1,487 research outputs found
Comparing men's and womens' experiences of multiple exclusion homelessness
This article explores gender as a variable in multiple exclusion homelessness in England. Much past research has taken insufficient account of the gender of homeless people, especially the predominance of men in the single homeless population and of women heading homeless households with dependent children. Drawing on qualitative data generated in a study of multiple exclusion homelessness in London and Nottingham, the article considers three ways in which gender may act as a homelessness variable: in people's susceptibility to homelessness, in their experiences of homelessness and in their encounters with accommodation services. By comparing the accounts of homeless men and women with complex support needs with evidence from staff working for support agencies, the overall aim of the article is to offer a critical examination of the gendered assumptions of homelessness policy and practice
One Loop Predictions of the Finely Tuned SSM
We study the finely tuned SSM, recently proposed by Arkani-Hamed and
Dimopoulos, at the one loop level. The runnings of the four gaugino Yukawa
couplings, the mu term, the gaugino masses, and the Higgs quartic coupling are
computed. The Higgs mass is found to be 130 - 170 GeV for M_s > 10^6 GeV. If
the Yukawa coupling constants are measured at the 1% level, this can determine
the SUSY breaking scale to within an order of magnitude. Measuring the
relationships between the couplings to this accuracy provides a striking signal
for this model.Comment: 5 pages, 4 figures; v2: Minor corrections to anomalous dimensions and
beta functions. Numerical results are not significantly affected. v3: Minor
changes to figures and references, as published in PR
A Directly-Written Monolithic Waveguide-Laser Incorporating a DFB Waveguide-Bragg Grating
We report the fabrication and performance of the first C-band
directly-written monolithic waveguide-laser. The waveguide-laser device was
created in an Erbium and Ytterbium doped phosphate glass host and consisted of
an optical waveguide that included a distributed feedback Bragg grating
structure. The femtosecond laser direct-write technique was used to create both
the waveguide and the waveguide-Bragg grating simultaneously and in a single
processing step. The waveguide-laser was optically pumped at approximately 980
nm and lased at 1537nm with a bandwidth of less than 4 pm.Comment: 6 pages, 13 references, 4 figure
A 100 mW monolithic Yb waveguide laser fabricated using the femtosecond laser direct-write technique
A femtosecond laser-written monolithic waveguide laser (WGL) oscillator based
on a distributed feedback (DFB) architecture and fabricated in ytterbium doped
phosphate glass is reported. The device lased at 1033 nm with an output power
of 102 mW and a bandwidth less than 2 pm when bidirectionally pumped at 976 nm.
The WGL device was stable and operated for 50 hours without degradation. This
demonstration of a high performance WGL opens the possibility for creating a
variety of narrow-linewidth laser designs in bulk glasses.Comment: 5 pages, 3 figures, submitted journal manuscrip
Effects of immunization against bone morphogenetic protein-15 and growth differentiation factor-9 on ovarian function in mares
Currently there is no contraceptive vaccine that can cause permanent sterility in mares. This study investigates the effect of vaccination against oocyte-specific growth factors, Bone Morphogenetic Protein 15 (BMP-15) and Growth Differentiation Factor 9 (GDF-9), on ovarian function of mares. It was hypothesized that immunization against these growth factors would prevent ovulation and/or accelerate depletion of the oocyte reserve. For this study, 30 mares were randomly assigned to three groups (n=10/group) and vaccinated with BMP-15 or GDF-9 peptides conjugated to KLH and adjuvant, or a control of phosphate buffered saline and adjuvant. Horses received vaccinations at weeks 0, 6, 12, and 18. Ovarian activity and estrous behavior were evaluated 3 days a week via ultrasonography and interaction with a stallion. The study was initiated on March1, 2016. Upon evaluation of ovulation rate, the GDF-9 group did not have a difference (P=0.66) in ovulation rate when compared to controls (10.8 and 10.0 ovulations, respectively), but the number of ovulations in the BMP-15 group was less (P=0.02; 4.9 ovulations). Average follicle size prior to ovulation was less (P \u3c 0.0001) in both treatment groups compared to controls. Estrous behavior was altered in both the BMP-15 and GDF-9 groups compared to controls after the second vaccination (P=0.05 and 0.03, respectively). Although further research is required to determine the continued effects of vaccination against GDF-9 on ovulation rates, these results indicate that vaccination against BMP-15 and GDF-9 could serve as a contraceptive in wild horse populations
A Cepheid Distance to NGC 4603 in Centaurus
In an attempt to use Cepheid variables to determine the distance to the
Centaurus cluster, we have obtained images of NGC 4603 with the Hubble Space
Telescope on 9 epochs using WFPC2 and the F555W and F814W filters. This galaxy
has been suggested to lie within the ``Cen30'' portion of the cluster and is
the most distant object for which this method has been attempted. Previous
distance estimates for Cen30 have varied significantly and some have presented
disagreements with the peculiar velocity predicted from redshift surveys,
motivating this investigation. Using our observations, we have found 61
candidate Cepheid variable stars; however, a significant fraction of these
candidates are likely to be nonvariable stars whose magnitude measurement
errors happen to fit a Cepheid light curve of significant amplitude for some
choice of period and phase. Through a maximum likelihood technique, we
determine that we have observed 43 +/- 7 real Cepheids and that NGC 4603 has a
distance modulus of 32.61 +0.11/-0.10 (random, 1 sigma) +0.24/-0.25
(systematic, adding in quadrature), corresponding to a distance of 33.3 Mpc.
