552 research outputs found
The Dwarf Spheroidal Companions to M31: Variable Stars in Andromeda VI
We have surveyed Andromeda VI, a dwarf spheroidal galaxy companion to M31,
for variable stars using F450W and F555W observations obtained with the Hubble
Space Telescope. A total of 118 variables were found, with 111 being RR Lyrae,
6 anomalous Cepheids, and 1 variable we were unable to classify. We find that
the Andromeda VI anomalous Cepheids have properties consistent with those of
anomalous Cepheids in other dwarf spheroidal galaxies. We revise the existing
period-luminosity relations for these variables. Further, using these and other
available data, we show that there is no clear difference between fundamental
and first-overtone anomalous Cepheids in a period-amplitude diagram at shorter
periods, unlike the RR Lyrae. For the Andromeda VI RR Lyrae, we find that they
lie close to the Oosterhoff type I Galactic globular clusters in the
period-amplitude diagram, although the mean period of the RRab stars, =
0.588 d, is slightly longer than the typical Oosterhoff type I cluster. The
mean V magnitude of the RR Lyrae in Andromeda VI is 25.29+/-0.03, resulting in
a distance 815+/-25 kpc on the Lee, Demarque, & Zinn distance scale. This is
consistent with the distance derived from the I magnitude of the tip of the red
giant branch. Similarly, the properties of the RR Lyrae indicate a mean
abundance for Andromeda VI which is consistent with that derived from the mean
red giant branch color.Comment: 23 pages, including 13 figures and 6 tables, emulateapj5/apjfonts
style. Accepted by the Astronomical Journal. We recommend the interested
reader to download the preprint with full-resolution figures, which can be
found at http://www.noao.edu/noao/staff/pritzl/M31dwarfs.htm
Heisenberg realization for U_q(sln) on the flag manifold
We give the Heisenberg realization for the quantum algebra , which
is written by the -difference operator on the flag manifold. We construct it
from the action of on the -symmetric algebra by the
Borel-Weil like approach. Our realization is applicable to the construction of
the free field realization for the [AOS].Comment: 10 pages, YITP/K-1016, plain TEX (some mistakes corrected and a
reference added
Quantum computing with antiferromagnetic spin clusters
We show that a wide range of spin clusters with antiferromagnetic
intracluster exchange interaction allows one to define a qubit. For these spin
cluster qubits, initialization, quantum gate operation, and readout are
possible using the same techniques as for single spins. Quantum gate operation
for the spin cluster qubit does not require control over the intracluster
exchange interaction. Electric and magnetic fields necessary to effect quantum
gates need only be controlled on the length scale of the spin cluster rather
than the scale for a single spin. Here, we calculate the energy gap separating
the logical qubit states from the next excited state and the matrix elements
which determine quantum gate operation times. We discuss spin cluster qubits
formed by one- and two-dimensional arrays of s=1/2 spins as well as clusters
formed by spins s>1/2. We illustrate the advantages of spin cluster qubits for
various suggested implementations of spin qubits and analyze the scaling of
decoherence time with spin cluster size.Comment: 15 pages, 7 figures; minor change
The prevalence of and factors associated with prior induced abortion among women who gave birth in Victoria, 2010-2019
OBJECTIVE: To assess the prevalence of a history of induced abortion among women who gave birth in Victoria during 2010-2019; to assess the association of socio-demographic factors with a history of induced abortion. STUDY DESIGN: Retrospective cohort study; analysis of cross-sectional perinatal data in the Victorian Perinatal Data Collection (VPDC). SETTING, PARTICIPANTS: All women who gave birth (live or stillborn) in Victoria, 1 January 2010 - 31 December 2019. MAIN OUTCOME MEASURES: Self-reported induced abortions prior to the index birth; outcome of the most recent pregnancy preceding the index pregnancy. RESULTS: Of the 766 488 women who gave birth during 2010-2019, 93 251 reported induced abortions (12.2%), including 36 938 of 338 547 nulliparous women (10.9%). Women living in inner regional (adjusted odds ratio [aOR], 0.94; 95% confidence interval [CI], 0.93-0.96) or outer regional/remote/very remote areas (aOR, 0.86; 95% CI, 0.83-0.89) were less likely than women in major cities to report induced abortions. The likelihood increased steadily with age at the index birth and with parity, and was also higher for women without partners at the index birth (aOR, 2.20; 95% CI, 2.16-2.25) and Aboriginal and Torres Strait Islander women (aOR, 1.32; 95% CI, 1.25-1.40). The likelihood was lower for women born in most areas outside Australia than for those born in Australia. The likelihood of a history of induced abortion declined across the study period overall (2019 v 2010: 0.93; 95% CI, 0.90-0.96) and for women in major cities (0.88; 95% CI, 0.84-0.91); rises in inner regional and outer regional/remote/very remote areas were not statistically significant. CONCLUSIONS: Access to abortion care in Victoria improved during 2010-2019, but the complex interplay between contraceptive use, unintended pregnancy, and induced abortion requires further exploration by remoteness of residence. Robust information about numbers of unintended pregnancies and access to reproductive health services are needed to guide national sexual and reproductive health policy and practice
