672 research outputs found

    Assessing the association between oral hygiene and preterm birth by quantitative light-induced fluorescence

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    The aim of this study was to investigate the purported link between oral hygiene and preterm birth by using image analysis tools to quantify dental plaque biofilm. Volunteers (η = 91) attending an antenatal clinic were identified as those considered to be “at high risk” of preterm delivery (i.e., a previous history of idiopathic preterm delivery, case group) or those who were not considered to be at risk (control group). The women had images of their anterior teeth captured using quantitative light-induced fluorescence (QLF). These images were analysed to calculate the amount of red fluorescent plaque (ΔR%) and percentage of plaque coverage. QLF showed little difference in ΔR% between the two groups, 65.00% case versus 68.70% control, whereas there was 19.29% difference with regard to the mean plaque coverage, 25.50% case versus 20.58% control. A logistic regression model showed a significant association between plaque coverage and case/control status (Ρ = 0.031), controlling for other potential predictor variables, namely, smoking status, maternal age, and body mass index (BMI)

    Biomarkers of Tuberculosis Severity and Treatment Effect: A Directed Screen of 70 Host Markers in a Randomized Clinical Trial.

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    More efficacious treatment regimens are needed for tuberculosis, however, drug development is impeded by a lack of reliable biomarkers of disease severity and of treatment effect. We conducted a directed screen of host biomarkers in participants enrolled in a tuberculosis clinical trial to address this need. Serum samples from 319 protocol-correct, culture-confirmed pulmonary tuberculosis patients treated under direct observation as part of an international, phase 2 trial were screened for 70 markers of infection, inflammation, and metabolism. Biomarker assays were specifically developed for this study and quantified using a novel, multiplexed electrochemiluminescence assay. We evaluated the association of biomarkers with baseline characteristics, as well as with detailed microbiologic data, using Bonferroni-adjusted, linear regression models. Across numerous analyses, seven proteins, SAA1, PCT, IL-1β, IL-6, CRP, PTX-3 and MMP-8, showed recurring strong associations with markers of baseline disease severity, smear grade and cavitation; were strongly modulated by tuberculosis treatment; and had responses that were greater for patients who culture-converted at 8weeks. With treatment, all proteins decreased, except for osteocalcin, MCP-1 and MCP-4, which significantly increased. Several previously reported putative tuberculosis-associated biomarkers (HOMX1, neopterin, and cathelicidin) were not significantly associated with treatment response. In conclusion, across a geographically diverse and large population of tuberculosis patients enrolled in a clinical trial, several previously reported putative biomarkers were not significantly associated with treatment response, however, seven proteins had recurring strong associations with baseline radiographic and microbiologic measures of disease severity, as well as with early treatment response, deserving additional study

    A PPMAP analysis of the filamentary structures in Ophiuchus L1688 and L1689

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    We use the PPMAP (Point Process MAPping) algorithm to re-analyse the \textit{Herschel} and SCUBA-2 observations of the L1688 and L1689 sub-regions of the Ophiuchus molecular cloud. PPMAP delivers maps with high resolution (here 14′′14'', corresponding to ∼0.01 pc\sim 0.01\,{\rm pc} at ∼140 pc\sim 140\,{\rm pc}), by using the observations at their native resolutions. PPMAP also delivers more accurate dust optical depths, by distinguishing dust of different types and at different temperatures. The filaments and prestellar cores almost all lie in regions with NH2≳7×1021 cm−2N_{\rm H_2}\gtrsim 7\times 10^{21}\,{\rm cm}^{-2} (corresponding to AV≳7A_{_{\rm V}}\gtrsim 7). The dust temperature, TT, tends to be correlated with the dust opacity index, β\beta, with low TT and low β\beta tend concentrated in the interiors of filaments. The one exception to this tendency is a section of filament in L1688 that falls -- in projection -- between the two B stars, S1 and HD147889; here TT and β\beta are relatively high, and there is compelling evidence that feedback from these two stars has heated and compressed the filament. Filament {\sc fwhm}s are typically in the range 0.10 pc0.10\,{\rm pc} to 0.15 pc0.15\,{\rm pc}. Most filaments have line densities in the range 25 M⊙ pc−125\,{\rm M_{_\odot}\,pc^{-1}} to 65 M⊙ pc−165\,{\rm M_{_\odot}\,pc^{-1}}. If their only support is thermal gas pressure, and the gas is at the canonical temperature of 10 K10\,{\rm K}, the filaments are highly supercritical. However, there is some evidence from ammonia observations that the gas is significantly warmer than this, and we cannot rule out the possibility of additional support from turbulence and/or magnetic fields. On the basis of their spatial distribution, we argue that most of the starless cores are likely to disperse (rather than evolving to become prestellar).Comment: 22 pages, 18 figures, Accepted for publication by MNRAS March 202

