1,992 research outputs found
Baryonic Tully-Fisher Relation for Extremely Low Mass Galaxies
We study Tully-Fisher relations for a sample that combines extremely faint
(M_B > -14.0) galaxies along with bright (i.e. L_*) galaxies. Accurate (~ 10%)
distances, I band photometry, and B-V colors are known for the majority of the
galaxies in our sample. The faint galaxies are drawn from the Faint Irregular
Galaxy GMRT survey (FIGGS), and we have HI rotation velocities derived from
aperture synthesis observations for all of them. For the faint galaxies, we
find that even though the median HI and stellar masses are comparable, the HI
mass correlates significantly better with the circular velocity indicators than
the stellar mass. We also find that W correlates better with mass than
the rotation velocity, although the difference is not statistically
significant. The faint galaxies lie systematically below the I band TF relation
defined by bright galaxies, and also show significantly more intrinsic scatter.
This implies that the integrated star formation in these galaxies has been both
less efficient and also less regulated than in large galaxies. We find that
while the faint end deviation is greatly reduced in Baryonic Tully-Fisher (BTF)
relations, the existence of a break at the faint end of the BTF is subject to
systematics such as the assumed stellar mass to light ratio. If we assume that
there is an intrinsic BTF and try to determine the baryonic mass by searching
for prescriptions that lead to the tightest BTF, we find that scaling the HI
mass leads to a much more significant tightening than scaling the stellar mass
to light ratio. The most significant tightening that we find however, is if we
scale the entire baryonic mass of the faint (but not the bright) galaxies. Such
a scenario would be consistent with models where dwarf (but not large) galaxies
have a large fraction of dark or ``missing'' baryons (Slightly abridged)Comment: 7 pages, 7 figures. Accepted for publication in MNRA
Resistance of three different populations of mulberry silkworm (Bombyx mori L.) to Bacillus thuringiensis
The relative resistance levels of three different populations of mulberry silkworm, Bombyx mori L. to Bacillus thuringiensis (Bt) has been studied. All three populations (two Australian and one Indonesian) were observed for similar characteristics including 3rd instar larval mortality at 24, 48, 72 and 96 h after treatment (HAT), LD50 ratio and probit mortality. Among the Australian two populations, the QuBill (yellow coloured, oval shaped cocoon) population showed higher larval mortality to Bt toxicity compared to the QuBite (white coloured, oval shaped cocoon) population. When all the populations were compared, the Insab (Indonesian population with white Coloured, peanut shaped cocoon) showed lower larval mortality and highest LD50 ratio up to 48 HAT. The Insab population also showed a 24 It longer incubation/latent period prior to the start Of Mortality
Obesity in post menopausal women with a family history of breast cancer: prevalence and risk awareness
Background: Obesity and physical activity are modifiable risk factors in the development of postmenopausal breast cancer. The aim of this study was to assess the level of awareness and prevalence of these factors in women attending family history clinics.
Methods: Women attending the breast cancer family history clinic from 2004 to 2006 completed a questionnaire (SP15 format) about their knowledge of and exposure to various diet and lifestyle factors. All women had been counselled by a Consultant Cancer Geneticist and were given verbal and written information on the effect of life style on breast cancer risk. Responses were analysed using SPSS™ software.
Results: The response rate was 70% and two thirds of women were post-menopausal. The prevalence of obesity in post-menopausal women was 37% with 40% being overweight. The majority of women consumed a healthy balanced diet. Only 15% of post-menopausal women exercised for more than 4 hours per week. Two-thirds of women correctly stated that obesity increases their breast cancer risk and 73% of these were overweight or obese. Over 87% were correctly aware of the role of family history, 68% of a high fat diet, and 57% of hormone replacement therapy in the development of breast cancer.
Conclusion: Women attending family history clinics lead a high risk lifestyle for the development of breast cancer with high prevalence of obesity and low levels of physical activity. A campaign of patient education is needed to promote healthy lifestyle choices, especially physical activity, in these high-risk women
Structure of the SMC - Stellar component distribution from 2MASS data
The spatial distribution of the SMC stellar component is investigated from
2MASS data. The morphology of the different age populations is presented. The
center of the distribution is calculated and compared with previous
estimations. The rotation of the stellar content and possible consequence of
dark matter presence are discussed. The different stellar populations are
identified through a CMD diagram of the 2MASS data. Isopleth contour maps are
produced in every case, to reveal the spatial distribution. The derived density
profiles are discussed. The older stellar population follows an exponential
profile at projected diameters of about 5 kpc (~5 deg) for the major axis and
~4 kpc for the minor axis, centred at RA: 0h:51min, Dec: -73deg 7' (J2000.0).
