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Firebreak (SPUR) project report: young people's views on healthy and abusive relationships
Cosmic ray feedback in the FIRE simulations: constraining cosmic ray propagation with GeV gamma ray emission
We present the implementation and the first results of cosmic ray (CR)
feedback in the Feedback In Realistic Environments (FIRE) simulations. We
investigate CR feedback in non-cosmological simulations of dwarf, sub-
starburst, and galaxies with different propagation models, including
advection, isotropic and anisotropic diffusion, and streaming along field lines
with different transport coefficients. We simulate CR diffusion and streaming
simultaneously in galaxies with high resolution, using a two moment method. We
forward-model and compare to observations of -ray emission from nearby
and starburst galaxies. We reproduce the -ray observations of dwarf and
galaxies with constant isotropic diffusion coefficient . Advection-only and streaming-only
models produce order-of-magnitude too large -ray luminosities in dwarf
and galaxies. We show that in models that match the -ray
observations, most CRs escape low-gas-density galaxies (e.g.\ dwarfs) before
significant collisional losses, while starburst galaxies are CR proton
calorimeters. While adiabatic losses can be significant, they occur only after
CRs escape galaxies, so they are only of secondary importance for -ray
emissivities. Models where CRs are ``trapped'' in the star-forming disk have
lower star formation efficiency, but these models are ruled out by -ray
observations. For models with constant that match the -ray
observations, CRs form extended halos with scale heights of several kpc to
several tens of kpc.Comment: 31 pages, 26 figures, accepted for publication in MNRA
Use of multiple primers in RAPD analysis of clonal organisms provides limited improvement in discrimination
Randomly amplified polymorphic DNA (RAPD) analysis using two or more primers has been reported to provide additional discriminatory ability over one primer used individually. This may be of particular application in epidemiological typing of clonal organisms, such as Shiga toxin-producing E. coli O157, where strain differentiation can be difficult. Using four arbitrary primers individually, and in all possible permutations, E. coli O157 isolates and other arbitrarily chosen E. coli strains were typed using RAPD analysis. For most nonclonal strains, the use of two primers resulted in increased differentiation between isolates; however, more than two primers did not increase further the discriminatory capacity. E. coli O157 isolates that produced virtually identical profiles using one primer did not show increased differentiation when using two or more primers, demonstrating that in some cases, where strains of an organism are highly related, there is limited advantage to using more than one primer in RAPD analysis
Adaptive Optics Imaging of QSOs with Double-Peaked Narrow Lines: Are they Dual AGNs?
Active galaxies hosting two accreting and merging super-massive black holes
(SMBHs) -- dual Active Galactic Nuclei (AGN) -- are predicted by many current
and popular models of black hole-galaxy co-evolution. We present here the
results of a program that has identified a set of probable dual AGN candidates
based on near Infra-red (NIR) Laser Guide-Star Adaptive Optics (LGS AO) imaging
with the Keck II telescope. These candidates are selected from a complete
sample of radio-quiet Quasi-stellar Objects (QSOs) drawn from the Sloan Digital
Sky Survey (SDSS), which show double-peaked narrow AGN emission lines. Of the
twelve AGNs imaged, we find six with double galaxy structure, of which four are
in galaxy mergers. We measure the ionization of the two velocity components in
the narrow AGN lines to test the hypothesis that both velocity components come
from an active nucleus. The combination of a well-defined parent sample and
high-quality imaging allows us to place constraints on the fraction of SDSS
QSOs that host dual accreting black holes separated on kiloparsec (kpc) scales:
~0.3%-0.65%. We derive from this fraction the time spent in a QSO phase during
a typical merger and find a value that is much lower than estimates that arise
from QSO space densities and galaxy merger statistics. We discuss possible
reasons for this difference. Finally, we compare the SMBH mass distributions of
single and dual AGN and find little difference between the two within the
limited statistics of our program, hinting that most SMBH growth happens in the
later stages of a merger process.Comment: 9 pages, 4 figures, 1 table; accepted to the Astrophysical Journa
Dairy and hog farming in northeastern Iowa
On Northeastern Iowa dairy and hog farms, highest returns were obtained where the number of milk cows equaled litters of pigs. This meant about 6 pounds of hogs were produced to each pound of butterfat. Where hog production was less, returns were lower. The butterfat-hog price ratio, during the years of the study, favored hogs, with 1 pound butterfat worth only 3.5 pounds of hogs.
Generally, the strictly dairy herds were more profitable than the dual-purpose herds, even though butterfat prices were unfavorable in comparison to beef, during the period studied. Income from beef in the dual-purpose herds was not enough to offset the lower sales of butterfat.
