1,301 research outputs found
Prevalence of generalised joint hypermobility in school-aged children from east-central European region
Background: There is no literature regarding joint mobility in children of the Central and Eastern Europe. Studies describing clinical characteristics and functional outcomes are still needed. The aim of this study was to assess the prevalence of generalised joint hypermobility (GJH) in the group of school-aged children from Vilnius, the capital city of Lithuania, in relation to different cut-off values of the Beighton score (BS), and to identify possible patients with joint hypermobility syndrome.
Materials and methods: The representative sample of this study was calculated to be 760 subjects. A total of 778 children from different schools were screened for the mobility of joints. The medical examination included an assessment of joints’ hypermobility according to the BS. The presence of specific signs (marfanoid habitus, antimongoloid slant and drooping eyelids) was assessed additionally. Parents of all involved children were asked to answer the questions developed based on the Brighton criteria regarding the medical history of children.
Results: The prevalence of GJH in school-aged children from Vilnius, depending on the BS cut-off value, was 19.2% (BS ≥ 4), 9.5% (BS ≥ 5) or 5.7% (BS ≥ 6). The increased range of mobility was most frequently detected in thumbs of school- -aged children. The frequency of hyperextension > 10o in knees was 7- to 8-fold lower than the frequency of hyperextension > 10o in a passive opposition of the thumb. The evaluation results were similar on the left and right sides in 87.4% cases of thumb opposition, 90.1% cases of hyperextension of 5th finger, 87.9% cases of elbow manoeuvres, and 94.8% attempts to hyperextend knee.
Conclusions: The prevalence of GJH in school-aged children from Vilnius depends on the BS cut-off value and ranges from 5.7% to 19.2%.
First principles calculation of structural and magnetic properties for Fe monolayers and bilayers on W(110)
Structure optimizations were performed for 1 and 2 monolayers (ML) of Fe on a
5 ML W(110) substrate employing the all-electron full-potential linearized
augmented plane-wave (FP-LAPW) method. The magnetic moments were also obtained
for the converged and optimized structures. We find significant contractions
( 10 %) for both the Fe-W and the neighboring Fe-Fe interlayer spacings
compared to the corresponding bulk W-W and Fe-Fe interlayer spacings. Compared
to the Fe bcc bulk moment of 2.2 , the magnetic moment for the surface
layer of Fe is enhanced (i) by 15% to 2.54 for 1 ML Fe/5 ML W(110), and
(ii) by 29% to 2.84 for 2 ML Fe/5 ML W(110). The inner Fe layer for 2
ML Fe/5 ML W(110) has a bulk-like moment of 2.3 . These results agree
well with previous experimental data
Comparative risk assessment of carcinogens in alcoholic beverages using the margin of exposure approach
Alcoholic beverages have been classified as carcinogenic to humans. As alcoholic beverages are multicomponent mixtures containing several carcinogenic compounds, a quantitative approach is necessary to compare the risks. Fifteen known and suspected human carcinogens (acetaldehyde, acrylamide, aflatoxins, arsenic, benzene, cadmium, ethanol, ethyl carbamate, formaldehyde, furan, lead, 4-methylimidazole, N-nitrosodimethylamine, ochratoxin A and safrole) occurring in alcoholic beverages were identified based on monograph reviews by the International Agency for Research on Cancer. The margin of exposure (MOE) approach was used for comparative risk assessment. MOE compares a toxicological threshold with the exposure. MOEs above 10,000 are judged as low priority for risk management action. MOEs were calculated for different drinking scenarios (low risk and heavy drinking) and different levels of contamination for four beverage groups (beer, wine, spirits and unrecorded alcohol). The lowest MOEs were found for ethanol (3.1 for low risk and 0.8 for heavy drinking). Inorganic lead and arsenic have average MOEs between 10 and 300, followed by acetaldehyde, cadmium and ethyl carbamate between 1,000 and 10,000. All other compounds had average MOEs above 10,000 independent of beverage type. Ethanol was identified as the most important carcinogen in alcoholic beverages, with clear dose response. Some other compounds (lead, arsenic, ethyl carbamate, acetaldehyde) may pose risks below thresholds normally tolerated for food contaminants, but from a cost-effectiveness point of view, the focus should be on reducing alcohol consumption in general rather than on mitigative measures for some contaminants that contribute only to a limited extent (if at all) to the total health risk
Strain Relief in Cu-Pd Heteroepitaxy
We present experimental and theoretical studies of Pd/Cu(100) and Cu/Pd(100) heterostructures in order to explore their structure and misfit strain relaxation. Ultrathin Pd and Cu films are grown by pulsed laser deposition at room temperature. For Pd/Cu, compressive strain is released by networks of misfit dislocations running in the [100] and [010] directions, which appear after a few monolayers (ML) already. In striking contrast, for Cu/Pd the tensile overlayer remains coherent up to about 9 ML, after which multilayer growth occurs. The strong asymmetry between tensile and compressive cases is in contradiction with continuum elasticity theory and is also evident in the structural parameters of the strained films. Molecular dynamics calculations based on classical many-body potentials confirm the pronounced tensile-compressive asymmetry and are in good agreement with the experimental data.Peer reviewe
Genome-Wide Analysis of Interchromosomal Interaction Probabilities Reveals Chained Translocations and Overrepresentation of Translocation Breakpoints in Genes in a Cutaneous T-Cell Lymphoma Cell Line
In classical models of tumorigenesis, the accumulation of tumor promoting chromosomal aberrations is described as a gradual process. Next-generation sequencing-based methods have recently revealed complex patterns of chromosomal aberrations, which are beyond explanation by these classical models of karyotypic evolution of tumor genomes. Thus, the term chromothripsis has been introduced to describe a phenomenon, where temporarily and spatially confined genomic instability results in dramatic chromosomal rearrangements limited to segments of one or a few chromosomes. Simultaneously arising and misrepaired DNA double-strand breaks are also the cause of another phenomenon called chromoplexy, which is characterized by the presence of chained translocations and interlinking deletion bridges involving several chromosomes. In this study, we demonstrate the genome-wide identification of chromosomal translocations based on the analysis of translocation-associated changes in spatial proximities of chromosome territories on the example of the cutaneous T-cell lymphoma cell line Se-Ax. We have used alterations of intra- and interchromosomal interaction probabilities as detected by genome-wide chromosome conformation capture (Hi-C) to infer the presence of translocations and to fine-map their breakpoints. The outcome of this analysis was subsequently compared to datasets on DNA copy number alterations and gene expression. The presence of chained translocations within the Se-Ax genome, partly connected by intervening deletion bridges, indicates a role of chromoplexy in the etiology of this cutaneous T-cell lymphoma. Notably, translocation breakpoints were significantly overrepresented in genes, which highlight gene-associated biological processes like transcription or other gene characteristics as a possible cause of the observed complex rearrangements. Given the relevance of chromosomal aberrations for basic and translational research, genome-wide high-resolution analysis of structural chromosomal aberrations will gain increasing importance
The Palomar Testbed Interferometer Calibrator Catalog
The Palomar Testbed Interferometer (PTI) archive of observations between 1998
and 2005 is examined for objects appropriate for calibration of optical
long-baseline interferometer observations - stars that are predictably
point-like and single. Approximately 1,400 nights of data on 1,800 objects were
examined for this investigation. We compare those observations to an
intensively studied object that is a suitable calibrator, HD217014, and
statistically compare each candidate calibrator to that object by computing
both a Mahalanobis distance and a Principal Component Analysis. Our hypothesis
is that the frequency distribution of visibility data associated with
calibrator stars differs from non-calibrator stars such as binary stars.
Spectroscopic binaries resolved by PTI, objects known to be unsuitable for
calibrator use, are similarly tested to establish detection limits of this
approach. From this investigation, we find more than 350 observed stars
suitable for use as calibrators (with an additional being
rejected), corresponding to sky coverage for PTI. This approach
is noteworthy in that it rigorously establishes calibration sources through a
traceable, empirical methodology, leveraging the predictions of spectral energy
distribution modeling but also verifying it with the rich body of PTI's on-sky
observations.Comment: 100 pages, 7 figures, 7 tables; to appear in the May 2008ApJS, v176n
The AMANDA Neutrino Telescope
With an effective telescope area of order m for TeV neutrinos, a
threshold near 50 GeV and a pointing accuracy of 2.5 degrees per muon
track, the AMANDA detector represents the first of a new generation of high
energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We
describe early results on the calibration of natural deep ice as a particle
detector as well as on AMANDA's performance as a neutrino telescope.Comment: 12 pages, Latex2.09, uses espcrc2.sty and epsf.sty, 13 postscript
files included. Talk presented at the 18th International Conference on
Neutrino Physics and Astrophysics (Neutrino 98), Takayama, Japan, June 199
Search for Point Sources of High Energy Neutrinos with AMANDA
This paper describes the search for astronomical sources of high-energy
neutrinos using the AMANDA-B10 detector, an array of 302 photomultiplier tubes,
used for the detection of Cherenkov light from upward traveling
neutrino-induced muons, buried deep in ice at the South Pole. The absolute
pointing accuracy and angular resolution were studied by using coincident
events between the AMANDA detector and two independent telescopes on the
surface, the GASP air Cherenkov telescope and the SPASE extensive air shower
array. Using data collected from April to October of 1997 (130.1 days of
livetime), a general survey of the northern hemisphere revealed no
statistically significant excess of events from any direction. The sensitivity
for a flux of muon neutrinos is based on the effective detection area for
through-going muons. Averaged over the Northern sky, the effective detection
area exceeds 10,000 m^2 for E_{mu} ~ 10 TeV. Neutrinos generated in the
atmosphere by cosmic ray interactions were used to verify the predicted
performance of the detector. For a source with a differential energy spectrum
proportional to E_{nu}^{-2} and declination larger than +40 degrees, we obtain
E^2(dN_{nu}/dE) <= 10^{-6}GeVcm^{-2}s^{-1} for an energy threshold of 10 GeV.Comment: 46 pages, 22 figures, 4 tables, submitted to Ap.
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