49 research outputs found
Cosmic variance in [O/Fe] in the Galactic disk
We examine the distribution of the [O/Fe] abundance ratio in stars across the Galactic disk using H-band spectra from the Apache Point Galactic Evolution Experiment (APOGEE). We minimize systematic errors by considering groups of stars with similar atmospheric parameters. The APOGEE measurements in the Sloan Digital Sky Survey data release 12 reveal that the square root of the star-to-star cosmic variance in the oxygen-to-iron ratio at a given metallicity is about 0.03â0.04 dex in both the thin and thick disk. This is about twice as high as the spread found for solar twins in the immediate solar neighborhood and the difference is probably associated to the wider range of galactocentric distances spanned by APOGEE stars. We quantify the uncertainties by examining the spread among stars with the same parameters in clusters; these errors are a function of effective temperature and metallicity, ranging between 0.005 dex at 4000 K and solar metallicity, to about 0.03 dex at 4500 K and [Fe/H] â â0.6. We argue that measuring the spread in [O/Fe] and other abundance ratios provides strong constraints for models of Galactic chemical evolution
Synthesis and evaluation of fluorimetric and colorimetric chemosensors for anions based on (oligo)thienyl-thiosemicarbazones
A family of heterocyclic thiosemicarbazone dyes (3a-d) containing thienyl groups has been synthesized, characterized and their chromo-fluorogenic response in acetonitrile in the presence of selected anions studied. Acetonitrile solutions of 3a-d show absorption bands in the 338-425 nm range which are modulated by the groups attached to the thiosemicarbazone moiety. The fluoride, chloride, bromide, iodide, dihydrogen phosphate, hydrogen sulfate, nitrate, acetate and anions were used in the recognition studies. Only sensing features were observed for fluoride, cyanide, acetate and dihydrogen phosphate anions. Two different chromogenic responses were found, (i) a small shift of the absorption band due to coordination of the anions with the thiourea protons and (ii) the appearance of a new red shifted band due to deprotonation of the receptor. For the latter process changes in the color solutions from pale-yellow to orange-red were observed. Fluorescence studies showed a different emission behavior according to the number of thienyl rings in the Ï-conjugated bridges. Stability constants for the two processes (complex formation + deprotonation) for receptors 3a-d in the presence of fluoride and acetate anions were determined from spectrophotometric titrations using the HypSpec program. The interaction of 3d with fluoride was also studied through 1H NMR titrations. Semiempirical calculations to evaluate the hydrogen-donating ability of the receptors were also performed.Fundação para a CiĂȘncia e a Tecnologia (FCT) , AcçÔes Integradas Luso-Espanholas/CRUP, Generalitat Valenci
2013. Documento Sevilla de Consenso sobre Alternativas a la Transfusión de Sangre Alogénica. Actualización del Documento Sevilla
La transfusiĂłn de sangre alogĂ©nica (TSA) no es inocua, y como consecuencia han surgido mĂșltiples alternativas a la misma (ATSA). Existe variabilidad respecto a las indicaciones y buen uso de las ATSA. Dependiendo de la especialidad de los mĂ©dicos que tratan a los pacientes, el grado de anemia, la polĂtica transfusional, la disponibilidad de las ATSA y el criterio personal, estas se usan de forma variable. Puesto que las ATSA tampoco son inocuas y pueden no cumplir criterios de coste-efectividad, la variabilidad en su uso es inaceptable. Las sociedades españolas de AnestesiologĂa y ReanimaciĂłn (SEDAR), HematologĂa y Hemoterapia (SEHH), Farmacia Hospitalaria (SEFH), Medicina Intensiva y Unidades Coronarias (SEMICYUC), Trombosis y Hemostasia (SETH) y Transfusiones SanguĂneas (SETS) han elaborado un documento de consenso para el buen uso de la ATSA. Un panel de expertos de las 6 sociedades ha llevado a cabo una revisiĂłn sistemĂĄtica de la literatura mĂ©dica y elaborado el 2013. Documento Sevilla de Consenso sobre Alternativas a la TransfusiĂłn de Sangre AlogĂ©nica. Solo se contempla las ATSA dirigidas a disminuir la transfusiĂłn de concentrado de hematĂes. Se definen las ATSA como toda medida farmacolĂłgica y no farmacolĂłgica encaminada a disminuir la transfusiĂłn de concentrado de hematĂes, preservando siempre la seguridad del paciente. La cuestiĂłn principal que se plantea en cada Ătem se formula, en forma positiva o negativa, como: «La ATSA en cuestiĂłn reduce/no reduce la tasa transfusional». Para formular el grado de recomendaciĂłn se ha usado la metodologĂa Grades of Recommendation Assessment, Development and Evaluation (GRADE)