This is consistent with a number of recent estimates of the distance to NGC
4603 or Cen30 and implies a small peculiar velocity consistent with predictions
from the IRAS 1.2 Jy redshift survey if the galaxy lies in the foreground of
the cluster.Comment: Accepted for publication in the Astrophysical Journal. 17 pages with
17 embedded figures and 3 tables using emulateapj.sty. Additional figures and
images may be obtained from http://astro.berkeley.edu/~marc/n4603
H-ATLAS/GAMA and HeViCS - dusty early-type galaxies in different environments
NKA acknowledges the support of the Science and Technology Facilities Council. LD, RJI and SJM acknowledge support from the European Research Council Advanced Grant COSMICISM. IDL gratefully acknowledges the support of the Flemish Fund for Scientific Research (FWO-Vlaanderen). KR acknowledges support from the European Research Council Starting Grant SEDmorph (P.I. V. Wild). Date of acceptance: 22/05/2015The Herschel Space Observatory has had a tremendous impact on the study of extragalactic dust. Specifically, early-type galaxies (ETG) have been the focus of several studies. In this paper, we combine results from two Herschel studies -a Virgo cluster study Herschel Virgo Cluster Survey (HeViCS) and a broader, low-redshift Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS)/Galaxy and Mass Assembly (GAMA) study -and contrast the dust and associated properties for similar mass galaxies. This comparison is motivated by differences in results exhibited between multiple Herschel studies of ETG. A comparison between consistent modified blackbody derived dust mass is carried out, revealing strong differences between the two samples in both dust mass and dust-to-stellar mass ratio. In particular, the HeViCS sample lacks massive ETG with as high a specific dust content as found in H-ATLAS. This is most likely connected with the difference in environment for the two samples. We calculate nearest neighbour environment densities in a consistent way, showing that H-ATLAS ETG occupy sparser regions of the local Universe, whereas HeViCS ETG occupy dense regions. This is also true for ETG that are not Herschel-detected but are in the Virgo and GAMA parent samples. Spectral energy distributions are fit to the panchromatic data. From these, we find that in H-ATLAS the specific star formation rate anticorrelates with stellar mass and reaches values as high as in our Galaxy. On the other hand HeViCS ETG appear to have little star formation. Based on the trends found here, H-ATLAS ETG are thought to have more extended star formation histories and a younger stellar population than HeViCS ETG.Publisher PDFPeer reviewe
Chandra Detection of a TypeII Quasar at z=3.288
We report on observations of a TypeII quasar at redshift z=3.288, identified
as a hard X-ray source in a 185 ks observation with the Chandra X-ray
Observatory and as a high-redshift photometric candidate from deep, multiband
optical imaging. CXOJ084837.9+445352 (hereinafter CXO52) shows an unusually
hard X-ray spectrum from which we infer an absorbing column density N(H) =
(4.8+/-2.1)e23 / cm2 (90% confidence) and an implied unabsorbed 2-10 keV
rest-frame luminosity of L(2-10) = 3.3e44 ergs/s, well within the quasar
regime. Hubble Space Telescope imaging shows CXO52 to be elongated with slight
morphological differences between the WFPC2 F814W and NICMOS F160W bands.
Optical and near-infrared spectroscopy of CXO52 show high-ionization emission
lines with velocity widths ~1000 km/s and flux ratios similar to a Seyfert2
galaxy or radio galaxy. The latter are the only class of high-redshift TypeII
luminous AGN which have been extensively studied to date. Unlike radio
galaxies, however, CXO52 is radio quiet, remaining undetected at radio
wavelengths to fairly deep limits, f(4.8GHz) < 40 microJy. High-redshift TypeII
quasars, expected from unification models of active galaxies and long-thought
necessary to explain the X-ray background, are poorly constrained
observationally with few such systems known. We discuss recent observations of
similar TypeII quasars and detail search techniques for such systems: namely
(1) X-ray selection, (2) radio selection, (3) multi-color imaging selection,
and (4) narrow-band imaging selection. Such studies are likely to begin
identifying luminous, high-redshift TypeII systems in large numbers. We discuss
the prospects for these studies and their implications to our understanding of
the X-ray background.Comment: 28 pages, 5 figures; to appear in The Astrophysical Journa
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