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Online interactive systems offer the beguiling prospect of an improved environment for learning at minimum extra cost. We have developed online interactive tutorials that adapt the learning environment to the current learning status of each individual student. These Adaptive Tutorials (ATs) modify the tasks given to each student according to their previous responses. Feedback, assessment and remediation are also adapted. Over a three-year period we progressively blended ATs into notoriously challenging courses in introductory Engineering Mechanics. We assessed the impact of this initiative by reviewing three lines of data: (i) the built-in diagnostics of the system, (ii) changes in student grades from year-to-year and (iii) supplementary surveys. Generally, students liked the new blended system and grades improved. Detailed analysis revealed nuances in the measures of student learning, such as differences between high-performing and low-performing students. With these insights we are able to further adapt the system to meet the learning needs of our students. [ABSTRACT FROM AUTHOR]

Four locally available biodegradable substrates—sugarcane (Saccharum officinales) bagasse, palm (Borasus flabellifera) leaf, coconut (Cocos nucifera) leaf, and bamboo (Bambusa bambos) mat—were evaluated for the production of periphyton and a polyculture of rohu (Labeo rohita) and common carp (Cyprinus carpio) in poultry-manured ponds. Chlorophyll-a, phaeophytin-a, and total pigment content of periphyton were not significantly different (P > 0.05) among substrate types. Dry matter and ash-free dry matter of coconut leaf periphyton were significantly higher (P < 0.05) than that of the other substrates. All four substrates induced significantly (P < 0.05) higher growth, production, and survival of rohu and common carp. Among the substrates used, coconut leaf was more effective in enhancing fish production. [ABSTRACT FROM PUBLISHER]

Ten locally available substrates, five biodegradable and five non-degradable, were evaluated for their potential to harbor periphyton in cement tanks fertilized with poultry manure. The tanks were fertilized regularly and the periphyton was allowed to grow for 70 days. Weekly samples of periphyton and plankton were collected for enumeration and biochemical analyses. Among the substrates, earthen tiles harbored negligible amount of periphyton. The phytoperiphyton genera encountered on the substrate belonged mainly to Chlorophyceae (14 genera), followed by Cyanophyceae (2 genera), Chrysophyceae (1 genus), Bacillariophyceae (1 genus), and Dinophyceae (1 genus). Nauplius, Keratella, Diaptomus, Cyclops, Moina, Chironomus and insect eggs were the zooplankton encountered on substrates. Phytoplankton density was higher on tyre (86,426 cells or colonies/cm²) and palm leaf (85,808 cells or colonies/cm²) and lowest on ceramic tile (21,081 cells or colonies/cm²). Glass plates harbored the highest number of zooplankton species per unit area (1050 cells or colonies/cm²), while arecanut leaf-sheath had the lowest (210 cells or colonies/cm²). All five families of phytoplankton present on the substrates were also present in tank water. While periphyton contained 26 genera, tank water had only 24. Periphytic dry matter, ash, ash-free dry matter, plankton density on substrates and water showed a general increase with respect to time. Polyvinyl chloride (PVC) (0.972 mg/cm²), glass (0.913 mg/cm²), and bamboo (0.897 mg/cmsup2;) had higher periphytic dry matter and ceramic tile (0.262 mg/cm²) the lowest. All the proximate composition parameters of periphyton, except nitrogen free extract (NFE) varied significantly (P < 0.05) between the substrates. The moisture content of periphyton ranged from 85.58% (bamboo) to 95.27% (arecanut leaf-sheath). Crude protein was high in periphyton from bamboo (3.77%) and tyre (3.66%) and low in that from arecanut leaf-sheath (0.99%). [ABSTRACT FROM AUTHOR]

Rohu, Labeo rohita, fingerlings (av. wt. 1.6 g) were fed pelleted diets supplemented with 0, 0.5, 1.0, 1.5 and 2.0% sodium chloride (NaCl) for 120 days in 25-m3 cement tanks. The final weight gain of fish fed 0.5 and 1.0% NaCl incorporated diets was significantly (P < 0.05) higher than that of the control (0% NaCl). Net protein retention and carcass protein and fat contents were higher under different treatments as compared to the control. Growth indices and carcass composition indicate inclusion of 1.0% NaCl in the diet to be beneficial for growth promotion in rohu. [ABSTRACT FROM PUBLISHER]

Periphyton development on bamboo substrate was quantified over six weeks in fertilized mud-bottomed cement tanks. Dry matter, ash and pigment content of periphyton were analyzed at weekly intervals. On dry matter basis, periphyton production reached the maximum on the 21st day and showed a decline thereafter. Periphyton was scraped and fed ad libitum daily over 30 days to fingerlings of cultivable carps (catla, rohu, mrigal, common carp, grass carp and mahseer) and hybrid red tilapia maintained in aerated fibreglass tanks, to evaluate digestibility. Dry matter digestibility was highest (P < 0.05) with mahseer (42.54%) and lowest with catla (20.63%). The values obtained with grass carp, red tilapia, rohu, and mrigal were not significantly different from that of mahseer and common carp. Protein digestibility was highest in grass carp (71.21%) and lowest in common carp (48.81%). Further, protein digestibility in catla, rohu and mrigal was similar. The results of this study would be useful in the selection of fish species for periphytonbased aquaculture. [ABSTRACT FROM PUBLISHER]

Periphyton development on bamboo substrate was quantified over six weeks in fertilized mud-bottomed cement tanks. Dry matter, ash and pigment content of periphyton were analyzed at weekly intervals. On dry matter basis, periphyton production reached the maximum on the 21st day and showed a decline thereafter. Periphyton was scraped and fed ad libitum daily over 30 days to fingerlings of cultivable carps (catla, rohu, mrigal, common carp, grass carp and mahseer) and hybrid red tilapia maintained in aerated fibreglass tanks, to evaluate digestibility. Dry matter digestibility was highest (P < 0.05) with mahseer (42.54%) and lowest with catla (20.63%). The values obtained with grass carp, red tilapia, rohu, and mrigal were not significantly different from that of mahseer and common carp. Protein digestibility was highest in grass carp (71.21%) and lowest in common carp (48.81%). Further, protein digestibility in catla, rohu and mrigal was similar. The results of this study would be useful in the selection of fish species for periphytonbased aquaculture. [ABSTRACT FROM PUBLISHER]