814 resultados para Databases and Information Systems
Resumo:
The formation and the isolation of fluoroboron salts, (D2BF2+)(PF6-), (DD'BF2+)(PF6-) and (D3BF2+)(PF6-)2, have been carried out. 1,8-Diazabicyclo [5,4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4,3,O]non-5-ene (DBN), extremely strong organic bases, were introduced into the fluoroboron cation systems and induced a complicated redistribution reaction in the D/BF3/BC13 systems. The result was the formation of all BFnCI4-n-, D.BFnCI3-n and fluoroboron cation species which were detected by 19p and 11B NMR spectrometry. The displacement reaction of CI- from these D.BFnCI3-n (n = 1 and 2) species by the second entering ligand is much faster than in other nitrogen donor containing systems which have been previously studied. Tetramethylguanidine, oxazolines and thiazolines can also produce similar reactions in D/BF3/BCI3 systems, but no significant BFnC4-n- species were observed. As well as influences of their basicity and their steric hindrance, N=C-R(X) (X = N, 0 or S) and N=C( X)2 (X = N or S) structures of ligands have significant effects on the fonnationof fluoroboron cations and the related NMR parameters. D3BF2+ and some D2BF2+ show the expected inertness, but (DBU)2BF2+ shows an interestingly high reactivity. (D2BF2+)(X-) formed from weak organic bases such as pyridine can react with stronger organic bases and form DD'BF2+ and D'2BF2+ in acetone or nitromethane. Fast atom bombardment mass spectrometry is doubly meaningful to this work. Firstly, FABMS can be directly applied to the complicated fluoroboron cation containing solution systems as an excellent complementary technique to multinuclear NMR. Secondly, the gas-phase ion substitution reaction of (D2BF2+)(PF6-) with the strong organic bases is successfully observed in a FABMS ion source when the B-N bond is not too strong in these cations.
Resumo:
Individuals who have sustained a traumatic brain injury (TBI) often complain of t roubl e sleeping and daytime fatigue but little is known about the neurophysiological underpinnings of the s e sleep difficulties. The fragile sleep of thos e with a TBI was predicted to be characterized by impairments in gating, hyperarousal and a breakdown in sleep homeostatic mechanisms. To test these hypotheses, 20 individuals with a TBI (18- 64 years old, 10 men) and 20 age-matched controls (18-61 years old, 9 men) took part in a comprehensive investigation of their sleep. While TBI participants were not recruited based on sleep complaint, the fmal sample was comprised of individuals with a variety of sleep complaints, across a range of injury severities. Rigorous screening procedures were used to reduce potential confounds (e.g., medication). Sleep and waking data were recorded with a 20-channel montage on three consecutive nights. Results showed dysregulation in sleep/wake mechanisms. The sleep of individuals with a TBI was less efficient than that of controls, as measured by sleep architecture variables. There was a clear breakdown in both spontaneous and evoked K-complexes in those with a TBI. Greater injury severities were associated with reductions in spindle density, though sleep spindles in slow wave sleep were longer for individuals with TBI than controls. Quantitative EEG revealed an impairment in sleep homeostatic mechanisms during sleep in the TBI group. As well, results showed the presence of hyper arousal based on quantitative EEG during sleep. In wakefulness, quantitative EEG showed a clear dissociation in arousal level between TBls with complaints of insomnia and TBls with daytime fatigue. In addition, ERPs indicated that the experience of hyper arousal in persons with a TBI was supported by neural evidence, particularly in wakefulness and Stage 2 sleep, and especially for those with insomnia symptoms. ERPs during sleep suggested that individuals with a TBI experienced impairments in information processing and sensory gating. Whereas neuropsychological testing and subjective data confirmed predicted deficits in the waking function of those with a TBI, particularly for those with more severe injuries, there were few group differences on laboratory computer-based tasks. Finally, the use of correlation analyses confirmed distinct sleep-wake relationships for each group. In sum, the mechanisms contributing to sleep disruption in TBI are particular to this condition, and unique neurobiological mechanisms predict the experience of insomnia versus daytime fatigue following a TBI. An understanding of how sleep becomes disrupted after a TBI is important to directing future research and neurorehabilitation.
