18 research outputs found

    Leaving the Abstract for the Concrete in Written Expression in Elementary School in Benin

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    This article aims at analysing and influencing the pedagogical practices of six teachers involved in an action-research in written expression in the Elementary Course at the elementary school in Benin in order to optimize the learning capacities of the pupils. To this end, a research protocol was adopted that included a stage of identification of the problem, the establishment of an action plan, the implementation of the action, the evaluation of the effects of the action, the communication of the conclusions and the valorisation of the research. It was found that the teachers did not maximize the children's learning opportunities during the "chasse aux idées" phase; they did not get the children moving; they did not praise them properly; they remained in the abstract about the themes addressed. Several decisions were taken at each stage of the progression in the realization of the sequence II in written expression (first draft), the most important of which is the concretization based on clear and expressive images and reinforced by social writing

    Issues of geologically-focused situational awareness in robotic planetary missions: lessons from an analogue mission at Mistastin Lake impact structure, Labrador, Canada

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    Remote robotic data provides different information than that obtained from immersion in the field. This significantly affects the geological situational awareness experienced by members of a mission control science team. In order to optimize science return from planetary robotic missions, these limitations must be understood and their effects mitigated to fully leverage the field experience of scientists at mission control. Results from a 13-day analogue deployment at the Mistastin Lake impact structure in Labrador, Canada suggest that scale, relief, geological detail, and time are intertwined issues that impact the mission control science team‟s effectiveness in interpreting the geology of an area. These issues are evaluated and several mitigation options are suggested. Scale was found to be difficult to interpret without the reference of known objects, even when numerical scale data were available. For this reason, embedding intuitive scale-indicating features into image data is recommended. Since relief is not conveyed in 2D images, both 3D data and observations from multiple angles are required. Furthermore, the 3D data must be observed in animation or as anaglyphs, since without such assistance much of the relief information in 3D data is not communicated. Geological detail may also be missed due to the time required to collect, analyze, and request data. We also suggest that these issues can be addressed, in part, by an improved understanding of the operational time costs and benefits of scientific data collection. Robotic activities operate on inherently slow time-scales. This fact needs to be embraced and accommodated. Instead of focusing too quickly on the details of a target of interest, thereby potentially minimizing science return, time should be allocated at first to more broad data collection at that target, including preliminary surveys, multiple observations from various vantage points, and progressively smaller scale of focus. This operational model more closely follows techniques employed by field geologists and is fundamental to the geologic interpretation of an area. Even so, an operational time cost/benefit analyses should be carefully considered in each situation, to determine when such comprehensive data collection would maximize the science return. Finally, it should be recognized that analogue deployments cannot faithfully model the time scales of robotic planetary missions. Analogue missions are limited by the difficulty and expense of fieldwork. Thus, analogue deployments should focus on smaller aspects of robotic missions and test components in a modular way (e.g., dropping communications constraints, limiting mission scope, focusing on a specific problem, spreading the mission over several field seasons, etc.)

    A three month controlled intervention of intermittent whole body vibration designed to improve functional ability and attenuate bone loss in patients with rheumatoid arthritis

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    Background: Rheumatoid arthritis (RA) is a chronic autoimmune condition that results in pain and disability. Patients with RA have a decreased functional ability and are forced into a sedentary lifestyle and as such, these patients often become predisposed to poor bone health. Patients with RA may also experience a decreased health related quality of life (HRQoL) due to their disease. Whole body vibration (WBV) is a form of exercise that stimulates bone loading through forced oscillation. WBV has also been shown to decrease pain and fatigue in other rheumatic diseases, as well as to increase muscle strength. This paper reports on the development of a semi randomised controlled clinical trial to assess the impact of a WBV intervention aiming to improve functional ability, attenuate bone loss, and improve habitual physical activity levels in patients with RA. Methods/Design: This study is a semi randomised, controlled trial consisting of a cohort of patients with established RA assigned to either a WBV group or a CON (control) group. Patients in the WBV group will undergo three months of twice weekly intermittent WBV sessions, while the CON group will receive standard care and continue with normal daily activities. All patients will be assessed at baseline, following the three month intervention, and six months post intervention. Main outcomes will be an improvement in functional ability as assessed by the HAQ. Secondary outcomes are attenuation of loss of bone mineral density (BMD) at the hip and changes in RA disease activity, HRQoL, habitual physical activity levels and body composition. Discussion: This study will provide important information regarding the effects of WBV on functional ability and BMD in patients with RA, as well as novel data regarding the potential changes in objective habitual physical activity patterns that may occur following the intervention. The sustainability of the intervention will also be assessed

