645 research outputs found

    Screencasts: how effective are they and how do students engage with them?

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    The use of screencasts as an instructional technology is increasing rapidly in higher education. While there appears to be a consensus around students’ satisfaction with the provision of technology enhanced tools, there is limited evidence revolving around their impact in terms of knowledge acquisition. Moreover, the reasons why students choose to engage (or not) with these resources remain largely unreported. The study assessed the effect of using screencasts on undergraduate students’ understanding and engagement with learning material in one of their modules. Customised screencasts were used as optional additional learning and teaching resources. Grades obtained in a test module (with screencasts) and a control module (without screencasts) were compared to gauge the impact of screencasts on knowledge acquisition. Furthermore, the reasons for students’ engagement (or lack thereof) with the screencasts were explored using questionnaires. A modest but significant impact of screencasts on knowledge acquisition was found and students’ perception of the screencasts was overwhelmingly positive. Students suggested that screencasts should be kept short to summarise lectures or delve in-depth into complex concepts but should not replace whole lectures. Reasons for not using screencasts revolved around a lack of understanding of what the resources were but also a reported lack of fit between the nature of the tool and self-assessed learning style

    Screencasts: how effective are they and how do students engage with them?

    Get PDF
    The use of screencasts as an instructional technology is increasing rapidly in higher education. While there appears to be a consensus around students’ satisfaction with the provision of technology enhanced tools, there is limited evidence revolving around their impact in terms of knowledge acquisition. Moreover, the reasons why students choose to engage (or not) with these resources remain largely unreported. The study assessed the effect of using screencasts on undergraduate students’ understanding and engagement with learning material in one of their modules. Customised screencasts were used as optional additional learning and teaching resources. Grades obtained in a test module (with screencasts) and a control module (without screencasts) were compared to gauge the impact of screencasts on knowledge acquisition. Furthermore, the reasons for students’ engagement (or lack thereof) with the screencasts were explored using questionnaires. A modest but significant impact of screencasts on knowledge acquisition was found and students’ perception of the screencasts was overwhelmingly positive. Students suggested that screencasts should be kept short to summarise lectures or delve in-depth into complex concepts but should not replace whole lectures. Reasons for not using screencasts revolved around a lack of understanding of what the resources were but also a reported lack of fit between the nature of the tool and self-assessed learning style

    How do tsetse recognise their hosts? The role of shape in the responses of tsetse (Glossina fuscipes and G. palpalis) to artificial hosts

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    Palpalis-group tsetse, particularly the subspecies of Glossina palpalis and G. fuscipes, are the most important transmitters of human African trypanomiasis (HAT), transmitting .95% of cases. Traps and insecticide-treated targets are used to control tsetse but more cost-effective baits might be developed through a better understanding of the fly’s host-seeking behaviour.Electrocuting grids were used to assess the numbers of G. palpalis palpalis and G. fuscipes quanzensis attracted to and landing on square or oblong targets of black cloth varying in size from 0.01 m2 to 1.0 m2. For both species, increasing the size of a square target from 0.01 m2 (dimensions = 0.1 x 0.1 m) to 1.0 m2 (1.0 x 1.0 m) increased the catch ,4x however the numbers of tsetse killed per unit area of target declined with target size suggesting that the most cost efficient targets are not the largest. For G. f. quanzensis, horizontal oblongs, (1 m wide x 0.5 m high) caught, 1.8x more tsetse than vertical ones (0.5 m wide x 1.0 m high) but the opposite applied for G. p. palpalis. Shape preference was consistent over the range of target sizes. For G. p. palpalis square targets caught as many tsetse as the oblong; while the evidence is less strong the same appears to apply to G. f. quanzensis. The results suggest that targets used to control G. p. palpalis and G. f. quanzensis should be square, and that the most cost-effective designs, as judged by the numbers of tsetse caught per area of target, are likely to be in the region of 0.25 x 0.25 m2. The preference of G. p. palpalis for vertical oblongs is unique amongst tsetse species, and it is suggested that this response might be related to its anthropophagic behaviour and hence importance as a vector of HAT

    Mutual information rate and bounds for it

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    The amount of information exchanged per unit of time between two nodes in a dynamical network or between two data sets is a powerful concept for analysing complex systems. This quantity, known as the mutual information rate (MIR), is calculated from the mutual information, which is rigorously defined only for random systems. Moreover, the definition of mutual information is based on probabilities of significant events. This work offers a simple alternative way to calculate the MIR in dynamical (deterministic) networks or between two data sets (not fully deterministic), and to calculate its upper and lower bounds without having to calculate probabilities, but rather in terms of well known and well defined quantities in dynamical systems. As possible applications of our bounds, we study the relationship between synchronisation and the exchange of information in a system of two coupled maps and in experimental networks of coupled oscillators

