7,911 research outputs found
Comparison of sulfuric and oxalic acid anodizing for preparation of thermal control coatings for spacecraft
The development of thermal control surfaces, which maintain stable solar absorptivity and infrared emissivity over long periods, is challenging due to severe conditions in low-Earth orbit (LEO). Some candidate coatings are second-surface silver-coated Teflon; second-surface, silvered optical solar reflectors made of glass or quartz; and anodized aluminum. Sulfuric acid anodized and oxalic acid anodized aluminum was evaluated under simulated LEO conditions. Oxalic acid anodizing shows promise of greater stability in LEO over long missions, such as the 30 years planned for the Space Station. However, sulfuric acid anodizing shows lower solar absorptivity
Using Social Media for Actionable Disease Surveillance and Outbreak Management: A Systematic Literature Review
published_or_final_versio
Local Luminous Infrared Galaxies. I. Spatially resolved observations with Spitzer/IRS
We present results from the Spitzer/IRS spectral mapping observations of 15
local luminous infrared galaxies (LIRGs). In this paper we investigate the
spatial variations of the mid-IR emission which includes: fine structure lines,
molecular hydrogen lines, polycyclic aromatic features (PAHs), continuum
emission and the 9.7um silicate feature. We also compare the nuclear and
integrated spectra. We find that the star formation takes place in extended
regions (several kpc) as probed by the PAH emission as well as the [NeII] and
[NeIII] emissions. The behavior of the integrated PAH emission and 9.7um
silicate feature is similar to that of local starburst galaxies. We also find
that the minima of the [NeIII]/[NeII] ratio tends to be located at the nuclei
and its value is lower than that of HII regions in our LIRGs and nearby
galaxies. It is likely that increased densities in the nuclei of LIRGs are
responsible for the smaller nuclear [NeIII]/[NeII] ratios. This includes the
possibility that some of the most massive stars in the nuclei are still
embedded in ultracompact HII regions. In a large fraction of our sample the
11.3um PAH emission appears more extended than the dust 5.5um continuum
emission. We find a dependency of the 11.3um PAH/7.7 um PAH and [NeII]/11.3um
PAH ratios with the age of the stellar populations. Smaller and larger ratios
respectively indicate recent star formation. The estimated warm (300 K < T <
1000 K) molecular hydrogen masses are of the order of 10^8 M_Sun, which are
similar to those found in ULIRGs, local starbursts and Seyfert galaxies.
Finally we find that the [NeII] velocity fields for most of the LIRGs in our
sample are compatible with a rotating disk at ~kpc scales, and they are in a
good agreement with H-alpha velocity fields.Comment: Comments: 52 pages, accepted for publicacion in ApJ
The physical and mental health of a large military cohort: baseline functional health status of the Millennium Cohort
<p>Abstract</p> <p>Background:</p> <p>The US military is currently involved in large, lengthy, and complex combat operations around the world. Effective military operations require optimal health of deployed service members, and both mental and physical health can be affected by military operations.</p> <p>Methods:</p> <p>Baseline data were collected from 77,047 US service members during 2001–2003 as part of a large, longitudinal, population-based military health study (the Millennium Cohort Study). The authors calculated unadjusted, adjusted, and weighted means for the Medical Outcomes Study Short Form 36-item Survey for Veterans physical (PCS) and mental component summary (MCS) scores over a variety of demographic and military characteristics at baseline.</p> <p>Results:</p> <p>The unadjusted mean PCS and MCS scores for this study were 53.4 (95% confidence interval: 53.3–53.4) and 52.8 (95% confidence interval: 52.7–52.9). Average PCS and MCS scores were slightly more favorable in this military sample compared to those of the US general population of the same age and sex. Factors independently associated with more favorable health status included male gender, being married, higher educational attainment, higher military rank, and Air Force service. Combat specialists had similar health status compared to other military occupations. Having been deployed to Southwest Asia, Bosnia, or Kosovo between 1998 and 2000 was not associated with diminished health status.</p> <p>Conclusion:</p> <p>The baseline health status of this large population-based military cohort is better than that of the US general population of the same age and sex distribution over the same time period, especially in older age groups. Deployment experiences during the period of 1998–2001 were not associated with decreased health status. These data will serve as a useful reference for other military health studies and for future longitudinal analyses.</p
