2,094 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.ΠΠΎΠ½ΠΈΠΌΠ°Π½ΠΈΠ΅ ΡΠΎΡΠ½ΡΡ
ΡΠΈΠ»ΠΎΠ³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΠΉ Ρ ΠΊΡΠ΅Π²Π΅ΡΠΎΠΊ Penaeidae Π²Π°ΠΆΠ½ΠΎ ΠΊΠ°ΠΊ Ρ ΠΎΠ±ΡΠ΅Π½Π°ΡΡΠ½ΠΎΠΉ ΡΠΎΡΠΊΠΈ Π·ΡΠ΅Π½ΠΈΡ, ΡΠ°ΠΊ ΠΈ Π΄Π»Ρ ΡΡΠ±Π½ΠΎΠΉ ΠΏΡΠΎΠΌΡΡΠ»Π΅Π½Π½ΠΎΡΡΠΈ. RAPD Π°Π½Π°Π»ΠΈΠ· Π±ΡΠ» ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ Π΄Π»Ρ ΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ ΡΠΈΠ»ΠΎΠ³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ²ΡΠ·Π΅ΠΉ 13 Π²ΠΈΠ΄ΠΎΠ² ΠΊΡΠ΅Π²Π΅ΡΠΎΠΊ Penaeidae. ΠΠ»Ρ ΠΌΠΎΡΡΠΎΠΌΠ΅ΡΡΠΈΡΠ΅ΡΠΊΠΈΡ
Π°Π½Π°Π»ΠΈΠ·ΠΎΠ² ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½Ρ 40 ΠΏΠ΅ΡΠ΅ΠΌΠ΅Π½Π½ΡΡ
ΠΈ ΠΎΠ±ΡΠΈΡ
Π΄Π»ΠΈΠ½ ΠΊΡΠ΅Π²Π΅ΡΠΎΠΊ Π΄Π»Ρ ΠΊΠ°ΠΆΠ΄ΠΎΠ³ΠΎ Π²ΠΈΠ΄Π° ΠΈ ΡΡΡΡΠ°Π½Π΅Π½ ΡΡΡΠ΅ΠΊΡ Π²Π°ΡΠΈΠ°Π±Π΅Π»ΡΠ½ΠΎΡΡΠΈ ΡΠ°Π·ΠΌΠ΅ΡΠ°. ΠΠΎΠΊΠ°Π·Π°ΡΠ΅Π»ΠΈ Π½ΠΎΡΠΌΠ°Π»ΠΈΠ·ΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΡΠ°Π·ΠΌΠ΅ΡΠ° ΠΎΠ±ΡΠ°Π±ΠΎΡΠ°Π½Ρ Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΠΊΠ»Π°ΡΡΠ΅ΡΠ½ΠΎΠ³ΠΎ Π°Π½Π°Π»ΠΈΠ·Π° UPGMA (Unweighted Pair-Group Method with Arithmetic Mean). ΠΡΠΈ RAPD Π°Π½Π°Π»ΠΈΠ·Π΅ ΡΠ΅ΡΡΡΠ΅ ΠΏΡΠ°ΠΉΠΌΠ΅ΡΠ° ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΈ Π΄ΠΎΡΡΠΎΠ²Π΅ΡΠ½ΡΠ΅ ΡΠ°Π·Π»ΠΈΡΠΈΡ ΠΌΠ΅ΠΆΠ΄Ρ Π²ΠΈΠ΄Π°ΠΌΠΈ. ΠΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΡ ΠΊΠΎΡΡΠ΅Π»ΡΡΠΈΠΈ ΠΌΠ΅ΠΆΠ΄Ρ ΠΏΠ°ΡΡΠ΅ΡΠ½Π°ΠΌΠΈ ΠΠΠ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½Ρ Π΄Π»Ρ ΠΏΠΎΡΡΡΠΎΠ΅Π½ΠΈΡ UPGMA Π΄Π΅Π½Π΄ΡΠΎΠ³ΡΠ°ΠΌΠΌ. Π€ΠΈΠ»ΠΎΠ³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΡΠ·ΠΈ, ΠΏΠΎΡΡΡΠΎΠ΅Π½Π½ΡΠ΅ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΌΠΎΡΡΠΎΠΌΠ΅ΡΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈ ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½ΡΡ
Π°Π½Π°Π»ΠΈΠ·ΠΎΠ², ΡΠΎΠ²ΠΏΠ°Π»ΠΈ, ΡΡΠΎ ΠΏΠΎΠ·Π²ΠΎΠ»ΠΈΠ»ΠΎ ΡΠ΄Π΅Π»Π°ΡΡ Π²ΡΠ²ΠΎΠ΄ ΠΎΠ± ΠΈΡ
Π΄ΠΎΡΡΠΎΠ²Π΅ΡΠ½ΠΎΡΡΠΈ
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 nonβtoxicity, biocompatibility and biodegradability. NβMethylenephenyl phosphonic chitosan (NMPPC) is synthesized from chitosan by reacting with phenyl phosphonic acid using formaldehyde. The NMPPC was characterized by FTIR, 31PβNMR, Xβray 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 Xβray 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 identiο¬ed 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 modiο¬es the innate immune response as shown by the marked decline in the pro-inο¬ammatory cytokines in a macrophage model of infection. These ο¬ndings suggest a novel mechanism,bywhichPknEsensesnitricoxidestress and prevents apoptosis by interfering with host signalling pathways
Estimation and compensation of IQ imbalance in SWIPT system
Although there are many articulations of SWIPT architecture implementations, the hardware impairment aspect involved in the SWIPT architecture system is not given much attention. This paper evaluates the performance of SWIPT PS Reciever architecture in the presence of IQ imbalance hardware impairment with 16-QAM transmitter and AWGN channel. The parameters SNR, BER is evaluated in the presence of amplitude, phase imbalance, and PS factor at the SWIPT receiver side. Further, the IQ imbalance is estimated and compensated using a blind compensation algorithm. The system achieved a maximum BER of 10β7 in the presence of amplitude and phase imbalance of 0.2 and 1.6 respectivel
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