286 research outputs found
Behavior Effect of Hint Selection Penalties and Availability in an Intelligent Tutoring System
Proceedings of: Tenth International Confererence on Intelligent Tutoring Systems: Bridges to Learning (ITS 2010). Pittsburg, USA, June 14-18, 2010.his paper presents empirical results about the behavior effect of two different hinting strategies applied on exercises within an ITS: having some penalty on the scoring for viewing hints or not having any effect on the scoring; and hints directly available or only available as a result to an incorrect attempt. We analyze the students' behavior differences when these hinting techniques changed, taking into account the type and difficulty of the presented exercises.Work partially funded by the Learn3 project TIN2008-05163/TSI within the Spanish âPlan Nacional de I+D+Iâ, and the Madrid regional community project eMadrid S2009/TIC-1650.Publicad
Long-Term Adherence to IFN Beta-1a Treatment when Using RebiSmartÂź Device in Patients with Relapsing-Remitting Multiple Sclerosis
The effectiveness of disease-modifying drugs in the treatment of multiple sclerosis is associated with adherence. RebiSmart (R) electronic device provides useful information about adherence to the treatment with subcutaneous (sc) interferon (IFN) beta-1 alpha (Rebif (R)). The aim of the study was to determine long-term adherence to this treatment in patients with relapsing-remitting multiple sclerosis (RRMS). This retrospective multicentre observational study analysed 258 patients with RRMS who were receiving sc IFN beta-1 alpha (Rebif (R)) treatment by using RebiSmart (R) until replacement (36 months maximum lifetime) or treatment discontinuation. Adherence was calculated with data (injection dosage, time, and date) automatically recorded by RebiSmart (R). Patients in the study had a mean age of 41 years with a female proportion of 68%. Mean EDSS score at start of treatment was 1.8 (95% CI, 1.6-1.9). Overall adherence was 92.6%(95% CI, 90.6-94.5%). A total of 30.2% of patients achieved an adherence rate of 100%, 80.6% at least 90%, and only 13.2% of patients showed a suboptimal adherence (<80%). A total of 59.9% of subjects were relapse-free after treatment initiation. Among 106 subjects (41.1%) who experienced, on average, 1.4 relapses, the majority were mild (40.6%) or moderate (47.2%). Having experienced relapses from the beginning of the treatment was the only variable significantly related to achieving an adherence of at least 80% (OR = 3.06, 1.28-7.31). Results of this study indicate that sc IFN beta-1 alpha administration facilitated by RebiSmart (R) could lead to high rates of adherence to a prescribed dose regimen over 36 months
Obstructive Sleep Apnoea Syndrome, Endothelial Function and Markers of Endothelialization. Changes after CPAP
STUDY OBJECTIVES: This study tries to assess the endothelial function in vivo using flow-mediated dilatation (FMD) and several biomarkers of endothelium formation/restoration and damage in patients with obstructive sleep apnoea (OSA) syndrome at baseline and after three months with CPAP therapy. DESIGN: Observational study, before and after CPAP therapy. SETTING AND PATIENTS: We studied 30 patients with apnoea/hypopnoea index (AHI) >15/h that were compared with themselves after three months of CPAP therapy. FMD was assessed non-invasively in vivo using the Laser-Doppler flowmetry. Circulating cell-free DNA (cf-DNA) and microparticles (MPs) were measured as markers of endothelial damage and the vascular endothelial growth factor (VEGF) was determined as a marker of endothelial restoration process. MEASUREMENTS AND RESULTS: After three month with CPAP, FMD significantly increased (1072.26 ± 483.21 vs. 1604.38 ± 915.69 PU, p< 0.005) cf-DNA and MPs significantly decreased (187.93 ± 115.81 vs. 121.28 ± 78.98 pg/ml, p<0.01, and 69.60 ± 62.60 vs. 39.82 ± 22.14 U/ΌL, p<0.05, respectively) and VEGF levels increased (585.02 ± 246.06 vs. 641.11 ± 212.69 pg/ml, p<0.05). These changes were higher in patients with more severe disease. There was a relationship between markers of damage (r = -0.53, p<0.005) but not between markers of damage and restoration, thus suggesting that both types of markers should be measured together. CONCLUSIONS: CPAP therapy improves FMD. This improvement may be related to an increase of endothelial restoration process and a decrease of endothelial damage
Expansion of CD8+CD57+ T Cells in an Immunocompetent Patient with Acute Toxoplasmosis
CD57+ T cells increase in several viral infections like cytomegalovirus, herpesvirus, parvovirus, HIV and hepatitis C virus and are associated with several clinical conditions related to immune dysfunction and ageing. We report for the first time an expansion of CD8+ CD57+ T cells in a young patient with an acute infection with Toxoplasma gondii. Our report supports the concept that CD8+ CD57+ T cells could be important in the control of chronic phase of intracellular microorganisms and that the high numbers of these cells may reflect the continuing survey of the immune system, searching for parasite proliferation in the tissues
PReS-FINAL-2274: Antiadalimumab antibodies in pediatric rheumatology patients. A pilot experience
Do optional activities matter in virtual learning environments?
