Intelligent Tutoring Tools in a Computer Integrated Learning Environment for introductory numeric disciplines

Research in the field of Intelligent Tutoring Systems has failed to provide any substantial or viable systems that could be used in real academic environments. This situation appears to be the result of two factors: first, the failure to identify clearly the objectives and the scope of such systems; and second, the continuously shifting technological platform on which such systems are built. This paper examines the possible objectives for the development of tutoring systems and presents an approach adopted by the Byzantium project. It describes a model of computer integrated learning environment (CILE) and discusses the role of an intelligent tutoring tool (ITT) within this model. The paper also considers the potential of the Internet for various learning environments. Based on our experience of designing and implementing four ITTs that have the same look and feel (but which address diverse subject areas) the paper suggests a possible extension of the Byzantium approach to the Internet through the conversion of ITTs into intelligent tutoring applets (ITAs)

Human Mononuclear Phagocyte Kinetics in Health and Inflammation

The mononuclear phagocyte system comprises three types of cells:: monocytes, macrophages and dendritic cells (DC). The kinetics underlying their generation, differentiation and disappearance are critical to understanding how these cells maintain tissue homeostasis as well as orchestrating the immune response. Currently, the circulating kinetics of these cells remain unknown in humans. The kinetic profiles of circulating monocyte subsets (classical, intermediate and non-classical) and DC subsets (pDC, pre-DC, cDC1 and cDC2) were examined in humans for the first time using stable isotope labelling in the form of deuterated glucose. Monocyte subsets appeared sequentially in the circulation which was demonstrated to be due to a developmental relationship between these cells. Pre-DC and cDC appeared prior to monocytes whereas pDC were observed later. After establishing the turnover of circulating mononuclear phagocytes under steady physiological conditions, the kinetics were then examined following experimental human endotoxemia. A temporary loss of circulating mononuclear phagocytes was observed at early time points, classical monocytes were the first to re-appear within the circulation due to an early emergency release from the bone marrow. Finally, in a human model of local inflammation, the infiltrating kinetics of monocyte and DC subsets were examined in the skin. Particularly, pre-DC were observed at higher concentrations compared to the blood which also expressed co-stimulatory molecules (CD80 and CD86). The infiltration of novel cDC2 subsets was also observed. In summary, this thesis illustrates the kinetic and developmental profiles of human mononuclear phagocytes under steady-state and experimental inflammation

The Roles Ofmrna Stability And Secondary Structure In The Differential Expression Of The Escherichia Coliunc Genes

The genes of the Escherichia coli unc operon are differentially expressed according to the subunit requirements in the mature {dollar}\rm F\sb1F\sb0{dollar}-ATPase complex. The experiments described in this thesis were designed to elucidate how mRNA processing, degradation, and structure regulate the differential expression of the unc genes. Studies were focused on the uncBE region, near the 5{dollar}\sp\prime{dollar} end of the transcript, and uncDC region at the 3{dollar}\sp\prime{dollar} end of the transcript.;Northern blot analysis of uncC mRNA, the last gene of the operon, suggested that the unc transcription terminator protected the uncC message against exonucleolytic degradation, and that this stabilization was important in adequate synthesis of its gene product, the {dollar}\epsilon{dollar} subunit.;Northern blot and primer extension analysis of plasmid-encoded uncDC mRNA identified an RNase E-dependent endonucleolytic cleavage site 11 bases into the uncC coding region. This cleavage led to functional inactivation of the uncC mRNA and the upstream uncD mRNA, and consequently does not contribute to the differential relative expression of these genes.;A potential stem-loop structure 16 bases downstream of the uncC initiation codon, and 6 bases downstream of the aforementioned RNase E site, was subjected to site-directed mutagenesis to explore its significance in the RNase E-dependent cleavage, and in regulating the uncC expression. Results indicated that the structure was indispensable to the cleavage by RNase E, while the bases around the actual site were not so crucial. The expression studies uncovered a critical dependence of the stem-loop position in modulating the expression of uncC. The uncC expression was enhanced when the stem-loop was shifted downstream from the uncC ribosome binding site while moving it closer resulted in reduced expression of uncC. The results imply that the stem-loop provides steric hindrance to the binding of the ribosome and hence limits uncC expression.;Northern blot analysis of chromosomally-encoded unc mRNA indicated that its 5{dollar}\sp\prime{dollar} region also underwent RNase E-dependent processing. Northern blots of mRNA expressed from a plasmid carrying the uncBE genes from the 5{dollar}\sp\prime{dollar} region of the operon revealed that the uncB message was rapidly degraded by multiple internal cleavages, some dependent on functional RNase E. Primer extension analysis showed that the cleavages were made either in the uncB coding region or in the intercistronic region between uncB and uncE, the latter being the most 3{dollar}\sp\prime{dollar} cleavage. The rapid degradation of uncB message through cleavages at these sites provides a mechanism for segmental decay of unc mRNA to contribute to the differential expression of the unc genes

