2,583 research outputs found

    A systematic review of the impact of psychosocial factors on immunity: Implications for enhancing BCG response against tuberculosis.

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    Background: Tuberculosis (TB) remains an urgent global public health priority, causing 1.5 million deaths worldwide in 2018. There is evidence that psychosocial factors modulate immune function; however, how this may influence TB risk or BCG vaccine response, and whether this pathway can be modified through social protection, has not been investigated. This paper aims to: a) systematically review evidence of how psychosocial factors influence the expression of biomarkers of immunity, and b) apply this general evidence to propose plausible TB-specific pathways for future study. Methods: Papers reporting on the impact of psychosocial stressors on immune biomarkers in relation to infectious disease risk were identified through a search of the databases MEDLINE, PsycINFO, Global Health and PsycEXTRA alongside reference list and citation searching of key papers. Data extraction and critical appraisal were carried out using a standardised form. The findings were tabulated and synthesised narratively by infectious disease category, and used to propose plausible mechanisms for how psychosocial exposures might influence immune outcomes relevant to TB and BCG response. Results: 27,026 citations were identified, of which 51 met the inclusion criteria. The literature provides evidence of a relationship between psychosocial factors and immune biomarkers. While the direction and strength of associations is heterogenous, some overarching patterns emerged: adverse psychosocial factors (e.g. stress) were generally associated with compromised vaccine response and higher antibody titres to herpesviruses, and vice versa for positive psychosocial factors (e.g. social support). Conclusions: The evidence identifies pathways linking psychosocial factors and immune response: co-viral infection and immune suppression, both of which are potentially relevant to TB and BCG response. However, the heterogeneity in the strength and nature of the impact of psychosocial factors on immune function, and lack of research on the implications of this relationship for TB, underscore the need for TB-specific research

    Quantum Degenerate Mixture of Ytterbium and Lithium Atoms

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    We have produced a quantum degenerate mixture of fermionic alkali 6Li and bosonic spin-singlet 174Yb gases. This was achieved using sympathetic cooling of lithium atoms by evaporatively cooled ytterbium atoms in a far-off-resonant optical dipole trap. We observe co-existence of Bose condensed (T/T_c~0.8) 174Yb with 2.3*10^4 atoms and Fermi degenerate (T/T_F~0.3) 6Li with 1.2*10^4 atoms. Quasipure Bose-Einstein condensates of up to 3*10^4 174Yb atoms can be produced in single-species experiments. Our results mark a significant step toward studies of few and many-body physics with mixtures of alkali and alkaline-earth-like atoms, and for the production of paramagnetic polar molecules in the quantum regime. Our methods also establish a convenient scheme for producing quantum degenerate ytterbium atoms in a 1064nm optical dipole trap.Comment: 4 pages, 3 figure

    Sympathetic cooling in an optically trapped mixture of alkali and spin-singlet atoms

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    We report on the realization of a stable mixture of ultracold lithium and ytterbium atoms confined in a far-off-resonance optical dipole trap. We observe sympathetic cooling of 6Li by 174Yb and extract the s-wave scattering length magnitude |a6Li-174Yb| = (13 \pm 3)a0 from the rate of inter-species thermalization. Using forced evaporative cooling of 174Yb, we achieve reduction of the 6Li temperature to below the Fermi temperature, purely through inter-species sympathetic cooling.Comment: 4 pages, 3 figure

    Neutral Gas Properties and LyĪ±\alpha Escape in Extreme Green Pea Galaxies

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    Mechanisms regulating the escape of LyĪ±\alpha photons and ionizing radiation remain poorly understood. To study these processes we analyze VLA 21cm observations of one Green Pea (GP), J160810+352809 (hereafter J1608), and HST COS spectra of 17 GP galaxies at z<0.2z<0.2. All are highly ionized: J1608 has the highest [O III] Ī»5007\lambda5007/[O II] Ī»3727\lambda3727 for star-forming galaxies in SDSS, and the 17 GPs have [O III]/[O II] ā‰„6.6\geq6.6. We set an upper limit on J1608's HI mass of logā”MHI/MāŠ™=8.4\log M_{HI}/M_\odot=8.4, near or below average compared to similar mass dwarf galaxies. In the COS sample, eight GPs show LyĪ±\alpha absorption components, six of which also have LyĪ±\alpha emission. The HI column densities derived from LyĪ±\alpha absorption are high, logā”NHI/\log N_{HI}/cmāˆ’2=19āˆ’21^{-2}=19-21, well above the LyC optically thick limit. Using low-ionization absorption lines, we measure covering fractions (f_{\mbox{cov}}) of 0.1āˆ’10.1-1, and find that f_{\mbox{cov}} strongly anti-correlates with LyĪ±\alpha escape fraction. Low covering fractions may facilitate LyĪ±\alpha and LyC escape through dense neutral regions. GPs with f_{\mbox{cov}}\sim1 all have low neutral gas velocities, while GPs with lower f_{\mbox{cov}}=0.2-0.6 have a larger range of velocities. Conventional mechanical feedback may help establish low f_{\mbox{cov}} in some cases, whereas other processes may be important for GPs with low velocities. Finally, we compare f_{\mbox{cov}} with proposed indicators of LyC escape. Ionizing photon escape likely depends on a combination of neutral gas geometry and kinematics, complicating the use of emission-line diagnostics for identifying LyC emitters.Comment: 21 pages, 11 figures, accepted for publication in Ap