Virtual Learning Environments (VLEs) provide students with activi-ties to improve their learning (e.g., reading texts, watching videos or solving exercises). But VLEs usually also provide optional activities (e.g., changing an avatar profile or setting goals). Some of these have a connection with the learn-ing process, but are not directly devoted to learning concepts (e.g., setting goals). Few works have dealt with the use of optional activities and the relation-ships between these activities and other metrics in VLEs. This paper analyzes the use of optional activities at different levels in a specific case study with 291 students from three courses (physics, chemistry and mathematics) using the Khan Academy platform. The level of use of the different types of optional ac-tivities is analyzed and compared to that of learning activities. In addition, the relationship between the usage of optional activities and different student be-haviors and learning metrics is presented
Photoluminiscence enhancement in quaternay III-nitrides alloys grown by molecular beam epitaxy with increasing Al content
Room temperature photoluminescence and optical absorption spectra have been measured in wurtzite InxAlyGa1âxâyN (x ⌠0.06, 0.02<y<0.27) layers grown by molecular beam epitaxy. Photoluminescence spectra show both an enhancement of the integrated intensity and an increasing Stokes shift with the Al content. Both effects arise from an Al-enhanced exciton localization revealed by the S- and W-shaped temperature dependences of the photoluminescence emission energy and bandwidth, respectively. Present results point to these materials as a promising choice for the active region in efficient light emitters. An In-related bowing parameter of 1.6âeV was derived from optical absorption data
Efficacy and efficiency of a new therapeutic approach based on activity-oriented proprioceptive antiedema therapy (TAPA) for edema reduction and improved occupational performance in the rehabilitation of breast cancer-related arm lymphedema in women: a controlled, randomized clinical trial
Background: Breast cancer (BC) is a major public health issue. More than one out of five women treated for breast cancer will develop lymphedema in an upper extremity. Current evidence advocates transdisciplinary oncological rehabilitation. Therefore, research in this area is necessary since limited consensus having been reached with regard to the basic essential components of this rehabilitation. Consensus has, however, been reached on the use of decongestive lymphedema therapy (DLT), but due to a lack of tests, the necessary dosages are unknown and its level is moderately strong. This study attempts to verify both the efficacy of activity-oriented proprioceptive antiedema therapy (TAPA), as compared to conventional treatments such as DLT or Complex Physical Therapy (CPT), as well as its efficiency in terms of cost-effectiveness, for patients affected by breast cancer-related arm lymphedema. Methods: Controlled, randomized clinical trial with dual stratification, two parallel arms, longitudinal and single blind. 64 women with breast cancer-related arm lymphedema will take part in the study. The experimental group intervention will be the same for stage I and II, and will consist of neuro-dynamic exercises oriented to the activity, proprioceptive neuromuscular facilitation activities and proprioceptive anti-edema bandaging. The control group intervention, depending on the stage, will consist of preventive measures, skin care and exercise-prescribed training in the lymphedema workshop as well as compression garments (Stage I) or conservative Complex Decongestive Therapy treatment (skin care, multi-layer bandaging, manual lymphatic drainage and massage therapy) (Stage II). Results: Sociodemographic and clinical variables will be collected for the measurement of edema volume and ADL performance. Statistical analysis will be performed on intent to treat. Discussion: It has been recommended that patient training be added to DLT, as well as a re-designing of patient lifestyles and the promotion of health-related aspects. In addition, clinical trials should be undertaken to assess neural mobilization techniques and proprioceptive neuromuscular facilitation should be included in the therapy. Cohesive bandaging will also be performed as an early form of pressotherapy. The proposed study combines all of these aspects in order to increased comfort and promote the participation of individuals with lymphedema in everyday situations. Limitations: The authors have proposed the assessment of the experimental treatment for stages I and II. One possible limitation is the lack of awareness of whether or not this treatment would be effective for other stages as well as the concern for proper hand cleansing during use of bandages, given the current COVID-19 pandemic situation. Trial registration: This trial was registered in ClinicalTrials.gov (NCT03762044). Date of registration: 23 November 2018. Prospectively Registered
Aluminium incorporation in AlGaN/GaN heterostructures: a comparative study by ion beam analysis and X-ray diffraction
The Al content in AlxGa1 â xN/GaN heterostructures has been determined by X-ray diffraction (XRD) and contrasted with absolute measurements from ion beam analysis (IBA) methods. For this purpose, samples with 0.1bxb0.3 grown by metal organic chemical vapour deposition on sapphire substrates have been studied. XRD and IBA corroborate the good epitaxial growth of the AlGaN layer, which slightly deteriorates with the incorporation of Al for xN0.2. The assessment of Al incorporation by XRD is quite reliable regarding the average value along the sample thickness. However, XRD analysis tends to overestimate the Al fraction at low contents, which is attributed to the presence of strain within the layer. For the highest Al incorporation, IBA detects a certain Al in-depth compositional profile that should be considered for better XRD data analysis
InïŹuence of steering effects on strain detection in AlGaInN/GaN heterostructures by ion channellin
Ion steering effects in the interface of heterostructures can strongly influence the shape and position of angular channelling scans leading to considerable error in the determination of strain by ion channelling. As an example, this paper presents channelling measurements on a near-lattice-matched AlGaInN/GaN heterostructure which show no shift between the angular scans from the quaternary layer and the underlying GaN substrate although high resolution x-ray diffraction data confirm the presence of strain in the layer. Such âanomalousâ behaviour was studied by means of Monte Carlo simulations for nitride ternary and quaternary films in the whole composition range. The simulations show that the thickness, magnitude of the distortion of the strained lattice and energy of the probing beam are critical parameters controlling the impact of steering. Three composition/strain regions were established for a typical beam of 2MeV alpha particles corresponding to different intensities of the steering potential and in which strain measurements by ion channelling are (a) correct, (b) possible but require corrections and (c) not possible due to steering effects
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