    TOMOBFLOW: feature-preserving noise filtering for electron tomography

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    <p>Abstract</p> <p>Background</p> <p>Noise filtering techniques are needed in electron tomography to allow proper interpretation of datasets. The standard linear filtering techniques are characterized by a tradeoff between the amount of reduced noise and the blurring of the features of interest. On the other hand, sophisticated anisotropic nonlinear filtering techniques allow noise reduction with good preservation of structures. However, these techniques are computationally intensive and are difficult to be tuned to the problem at hand.</p> <p>Results</p> <p>TOMOBFLOW is a program for noise filtering with capabilities of preservation of biologically relevant information. It is an efficient implementation of the Beltrami flow, a nonlinear filtering method that locally tunes the strength of the smoothing according to an edge indicator based on geometry properties. The fact that this method does not have free parameters hard to be tuned makes TOMOBFLOW a user-friendly filtering program equipped with the power of diffusion-based filtering methods. Furthermore, TOMOBFLOW is provided with abilities to deal with different types and formats of images in order to make it useful for electron tomography in particular and bioimaging in general.</p> <p>Conclusion</p> <p>TOMOBFLOW allows efficient noise filtering of bioimaging datasets with preservation of the features of interest, thereby yielding data better suited for post-processing, visualization and interpretation. It is available at the web site <url>http://www.ual.es/%7ejjfdez/SW/tomobflow.html</url>.</p

    Evolution number of litigation cases and expenditure with monoclonal antibodies (MoAbs) (Bevacizumab, Cetuximab and Panitumumab) and tirosine kinase inhibitor (Regorafenib) for the treatment of cancer in Minas Gerais-Brazil : A preliminary analysis from 2009 to 2016

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    Introduction: The last decade was marked by the widespread use of molecular biological agents in combination with 5-FU / oxaliplatin or irinotecan-containing regimens in the treatment of cancer. Such biological medicines have significantly increased the costs of oncological treatment, leading to concerns about the future sustainability of drug policy and, as a consequence, health systems with universal access to health care. In the case of Brazil, the tree MoAbs BEVACIZUMAB(BEVA), CETUXIMAB(CETUX), PANITUMUMAB(PANIT) and one tirosin kinase inhibitor REGORAFENIB(REGORA) compared in this study can only be used by the patient when there is a litigation against the State, since they are not incorporated into the Single System of Health-SUS. Objectives: To evaluate the evolution number of litigation cases and expenditure with monoclonal antibodies(MoAbs) (Bevacizumab, Cetuximab and Panitumumab) and tirosin kinase inhibitor (Regorafenib) for the treatment of cancer in Minas Gerais-Brazil. Method: Retrospective descriptive study whose judicial information was extracted from the database of the Minas Gerais State Secretariat - SES-MG. The judicial actions were filed against the State of Minas Gerais for Cancer treatment and refer to the period from January 2009 to December 2016. The study was cut from the judicialized MoAbs (BEVA, CETUX, PANIT) and tirosin kinase inhibitor (REGORA) for the treatment of Colorectal Cancer (CCR). The cost of the treatments was calculated based on the prices of the Câmara de Regulação do Mercado de Medicamentos (CMED) ANVISA, taking into account the official dollar exchange rate of the Central Bank on January 31, 2018 and there is no adjustment for inflation. Results and discussion: Preliminary results showed that in the period between 2009 and 2016, 1024 lawsuits were filed against the State of Minas Gerais for cancer treatment, making 766 for BEVA, 206 for CETUX, 35 for PANIT and 17 for REGORA . The total cost obtained considering a 6-month overall survival for each patient was $ 22,260,536. In Brazil, the growing number of litigation and drug costs (BEVA, CETUX, PANIT and REGORA) per year is worrying, considering the increase of 5.100% for judicial actions and 1899% for treatment costs in the period 2009 to 2016 (TABLE 1). Conclusion: The exponential increase in lawsuits against the State of Minas Gerais demonstrates the growing pressure on the resources available to attend a reduced number of patients, who are available to judicialize treatments outside universal health coverage, which is already guaranteed right by the Brazilian constitution

    The Homeodomain Derived Peptide Penetratin Induces Curvature of Fluid Membrane Domains

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    BACKGROUND:Protein membrane transduction domains that are able to cross the plasma membrane are present in several transcription factors, such as the homeodomain proteins and the viral proteins such as Tat of HIV-1. Their discovery resulted in both new concepts on the cell communication during development, and the conception of cell penetrating peptide vectors for internalisation of active molecules into cells. A promising cell penetrating peptide is Penetratin, which crosses the cell membranes by a receptor and metabolic energy-independent mechanism. Recent works have claimed that Penetratin and similar peptides are internalized by endocytosis, but other endocytosis-independent mechanisms have been proposed. Endosomes or plasma membranes crossing mechanisms are not well understood. Previously, we have shown that basic peptides induce membrane invaginations suggesting a new mechanism for uptake, "physical endocytosis". METHODOLOGY/PRINCIPAL FINDINGS:Herein, we investigate the role of membrane lipid phases on Penetratin induced membrane deformations (liquid ordered such as in "raft" microdomains versus disordered fluid "non-raft" domains) in membrane models. Experimental data show that zwitterionic lipid headgroups take part in the interaction with Penetratin suggesting that the external leaflet lipids of cells plasma membrane are competent for peptide interaction in the absence of net negative charges. NMR and X-ray diffraction data show that the membrane perturbations (tubulation and vesiculation) are associated with an increase in membrane negative curvature. These effects on curvature were observed in the liquid disordered but not in the liquid ordered (raft-like) membrane domains. CONCLUSIONS/SIGNIFICANCE:The better understanding of the internalisation mechanisms of protein transduction domains will help both the understanding of the mechanisms of cell communication and the development of potential therapeutic molecular vectors. Here we showed that the membrane targets for these molecules are preferentially the fluid membrane domains and that the mechanism involves the induction of membrane negative curvature. Consequences on cellular uptake are discussed
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