1,244 research outputs found
Leonid flashersâmeteoroid impacts on the Moon
We examine the conditions under which optical impact flashes might be observable on the Moonâs disk during the times of annual meteor shower activity. Our attention is primarily directed towards the Leonid shower given the high
probability that it will undergo repeated outburst activity during the next several years. The Leonid stream to Moon encounter geometry is discussed, and we find that the best probable times to perform optical surveys will be in 1999 and 2002. We estimate that a one kilogram Leonid meteoroid might produce a magnitude-2 optical transient on the Moonâs disk
Genetic variability of Taenia saginata inferred from mitochondrial DNA sequences
Taenia saginata is an important tapeworm, infecting humans in many parts of the world. The present study was undertaken to identify inter- and intraspecific variation of T. saginata isolated from cattle in different parts of Iran using two mitochondrial CO1 and 12S rRNA genes. Up to 105 bovine specimens of T. saginata were collected from 20 slaughterhouses in three provinces of Iran. DNA were extracted from the metacestode Cysticercus bovis. After PCR amplification, sequencing of CO1 and 12S rRNA genes were carried out and two phylogenetic analyses of the sequence data were generated by Bayesian inference on CO1 and 12S rRNA sequences. Sequence analyses of CO1 and 12S rRNA genes showed 11 and 29 representative profiles respectively. The level of pairwise nucleotide variation between individual haplotypes of CO1 gene was 0.3â2.4 % while the overall nucleotide variation among all 11 haplotypes was 4.6 %. For 12S rRNA sequence data, level of pairwise nucleotide variation was 0.2â2.5 % and the overall nucleotide variation was determined as 5.8 % among 29 haplotypes of 12S rRNA gene. Considerable genetic diversity was found in both mitochondrial genes particularly in 12S rRNA gene. © 2015, Springer-Verlag Berlin Heidelberg
Molecular and morphological characterization of the tapeworm Taenia hydatigena (Pallas, 1766) in sheep from Iran
Although Taenia hydatigena is one of the most prevalent taeniid species of livestock, very little molecular genetic information exists for this parasite. Up to 100 sheep isolates of T. hydatigena were collected from 19 abattoirs located in the provinces of Tehran, Alborz and Kerman. A calibrated microscope was used to measure the larval rostellar hook lengths. Following DNA extraction, fragments of cytochrome c oxidase 1 (CO1) and 12S rRNA genes were amplified by the polymerase chain reaction method and the amplicons were subjected to sequencing. The mean total length of large and small hooks was 203.4 Όm and 135.9 Όm, respectively. Forty CO1 and 39 12S rRNA sequence haplotypes were obtained in the study. The levels of pairwise nucleotide variation between individual haplotypes of CO1 and 12S rRNA genes were determined to be between 0.3-3.4% and 0.2-2.1%, respectively. The overall nucleotide variation among all the CO1 haplotypes was 9.7%, and for all the 12S rRNA haplotypes it was 10.1%. A significant difference was observed between rostellar hook morphometry and both CO1 and 12S rRNA sequence variability. A significantly high level of genetic variation was observed in the present study. The results showed that the 12S rRNA gene is more variable than CO1. © 2013 Cambridge University Press
On the edge of a new frontier: Is gerontological social work in the UK ready to meet twenty-first-century challenges?
