A Twitter-Based Weighted Reputation system

AbstractTrust between buyers and sellers plays an essential role in online shopping. Therefore, reputation systems are, typically, integrated with online shopping systems to form trust decisions between sellers and buyers. Online Social Networks (OSNs), such as Twitter, LinkedIn, MySpace and Facebook connect people from all over the world in a virtual community. OSNs can provide information about the relationships between people. This information can be used to improve the reliability of reputation systems. With twitter having over than 200 million users and due to its microblogging nature, we choose twitter as a basis for a reputation system

Chelation activity of N'1,N'6-bis((E)-3,4-dihydroxybenzylidene)adipohydrazide towards some transition metal ions

New chelating agent, N'1,N'6-bis((E)-3,4-dihydroxybenzylidene)adipohydrazide (DBAH) was synthesized and its crystal structure was analyzed by X-ray single crystal diffractometer. Homometallic complexes of Zr(IV), Co(II), Ni(II), Cu(II), Cd(II) and heterometallic complex of Co(II)/Zn(II) or Co(II)/Zn(II)/Cd(II) have been synthesized and characterized by spectroscopic and physicochemical methods. The data confirms the formation of bi- and tetra-metallic complexes. The ligand behaves as a neutral tetradentate in the Co(II) and Ni(II) complexes; tetranegative tetradentate in Zr(IV) and Cd(II) complexes and binegative octadentate in [Co2Zn2(DBAH)Cl6] and [Co2ZnCd(DBAH-4H)(H2O)4Cl4].H2O. A tetrahedral structure was proposed for the Ni(II), Zr(IV) and Co(II)/Zn(II) complexes; square-planar for the Cu(II) complex and octahedral geometry for the Co(II) complex. The ESR spectrum confirms the proposed structure of the Cu(II) complex. The thermal analyses confirm the stability of these complexes in the range 275-418 °C. The molecular modeling of [Co2Zn2(DBAH)Cl8] was drawn and its parameters were calculated

Synthetic and kinetic studies of some transition metal complexes of macrocyclic ligands

This thesis is divided into two sections. The first section deals with kinetic studies and the second section with synthetic and stereochemical investigations. The kinetics and mechanism of the acid-catalysed decarboxylation of a number of complexes of the general type cis-[CoN4CO3]+ (where N4 = 5,12-dimethyl-1,4,8,11-tetra-azacyclotetradeca-4,11-diene, C-meso-5,12-dimethyl-1,4,8,11-tetra-azacyclotetradecane, 1,4,7,10-tetra-azacyclododecane and 3,6-dimethyl-1,8-diamino-3,6-diazaoctane). The acid-catalysed decarboxylation of these complexes has been studied over a range of perchloric acid of nitric acid concentrations, and temperatures, 25, 35 and 45oC (except in the case of cis-carbonato (C-meso-5,12-dimethyl-1,4,8,11-tetra-azacyclotetradecane) cobalt (III) which was studied only at 35oC). The rate expression takes the form kobs = ko + k1[H]+, where the kobs is the observed first order rate constant at constant hydrogen ion concentration. The ko terms which represents the “spontaneous” or water reaction is kinetically unimportant at the acidities used in the study. The activation parameters have been determined and the mechanism of the reactions discussed. The complexes display solvent deuterium isotope effects (kD2O/kH2O) in the range of 2.1 to 2.65. The magnitude of the solvent isotope effects is consistent with a rapid pre-equilibrium protonation followed by rate-determining ring-opening, and excludes a mechanism involving concerted attack by H¬3O+. The values of ΔS+ suggest an A- type reaction to give a five-coordinate intermediate. The second part of this section deals with the kinetics of the acid-aquation of the cis-sichloro)C-meso-5,12-dimethyl-1,4,8,11-tetra-azacyclotetradecane)chromium(III) cation. The reactions were studied using 0.01 mol dm-3 nitric acid as the reaction medium. The hydrolysis occurs in two steps, cis-[CrLC1s]+ + H2O → cis-[CrLC1(H2O)]2+ + Cl- cis-[CrLC1(H2O)]2+ + H2O → cis-[CrL(H2O)2]3+ + Cl- and activation parameters for both hydrolyses obtained. Loss of the first chloride ligand is ca. 76 times faster than the second at 25oC. Possible mechanisms for these reactions are considered. The second section of the thesis deals with synthetic and stereochemical studies of macrocyclic ligands and their metal complexes. Reduction of the nickel(II) complex of C-meso-5,7,12,14-tetra-azacyclotetradeca-4,11-diene gives three diastereoisomeric tetramethylcyclams (as their nickel(II) complexes, (1), (2) and (3)). One of these complexes, believed to be (2), is formed preferentially (ca 70%) and is readily obtained isomerically pure. Molecular models indicate that the four [diagram (1) C-meso-C-rac] [diagram (2) C-meso-C-meso] [diagram (3) C-meso-C-meso] methyl groups in (2) are equatorial, and that the axial coordination sites are readily accessible to monodentate ligands. A number of octahedral nickel(II) complexes of (2) have been prepared and characterised. The thermodynamics of the NiL2+ + 2H2O → [NiL(H2O)22+ equilibrium has been studied in detail and values of ΔHo and ΔSo obtained. Fractional crystallisation of the nickel(II) complex of 5,6,12,13-tetramethyl-1,4,8,11-tetra-azacyclotetradeca-4,11-diene from aqueous solution led to the characterization of three isomers (arising from chiral nitrogen and carbon centres) designated a, b and c, identified by their 1H n.m.r. spectra. Equilibration of a and b in DMSO/KOH gives isomer d. N.m.r. studies confirm that the reaction proceeds via the steps, b → a → d. Cobalt(III), copper(II) and nickel(II) complexes of 1,4,7,10,13,16-hexa-azacycloctadecane have been prepared and characterised and the stereochemistry of the cobalt(III) complex discussed. The 1H n.m.r. spectrum of the cobalt(III) complex in d6-DMSO solution is consistent with the unsymm topology. This assignment is fully confirmed by 13C n.m.r. The 13C n.m.r. spectrum unequivocally establishes that the compound consists of the two NH geometrical isomers of the unsymm topology which are present in roughly equal amounts, (4) and (5). [diagram (4)] [diagram (5)] A number of metal(II) and cobalt(III) complexes of the macrocyclic ligand 5,12-dimethyl-7,14-di (2-thienyl)-1,4,8,11-tetra-azacyclotetradeca-4,11-diene (6) have been prepared and characterised. The spectroscopic properties of [diagram (6)] these complexes are consistent with a square planar geometry for the metal(II) perchlorate salts and a trans-arrangement of the unidentate ligands in the octahedral cobalt(II) complexes. The structures of all compounds were confirmed by elemental analysis, spectroscopic investigations, and in some cases by conductivity measurements

