Extracting the Weinberg angle at intermediate energies

A recent experiment by the NuTeV collaboration resulted in a surprisingly high value for the weak mixing angle $\sin^2 \theta_W$. The Paschos-Wolfenstein relation, relating neutrino cross sections to the Weinberg angle, is of pivotal importance in the NuTeV analysis. In this work, we investigate the sensitivity of the Paschos-Wolfenstein relation to nuclear structure aspects at neutrino energies in the few GeV range. Neutrino-nucleus cross sections are calculated for $^{16}$O and $^{56}$Fe target nuclei within a relativistic quasi-elastic nucleon-knockout model.Comment: To appear in the proceedings of International School of Nuclear Physics: 27th Course: "Neutrinos in Cosmology, in Astro, Particle and Nuclear Physics", Erice, Sicily, Italy, 16-24 Sep 200

Strangeness content of the nucleon in quasielastic neutrino-nucleus reactions

We present a systematic study of the sensitivity of quasielastic neutrino-nucleus cross sections at intermediate energies to the strange quark sea of the nucleon. To this end, we investigate the impact of the weak strangeness form factors on the ratio of proton-to-neutron knockout, the ratio of neutral-to-charged current cross sections, on the Paschos-Wolfenstein relation, and on the longitudinal helicity asymmetry. The influence of axial as well as vector strangeness effects is discussed. For the latter, we introduce strangeness parameters from various hadron models and from a recent fit to data from parity violating electron scattering. In our model, the nuclear target is described in terms of a relativistic mean-field approach. The effects of final-state interactions on the outgoing nucleon are quantified within a relativistic multiple-scattering Glauber approach. Our results are illustrated with cross sections for the scattering of 1 GeV neutrinos and antineutrinos off a $^{12}$C target. Folding with a proposed FINeSSE (anti)neutrino energy-distribution has no qualitative influence on the overall sensitivity of the cross-section ratios to strangeness mechanisms. We show that vector strangeness effects are large and strongly $Q^2$ dependent.Comment: 25 pages, 12 figures, submitted to Phys. Rev.

Helicity asymmetries in neutrino-nucleus interactions

We investigate the helicity properties of the ejectile in quasi-elastic neutrino-induced nucleon-knockout reactions and consider the 12C target as a test case. A formalism based on a relativistic mean-field model is adopted. The influence of final-state interactions is evaluated within a relativistic multiple-scattering Glauber approximation (RMSGA) model. Our calculations reveal that the helicity asymmetries A_l in A(\overline{\nu},\overline{\nu}'N) processes are extremely sensitive to strange-quark contributions to the weak vector form-factors. Thereby, nuclear corrections, such as final-state interactions and off-shell ambiguities in the electroweak current operators, are observed to be of marginal importance. This facilitates extracting strange-quark information from the helicity asymmetry A_l.Comment: 14 pages, 6 figures, 1 table submitted to PL

Relativistic models for quasi-elastic neutrino scattering

We present quasi-elastic neutrino-nucleus cross sections in the energy range from 150 MeV up to 5 GeV for the target nuclei 12C and 56Fe. A relativistic description of the nuclear dynamics and the neutrino-nucleus coupling is adopted. For the treatment of final-state interactions (FSI) we rely on two frameworks succesfully applied to exclusive electron-nucleus scattering: a relativistic optical potential and a relativistic multiple-scattering Glauber approximation. At lower energies, the optical-potential approach is considered to be the optimum choice, whereas at high energies a Glauber approach is more natural. Comparing the results of both calculations, it is found that the Glauber approach yields valid results down to the remarkably small nucleon kinetic energies of 200 MeV. We argue that the nuclear transparencies extracted from A(e,e'p) measurements can be used to obtain realistic estimates of the effect of FSI mechanisms on quasi-elastic neutrino-nucleus cross sections. We present two independent relativistic plane-wave impulse approximation (RPWIA) calculations of quasi-elastic neutrino-nucleus cross sections. They agree at the percent level, showing the reliability of the numerical techniques adopted and providing benchmark RPWIA results.Comment: revised version,28 pages, 7 figures, accepted in Phys.Rev.

Yam improvement for income and food security in West Africa: Effectiveness of a multi-disciplinary and multi-institutional team-work

The overall goal of the five year project “Yam Improvement for Income and Food Security in West Africa” (YIIFSWA) funded by the Bill and Melinda Gates Foundation and led by the International Institute of Tropical Agriculture, Ibadan, Nigeria was to: (a) increase yam productivity by 40% for 2,00,000 smallholder yam farmers in Ghana and Nigeria and (b) deliver key global good research products that will contribute to the 10-year overall vision to sustainably double incomes from yams for 3 million smallholder yam farming families and contribute to ensuring food security for producers and consumers. Implemented by scientists of twenty partner specialized organizations, comprising research institutes, Universities, governmental and non-governmental organizations, YIIFSWA has impacted yam value chain stakeholders through research and development interventions. The significant contributions made in the project during the past 18 months’ period are discussed in this paper. These include: a baseline survey conducted in key yam growing areas in Ghana and Nigeria, training of yam producers on adapted yam minisett technique and production of seed yam, undertaking in depth value chain assessments, developing the capacity of Farmers Organizations (FOs) by linking them to service providers (SPs), participatory evaluation of new yam genotypes, successful development of yam virus diseases diagnostics and development of novel techniques for high ratio yam propagation such as aeroponics and bioreactors

