1,851 research outputs found
Economics versus Politics: Pitfalls of Policy Advice
The standard approach to policy-making and advice in economics implicitly or explicitly ignores politics and political economy, and maintains that if possible, any market failure should be rapidly removed. This essay explains why this conclusion may be incorrect; because it ignores politics, this approach is oblivious to the impact of the removal of market failures on future political equilibria and economic efficiency, which can be deleterious. We first outline a simple framework for the study of the impact of current economic policies on future political equilibria and indirectly on future economic outcomes. We then illustrate the mechanisms through which such impacts might operate using a series of examples. The main message is that sound economic policy should be based on a careful analysis of political economy and should factor in its influence on future political equilibria
Deep generative modeling for single-cell transcriptomics.
Single-cell transcriptome measurements can reveal unexplored biological diversity, but they suffer from technical noise and bias that must be modeled to account for the resulting uncertainty in downstream analyses. Here we introduce single-cell variational inference (scVI), a ready-to-use scalable framework for the probabilistic representation and analysis of gene expression in single cells ( https://github.com/YosefLab/scVI ). scVI uses stochastic optimization and deep neural networks to aggregate information across similar cells and genes and to approximate the distributions that underlie observed expression values, while accounting for batch effects and limited sensitivity. We used scVI for a range of fundamental analysis tasks including batch correction, visualization, clustering, and differential expression, and achieved high accuracy for each task
Radiographers supporting radiologists in the interpretation of screening mammography: a viable strategy to meet the shortage in the number of radiologists.
BackgroundAn alternative approach to the traditional model of radiologists interpreting screening mammography is necessary due to the shortage of radiologists to interpret screening mammograms in many countries.MethodsWe evaluated the performance of 15 Mexican radiographers, also known as radiologic technologists, in the interpretation of screening mammography after a 6 months training period in a screening setting. Fifteen radiographers received 6 months standardized training with radiologists in the interpretation of screening mammography using the Breast Imaging Reporting and Data System (BI-RADS) system. A challenging test set of 110 cases developed by the Breast Cancer Surveillance Consortium was used to evaluate their performance. We estimated sensitivity, specificity, false positive rates, likelihood ratio of a positive test (LR+) and the area under the subject-specific Receiver Operating Characteristic (ROC) curve (AUC) for diagnostic accuracy. A mathematical model simulating the consequences in costs and performance of two hypothetical scenarios compared to the status quo in which a radiologist reads all screening mammograms was also performed.ResultsRadiographer's sensitivity was comparable to the sensitivity scores achieved by U.S. radiologists who took the test but their false-positive rate was higher. Median sensitivity was 73.3 % (Interquartile range, IQR: 46.7-86.7 %) and the median false positive rate was 49.5 % (IQR: 34.7-57.9 %). The median LR+ was 1.4 (IQR: 1.3-1.7 %) and the median AUC was 0.6 (IQR: 0.6-0.7). A scenario in which a radiographer reads all mammograms first, and a radiologist reads only those that were difficult for the radiographer, was more cost-effective than a scenario in which either the radiographer or radiologist reads all mammograms.ConclusionsGiven the comparable sensitivity achieved by Mexican radiographers and U.S. radiologists on a test set, screening mammography interpretation by radiographers appears to be a possible adjunct to radiologists in countries with shortages of radiologists. Further studies are required to assess the effectiveness of different training programs in order to obtain acceptable screening accuracy, as well as the best approaches for the use of non-physician readers to interpret screening mammography
Radiative Transfer for Exoplanet Atmospheres
Remote sensing of the atmospheres of distant worlds motivates a firm
understanding of radiative transfer. In this review, we provide a pedagogical
cookbook that describes the principal ingredients needed to perform a radiative
transfer calculation and predict the spectrum of an exoplanet atmosphere,
including solving the radiative transfer equation, calculating opacities (and
chemistry), iterating for radiative equilibrium (or not), and adapting the
output of the calculations to the astronomical observations. A review of the
state of the art is performed, focusing on selected milestone papers.
Outstanding issues, including the need to understand aerosols or clouds and
elucidating the assumptions and caveats behind inversion methods, are
discussed. A checklist is provided to assist referees/reviewers in their
scrutiny of works involving radiative transfer. A table summarizing the
methodology employed by past studies is provided.Comment: 7 pages, no figures, 1 table. Filled in missing information in
references, main text unchange
The Evolution of Compact Binary Star Systems
We review the formation and evolution of compact binary stars consisting of
white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and
BHs are thought to be the primary astrophysical sources of gravitational waves
(GWs) within the frequency band of ground-based detectors, while compact
binaries of WDs are important sources of GWs at lower frequencies to be covered
by space interferometers (LISA). Major uncertainties in the current
understanding of properties of NSs and BHs most relevant to the GW studies are
discussed, including the treatment of the natal kicks which compact stellar
remnants acquire during the core collapse of massive stars and the common
envelope phase of binary evolution. We discuss the coalescence rates of binary
NSs and BHs and prospects for their detections, the formation and evolution of
binary WDs and their observational manifestations. Special attention is given
to AM CVn-stars -- compact binaries in which the Roche lobe is filled by
another WD or a low-mass partially degenerate helium-star, as these stars are
thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure
Recommended from our members
