2,257 research outputs found
Hvordan smager mĂŚlken?
De foreløbige resultater viser karakteristiske forskelle i smagen af økologisk mÌlk ved fodring med grÌsblandinger iblandet henholdsvis rødkløver, hvidkløver, lucerne eller cikorie
Sensory quality of organic milk based on grazing and high ratio of legumes in the feeding ration
Organic milk forms an important segment of the fresh milk production in Denmark. However, studies are needed to substantiate the high quality and future development of new variations of organic milk for different consumers. Differences in the composition of organically and conventionally produced milk (free fatty acids and a higher content of antioxidants in organic milk) are suggested to be a result of differences in feeding regimes (maize components in conventional production vs. grass and legumes in organic production). Also, milk from dairy cows fed grass silage has a different flavour compared to milk from dairy cows fed maize silage. This study evaluated the sensory properties of organic milk from dairy cows from different feeding trials.
The effect of four different legumes and herbs, lucerne (Medicargo sativa), red clover (Trifolium pratense), white clover (Trifolium repens) and chicory (Cichorium intybus), was studied following a schedule including 4*12 Holstein Frisian cows. Descriptive sensory analysis was performed on the fresh pasteurized unhomogenized full-fat milk (6 replicates in 2 sessions) with a trained panel of 10 assessors.
The preliminary results from the descriptive analysis of summer feeding (grazing) and winter feeding (silage) show that feeding with legumes and grass affects the sensory quality of full-fat unhomogenized organic milk. The most distinct milk was obtained from feeding ration high in chicory. This milk was characterized by a bitter and metallic taste and an astringent aftertaste both from the summer grazing and winter silage feeding trials. Red clover was characterized by a boiled milk flavour (summer), lucerne by a fatty aftertaste (winter) and white clover by a sweet and creamy flavour (winter).
The results of the first season, which will also include relations between the sensory quality and the milk composition, serve as important inputs for the extensive studies to be conducted during the next three seasons. These studies include farm studies and consumer studies (product information, preference and purchase motives)
MUSE observations of a changing-look AGN I: The re-appearance of the broad emission lines
Optical changing-look Active Galactic Nuclei (AGN) are a class of sources
that change type within a short timescale of years or decades. This change is
characterised by the appearance or disappearance of broad emission lines, often
associated with dramatic AGN continuum flux changes that are orders of
magnitude larger than those expected from typical AGN variability. In this work
we study for the first time the host galaxy of a changing-look AGN, Mrk 590,
using high spatial resolution optical and near-infrared observations. We
discover that after ~ 10 yr absence, the optical broad emission lines of Mrk
590 have reappeared. The AGN optical continuum flux however, is still ~ 10
times lower than that observed during the most luminous state in the 1990s. The
host galaxy shows a 4.5 kpc radius star-forming ring with knots of ionised and
cold molecular gas emission. Extended ionised and warm molecular gas emission
are detected in the nucleus, indicating that there is a reservoir of gas as
close as 60 pc from the black hole. We observe a nuclear gas spiral between
radii r ~ 0.5 - 2 kpc, which has been suggested as a dynamical mechanism able
to drive the necessary gas to fuel AGN. We also discover blue-shifted and high
velocity dispersion [O III] emission out to a radius of 1 kpc, tracing a
nuclear gas outflow. The gas dynamics in Mrk 590 suggest a complex balance
between gas inflow and outflow in the nucleus of the galaxy.Comment: Accepted for publication in MNRA
How to design and evaluate interventions to improve outcomes for patients with multimorbidity
Multimorbidity is a major challenge for patients and healthcare providers. The limited evidence of the effectiveness of interventions for people with multimorbidity means that there is a need for much more research and trials of potential interventions. Here we present a consensus view from a group of international researchers working to improve care for people with multimorbidity to guide future studies of interventions. We suggest that there is a need for careful consideration of whom to include, how to target interventions that address specific problems and that do not add to treatment burden, and selecting outcomes that matter both to patients and the healthcare system. Innovative design of these interventions will be necessary as many will be introduced in service settings and it will be important to ensure methodological rigour, relevance to service delivery, and generalizability across healthcare systems
Optical/near-infrared selection of red QSOs: Evidence for steep extinction curves towards galactic centers?
We present the results of a search for red QSOs using a selection based on
optical imaging from SDSS and near-infrared imaging from UKIDSS. For a sample
of 58 candidates 46 (79%) are confirmed to be QSOs. The QSOs are predominantly
dust-reddened except a handul at redshifts z>3.5. The dust is most likely
located in the QSO host galaxies. 4 (7%) of the candidates turned out to be
late-type stars, and another 4 (7%) are compact galaxies. The remaining 4
objects we could not identify. In terms of their optical spectra the QSOs are
similar to the QSOs selected in the FIRST-2MASS red Quasar survey except they
are on average fainter, more distant and only two are detected in the FIRST
survey. We estimate the amount of extinction using the SDSS QSO template
reddened by SMC-like dust. It is possible to get a good match to the observed
(restframe ultraviolet) spectra, but for nearly all the reddened QSOs it is not
possible to match the near-IR photometry from UKIDSS. The likely reasons are
that the SDSS QSO template is too red at optical wavelengths due to
contaminating host galaxy light and that the assumed SMC extinction curve is
too shallow. Our survey has demonstrated that selection of QSOs based on
near-IR photometry is an efficent way to select QSOs, including reddened QSOs,
with only small contamination from late-type stars and compact galaxies. This
will be useful with ongoing and future wide-field near-IR surveys such as the
VISTA and EUCLID surveys. [Abridged]Comment: 74 pages, 6 figures. Accepted for for publication in ApJ
Outflows and the Physical Properties of Quasars
We have investigated a sample of 5088 quasars from the Sloan Digital Sky
Survey Second Data Release in order to determine how the frequency and
properties of broad absorptions lines (BALs) depend on black hole mass,
bolometric luminosity, Eddington fraction (L/L_Edd), and spectral slope. We
focus only on high-ionization BALs and find a number of significant results.
