While the use of location-based augmented reality (AR) for education has demonstrated benefits on participants’ motivation, engagement, and on their physical activity, geolocation data inaccuracy ...causes augmented objects to jitter or drift, which is a factor in downgrading user experience. We developed a free and open source web AR application and conducted a comparative user test (n = 54) in order to assess the impact of geolocation data on usability, exploration, and focus. A control group explored biodiversity in nature using the system in combination with embedded GNSS data, and an experimental group used an external module for RTK data. During the test, eye tracking data, geolocated traces, and in-app user-triggered events were recorded. Participants answered usability questionnaires (SUS, UEQ, HARUS).We found that the geolocation data the RTK group was exposed to was less accurate in average than that of the control group. The RTK group reported lower usability scores on all scales, of which 5 out of 9 were significant, indicating that inaccurate data negatively predicts usability. The GNSS group walked more than the RTK group, indicating a partial effect on exploration. We found no significant effect on interaction time with the screen, indicating no specific relation between data accuracy and focus. While RTK data did not allow us to better the usability of location-based AR interfaces, results allow us to assess our system’s overall usability as excellent, and to define optimal operating conditions for future use with pupils.
A cognitive model of how teachers plan instruction was validated in laboratory settings but remained to be tested empirically in authentic situations. The objective of this work is to describe and ...compare pedagogical reasoning in laboratory and authentic contexts and across expertise levels. The "state-driven hypothesis" and the "knowledge-driven hypothesis" were used in two studies to show how pedagogical reasoning was performed by novices and experts in laboratory (n = 18) and in authentic context (n = 14). Globally, the results show (1) similarities and differences in how pedagogical reasoning unfolds in laboratory and authentic contexts and (2) how domain knowledge influences only some aspects of this process. The work presented lays the foundations for the fine-grained study of how domain knowledge determines problem-solving in pedagogical-reasoning.
Research on help seeking with a computer coach providing on-demand help has not produced fully adequate models of the process from a cognitive perspective. The present study postulates a model of ...help seeking from a cognitive perspective and tests this model in a learning situation characterized as problem-based and computer-supported. The participants were 18 graduate students from the faculty of Education of a Canadian university. Their participation involved solving a complex problem in statistics, in pairs, with the help of a computer coach, the McGill statistics tutor. Analysis of the performance data was performed using directed probability graphs and the log-linear approach. Results show that the model is reflected in the data. Implications for the design of computer coaches and instructional situations are discussed.
Despite their intellectual potential, students with learning disabilities (LDs) face enormous challenges in science. Drawing on the literature from special, inclusive, and science education, this ...paper illuminates the promises and challenges of supporting students with LDs in science, technology, engineering, and mathematics (STEM) education. In light of the insights from research in these diverse fields, this work offers a comprehensive framework to understand and address the unique needs of students with LDs in STEM learning. This multidimensional analysis provides an overview of the contemporary discourses on STEM education, presents the continuing controversies surrounding the conceptualization of LDs, and discusses the barriers to the inclusion of students with LDs in science classrooms. Because difficulties in cognitive processing are thought to underlie LDs, this paper particularly focuses on the cognitive impediments to the achievement of students with LDs in problem-based STEM learning tasks and shares effective interventions to support these students' cognitive development.
Malgré leur potentiel intellectuel, les élèves ayant des troubles d'apprentissage (TA) connaissent de grandes difficultés en sciences. S'appuyant sur la littérature consacrée à l'éducation spécialisée, à l'inclusion scolaire et à l'enseignement des sciences, cet article met en relief les efforts prometteurs et les difficultés de l'aide aux élèves ayant des TA dans les domaines des STIM : sciences, technologie, ingénierie et mathématiques. À la lumière des connaissances résultant de la recherche dans ces domaines variés, ce travail fournit un cadre complet pour la compréhension des besoins uniques des élèves ayant des TA dans l'apprentissage de STIM, ainsi que des solutions. Cette analyse multidimensionnelle fournit un aperçu des discours contemporains sur l'enseignement des STIM, présente les polémiques actuelles au sujet de la conceptualisation des TA et les obstacles à l'inclusion des élèves ayant des TA dans les classes de sciences. En raison du dysfonctionnement cognitif qui serait à l'origine des TA, cet article se penche en particulier sur les obstacles à la réussite des élèves ayant des TA pour les tâches d'apprentissage des STIM basées sur la résolution de problèmes, et fait part d'interventions efficaces pour favoriser leur développement cognitif.
Biofumigation of peaches in shipping cartons with pads containing culture of the volatile-producing fungus
Muscodor albus was investigated for the control of brown rot caused by
Monilinia fructicola. ...Biofumigation during cold storage (1–2
°C) with 50 or 200
g of
M. albus per plastic bag and enclosed carton containing 14
kg of fruit reduced the incidence of brown rot significantly (
P
<
0.05) with ‘Coronet’ and ‘Red Globe’ peaches and disease incidence was comparable or lower (
P
<
0.05) than decay in fungicide-treated peaches. Biofumigation was not as effective in non-bagged cartons, although significant brown rot control was observed in ‘Red Globe’ peaches with the 200-g treatment. Containment of volatile compounds in the cartons is thus important for the efficacy of this treatment in cold storage.
