8,946 research outputs found
Extended homozygosity is not usually due to cytogenetic abnormality
<p>Abstract</p> <p>Background</p> <p>Previous studies have reported frequent stretches of homozygosity in human subjects but have failed to clarify whether these are due to cytogenetic abnormalities or to autozygosity.</p> <p>Methods</p> <p>Trios which had been typed for closely spaced SNPs spanning the genome were studied. Stretches of extended homozygosity were identified in the child members, as were occasions on which the child had been genotyped as not inheriting one parental allele. The number of times such transmission errors occurred within regions of extended homozygosity was compared with the chance expectation.</p> <p>Results</p> <p>Transmission errors occurred more rarely in regions of extended homozygosity than would be expected by chance.</p> <p>Discussion</p> <p>Regions of extended homozygosity are not generally due to cytogenetic abnormalities such as uniparental isodisomy. They reflect the Mendelian inheritance of haplotypes from a common ancestor. This may have implications for mapping disease genes.</p
European cities in globalization: a comparative analysis based on the location strategies of advanced producer services
Today there is a key question that lurks behind any consideration of Europe and its cities: is this foundation core zone of the modern world-system showing symptoms of dropping out of the contemporary core zone? It certainly appears that in the period of crises since 2008, Europe has been falling behind other major world-regions. Dubbed the “austerity region” of the world, such an interpretation sees Europe as the first part of the world-economy core to be subject to what are effectively structural adjustment programmes, largely self-imposed but still resulting in a process of peripheralization. Although uneven in impact, this is clearly a result of Europe’s states failing to adequately manage and regulate the economic activities within their territories. However it is far too soon to say whether such a monumental global economic shift is happening but we can investigate the current unevenness of economic globalization amongst European states. We compare three of these states that represent different degrees of potential peripheralization: Spain showing the stronger symptoms, Germany with least symptoms, and Britain somewhere in between. Our study is based upon an original analysis of advanced producer services that combines comparisons between countries and relations between cities
HAT-P-13: a multi-site campaign to detect the transit of the second planet in the system
A possible transit of HAT-P-13c has been predicted to occur on 2010 April 28.
Here we report on the results of a multi-site campaign that has been organised
to detect the event. CCD photometric observations have been carried out at five
observatories in five countries. We reached 30% time coverage in a 5 days
interval centered on the suspected transit of HAT-P-13c. Two transits of
HAT-P-13b were also observed. No transit of HAT-P-13c has been detected while
the campaign was on. By a numerical experiment with 10^5 model systems we
conclude that HAT-P-13c is not a transiting exoplanet with a significance level
from 65% to 72%, depending on the planet parameters and the prior assumptions.
We present two times of transit of HAT-P-13b ocurring at BJD 2455141.5522 +-
0.0010 and BJD 2455249.4508 +- 0.0020. The TTV of HAT-P-13b is consistent with
zero within 0.001 days. The refined orbital period of HAT-P-13b is 2.916293 +-
0.000010 days.Comment: 5 pages, 4 figures, to be accepted by A&
A study on the inclusion of forest canopy morphology data in numerical simulations for the purpose of wind resource assessment
A series of numerical simulations of the flow over a forest stand have been conducted using two different turbulence closure models along with various levels of canopy morphology data. Simulations have been validated against Stereoscopic Particle Image Velocimetry measurements from a wind tunnel study using one hundred architectural model trees, the porosities of which have been assessed using a photographic technique.
