1,593 research outputs found
Brorfelde Schmidt CCD Catalog (BSCC)
The Brorfelde Schmidt CCD Catalog (BSCC) contains about 13.7 million stars,
north of +49 deg Declination with precise positions and V, R photometry. The
catalog has been constructed from the reductions of 18,667 CCD frames observed
with the Brorfelde Schmidt Telescope between 2000 and 2007. The Tycho-2 catalog
was used for astrometric and photometric reference stars. Errors of individual
positions are about 20 to 200 mas for stars in the R = 10 to 18 mag range.
External comparisons with 2MASS and SDSS reveal possible small systematic
errors in the BSCC of up to about 30 mas. The catalog is supplemented with J,
H, and K_s magnitudes from the 2MASS catalog. The catalog data file (about 550
MB ASCII, compressed) will be made available at the Strasbourg Data Center
(CDS).Comment: 16 pages, 22 figures, 2 tables, accepted by A
Regular obstructed categories and TQFT
A proposal of the concept of -regular obstructed categories is given. The
corresponding regularity conditions for mappings, morphisms and related
structures in categories are considered. An n-regular TQFT is introduced. It is
shown the connection of time reversibility with the regularity.Comment: 22 pages in Latex. To be published in J. Math. Phy
Species distribution modeling reveals strongholds and potential reintroduction areas for the world's largest eagle
The highly interactive nature of predator-prey relationship is essential for ecosystem conservation; predators have been extirpated, however, from entire ecosystems all over the Earth. Reintroductions comprise a management technique to reverse this trend. Species Distribution Models (SDM) are preemptive tools for release-site selection, and can define levels of habitat quality over the species distribution. The Atlantic Forest of South America has lost most of its apex predators, and Harpy Eagles Harpia harpyja-Earth's largest eagle-are now limited to few forest pockets in this domain. Harpy Eagles are supposedly widespread in the Amazon Forest, however, where habitat loss and degradation is advancing at a rapid pace. We aim to describe the suitability of threatened Amazonian landscapes for this eagle. We also aim to assess the suitability of remaining Atlantic Forest sites for Harpy Eagle reintroductions. Here we show that that considerable eagle habitat has already been lost in Amazonia due to the expansion of the "Arc of Deforestation", and that Amazonian forests currently represent 93% of the current distribution of the species. We also show that the Serra do Mar protected areas in southeastern Brazil is the most promising region for Harpy Eagle reintroductions in the Atlantic Forest. Reintroduction and captive breeding programs have been undertaken for Harpy Eagles, building the technical and biological basis for a successful restoration framework. Our distribution range for this species represents a 41% reduction of what is currently proposed by IUCN. Furthermore, habitat loss in Amazonia, combined with industrial logging and hunting suggest that the conservation status of this species should be reassessed. We suggest researchers and conservation practitioners can use this work to help expand efforts to conserve Harpy Eagles and their natural habitats
Light and Motion in SDSS Stripe 82: The Catalogues
We present a new public archive of light-motion curves in Sloan Digital Sky
Survey (SDSS) Stripe 82, covering 99 deg in right ascension from RA = 20.7 h to
3.3 h and spanning 2.52 deg in declination from Dec = -1.26 to 1.26 deg, for a
total sky area of ~249 sq deg. Stripe 82 has been repeatedly monitored in the
u, g, r, i and z bands over a seven-year baseline. Objects are cross-matched
between runs, taking into account the effects of any proper motion. The
resulting catalogue contains almost 4 million light-motion curves of stellar
objects and galaxies. The photometry are recalibrated to correct for varying
photometric zeropoints, achieving ~20 mmag and ~30 mmag root-mean-square (RMS)
accuracy down to 18 mag in the g, r, i and z bands for point sources and
extended sources, respectively. The astrometry are recalibrated to correct for
inherent systematic errors in the SDSS astrometric solutions, achieving ~32 mas
and ~35 mas RMS accuracy down to 18 mag for point sources and extended sources,
respectively.