    Collapse of Rotating Magnetized Molecular Cloud Cores and Mass Outflows

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    Collapse of the rotating magnetized molecular cloud core is studied with the axisymmetric magnetohydrodynamical (MHD) simulations. Due to the change of the equation of state of the interstellar gas, the molecular cloud cores experience several different phases as collapse proce eds. In the isothermal run-away collapse (n≲1010H2cm−3n \lesssim 10^{10}{\rm H_2 cm}^{-3}), a pseudo-disk is formed and it continues to contract till the opaque core is fo rmed at the center. In this disk, a number of MHD fast and slow shock pairs appear running parallelly to the disk. After the equation of state becomes hard, an adiabatic core is formed, which is separated from the isothermal contracting pseudo-disk by the accretion shock front facing radially outwards. By the effect of the magnetic tension, the angular momentum is transferred from the disk mid-plane to the surface. The gas with excess angular momentum near the surface is finally ejected, which explains the molecular bipolar outflow. Two types of outflows are observed. When the poloidal magnetic field is strong (magnetic energy is comparable to the thermal one), a U-shaped outflow is formed in which fast moving gas is confined to the wall whose shape looks like a capit al letter U. The other is the turbulent outflow in which magnetic field lines and velocity fi elds are randomly oriented. In this case, turbulent gas moves out almost perpendicularly from the disk. The continuous mass accretion leads to the quasistatic contraction of the first core. A second collapse due to dissociation of H2_2 in the first core follows. Finally another quasistatic core is again formed by atomic hydrogen (the second core). It is found that another outflow is ejected around the second atomic core, which seems to correspond to the optical jets or the fast neutral winds.Comment: submitted to Ap

    High-Mass Proto-Stellar Candidates - II : Density structure from dust continuum and CS emission

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    We present a detailed 1.2 mm continuum and CS spectral line study of a large sample of 69 massive star forming regions in very early stages of evolution, most of them prior to building up an ultracompact HII region. The continuum data show a zoo of different morphologies and give detailed information on the spatial distributions, the masses, column densities and average densities of the whole sample. Fitting the radial intensity profiles shows that three parameters are needed to describe the spatial distribution of the sources: constant emission from the center out to a few arcsec radius followed by a first power law intensity distribution which steepens further outside into a second power law distribution. The mean inner power law intensity index mi (I~r^(-mi)) is 1.2 corresponding to density indices p (n~r^(-p)) of 1.6. In total the density distribution of our massive star formations sites seem to be not too different from their low-mass counterparts, but we show that setting tight constrains on the density indices is very difficult and subject to many possible errors. The local densities we derive from CS calculations are higher (up to one order of magnitude) than the mean densities we find via the mm-continuum. Such inhomogeneous density distribution reflects most likely the ubiquitous phenomenon of clumping and fragmentation in molecular clouds. Linewidth-mass relations show a departure from virial equilibrium in the stages of strongly collapsing cores.Comment: 15 pages, 13 jpeg-figures. Astrophysical Journal, in pres

