502 research outputs found
Literacy practices of primary education children in Andalusia (Spain): a family-based perspective
Primary school children develop literacy practices in various domains and situations in everyday life.
This study focused on the analysis of literacy practices of children aged 8â12 years from the perspec-
tive of their families. 1,843 families participated in the non-experimental explanatory study. The
children in these families speak Spanish as a first language and are schooled in this language. The
instrument used was a self-report questionnaire about childrenâs home-literacy practices. The data
obtained were analysed using categorical principal components analysis (CATPCA) and analysis of
variance (ANOVA). The results show the complex relationship between literacy practices developed
by children in the domains of home and school and the limited development of a literacy-promoting
âthird spaceâ. In conclusion, the families in our study had limited awareness of their role as literacy-
promoting agents and thought of literacy learning as restricted to formal or academic spaces
An X-ray and optical study of the cluster A33
We report the first detailed X-ray and optical observations of the
medium-distant cluster A33 obtained with the Beppo-SAX satellite and with the
UH 2.2m and Keck II telescopes at Mauna Kea. The information deduced from X-ray
and optical imaging and spectroscopic data allowed us to identify the X-ray
source 1SAXJ0027.2-1930 as the X-ray counterpart of the A33 cluster. The faint,
F_{2-10 keV} \approx 2.4 \times 10^{-13} \ergscm2, X-ray source
1SAXJ0027.2-1930, arcmin away from the optical position of the cluster
as given in the Abell catalogue, is identified with the central region of A33.
Based on six cluster galaxy redshifts, we determine the redshift of A33,
; this is lower than the value derived by Leir and Van Den Bergh
(1977). The source X-ray luminosity, L_{2-10 keV} = 7.7 \times 10^{43} \ergs,
and intracluster gas temperature, keV, make this cluster interesting
for cosmological studies of the cluster relation at intermediate
redshifts. Two other X-ray sources in the A33 field are identified. An AGN at
z0.2274, and an M-type star, whose emission are blended to form an extended
X-ray emission arcmin north of the A33 cluster. A third possibly
point-like X-ray source detected arcmin north-west of A33 lies close
to a spiral galaxy at z0.2863 and to an elliptical galaxy at the same
redshift as the cluster.Comment: 9 pages, 6 Figures, Latex (using psfig,l-aa), to appear in Astronomy
and Astrophysics S. (To get better quality copies of Figs.1-3 send an email
to: [email protected]). A&AS, in pres
Case 2--1994 management of a cardiac pheochromocytoma in two patients
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31664/1/0000599.pd
Catalog of Radio Galaxies with z>0.3. I:Construction of the Sample
The procedure of the construction of a sample of distant () radio
galaxies using NED, SDSS, and CATS databases for further application in
statistical tests is described. The sample is assumed to be cleaned from
objects with quasar properties. Primary statistical analysis of the list is
performed and the regression dependence of the spectral index on redshift is
found.Comment: 9 pages, 6 figures, 2 table
A Spitzer-Selected Galaxy Cluster at z=1.62
We report the discovery of a galaxy cluster at z=1.62 located in the Spitzer
Wide-Area Infrared Extragalactic survey XMM-LSS field. This structure was
selected solely as an overdensity of galaxies with red Spitzer/IRAC colors,
satisfying [3.6]-[4.5] > -0.1 AB mag. Photometric redshifts derived from Subaru
XMM Deep Survey (BViz-bands), UKIRT Infrared Deep Survey-Ultra-Deep Survey
(UKIDSS-UDS, JK-bands), and from the Spitzer Public UDS survey (3.6-8.0 micron)
show that this cluster corresponds to a surface density of galaxies at z ~ 1.6
that is more than 20 sigma above the mean at this redshift. We obtained optical
spectroscopic observations of galaxies in the cluster region using IMACS on the
Magellan telescope. We measured redshifts for seven galaxies in the range
z=1.62-1.63 within 2.8 arcmin (<1.4 Mpc) of the astrometric center of the
cluster. A posteriori analysis of the XMM data in this field reveal a weak (4
sigma) detection in the [0.5-2 keV] band compatible with the expected thermal
emission from such a cluster. The color-magnitude diagram of the galaxies in
this cluster shows a prominent red-sequence, dominated by a population of red
galaxies with (z-J) > 1.7 mag. The photometric redshift probability
distributions for the red galaxies are strongly peaked at z=1.62, coincident
with the spectroscopically confirmed galaxies. The rest-frame (U-B) color and
scatter of galaxies on the red-sequence are consistent with a mean
luminosity-weighted age of 1.2 +/- 0.1 Gyr, yielding a formation redshift z_f =
2.35 +/- 0.10, and corresponding to the last significant star-formation period
in these galaxies.Comment: ApJ, in press, 11 pages, 7 figures (some in color). Updated with the
slightly modified ApJ-accepted version
Scalar and vector Slepian functions, spherical signal estimation and spectral analysis
It is a well-known fact that mathematical functions that are timelimited (or
spacelimited) cannot be simultaneously bandlimited (in frequency). Yet the
finite precision of measurement and computation unavoidably bandlimits our
observation and modeling scientific data, and we often only have access to, or
are only interested in, a study area that is temporally or spatially bounded.
In the geosciences we may be interested in spectrally modeling a time series
defined only on a certain interval, or we may want to characterize a specific
geographical area observed using an effectively bandlimited measurement device.
It is clear that analyzing and representing scientific data of this kind will
be facilitated if a basis of functions can be found that are "spatiospectrally"
concentrated, i.e. "localized" in both domains at the same time. Here, we give
a theoretical overview of one particular approach to this "concentration"
problem, as originally proposed for time series by Slepian and coworkers, in
the 1960s. We show how this framework leads to practical algorithms and
statistically performant methods for the analysis of signals and their power
spectra in one and two dimensions, and, particularly for applications in the
geosciences, for scalar and vectorial signals defined on the surface of a unit
sphere.Comment: Submitted to the 2nd Edition of the Handbook of Geomathematics,
edited by Willi Freeden, Zuhair M. Nashed and Thomas Sonar, and to be
published by Springer Verlag. This is a slightly modified but expanded
version of the paper arxiv:0909.5368 that appeared in the 1st Edition of the
Handbook, when it was called: Slepian functions and their use in signal
estimation and spectral analysi
To what extent is behaviour a problem in English schools?:Exploring the scale and prevalence of deficits in classroom climate
The working atmosphere in the classroom is an important variable in the process of education in schools, with several studies suggesting that classroom climate is an important influence on pupil attainment. There are wide differences in the extent to which classroom climate is considered to be a problem in English schools. Some âofficialâ reports suggest that behaviour in schools is âsatisfactory or betterâ in the vast majority of schools; other sources have pointed to behaviour being a serious and widespread problem. The paper details four studies conducted over the past decade which aimed to explore these disparities. The aim of the research was to gain a more accurate insight into the extent to which deficits in classroom climate limit educational attainment and equality of educational opportunity in English schools. The findings question the suggestion that behaviour is satisfactory or better in 99.7% of English schools and the concluding section suggests ways in which deficits in classroom climate might be addressed. Although the study is limited to classrooms in England, OECD studies suggest that deficits in the working atmosphere in classrooms occur in many countries. The study therefore has potential relevance for education systems in other countries
A DNA-based method for studying root responses to drought in field-grown wheat genotypes
Root systems are critical for water and nutrient acquisition by crops. Current methods measuring root biomass and length are slow and labour-intensive for studying root responses to environmental stresses in the field. Here, we report the development of a method that measures changes in the root DNA concentration in soil and detects root responses to drought in controlled environment and field trials. To allow comparison of soil DNA concentrations from different wheat genotypes, we also developed a procedure for correcting genotypic differences in the copy number of the target DNA sequence. The new method eliminates the need for separation of roots from soil and permits large-scale phenotyping of root responses to drought or other environmental and disease stresses in the field.Chun Y. Huang, Haydn Kuchel, James Edwards, Sharla Hall, Boris Parent, Paul Eckermann, Herdina, Diana M. Hartley, Peter Langridge & Alan C. McKa
Compilation of a panel of informative single nucleotide polymorphisms for bovine identification in the Northern Irish cattle population
<p>Abstract</p> <p>Background</p> <p>Animal identification is pivotal in governmental agricultural policy, enabling the management of subsidy payments, movement of livestock, test scheduling and control of disease. Advances in bovine genomics have made it possible to utilise inherent genetic variability to uniquely identify individual animals by DNA profiling, much as has been achieved with humans over the past 20 years. A DNA profiling test based on bi-allelic single nucleotide polymorphism (SNP) markers would offer considerable advantages over current short tandem repeat (STR) based industry standard tests, in that it would be easier to analyse and interpret. In this study, a panel of 51 genome-wide SNPs were genotyped across panels of semen DNA from 6 common breeds for the purposes of ascertaining allelic frequency. For SNPs on the same chromosome, the extent of linkage disequilbrium was determined from genotype data by Expectation Maximization (EM) algorithm. Minimum probabilities of unique identification were determined for each breed panel. The usefulness of this SNP panel was ascertained by comparison to the current bovine STR Stockmarks II assay. A statistically representative random sampling of bovine animals from across Northern Ireland was assembled for the purposes of determining the population allele frequency for these STR loci and subsequently, the minimal probability of unique identification they conferred in sampled bovine animals from Northern Ireland.</p> <p>Results</p> <p>6 SNPs exhibiting a minor allele frequency of less than 0.2 in more than 3 of the breed panels were excluded. 2 Further SNPs were found to reside in coding areas of the cattle genome and were excluded from the final panel. The remaining 43 SNPs exhibited genotype frequencies which were in Hardy Weinberg Equilibrium. SNPs on the same chromosome were observed to have no significant linkage disequilibrium/allelic association. Minimal probabilities of uniquely identifying individual animals from each of the breeds were obtained and were observed to be superior to those conferred by the industry standard STR assay.</p> <p>Conclusions</p> <p>The 43 SNPs characterised herein may constitute a starting point for the development of a SNP based DNA identification test for European cattle.</p
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