Resumo:
Rats produce ultrasonic vocalizations that can be categorized into two types of ultrasonic calls based on their sonographic structure. One group contains 22-kHz ultrasonic vocalization (USVs), characterized by relatively constant (flat) frequency with peak frequency ranging from 19 to 28-kHz, and a call duration ranging between 100 – 3000 ms. These vocalization can be induced by cholinomimetic agents injected into the ascending mesolimbic cholinergic system that terminates in the anterior hypothalamic-preoptic area (AH-MPO) and lateral septum (LS). The other group of USVs contains 50-kHz USVs, characterized by high peak frequency, ranging from 39 to 90-kHz, short duration ranging from 10-90 ms, and varying frequency and complex sonographic morphology. These vocalizations can be induced by dopaminergic agents injected into the nucleus accumbens, the target area for the mesolimbic dopaminergic system. 22-kHz USVs are emitted in situations that are highly aversive, such as proximity of a predator or anticipation of a foot shock, while 50 kHz USVs are emitted in rewarding and appetitive situations, such as juvenile play behaviour or anticipation of rewarding electrical brain stimulation. The activities of these two mesolimbic systems were postulated to be antagonistic to each other. The current thesis is focused on the interaction of these systems indexed by emission of relevant USVs. It was hypothesized that emission of 22 kHz USVs will be antagonized by prior activation of the dopaminergic system while emission of 50 kHz will be antagonized by prior activation of the cholinergic system. It was found that injection of apomorphine into the shell of the nucleus accumbens significantly decreased the number of carbachol-induced 22 kHz USVs from both AH-MPO and LS. Injection of carbachol into the LS significantly decreased the number of apomorphine-induced 50 kHz USVs from the shell of the nucleus accumbens. The results of the study supported the main hypotheses that the mesolimbic dopaminergic and cholinergic systems function in antagonism to each other.
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A conceptual analysis of educational leadership explored the influence of managed and living systems on 21st century leadership discourse. Drawing on a detailed understanding of managed and living systems theory compiled from the work of Capra (2002), Morgan (1997), Mitchell and Sackney (2009), and Wheatley (2007), this study draws attention to the managed systems systemic concepts of efficiency, control, and standardization, and the living systems concepts of collaboration, shared meaning, change, and interconnection as markers of systems theory that find resonance within leadership literature. Using these systemic concepts as a framework, this study provides important insights into the espousal of managed and living systems concepts within the leadership discourse.
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FPS is a more general form of synchronization. Hyperchaotic systems possessing more than one positive Lypaunov exponent exhibit highly complex behaviour and are more suitable for some applications like secure communications. In this thesis we report studies of FPS and MFPS of a few chaotic and hyperchaotic systems. When all the parameters of the system are known we show that active nonlinear control method can be efectively used to obtain FPS. Adaptive nonlinear control and OPCL control method are employed for obtaining FPS and MFPS when some or all parameters of the system are uncertain. A secure communication scheme based on MFPS is also proposed in theory. All our theoretical calculations are verified by numerical simulations.
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Remote Data acquisition and analysing systems developed for fisheries and related environmental studies have been reported. It consists of three units. The first one namely multichannel remote data acquisition system is installed at the remote place powered by a rechargeable battery. It acquires and stores the 16 channel environmental data on a battery backed up RAM. The second unit called the Field data analyser is used for insitue display and analysis of the data stored in the backed up RAM. The third unit namely Laboratory data analyser is an IBM compatible PC based unit for detailed analysis and interpretation of the data after bringing the RAM unit to the laboratory. The data collected using the system has been analysed and presented in the form of a graph. The system timer operated at negligibly low current, switches on the power to the entire remote operated system at prefixed time interval of 2 hours.Data storage at remote site on low power battery backedupRAM and retrieval and analysis of data using PC are the special i ty of the system. The remote operated system takes about 7 seconds including the 5 second stabilization time to acquire and store data and is very ideal for remote operation on rechargeable bat tery. The system can store 16 channel data scanned at 2 hour interval for 10 days on 2K backed up RAM with memory expansion facility for 8K RAM.
