The Generalized Spectral Kurtosis Estimator

Due to its conceptual simplicity and its proven effectiveness in real-time detection and removal of radio frequency interference (RFI) from radio astronomy data, the Spectral Kurtosis (SK) estimator is likely to become a standard tool of a new generation of radio telescopes. However, the SK estimator in its original form must be developed from instantaneous power spectral density (PSD) estimates, and hence cannot be employed as an RFI excision tool downstream of the data pipeline in existing instruments where any time averaging is performed. In this letter, we develop a generalized estimator with wider applicability for both instantaneous and averaged spectral data, which extends its practical use to a much larger pool of radio instruments.Comment: 5 pages, 2 figures, MNRAS Letters accepte

Weak Phase gamma Using Isospin Analysis and Time Dependent Asymmetry in B_d -> K_s pi^+ pi^-

We present a method for measuring the weak phase gamma using isospin analysis of three body B decays into K pi pi channels. Differential decay widths and time dependent asymmetry in B_d -> K_s pi^+pi^- mode needs to be measured into even isospin pi pi states. The method can be used to extract gamma, as well as, the size of the electroweak penguin contributions. The technique is free from assumptions like SU(3) or neglect of any contributions to the decay amplitudes. By studying different regions of the Dalitz plot, it is possible to reduce the ambiguity in the value of gamma.Comment: 11 pages, 1 figur

Neutrino oscillation probabilities: Sensitivity to parameters

We study in detail the sensitivity of neutrino oscillation probabilities to the fundamental neutrino parameters and their possible determination through experiments. The first part of the paper is devoted to the broad theme of isolating regions in the neutrino (and anti-neutrino) energy and propagation length that are sensitive to the oscillation parameters. Such a study is relevant to neutrinos both from the Earth's atmosphere or from a neutrino factory. For completeness we discuss the sensitivity, however small, to the parameters involved in a three-generation framework, and to the Earth matter density profile. We then study processes relevant to atmospheric neutrinos which are sensitive to and allow precision measurements of the mixing angle theta_23 and mass-squared difference delta_32 apart from the mixing angle theta_13. Crucial to this analysis is charge identification; detectors having this capability can isolate these matter effects. In particular, we address the issue of using matter effects to determine whether the mixing angle theta_23 is maximal, and, if not, to explore how well its octant can be determined. When realistic detector resolutions are included, we find that deviations of about 15% (20%) from a maximal value of sin^2 theta_23=1/2 can be measured at 95% (99%) CL provided theta_13 is non-zero, sin^2 theta_13 >= 0.015, and the neutrino mass ordering is normal, with fairly large exposures of 1000 kton-years.Comment: 37 pages Latex file, 30 eps figure files; minor typos fixe

Dietary dairy product intake and incident type 2 diabetes: a prospective study using dietary data from a 7-day food diary

The consumption of specific dairy types may be beneficial for the prevention of diabetes. Abstract: The aim of this study was to investigate the association between total and types of dairy product intake and risk of developing incident type 2 diabetes, using a food diary. Methods: A nested case-cohort within the EPIC-Norfolk Study was examined, including a random subcohort (n=4,000) and cases of incident diabetes (n=892, including 143 cases in the subcohort) followed-up for 11 years. Diet was assessed using a prospective 7-day food diary. Total dairy intake (g/day) was estimated and categorised into high-fat (≥3.9%) and low-fat (<3.9% fat) dairy, and by subtype into yoghurt, cheese and milk. Combined fermented dairy product intake (yoghurt, cheese, sour cream) was estimated and categorised into high- and low-fat. Prentice-weighted Cox regression HRs were calculated. Results: Total dairy, high-fat dairy, milk, cheese and high-fat fermented dairy product intakes were not associated with the development of incident diabetes. Low-fat dairy intake was inversely associated with diabetes in age- and sex-adjusted analyses (tertile [T] 3 vs T1, HR 0.81 [95% CI 0.66, 0.98]), but further adjustment for anthropometric, dietary and diabetes risk factors attenuated this association. In addition, an inverse association was found between diabetes and low-fat fermented dairy product intake (T3 vs T1, HR 0.76 [95% CI 0.60, 0.99]; ptrend=0.049) and specifically with yoghurt intake (HR 0.72 [95% CI 0.55, 0.95]; ptrend=0.017) in multivariable adjusted analyses. Conclusions/interpretation: Greater low-fat fermented dairy product intake, largely driven by yoghurt intake, was associated with a decreased risk of type 2 diabetes development in prospective analyses. These findings suggest that the consumption of specific dairy types may be beneficial for the prevention of diabetes, highlighting the importance of food group subtypes for public health messages

Dietary fat and cardiometabolic health: evidence, controversies, and consensus for guidance.

Although difficulties in nutrition research and formulating guidelines fuel ongoing debate, the complexities of dietary fats and overall diet are becoming better understood, argue Nita G Forouhi and colleague

Nutritional adequacy and dietary disparities in an adult Caribbean population of African descent with a high burden of diabetes and cardiovascular disease.

The Caribbean island of Barbados has a high burden of diabetes and cardiovascular disease. Dietary habits were last described in 2005. A representative population-based sample (n = 363, aged 25-64 years) provided two nonconsecutive 24-hr dietary recalls in this cross-sectional study. Mean daily nutrient intakes were compared with the Dietary Guidelines for Americans. Subgroup differences by age, sex, and educational level were examined using logistic regression. High sugar intakes exist for both sexes with 24% (95% CIs 18.9, 30.0) consuming less than the recommended <10% of energy from added sugars (men 22%; 15.0, 31.6; women 26%; 18.9, 33.7). Sugar-sweetened beverages provide 43% (42.2%, 44.4%) of total sugar intake. Inadequate dietary fiber intakes (men 21 g, 18.2, 22.8; women 18 g, 16.7, 18.9) exist across all age groups. Inadequate micronutrient intake was found in women for calcium, folate, thiamine, zinc, and iron. Older persons (aged 45-64 years) were more likely to report adequacy of dietary fiber (OR = 2.7, 1.5, 4.8) and iron (OR = 3.0, 1.7, 5.3) than younger persons (aged 25-44). Older persons (aged 45-64 years) were less likely to have an adequate supply of riboflavin (OR = 0.4, 0.2, 0.6) than younger persons. Men were more likely to have adequate intakes of iron (OR = 13.0, 6.1, 28.2), folate (OR = 2.4, 1.3, 4.6), and thiamine (OR = 3.0, 1.5, 5.0) than women. Education was not associated with nutrient intake. The Barbadian diet is characterized by high sugar intakes and inadequate dietary fiber; a nutrient profile associated with an increased risk of obesity, type 2 diabetes, and related noncommunicable diseases

Fast and accurate method for computing non-smooth solutions to constrained control problems

Introducing flexibility in the time-discretisation mesh can improve convergence and computational time when solving differential equations numerically, particularly when the solutions are discontinuous, as commonly found in control problems with constraints. State-of-the-art methods use fixed mesh schemes, which cannot achieve superlinear convergence in the presence of non-smooth solutions. In this paper, we propose using a flexible mesh in an integrated residual method. The locations of the mesh nodes are introduced as decision variables, and constraints are added to set upper and lower bounds on the size of the mesh intervals. We compare our approach to a uniform fixed mesh on a real-world satellite reorientation example. This example demonstrates that the flexible mesh enables the solver to automatically locate the discontinuities in the solution, has superlinear convergence and faster solve time