Transitional models for multivariate longitudinal binary responses with an application to behavioral data of Canadian children

In longitudinal studies, observational units (commonly referred to as individuals) drawn from some population of interest are followed prospectively over time, and measurements from each individual are taken repeatedly at different points in time with the ultimate goal of characterizing the important features of the population. Longitudinal data naturally arise in many areas of study, where the characterization of the population may be achieved by investigating the effects of covariates on a response. Two or more correlated responses from each individual are also common in longitudinal studies, giving rise to multivariate longitudinal data. For example, the National Longitudinal Survey of Children and Youth (NLSCY) is a long-term study to observe the development of Canadian children. In this survey, measurements about factors influencing a child's social, emotional and behavioral development are collected over time; anxiety and aggression reported for each child in this study may be considered as two response variables to characterize the emotional and behavioral development of children. Since in longitudinal studies, information is collected repeatedly from each individual over time, the occurrence of an event at a particular time point may increase/decrease the likelihood of the occurrence of another event in future. Failure to take into account this phenomenon in analyzing longitudinal data may lead to erroneous conclusion. Moreover, repeated responses (e.g., anxiety and aggression) from an individual may exhibit correlation over time. Separate analyses of such multivariate longitudinal responses ignore this correlation, and as a result, cannot reveal the potential association among the responses which could be of paramount importance in many applications. Therefore, analysis of multivariate longitudinal data requires substantial extension of the standard longitudinal methods. In this thesis, we describe a methodology based on the transition models for multivariate longitudinal binary data to address the transitional behavior between two states characterized by binary responses for two different responses (i.e., two processes). Transitional analysis of multivariate longitudinal binary data can address the longitudinal association within processes and enable marginal interpretation of covariate effects. In addition, estimation and inference of the association between the processes can also be achieved via such models. We illustrate this approach with an application to the NLSCY data, where anxiety and aggression (two correlated responses) are modeled as a function of covariates (gender, depression of person most knowledgeable, number of siblings and family status) to identify their effects on behavioral development of Canadian children. In addition, the extent and direction of the association between two responses are estimated. Gender of the child is found statistically significant for both directions of transition, i.e., from low to high and high to low, of aggression. On contrary, gender of the child is found statistically not significant for both transitions of anxiety. Meanwhile, depression of person most knowledgeable is found marginally significant in the high to low direction for aggression. For association parameters, all four directions of associations between anxiety and aggression are found statistically significant

Fabrication, functionalization and characterization of silica monolith for forensic chemistry applications

The physiochemical properties of silica monolith make it an ideal base material for drugs extracting, pre-concentrating and separation from biological samples which can interact not only with molecules but also with ions and atoms. However, the fabrication of silica monoliths still has some problems, such as cost, limited capacity and fabrication and modification methodology, which can be time consuming and labour intensive. Structure evolution of silica monolith was studied in microwave and conventionally processed samples over the temperature range from 25 to 70 oC. The samples were produced using sol-gel processing. The microwave process was performed using a single mode cavity at 2.45GHz. Characterization of produced silica monoliths were carried out using a variety of techniques, including Scanning Electron Microscopy (SEM) analysis, EDX analysis, BET and BJH analysis. The data obtained showed that structural differences do exist between conventional and microwave processed samples. It was found however, that microwave based fabrication offered a significantly quicker (11 min) gelation process, compared to those obtained using the thermal heated oven methodology (4,320 min).The silica monolithic surfaces were modified with three different phases C₁₈, gold nanoparticles and graphene which received a thermal treatment at different programmed powers in two different ovens, conventional and microwave. Three substantial variance were also identified from the structural characterization of modified silica surfaces processed using microwave heating and conventional heating methods:1- The use of microwave heating during C₁₈ surface modification improved not only the attachment of C₁₈ groups to the silica surface but also increased the extraction efficiency of caffeine and eserine from standard solutions (102 % and 97 %, respectively).2- The fabrication of gold nanoparticles-NH2-silica monolith using microwave heating was found to improve the sensitivity and selectivity of modified silica surface and make possible to extract, detect and quantify more than one type of drugs of abuse at the same time within few minutes.3- Using graphene-silica monolith makes the extraction of non-polar, polar, very polar and water-soluble analytes, based on both hydrophobic and electronic interactions, easy and simple.Fabrication and modification of silica monoliths using microwave heating make the sol-gel procedure much faster and easier and allow for non-polar, polar, very polar and water-soluble analytes to be extracted more efficiently to produce accurate and precise results compared to the conventional method for fabrication and modification of silica monoliths using three phases (C₁₈, gold nanoparticles and graphene).Finally, this technique make the modified silica monolithic column capable to extract selected drugs of abuse from biological samples and produce qualitative and quantitative results at the same time using chemiluminescence based immunoassays or HPLC-UV

THE RELATIONSHIP BETWEEN CORRUPTION AND ECONOMIC GROWTH IN PAKISTAN — LOOKING BEYOUND THE INCUMBENT

Corruption has opaque significant consideration for researchers during the last few decades due to its effect on economic growth. This study examines the relationship between corruption and economic growth in Pakistan, covering the period from 1985 to 2010. Stationarity of the variables was checked through unit root test and then apply multiple regression technique. The results shows that government expenditures, education expenditures and population growth has a positive impact on per capita GDP, however, domestic investment and corruption has a negative impact on per capita income in Pakistan. It implies that corruption is a major factor impeding economic development. Corruption hampers economic growth, disproportionately burdens the poor and undermines the effectiveness of investment and aid

