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A partir de 2022 en nuestro país, se retorna a la normalidad, pero ésta no es exactamente igual a la de la pre pandemia, estableciéndose "una nueva normalidad". La educación debe adecuarse a las nuevas circunstancias y el rol del docente acompaña estos cambios, convirtiéndose en mediador, favoreciendo procesos de formación autogestionados. Es importante que la oferta pedagógica sea acorde a las necesidades, por ello, la finalidad del presente trabajo es compartir una experiencia puntual de modelo híbrido en la Facultad de Ciencias Naturales y Museo de la UNLP. Para saber cómo fue recibido el modelo híbrido se realizó una encuesta a los estudiantes que nos permitió conocer si este modelo mixto fue elegido como primera opción, si están conformes con los encuentros presenciales previos a cada parcial, y las ventajas y desventajas que encuentran en este tipo de cursada. Se recibieron las respuestas del 34% de los estudiantes. El 45% de los mismos se anotaron por propia elección y el 90% está conforme con la metodología. En nuestra experiencia se logró suplementar los inconvenientes respecto al reconocimiento del material práctico, mediante la incorporación del modelo híbrido, agregando clases presenciales que enriquecieron la propuesta pedagógica mediante clases prácticas, de consulta, intercambio y debate., As of 2022 in our country, it returns to normality, but this is not exactly the same as that of the pre-pandemic, establishing "a new normality". Education must adapt to the new circumstances and the role of the teacher accompanies these changes, becoming a mediator, favoring self-managed training processes. It is important that the pedagogical offer is in accordance with the needs, therefore, the purpose of this work is to share a specific experience of a hybrid model in the Faculty of Natural Sciences and Museum of the UNLP. To find out how the hybrid model was received, a survey was carried out among the students, which allowed us to find out if this mixed model was chosen as the first option, if they are satisfied with the face-to-face meetings prior to each partial, and the advantages and disadvantages they find in this type of course Responses from 34% of the students were received. 45% of them were written down by their own choice and 90% are satisfied with the methodology. In our experience, it was possible to supplement the inconveniences regarding the recognition of practical material, by incorporating the hybrid model, adding face-to-face classes that enriched the pedagogical proposal through practical classes, consultation, exchange, and debate., Especialización en Docencia Universitaria

Bilevel optimization, also referred to as bilevel programming, involves solving an upper level problem subject to the optimality of a corresponding lower level problem. The upper and lower level problems are also referred to as the leader and follower problems, respectively. Both levels have their associated objective(s), variable(s) and constraint(s). Such problems model real-life scenarios of cases where the performance of an upper level authority is realizable/sustainable only if the corresponding lower level objective is optimum. A number of practical applications in the field of engineering, logistics, economics and transportation have inherent nested structure that are suited to this type of modelling. The range of applications as well as a rapid increase in the size and complexity of such problems has prompted active interest in the design of efficient algorithms for bilevel optimization. Bilevel optimization problems present a number of unique and interesting challenges to algorithm design. The nested nature of the problem requires optimization of a lower level problem to evaluate each upper level solution, which makes it computationally exorbitant. Theoretically, an upper level solution is considered valid/feasible only if the corresponding lower level variables are the true global optimum of the lower level problem. Global optimality can be reliably asserted in very limited cases, for example convex and linear problems. In deceptive cases, an inaccurate lower level optimum may result in an objective value better than true optimum at the upper level, which poses a severe challenge for ranking/selection strategies used within any optimization technique. In turn, this also makes the performance evaluation very difficult since the performance cannot be judged based on the objective values alone. While the area of bilevel (or more generally, multilevel) programming itself is not very new, most reports in this direction up until about a decade ago considered solving linear or at most quadratic problems at both levels. Correspondingly, the focus on was on development of exact methods to solve such problems. However, such methods typically require assumptions on mathematical properties, which may not always hold in practical applications. With increasing use of computer simulation-based evaluations in a number of disciplines in science and engineering, there is more need than ever to handle problems that are highly nonlinear or even black-box in nature. Metaheuristic algorithms, such as evolutionary algorithms are more suited to this emerging paradigm. The foray of evolutionary algorithms in bilevel programming is relatively recent and there remains scope of substantial development in the field in terms of addressing the aforementioned challenges. The work presented in this thesis is directed towards improving evolutionary techniques to enable them solve generic bilevel problems more accurately using lower number of function evaluations compared to the existing methods. Three key approaches are investigated towards accomplishing this: (a) e active hybridization of global and local search methods during dierent stages of the overall search; (b) use of surrogate models to guide the search using approximations in lieu of true function evaluations, and (c) use of a non-nested re-formulation of the problem. While most of the work is focused on single-objective problems, preliminary studies are also presented on multi-objective bilevel problems. The performance of the proposed approaches is evaluated on a comprehensive suite of mathematical test problems available in the literature, as well as some practical problems. The proposed approaches are observed to achieve a favourable balance between accuracy and computational expense for solving bilevel optimization problems, and thus exhibit suitability for use in real-life applications.

