1,805 research outputs found
Maternal and perinatal outcomes after elective labor induction at 39 weeks in uncomplicated singleton pregnancies: a meta-analysis.
Objective
The rate of maternal and perinatal complications increases after 39 weeks' gestation in both unselected and complicated pregnancies. The aim of this study was to synthesize quantitatively the available evidence on the effect of elective induction of labor at 39 weeks on the risk of Cesarean section, and on maternal and perinatal outcomes.
Methods
PubMed, US Registry of Clinical Trials, SCOPUS and CENTRAL databases were searched from inception to August 2018. Additionally, the references of retrieved articles were searched. Eligible studies were randomized controlled trials of singleton uncomplicated pregnancies in which participants were randomized between 39 + 0 and 39 + 6 gestational weeks to either induction of labor or expectant management. The risk of bias of individual studies was assessed using the Cochrane Risk of Bias Tool. The overall quality of evidence was assessed according to the GRADE guideline. Primary outcomes included Cesarean section, maternal death and admission to the neonatal intensive care unit (NICU). Secondary outcomes included operative delivery, Grade‐3/4 perineal laceration, postpartum hemorrhage, maternal infection, hypertensive disease of pregnancy, maternal thrombotic events, length of maternal hospital stay, neonatal death, need for neonatal respiratory support, cerebral palsy, length of stay in NICU and length of neonatal hospital stay. Pooled risk ratios (RRs) were calculated using random‐effects models.
Results
The meta‐analysis included five studies (7261 cases). Induction of labor was associated with a decreased risk for Cesarean section (moderate quality of evidence; RR 0.86 (95% CI, 0.78–0.94); I2 = 0.1%), maternal hypertension (moderate quality of evidence; RR 0.65 (95% CI, 0.57–0.75); I2 = 0%) and neonatal respiratory support (moderate quality of evidence; RR 0.73 (95% CI, 0.58–0.95); I2 = 0%). Neonates born after induction weighed, on average, 81 g (95% CI, 63–100 g) less than those born after expectant management. No significant effects were found for the other outcomes with the available data. The main limitation of our analysis was that the majority of data were derived from a single large study. A second limitation arose from the open‐label design of the studies, which may theoretically have affected the readiness of the attending clinician to resort to Cesarean section.
Conclusions
Elective induction of labor in uncomplicated singleton pregnancy at 39 weeks' gestation is not associated with maternal or perinatal complications and may reduce the need for Cesarean section, risk of hypertensive disease of pregnancy and need for neonatal respiratory support
Mechanics and dynamics of X-chromosome pairing at X inactivation
At the onset of X-chromosome inactivation, the vital process whereby female mammalian cells equalize X products with
respect to males, the X chromosomes are colocalized along their Xic (X-inactivation center) regions. The mechanism
inducing recognition and pairing of the X’s remains, though, elusive. Starting from recent discoveries on the molecular
factors and on the DNA sequences (the so-called "pairing sites") involved, we dissect the mechanical basis of Xic
colocalization by using a statistical physics model. We show that soluble DNA-specific binding molecules, such as those
experimentally identified, can be indeed sufficient to induce the spontaneous colocalization of the homologous
chromosomes but only when their concentration, or chemical affinity, rises above a threshold value as a consequence of a
thermodynamic phase transition. We derive the likelihood of pairing and its probability distribution. Chromosome dynamics
has two stages: an initial independent Brownian diffusion followed, after a characteristic time scale, by recognition and
pairing. Finally, we investigate the effects of DNA deletion/insertions in the region of pairing sites and compare model
predictions to available experimental data
Evolutionary relationships between Rhynchosporium lolii sp. nov. and other Rhynchosporium species on grass.