    The genetic organisation of prokaryotic two-component system signalling pathways

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    <p>Abstract</p> <p>Background</p> <p>Two-component systems (TCSs) are modular and diverse signalling pathways, involving a stimulus-responsive transfer of phosphoryl groups from transmitter to partner receiver domains. TCS gene and domain organisation are both potentially informative regarding biological function, interaction partnerships and molecular mechanisms. However, there is currently little understanding of the relationships between domain architecture, gene organisation and TCS pathway structure.</p> <p>Results</p> <p>Here we classify the gene and domain organisation of TCS gene loci from 1405 prokaryotic replicons (>40,000 TCS proteins). We find that 200 bp is the most appropriate distance cut-off for defining whether two TCS genes are functionally linked. More than 90% of all TCS gene loci encode just one or two transmitter and/or receiver domains, however numerous other geometries exist, often with large numbers of encoded TCS domains. Such information provides insights into the distribution of TCS domains between genes, and within genes. As expected, the organisation of TCS genes and domains is affected by phylogeny, and plasmid-encoded TCS exhibit differences in organisation from their chromosomally-encoded counterparts.</p> <p>Conclusions</p> <p>We provide here an overview of the genomic and genetic organisation of TCS domains, as a resource for further research. We also propose novel metrics that build upon TCS gene/domain organisation data and allow comparisons between genomic complements of TCSs. In particular, '<it>percentage orphaned TCS genes</it>' (or 'Dissemination') and '<it>percentage of complex loci</it>' (or 'Sophistication') appear to be useful discriminators, and to reflect mechanistic aspects of TCS organisation not captured by existing metrics.</p

    L1495 revisited: a ppmap view of a star-forming filament

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    We have analysed the Herschel and SCUBA-2 dust continuum observations of the main filament in the Taurus L1495 star-forming region, using the Bayesian fitting procedure PPMAP. (i) If we construct an average profile along the whole length of the filament, it has FWHM ≃0.087±0.003pc; but the closeness to previous estimates is coincidental. (ii) If we analyse small local sections of the filament, the column-density profile approximates well to the form predicted for hydrostatic equilibrium of an isothermal cylinder. (iii) The ability of PPMAP to distinguish dust emitting at different temperatures, and thereby to discriminate between the warm outer layers of the filament and the cold inner layers near the spine, leads to a significant reduction in the surface-density, Σ⁠, and hence in the line-density, μ. If we adopt the canonical value for the critical line-density at a gas-kinetic temperature of 10K⁠, μ_(CRIT) ≃ 16M⊙pc⁻¹⁠, the filament is on average trans-critical, with μ∼μ_(CRIT); local sections where μ > μ_(CRIT) tend to lie close to prestellar cores. (iv) The ability of PPMAP to distinguish different types of dust, i.e. dust characterized by different values of the emissivity index, β, reveals that the dust in the filament has a lower emissivity index, β ≲ 1.5, than the dust outside the filament, β ≳ 1.7, implying that the physical conditions in the filament have effected a change in the properties of the dust

    Dust in the eye of Andromeda

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    We present new Herschel-derived images of warm dust in the Andromeda galaxy, M31, with unprecedented spatial resolution (∟30 pc), column density accuracy, and constraints on the three-dimensional distributions of dust temperature and dust opacity index (hence grain size and composition), based on the new ppmap Bayesian analysis procedure. We confirm the overall radial variation of dust opacity index reported by other recent studies, including the central decrease within ∟3 kpc of the nucleus. We also investigate the detailed distribution of dust in the nuclear region, a prominent feature of which is an ∟500 pc bar-like structure seen previously in H ι. The nature of this feature has been the subject of some debate. Our maps show it to be the site of the warmest dust, with a mean line-of-sight temperature ∟30 K. A comparison with the stellar distribution, based on 2MASS data, provides strong evidence that it is a gravitationally induced bar. A comparison with radial velocity maps suggests the presence of an inflow towards the nucleus from opposite directions along this bar, fed presumably by the nuclear spiral with which it appears to connect. Such behaviour is common in large-scale bars in spiral galaxies, as is the phenomenon of nested bars whereby a subkiloparsec nuclear bar exists within a large-scale primary bar. We suggest that M31 represents an example of such nesting

    Effect of Axillary Dissection vs No Axillary Dissection on 10-Year Overall Survival Among Women With Invasive Breast Cancer and Sentinel Node Metastasis: The ACOSOG Z0011 (Alliance) Randomized Clinical Trial

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    The results of the American College of Surgeons Oncology Group Z0011 (ACOSOG Z0011) trial were first reported in 2005 with a median follow-up of 6.3 years. Longer follow-up was necessary because the majority of the patients had estrogen receptor–positive tumors that may recur later in the disease course (the ACOSOG is now part of the Alliance for Clinical Trials in Oncology)
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