1,458 research outputs found

    Ultra wideband communication link

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    Ultra-wideband communication (UWB) has been a topic of extensive research in recent years especially for its short-range communication and indoor applications. The preliminary objective of the project was to develop a description and understanding of the basic components of the communication link at microwave frequencies in order to achieve the primary objective of establishing a communication setup at a bandwidth of 2.5 GHz for testing Ultra Wideband (UWB) antennas. This was achieved with the aid of commercially available optical system which was modified for the purpose. Beginning with the generation of baseband narrow pulses with energy spanning over a broad frequency range, through multiplexing of different parallel channels carrying these pulses into a single stream, to finally capturing the received signal to understand the effect of the communication link formed; all provided basis for identifying the issues and possible solutions to establishing a reliable communication link at UWB frequency

    Modeling Context-Adaptive Energy-Aware Security in Mobile Devices

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    As increasing functionality in mobile devices leads to rapid battery drain, energy management has gained increasing importance. However, differences in user’s usage contexts and patterns can be leveraged for saving energy. On the other hand, the increasing sensitivity of users’ data, coupled with the need to ensure security in an energy-aware manner, demands careful analyses of trade-offs between energy and security. The research described in this thesis addresses this challenge by 1)modeling the problem of context-adaptive energy-aware security as a combinatorial optimization problem (Context-Sec); 2) proving that the decision version of this problem is NP-Complete, via a reduction from a variant of the well-known Knapsack problem; 3) developing three different algorithms to solve a related offline version of Context-Sec; and 4) implementing tests and compares the performance of the above three algorithms with data-sets derived from real-world smart-phones on wireless networks. The first algorithm presented is a pseudo-polynomial dynamic programming (DP)algorithm that computes an allocation with optimal user benefit using recurrence of the relations; the second algorithm is a greedy heuristic for allocation of security levels based on user benefit per unit of power consumption for each level; and the third algorithm is a Fully Polynomial Time Approximation Scheme (FPTAS) which has a polynomial time execution complexity as opposed to the pseudo-polynomialDP based approach. To the best of the researcher’s knowledge, this is the first work focused on modeling, design, implementation and experimental performance

    Characterisation of Sirtuins in Parkinson's disease

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    PhD ThesisParkinson’s disease (PD) is a progressive, age-related, neurodegenerative disorder characterised by loss of dopaminergic neurones in substantia nigra pars compacta (SNpc) with the formation of α-synuclein rich Lewy bodies. The exact mechanism behind SNpc cell death is still unclear but at the molecular level, oxidative stress and mitochondrial dysfunction are thought to be involved. Sirtuins (SIRTs) are NAD+ dependent protein deacetylases and/or ADP-ribosyltransferases, that modulate apoptosis, gene expression, stress resistance and anti-oxidant defence mechanisms by targeting histone and non-histone proteins. Recent evidence has suggested that SIRT1 and SIRT3 are neuroprotective and SIRT2 promotes neuronal death. This study investigated the role of SIRTs in oxidative stress mediated cell death and PD. The toxicity of diquat and rotenone, which produce oxidative and mitochondrial stress, were measured in dopaminergic SH-SY5Y cells and the effect of over-expression and inhibition of deacetylase activity of SIRTs on cell viability after toxin treatment was determined. Over-expression of SIRT1, SIRT2 and SIRT3 protected the cells from toxin induced cell death. The protection conferred by SIRT1 was partially independent of its deacetylase activity, which was mediated through the repression of NF-кB expression. On the other hand, protection exerted by SIRT2 and SIRT3 was entirely dependent on their enzymatic activity and was induced through higher expression of SOD2. SIRTs also reduced the formation of α-synuclein aggregates although only SIRT3 was co-localised with α-synuclein. In post-mortem brain tissue obtained from patients with Parkinson’s disease, Parkinson’s disease with dementia, dementia with Lewy bodies and Alzheimer’s disease, the activity of SIRT1 was observed to be down-regulated whereas, SIRT2 showed increased activity compared to controls. The increased activity of SIRT2 is possibly a compensatory effect to combat oxidative stress. SIRT3 was observed to be active in microglial cells in disease, implying an activation of anti-oxidant defence mechanism towards neuronal stress in neurodegenerative disorders. In conclusion, the main results of this thesis suggest that SIRTs rescue cells from oxidative stress and reduce the formation of α-synuclein aggregates. The mechanism through which they confer the protection is through enhancement of anti-oxidant pathways and repression of inflammatory responses.funded by the Biomedical Research Unit and was also awarded a Newcastle University Overseas Research Scholarship

