389 research outputs found
The State of American English
lt is typical of American English that enough is almost never enough. Cecil Smith, television critic of the Los Angeles Times, considered CBS\u27 Bicentennial Minutes not merely unique but singularly unique, Senator Abraham Ribicoff of Connecticut was worried not only about nuclear proliferation but about the spread of nuclear proliferation, When there was a report that Senator Barry Goldwater had condoned organized crime in Arizona, he said it was not only ridiculous but completely untrue, in contrast to being ridiculous but true
Growth and form of the mound in Gale Crater, Mars: Slope wind enhanced erosion and transport
Ancient sediments provide archives of climate and habitability on Mars. Gale Crater, the landing site for the Mars Science Laboratory (MSL), hosts a 5-km-high sedimentary mound (Mount Sharp/Aeolis Mons). Hypotheses for mound formation include evaporitic, lacustrine, fluviodeltaic, and aeolian processes, but the origin and original extent of Gale’s mound is unknown. Here we show new measurements of sedimentary strata within the mound that indicate ∼3° outward dips oriented radially away from the mound center, inconsistent with the first three hypotheses. Moreover, although mounds are widely considered to be erosional remnants of a once crater-filling unit, we find that the Gale mound’s current form is close to its maximal extent. Instead we propose that the mound’s structure, stratigraphy, and current shape can be explained by growth in place near the center of the crater mediated by wind-topography feedbacks. Our model shows how sediment can initially accrete near the crater center far from crater-wall katabatic winds, until the increasing relief of the resulting mound generates mound-flank slope winds strong enough to erode the mound. The slope wind enhanced erosion and transport (SWEET) hypothesis indicates mound formation dominantly by aeolian deposition with limited organic carbon preservation potential, and a relatively limited role for lacustrine and fluvial activity. Morphodynamic feedbacks between wind and topography are widely applicable to a range of sedimentary and ice mounds across the Martian surface, and possibly other planets
Blood Protein Residues on Lithic Artifacts from Two Archaeological Sites in the De Long Mountains, Northwestern Alaska
Immunological analysis of blood residues was performed on 25 lithic artifacts from two archaeological sites (DEL-166 and DEL-168) in the De Long Mountains of northwestern Alaska. Blood residues occur on five artifact types: retouched flakes; end scrapers; flake burins; bifaces; and wedge-shaped microblade cores. Fourteen (56%) of the 25 analyzed artifacts react positively to six animal antisera and to human blood. Besides human blood, identified residues include the blood of sturgeon (Acipenseridae), deer (Cervidae), rabbit (Leporidae), bear (Ursus), "cat" (Felidae) and "mouse" (Rodentia). Although the application of blood residue analysis to archaeological problems is a relatively new application of an old forensic method, it may provide useful information about artifact function and animal procurement from sites where faunal remains are not preserved.On a procédé à une analyse immunologique de résidus sanguins sur 25 artefacts lithiques provenant de deux sites archéologiques (DEL-166 et DEL-168) dans les monts De Long du nord-ouest de l'Alaska. On a trouvé des résidus sanguins sur cinq types d'artefacts: éclats retouchés; grattoirs sur lame; burins faits d'éclats; bifaces; et nucléus microlames cunéiformes. Quatorze (56 p. cent) des 25 artefacts analysés ont réagi positivement à six antisérums de provenance animale et à du sang humain. Outre le sang de provenance humaine, les résidus identifiés comprennent le sang d'esturgeon (Acipenseridae), de chevreuil (Cervidae), de lapin (Leporidae), d'ours (Ursus), de «chat» (Felidae) et de «souris» (Rodentia). Bien que l'application de l'analyse de résidus sanguins à des questions d'ordre archéologique soit une application relativement nouvelle d'une ancienne méthode médico-légale, elle peut fournir des renseignements utiles sur la fonction de l'artefact et sur l'approvisionnement en animaux dans les cas de sites où les vestiges de la faune n'ont pas été conservés
Smoking inhibits the frequency of bronchovascular bundle thickening in sarcoidosis