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the intake of iron in the Norwegian population in relation to tolerable upper intake levels (ULs). The existing maximum limit for iron in food supplements is 27 mg/day. VKM has also conducted scenario calculations to illustrate the consequences of amending the maximum limit to 5, 10, 20, 30, 40 or 50 mg/day. Iron deficiency is one of the most common nutritional disorders in the world. Individuals with increased iron demand such as growing children and pregnant women, those who experience blood loss such as menstruating women are particularly at risk for the consequences or iron deficiency. Iron deficiency can lead to fatigue and anaemia. The most common adverse effects of iron supplementation are reversible gastrointestinal symptoms. Chronic iron excess can lead to iron overload which is associated with several irreversible severe health outcomes such as cancers and cardiovascular diseases. Up to 1% of the population have a genetic trait that leads to accumulation of iron and renders them more vulnerable to iron excess. An adult needs approximately 10 mg iron per day to overcome daily loss. The tolerable upper intake level (UL) for iron in adults range from 45 to 60 mg/day. However, all previous reports acknowledge the challenges in defining upper levels. The Expert Group on Vitamins and minerals (EVM), UK report provided a guidance level (GL) of 17 instead of a UL and the Nordic Nutrition Recommendations (NNR) (2012) suggested an UL of 60 mg/day, but did not suggest any clear upper levels for children. Institute of Medicine (IOM), US (2001) gives the most substantiated tolerable upper intake levels based on gastrointestinal effects, which is 40 mg/day for infants and children, regardless of age, and 45 mg/day for adolescents and adults. The Joint FAO/WHO Expert Committee on Food Additives 2003 (JECFA) also took the potential serious effects of iron overload into account and suggested a GL of 50 mg/day in adults or 0.8 mg/kg per day in children and adolescents. Because the risks and consequences from overload are significant and potentially serious, VKM suggests that the GL from JECFA (2003) is used. Using the GL from JECFA (2003), none of the suggested doses can be given to 2 or 4-year-old children, 9 year olds can add 5 mg iron from supplements, 13 year olds 20, and adults 30 mg without exceeding the guidance levels., NO; PDF; vkm@vkm.no