In vivo modulation of cervicovaginal drug transporters and tissue distribution by film-released tenofovir and darunavir for topical prevention of HIV-1
We thank Gilead Science for provision of tenofovir and Janssen R&D Ireland for provision of darunavir. We thank members of the MOTIF consortium for useful discussions and exchange of ideas during the course of this study. We thank the technical staff of IDMIT, the animal care and veterinary staff at CEA, Fontenay-aux-Roses, France. Funding: this work was supported by the European Union's Seventh Programme for research, technological development and demonstration under grant agreement No 305316 as part of the MOTIF (Microbicides Formulation Through Innovative Formulation for Vaginal and Rectal Delivery) project. It has also the support of the “Investissements d’Avenir” French government program managed by the Agence Nationale de la Recherche under ANR-11-INBS-0008 funding for the Infectious Disease Models and Innovative Therapies (IDMIT, Fontenay-aux-Roses, France) infrastructure, and ANR-10-EQPX-02-01 funding for the FlowCyTech facility (IDMIT, Fontenay-aux-Roses, France).Peer reviewedPostprin
Prime Focus Spectrograph - Subaru's future -
The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and
Redshifts (SuMIRe) project has been endorsed by Japanese community as one of
the main future instruments of the Subaru 8.2-meter telescope at Mauna Kea,
Hawaii. This optical/near-infrared multi-fiber spectrograph targets cosmology
with galaxy surveys, Galactic archaeology, and studies of galaxy/AGN evolution.
Taking advantage of Subaru's wide field of view, which is further extended with
the recently completed Wide Field Corrector, PFS will enable us to carry out
multi-fiber spectroscopy of 2400 targets within 1.3 degree diameter. A
microlens is attached at each fiber entrance for F-ratio transformation into a
larger one so that difficulties of spectrograph design are eased. Fibers are
accurately placed onto target positions by positioners, each of which consists
of two stages of piezo-electric rotary motors, through iterations by using
back-illuminated fiber position measurements with a wide-field metrology
camera. Fibers then carry light to a set of four identical fast-Schmidt
spectrographs with three color arms each: the wavelength ranges from 0.38
{\mu}m to 1.3 {\mu}m will be simultaneously observed with an average resolving
power of 3000. Before and during the era of extremely large telescopes, PFS
will provide the unique capability of obtaining spectra of 2400
cosmological/astrophysical targets simultaneously with an 8-10 meter class
telescope. The PFS collaboration, led by IPMU, consists of USP/LNA in Brazil,
Caltech/JPL, Princeton, & JHU in USA, LAM in France, ASIAA in Taiwan, and
NAOJ/Subaru.Comment: 13 pages, 11 figures, submitted to "Ground-based and Airborne
Instrumentation for Astronomy IV, Ian S. McLean, Suzanne K. Ramsay, Hideki
Takami, Editors, Proc. SPIE 8446 (2012)
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Global warming and ocean stratification : a potential result of large extraterrestrial impacts
We acknowledge the support of resources provided by UK National Centre for Atmospheric Science (NCAS), the High Performance Computing Cluster supported by the Research and Specialist Computing Support service at the University of East Anglia, UK Natural Environment Research Council (NERC), grants "CPE" (NE/K014757/1), and "Paleopolar" (NE/I005722/1). Data can be obtained from MJ on request. ACM acknowledges support from an AXA Postdoctoral Fellowship and the ERC ACCI grant Project No 267760, and NERC grant NE/M018199/1.The prevailing paradigm for the climatic effects of large asteroid or comet impacts is a reduction in sunlight and significant short-term cooling caused by atmospheric aerosol loading. Here we show, using global climate model experiments, that the large increases in stratospheric