3,437 research outputs found

    An Exploratory Study of Students' Perceptions on the Use of Animals in Medical and Veterinary Medical Undergraduate Education

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    Animals are frequently utilized as a teaching-learning tool in multiple educational settings. It is, therefore, important to understand what students think about this topic, in particular medical and veterinary students as “life caregivers” and competent people for a dynamic and responsible social intervention. In this context, this research aims to characterize and disseminate a set of issues related to animal welfare/wellbeing in higher education in the North of Portugal, particularly as regards the teaching of students of the Integrated Master in Medicine (MIM) and Veterinary Medicine (MIMV). After ethical approval, a survey was delivered on paper to 180 undergraduate MIM (n = 100) and MIMV (n = 80) students. After collecting 139 questionnaires partially or fully completed, with varying response rates for each question, it was concluded that most of the students consider that animal experimentation is ethically acceptable when the benefits balance the harms and assuming that refinement of animal procedures is warranted; they also agree to the establishment, maintenance and performance of animal procedures solely for educational purposes as a way of ensuring optimal acquisition of theoretical knowledge, attitudes and behaviors and technical skills. Nevertheless, it is the responsibility of teachers to explore and implement pedagogical methodologies thar are equally effective but more humane and compassionate towards sentient living beings.Open access funding provided by FCT|FCCN (b-on). The authors did not receive support from any organization for the submitted work

    Thiol modifier effects of diphenyl diselenides: insight from experiment and DFT calculations

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    A combination of spectroscopic, chromatographic and computational approaches was employed to investigate the reaction of several diselenides of formula (R-PhSe)(2) (R = CH3O, CH3, H, Cl, CF3) with a thiolate nucleophile, leading to the breaking of the selenium-selenium (Se-Se) bond. This process has fundamental importance in biological environments and provides a rationale to analyze the so-called thiol modifier effect of diselenides, which may be exploited in pharmacology and toxicology. Our data suggest that withdrawing substituents favor the reaction, effectively making the reaction energy more negative, but strong electron-withdrawing groups also prompt structural modification on the starting reactant, increasing the reaction barrier. Thus, the nature (electron rich or electron poor) of the diselenides can play an essential role in the reactivity and biological activity of these molecules

    Cyclic behaviour of stone and brick masonry under uniaxial compressive loading

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    An experimental research concerning the uniaxial compressive behaviour of stone and brick specimens, as well as masonry prisms, is presented. Local sandstone and clay brick materials were used in order to obtain results representative with respect to local constructions. Aiming at a comprehensive material description, a set of displacementcontrolled experiments were carried out, both under monotonic and cyclic compressive loading. The procedure adopted for testing is described and the results are discussed, namely material brittleness, intrinsic variability, energy dissipation and stiffness degradation.Dans cet article une recherche expérimentale à propos du comportement en compression uniaxial de spécimens de pierre et de la brique, aussi bien que prismes de maçonnerie, est présenté. Grès et brique de l’argile locale ont été utilisés pour obtenir des résultats représentatifs en ce qui concerne les constructions locales. Avec l’objective de obtenir une description matérielle complète, un ensemble de tests contrôlé par déplacement a été emporté, sous chargement de compression monotonic et cyclique. La procédure adoptée pour tester est décrite et les résultats sont discutés, nommément la fragilité matérielle, variabilité intrinsèque des matériaux, dissipation d’énergie et déchéance de la raideur

    Genetic and Functional Analyses of SHANK2 Mutations Suggest a Multiple Hit Model of Autism Spectrum Disorders

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    Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While many rare variants in synaptic proteins have been identified in patients with ASD, little is known about their effects at the synapse and their interactions with other genetic variations. Here, following the discovery of two de novo SHANK2 deletions by the Autism Genome Project, we identified a novel 421 kb de novo SHANK2 deletion in a patient with autism. We then sequenced SHANK2 in 455 patients with ASD and 431 controls and integrated these results with those reported by Berkel et al. 2010 (n = 396 patients and n = 659 controls). We observed a significant enrichment of variants affecting conserved amino acids in 29 of 851 (3.4%) patients and in 16 of 1,090 (1.5%) controls (P = 0.004, OR = 2.37, 95% CI = 1.23-4.70). In neuronal cell cultures, the variants identified in patients were associated with a reduced synaptic density at dendrites compared to the variants only detected in controls (P = 0.0013). Interestingly, the three patients with de novo SHANK2 deletions also carried inherited CNVs at 15q11-q13 previously associated with neuropsychiatric disorders. In two cases, the nicotinic receptor CHRNA7 was duplicated and in one case the synaptic translation repressor CYFIP1 was deleted. These results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the "multiple hit model" for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD

