Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

Peer reviewe

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Measurement of the Higgs boson production rate in association with top quarks in final states with electrons, muons, and hadronically decaying tau leptons at s√=13TeV

The rate for Higgs (H) bosons production in association with either one (tH) or two (tt¯H) top quarks is measured in final states containing multiple electrons, muons, or tau leptons decaying to hadrons and a neutrino, using proton–proton collisions recorded at a center-of-mass energy of 13TeV by the CMS experiment. The analyzed data correspond to an integrated luminosity of 137fb−1. The analysis is aimed at events that contain H→WW, H→ττ, or H→ZZ decays and each of the top quark(s) decays either to lepton+jets or all-jet channels. Sensitivity to signal is maximized by including ten signatures in the analysis, depending on the lepton multiplicity. The separation among tH, tt¯H, and the backgrounds is enhanced through machine-learning techniques and matrix-element methods. The measured production rates for the tt¯H and tH signals correspond to 0.92±0.19(stat)+0.17−0.13(syst) and 5.7±2.7(stat)±3.0(syst) of their respective standard model (SM) expectations. The corresponding observed (expected) significance amounts to 4.7 (5.2) standard deviations for tt¯H, and to 1.4 (0.3) for tH production. Assuming that the Higgs boson coupling to the tau lepton is equal in strength to its expectation in the SM, the coupling yt of the Higgs boson to the top quark divided by its SM expectation, κt=yt/ySMt, is constrained to be within −0.9<κt<−0.7 or 0.7<κt<1.1, at 95% confidence level. This result is the most sensitive measurement of the tt¯H production rate to date.SCOAP

Expresión como proteína recombinante de dos fragmentos de alta unión a células b de la glicoproteina 350 (gp350) del virus de epstein-barr en escherichia coli

El virus de Epstein-Barr (HHV-4) es un herpesvirus con tropismo dirigido exclusivamente a células humanas. Luego de la infección inicial, los viriones producidos durante el ciclo lítico, infectan principalmente células B. Esto se lleva a cabo gracias al reconocimiento inicial de la glicoproteína gp350, la cual se une al receptor CR2 (CD21) de los linfocitos B. En este trabajo se obtuvieron como proteínas recombinantes, tres péptidos identificados como los directamente implicados en el contacto gp350-CR2. En el fragmento denominado VEBI se incluyeron dos péptidos ubicados hacia el extremo N-terminal de gp350, mientras que el fragmento II o VEBII incluye un péptido localizado cerca de la región C-terminal de dicha proteína. La expresión de estos fragmentos se realizó en Escherichia coli y luego de corroborar por secuenciación la integridad de los mismos se identificó la cepa GD1 como la cepa molde que dio lugar a las construcciones plasmídicas. Se obtuvo un 0.6% aproximadamente de proteína pura para VEBI y cerca del 9.4% para VEBII, del total de lisado bacteriano de E. coli. La proteína recombinante obtenida, que incluye los péptidos localizados hacia el extremo N-terminal, puede ser de gran ayuda para diferentes ensayos pues luego de su obtención en E. coli, su conformación estructural podría no diferir mucho de su conformación nativa. Sería necesario realizar más predicciones con la finalidad de demostrar lo anterior para VEBII pues no existe un predictor de glicosilación exclusivo para proteínas virales. Las proteínas recombinantes que incluyen los fragmentos de alta unión a células B, se lograron producir y purificar en buena cantidad, a partir de su expresión en un sistema heterólogo como lo es E. coli.The Epstein-Barr virus (HHV-4) is a herpesvirus with exclusive tropism for human cells. Following an initial infection, virions produced during the lytic replication cycle infect mainly B cells. This is mediated by the initial recognition of the gp350 glycoprotein, which binds to the B lymphocyte CRD receptor (CDD21). In this work, we obtained three peptides identified to be directly implicated in the gp350-CR2 contact as recombinant proteins. The fragment designated as EBVI contained two peptides located towards the gp350 s N-terminal region, while fragment II or EBVII included a peptide localized near the protein s C-terminal region. These fragments were expressed in Escherichia coli and following the verification of their integrity by sequencing, the GD1 strain was identified as the template for plasmid constructs. Approximately 0.6% of pure EBVI and nearly 9.4% of pure EBVII out of the total E. coli protein content were obtained. The recombinant protein harboring the N-terminal peptides can be useful for different assays since its structural conformation might not vary from its native conformation after being isolated from E. co li. More predictions would be necessary to corroborate the latter suggestion for EBVII since a glycosylation predictor exclusive for viral proteins is not available. The recombinant proteins harboring fragments binding with high ability to B cells were produced and purified in good quantities by expressing them in the E. coli heterologous system.Biólogo (a)Pregrad