Foreign Direct Investment and Economic Growth Literature Review from 1994 to 2012

AbstractForeign direct investment (FDI) has been viewed as a power affecting economic growth (EG) directly and indirectly during the past few decades. This paper reviewed an amount of researches examining the relationships between FDI and EG, especially the effects of FDI on EG, from 1994 up to 2012. The results show that the main finding of the FDI-EG relation is significantly positive, but in some cases it is negative or even null. And within the relation, there exist several influencing factors such as the adequate levels of human capital, the well-developed financial markets, the complementarity between domestic and foreign investment and the open trade regimes, etc

The Influence of the Upper Extremities Movement on Take-off in Vertical Jump

The positive influence of the upper extremities swing on the effect of take-off in jumping is well known. Such movement is used in vertical jump, long jump, high jump and others. This effect causes increase of the ground reaction force produced by each segment (Luhtanen and Komi, 1978) and in addition the upper extremities swing has also a coordinative meaning, for example while double overarm movement at running is to be change into parallel movement at take off (high jump), There are also such situations like in basketball and volleyball (Wielki and Dangre, 1983; Wilkerson, 1983) in which the desired arms swing is limited by the other task which has to be performed like blocking or passing the ball. Loss in the height of the vertical jump -while the arms swing is not executed -and diminishing ground reaction force at take-off and the possible changes in biomechanical variables during take-off, are the object of this experiment

Discussion of the technology and research in fuel injectors common rail system

Common rail is one of the most important components in a diesel and gasoline direct injection system. It features a high-pressure (100 bar) fuel rail feeding solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors. Third-generation common rail diesels now feature piezoelectric injectors for increased precision, with fuel pressures up to 2,500 bar. The purpose of this review paper is to investigate the technology and research in fuel injectors common rail system. This review paper focuses on component of common rail injection system, pioneer of common rail injection, characteristics of common rail injection system, method to reduce smoke and NOx emission simultaneously and impact of common rail injection system. Based on our research, it can be concluded that common rail injection gives many benefit such as good for the engine performance, safe to use, and for to reduce the emission of the vehicle. Fuel injection common rail system is the modern technology that must be developed. Nowadays, our earth is polluting by vehicle output such as smoke. If the common rail system is developed, it can reduce the pollution and keep our atmosphere clean and safe

Extrapancreatic actions of incretin-based therapies on bone in diabetes mellitus

Diabetes mellitus is correlated with modifications in bone microarchitectural and mechanical strength, leading to increased bone fragility. The incretin hormones, with a classical effect to increase insulin secretion following food ingestion, are now postulated to have important direct effects on bone. As such, glucose-dependent insulinotropic polypeptide (GIP) has dual actions on bone cells; enhancing bone�forming activity of osteoblasts and suppressing bone resorption by osteoclasts. The sister incretin of GIP, glucagon-like peptide-1 (GLP-1), is also suspected to directly influence bone health in a beneficial manner, although mechanism are less clear at present. The physiological actions of incretins are attenuated by dipeptidyl peptidase (DPP-4) activity and it is speculated that introduction of DPP-4 inhibitor may also positively affect quality of the skeleton. As such, this thesis evaluates the potential beneficial effects of a DPP-4 resistant GIP analogue, namely [D-Ala2 ]GIP, on osteoblastic-derived, SaOS-2 cells, and also preliminary in vivo studies on the impact of genetic deficiencies of GIPRs and GLP-1Rs on bone mineral density and content. Further studies characterised the beneficial effects of incretin-based therapies on metabolic control, bone microstructure and bone mechanical integrity in animal models of pharmacologically-, genetically- and environmentally-induced diabetes. GIP and related stable analogue increased bone-forming biomarkers in SaOS-2 cells and importantly, [D-Ala2 ]GIP was shown to be more potent than native GIP. Knockout mouse studies revealed that both GIPR and GLP-1R signaling are important for optimum bone mass. All diabetic mouse models displayed reduced bone mass, altered bone micromorphology and impairment of bone mechanical strength, similar to the human situation, confirming their appropriateness. The incretin-based therapeutics, [D-Ala2 ]GIP and Liraglutide, in streptozotocin-diabetic significantly increased bone matrix properties, indicating recovery of bone strength at the tissue level. The beneficial effects of administration of [D-Ala2 ]GIP�oxyntomodulin on bone health in db/db mice were more prominent as the Oxm analogue did not only improve bone strength at tissue level, but also at whole-bone level. These modifications were independent of metabolic status. Twice-daily Exendin-4 therapy improved glycaemic control and increased work required to resist bone fracture in high-fat fed mice. It was also established that Sitagliptin had neutral effects on bone microstructure and mechanical strength in high-fat mice. In summary, these data demonstrate the negative impact of diabetes mellitus on normal skeleton development and bone quality. Moreover, this thesis highlights the growing potential of incretin-based therapies for ameliorating bone defects and improving the increased fragility fracture risk associated with diabete