1,827 research outputs found
The Large, Oxygen-Rich Halos of Star-Forming Galaxies Are A Major Reservoir of Galactic Metals
The circumgalactic medium (CGM) is fed by galaxy outflows and accretion of
intergalactic gas, but its mass, heavy element enrichment, and relation to
galaxy properties are poorly constrained by observations. In a survey of the
outskirts of 42 galaxies with the Cosmic Origins Spectrograph onboard the
Hubble Space Telescope, we detected ubiquitous, large (150 kiloparsec) halos of
ionized oxygen surrounding star-forming galaxies, but we find much less ionized
oxygen around galaxies with little or no star formation. This ionized CGM
contains a substantial mass of heavy elements and gas, perhaps far exceeding
the reservoirs of gas in the galaxies themselves. It is a basic component of
nearly all star-forming galaxies that is removed or transformed during the
quenching of star formation and the transition to passive evolution.Comment: This paper is part of a set of three papers on circumgalactic gas
observed with the Cosmic Origins Spectrograph on HST, to be published in
Science, together with related papers by Tripp et al. and Lehner & Howk, in
the November 18, 2011 edition. This version has not undergone final
copyediting. Please see Science online for the final printed versio
Complete homochirality induced by the nonlinear autocatalysis and recycling
A nonlinear autocatalysis of a chiral substance is shown to achieve
homochirality in a closed system, if the back-reaction is included. Asymmetry
in the concentration of two enantiomers or the enantiometric excess increases
due to the nonlinear autocatalysis. Furthermore, when the back-reaction is
taken into account, the reactant supplied by the decomposition of the
enantiomers is recycled to produce more and more the dominant one, and
eventually the homochirality is established.Comment: 4 pages, 2 figure
Business and Social Evaluation of Denial of Service Attacks in View of Scaling Economic Counter-Measures
Gas Accretion in Star-Forming Galaxies
Cold-mode gas accretion onto galaxies is a direct prediction of LCDM
simulations and provides galaxies with fuel that allows them to continue to
form stars over the lifetime of the Universe. Given its dramatic influence on a
galaxy's gas reservoir, gas accretion has to be largely responsible for how
galaxies form and evolve. Therefore, given the importance of gas accretion, it
is necessary to observe and quantify how these gas flows affect galaxy
evolution. However, observational data have yet to conclusively show that gas
accretion ubiquitously occurs at any epoch. Directly detecting gas accretion is
a challenging endeavor and we now have obtained a significant amount of
observational evidence to support it. This chapter reviews the current
observational evidence of gas accretion onto star-forming galaxies.Comment: Invited review to appear in Gas Accretion onto Galaxies, Astrophysics
and Space Science Library, eds. A. J. Fox & R. Dav\'e, to be published by
Springer. This chapter includes 22 pages with 7 Figure
A Bayesian Nonparametric Approach to Modeling Motion Patterns
The most difficult—and often most essential—
aspect of many interception and tracking tasks is constructing
motion models of the targets to be found. Experts can
often provide only partial information, and fitting parameters
for complex motion patterns can require large amounts
of training data. Specifying how to parameterize complex
motion patterns is in itself a difficult task.
In contrast, nonparametric models are very flexible and
generalize well with relatively little training data. We propose
modeling target motion patterns as a mixture of Gaussian
processes (GP) with a Dirichlet process (DP) prior over
mixture weights. The GP provides a flexible representation
for each individual motion pattern, while the DP assigns observed
trajectories to particular motion patterns. Both automatically
adjust the complexity of the motion model based
on the available data. Our approach outperforms several parametric
models on a helicopter-based car-tracking task on
data collected from the greater Boston area
Surveillance and control of meningococcal disease in the COVID-19 era: A Global Meningococcal Initiative review
RevisiónThis review article incorporates information from the 4th Global Meningococcal Initiative summit meeting. Since the introduction of stringent COVID-19 infection control and lockdown measures globally in 2020, there has been an impact on IMD prevalence, surveillance, and vaccination compliance. Incidence rates and associated mortality fell across various regions during 2020. A reduction in vaccine uptake during 2020 remains a concern globally. In addition, several Neisseria meningitidis clonal complexes, particularly CC4821 and CC11, continue to exhibit resistance to antibiotics, with resistance to ciprofloxacin or beta-lactams mainly linked to modifications of gyrA or penA alleles, respectively. Beta-lactamase acquisition was also reported through horizontal gene transfer (blaROB-1) involving other bacterial species. Despite the challenges over the past year, progress has also been made on meningococcal vaccine development, with several pentavalent (serogroups ABCWY and ACWYX) vaccines currently being studied in late-stage clinical trial programmes.Medical writing support was funded by Sanofi Pasteur.S
Exploring the views of infection consultants in England on a novel delinked funding model for antimicrobials: the SMASH study
