1,260 research outputs found
DNA content of a functioning chicken kinetochore
© The Author(s) 2014. In order to understand the three-dimensional structure of the functional kinetochore in vertebrates, we require a complete list and stoichiometry for the protein components of the kinetochore, which can be provided by genetic and proteomic experiments. We also need to know how the chromatin-containing CENP-A, which makes up the structural foundation for the kinetochore, is folded, and how much of that DNA is involved in assembling the kinetochore. In this MS, we demonstrate that functioning metaphase kinetochores in chicken DT40 cells contain roughly 50 kb of DNA, an amount that corresponds extremely closely to the length of chromosomal DNA associated with CENP-A in ChIP-seq experiments. Thus, during kinetochore assembly, CENP-A chromatin is compacted into the inner kinetochore plate without including significant amounts of flanking pericentromeric heterochromatin. © 2014 The Author(s).Wellcome Trust [grant number 073915]; Wellcome Trust Centre for Cell Biology (core grant numbers 077707 and 092076); Darwin Trust of Edinburg
The morphologies and masses of extremely red galaxies in the Groth Strip survey
We present a new cataloge of EROs from the Groth strip and study the relation
between their morphology and mass. We find 102 EROs (F814W-K=>4, K<=21.0), over
a survey area of 155 arcmin^2. The photometric data include U,B,F606W,F814W,J,K
bands. Morphologies are based on a by eye classification and we distinguish
between 3 basic classes: compact objects, targets with a disc and/or a bulge
component and irregular or merger candidates. The majority of our targets has
either a very compact morphology (33+-6%), or show more or less distinct disc
components (41+-6%). 14+-4% are merger or irregulars and 7 objects could not be
classified. We also study the dependence of structural parameters on
morphological appearance. EROs that are either compact or show a distinct bulge
component have smaller median effective radii (1.22+-0.14 kpc and 3.31+-0.53
kpc) than disc dominated (5.50+-0.51 kpc) or possible irregular galaxies or
merger candidates (4.92+-0.14 kpc). The Sersic index changes from 2.30+-0.34
and 3.24+-0.55, to 1.03+-0.24 and 1.54+-0.40 respectively.
Most the EROs in our sample have redshifts between z=1 and z=2; however,
compact EROs in our sample are found at redshifts as low as z=0.4 and as high
as z=2.8; the latter qualify as well as DRGs. Disc-like EROs are also found up
to z=2.8; however those with a bulge-disc structure are only seen at z<1.5. For
each of these EROs we determined the stellar mass and mean population age by
fitting synthetic Bruzual (2007) spectra to the SED. Mass estimates were
obtained by assuming an exponentially declining star formation rate. Total
stellar masses are in the range 9.1<log(M/M_sun)<11.6. We cannot detect
significant differences between the stellar mass distribution of the
morphological classes. EROs with masses of log(M/M_sun)>11.0 dominantly show
compact morphologies, but also include a significant number of sources with a
disc morphology.Comment: 21 pages, 17 figures, accepted for publication in MNRA
Fatores de risco para quedas em pacientes adultos hospitalizados: um estudo caso-controle
