185 research outputs found

    Improved Probability Method for Estimating Signal in the Presence of Background

    Get PDF
    A suggestion is made for improving the Feldman Cousins method of estimating signal counts in the presence of background. The method concentrates on finding essential information about the signal and ignoring extraneous information about background. An appropriate method is found which uses the condition that the number of background events obtained does not exceed the total number of events obtained. Several alternative approaches are explored.Comment: Modified 12/21 for singlespace to save trees, 9 pages, 1 figure. Modified 8/11/99 to add small modifications made for the Phys. Rev. articl

    On the weak convergence of stochastic processes without discontinuities of the second kind

    Full text link
    Subspaces D α , α > 0, of D [0, 1] are defined and given complete metrics d α which are stronger than the Prokhorov metric. The spaces ( D α d α ) are shown to be separable, and their pre-compact subsets are characterized. A condition which is known to guarantee weak pre-compactness of sets of probability measures over D [0, 1] is shown to also guarantee weak pre-compactness of probability measures over D α for appropriate values of α. Applications are made to the weak convergence of measures induced by stochastic processes, and some examples are included.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47645/1/440_2004_Article_BF00538382.pd

    Effects of an exercise and hypocaloric healthy eating intervention on indices of psychological health status, hypothalamic-pituitary-adrenal axis regulation and immune function after early-stage breast cancer : a randomised controlled trial

    Get PDF
    INTRODUCTION: Many women experience emotional distress, depression and anxiety after a diagnosis of breast cancer. Psychological stress and depression have been associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation that may adversely affect immune system functioning and impact upon survival. This study investigated the effects of a lifestyle intervention on indices of psychological health status, HPA axis regulation and immune function in overweight women recovering from early-stage breast cancer treatment. METHODS: A total of 85 women treated for breast cancer 3 to 18 months previously were randomly allocated to a 6-month exercise and hypocaloric healthy eating program plus usual care or usual care alone (control group). Women in the intervention group received three supervised exercise sessions per week and individualized dietary advice, supplemented by weekly nutrition seminars. Depressive symptoms (Beck Depression Inventory version II: BDI-II), perceived stress (Perceived Stress Scale: PSS), salivary diurnal cortisol rhythms; inflammatory cytokines (IL-6 and Tumor necrosis factor-α), leukocyte phenotype counts, natural killer (NK) cell cytotoxicity and lymphocyte proliferation following mitogenic stimulation were assessed at baseline and 6-month follow up. RESULTS: Compared with the control group, the intervention group exhibited a reduction in depressive symptoms (adjusted mean difference, 95% confidence intervals (95% CI): -3.12, -1.03 to -5.26; P = 0.004) at the 6-month follow-up but no significant decrease in PSS scores (-2.07, -4.96 to 0.82; P = 0.16). The lifestyle intervention also had a significant impact on diurnal salivary cortisol rhythm compared with usual care alone, as evidenced by an increase in morning salivary cortisol at the 6-month follow-up (P <0.04), indicating a change in HPA axis regulation. Women in the control group had higher total leukocyte, neutrophil and lymphocyte counts in comparison to the intervention group at the 6-month follow-up (P ≤0.05), whereas there was no difference in NK cell counts (P = 0.46), NK cell cytotoxicity (P = 0.85) or lymphocyte proliferation responses (P = 0.11) between the two groups. CONCLUSION: Our results show that the lifestyle intervention resulted in a reduction in depressive symptoms and a normalisation of HPA axis regulation. Such changes could have important implications for long-term survival in women recovering from early-breast cancer treatment. TRIAL REGISTRATION: Current Controlled Trials: ISRCTN08045231

    Regularity of Edge Ideals and Their Powers

    Full text link
    We survey recent studies on the Castelnuovo-Mumford regularity of edge ideals of graphs and their powers. Our focus is on bounds and exact values of  reg I(G)\text{ reg } I(G) and the asymptotic linear function  reg I(G)q\text{ reg } I(G)^q, for q≥1,q \geq 1, in terms of combinatorial data of the given graph G.G.Comment: 31 pages, 15 figure

    On sequential fixed-width confidence intervals for the mean and second-order expansions of the associated coverage probabilities

    Full text link
    In order to construct fixed-width (2d) confidence intervals for the mean of an unknown distribution function F , a new purely sequential sampling strategy is proposed first. The approach is quite different from the more traditional methodology of Chow and Robbins (1965, Ann. Math. Statist. , 36 , 457–462). However, for this new procedure, the coverage probability is shown (Theorem 2.1) to be at least (1-α)+ Ad 2 + o (d 2 ) as d →0 where (1-α) is the preassigned level of confidence and A is an appropriate functional of F , under some regularity conditions on F . The rates of convergence of the coverage probability to (1-α) obtained by Csenki (1980, Scand. Actuar. J. , 107–111) and Mukhopadhyay (1981, Comm. Statist. Theory Methods , 10 , 2231–2244) were merely O (d 1/2-q ), with 0< q <1/2, under the Chow-Robbins stopping time τ * . It is to be noted that such considerable sharpening of the rate of convergence of the coverage probability is achieved even though the new stopping variable is O p (τ * ). An accelerated version of the stopping rule is also provided together with the analogous second-order characteristics. In the end, an example is given for the mean estimation problem of an exponential distribution.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47956/1/10463_2004_Article_BF00050850.pd