Copyright: 2013 King et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedThe fungal genus Rhynchosporium (causative agent of leaf blotch) contains several host-specialised species, including R. commune (colonising barley and brome-grass), R. agropyri (couch-grass), R. secalis (rye and triticale) and the more distantly related R. orthosporum (cocksfoot). This study used molecular fingerprinting, multilocus DNA sequence data, conidial morphology, host range tests and scanning electron microscopy to investigate the relationship between Rhynchosporium species on ryegrasses, both economically important forage grasses and common wild grasses in many cereal growing areas, and other plant species. Two different types of Rhynchosporium were found on ryegrasses in the UK. Firstly, there were isolates of R. commune that were pathogenic to both barley and Italian ryegrass. Secondly, there were isolates of a new species, here named R. lolii, that were pathogenic only to ryegrass species. R. lolii was most closely related to R. orthosporum, but exhibited clear molecular, morphological and host range differences. The species was estimated to have diverged from R. orthosporum ca. 5735 years before the present. The colonisation strategy of all of the different Rhynchosporium species involved extensive hyphal growth in the sub-cuticular regions of the leaves. Finally, new species-specific PCR diagnostic tests were developed that could distinguish between these five closely related Rhynchosporium species.Peer reviewedFinal Published versio
Seagrass can mitigate negative ocean acidification effects on calcifying algae
The ultimate effect that ocean acidification (OA) and warming will have on the physiology of calcifying algae is still largely uncertain. Responses depend on the complex interactions between seawater chemistry, global/local stressors and species-specific physiologies. There is a significant gap regarding the effect that metabolic interactions between coexisting species may have on local seawater chemistry and the concurrent effect of OA. Here, we manipulated CO2 and temperature to evaluate the physiological responses of two common photoautotrophs from shallow tropical marine coastal ecosystems in Brazil: the calcifying alga Halimeda cuneata, and the seagrass Halodule wrightii. We tested whether or not seagrass presence can influence the calcification rate of a widespread and abundant species of Halimeda under OA and warming. Our results demonstrate that under elevated CO2, the high photosynthetic rates of H. wrightii contribute to raise H. cuneata calcification more than two-fold and thus we suggest that H. cuneata populations coexisting with H. wrightii may have a higher resilience to OA conditions. This conclusion supports the more general hypothesis that, in coastal and shallow reef environments, the metabolic interactions between calcifying and non-calcifying organisms are instrumental in providing refuge against OA effects and increasing the resilience of the more OA-susceptible species.E.B. would like to thank the Coordenação de Aperfeiçoamento de Pessoas de Nível Superior (CAPES) for Masters
funding. Funding for this project came from the Synergism grant (CNPq 407365/2013-3). We extend our thanks
to the Brazil-based Projeto Coral Vivo and its sponsor PetroBras Ambiental for providing the Marine Mesocosm
structure and experimental assistance.info:eu-repo/semantics/publishedVersio
Structure of the hDmc1-ssDNA filament reveals the principles of its architecture
In eukaryotes, meiotic recombination is a major source of genetic diversity, but its defects in humans lead to abnormalities such as Down's, Klinefelter's and other syndromes. Human Dmc1 (hDmc1), a RecA/Rad51 homologue, is a recombinase that plays a crucial role in faithful chromosome segregation during meiosis. The initial step of homologous recombination occurs when hDmc1 forms a filament on single-stranded (ss) DNA. However the structure of this presynaptic complex filament for hDmc1 remains unknown. To compare hDmc1-ssDNA complexes to those known for the RecA/Rad51 family we have obtained electron microscopy (EM) structures of hDmc1-ssDNA nucleoprotein filaments using single particle approach. The EM maps were analysed by docking crystal structures of Dmc1, Rad51, RadA, RecA and DNA. To fully characterise hDmc1-DNA complexes we have analysed their organisation in the presence of Ca2+, Mg2+, ATP, AMP-PNP, ssDNA and dsDNA. The 3D EM structures of the hDmc1-ssDNA filaments allowed us to elucidate the principles of their internal architecture. Similar to the RecA/Rad51 family, hDmc1 forms helical filaments on ssDNA in two states: extended (active) and compressed (inactive). However, in contrast to the RecA/Rad51 family, and the recently reported structure of hDmc1-double stranded (ds) DNA nucleoprotein filaments, the extended (active) state of the hDmc1 filament formed on ssDNA has nine protomers per helical turn, instead of the conventional six, resulting in one protomer covering two nucleotides instead of three. The control reconstruction of the hDmc1-dsDNA filament revealed 6.4 protein subunits per helical turn indicating that the filament organisation varies depending on the DNA templates. Our structural analysis has also revealed that the N-terminal domain of hDmc1 accomplishes its important role in complex formation through domain swapping between adjacent protomers, thus providing a mechanistic basis for coordinated action of hDmc1 protomers during meiotic recombination
