOTS hospitals on Java Island, Indonesia. Methods Cross-sectional study of TB cases recorded in inpatient and outpatient registers of 32 hospitals. Cases were analyzed by hospital characteristics, age groups, and types of TB. The number of cases reported in the outpatient unit was compared with that recorded in the TB register. Results Of 5,877 TB cases in the inpatient unit and 15,694 in the outpatient unit, 11% (648) and 27% (4,173) respectively were children. Most of the childhood TB cases were under five years old (56% and 53% in the inpatient and outpatient clinics respectively). The proportion of smear positive TB was twice as high in the inpatient compared to the outpatient units (15.6% vs 8.1%). Extra-pulmonary TB accounted for 15% and 6% of TB cases in inpatient and outpatient clinics respectively. Among children recorded in hospitals only 1.6% were reported to the National TB Program. Conclusion In response to the high caseload and gross under-reporting of childhood TB cases, the National TB Program should give higher priority for childhood TB case management in designated DOTS hospitals. In addition, an international guidance on childhood TB recording and reporting and improved diagnostics and standardized classification is require
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