    A mission control architecture for robotic lunar sample return as field tested in an analogue deployment to the Sudbury impact structure

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    A Mission Control Architecture is presented for a Robotic Lunar Sample Return Mission which builds upon the experience of the landed missions of the NASA Mars Exploration Program. This architecture consists of four separate processes working in parallel at Mission Control and achieving buy-in for plans sequentially instead of simultaneously from all members of the team. These four processes were: Science Processing, Science Interpretation, Planning and Mission Evaluation. Science Processing was responsible for creating products from data downlinked from the field and is organized by instrument. Science Interpretation was responsible for determining whether or not science goals are being met and what measurements need to be taken to satisfy these goals. The Planning process, responsible for scheduling and sequencing observations, and the Evaluation process that fostered inter-process communications, reporting and documentation assisted these processes. This organization is advantageous for its flexibility as shown by the ability of the structure to produce plans for the rover every two hours, for the rapidity with which Mission Control team members may be trained and for the relatively small size of each individual team. This architecture was tested in an analogue mission to the Sudbury impact structure from June 6-17, 2011. A rover was used which was capable of developing a network of locations that could be revisited using a teach and repeat method. This allowed the science team to process several different outcrops in parallel, downselecting at each stage to ensure that the samples selected for caching were the most representative of the site. Over the course of 10 days, 18 rock samples were collected from 5 different outcrops, 182 individual field activities - such as roving or acquiring an image mosaic or other data product - were completed within 43 command cycles, and the rover travelled over 2,200 m. Data transfer from communications passes were filled to 74%. Sample triage was simulated to allow down-selection to 1kg of material for return to Earth

    Single-molecule techniques to study chromatin.

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    Besides the basic organization in nucleosome core particles (NCPs), eukaryotic chromatin is further packed through interactions with numerous protein complexes including transcription factors, chromatin remodeling and modifying enzymes. This nucleoprotein complex provides the template for many important biological processes, such as DNA replication, transcription, and DNA repair. Thus, to understand the molecular basis of these DNA transactions, it is critical to define individual changes of the chromatin structure at precise genomic regions where these machineries assemble and drive biological reactions. Single-molecule approaches provide the only possible solution to overcome the heterogenous nature of chromatin and monitor the behavior of individual chromatin transactions in real-time. In this review, we will give an overview of currently available single-molecule methods to obtain mechanistic insights into nucleosome positioning, histone modifications and DNA replication and transcription analysis-previously unattainable with population-based assays

    Whole-body vibration and rehabilitation of chronic diseases: A review of the literature

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    The objectives of the study were to review the current literature and findings on the effects of whole-body vibration (WBV) as a training method on performance and its ability to aid in the rehabilitation of chronic diseases (neurological, musculoskeletal or metabolic conditions). Six electronic databases were searched. The combination of the search terminology used included WBV and several neurological, musculoskeletal and metabolic conditions. Twenty six papers were found to be relevant for this review and were included for critical evaluation with regards to sample characteristics, research intervention and methodology. Most studies were conducted on patients diagnosed with neurological conditions (n = 15) while less were performed on patients suffering from musculoskeletal (n = 7) or metabolic (n = 4) disorders. Comparisons were difficult to draw on because of the different pathologies and the differences in the methodology of each study. Some of the observed methodological flaws included limitations in relation to insufficient randomisation, lack of sample homogeneity (size, age variability) and poor blinding in most studies. No consensus could be reached as to whether WBV is more effective than other interventions or no intervention at all, while the additional effects that WBV may have in relation to other interventions could not be assumed. Nevertheless, chronic WBV training seems to only improve strength in neurological patients while balance and mobility improves only in patients suffering from musculoskeletal or metabolic but not from neurological conditions. Although WBV did not prove to be more effective compared to other training methods, it can be used, in some cases, as a less fatiguing and less time-consuming method to enhance physical capabilities. Future research should focus on the effectiveness of WBV in relation to no treatment at all, and to age

