724 research outputs found
P05-09. 4e10 epitope-scaffolds mimic the antibody-bound epitope conformation and block neutralization by sera from rare HIV+ individuals
Spectroscopic variability of two Oe stars
The Oe stars HD45314 and HD60848 have recently been found to exhibit very
different X-ray properties: whilst HD60848 has an X-ray spectrum and emission
level typical of most OB stars, HD45314 features a much harder and brighter
X-ray emission, making it a so-called gamma Cas analogue. Monitoring the
optical spectra could provide hints towards the origin of these very different
behaviours. We analyse a large set of spectroscopic observations of HD45314 and
HD60848, extending over 20 years. We further attempt to fit the H-alpha line
profiles of both stars with a simple model of emission line formation in a
Keplerian disk. Strong variations in the strengths of the H-alpha, H-beta, and
He I 5876 emission lines are observed for both stars. In the case of HD60848,
we find a time lag between the variations in the equivalent widths of these
lines. The emission lines are double peaked with nearly identical strengths of
the violet and red peaks. The H-alpha profile of this star can be successfully
reproduced by our model of a disk seen under an inclination of 30 degrees. In
the case of HD45314, the emission lines are highly asymmetric and display
strong line profile variations. We find a major change in behaviour between the
2002 outburst and the one observed in 2013. This concerns both the relationship
between the equivalent widths of the various lines and their morphologies at
maximum strength (double-peaked in 2002 versus single-peaked in 2013). Our
simple disk model fails to reproduce the observed H-alpha line profiles of
HD45314. Our results further support the interpretation that Oe stars do have
decretion disks similar to those of Be stars. Whilst the emission lines of
HD60848 are explained by a disk with a Keplerian velocity field, the disk of
HD45314 seems to have a significantly more complex velocity field that could be
related to the phenomenon that produces its peculiar X-ray emission.Comment: Accepted for Publication in A&
RosettaRemodel: A Generalized Framework for Flexible Backbone Protein Design
We describe RosettaRemodel, a generalized framework for flexible protein design that provides a versatile and convenient interface to the Rosetta modeling suite. RosettaRemodel employs a unified interface, called a blueprint, which allows detailed control over many aspects of flexible backbone protein design calculations. RosettaRemodel allows the construction and elaboration of customized protocols for a wide range of design problems ranging from loop insertion and deletion, disulfide engineering, domain assembly, loop remodeling, motif grafting, symmetrical units, to de novo structure modeling
A transient liquid-like phase in the displacement cascades of zircon, hafnon and thorite
The study of radiation effects in solids is important for the development of 'radiation-resistant' materials for fission-reactor applications'. The effects of heavy-ion irradiation in the isostructural orthosilicates zircon (ZrSiO4), hafnon (HfSiO4) and thorite (ThSiO4) are particularly important because these minerals are under active investigation for use as a waste form for plutonium-239 resulting from the dismantling of nuclear weapons(2-4). During ion irradiation, localized 'cascades' of displaced atoms can form as a result of ballistic collisions in the target material, and the temperature inside these regions may for a short time exceed the bulk melting temperature. Whether these cascades do indeed generate a localized liquid state(5-8) has, however, remained unclear. Here we investigate the irradiation-induced decomposition of zircon and hafnon, and find evidence for formation of a liquidlike state in the displacement cascades. Our results explain the frequent occurrence of ZrO2 in natural amorphous zircong(9-12) Moreover, we conclude that zircon-based nuclear waste forms should be maintained within strict temperature Limits, to avoid potentially detrimental irradiation-induced amorphization or phase decomposition of the zircon.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62853/1/395056a0.pd
What influences national and foreign physiciansâ geographic distribution? An analysis of medical doctorsâ residence location in Portugal
Background
The debate over physiciansâ geographical distribution has attracted the attention of the
economic and public health literature over the last forty years. Nonetheless, it is still to date
unclear what influences physiciansâ location, and whether foreign physicians contribute to fill
the geographical gaps left by national doctors in any given country. The present research sets
out to investigate the current distribution of national and international physicians in Portugal, with the objective to understand its determinants and provide an evidence base for policymakers to identify policies to influence it.
Methods
A cross-sectional study of physicians currently registered in Portugal was conducted to describe the population and explore the association of physician residence patterns with relevant personal and municipality characteristics. Data from the Portuguese Medical Council
on physiciansâ residence and characteristics were analysed, as well as data from the National Institute of Statistics on municipalitiesâ population, living standards and health care network.
Descriptive statistics, chi-square tests, negative binomial and logistic regression modelling were applied to determine: (a) municipality characteristics predicting Portuguese and International physiciansâ geographical distribution, and; (b) doctorsâ characteristics that could
increase the odds of residing outside the countryâs metropolitan areas.
Results
There were 39,473 physicians in Portugal in 2008, 51.1% of whom male, and 40.2% between
41 and 55 years of age. They were predominantly Portuguese (90.5%), with Spanish,
Brazilian and African nationalities also represented. Population, Populationâs Purchasing
Power, Nurses per capita and Municipality Development Index (MDI) were the municipality
characteristics displaying the strongest association with national physiciansâ location. For
foreign physicians, the MDI was not statistically significant, while municipalitiesâ foreign
population applying for residence appeared to be an additional positive factor in their location
decisions. In general, being foreigner and male resulted to be the physician characteristics
increasing the odds of residing outside the metropolitan areas. However, among the
internationals, older doctors were more likely to reside outside metropolitan areas. Being
Spanish or Brazilian (but not of African origin) was found to increase the odds of being based
outside the Lisbon and Oporto metropolitan areas.
Conclusions
The present study showed the relevance of studying one countryâs physician population to
understand the factors driving national and international doctorsâ location decisions. A more
nuanced understanding of national and foreign doctorsâ location appears to be needed to
design more effective policies to reduce the imbalance of medical services across
geographical areas.The study was supported by a research grant from the Portuguese High Commission for Health to the International Health Department of the Institute of Hygiene and Tropical.
Medicine
Both SEPT2 and MLL are down-regulated in MLL-SEPT2 therapy-related myeloid neoplasia
<p>Abstract</p> <p>Background</p> <p>A relevant role of septins in leukemogenesis has been uncovered by their involvement as fusion partners in <it>MLL</it>-related leukemia. Recently, we have established the <it>MLL-SEPT2 </it>gene fusion as the molecular abnormality subjacent to the translocation t(2;11)(q37;q23) in therapy-related acute myeloid leukemia. In this work we quantified <it>MLL </it>and <it>SEPT2 </it>gene expression in 58 acute myeloid leukemia patients selected to represent the major AML genetic subgroups, as well as in all three cases of <it>MLL-SEPT2</it>-associated myeloid neoplasms so far described in the literature.</p> <p>Methods</p> <p>Cytogenetics, fluorescence in situ hybridization (FISH) and molecular studies (RT-PCR, qRT-PCR and qMSP) were used to characterize 58 acute myeloid leukemia patients (AML) at diagnosis selected to represent the major AML genetic subgroups: <it>CBFB-MYH11 </it>(n = 13), <it>PML-RARA </it>(n = 12); <it>RUNX1-RUNX1T1 </it>(n = 12), normal karyotype (n = 11), and <it>MLL </it>gene fusions other than <it>MLL-SEPT2 </it>(n = 10). We also studied all three <it>MLL-SEPT2 </it>myeloid neoplasia cases reported in the literature, namely two AML patients and a t-MDS patient.</p> <p>Results</p> <p>When compared with normal controls, we found a 12.8-fold reduction of wild-type <it>SEPT2 </it>and <it>MLL-SEPT2 </it>combined expression in cases with the <it>MLL-SEPT2 </it>gene fusion (p = 0.007), which is accompanied by a 12.4-fold down-regulation of wild-type <it>MLL </it>and <it>MLL-SEPT2 </it>combined expression (p = 0.028). The down-regulation of <it>SEPT2 </it>in <it>MLL-SEPT2 </it>myeloid neoplasias was statistically significant when compared with all other leukemia genetic subgroups (including those with other <it>MLL </it>gene fusions). In addition, <it>MLL </it>expression was also down-regulated in the group of <it>MLL </it>fusions other than <it>MLL-SEPT2</it>, when compared with the normal control group (p = 0.023)</p> <p>Conclusion</p> <p>We found a significant down-regulation of both <it>SEPT2 </it>and <it>MLL </it>in <it>MLL-SEPT2 </it>myeloid neoplasias. In addition, we also found that <it>MLL </it>is under-expressed in AML patients with <it>MLL </it>fusions other than <it>MLL-SEPT2</it>.</p
Variability monitoring of OB stars during the Mons campaign
We present preliminary results of a 3-month campaign carried out in the
framework of the Mons project, where time-resolved Halpha observations are used
to study the wind and circumstellar properties of a number of OB stars.Comment: 2 pages, 1 figure. To appear in proceedings of IAUS272 'Active OB
Stars: Structure, Evolution, Mass Loss and Critical Limits
Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV
The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of âs = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pTâ„20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60â€pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2â€{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at âs = 7 TeV with the ATLAS detector
This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of âs = 7 TeV;{\rm Te}{\rm V}4.6\;{\rm f}{{{\rm b}}^{-1}}{{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}|\eta |\lt 1.9{{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques
- âŠ