Presented herein is the integral valorization of residual biomass to film composites by their fractionation into building blocks in a multicomponent cascade isolation approach. First, pine cones were ...subjected to alkaline pretreatment, followed by soda pulping. Two different hemicellulose/lignin-based fractions were recovered from the extractives of these treatments, with a yield of 19%. Then, chloride- and peroxide-based bleaching methods were proposed to treat the soda-pulped samples, obtaining two cellulose-rich fractions with different chemical compositions and recovery yields (32% and 44%, respectively). From these cellulose fractions, two types of nanocelluloses with different lignin contents were obtained: cellulose nanofibrils (CNF), with a lignin content of 1%, and lignocellulose nanofibrils (LCNF), with a lignin content of 16%. The LCNF displayed lower crystallinity and viscosity but greater diameter and thermal stability than the CNF. The reinforcing capability of different amounts of both nanocelluloses on the first hemicellulose/lignin-based fraction (PCA-L) to form films was evaluated. The thermomechanical, barrier, antioxidant, moisture sorption, and mechanical properties were assessed and compared. In general, the LCNF films showed less moisture sorption and better thermomechanical and antioxidant properties than the CNF films. These results reveal LCNF to be a promising reinforcing agent for designing all-lignocellulose-based composite films to be used in food packaging applications.
Computational thinking (CT) is a key skill in the 21st century. However, it is not clear which is the most effective way to acquire and improve CT. Big research efforts are made to determine which ...pedagogical means should be used. One research trend is based on the idea that teaching programming since Primary Education suffices to improve CT. In our previous work, we proposed and validated a methodology based on metaphors and used of Scratch (MECOPROG) to teach basic programming concepts to children. It is our hypothesis H that by applying MECOPROG, students will develop their CT. To check H, we carried out an experiment with 132 Primary Education Students (9–12 years in age). At the beginning of the experiment, all students were asked to fill in a programming concepts test and two tests to measure their CT. During the sessions, all students were taught according to MECOPROG. Finally, they took the three tests again. A significant increase in the results on all the tests has been measured, supporting the use of metaphors and Scratch to teach computer programming concepts to Primary Education students to develop their CT.
•Computational Thinking can be improved using metaphors and Scratch.•Primary Education students' Computational Thinking can be improved.•Primary Education students can learn basic programming concepts.
Contribution: A methodology based on the learning by teaching approach facilitated by a mobile learning tool for creating tutorials. A study of the impact this methodology has had on the emotional ...well-being of students and its correlation with academic performance has also been carried out.
Background: Insufficient resources and the absence of targeted teaching methods for technical content in vocational training may impact academic outcomes and lead to student demotivation. Previous studies indicate that employing active group methodologies contributes to the improvement of educational quality and positively influences the emotional well-being of students.
Intended Outcomes: Improved academic performance, motivation levels, and collaborative work among peers, particularly within vocational training cycles.
Application Design: A quasi-experimental design with a pre-post assessment of knowledge and emotional states. The study was carried out with 131 vocational training students, with one group following a conventional master class methodology that used practical activities, and another group following the learning by teaching methodology, where students created explanatory tutorials for their peers using a mobile application.
Findings: Students who followed the proposed methodology significantly improved learning results compared to those who followed the traditional methodology. This improvement was evident both at the end of the experience and in the final evaluation of the course. Moreover, results revealed that the emotions of enjoyment and pride at the end of the learning process positively correlated with the acquisition of knowledge and that this correlation was more pronounced within the cohort that followed the learning by teaching methodology.
The risk of progression to tuberculosis disease is highest within the first year after
infection (TBI). We hypothesize that people with newly acquired TBI have a unique cytokine/chemokine profile ...that could be used as a potential biomarker.
We evaluated socio-demographic variables and 18 cytokines/chemokines in plasma samples from a cohort of people deprived of liberty (PDL) in two Colombian prisons: 47 people diagnosed with pulmonary TB, 24 with new TBI, and 47 non-infected individuals. We performed a multinomial regression to identify the immune parameters that differentiate the groups.
The concentration of immune parameters changed over time and was affected by the time of incarceration. The concentration of sCD14, IL-18 and IP-10 differed between individuals with new TBI and short and long times of incarceration. Among people with short incarceration, high concentrations of MIP-3α were associated with a higher risk of a new TBI, and higher concentrations of Eotaxin were associated with a lower risk of a new TBI. Higher concentrations of sCD14 and TNF-α were associated with a higher risk of TB disease, and higher concentrations of IL-18 and MCP-1 were associated with a lower risk of TB disease.
There were cytokines/chemokines associated with new TBI and TB disease. However, the concentration of immune mediators varies by the time of incarceration among people with new TBI. Further studies should evaluate the changes of these and other cytokines/chemokines over time to understand the immune mechanisms across the spectrum of TB.