    Scientism recognizes evidence only of the quantitative/general variety

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    Rationale, aims and objectivesMcHugh and Walker introduced a model of knowledge to demonstrate that EBM is a form of scientism that ignores important sources of knowledge thereby impairing the practice of medicine. We study the development of this model and explore additional applications.MethodsReview of the relevant literature and identification of possible areas for fruitful application.ResultsWe show that the McHugh and Walker model is closely related to the model of evidence considered earlier by Upshur et al. We also indicate that the utility of this model is not limited to showing scientism distorts clinical practice. Several representative applications are identified, including psychotherapy, the Salk polio vaccine trial, and the placebo effect.ConclusionsPriority should be given to Upshur et al for the development of a model that has farā€reaching application to medical epistemology. It is shown that all four of the types of evidence consideredā€”qualitative/personal, qualitative/general, quantitative/general, and quantitative/personalā€”are required to adequately characterize epistemology in medical research and practice.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154650/1/jep13330_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154650/2/jep13330.pd

    Inequality of Air Quality?: A Study of Air Quality within Housing Price Brackets in Gettysburg, PA

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    With the rise of cars and other motorized vehicles has come the rise of air pollution, which tends to have disproportionate environmental and health impacts on low-income and communities of color. This study analyzes car presence and air quality on a transect within Gettysburg, PA to determine if there is a relationship between air pollution and vehicle presence, and if there is a difference in air quality between higher price bracket housing compared to campus, commercial, and lower price bracket housing. To test our research questions, we identified nine sampling locations along a transect where we measured air pollutants, including particulate matter (2.5 um and 10 um), VOCs, and NO2, with Flow by Plume Labs and Atmotube Pro air quality monitors. Our hypotheses that car activity will increase the amount of air pollution in Gettysburg and that there will be a greater environmental justice disparity within lower housing price brackets were not supported. The air quality along the transect was not greatly affected by vehicle presence and was consistent with regional conditions, and while measurements of different pollutants changed with location, there was not one clear trend between these two variables. However, there were consistently higher levels of vehicle traffic in the commercial and low-income areas than in the high-income and campus areas. The main limitations of our study were the lack of functionality and accuracy of our air monitors, which reduced the sample size of our data. These results provide room for further study of racial and child health disparities caused by cars and air pollution, as well as the impact of higher traffic levels on the risk of car and pedestrian accidents

    Dynamics of Feshbach Molecules in an Ultracold Three-Component Mixture

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    We present investigations of the formation rate and collisional stability of lithium Feshbach molecules in an ultracold three-component mixture composed of two resonantly interacting fermionic 6-Li spin states and bosonic 174-Yb. We observe long molecule lifetimes (> 100 ms) even in the presence of a large ytterbium bath and extract reaction rate coefficients of the system. We find good collisional stability of the mixture in the unitary regime, opening new possibilities for studies and probes of strongly interacting quantum gases in contact with a bath species.Comment: 5 pages, 3 figure

    A preliminary assessment into the utility of social networks for engaging local communities in climate adaptation policy: working paper prepared for NSW Office of Environment & Heritage, Sydney, Australia.

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    There has been a growing recognition regarding the use of social networks to engage the community in government actions. However, despite increasing awareness about the potential importance of social networks, there is very limited evidence for their application in relation to climate policy. This study addresses this gap by assessing the potential of social networks for engaging local communities in climate adaptation policy, drawing on a case study of the Shoalhaven region in Australia. View/download https://www.uts.edu.au/sites/default/files/Cunninghametal2014utilityofsocialnetworks.pd
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