Quality Assessment for E-learning: a Benchmarking Approach (Third edition)

The primary purpose of this manual is to provide a set of benchmarks, quality criteria and notes for guidance against which e-learning programmes and their support systems may be judged. The manual should therefore be seen primarily as a reference tool for the assessment or review of e-learning programmes and the systems which support them. However, the manual should also prove to be useful to staff in institutions concerned with the design, development, teaching, assessment and support of e-learning programmes. It is hoped that course developers, teachers and other stakeholders will see the manual as a useful development and/or improvement tool for incorporation in their own institutional systems of monitoring, evaluation and enhancement

Optimization of a reinforced concrete structure subjected to dynamic wind action

This work proposes a methodology to optimize a reinforced concrete structure. For this, the Whale Optimization Algorithm (WOA) algorithm was used, an algorithm from the group of metaheuristic algorithms, which presents an easy computational implementation. As a study object, a frame structure adapted from a real reinforced concrete building was used, subjected to the dynamic action of artificially generated synoptic wind. The objective function is to reduce the volume of concrete of the structure. For that, the dimensions of the cross-sections were used as design variables, and the maximum displacement at the top imposed by the ASCE / SEI 7-10 standard as a lateral constraint, as well as the maximum story drift between floors. In addition to this structural optimization, it was also proposed the use and optimization of Tuned Mass Dampers (TMD), in different quantities, positions and parameters, improving the dynamic response of the reinforced concrete building. The results show that for this situation it was possible to reduce the concrete volume of the structure by approximately 24%, respecting the maximum limit of displacement at the top required by the standard

Nucleopolyhedrovirus coocclusion technology: a new concept in the development of biological insecticides

Nucleopolyhedroviruses (NPV, Baculoviridae) that infect lepidopteran pests have an established record as safe and effective biological insecticides. Here, we describe a new approach for the development of NPV-based insecticides. This technology takes advantage of the unique way in which these viruses are transmitted as collective infectious units, and the genotypic diversity present in natural virus populations. A ten-step procedure is described involving genotypic variant selection, mixing, coinfection and intraspecific coocclusion of variants within viral occlusion bodies. Using two examples, we demonstrate how this approach can be used to produce highly pathogenic virus preparations for pest control. As restricted host range limits the uptake of NPV-based insecticides, this technology has recently been adapted to produce custom-designed interspecific mixtures of viruses that can be applied to control complexes of lepidopteran pests on particular crops, as long as a shared host species is available for virus production. This approach to the development of NPV-based insecticides has the potential to be applied across a broad range of NPV-pest pathosystems.This review was funded by the Ministerio de Economía y Competitividad, Spain, project number AGL2017-83498-C2-1-R and previous projects AGL2014-57752-C2-1-R, AGL2011-30352-CO2-01, AGL2008-05456-C03-01, AGL2005-07909-CO3-01, and AGL2002-04320-C02-01

Antiparasitic activity of chicory (Cichorium intybus) and its natural bioactive compounds in livestock: a review