Cross-sectional analysis of association between socioeconomic status and utilization of primary total hip joint replacements 2006-7 : Australian orthopaedic association national joint replacement registry
Background The utilization of total hip replacement (THR) surgery is rapidly increasing, however few data examine whether these procedures are associated with socioeconomic status (SES) within Australia. This study examined primary THR across SES for both genders for the Barwon Statistical Division (BSD) of Victoria, Australia.Methods Using the Australian Orthopaedic Association National Joint Replacement Registry data for 2006–7, primary THR with a diagnosis of osteoarthritis (OA) among residents of the BSD was ascertained. The Index of Relative Socioeconomic Disadvantage was used to measure SES; determined by matching residential addresses with Australian Bureau of Statistics census data. The data were categorised into quintiles; quintile 1 indicating the most disadvantaged. Age- and sex-specific rates of primary THR per 1,000 person years were reported for 10-year age bands using the total population at risk.Results Females accounted for 46.9% of the 642 primary THR performed during 2006–7. THR utilization per 1,000 person years was 1.9 for males and 1.5 for females. The highest utilization of primary THR was observed in those aged 70–79 years (males 6.1, and females 5.4 per 1,000 person years). Overall, the U-shaped pattern of THR across SES gave the appearance of bimodality for both males and females, whereby rates were greater for both the most disadvantaged and least disadvantaged groups.Conclusions Further work on a larger scale is required to determine whether relationships between SES and THR utilization for the diagnosis of OA is attributable to lifestyle factors related to SES, or alternatively reflects geographic and health system biases. Identifying contributing factors associated with SES may enhance resource planning and enable more effective and focussed preventive strategies for hip OA. <br /
Differences between <i>Trypanosoma brucei gambiense</i> groups 1 and 2 in their resistance to killing by Trypanolytic factor 1
<p><b>Background:</b> The three sub-species of <i>Trypanosoma brucei</i> are important pathogens of sub-Saharan Africa. <i>T. b. brucei</i> is unable to infect humans due to sensitivity to trypanosome lytic factors (TLF) 1 and 2 found in human serum. <i>T. b. rhodesiense</i> and <i>T. b. gambiense</i> are able to resist lysis by TLF. There are two distinct sub-groups of <i>T. b. gambiense</i> that differ genetically and by human serum resistance phenotypes. Group 1 <i>T. b. gambiense</i> have an invariant phenotype whereas group 2 show variable resistance. Previous data indicated that group 1 <i>T. b. gambiense</i> are resistant to TLF-1 due in-part to reduced uptake of TLF-1 mediated by reduced expression of the TLF-1 receptor (the haptoglobin-hemoglobin receptor (<i>HpHbR</i>)) gene. Here we investigate if this is also true in group 2 parasites.</p> 
<p><b>Methodology:</b> Isogenic resistant and sensitive group 2 <i>T. b. gambiense</i> were derived and compared to other T. brucei parasites. Both resistant and sensitive lines express the <i>HpHbR</i> gene at similar levels and internalized fluorescently labeled TLF-1 similar fashion to <i>T. b. brucei</i>. Both resistant and sensitive group 2, as well as group 1 <i>T. b. gambiense</i>, internalize recombinant APOL1, but only sensitive group 2 parasites are lysed.</p> 
<p><b>Conclusions:</b> Our data indicate that, despite group 1 <i>T. b. gambiense</i> avoiding TLF-1, it is resistant to the main lytic component, APOL1. Similarly group 2 <i>T. b. gambiense</i> is innately resistant to APOL1, which could be based on the same mechanism. However, group 2 <i>T. b. gambiense</i> variably displays this phenotype and expression does not appear to correlate with a change in expression site or expression of <i>HpHbR</i>. Thus there are differences in the mechanism of human serum resistance between <i>T. b. gambiense</i> groups 1 and 2.</p>
Reaction rates and transport in neutron stars
Understanding signals from neutron stars requires knowledge about the
transport inside the star. We review the transport properties and the
underlying reaction rates of dense hadronic and quark matter in the crust and
the core of neutron stars and point out open problems and future directions.Comment: 74 pages; commissioned for the book "Physics and Astrophysics of
  Neutron Stars", NewCompStar COST Action MP1304; version 3: minor changes,
  references updated, overview graphic added in the introduction, improvements
  in Sec IV.A.