This article is available open access through the publisherâs website. Copyright @ 2013 The Authors.This article explores the readiness of gerontological social work in the UK for meeting the challenges of an ageing society by investigating the focus on work with older people in social work education and the scope of gerontological social work research. The discussion draws on findings from two exploratory studies: a survey of qualifying master's programmes in England and a survey of the content relating to older people over a six-year period in four leading UK social work journals. The evidence from master's programmes suggests widespread neglect of ageing in teaching content and practice learning. Social work journals present a more nuanced picture. Older people emerge within coverage of generic policy issues for adults, such as personalisation and safeguarding, and there is good evidence of the complexity of need in late life. However, there is little attention to effective social work interventions, with an increasingly diverse older population, or to the quality of gerontological social work education. The case is made for infusing content on older people throughout the social work curriculum, for extending practice learning opportunities in social work with older people and for increasing the volume and reporting of gerontological social work research.Brunel Institute for Ageing Studie
Incarcerated Child Sexual Offenders and the Reinvention of Self through Religious and Spiritual Affiliation
Book Chapte
Electromagnetic interferences from plasmas generated in meteoroids impacts
It is shown that the plasma, generated during an impact of a meteoroid with
an artificial satellite, can produce electromagnetic radiation below the
microwave frequency range. This interference is shown to exceed local noise
sources and might disturb regular satellite operations.Comment: 6 pages, no figures. This version macthes the published versio
On the Selection of Photometric Planetary Transits
We present a new method for differentiating between planetary transits and
eclipsing binaries based on the presence of the ellipsoidal light variations.
These variations can be used to detect stellar secondaries with masses ~0.2
M_sun orbiting sun-like stars at a photometric accuracy level which has already
been achieved in transit surveys. By removing candidates exhibiting this effect
it is possible to greatly reduce the number of objects requiring spectroscopic
follow up with large telescopes. Unlike the usual candidate selection method,
which are primarily based on the estimated radius of the orbiting object, this
technique is not biased against bona-fide planets and brown dwarfs with large
radii, because the amplitude of the effect depends on the transiting object's
mass and orbital distance. In many binary systems, where a candidate planetary
transit is actually due to the partial eclipse of two normal stars, the
presence of flux variations due to the gravity darkening effect will show the
true nature of these systems. We show that many of the recent OGLE-III
photometric transit candidates exhibit the presence of significant variations
in their light curves and are likely to be due to stellar secondaries. We find
that the light curves of white dwarf transits will generally not mimic those of
small planets because of significant gravitationally induced flux variations.
We discuss the relative merits of methods used to detect transit candidates
which are due to stellar blends rather than planets. We outline how photometric
observations taken in two bands can be used to detect the presence of stellar
blends.Comment: ApJ, 11 pages, 2 figures, 1 table, replaced with accepted versio
SNPS/INDELS identification in genomic regions of abc transporters in susceptible and ivermectin-resistant Haemonchus contortus
A Fractal Analysis of the HI Emission from the Large Magellanic Cloud
A composite map of HI in the LMC using the ATCA interferometer and the Parkes
multibeam telescope was analyzed in several ways in an attempt to characterize
the structure of the neutral gas and to find an origin for it. Fourier
transform power spectra in 1D, 2D, and in the azimuthal direction were found to
be approximate power laws over 2 decades in length. Delta-variance methods also
showed the same power-law structure. Detailed models of these data were made
using line-of-sight integrals over fractals that are analogous to those
generated by simulations of turbulence with and without phase transitions. The
results suggested a way to measure directly for the first time the
line-of-sight thickness of the cool component of the HI disk of a nearly
face-on galaxy. The signature of this thickness was found to be present in all
of the measured power spectra.
The character of the HI structure in the LMC was also viewed by comparing
positive and negative images of the integrated emission. The geometric
structure of the high-emission regions was found to be filamentary, whereas the
geometric structure of the low-emission (intercloud) regions was found to be
patchy and round. This result suggests that compressive events formed the
high-emission regions, and expansion events, whether from explosions or
turbulence, formed the low-emission regions. The character of the structure was
also investigated as a function of scale using unsharp masks.
All of these results suggest that most of the ISM in the LMC is fractal,
presumably the result of pervasive turbulence, self-gravity, and self-similar
stirring.Comment: 30 pages, 21 figures, scheduled for ApJ Vol 548n1, Feb 10, 200
Reduzindo intervençÔes de rotina durante o trabalho de parto e parto: primeiro, não causar dano [Reducing routine interventions during labor and delivery: First, do no harm.]
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