1,408 research outputs found

    osp(1,2)-covariant Lagrangian quantization of irreducible massive gauge theories with generic background configurations

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    In the framework of osp(1,2)-symmetric quantization of irreducible massive gauge theories the background field method is studied for the simplest case of a linear splitting of the gauge field into a background configuration and the quantum fluctuations. The symmetries of that approach - including three types of background-dependent gauge transformations - are expressed by Ward identities. From these identities together with the equations of motion of the auxiliary field the background dependence of the vertex functions and of the Greens functions is determined. It is proven that the introduction of a background field does not change the ultraviolet asymptotics of the theory.Comment: 35 pages, AMSTEX; added are two Appendices with proof that the presented solutions in Sect. 4 and 5 are the most general ones; partly rewritten Introduction and Conclusion; change of Reference

    Study of the music preferences of preschool children : an examination of the effects of the learning environment on the extension of listening parameters

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    BACKGROUND: There is no consensus regarding resection of the primary tumour with few or absent symptoms in patients with synchronous unresectable metastatic colorectal cancer (CRC). A potential benefit of resection of the primary tumour is to prevent complications of the primary tumour in later stages of the disease. We here propose a randomized trial in order to demonstrate that resection of the primary tumour improves overall survival. METHODS/DESIGN: The CAIRO4 study is a multicentre, randomized, phase III study of the Dutch Colorectal Cancer Group (DCCG). Patients with synchronous unresectable metastases of CRC and few or absent symptoms of the primary tumour are randomized 1:1 between systemic therapy only, and resection of the primary tumour followed by systemic therapy. Systemic therapy will consist of fluoropyrimidine-based chemotherapy in combination with bevacizumab. The primary objective of this study is to determine the clinical benefit in terms of overall survival of initial resection of the primary tumour. Secondary endpoints include progression free survival, surgical morbidity, quality of life and the number of patients requiring resection of the primary tumour in the control arm. DISCUSSION: The CAIRO4 study is a multicentre, randomized, phase III study that will assess the benefit of resection of the primary tumour in patients with synchronous metastatic CRC. TRIAL REGISTRATION: The CAIRO4 study is registered at clinicaltrials.gov (NCT01606098)

    Structure functions in the polarized Drell-Yan processes with spin-1/2 and spin-1 hadrons: I. general formalism

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    We discuss general formalism for the structure functions which can be investigated in the polarized Drell-Yan processes with spin-1/2 and spin-1 hadrons. To be specific, the formalism can be applied to the proton-deuteron Drell-Yan processes. Because of the spin-1 nature, there are new structure functions which cannot be studied in the proton-proton reactions. Imposing Hermiticity, parity conservation, and time-reversal invariance, we find that 108 structure functions exist in the Drell-Yan processes. However, the number reduces to 22 after integrating the cross section over the virtual-photon transverse momentum Q_T or after taking the limit Q_T->0. There are 11 new structure functions in addition to the 11 ones in the Drell-Yan processes of spin-1/2 hadrons. The additional structure functions are associated with the tensor structure of the spin-1 hadron, and they could be measured by quadrupole spin asymmetries. For example, the structure functions exist for "intermediate" polarization although their contributions vanish in the longitudinal and transverse polarization reactions. We show a number of spin asymmetries for extracting the polarized structure functions. The proton-deuteron reaction may be realized in the RHIC-Spin project and other future ones, and it could be a new direction of next generation high-energy spin physics.Comment: 16 pages, REVTeX, amsmath.sty, epsfig.sty, revtex.cls, 6 eps figures. Submitted for publication. Complete postscript file is available at http://www2.cc.saga-u.ac.jp/saga-u/riko/physics/quantum1/structure.html Email: [email protected], [email protected]

    Distinct pathophysiological pathways in women and men with heart failure

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    Aims: Clinical differences between women and men have been described in heart failure (HF). However, less is known about the underlying pathophysiological mechanisms. In this study, we compared multiple circulating biomarkers to gain better insights into differential HF pathophysiology between women and men. Methods and Results: In 537 women and 1485 men with HF, we compared differential expression of a panel of 363 biomarkers. Then, we performed a pathway over-representation analysis to identify differential biological pathways in women and men. Findings were validated in an independent HF cohort (575 women, 1123 men). In both cohorts, women were older and had higher ejection fraction (LVEF). In the index and validation cohorts respectively, we found 14/363 and 12/363 biomarkers that were relatively up-regulated in women, while 21/363 and 14/363 were up-regulated in men. In both cohorts, the strongest up-regulated biomarkers in women were leptin and fatty acid binding protein-4, compared to matrix metalloproteinase-3 in men. Similar findings were replicated in a subset of patients from both cohorts matched by age and LVEF. Pathway over-representation analysis revealed increased activity of pathways associated with lipid metabolism in women, and neuroinflammatory response in men (all p < 0.0001). Conclusion: In two independent cohorts of HF patients, biomarkers associated with lipid metabolic pathways were observed in women, while biomarkers associated with neuro-inflammatory response were more active in men. Differences in inflammatory and metabolic pathways may contribute to sex differences in clinical phenotype observed in HF, and provide useful insights towards development of tailored HF therapies

    National consensus on a new resectability classification for perihilar cholangiocarcinoma - A modified Delphi method

