According to EC regulations the deliberate release of genetically modified (GM) crops into the agro-environment needs to be accompanied by environmental monitoring to detect potential adverse ...effects, e.g.unacceptable levels of gene flow from GM to non-GM crops, or adverse effects on single species or species groups thus reducing biodiversity. There is, however, considerable scientific and public debate on how GM crops should be monitored with sufficient accuracy, discussing questions of potential adverse effects, agro-environmental variables or indicators to be monitored and respective detection methods; Another basic component, the appropriate number and location of monitoring sites, is hardly considered. Currently, no consistent GM crop monitoring approach combines these components systematically. This study focuses on and integrates spatial agro-environmental aspects at a landscape level in order to design monitoring networks. Based on examples of environmental variables associated with the cropping of Bt-Maize (Zea maize L.), herbicide-tolerant (HT) winter oilseed rape (Brassica napus L.), HT sugar beet (Beta vulgaris L.), and starch-modified potato (Solanum tuberosum L.), we develop a transferable framework and assessment scheme that comprises anticipated adverse environmental effects, variables to be measured and monitoring methods.These we integrate with a rule-based GIS (geographic information system) analysis, applying widely available spatial area and point information from existing environmental networks. This is used todevelop scenarios with optimised regional GM crop monitoring networks.
Introduction: Computer‐aided learning (CAL) is a viable alternative to traditional teaching methods. While CAL is used for teaching only, computer‐aided testing (CAT) can be applied as a ...computer‐based examination method. The aim of the present study was to evaluate students’ attitude towards CAT as compared to written multiple choice tests.
Materials and methods: Forty‐one undergraduate dental students underwent a mock examination consisting of 15 written multiple choice questions and 15 questions delivered using the interactive MobiTed® system. A questionnaire based on an eight‐item seven‐point Likert scale was used to evaluate the students’ attitude towards CAT. The students’ performance in both tests was analysed using paired t‐tests. Correlations between test performance and questionnaire were expressed by Pearson correlation coefficients.
Results: Despite study‐design‐related differences, students’ test performance between written multiple choice and MobiTed® was comparable. No correlations between test results and questionnaire could be set up. Students rated MobiTed® to be equivalent to written multiple choice and had no difficulties with the CAT set up. The pre‐defined sequence of questions with each question being shown only once was considered to be a major disadvantage of the CAT system. Complex questions should be displayed longer compared to short questions.
Discussion: Computer‐aided testing appeared to be equivalent to written multiple choice tests not only in terms of student performance but also to their perception. This is consistent with previous studies.
Conclusions: Interactive multiple choice tests may provide an alternative to written tests, but should allow examinees to have control over the sequence, as well as the length of time the questions are displayed.
Soil water availability is most essential in the Sahelian agriculture but is hampered by several factors. Surface crusts or crust-like surfaces, which are characteristic of most Sahelian soils, have ...been shown to decrease water infiltrability and increase runoff. Their type and structure are influenced by soil texture, vegetation cover, erosion and deposition effects of wind and water. A soil and terrain survey in semi-arid SW-Niger was carried out to explain the patterns of soil surface crusts and the deterioration of the land. The soil surface crusts were shown to depend also on specific terrain factors including land use type and intensity, and terrain type and position. Chemical and physical soil factors such as organic carbon, soil colour and texture occurring with specific crusts indicate soil degradation, especially in sloping terrain, which increases runoff and soil erosion. For sandy soils, surface tillage is required to break up the crusts. Higher surface organic matter is recommended to enhance water infiltration in soils.
There are various types of grain storage bags available to farmers in tropical countries. However, these bags differ in price, quality, and reduced post-harvest losses due to insect pests and mould ...infestation. This study aimed to compare the effectiveness of three types of storage bags of Purdue Improved Crop Storage (PICS), Grain pro-super (GPS) and woven (WN) bags under assumed small farmer’s storage practices in the sub-tropical climatic conditions. The practice of weekly routine opening of the bags was compared with the recommended practice of keeping the bags closed for at least 3 months. Under laboratory experiment, insect population, moisture content, grain humidity, and temperature were measured at the weekly intervals while under farmer’s setting, moisture content (%) of maize and percentage of insect damage were measured after 3 and 6 months of storage at the farmer’s homestead. Considering the routine weekly opening effect, the PICS bag kept a low grain humidity average (56.6%) compared to the Grain pro-super bag (64.2%) and Woven bag (71.5%). The PICS bag reduced the insect population to an average of zero (0.4) compared to GPS (6.5) and the WN (14.8). Under farmer’s conditions, the mean difference in the percentage of insect damage between the PICS and GPS were insignificant (P > 0.05) at both 3 and 6 months of storage, and the insect damage throughout decreased with time. The results of this study indicate that PICS bag may support positively the practice of routine weekly opening compared to the GPS and WN in the sub-tropical climatic conditions.
•Weekly routine opening practice affects differently the bags of maize during storage.•Hermetic bags reduces the live weevils at 3 and 6 months of storage of maize.•Purdue Improved Crop Storage bags supports weekly routine opening practice of maize.
Patients with traumatic brain injury (TBI) and long-bone fractures can show increased callus formation. This effect has already been reproduced in wild-type (wt) mice. However, the mechanisms remain ...poorly understood. Leptin is significantly increased following TBI, while its role in bone healing remains unclear. The aim of this study was to evaluate fracture healing in leptin-deficient ob/ob mice and to measure any possible impact of TBI on callus formation. 138 female, 12 weeks old, ob/ob mice were divided into four groups: Control, fracture, TBI and combined trauma. Osteotomies were stabilized with an external fixator; TBI was induced with Controlled Cortical Impact Injury. Callus bridging was weekly evaluated with in vivo micro-CT. Biomechanical testing was performed ex vivo. Micro-CT showed high non-union rates after three and four weeks in the fracture and combined trauma group. No differences were observed in callus volume, density and biomechanical properties at any time point. This study shows that bony bridging is impaired in the present leptin-deficient trauma model. Furthermore, the phenomenon of increased callus formation after TBI could not be reproduced in ob/ob mice, as in wt mice. Our findings suggest that the increased callus formation after TBI may be dependent on leptin signaling.
Statement of problem There is less information on the quality of fit of zirconia frameworks with or without ceramic veneer than on anatomically contoured milled zirconia restorations. Purpose The ...purpose of this in vitro study was to evaluate the strain development of CAD/CAM fabricated zirconia ceramic frameworks with and without ceramic veneering, copy-milled zirconia ceramic frameworks, and copy-milled zirconia ceramic anatomic contour restorations. Material and methods Four groups of 3-unit implant-supported cement-retained restorations were fabricated (n=10) to fit an in vitro model with 2 implants. Strain gauges which recorded the strain development of all restorations during cementation were attached to the model mesially and distally adjacent to the implants. Mean absolute strain values were recorded for statistical analysis (MANOVA with Pillai's trace; α=.05). Results Mean absolute strain development at the different strain gauge locations ranged from 83.23 µm/m for copy-milled zirconia ceramic anatomic contour restorations to 301.20 µm/m for veneered CAD/CAM fabricated zirconia ceramic restorations. Significant effects ( P <.001) of the fixed factors restoration type and veneering status, as well as of their interaction term ( P =.001) were found. Ceramic veneering of CAD/CAM frameworks resulted in higher strain development, whereas the greater volume in copy-milled anatomic contour restorations did not affect accuracy. Conclusions With the systems used in this study, zirconia ceramic-based anatomic contour restorations show greater passivity of fit than ceramic veneered CAD/CAM fabricated zirconia ceramic frameworks. (J Prosthet Dent 2012;107:232-238)
