Biomass yield, quality and acceptability of selected grass-legume mixtures in the moist savanna of West Africa

In order to identify options suitable for providing livestock feed in the wetter part of the moist savanna, the DM yield, botanical composition, crude protein, in sacco digestibility and neutral detergent fibre of combinations of 4 herbaceous legumes and 2 grasses were evaluated between June 1994 and December 1995 at Ibadan, south-western Nigeria. The legumes, Stylosanthes guianensis, Aeschynomene histrix, Centrosema pubescens and Chamaecrista rotundifolia, were each planted in combination with Brachiaria ruziziensis and Cynodon nlemfuensis. Beginning from one year after planting, the mixtures were mob-grazed 4 times at 8-weekly intervals following DM yield estimation

COVID-19 post-vaccination in healthcare workers and vaccine effectiveness, Brazil, 2021

Objects: This study aimed to describe COVID-19 cases in healthcare workers at a large tertiary hospital, after a vaccination campaign, to understand the individual characteristics, timeliness, symptomatology, and severity of the conditions. Methods: The COVID-19 reporting files from the hospital's healthcare workers and their records in the vaccine registry were analyzed, regarding vaccination status, symptoms, sociodemographic characteristics, comorbidities, and outcomes. Vaccination descriptive analysis was carried out and the impact and effectiveness of vaccination in relation to symptomatic infection and hospitalization were estimated. Results: In a total of 696 PCR-confirmed COVID-19 patients, vaccination coverage for the 1st and 2nd dose was 92.8% and 85.5%. Patients with complete doses had a mean interval of 96.8 days between vaccination and the onset of symptoms. Of the 664 participants with available clinical data, 165 had at least 1 comorbidity. During the study, 12 patients were hospitalized, 58.3% with a complete vaccination schedule. Three of this group died. The effectiveness of vaccination for symptomatic cases and hospitalization was 22.1% and 69.0%, respectively. The impact of vaccination on symptomatic cases and hospitalization was 81.4% and 89.7%, respectively. Discussion: The majority of COVID-19 cases in the study were classified as mild. The impact of vaccination for confirmed cases was significant, both in reducing the incidence of symptomatic cases and hospitalizations. The presence of comorbidities in approximately ¼ of the patients increased the risk of these individuals. The mean time interval between diagnosis and the 2nd dose of vaccine was longer in the hospitalized group, reinforcing the protective decline over longer periods

Microstructure and thermal stability of Fe, Ti and Ag implanted Yttria-stabilized zirconia

Yttria-stabilized zirconia (YSZ) was implanted with 15 keV Fe or Ti ions up to a dose of 8×1016 at cm−2. The resulting “dopant” concentrations exceeded the concentrations corresponding to the equilibrium solid solubility of Fe2O3 or TiO2 in YSZ. During oxidation in air at 400° C, the Fe and Ti concentration in the outermost surface layer increased even further until a surface layer was formed of mainly Fe2O3 and TiO2, as shown by XPS and ISS measurements. From the time dependence of the Fe and Ti depth profiles during anneal treatments, diffusion coefficients were calculated. From those values it was estimated that the maximum temperature at which the Fe- and Ti-implanted layers can be operated without changes in the dopant concentration profiles was 700 and 800° C, respectively. The high-dose implanted layer was completely amorphous even after annealing up to 1100° C, as shown by scanning transmission electron microscopy. Preliminary measurements on 50 keV Ag implanted YSZ indicate that in this case the amorphous layer recrystallizes into fine grained cubic YSZ at a temperature of about 1000° C. The average grain diameter was estimated at 20 nm, whereas the original grain size of YSZ before implantation was 400 nm. This result implies that the grain size in the surface of a ceramic material can be decreased by ion beam amorphisation and subsequent recrystallisation at elevated temperatures

Chile's export diversification since 1960: A free market miracle or mirage?

Conventional wisdom has proclaimed Chile's recent economic development a 'free market miracle'. In an examination of Chile's export diversification experience, this article departs from that view. By analysing the dynamics underlying the emergence of the salmon, fruit, forestry and wine sectors in Chile's export basket since the 1960s, the study sheds light on the crucial role of industrial policy in the process of capability accumulation that shapes new industries. The article undertakes a qualitative historical analysis of the scope and nature of policy interventions in each of the four sectors and conducts a quantitative policy evaluation using the difference-in-difference method. It finds that public institutions are essential in overcoming market failures inhibiting the emergence of new industries. Specifically, it shows that the government has a key role to play as a catalyst of human capital accumulation, as a venture capitalist, in trade promotion, and in ensuring 'national' sector reputation through a strong regulatory and quality control role. By elaborating on the dynamic process of structural transformation and capability accumulation, this article contributes to theoretical debates on the role of vertical policies in the emergence of new competitive sectors, and debates relating to static versus dynamic approaches to comparative advantage

Machine learning algorithms performed no better than regression models for prognostication in traumatic brain injury

Objective: We aimed to explore the added value of common machine learning (ML) algorithms for prediction of outcome for moderate and severe traumatic brain injury. Study Design and Setting: We performed logistic regression (LR), lasso regression, and ridge regression with key baseline predictors in the IMPACT-II database (15 studies, n = 11,022). ML algorithms included support vector machines, random forests, gradient boosting machines, and artificial neural networks and were trained using the same predictors. To assess generalizability of predictions, we performed internal, internal-external, and external validation on the recent CENTER-TBI study (patients with Glasgow Coma Scale <13, n = 1,554). Both calibration (calibration slope/intercept) and discrimination (area under the curve) was quantified. Results: In the IMPACT-II database, 3,332/11,022 (30%) died and 5,233(48%) had unfavorable outcome (Glasgow Outcome Scale less than 4). In the CENTER-TBI study, 348/1,554(29%) died and 651(54%) had unfavorable outcome. Discrimination and calibration varied widely between the studies and less so between the studied algorithms. The mean area under the curve was 0.82 for mortality and 0.77 for unfavorable outcomes in the CENTER-TBI study. Conclusion: ML algorithms may not outperform traditional regression approaches in a low-dimensional setting for outcome prediction after moderate or severe traumatic brain injury. Similar to regression-based prediction models, ML algorithms should be rigorously validated to ensure applicability to new populations

A spitzer survey of deep drilling fields to be targeted by the Vera C. Rubin observatory legacy survey of space and time

The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) will observe several Deep Drilling Fields (DDFs) to a greater depth and with a more rapid cadence than the main survey. In this paper, we describe the 'DeepDrill' survey, which used the Spitzer Space Telescope Infrared Array Camera (IRAC) to observe three of the four currently defined DDFs in two bands, centred on 3.6 and 4.5 μm. These observations expand the area that was covered by an earlier set of observations in these three fields by the Spitzer Extragalactic Representative Volume Survey (SERVS). The combined DeepDrill and SERVS data cover the footprints of the LSST DDFs in the Extended Chandra Deep Field-South (ECDFS) field, the ELAIS-S1 field (ES1), and the XMM-Large-Scale Structure Survey field (XMM-LSS). The observations reach an approximate 5σ point-source depth of 2 μJy (corresponding to an AB magnitude of 23.1; sufficient to detect a 1011 M⊙ galaxy out to z ≈ 5) in each of the two bands over a total area of ≈ 29 deg2. The dual-band catalogues contain a total of 2.35 million sources