It has been found that an accurate assessment of the porosity of the canopy, and specifically the variability with height, improves simulation quality regardless of the turbulence closure model used or the level of canopy geometry included. The observed flow field and recovery of the wake is in line with characteristic canopy flows published in the literature and it was found that the shear stress transport turbulence model was best able to capture this detail numerically
Effect of scandium triflate on the RAFT copolymerization of methyl acrylate and vinyl acetate controlled by an acid/base “switchable” chain transfer agent
Modulation of the activity of an acid/base switchable dithiocarbamate RAFT agent, cyanomethyl (4-fluorophenyl)(pyridin-4-yl)carbamodithioate, with the Lewis acid scandium triflate (Sc(OTf)3) was investigated to examine the ability to deliver improved control over RAFT copolymerizations involving both more-activated and less-activated monomers—specifically the copolymerization of methyl acrylate (MA) and vinyl acetate (VAc). The introduction of either 0.5 or 1 mol equiv of Sc(OTf)3, with respect to RAFT agent, into a RAFT copolymerization of MA and VAc provides substantially improved control resulting in significantly reduced molar mass dispersities (Đ) (∼1.1–1.3) than achieved in its absence (Đ ∼ 1.3–1.4). Furthermore, similar introduction of Sc(OTf)3 into MA homopolymerization mediated by the same RAFT agent also delivered polymers of very low Đ (∼1.15). Sc(OTf)3 was also found to lower the rate of polymerization and alter the copolymerization reactivity ratios for MA and VAc. Increasing the Lewis acid concentration provides enhanced incorporation of the less active monomer, VAc, into the copolymers ([Sc(OTf)3]/[RAFT] = 0, rMA = 4.04, rVAc = 0.032; [Sc(OTf)3]/[RAFT] = 0.5, rMA = 3.08, rVAc = 0.17; [Sc(OTf)3]/[RAFT] = 1, rMA = 2.68, rVAc = 0.62). Carbon nuclear magnetic resonance (13C NMR) and differential scanning calorimetry (DSC) analysis of preparative samples confirm the enhanced VAc incorporation with increased levels of Sc(OTf)3. Importantly the inclusion of Sc(OTf)3 does not deleteriously affect the thiocarbonylthio end-groups of the RAFT polymers, with high end-group fidelity being observed in all copolymerizations
Triplet Dimerization Crossover Driven by Magnetic Frustration in In2VO5
In2VO5, containing magnetically frustrated zig-zag chains, shows a remarkable
magnetic crossover at 120 K between paramagnetic states with positive (17 K)
and negative (-70 K) Weiss temperatures. Magnetic moment and entropy data show
that the V4+ S = 1/2 spins condense into S = 1 triplet dimers below the
crossover. A further freezing of the antiferromagnetically coupled triplet
dimers into a global singlet state is observed at 2.5 K, with no long range
magnetic order down to 0.42 K and in fields up to 9 T. No structural V-V
dimerization is observed by high-resolution X-ray diffraction down to 10 K, but
a subtle lattice anomaly evidences a spin-lattice coupling in the triplet dimer
state. This is assigned to longitudinal oxygen displacement modes that reduce
frustration within the chains and so couple to the spin dimer fluctuations.Comment: submitted for publicatio
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Intraseasonal variability of air-sea fluxes over the Bay of Bengal during the southwest monsoon
In the Bay of Bengal (BoB), surface heat fluxes play a key role in monsoon dynamics and prediction. The accurate representation of large-scale surface fluxes is dependent on the quality of gridded reanalysis products. Meteorological and surface flux variables from five reanalysis products are compared and evaluated against in situ data from the RAMA moored array in the BoB. The reanalysis products: ERA-Interim (ERA-I), TropFlux, MERRA-2, JRA-55 and CFSR are assessed for their characterisation of air-sea fluxes during the southwest monsoon season (JJAS). ERA-I captured radiative fluxes best while TropFlux captured turbulent and net heat fluxes (Qnet) best, and both products outperformed JRA-55, MERRA-2 and CFSR, showing highest correlations and smallest biases when compared to the in situ data. In all five products, the largest errors were in shortwave radiation (QSW) and latent heat flux (QLH), with non-negligible biases up to ∼75 W m−2. The QSW and QLH are the largest drivers of the observed Qnet variability, thus highlighting the importance of the results from the buoy comparison. There are also spatially coherent differences in the mean basin-wide fields of surface flux variables from the reanalysis products, indicating that the biases at the buoy position are not localized. Biases of this magnitude have severe implications on reanalysis products ability to capture the variability of monsoon processes. Hence, the representation of intraseasonal variability was investigated through the boreal summer intraseasonal oscillation and we found that TropFlux and ERA-I perform best at capturing intraseasonal climate variability during the southwest monsoon season
Uso de dispositivos fitness por parte de usuarios de gimnasios
El objetivo del presente estudio fue analizar los hábitos y nivel de uso de tecnologías aplicadas al deporte por parte de usuarios de centros de fitness. La muestra fue de 126 usuarios de centros fitness (61, 9% hombres y 38, 1% mujeres) de la ciudad de Zaragoza. El 66% de los sujetos realizaban un mínimo de 4 días semanales de actividad física y más del 30% realizaba 3 días de ejercicio físico semanal en el centro de fitness. Se observó que casi un 70% de los usuarios utilizan tecnología para realizar sus entrenamientos. Cabe destacar que las disciplinas deportivas en las que más uso se hizo de dispositivos tecnológicos fueron el running y el ciclo indoor (como actividad dirigida). Con respecto a los principales motivos que tienen los usuarios para utilizar tecnología durante su entrenamiento, destacan el de controlar la intensidad del mismo y el de mejorar su salud. Por el contrario, se observó que las personas que no usan dispositivos para realizar ejercicio físico afirman que éstos no responden a sus necesidades o no tienen suficientes conocimientos para saber utilizarlos. Dicho esto, resaltar que la mayoría de los sujetos del estudio afirmaron que la tecnología que se usaba, por muy avanzada o práctica que fuese, no podía sustituir a los profesionales de la ciencia de la actividad física y el deporte.
