Proximate controls on semiarid soil greenhouse gas fluxes across 3 million years of soil development

Soils are important sources and sinks of three greenhouse gases (GHGs): carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). However, it is unknown whether semiarid landscapes are important contributors to global fluxes of these gases, partly because our mechanistic understanding of soil GHG fluxes is largely derived from more humid ecosystems. We designed this study with the objective of identifying the important soil physical and biogeochemical controls on soil GHG fluxes in semiarid soils by observing seasonal changes in soil GHG fluxes across a three million year substrate age gradient in northern Arizona. We also manipulated soil nitrogen (N) and phosphorus availability with 7 years of fertilization and used regression tree analysis to identify drivers of unfertilized and fertilized soil GHG fluxes. Similar to humid ecosystems, soil N2O flux was correlated with changes in N and water availability and soil CO2 efflux was correlated with changes in water availability and temperature. Soil CH4 uptake was greatest in relatively colder and wetter soils. While fertilization had few direct effects on soil CH4 flux, soil nitrate was an important predictor of soil CH4 uptake in unfertilized soils and soil ammonium was an important predictor of soil CH4 uptake in fertilized soil. Like in humid ecosystems, N gas loss via nitrification or denitrification appears to increase with increases in N and water availability during ecosystem development. Our results suggest that, with some exceptions, the drivers of soil GHG fluxes in semiarid ecosystems are often similar to those observed in more humid ecosystems

Having a baby in your 40s with ART: the reproductive dilemma of autologous versus donor oocytes.

BACKGROUND:Increasing numbers of women ≥40 years old are accessing assisted reproductive technology (ART) due to age-related infertility. There is limited population-based evidence about the impact on the cumulative live birth rate (CLBR) of women aged ≥40 years using their own oocytes, compared to women of a similar age, using donor oocytes. AIMS:To compare the CLBR for women ≥40 years undergoing ART using autologous oocytes and women of similar age using donor oocytes. MATERIALS AND METHODS:This population-based retrospective cohort study used data from all women aged ≥40 years undergoing ART with donated (n = 987) or autologous oocytes (n = 19 170) in Victoria, Australia between 2009 and 2016. A discrete-time survival model was used to evaluate the CLBR following ART with donor or autologous oocytes. The odds ratio, adjusted for woman's age; male age; parity; cause of infertility; and the associated 95% confidence intervals (CI), were calculated. The numbers needed to be exposed (NNEs) were calculated from the adjusted odds ratio (aOR) and the CLBR in the autologous group. RESULTS:The CLBR ranged from 28.6 to 42.5% in the donor group and from 12.5% to 1.4% in the autologous group. The discrete-time survival analysis with 95% CI demonstrated significant aOR on CLBR across all ages (range aOR: 2.56, 95% CI: 1.62-4.01 to aOR: 15.40, 95% CI: 9.10-26.04). CONCLUSIONS:Women aged ≥40 years, using donor oocytes had a significantly higher CLBR than women using autologous oocytes. The findings can be used when counselling women ≥40 years about their ART treatment options and to inform public policy

Oocyte donor age has a significant impact on oocyte recipients' cumulative live-birth rate: a population-based cohort study

© 2019 Objective: To study the impact of the donor's and recipient's age on the cumulative live-birth rate (CLBR) in oocyte donation cycles. Design: A population-based retrospective cohort study. Setting: Not applicable. Patient(s): All women using donated oocytes (n = 1,490) in Victoria, Australia, between 2009 and 2015. Intervention(s): None. Main Outcome Measure(s): The association between the donor's and recipient's age and CLBR modeled by multivariate Cox proportional hazard regression with the covariates of male partner's age, recipient parity, and cause of infertility adjusted for, and donor age grouped as <30, 30–34, 35–37, 38–40, and ≥41 years, and recipient age as <35, 35–37, 38–40, 41–42, 43–44, and ≥45 years. Result(s): The mean age of the oocyte donors was 33.7 years (range: 21 to 45 years) with 49% aged 35 years and over. The mean age of the oocyte recipients was 41.4 years (range: 19 to 53 years) with 25.4% aged ≥45 years. There was a statistically significant relationship between the donor's age and the CLBR. The CLBR for recipients with donors aged <30 years and 30–34 years was 44.7% and 43.3%, respectively. This decreased to 33.6% in donors aged 35–37 years, 22.6% in donors aged 38–40 years, and 5.1% in donors aged ≥41 years. Compared with recipients with donors aged <30 years, the recipients with donors aged 38–40 years had 40% less chance of achieving a live birth (adjusted hazard ratio 0.60; 95% CI, 0.43–0.86) and recipients with donors aged ≥41 years had 86% less chance of achieving a live birth (adjusted hazard ratio 0.14; 95% CI, 0.04–0.44). The multivariate analysis showed no statistically significant effect of the recipient's age on CLBR. Conclusion(s): We have demonstrated that the age of the oocyte donor is critical to the CLBR and is independent of the recipient woman's age. Recipients using oocytes from donors aged ≥35 years had a statistically significantly lower CLBR when compared with recipients using oocytes from donors aged <35 years

