54 research outputs found

    Finite one dimensional impenetrable Bose systems: Occupation numbers

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    Bosons in the form of ultra cold alkali atoms can be confined to a one dimensional (1d) domain by the use of harmonic traps. This motivates the study of the ground state occupations λi\lambda_i of effective single particle states ϕi\phi_i, in the theoretical 1d impenetrable Bose gas. Both the system on a circle and the harmonically trapped system are considered. The λi\lambda_i and ϕi\phi_i are the eigenvalues and eigenfunctions respectively of the one body density matrix. We present a detailed numerical and analytic study of this problem. Our main results are the explicit scaled forms of the density matrices, from which it is deduced that for fixed ii the occupations λi\lambda_i are asymptotically proportional to N\sqrt{N} in both the circular and harmonically trapped cases.Comment: 22 pages, 8 figures (.eps), uses REVTeX

    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

    Accuracy of WAAS-enabled GPS for the determination of position and speed over ground

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    La précision du GPS WAAS/EGNOS est testée pour des mesures de vitesse en cyclism

    Increased risk of biochemical and clinical failure for prostate patients with a large rectum at radiotherapy planning: results from the Dutch trial of 68 GY versus 78 Gy

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    Purpose : To investigate whether a large rectum filling visible on the planning CT scan was associated with a decrease in freedom from any failure (FFF) and freedom from clinical failure (FFCF) for prostate cancer patients. Methods and materials : Patients from the Dutch trial (78 Gy vs. 68 Gy) with available acute toxicity data were analyzed (n = 549). A 10-mm margin was applied for the first 68 Gy and 0-5 mm for the 10-Gy boost. The dose in the seminal vesicles (SVs) was prescribed within four treatment groups according to the estimated risk of SV involvement. Two potential risk factors (RFs) for a geometric miss were defined: (1) an anorectal volume > or = 90 cm(3) and > or = 25% of treatment-time diarrhea (RF1); and (2) the mean cross-sectional area of the anorectum (RF2). We tested whether these were significant predictors for FFF and FFCF within each treatment group. Results : Significant results were observed only for patients with a risk of SV involvement > 25% (dose of 68-78 Gy to the SVs, n = 349). We found a decrease in FFF (p = 0.001) and FFCF (p = 0.01) for the 87 patients with RF1 (for RF2, p = 0.02 and p = 0.01, respectively). The estimated decrease in the FFCF rate at 5 years was 15%. Conclusion : Tumor control was significantly decreased in patients with a risk of SV involvement > 25% and at risk of geometric miss. Current image guidance techniques offer several solutions to geometrically optimize the treatment. Additional research is needed to evaluate whether geometric misses can be prevented using these techniques

    Aplicação de análise de valor em simulação de alternativas de projetos industriais

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    O presente trabalho visa apresentar o uso da Análise de Valor em simulação de processos industriais, objetivando uma resposta mais rápida e com maior segurança, na fase de tomada de decisã

    Prognostic impact of urokinase-type plasminogen activator receptor (uPAR) in cytosols and pellet extracts derived from primary breast tumours.

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    Item does not contain fulltextUsing a previously developed enzyme-linked immunosorbent assay (ELISA), the levels of the receptor for urokinase-type plasminogen activator (uPAR) were determined in cytosols and corresponding membrane pellets derived from 878 primary breast tumours. The levels of uPAR in the pellet extracts were more than 3-fold higher than those measured in the cytosols (P< 0.001). Moreover, the uPAR levels in the two types of extracts were weakly, though significantly, correlated with each other (rS= 0.20, P< 0.001). In Cox univariate analysis, high cytosolic levels of uPAR were significantly associated with reduced overall survival (OS) and relapse-free survival (RFS). The levels of uPAR in pellet extracts appeared not to be related with patient survival. In multivariate analysis, elevated levels of uPAR measured in cytosols and pellet extracts were found to be independent predictors of poor OS, not RFS. The prediction of poor prognosis on the basis of high uPAR levels emphasizes its important role in plasmin-mediated degradation of extracellular matrix proteins during cancer invasion and metastasis
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