Calculating the energy spectra of magnetic molecules: application of real- and spin-space symmetries
The determination of the energy spectra of small spin systems as for instance
given by magnetic molecules is a demanding numerical problem. In this work we
review numerical approaches to diagonalize the Heisenberg Hamiltonian that
employ symmetries; in particular we focus on the spin-rotational symmetry SU(2)
in combination with point-group symmetries. With these methods one is able to
block-diagonalize the Hamiltonian and thus to treat spin systems of
unprecedented size. In addition it provides a spectroscopic labeling by
irreducible representations that is helpful when interpreting transitions
induced by Electron Paramagnetic Resonance (EPR), Nuclear Magnetic Resonance
(NMR) or Inelastic Neutron Scattering (INS). It is our aim to provide the
reader with detailed knowledge on how to set up such a diagonalization scheme.Comment: 29 pages, many figure
Mutation of Rubie, a Novel Long Non-Coding RNA Located Upstream of Bmp4, Causes Vestibular Malformation in Mice
Background: The vestibular apparatus of the vertebrate inner ear uses three fluid-filled semicircular canals to sense angular acceleration of the head. Malformation of these canals disrupts the sense of balance and frequently causes circling behavior in mice. The Epistatic circler (Ecl) is a complex mutant derived from wildtype SWR/J and C57L/J mice. Ecl circling has been shown to result from the epistatic interaction of an SWR-derived locus on chromosome 14 and a C57L-derived locus on chromosome 4, but the causative genes have not been previously identified. Methodology/Principal Findings: We developed a mouse chromosome substitution strain (CSS-14) that carries an SWR/J chromosome 14 on a C57BL/10J genetic background and, like Ecl, exhibits circling behavior due to lateral semicircular canal malformation. We utilized CSS-14 to identify the chromosome 14 Ecl gene by positional cloning. Our candidate interval is located upstream of bone morphogenetic protein 4 (Bmp4) and contains an inner ear-specific, long non-coding RNA that we have designated Rubie (RNA upstream of Bmp4 expressed in inner ear). Rubie is spliced and polyadenylated, and is expressed in developing semicircular canals. However, we discovered that the SWR/J allele of Rubie is disrupted by an intronic endogenous retrovirus that causes aberrant splicing and premature polyadenylation of the transcript. Rubie lies in the conserved gene desert upstream of Bmp4, within a region previously shown to be important for inner ear expression of Bmp4. We found that the expression patterns of Bmp4 and Rubie are nearly identical in developing inner ears
Quantum Bundle Description of the Quantum Projective Spaces
We realise Heckenberger and Kolb's canonical calculus on quantum projective
(n-1)-space as the restriction of a distinguished quotient of the standard
bicovariant calculus for Cq[SUn]. We introduce a calculus on the quantum
(2n-1)-sphere in the same way. With respect to these choices of calculi, we
present quantum projective (N-1)-space as the base space of two different
quantum principal bundles, one with total space Cq[SUn], and the other with
total space Cq[S^(2n-1)]. We go on to give Cq[CP^n] the structure of a quantum
framed manifold. More specifically, we describe the module of one-forms of
Heckenberger and Kolb's calculus as an associated vector bundle to the
principal bundle with total space Cq[SUn]. Finally, we construct strong
connections for both bundles.Comment: 33 pages; minor changes, to appear in Comm. Math. Phy
Deep sequencing analysis of the developing mouse brain reveals a novel microRNA
Extent: 15p.Background: MicroRNAs (miRNAs) are small non-coding RNAs that can exert multilevel inhibition/repression at a post-transcriptional or protein synthesis level during disease or development. Characterisation of miRNAs in adult mammalian brains by deep sequencing has been reported previously. However, to date, no small RNA profiling of the developing brain has been undertaken using this method. We have performed deep sequencing and small RNA analysis of a developing (E15.5) mouse brain. Results: We identified the expression of 294 known miRNAs in the E15.5 developing mouse brain, which were mostly represented by let-7 family and other brain-specific miRNAs such as miR-9 and miR-124. We also discovered 4 putative 22-23 nt miRNAs: mm_br_e15_1181, mm_br_e15_279920, mm_br_e15_96719 and mm_br_e15_294354 each with a 70-76 nt predicted