Caracterización y dinámica de los patrones de infecciones únicas y múltiples para seis tipos del virus de papiloma humano de alto riesgo

El cáncer de cuello uterino (CCU) es la segunda causa de muerte por cáncer en la población femenina de Colombia con tasas de incidencia y mortalidad altas (32,9-36,4 y 18,7 casos/año/100.000 mujeres, respectivamente). El principal factor de riesgo para el desarrollo de lesiones cervicales pre-neoplásicas es la infección persistente por ciertos tipos de Virus de Papiloma Humano (VPH) conocidos como de alto riesgo (VPH-AR), asociados con ~90% de CCU a nivel mundial. \ud Este trabajo tuvo como objetivo identificar las características de la infección por VPH en una población de mujeres socio-demográficamente heterogénea, que habitan en diferentes regiones de Colombia. Para esto, fueron incluidas 2109 mujeres provenientes de las ciudades de Chaparral, Tumaco, Leticia, Bogotá y Girardot, quienes acudieron a los programas de promoción y prevención de CCU implementados en los respectivos hospitales; cada mujer proporcionó información sociodemográfica y de conductas sexuales, además de una muestra de raspado cervical.\ud Se determinó la presencia de VPH por la técnica de PCR, empleando tres juegos de cebadores genéricos, adicionalmente, se usaron cebadores tipo-específicos para determinar la frecuencia de seis tipos de VPH de alto riesgo (VPH-AR-16, -18, -31, -33, -45 y -58) y dos de bajo riesgo (VPH-BR-6/11). Se evaluó también la carga viral de los tipos de VPH-AR mediante PCR en tiempo real y se correlacionaron los datos de 219 mujeres a través de un seguimiento a dos años (cada 6 meses), con el fin de determinar la dinámica de los patrones de infecciones únicas y múltiples encontrados en nuestro país.Cervical cancer (CC) have been reported and continues being the second cause of cancer-related death in Colombia’s female population, with high incidence (32.9-36.4 cases/year/100,000 women) and mortality rates (18.7 cases/year/100,000 women). The main risk factor for developing pre-neoplastic cervical lesions is persistent infection by certain types of human papilloma virus (HPV), known as high risk types (HR-HPV), associated with ~90% of CC around the world. \ud The present work was aimed at identifying HPV infection characteristics in a socio-demographically heterogeneous population of females living in different parts of Colombia; 2,109 women from the cities of Chaparral, Tumaco, Leticia, Bogotá and Girardot were thus included in the study as they were attending CC prevention programmes in their respective hospitals. Every female provided sociodemographic information, data regarding their sexual conduct and a cervical smear.\ud HPV infection was determined by polymerase chain reaction (PCR) using three sets of generic primers; type-specific primers were also used for determining the frequency of six high-risk HPV types (HR-HPV-16, -18, -31, -33, -45 and -58) and two low-risk types (LR-HPV-6/-11). Additionally viral load was evaluated in cervical tissue samples taken from 219 HPV infected females who were seen during a minimum of 4 visits (6 month intervals: + 3 months). Quantitation was performed by real-time PCR (RT-PCR) and the data was correlated by follow-up lasting two years for determining the dynamics of the single and multiple infection patterns found in Colombia

The prevalence of high-risk HPV types and factors determining infection in female colombian adolescents

