173 research outputs found

    Geometric ergodicity in a weighted sobolev space

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    For a discrete-time Markov chain {X(t)}\{X(t)\} evolving on \Re^\ell with transition kernel PP, natural, general conditions are developed under which the following are established: 1. The transition kernel PP has a purely discrete spectrum, when viewed as a linear operator on a weighted Sobolev space Lv,1L_\infty^{v,1} of functions with norm, fv,1=supx1v(x)max{f(x),1f(x),,f(x)}, \|f\|_{v,1} = \sup_{x \in \Re^\ell} \frac{1}{v(x)} \max \{|f(x)|, |\partial_1 f(x)|,\ldots,|\partial_\ell f(x)|\}, where v ⁣:[1,)v\colon \Re^\ell \to [1,\infty) is a Lyapunov function and i:=/xi\partial_i:=\partial/\partial x_i. 2. The Markov chain is geometrically ergodic in Lv,1L_\infty^{v,1}: There is a unique invariant probability measure π\pi and constants B<B<\infty and δ>0\delta>0 such that, for each fLv,1f\in L_\infty^{v,1}, any initial condition X(0)=xX(0)=x, and all t0t\geq 0: Ex[f(X(t))]π(f)Beδtv(x),Ex[f(X(t))]2Beδtv(x),\Big| \text{E}_x[f(X(t))] - \pi(f)\Big| \le Be^{-\delta t}v(x),\quad \|\nabla \text{E}_x[f(X(t))] \|_2 \le Be^{-\delta t} v(x), where π(f)=fdπ\pi(f)=\int fd\pi. 3. For any function fLv,1f\in L_\infty^{v,1} there is a function hLv,1h\in L_\infty^{v,1} solving Poisson's equation: hPh=fπ(f). h-Ph = f-\pi(f). Part of the analysis is based on an operator-theoretic treatment of the sensitivity process that appears in the theory of Lyapunov exponents

    Strategies for Stakeholder Engagement and Uptake of New Intervention: Experience From State-Wide Implementation of mHealth Technology for NCD Care in Tripura, India.

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    BACKGROUND: Appropriate strategies and key stakeholder engagement are the keys to successful implementation of new health care interventions. OBJECTIVES: The study sought to articulate the key strategies used for scaling up a research-based intervention, mPower Heart electronic Clinical Decision Support System (e-CDSS), for state-wide implementation at health facilities in Tripura. METHODS: Multiple strategies were used for statewide implementation of mPower Heart e-CDSS at noncommunicable diseases clinics across the government health facilities in Tripura: formation of a technical coordination-cum-support unit, change management, enabling environment, adapting the intervention with user focus, and strengthening the Health Information System. RESULTS: The effective delivery of a new health system intervention requires engagement at multiple levels including political leadership, health administrators, and health professionals, which can be achieved by forming a technical coordination-cum-support unit. It is important to specify the role and responsibilities of existing manpower and provide a structured training program. Enabling environment at health facilities (providing essential equipment, space and time, etc.) is also crucial. Successful implementation also requires that patients, health care providers, the health system, and leadership recognize the immediate and long-term benefits of the new intervention and have a buy-in in the intervention. With constant encouragement and nudge from administrative authorities and by using multiple strategies, 40 government health facilities adopted the mPower Heart e-CDSS. From its launch in May 2017 until November 20, 2018, a total of 100,810 eligible individuals were screened and enrolled, with 35,884 treated for hypertension, 9,698 for diabetes, and 5,527 for both hypertension and diabetes. CONCLUSIONS: Multiple strategies, based on implementation principles, are required for successful scaling up of research-based interventions

    A study of serum lipid profile in normal pregnancy and pregnancy induced hypertensive disorders: a case-control study

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    Background: Pregnancy induced hypertensive disorders are one of the commonest complication of pregnancy which accounts for 12% of the maternal and perinatal mortality and morbidity. Dyslipidemias are associated with endothelial dysfunction that may result in proteinuria and hypertension which is a clinical hallmark of PIH. It affects both maternal health as well as fetal growth. Hence, this study was done to assess the role of altered lipid profile in the development of PIH.Methods: A Case Control study was conducted at the Department of Biochemistry, Kurnool Medical College and Govt General Hospital, Kurnool in collaboration with its Obstetrics Dept during the period of November 2015-2017. A total of 300 pregnant women, primigravida /multigravida with singleton pregnancy, in the age group of 18‐ 35 years with >20 weeks of gestation were included in the study. Subjects were divided into gestational hypertensives, n=39 (BP ≥140/80) and preeclamptic women, n=111 (≥140/80 and proteinuria) as cases. Age matched normotensive pregnant women, n=150 (BP 120/80) were recruited as Controls. Subjects with history of multiple pregnancies, pregnancy with congenital anomalies, chronic hypertension, diabetes mellitus, cardiac/thyroid/hepatic/renal disease, dyslipidemia were excluded. Total cholesterol, TG, HDL, LDL, VLDL were performed.Results: A comparison of these values between hypertensive and normotensive women showed a significant rise in TC, TG, LDL and VLDL. HDL-C showed a significant decrease in hypertensive women compared to normal pregnant women. LDL: HDL and TG:HDL ratios were higher in PIH group.Conclusions: The results of this study suggests an abnormal lipid metabolism, predominantly high TG concentrations and low HDL-C, which may add to the promotion of vascular dysfunction and oxidative stress seen in PIH. This association is significant in understanding the development of hypertension during pregnancy and is useful in early diagnosis and prevention of PIH