water vapor that can occur upon impact with the ocean cause radiative forcings of over +20 W m−2 in the case of 10 km sized bolides. The result of such a positive forcing is rapid climatic warming, increased upper ocean stratification, and potentially disruption of upper ocean ecosystems. Since two thirds of the world's surface is ocean, we suggest that some bolide impacts may actually warm climate overall. For impacts producing both stratospheric water vapor and aerosol loading, radiative forcing by water vapor can reduce or even cancel out aerosol-induced cooling, potentially causing 1–2 decades of increased temperatures in both the upper ocean and on the land surface. Such a response, which depends on the ratio of aerosol to water vapor radiative forcing, is distinct from many previous scenarios for the climatic effects of large bolide impacts, which mostly account for cooling from aerosol loading. Finally, we discuss how water vapor forcing from bolide impacts may have contributed to two well-known phenomena: extinction across the Cretaceous/Paleogene boundary and the deglaciation of the Neoproterozoic snowball Earth.Publisher PDFPeer reviewe
A High Spatial Resolution Mid-Infrared Spectroscopic Study of the Nuclei and Star-Forming Regions in Luminous Infrared Galaxies
We present a high spatial (diffraction-limited) resolution (~0.3")
mid-infrared (MIR) spectroscopic study of the nuclei and star-forming regions
of 4 local luminous infrared galaxies (LIRGs) using T-ReCS on the Gemini South
telescope. We investigate the spatial variations of the features seen in the
N-band spectra of LIRGs on scales of ~100 pc, which allow us to separate the
AGN emission from that of the star formation (SF). We compare our Gemini T-ReCS
nuclear and integrated spectra of LIRGs with those obtained with Spitzer IRS.
The 9.7um silicate absorption feature is weaker in the nuclei of the LIRGs than
in the surrounding regions. This is probably due to the either clumpy or
compact environment of the central AGN or young, nuclear starburst. We find
that the [NeII] luminosity surface density is tightly and directly correlated
with that of Pa-alpha for the LIRG star-forming regions (slope of 1.00+-0.02).
Although the 11.3um PAH feature shows also a trend with Pa-alpha, this is not
common for all the regions. We also find that the [NeII]\Pa-alpha ratio does
not depend on the Pa-alpha equivalent width (EW), i.e., on the age of the
ionizing stellar populations, suggesting that, on the scales probed here, the
[NeII] emission line is a good tracer of the SF activity in LIRGs. On the other
hand, the 11.3um PAH\Pa-alpha ratio increases for smaller values of the
Pa-alpha EW (increasing ages), indicating that the 11.3um PAH feature can also
be excited by older stars than those responsible for the Pa-alpha emission.
Additional high spatial resolution observations are essential to investigate,
in a statistical way, the star formation in local LIRGs at the smallest scales
and to probe ultimately whether they share the same physical properties as
high-z LIRGs, ULIRGs and submillimiter galaxies.Comment: 23 pages (apjstyle), 19 figures, accepted for publicacion in Ap
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Mycolactone-dependent depletion of endothelial cell thrombomodulin is strongly associated with fibrin deposition in Buruli ulcer lesions
A well-known histopathological feature of diseased skin in Buruli ulcer (BU) is coagulative necrosis caused by the Mycobacterium ulcerans macrolide exotoxin mycolactone. Since the underlying mechanism is not known, we have investigated the effect of mycolactone on endothelial cells, focussing on the expression of surface anticoagulant molecules involved in the protein C anticoagulant pathway. Congenital deficiencies in this natural anticoagulant pathway are known to induce thrombotic complications such as purpura fulimans and spontaneous necrosis. Mycolactone profoundly decreased thrombomodulin (TM) expression on the surface of human dermal microvascular endothelial cells (HDMVEC) at doses as low as 2ng/ml and as early as 8hrs after exposure. TM activates protein C by altering thrombin's substrate specificity, and exposure of HDMVEC to mycolactone for 24 hours resulted in an almost complete loss of the cells' ability to produce activated protein C. Loss of TM was shown to be due to a previously described mechanism involving mycolactone-dependent