2,055 research outputs found
Developing Teaching Material for E-learning Environment
In the new economy, knowledge is a source for a competitive advantage. Economic and social developments are strongly related to the development of human capital, which is associated with education (ESCWA2005). The other hand, Information and communication Technologies (ICT) have changed the way people live and work, the ICT evolution increasingly supports innovative methods of learning. In this context, Rosenberg (2001) has observed that e-learning strategies are leading to changes in the way people learn. This paper focuses on the elements of effective design and development of quality materials for on-line learning. The elements of design are discussed in detail. Keywords: E-learning; Scenario, Feedback, Delivery, Context, Content Design and Writing, Materials Development
Phosphorous containing chitosan beads for controlled oral drug delivery
Phosphorous containing chitosan (PCTS) was synthesized by a
graft copolymerization technique in order to be used as controlled drug delivery
devices. To test this potential, PCTS beads were prepared by using
tripolyphosphate, at pH 4.0 and characterized by scanning electron
microscopy. The in vitro drug release behavior in various pH solutions was
studied using indomethacin (IM) as a model drug at two different concentrations
(0.3 and 0.6% w/w). The release percent of IM from PCTS beads was
found to be increased with the increasing of pH in the buffer solution. The
release rate of IM at pH 7.4 was higher than that at pH 1.4, due to the ionization
of phosphorous groups and the high solubility of IM in the alkaline
medium. These results indicated that PCTS beads have the potential to be
used as controlled drug delivery systems through oral administration by avoiding
the drug release in the highly acidic gastric fluid region of the stomach
Socio-economic Impact Assessment of Livelihood Security in Agriculture, Animal Husbandry and Aquaculture on the Tsunami-hit Lands of Andaman
Indian subcontinent is highly vulnerable to major natural disasters such as earthquakes, cyclones, floods, droughts, landslides and bushfires. Tsunami, which is a recent addition to this list, had occurred in the early morning of 26th December 2004, after a massive earthquake of 9.2 magnitude on the Richter scale in Andaman & Nicobar islands, resulting in the submergence of large area of farmland, and subsequent drying up of water bodies. It caused moisture stress for the standing crops, livestock and fisheries and affected the livelihood of the people to a large extent. In this context, the present study has been carried out to make the socio-economic impact assessment of livelihood security in agriculture, animal husbandry and aquaculture on the tsunami-hit lands of Andaman. Data have been collected from 150 sample respondents and the survey has been conducted for two periods, pre-tsunami and post-tsunami. The results have indicated that tsunami has ravaged the households, standing crops, farm inputs such as seed, feed and implements, livestock and poultry population, their sheds, fish ponds, etc., thereby affecting the basic livelihood security of the people in Andaman. The rehabilitation measures taken by the government and NGOs have improved their livelihoods by reviving agriculture considerably in the subsequent years and by creating employment opportunities in various farm and non-farm activities. The paper has suggested creating profitable livelihood security to vulnerable sections of the society in the existing socio-economic penury with holistic intervention of the community, government and NGOs.Agricultural and Food Policy,
Chemistry and applications of phosphorylated chitin and chitosan
Chitin and chitosan are natural based non-toxic,
biodegradable and biocompatible polymers and have been used in
biomedical areas in the form of sutures, wound healing materials and
artificial skin, and for the sustained release of drugs as well as in various
industrial applications. However, practical use of these polymers has
been mainly confined to the unmodified forms. Recently, there has been
a growing interest in chemical modification of chitin and chitosan to
improve their solubility and widen their applications. Among them,
phosphorylated chitin and chitosan have attracted considerable interest
because of their various advantages: anti-inflammatory property, ability
to form metal complexes, blood compatibility and formation of anionic
polyelectrolyte hydrogels. The purpose of this review is to take a closer
look of different synthetic methods of phosphorylated chitin and chitosan
and their potential applications in environmental, food, fuel cell, and
biomedical fields. Based on current research and existing products,