Bias-free photoelectrochemical water splitting with photosystem II on a dye-sensitized photoanode wired to hydrogenase
Natural photosynthesis stores sunlight in chemical energy carriers, but it has not
evolved for the efficient synthesis of fuels, such as H2. Semi-artificial photosynthesis
combines the strengths of natural photosynthesis with synthetic chemistry and
materials science to develop model systems that overcome Nature’s limitations, such
as low-yielding metabolic pathways and non-complementary light absorption by
Photosystem (PS) I and II. Here, we report a bias-free semi-artificial tandem platform
that wires PSII to hydrogenase for overall water splitting. This photoelectrochemical
cell integrated the red and blue light-absorber PSII with a green light-absorbing
diketopyrrolopyrrole dye-sensitised TiO2 photoanode enabling complementary
panchromatic solar light absorption. Effective electronic communication at the
enzyme-material interface was engineered using an Os complex-modified redox
polymer on a hierarchically-structured TiO2. This system provides a design protocol
for bias-free semi-artificial Z-schemes in vitro and provides an extended toolbox of
biotic and abiotic components to re-engineer photosynthetic pathways.ERC Consolidator Grant, EPSRC (nanoDTC, DTA studentship), Christian Doppler Research Association, OMV Group, Royal Society Newton International Fellowship, Cluster of Excellence RESOLV (DFG) and European Unions' Horizon 202
Dual targeting of p53 and c-MYC selectively eliminates leukaemic stem cells
e Glasgow and Manchester Experimental Cancer
Medicine Centres (ECMC), which are funded by CR-UK and the Chief Scientist’s Office (Scotland). We
acknowledge the funders who have contributed to this work: MRC stratified medicine infrastructure award
(A.D.W.), CR-UK C11074/A11008 (F.P., L.E.M.H., T.L.H., A.D.W.); LLR08071 (S.A.A., E.C.); LLR11017
(M.C.); SCD/04 (M.C.); LLR13035 (S.A.A., K.D., A.D.W., and A.P.); LLR14005 (M.T.S., D.V.); KKL690 (L.E.P.);
KKL698 (P.B.); LLR08004 (A.D.W., A.P. and A.J.W.); MRC CiC (M.E.D.); The Howat Foundation (FACS
support); Friends of Paul O’Gorman (K.D. and FACS support); ELF 67954 (S.A.A.); BSH start up fund (S.A.A.);
MR/K014854/1 (K.D.)
Systemic AAV vectors for widespread and targeted gene delivery in rodents
We recently developed adeno-associated virus (AAV) capsids to facilitate efficient and noninvasive gene transfer to the central and peripheral nervous systems. However, a detailed protocol for generating and systemically delivering novel AAV variants was not previously available. In this protocol, we describe how to produce and intravenously administer AAVs to adult mice to specifically label and/or genetically manipulate cells in the nervous system and organs, including the heart. The procedure comprises three separate stages: AAV production, intravenous delivery, and evaluation of transgene expression. The protocol spans 8 d, excluding the time required to assess gene expression, and can be readily adopted by researchers with basic molecular biology, cell culture, and animal work experience. We provide guidelines for experimental design and choice of the capsid, cargo, and viral dose appropriate for the experimental aims. The procedures outlined here are adaptable to diverse biomedical applications, from anatomical and functional mapping to gene expression, silencing, and editing
Clinical Outcomes Associated with Changes in a Chronic Disease Treatment Program in an Australian Aboriginal Community
In late 1995, a treatment program for renal disease and hypertension was introduced into a remote Aboriginal community. Over the next 3.5 years, mean blood pressure levels were markedly reduced, renal function stabilised, and rates of both renal and non-renal deaths declined significantly. In 1999-2000, responsibility for the program was passed to the community's local Health Board, which subsequently faced deficiencies in clinical information systems and a shortfall in funding. After the handover, the intensity of the program declined, and compliance with medicines fell. Blood pressures in the treatment cohort increased, renal function deteriorated, and rates of deaths from natural causes subsequently rose. From 2002 to mid-2003, the adjusted risks of renal and non-renal deaths in the treatment cohort were three and 9.5 times the respective risks of people during the first 18 months of treatment in the systematic phase of the program. Sustained vigorous activity, both in treatment of people already identified and in community screening for treatment eligibility, is required to maintain good results in any chronic disease program. Adequate resources and well supported staff are essential, and constant evaluation is needed to follow outcomes and modify strategies as necessary
A preliminary randomized double blind placebo-controlled trial of intravenous immunoglobulin for Japanese encephalitis in Nepal
BACKGROUND: Japanese encephalitis (JE) virus (JEV) is a mosquito-borne flavivirus found across Asia that is closely related to West Nile virus. There is no known antiviral treatment for any flavivirus. Results from in vitro studies and animal models suggest intravenous immunoglobulin (IVIG) containing virus-specific neutralizing antibody may be effective in improving outcome in viral encephalitis. IVIG's anti-inflammatory properties may also be beneficial. METHODOLOGY/PRINCIPAL FINDINGS: We performed a pilot feasibility randomized double-blind placebo-controlled trial of IVIG containing anti-JEV neutralizing antibody (ImmunoRel, 400mg/kg/day for 5 days) in children with suspected JE at two sites in Nepal; we also examined the effect on serum neutralizing antibody titre and cytokine profiles. 22 children were recruited, 13 of whom had confirmed JE; 11 received IVIG and 11 placebo, with no protocol violations. One child (IVIG group) died during treatment and two (placebo) subsequently following hospital discharge. Overall, there was no difference in outcome between treatment groups at discharge or follow up. Passive transfer of anti-JEV antibody was seen in JEV negative children. JEV positive children treated with IVIG had JEV-specific neutralizing antibody titres approximately 16 times higher than those treated with placebo (p=0.2), which was more than could be explained by passive transfer alone. IL-4 and IL-6 were higher in the IVIG group. CONCLUSIONS/SIGNIFICANCE: A trial of IVIG for JE in Nepal is feasible. IVIG may augment the development of neutralizing antibodies in JEV positive patients. IVIG appears an appealing option for JE treatment that warrants further study. TRIAL REGISTRATION: ClinicalTrials.gov NCT01856205
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