    The acute effects of different whole-body vibration amplitudes and frequencies on flexibility and vertical jumping performance

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    Frequency and amplitude determine the training load of whole-body vibration (WBV) exercise and thereby possible neuromuscular adaptations. We investigated the effects of amplitude and frequency of a single bout of WBV on flexibility and squat jump performance (SJ) and the time-course of these effects. In the amplitude study, twenty-five females performed three vibration protocols (VPs) for 6 min at frequency of 25 Hz and amplitudes of 4 mm, 6 mm, and 8 mm and one control protocol (CP). In the frequency study, eighteen females performed three VPs at 6 mm amplitude and frequencies of 15 Hz, 20 Hz, and 30Hz and one CP. Flexibility and SJ were measured before, immediately-post and 15 min recovery. All protocols were performed on a side-to-side alternating vibration plate. In the amplitude study, flexibility was improved (p < 0.01) immediately-post in VP4, VP6, VP8 (31.8 +/- 8.2, 31.9 +/- 7.6, 31.5 +/- 7.9, respectively) and at 15 min recovery (31.6 +/- 8.1, 31.5 +/- 7.9, 31.0 +/- 8.2, respectively) vs. pre-vibration (30.2 +/- 8.6, 30.3 +/- 8.1, 30.2 +/- 8.3, respectively), but remained unchanged in CP (30.6 +/- 8.3 immediately-post, 30.7 +/- 8.2 at 15 min vs. 30.4 +/- 8.2 pre-vibration). In the frequency study, flexibility was improved (p < 0.01) immediately-post in VP15, VP20, VP30 (31.5 +/- 5.2, 31.3 +/- 5, 31.7 +/- 5.3, respectively) and at 15 min recovery (31.3 +/- 5.4, 31.3 +/- 5.0, 31.3 +/- 5.3, respectively) vs. pre-vibration (30.6 +/- 5.4, 30.2 +/- 5.7, 30.3 +/- 5.9, respectively), but not in CP (30.7 +/- 5.1 immediately-post, 30.6 +/- 5 at 15 min vs. pre-vibration 30.5 +/- 5.7). There were no significant effects of amplitude or frequency on SJ. In conclusion, a single WBV bout using a side-to-side alternating vibration plate may increase flexibility which persists for at least 15 min, without altering jumping performance. These effects were observed irrespective of frequency and amplitude. (C) 2009 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved

    Membrane-associated epithelial cell adhesion molecule is slowly cleaved by -secretase prior to efficient proteasomal degradation of its intracellular domain.

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    Regulated intramembrane proteolysis (RIP) is a key mechanism for activating transmembrane proteins such as epithelial cell adhesion molecule (EpCAM) for cellular signaling and degradation. EpCAM is highly expressed in carcinomas and progenitor and embryonic stem cells and is involved in the regulation of cell adhesion, proliferation, and differentiation. Strictly sequential cleavage of EpCAM through RIP involves initial shedding of the extracellular domain by -secretase (ADAM) and -secretase (BACE) sheddases, generating a membrane-tethered C-terminal fragment EpCTF. Subsequently, the rate-limiting -secretase complex catalyzes intramembrane cleavage of EpCTF, generating an extracellular EpCAM-A-like fragment and an intracellular EpICD fragment involved in nuclear signaling. Here, we have combined biochemical approaches with live-cell imaging of fluorescent protein tags to investigate the kinetics of -secretase-mediated intramembrane cleavage of EpCTF. We demonstrate that -secretase-mediated proteolysis of exogenously and endogenously expressed EpCTF is a slow process with a 50% protein turnover in cells ranging from 45 min to 5.5 h. The slow cleavage was dictated by -secretase activity and not by EpCTF species, as indicated by cross-species swapping experiments. Furthermore, both human and murine EpICDs generated from EpCTF by -secretase were degraded efficiently (94-99%) by the proteasome. Hence, proteolytic cleavage of EpCTF is a comparably slow process, and EpICD generation does not appear to be suited for rapidly transducing extracellular cues into nuclear signaling, but appears to provide steady signals that can be further controlled through efficient proteasomal degradation. Our approach provides an unbiased bioassay to investigate proteolytic processing of EpCTF in single living cells
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