Strong Double Higgs Production at the LHC

The hierarchy problem and the electroweak data, together, provide a plausible motivation for considering a light Higgs emerging as a pseudo-Goldstone boson from a strongly-coupled sector. In that scenario, the rates for Higgs production and decay differ significantly from those in the Standard Model. However, one genuine strong coupling signature is the growth with energy of the scattering amplitudes among the Goldstone bosons, the longitudinally polarized vector bosons as well as the Higgs boson itself. The rate for double Higgs production in vector boson fusion is thus enhanced with respect to its negligible rate in the SM. We study that reaction in pp collisions, where the production of two Higgs bosons at high pT is associated with the emission of two forward jets. We concentrate on the decay mode hh -> WW^(*)WW^(*) and study the semi-leptonic decay chains of the W's with 2, 3 or 4 leptons in the final states. While the 3 lepton final states are the most relevant and can lead to a 3 sigma signal significance with 300 fb^{-1} collected at a 14 TeV LHC, the two same-sign lepton final states provide complementary information. We also comment on the prospects for improving the detectability of double Higgs production at the foreseen LHC energy and luminosity upgrades.Comment: 54 pages, 26 figures. v2: typos corrected, a few comments and one table added. Version published in JHE

The effect of total arterial grafting on medium-term outcomes following coronary artery bypass grafting

<p>Abstract</p> <p>Background</p> <p>While it is believed that total arterial grafting (TAG) for coronary artery bypass grafting (CABG) confers improved long-term outcomes when compared to conventional grafting with left internal mammary artery and saphenous vein grafts (LIMA+SVG), to date, this has not become the standard of care. In this study, we assessed the impact of TAG on medium-term outcomes after CABG.</p> <p>Methods</p> <p>Peri-operative data was prospectively collected on consecutive first-time, isolated CABG patients between 1995 and 2005. Patients were divided into two groups based on grafting strategy: TAG (all arterial grafts no saphenous veins) or LIMA+SVG. Patients who had an emergent status or underwent fewer than two distal bypasses were excluded. Medium term univariate and risk-adjusted comparisons between TAG and LIMA+SVG cases were performed.</p> <p>Results</p> <p>A total of 4696 CABG patients were included with 1019 patients undergoing TAG (22%). Unadjusted in-hospital mortality was 1.5% for TAG patients compared to 2.0% for LIMA+SVG (p = 0.31). The mean follow-up was 4.8 ± 2.0 years for TAG patients compared to 6.1 ± 3.0 years for LIMA+SVG patients (p < 0.0001). At follow-up total mortality (8% vs 19%; p < 0.0001), and the incidence of readmission to hospital for cardiac reasons (29% vs 38%; p < 0.0001) were significantly lower in TAG compared to LIMA+SVG patients. However, after adjusting for clinical covariates, TAG did not emerge as a significant independent predictor of long-term mortality (HR 0.92; CI 0.71–1.18), readmission to hospital (HR 1.02; CI 0.89–1.18) or the composite outcome of mortality and readmission (HR 1.00; CI 0.88–1.15). Risk adjusted survival was better than 88% in both TAG and LIMA-SVG patients at 5 years follow-up.</p> <p>Conclusion</p> <p>Patients undergoing TAG appear to experience lower rates of medium-term all-cause mortality and readmission to hospital for any cardiac cause when compared to patients undergoing LIMA+SVG. However, after adjusting for clinical variables, this difference no longer persists suggesting that at median follow-up there are no mortality or morbidity benefit based on the choice of conduit.</p

CASP8 variants D302H and −652 6N ins/del do not influence the risk of colorectal cancer in the United Kingdom population

Polymorphisms in CASP8 at 2q33.1 have been associated with the risk of developing cancer, specifically, the D302H variant (rs1045485) with breast cancer in the European population and the −652 6N ins/del promoter variant (rs3834129) with multiple tumours including colorectal cancer (CRC) in the Chinese population. We evaluated the relationship between −652 6N ins/del and D302H variants and risk of developing CRC in the UK population by genotyping 4016 cases and 3749 controls. Both variants showed no evidence of an association with risk of developing CRC (P=0.42 and 0.22, respectively). In contrast, the recently identified CRC susceptibility allele rs6983267 mapping to 8q24 was significantly associated with disease risk (P=8.94 × 10−8). It is thus very unlikely that variation in CASP8 defined by −652 6N ins/del or D302H influences the risk of CRC in European populations. The implications of our findings both in terms of population-specific effects and publication bias are discussed

Increased levels of (class switched) memory B cells in peripheral blood of current smokers

There is increasing evidence that a specific immune response contributes to the pathogenesis of COPD. B-cell follicles are present in lung tissue and increased anti-elastin titers have been found in plasma of COPD patients. Additionally, regulatory T cells (Tregs) have been implicated in its pathogenesis as they control immunological reactions. We hypothesize that the specific immune response in COPD is smoke induced, either by a direct effect of smoking or as a result of smoke-induced lung tissue destruction (i.e. formation of neo-epitopes or auto antigens). Furthermore, we propose that Tregs are involved in the suppression of this smoke-induced specific immune response

Factorization and resummation of s-channel single top quark production

In this paper we study the factorization and resummation of s-channel single top quark production in the Standard Model at both the Tevatron and the LHC. We show that the production cross section in the threshold limit can be factorized into a convolution of hard function, soft function and jet function via soft-collinear-effective-theory (SCET), and resummation can be performed using renormalization group equation in the momentum space resummation formalism. We find that in general, the resummation effects enhance the Next-to-Leading-Order (NLO) cross sections by about $3$ at both the Tevatron and the LHC, and significantly reduce the factorization scale dependence of the total cross section at the Tevatron, while at the LHC we find that the factorization scale dependence has not been improved, compared with the NLO results.Comment: 29 pages, 7 figures; version published in JHE