OBJECTIVES: A novel 'subscription-type' funding model was launched in England in July 2022 for ceftazidime/avibactam and cefiderocol. We explored the views of infection consultants on important aspects of the delinked antimicrobial funding model. METHODS: An online survey was sent to all infection consultants in NHS acute hospitals in England. RESULTS: The response rate was 31.2% (235/753). Most consultants agreed the model is a welcome development (69.8%, 164/235), will improve treatment of drug-resistant infections (68.5%, 161/235) and will stimulate research and development of new antimicrobials (57.9%, 136/235). Consultants disagreed that the model would lead to reduced carbapenem use and reported increased use of cefiderocol post-implementation. The presence of an antimicrobial pharmacy team, requirement for preauthorization by infection specialists, antimicrobial stewardship ward rounds and education of infection specialists were considered the most effective antimicrobial stewardship interventions. Under the new model, 42.1% (99/235) of consultants would use these antimicrobials empirically, if risk factors for antimicrobial resistance were present (previous infection, colonization, treatment failure with carbapenems, ward outbreak, recent admission to a high-prevalence setting).Significantly higher insurance and diversity values were given to model antimicrobials compared with established treatments for carbapenem-resistant infections, while meropenem recorded the highest enablement value. Use of both 'subscription-type' model drugs for a wide range of infection sites was reported. Respondents prioritized ceftazidime/avibactam for infections by bacteria producing OXA-48 and KPC and cefiderocol for those producing MBLs and infections with Stenotrophomonas maltophilia, Acinetobacter spp. and Burkholderia cepacia. CONCLUSIONS: The 'subscription-type' model was viewed favourably by infection consultants in England
Exploring the views of infection consultants in England on a novel delinked funding model for antimicrobials: the SMASH study
OBJECTIVES: A novel ‘subscription-type’ funding model was launched in England in July 2022 for ceftazidime/avibactam and cefiderocol. We explored the views of infection consultants on important aspects of the delinked antimicrobial funding model. METHODS: An online survey was sent to all infection consultants in NHS acute hospitals in England. RESULTS: The response rate was 31.2% (235/753). Most consultants agreed the model is a welcome development (69.8%, 164/235), will improve treatment of drug-resistant infections (68.5%, 161/235) and will stimulate research and development of new antimicrobials (57.9%, 136/235). Consultants disagreed that the model would lead to reduced carbapenem use and reported increased use of cefiderocol post-implementation. The presence of an antimicrobial pharmacy team, requirement for preauthorization by infection specialists, antimicrobial stewardship ward rounds and education of infection specialists were considered the most effective antimicrobial stewardship interventions. Under the new model, 42.1% (99/235) of consultants would use these antimicrobials empirically, if risk factors for antimicrobial resistance were present (previous infection, colonization, treatment failure with carbapenems, ward outbreak, recent admission to a high-prevalence setting).
Significantly higher insurance and diversity values were given to model antimicrobials compared with established treatments for carbapenem-resistant infections, while meropenem recorded the highest enablement value. Use of both ‘subscription-type’ model drugs for a wide range of infection sites was reported. Respondents prioritized ceftazidime/avibactam for infections by bacteria producing OXA-48 and KPC and cefiderocol for those producing MBLs and infections with Stenotrophomonas maltophilia, Acinetobacter spp. and Burkholderia cepacia. CONCLUSIONS: The ‘subscription-type’ model was viewed favourably by infection consultants in England
Новые языковые реальности употребления претерита в немецком гипотаксисе
Целью статьи являются обобщение и теоретическое обоснование нового употребления претерита в относительном значении в конкретных видах придаточных предложений с презенсом в главном предложении. В статье анализируются коннотативные нюансы относительного значения претерита, регулярность замены префекта-пассива и перфекта именного составного сказуемого с глаголом "sein" на претеритальные формы в гипотаксисе, а также особое место претерита в системе немецких временных форм.Метою статті є узагальнення та теоретичне обґрунтування нового вживання претериту у релятивному значенні у конкретних видах сурядно-підрядних речень з презентом у сурядному реченні. У статті подано аналіз конототивні нюанси претериту і регулярність зміни перфекту пасиву та іменного присудка з дієсловом "sein" на претеритальні форми у гіпотаксису, а також особливе місце претериту у системі німецьких часових форм.The article aims at generalization and theoretical Explanation of modern preterit usage in relative meaning in certain types of clauses, with the Present tense in the main clause. The article deals with the analysis of connotative component meanings of the relative preterit and the regularity of substitution of preterit forms in hypotaxes for the passive perfect tense and the perfect form of the nominal compound predicate with the verb 'sein' as well as the specificity of preterit in the system of German tenses
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