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    Background: Currently, no practical definition of potentially resectable, borderline or unresectable perihilar cholangiocarcinoma (pCCA) is available. Aim of this study was to define criteria to categorize patients for use in a future neoadjuvant or induction therapy study. Method: Using the modified DELPHI method, hepatobiliary surgeons from all tertiary referral centers in the Netherlands were invited to participate in this study. During five online meetings, predefined factors determining resectability and additional factors regarding surgical resectability and operability were discussed. Results: The five online meetings resulted in 52 statements. After two surveys, consensus was reached in 63% of the questions. The main consensus included a definition regarding potential resectability. 1) Clearly resectable: no vascular involvement (≤90°) of the future liver remnant (FLR) and expected feasibility of radical biliary resection. 2) Clearly unresectable: non-reconstructable venous and/or arterial involvement of the FLR or no feasible radical biliary resection. 3) Borderline resectable: all patients between clearly resectable and clearly unresectable disease. Conclusion: This DELPHI study resulted in a practical and applicable resectability, or more accurate, an explorability classification, which can be used to categorize patients for use in future neoadjuvant therapy studies.</p

    Distinct pathophysiological pathways in women and men with heart failure

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    Aims Clinical differences between women and men have been described in heart failure (HF). However, less is known about the underlying pathophysiological mechanisms. In this study, we compared multiple circulating biomarkers to gain better insights into differential HF pathophysiology between women and men. Methods and results In 537 women and 1485 men with HF, we compared differential expression of a panel of 363 biomarkers. Then, we performed a pathway over-representation analysis to identify differential biological pathways in women and men. Findings were validated in an independent HF cohort (575 women, 1123 men). In both cohorts, women were older and had higher left ventricular ejection fraction (LVEF). In the index and validation cohorts respectively, we found 14/363 and 12/363 biomarkers that were relatively up-regulated in women, while 21/363 and 14/363 were up-regulated in men. In both cohorts, the strongest up-regulated biomarkers in women were leptin and fatty acid binding protein-4, compared to matrix metalloproteinase-3 in men. Similar findings were replicated in a subset of patients from both cohorts matched by age and LVEF. Pathway over-representation analysis revealed increased activity of pathways associated with lipid metabolism in women, and neuro-inflammatory response in men (all p &lt; 0.0001). Conclusion In two independent cohorts of HF patients, biomarkers associated with lipid metabolic pathways were observed in women, while biomarkers associated with neuro-inflammatory response were more active in men. Differences in inflammatory and metabolic pathways may contribute to sex differences in clinical phenotype observed in HF, and provide useful insights towards development of tailored HF therapies.</p

    Exploring the Partonic Structure of Hadrons through the Drell-Yan Process

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    The Drell-Yan process is a standard tool for probing the partonic structure of hadrons. Since the process proceeds through a quark-antiquark annihilation, Drell-Yan scattering possesses a unique ability to selectively probe sea distributions. This review examines the application of Drell-Yan scattering to elucidating the flavor asymmetry of the nucleon's sea and nuclear modifications to the sea quark distributions in unpolarized scattering. Polarized beams and targets add an exciting new dimension to Drell-Yan scattering. In particular, the two initial-state hadrons give Drell-Yan sensitivity to chirally-odd transversity distributions.Comment: 23 pages, 9 figures, to appear in J. Phys. G, resubmission corrects typographical error

    Age dependent associations of risk factors with heart failure:pooled population based cohort study

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    OBJECTIVE: To assess age differences in risk factors for incident heart failure in the general population. DESIGN: Pooled population based cohort study. SETTING: Framingham Heart Study, Prevention of Renal and Vascular End-stage Disease Study, and Multi-Ethnic Study of Atherosclerosis. PARTICIPANTS: 24 675 participants without a history of heart failure stratified by age into young (<55 years; n=11 599), middle aged (55-64 years; n=5587), old (65-74 years; n=5190), and elderly (≥75 years; n=2299) individuals. MAIN OUTCOME MEASURE: Incident heart failure. RESULTS: Over a median follow-up of 12.7 years, 138/11 599 (1%), 293/5587 (5%), 538/5190 (10%), and 412/2299 (18%) of young, middle aged, old, and elderly participants, respectively, developed heart failure. In young participants, 32% (n=44) of heart failure cases were classified as heart failure with preserved ejection fraction compared with 43% (n=179) in elderly participants. Risk factors including hypertension, diabetes, current smoking history, and previous myocardial infarction conferred greater relative risk in younger compared with older participants (P for interaction <0.05 for all). For example, hypertension was associated with a threefold increase in risk of future heart failure in young participants (hazard ratio 3.02, 95% confidence interval 2.10 to 4.34; P<0.001) compared with a 1.4-fold risk in elderly participants (1.43, 1.13 to 1.81; P=0.003). The absolute risk for developing heart failure was lower in younger than in older participants with and without risk factors. Importantly, known risk factors explained a greater proportion of overall population attributable risk for heart failure in young participants (75% v 53% in elderly participants), with better model performance (C index 0.79 v 0.64). Similarly, the population attributable risks of obesity (21% v 13%), hypertension (35% v 23%), diabetes (14% v 7%), and current smoking (32% v 1%) were higher in young compared with elderly participants. CONCLUSIONS: Despite a lower incidence and absolute risk of heart failure among younger compared with older people, the stronger association and greater attributable risk of modifiable risk factors among young participants highlight the importance of preventive efforts across the adult life course
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