For each light-motion curve, 229 photometric and astrometric quantities are
derived and stored in a higher-level catalogue. On the photometric side, these
include mean exponential and PSF magnitudes along with uncertainties, RMS
scatter, chi^2 per degree of freedom, various magnitude distribution
percentiles, object type (stellar or galaxy), and eclipse, Stetson and Vidrih
variability indices. On the astrometric side, these quantities include mean
positions, proper motions as well as their uncertainties and chi^2 per degree
of freedom. The here presented light-motion curve catalogue is complete down to
r~21.5 and is at present the deepest large-area photometric and astrometric
variability catalogue available.Comment: MNRAS accepte
What's in a name?: a discussion paper on the labels and location of self-organising community groups, with particular reference to mental health and Black groups
This article discusses the labelling and location of self-organising community groups – ‘self-help’, ‘peer support’
and ‘service user’. It notes the increasingly close relationship between these groups and statutory authorities,
and how this relationship may put the benefits of the groups at risk. Historical, cultural and social factors are
discussed to help explain differences and separate developments within African, Caribbean and other Black
communities
Polar body array CGH for prediction of the status of the corresponding oocyte. Part I: clinical results
Several randomized controlled trials have not shown a benefit from preimplantation genetic screening (PGS) biopsy of cleavage-stage embryos and assessment of up to 10 chromosomes for aneuploidy. Therefore, a proof-of-principle study was planned to determine the reliability of alternative form of PGS, i.e. PGS by polar body (PB) biopsy, with whole genome amplification and microarray-based comparative genomic hybridization (array CGH) analysis. In two centres, all mature metaphase II oocytes from patients who consented to the study were fertilized by ICSI. The first and second PBs (PB1and PB2) were biopsied and analysed separately for chromosome copy number by array CGH. If either or both of the PBs were found to be aneuploid, the corresponding zygote was then also processed by array CGH for concordance analysis. Both PBs were biopsied from a total of 226 zygotes from 42 cycles (average 5.5 per cycle; range 1-15) in 41 couples with an average maternal age of 40.0 years. Of these, the ploidy status of the zygote could be predicted in 195 (86%): 55 were euploid (28%) and 140 were aneuploid (72%). With only one exception, there was at least one predicted aneuploid zygote in each cycle and in 19 out of 42 cycles (45%), all zygotes were predicted to be aneuploid. Fresh embryos were transferred in the remaining 23 cycles (55%), and one frozen transfer was done. Eight patients had a clinical pregnancy of which seven were evolutive (ongoing pregnancy rates: 17% per cycle and 30% per transfer). The ploidy status of 156 zygotes was successfully analysed by array CGH: 38 (24%) were euploid and 118 (76%) were aneuploid. In 138 cases complete information was available on both PBs and the corresponding zygotes. In 130 (94%), the ploidy status of the zygote was concordant with the ploidy status of the PBs and in 8 (6%), the results were discordant. This proof-of-principle study indicates that the ploidy of the zygote can be predicted with acceptable accuracy by array CGH analysis of both PB
New UltraCool and Halo White Dwarf Candidates in SDSS Stripe 82
A 2.5 x 100 degree region along the celestial equator (Stripe 82) has been
imaged repeatedly from 1998 to 2005 by the Sloan Digital Sky Survey. A new
catalogue of ~4 million light-motion curves, together with over 200 derived
statistical quantities, for objects in Stripe 82 brighter than r~21.5 has been
constructed by combining these data by Bramich et al. (2007). This catalogue is
at present the deepest catalogue of its kind. Extracting the ~130000 objects
with highest signal-to-noise ratio proper motions, we build a reduced proper
motion diagram to illustrate the scientific promise of the catalogue. In this
diagram disk and halo subdwarfs are well-separated from the cool white dwarf
sequence. Our sample of 1049 cool white dwarf candidates includes at least 8
and possibly 21 new ultracool H-rich white dwarfs (T_eff < 4000K) and one new
ultracool He-rich white dwarf candidate identified from their SDSS optical and
UKIDSS infrared photometry. At least 10 new halo white dwarfs are also
identified from their kinematics.Comment: 10 pages, 5 figures, published in MNRAS, minor text changes, final
versio
Conceptualisations of children’s wellbeing at school: the contribution of recognition theory
A large study in Australian schools aimed to elucidate understandings of ‘wellbeing’ and of factors in school life that contribute to it. Students and teachers understood wellbeing primarily, and holistically, in terms of interpersonal relationships, in contrast to policy documents which mainly focused on ‘problem areas’ such as mental health. The study also drew on recognition theory as developed by the social philosopher Axel Honneth. Results indicate that recognition theory may be useful in understanding wellbeing in schools, and that empirical research in schools may give rise to further questions regarding theory
‘Silence does not sound the same for everyone’: student teachers’ narratives:Student Teachers’ Narratives Around Behavior Management in Scottish Schools
- …