Nonadherence among Kuwaiti nationals with type 2 diabetes mellitus

Introduction: Nonadherence to medications and diabetes self-care behaviours among Kuwaitis with Type 2 Diabetes Mellitus (T2DM) is believed to be a major barrier to appropriate management of the disease. Published studies of nonadherence in T2DM suggest a Western bias which may not adequately describe the Kuwaiti experience. Aims: (1) To explore barriers to adherence to medications and other diabetes self-care behaviours among Kuwaitis with T2DM. (2) To assess the prevalence of nonadherence to medications and other diabetes self-care behaviours, and identify predictors of medication nonadherence. Methods: (1) A qualitative exploratory study, using in-depth interviews with 20 Kuwaiti T2DM patients. (2) A cross-sectional quantitative survey of 250 Kuwaiti T2DM patients, randomly selected from all the six districts of the country. Results: Qualitative interviews revealed that many barriers to diabetes medications and other self-care behaviours among Kuwaitis appeared specific to the Kuwaiti culture, such as patients' beliefs about Western brands of medications, fatalism and submission to God's will in coping with illness, perceptions of social support, and difficulties related to access and organisation of the Kuwaiti healthcare system. However, some reported barriers were similar to the Western literature. The quantitative survey showed 43% of Kuwaiti T2DM patients were nonadherent to their diabetes medications, of which 45% had made a decision not to take their medications. Over half of nonadherers (52%) inadvertently did not take the medications as prescribed, mostly as a result of forgetting (42%). Nonadherence to medications was associated with poorer health outcomes. Beliefs about medicines and perceptions of healthcare provider support were issues of concern. Nonadherence to other diabetes self-care behaviours was high, 15%-68%, depending on the behaviour. Conclusion: Diabetic nonadherence constitutes a significant proportion in Kuwait. Barriers to adherence were complex and often interlinked, suggesting that multiple, tailored interventions may be needed to improve diabetes adherence, care and outcomes

The use of nebulisers in the home : a study with patients and carers

Introduction: Inhalational therapy is the mainstay of treatment for COPD, and nebuliser therapy is commonly prescribed for the management of severe COPD in the home. The success of inhalational therapy is multi-factorial and largely depends on the ability of the patient to use correctly the inhaler device. Whilst the problems with the use of pressurized metered dose inhalers and dry powder inhalers are documented in the literature, little is known about how COPD patients and their carers use nebulisers in the home. The aim of the study is to describe the experiences of COPD patients and their carers with the use of nebuliser therapy in the home and to identify their priorities and concerns in the context of current disease management, support and potential health services. Methods: The study was conducted in primary and intermediate settings within a strategic health region in the UK (North West London). A representative sample including patients with different durations of nebuliser use and different disease severity levels were recruited. Data were collected in the patients' homes on one occasion using semi-structured interviews, non-participant observations and survey methods. A mixed approach to data analysis was used to triangulate data from different methods. The Framework method was used to analyse the qualitative data and the Statistical Package for Social Sciences (SPSS) was used to analyse the quantitative data. Results: All patients experienced problems with the use of their nebulisers in the home during assembling, filling, cleaning and maintaining their device. The interviews revealed that factors such as: the complexity of setting up the equipment, lack of instructions on its assembly, poor manual dexterity, costs and poor access to accessories contributed to the problems. Practical problems were frequendy experienced by patients who had frequent hospital admissions, were treated by more than one doctor and used a facemask. Moreover, 30% of COPD patients were dependent on carers for vital assistance with the use of the nebuliser; on average, the carers spent 3.5 hours per week (range 1 - 10.5 hours) undertaking nebuliser-related activities. Carers performed a range of activities (mean 6, range 2 - 9), which included organisational and practical tasks and they frequently experienced difficulties (mean = 3, range 0 - 9) with providing practical assistance such as setting up, dismantling and cleaning the nebuliser parts. Several factors (timing of therapy, complexity of the dosing regimen, co-morbidities and deterioration in health status) affected the level of carers' involvement which ranged from taking full responsibility to providing assistance with particular aspects of nebuliser use when required. The patients and the carers were shown to be active decision-makers with regard to the need and use of their therapy and overall condition management. Conclusion: Improving health outcomes for COPD patients and their carers is a central goal of health policy in the UK. A holistic assessment of the use of nebuliser therapy identified that COPD patients and their carers frequently encountered practical problems with the use of nebulisers in the home which should inform healthcare providers to effectively support patients and their carers to optimise treatment outcomes.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Nonadherence among Kuwaiti nationals with type 2 diabetes mellitus