ColombiaThis study reports six HR-HPV types' infection prevalence discriminated by species and multiple infection in unvaccinated Colombian female adolescents, as well as some factors modulating the risk of infection. HPV DNA for six high-risk viral types was identified in cervical samples taken from 2,134 12-19 year-old females using conventional generic and typespecific PCR. Binomial logistical regression analysis was used for modelling HR-HPV infection and multiple infection risk. The interaction between variables in a stepwise model was also included in such analysis. Viral DNA was detected in 48.97% of the females; 28.52% of them had multiple infections, HPV-16 being the most frequently occurring type (37.44%). Cytological abnormality prevalence was 15.61%. Being over 16 years-old (1.66: 1.01-2.71 95%CI), white ethnicity (4.40: 1.16-16.73 95%CI), having had 3 or more sexual partners (1.77: 1.11-2.81 95%CI) and prior sexually-transmitted infections (STI) (1.65: 1.17-2.32 95%CI) were associated with a greater risk of HPV infection. Having given birth was related to a higher risk of infection by A7 species and antecedent of abortion to less risk of coinfection. Where the females in this study came from also influenced the risk of infection by A7 species as female adolescents from the Andean region had a lower risk of infection (0.42: 0.18-0.99 95%CI). The presence of factors related to risky sexual behaviour in the study population indicated that public health services should pay special attention to female adolescents to modify the risk of infection by high-risk HPV types and decrease their impact on this age group

The prevalence of high-risk HPV types and factors determining infection in female colombian adolescents

This study reports six HR-HPV types' infection prevalence discriminated by species and multiple infection in unvaccinated Colombian female adolescents, as well as some factors modulating the risk of infection. HPV DNA for six high-risk viral types was identified in cervical samples taken from 2,134 12-19 year-old females using conventional generic and typespecific PCR. Binomial logistical regression analysis was used for modelling HR-HPV infection and multiple infection risk. The interaction between variables in a stepwise model was also included in such analysis. Viral DNA was detected in 48.97% of the females; 28.52% of them had multiple infections, HPV-16 being the most frequently occurring type (37.44%). Cytological abnormality prevalence was 15.61%. Being over 16 years-old (1.66: 1.01-2.71 95%CI), white ethnicity (4.40: 1.16-16.73 95%CI), having had 3 or more sexual partners (1.77: 1.11-2.81 95%CI) and prior sexually-transmitted infections (STI) (1.65: 1.17-2.32 95%CI) were associated with a greater risk of HPV infection. Having given birth was related to a higher risk of infection by A7 species and antecedent of abortion to less risk of coinfection. Where the females in this study came from also influenced the risk of infection by A7 species as female adolescents from the Andean region had a lower risk of infection (0.42: 0.18-0.99 95%CI). The presence of factors related to risky sexual behaviour in the study population indicated that public health services should pay special attention to female adolescents to modify the risk of infection by high-risk HPV types and decrease their impact on this age group. © 2016 Del Río-Ospina 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 credited

Association of HIV status with infection by multiple HPV types

Objectives: To identify the clinical and demographic characteristics of HIV-positive and HIV-negative women infected by multiple HPV types. Methods: 1399 women participated in the study (240 HIV-positive and 1159 HIV-negative women). Samples were provided for Pap tests and for HPV detection and typing by PCR. Data were collected on HPV infection, frequency of multiple infection, and HPV type distribution. Odds ratios were reported from logistic regression models. Results: Compared with HIV-negative women, HIV-positive women had higher frequencies of cervical abnormality (30% vs. 20.8%), higher HPV prevalence (68.3% vs. 51.3%) and were more commonly infected with multiple HPV types (78.7% vs. 44.3%). HPV-16 was the most common type detected in the study population, with other types showing variable associations with HIV status. Positive associations were observed between infection by multiple HPV types and HIV status, cervical abnormality and having had more than three pregnancies. The odds of multiple infection by HPV types were higher in HIV-positive women who used an intrauterine device, who had a history of abortions and who had HIV viral loads and gt;100 000 copies/ml, whilst the odds were lower in women with and gt;500 CD4 cells/mm 3 . Conclusions: HIV immunosuppression favours infection by multiple high-risk HPV types, mainly in women affected by low-grade squamous intraepithelial lesions. Antiretroviral therapy had no effect on infection by multiple HPV types. Risk factors related to progressive damage to the cervix were positively associated with infection by multiple HPV types in women living with HIV. © 2018 John Wiley and Sons Lt