Estimating the Expected Value of Partial Perfect Information in Health Economic Evaluations using Integrated Nested Laplace Approximation

The Expected Value of Perfect Partial Information (EVPPI) is a decision-theoretic measure of the "cost" of parametric uncertainty in decision making used principally in health economic decision making. Despite this decision-theoretic grounding, the uptake of EVPPI calculations in practice has been slow. This is in part due to the prohibitive computational time required to estimate the EVPPI via Monte Carlo simulations. However, recent developments have demonstrated that the EVPPI can be estimated by non-parametric regression methods, which have significantly decreased the computation time required to approximate the EVPPI. Under certain circumstances, high-dimensional Gaussian Process regression is suggested, but this can still be prohibitively expensive. Applying fast computation methods developed in spatial statistics using Integrated Nested Laplace Approximations (INLA) and projecting from a high-dimensional into a low-dimensional input space allows us to decrease the computation time for fitting these high-dimensional Gaussian Processes, often substantially. We demonstrate that the EVPPI calculated using our method for Gaussian Process regression is in line with the standard Gaussian Process regression method and that despite the apparent methodological complexity of this new method, R functions are available in the package BCEA to implement it simply and efficiently

Sources of Social Capital for Malawi People Living With HIV.

With one of the highest rates of poverty and HIV in the world, Malawi faith-based organizations (FBOs), non-governmental organizations (NGOs), and community-based organizations (CBOs) are expected to provide tangible and emotional support to people living with HIV (PLWH). Using Lin's social capital theoretical approach, we examine the perspective of PLWH regarding the adequacy of support responses. Forty-six rural Malawi HIV+ adults provided interviews that were recorded digitally, translated, and transcribed by Malawi research assistants. Atlas.ti was used to organize the data and to aid in the analytic process. Participants expressed disappointment in the lack of resources that could be accessed through the FBOs although their expectations may have been unrealistic. Outcomes from accessing and mobilizing the FBO network were negative in terms of stigmatization by FBO leaders and members, whereas outcomes related to CBOs and NGOs were generally positive in terms of empowerment through HIV information and attendance at support groups

The common seaman in nineteenth century American fiction

Abstract: 3 p. at end. Autobiography: 1 p. at end. Thesis (Ph. D.)--Boston University. Bibliography: p. 255-268.The role of the common seaman in nineteenth century American fiction is a revelation of the interest in the common man, the growth of democracy, the agitation for humanitarian reform, and the quest for nationalism which characterized the new nation between 1790 and 1865. The fictional seamen not only represent the actual men who shared the crowded quarters of the forecastle, but perhaps they are also a manifestation of the spirit of American democracy and the development of a native mythos. The sea has always been basic to American life and thought. In the opening years of the century, trade with the Orient was highly profitable. American whalers explored the islands of the Pacific and became familiar with the watery wastes from the Arctic to the Antarctic. With the establishment of a strong Navy following the War of 1812, America became one of the great maritime powers of the world. Later in the century when the frontier lured young men of adventure away from the sea and foreign crews filled the forecastles of ships, conditions on board American vessels worsened. Harsh treatment, bad food, long hours, and low pay discouraged men of ability from a maritime career. Yet there were always men who grew restless on land and, like Melville, returned to the sea. It was a piece of extraordinary good fortune that the forecastles of American ships contained three such eloquent spokesmen as James Fenimore Cooper, Richard Henry Dana, Jr., and Herman Melville. The fiction written by these men reflect their own experiences at sea. Cooper sailed in the early days of the century when a young man of ability could begin at the bottom and rise to the quarter-deck. Captains felt a paternal interest in their crews, and men were loyal to their ships. Dana represented the gentlemen of good family who sailed before the mast to restore their health and see life firsthand. A lawyer in later years, he fought to bring about legal reforms for the betterment of seamen. Herman Melville served in every maritime branch-merchantman, whaler, and frigate--in the later years when captains were tyrannical and the crew represented the outcasts of all nations. He saw in their problems not only the need £or maritime reform but the universal suffering or all mankind. Of course, there were romantic novels of the sea. Henry Cheever, Edward Judson, and Captain Ingraham wrote of noble young tars and wicked villains, but to counterbalance these popular tales were the factual narratives of genuine seamen--Nathaniel Ames, Amasa Delano, J. Ross Browne, and Josiah Cobb. Although English writers had already popularized maritime literature, America's unique contribution was the development of seamen such as Long Tom Coffin who, like Jonathan, the Yankee farmer, and Leather-Stocking, the frontiersman, represented a stock figure. Except for the legend of Captain Kidd and the tales of pirates who buried treasure or smuggled along the Atlantic coast, America had little folklore, but her writers created a feeling of mythos through the use of allegory and symbolism. The seaman hero of American fiction was based on fact, but he also was representative of the democratic individual freed from the stultifying restrictions of civilization. Closer to the sea than the land, he was part of the American dream which visualized the typical American as solitary, courageous, ingenious, and kin to the natural elements. The invention of steam-driven vessels and the advent of the Civil War brought the age of sail to an end. New legislation and shorter voyages improved conditions for the common seamen. The "old salt" like the pioneer became part of America's heritage

Galsworthy's concept of Forsytism

Thesis (M.A.)--Boston University, 1947. This item was digitized by the Internet Archive

