943 resultados para medium of instruction


Relevância:

90.00% 90.00%

Publicador:

Resumo:

The thesis mainly focuses on material characterization in different environments: freely available samples taken in planar fonn, biological samples available in small quantities and buried objects.Free space method, finds many applications in the fields of industry, medicine and communication. As it is a non-contact method, it can be employed for monitoring the electrical properties of materials moving through a conveyor belt in real time. Also, measurement on such systems at high temperature is possible. NID theory can be applied to the characterization of thin films. Dielectric properties of thin films deposited on any dielectric substrate can be determined. ln chemical industry, the stages of a chemical reaction can be monitored online. Online monitoring will be more efficient as it saves time and avoids risk of sample collection.Dielectric contrast is one of the main factors, which decides the detectability of a system. lt could be noted that the two dielectric objects of same dielectric constant 3.2 (s, of plastic mine) placed in a medium of dielectric constant 2.56 (er of sand) could even be detected employing the time domain analysis of the reflected signal. This type of detection finds strategic importance as it provides solution to the problem of clearance of non-metallic mines. The demining of these mines using the conventional techniques had been proved futile. The studies on the detection of voids and leakage in pipes find many applications.The determined electrical properties of tissues can be used for numerical modeling of cells, microwave imaging, SAR test etc. All these techniques need the accurate determination of dielectric constant. ln the modem world, the use of cellular and other wireless communication systems is booming up. At the same time people are concemed about the hazardous effects of microwaves on living cells. The effect is usually studied on human phantom models. The construction of the models requires the knowledge of the dielectric parameters of the various body tissues. lt is in this context that the present study gains significance. The case study on biological samples shows that the properties of normal and infected body tissues are different. Even though the change in the dielectric properties of infected samples from that of normal one may not be a clear evidence of an ailment, it is an indication of some disorder.ln medical field, the free space method may be adapted for imaging the biological samples. This method can also be used in wireless technology. Evaluation of electrical properties and attenuation of obstacles in the path of RF waves can be done using free waves. An intelligent system for controlling the power output or frequency depending on the feed back values of the attenuation may be developed.The simulation employed in GPR can be extended for the exploration of the effects due to the factors such as the different proportion of water content in the soil, the level and roughness of the soil etc on the reflected signal. This may find applications in geological explorations. ln the detection of mines, a state-of-the art technique for scanning and imaging an active mine field can be developed using GPR. The probing antenna can be attached to a robotic arm capable of three degrees of rotation and the whole detecting system can be housed in a military vehicle. In industry, a system based on the GPR principle can be developed for monitoring liquid or gas through a pipe, as pipe with and without the sample gives different reflection responses. lt may also be implemented for the online monitoring of different stages of extraction and purification of crude petroleum in a plant.Since biological samples show fluctuation in the dielectric nature with time and other physiological conditions, more investigation in this direction should be done. The infected cells at various stages of advancement and the normal cells should be analysed. The results from these comparative studies can be utilized for the detection of the onset of such diseases. Studying the properties of infected tissues at different stages, the threshold of detectability of infected cells can be determined.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Optimum conditions and experimental details for the formation of v-Fe203 from goethite have been worked out. In another method, a cheap complexing medium of starch was employed for precipitating acicular ferrous oxalate, which on decomposition in nitrogen and subsequent oxidation yielded acicular y-Fe203. On the basis of thermal decomposition in dry and moist nitrogen, DTA, XRD, GC and thermodynamic arguments, the mechanism of decomposition was elucidated. New materials obtained by doping ~'-Fe203 with 1-16 atomic percent magnesium, cobalt, nickel and copper, were synthesised and characterized