blockade of Sec61 translocation that results in proteasome-dependent degradation of newly synthesised ER-transiting proteins. Indeed, depletion from cells determined by live-cell imaging of cells stably expressing a recombinant TM-GFP fusion protein occurred at the known turnover rate. In order to determine the relevance of these findings to BU disease, immunohistochemistry of punch biopsies from 40 BU lesions (31 ulcers, nine plaques) was performed. TM abundance was profoundly reduced in the subcutis of 78% of biopsies. Furthermore, it was confirmed that fibrin deposition is a common feature of BU lesions, particularly in the necrotic areas. These findings indicate that there is decreased ability to control thrombin generation in BU skin. Mycolactone's effects on normal endothelial cell function, including its ability to activate the protein C anticoagulant pathway are strongly associated with this. Fibrin-driven tisischemia could contribute to the development of the tissue necrosis seen in BU lesions
Automated Large Vessel Occlusion Detection Software and Thrombectomy Treatment Times: a Cluster Randomized Clinical Trial
IMPORTANCE: The benefit of endovascular stroke therapy (EVT) in large vessel occlusion (LVO) ischemic stroke is highly time dependent. Process improvements to accelerate in-hospital workflows are critical.
OBJECTIVE: to determine whether automated computed tomography (CT) angiogram interpretation coupled with secure group messaging can improve in-hospital EVT workflows.
DESIGN, SETTING, AND PARTICIPANTS: This cluster randomized stepped-wedge clinical trial took place from January 1, 2021, through February 27, 2022, at 4 comprehensive stroke centers (CSCs) in the greater Houston, Texas, area. All 443 participants with LVO stroke who presented through the emergency department were treated with EVT at the 4 CSCs. Exclusion criteria included patients presenting as transfers from an outside hospital (n = 158), in-hospital stroke (n = 39), and patients treated with EVT through randomization in a large core clinical trial (n = 3).
INTERVENTION: Artificial intelligence (AI)-enabled automated LVO detection from CT angiogram coupled with secure messaging was activated at the 4 CSCs in a random-stepped fashion. Once activated, clinicians and radiologists received real-time alerts to their mobile phones notifying them of possible LVO within minutes of CT imaging completion.
MAIN OUTCOMES AND MEASURES: Primary outcome was the effect of AI-enabled LVO detection on door-to-groin (DTG) time and was measured using a mixed-effects linear regression model, which included a random effect for cluster (CSC) and a fixed effect for exposure status (pre-AI vs post-AI). Secondary outcomes included time from hospital arrival to intravenous tissue plasminogen activator (IV tPA) bolus in eligible patients, time from initiation of CT scan to start of EVT, and hospital length of stay. In exploratory analysis, the study team evaluated the impact of AI implementation on 90-day modified Rankin Scale disability outcomes.
RESULTS: Among 243 patients who met inclusion criteria, 140 were treated during the unexposed period and 103 during the exposed period. Median age for the complete cohort was 70 (IQR, 58-79) years and 122 were female (50%). Median National Institutes of Health Stroke Scale score at presentation was 17 (IQR, 11-22) and the median DTG preexposure was 100 (IQR, 81-116) minutes. In mixed-effects linear regression, implementation of the AI algorithm was associated with a reduction in DTG time by 11.2 minutes (95% CI, -18.22 to -4.2). Time from CT scan initiation to EVT start fell by 9.8 minutes (95% CI, -16.9 to -2.6). There were no differences in IV tPA treatment times nor hospital length of stay. In multivariable logistic regression adjusted for age, National Institutes of Health Stroke scale score, and the Alberta Stroke Program Early CT Score, there was no difference in likelihood of functional independence (modified Rankin Scale score, 0-2; odds ratio, 1.3; 95% CI, 0.42-4.0).
CONCLUSIONS AND RELEVANCE: Automated LVO detection coupled with secure mobile phone application-based communication improved in-hospital acute ischemic stroke workflows. Software implementation was associated with clinically meaningful reductions in EVT treatment times.
TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05838456
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