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Present thesis has discussed the design and synthesis of polymers suitable for nonlinear optics. Most of the molecules that were studied have shown good nonlinear optical activity. The second order nonlinear optical activity of the polymers was measured experimentally by Kurtz and Perry powder technique. The thesis comprises of eight chapters.The theory of NLO phenomenon and a review about the various nonlinear optical polymers has been discussed in chapter 1. The review has provided a survey of NLO active polymeric materials with a general introduction, which included the principles and the origin of nonlinear optics, and has given emphasis to polymeric materials for nonlinear optics, including guest-host systems, side chain polymers, main chain polymers, crosslinked polymers, chiral polymers etc.Chapter 2 has discussed the stability of the metal incorporated tetrapyrrole molecules, porphyrin, chlorin and bacteriochlorin.Chapter 3 has provided the NLO properties of certain organic molecules by computational tools. The chapter is divided into four parts. The first part has described the nonlinear optical properties of chromophore (D-n-A) and bichromophore (D-n-A-A-n-D) systems, which were separated by methylene spacer, by making use of DPT and semiempirical calculations.Chapter 4: A series of polyurethanes was prepared from cardanol, a renewable resource and a waste of the cashew industry by previously designed bifunctional and multifunctional polymers using quantum theoretical approach.Chapter 5: A series of chiral polyurethanes with main chain bis azo diol groups in the polymer backbone was designed and NLO activity was predicted by ZlNDO/ CV methods.In Chapter 7, polyurethanes were first designed by computational methods and the NLO properties were predicted by correction vector method. The designed bifunctional and multifunctional polyurethanes were synthesized by varying the chiral-achiral diol compositions
Resumo:
Production Planning and Control (PPC) systems have grown and changed because of the developments in planning tools and models as well as the use of computers and information systems in this area. Though so much is available in research journals, practice of PPC is lagging behind and does not use much from published research. The practices of PPC in SMEs lag behind because of many reasons, which need to be explored This research work deals with the effect of identified variables such as forecasting, planning and control methods adopted, demographics of the key person, standardization practices followed, effect of training, learning and IT usage on firm performance. A model and framework has been developed based on literature. Empirical testing of the model has been done after collecting data using a questionnaire schedule administered among the selected respondents from Small and Medium Enterprises (SMEs) in India. Final data included 382 responses. Hypotheses linking SME performance with the use of forecasting, planning and controlling were formed and tested. Exploratory factor analysis was used for data reduction and for identifying the factor structure. High and low performing firms were classified using a Logistic Regression model. A confirmatory factor analysis was used to study the structural relationship between firm performance and dependent variables.
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The paper discusses the use of online information resources for organising knowledge in library and information centres in Cochin University of Science and Technology (CUSAT). The paper discusses the status and extent of automation in CUSAT library. The use of different online resources and the purposes for which these resources are being used, is explained in detail. Structured interview method was applied for collecting data. It was observed that 67 per cent users consult online resources for assisting knowledge organisation. Library of Congress catalogue is the widely used (100 per cent) online resource followed by OPAC of CUSAT and catalogue of British Library. The main purposes for using these resources are class number building and subject indexing
Design and study of self-assembled functional organic and hybrid systems for biological applications
Resumo:
The focus of self-assembly as a strategy for the synthesis has been confined largely to molecules, because of the importance of manipulating the structure of matter at the molecular scale. We have investigated the influence of temperature and pH, in addition to the concentration of the capping agent used for the formation of the nano-bio conjugates. For example, the formation of the narrower size distribution of the nanoparticles was observed with the increase in the concentration of the protein, which supports the fact that γ-globulin acts both as a controller of nucleation as well as stabiliser. As analyzed through various photophysical, biophysical and microscopic techniques such as TEM, AFM, C-AFM, SEM, DLS, OPM, CD and FTIR, we observed that the initial photoactivation of γ-globulin at pH 12 for 3 h resulted in small protein fibres of ca. Further irradiation for 24 h, led to the formation of selfassembled long fibres of the protein of ca. 5-6 nm and observation of surface plasmon resonance band at around 520 nm with the concomitant quenching of luminescence intensity at 680 nm. The observation of light triggered self-assembly of the protein and its effect on controlling the fate of the anchored nanoparticles can be compared with the naturally occurring process such as photomorphogenesis.Furthermore,our approach offers a way to understand the role played by the self-assembly of the protein in ordering and knock out of the metal nanoparticles and also in the design of nano-biohybrid materials for medicinal and optoelectronic applications. Investigation of the potential applications of NIR absorbing and water soluble squaraine dyes 1-3 for protein labeling and anti-amyloid agents forms the subject matter of the third chapter of the thesis. The study of their interactions with various proteins revealed that 1-3 showed unique interactions towards serum albumins as well as lysozyme. 