Resurvey of the financing of education in a city public school system.

Thesis (Ed.M.)--Boston University This item was digitized by the Internet Archive

The design, development and characterization of a self-replicating DNA expression technology

High quality T-cell immunogenicity can be an elusive type of immunity to generate and one that is often sought after by virologists, immunologists and cancer researchers alike. When T-cell immunity is generated using current methodologies the quality and magnitude of the immunological response achieved is often weak and unable to create protective immunity. Among current methods, DNA vaccines, generate highly specific T-cell immunity towards targeted antigens, and do not suffer from issues like misdirected vector targeted immunity, like viral based vectors. DNA vaccines, however, face a variety of their own weaknesses. These include, inefficient delivery, high biological loss inside the body, and the inability to counteract or avoid immediate innate cellular defence mechanisms, which limit their ability to persist inside a host cell. For these reasons, DNA vaccines are usually combined with more conventional viral vaccines in what is known as a DNA prime and viral boost regiment strategy. Combining them works well and results in improved immunity towards targeted antigens that is superior to what is obtained when either DNA or recombinant vaccines are used alone. To address many of the core issues faced by DNA vaccines, I report here on the design, development and characterization of a self-replication DNA gene expression technology. This novel DNA expression system employs a form of DNA replication (known as rolling circle replication) to generate a self-replicating DNA amplicon that can amplify its own copy number and the relative localised levels of antigen expression inside transfected mammalian cells in tissue culture and within Balb/cJ mice. These capabilities help effectively mitigate many of the core issues faced by DNA vaccines. The technology developed was shown to significantly increase gene expression for eGFP and Luciferase reporter genes, with an overall average increase in expression of approximately two-fold by 48 h post transfection in HeLa S3 cells. More specifically, an increase of at least two-fold in the absolute maximum level of the gene of interest per cell was also observed. Such localised doubling in antigen expression, at the cellular level, is believed to enhance innate immune activation and improve the overall immune response. Experimental results indicated that gene expression levels by this technology is non static in nature and appears to increase in magnitude within affected cells over time as was hypothesised. This provided strong evidence that the replication technology appears to be functioning as was expected and was able to demonstrate the ability to elevate antigen expression over time, potentially starting from extremely low and otherwise ineffective starting concentrations. This ability has potential to effectively mitigate many of the issues associated DNA vaccines such as low and ineffective delivery. This capability was observed in tissue culture as a steady increase in reporter gene expression levels across the entire range of DNA transfection levels. Furthermore, the increases in gene expression were observed to continue to amplify over time, eliminating the presence of weakly fluorescing cells in tissue culture. By 11 days post transfection, every observable cell transfected with the replication expression system, was observed to have extremely high levels of fluorescence. With recorded fluorescence levels being as bright or brighter than the highest levels obtained under normal transfections with no replicative plasmids (~48-72 h). Unique cellular responses to the presence of the replicating gene expression technology were also observed. These included an apparent slowdown in cellular metabolic activity and growth among cells transfected with replicating vectors. This was observed as a decrease in cellular division and total cell number by ~50%, by 48 h post transfection. This was accompanied by significant increases in cell size, internal cellular granularity, and gene-of-interest expression per cell. These changes were observed among all cells regardless of their relative DNA transfection level. This was demonstrated by assessment of the change in the range, mean, median, skewness and standard deviation of the cellular distribution curves for eGFP expression, cell size and internal cellular granularity. These observations provided further evidence of the dynamically changing and active nature of this technology. This also provided evidence that the replicating gene expression technology has a definitively different kind of cellular impact and effect on transfected cells compared to non-replicating DNA expression systems. Pilot studies to test the technology in Balb/cJ mice indicated, the technology appears to be functional within this animal model and was able to increase gene of interest (eGFP) expression levels compared to an equivalent non-replicating DNA expression vector control. Furthermore, these animal experiments also demonstrated significant increases in the maximum possible level of expression achieved within localised ‘hot spots' of muscle fibre bundles. This effect appeared to increase following transient addition of additional replication associated protein (Rep), giving further evidence this technology appears to be functional within the Balb/cJ animal model. Suggesting that the rate at which the replication amplification process occurs, may also be manipulated by adjusting Rep concentration. Finally, an antiviral response gene array was run to look for evidence that the replicating gene expression technology could increases antiviral response gene activation, to possibly improve T-cell activation and immunity. The array provided evidence improved antiviral response gene activation was occurring however the data was inconclusive in nature and further investigation is needed to verify these preliminary findings. The array also showed significant evidence of Rep induced Caspase 10 (CASP10), gene suppression. This suggests that Rep may play a role in the survival and virulence ofBFDV by acting as a suppressor of cellular apoptosis in a concentration-dependant manner and is worth investigating further