Control of postharvest lemon diseases by biofumigation with the volatile-producing fungus
Muscodor albus was investigated. In vitro exposure to
M. albus volatile compounds for 3 days killed
...Penicillium digitatum and
Geotrichum citri-aurantii, causes of green mold and sour rot of lemons, respectively. Lemons were wound-inoculated with
P. digitatum and placed in closed 11-L plastic boxes with rye grain cultures of
M. albus at ambient temperature. There was no contact between the fungus and the fruit. Biofumigation for 24–72
h controlled green mold significantly, even when treatment began 24
h after inoculation. Effectiveness was related to the amount of
M. albus present. In tests conducted inside a 11.7-m
3 degreening room with 5
ppm ethylene at 20
°C, green mold incidence on lemons was reduced on average from 89.8 to 26.2% after exposure to
M. albus for 48
h. Ethylene accelerates color development in harvested citrus fruit.
M. albus had no effect on color development. Biofumigation in small boxes immediately after inoculation controlled sour rot, but was ineffective if applied 24
h later.
G. citri-aurantii may be less sensitive to the volatile compounds than
P. digitatum or escapes exposure within the fruit rind. Biofumigation with
M. albus could control decay effectively in storage rooms or shipping packages.
Dyslexia is a phenomenon for which the brain correlates
have been studied since the beginning of the 20th century. Simultaneously, the
field of education has also been studying dyslexia and its ...remediation, mainly
through behavioral data. The last two decades have seen a growing interest in
integrating neuroscience and education. This article provides a quick overview
of pertinent scientific literature involving neurophysiological data on
functional brain differences in dyslexia and discusses their very limited
influence on the development of reading remediation for dyslexic individuals.
Nevertheless, it appears that if certain conditions are met - related to
the key elements of educational neuroscience and to the nature of the research
questions - conceivable benefits can be expected from the integration of
neurophysiological data with educational research. When neurophysiological data
can be employed to overcome the limits of using behavioral data alone,
researchers can both unravel phenomenon otherwise impossible to document and
raise new questions.
The induction and maintenance of resistance to gray mold rot (Botrytis cinerea) in tomato fruit during storage, exposed to hormic dose of UV-C (3.7 kJ/m2) was studied. Treated fruit were more ...susceptible to disease immediately after treatment, but thereafter, they became gradually resistant and the resistance was maintained until the end of the storage period of 35 d. Pre-storage treatment of tomato with the hormic UV dose-induced synthesis and accumulation of rishitin. This accumulation was gradual and reached a maximum level (46.23 mg/kg) by 15 d after treatment before the rishitin level declined to 3.5 mg/kg at the end of storage. Inoculation of untreated fruit also induced rishitin accumulation but this response was much higher in UV-treated fruit. In both control and UV-treated fruit, the capacity to accumulate rishitin declined with ripening. There was a significant correlation between rishitin accumulation in UV-treated fruit both before and after inoculation and disease resistance. The enhanced disease susceptibility immediately after treatment is likely the result of transient but severe oxidative stress-induced by both UV and inoculation. Subsequent gradual resistance observed in treated fruit during the early period of storage could be attributed to the accumulation of rishitin both before and after inoculation. The level of rishitin present at the time of inoculation appears to be the primary factor in the expression of resistance while its accumulation after inoculation appears to play a reinforcing role in resistance. However, rishitin level cannot account for the observed prolonged resistance of UV-treated tomato to gray mold rot, and it is suggested that other induced defenses might also be involved.
Characterisation and modelling of aging of composites Mercier, Julien; Bunsell, Anthony; Castaing, Philippe ...
Composites. Part A, Applied science and manufacturing,
01/2008, Letnik:
39, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The aim of this study was to better understand the aging of glass fibre–epoxy composites exposed to water and loading and to predict effects on structure lifetimes. Diffusion was investigated by ...gravimetric methods to determine sorption kinetics for different conditions. Fickian diffusion was observed. Decreases of mechanical properties as a function of diffusion were observed. Damage by cracking and the coupling with water uptake were then studied. A model taking into account effects due to water and/or mechanical loading is proposed which allows the continuous evolution of rigidity during aging to be predicted at all stages of water absorption and matrix cracking.
An integrated approach was evaluated that combined biological and chemical fumigation of table grapes to control postharvest gray mold caused by
Botrytis cinerea. After fumigation of the grapes with ...ozone or sulfur dioxide during pre-cooling, the fruit were then exposed to continuous biofumigation by the volatile-producing fungus
Muscodor albus during storage. Biofumigation was provided by in-package generators containing a live grain culture of the fungus. This grain formulation of
M. albus survived the initial ozone or sulfur dioxide fumigation, but sulfur dioxide reduced its production of isobutyric acid, an indicator of the production of antifungal volatiles. Gray mold incidence was reduced among inoculated ‘Autumn Seedless’ grapes from 91.7 to 19.3% by 1
h fumigation with 5000
μL
L
−1 ozone, and further reduced to 10.0% when ozone fumigation and
M. albus biofumigation were combined. The natural incidence of gray mold among organically grown ‘Thompson Seedless’ grapes after 1 month of storage at 0.5
°C was 31.0%. Ozone fumigation and
M. albus biofumigation reduced the incidence of gray mold to 9.7 and 4.4, respectively, while the combined treatment reduced gray mold incidence to 3.4%. The use of commercial sulfur dioxide pads reduced the incidence to 1.1%. The combination of ozone and
M. albus controlled decay significantly, but was less effective than the standard sulfur dioxide treatments. Although less effective than sulfur dioxide treatment, ozone and
M. albus controlled decay significantly, and could be alternatives to sulfur dioxide, particularly for growers complying with organic production requirements.
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