69%, 71% and 49% in the absorption spectra as well as significant quenching in the fluorescence intensity of the dyes 1-3, respectively. Half-reciprocal analysis of the absorption data and isothermal titration calorimetric (ITC) analysis of the titration experiments gave a 1:1 stoichiometry for the complexes formed between the lysozyme and squaraine dyes with association constants (Kass) in the range 104-105 M-1. We have determined the changes in the free energy (ΔG) for the complex formation and the values are found to be -30.78, -32.31 and -28.58 kJmol-1, respectively for the dyes 1, 2 and 3. Furthermore, we have observed a strong induced CD (ICD) signal corresponding to the squaraine chromophore in the case of the halogenated squaraine dyes 2 and 3 at 636 and 637 nm confirming the complex formation in these cases. To understand the nature of interaction of the squaraine dyes 1-3 with lysozyme, we have investigated the interaction of dyes 1-3 with different amino acids. These results indicated that the dyes 1-3 showed significant interactions with cysteine and glutamic acid which are present in the side chains of lysozyme. In addition the temperature dependent studies have revealed that the interaction of the dye and the lysozyme are irreversible. Furthermore, we have investigated the interactions of these NIR dyes 1-3 with β- amyloid fibres derived from lysozyme to evaluate their potential as inhibitors of this biologically important protein aggregation. These β-amyloid fibrils were insoluble protein aggregates that have been associated with a range of neurodegenerative diseases, including Huntington, Alzheimer’s, Parkinson’s, and Creutzfeldt-Jakob diseases. We have synthesized amyloid fibres from lysozyme through its incubation in acidic solution below pH 4 and by allowing to form amyloid fibres at elevated temperature. To quantify the binding affinities of the squaraine dyes 1-3 with β-amyloids, we have carried out the isothermal titration calorimetric (ITC) measurements. The association constants were determined and are found to be 1.2 × 105, 3.6× 105 and 3.2 × 105 M-1 for the dyes, 1-3, respectively. To gain more insights into the amyloid inhibiting nature of the squaraine dyes under investigations, we have carried out thioflavin assay, CD, isothermal titration calorimetry and microscopic analysis. The addition of the dyes 1-3 (5μM) led to the complete quenching in the apparent thioflavin fluorescence, thereby indicating the destabilization of β-amyloid fibres in the presence of the squaraine dyes. Further, the inhibition of the amyloid fibres by the squaraine dyes 1-3, has been evidenced though the DLS, TEM AFM and SAED, wherein we observed the complete destabilization of the amyloid fibre and transformation of the fibre into spherical particles of ca. These results demonstrate the fact that the squaraine dyes 1-3 can act as protein labeling agents as well as the inhibitors of the protein amyloidogenesis. The last chapter of the thesis describes the synthesis and investigation of selfassembly as well as bio-imaging aspects of a few novel tetraphenylethene conjugates 4-6.Expectedly, these conjugates showed significant solvatochromism and exhibited a hypsochromic shift (negative solvatochromism) as the solvent polarity increased, and these observations were justified though theoretical studies employing the B3LYP/6-31g method. We have investigated the self-assembly properties of these D-A conjugates though variation in the percentage of water in acetonitrile solution due to the formation of nanoaggregates. Further the contour map of the observed fluorescence intensity as a function of the fluorescence excitation and emission wavelength confirmed the formation of J-type aggregates in these cases. To have a better understanding of the type of self-assemblies formed from the TPE conjugates 4-6, we have carried out the morphological analysis through various microscopic techniques such as DLS, SEM and TEM. 70%, we observed rod shape architectures having ~ 780 nm in diameter and ~ 12 μM in length as evidenced through TEM and SEM analysis. We have made similar observations with the dodecyl conjugate 5 at ca. 70% and 50% water/acetonitrile mixtures, the aggregates formed from 4 and 5 were found to be highly crystalline and such structures were transformed to amorphous nature as the water fraction was increased to 99%. To evaluate the potential of the conjugate as bio-imaging agents, we have carried out their in vitro cytotoxicity and cellular uptake studies though MTT assay, flow cytometric and confocal laser scanning microscopic techniques. Thus nanoparticle of these conjugates which exhibited efficient emission, large stoke shift, good stability, biocompatibility and excellent cellular imaging properties can have potential applications for tracking cells as well as in cell-based therapies. In summary we have synthesized novel functional organic chromophores and have studied systematic investigation of self-assembly of these synthetic and biological building blocks under a variety of conditions. The investigation of interaction of water soluble NIR squaraine dyes with lysozyme indicates that these dyes can act as the protein labeling agents and the efficiency of inhibition of β-amyloid indicate, thereby their potential as anti-amyloid agents.