pre-miRNA. We validated the 4 putative miRNAs and further characterised one of them, mm_br_e15_1181, throughout embryogenesis. Mm_br_e15_1181 biogenesis was Dicer1-dependent and was expressed in E3.5 blastocysts and E7 whole embryos. Embryo-wide expression patterns were observed at E9.5 and E11.5 followed by a near complete loss of expression by E13.5, with expression restricted to a specialised layer of cells within the developing and early postnatal brain. Mm_br_e15_1181 was upregulated during neurodifferentiation of P19 teratocarcinoma cells. This novel miRNA has been identified as miR-3099. Conclusions: We have generated and analysed the first deep sequencing dataset of small RNA sequences of the developing mouse brain. The analysis revealed a novel miRNA, miR-3099, with potential regulatory effects on early embryogenesis, and involvement in neuronal cell differentiation/function in the brain during late embryonic and early neonatal development.King-Hwa Ling, Peter J Brautigan, Christopher N Hahn, Tasman Daish, John R Rayner, Pike-See Cheah, Joy M Raison, Sandra Piltz Jeffrey R Mann, Deidre M Mattiske, Paul Q Thomas, David L Adelson and Hamish S Scot
Recovery from depressive symptoms, state anxiety and post-traumatic stress disorder in women exposed to physical and psychological, but not to psychological intimate partner violence alone: A longitudinal study
<p>Abstract</p> <p>Background</p> <p>It is well established that intimate male partner violence (IPV) has a high impact on women's mental health. It is necessary to further investigate this impact longitudinally to assess the factors that contribute to its recovery or deterioration. The objective of this study was to assess the course of depressive, anxiety and post-traumatic stress disorder (PTSD) symptoms and suicidal behavior over a three-year follow-up in female victims of IPV.</p> <p>Methods</p> <p>Women (n = 91) who participated in our previous cross-sectional study, and who had been either physically/psychologically (n = 33) or psychologically abused (n = 23) by their male partners, were evaluated three years later. A nonabused control group of women (n = 35) was included for comparison. Information about mental health status and lifestyle variables was obtained through face-to-face structured interviews.</p> <p>Results</p> <p>Results of the follow-up study indicated that while women exposed to physical/psychological IPV recovered their mental health status with a significant decrease in depressive, anxiety and PTSD symptoms, no recovery occurred in women exposed to psychological IPV alone. The evolution of IPV was also different: while it continued across both time points in 65.21% of psychologically abused women, it continued in only 12.12% of physically/psychologically abused women while it was reduced to psychological IPV in 51.5%. Hierarchical multiple regression analyses indicated that cessation of physical IPV and perceived social support contributed to mental health recovery, while a high perception of lifetime events predicted the continuation of PTSD symptoms.</p> <p>Conclusion</p> <p>This study shows that the pattern of mental health recovery depends on the type of IPV that the women had been exposed to. While those experiencing physical/psychological IPV have a higher likelihood of undergoing a cessation or reduction of IPV over time and, therefore, could recover, women exposed to psychological IPV alone have a high probability of continued exposure to the same type of IPV with a low possibility of recovery. Thus, women exposed to psychological IPV alone need more help to escape from IPV and to recuperate their mental health. Longitudinal studies are needed to improve knowledge of factors promoting or impeding health recovery to guide the formulation of policy at individual, social and criminal justice levels.</p
Long-range chemical sensitivity in the sulfur K-edge X-ray absorption spectra of substituted thiophenes
© 2014 American Chemical Society. Thiophenes are the simplest aromatic sulfur-containing compounds and are stable and widespread in fossil fuels. Regulation of sulfur levels in fuels and emissions has become and continues to be ever more stringent as part of governments' efforts to address negative environmental impacts of sulfur dioxide. In turn, more effective removal methods are continually being sought. In a chemical sense, thiophenes are somewhat obdurate and hence their removal from fossil fuels poses problems for the industrial chemist. Sulfur K-edge X-ray absorption spectroscopy provides key information on thiophenic components in fuels. Here we present a systematic study of the spectroscopic sensitivity to chemical modifications of the thiophene system. We conclude that while the utility of sulfur K-edge X-ray absorption spectra in understanding the chemical composition of sulfur-containing fossil fuels has already been demonstrated, care must be exercised in interpreting these spectra because the assumption of an invariant spectrum for thiophenic forms may not always be valid
- …