Search for long-lived particles decaying to leptons with large impact parameter in proton-proton collisions at root s=13 TeV

A search for new long-lived particles decaying to leptons using proton–proton collision data produced by the CERN LHC at s√=13TeV is presented. Events are selected with two leptons (an electron and a muon, two electrons, or two muons) that both have transverse impact parameter values between 0.01 and 10cm and are not required to form a common vertex. Data used for the analysis were collected with the CMS detector in 2016, 2017, and 2018, and correspond to an integrated luminosity of 118 (113)fb−1 in the ee channel (eμ and μμ channels). The search is designed to be sensitive to a wide range of models with displaced eμ, ee, and μμ final states. The results constrain several well-motivated models involving new long-lived particles that decay to displaced leptons. For some areas of the available phase space, these are the most stringent constraints to date

Measurement of prompt D-0 and D-0 meson azimuthal anisotropy and search for strong electric fields in PbPb collisions at root S-NN=5.02 TeV

SCOAP

Paecilomyces niveus Stolk & Samson, 1971 (Ascomycota: Thermoascaceae) as a pathogen of Nasonovia ribisnigri (Mosley, 1841) (Hemiptera, Aphididae) in Brazil

Abstract Nasonovia ribisnigri is a key pest of lettuce (Lactuca sativa L.) in Brazil that requires alternative control methods to synthetic pesticides. We report, for the first time, the occurrence of Paecilomyces niveus as an entomopathogen of the aphid Nasonovia ribisnigri in Pinhais, Paraná, Brazil. Samples of mummified aphids were collected from lettuce crops. The fungus P. niveus (PaePR) was isolated from the insect bodies and identified by macro and micromorphology. The species was confirmed by sequencing Internal Transcribed Spacer (ITS) rDNA. We obtained a sequence of 528 bp (accession number HQ441751), which aligned with Byssochlamys nivea strains (100% identities). In a bioassay, 120 h after inoculation of N. ribisnigri with pathogenic P. niveus had an average mortality of 74%. The presence of P. niveus as a natural pathogen of N. ribisnigri in Brazil suggests that it may be possible to employ P. niveus to minimize the use of chemical insecticides

Biotic potential and reproductive parameters of Spodoptera dolichos (Lepidoptera: Noctuidae) in the laboratory

ABSTRACT The biotic potential and reproductive parameters of Spodoptera dolichos (Fabricius, 1794) were evaluated under controlled conditions (25 ± 1°C, 70 ± 10% RH and 14 hour photophase). The longevity, pre-, post- and oviposition periods, fecundity, and fertility of 25 couples were evaluated. The longevity of females (12.9 days) was not significantly different than that of males (12.4 days). The mean durations of the pre-, post- and oviposition periods were 3.0, 0.4 and 10.4 days, respectively. The mean fecundity was 4,086.0 eggs per female and mean fertility was 3,557.8 larvae per female. On average, a female copulated 1.4 times. The biotic potential of S. dolichos was estimated at 7.138 x 1018 individuals/female/year. The net reproductive rate (Ro) was 1,711.98 times per generation and the mean generation time (T) was 56.19 days. The intrinsic rate of increase (rm) was 0.133, with a finite rate of increase (l) of 1.142 per day. These results are compared with other species from Spodoptera and their relevance for management strategies of S. dolichos

Search for a right-handed W boson and a heavy neutrino in proton-proton collisions at root s=13 TeV

A search is presented for a right-handed W boson (WR) and a heavy neutrino (N), in a final state consisting of two same-flavor leptons (ee or μμ) and two quarks. The search is performed with the CMS experiment at the CERN LHC using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 138 fb−1. The search covers two regions of phase space, one where the decay products of the heavy neutrino are merged into a single large-area jet, and one where the decay products are well separated. The expected signal is characterized by an excess in the invariant mass distribution of the final-state objects. No significant excess over the standard model background expectations is observed. The observations are interpreted as upper limits on the product of WR production cross sections and branching fractions assuming that couplings are identical to those of the standard model W boson. For N masses mN equal to half the WR mass mWR (mN = 0.2 TeV), mWR is excluded at 95% confidence level up to 4.7 (4.8) and 5.0 (5.4) TeV for the electron and muon channels, respectively. This analysis provides the most stringent limits on the WR mass to date

Study of quark and gluon jet substructure in Z plus jet and dijet events from pp collisions

