An application of statistics in mixture of exponential distributions

Order statistics in application to exponential distribution

Berardinelli-Seip Syndrome

We have reported two cases of Berardinelli-syndrome in a family which is a rare autosomal recessive disorder of the adipose tissue, originally described by Berardinelli and Seip, has been reported in approximately 120 patients of various ethnic origins. Assuming that only 1 in 4 patients is reported.Patients present with acanthosis nigricans (dark velvety pigmentation of the skin) in the axilla, neck or groin, severe insulin resistance, high levels of serum insulin and serum triglycerides.The other clinical features consist of enlarged hands, feet and prominent mandible (acromegaloid features), increased sweating, umbilical hernia and lytic lesions (bone appear to be eaten-up on X-rays) in long bones of the upper and lower extremities (arms, forearm, hands, thigh, calf, legs and feet) such as humerus, femur, etc. Hepatomegaly from fatty liver is almost universal and may ultimately lead to cirrhosis. Splenomegaly is common. Nearly all patients have a prominent umbilicus or frank umbilical hernia. Females present with enlarged clitoris, increased body hair, absence of or irregular menstrual cycles, and polycystic ovaries (enlarged ovaries). Only a few affected women have had successful pregnancies, whereas affected men have normal fertilit

An application of the multivariate extended Poisson distribution in 2 times 2 contingency tables Final report

Application of multivariate extended Poisson distribution

Characterizing 51 Eri b from 1 to 5 μm: A Partly Cloudy Exoplanet

We present spectrophotometry spanning 1–5 μm of 51 Eridani b, a 2–10 M_(Jup) planet discovered by the Gemini Planet Imager Exoplanet Survey. In this study, we present new K1 (1.90–2.19 μm) and K2 (2.10–2.40 μm) spectra taken with the Gemini Planet Imager as well as an updated L_P (3.76 μm) and new M_S (4.67 μm) photometry from the NIRC2 Narrow camera. The new data were combined with J (1.13–1.35 μm) and H (1.50–1.80 μm) spectra from the discovery epoch with the goal of better characterizing the planet properties. The 51 Eri b photometry is redder than field brown dwarfs as well as known young T-dwarfs with similar spectral type (between T4 and T8), and we propose that 51 Eri b might be in the process of undergoing the transition from L-type to T-type. We used two complementary atmosphere model grids including either deep iron/silicate clouds or sulfide/salt clouds in the photosphere, spanning a range of cloud properties, including fully cloudy, cloud-free, and patchy/intermediate-opacity clouds. The model fits suggest that 51 Eri b has an effective temperature ranging between 605 and 737 K, a solar metallicity, and a surface gravity of log(g) = 3.5–4.0 dex, and the atmosphere requires a patchy cloud atmosphere to model the spectral energy distribution (SED). From the model atmospheres, we infer a luminosity for the planet of −5.83 to −5.93 (log L/L_⊙), leaving 51 Eri b in the unique position of being one of the only directly imaged planets consistent with having formed via a cold-start scenario. Comparisons of the planet SED against warm-start models indicate that the planet luminosity is best reproduced by a planet formed via core accretion with a core mass between 15 and 127 M_⊕

Evolution of Quantum Discord and its Stability in Two-Qubit NMR Systems

We investigate evolution of quantum correlations in ensembles of two-qubit nuclear spin systems via nuclear magnetic resonance techniques. We use discord as a measure of quantum correlations and the Werner state as an explicit example. We first introduce different ways of measuring discord and geometric discord in two-qubit systems and then describe the following experimental studies: (a) We quantitatively measure discord for Werner-like states prepared using an entangling pulse sequence. An initial thermal state with zero discord is gradually and periodically transformed into a mixed state with maximum discord. The experimental and simulated behavior of rise and fall of discord agree fairly well. (b) We examine the efficiency of dynamical decoupling sequences in preserving quantum correlations. In our experimental setup, the dynamical decoupling sequences preserved the traceless parts of the density matrices at high fidelity. But they could not maintain the purity of the quantum states and so were unable to keep the discord from decaying. (c) We observe the evolution of discord for a singlet-triplet mixed state during a radio-frequency spin-lock. A simple relaxation model describes the evolution of discord, and the accompanying evolution of fidelity of the long-lived singlet state, reasonably well.Comment: 9 pages, 7 figures, Phys. Rev. A (in press

Anxiety Associated With Increased Risk for Emergency Department Recidivism in Patients With Low-Risk Chest Pain

Anxiety contributes to the chest pain symptom complex in 30% to 40% of patients with low-risk chest pain seen in the emergency department (ED). The validated Hospital Anxiety Depression Scale-Anxiety subscale (HADS-A) has been used as an anxiety screening tool in this population. The objective was to determine the prevalence of abnormal HADS-A scores in a cohort of low-risk chest pain patients and test the association of HADS-A score with subsequent healthcare utilization and symptom recurrence. In a single-center, prospective, observational cohort study of adult ED subjects with low-risk chest pain, the HADS-A was used to stratify participants into 2 groups: low anxiety (score <8) and high anxiety (score ≥8). At 45-day follow-up, chest pain recurrence was assessed by patient report, whereas ED utilization was assessed through chart review. Of the 167 subjects enrolled, 78 (47%) were stratified to high anxiety. The relative risk for high anxiety being associated with at least one 30-day ED return visit was 2.6 (95% confidence interval 1.4 to 4.7) and this relative risk increased to 9.1 (95% confidence interval 2.18 to 38.6) for 2 or more ED return visits. Occasional chest pain recurrence was reported by more subjects in the high anxiety group, 68% vs 47% (p = 0.029). In conclusion, 47% of low-risk chest pain cohort had abnormal levels of anxiety. These patients were more likely to have occasional recurrence of their chest pain and had an increased risk multiple ED return visits