Resumo:
The nonforgetting restarting automaton is a generalization of the restarting automaton that, when executing a restart operation, changes its internal state based on the current state and the actual contents of its read/write window instead of resetting it to the initial state. Another generalization of the restarting automaton is the cooperating distributed system (CD-system) of restarting automata. Here a finite system of restarting automata works together in analyzing a given sentence, where they interact based on a given mode of operation. As it turned out, CD-systems of restarting automata of some type X working in mode =1 are just as expressive as nonforgetting restarting automata of the same type X. Further, various types of determinism have been introduced for CD-systems of restarting automata called strict determinism, global determinism, and local determinism, and it has been shown that globally deterministic CD-systems working in mode =1 correspond to deterministic nonforgetting restarting automata. Here we derive some lower bound results for some types of nonforgetting restarting automata and for some types of CD-systems of restarting automata. In this way we establish separations between the corresponding language classes, thus providing detailed technical proofs for some of the separation results announced in the literature.
Resumo:
The main objective of this PhD research study is to provide a perspective on the urban growth management and sustainable development in Palestine, and more specifically in Hebron district as a case study. Hebron is located 36 km south of Jerusalem, with an overall population size of around 600,000 people living in a total area around1246km2. Hebron is the biggest Palestinian district that has 16 municipalities and 154 localities. The research discusses and analyzes the urban planning system, economical and environmental policies and the solution required to manage and integrate the development elements to develop a sustainable development plan for Hebron. The research provides answers for fundamental questions such as what kind and definition of sustainable development are applicable to the Palestinian case?. What are the sustainability problems there and how the Israeli occupation and unstable political condition affect the sustainable development in Palestine? What are the urban growth management and sustainability policies and actions required from government, public and privets sector in Palestine? The fast urban growth in Palestine is facing many problems and challenges due to the increase in the population size and the resulting impact of this increase including, but not limited to, the demand of new houses, need for more infrastructure services, demands on new industrial, commercial, educational and health projects, which in turn reduces the area of agricultural lands and threatens the natural resources and environment. There are also other associated sustainability problems like the absence of effective plans or regulations that control urban expansion, the absence of sufficient sustainable development plans at the national levels for the district, new job requirements, Israeli restrictions and occupation for more than 60 years, existence of construction factories near residential areas, poor public awareness and poor governmental funds for service projects and development plans. The study consists of nine chapters. Chapter One includes an introduction, study objectives, problems and justifications, while Chapter Two has a theoretical background on sustainability topic and definitions of sustainability. The Palestinian urban planning laws and local government systems are discussed in Chapter Three and the methodology of research is detailed in Chapter Four. As for Chapter Five, it provides a general background on Hebron District including demographical and economical profiles, along with recommendations related to sustainable development for each profile Chapter Six addresses the urban environment, sustainability priorities and policies required. Chapter Seven discusses and analyzes infrastructure services including transportation, water and wastewater. As for Chapter Eight, it addresses the land use, housing and urban expansion beside the cultural heritage, natural heritage with relevant sustainable development polices and recommendations. Finally, Chapter Nine includes a conclusion and comprehensive recommendations integrating all of urban and sustainability event in one map. Hebron has a deep history including a rich cultural heritage aged by thousands of years, with 47% of Hebron district population under 14 years old. Being the biggest Palestinian district, Hebron has thousands of industrial and economical organizations beside a large agricultural sector at Palestine level. This gives Hebron a potential to play major roles in developing a national sustainability plan, as the current urban planning system in Palestine needs urgent reform and development to fulfill the sustainability requirement. The municipalities and ministers should find permanent financial aid for urban planning and development studies so as to face future challenges. The Palestinian government can benefit from available local human resources in development projects; hence Palestinian people have sufficient qualifications in most sectors. The Palestinian people also can invest in the privet sector in Palestine in case businessmen have been encouraged and clear investment laws and plans have been developed. The study provides recommendations associated to the sustainable development in Palestine in general and Hebron, as a case study, in specific. Recommendations include increasing the privet sector as well as the public involvement in urban growth management, and stopping unplanned urban expansion, subjecting granting building permits of new projects to the no-harm environmental impact assessment, increasing the coordination and cooperation between localities and central bodies, protection and renovation of old cites and green areas, increasing the quality and quantity of infrastructure services, establishing district urban planning department to coordinate and organize urban planning and sustainable development activities. Also, among recommendations come dividing Hebron into three planning and administrative areas (north, central and south), and dividing the sustainable development and implementation period (2010 to 2025) into three main phases. Finally, the study strongly recommends benefiting from the same urban development plans in similar districts at national and international levels, also to use new technologies and information systems in urban planning process.
Resumo:
The summary from Goodson’s group on their recent work on heat transfer issues in the microelectronics and data storage industries illustrate the critical role of heat transfer for some areas of information technology. In this article, we build on their work and discuss some directions worthy of further research.