Effects of thinning intensity on radial growth patterns and temperature sensitivity in Pinus canariensis afforestations on Tenerife Island, Spain
International Consensus Document on Obstructive Sleep Apnea
El objetivo principal de este documento internacional de consenso sobre apnea obstructiva del sueno es proporcionar unas directrices que permitan a los profesionales sanitarios tomar las mejores decisiones en la asistencia de los pacientes adultos con esta enfermedad segĂșn un resumen crĂtico de la literatura mĂĄs actualizada. El grupo de trabajo de expertos se ha constituido principalmente por 17 sociedades cientĂficas y 56 especialistas con amplia representaciĂłn geogrĂĄfica (con la participaciĂłn de 4 sociedades internacionales), ademĂĄs de un metodĂłlogo experto y un documentalista del Centro Cochrane Iberoamer icano. El documento consta de un manuscrito principal, con las novedades mĂĄs relevantes del DIC, y una serie de manuscritos online que recogen las bĂșsquedas bibliogrĂĄficas sistemĂĄticas de cada uno de los apartados del DIC. Este documento no cubre la edad pediĂĄtrica ni el manejo del paciente en ventilaciĂłn mecĂĄnica crĂłnica no invasiva (que se publicarĂĄn en sendos documentos de consenso aparte)
The Submillimeter Array 1.3 mm line survey of Arp 220
We present the first aperture synthesis unbiased spectral line survey toward
an extragalactic object. The survey covered the 40 GHz frequency range between
202 and 242 GHz of the 1.3 mm atmospheric window. We find that 80% of the
observed band shows molecular emission, with 73 features identified from 15
molecular species and 6 isotopologues. The 13C isotopic substitutions of HC3N
and transitions from H2(18)O, 29SiO, and CH2CO are detected for the first time
outside the Galaxy. Within the broad observed band, we estimate that 28% of the
total measured flux is due to the molecular line contribution, with CO only
contributing 9% to the overall flux. We present maps of the CO emission at a
resolution of 2.9"x1.9" which, though not enough to resolve the two nuclei,
recover all the single-dish flux. The 40 GHz spectral scan has been modelled
assuming LTE conditions and abundances are derived for all identified species.
The chemical composition of Arp 220 shows no clear evidence of an AGN impact on
the molecular emission but seems indicative of a purely starburst-heated ISM.
The overabundance of H2S and the low isotopic ratios observed suggest a
chemically enriched environment by consecutive bursts of star formation, with
an ongoing burst at an early evolutionary stage. The large abundance of water
(~10^-5), derived from the isotopologue H2(18)O, as well as the vibrationally
excited emission from HC3N and CH3CN are claimed to be evidence of massive star
forming regions within Arp 220. Moreover, the observations put strong
constraints on the compactness of the starburst event in Arp 220. We estimate
that such emission would require ~2-8x10^6 hot cores, similar to those found in
the Sgr B2 region in the Galactic center, concentrated within the central 700
pc of Arp 220.Comment: Accepted for publication in A&
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5â7 vast areas of the tropics remain understudied.8â11 In
the American tropics, Amazonia stands out as the worldâs most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13â15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazonâs biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the regionâs vulnerability to environmental change. 15%â18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
Common variants in Alzheimerâs disease and risk stratification by polygenic risk scores
Funder: Funder: FundaciĂłn bancaria âLa Caixaâ Number: LCF/PR/PR16/51110003 Funder: Grifols SA Number: LCF/PR/PR16/51110003 Funder: European Union/EFPIA Innovative Medicines Initiative Joint Number: 115975 Funder: JPco-fuND FP-829-029 Number: 733051061Genetic discoveries of Alzheimer's disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery nâ=â409,435 and validation size nâ=â58,190). Here, we add six variants associated with Alzheimer's disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer's disease patients in APOE É4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer's disease