    Hard and soft multilayered SiCN nanocoatings with high hardness and toughness

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    Alternate hard and soft layers increase deformation accommodation as thin hard layers slide relative to each other due to shear deformation of low modulus layers. However, the processing of such multilayers is challenging. In the present paper the alternating soft and hard multilayered SiCN coating deposited by magnetron sputtering has been studied and presented. A hardness and modulus of 37 GPa and 317 GPa with elastic recovery of 62% are achieved by alternate hard and soft layer of Si-C-N by magnetron sputtering. The trilayer films sustained even 2000 gf under indentation without failure though substrate plastically deformed. The fracture toughness value K-IC was measured to be 9.5-10 MPa m(1/2), significantly higher than many reported hard coatings

    Development of a Smartphone-Enabled Hypertension and Diabetes Mellitus Management Package to Facilitate Evidence-Based Care Delivery in Primary Healthcare Facilities in India: The mPower Heart Project.

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    BACKGROUND: The high burden of undetected and undertreated hypertension and diabetes mellitus is a major health challenge worldwide. The mPower Heart Project aimed to develop and test a feasible and scalable intervention for hypertension and diabetes mellitus by task-sharing with the use of a mobile phone-based clinical decision support system at Community Health Centers in Himachal Pradesh, India. METHODS AND RESULTS: The development of the intervention and mobile phone-based clinical decision support system was carried out using mixed methods in five Community Health Centers. The intervention was subsequently evaluated using pre-post evaluation design. During intervention, a nurse care coordinator screened, examined, and entered patient parameters into mobile phone-based clinical decision support system to generate a prescription, which was vetted by a physician. The change in systolic blood pressure, diastolic blood pressure, and fasting plasma glucose (FPG) over 18 months of intervention was quantified using generalized estimating equations models. During intervention, 6797 participants were enrolled. Six thousand sixteen participants had hypertension (mean systolic blood pressure: 146.1 mm Hg, 95% CI: 145.7, 146.5; diastolic blood pressure: 89.52 mm Hg, 95% CI: 89.33, 89.72), of which 3152 (52%) subjects were newly detected. Similarly, 1516 participants had diabetes mellitus (mean FPG: 177.9 mg/dL, 95% CI: 175.8, 180.0), of which 450 (30%) subjects were newly detected. The changes in systolic blood pressure, diastolic blood pressure, and FPG observed at 18 months of follow-up were -14.6 mm Hg (95% CI: -15.3, -13.8), -7.6 mm Hg (CI: -8.0, -7.2), and -50.0 mg/dL (95% CI: -54.6, -45.5), respectively, and were statistically significant even after adjusting for age, sex, and Community Health Center. CONCLUSIONS: A nurse-facilitated, mobile phone-based clinical decision support system-enabled intervention in primary care was associated with improvements in blood pressure and blood glucose control and has the potential to scale-up in resource poor settings. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifiers: NCT01794052. Clinical Trial Registry-India: CTRI/2013/02/003412

    A microscopic complex potential description of elastic, inelastic cross section in the Coulomb nuclear interference region in the 28Si on 28Si system

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    Elastic and inelastic angular distribution and excitation functions were measured for the 28Si + 28Si system in the vicinity of the Coulomb barrier. While the elastic data could be described very well by using fully microscopic complex potential, the inelastic cross sections were found to be more sensitive to small variations in the potential. In particular the Coulomb nuclear interference dip observed in the inelastic excitation functions could not be fitted satisfactorily with calculation. Inclusion of an energy dependent term of Gaussian shape to the associated matrix element with the reorientation coupling in the phenomenological calculations leads to a better fit the inelastic excitation functions. © 1998 Elsevier Science B.V

    Patterns in the spectral composition of sunlight and biologically meaningful spectral photon ratios as affected by atmospheric factors