The centre coordinates are found the same for all the different age population
maps and are in good accordance with the kinematical centre of the SMC. However
they are found considerably different from the coordinates of the centre of the
gas distribution. The fact that the older population found on an exponential
disk, gives evidence that the stellar content is rotating, with a possible
consequence of dark matter presence. The strong interactions between the MCs
and the MilkyWay might explain the difference in the distributions of the
stellar and gas components. The lack in the observed velocity element, that
implies absence of rotation, and contradicts with the consequences of
exponential profile of the stellar component, may also be a result of the
gravitational interactions.Comment: 7 Pages, 6 figures, accepted for publication in A&
A 12-year-old boy presented with jaundice, abdominal distension and leg edema
This article has no abstract. The first 100 words appear below:
A 12-year-old immunized boy, 3rd issue of consanguineous parents, presented with jaundice for the last 4 months and gradual abdominal distension for last 2 months. Mother also mentioned the swelling of both ankles for the same duration. He had anorexia, nausea and generalized weakness. There was no history of previous jaundice, blood transfusion, surgical procedure, history of taking offending drugs, no family history of liver disease, deterioration of school performance or neuropsychiatric manifestations, bleeding manifestations, behavioral abnormality, altered consciousness or convulsion
NGC 602 Environment, Kinematics and Origins
The young star cluster NGC 602 and its associated HII region, N90, formed in
a relatively isolated and diffuse environment in the Wing of the Small
Magellanic Cloud. Its isolation from other regions of massive star formation
and the relatively simple surrounding HI shell structure allows us to constrain
the processes that may have led to its formation and to study conditions
leading to massive star formation. We use images from Hubble Space Telescope
and high resolution echelle spectrographic data from the Anglo-Australian
Telescope along with 21-cm neutral hydrogen (HI) spectrum survey data and the
shell catalogue derived from it to establish a likely evolutionary scenario
leading to the formation of NGC 602. We identify a distinct HI cloud component
that is likely the progenitor cloud of the cluster and HII region which
probably formed in blister fashion from the cloud's periphery. We also find
that the past interaction of HI shells can explain the current location and
radial velocity of the nebula. The surrounding Interstellar Medium is diffuse
and dust-poor as demonstrated by a low visual optical depth throughout the
nebula and an average HI density of the progenitor cloud estimated at 1 cm^-3.
These conditions suggest that the NGC 602 star formation event was produced by
compression and turbulence associated with HI shell interactions. It therefore
represents a single star forming event in a low gas density region.Comment: Accepted for publication in PASP. 25 pages, 10 figure
European non-communicable respiratory disease research, 2002-13: Bibliometric study of outputs and funding
©2016 Begum et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This study was conducted in order to map European research in chronic respiratory diseases (CRDs). It was intended to assist the European Commission and other research funders to identify gaps and overlaps in their portfolios, and to suggest ways in which they could improve the effectiveness of their support and increase the impact of the research on patient care and on the reduction of the incidence of the CRDs. Articles and reviews were identified in the Web of Science on research in six non-communicable respiratory diseases that were published in 2002-13 from 31 European countries. They represented only 0.8% of biomedical research output but these diseases accounted for 4.7% of the European disease burden, as measured by Disability-Adjusted Life Years (DALYs), so the sub-field is seriously under-researched. Europe is prominent in the sub-field and published 56% of the world total, with the UK the most productive and publishing more than France and Italy, the next two countries, combined. Asthma and Chronic Obstructive Pulmonary Disease (COPD) were the diseases with the most publications and the highest citation rates. They also received the most funding, with around two acknowledgments per paper (in 2009-13), whereas cystic fibrosis and emphysema averaged only one. Just over 37% of papers had no specific funding and depended on institutional support from universities and hospitals
Gas distribution, kinematics and star formation in faint dwarf galaxies
We compare the gas distribution, kinematics and the current star formation in
a sample of 10 very faint (-13.37 < M_B < -9.55) dwarf galaxies. For 5 of these
galaxies we present fresh, high sensitivity, GMRT HI 21cm observations. For all
our galaxies we construct maps of the HI column density at a constant linear
resolution of ~300 pc; this forms an excellent data set to check for the
presence of a threshold column density for star formation. We find that while
current star formation (as traced by Halpha emission) is confined to regions
with relatively large (N_HI > (0.4 -1.7) X 10^{21} atoms cm^{-2}) HI column
density, the morphology of the Halpha emission is in general not correlated
with that of the high HI column density gas. Thus, while high column density
gas may be necessary for star formation, in this sample at least, it is not
sufficient to ensure that star formation does in fact occur. We examine the
line profiles of the HI emission, but do not find a simple relation between
regions with complex line profiles and those with on-going star formation.
Finally, we examine the very fine scale (~20-100 pc) distribution of the HI
gas, and find that at these scales the emission exhibits a variety of shell
like, clumpy and filamentary features. The Halpha emission is sometimes
associated with high density HI clumps, sometimes the Halpha emission lies
inside a high density shell, and sometimes there is no correspondence between
the Halpha emission and the HI clumps. In summary, the interplay between star
formation and gas density in these galaxy does not seem to show the simple
large scale patterns observed in brighter galaxies (abridged).Comment: 15 pages, 6 tables, 13 figures. Accepted for publication in MNRA
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