Recommended from our members
Bioavailability in soils
The consumption of locally-produced vegetables by humans may be an important exposure pathway for soil contaminants in many urban settings and for agricultural land use. Hence, prediction of metal and metalloid uptake by vegetables from contaminated soils is an important part of the Human Health Risk Assessment procedure. The behaviour of metals (cadmium, chromium, cobalt, copper, mercury, molybdenum, nickel, lead and zinc) and metalloids (arsenic, boron and selenium) in contaminated soils depends to a large extent on the intrinsic charge, valence and speciation of the contaminant ion, and soil properties such as pH, redox status and contents of clay and/or organic matter. However, chemistry and behaviour of the contaminant in soil alone cannot predict soil-to-plant transfer. Root uptake, root selectivity, ion interactions, rhizosphere processes, leaf uptake from the atmosphere, and plant partitioning are important processes that ultimately govern the accumulation ofmetals and metalloids in edible vegetable tissues. Mechanistic models to accurately describe all these processes have not yet been developed, let alone validated under field conditions. Hence, to estimate risks by vegetable consumption, empirical models have been used to correlate concentrations of metals and metalloids in contaminated soils, soil physico-chemical characteristics, and concentrations of elements in vegetable tissues. These models should only be used within the bounds of their calibration, and often need to be re-calibrated or validated using local soil and environmental conditions on a regional or site-specific basis.Mike J. McLaughlin, Erik Smolders, Fien Degryse, and Rene Rietr
Laser-induced fluorescence velocimetry for a hypersonic leading-edge separation
Two-dimensional mapping of the velocity distribution for a hypersonic leading-edge separation flowfield generated by a "tick" shaped geometry is presented for the first time. Discrete measurements of two velocity components were acquired at a flow condition having a total specific enthalpy of 3.8 MJ/kg by imaging nitric oxide fluorescence over numerous runs of the hypersonic tunnel at the Australian Defence Force Academy (T-ADFA). The measured freestream velocity distribution exhibited some non-uniformity, which is hypothesized to originate from images acquired using a set of ultraviolet specific mirrors mounted on the shock tunnel deflecting under load during a run of the facility, slightly changing the laser sheet orientation. The flow separation point was measured to occur at 1.4 ± 0.2 mm from the model leading edge, based on the origin of the free shear layer emanating from the expansion surface. Reattachment of this free shear layer on the compression surface occurred at 59.0 ± 0.2 mm from the model vertex. Recirculating the flow bound by the separation and reattachment points contained supersonic reverse flow and areas of subsonic flow aligned with the location of three identified counter-rotating vortices. A comparison of the recirculation flow streamline plots with those computed using Navier-Stokes and direct simulation Monte Carlo (DSMC) codes showed differences in flow structures. At a flow time close to that produced by the facility, flow structures generated by the DSMC solution were seen to agree more favorably with the experiment than those generated by the Navier-Stokes solver due to its ability to better characterize separation by modeling the strong viscous interactions and rarefaction at the leading edge. The primary reason for this is that the no-slip condition used in the Navier-Stokes solution predicts a closer separation point to the leading edge and structures when compared to the DSMC solution, which affects surface shear stress and heat flux, leading to a difference in flow structures downstream of the separation
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