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This paper studies six children with congenital aphasia and discusses various methods of instruction.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Architects and engineers depend on copyright law to protect their original works. Copyright protection is automatic once a tangible medium of expression in any form of an innovative material, conforming the Copyright Designs and Patents Act 1988, is created. In terms of architectural works, they are protected as literary works (design drawings and plans) and as artistic works (the building or model of the building). The case law on the concept of “originality” however discloses that it may be difficult for certain artistic works of architecture to achieve copyright protection. Although copyright law provides automatic protection to all original architectural plans, the limitation is that it only protects the expression of ideas but not the ideas themselves. The purpose of this research is to explore how effective the UK’s copyright law regime is for protecting the rights and interests of architects in their works. In addition, the United States system of copyright law will be analysed to determine whether it provides more effective protection for architects and engineers with regard to architectural works. The key objective in carrying out this comparison is to compare and contrast the extent to which the two systems protect the rights and interests of architects against copyright infringement. This comparative analysis concludes by considering the possibility of copyright law reform in the UK.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Copyright protects the rights and interests of authors on their original works of authorship such as literary, dramatic, musical, artistic, and certain other intellectual works including architectural works and designs. It is automatic once a tangible medium of expression in any form of an innovative material, which conforms the Copyright Designs and Patents Act 1988 (CDPA 1988), is created. This includes the building, the architectural plans and drawings. There is no official copyright registry, no requirements on any fees need to be paid and they can be published or unpublished materials. Copyrights owners have the rights to control the reproduction, display, publication, and even derivation of the design. However, there are limitations on the rights of the copyright owners concerning copyrights infringements. Infringement of copyright is an unauthorised violation of the exclusive rights of the copyright author. Architects and engineers depend on copyright law to protect their works and design. Copyrights are protected on the arrangements of spaces and elements as well as the overall form of the architectural design. However, it does not cover the design of functional elements and standard features. Although copyright law provides automatic protection to all original architectural plans, the limitation is that copyright only protects the expression of ideas but not the ideas themselves. It can be argued that architectural drawings and design, including models are recognised categories of artistic works which are protected under the copyright law. This research investigates to what extent copyrights protect the rights and interests of the designers on architectural works and design.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

A novel series of linear, high molecular weight polymers were synthesized by one-pot, superacid-catalyzed reaction of acenaphthenequinone (1) with aromatic hydrocarbons. The reactions were performed at room temperature in the Bronsted superacid CF3SO3H (trifluoromethanesulfonic acid, TFSA) and in a mixture of TFSA with methanesulfonic acid (MSA) and trifluoroacetic acid (TFA), which was used as both solvent and a medium for generation of electrophilic species from acenaphthenequinone. The polymer-forming reaction was found to be dependent greatly on the acidity of the reaction medium, as judged from the viscosity of the polymers obtained. Polycondensations of acenaphthenequinone with 4,4'-diphenoxybenzophenone (f), 1,3-bis(4-phenoxybenzoyl)benzene (g), 1,4-bis(4-phenoxybenzoyl)benzene (h), 1,10-bis(4-phenoxyphenyl)decane-1,10-dione (i), 2,6-diphenoxybenzonitrile), 2,6-diphenoxybenzoic acid (k), and 2-(4-biphenylyl)-6-phenylbenzoxazole (1) proceeded in a reaction medium of wide range of acidity, including pure TFSA (Hammett acidity function H-0 of pure TFSA is -14.1), whereas condensation of 1 with biphenyl, terphenyl, diphenyl ether, and 1,4-diphenoxybenzene needed a reaction medium of acidity H-0 less than -11.5. A possible reaction mechanism is suggested. The polymers obtained were found to be soluble in the common organic solvents, and flexible transparent films could be cast from the solutions. H-1 and C-13 NMR analyses of the polymers synthesized revealed their linear, highly regular structure. The polymers also possess high thermostability. Char yields for polymers 3a, 3c, 3d, and 3l in nitrogen were close to 80% at 1000 degrees C.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