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    Plants rely on spectral cues present in their surroundings, generated by the constantly changing light environment, to guide their growth and reproduction. Photoreceptors mediate the capture of information by plants from the light environment over a wide range of wavelengths, but despite extensive evidence that plants respond to various light cues, only fragmentary data have been published showing patterns of diurnal, seasonal and geographical variation in the spectral composition of daylight. To illustrate patterns in spectral photon ratios, we measured time series of irradiance spectra at two distinct geographical and climatological locations, Helsinki, Finland and Gual Pahari, India. We investigated the drivers behind variation of the spectral photon ratios measured at these two locations, based on the analysis of over 400 000 recorded spectra. Differences in spectral irradiance were explained by different atmospheric factors identified through multiple regression model analysis and comparison to spectral irradiance at ground level simulated with a radiative transfer model. Local seasonal and diurnal changes in spectral photon ratios were related to solar elevation angle, atmospheric water-vapour content and total ozone column thickness and deviated from their long-term averages to an extent likely to affect plant photobiology. We suggest that future studies should investigate possible effects of varying photon ratios on terrestrial plants. Solar elevation angle especially affects the patterns of B:G and B:R ratios. Water vapour has a large effect on the R:FR photon ratio and modelled climate scenarios predict that increasing global temperatures will result in increased atmospheric water vapour. The development of proxy models, utilising available data from weather and climate models, for relevant photon ratios as a function of solar elevation angle and atmospheric factors would facilitate the interpretation of results from past, present and future field studies of plants and vegetation.Peer reviewe

    Percutaneous Coronary Intervention in Patients With a History of Gastrointestinal Bleeding (From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium)

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    Potent antithrombotic agents are routinely prescribed after percutaneous coronary intervention (PCI) to reduce ischemic complications. However, in patients who are at an increased bleeding risk, this may pose significant risks. We sought to evaluate the association between a history of gastrointestinal bleeding (GIB) and outcomes after PCI. We linked clinical registry data from PCIs performed at 48 Michigan hospitals between 1/2013 and 3/2018 to Medicare claims. We used 1:5 propensity score matching to adjust for patient characteristics. In-hospital outcomes included bleeding, transfusion, stroke or death. Post-discharge outcomes included 90-day all-cause readmission and long-term mortality. Of 30,206 patients, 1.1% had a history of GIB. Patients with a history of GIB were more likely to be older, female, and have more cardiovascular comorbidities. After matching, those with a history of GIB (n = 312) had increased post-procedural transfusions (15.7% vs 8.4%; p \u3c 0.001), bleeding (11.9% vs 5.2%; p \u3c 0.001), and major bleeding (2.8% vs 0.6%; p = 0.004). Ninety-day readmission rates were similar among those with and without a history of GIB (34.3% vs 31.3%; p = 0.318). There was no significant difference in post-discharge survival (1 year: 78% vs 80%; p = 0.217; 5 years: 54% vs 51%; p = 0.189). In conclusion, after adjusting for baseline characteristics, patients with a history of GIB had increased risk of post-PCI in-hospital bleeding complications. However, a history of GIB was not significantly associated with 90-day readmission or long-term survival

    Tracking Cardiac Rehabilitation Utilization in Medicare Beneficiaries: 2017 UPDATE

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    PURPOSE: This study updates cardiac rehabilitation (CR) utilization data in a cohort of Medicare beneficiaries hospitalized for CR-eligible events in 2017, including stratification by select patient demographics and state of residence. METHODS: We identified Medicare fee-for-service beneficiaries who experienced a CR-eligible event and assessed their CR participation (≥1 CR sessions in 365 d), engagement, and completion (≥36 sessions) rates through September 7, 2019. Measures were assessed overall, by beneficiary characteristics and state of residence, and by primary (myocardial infarction; coronary artery bypass surgery; heart valve repair/replacement; percutaneous coronary intervention; or heart/heart-lung transplant) and secondary (angina; heart failure) qualifying event type. RESULTS: In 2017, 412 080 Medicare beneficiaries had a primary CR-eligible event and 28.6% completed ≥1 session of CR within 365 d after discharge from a qualifying event. Among beneficiaries who completed ≥1 CR session, the mean total number of sessions was 25 ± 12 and 27.6% completed ≥36 sessions. Nebraska had the highest enrollment rate (56.1%), with four other states also achieving an enrollment rate \u3e50% and 23 states falling below the overall rate for the United States. CONCLUSIONS: The absolute enrollment, engagement, and program completion rates remain low among Medicare beneficiaries, indicating that many patients did not benefit or fully benefit from a class I guideline-recommended therapy. Additional research and continued widespread adoption of successful enrollment and engagement initiatives are needed, especially among identified populations
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