Transforming yam seed systems in west Africa

The availability of clean planting materials and functional seed regulatory systems is indispensable for fostering a sustainable seed yam system. The Yam Improvement for Income and Food Security in West Africa (YIIFSWA) project of the International Institute of Tropical Agriculture (IITA) developed the capacity of National Agricultural Research Institutes (NARIs) in their use of standardized Temporary Immersion Bioreactor (TIB) and Vivipak (VP) systems for high-ratio propagation and post-flask handling of yam breeder seed plantlets. Foundation seed was enhanced by supporting five private seed companies in Nigeria and three in Ghana. They were equipped with aeroponic and hydroponic technologies for foundation seed tuber production using single-node vine seedlings. For certified seed, seed yam out-growers were trained in good agronomic practices and entrepreneurship for certified seed tuber production using the adaptive yam minisett technique (AYMT). New certification standards were established for various classes of seed produced using different propagation methods and quality assurance procedures in Ghana and Nigeria. The capacity of the national regulatory organizations in both countries was enhanced to implement seed quality control and certification. Increased public sensitization and advocacy were done to raise awareness among relevant stakeholders to enhance the uptake of the seed propagation technologies and ensure a smooth interaction between the public and private sectors. This chapter summarizes the accomplishments of YIIFSWA in Ghana and Nigeria and the spillover impact on the yam belt of West Africa and beyond. The key lessons could inform the design and implementation of more effective seed projects, especially for vegetatively propagated crops

Obesity, inflammatory and thrombotic markers, and major clinical outcomes in critically ill patients with COVID‐19 in the US

OBJECTIVE: This study aimed to determine whether obesity is independently associated with major adverse clinical outcomes and inflammatory and thrombotic markers in critically ill patients with COVID-19. METHODS: The primary outcome was in-hospital mortality in adults with COVID-19 admitted to intensive care units across the US. Secondary outcomes were acute respiratory distress syndrome (ARDS), acute kidney injury requiring renal replacement therapy (AKI-RRT), thrombotic events, and seven blood markers of inflammation and thrombosis. Unadjusted and multivariable-adjusted models were used. RESULTS: Among the 4,908 study patients, mean (SD) age was 60.9 (14.7) years, 3,095 (62.8%) were male, and 2,552 (52.0%) had obesity. In multivariable models, BMI was not associated with mortality. Higher BMI beginning at 25 kg/m2 was associated with a greater risk of ARDS and AKI-RRT but not thrombosis. There was no clinically significant association between BMI and inflammatory or thrombotic markers. CONCLUSIONS: In critically ill patients with COVID-19, higher BMI was not associated with death or thrombotic events but was associated with a greater risk of ARDS and AKI-RRT. The lack of an association between BMI and circulating biomarkers calls into question the paradigm that obesity contributes to poor outcomes in critically ill patients with COVID-19 by upregulating systemic inflammatory and prothrombotic pathways

National Instant Criminal Background Check and Youth Gun Carrying

Background: Despite being unable to purchase firearms directly, many adolescents have access to guns, leading to increased risk of injury and death. We sought to determine if the National Instant Criminal Background Check System (NICS) changed adolescents' gun-carrying behavior. Methods: We performed a repeated cross-sectional study using National Youth Risk Behavior Survey data from years 1993 to 2017. We used a survey-weighted multivariable logistic regression model to determine if the NICS had an effect on adolescent gun carrying, controlling for state respondent characteristics, state laws, state characteristics, the interaction between the NICS and state gun laws, and time. Results: On average, 5.8% of the cohort reported carrying a gun. Approximately 17% of respondents who carried guns were from states with a universal background check (U/BC) provision at the point of sale, whereas 83% were from states that did not have such laws (P < .001). The model indicated that the NICS together with U/BCs significantly reduced gun carrying by 25% (adjusted relative risk = 0.75 [95% confidence interval: 0.566-0.995]; P = .046), whereas the NICS independently did not (P = .516). Conclusions: Adolescents in states that require U/BCs on all prospective gun buyers are less likely to carry guns compared with those in states that only require background checks on sales through federally licensed firearms dealers. The NICS was only effective in reducing adolescent gun carrying in the presence of state laws requiring U/BCs on all prospective gun buyers. However, state U/BC laws had no effect on adolescent gun carrying until after the NICS was implemented

Adolescent male with anorexia nervosa: a case report from Iraq

This is the first reported case of an adolescent male with anorexia nervosa in Iraq. This disorder is believed to be rare in males across cultures and uncommon for both genders in Arab countries. The patient met the DSM-IV diagnostic criteria for anorexia nervosa. He was hospitalized and received medical and psychiatric treatment at local facilities as discussed below and responded well to treatment