some new and futuristic approaches in this context area are discussed.R. Jayakumar acknowledges the Portuguese Foundation for Science and Technology for providing him a Post-Doc scholarship (SFRH/BPD/14670/2003). This work was partially supported by FCT Foundation for Science and Technology, through funds from the POCTI and/or FEDER program. This work was partially supported by the European Union funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758)
Conformation of phylogenetic relationship of penaeidae shrimp based on Morphometric and Molecular investigations
Understanding of accurate phylogenetic relationship among Penaeidae shrimp is important for academic and fisheries industry. The Morphometric and Randomly Amplified Polymorphic DNA (RAPD) analysis was used to make the phylogenetic relationsip among 13 Penaeidae shrimp. For morphometric analysis forty variables and total lengths of shrimp were measured for each species, and removed the effect of size variation. The size normalized values obtained was subjected to UPGMA (Unweighted Pair-Group Method with Arithmetic Mean) cluster analysis. For RAPD analysis, the four primers showed reliable differentiation between species, and used correlation coefficient between the DNA banding patterns of 13 Penaeidae species to construct UPGMA dendrogram. Phylogenetic relationship from morphometric and molecular analysis for Penaeidae species found to be congruent. We concluded that as the results from morphometry investigations concur with molecular one, phylogenetic relationship obtained for the studied Penaeidae are considered to be reliable.Понимание точных филогенетических отношений у креветок Penaeidae важно как с общенаучной точки зрения, так и для рыбной промышленности. RAPD анализ был использован для установления филогенетических связей 13 видов креветок Penaeidae. Для морфометрических анализов измерены 40 переменных и общих длин креветок для каждого вида и устранен эффект вариабельности размера. Показатели нормализованного размера обработаны с помощью кластерного анализа UPGMA (Unweighted Pair-Group Method with Arithmetic Mean). При RAPD анализе четыре праймера показали достоверные различия между видами. Коэффициенты корреляции между паттернами ДНК использованы для построения UPGMA дендрограмм. Филогенетические связи, построенные на основе морфометрических и молекулярных анализов, совпали, что позволило сделать вывод об их достоверности
Synthesis and characterization of N-methylenephenyl phosphonic chitosan
Chitosan is a natural based polymer obtained by alkaline deacetylation of chitin, exhibiting excellent properties such as non‐toxicity, biocompatibility and biodegradability. N‐Methylenephenyl phosphonic chitosan (NMPPC) is synthesized from chitosan by reacting with phenyl phosphonic acid using formaldehyde. The NMPPC was characterized by FTIR, 31P‐NMR, X‐ray diffraction, scanning electron microscopy, thermogravimeteric analysis and solubility studies. A significant decrease of molecular weight was observed in the NMPPC. The TGA studies suggested that NMPPC has less thermal stability than chitosan. The X‐ray diffraction analysis showed that NMPPC was amorphous in nature. The solubility property of the polymer was improved after the incorporation of a phenyl phosphonic grou
Protein kinase E of Mycobacterium tuberculosis has a role in the nitric oxide stress response and apoptosis in a human macrophage model of infection
Mycobacterium tuberculosis, an intracellular pathogen, inhibits macrophage apoptosis to support survival and replication inside the host cell. We provide evidence that the functional serine/threonine kinase, PknE, is important for survival of M. tuberculosis that enhances macrophage viability by inhibiting apoptosis.Apromoter of PknE identified in this study was shown to respond to nitric oxide stress. Deletion of pknE in virulent M. tuberculosis, H37Rv, resulted in a strain that has increased resistance to nitric oxide donors and increased sensitivity to reducing agents. The deletion mutant created by specialized transduction induced enhanced apoptosis while inhibiting necrosis. The pknE mutant also modifies the innate immune response as shown by the marked decline in the pro-inflammatory cytokines in a macrophage model of infection. These findings suggest a novel mechanism,bywhichPknEsensesnitricoxidestress and prevents apoptosis by interfering with host signalling pathways
Sea ranching of hatchery produced green tiger shrimp for the sustainable shrimp productivity
Green tiger shrimp Penaeus semisulcatus locally known as flower iral/Thaaliiral supporting commercial fishery in Gulf of Mannar and Palk Bay is widely exploited by the trawl net operated in mechanized boats. However, due to over fishing of brooders and juveiles over the years, these shrimp resources have depleted drastically. In an initiative to overcome the situation, the Mandapam Regional Centre of CMFRI has resorted to hatchery seed production of this species and ranching them, to replenish the natural stocks and to enhance the shrimp productivity
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