Measurements of jet substructure describing the composition of quark- and gluon-initiated jets are presented. Proton-proton (pp) collision data at √ s = 13 TeV collected with the CMS detector are used, corresponding to an integrated luminosity of 35.9 fb−1 . Generalized angularities are measured that characterize the jet substructure and distinguish quark- and gluon-initiated jets. These observables are sensitive to the distributions of transverse momenta and angular distances within a jet. The analysis is performed using a data sample of dijet events enriched in gluon-initiated jets, and, for the first time, a Z+jet event sample enriched in quark-initiated jets. The observables are measured in bins of jet transverse momentum, and as a function of the jet radius parameter. Each measurement is repeated applying a “soft drop” grooming procedure that removes soft and large angle radiation from the jet. Using these measurements, the ability of various models to describe jet substructure is assessed, showing a clear need for improvements in Monte Carlo generators

Risk factors for unfavourable postoperative outcome in patients with Crohn's disease undergoing right hemicolectomy or ileocaecal resection. An international audit by ESCP and S-ECCO

Aim: Patient- and disease-related factors, as well as operation technique, all have the potential to impact on postoperative outcome in Crohn's disease. The available evidence is based on small series and often displays conflicting results. The aim was to investigate the effect of preoperative and intra-operative risk factors on 30-day postoperative outcome in patients undergoing surgery for Crohn's disease. Method: This was an international prospective snapshot audit including consecutive patients undergoing right hemicolectomy or ileocaecal resection. The study analysed a subset of patients who underwent surgery for Crohn's disease. The primary outcome measure was the overall Clavien\u2013Dindo postoperative complication rate. The key secondary outcomes were anastomotic leak, reoperation, surgical site infection and length of stay in hospital. Multivariable binary logistic regression analyses were used to produce odds ratios and 95% confidence intervals. Results: In all, 375 resections in 375 patients were included. The median age was 37 and 57.1% were women. In multivariate analyses, postoperative complications were associated with preoperative parenteral nutrition (OR 2.36, 95% CI 1.10\u20134.97), urgent/expedited surgical intervention (OR 2.00, 95% CI 1.13\u20133.55) and unplanned intra-operative adverse events (OR 2.30, 95% CI 1.20\u20134.45). The postoperative length of stay in hospital was prolonged in patients who received preoperative parenteral nutrition (OR 31, 95% CI 1.08\u20131.61) and those who had urgent/expedited operations (OR 1.21, 95% CI 1.07\u20131.37). Conclusion: Preoperative parenteral nutritional support, urgent/expedited operation and unplanned intra-operative adverse events were associated with unfavourable postoperative outcome. Enhanced preoperative optimization and improved planning of operation pathways and timings may improve outcomes for patients

Outcomes from elective colorectal cancer surgery during the SARS‐CoV‐2 pandemic

Aim This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic. Method This was an international cohort study of patients undergoing elective resection of colon or rectal cancer without preoperative suspicion of SARS-CoV-2. Centres entered data from their first recorded case of COVID-19 until 19 April 2020. The primary outcome was 30-day mortality. Secondary outcomes included anastomotic leak, postoperative SARS-CoV-2 and a comparison with prepandemic European Society of Coloproctology cohort data. Results From 2073 patients in 40 countries, 1.3% (27/2073) had a defunctioning stoma and 3.0% (63/2073) had an end stoma instead of an anastomosis only. Thirty-day mortality was 1.8% (38/2073), the incidence of postoperative SARS-CoV-2 was 3.8% (78/2073) and the anastomotic leak rate was 4.9% (86/1738). Mortality was lowest in patients without a leak or SARS-CoV-2 (14/1601, 0.9%) and highest in patients with both a leak and SARS-CoV-2 (5/13, 38.5%). Mortality was independently associated with anastomotic leak (adjusted odds ratio 6.01, 95% confidence interval 2.58–14.06), postoperative SARS-CoV-2 (16.90, 7.86–36.38), male sex (2.46, 1.01–5.93), age >70 years (2.87, 1.32–6.20) and advanced cancer stage (3.43, 1.16–10.21). Compared with prepandemic data, there were fewer anastomotic leaks (4.9% versus 7.7%) and an overall shorter length of stay (6 versus 7 days) but higher mortality (1.7% versus 1.1%). Conclusion Surgeons need to further mitigate against both SARS-CoV-2 and anastomotic leak when offering surgery during current and future COVID-19 waves based on patient, operative and organizational risks