Numerical modeling of buoyant plumes in a turbulent, stratified atmosphere

A widely applicable computational model of buoyant, bent-over plumes in realistic atmospheres is constructed. To do this, the two-dimensional, time-dependent fluid mechanics equations are numerically integrated, while a number of important physical approximations serve to keep the approach at a tractable level. A three-dimensional picture of a steady state plume is constructed from a se- quence of time-dependent, two-dimensional plume cross sec- tions--each cross section of the sequence is spaced pro- gressively further downwind as it is advected for a pro- gressively longer time by the prevailing wind. The dyna- mics of the plume simulations are quite general. The buoyancy sources in the plume include the sensible heat in the plume, the latent heat absorbed or released in plume moisture processes, and the heating of the plume by a radioactive pollutant in the plume. The atmospheric state in the simulations is also quite general. Atmospheric variables are allowed to be functions of height, and the ambient atmospheric turbulence (also a function of height) is included in the simulations. A demonstration of the ability of the model to repro- duce the solutions to problems that are known is under- taken. Comparisons to buoyant line-thermal laboratory experiments show that the model calculates the dynamics of the fluid motions to an acceptable accuracy. Comparisons to atmospheric plume rise and dispersion experiments show that the model can simulate individual plumes more accur- ately than existing correlations because it calculates the effect of the atmospheric turbulence and stratification from first-principles. The comparisons also show that improvements to the model are likely to be made by more accurately describing the anisotropic nature of atmospheric turbulence, and the production of turbulence by the sources of buoyancy.Sponsored by the Consolidated Edison Company of New York and Northeast Utilities Service Corporation

Environmental Factors Associated with Frequency of Collection and Semen Characteristics of Yorkshire Boars

Animal Scienc

Protein Requirements for the Young Growing Boar

Animal Scienc

The remote exercise monitoring trial for exercise-based cardiac rehabilitation (REMOTE-CR): a randomised controlled trial protocol

BACKGROUND: Exercise is an essential component of contemporary cardiac rehabilitation programs for the secondary prevention of coronary heart disease. Despite the benefits associated with regular exercise, adherence with supervised exercise-based cardiac rehabilitation remains low. Increasingly powerful mobile technologies, such as smartphones and wireless physiological sensors, may extend the capability of exercise-based cardiac rehabilitation by enabling real-time exercise monitoring for those with coronary heart disease. This study compares the effectiveness of technology-assisted, home-based, remote monitored exercise-based cardiac rehabilitation (REMOTE) to standard supervised exercise-based cardiac rehabilitation in New Zealand adults with a diagnosis of coronary heart disease. METHODS/DESIGN: A two-arm, parallel, non-inferiority, randomised controlled trial will be conducted at two sites in New Zealand. One hundred and sixty two participants will be randomised at a 1:1 ratio to receive a 12-week program of technology-assisted, home-based, remote monitored exercise-based cardiac rehabilitation (intervention), or an 8-12 program of standard supervised exercise-based cardiac rehabilitation (control).The primary outcome is post-treatment maximal oxygen uptake (V̇O2max). Secondary outcomes include cardiovascular risk factors (blood lipid and glucose concentrations, blood pressure, anthropometry), self-efficacy, intentions and motivation to be active, objectively measured physical activity, self-reported leisure time exercise and health-related quality of life. Cost information will also be collected to compare the two modes of delivery. All outcomes are assessed at baseline, post-treatment, and 6 months, except for V̇O2max, blood lipid and glucose concentrations, which are assessed at baseline and post-treatment only. DISCUSSION: This novel study will compare the effectiveness of technology-supported exercise-based cardiac rehabilitation to a traditional supervised approach. If the REMOTE program proves to be as effective as traditional cardiac rehabilitation, it has potential to augment current practice by increasing access for those who cannot utilise existing services. <br /