In recognizing 11 official languages, the 1996 South African Constitution provides a context for the management of diversity with important implications for the redistribution of wealth and power. The development and implementation of the language-in-education policies which might be expected to flow from the Constitution, however, have been slow and ineffective. One of the casualties of government procrastination has been African language publishing. In the absence of well-resourced bilingual education, most learners continue to be taught through the medium of English as a second language. Teachers are reluctant to use more innovative pedagogies without the support of adequate African language materials and publishers are cautious about producing such materials. Nonetheless, activity in this sector offers many opportunities for African language speakers. This paper explores the challenges and constraints for African language publishing for children and argues that market forces and language policy need to work in mutually reinforcing ways. Further progress is necessarily dependent on the political will to implement language-in-education policies that promote additive bilingualism and, in the process, guarantee sales for risk-averse publishers.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The Twitter network has been labelled the most commonly used microblogging application around today. With about 500 million estimated registered users as of June, 2012, Twitter has become a credible medium of sentiment/opinion expression. It is also a notable medium for information dissemination; including breaking news on diverse issues since it was launched in 2007. Many organisations, individuals and even government bodies follow activities on the network in order to obtain knowledge on how their audience reacts to tweets that affect them. We can use postings on Twitter (known as tweets) to analyse patterns associated with events by detecting the dynamics of the tweets. A common way of labelling a tweet is by including a number of hashtags that describe its contents. Association Rule Mining can find the likelihood of co-occurrence of hashtags. In this paper, we propose the use of temporal Association Rule Mining to detect rule dynamics, and consequently dynamics of tweets. We coined our methodology Transaction-based Rule Change Mining (TRCM). A number of patterns are identifiable in these rule dynamics including, new rules, emerging rules, unexpected rules and ?dead' rules. Also the linkage between the different types of rule dynamics is investigated experimentally in this paper.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This study investigates the effects of a short-term pedagogic intervention on the development of L2 fluency among learners studying English for Academic purposes (EAP) at a university in the UK. It also examines the interaction between the development of fluency, and complexity and accuracy. Through a pre-test, post-test design, data were collected over a period of four weeks from learners performing monologic tasks. While the Control Group (CG) focused on developing general speaking and listening skills, the Experimental Group (EG) received awareness-raising activities and fluency strategy training in addition to general speaking and listening practice i.e following the syllabus. The data, coded in terms of a range of measures of fluency, accuracy and complexity, were subjected to repeated measures MANOVA, t-tests and correlations. The results indicate that after the intervention, while some fluency gains were achieved by the CG, the EG produced statistically more fluent language demonstrating a faster speech and articulation rate, longer runs and higher phonation time ratios. The significant correlations obtained between measures of accuracy and learners’ pauses in the CG suggest that pausing opportunities may have been linked to accuracy. The findings of the study have significant implications for L2 pedagogy, highlighting the effective impact of instruction on the development of fluency.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The clearance of apoptotic cells by phagocytes is a fundamental process during tissue remodeling and resolution of inflammation. In turn, the phagocytosis of apoptotic cells generates signals that suppress pro-inflammatory activation of macrophages. These events occur during the resolution phase of inflammation and therefore the malfunctioning of this process may lead to inflammation-related tissue damage. Here, we demonstrate that the calcium-binding protein S100A9, normally abundant in the cytoplasm of neutrophils and also released by apoptotic neutrophils, is involved in the suppression of macrophages after the uptake of apoptotic neutrophils. Both, spontaneous and induced production of inflammatory species (nitric oxide, hydrogen peroxide and TNF-alpha) as well as the phagocytic activity were inhibited when macrophages were in presence of apoptotic neutrophils, conditioned medium from neutrophil cultures or a peptide corresponding to the C-terminal region of S100A9 protein. On the other hand, macrophages kept in the conditioned medium of neutrophils that was previously depleted of S100A9 were shown to resume the activated status. Finally, we demonstrate that the calcium-binding property of S100A9 might play a role in the suppression process, since the stimulation of intracellular calcium release with ionomycin significantly reversed the effects of the uptake of apoptotic neutrophils in macrophages. In conclusion, we propose that S100A9 is a novel component of the regulatory mechanisms of inflammation, acting side-by-side with other suppressor factors generated upon ingestion of apoptotic cells. (C) 2009 Elsevier GmbH. All rights reserved.