    Herschel survey of brown dwarf disks in Rho Ophiuchi

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    Recent observations of the Rho Ophiuchi cluster with the Herschel Space Observatory allow us to probe the spectral energy distribution (SED) of the brown dwarf population in the far-IR, where the disk emission peaks. We performed aperture photometry at 70, 100, and 160 micron, and constructed SEDs for all previously known brown dwarfs detected. These were complemented with ancillary photometry at shorter wavelengths. We compared the observed SEDs to a grid of synthetic disks produced with the radiative transfer code MCFOST, and used the relative figure of merit estimated from the Bayesian inference of each disk parameter to analyse the structural properties. We detected 12 Class II brown dwarfs with Herschel, which corresponds to one-third of all currently known brown dwarf members of Rho Ophiuchi. We do not detect any of the known Class III brown dwarfs. Comparison to models reveals that the disks are best described by an inner radius between 0.01 and 0.07 AU, and a flared disk geometry with a flaring index between 1.05 and 1.2. Furthermore, we can exclude values of the disk scale-height lower than 10 AU (measured at a fiducial radius of 100 AU). We combined the Herschel data with recent ALMA observations of the brown dwarf GY92 204 (ISO-Oph 102), and by comparing its SED to the same grid of disk models, we derived an inner disk radius of 0.035 AU, a scale height of 15 AU with a flaring index of beta~1.15, an exponent for dust settling of -1.5, and a disk mass of 0.001 MSun. This corresponds to a disk-to-central object mass ratio of ~1%. The structural parameters constrained by the extended SED coverage (inner radius and flaring index) show a narrow distribution for the 11 young brown dwarfs detected in Rho Ophiuchi, suggesting that these objects share the same disk evolution and, perhaps, formation.Comment: Accepted for publication in A&

    Phred-Phrap package to analyses tools: a pipeline to facilitate population genetics re-sequencing studies

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    BACKGROUND: Targeted re-sequencing is one of the most powerful and widely used strategies for population genetics studies because it allows an unbiased screening for variation that is suitable for a wide variety of organisms. Examples of studies that require re-sequencing data are evolutionary inferences, epidemiological studies designed to capture rare polymorphisms responsible for complex traits and screenings for mutations in families and small populations with high incidences of specific genetic diseases. Despite the advent of next-generation sequencing technologies, Sanger sequencing is still the most popular approach in population genetics studies because of the widespread availability of automatic sequencers based on capillary electrophoresis and because it is still less prone to sequencing errors, which is critical in population genetics studies. Two popular software applications for re-sequencing studies are Phred-Phrap-Consed-Polyphred, which performs base calling, alignment, graphical edition and genotype calling and DNAsp, which performs a set of population genetics analyses. These independent tools are the start and end points of basic analyses. In between the use of these tools, there is a set of basic but error-prone tasks to be performed with re-sequencing data. RESULTS: In order to assist with these intermediate tasks, we developed a pipeline that facilitates data handling typical of re-sequencing studies. Our pipeline: (1) consolidates different outputs produced by distinct Phred-Phrap-Consed contigs sharing a reference sequence; (2) checks for genotyping inconsistencies; (3) reformats genotyping data produced by Polyphred into a matrix of genotypes with individuals as rows and segregating sites as columns; (4) prepares input files for haplotype inferences using the popular software PHASE; and (5) handles PHASE output files that contain only polymorphic sites to reconstruct the inferred haplotypes including polymorphic and monomorphic sites as required by population genetics software for re-sequencing data such as DNAsp. CONCLUSION: We tested the pipeline in re-sequencing studies of haploid and diploid data in humans, plants, animals and microorganisms and observed that it allowed a substantial decrease in the time required for sequencing analyses, as well as being a more controlled process that eliminates several classes of error that may occur when handling datasets. The pipeline is also useful for investigators using other tools for sequencing and population genetics analyses