Objective: to identify risk factors for falls in hospitalized adult patients. Methods: a matched case-control study (one control for each case). A quantitative study conducted in clinical and surgical units of a teaching hospital in Southern Brazil. The sample comprised 358 patients. Data were collected over 18 months between 2013-2014. Data analysis was performed with descriptive statistics and conditional logistic regression using Microsoft Excel and SPSS version 18.0. Results: risk factors identified were: disorientation/confusion [OR 4.25 (1.99 to 9.08), p<0.001]; frequent urination [OR 4.50 (1.86 to 10.87), p=0.001]; walking limitation [OR 4.34 (2.05 to 9.14), p<0.001]; absence of caregiver [OR 0.37 (0.22 to 0.63), p<0.001]; postoperative period [OR 0.50 (0.26 to 0.94), p=0.03]; and number of medications administered within 72 hours prior the fall [OR 1.20 (1.04 to 1.39) p=0.01]. Conclusion: risk for falls is multifactorial. However, understanding these factors provides support to clinical decision-making and positively influences patient safety.Objetivo: identificar los factores de riesgo para la ocurrencia de caĂdas en pacientes adultos hospitalizados. MĂ©todos: un estudio caso-control emparejado (un control para cada caso). InvestigaciĂłn cuantitativa llevada a cabo en unidades clĂnicas y quirĂșrgicas de un hospital universitario en el Sur de Brasil. La muestra constĂł de 358 pacientes. Se recopilaron datos durante 18 meses, entre 2013-2014. El anĂĄlisis de los datos se realizĂł mediante estadĂstica descriptiva y regresiĂłn logĂstica condicional, utilizando el Microsoft Excel y el SPSS versiĂłn 18.0. Resultados: los factores de riesgo identificados fueron: desorientaciĂłn/confusiĂłn [OR 4,25 (1,99 a 9,08), p<0,001]; micciĂłn frecuente [OR 4,50 (1,86 a 10,87), p=0,001]; limitaciĂłn para caminar [OR 4,34 (2,05 a 9,14), p<0,001]; ausencia de cuidadores [OR 0,37 (0,22 a 0,63), p<0,001]; perĂodo postoperatorio [OR 0,50 (0,26 a 0,94), p=0,03]; y nĂșmero de medicamentos administrados dentro de las 72 horas previas a la caĂda [OR 1,20 (1,04 a 1,39) p=0,01]. ConclusiĂłn: los riesgos de caĂdas son multifactoriales. Sin embargo, la comprensiĂłn de estos factores respalda la toma de decisiones clĂnicas y tiene un impacto positivo en la seguridad del paciente.Objetivo: identificar os fatores de risco para a ocorrĂȘncia de quedas em pacientes adultos hospitalizados. MĂ©todos: estudo do tipo caso-controle pareado (um controle para cada caso). Pesquisa quantitativa realizada em unidades clĂnicas e cirĂșrgicas de um hospital universitĂĄrio da regiĂŁo Sul do Brasil. A amostra incluiu 358 pacientes. Os dados foram coletados durante 18 meses, entre 2013-2014. A anĂĄlise dos dados foi realizada por meio de estatĂstica descritiva e regressĂŁo logĂstica condicional, utilizando o Microsoft Excel e o SPSS versĂŁo 18.0. Resultados: os fatores de risco identificados foram: desorientação/confusĂŁo [OR 4,25 (1,99 a 9,08), p<0,001]; micção frequente [OR 4,50 (1,86 a 10,87), p=0,001]; limitação para caminhar [OR 4,34 (2,05 a 9,14), p<0,001]; ausĂȘncia de cuidador [OR 0,37 (0,22 a 0,63), p<0,001]; perĂodo pĂłs-operatĂłrio [OR 0,50 (0,26 a 0,94), p=0,03]; e o nĂșmero de medicamentos administrados nas 72 horas anteriores Ă queda [OR 1,20 (1,04 a 1,39) p=0,01]. ConclusĂŁo: os riscos para quedas sĂŁo multifatoriais. Todavia, conhecĂȘ-los dĂĄ suporte Ă decisĂŁo clĂnica do enfermeiro, o que contribui para a busca das melhores intervençÔes preventivas e impacta positivamente na segurança dos pacientes
Synthesis and characterization of polystyrene-blockpoly(vinylbenzoic acid): a promising compound for manipulating photoresponsive properties at the nanoscale
"Published online: 27 January 2015"Using reversible addition-fragmentation chain
transfer (RAFT) polymerization, the effect of PSt macroRAFT
and 4VBA ratio on the synthesis of a carboxylic
acid functional block copolymer (PSt-b-P4VBA) was
studied. PSt macroRAFT polymer was initially prepared
followed by the insertion of 4-vinylbenzoic acid (4VBA)
monomer. The chemical structure of the diblock copolymer
was confirmed by NMR and FTIR. The effect of PSt
macroRAFT and 4VBA ratio on copolymerization yield
and on molecular weight distribution was assessed by gel
permeation chromatography. The rate of polymerization
did not change as the 4VBA/PSt macroRAFT ratio
increased, indicating an ideal amount of 4VBA insertion.