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Formaldehyde (FA) exposure induces upper airways irritation and respiratory abnormalities, but its mechanisms are not understood. Since mast cells are widely distributed in the airways, we hypothesized that FA might modify the airways reactivity by mechanism involving their activation. Tracheal rings of rats were incubated with Dulbecco`s modified medium culture containing FA (0.1 ppm) in 96-well plastic microplates in a humid atmosphere. After 30 min, 6 h, and 24-72 h, the rings were suspended in an organ bath and dose-response curve to methacholine (MCh) were determined. incubation with FA caused a transient tracheal hyperresponsiveness to MCh that was independent from tracheal epithelium integrity. Connective tissue mast cell depletion caused by compound 48/80 or mast cell activation by the allergic reaction, before exposure of tracheal rings to FA prevented the increased responsiveness to MCh. LTB(4) concentrations were increased in the culture medium of tracheas incubated with FA for 48 h, whereas the LTB(4)-receptor antagonist MK886 (1 mu M) added before FA exposure rendered the tracheal rings normoreactive to MCh. In addition, FA exposure did not cause hyperresponsiveness in tracheal segments incubated with L-arginine (1 mu M). We suggest that airway connective tissue mast cells constitute the target and may provide the increased LTB(4) generation as well as an elevated consumption of NO leading to tracheal hyperresponsiveness to MCh. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The sporulation stage of the aquatic fungus Blastocladiella emersonii culminates with the formation and release to the medium of a number of zoospores, which are motile cells responsible for the dispersal of the fungus. The presence in the sporulation solution of 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a potent and selective inhibitor of nitric oxide-sensitive guanylyl cyclases, completely prevented biogenesis of the zoospores. In addition, this compound was able to significantly reduce cGMP levels, which increase drastically during late sporulation, suggesting the existence of a nitric oxide-dependent mechanism for cGMP synthesis. Furthermore, increased levels of nitric oxide-derived products were detected during sporulation by fluorescence assays using DAF-2 DA, whose signal was drastically reduced in the presence of the nitric oxide synthase inhibitor N omega-Nitro-L-arginine methyl ester (L-NAME). These results were confirmed by quantitative chemiluminescent determination of the intracellular levels of nitric oxide-derived products. A putative nitric oxide synthase (NOS) activity was detected throughout sporulation, and this enzyme activity decreased significantly when L-NAME and 1-[2-(Trifluoromethyl)phenyl]imidazole (TRIM) were added to the assays. NOS assays carried out in the presence of EGTA showed decreased enzyme activity, suggesting the involvement of calcium ions in enzyme activation. Additionally, expressed sequence tags (ESTs) encoding putative guanylyl cyclases and a cGMP-phosphodiesterase were found in B. emersonii EST database (http://blasto.iq.usp.br), and the mRNA levels of the corresponding genes were observed to increase during sporulation. Altogether, data presented here revealed the presence and expression of guanylyl cyclase and cGMP phosphodiesterase genes in B. emersonii and provided evidence of a Ca(2+)-(center dot)NO-cGMP signaling pathway playing a role in zoospore biogenesis. (C) 2009 Elsevier Inc. All rights reserved.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Bone morphogenetic protein-7 (BMP-7) is a secreted multifunctional growth factor of the TGF-beta superfamily, which is predominantly known for its osteoinductive properties and emerging potential for treatment of kidney diseases. The mature 34-38 kDa disulfide-linked homodimer protein plays a key role in the differentiation of mesenchymal cells into bone and cartilage. In this study, the full-length sequence of hBMP-7 was amplified and, then, cloned, expressed, and purified from the conditioned medium of 293T cells stably transfected with a lentiviral vector. The mature protein dimer form was properly secreted and recognized by anti-BMP-7 antibodies, and the protein was shown to be glycosilated by treatment with exoglycosidase, followed by western blotting. Moreover, the activity of the purified protein was demonstrated both in vitro, by alkaline phosphatase activity in C2C12 cells, and in vivo by induction of ectopic bone formation in Balb/c Nude mice after 21 days, respectively. This recombinant protein platform may be very useful for expression of different human cytokines and other proteins for medical applications.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The present in vitro experiments were designed to evaluate the ability of bovine cumulus-oocyte-complexes (COCs)to produce steroids and also to evaluate the modulatory effects of added estradiol, progesterone and testosterone on the steroidogenic activity of COCs. Considerable estradiol accumulation was observed in the control maturation medium for in vitro maturation of bovine COCs during the 24h of maturation (P < 0.05). When testosterone was added to the medium at various concentrations, a slight estradiol accumulation occurred, which, however, was lower (P < 0.05) than that observed in the control medium. Slight estradiol accumulation was observed in maturation medium containing progesterone at concentrations of 2.5, 5.0 and 10.0 mug/ml, but these increases were less (P < 0.05) than those observed in the control medium. However, in the presence of 1.0 mug/ml progesterone, estradiol accumulation was equal to that of the control medium (P > 0.05). Progesterone accumulation (P < 0.05) was observed in the control medium for in vitro maturation of bovine COCs. When estradiol was added to the maturation medium, progesterone accumulation was observed, but was significant (P < 0.05) only when the medium was supplemented with the lesser concentrations of estradiol utilized in the experiment (1.0 mug/ml). The results demonstrated that (1) cumulus cells of bovine COCs are able to secrete estradiol and progesterone in culture systems for in vitro maturation, and this steroidogenesis is modulated by the steroids progesterone, testosterone and estradiol, and (2) the addition of estradiol to the in vitro maturation medium of bovine oocytes should be reviewed, since cumulus cells of COCs have been demonstrated to secrete estradiol in the maturation medium. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)