    Isolation, screening and selection of xylanase producing thermophilic fungi from Raipur

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    In the present study, isolation, screening and selection of xylanase producing thermophilic fungi from soil of Raipur was studied. A total of 55 fungal isolates were isolated and screened  for  xylanase  activity  by  standard  plate assay method and activity of xylanase was determined by estimating the amount of released  reducing  sugar  xylose  in  culture  filtrates. Based on screening methods, 18 isolates with higher xylanase activity were selected for studying effect of temperature i.e.  25,  35,  45,  50,  55,  60,  65oC on their mycelial biomass production and  for studying percent  coagulation  of protein  at 50oC  at  different  intervals  of  time. Five isolates namely Chrysosporium tropicum NFCCI 2531, Malbranchea  cinnamomea MTCC  11894,  Aspergillus  fumigatus NFCCI  2532, Aspergillus  terrus NFCCI  2533  and  Emericella  nidulans NFCCI2538  showed maximum biomass production  at 45oC (0.19 to 0.32g/100ml/10days)  and minimum protein coagulation at 50oC (14% to 25%). Keywords: Thermophilic fungi, screening, xylanase, temperature biomass, protein coagulation, reducing sugar, xylose. ÂÂ

    Thyroid Hormones and Hematological Indices Levels in Thyroid Disorder

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    Background: Thyroid hormones play an important role in hematopoiesis. Disorders of these hormones cause an effect on hematological indices levels. Present study is designed to evaluate the effect of thyroid disorders on different hematological indices levels.Material and Method: A total of 166 including 54 hypothyroid, 30 hyperthyroid and 82 control subjects were evaluated. A comparison was done on different parameters.Result: A statistical difference was observed for MCV and MCH but other parameters did not show any statistically significant difference.Conclusion: All the patients with thyroid disorders should be periodically evaluated for hematological changes

    A Quantitative Study on Information-Seeking Behaviour about Wellness and Nutrition in the Digital Age

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    The use of E-resources has become a way of life. Seeking nutrition information has been seen to be directly related to wellness. The objective of the study was to assess and ascertain the use of the Internet and digital information seeking among students and professionals. The study also aimed to assess the preference of allopathic therapy over home remedies among the respondents. 275 respondents- 155 students and 120 professionals residing in Chandigarh Tricity were assessed. A self-designed questionnaire with five items on a five-point scale was used to procure information. The results showed that respondents agreed that they searched information digitally. Following healthy tips showed a neutral to agreeing on response whereas whether libraries were visited received a neutral response. In comparison, it was seen that there was a statistical difference (p\u3c0.01**) among seeking digital information among students and professionals. Use of the library for information seeking was higher among students (3.510± 1.32) than professionals (2.600± 1.19), p\u3c0.01**. It can be inferred that respondents relied more on digital information rather than the use of libraries. The overall neutral response was seen for preference of allopathy over home remedies, but, professionals were seen to be more inclined towards home remedies (p\u3c0.01**). A significant correlation was seen between the preference of medication and E-resources (p\u3c0.01**). It can be concluded that students utilized both E-resources and libraries more than the professionals. Education plays an important role in choosing the type of medication. Thus, E-resources have gained more momentum as an information-seeking tool

    An Implementation Tour to AngularJS

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    Angular Java Script Framework extends the HTML attribute.It easily binds the data to HTML with expression only for adding the Script tag in HTML coding. Angular Java Script Framework is mostly used for making the dynamic web page as well as also increase the web performance. The paper totally revolves around how to create client side applications
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