    Revisão da literatura sobre conhecimentos, atitudes e comportamentos dos estudantes do ensino superior sobre o desenvolvimento sustentável

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    As Instituições de Ensino Superior (IES) têm um papel a desempenhar na Educação para o Desenvolvimento Sustentável (EDS) uma vez que podem promover a sensibilização, a compreensão e a ação em prol do Desenvolvimento Sustentável (DS) e dos Objetivos do Desenvolvimento Sustentável (ODS). As IES contribuem para provocar mudanças e transformações na sociedade, promovendo políticas, estratégias e métodos que permitam a construção de um mundo mais sustentável. Identificar os conhecimentos a adquirir e as atitudes e os comportamentos a desenvolver, pelos estudantes do Ensino Superior no âmbito do DS, é um desafio que merece ser prosseguido. Os estudantes das IES devem estar conscientes dos ODS e da forma como podem contribuir para a sua prossecução, não só enquanto estudantes, mas também como futuros profissionais e decisores em diferentes áreas (Bello et al., 2020; Leal Filho et al., 2019). O objetivo desta revisão da literatura é identificar os estudos existentes que abordam os conhecimentos, as atitudes e os comportamentos dos estudantes do ensino superior em relação ao DS e/ou aos ODS e sintetizar os seus principais resultados. Vários estudos têm-se centrado em fatores diretamente relacionados com os estudantes do ensino superior, contribuindo para medir os seus conhecimentos, atitudes e comportamentos em relação ao DS: (i) Borges (2019) mostrou que havia conhecimentos e atitudes muito favoráveis em relação ao DS entre estudantes do ensino superior, porém os comportamentos foram menos favoráveis; (ii) Balakrishnan et al. (2020) verificaram que os inquiridos tinham perceções e atitudes positivas em relação a todas as dimensões da sustentabilidade - ambiental, económica e social; (iii) Eagle et al. (2015) revelaram com o seu estudo que os estudantes mostram uma tendência para considerar que as questões fundamentais estão fora do seu controlo pessoal e acreditam que as soluções têm de ser encontradas por outros; (iv) em Al-Naqbi e lshannag (2018) os estudantes demonstraram uma elevada compreensão, atitudes positivas muito fortes e comportamentos moderadamente positivos em relação à EDS e ao ambiente; (v) os resultados de Zamora-Polo et al. (2019) mostram que o conhecimento dos ODS é baixo; foram encontradas diferenças significativas entre as pontuações obtidas nas implicações profissionais e pessoais dos ODS; (vi) segundo Leiva-Brondo et al. (2022) muitos estudantes afirmam estar cientes dos ODS, mas a maioria não tem uma compreensão completa destes 17 objetivos e da sua implementação atual, apesar de acreditarem que os ODS são importantes na sua vida quotidiana; (vii) Afroz e Ilham (2020) mostraram que os inquiridos têm um elevado conhecimento e uma atitude positiva em relação aos ODS. Neste trabalho, após a sistematização das principais conclusões dos estudos selecionados, apresenta-se algumas lacunas existentes na investigação, bem como orientações para estudos futuros.info:eu-repo/semantics/publishedVersio

    Astrobiological Complexity with Probabilistic Cellular Automata

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    Search for extraterrestrial life and intelligence constitutes one of the major endeavors in science, but has yet been quantitatively modeled only rarely and in a cursory and superficial fashion. We argue that probabilistic cellular automata (PCA) represent the best quantitative framework for modeling astrobiological history of the Milky Way and its Galactic Habitable Zone. The relevant astrobiological parameters are to be modeled as the elements of the input probability matrix for the PCA kernel. With the underlying simplicity of the cellular automata constructs, this approach enables a quick analysis of large and ambiguous input parameters' space. We perform a simple clustering analysis of typical astrobiological histories and discuss the relevant boundary conditions of practical importance for planning and guiding actual empirical astrobiological and SETI projects. In addition to showing how the present framework is adaptable to more complex situations and updated observational databases from current and near-future space missions, we demonstrate how numerical results could offer a cautious rationale for continuation of practical SETI searches.Comment: 37 pages, 11 figures, 2 tables; added journal reference belo
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