The aim of the present study was to analyze sports habits and use of technology applied to sport by fitness center users. The sample was composed by 126 fitness center users (61, 9% men and 38, 1% women) belonging to private mid-market fitness centers of Zaragoza. A total of 66% of the subjects trained at least four days per week, while more than 30% carried out three days of physical exercise per week in a fitness center. We observed that around 70% of the sample used technology to carry out their training. It should be pointed out that the sports disciplines with the highest use of devices were running and spinning (directed activity). Regarding the main reasons for using technology during training, control of training intensity and improving health were the most common. On the contrary, we noticed that those persons who did not use gadgets during the practice of physical exercise stated that such devices were not useful or that they did not have enough knowledge to use them correctly. With this in mind, it is necessary to emphasize that the majority of the subjects from the present study affirmed that technology cannot replace sports and physical activity sciences professionals
Galaxy And Mass Assembly (GAMA) : refining the local galaxy merger rate using morphological information
KRVS acknowledges the Science and Technology Facilities Council (STFC) for providing funding for this project, as well as the Government of Catalonia for a research travel grant (ref. 2010 BE-00268) to begin this project at the University of Nottingham. PN acknowledges the support of the Royal Society through the award of a University Research Fellowship and the European Research Council, through receipt of a Starting Grant (DEGAS-259586).We use the Galaxy And Mass Assembly (GAMA) survey to measure the local Universe mass-dependent merger fraction and merger rate using galaxy pairs and the CAS (concentration, asymmetry, and smoothness) structural method, which identifies highly asymmetric merger candidate galaxies. Our goals are to determine which types of mergers produce highly asymmetrical galaxies and to provide a new measurement of the local galaxy major merger rate. We examine galaxy pairs at stellar mass limits down to M* = 108 M⊙ with mass ratios of 4:1) the lower mass companion becomes highly asymmetric, whereas the larger galaxy is much less affected. The fraction of highly asymmetric paired galaxies which have a major merger companion is highest for the most massive galaxies and drops progressively with decreasing mass. We calculate that the mass-dependent major merger fraction is fairly constant at ∼1.3–2 per cent within 109.5 < M* < 1011.5 M⊙, and increases to ∼4 per cent at lower masses. When the observability time-scales are taken into consideration, the major merger rate is found to approximately triple over the mass range we consider. The total comoving volume major merger rate over the range 108.0 < M* < 1011.5 M⊙ is (1.2 ± 0.5) × 10−3 h370 Mpc−3 Gyr−1.Publisher PDFPeer reviewe
Copy number variation in Parkinson's disease
A central theme of human genetic studies is to understand genomic variation and how this underlies the inherited basis of disease. Genomic variation can provide increased biological understanding of disease processes, which is necessary to develop future treatments. Recent technological advances have highlighted the role of copy number variants in normal and pathological phenotypic expression. These applications have been used in studies of Parkinson's disease, a common, late-onset, progressive neurodegenerative disorder. At present the main therapeutic approach is administration of symptom-alleviating drugs, which neither reverses the disease process nor halts its progression. However, the generation of in vivo model systems and development of novel disease intervention strategies for Parkinson's disease have come from research on monogenic forms of the disorder, including those caused by copy number variants. Here, we review the role of copy number variants and the mechanistic insights they have provided on the pathogenesis of Parkinson's disease
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