Coupled-cluster calculations of properties of Boron atom as a monovalent system

We present relativistic coupled-cluster (CC) calculations of energies, magnetic-dipole hyperfine constants, and electric-dipole transition amplitudes for low-lying states of atomic boron. The trivalent boron atom is computationally treated as a monovalent system. We explore performance of the CC method at various approximations. Our most complete treatment involves singles, doubles and the leading valence triples. The calculations are done using several approximations in the coupled-cluster (CC) method. The results are within 0.2-0.4% of the energy benchmarks. The hyperfine constants are reproduced with 1-2% accuracy

A wave function based ab initio non-equilibrium Green's function approach to charge transport

We present a novel ab initio non-equilibrium approach to calculate the current across a molecular junction. The method rests on a wave function based description of the central region of the junction combined with a tight binding approximation for the electrodes in the frame of the Keldysh Green's function formalism. In addition we present an extension so as to include effects of the two-particle propagator. Our procedure is demonstrated for a dithiolbenzene molecule between silver electrodes. The full current-voltage characteristic is calculated. Specific conclusions for the contribution of correlation and two-particle effects are derived. The latter are found to contribute about 5% to the current. The order of magnitude of the current coincides with experiments.Comment: 21 pages, 3 figure

Untangling the Myth of the Model Minority

The model minority stereotype depicts Asian Americans as a group that has succeeded in America and overcome discrimination through its hard work, intelligence, and emphasis on education and achievement - a modern-day confirmation of the American Dream. A large body of work by Asian critical scholars condemns this image and charges that it conceals more sinister beliefs about Asian Americans and other racial minorities in America. Is this critique correct? Does the model minority stereotype really mask hostility toward Asian Americans or breed contempt for other minorities? This article presents the results of an empirical study into the model minority stereotype. Using 1990, 1994, and 2000 General Social Survey data (including some of the very data used by critical scholars to establish the existence of this stereotype), we confirm claims that some non-Hispanic white Americans think that Asian Americans as a group are more intelligent, harder working, and richer than other minorities and that some think Asian Americans are more intelligent and harder working than whites. But we also discovered that these ideas are not usually linked with negative views of Asian Americans (or of other minorities, for that matter). Indeed, we found weak support for the contrary position - that those who rate Asian Americans higher than other minorities, or particularly higher than whites, are more likely to hold other positive views about Asian Americans, immigration, African Americans, and government programs supporting these groups. Our study nonetheless confirms the scholarly suspicions in one crucial respect: non-Hispanic whites who have positive views of Asian Americans are less likely to think that Asian Americans are discriminated against in both jobs and housing, thus tending to support the claims of some Asian critical scholars that positive stereotypes about Asian Americans tend to be associated with a failure to recognize continuing discrimination. In these data, however, this complacency by whites about prejudice against Asians does not translate into hostility toward government programs to alleviate the problems of Asian or African Americans

Resolving all-order method convergence problems for atomic physics applications

The development of the relativistic all-order method where all single, double, and partial triple excitations of the Dirac-Hartree-Fock wave function are included to all orders of perturbation theory led to many important results for study of fundamental symmetries, development of atomic clocks, ultracold atom physics, and others, as well as provided recommended values of many atomic properties critically evaluated for their accuracy for large number of monovalent systems. This approach requires iterative solutions of the linearized coupled-cluster equations leading to convergence issues in some cases where correlation corrections are particularly large or lead to an oscillating pattern. Moreover, these issues also lead to similar problems in the CI+all-order method for many-particle systems. In this work, we have resolved most of the known convergence problems by applying two different convergence stabilizer methods, reduced linear equation (RLE) and direct inversion of iterative subspace (DIIS). Examples are presented for B, Al, Zn$^+$, and Yb$^+$. Solving these convergence problems greatly expands the number of atomic species that can be treated with the all-order methods and is anticipated to facilitate many interesting future applications

Economic evaluation of ASCOT-BPLA: Antihypertensive treatment with an amlodipine-based regimen is cost-effective compared to an atenolol-based regimen

Copyright © 2010 BMJ Publishing Group Ltd & British Cardiovascular Society. Internal or personal use of this material is permitted. However, permission to reprint/republish this material must be obtained from the Publisher.Objective: To compare the cost effectiveness of an amlodipine-based strategy and an atenolol-based strategy in the treatment of hypertension in the UK and Sweden. Design: A prospective, randomised trial complemented with a Markov model to assess long-term costs and health effects. Setting: Primary care. Patients: Patients with moderate hypertension and three or more additional risk factors. Interventions: Amlodipine 5–10 mg with perindopril 4–8 mg added as needed or atenolol 50–100 mg with bendroflumethiazide 1.25–2.5 mg and potassium added as needed Main outcome measures: Cost per cardiovascular event and procedure avoided, and cost per quality-adjusted life-year gained. Results: In the UK, the cost to avoid one cardiovascular event or procedure would be €18 965, and the cost to gain one quality-adjusted life-year would be €21 875. The corresponding figures for Sweden were €13 210 and €16 856. Conclusions: Compared with the thresholds applied by NICE and in the Swedish National Board of Health and Welfare’s Guidelines for Cardiac Care, an amlodipine-based regimen is cost effective for the treatment of hypertension compared with an atenolol-based regimen in the population studied.The study was supported by the principal funding source, Pfizer, New York, USA