Increasing drug resistance in gastrointestinal (GI) parasites of livestock and concerns about chemical residues in animal products and the environment are driving the development of alternative control strategies that are less reliant on the use of synthetic drugs. An increasingly investigated approach is the use of bioactive forages with antiparasitic properties as part of the animal’s diet (nutraceuticals) or as potential sources of novel, natural parasiticides. Chicory (Cichorium intybus) is a multi-purpose crop and one of the most promising bioactive forages in temperate regions, and numerous in vivo trials have explored its potential against parasitic nematodes in livestock. However, it is unclear whether chicory can induce a direct and broad activity against various GI parasites in different livestock species, and the levels of chicory in the diet that are required to exert an efficient antiparasitic effect. Moreover, the mechanisms leading to the reported parasiticidal activity of chicory are still largely unknown, and its bioactive phytochemicals have only recently been investigated. In this review, we summarise the progress in the study of the antiparasitic activity of chicory and its natural bioactive compounds against GI parasites in livestock, through examination of the published literature. The available evidence indicates that feeding chicory can reduce faecal egg counts and/or worm burdens of abomasal nematodes, but not infections with intestinal worms, in ruminants. Highly chicory-rich diets (≥ 70% of chicory dry matter in the diet) may be necessary to directly affect abomasal parasitism. Chicory is known to synthesise several bioactive compounds with potential antiparasitic activity, but most research has been devoted to the role of sesquiterpene lactones (SL). Recent in vitro studies have confirmed direct and potent activity of SL-rich extracts from chicory against different GI helminths of livestock. Chicory SL have also been reported to exhibit antimalarial properties and its potential antiprotozoal activity in livestock remains to be evaluated. Furthermore, the detailed identification of the main antiparasitic metabolites of chicory and their pharmacokinetics need further confirmation. Research gaps and perspectives on the potential use of chicory as a nutraceutical forage and a source of bioactive compounds for parasite control in livestock are discussed

A Skin Substitute Reepithelialization Calculator for Natural, Synthetic, and Composite Skin Cell Scaffolds

Tissue engineering is a rapidly advancing field. Researchers around the globe have been working on novel ways to replicate the natural properties of tissues and organs. While new technologies enable increasingly complex therapeutics few of them have been found to be acceptable for clinical use. The skin is an excellent test bed for the techniques necessary for organ replacement. Skin is naturally regenerative, easily accessible and not as metabolically active as many other organs. This study analyzes published work to compare the epithelial wound repair rates of natural, synthetic, and hybrid tissue engineered skin substitutes to develop a wound repair calculator. Over 1,000 data points were utilized from 232 papers, linear regression produced a wound repair rate equal to the amount of wound repair per hour for each therapeutic class. Repair rates varied widely both within and across different therapeutics. Precision tests of the calculator’s accuracy using 30 papers produced little concordance. The data reported in the tissue engineering papers examined here vary too greatly for accurate predictions of reepithelialization suggesting that the driving force in wound repair is not being effectively accounted for within the published works

Deconstructing the smoking-preeclampsia paradox through a counterfactual framework.

Although smoking during pregnancy may lead to many adverse outcomes, numerous studies have reported a paradoxical inverse association between maternal cigarette smoking during pregnancy and preeclampsia. Using a counterfactual framework we aimed to explore the structure of this paradox as being a consequence of selection bias. Using a case-control study nested in the Icelandic Birth Registry (1309 women), we show how this selection bias can be explored and corrected for. Cases were defined as any case of pregnancy induced hypertension or preeclampsia occurring after 20 weeks' gestation and controls as normotensive mothers who gave birth in the same year. First, we used directed acyclic graphs to illustrate the common bias structure. Second, we used classical logistic regression and mediation analytic methods for dichotomous outcomes to explore the structure of the bias. Lastly, we performed both deterministic and probabilistic sensitivity analysis to estimate the amount of bias due to an uncontrolled confounder and corrected for it. The biased effect of smoking was estimated to reduce the odds of preeclampsia by 28 % (OR 0.72, 95 %CI 0.52, 0.99) and after stratification by gestational age at delivery ( 1, revealing the structure of the paradox. The bias-adjusted estimation of the smoking effect on preeclampsia showed an OR of 1.22 (95 %CI 0.41, 6.53). The smoking-preeclampsia paradox appears to be an example of (1) selection bias most likely caused by studying cases prevalent at birth rather than all incident cases from conception in a pregnancy cohort, (2) omitting important confounders associated with both smoking and preeclampsia (preventing the outcome to develop) and (3) controlling for a collider (gestation weeks at delivery). Future studies need to consider these aspects when studying and interpreting the association between smoking and pregnancy outcomes

Thermal noise suppression: how much does it cost?