Colloidal inorganic particle-based edible oleogels and bigels

The basic building blocks which are recently being explored as structurants for oil gelation include crystalline particles (e.g. waxes), polymeric strands (e.g. cellulose derivatives) and crystalline fibers (e.g. 12 hydroxy stearic acid etc.).1-2 In the current paper, we report the use of colloidal inorganic particles, SiO2 (a food-grade additive, E 551) as new structurants to fabricate clear gels in sunflower oil.3 Oleogels with high gel strength (G\u27 \u3e 10,000 Pa), high resistance to flow (σY \u3e 100 Pa), temperature stability and a good thixotropic recovery (\u3e 70 %) were obtained at 10-15 %wt of SiO2. Cryo-SEM (along with energy-dispersive X-ray spectroscopy) revealed an interesting ‘chain-like’ arrangement of SiO2 aggregates which is responsible for creating a structural framework. The fact that the positive results were only seen with hydrophilic SiO2 (and not with functionalized hydrophobic SiO2) strongly suggests that hydrogen bonds among surface silanol groups (Si-OH) contributed to the network formation of colloidal particles. Moreover, water phase (structured using food hydrocolloids) was added to oleogel in different proportions to obtain stable ‘bigels\u27 with interesting microstructures (as seen under cryo-SEM and confocal microscope) and excellent rheological properties. Please click Additional Files below to see the full abstract

Edible oil structuring : an overview and recent updates

In recent years, research dealing with edible oil structuring has received considerable interest from scientific community working in the area of food formulation. Much of this interest is linked to the possibility of using structured oil in development of newer product formats with improved nutritional profile (trans fat-free, low in saturated fats and high in mono and/or poly unsaturated fatty acids). In addition to the obvious industrial need of finding the alternative formulation approach, the interesting properties of structured systems (particularly, oleogels) also makes them a fascinating subject for fundamental studies. In this paper, we attempt to give a comprehensive and concise overview of the field of oil structuring with special emphasis on the updates from recent years. Specifically, several categories of food-grade oleogelators and their potential food applications are summarized with typical examples along with a discussion on the general principles and unresolved challenges related to this emerging area

Formulation and evaluation of transdermal patch of Aceclofenac

The purpose of this research was to develop a matrix-type transdermal therapeutic system containing drug Aceclofenac with different ratios of hydrophilic (hydroxyl propyl cellulose) and hydrophobic (ethyl cellulose) polymeric systems by the solvent evaporation technique by using 15 % w/w of dibutyl phthalate to the polymer weight, incorporated as plasticizer. Different concentrations of oleic acid and isopropyl myristate were used to enhance the transdermal permeation of Aceclofenac. The physicochemical compatibility of the drug and the polymers studied by differential scanning calorimetry and infrared spectroscopy suggested absence of any incompatibility. Formulated transdermal films were physically evaluated with regard to thickness, weight variation, drug content, flatness, tensile strength, folding endurance, percentage of moisture content and water vapour transmission rate. All prepared formulations indicated good physical stability. In-vitro permeation studies of formulations were performed by using Franz diffusion cells. Formulation prepared with hydrophilic polymer containing permeation enhancer showed best in-vitro skin permeation through rat skin (Wistar albino rat) as compared to all other formulations. The results followed the release profile of Aceclofenac followed mixed zero-order and first-order kinetics in different formulation. However, the release profile of the optimized formulation F9 (r2 = 0.9935 for Higuchi) indicated that the permeation of the drug from the patches was governed by a diffusion mechanism. Formulation F9 showed highest flux among all the formulations and 1.369 fold enhancements in drug permeation. These results indicate that the formulation containing 15 % of oleic acid with 10 % Isopropyl myristate give better penetration of Aceclofenac through rat skin.Keywords: Aceclofenac, Transdermal Film, Permeation enhancer, In-vitro permeation study

Evaluation of synthesized cross linked polyvinyl alcohol as potential disintegrant

Purpose: The present study deals with evaluation of crosslinked poly vinyl alcohol (PVA) as a potential disintegrant. Methods: Crosslinking of PVA was carried out using glutaraldehyde as a crosslinker, in presence of acidic conditions. The crosslinking reaction was optimized for a) polymer: crosslinker ratio; b) temperature requirement and c) reaction duration. Certain physical parameters of the disintegrant (including sedimentation volume, hydration capacity, specific surface area and bulk and tap density) were determined and compared to the known disintegrants. Characterization was carried out using FT-IR, DSC, XRD, SEM and Photo microscopy studies. The developed excipient was also studied for acute toxicity in rats and found to be safe for oral use. Results: Disintegration property of formed product was found to give better results. As compared to known disintegrant (Ac-Di-Sol). The disintegration mechanism of developed disintegrant was postulated based on results obtained from various physical evaluations. Hausner's ratio & Carr's index value of 1.12 and 10.61 suggested excellent flowability. Wetting time and distintegration time of 21.90 +/- 0.1 and 26.20 +/- 0.2 seconds was obtained at the disintegrant level of 5 % w/w. Conclusions: By changing the condition parameters of well known crosslinking reaction of PVA, we obtained a crosslinked product which had excellent disintegration activity, good flow and optimal tableting properties

GRAY COLOR CONVERSION USING CLASSIFICATION METHOD

There are various methods of gray conversion of RGB color images. They are calculated by three functions, Grayscale function, the Desaturate function, and the value component of the HSV option of the Decompose function. By converting this method we found the gray color image but when trying the reverse it is not same as actual images. That is due to the function that produces same value for different color and when reversing there is conflict between choosing one of them. Here I want to introduce a function using Classification method that produces different values of gray color for a range of RGB color images so the nearly reverse is possible

On certain subclasses of analytic functions associated with the Carlson–Shaffer operator

The object of the present paper is to solve Fekete-Szego problem and determine the sharp upper bound to the second Hankel determinant for a certain class $R^{\lambda}(a,c,A,B)$ of analytic functions in the unit disk. We also investigate several majorization properties for functions belonging to a subclass $\widetilde {R}^{\lambda}(a,c, A,B)$ of $R^{\lambda}(a,c,A,B)$ and related function classes. Relevant connections of the main results obtained here with those given by earlier workers on the subject are pointed out