Neither colony nor enclave: calling for dialogical contextualism in management and organization studies

We express our unease with one-sided invitations into the Northern mainstream, as well as with Southern critics’ retreat into indigenous enclaves of organizational scholarship. We use this dichotomy to theorize the role of context in organizational theorizing by linking scholarly conversations on context, analogical reasoning, and problematizing assumptions. This creates the opportunity to more carefully consider how not just our theoretical backgrounds but also our contextual life-worlds provide the assumptions and analogies we bring into our theorizing. We use this platform to consider in more detail systematic biases in both the Northern mainstream (erasing and imposing biases) and the Southern critique (scapegoating and valorizing biases). These biases have in common that they essentialize context. To address this risk and to facilitate contextual reflexivity, we propose a form of dialogical scholarly engagement to generate complementary spaces to fruitfully question our contextually embedded assumptions

The interaction of silver nanoparticles with triosephosphate isomerase from human and malarial parasite (Plasmodium falciparum) : a comparative study

The advent of advanced modern nanotechnology techniques offers new and exciting opportunities to develop novel nanotech-derived antimalarial nanodrugs with enhanced selective and targeting abilities that allow for lower effective drug dosages, longer drug persistence and reduced drug degradation within the body. Using a nanodrug approach also has the advantage of avoiding drug resistance problems that plague reconfigured versions of already-existing antimalarial drugs. In this study recombinant triosephosphate isomerase enzymes from Plasmodium falciparum (PfTIM) and Humans (hTIM) were recombinantly expressed, purified and characterised. PfTIM was shown to have optimal pH stability at pH 5.0-5.5 and thermal stability at 25°C with Km 4.34 mM and Vmax 0.876 μmol.ml⁻ₑmin⁻ₑ. For hTIM, these parameters were as follows: pH optima of 6.5-7.0; temperature optima of 30°C, with Km 2.27 mM and Vmax 0.714 μmol.ml⁻ₑmin⁻ₑ. Recombinant TIM enzymes were subjected to inhibition studies using polyvinylpyrrolidone (PVP) stabilised silver nanoparticles (AgNPs) of 4-12 nm in diameter. These studies showed that the AgNPs were able to selectively inhibit PfTIM over hTIM with an 8-fold greater decrease in enzymatic efficiency (Kcat/Km) observed for PfTIM, as compared to hTIM, for kinetics tests done using 0.06 μM of AgNPs. Complete inhibition of PfTIM under optimal conditions was achieved using 0.25 μM AgNPs after 45 minutes while hTIM maintained approximately 31% of its activity at this AgNP concentration. The above results indicate that selective enzymatic targeting of the important, key metabolic enzyme TIM, can be achieved using nanotechnology-derived nanodrugs. It was demonstrated that the key structural differences, between the two enzyme variants, were significant enough to create unique characteristics for each TIM variant, thereby allowing for selective enzyme targeting using AgNPs. If these AgNPs could be coupled with a nanotechnology-derived, targeted localization mechanism – possibly using apoferritin to deliver the AgNPs to infected erythrocytes (Burns and Pollock, 2008) – then such an approach could offer new opportunities for the development of viable antimalarial nanodrugs. For this to be achieved further research into several key areas will be required, including nanoparticle toxicity, drug localization and testing the lethality of the system on live parasite cultures