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the risk associated with magnesium in food supplements. VKM is requested to evaluate upper tolerable intake levels for magnesium and high and low intakes in the Norwegian population. Pending establishment of common maximum limits in the EU, the NFSA is evaluating the national maximum limits for vitamins and minerals in food supplements. This risk assessment is the scientific basis for NFSA's evaluation of national limits for magnesium. Directive 2002/46/EC on food supplements was implemented in Norwegian law in 2004 in Regulation 20 May 2004 No. 755 on food supplements. Common maximum and minimum levels of vitamins and minerals in food supplements shall be set in the EU. Until common limits are established in the EU, the national limits apply. The present report is a risk assessment of magnesium in food supplements. It is based on published articles retrieved from literature searches and previous risk assessments of magnesium. Magnesium is an essential alkaline mineral and occurs as free cation Mg2+ in aqueous solution, or as the mineral part of a large variety of compounds such as chlorides, carbonates and hydroxides. Dietary sources of magnesium include green leafy vegetables, legumes, whole grain cereals, dark chocolate, nuts, fish and seafood, banana and coffee. NFSA has especially requested VKM to consider water as a source of magnesium. A few waterworks reported magnesium concentrations at 10 mg/L. Consumption of water from these waterworks may contribute up to 10% of recommended magnesium intake. However, most waterworks reported negligible magnesium concentrations. Magnesium has multiple functions in the body; it is a required cofactor for more than 300 enzyme systems in the body; for energy-dependent membrane transport, for gene regulation, and for sustained electrical potential in excitable cells. Magnesium also plays a major role in bone and mineral homeostasis. No tolerable upper intake level (UL) has been established for magnesium intake from food sources for the reason that no adverse effects have been recognised in healthy populations. Magnesium salts in food supplements may cause osmotic diarrhoea which is the most frequently reported adverse effect. However, these effects are considered relatively mild. Previous reports have arrived on UL or guidance levels (GLs) for supplemental magnesium ranging from 250 mg/day in the EU (Scientific Committee for Food (SCF, 2001)) through 350 mg/day in the USA (Institute of Medicine (IOM, 1997)) and up to 400 mg per day in the UK (Expert group on Vitamins and Minerals (EVM, 2003)). The UL from SCF (2001) is below the recommended daily dietary intakes for adults. Since the critical endpoint (gastrointestinal symptoms) is mild, rapidly reversible and no NOAEL could be identified, VKM finds it appropriate to base the UL for magnesium salts in food supplements on the LOAEL from IOM (1997). For the same reason, an uncertainty factor of 1 may be applicable for establishing a UL for magnesium salts in food supplements. VKM therefore proposes an amendment of the ULs suggested by SCF (2001) for magnesium in supplements. The IOM (1997) suggestion of a UL at 350 mg supplementary magnesium per day for adults was based on a LOAEL for mild diarrhea. VKM found no results to support an alteration of this UL. VKM therefore suggests a UL of 350 mg magnesium in food supplements per day in adults which is in accordance with the UL suggested by (IOM, 1997). This UL will also cover the recommended intakes for the adult population. According to the habitual dietary intakes of magnesium estimated from nationwide dietary surveys in Norway, about 25% of adults have intakes of magnesium below the recommendations from food and supplements. Almost the same percentage was below the recommended intakes among 9-year-old children, while approximately 70% of 13-year-olds had an intake of magnesium below the recommendations. It should be noted that the intakes have been estimated with use of different dietary survey methods for the different age categories and a comparison of estimates across age groups can be misleading and has a high degree of uncertainty. Concentration of magnesium in water is low and about 60% of the waterworks reporting to the Norwegian Waterworks Registry had a magnesium concentration below 2 mg/L, indicating water as a negligible source of magnesium for the majority of the population., NO; PDF; vkm@vkm.no

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the risk associated with magnesium in food supplements. VKM is requested to evaluate upper tolerable intake levels for magnesium and high and low intakes in the Norwegian population. Pending establishment of common maximum limits in the EU, the NFSA is evaluating the national maximum limits for vitamins and minerals in food supplements. This risk assessment is the scientific basis for NFSA's evaluation of national limits for magnesium.

The diploma thesis is focusing on the topic of the ideal teacher and its viewing by students. The thesis is tracking the differences between pupils' perception and the theory basis; there are also described differences between girls and boys and their perception. The goal of the thesis is finding out how students imagine the ideal teacher. The thesis is divided into the theoretical and practical part. The theoretical part deals with the requirements for the teacher's job and then there are competences of teachers that are necessary for this job and are the important for reaching the state of the ideal teacher. The theoretical basis is fundamental for the following comparison with outputs of the practical part of the thesis. The practical part of the thesis presents the data that were gained by the questionnaire that was distributed in two primary schools on their upper level. The questionnaire shows preferences of pupils about the issue of the ideal teacher and his or her characteristics.

Beta-carotene is a provitamin, i.e. a precursor of vitamin A (retinol), which is classified as an essential nutrient for humans. Beta-carotene is one of many carotenoids found in plants, fungi and bacteria. Carotenoids are therefore predominantly obtained through foods of plant origin or food supplements. Carrots contribute approximately half of the total beta-carotene intake in the Norwegian diet, followed by mixed frozen vegetables, tomatoes, fruits and berries. VKM emphasises that this opinion on upper level (UL) for beta-carotene addresses beta-carotene in food supplements only. Beta-carotene from regular foods such as vegetables and fruits is not considered to be a health concern. In 2002, the Scientific Committee on Food (SCF) established a tolerable upper intake level (UL) for vitamin A (SCF, 2002). However, the SCF opinion covers only retinol compounds (various forms of vitamin A). The bioconversion of carotenoids to vitamin A in the body is well regulated and therefore only intake of vitamin A has been considered relevant for vitamin A toxicity (Blomhoff et al., 2003; EFSA, 2008). The Norwegian Food Safety Authority is considering whether beta-carotene should be regulated separately from retinol compounds.