In order to stabilize the behavior of noisy systems, confining it around a desirable state, an effort is required to suppress the intrinsic noise. This noise suppression task entails a cost. For the important case of thermal noise in an overdamped system, we show that the minimum cost is achieved when the system control parameters are held constant: any additional deterministic or random modulation produces an increase of the cost. We discuss the implications of this phenomenon for those overdamped systems whose control parameters are intrinsically noisy, presenting a case study based on the example of a Brownian particle optically trapped in an oscillating potential.Comment: 6 page

Sesquiterpene lactone-containing extracts from two chicory cultivars show different anthelmintic activity in vitro against Ostertagia ostertagi

Mechanisms behind reported in vivo anthelmintic effects of chicory (Cichorium intybus) in ruminants are poorly understood but it is likely that plant compounds, like sesquiterpene lactones (SL), play a role. Objectives: The aim was to test the inhibitory activity of SL-containing extracts from two chicory cultivars on free-living and parasitic stages of Ostertagia ostertagi. Methods: Leaves from chicory cv. Spadona and cv. Puna II were freeze-dried and SL extracted with methanol/water. Resulting extracts were incubated with cellulase enzyme and SL were purified from other plant compounds by normal solid-phase extraction. Purified extracts were dissolved in DMSO. O. ostertagi eggs from a mono-infected calf were hatched and first-stage larvae (L1) were used in a larval feeding inhibition assay (LFIA), while L3 cultured from faeces were used in a larval exsheathment inhibition assay (LEIA). O. ostertagi adult worms recovered post-mortem were used for motility inhibition assays (AMIA) and worm motility was evaluated after 6, 24 and 48 h of incubation (37oC). In all in vitro assays, decreasing concentrations of chicory extracts in PBS (1% DMSO) were tested in triplicates with 1% DMSO in PBS as negative control. Chemical profile of the extracts was analysed by liquid chromatography (LC). Results: In the LFIA Spadona-extract inhibited larval feeding at significantly lower concentrations than Puna II-extract (EC50=31.5 [CI=25.9-38.3] g Spadona-extract/mL vs. EC50=121.1 [CI=95.2-153.8] g Puna II-extract/mL; p<0.0001). In the LEIA extracts from neither of the two cultivars interfered with the exsheathment of L3 at any of the tested concentrations. In the AMIA, Spadona-extract showed a significantly higher potency and exerted faster worm paralysis than Puna II-extract at all time points when tested at equal concentrations (p<0.0001). Preliminary LC analyses revealed different SL profiles of the extracts and further chemical characterization is undergoing. Discussion: The observed anthelmintic effects of SL-containing extracts from chicory seem to be stage-specific as L1 and adult O. ostertagi but not L3 were affected. Different anthelmintic potency of SL-containing extracts from different chicory cultivars may help the identification of the most active(s) compound(s) and of cultivars with higher antiparasitic potential

Study of the oxygen vacancies changes in SnO2 polycrystalline thick films using impedance and photoemission spectroscopies

Changes in the concentration of oxygen vacancies within the grains of polycrystalline SnO2, due to different atmosphere exposures, were detected using impedance and photoemission spectroscopies. From measured capacitance values, variations of the potential barrier widths could be determined. It is shown that under the presence of an oxygen rich atmosphere, at relatively low temperature, the width of intergranular potential barriers increase to the point that grains become completely depleted of carriers. With subsequent exposure to vacuum, capacitance adopts a higher value, indicative of intergranular barriers and quasi-neutral regions at the center of the grains. X-ray and ultraviolet photoemission spectroscopy measurements showed that SnO2 samples treated in oxidizing or reducing environments have similar barrier heights and different work functions. Results are especially relevant in the study of mechanisms responsible for metal oxide gas sensingFil: Schipani, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Ponce, Miguel Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Joanni, Ednan. CTI Renato Archer. Sao Paulo; BrasilFil: Williams, Federico Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Aldao, Celso Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentin