1,637 research outputs found
Decision support in assessing the sustainable use of forests and other natural resources - a comparative review
The High A(V) Quasar Survey: Reddened quasi-stellar objects selected from optical/near-infrared photometry - II
Quasi-stellar objects (QSOs) whose spectral energy distributions (SEDs) are
reddened by dust either in their host galaxies or in intervening absorber
galaxies are to a large degree missed by optical color selection criteria like
the one used by the Sloan Digital Sky Survey (SDSS). To overcome this bias
against red QSOs, we employ a combined optical and near-infrared color
selection. In this paper, we present a spectroscopic follow-up campaign of a
sample of red candidate QSOs which were selected from the SDSS and the UKIRT
Infrared Deep Sky Survey (UKIDSS). The spectroscopic data and SDSS/UKIDSS
photometry are supplemented by mid-infrared photometry from the Wide-field
Infrared Survey Explorer. In our sample of 159 candidates, 154 (97%) are
confirmed to be QSOs. We use a statistical algorithm to identify sightlines
with plausible intervening absorption systems and identify nine such cases
assuming dust in the absorber similar to Large Magellanic Cloud sightlines. We
find absorption systems toward 30 QSOs, 2 of which are consistent with the
best-fit absorber redshift from the statistical modeling. Furthermore, we
observe a broad range in SED properties of the QSOs as probed by the rest-frame
2 {\mu}m flux. We find QSOs with a strong excess as well as QSOs with a large
deficit at rest-frame 2 {\mu}m relative to a QSO template. Potential solutions
to these discrepancies are discussed. Overall, our study demonstrates the high
efficiency of the optical/near-infrared selection of red QSOs.Comment: 64 pages, 18 figures, 16 pages of tables. Accepted to ApJ
Suomen geokemiallinen kartoitus
TiivistelmÀ. Tutkielma koostaa Suomessa moreenista, pohjavesistÀ, purovesistÀ ja purosedimenteistÀ tehdyt geokemialliset kartoitukset. TÀmÀn lisÀksi työssÀ kÀydÀÀn lÀpi muutama marginaalisempi kartoituksen kohde. Tiedot perustuvat Geologian tutkimuskeskuksen suorittamiin nÀytteenottoihin ja niistÀ saatuihin tuloksiin. Varsinaisen aiheen ollessa laaja, tutkielma kÀy ensisijaisesti lÀpi kysymykset mitÀ, missÀ ja milloin kartoituksia on tehty. Kartoitusten tuloksia kÀydÀÀn lÀpi suurpiirteisemmin pohdinnan muodossa
On the oxygen consumption of Mesidothea entomon (L.) (Crustacea, Isopoda)
The level of oxygen consumption of a Baltic population of Mesidothea entomon was determined in salinities of 1,6.5 and 15Ⱐand at temperatures of 5°C and 15°C using males, ovigerous females and non-ovigerous females. No significant dependence was found between respiration and salinity. The mean oxygen consumption is of the same order of magnitude as or Baltic marine isopods in general. lt decreases towards the autumn. The oxygen consumption remains at the same level independent of the oxygen concentration in the water until this falls below 2 mg per litre
Hyvinvoinnin turvaamisen rajat : NÀköaloja talouskriisiin ja hyvinvointivaltion kehitykseen Suomessa
Miten syksyllĂ€ 2008 alkanut globaali talouskriisi vaikuttaa pitkĂ€llĂ€ aikavĂ€lillĂ€ suomalaiseen hyvinvointivaltioon? Jos olisimme antiikin Kreikassa, voisimme mennĂ€ Delfoin oraakkelin luo Apollonin temppeliin ja esittÀÀ tĂ€mĂ€n kysymyksen ennuspapittarelle. ErÀÀnĂ€ lokakuun pĂ€ivĂ€nĂ€ 2009 Kelan tiloihin kokoontui joukko suomalaisia hyvinvointivaltion huippuasiantuntijoita. He kertoivat julkisen talouden, kansalaisten toimeentulon ja terveyden nĂ€kökulmista kolmelle âprofessori-oraakkelilleâ eli tanskalaiselle Nina Smithille, ruotsalaiselle Johan Fritzellille ja saksalaisille Karl Hinrichsille Suomen kokemuksista edellisestĂ€, 1990-luvun alun lamasta, sen jĂ€lkeisestĂ€ kehityksestĂ€ sekĂ€ omista tulevaisuuden arvioistaan. Seuraavana pĂ€ivĂ€nĂ€ oraakkelit lausuivat ennustuksensa, joka paljastetaan tĂ€ssĂ€ raportissa.10,00 euro
Near-infrared evolution of the equatorial ring of SN 1987A
We use adaptive-optics imaging and integral field spectroscopy from the Very
Large Telescope, together with images from the \emph{Hubble Space Telescope},
to study the near-infrared (NIR) evolution of the equatorial ring (ER) of
SN~1987A. We study the NIR line and continuum flux and morphology over time in
order to lay the groundwork for \emph{James Webb Space Telescope} observations
of the system. We also study the differences in the interacting ring structure
and flux between optical, NIR and other wavelengths, and between line and
continuum emission, to constrain the underlying physical processes. Mostly the
evolution is similar in the NIR and optical. The morphology of the ER has been
skewed toward the west side (with roughly 2/3 of the NIR emission originating
there) since around 2010. A steady decline in the ER flux, broadly similar to
the MIR and the optical, is ongoing since roughly this time as well. The
expansion velocity of the ER hotspots in the NIR is fully consistent with the
optical. However, continuum emission forms roughly 70 per cent of the NIR
luminosity, and is relatively stronger outside the hotspot-defined extent of
the ER than the optical emission or NIR line emission since 2012--2013,
suggesting a faster-expanding continuum component. We find that this outer NIR
emission can have a significant synchrotron contribution. Even if emission from
hot (2000~K) dust is dominant within the ER, the mass of this dust must
be vanishingly small (a few ~M) compared to the total
dust mass in the ER (~M) to account for the observed
flux. The NIR continuum emission, however, expands slower than the more
diffuse 180-K dust emission that dominates in the MIR, indicating a different
source, and the same hot dust component cannot account for the -band
emission.Comment: 17 pages, 17 figures. Accepted for publication in Astronomy &
Astrophysic
Metabolomic Profiling of Statin Use and Genetic Inhibition of HMG-CoA Reductase
Background Statins are first-line therapy for cardiovascular disease prevention, but their systemic effects across lipoprotein subclasses, fatty acids, and circulating metabolites remain incompletely characterized. Objectives This study sought to determine the molecular effects of statin therapy on multiple metabolic pathways. Methods Metabolic profiles based on serum nuclear magnetic resonance metabolomics were quantified at 2 time points in 4 population-based cohorts from the United Kingdom and Finland (N = 5,590; 2.5 to 23.0 years of follow-up). Concentration changes in 80 lipid and metabolite measures during follow-up were compared between 716 individuals who started statin therapy and 4,874 persistent nonusers. To further understand the pharmacological effects of statins, we used Mendelian randomization to assess associations of a genetic variant known to mimic inhibition of HMG-CoA reductase (the intended drug target) with the same lipids and metabolites for 27,914 individuals from 8 population-based cohorts. Results Starting statin therapy was associated with numerous lipoprotein and fatty acid changes, including substantial lowering of remnant cholesterol (80% relative to low-density lipoprotein cholesterol [LDL-C]), but only modest lowering of triglycerides (25% relative to LDL-C). Among fatty acids, omega-6 levels decreased the most (68% relative to LDL-C); other fatty acids were only modestly affected. No robust changes were observed for circulating amino acids, ketones, or glycolysis-related metabolites. The intricate metabolic changes associated with statin use closely matched the association pattern with rs12916 in the HMGCR gene (R2 = 0.94, slope 1.00 ± 0.03). Conclusions Statin use leads to extensive lipid changes beyond LDL-C and appears efficacious for lowering remnant cholesterol. Metabolomic profiling, however, suggested minimal effects on amino acids. The results exemplify how detailed metabolic characterization of genetic proxies for drug targets can inform indications, pleiotropic effects, and pharmacological mechanisms
Kepler423b: a half-Jupiter mass planet transiting a very old solar-like star
We report the spectroscopic confirmation of the Kepler object of interest
KOI-183.01 (Kepler-423b), a half-Jupiter mass planet transiting an old
solar-like star every 2.7 days. Our analysis is the first to combine the full
Kepler photometry (quarters 1-17) with high-precision radial velocity
measurements taken with the FIES spectrograph at the Nordic Optical Telescope.
We simultaneously modelled the photometric and spectroscopic data-sets using
Bayesian approach coupled with Markov chain Monte Carlo sampling. We found that
the Kepler pre-search data conditioned (PDC) light curve of KOI-183 exhibits
quarter-to-quarter systematic variations of the transit depth, with a
peak-to-peak amplitude of about 4.3 % and seasonal trends reoccurring every
four quarters. We attributed these systematics to an incorrect assessment of
the quarterly variation of the crowding metric. The host star KOI-183 is a G4
dwarf with M_\rm{Sun},
R_\rm{Sun}, K, dex, and with
an age of Gyr. The planet KOI-183b has a mass of
M and a radius of
R, yielding a planetary bulk
density of g/cm. The radius of KOI-183b
is consistent with both theoretical models for irradiated coreless giant
planets and expectations based on empirical laws. The inclination of the
stellar spin axis suggests that the system is aligned along the line of sight.
We detected a tentative secondary eclipse of the planet at a 2-
confidence level ( ppm) and found that the
orbit might have a small non-zero eccentricity of .
With a Bond albedo of , KOI-183b is one of the
gas-giant planets with the lowest albedo known so far.Comment: 13 pages, 13 figures, 5 tables. Accepted for publication in A&A.
Planet designation changed from KOI-183b to Kepler-423
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