321 research outputs found
Climate Change: Anticipated Effects on High-Energy Laser Weapon Systems in Maritime Environments
anticipated effects on high energy laser weapon systems in maritime environments. Journal of Applied Meteorology and Climatology, American Meteorological Society, 50, 153-166This study quantiïŹes the potential impacts on ship-defense high-energy-laser (HEL) performance due to
atmospheric effects in the marine boundary layer driven by recent observations and analysis of worldwide sea
surface temperatures (SSTs). The atmospheric effects are deïŹned using the worldwide probabilistic climatic
database available in the High Energy Laser End-to-End Operational Simulation (HELEEOS) model, which
includes an SST database for the period 1854â1997. A more recent worldwide sea surface temperature database was provided by the Naval Postgraduate School for the period 1990-2008. Mean differences and trends between the two SST databases are used to deduce possible climate change impacts on simulated maritime HEL engagements. The anticipated effects on HEL propagation performance are assessed at an operating wave-length of 1.0642 um across the world's oceans and mapped to a 1 degree x 1 degree grid. The scenario evaluated is near surface and nearly horizontal over a range of 5000 m in which anticipated clear-air maritime aerosols occur. Summer and winter scenarios are considered. In addition to realistic vertical profiles of molecular and aerosol absorption and scattering, correlated optical turbulence profiles in probabilistic (percentile) format are used
Paradoxical relationship between proton pump inhibitors and COVID-19: A systematic review and meta-analysis
BACKGROUND The proton pump inhibitors (PPIs), used to reduce gastric acid secretion, represent one of the most widely used pharmaceutical classes in the world. Their consumption as a risk factor for the evolution of severe forms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been investigated patients. These risks also appear to be linked to the duration and the dosage. On the other hand, several studies have emerged with regard to the protective or therapeutic effects of these drugs. More and more evidence underlines the immunomodulatory and anti-fibrotic role of PPIs. In addition, their ability to alkalize the contents of endosomes and lysosomes serves as an obstacle to the entry of the virus into the host cells.AIMTo identify studies on the relationship between the intake of PPIs and coronavirus disease 2019 (COVID-19) in patients affected by SARS-CoV-2 infection, with the main objective of evaluating the outcomes related to severity and mortality. METHODS A literature review was performed in November 2020. The MEDLINE/PubMed, Cochrane Library, EMBASE and Google Scholar databases were searched for all relevant articles published in English on this topic. The search terms were identified by means of controlled vocabularies, such as the National Library of Medicineâs MESH (Medical Subject Headings) and keywords. The MESH terms and keywords used were as follows: âCOVID-19â, âproton pump inhibitorsâ, âPPIsâ, âSARS-CoV-2â, âoutcomesâ, âseverityâ and âmortalityâ. The inclusion criteria regarding the studies considered in our analysis were: meta-analysis, casecontrol, hospital-based case-control, population-based case-control, retrospective studies, online survey, as well as cohort-studies, while articles not published as full reports, such as conference abstracts, case reports and editorials were excluded. We tried to summarize and pool all the data if available. RESULTS A total of 9 studies were found that described the use of PPIs, of which only 5 clearly reported the severity and mortality data in SARS-CoV-2 patients. Our pooled incidence analysis of severe events did not differ between patients with and without PPIs (odds ratio 1.65, 95% confidence interval: 0.62-4.35) (P = 0.314), or for mortality (odds ratio 1.77, 95% confidence interval: 0.62-5.03) (P = 0.286). CONCLUSION Detailed and larger case studies are needed to accurately understand the role of PPIs in this viral infection
Methodological issues in a cross-sectional survey on cervical cancer screening using telephone interviews in Sicily (Italy): a SWOT analysis
Objective: A cross-sectional study on knowledge, perceptions, and adherence to cervical cancer screening was conducted using telephone interviews of Sicilian women that were performed in 2016. This study aimed to identify areas that need to be addressed to improve the validity of data collection and to minimize possible biases. Methods: We performed a qualitative study through SWOT analysis, which is a multidimensional method based on evaluation of Strengths (S), Weaknesses (W), Opportunities (O), and Threats (T) of the research project. The contents of the SWOT forms underwent categorical, inductive, and deductive data analysis using the long table analysis method. Results: The full availability of an updated address and phone number list was the main organizational aspect to be addressed. Socio-cultural context played a major role for understanding the questions and for acceptability of the topics. In some cases, a family member was a facilitating element, while in others, the family member hindered the interviews. Active involvement of general practitioners was considered essential for success of the interviews. Conclusions: When performing a cross-sectional survey, organizational aspects and active involvement of general practitioners are crucial in the enrolment phase, regardless of the socio-cultural context
The Sensitivity of HAWC to High-Mass Dark Matter Annihilations
The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view
detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in
central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC
will observe gamma rays and cosmic rays with an array of water Cherenkov
detectors. The full HAWC array is scheduled to be operational in Spring 2015.
In this paper, we study the HAWC sensitivity to the gamma-ray signatures of
high-mass (multi- TeV) dark matter annihilation. The HAWC observatory will be
sensitive to diverse searches for dark matter annihilation, including
annihilation from extended dark matter sources, the diffuse gamma-ray emission
from dark matter annihilation, and gamma-ray emission from non-luminous dark
matter subhalos. Here we consider the HAWC sensitivity to a subset of these
sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the
Galactic center. We simulate the HAWC response to gamma rays from these sources
in several well-motivated dark matter annihilation channels. If no gamma-ray
excess is observed, we show the limits HAWC can place on the dark matter
cross-section from these sources. In particular, in the case of dark matter
annihilation into gauge bosons, HAWC will be able to detect a narrow range of
dark matter masses to cross-sections below thermal. HAWC should also be
sensitive to non-thermal cross-sections for masses up to nearly 1000 TeV. The
constraints placed by HAWC on the dark matter cross-section from known sources
should be competitive with current limits in the mass range where HAWC has
similar sensitivity. HAWC can additionally explore higher dark matter masses
than are currently constrained.Comment: 15 pages, 4 figures, version to be published in PR
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