    Evaluation of ADAMTS-9 Expression in Post-Mortem Brain Tissue

    Get PDF
    Background: Extracellular Matrix (ECM) modifications have been reported in the Central Nervous System (CNS) of multiple sclerosis (MS) within post mortem brain tissue due to both the increased synthesis of ECM proteoglycans, and release activation of matrix metalloproteinase (MMPs). Multiple sclerosis (MS) is chronic inflammatory demyelinating disease written off as inflammation and demyelination disease, mainly located in central nervous system (CNS) white matter (WM). This study aims to clarify the potential pathophysiologic role of adisintegrin And metalloproteinase with thromboSpondin motif-9 (ADAMTS-9) in MS. Materials and methods: Immunohistochemistry was performed to study the expression of ADAMTS-9 in both normal and MS white matter by confocal microscopic using specific antibodies. Fifty frozen blocks of brain tissue were obtained from the UK MS Society Tissue. All tissues blocks were marked by immunohistological material including antibodies to Human leukocyte antigen (HLA-DR) to assess the macrophage activation, Glial fibrillary acidic protein (GFAP) for astrocyte, neurofilaments (NF) for neurons and Von Willbrand factor (VWF) for endothelial. Results: In MS lesions, ADMTS-9 expression was increased in comparison to control samples. The expression of ADAMTS-9 was increased in active lesions as well as was associated with different cells from neuron, endothelial covering blood vessels astrocyte and microglia. Conclusion: The expression of ADAMTS-9 at the protein level was increased in active inflammatory lesions with evidence of myelin breakdown, suggesting that up-regulation of ADAMTS-9 may be a general phenomenon induced by CNS injurie

    On the future of astrostatistics: statistical foundations and statistical practice

    Full text link
    This paper summarizes a presentation for a panel discussion on "The Future of Astrostatistics" held at the Statistical Challenges in Modern Astronomy V conference at Pennsylvania State University in June 2011. I argue that the emerging needs of astrostatistics may both motivate and benefit from fundamental developments in statistics. I highlight some recent work within statistics on fundamental topics relevant to astrostatistical practice, including the Bayesian/frequentist debate (and ideas for a synthesis), multilevel models, and multiple testing. As an important direction for future work in statistics, I emphasize that astronomers need a statistical framework that explicitly supports unfolding chains of discovery, with acquisition, cataloging, and modeling of data not seen as isolated tasks, but rather as parts of an ongoing, integrated sequence of analyses, with information and uncertainty propagating forward and backward through the chain. A prototypical example is surveying of astronomical populations, where source detection, demographic modeling, and the design of survey instruments and strategies all interact.Comment: 8 pp, 2 figures. To appear in "Statistical Challenges in Modern Astronomy V," (Lecture Notes in Statistics, Vol. 209), ed. Eric D. Feigelson and G. Jogesh Babu; publication planned for Sep 2012; see http://www.springer.com/statistics/book/978-1-4614-3519-

    Estimating a mean from delayed observations

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47652/1/440_2004_Article_BF00533314.pd

    Study protocol to investigate the effect of a lifestyle intervention on body weight, psychological health status and risk factors associated with disease recurrence in women recovering from breast cancer treatment

    Get PDF
    Background Breast cancer survivors often encounter physiological and psychological problems related to their diagnosis and treatment that can influence long-term prognosis. The aim of this research is to investigate the effects of a lifestyle intervention on body weight and psychological well-being in women recovering from breast cancer treatment, and to determine the relationship between changes in these variables and biomarkers associated with disease recurrence and survival. Methods/design Following ethical approval, a total of 100 patients will be randomly assigned to a lifestyle intervention (incorporating dietary energy restriction in conjunction with aerobic exercise training) or normal care control group. Patients randomised to the dietary and exercise intervention will be given individualised healthy eating dietary advice and written information and attend moderate intensity aerobic exercise sessions on three to five days per week for a period of 24 weeks. The aim of this strategy is to induce a steady weight loss of up to 0.5 Kg each week. In addition, the overall quality of the diet will be examined with a view to (i) reducing the dietary intake of fat to ~25% of the total calories, (ii) eating at least 5 portions of fruit and vegetables a day, (iii) increasing the intake of fibre and reducing refined carbohydrates, and (iv) taking moderate amounts of alcohol. Outcome measures will include body weight and body composition, psychological health status (stress and depression), cardiorespiratory fitness and quality of life. In addition, biomarkers associated with disease recurrence, including stress hormones, estrogen status, inflammatory markers and indices of innate and adaptive immune function will be monitored. Discussion This research will provide valuable information on the effectiveness of a practical, easily implemented lifestyle intervention for evoking positive effects on body weight and psychological well-being, two important factors that can influence long-term prognosis in breast cancer survivors. However, the added value of the study is that it will also evaluate the effects of the lifestyle intervention on a range of biomarkers associated with disease recurrence and survival. Considered together, the results should improve our understanding of the potential role that lifestyle-modifiable factors could play in saving or prolonging lives
    • …
    corecore