RATIONALE/OBJECTIVES: Smoking has been associated with decreased incidence and prevalence of sarcoidosis, but few studies have evaluated effects of smoking on clinical parameters of the disease. The objectives were to determine the association of smoking with radiographic patterns and to evaluate the associations of these smoking-related radiographic patterns on airflow obstruction in sarcoidosis. METHODS: Clinical data and CT scans of 124 patients with sarcoidosis were reviewed. CT scans were assessed for lymph nodes, nodules, bronchiectasis, bronchovascular bundle thickening, displaced hilum, fibrosis, ground glass, emphysema, pleural changes, and alveolar opacities. CT patterns were compared between patients with and without a history of smoking. The effect of smoking on the associations between radiographic patterns and airflow obstruction was assessed with multivariable analysis. RESULTS: Smokers had less frequency of bronchovascular bundle thickening than nonsmokers (11/38 subjects(29%) vs. 50/86 subjects(58%),p=0.003) and more emphysema (7/38 subjects(18%) vs. 1/86 subjects(1%),p=0.001). Patients who had bronchovascular bundle thickening were less likely to have ever smoked (11/61 subjects(18%) vs. 27/63 subjects(43%), p=0.003) or be current smokers (4/61 subjects(7%) vs. 15/63 subjects(24%),p=0.008). Age (p=0.003) and bronchovascular bundle thickening (p=0.02) were independent predictors of airflow obstruction. There were no differences in smoking history between patients with airflow obstruction versus those without (10/37 subjects(27)% vs. 28/87 subjects(32%),p=0.63). CONCLUSIONS: In patients with sarcoidosis, smoking is associated with decreased frequency of bronchovascular bundle thickening, a very important clinical manifestation of the lung disease. Further, bronchovascular bundle thickening and age are the only independent predictors of airflow obstruction, and smoking does not confound these associations
Factors influencing accuracy of referral and the likelihood of false positive referral by optometrists in Bradford, United Kingdom
YesAims: Levels of false positive referral to ophthalmology departments can be high. This study
aimed to evaluate commonality between false positive referrals in order to find the factors
which may influence referral accuracy.
Methods: In 2007/08, a sample of 431 new Ophthalmology referrals from the catchment area
of Bradford Royal Infirmary were retrospectively analysed.
Results: The proportion of false positive referrals generated by optometrists decreases with
experience at a rate of 6.2% per year since registration (p < 0.0001). Community services which
involved further investigation done by the optometrist before directly referring to the hospital
were 2.7 times less likely to refer false positively than other referral formats (p = 0.007).
Male optometrists were about half as likely to generate a false positive referral than females
(OR = 0.51, p = 0.008) and as multiple/corporate practices in the Bradford area employ less
experienced and more female staff, independent practices generate about half the number of
false positive referrals (OR = 0.52, p = 0.005).
Conclusions: Clinician experience has the greatest effect on referral accuracy although there is
also a significant effect of gender with women tending to refer more false positives. This may be
due to a different approach to patient care and possibly a greater sensitivity to litigation. The
improved accuracy of community services (which often refer directly after further investigation)
supports further growth of these schemes.This study was funded by the University of Bradford
Seasonal melting and the formation of sedimentary rocks on Mars, with predictions for the Gale Crater mound
A model for the formation and distribution of sedimentary rocks on Mars is
proposed. The rate-limiting step is supply of liquid water from seasonal
melting of snow or ice. The model is run for a O(10^2) mbar pure CO2
atmosphere, dusty snow, and solar luminosity reduced by 23%. For these
conditions snow only melts near the equator, and only when obliquity >40
degrees, eccentricity >0.12, and perihelion occurs near equinox. These
requirements for melting are satisfied by 0.01-20% of the probability
distribution of Mars' past spin-orbit parameters. Total melt production is
sufficient to account for aqueous alteration of the sedimentary rocks. The
pattern of seasonal snowmelt is integrated over all spin-orbit parameters and
compared to the observed distribution of sedimentary rocks. The global
distribution of snowmelt has maxima in Valles Marineris, Meridiani Planum and
Gale Crater. These correspond to maxima in the sedimentary-rock distribution.