While quasars accreting near the Eddington limit are more likely to show BALs
than lower systems, BALs are present in quasars accreting at only a
few percent Eddington. We find a stronger effect with bolometric luminosity,
such that the most luminous quasars are more likely to show BALs. There is an
additional effect, previously known, that BAL quasars are redder on average
than unabsorbed quasars. The strongest effects involving the quasar physical
properties and BAL properties are related to terminal outflow velocity. Maximum
observed outflow velocities increase with both the bolometric luminosity and
the blueness of the spectral slope, suggesting that the ultraviolet luminosity
to a great extent determines the acceleration. These results support the idea
of outflow acceleration via ultraviolet line scattering.Comment: Uses emulateapj.cls, 14 pages including 7 tables and 7 figures.
Accepted for publication in the Astrophysical Journal, Unabridged version of
Table 4 can be downloaded from http://physics.uwyo.edu/agn
High Redshift Quasars and Star Formation in the Early Universe
In order to derive information on the star formation history in the early
universe we observed 6 high-redshift (z=3.4) quasars in the near-infrared to
measure the relative iron and \mgii emission strengths. A detailed comparison
of the resulting spectra with those of low-redshift quasars show essentially
the same FeII/MgII emission ratios and very similar continuum and line spectral
properties, indicating a lack of evolution of the relative iron to magnesium
abundance of the gas since z=3.4 in bright quasars. On the basis of current
chemical evolution scenarios of galaxies, where magnesium is produced in
massive stars ending in type II SNe, while iron is formed predominantly in SNe
of type Ia with a delay of ~1 Gyr and assuming as cosmological parameters H_o =
72 km/s Mpc, Omega_M = 0.3, and Omega_Lambda = 0.7$, we conclude that major
star formation activity in the host galaxies of our z=3.4 quasars must have
started already at an epoch corresponding to z_f ~= 10, when the age of the
universe was less than 0.5 Gyrs.Comment: 29 pages, 5 figures, ApJ in pres
Phonon-mediated spin-spin interactions between trapped Rydberg atoms
We theoretically investigate the possibility of creating phonon-mediated
spin-spin interactions between neutral atoms trapped in optical tweezers. By
laser coupling the atoms to Rydberg states, collective modes of motion appear.
We show that these can be used to mediate effective spin-spin interactions or
quantum logic gates between the atoms in analogy to schemes employed in trapped
ions. In particular, we employ Rydberg dressing in a novel scheme to induce the
needed interaction, and we show that it is possible to replicate the working of
the M{\o}lmer-S{\o}rensen entanglement scheme. The M{\o}lmer-S{\o}rensen gate
is widely used in emerging quantum computers using trapped ion qubits and
currently features some of the highest fidelities of any quantum gate under
consideration. We find arbitrarily high fidelity for the coherent time
evolution of the two-atom state even at non-zero temperature.Comment: 6 pages, 3 figure
Spectroscopy of Broad Line Blazars from 1LAC
We report on optical spectroscopy of 165 Flat Spectrum Radio Quasars (FSRQs)
in the Fermi 1LAC sample, which have helped allow a nearly complete study of
this population. Fermi FSRQ show significant evidence for non-thermal emission
even in the optical; the degree depends on the gamma-ray hardness. They also
have smaller virial estimates of hole mass than the optical quasar sample. This
appears to be largely due to a preferred (axial) view of the gamma-ray FSRQ and
non-isotropic (H/R ~ 0.4) distribution of broad-line velocities. Even after
correction for this bias, the Fermi FSRQ show higher mean Eddington ratios than
the optical population. A comparison of optical spectral properties with Owens
Valley Radio Observatory radio flare activity shows no strong correlation.Comment: Accepted for publication in Ap
Determining the fraction of reddened quasars in COSMOS with multiple selection techniques from X-ray to radio wavelengths
The sub-population of quasars reddened by intrinsic or intervening clouds of
dust are known to be underrepresented in optical quasar surveys. By defining a
complete parent sample of the brightest and spatially unresolved quasars in the
COSMOS field, we quantify to which extent this sub-population is fundamental to
our understanding of the true population of quasars. By using the available
multiwavelength data of various surveys in the COSMOS field, we built a parent
sample of 33 quasars brighter than mag, identified by reliable X-ray to
radio wavelength selection techniques. Spectroscopic follow-up with the
NOT/ALFOSC was carried out for four candidate quasars that had not been
targeted previously to obtain a 100\% redshift completeness of the sample. The
population of high quasars (HAQs), a specific sub-population of quasars
selected from optical/near-infrared photometry, is found to contribute
of the parent sample. The full population of bright spatially
unresolved quasars represented by our parent sample consists of
reddened quasars defined by having , and
of the sample having assuming the extinction
curve of the Small Magellanic Cloud. We show that the HAQ selection works well
for selecting reddened quasars, but some are missed because their optical
spectra are too blue to pass the color cut in the HAQ selection. This is
either due to a low degree of dust reddening or anomalous spectra. We find that
the fraction of quasars with contributing light from the host galaxy is most
dominant at . At higher redshifts the population of spatially
unresolved quasars selected by our parent sample is found to be representative
of the full population at mag. This work quantifies the bias against
reddened quasars in studies that are based solely on optical surveys.Comment: 22 pages, 10 figures, accepted for publication in A&A. The ArXiv
abstract has been shortened for it to be printabl
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