The dairy herds, with 16.6 cows, averaged 229 pounds butterfat sold or used in the household, and 493 pounds beef per cow, while the dual-purpose herds, with 14.1 cows, averaged 162 pounds butterfat output and 711 pounds beef per cow
An economic study of the dairy enterprise in northeastern Iowa
In a study of 51 dairy and dual-purpose herds in 1935 and ] 936 it was found that the average value per head of the milk cows was 49 in the low producing ones; while investment in buildings and fences was 90 in the low producing herds. Investment per pound of butterfat produced, however , was lower with the higher producing and more valuable cows.
The cows in the higher producing herds were fed more heavily and received better balanced rations; the total amount of concentrates amounting to approximately 2,300 pounds in the high and 1,200 in the low producing herds, while total value of all feeds plus pasture amounted to 50. When expressed per pound of butterfat, however, the values of feed and pasture were but little different between the high and low producing herds. In fact, the advantage was slightly with the high producing herds.
There was a wide variation in amount of feed fed per cow, which was only partly related to the production per cow. The cows receiving the most feed generally produced more butterfat but not necessarily in proportion to the difference in amount of feed. Consequently, the cows receiving the most feed did not give the highest return per $100 of feed fed
The origin of ultra diffuse galaxies: stellar feedback and quenching
We test if the cosmological zoom-in simulations of isolated galaxies from the
FIRE project reproduce the properties of ultra diffuse galaxies. We show that
stellar feedback-generated outflows that dynamically heat galactic stars,
together with a passively aging stellar population after imposed quenching
(from e.g. infall into a galaxy cluster), naturally reproduce the observed
population of red UDGs, without the need for high spin halos or dynamical
influence from their host cluster. We reproduce the range of surface
brightness, radius and absolute magnitude of the observed z=0 red UDGs by
quenching simulated galaxies at a range of different times. They represent a
mostly uniform population of dark matter-dominated galaxies with M_star ~1e8
Msun, low metallicity and a broad range of ages. The most massive simulated
UDGs require earliest quenching and are therefore the oldest. Our simulations
provide a good match to the central enclosed masses and the velocity
dispersions of the observed UDGs (20-50 km/s). The enclosed masses of the
simulated UDGs remain largely fixed across a broad range of quenching times
because the central regions of their dark matter halos complete their growth
early. A typical UDG forms in a dwarf halo mass range of Mh~4e10-1e11 Msun. The
most massive red UDG in our sample requires quenching at z~3 when its halo
reached Mh ~ 1e11 Msun. If it, instead, continues growing in the field, by z=0
its halo mass reaches > 5e11 Msun, comparable to the halo of an L* galaxy. If
our simulated dwarfs are not quenched, they evolve into bluer low-surface
brightness galaxies with mass-to-light ratios similar to observed field dwarfs.
While our simulation sample covers a limited range of formation histories and
halo masses, we predict that UDG is a common, and perhaps even dominant, galaxy
type around Ms~1e8 Msun, both in the field and in clusters.Comment: 20 pages, 13 figures; match the MNRAS accepted versio
Exploring the interdependencies of research funders in the UK
Investment in medical research is vital to the continuing improvement of the UK's health and wealth. It is through research that we expand our understanding of disease and develop new treatments for patients. Medical research charities currently contribute over £1 billion annually to medical research in the UK, of which over £350 million is provided by Cancer Research UK. Many charities,
including Cancer Research UK, receive no government funding for their research
activity.
Cancer Research UK is engaged in a programme of work in order to better understand the medical research funding environment and demonstrate the importance of sustained investment. A key part of that is the Office of Health
Economics‟ (OHE) 2011 report “Exploring the interdependency between public and charitable medical research”. This study found that there are substantial
benefits, both financial and qualitative, from the existence of a variety of funders and that reductions in the level of government financial support for medical
research are likely to have broader negative effects.
This contributed to other evidence which found that the activities and funding of the charity, public and private sectors respectively are complementary, i.e. mutually reinforcing, rather than duplicative or merely substituting for one another.
“Exploring the interdependencies of research funders in the UK” by the Office of Health Economics (OHE) and SPRU: Science and Technology Policy Research at the University of Sussex, represents a continued effort to build the evidence base around the funding of medical research.
This report uncovers the extent to which funders of cancer research are interdependent, nationally and internationally. Key figures show that two
thirds of publications acknowledging external support have relied on multiple funders, while just under half benefited from overseas funding, and almost a fifth are also supported by industry. In addition the analysis
shows that the general public would not want tax funding of cancer research to be reduced, but would not donate enough to charities to compensate for any such reduction
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