An optimal ratio of [PSt macroRAFT]:[AIBN]:[4VBA]
was 1.2:1:180. DSC and XRD confirmed the amorphous
structure of homo and copolymer. Thermal stability was
higher for PSt-b-P4VBA forming activated porous carbon
char by dehydration, carbonization and oxidation. SEM
and STEM observations showed a morphological evolution
between PSt macroRAFT and the correspondent
copolymer.The authors acknowledge the n-STeP-Nanostructured systems for Tailored Performance, with reference NORTE-07-0124-FEDER-000039, supported by the Programa Operacional Regional do Norte (ON.2), PEst-C/CTM/LA0025/2013 (Strategic Project-LA 25-2013-2014)
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Evaluation of Typhoid Conjugate Vaccine Effectiveness in Ghana (TyVEGHA) Using a Cluster-Randomized Controlled Phase IV Trial: Trial Design and Population Baseline Characteristics.
Typhoid fever remains a significant health problem in sub-Saharan Africa, with incidence rates of >100 cases per 100,000 person-years of observation. Despite the prequalification of safe and effective typhoid conjugate vaccines (TCV), some uncertainties remain around future demand. Real-life effectiveness data, which inform public health programs on the impact of TCVs in reducing typhoid-related mortality and morbidity, from an African setting may help encourage the introduction of TCVs in high-burden settings. Here, we describe a cluster-randomized trial to investigate population-level protection of TYPBAR-TCVÂź, a Vi-polysaccharide conjugated to a tetanus-toxoid protein carrier (Vi-TT) against blood-culture-confirmed typhoid fever, and the synthesis of health economic evidence to inform policy decisions. A total of 80 geographically distinct clusters are delineated within the Agogo district of the Asante Akim region in Ghana. Clusters are randomized to the intervention arm receiving Vi-TT or a control arm receiving the meningococcal A conjugate vaccine. The primary study endpoint is the total protection of Vi-TT against blood-culture-confirmed typhoid fever. Total, direct, and indirect protection are measured as secondary outcomes. Blood-culture-based enhanced surveillance enables the estimation of incidence rates in the intervention and control clusters. Evaluation of the real-world impact of TCVs and evidence synthesis improve the uptake of prequalified/licensed safe and effective typhoid vaccines in public health programs of high burden settings. This trial is registered at the Pan African Clinical Trial Registry, accessible at Pan African Clinical Trials Registry (ID: PACTR202011804563392)
Evaluation of Typhoid Conjugate Vaccine Effectiveness in Ghana (TyVEGHA) Using a Cluster-Randomized Controlled Phase IV Trial: Trial Design and Population Baseline Characteristics.
Typhoid fever remains a significant health problem in sub-Saharan Africa, with incidence rates of >100 cases per 100,000 person-years of observation. Despite the prequalification of safe and effective typhoid conjugate vaccines (TCV), some uncertainties remain around future demand. Real-life effectiveness data, which inform public health programs on the impact of TCVs in reducing typhoid-related mortality and morbidity, from an African setting may help encourage the introduction of TCVs in high-burden settings. Here, we describe a cluster-randomized trial to investigate population-level protection of TYPBAR-TCVÂź, a Vi-polysaccharide conjugated to a tetanus-toxoid protein carrier (Vi-TT) against blood-culture-confirmed typhoid fever, and the synthesis of health economic evidence to inform policy decisions. A total of 80 geographically distinct clusters are delineated within the Agogo district of the Asante Akim region in Ghana. Clusters are randomized to the intervention arm receiving Vi-TT or a control arm receiving the meningococcal A conjugate vaccine. The primary study endpoint is the total protection of Vi-TT against blood-culture-confirmed typhoid fever. Total, direct, and indirect protection are measured as secondary outcomes. Blood-culture-based enhanced surveillance enables the estimation of incidence rates in the intervention and control clusters. Evaluation of the real-world impact of TCVs and evidence synthesis improve the uptake of prequalified/licensed safe and effective typhoid vaccines in public health programs of high burden settings. This trial is registered at the Pan African Clinical Trial Registry, accessible at Pan African Clinical Trials Registry (ID: PACTR202011804563392)
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at â s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fbâ1 of â s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
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
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