Higher pressures and especially higher temperatures lead to melting over a
broader range of spin-orbit parameters. The pattern of sedimentary rocks on
Mars is most consistent with a Mars paleoclimate that only rarely produced
enough meltwater to precipitate aqueous cements and indurate sediment. The
results suggest intermittency of snowmelt and long globally-dry intervals,
unfavorable for past life on Mars. This model makes testable predictions for
the Mars Science Laboratory rover at Gale Crater. Gale Crater is predicted to
be a hemispheric maximum for snowmelt on Mars.Comment: Submitted to Icarus. Minor changes from submitted versio
Protocadherin-18 Is a Novel Differentiation Marker and an Inhibitory Signaling Receptor for CD8+ Effector Memory T Cells
CD8+ tumor infiltrating T cells (TIL) lack effector-phase functions due to defective proximal TCR-mediated signaling previously shown to result from inactivation of p56lck kinase. We identify a novel interacting partner for p56lck in nonlytic TIL, Protocadherin-18 (‘pcdh18’), and show that pcdh18 is transcribed upon in vitro or in vivo activation of all CD8+ central memory T cells (CD44+CD62LhiCD127+) coincident with conversion into effector memory cells (CD44+CD62LloCD127+). Expression of pcdh18 in primary CD8+ effector cells induces the phenotype of nonlytic TIL: defective proximal TCR signaling, cytokine secretion, and cytolysis, and enhanced AICD. pcdh18 contains a motif (centered at Y842) shared with src kinases (QGQYQP) that is required for the inhibitory phenotype. Thus, pcdh18 is a novel activation marker of CD8+ memory T cells that can function as an inhibitory signaling receptor and restrict the effector phase
The third data release of the Kilo-Degree Survey and associated data products
The Kilo-Degree Survey (KiDS) is an ongoing optical wide-field imaging survey
with the OmegaCAM camera at the VLT Survey Telescope. It aims to image 1500
square degrees in four filters (ugri). The core science driver is mapping the
large-scale matter distribution in the Universe, using weak lensing shear and
photometric redshift measurements. Further science cases include galaxy
evolution, Milky Way structure, detection of high-redshift clusters, and
finding rare sources such as strong lenses and quasars. Here we present the
third public data release (DR3) and several associated data products, adding
further area, homogenized photometric calibration, photometric redshifts and
weak lensing shear measurements to the first two releases. A dedicated pipeline
embedded in the Astro-WISE information system is used for the production of the
main release. Modifications with respect to earlier releases are described in
detail. Photometric redshifts have been derived using both Bayesian template
fitting, and machine-learning techniques. For the weak lensing measurements,
optimized procedures based on the THELI data reduction and lensfit shear
measurement packages are used. In DR3 stacked ugri images, weight maps, masks,
and source lists for 292 new survey tiles (~300 sq.deg) are made available. The
multi-band catalogue, including homogenized photometry and photometric
redshifts, covers the combined DR1, DR2 and DR3 footprint of 440 survey tiles
(447 sq.deg). Limiting magnitudes are typically 24.3, 25.1, 24.9, 23.8 (5 sigma
in a 2 arcsec aperture) in ugri, respectively, and the typical r-band PSF size
is less than 0.7 arcsec. The photometric homogenization scheme ensures accurate
colors and an absolute calibration stable to ~2% for gri and ~3% in u.
Separately released are a weak lensing shear catalogue and photometric
redshifts based on two different machine-learning techniques.Comment: small modifications; 27 pages, 12 figures, accepted for publication
in Astronomy & Astrophysic
Minimal Information for Studies of Extracellular Vesicles (MISEV2023): From Basic to Advanced Approaches
Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its \u27Minimal Information for Studies of Extracellular Vesicles\u27, which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly
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