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Barriers to medication taking among Kuwaiti patients with type 2 diabetes: a qualitative study

Fatima B Jeragh-Alhaddad,1,2 Mohammad Waheedi,2 Nick D Barber,1 Tina Penick Brock3 1Department of Practice and Policy, University College London School of Pharmacy, London, UK; 2Department of Pharmacy Practice, Faculty of Pharmacy, Kuwait University, Kuwait City, Kuwait; 3Department of Clinical Pharmacy, School of Pharmacy, University of California, San Francisco, CA, USA Background: Nonadherence to medications among Kuwaitis with type 2 diabetes mellitus (T2DM) is believed to be a major barrier to appropriate management of the disease. Published studies of barriers to medication adherence in T2DM suggest a Western bias, which may not adequately describe the Kuwaiti experience. Aim: The purpose of this study was to explore barriers to medication adherence among Kuwaiti adults with T2DM. Methods: Semi-structured interviews were conducted with 20 Kuwaiti patients with type 2 diabetes. The interviews were digitally recorded, transcribed, and analyzed using thematic analysis. Results: Barriers to medication adherence were identified. Emerging themes were: 1) lack of education/awareness about diabetes/medications, 2) beliefs about medicines/diabetes, 3) spirituality and God-centered locus of control, 4) attitudes toward diabetes 5) perceptions of self-expertise with the disease and body awareness, 6) social stigma, 7) perceptions of social support, 8) impact of illness on patient’s life, 9) perceptions of health care providers’ attitudes toward patients, and 10) health system-related factors, such as access difficulties and inequalities of medication supply and services. Conclusion: Personal, sociocultural, religious, health care provider, and health care system-related factors may impede medication adherence among Kuwaitis with type 2 diabetes. Interventions to improve care and therapeutic outcomes in this particular population must recognize and attempt to resolve these factors. Keywords: medication adherence, type 2 diabetes mellitus, Kuwait, qualitativ

"Patients' understanding is the problem": physicians' views of nonadherence among Arabs with type 2 diabetes

Mohammad Waheedi,1 Fatima B Jeragh-Alhaddad,1 Abdelmoneim Ismail Awad,1 Hannes Enlund2 1Faculty of Pharmacy, Kuwait University, Kuwait; 2Finnish Medicines Agency, Kuopio, Finland Purpose: Nonadherence to diabetes medication is a significant barrier toward achieving positive treatment outcomes. There is an abundance of research looking at the problem from the patient perspective, but less from the provider perspective. The Middle East region has one of the highest prevalences of type 2 diabetes in the world, with special cultural characteristics, which require research attention. The aim of this study was to explore the views of primary-care physicians on medication nonadherence among type 2 diabetes patients. Materials and methods: A descriptive qualitative study was performed using one-on-one semistructured interviews of 21 primary-care physicians who were selected using stratified and random sampling from polyclinics in the five health districts in Kuwait. The interviews elicited the participants’ views about barriers and facilitators of medication adherence in type 2 diabetes patients. The interviews were audio-recorded and transcribed verbatim. Thematic content analysis with constant comparison was used to generate the codes and themes to arrive at a core category. Results: Patient understanding, including knowledge, beliefs, and attitudes, was identified by respondents as the core determinant of medication nonadherence in type 2 diabetes. This was composed of six major themes: four against understanding and two for understanding. The ones against were “Patients do not understand diabetes”, “Patients do not understand the importance of medications”, “What the patient hears from friends is more important than what the doctor says”, “Patients are in denial (or difficult)”. Themes for understanding were “I need to educate more” and “Patients must hear it from other sources”. Conclusion: That lack of understanding among patients results in medication nonadherence is the dominant view of primary-care physicians. This finding has implications in relation to the evolution of diabetes care toward more patient-centeredness within the cultural context. Keywords: medication adherence, primary-care providers, qualitative, patient-centeredness, Kuwai