People deprived of liberty (PDL) are at high risk of acquiring Mycobacterium tuberculosis infection (latent tuberculosis infection LTBI) and progressing to active tuberculosis (TB). We sought to ...determine the incidence rates and factors associated with LTBI and active TB in Colombian prisons. Using information of four cohort studies, we included 240 PDL with two-step tuberculin skin test (TST) negative and followed them to evaluate TST conversion, as well as, 2,134 PDL that were investigated to rule out active TB (1,305 among people with lower respiratory symptoms of any duration, and 829 among people without respiratory symptoms and screened for LTBI). Latent tuberculosis infection incidence rate was 2,402.88 cases per 100,000 person-months (95% CI 1,364.62-4,231.10) in PDL with short incarceration at baseline, and 419.66 cases per 100,000 person-months (95% CI 225.80-779.95) in individuals with long incarceration at baseline (who were enrolled for the follow after at least 1 year of incarceration). The TB incidence rate among PDL with lower respiratory symptoms was 146.53 cases/100,000 person-months, and among PDL without respiratory symptoms screened for LTBI the incidence rate was 19.49 cases/100,000 person-months. History of Bacillus Calmette-Guerin vaccination decreased the risk of acquiring LTBI among PDL who were recently incarcerated. Female sex, smoked drugs, and current cigarette smoking were associated with an increased risk of developing active TB. This study shows that PDL have high risk for LTBI and active TB. It is important to perform LTBI testing at admission to prison, as well as regular follow-up to control TB in prisons.
In this paper we address an open key issue during the development of web-based educational systems. In particular, we provide an educational-oriented approach for building personalised e-learning ...environments that focuses on putting the learners' needs in the centre of the development process. Our approach proposes user centred design methodologies involving interdisciplinary teams of software developers and domain experts. It is illustrated in an adaptive e-learning system, where a MOOC (Massive Open Online Course) was taken by nearly 400 learners. In particular, we report where user centred design methods can be applied along the e-learning life cycle to designing and evaluating personalisation support through recommendations in learning management systems.
•User centred design translates educators' expertise to the adaptation process.•Adaptation support can be managed along the e-learning life cycle.•Recommendations can enrich LMS with adaptive navigation support.•Learning outcomes in MOOC improve with user centred recommendations.
This work seeks to synthesise the knowledge on the use of cover crops in vineyards in the last 20 years, emphasising on the one hand, soil characteristics such as nutrition, organic carbon, structure ...or erosion and, on the other hand, environmental factors such as soil and biodiversity in vineyards, and gas emissions.A systematic review was made using Scopus-index journals for the past 20 years (1999 - 2018). The selection was independently done by two researchers, selecting a total of 272 published papers related to cover crops in the vineyard. Each article was categorised according to its theme and metadata were created, considering all relevant information from an agro-ecological point of view.The use of cover crops has a positive effect on the vineyard by increasing soil organic carbon (SOC), improving water infiltration and aggregate stability, and reducing erosion and greenhouse gases emission to the atmosphere. Furthermore, there is an increase in biodiversity, both in soil and the vineyard. Finally, cover crops do not constitute as a rule a major competition for nutrients to the vines except for nitrogen when grass covers are used. Contrarily, legume cover crops generally increase N in the soil, although its availability for plants is not immediate.This review constitutes an objective tool to help growers when considering the use of cover crops in vineyards that, based in a systematic review, provides relevant information depending on the characteristics of the growing condition of the vineyard.
The selection of genotypes best adapted to environmental conditions has traditionally focused on agronomic and grape composition parameters. However, to classify the genotypes most adapted to climate ...change conditions, the aim must be to focus on the ecophysiological responses that will ultimately determine their performance. The variability in water use efficiency of 13 Grenache genotypes over three‐seasons was assessed under field conditions at leaf, grape and plant level. Results showed a significant effect of genotype at all three levels, and despite the large interannual variability there was a remarkable consistency among levels. Furthermore, using genotype‐specific regressions it was possible to identify significant differences in the intrinsic water use efficiency response of each genotype as a function of the vine water status. The relationship between net photosynthesis and stomatal conductance, as well as carbon isotope discrimination in grapes, were also confirmed as reliable physiological indicators for selecting grapevine genotypes to future environmental conditions. Therefore, the proposed multi‐level methodology was useful to quantify the intracultivar variability and the identification of more and less efficient genotypes within Grenache.
The present systematic review aims to provide an overview of the impact of cover crops on vegetative growth and the productive parameters of vineyards.A systematic review was made on Scopus-index ...journals dating from 1999 to 2018. The selection was made at the same time by two different researchers, who selected a total of 272 published papers related to cover crops in vineyards. Each article was categorised according to its theme and a metadata database was created, considering all relevant information from an agronomic point of view for each article.It can be concluded from the review that the use of cover crops can reduce vine vegetative growth, which in turn can help keep the incidence of fungal diseases (like grey mould) at a low level. In general, this practice does not have a clear effect on vineyard yield or grape juice parameters, like total soluble solids (TSS) or titratable acidity (TA). Cover crops can decrease vineyard pests to a certain extent, especially Cicadellidae. Cover crops can sometimes sporadically cause water stress in the vineyard, but only during the summer months.This review allowed us to summarise available information on cover crops and their effects on vineyard agronomic performance in a systematic way. Such information can be used to help select the most suitable cover, based on specific vineyard objectives and growing conditions.
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